Forest structure is fundamental in determining ecosystem function,yet the impact of bamboo invasion on these structural characteristics remains unclear.We investigated 219 invasion transects at 41 sites across the dis...Forest structure is fundamental in determining ecosystem function,yet the impact of bamboo invasion on these structural characteristics remains unclear.We investigated 219 invasion transects at 41 sites across the distribution areas of Moso bamboo(Phyllostachys edulis)in China to explore the effects of bamboo invasion on forest structural attributes and diameter–height allometries by comparing paired plots of bamboo,mixed bamboo-tree,and non-bamboo forests along the transects.We found that bamboo invasion decreased the mean and maximum diameter at breast height,maximum height,and total basal area,but increased the mean height,stem density,and scaling exponent for stands.Bamboo also had a higher scaling exponent than tree,particularly in mixed forests,suggesting a greater allocation of biomass to height growth.As invasion intensity increased,bamboo allometry became more plastic and decreased significantly,whereas tree allometry was indirectly promoted by increasing stem density.Additionally,a humid climate may favour the scaling exponents for both bamboo and tree,with only minor contributions from topsoil moisture and nitrogen content.The inherent superiority of diameter–height allometry allows bamboo to outcompete tree and contributes to its invasive success.Our findings provide a theoretical basis for understanding the causes and consequences of bamboo invasion.展开更多
Invasive alien plant species(IAPS)pose severe threats to global biodiversity conservation.Effective management of IAPS requires mapping their distribution and identifying the environmental factors that drive their spr...Invasive alien plant species(IAPS)pose severe threats to global biodiversity conservation.Effective management of IAPS requires mapping their distribution and identifying the environmental factors that drive their spread.The Gaoligong Mountains,a renowned biodiversity hotspot in southwestern China,currently face the dual challenges of IAPS invasion and climate change.However,we know little about the distribution patterns,key environmental drivers,and sensitivity of IAPS to future climate change in this region.In this study,we mapped IAPS richness distribution and identified invasion hotspots throughout the Gaoligong Mountains.In addition,we assessed the relative importance of environmental variables in shaping the spatial distribution of IAPS richness and projected potential shifts in IAPS richness under various climate change scenarios.We identified 161 IAPS,primarily concentrated in the low-elevation tropical and subtropical regions along river valleys,forming belt-like invasion hotspots.The key factors shaping IAPS richness included disturbance complexity,elevation,seasonal precipitation,and vegetation types.Notably,IAPS richness significantly declined with increasing elevation and latitude but increased with higher disturbance complexity.Moreover,IAPS were more prevalent in grasslands and shrublands than in forested areas.Ensemble modeling of future climate scenarios predicted that the distribution of IAPS richness would shift to progressively higher elevations.These findings provide valuable insights for managing IAPS in mountainous regions that play a crucial role in global biodiversity conservation.展开更多
Esophageal cancer (EC) is a prevalent malignant tumor that affects the digestive system and is often linked to a poor prognosis. The absence of effective early screening methods results in the diagnosis of esophageal ...Esophageal cancer (EC) is a prevalent malignant tumor that affects the digestive system and is often linked to a poor prognosis. The absence of effective early screening methods results in the diagnosis of esophageal cancer (EC) patients at advanced or metastatic stages. While historically considered incurable, ongoing advancements in medical research have led to the integration of various treatment modalities as primary approaches for managing advanced endometrial cancer. These modalities include surgery, chemotherapy, radiotherapy, targeted therapy, and immunotherapy. Notably, the introduction of targeted therapy and immunotherapy has significantly enhanced the survival rates of individuals with EC. Immunotherapy has appeared as the predominant treatment for advanced esophageal cancer, while targeted therapy faces certain obstacles. Consequently, this review primarily focuses on the advancements in targeted therapy for esophageal cancer (EC), evaluating the effectiveness and safety of relevant medications, and aiming to provide guidance for the comprehensive management of EC based on current research findings.展开更多
Due to their promising applications in foldable displays,optical communication equipment and environmental monitoring systems,flexible and broadband optoelectronic devices have gained extensive attention in recent yea...Due to their promising applications in foldable displays,optical communication equipment and environmental monitoring systems,flexible and broadband optoelectronic devices have gained extensive attention in recent years.Here,a flexible and broadband photodetector based on CsPbBr_(3)/PbSe quantum dot(QD) heterostructures is firstly presented.The integrated QD heterostructures possess consecutive detection range from ultraviolet(UV) to long-wave length infrared(LW-IR) regions with efficient light absorption and chemical stability,in comparison with the pristine PbSe QDs.Systematic material characterizations reveal the improved exciton dissociation,carrier transport and carrier lifetime of the QD heterostructures.Flexible photodetector Ag/CsPbBr_(3)/PbSe/Ag demonstrate a high responsivity of 7.17 A/W with a specific detectivity of 8.97 × 10^(12) Jones under 25 μW/cm^(2) 365 nm illumination at 5 V.Furthermore,it could maintain 91.2 %(or 94.9 %) of its initial performance even after bending for thousands of times(or exposing in ambient air for 4 weeks).More importantly,its re s ponse time is shortened more than three orders of magnitude as that of pristine PbSe QDs-based photodetectors.Therefore,it provides a feasible and promising method for the next-generation high-performance broadband photodetectors via constructing heterostructures of various QDs.展开更多
Commercial photodetectors based on silicon are extensively applied in numerous fields.Except for their high performance,their maximum absorption wavelength is not over than 1100 nm and incident light with longer wavel...Commercial photodetectors based on silicon are extensively applied in numerous fields.Except for their high performance,their maximum absorption wavelength is not over than 1100 nm and incident light with longer wavelengths cannot be detected;in addition,their cost is high and their manufacturing process is complex.Therefore,it is meaningful and significant to extend absorption wavelength,to decrease cost,and to simplify the manufacturing process while maintaining high performance for photodetectors.Due to the properties of size-dependent bandgap tunability,low cost,facile processing,and substrate compatibility,solution–processed colloidal quantum dots(CQDs)have recently gained significant attention and become one of the most competitive and promising candidates for optoelectronic devices.Among these CQDs,lead chalcogenide CQDs are getting very prominent and are widely investigated.In this paper,the recent progress of infrared(IR)photodetectors based on lead sulfide(PbS),lead selenide(PbSe),and ternary PbS_x Se_(1-x)CQDs,and their underlying concepts,breakthroughs,and remaining challenges are reviewed,thus providing guidance for designing high-performance quantum-dot IR photodetectors.展开更多
