[Association of glutamate receptor metabotropic 5 polymorphisms with schizophrenia susceptibility in a Chinese Han population]

Objectives: To investigate the association of single nucleotide polymorphisms (SNP) of glutamate receptor metabotropic 5 (GRM5) gene with schizophrenia susceptibility(SZ) in a Chinese Han population. Methods: Twenty-two SNPs located in GRM5 gene in 528 paranoid SZ patients and 528 control subjects recruited from northern Henanwere analyzed. The clinical features of 267 first-episode SZ patients were assessed with the Positive and Negative Syndrome Scale (PANSS). Results: The SZ group included 264 males and 264 females, aged (27±8) years; the healthy control group had 264 males and 264 females, aged (28±8) years.The differences in the genotypic and allelic frequencies of two SNPs (rs567990 and rs12421343) were statistically significant between the SZ patients and control groups (all P<0.05). The allele frequency of rs504183 was also statistically different between the two groups (P=0.030). When the subjects were stratified by sex, the genotypic and allelic frequencies of rs12421343 in female subjects were statistically different between the SZ patients and control groups. The allele frequencies of SNPs (rs12422021, rs567990, and rs7101540) were also statisticallydifferent between the two groups (all P<0.05). Meanwhile, rs567990 AG+GG carriers had a higher risk for SZ than AA carriers in female subjects(OR=1.946, 95%CI: 1.264-2.995). In addition, the patients with different genotypes (GG, AA+AG) of rs12422021 showed statistically significant differences in PANSS total score(84.8±24.4 vs 75.3±18.6), positive (16.2±4.3 vs 14.4±4.2), excitement (12.4±5.1 vs 10.2±4.1) and cognitive impairment factor scores (15.2±6.8 vs 13.3±3.9) (all P<0.05). The patients with AC and the other two genotypes (AA and CC) of rs504183 showed statistically significant differences in PANSS negative factor score(27.4±9.9 vs 24.7±8.4 and 23.4±8.1, both P<0.05). Conclusion: The current study provides further evidence that GRM5 is associated with SZ, and suggests a putative sex difference.

[Heritability and genetic correlation of body mass index and coronary heart disease in Chinese adult twins]

Objective: To examine the heritability of body mass index (BMI) and coronary heart disease (CHD), and to explore whether genetic factors can explain their correlation. Methods: Participants were from 11 provinces/municipalities reqistered in the Chinese National Twin Registry (CNTR) from 2010 to 2018. Participants data were collected from face-to-face questionnaire survey. Bivariate structure equation model was used to estimate the heritability and the genetic correlation of BMI and CHD. Results: A total of 20 340 pairs of same-sex twins aged ≥25 years were included in this study. After adjusting for age and gender, the heritability of BMI and CHD was 0.52 (95%CI: 0.49-0.55) and 0.76 (95%CI: 0.69-0.81), respectively. Further, a genetic correlation was identified between BMI and CHD (r_A=0.10, 95%CI:0.02-0.17). Conclusion: In Chinese adult twin population, BMI and CHD are affected by genetic factors, and their correlation can be attributed to the common genetic basis.

[Anatomical observation and clinical significance of the prostatic part of neurovascular bundle in total mesorectal excision]

Objective: To observe the anatomical architecture of the prostatic part of the neurovascular bundle (NVB) in total mesorectal excision (TME). Methods: A descriptive cohort study and an anatomical observation study were carried out. A total of 38 male patients with rectal cancer who underwent TME in the Department of Colorectal Surgery at the affiliated Union hospital of Fujian Medical University between November 2013 and March 2015 were included. A total of 4 hemipelvis were examined at the Laboratory of Clinical Applied Anatomy, Fujian Medical University. The following outcomes were observed: 1) the clinical significance of bleeding of the prostatic part of NVB: surgical videos were reviewed and the incidence of bleeding was recorded. The urogenital function was assessed using the International Prostate Symptom Score (IPSS) and International Index of Erectile Function (IIEF) score. The correlation between prostatic part bleeding and postoperative urogenital function was evaluated. 2) anatomical observation: the vessels, nerve fibers, as well as their surrounding fatty tissue from the prostatic part were treated as a whole, namely, the fat pad of the prostatic part. The anatomical architecture of the prostatic part in the surgical videos was reviewed and interpreted with the cadaveric findings. Categorical variables were compared between groups using a Fisher exact probability. while continuous variables with skewed distribution were compared between groups using the Mann-Whiteny U test. Results: The median age of the included 38 patients was 57 years (range, 31-75), and the median tumor distance to the anal verge was 6 cm (range, 1-8). Of them, a total number of 21 (55.3%) patients had bleeding of the prostatic part of NVB (bleeding group), while the rest had not (17 cases, 44.7%, non-bleeding group). 1) the clinical significance of bleeding of the prostatic part of NVB. The urinary function significantly decreased in patients in the bleeding group according to IPSS score after the 3rd month and the 6rd month of the surgery [7 (0-16) vs. 2 (0-3), Z=-1.787, P=0.088; 2 (0-15) vs. 0 (0-2), Z=-2.270, P=0.028]. There was no difference regarding the IPSS score between the two groups after 1 year of the surgery (P>0.05). With a total of 23 patients with normal preoperative sexual activity included, 87.5% (7/8) of patients in the non-bleeding group can expect to return to their preoperative baseline, this incidence was significantly higher than that of only 40% (6/15) in the bleeding group (P=0.029). 2) anatomical observation: for cadaveric observation, the prostatic part of NVB was located in the narrow triangular space composed of anterolateral walls of the rectum, the posterolateral surface of the prostate and the medial surface of the levator ani musculature. The tiny vascular branches and nerve fibers from the prostatic part were hard to identify. The cavernosal nerves cannot reliably be distinguished from the neural supply to the prostate, rectum and levator ani. In the cross-section of levels of prostatic base and mid-prostate in cadaveric hemipelvis specimens, the boundary of the prostatic part fat pad was partly overlapped and merged with the boundary of the mesorectum. Intraoperative observation showed that the areas of overlap referred to the rectal branches from the prostatic part piercing the proper fascia to supply the mesorectum, which carried the largest tension and high risk of bleeding during circumferential dissection toward the perirectal plane. The ultrasonic scalpel was required to pre-coagulate the rectal branches at the point close to the proper fascia of the rectum to prevent bleeding. In the cross-section of the prostatic apex level, the prostatic part approached ventrally and its boundary was away from the boundary of the mesorectum. Conclusions: NVB prostatic part injury is one of the causes of urogenital dysfunction after TME. The nerve fibers from the prostatic part were tiny, and its functional zones cannot be distinguished during operation. Therein, the fat pad of the prostatic part should be protected as a whole. Understanding the morphology of the fat pad of the prostatic part provides invaluable surgical guidance to dissect this critical area. When dissecting around the anterolateral rectal wall, appropriate anti-traction tension should be maintained and the rectal branches from the prostatic part should be coagulated with an ultrasonic scalpel to prevent bleeding.

