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排序方式: 共有164条查询结果,搜索用时 15 毫秒
91.
Damian S. Nakonieczny Grayna Simha Martynkov Marianna Hundkov Gabriela Kratoov Sylva Holeov Jana Kupkov Lenka Pazourkov Justyna Majewska 《Materials》2022,15(4)
The alumina and zirconia surfaces were pretreated with chemical etching using alkaline mixtures of ammonia, hydrogen peroxide and sodium hydroxide, and followed with application of the powder layer of Ca-deficient hydroxyapatite (CDH). The influence of etching bath conditions time and concentration on surface development, chemical composition and morphology of medicinal ceramic powders were studied. The following analyses were performed: morphology (scanning electron microscopy), phase composition (X-ray diffraction analysis), changes in binding interactions and chemical composition (FT-Infrared and Energy dispersive spectroscopies). Both types of etchants did not expose the original phase composition changes or newly created phases for both types of ceramics. Subsequent decoration of the surface with hydroxyapatite revealed differences in the morphological appearance of the layer on both ceramic surfaces. The treated zirconia surface accepted CDH as a flowing layer on the surface, while the alumina was decorated with individual CDH aggregates. The goal of this study was to focus further on the ceramic fillers for polymer-ceramic composites used as a biomaterial in dental prosthetics. 相似文献
92.
Anita Gross Jordan Miller Jonathan D’Sylva Stephen J. Burnie Charles H. Goldsmith Nadine Graham Ted Haines Gert Brønfort Jan L. Hoving 《Manual therapy》2010,15(4):315-333
Manipulation and mobilisation are often used, either alone or combined with other treatment approaches, to treat neck pain. This review assesses if manipulation or mobilisation improves pain, function/disability, patient satisfaction, quality of life (QoL), and global perceived effect (GPE) in adults experiencing neck pain with or without cervicogenic headache or radicular findings. A computerised search was performed in July 2009. Randomised trials investigating manipulation or mobilisation for neck pain were included. Two or more authors independently selected studies, abstracted data, and assessed methodological quality. Pooled relative risk (pRR) and standardised mean differences (pSMD) were calculated. 33% of 27 trials had a low risk of bias. Moderate quality evidence showed cervical manipulation and mobilisation produced similar effects on pain, function and patient satisfaction at intermediate-term follow-up. Low quality evidence suggested cervical manipulation may provide greater short-term pain relief than a control (pSMD ?0.90 (95%CI: ?1.78 to ?0.02)). Low quality evidence also supported thoracic manipulation for pain reduction (NNT 7; 46.6% treatment advantage) and increased function (NNT 5; 40.6% treatment advantage) in acute pain and immediate pain reduction in chronic neck pain (NNT 5; 29% treatment advantage). Optimal technique and dose need to be determined. 相似文献
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With the focus on imaging, this paper gives a summarized view of the present knowledge on fields, which are necessary to know for a profound understanding of congenital malformations of the external and middle ear. Typical and less typical combinations of malformed parts of the ear can be derived from the embryogenesis. Clinical signs and audiometric findings lead to diagnosis in congenital aural atresia. Isolated middle ear malformations can be clinically mixed up especially with otosclerosis and tympanosclerosis. Imaging is needed for exact morphological information. In malformations of the external and middle ear, CT is the imaging modality of choice. Requirements on CT-technique as well as radiological findings including classification and pre-surgical rating are described. Morphological CT-correlates of congenital malformations and their differential diagnoses are enlisted and illustrated. The impact of CT-results on therapy is explained and actual therapeutic concepts are briefly presented. 相似文献
96.
C. R. German A. Bowen M. L. Coleman D. L. Honig J. A. Huber M. V. Jakuba J. C. Kinsey M. D. Kurz S. Leroy J. M. McDermott B. Mercier de Lépinay K. Nakamura J. S. Seewald J. L. Smith S. P. Sylva C. L. Van Dover L. L. Whitcomb D. R. Yoerger 《Proceedings of the National Academy of Sciences of the United States of America》2010,107(32):14020-14025
Thirty years after the first discovery of high-temperature submarine venting, the vast majority of the global mid-ocean ridge remains unexplored for hydrothermal activity. Of particular interest are the world’s ultraslow spreading ridges that were the last to be demonstrated to host high-temperature venting but may host systems particularly relevant to prebiotic chemistry and the origins of life. Here we report evidence for previously unknown, diverse, and very deep hydrothermal vents along the ∼110 km long, ultraslow spreading Mid-Cayman Rise (MCR). Our data indicate that the MCR hosts at least three discrete hydrothermal sites, each representing a different type of water-rock interaction, including both mafic and ultramafic systems and, at ∼5,000 m, the deepest known hydrothermal vent. Although submarine hydrothermal circulation, in which seawater percolates through and reacts with host lithologies, occurs on all mid-ocean ridges, the diversity of vent types identified here and their relative geographic isolation make the MCR unique in the oceans. These new sites offer prospects for an expanded range of vent-fluid compositions, varieties of abiotic organic chemical synthesis and extremophile microorganisms, and unparalleled faunal biodiversity—all in close proximity. 相似文献
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98.