In order to enhance the efficiency of spectrum utilization and reduce communication overhead in spectrum sharing process, we propose a two-stage dynamic spectrum sharing scheme in which cooperative and noncooperative ...In order to enhance the efficiency of spectrum utilization and reduce communication overhead in spectrum sharing process, we propose a two-stage dynamic spectrum sharing scheme in which cooperative and noncooperative modes are analyzed in both stages. In particular, the existence and the uniqueness of Nash Equilibrium(NE) strategies for noncooperative mode are proved. In addition, a distributed iterative algorithm is proposed to obtain the optimal solutions of the scheme. Simulation studies are carried out to show the performance comparison between two modes as well as the system revenue improvement of the proposed scheme compared with a conventional scheme without a virtual price control factor.展开更多
An energy effi cient resource allocation scheme in timesharing multiuser system with a hybrid energy harvesting transmitter is studied in this paper. Specially, the operation energy of system is supplied by constant e...An energy effi cient resource allocation scheme in timesharing multiuser system with a hybrid energy harvesting transmitter is studied in this paper. Specially, the operation energy of system is supplied by constant energy and energy harvesting, which harvests energy from external environment. Our goal is to maximize the energy effi ciency of timesharing multiuser systems by considering jointly allocation of transmission time and power control in an off-line manner. The original nonconvex objective function is transformed into convex optimization problem via the fractional programming approach. Then, we solve the convex problem by Lagrange dual decomposition method. Simulation results show that the proposed energy efficient resource allocation scheme has a better performance than the scheme which decomposes optimization problem into two parts(power allocation, time allocation) to solve iteratively.展开更多
Nanomedicine has emerged as a dynamically evolving frontier in contemporary medical research.However,the development of nanomedicine is impeded by significant challenges due to its complex,multidisciplinary nature,nec...Nanomedicine has emerged as a dynamically evolving frontier in contemporary medical research.However,the development of nanomedicine is impeded by significant challenges due to its complex,multidisciplinary nature,necessitating the exploration of innovative solutions.Artificial intelligence(AI)has established itself as a pivotal and rapidly advancing domain within nanomedicine research.By leveraging its robust data processing and analytical capabilities,AI can efficiently analyze large datasets and accurately predict the properties and medical functions of nanomaterials.Over the past years,AI applications have proliferated across critical nanomedicine subdomains,including intelligent nanobiosensors for precision diagnostics,AI-optimized nanocarriers for targeted drug delivery,machine learning-guided adjuvant therapy systems,and predictive computational models for nanosafety evaluation.This review aims to provide a thorough analysis of AI's influence throughout the entire spectrum of nanomedicine,as well as the formidable challenges and extraordinary potential for pioneering researchers.展开更多
Taurine is a sulfur-containing nonproteinogenic amino acid.Recent studies have shown that taurine can improve rumen microbial crude protein(MCP)synthesis.This experiment aimed to investigate the action mechanisms of t...Taurine is a sulfur-containing nonproteinogenic amino acid.Recent studies have shown that taurine can improve rumen microbial crude protein(MCP)synthesis.This experiment aimed to investigate the action mechanisms of taurine on rumen MCP synthesis and nitrogen(N)metabolism in beef steers using sodium sulfate(Na_(2)SO_(4))as a contrast.Six steers(bodyweight 506±17 kg)were assigned to three experimental groups including a basal diet(control),the basal diet supplemented with 45 g taurine/d or 50 g Na_(2)SO_(4)/d,and were allocated in a replicated 3×3 Latin square design.The amounts of sulfur from taurine and Na_(2)SO_(4)were equal(11.38 g/d).The results showed that,compared with the control group,both taurine and Na_(2)SO_(4)increased ruminal MCP concentration(P<0.05)by 37.50%and 29.17%,respectively,and increased ruminal sulfide(S2−)concentration(P<0.001).Both taurine and Na_(2)SO_(4)increased neutral detergent fiber digestibility(P<0.05).Taurine tended to increase(P=0.087)while Na_(2)SO_(4)decreased(P=0.049)plasma urea concentration,while the taurine group exhibiting higher plasma urea concentration than the Na_(2)SO_(4)group(P=0.003).Compared with the control group,taurine did not affect urinary urea excretion(P=0.246)whereas Na_(2)SO_(4)decreased urinary urea excretion(P=0.002)and both taurine and Na_(2)SO_(4)increased urinary allantoin excretion(P<0.05),total purine derivatives excretion(P<0.05),and estimated rumen microbial N flow(P<0.05).The urinary urea excretion of the taurine group was higher than the Na_(2)SO_(4)group(P=0.019).Compared with the control group,taurine did not affect N excretion,N retention(NR)or N utilization efficiency(NUE)(P>0.10),but Na_(2)SO_(4)decreased urinary N excretion(P=0.018)and total N excretion(P=0.024),and increased NR(P=0.024)and NUE(P=0.022).No differences were found in NR and NUE between the taurine and Na_(2)SO_(4)groups(P>0.10).Taurine improved ruminal MCP synthesis by enriching the pathways associated with sulfur and amino acid metabolism while Na_(2)SO_(4)improved ruminal MCP synthesis by enriching pathways related to nucleotide and purine metabolism.In conclusion,both taurine and Na_(2)SO_(4)improved ruminal MCP synthesis by modulating different pathways.Taurine was less effective in decreasing total N excretion than Na_(2)SO_(4)but no differences in NR and NUE were found between the two treatments.展开更多
Recent research has demonstrated that rumen-protected taurine supplementation improves body protein turnover,apparent nitrogen retention(ANR)and nitrogen(N)utilization efficiency(NUE)in beef steers.To further elucidat...Recent research has demonstrated that rumen-protected taurine supplementation improves body protein turnover,apparent nitrogen retention(ANR)and nitrogen(N)utilization efficiency(NUE)in beef steers.To further elucidate taurine's role in N metabolism,it is essential to examine whether taurine depletion adversely affects ANR and NUE.Six beef steers(bodyweight 391±10 kg)were allocated in a replicated 3×3 Latin square design.Each experimental period was 20 d,including 15 d for adaptation and 5 d for sampling.Three levels of rumen-protectedβ-alanine(RPβA,a taurine inhibitor),i.e.,0,17.5,and 35 g/d,were added to the basal diet as dietary treatments.The results showed that RPβA supplementations at 17.5 and 35 g/d linearly decreased the plasma taurine concentrationby 12.54%and 22.54%(P=0.026),and the urinary taurine excretion by 15.78%and 21.05%(P<0.001),respectively,while linearly increased ANR(P<0.001)and NUE(P<0.001)in steers.Rumen-protectedβ-alanine supplementation linearly increased the plasma concentrations of methionine(Met,P<0.001),lysine(Lys,P=0.018),threonine(Thr,P=0.011),leucine(Leu,P=0.042)and histidine(His,P=0.061),as well as growth hormone(P<0.001),insulin-like growth factor-1(P<0.001),and the total antioxidant capacity(P<0.001).Rumen-protectedβ-alanine supplementation tended to decrease the skeletal muscle protein degradation rate(P=0.055).Specifically,supplementation with 35 g/d RPβA upregulated the plasma amino acid derivatives and oligopeptides,including N-linoleoyl-histidine(P<0.001),L-Met(P<0.001),L-4-chlorotryptophan(P=0.006),L-Thr(P=0.022),L-Lys(P=0.026),L-carnitine(P=0.038),suberic acid(P=0.036),formyllysine(P=0.036),N-acetyltyrosine(P=0.042),histidylglycine(P=0.045),and N-formyl-L-glutamic acid(P=0.047).Supplementation with 35 g/d RPβA also altered the muscle cell mRNA expression,upregulated hub genes(GADPH,PFKM,TPII,PGK1,and PKM)and modified arginine-proline metabolism and the AMPK signaling pathway in beef steers.In conclusion,RPβA supplementation effectively reduced the plasma taurine concentrations and improved the ANR and NUE in steers.These effects were mediated by modulation of plasma amino acid profiles and metabolomic pathways,which appear to counteract the negative impacts of taurine depletion on N metabolism.展开更多
