Occupational radiation exposure in anesthesia for hepatic chemoembolization: a prospective study

Introduction Anesthetists play an important role during interventional radiology procedures. Like the main operator, anesthetists may also be subject to significant radiation levels in the fluoroscopy suite. Due to its complexity, hepatic chemoembolization procedures demand high fluoroscopic times and digital subtraction angiography images, exposing patients and medical staff to high radiation doses. Objective To assess and quantify the radiation to which one anesthetist was exposed over the course of seven consecutive hepatic chemoembolization procedures, and compare it to the exposure received by the main operator. Methods Medical staff dosimetry was evaluated during seven consecutive hepatic chemoembolization procedures conducted in a private hospital in Recife (Brazil), using thermoluminiscent dosimeters placed in regions of the head and torso. Results For the seven procedures evaluated in this study, the anesthetist received, on average, absorbed doses to the glabella, left eyebrow, right eyebrow and effective dose of 142.4 ± 72 µSv, 117.3 ± 66 µSv, 137.8 ± 71 µSv and 12.4 ± 8.4 µSv, respectively. Conclusions In some cases, ocular dose and effective dose received by the anesthetist may be 4 and 4.7 times greater, respectively, when compared to the main operator. According to the results of this study, the current occupational annual dose limit to the lens of the eye of 20 mSv can be exceeded with only two hepatic chemoembolization procedures per week if adequate radiation protection conditions are not guaranteed.

Introducción El anestesiólogo desempeña un papel importante durante los procedimientos de radiología intervencionista. Al igual que el operador principal, el anestesiólogo también puede estar expuesto a niveles significativos de radiación en la sala de fluoroscopía. Debido a su complejidad, durante los procedimientos de quimioembolización hepática se deben utilizar imágenes de fluoroscopía y angiografía de sustracción digital por períodos prolongados, exponiendo a los pacientes y al personal médico a dosis elevadas de radiación. Objetivo Evaluar y cuantificar la radiación a la cual se expuso un anestesiólogo durante el transcurso de siete procedimientos consecutivos de quimioembolización hepática, y comparar con la exposición recibida por el operador principal. Métodos Evaluación de la dosimetría ocupacional durante siete procedimientos consecutivos de quimioembolización hepática realizados en un hospital privado de Recife (Brasil) por medio de dosímetros termoluminiscentes ubicados en regiones de la cabeza y el torso. Resultados Para los siete procedimientos evaluados en este estudio, el anestesiólogo recibió, en promedio, dosis absorbidas en el entrecejo, la ceja izquierda, la ceja derecha y dosis efectivas de 142,4 ± 72 µSv, 117,3 ± 66 µSv, 137,8 ± 71 µSv y 12,4 ± 8,4 µSv, respectivamente. Conclusiones En algunos casos, la dosis ocular y la dosis efectiva que recibe el anestesiólogo puede ser, respectivamente, entre 4 y 4,7 veces más alta que la que recibe el operador principal. De acuerdo con los resultados de este estudio, el límite ocupacional anual de dosis en cristalino (20 mSv) se puede superar con apenas dos procedimientos de quimioembolización hepática a la semana en caso de no garantizarse las condiciones adecuadas de protección contra la radiación.

Evaluación de las características nutricionales de alimentos y bebidas procesados publicitados en medios televisivos de Perú, 2021

El objetivo fue describir las características y el perfil nutricional de los alimentos y bebidas procesados publicitados durante el horario de protección al menor (6 am a 10 pm, según la regulación peruana) los dos canales de mayor audiencia de la televisión peruana. En este estudio transversal se grabaron 448 horas de contenido televisivo de 14 días aleatorios de 6:00 am a 10:00 pm, entre enero y febrero del 2021, donde se identificaron 2061 anuncios de alimentos y bebidas procesados. Entre 2:00 pm y 6:00 pm (33,9%) hubo mayor publicidad de alimentos. Las categorías más publicitadas fueron bebidas (41,7%) y confitería (17,8%). El 46,9% de alimentos superó al menos uno de los parámetros técnicos (azúcar total, grasas saturadas o sodio) de la primera etapa de la ley peruana y el 88,4% lo haría en la segunda etapa. La mayoría de alimentos y bebidas publicitados fueron procesados y superaban los parámetros de nutrientes críticos.

The objective was to describe the characteristics and nutritional profile of processed foods and beverages advertised during child protection hours (6 am to 10 pm, according to Peruvian regulations) on the two channels with the largest audience on Peruvian television. In this cross-sectional study, 448 hours of television content on 14 random days from 6:00 am to 10:00 pm between January and February 2021 were recorded and 2061 advertisements for processed foods and beverages were identified. The time frame with the most publicity for these foods was between 2:00 pm. and 6:00 pm. (33,9%). The most advertised categories were beverages (41,7%) and confectionery (17,8%). 46,9% of foods exceeded at least one of the technical parameters evaluated in the first stage of the Peruvian law (total sugar, saturated fat, or sodium) and 88,4% would do so in the second stage. The majority of advertised foods and beverages were processed, and most of these exceed critical nutrient parameters.

