Atrophic fracture nonunion poses a significant clinical problem with limited therapeutic interventions.In this study,we developed a unique nonunion model with high clinical relevance using serum transfer-induced rheum...Atrophic fracture nonunion poses a significant clinical problem with limited therapeutic interventions.In this study,we developed a unique nonunion model with high clinical relevance using serum transfer-induced rheumatoid arthritis(RA).Arthritic mice displayed fracture nonunion with the absence of fracture callus,diminished angiogenesis and fibrotic scar tissue formation leading to the failure of biomechanical properties,representing the major manifestations of atrophic nonunion in the clinic.Mechanistically,we demonstrated that the angiogenesis defect observed in RA mice was due to the downregulation of SPP1 and CXCL12 in chondrocytes,as evidenced by the restoration of angiogenesis upon SPP1 and CXCL12 treatment in vitro.In this regard,we developed a biodegradable scaffold loaded with SPP1 and CXCL12,which displayed a beneficial effect on angiogenesis and fracture repair in mice despite the presence of inflammation.Hence,these findings strongly suggest that the sustained release of SPP1 and CXCL12 represents an effective therapeutic approach to treat impaired angiogenesis and fracture nonunion under inflammatory conditions.展开更多
Development of an electrocatalyst that is cheap and has good properties to replace conventional noble metals is important for H_(2) applications.In this study,dealloying of an amorphous Ti_(37)Cu_(60)Ru_(3) alloy was ...Development of an electrocatalyst that is cheap and has good properties to replace conventional noble metals is important for H_(2) applications.In this study,dealloying of an amorphous Ti_(37)Cu_(60)Ru_(3) alloy was performed to prepare a freestanding nanostructured hydrogen evolution reaction(HER)catalyst.The effect of dealloying and addition of Ru to TiCu alloys on the microstructure and HER properties under alkaline conditions was investigated.3 at.%Ru addition in Ti_(40)Cu_(60) decreases the overpotential to reach a current density of 10mA cm^(-2) and Tafel slope of the dealloyed samples to 35 and 34mV dec−1.The improvement of electrocatalytic properties was attributed to the formation of a nanostructure and the modification of the electronic structure of the catalyst.First-principles calculations based on density function theory indicate that Ru decreases the Gibbs free energy of water dissociation.This work presents a method to prepare an efficient electrocatalyst via dealloying of amorphous alloys.展开更多
Based on the investigated microstructure of different zones in the annealed automatic gas tungsten arc weld joint of TA16 and TC4 titanium alloys,the mechanical property of them was assessed under fatigue crack growth...Based on the investigated microstructure of different zones in the annealed automatic gas tungsten arc weld joint of TA16 and TC4 titanium alloys,the mechanical property of them was assessed under fatigue crack growth rate tests.For evaluation of fatigue crack growth rate,three points bending specimens were used.The correlation between the range of stress intensity factor and crack growth rate was determined in different zones of the annealed weld joint.Fatigue crack growth rates were obviously different in different zones of weld joint of dissimilar titanium alloys,due to their different microstructures.Scanning electron microscope examinations were conducted on the fracture surface in order to determine the relevant fracture mechanisms and crack growth mechanisms with respect to the details of microstructure.展开更多
BACKGROUND Abdominal wall deficiencies or weakness are a common complication of tem-porary ostomies,and incisional hernias frequently develop after colostomy or ileostomy takedown.The use of synthetic meshes to reinfo...BACKGROUND Abdominal wall deficiencies or weakness are a common complication of tem-porary ostomies,and incisional hernias frequently develop after colostomy or ileostomy takedown.The use of synthetic meshes to reinforce the abdominal wall has reduced hernia occurrence.Biologic meshes have also been used to enhance healing,particularly in contaminated conditions.Reinforced tissue matrices(R-TMs),which include a biologic scaffold of native extracellular matrix and a syn-thetic component for added strength/durability,are designed to take advantage of aspects of both synthetic and biologic materials.To date,RTMs have not been reported to reinforce the abdominal wall following stoma reversal.METHODS Twenty-eight patients were selected with a parastomal and/or incisional hernia who had received a temporary ileostomy or colostomy for fecal diversion after rectal cancer treatment or trauma.Following hernia repair and proximal stoma closure,RTM(OviTex®1S permanent or OviTex®LPR)was placed to reinforce the abdominal wall using a laparoscopic,robotic,or open surgical approach.Post-operative follow-up was performed at 1 month and 1 year.Hernia recurrence was determined by physical examination and,when necessary,via computed tomo-graphy scan.Secondary endpoints included length of hospital stay,time to return to work,and hospital readmissions.Evaluated complications of the wound/repair site included presence of surgical site infection,seroma,hematoma,wound dehiscence,or fistula formation.RESULTS The observational study cohort included 16 male and 12 female patients with average age of 58.5 years±16.3 years and average body mass index of 26.2 kg/m^(2)±4.1 kg/m^(2).Patients presented with a parastomal hernia(75.0%),in-cisional hernia(14.3%),or combined parastomal/incisional hernia(10.7%).Using a laparoscopic(53.6%),robotic(35.7%),or open(10.7%)technique,RTMs(OviTex®LPR:82.1%,OviTex®1S:17.9%)were placed using sublay(82.1%)or intraperitoneal onlay(IPOM;17.9%)mesh positioning.At 1-month and 1-year follow-ups,there were no hernia recurrences(0%).Average hospital stays were 2.1 d±1.2 d and return to work occurred at 8.3 post-operative days±3.0 post-operative days.Three patients(10.7%)were readmitted before the 1-month follow up due to mesh infection and/or gastrointestinal issues.Fistula and mesh infection were observed in two patients each(7.1%),leading to partial mesh removal in one patient(3.6%).There were no complications between 1 month and 1 year(0%).CONCLUSION RTMs were used successfully to treat parastomal and incisional hernias at ileostomy reversal,with no hernia recurrences and favorable outcomes after 1-month and 1-year.展开更多
