Secondary metabolites from the Actinomadura sp. and their cytotoxic activity

Actinomadura sp., which is usually found in muddy habitats, produces various secondary metabolites with biological activities. In this study, five new compounds named formosensin A (1), formosensin B (2), oxanthroquinone-3-O-α-d-mannose (8), oxanthromicin A (9), and oxanthromicin B (10) were isolated from the culture of Actinomadura sp. together with five known compounds (3-7). Their structures were elucidated by extensive spectroscopic methods including NMR and MS. In particular, the absolute configurations of compounds 1 and 2 were determined using computational methods. Moreover, compounds 1-2 and 8-10 were screened for cytotoxic activity using a panel of human tumor cell lines. Compound 9 induced significant cytotoxicity in five human tumor cell lines (HL-60, A-549, SMMC-7721, MCF-7, and SW480) with IC50 values of 8.7, 17.5, 15.0, 17.8, and 14.6 μM, respectively. These findings suggested that compound 9 could provide therapeutic benefits in the treatment of tumor-related diseases.

[Annual progress in pulmonary rehabilitation 2023]

Pulmonary rehabilitation is a key component of long-term management strategies for chronic respiratory diseases (CRD). This comprehensive intervention, carefully tailored to individual patients based on thorough assessments, has undergone significant expansion and refinement toward personalization and precision in recent years. This review consolidates findings from studies published between October 2022 and September 2023, covering advances in CRD rehabilitation, assessment criteria, mechanisms, and innovative equipments. The primary objective is to enhance the knowledge base of healthcare professionals and pave the way for future research efforts in this important area.

[An analysis of long-term survival trends for nasopharyngeal carcinoma in Qidong, Jiangsu]

Objective: To analyze the survival of nasopharyngeal carcinoma patients in Qidong from 1972 to 2016, and provide a basis for the prognosis evaluation and prevention for nasopharyngeal carcinoma patients. Methods: A total of 1 060 registered nasopharyngeal carcinoma patients were followed up for survival outcomes until December 31, 2021. Observed survival rate (OSR) and relative survival rate (RSR) was calculated by Hakulinen method in SURV3.01 software, and Hakulinen's likelihood ratio test was used for statistical difference comparison. Age-standardized relative survival rate (ARSR) was calculated according to the International Cancer Survival Standard (ICSS). Joinpoint 4.7.0.0 software was used to conduct the annual average percentage change (AAPC) in nasopharyngeal carcinoma survival rate. The period from 1972 to 2016 is divided into 9 periods for grouping processing according to 5 years. Results: The OSR of nasopharyngeal carcinoma at 1, 5, 10 years were 63.02%, 34.70% and 24.72%, the RSR at 1, 5, 10 years were 64.44%, 38.98% and 31.64%, respectively. The uptrends of RSR in the nine periods were statistically significant (χ(2)=112.16, P<0.001). The 1, 5, 10 years RSR for males were 62.66%, 35.89% and 27.94%, while the 1, 5, 10 years RSR for females were 68.30%, 45.67% and 39.68%, respectively. There was no statistically significant difference in RSR between males and females (χ(2)=14.16, P=0.656). The 5-year RSR for the age groups of 25-34, 35-44, 45-54, 55-64, 65-74, and over 75 years old were 52.83%, 40.92%, 42.64%, 38.65%, 27.23% and 28.88%, respectively. There was a statistically significant difference in RSR among different age groups (χ(2)=42.33, P=0.003). Moreover, the ARSR of nasopharyngeal carcinoma at 1, 5, 10 years were 63.64%, 37.33% and 27.10%, for males were 61.82%, 35.60% and 25.20%, for females were 68.36%, 43.12% and 32.93%. Period trend showed that the AAPC of 5-ARSR was 2.71% (t=7.47, P<0.001) from 1972 to 2016 in Qidong. The AAPC of 5-ARSR in males and females were 2.63% (t=4.98, P=0.002) and 2.71% (t=6.08, P=0.001). There was statistically significant increase in 5-year ARSR among both genders. Furthermore, the AAPC of 5-year RSR among 25-34, 35-44, 45-54, 55-64, 65-74 and 75+ years old were 2.16% (t=4.28, P=0.004), 3.38% (t=5.06, P=0.001), 1.99% (t=2.82, P=0.026), 2.82% (t=3.39, P=0.012), 2.20% (t=2.82, P=0.026) and -0.91% (t=-0.42, P=0.689), respectively. Except for the 75+ years old age group, the other age groups were significantly upward trend. Conclusions: The overall survival rate of nasopharyngeal carcinoma in Qidong from 1972 to 2016 has shown an upward trend. It is necessary to introduce standardized multi-disciplinary treatment mode to improve treatment effect and survival rate.

[Long-term trend analysis of liver cancer survival rate in Qidong region, Jiangsu Province, 1972-2019]

Objective: To analyze the incidence and survival rate of liver cancer cases in the entire population in the Qidong region from 1972 to 2019, so as to provide a basis for prognosis evaluation, prevention, and treatment. Methods: The observed survival rate (OSR) and relative survival rate (RSR) of 34 805 cases of liver cancer in the entire Qidong region population from 1972 to 2019 were calculated using Hakulinen's method with SURV3.01 software. Hakulinen's likelihood ratio test was used for statistical analysis. Age-standardized relative survival (ARS) was calculated using the International Cancer Survival Standard. The Joinpoint regression analysis was performed with Joinpoint 4.7.0.0 software to calculate the average annual percentage change (AAPC) of the liver cancer survival rate. Results: 1-ASR increased from 13.80% in 1972-1977 to 50.20% in 2014-2019, while 5-ASR increased from 1.27% in 1972-1977 to 27.64% in 2014-2019. The upward trend of RSR over eight periods was statistically significant (χ (2) = 3045.29, P < 0.001). Among them, male 5-ASR was 0.90%, 1.80%, 2.33%, 4.92%, 5.43%, 7.05%, 10.78%, and 27.78%, and female 5-ASR was 2.33%, 1.51%, 3.35%, 3.92%, 3.84%, 7.18%, 11.45%, and 29.84%, respectively. There was a statistically significant difference in RSR between males and females (χ (2) = 45.68, P < 0.001). The 5-RSR for each age group of 25-34 years old, 35-44 years old, 45-54 years old, 55-64 years old, 65-74 years old, and 75 years old were 4.92%, 5.29%, 8.17%, 11.70%, 11.63%, and 9.60%, respectively. There were statistically significant differences in RSR among different age groups (χ (2) = 501.29, P < 0.001). The AAPC in Qidong region from 1972 to 2019 for 1-ARS, 3-ASR, and 5-ARS were 5.26% (t = 12.35, P < 0.001), 8.10% (t = 15.99, P < 0.001), and 8.96 % (t = 16.06, P < 0.001), respectively. The upward trend was statistically significant in all cases. The AAPC of 5-ARS was 9.82% in males (t = 14.14, P < 0.001), and 8.79% in females (t = 11.48, P < 0.001), and the upward trend was statistically significant in both. The AAPC of 25-34 years old, 35-44 years old, 45-54 years old, 55-64 years old, 65-74 years old, and 75 years old were 5.37% (t = 5.26, P = 0.002), 5.22% (t = 5.66, P = 0.001), 7.20% (t = 6.88, P < 0.001), 10.00% (t = 12.58, P < 0.001), 9.96% (t = 7.34, P < 0.001) and 8.83% (t = 3.51, P = 0.013), and the upward trend was statistically significant. Conclusion: The overall survival rate of registered cases of liver cancer in the Qidong region's entire population has greatly improved, but there is still much room for improvement. Hence, constant attention should be paid to the study on preventing and treating liver cancer.

[Establishment of diagnostic model for schizophrenia based on neurotrophic factor and other biomarkers]

Objective: To construct a diagnostic model of schizophrenia (SCZ) based on biomarkers such as serum neurotrophic factor. Methods: Patients of schizophrenia (SCZ group) and healthy controls (HC group) who were admitted to the First Affiliated Hospital of Zhengzhou University from January 2017 to December 2019 were prospectively selected. In the SCZ group, the mental symptoms were assessed by the positive and negative symptom scale (PANSS), cognitive function was assessed by the MATRICS consensus cognitive battery (MCCB), brain-derived neurotrophic factor (BDNF), glial cell derived neurotrophic factor (GDNF), fasting glucose (FGB) and fasting insulin (FINS) levels were detected, and insulin resistance (HOMA-IR) was calculated. The same methods were used to evaluate cognitive function, measure BDNF, GDNF, FGB and FINS levels, and calculate HOMA-IR in HC group. The indexes with statistically significant differences between the two groups were selected to be included in the model. The diagnostic model was constructed by machine learning and verified by cross-validation method, the receiver operating curve (ROC) was plotted, and the area under the curve (AUC), sensitivity and specificity were calculated. Results: (1) A total of 142 patients (70 males and 72 females) with schizophrenia were finally included, and aged (25±4) years. Meanwhile, 140 healthy controls (72 males and 68 females) were also enrolled, and aged (26±4) years. In SCZ group, scores in all areas of cognitive function were lower than those in HC group (all P<0.001), the levels of serum BDNF and GDNF [(6.7±1.8) ng/ml and (405±93) pg/ml] were also lower than those in HC group [(12.3±3.2) ng/ml and (574±139) pg/ml] (both P<0.001), but the levels of FINS and HOMA-IR [(8.4±0.8) μU/ml and 1.7±0.3] were higher than those in HC group [(6.7±0.9) μU/ml and 1.4±0.3] (both P<0.001). (2) Correlation analysis showed that the level of serum BDNF had a negative correlation with negative symptom scores and total scores (r=-0.31, P<0.001; r=-0.17, P=0.040), but had a positive correlation with attention/alertness (CPT-IP) T scores, working memory (WSM-Ⅲ) T scores and visual learning (BVMT) T scores in SCZ group (r=0.39, 0.37 and 0.29, all P<0.001). The level of serum GDNF also had a positive correlation with CPT-IP T scores, WSM-Ⅲ T scores and BVMT T scores (r=0.32, P<0.001; r=0.23, P=0.007; r=0.40, P<0.001). The values of HOMA-IR had a positive correlation with social cognition (MSCEIT) T scores in SCZ group (r=0.18, P=0.033). (3) AUC of the early diagnosis model constructed by combining BDNF, GDNF and HOMA-IR was 0.890 (95%CI: 0.832-0.940), the accuracy was 0.89, the sensitivity and specificity was 0.94 and 0.82, respectively. Conclusion: The final diagnostic model based on biomarkers of serum neurotrophic factor has good diagnostic efficiency for SCZ, but large-scale independent sample verification is still needed.

