1.Effects of Dimethylformamide on Spermatozoa Quality and Sex Hormone Levels in Male Mice
Lu HUANG ; Xujian HOU ; Yunhe ZHENG
Journal of Environment and Health 2007;0(07):-
Objective To study the effects of DMF on the quality of spermatozoa and sex hormone levels in male mice,and the possible mechanism. Methods Forty male KM mice were randomly divided into four groups and then treated with DMF dissolved in distilled water by gavage (10 ml/kg) at the doses of 0,0.5,1 and 2 g/kg,once a day for 30 consecutive days. The mice were weighted and then sacrificed on day 31. The epididymises were collected for determination of sperm motility,sperm counting and determination of abnormal sperm rate. The T,LH,and FSH levels in serum were determined. Results Compared with the control group,mice in all treated groups showed significant decrease in body weight (P
2. Epidemiological and spatial-temporal distribution of several natural focus diseases in Gansu province, 2014-2018
Kongfu WEI ; Hong ZHANG ; Jian HE ; Deshan YU ; Xiaoting YANG ; Zhongyi JIANG ; Faxiang GOU ; Yao CHENG ; Haixia LIU ; Yunhe ZHENG ; Xiaojuan JIANG ; Xinfeng LIU
Chinese Journal of Epidemiology 2019;40(8):947-952
Objective:
To analyze the epidemiological and spatial-temporal distribution of Brucellosis, epidemic encephalitis B and hemorrhagic fever with renal syndrome (HFRS) in Gansu province during 2014-2018 so as to provide evidence for the prevention and control of those diseases.
Methods:
A database was established in Gansu province from 2014 to 2018, using the geographical information system. A spatial distribution map was drawn, with trend analysis and space-time clustering used to study the 3-dimention of the diseases, by using both ArcGIS 10.5 and SaTScan 9.6 softwares.
Results:
Results from the trend surface analysis showed that the incidence of Brucellosis decreased gradually from north to south parts while the U type curve could reflect the distribution from the east to the west areas. Incidence of epidemic encephalitis B decreased significantly from south to north areas in the province, with incidence higher in the eastern than in the mid-west region. Difference on the incidence of HFRS was not significantly visible in the eastern and western regions, while the incidence was slightly higher in the southern than the northern parts of the province. Spatial and space-time clustering did exist among the 3 diseases in Gansu from 2014 to 2018. The areas with clusters of Brucellosis appeared in the eastern parts during 2014-2015, including 19 counties. The areas with secondary clusters of Brucellosis were seen in the Hexi district, including 4 counties, during 2017-2018. The areas with high incidence of epidemic encephalitis B were clustered in the middle and southeast areas, including 32 counties, during 2017-2018. Areas with most clusters of HFRS appeared in Min county of Dingxi city in 2018, with the areas of secondary clusters in 8 counties of the eastern areas in 2018.
Conclusions
The overall incidence rates of the 3 natural focus diseases were in a upward trend and showing obvious characteristics on spatial clustering. According to the distributive characteristics, effective measures should be developed accordingly.
3.Enhanced recovery after surgery strategy for cirrhosis patients undergoing hepatectomy: experience in a single research center
Yiling ZHENG ; Liming WANG ; Fan WU ; Weiqi RONG ; Yunhe LIU ; Kai ZHANG ; Jianxiong WU
Annals of Surgical Treatment and Research 2020;98(5):224-234
Purpose:
To evaluate the safety and effectiveness of an enhanced recovery after surgery (ERAS) programme after curative liver resection in cirrhotic hepatocellular carcinoma (HCC) patients.
Methods:
One hundred sixty-two patients were enrolled in the study; 80 patients whose data were collected prospectively were assigned to the ERAS group, and 82 patients whose data were collected retrospectively were assigned to the control group. Preoperative clinicopathologic factors, surgical factors, and postoperative outcomes of the 2 groups were compared. Logistic regression was applied to explore potential predictors of hospital stay and morbidity.