Comprehensive analysis of the PD-L1 and immune infiltrates of N6-methyladenosine related long non-coding RNAs in bladder cancer

Bladder cancer (BLCA) is one of the most frequent genitourinary cancers, with a high rate of morbidity and mortality. The connection of m6A-related lncRNAs with PD-L1 and tumor immune microenvironment (TIME) in BLCA prognosis was extensively investigated in this study, which could suggest novel therapeutic targets for further investigation. 30 m6A-associated lncRNAs with predictive values from the TCGA data set were identified with co-expression analysis. Cluster2 was correlated with a poor prognosis, upregulated PD-L1 expression, and higher immune ratings. Cluster2 had larger amounts of resting CD4 memory-activated T cells, M2 macrophages, neutrophils, and NK cells infiltration. "CHEMOKINE SIGNALING PATHWAY" was the most significantly enriched signaling pathway according to GSEA, which may play an important role in the different immune cell infiltrates between cluster1/2. The risk model for m6A-related lncRNAs could be employed in a prognostic model to predict BLCA prognosis, regardless of other clinical features. Collectively, m6A-related lncRNAs were linked to PD-L1 and TIME, which would dynamically affect the number of tumor-infiltrating immune cells. m6A-related lncRNAs may be key mediators of PD-L1 expression and immune cells infiltration and may strongly affect the TIME of BLCA.

[Gene-lifestyle interaction on coronary heart disease in adult twins of China]

Objective: To explore the gene-lifestyle interaction on coronary heart disease (CHD) in adult twins of China. Methods: Participants were selected from twin pairs registered in the Chinese National Twin Registry (CNTR). Univariate interaction model was used to estimate the interaction, via exploring the moderation effect of lifestyle on the genetic variance of CHD. Results: A total of 20 477 same-sex twin pairs aged ≥25 years were recruited, including 395 CHD cases, and 66 twin pairs both had CHD. After adjustment for age and sex, no moderation effects of lifestyles, including current smoking, current drinking, physical activity, intake of vegetable and fruit, on the genetic variance of CHD were found (P>0.05), suggesting no significant interactions. Conclusion: There was no evidence suggesting statistically significant gene-lifestyle interaction on CHD in adult twins of China.

[Combined application of field epidemiology and laboratory etiology analysis in the investigation of a foodborne disease outbreak in Xinjiang uygur Autonomous Region, 2016]

Objectives: To analyze the causes of a foodborne outbreak in rural areas of Xinjiang between April 2 and April 5 in 2016. Methods: Cases and the relevant background information were obtained by consulting outpatient records of local health centers and regional people's hospitals and interviewing doctors and residents. All samples were collected by the laboratory test through epidemiological and food hygiene investigations. The χ² test (Fisher's exact probability method) was used to compare differences in incidence rates. Molecular typing, virulence genes and single nucleotide polymorphisms (SNPS) were analyzed by using Pulsed Field Gel Electrophoresis (PFGE) and Whole Genome Sequencing (WGS). Results: A total of 142 cases were found in this study, with incidence rate at 5.7‰ (142/24 979). Among all cases, the main symptoms were nausea (94%), vomiting (92%) and abdominal pain (67%), and the incubation period was about 2 h (1-7.5 h). There were 16 Staphylococcus aureus isolates identified and all of them could produce A+C+E mixed enterotoxin. PFGE showed 100% homology. WGS further revealed that there were 9 and 1 strains contained by Sequence Type 1 (ST1) and ST5405, respectively. All ST1 strains were in the same clade on the genome tree. Among these, 7 strains shared close proximity (74 SNPs) and 2 strains shared close relationships as well (127 SNPs). The S. aureus isolates that caused the outbreak were introduced by a mutant isolate from the milk supply station. Conclusions: This foodborne outbreak was mainly caused by Staphylococcus aureus contamination.