La laserfluorescencia cualitativa en el diagnóstico del límite cavitario

Introducción: La fluorescencia inducida por láser es capaz de discernir entre tejido sano o enfermo y ha sido aplicada a distintos ámbitos dentro de la Odontología. Sin embargo, la laserfluorescencia cualitativa ha sido poco estudiada para determinar el límite cavitario. Objetivo: Evaluar la efectividad y seguridad del uso de la laser-fluorescencia, a λ=450 nm y 405 nm, en la detección del límite cavitario. Método: Se seleccionaron 45 dientes ex-vivo, que presentaban al menos una localización de caries dentinaria. Se determinaron 83 áreas para el estudio en las que se midió la fluorescencia mediante tres sistemas con diferentes longitudes de onda (405-450 nm). Se calculó la seguridad de la prueba con las categorías de color recomendadas por el fabricante y una escala resultado de la recodificación de las variables. Mediante el software Pilxelmator MAC se convirtieron las variables RGB del color en valores cuantitativos de la escala CIE. Los datos fueron introducidos en el programa estadístico SPSS 19.0. Se aplicaron pruebas de significación (α≤0,05). Resultados: Las categorías de color recomendadas por el fabricante no coinciden con las escalas que muestran la mejor sensibilidad y especificidad. La laserfluorescencia (405 nm-450 nm) es más específica que sensible. Las variables L*a*b son capaces de diferenciar entre dentina recuperable y no recuperable y la LIF-405 nm discrimina entre las capas que delimitan el límite cavitario. Conclusiones: La fluorescencia inducida por láser es un método útil para el diagnóstico del límite cavitario, si bien las recomendaciones del fabricante deben ser modificadas. El sistema L*a*b puede contribuir a eliminar la subjetividad del operador.

Introduction: Laser-induced fluorescence is capable of discerning between healthy and diseased tissue and has been applied to different areas within Dentistry. However, qualitative laserfluorescence has been little studied to determine the cavity limit. Objective: To evaluate the effectiveness and safety of the use of laser fluorescence, at λ=450 nm and 405 nm, in detecting the cavity limit. Method: 45 teeth were selected ex-vivo, which presented at least one location of dentin caries. 83 areas were determined for the study in which fluorescence was measured using three systems with different wavelengths (405-450 nm). The safety of the test was calculated with the color categories recommended by the manufacturer and a scale resulting from the recoding of the variables. Using the Pilxelmator MAC software, the RGB color variables were converted into quantitative values of the CIE scale. The data were entered into the SPSS 19.0 statistical program. Significance tests were applied (α≤0.05). Results: The color categories recommended by the manufacturer do not match the scales that show the best sensitivity and specificity. Laserfluorescence (405 nm-450 nm) is more specific than sensitive. The L*a*b variables are capable of differentiating between recoverable and non-recoverable dentin and the LIF-405 nm discriminates between the layers that delimit the cavity boundary. Conclusions: Laser-induced fluorescence is a useful method for diagnosing the cavity limit, although the manufacturer's recommendations must be modified. The L*a*b system can help eliminate operator subjectivity.

Introdução: A fluorescência induzida por laser é capaz de discernir entre tecido saudável e doente e tem sido aplicada em diversas áreas da Odontologia. Entretanto, a laserfluorescência qualitativa tem sido pouco estudada para determinar o limite da cavidade. Objetivo: Avaliar a eficácia e segurança do uso da fluorescência do laser, em λ=450 nm e 405 nm, na detecção do limite da cavidade. Método: Foram selecionados 45 dentes ex-vivo, que apresentavam pelo menos uma localização de cárie dentinária. Foram determinadas 83 áreas para o estudo nas quais a fluorescência foi medida usando três sistemas com diferentes comprimentos de onda (405-450 nm). A segurança do teste foi calculada com as categorias de cores recomendadas pelo fabricante e uma escala resultante da recodificação das variáveis. Utilizando o software Pilxelmator MAC, as variáveis de cores RGB foram convertidas em valores quantitativos da escala CIE. Os dados foram digitados no programa estatístico SPSS 19.0. Foram aplicados testes de significância (α≤0,05). Resultados: As categorias de cores recomendadas pelo fabricante não correspondem às escalas que apresentam melhor sensibilidade e especificidade. A laserfluorescência (405 nm - 450 nm) é mais específica do que sensível. As variáveis L*a*b são capazes de diferenciar entre dentina recuperável e não recuperável e o LIF-405 nm discrimina entre as camadas que delimitam o limite da cavidade. Conclusões: A fluorescência induzida por laser é um método útil para diagnosticar o limite da cavidade, embora as recomendações do fabricante devam ser modificadas. O sistema L*a*b pode ajudar a eliminar a subjetividade do operador.

