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排序方式: 共有172条查询结果,搜索用时 31 毫秒
1.
E Gilbert A Morel M Tulliez R Maunoury F Terzi L Miquerol A Kahn 《Canadian Metallurgical Quarterly》1997,73(5):749-756
PURPOSE: The clinical significance of isolated calf vein thrombosis (CVT), particularly with respect to development of the postthrombotic syndrome, remains controversial. The purpose of this study was to define the early natural history of CVT in relation to persistent lower extremity symptoms, propagation, recanalization, and the development of valvular incompetence. METHODS: Over a 116-month period, 499 patients with acute deep venous thrombosis (DVT) were referred to our research laboratory, of whom 58 (12%) had thrombosis confined to the calf veins of at least one extremity. The lower extremities of 268 patients (29 with isolated CVT) were followed-up clinically and with duplex ultrasonography at intervals of 1 day, 7 days, 1 month, every 3 months for the first year, and yearly thereafter. RESULTS: Seventy percent of extremities with CVT were symptomatic at presentation. Although the prevalence of clinical signs and symptoms decreased to 29% by 1 month, 23% of patients had persistent pain, edema, or both at 12 months. In contrast, 9% of uninvolved extremities contralateral to a CVT and 54% of extremities with proximal DVT remained symptomatic at 1 year (p = 0.004). Recanalization proceeded rapidly such that the mean thrombus load was reduced by 50% at 1 month and to zero at 1 year. The prevalence of valvular incompetence progressively increased such that reflux was present in 24% of extremities at 1 year. Although its investigation was not a primary goal of this study, pulmonary embolism was diagnosed at presentation and during follow-up in 11% and 3% of patients, respectively. CONCLUSIONS: The natural history of CVT is complicated by persistent symptoms and the development of valvular incompetence in approximately one-quarter of patients. This potential for persistent lower extremity symptoms should be considered in evaluating the clinical relevance of isolated calf vein DVT. 相似文献
2.
MA Kuzu C K?ksoy IT Kale A Tanik C Terzi AH Elhan 《Canadian Metallurgical Quarterly》1998,176(4):348-351
This SAEM position paper clarifies the role of emergency medicine in health care delivery. It builds upon the working definition of emergency medicine developed by the American College of Emergency Physicians in 1994 by describing the health care role of emergency physicians (EPs). EPs are first-contact providers who care for all patients regardless of age, gender, time of presentation, or ability to pay. They remain the only continuously accessible specialty for patients seeking help and solace in the health care system. They are an essential link in the health care continuum between primary care physicians, specialists, the out-of-hospital system, the patient, inpatient services, and communication services. The EP's role is in organizing and monitoring the emergency care delivery system. Part of this role is to better align the health care provider training and ability with the specific medical needs of a patient. The emergency health care system remains the essential medical safety net for all individuals needing care in this country. 相似文献
3.
Duanka Vasovi Djordje Stojakovi Slavica Stankovi 《Journal of the American Ceramic Society》1987,70(1):23-C-
The use of BPO4 in the synthesis of crystalline AlPO4 has been investigated. The best results are obtained if BPO4 and hydrated alumina are heated in molten KCl: at 1050°C the conversion degree of BPO4 into AlPO4 is >90% (in 4 h). The product consists of the tridymite AlPO4 form. 相似文献
4.
Pavements constructed for the purpose of meeting the demand of highways which were emerged with the improving technological developments increased. And consequently, more resources were demanded to be directed to pavement maintenance and rehabilitation. Hereby, the concept of pavement management emerged. Although project-level analyses were found adequate previously, network-level evaluations were needed in order to do detailed planning as a result of resource allocation and transfer problems that were emerged later. Therefore, pavement management system has become compulsory for all pavements to be controlled together. In this framework, programming is needed in order to schedule maintenance–rehabilitation and develop costs with respect to budget. In the study carried out, a mode was developed in order to program the routine network maintenance activities in terms of Pavement Maintenance and Management Systems, and it was concluded that this problem can be solved through ant colony, using Visual Basic. 相似文献
5.
Slavica Marinovi? Tomislav Bolan?a ?ime Uki? Vinko Rukavina Ante Juki? 《Chemistry and Technology of Fuels and Oils》2012,48(1):67-74
In this paper, two neural networks, multilayer perceptron and networks with radial-basis function, were used to predict important
cold properties of commercial diesel fuels, namely cloud point and cold filter plugging point. The developed models predict
the named properties using cetane number, density, viscosity, contents of total aromatics, and distillation temperatures at
10, 50, and 90 vol. % recovery as input data. The training algorithms, number of hidden layer neurons, and number of training
data points were optimized in order to obtain a model with optimal predictive ability. The results indicated better prediction
of cloud and cold filter plugging points in the case of multilayer perceptron networks. The obtained absolute error mean for
the optimal neural network models (0.58°C for the cloud point and 1.46°C for the cold filter plugging point) are within the
range of repeatability of standard cold properties determination methods. 相似文献
6.
