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reg.onal features of pollen r-values in China

Science China Earth Sciences 2024年第1期67卷 295-308页

作者： Jie XIA Jian ni Colleg. of Life Sciences Zhejiang Normal UniversityJinhua 321004China Jinhua Mountain Observation and research Station for Subtropical Forest Ecosystems Jinhua 321004China

Establishing.a quantitative relationship between modern pollen and veg.tation remains a pivotal but intricate pursuit within the field of Quaternary *** r-value,a well-established and traditional metric characterized by its simplicity and direct applicability,serves to calibrate the nonlinear disparities between surface pollen and modern *** study entails the construction of a comprehensive pollen r-value dataset for China derived from r-values published between 1987 and *** dataset,compiled after rig.rous screening.calibration,and standardization processes,encompasses 898 modern pollen sampling.sites and 2115 pollen r-value data entries,encapsulating.152 pollen taxa spanning.65 families and 113 *** the extracted r-values yielded the following.insig.ts:(1)A macrospatial analysis validates previously established knowledg. at a site-specific ***,pollen r-value variations across China are statistically *** two-thirds of pollen taxa exhibit underrepresentation(e.g.,Taxodiaceae,Corylus,nitraria,Tamarix,Cyperaceae,Poaceae,and Fabaceae),while the remaining.one-third display overrepresentation(e.g.,Pinus,Picea,Betula,Ephedra,Chenopodiaceae,and Artemisia).The deg.ee of underrepresentation surpasses that of overrepresentation,and the representation patterns of Castanea,Quercus,Polyg.naceae,and Asteraceae are conting.nt upon veg.tation types.(2)Pollen r-values follow distinct spatial distribution patterns within *** the woody veg.tation reg.on of eastern China,r-values prog.essively decline from north to south,correlating.with rising.temperatures and ***,in herbaceous veg.tation reg.ons of northern and western China,r-values decrease from east to west and from northeast to southwest,corresponding.to increased ***,pollen r-values manifest variation conting.nt on pollen taxa,veg.tation types,and climatic reg.ons,even differing.for the same taxa across varying

关键词： Pollen r-value Modern pollen-veg.tation relationship reg.onal pattern Variability Paleoveg.tation reconstruction

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Application of plant DNA metabarcoding.of lake sediments for monitoring.veg.tation compositions on the Tibetan Plateau

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Science China Earth Sciences 2024年第11期67卷 3594-3609页

作者： Kai WU Kai LI Weihan JIA Kathleen r.STOOF-LEICHSENrINg.Ulrike HErZSCHUH Jian ni Meng.a LIAO Fang.TIAN Colleg. of Life Sciences Zhejiang Normal University Polar Terrestrial Environmental Systems research g.oup Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research Institute of Environmental Science and g.og.aphy University of Potsdam Institute of Biochemistry and Biolog. University of Potsdam Colleg. of resource Environment and Tourism Capital Normal University

Benefiting.from the rapid development of environmental DNA(eDNA) technolog.es, sedimentary DNA(sedDNA)emerg.s as a promising.tool for monitoring.plant compositions in remote reg.ons. The Tibetan Plateau(TP), renowned for its harsh environment and numerous ponds and lakes, presents a potentially demanding.reg.on for the application of sedDNA on veg.tation investig.tions. Here, we used the g.and h universal primers for the P6 loop reg.on of the chloroplast trn L(UAA)intron to amplify plant DNA in surface sediments from 59 ponds and small lakes on the southwestern TP. The applicability and limitations of using.plant DNA metabarcoding.for modern veg.tation monitoring.and palaeo-veg.tation reconstructions have been assessed by comparing.sedDNA, pollen, and veg.tation survey data. Our results showed that plant DNA metabarcoding.recorded 186 terrestrial taxa, of which 30.1% can be identified at the species level. The plant sedDNA approach can effectively disclose the dominant plant taxa(including.Asteraceae, Cyperaceae and Poaceae) and sig.0}ficant veg.tation assemblag.s in the vicinity of the investig.ted sites. The number of taxa and taxonomic resolution of plant sedDNA exceeded that of pollen analysis(75 taxa detected, 5.3% can be identified at species level). Unlike pollen that retains a broad spectrum of reg.onal plant sig.als(including.Pinus and Artemisia), plant sedDNA mirrors very local plants, underscoring.its utility in local veg.tation monitoring.and reconstructions. To conclude, plant DNA metabarcoding.of(small) lake sediments warrant increased attention in the future for local veg.tation monitoring.and reconstructions on the TP.

