Peta-electron volt gamma-ray emission from the Crab Nebula

The Crab Nebula is a bright source of gamma rays powered by the Crab Pulsar's rotational energy through the formation and termination of a relativistic electron-positron wind. We report the detection of gamma rays from this source with energies from 5 × 10^-4 to 1.1 peta-electron volts with a spectrum showing gradual steepening over three energy decades. The ultrahigh-energy photons imply the presence of a peta-electron volt electron accelerator (a pevatron) in the nebula, with an acceleration rate exceeding 15% of the theoretical limit. We constrain the pevatron's size between 0.025 and 0.1 parsecs and the magnetic field to ≈110 microgauss. The production rate of peta-electron volt electrons, 2.5 × 10³⁶ ergs per second, constitutes 0.5% of the pulsar spin-down luminosity, although we cannot exclude a contribution of peta-electron volt protons to the production of the highest-energy gamma rays.

[Common drugs that cause abnormalities in the thyroid gland functions and their impact on levels of serum biomarkers]

The abnormal thyroid function in the duration of drug treatment has attracted increasing attention, these drugs included traditional drugs, such as glucocorticoid, nonsteroidal anti-inflammatory drug, iodine agent, etc.; also included new types of drugs, such as immune checkpoint inhibitors. The possible reasons causing abnormality of thyroid biomarkers included drugs' toxicity on thyroid, drug-drug interaction affecting synthetic thyroid hormones therapy, and drug's interference on biomarkers' measurement. This article focused on the influence and mechanisms of common drugs on the regulation, synthesis, release, transport and metabolism of thyroid hormones. Here also briefly introduced the mechanism of drug-drugs interaction on the effect of synthetic thyroid hormone; the interference and mechanism of some drugs on the laboratory measurement was also included. The aim of this article was to strengthen clinician's understanding on drug-induced thyroid diseases and to be alert to drugs' interference on the in-vitro measurement of biomarkers.

Extended Very-High-Energy Gamma-Ray Emission Surrounding PSR J0622+3749 Observed by LHAASO-KM2A

We report the discovery of an extended very-high-energy (VHE) gamma-ray source around the location of the middle-aged (207.8 kyr) pulsar PSR J0622+3749 with the Large High-Altitude Air Shower Observatory (LHAASO). The source is detected with a significance of 8.2σ for E>25  TeV assuming a Gaussian template. The best-fit location is (right ascension, declination) =(95.47°±0.11°,37.92°±0.09°), and the extension is 0.40°±0.07°. The energy spectrum can be described by a power-law spectrum with an index of -2.92±0.17_{stat}±0.02_{sys}. No clear extended multiwavelength counterpart of the LHAASO source has been found from the radio to sub-TeV bands. The LHAASO observations are consistent with the scenario that VHE electrons escaped from the pulsar, diffused in the interstellar medium, and scattered the interstellar radiation field. If interpreted as the pulsar halo scenario, the diffusion coefficient, inferred for electrons with median energies of ∼160  TeV, is consistent with those obtained from the extended halos around Geminga and Monogem and much smaller than that derived from cosmic ray secondaries. The LHAASO discovery of this source thus likely enriches the class of so-called pulsar halos and confirms that high-energy particles generally diffuse very slowly in the disturbed medium around pulsars.

[Risk factors and clinical prognosis analysis of carbapenem-resistant Enterobacterales bacteria nosocomial infection]

Objective: To explore the risk factors for carbapenem-resistant Enterobacterales (CRE) infection and death. Methods: A case-control analysis of 482 inpatients in 18 secondary or tertiary hospitals in Beijing in 2018 was conducted. Patients infected by CRE were selected as the case group (n=247), and infected by carbapenem susceptible Enterobacterales (CSE) as the control group (n=235). The risk factors and clinical prognosis of CRE infection were analyzed by single factor analysis and multivariate logistic regression analysis. Results: CRE were resistant to most antimicrobials, but were highly sensitive to colistin and tigecycline, with sensitivity of 94.0% and 99.5%, respectively. Multivariate analysis showed that prior 30-day tracheal intubation (OR=2.607, 95%CI: 1.655-4.108, P<0.001), empirical treatment using third or fourth generation cephalosporins (OR=2.339, 95%CI: 1.438-3.803, P=0.001), carbapenems (OR=2.468, 95%CI: 1.610-3.782, P<0.001) and quinolones (OR=2.042, 95%CI: 1.268-3.289, P=0.003) were independent risk factors for CRE infection. Mechanical ventilation (OR=3.390, 95%CI: 1.454-7.904, P=0.005), heart failure (OR=4.679, 95%CI: 1.975-11.083, P<0.001), moderate or severe liver disease (OR=3.057, 95%CI: 1.061-8.806, P=0.038), prior 30-day quinolones exposure (OR=2.882, 95%CI: 1.241-6.691, P=0.014) and septic shock (OR=7.772, 95%CI: 3.505-17.233, P<0.001) were independent risk factors for death after CRE infection. Conclusions: Reducing the use of antimicrobials and invasive procedures such as prior 30-day tracheal intubation may reduce the probability of CRE infection. Grading the severity of the underlying disease in patients with CRE infection, as well as predicting and preventing the occurrence of septic shock will help reduce the risk of death.