[Annual progress in pulmonary rehabilitation 2022]

Pulmonary rehabilitation can relieve dyspnea in patients, improve their healthy status and exercise tolerance. It is the most cost-effective comprehensive intervention. Although the role of pulmonary rehabilitation has been recognized and recommended in clinical guidelines, it is still underutilized worldwide. Therefore, how to improve the knowledge and awareness of pulmonary rehabilitation and to increase accessibility, thus promoting its application and completion, is the key point of clinical research. Related research has also made a series of important progress. This review summarized the latest research findings from September 2021 to October 2022, with the goal of increasing healthcare professionals' knowledge and awareness in order to improve patient referral to pulmonary rehabilitation.

[Long-term trend of colorectal cancer survival rate in Qidong, 1972-2016]

Objective: The survival of colorectal cancer in Qidong City, Jiangsu Province from 1972 to 2016 was analyzed to provide a basis for the evaluation of prognosis and the formulation of prevention and control measures. Methods: Colorectal cancer data were obtained from the Qidong Cancer Registration and Reporting System, and the follow-up was up to December 31, 2021. The observed survival rate (OSR) and relative survival rate (RSR) were calculated by SURV 3.01 software, and the trend test was performed by Hakulinen's likelihood ratio test. The Joinpoint regression model was used to calculate the average annual percentage change (AAPC) of survival, and the ARIMA model was used to predict the trend of colorectal cancer survival. Results: There were 8 637 new cases of colorectal cancer in Qidong from 1972 to 2016. Dividing 1972-2016 into 9 periods at 5-year intervals, the 5-year OSR from 1972-1976 to 2012-2016 increased from 21.86% to 48.86%, and the 5-year RSR increased from 26.45% to 59.91%. The increasing trend of RSR was statistically significant (χ(2)=587.47, P<0.001). From 1972 to 2016, the survival rates of colorectal cancer in different sexes in Qidong were similar, and the 5-year RSR was 44.63% for men and 44.07% for women. Since the 1990s, the 5-year OSR and RSR for men have been lower than those for women. From 1972 to 2016, the 5-year RSR of colorectal cancer in Qidong was significantly improved in the 65-74 and ≥75-year-old groups, but the survival rate of the ≥75-year-old group was still the lowest (36.78%), followed by the 35-44-year-old group ( 43.04%). The time trend showed that the overall AAPC of colorectal cancer 5-year RSR in Qidong from 1972 to 2016 was 2.50% (t=16.45, P<0.001). The upward trend of different sexes was consistent, and the increase was greater in women (AAPC for males=2.18%, AAPC for females=2.54%, both P<0.05). The 5-year RSR of colorectal cancer in each age group showed an upward trend, and the AAPCs of the 35-44, 45-54, 55-64, 65-74, and ≥75-year-old groups were 1.54%, 1.83%, 2.00%, 3.51% and 4.35%, respectively (all P<0.05). The prediction results of colorectal cancer survival rate showed that the 5-year RSR of colorectal cancer in Qidong will increase to 71.62% by 2026. Conclusions: The overall survival rate of colorectal cancer patients in Qidong has been greatly improved, but there is still room for improvement. We should continue to pay attention to the early diagnosis and early treatment of colorectal cancer.

[Long-term trend of gastric cancer survival rate in Qidong, 1972-2016]

Objective: The survival rate of gastric cancer cases in the whole population of Qidong City of Jiangsu Province from 1972 to 2016 was analyzed to provide a data basis for prevention and control of gastric cancer. Methods: The observed survival rate (OSR) was calculated by the life table method, the relative survival rate (RSR) was calculated by SURV 3.01 software, and the trend test was performed by Hakulinen's likelihood ratio test. Age-standardized relative survival rate (ARSR) was calculated using the International Cancer Survival Standard (ICSS). The Joinpoint regression model was used to calculate the average annual percentage change (AAPC) of survival rate, and the trend analysis of the overall survival rate of gastric cancer and the survival rates of different sexes and ages was conducted. The ARIMA model was used to predict the survival rate. Results: From 1972 to 2016, there were 18 067 new cases of gastric cancer in Qidong City. The OSRs at 1, 5, and 10 years were 37.12%, 17.16%, and 12.86%, respectively, and the RSRs at 1, 5, and 10 years were 38.83%, 21.73%, and 21.20%. Dividing 1972-2016 into 9 periods at 5-year intervals, compared with 1972-1976, the 5-year RSR in 2012-2016 increased from 12.53% to 36.26%, and the RSR in the 9 periods increased with statistical significance (χ(2)=747.19, P<0.001). Both OSR and RSR were slightly higher in men than in women, and decreased with age. The AAPC results showed that the AAPC of the 5-year RSR of gastric cancer in Qidong was 2.88%, 2.75% in males and 3.05% in females, and the upward trend was statistically significant (P<0.001). From 1972 to 2016, the 5-year RSR of gastric cancer in all age groups showed an upward trend. Except for the 35-44-year-old group (AAPC=1.07%, t=2.16, P=0.067), the age groups had statistical significance ( AAPC=2.59% in the 45-54-year-old group, AAPC=3.19% in the AAPCs of other 55-64-year-old group, AAPC=3.99% in the 65-74-year-old group, and AAPC=2.97% in the 75-year-old group, all P<0.05). The prediction results of the ARIMA model showed that in 2026, the 5-year OSR of gastric cancer in Qidong will increase to 39.82%, and the 5-year RSR will increase to 49.23%. Conclusion: The overall survival rate of registered gastric cancer cases in Qidong has been greatly improved, but there is still large room for improvement. More attention should be paid to the prevention and treatment of gastric cancer.

[Long-term trend of esophageal cancer survival rate in Qidong, 1972-2016]

Objective: To analyze the survival of esophageal cancer cases in Qidong, Jiangsu Province from 1972 to 2016, and provide a basis for the prognosis evaluation and prevention of esophageal cancer patients. Methods: The data of esophageal cancer were obtained from the Qidong Cancer Registration and Reporting System, and the follow-up date ended December 31, 2021. Observed survival rate (OSR) and relative survival rate (RSR) were calculated by SURV 3.01 software, and Hakulinen's likelihood ratio test was used for statistical difference comparison. Joinpoint regression model was used to conduct the average annual percentage change (AAPC) in esophageal cancer survival rate, and the ARIMA model was used to predict the trend of esophageal cancer survival rate. Results: During 1972 to 2016, there were 5 112 new cases of esophageal cancer in Qidong. The OSR of esophageal cancer at 1, 5 and 10 years were 24.43%, 6.93% and 4.43%, and the RSR at 1, 5 and 10 years were 25.88%, 9.35% and 8.34%, respectively. Dividing 1972-2016 into 9 periods, compared with 1972-1976, the 5-year RSR from 2012-2016 increased from 4.47% to 17.85%, and the RSR trend of the 9 periods was statistically significant (χ(2)=263.43, P<0.001). The survival rate of female with esophageal cancer was slightly higher than that of male, however, there was no significant difference in RSR between male and female (χ(2)=9.40, P=0.401). The 5-OSR and 5-RSR for male were 6.73% and 9.11%, and for female were 7.37% and 9.87%, respectively. The 5-RSR for the age groups of 45-54, 55-64, 65-74, and over 75 years old were 11.99%, 11.21%, 8.17% and 7.08%, respectively. There was a statistically significant difference in RSR among different age groups (χ(2)=98.19, P<0.001). The time trend results showed that the overall AAPC of the 5-RSR of esophageal cancer in Qidong from 1972 to 2016 was 3.89% (t=11.98, P<0.001). The 5-RSR uptrend was consistent among different genders, and the uptrend was greater in female (AAPC=4.25% for male, and AAPC=5.72% for female, P<0.05). Furthermore, the 5-RSR of esophageal cancer in all age groups showed an upward trend, and the upward trend was statistically significant in the 55-64-year-old group (AAPC=4.23%, P<0.05) and the 65-74-year-old group (AAPC=6.82%, P<0.05), there was no statistical significance in the 45-54-year-old group (AAPC=2.17%, P>0.05) and more than 75 years old group (AAPC=1.82%, P>0.05). Survival rate prediction of esophageal cancer showed that by 2026, 5-RSR will increase to 24.79%. Conclusions: During 1972 to 2016, the overall survival rate of esophageal cancer in the whole population of Qidong has improved to a certain extent, but there is still a large room for improvement. More emphasis should be continued to strengthen on the early diagnosis and early treatment of esophageal cancer.

