The issue of low-frequency structural noise radiated from high-speed railway(HSR) box-girder bridges(BGBs) is a significant challenge worldwide. Although it is known that vibrations in BGBs caused by moving trains can...The issue of low-frequency structural noise radiated from high-speed railway(HSR) box-girder bridges(BGBs) is a significant challenge worldwide. Although it is known that vibrations in BGBs caused by moving trains can be reduced by installing multiple tuned mass dampers(MTMDs) on the top plate, there is limited research on the noise reduction achieved by this method. This study aims to investigate the noise reduction mechanism of BGBs installed with MTMDs on the top plate. A sound radiation prediction model for the BGB installed with MTMDs is developed, based on the vehicle–track–bridge coupled dynamics and acoustics boundary element method. After being verified by field tested results, the prediction model is employed to study the reduction of vibration and noise of BGBs caused by the MTMDs. It is found that installing MTMDs on top plate can significantly affect the vibration distribution and sound radiation law of BGBs. However, its impact on the sound radiation caused by vibrations dominated by the global modes of BGBs is minimal. The noise reduction achieved by MTMDs is mainly through changing the acoustic radiation contributions of each plate of the bridge. In the lower frequency range, the noise reduction of BGB caused by MTMDs can be more effective if the installation of MTMDs can modify the vibration frequency and distribution of the BGB to avoid the influence of small vibrations and disperse the sound radiation from each plate.展开更多
This study explores the diagnostic value of combining the Padua score with the thrombotic biomarker tissue plasminogen activator inhibitor-1(tPAI-1)for assessing the risk of deep vein thrombosis(DVT)in patients with p...This study explores the diagnostic value of combining the Padua score with the thrombotic biomarker tissue plasminogen activator inhibitor-1(tPAI-1)for assessing the risk of deep vein thrombosis(DVT)in patients with pulmonary heart disease.These patients often exhibit symptoms similar to venous thrombosis,such as dyspnea and bilateral lower limb swelling,complicating differential diagnosis.The Padua Prediction Score assesses the risk of venous thromboembolism(VTE)in hospitalized patients,while tPAI-1,a key fibrinolytic system inhibitor,indicates a hypercoagulable state.Clinical data from hospitalized patients with cor pulmonale were retrospectively analyzed.ROC curves compared the diagnostic value of the Padua score,tPAI-1 levels,and their combined model for predicting DVT risk.Results showed that tPAI-1 levels were significantly higher in DVT patients compared to non-DVT patients.The Padua score demonstrated a sensitivity of 82.61%and a specificity of 55.26%at a cutoff value of 3.The combined model had a significantly higher AUC than the Padua score alone,indicating better discriminatory ability in diagnosing DVT risk.The combination of the Padua score and tPAI-1 detection significantly improves the accuracy of diagnosing DVT risk in patients with pulmonary heart disease,reducing missed and incorrect diagnoses.This study provides a comprehensive assessment tool for clinicians,enhancing the diagnosis and treatment of patients with cor pulmonale complicated by DVT.Future research should validate these findings in larger samples and explore additional thrombotic biomarkers to optimize the predictive model.展开更多
Adventitious root formation is a bottleneck during vegetative proliferation.Potassium(K^(+))is an essential macronutrient for plants.K^(+)accumulation from the soil and its distribution to the different plant organs i...Adventitious root formation is a bottleneck during vegetative proliferation.Potassium(K^(+))is an essential macronutrient for plants.K^(+)accumulation from the soil and its distribution to the different plant organs is mediated by K^(+)transporters named K^(+)transporter(KT),K^(+)uptake(KUP),or high-affinity K^(+)(HAK).This study aimed to identify members of the HAK gene family in apples and to characterize the effects of K^(+)supply on adventitious root formation and on the expression of HAK genes and the genes that putatively control auxin transport,signaling,and cell fate during adventitious root formation.In this study,34 HAK genes(MdHAKs)were identified in the apple(Malus×domestica‘Golden Delicious’)genome.A phylogenetic analysis divided MdHAKs into four clusters(Ⅰ,Ⅱ,Ⅲ,andⅣ),comprising 16,1,4,and 13 genes,respectively.The syntenic relationships revealed that 62.5%of the total MdHAK genes arise from genomic duplication events.Chromosome location,domain structure,motif analysis,and physico-chemical characteristics were subsequently investigated.Furthermore,the application of K^(+)indicated the emergence of adventitious roots at 8 d and produced more adventitious roots at 16 d than the K^(+)-free control(CK)treatment.In addition,various MdHAKs showed root-specific expression in B9 apple rootstock stem cuttings and enhanced expression during the initiation and emergence stages of adventitious root formation in response to K^(+)treatment.Additionally,K^(+)treatment enhanced the expression levels of MdPIN1,MdPIN2,and MdAUX1.Further data indicated that a higher expression of MdWOX11,MdLBD16,and MdLBD29 and of cell cycle-related genes contributed to the auxin-stimulated adventitious root formation in response to K^(+).展开更多
