透皮给药实心微针阵列的紫外压印工艺方法

文中提出了一种紫外压印技术成型透皮给药实心微针的工艺方法,以C-coating光刻胶作为微针成型的原材料,采用微机电技术加工的聚二甲基硅氧烷(PDMS)微针模具,探究了紫外压印实验中影响微针成型质量的工艺条件。实验结果表明,利用C-coating光刻胶抽真空12 min以上,紫外曝光170~200 s时,制备的紫外压印微针的高度能达到230μm。通过纳米压痕力学测试和猪皮离体皮肤穿刺实验,证明这种紫外压印微针的针尖在承受50 mN的力时没有发生断裂破坏现象,并且能够顺利刺入猪皮达到良好的透皮给药效果,为紫外压印技术成型透皮给药微针提供了一定的技术参考。

The gut microbiome and metabolome of Himalayan Griffons(Gyps himalayensis):insights into the adaptation to carrion-feeding habits in avian scavengers

Background:Himalayan Griffons(Gyps himalayensis),large scavenging raptors widely distributed in Qinghai-Tibetan Plateau,have evolved a remarkable ability to feed on carcasses without suffering any adverse effects.The gut microbiome plays an important role in animal physiological and pathological processes,and has also been found to play a health protective role in the vulture adaptation to scavenging.However,the microbial taxonomic diversity(including nonculturable and culturable microbes),functions,and metabolites related to Himalayan Griffons have not been fully explored.Methods:In the present study,the 28 fecal samples of the Himalayan Griffons and 8 carrion samples were collected and sequenced using high-throughput 16 S rRNA gene sequencing methods to analyze the composition and functional structures of the microbiomes.Twelve fecal samples of the Himalayan Griffons were analyzed using untargeted Liquid Chromatography Mass Spectroscopy(LC-MS)to identify metabolites.We used different culture conditions to grow Himalayan Griffons gut microbes.Inhibitory effects of gut beneficial bacteria on 5 common pathogenic bacteria were also tested using the Oxford cup method.Results:According to the results of the culture-independent method,a high abundance of four major phyla in Himalayan Griffons were identified,including Fusobacteria,Firmicutes,Bacteroidetes,and Proteobacteria.The most abundant genera were Fusobacterium,followed by Clostridium_sensu_stricto_1,Cetobacterium,Epulopiscium,and Bacteroides.The predicted primary functional categories of the Himalayan Griffons'gut microbiome were associated with carbohydrate and amino acid metabolism,replication and repair,and membrane transport.LC-MS metabolomic analysis showed a total of 154 metabolites in all the fecal samples.Cultivation yielded 184 bacterial isolates with Escherichia coli,Enterococcus faecium,Enterococcus hirae,and Paeniclostridium sordellii as most common isolates.Moreover,7 potential beneficial gut bacteria isolated showed certain inhibition to 5 common pathogenic bacteria.Conclusions:Our findings broaden and deepen the understanding of Himalayan Griffons'gut microbiome,and highlighted the importance of gut microbiome-mediated adaptation to scavenging habits.In particular,our results highlighted the protective role of gut beneficial bacteria in the Himalayan Griffons against pathogenic bacteria that appear in rotten food resources.

Measurement of the neutron total cross section of^(9)Be at the Back-n white neutron source of CSNS

The neutron total cross section data of^(9)Be are essential in the nuclear structure model research of light nuclei and nuclear power installations.The neutron total cross section of^(9)Be in the 0.3 eV−120 MeV energy region has been measured using time-of-flight and transmission methods with the Neutron Total Cross Sectional Spectrometer(NTOX)based on the multi-cell fast fission chamber at the China Spallation Neutron Source(CSNS)-Back-n white neutron source(Back-n).The fission count-neutron energy distributions of ^(235)U and ^(238)U without samples and with Be samples with three thicknesses were measured in the double-bunch operation mode for a beam power of 100 kW.The Bayesian method was used to eliminate the influence of the double-bunch problem on neutron measurement in the energy region above 10 keV.The neutron total cross section of^(9)Be results was consistent with ENDF/B-VIII.0 evaluation library data in the 0.3 eV−20 MeV energy region.In the energy ranges of 0.3 eV to 10 keV and 0.01 to 20 MeV,the deviations between our results and the evaluation results of ENDF/B-VIII.0 were within 2.5%and 15%,respectively.In the resonance energy region,the measured resonance energies in our experiment were 0.63,0.82,and 2.8 MeV,respectively.The results showed that the total cross section uncertainties of three Be samples were within 2.2%in the energy region below 1 MeV.The total cross section uncertainty of 30 mm Be from ^(235)U was the smallest and less than 5%in the energy region of 0.3 eV−120 MeV.The results of this experiment can provide technical support for further data analysis and related nuclear data evaluation.