Photocatalysis is an advanced oxidation process where light exposure triggers a semiconducting nanomaterial(nano-photocatalyst)to generate electron-hole(e^(-)/h^(+))pairs and free radicals.This phenomenon is widely us...Photocatalysis is an advanced oxidation process where light exposure triggers a semiconducting nanomaterial(nano-photocatalyst)to generate electron-hole(e^(-)/h^(+))pairs and free radicals.This phenomenon is widely used for the photocatalysis-assisted removal of organic and other contaminants using wide range of nanophotocatalysts,offering an efficient approach to environmental remediation.However,the introduction of powdered nano-photocatalysts into water systems often leads to unintended secondary pollution in the form of residual nano-photocatalysts,ion leaching,free radicals,toxic by-products etc.Such practices potentially introduce emerging secondary contaminants into aquatic environments,posing risks to both aquatic life and human health.The resulting chemical by-products and intermediates can effectively induce chronic toxicity,neurological and developmental disorders,cardiovascular defects,and intestinal ailments in humans and aquatic species.Despite having a range of health and environmental consequences,this dark side of nano-photocatalysts has been comparatively less explored and discussed in the literature.In this review,the pros and cons of powder nanophotocatalysts are discussed in view of their advantages as well as disadvantages in wastewater treatment.The discussion encompasses their classification based on composition,dimensions,structure,and activity,as well as recent advancements in improving their photocatalytic efficiency.The article also explores the recent advances on their applications in photocatalytic removal of various water pollutants/contaminants of emerging concern(i.e.,organic pollutants,micro/nano plastics,heavy ions,disinfections,etc.)Furthermore,an emphasis on the role of such nano-photocatalysts as emerging(secondary)contaminants in water system,along with a thorough discussion of latest studies related to the health and environmental issues,has been discussed.Additionally,it addresses critical issues in applying powder nano-photocatalysts for wastewater detoxification and explores potential solutions to these challenges followed by future prospects.展开更多
After myocardial infarction(MI),ventricular dilation and the microscopic passive stretching of the infarcted border zone is the meaning contributor to the continuous expansion of myocardial fibrosis.Epicardial hydroge...After myocardial infarction(MI),ventricular dilation and the microscopic passive stretching of the infarcted border zone is the meaning contributor to the continuous expansion of myocardial fibrosis.Epicardial hydrogel patches have been demonstrated to alleviate this sequela of MI in small-animal models.However,these have not been successfully translated to humans or even large animals,in part because of challenges in attaining both the greater stiffness and slower viscoelastic relaxation that mathematical models predict to be optimal for application to larger,slower-beating hearts.Here,using borate-based dynamic covalent chemistry,we develop an injectable“heart rate matched”viscoelastic gelatin(VGtn)hydrogel with a gel point tunable across the stiffnesses and frequencies that are predicted to transspecies and cross-scale cardiac repair after MI.Small-animal experiments demonstrated that,compared to heart rate mismatched patches,the heart rate matched VGtn patches inhibited ventricular bulging and attenuated stress concentrations in the myocardium after MI.In particular,the viscoelastic patch can coordinate the microscopic strain at the infarction boundary.VGtn loaded with anti-fibrotic agents further reduced myocardial damage and promoted angiogenesis in the myocardium.The tuned heart rate matched patches demonstrated similar benefits in a larger-scale and lower heart rate porcine MI model.Results suggest that heart rate matched VGtn patches may hold potential for clinical translation.展开更多
Rapid progress in graphene-based applications is calling for new processing techniques for creating graphene components with different shapes,sizes,and edge structures.Here we report a controlled cutting process for g...Rapid progress in graphene-based applications is calling for new processing techniques for creating graphene components with different shapes,sizes,and edge structures.Here we report a controlled cutting process for graphene sheets,using nickel nanoparticles as a knife that cuts with nanoscale precision.The cutting proceeds via catalytic hydrogenation of the graphene lattice,and can generate graphene pieces with specifi c zigzag or armchair edges.The size of the nanoparticle dictates the edge structure that is produced during the cutting.The cutting occurs along straight lines and along symmetry lines,defined by angles of 60ºor 120º,and is defl ected at free edges or defects,allowing practical control of graphene nano-engineering.展开更多
In pristine graphene ribbons,disruption of the aromatic bond network results in depopulation of covalent orbitals and tends to elongate the edge,with an effective force of fe~2 eV/Å(larger for armchair edges than...In pristine graphene ribbons,disruption of the aromatic bond network results in depopulation of covalent orbitals and tends to elongate the edge,with an effective force of fe~2 eV/Å(larger for armchair edges than for zigzag edges,according to calculations).This force can have quite striking macroscopic manifestations in the case of narrow ribbons,as it favors their spontaneous twisting,resulting in the parallel edges forming a double helix,resembling DNA,with a pitchλt of about 1520 lattice parameters.Through atomistic simulations,we investigate how the torsionτ~1/λt decreases with the width of the ribbon,and observe its bifurcation:the twist of wider ribbons abruptly vanishes and instead the corrugation localizes near the edges.The length-scale(λe)of the emerging sinusoidal“frill”at the edge is fully determined by the intrinsic parameters of graphene,namely its bending stiffness D=1.5 eV and the edge force fe withλe~D/fe.Analysis reveals other warping configurations and suggests their sensitivity to the chemical passivation of the edges,leading to possible applications in sensors.展开更多