Ultrahigh-energy photons up to 1.4 petaelectronvolts from 12 γ-ray Galactic sources

The extension of the cosmic-ray spectrum beyond 1 petaelectronvolt (PeV; 10¹⁵ electronvolts) indicates the existence of the so-called PeVatrons-cosmic-ray factories that accelerate particles to PeV energies. We need to locate and identify such objects to find the origin of Galactic cosmic rays¹. The principal signature of both electron and proton PeVatrons is ultrahigh-energy (exceeding 100 TeV) γ radiation. Evidence of the presence of a proton PeVatron has been found in the Galactic Centre, according to the detection of a hard-spectrum radiation extending to 0.04 PeV (ref. ²). Although γ-rays with energies slightly higher than 0.1 PeV have been reported from a few objects in the Galactic plane^3-6, unbiased identification and in-depth exploration of PeVatrons requires detection of γ-rays with energies well above 0.1 PeV. Here we report the detection of more than 530 photons at energies above 100 teraelectronvolts and up to 1.4 PeV from 12 ultrahigh-energy γ-ray sources with a statistical significance greater than seven standard deviations. Despite having several potential counterparts in their proximity, including pulsar wind nebulae, supernova remnants and star-forming regions, the PeVatrons responsible for the ultrahigh-energy γ-rays have not yet been firmly localized and identified (except for the Crab Nebula), leaving open the origin of these extreme accelerators.

[Analysis of gut microbiome in patients with lung adenocarcinoma and lung squamous cell carcinoma]

To investigate the diversity and composition of gut microbiota in patients with lung adenocarcinoma and lung squamous cell carcinoma. A single-center and case-control study was conducted to consecutively enroll a total of 27 lung cancer patients, including 15 males and 12 females, who were seen at the Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine between September 2018 to October 2020. A total of 20 cases of healthy healthy physical examiners, including 9 males and 11 females were recruited as healthy control group (HC) during the same period. Clinical data and stool samples were collected from each participants, and lung cancer patients were divided into lung adenocarcinoma group (AC, 19 patients, 8 males and 11 females) and lung squamous cell carcinoma group (SCC, 8 patients, 7 males and 1 females) according to the pathology type. Genomic DNA were extracted to amplify 16S rDNA V3-V4 region, then the Illumina MiSeq high-throughput sequencing platform and QIIME software were used for sequencing and analyzing the structure of the gut microbiota, respectively. Analysis of variance, χ² test, K-W test were used to analyze the differences in age, gender,α diversity, and relative abundance of microbiota among the three groups. AC, SCC, and HC were aged (58.74±9.27), (63.38±6.12), and (55.65±7.79) years old, respectively. There were no difference in gender and age among the three groups (gender and age are respectively:χ²=5.155, P=0.076;F=2.598,P=0.086). And no significant difference in alpha diversity were found among the three groups (Chao and Shannon index were respectively: F=0.616, P=0.545; F=2.484, P=0.095), while β-diversity analysis indicated significant differences in the structure of intestinal flora among AC, SCC and HC (P=0.001). LEfSe analysis showed that AC and SCC both have dominant bacterials. Megasphaera (H=7.855,P=0.020) and Erysipelatoclostridium (H=7.426,P=0.024) were enriched in patients with AC, while Enterococcus (H=8.400, P=0.015), Veillonella (H=9.957,P=0.007), and Eubacterium_eligens_group (H=10.514,P=0.005) were enriched in patients with SCC. Lung cancer patients have gut microbiota imbalance, while lung adenocarcinoma and lung squamous cell carcinoma patients have no significant difference in gut microbiota diversity, but lung adenocarcinoma and lung squamous cell carcinoma have their own unique microbiota. This imbalance of the intestinal microenvironment is of great significance for studying the occurrence and development of different pathological types of lung cancer.

[A preliminary investigation on a deep learning convolutional neural networks based pulmonary tuberculosis CT diagnostic model]

Objective: To evaluate the clinical value of a pulmonary tuberculosis CT diagnostic model based on deep learning convolutional neural networks (CNN). Methods: From March 2017 to March 2018,a total of 1 764 patients with positive sputum for tuberculous bacterium and had received high-resolution chest CT scan in radiology department of Hebei province chest hospital were enrolled. Among them, 937 were male, and 827 were female, aging from 17-73 years (average 38.4). A total of 20 139 CT images (17 kinds of image features) classified by 4 radiologists were used as training dataset to create a tuberculosis CT CNN diagnostic model. The top 5 image features in training set were: infiltrative pulmonary tuberculosis, cavitary pulmonary tuberculosis, pleural thickening, caseous pneumonia and pleural effusion. A total of 302 images were randomly selected from the marked images as testing dataset. The diagnosis of 2 senior radiologists was taken as "golden standard". The differences of sensitivity and accuracy in CT diagnosis between the CNN diagnostic model and the radiologists were compared. The classification error types and numbers of the CNN diagnostic model were recorded. FROC(free response operating characteristic curve)curve was drawn and the highest diagnostic efficiency of the model was measured. Results: The diagnostic accuracy of infiltrative pulmonary tuberculosis, cavitary pulmonary tuberculosis, pleural thickening, caseous pneumonia and pleural effusion by the CNN diagnostic model were 95.33%(10 982/11 520), 73.68%(2 151/2 920), 73.07%(1 128/1544), 83.33%(1 020/1225)and 94.11%(814/865), respectively. The overall diagnostic sensitivity and accuracy of the CNN model were 95.49%(339/355)and 90.40%(339/375), respectively, and the corresponding values ​​of radiologists were 93.80%(348/371)and 92.80%(348/375), respectively, and there was no statistical difference between the CNN model and the radiologists(sensitivity χ²=1.022,P=0.312;accuracy χ²=1.404,P=0.236). FROC curve showed that when sensitivity of the CNN model was 78% and FPI value was 2.48, it reached the highest diagnostic efficiency. The classification error of CNN diagnostic models was mainly confusion of fiber stripe components, cavitary pulmonary tuberculosis, caseous pneumonia and infiltrative pulmonary tuberculosis. Conclusions: The CNN-based pulmonary tuberculosis CT diagnostic model exhibited high sensitivity and accuracy (95.49% and 90.40% respectively). It could assist radiologists in CT diagnosis of pulmonary tuberculosis and deserve further clinical application.