Daniel Maekawa Sylva M. Riblet Linnea Newman Rik Koopman Taylor Barbosa 《Avian pathology》2019,48(6):573-581
ABSTRACTThe chicken embryo origin (CEO) infectious laryngotracheitis (ILT) live attenuated vaccines, although capable of protecting against disease and reducing challenge virus replication, can regain virulence. Recombinant ILT vaccines do not regain virulence but are partially successful at blocking challenge virus replication. The objective of this study was to evaluate the effect of rHVT-LT vaccination on CEO replication and how this vaccination strategy enhances protection and limits challenge virus transmission to naïve contact chickens. The rHVT-LT vaccine was administered at 1 day of age subcutaneously and the CEO vaccine was administered at 6 weeks of age via eye-drop or drinking water. CEO vaccine replication post vaccination, challenge virus replication and transmission post challenge were evaluated. After vaccination, only the group that received the CEO via eye-drop developed transient conjunctivitis. A significant decrease in CEO replication was detected for the rHVT-LT?+?CEO groups as compared to groups that received CEO alone. After challenge, reduction in clinical signs and challenge virus replication were observed in all vaccinated groups. However, among the vaccinated groups, the rHVT-LT group presented higher clinical signs and challenge virus replication. Transmission of the challenge virus to naïve contact chickens was only observed in the rHVT-LT vaccinated group of chickens. Overall, this study found that priming with rHVT-LT reduced CEO virus replication and the addition of a CEO vaccination provided a more robust protection than rHVT alone. Therefore, rHVT-LT?+?CEO vaccination strategy constitutes an alternative approach to gain better control of the disease. 相似文献
99.
R E Friedrich S Bartel-Friedrich K Plambeck 《Journal of oral and maxillofacial surgery》2000,58(10):1125-1128
PURPOSE: This study investigated the distribution of collagen III and IV in experimental microvascular anastomoses and correlated the findings with the quality of the healing process. MATERIALS AND METHODS: A previously excised and reanastomosed section of the left common carotid artery of 21 female Wistar rats were explanted 4 weeks after surgery. Collagens III and IV were identified in perfusion-fixed specimens by immunohistochemistry. RESULTS: The identification and distribution of collagens reflected the quality of each suturing procedure. A myointimal hyperplasia was present, extending into the vascular lumen, and was closely related to the ends of the vessel segments. The extent of myointimal hyperplasia was dependent on the length and the vitality of the vessel segments. The media was the weakest part of the tissue layers with regard to regenerative potential in the axial direction. The marked cuff of the adventitia around the anastomosis was rich in collagen III-positive vasa vasorum. Collagen IV was distributed in net-like patterns in the media. The distribution pattern in the media was not observed in anastomoses with incomplete approximation and necrotic segment ends. The collagen IV-positive subendothelial basal membrane was incomplete in the aneurysms because of partial necrosis. CONCLUSIONS: The experimental findings support the need for atraumatic suturing in microvascular surgery. Immunohistochemical detection of collagens can be a valuable tool for studying the basic processes of wound healing and the integration of microvascular flaps into their recipient sites. 相似文献
100.
The mixed dissociation constants of four non-steroidal anti-inflammatory drugs (NSAIDs) ibuprofen, diclofenac sodium, flurbiprofen and ketoprofen at various ionic strengths I of range 0.003-0.155, and at temperatures of 25 degrees C and 37 degrees C, were determined with the use of two different multiwavelength and multivariate treatments of spectral data, SPECFIT/32 and SQUAD(84) nonlinear regression analyses and INDICES factor analysis. The factor analysis in the INDICES program predicts the correct number of components, and even the presence of minor ones, when the data quality is high and the instrumental error is known. The thermodynamic dissociation constant pK(a)(T) was estimated by nonlinear regression of (pK(a), I) data at 25 degrees C and 37 degrees C. Goodness-of-fit tests for various regression diagnostics enabled the reliability of the parameter estimates found to be proven. PALLAS, MARVIN, SPARC, ACD/pK(a) and Pharma Algorithms predict pK(a) being based on the structural formulae of drug compounds in agreement with the experimental value. The best agreement seems to be between the ACD/pK(a) program and experimentally found values and with SPARC. PALLAS and MARVIN predicted pK(a,pred) values with larger bias errors in comparison with the experimental value for all four drugs. 相似文献