The term“structural lubricity”denotes a fundamental concept where the friction between two atomically flat surfaces is reduced due to lattice mismatch at the interface.Under favorable circumstances,its effect may ca...The term“structural lubricity”denotes a fundamental concept where the friction between two atomically flat surfaces is reduced due to lattice mismatch at the interface.Under favorable circumstances,its effect may cause a contact to experience ultra-low friction,which is why it is also referred to as“superlubricity”.While the basic principle is intriguingly simple,the experimental analysis of structural lubricity has been challenging.One of the main reasons for this predicament is that the tool most frequently used in nanotribology,the friction force microscope,is not well suited to analyse the friction of extended nanocontacts.To overcome this deficiency,substantial efforts have been directed in recent years towards establishing nanoparticle manipulation techniques,where the friction of nanoparticles sliding on a substrate is measured,as an alternative approach to nanotribological research.By choosing appropriate nanoparticles and substrates,interfaces exhibiting the characteristics needed for the occurrence of structural lubricity can be created.As a consequence,nanoparticle manipulation experiments such as in this review represent a unique opportunity to study the physical conditions and processes necessary to establish structural lubricity,thereby opening a path to exploit this effect in technological applications.展开更多
The novel jet self-priming centrifugal pump,as important modern irrigation equipment,is widely used in large-scale irrigation,mine drainage and so on.In order to improve the profile streamline of blade,the inlet shape...The novel jet self-priming centrifugal pump,as important modern irrigation equipment,is widely used in large-scale irrigation,mine drainage and so on.In order to improve the profile streamline of blade,the inlet shape of impeller was designed as distorted and the outlet shape as cylindrical,which can not only improve the pump efficiency,but also shorten the self-priming time.Further,the novel jet self-priming system was proposed,by employing the jet nozzle and check valve to improve the velocity of self-priming.Meanwhile,nine different structure jet nozzles were designed based on the orthogonal design method,and the relevant self-priming experiments were performed on I level accuracy test bench in Jiangsu University.According to the greycorrelational analysis,the influence of the nozzle geometry parameters on the self-priming performance was obtained.The relationship between self-priming time and self-priming height was discussed.The test results showed that the hydraulic design of jet self-priming centrifugal pump was reasonable;all indicators met the Chinese national standard;the head reached 21.04 m and efficiency was 72.8%under the design flow condition.What is more,the self-priming performance was obviously improved by adjusting the geometrical parameters of nozzle.When the height of the self-priming process was 5.3 m,the self-priming time reached 62 s,which was much shorter than the national standard.Therefore,this research could provide reference for designing the structure of jet self-priming centrifugal pump.展开更多
Magnetic nanowires(NWs)are ideal materials for the fabrication of various multifunctional nanostructures which can be manipulated by an external magnetic fi eld.Highly crystalline and textured nanowires of nickel(Ni N...Magnetic nanowires(NWs)are ideal materials for the fabrication of various multifunctional nanostructures which can be manipulated by an external magnetic fi eld.Highly crystalline and textured nanowires of nickel(Ni NWs)and cobalt(Co NWs)with high aspect ratio(~330)and high coercivity have been synthesized by electrodeposition using nickel sulphate hexahydrate(NiSO_(4)·6H_(2)O)and cobalt sulphate heptahydrate(CoSO_(4)·7H_(2)O)respectively on nanoporous alumina membranes.They exhibit a preferential growth along〈110〉.A general mobility assisted growth mechanism for the formation of Ni and Co NWs is proposed.The role of the hydration layer on the resulting one-dimensional geometry in the case of potentiostatic electrodeposition is verified.A very high interwire interaction resulting from magnetostatic dipolar interactions between the nanowires is observed.An unusual low-temperature magnetisation switching for fi eld parallel to the wire axis is evident from the peculiar high fi eld M(T)curve.展开更多
Ideal percutaneous titanium implants request both antibacterial ability and soft tissue compatibility.ZnO structure constructed on titanium has been widely proved to be helpful to combat pathogen contamination,but the...Ideal percutaneous titanium implants request both antibacterial ability and soft tissue compatibility.ZnO structure constructed on titanium has been widely proved to be helpful to combat pathogen contamination,but the biosafety of ZnO is always questioned.How to maintain the remarkable antibacterial ability of ZnO and efficiently reduce the corresponding toxicity is still challenging.Herein,a hybrid hydrogel coating was constructed on the fabricated ZnO structure of titanium,and the coating was proved to be enzymatically-degradable when bacteria exist.Then the antibacterial activity of ZnO was presented.When under the normal condition(no bacteria),the hydrogel coating was stable and tightly adhered to titanium.The toxicity of ZnO was reduced,and the viability of fibroblasts was largely improved.More importantly,the hydrogel coating provided a good buffer zone for cell ingrowth and soft tissue integration.The curbed Zn ion release was also proved to be useful to regulate fibroblast responses such as the expression of CTGF and COL-I.These results were also validated by in vivo studies.Therefore,this study proposed a valid self-adaptive strategy for ZnO improvement.Under different conditions,the sample could present different functions,and both the antibacterial ability and soft tissue compatibility were finely preserved.展开更多
Physiological monitoring can provide detailed information about health conditions,and therefore presents great potentials for personalized healthcare.Flexible miniaturized sensors(FMS)for physiological monitoring have...Physiological monitoring can provide detailed information about health conditions,and therefore presents great potentials for personalized healthcare.Flexible miniaturized sensors(FMS)for physiological monitoring have garnered significant attention because of their wide applications in collecting health-related information,evaluating and managing the state of human wellness in long term.In this review,we focus on the time scale of human physiological monitoring,the needs and advances in miniaturized technologies for long-term monitoring in typical applications.We also discuss the rational sample sources of FMS to select proper strategies for specific monitoring cases.Further,existing challenges and promising prospects are also presented.展开更多