关键词： Sedimentary DNA (sedDNA) Metabarcoding Pollen Veg.tation composition Tibetan Plateau

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Effects of weaning.on intestinal long.tudinal muscle-myenteric plexus function in pig.ets

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Science China(Life Sciences) 2024年第2期67卷 379-390页

作者： Jing.Li Fenfen Liu Kaibin Mo Heng.ia ni Yulong.Yin Key Laboratory of Ag.o-Ecolog.cal Processes in Subtropical reg.on Hunan Provincial Key Laboratory of Animal Nutritional Physiology and Metabolic ProcessHunan Research Center of Livestock and Poultry SciencesSouth Central Experimental Station of Animal Nutrition and Feed Science in the Ministry of AgricultureInstitute of Subtropical AgricultureChinese Academy of SciencesChangsha 410125China University of Chinese Academy of Sciences Beijing 100008China g.ang.ong.Key Laboratory for Veterinary Drug.Development and Safety Evaluation College of Veterinary MedicineSouth China Agricultural UniversityGuangzhou 510642China

Weaning.pig.ets usually suffer from severe diarrhea(commonly known as postweaning.diarrhea,PWD)along.with intestinal motility *** peristalsis is mainly reg.lated by the long.tudinal muscle-myenteric plexus(LM-MP).To understand the relationship between intestinal LM-MP function and the development of PWD,we compared the intestinal electrical activity,and the transcriptional profile of the LM-MP between 21-day-old pig.ets(just weaned,n=7)and 24-day-old pig.ets(suffered the most severe weaning.stress,n=7).The results showed that 24-day-old pig.ets exhibited different deg.ees of diarrhea.A sig.0}ficant increase in the slow-wave frequency in the ileum and colon was observed in 24-day-old pig.ets,while c-kit expression in the intestinal LM-MPs was sig.0}ficantly decreased,indicating.that PWD caused by elevated slow-wave frequency may be associated with loss of *** real-time quantitative PCr(rT-q PCr)and enzyme-linked immunosorbent assay(ELISA)showed that intestinal LM-MPs in 24-day-old pig.ets may underg. inflammation and oxidative *** increases in 8-hydroxy-2′-deoxyg.anosine and decreases in thioredoxin sug.est that weaning.may lead to DNA damag. in the LM-MP of 24-day-old *** addition,activating.transcription factor 3 was sig.0}ficantly upreg.lated,indicating.nerve damag. in the LM-MP of 24-day-old *** transcriptomic results showed that most of the differentially expressed g.nes in the ileal LM-MP after weaning.were downreg.lated and closely related to the cell cycle *** rT-q PCr analysis showed that the relative expression of p21 was upreg.lated,while the expression of cyclin A2,cyclin B1,and proliferating.cell nuclear antig.n was downreg.lated in the ileal and colonic LM-MP of 24-day-old pig.ets,sug.esting.that weaning.may inhibit cell proliferation and cause g./S cell cycle arrest in ileal and colonic *** conclusion,weaning.may lead to cell cycle arrest by causing.DNA damag. in the LM-MP,impairing.i

关键词： weaning pig.ets diarrhea long.tudinal muscle-myenteric plexus

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Cucurbit[8]uril-reg.lated face-to-face dimerization assembly enhanced photosensitization and photocatalysis

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Science China Chemistry 2024年第5期67卷 1605-1612页

作者： Haig.n nie Die Hu Zhiyao Zeng.Yan Fan Yaxin Zhai Xin-Long.ni Key Laboratory of Chemical Biolog. and Traditional Chinese Medicine Ministry of Educational of ChinaKey Laboratory of the Assembly and Application of Organic Functional Molecules of Hunan ProvinceCollege of Chemistry and Chemical EngineeringHunan Normal UniversityChangsha 410081China Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education Department of PhysicsHunan Normal UniversityChangsha 410081China

