Effects of after school exercise service on physical fitness in primary school students / 中国学校卫生

Objective@#To investigate the effects of after school exercise service (referred to as the "after school ES") on physical health, so as to provide evidence for possible beneficial effect of after school ES.@*Methods@#Students in the fourth grade of primary school were recruited from September 2021 to July 2022 in Changsha City and divided into the control group ( n =220) and the after school ES group ( n =220). The control group only participated in the regular physical education activities of the school. The after school ES group received after school ES for one academic year, 4 times a week, 40-50 minutes per time, for a total of 32 weeks. Body shape indicators such as height, weight and percentage of body fat, as well as physical fitness indicators such as 50 meter running, grip strength and progressive aerobic cardiovascular endurance run (PACER) were measured in September to October 2021 and June to July 2022, respectively. Independent sample t-test, Chi square test and two factors repeated measurement analysis of variance were used for statistical analysis of the data.@*Results@#After one academic year, compared with the control group [(13.52±2.30)kg], muscle mass of primary school students in the after school ES group [(13.76±2.32)kg] significantly increased, while waist to hip ratio [(0.95±0.16)] and percentage of body fat [(20.17±7.43)%] significantly decreased compared to the control group [(1.01±0.21), (22.02±12.34)%]( F=330.70, 6.85, 4.33, P <0.05). The proportion of overweight and obesity in after school ES group decreased significantly from 19.5% to 12.3% ( χ 2=4.35, P <0.05). Compared with the control group, the scores of 50 meter running [(10.00±1.06, 10.21±0.83)s], 1 minute sit up [(33.25±8.24, 30.76±9.34)times], sitting and flexion [(14.53±7.50, 8.59±6.32)cm], 1 minute rope skipping [(125.01±30.50, 115.97±32.09)times], eyes closed and single legged standing [(30.00±34.72, 25.72±23.82)s], selective response time [(635.66±91.72, 652.79±120.42)ms] and VO 2max [(45.31± 1.02 , 43.67±0.85)mL/(kg〖 ·min)] in the after school ES group were significantly improved, with statistical significance ( F= 5.32 , 443.14, 97.23, 814.07, 36.49, 6.11, 396.91, P <0.05).@*Conclusions@#After school ES can improve body shape of primary school students, reduce the risk of overweight and obesity and enhance physical fitness. It is recommended that schools should appropriately increase after school ES to promote physical fitness of students.

Evaluation of the Association between Pelvic Diameters and Pelvic Types on Computed Tomography Images in Healthy Turkish Females / Evaluación de la Asociación entre Diámetros Pélvicos y Tipos de Pelvis en Imágenes de Tomografías Computarizadas en Mujeres Turcas Sanas

SUMMARY: Pelvis contributes to both human locomotion and obstetrics, and normal vaginal delivery is associated with a spacious inlet, a large interspinosus diameter. This paper aimed to measure crucial diameters of pelvic ring, and to determine both the prevalence of pelvic types, and labor types including normal vaginal delivery or caesarean section in Turkish healthy females. Additionally, it was aimed to evaluate presence of relationship between pelvic types and pelvic diameters. Labor shape of subjects was obtained from hospital records. This retrospective study was carried out on 165 healthy subjects aged between 18 and 45 years. Anteroposterior diameter of the pelvic inlet (APDI), anteroposterior diameter of the pelvic outlet, sacrum length (SL), sacrum depth, conjugata vera, obstetrical conjugate, the diagonal conjugate, diameter transversa, diameter bispinous, intertuberous diameter were measured. From these measurements, brim index was calculated and decided to gynecoid, anthropoid and platypelloid type. Also, the andoid type was calculated to the ratio of posterior sagittal diameter of the inlet to conjugata obstetrica. 50.91 % of participants has gynecoid type pelvis, followed by 24.85 % anthropoid type, 14.55 % platypelloid, and 9.70 % android type pelvis. There was a significant difference in APDI, SL, SD, Conjugata vera, Conjugata obstetrica, Conjugata diagonalis, Conjugata transversa, diameter bispinous, diameter intertubercularis and Brim index measurements according to pelvic types. the first degree of narrowing (conjugata vera from 11 to 9) was found in 18 pelvises and 12 pelvises with the pathological degree of narrowing bellonged to the platypelloid type followed by android type pelvis with 6 pelvices. The android type pelvis is not appropriate for natural labor and a good assessment of birth canal can reduce the labor risks. Also, only 7 females who delivered with cesarean have gynecoid type pelvic type. The APDI and SL were significantly lower in subjects having pathological narrowing according to conjugata obstetrica values.

La pelvis contribuye tanto a la locomoción humana como a la obstetricia. El parto vaginal normal se asocia con una entrada espaciosa y un diámetro interespinoso grande. Este artículo tuvo como objetivo medir diámetros cruciales del anillo pélvico y determinar tanto la prevalencia de los tipos pélvicos como los tipos de parto, incluido el parto vaginal normal o la cesárea en mujeres turcas sanas. Además, se buscó evaluar la presencia de relación entre los tipos de pelvis y los diámetros de la pelvis. La forma laboral de los sujetos se obtuvo de los registros hospitalarios. Este estudio retrospectivo se llevó a cabo en 165 mujeres sanas con edades comprendidas entre 18 y 45 años. Se midieron el diámetro anteroposterior de la entrada pélvica (APDPI), el diámetro anteroposterior de la salida pélvica, la longitud del sacro (SL), la profundidad del sacro, la conjugada vera, el conjugado obstétrico, el conjugado diagonal, el diámetro transverso, el diámetro biespinoso y el diámetro intertuberoso. A partir de estas mediciones se calculó el índice del ala y se decidió tipo ginecoide, antropoide y platipoide. Además, el tipo androide se calculó en función de la relación entre el diámetro sagital posterior de la entrada y la conjugada obstétrica. El 50,91 % de los participantes tenía pelvis de tipo ginecoide, seguida del 24,85 % de pelvis de tipo antropoide, el 14,55 % de tipo platipeloide y el 9,70 % de tipo androide. Hubo una diferencia significativa en las mediciones de APDPI, SL, SD, Conjugada vera, Conjugada obstétrica, Conjugada diagonal, Conjugata transversa, diámetro biespinoso, diámetro intertubercular e índice de ala según los tipos de pelvis. El primer grado de estrechamiento (conjugada vera del 11 al 9) se encontró en 18 pelvis y 12 pelvis, siendo el grado patológico de estrechamiento del tipo platipeloide seguido de pelvis tipo androide con 6 pelvis. La pelvis tipo androide no es apropiada para el parto natural y una buena evaluación del canal del parto puede reducir los riesgos. Además, solo 7 mujeres que dieron a luz por cesárea tenían un tipo pélvico de tipo ginecoides. El APDPI y SL fueron significativamente más bajos en mujeres que tenían estrechamiento patológico según los valores obstétricos conjugados.