Elastic criterion for shear-banding instability in amorphous solids

In amorphous solids, plastic flow is prone to localization into shear bands via an avalanche of shear-transformation (ST) rearrangements of constituent atoms or particles. However, such banding instability still remains a lack of direct experimental evidence. Using a real 3D colloidal glass under shear as proof of principle, we study STs' avalanches into shear banding that is controlled by strain rates. We demonstrate that, accompanying the emergent shear banding, the elastic response fields of the system, typical of a quadrupole for shear and a centrosymmetry for dilatation, lose the Eshelby-type spatial symmetry; instead, a strong correlation appears preferentially along the banding direction. By quantifying the fields' spatial decay, we identify an elastic criterion for the shear-banding instability, that is, the strongly correlated length of dilatation is smaller than the full length of shear correlation. Specifically, ST-induced free volume has to be confined within the elastic shear domain of ST so that those STs can self-organize to trigger shear banding. This physical picture is directly visualized by tracing the real-space evolution of local dilatation and ST particles. The present work unites the two classical mechanisms: free volume and STs, for the fundamental understanding of shear banding in amorphous solids.

[Effects of exosomes from human adipose-derived mesenchymal stem cells on inflammatory response of mouse RAW264.7 cells and wound healing of full-thickness skin defects in mice]

Objective: To investigate the effects of exosomes from human adipose-derived mesenchymal stem cells (ADSCs) on inflammatory response of mouse RAW264.7 cells and wound healing of full-thickness skin defects in mice. Methods: The experimental research methods were adopted. The discarded adipose tissue was collected from 3 female patients (aged 10-25 years) who underwent abdominal surgery in the First Affiliated Hospital of Air Force Medical University. ADSCs were extracted from the adipose tissue by collagenase Ⅰ digestion and identified with flow cytometry. Exosomes were extracted from the human ADSCs by differential ultracentrifugation, the morphology of the exosomes was observed by transmission electron microscopy, the particle diameter of the exosomes was detected by nanoparticle tracking analyzer, and the protein expressions of CD9, CD63, tumor susceptibility gene 101 (TSG101), and β-actin were detected by Western blotting. The human ADSCs exosomes (ADSCs-Exos) and RAW264.7 cells were co-cultured for 12 h, and the uptake of RAW264.7 cells for human ADSCs-Exos was observed. The RAW264.7 cells were divided into phosphate buffer solution (PBS) group stimulated with PBS for suitable time, endotoxin/lipopolysaccharide (LPS) stimulation 2 h group, LPS stimulation 4 h group, LPS stimulation 6 h group, LPS stimulation 12 h group, and LPS stimulation 24 h group stimulated with LPS for corresponding time, with 3 wells in each group, and the mRNA expressions of interleukin 1β (IL-1β), tumor necrosis factor α (TNF-α), IL-6, and IL-10 were detected by real-time fluorescence quantitative reverse transcription polymerase chain reaction (RT-PCR) method. The RAW264.7 cells were divided into PBS group, LPS alone group, and LPS+ADSCs-Exos group, with 3 wells in each group, which were dealt correspondingly for the time screened out in the previous experiment, the mRNA expressions of IL-1β, TNF-α, IL-6, IL-10, trasforming growth factor β (TGF-β,) and vascular endothelial growth factor (VEGF) were detected by real time fluorescence quantitative RT-PCR method, and the protein expressions of inducible nitric oxide synthase (iNOS) and arginase 1 (Arg1) were detected by Western blotting. Twenty-four 8-week-old male BALB/c mice were divided into PBS group and ADSCs-Exos group according to the random number table, with 12 mice in each group, and a full-thickness skin defect wound with area of 1 cm×1 cm was inflicted on the back of each mouse. Immediately after injury, the wounds of mice in the two groups were dealt correspondingly. On post injury day (PID) 1, the concentration of IL-1β and TNF-α in serum were detected by enzyme-linked immunosorbent assay, and the mRNA expressions of IL-1β, TNF-α, and IL-6 were detected by real time fluorescence quantitative RT-PCR method. On PID 3, 6, 9, 12, and 15, the wound healing was observed and the wound non-healing rate was calculated. On PID 15, the defect length of skin accessory and collagen volume fraction (CVF) were detected by hematoxylin eosin