Regulação de resíduos de agrotóxicos em alimentos no MERCOSUL: discussão necessária para vigilância sanitária / Regulation of pesticide residues in food in the MERCOSUR: a much needed discussion for health surveillance / Regulación de los residuos de productos agrotóxicos en los alimentos en el MERCOSUR: una discusión necesaria para la vigilancia de la salud

RESUMO O objetivo deste estudo descritivo e exploratório, de base qualitativa, foi identificar as resoluções do MERCOSUL sobre resíduos de agrotóxicos em alimentos publicadas entre 1991 e 2022, analisando os processos de harmonização regional desses marcos e sua incorporação ao arcabouço regulatório dos Estados Partes fundadores do bloco (Argentina, Brasil, Paraguai e Uruguai). A análise identificou pontos importantes para a regulação e o monitoramento de resíduos de agrotóxicos em alimentos no MERCOSUL, como as sinonímias utilizadas na definição de agrotóxicos e a abrangência do sistema regulatório de cada país, as marcadas diferenças no alcance dos principais marcos regulatórios nacionais, a incorporação desigual de regulamentos internacionais e regionais pelos Estados Partes e os desafios para a harmonização da legislação sobre resíduos de agrotóxicos em alimentos no âmbito do MERCOSUL. Para além dos limitados avanços observados na tentativa de harmonizar a legislação pertinente dentro do bloco, observa-se a necessidade de avançar, nacional e regionalmente, nos processos regulatórios sobre resíduos de agrotóxicos em alimentos, garantindo a qualidade dos produtos e serviços ofertados à população e fortalecendo, assim, um comércio de alimentos mais seguros e produzidos a partir de processos menos prejudiciais ao ambiente no MERCOSUL.

ABSTRACT The objective of this descriptive and exploratory study with a qualitative basis was to identify MERCOSUR resolutions on pesticide residues in food issued between 1991 and 2022, analyzing the regional harmonization processes of these milestones and their incorporation into the regulatory framework of MERCOSUR founding Member States (Argentina, Brazil, Paraguay, and Uruguay). The analysis identified important points for the regulation and monitoring of pesticide residues in food in MERCOSUR, such as the synonyms used in the definition of pesticides and the scope of the regulatory system in each country, the marked differences in the scope of the main national regulatory frameworks, the unequal incorporation of international and regional regulations by the Member States and the challenges for harmonizing legislation on pesticide residues in food within MERCOSUR. In addition to the limited advances observed in the attempt to harmonize the relevant legislation within the bloc, there is a need to advance, nationally and regionally, in the processes to regulate pesticide residues in food, so as to ensure the quality of the products and services provided to the population and also to strengthen safer agro/food trade that relies on processes that are less harmful to the environment.

RESUMEN El objetivo de este estudio descriptivo y exploratorio, de base cualitativa, fue identificar las resoluciones del MERCOSUR sobre la gestión de residuos de productos agrotóxicos en los alimentos publicadas entre los años 1991 y 2022 y analizar los procesos de armonización regional de esos marcos y su incorporación al marco regulatorio de los Estados Partes fundadores del bloque (Argentina, Brasil, Paraguay y Uruguay). En el análisis se identificaron puntos importantes para la regulación y el seguimiento de la gestión de residuos de productos agrotóxicos en los alimentos en el MERCOSUR, tales como los sinónimos utilizados en la definición de productos agrotóxicos y la amplitud del sistema regulatorio de cada país, las diferencias más destacadas en el alcance de los principales marcos regulatorios nacionales, la desigualdad de la incorporación de los reglamentos regionales e internacionales por parte de los Estados Partes y los desafíos para la armonización de la legislación sobre residuos de productos agrotóxicos en los alimentos en el ámbito del MERCOSUR. Además de los limitados avances observados en el intento de armonizar la legislación pertinente dentro del bloque, existe la necesidad de avanzar, a nivel nacional y regional, en los procesos regulatorios sobre la gestión de residuos de productos agrotóxicos en los alimentos, asegurando la calidad de los productos y servicios ofrecidos a la población y fortaleciendo así el comercio de alimentos más inocuos producidos a partir de procesos menos nocivos para el medioambiente en el MERCOSUR.

Challenge of shielding design for FLASH radiotherapy / 中华放射医学与防护杂志

Compared with conventional radiotherapy, FLASH radiotherapy has advantages in protecting normal tissues, while the dose rate is increased by more than 100 times. If the shielding design of the treatment room is carried out according to the existing standard, the thickness and cost of the shielding wall will be significantly increased, or even hardly to meet the requirement of the standards, resultsing in the failure of the application of FLASH radiotherapy. By investigating the domestic and foreign standards and literature, this paper analyzes the challenges brought by FLASH radiotherapy technology to the shielding design of radiotherapy treatment room in China. Dose rate control standards adopted by different countries in the shielding design are emphatically compared as well. In several countries, the average dose rate under the actual treatment conditions was considered in the shielding design. In China, the method of instantaneous dose rate taking acount of occupancy factor is adopted. However, if FLASH radiotherapy technology is applied, the requirement of instantaneous dose rate will be difficult to meet. In order to improve the high dose rate radiotherapy technology such as FLASH radiotherapy, the revision of the existing standards is advised if the authorized limits are not changed. To use the average dose rate limit within a certain period of time for control, or to raise the control standard in the case of flash radiotherapy, are also avaliable.