[Construction of artificial neural network model for predicting the efficacy of first-line FOLFOX chemotherapy for metastatic colorectal cancer]

Objective: To explore and establish an artificial neural network (ANN) model for predicting the efficacy of first-line FOLFOX chemotherapy for metastatic colorectal cancer. Methods: A set of FOLFOX chemotherapy data from a group of patients with metastatic colorectal cancer (mCRC) (GSE104645) was downloaded from the GEO database as a training set. According to the FOLFOX protocol, the efficacy was divided into two groups: the chemo-sensitive group (including complete response and partial response) and the chemo-resistant group (including stable disease and progressive disease), including 31 cases in the sensitive group and 23 in the resistant group. Then, chip data (accessible number: GSE69657) from Fujian Medical University Union Hospital were chosen as a test set. A total of 30 patients were enrolled in the study, including 13 in the sensitive group and 17 in the resistant group. The batch effect correction was performed on the expression values of the two sets of matrices using the R 3.5.1 software Combat package. The gene expression difference of sensitive and resistant group in GSE104645 was analyzed by the GEO2R platform. P<0.05 and the absolute value of log(2)FC>0.33 (FC abbreviation of fold change) were used as the threshold value to screen the drug resistance and sensitive genes of the FOLFOX regimen. An ANN was constructed using the multi-layer perceptron (MLP) to perform the FOLFOX regimen on the GSE104645 dataset. The GSE69657 expression matrix and clinical efficacy parameters were then used for retrospective verification. Receiver operating characteristic(ROC) curves were used to evaluate the test results and predictive power. Results: A total of 2, 076 differentially expressed genes in GSE104645 were selected, of which 822 genes were up-regulated and 1, 254 genes were down-regulated in the chemo-resistance group. The down-regulated genes were sensitive genes. GO analysis of the biological processes in which the differentially expressed genes were involved, revealed that they were mainly involved in the regulation of substance metabolism. A total of 39 genes were included in the final model construction. This was a neural network model with two hidden layers. The accuracy of predicting training samples and test samples was 75.7% and 76.5%, respectively, and the area under the ROC curve was 0.875. The chip data set of our department (GSE69657) was set as the test set, and the area under the ROC curve was 0.778. Conclusions: In this study, an artificial neural network model is successfully constructed to predict the efficacy of first-line FOLFOX regimen for metastatic colorectal cancer based on the microarray, and an independent external verification is also conducted. The model has good stability and well prediction efficiency. Besides, the results of this study suggest that the gene functions related to oxaliplatin resistance are mainly enriched in the regulation process of substance metabolism.

[Clinical characteristics and survival analysis of primary intestinal extranodal NK/T-cell lymphoma, nasal type]

Objective: To retrospectively analyze the clinical features and survival analysis of primary intestinal extranodal NK/T-cell lymphoma nasal type(ENKTL). Methods: Patients with intestinal lymphoma at the First Affiliated Hospital of Air Force Military Medical University were collected from January 2009 to December 2019, and those with primary intestinal ENKTL screened. The general situation, main symptoms, ECOG scale, lactic dehydrogenase(LDH), and β(2)-microglobulin(β(2)-MG)in the serum, lesion site and form, numbers of extranodal invasion, Lugano stage, pathological features, and lifetime and survival outcomes were evaluated. Results: In total, 34 patients with confirmed diagnosis of primary intestinal ENKTL were identified. The incidence rate of primary intestinal ENKTL is 16.2% (34/210). A total of 26 patients were men and 8 were women with the median age at diagnosis of 45 (range, 20-69)years and patients younger than 60 years account for 85.3%. It included abdominal pain (76.5%), diarrhea(20.6%), hematochezia(29.4%), and abdominal mass(2.9%), 85.3% with B-symptoms, and abnormally elevated LDH in the serum(73.5%). The lesion sites included large intestine(52.9%), small intestine(29.4%), and both of them(17.7%). The lesion forms were featured by mass(8.8%), ulcer(32.4%), diffuse infiltration(2.9%), and hybrid(55.9%). Lugano stage included stage Ⅰ/Ⅱ (70.6%)24 patients and stage Ⅳ(29.4%)10 patients. About 94.1% patients were EBER positive. The median survival time was 60 days. The overall survival rate had significant differences on ECOG scale, LDH in the serum, IPI score and complications(P=0.037, 0.009, 0.002, and 0.000, respectively). Conclusion: Primary intestinal ENKTL was commonly observed in men at young or middle age, and the most common symptom was abdominal pain, often with B-symptoms, abnormally elevated LDH in the serum. The most common site was the large intestine. The lesion forms were mainly featured by the hybrid and ulcer. It seemed that patients with IPI low-risk group and without any complication would have longer survival time.

