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431.
432.
The B-cell-specific Src-family kinase Blk is dispensable for B-cell development and activation 下载免费PDF全文
Texido G Su IH Mecklenbräuker I Saijo K Malek SN Desiderio S Rajewsky K Tarakhovsky A 《Molecular and cellular biology》2000,20(4):1227-1233
The B-cell lymphocyte kinase (Blk) is a src-family protein tyrosine kinase specifically expressed in B-lineage cells of mice. The early onset of Blk expression during B-cell development in the bone marrow and the high expression levels of Blk in mature B cells suggest a possible important role of Blk in B-cell physiology. To study the in vivo function of Blk, mice homozygous for the targeted disruption of the blk gene were generated. In homozygous mutant mice, neither blk mRNA nor Blk protein is expressed. Despite the absence of Blk, the development, in vitro activation, and humoral immune responses of B cells to T-cell-dependent and -independent antigens are unaltered. These data are consistent with functional redundancy of Blk in B-cell development and immune responses. 相似文献
433.
434.
Winder CL Al-Adham IS Abdel Malek SM Buultjens TE Horrocks AJ Collier PJ 《Journal of applied microbiology》2000,89(2):289-295
Benzisothiazolone (BIT), N-methylisothiazolone (MIT) and 5-chloro-N-methylisothiazolone (CMIT) are highly effective biocidal agents and are used as preservatives in a variety of cosmetic preparations. The isothiazolones have proven efficacy against many fungal and bacterial species including Pseudomonas aeruginosa. However, some species are beginning to exhibit resistance towards this group of compounds after extended exposure. This experiment induced resistance in cultures of Ps. aeruginosa exposed to incrementally increasing sub-minimum inhibitory concentrations (MICs) of the isothiazolones in their pure chemical forms. The induced resistance was observed as a gradual increase in MIC with each new passage. The MICs for all three test isothiazolones and a thiol-interactive control compound (thiomersal) increased by approximately twofold during the course of the experiment. The onset of resistance was also observed by reference to the altered presence of an outer membrane protein, designated the T-OMP, in SDS-PAGE preparations. T-OMP was observed to disappear from the biocide-exposed preparations and reappear when the resistance-induced cultures were passaged in the absence of biocide. This reappearance of T-OMP was not accompanied by a complete reversal of induced resistance, but by a small decrease in MIC. The induction of resistance towards one biocide resulted in the development of cross-resistance towards other members of the group and the control, thiomersal. It has been suggested that the disappearance of T-OMP from these preparations is associated with the onset of resistance to the isothiazolones in their Kathon form (CMIT and MIT). 相似文献
435.
We propose a method for predicting splice graphs that enhances curated gene models using evidence from RNA-Seq and EST alignments.
Results obtained using RNA-Seq experiments in Arabidopsis thaliana show that predictions made by our SpliceGrapher method are more consistent with current gene models than predictions made
by TAU and Cufflinks. Furthermore, analysis of plant and human data indicates that the machine learning approach used by SpliceGrapher
is useful for discriminating between real and spurious splice sites, and can improve the reliability of detection of alternative
splicing. SpliceGrapher is available for download at . 相似文献
436.
