This work is a review of previous works,presenting and discussing the most important results obtained by an ongoing research program towards the development of innovative,low-cost,self-lubricating composites with a lo...This work is a review of previous works,presenting and discussing the most important results obtained by an ongoing research program towards the development of innovative,low-cost,self-lubricating composites with a low friction coefficient and high mechanical strength and wear resistance.Special emphasis is given to uniaxial die pressing of solid lubricant particles mixed with matrix powders and to metal injection moulding associated with in situ generation of solid lubricant particles.Initially,a microstructural model/processing route (powder injection moulding followed by plasma-assisted debinding and sintering) produced a homogeneous dispersion of in situ generated solid lubricant particles.Micrometric nodules of graphite with diameter smaller than 20 μm were formed,constituting a nanostructured stacking of graphite foils with nanometric thickness.Micro Raman analysis indicated that the graphite nodules were composed of turbostratic 2D graphite having highly misaligned graphene planes separated by large interlamellae distance.Large interplanar distance between the graphene foils and misalignment of these foils were confirmed by transmission electron microscopy and were,probably,the origin of the outstandingly low dry friction coefficient (0.04).The effect of sintering temperature,precursor content,metallic matrix composition and surface finish is also reported.Furthermore,the influence of a double-pressing/double-sintering (DPDS) technique on the tribological performance of self-lubricating uniaxially die-pressed hBN + graphite-Fe-Si-C-Mo composite is also investigated.Moreover,the tribological behaviour of die-pressed Fe-Si-C matrix composites containing 5,7.5 and 10 wt％ solid lubricants (hBN and graphite) added during the mixing step is analysed in terms of mechanical properties and wear mechanisms.Finally,the synergy between solid lubricant particles dispersed in a metallic matrix and fluid lubricants in a cooperative mixed lubrication regime is presented.展开更多
Carbon-based solid lubricants are excellent options to reduce friction and wear,especially with the carbon capability to adopt different allotropes forms.On the macroscale,these materials are sheared on the contact al...Carbon-based solid lubricants are excellent options to reduce friction and wear,especially with the carbon capability to adopt different allotropes forms.On the macroscale,these materials are sheared on the contact along with debris and contaminants to form tribolayers that govern the tribosystem performance.Using a recently developed advanced Raman analysis on the tribolayers,it was possible to quantify the contactinduced defects in the crystalline structure of a wide range of allotropes of carbon-based solid lubricants,from graphite and carbide-derived carbon particles to multi-layer graphene and carbon nanotubes.In addition,these materials were tested under various dry sliding conditions,with different geometries,topographies,and solid-lubricant application strategies.Regardless of the initial tribosystem conditions and allotrope level of atomic ordering,there is a remarkable trend of increasing the point and line defects density until a specific saturation limit in the same order of magnitude for all the materials tested.展开更多
Background: Understanding the role of species identity in interactions among individuals is crucial for assessing the productivity and stability of mixed forests over time. However, there is limited knowledge concerni...Background: Understanding the role of species identity in interactions among individuals is crucial for assessing the productivity and stability of mixed forests over time. However, there is limited knowledge concerning the variation in competitive effect and response of different species along climatic gradients. In this study, we investigated the importance of climate, tree size, and competition on the growth of three tree species: spruce(Picea abies), fir(Abies alba), and beech(Fagus sylvatica), and examined their competitive response and effect along a climatic gradient.Methods: We selected 39 plots distributed across the European mountains with records of the position and growth of 5,759 individuals. For each target species, models relating tree growth to tree size, climate and competition were proposed. Competition was modelled using a neighbourhood competition index that considered the effects of inter-and intraspecific competition on target trees. Competitive responses and effects were related to climate.Likelihood methods and information theory were used to select the best model.Results: Our findings revealed that competition had a greater impact on target species growth than tree size or climate. Climate did influence the competitive effects of neighbouring species, but it did not affect the target species? response to competition. The strength of competitive effects varied along the gradient, contingent on the identity of the interacting species. When the target species exhibited an intermediate competitive effect relative to neighbouring species, both higher inter-than intraspecific competitive effects and competition reduction occurred along the gradient. Notably, species competitive effects were most pronounced when the target species' growth was at its peak and weakest when growing conditions were far from their maximum.Conclusions: Climate modulates the effects of competition from neighbouring trees on the target tree and not the susceptibility of the target tree to competition. The modelling appr展开更多
Predicting plant development,a longstanding goal in plant physiology,involves 2 interwoven components:continuous growth and the progression of growth stages(phenology).Current models for winter wheat and soybean assum...Predicting plant development,a longstanding goal in plant physiology,involves 2 interwoven components:continuous growth and the progression of growth stages(phenology).Current models for winter wheat and soybean assume species-level growth responses to temperature.We challenge this assumption,suggesting that cultivar-specific temperature responses substantially affect phenology.To investigate,we collected field-based growth and phenology data in winter wheat and soybean over multiple years.We used diverse models,from linear to neural networks,to assess growth responses to temperature at various trait and covariate levels.Cultivar-specific nonlinear models best explained phenology-related cultivar-environment interactions.With cultivar-specific models,additional relations to other stressors than temperature were found.The availability of the presented field phenotyping tools allows incorporating cultivar-specific temperature response functions in future plant physiology studies,which will deepen our understanding of key factors that influence plant development.Consequently,this work has implications for crop breeding and cultivation under adverse climatic conditions.展开更多