Critical size bone defects represent a significant challenge worldwide,often leading to persistent pain and physical disability that profoundly impact patients’quality of life and mental well-being.To address the int...Critical size bone defects represent a significant challenge worldwide,often leading to persistent pain and physical disability that profoundly impact patients’quality of life and mental well-being.To address the intricate and complex repair processes involved in these defects,we performed single-cell RNA sequencing and revealed notable shifts in cellular populations within regenerative tissue.Specifically,we observed a decrease in progenitor lineage cells and endothelial cells,coupled with an increase in fibrotic lineage cells and pro-inflammatory cells within regenerative tissue.Furthermore,our analysis of differentially expressed genes and associated signaling pathway at the single-cell level highlighted impaired angiogenesis as a central pathway in critical size bone defects,notably influenced by reduction of Spp1 and Cxcl12 expression.This deficiency was particularly pronounced in progenitor lineage cells and myeloid lineage cells,underscoring its significance in the regeneration process.In response to these findings,we developed an innovative approach to enhance bone regeneration in critical size bone defects.Our fabrication process involves the integration of electrospun PCL fibers with electrosprayed PLGA microspheres carrying Spp1 and Cxcl12.This design allows for the gradual release of Spp1 and Cxcl12 in vitro and in vivo.To evaluate the efficacy of our approach,we locally applied PCL scaffolds loaded with Spp1 and Cxcl12 in a murine model of critical size bone defects.Our results demonstrated restored angiogenesis,accelerated bone regeneration,alleviated pain responses and improved mobility in treated mice.展开更多
Heteroanionic oxysulfide perovskite compounds represent an emerging class of new materials allowing for a wide range of tunability in the electronic structure that could lead to a diverse spectrum of novel and improve...Heteroanionic oxysulfide perovskite compounds represent an emerging class of new materials allowing for a wide range of tunability in the electronic structure that could lead to a diverse spectrum of novel and improved functionalities.Unlike cation ordered double perovskites—where the origins and design rules of various experimentally observed cation orderings are well known and understood—anion ordering in heteroanionic perovskites remains a largely uncharted territory.展开更多
The shape memory effect and nanoindentation response of various phases of sputtered NiTi shape memory thin films were investigated as a function of temperature.The phase transformation temperatures of NiTi films were ...The shape memory effect and nanoindentation response of various phases of sputtered NiTi shape memory thin films were investigated as a function of temperature.The phase transformation temperatures of NiTi films were observed to be sensitive to a compositional shift.The mechanical properties of NiTi thin films also presented a significant response to phase transformations.At the same load,the maximum indentation depth for austenite is smaller than for martensite,indicating that martensite is softer than austenite.A martensite thin film was converted to austenite via in situ heating nanoindentation and displayed the mechanical properties similar to the austenite film at room temperature.These results underscore the validity of elevated temperature nanoindentation methods as a means of interrogating the mechanical properties of materials that undergo thermally-induced phase transformations.The details of the load–displacement curves are also described.展开更多
To study the influence of an elbow inlet on the rotating stall characteristics of a waterjet propulsion pump(WJPP),a three-dimensional internal flow field in a WJPP under a straight-pipe inlet and elbow inlet is numer...To study the influence of an elbow inlet on the rotating stall characteristics of a waterjet propulsion pump(WJPP),a three-dimensional internal flow field in a WJPP under a straight-pipe inlet and elbow inlet is numerically simulated.By comparing the hydraulic performance of WJPP under the two inlet conditions,the internal relationship between the inlet mode and the flow pattern in the pump is clarified.Based on unsteady pressure fluctuation characteristics and wavelet analysis,the influence of the inlet mode on the rotating stall is revealed,and the stall transient propagation characteristics under critical stall conditions are analyzed.The disturbance effects of the inlet channel geometry disappear under low flow rate conditions,the main disturbance is induced by the highspeed countercurrent,and the flow pattern under the elbow inlet is better than that under the straight-pipe inlet.Under the straight-pipe inlet,the single-stall nucleus in the WJPP temporarily experiences a low-frequency and high-amplitude disturbance,which subsequently transforms into a mode of multi-stall nuclei with high-frequency circumferential disturbance.Under the elbow inlet,the rotating stall always maintains a mode of high-amplitude and low-frequency disturbance,which represents the transient characteristics of a single stall core propagating in the circumferential direction inside the channel.The results of this study have a reference value for structural design optimization in a WJPP.展开更多
Neck injuries are significant causes of morbidity and mortality, and their chronic forms due to repetitive or sustained physical acts(e.g., prolonged use of mobile phone with a dropped head) are becoming increasingly ...Neck injuries are significant causes of morbidity and mortality, and their chronic forms due to repetitive or sustained physical acts(e.g., prolonged use of mobile phone with a dropped head) are becoming increasingly more prevalent. Many injuries are preventable but the prevention and control requires a clear basic understanding of the neck biomechanics. In this paper, we describe a first-of-its-kind study that integrates a gamut of state-of-the-art imaging modalities(dynamic radiography, computed tomography(CT), and magnetic resonance imaging(MRI)) and biodynamic measurements(motion capture, electromyography(EMG), force sensing), thereby investigating holistically the in vivo responses of the neck and its various interconnected musculoskeletal components during functional activities. We present a sample of findings to illustrate how the integrations at multiple levels can enable creating truly subject-specific neck musculoskeletal models and attaining novel insights that otherwise would be unattainable by a singular or subset of approaches.展开更多
基金supported by the following NIH/NIAMS grants:R01 grants(AR075860 and AR077616 to J.S.,AR072623 and AR049192 to Y.A.EB022018,HL138175,HL138353,AG056919,and AR077616 to J.G.),an R21 grant(AR077226 to J.S.),a P30 Core Center grant(AR074992 to the Musculoskeletal Research Center)a biomedical grant from Shriners Hospital for Children(#85160 to Y.A.).