3D Foot Anthropometric Measurements Under Two Weight- Bearing Conditions for Ergonomic Design of Foot-Related Products / Mediciones Antropométricas del Pie en 3D Bajo Dos Condiciones de Soporte de Peso para el Diseño Ergonómico de Productos Relacionados con los Pies

SUMMARY: This study collected 3D models of the left and right feet from 317 Chinese youth (155 females and 162 males) under half weight-bearing and no weight-bearing conditions. Thirteen dimensions and one angle were taken for each sample. By measuring 13 foot dimensions and 1 angle, this study comprehensively investigated the differences in foot shape between genders and the bilateral differences, as well as the foot shape differences under different conditions. The results showed that regardless of the condition, male foot dimensions were significantly larger than those of females. However, female foot shape was not simply a scaled-down version of male foot shape. On the contrary, the average angle of female feet was greater than that of males under both conditions, indicating a higher prevalence of hallux valgus in females. Both males and females exhibited significant correlation in foot dimensions between the left and right feet, with minimal differences. Under the half weight-bearing condition, the average foot length, width, and circumference were significantly larger than the corresponding measurements under the no weight-bearing condition, while the average height and angle were significantly smaller. Therefore, when designing footwear and foot-related medical rehabilitation aids, it is important to consider foot shape and dimensions under different conditions as a reference. The results of this study provide manufacturers of foot- related products with more detailed data support and are of significant value to the field of medical foot morphology research.

Este estudio recolectó modelos 3D de los pies izquierdo y derecho de 317 jóvenes chinos (155 mujeres y 162 hombres) en condiciones de carga media de peso y sin carga de peso. Para cada muestra se tomaron trece dimensiones y un ángulo. Al medir 13 dimensiones del pie y 1 ángulo, se investigó exhaustivamente las diferencias en la forma del pie entre ambos sexos y sus diferencias bilaterales, así como las diferencias en la forma del pie en diferentes condiciones. Los resultados mostraron que, independientemente de la condición, las dimensiones del pie de los hombres, estos eran significativamente más grandes que los de las mujeres. Sin embargo, la forma del pie femenino no era simplemente una versión reducida de la forma del pie masculino. Por el contrario, el ángulo promedio de los pies de las mujeres fue mayor que el de los hombres en ambas condiciones, lo que indica una mayor prevalencia de hallux valgus en las mujeres. Tanto hombres como mujeres exhibieron una correlación significativa en las dimensiones del pie, entre el pie izquierdo y el derecho, con diferencias mínimas. Bajo la condición de medio soporte de peso, la longitud, el ancho y la circunferencia promedio del pie fueron significativamente mayores que las medidas correspondientes bajo la condición sin soporte de peso, mientras que la altura y el ángulo promedio fueron significativamente más pequeños. Por lo tanto, al diseñar calzado y dispositivos médicos de rehabilitación relacionados con los pies, es importante tener en consideración la forma y las dimensiones del pie en diferentes condiciones como referencia. Los resultados de este estudio, brindan a los fabricantes de productos relacionados con los pies un soporte de datos más detallado y son de gran valor para el campo de la investigación médica de la morfología del pie.

Eating behaviours and perception about body shape among adolescent girls of Panjab University, Chandigarh

Introduction: Indians are experiencing nutritional and lifestyle transitions due to globalization and westernization. The study aimed to find out the current eating patterns and body shape concerns and various factors that influence eating behaviors and body shape concerns of late-adolescent girls. Material and Methods: A cross-sectional study was conducted among 230 undergraduate adolescent girl university students from 12 departments in the age group of 17–19 years. Eating attitude and body shape concerns of adolescents were determined by using the standard eating attitude test-26 (EAT-26) and body shape questionnaire (BSQ-34). Results: The duration of the study was 6 months and participants were selected by simple random sampling. The mean age of the study subjects was 18.52 (±0.63) years. The majority of subjects had an urban background (85%). Less than half had an exercise routine (44%) which was followed daily. As per body mass index (BMI) distribution, 19.57% were underweight, 11.3% were overweight and only 2.17% were obese. An unfavorable eating attitude was found in 18% of subjects whereas 38.2% had mild to the marked concern of body shape. There was a significant positive correlation between BSQ with BMI (r = 0.387, P ? 0.01) and BSQ-34 with EAT-26 (r = 0.367, P ? 0.01). Conclusion: Current study shows that late adolescent urban females are susceptible to eating disorders and are body image conscious. Institutional mechanisms should be brought in place to address the need of improving their eating habits and modification of lifestyle.

Qualitative Histologic Assessment vs. Geomorphometric Analysis of Nerve Fiber Shape after the Intraneural Application of Liposomal Bupivacaine / Evaluación Histológica Cualitativa Versus Análisis Geomorfométrico de la Forma de la Fibra Nerviosa Después de la Aplicación Intraneural de Bupivacaína Liposomal

SUMMARY: The preserved form of all components of the nerve fiber is a prerequisite for the proper conduction of the nerve impulse. various factors can change the shape of nerve fibers. In everyday practice, qualitative histological analysis is the gold standard for detecting changes in shape. Geometric morphometry is an innovative method that objectively enables the assessment of changes in nerve fibers' shape after local anesthetics action. A total of sixty sciatic nerves were used as material, which was intraneural injected with saline solution in the control group (n=30), and a solution of 1.33 % liposomal bupivacaine (n=30) in the test group. After the animals were sacrificed, nerve samples were taken and histological preparations were made. The preparations were first described and examined using a qualitative histological method, after which digital images were made. The images were entered into the MorphoJ program and processed using the method of geometric morphometry. Qualitative histological examination revealed no differences in nerve fibers after intraneurally applied physiological solution and liposomal bupivacaine. Using the method of geometric morphometry, a statistically significant change in the shape of axons was found after intraneurally applied saline solution and liposomal bupivacaine (p=0.0059). No significant differences in histological changes were found after the qualitative histological analysis of nerve fiber cross-section preparations. A statistically significant change in the shape of nerve fiber axons was observed after geometric morphometric analysis of digital images after intraneural application of saline and liposomal bupivacaine.