We performed systematic laser spectroscopic investigations of La I spectral lines, using optogalvanic detection. Sixteen previously unknown even parity levels, having energies between 40,300 and 44,300 cm<sup>-1...We performed systematic laser spectroscopic investigations of La I spectral lines, using optogalvanic detection. Sixteen previously unknown even parity levels, having energies between 40,300 and 44,300 cm<sup>-1</sup>, are reported. These levels classify altogether 67 lines, not listed in spectral tables. The new levels were found due to the observation of the depopulation of the lower levels of the excited transitions. We found a remarkable variation of the observed widths of single hyperfine structure components dependent on the energy of the upper excited levels. Some levels having energies higher than 43,000 cm<sup>-1</sup> appear to have a very high ionization probability.展开更多
The influence of intrinsic defects of 1T-TaS_(2)on charge density waves(CDWs)is studied using scanning tunneling microscopy and spectroscopy(STM,STS),angle-resolved photoelectron spectroscopy(ARPES),and density functi...The influence of intrinsic defects of 1T-TaS_(2)on charge density waves(CDWs)is studied using scanning tunneling microscopy and spectroscopy(STM,STS),angle-resolved photoelectron spectroscopy(ARPES),and density functional theory(DFT).We identify several types of structural defects and find that most have a local character limited to a single CDW site,with a single exception which effectively behaves as a dopant,leading to band-bending and affecting multiple neighboring sites.While only one type of defect can be observed by STM topographic imaging,all defects are easily resolved in STS mapping.Our results indicate modulation of the Mott band gap commensurate with the CDW and breaking of the three-fold symmetry of electronic states.DFT calculations(with included Coulomb interactions)are used to investigate the electronic structure,focusing on both sulfur vacancy and oxygen-sulfur substitution.The sulfur vacancy system,characterized with a metallic behavior,is identified as the origin of one of the experimentally observed defects.Additionally,the effect of oxidation of 1T-TaS_(2)depends on the substitution site,leading to the heterogeneity of electronic properties.展开更多
Ethylene regulates many aspects of plant growth and development.It is perceived by a family of ethylene receptors(ETRs)that have been well described.However,a full understanding of ETR function is complicated by funct...Ethylene regulates many aspects of plant growth and development.It is perceived by a family of ethylene receptors(ETRs)that have been well described.However,a full understanding of ETR function is complicated by functional redundancy between the receptor isoforms.Here,we characterize a new ETR,SlETR7,that was revealed by tomato genome sequencing.SlETR7 expression in tomato fruit pericarp increases when the fruit ripens and its expression is synchronized with the expression of SlETR1,SlETR2,and SlETR5 which occurs later in the ripening phase than the increase observed for SlETR3,SlETR4,and SlETR6.We uncovered an error in the SlETR7 sequence as documented in the ITAG 3 versions of the tomato genome which has now been corrected in ITAG 4,and we showed that it belongs to sub-family II.We also showed that SlETR7 specifically binds ethylene.Overexpression(OE)of SlETR7 resulted in earlier flowering,shorter plants,and smaller fruit than wild type.Knock-out(KO)mutants of SlETR7 produced more ethylene at breaker(Br)and Br+2 days stages compared to wild type(WT),but there were no other obvious changes in the plant and fruit in these mutant lines.We observed that expression of the other SlETRs is upregulated in fruit of SlETR7 KO mutants,which may explain the absence of obvious ripening phenotypes.Globally,these results show that SlETR7 is a functional ethylene receptor.More work is needed to better understand its specific roles related to the six other tomato ETRs.展开更多
Molecular phylogenies using 1–4 gene regions and information on ecology,morphology and pigment chemistry were used in a partial revision of the agaric family Hygrophoraceae.The phylogenetically supported genera we re...Molecular phylogenies using 1–4 gene regions and information on ecology,morphology and pigment chemistry were used in a partial revision of the agaric family Hygrophoraceae.The phylogenetically supported genera we recognize here in the Hygrophoraceae based on these and previous analyses are:Acantholichen,Ampulloclitocybe,Arrhenia,Cantharellula,Cantharocybe,Chromosera,Chrysomphalina,Cora,Corella,Cuphophyllus,Cyphellostereum,Dictyonema,Eonema,Gliophorus,Haasiella,Humidicutis,Hygroaster,Hygrocybe,Hygrophorus,Lichenomphalia,Neohygrocybe,Porpolomopsis and Pseudoarmillariella.A new genus that is sister to Chromosera is described as Gloioxanthomyces.Revisions were made at the ranks of subfamily,tribe,genus,subgenus,section and subsection.We present three new subfamilies,eight tribes(five new),eight subgenera(one new,one new combination and one stat.nov.),26 sections(five new and three new combinations and two stat.nov.)and 14 subsections(two new,two stat.nov.).Species of Chromosera,Gliophorus,Humidicutis,and Neohygrocybe are often treated within the genus Hygrocybe;we therefore provide valid names in both classification systems.We used a minimalist approach in transferring genera and creating new names and combinations.Consequently,we retain in the Hygrophoraceae the basal cuphophylloid grade comprising the genera Cuphophyllus,Ampulloclitocybe andCantharocybe,despite weak phylogenetic support.We include Aeruginospora and Semiomphalina in Hygrophoraceae based on morphology though molecular data are lacking.The lower hygrophoroid clade is basal to Hygrophoraceae s.s.,comprising the genera Aphroditeola,Macrotyphula,Phyllotopsis,Pleurocybella,Sarcomyxa,Tricholomopsis and Typhula.展开更多
