[The relationship between resting heart rate and all-cause mortality among the Chinese oldest-old aged more than 80: a prospective cohort study]

Objective: To explore the association between resting heart rate(RHR) and all-cause mortality among the Chinese oldest-old aged more than 80. Methods: Using a total of seven surveys or follow-ups data (1998, 2000, 2002, 2005, 2008, 2011 and 2014) from the Chinese Longitudinal Healthy Longevity Survey (CLHLS). A total of 17 886 elderly over 80 years old were selected as subjects, their resting heart rate were measured though baseline survey and the survival outcome and death time of the subjects were followed up. The subjects were divided into 6 groups according to their resting heart rate. Cox regression model was used to estimate the effect of resting heart rate on mortality risk. The interaction of age, gender and resting heart rate was also analyzed by likelihood ratio test. Results: The age of subjects M (P₂₅, P₇₅) was 92 (86, 100) years old, including 10 531 females (58.9%) and there were 13 598 participants died, the mortality rate was 195.5 per 1 000 person-years. Multivariate Cox regression analysis showed that compared to the control group (60-69 pbm/min), the hazard ratio of the elderly are 1.06 (95%CI: 1.02, 1.11), 1.09 (95%CI: 1.04, 1.15), 1.23 (95%CI: 1.14, 1.34), 1.25 (95%CI: 1.08, 1.44) in the group of RHR between 70-79, 80-89, 90-99 and ≥100 pbm/min and P values are all less than 0.05. Likelihood ratio test showed that RHR and age had an interaction effect. (P for interaction=0.011). Conclusion: The risk of all-cause death increased with the increase of resting heart rate and this relationship was stronger between the 80-89 years old people.

BMI modifies the association between serum HDL cholesterol and stroke in a hypertensive population without atrial fibrillation

PURPOSE

Both high-density lipoprotein cholesterol (HDL-C) and body mass index (BMI) have an impact on the prevalence of stroke. However, it is unclear whether BMI can modify the relationship between HDL-C and stroke. Therefore, we aimed to assess the effect of the BMI on the association between HDL-C and stroke in a hypertensive population without atrial fibrillation (AF).

METHODS

We analyzed data of 10,925 hypertensive patients without AF from the Chinese Hypertension Registry Study. BMI was categorized as < 24 and ≥ 24 kg/m². Multivariate logistic regression and smooth curve fitting (penalized spline method) were used to analyze the association between HDL-C and stroke in different BMI groups. Subgroup analysis and interaction tests were used to explore the effect of other variables on this relationship.

RESULTS

The results showed a negative association between HDL-C and stroke in the BMI < 24 kg/m² group, but HDL-C was not associated with stroke in the BMI ≥ 24 kg/m² group. In the BMI < 24 kg/m² group, each 1 mmol/L increase in HDL-C was associated with a 50% decreased risk of stroke [odds ratio (OR) 0.50, 95% confidence interval (CI) 0.38-0.66]. No significant relationship between HDL-C and stroke was observed in the BMI ≥ 24 kg/m² group (OR 0.73, 95% CI 0.49-1.10). There was a significant interaction between BMI and HDL-C in regard to the prevalence of stroke in the hypertensive population without AF (P_Interaction = 0.027).

CONCLUSIONS

We found an inverse association between HDL-C and stroke only in the BMI < 24 kg/m² group. The finding suggested that BMI could modify the association between HDL-C and stroke in hypertensive populations without AF.

