[Analysis of problems and management of in vitro diagnostic reagent clinical trials in medical laboratory].

Clinical trials are an important method for evaluating the safety and efficacy of in vitro diagnostic reagents, and are a key basis for product registration review and approval. In order to strengthen the management of clinical trials of in vitro diagnostic reagents, the National Medical Products Administration and relevant departments have formulated a series of regulations at the regulatory level, and require applicants and clinical trial institutions to establish a quality management system for clinical trials of in vitro diagnostic reagents. Medical laboratory is the main department and implementer of in vitro diagnostic reagent clinical trials in medical institutions. In recent years, with the rapid development of the in vitro diagnostic industry, the clinical trial projects of in vitro diagnostic reagents conducted by medical laboratory have been increasing day by day. However, there are currently few discussions on the clinical trial of in vitro diagnostic reagents from the perspective of researchers. Therefore, this article summarizes the characteristics of clinical trials of in vitro diagnostic reagents, analyzes the problems and difficulties in conducting clinical trials of in vitro diagnostic reagents in current medical laboratories, and introduces the laboratory's experience in management; to provide reference for medical testing laboratories that have not yet conducted or have already conducted clinical trials of in vitro diagnostic reagents, in order to improve the quality and efficiency of clinical trials.

[Clinical features and prognostic factors of AIDS-associated diffuse large B-cell lymphoma].

To explore the general clinical features and treatment outcomes of patients with AIDS-related diffuse large B-cell lymphoma (AIDS-DLBCL) and provide a theoretical basis for diagnosis and treatment, survival prognosis, prevention and management of AIDS-DLBCL patients. AIDS-DLBCL patients who received combined antiretroviral therapy (cART) at Changsha First Hospital from January 2017 to January 2020 were selected in this study. The survival curves were plotted using the Kaplan-Meier method, and the Cox proportional hazards regression model was used to analyze the association between AIDS-DLBCL specific variables and progression-free survival and overall survival. Correlation analysis was conducted based on the clinical features of the patients. A total of 50 AIDS-DLBCL patients were included. Their median age (Q1, Q3) was 52 (44, 59) years, of whom 46 (92%) were male. About 20 (40%) patients received treatment with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP), while 23 patients (46%) received treatment with rituximab combined with cyclophosphamide, doxorubicin, vincristine, and prednisone (RCHOP). Survival curve analysis showed that the 2-year progression-free survival rate and overall survival rate of AIDS-DLBCL patients were 56.9% and 61.6%, respectively. Patients with RCHOP protocol combined with EBV-DNA≥1 000 copies/ml had higher progression-free survival rate (χ2=3.844, P=0.043) and overall survival rate (χ2=4.662, P=0.031) than those with CHOP protocol combined with EBV-DNA≥1 000 copies/ml. A multivariate analysis showed that male (HR=2.70, 95%CI:1.10-6.80), EB viral load≥1 000 copies/ml (HR=1.75, 95%CI:1.12-2.84), HIV-RNA≥200 copies/ml (HR=4.64, 95%CI: 1.73-12.15), ECOG PS score of 2 to 4 points (HR=3.54, 95%CI:1.62-7.33), and international prognostic index (IPI) score of 3 to 5 points (HR=5.21, 95%CI:1.39-20.14) were at a higher risk of disease progression. Patients with EB viral load≥1 000 copies/ml (HR=0.07, 95%CI:0.05-0.93) on the RCHOP regimen had a small risk of disease progression. Males (HR=2.87, 95%CI:1.65-9.17), EB viral load≥1 000 copies/ml (HR=1.61, 95%CI:4.02-9.36), HIV-RNA≥200 copies/ml (HR=1.19, 95%CI:1.58-2.74), ECOG PS score of 2 to 4 (HR=6.42, 95%CI:2.55-14.33), IPI score of 3 to 5 points (HR=2.78, 95%CI:1.41-12.96) had a high risk of mortality. Patients with EB viral load≥1 000 copies/ml (HR=0.24, 95%CI:0.64-0.90) on the RCHOP regimen had a low risk of mortality. In summary, males, ECOG physical status score of 2 to 4 points, IPI score of 3 to 5 points, EB viral load≥1 000 copies/ml and HIV viral load≥200 copies/ml are risk factors affecting progression-free survival and overall survival of AIDS-DLBCL patients. RCHOP regimen combined with EB viral load≥1 000 copies/ml is a protective factor affecting progression-free survival and overall survival in AIDS-DLBCL patients.

