Research progress on the treatment of gingival pigmentation / 口腔疾病防治

@#Gingival pigmentation is a nonplaque gum disease. Patients are often afraid to communicate with others because of gum color problems, which affect the social and mental health of patients. The commonly used treatment methods for gingival pigmentation include scalpel excision, gingival grinding, laser therapy, cryosurgery and electrosurgery. In this paper, the progress of gingival pigmentation treatment was reviewed in terms of bleeding, pain, tissue healing and recoloring. The results showed that the clinical effect of laser treatment was better. Among them, the semiconductor laser had more advantages in reducing bleeding, pain and the restaining rate, while the Er:Cr:YSSG/Er:YAG laser performed better for promoting tissue healing. Clinicians can choose the best kind of laser to use according to the actual situation. For patients with thin gingival biotypes, floating gingival transplantation or substitute materials can be selected to restore the gingival morphology. With the in-depth study of melanin regulation mechanisms, various drugs, such as ascorbic acid, natural peptides, synthetic peptides and derivatives, may be the main research direction for the treatment of gingival pigmentation in the future.

Probable awake bruxism - prevalence and associated factors: a cross-sectional study

ABSTRACT Introduction: Bruxism is defined as a repetitive activity of masticatory muscles, characterized by the clenching or grinding of the teeth, which can occur during wakefulness (awake bruxism) or during sleep (sleep bruxism). Objectives: The objectives of the present study were to determine the prevalence of awake bruxism and its associated factors. Methods: Sample was composed by 50 participants of both genders, aged between 18 and 60 years, submitted to a clinical examination - to observe the presence of tooth wear, marks on the mucosa, or masseter muscles hypertrophy - and self-applied questionnaires, which evaluated the presence of TMD signs and symptoms, oral behaviors, lifestyles, anxiety level and sleep quality. Results: The prevalence of awake bruxism was 48%. Its presence was statistically and significantly associated with the presence of signs and symptoms of TMD (p=0.002), poor sleep quality (p=0.032), buccal mucosa indentations (p<0.001) and tongue (p=0.011). Age, gender, social characteristics, habits (such as coffee ingestion, smoking, alcoholism and physical activity) and tooth wear were variables that had no significant association with awake bruxism. Conclusions: It was concluded that awake bruxism shows a high prevalence and a positive association with signs and symptoms of TMD and worst sleep quality. In addition, awake bruxism is more likely to occur in individuals who have buccal mucosa indentation and who present high rates of oral habits and oral behaviors.

RESUMO Introdução: O bruxismo é definido como a atividade repetitiva dos músculos mastigatórios, e pode ocorrer durante o período acordado (bruxismo em vigília) ou durante o sono (bruxismo do sono). Objetivo: O presente estudo teve como objetivo avaliar a prevalência de bruxismo em vigília e seus fatores associados. Métodos: A amostra foi composta por 50 participantes, de ambos os sexos, com idades de 18 a 60 anos, avaliados por meio de minucioso exame clínico - para observar se havia presença de sinais como desgaste dentário, indentações na mucosa, hipertrofia do músculo masseter - e de questionários autoaplicáveis que visaram avaliar a presença de sinais e sintomas de disfunção temporomandibular (DTM), os comportamentos orais e hábitos de vida, o nível de ansiedade e a qualidade de sono dos participantes. Resultados: A prevalência de bruxismo em vigília foi de 48%. Sua presença foi associada, estatística e significativamente, com a presença de sinais e sintomas de DTM (p=0,002), má qualidade do sono (p=0,032), e indentações na mucosa jugal (p<0,001) e língua (p=0,011). Por outro lado, a idade, sexo, características sociais, hábitos (como ingestão de café, fumo, álcool e prática de atividade física), e o desgaste dentário foram variáveis que não tiveram associação com o bruxismo em vigília. Conclusão: Diante disso, conclui-se que o bruxismo em vigília possui uma prevalência significativa e uma associação positiva com DTM e qualidade do sono. Além disso, o bruxismo em vigília apresenta maior probabilidade de acontecer em indivíduos com indentação de mucosa jugal e com alta prevalência de hábitos e comportamentos orais.

Particle design for improving content uniformity of Hewei Jiangni Capsules / 中国中药杂志

Targeting the poor powder characteristics of the contents in Hewei Jiangni Capsules, this study characterized the powder properties of the contents and employed particle design technique for improving the content quality. The content composite particles of Hewei Jiangni Capsules prepared by the particle design technique were evaluated by scanning electron microscopy(SEM), followed by infrared ray(IR), content uniformity, and in vitro dissolution detection. It was found that there was a good correlation between the crushed particle size of slices and the crushing time, and the calcined Haematitum was responsible for the poor content uniformity. After the fine powder of calcined Haematitum was super-finely ground for 8.5 min and those of the other contents in the capsule for 1 min, they were prepared into the composite particles, whose property characterizations were compared with those of the physical mixtures. The content uniformity of the prepared composite particles was significantly improved, and the preparation process was stable and reliable. The adoption of particle design technology to correct the poor uniformity of the physical mixture, solve the pharmaceutical defects of Hewei Jiangni Capsules, and improve the quality of prescriptions has provided important reference for the clinical application and development of Chinese medicinal preparations.

