The osteochondral(OC)interface exhibits a mineral gradient,varying in thickness by several hundred micrometers across different species.Disruptions in this interface damage OC tissues,leading to osteoarthritis.The nat...The osteochondral(OC)interface exhibits a mineral gradient,varying in thickness by several hundred micrometers across different species.Disruptions in this interface damage OC tissues,leading to osteoarthritis.The natural architecture and composition of native OC interfaces can be replicated using biomaterial scaffolds via regenerative engineering approaches.A novel one-step bioextrusion process was employed to fabricate a unitary synthetic graft(USG),which mimics the native OC interface’s mineral concentration gradient.This novel USG is composed of an agarose-based cartilage layer and a bone layer,consisting of agarose enriched with 20%(200 g/L)hydroxyapatite.The USG features a gradient interface with mineral concentrations transitioning from 0%to 20%(mass fraction),mimicking the transition between the cartilage and bone.Thermogravimetric analysis revealed that the gradient transition lengths of the graft and native OC tissue harvested from bovine knees were similar((647±21)vs.(633±124)μm).The linear viscoelastic properties of the grafts,which were evaluated using strain sweep and frequency sweep tests with oscillatory shear,indicated a dominant storage modulus over loss modulus similar to that of native OC tissues.The compressive and stress relaxation behaviors of the USGs demonstrated that the graft maintained structural integrity under mechanical stress.Viability assays performed after bioextrusion showed that chondrocytes and human fetal osteoblast cells successfully integrated and survived within their designated regions of the graft.The novel USGs exhibit properties similar to native OC tissue and are promising candidates for regenerating OC defects and restoring knee joint functionality.展开更多
Peptide-based assemblies have gained increasing attention in different areas of nanotechnology,drug delivery and molecular biology.Among these,non-natural β-peptide scaffolds are particularly promising,as their progr...Peptide-based assemblies have gained increasing attention in different areas of nanotechnology,drug delivery and molecular biology.Among these,non-natural β-peptide scaffolds are particularly promising,as their programmable and diverse secondary structures,high metabolic stability and strong self-association propensity can be easily exploited to create variable constructs.We have recently demonstrated that heterochiral,acyclic β^(3)-peptides assembled into striped lamellar nanostructures that induced antibacterial activity.The process of this assembly formation could be exploited in diverse areas,however identifying oligomerisation stages,and more importantly,controlling the spontaneous process at different levels is still lacking.In this study,a set of analogues heterochiral hexameric β^(3)-peptide sequences was investigated to understand how systematic,small variations of the sequences,such as single point mutation or N-terminal chemical modification,can influence the resulting assemblies and allow the control of formed morphologies.TEM and cryo-EM combined with molecular dynamics simulation enabled the identification and differentiation of morphological stages throughout the entire multi-step process.Depending on the position of the sequence modifications,the self-assembled structures formed small oligomers,individual protofibrils,extended,flat lamellae,bundles and macroscopic clusters.These results outline how the self-assembly process of short heterochiral β-peptides can be qualitatively fine-tuned by sequence modifications,which contribute to understanding the general peptide assembly processes for their fibrillar morphologies.展开更多
Using embedded atom method and molecular static relaxation method, the core structure of <100>, <110> edge dislocations, <100> screw dislocation, the interaction between point defects and <100>...Using embedded atom method and molecular static relaxation method, the core structure of <100>, <110> edge dislocations, <100> screw dislocation, the interaction between point defects and <100> edge dislocation in NiAl intermetallics were investigated. The results show that <100>edge dislocation expands along and orientation on the (001) slip plane. The core structure of <100> edge dislocation on (001) plane is like a 'butterfly', while it is very compact when it lies on {110} slip plane. So NiAl will have a <100>{110} slip system in stead of <100>{100} slip system, as experiments showed. <110> edge dislocation has a more expanded core structure and the atoms of dislocation core distort more heavily. None dislocation dissociation was found in the studied dislocations. The outlines of dislocation core structures change very little after a row of point defects are introduced in them, which can be explained by point defects' little effects on the stress field around dislocation core. The results also show that it is hard to change dislocation core structure by decreasing alloy order using the method of introducing limited point defects into the alloy.展开更多
To know well the current situation of the physical health promotion plan implementation in Jinan＇ s middle school students, 240 students and 30 P.E. teachers in Jinan＇ s Shungeng Middle School, Yuying Middle School,...To know well the current situation of the physical health promotion plan implementation in Jinan＇ s middle school students, 240 students and 30 P.E. teachers in Jinan＇ s Shungeng Middle School, Yuying Middle School, Yuxian Middle School, Qixian Middle School, and Shi Liu Li He Middle School were chosen as the research objects. The cognition of these students and teachers on physical health, how to allocate the spare time, how to look upon the relationship between physical exercise and learning, and the physical exercises involved by the students, the grounds for the exercises, the frequency of taking physical exercises, the forms of physical exercises, and the attitude toward physical exercises were investigated and analyzed using questionnaire survey, literature materials, interview, and mathematical statistics research methods. The results showed that most students were very concerned about their own health and willing to build up their body by taking physical exercises and activities, aiming to promote the life and learning quality and physical health; the physical exercise activities involved by the middle school students were various and chosen by students differently. However, some students did not have enough time to take part in physical exercises because of the effect of the factors such as the network. Therefore, the physical health of some students was worrying. The role of school physical education was not fully played. Some schools gave top priority to the enrollment rate, so that P.E. courses were not offered enough, the contents were boring, the class hours of P.E. courses were occupied by literal arts courses, games were limited, and extracurricular team activities were few. Middle school students＇ awareness of physical exercises was not enough; the physical education system from schools was not well- improved; the physical educational plan was unreasonable, so that the students＇ awareness of physical exercises was not cultivated well.展开更多
BACKGROUND Endoscopic bariatric therapies(EBT)have been developed as an adjunctive therapy to treat persistent obesity and recurrent weight gain and dumping symptoms after metabolic and bariatric surgery(MBS).While th...BACKGROUND Endoscopic bariatric therapies(EBT)have been developed as an adjunctive therapy to treat persistent obesity and recurrent weight gain and dumping symptoms after metabolic and bariatric surgery(MBS).While the efficacy of revisional EBTs has been documented,no studies to date have examined how these procedures impact quality of life(QOL)and internalized weight bias(IWB).AIM To understand how endoscopic revisional therapies impact QOL,IWB,and dumping syndrome.METHODS Analysis included 19 participants treated for post-MBS recurrent weight gain and/or dumping syndrome.The short-form 36 survey,weight bias internalization scale,and the Sigstad scoring system were used to measure QOL,IWB,and dumping syndrome pre-and≥4 weeks post-EBT.RESULTS At 6-months,total body weight loss was 8.6%±7.15%(n=16),at 12-months was 13.4%±7.46%(n=16).Short-form 36 scores for all 8 scales significantly increased from pre-to post-procedure with the greatest improvement in the scales related to emotional(mean improvement=59.6,P<0.05)and physical health(mean improvement=31.1,P<0.05).Both total Sigstad score(mean difference=4.947,P<0.05)and total weight bias internalization score(mean difference=0.761,P<0.05)significantly decreased from pre-to post-procedure.CONCLUSION Findings suggest that revisional EBT may improve post-MBS QOL across a broad spectrum of outcomes beyond optimizing body weight.As early EBT results indicate positive mental and physical health outcomes,further research is needed to evaluate the relationship between these improvements,body weight and interdisciplinary post-MBS care.展开更多
