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991.
During ruminal biohydrogenation of α‐linolenic acid, a non‐conjugated non‐methylene interrupted dienoic acid is formed containing a t10 double bond, namely t10,c15–18:2. The present study was designed to examine whether t10,c15–18:2 would exert similar anti‐adipogenic effects compared to t10,c12–18:2 in 3T3‐L1 adipocytes. Differentiated 3T3‐L1 adipocytes were treated with 35 or 70 µM of LNA, t10,c12–18:2, t10,c15–18:2, or bovine serum albumin (BSA) vehicle control for 120 h. Cellular triacylglycerol and protein were quantified using commercial colorimetric kits. Cells were analyzed for fatty acid composition and gene expression using gas chromatography and quantitative PCR, respectively. Trans10,cis12–18:2 decreased (P < 0.05) the adipocyte triacylglycerol (TAG) content, which was mainly related to a reduction in saturated fatty acids (SFA; e.g., 16:0 and 15:0) and cis monounsaturated fatty acids (c‐MUFA; e.g., c9–16:1 and c9–18:1). Trans10,cis12 also decreased (P < 0.05) the expression of genes related to fatty acid synthesis (ACACA, FASN), delta‐9 desaturation (SCD1), fatty acid elongation (ELOVL5), and fatty acid uptake (LPL) and upregulated (P < 0.05) the expression of the rate‐liming enzyme involved in fatty acid β‐oxidation (CPT1). In contrast, LNA and t10,c15–18:2 did not affect the gene expression and cellular content of the TAG, SFA, c‐MUFA, or SCD1 indices in adipocytes. Our findings suggest that t10,c15–18:2, despite having structural similarity to t10,c12–18:2 (presence of a trans‐10 double bond), does not exert anti‐adipogenic effects in 3T3‐L1 adipocytes.  相似文献   
992.
Lipogenesis is the process by which fatty acids are synthesized. In metabolic syndrome, an insulin resistant state along with high plasma levels of free fatty acids (FFA) and hyperglycemia may contribute to the lipogenic process. The aim of the present study was to investigate the effects of oral administration of metformin on the expression of lipogenic genes and glycemic profile in mice fed with low‐carbohydrate high‐fat diet by evaluating their metabolic profile. SWISS male mice were divided into 4 groups (N = 7) that were fed with standard (ST), standard plus metformin (ST + MET), low‐carbohydrate high‐fat diet (LCHFD) and low‐carbohydrate high‐fat diet plus metformin (LCHFD + MET) (100 mg kg?1 diet) diets respectively. Food intake, body weight and blood parameters, such as glucose tolerance, insulin sensitivity, glucose, HDL‐c, total cholesterol, triglycerides, ASL and ALT levels were assessed. Histological analyses were performed on hematoxylin and eosin‐stained epididymal adipose tissue histological specimens. The expression levels of peroxisome proliferator‐activated receptor (PPARγ), sterol regulatory element‐binding protein 1 (SREBP1), fatty acid synthase (FAS) and acetyl‐CoA carboxylase (ACC), were assessed by RT‐PCR. This study showed that metformin decreased adipocyte area, body weight and food consumption in obese animals when compared to the standard group. Furthermore, the expression of lipogenic markers in adipose tissue were diminished in obese animals treated with metformin. This data showed that oral administration of metformin improved glucose and lipid metabolic parameters in white adipose tissue by reducing the expression of lipogenesis markers, suggesting an important clinical application of MET in treating obesity‐related diseases in metabolic syndrome.  相似文献   
993.
To facilitate the analysis of castor (Ricinus communis L.) seed fractions and germplasm for ricin content, we investigated the use of enzyme‐linked immunosorbent assay (ELISA) methods to differentiate between ricin toxin and the related Ricinus communis agglutinin (RCA). Both proteins are based on a heterodimeric AB structure, with a common A chain. RCA comprises two dimers of A and B chains. Both proteins are found in the meal remaining after castor oil extraction and impede the commercial production of castor seed in the USA. We identified pairs of monoclonal antibodies (mAbs) that could distinguish between the structurally related proteins that share a common A chain. Antibody specificity was determined by ELISA and checked by immunoblotting. We found that mAb–mAb pairs afforded quantification of each castor protein, and that a mAb paired with a commercial polyclonal antibody provided detection of both with comparable sensitivity.  相似文献   
994.
