Parkinson’s disease manifests in movement disorder symptoms, such as hand tremor. There exists an assortment of therapy interventions. In particular deep brain stimulation offers considerable efficacy for the treatme...Parkinson’s disease manifests in movement disorder symptoms, such as hand tremor. There exists an assortment of therapy interventions. In particular deep brain stimulation offers considerable efficacy for the treatment of Parkinson’s disease. However, a considerable challenge is the convergence toward an optimal configuration of tuning parameters. Quantified feedback from a wearable and wireless system consisting of an accelerometer and gyroscope can be enabled through a novel software application on a smartphone. The smartphone with its internal accelerometer and gyroscope can record the quantified attributes of Parkinson’s disease and tremor through mounting the smartphone about the dorsum of the hand. The recorded data can be then wirelessly transmitted as an email attachment to an Internet derived resource for subsequent post-processing. The inertial sensor data can be consolidated into a feature set for machine learning classification. A multilayer perceptron neural network has been successfully applied to attain considerable classification accuracy between deep brain stimulation “On” and “Off” scenarios for a subject with Parkinson’s disease. The findings establish the foundation for the broad objective of applying wearable and wireless systems for the development of closed-loop optimization of deep brain stimulation parameters in the context of cloud computing with machine learning classification.展开更多
Lithium-ion batteries(LIBs) are considered new generation of large-scale energy-storage devices.However,LIBs suffer from a lack of desirable anode materials with excellent specific capacity and cycling stability.In th...Lithium-ion batteries(LIBs) are considered new generation of large-scale energy-storage devices.However,LIBs suffer from a lack of desirable anode materials with excellent specific capacity and cycling stability.In this work,we design a novel hierarchical structure constructed by encapsulating cobalt sulfide nanowires within nitrogen-doped porous branched carbon nanotubes(NBNTs)for LIBs.The unique hierarchical Co9S8@NBNT electrode displayed a reversible specific capacity of 1310 mAhg-1 at a current density of 0.1 Ag-1,and was able to maintain a stable reversible discharge capacity of 1109 mAhg-1 at a current density of 0.5 Ag-1 with coulombic efficiency reaching almost 100% for 200 cycles.The excellent rate and cycling capabilities can be ascribed to the hierarchical porosity of the one-dimensional Co9S8@NBNT internetworks,the incorporation of nitrogen doping,and the carbon nanotube confinement of the active cobalt sulfide nanowires offering a proximate electron pathway for the isolated nanoparticles and shielding of the cobalt sulfide nanowires from pulverization over long cycling periods.展开更多
The multiple sensing provides booming options to eliminate interference and ensure the accuracy of detection by mutually coupling and validating multiple data sets.Here,we integrate the jigsaw-like multifunctional min...The multiple sensing provides booming options to eliminate interference and ensure the accuracy of detection by mutually coupling and validating multiple data sets.Here,we integrate the jigsaw-like multifunctional mini-pillar platform to perform multi-mode(electrochemical,fluorescence,surface-enhanced Raman scattering(SERS)and colorimetric)sensing in individual microdroplets.Each mini-pillar connector can parallelize together by specific concave-convex interface to form integrated jigsaw-like platform for multi-mode sensing,and each specific mini-pillar can be modified into the individual sensing unit to read the prescribed signals.We successfully implemented electrochemical,fluorescence,SERS and colorimetric detection by multiple signals coupling to reduce the false positive analysis.Such platform brings a promising clue of in-situ analysis and point-of-care testing for disease diagnosis and health monitoring.展开更多
Light plays an important role in the photosynthesis and metabolic process of microalgae.However,how different light conditions regulate the biomass production and protein accumulation of microalgae is mostly unknown.I...Light plays an important role in the photosynthesis and metabolic process of microalgae.However,how different light conditions regulate the biomass production and protein accumulation of microalgae is mostly unknown.In this study,the influence of different light conditions,including light colors,densities,and light:dark cycles on the cell growth and biochemical composition of Spirulina platensis was symmetrically characterized.Under different colored lights,S.platensis all shows an increase trend within the increased light intensity ranges;however,each showing different optimal light intensities.At the same light intensity,different colored lights show different growth rate of S.platensis following the sequence of red>white>green>yellow>blue.The maximum growth rate and protein accumulation were determined as 21.88 and 5.10 mg/(L·d)when illuminated under red LED.The energy efficiency of different light sources was calculated and ranked as red>white>blue≈green>yellow.Transcriptomic analysis suggests that red light can promote cell growth and protein accumulation by upregulating genes related to photosynthesis,carbon fixation,and C-N metabolism pathways.This study provides a conducive and efficient way to promote biomass production and protein accumulation of S.platensis by regulating light conditions.展开更多
