全文获取类型
收费全文 | 266篇 |
免费 | 13篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 35篇 |
儿科学 | 9篇 |
妇产科学 | 15篇 |
基础医学 | 33篇 |
口腔科学 | 3篇 |
临床医学 | 16篇 |
内科学 | 48篇 |
皮肤病学 | 8篇 |
神经病学 | 5篇 |
特种医学 | 45篇 |
外科学 | 30篇 |
综合类 | 3篇 |
预防医学 | 8篇 |
眼科学 | 2篇 |
药学 | 16篇 |
肿瘤学 | 8篇 |
出版年
2021年 | 5篇 |
2020年 | 2篇 |
2018年 | 2篇 |
2015年 | 4篇 |
2014年 | 4篇 |
2013年 | 10篇 |
2012年 | 8篇 |
2011年 | 8篇 |
2010年 | 12篇 |
2009年 | 7篇 |
2008年 | 8篇 |
2007年 | 3篇 |
2006年 | 9篇 |
2005年 | 11篇 |
2004年 | 4篇 |
2003年 | 6篇 |
2002年 | 6篇 |
2001年 | 4篇 |
1999年 | 6篇 |
1998年 | 14篇 |
1997年 | 10篇 |
1996年 | 13篇 |
1995年 | 6篇 |
1994年 | 7篇 |
1993年 | 9篇 |
1992年 | 6篇 |
1990年 | 4篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 5篇 |
1983年 | 2篇 |
1982年 | 5篇 |
1981年 | 4篇 |
1980年 | 7篇 |
1979年 | 4篇 |
1978年 | 5篇 |
1977年 | 12篇 |
1976年 | 3篇 |
1975年 | 3篇 |
1974年 | 2篇 |
1969年 | 2篇 |
1968年 | 3篇 |
1966年 | 2篇 |
1927年 | 2篇 |
1912年 | 2篇 |
1886年 | 1篇 |
1885年 | 1篇 |
1884年 | 3篇 |
1882年 | 2篇 |
排序方式: 共有284条查询结果,搜索用时 31 毫秒
271.
Summary The increasing knowledge of the structure and function of macromolecular carbohydrate-protein compounds (glycoproteins) has led to an increase in interest in these molecules in biology and especially in medicine in recent years. In saliva the largest part of the glycoproteins is constituted by the mucins. Salivary mucins exhibit very high molecular weight, have a high percentage of carbohydrate (approx. 70%) in the form of fucose, N-acetylglucosamine, N-acetylgalactosamine, galactose mannose and N-acetylneuraminic acid. They have a negative charge due to N-acetylneuraminic acid and sulphate residues, which together with the high molecular weight of these glycoproteins leads to characteristic viscous properties.The most important mucin properties which play a role in the upper respiratory and alimentory tract will be presented, especially the viscous character with respect to lubricative functions, the protection of mucous surfaces against microorganisms and other agents.A few physiological and pathological mucin analysis of human saliva and its method of analysis will be presented.
Mit Hilfe der Deutschen Forschungsgemeinschaft 相似文献
Mit Hilfe der Deutschen Forschungsgemeinschaft 相似文献
272.
273.
Human epididymal secreted protein CD52 on ejaculated spermatozoa: correlations with semen characteristics and the effect of its antibody 总被引:1,自引:2,他引:1
CD52 is a glycosylphosphatidylinositol-anchored glycoprotein secreted by
the epididymis where it is incorporated into sperm membranes. The antigen
is common to spermatozoa and lymphocytes, and its role is not known.
