Objective:To study the influence of image panel of different source image distances(SID)of beam central axis of Portal Dosimetry(PD)dose verification system on the verification of volumetric modulated arc therapy(VMAT)plan,so as to provide reference for dose verification in selecting the appropriate SID position and evaluation criteria.Methods:From July 2022 to May 2024,10 patients,who received radiotherapy on tumor at different-site in Specialized Medical Center of the Chinese People's Armed Police Force,were selected.All patients underwent VMAT.Ten simulated dose verification plans were established according to the data of patients,with a total of 10 arcs.The non-crystalline silicon image panel was calibrated at 0,-30,-40,-50 and-60 cm from the isocenter on the beam central axis,and the verification plans of PD system were established.Dose verification was carried out using electronic portal imaging device(EPID)(a-Si EPID)of non-crystalline silicon image panel that was onboard by accelerator.The γ pass rates under the standards of 3%/3 mm and 3%/2 mm were compared and analyzed.Results:Under the evaluation standard of 3%/3 mm,the γ pass rates of the collected doses were(98.93±0.81)%,(94.77±9.00)%,(92.18±11.34)%,(89.72±12.54)%and(87.05±13.06)%when the SID values were respectively 100,130,140,150 and 160 cm,which were all higher than these under the evaluation standard of 3%/2 mm,and the differences were statistically significant(t=2.75,3.44,3.59,4.16,6.47,P<0.05).There were significant differences between the average γ pass rate of the collected dose under evaluation standards of 3%/3 mm and 3%/2 mm when SID was 100cm,and the 100%of γ pass rate(t=-3.21,-3.62,P<0.05),while the differences of the obtained γ pass rates among other SID positions were not statistically significant(P>0.05).Conclusion:Under the evaluation standards of 3%/3 mm and 3%/2 mm,the γ pass rate of the collected dose at SID 100 cm is the highest.The γ pass rate of the collected dose at SID 130 cm can meet the basically clinical requirements.In EPID dose verification,the collection for dose should be prioritized for selection when SID was 100 cm,and the γ pass rate of dose verification is higher,the influence of interference is less at this time,which verification results have higher credibility.

Objective:To study the influence of image panel of different source image distances(SID)of beam central axis of Portal Dosimetry(PD)dose verification system on the verification of volumetric modulated arc therapy(VMAT)plan,so as to provide reference for dose verification in selecting the appropriate SID position and evaluation criteria.Methods:From July 2022 to May 2024,10 patients,who received radiotherapy on tumor at different-site in Specialized Medical Center of the Chinese People's Armed Police Force,were selected.All patients underwent VMAT.Ten simulated dose verification plans were established according to the data of patients,with a total of 10 arcs.The non-crystalline silicon image panel was calibrated at 0,-30,-40,-50 and-60 cm from the isocenter on the beam central axis,and the verification plans of PD system were established.Dose verification was carried out using electronic portal imaging device(EPID)(a-Si EPID)of non-crystalline silicon image panel that was onboard by accelerator.The γ pass rates under the standards of 3%/3 mm and 3%/2 mm were compared and analyzed.Results:Under the evaluation standard of 3%/3 mm,the γ pass rates of the collected doses were(98.93±0.81)%,(94.77±9.00)%,(92.18±11.34)%,(89.72±12.54)%and(87.05±13.06)%when the SID values were respectively 100,130,140,150 and 160 cm,which were all higher than these under the evaluation standard of 3%/2 mm,and the differences were statistically significant(t=2.75,3.44,3.59,4.16,6.47,P<0.05).There were significant differences between the average γ pass rate of the collected dose under evaluation standards of 3%/3 mm and 3%/2 mm when SID was 100cm,and the 100%of γ pass rate(t=-3.21,-3.62,P<0.05),while the differences of the obtained γ pass rates among other SID positions were not statistically significant(P>0.05).Conclusion:Under the evaluation standards of 3%/3 mm and 3%/2 mm,the γ pass rate of the collected dose at SID 100 cm is the highest.The γ pass rate of the collected dose at SID 130 cm can meet the basically clinical requirements.In EPID dose verification,the collection for dose should be prioritized for selection when SID was 100 cm,and the γ pass rate of dose verification is higher,the influence of interference is less at this time,which verification results have higher credibility.