Nanostructures self-assembled by cross-β peptides with ordered structures and advantageous mechanical properties have many potential applications in biomaterials and nanotechnologies. Quantifying the intra-and inter-...Nanostructures self-assembled by cross-β peptides with ordered structures and advantageous mechanical properties have many potential applications in biomaterials and nanotechnologies. Quantifying the intra-and inter-molecular driving forces for peptide self-assembly at the atomistic level is essential for understanding the formation mechanism and nanomechanics of various morphologies of self-assembled peptides. We investigate the thermodynamics of the intra-and inter-sheet structure formations in the self-assembly process of cross-β peptide KⅢIK by means of steered molecular dynamics simulation combined with umbrella sampling. It is found that the mechanical properties of the intra-and inter-sheet structures are highly anisotropic with their intermolecular bond stiffness at the temperature of 300 K being 5.58 N/m and 0.32 N/m, respectively. This mechanical anisotropy comes from the fact that the intra-sheet structure is stabilized by enthalpy but the inter-sheet structure is stabilized by entropy. Moreover, the formation process of KⅢIK intra-sheet structure is cooperatively driven by the van der Waals （VDW） interaction between the hydrophobic side chains and the electrostatic interaction between the hydrophilic backbones, but that of the inter-sheet structure is primarily driven by the VDW interaction between the hydrophobic side chains. Although only peptide KⅢIK is studied, the qualitative conclusions on the formation mechanism should also apply to other cross-β peptides.展开更多
3D microgels with various mechanical properties have been important platforms tumor metastasis analysis,and widely adjustable stiffness is crucial for deeper researches.Herein,by mixing biodegradable polylactic acid(P...3D microgels with various mechanical properties have been important platforms tumor metastasis analysis,and widely adjustable stiffness is crucial for deeper researches.Herein,by mixing biodegradable polylactic acid(PLA)nanofibers in the modified alginate with different concentrations of Ca^(2+),we significantly enhance the stiffness range of microgels while retaining the pore size,which provides bionic microenvironment for tumor analysis.As a proof of concept,we simulated the mechanical characteristics of breast tumors by encapsulating cells in 3D microgels with diverse stiffness,and analyzed cellular behaviors of two typical breast cancer cell lines:MCF-7 and SUM-159.Results showed that with the addition of 2.0%(w/v)PLA short nanofibers,the Young’s modulus of modified alginate increased more than three-fold.Besides preserving high survival and proliferation rates,both cells also displayed stronger migration ability in soft microgel spheres,where RT-qPCR analysis revealed the underlying changes at the genetic level.This systematic study demonstrated our method is powerful for creating widely adjustable 3D mechanical microenvironment,and the results of cellular behavior analysis shows its promising application prospects in tumorigenesis and progression.展开更多
In this article,the legend for Fig.3 f&g was inadvertently mislabeled.The figure below shows the wrong one.The figure should have appeared as shown below.
This study is focused on investigation of biofilms formed in an anaerobic laboratory-scale bioreactor fed with medium for anammox bacteria oxidizing ammonia with nitrite. The mixed culture of anammox bacteria was enri...This study is focused on investigation of biofilms formed in an anaerobic laboratory-scale bioreactor fed with medium for anammox bacteria oxidizing ammonia with nitrite. The mixed culture of anammox bacteria was enriched from the microbial community that sampled from the activated sludge of a denitrifying reactor at a wastewater treatment station located in the Sochi region, Russia. This community forms biofilms on the surface of the flexible polymer brush carriers, which are used for biomass immobilization in both laboratory and full-scale bioreactors. Anammox bacteria were discovered in the activated sludge community. The anammox community was enriched by incubation in an up-flow laboratory-scale anaerobic bioreactor with a flexible brush carrier. In the course of ~3 years, the loading rate of nitrogen substrates (ammonium and nitrite) increased from 100 to 5000 mg N L-1 day-1. The concentration of the substrates in the upper part of the reactor was 40 times less than in the influent. The pH values were 7.5 at the bottom and up to 9 in the upper part up of the reactor. Biofilms of two types developed in the reactor. Bunches of irregular spherical granules formed on the carrier filaments, while films of irregular thickness containing submerged spherical granules were formed on the walls of reactor. The anammox population was found to consist of at least three active species: a new strain of Candidatus “Jettenia asiatica” named “strain ecos” and two species of the genus Candidatus “Brocadia”. Other types of bacteria found in the community, including members of phylum Chloroflexi, were presumably involved in biofilm spatial organization.展开更多
Regeneration of damaged retinal ganglion cells（RGC） and their axons is an important aspect of reversing vision loss in glaucoma patients. While current therapies can effectively lower intraocular pressure, they do n...Regeneration of damaged retinal ganglion cells（RGC） and their axons is an important aspect of reversing vision loss in glaucoma patients. While current therapies can effectively lower intraocular pressure, they do not provide extrinsic support to RGCs to actively aid in their protection and regeneration. The unmet need could be addressed by neurotrophic factor gene therapy, where plasmid DNA, encoding neurotrophic factors, is delivered to retinal cells to maintain sufficient levels of neurotrophins in the retina. In this review, we aim to describe the intricacies in the design of the therapy including： the choice of neurotrophic factor, the site and route of administration and target cell populations for gene delivery. Furthermore, we also discuss the challenges currently being faced in RGC-related therapy development with special considerations to the existence of multiple RGC subtypes and the lack of efficient and representative in vitro models for rapid and reliable screening in the drug development process.展开更多
In the present study, transplantation of bone marrow-derived mesenchymal stem cells modified with brain-derived neurotrophic factor gene into the lateral ventricle of a rat model of Alzheimer＇s disease, resulted in s...In the present study, transplantation of bone marrow-derived mesenchymal stem cells modified with brain-derived neurotrophic factor gene into the lateral ventricle of a rat model of Alzheimer＇s disease, resulted in significant attenuation of nerve cell damage in the hippocampal CA1 region. Furthermore, brain-derived neurotrophic factor and tyrosine kinase B mRNA and protein levels were significantly increased, and learning and memory were significantly improved. Results indicate that transplantation of bone marrow-derived mesenchymal stem cells modified with brain-derived neurotrophic factor gene can significantly improve cognitive function in a rat model of Alzheimer＇s disease, possibly by increasing the levels of brain-derived neurotrophic factor and tyrosine kinase B in the hippocampus.展开更多
