增材制造Ti6Al4V合金的闪速等离子体电解氧化与在生理介质中的电化学行为

研究激光粉末床熔融增材制造(AM)(又称直接金属激光烧结)技术制备的Ti6Al4V合金等离子体电解氧化(PEO)处理及其电化学行为。通过短时间(<120 s)PEO处理(也称闪速PEO),在AM合金和传统合金表面制备了3~10μm厚、含Ca和P的涂层。然后在改良的α-MEM溶液中,通过动电位极化曲线和电化学阻抗谱(EIS)评估了合金的电化学行为。与传统合金相比,AM合金中形成了细小的层片状α显微组织和层间小尺寸的β相颗粒,这促使了火花的产生,从而促进了PEO涂层的生长。闪速PEO涂层提高了传统合金和AM合金的耐腐蚀性,最薄的涂层(<3μm)提供了高达3倍的保护。AM Ti6Al4V由于其高的晶界密度,易受局部缝隙腐蚀的影响。而即使短至35 s的闪速PEO处理也足以成功避免这种情况。

人工智能白内障协同管理的通用平台

目的:建立和验证一个涉及多级临床场景的白内障协作通用的人工智能(artificial intelligence,AI)管理平台,探索基于AI的医疗转诊模式,以提高协作效率和资源覆盖率。方法:训练和验证的数据集来自中国AI医学联盟,涵盖多级医疗机构和采集模式。使用三步策略对数据集进行标记:1)识别采集模式;2)白内障诊断包括正常晶体眼、白内障眼或白内障术后眼;3)从病因和严重程度检测需转诊的白内障患者。此外,将白内障AI系统与真实世界中的居家自我监测、初级医疗保健机构和专科医院等多级转诊模式相结合。结果:通用AI平台和多级协作模式在三步任务中表现出可靠的诊断性能:1)识别采集模式的受试者操作特征(receiver operating characteristic curve,ROC)曲线下面积(area under the curve,AUC)为99.28%~99.71%);2)白内障诊断对正常晶体眼、白内障或术后眼,在散瞳-裂隙灯模式下的AUC分别为99.82%、99.96%和99.93%,其他采集模式的AUC均>99%;3)需转诊白内障的检测(在所有测试中AUC>91%)。在真实世界的三级转诊模式中,该系统建议30.3%的人转诊,与传统模式相比,眼科医生与人群服务比率大幅提高了10.2倍。结论:通用AI平台和多级协作模式显示了准确的白内障诊断性能和有效的白内障转诊服务。建议AI的医疗转诊模式扩展应用到其他常见疾病和资源密集型情景当中。

郁金香的化学成分及药理活性研究进展

郁金香为百合科郁金香属球根花卉。近年来,对郁金香的研究主要集中在种质资源、引种与栽培技术、扩繁与种球复壮、育种等方面。目前的研究表明郁金香花提取液有抑菌、杀菌、助眠、保健等功效,而其关于鳞茎的药用研究主要在凝集素的分离鉴定和对淋巴细胞的促增殖作用以及5-脂氧合酶在抗炎和抗肿瘤方面的介导作用。但对其花和鳞茎的化学成分和药理活性研究相对较少,本文通过对郁金香花和鳞茎的化学成分、药理活性及药用资源研究进行总结、分析,为郁金香药用功效的深入研究奠定基础。

Effect of heat treatment on the mechanical and biocorrosion behaviour of two Mg-Zn-Ca alloys