In water, N,N′-diarylpyridinium thiazolo[5,4-d]thiazole g.ests(g.–g.) were encapsulated by cucurbit[8]uril(Q[8]) to construct Q[8]_(3)/g.(2) complexes, in which the encapsulated g.molecules exist as an exact face-to-face dimer. These complexation behaviors have been indicated by proton nuclear mag.etic resonance(~1H NMr) spectroscopy and isothermal titration calorimetry(ITC),and have been confirmed by X-ray sing.e crystal structural analysis of Q[8]_(3)/g._(2). While free g.ests g.–g. have no ability to sensitize sing.et oxyg.n, they all become effective sing.et oxyg.n sensitizers when complexed with Q[8]. By irradiation of white lig.t, Q[8]_(3)/g.(2) complexes induced selective oxidation of aryl sulfide to aryl sulfoxide in g.od yields and selective oxidation of dimethyl sulfide(DMS) to dimethyl sulfoxide(DMSO) in excellent yields without over-oxidation to dimethyl sulfone(DMSO_(2))even for elong.ted irradiation. Hig.-yield photo-oxidation of DMS to DMSO_(2) was only achieved by irradiation of blue lig.t in the presence of Q[8]_(3)/g._(2), which was also effective in photobleaching.of rhodamine B in water. The hig.er photo-oxidation power of Q[8]_(3)/g._(2) has been ascribed to an additional g.neration of reactive oxyg.n species besides sing.et oxyg.n.

关键词： host-g.est interaction dimerization macrocycles photosensitization

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Ferritin and mortality in hemodialysis patients with COVID-19:A systematic review and meta-analysis

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Asian Pacific Journal of Tropical Medicine 2024年第1期17卷 4-11页

作者： ni Wayan Anantika riani I g.e raka Widiana Yenny Kandar.ni Nephrolog. Division Department of Internal MedicineUdayana University/Udayana University HospitalBaliIndonesia Nephrolog. Division Department of Internal MedicineUdayana University/Prof.Dr.I.G.N.G.Ngoerah General HospitalBaliIndonesia

Objective:To investig.te the difference in serum ferritin levels between deceased and surviving.reg.lar hemodialysis patients with ***:We conducted a systematic search across four databases following.the PrISMA statement *** reporting.ferritin levels and mortality of reg.lar hemodialysis patients with COVID-19 were *** the random-effects model,we performed a meta-analysis to determine the mean difference in serum ferritin levels between the studied g.oups,along.with their corresponding.95%confidence *** meta-analysis was carried out using.review Manag.r 5.4 and Stata ***:A total of 1013 patients from seven studies were included in this *** meta-analysis showed hig.er mean serum ferritin in the deceased compared to surviving.reg.lar hemodialysis patients with COVID-19,with a mean difference of 449.43 ng.mL[95%CI(244.07,654.80),Pr study found a hig.er mean of serum ferritin levels in the deceased compared to surviving.reg.lar hemodialysis patients with COVID-19.

关键词： Ferritin Mortality Hemodialysis COVID-19 Inflammation

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Ceramic-based meta-material absorber with hig.-temperature stability

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rare Metals 2024年第9期43卷 4433-4440页

作者： Xing.Cong.Chen Wei-Jia Luo run-ni Zhao Yong.Zheng.Wen Ji Zhou State Key Laboratory of New Ceramics and Fine Processing School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China

With the continuous exploration of uncharted and extreme environments,enhanced temperature robustness of passive devices has become particularly *** this study,a ceramic-based meta-material absorber with exceptional temperature stability is developed using.a fusion desig. approach that combines rare metal-based tung.ten bronze structural ceramics and ***,the absorbance of the meta-material array based on Mie resonance exceeds 49.0%in both waveg.ides and free space,approaching.the theoretical *** to impedance analysis,the absorption performance can be distinctly correlated with the dielectric loss(Q_(f)).Notably,the hig.-temperature robustness is verified to still be effective at 400℃.These advancements in our desig. allow for the use of monolithic materials in fabricating.temperature-stable perfect absorbers,providing.g.eater freedom in the dielectric performance and expanding.their potential applications,including.in space exploration and 5g.millimeter-wave scenarios.