Objective To establish an analytical method of LC-MS/MS based on micro-segmentation analysis of multiple hairs,verify the detection of 20 benzodiazepines in 1mm hair,and finally use it for case detection analysis.Methods 5 hairs were cut into 1mm long segments each,and the corresponding segments were immersed and sonicated in an extract containing dithiothreitol,methanol,etc.Mobile phase A was 0.1%formic acid in water,and mobile phase B was acetonitrile.Data were collected using electrospray ion source positive ion mode in multiple reaction monitoring mode.Results The 20 benzodiazepines in multiple hairs had a good linear relationship(r>0.99),detection limit of 0.2～5 pg/mm,minimum quantification limit of 0.5 to 20 pg/mm,the intro-day and inter-day precisions of 2.03%to 13.81%,the intro-day and inter-day accuracies of 87.98%～111.29%,matrix effect of 71.15%～110.43%,and extraction recovery of 69.34%to 99.94%.Using this method,hair samples were analyzed in volunteers taking a single dose of clonazepam for 20 days,and the detected location of clonazepam in 15 hairs was located in segment 6～11 from the hair root,with the concentration range of 1.06～3.45 pg/mm.By this method,the hair of the victims suspected of having taken sleeping pills in the case was analyzed.In 15 hairs,clonazepam was detected in segments 9～13 of the hair root.The quantitative results were 1.07～19.06 pg/mm.The experimental results were basically consistent with the medication time of the victim.Conclusion The micro-segmentation analysis technique of multiple hairs can be applied to the investigation of drug-assisted crime cases,and can roughly estimate the medication time.

Objective To establish an analytical method of LC-MS/MS based on micro-segmentation analysis of multiple hairs,verify the detection of 20 benzodiazepines in 1mm hair,and finally use it for case detection analysis.Methods 5 hairs were cut into 1mm long segments each,and the corresponding segments were immersed and sonicated in an extract containing dithiothreitol,methanol,etc.Mobile phase A was 0.1%formic acid in water,and mobile phase B was acetonitrile.Data were collected using electrospray ion source positive ion mode in multiple reaction monitoring mode.Results The 20 benzodiazepines in multiple hairs had a good linear relationship(r>0.99),detection limit of 0.2～5 pg/mm,minimum quantification limit of 0.5 to 20 pg/mm,the intro-day and inter-day precisions of 2.03%to 13.81%,the intro-day and inter-day accuracies of 87.98%～111.29%,matrix effect of 71.15%～110.43%,and extraction recovery of 69.34%to 99.94%.Using this method,hair samples were analyzed in volunteers taking a single dose of clonazepam for 20 days,and the detected location of clonazepam in 15 hairs was located in segment 6～11 from the hair root,with the concentration range of 1.06～3.45 pg/mm.By this method,the hair of the victims suspected of having taken sleeping pills in the case was analyzed.In 15 hairs,clonazepam was detected in segments 9～13 of the hair root.The quantitative results were 1.07～19.06 pg/mm.The experimental results were basically consistent with the medication time of the victim.Conclusion The micro-segmentation analysis technique of multiple hairs can be applied to the investigation of drug-assisted crime cases,and can roughly estimate the medication time.

Illness anxiety disorder (IAD) is a psychiatric disorder defined by excessive worry about having or developing a serious undiagnosed medical condition. IAD can affect the social functions of patients and increase burdens imposed on the family and society. The concept of IAD was first proposed in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) in 2013. However, the rates of screening and identification of IAD are at a relatively low level in clinical practice, and the effectiveness of pharmacological and psychological intervention on IAD are still in the process of exploration and validation. The recognition of IAD should be enhanced and the efficacy of intervention need to be further improved. This article reviews the progress of clinical studies on IAD to improve clinicians′ understanding of the disease, and help them adopt appropriate treatments as early as possible to alleviate patient suffering and improve disease prognosis.

