Insight into structure evolution of carbon nitrides and its energy conversion as luminescence

A series of carbon nitride(CN)materials represented by graphitic carbon nitride(g-C3N4)have been widely used in bioimaging,biosensing,and other fields in recent years due to their nontoxicity,low cost,and high luminescent quantum efficiency.What is more attractive is that the luminescent properties such as wavelength and intensity can be regulated by controlling the structure at the molecular level.Hence,it is time to summarize the related research on CN structural evolution and make a prospect on future developments.In this review,we first summarize the research history and multiple structural evolution of CN.Then,the progress of improving the luminescence performance of CN through structural evolution was discussed.Significantly,the relationship between CN structure evolution and energy conversion in the forms of photoluminescence,chemiluminescence,and electrochemiluminescence was reviewed.Finally,key challenges and opportunities such as nanoscale dispersion strategy,luminous efficiency improving methods,standardization evaluation,and macroscopic preparation of CN are highlighted.

Evaluation of the Clinical Efficacy of Full Femtosecond Laser Surgery in the Treatment of Myopia

Objective:To evaluate the clinical effect of full femtosecond laser surgery in the treatment of myopia patients.Methods:120 myopia patients admitted to our hospital from January 2022 to June 2023 were selected.According to the random number table method,60 patients in the observation group underwent full femtosecond laser surgery,and 60 patients in the control group underwent femtosecond laser-assisted in situ keratomileusis(FS-LASIK)surgery.The clinical effects of the two groups were compared.Results:10 days postoperatively and 6 months after operation,the visual acuity level of the observation group was higher than that of the control group,the postoperative corneal asphericity coefficient and corneal full-thickness were lower than those of the control group,and the total effective rate 6 months after operation was higher than that of the control group(P<0.05).Conclusion:Full femtosecond laser surgical treatment can improve the postoperative visual acuity of patients with myopia,enhance the corneal asphericity coefficient(Q)and corneal full-thickness,and exert significant clinical effects.

Computational fluid dynamics-discrete element method simulation of stirred tank reactor for graphene production

Liquid phase exfoliation(LPE)process for graphene production is usually carried out in stirred tank reactor and the interactions between the solvent and the graphite particles are important as to improve the production efficiency.In this paper,these interactions were revealed by computational fluid dynamics–discrete element method(CFD-DEM)method.Based on simulation results,both liquid phase flow hydrodynamics and particle motion behavior have been analyzed,which gave the general information of the multiphase flow behavior inside the stirred tank reactor as to graphene production.By calculating the threshold at the beginning of graphite exfoliation process,the shear force from the slip velocity was determined as the active force.These results can support the optimization of the graphene production process.

Analysis of the Efficacy of Triamcinolone Acetonide Combined with Ranibizumab in the Treatment of Fundus Diseases

Objective:To analyze the effect of triamcinolone acetonide combined with ranibizumab in patients with fundus diseases.Methods:100 patients with fundus diseases admitted from January 2018 to January 2023 were selected.The patients were separated into two groups according to the random number table method,with 50 cases in the control group(treated with ranibizumab),and 50 cases in the observation group(treated with triamcinolone acetonide combined with ranibizumab).The clinical effects of both treatment regimens were compared.Results:The time taken for symptom disappearance of the observation group was shorter than that of the control group(P<0.05).The observation group had higher naked-eye visual acuity(4.18±0.89)compared to the control group.Besides,the observation group also had lower intraocular pressure(14.19±1.33 mmHg)and retinal thickness(283.14±3.29μm),with(P<0.05)compared to the control group.Moreover,the observation group had a lower adverse reaction rate and a higher quality of life(P<0.05).Conclusion:The application of triamcinolone acetonide combined with ranibizumab treatment can quickly relieve the clinical symptoms of patients with fundus disease,improve visual acuity,intraocular pressure,and retinal thickness,with low adverse reaction rate and better prognosis and quality of life.