Astragalus membranaceus root supplementation improves average daily gain, rumen fermentation, serum immunity and antioxidant indices of Tibetan sheep

The use of antibiotics as supplements in animal feed is restricted due to possible health hazards associated with them. Consequently, there is increasing interest in exploiting natural products to improve health and production of livestock with no detrimental side effects. In this study, we examined the effect of Astragalus membranaceus root (AMT) supplementation on DM intake, growth performance, rumen fermentation and immunity of Tibetan sheep. Twenty-four male Tibetan sheep (31 ± 1.4 kg; 9 months old) were assigned randomly to one of four dietary treatments with different levels of AMT: 0, 20, 50 and 80 g/kg DM (A₀, A₂, A₅ and A₈, respectively) in addition to their basal diets. A₀ acted as a control group, and measurements were recorded over a 56-d feeding period. Sheep fed with AMT had a higher average daily gain and a lower feed:gain ratio than controls (P < 0.001). Rumen concentrations of NH₃-N (P < 0.001), total volatile fatty acids (P = 0.028), acetate (P = 0.017) and propionate (P = 0.031) in A₅ and A₈ were higher than those in A₀. The addition of AMT in the feed significantly increased serum antioxidant and immunity factors of the sheep and increased the concentrations of serum interleukin, immunoglobulin and tumour necrosis factor-α (P = 0.010). We concluded that AMT can be used as a feed additive to improve growth performance and rumen fermentation and enhance the immunity of Tibetan sheep. Some responses exhibited a dose-dependent response, whereas other did not exhibit a pattern, with an increase in AMT. The addition of 50 and 80 g/kg AMT of total DM intake showed the most promising results.

[Perinatal outcomes of dichorionic triamniotic triplet pregnancy]

Objective: To analyze the perinatal outcomes in different methods of multifetal pregnancy reduction in dichorionic triamniotic (DCTA) triplet pregnancy. Methods: A retrospective analysis was performed on 57 cases of DCTA triplets in Peking University Third Hospital from January 1, 2010 to January 1, 2020, including 27 cases in expectant pregnancy group and 30 cases in selective fetal reduction (FR) group. The selective FR group was further divided into 3 subgroups according to different FR methods:retaining monochorionic dichorionic (MCDA) group, retaining dichorionic dichorionic (DCDA) group, and retaining singleton group. The perinatal outcomes of expectant pregnancy group and 3 subgroups of selective FR group were compared. Results: The gestational weeks in selective FR group was (34.5±5.7) weeks, and full-term delivery rate was 53% (16/30), respectively higher than those of the expectant pregnancy group (29.9±6.0) weeks and 7% (2/27). The miscarriage rate of the selective FR group was 10% (3/30), lower than that of the expectant pregnancy group (33%, 9/27). The differences between the two groups were statistically significant (all P<0.05). The ratios of pregnancy complications and newborn admission to neonatal ICU (NICU) in the selective FR group were lower than those of the expectant pregnancy group (all P<0.05). In the selective FR group, the gestational weeks in retaining MCDA group (6 cases), retaining DCDA group (13 cases), and retaining singleton group (11 cases) were (32.2±4.3), (33.0±6.3), and (37.4±4.7) weeks; the miscarriage rates were 1/6, 1/13, and 1/11; the premature delivery rates were 4/6, 7/13, and 0/11; the full-term delivery rates were 1/6, 5/13, and 10/11; pregnancies with at least 1 survivor rates were 5/6, 12/13, and 10/11; NICU occupancy rates were 6/8, 9/18 and 0/10, respectively. The retaining singleton group had the highest rate of full-term delivery and the lowest rate of NICU occupancy. Compared with other groups, the differences were statistically significant (all P<0.05). The full-term delivery rate was significantly higher in the retaining DCDA group than that of the expectant pregnancy group (P<0.05). Conclusions: The risk of DCTA triplet pregnancy is high. Reduction of the MCDA pair to singleton has the highest rate of full-term delivery and the lowest rate of NICU occupancy. For pregnant women who wish to retain twin pregnancy, the risk should be fully informed, and consider reduction of one fetus of the MCDA and retaining DCDA twins to continue pregnancy.

