全文获取类型
收费全文 | 1070篇 |
免费 | 1篇 |
专业分类
化学工业 | 6篇 |
矿业工程 | 1篇 |
轻工业 | 2篇 |
石油天然气 | 1篇 |
无线电 | 7篇 |
一般工业技术 | 3篇 |
冶金工业 | 1041篇 |
自动化技术 | 10篇 |
出版年
2022年 | 1篇 |
2017年 | 1篇 |
2013年 | 1篇 |
2006年 | 2篇 |
2005年 | 2篇 |
2004年 | 2篇 |
2000年 | 1篇 |
1999年 | 34篇 |
1998年 | 341篇 |
1997年 | 185篇 |
1996年 | 127篇 |
1995年 | 57篇 |
1994年 | 47篇 |
1993年 | 63篇 |
1992年 | 7篇 |
1991年 | 6篇 |
1990年 | 11篇 |
1989年 | 11篇 |
1988年 | 17篇 |
1987年 | 7篇 |
1986年 | 9篇 |
1985年 | 8篇 |
1983年 | 4篇 |
1982年 | 7篇 |
1981年 | 2篇 |
1980年 | 12篇 |
1978年 | 3篇 |
1977年 | 24篇 |
1976年 | 72篇 |
1974年 | 1篇 |
1967年 | 3篇 |
1966年 | 1篇 |
1955年 | 2篇 |
排序方式: 共有1071条查询结果,搜索用时 0 毫秒
101.
RH Wiesner AJ Demetris SH Belle EC Seaberg JR Lake RK Zetterman J Everhart KM Detre 《Canadian Metallurgical Quarterly》1998,28(3):638-645
Hepatic allograft rejection remains an important problem following liver transplantation, and, indeed, complications related to the administration of immunosuppressive therapy remain a predominant cause of posttransplantation morbidity and mortality. The Liver Transplantation Database (LTD) was used to study a cohort of 762 consecutive adult liver transplantation recipients and determined the incidence, timing, and risk factors for acute rejection. We also evaluated the impact of histological severity of rejection on the need for additional immunosuppressive therapy and on patient and graft survival. Four hundred ninety (64%) of the 762 adult liver transplantation recipients developed at least one episode of rejection during a median follow-up period of 1,042 days (range, 336-1,896 days), most of which occurred during the first 6 weeks after transplantation. Multivariate analysis revealed that recipient age, serum creatinine, aspartate transaminase (AST) level, presence of edema, donor/recipient HLA-DR mismatch, cold ischemic time, and donor age were independently associated with the time to acute rejection. An interesting observation was that the histological severity of rejection was an important prognosticator: the use of antilymphocyte preparations was higher, and the time to death or retransplantation was shorter, for patients with severe rejection. Findings from this study will assist in decision-making for the use of immunosuppressive regimens and call into question whether complete elimination of all rejection or alloreactivity is a desirable goal in liver transplantation. 相似文献
102.
103.
104.
HW Halbe NR de Melo L Bahamondes A Petracco M Lemgruber RP de Andrade DC da Cunha CA Guazelli EC Baracat 《Canadian Metallurgical Quarterly》1998,3(3):113-120
In this study, we have examined the effects of authentic nitric oxide (NO), NO+ (NOBF4), glutathione (GSH), glutathione disulphide (GSSG), and S-nitrosoglutathione (GSNO) in the presence and absence of Cu2+, which thermally releases NO from S-nitrosothiols on the transport of L-arginine into the human platelet. The K(M,apparent) was unaffected by NO, NO+, GSH, and GSNO. However, Cu2+ lowered K(M,apparent) by approximately 2.85-fold. Cu2+-dependent lowering of K(M,apparent) was also observed, albeit to a smaller extent when this ion was mixed with GSH (approximately 1.9-fold lower) and GSNO (approximately 2.0-fold). GSSG also lowered K(M,apparent) by approximately 1.5-fold. The Vmax,apparent of L-arginine uptake was unaffected by NO, NO+, GSH, and Cu2+. Vmax,apparent was stimulated by to the largest extent by GSNO (approximately 2.28-fold) and GSNO plus Cu2+ (approximately 2.7-fold). GSSG and GSH plus Cu2+ also increased Vmax,apparent by approximately 1.9-fold. When these parameters are expressed in terms of transport efficiency (Vmax/K(M)) the largest effect of nearly 4.7-fold (over controls) was obtained by a combination of GSNO plus Cu2+. These results suggest that platelet L-Arg transport is not affected either by NO or NO+ but by a thiol-disulphide exchange reactions on the platelet L-Arg transporter, brought about by GSNO and GSSG. Based on these results, a GSNO/GSSG/Cu2+ dependent regulatory mechanism for the uptake of L-arginine in human platelets has been proposed. 相似文献
105.