高通量测序分析PIK3CA突变型与野生型结直肠癌的肠道菌群特征

目的:采用16S rDNA二代高通量测序技术,研究PIK3CA突变型与野生型结直肠癌患者中的肠道菌群特征。方法:选取2016年12月至2017年12月华中科技大学同济医学院附属协和医院结直肠癌患者19例,采用16S rDNA高通量测序技术分析PIK3CA突变型(n=4)和PIK3CA野生型(n=15)之间肿瘤组织中微生物多样性和组成差异。结果:在门水平上,结直肠癌患者的肠道菌群主要由变形菌门、栖热菌门、放线菌门、厚壁菌门和拟杆菌门组成,占总群落的98%以上。Alpha多样性分析显示,PIK3CA突变型与野生型结直肠癌患者之间微生物多样性有显著性差异,且PIK3CA突变型患者中微生物多样性明显高于野生型。Beta多样性分析显示PIK3CA突变型与野生型结直肠癌患者的肿瘤微生物特征有显著性差异。Spearman关联网络分析结果显示,在PIK3CA野生型结直肠癌肿瘤组织中,双歧杆菌属与假单胞菌呈正相关。结论:PIK3CA突变型与野生型结直肠癌患者肿瘤组织中的微生物群落结构有显著性差异,且PIK3CA突变患者中的肠道微生物多样性更丰富。

从“经济人”走向“教育人”——论“教育人”的实践逻辑

人性假设代表一门学科理论的基本出发点、命题特征与逻辑倾向,并以此影响理论建构与实践。“经济人”假设在教育理论与教育实践中具有深远影响,却陷入了从“个人利益最大化”的经济学假设起点推导“教以成人”教育目的的逻辑悖论,“经济人”逻辑指导下的教育实践显性资源收益性导向违背了育人的初衷、短周期的反馈形式加剧了教育实践的短视、单一的培养目标造就了单向度的人等问题,使其虽具有较高接受度但却易使教育实践走向功利主义。“教育人”是基于教育理论与实践提出的人性假设,“教育人”逻辑更具教育实践与教育学的“合理性”,更符合新时代对教育提出的新要求。通过宏观层面遵循新时代对教育的新导向,中观层面构建牵引性教育反馈机制,微观层面明晰协整性教育多元评价体系相结合,最终达到以经济实践手段促进教育目标、实现“教以成人”的核心目的。

Nocturnal Low-levelWinds and Their Impacts on Particulate Matter over the Beijing Area

Three-month wind profiles, 260 m PM_1 concentrations [i.e., particulate matter(PM) with an aerodynamic diameter ≤1μm], and carrier-to-noise ratio data at two Beijing sites 55 km apart(urban and suburban) were collected to analyze the characteristics of low-level nocturnal wind and PM in autumn and winter. Three mountain-plain wind events with wind shear were selected for analysis. The measurements indicated that the maximum wind speeds of the northerly weak low-level jet(LLJ) below 320 m at the suburban site were weaker than those at the urban site, and the LLJ heights and depths at the suburban site were lower than those at the urban site. The nocturnal 140 m mean vertical velocities and the variations in vertical velocity at the urban site were larger than those at the suburban site. A nocturnal breeze with a weak LLJ of ～3 m s^(-1) noticeably offset nocturnal PM transport due to southerly flow and convergence within the northern urban area of Beijing. Characteristics of the nocturnal LLJ, such as start-up time, structure, intensity, and duration, were important factors in determining the decrease in the nocturnal horizontal range and site-based low-level variations in PM.