[Phase Ⅲ randomized controlled, multicenter, prospective study of recombinant anti-HER2 humanized monoclonal antibody (Cipterbin) combined with vinorelbine in patients with HER2 positive metastatic breast cancer: the HOPES Study]

Objective: To evaluate the clinical efficacy and safety of recombinant anti-HER2 humanized monoclonal antibody (Cipterbin) combined with vinorelbine in patients with HER2 positive metastatic breast cancer. Methods: Patients were randomized 2∶1 to test group and control group. Patients in test group received Cipterbin (4 mg/kg loading dose and 2 mg/kg maintenance dose each week, IV) combined with vinorelbine (25 mg/m(2) on days 1,8 and 15 of each 28 days, IV). Patients in control group received vinorelbine (25 mg/m(2) on days 1,8 and 15 of each 28 days, IV).The primary end point was progression free survival (PFS). Results: A total of 315 patients were enrolled from Jan 2009 to Jan 2013 (212 in test group and 103 in control group). The median PFS of test group was significantly longer than that of control group, 39.1 weeks vs 14.0 weeks (HR=0.24; 95%CI, 0.16-0.36; P<0.000 1). The objective response rate (ORR) and disease control rate (DCR) in test group were significantly higher than those in control group, ORR was 46.7% vs 18.45% (P<0.000 1) and DCR was 79.72% vs 45.63% (P<0.000 1). The incidence of neutropenia, leucopenia and erythrocytopenia were higher in both groups, but there was no significant difference between two groups.The most common adverse events associated with Cipterbin were infusion reactions. Left ventricular ejection fraction reduced to less than 50% in 5 patients, which were recovered. No serious cardiotoxicity. Conclusion: The recombinant anti-HER2 humanized monoclonal antibody (Cipterbin) combined with vinorelbine has significant efficacy and good safety. It is the optimized therapy regime for patients with taxane-pretreated HER2 positive metastatic breast cancer, which provides more targeted therapy opportunities for HER2 positive breast cancer patients in China.

[Prevalence and risk factors of pterygium in Han and Yugur populations in Gansu Province, China]

Objective: To investigate the prevalence and risk factors of pterygium in Han and Yugur populations aged 40-79 years in Gansu Province, China. Methods: This was a cross-sectional study. A multistage cluster sampling method with urbanization level-based stratification was employed. Multiple logistic regression analysis was performed to evaluate the risk factors of pterygium. Results: A total of 4 193 people (1 840 males, 2 353 females; 3 035 Hans, 1 158 Yugurs) aged over 40 in Gansu Province were included in the study. Among them, 391 patients (9.3%) were found to have pterygium. The prevalence of pterygium adjusted for age and sex was 9.3%. The prevalence rates of Han and Yugur participants were 8.8% (267 patients) and 10.7% (124 patients), respectively, and there was no significant difference between them (χ²=3.629, P=0.057). Multivariate regression analysis showed that the risk factors of pterygium included age (OR=3.66, 95%CI: 2.26-5.92), length of residence in the countryside (OR=2.18, 95%CI: 1.41-3.38), and education level (OR=0.49, 95%CI: 0.29-0.83). In the Han group, the risk factors of pterygium were age (OR=3.84, 95%CI: 2.18-6.78) and length of rural residence (OR=2.02, 95%CI: 1.23-3.33), and a higher level of education (OR=0.36, 95%CI: 0.20-0.66) was a protective factor. Older age (OR=3.11, 95%CI: 1.13-8.59) and rural residential length ratio (OR=3.28, 95%CI: 1.09-9.88) were risk factors for pterygium in Yugur population. Conclusions: The overall prevalence of pterygium in Han and Yugur populations aged over 40 in Gansu Province, China was 9.3%, with no significant difference between the two nationalities. Older age and rural residency increased the incidence of pterygium, and a higher education level was a protective factor for pterygium.(Chin J Ophthalmol, 2020, 56:600-607).

[Clinical characteristics and death risk factors of severe COVID-19]

Objective: To analyze the clinical features and death-related risk factors of COVID-19. Methods: We enrolled 891 COVID-19 patients admitted to the Affiliated Hospital of Jianghan University from December 2019 to February 2020, including 427 men and 464 women. Of the 891 cases, 582 were severe or critical, including 423(73%)severe and 159 (27%) critical cases. We compared the demographics, laboratory findings, clinical characteristics, treatments and prognosis data of the 582 severe patients. Univariate and multivariate logistic regression analysis was conducted to explore the risk factors associated with death in COVID-19 patients. Results: The 582 severe patients included 293 males and 289 females, with a median age of 64(range 24 to 106). Sixty-three patients died, including 45 males and 18 females, with a median age of 71(range 37 to 90). The average onset time of the 582 patients was 8 days, of whom 461 (79%) had fever, 358 (62%) dry cough, 274 (47%) fatigue. There were 206 cases with shortness of breath (35%), 155 cases with expectoration (27%), 83 cases with muscle pain or joint pain (14%), 71 cases with diarrhea (12%), and 29 cases with headache (4%). Underlying diseases were present in 267 (46%) patients, most commonly hypertension (194, 33%), followed by diabetes (69, 12%), coronary atherosclerotic heart disease (37, 6%), tumor (18, 3%), and chronic obstructive pulmonary disease (5, 1%). Chest CT showed bilateral lung involvement in 505 patients (87%). Upon admission, the median lymphocyte count of the 582 patients was 0.8(IQR, 0.6-1.1)×10(9)/L, the median D-dimer was 0.5 (IQR, 0.4- 0.8) mg/L, the median N-terminal brain natriuretic peptide precursor (NT-proBNP) was 433 (IQR, 141- 806) pg/L, and the median creatinine was 70.3 (IQR, 56.9-87.9) μmol/L. The death group had a median lymphocyte count of 0.5 (0.4-0.8)×10(9)/L, D-dimer 1.1 (0.7-10.0)mg/L, N-terminal brain natriuretic peptide precursor 1479(893-5 087) pg/ml, and creatinine 89.9(67.1-125.3) μmol/L. Multivariate logistic analysis showed that increased D-dimer (OR: 1.095, 95% CI: 1.045-1.148, P<0.001), increased NT-proBNP (OR: 4.759, 95% CI: 2.437-9.291, P<0.001), and decreased lymphocyte count (OR: 0.180, 95% CI: 0.059-0.550, P=0.003) were the risk factors of death in COVID-19 patients. Conclusions: The average onset time of severe COVID-19 was 8 days, and the most common symptoms were fever, dry cough and fatigue. Comorbidities such as hypertension were common and mostly accompanied by impaired organ functions on admission. Higher D-dimer, higher NT-proBNP, and lower lymphocyte count were the independent risk factors of death in COVID-19 patients.