The objectives of the experiment were to compare the effects of rumen-protected taurine (RPT) and rumen-protected methionine (RPM) on the nitrogen (N) metabolism,plasma biochemical parameters,and metabolomics in beef ...The objectives of the experiment were to compare the effects of rumen-protected taurine (RPT) and rumen-protected methionine (RPM) on the nitrogen (N) metabolism,plasma biochemical parameters,and metabolomics in beef steers and to clarify whether taurine plays similar roles as methionine (Met) in the regulation of N metabolism in beef steers.Six Simmental steers aged 12 months (liveweight325±7 kg) were used as experimental animals.The experimental treatments included a basal diet,the basal diet+70.0 g/d RPT and the basal diet+74.2 g/d RPM.The treatments were assigned in a replicated3×3 Latin square design.Each experimental period included 15 d for adaptation and 5 d for sampling.The results showed that supplementing the diet with RPT or RPM did not affect the apparent nutrient digestibility (P>0.05).Supplementing the diet with RPT or RPM increased the N retention (P<0.05) and the N utilization efficiency (NUE)(P<0.05) and decreased the urinary excretion of 3-methylhistidine(P<0.05) and the estimated skeletal protein degradation rate (P<0.05).Supplementing the diet with RPT increased the plasma concentrations of taurine (P<0.001),cysteine (P=0.010),valine (P=0.013)and total non-essential amino acids (NEAA)(P=0.047) and tended to increase the plasma concentrations of essential amino acids (EAA)+NEAA (P=0.087),but it did not affect the plasma concentrations of total EAA (P>0.05).Supplementing the diet with RPM increased the plasma concentrations of methionine(P=0.033),lysine (P=0.047),cysteine (P=0.007),leucine (P=0.046),isoleucine (P=0.046),valine(P=0.034),total EAA (P=0.028),total NEAA (P=0.004) and EAA+NEAA (P=0.004).The plasma metabolomics profiling revealed that supplementing the diet with RPT upregulated the plasma concentrations of taurine (P<0.001),L-cysteine (P=0.004) and some amino acid (AA) analogues (P<0.05)and RPM upregulated the plasma concentrations of Met (P=0.021),L-isoleucine (P=0.036),L-tryptophan (P=0.006) and some AA analogues (P<0.05).In conclusion,taurine has similar impacts to Met in improving the N retention and the NUE in beef steers.Taurine deficiency negatively affects the NUE of beef steers.Supplementation of the diet with taurine is beneficial to the N utilization in beef steers.展开更多
Magnetic resonance imaging(MRI) has been extensively used in clinical diagnosis and currently over 30% MRI runs are performed in the presence of contrast agents. However, commercially available contrast agents origina...Magnetic resonance imaging(MRI) has been extensively used in clinical diagnosis and currently over 30% MRI runs are performed in the presence of contrast agents. However, commercially available contrast agents originated from small molecules typically exhibit relatively low relaxivities and insufficient circulation time. Therefore, there is a long pursuit to develop new contrast agents with high relaxivities to discriminate pathological tissues from normal ones. Compared with small molecule MRI contrast agents, the incorporation of small molecule contrast agents into macromolecular scaffolds allows for constructing macromolecular MRI contrast agents, remarkably elevating the relaxivities due in part to increased rotational correlation time(τR). Moreover, if the macromolecular scaffolds are responsive to external stimuli, the MRI signals could be selectively switched on at the desired sites(e.g., pathological tissues), further intensifying the imaging contrast. In this feature article, we outline the recent achievements in the fabrication of stimuli-responsive macromolecular MRI contrast agents. Specifically, macromolecular contrast agents being responsive to acidic p H, redox potentials, and other stimuli including photoirradiation, pathogens, and salt concentration are discussed. These smart contrast agents could affect either longitudinal(T1) or transverse(T2) relaxation times of water protons or other nuclei(e.g.,19 F), exhibiting enhanced signals in pathological tissues yet suppressed signals in normal ones and displaying promising potentials in in vitro and in vivo MRI applications.展开更多
Casualty prediction is meaningful to the emergency management of natural hazards and human-induced disasters.In this study,a two-step machine learning method,including classification step and regression step,is propos...Casualty prediction is meaningful to the emergency management of natural hazards and human-induced disasters.In this study,a two-step machine learning method,including classification step and regression step,is proposed to predict the number of casualties under emergencies.In the classification step,whether there are casualties under an incident is firstly predicted,then in the regression step,samples predicted to have casualties are used to further predict the exact number of the casualties.Using an open-source dataset,this two-step method is validated.The results show that the two-step model performs better than the original regression models.Back propagation(BP)neural network combined with Random Forest performs the best in terms of the death toll and the number of injuries.Among all the two-step models,the lowest mean absolute error(MAE)for the death toll is 1.67 while that for the number of injuries is 4.13,which indicates that this method can accurately predict the number of casualties under emergencies.This study’s results are expected to provide support for decision-making on rapid resource allocation and other emergency responses.展开更多
Polymer chain architectures play a crucial role in the physical properties of polymers and this unique phenomenon has been recognized as the topological effects.As one of the most representative architectures,macrocyc...Polymer chain architectures play a crucial role in the physical properties of polymers and this unique phenomenon has been recognized as the topological effects.As one of the most representative architectures,macrocyclic polymers characterized by the endless topology have received extensive attention due to their distinct physical properties as compared to the linear counterparts.To understand these differences and unravel the underlying mechanisms,there is a long pursuit to efficiently fabricate macrocyclic polymers.To date,both ring-closing and ring-expansion strategies have been developed,which drastically elevates the accessibility of macrocyclic polymers.The improved availability of macrocyclic polymers enables the further investigation of the biomedical applications and the preliminary results suggest that macrocyclic polymers outperform their linear analogs in terms of improving gene delivery efficiency,elevating blood circulation time,and enhancing colloidal stability of nanoparticles.展开更多
Carbon monoxide(CO)is recognized as a diffusible and biologically membrane-permeable gasotransmitter.However,the question of whether extracellular and intracellular CO delivery would yield similar or distinct biologic...Carbon monoxide(CO)is recognized as a diffusible and biologically membrane-permeable gasotransmitter.However,the question of whether extracellular and intracellular CO delivery would yield similar or distinct biological functions remains unresolved.In this study,utilizing nonmetallic CO-releasing micelles as a platform for localized CO delivery,we present evidence suggesting that selective antibacterial effects against Staphylococcus aureus(S.aureus)are exclusively evident upon intracellular CO release,even in cases of extracellular release with higher CO concentrations showing no comparable effect.To substantiate this assertion,we systematically design micellar nanoparticles with varying sizes,monomer sequences,and shell compositions.Among these variants,only the micelles taken up by S.aureus and capable of intracellular CO release exhibit efficient bacteria-killing properties.We further demonstrate that the selective bactericidal effect is closely linked to the production of hydroxyl radicals after intracellular CO release.Additionally,intracellular CO release proves to be an efficient treatment for S.aureus-induced skin abscesses without the need for additional antibiotics,showcasing synergistic antibacterial and anti-inflammatory effects.These findings underscore the pivotal role of the spatial location of CO release,significantly enhancing our understanding of the pathophysiological functions of gasotransmitters.展开更多