La forma conservada de todos los componentes de la fibra nerviosa es un requisito previo para la conducción correcta del impulso nervioso. Varios factores pueden cambiar la forma de las fibras nerviosas. En la práctica diaria, el análisis histológico cualitativo es el estándar de oro para detectar cambios de forma. La morfometría geométrica es un método innovador que permite evaluar objetivamente los cambios en la forma de las fibras nerviosas después de la acción de los anestésicos locales. Se utilizó como material un total de sesenta nervios ciáticos, que se inyectaron intraneuralmente con solución salina en el grupo control (n=30), y una solución de bupivacaína liposomal al 1,33 % (n=30) en el grupo de prueba. Después de sacrificados los animales, se tomaron muestras de nervios y se realizaron preparaciones histológicas. Primero se describieron y examinaron las preparaciones utilizando un método histológico cualitativo, después de lo cual se tomaron imágenes digitales. Las imágenes fueron ingresadas al programa MorphoJ y procesadas mediante el método de morfometría geométrica. El examen histológico cualitativo no reveló diferencias en las fibras nerviosas después de la aplicación intraneural de solución fisiológica y bupivacaína liposomal. Usando el método de morfometría geométrica, se encontró un cambio estadísticamente significativo en la forma de los axones después de la aplicación intraneural de solución salina y bupivacaína liposomal (p = 0,0059). No se encontraron diferencias significativas en los cambios histológicos después del análisis histológico cualitativo de las preparaciones de secciones transversales de fibras nerviosas. Se observó un cambio estadísticamente significativo en la forma de los axones de las fibras nerviosas después del análisis de morfometría geométrica de imágenes digitales después de la aplicación intraneural de solución salina y bupivacaína liposomal.

A Morphometric Study of Head in the Population of Young Chinese Adults / Estudio Morfométrico de la Cabeza en la Población de Adultos Jóvenes Chinos

SUMMARY: Due to the complexity of head shape, limited 1D or 2D head anthropometry fail to fully capture its shape characteristics. Currently, there is limited research on clustering analysis of head shape from a shape difference perspective, especially for the head shape of Chinese people. Head shape is influenced by factors such as race, sex, and age, making it imperative to create a head shape database for Chinese individuals. In this study, three-dimensional head data of 339 Chinese young adult were collected, and the head shapes were clustered into 7 clusters using an improved k-medoids algorithm. The differences between clusters and the average head shape were further analyzed. It can be foreseen that the head shape database for Chinese young adult constructed in this study has important reference value for the ergonomic design of head-related products and head morphology research, among other fields.

Debido a la complejidad de la forma de la cabeza, la antropometría limitada de ésta, en 1D o 2D, no logra capturar completamente sus características de forma. Actualmente, existen estudios limitados sobre el análisis de agrupamiento de la forma de la cabeza, desde una perspectiva de diferencia de forma, especialmente en el caso de la población china. La forma de la cabeza está influenciada por factores como la raza, el sexo y la edad, por lo que resulta imperativo crear una base de datos sobre la forma de la cabeza de los individuos chinos. En este estudio, se recopilaron datos tridimensionales de la cabeza de 339 adultos jóvenes chinos, y las formas de la cabeza se agruparon en 7 grupos utilizando un algoritmo k-medoids mejorado. Las diferencias entre los grupos y la forma promedio de la cabeza se analizaron a profundidad. Se puede prever que la base de datos sobre la forma de la cabeza de adultos jóvenes chinos construida en este estudio, tiene un valor de referencia importante para el diseño ergonómico de productos relacionados con la morfología de la cabeza, entre otros campos.

Cyclic fatigue resistance of three reciprocating nickel-titanium instruments with heat treatment at intrachannel temperature

Introduction: the in vitro study compared the dynamic cyclic fatigue resistance of 3 reciprocating NiTi files with heat treatment. Methods: we distributed 30 new endodontic files in three groups. The endodontic files selected for this experiment were: AF Blue R3 25/06 (AFB) (Fanta Dental, Shanghai, China), X1 Blue File 25/06 (X1B) (MK Life, Porto Alegre, RS, Brazil), and Reciproc Blue 08/25 (RB) (VDW, Munich, Germany. We measured the time to file fractureand the length of the fractured fragment. ANOVA analysis was used, followed by the Tukey test for multiple comparisons, with a significance level of 5% (P < 0,05). Results: the mean time in seconds until the file fractured was 170.7 ±15,1 for AFB files, 110,4 ±26,8 for X1B, and 163,3 ±22,9 for RB files. This difference was statistically significant when comparing X1B to AFB (p: 0,000) and X1B to RB (p: 0,000). However, there are no statistically significant differences between RB and AFB (p:0,739). Conclussions: this study found that RB and AFB files exhibit similar resistance to cyclic fatigue.

Introducción: el estudio in vitro comparó la resistencia a la fatiga cíclica dinámica de 3 limas NiTi recíprocas con tratamiento térmico. Métodos: distribuimos 30 limas endodónticas nuevas en tres grupos. Las limas endodónticas seleccionadas para este experimento fueron: AF Blue R3 25/06 (AFB) (Fanta Dental, Shanghai, China), X1 Blue File 25/06 (X1B) (MK Life, Porto Alegre, RS, Brasil), y Reciproc Blue 08/25 (RB) (VDW, Munich, Alemania. Se midió el tiempo transcurrido hasta la fractura de la lima y la longitud del fragmento fracturado. Se utilizó el análisis ANOVA, seguido de la prueba de Tukey para comparaciones múltiples, con un nivel de significación del 5% (P < 0.05). Resultados: el tiempo medio en segundos hasta la fractura de la lima fue de 170.7 ±15.1 para las limas AFB, 110.4 ±26.8 para las X1B y 163.3 ±22.9 para las RB. Esta diferencia fue estadísticamente significativa al comparar X1B con AFB (p: 0.000) y X1B con RB (p: 0.000). Sin embargo, no hay diferencias estadísticamente significativas entre RB y AFB (p:0.739). Conclusiones: en este estudio se ha comprobado que las limas RB y AFB presentan una resistencia similar a la fatiga cíclica.

