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排序方式: 共有771条查询结果,搜索用时 15 毫秒
81.
P.N SANDERSON R.C GLEN A.W.R PAYNE B.D. HUDSON C HEIDE GE TRANTER PM DOYLE CJ HARRIS 《Chemical biology & drug design》1994,43(6):588-596
The solution conformation of a cyclic RGD peptide analogue, cyclo-(S,S)-2-merrcaptobenzoate-arginine-glycine-aspartate -2-mercaptoanilide, has been determined via two independent approaches for the searching of conformational space and identification of conformations consistent with NMR and CD spectroscopic data: (i) the use of a binary genetic algorithm and (ii) a molecular dynamics simulation. Inter-proton distances were obtained via analysis of cross-peak volumes from a two-dimensional ROESY NMR spectroscopy experiment at 600 MHz and were used as constraints for the computational calculations. The mercaptoanilide amide proton resonance chemical shift had a very small temperature coefficient, indicating that this proton was hydrogen-bonded. Circular diehroism data showed that, in solution, the torsion angle about the disulfide bond was negative, consistent with one of the distinct conformations around this bond in the 200 ps molecular dynamics simulation. The backbone conformations of the structures resulting from the two different approaches were very similar. 相似文献
82.
83.
CA Buckley FRACO FRACS FRCS CJ Buckley J Griffiths DOBA 《Clinical & experimental ophthalmology》1997,25(2):111-116
Purpose: To establish whether; in a well-informed population, the use of extended wear disposable soft contact lenses (EWDSCL) poses an unacceptable risk to vision and corneal health due to complications associated with their use. Methods: A 4 year retrospective review of EWDSCL, involving 371 patients in Melbourne from a single general ophthalmology practice. The important aspects of this group were that all patients were given written instructions about the methods of ensuring initial and ongoing cleanliness of lenses, no lenses were cleaned and reinserted, and no solutions other than the saline in the original packaging, and comfort drops, were used. Two types of EWDSCL were used, in powers from - 9.0 to + 6.0 D, and with an initial aim of 4 weeks uninterrupted extended wear. Follow-up was from 2 to 52 months, with an average of 24 months. Results: Of the 354 patients followed up, 236 (66%) regularly wore them on an extended overnight basis, and of these 180 (76%) wore them for the suggested 4 week period before renewal of lenses. In the 471 eyes of 236 patients, adverse reactions occurred at the following rates: marginal infiltrates (12 cases, 2.5%); corneal oedema (10 cases, 2%); peripheral corneal vascularization (2 cases, 0.4%); and presumed infective keratitis (1 case, 0.2%). No eyes lost one or more lines of Snellen acuity. Conclusions: When disposable soft contact lenses do not come into contact with cleaning solutions, saline from bottles or aerosol cans, or storage cases, their use on an extended wear basis (up to 4 weeks continuous) appears to be associated with a low risk of minor or major complications. The results of this review indicate that controlled usage of EWDSCL is safer than previous reports have indicated. 相似文献
84.
CJ Keith M Griffiths B Petersen RJ Anderson KA Miles 《Journal of Medical Imaging and Radiation Oncology》2002,46(3):221-230
The development of thrombolytic and neuroprotective agents for the treatment of acute stroke has created an imperative for improved imaging techniques in the assessment of acute stroke. Five cases are presented to illustrate the value of perfusion CT in the evaluation of suspected acute stroke. To obtain the perfusion data, a rapid series of images was acquired without table movement following a bolus of contrast medium. Cerebral blood flow, cerebral blood volume and mean transit time were determined by mathematically modelling the temporal changes in contrast enhancement in the brain and vascular system. Pixel‐by‐pixel analysis allowed generation of perfusion maps. In two cases, CT‐perfusion imaging usefully excluded acute stroke, including one patient in whom a low‐density area on conventional CT was subsequently proven to be tumour. Cerebral ischaemia was confirmed in three cases, one with an old and a new infarction, one with a large conventional CT abnormality but only a small perfusion defect, and one demonstrating infarct and penumbra. Perfusion CT offers the ability to positively identify patients with non‐haemorrhagic stroke in the presence of a normal conventional CT, to select those cases where thrombolysis is appropriate, and to provide an indication for prognosis. 相似文献
85.
Cell interaction with three-dimensional sharp-tip nanotopography 总被引:2,自引:0,他引:2
Cells in their native microenvironment interact with three-dimensional (3D) nanofeatures. Despite many reports on the effects of substrate nanotopography on cells, the independent effect of 3D parameters has not been investigated. Recent advances in nanofabrication for precise control of nanostructure pattern, periodicity, shape, and height enabled this systematic study of cell interactions with 3D nanotopographies. Two distinct nanopatterns (posts and grates) with varying three-dimensionalities (50-600 nm in nanostructure height) were created, while maintaining the pattern periodicity (230 nm in pitch) and tip shape (needle- or blade-like sharp tips). Human foreskin fibroblasts exhibited significantly smaller cell size and lower proliferation on needle-like nanoposts, and enhanced elongation with alignment on blade-like nanogrates. These phenomena became more pronounced as the nanotopographical three-dimensionality (structural height) increased. The nanopost and nanograte architectures provided the distinct contact guidance for both filopodia extension and the formation of adhesion molecules complex, which was believed to lead to the unique cell behaviors observed. 相似文献
86.