Background Biomarkers for predicting suicide risk in hospitalised patients with mental disorders have been understudied.Currently,suicide risk assessment tools based on objective indicators are limited in China.Aims T...Background Biomarkers for predicting suicide risk in hospitalised patients with mental disorders have been understudied.Currently,suicide risk assessment tools based on objective indicators are limited in China.Aims To examine the value of various biomarkers in suicide risk prediction and develop a risk assessment model with clinical utility using machine learning.Methods This cohort study analysed patients with major depressive disorder(MDD) who were hospitalised for the first time between January 2016 and March 2023 from four specialised mental health institutions.A total of 139 features,including biomarker measurements,medical orders and psychological scales,were assessed for analysis.Their suicide risk was evaluated by qualified nurses using Nurse s Global Assessment of Suicide Risk within 1 week after admission.Five machine learning models were trained with 10-fold cross-validation across three hospitals and were externally validated in an independent cohort.The primary performance was assessed using the area under the receiver operating characteristic curve(AUROC).The model was interpreted using the SHapley Additive exPlanations(SHAP) analysis.Biomarker importance was evaluated by comparing model performance with and without these biomarkers.Results Of 3143 patients with MDD included in this study,the incidence of high suicide risk within 1 week after first admission was 660(21.0%).Among all models,the Extreme Gradient Boosting can more effectively predict future risks,with an AUROC higher than 0.8(p<0.001).The SHAP values identified the 10 most important features,including five biomarkers.After clustering analysis,electroconvulsive therapy,physical restraint,β2-microglobulin and triiodothyronine were found to have heterogeneous effects on suicide risk.Combining biomarkers with other data from electronic health records significantly improved the performance and clinical utility of machine learning models based on demographics,diagnosis,laboratory tests,medical orders and psychological scales.Conclusions This study demonstrates the potential for a biomarker-based suicide risk assessment for patients with MDD,emphasising the interaction between biomarkers and therapeutic interventions.展开更多
Background: Musculoskeletal disorders(MSDs) represent a significant global health burden. While physical activity(PA) and physical fitness are both thought to reduce MSD risk, their independent and joint associations ...Background: Musculoskeletal disorders(MSDs) represent a significant global health burden. While physical activity(PA) and physical fitness are both thought to reduce MSD risk, their independent and joint associations with MSD incidence have not been fully explored. This study investigated the independent and combined effects of PA, cardiorespiratory fitness(CRF), grip strength(GS), and GS asymmetry on MSD incidence in a large prospective cohort.Methods: We analyzed data from the UK Biobank cohort(2006-2023), including 406,080 participants aged 37-73 years(age = 55.7 ± 8.2 years,mean ± SD;53.0% female) who were free of MSD at baseline and during the first 2 years of follow-up. PA, derived from self-reported data and expressed in total metabolic equivalent hours per week(MET-h/week);CRF(watts(W)/kilogram(kg)), measured using a cycling exercise test;and GS(kg), measured by hydraulic hand dynamometer, were included as exposures. GS asymmetry was defined by the left-to-right hand strength ratio. MSD incidence was determined via hospital records. Time-to-event associations were analyzed using Cox proportional hazards regression models with restricted cubic splines to account for non-linear relationships. The analysis was conducted in April 2024.Results: Over a median follow-up of 14.7 years, a total of 73,002 incident cases of MSDs were recorded(rheumatoid arthritis: 2923;osteoarthritis:54,955;degenerative spinal diseases: 15,124). Lower self-reported PA(<4.8 MET-h/week) was associated with increased MSD risk(hazard ratio(HR) = 1.0710, 95% confidence interval(95%CI): 1.0623-1.0797). Low CRF(<1.22 W/kg;HR = 1.0941, 95%CI: 1.0596-1.1298), low GS(<27.80 kg;HR = 1.1133, 95%CI: 1.0990-1.1277), and GS asymmetry(HR = 1.1042, 95%CI: 1.0814-1.1274) were also significantly associated with increased MSD risk. Good CRF and GS, and lower GS asymmetry mitigated the higher MSD risk associated with low PA levels.Conclusion: Low levels of PA, CRF, GS, and GS asymmetry were associated with a higher risk of incident MSD. Meanwhile, improvements in CRF, GS, and GS balance could help offset the risk of MSD incidence in populations with insufficient PA.展开更多
The degradation of five naphthalene derivatives in the simulated wastewater was investigated using the iron-carbon micro-electrolysis method.The optimal initial pH of solution and adsorption of iron-carbon and removal...The degradation of five naphthalene derivatives in the simulated wastewater was investigated using the iron-carbon micro-electrolysis method.The optimal initial pH of solution and adsorption of iron-carbon and removal efficiency of the total organic carbon(TOC)were investigated.The results show that the removal efficiency of the naphthalene derivatives can reach 48.9%?92.6% and the removal efficiency of TOC is 42.8%?78.0% for the simulated wastewater with 200 mg/L naphthalene derivatives at optimal pH of 2.0?2.5 after 120 min treatment.The degradation of five naphthalene derivatives with the micro-electrolysis shows the apparent first-order kinetics and the order of removal efficiency of the naphthalene derivatives is sodium 2-naphthalenesulfonate,2-naphthol,2,7-dihydroxynaphthalene,1-naphthamine,1-naphthol-8-sulfonic acid in turn.It is illustrated that the substituents of the naphthalene ring can affect the removal efficiency of naphthalene due to their electron-withdrawing or electron-donating ability.展开更多
Objective:To characterize the expression of aquaporin-4(AQP4),one of the aquaporins(AQPs),in human brainspecimens from patients with traumatic brain injury or brain tumors.Methods:Nineteen hnman brain specimens were o...Objective:To characterize the expression of aquaporin-4(AQP4),one of the aquaporins(AQPs),in human brainspecimens from patients with traumatic brain injury or brain tumors.Methods:Nineteen hnman brain specimens were obtahledfrom the patients with traumatic brain injury,brain tumors,benign meningioma or early stage hemorrhagic stroke.MRI or CTimaging was used to assess brain edema.Hematoxylin and eosm staining were used to evaluate cell damage,Immunohistochem-istry was used to detect the AQP4 expression.Results:AQP4 expression was increased from 15 h to at least 8 d after injury.AQP4immunoreactivity was strong around astrocytomas,ganglioglioma and metastatic adenocarcinoma.However,AQP4 immunore-activity was only found in the centers of astrocytomas and ganglioglioma,but not in metastatic adenocarcinoma derived from lung.Conclusion:AQP4 expression increases in human brains alter traumatic brain injury,within brain-derived tumors,and aroundbrain tumors.展开更多
An experimental study of thermal de-NOx using NH3 as reductant in 02/C02 atmosphere with the effect of S02 and different additives was performed in a drop tube furnace. Results show that the optimum temperature win- d...An experimental study of thermal de-NOx using NH3 as reductant in 02/C02 atmosphere with the effect of S02 and different additives was performed in a drop tube furnace. Results show that the optimum temperature win- dow is 841-1184 ℃, and the optimum reaction temperature is about 900 ℃ with a de-NOx efficiency of 95.4%. A certain amount of S02 has an inhibiting effect on NO reduction. The effect of additives, including Na2C03, C2H5OH and FeCI3, on NO reduction by NH3 is also explored. The addition of Na2CO3 and FeCI3 is useful to widen the tem- perature window and shift the reaction to lower temperature for the efficiency is increased from 30.5% to 74.0% and 67.4% respectively at 800 ℃. Qualitatively, the modeling results using a detailed kinetic modeling mecha- nism represent well most of the process features. The effect of Na2CO3, C2H5OH and FeCI3 addition can be reproduced well by the Na2C03, C2H5OH and Fe（CO）5 sub-mechanism respectively. The reaction mechanism analysis shows that the effects of these additives on NO reduction are achieved mainly by promoting the produc- tion of OH radicals at lower temperature.展开更多