Mohammad Amin Kazemian Sayyed Mostafa Habibi-Khorassani Ali Ebrahimi Malek Taher Maghsoodlou Peyman Mohammadzadeh Jahani Mahbobeh Ghahramaninezhad 《Journal of molecular modeling》2012,18(12):5075-5088
Stable crystalline phosphorus ylides were obtained in excellent yields from the 1:1:1 addition reaction between triphenylphosphine (TPP) and dialkyl acetylenedicarboxylates, in the presence of NH-acids, such as benzhydrazide. To determine the kinetic parameters of the reactions, they were monitored by UV spectrophotometery. The second order fits were automatically drawn and the values of the second order rate constant (k2) were calculated using standard equations within the program. At the temperature range studied the dependence of the second order rate constant (Ln k2) on reciprocal temperature was compatible with Arrhenius equation. This provided the relevant plots to calculate the activation energy of all reactions. Furthermore, useful information were obtained from studies of the effect of solvent, structure of reactants (different alkyl groups within the dialkyl acetylenedicarboxylates) and also concentration of reactants on the rate of reactions. On the basis of experimental data the proposed mechanism was confirmed according to the obtained results and a steady state approximation and the first step (k2) and third (k3) steps of the reactions were recognized as the rate determining steps, respectively. In addition, three speculative proposed mechanisms were theoretically investigated using quantum mechanical calculation. The results, arising from the second and third speculative mechanisms, were far from the experimental data. Nevertheless, there was a good agreement between the theoretical kinetic data, emerge from the first speculative mechanism, and experimental kinetic data of proposed mechanism. Figure
Kinetics and mechanistic study in a synthesis reaction between triphenylphosphine (1) and dialkyl acetylenedicarboxylates (2) in the presence of benzhydrazide (3) Theoretical and Experimental investigation 相似文献
437.
Lath NR Galambos C Rocha AB Malek M Gittes GK Potoka DA 《American journal of physiology. Lung cellular and molecular physiology》2012,302(4):L390-L398
Congenital diaphragmatic hernia (CDH) is associated with significant mortality due to lung hypoplasia and pulmonary hypertension. The role of embryonic pulmonary innervation in normal lung development and lung maldevelopment in CDH has not been defined. We hypothesize that developmental defects of intrapulmonary innervation, in particular autonomic innervation, occur in CDH. This abnormal embryonic pulmonary innervation may contribute to lung developmental defects and postnatal physiological derangement in CDH. To define patterns of pulmonary innervation in CDH, human CDH and control lung autopsy specimens were stained with the pan-neural marker S-100. To further characterize patterns of overall and autonomic pulmonary innervation during lung development in CDH, the murine nitrofen model of CDH was utilized. Immunostaining for protein gene product 9.5 (a pan-neuronal marker), tyrosine hydroxylase (a sympathetic marker), vesicular acetylcholine transporter (a parasympathetic marker), or VIP (a parasympathetic marker) was performed on lung whole mounts and analyzed via confocal microscopy and three-dimensional reconstruction. Peribronchial and perivascular neuronal staining pattern is less complex in human CDH than control lung. In mice, protein gene product 9.5 staining reveals less complex neuronal branching and decreased neural tissue in nitrofen-treated lungs from embryonic day 12.5 to 16.5 compared with controls. Furthermore, nitrofen-treated embryonic lungs exhibited altered autonomic innervation, with a relative increase in sympathetic nerve staining and a decrease in parasympathetic nerve staining compared with controls. These results suggest a primary defect in pulmonary neural developmental in CDH, resulting in less complex neural innervation and autonomic imbalance. Defective embryonic pulmonary innervation may contribute to lung developmental defects and postnatal physiological derangement in CDH. 相似文献
438.
The purpose of this study was to determine whether (-)-epicatechin (mainly found in cocoa) could attenuate detraining effects in the hindlimb muscles of mice. Thirty-two male mice were randomized into 4 groups: control, trained, trained with 14 d of detraining and vehicle (DT-14-W), and trained with 14 d of detraining and (-)-epicatechin [DT-14-(-)-Epi]. DT-14-(-)-Epi received (-)-epicatechin (1.0 mg/kg 2 ×/d), whereas water was given to the DT-14-W group. The latter 3 groups performed 5 wk of endurance training 5 ×/wk. Hindlimb muscles were harvested, and Western blots, as well as enzyme analyses, were performed. Training significantly increased capillary-to-fiber ratio (≈ 78.8%), cytochrome-c oxidase (≈ 35%), and activity (≈ 144%) compared to controls. These adaptations returned to control levels for the DT-14-W group, whereas the DT-14-(-)-Epi group was able to maintain capillary-to-fiber ratio (≈ 44%), CcO protein expression (≈ 45%), and activity (≈ 108%) above control levels. In addition, the increase in capillarity was related to decreased protein expression of thrombospondin-1, an antiangiogenic regulator. Furthermore, there were no significant differences in endurance capacity between the trained and DT-14-(-)-Epi groups. Our data suggest that (-)-epicatechin may be a suitable compound to maintain exercise-induced improved capillarity and mitochondrial capacity, even when exercise regimens are discontinued. 相似文献
439.