Preparation and in vitro and in vivo evaluation of oral curcumin nanocrystalline capsules / 中国药科大学学报

@#The poorly water-soluble drug curcumin was prepared into oral nanocrystalline solid preparation by nanocrystal technology to improve the solubility, dissolution rate, and bioavailability. Curcumin nanocrystals were prepared by media grinding technology, and two types of stable curcumin nanocrystal suspension formulations were developed. The stabilizers in the two formulations were polyvinylpyrrolidone (PVP K30)/sodium lauryl sulfate (SDS)(1∶1) and Tween 80, respectively. The prepared curcumin nanocrystal suspension was loaded onto microcrystalline cellulose pellets through fluidized bed coating technology, and the nanocrystalline capsules were obtained after filling. The results of nanocrystal redispersion stability and scanning electron microscope (SEM) showed that the morphology of drug-loaded pellets was uniform when PVP K30 and SDS were used as stabilizers, and the diameter of nanocrystals before and after redispersion was about 200 nm, which was determined as the optimal formulation. In vitro dissolution study showed that curcumin nanocrystals at the size of 200 nm exhibited significantly promoted dissolution. The results of X-ray powder diffraction (XRPD) and differential scanning calorimetry (DSC) showed that the curcumin crystalline partly turned amorphous during the preparation of nanocrystals.Pharmacokinetic studies in rats showed that the bioavailability of curcumin nanocrystals was 9.3 times higher than that of the bulk drug. The curcumin nanocrystalline capsules developed in this research can significantly improve the dissolution rate and bioavailability, which is of great significance in improving the poor solubility of drugs, and is expected to become a new dosage form for clinical treatment.

Bruxismo en niños y adolescentes: Revisión de la literatura / Bruxism in Children and Adolescents: A Review of the Literature

Resumen: El bruxismo se define como una actividad repetitiva de los músculos masticatorios caracterizada por apretar o rechinar los dientes y/o por golpear y balancear la mandíbula. Es de etiología multifactorial y se considera que existe un bruxismo fisiológico necesario para el desarrollo de la cara de los niños. Estos dos aspectos hacen complicado el diagnóstico que se basa fundamentalmente en un cuestionario a los padres y en el examen clínico del niño. Cuando el desgaste fisiológico no se diferencia a tiempo del desgaste parafuncional, trae consecuencias negativas en el niño que alteran su calidad de vida, necesitando un manejo multidisciplinario adecuado. Considerando que es necesario conocer características fundamentales del bruxismo infantil, el objetivo del presente artículo de revisión es realizar una actualización sobre sus manifestaciones circadianas, clasificaciones, prevalencia, etiología, factores de riesgo, diagnóstico y tratamiento que servirá al odontólogo para una temprana identificación y tratamiento.

Abstract: Bruxism is defined as a repetitive activity of the chewing muscles characterized by clenching or grinding of the teeth and/or by striking and swinging the jaw. It is of multifactorial etiology and it is considered that there is a physiological bruxism necessary for the development of the face of children. These two aspects complicate the diagnosis that is fundamentally based on a questionnaire to the parents and on the clinical examination of the child. When the physiological wear does not differentiate in time from the parafunctional wear, it has negative consequences in the child that alter their quality of life, requiring an adequate multidisciplinary management. Considering that it is necessary to know the fundamental characteristics of bruxism in children and adolescents, the objective of this review article is to update its circadian manifestations, classifications, prevalence, etiology, risk factors, diagnosis and treatment that will serve the dentist for the early identification and treatment.

Clinical effect of facial dermabrasion by microcrystal combined with red light blue in the treatment of acne pitting scar / 中华医学美学美容杂志

Objective To investigate the clinical effect of facial dermabrasion by microcrystal combined with red blue light in the treatment of acne pitting scar.Methods Selected from June 2013 to April 2016 hospital dermatology outpatients,98 cases of facial acne pitting scar were retrospectively analyzed,in which 50 cases of patients with facial acne dermabrasion were treated with red and blue light treatment (combined group),48 patients only choose facial acne dermabrasion treatment (control group),then treatment effect was compared between the two groups.Results At 3 months after operation,the ECCA score and mean sag depth of the two groups were significantly lower than those of the preoperative (t=23.208 and 18.586,P＜0.001).The ECCA score of the combined group was significantly lower than that of the control group (t=7.039,P＜0.05);The healing rate was 80％,which was significantly higher than those in the control group (56.25％) (x2 =6.387,P＜0.05);after 1 months and 3 months;the subjective satisfaction scores of the patients in the combined group were significantly higher than those in the control group (t=3.318 and 3.776,P＜0.05);Patients in the combined group were significantly earlier than the control group (t =4.419,P＜0.05);the incidence of edema and erythema was significantly lower in the combined group than in the control group (x2 =5.096,P＜0.05).Conclusions Facial acne dermabrasion by microcrystal combined with red and blue light treatment is superior to the single use of dermabrasion.

