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Paul I. Dalven James R. Hildebrandt Abraham Shamir Anthony J. Laccetti Leonard T. Hodgins Harry P. Gregor 《应用聚合物科学杂志》1985,30(3):1113-1132
Various high molecular weight copolymers of acrylonitrile and a vinyl comonomer containing an aryl amine, a pyridine, or an aliphatic hydroxyl group were synthesized via slurry polymerization techniques so as to contain from 1 to 15 mol % functional comonomer. The comonomer content was quantitated by ultraviolet absorbance, base titration of acid polymer salts, and/or relative chemical reactivity with trichloro-s-triazine. Thin films were cast from copolymer solutions, coagulated into unsupported ultrafiltration membrances, and characterized with respect to both water permeability and pore size distribution. Analysis by size exclusion chromatography of the membrane permeate of a pool of dextran fractions yielded a continuous distribution curve for membrane pore size over the range 1.5 to 70 nm. The ultrafiltration membranes were used for protein immobilization after appropriate chemical activation. The three distinct types of functional copolymers gave comparable results for α-chymotrypsin, with protein weight loadings of 6–12% and 40–65% retention of enzymatic specific activity. 相似文献
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Two patients are presented where internal mammary artery grafting was performed for the relief of symptomatic coronary artery disease. At follow-up the internal mammary artery was occluded and a communication between the internal mammary vein and the native coronary artery was demonstrated. These patients were characterised by the early recurrence of angina or the appearance of a continuous murmur. Both patients were treated by re-operation with ligation of the arterio-venous fistula and saphenous vein grafting. 相似文献
5.
Urinary protein and calcium excretion were assessed in 77 patients with the hepatic glycogen storage diseases (GSD): 30 with GSD-I (median age 12.4 years, range 3.2-32.9 years), 25 with GSD-III (median age 10.5 years, range 4.2-31.3 years) and 22 with GSD-IX (median age 11.8 years, range 1.2-35.4 years). Inulin (Cinulin) and para-aminohippuric acid (CPAH) clearances were also measured in 33 of these patients. Those with GSD-I had significantly greater albumin (F = 15.07, P < 0.001), retinol-binding protein (RBP) (F = 14.66, P < 0.001), N-acetyl-beta-D-glucosaminidase (NAG) (F = 9.41, P < 0.001) and calcium (F = 7.41, P = 0.001) excretion than those with GSD-III and GSD-IX. GSD-I patients (n = 18) also had significantly higher Cinulin (F = 5.57, P = 0.009), but CPAH did not differ (F = 0.77, NS). Renal function was normal in GSD-III and GSD-IX patients. In GSD-I, Cinulin (r = -0.51, P = 0.03) and NAG excretion (r = -0.40, P = 0.03) were inversely correlated with age, whereas albumin excretion was positively correlated with age (r = +0.41, P = 0.03). RBP and calcium excretion were generally high throughout all age groups. Hyperfiltration in GSD-I is associated with renal tubular proteinuria that occurs before the onset of significant albuminuria. Deficiency of glucose-6-phosphatase within the proximal renal tubule may primarily cause tubular dysfunction, glomerular hyperfiltration being a secondary phenomenon. 相似文献
6.
Midden and Dahl, in a recent paper, have presented important data on the inactivation of bacteria by singlet oxygen. In analyzing the data, use was made of a theory published earlier by the present author. The purpose of this paper is to point out that theory and experiment can be brought into better agreement by assuming that the interaction of singlet oxygen with the bacteria takes place in an essentially lipid environment rather than aqueous. 相似文献
7.
