全文获取类型
收费全文 | 1039篇 |
免费 | 0篇 |
专业分类
化学工业 | 7篇 |
能源动力 | 1篇 |
轻工业 | 2篇 |
冶金工业 | 1029篇 |
出版年
2022年 | 1篇 |
2019年 | 1篇 |
2010年 | 1篇 |
2009年 | 1篇 |
2008年 | 1篇 |
2005年 | 2篇 |
2003年 | 1篇 |
1999年 | 18篇 |
1998年 | 307篇 |
1997年 | 202篇 |
1996年 | 117篇 |
1995年 | 68篇 |
1994年 | 59篇 |
1993年 | 54篇 |
1992年 | 7篇 |
1991年 | 15篇 |
1990年 | 8篇 |
1989年 | 9篇 |
1988年 | 19篇 |
1987年 | 13篇 |
1986年 | 8篇 |
1985年 | 8篇 |
1983年 | 2篇 |
1982年 | 6篇 |
1981年 | 8篇 |
1980年 | 7篇 |
1978年 | 7篇 |
1977年 | 28篇 |
1976年 | 59篇 |
1975年 | 1篇 |
1954年 | 1篇 |
排序方式: 共有1039条查询结果,搜索用时 15 毫秒
91.
KG Birukov JP Schavocky VP Shirinsky MV Chibalina LJ Van Eldik DM Watterson 《Canadian Metallurgical Quarterly》1998,70(3):402-413
We report that the genetic locus that encodes vertebrate smooth muscle and nonmuscle myosin light chain kinase (MLCK) and kinase-related protein (KRP) has a complex arrangement and a complex pattern of expression. Three proteins are encoded by 31 exons that have only one variation, that of the first exon of KRP, and the genomic locus spans approximately 100 kb of DNA. The three proteins can differ in their relative abundance and localization among tissues and with development. MLCK is a calmodulin (CaM) regulated protein kinase that phosphorylates the light chain of myosin II. The chicken has two MLCK isoforms encoded by the MLCK/KRP locus. KRP does not bind CaM and is not a protein kinase. However, KRP binds to and regulates the structure of myosin II. Thus, KRP and MLCK have the same subcellular target, the myosin II molecular motor system. We examined the tissue and cellular localization of KRP and MLCK in the chicken embryo and in adult chicken tissues. We report on the selective localization of KRP and MLCK among and within tissues and on a differential distribution of the proteins between embryonic and adult tissues. The results fill a void in our knowledge about the organization of the MLCK/KRP genetic locus, which appears to be a late evolving regulatory paradigm, and suggest an independent and complex regulation of expression of the gene products from the MLCK/KRP genetic locus that may reflect a basic principle found in other eukaryotic gene clusters that encode functionally linked proteins. 相似文献
92.
93.
The Helix pomatia agglutinin (HPA)-binding glycoproteins from primary breast cancers and their metastases were compared with appropriate normal control tissues on Western blots. From these studies a single glycoprotein of 55 kDa was found to bind HPA in tumours but not in normal control tissues. The glycoprotein was identified by protein sequencing as being homologous to human immunoglobulin heavy chain variable region. Subsequent immunostaining showed it to be immunoglobulin subclass A. IgA1 was purified from both tumour and normal tissue by affinity chromatography. It was demonstrated that IgA1 from tumour tissue bound HPA whereas IgA1 from normal tissue did not. The oligosaccharides were cleaved from the protein backbone and the glycans from the HPA-binding glycoform of IgA1 were compared with those from normal human IgA1. IgA1 from tumour tissue appears to be associated with an HPA-binding glycan which is not present on the normal tissue-derived IgA1. 相似文献
94.
DL Smalley JJ Levine DR Shanklin MF Hall MV Stevens 《Canadian Metallurgical Quarterly》1996,196(5):567-574
The current study evaluated immune response to silicon dioxide in children born to women with silicone breast implants. In part one of the study, the T lymphocytes of 21 of 24 such children were significantly stimulated by silicon dioxide (silica). Part two consisted of eleven children, four born preimplantation and seven born postimplantation. None of the preimplant offspring showed T cell responses to silica; five of the seven postimplant children were positive for T cell memory for silica. Part three was a blinded study based on statistically significant differences in T cell stimulation with silicon dioxide between postimplant children and controls. These findings indicate a common immune reaction, that of T cell memory, occurs in mothers and their children born after exposure to silicone mammary implants placed prior to pregnancy. Since not all such children were breast fed the result favors transplacental passage of immunogens such as silicone oligomers or through maternofetal cellular traffic. 相似文献
95.