Orchestrating antigen delivery and presentation efficiency in lymph node by nanoparticle shape for immune response

Activating humoral and cellular immunity in lymph nodes (LNs) of nanoparticle-based vaccines is critical to controlling tumors. However, how the physical properties of nanovaccine carriers orchestrate antigen capture, lymphatic delivery, antigen presentation and immune response in LNs is largely unclear. Here, we manufactured gold nanoparticles (AuNPs) with the same size but different shapes (cages, rods, and stars), and loaded tumor antigen as nanovaccines to explore their disparate characters on above four areas. Results revealed that star-shaped AuNPs captured and retained more repetitive antigen epitopes. On lymphatic delivery, both rods and star-shaped nanovaccines mainly drain into the LN follicles region while cage-shaped showed stronger paracortex retention. A surprising finding is that the star-shaped nanovaccines elicited potent humoral immunity, which is mediated by CD4+ T helper cell and follicle B cell cooperation significantly preventing tumor growth in the prophylactic study. Interestingly, cage-shaped nanovaccines preferentially presented peptide-MHC I complexes to evoke robust CD8+ T cell immunity and showed the strongest therapeutic efficacy when combined with the PD-1 checkpoint inhibitor in established tumor study. These results highlight the importance of nanoparticle shape on antigen delivery and presentation for immune response in LNs, and our findings support the notion that different design strategies are required for prophylactic and therapeutic vaccines.

Three-dimensional reconstruction of femur based on Laplace operator and statistical shape model / 生物医学工程学杂志

Reconstructing three-dimensional (3D) models from two-dimensional (2D) images is necessary for preoperative planning and the customization of joint prostheses. However, the traditional statistical modeling reconstruction shows a low accuracy due to limited 3D characteristics and information loss. In this study, we proposed a new method to reconstruct the 3D models of femoral images by combining a statistical shape model with Laplacian surface deformation, which greatly improved the accuracy of the reconstruction. In this method, a Laplace operator was introduced to represent the 3D model derived from the statistical shape model. By coordinate transformations in the Laplacian system, novel skeletal features were established and the model was accurately aligned with its 2D image. Finally, 50 femoral models were utilized to verify the effectiveness of this method. The results indicated that the precision of the method was improved by 16.8%-25.9% compared with the traditional statistical shape model reconstruction. Therefore, the method we proposed allows a more accurate 3D bone reconstruction, which facilitates the development of personalized prosthesis design, precise positioning, and quick biomechanical analysis.

Comparação entre Reciproc Blue e quatro instrumentos réplicas: aspectos metalúrgicos, geometria, comportamento em torção e flexão / Comparison between Reciproc Blue and four replicalike instruments: metallurgical aspects, geometry, and behavior in torsion and flexion

A introdução da liga NiTi na endodontia proporcionou a fabricação de instrumentos com excelentes propriedades mecânicas, e uma das principais características é a possibilidade de alteração das temperaturas de transformação da liga, o qual pode possibilitar a presença de martensita em temperatura ambiente e consequentemente um efeito memória de forma. Entretanto, alguns dos sistemas comercializados atualmente possuem pouca ou nenhuma informação científica relatando suas propriedades mecânicas, características de design e métodos de fabricação. O objetivo deste trabalho foi comparar características geométricas, metalúrgicas e propriedades mecânicas (resistência à torção e flexão) de instrumentos Reciproc Blue (VDW, Munique, Alemanha), e quatro sistemas reciprocantes réplicas. Um total de 39 instrumentos de cada um dos sistemas reciprocantes, Reciproc Blue (RB), Prodesign R (PDR), V File (VF), V+ File (V+) e Univy One (UO) foram utilizados na pesquisa. O programa de Image J foi utilizado para mensuração dos diâmetros a cada milímetro da parte ativa e da área da seção transversal a 3 mm da ponta dos instrumentos. Imagens de MEV da parte ativa foram realizados para avaliar o acabamento superficial dos instrumentos. A composição atômica, fases presentes e temperaturas de transformação foram verificadas através de EDS, DRX e DSC, respectivamente. A flexibilidade foi aferida através de ensaios de dobramento até 45º conforme a especificação ISO 3630-1, e os ensaios de resistência à torção foram realizados de acordo com a especificação Nº28 ANSI/ADA. Todos os instrumentos apresentaram uma quantidade aproximadamente equiatômica de níquel e titânio. A análise qualitativa das fases cristalinas realizada através de ensaios de DRX, demonstrou a predominância de Fase R em todos os grupos, com exceção do grupo UO que apresenta uma mistura de fase R e martensita B19'. Na avaliação da área da seção, o instrumento RB obteve valores intermediários, os instrumentos PDR e V+ possuem menores valores e os instrumentos VF e UO possuem maiores valores. Observou-se grande impacto da geometria sobre as propriedades mecânicas, sendo que aqueles sistemas que apresentavam menor área que RB (PDR, V+) mostraram-se mais flexíveis e menos resistentes à torção (p<0.05), e o instrumento VF que teve maior área apresentou, como esperado, menos flexibilidade (p<0.05) e resistência torcional semelhante (p>0.05). A única exceção se deu com o sistema UO, que embora apresentasse uma maior área de seção, mostrou-se mais flexível e menos resistente à torção, provavelmente por influência da maior quantidade de martensita presente à temperatura ambiente. Nenhum dos instrumentos réplicas avaliados apresentaram características e comportamento mecânico iguais ao sistema padrão RB. Sugere-se que mais estudos devem ser realizados para a comparação do comportamento clínico destes instrumentos.