[Effect of tissue inhibitor of metalloproteinase-1 and 2 siRNA on the expression of smad2/3/4 protein in hepatic stellate cells]

Objective: To study the effect of tissue inhibitor of metalloproteinases (TIMP)-1 siRNA and TIMP-2 siRNA on the expression of smad2/3/4 protein in CCl4-induced liver fibrosis rat hepatic stellate cells (HSC). Methods: Rat's liver tissues with liver fibrosis after treatment with pre-built TIMP-1siRNA and TIMP-2 siRNA were used as the research subjects. Immunohistochemistry, Western blotting and real-time PCR were used to detect the protein and corresponding mRNA expression levels on smad2/3/4. TUNEL and α-smooth muscle actin (α-SMA) positive cells were quantified by double-labeled immunofluorescence. Analysis of variance (ANOVA) was used to compare the means between multiple groups, and the SNK test was used for the pairwise comparison of means. Results: The results of immunohistochemistry showed that the protein expressions of smad2, smad3, and smad4 in the TIMP-1 siRNA group and TIMP-2 siRNA group were significantly reduced than those of the model and the negative control group (P < 0.05). In addition, Western blotting results had also shown the same trend. The protein expression of smad2, smad3, and smad4 in the TIMP-1siRNA group and TIMP-2siRNA group were significantly reduced than those of the model and the negative control group (P < 0.01). The mRNA expression of smad2, smad3, and smad4 in TIMP-1siRNA group and TIMP-2siRNA group was significantly reduced than those of the model and negative control group (P < 0.05). Immunofluorescence showed that the apoptosis of activated HSC in the TIMP-1 siRNA group(0.014 3 ± 0.002 4) and TIMP-2 siRNA group(0.010 7 ± 0.004 4) was increased than those of the model(0) and the negative control group (0.002 4 ± 0.002 4, P < 0.05). Conclusion: TIMP-1 siRNA and TIMP-2 siRNA promote the apoptosis of activated HSCs. In addition, it also has a significant inhibitory effect on the expression of smad protein.

Same pandemic but different studies: an exploration of COVID-19 research at the early stage

OBJECTIVE

Scientific research is an essential necessity for the prevention and control of COVID-19. Accelerated paper-sharing makes it possible to explore the responses of scientific communities of different countries and their research focus. This is achieved by examining relevant publications during the early stage of the pandemic. This paper explores a timely research assessment on COVID-19 among China, USA, and EU.

MATERIALS AND METHODS

Papers indexed in PubMed and published from December 30, 2019, to March 11, 2020, were selected. Papers from China, USA, and EU were assessed by calculating the significance of items in the co-occurrence exported from VOSviewer.

RESULTS

The results showed that Chinese studies focus more on clinical manifestations, while USA and EU focus on experimental research. Furthermore, US research is more geared toward detection techniques and mathematical models, China focuses more on monitoring the epidemic situation, and EU engages in both.

CONCLUSIONS

This paper argues that the above distinctions are caused by differences in the stages of epidemic development, researchers' experience bases for formulating measures, traditions within the different medical cultures, and the distinction between "information" and "knowledge".

Effects of printing layer thickness on mechanical properties of 3D-printed custom trays

STATEMENT OF PROBLEM

The layer thickness serves as a straightforward and controllable parameter to alter the mechanical properties of 3D-printed custom trays. However, how the printing layer thickness affects the mechanical properties of the trays is not fully understood.

PURPOSE

The purpose of this in vitro study was to investigate the effects and their underlying mechanisms and to optimize the mechanical properties through modulation of the printing layer thickness.

MATERIAL AND METHODS

Polylactic acid (PLA) specimens were 3D-printed with 5 layer thicknesses from 0.1 mm to 0.5 mm. The bond, flexural, and tensile strengths were measured by using a universal test machine. Postfracture interfaces were examined by means of scanning electron microscopy. Additionally, the printing dimensional accuracy was estimated by measuring the size deviations between the printed and virtual specimens, and the printing times were recorded.

RESULTS

With increasing PLA printing layer thickness, the tensile bond strength first increased and then decreased, peaking at a thickness of 0.4 mm. While the flexural and tensile strengths decreased, the printing dimensional accuracy remained constant from 0.1 mm to 0.4 mm and then decreased at 0.5 mm. The printing time sharply decreased as printing layer thickness increased.

CONCLUSIONS

Moderate layer thickness provided the best properties for 3D-printed custom trays.