Platelet rich plasma-complexed hydrogel glue enhances skin wound healing in a diabetic rat model

Diabetic patients often exhibit delayed or incomplete progress in the healing of acute wounds,owing to poor blood perfusion.Platelet-rich plasma(PRP)has attracted much attention as a means to improve wound healing,because it contains high growth factor concentrations.However,the burst-like release of PRP growth factors results in a short halflife of these therapeutic proteins,thus greatly limiting the therapeutic effect.In this study,we prepared PRP from human umbilical cord blood and developed an in situ photocrosslinkable PRP hydrogel glue(HNPRP)by adding a photoresponsive hyaluronic acid(HA-NB)into PRP.The HNPRP hydrogel allowed for controlled release of plateletderived growth factor-BB(PDGF-BB)and transforming growth factor-β(TGF-β)for up to 28 days.In vitro cell culture showed that HNPRP promoted migration of fibroblasts and keratinocytes as well as PRP and did not reveal the advantages of HNPRP.However,in a diabetic rat skin wound model,HNPRP treatment promoted faster wound closure.Furthermore,the HNPRP group,compared with the control,PRP and hydrogel only groups,showed significantly greater re-epithelialization and numbers of both newly formed and mature blood vessels.The HNPRP group also displayed higher collagen formation than did the control group.In conclusion,HNPRP enhances angiogenesis and skin regeneration and consequently achieves faster wound healing,thus extending its potential for clinical applications to treat diabetic skin wounds.

Recent advances in the development of in vitro liver models for hepatotoxicity testing

Liver injury is a common cause of drug approval withdrawal during drug development,pre-clinical research,and clinical treatment.If not properly treated,patients with severe liver injury can suffer from acute liver failure or even death.Thus,utilization of the convenient in vitro hepatotoxicity assessment model for early detection of drug-induced hepatotoxicity is vital for drug development and safe personalized medication.Biomaterials(e.g.,hydrogels,nanofibers,decellularized liver matrix)and bioengineering technologies(e.g.,microarrays,micropatterns,3D printing,and microfluidics)have been applied for in vitro hepatotoxicity assessment models.This review summarizes the structure and functions of the liver as well as the components of in vitro hepatotoxicity assessment models.In addition,it highlights the latest advances in developing hepatotoxicity models with the ultimate goal of further clinical translation.

Antithrombotic Therapy:Focus on the Elderly

Advanced age brings a higher incidence of thrombosis-related diseases.Although antithrombotic therapy significantly reduces the risk of ischemic events,relatively higher bleeding rates result in increased mortality and worse prognosis in the elderly.Thus the benefits and harms of antithrombotic drugs should to be carefully evaluated.In this review,we summarize current evidence and updated guidelines regarding antithrombotic therapy in the aging population.

Embedding Implicit User Importance for Group Recommendation

Group recommendations derive from a phenomenon in which people tend to participate in activities together regardless of whether they are online or in reality,which creates real scenarios and promotes the development of group recommendation systems.Different from traditional personalized recommendation methods,which are concerned only with the accuracy of recommendations for individuals,group recommendation is expected to balance the needs of multiple users.Building a proper model for a group of users to improve the quality of a recommended list and to achieve a better recommendation has become a large challenge for group recommendation applications.Existing studies often focus on explicit user characteristics,such as gender,occupation,and social status,to analyze the importance of users for modeling group preferences.However,it is usually difficult to obtain extra user information,especially for ad hoc groups.To this end,we design a novel entropy-based method that extracts users’implicit characteristics from users’historical ratings to obtain the weights of group members.These weights represent user importance so that we can obtain group preferences according to user weights and then model the group decision process to make a recommendation.We evaluate our method for the two metrics of recommendation relevance and overall ratings of recommended items.We compare our method to baselines,and experimental results show that our method achieves a significant improvement in group recommendation performance.

