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排序方式: 共有9091条查询结果,搜索用时 15 毫秒
891.
Saifuddin T. Vohra Edward J. Escott Dale Stevens Barton F. Branstetter 《Neuroradiology》2011,53(2):89-107
Introduction
The apex of the orbit is formed by the union of the lesser and greater wings of the sphenoid bone and acts as an osseous tunnel for numerous neurovascular structures entering the orbit from the cranial vault. Lesions of the orbital apex are clinically important as they can have an adverse effect on vision. A broad range of lesions can occur here, and our purpose is to organize the pathologic processes which occur in the orbital apex into logical imaging differentials, establish an organized approach to image analysis, and present examples of representative lesions. 相似文献892.
Allen J. Norin Mary O. Mondragon-Escorpizo Amarpali Brar David Hochman Nabil Sumrani Dale A. Distant Moro O. Salifu 《Human immunology》2013
The presence of donor specific antibody (DSA) to class 1 or class 2 HLA as detected respectively in T cell or B cell – only flow cytometry cross matches (FCXMs) are risk factors for renal allograft survival, though the comparative risk of these XMs has not been definitively established. Allograft survival and FCXM data in 624 microcytotoxicity (CDC) XM negative kidney transplants were evaluated. Short and long term allograft survival was significantly less in recipients with T− B+ FCXMs (1 year, 74%, 10 year, 58%) compared to T+ B+ FCXMs (1 year, 84%, 10 year, 68%) and to T− B− FCXM (1 year, 90%, 10 year, 85%). Risk factors were positive FCXM, deceased donor (DD) transplantation and donor age, but not race, gender, recipient age or previous transplant. Recipients with T− B+ and T+ B+ FCXMs were at 4.5 and 2.5 fold greater risk, respectively, of DD allograft failure compared to patients with T− B− FCXMs. The quantitative value of FCXM did not correlate with the duration of graft survival. We conclude that patients with DSA to class 2 HLA have a greater risk of early and late allograft failure compared to patients with DSA to class 1 HLA. 相似文献
893.
A study on the impact of catharanthine C10 and C12 indole substituents on the biomimetic Fe(III)-mediated coupling with vindoline led to the discovery and characterization of two new and substantially more potent derivatives, 10'-fluorovinblastine and 10'-fluorovincristine. In addition to defining a pronounced and unanticipated substituent effect on the biomimetic coupling, fluorine substitution at C10', which minimally alters the natural products, was found to uniquely enhance the activity 8-fold against both sensitive (IC(50) = 800 pM, HCT116) and vinblastine-resistant tumor cell lines (IC(50) = 80 nM, HCT166/VM46). As depicted in the X-ray structure of vinblastine bound to tubulin, this site resides at one end of the upper portion of the T-shaped conformation of the tubulin-bound molecule, suggesting the 10'-fluorine substituent makes critical contacts with the protein at a hydrophobic site uniquely sensitive to steric interactions. 相似文献
894.
Wayne K. Davis Peter A. J. Bouhuijs W. Dale Dauphinee Pauline A. McAvoy David A. Alexander Colin Coles 《Teaching and learning in medicine》2013,25(3):130-138
This article examines the research evidence supporting relationships between both personal and social factors and the career choices of physicians in training. Although the research literature in this area is limited by a lack of longitudinal studies, a dependence on cross‐sectional designs, and a lack of multivariate investigations, data support relationships in each of the following areas: sociodemographic characteristics of student, student personality and attitudinal variables, institutional characteristics of the medical school, characteristics of the specialty training programs, and information available to students about the various careers. Additionally, this review investigates the stability of career preferences and career choices over time. 相似文献
895.
Factors influencing general practitioner referrals to a tertiary paediatric neurodisability service.
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This study investigated factors influencing general practitioner (GP) referrals to a tertiary paediatric neurodisability service, including the reasons for referral, the children's characteristics, and the involvement of secondary specialist services in the referral. Fifty general practitioners (GPs) referring consecutively to the Neurodisability Service, Great Ormond Street Hospital for Children, London, were interviewed in a cross-sectional study using a postal questionnaire. The main findings were that two-thirds of the GPs did not contact secondary specialist providers prior to referring. The majority (78%) of GPs were responding to parental concerns in the context of a lack of medical diagnosis in 74% of the children. The main (90%) reason given for referral was for parents seeking a second opinion outside their district network. The findings highlighted the influence of parents over GPs' referrals to tertiary neurodisability, and, in light of this, raised issues for consideration for effective organisation of child disability health services. 相似文献
896.
Robert M. Onorato Dale E. Otten Richard J. Saykally 《Proceedings of the National Academy of Sciences of the United States of America》2009,106(36):15176-15180
Recent experimental and theoretical results have firmly established the existence of enhanced concentrations of selected ions at the air/water interface. Ion adsorption to aqueous interfaces involving complex organic molecules is relevant to biology in connection with the familiar but incompletely understood Hofmeister effects. Here, we describe resonant UV second harmonic generation (SHG) studies of the strongly chaotropic thiocyanate ion adsorbed to the interface formed by water and a monolayer of dodecanol, wherein the Gibbs free energy of adsorption was determined to be −6.7 ± 1.1 and −6.3 ± 1.8 kJ/mol for sodium and potassium thiocyanate, respectively, coincident with the value determined for thiocyanate at the air/water interface. Interestingly, near 4 M and higher concentrations, the resonant SHG signal increases discontinuously, indicating a structural change in the interfacial region. 相似文献
897.
898.
Hans C. Geiss Parhofer Donner Schwandt 《Therapeutic apheresis and dialysis : official peer-reviewed journal of the International Society for Apheresis, the Japanese Society for Apheresis, the Japanese Society for Dialysis Therapy》1999,3(3):199-202
Membrane differential filtration (MDF) is an apheresis technique with which atherogenic lipoproteins can be eliminated from plasma on the basis of particle size. In 52 patients (REMUKAST Study, 1,702 treatments), low density lipoprotein (LDL) cholesterol was decreased by 61%, high density lipoprotein (HDL) cholesterol by 42%, and fibrinogen by 54%. Our own results in 3 patients show decreases of 62%, 31%, and 59%, respectively; lipoprotein (a) (Lp[a]) was reduced by 58%. The elimination of atherogenic lipoproteins was accompanied by a loss of macromolecules (IgM: 55%, IgG: 27%, α2-macroglobulin: 49%) resulting in improved hemorrheologic parameters. Although HDL is eliminated with each apheresis session, pretreatment concentrations of HDL cholesterol increased by 24% during regular apheresis for 1 year (26 patients, REMUKAST Study). However, preapheresis concentrations of other macroglobulins such as immunoglobulins remained decreased compared to concentrations obtained before the first apheresis session (IgM: 34%, IgG: 23%, and IgA: 16%). We conclude that MDF apheresis is an effective method to lower elevated concentrations of atherogenic lipoproteins. The concomitant loss of other macromolecules transiently improves hemorrheology but demands a close monitoring of immunoglobulin concentrations as a safety parameter. 相似文献
899.
David P. Kumamoto Mark Jacob Dale Nickelsen Warren B. Howe 《The Physician and sportsmedicine》2013,41(5):53-54
Sports participation can result in three types of dental trauma: fracture, displacement, and avulsion. On-field physical exam and classification of dentoalveolar injury can expedite referral for definitive treatment. Emergency measures to control bleeding and store avulsed teeth can help preserve dental integrity. Physicians can help prevent dental trauma by promoting mouth guard use. 相似文献
900.