The phylogeny of Phylloporus(Boletaceae)has not been well studied,and the taxonomic relationships of this genus have varied considerably among authors.The following study presents phylogenetic relationships of Phyllop...The phylogeny of Phylloporus(Boletaceae)has not been well studied,and the taxonomic relationships of this genus have varied considerably among authors.The following study presents phylogenetic relationships of Phylloporus based on two nuclear ribosomal DNA regions,ITS and LSU.The ITS dataset includes 39 collections and the LSU dataset contains 50 collections of Phylloporus.A combined analysis of both genes did not resolve the deeper nodes in the phylogeny,but the results suggest that Phylloporus is monophyletic and a sister group of the Xerocomus subtomentosus group.The lamellate hymenophore configuration is a synapomorphy that distinguishes Phylloporus from the other genera in the family.The placement of a lamellate genus within Boletaceae suggests that hymenophore evolution is not well understood in the family.This is the first phylogeny of Phylloporus and includes 20 species from different geographic regions.Six taxa of Phylloporus from the Old World are here presented.Phylloporus cyanescens is a new combination for an Australasian taxon formerly named as a variety of P.bellus(Massee)Corner.Phylloporus pumilus is described from Indonesia,and 4 species are described from Thailand:P.castanopsidis,P.dimorphus,P.infuscatus,and P.rubiginosus.展开更多
BACKGROUND In a previous paper,we reported a high prevalence of donor-specific antibody(DSA)in pediatric patients with chronic rejection and expressed the need for confirmation of these findings in a larger cohort.AIM...BACKGROUND In a previous paper,we reported a high prevalence of donor-specific antibody(DSA)in pediatric patients with chronic rejection and expressed the need for confirmation of these findings in a larger cohort.AIM To clarify the importance of DSAs on long-term graft survival in a larger cohort of pediatric patients.METHODS We performed a retrospective analysis of 123 pediatric liver transplantation(LT)recipients who participated in yearly follow-ups including Luminex testing for DSA at our center.The cohort was split into two groups according to the DSA status(DSA-positive n=54,DSA-negative n=69).Groups were compared with regard to liver function,biopsy findings,graft survival,need for re-LT and immunosuppressive medication.RESULTS DSA-positive pediatric patients showed a higher prevalence of chronic rejection(P=0.01),fibrosis(P<0.001)and re-transplantation(P=0.018)than DSA-negative patients.Class II DSAs particularly influenced graft survival.Alleles DQ2,DQ7,DQ8 and DQ9 might serve as indicators for the risk of chronic rejection and/or allograft fibrosis.Mean fluorescence intensity levels and DSA number did not impact graft survival.Previous episodes of chronic rejection might lead to DSA development.CONCLUSION DSA prevalence significantly affected long-term liver allograft performance and liver allograft survival in our cohort of pediatric LT.Screening for class II DSAs in combination with assessment of protocol liver biopsies for chronic antibodymediated rejection improved early identification of patients at risk of graft loss.展开更多
Background:Obesity and associated steatosis is an increasing health problem worldwide.Its influence on post-hepatectomy liver failure(PHLF)and after liver resection(LR)is still unclear.Methods:Patients who underwent L...Background:Obesity and associated steatosis is an increasing health problem worldwide.Its influence on post-hepatectomy liver failure(PHLF)and after liver resection(LR)is still unclear.Methods:Patients who underwent LR were investigated and divided into three groups[normal weight:body mass index(BMI)18.5-24.9 kg/m2,overweight:BMI 25.0-29.9 kg/m2,obese:BMI≥30 kg/m2]in this retrospective study.Primary aim of this study was to assess the influence of BMI and nonalcoholic steatohepatitis(NASH)on PHLF and morbidity.Results:Of 888 included patients,361(40.7%)had normal weight,360(40.5%)were overweight,167(18.8%)were obese.Median age was 62.5 years(IQR,54-69 years).The primary indication for LR was colorectal liver metastases(CLM)(n=366,41.2%).NASH was present in 58(16.1%)of normal weight,84(23.3%)of overweight and 69(41.3%)of obese patients(P<0.001).PHLF occurred in 16.3%in normal weight,15.3%in overweight and 11.4%in obese patients(P=0.32).NASH was not associated with PHLF.There was no association between patients’weight and the occurrence of postoperative complications(P=0.45).At multivariable analysis,solely major LR[odds ratio(OR):2.7,95%confidence interval(CI):1.83-4.04;P<0.001]remained a significant predictor for PHLF.Conclusions:Postoperative complications and PHLF are comparable in normal weight,overweight and obese patients and LRs using modern techniques can be safely performed in these patients.展开更多
Although the deposition mechanisms of the cold spray process are well studied, few reports regarding the use of surface-modified particles exist. Herein, titanium particles 3-39 μm in size and with an angular shape w...Although the deposition mechanisms of the cold spray process are well studied, few reports regarding the use of surface-modified particles exist. Herein, titanium particles 3-39 μm in size and with an angular shape were modified in a plasma-enhanced chemical vapor deposition process in Ar, Ar-C2H2, and N2 plasmas. After Ar-C2H2 and N2 treatments, the respective presence of TiC and TiN on the particle surface was confirmed via transmission electron microscopy and energy-dispersive X-ray, X-ray photoelectron, and Raman spectroscopies. The powders were deposited on titanium substrates by cold spray experiments, where unmodified particles up to 10(xm in size exhibited a successful surface bon ding. This finding was described by an existing analytical model, whose parameters were achieved by computational fluid dynamics simulations taking the particle shape factor into account:. A good deposition of plasma-modified particles up to 30 μm in size was experimentally observed, exhibiting an upper size limit larger than that predicted by the model. Higher surface roughness values were found for plasmamodified particles, as determined by 3D scanning electron microscopy. The water contact angle indicated that argon treatment influenced the wettability. Tribological tests showed a decrease of the initial friction coefficient from 0.53 to 0.47 by microstructuring.展开更多
The influence of 40 kHz ultrasound radiation on the passivation behavior of zinc in 7 M KOH is presented. The results of potentiodynamic and potentiostatic measurements combined with the current oscillation caused by ...The influence of 40 kHz ultrasound radiation on the passivation behavior of zinc in 7 M KOH is presented. The results of potentiodynamic and potentiostatic measurements combined with the current oscillation caused by the irradiation were examined to explain the mechanism and the sequence of formation of the oxide films during passivation. In this study, sonication was also used to investigate both effects of the passivation duration and passivation potential on the structure of the oxide layers; the adherence of the layers was found to depend strongly on both parameters. Scanning electron microscopy-energy dispersive X-ray （SEM-EDX） analysis of the zinc surface provided complementary information on the oxide layer composition and structure.展开更多
