全文获取类型
收费全文 | 9949篇 |
免费 | 613篇 |
国内免费 | 80篇 |
专业分类
耳鼻咽喉 | 63篇 |
儿科学 | 257篇 |
妇产科学 | 307篇 |
基础医学 | 1536篇 |
口腔科学 | 242篇 |
临床医学 | 815篇 |
内科学 | 2244篇 |
皮肤病学 | 233篇 |
神经病学 | 1035篇 |
特种医学 | 343篇 |
外科学 | 1000篇 |
综合类 | 54篇 |
一般理论 | 5篇 |
预防医学 | 800篇 |
眼科学 | 194篇 |
药学 | 667篇 |
中国医学 | 55篇 |
肿瘤学 | 792篇 |
出版年
2024年 | 11篇 |
2023年 | 107篇 |
2022年 | 242篇 |
2021年 | 362篇 |
2020年 | 234篇 |
2019年 | 280篇 |
2018年 | 321篇 |
2017年 | 244篇 |
2016年 | 291篇 |
2015年 | 329篇 |
2014年 | 412篇 |
2013年 | 494篇 |
2012年 | 801篇 |
2011年 | 826篇 |
2010年 | 418篇 |
2009年 | 406篇 |
2008年 | 590篇 |
2007年 | 656篇 |
2006年 | 588篇 |
2005年 | 600篇 |
2004年 | 518篇 |
2003年 | 429篇 |
2002年 | 379篇 |
2001年 | 77篇 |
2000年 | 69篇 |
1999年 | 83篇 |
1998年 | 85篇 |
1997年 | 69篇 |
1996年 | 57篇 |
1995年 | 61篇 |
1994年 | 40篇 |
1993年 | 54篇 |
1992年 | 34篇 |
1991年 | 37篇 |
1990年 | 44篇 |
1989年 | 30篇 |
1988年 | 33篇 |
1987年 | 36篇 |
1986年 | 30篇 |
1985年 | 25篇 |
1984年 | 20篇 |
1983年 | 18篇 |
1982年 | 16篇 |
1981年 | 14篇 |
1980年 | 15篇 |
1979年 | 21篇 |
1978年 | 13篇 |
1971年 | 13篇 |
1969年 | 11篇 |
1966年 | 11篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
Mannoprotein from Cryptococcus neoformans promotes T-helper type 1 anticandidal responses in mice
下载免费PDF全文
![点击此处可从《Infection and immunity》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Pietrella D Mazzolla R Lupo P Pitzurra L Gomez MJ Cherniak R Vecchiarelli A 《Infection and immunity》2002,70(12):6621-6627
We previously demonstrated that mannoprotein (MP) from Cryptococcus neoformans (CnMP) stimulates interleukin-12 production by human monocytes, thus fostering a T-helper type 1 (Th1) protective anticryptococcal response. In this paper we show that CnMP was also able to induce a Candida albicans-directed protective Th1 response. This was demonstrated for mice immunized with CnMP by induction of a delayed-type hypersensitivity (DTH) reaction to C. albicans MP (CaMP) as well as induction of gamma interferon production by CD4(+) and CD8(+) splenic T cells stimulated in vitro with CaMP. CnMP-immunized mice were also partially protected from lethal systemic challenge with C. albicans, as shown by prolonged median survival times and decreased fungal burden in the kidney. Much evidence supports the validity of these cross-reactive and functional Th1 responses: (i) a non-cross-reactive C. albicans antigen, such as enolase, did not produce a DTH response to CaMP; (ii) passive adoptive transfer of T cells primed with CnMP induced a DTH reaction; (iii) C. neoformans extract elicited a DTH response to CaMP; and (iv) a monoclonal antibody (7H6) directed against a major and immunodominant T-cell-stimulatory 65-kDa MP (MP65) of C. albicans also recognized discrete 100-kDa constituents of C. neoformans extracts, as well as secretory constituents of the fungus. These results suggest the presence of common Th1 antigenic determinants in the mannoproteic material of C. neoformans and C. albicans epitopes, which should be considered in devising common strategies for immunoprophylactic or immunotherapeutic control of the fungi. 相似文献
42.
