检索结果-南通市图书馆

Dynamics of self-hybridized exciton–polaritons in 2D halide perovskites

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) 2024年第1期13卷 13-22页

作者： Surendra B.Anantharaman Jason Lynch Christopher E.Stevens Christopher Munley Chentao Li Jin Hou Hao Zhang Andrew Torma Thomas Darlington francis Coen Kevin Li Arka Majumdar Pjames Schuck Aditya Mohite Hayk Harutyunyan Joshua R.Hendrickson Deep Jariwala Department of Electrical and Systems Engineering University of PennsylvaniaPhiladelphiaPA19104USA KBR Inc. BeavercreekOH45431USA Air Force Research Laboratory Sensors DirectorateWright-Patterson Air Force BaseOH45433USA Department of Physics University of WashingtonSeattleWA98195USA Department of Physics Emory UniversityAtlantaGA30322USA Department of Chemical and Biomolecular Engineering Rice UniversityHoustonTX77005USA Department of Materials Science and Nanoengineering Rice UniversityHoustonTX77005USA Applied Physics Program Smalley‐Curl InstituteRice UniversityHoustonTX77005USA Department of Mechanical Engineering Columbia UniversityNew YorkNY10027USA Department of Electrical and Computer Engineering University of WashingtonSeattleWA98195USA

Excitons,bound electron–hole pairs,in two-dimensional hybrid organic inorganic perovskites(2D HOIPs)are capable of forming hybrid light-matter states known as exciton-polaritons(E–Ps)when the excitonic medium is confined in an optical *** the case of 2D HOIPs,they can self-hybridize into E–Ps at specific thicknesses of the HOIP crystals that form a resonant optical cavity with the ***,the fundamental properties of these self-hybridized E–Ps in 2D HOIPs,including their role in ultrafast energy and/or charge transfer at interfaces,remain ***,we demonstrate that>0.5µm thick 2D HOIP crystals on Au substrates are capable of supporting multiple-orders of self-hybridized E–P *** E–Ps have high Q factors(>100)and modulate the optical dispersion for the crystal to enhance sub-gap absorption and *** varying excitation energy and ultrafast measurements,we also confirm energy transfer from higher energy E–Ps to lower energy E–***,we also demonstrate that E–Ps are capable of charge transport and transfer at *** findings provide new insights into charge and energy transfer in E–Ps opening new opportunities towards their manipulation for polaritonic devices.

关键词： charge polar excitation

Evaluation of Glycosaminoglycan in the Lumbar Disc Using Chemical Exchange Saturation Transfer MR at 3.0 Tesla:Reproducibility and Correlation with Disc Degeneration

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Biomedical and Environmental Sciences 2016年第1期29卷 47-55页

作者： Deng Min Yuan Jing Chen Wei Tian Queenie Chan james F griffith Wang Yi Xiang Department of Imaging and Interventional Radiology Faculty of MedicineThe Chinese University of Hong KongPrince of Wales HospitalShatinNew TerritoriesHong Kong SAR 999077China Medical Physics and Research Department Hong Kong Sanatorium&HospitalHappy ValleyHong Kong SAR 999077China MR Clinical Science Philips Healthcare Greater ChinaHong Kong SAR 999077 China

Objective This study aims to explore the clinical applicability and relevance of giycosaminoglycan Chemical Exchange Saturation Transfer （gagCEST） for intervertebral disc. Methods 25 subjects ranging in age from 24 yrs to 74 yrs were enrolled, gagCEST was acquired using a single-slice TSE sequence on a 3T. Saturation used a continuous rectangular RF pulse with B1=0.8 I^T and a fixed duration time =1100 ms. Sagittal image was obtained firstly without saturation pulse, and then saturated images were acquired at 52 offsets ranging from ＋0.i25 to ＋_7 parts per million （ppm）. MR T2 relaxivity map was acquired at the identical location. Six subjects were scanned twice to assess scan-rescan reproducibility. Results GagCEST intraclass correlation coefficient （ICC） of six subjects was 0.759 for nucleus pulposus （NP） and 0.508 for annulus fibrosus （AF）. Bland-Altman plots showed NP had a mean difference of 0.10% （95% limits of agreement： -3.02% to 3.22%）; while that of AF was 0.34% （95% limits of agreement： -2.28% to 2.95%）. For the 25 subjects, gag CEST in NP decreased as disc degeneration increased, with a similar trend to T2 relaxivity. Gag CEST of AF showed a better correlation with disc degeneration than T2 relaxivity. Conclusion GagCEST in NP and AF decreased as disc degeneration increased, while gagCEST in AF showed a better correlation than T2 relaxivity.

