检索结果-南通市图书馆

Ultrafast z-scanning for high-efficiency laser micro-machining

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Light(Science & Applications) 2018年第1期7卷 1094-1102页

作者： Ting-Hsuan Chen Romain Fardel craig b arnold Department of Mechanical and Aerospace Engineering and Princeton Institute for the Science and Technology of MaterialsPrinceton UniversityPrincetonNJ 08544USA

High-throughput laser micro-machining demands precise control of the laser beam position to achieve optimal efficiency,but existing methods can be both time-consuming and *** this paper,we demonstrate a new high-throughput micromachining technique based on rapidly scanning the laser focal point along the optical axis using an acoustically driven variable focal length *** results show that this scanning method enables higher machining rates over a range of defocus distances and that the effect becomes more significant as the laser energy is *** a specific example of silicon,we achieve a nearly threefold increase in the machining rate,while maintaining sharp side walls and a small spot *** method has great potential for improving the micro-machining efficiency of conventional systems and also opens the door to applying laser machining to workpieces with uneven topography that have been traditionally difficult to process.

关键词： high-efficiency micro-machining laser material processing TAG lens ultrafast z-scanning

Implications of using two low-power continuous-wave lasers for polishing

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 2020年第3期2卷 174-182页

作者： Wenxuan Zhang Kiwan Wong Miguel Morales Carlos Molpeceres craig b 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 The Hong Kong University of Science and TechnologyHong Kong Centro Laser UPM Universidad Politecnica de MadridAlan Turing 128031MadridSpain Department of Mechanical and Aerospace Engineering Princeton UniversityPrincetonNJ 08544United States of America

Laser polishing is widely employed to reduce the surface roughness of products with complex *** laser polishing techniques use a single high-power Gaussian beam to melt and smooth a thin layer of surface ***,the reliance on high power lasers can present practical challenges such as minimizing surface evaporation or reducing overall *** this work,we combined two identical low-power laser beams with a spatial offset in between them to construct an elliptical *** changing the spatial offset,combined beams with different lengths along the major axis can be *** observe over 20%improvement in line roughness reduction using this approach compared to a single Gaussian laser beam with the same total ***,both experiment and simulation results suggest such improvement is because this dual-laser set-up can create a longer molten pool compared to a single laser.

关键词： laser polishing surface roughness dual lasers low-power

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

在线全文

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

Tinker,tailor,soldier,cell:the role of C-type lectins in the defense and promotion of disease

在线全文

学校读者我要写书评

暂无评论

Protein & Cell 2023年第1期14卷 4-16页

作者： James N.arnold Daniel A.Mitchell School of Cancer and Pharmaceutical Sciences King's College LondonLondon SE11ULUK Warwick Medical School University of WarwickCoventry CV22DXUK

C-type lectins(CTLs)represent a large family of soluble and membrane-bound proteins which bind calcium dependently via carbohydrate recognition domains(CRDs)to glycan residues presented on the surface of a variety of *** deconvolution of a cell’s glycan code by CTLs underpins several important physiological processes in mammals such as pathogen neutralization and opsonization,leukocyte trafficking,and the inflammatory ***,as our knowledge of CTLs has developed it has become apparent that the role of this innate immune family of proteins can be double-edged,where some pathogens have developed approaches to subvert and exploit CTL interactions to promote infection and sustain the pathological ***,CTL interactions with host glycoproteins can contribute to inflammatory diseases such as arthritis and cancer whereby,in certain contexts,they exacerbate inflammation and drive malignant *** review discusses the‘dual agent’roles of some of the major mammalian CTLs in both resolving and promoting infection,inflammation and inflammatory disease and highlights opportunities and emerging approaches for their therapeutic modulation.

关键词： C-type lectins DC-SIGN MbL selectins infection arthritis cancer

Association of Hypertension and Plant-based Dietary Patterns on Cognitive Impairment: A Nationwide Cohort Study in China

在线全文

学校读者我要写书评

暂无评论

Food Science and Human Wellness 2024年

作者： Fang Liang Jialin Fu Gabrielle Turner-McGrievy Yechuang Wang Kai Ding Jing Zeng Justin b Moore Rui Li Chengdu High-tech Zone Center for Diseases Control and Prevention School of Public Health Wuhan University Department of Implementation Science Division of Public Health Sciences Wake Forest School of Medicine Department of Health Promotion Education and behavior arnold School of Public Health University of South Carolina Columbia SC USA School of Nursing Wuhan University

