Analysis of the feasibility of measurements and characteristics of intraocular lens tilt using swept-source optical coherence tomography biometer / 中华实验眼科杂志

Objective:To evaluate the feasibility of measurement and characteristics of intraocular lens (IOL) tilt using the swept-source optical coherence tomography (SS-OCT) biometer (IOLMaster 700) and to explore its potentially relevant parameters.Methods:A cross-sectional study was conducted.Two hundred and forty-two eyes (119 right eyes, 123 left eyes) of 185 patients after phacoemulsification and IOL implantation were included in Beijing Tongren Hospital from July to September 2018.The IOL position, angle κ, angle α, corneal curvature, anterior chamber depth (ACD), pupil diameter (PD), and axial length (AL) were obtained by IOLMaster 700, and the IOL tilt direction and magnitude were calculated.The within-subject standard deviation and intraclass correlation coefficient were used to evaluate the repeatability of three IOL tilt measurements.Binocular symmetry of IOL tilt and the correlation between IOL tilt and different influencing factors were evaluated by Pearson linear correlation analysis or Spearman rank correlation analysis.Influencing factors for IOL tilt were assessed by multiple linear regression analysis.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of Beijing Tongren Hospital, Capital Medical University (No.TRECKY2018-049). Patients were informed of the purpose and methods of this study and signed the written informed consent.Results:The repeatability of IOL tilt measurements was excellent with a within-subject standard deviation of 5.16° for IOL tilt direction and 0.13° for IOL tilt magnitude.IOL tilt was mirror symmetric in both eyes.The IOL tilt direction in right eyes ranged from -89.60° to 87.53° with a mean of (18.85±29.65)°, and the tilt magnitude ranged from 1.32° to 7.05° with a mean of (4.16±1.26)°.The IOL tilt direction in left eyes ranged from -84.30° to 89.44° with a mean of (21.17±32.38)°, and the tilt magnitude ranged from 0.58° to 7.40° with a mean of (3.80±1.31)°.There were moderate and weak positive correlations of IOL tilt direction and tilt magnitude between both eyes ( r=0.473, P<0.001; r=0.335, P=0.011). IOL tilt magnitude was weakly positively correlated with angle α and IOL diopter ( rs=0.272, P=0.003; r=0.285, P=0.002), and was weakly negatively correlated with ACD, PD and AL ( r=-0.303, P=0.001; r=-0.233, P=0.011; rs=-0.331, P<0.001). In backward stepwise regression analysis, the regression equation of IOL tilt magnitude, angle α, ACD, PD, AL and IOL diopter in multiple linear regression analysis was as follows: IOL tilt magnitude=10.503+ 1.456×angle α-0.532×ACD-0.196×AL ( R2=0.400; F=8.588, P<0.001). Conclusions:The SS-OCT biometer can be an effective method to assess IOL tilt.IOL tilt is mirror symmetric between the right eyes and left eyes.

The Challenges And Pitfalls Of Limb-Leads And Heart-Axis Calculations - The Differences Between the Overall Magnitudes of Bipolar and Augmented Unipolar Leads cannot be Explained with the Ohm's Law

Summary Our paper analyses the interdependence between the overall magnitudes and resistances of bipolar and augmented unipolar limb leads of electrocardiograms. The findings strongly indicate that the overall ratio of magnitude of the bipolar and augmented unipolar limb leads is not a constant value, whereas the overall ratio of resistance is a constant value. These results expand but partially contradict a previous study. The ratio of the magnitude of bipolar leads to augmented unipolar leads is between 1 and 4/3 with a mean value of 2/?3, and this ratio is a function of the electrical axis of the heart. Our results also show that the overall ratio of resistance between bipolar and augmented unipolar limb leads approaches the value of 4/3. Conclusively, the ratio of magnitudes between limb leads is not a constant value, the ratio of resistances can be assumed as a constant value and therefore the difference of magnitudes between limb leads cannot be explained with the Ohm's law.