The Application of Novel Electrochemical Approach to Antioxidant Activity Assay of Metal Porphyrins with Bulky 3,5-Diisobornyl-4-hydroxyphenyl Moieties

The complexes of biogenic metals (Zn2+,Cu2+,Co2+,Mn3+,Fe3+) based on meso-tetra(3,5-diisobor- nyl-4-hydroxyphenyl)porphyrin 1 were synthesized. The electrochemical behavior of these com-pounds was studied using cyclic voltammetry (CV) and rotating disk electrode (RDE) techniques. The antioxidant activity of complexes was estimated by means of the electrochemical assay based on the hydrogen atom transfer reaction to the stable radical 2,2’-diphenyl-1-picrylhydrazyl (DPPH). The RDE method was applied for this process monitoring. It was shown that the efficiency of the metal complexes (Cu2+,Co2+,Mn2+,Ni2+,Fe3+) is practically the same order as that of free base porphyrin 1. However the Zn2+ complex demonstrates significantly higher antioxidant activity, and the stoichiometry of the reaction was determined as σ = 4. The results demonstrate that porphyrin macrocycle can directly affect the antioxidant properties of 2,6-diisobornylphenol.

Flexible regulation engineering of titanium nitride nanofibrous membranes for efficient electromagnetic microwave absorption in wide temperature spectrum

Simultaneous development of well impedance matching and strong loss capability has become a mainstream method for achieving outstanding electromagnetic microwave absorption(EMWA)performances over wide temperature range.However,it is difficult to pursue both due to the mutual restraint of relationship between impedance matching and loss capability about temperature.Here,we propose a flexible regulation engineering of titanium nitride(TiN)nanofibrous membranes(NMs,TNMs),which could be distributed uniformly in the polydimethylsiloxane(PDMS)matrix and contributed to the formation of abundant local conductive networks,generating the local conductive loss and enhancing the loss ability of EMWs.Moreover,when the TNMs are used as functional units and dispersed in the matrix,the corresponding composites exhibit an outstanding anti-reflection effect on microwaves.As hoped,under the precondition of good impedance matching,local conductive loss and polarization loss together improve the loss capacity at room temperature,and polarization loss can compensate the local conductive loss to acquire effective dielectric response at elevated temperature.Benefiting from the reasonably synergistic loss ability caused by flexible regulation engineering,the corresponding composites exhibit the perfect EMWA performances in a wide temperature range from 298 to 573 K.This work not only elaborates the ponderable insights of independent membrane in the composition-structure-function connection,but also provides a feasible tactic for resolving coexistence of well impedance matching and strong loss capability issues in wide temperature spectrum.

Boosted microwave absorption performance of transition metal doped TiN fibers at elevated temperature

Due to the temperature and frequency response of electromagnetic(EM)loss,how to realize the effective design of microwave absorption materials(MWAMs)at elevated temperature is highly desirable for practical applications.Herein,transition metaldoped titanium nitride(M-TiN,M=Fe or Co)fibers were fabricated,the distortion of TiN lattice could cause the adjustable charge enrichment,which played a profound influence on the dielectric response and EM microwave absorption(EMWA)performances.Benefiting from the negative correlation between dielectric loss and temperature,more loss mechanism could be introduced,which would effectively enhance dielectric loss and EMWA performances at elevated temperature.The optimal EMWA performances of Fe-TiN fibers/polydimethylsiloxane(PDMS)composites were realized with a wide temperature range(298–423 K):the reflection loss(RL)could reach 99%(RL<−20 dB)at 12.2 GHz with 1.8 mm,when the filler content was only 15.0 wt.%.Compared with the undoped-TiN fibers/PDMS and Co-TiN fibers/PDMS composites,the excellent EMWA of Fe-TiN fibers/PDMS composite could be attributed to the reasonably synergistic polarization loss and conduction loss.Based on systematic analysis of the variable-temperature EM parameters and EMWA performances,the optimization of EMWA performances in wide temperature domain could be realized by introducing appropriate polarization loss and its compensating.Hopefully,this work provides a new strategy for regulating the dielectric response and designing effective MWAMs at elevated temperature.