Results:
The postoperative hospital stay, postoperative complication rate, and recovery of liver function on postoperative day 5 seemed to be better in the ERAS group. The composition of complications was different in the 2 groups; pleural effusion and postoperative ascites were more common in the control group, and indocyanine green retention at 15 minutes, operation time, preoperative alanine aminotransferase, and number of liver segmentectomies were associated with postoperative complications rather than ERAS intervention.
Conclusion
The ERAS programme is safe and effective for HCC patients with chronic liver disease undergoing hepatectomy, but it seems that surgical factors, such as operation type, have a greater impact on morbidity than other factors. Operative characteristics such as the method of blood loss control and the volume of liver resection should be augmented into ERAS protocol of hepatectomy.
4.Investigation of the risk assessment ,prevention and management for perioperative stroke in elderly patients with hip fractures
Chaoqun WANG ; Shuaijie ZHAI ; Yunhe CHANG ; Yang ZHENG ; Zhiqian WANG ; Yujia LI ; Yahui ZHANG ; Qingxian WANG
Chinese Journal of Geriatrics 2018;37(12):1332-1336
Objective To investigate the risk assessment ,prevention and management for perioperative stroke in elderly patients with hip fractures. Methods A total of 179 patients aged 65 years and older were admitted to our department due to hip fracture. In managements of perioperative stroke ,the preoperative risk assessment and the management of stroke ,identifying the risk population for stroke prevention ,controlling risk factors of the preoperative stroke ,intraoperative monitoring , postoperative treatment ,etc.were studied retrospectively.The incidence of perioperative stroke was recorded and analyzed. Results Of 179 patients with hip fracture ,overviews of diagnosis and treatment were as follows.Twenty-four (24/179 ,13.41% ) cases did not receive operative treatments.Head and neck CT angiography(CTA)-showed severe stenosis or occlusion of intracranial artery and internal carotid artery were in 9(5.03% ,9/179)patients ,of whom the 5(2.79% ,5/179) cases underwent cerebrovascular digital subtraction angiography (DSA ) ,balloon dilation and stent implantation ,then received the operation for hip fracture 10 days later ,finally were discharged uneventfully.1 (0.56% ,1/179 ) patient underwent orthopaedic surgery due to the results of DSA showing no indication of interventional therapy ,and was discharged unevenfully.3 (1.68% ,3/179 ) patients refused to receive the further DSA examination or interventional therapy ,strongly demanded for orthopaedic surgery and would take the surgical risk ,and were discharged uneventfully.2(1.12% , 2/179)patients were found to have cerebral aneurysm diagnosed by CTA and DSA ,and underwent surgery for hipfracture without special treatment.2(1.12% ,2/179)patients were diagnosed as new occurrence of cerebral infarction before the operation ,and received head and carotid stenting at the department of cerebrovascular surgery ,followed by combined antithrombotic therapy of aspirin , clopidogrel and low molecular weight heparin for 4 weeks ,then underwent orthopaedic surgery for hip fracture.2 (1.12% ,2/179 ) patients were diagnosed as new cerebral infarction after orthopaedic surgery ,then were transferred to the department of neurology for treatment. Conclusions The thorough preoperative risk assessment and management of stroke ,reasonable perioperative antiplatelet and anticoagulation therapy ,intense intraoperative monitoring and active postoperative complications management make it possible for high-risk and new ischemic stroke patients with hip fractures to receive early orthopaedic treatment.