Factors Associated with Maternal Near-miss Among Women Admitted in A Rural Hospital: A Single-Center Study

Background: Maternal Near-miss (MNM) is one of the related concepts to maternal mortality. MNM is a special category of survivors, whose stories provide unique insights and valuable information on maternal mortality. Characterizing near-miss morbidity is valuable for monitoring the quality of hospital-based obstetric care and should be calculated regularly for planning, monitoring, and evaluating provided maternal healthcare. Objectives: The study aimed to observe the factors like patterns and predictors related to maternal near-miss in our demographic.Material & Methods:This cross-sectional observational study was conducted at the Department of Obstetrics and gynaecology, Sirajgonj Medical College and Hospital, Sirajgonj, Bangladesh. The study duration was 1 year, from June 2019 to May 2020. During the study period, a total of 1277 deliveries were conducted at the study hospital, among which, 69 cases were of MNM. Results:The rate of maternal near-miss in our study was 5.41% of the total admitted maternal pregnancy cases. The maternal near-miss mortality ratio (MNM: 1 MD) was 1:13.8. Out of the 69 near-miss cases, 82.6% of women met the MNM criteria already at admission, and another 17.4% of near-miss cases were distributed: 10.1% developed near-miss after admission within the first 12 hours of the hospital admission, whereas the occurrence of MNM after 12 hours of the hospital admission was observed in 7.3% of cases. Conclusions:MNM cases are alarmingly high. Hypertensive disorders of pregnancy and obstetric hemorrhage were the two main direct obstetric causes of near-misses that require strict and quick management protocols. A proper antenatal check-up to discourage early marriage and pregnancy and timely referral to well-equipped health facilities with logistic support is necessary for saving human life.

Metacontingências e Autocontrole Ético: Efeito das magnitudes das consequências individuais e culturais / Metacontingencies and Ethical Self-Control: Effect of magnitudes of individual and cultural consequences

Resumo O objetivo deste trabalho foi avaliar o efeito da manipulação das magnitudes das consequências individuais e culturais sobre o padrão de escolhas em situações de autocontrole ético e metacontingências. Seis estudantes universitários foram divididos em duas microculturas, uma com delineamento ABCAC'B'A e outra com um delineamento AC'B'ABCA. Nas condições B e B', a magnitude da consequência individual para respostas impulsivas aumentava enquanto a consequência cultural diminuía. Nas condições C e C', aumentava a magnitude da consequência cultural e diminuía a consequência individual. Os resultados indicaram a seleção de um padrão de escolhas em ambas as microculturas pela consequência cultural, com pouca ou nenhuma influência da manipulação da magnitude das consequências.

Abstract The objective of this study was to evaluate the effect of the magnitudes of the individual and cultural consequences on the pattern of choices in situations of ethical self-control and metacontingencies. Six college students were divided into two microcultures, one with ABCAC'B'A design and another with an AC'B'ABCA design. In conditions B and B' the magnitude of the individual consequence for impulsive responses increased while the cultural consequence diminished. In conditions C and C' the magnitude of the cultural consequence increased and the individual consequence diminished. The results indicated the selection of a pattern of choices by the groups of both microcultures, according to the cultural consequence, with little or no influence of the manipulation of the magnitude of the consequences.

Evaluación de la respuesta aguda al broncodilatador en pacientes asmáticos sobrepesos y obesos / Evaluation of the acute response to the bronchodilator in overweight and obese asthmatic patients

Introducción: La obesidad está asociada al uso frecuente de medicación de rescate y padecer asma de mayor gravedad. Los obesos asmáticos tienen menor reactividad bronquial, sin embargo, existe información limitada sobre la magnitud de la reversibilidad aguda al broncodilatador (RAB). Objetivo: Evaluar la magnitud de respuesta aguda al broncodilatador en pacientes asmáticos sobrepesos y obesos. Métodos: Se realizó un estudio descriptivo transversal con 49 pacientes asmáticos sobrepesos y obesos atendidos en consulta externa del Hospital Neumológico Benéfico Jurídico (enero 2017˗ enero 2018) y se constató mediante espirometría la respuesta aguda al broncodilatador. Resultados: Predominó la edad (40-59 años), mayor asociación de padecer asma, poca mejoría con la aplicación del broncodilatador. El sexo femenino (20-59 años) presentó mayor número que el masculino y menor reversibilidad al broncodilatador. Los pacientes con antecedentes patológicos familiares de asma o atopia representaron 73,5 por ciento del total. El 76,5 por ciento de los obesos no presentó mejoría con la aplicación del broncodilatador. Predominó la categoría de gravedad persistente moderada. Conclusiones: El sexo femenino tiene más riesgo de padecer asma y no tener mejoría al aplicar el broncodilatador. Los obesos mayores de 40 años tienen mayor riesgo de no presentar reversibilidad aguda al broncodilatador. Los antecedentes patológicos familiares de asma o atopia y personales de otras enfermedades no predisponen a menor reversibilidad aguda al broncodilatador. La gravedad del asma no influye en la reversibilidad aguda al broncodilatador(AU)