北京地区四个豹猫亚种群肠道菌群的组成

野生动物的肠道微生物组成受食物资源和遗传属性的影响较大,为了解北京地区小型猫科动物肠道菌群组成特点及其影响因素,本研究通过扩增细菌16S rRNA的V3‒V4高变区进行高通量测序,对云蒙山、云峰山、松山、百花山4个区域的豹猫(Prionailurus bengalensis)亚种群进行肠道菌群组成分析。结果表明,在门水平上,豹猫的肠道优势菌群主要由厚壁菌门(相对多度52.40%)、变形菌门(25.18%)、放线菌门(9.07%)、拟杆菌门(8.17%)和梭杆菌门(4.74%)组成。在属水平上,相对多度最高的前5个属为假单胞菌属(Pseudomonas,13.37%)、布劳特氏菌属(Blautia,11.20%)、梭菌属(Clostridium_sensu_stricto_1,9.10%)、消化梭菌属(Peptoclostridium,8.62%)、乳杆菌属(Lactobacillus,6.08%),共约占总多度的50%。各区域豹猫亚种群的肠道菌群β多样性不存在显著差异,松山区域的ACE指数和Chao 1指数与云蒙山和云峰山存在显著差异。鉴于松山亚种群的遗传结构与其他区域有所不同,而4个区域的气候类型和豹猫食物构成相似性高,推测该亚种群的肠道菌群主要受遗传结构分化的影响,对此还需进一步研究。

Identification of bioactive anti-angiogenic components targeting tumor endothelial cells in Shenmai injection using multidimensional pharmacokinetics

Shenmai injection(SMI)is a well-defined herbal preparation that is widely and clinically used as an adjuvant therapy for cancer.Previously,we found that SMI synergistically enhanced the activity of chemotherapy on colorectal cancer by promoting the distribution of drugs in xenograft tumors.However,the underlying mechanisms and bioactive constituents remained unknown.In the present work,the regulatory effects of SMI on tumor vasculature were determined,and the potential anti-angiogenic components targeting tumor endothelial cells(TECs)were identified.Multidimensional pharmacokinetic profiles of ginsenosides in plasma,subcutaneous tumors,and TECs were investigated.The results showed that the concentrations of protopanaxadiol-type(PPD)ginsenosides(Rb1,Rb2/Rb3,Rc,and Rd)in both plasma and tumors,were higher than those of protopanaxatriol-type(Rg1 and Re)and oleanane-type(Ro)ginsenosides.Among PPD-type ginsenosides,Rd exhibited the greatest concentrations in tumors and TECs after repeated injection.In vivo bioactivity results showed that Rd suppressed neovascularization in tumors,normalized the structure of tumor vessels,and improved the anti-tumor effect of 5-fluorouracil(5 FU)in xenograft mice.Furthermore,Rd inhibited the migration and tube formation capacity of endothelial cells in vitro.In conclusion,Rd may be an important active form to exert the anti-angiogenic effect on tumor after SMI treatment.

Reduced graphene oxide@carbon sphere based metacomposites for temperature-insensitive and efficient microwave absorption

With the increasing advance of fifth generation(5G)network and the gradual expansion of digital devices,harsh working environment for electronic devices has spawned higher requirements for microwave absorbing materials(MAMs).Since both the electromagnetic response and energy conversion character vary with temperature,to achieve temperature insensitive microwave absorption behaviour in wide temperature range has become extremely challenging.In this work,structured metacomposites containing sub-wavelength reduced graphene oxide(RGO)@carbon spheres were fabricated,and the microwave absorption was further improved through structural and composition design of the RGO@carbon units.Due to the unique anti-reflection effect on microwave of the metacomposites,the temperature-insensitive electromagnetic performance at elevated temperature could be exhibited.Moreover,both the dielectric relaxation behaviour and microwave absorption proformance of the system could be further increased.As a result,the effective absorption bandwidth(reflection loss(RL)<−10 dB)of the metacomposites with only 3.0 wt.%filler content could cover the entire X-band(8.2–12.4 GHz)frequency ranging from 298 to 473K.The metacomposite proposed in this work provides a“de-correlating”strategy to break the linkage between microwave absorption behaviour and temperature,which offers an interesting plateau for fabricating efficient high-temperature microwave absorption structures with tunable and designable advantages.

