[Epidemic Characteristics of the Novel Coronavirus Delta Variant in Guangzhou and Grid Crowd Management Based on Public Security Forensic Perspective].

ABSTRACT: Abstract： Objective To analyze the first epidemic spread of the novel coronavirus Delta variant in China based on public security forensic perspective, investigate its transmission characteristics, contributing factors, and epidemiologic research experience, and provide a reference for the prevention and control of the epidemic caused by the novel coronavirus variant. Methods Based on the information that public security forensic experts obtained from front-line epidemiologic research, the gender, age, place of residence, transmission route and infectivity of the coronavirus disease 2019 （COVID-19） confirmed cases, asymptomatic infected persons and their close contacts in Guangzhou caused by the novel coronavirus Delta variant were analyzed. The basic reproduction number （R0） during this epidemic in Guangzhou was calculated. Results Among the 153 cases infected with novel coronavirus Delta variant in the epidemic, 63 cases were male and 90 cases were female, their age ranging from 1 to 92 years, with a median age of 49 years. The main route of transmission was close contact, including dining together, co-living, and close contact in the same residential building. There were 31 cases of family clusters, 25 of which were in Liwan District. The epidemic lasted from May 26 to May 29, and the R0 remained above 4.0. After May 30, R0 began to decline and remained below 1.0 from June 7. Conclusion The novel coronavirus Delta variant is highly infectious, the crowd is generally susceptible to infection and family cluster cases are easy to occur. So, it is necessary to precisely prevent and control this strain. Public security forensic experts have both medical literacy and criminal investigation capabilities, they can play a more professional role in epidemic prevention and control.

[Integrated analysis of DNA methylation and gene expression profiles of hepatocellular carcinoma to construct miR-1180-3p relevant ceRNA regulatory network].

Objective: This study analyzes the expression level of miR-1180-3p and constructs the regulatory network of relevant ceRNA by integrating the DNA methylation and gene expression profile of hepatocellular carcinoma from the Cancer Genome Atlas (TCGA). Methods: Firstly, the expression level of miR-1180-3p in hepatocellular carcinoma and adjacent tissues was analyzed by TCGA database, and the differential expression of lncrna and mRNA was screened. Secondly, the LncBase database and the TargetScan database were used to predict the relationship between miR-1180-3p and lncRNA and mRNA, and the DNA methylation-mediated lncRNA was screened by the DNA methylation profile of lncRNA. Finally, Cytoscape software was used to construct miR-1180-3p relevant ceRNA network, and WebGestalt website was used to perform GO and KEGG analysis of related mRNA in ceRNA. Results: Compared with patients with low expression of miR-1180-3p (mean overall survival duration, 5.69 ± 0.35 years), patients with high expression of miR-1180-3p had shorter overall survival time (mean overall survival duration, 3.99 ± 0.47 years), indicating that the high expression of miR-1180-3p was hepatocellular carcinoma risk factor affecting the prognosis (HR = 1.28, 95% CI = 1.1 ~ 1.5, P < 0.01). A miR-1180-3p related ceRNA regulatory network was constructed in this study, which contained 2 lncRNAs (F11-AS1 and LINC01511) and 37 mRNAs. Conclusion: This study has successfully constructed miR-1180-3p relevant ceRNA regulatory network, and DNA methylation-mediated F11-AS1 and F11-AS1/miR-1180-3p/C11of54 ceRNA regulatory axis has played an important role in the occurrence and development of hepatocellular carcinoma.

[Classification of pregnancy complicating Guillain-Barré syndrome].