Four-dimensional space events of fracture healing / 中国组织工程研究

BACKGROUND: Fracture fixation and surgical procedures have a very important impact on the final outcome of fracture healing, but the adverse outcome of fracture healing is the result of the combined action of surgical procedures and a series of four-dimensional space events. OBJECTIVE: To explore the four-dimensional space events in fracture healing. METHODS: China National Knowledge Infrastructure and Medline were retrieved, with the key words of “fracture healing, femoral fracture, stress shielding, fracture and blood flow” in Chinese and English. Retrieval of relatively macroscopic factual descriptions corresponds to the four-dimensional space events of fracture healing process, including logically supported and refuted evidence. Combined with literature review, the main four-dimensional space events after fracture fixation were analyzed. RESULTS AND CONCLUSION: The main four-dimensional space events after fracture fixation include blood flow tides, mechanical and biological impulses, grinding disc effect of small gap in hard tissue, stress shielding effect and four-dimensional space drift effect of internal fixation material. Fractures and surgical trauma are accompanied by months of super-compensatory blood flow tides, so there is no ischemia in the macro-level after fracture surgery, but the grinding disc effect will occur in the small gap of hard tissue under unstable condition, resulting in contusion injury and micro-ischemia in the fracture gap. Stress shielding effect caused by too strong fixation is an important reason for refracture after internal fixation removal and bone atrophy and thinning after internal fixation. The small axial drift of plate fixation screw may have important theoretical significance. It has “intelligent” axial dynamic effect, which can make the stress shared by plate gradually decrease with the healing of fracture. Discussing the four-dimensional space events of fracture healing will provide basic logic for the regulation of fracture healing and distraction osteogenesis.

Preparation and in vitro release study of ligustrazine pamoate sustained-release nanosuspension / 中草药

Objective: To prepare ligustrazine pamoate (Lig-PAM) sustained-release nanosuspension (Lig-PAM-NSps) and determine its in vitro release characteristics. Methods: Lig-PAM was prepared by hydrophobic salt formation method and its physicochemical properties were characterized. Then, Lig-PAM-NSps was prepared by miniaturized medium grinding method. The prescription and preparation process of Lig-PAM-NSps were optimized by the single factor and orthogonal experiment with average particle size, polydispersity index (PDI) and stability coefficient (SI) as indicators. Lig-PAM-NSps was characterized, and its stability and in vitro release was also investigated. Results: The compound ratio of Lig-PAM prepared by Lig and PAM in the amount of 1:1 was (97.48 ± 0.04)%. Compared with Lig, the solubilities of Lig-PAM in water and simulated body fluids were decreased by 95.50% and 77.39%, respectively. Fourier transform infrared spectroscopy (FT-IR) and X-ray powder diffraction (XRD) showed that the Lig and PAM formed Lig-PAM. The optimum prescription size of Lig-PAM-NSps was (585 ± 5) nm, PDI was (0.328 ± 0.015) and SI was (0.928 ± 0.012). The scanning electron microscopy (SEM) showed that Lig-PAM-NSps was spherical with uniform size distribution, and the particle size was about 600 nm and its physical stability was good within 60 d. The results of in vitro release showed that Lig-PAM-NSps had obvious sustained-release effect compared with Lig solution within 48 h, and showed the first-order release characteristics [ln(1-Q) = 0.153 67 t + 80.458 14, r = 0.998 26]. Conclusion: The preparation progress of Lig-PAM-NSps is stable and can release Lig slowly in vitro.

Properties and dissolution of curcumin-PVP co-grinding powder / 中草药

Objective: To investigate the application characteristics of excipient copovidone in co-grinding process and the feasibility of co-grinding products for improving the dissolution of curcumin, using curcumin as a model drug in vitro. Methods: The prepared products were obtained by curcumin and various proportions (0%, 1%, 3%) of copovidone in co-grinding process, which were characterized by laser particle size analyzer, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and X-ray powder diffraction (XRPD). The in vitro dissolution of milled products was evaluated in two media, and their accelerated stability was investigated. Results: In comparison with pure curcumin, the particle size of milled products decreased with the lower crystallinity by XRPD analysis, but the hygroscopicity and DSC thermograms showed no significant difference. Moreover, compared with pure curcumin, the products exhibited significant improvement of in vitro dissolution. Also, there was no significant difference in the dissolution behavior of products placed under the accelerated conditions (40 ℃, RH 75%) for three months, indicating their good stability. Conclusion: As a new excipient, copovidone could effectively enhance the dissolution of curcumin via co- grinding process. This study provided a feasible strategy for improving the solubility and even oral bioavailability of poorly soluble drugs.

