Single-cell analysis reveals a unique microenvironment in peri-implantitis.

AIM: This study aimed to reveal the unique microenvironment of peri-implantitis through single-cell analysis. MATERIALS AND METHODS: Herein, we performed single-cell RNA sequencing (scRNA-seq) of biopsies from patients with peri-implantitis (PI) and compared the results with healthy individuals (H) and patients with periodontitis (PD). RESULTS: Decreased numbers of stromal cells and increased immune cells were found in the PI group, which implies a severe inflammatory infiltration. The fibroblasts were found to be heterogeneous and the specific pro-inflammatory CXCL13+ sub-cluster was more represented in the PI group, in contrast to the PD and H groups. Furthermore, more neutrophil infiltration was detected in the PI group than in the PD group, and cell-cell communication and ligand-receptor pairs revealed most neutrophils were recruited by CXCL13+ fibroblasts through CXCL8/CXCL6-CXCR2/CXCR1. Notably, our study demonstrated that the unique microenvironment of the PI group promoted the differentiation of monocyte/macrophage lineage cells into osteoclasts, which might explain the faster and more severe bone resorption in the progression of PI than PD. CONCLUSIONS: Collectively, this study suggests a unique immune microenvironment of PI, which may explain the differences between PI and PD in the clinic. These outcomes will aid in finding new specific and effective treatments for PI.

Ultra-high resistive switching current ratio and improved ferroelectricity and dielectric tunability performance in a BaTiO3/La0.7Sr0.3MnO3 heterostructure by inserting a SrCoO2.5 layer.

A BaTiO3/SrCoO2.5 (BTO/SCO) bilayer and a BTO single film were prepared by radio frequency magnetron sputtering on La0.7Sr0.3MnO3 (LSMO) buffered SrTiO3 (001) substrates. Interestingly, compared with reported BTO-based films, the BTO/SCO/LSMO heterostructure has a maximum ON/OFF current ratio of ∼945. More interestingly, compared with the BTO single layer, a larger Pr (∼18.4 µC cm-2) and larger dielectric tunability (∼71.9%) were achieved in the BTO/SCO bilayer. The improved performance may be attributed to the large tetragonality and improved oxygen vacancy concentrations in the BTO/SCO/LSMO heterostructure. Furthermore, our BTO/SCO/LSMO stacks exhibit potential for flexible electronic informational devices.

[Establishment and digital simulation of upper airway in patients with adenoid hypertrophy].

Objective: To analyze the flow field characteristics of the upper airway in patients with different adenoid hypertrophy using computational fluid dynamics (CFD). Methods: From November 2020 to November 2021, the cone-beam CT (CBCT) data of 4 patients [2 males and 2 females,age range 5-7 years, mean (6.0±1.2) years] with adenoid hypertrophy who were hospitalized in the Department of Orthodontics and the Department of Otolaryngology at Hebei Eye Hospital were selected. The degree of adenoid hypertrophy in the 4 patients was divided into normal S1 (A/N<0.6), mild hypertrophy S2 (0.6≤A/N<0.7), moderate hypertrophy S3 (0.7≤A/N<0.9) and severe hypertrophy S4 (A/N≥0.9) according to the ratio of adenoid thickness to the width of nasopharyngeal cavity (A/N). The CFD model of the upper airway was established using ANSYS 2019 R1 software, and the internal flow field of the CFD model was numerically simulated. Eight sections were selected as observation and measurement planes for flow field information. Relevant flow field information includes airflow distribution, velocity variation, and pressure variation. Results: In the S1 model, the maximum pressure difference occurred in the 4th and 5th observation planes (ΔP=27.98). The lowest pressures and the maximum flow rates of S2 and S3 were located in the 6th observation plane. The airflow in S1 and S2 models completely passed through the nasal cavity. In the S3 model, the mouth-to-nasal airflow ratio was close to 2∶1. In S4 model, the airflow completely passed through the mouth; in the S1 and S2 models, hard palates were subjected to a downward positive pressure with a pressure difference of 38.34 and 23.31 Pa, respectively. The hard palates in S3 and S4 models were subjected to a downward negative pressure with a pressure difference of -2.95 and -21.81 Pa, respectively. Conclusions: The CFD model can objectively and quantitatively describe the upper airway airflow field information in patients with adenoid hypertrophy. With the increasing degree of adenoid hypertrophy, the nasal ventilation volume gradually decreased, whereas the oral space ventilation volume gradually increased, and the pressure difference between the upper and lower surfaces of the palate gradually decreased until the pressure became negative.