Expression, purification and characterization of three odorant binding proteins from the diamondback moth, Plutella xylostella

Odorant binding proteins (OBPs) are critical components in insect olfactory systems where they bind, solubilize and transport odorant molecules to receptors. Here, we cloned three OBPs (PxylGOBP1, PxylGOBP2 and PxylOBP24) from the diamondback moth, Plutella xylostella, one of the most destructive pests of cruciferous crops. These three OBPs were expressed in Escherichia coli as recombinant proteins, purified and characterized by fluorescence binding assays with 39 ligands including sex pheromone and plant-derived chemical compounds. PxylGOBP1 and PxylGOBP2 showed significantly different binding affinities to theses ligands, suggesting distinct binding preferences of these two general odorant binding proteins. PxylOBP24 showed no or extremely low binding activities to selected ligands, suggesting it may be involved in non-olfactory functions. Circular dichroism spectral results demonstrated that PxylGOBP1 and PxylGOBP2 shared similar secondary structures while PxylOBP24 was significantly different. This study improves our knowledge of insect OBPs, which will assist in a better understanding of insect olfactory system and developing more environmentally friendly pest control strategies for P. xylostella.

Analysis on reversible/irreversible electroporation region in lung adenocarcinoma cell model in vitro with electric pulses delivered by needle electrodes

Irreversible electroporation (IRE) is a minimally invasive tumor therapy using pulsed electric field with high intensity while the important tissues such as blood vessel, bile duct, and nerve are preserved. In addition to ablation area, reversible electroporation (RE) region is also generated using needle electrodes for pulse delivery. The goal of this work is to study the generation of RE region and ablation region on a 2D lung adenocarcinoma cell model in vitro. The tumor model is exposed to electric pulses with various number. The calcium AM and propidium iodide (PI) are examined to detect the ablation area and electroporation area, respectively. The results show that electroporation area firstly tends to plateau after approximately 50 pulses, while the ablation area continues to increase. The percentage of IRE area in total electroporation area increases with additional pulses, which means that RE region could be gradually turned into ablation area with increased pulse number. However, the percentage of IRE area only achieves to 54% for 200 pulses, which indicates that RE region still cannot be completely removed. RE and IRE thresholds appear to converge as the number of pulses increases. An equation between pulse number and the electric field threshold of ablation including the electric field threshold of RE is also provided for lung adenocarcinoma cell ablation. This work may have the value for the optimization of IRE protocols on tumor ablation.

Experimentally determined strengths of favorable and unfavorable interactions of amide atoms involved in protein self-assembly in water

Folding and other protein self-assembly processes are driven by favorable interactions between O, N, and C unified atoms of the polypeptide backbone and side chains. These processes are perturbed by solutes that interact with these atoms differently than water does. Amide NH···O=C hydrogen bonding and various π-system interactions have been better characterized structurally or by simulations than experimentally in water, and unfavorable interactions are relatively uncharacterized. To address this situation, we previously quantified interactions of alkyl ureas with amide and aromatic compounds, relative to interactions with water. Analysis yielded strengths of interaction of each alkylurea with unit areas of different hybridization states of unified O, N, and C atoms of amide and aromatic compounds. Here, by osmometry, we quantify interactions of 10 pairs of amides selected to complete this dataset. An analysis yields intrinsic strengths of six favorable and four unfavorable atom-atom interactions, expressed per unit area of each atom and relative to interactions with water. The most favorable interactions are sp2O-sp2C (lone pair-π, presumably n-π*), sp2C-sp2C (π-π and/or hydrophobic), sp2O-sp2N (hydrogen bonding) and sp3C-sp2C (CH-π and/or hydrophobic). Interactions of sp3C with itself (hydrophobic) and with sp2N are modestly favorable, while sp2N interactions with sp2N and with amide/aromatic sp2C are modestly unfavorable. Amide sp2O-sp2O interactions and sp2O-sp3C interactions are more unfavorable, indicating the preference of amide sp2O to interact with water. These intrinsic interaction strengths are used to predict interactions of amides with proteins and chemical effects of amides (including urea, N-ethylpyrrolidone [NEP], and polyvinylpyrrolidone [PVP]) on protein stability.