文摘Atrophic fracture nonunion poses a significant clinical problem with limited therapeutic interventions.In this study,we developed a unique nonunion model with high clinical relevance using serum transfer-induced rheumatoid arthritis(RA).Arthritic mice displayed fracture nonunion with the absence of fracture callus,diminished angiogenesis and fibrotic scar tissue formation leading to the failure of biomechanical properties,representing the major manifestations of atrophic nonunion in the clinic.Mechanistically,we demonstrated that the angiogenesis defect observed in RA mice was due to the downregulation of SPP1 and CXCL12 in chondrocytes,as evidenced by the restoration of angiogenesis upon SPP1 and CXCL12 treatment in vitro.In this regard,we developed a biodegradable scaffold loaded with SPP1 and CXCL12,which displayed a beneficial effect on angiogenesis and fracture repair in mice despite the presence of inflammation.Hence,these findings strongly suggest that the sustained release of SPP1 and CXCL12 represents an effective therapeutic approach to treat impaired angiogenesis and fracture nonunion under inflammatory conditions.
基金National Natural Science Foundation of China,Grant/Award Number:52071217。
文摘Development of an electrocatalyst that is cheap and has good properties to replace conventional noble metals is important for H_(2) applications.In this study,dealloying of an amorphous Ti_(37)Cu_(60)Ru_(3) alloy was performed to prepare a freestanding nanostructured hydrogen evolution reaction(HER)catalyst.The effect of dealloying and addition of Ru to TiCu alloys on the microstructure and HER properties under alkaline conditions was investigated.3 at.%Ru addition in Ti_(40)Cu_(60) decreases the overpotential to reach a current density of 10mA cm^(-2) and Tafel slope of the dealloyed samples to 35 and 34mV dec−1.The improvement of electrocatalytic properties was attributed to the formation of a nanostructure and the modification of the electronic structure of the catalyst.First-principles calculations based on density function theory indicate that Ru decreases the Gibbs free energy of water dissociation.This work presents a method to prepare an efficient electrocatalyst via dealloying of amorphous alloys.
基金Funded in Part by the Grant from Technology and Industry for National Defense,China(No.AXXD1818)。
文摘Based on the investigated microstructure of different zones in the annealed automatic gas tungsten arc weld joint of TA16 and TC4 titanium alloys,the mechanical property of them was assessed under fatigue crack growth rate tests.For evaluation of fatigue crack growth rate,three points bending specimens were used.The correlation between the range of stress intensity factor and crack growth rate was determined in different zones of the annealed weld joint.Fatigue crack growth rates were obviously different in different zones of weld joint of dissimilar titanium alloys,due to their different microstructures.Scanning electron microscope examinations were conducted on the fracture surface in order to determine the relevant fracture mechanisms and crack growth mechanisms with respect to the details of microstructure.
基金This study was reviewed and approved by the UT Health Houston Institutional Review Board(approval No.HSC-MS-23-0471).
文摘BACKGROUND Abdominal wall deficiencies or weakness are a common complication of tem-porary ostomies,and incisional hernias frequently develop after colostomy or ileostomy takedown.The use of synthetic meshes to reinforce the abdominal wall has reduced hernia occurrence.Biologic meshes have also been used to enhance healing,particularly in contaminated conditions.Reinforced tissue matrices(R-TMs),which include a biologic scaffold of native extracellular matrix and a syn-thetic component for added strength/durability,are designed to take advantage of aspects of both synthetic and biologic materials.To date,RTMs have not been reported to reinforce the abdominal wall following stoma reversal.METHODS Twenty-eight patients were selected with a parastomal and/or incisional hernia who had received a temporary ileostomy or colostomy for fecal diversion after rectal cancer treatment or trauma.Following hernia repair and proximal stoma closure,RTM(OviTex®1S permanent or OviTex®LPR)was placed to reinforce the abdominal wall using a laparoscopic,robotic,or open surgical approach.Post-operative follow-up was performed at 1 month and 1 year.Hernia recurrence was determined by physical examination and,when necessary,via computed tomo-graphy scan.Secondary endpoints included length of hospital stay,time to return to work,and hospital readmissions.Evaluated complications of the wound/repair site included presence of surgical site infection,seroma,hematoma,wound dehiscence,or fistula formation.RESULTS The observational study cohort included 16 male and 12 female patients with average age of 58.5 years±16.3 years and average body mass index of 26.2 kg/m^(2)±4.1 kg/m^(2).Patients presented with a parastomal hernia(75.0%),in-cisional hernia(14.3%),or combined parastomal/incisional hernia(10.7%).Using a laparoscopic(53.6%),robotic(35.7%),or open(10.7%)technique,RTMs(OviTex®LPR:82.1%,OviTex®1S:17.9%)were placed using sublay(82.1%)or intraperitoneal onlay(IPOM;17.9%)mesh positioning.At 1-month and 1-year follow-ups,there were no hernia recurrences(0%).Average hospital stays were 2.1 d±1.2 d and return to work occurred at 8.3 post-operative days±3.0 post-operative days.Three patients(10.7%)were readmitted before the 1-month follow up due to mesh infection and/or gastrointestinal issues.Fistula and mesh infection were observed in two patients each(7.1%),leading to partial mesh removal in one patient(3.6%).There were no complications between 1 month and 1 year(0%).CONCLUSION RTMs were used successfully to treat parastomal and incisional hernias at ileostomy reversal,with no hernia recurrences and favorable outcomes after 1-month and 1-year.
基金Council of Scientific and Industrial Research(CSIR),New Delhi for providing Junior Research Fellowship(JRF),Ministry of Education(MoE)New Delhi and National Institute of Technology(NIT),Hamirpur for financial support.