Objective:To introduce the emergency management of nursing human resources and supplies of a large general hospital when facing the outbreak of coronavirus disease 2019(COVID-19).Method:The Nursing Department of the h...Objective:To introduce the emergency management of nursing human resources and supplies of a large general hospital when facing the outbreak of coronavirus disease 2019(COVID-19).Method:The Nursing Department of the hospital fully executed its functional authority to establish a three-level echelon of sustainable support,allocate human recourses dynamically,organize pre-service training,supervise the key working steps,formulate positive incentive methods,and deploy medical supplies scientifically.Result:By taking these strategies,the hospital effectively improved the coping capacity of the nursing team and played a positive role in the prevention and treatment of COVID-19.Conclusion:The emergency management of nursing human resources and material resources for COVID-19 of the hospital is successful.But several deficiencies were identified as well,which indicated that the hospital needs to establish an efficient emergency management system,and pay attention to the practice of nursing emergency plans to enhance coping capacities in public health emergencies.展开更多
Lateral roots(LRs)are critical for absorbing water,minerals,and nutrients.Nitrate is a vital signaling molecule for regulating LR growth.However,understanding how nitrate interacts with endogenous hormones and genes t...Lateral roots(LRs)are critical for absorbing water,minerals,and nutrients.Nitrate is a vital signaling molecule for regulating LR growth.However,understanding how nitrate interacts with endogenous hormones and genes to coordinate LR development is a bottleneck.In this study,B9 apple rootstock nursery plants were cultured hydroponically and treated with different nitrate treatments(Control;T1,2.25 mM L^(−1);T2,9 mM L^(−1);T3,18 mM L^(−1);T4,36 mM L^(−1);and T5,72 mM L^(−1)),where T5 outperformed the other treatments.Nursery plants were subsequently treated with control and T5 to explore the underlying physiological and molecular mechanisms by which nitrate promoted LR growth.Plant height,stem diameter,root morphological parameters,endogenous hormones,and gene expression levels were measured.Results showed that T5 promoted LR growth by increasing the endogenous contents of indole-3-acetic acid(IAA)and gibberellic acid(GA),and by decreasing the contents of abscisic acid(ABA),jasmonic acid(JA),and zeatin riboside(ZR)at most time points.Furthermore,the relative expression levels of nitrate transporter genes were upregulated in the control group,and nitrate assimilation genes were upregulated in T5 nursery plants at various time points.In addition,the transcript abundances of auxin-related genes were higher in T5 nursery plants,which increased auxin contents.MdSHR,MdGATA1,and MdSCR1 expressions were induced,hence increasing LR growth.In contrast,higher auxin content raised MdWOX11 expression,which enhanced the MdLBD16 and MdLBD29 expression levels,thus prompting the transcripts of cell cycle-related genes:MdCYCD1;1 and MdCYCP4;1.Overall,the changes in hormonal content and gene expression levels followed superior LR growth by T5.展开更多
Seasonal and microhabitat variations of chemical constituents of foliar organic carbon （C）, total nitrogen （N）, total phosphorus （P）, and total potassium （K）, in Populus euphratica growing in desert riparian f...Seasonal and microhabitat variations of chemical constituents of foliar organic carbon （C）, total nitrogen （N）, total phosphorus （P）, and total potassium （K）, in Populus euphratica growing in desert riparian forests in northwestern China and their correlations were studied. Results show that ranges of C, N, P and K contents in the leaves ofP. euphratica were 39.08%-46.16%, 0.28%-2.81%, 0.05%-0.18% and 0.35%-2.03%, with means of 43.51%, 1.49%, 0.102% and 1.17%, respectively. The ratio of C/N, C/P and N/P changed from 16.26 to 146.61, from 258.08 to 908.67 and from 2.89 to 26.67; the mean was 37.24, 466.27 and 15.14, respectively. The mean N content was significantly lower than of deciduous trees in China, but the mean P content was nearly equivalent. The ratio of C/N was remarkably higher than of global land plants. The ratio of N/P indicated that growth ofP. euphratica was jointly limited by N and P nutrient deficiency. During the growth season, total trends of leaf C, N, P and K contents decreased. The max- imum appeared in May, and the minimum in September. Among microhabitats, C, N and K contents gradually increased from ri- parian lowland, flatland, sandpile, Gobi and dune, but C/N ratio was opposite, and P content was not apparent. Foliar C content was extremely, significantly and positively correlated with N and K contents, respectively. The relationships of N-K and P-K were both significantly positive.展开更多
First year of college was found to be the most challenging and stressful year due to the transition from home to school and the adjustment to new life, however, others reported that pre-graduates suffered from more me...First year of college was found to be the most challenging and stressful year due to the transition from home to school and the adjustment to new life, however, others reported that pre-graduates suffered from more mental problems under the pressure of job-hunting and uncertainty of future. This study sought to examine mental health development measured with University Personality Inventory （UPI） among Chinese college students and its relationship with family factors （family income, family residence, and sibling status~） with a longitudinal design. Data of 390 Chinese college students were collected at their first and the third year of college period. The results showed that Chinese college students＇ overall mental health declined in the third year than in the first year. Urban students showed a more rapid increase in physical symptoms from the first year to the third year than rural students. The results indicated that psychological intervention should be extended to students facing graduation, especially those from urban area.展开更多