Researches on detection of human papillomavirus(HPV)high-risk samples were carried out by polymerase chain reaction(PCR)coupled with microchip electrophoresis(MCE).Herein,we introduced a simple,rapid,automated method ...Researches on detection of human papillomavirus(HPV)high-risk samples were carried out by polymerase chain reaction(PCR)coupled with microchip electrophoresis(MCE).Herein,we introduced a simple,rapid,automated method for detecting high-risk samples HPV16 and HPV18.In this research,general primers were initially selected to obtain sufficient detectable yield by PCR to verify feasibility of MCM method for HPV detection,then type-specific primers were further used to evaluate the specificity of MCE method.The results indicated MCE method was capable of specifically detecting high-risk HPV16 and HPV18,and also enabled simultaneous detection of multiplex samples.This MCE method described here has been successfully applied to HPV detection and displayed excellent reliability demonstrating by sequencing results.The inherent capability of MCE facilitated HPV detection conducted in a small chip with automated,high throughput,massive parallelized analysis.We envision that MCE method will definitely pave a way for clinical diagnosis,and even on-site screening of cervical cancer.展开更多
The peculiar attributes of muscles that are stretched when active have been noted for nearly a century.Understandably,the focus of muscle physiology has been primarily on shortening and isometric contractions,as eloqu...The peculiar attributes of muscles that are stretched when active have been noted for nearly a century.Understandably,the focus of muscle physiology has been primarily on shortening and isometric contractions,as eloquently revealed by A.V.Hill and subsequently by his students.When the sliding filament theory was introduced by A.F.Huxley and H.E.Huxley,it was a relatively simple task to link Hill's mechanical observations to the actions of the cross bridges during these shortening and isometric contractions.In contrast,lengthening or eccentric contractions have remained somewhat enigmatic.Dismissed as necessarily causing muscle damage,eccentric contractions have been much more difficult to fit into the cross-bridge theory.The relatively recent discovery of the giant elastic sarcomeric filament titin has thrust a previously missing element into any discussion of muscle function,in particular during active stretch.Indeed,the unexpected contribution of giant elastic proteins to muscle contractile function is highlighted by recent discoveries that twitchin-actin interactions are responsible for the"catch"property of invertebrate muscle.In this review,we examine several current theories that have been proposed to account for the properties of muscle during eccentric contraction.We ask how well each of these explains existing data and how an elastic filament can be incorporated into the sliding filament model.Finally,we review the increasing body of evidence for the benefits of including eccentric contractions into a program of muscle rehabilitation and strengthening.展开更多
Allium senescens,is an important economic and ecological grassland plant with drought-resistant characteristics.A TCP protein transcription factor is important in the regulation of plant development and adverse respon...Allium senescens,is an important economic and ecological grassland plant with drought-resistant characteristics.A TCP protein transcription factor is important in the regulation of plant development and adverse responses.However,the mechanism by which TCP transcription functions in drought resistance in Allium senescens is still not clear.Here,we obtained a total of 190,305 transcripts with 115,562 single gene clusters based on RNA-Seq sequencing of Allium senescens under drought stress.The total number of bases was 97,195,096 bp,and the average length was 841.06 bp.Furthermore,we found that there were eight genes of the TCP family that showed an upregulated expression trend under drought stress in Allium senescens.We carried out an investigation to determine the evolution and function of the AsTCP family and how they produce an effect in drought resistance.The 14 AsTCP genes were confirmed and divided into class I and class II containing CIN and CYC/TBI subfamilies,respectively.We also found that the expression of AsTCP17 was remarkably upregulated with drought treatment.Besides,the transformation of AsTCP17 in Arabidopsis revealed that the protective enzymes,namely polyphenol oxidase(POD)and superoxide dismutase(SOD),were increased by 0.4 and 0.8 times,respectively.Chlorophyll content was also increased,while the H2O2 and malondialdehyde(MDA)contents were decreased.Staining assays with 3,3′-diaminobenzidine(DAB)also suggested that the AsTCP17 downregulates reactive oxygen species(ROS)accumulation.In addition,overexpression of the AsTCP17 affected the accumulation of drought-related hormones in plants,and the synthesis of ABA.The expression of AtSVP and AtNCED3,related ABA synthesis pathway genes,indicated that the level of expression of AtSVP and AtNCED3 was obviously enhanced,with the overexpression of line 6 showing a 20.6-fold and 7.0-fold increase,respectively.Taken together,our findings systematically analyze the AsTCPs family at the transcriptome expression level in Allium senescens,and we also demonstrated that AsTCP17 protein,as a positive regulator,was involved in drought resistance of Allium senescens.In addition,our research contributes to the comprehensive understanding of the drought stress defense mechanism in herbaceous plants.展开更多