This study investigated the effects of β-alanine(p-Ala)on rumen fermentation,nutrient digestibility,nitrogen(N)metabolism,plasma biochemical parameters,and rumen bacterial communities in beef steers.Six steers with i...This study investigated the effects of β-alanine(p-Ala)on rumen fermentation,nutrient digestibility,nitrogen(N)metabolism,plasma biochemical parameters,and rumen bacterial communities in beef steers.Six steers with initial liveweight of 252.8±5.2 kg and 3 treatments of supplementing with 0,30,or 60 g β-Ala per day to basal diet were allocated in a replicated 3×3 Latin square design.Each experimental period was 20 d,of which the first 15 d were for adaptation and the subsequent 5 d were for sampling.The results showed that β-Ala linearly increased the ruminal concentration of microbial crude protein(MCP)(P=0.005),but it did not affect the ruminal concentrations of ammonia N and total volatile fatty acids(P>0.10).β-Ala also linearly increased the dry matter(DM)(P=0.009),organic matter(OM)(P=0.017)and crude protein(CP)(P=0.043)digestibility,tended to decrease the acid detergent fiber digestibility(P=0.077),but it did not affect the neutral detergent fiber digestibility(P=0.641).β-Ala quadratically increased the relative abundance of ruminal Bacteroidota(P=0.021)at the phylum level,and increased Prevotella(P=0.028)and Prevotellaceae_UCG-003(P=0.014),and decreased the relative abundance of NK4A214_group(P=0.009)at the genus level.Feeding steers with β-Ala linearly increased the urinary N(P=0.006),urea excretions(P=0.002)and the N retention(P=0.004),but it did not affect the N utilization efficiency(P=0.120).β-Ala quadratically increased the plasma concentration of the total antioxidant capacity(P=0.011)and linearly increased the plasma concentration of insulin-like growth factor-1(P<0.001).In summary,dietary supplementation with β-Ala improved the rumen MCP supply and increased the digestibility of DM,OM,CP and the N retention.Further research is necessary to verify the ruminal degradability of β-Ala and to investigate the mech-anism of the impact of absorbed β-Ala on the anti-oxidative ability in steers.展开更多
Purpose K-edge imaging based on the photon counting detectors(PCDs)is an effective enhanced imaging method because the PCDs are conducive to the K-edge imaging due to the adjustable energy thresholds.The energy bins s...Purpose K-edge imaging based on the photon counting detectors(PCDs)is an effective enhanced imaging method because the PCDs are conducive to the K-edge imaging due to the adjustable energy thresholds.The energy bins significantly affect the image quality of the K-edge imaging,but the conventional energy bins used for K-edge imaging are continuous which weaken the K-edge signal and decline the image quality.Hence,how to get a better K-edge signal by the optimized energy bins is the key point for the K-edge imaging based on the PCDs.Method This paper experimentally studied the influence of the energy bins used for the K-edge imaging based on the PCDs.The conventional energy bins were determined by the theoretical-attenuation method(TAM),and the optimized energy bins were determined by the threshold-scan method(TSM).For the phantom and mice imaging,we performed both the K-edge subtraction algorithm and the K-edge decomposition algorithm on the projections obtained by the energy bins which were determined by the TAM and TSM.The image quality was compared using the CNR of the objective area.Results The experimental results showed that the energy bins identified by the TSM had a better performance than the TAM in both imaging methods.The TSM improved the CNR by~39%than the TAM in the phantom results and could better highlight the areas where the contrast agents are enriched(such as the kidney).Conclusions The optimized energy bins can better highlight the K-edge signal than the conventional energy bins which can improve the image quality and have the potential to reduce the amount of the contrast agents.展开更多
The aims of the present study were to investigate the effects of dietary supplementation with rumenprotected taurine(RPT)on the whole-body protein turnover,the plasma metabolomics,and the whole blood cell transcriptom...The aims of the present study were to investigate the effects of dietary supplementation with rumenprotected taurine(RPT)on the whole-body protein turnover,the plasma metabolomics,and the whole blood cell transcriptomics in steers.Eight steers,averaging 220±3.26 kg of liveweight,were allocated in a replicate 4×4 Latin square design.The experimental treatments consisted of four levels of RPT supplementation:0,25,50,and 75 g RPT per day,added to a basal diet.The results showed that supplementation with RPT linearly decreased the fecal nitrogen(N)excretion(P=0.001)and the 15N fractional recovery rate(P=0.047),while it linearly increased the urinary excretion of taurine(P=0.045)as well as the average daily weight gain(P=0.003),the protein synthesis(P<0.001),the protein degradation(P<0.001)and the whole-body protein turnover(P<0.001).Supplementation with RPT linearly increased the plasma concentrations of growth hormone(P=0.005)and quadratically affected the plasma concentration of insulin-like growth factor-1(P=0.013),and it linearly decreased the plasma concentration of albumin(P=0.022).Supplementation with RPT altered the whole blood cell mRNA expression and upregulated the expressions of the marker genes,including RPS6KB1,PRSS42,COL1A2,ENSBTAG00000013055 and ENSBTAG00000038159 which are related to protein metabolism.The plasma metabolomics profiling indicated that supplementation with RPT upregulated the plasma concentrations of taurine,lysine and methionine.The experiment revealed the impact and the mechanisms of taurine on driving whole-body protein turnover and protein accretion in steers.Two novel marker genes which could be related to body protein degradation in steers were identified.展开更多
基金supported by the National Natural Science Foundation of China(No.31988102)Yunnan Province Major Program for Basic Research Project(No.202101BC070002)+1 种基金Yunnan Province Science and Technology Talents and Platform Program(No.202305AA160014)Yunnan Province Key Research and Development Program of China(No.202303AC100009)。
文摘Forest structure is fundamental in determining ecosystem function,yet the impact of bamboo invasion on these structural characteristics remains unclear.We investigated 219 invasion transects at 41 sites across the distribution areas of Moso bamboo(Phyllostachys edulis)in China to explore the effects of bamboo invasion on forest structural attributes and diameter–height allometries by comparing paired plots of bamboo,mixed bamboo-tree,and non-bamboo forests along the transects.We found that bamboo invasion decreased the mean and maximum diameter at breast height,maximum height,and total basal area,but increased the mean height,stem density,and scaling exponent for stands.Bamboo also had a higher scaling exponent than tree,particularly in mixed forests,suggesting a greater allocation of biomass to height growth.As invasion intensity increased,bamboo allometry became more plastic and decreased significantly,whereas tree allometry was indirectly promoted by increasing stem density.Additionally,a humid climate may favour the scaling exponents for both bamboo and tree,with only minor contributions from topsoil moisture and nitrogen content.The inherent superiority of diameter–height allometry allows bamboo to outcompete tree and contributes to its invasive success.Our findings provide a theoretical basis for understanding the causes and consequences of bamboo invasion.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research(STEP)Program(Grant No.2019QZKK0502)National Natural Science Foundation of China(Grant No.U23A20160)Shanghai Science and Technology Innovation Action Plan(Grant No.23015810100).