[Association between cord blood BPDE-DNA and neurodevelopment of children aged 0 and 2 years: A birth cohort study].

Objective: To explore the effects of mothers' exposure to polycyclic aromatic hydrocarbons during pregnancy on their children's neurobehavioral development. Methods: In November 2009 to April 2010, a total of 221 pairs of mother-newborn pairs were recruited from two cooperative hospitals in Taiyuan, and their children were followed up at age two. High performance liquid chromatography was used to determine the level of BPDE-DNA in cord blood leukocytes. The Neonatal behavioral neurological assessment (NBNA) was used to assess the neurodevelopment of newborns, and the Gesell Development Scale was used to measure neurodevelopmental indexes of 2-year-old children. NBNA includes behavior, active and passive tone, primitive reflexes and general assessment, with a total score of 40 points. The Gesell Developmental Schedules consisted of four sub-scales: motor development, adaptive behavior development, language development and personal-social behavior development. We used mean and standard deviation to describe continuous variables with normal distribution, median (interquartile range) to describe continuous variables with skewed distribution, and frequency and proportion to describe categorical variables. Restricted cubic spline models were applied to assess the dose-response relationships between maternal prenatal polycyclic aromatic hydrocarbons exposure and children's neurobehavioral development at two years old. Generalized linear models were applied to evaluate the effect of exposure to maternal prenatal polycyclic aromatic hydrocarbons exposure on children's neurobehavioral development at 0 and two years old. Results: The NBNA score was 38.0±0.8, and the scores of 2-year-old children's motor, adaptive, language and personal-social were 111.6±15.0, 110.5±14.6, 108.8±17.2 and 111.7±14.5, respectively. After adjusting for confounding factors, there is no dose-response association between the cord blood BPDE of pregnant women and neonatal NBNA scores, but there were dose-response associations between BPDE and scores of 2-year-old children's motor, adaptive, language and personal-social. A unit increase in cord blood ln (BPDE-DNA), the score of motor, adaptive, language and personal-social of 2-year-old children decreased on average by 4.54、6.29、8.41 and 7.02 points. Conclusion: Maternal exposure to polycyclic aromatic hydrocarbons during pregnancy is associated with decreased children's neurobehavioral development at two years old.

MitoQ supplementation augments acute exercise-induced increases in muscle PGC1α mRNA and improves training-induced increases in peak power independent of mitochondrial content and function in untrained middle-aged men.

The role of mitochondrial ROS in signalling muscle adaptations to exercise training has not been explored in detail. We investigated the effect of supplementation with the mitochondria-targeted antioxidant MitoQ on a) the skeletal muscle mitochondrial and antioxidant gene transcriptional response to acute high-intensity exercise and b) skeletal muscle mitochondrial content and function following exercise training. In a randomised, double-blind, placebo-controlled, parallel design study, 23 untrained men (age: 44 ± 7 years, VO2peak: 39.6 ± 7.9 ml/kg/min) were randomised to receive either MitoQ (20 mg/d) or a placebo for 10 days before completing a bout of high-intensity interval exercise (cycle ergometer, 10 × 60 s at VO2peak workload with 75 s rest). Blood samples and vastus lateralis muscle biopsies were collected before exercise and immediately and 3 h after exercise. Participants then completed high-intensity interval training (HIIT; 3 sessions per week for 3 weeks) and another blood sample and muscle biopsy were collected. There was no effect of acute exercise or MitoQ on systemic (plasma protein carbonyls and reduced glutathione) or skeletal muscle (mtDNA damage and 4-HNE) oxidative stress biomarkers. Acute exercise-induced increases in skeletal muscle peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1-α) mRNA expression were augmented in the MitoQ group. Despite this, training-induced increases in skeletal muscle mitochondrial content were similar between groups. HIIT-induced increases in VO2peak and 20 km time trial performance were also similar between groups while training-induced increases in peak power achieved during the VO2peak test were augmented in the MitoQ group. These data suggest that training-induced increases in peak power are enhanced following MitoQ supplementation, which may be related to the augmentation of skeletal muscle PGC1α expression following acute exercise. However, these effects do not appear to be related to an effect of MitoQ supplementation on exercise-induced oxidative stress or training-induced mitochondrial biogenesis in skeletal muscle.