[Anatomical observation and clinical significance of rectosacral fascia in total mesorectal resection]

Objective: To observe the anatomical architecture of rectosacral fascia and discuss the best plan for accurate peri-rectal dissection in laparoscopic/robotic total mesorectal resection (TME). Methods: A descriptive cohort study was carried out. A total of 127 patients with rectal cancer who underwent TME in the Department of Colorectal Surgery at the affiliated Union hospital of Fujian Medical University were included, patients' demographics with their pathological details and operation videos were collected for analysis. Another 20 high-definition images of post-TME surgical specimens were collected from our digital database. A total of 28 cadaveric models were examined at the Laboratory of Clinical Applied Anatomy, Fujian Medical University, to observe the anatomical details of rectosacral fascia. Results: (1) Anatomical observation showed that the pre-hypogastric fascia attaches to the proper fascia of the mesorectum in a horizontal arc posteriorly, forming the rectosacral fascia. If this fusion couldn't be identified and appropriately transected during posterior space dissection, it would be easy to destroy the proper fascia and dissect through the mesorectum resulting in residual mesorectum tissue. After the fascia transaction, the proper fascia of the mesorectum is still intact distally. The upper part of rectosacral fascia bilaterally re-separated again into the proper fascia and pre-hypogastric fascia. The pre-hypogastric fascia acts as a "fascia barrier" when dissecting the lateral space constantly from posterior to anterior. The right attachment of the rectosacral fascia was gradually transected. The pelvic plexus from the right S2-S4 was covered by the pre-hypogastric fascia which is considered the outer side layer of rectosacral fascia laterally. It was observed that the fascia continued with the anterior layer of the Denonvilliers' fascia, which has been transected during anterior space dissection. The proper fascia, which is the inner side layer of rectosacral fascia laterally, was still intact. The edge of the right rectosacral fascia attachment ran obliquely from the back and upward into the front direction. The left extension was similar to the right. (2) Cadaveric specimens: at the level of the lower edge of S4 vertebral body, the pre-hypogastric fascia fused with the proper fascia to form the rectosacral fascia. The right attachment margin of the rectosacral fascia was cut off step by step. The attachment margin of the rectosacral fascia went from the back and upward to the front downward direction. The right edge of rectosacral fascia attachment continued with the anterior layer of the Denonvilliers' fascia at the pre-rectal space and attached to the pre-hypogastric fascia laterally. The pelvic plexus sends out many tiny rectal branches on the anterolateral side, which pass through the transitional area between pre-hypogastric fascia and the anterior layer of the Denonvilliers' fascia to innervate the rectum. (3) TME specimens observation: the posterior attachment of rectosacral fascia was curved around the mesorectum with bilateral oblique attachments. The mesorectum was covered by fusion fascia below the posterior and bilateral attachment margin while it was covered only by the proper fascia above it. Conclusion: according to the morphological characteristics of rectosacral fascia, the rectosacral fascia should be dissected at the level of S4 vertebral body posterior to the rectum in an arc, shape and then enter the superior-levator space. Before dissecting the bilateral spaces, the anterior space of the rectum should be dissected first. The anterior layer of the Denonvilliers' fascia should be cut off into an inverted "U" shape, and then the lateral space should be dissected from anterior to posterior. Finally, the lateral attachment of rectosacral fascia was transected to ensure the integrity of the mesorectum without damaging the pelvic plexus branches and NVB.

[Effects and mechanism of pyrroloquinoline quinine on mitochondrial function and cell survival of rat bone marrow mesenchymal stem cells under oxidative stress]