文摘Invasive alien plant species(IAPS)pose severe threats to global biodiversity conservation.Effective management of IAPS requires mapping their distribution and identifying the environmental factors that drive their spread.The Gaoligong Mountains,a renowned biodiversity hotspot in southwestern China,currently face the dual challenges of IAPS invasion and climate change.However,we know little about the distribution patterns,key environmental drivers,and sensitivity of IAPS to future climate change in this region.In this study,we mapped IAPS richness distribution and identified invasion hotspots throughout the Gaoligong Mountains.In addition,we assessed the relative importance of environmental variables in shaping the spatial distribution of IAPS richness and projected potential shifts in IAPS richness under various climate change scenarios.We identified 161 IAPS,primarily concentrated in the low-elevation tropical and subtropical regions along river valleys,forming belt-like invasion hotspots.The key factors shaping IAPS richness included disturbance complexity,elevation,seasonal precipitation,and vegetation types.Notably,IAPS richness significantly declined with increasing elevation and latitude but increased with higher disturbance complexity.Moreover,IAPS were more prevalent in grasslands and shrublands than in forested areas.Ensemble modeling of future climate scenarios predicted that the distribution of IAPS richness would shift to progressively higher elevations.These findings provide valuable insights for managing IAPS in mountainous regions that play a crucial role in global biodiversity conservation.
文摘Esophageal cancer (EC) is a prevalent malignant tumor that affects the digestive system and is often linked to a poor prognosis. The absence of effective early screening methods results in the diagnosis of esophageal cancer (EC) patients at advanced or metastatic stages. While historically considered incurable, ongoing advancements in medical research have led to the integration of various treatment modalities as primary approaches for managing advanced endometrial cancer. These modalities include surgery, chemotherapy, radiotherapy, targeted therapy, and immunotherapy. Notably, the introduction of targeted therapy and immunotherapy has significantly enhanced the survival rates of individuals with EC. Immunotherapy has appeared as the predominant treatment for advanced esophageal cancer, while targeted therapy faces certain obstacles. Consequently, this review primarily focuses on the advancements in targeted therapy for esophageal cancer (EC), evaluating the effectiveness and safety of relevant medications, and aiming to provide guidance for the comprehensive management of EC based on current research findings.
基金partially funded by the Project of State Key Laboratory of Transducer Technology (No. SKT1404)the Fundamental Research Funds for the Central Universities (No. 2020CX02002 and BITBLR2020013)the Key R&D Projects of the Ministry of Science and Technology (No. SQ2019YFB220038)。
文摘Due to their promising applications in foldable displays,optical communication equipment and environmental monitoring systems,flexible and broadband optoelectronic devices have gained extensive attention in recent years.Here,a flexible and broadband photodetector based on CsPbBr_(3)/PbSe quantum dot(QD) heterostructures is firstly presented.The integrated QD heterostructures possess consecutive detection range from ultraviolet(UV) to long-wave length infrared(LW-IR) regions with efficient light absorption and chemical stability,in comparison with the pristine PbSe QDs.Systematic material characterizations reveal the improved exciton dissociation,carrier transport and carrier lifetime of the QD heterostructures.Flexible photodetector Ag/CsPbBr_(3)/PbSe/Ag demonstrate a high responsivity of 7.17 A/W with a specific detectivity of 8.97 × 10^(12) Jones under 25 μW/cm^(2) 365 nm illumination at 5 V.Furthermore,it could maintain 91.2 %(or 94.9 %) of its initial performance even after bending for thousands of times(or exposing in ambient air for 4 weeks).More importantly,its re s ponse time is shortened more than three orders of magnitude as that of pristine PbSe QDs-based photodetectors.Therefore,it provides a feasible and promising method for the next-generation high-performance broadband photodetectors via constructing heterostructures of various QDs.
基金Project supported by the Fund from the State Key Laboratory of Transducer Technology,China(Grant No.SKT1404)the Fund from the Key Laboratory of Photoelectronic Imaging Technology and System(Grant No.2017OEIOF02)at Beijing Institute of Technology,Ministry of Education of China
文摘Commercial photodetectors based on silicon are extensively applied in numerous fields.Except for their high performance,their maximum absorption wavelength is not over than 1100 nm and incident light with longer wavelengths cannot be detected;in addition,their cost is high and their manufacturing process is complex.Therefore,it is meaningful and significant to extend absorption wavelength,to decrease cost,and to simplify the manufacturing process while maintaining high performance for photodetectors.Due to the properties of size-dependent bandgap tunability,low cost,facile processing,and substrate compatibility,solution–processed colloidal quantum dots(CQDs)have recently gained significant attention and become one of the most competitive and promising candidates for optoelectronic devices.Among these CQDs,lead chalcogenide CQDs are getting very prominent and are widely investigated.In this paper,the recent progress of infrared(IR)photodetectors based on lead sulfide(PbS),lead selenide(PbSe),and ternary PbS_x Se_(1-x)CQDs,and their underlying concepts,breakthroughs,and remaining challenges are reviewed,thus providing guidance for designing high-performance quantum-dot IR photodetectors.