Objective: To explore the classification, clinical features, the short-term efficacy of intravenous immunoglobulin (IVIg) for Guillain-Barré syndrome(GBS) and look for predictors of acute motor axonal neuropathy (AMAN) during pregnancy. Methods: The clinical data of 45 hospitalized pregnant patients with GBS recruited from October 2008 to October 2017 at the Tianjin Medical University general hospital, Handan City First Hospital and Nankai University Affiliated Tianjin Fourth Central Hospital, were collected and analyzed retrospectively, and patients were divided into the acute inflammatory demyelinating polyneuropathies (AIDP) group and the AMAN group. The clinical features and efficacy of IVIg were compared between the two groups. Logistic regression analysis was used to analyze the predictors of AMAN. Results: There were 25 cases in the AIDP group and 20 cases in the AMAN group. AIDP usually started with distal limb weakness (P=0.001), and AMAN often started with limb weakness (P=0.001) and mostly accompanied by dyspnea (P=0.042). AIDP was often associated with paresthesia (P=0.001) and autonomic dysfunction (P=0.007). The response days of active treatment in the AIDP group and the AMAN group were (1.6±0.5)d and (2.3±0.8)d (P=0.022), the improvement days were (3.6±0.8)d and (5.9±1.0)d (P=0.000), the basic cure days were (7.7±1.3)d and (9.0±0.8)d (P=0.002), the cure days were (12.3±1.1)d and (12.8±0.9)d (P=0.148). Multivariate Logistic regression analysis revealed that preceding diarrhea (OR=13.750; 95% CI 1.386-136.387), limb weakness(OR=12.000;95% CI 2.359-61.048) and limb weakness with dyspnea (OR=10.000; 95% CI 1.048-95.457) were significantly associated with the AMAN-type GBS. Conclusions: AIDP and AMAN are the main types of pregnancy complicating GBS. Most patients present with a single and benign course of disease. IVIg is generally safe and effective. Preceding diarrhea, limb weakness and limb weakness with dyspnea are the predictors of AMAN-type pregnancy complicating GBS.

[A retrospective study on misdiagnosis and prognosis of acute pregnancy complicating Guillain-Barré syndrome].

Objective: To investigate the factors of first misdiagnosis, treatment and prognosis of acute pregnancy complicating with Guillain-Barré syndrome (GBS) in order to improve the first diagnosed rate. Methods: A total of 45 acute pregnancy complicating with GBS patients were retrospectively analyzed recruited from January 2009 to October 2017 at the Tianjin Fourth Central Hospital.Patients were divided into the first diagnosis group and the first misdiagnosis group, and GBS clinical types were classified into classic and variant types to analyze the misdiagnosis factors of the first diagnosis. All patients received intravenous immunoglobulin (IVIG) treatment, and the therapeutic effect and prognosis were compared and analyzed. Results: There were 20 cases in the first diagnosis group, 25 cases in the first misdiagnosis group, 35 cases in the typical GBS group, and 10 cases in the variant GBS group.There was no statistically significant difference in the baseline data of the patients(P>0.05).The misdiagnosis factors are divided into four categories: physician factors, patient factors, disease itself factors and laboratory factors. Variant GBS is more likely to lead to misdiagnosis in the first diagnosis than typical GBS. The therapeutic effect of the first diagnosis group was better than that of the first misdiagnosis group(P<0.05).Three patients died in the first misdiagnosis group, and the rest of the pregnant patients gave birth normally, and the babies were born without congenital malformation. Conclusions: Pregnancy is one of the inducing factors of GBS. Early diagnosis and correct treatment can improve maternal and infant clinical outcomes.

[Surgical technique and outcomes of uteri retrieval from brain-dead multi-organ donors: a preclinical research of human uterine transplantation].

Objective: To evaluate the surgical technique and outcomes of uteri retrieval from brain-dead multi-organ donors.This study is a preclinical research of human living uterine transplantation. Methods: From May, 2015 to May, 2017, four uteri retrieval procedures, characterized with radical hysterectomy and uterine vascular pedicles dissection, were performed in multi-organ brain-dead donors.The uterus was the third authorized organ after the kidney and liver retrieval procedures in the first two cases.The uterine pedicles included the uterus, ovaries, fallopian tubes, the upper one-third of the vagina and internal iliac vessels or external iliac vessels.The perfusion of the uterus was conducted after the retrieval for evaluating the availability, followed by histopathological examination of the uterine issues per 30 minutes. Results: Since the uterine vein was quite difficult to identify and dissect in the first two case, which result in the rupture of triple uterine veins.Therefore, the uterine venous vessels including uterine vein connected with internal iliac vein and internal iliac arteries were selected as vascular grafts and dissected successfully in the last two cases, which could be perfused with the mixture of 4 ℃ heparinized physiological saline through each artery because of shortening the surgical time and arranging the uterine procurement as the first authorized organ procedure.Mean (SD) operative time was 152.5±39.0 min (115-215 min, n=4). Conclusion: Our preliminary experience indicated that the uterus could be retrieved from the brain-dead multi-organ donors and transplanted to the recipient.The attempt of skeletonizing the uterine veins should be replaced by dissection of internal iliac vein.