Illness anxiety disorder (IAD) is a psychiatric disorder defined by excessive worry about having or developing a serious undiagnosed medical condition. IAD can affect the social functions of patients and increase burdens imposed on the family and society. The concept of IAD was first proposed in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) in 2013. However, the rates of screening and identification of IAD are at a relatively low level in clinical practice, and the effectiveness of pharmacological and psychological intervention on IAD are still in the process of exploration and validation. The recognition of IAD should be enhanced and the efficacy of intervention need to be further improved. This article reviews the progress of clinical studies on IAD to improve clinicians′ understanding of the disease, and help them adopt appropriate treatments as early as possible to alleviate patient suffering and improve disease prognosis.

Objective: To understand the prevalence of facility-based HIV testing and its associated factors among men who have sex with men (MSM) in Beijing city. Methods: An application-based cross-sectional survey was employed to understand HIV site test situation and associated factors. The survey was carried out from May 14^th to 21^st, 2016. Users of a smart phone application for gay dating were recruited and those eligible for this survey were investigated with an online self-administered questionnaire. Information of demographics, sexual behaviors, facility-based HIV testing history and recreational drug abuses were collected. The multivariate logistic regression was used to make comparison among different groups and assess associated factors. Results: A total of 7 494 participants were enrolled in the survey with mean age of (28.81 ± 7.38) years, 87.14% (6 530/7 494) sought sexual partners through internet. The proportion of facility-based HIV testing in 1 year was 42.55% (3 189/7 494), MSM who were 25-29 years had higher proportion of facility-based HIV testing in 1 year, the proportion was 45.56%(1 104/2 423). Among MSM who could insist in using condom during anal sex (50.46% (1 539/3 050)), the proportion of HIV site testing in 1 year was higher. The MSM who reported seeking healthcare for symptoms of a sexually transmitted infections (STIs) in the past year or ever using recreational drug had higher proportion of facility-based HIV testing, the proportions were 56.81% (409/720) and 52.00% (1 340/4 917), respectively. Compared with alone cohabitation, cohabitating was associated with decreased odds of HIV facility-based testing in past 1 year(odds ratio (OR)= 0.79, P<0.001). Compared with homosexual sexual orientation, bisexual sexual orientation was associated with decreased odds of facility-based HIV testing (OR=0.83, P=0.004). With the increasing of number of male anal sex partners, the odds of HIV facility-based testing was increasing (OR=1.31, P<0.001) But with the decreasing of the frequency of condom using with male anal sex partners, the odds of facility-based HIV testing was decreasing (OR=0.85, P=0.014). Using recreational drugs (OR=1.36, P<0.001) and seeking healthcare for symptoms of a STI in the past 1 year (OR=1.73, P<0.001) were associated with decreased odds of HIV site testing. Conclusion MSM in Beijing had lower proportion of facility-based HIV testing in past 1 year. Multiple anal sex partners, using recreational drugs, seeking healthcare for symptoms of a STI in the past year, cohabitating, bisexual sexual orientation, and lower frequency of condom using with male anal sex partners were associated with the odds of HIV facility-based testing in past 1 year.

Carcinoma of pancreas is the most common primar y pancreatic malignancy. Symptoms usually are nonspecific and include abdominal pain, jaundice, loss of appetite, weight loss, nausea, and vomiting. CT usually demonstrates a mass with ill-defined margins but also solid components and dil atation of the main pancreatic duct. This tumor is usually smaller and virtuall y never contains calcification. Following contrast material administration,all masses were enhanced less than the surrounding pancreas. Tumors were oval, rou nd or lobular,and is almost always locally invasive. These features can be used to differentiate carcinoma of pancreas from other pancreatic tumors.

Object To compare the content in corilagin of Phyllanthus urinaria L. harvested from ten different regions of China in different months. Methods The content of corilagin was determined by UV spectrophotometry, detective wavelength is 270 nm. Results The content of corilagin in P. urinaria from Hainan and Guizhou province was the lowest, 0 58%. The highest content was given by the plant from Xi'an zone, Shanxi province, 1 78%. The best harvest time is in August and September, content of corilagin is 1 24%. Conclusion The difference of the corilagin contents in P urinaria . harvested from different regions and in different harvest time in the same region is great.