5.A prospective multicenter randomized non-inferiority clinical trial study of a domestic disposable digital flexible cystoscope versus a reusable Olympus digital flexible cystoscope
Yue XIA ; Zongwei PAN ; Guang SHAN ; Bin CHEN ; Ming LEI ; Wenbiao LIAO ; Liang CHEN ; Lingchao MENG ; Yunhe XIONG ; Hong ZHENG ; Huijun QIAN ; Tianpeng WU ; Sixing YANG
Chinese Journal of Urology 2022;43(9):690-695
Objective:To investigate the availability and safety of a domestic disposable digital flexible cystoscope compared with a reusable Olympus digital flexible cystoscope in cystoscopy and removal of double J stent.Methods:From August 2018 to March 2019, patients were enrolled in this prospective, open, multicenter, randomized, parallel positive controlled clinical trial study, which were from department of Urology in Renmin Hospital of Wuhan University, the First Affiliated Hospital of Xiamen University and the First Affiliated Hospital of Guangzhou Medical University. The experimental group and control group were assigned into a 1∶1 ratio by random table method. Inclusion criteria included age≥18 years and have indications for cystoscopy or removal of double J stent. Exclusion criteria included patients having acute genitourinary tract infection, having tuberculous bladder contracture, bladder capacity less than 50ml, having urethrostenosis, female menstrual period, pregnancy and lactation, having difficulty for lithotomy position, having serious cardio-cerebrovascular disease and liver or kidney dysfunction. A domestic disposable digital flexible cystoscope was adopted in the experimental group, whereas a reusable Olympus digital flexible cystoscope was used in the control group. Acceptability of image was defined as primary availability indicator, while success rate of working and performance score were defined as secondary availability indicators and mean operating time was calculated for cystoscopy only and cystoscopy plus removal of double J stent respectively, yet rate of adverse event as well as rate of equipment defects were sorted as safety indicators.Results:A total of 188 cases which were listed in per protocol set completed the clinical trial study successfully. There were 95 cases in the experimental group and 93 cases in the control group. Acceptability of image was 93.68%(89/95) and 96.77%(90/93) respectively in two groups( P=0.52). Success rate of working was 100.00%(95/95) and 98.92%(92/93) respectively in two groups ( P=0.49). Performance score was 14.41±0.93 and 14.56±0.84 respectively in two groups ( P=0.23). Mean operating time (MOT) only for cystoscopy was (15.3±2.6) min and (15.4±3.3)min respectively in two groups ( P=0.93), while MOT for cystoscopy plus removal of double J stent was (21.0±3.2) min and (21.7±3.9) min respectively in two groups ( P=0.69). Rate of adverse event was 8.42%(8/95) and 9.68%(9/93) respectively in two groups( P=0.76). There was no equipment defects in both groups. Conclusions:There is no statistical difference in acceptability of image, success rate of working, performance score, mean operating time for cystoscopy or removal of double J stent, rate of adverse events and rate of equipment defects. A domestic disposable digital flexible cystoscope has shown non-inferiority in the availability and safety compared with a reusable Olympus digital flexible cystoscope.
6.Comparison of the efficacy of different surgical strategies in the treatment of patients with initially resectable gastric cancer liver metastases
Li LI ; Yunhe GAO ; Lu ZANG ; Kan XUE ; Bin KE ; Liang SHANG ; Zhaoqing TANG ; Jiang YU ; Yanrui LIANG ; Zirui HE ; Hualong ZHENG ; Hua HUANG ; Jianping XIONG ; Zhongyuan HE ; Jiyang LI ; Tingting LU ; Qiying SONG ; Shihe LIU ; Yawen CHEN ; Yun TANG ; Han LIANG ; Zhi QIAO ; Lin CHEN
Chinese Journal of Surgery 2024;62(5):370-378