Biotransformation of insecticide flonicamid by Aminobacter sp. CGMCC 1.17253 via nitrile hydratase catalysed hydration pathway

AIMS

This study evaluates flonicamid biotransformation ability of Aminobacter sp. CGMCC 1.17253 and the enzyme catalytic mechanism involved.

METHODS AND RESULTS

Flonicamid transformed by resting cells of Aminobacter sp. CGMCC 1.17253 was carried out. Aminobacter sp. CGMCC 1.17253 converts flonicamid into N-(4-trifluoromethylnicotinoyl) glycinamide (TFNG-AM). Aminobacter sp. CGMCC 1.17253 transforms 31·1% of the flonicamid in a 200 mg l^-1 conversion solution in 96 h. Aminobacter sp. CGMCC 1.17253 was inoculated in soil, and 72·1% of flonicamid with a concentration of 0·21 μmol g^-1 was transformed in 9 days. The recombinant Escherichia coli expressing Aminobacter sp. CGMCC 1.17253 nitrile hydratase (NHase) and purified NHase were tested for the flonicamid transformation ability, both of them acquired the ability to transform flonicamid into TFNG-AM.

CONCLUSIONS

Aminobacter sp. CGMCC 1.17253 transforms flonicamid into TFNG-AM via hydration pathway mediated by cobalt-containing NHase.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first report that bacteria of genus Aminobacter has flonicamid-transforming ability. This study enhances our understanding of flonicamid-degrading mechanism. Aminobacter sp. CGMCC 1.17253 has the potential for bioremediation of flonicamid pollution.

Turpentine Derived Secondary Amines for Sustainable Crop Protection: Synthesis, Activity Evaluation and QSAR Study

In this study, we will report on the synthesis and application of efficient botanical agrochemicals from turpentine for sustainable crop protection. Two series of turpentine derived secondary amines were synthesized and identified by FT-IR, 1H NMR, 13C NMR, and HRMS. The herbicidal activities against Echinochloa crus-galli were evaluated. The potential toxicity of the synthesized compounds was tested by MTT cytotoxicity analysis. The effect of structure of the synthesized secondary amines and corresponding Schiff base compounds on their activities was investigated by quantitative structure-activity relationship (QSAR) study. All target products were found to be low toxicity, with similar or higher herbicidal activities than commercial herbicides diuron and Glyphosate. Results of QSAR study showed that a best four-descriptor QSAR model with R2 of 0.880 and Rloo2 of 0.818 was obtained. The four descriptors most relevant to the herbicidal activities are the min valency of a N atom, the max total interaction for a C-H bond, the relative number of aromatic bonds, and the min partial charge (Qmin).

Effect of the baseline pulse wave velocity on short term and long term blood pressure control in primary hypertension

OBJECTIVES

Arterial stiffness may affect antihypertensive response to antihypertensive treatment. However, sufficient clinical evidence is lacking. This longitudinal study aimed to evaluate the effect of baseline arterial stiffness measured by the brachial-ankle pulse wave velocity (baPWV) on response to short-term and long-term enalapril-based treatment in 3310 hypertensive adults from the China Stroke Primary Prevention Trial (CSPPT).

METHODS AND RESULTS

Blood pressure (BP) measured at three months (short-term) in 2780 subjects, and the time-average on-treatment BP in 3310 subjects during a median of 4.5-year follow-ups (long-term) were analyzed in the study. After short-term antihypertensive treatment, every 1 m/s increase in baPWV denoted a 7% and 6% decreased chance of achieving systolic BP (SBP) control (odds ratio (OR), 0.93; 95% CI 0.90, 0.96; P < 0.001) and BP control (OR, 0.94; 95% CI 0.91, 0.97; P < 0.001), respectively, after adjustment for age, gender and other variables. After long-term treatment, every 1 m/s increase in baPWV posed an 7% and 6% greater risk of failing to attain SBP control (OR, 0.93; 95% CI 0.90, 0.95; P < 0.001) and BP control (OR, 0.94; 95% CI, 0.92, 0.96; P < 0.001), respectively, not regarding for DBP control after both short- and long-term treatment. Higher baseline baPWV significantly decreased SBP reduction both after three months and the median 4.5-year treatment, while increased DBP reduction after the median 4.5-year treatment.