AIM： To investigate the flow and mixing at the duodenal stump after gastric resection, a computer simulation was implemented. METHODS： Using the finite element method, two different Billroth fl procedure cases （A a...AIM： To investigate the flow and mixing at the duodenal stump after gastric resection, a computer simulation was implemented. METHODS： Using the finite element method, two different Billroth fl procedure cases （A and B） were modeled. Case A was defined with a shorter and almost straight duodenal section, while case B has a much longer and curved duodenal section. Velocity, pressure and food concentration distribution were determined and the numerical results were compared with experimental observations. RESULTS： The pressure distribution obtained by numerical simulation was in the range of the recorded experimental results. Case A had a more favorable pressure distribution in comparison with case B. However, case B had better performance in terms of food transport because of more continual food distribution, as well as better emptying of the duodena section. CONCLUSION： This study offers insight into the transport process within the duodenal stump section after surgical intervention, which can be useful for future patient-specific predictions of a surgical outcome.展开更多
Porous Ti with low modulus,excellent bio-corrosion resistance,biocompatibility,and antibacterial activity is highly pursued as advanced implant materials.In this work,a new approach to prepare micron porous structures...Porous Ti with low modulus,excellent bio-corrosion resistance,biocompatibility,and antibacterial activity is highly pursued as advanced implant materials.In this work,a new approach to prepare micron porous structures on the surface layer of a grade 2 commercially-pure Ti(TA2)was proposed,which utilized a simple vacuum wetting process of pure Ag on the surface of TA2.The microstructure,corrosion resistance,biocompatibility,mechanical properties,antibacterial ability,and formation mechanism of the asfabricated porous Ti were studied.The results show that the pores(with average pore sizes of 0.5-5μm)are distributed on the surface layer of the TA2 with a depth of~10μm.In particular,a large number of silver nanoparticles(Ag NPs)form which are dispersed on the porous structures.The formation mechanisms of the porous structures and Ag NPs were elucidated,suggesting that the volatilization/sublimation of Ag in TA2 is crucial.The porous Ti possesses excellent bio-corrosion resistance,surface wettability,biocompatibility,antibacterial activity,and a relatively low elastic modulus of 40-55 GPa,which may have a promising future in the field of orthopedic implants.This work also provides a novel idea for the development of advanced porous Ti materials for orthopedic-related basic research and biomedical applications.展开更多
Black fungus derived carbonaceous aerogel (BFA) was prepared via a convenient and energy efficient ultrasonic disposal process. The adsorption experiments of atmospheric pollutants demonstrated the superior adsorbabil...Black fungus derived carbonaceous aerogel (BFA) was prepared via a convenient and energy efficient ultrasonic disposal process. The adsorption experiments of atmospheric pollutants demonstrated the superior adsorbability of black fungus aerogel on PM2.5, PM10 and formaldehyde. More importantly, black fungus aerogel (BFA) exhibited intriguing double-faced properties. We explored properties of each side of the black fungus from three aspects: water contact angle measurements, liquid selective absorption capacity and air pollutant adsorption abilities. The subsequent modification of ZnO nanosheets endowed the prepared black fungus aerogel with several valuable properties, including broad-spectrum antibacterial capability and high-efficient adsorption ability. These valuable characters implied the BFA to be a promising bacteriostat and cleaner for air and water pollution treatment.展开更多
Conventional filling therapy fails to fundamentally reduce oral cariogenic bacteria.Thus,oral microbiota follow-up intervention after filling would be necessary for improving dental caries prognosis.We recruited 9 car...Conventional filling therapy fails to fundamentally reduce oral cariogenic bacteria.Thus,oral microbiota follow-up intervention after filling would be necessary for improving dental caries prognosis.We recruited 9 caries-free individuals,and 89 dental caries subjects(5 dropouts).Eighty-nine patients were randomized into three groups:caries(n=8;no treatment),control(n=40;filling),and postbiotics(n=41;filling and 14-day Probio-Eco®intervention).Salivary samples were collected at 0 day(after filling)and 14 days.Our results showed that the diversity of dental caries oral microbiota was significantly increased compared with healthy subjects,and filling could restore a healthier oral microbiota partially and temporarily.Thepostbiotics intervention keeps a low alpha-diversity.Co-occurrence network analysis showed that a more stable oral microbiota structure after postbiotics intervention.Taxonomic and functional annotation of the microbiota revealed that postbiotics co-treatment significantly:increased the relative abundance of Pseudomonas and P.reactans,decreased the relative abundance of Prevotella shahii,and enriched the energy metabolism-related pathways.BugBase-predicted phenotypes inferred to an oral microbiota with decreased potential pathogenic bacteria and increased oxidative stress-tolerant bacteria after postbiotics intervention.Collectively,it suggested that postbiotics co-treatment could be a promising strategy that restores the oral microecological balance for dental caries.展开更多
文摘Parkinson’s disease manifests in movement disorder symptoms, such as hand tremor. There exists an assortment of therapy interventions. In particular deep brain stimulation offers considerable efficacy for the treatment of Parkinson’s disease. However, a considerable challenge is the convergence toward an optimal configuration of tuning parameters. Quantified feedback from a wearable and wireless system consisting of an accelerometer and gyroscope can be enabled through a novel software application on a smartphone. The smartphone with its internal accelerometer and gyroscope can record the quantified attributes of Parkinson’s disease and tremor through mounting the smartphone about the dorsum of the hand. The recorded data can be then wirelessly transmitted as an email attachment to an Internet derived resource for subsequent post-processing. The inertial sensor data can be consolidated into a feature set for machine learning classification. A multilayer perceptron neural network has been successfully applied to attain considerable classification accuracy between deep brain stimulation “On” and “Off” scenarios for a subject with Parkinson’s disease. The findings establish the foundation for the broad objective of applying wearable and wireless systems for the development of closed-loop optimization of deep brain stimulation parameters in the context of cloud computing with machine learning classification.