Reproduction strategy of nocturnal marine molluscs:running for love

The cost of reproduction is the core driver of life history evolution in animals.This paper demonstrates that the cumulative distance moved and the duration of movement of sexually immature abalones,Haliotis discus hannai,kept in various male and female groups,were significantly higher than those of sexually mature individuals,except when kept in mixed cultures of mature males and females.After mixed-culture,sexually mature males moved significantly further and for a longer duration than mature female abalones,and even more so than mature male abalones of any other group.Examination of the LC-MS metabolomics of mature males cultured with sexually mature females(AM)and those cultured with sexually immature females(JM)showed that cyclic adenosine monophosphate(cAMP)acted as a differential metabolic biomarker.After 24-h uninterrupted sampling,the concentration of 5-HT and the expression levels of the 5-HT2 and 5-HT6 receptors in AM were significantly higher than those in JM.After further injection of 5-HT2 and 5-HT6 receptor antagonists,the concentrations of cAMP and PKA rose again,but the cumulative movement duration and distance of male abalones decreased significantly,showing that 5-HT was involved in the regulation of movement behavior of male abalones through the 5-HT2 and 5-HT6 receptor-activated cAMP-PKA pathways.The results demonstrated a significant increase in the movement endurance of mature male abalones cultured with mature females,providing a theoretical basis for understanding the adaptive life history strategies of abalones and suggesting ways to protect diverse benthic resources for abalones during the reproductive stage.

Risk factors and molecular epidemiology of canine rabies in Beijing

Rabies is a serious public health problem in Asia and Africa.Approximately 99%of cases result from a bite by an infected dog.The high rabies risk countries are generally characterized by rapid urbanization;however,the prevalence and risk factors for rabies in urban dogs in developing countries remain unclear.Beijing,the capital of China,has been undergoing rapid urbanization,and implemented compulsory rabies immunization for dogs on October 1,2014.We evaluated the effects of this immunization policy and investigated the dynamics and determinants of the spread of dog rabies virus(RABV)in Beijing.Between 2013 and 2018,the positive rate of rabies in biting dogs declined significantly;79.6%of these were stray dogs.Reconstructed spatiotemporal diffusion for RABV presents a more central distribution within Beijing and a surrounding dissemination of virus lineage toward suburban areas,indicating that rabies is self-sustaining in Beijing.Continuous RABV phylogeographic reconstructions and logistic regression analysis of rabies cases revealed that rabies tended to remain in commercial areas,high-rise residences,demolition areas,and high-GDP,high-population and high-accessibility areas.Demolition areas,where many residents have abandoned their pets,are recognized as high-risk areas for rabies.Our findings reveal that the implementation of the immunization policy in Beijing has been effective in prevention and control of canine rabies,and because the prevalence of canine rabies results from multiple factors,emphasize the important role of multi-sectoral cooperation in rabies prevention and control.