staining and Masson staining, respectively, the CD31 expression and neovascularization were detected by immunohistochemistry, and the ratio of Ki67 positive cells, the ratio of iNOS and Arg1 double positive cells, and the ratio of iNOS positive cells to Arg1 positive cells and their fluorescence intensities were detected by immunofluorescence method. The number of samples in animal experiments was 6. Data were statistically analyzed with analysis of variance for repeated measurement, one-way analysis of variance, and independent sample t test. Results: At 12 h of culture, the cells exhibited a typical spindle shape, which were verified as ADSCs with flow cytometry. The exosomes with a vesicular structure and particle diameters of 29-178 nm, were positively expressed CD9, CD63, and TSG101 and negatively expressed β-actin. After 12 h of co-culture, the human ADSCs-Exos were endocytosed into the cytoplasm by RAW264.7 cells. The mRNA expressions of IL-1β, TNF-α, IL-6, and IL-10 of RAW264.7 cells in LPS stimulation 2 h group, LPS stimulation 4 h group, LPS stimulation 6 h group, LPS stimulation 12 h group, and LPS stimulation 24 h group were significantly higher than those in PBS group (with t) values of 39.10, 14.55, 28.80, 4.74, 48.80, 22.97, 13.25, 36.34, 23.12, 18.71, 29.19, 41.08, 11.68, 18.06, 8.54, 43.45, 62.31, 22.52, 21.51, and 37.13, respectively, P<0.01). The stimulation 12 h with significant expressions of all the inflammatory factors was selected as the time point in the following experiment. After stimulation of 12 h, the mRNA expressions of IL-1β, TNF-α, IL-6, and IL-10 of RAW264.7 cells in LPS alone group were significantly higher than those in PBS group (with t values of 44.20, 51.26, 14.71, and 8.54, respectively, P<0.01); the mRNA expressions of IL-1β, TNF-α, and IL-6 of RAW264.7 cells in LPS+ADSCs-Exos group were significantly lower than those in LPS alone group (with t values of 22.89, 25.51, and 8.03, respectively, P<0.01), while the mRNA expressions of IL-10, TGF-β, and VEGF were significantly higher than those in LPS alone group (with t values of 9.89, 13.12, and 7.14, respectively, P<0.01). After stimulation of 12 h, the protein expression of iNOS of RAW264.7 cells in LPS alone group was significantly higher than that in PBS group and LPS+ADSCs-Exos group, respectively (with t values of 11.20 and 5.06, respectively, P<0.05 or P<0.01), and the protein expression of Arg1 was significantly lower than that in LPS+ADSCs-Exos group (t=15.01, P<0.01). On PID 1, the serum concentrations of IL-1β and TNF-α and the mRNA expressions of IL-1β, TNF-α, and IL-6 in wound tissue of mice in ADSCs-Exos group were significantly those in lower than PBS group (with t values of 15.44, 12.24, 9.24, 7.12, and 10.62, respectively, P<0.01). On PID 3, 6, 9, 12, and 15 d, the wound non-healing rates of mice in ADSCs-Exos group were (73.2±4.1)%, (53.8±3.8)%, (42.1±5.1)%, (24.1±2.8)%, and 0, which were significantly lower than (82.5±3.8)%, (71.2±4.6)%, (52.9±4.1)%, (41.5±3.6)%, and (14.8±2.5)% in PBS group, respectively (with t values of 4.77, 8.93, 5.54, 7.63, and 7.59, respectively, P<0.01). On PID 15, the defect length of skin accessory in wounds of mice in PBS group was significantly longer than that in ADSCs-Exos group (t=9.50, P<0.01), and the CVF was significantly lower than that in ADSCs-Exos group (t=9.15, P<0.01). On PID 15, the CD31 expression and the number of new blood vessels (t=12.99, P<0.01), in wound tissue of mice in ADSCs-Exos group were significantly more than those in PBS group, and the ratio of Ki67 positive cells was significantly higher than that in PBS group (t=7.52, P<0.01). On PID 15, the ratio of iNOS and Arg1 double positive cells in wound tissue of mice in PBS group was (12.33±1.97)%, which was significantly higher than (1.78±0.29)% in ADSCs-Exos group (t=13.04, P<0.01), the ratio of iNOS positive cells and the fluorescence intensity of iNOS were obviously higher than those of ADSCs-Exos group, and the ratio of Arg1 positive cells and the fluorescence intensity of Arg1 were obviously lower than those of ADSCs-Exos group. Conclusions: The human ADSCs-Exos can alleviate inflammatory response of mouse RAW264.7 cells, decrease macrophage infiltration and secretion of the pro-inflammatory cytokines, increase the secretion of anti-inflammatory cytokines to promote neovascularization and cell proliferation in full-thickness skin defect wounds of mice, hence accelerating wound healing.

[The clinical efficacy of the stratification medical treatment based on the risk estimation of motor complications in Parkinson's disease]