The most common tumoral lesion of the bony orbital region is osteoma. It is an infrequent and benign tumor, and generally attacks the craniofacial skeleton, but intraorbital involvement is extremely rare. After necessary radiologic examinations (radiographs and computed tomography scanning), surgery should be planned according to the tumor's localization. In the case presented here, osteoma originated mainly from the medial orbital wall. Therefore, for better surgical exposure, extra- and intracranial approaches were planned and carried out. The mass was removed successfully. At the 3-year follow-up, no recurrence was shown. 相似文献
106.
Girth measurements provide a simple method for estimation of total body fat that can be used over a wide range of percentage body fat (%BF). Well-established equations for determining %BF from girth measurements were applied to 42 Caucasian and 40 Polynesian women. %BF was determined from total body water measurement using oxygen-18 dilution. The relationship between the criterion measurement of %BF and that calculated from girth measurements differed significantly between the two ethnic groups. Assessment of body fat using girth measurements should use ethnicity-specific equations. 相似文献
107.
108.
Suitable measures of health and morbidity are less readily available for children than they are for adults. We present a measure, which is used to describe the impact of impairment and disability on the lives of children with cerebral palsy and their families. The development of this measure involved data collected from 691 children with cerebral palsy contained within the North-East England Cerebral Palsy Register and born between 1960 and 1985. Uniquely, multidimensional scaling techniques were used to derive dimensions analogous with those described in the International Classification of Impairments, Disabilities, and Handicaps. We present the analyses undertaken to test the properties of the tool, which show that it is a reliable and valid measure of the disadvantages experienced by children with cerebral palsy. 相似文献
109.
We cloned the MLSB resistance determinant by PCR from a clinical isolate of Enterococcus faecalis 373, which is induced more strongly by a 16-membered-ring macrolide, tylosin, than by erythromycin. To elucidate the molecular basis of resistance of E. faecalis 373, we analyzed the cloned gene, designated ermAMR, by site-directed mutagenesis and reporter gene assay. Our results showed that an arginine-to-cysteine change in the seventh codon of the putative leader peptide endowed tylosin with resistance inducibility and that TAAA duplication enabled the control region to express the downstream methylase gene at a drastically increased level. 相似文献
110.
D Ziemnicka-Kotula J Xu H Gu A Potempska KS Kim EC Jenkins E Trenkner L Kotula 《Canadian Metallurgical Quarterly》1998,273(22):13681-13692
Spectrin is a widely expressed protein with specific isoforms found in erythroid and nonerythroid cells. Spectrin contains an Src homology 3 (SH3) domain of unknown function. A cDNA encoding a candidate spectrin SH3 domain-binding protein was identified by interaction screening of a human brain expression library using the human erythroid spectrin (alphaI) SH3 domain as a bait. Five isoforms of the alphaI SH3 domain-binding protein mRNA were identified in human brain. Mapping of SH3 binding regions revealed the presence of two alphaI SH3 domain binding regions and one Abl-SH3 domain binding region. The gene encoding the candidate spectrin SH3 domain-binding protein has been located to human chromosome 10p11.2 --> p12. The gene belongs to a recently identified family of tyrosine kinase-binding proteins, and one of its isoforms is identical to e3B1, an eps8-binding protein (Biesova, Z., Piccoli, C., and Wong, W. T. (1997)Oncogene 14, 233-241). Overexpression of the green fluorescent protein fusion of the SH3 domain-binding protein in NIH3T3 cells resulted in cytoplasmic punctate fluorescence characteristic of the reticulovesicular system. This fluorescence pattern was similar to that obtained with the anti-human erythroid spectrin alphaI SigmaI/betaI SigmaI antibody in untransfected NIH3T3 cells; in addition, the anti-alphaI SigmaI/betaI SigmaI antibody also stained Golgi apparatus. Immunofluorescence obtained using antibodies against alphaI SigmaI/++betaI SigmaI spectrin and Abl tyrosine kinase but not against alphaII/betaII spectrin colocalized with the overexpressed green fluorescent protein-SH3-binding protein. Based on the conservation of the spectrin SH3 binding site within members of this protein family and published interactions, a general mechanism of interactions of tyrosine kinases with the spectrin-based membrane skeleton is proposed. 相似文献