The introduction of NiTi alloy in endodontics has allowed the manufacturing of instruments with excellent mechanical properties, and one of the main characteristics is the ability to change alloy's transformation temperature, which can enable the presence of martensite at room temperature and consequently favor a shape memory effect. However, some of the currently marketed systems have limited or no scientific information regarding their mechanical properties, design characteristics, and manufacturing methods. The aim of this study was to compare the geometric characteristics, metallurgical aspects, and mechanical properties (torsional and flexural strength) of Reciproc Blue instruments (VDW, Munich, Germany) with four replica-like reciprocating systems. A total amount of 39 instruments from each reciprocating system, namely Reciproc Blue (RB), Prodesign R (PDR), V File (VF), V+ File (V+), and Univy One (UO), were used in the study. The Image J program was used to measure the diameters at every millimeter along the instruments active portion and the cross-sectional area at 3 mm from the instrument tip. SEM images of the active portion were obtained to evaluate the surface finishing of the instruments. Atomic composition, phases present, and transformation temperatures were determined through EDS, XRD, and DSC analyses, respectively. Flexibility was assessed by bending tests up to 45° according to ISO 3630-1 specifications, and torsional strength tests were performed according with ANSI/ADA Specification No. 28. All instruments exhibited an approximately equiatomic composition of nickel and titanium. Qualitative analysis of the crystalline phases using XRD tests demonstrated the predominance of the R-phase in all groups, except for the UO group, which exhibited a mixture of Rphase and B19' martensite. In terms of diameter and cross-sectional area evaluation, the RB instrument obtained intermediate values, while the PDR and V+ instruments had smaller values, and the VF and UO instruments had larger values. A significant impact of geometry on mechanical properties was observed, with systems exhibiting a smaller area than RB (PDR, V+) being more flexible and less torsion-resistant (p<0.05), and the VF instrument with a larger area showed, as expected, less flexibility (p<0.05) and similar torsional resistance (p>0.05). The only exception was the UO system, which, despite having a larger geometric configuration, exhibited greater flexibility and less torsional resistance, likely due to the higher amount of martensite present at room temperature. None of the replica-like instruments evaluated showed identical characteristics and mechanical behavior to the standard RB system. Further studies are suggested to compare the clinical performance of these instruments.

Influence of solvent choice and operating conditions on Chlorzoxazone crystal shape and size

Abstract Solubility of pharmaceutical drugs in organic solvents is one of the important parameters to understand the equilibrium concentration of solute-solvent, which helps optimize and design crystallization conditions to obtain the desired product crystals. In the present study, Chlorzoxazone (CHZ) is used as a model pharmaceutical compound to investigate the equilibrium solubility, the influence of solvent and the operating conditions on the shape, and the size distribution. The solubility of CHZ is determined in organic solvents like Isopropanol, Ethanol, and 2-Ethoxyethylacetate, Ethylacetate and Ethyllactate using shake flask method from -5ºC to 60ºC. The solubility of CHZ in these solvents shows an increasing trend as the temperature increases in the following order: ethyllactate + water (0.5+0.5) < ethylacetate < isopropanol < ethanol < 2-ethoxyethylacetate < ethyllactate + water (0.75+0.25). The solvents, isopropanol, ethanol, and ethyl lactate, produce needle-shaped crystals, while 2-ethoxyethylacetate and ethyl acetate tend to produce plate shaped crystals. CHZ crystals obtained from 2-ethoxyethylacetate tend to have plate shaped crystals with a lower aspect ratio and are selected for batch cooling crystallization experiments performed at different cooling rates, and agitation. It is found that the agitation at 300 rpm and the cooling rate 0.2ºC/min produce more uniform crystal size distribution

Facial shaping filled with autologous high density fat in zygomatic arch area / 中华医学美学美容杂志

Objective:To explore a simple and effective method to improve the facial shape coordination for patients.Methods:From May 2015 to May 2020, 36 female patients (aged 24-32 years, mean 26.8 years) who were required to change face shape were enrolled in Zhengzhou Mylike Medical Cosmetology Hospital to improve face shape by adjusting frontaI arch width combined with autologous high-density fat transplantation.Results:Thirty-three patients (91.7%) were satisfied (31 satisfied, 2 basically satisfied). Three patients were not satisfied with the filling effect, and two of them were satisfied after the second filling (3 months after operation). 35 of the 36 patients were satisfied, accounting for 97.2%, only 1 case was dissatisfied. No other compIications such as fat liquefaction were observed. The mean morphological surface index of patients was 90.2 before operation and 88.1 after operation, showing significant improvement.Conclusions:Autologous high density fat transplantation is a good method to adjust the coordination of the frontal arch.

Biomechanical Analysis on NiTi Memory Alloy Stent for Lumbar Interbody Fusion / 医用生物力学

Objective To evaluate biomechanical properties of the nickel-titanium (NiTi) memory alloy stent and its in vitro biomechanical properties for lumbar interbody fusion. Methods The mechanical properties of the NiTi memory alloy stent were tested on mechanical testing machine. Moreover, lumbar interbody fusion was simulated on fresh lumbar specimens, and biomechanical properties of the NiTi memory alloy stent with matching bone graft for used for lumbar interbody fusion were analyzed and compared with the traditional box-shape cage. Results The maximum compressive strength of the NiTi memory alloy stent was ( 12 964 ± 962) N. The maximum deformation within the effective range of memory characteristics was (4. 68±0. 03) mm. The recovery rate of the NiTi memory alloy stent was up to 99. 86% . Compared with the intact lumbar model, the stability of the operative segment after the simulated lumbar interbody fusion using NiTi memory alloy stent alone was increased in the direction of anterior flexion, posterior extension, lateral flexion and rotation, which was equivalent to the box shape cage group (P>0. 05). After the combined use of autogenous bone granule and absorbable bone cement the ROM of the operative segment was further reduced (P0. 05). The pull-out strength of the NiTi memory alloy stent with matching bone graft group was significantly stronger than that of the box-shape cage group (P<0. 05). Conclusions The NiTi memory alloy stent in this study was designed with a matched bone granule-absorbable bone cement graft,which provided a new idea for the further optimization and development of lumbar interbody fusion. With excellent support and deformation properties, this NiTi memory alloy stent is biomechanical equivalent to the traditional box shape cage for lumbar interbody fusion, and can greatly improve the stability of surgical segment and the pull-out strength of implants after the combined use of autogenous bone granule and absorbable bone cement.

Anatomical Observation of Different Shapes of Foramen Magnum and Its Clinical Implications: A Study in Dry Adult Human Skulls of Indian Population

Background: Understanding of thoroughly explained anatomical basis is must for various surgical approaches at the craniovertebral junction. High mortality and morbidity are anticipated during the surgical procedures when undertaken without in depth anatomical knowledge. With so much clinical importance in this area, our study will present a thorough understanding in terms of skull. Objectives: The aim of the present study is to evaluate the various shapes of foramen magnum in dry adult human skulls of Indian population and to find out their clinical correlation. Materials and methods: 347 dried adult human skull base obtained from the Department of Anatomy, Geetanjali Medical College and Hospital, Udaipur, Rajasthan and other medical colleges were used in the present study. All the dry adult human skulls were observed from outer side at their base by naked eyes to determine the shape of foramen magnum. It was classified into one of the following shapes: - Oval, round, tetragonal, egg shaped, hexagonal, pentagonal and irregular. Results: The shape of the foramen magnum in dry skulls were oval in 44.95%, round in 30.84%, hexagonal in 9.23%, irregular in 6.63%, pentagonal in 5.19%, tetragonal in 1.73 %, and egg shaped in 1.44%. Conclusion: Inferences of the present study in the form of variations in the shapes of foramen magnum will be useful to the neurosurgeons, radiologists, orthopedics, anthropologists, forensic experts as well as anatomists. Further these data can be used as an anatomical reference for the researchers.