Quantitative analysis using immunostaining with the monoclonal antibody
CAMPATH-1G and flow cytometry indicated positive signals from approximately
80% of viable, washed ejaculated spermatozoa. Staining intensity increased
after capacitation overnight, and decreased after short incubation with
high density lipoprotein. After incubation of Percoll-washed spermatozoa
with CAMPATH-1G, motility was reduced from 83 to 74% after 5 min and from
73 to 52% after 3.5 h. Swimming velocities were reduced by approximately
30% and linearity by 15% in 5 min, but no further decreases were observed
over 3.5 h. After 20 min incubation with the antibody, cell viability was
decreased by 10 and 20% in freshly washed and capacitated spermatozoa
respectively. Comparison of fertile and infertile patients revealed no
difference in the percentages of immunostained spermatozoa or in staining
intensity and there were no differences in sperm labelling between
normozoospermia and teratozoospermia. Compared with normozoospermia,
percentages of stained spermatozoa were lower by 20 and 27% in
asthenozoospermia and oligozoospermia respectively, whereas staining
intensity in asthenozoospermia was less than half that in oligozoospermia.
The correlation of percentages of stained spermatozoa with percentages of
motile cells suggests the involvement of epididymal CD52 in the maturation
of sperm function.
相似文献
274.
Kim HY; Min JK; Yang HI; Park SH; Hong YS; Jee WH; Lee SH; Cho CS; Kim TG; Han H 《Rheumatology (Oxford, England)》1997,36(4):440-443
Many reports have described HLA-DRB1 genes as having an influence on
disease severity and susceptibility in rheumatoid arthritis (RA). Studies
were undertaken to define the effect of RA-associated alleles on disease
severity in Korean patients with seropositive RA. The results indicate that
the most common RA susceptibility allele, HLA- DRB1*0405, is significantly
associated with bony erosion, joint deformity and extra-articular
manifestations. However, RA-associated alleles in Koreans have less effect
on nodular disease than in Caucasians. This suggests that the presence of
RA-associated alleles, especially HLA-DRB1*0405, seems to be a prognostic
marker for severe erosive disease in Koreans.
相似文献
275.
Binding and internalization of recombinant human erythropoietin in murine erythroid precursor cells 总被引:4,自引:0,他引:4
Erythropoietin (EPO) biosynthetically labelled with [35S]cysteine was produced from Chinese hamster ovary (CHO) cells containing amplified copies of human EPO cDNA. The glycosylated recombinant [35S]EPO, purified to virtual radiochemical homogeneity, was biologically active. We studied the interaction of this labeled recombinant EPO with erythroid precursor cells from mice made anemic with phenylhydrazine. The [35S]-labeled molecule bound to erythroid precursors in a time- and temperature-dependent manner. The binding was specific for EPO, and neither insulin, transferrin, epidermal growth factor, nor multiplication stimulating activity could compete for EPO binding sites. In the presence of 0.2% sodium azide, which blocks 80% to 90% of internalization, the recombinant molecule bound with an apparent Kd of 750 pmol/L and 100 to 200 binding sites per cell at 37 degrees C. Asialo-EPO was a more effective competitor than sialated EPO for the available binding sites. Thus, the enhanced biological specific activity of asialo-EPO could result from its enhanced binding affinity. We also studied recombinant human EPO labeled with 125I and found that it also bound to the erythroid cells in a saturable and specific manner. After 90 minutes of incubation at 37 degrees C, most of the bound [35S]EPO was internalized, whereas most of the [125I]EPO remained on the cell surface. The reduced internalization of the iodinated molecule could account for the previously reported functional deficit associated with iodination. 相似文献
276.