The drought resistance of eight commonly used apple rootstocks under natural drought conditions was examined to provide clues for the selection,promotion,and utilization of drought-resistant apple rootstocks.The ultra...The drought resistance of eight commonly used apple rootstocks under natural drought conditions was examined to provide clues for the selection,promotion,and utilization of drought-resistant apple rootstocks.The ultrastructural differences and physiological and biochemical characteristics of the leaves of eight apple rootstocks under drought stress were observed.The index changes were used to rank drought resistance by the membership function method comprehensively.The results showed that the leaf thickness,palisade tissue thickness,sponge tissue thickness,net photosynthetic rate,and chlorophyll content were significantly higher in‘Fupingqiuzi'than those of other rootstocks at various stress conditions.The leaf water content and water use efficiency of'Qingzhen 1'were significantly higher than those of other rootstocks under different stress conditions.The root vigor of‘B.9'was significantly higher than that of other rootstocks.The results of membership function analysis showed that the drought resistance of different rootstocks was in the order:‘Fupingqiuzi'>‘Qingzhen 1'>‘B.9'>‘MM.111'>‘GM256'>‘MM.106'>‘M.26'>‘M.9-Nic29'.‘Fupingqiuzi'had the strongest drought resistance,and‘Qingzhen 1'and‘B.9'were also relatively droughtresistant.These rootstocks can be used as raw materials for drought-resistant apple rootstock breeding and are propagated and utilized in arid areas.展开更多
Carbonate rock chemical weathering carbon sinks reduce the rate of increase of the atmospheric CO_(2) concentration and global warming. However, uncertainty still exists in the estimation results of carbonate rock che...Carbonate rock chemical weathering carbon sinks reduce the rate of increase of the atmospheric CO_(2) concentration and global warming. However, uncertainty still exists in the estimation results of carbonate rock chemical weathering carbon sink fluxes(CCSF), and the contributions of climate change and ecological restoration to the CCSF are not clear. To this end, we compiled published site data on ion concentrations in different watersheds in China and used a classical thermodynamic dissolution model to reassess the potential and spatial and temporal patterns of the CCSF in China from 1991 to 2020. We quantified the contributions of temperature(MAT), precipitation(MAP), evapotranspiration(ET), soil water(SM), and the normalized difference vegetation index(NDVI) to the CCSF. The results revealed that(1) China's CCSF was 22.76 t CO_(2)km^(-2)yr^(-1), which was higher than the global average(15.77 t CO_(2)km^(-2)yr^(-1)). The total carbonate rock chemical weathering carbon sink(CCS) was 4772.67×10^(4)t CO_(2), contributing 14.91% of the global CCS through a carbonate rock area of 252.98×10^(4)km^(-2).(2) China's CCSF decreased gradually from southeast to northwest, with values of 33.14, 12.93, and7.27 t CO_(2)km^(-2)yr^(-1)in the southern karst, Qinghai-Tibetan karst, and northern karst regions, respectively.(3) The overall CCSF in China exhibited an increasing trend from 1991 to 2020, with a rate of increase of 0.16 t CO_(2)km^(-2)yr^(-1).(4) The contributions of the MAP, MAT, ET, SM, and NDVI to the CCSF were 63.3%, 3.02%, 27.5%, 3.1%, and 3.05%, respectively. Among them, the increase in precipitation was the main contributor to the increase in the CCSF in China over the last 30 years, while the enhancement of ET offset part of the positive contribution of the increase in precipitation to the CCSF. In conclusion, the results of this study provide a systematic quantification of the magnitude, the patterns, and the influencing factors of CCS over a long time series in China. The results are of great significance and provide a reference for the diagnosis and gap analysis of the national and global carbon neutrality capacities.展开更多
The importance of carbonate weathering carbon sinks(CCSs)is almost equal to that of vegetation photosynthesis in the global carbon cycle.However,CCSs have become controversial in formulating carbon neutral policies to...The importance of carbonate weathering carbon sinks(CCSs)is almost equal to that of vegetation photosynthesis in the global carbon cycle.However,CCSs have become controversial in formulating carbon neutral policies to deal with global climate problems in various countries,since the carbonate dissolution is reversible.In order to address these controversies,we reviewed recent advances in understanding CCSs and examined the outstanding controversies surrounding them.We have analyzed the five controversies,revealing the existence of CCSs,quantifying their magnitude,clarifying their spatiotemporal pattern,and documenting how they have increased and how they evolved under the background of global change.By addressing these five controversies,we help to bring clarity to the role of CCSs in the carbon cycle of global terrestrial ecosystems.展开更多
中国是碳酸盐岩型喀斯特面积最大、分布最广的国家,在喀斯特地区居住着约2亿的人口,经济规模约占全国的10%.尤其是以贵州为中心的西南地区,位于长江和珠江的上游,经济欠发达,但却是国家的重要生态安全屏障.喀斯特地貌重要而特殊,科学诊...中国是碳酸盐岩型喀斯特面积最大、分布最广的国家,在喀斯特地区居住着约2亿的人口,经济规模约占全国的10%.尤其是以贵州为中心的西南地区,位于长江和珠江的上游,经济欠发达,但却是国家的重要生态安全屏障.喀斯特地貌重要而特殊,科学诊断其生态系统的健康不仅对生态修复和实现可持续发展至关重要,更是制定应对方案的基本前提.尽管以往开展了大量的研究工作,但是依然缺乏系统性和整体性认识.本文结合前人研究,进一步将喀斯特地貌演化发育总结为6个阶段:成岩阶段、成陆阶段、成山阶段、成丛阶段、成林阶段和成原阶段.在此基础上,又从碳酸盐岩风化成土速率的计算、土壤水的诊断、水土流失的评价、石漠化解译与演变、生态系统服务的科学计量5个方面进行系统的总结和梳理.尽管不同时代、不同学者的不同研究方法,其结果有着非常大的差异.但是,综合考虑已有的研究结果及其使用方法的优点和不足,归纳发现:(1)碳酸盐岩化学风化很快(30~130 mm ka^(−1)),但由于其酸不溶物含量低(5%以内),导致其成土速率极其缓慢,一般在5~50 t km^(−2)a^(−1)之间.(2)土壤少且分布不连续,但是土壤含水量却比较高,在0.2~0.4 m^(3)m^(−3)之间,这可能与周边基岩的汇水效应相关,且未来呈干化趋势.(3)土壤侵蚀模数低,一般在2~200 t km^(−2)a^(−1)之间,但由于坡陡、降雨量大且与岩土突变接触,导致其侵蚀风险极大,并存在一定比例的地下漏失现象.(4)石漠化的演变可分为单变式、渐进式和返变式3种经典类型,但是通过决策树和人机交互的石漠化解译方法相对高效和精准.(5)喀斯特生态系统服务功能的评价模型要基于成土速率来进行修正水土保持功能和基于岩溶地质碳汇修正气候调节功能.当前诊断喀斯特生态系统健康的指标、方法和模型亟须改进和创新,要充分体现喀斯特地区的特殊性和模型方法的匹配性,提高监测数据的时空分辨率,特别是亟须建立喀斯特社会-生态系统耦合模型,准确刻画出喀斯特生态系统对气候变化和人类活动的响应过程,提升诊断模型的准确度和可预测性.总之,本文系统总结了诊断中国喀斯特生态系统健康与可持续性的方法和取得的重大进展,并进一步从“岩-土-水-石-生”的角度提出了未来的研究方向和突破重点,以期为维护喀斯特地区的生态安全和可持续发展提供科技支撑.展开更多