This study investigated the association of hypertension with cognitive impairment and determined whether better adherence to plant-based diet (PbD) patterns may modify the association. We analyzed 4485 elderly individuals with normal cognition at baseline from the Chinese Longitudinal Healthy Longevity Survey (2011-2018). Cognitive function was assessed by the Mini-mental State Examination (MMSE)， and cognitive impairment was defined as an MMSE score below 18 points. Diet patterns were assessed using the overall plant-based diet index (PDI)， healthful plant-based diet index (hPDI)， and unhealthful plant-based diet index (uPDI) derived from a simplified food frequency questionnaire (FFQ). blood pressure was measured through physical examination. Cox proportional hazard regression and restricted cubic spline were performed. Participants with hypertension had an increased risk of cognitive impairment compared with normal group. The associations between hypertension and cognitive impairment were more pronounced among participants with lower PDI than those with higher PDI， among participants with lower hPDI than those with higher hPDI， and among participants with higher uPDI than those with lower uPDI. A healthful PbD pattern may attenuate hypertension-induced cognitive impairment， while an unhealthful PbD pattern may exacerbate hypertension-induced cognitive impairment in elderly. Adherence to healthful PbD pattern could be used to prevent or mitigate adverse neurological effects in the hypertensive population.

关键词：

Cohort study to assess geographical variation in cholangiocarcinoma treatment in England

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastrointestinal Oncology 2023年第12期15卷 2077-2092页

作者： Sophie Jose Amy Zalin-Miller craig Knott Lizz Paley Daniela Tataru Helen Morement Mireille b Toledano Shahid A Khan Health Data Analysis Health Data Insight CICCambridge CB215XEUnited Kingdom National Disease Registration Service National Health Service EnglandLondon SE18UGUnited Kingdom Department of Executive AMMF-The Cholangiocarcinoma CharityEssex CM241QWUnited Kingdom MRC Centre for Environment and Health Imperial College LondonLondon SW72BXUnited Kingdom Mohn Centre for Children's Health and Wellbeing Imperial College LondonLondon SW72BXUnited Kingdom Liver Unit Division of Digestive DiseasesImperial College LondonLondon SW72BXUnited Kingdom

bACKGROUND Outcomes for cholangiocarcinoma(CCA)are extremely poor owing to the complexities in diagnosing and managing a rare disease with heterogenous *** curative surgery,which is only an option for a minority of patients diagnosed at an early stage,few systemic therapy options are currently recommended to relieve symptoms and prolong *** insertion to manage disease complications requires highly specialised *** is lacking as to how CCA patients are managed in a real-world setting and whether there is any variation in treatments received by CCA *** To assess geographic variation in treatments received amongst CCA patients in *** Data used in this cohort study were drawn from the National Cancer Registration Dataset(NCRD),Hospital Episode Statistics and the Systemic Anti-Cancer Therapy Dataset.A cohort of 8853 CCA patients diagnosed between 2014-2017 in the National Health Service in England was identified from the *** curative surgery for all patients and systemic therapy and stent insertion for 7751 individuals who did not receive surgery were identified as three end-points of *** probability models assessed variation in each of the three treatment modalities according to Cancer Alliance of residence at diagnosis,and for socio-demographic and clinical characteristics at *** Of 8853 CCA patients,1102(12.4%)received potentially curative *** mean[95%confidence interval(CI)]percentage-point difference from the population average ranged from-3.96(-6.34 to-1.59)%to 3.77(0.54 to 6.99)%across Cancer Alliances in England after adjustment for patient sociodemographic and clinical characteristics,showing statistically significant *** 7751 who did not receive surgery,1542(19.9%)received systemic therapy,with mean[95%CI]percentage-point difference from the population average between-3.84(-8.04 to 0.35)%to 9.28(1.76 to 16.80)%across Cancer Alliances after adjustm

关键词： Cholangiocarcinoma biliary tract cancer Liver cancer Treatment Surgery Systemic therapy Chemotherapy Stent England

Regional variation in routes to diagnosis of cholangiocarcinoma in England from 2006 to 2017

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 Gastroenterology 2023年第24期29卷 3825-3842页

作者： Amy Zalin-Miller Sophie Jose craig Knott Lizz Paley Daniela Tataru Helen Morement Mireille b Toledano Shahid A Khan Department of Analytics Health Data Insight CICCambridge CB215XEUnited Kingdom Disease Registration Service NHS EnglandLondon E144PUUnited Kingdom CEO AMMFLondon CM241QWUnited Kingdom MRC Centre for Environment and Health School of Public HealthImperial College LondonLondon SW72BXUnited Kingdom Liver Unit Division of Digestive DiseasesImperial College LondonLondon W21NYUnited Kingdom