Maggot debridement therapy for the treatment of diabetic foot ulcers: a meta-analysis.

OBJECTIVE: To assess the potential efficacy of maggot debridement therapy (MDT) compared with standard care for diabetic foot ulcers (DFUs). METHOD: A meta-analysis was performed on the evidence for MDT for DFUs. Databases, including PubMed, Web of Science, the Cochrane Library, EMbase, EBSCOhost, Springer Link, ScienceDirect and Ovid-Medline, were electronically searched for randomised controlled trials, case-control studies and controlled clinical trials, up to 31 December 2012, and relevant references of the included articles were also manually searched. The literature was screened, the data were extracted and the methodological quality of the included studies was assessed. Meta-analyses were performed on the included data, for the outcomes healing rate, time to healing, incidence of infection, amputation rate and antibiotic-free days or antibiotics usage. RESULTS: Overall, four studies comparing MDT with standard therapy on a total of 356 participants were included. The results of meta-analyses suggested that the MDT group was significantly superior to the control group in the percentage of DFUs to achieve full healing (RR=1.8, 95%CI=1.07; 3.02; p=0.03), amputation rate (RR=0.41, 95%CI=0.20; 0.85; p=0.02), time to healing (RR=-3.70, 95%CI=-5.76; -1.64; p=0.0004) and number of antibiotic-free days (126.8 ± 30.3 days vs 81.9 ± 42.1 days; p=0.001); however, collated differences in incidence of infection after intervention revealed no evidence of a difference between the MDT and control groups (RR=0.82, 95%CI=0.65; 1.04, p=0.10). CONCLUSION: Although MDT may be a scientific and effective therapy in treatment of DFUs, the evidence is too weak to routinely recommend it for treatment. Large studies and sample sizes are needed to assess the efficacy and safety of MDT in the treatment of DFUs. DECLARATION OF INTEREST: There were no external sources of funding for this study. The authors have no conflicts of interest to declare with regard to this work or its contents. X. Tian and X.M. Liang contributed equally to this work.

Changes in integrins αv and α5 with Nogo-A in the rat retina after optic nerve injury.

OBJECTIVE: The purpose of this study was to investigate whether integrin levels are associated with axon regeneration after central nervous system (CNS) injury. MATERIALS AND METHODS: By using immunohistochemistry, we performed a detailed investigation of the changes in and colocalization of integrins αv and α5, with Nogo-A in the retina after optic nerve injury. RESULTS: We confirmed that integrins αv and α5 were expressed in the rat retina and colocalized with Nogo-A. After optic nerve transection, we found that integrin α5 levels increased over 7 days, but integrin αv levels remained unchanged, while Nogo-A levels increased. CONCLUSIONS: It seems that the inhibition of axonal regeneration by the Amino-Nogo-integrin signaling pathway may not occur via changes in integrin levels.

Clinical characteristics and microbiology of nosocomial enterococcal bloodstream infections in a tertiary-level hospital: a retrospective study, 2007-2019.

BACKGROUND: Enterococci are important pathogens causing nosocomial bloodstream infections (BSIs) and cannot be treated with appropriate timely empirical antibiotics due to their natural resistance to many kinds of antibiotics. AIM: To analyse the clinical characteristics and microbiological features of nosocomial bloodstream infections caused by enterococci. METHODS: The clinical characteristics and microbiological features of nosocomial enterococcal BSI patients in Xiamen University Zhongshan Hospital were examined in a case-controlled retrospective study. All patient information was collected through an electronic surveillance system. FINDINGS: A total of 199 cases were identified as nosocomial enterococcal BSIs over a period of 13 years. The incidence of BSIs fluctuated from 0.21% to 0.81%. In the distribution of wards, enterococcal BSIs in hepatobiliary surgery ranked first. Intra-abdominal diseases (odds ratio: 3.36; 95% confidence interval: 2.15-5.27; P < 0.001), chemotherapy history (4.37; 2.06-9.25; P < 0.001), and urinary catheterization (2.34; 1.52-3.61; P < 0.001) were risk factors for nosocomial enterococcal BSI acquisition. Vancomycin-resistant enterococci and linezolid-insensitive enterococci strains were not found. CONCLUSION: Patients with a history of intra-abdominal disease, chemotherapy and urinary catheterization are at higher risk of nosocomial enterococcal bloodstream infections. The enterococcus strains were still sensitive to commonly used antibiotics.