Objective:To examine the impact of varied surgical treatment strategies on the prognosis of patients with initial resectable gastric cancer liver metastases (IR-GCLM).Methods:This is a retrospective cohort study. Employing a retrospective cohort design, the study selected clinicopathological data from the national multi-center retrospective cohort study database, focusing on 282 patients with IR-GCLM who underwent surgical intervention between January 2010 and December 2019. There were 231 males and 51 males, aging ( M(IQR)) 61 (14) years (range: 27 to 80 years). These patients were stratified into radical and palliative treatment groups based on treatment decisions. Survival curves were generated using the Kaplan-Meier method and distinctions in survival rates were assessed using the Log-rank test. The Cox risk regression model evaluated HR for various factors, controlling for confounders through multivariate analysis to comprehensively evaluate the influence of surgery on the prognosis of IR-GCLM patients. A restricted cubic spline Cox proportional hazard model assessed and delineated intricate associations between measured variables and prognosis. At the same time, the X-tile served as an auxiliary tool to identify critical thresholds in the survival analysis for IR-GCLM patients. Subgroup analysis was then conducted to identify potential beneficiary populations in different surgical treatments. Results:(1) The radical group comprised 118 patients, all undergoing R0 resection or local physical therapy of primary and metastatic lesions. The palliative group comprised 164 patients, with 52 cases undergoing palliative resections for gastric primary tumors and liver metastases, 56 cases undergoing radical resections for gastric primary tumors only, 45 cases undergoing palliative resections for gastric primary tumors, and 11 cases receiving palliative treatments for liver metastases. A statistically significant distinction was observed between the groups regarding the site and the number of liver metastases (both P<0.05). (2) The median overall survival (OS) of the 282 patients was 22.7 months (95% CI: 17.8 to 27.6 months), with 1-year and 3-year OS rates were 65.4% and 35.6%, respectively. The 1-year OS rates for patients in the radical surgical group and palliative surgical group were 68.3% and 63.1%, while the corresponding 3-year OS rates were 42.2% and 29.9%, respectively. A comparison of OS between the two groups showed no statistically significant difference ( P=0.254). Further analysis indicated that patients undergoing palliative gastric cancer resection alone had a significantly worse prognosis compared to other surgical options ( HR=1.98, 95% CI: 1.21 to 3.24, P=0.006). (3) The size of the primary gastric tumor significantly influenced the patients′ prognosis ( HR=2.01, 95% CI: 1.45 to 2.79, P<0.01), with HR showing a progressively increasing trend as tumor size increased. (4) Subgroup analysis indicates that radical treatment may be more effective compared to palliative treatment in the following specific cases: well/moderately differentiated tumors ( HR=2.84, 95% CI 1.49 to 5.41, P=0.001), and patients with liver metastases located in the left lobe of the liver ( HR=2.06, 95% CI 1.19 to 3.57, P=0.010). Conclusions:In patients with IR-GCLM, radical surgery did not produce a significant improvement in the overall prognosis compared to palliative surgery. However, within specific patient subgroups (well/moderately differentiated tumors, and patients with liver metastases located in the left lobe of the liver), radical treatment can significantly improve prognosis compared to palliative approaches.
7.Comparison of the efficacy of different surgical strategies in the treatment of patients with initially resectable gastric cancer liver metastases
Li LI ; Yunhe GAO ; Lu ZANG ; Kan XUE ; Bin KE ; Liang SHANG ; Zhaoqing TANG ; Jiang YU ; Yanrui LIANG ; Zirui HE ; Hualong ZHENG ; Hua HUANG ; Jianping XIONG ; Zhongyuan HE ; Jiyang LI ; Tingting LU ; Qiying SONG ; Shihe LIU ; Yawen CHEN ; Yun TANG ; Han LIANG ; Zhi QIAO ; Lin CHEN
Chinese Journal of Surgery 2024;62(5):370-378
Objective:To examine the impact of varied surgical treatment strategies on the prognosis of patients with initial resectable gastric cancer liver metastases (IR-GCLM).Methods:This is a retrospective cohort study. Employing a retrospective cohort design, the study selected clinicopathological data from the national multi-center retrospective cohort study database, focusing on 282 patients with IR-GCLM who underwent surgical intervention between January 2010 and December 2019. There were 231 males and 51 males, aging ( M(IQR)) 61 (14) years (range: 27 to 80 years). These patients were stratified into radical and palliative treatment groups based on treatment decisions. Survival curves were generated using the Kaplan-Meier method and distinctions in survival rates were assessed using the Log-rank test. The Cox risk regression model evaluated HR for various factors, controlling for confounders through multivariate analysis to comprehensively evaluate the influence