Functional brain networks (FBN) based on resting-state functional magnetic resonance imaging (rs-fMRI) have become an important tool for exploring underlying organization patterns in the brain, which can provide an ob...Functional brain networks (FBN) based on resting-state functional magnetic resonance imaging (rs-fMRI) have become an important tool for exploring underlying organization patterns in the brain, which can provide an objective basis for brain disorders such as autistic spectrum disorder (ASD). Due to its importance, researchers have proposed a number of FBN estimation methods. However, most existing methods only model a type of functional connection relationship between brain regions-of-interest (ROIs), such as partial correlation or full correlation, which is difficult to fully capture the subtle connections among ROIs since these connections are extremely complex. Motivated by the multi-view learning, in this study we propose a novel Consistent and Specific Multi-view FBNs Fusion (CSMF) approach. Concretely, we first construct multi-view FBNs (i.e., multiple types of FBNs modelling various relationships among ROIs), and then these FBNs are decomposed into a consistent representation matrix and their own specific matrices which capture their common and unique information, respectively. Lastly, to obtain a better brain representation, it is fusing the consistent and specific representation matrices in the latent representation spaces of FBNs, but not directly fusing the original FBNs. This potentially makes it more easily to find the comprehensively brain connections. The experimental results of ASD identification on the ABIDE datasets validate the effectiveness of our proposed method compared to several state-of-the-art methods. Our proposed CSMF method achieved 72.8% and 76.67% classification performance on the ABIDE dataset.展开更多
Brain functional network (BFN) has become an important tool for the analysis and diagnosis of brain diseases, and how to build a high-quality BFN based on resting-state functional magnetic resonance imaging (rs-fMRI) ...Brain functional network (BFN) has become an important tool for the analysis and diagnosis of brain diseases, and how to build a high-quality BFN based on resting-state functional magnetic resonance imaging (rs-fMRI) has become a growing concern in the neuroscience community. Although some methods have been proposed to construct a high-quality BFN, they only encode the spatial characteristics of the ROIs, ignoring the temporal characteristics. As a result, it becomes challenging to accurately capture the true state of the brain. To address this problem, we propose a novel method to construct a higher-order BFN, considering both temporal and spatial domain characteristics. In particular, we get the characteristics of the temporal domain by differentiating the rs-fMRI signal itself, and then we integrate the information of the spatial domain and temporal domain to build a high-order BFN. To evaluate the proposed method, we conduct our experiments on ABIDE database to identify subjects with Autism Spectrum Disorder (ASD) from normal controls. Experimental results show that our method can achieve higher performance than baseline methods.展开更多
<strong>Objective</strong> To investigate the level of readiness for discharge of patients after prostate cancer surgery based on the concept of Enhanced Recovery After Surgery (ERAS), and to explore its i...<strong>Objective</strong> To investigate the level of readiness for discharge of patients after prostate cancer surgery based on the concept of Enhanced Recovery After Surgery (ERAS), and to explore its influencing factors, so as to provide references for improving the readiness for discharge of patients after prostate cancer surgery. <strong>Methods </strong>The general information questionnaire, the discharge preparation scale, and the discharge guidance quality scale were used to investigate 119 patients discharged from the urological surgery department of a tertiary A-level hospital in Guangzhou after radical prostatectomy. <strong>Results </strong>The total score of discharge readiness of patients after radical prostatectomy was 147.74 ± 35.71 points, which was at a lower middle level and the total score of discharge guidance quality was 180.68 ± 38.91 points, which was at a medium level. Multiple linear regression analysis showed that education level, family monthly income, Gleason score, whether to perform lymphatic dissection, whether to discharge with a urinary catheter, and the quality of discharge guidance were the main factors influencing the readiness for discharge of patients after prostate cancer surgery. <strong>Conclusion </strong>In clinical nursing work, it is necessary to implement individualized health education according to the characteristics and needs of different patients to improve the level of preparation for discharge of patients after prostate cancer surgery.展开更多