An experimental study on the relation between friction force and real contact area.

Classical laws of friction suggest that friction force is proportional to the normal load and independent of the nominal contact area. As a great improvement in this subject, it is now widely accepted that friction force is proportional to the real contact area, and much work has been conducted based on this hypothesis. In present study, this hypothesis will be carefully revisited by measuring the friction force and real contact area in-site and real-time at both normal loading and unloading stages. Our experiments reveal that the linear relation always holds between friction force and normal load. However, for the relation between friction force and real contact area, the linearity holds only at the loading stage while fails at the unloading stage. This study may improve our understanding of the origin of friction.

Influence of dopants Ti and Ni on bonding interactions and dehydrogenation properties of lithium alanate.

We report a study of the influence of Ti and Ni dopants on the stability and bonding interactions of LiAlH(4) using the first-principles method. Both the Ti and the Ni prefer to occupy an interstitial site in the LiAlH(4) owing to lower occupation energies estimated from the total energy calculations. Calculations show that the bonding interactions between the Al and the H atoms within the [AlH(4)] groups were significantly reduced by the dopants, and both the stability and the geometry of the [AlH(4)] group were distorted in the doped LiAlH(4) systems. However, Ti and Ni use different mechanisms to improve the dehydrogenation properties of LiAlH(4). The Ti dopant tends to interact with the Al atom in its neighbouring [AlH(4)] to 'free' the H atoms from these [AlH(4)] groups. The effect of Ni dopant on the stability and the bonding interactions of the LiAlH(4) is due to the induction of the Ni d electrons that could cause a bonding interaction between the Ni and the Al atoms, strengthening the interactions between the Li and the H atoms, and 'freeing' the H atoms from the neighbouring [AlH(4)] groups as well.

The motility of esophageal sphincters during liquid and solid bolus swallows: a multicenter normative value study of high-resolution manometry in China.

BACKGROUND: It is gradually accepted that solid bolus swallow needs to be added to the procedure of manometry. The motility differences in the upper esophageal sphincter (UES) and lower esophageal sphincter (LES) were not well described. Sierra Scientific Instruments solid-state high-resolution manometry (HRM) system, the most popular HRM system in China, lacks the Chinese normative values for both liquid and solid bolus swallow parameters. METHODS: The esophageal HRM data of 88 healthy volunteers were analyzed. The parameters of both sphincters in resting stage were summarized and those during solid and liquid swallows were compared. KEY RESULTS: Normative HRM values of sphincter parameters in solid and liquid bolus swallows in China were established. The UES residual pressure of solid bolus swallows was lower than that of liquid bolus (0.3±5.5 mm Hg vs 4.8±5.9 mm Hg, P=.000). The time parameters of UES relaxation between two types of bolus swallows were similar. In solid bolus swallows, the intrabolus pressure (IBP) (13.8±5.1 mm Hg vs 10.9±5.7 mm Hg, P=.000) and LES relaxation time (11.0±2.1 seconds vs 8.7±1.3 seconds, P=.000) were higher. The 4-second integrated relaxation pressure between both bolus swallows was similar. CONCLUSIONS & INFERENCES: The function of the UES and LES between solid and liquid bolus swallows is different. Chinese HRM parameters are different from the Chicago Classification (http://www.chictr.org.cn, Number ChiCTR-EOC-15007147).

Occupancy of the cancer cell urokinase receptor (uPAR): effects of acid elution and exogenous uPA on cell surface urokinase (uPA).