Primary pulmonary diffused large B-cell lymphoma with multiple ground glass nodule shadows in lungs as main manifestation: A case report and literature review / 吉林大学学报(医学版)

Objective: To analyze the clinical features∗ imaging findings, diagnostic methods, pathomorphology and prognosis of the patients with primary pulmonary diffused large B-cell lymphoma (DLBCL) with the multiple ground glassy nodule shadows in the lungs as the main manifestation, and to improve the clinicians' understanding of the primary pulmonary DLBCL. Methods: The clinical data of a patient with primary pulmonary DLBCL were collected. The main manifestation in CT examination of the patient was multiple massive ground glass nodule shadows in the lungs. The initial diagnosis was pneumonia. The final diagnosis of primary pulmonary DLBCL was confirmed by pathology and immunohistochemistry examination. The related literatures were reviewed. Results: The female patient was admitted to hospital due to cough and expectoration as the first manifestations. There were no obvious positive signs in the physical examination. The CT examination results showed multiple ground glassy nodular shadows in both lungs. The tumor markers∗ lymph node color Doppler ultrasound, PET-CT∗ bone marrow biopsy∗ pathological biopsy and the other related examinations were performed∗ and the related treatment were given. The PET-CT results showed the multiple ground glass nodule in both lungs complicated with increasing of partial metabolism∗ and the pathological and immunohistochemical results suggested that the patient was non-Hodgkin DLBCL originated from the activated B cells outside the germinal center, and the final diagnosis was primary pulmonary DLBCL. The patient was given R CHOP regimen regularly. The patient received chest CT examination 3 months later, and the results showed that the massive nodule shadows in both lungs were disappeared. Conclusion: The clinical features and imaging findings of the patient with primary pulmonary DLBCL are not specific, its diagnosis ultimately relies on the pat homo pho logical and immunohistochemical examination results; the degree of malignancy of primary pulmonary DLBCL is high, and the prognosis is poor; when there are multiple ground glass nodule shadows in the lungs, the disease should be taken into account.

Descripción de la prueba semiológica de Compresión y flexión del pulgar, para el diagnóstico de Rizartrosis. Estudio de Cohorte Transversal / Description of thumb compression and flexion test for the diagnosis of rhizarthrosis. Cross sectional Cohort Study

Introducción El dolor del pulgar secundario a la artrosis de la articulación trapecio-metacarpiana es una condición común, especialmente en mujeres llegando a causar niveles altos de incapacidad en algunos pacientes. El diagnóstico de rizartrosis se basa en el dolor localizado, la inflamación e inestabilidad en la exploración física además de la valoración radiológica. Existen en la actualidad varias pruebas semiológicas que podemos utilizar en el diagnóstico de la rizartrosis sintomática, una de ellas es la prueba de Grind o molienda, que es considerada el patrón de oro. El presente estudio tiene como objetivo describir y evaluar la prueba de Compresión y flexión del pulgar ideada para el diagnóstico de rizartrosis. Materiales y Métodos Se realizó un estudio de corte transversal en el periodo de enero del 2007 a mayo del 2013, Se evaluaron 230 pacientes que acudieron a consulta con síntomas sugestivos de rizartrosis a quienes se les practico simultáneamente la prueba de Grind y la prueba de compresión y flexión para la confirmación del diagnóstico. Resultados De los 230 pacientes que acudieron a consulta, el 87.8% (202) eran mujeres con una edad promedio de 60 años (32 a 86 años). El 14.8% de los pacientes presentaron una afectación bilateral. El 47.8% tenían comorbilidades presentes entre las que se encuentran síndrome de túnel carpiano en el 67.3%, dedo en gatillo 11.8%, entre otras. El índice de concordancia PABAK entre los dos signos semiológicos fue de 0.948, indicando un nivel de acuerdo excelente entre ambos. El 100% de los pacientes fueron diagnosticados por la prueba de flexión y compresión. Discusión producto de obtener una prueba positiva en la totalidad de los pacientes evaluados con la prueba de compresión y flexión, consideramos puede ser una opción que complemente la pesquisa clínica en el paciente con rizartrosis, es necesario entonces estudios posteriores para validar dicha prueba y poder obtener su sensibilidad y especificidad.

Background Thumb pain secondary to osteoarthritis of the trapezium-metacarpal joint is a common condition, especially in women, and causing high levels of disability in some patients. The diagnosis of rhizarthrosis is based on localised pain, inflammation, and instability on physical examination, in addition to radiographic evaluation. There are currently several semiological tests that can be used in the diagnosis of symptomatic rhizarthrosis, one of which is the Grind or grinding test, which is considered the gold standard. The present study aims to describe and evaluate the thumb compression and flexion test designed for the diagnosis of rhizarthrosis. Methods A cross-sectional study was carried out during the period from January 2007 to May 2013. The study included a total of 230 patients that came to the clinic with symptoms suggestive of rhizarthrosis, and on whom the Grind test, the compression test, and flexion were simultaneously performed to confirm the diagnosis. Results Of the 230 patients who attended the clinic, 87.8% (202) were women with a mean age of 60 years (32 to 86 years). A bilateral involvement was observed in 14.8% of the patients. Just under half (47.8%) currently had co-morbidities that included, among others, carpal tunnel syndrome (67.3%) and trigger finger (11.8%). The prevalence-adjusted and bias-adjusted kappa (PABAK) concordance index between the two semiological signs was 0.948, indicating an excellent level of agreement between both. All (100%) of the patients were diagnosed by the flexion and compression test. Discussion Due to obtaining a positive test in all the patients evaluated with the compression and flexion test, it should be considered as a complementary test in the clinical evaluation of patients with rhizarthrosis. Further studies are necessary to validate this test in order to establish its sensitivity and specificity.