关键词： Glycosaminoglycan Chemical Exchange Saturation Transfer (CEST) Reproducibility Discdegeneration

Combined risk modelling approach to identify the optimal carotid revascularisation approach

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 2021年第3期6卷 476-482,I0080-I0084页

作者： james francis Burke Lewis B Morgenstern Nicholas H Osborne Rodney A Hayward Neurology University of Michigan Michigan MedicineAnn ArborMichiganUSA Vascular Surgery Univerity of Michigan MedicineAnn ArborMichiganUSA Internal Medicine University of Michigan Michigan MedicineAnn ArborMichiganUSA

Background Carotid endarterectomy(CEA)results in fewer perioperative strokes,but more myocardial infarctions(MI)than carotid artery stenting(CAS).We explored a combined modelling approach that stratifies patients by baseline stroke and *** Baseline registry-based risk models for perioperative stroke and MI were identified via literature *** then selected treatment risk models in the Carotid Revascularisation Stenting versus Endarterectomy(CREST)trial by serially adding covariates(baseline risk,treatment(CEA vs CAS),treatment-risk interaction and age-treatment interaction terms).Treatment risk models were externally validated using data from the Society for Vascular Surgery(SVS)Vascular Quality Initiative(VQI)CEA and carotid stenting registries and treatment models were recalibrated to the SVS-VQI *** net benefit was estimated by summing the predicted stroke and MI risk differences with CEA versus *** Perioperative treatment models had moderate predictiveness(c-statistic 0.69 for stroke and 0.68 for MI)and reasonable calibration across the risk spectrum for both stroke and MI within *** external validation in SVS-VQI,predictiveness was substantially reduced(c-statistic 0.61 for stroke and 0.54 for MI)and models substantially overpredicted *** patients(86.7%)were predicted to have net benefit from CEA in CREST(97.0%of symptomatic patients vs 75%of asymptomatic patients).Discussion A combined modelling approach that separates risk elements has potential to inform optimal ***,our current approach is not ready for clinical *** data support guidelines that suggest that CEA should be the preferred revascularisation modality in most patients with symptomatic carotid stenosis.

关键词： carotid Surgery optimal

Characteristics of Rat Lumbar Vertebral Body Bone Mineral Density and Differential Segmental Responses to Sex Hormone Deficiency:a Clinical Multidetector Computed Tomography Study

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Biomedical and Environmental Sciences 2012年第6期25卷 607-613页

作者： DENG Min WANG Yi Xiang james F. griffith LU Gang Anil T AHUJA POON Wai S Department of Imaging and Interventional Radiology Prince of Wales Hospital the Chinese University of Hong Kong Shatin N.T. Hong Kong China Division of Neurosurgery Department of Surgery Prince of Wales Hospital the Chinese University of Hong Kong Shatin N.T. Hong Kong China

Objective To investigate sex hormone deficiency related osteoporosis and efficacy of different therapies. Methods Orchiectomized and ovariectomized rat models are used to investigate sex hormone deficiency related osteoporosis and efficacy of different therapies. A rat vertebral body can be longitudinally divided into central portion, which contain more trabecular bone, and para-endplate portions which contain more compact bone. In matured male and female Wistar and Sprague-Dawley rat lumbar spines, we investigated baseline bone mineral density （BMD） characteristics and the differential segmental responses in bone loss within the lumbar vertebral body post gonadal surgery with clinical multidetector computed tomography. Results Para-endplate sections had a higher BMD than central sections. The cephalad para-endplate sections had a higher BMD than the caudad para-endplate sections. Eight weeks after gonadal removal, there was more bone loss in central sections than para-endplate sections. The relative difference of bone loss between para-endplate and central sections was more apparent in male rats than in female rats. There was more bone loss in caudad sections than cephalad sections; this lead to a further increase of BMD difference between caudad para-endplate sections and cephalad para-endplate sections post gonadal surgery. Conclusion The approach described in this study provided a consistent way to study BMD change within predominantly compact bone portion and trabecular bone portion of the vertebral body.