DC plasma is a very promising technology for processing different materials, and is becoming especially interesting when low environmental impact and high-performance treatments are needed. Some of the intrinsic chara...DC plasma is a very promising technology for processing different materials, and is becoming especially interesting when low environmental impact and high-performance treatments are needed. Some of the intrinsic characteristics of DC plasma technology, which make it suitable for powder metallurgy （PM） and powder injection molding （PIM） parts production, are low- pressure processing and plasma environment high reactivity. Moreover it can be considered as a highly competitive green technology. In this work, an overview of some of the important DC plasma techniques applied to PM and PIM parts processing is presented. Emphasis is given to the descriptions of the main characteristics and the technique potentials of plasma-assisted nitriding, plasma-assisted thermal debinding, plasma-assisted sintering, and simultaneously plasma-assisted sintering and surface alloying. The aspects presented and discussed in this paper indicate that DC plasma processes are promising and competitive techniques for PM and PIM parts processing.展开更多
The methods and strategies used to screen for syp-hilis and to confirm initially reactive results can vary significantly across clinical laboratories. While the performance characteristics of these different appro-ach...The methods and strategies used to screen for syp-hilis and to confirm initially reactive results can vary significantly across clinical laboratories. While the performance characteristics of these different appro-aches have been evaluated by multiple studies, there is not, as of yet, a single, universally recommendedalgorithm for syphilis testing. To clarify the currently available options for syphilis testing, this update will summarize the clinical challenges to diagnosis, review the specific performance characteristics of treponemal and non-treponemal tests, and fnally, summarize select studies published over the past decade which have evaluated these approaches. Specifcally, this review will discuss the traditional and reverse sequence syphilis screening algorithms commonly used in the United States, alongside a discussion of the European Centre for Disease Prevention and Control syphilis algorithm. Ultimately, in the United States, the decision of which algorithm to use is largely dependent on laboratory resources, the local incidence of syphilis and patient demographics. Key words： Syphilis; Treponemal infection; Immuno-assay; Reverse sequence screening; Rapid plasma regain; Treponema pallidum particle agglutination test; Automation; Algorithm; Primary infection; Late latent infection展开更多
From 2009 until 2012 the project“Watershed Management of Forest Land in Beijing,Restoration of Small Water Bodies(SWBR)”was implemented,combining Close to Nature Forest Management and Restoration of Small Water Bodi...From 2009 until 2012 the project“Watershed Management of Forest Land in Beijing,Restoration of Small Water Bodies(SWBR)”was implemented,combining Close to Nature Forest Management and Restoration of Small Water Bodies.The targets were to improve flood control,to enhance the ecological conditions by copying nature and to support the recreational value of small water bodies,all in cooperation with people living there.The efficiency of each project was proofed by comparison of biological and hydro-morphological assessment before the projects started and 2-3 years after they were finished.The results confirmed the ecological improvements of the restored river sections and showed the achievements.Guidelines to assess the biological and hydro-morphological status of rivers were developed and there are plans to introduce them as Beijing Standards.Planning and implementation of measures,based on experiences in Central Europe,will be documented in a handbook.&2015 International Research and Training Center on Erosion and Sedimentation and China Water and Power Press.Production and Hosting by Elsevier B.V.This is an open access article under the CC BY-NC-ND license(http://creativecommons.org/licenses/by-nc-nd/4.0/).展开更多
文摘This work is a review of previous works,presenting and discussing the most important results obtained by an ongoing research program towards the development of innovative,low-cost,self-lubricating composites with a low friction coefficient and high mechanical strength and wear resistance.Special emphasis is given to uniaxial die pressing of solid lubricant particles mixed with matrix powders and to metal injection moulding associated with in situ generation of solid lubricant particles.Initially,a microstructural model/processing route (powder injection moulding followed by plasma-assisted debinding and sintering) produced a homogeneous dispersion of in situ generated solid lubricant particles.Micrometric nodules of graphite with diameter smaller than 20 μm were formed,constituting a nanostructured stacking of graphite foils with nanometric thickness.Micro Raman analysis indicated that the graphite nodules were composed of turbostratic 2D graphite having highly misaligned graphene planes separated by large interlamellae distance.Large interplanar distance between the graphene foils and misalignment of these foils were confirmed by transmission electron microscopy and were,probably,the origin of the outstandingly low dry friction coefficient (0.04).The effect of sintering temperature,precursor content,metallic matrix composition and surface finish is also reported.Furthermore,the influence of a double-pressing/double-sintering (DPDS) technique on the tribological performance of self-lubricating uniaxially die-pressed hBN + graphite-Fe-Si-C-Mo composite is also investigated.Moreover,the tribological behaviour of die-pressed Fe-Si-C matrix composites containing 5,7.5 and 10 wt％ solid lubricants (hBN and graphite) added during the mixing step is analysed in terms of mechanical properties and wear mechanisms.Finally,the synergy between solid lubricant particles dispersed in a metallic matrix and fluid lubricants in a cooperative mixed lubrication regime is presented.