Abiodun O. Johnson Isaac A. Grillo Samuel A. Adebonojo 《Journal of the National Medical Association》1980,72(4):315-318
This report documents the first recorded patient in the recent literature with an esophageal perforation and an esophagopleural fistula following chest intubation for empyema. It was treated successfully by conservative method with feeding gastrostomy. It is important to realize that tube thoracostomy drainage is not an innocuous procedure and to be alert to this complication, especially in the presence of empyema. 相似文献
43.
Elizabeth Dorus Anthony P. Amarose Donald R. Tredway Frank R. Reale Richard Hatch Lucia F. Serrano 《Clinical genetics》1979,16(4):253-259
A 24-year-old female patient was referred for evaluation of primary amenorrhea. Endocrine studies showed elevated gonadotropins, consistent with gonadal failure. At laparoscopy, a normal nulligravid uterus, normal fallopian tubes, and bilateral streak gonads were observed. Histologic studies showed that the left gonad consisted entirely of fibrous tissue, confirming the presence of streak gonads. Chromosome banding studies of peripheral blood and cultures of tissue from the left gonad demonstrated a 46,X,rcp(X;11)(q22;q13) karyotype. A review of reports of X-autosome reciprocal translocations indicated that abnormal gonadal development is associated with break-points in the mid-region of the long arm of the X chromosome. 相似文献
44.
Alessandra Renieri Maria Teresa Bassi Lucia Galli Jing Zhou Marisa Giani Mario de Marchi Andrea Ballabio 《Human mutation》1994,4(3):195-198
Alport's syndrome is characterized clinically by a nonimmune glomerulopathy, often accompanied by sensorineural hearing loss and lens abnormalities, frequently due to mutations in the COL4A5 gene. The association of AS with diffuse leiomyomatosis, a benign proliferation of smooth muscle that occurs most often in the esophagus, trachea, and female genitalia, has been reported. Recently, a deletion involving both the COL4A5 and COL4A6 genes has been reported in four unrelated families. We report an additional case with Alport's syndrome associated with leiomyomatosis carrying a deletion of both COL4A5 and COL4A6 genes. A detailed characterization of the genomic region involved in the deletion event has been performed. Our results demonstrate that the deletion removed exon l of COL4A5 and exons l and 2 of COL4A6. © 1994 Wiley-Liss, Inc. 相似文献
45.
Seropositivity for and Intestinal Colonization with Entamoeba histolytica and Entamoeba dispar in Individuals in Northeastern Brazil
下载免费PDF全文
![点击此处可从《Journal of clinical microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Lucia L. Braga Yacy Mendonca Clece A. Paiva Andrea Sales Andre L. M. Cavalcante Barbara J. Mann 《Journal of clinical microbiology》1998,36(10):3044-3045
In a slum community in northeastern Brazil 20% of a sample population was colonized with Entamoeba histolytica or Entamoeba dispar and 10.6% was colonized with E. histolytica alone. No correlation between seropositivity for anti-GalNAc lectin antibody and colonization was found. These results suggest that colonization does not necessarily produce immunity to reinfection. 相似文献
46.
We describe seven cases of invasive fibrous tumors of the trachea and major bronchi with distinctive histologies and patterns of growth. The tumors are composed of proliferating fibroblasts and have moderate nuclear pleomorphism and low mitotic activity. The tumors bear some resemblance to inflammatory pseudotumor of the lung, fibrous histiocytoma, and fibromatosis, but differ from each of these entities. The tumors are neoplastic and invade down to or between plates of cartilage. Because of their proximal location, these tumors are usually amenable to sleeve resection. Recurrence is possible. Metastasis has not occurred. Distinction from more malignant mesenchymal tumors of the trachea and bronchus will prevent unnecessarily radical surgery. 相似文献
47.
Genetic relationship between Streptococcus pneumoniae isolates from nasopharyngeal and cerebrospinal fluid of two infants with Pneumococcal Meningitis
下载免费PDF全文
![点击此处可从《Journal of clinical microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
de Andrade AL Pimenta FC Brandileone MC Laval CA Guerra ML de Andrade JG Di Fabio JL 《Journal of clinical microbiology》2003,41(8):3970-3972
The molecular epidemiology of Streptococcus pneumoniae isolates from carriage and cerebrospinal fluid (CSF) concurrently recovered from the same individual has not yet been reported. By using pulsed-field gel electrophoresis, we demonstrated the genetic linkage among strains from CSF and nasopharynges of two children with pneumococcal meningitis. 相似文献
48.