The clinical spectrum of postpartum thyroid disease 总被引:1,自引:0,他引:1
Lazarus JH; Hall R; Othman S; Parkes AB; Richards CJ; McCulloch B; Harris B 《QJM : monthly journal of the Association of Physicians》1996,89(6):429-435
The clinical and biochemical features of postpartum thyroid disease were
analysed in 152 antithyroid peroxidase antibody-positive (anti TPO+ve)
women and compared with 239 anti-TPO-ve age-matched control postpartum
women. All were assessed monthly for up to 12 months postpartum. Seventy
three anti-TPO+ve women developed post-partum thyroiditis (PPT): 19.2%
hyperthyroid alone, 49.3% hypothyroid alone, and 31.5% characterized by
hyper- followed by hypothyroidism. None of the antibody-negative women
developed any thyroid dysfunction. A significant increase in many of eleven
symptoms of hypothyroidism and some of eight symptoms of hyperthyroidism
compared to control women was observed in all anti-TPO+ve women,
independent of thyroid status. This was particularly seen in women who
later developed PPT when they were euthyroid, but was also observed in
euthyroid anti-TPO+ve women who showed no decline of thyroid function
during the postpartum period. Although PPT is usually transient, this
condition, and the euthyroid antibody-positive state, may be associated
with significant symptomatology, including an increased incidence of minor
to moderate depression. Early recognition of this syndrome by antenatal
screening of thyroid antibodies may contribute to improved management of
women during the postpartum period.
相似文献
87.
In human immune deficiency virus (HIV)-seropositive hemophilia patients, a low number of CD4 + lymphocytes is found, as well as a low CD4+/CD8+ ratio. In previous studies, it has been shown that antigen- specific T-helper cell (CD4+) function was present and no excessive antigen-specific T-suppressor cell (CD8+) function could be demonstrated. In this report, we studied another activity of CD4+ cells, namely the capacity to induce T-suppressor cell activity. The results clearly show a selective dysfunction of CD4+ suppressor-inducer (Tsi) cell function. Since these HIV-seropositive hemophilia patients showed the presence of activated B cells in the peripheral circulation refractory to antigen-specific T-helper cell signals and secreting specific antibodies spontaneously, we raised the hypothesis that the activated B cells in the patients activate the Tsi cells in vivo. This constant activation leads to a functional exhaustion of the Tsi cell pool. 相似文献
88.
Occupational violence (OV) is a daily risk for ED staff. It contributes to staff stress, sick leave, turn‐over and burn‐out, and limits the capacity of staff to provide unimpeded quality care to patients and their families. Many factors contribute to incidents of OV; however, early detection of such risk factors could pre‐empt incidences of OV during ED episodes of care. A five‐stage methodological framework for scoping reviews was used to identify, summarise and synthesise OV risk factors from five key databases. A validated tool was used to appraise the quality of included studies. Independent evaluation by the reviewers was used throughout. Patient factors were extracted and described from 24 methodologically and geographically diverse papers. Methodological quality for these studies varied from moderate to high. A total of 34 OV risk factors were identified. Although there was variation in, and differences between, staff‐perceived and objective (documented) OV risk factors, patient risk factors can be categorised into three main groups: clinical presentation, behaviours and past history. Five existing ED OV risk assessment tools were identified, with limited supporting evidence for each. The results support the development of a reliable and validated OV risk assessment tool to be initiated at triage. 相似文献
89.
This case report discusses the unusual presentation and ultrasound features of a solitary fibrous tumour of the face. Solitary fibrous tumour is an uncommon form of soft tissue tumour which, although seen predominantly within the lung pleura, can occur throughout the body in sites such as the peritoneum, mediastinum and head and neck. Ultrasound is an excellent imaging modality in the assessment of soft tissue masses in the head and neck. The ultrasound features demonstrated by this example of solitary fibrous tumour are reviewed. This report also highlights that ultrasound alone is ultimately limited in reaching a definitive diagnosis. The roles of other investigations such as ultrasound-guided biopsy and cross-sectional imaging are discussed. 相似文献
90.
cDNA recombinant plasmid complementary to mRNAs for light chains 1 and 3 of mouse skeletal muscle myosin. 总被引:5,自引:2,他引:5 下载免费PDF全文
B Robert A Weydert M Caravatti A Minty A Cohen P Daubas F Gros M Buckingham 《Proceedings of the National Academy of Sciences of the United States of America》1982,79(8):2437-2441
A recombinant plasmid with a cDNA sequence transcribed from mouse skeletal muscle RNA is shown to hybridize with mRNAs for myosin light chains LC1F and LC3F. The inserted fragment corresponds exclusively to the 3'-noncoding region of the mRNA. It hybridizes almost exclusively with the two light chain messengers from fast skeletal muscle RNA of adult mouse. Slight hybridization is seen with RNA from heart muscle and embryonic skeletal muscle. The implications of the conservation of the 3'-noncoding regions between the two mRNAs are discussed. 相似文献