基金the following Brazilian agencies for funding this research:CNPq,CAPES,BNDES and the Chilean agency ANID Vinculación Internacional FOVI220096(No.72190023)as well as Nidec Global Appliance/Embraco.
文摘Carbon-based solid lubricants are excellent options to reduce friction and wear,especially with the carbon capability to adopt different allotropes forms.On the macroscale,these materials are sheared on the contact along with debris and contaminants to form tribolayers that govern the tribosystem performance.Using a recently developed advanced Raman analysis on the tribolayers,it was possible to quantify the contactinduced defects in the crystalline structure of a wide range of allotropes of carbon-based solid lubricants,from graphite and carbide-derived carbon particles to multi-layer graphene and carbon nanotubes.In addition,these materials were tested under various dry sliding conditions,with different geometries,topographies,and solid-lubricant application strategies.Regardless of the initial tribosystem conditions and allotrope level of atomic ordering,there is a remarkable trend of increasing the point and line defects density until a specific saturation limit in the same order of magnitude for all the materials tested.
基金This publication is based upon work from COST Action CLIMO(CA15226) supported by COST (European Cooperation in Science and Technology)the UMBRACLIM project (PID2019-111781RB-I00)funded by the Spanish Ministry for Science and Innovation. Teresa Valor was contracted with a grant“Juan de la Cierva-Formaci on”(FJC2018-036673-I). Z.S. received funds from the grant no. APVV-20-0365 and from project TreeAdapt supported by the MPRV SR. Aitor Ameztegui is supported by a Serra-Húnter fellowship by the Generalitat de Catalunya。
文摘Background: Understanding the role of species identity in interactions among individuals is crucial for assessing the productivity and stability of mixed forests over time. However, there is limited knowledge concerning the variation in competitive effect and response of different species along climatic gradients. In this study, we investigated the importance of climate, tree size, and competition on the growth of three tree species: spruce(Picea abies), fir(Abies alba), and beech(Fagus sylvatica), and examined their competitive response and effect along a climatic gradient.Methods: We selected 39 plots distributed across the European mountains with records of the position and growth of 5,759 individuals. For each target species, models relating tree growth to tree size, climate and competition were proposed. Competition was modelled using a neighbourhood competition index that considered the effects of inter-and intraspecific competition on target trees. Competitive responses and effects were related to climate.Likelihood methods and information theory were used to select the best model.Results: Our findings revealed that competition had a greater impact on target species growth than tree size or climate. Climate did influence the competitive effects of neighbouring species, but it did not affect the target species? response to competition. The strength of competitive effects varied along the gradient, contingent on the identity of the interacting species. When the target species exhibited an intermediate competitive effect relative to neighbouring species, both higher inter-than intraspecific competitive effects and competition reduction occurred along the gradient. Notably, species competitive effects were most pronounced when the target species' growth was at its peak and weakest when growing conditions were far from their maximum.Conclusions: Climate modulates the effects of competition from neighbouring trees on the target tree and not the susceptibility of the target tree to competition. The modelling appr
基金support for the research of this work from the Swiss National Science Foundation(grant numbers 169542 and 200756)S.Y.discloses support for the research of this work from the Swiss National Science Foundation(grant number 138983)L.R.discloses support for the research of this work from the Swiss Data Science Center(grant number PHENO-MINE C21-04).
文摘Predicting plant development,a longstanding goal in plant physiology,involves 2 interwoven components:continuous growth and the progression of growth stages(phenology).Current models for winter wheat and soybean assume species-level growth responses to temperature.We challenge this assumption,suggesting that cultivar-specific temperature responses substantially affect phenology.To investigate,we collected field-based growth and phenology data in winter wheat and soybean over multiple years.We used diverse models,from linear to neural networks,to assess growth responses to temperature at various trait and covariate levels.Cultivar-specific nonlinear models best explained phenology-related cultivar-environment interactions.With cultivar-specific models,additional relations to other stressors than temperature were found.The availability of the presented field phenotyping tools allows incorporating cultivar-specific temperature response functions in future plant physiology studies,which will deepen our understanding of key factors that influence plant development.Consequently,this work has implications for crop breeding and cultivation under adverse climatic conditions.