49.
Giuseppe A. Ramirez Valentina Canti Stefania Del Rosso Roberta Erra Lucia Moiola Marco Magnoni 《Autoimmunity》2020,53(1):21-27
AbstractBackground: Systemic lupus erythematosus (SLE) is associated with a constellation of complications affecting multiple organs, including neuropsychiatric manifestations (NPSLE) and ischaemic events, leading to increased long-term morbidity. Antiphospholipid antibodies (aPL) are a major determinant of vascular inflammation and thromboembolic risk. The diagnostic role of anti-phosphatidylserine/prothrombin (aPS/PT) antibodies in this setting is incompletely defined.Aim: To verify whether aPS/PT add to diagnostics and disease stratification in patients with SLE with or without other aPL.Methods: 131 consecutive patients were studied, including 20 patients with SLE and secondary antiphospholipid syndrome (APS). aPS/PT IgG and IgM were assessed through ELISA and patients were stratified based on the presence of other aPL, on their clinical and laboratory features at time of blood sampling and on their clinical history. Synthetic indices of disease activity, chronic damage and cardiovascular risk were calculated at time of venipuncture.Results: Fifty-one (38.9%) patients with SLE had aPS/PT and 15 (11.5%) patients had aPS/PT as the only aPL (aPS/PT-only). aPS/PT-only patients had a significantly higher prevalence of NPSLE than quadruple aPL-negative patients (p?=?.007). Patients with aPS/PT were more likely to have a history of ischaemia, thrombocytopenia and Libman–Sacks’ endocarditis. The presence of aPS/PT also associated with previous accrual of at least one damage item (p?=?.043), but had limited predictive values for damage progression in the short term.Conclusion: aPS/PT antibodies provide non-redundant information that could contribute to risk assessment and stratification of patients with SLE. 相似文献
50.
Lucia MB Rutella S Leone G Larocca LM Vella S Cauda R 《Journal of acquired immune deficiency syndromes (1999)》2002,30(4):369-378
P-glycoprotein (P-gp) transports a wide range of structurally unrelated drugs, such as HIV protease inhibitors (PIs) and cytotoxic compounds such as anthracyclines. Because modification of P-gp phenotype and function is an important underlying mechanism of drug interactions, the current study was conducted in order to evaluate whether highly active antiretroviral therapy (HAART), HIV plasma viral load (VL), or cancer chemotherapy may induce in vivo changes of P-gp phenotype in peripheral blood mononuclear cells (PBMCs) from HIV-infected treatment-naive and -experienced subjects at different stages of HIV infection and/or disease, including patients with HIV-associated Kaposi sarcoma (KS). Our results show that neither HAART nor HIV VL, nor the stage of HIV infection and/or disease, significantly alter P-gp expression on PBMCs. In particular, surface P-gp expression is expressed at low levels by T-cell subsets, B cells, and NK cells, whereas almost all monocytes are double positive and these results are not modified by HIV PI-containing regimens. By contrast, a significant phenotype modification is detected in PBMCs from AIDS/KS patients after challenge with the liposomal formulation of the anthracycline doxorubicin (L-DOX) with the higher expression reached 24 hours after the end of the drug infusion. In addition, accumulation of L-DOX is unaffected by P-gp-mediated drug efflux as documented by in vitro experiments, in sharp contrast to the kinetic of free DOX, based on HIV PI blockade experiments. Finally, P-gp expression was found in KS spindle cells from HIV-infected treatment-naive AIDS/KS patients. We conclude that P-gp phenotype in PBMCs and specific subsets is not altered by HAART and/or HIV, whereas a significant increase is induced by specific anticancer drugs such as L-DOX. Moreover, HIV PIs possess an inhibitory effect on P-gp function that may improve DOX sensitivity in KS spindle cells. 相似文献