[Epidemic characteristics of esophageal cancer mortality in Qidong, 1972-2016]

Objective: To describe the epidemic characteristics of esophageal cancer mortality in Qidong from 1972 to 2016, and to provide baseline for making control measures and strategies for prevention. Methods: The cancer registry data were collected and analyzed on mortality of oesophagus cancer during 1972-2016 in Qidong in different sex, age and time. Indices of statistics included crude mortality rate (CR), China age-standardized rate (CASR), world age-standardized rate (WASR), 35-64 years truncated rate, 0-74 years cumulative rate, cumulative risk, average annual percentage change (AAPC), mortality by period and mortality in the birth cohort. Results: A total of 4 795 esophageal cancer cases (male: 3 315, female: 1 480) died during the 45 years, accounting for 4.85% of all cancer deaths. The crude mortality was 9.48/10(5) (CASR: 3.62/10(5,) WASR: 6.30/10(5)) from 1972 to 2016. The crude mortality was significantly increased with age. In 2016, the crude mortality was 11.61/10(5) (CASR: 2.64/10(5,) WASR: 4.89/10(5)), respectively. The average annual percentage change (AAPC) were 0.99%、-2.03%、-1.72%. The mortalities of esophageal cancer in all age groups from 35 to 74 have been decreasing since the 1980s. The age-birth cohort analysis showed a decline in mortality rates in age groups from 40 to 79. Conclusions: The crude mortality rate of esophageal cancer increases slightly in Qidong, while the China age-standardized rate and world age-standardized rate decrease significantly. However, esophageal cancer is still one of the malignant tumors that affects the health of residents and seriously threatens the people's lives and health. The situation of cancer prevention and control is still serious in Qidong.

Utility of 3D printed models as adjunct in acetabular fracture teaching for Orthopaedic trainees

OBJECTIVE

To evaluate the use of 3-D printed models as compared to didactic lectures in the teaching of acetabular fractures for Orthopaedic trainees.

METHODS

This was a randomised prospective study conducted in a tertiary hospital setting which consisted of 16 Orthopaedic residents. Ten different cases of acetabular fracture patterns were identified and printed as 3-D models. The baseline knowledge of orthopaedic residents regarding acetabular fracture classification and surgical approach was determined by an x-ray based pre-test. Trainees were then randomly assigned into two groups. Group I received only lectures. Group II were additionally provided with 3-D printed models during the lecture. Participants were then assessed for comprehension and retention of teaching.

RESULTS

Sixteen trainees participated in the trial. Both Group 1 and 2 improved post teaching with a mean score of 2.5 and 1.9 to 4.4 and 6 out of 10 respectively. The post test score for fracture classification and surgical approach were significantly higher for 3-D model group (p < 0.05). Trainees felt that the physical characteristics of the 3-D models were a good representation of acetabular fracture configuration, and should be used routinely for teaching and surgical planning.

CONCLUSION

3-D printed model of real clinical cases have significant educational impact compared to lecture-based learning towards improving young trainees' understanding of complex acetabular fractures.

[Epidemic characteristics of stomach cancer mortality in Qidong during 1972-2016]

Objective: To describe the epidemic characteristics of stomach cancer mortality in Qidong between 1972 and 2016. Methods: The cancer registry data of stomach cancer death and population during 1972-2016 in Qidong was collected. The mortality of crude rate (CR), China age-standardized rate (CASR), world age-standardized rate (WASR), 35-64 years truncated rate, 0-74 years cumulative rate, cumulative risk, percentage change (PC), annual percent change (APC) were calculated. Results: During 1972-2016, a total of 15 863 (male: 10 114, female: 5 749) deaths occurred attributed to stomach cancer, accounting for 16.04% of all cancers, with CR of 31.37/100 000 (CASR: 12.97/100 000, WASR: 21.39/100 000). The truncated rate of 35-64, cumulative rate of 0-74, and cumulative risk were 28.86/100 000, 2.54%, and 2.51%, respectively. For male, the CR, CASR, WASR were 40.53/100 000, 17.98/100 000, 30.13/100 000, respectively, and for female, the CR, CASR, WASR were 22.45/100 000, 8.52/100 000, 13.92/100 000, respectively. Age-specific mortality analysis showed that the mortality of each age group under 25-year-old group was less than 1/100 000. The CR increased with age. The 50-year-old group reached and exceeded the average mortality of the population, and more than 80-year-old group reached the peak of death. During 1972-2016 in Qidong, The PCs in CR, CASR, and WASR of stomach cancer were 55.43%, -52.02%, -43.60%. The APC were 0.54%, -2.30%, -2.08%, respectively. Period mortality analysis showed that except for the 75-year-old group, the mortality of stomach cancer decreased significantly. Conclusions: The crude mortality of stomach cancer increases slightly in Qidong, while the CASR and WASR decrease significantly. However, stomach cancer is still one of the malignant tumors that most affect health and seriously threat lives.

[An analysis of mortality trends for upper gastrointestinal neoplasms in Qidong, 1972-2016]

Objective: To describe the trend of upper gastrointestinal cancer mortality in Qidong between 1972 and 2016, and to provide guidelines for prevention and control measures and strategies. Methods: The upper gastrointestinal data was collected in Qidong cancer registration from 1972 to 2016. Crude mortality rate (CR), China age-standardized rate (CASR), world age-standardized rate (WASR), truncated rate (35-64 years old), cumulative rate (0-74 years old) and cumulative risk were calculated. Annual percent change (APC) was calculated by Joinpoint software. Age-period-cohort model was used to analyze the influence of age, period and birth cohort on the changes in the mortality trend of upper gastrointestinal cancer patients. Results: From 1972 to 2016, there were 20 658 deaths of upper gastrointestinal cancer in Qidong, accounting for 20.89% of all cancer deaths. The CR, CASR, WASR, truncated rate (35-64 years old), cumulative rate (0-74 years old) and cumulative risk were 40.85/100 000, 27.96/100 000, 27.69/100 000, 36.01/100 000, 3.30% and 3.25%, respectively. There were 13 429 male deaths, the CR, CASR, and the WASR were 53.81/100 000, 37.62/100 000, and 39.93/100 000; the female deaths were 7 229, and the CR, CASR, and WASR were 28.23/100 000, 18.87/100 000, 17.25/100 000, respectively. The APCs of the 45-year-old, 55-year-old and 65-year-old age groups were -2.94% (95% CI: -3.32%, -2.56%), -2.94% (95% CI: -3.22%, -2.66%) and -2.04% (95% CI: -2.39%, -1.69%), with significant difference (P<0.05), while without significance of 75-year-old group (P>0.05). From 1972 to 2016, the APCs of CR, CASR, and WASR in the gastrointestinal cancer were 0.65% (95%CI: 0.43%, 0.87%), -2.01% (95%CI: -2.24%, -1.77%) and -2.05% (95%CI: -2.28%, -1.81%). The age-period-cohort model showed that the mortality of upper gastrointestinal cancer was increased with age (P<0.05). Conclusions: The crude mortality of upper gastrointestinal cancer increases slightly in Qidong, while the CASR and WASR decrease significantly. However, with aged tendency of population, the early diagnosis and treatment of upper gastrointestinal cancer is still needed to be paid attention.

[Clinical application of expanded noninvasive prenatal testing for fetal chromosome abnormalities]

To assess the positive predictive value (PPV) of extended noninvasive prenatal testing (NIPT-plus) for fetal chromosomal abnormalities. This retrospective research enrolled 511 cases of pregnant women with positive NIPT-plus results at the Obstetrics and Gynecology Hospital of Fudan University from May 2017 to January 2021. Karyotype analysis and chromosome microarray analysis (CMA) techniques was applied for verification. All cases were followed to determine their pregnancy outcome. The Chi-square test was used in PPV. 63 out of 511 refused prenatal diagnosis after counseling, 448 pregnant women with prenatal diagnosis showed that the PPVs of NIPT-plus test for fetal trisomy 21, 18 and 13 (T21, T18, T13), sex chromosome aneuploidy (SCAs) and chromosome microdeletion/microduplication syndrome (MMS) were 86.0% (92/107), 79.5% (35/44), 54.5% (12/22), 39.5% (75/190), and 41.7% (30/72), respectively. The results revealed that the PPV was higher among older pregnant women compared to young pregnant women (77.8% vs. 51.9%,P<0.01). With increasing maternal age, the PPV of NIPT-plus presented increasing trends for T21, T13, and composite PPV except for T18 or SCAs. In addition, the termination rates for confirmed SCAs fetal karyotypes 45, X; 47, XXX; 47, XXY and 47, XYY were 11/11, 3/15, 91.7% (22/24) and 1/14, respectively. NIPT-plus can safely and effectively detect fetal chromosomal abnormalities and can be extended to MMS screening, significantly reducing the proportion of interventional prenatal diagnoses, and those with positive screening still require further confirmation.

[Identification of Synthetic Cannabinoid New Psychoactive Substances 4F-MDMB-BUTINACA and MDMB-4en-PINACA]

Abstract

Objective To establish a method that combines a series of techniques including Fourier transform infrared spectrum （FTIR）, gas chromatography-mass spectrometry （GC-MS）, high resolution mass spectrometry and nuclear magnetic resonance spectroscopy （NMR） for identification of unknown substances. Methods The unknown samples （off-white powder and yellow crystal） seized in the actual cases were detected by FTIR, GC-MS （methanol as solvent）, high resolution mass spectrometry （methanol as solvent） and NMR （deuterated methanol as solvent）. Results The mass spectrum characteristic ions m/z of the main components in the samples measured by GC-MS were 219 （base peak）, 363, 307, 304, 275, 145, 131 and 213 （base peak）, 357, 301, 298, 269, 185, 171, 145 and 131, respectively. The accurate mass numbers [M+H]⁺ measured by high resolution mass spectrometry were 364.203 61 and 358.212 34, respectively. The unknown samples were identified as synthetic cannabinoid new psychoactive substances 4F-MDMB-BUTINACA and MDMB-4en-PINACA after data consultation and database retrieval and comparison, combined with infrared analysis and mass spectrometry data analysis, and their structures were confirmed by ¹H-NMR. Conclusion The established multi-technology joint identification method can be used to identify 4F-MDMB-BUTINACA and MDMB-4en-PINACA in unknown samples. This method is fast, convenient, accurate, reliable and practical, and can provide reference for the identification of cases involving such substances in the future.