The effect of heat treatment on the mechanical and biocorrosion behaviour of the Mg-1 wt.%Zn-1 wt.%Ca(ZX11)and Mg-3 wt.%Zn-0.4 wt.%Ca(ZX30)alloys was evaluated.For this purpose,three-point bending tests as well as electrochemical and immersion tests in Hank’s solution were performed on both alloys in four different thermal conditions:as-cast,solution-treated,peak-aged and over-aged.Microstructural examinations revealed that the as-cast ZX11 and ZX30 alloys exhibit a microstructure composed ofα-Mg grains separated by large Mg_(2)Ca and Ca_(2)Mg_(6)Zn_(3) particles and by large Ca_(2)Mg_(6)Zn_(3) particles,respectively.During solution treatment,the Ca_(2)Mg_(6)Zn_(3) precipitates at the grain boundaries(GBs)are fully dissolved in the ZX11 alloy,but mainly redistributed to form a more connected configuration in the ZX30 alloy,showing a poor age-hardening response.Consequently,after solution-treatment,galvanic corrosion and corrosion rate decreases in the former,but increases in the latter.The peak-aged condition displays the highest corrosion rate for both alloys,maybe due to an excessive number density of fine Ca_(2)Mg_(6)Zn_(3) particles acting as cathodic sites.However,the over-aged condition shows the lowest corrosion rate for the ZX11 alloy and a very similar one to that of the as-cast sample for the ZX30 alloy.The ZX11 alloy shows generally better biocorrosion behaviour than the ZX30 alloy to its lower content in the Ca_(2)Mg_(6)Zn_(3) phase and thus reduced galvanic corrosion.The Mg_(2)Ca phase present in the studied ZX11 alloy has been proved to exhibit an increased corrosion potential,which has been related to an observed enrichment with Zn.

Add-on therapy of herbal formulation rich in standardized fenugreek seed extract in type 2 diabetes mellitus patients with insulin therapy: An efficacy and safety study

Objective: To assess the safety and efficacy of herbal formulation rich in standardized fenugreek seed extract(IND-2) add-on therapy in type 2 diabetes mellitus(T2DM) patients who were on insulin treatment in prospective, single arm, open-label, uncontrolled, multicentre trial.Methods: T2DM patients(n=30) with aged 18-80 years who were stabilized on insulin treatment with fasting blood sugar(FBS) level between 100-140 mg/dL received IND-2 capsules(700 mg, thrice a day) for 16 weeks.The primary endpoints were an assessment of FBS at week 2, 4, 6, 8, 12 and 16.Secondary end-points include post-prandial blood sugar level, glycosylated Hb(HbA1c), reduction in the dose of insulin and number of hypoglycemic attacks, and improvement in lipid profile at various weeks.Safety and adverse events(AEs) were also assessed during the study.Results: Study was completed in twenty T2DM patients, and there was no significant reduction in FBS and post-prandial blood sugar level after addon therapy of IND-2.However, add-on therapy of IND-2 significantly reduced(P<0.01) the HbA1c values, requirements of insulin and hypoglycemic events as compared with baseline.Total cholesterol, high-density lipoproteins-cholesterol, and low-density lipoproteincholesterol levels were significantly increased(P<0.01) after IND-2 add-on therapy.Body weight and safety outcomes did not differ significantly in IND-2 add-on therapy group at week 16.Additionally, add-on therapy of IND-2 did not produce any serious adverse events.Conclusions: The results of present investigation suggest that add-on therapy of IND-2 with insulin in T2DM patients improves glycaemic control through a decrease in levels of HbA1c and number of insulin doses needed per day without an increase in body weight and risk of hypoglycemia.Thus, IND-2 may provide a safe and well-tolerated add-on therapy option for the management of T2DM.

Diversity of Saxicolous Lichens along an Aridity Gradient in Central México

Lichens are symbiotic organisms that comprise a fungus and a photosynthetic partner wich are recognized as a good indicator of climate change.However,our understanding of how aridity affects the diversity of saxicolous lichens in drylands is still limited.To evaluate the relationship between saxicolous lichen diversity and aridity in a central México dryland,a geographical transect was established of 100 km to build an aridity gradient in the semiarid zone of the State of Querétaro,Mexico,comprising ten sampling sites with a 10 km separation.Species richness,abundance and diversity of soil lichen species were recorded using two sampling methods:the quadrat-intercept and the line-intercept method,to compare their performance in assessing soil lichen diversity in drylands.The number of species and Shannon diversity of saxicolous lichens were higher at intermediate values of the aridity index(AI=0.10-0.34).Quadrat intercept and point intercept methods gave quite similar results,which means that the selected method does not influence the results in a significant way.This study confirms the role of saxicolous lichens as climate change indicators and reveals the importance of the sampling method selection in the evaluation of different parameters of soil lichen diversity in drylands.