文摘Photocatalysis is an advanced oxidation process where light exposure triggers a semiconducting nanomaterial(nano-photocatalyst)to generate electron-hole(e^(-)/h^(+))pairs and free radicals.This phenomenon is widely used for the photocatalysis-assisted removal of organic and other contaminants using wide range of nanophotocatalysts,offering an efficient approach to environmental remediation.However,the introduction of powdered nano-photocatalysts into water systems often leads to unintended secondary pollution in the form of residual nano-photocatalysts,ion leaching,free radicals,toxic by-products etc.Such practices potentially introduce emerging secondary contaminants into aquatic environments,posing risks to both aquatic life and human health.The resulting chemical by-products and intermediates can effectively induce chronic toxicity,neurological and developmental disorders,cardiovascular defects,and intestinal ailments in humans and aquatic species.Despite having a range of health and environmental consequences,this dark side of nano-photocatalysts has been comparatively less explored and discussed in the literature.In this review,the pros and cons of powder nanophotocatalysts are discussed in view of their advantages as well as disadvantages in wastewater treatment.The discussion encompasses their classification based on composition,dimensions,structure,and activity,as well as recent advancements in improving their photocatalytic efficiency.The article also explores the recent advances on their applications in photocatalytic removal of various water pollutants/contaminants of emerging concern(i.e.,organic pollutants,micro/nano plastics,heavy ions,disinfections,etc.)Furthermore,an emphasis on the role of such nano-photocatalysts as emerging(secondary)contaminants in water system,along with a thorough discussion of latest studies related to the health and environmental issues,has been discussed.Additionally,it addresses critical issues in applying powder nano-photocatalysts for wastewater detoxification and explores potential solutions to these challenges followed by future prospects.
基金supported by the National Natural Science Foundation of China(12402365,12225208,and U21A20337)the Young Talent Support Plan of Xi’an Jiaotong Universitythe Human Frontier Science Program(HFSP-RGP016/2024).
文摘After myocardial infarction(MI),ventricular dilation and the microscopic passive stretching of the infarcted border zone is the meaning contributor to the continuous expansion of myocardial fibrosis.Epicardial hydrogel patches have been demonstrated to alleviate this sequela of MI in small-animal models.However,these have not been successfully translated to humans or even large animals,in part because of challenges in attaining both the greater stiffness and slower viscoelastic relaxation that mathematical models predict to be optimal for application to larger,slower-beating hearts.Here,using borate-based dynamic covalent chemistry,we develop an injectable“heart rate matched”viscoelastic gelatin(VGtn)hydrogel with a gel point tunable across the stiffnesses and frequencies that are predicted to transspecies and cross-scale cardiac repair after MI.Small-animal experiments demonstrated that,compared to heart rate mismatched patches,the heart rate matched VGtn patches inhibited ventricular bulging and attenuated stress concentrations in the myocardium after MI.In particular,the viscoelastic patch can coordinate the microscopic strain at the infarction boundary.VGtn loaded with anti-fibrotic agents further reduced myocardial damage and promoted angiogenesis in the myocardium.The tuned heart rate matched patches demonstrated similar benefits in a larger-scale and lower heart rate porcine MI model.Results suggest that heart rate matched VGtn patches may hold potential for clinical translation.
文摘Rapid progress in graphene-based applications is calling for new processing techniques for creating graphene components with different shapes,sizes,and edge structures.Here we report a controlled cutting process for graphene sheets,using nickel nanoparticles as a knife that cuts with nanoscale precision.The cutting proceeds via catalytic hydrogenation of the graphene lattice,and can generate graphene pieces with specifi c zigzag or armchair edges.The size of the nanoparticle dictates the edge structure that is produced during the cutting.The cutting occurs along straight lines and along symmetry lines,defined by angles of 60ºor 120º,and is defl ected at free edges or defects,allowing practical control of graphene nano-engineering.
基金the Air Force Research Laboratory and by the Robert Welch Foundation(C-1590).
文摘In pristine graphene ribbons,disruption of the aromatic bond network results in depopulation of covalent orbitals and tends to elongate the edge,with an effective force of fe~2 eV/Å(larger for armchair edges than for zigzag edges,according to calculations).This force can have quite striking macroscopic manifestations in the case of narrow ribbons,as it favors their spontaneous twisting,resulting in the parallel edges forming a double helix,resembling DNA,with a pitchλt of about 1520 lattice parameters.Through atomistic simulations,we investigate how the torsionτ~1/λt decreases with the width of the ribbon,and observe its bifurcation:the twist of wider ribbons abruptly vanishes and instead the corrugation localizes near the edges.The length-scale(λe)of the emerging sinusoidal“frill”at the edge is fully determined by the intrinsic parameters of graphene,namely its bending stiffness D=1.5 eV and the edge force fe withλe~D/fe.Analysis reveals other warping configurations and suggests their sensitivity to the chemical passivation of the edges,leading to possible applications in sensors.
基金Financial support was provided by the DFG(Project SCHI 619/8-1)the EUROCORES program FANAS of the European Science Foundation,and the EC 6th framework program(Grant No.ERAS-CT-2003-980409)U.S.acknowledges primary financial support by the National Science Foundation through the Yale Materials Research Science and Engineering Center(Grant No.MRSEC DMR-1119826).