关键词： Bone mineral density Quantitative computed tomography, Rat Vertebra Orchiectomy Ovariectomy Cortical bone Trabecular bone

Tissue distribution and tumor uptake of folate receptor–targeted epothilone folate conjugate,BMS-753493,in CD2F1 mice after systemic administration

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

Acta Pharmaceutica Sinica B 2016年第5期6卷 460-467页

作者： Hong Shen Lifei Wang Weiqi Chen Krista Menard Yang Hong Yuan Tian Samuel J.Bonacorsi W.griffith Humphreys francis Y.Lee Jinping Gan Pharmaceutical Candidate Optimization Bristol-Myers Squibb Research & Development Discovery Oncology Bristol-Myers Squibb Research & Development Chemistry Bristol-Myers Squibb Research & Development

To assess targeting of an epothilone folate conjugate(BMS-753493) to the folate receptor(FR)-overexpressed tumor in mice bearing both FRt and FR– tumors,a series of experiments were conducted by quantitative whole-body autoradiography(QWBA) and LC–MS/MS following *** of BMS-753493 or its active moiety,BMS-748285 in mice bearing FRt(98M109) and FR–(M109) *** showed [3H]BMS-753493–derived radioactivity was extensively distributed to various *** FR over-expressing 98M109 tumors showed consistently higher level of radioactivity than FR-negative tumors(i.e.,M109 tumors) up to 48 h post dose of [3H]BMS-753493,despite the magnitude of difference between the tumors is relatively small(generally 3 5-fold).The radioactivity level in 98M109 tumors was 2 12-fold of normal tissues except intestine/content at 48 h post *** selective radioactivity uptake into 98M109 tumors over M109 or normal tissues was observed after *** of the active epothilone,[3H]***–MS/MS measurements demonstrated that the concentrations of BMS-748285,presumably from hydrolysis of the folate conjugate,in 98M109 tumors were greater than those in M109 tumors after *** of BMS-753493(2–3-fold) whereas no differential uptake in the tumors following BMS-748285 *** data were consistent with radioactivity *** results demonstrated that the folate conjugation in BMS-753493 enabled moderately preferential distribution of the active epothilone to FR overexpressing 98M109 tumors,thereby supporting targeted delivery of cytotoxics through the folate receptor.

关键词： Folate receptor Tumor selective targeting Folate receptor–expressing tumor Epothilone folate conjugate Tissue distribution Tumor uptake

Non-invasive MRI assessment of the articular cartilage in clinical studies and experimental settings

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

World Journal of Radiology 2010年第1期2卷 44-54页

作者： james F griffith Anil T Ahuja Department of Diagnostic Radiology and Organ Imaging The Chinese University of Hong KongPrince of Wales HospitalShatinHong KongChina

Attrition and eventual loss of articular cartilage are important elements in the pathophysiology of osteoarthritis(OA).Preventing the breakdown of cartilage is believed to be critical to preserve the functional integrity of a *** injuries are also common in the knee joint,and many patients benefit from cartilage *** resonance imaging(MRI) and advanced digital post-processing techniques have opened possibilities for in vivo analysis of cartilage morphology,structure,and function in healthy and diseased knee *** of semi-quantitative scoring of human knee cartilage pathology and quantitative assessment of human cartilage have been *** thickness and volume have been quantified in humans as well as in small *** detected cartilage loss has been shown to be more sensitive than radiographs detecting joint space *** is possible to longitudinally study knee cartilage morphology with enough accuracy to follow the disease-caused changes and also evaluate the therapeutic effects of chondro-protective *** are also several MRI methods that may allow evaluation of the glycosaminoglycan matrix or collagen network of articular car-tilage,and may be more sensitive for the detection of early *** clinical relevance of these methods is being *** the development of new therapies for OA and cartilage injury,MR images will play an important role in the diagnosis,staging,and evaluation of the effectiveness of these therapies.

关键词： Animal model Cartilage Osteoarthritis Joint space narrowing Knee Magnetic resonance imaging Radiography

Compromised blood flow in osteoporosis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Compromised blood flow in osteoporosis

Structural, densitometric and biomechanical evaluations of Chinese patients with long-term bisphosphonate treatment

第七届国际骨质疏松研讨会暨第五届国际骨矿研究会议

作者： james F griffith Department of Diagnostic Radiology and Organ Imaging Chinese University of Hong Kong

＜正＞Over the past five years,several studies have provided indirect evidence of a link between arterial disease and reduced bone *** example,osteoporosis is a good predictor of subsequent death from a cardiovascular or cerebrovascular event;is strongly associated with aortic calcification and also arterial intimal thickening.