文摘We performed systematic laser spectroscopic investigations of La I spectral lines, using optogalvanic detection. Sixteen previously unknown even parity levels, having energies between 40,300 and 44,300 cm<sup>-1</sup>, are reported. These levels classify altogether 67 lines, not listed in spectral tables. The new levels were found due to the observation of the depopulation of the lower levels of the excited transitions. We found a remarkable variation of the observed widths of single hyperfine structure components dependent on the energy of the upper excited levels. Some levels having energies higher than 43,000 cm<sup>-1</sup> appear to have a very high ionization probability.
基金supported by the National Science Centre,Poland under grants 2015/19/B/ST3/03142 and 2019/32/T/ST3/00487M.L.S.thanks for University of Lodz support under IDUB 6/JRR/2021 project.T.-C.C acknowledges support of the U.S.Department of Energy,Office of Science,Office of Basic Energy Sciences,Division of Materials Science and Engineering,under Grant No.DE-FG02-07ER46383+4 种基金M.G.acknowledges financial support provided by Slovak Research and Development Agency provided under Contract No.APVV-SKCZ-RD-21-0114by the Ministry of Education,Science,Research and Sport of the Slovak Republic provided under Grant No.VEGA 1/0105/20Slovak Academy of Sciences project IMPULZ IM-2021-42project FLAG ERA JTC 20212DSOTECHAuthor acknowledges the provision of the Polish Ministry of Education and Science project(Support for research and development with the use of research infrastructure of the National Synchrotron Radiation Centre SOLARIS”under contract nr 1/SOL/2021/2).
文摘The influence of intrinsic defects of 1T-TaS_(2)on charge density waves(CDWs)is studied using scanning tunneling microscopy and spectroscopy(STM,STS),angle-resolved photoelectron spectroscopy(ARPES),and density functional theory(DFT).We identify several types of structural defects and find that most have a local character limited to a single CDW site,with a single exception which effectively behaves as a dopant,leading to band-bending and affecting multiple neighboring sites.While only one type of defect can be observed by STM topographic imaging,all defects are easily resolved in STS mapping.Our results indicate modulation of the Mott band gap commensurate with the CDW and breaking of the three-fold symmetry of electronic states.DFT calculations(with included Coulomb interactions)are used to investigate the electronic structure,focusing on both sulfur vacancy and oxygen-sulfur substitution.The sulfur vacancy system,characterized with a metallic behavior,is identified as the origin of one of the experimentally observed defects.Additionally,the effect of oxidation of 1T-TaS_(2)depends on the substitution site,leading to the heterogeneity of electronic properties.
文摘Ethylene regulates many aspects of plant growth and development.It is perceived by a family of ethylene receptors(ETRs)that have been well described.However,a full understanding of ETR function is complicated by functional redundancy between the receptor isoforms.Here,we characterize a new ETR,SlETR7,that was revealed by tomato genome sequencing.SlETR7 expression in tomato fruit pericarp increases when the fruit ripens and its expression is synchronized with the expression of SlETR1,SlETR2,and SlETR5 which occurs later in the ripening phase than the increase observed for SlETR3,SlETR4,and SlETR6.We uncovered an error in the SlETR7 sequence as documented in the ITAG 3 versions of the tomato genome which has now been corrected in ITAG 4,and we showed that it belongs to sub-family II.We also showed that SlETR7 specifically binds ethylene.Overexpression(OE)of SlETR7 resulted in earlier flowering,shorter plants,and smaller fruit than wild type.Knock-out(KO)mutants of SlETR7 produced more ethylene at breaker(Br)and Br+2 days stages compared to wild type(WT),but there were no other obvious changes in the plant and fruit in these mutant lines.We observed that expression of the other SlETRs is upregulated in fruit of SlETR7 KO mutants,which may explain the absence of obvious ripening phenotypes.Globally,these results show that SlETR7 is a functional ethylene receptor.More work is needed to better understand its specific roles related to the six other tomato ETRs.
基金This work was not directly supported by grants,but the following grants were essential in obtaining collections and some sequences used in this work:US NSF Biodiversity Surveys and Inventories Program grants to the Research Foundation of the State University of New York,College at Cortland(DEB-9525902 and DEB-0103621),in collaboration with the USDA-Forest Service,Center for Forest Mycology Research,Forest Products Laboratory in Madison supported collecting in Belize,the Dominican Republic and Puerto Rico.US NSF grant DBI 6338699 to K.W.Hughes and R.H.Peterson at the University of Tennessee,Knoxville supported collecting by E.Lickey,D.J.Lodge,K.W.Hughes,R.Kerrigan,A.Methven,V.P.Hustedt,P.B.Matheny and R.H.Petersen in the Great Smoky Mountain National Park,and sequencing by K.W.Hughes and Lickey.A National Geographic Society’s Committee for Research and Exploration grant to T.J.Baroni(SUNY Cortland)supported the 2007 expedition to Doyle’s Delight in Belize by M.C.Aime,T.J.Baroni and D.J.Lodge.An Explorer’s Club,Washington Group Exploration and Field Research Grant to M.C.Aime and a National Geographic Society’s Committee for Research and Exploration grant to T.Henkel supported collecting in Guyana.
