Recommendation Method for Contrastive Enhancement of Neighborhood Information

Knowledge graph can assist in improving recommendation performance and is widely applied in various person-alized recommendation domains.However,existing knowledge-aware recommendation methods face challenges such as weak user-item interaction supervisory signals and noise in the knowledge graph.To tackle these issues,this paper proposes a neighbor information contrast-enhanced recommendation method by adding subtle noise to construct contrast views and employing contrastive learning to strengthen supervisory signals and reduce knowledge noise.Specifically,first,this paper adopts heterogeneous propagation and knowledge-aware attention networks to obtain multi-order neighbor embedding of users and items,mining the high-order neighbor informa-tion of users and items.Next,in the neighbor information,this paper introduces weak noise following a uniform distribution to construct neighbor contrast views,effectively reducing the time overhead of view construction.This paper then performs contrastive learning between neighbor views to promote the uniformity of view information,adjusting the neighbor structure,and achieving the goal of reducing the knowledge noise in the knowledge graph.Finally,this paper introduces multi-task learning to mitigate the problem of weak supervisory signals.To validate the effectiveness of our method,experiments are conducted on theMovieLens-1M,MovieLens-20M,Book-Crossing,and Last-FM datasets.The results showthat compared to the best baselines,our method shows significant improvements in AUC and F1.

ZERNIKE ASTIGMATISM AND VISUAL PERFORMANCE IN MYOPIC EYES BY RIGID GAS PERMEABLE CONTACT LENSES WEAR

To investigate the effects of rigid-gas-permeable contact lens(RGP-CL)wear on Zernike astigmatism and visual performance in myopic eyes.Methods:A wavefront sensor was used to evaluate Zernike astigmatism for 21 eyes with minimum astigmatism and 18 eyes with moderate astigmatism under three different modes of refractive correction:the RGP-CL,spectacle lens correcting spherical equivalent(SL)and spectacle lens fully correcting spherical error and astigmatism(fSL).Contrast visual acuity was assessed with a VA tester at four contrast levels and two luminance backgrounds.Results:Compared to the SL wear,RGP-CL wear changed the main axis astigmatism(Z_(2)^(2))from
0:09-0:34 to 0.34-0.22 for the minimum astigmatism group,while the contrast VA was improved about 0.05 LogMAR(F=8:06,p<0:01).For the group with moderate astigmatism,significant reduction in Z_(2)^(2)was found for both fSL wear(t=4:78,p<0:001)and RGP-CL wear(t=6:29,p<0:0001).The changes in astigmatism were significantly correlated between the fSL and RGP-CL wears(r=0:897,p<0:0001 for Z_(2)^(-2);and r=0:643,p=0:004 for Z_(2)^(2)).Contrast VA was significantly improved for both fSL and RGP-CL wears and the improvements were significantly correlated between each other for all four contrast levels and two backgrounds.Conclusion:RGP-CL wear induces astigmatism for the eyes with minor astigmatism probably due to a correction of corneal astigmatism and thus a manifesting of the lens astigmatism.For the astigmatic eyes,RGP-CL wear has similar effect on correcting astigmatism as the spectacle lens wear with spherical-cylinder correction and also produces similar visual improvement.

Impacts of electrochemical disinfection on the viability and structure of the microbiome in secondary effluent water

Electrochemical disinfection(ECD)is a promising disinfection technique for wastewater reclamation;however,the impacts of ECD on the microbiome in secondary effluent wastewater remain unknown.In this study,Propidium monoazide-qPCR(PMA-qPCR)and the plate count method were used to evaluate the inactivation performance,and the PMA-16S rRNA gene sequences of living cells were targeted to study the microbiome.A discrepancy was found between PMA-qPCR and the plate count method in the evaluation of cell count,with increases of 1.5 to 2.2 orders of magnitude in the disinfection rate after 150 s of disinfection.However,the cell count recovered and occasionally exceeded original levels within 3 d after disinfection.Biodiversity was suppressed after ECD,but the microbiome after 150 s disinfection retained a higher level of evenness and stability in the community with a median Shannon index(>3.7).Pathogenic bacteria remained high in relative abundance even after 150 s of 25 V disinfection,but the biofilm-forming population was effectively suppressed by ECD.The co-occurrence network revealed a centralized and fragile network as disinfection persisted,demonstrating the destabilizing effects of ECD on the microbiome.Functional pathways for cell membrane synthesis and organic compound degradation were enriched after ECD.The reaction of the microbiome after ECD was similar to other disinfection techniques in terms of community structure.