With the development of modern sequencing techniques and bioinformatics, genomes that were once thought to be noncoding have been found to encode abundant functional micropeptides(miPs), a kind of small polypeptides. ...With the development of modern sequencing techniques and bioinformatics, genomes that were once thought to be noncoding have been found to encode abundant functional micropeptides(miPs), a kind of small polypeptides. Although miPs are difficult to analyze and identify, a number of studies have begun to focus on them. More and more miPs have been revealed as essential for energy metabolism homeostasis, immune regulation, and tumor growth and development. Many reports have shown that miPs are especially essential for regulating glucose and lipid metabolism and regulating mitochondrial function.MiPs are also involved in the progression of related diseases. This paper reviews the sources and identification of miPs, as well as the functional significance of miPs for metabolism-related diseases, with the aim of revealing their potential clinical applications.展开更多
Covalent organic frameworks(COFs)have been increasingly used in capillary electrochromatography due to their excellent characteristics.In this work,hydrazine-linked TFPB-DHzDS(TFPB:1,3,5-tris(4-formylphenyl)benzene;DH...Covalent organic frameworks(COFs)have been increasingly used in capillary electrochromatography due to their excellent characteristics.In this work,hydrazine-linked TFPB-DHzDS(TFPB:1,3,5-tris(4-formylphenyl)benzene;DHzDS:2,5-bis(3-(ethylthio)propoxy)terephthalohydrazide)was first synthesized by a simpler and easier method at room temperature and introduced into capillary electrochromatography as coating material.The TFPB-DHzDS coated capillaries were prepared by an in-situ growth process at room temperature.After optimizing the coating concentration and experimental conditions of capillary electrochromatography,baseline separation of two groups of polycyclic aromatic hydrocarbons was achieved based on the TFPB-DHzDS coated capillary.And the established method was used successfully to determine PAHs in natural water and soil samples.The spiked recoveries of polycyclic aromatic hydrocarbons in these samples ranged from 90.01%to 111.0%,indicating that the method is reliable and could detect polycyclic aromatic hydrocarbons in natural samples.Finally,molecular simulation was applied to study and visualize the interaction between the analytes and coating COF materials to investigate the molecular level separation mechanism further.展开更多
A novel Ni doped carbon quantum dots(Ni-CQDs)fluorescence probe was synthesized by facile electrolysis of monoatomic Ni dispersed porous carbon(Ni–N–C).The obtained Ni-CQDs showed a high quantum yield of 6.3%with th...A novel Ni doped carbon quantum dots(Ni-CQDs)fluorescence probe was synthesized by facile electrolysis of monoatomic Ni dispersed porous carbon(Ni–N–C).The obtained Ni-CQDs showed a high quantum yield of 6.3%with the strongest excitation and emission peaks of 360 nm and 460 nm,and maintained over 90%of the maximum fluorescence intensity in a wide p H range of 3–12.The metal ions detectability of Ni-CQDs was enhanced by Ni doping and functional groups modification,and the rapid and selective detection of Fe^(3+)and Cu^(2+)ions was achieved with Ni-CQDs through dynamic and static quenching mechanism,respectively.On one hand,the energy band gap of Ni-CQDs was regulated by Ni doping,so that excited electrons in Ni-CQDs were able to transfer to Fe^(3+)easily.On the other hand,the abundant functional groups promoted the generation of static quenching complexation between Cu^(2+)and Ni-CQDs.In metal ions detection,the linear quantitation range of Fe^(3+)and Cu^(2+)were 100–1000μM(R^(2)=0.9955)and 300–900μM(R^(2)=0.9978),respectively.The limits of detection(LOD)were calculated as 10.17 and 7.88μM,respectively.Moreover,the fluorescence quenched by Cu^(2+)could be recovered by EDTA2-due to the destruction of the static quenching complexation.In this way,NiCQDs showed the ability to identify the two metal ions to a certain degree under the condition of Fe^(3+)and Cu^(2+)coexistent.This work paves the way of facile multiple metal ion detection with high sensitivity.展开更多
基金supported by the National Natural Science Foundation of China (NSFC) (Grant Nos. 52362049 and 52208446)the Natural Science Foundation of Gansu Province (Grant Nos. 22JR5RA344 and 22JR11RA152)+4 种基金the Special Funds for Guiding Local Scientifi c and Technological Development by the Central Government (Grant No. 22ZY1QA005)the Joint Innovation Fund Project of Lanzhou Jiaotong University and Corresponding Supporting University (Grant No. LH2023016)the Fundamental Research Funds for the Central Universities (2682023ZTZ010), the Lanzhou Science and Technology planning Project (Grant No. 2022-ZD-131)the key Research and Development Project of Lanzhou Jiaotong University (Grant No. LZJTU-ZDYF2302)the University Youth Fund Project of Lanzhou Jiaotong University (Grant No. 2021014)。
文摘The issue of low-frequency structural noise radiated from high-speed railway(HSR) box-girder bridges(BGBs) is a significant challenge worldwide. Although it is known that vibrations in BGBs caused by moving trains can be reduced by installing multiple tuned mass dampers(MTMDs) on the top plate, there is limited research on the noise reduction achieved by this method. This study aims to investigate the noise reduction mechanism of BGBs installed with MTMDs on the top plate. A sound radiation prediction model for the BGB installed with MTMDs is developed, based on the vehicle–track–bridge coupled dynamics and acoustics boundary element method. After being verified by field tested results, the prediction model is employed to study the reduction of vibration and noise of BGBs caused by the MTMDs. It is found that installing MTMDs on top plate can significantly affect the vibration distribution and sound radiation law of BGBs. However, its impact on the sound radiation caused by vibrations dominated by the global modes of BGBs is minimal. The noise reduction achieved by MTMDs is mainly through changing the acoustic radiation contributions of each plate of the bridge. In the lower frequency range, the noise reduction of BGB caused by MTMDs can be more effective if the installation of MTMDs can modify the vibration frequency and distribution of the BGB to avoid the influence of small vibrations and disperse the sound radiation from each plate.
