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21.
This research aimed to observe the behavior of mesenchymal stem cells (MSCs) isolated from periodontal granulation tissue (gt) when manipulated ex vivo to induce three‐dimensional (3D) spheroid (aggregates) formation as well as when seeded on two bone scaffolds of animal origin. Periodontal gt was chosen as a MSC source because of its availability, considering that it is eliminated as a waste material during conventional surgical therapies. 3D aggregates of cells were generated; they were grown for 3 and 7 days, respectively, and then prepared for transmission electron microscopic analysis. The two biomaterials were seeded for 72 h with gtMSCs and prepared for scanning electronic microscopic observation. The ultrastructural analysis of 3D spheroids remarked some differences between the inner and the outer cell layers, with a certain commitment observed at the inner cells. Both scaffolds showed a relatively smooth surface at low magnification. Macro‐ and micropores having a scarce distribution were observed on both bone substitutes. gtMSCs grew with relative difficulty on the biomaterials. After 72 h of proliferation, gtMSCs scarcely covered the surface of bovine bone scaffolds, demonstrating fibroblast‐like or star‐like shapes with elongated filiform extensions. Our results add other data on the possible usefulness of gtMSC and could question the current paradigm regarding the complete removal of chronically inflamed gts from the defects during periodontal surgeries. Until optimal protocols for ex vivo manipulation of MSCs are available for clinical settings, it is advisable to use biocompatible bone substitutes that allow the development of progenitor cells. Microsc. Res. Tech. 78:792–800, 2015. © 2015 Wiley Periodicals, Inc.  相似文献   
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Autistic disorder is a complex genetic disease. Because of previous reports of individuals with autistic disorder with duplications of the Prader-Willi/Angelman syndrome critical region, we screened several markers across the 15q11-13 region, for linkage disequilibrium. One hundred forty families, consisting predominantly of a child with autistic disorder and both parents, were studied. Genotyping was performed by use of multiplex PCR and capillary electrophoresis. Two children were identified who had interstitial chromosome 15 duplications and were excluded from further linkage-disequilibrium analysis. Use of the multiallelic transmission-disequilibrium test (MTDT), for nine loci on 15q11-13, revealed linkage disequilibrium between autistic disorder and a marker in the gamma-aminobutyric acidA receptor subunit gene, GABRB3 155CA-2 (MTDT 28.63, 10 df, P=.0014). No evidence was found for parent-of-origin effects on allelic transmission. The convergence of GABRB3 as a positional and functional candidate along with the linkage-disequilibrium data suggests the need for further investigation of the role of GABRB3 or adjacent genes in autistic disorder.  相似文献   
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Many chemical reactions are catalysed by metal complexes, and insight into their mechanisms is essential for the design of future catalysts. A variety of conventional spectroscopic techniques are available for the study of reaction mechanisms at the ensemble level, and, only recently, fluorescence microscopy techniques have been applied to monitor single chemical reactions carried out on crystal faces and by enzymes. With scanning tunnelling microscopy (STM) it has become possible to obtain, during chemical reactions, spatial information at the atomic level. The majority of these STM studies have been carried out under ultrahigh vacuum, far removed from conditions encountered in laboratory processes. Here we report the single-molecule imaging of oxidation catalysis by monitoring, with STM, individual manganese porphyrin catalysts, in real time, at a liquid-solid interface. It is found that the oxygen atoms from an O2 molecule are bound to adjacent porphyrin catalysts on the surface before their incorporation into an alkene substrate.  相似文献   
