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排序方式: 共有287条查询结果,搜索用时 15 毫秒
1.
Anna I. Suvorova Lyudmila Yu. Demchik Aza L. Peshekhonova Olga A. Sdobnikova 《Macromolecular chemistry and physics.》1993,194(5):1315-1321
The phase equilibrium of plasticized polymer systems on the basis of cellulose diacetate and ethylene glycol esters of dibasic aliphatic acids (from oxalic acid to 1,10-decanedicarboxylic acid) was studied and the solubility parameters and the thermodynamic interaction parameters of the components were calculated. It is shown that an increase in molecular weight of the plasticizers leads to a lower miscibility of the components, a fact which is reflected in a regular rise of the upper critical solution temperature (UCST), a tendency of the systems for gelation, a decrease of the solubility parameter of the plasticizer δ1, and a growth of the interaction parameters χH and χ12. The results are discussed in terms of the existing theories for polymer solutions. 相似文献
2.
Pseudowollastonite (psW) coatings on titanium alloys substrates were prepared by laser ablation and immersed in simulated body fluid (SBF) for different periods in order to investigate the nucleation and growth of hydroxyapatite (HA)-like formation on their surface. The structure of the coatings before soaking was analysed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The interfacial reactions product was examined by thin-film XRD, SEM and transmission electron microscopy at low and high resolution level, both fitted with energy-dispersive X-ray spectroscopy. Additional changes in ionic concentration, using inductively couple plasma atomic emission spectroscopy, were determined as well as pH right at the psW-coatings/SBF interface using an ion-sensitive field effect transistor. The solution composition changes, increasing the Ca(2+) and Si(4+) concentration and pH as a function of the soaking time while HPO(4)(2-) decreased.The results obtained showed that the coating surfaces were covered by HA-like, which indicated that the psW-coating possesses good bioactivity and also suggested that the mechanism of HA-like layer formation in SBF was similar to that showed in in vitro test by other silica-based materials. 相似文献
3.
Recurrent episodes of coma: an unusual phenotype of familial hemiplegic migraine with linkage to chromosome 1 总被引:4,自引:0,他引:4
Echenne B Ducros A Rivier F Joutel A Humbertclaude V Roubertie A Azaïs M Bousser MG Tournier-Lasserve E 《Neuropediatrics》1999,30(4):214-217
Over a period of ten years, a boy had several episodes of coma, lasting three to five days. Each episode was preceded by hemiparesis or paresthesias, aphasia, headaches and behavioural changes, with subsequent loss of consciousness. Partial seizures occurred during the first episode. A history of migraine or hemiplegic migraine was found in several members of the family. Linkage to chromosome 1q21-23, where a gene for familial hemiplegic migraine has been mapped, was shown in this family. 相似文献
4.
Effect of vitamin A status at the end of term pregnancy on the saturation of retinol binding protein with retinol 总被引:4,自引:0,他引:4
Sapin V Alexandre MC Chaïb S Bournazeau JA Sauvant P Borel P Jacquetin B Grolier P Lémery D Dastugue B Azaïs-Braesco V 《The American journal of clinical nutrition》2000,71(2):537-543
BACKGROUND: Vitamin A (retinol), which is required for normal fetal development and successful gestation, circulates in the blood bound to a specific protein, the retinol binding protein (RBP). Little is known about the transport and metabolism of this complex protein or about retinol status during normal human pregnancy. OBJECTIVE: The aim of this study was to assess retinol status and transport modalities of retinol in well-nourished women with normal pregnancies, a population poorly investigated compared with pathologic and malnourished pregnant women. DESIGN: The maternal blood and cord blood concentrations of retinol, vitamin E, beta-carotene, RBP, and transthyretin of pregnant French women at term (n = 27) were measured and compared with values from a nonpregnant control group (n = 27). In addition, holo-RBP (retinol bound), apo-RBP (retinol free), and total protein were assessed in both groups to enable the hemodilution occurring during pregnancy to be taken into consideration and to evaluate the extent of saturation of RBP with retinol. RESULTS: Healthy pregnant women at term had normal serum circulatory amounts of retinol, vitamin E, binding proteins, and beta-carotene. However, they had less binding of retinol to RBP (holo-RBP: 49.9% in pregnant women, 54.0% in cord blood, and 77.5% in the control group). CONCLUSION: The results of this study suggest that retinol homeostasis and transport are modified during normal human pregnancy. 相似文献
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8.
Akash Verma Aza Taha Sridhar Venkateswaran Augustine Tee 《Singapore medical journal》2015,56(5):268-273
INTRODUCTION
This study aimed to assess the effectiveness of medical thoracoscopy (MT) and thoracoscopic talc poudrage (TTP) in patients with exudative pleural effusion.METHODS
We evaluated the diagnostic yields, complications and outcomes of MT and TTP in 41 consecutive patients with symptomatic pleural effusions who were planned to undergo both procedures from 1 December 2011 to 30 November 2012. Data was reviewed retrospectively and prospectively up to March 2013.RESULTS
Among the 41 patients, 36 underwent MT with the intent of biopsy and talc pleurodesis, 2 underwent MT for pleurodesis only and 3 had failed MT. Aetiologies of pleural effusion included lung cancer (n = 14), tuberculosis (n = 9), breast cancer (n = 7), ovarian cancer (n = 2), malignant mesothelioma (n = 1), congestive cardiac failure (n = 1), peritoneal dialysis (n = 1) and hepatic hydrothorax (n = 1); pleural effusion was undiagnosed in five patients. The overall diagnostic yield of MT, and the yield in tubercular and malignant pleural effusions were 77.8%, 100.0% and 82.6%, respectively; it was inconclusive in 22.2%. Complications that occurred were self-limiting, with no procedure-related mortality. The 30-day mortality rate was 17.1%. A total of 15 patients underwent TTP. The 30-, 60- and 90-day success rates were 77.8%, 80.0% and 80.0%, respectively, with one patient having complications (i.e. empyema). The 30-day mortality was 40.0%.CONCLUSION
MT is a safe procedure with high diagnostic yields in undiagnosed pleural effusions. TTP is an effective method to stop recurrence of pleural effusions. 相似文献9.
10.
Mansilla Francisco JJ Díez De los Ríos Cuenca F Cabrera Azaña S Cortés Torres J Macías López MJ González Castillo JA Ferreras Duarte JL 《CANNT journal》2012,22(1):25-29
The incidence of end stage renal disease in older persons has been increasing progressively over the last 10 years. Improved survival rates with renal replacement therapy are making this increased prevalence even more pronounced. The usual risks of morbidity and requirements for specialized care associated with older people increase dramatically when they have chronic kidney disease (CKD). It has been seen that the majority of patients in hemodialysis units are over the age of 60, and have significant co-morbidities. The relationship between older age, chronic disorders and functional dependence (FD) is well known. Accordingly, nursing care planning must be designed with this in mind. The aim of this study was to assess whether the comorbidity associated with CKD modifies FD in patients on hemodialysis. We undertook a prospective longitudinal cohort study of hemodialysis outpatients in Málaga, Spain, using the Barthel test to establish FD and the Charlson comorbidity index to quantify comorbidity. All health events were analyzed to select those study patients with incident comorbidity, understood as the appearance of a new disease that could modify the Charlson comorbidity index, and determine the change in FD. Multivariate linear regression showed that the best model for predicting functional loss was that which considered comorbidity adjusted for age, particularly when it occurred as a result of hospital admission, as it was shown to have an important predictive value for the onset of a decrease in functional dependency scores in patients with CKD. 相似文献