A series of catalysts were prepared using the kneading molding method and the impregnation method as well as the dry mix method by using different raw materials. By using X-ray diffraction (XRD), X-ray photoelectron s...A series of catalysts were prepared using the kneading molding method and the impregnation method as well as the dry mix method by using different raw materials. By using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and temperature-programmed reduction (TPR) techniques, we studied the relationship between the catalyst performance and the Cr-Al interaction in the catalytic dehydrogenation of isobutane. The results demonstrated that the Cr-Al interaction in the catalyst had a direct influence on the catalytic activity and the selectivity of isobutene. The catalysts prepared using the kneading molding method had higher catalytic activity and isobutene selectivity than those prepared using the dry mix method. By comparison, XRD, XPS, and TPR results showed that the greater the Cr-Al interaction in the catalyst was, the higher the catalytic activity was. Here, we propose a mechanism of isobutane dehydrogenation.展开更多
[ Objective] The aim was to establish efficient regeneration system of tomato so as to study the genetic transformation of chloroplast in tomato. [ Meth- od] The tomato seeds were sterilized and cultured into plantlet...[ Objective] The aim was to establish efficient regeneration system of tomato so as to study the genetic transformation of chloroplast in tomato. [ Meth- od] The tomato seeds were sterilized and cultured into plantlets. Then, the leaves were cut from plantlets and placed in the MS with 3.0 mg/L 6-BA ＋ 0.3 mg/L IAA to induce callus. Finally, the effect of different hormones and concentrations on induction of adventitious buds from tomato callus and rooting was compared. [Result] The best medium for the induction of differentiation of adventitious buds from callus was： MS ＋ 2.0 mg/L 6-BA ＋ 0.3 mg/L sugar. The best medium for rooting was： 1/2MS ＋ 1.0 mg/L IAA. [ Conclusion] Appropriate sdection of hormone concentrations is the key to establish efficient regeneration system for tomato.展开更多
Semiconductor optical amplifier-based ring cavity laser (SOA-RL), which has been widely used in optical communications, optical fiber sensing, and biophotonics fields, can be tuned at an ultra high speed up to Mega He...Semiconductor optical amplifier-based ring cavity laser (SOA-RL), which has been widely used in optical communications, optical fiber sensing, and biophotonics fields, can be tuned at an ultra high speed up to Mega Hertz over 100 nm bandwidth range with high SNR and flatness output. A steady-state model and segmentation algorithms are employed to investigate the gain spectra of four kinds of non-uniform SOA and the lasing wavelength of the SOA-RL. It shows that the dependence of the lasing wavelength on the average width is stronger when the light propagates from narrower to wider end than conversely, and there are some particular structures to show ultra high stability lasing wavelength. It is supposed that the main reason could be the carrier density distribution along the propagation.展开更多
Experiments and simulations demonstrate that an SOA-based ring cavity can operate as a tunable laser, wavelength- swept laser or Fourier-domain-mode-locking laser according to the relation between the roundtrip freque...Experiments and simulations demonstrate that an SOA-based ring cavity can operate as a tunable laser, wavelength- swept laser or Fourier-domain-mode-locking laser according to the relation between the roundtrip frequency and the sweeping frequency of the filter.展开更多
Functional brain networks (FBNs) provide a potential way for understanding the brain organizational patterns and diagnosing neurological diseases. Due to its importance, many FBN construction methods have been propose...Functional brain networks (FBNs) provide a potential way for understanding the brain organizational patterns and diagnosing neurological diseases. Due to its importance, many FBN construction methods have been proposed currently, including the low-order Pearson’s correlation (PC) and sparse representation (SR), as well as the high-order functional connection (HoFC). However, most existing methods usually ignore the information of topological structures of FBN, such as low-rank structure which can reduce the noise and improve modularity to enhance the stability of networks. In this paper, we propose a novel method for improving the estimated FBNs utilizing matrix factorization (MF). More specifically, we firstly construct FBNs based on three traditional methods, including PC, SR, and HoFC. Then, we reduce the rank of these FBNs via MF model for estimating FBN with low-rank structure. Finally, to evaluate the effectiveness of the proposed method, experiments have been conducted to identify the subjects with mild cognitive impairment (MCI) and autism spectrum disorder (ASD) from norm controls (NCs) using the estimated FBNs. The results on Alzheimer’s Disease Neuroimaging Initiative (ADNI) dataset and Autism Brain Imaging Data Exchange (ABIDE) dataset demonstrate that the classification performances achieved by our proposed method are better than the selected baseline methods.展开更多