[Gene analysis and clinical features of MYH9-related disease]

Objective: To identify gene variants and investigate clinical features of nonmuscle myosin heavy chain 9-related disease (MYH9-RD). Methods: In this retrospective study, the data of patients with MYH9-RD admitted to Shenzhen Children's Hospital from July 2017 to September 2020 were extracted. The gene variants, clinical features and laboratory tests results were summarized. Results: Among the 6 children, 4 were males and 2 were females, aged 4.0 (0.5-7.6) years. Main clinical manifestations included thrombocytopenia (6 cases), epistaxis (3 cases), petechias (2 cases), traumatic hematoma (1 case), and abnormal liver enzymes (1 case). One patient had no family history, and the other 5 cases were pedigrees. Two pedigrees (2 cases) had long-term microscopic hematuria, one pedigree (2 cases) had history of early cataract, and three pedigrees (5 cases) had chronic mild elevation of liver enzymes. Four MYH9 gene variants were found in 12 patients, including c.2104C>T(p.R702C) in exon 17, c.4270G>A(p.D1424N) in exon 31, c.5521G>A (p.E1841K) in exon 39, and c.5797C>T (p.R1933X) in exon 41. According to the family pedigrees analysis, except for the case of variant in exon 17 which was spontaneous mutation with no family history, the other variants were from their father or mother. The complete blood count results showed a decreased platelet number in these patients, and the counting results of the automated hematology analyzer were significantly lower than that of manual counting method ((33.4±17.2) × 10⁹ vs. (60.4±21.0) × 10⁹/L,t=-5.83, P<0.05). The examination of the peripheral blood smear revealed the presence of thrombocytopenia with giant platelets and granulocyte inclusion bodies. The MYH9 gene variant (R702C) located at the N-terminus head domain of non-muscle myosin heavy chain ⅡA (NMMHC-ⅡA), which has ATPase activity, led to severe reduction of platelet number (<20×10⁹/L) and obscure granulocyte inclusion bodies. However, higher platelet numbers (40×10⁹-80×10⁹/L) and obvious granulocyte inclusion bodies were observed in patients with tail-position mutations at C-terminus. Conclusions: The clinical phenotypes of MYH9-RD were variable. The mutations in certain regions of MYH9 gene were related to platelet count and granulocyte inclusion bodies. MYH9-RD should be considered in individuals with unknown etiology and persistent thrombocytopenia which is non-responsive to conventional treatment, regardless of family history. Complete blood count and blood smear morphology examinations are the first steps to screen and diagnose the disease. The laboratory should pay attention to the morphological review rules and standardized reports.

[Consistency of peripheral whole blood and venous serum procalcitonin in children: a multicenter parallel controlled study]

Objective: To explore the consistency of peripheral whole blood and venous serum procalcitonin (PCT) levels, and the value of peripheral whole blood PCT in evaluating pediatric bacterial infection. Methods: This multicenter cross-sectional parallel control study was conducted in 11 children's hospital. All the 1 898 patients older than 28 days admitted to these hospitals from March 2018 to February 2019 had their peripheral whole blood and venous serum PCT detected simultaneously with unified equipment, reagent and method. According to the venous serum PCT level, the patients were stratified to subgroups. Analysis of variance and chi-square test were used to compare the demographic characteristics among groups. And the correlation between the peripheral blood and venous serum PCT level was investigated by quantitative Pearson correlation analysis.The PCT resultes were also converted into ranked data to further test the consistency between the two sampling methods by Spearman's rank correlation test. Furthermore, the ranked data were converted into binary data to evaluate the consistency and investigate the best cut-off of peripheral blood PCT level in predicting bacterial infection. Results: A total of 1 898 valid samples were included (1 098 males, 800 females),age 27.4(12.2,56.7) months. There was a good correlation between PCT values of peripheral whole blood and venous serum (r=0.97, P<0.01). The linear regression equation was PCT_{venous serum}=0.135+0.929×PCT_{peripheral whole blood}. However, when stratified to 5 levels, PCT results showed diverse and unsatisfied consistency between the two sampling methods (r=0.51-0.92, all P<0.01). But after PCT was converted to ordinal categorical variables, the stratified analysis showed that the coincidence rate of the measured values by the two sampling methods in each boundary area was 84.9%-97.1%. The dichotomous variables also showed a good consistency (coincidence rate 96.8%-99.3%, Youden index 0.82-0.89). According to the severity of disease, the serum PCT value was classified into 4 intervals（<0.5、0.5-<2.0、2.0-<10.0、≥10.0 μg/L）, and the peripheral blood PCT value also showed a good predictive value (AUC value was 0.991 2-0.997 9). The optimal cut points of peripheral whole blood PCT value 0.5、1.0、2.0、10.0 μg/L corresponding to venous serum PCT values were 0.395, 0.595, 1.175 and 3.545 μg/L, respectively. Conclusions: There is a good correlation between peripheral whole blood PCT value and the venous serum PCT value, which means that the peripheral whole blood PCT could facilitate the identification of infection and clinical severity. Besides, the sampling of peripheral whole blood is simple and easy to repeat.

Insight into intrinsic ferromagnetism in quasi-2D Cr5-yTe8

Cr₅Te₈is a half metal with 2D van der Waals ferromagnetic structure and its magnetic properties can be tuned by changing the proportionality of Cr and Te. We report an investigation of magnetization and magnetic anisotropy near the critical transition region of a Cr_5-yTe₈single crystal with the static and dynamic probes, to unravel the nature of field-dependent spin-spin interactions. The magnetic transition temperatureT_Cincreasing from 255 K (at near zero-field) to 279 K (at 65 kOe along theab-plane) has been identified. Accordingly, a phase diagram of field versus transition temperature has been established. From the analysis of the field dependence of the critical behavior, we provided evidence that the scenario of 2D Heisenberg-type interactions can be employed to interpret the field-dependent magnetic transitions in Te-rich Cr_4.8Te₈. The precise picture for the field-reduced spin-spin interaction range has been obtained. The conclusion drawn from the present study demonstrated that Cr_4.8Te₈is a promising candidate for the spintronic applications with a tunable magnetic transition temperature.

Effect of congenital heart disease on the recurrence of cough variant asthma in children

Background

The research into the recurrence of cough variant asthma (CVA) in congenital heart disease (CHD) are few in number. The purpose of this study is to investigate the effect of CHD on the risk of the recurrence of CVA.

Methods

This study was a retrospective cohort study of 489 children with CVA aged between one and 14 years, of whom 67 had CHD complicated with CVA and 134 had CVA without CHD at a ratio of 1:2 according to age, sex and index year. The adjusted hazard ratio (aHR) of CVA recurrence in both the CHD cohort and the non-CHD cohort was determined by multivariate analysis using the Cox proportional hazard regression model.

Results

Adjusting for CHD classification, Mycoplasma pneumonia (MP) infection and immunoglobulin E (IgE) sensitization, the recurrence hazard of CVA in the complex congenital heart disease (CCHD) group (aHR = 3.281; 95% CI 1.648–6.530; P < 0.01) was significantly higher than that in the simple congenital heart disease group (aHR = 2.555; 95% CI 1.739–3.752; P < 0.01). Further, children with IgE sensitization (aHR = 2.172; 95% CI 1.482–3.184; P < 0.01) had a higher recurrence hazard of CVA than those without IgE sensitization, and children with MP infection (aHR = 1.777; 95% CI 1.188–2.657; P < 0.01) had a higher recurrence hazard of CVA than those without the MP infection.

Conclusion

The hazard of recurrent CVA is higher in children with CHD, especially in the CCHD children. In addition, those children with IgE sensitization or a MP infection had an increased hazard of recurrent CVA.

[An analysis of mortality trends for lung cancer during 1972-2016 in Qidong city of Jiangsu Province]

Crude mortality rate (CR) for lung cancer in Qidong increased from 11.50/10⁵ in 1972-1976 to 76.61/10⁵ in 2012-2016, China age-standardized rate (CASR) from 13.11/10⁵ in 1972-1976 to 34.27/10⁵ in 2012-2016, and World age-standardized rate (WASR) from 13.40/10⁵ in 1972-1976 to 34.30/10⁵ in 2012-2016. The average annual percentage change (AAPCs) of CR, CASR, WASR were 4.87% (95%CI: 4.63%-5.12%), 2.17% (95%CI: 1.96%-2.38%), 2.12% (95%CI: 1.92%-2.33%) (all P values<0.001), respectively. AAPCs for 45-54, 55-64, 65-74 and over 75 age groups were 0.74% (95%CI: 0.36%-1.11%), 1.23% (95%CI: 0.92%-1.53%), 2.55% (95%CI: 2.20%-2.90%), 4.26% (95%CI: 3.56%-4.96%) (all P values<0.001), respectively.

A novel model for predicting fatty liver disease by means of an artificial neural network

Background

The artificial neural network (ANN) emerged recently as a potent diagnostic tool, especially for complicated systemic diseases. This study aimed to establish a diagnostic model for the recognition of fatty liver disease (FLD) by virtue of the ANN.