文摘The term“structural lubricity”denotes a fundamental concept where the friction between two atomically flat surfaces is reduced due to lattice mismatch at the interface.Under favorable circumstances,its effect may cause a contact to experience ultra-low friction,which is why it is also referred to as“superlubricity”.While the basic principle is intriguingly simple,the experimental analysis of structural lubricity has been challenging.One of the main reasons for this predicament is that the tool most frequently used in nanotribology,the friction force microscope,is not well suited to analyse the friction of extended nanocontacts.To overcome this deficiency,substantial efforts have been directed in recent years towards establishing nanoparticle manipulation techniques,where the friction of nanoparticles sliding on a substrate is measured,as an alternative approach to nanotribological research.By choosing appropriate nanoparticles and substrates,interfaces exhibiting the characteristics needed for the occurrence of structural lubricity can be created.As a consequence,nanoparticle manipulation experiments such as in this review represent a unique opportunity to study the physical conditions and processes necessary to establish structural lubricity,thereby opening a path to exploit this effect in technological applications.
基金the support from the National Natural Science Foundation of China (No. 51979138, No.51609105, No.51679111, No.51409127 and No.51579118)China Postdoctoral Science Foundation (Grant No.2016M601738 and 2018T110458)+7 种基金Natural Science Foundation of Jiangsu Province (BE2016163, BRA2017353 and No.BK20161472)Six Talents Peak Project of Jiangsu Province (No. JNHB-CXTD-005)Jiangsu Province University Natural Sciences Foundation (Grant No. 16KJB570002)Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)National Key R&D Program Project (No.2017YFC0403703)Open Foundation of National Research Center of Pumps (Grant No.NRCP201604)Graduate Student Scientific Research Innovation Projects of Jiangsu Province (Grant No. SJKY19_2547)Chinese Scholarship Council (CSC) for the financial support
文摘The novel jet self-priming centrifugal pump,as important modern irrigation equipment,is widely used in large-scale irrigation,mine drainage and so on.In order to improve the profile streamline of blade,the inlet shape of impeller was designed as distorted and the outlet shape as cylindrical,which can not only improve the pump efficiency,but also shorten the self-priming time.Further,the novel jet self-priming system was proposed,by employing the jet nozzle and check valve to improve the velocity of self-priming.Meanwhile,nine different structure jet nozzles were designed based on the orthogonal design method,and the relevant self-priming experiments were performed on I level accuracy test bench in Jiangsu University.According to the greycorrelational analysis,the influence of the nozzle geometry parameters on the self-priming performance was obtained.The relationship between self-priming time and self-priming height was discussed.The test results showed that the hydraulic design of jet self-priming centrifugal pump was reasonable;all indicators met the Chinese national standard;the head reached 21.04 m and efficiency was 72.8%under the design flow condition.What is more,the self-priming performance was obviously improved by adjusting the geometrical parameters of nozzle.When the height of the self-priming process was 5.3 m,the self-priming time reached 62 s,which was much shorter than the national standard.Therefore,this research could provide reference for designing the structure of jet self-priming centrifugal pump.
文摘Magnetic nanowires(NWs)are ideal materials for the fabrication of various multifunctional nanostructures which can be manipulated by an external magnetic fi eld.Highly crystalline and textured nanowires of nickel(Ni NWs)and cobalt(Co NWs)with high aspect ratio(~330)and high coercivity have been synthesized by electrodeposition using nickel sulphate hexahydrate(NiSO_(4)·6H_(2)O)and cobalt sulphate heptahydrate(CoSO_(4)·7H_(2)O)respectively on nanoporous alumina membranes.They exhibit a preferential growth along〈110〉.A general mobility assisted growth mechanism for the formation of Ni and Co NWs is proposed.The role of the hydration layer on the resulting one-dimensional geometry in the case of potentiostatic electrodeposition is verified.A very high interwire interaction resulting from magnetostatic dipolar interactions between the nanowires is observed.An unusual low-temperature magnetisation switching for fi eld parallel to the wire axis is evident from the peculiar high fi eld M(T)curve.
基金This work was financially supported by the National Natural Science Foundation of China(51825302,21734002&52021004)the State Key Project of Research and Development(Grant No.2016YFC1100300&2017YFB0702603).
文摘Ideal percutaneous titanium implants request both antibacterial ability and soft tissue compatibility.ZnO structure constructed on titanium has been widely proved to be helpful to combat pathogen contamination,but the biosafety of ZnO is always questioned.How to maintain the remarkable antibacterial ability of ZnO and efficiently reduce the corresponding toxicity is still challenging.Herein,a hybrid hydrogel coating was constructed on the fabricated ZnO structure of titanium,and the coating was proved to be enzymatically-degradable when bacteria exist.Then the antibacterial activity of ZnO was presented.When under the normal condition(no bacteria),the hydrogel coating was stable and tightly adhered to titanium.The toxicity of ZnO was reduced,and the viability of fibroblasts was largely improved.More importantly,the hydrogel coating provided a good buffer zone for cell ingrowth and soft tissue integration.The curbed Zn ion release was also proved to be useful to regulate fibroblast responses such as the expression of CTGF and COL-I.These results were also validated by in vivo studies.Therefore,this study proposed a valid self-adaptive strategy for ZnO improvement.Under different conditions,the sample could present different functions,and both the antibacterial ability and soft tissue compatibility were finely preserved.
基金supported by the Fundamental Research Funds for the Central Universities (xzy022019014)the National Key R&D Program of China (2018YFC1707700).
文摘Physiological monitoring can provide detailed information about health conditions,and therefore presents great potentials for personalized healthcare.Flexible miniaturized sensors(FMS)for physiological monitoring have garnered significant attention because of their wide applications in collecting health-related information,evaluating and managing the state of human wellness in long term.In this review,we focus on the time scale of human physiological monitoring,the needs and advances in miniaturized technologies for long-term monitoring in typical applications.We also discuss the rational sample sources of FMS to select proper strategies for specific monitoring cases.Further,existing challenges and promising prospects are also presented.