Oral colonic nano-drug delivery system has attracted growing attention in treating colon cancer for their excellent characteristics.However,the unique and complex structure of the gastrointestinal tract is still an ob...Oral colonic nano-drug delivery system has attracted growing attention in treating colon cancer for their excellent characteristics.However,the unique and complex structure of the gastrointestinal tract is still an obstacle to the safe delivery of drugs targeting sites in colon tumors.Here,we designed magnetically driven dual-targeted oral colonic nanoparticles loaded with chlorogenic acid using pectin and oleic acid-modified iron oxide(Fe3O4@OA).Specific degradation of pectin by pectinase produced by colonic flora and magnetic fields applied to the colon confers specific targeting of nanoparticles to the colon.In order to overcome the challenge of preparing magnetically driven nanoparticles with small and homogeneous particle sizes by a single conventional method,we developed the combined ultrasound-emulsification technique.The average particle size of the prepared nanoparticles was 81.04±1.02 nm,which showed good drug release in the simulated colonic environment.In vitro anticancer studies,the drug-loaded nanoparticles possess an obvious toxicity and apoptosis-inducing ability against cancer cells.Meanwhile,the hemolysis results demonstrated the safety of the nanoplatform(PET/CGA/Fe_(3)O_(4)@OA).This work holds broad prospects as a new treatment modality for colon cancer.展开更多
The responses of activities, abundances and community structures of soil denitrifiers to mercury （Hg） stress were investigated through a short-term incubation experiment. Four soil treatments with different concentr...The responses of activities, abundances and community structures of soil denitrifiers to mercury （Hg） stress were investigated through a short-term incubation experiment. Four soil treatments with different concentrations of Hg （CK, Hg25, Hg50, and Hg100, denoted as 0, 25, 50, and 100 mg Hg/kg dry soil, respectively） were incubated for 28 days. Soil denitrification enzyme activity （DEA） was measured at day 3, 7 and 28. The abundances and community structures of two denitrification concerning genes, nirS （cd1-nitrite reductase gene） and nosZ （nitrous oxide reductase gene）, were analyzed using real-time PCR and denaturing gradient gel electrophoresis （DGGE）. Results showed that soil DEA was significantly stimulated in the treatments of Hg25 and Hg50 compared with others at day 7. Meanwhile, no difference in the abundances of soil nirS and nosZ was found between Hg spiked treatments and CK, except the lower abundance of nirS （P 〈 0.05） in the Hg added treatments compared with that in the CK at day 28. The community structures of denitrifiers based on nirS gene presented obvious change at day 7 along with the Hg additions, however, no variation was found in all treatments based on the nosZ gene. The results indicated that Hg （Hg25 and Hg50） had a strongly short-term stimulation on soil DEA, and nirS gene is more sensitive than nosZ gene to Hg stress.展开更多
Polylactide(PLA) microspheres were prepared using the solid-in-oil(S/O) spray-drying method to achieve the sustained release of a hydrophilic drug for the treatment of tuberculosis, via intratracheal instillation. Iso...Polylactide(PLA) microspheres were prepared using the solid-in-oil(S/O) spray-drying method to achieve the sustained release of a hydrophilic drug for the treatment of tuberculosis, via intratracheal instillation. Isoniazid(IN), a low-molecular-weight hydrophilic drug, was used as a model drug. The effects of various sizes of micronized IN powder, different drug/polymer ratios, spray-drying process parameters, and drug-release characteristics were studied to optimize the manufacturing parameters. A high entrapment efficiency(87.3%) was obtained using this method; furthermore, the microspheres were spherical and smooth. They were individually and homogenously distributed, with a mean diameter of 5.6 μm; furthermore, they showed a satisfactory extended sustained-release phase. After administration of the microspheres to rats, pulmonary drug concentrations were maintained at a relatively stable level for up to 4 weeks.展开更多