Methods

A total of 7,396 pairs of gender- and age-matched subjects who underwent health check-ups at the First Affiliated Hospital, College of Medicine, Zhejiang University (Hangzhou, China) were enrolled to establish the ANN model. Indices available in health check-up reports were utilized as potential input variables. The performance of our model was evaluated through a receiver-operating characteristic (ROC) curve analysis. Other outcome measures included diagnostic accuracy, sensitivity, specificity, Cohen's k coefficient, Brier score, and Hosmer-Lemeshow test. The Fatty Liver Index (FLI) and the Hepatic Steatosis Index (HSI), retrained using our training-group data with its original designated input variables, were used as comparisons in the capability of FLD diagnosis.

Results

Eight variables (age, gender, body mass index, alanine aminotransferase, aspartate aminotransferase, uric acid, total triglyceride, and fasting plasma glucose) were eventually adopted as input nodes of the ANN model. By applying a cut-off point of 0.51, the area under ROC curves of our ANN model in predicting FLD in the testing group was 0.908 [95% confidence interval (CI), 0.901-0.915]-significantly higher (P < 0.05) than that of the FLI model (0.881, 95% CI, 0.872-0.891) and that of the HSI model (0.885; 95% CI, 0.877-0.893). Our ANN model exhibited higher diagnostic accuracy, better concordance with ultrasonography results, and superior capability of calibration than the FLI model and the HSI model.

Conclusions

Our ANN system showed good capability in the diagnosis of FLD. It is anticipated that our ANN model will be of both clinical and epidemiological use in the future.

[Health economic evidence for colorectal cancer screening programs in China: an update from 2009-2018]

Objective: This study was to systematically update the economic evaluation evidence of colorectal cancer screening in mainland China. Methods: Based on a systematic review published in 2015, we expanded the scope of retrieval database (PubMed, EMbase, The Cochrane Library, Web of Science, CNKI, Wanfang Data, VIP, CBM) and extended it to December 2018. Focusing on the evidence for nearly 10 years (2009-2018), basic characteristics and main results were extracted. Costs were discounted to 2017 using the consumer price index of medical and health care being provided to the residents, and the ratio of incremental cost-effectiveness ratio (ICER) to per capita GDP in corresponding years were calculated. Results: A total of 12 articles (8 new ones) were included, of which 9 were population-based (all cross-sectional studies) and 3 were model-based. Most of the initial screening age was 40 years (7 articles), and most of the frequency was once in a lifetime (11 articles). Technologies used for primary screening included: questionnaire assessment, immunological fecal occult blood test (iFOBT) and endoscopy. The most commonly used indicator was the cost per colorectal cancer detected, and the median (range) of the 20 screening schemes was 52 307 Chinese Yuan (12 967-3 769 801, n=20). The cost per adenoma detected was 9 220 Yuan (1 859-40 535, n=10). In 3 articles, the cost per life year saved (compared with noscreening) was mentioned and the ratio of ICER to GDP was 0.673 (-0.013-2.459, n=11), which was considered by WHO as "very cost-effective" ; The range of ratios overlapped greatly among different technologies and screening frequencies, but the initial age for screening seemed more cost-effective at the age of 50 years (0.002, -0.013-0.015, n=3), than at the 40 year-olds (0.781, 0.321-2.459, n=8). Conclusions: Results from the population-based studies showed that the cost per adenoma detected was only 1/6 of the cost per colorectal cancer detected, and limited ICER evidence suggested that screening for colorectal cancer was generally cost-effective in Chinese population. Despite the inconclusiveness of the optimal screening technology, the findings suggested that the initial screening might be more cost-effective at older age. No high-level evidence such as randomized controlled trial evaluation was found.

Analysis of an improved workflow of endoscope reprocessing for bedside endoscopic diagnosis and treatment on COVID-19 patients. J Zhejiang Univ Sci B 2020;21:416-422. [PMID: 32425010 PMCID: PMC7210095 DOI: 10.1631/jzus.b2000109]

Severe cases infected with the coronavirus disease 2019 (COVID-19), named by the World Health Organization (WHO) on Feb. 11, 2020, tend to present a hypercatabolic state because of severe systemic consumption, and are susceptible to stress ulcers and even life-threatening gastrointestinal bleeding. Endoscopic diagnosis and treatment constitute an irreplaceable part in the handling of severe COVID-19 cases. Endoscopes, as reusable precision instruments with complicated structures, require more techniques than other medical devices in cleaning, disinfection, sterilization, and other reprocessing procedures. From 2016 to 2019, health care-acquired infection caused by improper endoscope reprocessing has always been among the top 5 on the list of top 10 health technology hazards issued by the Emergency Care Research Institute. Considering the highly infective nature of COVID-19 and the potential aerosol contamination therefrom, it is of pivotal significance to ensure that endoscopes are strictly reprocessed between uses. In accordance with the national standard “Regulation for Cleaning and Disinfection Technique of Flexible Endoscope (WS507-2016),” we improved the workflow of endoscope reprocessing including the selection of chemicals in an effort to ensure quality control throughout the clinical management towards COVID-19 patients. Based on the experience we attained from the 12 severe COVID-19 cases in our hospital who underwent endoscopy 23 times in total, the article provides an improved version of endoscopic reprocessing guidelines for bedside endoscopic diagnosis and treatment on COVID-19 patients for reference.

Identification of the New Psychoactive Substance Dibutylone

Abstract

Objective To establish a method to identify unknown samples based on combined use of gas chromatography-mass spectrometry （GC-MS）, high resolution mass spectrometry （HRMS） and nuclear magnetic resonance spectrum （NMR） technique. Methods The unknown samples were dissolved in methanol solution containing internal standard SKF525A and detected by GC-MS and HRMS. The mixed samples were separated and purified by silica gel column chromatography, and then dissolved in methanol-d4 solution for structural analysis of ¹H nuclear magnetic resonance spectroscopy （¹H NMR）. Results The characteristic fragment ions （m/z） were 86.1 （base peak）, 71.2, 121.1, and 149.0, and the accurate mass number of molecular ion peak was measured by HRMS to be 236.128 89. By combined use of data analysis and database comparison, a new psychoactive substance of the cathinone class, Dibutylone, was detected in the sample, and the sample also contained a small amount of caffeine. The sample was purified, then identified using ¹H NMR, and was further confirmed to be Dibutylone. In addition, the GC-MS retention time and characteristic fragment ions of the main components of the sample were consistent with those of Dibutylone reference material. Conclusion The method established in this study can be used for the identification of Dibutylone in mixed samples.

[Study on the health literacy and related factors of the cancer prevention consciousness among urban residents in China from 2015 to 2017]

Objective: To understand the health literacy and relevant factors of cancer prevention consciousness in Chinese urban residents from 2015 to 2017. Methods: A cross-sectional survey was conducted in 16 provinces covered by the Cancer Screening Program in Urban China from 2015 to 2017. A total of 32 257 local residents aged ≥18 years old who could understand the investigation procedure were included in the study by using the cluster sampling method and convenient sampling method. All local residents were categorized into four groups, which contained 15 524 community residents, 8 016 cancer risk assessment/screening population, 2 289 cancer patients and 6 428 occupational population, respectively. The self-designed questionnaire was used to collect the information of demographic characteristics and cancer prevention consciousness focusing on nine common risk factors, including smoking, alcohol, fiber food, food in hot temperature or pickled food, chewing betel nut, helicobacter pylori, moldy food, hepatitis B infection, estrogen, and exercise. The logistic regression model was adopted to identify the influencing factors. Results: The overall health literacy of the cancer prevention consciousness was 77.4% (24 980 participants), with 77.4% (12 018 participants), 79.9% (6 406 participants), 77.2% (1 766 participants) and 74.5% (4 709 participants) in each group (P<0.001). The correct response rates for nine risk factors ranged from 55.2% to 93.0%. The multivariate logistic regression analysis showed that compared with community residents, people with primary school level education or below, and the number of people living together in the family <3, the cancer risk assessment/screening intervention population, cancer patients, those with junior high school level educationor above and the number of people living in the family ≥3 had better health literacy of the cancer prevention consciousness (all P values <0.05). Compared with females, 39 years old and below, government-affiliated institutions or civil servants, from the eastern region, males, older than 40 years, company or enterprise employees, and from the middle or western region had worse health literacy of the cancer prevention consciousness (all P values <0.05). Conclusion: The health literacy of the cancer prevention consciousness in Chinese urban residents should be improved. The cancer screening intervention, gender, age, education, occupation, the number of people co-living in the family, and residential region were associated with the health literacy of the cancer prevention consciousness.

Association between Serum Uric Acid to HDL-Cholesterol Ratio and Nonalcoholic Fatty Liver Disease in Lean Chinese Adults

METHODS

A cross-sectional study was performed among 6285 lean Chinese adults (body mass index < 24 kg/m²) who took their annual health checkups. NAFLD was diagnosed based on hepatic ultrasound examination, with exclusion of other etiologies.

RESULTS

Of 6285 lean participants enrolled, 654 NAFLD cases were diagnosed. The overall NAFLD prevalence was 10.41%, and the prevalence was 15.45% and 7.16% in men and women, respectively. UHR was significantly higher in NAFLD patients than in controls (14.25 ± 5.33% versus 10.09 ± 4.23%, P < 0.001). UHR quintiles were positively associated with NAFLD prevalence, which was 1.91% in the first UHR quintile and increased to 3.58%, 7.81%, 14.17%, and 24.54% in the second, third, fourth, and fifth quintile groups, respectively (P < 0.001 for trend). Multivariate logistic regression analysis showed that UHR was independently associated with an increased risk of NAFLD (odds ratio: 1.105; 95% CI: 1.076-1.134; P < 0.001). Sensitivity analysis showed that UHR remained significantly associated with NAFLD in lean participants with normal range of serum uric acid and HDL-cholesterol levels.