CONCLUSIONS

Elevated baseline baPWV significantly decreased BP response to short-and long-term treatment in adults with primary hypertensive. Arterial stiffness improvement may be an essential target to achieve adequate BP control.

Assessment of Ischemic Volumes by Using Relative Filling Time Delay on CTP Source Image in Patients with Acute Stroke with Anterior Circulation Large Vessel Occlusions

BACKGROUND AND PURPOSE

Thrombectomy up to 24 hours after stroke onset in patients with specific ischemic brain volumes remains a challenge, because many stroke centers do not apply specialized software to calculate ischemic volumes at advanced imaging. We aimed to establish the association between relative filling time delay on CTP source imaging and ischemic volume parameters and the infarct penumbra to core volume mismatch in patients with acute ischemic stroke.

MATERIALS AND METHODS

Consecutive patients with acute ischemic stroke and with M1 segment MCA with or without terminal ICA occlusions on baseline CTA and CTP within 24 hours of stroke symptom onset were included. Ischemic volumes were analyzed with software based on CTP maps. Relative filling time delay was classified into 4 grades-grade 0: relative filling time delay = 0 seconds; grade 1: relative filling time delay >0 to ≤4 seconds; grade 2: relative filling time delay >4 to ≤8 seconds; and grade 3: relative filling time delay > 8 seconds. Differences in ischemic volume parameters among relative filling time delay grades were tested.

RESULTS

We recruited 138 patients (median age, 69 years; 62.3% male). Different median volumes of the infarct core (grade 0, 7.3 mL; grade 1, 23.3 mL; grade 2, 45.7 mL; grade 3, 135 mL [P < .001]) and the penumbra (grade 0, 47.6 mL; grade 1, 90 mL; grade 2, 110 mL; grade 3, 92 mL [P = .043]) were observed among relative filling time delay grades. Target mismatch (defined by the criteria of the DEFUSE 3 trial) was identified in 71.7% of the patients (99/138). A relative filling time delay grade ≤ 1 independently predicted target mismatch, with a sensitivity of 0.79 (95% CI, 0.7-0.87) and a specificity of 0.66 (95% CI, 0.49-0.8).

CONCLUSIONS

Relative filling time delay grade based on CTP source imaging is a simple and effective parameter for evaluating ischemic volumes and target mismatch in patients with acute ischemic stroke. Further studies that compare relative filling time delay grade with clinical functional outcomes are necessary.

The Evaluation and Prediction of Laminoplasty Surgery Outcome in Patients with Degenerative Cervical Myelopathy Using Diffusion Tensor MRI

BACKGROUND AND PURPOSE

DTI has been proved valuable for the diagnosis of degenerative cervical myelopathy, whereas its capacity for predicting the outcome of surgery is still under debate. Here we conduct a prospective cohort study to analyze the capacity of DTI for evaluating and predicting laminoplasty surgery outcome for degenerative cervical myelopathy.

MATERIALS AND METHODS

We recruited 55 patients with degenerative cervical myelopathy who underwent DTI before surgery and at 3- and 6-month follow-up stages, and 20 healthy subjects. For clinical assessment, the modified Japanese Orthopedic Association scale was recorded for each patient at different stages. DTI metrics were compared between patients before surgery and healthy subjects. Spearman correlation and receiver operating characteristic were used to analyze the evaluation and prediction capacity of DTI for the modified Japanese Orthopedic Association scale, respectively. We analyzed different vertebral levels: maximal compression level, average of all compression levels, and C2 level.