Bismaleimide containing cyanate resin（BMI/CE） pre-ploymer was used as resin matrix. Fluorinated multiwalled carbon nanotubes（F-MWCNTs） were used as fillers to prepare F-MWCNT/BMI/CE nanocomposites via a solution i...Bismaleimide containing cyanate resin（BMI/CE） pre-ploymer was used as resin matrix. Fluorinated multiwalled carbon nanotubes（F-MWCNTs） were used as fillers to prepare F-MWCNT/BMI/CE nanocomposites via a solution intercalation method. The influence of F-MWCNT content on the mechanical, tribological and heat resistant properties of the nanocomposites was investigated. The morphology of the fracture surface and the wear surface of nanocomposites were characterized by scanning electron microscopy.Results show that the addition of F-MWCNTs is beneficial to improving the mechanical and tribological properties of the nanocomposites. It＇s worth noting that when the content of F-MWNTs was 0.6 wt%, the performances of nanocomposite are optimized（i.e., highest impact strength, lowest frictional coefficient and wear rate）. In addition, the nanocomposites exhibit good thermal stability in comparison with BMI/CE.展开更多
The objective of this study was to investigate the feasibility of using a granular activated carbon-biofilm configured packed column system in the deeolodzation of azo dye Acid Orange 7-containing wastewater.The Acid ...The objective of this study was to investigate the feasibility of using a granular activated carbon-biofilm configured packed column system in the deeolodzation of azo dye Acid Orange 7-containing wastewater.The Acid Orange 7-degrading microbial from anaerobic sequencing batch reactor which treating the azo dye-containing wastewater for more than 200 d was immobilized on spent granular activated carbon(GAC)through attachment.The GAC-biofilm configured packed column system showed the ability to decolorize 10...展开更多
AIM:To investigate prescribing pattern in low-dose aspirin users and physician awareness of preventing aspirin-induced gastrointestinal(GI) injury with combined protective medications.METHODS:A retrospective drug util...AIM:To investigate prescribing pattern in low-dose aspirin users and physician awareness of preventing aspirin-induced gastrointestinal(GI) injury with combined protective medications.METHODS:A retrospective drug utilization study was conducted in the 2nd Affiliated Hospital,School of Medicine,Zhejiang University.The hospital has 2300 beds and 2.5 million outpatient visits annually.Data mining was performed on all aspirin prescriptions for outpatients and emergency patients admitted in 2011.Concomitant use of proton-pump inhibitors(PPIs),histamine 2-receptor antagonists(H2RA) and mucoprotective drugs(MPs) were analyzed.A defined daily dose(DDD) methodology was applied to each MP.A further investigation was performed in aspirin users on combination use of GI injurious medicines [non-steoid anti-inflammatory drugs(NSAIDs),corticosteroids and clopidogrel and warfarin] or intestinal protective drugs(misoprostol,rebamipide,teprenone and gefarnate).Data of major bleeding episodes were derived from medical records and adverse drug reaction monitoring records.The annual incidence of major GI bleeding due to low-dose aspirin was estimated for outpatients.RESULTS:Prescriptions for aspirin users receiving PPIs,H2RA and MPs(n = 1039) accounted for only 3.46% of total aspirin prescriptions(n = 30 015).The ratios of coadministration of aspirin/PPI,aspirin/H2RA,aspirin/MP and aspirin/PPI/MP to the total aspirin prescriptions were 2.82%,0.12%,0.40% and 0.12%,respectively.No statistically significant difference was observed in age between patients not receiving any GI protective medications and patients receiving PPIs,H2RA or MPs.The combined medication of aspirin and PPI was used more frequently than that of aspirin and MPs(2.82% vs 0.40%,P < 0.05) and aspirin/H2RA(2.82% vs 0.12%,P < 0.05).The values of DDDs of MPs in descending order were as follows:gefarnate,hydrotalcite > teprenone > sucralfate oral suspension > L-glutamine and sodium gualenate granules > rebamipide > sucralfate chewable tablets.The ratio of MP plus aspirin prescriptions to the total MP prescriptions was as follows:rebamipide(0.47%),teprenone(0.91%),L-glutamine and sodium gualenate granules(0.92%),gefarnate(0.31%),hydrotalcite(1.00%) and sucralfate oral suspension(0.13%).Percentages of prescriptions containing aspirin and intestinal protective drugs among the total aspirin prescriptions were:rebamipide(0.010%),PPI/rebamipide(0.027%),teprenone(0.11%),PPI/teprenone(0.037%),gefarnate(0.017%),and PPI/gefarnate(0.013%).No prescriptions were found containing coadministration of aspirin and other NSAIDs.Among the 3196 prescriptions containing aspirin/clopidogrel,3088(96.6%) prescriptions did not contain any GI protective medicines.Of the 389 prescriptions containing aspirin/corticosteroids,236(60.7%) contained no GI protective medicines.None of the prescriptions using aspirin/warfarin(n = 22) contained GI protective medicines.Thirty-five patients were admitted to this hospital in 2011 because of acute hemorrhage of upper digestive tract induced by low-dose aspirin.The annual incidence rates of major GI bleeding were estimated at 0.25% for outpatients taking aspirin and 0.5% for outpatients taking aspirin/warfarin,respectively.CONCLUSION:The prescribing pattern of low-dose aspirin revealed a poor awareness of preventing GI injury with combined protective medications.Actions should be taken to address this issue.展开更多
We present a series of experimental tests on chemical grouting into a fracture with flowing and static water,using a transparent fracture grouting experimental device.Variations of seepage pressure and grout propagati...We present a series of experimental tests on chemical grouting into a fracture with flowing and static water,using a transparent fracture grouting experimental device.Variations of seepage pressure and grout propagation were compared in our investigation.The results show that flowing water results in drops of seepage pressure,development of penetration radii in the upstream side and drops of propagation area during the same period,compared with grouting in static water.The propagation area in static water is always round before grouts reach the joint boundaries.However,the propagation shape changes from round to an elliptic shape for grouting into a fracture with flowing water.A theoretical model for the grout penetration radius in a fracture considering flowing velocity was developed and validated by our experimental results.These results are helpful in improving understanding of fracture grouting mechanism and in guiding engineering practices.展开更多
The present research has developed a novel investment casting process for ingot production of TiAl alloys through forming a small vertical temperature gradient on the mold.The advantage of this process is to guarantee...The present research has developed a novel investment casting process for ingot production of TiAl alloys through forming a small vertical temperature gradient on the mold.The advantage of this process is to guarantee that the castings solidify sequentially from bottom to top.The analysis of numerical simulation and experimental results showed that the shrinkage porosity of Ti-47Al-2Cr-2Nb alloy was significantly improved by forming a vertical temperature gradient of 3 oC/mm on the mold,while the increase of pouring temperature and pressure on the molten alloys had no apparent effect on the reduction of shrinkage porosity.The critical value of the Niyama criterion that can reliably predict the shrinkage porosity in Ti-47Al-2Cr-2Nb alloy was identified by the comparison of experimental and simulated results.展开更多
Objective:To investigate the physicochemical properties of unripe peach-Pruuns persica cv.Mibaekdo(Mibaekdo) and Prunus persica cv.Nagasawa Hakuho(Nagasawa Hakuho) as an alternative to fowl supplement while Japanese a...Objective:To investigate the physicochemical properties of unripe peach-Pruuns persica cv.Mibaekdo(Mibaekdo) and Prunus persica cv.Nagasawa Hakuho(Nagasawa Hakuho) as an alternative to fowl supplement while Japanese apricot(Prunus mume cv.Backaha)(Backaha) was used as a control sample.Methods:The unripe fruits were analyzed for soluble solid(Brix).titratable acidity.pH,total polyphenol content,1,1-diphenyl-2-pierylhydrazyl(DPPH) radical scavenging activity,amygdalin content,free amino acid content,organic acid content,free sugar content,and α-amylase activities.Results:Total polyphenol content of unripe peach ranged between 137.27-151.64 μg/g whereas that of apricot was 160.73 μg/g.DPPH radical scavenging activities of Rackaha was the highest189.16%.) followed by Mibaekdo(85.03%) and Nagasawa Hakuho(41.30%).The highest amount of oxalic acid 1612.8 mg/100 g) was observed in Mibaekdo while that of Nagasawa llakuho and Backaha were(184.6±18.1) and(334.8±16.1) mg/100 g,respectively.Amygdalin contents of Mibaekdo.Nagasawa Hakuho and Backaha were 486.61,548.60 and 174.28 μg/g,respectively.Conclusions:The results suggest that the unripe fruit of peach has a significant biochemical potential of using as a food supplement with potential health benefit for human health.展开更多