Experimental Limits on Solar Reflected Dark Matter with a New Approach on Accelerated-Dark-Matter-Electron Analysis in Semiconductors.

Recently a dark matter-electron (DM-electron) paradigm has drawn much attention. Models beyond the standard halo model describing DM accelerated by high energy celestial bodies are under intense examination as well. In this Letter, a velocity components analysis (VCA) method dedicated to swift analysis of accelerated DM-electron interactions via semiconductor detectors is proposed and the first HPGe detector-based accelerated DM-electron analysis is realized. Utilizing the method, the first germanium based constraint on sub-GeV solar reflected DM-electron interaction is presented with the 205.4 kg·day dataset from the CDEX-10 experiment. In the heavy mediator scenario, our result excels in the mass range of 5-15 keV/c^{2}, achieving a 3 orders of magnitude improvement comparing with previous semiconductor experiments. In the light mediator scenario, the strongest laboratory constraint for DM lighter than 0.1 MeV/c^{2} is presented. The result proves the feasibility and demonstrates the vast potential of the VCA technique in future accelerated DM-electron analyses with semiconductor detectors.

[HbA1c comparison and diagnostic efficacy analysis of multi center different glycosylated hemoglobin detection systems].

Objective: Compare and analyze the results of the domestic Lanyi AH600 glycated hemoglobin analyzer and other different detection systems to understand the comparability of the detection results of different detectors, and establish the best cut point of Lanyi AH600 determination of haemoglobin A1c (HbA1c) in the diagnosis of diabetes. Methods: Multi center cohort study was adopted. The clinical laboratory departments of 18 medical institutions independently collected test samples from their respective hospitals from March to April 2022, and independently completed comparative analysis of the evaluated instrument (Lanyi AH600) and the reference instrument HbA1c. The reference instruments include four different brands of glycosylated hemoglobin meters, including Arkray, Bio-Rad, DOSOH, and Huizhong. Scatter plot was used to calculate the correlation between the results of different detection systems, and the regression equation was calculated. The consistency analysis between the results of different detection systems was evaluated by Bland Altman method. Consistency judgment principles: (1) When the 95% limits of agreement (95% LoA) of the measurement difference was within 0.4% HbA1c and the measurement score was≥80 points, the comparison consistency was good; (2) When the measurement difference of 95% LoA exceeded 0.4% HbA1c, and the measurement score was≥80 points, the comparison consistency was relatively good; (3) The measurement score was less than 80 points, the comparison consistency was poor. The difference between the results of different detection systems was tested by paired sample T test or Wilcoxon paired sign rank sum test; The best cut-off point of diabetes was analyzed by receiver operating characteristic curve (ROC). Results: The correlation coefficient R2 of results between Lanyi AH600 and the reference instrument in 16 hospitals is≥0.99; The Bland Altman consistency analysis showed that the difference of 95% LoA in Nanjing Maternity and Child Health Care Hospital in Jiangsu Province (reference instrument: Arkray HA8180) was -0.486%-0.325%, and the measurement score was 94.6 points (473/500); The difference of 95% LoA in the Tibetan Traditional Medical Hospital of TAR (reference instrument: Bio-Rad Variant II) was -0.727%-0.612%, and the measurement score was 89.8 points; The difference of 95% LoA in the People's Hospital of Chongqing Liang Jiang New Area (reference instrument: Huizhong MQ-2000PT) was -0.231%-0.461%, and the measurement score was 96.6 points; The difference of 95% LoA in the Taihe Hospital of traditional Chinese Medicine in Anhui Province (reference instrument: Huizhong MQ-2000PT) was -0.469%-0.479%, and the measurement score was 91.9 points. The other 14 hospitals, Lanyi AH600, were compared with 4 reference instrument brands, the difference of 95% LoA was less than 0.4% HbA1c, and the scores were all greater than 95 points. The results of paired sample T test or Wilcoxon paired sign rank sum test showed that there was no statistically significant difference between Lanyi AH600 and the reference instrument Arkray HA8180 (Z=1.665,P=0.096), with no statistical difference. The mean difference between the measured values of the two instruments was 0.004%. The comparison data of Lanyi AH600 and the reference instrument of all other institutions had significant differences (all P<0.001), however, it was necessary to consider whether it was within the clinical acceptable range in combination with the results of the Bland-Altman consistency analysis. The ROC curve of HbA1c detected by Lanyi AH600 in 985 patients with diabetes and 3 423 patients with non-diabetes was analyzed, the area under curve (AUC) was 0.877, the standard error was 0.007, and the 95% confidence interval 95%CI was (0.864, 0.891), which was statistically significant (P<0.001). The maximum value of Youden index was 0.634, and the corresponding HbA1c cut point was 6.235%. The sensitivity and specificity of diabetes diagnosis were 76.2% and 87.2%, respectively. Conclusion: Among the hospitals and instruments currently included in this study, among these four hospitals included Nanjing Maternity and Child Health Care Hospital in Jiangsu Province (reference instrument: Arkray HA8180), Tibetan Traditional Medical Hospital of TAR (reference instrument: Bio-Rad Variant Ⅱ), the People's Hospital of Chongqing Liang Jiang New Area (reference instrument: Huizhong MQ-2000PT), and the Taihe Hospital of traditional Chinese Medicine in Anhui Province (reference instrument: Huizhong MQ-2000PT), the comparison between Lanyi AH600 and the reference instruments showed relatively good consistency, while the other 14 hospitals involved four different brands of reference instruments: Arkray, Bio-Rad, DOSOH, and Huizhong, Lanyi AH600 had good consistency with its comparison. The best cut point of the domestic Lanyi AH600 for detecting HbA1c in the diagnosis of diabetes is 6.235%.