基金financially supported by the Natural Science Foundation of Anhui Province(KJ2018A0534)the research fund of Anhui Science and Technology University(ZRC2014402)+1 种基金Materials Science and Engineering Key Discipline Foundation(AKZDXK2015A01)the Deanship of Scientific Research at King Saud University for its funding of this research through the Research Group Project No.Prolific Research Group No.1436-011
文摘Lithium-ion batteries(LIBs) are considered new generation of large-scale energy-storage devices.However,LIBs suffer from a lack of desirable anode materials with excellent specific capacity and cycling stability.In this work,we design a novel hierarchical structure constructed by encapsulating cobalt sulfide nanowires within nitrogen-doped porous branched carbon nanotubes(NBNTs)for LIBs.The unique hierarchical Co9S8@NBNT electrode displayed a reversible specific capacity of 1310 mAhg-1 at a current density of 0.1 Ag-1,and was able to maintain a stable reversible discharge capacity of 1109 mAhg-1 at a current density of 0.5 Ag-1 with coulombic efficiency reaching almost 100% for 200 cycles.The excellent rate and cycling capabilities can be ascribed to the hierarchical porosity of the one-dimensional Co9S8@NBNT internetworks,the incorporation of nitrogen doping,and the carbon nanotube confinement of the active cobalt sulfide nanowires offering a proximate electron pathway for the isolated nanoparticles and shielding of the cobalt sulfide nanowires from pulverization over long cycling periods.
基金National Natural Science Foundation of China(Nos.21804007 and 21890742)Youth Scholars of Beijing Technology and Business University(No.QNJJ2020-04)+1 种基金SZU Top Ranking Project(No.86000000210)Shenzhen Stability Support Plan(No.20200806163622001)。
文摘The multiple sensing provides booming options to eliminate interference and ensure the accuracy of detection by mutually coupling and validating multiple data sets.Here,we integrate the jigsaw-like multifunctional mini-pillar platform to perform multi-mode(electrochemical,fluorescence,surface-enhanced Raman scattering(SERS)and colorimetric)sensing in individual microdroplets.Each mini-pillar connector can parallelize together by specific concave-convex interface to form integrated jigsaw-like platform for multi-mode sensing,and each specific mini-pillar can be modified into the individual sensing unit to read the prescribed signals.We successfully implemented electrochemical,fluorescence,SERS and colorimetric detection by multiple signals coupling to reduce the false positive analysis.Such platform brings a promising clue of in-situ analysis and point-of-care testing for disease diagnosis and health monitoring.
基金the National Natural Science Foundation of China(Nos.42061134020,32070380)the Natural Science Foundation of Shandong Province(No.ZR2019ZD17)。
文摘Light plays an important role in the photosynthesis and metabolic process of microalgae.However,how different light conditions regulate the biomass production and protein accumulation of microalgae is mostly unknown.In this study,the influence of different light conditions,including light colors,densities,and light:dark cycles on the cell growth and biochemical composition of Spirulina platensis was symmetrically characterized.Under different colored lights,S.platensis all shows an increase trend within the increased light intensity ranges;however,each showing different optimal light intensities.At the same light intensity,different colored lights show different growth rate of S.platensis following the sequence of red>white>green>yellow>blue.The maximum growth rate and protein accumulation were determined as 21.88 and 5.10 mg/(L·d)when illuminated under red LED.The energy efficiency of different light sources was calculated and ranked as red>white>blue≈green>yellow.Transcriptomic analysis suggests that red light can promote cell growth and protein accumulation by upregulating genes related to photosynthesis,carbon fixation,and C-N metabolism pathways.This study provides a conducive and efficient way to promote biomass production and protein accumulation of S.platensis by regulating light conditions.
基金Project supported by the National Basic Research Program of China(Grant No.2013CB932804)the National Natural Science Foundation of China(Grant Nos.11421063,11647601,11504431,and 21503275)+1 种基金the Scientific Research Foundation of China University of Petroleum(East China)for Young Scholar(Grant Y1304073)financial support through the CAS Biophysics Interdisciplinary Innovation Team Project(Grant No.2060299)
文摘Nanostructures self-assembled by cross-β peptides with ordered structures and advantageous mechanical properties have many potential applications in biomaterials and nanotechnologies. Quantifying the intra-and inter-molecular driving forces for peptide self-assembly at the atomistic level is essential for understanding the formation mechanism and nanomechanics of various morphologies of self-assembled peptides. We investigate the thermodynamics of the intra-and inter-sheet structure formations in the self-assembly process of cross-β peptide KⅢIK by means of steered molecular dynamics simulation combined with umbrella sampling. It is found that the mechanical properties of the intra-and inter-sheet structures are highly anisotropic with their intermolecular bond stiffness at the temperature of 300 K being 5.58 N/m and 0.32 N/m, respectively. This mechanical anisotropy comes from the fact that the intra-sheet structure is stabilized by enthalpy but the inter-sheet structure is stabilized by entropy. Moreover, the formation process of KⅢIK intra-sheet structure is cooperatively driven by the van der Waals （VDW） interaction between the hydrophobic side chains and the electrostatic interaction between the hydrophilic backbones, but that of the inter-sheet structure is primarily driven by the VDW interaction between the hydrophobic side chains. Although only peptide KⅢIK is studied, the qualitative conclusions on the formation mechanism should also apply to other cross-β peptides.