CONCLUSIONS

UHR was significantly associated with NAFLD and may serve as a novel and reliable marker for NAFLD in lean adults.

P38 Developing a model for predicting in-hospital death in patients with the use of extracorporeal membrane oxygenation

Funding Acknowledgements

Minister of Science and Technology

Background

The objective of this study was to develop a predicting model for estimating the odds of in-hospital death in the patients who receive extracorporeal membrane oxygenation (ECMO).

Methods

Adult patients who received ECMO for a variety of etiologies in our National University Hospital from 2005 and 2016 were included. The demographic, anthropometric, hemodynamic, and laboratory data when ECMO was instituted were recorded for each individual. A logistic regression model was applied to find the risk variables that were independently associated with in-hospital mortality. The predicted probability derived from the model was used to plot a receiver-operating-characteristic (ROC) curve, and area under curve (AUC) was found to represent the differentiating capacity of this approach.

Results

A total of 919 patients (659 men and 260 women) were included in the analysis. The mean age was 53.7[SD 15.9] years. The analysis showed that age (odds ratio [OR]: 1.018, 95% confidence interval [CI]: 1.008-1.028 per year), blood urea nitrogen (1.008 [1.001-1.014] per mg/dL), use of inotropic agent in terms of inotropic equivalent (1.007 [1.002-1.013]), the presence of cardiogenic shock (1.910 [1.097-3.327]), and the need of hemodialysis (2.262 [1.304-3.926]) were positively associated with mortality. In addition, body surface area (OR: 0.414 [0.204-0.840] per square meter), systolic blood pressure (0.995 [0.990-0.999] per mmHg), Glasgow Coma Scale (0.928 [0.899-0.957] per unit), pH value (0.395 [0.158-0.988] for each unit), and urine output (OR: 0.974 [0.964-0.985] per dL) were negatively associated with the probability of in-hospital death. The AUC in ROC analysis was 0.754 (95% CI: 0.722-0.787).

Conclusion

The predicting model that used a simple set of physiological parameters could substantially discriminate whether the patients receiving ECMO could survive the in-hospital course. Further studies are needed to examine why false positive and false negative predictions took place.

Abstract P38 Figure.

[Association of glycosylated hemoglobin level at admission with outcomes of intracerebral hemorrhage patients]

Objective: To explore the association of the glycosylated hemoglobin (HbA1c) level at admission with 90 days functional outcome in patients with spontaneous intracerebral hemorrhage (ICH). Methods: Patients admitted to the Department of Neurology, Tongji Hospital from January to December 2017 were prospectively and continuously enrolled in this study. Clinical data were collected at admission and functional outcomes 90 days after ICH were assessed by using the modified RANKIN scale. Univariate and multivariate conditional logistic regression models were constructed. Patients were divided into four groups according to the quartile of HbA1c values. The median value of HbA1c in each group was taken as the substitute value and P for trend was calculated. The logistic regression model was fitted by restricted cubic splines to investigate the association between HbA1c level and outcome of ICH. Results: A total of 345 patients with ICH were enrolled, including 214 with favorable outcomes and 131 with poor outcomes (99 severe disability cases and 32 deaths). The risk of poor 90 days outcomes was significantly associated with HbA1c level at admission indicated by multivariate logistic regression analysis, and the P for trend test was <0.001 (middle-level group vs. low-level group: OR=2.33, 95%CI: 1.07-5.07; high-level group vs. low-level group: OR=2.52, 95%CI: 1.12-5.64; extremely high-level group vs. low-level group: OR=6.80, 95%CI: 3.01-15.34). Results from the restricted cubic spline showed that there was a linear correlation between HbA1c level at admission and poor 90 days outcomes of ICH (χ(2)=14.81, P<0.001; non- linear test: P=0.118). Compared with patients with HbA1c level of 6.5%, the risk of poor outcomes in patients with HbA1c level of <6.5% decreased linearly with the decrease in HbA1c level at admission, and the risk in patients with HbA1c level >6.5% was higher but not significantly. Conclusion: There was correlation between high HbA1c level at admission and 90 days poor outcome of ICH. High HbA1c level is an independent prediction indicator for ICH.

Singlet exciton fission via an intermolecular charge transfer state in coevaporated pentacene-perfluoropentacene thin films

Singlet exciton fission is a spin-allowed process in organic semiconductors by which one absorbed photon generates two triplet excitons. Theory predicts that singlet fission is mediated by intermolecular charge-transfer states in solid-state materials with appropriate singlet-triplet energy spacing, but direct evidence for the involvement of such states in the process has not been provided yet. Here, we report on the observation of subpicosecond singlet fission in mixed films of pentacene and perfluoropentacene. By combining transient spectroscopy measurements to nonadiabatic quantum-dynamics simulations, we show that direct excitation in the charge-transfer absorption band of the mixed films leads to the formation of triplet excitons, unambiguously proving that they act as intermediate states in the fission process.

Preparation of Immunotherapy Liposomal-Loaded Thermal-Responsive Hydrogel Carrier in the Local Treatment of Breast Cancer

To reduce the side effects of immune drugs and the sustainable release of immune drugs on local parts, we have designed an injectable thermal-sensitive hydrogel containing an imiquimod-loaded liposome system. In the extracellular environment of tumor tissues (pH 6.4), 50% of the drug was released from the carrier, which could be a result of the morphological changes of the liposomal microstructure in the acidic environment. According to the results in animals, the drug-containing liposomes combined with hydrogel can be effectively applied in breast cancer therapy to delay the growth of tumors as well as to dramatically reduce the death rate of mice.

[Screening function enrichment and related signaling pathways bioinformatics analysis of differentially expressed gene in glioma]

Objective: To screen the differentially expressed genes, functional enrichment and related signaling pathways in glioma by bioinformatics analysis. Methods: Microarray data of glioma related gene expression profiles were selected in GEO database, and differentially expressed genes in glioma patients and normal brain tissues were screened by R statistical software of lima package. Functional enrichment of differentially expressed genes (GO and KEGG) was performed. The protein-protein interaction database (STRING) was used to analyze the interaction between the screened differentially expressed genes and the related signaling pathways. Results: Two gene expression profiles, GSE15824 and GSE66354, were selected for analysis, and 158 genes with differential expression more than 2 times and P<0.05 were screened. Molecular function (MF) of 158 differentially expressed genes was integrin binding, cell adhesion molecule binding, calcium binding and AMPA glutamate receptor activity. Cell component localization (CC) was located in cell membrane, neuron cell body, axon of nerve cell and so on, while biological process (BP) was mainly cell adhesion and nervous system. Development, cell proliferation, GTPase activity, apoptosis and angiogenesis; KEGG signaling pathways were mainly cAMP signaling pathway, purine metabolism pathway, MAPK signaling pathway and cGMP-PKG signaling pathway. There were 177 interaction connections in 158 differential expression gene-protein interaction networks, with an average interaction of 2.39 between each node and an aggregation coefficient of 0.37. Cytohubb screened the key genes (hub genes) in the signaling pathway. The results indicated that SLC6A1,SLC1A2,BDNF,GAP43,NRXN1,GAD1,OLIG2, PLP1,S100B and GRIA3 were the key genes in the signaling pathway of the interacting protein network. All the 10 key genes were related to the prognosis of patients (P<0.05). Conclusions: There are differentially expressed genes profile in glioma tissues and normal tissues. SLC6A1, SLC1A2, BDNF, GAP43, NRXN1, GAD1, OLIG2, PLP1, S100B and GRIA3 are key genes for glioma development and are related to the prognosis of patients.

[Etiological analysis and establishment of a discriminant model for lower respiratory tract infections in hospitalized patients]

Objective: To analyze the pathogens of lower respiratory tract infection(LRTI) including bacterial, viral and mixed infection, and to establish a discriminant model based on clinical features in order to predict the pathogens. Methods: A total of 243 hospitalized patients with lower respiratory tract infections were enrolled in Fujian Provincial Hospital from April 2012 to September 2015. The clinical data and airway (sputum and/or bronchoalveolar lavage) samples were collected. Microbes were identified by traditional culture (for bacteria), loop-mediated isothermal amplification(LAMP) and gene sequencing (for bacteria and atypical pathogen), or Real-time quantitative polymerase chain reaction (Real-time PCR)for viruses. Finally, a discriminant model was established by using the discriminant analysis methods to help to predict bacterial, viral and mixed infections. Results: Pathogens were detected in 53.9% (131/243) of the 243 cases.Bacteria accounted for 23.5%(57/243, of which 17 cases with the virus, 1 case with Mycoplasma pneumoniae and virus), mainly Pseudomonas Aeruginosa and Klebsiella Pneumonia. Atypical pathogens for 4.9% (12/243, of which 3 cases with the virus, 1 case of bacteria and viruses), all were mycoplasma pneumonia. Viruses for 34.6% (84/243, of which 17 cases of bacteria, 3 cases with Mycoplasma pneumoniae, 1 case with Mycoplasma pneumoniae and bacteria) of the cases, mainly Influenza A virus and Human Cytomegalovirus, and other virus like adenovirus, human parainfluenza virus, respiratory syncytial virus, human metapneumovirus, human boca virus were also detected fewly. Seven parameters including mental status, using antibiotics prior to admission, complications, abnormal breath sounds, neutrophil alkaline phosphatase (NAP) score, pneumonia severity index (PSI) score and CRUB-65 score were enrolled after univariate analysis, and discriminant analysis was used to establish the discriminant model by applying the identified pathogens as the dependent variable. The total positive predictive value was 64.7%(77/119), with 66.7% for bacterial infection, 78.0% for viral infection and 33.3% for the mixed infection. Conclusions: The mostly detected pathogens were Pseudomonas aeruginosa, atypitcal pathogens, Klebsiella pneumoniae, influenza A virus and human cytomegalovirus in hospitalized patients with LRTI in this hospital. The discriminant diagnostic model established by clinical features may contribute to predict the pathogens of LRTI.