Objective: To study the effect of glycine site/NMDA (N-methyl-D-aspartate) receptor antagonist MRZ2/576 on the conditioned place preference (CPP) and locomotor activity induced by morphine in mice. Methods: Different ...Objective: To study the effect of glycine site/NMDA (N-methyl-D-aspartate) receptor antagonist MRZ2/576 on the conditioned place preference (CPP) and locomotor activity induced by morphine in mice. Methods: Different doses (1.25, 2.5 and 5 mg/kg, i.p.) of MRZ2/576 were used to evaluate the effect of MRZ2/576 on the acquisition and expression of CPP induced by morphine (5 mg/kg) in mice. In addition, we examined the locomotor activity of mice in conditioning and testing phase of CPP paradigm. Results: MRZ2/576 alone could not establish place preference, but a 5 mg/kg dose of MRZ2/576 could block both acquisition and expression of morphine-induced CPP. In testing phase of CPP, there was no statistical difference for locomotor activity between the groups; injection of MRZ2/576 showed a dose-dependent decrease of locomotor activity on both control and morphine-treated mice, especially 5 mg/kg of MRZ2/576 significantly suppressed the locomotor activity of mice. Conclusion: Based on the present results, we assume that MRZ2/576 can antagonize the rewarding effect of morphine, suggesting that this glycine site/NMDA receptor antagonist could be used to treat addictions due to its light side effect profile.展开更多
Fine cellular subgrain structure was formed in the Selective Laser Melting(SLM) manu factured IN718 alloy via optimizing the processing parameters.During the subsequent homogenization heat treatment process,the Laves ...Fine cellular subgrain structure was formed in the Selective Laser Melting(SLM) manu factured IN718 alloy via optimizing the processing parameters.During the subsequent homogenization heat treatment process,the Laves phase dispersed at the subgrain boundaries can be eliminated while the cellular subgrain structure is reserved in the printed samples after holding at 1080℃ for 50 min.With the prolongation of the holding time,the subgrain boundaries undergo low angle rotation via the motion ofdislocation,which leads to the annihilation of the cellular subgrain structure.Moreover,during the subsequent double aging heat treatment process,the reserved cellular subgrain structure in the homogenized samples promotes the precipitation of γ" second phase nanoparticles,and these precipitated γ" phase nanoparticles prefer to distribute at subgrain boundaries.It was found that these unique subgrain boundaries with γ" phase precipitates can hinder but not fully terminate the motion of dislocation during the plastic deformation process,which contributes to increasing the strength as well as holding the stable plastic flow.Hence,the strength and ductility of final prepared IN718 alloy with cellular subgrain microstructure were improved simultaneously compared to the prepared alloy without cellular subgrain structure,which even exceed the mechanical properties standards(AMS 5662) of wrought IN718 alloy.These results in our work suggest that controlling the subgrain structure is a promising effective strategy to improve the mechanical properties of SLM manu factured nickel-based superalloy.展开更多
g-C_(3)N_(4) emerges as a star 2D photocatalyst due to its unique layered structure,suitable band structure and low cost.However,its photocatalytic application is limited by the fast charge recombination and low photo...g-C_(3)N_(4) emerges as a star 2D photocatalyst due to its unique layered structure,suitable band structure and low cost.However,its photocatalytic application is limited by the fast charge recombination and low photoabsorption.Rationally designing g-C_(3)N_(4)-based heterojunction is promising for improving photocatalytic activity.Besides,g-C_(3)N_(4) exhibits great potentials in electrochemical energy storage.In view of the excellent performance of typical transition metal oxides(TMOs)in photocatalysis and energy storage,this review summarized the advances of TMOs/g-C_(3)N_(4) heterojunctions in the above two areas.Firstly,we introduce several typical TMOs based on their crystal structures and band structures.Then,we summarize different kinds of TMOs/g-C_(3)N_(4) heterojunctions,including type Ⅰ/Ⅱ heterojunction,Z-scheme,p-n junction and Schottky junction,with diverse photocatalytic applications(pollutant degradation,water splitting,CO_(2) reduction and N_(2) fixation)and supercapacitive energy storage.Finally,some promising strategies for improving the performance of TMOs/g-C_(3)N_(4) were proposed.Particularly,the exploration of photocatalysis-assisted supercapacitors was discussed.展开更多
Objective： To study the effect of levobupivacaine and bupivacaine on the contractility of isolated uterine muscle strips from pregnant and non-pregnant female rats. Methods： Full-thick myometrial strips were prepare...Objective： To study the effect of levobupivacaine and bupivacaine on the contractility of isolated uterine muscle strips from pregnant and non-pregnant female rats. Methods： Full-thick myometrial strips were prepared from 18- to 2 l-day pregnant （n=8） and non-pregnant rats （n=7）. After contractions became regular, strips were exposed to cumulative concentrations of the two drugs from 10^-8 to 10^-4 mol/L, amplitude and frequency of the uterine contraction was recorded. Results： Two local anesthetics caused a concentration dependent inhibition on contractility of myometrial strips from pregnant and non-pregnant rats. In the myometrium from non-pregnant rats, -log/C50 of levobupivacaine and bupivacaine were 4.85 and 4.25 respectively. In the myometrium from pregnant rats, similar concentrations of levobupivacaine and bupivacaine were observed, -log/C50 were 2.7 and 2.9 respectively. Levobupivacaine produced an increase in amplitude of contractions, while bupivacaine showed an increased trend in frequency. Conclusion： These results demonstrate that levobupivacaine and bupivacaine may inhibit myometrium contractility. The inhibitory effect of levobupivacaine or bupivacaine is not enhanced by gestation in rat. Levobupivacaine may have more positive influence than bupivacaine in pregnant myometrium.展开更多
基金supported by the School of Engineering and Digital Sciences of Nazarbayev University,Astana,Kazakhstan(to CE)。
文摘The osteochondral(OC)interface exhibits a mineral gradient,varying in thickness by several hundred micrometers across different species.Disruptions in this interface damage OC tissues,leading to osteoarthritis.The natural architecture and composition of native OC interfaces can be replicated using biomaterial scaffolds via regenerative engineering approaches.A novel one-step bioextrusion process was employed to fabricate a unitary synthetic graft(USG),which mimics the native OC interface’s mineral concentration gradient.This novel USG is composed of an agarose-based cartilage layer and a bone layer,consisting of agarose enriched with 20%(200 g/L)hydroxyapatite.The USG features a gradient interface with mineral concentrations transitioning from 0%to 20%(mass fraction),mimicking the transition between the cartilage and bone.Thermogravimetric analysis revealed that the gradient transition lengths of the graft and native OC tissue harvested from bovine knees were similar((647±21)vs.(633±124)μm).The linear viscoelastic properties of the grafts,which were evaluated using strain sweep and frequency sweep tests with oscillatory shear,indicated a dominant storage modulus over loss modulus similar to that of native OC tissues.The compressive and stress relaxation behaviors of the USGs demonstrated that the graft maintained structural integrity under mechanical stress.Viability assays performed after bioextrusion showed that chondrocytes and human fetal osteoblast cells successfully integrated and survived within their designated regions of the graft.The novel USGs exhibit properties similar to native OC tissue and are promising candidates for regenerating OC defects and restoring knee joint functionality.