Microfluidics affords precise control over the flow of multiphasic fluids in micron-scale channels. By manipulating the viscous and surface tension forces present in multiphasic flows in microfluidic channels, it is possible to produce highly uniform emulsion droplets one at a time. Monodisperse droplets generated based on microfluidics are useful templates for producing uniform microcapsules and microparticles for encapsulation and delivery of active ingredients as well as living cells. Also, droplet microfluidics have been extensively exploited as a means to enable highthroughput biological screening and assays. Despite the promise droplet-based microfluidics hold for a wide range of applications, low production rate (<<10mL/hour) of emulsion droplets has been a major hindrance to widespread utilization at the industrial and commercial scale. Several reports have recently shown that one way to overcome this challenge and enable mass production of microfluidic droplets is to parallelize droplet generation, by incorporating a large number of droplet generation units (N>>100) and networks of fluid channels that distribute fluid to each of these generators onto a single chip. To parallelize droplet generation and, at the same time, maintain high uniformity of emulsion droplets, several considerations have to be made including the design of channel geometries to ensure even distribution of fluids to each droplet generator, methods for large-scale and uniform fabrication of microchannels, device materials for mechanically robust operation to withstand high-pressure injection, and development of commercially feasible fabrication techniques for three-dimensional microfluidic devices. We highlight some of the recent advances in the mass production of highly uniform microfluidics droplets via parallelization and discuss outstanding issues.  相似文献   
995.
Coal, the most primitive fossil fuel, has been exploited for ages, and reserves dictate the economies of many countries. Presently, most energy is generated by direct combustion, raising concerns over global warming. Biological pretreatment of fossil resources and generation of alternative green energy can address the environmental issues associated with global coal utilization. Biological coal treatment can produce industrially important chemicals and bio-methane by employing microorganisms able to depolymerize/degrade coal. This review discusses current advances in microbial coal conversion, such as the efforts made to comprehend microbial processes, significant outputs of coal conversion, principle components responsible for coal conversion, and factors affecting the biological processes to convert coal. Development of these biological processes can be a stepping stone for greener coal; however, integration of multidisciplinary technologies is needed to increase the efficiency of economic coal utilization and production of economically and industrially feasible biomethane.  相似文献   
996.
Printed functional materials are a rapidly growing area of interest for low-cost high-speed device manufacture with flexographic printing seen as a route to achieving this. The relationship between surface tension of the ink and surface free energy (SFE) of the photopolymer plate is a key for optimum performance. However, traditional methods of surface tension modification of the ink/coating often cannot be employed for functional inks. In this research, rapid, permanent modification of flexographic printing plate’s SFE is achieved through controlled UV-ozone treatment, and the effects of the treatment on the polar and dispersive component of SFE are analyzed by Fourier transform infrared attenuated total reflectance spectroscopy, swelling experiments, and roughness measurements. Printing trials using the modified printing plates reveal improved print uniformity and control of deposited ink layer thickness, as well as improved print features—particularly track and pad junctions which can be problematic for printed electronic applications. The ability to rapidly tailor printing plate SFE is of benefit to all volume printing applications. Furthermore, it is of critical importance for functional printing and printed electronics where surface tension of the ink is determined by the functional material and chemical modification is not possible or desirable.  相似文献   
997.