[Application of cervical lifting suture in hemostasis of placenta previa with increta and percreta]

Objective: To evaluate the effect of cervical lifting suture in treatment of placenta previa with increta and percreta. Methods: From January 2016 to June 2017, 65 cases (0.78%, 65/8 322) were diagnosed placenta previa with increta and percreta by prenatal ultrasonic score system and confirmed by intraoperative findings in the department of obstetrics and gynecology of Peking University Third Hospital. Totally 62 cases (0.75%, 62/8 322) were included, because 3 cases underwent hysterectomy with placenta in situ. According to ultrasonic score system, 62 cases were divided into two groups, score 5-9 group (n=42, 67.7%) and score≥10 group (n=20, 32.3%) , cervical lifting suture techniques were all performed in cesarean sections. Demographic and clinical data were collected and compared. Results: (1) There were no significant differences between two groups in age, gravidity, parity, cesarean section history ratio and gestational week of termination (all P>0.05) . (2) In score≥10 group, the median intraoperative bleeding volume was 4 000 ml (1 200-13 000 ml) , while in score 5-9 group, it was 1 600 ml (700-10 000 ml) , intraoperative blood transfusion volume was 2 000 ml (800-8 800 ml) in score≥10 group, while 1 200 ml (0-8 000 ml) in score 5-9 group. The median operation time was 240 minutes (108-1 200 minutes) in score≥10 group, significantly higher than that in score 5-9 group, which was 135 minutes (69-335 minutes; all P< 0.05). In 8 cases for hysterectomy (12.9%,8/62) , 3 cases in score 5-9 group, 5 cases in score≥10 group. (3) In score≥10 group, the rate of postoperative ICU registration was 80% and mean hospitalization time was (6.3±1.7) days, were significantly different, compared with those in score 5-9 group, which were 26%, (4.9±1.9) days. No serious postpartum complications were found in both groups, and there were no significant differences in Apgar score and weight of newborns (all P>0.05) . Conclusion: Cervical lifting suture in placenta previa with increta and percreta could significantly reduce postpartum hemorrhage and retain uterine.

[Early diagnosis and early treatment for liver cancer in Qidong: survival of patients and effectiveness of screening]

Objective: To evaluate the patients' survival and effectiveness of the live cancer screening for population at high risk for liver cancer in Qidong. Methods: According to the Expert Scheme proposed the Expert Committee of Early Detection and Early Treatment, China Cancer Foundation, diagnostical screening by using combined methods of alpha-fetoprotein and B ultrasound monitoring were carried out biannually in individuals with positive HBsAg who were screened from Qidong area. The evaluation indices of the effectiveness are task completion rate of screening, detection rate of liver cancer, early diagnosis rate, and treatment rate. The deadline of the follow-up for the surviving outcome was March 31, 2016. The life-table method was used to calculate the observed survival, and to make comparison and significant tests between survival rates in Group A (those found via repeated periodic screening) and Group B (those diagnosed without periodic screening). Results: Since 2007, 38 016 target population have been screened, and 3 703(9.74%) individuals with positive HBsAg were found. Except for 29 patients with liver cancer at the initial screening, 3 674 persons in the cohort were followed up; 268 patients with liver cancer were detected from the 33 199 person-times screening, with an annual detection rate of 1.61%. Of them, 186 patients were found in Group A(1.12%), in which 149 patients were the early cases, with an early detection rate of 80.11%; 167 out of 186(89.78%) patients received treatment after diagnosis. The incidence of liver cancer in this HBsAg (+ ) cohort of 25 452 person-years was 1 052.96 per 100 000 annually, 187 cases in males(1 488.45/100 000)and 81 cases in females(628.46/100 000). The 1-, 3-, 5-, and 8-year survival of all patients with liver cancer were 64.55%, 40.50%, 32.54%, and 19.65%, respectively. The 1-, 3-, 5-, and 8-year survival rates were 77.16%, 49.04%, 38.53%, and 24.25% in Group A, and were 36.25%, 21.21%, 21.21%, and 0% in Group B, respectively, with significant differences between two groups (P<0.05). Conclusion: The findings show that screening of individuals at high-risk of development of liver cancer, with semiannual AFP and B ultrasound, according to the Expert Scheme, is effective not only in increasing detection rate but also in detecting liver cancer at early stage, and in improving patients' survival as well.

[Research advances in nonalcoholic fatty liver disease and alcoholic liver disease in 2016]

Nonalcoholic fatty liver disease (NAFLD) has become the most important liver disease in the world and its prevalence rate still tends to increase. However, there are still no effective drugs so far. The complex and dynamic interactions between multiple effects/mediators in the pathophysiology of NAFLD provide new insights and help with stratification and redefinition of clinical phenotypes and evaluation of disease susceptibility and multiplicity of progression. They may also provide new targets for future treatment. Therefore, research on the pathophysiology of NAFLD is imperative. Alcoholic liver disease is a great harm to health and an important cause of end-stage liver disease. Some progress has been made in the research on alcoholic liver disease around the world in 2016. This article reviews the research advances in alcoholic liver disease in 2016 from the aspects of epidemiology, pathogenesis, diagnostic and therapeutic methods, and prognosis.

[Expression of serum interleukin-13 and significance of gene polymorphism on the patients with bronchiectasis in acute exacerbation period]

Objective: To explore the expression of serum interleukin-13 (IL-13) and significance of its gene polymorphism on the patients with acute exacerbation of bronchiectasis in acute exacerbation period. Methods: Forty-three patients with bronchiectasis in acute exacerbation period admitted into the respiratory ward of Fujian Provincial Hospital from December, 2014 to March, 2016 were included as bronchiectasis group. Thirty-three healthy controls from normal people of health examination were included as control group during the corresponding period. A total of 5 ml fasting peripheral blood sample was extracted from each individual. The IL-13 levels were determined by enzyme-linked immunosorbent assay (ELISA). IL-13 gene polymorphisms in+ 1923 C/T site and+ 2044 site were genotyped in these two groups by using polymerase chain reaction (PCR) combined with gene sequencing methods. About 7 days after admission, thirty patients with improved condition among the 43 patients were included as bronchiectasis improvement group, all had the extraction of 3 ml peripheral blood for IL-13 detection determined by ELISA. The expression of serum IL-13 and gene polymorphisms between bronchiectasis group and control group were analyzed statistically. The changes of serum IL-13 between bronchiectasis group and bronchiectasis improvement group were also analyzed statistically. Results: The serum IL-13 level was lower in the bronchiectasis group in acute exacerbation period than that of the healthy controls [(31.1±26.3) vs (70.6±53.6) μg/L, P<0.05]. There was no significant difference of the genotype distribution in + 1923C/T site of IL-13 gene between the two groups (χ(2)=0.915, P>0.05). In the bronchiectasis group, the C and T allele frequencies at+ 1923 site of IL-13 gene were 79.1% and 20.9%, respectively, and its single nucleotide polymorphism (SNP) was in strong linkage disequilibrium with the SNP IL-13+ 2044G/A site (R(2)=0.835, P<0.001). There was no significant difference of the serum IL-13 between allele T_ groups and allele CC group, and also no significant difference between allele A_ groups and allele GG group (P>0.05). Conclusion: The IL-13 levels decreased specifically in the bronchiectasis group in acute exacerbation period, but IL-13+ 1923C/T and+ 2044G/A polymorphisms are not significantly related to the susceptibility of bronchiectasis.

Metastasis-associated gene 1 expression in human medulloblastoma and its association with invasion and metastasis in medulloblastoma Daoy cell lines

This study aims to investigate the expression of metastasis-associated gene 1 (MTA1) in human medulloblastoma, and its significance in the invasion and metastasis in a medulloblastoma cell line. Positive expression rate of MTA1 protein in medulloblastoma and adjacent normal tissues collected from 29 medulloblastoma patients was detected by immunohistochemistry assay in vivo. In in vitro experiments, Daoy cells were transfected with MTA1-targeted small interfering RNA (siRNA, MTA1-siRNA group), niRNA (MTA1-niRNA group), and plasmid vectors (control group). Transfection efficiency was evaluated by PT-PCR and western blot; cell adhesion, migration, and invasion capacity was assessed by adhesion assays, scratch assays, and transwell chamber invasion assays, respectively. Results indicated that the positive expression rate of MTA1 protein in the medulloblastoma tissues was higher as compared with that of the adjacent normal tissues (P < 0.05). In addition, mRNA and protein expression of MTA1 in the MTA1-siRNA group was lower than that in the control and MTA1- niRNA groups (P < 0.05). Adhesion, migration, and invasion capacity of Daoy cells in the MTA1-siRNA group was inhibited as compared with the control and MTA1-niRNA groups (P < 0.05). In conclusion, MTA1 expression was increased in medulloblastoma cells, while MTA1 knockdown in medulloblastoma cells inhibited MTA1 expression. In addition, MTA1 knockdown inhibited the adhesion, migration, and invasive capabilities of medulloblastoma cells. It is possible that MTA1 can serve as a biomarker and a potential therapeutic target for medulloblastoma.