Single center experience of transcatheter closure of mitral and aortic Paravalvular leaks using the new rechristened rectangular Amplatzer PVL plug

Amplatzer Paravalvular leak (PVL) plug is rectangular in shape, that might suit closure of crescentic PVL. Among 79 transcatheter PVL closures from a single center, a subgroup of 16 patients who received Amplatzer PVL plugs were analyzed. All procedures were successful, as the plug auto-oriented to the leak, without mechanical leaflet interference, though needing additional 31 devices. Two patients needed an elective re-intervention. NYHA class improved from III-IV before procedure to less than II after procedure. Complications were not directly related to the Amplatzer PVL plug. The rectangular shape for crescentic leaks, auto-orientation and non-interference with mechanical leaflets were good attributes.

Modelización del tiempo que tarda un paciente con cáncer diferenciado de tiroides en presentar la primera recaída / Modeling of the Time it Takes for a Patient with Differentiated Thyroid Cancer to Present the First Relapse / Modelagem do tempo que um paciente com câncer diferenciado de tireoide leva para apresentar a primeira recidiva

Introducción: de todos los carcinomas de tiroides, los diferenciados son los predominantes. Según la Asociación Colombiana de Endocrinología, la tasa de recaída puede ser de hasta del 30 %, especialmente en pacientes mayores de 45 años y con características tumorales agresivas. En esta investigación se estimó el tiempo libre de enfermedad que transcurre entre la finalización del tratamiento y la ocurren-cia de la primera recaída. Materiales y métodos: se tomó un archivo de datos con los registros de 469 pacientes con cáncer diferenciado de tiroides (cdt) tratados en una clínica especializada de cuarto nivel de complejidad en Bogotá (Colombia). Los datos se recolectaron entre enero de 1997 y diciembre de 2012 y se analizaron estadísticamente usando modelos paramétricos y no paramétricos para obtener las curvas de supervivencia y riesgo. Resultados: con el método no paramétrico se evidenció que en 8.5 años el 75 % de los pacientes no habrán presentado la primera recaída en cdt; mientras que en el método paramétrico el 50 % de los pacientes que no presentaron una tiroglobulina postratamiento menor o igual a 1 ng/mL y un tamaño del tumor menor o igual a 2 cm, su tiempo estimado de la primera recaída fue 29.2 años. Conclusiones: el tiempo libre de enfermedad y el riesgo de hacer recaída para pacientes con cdt está afectado por la presencia de un tamaño de tumor mayor a 2 cm en el momento de la consulta y una cantidad de tiroglobulina mayor a 1 ng/mL, registrada al terminar el tratamiento.

Introduction: Between all thyroid carcinomas, the differentiated are predominant. According to the Colombian Association of Endocrinology, the relapse rate can be up to 30%, especially in patients older than 45 years old and with aggressive tumor characteristics. In this investigation, the time that elapses between the initial surgical treatment and the first relapse of the disease was estimated. Materials and methods: A data file was taken with the records of 469 patients with differentiated thyroid cancer (cdt) treated in a specialized clinic of fourth level of complexity iv in the city of Bogotá (Colombia). Data were collected between January 1997 and December 2012 and were statistically analyzed using para-metric and non-parametric models to obtain survival curves and risk. Results: With the non-parametric method, it is evident that in 8.5 years 75% of the patients will not have presented the first relapse in cdt. While applying the parametric method 50% of patients who do not have a postreatment thyroglobulin or one less than or equal to 1 ng/mL and a tumour size less than or equal to 2 cm, their estimated time of First relapse was 29.2 years. Conclusions: Disease-free time and the risk of relapse for patients with cdt is affected by the presence of a tumor size greater than 2 cm at the time of consultation and levels of thyroglobulin greater than 1 ng/mL, recorded at the end of the treatment.

Introdução: de todos os carcinomas da tireoide, os diferenciados são os predominantes. Segundo a Associação Colombiana de Endocrinologia, a taxa de recaída pode ser até 30%, principalmente em pacien-tes com mais de 45 anos e com características de agressividade tumoral. Nesta investigação, estimou-se o tempo decorrido entre o tratamento cirúrgico inicial e a primeira recaída. Materiais e métodos: tomou-se um arquivo de dados com os prontuários de 469 pacientes com câncer diferenciado de tireoide (cdt) atendidos em uma clínica especializada de quarto nível de complexidade na cidade de Bogotá (Colombia). Coletaram-se os dados entre janeiro de 1997 e dezembro de 2012, que depois foram analisados estatisti-camente usando modelos paramétricos e não paramétricos para encontrar curvas de sobrevida e risco. Resultados: com o método não paramétrico, evidenciou-se que, em 8,5 anos, 75% dos pacientes não terão apresentado a primeira recaída na cdt. Enquanto na aplicação do método paramétrico, 50% dos pacientes que não apresentaram tireoglobulina pós-tratamento ou valores menores ou iguais a 1 ng/mL e tamanho do tumor menor ou igual a 2 cm, seu tempo estimado de primeira recaída foi de 29,2 anos. Conclusões: o tempo livre de doença e o risco de recaída, para pacientes com cdt são afetados pela presença de tama-nho de tumor maior a 2 cm no momento da consulta e uma quantidade de tireoglobulina maior a 1 ng/mL, registrada ao terminar o tratamento.