The development of a simple, sensitive fluorimetric assay for the measurement of cell surface-associated urokinase plasminogen activator (uPA) on viable, adherent HCT116 cells in microtitre plates, after a preincubation with purified human plasminogen is described. The assay determines plasmin activity by the cleavage of H-D-Val-Leu-Lys 4-aminomethyl coumarin under near physiological pH and ionic conditions with a sensitivity in the range of 5-100 mIU uPA/well at excitation 355 nm and emission 460 nm. Plasmin generated during the assay converted all cell-surface sc-uPA to tc-uPA, allowing the determination of total uPA activity. Inhibitor studies (PAI-2, amiloride or Glu-Gly-Arg chloromethylketone) confirmed the specificity of the uPA assay. Removal of these agents prior to assay allowed determination of the cell surface sc-uPA:tc-uPA ratio. Cell surface activity was only partially removed by acid elution. This corresponded with the loss of a number of proteins and uPA-containing species as detected by SDS-PAGE, gelatin enzymography and Western blotting. Although the major protein species eluted had a M(r) of 55 kDa, reacted with a commercial anti-human uPA mAb and correlated with the main lytic zone, other higher M(r) species were also eluted from HCT116 cells. Exogenous uPA increased cell-surface activity markedly on cells previously treated with acid. Following acid elution, cell surface uPA activity was restored after 30h in culture suggesting either de novo synthesis or release of pre-formed uPA with subsequent secretion and binding to uPAR. The assay has enabled studies on adherent cells to address questions about the regulation and expression of cell-surface uPA.

The accumulation of P-element-induced recombinants in the germline of male Drosophila melanogaster.

P-element-induced recombination in Drosophila melanogaster occurs premeiotically. Recombinants are therefore expected to accumulate in the stem cells of the germline of P-element-carrying males. We show that both the recombination frequency and the incidence of "clustering" increase with the age of males carrying various P-element derivatives. The combination of end-deleted elements can lead to average recombination frequencies >50% with individual instances of 100% recombination. These elements also lowered the fertility of the carriers. We investigated these features by constructing an analytical and a computer simulation model of the course of events in the germline, incorporating the recently proposed hybrid element insertion (HEI) model of P-element activity. The model is able to predict extreme recombination levels, segregation ratio biases and lowered fertility through cell death in a single analysis.

In vitro estrogenic activities of Chinese medicinal plants traditionally used for the management of menopausal symptoms.

The estrogenic activity of 70% EtOH extracts of 32 traditional Chinese medicinal plants, selected according to their reported efficacy for the treatment of menopausal symptoms, was assessed using a recombinant yeast system with both a human estrogen receptor expression plasmid and a reporter plasmid. Among them, 11 (34%) species proved to be active. Polygonum cuspidatum had the highest estrogenic relative potency (RP) (3.28 x 10(-3)), followed by Rheumpalmatum (3.85 x 10(-4)), Cassia obtusifolia (3.49 x 10(-4)), Polygonum multiflorum (2.87 x 10(-4)), Epimedium brevicornum (2.30 x 10(-4)), Psoralea corylifolia (1.90 x 10(-4)), Cynomorium songaricum (1.78 x 10(-4)), Belamcanda chinensis (1.26 x 10(-4)), Scutellaria baicalensis (8.77 x 10(-5)), Astragalus membranaceus (8.47 x 10(-5)) and Pueraria lobata (6.17 x 10(-5)). The EC(50) value of 17beta-estradiol used as the positive control was 0.205+/-0.025 ng/ml (RP=100). This study gave support to the reported efficacy of Chinese medicines used for hormone replacement therapy.

In situ hybridization with human papillomavirus using biotinylated DNA probes on archival cervical smears.

We report a method of in situ hybridization (ISH) of 10-year-old archival cervical smears with a cocktail of nick-translated human papillomavirus (HPV) DNA types 6, 11, 16, 18, and 31. The method, which does not require destaining, results in excellent preservation of morphological detail with only 2% cell loss. Methods of smear treatment and detection of the biotinylated probe with a multistep avidin-biotin-immunoperoxidase method are described. Biotinylated PBR 322 plasmid and biotinylated human DNA were used as negative and positive controls in each run. Twenty-nine of 50 smears (58%) showing changes consistent with CIN I-II were positive for HPV. Fourteen corresponding cervical biopsies were also studied by ISH, seven corresponding to HPV-positive smears and seven to HPV-negative smears. HPV DNA was demonstrated in six of seven biopsies (87%) from the positive group but none could be demonstrated in the negative group. We conclude that retrospective study can be performed on routine alcohol-fixed, Papanicolaou-stained cervical smears with biotinylated HPV probes with excellent cell preservation, minimal cell loss, and high degrees of specificity.