[Comparative study on prognosis of neoadjuvant chemotherapy followed by hepatic surgery versus upfront surgery in patients with synchronous colorectal liver metastasis].

Objective: To compare the survival outcome in patients with synchronous colorectal cancer liver metastasis receiving neoadjuvant chemotherapy followed by hepatic surgery versus upfront surgery strategies. Methods: A retrospective cohort study was carried out. Data of patients undergoing surgery at the Department of Hepatopancreatobiliary Surgery Unit I of Peking University Cancer Hospital from January 2008 to December 2018 for initially resectable synchronous colorectal liver metastasis were retrospectively collected. A total of 282 cases were enrolled, including 244 in the neoadjuvant chemotherapy group, 38 in the upfront surgery first group. The overall survival (OS) and progression-free survival (PFS) of the two groups were compared. A propensity score risk adjustment was used to eliminate potential bias between groups, and the covariates including sex, age, location of primary tumor, T stage, clinical risk score (CRS), RAS gene status, adjuvant chemotherapy, and resection margin status were included for adjustment. Results: In the neoadjuvant chemotherapy group, 244 cases received 4 (1-15) cycles of chemotherapy before hepatic resection, among whom 207 cases received oxaliplatin-based regimens, 37 cases received irinotecan-based regimens, and 90 cases received combined targeted agents in the first line treatment. The median follow-up time was 30 (5-134) months, and loss of follow-up was 1%. Before adjustment, Kaplan-Meier survival analysis showed that the 1-year and 3-year OS rates in the neoadjuvant chemotherapy group (95.1% and 66.4%) were better than those in the upfront surgery first group (94.7% and 51.5%, P=0.026); 1-year and 3-year PFS rates in neoadjuvant chemotherapy group (51.0% and 23.4%) were also better than those in surgery first group (39.5% and 11.5%, P=0.039). After propensity score risk adjustment, Cox multivariate analysis indicated that neoadjuvant chemotherapy was an independent protective factor of PFS (HR=0.664, 95% CI: 0.449-0.982, P=0.040), however, neoadjuvant chemotherapy was not an independent protective factor of OS (HR=0.651, 95% CI: 0.393-1.079, P=0.096). Subgroup analysis showed that the 1-year and 3-year OS rates in the patients with response to the first line treatment (194, including complete remission, partial remission and reduction but not partial remission) (96.9% and 67.1%) were better than those in the upfront surgery group (94.7% and 51.5%, P=0.026) after adjustment. However, the 1-year and 3-year OS rates in the patients without response to the first line treatment (50, including tumor progression or enlargement) were 90.0% and 63.3%, respectively, which were not significantly different with 94.7% and 51.5% in the upfront surgery group (P=0.310) after adjustment. Conclusions: For patients with resectable synchronous colorectal cancer liver metastasis, liver resection after neoadjuvant chemotherapy can provide longer PFS than upfront surgery. Although the whole OS benefit is not significant, patients with effective neoadjuvant first-line chemotherapy have better OS than those undergoing upfront surgery.

[Analysis of risk factors for drug resistant mutations in the reverse transcriptase region in chronic hepatitis B virus-infected patients].

Objective: To analyze the risk factors that may affect the mutations in the reverse transcriptase region in chronic hepatitis B virus-infected patients. Methods: 678 hospitalized cases with chronic HBV infection who underwent HBV RT testing at Tianjin Second People's Hospital from January 1, 2016 to December 31, 2016 were collected retrospectively. Among them, 417 cases were diagnosed with chronic hepatitis B, 219 cases with liver cirrhosis and 42 cases with primary liver cancer. There were 268 cases of non-use of any antiviral therapy, 138 cases of discontinuation of antiviral drugs for 6 months or more, and 272 cases of continuous antiviral therapy. HBV genotyping and RT region mutation sites were detected by direct sequencing. The risk factors that may affect the drug resistant mutation in the HBV RT mutation, including age, genotype, antiviral drug selection and medication time, hepatitis B virus infection, and biochemical markers were analyzed by univariate analysis to screen out independent risk factors. Results: Among 678 HBV-infected cases, 290 cases (42.8%) were detected with RT-region mutation. Among them, the pre-existing drug resistant rate was 6.72%, and the drug resistant mutation rate was 23.19% in treated patients. The drug resistant mutation rate of patients with continuous antiviral therapy was 66.18%. Gene mutations highest rate for 1 ~ 5 years was 27.14% in chronic HBV patients treated with antiviral therapy. Logistic regression analysis of the factors that had led to HBV mutation showed that old age, the selection of nucleoside drugs at the beginning of treatment and medication time were the main factors affecting HBV RT mutations. Conclusion: Abnormal ALT level, HBV genotype, HBV DNA quantitative level are the main factors influencing non-drug resistant mutations. Age over 60 years old, and long-term use of low-barrier nucleoside drugs are high-risk groups for HBV resistant. Therefore, HBV resistant monitoring should be strengthened.

