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排序方式: 共有419条查询结果,搜索用时 906 毫秒
91.
92.
The list of immunodeficiency diseases grows each year as novel disorders are discovered, classified, and sometimes reclassified due to our ever‐increasing knowledge of immune system function. Although the number of patients with secondary immunodeficiencies (SIDs) greatly exceeds those with primary immunodeficiencies (PIDs), the prevalence of both appears to be on the rise probably because of scientific breakthroughs that facilitate earlier and more accurate diagnosis. Primary immunodeficiencies in adults are not as rare as once thought. Globally, the main causes of secondary immunodeficiency are HIV infection and nutritional insufficiencies. Persons with acquired immune disorders such as AIDS caused by the human immunodeficiency virus (HIV) are now living long and fulfilling lives as a result of highly active antiretroviral therapy (HAART). Irrespective of whether the patient's immune‐deficient state is a consequence of a genetic defect or is secondary in nature, dental and medical practitioners must be aware of the constant potential for infections and/or expressions of autoimmunity in these individuals. The purpose of this review was to study the most common conditions resulting from primary and secondary immunodeficiency states, how they are classified, and the detrimental manifestations of these disorders on the periodontal and oral tissues. 相似文献
93.
94.
Abnormal stimulated adherence of neonatal granulocytes: impaired induction of surface Mac-1 by chemotactic factors or secretagogues 总被引:10,自引:0,他引:10
To identify possible secretory determinants of impaired hyperadherence and stimulated migration of neonatal granulocytes (NGs), we performed correlative studies of: (a) specific granule content and exocytosis, (b) secretago-gue-mediated upregulation of f-met-leu-phe (fMLP) receptors, (c) the chemotactic induction of the adhesive glycoproteins Mac-1 alpha (complement receptor 3) and beta, and (d) morphometric assessments of specific (peroxidase negative) granule depletion following chemotactic stimulation. Lactoferrin (LF) content of NG suspensions (cord blood or peripheral blood cells) was profoundly diminished (mean +/- SD 51% +/- 18% of normal) as compared with healthy adult granulocytes (AGs). Despite diminished cellular content, LF release by NG suspensions in response to fMLP was comparable to that of AGs. In contrast, LF release by NG suspensions was significantly diminished in response to phorbol myristate acetate (PMA) or calcium ionophor A23187 and/or during stimulated cell spreading, experimental conditions promoting overall greater LF depletion than chemotactic stimuli. In addition, NGs demonstrated an impaired capacity to upregulate fMLP receptors in response to PMA or A23187 when tested under the same experimental conditions. Baseline expression of the adhesive glycoproteins Mac-1 alpha and beta on NG surfaces was normal, but induction or upregulation of these proteins by chemotactic concentrations of fMLP, C5a as well as secretory (high) concentrations of PMA and A23187, was significantly diminished as compared with AGs. In contrast, chemotactic induction of the surface expression of the complement receptor-1 (CR-1) on NGs was normal. An impaired induction of Mac-1 alpha or beta was directly related to an impaired enhancement of adherence of NG in response to fMLP over a chemotactically relevant concentration range (10(-10) to 10(-7) mol/L). Moreover, in blocking- incubation experiments using anti-Mac-1 alpha/beta monoclonal antibodies (MAbs), significantly less inhibition of adherence by these MAbs was evident with fMLP-stimulated NG as compared with AG suspensions. Under selected chemotactic conditions, ultrastructural assessments of NGs demonstrated diminished peroxidase-negative granule loss in association with diminished granule-membrane fusion and the "addition" of plasma membrane. These studies suggest that abnormal expression of multiple surface determinants derived from peroxidase- negative granules or other intracellular pools may contribute to deficient chemotaxis or other inflammatory functions of NGs.(ABSTRACT TRUNCATED AT 400 WORDS) 相似文献
95.
Edmond?SK?MaEmail author Chris?LP?Wong Kristi?TW?Lai Edmond?CH?Chan WC?Yam Angus?CW?Chan 《BMC infectious diseases》2005,5(1):60
Background
Kocuria, previously classified into the genus of Micrococcus, is commonly found on human skin. Two species, K. rosea and K. kristinae, are etiologically associated with catheter-related bacteremia. 相似文献96.