CLUE-S model based on GIS applied to management strategies of territory with oil wells—Case study:Santa Elena,Ecuador

Some cities worldwide have oil wells directly affecting the management of the territory.For example,La Libertad and Salinas districts contain 467 oil wells in urban areas representing a major land-use planning challenge.The objective is to apply the CLUE-S land use model in coastal cities with oil wells(Salinas-La Libertad),using geographic information systems considering environmental and security characteristics for territorial development.The stages of the study are:i)classification and categorisation of oil wells;ii)application of the GIS-CLUE-S method and visualisation of land use dynamics;iii)use the SWOT-TOWS matrix,for the analysis of the situation and the main factors affecting the territory.The results indicate high vulnerability in many urban sectors and those close to the coastline.Furthermore,the CLUE-S analysis shows that the population growth in the urban sector is close to oil well areas,making it a complex pole of human-industry interaction that impacts the management of the territory.This study synthesises three technical aspects:some oil wells do not comply with municipal ordinance regulations;identification of vulnerable zones due to environmental and security factors,which recommends a territorial reordering policy;as well as an education plan for the application of territorial ordering policies,with awareness and sustainability projections.

Ecological intensification of agriculture through biodiversity management:introduction

A major feature of humans is that they can attain much higher population densities than any non-domestic animal species of similar body size(Damuth 1987).This is most likely due to the invention of agriculture(Herrera and Garcia-Bertrand 2018),which allowed humans to manage ecosystems in such a way that as much biomass as possible is converted into food(Vitousek et al.1986).

Indirect costs counteract the effects of pollinator-mediated phenotypic selection on corolla size in the mediterranean shrub Halimium atriplicifolium

Aims larger corollas receive more pollinator visits but involve higher production and maintenance costs,especially under hot and dry conditions.this can result in indirect costs on reproductive output,which may counteract the effects of pollinator-mediated phenotypic selection on corolla size.In this study,I explored the relationship between corolla size and indirect costs and whether these costs counteract the effects of pollinator-mediated phenotypic selection on this trait in the mediterranean shrub Halimium atriplicifolium.I hypothesized that(i)corolla production entails direct costs in dry mass,N and P,(ii)corollas entail significant indirect costs in terms of fruit and seed production,(iii)indirect costs increase with corolla size,(iv)this species may suffer pollen limitation to a certain degree and(v)indirect costs counteract the effects of pollinator-mediated selection on corolla size.Methods I compared fruit set and seed production of petal-removed flow-ers(r flowers)and unmanipulated control flowers(C flowers)and evaluated the influence of individual mean corolla size on relative fruit and seed gain of r compared to C flowers.I also estimated phenotypic selection on corolla size mediated by indirect costs and the combined effect of costs and pollinators(i.e.total selection).Important Findings Corollas allocated sizeable amount of resources in terms of dry mass relative to the other floral structures.Fruit set and seed per fruit were significantly higher in r flowers,while individual mean corolla size showed a positive relationship with relative fruit gain.Phenotypic selection analysis revealed cost-mediated negative directional selection and absence of positive directional total selection on corolla size through fruit set.this translated into stabilizing total selection.these results suggest that mediterranean environments can impose constraints on corolla size,counteracting advantages of larger corollas from the pollination point of view with increased indirect costs of such flowers.