[Clinical significance of pathological diagnosis and genetic abnormalities detection in gastrointestinal stromal tumor using endoscopic biopsy].

Objective: To investigate the clinical significance of pathological diagnosis and genetic abnormalities detection of gastrointestinal stromal tumor (GIST) using endoscopic biopsy. Methods: Patients with GIST diagnosed by endoscopic biopsy (from January 1st, 2016 to August 1st, 2018, at Zhongshan Hospital, Fudan University) were included in this study. This retrospective study evaluated the histopathologic and immunohistochemical (IHC) features, genetic abnormalities of the tumors and the treatment and clinical course of the patients. Results: Totally 4 095 cases of GIST were collected, among which 67 patients (67/4 095, 1.6%) underwent endoscopic biopsy. Forty-eight patients (71.6%) were male and 19 (28.4%) were female, with a mean age of 61 years (range 31-90 years). Fifty-nine lesions were located in stomach and eight in duodenum. Of all the 67 cases, 47 were spindle type, 14 were epithelioid type, and 6 mixed type. IHC staining showed the positive rates were 100.0% (64/64) for DOG1, 98.4% (62/63) for CD117, 87.5% (56/64) for CD34, 3.6% (2/56) for S-100 protein, 12.1% (7/58) for α-SMA, 12.3% (7/57) for desmin and 4.0% (2/50) for CKpan. Morphologically, 34 cases were malignant; three cases (all epithelioid type) were originally misdiagnosed as poorly differentiated carcinoma; missed-diagnosis were found in four cases (spindle type) due to the insufficient diagnostic tumor cells. The genetic abnormality detection rate in the biopsy tissue was 38.8% (26/67),among them two patients were lost to follow up after biopsy, 33 patients received surgical resection, 16 cases underwent operation after neoadjuvant therapy and 16 patients with advanced disease underwent continuous imatinib therapy, with the genetic testing rate of 6.1% (2/33), 10/16 and 14/16, respectively. Conclusions: Endoscopic biopsy is a useful but rare method for the preoperative diagnosis of GIST. For majority of biopsy, accurate pathological diagnosis and auxiliary examination can be completed to guide clinical treatment. A thorough history in combination with endoscopic finding is essential to avoid misdiagnosis (epithelioid type) and missed diagnosis (spindle type) in suspicious cases. Genetic testing should be recommended in patients who will undergo targeted therapy after endoscopic biopsy, and it can provide valuable information and guidance for clinical treatment.

Constraints on Sub-GeV Dark Matter-Electron Scattering from the CDEX-10 Experiment.

We present improved germanium-based constraints on sub-GeV dark matter via dark matter-electron (χ-e) scattering using the 205.4 kg·day dataset from the CDEX-10 experiment. Using a novel calculation technique, we attain predicted χ-e scattering spectra observable in high-purity germanium detectors. In the heavy mediator scenario, our results achieve 3 orders of magnitude of improvement for m_{χ} larger than 80 MeV/c^{2} compared to previous germanium-based χ-e results. We also present the most stringent χ-e cross-section limit to date among experiments using solid-state detectors for m_{χ} larger than 90 MeV/c^{2} with heavy mediators and m_{χ} larger than 100 MeV/c^{2} with electric dipole coupling. The result proves the feasibility and demonstrates the vast potential of a new χ-e detection method with high-purity germanium detectors in ultralow radioactive background.