基金Sichuan Province Medical Research Project Plan(Project No.S21113)。
文摘This study explores the diagnostic value of combining the Padua score with the thrombotic biomarker tissue plasminogen activator inhibitor-1(tPAI-1)for assessing the risk of deep vein thrombosis(DVT)in patients with pulmonary heart disease.These patients often exhibit symptoms similar to venous thrombosis,such as dyspnea and bilateral lower limb swelling,complicating differential diagnosis.The Padua Prediction Score assesses the risk of venous thromboembolism(VTE)in hospitalized patients,while tPAI-1,a key fibrinolytic system inhibitor,indicates a hypercoagulable state.Clinical data from hospitalized patients with cor pulmonale were retrospectively analyzed.ROC curves compared the diagnostic value of the Padua score,tPAI-1 levels,and their combined model for predicting DVT risk.Results showed that tPAI-1 levels were significantly higher in DVT patients compared to non-DVT patients.The Padua score demonstrated a sensitivity of 82.61%and a specificity of 55.26%at a cutoff value of 3.The combined model had a significantly higher AUC than the Padua score alone,indicating better discriminatory ability in diagnosing DVT risk.The combination of the Padua score and tPAI-1 detection significantly improves the accuracy of diagnosing DVT risk in patients with pulmonary heart disease,reducing missed and incorrect diagnoses.This study provides a comprehensive assessment tool for clinicians,enhancing the diagnosis and treatment of patients with cor pulmonale complicated by DVT.Future research should validate these findings in larger samples and explore additional thrombotic biomarkers to optimize the predictive model.
基金financially supported by the National Key Research and Development Program of China(Grant No.2018YFD1000101,2019YFD1000803)Shaanxi Apple Industry Science and Technology Project(Grant No.2020zdzx03-01-04)+1 种基金Tang Scholar by Cyrus Tang Foundation(Grant No.C200022002)The China Apple Research System(Grant No.CARS-27).
文摘Adventitious root formation is a bottleneck during vegetative proliferation.Potassium(K^(+))is an essential macronutrient for plants.K^(+)accumulation from the soil and its distribution to the different plant organs is mediated by K^(+)transporters named K^(+)transporter(KT),K^(+)uptake(KUP),or high-affinity K^(+)(HAK).This study aimed to identify members of the HAK gene family in apples and to characterize the effects of K^(+)supply on adventitious root formation and on the expression of HAK genes and the genes that putatively control auxin transport,signaling,and cell fate during adventitious root formation.In this study,34 HAK genes(MdHAKs)were identified in the apple(Malus×domestica‘Golden Delicious’)genome.A phylogenetic analysis divided MdHAKs into four clusters(Ⅰ,Ⅱ,Ⅲ,andⅣ),comprising 16,1,4,and 13 genes,respectively.The syntenic relationships revealed that 62.5%of the total MdHAK genes arise from genomic duplication events.Chromosome location,domain structure,motif analysis,and physico-chemical characteristics were subsequently investigated.Furthermore,the application of K^(+)indicated the emergence of adventitious roots at 8 d and produced more adventitious roots at 16 d than the K^(+)-free control(CK)treatment.In addition,various MdHAKs showed root-specific expression in B9 apple rootstock stem cuttings and enhanced expression during the initiation and emergence stages of adventitious root formation in response to K^(+)treatment.Additionally,K^(+)treatment enhanced the expression levels of MdPIN1,MdPIN2,and MdAUX1.Further data indicated that a higher expression of MdWOX11,MdLBD16,and MdLBD29 and of cell cycle-related genes contributed to the auxin-stimulated adventitious root formation in response to K^(+).
文摘Objective:To introduce the emergency management of nursing human resources and supplies of a large general hospital when facing the outbreak of coronavirus disease 2019(COVID-19).Method:The Nursing Department of the hospital fully executed its functional authority to establish a three-level echelon of sustainable support,allocate human recourses dynamically,organize pre-service training,supervise the key working steps,formulate positive incentive methods,and deploy medical supplies scientifically.Result:By taking these strategies,the hospital effectively improved the coping capacity of the nursing team and played a positive role in the prevention and treatment of COVID-19.Conclusion:The emergency management of nursing human resources and material resources for COVID-19 of the hospital is successful.But several deficiencies were identified as well,which indicated that the hospital needs to establish an efficient emergency management system,and pay attention to the practice of nursing emergency plans to enhance coping capacities in public health emergencies.