RESULTS

DTI metrics were significantly different between patients before surgery and healthy subjects. Before surgery, DTI for the maximal compression level or DTI for the average of all compression levels had no significant correlation with the modified Japanese Orthopedic Association scale. For all stages, DTI at the C2 level was correlated with the modified Japanese Orthopedic Association scale. DTI metrics at the C2 level before surgery were significantly correlated with the postoperative modified Japanese Orthopedic Association scale recovery rate. Receiver operating characteristic analysis demonstrated that fractional anisotropy at C2 was capable of predicting the postoperative modified Japanese Orthopedic Association scale recovery rate (P = .04).

CONCLUSIONS

The DTI metrics before laminoplasty surgery, especially fractional anisotropy at the C2 level, have the potential for evaluating and predicting the degenerative cervical myelopathy surgery outcome.

Capsaicin induces mitochondrial dysfunction and apoptosis in anaplastic thyroid carcinoma cells via TRPV1-mediated mitochondrial calcium overload

Anaplastic thyroid cancer (ATC) is a rare malignancy and has a poor prognosis due to its aggressive behavior and resistance to treatments. Calcium (Ca²⁺) serves as a ubiquitous cellular second messenger and influences several tumor behaviors. Therefore, Ca²⁺ modulation is expected to be a novel therapeutic target in cancers. However, whether Ca²⁺ modulation is effective in ATC therapy remains unknown. In this study, we reported that capsaicin (CAP), a transient receptor potential vanilloid type1 (TRPV1) agonist, inhibited the viability of anaplastic thyroid cancer cells. Capsaicin treatment triggered Ca²⁺ influx by TRPV1 activation, resulting in disequilibrium of intracellular calcium homeostasis. The rapidly increased cytosolic Ca²⁺ concentration was mirrored in the mitochondria and caused a severe condition of mitochondrial calcium overload in ATC cells. In addition, the disruption of mitochondrial calcium homeostasis caused by capsaicin led to mitochondrial dysfunction in ATC cells, as evidenced by the production of mitochondrial reactive oxygen species (ROS), depolarization of mitochondrial membrane potential (ΔΨm), and opening of mitochondrial permeability transition pore (mPTP). Next, the resulting release of cyt c into the cytosol triggered apoptosome assembly and subsequent caspase activation and apoptosis. It was worth noting that both TRPV1 antagonist (capsazepine) and calcium chelator (BAPTA) could attenuate aberrant Ca²⁺ homeostasis, mitochondrial dysfunction and apoptosis induced by capsaicin treatment. Thus, our study demonstrated that capsaicin induced mitochondrial calcium overload and apoptosis in ATC cells through a TRPV1-mediated pathway. The better understanding of the anti-cancer mechanisms of calcium modulation provides a potential target for the ATC therapy.

Magnesium-Dependent Promotion of H2O2 Production Increases Ecological Competitiveness of Oral Commensal Streptococci

The pyruvate oxidase (SpxB)-dependent production of H₂O₂ is widely distributed among oral commensal streptococci. Several studies confirmed the ability of H₂O₂ to antagonize susceptible oral bacterial species, including caries-associated Streptococcus mutans as well as several periodontal pathobionts. Here we report a potential mechanism to bolster oral commensal streptococcal H₂O₂ production by magnesium (Mg²⁺) supplementation. Magnesium is a cofactor for SpxB catalytic activity, and supplementation increases the production of H₂O₂ in vitro. We demonstrate that Mg²⁺ affects spxB transcription and SpxB abundance in Streptococcus sanguinis and Streptococcus gordonii. The competitiveness of low-passage commensal streptococcal clinical isolates is positively influenced in antagonism assays against S. mutans. In growth conditions normally selective for S. mutans, Mg²⁺ supplementation is able to increase the abundance of S. sanguinis in dual-species biofilms. Using an in vivo biophotonic imaging platform, we further demonstrate that dietary Mg²⁺ supplementation significantly improves S. gordonii oral colonization in mice. In summary, our results support a role for Mg²⁺ supplementation as a potential prebiotic to promote establishment of oral health-associated commensal streptococci.