P-selectin mediates spontaneous leukocyte rolling in vivo 总被引:10,自引:1,他引:10
Rolling represents the initial step leading to leukocyte extravasation from blood vessels during an inflammatory reaction. In vitro studies indicate that P-selectin could be one of the ligands on endothelium involved in the rolling phenomenon, although the molecular determinants responsible for this transient attachment in vivo are still undefined. Our objectives were to develop a blocking monoclonal antibody against canine P-selectin and to use it to investigate the role of P-selectin in leukocyte rolling in vivo using the technique of intravital microscopy. P-selectin was immunoaffinity purified from canine platelets and used for the production of monoclonal antibodies. One of the hybridomas generated, MD6, was shown by enzyme-linked immunosorbent assay and by flow cytometry to bind preferentially to stimulated platelets and to completely prevent binding of stimulated platelets to neutrophils. Visualization of canine mesenteric venules by intravital microscopy showed that administration of MD6 resulted in a marked inhibition in the number of rolling leukocytes (18.96 +/- 9.92 v 156.40 +/- 19.50 leukocytes/min, P < .05; 88.3% +/- 6.0% inhibition). Control antibody MD3 (which recognizes a nonfunctional epitope of canine P- selectin) had no effect on the number of rolling leukocytes or on their rolling velocity. These results show for the first time that P-selectin plays an essential role in leukocyte rolling in vivo, and therefore may be a key participant of the inflammatory response. 相似文献
97.
Heparin cofactor II-proteinase reaction products exhibit neutrophil chemoattractant activity 总被引:1,自引:0,他引:1
The physiologic function of the plasma glycoprotein heparin cofactor II (HCII) is not well understood. An in vivo role for thrombin (IIa) inhibition by HCII in the presence of certain glycosaminoglycans (dermatan sulfate and heparin) can be proposed. Many proteins, such as complement components, can be proteolyzed to generate secondary bioactive molecules. HCII is a substrate for the human neutrophil (PMN) proteinases cathepsin G (CG) and elastase (LE). We found that degradation of HCII by CG or LE generated products with potent PMN chemotactic activity, which did not stimulate the PMN oxidative burst. Our results suggest that HCII may be a physiologic regulator of the acute inflammatory response. 相似文献
98.
Morosetti R; Grignani F; Liberatore C; Pelicci PG; Schiller GJ; Kizaki M; Bartram CR; Miller CW; Koeffler HP 《Blood》1996,87(10):4399-4403
Retinoids are important regulators of cell growth and differentiation in vitro and in vivo and they exert their biologic activities by binding to nuclear retinoic acid receptors (RARs; alpha, beta, and gamma) and retinoid X receptors (RXRs; alpha, beta, and gamma). All- trans retinoic acid (RA) induces complete remission in patients with acute promyelocytic leukemia (APL) presumably by binding directly to RAR alpha of APL cells. Leukemic blasts from APL patients initially responsive to RA can become resistant to the agent. HL-60 myeloblasts cultured with RA have developed mutations of the ligand-binding region of RAR alpha and have become resistant to RA. Furthermore, insertion of an RAR alpha with an alteration in the ligand-binding region into normal murine bone marrow cells can result in growth factor-dependent immortalization of the early hematopoietic cells. To determine if alterations of the ligand binding domain of RAR alpha might be involved in several malignant hematologic disorders, the mutational status of this region (exons 7, 8, and 9) was examined in 118 samples that included a variety of cell lines and fresh cells from patients with myelodysplastic syndromes (MDS) and acute myeloid leukemias (AML), including 20 APL patients, 5 of whom were resistant to RA and 1 who was refractory to RA at diagnosis, using polymerase chain reaction-single- strand conformational polymorphism (PCR-SSCP) analysis and DNA sequencing. In addition, 7 of the 20 APLs were studied for alterations of the other coding exons of the gene (exons 2 through 6). No mutations of RAR alpha were detected. Although the sensitivity of PCR-SSCP analysis is less than 100%, these findings suggest that alterations of RAR alpha gene are rare and therefore other mechanisms must be involved in the onset of resistance to retinoids and in the lack of differentiation in disorders of the myeloid lineage. 相似文献
99.
Evaluation of E-rosetting human lymphocytes with OKT11 and other monoclonal antibodies 总被引:2,自引:0,他引:2
Ip SH; Rittershaus CW; Struzziero CC; Hoxie JA; Hoffman RA; Healey KW; Lifter J 《Blood》1982,60(3):795-799
Monoclonal antibody OKT11 was found to compete with sheep red blood cells for binding sites on human lymphocytes. Preincubation of lymphocytes with OKT11 eliminated E-rosette formation. In a study of 142 peripheral blood samples ranging from 1% to over 90% E-rosette- positive cells, comparison to the percent OKT11-positive cells yielded a correlation coefficient of 0.93. In normal donors, subsets of OKT11+ cells were identified using two-color immunofluorescent staining methods with OKT3, OKT4, and OKT8. On the average, approximately 13% of OKT11+ lymphocytes were OKT3- and 13% of OKT11+ lymphocytes were OKT4- and OKT8-. Based on our double antibody fluorescence intensity data, low antigen density OKT11+ lymphocytes were OKT3-. OKT4+ and OKT8+ lymphocytes in normal peripheral lymphocytes have similar OKT11 antigen density. 相似文献
100.
Aaltien Brinks Bart W Koes Aloysius CW Volkers Jan AN Verhaar Sita MA Bierma-Zeinstra 《BMC musculoskeletal disorders》2010,11(1):206