Retrospective investigation on the normal range of serum alanine aminotransferase levels in healthy adults in Ningbo area / 中华传染病杂志

Objective:To reevaluate the upper limit of normal (ULN) of serum alanine aminotransferase (ALT) by retrospectively analyzing the ALT levels in healthy people in Ningbo area.Methods:A total of 56 140 people who underwent health examination and detection of liver biochemical indexes in the Affiliated Hospital of Medical School of Ningbo University and Yinzhou Huamao Hospital of Ningbo from 2018 to 2020 were enrolled. After excluding relevant factors that may lead to liver injury, 11 411 people were included to compare the difference of serum ALT levels among different genders and age groups (20 to 29 years, 30 to 39 years, 40 to 49 years and 50 to 59 years) to determine the ALT ULN in different gender groups. Statistical methods were performed using two independent samples t test and analysis of variance. Results:The serum ALT of males was (19.20±7.90) U/L, which was higher than that of females ((13.75±6.17) U/L), with statistical significance ( t=41.16, P<0.001). The serum ALT ULN in males and in females were 35 U/L and 26 U/L, respectively. The serum ALT levels of 20 to 29, 30 to 39, 40 to 49 and 50 to 59 years old groups were (15.48±7.61) U/L, (16.21±7.40) U/L, (17.36±7.52) U/L and (18.77±7.57) U/L, respectively.The difference was statistically significant ( F=71.51, P<0.001). Serum ALT level in 50 to 59 years old group was higher than that in 20 to 29 years old group, and the difference was statistically significant ( t=13.11, P<0.01). In males, the ALT ULN of 20 to 29 years old was the lowest of 34.43 U/L, and highest of 35.29 U/L in 40 to 49 years old. In females, the ALT ULN in the 20 to 29 years old group was the lowest of 23.01 U/L, and the ALT ULN in the 50 to 59 years old group was the highest of 30.79 U/L. ALT ULN increased with age in females. The serum ALT of males was higher than that of females in all age groups ( t=29.55, 26.91, 13.43 and 4.62, respectively, all P<0.05). Conclusions:The serum ALT level is significantly correlated to gender and age. The serum ALT ULNs of healthy adult are 35 U/L in males and 26 U/L in females in Ningbo area.

Rapid determination of microbial contamination of Bupleurum chinense DC. decoction slices by ATP bioluminescence technology combined with statistical analysis methods / 药学学报

This study focuses on the microbial quality control of the Chinese herbal decoction pieces. In view of the shortcomings of traditional culture methods such as slow detection speed and inability to detect unculturable microorganisms, a new method based on ATP bioluminescence technology combined with statistical analysis methods was established to rapidly predict and quantitatively detect the total aerobic microbial count (TAMC) and total yeast and mold count (TYMC) contaminated Bupleurum chinense DC. decoction pieces. Based on the optimized ATP bioluminesence detection system, accurate detection of pure bacterial solution of Escherichia coli, Bacillus subtilis and Staphylococcus aureus can be achieved, with detection limits of 47.86, 89.13 and 1 862.09 CFU·mL-1, respectively. The detection time was 6.5 h, and the detection cost was as low as 2 yuan/time. The upper and lower warning limits of TAMC were determined by the misjudgment rates of 10% and 20%, respectively. And the warning limit of TYMC was determined by the misjudgment rate of 20%. The proposed crossing method could quickly predict the amount of microbial contamination in Bupleurum chinense DC. decoction pieces. The constructed partial least squares regression (PLSR) model could accurately quantify the quantity of microbial contamination in Bupleurum chinense DC. decoction pieces. The optimal PLSR prediction model for TAMC had a correction coefficient (R2) of 0.826, a root mean square error of correction set (RMSEE) of 0.468 and a root mean square error of cross-validation set (RMSECV) of 0.465. The R2, RMSEE and RMSECV in the prediction model of TYMC were 0.778, 0.543 and 0.541, respectively. The aim of this study is to establish a kind of rapid detection method and prediction models for the microbial limit of traditional Chinese medicine and Chinese herbal decoction pieces, and to provide a more convenient and sensitive detection technology for the microbial quality process control of traditional Chinese medicine products.

Preparation of national reference panel of HBV for nucleic acid testing donor screening / 中国生物制品学杂志

@#Objective To prepare the national reference panel of hepatitis B virus(HBV) for nucleic acid testing(NAT)donor screening.Methods A number of plasma samples from donors positive for HBV antibody and patients with HBV infection collected from blood centers,plasma stations and biological products companies in Shanghai,Gansu,Henan,Hunan,Hubei and other regions were tested for HBV DNA viral load agent,and negative and positive reference candidates were screened;The HBV DNA national standard was diluted to 10~3 IU/ml with human negative plasma,as a candidate for limit of detection(LOD).National negative and positive reference candidates of HBV for NAT donor screening and LOD reference to be calibrated were distributed to 8 enterprise laboratories for joint detection of HBVHCVHIV NAT donor screening.The homogeneity and stability of the national reference panel were investigated.Results A total of 8 negative samples with HBV viral load of 0 were screened as negative references and 9 positive samples with viral load of 10~3～10~4 IU/mL were used as positive references;One LOD reference was calibrated with WHO HBV DNA standard,and the virus content was 1.0 × 10~3 IU/ml.The national reference panel showed good stability and the homogeneity inspection met the requirements.Conclusion The national reference panel of HBV DNA for NAT donor screening was prepared,which provided a basis for the quality control and standardization of HBV DNA reagents for donor screening.