Comparison of the accuracy of three methods for determining maxillomandibular horizontal relationship of the complete denture / 华西口腔医学杂志

OBJECTIVE@#To observe the changes of forward displacement of maxillary complete denture during centric occlusion, three different methods were used to record the changes of vertical overlap and the comfort level of patients before and after the selective grinding of the three dentures made according to maxillo-mandibular horizontal relationship record.@*METHODS@#Twelve edentulous patients with normal stomatognathic system were recruited in this study. Three types of complete dentures for these 12 edentulous patients were made according to their different maxilla-mandibular horizontal relationship record methods. The amount of displacement of the maxillary complete denture, the vertical overlap of the anterior teeth as well as patient comfort level were recorded before and after selective grinding. Statistical analysis was performed using the SPSS 17.0 software package.@*RESULTS@#Before selective grinding, the amount of displacement of denture A was significantly larger than those of dentures B and C (P0.05). During selective grinding, the vertical overlap variation of denture A was significantly greater than those of dentures B and C (P0.05). After selective grinding, no statistical difference was found among the three dentures (P>0.05).@*CONCLUSIONS@#Among the complete dentures with anatomical teeth, the dentures whose horizontal relationship was recorded at 1 mm before the apex of the Gothic arch apex and with checkbite are more in line with clinical repair requirements. Complete dentures whose horizontal relationship was recorded at the apex of Gothic arch need to be adjusted with selective grinding to meet the clinical restoration requirements.

Evaluating the occupational exposure to hand-transmitted vibration in golf ball head grinding positions / 中国职业医学

OBJECTIVE: To evaluate the exposure status of hand-transmitted vibration(HTV)in golf ball head grinding workers.METHODS: The golf ball head grinding positions in a sports equipment factory were selected as the research subjects by the judgement sampling method.The HTV exposure level of the workers in 66 grinding positions was measured,the key control points for HTV hazards were identified,and the damage of HTV was classified.RESULTS: The median(M)of 4 hours energy equivalent frequency-weighted acceleration to vibration[a_(hw(4))]of grinding positions in this sports equipment factory was 4.21 m/s~2,and the a_(hw(4)) over standard rate was 50.0%(33/66).The a_(hw(4)) of rough grinding positions was higher than that of fine grinding positions(M:5.50 v.s 3.94 m/s~2,P<0.05).In both rough grinding positions and fine grinding positions,the a_(hw(4)) of different ball head grinding types from high to low were hollow titanium alloy ball heads, hollow stainless steel ball heads,and solid stainless steel ball heads(rough grinding positions M:7.41 vs4.43 vs 3.11 m/s~2,P<0.01; fine grinding p ositions M:5.24 vs 4.21 vs 2.93 m/s~2,P<0.01).For the hollow titanium alloy ball head grinding positions,the a_(hw(4)) of rough grinding was higher than that of fine grinding(M:7.47 vs 5.24 m/s~2,P<0.01).Rough grinding positions,especially hollow stainless steel ball heads and hollow titanium alloy ball head grinding positions were key control points for HTV hazards.In the 66 grinding positions,the HTV hazards were classified as grade 0,Ⅰ,Ⅱ,and Ⅲ in the grinding positions accounted for 3.0%,47.0%,40.9%,and 9.1%,respectively,and those with grade Ⅱ and above were 50.0%(33/66). CONCLUSION: The exposure level of HTV in golf ball head grinding workers is high,with a trend of exceeding the standard.The golf ball head grinding workers have a high occupational health risk.

Effects of Superfine Grinding Technology on Powder Properties and Dissolution of Oyster Shell / 中国药房

OBJECTIVE： To study the effects of superfine grinding on the powder properties and dissolution of oyster shell， and to provide experimental basis for its comprehensive exploitation. METHODS： Oyster shells were firstly prepared into ordinary powder by grinder. Then the ordinary powder was prepared into micro-powder Ⅰ （crushing 5 min） and Ⅱ （crushing 10 min） by ultrafine pulverizer. The differences of micromeritic properties were investigated before and after superfine grinding from the aspects of particle size distribution， specific surface area and porosity， angle of repose， bulk density， hygroscopicity， etc. Scanning electron microscope （SEM）， Fourier transform infrared spectroscopy （FTIR） and X-ray powder diffraction （XRD） techniques were used to analyze the morphological characteristics and chemical structure of oyster shell before and after superfine grinding. The dissolution were investigated. RESULTS： Compared with ordinary powder， micropowder Ⅰ and micropowder Ⅱ’s were small in particle size and uniformly distributed， but the particles were easy to adhere and aggregate； the specific surface area， porosity and the angle of repose increased， while bulk density decreased； the hygroscopicity increased. FTIR and XRD showed no significant change in chemical structure of oyster shell after superfine grinding. The dissolution rate of micropowder Ⅱ and micropowder Ⅰ was 18.5％ and 10.3％ at 10 min， and the dissolution of ordinary powder was only 6.4％ at 60 min. CONCLUSIONS： Compared with ordinary powder， oyster shell show obvious differences in powder properties after superfine grinding； the dissolution rate of the powders increases， and there is no significant change in chemical structure.

