检索结果-南通市图书馆

Understanding the Rayleigh instability in humping phenomenon during laser powder bed fusion process

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Extreme manufacturing 2022年第1期4卷 85-92页

作者： Wenxuan Zhang Wenyuan Hou Luc Deike craig Arnold Department of Chemical and Biological Engineering Princeton UniversityPrincetonNJ 08544United States of America Princeton Institute for the Science and Technology of materials Princeton UniversityPrincetonNJ 08544United States of America Department of mechanical and Aerospace Engineering Princeton UniversityPrincetonNJ 08544United States of America High meadows Environmental Institute Princeton UniversityPrincetonNJ 08544United States of America

The periodic undulation of a molten track’s height profile in laser-based powder bed fusion of metals(PBF-LB/m)is a commonly observed phenomena that can cause defects and building failure during the manufacturing *** a quantitative analysis of such instabilities has not been fully established and so here we used Rayleigh–Plateau theory to determine the stability of a single molten track in PBF-LB/m and tested it with various processing conditions by changing laser power and beam *** analysis discovered that normalized enthalpy,which relates to energy input density,determines whether a molten track is initially unstable and if so,the growth rate for the ***,whether the growth rate ultimately yields significant undulation depends on the melt duration,estimated by dwell time in our experiment.

关键词： additive manufacturing powder bed fusion dual lasers undulation humping

Adélie penguins and temperature changes in Antarctica: a long-term view

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Integrative Zoology 2012年第2期7卷 113-120页

作者： craig D.mILLAR Sankar SUBRAmANIAN Tim H.HEUPINK Siva SWAmINATHAN Carlo BARONI David m.LAmBERT Allan Wilson Centre for molecular Ecology and Evolution University of Auckland Griffith School of Environment and School of Biomolecular and Physical Sciences Griffith UniversityAustralia Environment Protection Training and Research Institute HyderabadIndia Department of Earth Sciences University of PisaPisaItaly

During the summer months,Adélie penguins represent the dominant biomass of terrestrial *** millions of individuals nest in ice-free areas around the coast of the ***,these modern populations of Adélie penguins have often been championed as an ideal biological indicator of ecological and environmental changes that we currently *** addition,Adélie penguins show an extraordinary record of sub-fossil remains,dating back to the late *** this time,temperatures were much lower than ***,this species offers unique long-term information,at both the genomic and ecological levels,about how a species has responded to climate change over more than 40000 years.

关键词： Adélie penguins climate change global warming penguin evolution

Should Athletes Stretch before Exercise?

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

中国运动医学杂志 2007年第5期26卷 626-633页

作者： Karl B.Fields craig m.Burnworth martha Delaney Director of Family medicine Residency and Sports medicine Fellowship moses Cone Health System GreensboroNC MD Professor and Associate Chairman Department of Family MedicineUniversity of North Carolina Sports medicine Fellow Moses Cone Health SystemGreensboroNC Associate Team PhysicianElon UniversityElonNC MD Administrative Director Greensboro Area Health Education Center Research CoordinatorMoses Cone Family Medicine Residency GreensboroNC MA

KEY POINTSTraditional stretching routines performed during warm-up procedures before exercise can increase flexibility for a short time,but there is little scientific evidence that such routines can improve exercise performance,reduce delayed-onset muscular soreness,or prevent *** on a regular basis,e.g.,3-5 days/week,away from the exercise environment may be effective in improving flexibility and some types of exercise performance,and it may reduce injury risk,but further research is required to validate this *** stretching for 15-30 seconds is more effective for increasing flexibility than stretching for shorter durations and is equally effective as stretching for longer periods.

关键词：运动伸展训练热身运动肌肉酸痛运动损伤

monitoring film coalescence from aqueous polymeric dispersions using atomic force microscopy: Surface topographic and nano-adhesion studies

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Asian Journal of Pharmaceutical Sciences 2020年第1期15卷 104-111页

作者： Ziyi Yang Duncan Qmcraig School of Pharmaceutical Science Jiangnan University1800 Lihu RoadWuxi 214122China UCL School of Pharmacy 29-39 Brunswick SquareLondon WC1N1AXUK

The aim of the investigation was to develop the use of topographic and nano-adhesion atomic force microscopy(AFm) studies as a means of monitoring the coalescence of latex particles within films produced from a pharmaceutically relevant aqueous dispersion(Eudragit~?NE30 D). Films were prepared via spin coating and analysed using AFm, initially via tapping mode for topographic assessment followed by force-distance measurements which allowed assessment of site-specific adhesion. The results showed that colloidal particles were clearly observed topographically in freshly prepared samples, with coalescence detected on curing via the disappearance of discernible surface features and a decrease in roughness indices. The effects of temperature and humidity on film curing were also studied, with the former having the most pronounced effect. AFm force measurements showed that the variation in adhesive force reduced with increasing curing time, suggesting a novel method of quantifying the rate of film formation upon curing. It was concluded that the AFm methods outlined in this study may be used as a means of qualitatively and quantitatively monitoring the curing of pharmaceutical films as a function of time and other variables, thereby facilitating rational design of curing protocols.