基金supported by the National Natural Science Foundation of China(Nos.22034005,81973569,and 21621003).
文摘3D microgels with various mechanical properties have been important platforms tumor metastasis analysis,and widely adjustable stiffness is crucial for deeper researches.Herein,by mixing biodegradable polylactic acid(PLA)nanofibers in the modified alginate with different concentrations of Ca^(2+),we significantly enhance the stiffness range of microgels while retaining the pore size,which provides bionic microenvironment for tumor analysis.As a proof of concept,we simulated the mechanical characteristics of breast tumors by encapsulating cells in 3D microgels with diverse stiffness,and analyzed cellular behaviors of two typical breast cancer cell lines:MCF-7 and SUM-159.Results showed that with the addition of 2.0%(w/v)PLA short nanofibers,the Young’s modulus of modified alginate increased more than three-fold.Besides preserving high survival and proliferation rates,both cells also displayed stronger migration ability in soft microgel spheres,where RT-qPCR analysis revealed the underlying changes at the genetic level.This systematic study demonstrated our method is powerful for creating widely adjustable 3D mechanical microenvironment,and the results of cellular behavior analysis shows its promising application prospects in tumorigenesis and progression.
基金Supported by the National Natural Science Foundation of China (Nos. 42061134020, 32070380)the Natural Science Foundation of Shandong Province (No. ZR2019ZD17)
文摘In this article,the legend for Fig.3 f&g was inadvertently mislabeled.The figure below shows the wrong one.The figure should have appeared as shown below.
文摘This study is focused on investigation of biofilms formed in an anaerobic laboratory-scale bioreactor fed with medium for anammox bacteria oxidizing ammonia with nitrite. The mixed culture of anammox bacteria was enriched from the microbial community that sampled from the activated sludge of a denitrifying reactor at a wastewater treatment station located in the Sochi region, Russia. This community forms biofilms on the surface of the flexible polymer brush carriers, which are used for biomass immobilization in both laboratory and full-scale bioreactors. Anammox bacteria were discovered in the activated sludge community. The anammox community was enriched by incubation in an up-flow laboratory-scale anaerobic bioreactor with a flexible brush carrier. In the course of ~3 years, the loading rate of nitrogen substrates (ammonium and nitrite) increased from 100 to 5000 mg N L-1 day-1. The concentration of the substrates in the upper part of the reactor was 40 times less than in the influent. The pH values were 7.5 at the bottom and up to 9 in the upper part up of the reactor. Biofilms of two types developed in the reactor. Bunches of irregular spherical granules formed on the carrier filaments, while films of irregular thickness containing submerged spherical granules were formed on the walls of reactor. The anammox population was found to consist of at least three active species: a new strain of Candidatus “Jettenia asiatica” named “strain ecos” and two species of the genus Candidatus “Brocadia”. Other types of bacteria found in the community, including members of phylum Chloroflexi, were presumably involved in biofilm spatial organization.
文摘Regeneration of damaged retinal ganglion cells（RGC） and their axons is an important aspect of reversing vision loss in glaucoma patients. While current therapies can effectively lower intraocular pressure, they do not provide extrinsic support to RGCs to actively aid in their protection and regeneration. The unmet need could be addressed by neurotrophic factor gene therapy, where plasmid DNA, encoding neurotrophic factors, is delivered to retinal cells to maintain sufficient levels of neurotrophins in the retina. In this review, we aim to describe the intricacies in the design of the therapy including： the choice of neurotrophic factor, the site and route of administration and target cell populations for gene delivery. Furthermore, we also discuss the challenges currently being faced in RGC-related therapy development with special considerations to the existence of multiple RGC subtypes and the lack of efficient and representative in vitro models for rapid and reliable screening in the drug development process.
基金sponsored by Science and Technology Support for Major Projects of Hebei Province, No. 09276103DHebei Province Science and Technology Research and Development Program, No. 08206120D
文摘In the present study, transplantation of bone marrow-derived mesenchymal stem cells modified with brain-derived neurotrophic factor gene into the lateral ventricle of a rat model of Alzheimer＇s disease, resulted in significant attenuation of nerve cell damage in the hippocampal CA1 region. Furthermore, brain-derived neurotrophic factor and tyrosine kinase B mRNA and protein levels were significantly increased, and learning and memory were significantly improved. Results indicate that transplantation of bone marrow-derived mesenchymal stem cells modified with brain-derived neurotrophic factor gene can significantly improve cognitive function in a rat model of Alzheimer＇s disease, possibly by increasing the levels of brain-derived neurotrophic factor and tyrosine kinase B in the hippocampus.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.21727814,81872829,21621003,21890740).