Introduction: Obesity is associated with the frequent use of rescue medication and suffering from more severe asthma. Obese asthmatics have less bronchial reactivity, however, there is limited information on the magnitude of acute bronchodilator reversibility. Objective: To assess the magnitude of the acute response to the bronchodilator in overweight and obese asthmatic patients. Methods: A cross-sectional descriptive study was carried out in 49 overweight and obese asthmatic patients seen in the outpatient clinic at Benéfico Jurídico Pneumologic Hospital from January 2017 to January 2018, and the acute response to bronchodilator was verified by spirometry. Results: Age predominated (40-59 years), greater association of suffering from asthma, and little improvement with the use of bronchodilator. The female sex (20-59 years) showed greater number than the male and less reversibility to bronchodilator. Patients with family pathological history of asthma or atopy represented 73.5 percent of the total. 76.5 percent of the obese did not show improvement with the use of bronchodilator. The category of moderate persistent severity predominated. Conclusions: The female sex has greater risk of suffering from asthma and has no improvement when applying bronchodilator. Obese individuals over 40 years of age have higher risk of not having acute reversibility to the bronchodilator. Family pathological history of asthma or atopy and personal history of other diseases do not predispose to less acute reversibility of bronchodilator. The severity of asthma does not influence acute reversibility to bronchodilator(AU)

Magnitude, risk factors and outcome of low birth weight babies admitted to neonatal intensive care unit of a tertiary care centre in Puducherry, India

Background: This study was undertaken to know the magnitude, risk factors and outcome of LBW babies admitted in NICU in a tertiary centre.Methods: This is a hospital based, retrospective study, of LBW babies admitted to NICU of Sri Venkateshwara Medical College hospital and research centre, Puducherry, from Jan 2019 - Dec 2019.Results: About 340 babies were admitted to NICU and 56 were LBW babies, 5 were excluded and 51 LBW babies analysed. Magnitude of LBW babies, 51 (15%). Socio demographic pattern showed, IUGR (62.7%). Term IUGR (52%) and preterm IUGR (9.8%). Preterm babies (37.2%). Preterms <28 weeks of gestation (7.8%), 28-34 weeks (9.8%) and 34 to < 37 weeks (19.6%). LBW babies <1kg (7.8%), 1-1.5kg (1.9%) and 1.5 to 2.49 kg (90.1%). Male (52.9%), female babies (47%). LBW babies from rural area (62.7%), urban area (37.2%). Among the maternal risk factors, maternal anemia was common (31.3%). Elderly primi (13.7%), PROM and twin pregnancy in (9.8%) each, bad obstetric history (7.8%). PIH, APH, GDM and oligohydramnios in (3.9%) each. Rh negative pregnancy, grand multipara, teenage pregnancy, ART with hypothyroidism and unbooked pregnancy seen in (1.9%) each. Fetal distress (19.6%). Morbidity was (92.1%). Most common was jaundice (31.9%), sepsis (21.2%). Feeding difficulties (19.1%), TTNB (17%), apnea of prematurity (14.8%). Hypoglycemia and HIE in (12.7%) each. Hypothermia and HMD in (10.6%) each. Seizures in (8.5%) MAS and NEC (4.2%) each, congenital anomalies and hypocalcemia in (2.1%) and mortality in (7.8%). Extreme prematurity, ELBW with sepsis and RDS being common cause of mortality.Conclusions: Iron tablets intake, nutritional care, regular antenatal checkup, spacing pregnancy, avoidance of teenage and elderly pregnancy is important. Improving the infrastructure, manpower in NICU to manage preterm babies, when surfactant and ventilation is given.