基金funded by the National Research,Development and Inno-vation Office,Hungary(TKP2021-EGA-31,2020-1.1.2-PIACI-KFI-2020-00021,KKP_22 Project no.144180 and FK_23 Project no.146081).Support from Hungarian Research Network(Eötvös Loránd Research Network)grant no.SA-87/2021 and KEP-5/2021 are also acknowledged.Project no.RRF-2.3.1-21-2022-00015+1 种基金supported by the European Union,Recovery and Resilience Facility.The János Bolyai Research Fellowship(A.W.)of the Hungarian Academy of Sciences is greatly acknowledged.The authors acknowledge CF CryoEM of CIISB,Instruct-CZ Centre,supported by Ministry of Education,Youth and Sports,Czech Republic(MEYS CR)(no.LM2023042)European Regional Development Fund-Project"UP CIISB"(n0.CZ.02.1.01/0.0/0.0/18_046/0015974).
文摘Peptide-based assemblies have gained increasing attention in different areas of nanotechnology,drug delivery and molecular biology.Among these,non-natural β-peptide scaffolds are particularly promising,as their programmable and diverse secondary structures,high metabolic stability and strong self-association propensity can be easily exploited to create variable constructs.We have recently demonstrated that heterochiral,acyclic β^(3)-peptides assembled into striped lamellar nanostructures that induced antibacterial activity.The process of this assembly formation could be exploited in diverse areas,however identifying oligomerisation stages,and more importantly,controlling the spontaneous process at different levels is still lacking.In this study,a set of analogues heterochiral hexameric β^(3)-peptide sequences was investigated to understand how systematic,small variations of the sequences,such as single point mutation or N-terminal chemical modification,can influence the resulting assemblies and allow the control of formed morphologies.TEM and cryo-EM combined with molecular dynamics simulation enabled the identification and differentiation of morphological stages throughout the entire multi-step process.Depending on the position of the sequence modifications,the self-assembled structures formed small oligomers,individual protofibrils,extended,flat lamellae,bundles and macroscopic clusters.These results outline how the self-assembly process of short heterochiral β-peptides can be qualitatively fine-tuned by sequence modifications,which contribute to understanding the general peptide assembly processes for their fibrillar morphologies.
文摘Using embedded atom method and molecular static relaxation method, the core structure of <100>, <110> edge dislocations, <100> screw dislocation, the interaction between point defects and <100> edge dislocation in NiAl intermetallics were investigated. The results show that <100>edge dislocation expands along and orientation on the (001) slip plane. The core structure of <100> edge dislocation on (001) plane is like a 'butterfly', while it is very compact when it lies on {110} slip plane. So NiAl will have a <100>{110} slip system in stead of <100>{100} slip system, as experiments showed. <110> edge dislocation has a more expanded core structure and the atoms of dislocation core distort more heavily. None dislocation dissociation was found in the studied dislocations. The outlines of dislocation core structures change very little after a row of point defects are introduced in them, which can be explained by point defects' little effects on the stress field around dislocation core. The results also show that it is hard to change dislocation core structure by decreasing alloy order using the method of introducing limited point defects into the alloy.
文摘To know well the current situation of the physical health promotion plan implementation in Jinan＇ s middle school students, 240 students and 30 P.E. teachers in Jinan＇ s Shungeng Middle School, Yuying Middle School, Yuxian Middle School, Qixian Middle School, and Shi Liu Li He Middle School were chosen as the research objects. The cognition of these students and teachers on physical health, how to allocate the spare time, how to look upon the relationship between physical exercise and learning, and the physical exercises involved by the students, the grounds for the exercises, the frequency of taking physical exercises, the forms of physical exercises, and the attitude toward physical exercises were investigated and analyzed using questionnaire survey, literature materials, interview, and mathematical statistics research methods. The results showed that most students were very concerned about their own health and willing to build up their body by taking physical exercises and activities, aiming to promote the life and learning quality and physical health; the physical exercise activities involved by the middle school students were various and chosen by students differently. However, some students did not have enough time to take part in physical exercises because of the effect of the factors such as the network. Therefore, the physical health of some students was worrying. The role of school physical education was not fully played. Some schools gave top priority to the enrollment rate, so that P.E. courses were not offered enough, the contents were boring, the class hours of P.E. courses were occupied by literal arts courses, games were limited, and extracurricular team activities were few. Middle school students＇ awareness of physical exercises was not enough; the physical education system from schools was not well- improved; the physical educational plan was unreasonable, so that the students＇ awareness of physical exercises was not cultivated well.
文摘BACKGROUND Endoscopic bariatric therapies(EBT)have been developed as an adjunctive therapy to treat persistent obesity and recurrent weight gain and dumping symptoms after metabolic and bariatric surgery(MBS).While the efficacy of revisional EBTs has been documented,no studies to date have examined how these procedures impact quality of life(QOL)and internalized weight bias(IWB).AIM To understand how endoscopic revisional therapies impact QOL,IWB,and dumping syndrome.METHODS Analysis included 19 participants treated for post-MBS recurrent weight gain and/or dumping syndrome.The short-form 36 survey,weight bias internalization scale,and the Sigstad scoring system were used to measure QOL,IWB,and dumping syndrome pre-and≥4 weeks post-EBT.RESULTS At 6-months,total body weight loss was 8.6%±7.15%(n=16),at 12-months was 13.4%±7.46%(n=16).Short-form 36 scores for all 8 scales significantly increased from pre-to post-procedure with the greatest improvement in the scales related to emotional(mean improvement=59.6,P<0.05)and physical health(mean improvement=31.1,P<0.05).Both total Sigstad score(mean difference=4.947,P<0.05)and total weight bias internalization score(mean difference=0.761,P<0.05)significantly decreased from pre-to post-procedure.CONCLUSION Findings suggest that revisional EBT may improve post-MBS QOL across a broad spectrum of outcomes beyond optimizing body weight.As early EBT results indicate positive mental and physical health outcomes,further research is needed to evaluate the relationship between these improvements,body weight and interdisciplinary post-MBS care.