[Effect of tenofovir disoproxil fumarate antiviral therapy on virus-specific CD8+T Cells function in patients with chronic hepatitis B].

Objective: To observe the effect of tenofovir disoproxil fumarate (TDF) antiviral therapy on HBV-specific CD8(+)T cell function in peripheral blood of patients with HBeAg-positive chronic hepatitis B, and to assess its correlation with HBeAg sero-negativeness. Methods: Sixty-three cases with HLA-A02 restricted HBeAg-positive chronic hepatitis B who received TDF (300 mg/d) antiviral therapy were enrolled from October 2016 to July 2018. The peripheral blood CD8(+)T cells were separated at baseline and 48 weeks after treatment. The peripheral blood T cells count were detected by flow cytometry. The frequency of HBV-specific CD8(+)T cells secreting perforin, granzyme B, and interferon-γ (IFN-γ) were detected by enzyme-linked immunoblotting test. Direct and indirect contact co-culture system was established between HBV-specific CD8(+)T cells and HepG2.2.15 cells. HBV DNA was detected in the culture supernatant. Target cell mortality was calculated by lactate dehydrogenase level. Cytokines expression was detected by enzyme-linked immunosorbent assay. Virus-specific CD8(+)T cells cytokilling and non-cytokilling functions were evaluated. Measurement data of the two groups were compared by t-test or paired t-test. Results: Viral response, biochemical response, and HBeAg seroconversion rate at 48 weeks of TDF treatment were 100%, 90.48% (57/63), and 25.40% (16/63), respectively. There was no statistically significant difference in peripheral blood T cell count when compared with baseline and control group at 48 weeks of TDF treatment (P > 0.05). At 48 weeks of TDF treatment, the frequency of HBV-specific CD8(+)T cells secreting perforin, granzyme B, and IFN-γ in CHB patients was significantly higher than baseline (P < 0.001). Furthermore, the frequency of HBV-specific CD8(+)T cells secreting perforin, granzyme B, and IFN-γ was also significantly higher in CHB patients with HBeAg negative than that of non-negative (P < 0.05). HBV-specific CD8(+)T cells had induced significant down-regulation of HBV DNA in the supernatant of HepG2.2.15 cell culture (P < 0.001) and remarkable IFN-γ and interleukin-2 secretion (P < 0.05) at 48 weeks of TDF therapy in direct and indirect contact co-culture system. However, HepG2.2.15 cells death rate induced by virus-specific CD8(+)T cells was increased only in the direct contact co-culture system (21.7% ± 6.18% vs. 16.1% ± 4.15%, P < 0.001). Compared with HBeAg non-negative patients, HBeAg negative CHB patients with HBV-specific CD8(+)T cells had induced a strong decrease in HBV DNA (P < 0.001) and an increase in IFN-γ secretion level (P < 0.05). However, the target cell death proportion difference between HBeAg negative and non-negative patients was not statistically significant (P > 0.05). Conclusion: During TDF treatment, with the viral load reduction, virus-specific CD8(+)T cells cytokilling and non-cytokilling functions are significantly enhanced, and are closely related to HBeAg negative.

Blockade of fatty acid signalling inhibits lipopolysaccharide-induced macrophage recruitment and progression of apical periodontitis.