Addressing the health needs of people with disabilities in India

In India, the number of people with disabilities is continuously growing over the past few decades. The figure is expected to increase due to population aging, with a resultant increase in chronic health conditions. The health of people with disabilities is a relatively neglected and ignored area. Further, the disabled face poor access to healthcare and frequently encounter discrimination or stigmatization. These situations make them more vulnerable to many comorbidities in their health, making severe compromises in their quality of life. Therefore, people with disabilities need special healthcare than people without disabilities. There is a need for sensitization of all health-care providers to ensure quality, affordable, and accessible health-care services for people with disabilities. To address the health-care needs of people with disabilities to the maximum, Ministry of Health, Government of India should incorporate appropriate guidelines in various national health programs and work together with a relevant ministry.

Magnitude, Trends and Causes of Maternal Mortality: A 7-year Review at a Tertiary Hospital in Rivers State, Nigeria

Background: Maternal mortality ratios (MMR) are still unacceptably high in many low-and middle-income countries especially in sub-Saharan Africa. Background Data for the causes of maternal deaths are needed to inform policies to improve maternal healthcare and reduce maternal mortality.Objective:This study sought to determine the magnitude and trend in maternal mortality and the causes at a tertiary hospital over a seven-year study period.Methodology:This was a retrospective review of maternal mortality and causes from 2012 to 2018. Data on number of maternal deaths, deliveries and causes of death were retrieved from the departmental annual reports and hospital records and entered into Microsoft Excel 2013.Data were presented as line graphs, chartsand frequency tables.Results:One hundred and ten (110) maternal deaths occurred out of 17,080 total births during the study period giving an overall MMR of 644. The MMR increased progressively from 580 in 2012 to 785 in 2018 with a sharp rise to the highest and subsequent decline to the lowest, values at the midpoint. The commonest causes of maternal deaths were Pre-eclampsia (PET) and Eclampsia 44(40%), Postpartum Haemorrhage (PPH) 25(22.7%) and Ruptured Uterus 13(11.8%).Conclusion: The maternal mortality ratio is high and the trendis worsening. The leading causes of maternal deaths were PET/Eclampsia and Postpartum haemorrhage accounting for about two-thirds of all deaths. Efforts must be geared towards improvements in the management of these cases, if this trend is to be reversed.

Low-magnitude vibration promotes osteogenesis of osteoblasts in ovariectomized osteoporotic rats via the estrogen receptor / 生物医学工程学杂志

The purpose of this study was to investigate the effect of low-magnitude vibration on osteogenesis of osteoblasts in ovariectomized rats with osteoporosis via estrogen receptor α(ERα). The mRNA expression of osteogenic markers were examined with qRT-PCR, based on which the optimal vibration parameter for promoting osteogenesis was determined (45 Hz × 0.9 g, g = 9.8 m/s

Research Progress on Mechanisms of Vibration in Osteogenesis of Bone Mesenchymal Stem Cells / 医用生物力学

Vibration represents a micro reciprocating motion of a particle or object along a line or arc relative to a reference position, while the effect of low-magnitude high-frequency vibration (LMHFV) on skeletal system cells is similar to the mechanical stimulation of muscle movement. Bone mesenchymal stem cells (BMSCs), which have been identified as force-sensitive cells, exist in the bone marrows and have the potential of multi-lineage differentiation. Their biological characteristics can change functionally according to the appropriate stimulation in vitro, in order to reach the optimal demand of the stimulation. LMHFV can promote the osteogenic differentiation of BMSCs, therefore, the research on its mechanism can contribute to the application of vibration in the treatment of diseases such as osteoporosis, fracture, osteogenesis imperfecta, obesity as well as the promotion of orthodontic tooth movement. This paper summarizes the recent progress about the effects of vibration on BMSCs stem cells in osteogenesis and the possible mechanisms, so as to provide research ideas and methods for studying the mechanical as well as biological changes of BMSCs under vibration stimulation.

Research Progress on Mechanisms of Vibration in Osteogenesis of Bone Mesenchymal Stem Cells / 医用生物力学

Vibration represents a micro reciprocating motion of a particle or object along a line or arc relative to a reference position, while the effect of low-magnitude high-frequency vibration (LMHFV) on skeletal system cells is similar to the mechanical stimulation of muscle movement. Bone mesenchymal stem cells (BMSCs), which have been identified as force-sensitive cells, exist in the bone marrows and have the potential of multi-lineage differentiation. Their biological characteristics can change functionally according to the appropriate stimulation in vitro, in order to reach the optimal demand of the stimulation. LMHFV can promote the osteogenic differentiation of BMSCs, therefore, the research on its mechanism can contribute to the application of vibration in the treatment of diseases such as osteoporosis, fracture, osteogenesis imperfecta, obesity as well as the promotion of orthodontic tooth movement. This paper summarizes the recent progress about the effects of vibration on BMSCs stem cells in osteogenesis and the possible mechanisms, so as to provide research ideas and methods for studying the mechanical as well as biological changes of BMSCs under vibration stimulation.