基金This work was financially supported by the National Key Research and Development Program of China(2018YFD 1000101,2019YFD1000803)Shaanxi Apple Industry Science and Technology Project(2020zdzx03-01-04)+2 种基金Tang Scholar by Cyrus Tang Foundation(C200022002)The China Apple Research System(CARS-27)Tang Scholar by Cyrus Tang Foundation and Northwest A&F University.
文摘Lateral roots(LRs)are critical for absorbing water,minerals,and nutrients.Nitrate is a vital signaling molecule for regulating LR growth.However,understanding how nitrate interacts with endogenous hormones and genes to coordinate LR development is a bottleneck.In this study,B9 apple rootstock nursery plants were cultured hydroponically and treated with different nitrate treatments(Control;T1,2.25 mM L^(−1);T2,9 mM L^(−1);T3,18 mM L^(−1);T4,36 mM L^(−1);and T5,72 mM L^(−1)),where T5 outperformed the other treatments.Nursery plants were subsequently treated with control and T5 to explore the underlying physiological and molecular mechanisms by which nitrate promoted LR growth.Plant height,stem diameter,root morphological parameters,endogenous hormones,and gene expression levels were measured.Results showed that T5 promoted LR growth by increasing the endogenous contents of indole-3-acetic acid(IAA)and gibberellic acid(GA),and by decreasing the contents of abscisic acid(ABA),jasmonic acid(JA),and zeatin riboside(ZR)at most time points.Furthermore,the relative expression levels of nitrate transporter genes were upregulated in the control group,and nitrate assimilation genes were upregulated in T5 nursery plants at various time points.In addition,the transcript abundances of auxin-related genes were higher in T5 nursery plants,which increased auxin contents.MdSHR,MdGATA1,and MdSCR1 expressions were induced,hence increasing LR growth.In contrast,higher auxin content raised MdWOX11 expression,which enhanced the MdLBD16 and MdLBD29 expression levels,thus prompting the transcripts of cell cycle-related genes:MdCYCD1;1 and MdCYCP4;1.Overall,the changes in hormonal content and gene expression levels followed superior LR growth by T5.
基金supported by the National Natural Science Foundation (40861026,40801001)Major project of the National Natural Science Foundation (91025024)+1 种基金Science and Technology Department Project of Qinghai Province(2010-Z-706,2011-Z-743)the Western Light Project of Chinese Academy of Sciences (2009-14)
文摘Seasonal and microhabitat variations of chemical constituents of foliar organic carbon （C）, total nitrogen （N）, total phosphorus （P）, and total potassium （K）, in Populus euphratica growing in desert riparian forests in northwestern China and their correlations were studied. Results show that ranges of C, N, P and K contents in the leaves ofP. euphratica were 39.08%-46.16%, 0.28%-2.81%, 0.05%-0.18% and 0.35%-2.03%, with means of 43.51%, 1.49%, 0.102% and 1.17%, respectively. The ratio of C/N, C/P and N/P changed from 16.26 to 146.61, from 258.08 to 908.67 and from 2.89 to 26.67; the mean was 37.24, 466.27 and 15.14, respectively. The mean N content was significantly lower than of deciduous trees in China, but the mean P content was nearly equivalent. The ratio of C/N was remarkably higher than of global land plants. The ratio of N/P indicated that growth ofP. euphratica was jointly limited by N and P nutrient deficiency. During the growth season, total trends of leaf C, N, P and K contents decreased. The max- imum appeared in May, and the minimum in September. Among microhabitats, C, N and K contents gradually increased from ri- parian lowland, flatland, sandpile, Gobi and dune, but C/N ratio was opposite, and P content was not apparent. Foliar C content was extremely, significantly and positively correlated with N and K contents, respectively. The relationships of N-K and P-K were both significantly positive.
文摘First year of college was found to be the most challenging and stressful year due to the transition from home to school and the adjustment to new life, however, others reported that pre-graduates suffered from more mental problems under the pressure of job-hunting and uncertainty of future. This study sought to examine mental health development measured with University Personality Inventory （UPI） among Chinese college students and its relationship with family factors （family income, family residence, and sibling status~） with a longitudinal design. Data of 390 Chinese college students were collected at their first and the third year of college period. The results showed that Chinese college students＇ overall mental health declined in the third year than in the first year. Urban students showed a more rapid increase in physical symptoms from the first year to the third year than rural students. The results indicated that psychological intervention should be extended to students facing graduation, especially those from urban area.
基金supported by Shaanxi Apple Industry Science and Technology Project,Grant/Award Number:2020zdzx03-0-04Science and Technology Activity Fund for Returnees Studying Abroad of Shaanxi Province,Grant/Award Number:2020-07Cyrus Tang Foundation and the earmarked fund CARS,Grant/Award Number:CARS-27.
