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91.
Biogas production has been shown to be inhibited by branched chain fatty acids (isobutyric, isovaleric) produced in the digester by cellulolytic organisms. Performance of these mixed cellulolytic cultures isolated at 25°C (C25) and at 35° (C35) in a batch digester using cattle manure confirmed that C35, which forms mainly straight chain fatty acids from cellulose was more suitable for use as an inoculum than C25 which formed predominantly branched chain fatty acids. Reconstitution of cellulolytic culture C35 and mixed methanogens M35 almost doubled both the amount and rate of methane production. Cellulolytic culture was useful in pretreatment of water hyacinth prior to its use as a substrate for methane generation A method for preservation and transportation of mixed cellulolytic culture for use as an inoculum in the digester is described.  相似文献   
92.
The ability to accurately and noninvasively quantify fatty infiltration in organs such as the liver and the pancreas remains a critical component in understanding the link between obesity and its comorbidities such as type 2 diabetes and fatty liver disease. Single‐voxel (1H) proton magnetic resonance spectroscopy (MRS) has long been regarded as the gold‐standard noninvasive technique for such measurements. Recent advances in three‐dimensional fat–water magnetic resonance imaging (MRI) methods have led to the development of rapid, robust, and quantitative approaches that can accurately characterize the proportion of fat and water content in underlying tissues across the full imaging volume, and hence entire organs of interest. One such technique is called IDEAL (Iterative Decomposition with Echo Asymmetry and Least squares estimation). This article prospectively compares three‐dimensional (3D) IDEAL‐MRI and single‐voxel MRS in the assessment of hepatic (HFF) and pancreatic fat fraction (PFF) in 16 healthy subjects. MRS acquisitions took 3–4 min to complete whereas IDEAL acquisitions were completed in 20‐s breath‐holds. In the liver, there was a strong correlation (slope = 0.90, r2 = 0.95, P < 0.001) between IDEAL and MRS‐based fat fractions. In the pancreas, a poorer agreement between IDEAL and MRS was observed (slope = 0.32, r2 = 0.51, P < 0.02). The discrepancy of PFF is likely explained by MRS signal contamination from surrounding visceral fat, presumably during respiratory motion. We conclude that IDEAL is equally accurate in characterizing hepatic fat content as MRS, and is potentially better suited for fat quantification in smaller organs such as the pancreas.  相似文献   
93.
94.
Mungbean yellow mosaic India virus (MYMIV)—the causal agent of the yellow mosaic disease is responsible for severe damage of crops that are of great economic importance. In the current study, we explored the process of MYMIV infection and its natural resistance by analysing the expression of early and late viral genes at different time points in the leaves of resistant and susceptible Vigna mungo plants. Accordingly, we have periodically evaluated several biochemical parameters commonly associated with oxidative status of resistant and susceptible V. mungo plants during MYMIV infection. Our study revealed that accumulation levels of the early as well as late expressed genes of MYMIV were low and high in the resistant and susceptible plants, respectively; whereas membrane stability index (MSI) exhibited an opposite response. Moreover, a decrease in the malondialdehyde levels along with an increase in the activities/levels of different antioxidant enzymes, total phenol and H2O2 was noted during the early stages of infection in the resistant plants. Such observations argue in favour of strong defensive capability of the resistant plants in restricting the accumulation of viral RNA and generation of harmful free radicals within the studied tissue. Collectively, it appears that obstruction of viral invasion in plant cell wall, restriction in viral DNA replication, and early onset of antioxidant defense responses altogether might be responsible for MYMIV natural resistance. Such information is helpful in understanding the pathogenesis of MYMIV infection and its resistance in V. mungo and other economically important crops.  相似文献   
95.
The present study reports an unequivocal and improved protocol for efficient screening of salt tolerance at flowering stage in rice, which can aid phenotyping of population for subsequent identification of QTLs associated with salinity stress, particularly at reproductive stage. To validate the new method, the selection criteria, level and time of imposition of stress; plant growth medium were standardized using three rice genotypes. The setup was established with a piezometer placed in a perforated pot for continuous monitoring of soil EC and pH throughout the period of study. Further, fertilizer enriched soil was partially substituted by gravels for stabilization and maintaining the uniformity of soil EC in pots without hindering its buffering capacity. The protocol including modified medium (Soil:Stone, 4:1) at 8 dS m?1 salinity level was validated using seven different genotypes possessing differential salt sensitivity. Based on the important selection traits such as high stability index for plant yield, harvest index and number of grains/panicle and also high K+ concentration and low Na+– K+ ratio in flag leaf at grain filling stage were validated and employed in the evaluation of a mapping population in the modified screening medium. The method was found significantly efficient for easy maintenance of desired level of soil salinity and identification of genotypes tolerant to salinity at reproductive stage.  相似文献   
96.
An effort was made in the present study to identify the main effect and epistatic quantitative trait locus (QTL) for the morphological and yield-related traits in peanut. A recombinant inbred line (RIL) population derived from TAG 24 × GPBD 4 was phenotyped in seven environments at two locations. QTL analysis with available genetic map identified 62 main-effect QTLs (M-QTLs) for ten morphological and yield-related traits with the phenotypic variance explained (PVE) of 3.84–15.06%. Six major QTLs (PVE >?10%) were detected for PLHT, PPP, YPP, and SLNG. Stable M-QTLs appearing in at least two environments were detected for PLHT, LLN, YPP, YKGH, and HSW. Five M-QTLs governed two traits each, and 16 genomic regions showed co-localization of two to four M-QTLs. Intriguingly, a major QTL reported to be linked to rust resistance showed pleiotropic effect for yield-attributing traits like YPP (15.06%, PVE) and SLNG (13.40%, PVE). Of the 24 epistatic interactions identified across the traits, five interactions involved six M-QTLs. Three interactions were additive × additive and remaining two involved QTL × environment (QE) interactions. Only one major M-QTL governing PLHT showed epistatic interaction. Overall, this study identified the major M-QTLs for the important productivity traits and also described the lack of epistatic interactions for majority of them so that they can be conveniently employed in peanut breeding.  相似文献   
97.