The mediating effect of intelligence between the information processing speed and numerical magnitude in hearing-impaired children / 中华行为医学与脑科学杂志

Objective@#To explore the mediating role of intelligence in the relationship between information processing speed and numerical magnitude processing of hearing-impaired children.@*Methods@#A survey was conducted among 249 hearing-impaired children by using tests of Choice Reaction Time, Numerosity Comparison, and Raven's Progressive Matrices(simplified version).@*Results@#(1)The accurate rate of information processing speed(0.89±0.18)of hearing-impaired children was positively correlated with that of numerical magnitude processing(0.65±0.15)and intelligence(11.83±10.34)(r=0.165, 0.263, both P<0.01). The reaction time of information processing speed was negatively correlated with those of numerical magnitude processing and intelligence(r=-0.164, -0.197, both P<0.05). And there was significant positive correlation between intelligence and numerical magnitude processing (accurate rate and reaction time ) (r=0.269, 0.140, both P<0.05). (2)The accurate rate of information processing speed significantly predicted that of numerical magnitude processing in hearing-impaired children(β=0.17, t=2.64, both P<0.01). The reaction time of information processing speed significantly predicted that of numerical magnitude processing in hearing-impaired children(β=-0.16, t=-2.61, both P<0.05). And intelligence played a complete mediating role in this relationship and the moderating effect were 36.71% and 31.25%.@*Conclusion@#Information processing speed has indirect effects on numerical magnitude processing through intelligence in hearing-impaired children.

The mediating effect of intelligence between the information processing speed and numerical magni-tude in hearing-impaired children / 中华行为医学与脑科学杂志

Objective To explore the mediating role of intelligence in the relationship between in-formation processing speed and numerical magnitude processing of hearing-impaired children. Methods A survey was conducted among 249 hearing-impaired children by using tests of Choice Reaction Time,Numero-sity Comparison,and Raven's Progressive Matrices( simplified version). Results (1) The accurate rate of information processing speed(0. 89±0. 18)of hearing-impaired children was positively correlated with that of numerical magnitude processing(0. 65±0. 15)and intelligence(11. 83±10. 34)(r=0. 165,0. 263,both P<0. 01). The reaction time of information processing speed was negatively correlated with those of numerical mag-nitude processing and intelligence(r=-0. 164,-0. 197,both P<0. 05). And there was significant positive correlation between intelligence and numerical magnitude processing (accurate rate and reaction time ) (r=0. 269,0. 140,both P<0. 05). ( 2) The accurate rate of information processing speed significantly predicted that of numerical magnitude processing in hearing-impaired children( β=0. 17,t=2. 64,both P<0. 01). The reaction time of information processing speed significantly predicted that of numerical magnitude processing in hearing-impaired children(β=-0. 16,t=-2. 61,both P<0. 05). And intelligence played a complete medi-ating role in this relationship and the moderating effect were 36. 71% and 31. 25%. Conclusion Information processing speed has indirect effects on numerical magnitude processing through intelligence in hearing-im-paired children.

A power law study of the edge influence on the perceived filling-in brightness magnitude