of surgery on the prognosis of IR-GCLM patients. A restricted cubic spline Cox proportional hazard model assessed and delineated intricate associations between measured variables and prognosis. At the same time, the X-tile served as an auxiliary tool to identify critical thresholds in the survival analysis for IR-GCLM patients. Subgroup analysis was then conducted to identify potential beneficiary populations in different surgical treatments. Results:(1) The radical group comprised 118 patients, all undergoing R0 resection or local physical therapy of primary and metastatic lesions. The palliative group comprised 164 patients, with 52 cases undergoing palliative resections for gastric primary tumors and liver metastases, 56 cases undergoing radical resections for gastric primary tumors only, 45 cases undergoing palliative resections for gastric primary tumors, and 11 cases receiving palliative treatments for liver metastases. A statistically significant distinction was observed between the groups regarding the site and the number of liver metastases (both P<0.05). (2) The median overall survival (OS) of the 282 patients was 22.7 months (95% CI: 17.8 to 27.6 months), with 1-year and 3-year OS rates were 65.4% and 35.6%, respectively. The 1-year OS rates for patients in the radical surgical group and palliative surgical group were 68.3% and 63.1%, while the corresponding 3-year OS rates were 42.2% and 29.9%, respectively. A comparison of OS between the two groups showed no statistically significant difference ( P=0.254). Further analysis indicated that patients undergoing palliative gastric cancer resection alone had a significantly worse prognosis compared to other surgical options ( HR=1.98, 95% CI: 1.21 to 3.24, P=0.006). (3) The size of the primary gastric tumor significantly influenced the patients′ prognosis ( HR=2.01, 95% CI: 1.45 to 2.79, P<0.01), with HR showing a progressively increasing trend as tumor size increased. (4) Subgroup analysis indicates that radical treatment may be more effective compared to palliative treatment in the following specific cases: well/moderately differentiated tumors ( HR=2.84, 95% CI 1.49 to 5.41, P=0.001), and patients with liver metastases located in the left lobe of the liver ( HR=2.06, 95% CI 1.19 to 3.57, P=0.010). Conclusions:In patients with IR-GCLM, radical surgery did not produce a significant improvement in the overall prognosis compared to palliative surgery. However, within specific patient subgroups (well/moderately differentiated tumors, and patients with liver metastases located in the left lobe of the liver), radical treatment can significantly improve prognosis compared to palliative approaches.
8.Prognosis and influencing factors analysis of patients with initially resectable gastric cancer liver metastasis who were treated by different modalities: a nationwide, multicenter clinical study
Li LI ; Yunhe GAO ; Liang SHANG ; Zhaoqing TANG ; Kan XUE ; Jiang YU ; Yanrui LIANG ; Zirui HE ; Bin KE ; Hualong ZHENG ; Hua HUANG ; Jianping XIONG ; Zhongyuan HE ; Jiyang LI ; Tingting LU ; Qiying SONG ; Shihe LIU ; Hongqing XI ; Yun TANG ; Zhi QIAO ; Han LIANG ; Jiafu JI ; Lin CHEN
Chinese Journal of Digestive Surgery 2024;23(1):114-124
Objective:To investigate the prognosis of patients with initially resectable gastric cancer liver metastasis (GCLM) who were treated by different modalities, and analyze the influencing factors for prognosis of patients.Methods:The retrospective cohort study was conducted. The clinicopathological data of 327 patients with initially resectable GCLM who were included in the database of a nationwide multicenter retrospective cohort study on GCLM based on real-world data from January 2010 to December 2019 were collected. There were 267 males and 60 females, aged 61(54,68)years. According to the specific situations of patients, treatment modalities included radical surgery combined with systemic treatment, palliative surgery combined with systemic treatment, and systemic treatment alone. Observation indicators: (1) clinical characteristics of patients who were treated by different modalities; (2) prognostic outcomes of patients who were treated by different modalities; (3) analysis of influencing factors for prognosis of patients with initially resectable GCLM; (4) screening of potential beneficiaries in patients who were treated by radical surgery plus systemic treatment and patients who were treated by palliative surgery plus systemic treatment. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was conducted using the independent sample t test. Measurement data with skewed distribution were represented as M( Q1, Q3), and comparison between groups was conducted using the rank sum test. Count data were described as absolute numbers or percentages, and comparison between groups was conducted using the chi-square test. The Kaplan-Meier method was used to calculate survival rate and draw survival curve, and Log-Rank test was used for survival analysis. Univariate and multivariate analyses were conducted using the COX proportional hazard regression model. The propensity score matching was employed by the 1:1 nearest neighbor matching method with a caliper value of 0.1. The forest plots were utilized to evaluate potential benefits of diverse surgical combined with systemic treatments within the population. Results:(1) Clinical characteristics of patients who were treated by different modalities. Of 327 patients, there were 118 cases undergoing radical surgery plus systemic treatment, 164 cases undergoing palliative surgery plus systemic treatment, and 45 cases undergoing systemic treatment alone. There were significant differences in smoking, drinking, site of primary gastric tumor, diameter of primary gastric tumor, site of liver metastasis, and metastatic interval among the three groups of patients ( P<0.05). (2) Prognostic outcomes of patients who were treated by different modalities. The median overall survival time of the 327 pati-ents was 19.9 months (95% confidence interval as 14.9-24.9 months), with 1-, 3-year overall survival rate of 61.3%, 32.7%, respectively. The 1-year overall survival rates of patients undergoing radical surgery plus systemic treatment, palliative surgery plus systemic treatment and systemic treatment alone were 68.3%, 63.1%, 30.6%, and the 3-year overall survival rates were 41.1%, 29.9%, 11.9%, showing a significant difference in overall survival rate among the three groups of patients ( χ2=19.46, P<0.05). Results of further analysis showed that there was a significant difference in overall survival rate between patients undergoing radical surgery plus systemic treatment and patients undergoing systemic treatment alone ( hazard ratio=0.40, 95% confidence interval as 0.26-0.61, P<0.05), between patients undergoing palliative surgery plus systemic treatment and patients under-going systemic treatment alone ( hazard ratio=0.47, 95% confidence interval as 0.32-0.71, P<0.05). (3) Analysis of influencing factors for prognosis of patients with initially resectable GCLM. Results of multivariate analysis showed that the larger primary gastric tumor, poorly differentiated tumor, larger liver metastasis, multiple hepatic metastases were independent risk factors for prognosis of patients with initially resectable GCLM ( hazard ratio=1.20, 1.70, 1.20, 2.06, 95% confidence interval as 1.14-1.27, 1.25-2.31, 1.04-1.42, 1.45-2.92, P<0.05) and immunotherapy or targeted therapy, the treatment modality of radical or palliative surgery plus systemic therapy were independent protective factors for prognosis of patients with initially resectable GCLM ( hazard ratio=0.60, 0.39, 0.46, 95% confidence interval as 0.42-0.87, 0.25-0.60, 0.30-0.70, P<0.05). (4) Screening of potentinal beneficiaries in patients who were treated by radical surgery plus systemic treatment and patients who were treated by palliative surgery plus systemic treatment. Results of forest plots analysis showed that for patients with high-moderate differentiated GCLM and patients with liver metastasis located in the left liver, the overall survival rate of patients undergoing radical surgery plus systemic treatment was better than patients undergoing palliative surgery plus systemic treatment ( hazard ratio=0.21, 0.42, 95% confidence interval as 0.09-0.48, 0.23-0.78, P<0.05). Conclusions:Compared to systemic therapy alone, both radical and palliative surgery plus systemic therapy can improve the pro-gnosis of patients with initially resectable GCLM. The larger primary gastric tumor, poorly differen-tiated tumor, larger liver metastasis, multiple hepatic metastases are independent risk factors for prognosis of patients with initial resectable GCLM and immunotherapy or targeted therapy, the treatment modality of radical or palliative surgery plus systemic therapy are independent protective factors for prognosis of patients with initially resectable GCLM.