Objective: To observe the effects of pyrroloquinoline quinine (PQQ) on the mitochondrial function and cell survival of rat bone marrow mesenchymal stem cells (BMSCs) under oxidative stress, and to explore its mechanism. Methods: BMSCs of rats were cultured in vitro with Dulbecco's minimum essential medium/F12 medium containing fetal bovine serum in the volume fraction of 10% (hereinafter referred to as normal medium). The rat BMSCs of third to fifth passages in logarithmic growth phase were selected for the following experiments. (1) The cells were divided into normal control group, normal control+ PQQ group, hydrogen peroxide (H(2)O(2)) alone group, and H(2)O(2)+ PQQ group. The cells in normal control group were cultured in normal medium for 24 hours; the cells in normal control+ PQQ group were cultured in normal medium containing 100 μmol/L PQQ for 24 hours; the cells in H(2)O(2) alone group were cultured in normal medium containing 200 μmol/L H(2)O(2) for 24 hours; the cells in H(2)O(2)+ PQQ group were pre-incubated with normal medium containing 100 μmol/L PQQ for 2 hours, and then with H(2)O(2) added to the concentration of 200 μmol/L and cultured for 24 hours. The cell morphology of each group was observed under the inverted phase contrast microscope, and the cell survival rate was detected by cell count kit 8 method. (2) Five batches of cells were collected, and the cells of each batch were divided into normal control group, H(2)O(2) alone group, and H(2)O(2)+ PQQ group. The cells in each group received the same treatment as that in the corresponding group of experiment (1). After 24 hours of culture, one batch of cells was collected for apoptosis detection by flow cytometry, and the apoptosis rate was calculated. One batch of cells was subjected to mitochondrial membrane potential assay and JC-1 fluorescent staining observation using the JC-1 mitochondrial membrane potential detection kit and the inverted phase contrast fluorescence microscope, respectively. One batch of cells was collected for mitochondrial morphology observation under the transmission electron microscope. One batch of cells was subjected to catalase (CAT) and superoxide dismutase (SOD) activity assay by CAT activity assay kit and SOD activity assay kit, respectively. One batch of cells was subjected to Western blotting for determination of protein level of Epac1, adenine monophosphate activated protein kinase (AMPK), phosphorylated AMPK, cysteinyl aspartate-specific proteinase 3 (caspase-3), and cleaved caspase-3, and the phosphorylation level of AMPK and cleaved caspase-3/caspase-3 ratio were calculated. Six replicates were measured in each group for each index except for morphological observation. Data were statistically analyzed with one-way analysis of variance and independent sample equal variance t test. Results: (1) After 24 hours of culture, compared with those in normal control group (the cell survival rate was set to 100.0%), there was an increase in cell vacuole and a decrease in cell number in H(2)O(2) alone group, and the cell survival rate was significantly reduced to (74.3±2.9)% (t=6.39, P<0.01). Compared with those in H(2)O(2) alone group, the cell morphology of H(2)O(2)+ PQQ group was significantly improved, and the cell survival rate was significantly increased to (116.9±4.2)% (t=6.92, P<0.01); the cell survival rate in normal control+ PQQ group was (101.2±1.1)%, close to that of control group (t=1.06, P>0.05). (2) After 24 hours of culture, compared with (13.6±1.0)% in normal control group, the apoptosis rate of cells in H(2)O(2) alone group was significantly increased to (37.1±2.0)% (t=10.57, P<0.01). Compared with that in H(2)O(2) alone group, the apoptosis rate of cells in H(2)O(2)+ PQQ group was significantly declined to (17.0±0.7)% (t=9.49, P<0.01). (3) After 24 hours of culture, compared with those in normal control group, the mitochondrial membrane potential of cells in H(2)O(2) alone group was depolarized, the JC-1 fluorescent dye mainly existed in the cytoplasm in the form of monomer, which emitted green fluorescence, and a significant decrease in mitochondrial membrane potential was shown (t=4.18, P<0.01). Compared with those in H(2)O(2) alone group, the mitochondrial membrane potential of cells in H(2)O(2)+ PQQ group was increased to normal level (t=4.43, P<0.01), and the JC-1 fluorescent dye accumulated in mitochondria following the polarized mitochondrial membrane potential and emitted red fluorescence. (4) After 24 hours of culture, compared with that in normal control group, the mitochondrial structure of cells in H(2)O(2) alone group was disordered, with disappeared mitochondrial cristae and decreased mitochondrial matrix density. Compared with that in H(2)O(2) alone group, the mitochondrial structure of cells in H(2)O(2)+ PQQ group was regular and intact, with clearly visible mitochondrial cristae and increased mitochondrial matrix density. (5) After 24 hours of culture, compared with those in normal control group, the CAT activity of cells in H(2)O(2) alone group was significantly increased (t=4.54, P<0.05), and the SOD activity was significantly decreased (t=3.93, P<0.05). Compared with those in H(2)O(2) alone group, the CAT activity of cells in H(2)O(2)+ PQQ group was obviously increased (t=8.65, P<0.01), while there was no significant change in the SOD activity (t=0.72, P>0.05). (6) After 24 hours of culture, compared with those in normal control group, the protein expression of Epac1 of cells in H(2)O(2) alone group was significantly decreased (t=4.67, P<0.01), while the AMPK phosphorylation level and the cleaved caspase-3/caspase-3 ratio were significantly increased (t=7.88, 3.62, P<0.01). Compared with those in H(2)O(2) alone group, the protein expression of Epac1 and the AMPK phosphorylation level of cells in H(2)O(2)+ PQQ group were both significantly increased (t=4.34, 16.37, P<0.01), while the cleaved caspase-3/caspase-3 ratio was significantly declined (t=3.17, P<0.05). Conclusions: Pretreatment with PQQ can improve the mitochondrial function, reduce cell apoptosis rate, and enhance cell survival rate of rat BMSCs under oxidative stress, which may be related to the up-regulation of Epac1 protein expression, activation of AMPK signaling pathway, and down-regulation of cleaved caspase-3 protein level.