文摘Researches on detection of human papillomavirus(HPV)high-risk samples were carried out by polymerase chain reaction(PCR)coupled with microchip electrophoresis(MCE).Herein,we introduced a simple,rapid,automated method for detecting high-risk samples HPV16 and HPV18.In this research,general primers were initially selected to obtain sufficient detectable yield by PCR to verify feasibility of MCM method for HPV detection,then type-specific primers were further used to evaluate the specificity of MCE method.The results indicated MCE method was capable of specifically detecting high-risk HPV16 and HPV18,and also enabled simultaneous detection of multiplex samples.This MCE method described here has been successfully applied to HPV detection and displayed excellent reliability demonstrating by sequencing results.The inherent capability of MCE facilitated HPV detection conducted in a small chip with automated,high throughput,massive parallelized analysis.We envision that MCE method will definitely pave a way for clinical diagnosis,and even on-site screening of cervical cancer.
基金supported by Kiisa Nishikawa: the National Science Foundation (IOS-0732949, IOS-1025806, and IOS1456868 IIP-1237878 and IIP-1521231)the W.M. Keck Foundation+5 种基金the Technology Research Initiative Fund of Northern Arizona UniversityPaul LaStayo:National Institutes of Health (ROIAG031255R21CA114523R21AG18701(with Stan Lindstedt))the Foundation for Physical Therapythe University of Utah Research Foundation
文摘The peculiar attributes of muscles that are stretched when active have been noted for nearly a century.Understandably,the focus of muscle physiology has been primarily on shortening and isometric contractions,as eloquently revealed by A.V.Hill and subsequently by his students.When the sliding filament theory was introduced by A.F.Huxley and H.E.Huxley,it was a relatively simple task to link Hill's mechanical observations to the actions of the cross bridges during these shortening and isometric contractions.In contrast,lengthening or eccentric contractions have remained somewhat enigmatic.Dismissed as necessarily causing muscle damage,eccentric contractions have been much more difficult to fit into the cross-bridge theory.The relatively recent discovery of the giant elastic sarcomeric filament titin has thrust a previously missing element into any discussion of muscle function,in particular during active stretch.Indeed,the unexpected contribution of giant elastic proteins to muscle contractile function is highlighted by recent discoveries that twitchin-actin interactions are responsible for the"catch"property of invertebrate muscle.In this review,we examine several current theories that have been proposed to account for the properties of muscle during eccentric contraction.We ask how well each of these explains existing data and how an elastic filament can be incorporated into the sliding filament model.Finally,we review the increasing body of evidence for the benefits of including eccentric contractions into a program of muscle rehabilitation and strengthening.
基金supported by the Hebei Grass Industry Innovation Team of the Modern Agricultural Industry Technology System(HBCT2018050204).
文摘Allium senescens,is an important economic and ecological grassland plant with drought-resistant characteristics.A TCP protein transcription factor is important in the regulation of plant development and adverse responses.However,the mechanism by which TCP transcription functions in drought resistance in Allium senescens is still not clear.Here,we obtained a total of 190,305 transcripts with 115,562 single gene clusters based on RNA-Seq sequencing of Allium senescens under drought stress.The total number of bases was 97,195,096 bp,and the average length was 841.06 bp.Furthermore,we found that there were eight genes of the TCP family that showed an upregulated expression trend under drought stress in Allium senescens.We carried out an investigation to determine the evolution and function of the AsTCP family and how they produce an effect in drought resistance.The 14 AsTCP genes were confirmed and divided into class I and class II containing CIN and CYC/TBI subfamilies,respectively.We also found that the expression of AsTCP17 was remarkably upregulated with drought treatment.Besides,the transformation of AsTCP17 in Arabidopsis revealed that the protective enzymes,namely polyphenol oxidase(POD)and superoxide dismutase(SOD),were increased by 0.4 and 0.8 times,respectively.Chlorophyll content was also increased,while the H2O2 and malondialdehyde(MDA)contents were decreased.Staining assays with 3,3′-diaminobenzidine(DAB)also suggested that the AsTCP17 downregulates reactive oxygen species(ROS)accumulation.In addition,overexpression of the AsTCP17 affected the accumulation of drought-related hormones in plants,and the synthesis of ABA.The expression of AtSVP and AtNCED3,related ABA synthesis pathway genes,indicated that the level of expression of AtSVP and AtNCED3 was obviously enhanced,with the overexpression of line 6 showing a 20.6-fold and 7.0-fold increase,respectively.Taken together,our findings systematically analyze the AsTCPs family at the transcriptome expression level in Allium senescens,and we also demonstrated that AsTCP17 protein,as a positive regulator,was involved in drought resistance of Allium senescens.In addition,our research contributes to the comprehensive understanding of the drought stress defense mechanism in herbaceous plants.