在线学习服务师职业标准框架探索

2020年6月人力资源和社会保障部向社会发布我国第一个在线教育职业——在线学习服务师。本文基于学习支持相关理论,在"互联网+教育"变革视野下对该职业从业人员现状与职业需求、职业定位与特征以及职业标准框架进行了调查与探索。文章认为在线学习服务师既是互联网时代学习支持服务职能的新发展,也是驱动教学流程再造与教育服务机制变革的服务分工体系创新,具有知识密集型、高技术含量、数据驱动、职业方向多元四个特征。文章遵循《国家职业技能标准编制技术规程(2018)》的标准编制要求,构建出包括13个职业功能、3个职业方向、5个职业等级的在线学习服务师职业标准框架,指出该职业未来会呈现人机协同、基于社会协同的OMO服务供给、专项服务涌现等新特征。希望能够为在线学习服务师的职业认知、职业标准编制、职业服务模式和能力研究提供依据。

Nanoscale covalent organic polymers as a biodegradable nanomedicine for chemotherapy-enhanced photodynamic therapy of cancer

Recently, covalent-organic polymers （COPs）, which covalently cross-link different types of organic molecules to form organic network structures, have received significant attention in various fields. However, the design of COPs that allows them to act as therapeutic agents remains to be explored. In the present study, a new class of COPs was fabricated by cross-linking the photosensitizer meso-tetra（p-hydroxyphenyl） porphine （THPP） to a chemotherapeutic pro-drug, cis-platinum （IV）; the latter also acts as a reduction-responsive linker. After further conjugation with polyethylene glycol （PEG） in this one-pot reaction, we obtained THPP-Pt-PEG COPs, which can be stored in a lyophilized form and occur as stable nanoparticles in aqueous solution. The THPP-Pt-PEG COPs are effective in killing cancer cells through photodynamic treatment, and exhibited reduction-responsive degradation/drug release behaviors. Upon intravenous injection, the COPs, with a long blood circulation time, showed efficient tumor accumulation. Interestingly, we revealed that after injection of THPP-Pt-PEG COPs, tumors on mice exhibited greatly improved vascular perfusion and largely relieved tumor hypoxia, which favored subsequent photodynamic treatment. Hence, the combined chemo-photodynamic therapy of the COPs offers a remarkably improved therapeutic outcome compared to that with mono-therapies. This work presents a COP-based nanomedicine with high drug loading, lyophilizable formulation, prolonged blood half-life, efficient tumor passive homing, inherent biodegradability, and multiple therapeutic functions to achieve enhanced cancer combination therapy, with promise for clinical translation.

Ultralow detection limit and ultrafast response/recovery of the H_(2)gas sensor based on Pd-doped rGO/ZnO-SnO_(2)from hydrothermal synthesis

Hydrogen(H_(2))sensors are of great significance in hydrogen energy development and hydrogen safety monitoring.However,achieving fast and effective detection of low concentrations of hydrogen is a key problem to be solved in hydrogen sensing.In this work,we combined the excellent gas sensing properties of tin(IV)oxide(SnO_(2))and zinc oxide(ZnO)with the outstanding electrical properties of reduced graphene oxide(rGO)and prepared palladium(Pd)-doped rGO/ZnO-SnO_(2)nanocomposites by a hydrothermal method.The crystal structure,structural morphology,and elemental composition of the material were characterized by FE-SEM,TEM,xRD,XPS,Raman spectroscopy,and N2 adsorption-desorption.The results showed that the Pd-doped ZnO-SnO_(2)composites were successfully synthesized and uniformly coated on the surface of the rGO.The hydrogen gas sensing performance of the sensor prepared in this work was investigated,and the results showed that,compared with the pure Pd-doped ZnO-SnO_(2)sensor,the Pddoped rGO/ZnO-SnO_(2)sensor modified with 3 wt%rGO had better hydrogen(H_(2))-sensing response of 9.4-100 ppm H_(2)at 380℃.In addition,this sensor had extremely low time parameters(the response time and recovery time for 100 ppm H_(2)at 380℃were 4 s and 8 s,respectively)and an extremely low detection limit(50 ppb).Moreover,the sensor exhibited outstanding repeatability and restoration.According to the analysis of the sensing mechanism of this nanocomposite,the enhanced sensing performance of the Pd-doped rGO/ZnO-SnO_(2)sensor is mainly due to the heterostructure of rGO,Zno,and SnO_(2),the excellent electrical and physical properties of rGO and the synergy between rGO and Pd.

PAI-1 genetic polymorphisms influence septic patients’outcomes by regulating neutrophil activity

Background:Plasminogen activator inhibitor-1(PAI-1)plays an important role in the pathophysiology of sepsis,but the exact mechanism remains debatable.In this study,we investigated the associations among the serum levels of PAI-1,the incidence of 4G/5G promoter PAI-1 gene polymorphisms,immunological indicators,and clinical outcomes in septic patients.Methods:A total of 181 patients aged 18-80 years with sepsis between November 2016 and August 2018 in the intensive care unit in the Xinhua Hospital were recruited in this retrospective study,with 28-day mortality as the primary outcome.The initial serum level of PAI-1 and the presence of rs1799768 single nucleotide polymorphisms(SNPs)were examined.Univariate logistic regression and multivariate analyses were performed to determine the factors associated with different genotypes of PAI-1,serum level of PAI-1,and 28-day mortality.Results:The logistic analysis suggested that a high serum level of PAI-1 was associated with the rs1799768 SNP of PAI-1(4G/4G and 4G/5G)(Odds ratio[OR]:2.49;95%confidence interval[CI]:1.09,5.68).Furthermore,a high serum level of PAI-1 strongly influenced 28-day mortality(OR 3.36;95%CI 1.51,7.49).The expression and activation of neutrophils(OR 0.96;95%CI 0.93,0.99),as well as the changes in the expression patterns of cytokines and chemokine-associated neutrophils(OR:1.00;95%CI:1.00,1.00),were both regulated by the genotype of PAI-1.Conclusions:Genetic polymorphisms of PAI-1 can influence the serum levels of PAI-1,which might contribute to mortality by affecting neutrophil activity.Thus,patients with severe sepsis might clinically benefit from enhanced neutrophil clearance and the resolution of inflammation via the regulation of PAI-1 expression and activity.

