BACKGROUND:Most of the silver coating materials prepared using active screen plasma technology in the past do not involve the nanotechnology field.The formed silver coating is in a"thin film"form,which is coated on the surface of the substrate,and the distribution of silver particles on the surface is uneven.Its long-term antibacterial ability is challenged. OBJECTIVE:To prepare nano silver coatings capable of being"buried"within stainless steel(SS)substrates using active screen plasma surface modification(ASPSM)and to observe antibacterial activity. METHODS:The nano-silver coating was prepared by ASPSM technique on stainless steel substrate.Three groups of coating samples were prepared by adjusting the bombardment time(1,2,and 4 hours),which were denoted as 1 h-Ag-ASPSM@SS,2 h-Ag-ASPSM@SS and 4 h-Ag-ASPSM@SS,respectively.The antibacterial activity of the coatings was analyzed by antibacterial ring test and Gram staining.The antibiotic coating samples of gentamicin combined with vancomycin were prepared by using stainless steel as substrate and were recorded as ACNs.Stainless steel,2 h-Ag-ASPSM@SS,and ACNs were inserted into Staphylococcus aureus or Pseudomonas aeruginosa suspension,respectively.The long-acting(84 days)antibacterial activity of the samples was analyzed by coating plate method.Bone marrow mesenchymal stem cells were co-cultured with stainless steel,2 h-Ag-ASPSM@SS,and ACNs,respectively.CCK-8 assay,dead/alive staining,and lactate dehydrogenase activity of cell supernatant were detected.Stainless steel,2 h-Ag-ASPSM@SS,and ACNs were taken after continuous exposure to Staphylococcus aureus suspension for 12 weeks.The amount of residual viable bacteria on the surface of the material was evaluated by spread plate method.Vancomycin drug sensitive disk method was used to evaluate the resistance of residual live bacteria on the surface of materials. RESULTS AND CONCLUSION:(1)With increasing bombardment time,the diameter of nano silver on the sample surface and the silver content in the coating gradually increased.Among them,the 2 h-Ag-ASPSM@SS exhibited the highest surface silver content while forming uniformly spherical nanoparticles.(2)Antibacterial ring test and Gram staining results demonstrated that compared with 1 h-Ag-ASPSM@SS and 4 h-Ag-ASPSM@SS,the 2 h-Ag-ASPSM@SS exhibited better inhibitory effect on Staphylococcus aureus and pseudomonas aeruginosa.After co-culturing with bacteria for 42 and 84 days,the number of viable bacteria on the spread plate method was significantly lower in the 2 h-Ag-ASPSM@SS group compared to the stainless steel and ACNs groups.After co-culturing with Staphylococcus aureus for 84 days and Pseudomonas aeruginosa for 42 days,the number of viable bacteria on the surface of the eluate from the ACNs group was higher than that of the stainless steel group.(3)CCK-8 assay,live/dead staining and lactate dehydrogenase activity of cell supernatant displayed that 2 h-Ag-ASPSM@SS did not have obvious cytotoxicity.ACNs showed obvious cytotoxicity.(4)After co-culture with Staphylococcus aureus for 12 weeks,the residual viable bacteria on the surface of 2 h-Ag-ASPSM@SS group was less than that of stainless steel group,and the residual viable bacteria on the surface of the ACNs group was more than that of stainless steel group.Compared with the stainless steel group,the sensitivity to vancomycin was significantly decreased in the ACNs group(P＜0.001),and there was no significant change in sensitivity to vancomycin in 2 h-Ag-ASPSM@SS group(P＞0.05).(5)The above results indicate that the silver nanoparticle coated stainless steel greatly improves the deposition efficiency of silver nanoparticles on the stainless steel surface and has long-lasting antibacterial properties and good cell compatibility.

Aim To investigate the inhibition role and mechanism of adipose derived mesenchymal stem cell(ADMSC)exosomes(Exo)on adverse ventricular remodeling after myocardial infarction(MI).Methods The chan-ges of autophagy and inflammasomes phenotype of cardiac fibroblasts after H2O2 treatment were observed.MI rats were in-jected with an equal volume of normal saline,adipose derived mesenchymal stem cell exosomes(MSC-Exo)or fibroblast exosomes(MEF-Exo)via a tail vein.The expression of autophagy related 16 like protein 1(ATG16L1),autophagy re-lated protein 7(ATG7)and NOD-like receptor protein 3(NLRP3),inflammatory response,the degree of myocardial fi-brosis,and the cardiac function were observed in different groups.Results After treatment with H2O2 on cardiac fi-broblasts,the expressions of ATG16L1 and ATG7 were significantly decreased(P＜0.001),NLRP3 was significantly in-creased(P＜0.001),and the levels of inflammatory cytokines interleukin-1β(IL-1β)and IL-18 were significantly elevated(P＜0.001).After MI rats were intervened with MSC-Exo,the expressions of autophagy related proteins ATG16L1 and ATG7 were significantly up-regulated(P＜0.001),NLRP3 was significantly down-regulated(P＜0.001),serum IL-1β and IL-18 levels were significantly decreased(P＜0.001),fibrosis-related proteins collagen Ⅰ and Ⅲ were significantly reduced(P＜0.001),myocardial fibrosis was significantly relieved(P＜0.001),and cardiac function was sig-nificantly improved(P＜0.001).Conclusion Adipose derived MSC-Exo play a role in inhibiting adverse ventricular remodeling after MI by regulating the balance of autophagy and NLRP3 inflammasomes.