Exotic Dark Matter Search with the CDEX-10 Experiment at China's Jinping Underground Laboratory.

A search for exotic dark matter (DM) in the sub-GeV mass range has been conducted using 205 kg day data taken from a p-type point contact germanium detector of the CDEX-10 experiment at China's Jinping underground laboratory. New low-mass dark matter searching channels, neutral current fermionic DM absorption (χ+A→ν+A) and DM-nucleus 3→2 scattering (χ+χ+A→ϕ+A), have been analyzed with an energy threshold of 160 eVee. No significant signal was found; thus new limits on the DM-nucleon interaction cross section are set for both models at the sub-GeV DM mass region. A cross section limit for the fermionic DM absorption is set to be 2.5×10^{-46} cm^{2} (90% C.L.) at DM mass of 10 MeV/c^{2}. For the DM-nucleus 3→2 scattering scenario, limits are extended to DM mass of 5 and 14 MeV/c^{2} for the massless dark photon and bound DM final state, respectively.

[New understanding about the concept of minimally invasive endoscopic surgery--ERBEC].

As a vital component of gastroenterology and endoscopology, minimally invasive endoscopic surgery has expanded its technology from surface to depth, from inside to outside, from intraluminal to extraluminal lesions, and from organic diseases to functional diseases. This paper summarizes the experience of minimally invasive endoscopic surgery in the recent two decades, and in combination with the current development trend, puts forward understanding about the concept of minimally invasive endoscopic surgery--ERBEC, namely elements, reservation-resection, bilateral-benefit, expansion, collaboration, in order to truly benefit patients through new methods and concepts.

Influence of light supplement on duck sternal calcification from integrated analysis of metabolome and transcriptome.

Calcification of bones is the critical process of bone development in birds, which is very important for sustaining the normal biological function of bones. Light is one of the vital factors affecting bone development, but whether light intensity affects bone calcification and the underlying mechanism is still unknown. In this study, we used duck sternum as a model to analyze the calcification process under different light regimes. In addition, the underlying mechanism was also illustrated by integrating metabolomics and transcriptome methods. The experiment lasted from 14 to 51 d of duck age. The control group (LP1) kept light intensity 2 lx during the whole experiment. The two light supplement groups (LP2, LP3) were given light with the intensity of 70 lx at different time (14-29 d for LP2, 14-43 d for LP3). Samples were collected at 52 d of duck age. Sternal calcification analysis showed no significant difference in proportion of area of cartilage matrix and trabecular bone in keel tissue among the 3 groups, but the degree of keel calcification in LP3 was higher than in the other 2 groups. Serum metabolomics showed 32 and 28 differentially accumulated metabolites (DAMs) in the 2 comparison groups, LP1 vs. LP3 and LP1 vs. LP2, respectively. Carboxylic acids and derivatives were the most abundant among the DAMs. Sternal transcriptome analysis showed 231 differentially expressed genes (DEGs), including 177 upregulated genes and 54 downregulated genes in group LP1 vs. LP3, and 22 DEGs in group LP1 vs. LP2. Protein-protein interaction (PPI) network analysis on DEGs between LP1 and LP3 showed that genes BTRC, GLI1, BMP4, and FOS were in the core position of the interaction network, and are also involved in bone development. KEGG pathway analysis of DAMs and DEGs showed that differences in Hedgehog signaling pathway, MAPK signaling pathway, apoptosis, energy metabolism, and amino acid metabolism following light treatment seem likely to have contributed to the observed difference in calcification of duck sternum.

Effect of different types of sugar on gut physiology and microbiota in overfed goose.