This study investigated the influence of YbO1.5 concentration on the reactivity between YbO1.5–HfO2 thermal barrier coating (TBC) materials and silicate melts [calcium–magnesium aluminosilicate (CMAS), specifically 33CaO–9MgO–13AlO1.5–45SiO2, all in mol%]. Three thermal barrier oxides (TBO) with YbO1.5 concentration between 30 and 80 mol% were tested at 1300°C and 1500°C. Porous pellets were used to study reaction layer growth and the behavior within infiltrated porosity. Complementary experiments examined the phase equilibria in melts containing varying quantities of the candidate TBOs. The effectiveness of reactive crystallization to limit interaction depth increased with the YbO1.5 concentration in the TBO. The results indicate that the TBO must contain sufficient YbO1.5 to satisfy the equilibrium between the melt and HfO2‐based fluorite phase before YbO1.5‐bearing silicates can precipitate. Increasing the YbO1.5 availability leads to the crystallization of apatite, garnet, silicocarnotite, and/or cuspidine (alumino)silicates. Apatite was observed at 1300°C and 1500°C, garnet and silicocarnotite only appeared at 1300°C, and cuspidine was only evident at 1500°C. The implications for the design of CMAS‐resistant coatings are discussed in the context of the experimental results.  相似文献   
998.
Ferroelectric materials are well‐suited for a variety of applications because they can offer a combination of high performance and scaled integration. Examples of note include piezoelectrics to transform between electrical and mechanical energies, capacitors used to store charge, electro‐optic devices, and nonvolatile memory storage. Accordingly, they are widely used as sensors, actuators, energy storage, and memory components, ultrasonic devices, and in consumer electronics products. Because these functional properties arise from a noncentrosymmetric crystal structure with spontaneous strain and a permanent electric dipole, the properties depend upon physical and electrical boundary conditions, and consequently, physical dimension. The change in properties with decreasing physical dimension is commonly referred to as a size effect. In thin films, size effects are widely observed, whereas in bulk ceramics, changes in properties from the values of large‐grained specimens is most notable in samples with grain sizes below several micrometers. It is important to note that ferroelectricity typically persists to length scales of about 10 nm, but below this point is often absent. Despite the stability of ferroelectricity for dimensions greater than ~10 nm, the dielectric and piezoelectric coefficients of scaled ferroelectrics are suppressed relative to their bulk counterparts, in some cases by changes up to 80%. The loss of extrinsic contributions (domain and phase boundary motion) to the electromechanical response accounts for much of this suppression. In this article, the current understanding of the underlying mechanisms for this behavior in perovskite ferroelectrics is reviewed. We focus on the intrinsic limits of ferroelectric response, the roles of electrical and mechanical boundary conditions, grain size and thickness effects, and extraneous effects related to processing. In many cases, multiple mechanisms combine to produce the observed scaling effects.  相似文献   
999.
As part of a continued push for high permittivity dielectrics suitable for use at elevated operating temperatures and/or large electric fields, modifications of BaTiO3 with Bi(M)O3, where M represents a net‐trivalent B‐site occupied by one or more species, have received a great deal of recent attention. Materials in this composition family exhibit weakly coupled relaxor behavior that is not only remarkably stable at high temperatures and under large electric fields, but is also quite similar across various identities of M. Moderate levels of Bi content (as much as 50 mol%) appear to be crucial to the stability of the dielectric response. In addition, the presence of significant Bi reduces the processing temperatures required for densification and increases the required oxygen content in processing atmospheres relative to traditional X7R‐type BaTiO3‐based dielectrics. Although detailed understanding of the structure–processing–property relationships in this class of materials is still in its infancy, this article reviews the current state of understanding of the mechanisms underlying the high and stable values of both relative permittivity and resistivity that are characteristic of BaTiO3‐Bi(M)O3 dielectrics as well as the processing challenges and opportunities associated with these materials.  相似文献   
1000.
Different cell types possess different miRNA expression profiles, and cell/tissue/organ-specific miRNAs (or profiles) indicate different diseases. Circulating miRNA is either actively secreted by living cells or passively released during cell death. Circulating cell/tissue/organ-specific miRNA may serve as a non-invasive biomarker for allo- or xeno-transplantation to monitor organ survival and immune rejection. In this review, we summarize the proof of concept that circulating organ-specific miRNAs serve as non-invasive biomarkers for a wide spectrum of clinical organ-specific manifestations such as liver-related disease, heart-related disease, kidney-related disease, and lung-related disease. Furthermore, we summarize how circulating organ-specific miRNAs may have advantages over conventional methods for monitoring immune rejection in organ transplantation. Finally, we discuss the implications and challenges of applying miRNA to monitor organ survival and immune rejection in allo- or xeno-transplantation.  相似文献   
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