Abstract: Background: Edge plays a special role in spatial perception and as well as in determining the brightness of a surface within borders. The aim of our study was to measure threshold brightness in different levels of edges thickness. Methods: Steven's power law for circles modulating in luminance was estimated for 30 subjects (mean age 24 years, SD 3.3, 13 female). Stimuli were presented on the iMac display using the 11-bit graphic board and consisted of two circles of 3° of visual angle, separated by 10°. We tested 7 levels of Michelson contrast: 7, 8, 10, 15, 26, 50, and 100. Three edges filtering were tested (0.3, 0.8, and 1.5° of smoothing). The subjects' task was to judge the brightness of the edge filtered circle compared with the circle of the hard edge which was considered the modulus and received an arbitrary level of 50, representing the amount of brightness perception. In each trial, the same contrast level was presented in both circles. Five judgments were performed for each contrast level in edge filtering. Results: We found an increase in the power law exponent as the increase of the edge filtering (for sigma of 0.3 = 0.43, sigma of 0.8 = 0.73, and sigma 1.5 = 0.97). All power function fitting had high correlation coefficients (r2 = .94, r2 = .95, r2 = .97, respectively to sigma 0.3, 0.8, and 1.5) passing to the model's adhesion criteria. Conclusions: There was a progressive distortion on the figure brightness perception as increasing the edge filtering suggesting the control of edges on the polarity of the overall brightness. Also, perceived brightness was increasingly veridical with increased filtering, approaching 1:1 correspondence at 1.5 sigmas. (AU)

Efeitos da pré-exposição a estímulos de valência afetiva numa tarefa de estimação de magnitude de severidade de comportamentos antissociais / The priming effect of affective valence stimuli in a task of magnitude estimation ofthe severity of antisocial behaviors

Diversos estudos experimentais têm evidenciado a influência do estado afetivo, genericamente entendido, e emocional, em especificidade, no processamento cognitivo. Nesta sequência, tivemos como objetivo analisar o efeito da pré-exposição a estímulos de diferentes valências afetivas - negativa,positiva e neutra - na operação cognitiva de estimação de magnitude numérica da severidade de comportamentos antissociais. Participaram 37 estudantes universitários do mesmo grupo turma, do gênero feminino, entre os 18 e os 24 anos de idade, M = 19.53; DP = 1.06. Foram distribuídas aleatoriamente por três condições experimentais, definidas pela valência dos estímulos: negativa, positiva e neutra. Seguidamente, visualizaram um conjunto de 18 imagens - do IAPS - da valência da respetiva condição experimental, registrando na Self Assessment Manikin o estado afetivo que as imagens produziam. Após um intervalo de quatro minutos, as participantes estimaram a gravidade de 15 comportamentos antissociais. Os resultados indicaram que a pré-exposição de valência negativa teve um efeito significativo de diminuição da estimação da severidade dos comportamentos antissociais, comparativamente como os restantes grupos. Finalmente,procuramos na hipótese da dessensibilização emocional a compreensão dos resultados.

Several experimental studies have emphasized the influence of the affectivestate, generically understood, and emotional state, in specificity, in cognitive processing. In this sequence, we aimed to analyze the effect of pre-exposure to stimuli of different valences ­negative, positive and neutral­ in the cognitive operation of numerical magnitude estimation of antisocial behavior. 37 female university students took part in this study, all from the same class aged between 18 and 24 years, M = 19.53, SD = 1.06. They were randomly distributed in three experimental conditions related to the stimulus valence: negative, positive, and neutral. The participants viewed a series of 18 picturesof the International Affective Picture System of the respective experimental condition, registering into the Self Assessment Manikin the affective state that the images produced. After four minutes of interval, the participants estimated the severity of 15 antisocial behaviors. The results indicated that the negative valence pre- exposure had a significant effect of decreasing the estimation of the severity of antisocial behaviors, comparatively with the other groups. Finally, we discussed the results according to the hypothesis of emotional desensitization.

Low magnitude whole-body vibration and postmenopausal osteoporosis / 生物医学工程学杂志

Postmenopausal osteoporosis is a type of osteoporosis with high bone transformation rate, caused by a decrease of estrogen in the body, which is a systemic bone disease characterized by decreased bone mass and increased risk of fracture. In recent years, as a kind of non-pharmacologic treatment of osteoporosis, defined by whole-body vibration less than 1 ( = 9.81 m/s ), low magnitude whole-body vibration is widely concerned, mainly because of its small side effects, simple operation and relative safety. Studies have shown that low magnitude whole-body vibration can improve bone strength, bone volume and bone density. But a lot of research found that, the therapeutic effects of low magnitude whole-body vibration are different depending on ages and hormone levels of subjects for animal models or human patients. There has been no definite vibration therapy can be applied to each subject so far. Studies of whole-body and cellular level suggest that low magnitude whole-body vibration stimulation is likely to be associated with changes of hormone levels and directed differentiation of stem cells. Based on the analysis of related literature in recent years, this paper made a review from vibration parameters, vibration effects and the mechanisms, to provide scientific basis and clinical guidance for the treatment of postmenopausal osteoporosis with low magnitude whole-body vibration.