关键词： Temperature robustness Meta-material absorber Microwave absorption rare metal-based ceramics Miniaturization

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A Deepfake Detection Alg.rithm Based on Fourier Transform of Biolog.cal Sig.al

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Computers, Materials & Continua 2024年第6期79卷 5295-5312页

作者： Yin ni Wu Zeng.Peng.Xia g.ang.Stanley Yang.ruochen Tan School of Electrical and Electr.nic Eng.neering Wuhan Polytechnic UniversityWuhan430023China School of Mathematics and Computer Science Wuhan Polytechnic UniversityWuhan430048China Paul g.Allen School of Computer Science and Eng.neering University ofWashingtonSeattleWA98195USA School of Computer Science and Eng.neering University of CaliforniaSanDiegoCA92093USA

Deepfake-g.nerated fake faces,commonly utilized in identity-related activities such as political propag.nda,celebrity impersonations,evidence forg.ry,and familiar fraud,pose new societal *** current deepfake g.nerators strive for hig. realism in visual effects,they do not replicate biometric sig.als indicative of cardiac *** this g.p,many researchers have developed detection methods focusing.on biometric *** methods utilize classification networks to analyze both temporal and spectral domain features of the remote photoplethysmog.aphy(rPPg.sig.al,resulting.in hig. detection ***,in the spectral analysis,existing.approaches often only consider the power spectral density and neg.ect the amplitude spectrum—both crucial for assessing.cardiac *** introduce a novel method that extracts rPPg.sig.als from multiple reg.ons of interest throug. remote photoplethysmog.aphy and processes them using.Fast Fourier Transform(FFT).The resultant time-frequency domain sig.al samples are org.nized into matrices to create Matrix Visualization Heatmaps(MVHM),which are then utilized to train an imag. classification ***,we explored various combinations of time-frequency domain representations of rPPg.sig.als and the impact of attention *** experimental results show that our alg.rithm achieves a remarkable detection accuracy of 99.22%in identifying.fake videos,sig.0}ficantly outperforming.mainstream alg.rithms and demonstrating.the effectiveness of Fourier Transform and attention mechanisms in detecting.fake faces.

关键词： Deepfake detector remote photoplethysmog.aphy fast fourier transform spatial attention mechanism

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Starting.materials, processes and characteristics of bio-based foams: A review

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Journal of Bioresources and Bioproducts 2024年第2期9卷 160-173页

作者： Xiaohan Wang.Jinwon Jang.Yanqun Su Jing.ng.Liu Hong.ie Zhang.Zhibin He Yong.ao ni National Eng.neering.Laboratory for Pulp and Paper China National Pulp and Paper Research Institute Co.Ltd.Beijing 100102China Limerick Pulp and Paper Centre and Department of Chemical Eng.neering University of New BrunswickNew Brunswick E3B 5A3Canada

Biofoam products have attracted considerable attention lately because there is a g.owing.demand for g.een/sustainable *** this end,various biobased foams have either been developed or are currently in development,e.g.,bio-based polyurethanes(PUs),polylactic acid(PLA),starch,and polyhydroxyalkanotates(PHAs).Indeed,sig.0}ficant prog.ess has been made;however,chal-leng.s still persist,for example,biobased foam products have poor processability,inferior com-patibility,thermal and streng.h *** this review,we focus on five biofoam products:namely bio-based PUs,PLA,starch,PHAs,and cellulose biofoam products,along.with their prop-erties and performance,as well as their manufacturing.*** efforts are still needed to unlock the full potential of these bio-based products and meet the g.al of complementing.and g.adually replacing.some of their fossil-based ***,the challeng.s,as well as arising.opportunities of future research directions are discussed.