Objectives: To evaluate the clinical efficacy of the stratification medical treatment based on the motor complications risk estimation in improving the quality of life, motor symptoms and delaying the motor complications in Parkinson's patients. Methods: Outpatients and inpatients from Xinhua Hospital, Shanghai Jiao Tong University, were recruited between November 2019 and June 2020. The participants were all clinically diagnosed with PD and treated with anti-PD medications, but had no history of motor complications, with the 8-item Parkinson's disease questionnaire summary index (PDQ-8 SI)>18.59. At baseline, the demographic characteristics, PD medical history, levodopa dosage (LD) and levodopa equivalent dosage (LED) were collected, and the evaluation of PDQ-8, Unified Parkinson's disease rating scale (UPDRS)-Ⅱ and Ⅲ, Hoehn and Yahr (H&Y) grade, Hamilton anxiety scale-14 (HAMA-14), Hamilton depression scale-24 (HAMD-24), mini-mental state examination (MMSE), Pittsburgh sleep quality index (PSQI), and Epworth sleepiness scale (ESS) tools was accomplished in all participants. Meanwhile, a Parkinson's disease risk estimation scale for motor complications was used to assess patients' risk of motor complications, and thus the medication was stratified in PD patients accordingly. During the 6-month and 12-month follow-ups, the evaluation of the above-mentioned parameters was repeated in all participants. At the 3-month and 9-month follow-ups, the information of anti-PD medications, the occurrence of motor complications (motor fluctuations and dyskinesia) and adverse drug reactions were recorded, and PDQ-8 was also evaluated. Results: Two hundred and fifty-one patients completed the 1-year follow-up, with 135 males and 116 females. At baseline, the median age of the patients was 66 (60, 71) years and the median PDQ-8 SI was 31.2 (21.9, 40.6). Additionally, 15.9% (40/251) of the patients were at high risk of motor fluctuation, and 7.2% (18/251) were at high risk of dyskinesia. There were significant differences in the age of onset, disease duration, PD treatment duration, the scores of UPDRS-Ⅱ and Ⅲ, H&Y Grade, and PDQ-8 SI among PD patients of different risk groups (all P<0.05). In the 12th month, the median of PDQ-8 SI, Δ PDQ-8 SI and Δ UPDRS-Ⅲ was 12.5 (9.4, 18.8), -15.6 (-21.9, -9.4) and -9(-16, -4), respectively, which was statistically different from that of baseline (all P<0.05). The change of UPDRS-Ⅱ scores in the group with high risk of motor fluctuation was statistically different from that in the groups with low and moderate risk (P<0.05). The changes of PSQI score, LD and LED in the group with high risk of dyskinesia was statistically different from those in the groups with low and moderate risk (all P<0.05). During the follow-up, the incidence of motor fluctuation and dyskinesia was 9.56% (24/251) and 5.97% (15/251), respectively. Conclusion: The stratification medical treatment might have a positive intervention effect on promoting a better quality of life, improving motor symptoms and delaying motor complications in PD patients.

Exploring Lorentz Invariance Violation from Ultrahigh-Energy γ Rays Observed by LHAASO

Recently, the LHAASO Collaboration published the detection of 12 ultrahigh-energy γ-ray sources above 100 TeV, with the highest energy photon reaching 1.4 PeV. The first detection of PeV γ rays from astrophysical sources may provide a very sensitive probe of the effect of the Lorentz invariance violation (LIV), which results in decay of high-energy γ rays in the superluminal scenario and hence a sharp cutoff of the energy spectrum. Two highest energy sources are studied in this work. No signature of the existence of the LIV is found in their energy spectra, and the lower limits on the LIV energy scale are derived. Our results show that the first-order LIV energy scale should be higher than about 10^{5} times the Planck scale M_{Pl} and that the second-order LIV scale is >10^{-3}M_{Pl}. Both limits improve by at least one order of magnitude the previous results.

[The accuracy and influencing factors of sleep staging based on single-channel EEG via a deep neural network]

Objective: To investigate theaccuracy of artificial intelligence sleep staging model in patients with habitual snoring and obstructive sleep apnea hypopnea syndrome (OSAHS) based on single-channel EEG collected from different locations of the head. Methods: The clinical data of 114 adults with habitual snoring and OSAHS who visited to the Sleep Medicine Center of Beijing Tongren Hospital from September 2020 to March of 2021 were analyzed retrospectively, including 93 males and 21 females, aging from 20 to 64 years old. Eighty-five adults with OSAHS and 29 subjects with habitual snoring were included. Sleep staging analysis was performed on the single lead EEG signals of different locations (FP2-M1, C4-M1, F3-M2, ROG-M1, O1-M2) using the deep learning segmentation model trained by previous data. Manual scoring results were used as the gold standard to analyze the consistency rate of results and the influence of different categories of disease. Results: EEG data in 124 747 30-second epochs were taken as the testing dataset. The model accuracy of distinguishing wake/sleep was 92.3%,92.6%,93.5%,89.2% and 83.0% respectively,based on EEG channel Fp2-M1, C4-M1, F3-M2, REOG-M1 or O1-M2. The mode accuracy of distinguishing wake/REM/NREM and wake/REM/N1-2/SWS , was 84.7% and 80.1% respectively based on channel Fp2-M1, which located in forehead skin. The AHI calculated based on total sleep time derived from the model and gold standard were 13.6[4.30,42.5] and 14.2[4.8,42.7], respectively (Z=-2.477, P=0.013), and the kappa coefficient was 0.977. Conclusions: The autonomic sleep staging via a deep neural network model based on forehead single-channel EEG (Fp2-M1) has a good consistency in the identification sleep stage in a population with habitual snoring and OSAHS with different categories. The AHI calculated based on this model has high consistency with manual scoring.

Lipopolysaccharide inhibits hypothalamic Agouti-related protein gene expression via activating mechanistic target of rapamycin signaling in chicks

Lipopolysaccharide (LPS) induces profound anorexia in birds. However, the neuronal regulatory network underlying LPS-provoked anorexia is unclear. To determine whether any cross talk occurs among hypothalamic mechanistic target of rapamycin (mTOR) and LPS in the regulation of appetite, we performed an intracerebroventricular injection of rapamycin (an mTOR inhibitor) on LPS-treated chicks. The results indicate that peripheral administrations of LPS decreased the agouti-related protein (AgRP) mRNA level, but increased the phosphorylated mTOR and nuclear factor-кB (NF-кB) protein level. Blocking mTOR significantly attenuated LPS-induced anorexia, AgRP suppression, and p-NF-кB increase. Thus, the results suggest that LPS causes anorexia via the mTOR-AgRP signaling pathway, and mTOR signaling is also associated with the regulation of LPS in p-NF-кB.