Research progress on superfine grinding technique in field of Chinese materia medica / 中草药

With the continuous development of the modernization of Chinese materia medica (CMM), the superfine grinding technology has been continuously applied to the basic and applied research of raw materials and preparations, which has become an important way to improve and enhance the quality of traditional Chinese medicine decoction pieces and traditional preparations. This paper introduces the concept, the equipment, working principle and characteristics of superfine grinding, and expounds the general situation of application of superfine grinding technology in Chinese materia medica (CMM). The prospective application of superfine grinding technology in the field of CMM was analyzed and prospected. The problems that should be paid attention to in the future research and application of superfine grinding of CMM were put forward.

Improving hygroscopicity of fermented Cordyceps powder based on particle design technology of traditional Chinese medicine / 中国中药杂志

Commonly used dosage forms of fermented Cordyceps powder products are capsules and tablets. The hygroscopicity of the powder,as one of the important parameters in the tableting process,has important effects on the tabletting process of the tablets. How to improve the hygroscopicity of powder is of great significance for the development of new composite particles. Therefore,particle design technology was used in this study to prepare composite particle powder,and its hygroscopicity was compared with fermented Cordyceps powder and physically mixed powder. By preparing three different types of powders,the equilibrium moisture absorption,particle size,scanning electron micrograph,angle of repose,contact angle and compression degree were compared to observe the effect of traditional Chinese medicine particle design technology on improving the hygroscopicity of the fermented Cordyceps powder. The results showed that the equilibrium moisture absorption was 21. 2%,19. 6%,14. 5% respectively for the fermented Cordyceps powder,physically mixed powder and composite particle powder; the median diameter was(49. 751± 0. 280),(59. 183± 0. 170),(12. 842±0. 080) μm,respectively; the mode diameter was(185. 479±1. 372),(173. 964± 1. 104),(61. 671± 0. 979) μm,respectively. In the scanning electron micrograph of the composite particle powder,it can be clearly seen that the fermented Cordyceps powder had hydrophobic gas phase nano-silica with a fixed shape and uniform size. The angle of repose was(50. 63 ± 0. 75) °,(49. 25 ± 0. 43) °,(48. 33±0. 84) ° respectively; the contact angle was(7. 4±0. 2) °,(8. 2±0. 3) °,(15. 0±2. 6) ° respectively; and the compression degree was(38. 2±1. 3) %,(35. 8±0. 2) %,(32. 5±2. 6) % respectively. This study showed that after treatment by the vibrating ultrafine pulverizer,the fermented Cordyceps powder particles had obvious and uniform small particle hydrophobic gas phase nano-silica adhered to form a partially wrapped coating structure,which reduced the contact surface of fermented Cordyceps powder with the outside world,thereby reducing the hygroscopicity of the composite particle powder. It further demonstrated that the hygroscopicity of fermented Cordyceps powder can be improved by particle design.

Micronization and extrusion processing on the physicochemical properties of dietary fiber / Efeito dos processos de micronização e extrusão nas propriedades físico-químicas da fibra alimentar

ABSTRACT: Dietary fiber plays an important physiological role, which is directly linked to its physicochemical properties, water-holding, oil-binding, and cation-exchange capacities. These properties can be altered by employing enzymatic, mechanical, and physical processes. Enzymatic and chemical processes require solvents and special conditions that make it unfeasible to use. Thus, the use of physical methods, such as micronization and extrusion, make promising options to change the physicochemical properties of dietary fiber. In this way, this review aimed to approach relevant information about the use of physical processes, specifically micronization and extrusion, for this purpose. Furthermore, conceptual aspects, such as definition, classification, and properties of dietary fiber and mainly characteristics about the micronization and extrusion processes, are reported. Micronization and extrusion are based on the decrease of the particle size to a micro scale and on the combination of high temperature, mechanical shearing and pressure, respectively. Applying these methods, modifications on the food matrix occurred by increasing the surface area and disruption of the glycosidic bonds. Consequently, there is a change in physicochemical properties of dietary fiber, which predict the physiological effect associated with dietary fiber consumption, such as decrease in blood cholesterol and glucose levels and improvement of intestinal transit. Moreover, these changes increase the bio accessibility of bioactive compounds present in the food matrix and improve the antioxidant capacity of products.

RESUMO: A fibra alimentar desempenha importante papel fisiológico, o qual está diretamente ligado às suas propriedades físico-químicas de capacidade de retenção de água, ligação ao óleo e a cátions. Estas propriedades podem ser alteradas empregando-se métodos enzimáticos, químicos e físicos. Métodos enzimáticos e químicos requerem solventes e condições específicas que inviabilizam sua utilização. Assim, o emprego dos métodos físicos, tais como micronização e extrusão, tornam-se alternativas promissoras para alterar as propriedades físico-químicas da fibra alimentar. Desta forma, este trabalho visa abordar informações relevantes sobre o uso dos processos físicos, especificamente micronização e extrusão para essa finalidade. Além disso, aspectos conceituais como definição, classificação e propriedades da fibra alimentar e as principais características dos processos de micronização e extrusão são relatados. Micronização e extrusão baseiam-se na diminuição do tamanho de partícula para microescala e na combinação de alta temperatura, pressão e força de cisalhamento, respectivamente. Aplicando-se estes métodos, modificações na matriz alimentícia ocorrem pelo aumento da área superficial e rompimento das ligações glicosídicas da matriz alimentar. Consequentemente, são observadas alterações nas propriedades físico-químicas da fibra alimentar, as quais predizem o efeito fisiológico associado ao seu consumo, como diminuição dos níveis de colesterol e glicose sanguíneos e a melhora do trânsito intestinal. Ademais, essas alterações aumentam a bioacessibilidade dos compostos bioativos presentes na matéria-prima alimentícia e melhoram a capacidade antioxidante dos produtos obtidos.