9.Epidemiological characteristics of COVID-19 in Gansu province
Faxiang GOU ; Xiaoshu ZHANG ; Jinxi YAO ; Deshan YU ; Kongfu WEI ; Hong ZHANG ; Xiaoting YANG ; Jianjun YANG ; Haixia LIU ; Yao CHENG ; Xiaojuan JIANG ; Yunhe ZHENG ; Bin WU ; Xinfeng LIU ; Hui LI
Chinese Journal of Epidemiology 2020;41(9):1415-1419
Objective:To understand the epidemiological characteristics of COVID-19 cases in different epidemic stages in Gansu province.Methods:Epidemiological investigation was conducted to collect the information of confirmed COVID-19 cases, including demographic, epidemiological and clinical information.Results:As of 25 February 2020, a total of 91 confirmed COVID-19 cases had been reported in Gansu. The epidemic of COVID-19 in Gansu can be divided as three different stages, i.e. imported case stage, imported-case plus indigenous case stage, and indigenous case stage. A total of 63 cases were clustered cases (69.23%), 3 cases were medical staff infected with non-occupational exposure.The initial symptoms included fever (54.95%, 50/91), cough (52.75%, 48/91), or fatigue (28.57%, 26/91), the proportion of each symptom showed a decreasing trend along with the three epidemic stages, but only the differences in proportions of fever (trend χ2=2.20, P<0.05) and fatigue (trend χ2=3.18, P<0.05) among the three epidemic stages were statistically significant. The cases with critical severe symptoms accounted for 42.85% (6/14), 23.73% (14/59) and 16.67% (3/18), respectively, in three epidemic stages, showed a decreasing trend ( H=6.45, P<0.05). Also, the incubation period prolonged along with the epidemic stage ( F=51.65, P<0.01), but the intervals between disease onset and hospital visit ( F=5.32, P<0.01), disease onset and diagnosis ( F=5.25, P<0.01) became shorter along with the epidemic stage. Additionally, the basic reproduction number ( R0) had decreased from 2.61 in imported case stage to 0.66 in indigenous case stage. Conclusions:The COVID-19 epidemic in Gansu was caused by the imported cases, and about 2/3 cases were clustered ones. No medical worker was observed to be infected by occupational exposure. With the progression of COVID-19 epidemic in Gansu, the change in initial symptom and incubation period suggests. the early screening cannot only depend on body temperature monitoring.
10.Influence of PCR cycle number on microbial diversity analysis through next generation sequencing.
Yunhe AN ; Lijuan GAO ; Junbo LI ; Yanjie TIAN ; Jinlong WANG ; Xuejuan ZHENG ; Huijuan WU
Chinese Journal of Biotechnology 2016;32(8):1115-1123
Using of high throughput sequencing technology to study the microbial diversity in complex samples has become one of the hottest issues in the field of microbial diversity research. In this study, the soil and sheep rumen chyme samples were used to extract DNA, respectively. Then the 25 ng total DNA was used to amplify the 16S rRNA V3 region with 20, 25, 30 PCR cycles, and the final sequencing library was constructed by mixing equal amounts of purified PCR products. Finally, the operational taxonomic unit (OUT) amount, rarefaction curve, microbial number and species were compared through data analysis. It was found that at the same amount of DNA template, the proportion of the community composition was not the best with more numbers of PCR cycle, although the species number was much more. In all, when the PCR cycle number is 25, the number of species and proportion of the community composition were the most optimal both in soil or chyme samples.
Animals
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Bacteria
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classification
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DNA, Bacterial
;
genetics
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Gene Library
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High-Throughput Nucleotide Sequencing
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Polymerase Chain Reaction
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methods
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RNA, Ribosomal, 16S
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genetics
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Rumen
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microbiology
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Sheep
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Soil Microbiology