Exploration on ALT threshold for initiating antiviral therapy in chronic HBV-infected patients based on results of 707 liver puncture cases / 中国热带医学

@#Abstract: Objective To explore the threshold of ALT for initiating antiviral therapy in HBV infected patients, and to provide a basis for initiating antiviral therapy in chronic HBV-infected patients. Methods This retrospective cohort study recruited 707 consecutive treatment-naïve chronic hepatitis B (CHB) patients undergoing diagnostic liver biopsy in the department of infectious diseases of the Affiliated Hospital of Yan′an University from October 2013 to August 2018. Liver biopsy specimens were obtained under ultrasound guidance using Menghini 16G disposable needles. The METAVIR scoring system, which is commonly used internationally, was used to divide the patients into the group with mild liver tissue injury and the group with significant liver tissue injury, and the alanine aminotransferase (ALT) levels were measured separately. Receiver operating characteristic (ROC) curve and Mann-Whitney U test were used to evaluate the diagnostic value of ALT for significant liver tissue injury under different demographic characteristics. Results Of 707 patients, 292 (41.30%) had significant liver tissue injury confirmed by liver biopsy (METAVIR ≥A2 and/or F2). When the ULN of ALT was set to NICE criteria (30 U/L for males, 19 U/L for females), AASLD criteria (35 U/L for males, 25 U/L for females) and EASL or APASL criteria (40 U/L for males and females), CHB patients with <ULN accounted for 32.38%, 35.03% and 36.07% of significant liver tissue injury, respectively. And significant liver tissue injury in CHB patients with 1-2×ULN accounted for 41.99%, 41.85% and 50.30%, respectively. The optimal ALT critical values were 33 U/L for overall patients, 25 U/L for females, 45 U/L for males, 45 U/L for ≤30 years olds, 33 U/L for>30 years olds, 22 U/L for HBeAg negative and 31 U/L for HBeAg positive patients. Conclusions The threshold of ALT for initiating antiviral therapy in chronic HBV patients should be individualized, especially should be down-regulated for the females, olders and HBeAg-negative patients.

The anatomical limit and strategies for molar movement during orthodontic treatment / 口腔疾病防治

@#In many cases, tooth movement over a considerable distance is needed to meet the major goal of orthodontic treatment, which has always been to correct malocclusion and improve the facial profile in patients with skeletal malocclusion. However, tooth movement over a considerable distance also carries risks of dehiscence, fenestration, root exposure, and so forth. The reason lies in neglecting many limits for tooth movement, especially anatomical characteristics. This review focuses on structural limits for orthodontic molar movement, such as the alveolar cortex, the maxillary sinus floor, and the mandibular canal. In addition, we set the strategy in clinical orthodontics. For the alveolar cortex and the mandibular canal, orthodontists are recommended to move the root away from the cortical bone initially and formulate personalized molar movement plans according to clinical examination and cone-beam computed tomography (CBCT) and other imaging examinations. First, the molar root was controlled by torque away from the bone plate, and then, the molar movement amount and direction were controlled according to the personalized movement path. In regard to the maxillary sinus floor, light and continuous forces and scientific biomechanics are suitable for bodily tooth movement. In summary, better therapeutic efficacy and long-term stabilization could be achieved by circumventing the limits and risks caused by anatomical limitations and characteristics.

Study on the sensitivity of a volumetric modulated arc therapy plan verification equipment on multi-leaf collimator opening and closing errors and its gamma pass rate limit / 生物医学工程学杂志

To investigate the γ pass rate limit of plan verification equipment for volumetric modulated arc therapy (VMAT) plan verification and its sensitivity on the opening and closing errors of multi-leaf collimator (MLC), 50 cases of nasopharyngeal carcinoma VMAT plan with clockwise and counterclockwise full arcs were randomly selected. Eight kinds of MLC opening and closing errors were introduced in 10 cases of them, and 80 plans with errors were generated. Firstly, the plan verification was conducted in the form of field-by-field measurement and true composite measurement. The γ analysis with the criteria of 3% dose difference, distance to agreement of 2 mm, 10% dose threshold, and absolute dose global normalized conditions were performed for these fields. Then gradient analysis was used to investigate the sensitivity of field-by-field measurement and true composite measurement on MLC opening and closing errors, and the receiver operating characteristic curve (ROC) was used to investigate the optimal threshold of γ pass rate for identifying errors. Tolerance limits and action limits for γ pass rates were calculated using statistical process control (SPC) method for another 40 cases. The error identification ability using the tolerance limit calculated by SPC method and the universal tolerance limit (95%) were compared with using the optimal threshold of ROC. The results show that for the true composite measurement, the clockwise arc and the counterclockwise arc, the descent gradients of the γ passing rate with per millimeter MLC opening error are 10.61%, 7.62% and 6.66%, respectively, and the descent gradients with per millimeter MLC closing error are 9.75%, 7.36% and 6.37%, respectively. The optimal thresholds obtained by the ROC method are 99.35%, 97.95% and 98.25%, respectively, and the tolerance limits obtained by the SPC method are 98.98%, 97.74% and 98.62%, respectively. The tolerance limit calculated by SPC method is close to the optimal threshold of ROC, both of which could identify all errors of ±2 mm, while the universal tolerance limit can only partially identify them, indicating that the universal tolerance limit is not sensitive on some large errors. Therefore, considering the factors such as ease of use and accuracy, it is suggested to use the true composite measurement in clinical practice, and to formulate tolerance limits and action limits suitable for the actual process of the institution based on the SPC method. In conclusion, it is expected that the results of this study can provide some references for institutions to optimize the radiotherapy plan verification process, set appropriate pass rate limit, and promote the standardization of plan verification.