Polishing of ground y-tzp ceramic is mandatory for improving the mechanical behavior

Abstract It evaluated the effect of aging by Low Temperature Degradation (LTD), executed after post- processing surface treatments (polishing, heat treatment and glazing), on the surface characteristics (micromorphology and roughness) and on the structural stability (phase transformation and mechanical behavior-flexural strength and structural reliability) of a ground yttrium-stabilized tetragonal zirconia polycrystal (Y-TZP) ceramic. Discs of Y-TZP (VITA In-Ceram YZ) were manufactured (ISO:6872-2015; 15 mm in diameter and 1.2 ± 0.2 mm in thickness) and randomly assigned into 10 groups according two factors: "aging" in 2 levels (with or without) and "surface treatment" in 5 levels (Ctrl: as-sintered; Gr: grinding with coarse diamond bur; Gr + HT: grinding plus heat treatment; Gr + Pol: grinding plus polishing; Gr + Gl: grinding plus glazing). Roughness (n=30), biaxial flexural test (n=30), phase transformation (n=2), and surface topography (n=2) analyses were performed. Aging led to an intense increase in monoclinic (m) phase content for all the tested conditions, being the as-sintered samples (Ctrl= 65.6%) more susceptible to the t-m phase transformation. Despite of increasing the m-phase content, aging was not detrimental for characteristic strength (except to the grinding condition). There was no significant reduction in the Weibull modulus after surface treatments. Additionally, heat treatment and glazing after grinding led to a decrease in characteristic strength, while polishing presented the highest characteristic strength values. Thus, polishing is mandatory after grinding the Y-TZP ceramic, while performing glazing or heat-treatment alone after grinding lead to the worst mechanical performance.

Resumo Este estudo avaliou o efeito do envelhecimento através da degradação a baixas temperaturas (low temperaturare degradation - LTD) após a realização de tratamentos de superfície pós- sinterização (polimento, tratamento térmico e glaze) nas características superficiais (micromorfologia e rugosidade), e na estabilidade estrutural (transformação de fase e comportamento mecânico - resistência flexural e confiabilidade estrutural) de uma cerâmica de zircônia tetragonal policristalina estabilizada por ítria (Y-TZP) desgastada. Discos de cerâmica Y-TZP (VITA In-Ceram YZ) foram confeccionados (ISO:6872-2015; 15mm de diâmetro e 1,2 ± 0,2mm de espessura) e randomicamente divididos em 10 grupos de acordo com dois fatores: "envelhecimento" (com e sem) e "tratamento de superfície" (Ctrl - sem tratamento; Gr - desgaste com ponta diamantada grossa; Gr + HT - desgaste mais tratamento térmico; Gr + Pol - desgaste mais polimento; Gr + Gl - desgaste mais glazeamento). Foram realizadas as análises de rugosidade (n=30), flexão biaxial (n=30), transformação de fase (n=2) e topografia de superfície (n=2). O envelhecimento levou a um aumento intenso no conteúdo de fase monoclínica (m) em todas as condições testadas, sendo observada uma maior susceptibilidade de transformação de fase t-m nas amostras do grupo controle (Ctrl= 65.6%). Apesar de provocar elevada transformação de fase, o envelhecimento não apresentou efeitos negativos nos desfechos avaliados. Não houve redução significativa do módulo de Weibull após os tratamentos. Além disso, o tratamento térmico e o glaze após desgaste levaram a uma redução da resistência característica, enquanto que o grupo polimento apresentou o mais alto valor de resistência característica. O glaze e o tratamento térmico geraram o pior desempenho mecânico, portanto a realização do polimento após desgaste de uma cerâmica Y-TZP é obrigatória.

Apnea/hipopnea del sueño y bruxismo nocturno / Sleep apnea/hypopnea and night bruxism

Los eventos de apnea o hipopnea durante el proceso del sueño se caracterizan por una disminución o bloqueo de la respiración induciendo a un estado orgánico de hipooxigenación que a su vez induce a microdespertares en reacción fi siológica de protección del organismo. Durante estos eventos, el individuo transita de una fase profunda del sueño a una más superfi cial. La repetición de los eventos de apnea/hipopnea provoca que el sueño no sea reparador física y emocionalmente, además de provocar una hiperactividad motora de los músculos masticadores. induciendo un incremento en la frecuencia e intensidad de movimientos rítmicos masticatorios que eventualmente pueden promover daños musculares, articulares, mucosos y dentales. El incremento de los movimientos rítmicos mandibulares también se observa en bruxismo nocturno, lo que abre la posibilidad que haya un efecto sumatorio entre ellos. Para ambos tipos de padecimientos, la polisomnografía empleada en tiempos modernos es un procedimiento para evaluar las alteraciones del sueño, que puede demostrar que los microdespertares preceden a un incremento de manifestaciones del sistema nervioso autónomo, incluida la hiperactividad muscular, la cual puede provocar alteraciones orgánicas de tipo sistémico, además de episodios de apretamiento y rechinamiento dental (AU)