Soil samples were collected from three plots under different land utilization patterns including degradation, farming, and restoration. The abundances of methanotrophs were quantified using real-time polymerase chain ...Soil samples were collected from three plots under different land utilization patterns including degradation, farming, and restoration. The abundances of methanotrophs were quantified using real-time polymerase chain reaction （PCR） based on the pmoA and 16S rRNA genes, and the community fingerprint was analyzed using denaturing gradient gel electrophoresis （DGGE） aiming at pmoA gene. Significantly lower 16S rRNA and pmoA genes copies were found in the degradation treatment than in farming and restoration. Higher abundances of Type I than those of Type II methanotrophs were detected in all treatments, The treatment of farming was clearly separated from degradation and restoration according to the DGGE profile by cluster analysis. The lowest diversity indices were observed in the F （farming plot）, suggesting that the community structure was strongly affected by farming activities. There were significantly positive correlations between the copy numbers of pmoA also Type II-related 16S rRNA genes and soil available K content. Strong negative and positive correlations were found between Type I and soil pH, and available P content, respectively. We concluded that the vegetation cover or not, soil characteristics including pH and nutrients of P and K as a result of anthropogenic disturbance may be key factors affecting methanotrophic communities in upland soil.展开更多
An integrated energy system(IES)is considered to be an important supporting technology for emission reduction because it can effectively improve the efficiency of energy utilization and promote its sustainable develop...An integrated energy system(IES)is considered to be an important supporting technology for emission reduction because it can effectively improve the efficiency of energy utilization and promote its sustainable development.Considering the uncertainties and operational conditions,this paper establishes a bilevel multi-objective optimization model for IES for the Smart Park from the standpoint of economy,technology and environment.The upper level with one objective reflects the economic cost composed of investment,operating and maintenance,etc.The lower level constructs three objectives,including pollution emission,operation costs and renewable energy utilization.Simultaneously,various equality and inequality constraints are addressed to satisfy the technical requirements.In addition,an improved MOEA/D-MC-DC algorithm(Multi Objective Evolutionary Algorithm through Decomposition Based on Monte Carlo and Decoupled Coding,MOEA/D-MC-DC)is presented for handling the complex and nonlinear bilevel multi-objective optimization problems with constraints.A genetic algorithm(GA)is used to solve the upper single objective,while MOEA is employed to cope with the multi-objectives of the lower level.Using three typical IESs in the Smart Park as examples,several simulations are carried out to verify the efficiency,applicability and universality of the proposed model and optimization algorithm.The results show that the proposed method can effectively optimize the configuration of an IES in various Smart Parks.展开更多
Fungi play important roles in ecosystem processes, and the elevational pattern of fungal diversity is still unclear. Here, we examined the diversity of fungi along a 1,000 m elevation gradient on Mount Nadu, Southwest...Fungi play important roles in ecosystem processes, and the elevational pattern of fungal diversity is still unclear. Here, we examined the diversity of fungi along a 1,000 m elevation gradient on Mount Nadu, Southwestern China. We used MiSeq sequencing to obtain fungal sequences that were clustered into operational taxonomic units(OTUs) and to measure the fungal composition and diversity. Though the species richness and phylogenetic diversity of the fungal community did not exhibit significant trends with increasing altitude, they were significantly lower at mid-altitudinal sites than at the base. The Bray-Curtis distance clustering also showed that the fungal communities varied significantly with altitude. A distance-based linear model multivariate analysis(DistLM) identified that soil pH dominated the explanatory power of the species richness(23.72%),phylogenetic diversity(24.25%) and beta diversity(28.10%) of the fungal community. Moreover, the species richness and phylogenetic diversity of the fungal community increased linearly with increasing soil pH(P<0.05). Our study provides evidence that pH is an important predictor of soil fungal diversity along elevation gradients in Southwestern China.展开更多
