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Phase diagram of a distorted kagome antiferromagnet and application to Y-kapellasite

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npj Computational Materials 2022年第1期8卷 79-88页

作者： Max Hering Francesco Ferrari Aleksandar Razpopov Igor I.Mazin Roser Valentí Harald O.Jeschke johannes Reuther Helmholtz-Zentrum Berlin für Materialien und Energie Hahn-Meitner Platz 114109BerlinGermany Dahlem Center for Complex Quantum Systems and Fachbereich Physik Freie Universität Berlin14195BerlinGermany Institute for Theoretical Physics Goethe University FrankfurtMax-von-Laue-Straße 160438Frankfurt am MainGermany Department of Physics and Astronomy and Quantum Science and Engineering CenterGeorge Mason UniversityFairfaxVA22030USA Research Institute for Interdisciplinary Science Okayama UniversityOkayama700-8530Japan

We investigate the magnetism of a previously unexplored distorted spin-1/2 kagome model consisting of three symmetry-inequivalent nearest-neighbor antiferromagnetic Heisenberg couplings J_(■),J,and J′,and uncover a rich ground state phase diagram even at the classical *** analytical arguments and numerical techniques we identify a collinear Q^(→)=0 magnetic phase,two unusual non-collinear coplanar Q^(→)=(1/3,1/3)phases and a classical spin liquid phase with a degenerate manifold of non-coplanar ground states,resembling the jammed spin liquid phase found in the context of a bond-disordered kagome *** further show with density functional theory calculations that the recently synthesized Y-kapellasite Y_(3)Cu_(9)(OH)_(19)C_(l8) is a realization of this model and predict its ground state to lie in the region of Q^(→)=(1/3,1/3)order,which remains stable even after the inclusion of quantum fluctuation effects within variational Monte Carlo and pseudofermion functional renormalization *** presented model opens a new direction in the study of kagome antiferromagnets.

关键词： group distorted diagram

Assessing the Storage Root Development of Cassava with a New Analysis Tool

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Plant Phenomics 2022年第1期4卷 43-57页

作者： Jens Wilhelm Tobias Wojciechowski johannes A.Postma Dirk Jollet Kathrin Heinz Vera Bockem Mark Muller-Linow Institute of Plant Sciences IBG-2Forschungszentrum Julich GmbH52425 JulichGermany Tesla Automation GmbH 54595 PrumGermany

Storage roots of cassava plants crops are one of the main providers of starch in many South American,African,and Asian *** varieties with high yields is crucial for growing and *** requires a better understanding of the dynamics of storage root formation,which is usually done by repeated manual evaluation of root types,diameters,and their distribution in excavated *** introduce a newly developed method that is capable to analyze the distribution of root diameters automatically,even if root systems display strong variations in root widths and clustering in high *** application study was conducted with cassava roots imaged in a video acquisition *** root diameter distribution was quantified automatically using an iterative ridge detection approach,which can cope with a wide span of root diameters and *** approach was validated with virtual root models of known geometries and then tested with a time-series of excavated root *** on the retrieved diameter classes,we show plausibly that the dynamics of root type formation can be monitored qualitatively and *** conclude that this new method reliably determines important phenotypic traits from storage root crop *** method is fast and robustly analyses complex root systems and thereby applicable in high-throughput phenotyping and future breeding.

关键词： crops roots Storage

How much resistance exercise is beneficial for healthy aging and longevity?

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Journal of Sport and Health Science 2023年第3期12卷 284-286页

作者： johannes Burtscher Barbara Strasser Giuseppe D'Antona Gregoire P.Millet Martin Burtscher Department of Biomedical Sciences University of LausanneLausanne 1015Switzerland Institute of Sport Sciences University of LausanneLausanne 1015Switzerland Medical Faculty Sigmund Freud Private UniversityVienna A-1020Austria CRIAMS-Sport Medicine Centre Voghera University of PaviaPavia I-27100Italy Department of Public Health Experimental and Forensic MedicineUniversity of PaviaPavia I-27100Italy Department of Sport Science University of InnsbruckInnsbruck A-6020Austria

Regular physical activity(PA)promotes healthy aging,and activities aiming to increase muscular strength(i.e.,resistance exercise(RE))are important PA modalities for achieving health *** meta-analyses demonstrated that both RE^(1) and muscular strength^(2) were associated with mortality benefits,even when RE was performed above the PA targets recommended by current guidelines^(1,3).

