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1.
Sulfate incorporation into carbohydrate of lutropin (LH) has been studied in sheep pituitary slices using H235SO4. Labeled ovine LH was purified to homogeneity by Sephadex G-100 and carboxymethyl-Sephadex chromatography from both the incubation medium and tissue extract. Autoradiography of the gel showed only two protein bands which comigrated with the α and β subunits of ovine LH in both the purified ovine LH and the immunoprecipitate obtained with LH-specific rabbit antiserum. Furthermore, [35S]sulfate was also incorporated into several other proteins in addition to LH. The location of 35SO42? in the oligosaccharides of ovine LH was evidenced by its presence in the glycopeptides obtained by exhaustive Pronase digestion. The location and the point of attachment of sulfate in the carbohydrate unit were established by the isolation of 4-O-[35S]sulfo-N-acetylhexosaminyl-glycerols and 4-O-[35S]sulfo-N-acetylglucosaminitol from the Smith degradation products and by the release of 35SO42? by chondro-4-sulfatase. Thus, the present line of experimentation indicates the presence of sulfate on both the terminal N-acetylglucosamine and N-acetylgalactosamine in the oligosaccharide chains of the labeled ovine LH. 相似文献
2.
The kinetics of haemolysis of rabbit erythrocytes byCroton tiglium lectin was studied as a function of concentration of the lectin and erythrocytes. The length of the prelytic period decreased with increasing lectin concentrations, indicating that the secondary events at the membrane which follow the binding of the lectin to cell surface carbohydrate receptors are accelerated at higher surface concentrations of the lectin. The rate or extent of haemolysis was not affected by the inclusion of ions like K+, Ca2+ and Mg2+ in the medium or by the substitution of ionic medium by a non-ionic medium. The inhibition of haemagglutination and haemolysis of rabbit red cells byCroton tiglium lectin by antilectin rabbit serum was observed. A possible mechanism of haemolysis by the lectin is discussed. 相似文献
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Sequence analysis of the aminopeptidase C gene (pepC) from Lactobacillus helveticus CNRZ32 identified a 1,332-nucleotide open reading frame coding for a polypeptide with motifs characteristic of cysteine proteinases. Homology to the pepC gene appears to be widely distributed among lactic acid bacteria. 相似文献
5.
Hrushikesh S. Chaudhari Omkar S. Palkar KM Abha Mishra Kalyan K. Sethi 《Journal of biochemical and molecular toxicology》2023,37(9):e23417
During the period of COVID-19, the occurrences of mucormycosis in immunocompromised patients have increased significantly. Mucormycosis (black fungus) is a rare and rapidly progressing fungal infection associated with high mortality and morbidity in India as well as globally. The causative agents for this infection are collectively called mucoromycetes which are the members of the order Mucorales. The diagnosis of the infection needs to be performed as soon as the occurrence of clinical symptoms which differs with types of Mucorales infection. Imaging techniques magnetic resonance imaging or computed tomography scan, culture testing, and microscopy are the approaches for the diagnosis. After the diagnosis of the infection is confirmed, rapid action is needed for the treatment in the form of antifungal therapy or surgery depending upon the severity of the infection. Delaying in treatment declines the chances of survival. In antifungal therapy, there are two approaches first-line therapy (monotherapy) and combination therapy. Amphotericin B ( 1 ) and isavuconazole ( 2 ) are the drugs of choice for first-line therapy in the treatment of mucormycosis. Salvage therapy with posaconazole ( 3 ) and deferasirox ( 4 ) is another approach for patients who are not responsible for any other therapy. Adjunctive therapy is also used in the treatment of mucormycosis along with first-line therapy, which involves hyperbaric oxygen and cytokine therapy. There are some drugs like VT-1161 ( 5 ) and APX001A ( 6 ), Colistin, SCH 42427, and PC1244 that are under clinical trials. Despite all these approaches, none can be 100% successful in giving results. Therefore, new medications with favorable or little side effects are required for the treatment of mucormycosis. 相似文献
6.
Kalyan Rao Anumula 《Journal of molecular recognition : JMR》1993,6(3):139-145
Endo β-N-acetylglucosaminidase activities were determined based on conversion of oligosaccharides containing two N-acetylglucosamines to the oligosaccharides with a single N-acetylglucosamine at the reducing terminal and following their separation on a carbohydrate analyzer. The oligosaccharides eluted from the high performance anion exchange column in the order of fucosyl-N,N′ -diacetylchitobiose, N,N′ -diacetylchitobiose and N-acetylglucosamine containing reducing terminals. Using this assay, differences in cleavage specificity of the glycoproteins was determined. The commercial Endo F-peptide N-glycosidase/glycanyl amidase (PNGase)mixture readily leaved high mannose and complex oligosaccharides (neutral and sialyated) with common core α1–6 linked fucose found in porcine thyroglobulin including the trimannosyl-chitobiose core structure. However, the same Endo F mixture did not cleave the non-fucosylated complex oligosaccharides found in human transferrin and also the common core structure. Glycopeptide counterparts with and without fucose were good substrates for the endoglycosidases. These results show that the specificity of these enzymes is such that they can recognize the conformational differences between free oligosaccharides and glycopeptides with and without the common core α1–6 linked fucose. In contrast, highly purified Endo F cleaved only the high mannose type oligosaccharides and was unable to cleave ovalbumin hybrid type oligosaccharides. However, it was similar to Endo H when reduced ovalbumin oligosaccharides were used as substrates, consistent with the recently isolated Endo F subfraction F1 being similar to Endo H [Trimble, R. B. and Tarentino, a. L. (1991). J. Biol. Chem. 266, 1646]. Results obtained in this study suggest that the complex oligosaccharides cleaving enzymes F2 and F3 show high specificity towards peptide free oligosaccharides with the core α1-6 linked fucose, unlike the glycopeptide substrates. Therefore PNGase free Endo F1, F2 and F3 mixtures should be useful in the functional evaluation of the oligosaccharides in glycoproteins. 相似文献
7.