Soil microbiomes drive the biogeochemical cycling of nitrogen and regulate soil N supply and loss,thus,pivotal nitrogen use efficiency(NUE).Meanwhile,there is an increasing awareness that plant associated microbiomes ...Soil microbiomes drive the biogeochemical cycling of nitrogen and regulate soil N supply and loss,thus,pivotal nitrogen use efficiency(NUE).Meanwhile,there is an increasing awareness that plant associated microbiomes and soil food web interactions is vital for modulating crop productivity and N uptake.The rapid advances in modern omics-based techniques and biotechnologies make it possible to manipulate soil-plant microbiomes for improving NUE and reducing N environmental impacts.This paper summarizes current progress in research on regulating soil microbial N cycle processes for NUE improvement,plant-microbe interactions benefiting plant N uptake,and the importance of soil microbiomes in promoting soil health and crop productivity.We also proposes a potential holistic(rhizosphere-root-phyllosphere)microbe-based approach to improve NUE and reduce dependence on mineral N fertilizer in agroecosystems,toward nature-based solution for nutrient management in intensive cropping systems.展开更多
文摘Functional brain networks (FBN) based on resting-state functional magnetic resonance imaging (rs-fMRI) have become an important tool for exploring underlying organization patterns in the brain, which can provide an objective basis for brain disorders such as autistic spectrum disorder (ASD). Due to its importance, researchers have proposed a number of FBN estimation methods. However, most existing methods only model a type of functional connection relationship between brain regions-of-interest (ROIs), such as partial correlation or full correlation, which is difficult to fully capture the subtle connections among ROIs since these connections are extremely complex. Motivated by the multi-view learning, in this study we propose a novel Consistent and Specific Multi-view FBNs Fusion (CSMF) approach. Concretely, we first construct multi-view FBNs (i.e., multiple types of FBNs modelling various relationships among ROIs), and then these FBNs are decomposed into a consistent representation matrix and their own specific matrices which capture their common and unique information, respectively. Lastly, to obtain a better brain representation, it is fusing the consistent and specific representation matrices in the latent representation spaces of FBNs, but not directly fusing the original FBNs. This potentially makes it more easily to find the comprehensively brain connections. The experimental results of ASD identification on the ABIDE datasets validate the effectiveness of our proposed method compared to several state-of-the-art methods. Our proposed CSMF method achieved 72.8% and 76.67% classification performance on the ABIDE dataset.
文摘Brain functional network (BFN) has become an important tool for the analysis and diagnosis of brain diseases, and how to build a high-quality BFN based on resting-state functional magnetic resonance imaging (rs-fMRI) has become a growing concern in the neuroscience community. Although some methods have been proposed to construct a high-quality BFN, they only encode the spatial characteristics of the ROIs, ignoring the temporal characteristics. As a result, it becomes challenging to accurately capture the true state of the brain. To address this problem, we propose a novel method to construct a higher-order BFN, considering both temporal and spatial domain characteristics. In particular, we get the characteristics of the temporal domain by differentiating the rs-fMRI signal itself, and then we integrate the information of the spatial domain and temporal domain to build a high-order BFN. To evaluate the proposed method, we conduct our experiments on ABIDE database to identify subjects with Autism Spectrum Disorder (ASD) from normal controls. Experimental results show that our method can achieve higher performance than baseline methods.
文摘<strong>Objective</strong> To investigate the level of readiness for discharge of patients after prostate cancer surgery based on the concept of Enhanced Recovery After Surgery (ERAS), and to explore its influencing factors, so as to provide references for improving the readiness for discharge of patients after prostate cancer surgery. <strong>Methods </strong>The general information questionnaire, the discharge preparation scale, and the discharge guidance quality scale were used to investigate 119 patients discharged from the urological surgery department of a tertiary A-level hospital in Guangzhou after radical prostatectomy. <strong>Results </strong>The total score of discharge readiness of patients after radical prostatectomy was 147.74 ± 35.71 points, which was at a lower middle level and the total score of discharge guidance quality was 180.68 ± 38.91 points, which was at a medium level. Multiple linear regression analysis showed that education level, family monthly income, Gleason score, whether to perform lymphatic dissection, whether to discharge with a urinary catheter, and the quality of discharge guidance were the main factors influencing the readiness for discharge of patients after prostate cancer surgery. <strong>Conclusion </strong>In clinical nursing work, it is necessary to implement individualized health education according to the characteristics and needs of different patients to improve the level of preparation for discharge of patients after prostate cancer surgery.