To explored the difference of goose fatty liver formation induced-by different types of sugar from the intestinal physiology and the gut microflora, an integrated analysis of intestinal physiology and gut microbiota metagenomes was performed using samples collected from the geese including the normal-feeding geese and the overfed geese which were overfed with maize flour or overfeeding dietary supplementation with 10% sugar (glucose, fructose or sucrose, respectively), respectively. The results showed that the foie gras weight of the fructose group and the sucrose group was heavier (P < 0.05) than other groups. Compared with the control group, the ileum weight was significantly higher (P < 0.01), and the cecum weight was significantly lower in the sugar treatment groups (P < 0.001). Compared with the control group, the ratio of villi height to crypt depth in the fructose group was the highest in jejunum (P < 0.05); the trypsin activity of the ileum was higher in the fructose group and the sucrose group (P < 0.05). At the phylum level, Firmicutes, Proteobacteria and Bacteroidetes were the main intestinal flora of geese; and the abundance of Firmicutes in the jejunum was higher in the sugar treatment groups than that of the maize flour group. At the genus level, the abundance of Lactobacillus in the jejunum was higher (P < 0.05) in the sugar treatment groups than that of the maize flour group. In conclusion, forced-feeding diet supplementation with sugar induced stronger digestion and absorption capacity, increased the abundance of Firmicutes and Bacteroidetes and the abundance of Lactobacillus (especially fructose and sucrose) in the gut. So, the fructose and sucrose had higher induction on hepatic steatosis in goose fatty liver formation.

Comparison of overfeeding effects on gut physiology and microbiota in two goose breeds.

To have a better understanding of how the "gut-liver axis" mediates the lipid deposition in the liver, a comparison of overfeeding influence on intestine physiology and microbiota between Gang Goose and Tianfu Meat Goose was performed in this study. After force-feeding, compared with Gang Goose, Tianfu Meat Goose had better fat storage capacity in liver (397.94 vs. 166.54 for foie gras weight (g), P < 0.05; 6.37 vs. 2.92% for the ratio of liver to body, P < 0.05; 60.01 vs. 46.64% for fat content, P < 0.05) and the less subcutaneous adipose tissue weight (1240.96 g vs. 1440.46 g, P < 0.05). After force-feeding, the digestion-absorption capacity of Tianfu Meat Goose was higher than that of Gang Goose (5.56 vs. 3.64 and 4.63 vs. 3.68 for the ratio of villus height to crypt depth in duodenum and ileum, respectively, P < 0.05; 1394.96 vs. 782.59 and 1314.76 vs. 766.17 for the invertase activity (U/mg-prot), in duodenum and ileum, respectively, P < 0.05; 6038.36 vs. 3088.29 and 4645.29 vs. 3927.61 for the activity of maltase (U/mg-prot), in duodenum and ileum, respectively, P < 0.05). Force-feeding decreased the gene expression of Escherichia coli in the ileum of Tianfu Meat Goose; force-feeding increased the number of gut microbiota Enterobacterial Repetitive Intergenic Consensus-Polymerase Chain Reaction band in Tianfu Meat Goose and decreased the number in Gang Goose. In conclusion, compared with Gang Goose, the lipid deposition in the liver and the intestine digestion-absorption capacity and stability were higher in Tianfu Meat Goose. Thereby, Tianfu Meat Goose is the better breed for foie gras production for prolonged force-feeding; Gang Goose possesses better fat storage capacity in subcutaneous adipose tissue. However, Gang Goose has lower gut stability responding to force-feeding, so Gang Goose is suited to force-feeding in a short time to gain the body weight and subcutaneous fat as an overfed duck for roast duck.

[Application of a new solid adsorbent tube for the determination of three kinds of epoxy eompounds in air].

Objective: To develop a new solid sorbent tube for simultaneously capturing ethylene oxide (EO) , propylene oxide (PO) and epichlorohydrin (ECH) in air, and establish a complete set of method. Methods: In June 2018, EO, PO and ECH in air were captured by the new solid sorbent tube filled with carbon aerogel adsorbent, desorbed with solution of 5% (V/V) methanol-methylene chloride, separated through capillary chromatographic column, and then analyzed by gas chromatography-flame ionization detector. Results: The linear ranges of EO, PO and ECH were 0.24-960.00, 0.60-2384.00 and 0.12-472.40 mg/L respectively, and the related coefficients were between 0.99995-0.99997. The relative standard deviations (RSD) within the group were 1.66%-4.09%, 1.36%-4.43%, and 1.99%-5.65%, respectively, and the RSD between the group were 2.69%-4.95%, 2.77%-5.30%, and 3.27%-6.67%, respectively. The average desorption efficiencies were 88.25%-94.50%, 98.17%-98.60%, and 97.79%-101.04%, respectively. The samples could be stored at 4 ℃ refrigerator for at least 27 days. Conclusion: The newly developed solid sorbent tube filled with carbon aerogel adsorbent and its complete set of gas chromatography method could be used for sampling and quantitative detection of EO, PO and ECH in workplace air.