基金supported in part by the National Natural Science Foundation of China(61471115)the National Science and Technology Major Project of the Ministry of Science and Technology of China(2014ZX03003010-002)+1 种基金the General Program of Natural Science Foundation of Jiangsu Province(BK20131299)the 2016 Science and Technology joint research and innovation foundation of Jiangsu province(SBY2016020323)
文摘In order to enhance the efficiency of spectrum utilization and reduce communication overhead in spectrum sharing process, we propose a two-stage dynamic spectrum sharing scheme in which cooperative and noncooperative modes are analyzed in both stages. In particular, the existence and the uniqueness of Nash Equilibrium(NE) strategies for noncooperative mode are proved. In addition, a distributed iterative algorithm is proposed to obtain the optimal solutions of the scheme. Simulation studies are carried out to show the performance comparison between two modes as well as the system revenue improvement of the proposed scheme compared with a conventional scheme without a virtual price control factor.
基金supported in part by the National Natural Science Foundation of China(61471115)in part by the 2016 Science and Technology Joint Research and Innovation Foundation of Jiangsu Province(BY2016076-13)
文摘An energy effi cient resource allocation scheme in timesharing multiuser system with a hybrid energy harvesting transmitter is studied in this paper. Specially, the operation energy of system is supplied by constant energy and energy harvesting, which harvests energy from external environment. Our goal is to maximize the energy effi ciency of timesharing multiuser systems by considering jointly allocation of transmission time and power control in an off-line manner. The original nonconvex objective function is transformed into convex optimization problem via the fractional programming approach. Then, we solve the convex problem by Lagrange dual decomposition method. Simulation results show that the proposed energy efficient resource allocation scheme has a better performance than the scheme which decomposes optimization problem into two parts(power allocation, time allocation) to solve iteratively.
基金supported by the Basic Science Center Project of the National Natural Science Foundation of China(22388101)the National Key Research and Development Program of China(2022YFA1207300)+1 种基金the National Natural Science Foundation of China(82204300,32271452,52425306,22374071)the State Key Laboratory of Analytical Chemistry for Life Science(5431ZZXM2501)。
文摘Nanomedicine has emerged as a dynamically evolving frontier in contemporary medical research.However,the development of nanomedicine is impeded by significant challenges due to its complex,multidisciplinary nature,necessitating the exploration of innovative solutions.Artificial intelligence(AI)has established itself as a pivotal and rapidly advancing domain within nanomedicine research.By leveraging its robust data processing and analytical capabilities,AI can efficiently analyze large datasets and accurately predict the properties and medical functions of nanomaterials.Over the past years,AI applications have proliferated across critical nanomedicine subdomains,including intelligent nanobiosensors for precision diagnostics,AI-optimized nanocarriers for targeted drug delivery,machine learning-guided adjuvant therapy systems,and predictive computational models for nanosafety evaluation.This review aims to provide a thorough analysis of AI's influence throughout the entire spectrum of nanomedicine,as well as the formidable challenges and extraordinary potential for pioneering researchers.
基金the National Natural Science Foundation of China for financial support(grant No.32172748)to the research.
文摘Taurine is a sulfur-containing nonproteinogenic amino acid.Recent studies have shown that taurine can improve rumen microbial crude protein(MCP)synthesis.This experiment aimed to investigate the action mechanisms of taurine on rumen MCP synthesis and nitrogen(N)metabolism in beef steers using sodium sulfate(Na_(2)SO_(4))as a contrast.Six steers(bodyweight 506±17 kg)were assigned to three experimental groups including a basal diet(control),the basal diet supplemented with 45 g taurine/d or 50 g Na_(2)SO_(4)/d,and were allocated in a replicated 3×3 Latin square design.The amounts of sulfur from taurine and Na_(2)SO_(4)were equal(11.38 g/d).The results showed that,compared with the control group,both taurine and Na_(2)SO_(4)increased ruminal MCP concentration(P<0.05)by 37.50%and 29.17%,respectively,and increased ruminal sulfide(S2−)concentration(P<0.001).Both taurine and Na_(2)SO_(4)increased neutral detergent fiber digestibility(P<0.05).Taurine tended to increase(P=0.087)while Na_(2)SO_(4)decreased(P=0.049)plasma urea concentration,while the taurine group exhibiting higher plasma urea concentration than the Na_(2)SO_(4)group(P=0.003).Compared with the control group,taurine did not affect urinary urea excretion(P=0.246)whereas Na_(2)SO_(4)decreased urinary urea excretion(P=0.002)and both taurine and Na_(2)SO_(4)increased urinary allantoin excretion(P<0.05),total purine derivatives excretion(P<0.05),and estimated rumen microbial N flow(P<0.05).The urinary urea excretion of the taurine group was higher than the Na_(2)SO_(4)group(P=0.019).Compared with the control group,taurine did not affect N excretion,N retention(NR)or N utilization efficiency(NUE)(P>0.10),but Na_(2)SO_(4)decreased urinary N excretion(P=0.018)and total N excretion(P=0.024),and increased NR(P=0.024)and NUE(P=0.022).No differences were found in NR and NUE between the taurine and Na_(2)SO_(4)groups(P>0.10).Taurine improved ruminal MCP synthesis by enriching the pathways associated with sulfur and amino acid metabolism while Na_(2)SO_(4)improved ruminal MCP synthesis by enriching pathways related to nucleotide and purine metabolism.In conclusion,both taurine and Na_(2)SO_(4)improved ruminal MCP synthesis by modulating different pathways.Taurine was less effective in decreasing total N excretion than Na_(2)SO_(4)but no differences in NR and NUE were found between the two treatments.
基金supported by National Natural Science Foundation of China(grant No.32172748).
文摘Recent research has demonstrated that rumen-protected taurine supplementation improves body protein turnover,apparent nitrogen retention(ANR)and nitrogen(N)utilization efficiency(NUE)in beef steers.To further elucidate taurine's role in N metabolism,it is essential to examine whether taurine depletion adversely affects ANR and NUE.Six beef steers(bodyweight 391±10 kg)were allocated in a replicated 3×3 Latin square design.Each experimental period was 20 d,including 15 d for adaptation and 5 d for sampling.Three levels of rumen-protectedβ-alanine(RPβA,a taurine inhibitor),i.e.,0,17.5,and 35 g/d,were added to the basal diet as dietary treatments.The results showed that RPβA supplementations at 17.5 and 35 g/d linearly decreased the plasma taurine concentrationby 12.54%and 22.54%(P=0.026),and the urinary taurine excretion by 15.78%and 21.05%(P<0.001),respectively,while linearly increased ANR(P<0.001)and NUE(P<0.001)in steers.Rumen-protectedβ-alanine supplementation linearly increased the plasma concentrations of methionine(Met,P<0.001),lysine(Lys,P=0.018),threonine(Thr,P=0.011),leucine(Leu,P=0.042)and histidine(His,P=0.061),as well as growth hormone(P<0.001),insulin-like growth factor-1(P<0.001),and the total antioxidant capacity(P<0.001).Rumen-protectedβ-alanine supplementation tended to decrease the skeletal muscle protein degradation rate(P=0.055).Specifically,supplementation with 35 g/d RPβA upregulated the plasma amino acid derivatives and oligopeptides,including N-linoleoyl-histidine(P<0.001),L-Met(P<0.001),L-4-chlorotryptophan(P=0.006),L-Thr(P=0.022),L-Lys(P=0.026),L-carnitine(P=0.038),suberic acid(P=0.036),formyllysine(P=0.036),N-acetyltyrosine(P=0.042),histidylglycine(P=0.045),and N-formyl-L-glutamic acid(P=0.047).Supplementation with 35 g/d RPβA also altered the muscle cell mRNA expression,upregulated hub genes(GADPH,PFKM,TPII,PGK1,and PKM)and modified arginine-proline metabolism and the AMPK signaling pathway in beef steers.In conclusion,RPβA supplementation effectively reduced the plasma taurine concentrations and improved the ANR and NUE in steers.These effects were mediated by modulation of plasma amino acid profiles and metabolomic pathways,which appear to counteract the negative impacts of taurine depletion on N metabolism.