Conformer-specific photochemistry imaged in real space and time

[Figure: see text].

Imaging the short-lived hydroxyl-hydronium pair in ionized liquid water

[Figure: see text].

[Analysis of the effect of modified cervical cerclage in the treatment of cervical insufficiency]

Objective: To discuss the surgical effect of modified cervical cerclage for the treatment of pregnant women with cervical insufficiency. Methods: The clinical data of 225 pregnant women who underwent modified cervical cerclage in Qilu Hospital (Qingdao) were selected for retrospective analysis from April 2014 to June 2020. Surgical success rate, full-term birth rate, preterm birth rate, prolonged pregnancy weeks and newborn birth weight were compared between singleton and twin pregnancies, preventive cerclage and emergency cerclage, surgery before and after 18 weeks, naturally and in vitro fertilization and embryo transfer (IVF-ET) conceived pregnant women respectively. Results: Among the 225 pregnant women, the gestational weeks of surgery were 14-24⁺⁵ weeks, mean gestational weeks of delivery were 38⁺² weeks (35⁺⁵-39⁺³ weeks), the number of prolonged gestation were (20.3±5.2) weeks, and the newborn birth weight was (3 065±735) g; the overall surgical success rate was 92.9% (209/225), and the miscarriage rate was 7.1% (16/225); among the surviving newborns, the full-term birth rate was 73.7% (154/209), and the preterm birth rate was 26.3% (55/209). All cases had no intraoperative complications. Among the 225 pregnant women, 202 (89.8%, 202/225) cases were singleton pregnancies, and 23 (10.2%, 23/225) cases were twin pregnancies; 201 (89.3%, 201/225) cases underwent preventive cervical cerclage, and 24 (10.7%, 24/225) cases underwent emergency cervical cerclage; 190 (84.4%, 190/225) cases underwent the surgery before 18 weeks, and 35 (15.6%, 35/225) cases underwent the surgery after 18 weeks; 49 (21.8%, 49/225) cases were conceived by IVF-ET. There was no statistically significant difference in the overall surgical success rate of single and twin group (P>0.05). The full-term birth rate, newborn birth weight and prolonged pregnancy weeks of single group were higher than those of twin group (P<0.05). There were no statistical differences between preventive and emergency cerclage in overall surgical success rate, full-term birth rate, preterm birth rate, and newborn birth weight (all P>0.05). The pregnancy prolonged weeks of preventive cerclage was higher than that of emergency cerclage (P<0.05). There were no statistically significant differences in the overall surgical success rate, full-term birth rate, preterm birth rate and birth weight of newborns at different surgical timings (all P>0.05). The pregnancy prolonged week for those who underwent surgery before 18 weeks was higher than that of surgery after 18 weeks (P<0.05). The premature birth rate of IVF-ET was higher than that of naturally conceived pregnant women (P<0.05). Conclusion: The modified cervical cerclage could effectively prolong the gestational weeks of delivery, reduce the rate of preterm birth, and the operation is simple and easy to promote. It could be used as a surgical option for patients with cervical insufficiency.

[Gene-body mass index interaction on coronary heart disease in Chinese adult twins]

Objective: To explore the gene-body mass index (BMI) interaction on coronary heart disease (CHD) in the Chinese adult twins. Methods: A total of 20 340 same-sex twin pairs registered in the Chinese National Twin Registry (CNTR) were enrolled in this study. Classical twin structure equation model was used to estimate the gene-BMI interaction on CHD. Results: After adjusting for age, we found that genetic variance of CHD differed as the function of BMI in male twins, which indicated the presence of a gene-BMI interaction on CHD (P=0.008).The genetic moderating effect (β_a) was -0.14 (95%CI: -0.22--0.04), indicating that for each logarithmic transformation value of BMI increase, genetic path parameters would decrease by 0.14, which would result in the decrease of genetic variance of CHD. And the heritability of CHD was 0.77 (95%CI: 0.65-0.86) among the male twins with lower BMI (<24.0 kg/m²), but 0.56 (95%CI: 0.33-0.74) among the male twins with high BMI (≥24.0 kg/m²). However, there was no evidence suggesting that BMI could moderate genetic variants of CHD in female. Conclusion: We found a significant gene-BMI interaction on CHD in the Chinese male adult twins in China, and the heritability of CHD was higher among the twins whose BMI was <24.0 kg/m².