文摘The drought resistance of eight commonly used apple rootstocks under natural drought conditions was examined to provide clues for the selection,promotion,and utilization of drought-resistant apple rootstocks.The ultrastructural differences and physiological and biochemical characteristics of the leaves of eight apple rootstocks under drought stress were observed.The index changes were used to rank drought resistance by the membership function method comprehensively.The results showed that the leaf thickness,palisade tissue thickness,sponge tissue thickness,net photosynthetic rate,and chlorophyll content were significantly higher in‘Fupingqiuzi'than those of other rootstocks at various stress conditions.The leaf water content and water use efficiency of'Qingzhen 1'were significantly higher than those of other rootstocks under different stress conditions.The root vigor of‘B.9'was significantly higher than that of other rootstocks.The results of membership function analysis showed that the drought resistance of different rootstocks was in the order:‘Fupingqiuzi'>‘Qingzhen 1'>‘B.9'>‘MM.111'>‘GM256'>‘MM.106'>‘M.26'>‘M.9-Nic29'.‘Fupingqiuzi'had the strongest drought resistance,and‘Qingzhen 1'and‘B.9'were also relatively droughtresistant.These rootstocks can be used as raw materials for drought-resistant apple rootstock breeding and are propagated and utilized in arid areas.
基金supported by the National Natural Science Foundation(Grant Nos.U22A20619,42077455&42367008)the Western Light Cross-team Program of Chinese Academy of Sciences(Grant No.xbzg-zdsys-202101)+3 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant Nos.XDB40000000&XDA23060100)the Guizhou Provincial Science and Technology Projects(Grant No.2022-198)the High-level Innovative Talents in Guizhou Province(Grant Nos.GCC[2022]015-1&2016-5648)the Guizhou Provincial Science and Technology Subsidies(Grant Nos.GZ2019SIG&GZ2020SIG)。
文摘Carbonate rock chemical weathering carbon sinks reduce the rate of increase of the atmospheric CO_(2) concentration and global warming. However, uncertainty still exists in the estimation results of carbonate rock chemical weathering carbon sink fluxes(CCSF), and the contributions of climate change and ecological restoration to the CCSF are not clear. To this end, we compiled published site data on ion concentrations in different watersheds in China and used a classical thermodynamic dissolution model to reassess the potential and spatial and temporal patterns of the CCSF in China from 1991 to 2020. We quantified the contributions of temperature(MAT), precipitation(MAP), evapotranspiration(ET), soil water(SM), and the normalized difference vegetation index(NDVI) to the CCSF. The results revealed that(1) China's CCSF was 22.76 t CO_(2)km^(-2)yr^(-1), which was higher than the global average(15.77 t CO_(2)km^(-2)yr^(-1)). The total carbonate rock chemical weathering carbon sink(CCS) was 4772.67×10^(4)t CO_(2), contributing 14.91% of the global CCS through a carbonate rock area of 252.98×10^(4)km^(-2).(2) China's CCSF decreased gradually from southeast to northwest, with values of 33.14, 12.93, and7.27 t CO_(2)km^(-2)yr^(-1)in the southern karst, Qinghai-Tibetan karst, and northern karst regions, respectively.(3) The overall CCSF in China exhibited an increasing trend from 1991 to 2020, with a rate of increase of 0.16 t CO_(2)km^(-2)yr^(-1).(4) The contributions of the MAP, MAT, ET, SM, and NDVI to the CCSF were 63.3%, 3.02%, 27.5%, 3.1%, and 3.05%, respectively. Among them, the increase in precipitation was the main contributor to the increase in the CCSF in China over the last 30 years, while the enhancement of ET offset part of the positive contribution of the increase in precipitation to the CCSF. In conclusion, the results of this study provide a systematic quantification of the magnitude, the patterns, and the influencing factors of CCS over a long time series in China. The results are of great significance and provide a reference for the diagnosis and gap analysis of the national and global carbon neutrality capacities.
基金supported by the National Natural Science Foundation of China(Grant Nos.U22A20619,42077455&42367008)the Western Light Cross-team Program of Chinese Academy of Sciences(Grant No.xbzg-zdsys-202101)+4 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant Nos.XDB40000000)the Guizhou Provincial Science and Technology Project(Grant Nos.Qiankehe Support[2024]Key 014,Qiankehe Support[2022]Key 010,Qiankehe Support[2023]General 219&Qiankehe Support ZK(2021)-192)the High-level Innovative Talents in Guizhou Province(Grant No.GCC[2022]015-1)the Opening Fund of the State Key Laboratory of Environmental Geochemistry(Grant No.SKLEG2024202)the Guizhou Provincial Science and Technology Subsidies(Grant Nos.GZ2019SIG&GZ2020SIG)。
文摘The importance of carbonate weathering carbon sinks(CCSs)is almost equal to that of vegetation photosynthesis in the global carbon cycle.However,CCSs have become controversial in formulating carbon neutral policies to deal with global climate problems in various countries,since the carbonate dissolution is reversible.In order to address these controversies,we reviewed recent advances in understanding CCSs and examined the outstanding controversies surrounding them.We have analyzed the five controversies,revealing the existence of CCSs,quantifying their magnitude,clarifying their spatiotemporal pattern,and documenting how they have increased and how they evolved under the background of global change.By addressing these five controversies,we help to bring clarity to the role of CCSs in the carbon cycle of global terrestrial ecosystems.