[Establishment and evaluation of a prognostic model for acute pulmonary embolism]

OBJECTIVE

To identify the factors influencing the prognosis of patients with acute pulmonary embolism(PE) and to establish a prognostic model.

METHODS

The clinical data of 331 patients (141 males and 190 females, aged 9 to 87 years ) with acute PE in Fujian Hospital from January 2007 to September 2013 were analyzed. Univariate analysis and logistic regression analysis were used for selecting the independent prognostic factors for acute PE. Based on logistic regression analysis, a prognostic model for PE was established.

RESULTS

Univariate analysis showed that statistically significant (all P<0.05) factors influencing the prognosis of PE were diabetes, tricuspid systolic murmur, body temperature, respiratory rate, heart rate, aspartate aminotransferase, triglycerides, abnormal ECG, mechanical ventilation, circulatory failure during hospitalization, risk stratification of PE, types of treatment, and use of low-molecular-weight heparin and Warfarin. Logistic regression analysis showed that recent (<1 month) operation or fracture, tricuspid systolic murmur, high triglyceride level, circulatory failure during hospitalization and mechanical ventilation were independent factors for poor prognosis of PE, while combined use of low-molecular-weight heparin and Warfarin was a protective factor for the prognosis of PE. The Fisher prognostic model equation was y=0.144+ 1.266x1+ 0.869x2+ 1.794x3-0.517x4+ 3.555x5+ 0.661x6. The accuracy of the Fisher discriminant function was 93.0%.

CONCLUSION

Recent (<1 month) operation or fracture, tricuspid systolic murmur, high triglyceride level, shock during hospitalization and mechanical ventilation were signs of poor prognosis for PE, while combined use of low-molecular-weight heparin and Warfarin were beneficial for the prognosis. The discriminant function based on these data can be helpful for predicting the prognosis of patients with PE.

Diffuse interstitial and multiple cavitary lung lesions due to Talaromyces marneffei infection in a non-HIV patient

A 57-year-old man presented with unproductive cough and dyspnea for 6 months in Fujian Province, China. His misuse of a large amount of steroids (accumulated dose equivalent to 3530 mg prednisolone) resulted in Talaromyces marneffei infection. Chest computed tomographic scan revealed diffuse interstitial and multiple cavitary lung lesions. Treatment with amphotericin B combined with itraconazole resulted in total recovery, with marked regression of lung lesions.

[Eisenmenger's syndrome in pregnancy: a case report and literature review]

OBJECTIVE

To investigate the clinical presentation, diagnosis and treatment of the Eisenmenger's syndrome in pregnancy.

METHODS

One case of Eisenmenger's syndrome in pregnancy in our hospital was retrospectively analyzed and the literature reviewed.

RESULTS

This patient who received antenatal care irregularly in other hospital was diagnosed with Eisenmenger's syndrome with the symptoms of chest distress. The other hospital suggested her to terminate pregnancy, but the patient refused. She was admitted to our hospital in her late pregnancy, received the treatment of rest, oxygen, blood gas and pulmonary artery pressure monitoring. Considering perioperative pulmonary hypertension crisis likely to occur, pulmonary artery catheter was placed preoperatively. In general anesthesia, the cesarean was performed. After operation, the patient was transferred to the intensive care unit, with the treatment of expanding blood vessels, reducing pulmonary artery pressure, administering anticoagulation and preventing infection. One week later, the patient was discharged from hospital with smooth condition.

CONCLUSION

Eisenmenger's syndrome in pregnancy is associated with extremely poor maternal and fetal outcome. Termination of pregnancy should be offered to such patients. When interruption of pregnancy is refused, the early hospital admission is needed. The patients should be managed in a high-risk pregnancy unit by a multidisciplinary team from obstetrics, cardiology, anesthesia and pediatrics for improving pregnancy outcomes.

Physician Scientist Training in the United States: A Survey of the Current Literature

The declining number of physician scientists is an alarming issue. A systematic review of all existing programs described in the literature was performed, so as to highlight which programs may serve as the best models for the training of successful physician scientists. Multiple databases were searched, and 1,294 articles related to physician scientist training were identified. Preference was given to studies that looked at number of confirmed publications and/or research grants as primary outcomes. Thirteen programs were identified in nine studies. Eighty-three percent of Medical Scientist Training Program (MSTP) graduates, 77% of Clinician Investigator Training Program (CI) graduates, and only 16% of Medical Fellows Program graduates entered a career in academics. Seventy-eight percent of MSTP graduates succeeded in obtaining National Institute of Health (NIH) grants, while only 15% of Mayo Clinic National Research Service Award-T32 graduates obtained NIH grants. MSTP physician scientists who graduated in 1990 had 13.5 ± 12.5 publications, while MSTP physician scientists who graduated in 1975 had 51.2 ± 38.3 publications. Additionally, graduates from the Mayo Clinic's MD-PhD Program, the CI Program, and the NSRA Program had 18.2 ± 20.1, 26.5 ± 24.5, and 17.9 ± 26.3 publications, respectively. MSTP is a successful model for the training of physician scientists in the United States, but training at the postgraduate level also shows promising outcomes. An increase in the number of positions available for training at the postgraduate level should be considered.

Optimal treatment for asymptomatic neurosyphilis

In the pre-penicillin era, patients with asymptomatic neurosyphilis (ANS) were more likely to develop long-term neurological sequelae than those patients with normal cerebrospinal fluid (CSF). Although benzathine penicillin G cannot achieve treponemicidal levels in the CSF, decreased rates of neurological complications of syphilis and non-treponemal titre serological responses are usually observed after treatment with this antibiotic. We here a homosexual man with ANS successfully treated with benzathine penicillin G. This case suggests that reconsideration on the necessity of a lumbar puncture in HIV-infected patients with ANS is warranted.

Resurfacing arthroplasty for hip dysplasia: a prospective randomised study

In this prospective study a total of 80 consecutive Chinese patients with Crowe type I or II developmental dysplasia of the hip were randomly assigned for hip resurfacing arthroplasty (HRA) or total hip replacement (THR). Three patients assigned to HRA were converted to THR, and three HRA patients and two THR patients were lost to follow-up. This left a total of 34 patients (37 hips) who underwent HRA and 38 (39 hips) who underwent THR. The mean follow-up was 59.4 months (52 to 70) in the HRA group and 60.6 months (50 to 72) in the THR group. There was no failure of the prosthesis in either group. Flexion of the hip was significantly better after HRA, but there was no difference in the mean post-operative Harris hip scores between the groups. The mean size of the acetabular component in the HRA group was significantly larger than in the THR group (49.5 mm vs 46.1 mm, p = 0.001). There was no difference in the mean abduction angle of the acetabular component between the two groups. Although the patients in this series had risk factors for failure after HRA, such as low body weight, small femoral heads and dysplasia, the clinical results of resurfacing in those with Crowe type I or II hip dysplasia were satisfactory. Patients in the HRA group had a better range of movement, although neck-cup impingement was observed. However, more acetabular bone was sacrificed in HRA patients, and it is unclear whether this will have an adverse effect in the long term.

Heart retransplantation for pediatric primary allograft failure

PURPOSE

Heart transplantation is indicated for children with end-stage heart failure or complex inoperable congenital defects. When the transplanted heart fails, retransplantation is suggested and herein we have presented the prognosis of these pediatric cases.

MATERIALS AND METHODS

From March 1987 to March 2011, we performed 404 heart transplantations including 45 pediatric patients, 6 (13.3%) of whom experienced graft failure requiring retransplantation. Only four of the six patients (66.7%) had a chance for retransplantation.

RESULTS

Six of 45 pediatric heart transplant patients (13.3%) experienced graft failure requiring retransplantation. Four of them (66.7%) underwent retransplantation. Only one of the four died due to severe postoperative sepsis with acute respiratory distress. The other three patients recovered well and remain alive with no neurological sequelae; all are in New York Heart Association functional classification I at present.

CONCLUSION

Pediatric post-heart graft failure require expectations retransplantation, which shows a good prognosis.

Medical education in Vietnam

BACKGROUND

Vietnam is one of the most populous countries in Southeast Asia, yet it displays an unsettling lack of doctors.

AIMS

Medical education is an important factor contributing to this issue, yet little is known about the system currently in place in Vietnam.

METHODS

Through an extensive literary search of medical schools' and Ministry of Health's data, we have examined the current medical education system in Vietnam.

RESULTS

At present, there are 12 medical universities, and the general curriculum at each university follows a national framework but tends to vary from university to university. Medical training lasts either 4 or 6 years, with competitive graduates attending residency programs following graduation. While examinations are required to graduate, the lack of a national licensing exam makes it difficult to ensure that a nation-wide standard of quality exists, both at the medical universities themselves as well as amongst the doctors graduating from them.

CONCLUSIONS

The development and institution of a national exam would introduce a standard of training throughout Vietnam's medical education system. Further, a substantial portion of a doctor's education is in subjects that are loosely related to medicine. When looking forward it will be important to evaluate whether or not these non-medical subjects detract from the quality of medical training.

Dynamic nuclear spin resonance in n-GaAs

The dynamics of optically detected nuclear magnetic resonance is studied in n-GaAs via time-resolved Kerr rotation using an on-chip microcoil for rf field generation. Both optically allowed and optically forbidden NMR are observed with a dynamics controlled by the interplay between dynamic nuclear polarization via hyperfine interaction with optically generated spin-polarized electrons and nuclear spin depolarization due to magnetic resonance absorption. Comparing the characteristic nuclear spin relaxation rate obtained in experiment with master equation simulations, the underlying nuclear spin depolarization mechanism for each resonance is extracted.