驯化复合微生物菌群处理废弃钻井泥浆活性研究

【背景】油田废弃钻井泥浆含油量高,污染物复杂,环境危害严重,现有技术无法满足日益发展的石油开采行业在废弃钻井泥浆处理方面的需求。生物法处理废弃钻井泥浆,工艺简单,成本低,但也存在局限,包括广谱性差、处理周期长、原油降解率低、泥浆性质波动冲击工艺稳定性等。【目的】构建一种高活性和高环境耐受能力的微生物菌群,分析遗传稳定性和综合性能,提高废弃钻井泥浆处理技术水平。【方法】通过定向富集、诱导驯化的方法,提高活性群落对石油烃乳化降解效率,降低共代谢底物反馈抑制和群体感应系统敏感度,分析群落结构和活性成员的种群类别,分析乳化降解石油烃的活性对应关系。【结果】从含油量超过12g/kg、芳烃-胶质沥青含量超过80%、含盐量超过8g/kg的钻井废弃泥浆中富集得到1个活性微生物菌群,主要成员包括假单胞菌属(Pseudomonas)、根瘤菌属(Rhizobium)、红细菌属(Rhodobacter)和嗜碱还原硫素杆菌(Dethiobacter alkaliphilus),比例分别达27.44%、20.73%、8.54%和7.93%。在超过22代的连续驯化过程中,假单胞菌(Pseudomonas)、类希瓦氏菌(Alishewanella)和盐单胞菌(Halomonas)数量达92.72%,菌群结构和活性趋于稳定。处理钻井废弃泥浆5 d,土壤含油率由处理前的12403 mg/kg降低到处理后的42 mg/kg,综合脱油效率99.67%,石油烃降解率68.9%。分析微生物群落作用前后石油饱和土壤中的石油含量变化,原始含油量261 g/kg,处理后含油量305 mg/kg,脱油率99.88%。【结论】菌群驯化后活性稳定,耐受高盐环境能力强,在钻井废弃泥浆、含油土壤及油泥污染物处理方面具有很强的工业应用潜力。

Market-based instruments for ecosystem services:framework and case study in Lishui City,China

Introduction:Effective provision of ecosystem services(ES)and improvements in well-being of residents can be realized through policy interventions of stakeholder behavior.Of the several policies,market-based instruments(MBIs)have become the focus of global attention.Outcomes/others:To couple the theory with practice and solve the key problem of unclear definition of property rights,the framework of MBIs is designed.First,property rights of market creation must be clearly defined,verifiable,transferable,enforceable,and have policy continuity.Then,four key characteristics of MBIs need to be considered in the case design,namely those involving ES,stakeholders,trading mechanisms,and guarantee mechanisms.The Pledge Financing of the Right of the Ecological Public Welfare Forest(PFREPWF)in Lishui City is a typical case of China’s current marketization,which is a supplement and improvement to the ecological compensation policy.Based on clearly defined contract rights,Lishui City has realized the integration of ecological compensation and credit creation.Discussion:The case design still has the problems of lack of quantification and lack of correlations with ES.Conclusion:The theoretical and practical analysis around the market mechanism has reference value for solving market failures and providing environmental services.

Initial years'neutron-induced cross-section measurements at the CSNS Back-n white neutron source

The Back-n white neutron source(known as Back-n)is based on back-streaming neutrons from the spallation target at the China Spallation Neutron Source(CSNS).With its excellent beam properties,e.g.,a neutron flux of approximately 1.8×107 n/cm2/s at 55 m from the spallation target,energy range spanning from 0.5 eV to 200 MeV,and time-of-flight resolution of a few per thousand,along with the equipped physical spectrometers,Back-n is considered to be among the best facilities in the world for carrying out nuclear data measurements.Since its completion and commencement of operation in May 2018,five types of cross-section measurements concerning neutron capture cross-sections,fission cross-sections,total cross-sections,light charged particle emissions,in-beam gamma spectra,and more than forty nuclides have been measured.This article presents an overview of the experimental setup and result analysis on the neutron-induced cross-section measurements and gamma spectroscopy at Back-n in the initial years.

Tunable synthesis of furfurylamines orβ-amino alcohols via Ru-catalyzed N–H functionalization using biomass-derived polyols

We report the highly efficient conversion of readily available biomass-derived polyols with amines to valuable furfurylamines orβ-amino alcohols compounds using ruthenium catalysis.The reaction outcome is readily tuned by the simple addition of 4Åmolecular sieves(furfurylamines vs.β-amino alcohols)with high chemo-selectivity.The proposed reaction mechanism involves ruthenium-catalyzed hydrogen borrowing for the reduction of the imine intermediate and C–C bond cleavage of polyols via a retro-aldol process.A series of arylamines was suc-cessfully transformed into the desired products with moderate to good yields.