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OBJECTIVES: Contribution of cellular immunity to the onset and perpetuation of alcohol-induced liver damage remains controversial. The aim of this work was to know whether T-cells participate in the pathogenesis of alcoholic liver injury by measuring the serum levels of sIL-2R in alcoholic patients with different degree of hepatic damage. PATIENTS AND METHODS: Fifty two patients and eighteen healthy subjects (Control group) were included. All patients were active drinkers of at least 100 grams/day of ethanol over a ten-years period. Serum sIL-2R was determined by ELISA. Liver biopsy was performed in all patients and liver function tests, serum immunoglobulins and complement proteins C3 and C4 were measured in all participants. The relationship between the sIL-2R and the severity of liver disease was studied. RESULTS: Circulating sIL-2R was higher in the group of patients than in the control (2.388 +/- 275.7 U/ml vs. 795.7 +/- 48.7 IU/mL; p < 0.001). There were not increased circulating sIL2R in those patients with alcoholic hepatitis. However, patients with cirrhosis showed increased serum sIL-2R regardless of the presence of alcoholic hepatitis. Furthermore, serum levels of sIL-2R inversely correlated with hepatic function test (r = -0.69; p < 0.001 for serum albumin; and r = -0.73; p < 0.001 for the prothrombin time) and were highest in those patients of the Child-Turcotte's class C. CONCLUSIONS: Circulating sIL-2R increases in alcoholic cirrhosis. However, our data do not support a contributory role of the cellular immunity, as assessed by circulating sIL-2R levels to the alcoholic liver damage. The increased serum sIL-2R in cirrhosis may result from defective heptic clearance of this molecule.  相似文献   
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To better understand the phenomenon of P-glycoprotein (P-170) expression we investigated lymphocyte subpopulations for P-170 function in healthy volunteers. Studies were based on three-colour flow cytometry including the fluorescent probe rhodamine 123 (Rh123), which is transported by P-170. Marked Rh123 efflux was detected in CD8+ T lymphocytes with CD8+/CD45RA+ T cells (naive cells) showing significantly higher P-170 activity as compared with CD8+/CD45RA- cells (P<0.04). Vice versa, CD8+/CD45RO+ T cells (memory cells) demonstrated less P-170 activity than CD8+/CD45RO- cells (P<0.04). P-170 function was less prominent in CD4+ T cells, however, Rh123 efflux was higher in the CD4+/CD45RA+ and CD4+/CD45RO- subpopulations (P<0.025) corresponding to the CD8+ results. Dye efflux differed significantly between activated and non-activated CD8+ and CD4+ as well as CD8+/CD11b+ and CD8+/CD11b- T lymphocytes. Since CD16+ natural killer cells (NK) expressed the highest level of P-170, the NK cytotoxicity against 51Cr-labelled K562 target cells was assayed in the presence or absence of P-170 inhibitors. NK related cytotoxicity was significantly reduced in the presence of R-verapamil and dexnigaldipine-HCP in a dose-dependent manner. The differential expression of P-170 activity in naive and memory T cells together with the reduced NK related cytotoxicity in the presence of MDR-modulators suggest a physiological role of P-170 in immunological functions of these lymphocyte subsets. Consequently, the addition of MDR modulators to conventional chemotherapy as a strategy to overcome drug resistance should consider possible adverse immunosuppressive effects.  相似文献   
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Haemodynamic measurements were carried out after administration of furosemide to 10 patients suffering from acute myocardial infarction and congestive heart failure. It was observed that a transient deterioration in cardiac function (decreased cardiac output, increased enddiastolic pulmonary arterial pressure and increased pulmonary and systemic resistance) occured in the pre-diuretic stage in these failing hearts. After the onset of diuresis the haemodynamic parameters showed a reversal of the previous trends (increased cardiac output, decreased enddiastolic pulmonary arterial pressure and pulmonary resistance). The consistently lower enddiastolic pulmonary arterial pressure in the diuretic phase as compared with the pre-diuretic value ensured an improvement in cardiac haemodynamics. An attempt was made to interpret the haemodynamic results in the light of the Frank-Starling's curve.  相似文献   
29.
张晓东 《乙烯工业》2002,14(3):24-27
裂解过程中产生的表面活性组分和加入的化学添加剂能导致油水界面张力降低,使得从工艺水中分离裂解汽油变得更难。工艺水中裂解汽油含量过高会导致工艺水汽提和稀释蒸汽发生系统结垢加剧,裂解汽油损失,污水处理费用上升,停车时间延长和运行成本增高,文中详细介绍了高效液/液聚结器在Naphtachimie装置4a多的使用情况,该技术分离效果显著,每年可节约操作费用约30万美元。  相似文献   
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A new fast-Fourier-transform-based model of a page-oriented holographic data-storage system is presented. The model accounts for essential system and storage material features (e.g. diffraction, noises, and saturation) and provides reliable results in the form of output images, histograms, or bit-error rates. The model is built on a modular basis and provides the possibility of working with different system versions, key components, and storage materials. Applications of the method are presented through examples of optimization of the data density, reference beam size at Gaussian beam illumination, and calculation of the storage medium's positioning tolerances in accordance with the results of test measurements.  相似文献   
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