[Analysis on the efficacy and safety of fibrinolytic therapy in patients with acute ST-segment elevation myocardial infarction during the COVID-19 epidemic]

Objective: To evaluate the efficacy and safety of fibrinolysis strategy in patients with acute ST-segment elevation myocardial infarction (STEMI) during the COVID-19 epidemic, and to provide reference value for optimization of fibrinolytic process on the premise of prevention and control of COVID-19 transmission, including self-protection of medical staff. Methods: The efficacy and safety of fibrinolysis were retrospectively analyzed in 7 patients with acute STEM, who hospitalized from February 29, 2020 to April 3, 2020 in the Department of Cardiology, Wuhan Union Hospital of Tongji Medical College, Huazhong University of Science and Technology. To optimize the fibrinolytic process on the premise of prevention and control of COVID-19 transmission, including self-protection of medical staff, a full-time medical team in charge of fibrinolysis under third-grade protection was established. The acute STEMI patients were treated immediately in a fixed and isolated area in emergency department before receiving green channel fibrinolysis. Blood samples for complete blood count, COVID-19 antibody test and nasopharyngeal swab samples for COVID-19 nucleic acid test were made before fibrinolysis, while the chest CT examination was accomplished after fibrinolysis. By comparing differences of time from the first electrocardiogram (ECG) to fibrinolysis before and after the improvement of fibrinolytic process, the effect of optimization of the fibrinolytic process was evaluated. Results: In the present study, seven patients with acute STEMI received fibrinolysis therapy, 6 of them achieved reperfusion and no bleeding was observed in all of the patients. Five out of the 7 patients were hospitalized after fibrinolysis, and the hospitalization days were 19.6 days on average. By following up to April 14, 2020, none of the 7 patients died. The first 2 patients were treated according to the routine medical procedure and the time from the first ECG to fibrinolysis were 201 and 106 minutes, respectively. After the optimization of the fibrinolytic process, the time from the first ECG to fibrinolysis of the last 5 patients were 42, 46, 51, 43 and 54 minutes, respectively，which was significantly shorter than that before optimization. Conclusions: During the COVID-19 epidemic, fibrinolysis in patients with acute STEMI is safe, effective and easy to implement. Therefore, it is recommended as the top priority for the patients with acute STEMI with indications for fibrinolysis. On the premise of prevention and control of COVID-19 transmission, including self-protection of medical staff, the duration of myocardial ischemia can be shortened by optimization of the fibrinolytic process.

[Effect of alprostadil in early wound healing of rats with deep partial-thickness scald]