Myroslava Lesiv Juan Carlos Laso Bayas Linda See Martina Duerauer Domian Dahlia Neal Durando Rubul Hazarika Parag Kumar Sahariah Mar'yana Vakolyuk Volodymyr Blyshchyk Andrii Bilous Ana Perez‐Hoyos Sarah Gengler Reinhard Prestele Svitlana Bilous Ibrar ul Hassan Akhtar Kuleswar Singha Sochin Boro Choudhury Tilok Chetri
iga Malek Khangsembou Bungnamei Anup Saikia Dhrubajyoti Sahariah William Narzary Olha Danylo Tobias Sturn Mathias Karner Ian McCallum Dmitry Schepaschenko Elena Moltchanova Dilek Fraisl Inian Moorthy Steffen Fritz 《Global Change Biology》2019,25(1):174-186
There is an increasing evidence that smallholder farms contribute substantially to food production globally, yet spatially explicit data on agricultural field sizes are currently lacking. Automated field size delineation using remote sensing or the estimation of average farm size at subnational level using census data are two approaches that have been used. However, both have limitations, for example, automatic field size delineation using remote sensing has not yet been implemented at a global scale while the spatial resolution is very coarse when using census data. This paper demonstrates a unique approach to quantifying and mapping agricultural field size globally using crowdsourcing. A campaign was run in June 2017, where participants were asked to visually interpret very high resolution satellite imagery from Google Maps and Bing using the Geo‐Wiki application. During the campaign, participants collected field size data for 130 K unique locations around the globe. Using this sample, we have produced the most accurate global field size map to date and estimated the percentage of different field sizes, ranging from very small to very large, in agricultural areas at global, continental, and national levels. The results show that smallholder farms occupy up to 40% of agricultural areas globally, which means that, potentially, there are many more smallholder farms in comparison with the two different current global estimates of 12% and 24%. The global field size map and the crowdsourced data set are openly available and can be used for integrated assessment modeling, comparative studies of agricultural dynamics across different contexts, for training and validation of remote sensing field size delineation, and potential contributions to the Sustainable Development Goal of Ending hunger, achieve food security and improved nutrition and promote sustainable agriculture. 相似文献
440.
Karolina Augustyniak Karolina Chrabaszcz Agnieszka Jasztal Marta Smeda Guillermo Quintas Julia Kuligowski Katarzyna M. Marzec Kamilla Malek 《Journal of biophotonics》2019,12(4)
Using high definition (HD) and ultra‐high definition (UHD) of Fourier‐transform infrared (FTIR) spectroscopic imaging, we characterized spectrally pulmonary metastases in a murine model of breast cancer comparing them with histopathological results (Hematoxylin and eosin [H&E] staining). This comparison showed excellent agreement between the methods in case of localization of metastases with size below 1 mm and revealed that label‐free HD and UHD IR spectral histopathology distinguish the type of neoplastic cells. We primary focused on differentiation between metastatic foci in the pleural cavity from cancer cells present in lung parenchyma and inflamed cells present in extracellular matrix of lungs due to growing of advanced metastases. In addition, a combination of unsupervised clustering and IR imaging indicated the high sensitivity of FTIR spectroscopy to identify chemical features of small macrometastases located under the pleural cavity and during epithelial‐mesenchymal transition. FTIR‐based spectral histopathology was proved to detect not only phases of breast cancer metastasis to lungs but also to differentiate various origins of metastases seeded from breast cancer. 相似文献