We isolated a polymorphic dinucleotide (CA) repeat sequence from a genomic clone containing the human progesterone receptor (PGR) gene. This polymorphism will be a useful marker in the genetic study of disorders affecting female endocrine systems, such as progesterone resistance and breast, uterine, and ovarian cancers. 相似文献
96.
97.
MV Sennitt AJ Kaumann P Molenaar LJ Beeley PW Young J Kelly H Chapman SM Henson JM Berge DK Dean NR Kotecha HK Morgan HK Rami RW Ward M Thompson S Wilson SA Smith MA Cawthorne MJ Stock JR Arch 《Canadian Metallurgical Quarterly》1998,285(3):1084-1095
The role of beta3- and other putative atypical beta-adrenoceptors in human white adipocytes and right atrial appendage has been investigated using CGP 12177 and novel phenylethanolamine and aryloxypropanolamine beta3-adrenoceptor (beta3AR) agonists with varying intrinsic activities and selectivities for human cloned betaAR subtypes. The ability to demonstrate beta1/2AR antagonist-insensitive (beta3 or other atypical betaAR-mediated) responses to CGP 12177 was critically dependent on the albumin batch used to prepare and incubate the adipocytes. Four aryloxypropanolamine selective beta3AR agonists (SB-226552, SB-229432, SB-236923, SB-246982) consistently elicited beta1/2AR antagonist-insensitive lipolysis. However, a phenylethanolamine (SB-220646) that was a selective full beta3AR agonist elicited full lipolytic and inotropic responses that were sensitive to beta1/2AR antagonism, despite it having very low efficacies at cloned beta1- and beta2ARs. A component of the response to another phenylethanolamine selective beta3AR agonist (SB-215691) was insensitive to beta1/2AR antagonism in some experiments. Because no [corrected] novel aryloxypropanolamine had a beta1/2AR antagonist-insensitive inotropic effect, these results establish more firmly that beta3ARs mediate lipolysis in human white adipocytes, and suggest that putative 'beta4ARs' mediate inotropic responses to CGP 12177. The results also illustrate the difficulty of predicting from studies on cloned betaARs which betaARs will mediate responses to agonists in tissues that have a high number of beta1- and beta2ARs or a low number of beta3ARs. 相似文献
98.
99.
EA Vagner VA Bruns OT Artemov AV Kasatov MV Altyntsev 《Canadian Metallurgical Quarterly》1998,(9):62-64
During 20 years (1972-1994) the authors carried out proximal resections of the stomach in 106 patients for cancer of proximal part of the stomach extended to the esophagus. Morphological verification data are presented. Total lethality rate made up 20.8%. It decreased with gaining of experience and improvement in selection of patients (1972-1982--29.6%, 1983-1994--17.7%). The most common complication in postoperative period was exudative pleuritis: in 16% of operated patients insufficiency of sutures of the esophagogastric anastomosis was observed. For prophylaxis of suture insufficiency pyloroplasty by Heineke-Mikulich and continuous (to 4-5 days) naso-gastral drainage were of principal significance. Great importance was attached to establishment of the anastomosis by the method developed by the authors. The results of the operations depend also on the operative approach: two-stage combined approach (laparotomy, thoracotomy) brings the least lethality. 相似文献
100.
Respiration-dependent responses of a pH probe (fluorescein isothiocyanate, FITC), covalently bound to the membrane proteins of mitochondria and submitochondrial particles (SMP) have been studied. A spectral shift indicating FITC deprotonation was observed when respiration was activated in coupled mitochondria. Such a response was increased by valinomycin and reduced by uncoupler. Some FITC deprotonation was detected in the presence of excess of an uncoupler, but the response was smaller and insensitive to valinomycin. FITC deprotonation was also observed in submitochondrial particles after succinate addition. In this case it was not affected by uncoupler. Increase in the buffer concentration was found to (i) decrease the FITC response and (ii) increase the rate of uncoupled respiration in both mitochondria and submitochondrial particles. The results are consistent with the assumption that respiration initiates appearance of local H+ activity gradients on the inner side of the internal mitochondrial membrane during the steady-state H+ pumping. We suggest that the formation of this gradient is due to kinetic barrier to proton transfer from the bulk phase to the respiratory proton pump vicinity. 相似文献