Primary study of neovasculature correlating with metastatic nasopharyngeal carcinoma using computer image analysis.

The significance of neoangiogenesis in the metastasis of nasopharyngeal carcinoma (NPC) was investigated to clarify the role neovascularity in the prognosis of NPC and the probability of antiangiogenesis preventing NPC from distant metastasis. A group of 52 patients presenting with metastatic NPC were selected and strictly paired one-to-one, in sex, age, T stage, and N stage, with another 52 patients with non-metastatic NPC, who had survived for a long time after therapy. The tumor tissues of all 104 patients were retrieved for computer-assisted, immunohistochemical analysis of tumor vasculature. Counts of the microvessels and the relative area of all microvessels per image were significantly higher in metastatic NPC than they were in curable, non-metastatic NPC, while the average area of the microvessels and their average perimeter of in metastatic NPC were smaller than in non-metastatic disease. No significant difference in any microvessel parameter was found among the various types of metastasis. The alterations of microvessel parameters were significantly linked to the metastasis of NPC. Evaluation of neovascularity by computer image analysis may be helpful in estimating the prognosis of NPC and in determining the indicators for aggressive multimodal treatments.

Determination and identification of isoflavonoids in Radix astragali by matrix solid-phase dispersion extraction and high-performance liquid chromatography with photodiode array and mass spectrometric detection.

The isoflavonoids in Radix astragali were determined and identified by HPLC-photodiode array detection-MS after extraction employing matrix solid-phase dispersion (MSPD). As a new sample preparation method for R. astragali, the MSPD procedure was optimized, validated and compared with conventional methods including ultrasonic and Soxhlet extraction. The amounts of two major components in this herb, formononetin (6) and ononin (2), were determined based on their authentic standards. Four major isoflavonoids, formononetin (6), ononin (2), calycosin (5) and its glycoside (1), and three minor isoflavonoids, (6aR,11aR)-3-hydroxy-9, 10-dimethoxypterocarpan (7), its glycoside (3), and (3R)-7,2'-dihydroxy-3',4'-dimethoxyisoflavone-7-O-beta-D-glycoside (4), were identified based on their characteristic two-band UV spectra and [M + H], [aglycone + H]+ and [A1 + H]+ ions, etc. The combined MSPD and HPLC-DAD-MS method was suitable for quantitative and qualitative determination of the isoflavonoids in R. astragali.

Computer-assisted automatic peak recognition and result evaluation for analysis of chlorinated hydrocarbons in environmental samples.

A data manipulation method has been developed for automatic peak recognition and result evaluation in the analysis of organic chlorinated hydrocarbons with dual-column gas chromatography. Based on the retention times of two internal standards, pentachlorotoluene and decachlorobiphenyl, the retention times of chlorinated hydrocarbons can be calibrated automatically and accurately. It is very convenient to identify the peaks by comparing the retention times of samples with the calibrated retention times calculated from the relative retention indices of standards. Meanwhile, with a suggested two-step evaluation method the evaluation coefficients and the suitable quantitative results of each component can be automatically achieved for practical samples in an analytical system using two columns with different polarities and two internal standards.

Computer-assisted peak recognition for polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) in environmental samples.

A software has been developed for the peak recognition of 136 polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) after high resolution gas chromatography coupled with mass spectrometry (HRGC/HRMS). Based on the retention times of (13)C labelled 2,3,7,8-substituted PCDD/F internal standards, the retention times of all PCDD and PCDF can be calibrated automatically and accurately. Therefore, it is very convenient to identify the peaks by comparing the retention of samples and the calibrated retention times of their chromatograms. Hence, this approach is very significant because it is impossible to obtain always a standard chromatogram and PCDD/F analysis are very expensive and time consuming. The calibration results can be transferred to Excel for calculation. The approach is a first step to store costly and environmentally relevant data for future application.