基金the National Natural Science Foundation of China(grant No.32172748)for financial support.
文摘The objectives of the experiment were to compare the effects of rumen-protected taurine (RPT) and rumen-protected methionine (RPM) on the nitrogen (N) metabolism,plasma biochemical parameters,and metabolomics in beef steers and to clarify whether taurine plays similar roles as methionine (Met) in the regulation of N metabolism in beef steers.Six Simmental steers aged 12 months (liveweight325±7 kg) were used as experimental animals.The experimental treatments included a basal diet,the basal diet+70.0 g/d RPT and the basal diet+74.2 g/d RPM.The treatments were assigned in a replicated3×3 Latin square design.Each experimental period included 15 d for adaptation and 5 d for sampling.The results showed that supplementing the diet with RPT or RPM did not affect the apparent nutrient digestibility (P>0.05).Supplementing the diet with RPT or RPM increased the N retention (P<0.05) and the N utilization efficiency (NUE)(P<0.05) and decreased the urinary excretion of 3-methylhistidine(P<0.05) and the estimated skeletal protein degradation rate (P<0.05).Supplementing the diet with RPT increased the plasma concentrations of taurine (P<0.001),cysteine (P=0.010),valine (P=0.013)and total non-essential amino acids (NEAA)(P=0.047) and tended to increase the plasma concentrations of essential amino acids (EAA)+NEAA (P=0.087),but it did not affect the plasma concentrations of total EAA (P>0.05).Supplementing the diet with RPM increased the plasma concentrations of methionine(P=0.033),lysine (P=0.047),cysteine (P=0.007),leucine (P=0.046),isoleucine (P=0.046),valine(P=0.034),total EAA (P=0.028),total NEAA (P=0.004) and EAA+NEAA (P=0.004).The plasma metabolomics profiling revealed that supplementing the diet with RPT upregulated the plasma concentrations of taurine (P<0.001),L-cysteine (P=0.004) and some amino acid (AA) analogues (P<0.05)and RPM upregulated the plasma concentrations of Met (P=0.021),L-isoleucine (P=0.036),L-tryptophan (P=0.006) and some AA analogues (P<0.05).In conclusion,taurine has similar impacts to Met in improving the N retention and the NUE in beef steers.Taurine deficiency negatively affects the NUE of beef steers.Supplementation of the diet with taurine is beneficial to the N utilization in beef steers.
基金supported by the National Natural Science Foundation of China (51690150, 51690154, 21674103, 51722307, 51673179)the International S&T Cooperation Program of China (ISTCP) of MOST (2016YFE0129700)+1 种基金the Natural Science Foundation of Anhui Province (1708085QB34)the Fundamental Research Funds for the Central Universities (WK3450000003, WK2060200023)
文摘Magnetic resonance imaging(MRI) has been extensively used in clinical diagnosis and currently over 30% MRI runs are performed in the presence of contrast agents. However, commercially available contrast agents originated from small molecules typically exhibit relatively low relaxivities and insufficient circulation time. Therefore, there is a long pursuit to develop new contrast agents with high relaxivities to discriminate pathological tissues from normal ones. Compared with small molecule MRI contrast agents, the incorporation of small molecule contrast agents into macromolecular scaffolds allows for constructing macromolecular MRI contrast agents, remarkably elevating the relaxivities due in part to increased rotational correlation time(τR). Moreover, if the macromolecular scaffolds are responsive to external stimuli, the MRI signals could be selectively switched on at the desired sites(e.g., pathological tissues), further intensifying the imaging contrast. In this feature article, we outline the recent achievements in the fabrication of stimuli-responsive macromolecular MRI contrast agents. Specifically, macromolecular contrast agents being responsive to acidic p H, redox potentials, and other stimuli including photoirradiation, pathogens, and salt concentration are discussed. These smart contrast agents could affect either longitudinal(T1) or transverse(T2) relaxation times of water protons or other nuclei(e.g.,19 F), exhibiting enhanced signals in pathological tissues yet suppressed signals in normal ones and displaying promising potentials in in vitro and in vivo MRI applications.
基金funded by the National Natural Science Foundation of China(Grant No.72174203).
文摘Casualty prediction is meaningful to the emergency management of natural hazards and human-induced disasters.In this study,a two-step machine learning method,including classification step and regression step,is proposed to predict the number of casualties under emergencies.In the classification step,whether there are casualties under an incident is firstly predicted,then in the regression step,samples predicted to have casualties are used to further predict the exact number of the casualties.Using an open-source dataset,this two-step method is validated.The results show that the two-step model performs better than the original regression models.Back propagation(BP)neural network combined with Random Forest performs the best in terms of the death toll and the number of injuries.Among all the two-step models,the lowest mean absolute error(MAE)for the death toll is 1.67 while that for the number of injuries is 4.13,which indicates that this method can accurately predict the number of casualties under emergencies.This study’s results are expected to provide support for decision-making on rapid resource allocation and other emergency responses.
基金supported by the National Natural Science Foundation of China(51690150,51690154,21674103,51673179)International S&T Cooperation Program of China of MOST(2016YFE0129700)
文摘Polymer chain architectures play a crucial role in the physical properties of polymers and this unique phenomenon has been recognized as the topological effects.As one of the most representative architectures,macrocyclic polymers characterized by the endless topology have received extensive attention due to their distinct physical properties as compared to the linear counterparts.To understand these differences and unravel the underlying mechanisms,there is a long pursuit to efficiently fabricate macrocyclic polymers.To date,both ring-closing and ring-expansion strategies have been developed,which drastically elevates the accessibility of macrocyclic polymers.The improved availability of macrocyclic polymers enables the further investigation of the biomedical applications and the preliminary results suggest that macrocyclic polymers outperform their linear analogs in terms of improving gene delivery efficiency,elevating blood circulation time,and enhancing colloidal stability of nanoparticles.