Direct Detection Constraints on Dark Photons with the CDEX-10 Experiment at the China Jinping Underground Laboratory.

We report constraints on the dark photon effective kinetic mixing parameter (κ) with data taken from two p-type point-contact germanium detectors of the CDEX-10 experiment at the China Jinping Underground Laboratory. The 90% confidence level upper limits on κ of solar dark photon from 205.4 kg-day exposure are derived, probing new parameter space with masses (m_{V}) from 10 to 300 eV/c^{2} in direct detection experiments. Considering dark photon as the cosmological dark matter, limits at 90% confidence level with m_{V} from 0.1 to 4.0 keV/c^{2} are set from 449.6 kg-day data, with a minimum of κ=1.3×10^{-15} at m_{V}=200 eV/c^{2}.

[The correlation between blood pressure response to cold pressor test and long-term blood pressure changes].

Objective: The aim of the study was to investigate the correlation between blood pressure response to cold pressor test (CPT) and follow-up blood pressure after 8 years in subjects, and to evaluate the predictive value of CPT for long-term blood pressure levels. Methods: A total of 365 individuals from eight natural villages were enrolled by stratified cluster sampling from Mei County, Shaanxi Province in 2004. Baseline characteristics of subjects were collected and CPTs were conducted. Subjects were followed up in 2009 and 2012, respectively. According to the maximal change of systolic response (SR), the area under the curve (AUC) of systolic blood pressure change (AUC-SBP), the maximal change of diastolic response (DR) and the AUC of diastolic blood pressure change (AUC-DBP) in CPT, the individuals were divided into four quartile groups by above parameters, respectively: group Ⅰ (P(25)), group Ⅱ (P(50)), group Ⅲ (P(75)) and group Ⅳ (P(100)). The correlation between blood pressure response to CPT and the follow-up blood pressure was analyzed. Results: (1) There were no significant differences in baseline blood pressure levels and prevalence of hypertension among four quartile groups no matter it was grouped on SR, DR, AUC-SBP or AUC-DBP. (2) The prevalence of hypertension in each group from lowest (P(25)) to highest (P(100)) in 2012 was 25.64%, 30.67%, 38.03%, 55.74% on SR grouping (P<0.01), and 27.5%, 29.17%, 38.46%, 57.35% on AUC-SBP grouping (P<0.05), respectively. (3) There were no significant differences in the prevalence of hypertension among four groups in 2012 (P>0.05) either on DR or on AUC-DBP grouping. (4) The random effects model analysis showed that the correlation coefficient between SR, AUC-SBP and long-term systolic blood pressure increase were 1.91 (P<0.05) and 1.44 (P<0.05), respectively, and the correlation coefficient between DR, AUC-DBP and long-term diastolic blood pressure increase were 0.82 (P<0.05) and 0.78 (P>0.05), respectively. Age, male, body mass index, and fasting blood glucose were independent risk factors for long-term blood pressure elevation, and age, body mass index and fasting blood glucose positively correlated with changes in long-term blood pressure (all P<0.05). Conclusion: Individual systolic blood pressure response to CPT can be used as a predictor of long-term hypertension.

[A novel and simplified closure method for defect closure after endoscopic full-thickness resection of gastric submucosal tumors: short-term outcomes of "Shao-Mai" closure method].