【Objective】 Coronary no-reflow during percutaneous conranary intervention (PCI) often results in the failure of ischemic myocardial reperfusion and major adverse cardiovascular events (MACE). The present study sought to evaluate whether the GRACE risk score can predict coronary no-reflow in STEMI patients undergoing PCI. 【Methods】 We consecutively recruited 1 118 patients with STEMI who were admitted to Gansu Provincial People’s Hospital and The First Affiliated Hospital of Xi’an Jiaotong University from January 2009 to December 2011. Main demographic data, cardiovascular risk factors, blood lipid and other biochemical indicators were recorded. Coronary angiography was performed by a radial artery approach using the standard Judkins technique. Coronary no-reflow was evaluated by at least two independent experienced cardiologists. The GRACE risk score was calculated with a computer program. All the cases were followed up by medical records, face-to-face interviews or telephone calls. Finally, we analyzed the predictive value of the GRACE risk score for coronary non-reflow and MACE in STEMI patients undergoing PCI. 【Results】 During a median period of 36 months, 58 of the 1 118 patients (5.2%) were lost to follow-up. Of the remaining 1 060 patients, 118 (11.1%) had no-reflow and 147 (13.9%) had MACE. The GRACE score was higher in patients with no-reflow than those without no-reflow. Multivariate logistic regression established that the GRACE score was an independent predictor for coronary no-reflow (OR=1.034; P=0.002). And multivariate Cox analysis showed the GRACE score was an independent predictor of MACE. The area under the ROC curve for coronary no-reflow and MACE was 0.719 and 0.697, respectively. Kaplan-Meier analysis showed that the probability of rehospitalization for heart failure, reinfarction, all-cause death and cumulative cardiovascular events increased with the increase of the GRACE risk score. 【Conclusion】 The GRACE risk score is a readily available predictive scoring system for coronary no-reflow and MACE in STEMI patients.

Objective:To prepare 99Tc m-hydrazinonicotinamide(HYNIC)-αCD8/Fab ( 99Tc m-αCD8/Fab), and explore the predictive value of 99Tc m-αCD8/Fab SPECT/CT imaging for the efficacy of anti-programmed death-1 (PD-1) immunotherapy. Methods:The αCD8/Fab was modified with HYNIC- N-hydroxysuccinimide (NHS) and IRDye800-NHS to form HYNIC-αCD8/Fab and IRDye800-αCD8/Fab (Dye-αCD8/Fab), respectively. 99Tc m-αCD8/Fab was prepared in sodium bicarbonate buffer (pH=8.5), with SnCl 2 being used as the reducing agent. The labeling yield and radiochemical purity of 99Tc m-αCD8/Fab and its stability in PBS and fetal bovine serum (FBS) were tested in vitro. The mouse spleen and human peripheral blood lymphocytes were isolated for cell-specific binding and blocking experiments of 99Tc m-αCD8/Fab in vitro. SPECT/CT imaging was used to analyze the specific binding ability of the 99Tc m-αCD8/Fab probe in CT26 colon cancer mouse models (BALB/c). The near infrared fluorescence imaging and SPECT/CT imaging were performed to detect the intra-tumoral CD8 + T cell infiltration after anti-PD-1 therapy in tumor bearing mice, and the results were further verified by HE and immunofluorescence staining. CD8 + T cell depletion study was performed to determine the role of CD8 + T cells in the tumor responses to anti-PD-1 therapy. Two-way analysis of variance was used to compare the data difference. Results:The labeling yield of 99Tc m-αCD8/Fab was 90% with a high radiochemical purity (95%) and good stability in vitro (radiochemical purity still more than 80% after 720 min in PBS and FBS). 99Tc m-αCD8/Fab could specifically bind to mouse CD8 + T cells ((10.30±0.81) percent added radioactive dose (%AD)/10 6 cells), compared with the binding ability in human peripheral blood lymphocytes group and CD8 antibody blocking group ((1.78±0.61) and (1.59±0.25) %AD/10 6 cells; F=10.07, P<0.001). SPECT/CT imaging showed that 99Tc m-αCD8/Fab had markedly higher tumor uptake in the CT26 colon cancer mouse models. Near-infrared fluorescence imaging showed that the tumor uptake of 99Tc m-αCD8/Fab in the responsive group was significantly higher than in the nonresponsive group after anti-PD-1 treatment ((8.9±1.1)% vs (7.1±0.8)%; F=4.69, P=0.024), and SPECT/CT imaging found the similar result. HE and immunofluorescence staining of tumor and lymph nodes showed that the proportion of lymphocyte infiltration was higher in the responsive group. Furthermore, CD8 + T cell depletion significantly reversed the therapeutic effect of anti-PD-1 immunotherapy in tumor-bearing mice. Conclusions:In this study, 99Tc m-αCD8/Fab was successfully obtained. CD8-specific SPECT imaging could sensitively visualize the tumor-infiltrating CD8 + T cells, suggesting the potential application value to predict and evaluate the efficacy of immunotherapy in the clinical settings.