Diffusion Tensor-Derived Properties of Benign Oligemia, True “at Risk” Penumbra, and Infarct Core during the First Three Hours of Stroke Onset: A Rat Model

OBJECTIVE: The aim of this study was to investigate diffusion tensor (DT) imaging-derived properties of benign oligemia, true “at risk” penumbra (TP), and the infarct core (IC) during the first 3 hours of stroke onset. MATERIALS AND METHODS: The study was approved by the local animal care and use committee. DT imaging data were obtained from 14 rats after permanent middle cerebral artery occlusion (pMCAO) using a 7T magnetic resonance scanner (Bruker) in room air. Relative cerebral blood flow and apparent diffusion coefficient (ADC) maps were generated to define oligemia, TP, IC, and normal tissue (NT) every 30 minutes up to 3 hours. Relative fractional anisotropy (rFA), pure anisotropy (rq), diffusion magnitude (rL), ADC (rADC), axial diffusivity (rAD), and radial diffusivity (rRD) values were derived by comparison with the contralateral normal brain. RESULTS: The mean volume of oligemia was 24.7 ± 14.1 mm³, that of TP was 81.3 ± 62.6 mm³, and that of IC was 123.0 ± 85.2 mm³ at 30 minutes after pMCAO. rFA showed an initial paradoxical 10% increase in IC and TP, and declined afterward. The rq, rL, rADC, rAD, and rRD showed an initial discrepant decrease in IC (from −24% to −36%) as compared with TP (from −7% to −13%). Significant differences (p < 0.05) in metrics, except rFA, were found between tissue subtypes in the first 2.5 hours. The rq demonstrated the best overall performance in discriminating TP from IC (accuracy = 92.6%, area under curve = 0.93) and the optimal cutoff value was −33.90%. The metric values for oligemia and NT remained similar at all time points. CONCLUSION: Benign oligemia is small and remains microstructurally normal under pMCAO. TP and IC show a distinct evolution of DT-derived properties within the first 3 hours of stroke onset, and are thus potentially useful in predicting the fate of ischemic brain.

Effect of simulated transportation vibration on suspended erythrocyte quality / 军事医学

Objective To investigate the effect of vibration on the quality of suspended erythrocytes during transportation, and explore suitable experimental vibration conditions.Methods Three intensities(highway truck vibration, random vibration of fixed goods in a caterpillar, and combined wheeled vehicle vibration)were selected to simulate suspended erythrocyte transportation using electromagnetic vibration test system.Suspended erythrocytes of the same storage were randomly divided into three groups:highway truck vibration(group1),random vibration of fixed goods in a caterpillar(group 2),and combined wheeled vehicle vibration(group 3).The suspended erythrocytes were stored for 11 days and 26 days.The control group was stored with conventional methods.Suspended erythrocytes were vibrated for 1 hour,samples were collected before and after vibration,while free hemoglobin(FHb),K+,and LDH were tested.Results The changes in FHb and LDH after vibration were gradually increased with the magnitude of vibration(P<0.05).There was no significant difference in K +between the three vibration levels.The increase in FHb in suspended erythrocytes stored for 26 days was higher than 11days after random vibration of fixed goods in a caterpillar and combined wheeled vehicle vibration(P<0.05).There was no significant difference in the change in FHb between day(d)26 and d 11 after highway truck vibration.Under the same magnitude of vibration,the change in LDH in the d 26 suspended erythrocytes was more significant than that of the d 11, and no significant difference was found in the change in K +between d 26 and d 11. Conclusion The damage to suspended erythrocytes after combined wheeled vehicle vibration is more obvious than that by the other two vibrations.The vibration environment of combined wheel vehicles is more suitable for simulating the vibration damage to suspended erythrocyte vibration.Suspended erythrocytes with a longer storage time have significant changes in FHb and LDH after transportation vibration, and the length of storage time of suspended red blood cells might affect the vibration injury.