文摘A series of catalysts were prepared using the kneading molding method and the impregnation method as well as the dry mix method by using different raw materials. By using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and temperature-programmed reduction (TPR) techniques, we studied the relationship between the catalyst performance and the Cr-Al interaction in the catalytic dehydrogenation of isobutane. The results demonstrated that the Cr-Al interaction in the catalyst had a direct influence on the catalytic activity and the selectivity of isobutene. The catalysts prepared using the kneading molding method had higher catalytic activity and isobutene selectivity than those prepared using the dry mix method. By comparison, XRD, XPS, and TPR results showed that the greater the Cr-Al interaction in the catalyst was, the higher the catalytic activity was. Here, we propose a mechanism of isobutane dehydrogenation.
文摘[ Objective] The aim was to establish efficient regeneration system of tomato so as to study the genetic transformation of chloroplast in tomato. [ Meth- od] The tomato seeds were sterilized and cultured into plantlets. Then, the leaves were cut from plantlets and placed in the MS with 3.0 mg/L 6-BA ＋ 0.3 mg/L IAA to induce callus. Finally, the effect of different hormones and concentrations on induction of adventitious buds from tomato callus and rooting was compared. [Result] The best medium for the induction of differentiation of adventitious buds from callus was： MS ＋ 2.0 mg/L 6-BA ＋ 0.3 mg/L sugar. The best medium for rooting was： 1/2MS ＋ 1.0 mg/L IAA. [ Conclusion] Appropriate sdection of hormone concentrations is the key to establish efficient regeneration system for tomato.
文摘Semiconductor optical amplifier-based ring cavity laser (SOA-RL), which has been widely used in optical communications, optical fiber sensing, and biophotonics fields, can be tuned at an ultra high speed up to Mega Hertz over 100 nm bandwidth range with high SNR and flatness output. A steady-state model and segmentation algorithms are employed to investigate the gain spectra of four kinds of non-uniform SOA and the lasing wavelength of the SOA-RL. It shows that the dependence of the lasing wavelength on the average width is stronger when the light propagates from narrower to wider end than conversely, and there are some particular structures to show ultra high stability lasing wavelength. It is supposed that the main reason could be the carrier density distribution along the propagation.
文摘Experiments and simulations demonstrate that an SOA-based ring cavity can operate as a tunable laser, wavelength- swept laser or Fourier-domain-mode-locking laser according to the relation between the roundtrip frequency and the sweeping frequency of the filter.
文摘Functional brain networks (FBNs) provide a potential way for understanding the brain organizational patterns and diagnosing neurological diseases. Due to its importance, many FBN construction methods have been proposed currently, including the low-order Pearson’s correlation (PC) and sparse representation (SR), as well as the high-order functional connection (HoFC). However, most existing methods usually ignore the information of topological structures of FBN, such as low-rank structure which can reduce the noise and improve modularity to enhance the stability of networks. In this paper, we propose a novel method for improving the estimated FBNs utilizing matrix factorization (MF). More specifically, we firstly construct FBNs based on three traditional methods, including PC, SR, and HoFC. Then, we reduce the rank of these FBNs via MF model for estimating FBN with low-rank structure. Finally, to evaluate the effectiveness of the proposed method, experiments have been conducted to identify the subjects with mild cognitive impairment (MCI) and autism spectrum disorder (ASD) from norm controls (NCs) using the estimated FBNs. The results on Alzheimer’s Disease Neuroimaging Initiative (ADNI) dataset and Autism Brain Imaging Data Exchange (ABIDE) dataset demonstrate that the classification performances achieved by our proposed method are better than the selected baseline methods.
基金supported by the National Key R&D Program of China(grant No.2019YFB1309703).