bACKGROUND Incidence of cholangiocarcinoma(CCA)is rising,with overall prognosis remaining very *** for the high mortality of CCA include its late presentation in most patients,when curative options are no longer feasible,and poor response to systemic therapies for advanced *** presentation presents a large barrier to improving outcomes and is often associated with diagnosis via mergency presentation(EP).Earlier diagnoses may be made by Two Week Wait(TWW)referrals through General practitioner(GP).We hypothesise that TWW referrals and EP routes to diagnosis differ across regions in *** To investigate routes to diagnosis of CCA over time,regional variation and influencing *** We linked patient records from the National Cancer Registration Dataset to Hospital Episode Statistics,Cancer Waiting Times and Cancer Screening Programme datasets to define routes to diagnosis and certain patient characteristics for patients diagnosed 2006-2017 in *** used linear probability models to investigate geographic variation by assessing the proportions of patients diagnosed via TWW referral or EP across Cancer Alliances in England,adjusting for potential *** between the proportion of people diagnosed by TWW referral and EP was investigated with Spearman’s correlation *** Of 23632 patients diagnosed between 2006-2017 in England,the most common route to diagnosis was EP(49.6%).Non-TWW GP referrals accounted for 20.5%of diagnosis routes,13.8%were diagnosed by TWW referral,and the remainder 16.2%were diagnosed via an‘other’or Unknown *** proportion diagnosed via a TWW referral doubled between 2006-2017 rising from 9.9%to 19.8%,conversely EP diagnosis route declined,falling from 51.3%to 46.0%.Statistically significant variation in both the TWW referral and EP proportions was found across Cancer ***,presence of comorbidity and underlying liver disease were independently associated with both a lowe

关键词： Cholangiocarcinoma Route to diagnosis Two Week Wait Emergency presentation Regional variation

Hadron and light nucleus radii from electron scattering

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics C 2022年第12期46卷 1-15页

作者：崔钫 Daniele binosi craig D.Roberts Sebastian M.Schmidt School of Physics Nanjing UniversityNanjing 210093China Institute for Nonperturbative Physics Nanjing UniversityNanjing 210093China European Centre for Theoretical Studies in Nuclear Physics and Related Areas Villa Tambosi Strada delle Tabarelle 286I-38123 Villazzano(TN)Italy Helmholtz-Zentrum Dresden-Rossendorf Dresden D-01314Germany RWTH Aachen University Ⅲ.Physikalisches Institut BAachen D-52074Germany

Conceptually,radii are amongst the simplest Poincaré-invariant properties that can be associated with hadrons and light *** values of these quantities are necessary so that one may judge the character of putative solutions to the strong interaction problem within the Standard ***,limiting their ability to serve in this role,recent measurements and new analyses of older data have revealed uncertainties and imprecisions in the radii of the proton,pion,kaon,and *** the context of radius measurement using electron+hadron elastic scattering,the past decade has shown that reliable extraction requires minimisation of bias associated with practitioner-dependent choices of data fitting *** answers to that challenge have been offered;and this perspective describes the statistical Schlessinger point method(SPM),in unifying applications to proton,pion,kaon,and deuteron *** in analytic function theory,independent of assumptions about underlying dynamics,free from practitioner-induced bias,and applicable in the same form to diverse systems and observables,the SPM returns an objective expression of the information contained in any data under *** robust nature and versatility make it suitable for use in many branches of experiment and theory.

关键词： elastic electromagnetic form factors lepton scattering from hadrons and light nuclei emergence of mass muonic atoms proton Nambu-Goldstone modes-pion and kaon deuteron strong interactions in the standard model of particle physics

Neonatal pneumothorax in congenital diaphragmatic hernia:be wary of high ventilatory pressures

在线全文

学校读者我要写书评

暂无评论

World Journal of Pediatric Surgery 2022年第3期5卷 154-161页

作者： Nathan Rubalcava Gabriella A Norwitz Aimee G Kim Gary Weiner Niki Matusko Meghan A arnold George b Mychaliska Erin E Perrone Pediatric Surgery University of MichiganAnn ArborMichiganUSA Section of Neonatology Department of PediatricsUniversity of MichiganAnn ArborMichiganUSA Department of Surgery University of MichiganAnn ArborMichiganUSA

background Patients with congenital diaphragmatic hernia(CDH)require invasive respiratory support and higher ventilator pressures may be associated with *** sought to evaluate the risk factors associated with pneumothorax in CDH neonates prior to *** Weretrospectivelyreviewednewborns born withCDHbetween 2014and 2019who developeda pneumothorax,and we matched these cases to patients with CDH without *** Twenty-sixpatientswere included(n=13per group).The pneumothorax group required extracorporeal life support(ECLS)more frequently(85%vs 54%,p=0.04),particularly among type A/b defects(31%vs 7%,p=0.01).The pneumothorax group had higher positive end-expiratory pressure(PEEP)within 1 hour of birth(p=0.02),at pneumothorax diagnosis(p=0.003),and at ECLS(p=0.02).The pneumothorax group had a higher mean airway pressure(Paw)at birth(p=0.01),within 1 hour of birth(p=0.01),and at pneumothorax diagnosis(p=0.04).Using multiple logistic regression with cluster robust SEs,higher Paw(OR 2.2,95%Cl 1.08 to 3.72,p=0.03)and PEEP(OR 1.8,95%CI 1.15 to 3.14,p=0.007)were associated with an increased risk of developing *** was no difference in survival(p=0.09).Conclusions Development of a pneumothorax in CDH neonates is independently associated with higher Paw and higher PEEP.A pneumothorax increases the likelihood of treated with ECLS,even with smaller defect.

关键词： PEEP pneumothorax diagnosis