[Anatomical observation of the right retroperitoneal fascia and its clinical significance in complete mesocolic excision for right colon cancer]

Objective: To investigate the anatomic characteristics of the right retroperitoneal fascia and its surgical implementation while performing complete mesocolic excision (CME) for right colon cancer. Methods: A descriptive study was carried out. (1) Clinicopathological data and surgical videos of 17 non-consecutive patients undergoing laparoscopic right hemicolectomy (extended right hemicolectomy) with CME for right colon cancer at Department of Colorectal Surgery of Union Hospital, Fujian Medical University between January 2020 and October 2020 were retrospectively collected. The construction of right retroperitoneal fascia was observed from caudal dorsal direction and caudal ventral direction. (2) Three postoperative specimens from 3 cases undergoing laparoscopic right hemicolectomy with CME for right colon cancer in June 2020 were prospectively included to observe anatomy and examine histology. (3) Five abdominal cadaver specimens from the Department of Anatomy of Fujian Medical University were enrolled, including 3 males and 2 females. Anatomical observation and histological studies were performed from the cranial approach and the caudal dorsal approach. Masson staining was used to examine the histology. Results: (1) Surgical video observation: The typical structure of right retroperitoneal fascia could be observed in all the 17 patients. The fascia was a rigid barrier between the posterior space of the ascending colon and the anterior pancreaticoduodenal space behind the transverse colon. The right retroperitoneal fascia should be sharply cut to communicate between the two spaces to avoid entering the right mesocolon by mistake. The severed ventral stump of the right retroperitoneal fascia ran along the dorsal side of the right hemicolon to the lateral side, and the dorsal stump covered the level of the duodenum caudally, and continued to move downward, covering the surface of Gerota's fascia. (2) Observation of 3 surgical specimens: The dorsal side of the right mesocolon was smooth and intact, which could be anchored in the corresponding area of the lateral edge of the duodenum. The ventral stump of the right retroperitoneal fascia could be seen, which attached to the dorsal side of the right mesocolon semi-circularly. Masson staining observation: The ventral stump of the right retroperitoneal fascia ran cephalad, fused with the dorsal side of the right mesocolon tightly and curled. The caudal side of confluence and the dorsal side of the right mesocolon presented a bilobed structure. (3) Anatomy of 5 cadaveric specimens: The right retroperitoneal fascia was a thin fascia structure, which was a rigid barrier between the anterior pancreaticoduodenal space behind the transverse colon and the posterior space of the ascending colon. The ventral stump of the right retroperitoneal fascia (including the dorsal side of the right mesocolon), the dorsal stump of the right retroperitoneal fascia (including part of the duodenal wall) and the dorsal side of the right mesocolon were retrieved for histological examination. The ventral stump of the right retroperitoneal fascia fused with the dorsal side of the right mesocolon by the cephalic side, and the dorsal side of the right hemi-mesocolon on the fusion level by caudal side gradually separated into a double-layer loose fascial structure. The dorsal stump of the right retroperitoneal fascia covered the surface of the duodenum level, moved on from the ventral side to the surface of the prerenal fascia, and continued to the caudal side. Conclusions: The right retroperitoneal fascia is a rigid barrier between the anterior pancreaticoduodenal space behind the transverse colon and the posterior space of the ascending colon. The Toldt fascia formed by fusion with the dorsal lobe of the right colon travels to the edge of the descending and horizontal part of the duodenum and separates again. The right retroperitoneal fascia is attached to the edge of the duodenum, reversing and running on the surface of the prerenal fascia, while the dorsal lobe of the right colon runs in front of the pancreas and duodenum, and shifts to the pancreaticoduodenal fascia. During the operation, this fascia should be identified and cut to penetrate the anterior pancreaticoduodenal space behind the transverse colon and the posterior ascending colon space, which helps to ensure the integrity of the dorsal side of the right hemi-mesocolon.

[Anatomical observation of the left parietal peritoneum and its clinical significance in left retro-mesocolic space dissection]

Objective: To investigate the anatomic characteristics of the left parietal peritoneum and its surgical implementation while dissecting in left retro-mesocolic space. Methods: A descriptive case series research methods was used. (1) surgical videos of 35 patients who underwent laparoscopic radical resection (complete mobilization of splenic flexure) of colorectal cancer in Union Hospital of Fujian Medical University between January 2018 and December 2018 were reviewed; (2) four specimens after radical resection of rectal cancer performing in June 2020 were prospectively enrolled and reviewed; (3) five specimens of left parietal peritoneum from 5 cadaveric abdomen (3 males and 2 females) were enrolled and reviewed as well; Tissues of 3 unseparated regions, namely the root of the inferior mesenteric artery (IMA), the medial region and the lateral region (including kidney tissue), from above the 5 cadaveric abdominal specimens were selected to perform Masson staining and histopathological examination. Results: (1) Surgical video observation: "Staggered layer phenomenon" and typical left parietal peritoneum was found in 77.1% (27/35) of patients when the left retro-mesocolic space was separated from the lateral and central approaches. The left parietal peritoneum presented as a rigid fascia barrier between the lateral and central approaches, which was a translucent dense connective tissue fascia. After the splenic flexure were completely mobilized, the left parietal peritoneum stump continued to the cephalic side. (2) Observation of 4 surgical specimens: The dorsal side of the left mesocolon specimen was studied, and the left parietal peritoneum stump edge was identified. The outside of the stump edge was the left hemicolon dorsal layer, which was continuously downward to the rectal fascia propria. (3) Cadaveric abdominal specimens: The left retro-mesocolic space was separated through lateral and central approaches, and the rigid fascia barrier, essentially the left parietal peritoneum and Gerota fascia, was encountered. Cross-section view showed that the left parietal peritoneum could be further detached from the dorsal layer of the left mesocolon from the outside, but could not be further detached from the inside out. (4) Histological examination: There was no obvious fascia structure in the IMA root region, while outside the IMA root region, the left bundle of inferior mesenteric plexus penetrating Gerota fascia was observed. There were 4 layers of fascias in the medial region, including the ventral layer of the left mesocolon, the dorsal layer of the left mesocolon, left parietal peritoneum and Gerota fascia. Small vessels were observed between the dorsal layer of the left mesocolon and the left parietal peritoneum. In lateral region, renal tissue and renal fascia were observed. Three layers of fascia structures were observed clearly under high power field, including the dorsal layer of the left mesocolon, left parietal peritoneum, and Gerota fascia. Conclusions: The left parietal peritoneum is the anatomical basis of the "staggered layer phenomenon" from the lateral or central approaches during the separation of left retro-mesocolic space. The small vessels in the dissection plane are the anatomical basis of intraoperative microbleeding, which need pre-coagulation. The central part of Gerota fascia is penetrated by the branches of the inferior mesenteric plexus, which results in a relatively dense surgical plane. Thus, during the dissection through the central approach, it is easy to involve in wrong surgical plane by deeper dissection.