Differentiation of the Infarct Core from Ischemic Penumbra within the First 4.5 Hours, Using Diffusion Tensor Imaging-Derived Metrics: A Rat Model

OBJECTIVE: To investigate whether the diffusion tensor imaging-derived metrics are capable of differentiating the ischemic penumbra (IP) from the infarct core (IC), and determining stroke onset within the first 4.5 hours. MATERIALS AND METHODS: All procedures were approved by the local animal care committee. Eight of the eleven rats having permanent middle cerebral artery occlusion were included for analyses. Using a 7 tesla magnetic resonance system, the relative cerebral blood flow and apparent diffusion coefficient maps were generated to define IP and IC, half hour after surgery and then every hour, up to 6.5 hours. Relative fractional anisotropy, pure anisotropy (rq) and diffusion magnitude (rL) maps were obtained. One-way analysis of variance, receiver operating characteristic curve and nonlinear regression analyses were performed. RESULTS: The evolutions of tensor metrics were different in ischemic regions (IC and IP) and topographic subtypes (cortical, subcortical gray matter, and white matter). The rL had a significant drop of 40% at 0.5 hour, and remained stagnant up to 6.5 hours. Significant differences (p < 0.05) in rL values were found between IP, IC, and normal tissue for all topographic subtypes. Optimal rL threshold in discriminating IP from IC was about -29%. The evolution of rq showed an exponential decrease in cortical IC, from -26.9% to -47.6%; an rq reduction smaller than 44.6% can be used to predict an acute stroke onset in less than 4.5 hours. CONCLUSION: Diffusion tensor metrics may potentially help discriminate IP from IC and determine the acute stroke age within the therapeutic time window.

Valor de la Recompensa: ¿Cómo y Para Qué se Usa el Concepto? / Value of the Reward: How Is the Concept Used and for What? / Valor de Recompensa: como e para que se usa o Conceito?

El escrito ofrece un panorama general sobre el valor de la recompensa, respondiendo los interrogantes: ¿qué es?, ¿cómo se ha conceptualizado? y ¿qué investigaciones han utilizado el concepto? En sentido general, este se utiliza para calificar una recompensa como más o menos efectiva: mientras mayor sea el valor, mayor es su eficacia. Primero se describe la medición histórica del valor y cómo lo define la literatura sobre economía conductual. A continuación aparecen dos usos diferentes del concepto: (a) como constructo hipotético y (b) como variable interviniente. También se incluyen definiciones operacionales, en las que no se definen exhaustivamente las variables asociadas, entonces no se le considera variable interviniente, pero tampoco se agrega significado, más allá del nivel de observación, por lo que no son ejemplo de constructo hipotético. Posteriormente se explora la relación entre demora del reforzador y descuento temporal. Las consideraciones finales retoman la discusión sobre su valor heurístico en la investigación contemporánea.

The article offers a general panorama on the value of the reward, answering the questions: What is it? How has it been conceptualized? What investigations have used the concept? In general, a reward is rated as more or less effective: the greater the value, the greater its efficiency. First, the article discusses the historical measurement of value and how the literature on behavioral economics defines it. Next, two different uses of the concept are presented: (a) as a hypothetical construct and (b) as intervening variable. The text includes operational definitions where the associated variables are not defined exhaustively and therefore not considered as intervening variable, but which also add no meaning beyond the level of observation and therefore are not an example of a hypothetical construct. The article then explores the relationship between delay of the reinforcing agent and temporal discount. Finally, the article considers the discussion about the concept's heuristic value in contemporary research.

Este texto oferece um panorama geral sobre o valor da recompensa ao responder aos questionamentos: o que é, como vem sendo conceituado e quais pesquisas têm utilizado o conceito? Em sentido geral, este se utiliza para qualificar uma recompensa como mais ou menos efetiva: quanto maior for o valor, maior será sua eficácia. Primeiramente, descreve-se a medição histórica do valor e como a literatura sobre economia comportamental o define. A seguir, aparecem dois usos diferentes do conceito: (a) como construto hipotético e (b) como variável interventora. Também são incluídas definições operacionais, nas quais não se definem exaustivamente as variáveis associadas, portanto não é considerada variável interventora nem se agrega significado mais além do nível de observação, razão pela qual não são exemplos de construto hipotético. Posteriormente, explora-se a relação entre demora do reforçador e desconto temporal. As considerações finais retomam a discussão sobre seu valor heurístico na pesquisa contemporânea.