Functional leaf and size traits determine the photosynthetic response of 10 dryland species to warming

Aims Relatively few studies so far have assessed how ongoing global warming will affect the photosynthetic performance of dryland plant species.We evaluated the effects of warming on the photosynthetic rates of 10 species with contrasting functional attributes,and whether their functional traits modulated photosynthetic responses to warming.Methods A common garden experiment was conducted over 2 years with distinct environmental conditions(drier vs.wetter year).The experiment was designed as a randomized block design with two treatments:warming(control vs.~2.9℃ temperature increase)and species(Agropyron cristatum,Festuca ovina,Lygeum spartum,Medicago sativa,Plantago lanceolata,Psoralea bituminosa,Sanguisorba minor,Hedysarum coronarium,Dorycnium pentaphyllum and Phlomis herba-venti).We linked functional traits measurements with temporal variations in photosynthetic responses to warming.Important Findings In the drier year,warming increased photosynthetic rates at the beginning of the growing season,suggesting a modification in the growing period(earlier spring).In the wetter year,functional traits modulated photosynthetic responses to warming.Larger species with shorter leaves(e.g.M.sativa)had higher photosynthetic rates under warming compared to smaller species with larger leaves(e.g.F.ovina).Our results highlight the importance of(i)studying photosynthetic responses along different years and(ii)considering functional traits when evaluating photosynthetic responses to climate change,particularly in stressful environments such as drylands.

The role of soluble sugars during drought in tropical tree seedlings with contrasting tolerances

非结构碳水化合物(NSCs)是植物的贮藏化合物,用于代谢、运输、渗透调节和叶片脱落后的再生。即使在最适宜生长的条件下,植物也会继续储存NSCs。这种储存可能是由于生长受到抑制而产生的被动积累,也可能是由于以生长为代价而产生的主动储备。前者暗示NSCs可能是碳汇有限生长的副产物,而后者则表明NSCs在植物适应逆境中具有的功能作用。本研究中,利用13C脉冲标记,我们追踪了具有不同干旱耐受性的两种热带树种的幼苗在干旱和常湿条件下茎和根器官中可溶性糖的来源,以估计干旱前储存的NSCs与干旱期间同化的NSCs的相对分配。我们监测了生长、气孔导度、茎干水势和NSC储存以评估对干旱的全碳响应。结果表明,与对照幼苗相比,不耐旱树种生长速度减慢,在叶片、茎和根器官中储存NSCs,在茎和根器官中可溶性糖(源于干旱前的储存)的比例更大。相反,与对照幼苗相比,耐旱树种则能保持生长和茎根NSCs浓度,但叶片NSCs浓度降低,茎和根可溶性糖的比例更大,这些可溶性糖来自于新同化的光合产物。这些结果表明,不耐旱树种由于缺水导致生长受限而被动积累NSCs,而耐旱树种则通过分配NSCs到茎和根器官来积极响应缺水。这些策略似乎与基线最大生长速率相关,并且支持了以前的研究结果,表明在生长和耐旱性之间存在一种权衡关系,同时也为NSCs分配的可塑性在干旱中的重要性提供了新的证据。

Convergence in leaf phenology traits of two understorey ferns in the northwestern Iberian Peninsula

Aims Plants control leaf phenology to maximize annual photosynthetic product.Although ferns play an important ecological role in many habitats,especially forests,their phenology traits have been poorly studied.Here,we investigate the leaf phenology of two ferns of the forest understorey and analyse the relationship between the timing of leaf emergence and spore dispersal and the effect of between-year climatic variation.Methods We compared the leafing and sporing phenologies of two ferns with very large(>2 m),overwintering leaves:Culcita macrocarpa and Woodwardia radicans.We regularly monitored individuals of six popu-lations in the northwestern Iberian Peninsula during a 3-year study.We studied eight phenology variables:leafing start date,leafing end date,leaf expansion time,number of new leaves per individual,between-individual synchrony,within-individual synchrony,percentage of fertile leaves and spore release date.We also determined leaf mass per area(LMA)and gathered data on air temperature and humidity.Important findings Both C.macrocarpa and W.radicans produce few leaves(~2 leaves individual−1 year−1),which expand simultaneously for a very long period(from midwinter to early summer),are retained for more than 1 year(37 and 19 months,respectively)and have relatively high LMAs.Such traits,together with large leaf size,have also been found in seed plants from the forest understorey and represent adap-tations to this light-limited environment.Spores of both study ferns are simultaneously released in late winter,with little between-year variation caused by differences in air humidity.This remarkable similarity between species suggests that the convergence in tim-ing of leaf emergence favours the convergence in timing of spore dispersal.