Ashis K. Sen Kalyan K. Sarkar Pronobesh C. Mazumder Nilima Banerji Raimo Uusvuori Tapio A. Hase 《Phytochemistry》1982,21(7):1747-1750
Three new tetraoxygenated xanthones (garcinones A, B and C), each disubstituted with C5-units, have been isolated from the chloroform extract of the fruit-hulls of Garcinia mangostana. Their structures were established by a combination of spectral interpretation and chemical correlation. 相似文献
8.
Kapoor V Paliwal D Baskar Singh S Mohanti BK Das SN 《Biochemical and biophysical research communications》2012,422(4):764-769
Autophagy is a physiologically regulated and evolutionary conserved process that plays a critical role in degradation of cytoplasmic proteins and other macromolecules within the lysosomes. Beclin-1, the mammalian orthologue of yeast Atg6, is an important mediator of autophagy that has been studied in many human cancers. However, the expression of Beclin-1 has not yet been investigated in oral cancer. We for the first time investigated the expression of Beclin-1 in serum and tissues and correlated it with the clinic-pathological features of oral cancer patients. m-RNA expression of Beclin-1 was evaluated in tumor and normal areas of surgical specimens from 10 oral cancer patients by real-time PCR. Approximately, 8-fold lower expression (p<0.001) of Beclin-1 mRNA was observed in tumor tissue as compared to the normal tissue. Serum levels of Beclin-1 were evaluated by SPR and ELISA. No significant difference was observed in serum Beclin-1 levels in patients as compared to healthy subjects, similarly no correlation was found between serum levels and clinic-pathological parameters such as stage, lymph node involvement and tumor size. Our results demonstrate that down-regulation of Beclin-1 may play an important role in the development and progression of oral cancer possibly by dysregulation of autophagy in tumor cells. 相似文献
9.
Priya Gogoi Saedeh Sepehri Yi Zhou Michael A. Gorin Carmela Paolillo Ettore Capoluongo Kyle Gleason Austin Payne Brian Boniface Massimo Cristofanilli Todd M. Morgan Paolo Fortina Kenneth J. Pienta Kalyan Handique Yixin Wang 《PloS one》2016,11(1)
Current analysis of circulating tumor cells (CTCs) is hindered by sub-optimal sensitivity and specificity of devices or assays as well as lack of capability of characterization of CTCs with clinical biomarkers. Here, we validate a novel technology to enrich and characterize CTCs from blood samples of patients with metastatic breast, prostate and colorectal cancers using a microfluidic chip which is processed by using an automated staining and scanning system from sample preparation to image processing. The Celsee system allowed for the detection of CTCs with apparent high sensitivity and specificity (94% sensitivity and 100% specificity). Moreover, the system facilitated rapid capture of CTCs from blood samples and also allowed for downstream characterization of the captured cells by immunohistochemistry, DNA and mRNA fluorescence in-situ hybridization (FISH). In a subset of patients with prostate cancer we compared the technology with a FDA-approved CTC device, CellSearch and found a higher degree of sensitivity with the Celsee instrument. In conclusion, the integrated Celsee system represents a promising CTC technology for enumeration and molecular characterization. 相似文献
10.
Kalyan C. Tirupula Dongmei Zhang Appledene Osbourne Arunachal Chatterjee Russ Desnoyer Belinda Willard Sadashiva S. Karnik 《PloS one》2015,10(10)
Propagation of signals from G protein-coupled receptors (GPCRs) in cells is primarily mediated by protein-protein interactions. MAS is a GPCR that was initially discovered as an oncogene and is now known to play an important role in cardiovascular physiology. Current literature suggests that MAS interacts with common heterotrimeric G-proteins, but MAS interaction with proteins which might mediate G protein-independent or atypical signaling is unknown. In this study we hypothesized that MAS C-terminal tail (Ct) is a major determinant of receptor-scaffold protein interactions mediating MAS signaling. Mass-spectrometry based proteomic analysis was used to comprehensively identify the proteins that interact with MAS Ct comprising the PDZ-binding motif (PDZ-BM). We identified both PDZ and non-PDZ proteins from human embryonic kidney cell line, mouse atrial cardiomyocyte cell line and human heart tissue to interact specifically with MAS Ct. For the first time our study provides a panel of PDZ and other proteins that potentially interact with MAS with high significance. A ‘cardiac-specific finger print’ of MAS interacting PDZ proteins was identified which includes DLG1, MAGI1 and SNTA. Cell based experiments with wild-type and mutant MAS lacking the PDZ-BM validated MAS interaction with PDZ proteins DLG1 and TJP2. Bioinformatics analysis suggested well-known multi-protein scaffold complexes involved in nitric oxide signaling (NOS), cell-cell signaling of neuromuscular junctions, synapses and epithelial cells. Majority of these protein hits were predicted to be part of disease categories comprising cancers and malignant tumors. We propose a ‘MAS-signalosome’ model to stimulate further research in understanding the molecular mechanism of MAS function. Identifying hierarchy of interactions of ‘signalosome’ components with MAS will be a necessary step in future to fully understand the physiological and pathological functions of this enigmatic receptor. 相似文献