文摘中国是碳酸盐岩型喀斯特面积最大、分布最广的国家,在喀斯特地区居住着约2亿的人口,经济规模约占全国的10%.尤其是以贵州为中心的西南地区,位于长江和珠江的上游,经济欠发达,但却是国家的重要生态安全屏障.喀斯特地貌重要而特殊,科学诊断其生态系统的健康不仅对生态修复和实现可持续发展至关重要,更是制定应对方案的基本前提.尽管以往开展了大量的研究工作,但是依然缺乏系统性和整体性认识.本文结合前人研究,进一步将喀斯特地貌演化发育总结为6个阶段:成岩阶段、成陆阶段、成山阶段、成丛阶段、成林阶段和成原阶段.在此基础上,又从碳酸盐岩风化成土速率的计算、土壤水的诊断、水土流失的评价、石漠化解译与演变、生态系统服务的科学计量5个方面进行系统的总结和梳理.尽管不同时代、不同学者的不同研究方法,其结果有着非常大的差异.但是,综合考虑已有的研究结果及其使用方法的优点和不足,归纳发现:(1)碳酸盐岩化学风化很快(30~130 mm ka^(−1)),但由于其酸不溶物含量低(5%以内),导致其成土速率极其缓慢,一般在5~50 t km^(−2)a^(−1)之间.(2)土壤少且分布不连续,但是土壤含水量却比较高,在0.2~0.4 m^(3)m^(−3)之间,这可能与周边基岩的汇水效应相关,且未来呈干化趋势.(3)土壤侵蚀模数低,一般在2~200 t km^(−2)a^(−1)之间,但由于坡陡、降雨量大且与岩土突变接触,导致其侵蚀风险极大,并存在一定比例的地下漏失现象.(4)石漠化的演变可分为单变式、渐进式和返变式3种经典类型,但是通过决策树和人机交互的石漠化解译方法相对高效和精准.(5)喀斯特生态系统服务功能的评价模型要基于成土速率来进行修正水土保持功能和基于岩溶地质碳汇修正气候调节功能.当前诊断喀斯特生态系统健康的指标、方法和模型亟须改进和创新,要充分体现喀斯特地区的特殊性和模型方法的匹配性,提高监测数据的时空分辨率,特别是亟须建立喀斯特社会-生态系统耦合模型,准确刻画出喀斯特生态系统对气候变化和人类活动的响应过程,提升诊断模型的准确度和可预测性.总之,本文系统总结了诊断中国喀斯特生态系统健康与可持续性的方法和取得的重大进展,并进一步从“岩-土-水-石-生”的角度提出了未来的研究方向和突破重点,以期为维护喀斯特地区的生态安全和可持续发展提供科技支撑.
基金supported by the National Natural Science Foundation of China(No.81870237)。
文摘With the development of modern sequencing techniques and bioinformatics, genomes that were once thought to be noncoding have been found to encode abundant functional micropeptides(miPs), a kind of small polypeptides. Although miPs are difficult to analyze and identify, a number of studies have begun to focus on them. More and more miPs have been revealed as essential for energy metabolism homeostasis, immune regulation, and tumor growth and development. Many reports have shown that miPs are especially essential for regulating glucose and lipid metabolism and regulating mitochondrial function.MiPs are also involved in the progression of related diseases. This paper reviews the sources and identification of miPs, as well as the functional significance of miPs for metabolism-related diseases, with the aim of revealing their potential clinical applications.
基金the National Natural Science Foundation of China(Grant Nos.21705064,21675068)for financial support.
文摘Covalent organic frameworks(COFs)have been increasingly used in capillary electrochromatography due to their excellent characteristics.In this work,hydrazine-linked TFPB-DHzDS(TFPB:1,3,5-tris(4-formylphenyl)benzene;DHzDS:2,5-bis(3-(ethylthio)propoxy)terephthalohydrazide)was first synthesized by a simpler and easier method at room temperature and introduced into capillary electrochromatography as coating material.The TFPB-DHzDS coated capillaries were prepared by an in-situ growth process at room temperature.After optimizing the coating concentration and experimental conditions of capillary electrochromatography,baseline separation of two groups of polycyclic aromatic hydrocarbons was achieved based on the TFPB-DHzDS coated capillary.And the established method was used successfully to determine PAHs in natural water and soil samples.The spiked recoveries of polycyclic aromatic hydrocarbons in these samples ranged from 90.01%to 111.0%,indicating that the method is reliable and could detect polycyclic aromatic hydrocarbons in natural samples.Finally,molecular simulation was applied to study and visualize the interaction between the analytes and coating COF materials to investigate the molecular level separation mechanism further.
基金the National Natural Science Foundation of China(Nos.21776302 and 21776308)the Science Foundation of China University of Petroleum,Beijing(No.2462020YXZZ033)。
文摘A novel Ni doped carbon quantum dots(Ni-CQDs)fluorescence probe was synthesized by facile electrolysis of monoatomic Ni dispersed porous carbon(Ni–N–C).The obtained Ni-CQDs showed a high quantum yield of 6.3%with the strongest excitation and emission peaks of 360 nm and 460 nm,and maintained over 90%of the maximum fluorescence intensity in a wide p H range of 3–12.The metal ions detectability of Ni-CQDs was enhanced by Ni doping and functional groups modification,and the rapid and selective detection of Fe^(3+)and Cu^(2+)ions was achieved with Ni-CQDs through dynamic and static quenching mechanism,respectively.On one hand,the energy band gap of Ni-CQDs was regulated by Ni doping,so that excited electrons in Ni-CQDs were able to transfer to Fe^(3+)easily.On the other hand,the abundant functional groups promoted the generation of static quenching complexation between Cu^(2+)and Ni-CQDs.In metal ions detection,the linear quantitation range of Fe^(3+)and Cu^(2+)were 100–1000μM(R^(2)=0.9955)and 300–900μM(R^(2)=0.9978),respectively.The limits of detection(LOD)were calculated as 10.17 and 7.88μM,respectively.Moreover,the fluorescence quenched by Cu^(2+)could be recovered by EDTA2-due to the destruction of the static quenching complexation.In this way,NiCQDs showed the ability to identify the two metal ions to a certain degree under the condition of Fe^(3+)and Cu^(2+)coexistent.This work paves the way of facile multiple metal ion detection with high sensitivity.