Determination of 10 mycotoxins in Hippophae Fructus medicinal and edible products by ultra-performance liquid chromatography- tandem mass spectrometry / 中国中药杂志

An analytical method for 10 mycotoxins in Hippophae Fructus medicinal and edible products was established in this study, and the contamination of their mycotoxins was analyzed. First of all, the mixed reference solution of ten mycotoxins such as aflatoxin, ochratoxin, zearalenone, and dexoynivalenol was selected as the control, and the Hippophae Fructus medicinal and edible products were prepared. Secondly, based on the ultra-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) technology, 10 mycotoxins in Hippophae Fructus medicinal and edible products were quantitatively investigated and their content was determined. Finally, the contamination of mycotoxins was analyzed and evaluated. The optimal analysis conditions were determined, and the methodological inspection results showed that the 10 mycotoxins established a good linear relationship(r>0.99). The method had good repeatability, test sample specificity, stability, and instrument precision. The average recovery rates of 10 mycotoxins in Hippophae Fructus medicinal products, edible solids, and edible liquids were 90.31%-109.4%, 87.86%-107.8%, and 85.61%-109.1%, respectively. Relative standard deviation(RSD) values were 0.22%-10%, 0.75%-13%, and 0.84%-8.5%, repsectively. Based on UPLC-MS/MS technology, the simultaneous determination method for the limits of 10 mycotoxins established in this study has fast detection speed, less matrix interference, high sensitivity, and accurate results, which is suitable for the limit examination of 10 mycoto-xins in Hippophae Fructus medicinal and edible products.

Knowledge, attitude, and practices of 2nd year MBBS students regarding the use of face mask to limit the spread of the new coronavirus disease

Background: The onset of the aggressive Coronavirus disease 19 (COVID-19) pandemic has necessitated masks for the health care community. For healthcare workers, proper knowledge, a good attitude and increased comfortability with masks are of great essence. Knowledge of proper use and handling of masks among health care workers and medical students is of utmost importance as they protect the wearer and those around from transmission of infection. Aim and Objectives: To assess the Knowledge, Attitude, and Practices of 2nd year MBBS Students Regarding the Use of Face Mask to Limit the Spread of the New COVID-19. Materials and Methods: After obtaining ethical approval from the Institutional Ethical Committee with an ethical approval no. of IEC/2020/2/42, a questionnaire with 14 questions was prepared to investigate the knowledge, attitude, practices, and problems faced by 2nd Year MBBS students with regards to wearing a face mask during the COVID-19 pandemic. The questionnaire was sent electronically, consent was obtained and the responses were analyzed. Results: Assessment of knowledge revealed that 87.3% of participants knew the correct way of using a mask, 87.3% knew that there are three layers in it and 83.3% knew that the middle layer acts as the filter media barrier. Only 32.4% of participants knew that a surgical mask can be used for 8 hours and 92.2% incorrectly indicated cloth masks to be as effective in protection from COVID-19 as surgical masks are. About 97.1% of participants knew the purpose of metal strips and 93.1% knew the extent to which a surgical mask must cover. The attitude was excellent with 95.1% of participants believing that surgical masks can help, 90.2% saying they knew the steps of wearing a mask, and participants wearing masks at all times when conversing with patients and in public as well. Perturbingly, only 24.5% of participants faced no issues when wearing a mask. Conclusion: Overall, respondents displayed thorough knowledge and exuded a highly positive attitude but less than a fourth of respondents faced no issues while wearing a mask. Continued educational efforts and more research into mask comfort is the need of the hour.