[Modification of physical activity on genetic effects of type 2 diabetes mellitus: a twin pairs cohort study in China]

Objective: To explore the modification effect of physical activity on the genetic effects of type 2 diabetes mellitus (T2DM). Methods: The univariate moderation model was fitted to calculate the modifying effect of physical activity on the genetic effects of T2DM based on the data of 12 107 pairs of same gender twins aged 30 years and older enrolled by the Chinese National Twin Registry in 11 provinces/cities in China. Results: After adjusting for age and gender, the heritability of T2DM was 0.56 (0.31-0.84). Qualified physical activity could attenuate the genetic effects of T2DM. The heritability of T2DM in twin pairs with qualified physical activity was 0.46 (0.06-0.88), which was lower than that in twin pairs without qualified physical activity during the same model [0.68(0.36-0.94)]. Conclusion: T2DM is a moderate genetic disease, physical activity can modify the genetic effects of T2DM.

[A descriptive analysis on body mass index distribution in adult twin pairs in China]

Objective: To describe the differences in body mass index (BMI) distribution in adult twins registered in Chinese National Twin Registry (CNTR), and provide evidence for the risk factor analysis and prevention and control of overweight or obesity. Methods: A total of 32 725 twin pairs aged 18 years and above who completed the questionnaire survey during 2010-2018 and had complete registered information in CNTR and normal body weight and length were included in the analysis on the population and region specific distributions of BMI of twin pairs and the difference in BMI in twin pairs. Results: The twin pairs included in the analysis were aged (34.6±12.4) years, the twin pairs of same gender accounted for 79.7%. The average BMI was 22.5 kg/m². The overall prevalence of obesity and overweight was 4.9% and 23.7%, respectively. Participants who were men, 50-59 years old, married, had lower education level, and lived in northern China had higher overweight rate and obesity rate (P<0.001). The difference in overweight or obesity prevalence between monozygotic (MZ) twin pars and dizygotic (DZ) twin pairs was not significant, but firstborn twin pairs had slightly higher rates of overweight and obesity than later-born twin pairs (P<0.05). The analysis in same gender-twin pairs indicated that the difference in BMI was associated with age (trend test: P<0.001), and the difference was more obvious in DZ twin pair in MZ pair and this difference increased with age. The concordant rate of BMI was higher in MZ twin pairs than DZ twin pairs (P<0.05). Conclusion: The distribution of BMI of twin pairs varied with population and region and BMI varied with age due to its genetic nature.

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.

Thermo-Responsive Shape Memory Behavior of Methyl Vinyl Silicone Rubber/Olefin Block Copolymer Blends via Co-Crosslinking

Shape memory polymers (SMPs) are developed by blending and cross-linking polymers which include crystalline domains and cross-linked networks. In this paper, we describe the morphology, thermal and shape memory behavior of methyl vinyl silicone rubber (MVMQ)/olefin block copolymer (OBC) blends prepared by a melt-blending and chemical cross-linking method. MVMQ without crystalline domains could not hold its temporary shape. After introducing the OBC, the obtained blends exhibited excellent dual shape memory properties. The cross-linking networks of MVMQ acted as reversible domains, while crystalline regions of OBC worked as fixed domains. When the blending ratio of MVMQ/OBC was 50/ 50, the blend had both a high shape fixity ratio and shape recovery ratio.

[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.

Photodissociation of aqueous I 3 - observed with liquid-phase ultrafast mega-electron-volt electron diffraction

Developing femtosecond resolution methods for directly observing structural dynamics is critical to understanding complex photochemical reaction mechanisms in solution. We have used two recent developments, ultrafast mega-electron-volt electron sources and vacuum compatible sub-micron thick liquid sheet jets, to enable liquid-phase ultrafast electron diffraction (LUED). We have demonstrated the viability of LUED by investigating the photodissociation of tri-iodide initiated with a 400 nm laser pulse. This has enabled the average speed of the bond expansion to be measured during the first 750 fs of dissociation and the geminate recombination to be directly captured on the picosecond time scale.

[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.