Objective: To evaluate the feasibility and short-term efficacy of a novel and simplified closure method developed by our team for the defect closure after endoscopic full-thickness resection (EFTR) for gastric submucosal tumors (SMT) in the gastric wall. Methods: A prospective single-arm clinical study was used. Inclusion criteria: (1) the lesion was located in the fundus or the greater curvature of the stomach, and was confirmed to originate from the muscularis propria layer; (2) the diameter of the tumor was ≤3.5 cm, and the tumor had no extensive adhesion to the peritoneal tissues and organs in extraperitoneal cavity; (3) the tumor had no malignant features under ultrasound endoscopy; (4) the patient agreed to participate in the study; (5) patients with severe complications were excluded. Based on the above criteria, 20 patients with gastric SMT at the Endoscopy Center of Zhongshan Hospital of Fudan University from January 2015 to March 2018 were enrolled in this study, including 5 males and 15 females with mean age of 61.1 (38 to 70) years. Grasping forceps-assisted endo-loop snare ligation device which is called "Shao-Mai" method was used to close the defect site. All the patients underwent EFTR and "Shao-Mai" method to perform defect closure. After successful tumor resection by EFTR, an endo-loop was anchored onto the edge of the gastric defect with grasping forceps assistance and closed tightly. The observation indicators included tumor size, en bloc resection, operation time, postoperative complications and hospital stay. The follow-up indicators included tumor residual, local recurrence, and metachronous lesions. Results: All the 20 lesions were located in the muscularis propria with a size of 0.5-3.5 (mean 1.4) cm. Three of them were located in the greater curvature of the mid-upper gastric body, 17 were located in the fundus. The endoscopic "Shao-Mai" closure was successfully performed after EFTR in all the 20 cases. Endoscope was used uniquely through the entire process, without laparoscopic assistance. The operative time was 20-100 (mean 43.8) minutes, while the "Shao-Mai" closure procedure took a range of 3-30 (mean 10.1) minutes. The en bloc resection rate was 100%. The pathological diagnosis included 17 gastrointestinal stromal tumors and 3 leiomyomas. No major complications occurred during or after surgery. All the patients were discharged 1-11 (mean 3.1) days after operation. The wounds of all the cases were healed completely six months after operation and only scar was observed without ulcer. No residual lesion, tumor recurrence or metastasis, leakage or fistula of digestive tract were found during the follow-up period of 15-54 (median 41) months. Conclusion: The endoscopic "Shao-Mai" closure method is a simplified novel way, which is feasible, effective, and safe for closing the gastric defect after EFTR.

[Comparison of the clinical characteristics between RNA positive and negative patients clinically diagnosed with coronavirus disease 2019].

Objective: To raise awareness about 2019 novel coronavirus pneumonia (NCP) and reduce missed diagnosis rate and misdiagnosis rate by comparing the clinical characteristics between RNA positive and negative patients clinically diagnosed with NCP. Methods: From January 2020 to February 2020, 54 patients who were newly diagnosed with NCP in Wuhan Fourth Hospital were included in this study. RT-PCR method was used to measure the level of 2019-nCov RNA in pharyngeal swab samples of these patients. The patients were divided into RNA positive and negative group, and the differences of clinical, laboratory, and radiological characteristics were compared. Results: There were 31 RNA of 2019-nCov positive cases, and 23 negative cases. Common clinical symptoms of two groups were fever (80.64% vs. 86.96%) , chills (61.29% vs. 52.17%) , cough (80.64% vs. 95.65%) , fatigue (61.30% vs. 56.52%) , chest distress (77.42% vs.73.91%) . Some other symptoms were headache, myalgia, dyspnea, diarrhea, nausea and vomiting. The laboratory and radiological characteristics of two groups mainly were lymphopenia, increased erythrocyte sedimentation rate, increased C-reactive protein, increased lactate dehydrogenase, decreased oxygenation index, normal white blood cell count and bilateral chest CT involvement. There was no statistically significant difference in other clinical characteristics except for dyspnea between two groups. Conclusions: RNA positive and negative NCP patients shared similar clinical symptoms, while RNA positive NCP patients tended to have dyspnea. Therefore, we should improve the understanding of NCP to prevent missed diagnosis and misdiagnosis; In addition, more rapid and accurate NCP diagnostic approaches should be further developed.

Search for Light Weakly-Interacting-Massive-Particle Dark Matter by Annual Modulation Analysis with a Point-Contact Germanium Detector at the China Jinping Underground Laboratory.

We present results on light weakly interacting massive particle (WIMP) searches with annual modulation (AM) analysis on data from a 1-kg mass p-type point-contact germanium detector of the CDEX-1B experiment at the China Jinping Underground Laboratory. Datasets with a total live time of 3.2 yr within a 4.2-yr span are analyzed with analysis threshold of 250 eVee. Limits on WIMP-nucleus (χ-N) spin-independent cross sections as function of WIMP mass (m_{χ}) at 90% confidence level (C.L.) are derived using the dark matter halo model. Within the context of the standard halo model, the 90% C.L. allowed regions implied by the DAMA/LIBRA and CoGeNT AM-based analysis are excluded at >99.99% and 98% C.L., respectively. These results correspond to the best sensitivity at m_{χ}<6 GeV/c^{2} among WIMP AM measurements to date.

Constraints on Spin-Independent Nucleus Scattering with sub-GeV Weakly Interacting Massive Particle Dark Matter from the CDEX-1B Experiment at the China Jinping Underground Laboratory.