A comprehensive yoga programme for weight reduction in children & adolescents with obesity: A randomized controlled trial

Background & objectives: Obesity is a rising pandemic in childhood. There is scarcity of evidence on the efficacy of yoga in achieving weight loss in overweight/obese children. The objective of this study was to assess the efficacy of family-based comprehensive yoga intervention in the reduction of body mass index (BMI) in overweight/obese children, in comparison to standard dietary and lifestyle counselling and control group. Methods: This was an open-label randomized controlled study. Children aged 8-15 yr who were overweight or had obesity were randomized to one of the three arms for 18 wk; standard weight management (group 1), yoga with dietary modification (group 2) and control (no intervention; group 3). Reduction in BMI and improvement in physiological, biochemical and psychological parameters from baseline to 18 wk was compared between the three arms. Late follow up was also done at 6-12 months. Results: A total of 165 children with mean±standard deviation (SD) age of 11.6±1.8 yr and mean BMI 26.3±4.2 kg/m2 were enrolled. Outcome analysis at 18 wk was performed for 109 children. Improved diet quality and reduced intake were observed in both intervention arms. The median (IQR) reduction in BMI in standard and yoga arms was similar [?1.4 (?3.1, ?0.5) kg/m2 and ?1.2 (?2.3, ?0.6) kg/m2, respectively], while it increased by +0.3 (?0.3, 0.1) in the control arm. In the yoga arm, mean systolic BP reduced from 118 (10) to 114 (8) mmHg, (P=0.019). In the standard arm, significant improvement in psychological scores was noted. In group 3, the mean fasting glucose increased from 93±10 to 102±12 mg/dl (P<0.001). Interpretation & conclusions: The findings of the present study suggest that yoga in conjunction with dietary modification is equally effective as the standard weight management for BMI reduction in the paediatric age group.

Estimation of lactation curves of Gyr cattle and some associated production parameters in the Colombian low tropic

Background: The Gyr breed is widely used in Colombian low tropic dairy production systems. During the last 10 years, the Asociación Colombiana de Criadores de Ganado Cebú† ASOCEBU, has been leading a dairy milk control program which led to the creation of a dataset that permits to carry out the first analysis of milk yield in Gyr cattle in the country using records from several herds. Objectives: To study milk production dynamics of Gyr cattle in the Colombian low tropic through the estimation of lactation curves and four derived production parameters: total milk yield between 5 and 305 days (TMY305), peak milk yield (PMY), days at peak (DP) and persistency (P). Methods: 13,798 daily milk yield records from 1,510 cows performing in 103 herds were used; the total number of lactations was 2,480. Four models were considered: Wood, Wiltmink, Papajcsik & Bordero, and a second-degree polynomial. Mean square error, mean absolute error, mean square error of prediction, Akaike and Bayesian information criteria were used to select the model better describing each lactation using the majority rule, that is, the model selected by most criteria was the chosen one. The shape of each fitted lactation curve was checked using basic results from calculus which permitted the classification of the estimated curves into two groups: typical and atypical; only typical functions were used to compute the four aforementioned production parameters. Results: The second-order polynomial was the model most frequently selected, while the Papajcsik & Bordero model had the lowest frequency. Average TMY305, PMY, DP and P were 3,489.86 kg, 17.28 kg, 57.17 days, and 0.83, respectively, with coefficients of variation: 0.27, 0.21, 0.41, and 0.16. Conclusions: This study permitted to identify individuals with outstanding phenotypic performance. To the best of our knowledge, this is the first study of this kind involving thousands of lactations from Gyr cows performing in several regions of Colombian low tropic.

Antecedentes: La raza Gyr es ampliamente utilizada en las lecherías de trópico bajo en Colombia. Durante los últimos 10 años, la Asociación Colombiana de Criadores de Ganado Cebú ASOCEBU, ha liderado un programa de control lechero que generó una base de datos que permite llevar a cabo el primer análisis de producción de leche de la raza Gyr en el país, considerando individuos de varias fincas. Objetivos: Caracterizar la dinámica de producción de leche de ganado Gyr en el trópico bajo colombiano mediante la estimación de curvas de lactancia y cuatro parámetros de producción derivados: producción total entre 5 y 305 días (TMY305), pico de lactancia (PMY), días al pico (DP) y persistencia (P) Métodos: Se utilizaron 13.798 registros de producción diaria de leche de 1.510 vacas provenientes de 103 fincas, el total de lactancias fue 2.480. Se consideraron cuatro modelos: Wood, Wiltmink, Papajcsik & Bordero, y un polinomio de segundo grado. Los criterios usados para elegir el modelo que mejor describió cada lactancia fueron: error cuadrático medio, error absoluto medio, error cuadrático medio de predicción, criterio de información de Akaike y criterio de información Bayesiano. Se utilizó el criterio de mayoría, esto es, el modelo seleccionado fue aquel elegido por más criterios. La forma de cada una de las curvas de lactancia estimadas fue chequeada utilizando resultados básicos del cálculo, esto permitió clasificar las curvas estimadas en dos grupos: típicas y atípicas; solamente las curvas típicas fueron empleadas para calcular los cuatro parámetros antes mencionados. Resultados: El polinomio de segundo grado fue el modelo que se seleccionó con mayor frecuencia, mientras que el modelo Papajcsik & Bordero tuvo la menor frecuencia. Los promedios para TMY305, PMY, DP y P fueron 3.489,86 kg, 17,28 kg, 57,17 días, y 0,83, respectivamente, con coeficientes de variación 0,27, 0,21, 0,41 y 0,16 Conclusiones: Este estudio permitió identificar individuos con desempeño fenotípico sobresaliente. De acuerdo al estado del arte, este es el primer estudio de este tipo que considera miles de lactancias de vacas Gyr provenientes de varias regiones del trópico bajo colombiano.

Antecedentes: Gir é uma raça Bos indicus amplamente utilizada em sistemas de produção leiteira no trópico baixo Colombiano. A Asociación Colombiana de Criadores de Ganado CebúASOCEBU, lidera um programa de controle de leite nos últimos 10 anos, o que permitiu à coleta de um conjunto de dados para realizar a primeira análise de produção de leite em bovinos Gir no país com informações de vários rebanhos. Objetivo: Estudar a dinâmica da produção de leite por meio da estimativa das curvas de lactação e quatro parâmetros de produção derivados: produção total de leite entre 5 e 305 dias (TMY305), produção de leite no pico de lactação (PMY), dias em produção de leite no pico de lactação (DP) e persistência (P). Métodos: Foram utilizados 13.798 registros de produção diária de leite de 1.510 vacas de 103 fazendas , totalizando 2.480 lactações. Foram considerados quatro modelos: Wood, Wiltmink, Papajcsik & Bordero e um polinômio de segundo grau. Para selecionar o modelo que melhor descreve cada lactação foram utilizados os seguintes critérios: erro quadrado médio, erro absoluto médio, e erro quadrado médio de predição. O modelo selecionado pela maioria dos parâmetros, de acordo com os critérios de informação de Akaike e Bayesiano, foi o escolhido. A forma de cada curva de lactação ajustada foi verificada utilizando os resultados básicos do cálculo, isso permitiu classificar as curvas estimadas em dois grupos: típico e atípico, e apenas funções típicas foram utilizadas para calcular os quatro parâmetros de produção acima mencionados Resultados: O polinômio de segunda ordem foi o modelo mais frequentemente selecionado, enquanto o modelo Papajcsik & Bordero apresentou a menor frequência. A média de TMY305, PMY, DP e P foram 3.489,86 kg, 17,28 kg, 57,17 d e 0,83, respectivamente, com coeficientes de variação de 0,27, 0,21, 0,41 e 0,16. Conclusões: Este estudo permitiu identificar indivíduos com excelente desempenho fenotípico. De acordo com a literatura atual, este é o primeiro estudo envolvendo milhares de lactações de vacas Gir em várias regiões do trópico baixo colombiano.