The events of apnea or hypopnea during the sleep process are characterized by a decrease or obstruction of respiration inducing an organic state of hypooxygenation that in turn induces micro-arousals as a physiological reaction to protect the organism. During these events, the individual transits from a deep sleep phase to a more superfi cial phase. The repetition of apnea/hypopnea events causes a sleep that is nor physically neither emotionally repairing; furthermore inducing a motor hyperactivity of the masticatory muscles which increases the frequency and intensity of rhythmic masticatory movements that can eventually promote muscular, joint (TMJ), mucous and dental damage. That increase of the rhythmic masticatory movements is also observed in sleep bruxism, which leaves open the possibility of observing a summation eff ect with sleep apnea. For this type of conditions, polysomnography is a procedure that assesses sleep disturbances and demonstrates that micro-arousal precedes an increase autonomic changes, including muscle hyperactivity, which eventually could cause organic systemic alterations, as well episodes of clenching and dental grinding (AU)

Effect of Grinding and Multi-Stimuli Aging on the Fatigue Strength of a Y-TZP Ceramic

Abstract This study aimed to investigate the effect of grinding and multi-stimuli aging on the fatigue strength, surface topography and the phase transformation of Y-TZP ceramic. Discs were manufactured according to ISO-6872:2008 for biaxial flexure testing (diameter: 15 mm; thickness: 1.2 mm) and randomly assigned considering two factors "grinding" and "aging": C- control (as-sintered); CA- control + aging; G- ground; GA- ground + aging. Grinding was carried out with coarse diamond burs under water-cooling. Aging protocols consisted of: autoclave (134°C, 2 bars pressure, 20 hours), followed by storage for 365 days (samples were kept untouched at room temperature), and by mechanical cycling (106 cycles by 20 Hz under a load of 50% from the biaxial flexure monotonic tests). Flexural fatigue strengths (20,000 cycles; 6 Hz) were determined under sinusoidal cyclic loading using staircase approach. Additionally, surface topography analysis by FE-SEM and phase transformation analysis by X-ray Diffractometry were performed. Dixon and Mood methodology was used to analyze the fatigue strength data. Grinding promotes alterations of topographical pattern, while aging apparently did not alter it. Grinding triggered t-m phase transformation without impacting the fatigue strength of the Y-TZP ceramic; and aging promoted an intense t-m transformation that resulted in a toughening mechanism leading to higher fatigue strength for as-sintered condition, and a tendency of increase for ground condition (C < CA; G = GA). It concludes that grinding and aging procedures did not affect deleteriously the fatigue strength of the evaluated Y-TZP ceramic, although, it promotes surface topography alterations, except to aging, and t-m phase transformation.

Resumo Este estudo objetivou investigar o efeito do desgaste e envelhecimento (estímulos combinados) na resistência à fadiga, topografia superficial e transformação de fase de uma cerâmica Y-TZP. Discos para teste de flexão biaxial foram confeccionados segundo as normas da ISO-6872:2008 (15 mm Ø; 1,2 mm espessura) e randomicamente distribuídos de acordo com os fatores "desgaste" e "envelhecimento": C- controle (sinterizado); CA- controle envelhecido; G- desgaste; GA- desgaste envelhecido. O desgaste foi feito com pontas diamantadas de granulação grossa sob irrigação com água. Os protocolos de envelhecimento consistiram em: autoclave (134°C, 2 bar de pressão, 20 horas), 365 dias armazenados em temperatura ambiente, e ciclagem mecânica (106 ciclos a 20 Hz em um intervalo de carga de até 50% da carga monotônica observada em testes estáticos). A resistência à fadiga foi determinada para 20.000 ciclos à 6 Hz sob carregamento sinusoidal através do método de escada. Adicionalmente, análises de topografia superficial em microscopia eletrônica de varredura e de transformação de fase por difração de raios-X foram executadas. A metodologia de Dixon e Mood foi usada para analisar os dados de resistência à fadiga. Foi observado que o desgaste promove uma alteração de padrão topográfico superficial; enquanto o envelhecimento aparentemente não demonstra influência. Em relação à transformação de fase e resistência à fadiga, o desgaste desencadeou um aumento de fase m sem impactar na resistência à fadiga da cerâmica Y-TZP; já o envelhecimento promoveu uma intensa transformação de fase, resultando no mecanismo de tenacificação, que gerou um aumento na resistência à fadiga para a condição sinterizada e uma tendência a aumento na condição desgaste (C < CA; G = GA). Os dados elucidam que o desgaste e o envelhecimento não impactaram negativamente na resistência à fadiga da cerâmica Y-TZP, apesar de promoverem alterações de topografia superficial e intensa transformação de fase de t-m respectivamente.