基金the financial support from the National Natural Science Foundation of China(Nos.21005006 and 21127007)the Fundamental Research Funds for the Central Universities(Nos.06108101,06199019 and 06199024)
文摘Received 15 November 2012 Received in revised form 5 December 2012 Accepted 12 December 2012 Available online 20 January 2013
基金Supported by The Ministry of Science of Serbia with the grants OI144028 and TR12007
文摘AIM： To investigate the flow and mixing at the duodenal stump after gastric resection, a computer simulation was implemented. METHODS： Using the finite element method, two different Billroth fl procedure cases （A and B） were modeled. Case A was defined with a shorter and almost straight duodenal section, while case B has a much longer and curved duodenal section. Velocity, pressure and food concentration distribution were determined and the numerical results were compared with experimental observations. RESULTS： The pressure distribution obtained by numerical simulation was in the range of the recorded experimental results. Case A had a more favorable pressure distribution in comparison with case B. However, case B had better performance in terms of food transport because of more continual food distribution, as well as better emptying of the duodena section. CONCLUSION： This study offers insight into the transport process within the duodenal stump section after surgical intervention, which can be useful for future patient-specific predictions of a surgical outcome.
基金sponsored by the National Natural Science Foundation of China(Nos.52171036,52065043,and 51971108)the Central Guidance on Local:Construction of regional innovation system-Cross Regional R&D cooperation projects(No.20221ZDH04054)the Interdisciplinary Innovation Fund of Natural Science,Nanchang Universit
文摘Porous Ti with low modulus,excellent bio-corrosion resistance,biocompatibility,and antibacterial activity is highly pursued as advanced implant materials.In this work,a new approach to prepare micron porous structures on the surface layer of a grade 2 commercially-pure Ti(TA2)was proposed,which utilized a simple vacuum wetting process of pure Ag on the surface of TA2.The microstructure,corrosion resistance,biocompatibility,mechanical properties,antibacterial ability,and formation mechanism of the asfabricated porous Ti were studied.The results show that the pores(with average pore sizes of 0.5-5μm)are distributed on the surface layer of the TA2 with a depth of~10μm.In particular,a large number of silver nanoparticles(Ag NPs)form which are dispersed on the porous structures.The formation mechanisms of the porous structures and Ag NPs were elucidated,suggesting that the volatilization/sublimation of Ag in TA2 is crucial.The porous Ti possesses excellent bio-corrosion resistance,surface wettability,biocompatibility,antibacterial activity,and a relatively low elastic modulus of 40-55 GPa,which may have a promising future in the field of orthopedic implants.This work also provides a novel idea for the development of advanced porous Ti materials for orthopedic-related basic research and biomedical applications.
基金the financial support provided by the National Natural Science Foundation of China(No.41176144)Public Science and Technology Research Funds Projects of Ocean(No.200905021-3)+1 种基金supported by the Shandong Province Natural Science Foundation(No. ZR2012DQ015)the Fundamental Research Funds for the Central Universities(No.10CX05003A)
文摘Received 30 November 2012 Received in revised form 5 December 2012 Accepted 12 December 2012 Available online 21 January 2013
基金the National Natural Science Foundation of China(Nos. 21461015, 31860263 to Xiaolei Wang No. 91639106 to Hongbo Xin)+1 种基金Science Foundation of Jiangxi Provincial Department of Education(Nos. KJLD14010, 20153BCB23035, 20161ACB21002, 20165BCB19002 to Xiaolei Wang)Nanchang University Seed Grant for Biomedicine
文摘Black fungus derived carbonaceous aerogel (BFA) was prepared via a convenient and energy efficient ultrasonic disposal process. The adsorption experiments of atmospheric pollutants demonstrated the superior adsorbability of black fungus aerogel on PM2.5, PM10 and formaldehyde. More importantly, black fungus aerogel (BFA) exhibited intriguing double-faced properties. We explored properties of each side of the black fungus from three aspects: water contact angle measurements, liquid selective absorption capacity and air pollutant adsorption abilities. The subsequent modification of ZnO nanosheets endowed the prepared black fungus aerogel with several valuable properties, including broad-spectrum antibacterial capability and high-efficient adsorption ability. These valuable characters implied the BFA to be a promising bacteriostat and cleaner for air and water pollution treatment.
基金supported by the National Natural Science Foundation of China (31720103911)the China Agriculture Research System of MOF and MARAthe Science and Technology Major Projects of Inner Mongolia Autonomous Region (2021ZD0014)
文摘Conventional filling therapy fails to fundamentally reduce oral cariogenic bacteria.Thus,oral microbiota follow-up intervention after filling would be necessary for improving dental caries prognosis.We recruited 9 caries-free individuals,and 89 dental caries subjects(5 dropouts).Eighty-nine patients were randomized into three groups:caries(n=8;no treatment),control(n=40;filling),and postbiotics(n=41;filling and 14-day Probio-Eco®intervention).Salivary samples were collected at 0 day(after filling)and 14 days.Our results showed that the diversity of dental caries oral microbiota was significantly increased compared with healthy subjects,and filling could restore a healthier oral microbiota partially and temporarily.Thepostbiotics intervention keeps a low alpha-diversity.Co-occurrence network analysis showed that a more stable oral microbiota structure after postbiotics intervention.Taxonomic and functional annotation of the microbiota revealed that postbiotics co-treatment significantly:increased the relative abundance of Pseudomonas and P.reactans,decreased the relative abundance of Prevotella shahii,and enriched the energy metabolism-related pathways.BugBase-predicted phenotypes inferred to an oral microbiota with decreased potential pathogenic bacteria and increased oxidative stress-tolerant bacteria after postbiotics intervention.Collectively,it suggested that postbiotics co-treatment could be a promising strategy that restores the oral microecological balance for dental caries.