We report results on the searches of weakly interacting massive particles (WIMPs) with sub-GeV masses (m_{χ}) via WIMP-nucleus spin-independent scattering with Migdal effect incorporated. Analysis on time-integrated (TI) and annual modulation (AM) effects on CDEX-1B data are performed, with 737.1 kg day exposure and 160 eVee threshold for TI analysis, and 1107.5 kg day exposure and 250 eVee threshold for AM analysis. The sensitive windows in m_{χ} are expanded by an order of magnitude to lower DM masses with Migdal effect incorporated. New limits on σ_{χN}^{SI} at 90% confidence level are derived as 2×10^{-32}∼7×10^{-35} cm^{2} for TI analysis at m_{χ}∼50-180 MeV/c^{2}, and 3×10^{-32}∼9×10^{-38} cm^{2} for AM analysis at m_{χ}∼75 MeV/c^{2}-3.0 GeV/c^{2}.

[Application value of dual channel dual curved endoscope in the endoscopic submucosal dissection for gastric angle mucosal lesions].

Objective: To evaluate the clinical value of dual channel dual curved endoscope in the endoscopic submucosal dissection (ESD) for gastric angle mucosal lesions. Methods: A descriptive cohort study was carried out. Clinicopathological data of 20 cases with gastric angle mucosal lesions undergoing ESD by dual channel dual curved endoscope in our center from October 2016 to August 2018 were collected and analyzed retrospectively. Inclusion criteria: (1) the lesion was located in the gastric angle confirmed by gastroscopy before ESD. (2) CT examination showed no distant metastasis. (3) pathological biopsy confirmed precancerous lesion or early cancerous lesion without submucosal invasion. (4) the whole operation was performed by the same endoscopist with ESD experience of about 2000 cases. Patients with previous ESD history of gastric angle and other serious diseases were excluded. The dual channel dual curved endoscopy (Olympus, GIF-2TQ260M) and other conventional endoscopic surgical instruments were used in all the cases. Complete tumor resection rate, pathological results, intraoperative and postoperative complications, operation time and hospitalization time were observed. Follow - up parameters included residual tumor, local recurrence and heterogeneous lesion. Results: Of 20 patients, 14 were male and 6 were female with an average of 55.6 years (range, 37 to 75). All the tumors located in gastric angle. Specimen size ranged from 1.2 to 5.5 (average 2.9) cm. Operation time ranged from 50 to 120 (average 85.8) minutes. Hospital stay ranged from 3 to 7 (average 5.1) days. The en bloc excision was performed successfully in all 20 cases. There was no perforation or bleeding during or after operation. Pathological results showed curative or nearly curative resection stage in all the cases. No tumor residual or recurrence was found during follow-up for 8 to 30 (average 18.5) months. Conclusion: Dual channel dual curved endoscope can provide good vision and easy control in removing the lesion completely and avoiding complications during the ESD procedure in gastric angle mucosal lesions with good long-term efficacy.

[Simultaneous determination of four kinds methyl acrylate compounds in workplace air].

Objective: To develop a solvent desorption-gas chromatography method for simultaneous determination of methyl methacrylate (MMA) , ethyl methacrylate (EMA) , n-propyl methacrylate (PMA) and butyl methacrylate (BMA) in workplace air. Methods: MMA, EMA, PMA and BMA in workplace air were captured by charcoal tubes and desorbed with carbon disulfide, separated through capillary chromatographic column, and then analyzed by gas chromatography-flame ionization detector. Results: The linear ranges of MMA, EMA, PMA and BMA were 0-8 305.00 mg/L, 0-9 080.50 mg/L, 0-8 899.00 mg/L and 0-8 371.00 mg/L respectively, and the related coefficients were between 0.999 96-0.999 98. The relative standard deviations (RSD) within the group were 0.56%-1.71%, 0.45%-1.65%, 0.51%-1.49% and 0.45%-1.50% respectively, and the RSD between the group were 1.14%-2.79%, 0.79%-2.13%, 0.93%-2.30% and 1.09%-2.84% respectively. The average desorption efficiencies were 95.76%-99.58%, 97.82%-102.28%, 98.55%-102.28%and 98.70%-102.40% respectively. The minimum quantification concentrations were 0.12 mg/m(3), 0.10 mg/m(3), 0.07 mg/m(3) and 0.07 mg/m(3) respectively (3.00 L sample) . The samples could be stored at room temperature for at least 7 days. Conclusion: This method could be used for monitoring of MMA, EMA, PMA and BMA in workplace air.