AIM: To examine the role of palmitic acid in lipopolysaccharide (LPS)-stimulated chemotaxis of macrophages and the potential contribution of saturated fatty acid in signalling during the pathogenesis of apical periodontitis. METHODOLOGY: J774, a mouse macrophage cell line, was used in the experiments. After treatment with LPS, proteolytic maturation of sterol regulatory element-binding protein-1c (SREBP-1c) and expression of fatty acid synthase (FASN) were examined by Western analysis. Levels of palmitic acid were measured by reverse phase-high performance liquid chromatography-mass spectrometry. Knockdown of SREBP-1c and FASN was accomplished by small interfering RNA technology. Secretion of CC-chemokine ligand 2 (CCL2) and cellular chemotaxis were assessed by enzyme-linked immunosorbent assay and transwell migration assay, respectively. Sulfo-N-succinimidyl oleate (SSO) treatment was used to inhibit fatty acid signalling in vitro and also in a rat model of apical periodontitis. All data were first subjected to Levene's test. In vitro data were then analysed using ANOVA followed by Tukey's multiple comparison test. Data from animal experiments were analysed by independent t-tests. The significant level was set at 0.05. RESULTS: LPS stimulated proteolytic maturation of SREBP-1c and FASN expression in macrophages and significantly enhanced palmitic acid synthesis (P < 0.05). Knockdown of SREBP-1c attenuated LPS-enhanced FASN expression. Knockdown of FASN significantly suppressed LPS-enhanced palmitic acid synthesis (P < 0.05). LPS and exogenous palmitic acid significantly enhanced CCL2 secretion and macrophage chemotaxis (all P < 0.05). Inhibition of FASN expression significantly alleviated LPS-augmented CCL2 secretion (P < 0.05). SSO significantly suppressed CCL2 secretion and macrophage chemotaxis augmented by LPS and palmitic acid (all P < 0.05). In a rat model of induced apical periodontitis, SSO treatment significantly attenuated progression of apical periodontitis and macrophage recruitment (all P < 0.05). CONCLUSIONS: LPS/SREBP-1c/FASN/palmitic acid signalling contributed to tissue destruction caused by bacterial infection. Modulation of lipid metabolism and signalling may be helpful for the management of apical periodontitis.

Large Isospin Asymmetry in

ß-delayed one-proton emissions of ^{22}Si, the lightest nucleus with an isospin projection T_{z}=-3, are studied with a silicon array surrounded by high-purity germanium detectors. Properties of ß-decay branches and the reduced transition probabilities for the transitions to the low-lying states of ^{22}Al are determined. Compared to the mirror ß decay of ^{22}O, the largest value of mirror asymmetry in low-lying states by far, with δ=209(96), is found in the transition to the first 1^{+} excited state. Shell-model calculation with isospin-nonconserving forces, including the T=1, J=2, 3 interaction related to the s_{1/2} orbit that introduces explicitly the isospin-symmetry breaking force and describes the loosely bound nature of the wave functions of the s_{1/2} orbit, can reproduce the observed data well and consistently explain the observation that a large δ value occurs for the first but not for the second 1^{+} excited state of ^{22}Al. Our results, while supporting the proton-halo structure in ^{22}Al, might provide another means to identify halo nuclei.

[Long-term outcomes of patients undergoing hepatectomy for bilateral multiple colorectal liver metastases-a propensity score matching analysis].