Objective: To describe the epidemiological characteristics of a cluster of COVID-19 cases reported in Baodi district of Tianjin as of 18 February, 2020, which might be associated with the exposure in a local department store, and provide suggestions for prevention and control strategy development. Methods: The basic characteristics, time and area distributions, clinical manifestations, epidemiological history and transmission mode of the COVID-19 cases associated with the department store exposure were analyzed. Results: A total of 40 COVID-19 cases were associated with the department store exposure, accounting for 75.47% of the total confirmed cases (53 cases) reported in Baodi district. The cases were mainly at the age of 60 years or older (35.00%) and farmers (40.00%). The main clinical manifestations included fever (95.00%), cough (35.00%), and diarrhea (15.00%). The proportion of confirmed severe cases was 32.50%. The incidence curve showed that the incidence peak occurred on 31 January, 2020. Among the 40 cases, 6(15.00%) were department store employees, 19(47.50%) were customers and 15(37.50%) were close contacts (secondary cases). The first case occurred on 21 January, 2020, this case was a department store employee who had a purchasing history at whole sale markets in other provinces and cities before the onset, and 3 employees were still on duty after symptom onsets. The median of the incubation period of customer cases was 6 days, and the median of the interval between onset and medical treatment of customer cases was 7 days. Conclusion This was a cluster epidemic of COVID-19, which might be associated with the exposure in the department store. By now, the current prevention and control measures have achieved satisfied effects.

OBJECTIVE: To investigate the expression of CDC25A in non- small cell lung cancer (NSCLC) tissues and explore its correlation with the clinicpathological features of the patients and the expressions of let-7a1 and let-7c. METHODS: We collected surgical specimens of pathologically confirmed NSCLC tissues and paired adjacent lung tissues from 44 patients and tissues of benign lung lesions from 9 patients. The expressions of CDC25A protein and mRNA in the tissues were detected by immunohistochemistry and fluorescence quantitative RT-PCR, respectively; the expressions of let-7a1 and let-7c mRNA were detected using tail-adding fluorescence quantitative RT-PCR. RESULTS: The positivity rate of CDC25A protein expression was significantly higher in NSCLC tissues than in the adjacent tissues and benign pulmonary lesions ( CONCLUSIONS The expression level of CDC25A is significantly increased in NSCLC with a negative correlation with Let-7c expression, which identifies CDC25A as a possible downstream target gene of Let-7c.
Carcinoma, Non-Small-Cell Lung/genetics* ; Gene Expression Regulation, Neoplastic ; Humans ; Lung ; Lung Neoplasms/genetics* ; Lymphatic Metastasis ; MicroRNAs ; RNA, Messenger/genetics* ; cdc25 Phosphatases

Objective To investigate the geographic landscape features in Yulong plague natural focus.Methods Four altitudinal gradients (2 400-,2 600-,2 800-,≥3 000 m) were selected as study objects in Yulong plague natural focus from December 2015 to November 2016 to collect and analyze geographic landscape factors (topography and terrain,climate,water areas,vegetation and soil) based on the literatures about this plague focus.Results Yulong plague natural focus was an area with mid-mountain and subalpine topography in northwestern Yunnan Province,and its terrain had the character of lower in the southeast and higher in the northwest.This area belonged to plateau warm temperate monsoon climate of low latitude with an average month temperature 13.6 ℃ from 2005-2016,month air relative humidity averaged 59.4％,and rainfall averaged 884.5 mm a year,which concentrated mostly from June to September.About 98.1％ of the water area in Yulong County was controlled by Chin-sha River.The vegetation and soil were characterized by vertical distribution along with altitude gradients obviously.Conclusion The unique geographical landscape of the plague natural focus in Yulong County is one of important factors affecting the occurrence and epidemic of the plague.