文摘Oral colonic nano-drug delivery system has attracted growing attention in treating colon cancer for their excellent characteristics.However,the unique and complex structure of the gastrointestinal tract is still an obstacle to the safe delivery of drugs targeting sites in colon tumors.Here,we designed magnetically driven dual-targeted oral colonic nanoparticles loaded with chlorogenic acid using pectin and oleic acid-modified iron oxide(Fe3O4@OA).Specific degradation of pectin by pectinase produced by colonic flora and magnetic fields applied to the colon confers specific targeting of nanoparticles to the colon.In order to overcome the challenge of preparing magnetically driven nanoparticles with small and homogeneous particle sizes by a single conventional method,we developed the combined ultrasound-emulsification technique.The average particle size of the prepared nanoparticles was 81.04±1.02 nm,which showed good drug release in the simulated colonic environment.In vitro anticancer studies,the drug-loaded nanoparticles possess an obvious toxicity and apoptosis-inducing ability against cancer cells.Meanwhile,the hemolysis results demonstrated the safety of the nanoplatform(PET/CGA/Fe_(3)O_(4)@OA).This work holds broad prospects as a new treatment modality for colon cancer.
基金supported by the Natural Science Foundation of China (No. 41020114001, 50921064)the Ministry of Sciences and Technology (No. 2009AA06Z402,2008ZX07209-006-04)the CAS/SAFEA International Partnership Program for Creative Research Teams of"Ecosystem Processes and Services"
文摘The responses of activities, abundances and community structures of soil denitrifiers to mercury （Hg） stress were investigated through a short-term incubation experiment. Four soil treatments with different concentrations of Hg （CK, Hg25, Hg50, and Hg100, denoted as 0, 25, 50, and 100 mg Hg/kg dry soil, respectively） were incubated for 28 days. Soil denitrification enzyme activity （DEA） was measured at day 3, 7 and 28. The abundances and community structures of two denitrification concerning genes, nirS （cd1-nitrite reductase gene） and nosZ （nitrous oxide reductase gene）, were analyzed using real-time PCR and denaturing gradient gel electrophoresis （DGGE）. Results showed that soil DEA was significantly stimulated in the treatments of Hg25 and Hg50 compared with others at day 7. Meanwhile, no difference in the abundances of soil nirS and nosZ was found between Hg spiked treatments and CK, except the lower abundance of nirS （P 〈 0.05） in the Hg added treatments compared with that in the CK at day 28. The community structures of denitrifiers based on nirS gene presented obvious change at day 7 along with the Hg additions, however, no variation was found in all treatments based on the nosZ gene. The results indicated that Hg （Hg25 and Hg50） had a strongly short-term stimulation on soil DEA, and nirS gene is more sensitive than nosZ gene to Hg stress.
基金supported by the 12th Five-Year Important National Science & Technology Specific Projectsthe National Science & Technology Major Special Project on the Prevention and Cure of Acquired Immune Deficiency Syndrome and Virus Hepatitis (2012ZX10003009-001-002)
文摘Polylactide(PLA) microspheres were prepared using the solid-in-oil(S/O) spray-drying method to achieve the sustained release of a hydrophilic drug for the treatment of tuberculosis, via intratracheal instillation. Isoniazid(IN), a low-molecular-weight hydrophilic drug, was used as a model drug. The effects of various sizes of micronized IN powder, different drug/polymer ratios, spray-drying process parameters, and drug-release characteristics were studied to optimize the manufacturing parameters. A high entrapment efficiency(87.3%) was obtained using this method; furthermore, the microspheres were spherical and smooth. They were individually and homogenously distributed, with a mean diameter of 5.6 μm; furthermore, they showed a satisfactory extended sustained-release phase. After administration of the microspheres to rats, pulmonary drug concentrations were maintained at a relatively stable level for up to 4 weeks.
基金supported by the Knowledge Innovation Program of Chinese Academy of Sciences(No. KSCX2-YW-Z-1020,KZCX2-YW-JC401)the Natural Science Foundation of China(No. 40871129)
文摘Soil samples were collected from three plots under different land utilization patterns including degradation, farming, and restoration. The abundances of methanotrophs were quantified using real-time polymerase chain reaction （PCR） based on the pmoA and 16S rRNA genes, and the community fingerprint was analyzed using denaturing gradient gel electrophoresis （DGGE） aiming at pmoA gene. Significantly lower 16S rRNA and pmoA genes copies were found in the degradation treatment than in farming and restoration. Higher abundances of Type I than those of Type II methanotrophs were detected in all treatments, The treatment of farming was clearly separated from degradation and restoration according to the DGGE profile by cluster analysis. The lowest diversity indices were observed in the F （farming plot）, suggesting that the community structure was strongly affected by farming activities. There were significantly positive correlations between the copy numbers of pmoA also Type II-related 16S rRNA genes and soil available K content. Strong negative and positive correlations were found between Type I and soil pH, and available P content, respectively. We concluded that the vegetation cover or not, soil characteristics including pH and nutrients of P and K as a result of anthropogenic disturbance may be key factors affecting methanotrophic communities in upland soil.