Objective: Liver is the most common site of distant metastasis in colorectal cancer patients. Currently, surgical resection of colorectal liver metastasis (CRLM) still remains the most curative therapeutic option which is associated with long-term survival. However, the outcome of CRLM patients with bilobar multiple lesions has been reported to be extremely poor due to the complex techniques of the surgery and the difficulties to achieve a negative resection margin. In this study, postoperative long-term outcome in patients with bilobar versus unilobar multiple CRLM undergoing surgical resection were compared and the prognostic factors of CRLM were analyzed. Methods: A retrospective cohort study was performed. The clinicopathological data were collected retrospectively from patients with multiple CRLM who received liver resection between January 2002 and November 2018 at our department. Inclusion criteria: (1) All CRLM lesions were confirmed by preoperative enhanced CT or MRI and enhanced ultrasonography. (2) All CRLM lesions were resectable either initially or converted by systemic treatments. The CRLM patients were considered as resectable, if their extrahepatic diseases were able to be completely removed. (3) Sufficient remnant liver volume was required to maintain normal liver function, which was defined by the ratio of remnant liver volume to total liver volume (RLV-TLV), of greater than 30% in general or 40% for the patients undergoing chemotherapy. (4) Medical records and follow-up information were intact. Those undergoing multiple operations after recurrence, with R2 resection, or with a single CRLM lesion were excluded. Patients were divided into bilobar and unilobar group according to tumor distribution. One-to-one propensity score matching (PSM) was performed to balance the covariates between the bilobar group and unilobar group. After PSM, the differences in long-term outcomes between the two groups were compared. Results: A total of 491 patients met the inclusion criteria, 344 (69.6%) with bilobar and 147 (30.4%) with unilobar CRLM. In the propensity-score-matched population (bilobar, 143; unilobar, 143), baseline characteristics were similar between the two groups. The 1-, 3-, and 5-year overall survival rates in the bilobar group were 91.6%, 52.1%, and 35.3% respectively, compared with 93.7%, 56.8%, and 43.8% in the unilobar group, and the difference was not statistically significant (P=0.204). The 1-, 3-, and 5-year recurrence-free survival rates in the bilobar group were 45.7%, 33.7%, and 33.7% respectively, compared with 62.5%, 44.1%, and 42.1% in the unilobar group, and the difference was not statistically significant (P=0.075). No significant difference was found in liver-only recurrence (45.6% in bilobar vs. 53.3% in unilobar, P=0.543). Univariate analysis showed that N stage of primary tumor, diameter of the largest liver metastases, carcinoembyonic antigen level, RAS gene status and clinical risk score (CRS) were significantly associated with the prognosis of CRLM (all P<0.05). Multivariate analysis indicated that diameter of largest liver metastases > 5 cm (HR=1.888, 95% CI: 1.251-2.848, P=0.002), CRS≥3 (HR=1.552,95% CI:1.050-2.294, P=0.027) and RAS gene mutation (HR=1.561, 95% CI: 1.102-2.212, P=0.012) were independent risk factors of poor overall survival after hepatectomy. Conclusions: Tumor distribution may not affect the prognosis of multiple CRLM after resection. Surgical removal in patients with bilobar multiple CRLM provides comparable long-term survival to unilobar multiple CRLM.

MiR-193 promotes cell proliferation and invasion by ING5/PI3K/AKT pathway of triple-negative breast cancer.

OBJECTIVE: Triple-negative breast cancers (TNBC) are a subtype of breast cancer lacking of estrogen receptor (ER), progesterone receptor (PR), and human EGF-like receptor 2 (HER2). MiR-193 always acted as an oncogene and promoted toxic aldehyde accumulation and tyrosine hydroxylase dysfunction. The purpose of this study is to explore the function of miR-193 in triple-negative breast cancer. PATIENTS AND METHODS: Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was performed to examine the mRNA level of miR-193 expression in 50 cases of TNBC tissues and para-cancerous specimens. Also, the relation between miR-193 level and the overall survival of TNBC patient was analyzed. MiR-193 mimic and miR-193 inhibitor oligos, as well as the corresponding negative control, were synthesized from RiboBio (Guangzhou, China). RESULTS: MiR-193 expression was higher in triple-negative breast cancer tissues and cell lines than the corresponding adjacent non-tumor tissues and normal cell lines. Upregulation of miR-193 predicted poor prognosis of TNBC patients. Overexpression of miR-193 promoted cell proliferation and invasion, while that was suppressed by the knockdown of miR-193. MiR-193 binds to the 3'-UTR of an inhibitor of growth family member 5 (ING5) mRNA to mediate the expression of ING5 in TNBC cells. The knockdown of miR-193 inhibited cell invasion-mediated epithelial-mesenchymal transition (EMT). Furthermore, the knockdown of miR-193 suppressed cell proliferation through the ING5/phosphatidylinositol 3-hydroxy kinase/protein kinase B (PI3K/AKT) signal pathway. CONCLUSIONS: MiR-193 enhanced cell invasion-mediated EMT and improved cell proliferation through the ING5/PI3K/AKT signal pathway in triple-negative breast cancer. The newly identified miR-193/ING5/PI3K/AKT axis provides novel insight into the pathogenesis of triple-negative breast cancer.

[Epidemiological investigation on a cluster epidemic of COVID-19 in a collective workplace in Tianjin].