基金supported by the following NIH grants:R01 grants(AR075860,AR077616,and AR083900 to JSHL138175,HL164062,and DK133949 to JG)and a R21 grant(AR077226 to JS)a P30 Core Center grant(AR074992 to the Musculoskeletal Research Center at Washington University in St.Louis).
文摘Critical size bone defects represent a significant challenge worldwide,often leading to persistent pain and physical disability that profoundly impact patients’quality of life and mental well-being.To address the intricate and complex repair processes involved in these defects,we performed single-cell RNA sequencing and revealed notable shifts in cellular populations within regenerative tissue.Specifically,we observed a decrease in progenitor lineage cells and endothelial cells,coupled with an increase in fibrotic lineage cells and pro-inflammatory cells within regenerative tissue.Furthermore,our analysis of differentially expressed genes and associated signaling pathway at the single-cell level highlighted impaired angiogenesis as a central pathway in critical size bone defects,notably influenced by reduction of Spp1 and Cxcl12 expression.This deficiency was particularly pronounced in progenitor lineage cells and myeloid lineage cells,underscoring its significance in the regeneration process.In response to these findings,we developed an innovative approach to enhance bone regeneration in critical size bone defects.Our fabrication process involves the integration of electrospun PCL fibers with electrosprayed PLGA microspheres carrying Spp1 and Cxcl12.This design allows for the gradual release of Spp1 and Cxcl12 in vitro and in vivo.To evaluate the efficacy of our approach,we locally applied PCL scaffolds loaded with Spp1 and Cxcl12 in a murine model of critical size bone defects.Our results demonstrated restored angiogenesis,accelerated bone regeneration,alleviated pain responses and improved mobility in treated mice.
基金G.P.,C.R.S.,and B.P.U.gratefully acknowledge support from the Laboratory Directed Research and Development program of Los Alamos National Laboratory under project#20190043DRLos Alamos National Laboratory is operated by Triad National Security,LLC,for the National Nuclear Security Administration of US Department of Energy(Contract No.89233218CNA000001)+1 种基金S.T.H.and R.M.acknowledge support from the National Science Foundation through DMR-1806147Computational support for this work was provided by LANL’s high-performance computing clusters.
文摘Heteroanionic oxysulfide perovskite compounds represent an emerging class of new materials allowing for a wide range of tunability in the electronic structure that could lead to a diverse spectrum of novel and improved functionalities.Unlike cation ordered double perovskites—where the origins and design rules of various experimentally observed cation orderings are well known and understood—anion ordering in heteroanionic perovskites remains a largely uncharted territory.
基金the National Science Foundation(Grant No.0907090).
文摘The shape memory effect and nanoindentation response of various phases of sputtered NiTi shape memory thin films were investigated as a function of temperature.The phase transformation temperatures of NiTi films were observed to be sensitive to a compositional shift.The mechanical properties of NiTi thin films also presented a significant response to phase transformations.At the same load,the maximum indentation depth for austenite is smaller than for martensite,indicating that martensite is softer than austenite.A martensite thin film was converted to austenite via in situ heating nanoindentation and displayed the mechanical properties similar to the austenite film at room temperature.These results underscore the validity of elevated temperature nanoindentation methods as a means of interrogating the mechanical properties of materials that undergo thermally-induced phase transformations.The details of the load–displacement curves are also described.
基金the Key International Cooperative research of National Natural Science Foundation of China(52120105010)National Natural Science Foundation of China(52179085)+1 种基金the National Key R&D Program Project(2020YFC1512405)the Fifth“333 High-Level Talented Person Cultivating Project”of Jiangsu Province,and Funded projects of“Blue Project”in Jiangsu Colleges and Universities.
文摘To study the influence of an elbow inlet on the rotating stall characteristics of a waterjet propulsion pump(WJPP),a three-dimensional internal flow field in a WJPP under a straight-pipe inlet and elbow inlet is numerically simulated.By comparing the hydraulic performance of WJPP under the two inlet conditions,the internal relationship between the inlet mode and the flow pattern in the pump is clarified.Based on unsteady pressure fluctuation characteristics and wavelet analysis,the influence of the inlet mode on the rotating stall is revealed,and the stall transient propagation characteristics under critical stall conditions are analyzed.The disturbance effects of the inlet channel geometry disappear under low flow rate conditions,the main disturbance is induced by the highspeed countercurrent,and the flow pattern under the elbow inlet is better than that under the straight-pipe inlet.Under the straight-pipe inlet,the single-stall nucleus in the WJPP temporarily experiences a low-frequency and high-amplitude disturbance,which subsequently transforms into a mode of multi-stall nuclei with high-frequency circumferential disturbance.Under the elbow inlet,the rotating stall always maintains a mode of high-amplitude and low-frequency disturbance,which represents the transient characteristics of a single stall core propagating in the circumferential direction inside the channel.The results of this study have a reference value for structural design optimization in a WJPP.
基金supported by a research grant from the Centers for Disease Control and Prevention/National Institute for Occupational Safety and Health (Grant No. R01OH010587)。
文摘Neck injuries are significant causes of morbidity and mortality, and their chronic forms due to repetitive or sustained physical acts(e.g., prolonged use of mobile phone with a dropped head) are becoming increasingly more prevalent. Many injuries are preventable but the prevention and control requires a clear basic understanding of the neck biomechanics. In this paper, we describe a first-of-its-kind study that integrates a gamut of state-of-the-art imaging modalities(dynamic radiography, computed tomography(CT), and magnetic resonance imaging(MRI)) and biodynamic measurements(motion capture, electromyography(EMG), force sensing), thereby investigating holistically the in vivo responses of the neck and its various interconnected musculoskeletal components during functional activities. We present a sample of findings to illustrate how the integrations at multiple levels can enable creating truly subject-specific neck musculoskeletal models and attaining novel insights that otherwise would be unattainable by a singular or subset of approaches.