Valor diagnóstico de indicadores antropométricos para sobrepeso y obesidad / Diagnostic value of anthropometric indicators for overweight and obesity

La obesidad se define por un exceso de masa grasa, sin embargo, hay otros indicadores antropométricos que pueden ser útiles para el diagnóstico de sobrepeso u obesidad; Objetivo. Determinar la exactitud diagnóstica del índice de masa corporal (IMC), circunferencia de la cintura (CC) e índice de forma corporal (ABSI) para el diagnóstico de sobrepeso u obesidad en una población adulta del Ecuador. Materiales y métodos. Se desarrolló un estudio observacional de corte transversal en el que participaron 253 sujetos con edades entre 20 y 60 años. Se midió peso, estatura, circunferencia de la cintura y porcentaje de grasa corporal (PGC). Se correlacionó el PGC con IMC, CC y ABSI y se estableció la sensibilidad y especificidad de estos indicadores para el diagnóstico de sobrepeso u obesidad con curvas ROC. Resultados. El PGC fue menor en hombres que en mujeres (30,9 vs 41,87), ABSI y CC fue mayor en hombres que en mujeres (0,079 vs 0,075) y (99,76 vs 91,25) respectivamente. Se encontró una correlación positiva fuerte (≥0,75) entre el PGC e IMC y CC. En la curva ROC, el área bajo la curva más alta se observa para el IMC (0,949), mientras que el área más baja se observa para ABSI (0,395). Conclusión. El IMC es el indicador con mayor precisión diagnóstica de sobrepeso u obesidad. ABSI no sería un indicador útil en el diagnóstico de sobrepeso u obesidad(AU)

Obesity is defined by an excess of fat mass, however, there are other anthropometric indicators that can be useful for the diagnosis of overweight or obesity; Objetive. To determine the diagnostic accuracy of the body mass index (BMI), waist circumference (WC) and body shape index (ABSI) for the diagnosis of overweight or obesity in an adult population of Ecuador. Materials and methods. An observational cross-sectional study was carried out in which 253 subjects aged between 20 and 60 years participated. Weight, height, waist circumference and percentage body fat (PBF) were measured. The PBF was correlated with BMI, WC and ABSI and the sensitivity and specificity of these indicators were established for the diagnosis of overweight or obesity with ROC curves. Results. The PBF was lower in men than in women (30.09 vs 41.87), ABSI and CC were higher in men than in women (0.079 vs 0.075) and (99.76 vs 91.25) respectively. A strong positive correlation (≥0.75) was found between % body fat and BMI and WC. On the ROC curve, the area under the highest curve is observed for BMI (0.949), while the lowest area is observed for ABSI (0.395). Conclusion. The BMI is the indicator with the highest diagnostic precision of overweight or obesity. ABSI would not be a useful indicator in the diagnosis of overweight or obesity(AU)

F approach algorithm in missing landmark problem / Aproximación al algoritmo F en punto de referencia perdido

SUMMARY: Missing data may occur in every scientific studies. Statistical shape analysis involves methods that use geometric information obtained from objects. The most important input to the use of geometric information in statistical shape analysis is landmarks. Missing data in shape analysis occurs when there is a loss of information about landmark cartesian coordinates. The aim of the study is to propose F approach algorithm for estimating missing landmark coordinates and compare the performance of F approach with generally accepted missing data estimation methods, EM algorithm, PCA based methods such as Bayesian PCA, Nonlinear Estimation by Iterative Partial Least Squares PCA, Inverse non-linear PCA, Probabilistic PCA and regression imputation methods. Landmark counts were taken as 3, 6, 9 and sample sizes were taken as 5, 10, 30, 50, 100 in the simulation study. The data are generated based on multivariate normal distribution with positively defined variance-covariance matrices from isotropic models. In simulation study three different simulation scenarios and simulation based real data are considered with 1000 repetations. The best and the most different result in the performance evaluation according to all sample sizes is the Min (F) criteria of the F approach algorithm proposed in the study. In case of three landmarks which is only the proposed F approach and regression assignment method can be applied, Min (F) criteria give best results.

RESUMEN: Los datos faltantes pueden ocurrir en todos los estudios científicos. El análisis estadístico de formas involucra métodos que utilizan información geométrica obtenida de objetos. La entrada más importante para el uso de información geométrica en el análisis estadístico de formas son los puntos de referencia. Los datos que faltan en el análisis de formas se producen cuando hay una pérdida de información sobre las coordenadas cartesianas históricas. El objetivo del estudio es proponer el algoritmo de enfoque F para estimar las coordenadas de puntos de referencia faltantes y comparar el rendimiento del enfoque F con métodos de estimación de datos faltantes generalmente aceptados, algoritmo EM, métodos basados en PCA como Bayesian PCA, Estimación no lineal por Iterative Partial Least Squares PCA, PCA no lineal inverso, PCA probabilístico y métodos de imputación de regresión. Los recuentos de puntos de referencia se tomaron como 3, 6, 9 y los tamaños de muestra se tomaron como 5, 10, 30, 50, 100 en el estudio de simulación. Los datos se generan en base a una distribución normal multivariada con matrices de varianza-covarianza definidas positivamente a partir de modelos isotrópicos. En el estudio de simulación se consideran tres escenarios de simulación diferentes y se consideran datos reales basados en simulación con 1000 repeticiones. El mejor y más diferente resultado en la evaluación del desempeño según todos los tamaños de muestra es el criterio Min (F) del algoritmo de enfoque F propuesto en el estudio. En el caso de tres puntos de referencia, que es solo el enfoque F propuesto y se puede aplicar el método de asignación de regresión, los criterios Min (F) dan mejores resultados.