Objective: To investigate and analysis the epidemiological characteristics of a cluster epidemic of COIVD-19 in a collective workplace in Tianjin, evduate the prevention and control measures based on limited evidence and experience in early period of COVID-19 epidemic. Methods: Descriptive research method was used to describe the distribution and other epidemiological characteristics of the cluster cases of COVID-19. Results: Since the onset of the first index case on January 15, ten confirmed COVID-19 cases had occurred in the workplace, and the epidemic had spread from the workplace to 4 families, infecting 7 family members. The median age of 17 cases was 55 (19-79) years. All the 10 employee cases were males, and in the family cases, 3 were males and 4 were females. Of the employee cases, 8 worked in CW workshop and 2 worked in administrative office building. The median exposure-onset interval of all the cases was 4 days, and the median exposure-onset interval was 4.5 days in the employee cases and 4 days in the family cases. The median onset-medical care seeking interval was 4 days in the non-isolated cases, 2.5 days in the cases with home isolation after onset, and 0.5 day in the cases with home isolation before onset. Conclusions: The clustering of COVID-19 cases was observed in this workplace in Tianjin, which affected 4 families. In the early stage of the epidemic, accurate and rapid blocking and control measures can completely prevent the large-scale spread of COVID-19.

Correlations of the severity of diabetic retinopathy with EPO, Caspase-3 expression and oxidative stress.

OBJECTIVE: To investigate the relationships of the severity of diabetic retinopathy with erythropoietin (EPO), Caspase-3 expression, and oxidative stress. PATIENTS AND METHODS: A total of 20 patients with non-proliferative diabetic retinopathy hospitalized from January 2017 to January 2018 were enrolled as observation group 1, 20 patients with proliferative diabetic retinopathy were chosen as observation group 2, and 20 patients with idiopathic macular hole were selected as control group. After admission, patients received all necessary examinations and underwent vitrectomy during which vitreous and retinal tissues were taken, and venous blood was collected. Then, the content of EPO, Caspase-3, nitric oxide (NO), and malondialdehyde (MDA) was detected through enzyme-linked immunosorbent assay (ELISA), the messenger ribonucleic acid (mRNA) levels of EPO, Caspase-3, NO, and MDA were measured via quantitative Polymerase Chain Reaction (qPCR), and the severity of diabetic retinopathy was evaluated by diabetic retinopathy grading score. RESULTS: Observation group 1 and 2 had significantly decreased the content of EPO (p<0.05) and overtly increased Caspase-3, NO, and MDA content (p<0.05) in comparison with control group. Compared with those in observation group 1, the EPO content was clearly lowered in observation group 2 (p<0.05), and the content of Caspase-3, NO, and MDA was evidently elevated (p<0.05). The diabetic retinopathy grading score was remarkably lower in control group than that in both observation group 1 and observation group 2 (p p<0.05), and it was significantly enhanced in observation group 2 compared with that in observation group 1 (p<0.05). Correlation analysis showed that the EPO content was negatively correlated with the severity of diabetic retinopathy, while the content of Caspase-3, NO, and MDA was positively related to the severity of diabetic retinopathy. CONCLUSIONS: The severity of diabetic retinopathy has a negative association with EPO and positive correlations with Caspase-3, NO, and MDA content.

Current outcomes when optimizing 'standard' sample preparation for single-particle cryo-EM.

Although high-resolution single-particle cryo-electron microscopy (cryo-EM) is now producing a rapid stream of breakthroughs in structural biology, it nevertheless remains the case that the preparation of suitable frozen-hydrated samples on electron microscopy grids is often quite challenging. Purified samples that are intact and structurally homogeneous - while still in the test tube - may not necessarily survive the standard methods of making extremely thin, aqueous films on grids. As a result, it is often necessary to try a variety of experimental conditions before finally finding an approach that is optimal for the specimen at hand. Here, we summarize some of our collective experiences to date in optimizing sample preparation, in the hope that doing so will be useful to others, especially those new to the field. We also hope that an open discussion of these common challenges will encourage the development of more generally applicable methodology. Our collective experiences span a diverse range of biochemical samples and most of the commonly used variations in how grids are currently prepared. Unfortunately, none of the currently used optimization methods can be said, in advance, to be the one that ultimately will work when a project first begins. Nevertheless, there are some preferred first steps to explore when facing specific problems that can be more generally recommended, based on our experience and that of many others in the cryo-EM field.