Dynamic Macro-and Microgels Driven by Adenosine Triphosphate-Fueled Competitive Host-Guest Interaction

Supramolecular host–guest systems are generally at thermodynamic equilibrium states or in kinetically trapped states.Herein,we demonstrate the concept of a chemical fuel-driven competitive host–guest assembly featuring autonomous dynamics.The enabling key principle is to design a chemical fuel that possesses a high binding affinity to defeat the guest transiently,undergoes conversion to a waste product,and exhibit weak binding affinity in order to recover the original host–guest pair.By following this principle,adenosine triphosphate(ATP;chemical fuel and competitive guest),biguanidine-functionalizedβ-cyclodextrin(βCD;host),and an adamantine species(ADA;guest)have been engineered to construct dynamic adaptive macrogels or chemo-mechanochromic microgels with programmed time domains.Our reported methodology provides temporal control over the host–guest process,representing a conceptually new tool for the design of living supramolecular materials.

Analysis of the chemoprophylactic effect on close contacts of patients with active tuberculosis and positive tuberculin skin tests

Objective:The current study analyzed the chemoprophylactic effect of isoniazide on close contacts of patients with active tuberculosis and positive tuberculin skin tests(TSTs).Methods:A total of 1206 close contacts of patients with active tuberculosis and strongly-pos-itive TSTs were enrolled.The patients had chest X-ray examinations.Patients without tuberculosis and other diseases were divided into the following groups:90 patients in the prophylaxis group,who were given 300 mg of isoniazid qd(3-5 mg/kg for children)over a 10-month treatment course;and 89 patients in the control group without drug therapy.Both groups were followed for 10 years.Results:(1)There were 568 patients with negative results and 638 with positive results,includ-ing 445 with ordinarily-and moderately-positive results,and 193 with strongly-positive results(a positive rate of 52.9%[638/1206]and a strongly-positive rate of 16.0%[193/1206]).Fourteen tuber-culosis patients were identified(tuberculosis detection rate of 1.1%).(2)During the 3-year period of follow-up,there were 4 patients in the prophylaxis group and 12 patients in the control group who acquired tuberculosis(a morbidity rate of 4.7%[4/84]and 13.4%[12/89],respectively),and the dif-ference was statistically significant(χ^(2)=3.916,P=0.048).Six patients in the prophylaxis group,all of whom were children,discontinued medication use during the course of treatment due to adverse drug reactions,for an adverse drug reaction occurrence rate of 6.6%(6/90),a medication completion rate of 93.3%(84/90),and a 3-year protection ratio of 64.6%.(3)During the 4-6 year period,there were two patients in the prophylaxis group and three patients in the control group who acquired tubercu-losis(a morbidity rate of 2.5%[2/78]and 4.1%[3/73],respectively),two in the prophylaxis group and four in the control group who were lost to follow-up(a loss to follow-up rate of 2.5%[2/80]and 5.1%[4/77],respectively),and the difference was not statistically significant(χ^(2)=0.006,P=0.940;χ^(2)=0.215,P=0.643).(4)During the 7-10 year study,there was one patient in the prophylaxis group and two patients in the control group who acquired tuberculosis(a morbidity rate of 1.3%[1/72]and 3.1%[2/64],respectively),and four in the prophylaxis group and six in the control group who were lost to follow-up(a loss to follow-up rate of 5.2%[4/76]and 8.5%[6/70],respectively),and the dif-ference was not statistically different(χ^(2)=0.011,P=0.918;χ^(2)=0.176,P=0.675).(5)Within 10 years,there were 7 patients in the prophylaxis group and 17 patients in the control group who acquired tu-berculosis(a morbidity rate of 8.3%[7/84]and 21.5%[17/79],respectively;χ^(2)=4.770,P=0.029),and 6 in the prophylaxis group and 10 in the control group were lost to follow-up(the loss to follow-up rate was 7.1%[6/84]and 11.2%[10/89],respectively;χ^(2)=0.863,P=0.353).Conclusion:Close contacts of patients with active tuberculosis are at high-risk for acquir-ing tuberculosis.It is safe and effective for patients with strongly-positive TST results to undergo isoniazid chemoprophylaxis for 10 months.