Objective To compare and analyze the soil eight metal elements contents of rat holes of three plague foci in Yunnan Province.Methods The soils were collected from the rat holes in Yulong,Jianchuan,and Lianghe plague foci.Calcium (Ca),iron (Fe),zinc (Zn),chromium (Cr),lead (Pb),manganese (Mn),cadmium (Cd),and copper (Cu) were quantified with flame atomic absorption spectrometry (FAAS).Data input,calculation and collation were conducted through Excel 2007,and statistical software SPSS 20.0 was used to carried out statistical analysis through rank sum test.Results The medians of Ca content in the rat hole soil of Yulong County,Jianchuan County,and Lianghe County,respectively,were 85.40,308.56,and 0.00 mg/kg;the medians of Fe were 2 569.07,1 950.16,and 975.72 mg/kg;the medians of Zn were 5.64,4.02,and 2.04 mg/kg;the medians of Cr were 1.09,3.06,and 0.71 mg/kg;the medians of Pb were 3.61,29.56,and 22.80 mg/kg;the medians of Mn were 223.01,212.97,and 80.43 mg/kg;the medians of Cd were 0.00,2.02,and 2.94 mg/kg;and the medians of Cu were 1.92,1.08,and 0.51 mg/kg.The contents of eight metal elements were statistically different in the soil samples between Yulong,Jianchuan,and Lianghe plague foci (H =80.538,127.687,202.583,185.359,124.747,150.057,91.346,228.546,P ＜ 0.05).Conclusions The content of Fe in soil of the three plague foci in Yunnan Province is abundant.The contents of metal elements of Yulong County and Jianchuan County are similar.

Objective To investigate the community structure and spatial distribution of wild myomorpha in the plague foci of Lianghe County,Yunnan Province.Methods From December 2015 to October 2016,in Mangdong,Hexi,Nangsong and other places in Lianghe County,forest landscape samples were randomly selected in different altitude gradients (1 000 ～,1 200 ～,1 400 ～,≥ 1 600 m).Peanut was used as a bait for trapping myomorpha,and the community structure of myomorpha was analyzed.Results A total of 663 myomorpha were collected and the density was 7.97％ (663/8 320),which were divided into 16 species,11 genus,5 families,and 3 orders.Rattus tanezumi (30.62％,203/663) was the dominant species.In the 1 000-＜ 1 200 m altitude gradient,the richness of myomorpha was the highest (13 kinds).In the 1 400-＜ 1 600 m altitude gradient,the index of diversity (2.094 2) was the highest.With the increase of altitude,the ecological dominance were increased,and the values were 0.672 2,0.774 2,0.842 8,and 0.882 4,respectively,whereas the evenness presented a decreasing trend,and the values were 0.269 2,0.197 1,0.142 8,and 0.162 0.Conclusions The Rattus tanezumi has presented a single dominant distribution at different elevation and the number and the species of the wild rodent with superior position have increased with the altitude increased in Lianghe focus.With the increase of altitude,the diversity and the evenness have increased,whereas the richness and the dominance have decreased.

Objective To discuss the treatment method and effect of the application of the dorsal branches island flaps of the digital arteries in clinic.Methods During January,2010 to February,2015,a total of 20 cases of palmar soft tissue defect of the 2nd-5th distal segments of single fingers were incorporated and repaired by the dorsal branches island flaps of the digital arteries in the base of the distal phalanx.The size of the selected flaps was 3.5 cm × 2.5 cm-2.0 cm × 2.0 cm.In addition,palmar soft tissue defect (n =15) of the 2nd-5th middle and distal segments of single fingers were repaired by the dorsal branches island flaps of the digital arteries at the 1/3 site of the proximal digital arteries,and the selected flaps size was 4.5 cm × 2.5 cm-3.0 cm × 2.0 cm.Full-thickness skin graft urethroplasty was used in the donor sites.Flap shape,texture,sensory recovery and texture of the skin region,function recovery of the wounded fingers were followed up at 1,3,and 6 months after operation.Results Thirty-five patients were followed up from 6 to 13 months (average of 7 months).All flaps survived completely in the incorporated 35 cases postoperatively.Flaps had satisfactory appearance,fine texture,and soft texture in the skin transplantation area.The postoperative improvement of sensory function was between S2 and S3,and the two-point discrimination was 10-15 mm.Assessment of the upper limb function using the standard issued by the Hand Surgery Society of Chinese Medical Association graded 23 cases as excellent,10 cases as good,and 2 cases as fair.Conclusion The dorsal branches island flaps of the digital arteries are characterized by easy dissection,reliable blood supply,and no major blood vessels needed to be sacrificed,which is an effective procedure for finger soft issue defect repairing.