关键词： aging resistance strength

Is Hypoxic/Altitude Training an Important Topic in the Field of Hypoxia?

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Journal of Science in Sport and Exercise 2022年第4期4卷 293-305页

作者： Grégoire P.Millet Martin Burtscher johannes Burtscher Institute of Sport Sciences University of LausanneCampus Dorigny1015 LausanneSwitzerland Department of Biomedical Sciences University of Lausanne1015 LausanneSwitzerland Department of Sport Science University of InnsbruckInnsbruckAustria

Hypoxia is an essential topic in medical or biological *** main aims of the present study were to examine the most important medical articles(i.e.,the top 100 most cited)on *** examine how the Nobel-prize awarded hypoxia inducible factor(HIF)-pathway discovery in the early 1990s has changed the thematic composition of this body of literature,with a special emphasis on the studies linking hypoxia and *** searched Pubmed for articles with the terms#Hypox,#Altitude,or#Mountain in the title that have been published in biomedical journals and ranked the articles on their number of citations in Web of Science.A second search was performed in all journals for articles related to hypoxia and ***,only 12 of the top-100 most-cited articles on hypoxia and only 3 articles of the top-100 articles related to cancer were published before ***,only 5 articles from prior 1995 reached 1000 citations,while 27 articles published in 1995 or later were cited more than 1000 times,most of them on the HIF-1 *** percent of the top-100 articles were related to the HIF pathway,while there were no articles on the application of hypoxia either for therapeutic use(i.e.,hypoxic conditioning in patients)or for performance enhancement(i.e.,altitude training in athletes).In conclusion,the early-1990s discovery of the HIF pathway and of its molecular regulation has shifted the focus of hypoxia research towards molecular mechanisms and consequences of tissue hypoxia,most notably in *** importance of studies focusing on clinical and performance applications of systemic hypoxia is relatively lower.

关键词： Altitude training Cancer Hypoxia HIF pathway Mountain

Sucrose transporters and plasmodesmal regulation in passive phloem loading

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Journal of Integrative Plant Biology 2017年第5期59卷 311-321页

作者： johannes Liesche College of Life Science Northwest A&F University No 3 Taicheng Road Yangling 712100 China Biomass Energy Center for Arid and Semi-arid lands Northwest A&F University Yangling 712100 China

An essential step for the distribution of carbon throughout the whole plant is the loading of sugars into the phloem in source organs. In many plants, accumulation of sugars in the sieve element-companion cell （SE-CC） complex is mediated and regulated by active processes. However, for poplar and many other tree species, a passive symplasmic mechanism of phloem loading has been proposed, characterized by symplasmic continuity along the pre-phloem pathway and the absence of active sugar accumulation in the SE-CC complex. A high overall leaf sugar concentration is thought to enable diffusion of sucrose into the phloem. In this review, we critically evaluate current evidence regarding the mechanism of passive syrnplasmic phloem loading, with a focus on the potential influence of active sugar transport and plasmo- desmal regulation. The limited experimental data, com- bined with theoretical considerations, suggest that a concomitant operation of passive symplasmic and active phloem loading in the same minor vein is unlikely. However, active sugar transport could well play an important role in how passively loading plants might modulate the rate of sugar export from leaves. Insights into the operation of this mechanism has direct implications for our understanding of how these plants utilize assimilated carbon.

关键词： William J. Lucas University of California Davis USA

The role of sphingosine-1-phosphate in bone remodeling and osteoporosis

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Bone Research 2022年第2期10卷 265-273页

作者： Justus M.Grewe Paul-Richard Knapstein Antonia Donat Shan Jiang Daniel JSmit Weixin Xie johannes Keller Department of Trauma and Orthopedic Surgery University Medical Center Hamburg-Eppendorf20246 HamburgGermany Clinic and Polyclinic for Vascular Medicine University Heart Center Hamburg-Eppendorf20246 HamburgGermany Institute of Biochemistry and Signal Transduction University Medical Center Hamburg-Eppendorf20246 HamburgGermany