基金supported by projects from Shanghai Putuo District Municipal Health Committee(ptkwws202413)Shanghai Municipal Health Commission(202340018)+2 种基金Shanghai Hospital Development Center(Data Sharing and Emulation of Clinical Trials,CCS-DASET:SHDC2024CRI008)Shanghai Changning District Municipal Commission of Health(CNWJXY026)School of Innovation and Entrepreneurship,Tongji University(S202310247388,X2024085 and X2024048).
文摘Background Biomarkers for predicting suicide risk in hospitalised patients with mental disorders have been understudied.Currently,suicide risk assessment tools based on objective indicators are limited in China.Aims To examine the value of various biomarkers in suicide risk prediction and develop a risk assessment model with clinical utility using machine learning.Methods This cohort study analysed patients with major depressive disorder(MDD) who were hospitalised for the first time between January 2016 and March 2023 from four specialised mental health institutions.A total of 139 features,including biomarker measurements,medical orders and psychological scales,were assessed for analysis.Their suicide risk was evaluated by qualified nurses using Nurse s Global Assessment of Suicide Risk within 1 week after admission.Five machine learning models were trained with 10-fold cross-validation across three hospitals and were externally validated in an independent cohort.The primary performance was assessed using the area under the receiver operating characteristic curve(AUROC).The model was interpreted using the SHapley Additive exPlanations(SHAP) analysis.Biomarker importance was evaluated by comparing model performance with and without these biomarkers.Results Of 3143 patients with MDD included in this study,the incidence of high suicide risk within 1 week after first admission was 660(21.0%).Among all models,the Extreme Gradient Boosting can more effectively predict future risks,with an AUROC higher than 0.8(p<0.001).The SHAP values identified the 10 most important features,including five biomarkers.After clustering analysis,electroconvulsive therapy,physical restraint,β2-microglobulin and triiodothyronine were found to have heterogeneous effects on suicide risk.Combining biomarkers with other data from electronic health records significantly improved the performance and clinical utility of machine learning models based on demographics,diagnosis,laboratory tests,medical orders and psychological scales.Conclusions This study demonstrates the potential for a biomarker-based suicide risk assessment for patients with MDD,emphasising the interaction between biomarkers and therapeutic interventions.
基金supported by research grants from the National Natural Science Foundation of China(No.82001726,82301768)the National Key Research and Development programme of China(No.2024YFC3405800)+3 种基金Chinese Academy of Medical Sciences(CAMS)Innovation Fund for Medical Sciences(No.2019-I2M-5-066)Scientific Research Foundation provided by Pudong Hospital affiliated to Fudan University(No.YJYJRC202202)The Talents Training Program of Pudong Hospital affiliated to Fudan University(No.YQ202201)the Shanghai Municipal Science and Technology Major Project(No.2023SHZDZX02)。
文摘Background: Musculoskeletal disorders(MSDs) represent a significant global health burden. While physical activity(PA) and physical fitness are both thought to reduce MSD risk, their independent and joint associations with MSD incidence have not been fully explored. This study investigated the independent and combined effects of PA, cardiorespiratory fitness(CRF), grip strength(GS), and GS asymmetry on MSD incidence in a large prospective cohort.Methods: We analyzed data from the UK Biobank cohort(2006-2023), including 406,080 participants aged 37-73 years(age = 55.7 ± 8.2 years,mean ± SD;53.0% female) who were free of MSD at baseline and during the first 2 years of follow-up. PA, derived from self-reported data and expressed in total metabolic equivalent hours per week(MET-h/week);CRF(watts(W)/kilogram(kg)), measured using a cycling exercise test;and GS(kg), measured by hydraulic hand dynamometer, were included as exposures. GS asymmetry was defined by the left-to-right hand strength ratio. MSD incidence was determined via hospital records. Time-to-event associations were analyzed using Cox proportional hazards regression models with restricted cubic splines to account for non-linear relationships. The analysis was conducted in April 2024.Results: Over a median follow-up of 14.7 years, a total of 73,002 incident cases of MSDs were recorded(rheumatoid arthritis: 2923;osteoarthritis:54,955;degenerative spinal diseases: 15,124). Lower self-reported PA(<4.8 MET-h/week) was associated with increased MSD risk(hazard ratio(HR) = 1.0710, 95% confidence interval(95%CI): 1.0623-1.0797). Low CRF(<1.22 W/kg;HR = 1.0941, 95%CI: 1.0596-1.1298), low GS(<27.80 kg;HR = 1.1133, 95%CI: 1.0990-1.1277), and GS asymmetry(HR = 1.1042, 95%CI: 1.0814-1.1274) were also significantly associated with increased MSD risk. Good CRF and GS, and lower GS asymmetry mitigated the higher MSD risk associated with low PA levels.Conclusion: Low levels of PA, CRF, GS, and GS asymmetry were associated with a higher risk of incident MSD. Meanwhile, improvements in CRF, GS, and GS balance could help offset the risk of MSD incidence in populations with insufficient PA.
基金Project(05KJD6010110) supported by the Natural Science Foundation of the Education Commission of Jiangsu Province,ChinaProject(2005005) supported by the Science and Technology Foundation of the Environmental Protection Bureau of Jiangsu Province,China
文摘The degradation of five naphthalene derivatives in the simulated wastewater was investigated using the iron-carbon micro-electrolysis method.The optimal initial pH of solution and adsorption of iron-carbon and removal efficiency of the total organic carbon(TOC)were investigated.The results show that the removal efficiency of the naphthalene derivatives can reach 48.9%?92.6% and the removal efficiency of TOC is 42.8%?78.0% for the simulated wastewater with 200 mg/L naphthalene derivatives at optimal pH of 2.0?2.5 after 120 min treatment.The degradation of five naphthalene derivatives with the micro-electrolysis shows the apparent first-order kinetics and the order of removal efficiency of the naphthalene derivatives is sodium 2-naphthalenesulfonate,2-naphthol,2,7-dihydroxynaphthalene,1-naphthamine,1-naphthol-8-sulfonic acid in turn.It is illustrated that the substituents of the naphthalene ring can affect the removal efficiency of naphthalene due to their electron-withdrawing or electron-donating ability.
文摘Objective:To characterize the expression of aquaporin-4(AQP4),one of the aquaporins(AQPs),in human brainspecimens from patients with traumatic brain injury or brain tumors.Methods:Nineteen hnman brain specimens were obtahledfrom the patients with traumatic brain injury,brain tumors,benign meningioma or early stage hemorrhagic stroke.MRI or CTimaging was used to assess brain edema.Hematoxylin and eosm staining were used to evaluate cell damage,Immunohistochem-istry was used to detect the AQP4 expression.Results:AQP4 expression was increased from 15 h to at least 8 d after injury.AQP4immunoreactivity was strong around astrocytomas,ganglioglioma and metastatic adenocarcinoma.However,AQP4 immunore-activity was only found in the centers of astrocytomas and ganglioglioma,but not in metastatic adenocarcinoma derived from lung.Conclusion:AQP4 expression increases in human brains alter traumatic brain injury,within brain-derived tumors,and aroundbrain tumors.