Effect of potential HONO sources on peroxyacetyl nitrate(PAN)formation in eastern China in winter

As an important secondary photochemical pollutant,peroxyacetyl nitrate(PAN)has been studied over decades,yet its simulations usually underestimate the corresponding observations,especially in polluted areas.Recent observations in north China found unusually high concentrations of PAN during wintertime heavy haze events,but the current model still cannot reproduce the observations,and researchers speculated that nitrous acid(HONO)played a key role in PAN formation.For the first time we systematically assessed the impact of potential HONO sources on PAN formation mechanisms in eastern China using the Weather Research and Forecasting/Chemistry(WRF-Chem)model in February of 2017.The results showed that the potential HONO sources significantly improved the PAN simulations,remarkably accelerated the RO x(sum of hydroxyl,hydroperoxyl,and organic peroxy radicals)cycles,and resulted in 80%–150%enhancements of PAN near the ground in the coastal areas of eastern China and 10%–50%enhancements in the areas around 35–40°N within 3 km during a heavy haze period.The direct precursors of PAN were aldehyde and methylglyoxal,and the primary precursors of PAN were alkenes with C>3,xylenes,propene and toluene.The above results suggest that the potential HONO sources should be considered in regional and global chemical transport models when conducting PAN studies.

Continuous ranking on uncertain streams

Data uncertainty widely exists in many web applications, financial applications and sensor networks. Ranking queries that return a number of tuples with maximal ranking scores are important in the field of database management. Most existing work focuses on proposing static solutions for various ranking semantics over uncertain data. Our focus is to handle continuous ranking queries on uncertain data streams： testing each new tuple to output highly-ranked tuples. The main challenge comes from not only the fact that the possible world space will grow exponentially when new tuples arrive, but also the requirement for low space- and time- complexity to adapt to the streaming environments. This paper aims at handling continuous ranking queries on uncertain data streams. We first study how to handle this issue exactly, then we propose a novel method （exponential sampling） to estimate the expected rank of a tuple with high quality. Analysis in theory and detailed experimental reports evaluate the proposed methods.

Multi-Antenna UAV Data Harvesting:Joint Trajectory and Communication Optimization

Unmanned aerial vehicle(UAV)-enabled communication is a promising technology to extend coverage and enhance throughput for traditional terres-trial wireless communication systems.In this paper,we consider a UAV-enabled wireless sensor network,where a multi-antenna UAV is dispatched to collect data from a group of sensor nodes(SNs).The objective is to maximize the minimum data collection rate from all SNs via jointly optimizing their transmission scheduling and power allocations as well as the trajectory of the UAV,subject to the practical constraints on the maximum transmit power of the SNs and the maximum speed of the UAV.The formulated optimization problem is challenging to solve as it involves non-convex constraints and discrete-value variables.To draw useful insight,we first consider the special case of the formulated problem by ignoring the UAV speed constraint and optimally solve it based on the Lagrange duality method.It is shown that for this relaxed problem,the UAV should hover above a finite number of optimal locations with different durations in general.Next,we address the general case of the formulated problem where the UAV speed constraint is considered and propose a traveling salesman problem-based trajec-tory initialization,where the UAV sequentially visits the locations obtained in the relaxed problem with minimumflying time.Given this initial trajectory,we thenfind the corresponding transmission scheduling and power alloca-tions of the SNs and further optimize the UAV trajectory by applying the block coordinate descent and successive convex approximation techniques.Finally,numerical results are provided to illustrate the spectrum and energy efficiency gains of the proposed scheme for multi-antenna UAV data harvesting,as compared to benchmark schemes.