基金supported by the Scientific Research Plan of Beijing Municipal Education Commission(KM202111232022)。
文摘An integrated energy system(IES)is considered to be an important supporting technology for emission reduction because it can effectively improve the efficiency of energy utilization and promote its sustainable development.Considering the uncertainties and operational conditions,this paper establishes a bilevel multi-objective optimization model for IES for the Smart Park from the standpoint of economy,technology and environment.The upper level with one objective reflects the economic cost composed of investment,operating and maintenance,etc.The lower level constructs three objectives,including pollution emission,operation costs and renewable energy utilization.Simultaneously,various equality and inequality constraints are addressed to satisfy the technical requirements.In addition,an improved MOEA/D-MC-DC algorithm(Multi Objective Evolutionary Algorithm through Decomposition Based on Monte Carlo and Decoupled Coding,MOEA/D-MC-DC)is presented for handling the complex and nonlinear bilevel multi-objective optimization problems with constraints.A genetic algorithm(GA)is used to solve the upper single objective,while MOEA is employed to cope with the multi-objectives of the lower level.Using three typical IESs in the Smart Park as examples,several simulations are carried out to verify the efficiency,applicability and universality of the proposed model and optimization algorithm.The results show that the proposed method can effectively optimize the configuration of an IES in various Smart Parks.
基金supported by the National Natural Science Foundation of China(41071039)the Ministry of Science and Technology of China(2012CB417103)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA05060100)
文摘Fungi play important roles in ecosystem processes, and the elevational pattern of fungal diversity is still unclear. Here, we examined the diversity of fungi along a 1,000 m elevation gradient on Mount Nadu, Southwestern China. We used MiSeq sequencing to obtain fungal sequences that were clustered into operational taxonomic units(OTUs) and to measure the fungal composition and diversity. Though the species richness and phylogenetic diversity of the fungal community did not exhibit significant trends with increasing altitude, they were significantly lower at mid-altitudinal sites than at the base. The Bray-Curtis distance clustering also showed that the fungal communities varied significantly with altitude. A distance-based linear model multivariate analysis(DistLM) identified that soil pH dominated the explanatory power of the species richness(23.72%),phylogenetic diversity(24.25%) and beta diversity(28.10%) of the fungal community. Moreover, the species richness and phylogenetic diversity of the fungal community increased linearly with increasing soil pH(P<0.05). Our study provides evidence that pH is an important predictor of soil fungal diversity along elevation gradients in Southwestern China.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA28020101)the National Key Research and Development Program of China(2021YFD1900100)+2 种基金the National Natural Science Foundation of China(51108439 and 42007032)the Natural Science Foundation of Chongqing,China(cstc2014jcyjA20010)the 2115 Talent Development Program of China Agricultural University。
文摘Soil microbiomes drive the biogeochemical cycling of nitrogen and regulate soil N supply and loss,thus,pivotal nitrogen use efficiency(NUE).Meanwhile,there is an increasing awareness that plant associated microbiomes and soil food web interactions is vital for modulating crop productivity and N uptake.The rapid advances in modern omics-based techniques and biotechnologies make it possible to manipulate soil-plant microbiomes for improving NUE and reducing N environmental impacts.This paper summarizes current progress in research on regulating soil microbial N cycle processes for NUE improvement,plant-microbe interactions benefiting plant N uptake,and the importance of soil microbiomes in promoting soil health and crop productivity.We also proposes a potential holistic(rhizosphere-root-phyllosphere)microbe-based approach to improve NUE and reduce dependence on mineral N fertilizer in agroecosystems,toward nature-based solution for nutrient management in intensive cropping systems.