文摘Molecular phylogenies using 1–4 gene regions and information on ecology,morphology and pigment chemistry were used in a partial revision of the agaric family Hygrophoraceae.The phylogenetically supported genera we recognize here in the Hygrophoraceae based on these and previous analyses are:Acantholichen,Ampulloclitocybe,Arrhenia,Cantharellula,Cantharocybe,Chromosera,Chrysomphalina,Cora,Corella,Cuphophyllus,Cyphellostereum,Dictyonema,Eonema,Gliophorus,Haasiella,Humidicutis,Hygroaster,Hygrocybe,Hygrophorus,Lichenomphalia,Neohygrocybe,Porpolomopsis and Pseudoarmillariella.A new genus that is sister to Chromosera is described as Gloioxanthomyces.Revisions were made at the ranks of subfamily,tribe,genus,subgenus,section and subsection.We present three new subfamilies,eight tribes(five new),eight subgenera(one new,one new combination and one stat.nov.),26 sections(five new and three new combinations and two stat.nov.)and 14 subsections(two new,two stat.nov.).Species of Chromosera,Gliophorus,Humidicutis,and Neohygrocybe are often treated within the genus Hygrocybe;we therefore provide valid names in both classification systems.We used a minimalist approach in transferring genera and creating new names and combinations.Consequently,we retain in the Hygrophoraceae the basal cuphophylloid grade comprising the genera Cuphophyllus,Ampulloclitocybe andCantharocybe,despite weak phylogenetic support.We include Aeruginospora and Semiomphalina in Hygrophoraceae based on morphology though molecular data are lacking.The lower hygrophoroid clade is basal to Hygrophoraceae s.s.,comprising the genera Aphroditeola,Macrotyphula,Phyllotopsis,Pleurocybella,Sarcomyxa,Tricholomopsis and Typhula.
基金The first author thanks Coordenação de Aperfeiçoamento de Pessoal de Nível Superior(CAPES,Brasil)for the financial support during her PhDThe authors are grateful to the National Science Foundation for partial support from grants BSR-8600424,DEB-9300798,DEB-9972018,and DEB-0414665 awarded to Roy Halling,as well as DEB-0444531 awarded to Manfred Binder and David Hibbett.Thanks to the Mushroom Research Centre in Chiang Mai(Thailand)and Dennis Desjardin(San Francisco State University)for a fieldwork opportunity.
文摘The phylogeny of Phylloporus(Boletaceae)has not been well studied,and the taxonomic relationships of this genus have varied considerably among authors.The following study presents phylogenetic relationships of Phylloporus based on two nuclear ribosomal DNA regions,ITS and LSU.The ITS dataset includes 39 collections and the LSU dataset contains 50 collections of Phylloporus.A combined analysis of both genes did not resolve the deeper nodes in the phylogeny,but the results suggest that Phylloporus is monophyletic and a sister group of the Xerocomus subtomentosus group.The lamellate hymenophore configuration is a synapomorphy that distinguishes Phylloporus from the other genera in the family.The placement of a lamellate genus within Boletaceae suggests that hymenophore evolution is not well understood in the family.This is the first phylogeny of Phylloporus and includes 20 species from different geographic regions.Six taxa of Phylloporus from the Old World are here presented.Phylloporus cyanescens is a new combination for an Australasian taxon formerly named as a variety of P.bellus(Massee)Corner.Phylloporus pumilus is described from Indonesia,and 4 species are described from Thailand:P.castanopsidis,P.dimorphus,P.infuscatus,and P.rubiginosus.
文摘BACKGROUND In a previous paper,we reported a high prevalence of donor-specific antibody(DSA)in pediatric patients with chronic rejection and expressed the need for confirmation of these findings in a larger cohort.AIM To clarify the importance of DSAs on long-term graft survival in a larger cohort of pediatric patients.METHODS We performed a retrospective analysis of 123 pediatric liver transplantation(LT)recipients who participated in yearly follow-ups including Luminex testing for DSA at our center.The cohort was split into two groups according to the DSA status(DSA-positive n=54,DSA-negative n=69).Groups were compared with regard to liver function,biopsy findings,graft survival,need for re-LT and immunosuppressive medication.RESULTS DSA-positive pediatric patients showed a higher prevalence of chronic rejection(P=0.01),fibrosis(P<0.001)and re-transplantation(P=0.018)than DSA-negative patients.Class II DSAs particularly influenced graft survival.Alleles DQ2,DQ7,DQ8 and DQ9 might serve as indicators for the risk of chronic rejection and/or allograft fibrosis.Mean fluorescence intensity levels and DSA number did not impact graft survival.Previous episodes of chronic rejection might lead to DSA development.CONCLUSION DSA prevalence significantly affected long-term liver allograft performance and liver allograft survival in our cohort of pediatric LT.Screening for class II DSAs in combination with assessment of protocol liver biopsies for chronic antibodymediated rejection improved early identification of patients at risk of graft loss.