基金Supported by the National Natural Science Foundation of China(51206096)
文摘An experimental study of thermal de-NOx using NH3 as reductant in 02/C02 atmosphere with the effect of S02 and different additives was performed in a drop tube furnace. Results show that the optimum temperature win- dow is 841-1184 ℃, and the optimum reaction temperature is about 900 ℃ with a de-NOx efficiency of 95.4%. A certain amount of S02 has an inhibiting effect on NO reduction. The effect of additives, including Na2C03, C2H5OH and FeCI3, on NO reduction by NH3 is also explored. The addition of Na2CO3 and FeCI3 is useful to widen the tem- perature window and shift the reaction to lower temperature for the efficiency is increased from 30.5% to 74.0% and 67.4% respectively at 800 ℃. Qualitatively, the modeling results using a detailed kinetic modeling mecha- nism represent well most of the process features. The effect of Na2CO3, C2H5OH and FeCI3 addition can be reproduced well by the Na2C03, C2H5OH and Fe（CO）5 sub-mechanism respectively. The reaction mechanism analysis shows that the effects of these additives on NO reduction are achieved mainly by promoting the produc- tion of OH radicals at lower temperature.
基金supported by the Doctorate Foundation of Northwestern Polytechnical University (No. CX201429)the Aerospace Science Foundation of China (No. 2011ZF53064)
文摘Bismaleimide containing cyanate resin（BMI/CE） pre-ploymer was used as resin matrix. Fluorinated multiwalled carbon nanotubes（F-MWCNTs） were used as fillers to prepare F-MWCNT/BMI/CE nanocomposites via a solution intercalation method. The influence of F-MWCNT content on the mechanical, tribological and heat resistant properties of the nanocomposites was investigated. The morphology of the fracture surface and the wear surface of nanocomposites were characterized by scanning electron microscopy.Results show that the addition of F-MWCNTs is beneficial to improving the mechanical and tribological properties of the nanocomposites. It＇s worth noting that when the content of F-MWNTs was 0.6 wt%, the performances of nanocomposite are optimized（i.e., highest impact strength, lowest frictional coefficient and wear rate）. In addition, the nanocomposites exhibit good thermal stability in comparison with BMI/CE.
文摘The objective of this study was to investigate the feasibility of using a granular activated carbon-biofilm configured packed column system in the deeolodzation of azo dye Acid Orange 7-containing wastewater.The Acid Orange 7-degrading microbial from anaerobic sequencing batch reactor which treating the azo dye-containing wastewater for more than 200 d was immobilized on spent granular activated carbon(GAC)through attachment.The GAC-biofilm configured packed column system showed the ability to decolorize 10...
基金Supported by Zhejiang Provincial Bureau of Health,No. 2012KYA090Zhejiang Provincial Bureau of Education, No.20070227
文摘AIM:To investigate prescribing pattern in low-dose aspirin users and physician awareness of preventing aspirin-induced gastrointestinal(GI) injury with combined protective medications.METHODS:A retrospective drug utilization study was conducted in the 2nd Affiliated Hospital,School of Medicine,Zhejiang University.The hospital has 2300 beds and 2.5 million outpatient visits annually.Data mining was performed on all aspirin prescriptions for outpatients and emergency patients admitted in 2011.Concomitant use of proton-pump inhibitors(PPIs),histamine 2-receptor antagonists(H2RA) and mucoprotective drugs(MPs) were analyzed.A defined daily dose(DDD) methodology was applied to each MP.A further investigation was performed in aspirin users on combination use of GI injurious medicines [non-steoid anti-inflammatory drugs(NSAIDs),corticosteroids and clopidogrel and warfarin] or intestinal protective drugs(misoprostol,rebamipide,teprenone and gefarnate).Data of major bleeding episodes were derived from medical records and adverse drug reaction monitoring records.The annual incidence of major GI bleeding due to low-dose aspirin was estimated for outpatients.RESULTS:Prescriptions for aspirin users receiving PPIs,H2RA and MPs(n = 1039) accounted for only 3.46% of total aspirin prescriptions(n = 30 015).The ratios of coadministration of aspirin/PPI,aspirin/H2RA,aspirin/MP and aspirin/PPI/MP to the total aspirin prescriptions were 2.82%,0.12%,0.40% and 0.12%,respectively.No statistically significant difference was observed in age between patients not receiving any GI protective medications and patients receiving PPIs,H2RA or MPs.The combined medication of aspirin and PPI was used more frequently than that of aspirin and MPs(2.82% vs 0.40%,P < 0.05) and aspirin/H2RA(2.82% vs 0.12%,P < 0.05).The values of DDDs of MPs in descending order were as follows:gefarnate,hydrotalcite > teprenone > sucralfate oral suspension > L-glutamine and sodium gualenate granules > rebamipide > sucralfate chewable tablets.The ratio of MP plus aspirin prescriptions to the total MP prescriptions was as follows:rebamipide(0.47%),teprenone(0.91%),L-glutamine and sodium gualenate granules(0.92%),gefarnate(0.31%),hydrotalcite(1.00%) and sucralfate oral suspension(0.13%).Percentages of prescriptions containing aspirin and intestinal protective drugs among the total aspirin prescriptions were:rebamipide(0.010%),PPI/rebamipide(0.027%),teprenone(0.11%),PPI/teprenone(0.037%),gefarnate(0.017%),and PPI/gefarnate(0.013%).No prescriptions were found containing coadministration of aspirin and other NSAIDs.Among the 3196 prescriptions containing aspirin/clopidogrel,3088(96.6%) prescriptions did not contain any GI protective medicines.Of the 389 prescriptions containing aspirin/corticosteroids,236(60.7%) contained no GI protective medicines.None of the prescriptions using aspirin/warfarin(n = 22) contained GI protective medicines.Thirty-five patients were admitted to this hospital in 2011 because of acute hemorrhage of upper digestive tract induced by low-dose aspirin.The annual incidence rates of major GI bleeding were estimated at 0.25% for outpatients taking aspirin and 0.5% for outpatients taking aspirin/warfarin,respectively.CONCLUSION:The prescribing pattern of low-dose aspirin revealed a poor awareness of preventing GI injury with combined protective medications.Actions should be taken to address this issue.
基金Financial support for this work,provided by the National Natural Science Foundation of China(Nos.40772192 and 41072237)the State Key Laboratort of Geomechanics and Deep Underground Engineering(No.SKLGDUEK0903)the Specialized Research Fund for the Doctoral Program of Higher Education of China(No.20100095110015)
文摘We present a series of experimental tests on chemical grouting into a fracture with flowing and static water,using a transparent fracture grouting experimental device.Variations of seepage pressure and grout propagation were compared in our investigation.The results show that flowing water results in drops of seepage pressure,development of penetration radii in the upstream side and drops of propagation area during the same period,compared with grouting in static water.The propagation area in static water is always round before grouts reach the joint boundaries.However,the propagation shape changes from round to an elliptic shape for grouting into a fracture with flowing water.A theoretical model for the grout penetration radius in a fracture considering flowing velocity was developed and validated by our experimental results.These results are helpful in improving understanding of fracture grouting mechanism and in guiding engineering practices.
文摘The present research has developed a novel investment casting process for ingot production of TiAl alloys through forming a small vertical temperature gradient on the mold.The advantage of this process is to guarantee that the castings solidify sequentially from bottom to top.The analysis of numerical simulation and experimental results showed that the shrinkage porosity of Ti-47Al-2Cr-2Nb alloy was significantly improved by forming a vertical temperature gradient of 3 oC/mm on the mold,while the increase of pouring temperature and pressure on the molten alloys had no apparent effect on the reduction of shrinkage porosity.The critical value of the Niyama criterion that can reliably predict the shrinkage porosity in Ti-47Al-2Cr-2Nb alloy was identified by the comparison of experimental and simulated results.