Evaluación radiográfica de 5000 tratamientos endodónticos realizados en premolares y molares mandibulares y maxilares en una población en Argentina / Radiographic evaluation of 5000 endodontic treatments performed on mandibular and maxillary premolars and molars in a population in Argentina

Objetivo: Evaluar radiográficamente tratamientos en- dodónticos del sector posterior de la cavidad bucal y com- parar la frecuencia de aceptabilidad en cada pieza dentaria involucrada. Materiales y métodos: Se evaluaron 5000 radiogra- fías de archivo de tratamientos endodónticos realizados apro- ximadamente entre 2005 y 2019 en premolares y molares mandibulares y maxilares en Argentina. Se consideraron tratamientos correctos e incorrectos de acuerdo con: 1) con- formación de la preparación quirúrgica; 2) límite apical de la obturación; 3) homogeneidad de la obturación. Se obtuvo la fre- cuencia absoluta y relativa de correctos e incorrectos. El aná- lisis entre frecuencias y pieza dentaria se realizó con la prueba de chi cuadrado y el cálculo del coeficiente V de Cramer. Para la comparación entre grupos de piezas dentarias se utilizó la partición del valor de chi cuadrado obtenido en los corres- pondientes grados de libertad. Nivel de significación P <0.05. Resultados: La partición del valor de chi cuadrado no mostró diferencias significativas entre primeros y segundos premolares mandibulares. Las otras comparaciones exhibie- ron diferencias significativas. Conclusiones: Un alto porcentaje de los tratamientos endodónticos de la población estudiada tiene por lo menos una condición que permite categorizarlos como incorrectos según el criterio establecido en este trabajo. Este porcentaje es más preponderante en anatomías complejas (AU)

Aim: To evaluate radiographically endodontic treat- ments performed in the posterior area of the oral cavity and compare the frequency of acceptability in each tooth involved. Materials and methods: 5,000 archival radiographs of endodontic treatments performed between 2005 and 2019 on mandibular and maxillary premolars and molars in Argentina were evaluated. The percentages of correct and incorrect treatments were considered according to 1) shaping of the preparation; 2) apical limit of the obturation; 3) homogeneity of the obturation. The absolute and relative frequencies of correct and incorrect treatments were calcu- lated. The association between these frequencies and tooth type was analyzed using the chi-square test and Cramer's V coefficient. For the comparison between groups of teeth, the partition of the chi-square value obtained in the corre- sponding degrees of freedom was used. Level of significance was P <0.05. Results: The partition of the chi-square value did not show a significant difference between the first and second lower premolars. The differences were significant in the other comparisons. Conclusions: A high percentage of the endodontic treat- ments in the study population have at least one condition war- ranting their classification as incorrect according to the crite- ria established in this study. This percentage is more prevalent in complex anatomies (AU)

Static balance and limits of stability in patients with cervical vertigo / 中国康复理论与实践

@#Objective To analyze the characteristics of static balance and limits of stability (LOS) in patients with cervical vertigo (CV). Methods From January, 2020 to August, 2021, 30 CV patients in our hospital (vertigo group) and 30 healthy people (control group) were selected and tested with PRO-KIN system, under the conditions of eyes open and closed. The standard deviation of the vertical and horizontal amplitude, the mean of vertical and horizontal sway velocities, the area of the movement, the length of the movement, and LOS at eight directions, The Romberg ratios of the area and the length were caculated. Results All the indicators of the static balance were higher under eyes closed than under eyes open in both groups (|Z| > 2.138, P < 0.05); whether under the eyes open or closed, the static balance indicators were higher in the vertigo group than in the control group (|Z| > 2.004, P < 0.05), except for the mean of horizontal sway velocities (|Z| < 1.026, P > 0.05). The LOS and total LOS completion percentage in the front (upper right, right above, upper left) were lower in the vertigo group than in the control group (|Z| > 2.240, P < 0.05). Conclusion The static balance abilities decrease for CV patients, and the balance control depends on visual compensation. The range of LOS reduces, means a higher risk of falling.

Control strategy for the limit of aldehydes in polysorbates based on genotoxicity and influence on the aggregation of monoclonal antibody / 中国药科大学学报

@#An HPLC pre-column derivatization detection method was established to detect and analyze the formaldehyde and acetaldehyde in polysorbate 80 and polysorbate 20 from different manufacturers.The effects of aldehyde and acetaldehyde on the aggregation of adalimumab under different conditions were monitored.Based on the control of genotoxic impurities and the influence on the stability of monoclonal antibody preparations, the control limits of the two chemicals were preliminarily obtained.2, 4-dinitrophenylhydrazine (2, 4-DNPH) was applied as the derivatization reagent in HPLC pre-column derivatization; acetonitrile and water were used as mobile phase to perform a gradient elution on a C8 (4.6 mm × 150 mm, 5 μm) chromatographic column.The detection wavelength was 360 nm, and the external standard method was used for quantification.Verification results showed that the method was suitable for the quantitative analysis of trace formaldehyde and acetaldehyde in polysorbate 80 and polysorbate 20 . The detection and analysis of formaldehyde or acetaldehyde in different batches of polysorbate 80 and polysorbate 20 from different manufacturers showed that the content of formaldehyde and acetaldehyde were quite different. The content of formaldehyde and acetaldehyde in polysorbate 80 were significantly higher than those of polysorbate 20. After monitoring the changes of adalimumab aggregates treated by formaldehyde and acetaldehyde by size exclusion chromatography (SEC), it was found that the effect of formaldehyde on adalimumab aggregation was significantly higher than that of acetaldehyde.According to the requirements of ICH M7 (International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use, M7: Assessment and Control of DNA Reactive (Mutagenic) Impurities in Pharmaceuticals to Limit Potential Carcinogenic Risk), the impurity limits of formaldehyde and acetaldehyde in polysorbate 80 and polysorbate 20 for monoclonal antibody preparations were calculated from the perspective of risk assessment.Combined with the influence on the aggregation stability of monoclonal antibodies, the preliminary limis for acetaldehyde and acetaldehyde were recommended to be ≤ 7 μg/g and ≤ 765 μg/g, respectively.