关键词： Film curing Atomic force microscopy Spin coating Aqueous dispersion AFm pull-off force measurement

No benefit of flat head positioning in early moderate-severe acute ischaemic stroke: a HeadPoST study subgroup analysis

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Stroke & Vascular Neurology 2020年第4期5卷 406-409页

作者： Alejandro m Brunser menglu Ouyang Hisatomi Arima Pablo m Lavados Thompson Robinson Paula munoz-Venturelli Veronica V Olavarria Laurent Billot marre L Hackett Lili Song Sandy middleton Octavio Pontes-Neto Tsong-Hai lee Caroline Watkins craig S Anderson Department of General Emergency Clinica Alemana de SantiagoClinica Alemana Universidad del DesarrolloSantiagoChile Department of Neurology and Psychiatry Clinica Alemana de SantiagoFaculty of MedicineClinica Alemana Universidad del DesarrolloSantiagoChile The George Institute for Global Health University of New South WalesSidneyNew South WalesAustralia The George Institute in China Peking University Health Science CenterBeijingChina Department of Preventive medicine and Public Health Fukuoka UniversityFukuokaJapan Department of Cardiovascular Sciences and NIHR Leicester Biomedical Research Centre University of LeicesterLeicesterUnited Kingdom Faculty of Health and Wellbeing University of Central LancashirePrestonLancashireUnited Kingdom Nursing Research Institute St Vincent's Health Network Sydney AustraliaAustralian Catholic UniversitySydneyNew South WalesAustralia Stroke Service-Neurology Division Department of Neuroscience and Behavioral SciencesRibeirao Preto Medical SchoolUniversity of Sao PauloSao PauloBrazil Stroke Center and Department of Neurology Linkou Chang Gung Memorial Hospital and College of MedicineChang Gung UniversityTaoyuanTaiwan

background Although the Head Positioning in acute Stroke Trial(HeadPoST)showed no effect of the flat head position(FP;vs sitting up head position(SUP))on functional outcome,we hypothesised that it could still offer benefits if commenced early in those with acute ischaemic stroke(AIS)of at least moderate *** Subgroup analysis of HeadPoST in participants with National Institutes of Health Stroke Scale(NIHSS)scores≥7,≥10 and≥14,randomised to FP or SUPmes defined by a shift in scores on the modified Rankin scale(mRS)and death/disability(mRS scores 3-6),and any cardiovascular serious adverse *** regression analyses were undertaken adjusted for study design and baseline risk *** There was no significant differential treatment effect in patient subgroups defined by increasing baseline NIHSS scores:adjusted OR and 95%CI for ordinal shift and binary(3-6)mRS scores:for NIHSS≥7(n=867)0.92(0.67 to 1.25)and 0.74(0.52 to 1.04);NIHSS≥10(n=606)0.80(0.58 to 1.10)and 0.77(0.49 to 1.19);NIHSS≥14(n=378)0.82(0.54 to 1.24)and 1.22(0.69 to 2.14).Conclusions Early FP had no significant effect in patients with moderate-severe AIS.

关键词： acute analysis effect

Targeted genotyping for the prediction of celiac disease autoimmunity development in patients with type 1 diabetes and their family members

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Diabetes 2019年第3期10卷 189-199页

作者： maureen m Leonard Stephanie Camhi Victoria Kenyon Rebecca A Betensky craig Sturgeon Shu Yan Alessio Fasano mucosal Immunology and Biology Research Center Mass General Hospital for Children Boston MA 02115 United States Center for Celiac Research and Treatment Mass General Hospital for Children Boston MA 02115 United States Department of Pediatric Gastroenterology and Nutrition Mass General Hospital for Children Boston MA 02114 United States Department of Biostatistics Harvard T.H. Chan School of Public Health Boston MA 02115 United States

BACKGROUND Patients with type 1 diabetes (T1D) and their first-degree relatives (FDRs) have an increased risk of developing celiac disease (CD) compared to the general population. This is largely explained by the shared association with major histocompatibility class II human leukocyte antigen (HLA) DQ2 and/or DQ8 between the two disease states. AIm To describe the frequency of CD autoimmunity (CDA) and the distribution of HLA and haptoglobin genotypes in patients with T1D and their FDRs. Additionally, we aimed at identifying predictors associated with an increased risk of developing CDA in patients with T1D and their family members. mETHODS We obtained clinical information and blood samples from 1027 participants (302 with T1D and 725 FDRs) over a five-year period. Samples were tested for autoantibodies associated with CD, HLA-DQ alleles, and haptoglobin *** fit univariate and multiple logistic regression models for CDA separately for subjects with T1D and for FDRs of subjects with T1D. RESULTS Implementation of a screening program increased the frequency of CDA by 2- fold in participants with T1D and 2.8-fold in their FDRs. multivariate analysis found that, in participants with T1D, having both DR7-DQ2 and DR4-DQ8 was associated with an increased frequency of CDA. In FDRs of T1D patients, reported CD in the family was associated with an increased frequency of CDA during screening. Haptoglobin 2 genotype was not associated with developing CDA in the multivariate analysis. CONCLUSION Patients with T1D and their FDRs have a high frequency of CDA. Carrying both DR7-DQ2 and DR4-DQ8 was associated with development of CDA in patients with T1D.