N Cherradi MF Rossier MB Vallotton AM Capponi 《Canadian Metallurgical Quarterly》1996,271(42):25971-25975
In adrenal glomerulosa cells, angiotensin II (Ang II) stimulates aldosterone synthesis through rises of cytosolic calcium ([Ca2+]c). The rate-limiting step in this process is the transfer of cholesterol to the inner mitochondrial membrane, where it is converted to pregnenolone by the P450 side chain cleavage enzyme. The aim of the present study was to examine the effect of changes in [Ca2+]c and of Ang II on intramitochondrial cholesterol distribution. Freshly prepared bovine zona glomerulosa cells were submitted to a cytosolic Ca2+ clamp (600 nM) or stimulated with Ang II (10 nM). Mitochondria were isolated and subfractionated into outer membranes (OM), inner membranes (IM), and contact sites (CS). Cholesterol content was determined by the cholesterol oxidase assay. Stimulation of intact cells with Ca2+ led to a marked decrease in cholesterol content of OM (to 54 +/- 24% of controls, n = 5) and to a concomitant increase of cholesterol in CS and IM (to 145 +/- 14%, n = 5). When glomerulosa cells were exposed to Ang II, a marked increase of cholesterol in CS occurred (to 172 +/- 16% of controls, n = 5). No significant changes were detected in OM cholesterol, suggesting a stimulation of cholesterol supply to the mitochondria in response to Ang II. Cycloheximide specifically and significantly reduced Ca2+-activated cholesterol transfer to CS and IM. In conclusion, our data indicate that one of the main functions of the Ca2+ messenger is to increase cholesterol supply to the P450 side chain cleavage enzyme by enhancing endogenous intermembrane cholesterol transfer to a mitochondrial site containing the enzymes responsible for the initial steps of the steroidogenic cascade. 相似文献
8.
30 yrs prior to this article, psychologists at the New York University Medical Center addressed issues at the interface of clinical neuropsychology and rehabilitation. The work gave rise to programs for interventions with people with cognitive deficits after brain damage, stroke, and traumatic brain injury. The expansion of this early work is discussed in reference to articles about instrument development, cognitive remediation programs, issues of program outcome, and problems in delivering neuropsychological services to individuals with brain trauma. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
9.
Prior research has reported a relation between physical attractiveness and severity of mental disorder, with less attractive people being more maladjusted. However, because these two variables have been measured simultaneously, it has not been possible to separate cause from effect. To clarify this question, in this study we first measured physical attractiveness, social competence, and perceived risk of developing a mental disorder in 280 college women. Seven months later, we measured the subjects' self-perception of having a mental disorder. Women who were more attractive were higher in social competence and lower in perceived risk of mental disorder. More attractive women were also lower in self-perception of mental disorder 7 months later. This relation between attractiveness and self-perception of mental disorder remained significant even after controlling for the Time 1 measures (social competence, perceived risk of mental disorder, and age). The implications of these findings for the hypothesized role of attractiveness in the determination of adjustment are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
10.
SW Qian JK Burmester PD Sun A Huang DJ Ohlsen L Suardet KC Flanders D Davies AB Roberts MB Sporn 《Canadian Metallurgical Quarterly》1994,33(40):12298-12304
Transforming growth factor-beta (TGF-beta) is a potent regulator of cell growth and differentiation. On the basis of the crystal structure of TGF-beta 2, we have designed and synthesized two mutant TGF-beta s, TGF-beta 1 (71 Trp) and TGF-beta 1 (delta 69-73). Although both of these molecules inhibited the growth of Mv1Lu mink lung epithelial cells and LS1034 colorectal cancer cells, which are affected equally by TGF-beta 1 and TGF-beta 2, TGF-beta 1 (delta 69-73) was much less potent than TGF-beta 1 or TGF-beta 1 (71 Trp) at inhibiting the growth of LS513 colorectal cancer cells which are growth-inhibited by TGF-beta 1 but not TGF-beta 2. Both TGF-beta 1 (71 Trp) and TGF-beta 1 (delta 69-73) increased levels of mRNAs for fibronectin and plasminogen activator inhibitor with Mv1Lu cells, whereas only TGF-beta 1 (71 Trp) and not TGF-beta 1 (delta 69-73) up-regulated the mRNA level of carcinoembryonic antigen in LS513 cells. The expression level of carcinoembryonic antigen mRNA in LS1034 cells was not altered by either wild-type or mutant TGF-beta s. Receptor labeling experiments demonstrated that TGF-beta 1 (71 Trp) bound with high affinity to the cell-surface receptors of Mv1Lu, LS1034, and LS513 cells while TGF-beta 1 (delta 69-73) bound effectively to the receptors of Mv1Lu and LS1034 cells but much less to the receptors on LS513 cells.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献