Osteoporosis is a systemic bone disease that affects more than 200 million people worldwide and is caused by the disruption of the equilibrium between osteoclastic bone resorption and osteoblastic bone formation. Sphingosine-1-phosphate(S1 P) is a natural,bioactive sphingolipid that has been shown to play a major role in cardiovascular and immunological pathologies by regulating biological and cellular processes, including migration, differentiation, proliferation and survival. Recent studies also suggest a central role for S1 P in bone diseases, including osteoporosis;however, the effects of S1 P, particularly in bone metabolism, remain to be further elucidated. In this review, we summarize the available literature on the role of S1 P in bone metabolism with a focus on osteoporosis. On the cellular level, S1 P acts as an osteoclast-osteoblast coupling factor to promote osteoblast proliferation and bone formation. Moreover, the recruitment of osteoclast precursors to resorption sites is regulated by the interplay of S1 P gradients and S1 P receptor expression. From a clinical perspective, increasing evidence suggests that systemically elevated S1 P blood levels may serve as an independent risk factor for osteoporosis-related fractures. Taken together, S1 P signaling is a potential therapeutic target and may serve as a novel biomarker in patients with systemic bone disease.

关键词： osteoporosis metabolism expression.

Mapping forest age using National Forest Inventory,airborne laser scanning,and Sentinel-2 data

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Forest Ecosystems 2020年第4期7卷 793-806页

作者： johannes Schumacher Marius Hauglin Rasmus Astrup johannes Breidenbach National Forest Inventory Norwegian Institute of Bioeconomy ResearchÅsNorway

Background:The age of forest stands is critical information for forest management and conservation,for example for growth modelling,timing of management activities and harvesting,or decisions about protection ***,area-wide information about forest stand age often does not *** this study,we developed regression models for large-scale area-wide prediction of age in Norwegian *** model development we used more than 4800 plots of the Norwegian National Forest Inventory(NFI)distributed over Norway between latitudes 58°and 65°N in an 18.2 Mha study *** variables were based on airborne laser scanning(ALS),Sentinel-2,and existing public map *** performed model validation on an independent data set consisting of 63 spruce stands with known ***:The best modelling strategy was to fit independent linear regression models to each observed site index(SI)level and using a SI prediction map in the application of the *** most important predictor variable was an upper percentile of the ALS heights,and root mean squared errors(RMSEs)ranged between 3 and 31 years(6%to 26%)for SI-specific models,and 21 years(25%)on *** deviance(MD)ranged between^(−1) and 3 *** models improved with increasing SI and the RMSEs were largest for low SI stands older than 100 *** a mapped SI,which is required for practical applications,RMSE and MD on plot level ranged from 19 to 56 years(29%to 53%),and 5 to 37 years(5%to 31%),*** the validation stands,the RMSE and MD were 12(22%)and 2 years(3%),***:Tree height estimated from airborne laser scanning and predicted site index were the most important variables in the models describing ***,we obtained good results,especially for stands with high *** models could be considered for practical applications,although we see considerable potential for improvements if better SI maps were available.

关键词： Forest age Lidar Optical satellite images Remote sensing Forest inventory

Construction of charge transfer chain in Bi_(12)TiO_(20)-Bi_(4)Ti_(3)O_(12)/α-Bi_(2)O_(3)composites to accelerate photogenerated charge separation

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Nano Research 2023年第3期16卷 3730-3740页

作者： Jincheng Yin Xuebing Chen Guanna Li Dongxu Liu Chun Li Rengui Li Bingxing Xie johannes H.Bitter Jing Zhang School of Environmental and Safety Engineering Liaoning Petrochemical UniversityFushun 113001China Biobased Chemistry and Technology Wageningen University&ResearchStippeneng 4Wageningen 6708 WEThe Netherlands Laboratory of Organic Chemistry Wageningen University&ResearchBornse Weilanden 9Wageningen 6708 WGThe Netherlands State Key Laboratory of Catalysis Dalian National Laboratory for Clean EnergyDalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China School of New Energy Nanjing University of Science and TechnologyJiangyin 214000China