关键词： Screening Gluten Diabetic Coeliac Haptoglobin Human leukocyte antigen

Analysis of a ten step protocol to decrease postoperative spinal wound infections

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Orthopedics 2018年第11期9卷 271-284页

作者： Hossein Elgafy craig J Raberding megan L mooney Kyle A Andrews Joan m Duggan Department of Orthopedics and Infectious Diseases University of Toledo Medical Center

AIm To define a ten-step protocol that reduced the incidence of surgical site infection in the spine surgery practice of the senior author and evaluate the support for each step based on current *** In response to unexplained increased infection rates at our institution following spine surgery,a ten-step protocol was implemented:(1) preoperative glycemic management based on hemoglobin A1 c(HbA1 c);(2) skin site preoperative preparation with 2% chlorhexidine gluconate disposable cloths;(3) limit operating room traffic;(4) cut the number of personnel in the room to the minimum required;(5) absolutely no flash sterilization of equipment;(6) double-gloving with frequent changing of outer gloves;(7) local application of vancomycin powder;(8) re-dosing antibiotic every 4 h for prolonged procedures and extending postoperative coverage to 72 h for high-risk patients;(9) irrigation of subcutaneous tissue with diluted povidone-iodine solution after deep fascial closure; and(10) use of Dura Prep skin preparation at the end of a case before skin closure. Through an extensive literature review,the current data available for each of the ten steps was *** Use of vancomycin powder in surgical wounds,routine irrigation of surgical site,and frequent changing of surgical gloves are strongly supported by the literature. Preoperative skin preparation with chlorhexidine wipes is similarly supported. The majority of current literature supports control of HbA1 c preoperatively to reduce risk of infection. Limiting the use of flash sterilization is supported,but has not been evaluated in spine-specific surgery. Limiting OR traffic and number of personnel in the OR are supported although without level 1 evidence. Prolonged use of antibiotics postoperativelyis not supported by the literature. Intraoperative use of Dura Prep prior to skin closure is not yet *** The ten-step protocol defined herein has significantly helped in decreasing surgical site

关键词： Wound infections Spine Ten step protocol Surgical site infections

management of distal humeral coronal shear fractures

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2015年第5期3卷 405-417页

作者： Shahram S Yari Nathan L Bowers miguel A craig lee m Reichel Baylor College of medicine Medical School One Baylor Plaza Houston TX 77030 United States Baylor College of medicine Department of Orthopedic Surgery Ben Taub General Hospital Houston TX 77030 United States

Coronal shear fractures of the distal humerus are rare,complex fractures that can be technically challenging to manage. They usually result from a low-energy fall and direct compression of the distal humerus by the radial head in a hyper-extended or semi-flexed elbow or from spontaneous reduction of a posterolateral subluxation or dislocation. Due to the small number of soft tissue attachments at this site, almost all of these fractures are displaced. The incidence of distal humeral coronal shear fractures is higher among women because of the higher rate of osteoporosis in women and the difference in carrying angle between men and women. Distal humeral coronal shear fractures may occur in isolation, may be part of a complex elbow injury, or may be associated with injuries proximal or distal to the elbow. An associated lateral collateral ligament injury is seen in up to 40% and an associated radial head fracture is seen in up to 30% of these fractures. Given the complex nature of distal humeral coronal shear fractures, there is preference for operative management. Operative fixation leads to stable anatomic reduction, restores articular congruity, and allows initiation of early range-of-motion movements in the majority of cases. Several surgical exposure and fixation techniques are available to reconstruct the articular surface fol owing distal humeral coronal shear fractures. The lateral extensile approach and fixation with countersunk headless compression screws placed in an anterior-to-posterior fashion are commonly used. We have found a two-incision approach(direct anterior and lateral) that results in less soft tissue dissection and better outcomes than the lateral extensile approach in our experience. Stiffness, pain, articular incongruity, arthritis, and ulnohumeral instability may result if reduction is non-anatomic or if fixation fails.

关键词： Coronal Shear Fractures Distal Humerus management Approach Two-incision

Surgical Anatomy Around the Orbit: The System of Zones: A Continuation of Surgical Anatomy of the Orbit by Barry m. Zide and Glenn W. Jelks

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论