基金supported by the National Natural Scientific Foundation of China(52350348,52233009,52021002,92356302,52273155,and 52073270)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0450301 and XDB0450102)+2 种基金the CAS Project for Young Scientists in Basic Research(YSBR-094)the Joint Funds from Hefei National Synchrotron Radiation Laboratory(KY2060000197)the Collaborative Innovation Program of Hefei Science Center,CAS(2022HSC-CIP012)。
文摘Carbon monoxide(CO)is recognized as a diffusible and biologically membrane-permeable gasotransmitter.However,the question of whether extracellular and intracellular CO delivery would yield similar or distinct biological functions remains unresolved.In this study,utilizing nonmetallic CO-releasing micelles as a platform for localized CO delivery,we present evidence suggesting that selective antibacterial effects against Staphylococcus aureus(S.aureus)are exclusively evident upon intracellular CO release,even in cases of extracellular release with higher CO concentrations showing no comparable effect.To substantiate this assertion,we systematically design micellar nanoparticles with varying sizes,monomer sequences,and shell compositions.Among these variants,only the micelles taken up by S.aureus and capable of intracellular CO release exhibit efficient bacteria-killing properties.We further demonstrate that the selective bactericidal effect is closely linked to the production of hydroxyl radicals after intracellular CO release.Additionally,intracellular CO release proves to be an efficient treatment for S.aureus-induced skin abscesses without the need for additional antibiotics,showcasing synergistic antibacterial and anti-inflammatory effects.These findings underscore the pivotal role of the spatial location of CO release,significantly enhancing our understanding of the pathophysiological functions of gasotransmitters.
基金supported by National Natural Science Foundation of China(Project No.32172748).
文摘This study investigated the effects of β-alanine(p-Ala)on rumen fermentation,nutrient digestibility,nitrogen(N)metabolism,plasma biochemical parameters,and rumen bacterial communities in beef steers.Six steers with initial liveweight of 252.8±5.2 kg and 3 treatments of supplementing with 0,30,or 60 g β-Ala per day to basal diet were allocated in a replicated 3×3 Latin square design.Each experimental period was 20 d,of which the first 15 d were for adaptation and the subsequent 5 d were for sampling.The results showed that β-Ala linearly increased the ruminal concentration of microbial crude protein(MCP)(P=0.005),but it did not affect the ruminal concentrations of ammonia N and total volatile fatty acids(P>0.10).β-Ala also linearly increased the dry matter(DM)(P=0.009),organic matter(OM)(P=0.017)and crude protein(CP)(P=0.043)digestibility,tended to decrease the acid detergent fiber digestibility(P=0.077),but it did not affect the neutral detergent fiber digestibility(P=0.641).β-Ala quadratically increased the relative abundance of ruminal Bacteroidota(P=0.021)at the phylum level,and increased Prevotella(P=0.028)and Prevotellaceae_UCG-003(P=0.014),and decreased the relative abundance of NK4A214_group(P=0.009)at the genus level.Feeding steers with β-Ala linearly increased the urinary N(P=0.006),urea excretions(P=0.002)and the N retention(P=0.004),but it did not affect the N utilization efficiency(P=0.120).β-Ala quadratically increased the plasma concentration of the total antioxidant capacity(P=0.011)and linearly increased the plasma concentration of insulin-like growth factor-1(P<0.001).In summary,dietary supplementation with β-Ala improved the rumen MCP supply and increased the digestibility of DM,OM,CP and the N retention.Further research is necessary to verify the ruminal degradability of β-Ala and to investigate the mech-anism of the impact of absorbed β-Ala on the anti-oxidative ability in steers.
基金supported by National Key R&D Program of China(Grant No.2016YFC0100400)Science and Tech-nology Service network Initiative of Chinese Academy of Sciences(Grant No.KFJ-STS-QYZD-193)+1 种基金Instrument Developing Project of Chinese Academy of Sciences(Grant No.YZ201511)National Natu-ral Science Foundation of China(Grant No.11975250)
文摘Purpose K-edge imaging based on the photon counting detectors(PCDs)is an effective enhanced imaging method because the PCDs are conducive to the K-edge imaging due to the adjustable energy thresholds.The energy bins significantly affect the image quality of the K-edge imaging,but the conventional energy bins used for K-edge imaging are continuous which weaken the K-edge signal and decline the image quality.Hence,how to get a better K-edge signal by the optimized energy bins is the key point for the K-edge imaging based on the PCDs.Method This paper experimentally studied the influence of the energy bins used for the K-edge imaging based on the PCDs.The conventional energy bins were determined by the theoretical-attenuation method(TAM),and the optimized energy bins were determined by the threshold-scan method(TSM).For the phantom and mice imaging,we performed both the K-edge subtraction algorithm and the K-edge decomposition algorithm on the projections obtained by the energy bins which were determined by the TAM and TSM.The image quality was compared using the CNR of the objective area.Results The experimental results showed that the energy bins identified by the TSM had a better performance than the TAM in both imaging methods.The TSM improved the CNR by~39%than the TAM in the phantom results and could better highlight the areas where the contrast agents are enriched(such as the kidney).Conclusions The optimized energy bins can better highlight the K-edge signal than the conventional energy bins which can improve the image quality and have the potential to reduce the amount of the contrast agents.
基金supported by National Natural Science Foundation of China(grant no.32172748)。
文摘The aims of the present study were to investigate the effects of dietary supplementation with rumenprotected taurine(RPT)on the whole-body protein turnover,the plasma metabolomics,and the whole blood cell transcriptomics in steers.Eight steers,averaging 220±3.26 kg of liveweight,were allocated in a replicate 4×4 Latin square design.The experimental treatments consisted of four levels of RPT supplementation:0,25,50,and 75 g RPT per day,added to a basal diet.The results showed that supplementation with RPT linearly decreased the fecal nitrogen(N)excretion(P=0.001)and the 15N fractional recovery rate(P=0.047),while it linearly increased the urinary excretion of taurine(P=0.045)as well as the average daily weight gain(P=0.003),the protein synthesis(P<0.001),the protein degradation(P<0.001)and the whole-body protein turnover(P<0.001).Supplementation with RPT linearly increased the plasma concentrations of growth hormone(P=0.005)and quadratically affected the plasma concentration of insulin-like growth factor-1(P=0.013),and it linearly decreased the plasma concentration of albumin(P=0.022).Supplementation with RPT altered the whole blood cell mRNA expression and upregulated the expressions of the marker genes,including RPS6KB1,PRSS42,COL1A2,ENSBTAG00000013055 and ENSBTAG00000038159 which are related to protein metabolism.The plasma metabolomics profiling indicated that supplementation with RPT upregulated the plasma concentrations of taurine,lysine and methionine.The experiment revealed the impact and the mechanisms of taurine on driving whole-body protein turnover and protein accretion in steers.Two novel marker genes which could be related to body protein degradation in steers were identified.