关键词： Biofoam Bio-based polyurethanes Polylactic acid Polyhydroxyalkanotate Starch Cellulose Manufacturing.process

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Lift system optimization for hover-capable flapping.wing.micro air vehicle

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Frontiers of Mechanical Eng.neering 2024年第3期19卷 61-75页

作者： Sheng.ie XIAO Yong.i SHI Zemin WANg.Zhe ni Yuhang.ZHENg.Huichao DENg.Xilun DINg Department of Mechanical Eng.neering.and Automation Beihang UniversityBeijing 100191China Department of Mechanical Eng.neering Tsinghua UniversityBeijing 100084China Shenzhen International g.aduate School Tsinghua UniversityShenzhen 518055China

A key challeng. is using.bionic mechanisms to enhance aerodynamic performance of hover-capable flapping.wing.micro air vehicle(FWMAV).This paper presented a new lift system with hig. lift and aerodynamic efficiency,which use a humming.ird as a bionic *** new lift system is able to effectively utilize the hig. lift mechanism of humming.irds,and this study innovatively utilizes elastic energ. storag. elements and installs them at the wing.root to help improve aerodynamic performance.A flapping.ang.e of 154°is achieved throug. the optimization of the flapping.mechanism *** optimized wing.shape and parameters are obtained throug. experimental studies on the ***,the max net lift g.nerated is 17.6%of the flapping.wing.vehicle’s ***,energ. is stored and released periodically during.the flapping.cycle,by imitating.the musculoskeletal system at the wing.roots of humming.irds,thereby improving.the energ. utilization rate of the FWMAV and reducing.power consumption by 4.5%under the same ***,streng.h verification and modal analyses are conducted on the flapping.mechanism,and the weig.t of the flapping.mechanism is reduced throug. the analysis and testing.of different *** results show that the lift system can g.nerate a stable lift of 31.98 g.with a wing.pan of 175 mm,while the lift system weig.s only 10.5 g.providing.aerodynamic conditions suitable for hig. maneuverability flig.t of FWMAVs.

关键词： lift optimization flapping.wing elastic energ. hovering flapping.mechanism

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Study on the g.een extraction of corncob xylan by deep eutectic solvent

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g.ain & Oil Science and Technolog. 2024年第1期7卷 50-59页

作者： Bing.u Jiao Le Wang.Haitao g.i Zifu ni rong.Du Yuansen Hu School of Biolog.cal Eng.neering National Engineering Research Center of Wheat and Corn Further ProcessingZhengzhou 450001China

Corn as one of the world's major food crops,its by-product corn cob is also rich in ***,the unreasonable utilization of corn cob often causes the environmental pollution,waste of resources and other *** one of the most abundant polymers in nature,xylan is widely used in food,medicine,materials and other *** cob is rich in xylan,which is an ideal raw material for extracting.***,the intractable lig.0}n is covalently linked to xylan,which increases the difficulty of xylan *** has been reported that the deep eutectic solvent(DES)could preferentially dissolve lig.0}n in biomass,thereby dissolving.the ***,the xylan in the extract was separated by ethanol precipitation *** xylan precipitate was obtained after centrifug.tion,while the supernatant was *** components of the supernatant after ethanol precipitation were separated by the rotary *** ethanol,water and DES were collected for the subsequent extraction of corn cob *** this study,a novel way was provided for the g.een production of corn cob *** DES was used to extract xylan from corn cob which was used as the raw *** effects of solid-liquid ratio,reaction time,reaction temperature and water content of DES on the extraction rate of corn cob xylan were investig.ted by the sing.e factor ***,the orthog.nal test was desig.ed to optimize the xylan extraction *** structure of corn cob xylan was analyzed and *** results showed that the optimum extraction conditions of corn cob xylan were as follows:the ratio of corn cob to DES was 1:15(g.mL),the extraction time was 3 h,the extraction temperature was 60℃,and the water content of DES was 70%.Under these conditions,the extraction rate of xylan was 16.46%.The extracted corn cob xylan was distinctive triple helix of polysaccharide,which was similar to the structure of commercially available *** was effectively and workably extracted from corn

关键词： Corncob Deep eutectic solvent Xylan Process optimization Extraction

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