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Chinese Medical Journal 2013年第1期126卷 27-33页

作者： LEUNG Kwok-sui TANG Ning james griffith CHOY Tak-Kee HUNG Vivian Wing-Yin MOK Hoi-Wa SHI Lin LEUNG Ping-Chung CHEUNG Wing-Hoi Department of Orthopaedics and Traumatology and Bone Quality and Health Center The Chinese University of Hong Kong Shatin Hong Kong SAR China Department of Imaging and Interventional Radiology The Chinese University of Hong Kong Shatin Hong Kong SAR China The Jockey Club Center for Osteoporosis Care and Control The Chinese University of Hong Kong Shatin Hong Kong SAR China Orthopaedic Research Laboratory of Translational MedicineResearch and Development Center Institute of Biomedical andHealth Engineering Shenzhen Institutes of Advanced TechnologyChinese Academy of Sciences China

Background The association of long-term bisphosphonate treatment for osteoporosis and related safety problems such as atypical fractures were not clearly defined. This study was to evaluate the structural, densitometric and biomechanical properties of the prolonged bisphosphonate-loaded bones. Methods Bone mineral density （BMD） at hip and femoral midshaft, bone cross-sectional area, moment of inertia of both femurs, bone formation and resorption biochemical markers were compared between 28 elderly with at least 4 years of bisphosphonate treatment from 2002 through 2006 and age-matched group of 37 elderly. Results The total hip BMD and t-score were found not different between two groups. However, bisphosphonate treated patients were found to have significantly lower bone mineral content in the femoral shaft （P 〈0.05）; morphological study showed lower cross-sectional area in subtrochanteric and mid-diaphyseal region and thus significantly lower moment of inertia （P 〈0.01）. High resolution-peripheral quantitative computed tomography showed significantly decreased trabeculardensity, bone volume ratio, trabecular number but increased trabecular spacing in tibia and distal radius. Finite element analysis further confirmed significantly lower stiffness and failure load in tibia. Biochemical studies also showed lower bone resorption and severely suppressed bone formation activity （P 〈0.001）. Conclusions The unchanged total hip BMD between two groups confirmed the beneficial effects of bisphosphonate on trabecular bone, thus preventing osteoporotic fractures at large in previous studies. However, the inferior structural, densitometric and biomechanical properties at cortical bones, especially femur midshaft, need a special attention to look into the association between long-term bisphosphonate intake and the occurrence of stress fractures. When patients taking bisphosphonate complain of proximal thigh pain or discomfort, plain X-ray film can be the first line screening. All

关键词： bisphosphonate bone mineral density moment of inertia HR-pQCT cortical bone

Critical Barriers to Traditional Project Progress Measurement: Perspectives of Ghanaian Construction Professionals

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Building Construction and Planning Research 2020年第2期8卷 119-137页

作者： james Cofie Danku Kofi Agyekum francis Terkpertey Asare Department of Construction Technology and Management Kwame Nkrumah University of Science and Technology Kumasi Ghana GCB Bank Accra Ghana

Accurate project progress measurement is critical for effective project management. Besides guarantying smooth work progress, it affords project managers the chance to identify early warning signs for peremptory remedial actions to keep the project on schedule and to budget. However, pertinent barriers can suppress the realization of the benefits of an accurate assessment of construction progress. This study aims to identify, examine and prioritize the critical barriers militating against accurate project progress measurement in the Ghanaian construction industry. Sixteen barriers identified from the literature were administered in a questionnaire survey to professionals with tier one construction firms and consultants. Sixty experienced construction professionals practising with tier-one construction firms and consultancy services took part in the survey. The relative importance index technique was used to rank the factors and correlation in responses of the two parties tested by the Mann-Whitney U statistics. The most critical barriers perceived by the professionals were 1) Reliance on Supervisor’s Judgement, 2) Generic and Non-Systematic Approach, 3) Variable Quality of Data and 4) Intricate Measurement Reports. Other highly ranked barriers include 5) Lack of Timely Information, 6) Laborious Data Gathering and 7) Quality Integration Constraint. The findings underpin the need to minimize dependence on subjective opinions and mere experiences of supervisors for assessment of project progress in this age of information technology. Incorporation of a level of automation into traditional progress methods will not only reduce human errors introduced into manually collected data but facilitate visualization of progress reports. Contiguous to a clear specification of the method of progress measurement in the contract document, a system that conveniently integrates cost, time and scope of work into progress measurement must be pursued. Addressing these identified

关键词： Project Progress Measurement Critical Barriers Construction Professionals Traditional Methods Ghana