文摘Background:Obesity and associated steatosis is an increasing health problem worldwide.Its influence on post-hepatectomy liver failure(PHLF)and after liver resection(LR)is still unclear.Methods:Patients who underwent LR were investigated and divided into three groups[normal weight:body mass index(BMI)18.5-24.9 kg/m2,overweight:BMI 25.0-29.9 kg/m2,obese:BMI≥30 kg/m2]in this retrospective study.Primary aim of this study was to assess the influence of BMI and nonalcoholic steatohepatitis(NASH)on PHLF and morbidity.Results:Of 888 included patients,361(40.7%)had normal weight,360(40.5%)were overweight,167(18.8%)were obese.Median age was 62.5 years(IQR,54-69 years).The primary indication for LR was colorectal liver metastases(CLM)(n=366,41.2%).NASH was present in 58(16.1%)of normal weight,84(23.3%)of overweight and 69(41.3%)of obese patients(P<0.001).PHLF occurred in 16.3%in normal weight,15.3%in overweight and 11.4%in obese patients(P=0.32).NASH was not associated with PHLF.There was no association between patients’weight and the occurrence of postoperative complications(P=0.45).At multivariable analysis,solely major LR[odds ratio(OR):2.7,95%confidence interval(CI):1.83-4.04;P<0.001]remained a significant predictor for PHLF.Conclusions:Postoperative complications and PHLF are comparable in normal weight,overweight and obese patients and LRs using modern techniques can be safely performed in these patients.
文摘Although the deposition mechanisms of the cold spray process are well studied, few reports regarding the use of surface-modified particles exist. Herein, titanium particles 3-39 μm in size and with an angular shape were modified in a plasma-enhanced chemical vapor deposition process in Ar, Ar-C2H2, and N2 plasmas. After Ar-C2H2 and N2 treatments, the respective presence of TiC and TiN on the particle surface was confirmed via transmission electron microscopy and energy-dispersive X-ray, X-ray photoelectron, and Raman spectroscopies. The powders were deposited on titanium substrates by cold spray experiments, where unmodified particles up to 10(xm in size exhibited a successful surface bon ding. This finding was described by an existing analytical model, whose parameters were achieved by computational fluid dynamics simulations taking the particle shape factor into account:. A good deposition of plasma-modified particles up to 30 μm in size was experimentally observed, exhibiting an upper size limit larger than that predicted by the model. Higher surface roughness values were found for plasmamodified particles, as determined by 3D scanning electron microscopy. The water contact angle indicated that argon treatment influenced the wettability. Tribological tests showed a decrease of the initial friction coefficient from 0.53 to 0.47 by microstructuring.
文摘The influence of 40 kHz ultrasound radiation on the passivation behavior of zinc in 7 M KOH is presented. The results of potentiodynamic and potentiostatic measurements combined with the current oscillation caused by the irradiation were examined to explain the mechanism and the sequence of formation of the oxide films during passivation. In this study, sonication was also used to investigate both effects of the passivation duration and passivation potential on the structure of the oxide layers; the adherence of the layers was found to depend strongly on both parameters. Scanning electron microscopy-energy dispersive X-ray （SEM-EDX） analysis of the zinc surface provided complementary information on the oxide layer composition and structure.
文摘DC plasma is a very promising technology for processing different materials, and is becoming especially interesting when low environmental impact and high-performance treatments are needed. Some of the intrinsic characteristics of DC plasma technology, which make it suitable for powder metallurgy （PM） and powder injection molding （PIM） parts production, are low- pressure processing and plasma environment high reactivity. Moreover it can be considered as a highly competitive green technology. In this work, an overview of some of the important DC plasma techniques applied to PM and PIM parts processing is presented. Emphasis is given to the descriptions of the main characteristics and the technique potentials of plasma-assisted nitriding, plasma-assisted thermal debinding, plasma-assisted sintering, and simultaneously plasma-assisted sintering and surface alloying. The aspects presented and discussed in this paper indicate that DC plasma processes are promising and competitive techniques for PM and PIM parts processing.
文摘The methods and strategies used to screen for syp-hilis and to confirm initially reactive results can vary significantly across clinical laboratories. While the performance characteristics of these different appro-aches have been evaluated by multiple studies, there is not, as of yet, a single, universally recommendedalgorithm for syphilis testing. To clarify the currently available options for syphilis testing, this update will summarize the clinical challenges to diagnosis, review the specific performance characteristics of treponemal and non-treponemal tests, and fnally, summarize select studies published over the past decade which have evaluated these approaches. Specifcally, this review will discuss the traditional and reverse sequence syphilis screening algorithms commonly used in the United States, alongside a discussion of the European Centre for Disease Prevention and Control syphilis algorithm. Ultimately, in the United States, the decision of which algorithm to use is largely dependent on laboratory resources, the local incidence of syphilis and patient demographics. Key words： Syphilis; Treponemal infection; Immuno-assay; Reverse sequence screening; Rapid plasma regain; Treponema pallidum particle agglutination test; Automation; Algorithm; Primary infection; Late latent infection
文摘From 2009 until 2012 the project“Watershed Management of Forest Land in Beijing,Restoration of Small Water Bodies(SWBR)”was implemented,combining Close to Nature Forest Management and Restoration of Small Water Bodies.The targets were to improve flood control,to enhance the ecological conditions by copying nature and to support the recreational value of small water bodies,all in cooperation with people living there.The efficiency of each project was proofed by comparison of biological and hydro-morphological assessment before the projects started and 2-3 years after they were finished.The results confirmed the ecological improvements of the restored river sections and showed the achievements.Guidelines to assess the biological and hydro-morphological status of rivers were developed and there are plans to introduce them as Beijing Standards.Planning and implementation of measures,based on experiences in Central Europe,will be documented in a handbook.&2015 International Research and Training Center on Erosion and Sedimentation and China Water and Power Press.Production and Hosting by Elsevier B.V.This is an open access article under the CC BY-NC-ND license(http://creativecommons.org/licenses/by-nc-nd/4.0/).