The human brain and its temporal behavior correlated with development, structure, and function is a complex natural system even for its own kind. Coding and automation are necessary for modeling, analyzing and understanding the 86.1 ± 8.1 billion neurons, an almost equal number of non-neuronal glial cells, and the neuronal networks of the human brain comprising about 100 trillion connections. ‘Computational neuroscience’ which is heavily dependent on biology, physics, mathematics and computation addresses such problems while the archival, retrieval and merging of the huge amount of generated data in the form of clinical records, scientific literature, and specialized databases are carried out by ‘neuroinformatics’ approaches. Neuroinformatics is thus an interface between computer science and experimental neuroscience. This article provides an introduction to computational neuroscience and neuroinformatics fields along with their state-of-the-art tools, software, and resources. Furthermore, it describes a few innovative applications of these fields in predicting and detecting brain network organization, complex brain disorder diagnosis, large-scale 3D simulation of the brain, brain–computer, and brain-to-brain interfaces. It provides an integrated overview of the fields in a non-technical way, appropriate for broad general readership. Moreover, the article is an updated unified resource of the existing knowledge and sources for researchers stepping into these fields.  相似文献   
98.
Li and Mn‐rich layered oxides, xLi2MnO3·(1–x)LiMO2 (M=Ni, Mn, Co), are promising cathode materials for Li‐ion batteries because of their high specific capacity that can exceed 250 mA h g?1. However, these materials suffer from high 1st cycle irreversible capacity, gradual capacity fading, low rate capability, a substantial charge‐discharge voltage hysteresis, and a large average discharge voltage decay during cycling. The latter detrimental phenomenon is ascribed to irreversible structural transformations upon cycling of these cathodes related to potentials ≥4.5 V required for their charging. Transition metal inactivation along with impedance increase and partial layered‐to‐spinel transformation during cycling are possible reasons for the detrimental voltage fade. Doping of Li, Mn‐rich materials by Na, Mg, Al, Fe, Co, Ru, etc. is useful for stabilizing capacity and mitigating the discharge‐voltage decay of xLi2MnO3·(1–x)LiMO2 electrodes. Surface modifications by thin coatings of Al2O3, V2O5, AlF3, AlPO4, etc. or by gas treatment (for instance, by NH3) can also enhance voltage and capacity stability during cycling. This paper describes the recent literature results and ongoing efforts from our groups to improve the performance of Li, Mn‐rich materials. Focus is also on preparation of cobalt‐free cathodes, which are integrated layered‐spinel materials with high reversible capacity and stable performance.  相似文献   
99.
Idiotypic determinants of immunoglobulin molecules can evoke both CD4(+) and CD8(+) T responses and exist not only as the integral components of a bona fide antigen binding receptor but also as distinct molecular entities in the processed forms on the cell surface of B lymphocytes. The present work provides experimental evidence for the concept that regulation of memory B cell populations can be achieved through the presentation of idiotypic and anti-idiotypic determinants to helper and cytotoxic cell. The potential of B cells to present antigens to helper and cytotoxic T cells through class II and class I MHC suggests a mechanism by which both B and T cell homeostasis can be maintained. We provide evidence for the generation of idiotype- and antigen-specific Th and Tc cells upon immunization of syngenic mice with antigen or idiotypic antibody (Ab1) or anti-idiotypic antibody (Ab2). The selective activation and proliferation of the antigen-specific Th and Tc cells mediated by idiotypic stimulation observed in these experiments suggests a B-cell-driven mechanism for the maintenance of antigen-specific T cell memory in the absence of antigenic stimulation, under certain conditions.  相似文献   
100.
We studied the roles of endothelins in determining ventilation (Va) and perfusion (Q) mismatch in a porcine model of acute pulmonary thromboembolism (APTE), using a nonspecific endothelin antagonist, tezosentan. Nine anesthetized piglets (approximately 23 kg) received autologous clots (approximately 20 g) via a central venous catheter at time = 0 min. The distribution of Va and Q at five different time points (-30, -5, 30, 60, 120 min) was mapped by fluorescent microspheres of 10 different colors. Five piglets (group 1) received tezosentan (courtesy of Actelion) starting at time = 40 min for 2 h, and four piglets (group 2) received only saline and served as control. Our results showed that, in all of the animals at 30 min following APTE but before tezosentan, the mean Va/Q was increased, as was Va/Q heterogeneity (log SD Va/Q), which represented a widening of its main peak. Afterwards, tezosentan attenuated the pulmonary hypertension in group 1 but also produced moderate systemic hypotension. However, it did not improve arterial PO2 or Va/Q mismatch. We concluded that endothelin antagonism had minimal impact on gas exchange following APTE and confirmed our earlier observation that the main mechanism for hypoxemia in APTE was due to the mechanical redistribution of pulmonary regional blood flow away from the embolized vessels, resulting in the creation of many divergent low and high Va/Q regions.  相似文献   
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