Photogenerated charge separation and transfer is one of the bottleneck steps in photocatalysis,and efficient charge separation strategies are strongly ***,mimicking the electron transport chain in natural photosynthesis,we report the design and fabrication of a charge transfer chain using bismuth-based semiconductor as a *** view of the thermodynamic energy band positions and structural similarity based on the density functional theory(DFT)analysis,heterostructured combination ofα-Bi_(2)O_(3),perovskite-like Bi_(4)Ti_(3)O_(12),and sillenite Bi12TiO20 was designed for fabrication of charge transfer *** tuning the molar ratio of Bi and Ti precursors,the Bi_(4)Ti_(3)O_(12)and Bi12TiO20 particles were formed on the surface ofα-Bi_(2)O_(3)by an insitu transformation process,giving rise to Bi_(12)TiO_(20)-Bi_(4)Ti_(3)O_(12)/α-Bi_(2)O_(3)composites with charge transfer *** propose that the effective charge transfer is accomplished amongα-Bi_(2)O_(3),Bi12TiO20,and Bi_(4)Ti_(3)O_(12),which significantly improves the photogenerated charge separation and transfer,as indicated by photoluminescene,time-resolved photoluminescene,and electrochemical impedance spectra *** expected,the Bi_(12)TiO_(20)-Bi_(4)Ti_(3)O_(12)/α-Bi_(2)O_(3)shows the superior photocatalytic activity for the degradation of environmental pollutants with high *** for the refractory pollutants like 4-chlorophenol,the optimal Bi_(12)TiO_(20)-Bi_(4)Ti_(3)O_(12)/α-Bi_(2)O_(3)composite shows 28 times higher than that ofα-Bi_(2)O_(3)for photocatalytic degradation,verifying the superiority of photogenerated charge transfer chain in *** work demonstrates the feasibility of the charge transfer chain strategy to boost the photogenerated charge separation,which is of great significance for designing energy and environmental-related materials in heterogonous photocatalysis.

关键词： photogenerated charge separation charge transfer chain bismuth titanates bismuth oxides

Assessment of hindlimb motor recovery affer severe thoracic spinal cord injury in rats: classification of CatWalk XT■ gait analysis parameters

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Neural Regeneration Research 2023年第5期18卷 1084-1089页

作者： Guoli Zheng Hao Zhang Mohamed Tail Hao Wang johannes Walter Thomas Skutella Andreas Unterberg Klaus Zweckberger Alexander Younsi Department of Neurosurgery University Hospital HeidelbergHeidelbergGermany Department of Neuroanatomy Institute for Anatomy and Cell BiologyUniversity of HeidelbergHeidelbergGermany

Assessment of locomotion recovery in preclinical studies of experimental spinal cord injury remains challenging. We studied the CatWalk XT■gait analysis for evaluating hindlimb functional recovery in a widely used and clinically relevant thoracic contusion/compression spinal cord injury model in rats. Rats were randomly assigned to either a T9 spinal cord injury or sham laminectomy. Locomotion recovery was assessed using the Basso, Beattie, and Bresnahan open field rating scale and the CatWalk XT■gait analysis. To determine the potential bias from weight changes, corrected hindlimb(H) values(divided by the unaffected forelimb(F) values) were calculated. Six weeks after injury, cyst formation, astrogliosis, and the deposition of chondroitin sulfate glycosaminoglycans were assessed by immunohistochemistry staining. Compared with the baseline, a significant spontaneous recovery could be observed in the CatWalk XT■parameters max intensity, mean intensity, max intensity at%, and max contact mean intensity from 4 weeks after injury onwards. Of note, corrected values(H/F) of CatWalk XT■parameters showed a significantly less vulnerability to the weight changes than absolute values, specifically in static parameters. The corrected CatWalk XT■parameters were positively correlated with the Basso, Beattie, and Bresnahan rating scale scores, cyst formation, the immunointensity of astrogliosis and chondroitin sulfate glycosaminoglycan deposition. The CatWalk XT■gait analysis and especially its static parameters, therefore, seem to be highly useful in assessing spontaneous recovery of hindlimb function after severe thoracic spinal cord injury. Because many CatWalk XT■parameters of the hindlimbs seem to be affected by body weight changes, using their corrected values might be a valuable option to improve this dependency.

关键词： Basso Beattie and Bresnahan rating scale behavioral assessment CatWalk XT■gait analysis contusive and compressive injury hindlimb motor function histological changes spinal cord injury spontaneous recovery thoracic weight