R Cuenca TG Blanchard SJ Czinn JG Nedrud TP Monath CK Lee RW Redline 《Gastroenterology》1996,110(6):1770-1775
BACKGROUND & AIMS: Helicobacter infection of the gastric antrum is responsible for a number of gastric disorders. Antibiotic therapy is lengthy and is not always effective. It has been shown previously that oral immunization against Helicobacter felis in mice can prevent colonization after challenge. The aim of this study was to investigate the efficacy of therapeutic immunization in eradicating an established Helicobacter infection and in reducing gastritis. METHODS: Domestic ferrets, confirmed to be infected with Helicobacter mustelae by gastric endoscopy, were orally immunized with varying doses of purified Helicobacter pylori urease in combination with the mucosal adjuvant cholera toxin. Ferrets were assessed 1 week and 6 weeks after treatment for infection and pathology. RESULTS: Therapeutic immunization eradicated Helicobacter colonization in 30% of all immunized ferrets, although there was no difference in efficacy between the varying doses of antigen tested. The difference was statistically significant when compared with animals administered cholera toxin alone or buffer (P = 0.04). The intensity of inflammation was also significantly reduced in immunized animals (P = 0.0003). CONCLUSIONS: Oral immunization with purified H. pylori urease and cholera toxin can eradicate H. mustelae in a natural host pathogen model. Oral immunization of chronically infected animals markedly reduced gastric inflammation. (Gastroenterology 1996 Jun;110(6):1770-5) 相似文献
277.
278.
The efficacy of oxime treatment in soman poisoning is limited due to rapid aging of inhibited acetylcholinesterase (AChE). Pre-treatment with carbamates was shown to improve antidotal treatment substantially. Recently, by using a dynamically working in vitro model with real-time determination of membrane-bound AChE activity, we were able to demonstrate that pre-inhibition of human erythrocyte AChE with pyridostigmine or physostigmine resulted in a markedly higher residual AChE activity after inhibition by soman or paraoxon than in the absence of reversible inhibitors. The purpose of the present study was to compare the effect of carbamate pre-treatment and soman challenge with human erythrocyte and muscle homogenate AChE. Both enzyme sources were immobilized on particle filters which were perfused with acetylthiocholine, Ellman's reagent and phosphate buffer. AChE activity was continuously analyzed in a flow-through detector. Pre-inhibition of AChE with pyridostigmine or physostigmine resulted in a concentration-dependent increase in carbamylation, residual activity after soman inhibition and fraction of decarbamylation AChE after discontinuation of the inhibitors without differences between human erythrocyte and muscle AChE. This data support the view that human erythrocyte AChE is an adequate surrogate marker for synaptic AChE in OP poisoning. 相似文献
279.
Bumm T Müller C Al-Ali HK Krohn K Shepherd P Schmidt E Leiblein S Franke C Hennig E Friedrich T Krahl R Niederwieser D Deininger MW 《Blood》2003,101(5):1941-1949
Chronic myelogenous leukemia (CML) is characterized by the presence of a Bcr-Abl fusion protein with deregulated tyrosine kinase activity that is required for maintaining the malignant phenotype. Imatinib, a selective inhibitor of Bcr-Abl, induces major cytogenetic remission (MCR) or complete cytogenetic remission (CCR) in the majority of patients with CML in first chronic phase. However, thorough re-evaluation of cytogenetics in a cohort of patients in MCR or CCR demonstrated clonal karyotypic abnormalities in more than 10% of cases, some of which were clinically associated with a myelodysplastic syndrome (MDS). Further analysis identified previous exposure to cytarabine and idarubicin as significant risk factors for the subsequent occurrence of abnormalities in Philadelphia chromosome-negative (Ph-) cells. To investigate if cytogenetically normal but clonal hematopoiesis might be present in other patients in cytogenetic remission, we studied X-chromosome inactivation as a marker of clonality by polymerase chain reaction analysis of the human androgen receptor (HUMARA). We find that imatinib restores a polyclonal pattern in most patients in CCR and MCR. Nonetheless, our results are consistent with the notion that targeted therapy of CML with imatinib favors the manifestation of Ph- clonal disorders in some patients. They indicate that patients on imatinib should be followed with conventional cytogenetics, even after induction of CCR. 相似文献
280.
Angela Giudice Ilza Camada Paulo TG Leopoldo Júlia MB Pereira Lee W Riley Mary E Wilson John L Ho Amelia Ribeiro de Jesus Edgar M Carvalho Roque P Almeida 《BMC infectious diseases》2007,7(1):7