Objective: To explore the effect of alprostadil in early wound healing of rats with deep partial-thickness scald. Methods: Ninety specific pathogen free healthy Sprague-Dawley rats (half males and half females) were divided into sham scald group, simple scald group, and alprostadil group using the random number table with 30 rats in each group. Rats in sham scald group were sham injured, and rats in the other 2 groups were inflicted with deep partial-thickness scald of 30% total body surface area on the back. Immediately after scald, rats in the 3 groups received anti-shock treatment. Two hours post scald, rats in sham scald group and simple scald group were injected intraperitoneally with 1 mL normal saline, and rats in alprostadil group were injected intraperitoneally with 1 mL alprostadil injection, once a day and continued for 14 days. On post scald day (PSD) 3, 7, and 14, 10 rats in each group were collected for observing the general wound conditions and the wound healing rates of rats in 2 scald groups were calculated, abdominal aortic blood of 2 mL from each rat were collected to detect serum thromboxane B2 by enzyme-linked immunosorbent assay, and wound tissue on the back was collected to examine pathomorphological change by hematoxylin-eosin staining and to detect wound microvessel density (MVD) by immunohistochemical staining. Data were statistically analyzed with analysis of variance of factorial design, t test, Kruskal-Wallis H test, Mann-Whitney U test, and Bonferroni correction. Results: (1) There was no scald wound in rats in sham scald group. On PSD 3, wounds of rats in simple scald group and alprostadil group formed dry eschar. On PSD 7 and 14, wound areas of rats in alprostadil group were significantly smaller than those of rats in simple scald group, and with less exudation. (2) On PSD 3, the wound healing rates of rats in simple scald group and alprostadil group were similar (t=1.167, P>0.05). On PSD 7 and 14, the wound healing rates of rats in alprostadil group were significantly higher than those in simple scald group (t=8.657, 33.050, P<0.01). (3) On PSD 3, 7, and 14, the levels of serum thromboxane B2 of rats in simple scald group and alprostadil group were (541±22), (607±47), (688±21), (326±25), (271±21), (135±27) pg/mL, significantly higher than (17±6), (16±4), (16±4) pg/mL of rats in sham scald group (t=72.977, 39.685, 102.076, 37.033, 37.253, 13.845, P<0.01). On PSD 3, 7, and 14, the levels of serum thromboxane B2 of rats in alprostadil group were significantly lower than those in simple scald group (t=20.637, 20.651, 51.680, P<0.01). (4) Normal epidermis and dermis were seen in rats in sham scald group. On PSD 3, a large number of necrotic tissue and inflammatory cells infiltration were seen in wounds of rats in simple scald group, while a little new epithelium formation and some inflammatory cells infiltration were seen in wounds of rats in alprostadil group. On PSD 7 and 14, the new epithelium of rats in alprostadil group was significantly thicker than that in simple scald group, and epidermis formed gradually in alprostadil group. (5) On PSD 3, 7, and 14, the wound MVD of rats in simple scald group and alprostadil group were significantly higher than those in sham scald group (Z=-3.780, -3.781, -3.780, -3.780, -3.781, -3.780, P<0.01). On PSD 3, the wound MVD of rats in simple scald group and alprostadil group were similar (Z=-1.965, P>0.05). On PSD 7 and 14, the wound MVD of rats in alprostadil group were significantly higher than those in simple scald group (Z=-3.780, -3.780, P<0.01). Conclusions: The early intervention with alprostadil can significantly improve microcirculation of deep partial-thickness scald wound, reduce inflammatory cell infiltration, promote the formation of new blood vessels, thus promoting wound healing.

Social exclusion influences conditioned fear acquisition and generalization: A mediating effect from the medial prefrontal cortex

Fear acquisition and generalization play key roles in promoting the survival of mammals and contribute to anxiety disorders. While previous research has provided much evidence for the repercussions of social exclusion on mental health, how social exclusion affects fear acquisition and generalization has received scant attention. In our study, participants were divided into two groups according to two Cyberball paradigm conditions (exclusion/inclusion). Both groups underwent a Pavlovian conditioning paradigm, functional near-infrared spectroscopy (fNIRS), and skin conductance response (SCR) assessments. We aimed to determine the effects of social exclusion on fear acquisition and generalization and whether modulation of the medial prefrontal cortex (mPFC) mediates this relationship. Our results showed that socially excluded participants featured significantly higher and lower shock risk scores to safety stimuli (conditioned stimulus, CS-) and threatening stimuli (CS+), respectively, than did socially included subjects during fear acquisition. The exclusion group had increased skin conductance responses (SCRs) to CS and exhibited heightened shock risk and increased SCRs to generalized stimuli compared with the inclusion group. The fNIRS results demonstrated that the CS ​+ ​evoked larger oxy-Hb changes in the mPFC in the inclusion group than in the exclusion group during fear acquisition. Furthermore, the oxy-Hb of left mPFC of CS ​+ ​mediated the effect on the association between social exclusion and perceived risk of CS+ in the fear acquisition. Our results indicate that social exclusion impairs fear acquisition and generalization via the mediation of the mPFC and that social exclusion increases susceptibility to anxiety disorders through bias processing of fear discrimination in fear acquisition and generalization. By studying the role of social relationship in fear acquisition and generalization, our research provides new insights into the pathological mechanisms of anxiety disorder.