Long non-coding RNA GAS5 promotes natural killer cell cytotoxicity against gastric cancer by regulating miR-18a

Natural killer (NK) cells play significant roles in spontaneous antitumor response in multiple cancers, including gastric cancer. Currently, lncRNAs were identified as essential modulators in the development of NK cells via competing for the target miRNA. However, the regulatory mechanism of GAS5 in NK cells remains largely elusive. The expressions of GAS5 and miR-18a in NK cells were measured by qRT-PCR. The killing effects of NK cells were conducted by lactate dehydrogenase (LDH) assay. Detection of IFN-γ and TNF-α level was carried out using ELISA assay. The interaction between GAS5 and miR-18a was determined by the luciferase reporter system and RIP assay, respectively. We found that GAS5 expression was downregulated while miR-18a expression was upregulated in primary NK cells isolated from GC patient compared with the healthy controls. Moreover, activation of NK cells stimulated by IL-2 enhanced the secretion of IFN-γ, TNF-α, and the expression of GAS5. The deficiency of GAS5 significantly suppressed the secretion of IFN-γ and TNF-α as well as the killing effect of NK cells. Subsequently, luciferase reporter and RIP assay confirmed the interaction between GAS5 and miR-18a. In addition, miR-18a inhibitor attenuated GAS5 silencing induced inhibition of the cytotoxicity of activated NK cells. In conclusion, GAS5 promotes the killing effect of the natural killer cells against GC by regulating miR-18a, providing promising strategies for NK cells based antitumor therapies.

[Heritability of alcohol intake among adult twins, calculate by the structural equation model]

Objective: To explore the genetic and environmental effects on alcohol intake. Methods: Data on 9 231 pairs of adult twins of the same sex was collected from the Chinese National Twin Registry (CNTR), between 2015 and 2018 and used in this study. Structural equation model was used to estimate the effects of genetic and environmental factors on alcohol intake. Results: A total of 9 231 pairs of twins were included in the analysis, of which 6 085 pairs were monozygotic (MZ). The average age of MZ was (36.91±13.07) years old, and males accounted for 56.80%. The average age of dizygotic twins (DZ) was (35.22±12.48) years old, and males accounted for 55.91%. There were 350 pairs of alcohol-drinking twins were with high-risk, accounting for 1.90% and another 367 pairs (1.99%) were with medium-risk. Alcohol-drinkers with medium-risk were affected by additive genetics, common and unique environmental factors, seen among the twins. The overall heritability appeared as 24.3% (95%CI: 0 to 56.8%). Furthermore, 50.7% of the variation (95%CI: 20.4%-79.0%) could be explained by the common environmental factors and 24.9% (95%CI: 18.3%-36.5%) by unique environmental factors. High-risk related drinking behavior was affected by both common and unique environmental factors. The common environmental component appeared as 75.6% (95%CI: 69.6%-80.8%) and unique environmental component as 24.4% (95%CI: 19.2%-30.4%), respectively. Gender difference was seen in the heritability of those with medium or high-risk drinking behaviors. The heritability of men was 30.8% (95%CI: 9.8%-53.5%), while in women it was mainly affected by the environment. Conclusion: Both alcohol drinkers with medium and high-risk drinking behaviors were mainly affected by the environment factors and gender. With the increase of drinking volume, the effect of environment on drinking behaviors became more obvious.

[Heritability of coronary heart disease, based on the data from the Chinese adult twins]

Objective: To analyze the heritability of coronary heart disease (CHD) among the Chinese twin adults. Methods: A total of 20 477 same-sex twin pairs aged 25 years and older from the Chinese National Twin Registry were interviewed. Structure equation model was used to estimate the heritability of CHD. Results: After adjusting for age and gender, the overall heritability of CHD was 0.75(0.68-0.81). Stratified analyses showed that genetic factors play a more important role in CHD incidence in ≥40 years or female twins. While the development of CHD was mainly influenced by environmental factors in 25-39 years or male twins. Conclusion: CHD is influenced by both genetic and environmental factors and the heritability is high.

[Robotic surgical approach for rectal cancer]

Total mesorectal excision (TME) is the standard operation for mid-low rectal cancer. The advancement of minimally invasive surgery for rectal cancer has never been interrupted, from the conventional open surgery and laparoscopic surgery to robotic surgery and similarly from the conventional transabdominal approach to the transanal approach. All these approaches have focused on ensuring oncological control and meanwhile minimizing surgical trauma, preserving pelvic autonomic nerves, accelerating postoperative recovery and rehabilitation accordingly. In this review, we summarized the current progress of robotic TME for the treatment of rectal cancer and evaluated its safety and efficiency from the perspective of oncological and functional outcomes. The advantages behind robotic TME rely mainly on dealing with difficult rectal cancer cases. Besides, the robotic surgery system shortens the learning curve. However, the superiority of robotic surgery in preserving autonomic nerve has not been yet confirmed compared with laparoscopic surgery. We proposed the partial preservation of Denonvilliers' fascia during robotic TME, in order to enlarge the pelvic space, ensure the integrity of anterior mesorectum, and preserve the autonomic nerves. To date, there is still a lack of evidence regarding robotic taTME in the treatment of rectal cancer. However, several technical defects regarding taTME itself, including the residual of the terminal mesorectum, the sacrifice of distal rectal stump, and cancer cell dissemination due to airflow during dissection, need to be solved. The reported higher rate of local recurrence with multifocal pelvic side involvement and the anorectal dysfunction after taTME restrict its widespread performance.