W. H. Sillekens D. J. Jarvis A. Vorozhtsov V. Bojarevics C. F. Badini M. Pavese S. Terzi L. Salvo L. Katsarou H. Dieringa 《Metallurgical and Materials Transactions A》2014,45(8):3349-3361
The performance of structural materials is commonly associated with such design parameters as strength and stiffness relative to their density; a recognized means to further enhance the weight-saving potential of low-density materials is thus to improve on their mechanical attributes. The European Community research project ExoMet that started in mid-2012 targets such high-performance aluminum- and magnesium-based materials by exploring novel grain refining and nanoparticle additions in conjunction with melt treatment by means of external fields (electromagnetic, ultrasonic, and mechanical). These external fields are to provide for an effective and efficient dispersion of the additions in the melt and their uniform distribution in the as-cast material. The consortium of 27 companies, universities, and research organizations from eleven countries integrates various scientific and technological disciplines as well as application areas—including automotive, aircraft, and space. This paper gives an overview of the project, including its scope for development and organization. In addition, exemplary results are presented on nanoparticle production and characterization, mixing patterns in metal melts, interface reactions between metal and particles, particle distribution in the as-cast composite materials, and mechanical properties of the as-cast composite materials. The application perspective is considered as well. 相似文献
7.
8.
Aysel Kantürk Figen Evren Terzi Nural Yilgör Saip Nami Kartal Sabriye Pişkin 《Korean Journal of Chemical Engineering》2013,30(4):878-890
hermal degradation characteristics of Tetra Pak panel boards (TPPB) can be useful to improve usage of such panels as an alternative to wood-based products such as plywood, fiberboard, and particleboard. In the study, samples from the TPBBs manufactured from waste Tetra Pak packages (WTPP) were heated in a nitrogen atmosphere at different heating rates (10, 15 and 20 °C/min) using a thermal analysis system. The Coats-Redfern kinetic model was applied to calculate kinetic parameters. The degradation rate equations were then established. In addition, the kinetic compensation effect (KCE) was used to correlate the pre-exponential factor (k o ) with activation energy (E a ) and the existence of the KCE was accepted. TG-FT/IR analyses were applied to the TPPB degradation and then the FT-IR stack plot was used to analyze gas products (CO2, CH4, HCOOH, and CH3OH). Infrared vibrational frequencies and the micro, crystal structure of the TPPBs were investigated by Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscope (SEM) and X-Ray diffraction analysis (XRD), respectively. 相似文献
9.
A solid phase extraction technique for sample cleanup and extraction of α-tocopherol and α-tocopheryl acetate is described and applied to their simultaneous HPLC analysis in dairy products, plant-based milks, infant formulas, and pharmaceutical colostrum. The proposed method includes sample pretreatment by using ethanol, followed by solid-phase extraction of the organic supernatant on C18 cartridges. The identification and quantification were done by reversed-phase HPLC with fluorescence detection (ex 295 nm, em 330 nm) for tocopherol and with UV detector set at 220 nm for tocopheryl acetate. The mobile phase consisted of 100% acetonitrile. The linear ranges were from 0.02–0.40 μg/mL (dairy products) and 0.50–5.00 μg/mL (plant milks, infant formulas, powdered products) for α-tocopherol and those of α-tocopheryl acetate were from 0.20–2.00 μg/mL (dairy products) and 1.00–10.0 μg/mL (plant milks, infant formulas, powdered products). The LOD and LOQ of α-tocopherol were 0.1 and 0.4 μg/mL, while those of the α-tocopheryl acetate were 2.0 μg/mL for LOD and 6.0 μg/mL for LOQ. The method gave extraction recoveries from 73–94% with RSDs values being 5–10%. This method is simple, SPE procedure is fast and HPLC analysis time is less than 10 min. The total time of performing analysis per sample is less than 1 h. The important advantage of the proposed method is the capability of determining and reporting α-tocopherol and α-tocopheryl acetate separately. Moreover, the developed method is suitable for fast screening of the synthetic form of vitamin E in dairy products, plant-based milks, infant formulas, and pharmaceutical colostrum. 相似文献
10.
Valentina V Semenčenko Ljiljana V Mojović Aleksandra P Đukić‐Vuković Milica M Radosavljević Dušanka R Terzić Marija S Milašinović Šeremešić 《Journal of the science of food and agriculture》2013,93(4):811-818
BACKGROUND: Bioethanol is mostly produced from starchy parts of the corn grain kernel leaving significant amounts of valuable by‐products such as dried distillers' grains with solubles (DDGS) which can be used as a substitute for traditional feedstuff. The suitability of six maize hybrids from Serbia was investigated for bioethanol and DDGS production. The correlation between physical and chemical characteristics of the grain, bioethanol yield and quality of the corresponding DDGS was assessed. RESULTS: All hybrids had very different chemical composition and physical characteristics which could allow various applications. The highest bioethanol yield (94.5% of theoretical) and volumetric productivity (2.01 g l?1 h?1) were obtained with hybrid ZP 434 and the lowest with ZP 611k. Regarding chemical composition, all DDGS samples manifested good properties as feed components. Their protein content was higher compared to the kernel. In addition, the samples showed high digestibility and high mineral content, especially of calcium and phosphorus. CONCLUSION: A hybrid ZP 434 was selected as the most promising bioethanol producer. This property is attributed to the highest level of soft endosperm which is more susceptible to starch‐hydrolysing enzymes. A high yield potential per hectare makes it the best candidate for commercial bioethanol production. © 2012 Society of Chemical Industry 相似文献