基金Supported by Kyungpook National University Research Fund,2012partly supported by Grants(2012-03)from R&D project to overcome FTA,Free Trade Agreement program 2012 in the agriculture and fishery fields of Gyeongsangbuk-Do province,Korea
文摘Objective:To investigate the physicochemical properties of unripe peach-Pruuns persica cv.Mibaekdo(Mibaekdo) and Prunus persica cv.Nagasawa Hakuho(Nagasawa Hakuho) as an alternative to fowl supplement while Japanese apricot(Prunus mume cv.Backaha)(Backaha) was used as a control sample.Methods:The unripe fruits were analyzed for soluble solid(Brix).titratable acidity.pH,total polyphenol content,1,1-diphenyl-2-pierylhydrazyl(DPPH) radical scavenging activity,amygdalin content,free amino acid content,organic acid content,free sugar content,and α-amylase activities.Results:Total polyphenol content of unripe peach ranged between 137.27-151.64 μg/g whereas that of apricot was 160.73 μg/g.DPPH radical scavenging activities of Rackaha was the highest189.16%.) followed by Mibaekdo(85.03%) and Nagasawa Hakuho(41.30%).The highest amount of oxalic acid 1612.8 mg/100 g) was observed in Mibaekdo while that of Nagasawa llakuho and Backaha were(184.6±18.1) and(334.8±16.1) mg/100 g,respectively.Amygdalin contents of Mibaekdo.Nagasawa Hakuho and Backaha were 486.61,548.60 and 174.28 μg/g,respectively.Conclusions:The results suggest that the unripe fruit of peach has a significant biochemical potential of using as a food supplement with potential health benefit for human health.
基金Project supported by the National Basic Research Program (973) of China (No. 2003CB515402), and the Science and Technology Coun-cil of Zhejiang Province (No. 2005C23G2010166), China
文摘Objective: To study the effect of glycine site/NMDA (N-methyl-D-aspartate) receptor antagonist MRZ2/576 on the conditioned place preference (CPP) and locomotor activity induced by morphine in mice. Methods: Different doses (1.25, 2.5 and 5 mg/kg, i.p.) of MRZ2/576 were used to evaluate the effect of MRZ2/576 on the acquisition and expression of CPP induced by morphine (5 mg/kg) in mice. In addition, we examined the locomotor activity of mice in conditioning and testing phase of CPP paradigm. Results: MRZ2/576 alone could not establish place preference, but a 5 mg/kg dose of MRZ2/576 could block both acquisition and expression of morphine-induced CPP. In testing phase of CPP, there was no statistical difference for locomotor activity between the groups; injection of MRZ2/576 showed a dose-dependent decrease of locomotor activity on both control and morphine-treated mice, especially 5 mg/kg of MRZ2/576 significantly suppressed the locomotor activity of mice. Conclusion: Based on the present results, we assume that MRZ2/576 can antagonize the rewarding effect of morphine, suggesting that this glycine site/NMDA receptor antagonist could be used to treat addictions due to its light side effect profile.
基金National Natural Science Foundation of China (Grant No.51822404 and 51804218)the Science and Technology Program of Tianjin (Grant No.19YFZCGX00790 and 18YFZCGX00070)+1 种基金supported by the Natural Science Foundation of Tianjin (Grant No.18JCYBJC17900)the Seed Foundation of Tianjin University (2018XRX-0005)。
文摘Fine cellular subgrain structure was formed in the Selective Laser Melting(SLM) manu factured IN718 alloy via optimizing the processing parameters.During the subsequent homogenization heat treatment process,the Laves phase dispersed at the subgrain boundaries can be eliminated while the cellular subgrain structure is reserved in the printed samples after holding at 1080℃ for 50 min.With the prolongation of the holding time,the subgrain boundaries undergo low angle rotation via the motion ofdislocation,which leads to the annihilation of the cellular subgrain structure.Moreover,during the subsequent double aging heat treatment process,the reserved cellular subgrain structure in the homogenized samples promotes the precipitation of γ" second phase nanoparticles,and these precipitated γ" phase nanoparticles prefer to distribute at subgrain boundaries.It was found that these unique subgrain boundaries with γ" phase precipitates can hinder but not fully terminate the motion of dislocation during the plastic deformation process,which contributes to increasing the strength as well as holding the stable plastic flow.Hence,the strength and ductility of final prepared IN718 alloy with cellular subgrain microstructure were improved simultaneously compared to the prepared alloy without cellular subgrain structure,which even exceed the mechanical properties standards(AMS 5662) of wrought IN718 alloy.These results in our work suggest that controlling the subgrain structure is a promising effective strategy to improve the mechanical properties of SLM manu factured nickel-based superalloy.
基金financially supported by the National Natural Science Foundation (No.52072347, 51972288, 51672258 and 51572246)the Fundamental Research Funds for the Central Universities (No. 2652019144 and 2652018287)+1 种基金the financial supports from the Science and Technology Program of Guangdong Province (2019A050510012)Shenzhen Science, Technology and Innovation Commission (SGDX2019081623240364).
文摘g-C_(3)N_(4) emerges as a star 2D photocatalyst due to its unique layered structure,suitable band structure and low cost.However,its photocatalytic application is limited by the fast charge recombination and low photoabsorption.Rationally designing g-C_(3)N_(4)-based heterojunction is promising for improving photocatalytic activity.Besides,g-C_(3)N_(4) exhibits great potentials in electrochemical energy storage.In view of the excellent performance of typical transition metal oxides(TMOs)in photocatalysis and energy storage,this review summarized the advances of TMOs/g-C_(3)N_(4) heterojunctions in the above two areas.Firstly,we introduce several typical TMOs based on their crystal structures and band structures.Then,we summarize different kinds of TMOs/g-C_(3)N_(4) heterojunctions,including type Ⅰ/Ⅱ heterojunction,Z-scheme,p-n junction and Schottky junction,with diverse photocatalytic applications(pollutant degradation,water splitting,CO_(2) reduction and N_(2) fixation)and supercapacitive energy storage.Finally,some promising strategies for improving the performance of TMOs/g-C_(3)N_(4) were proposed.Particularly,the exploration of photocatalysis-assisted supercapacitors was discussed.
基金Project (No. 2005038281) supported by the Postdoctor Foundationof China
文摘Objective： To study the effect of levobupivacaine and bupivacaine on the contractility of isolated uterine muscle strips from pregnant and non-pregnant female rats. Methods： Full-thick myometrial strips were prepared from 18- to 2 l-day pregnant （n=8） and non-pregnant rats （n=7）. After contractions became regular, strips were exposed to cumulative concentrations of the two drugs from 10^-8 to 10^-4 mol/L, amplitude and frequency of the uterine contraction was recorded. Results： Two local anesthetics caused a concentration dependent inhibition on contractility of myometrial strips from pregnant and non-pregnant rats. In the myometrium from non-pregnant rats, -log/C50 of levobupivacaine and bupivacaine were 4.85 and 4.25 respectively. In the myometrium from pregnant rats, similar concentrations of levobupivacaine and bupivacaine were observed, -log/C50 were 2.7 and 2.9 respectively. Levobupivacaine produced an increase in amplitude of contractions, while bupivacaine showed an increased trend in frequency. Conclusion： These results demonstrate that levobupivacaine and bupivacaine may inhibit myometrium contractility. The inhibitory effect of levobupivacaine or bupivacaine is not enhanced by gestation in rat. Levobupivacaine may have more positive influence than bupivacaine in pregnant myometrium.