Bacterial Endotoxin for Intrathoracic Medical Devices Requirement Revisited / 中国医疗器械杂志

Bacterial endotoxin is considered as one of the critical risk factors in medical devices, especially implanted devices that directly or indirectly contact with blood circulating system. In that case, endotoxin limits for implanted medical devices is important in determine the safety of medical devices. According to GB/T 14233.2-2005, the requirements of endotoxin index for intrathoracic medical devices is 2.15 EU per device. However, the definition of "intrathoracic medical devices" is vague. Specifically, "for cardiovascular system application" instead of "intrathoracic application" is more reasonable. With the deeper understanding of the risk of endotoxin in medical devices and considering the internationally accepted standards, the limits of endotoxin in medical devices for cardiovascular system application is acceptable at 20 EU per device.

Safety risk assessment of fluoride in brick-tea and consideration and suggestions on its limit in China at the present stage / 中华地方病学杂志

Drinking brick-tea type of endemic fluorosis is a kind of chronic fluorosis caused by excessive intake of fluoride into the body from long-term and high consumption of brick-tea, milk tea, butter tea, or other tea drinks with high fluoride content. It mainly distributes in seven western provinces of China, including Tibet Autonomous Region, Qinghai Province, Sichuan Province, Xinjiang Uygur Autonomous Region, Inner Mongolia Autonomous Region, Gansu Province, and Ningxia Hui Autonomous Region. In order to govern the production and sale of brick-tea and control the epidemic of drinking brick-tea type of endemic fluorosis, the former Ministry of Health of China issued the national standard "Fluoride Content of Brick-tea" (GB 19965-2005) in 2005, which stipulated that the total amount of water-soluble inorganic fluorine in brick-tea should not exceed 300 mg/kg. In the past 20 years, the prevalence of drinking brick-tea type of endemic fluorosis in China became clear gradually, and the habit of drinking brick-tea of residents in the epidemic fluorosis area also changed to some extent. In this paper, the dose-effect relationship between fluoride intake from brick-tea and skeletal fluorosis is reviewed, the brick-tea consumption of residents in the endemic fluorosis areas is analyzed, and the safety risk of brick-tea fluoride exposure is evaluated. It is suggested that the fluoride limit of brick-tea, ≤300 mg/kg, is still suitable for the prevention and control of drinking brick-tea type of endemic fluorosis in China at the present stage.

Comparison of occupational exposure limits of hexavalent chromium compounds in China and foreign workplaces / 中国职业医学

@#Objective To compare and analyze the occupational exposure limit（OEL）of hexavalent chromium compounds in China and foreign countries. Methods The OEL and background information of hexavalent chromium compounds released by nine official and unofficial organizations in seven countries/regions were collected and sorted. The classification，limit levels， formulation principles and compound characteristics labeling of OEL were compared. Results The OEL values published by nine organizations ranged from 0.000 02 to 0.050 00 mg/m3 . Among them，the limits of seven organizations（including China） did not clearly distinguish the soluble types of hexavalent chromium compounds；the limits of eight organizations（including China）were calculated in terms of chromium；seven organizations（including China）have only developed OEL for long-term exposure. The OEL of hexavalent chromium in China was 0.050 00 mg/m3 which is relatively loose. Its carcinogenicity label was consistent with international standards，its sensitization label was consistent with some countries，and its percutaneous absorption label had not been included in the characteristic labeling of limit values. Conclusion It is suggested that the OEL of hexavalent chromium in China should be revised timely，and the systemic adverse effects caused by percutaneous absorption of hexavalent chromium compounds should be focused on. At the same time，it is recommended to systematically adjust the management concepts and principles of all carcinogens.

Establishment and analysis of microbial limit test methods for commonly used pediatric drugs / 上海预防医学

ObjectiveTo establish microbial limit test methods for 44 pediatric drugs. MethodsAccording to the general guidelines in Chinese Pharmacopoeia （2015 and 2020 edition， volume Ⅳ），a suitability test of the methods for 44 drugs was carried out by pour-plate method， neutralization method or dilution method. ResultsTotal aerobic microbial count： chemical oral liquid samples can be tested by 1∶10 plate method；traditional Chinese medicine need to be neutralized firstly. Then oral liquids could be tested by 1∶10 plate method and 1∶100 plate method was used for granules. Total count of molds and yeasts： all the samples can be tested by the 1∶10 plate method. The recoveries of five test strains were between 0.5 and 2.0. The specified microorganisms were all detected in the test group， while not found in the negative control group. ConclusionThe microbial limit test methods for the 44 pediatric drugs are established and the results are reliable and can be used in the quality control．