全文获取类型
收费全文 | 4715篇 |
免费 | 379篇 |
国内免费 | 32篇 |
专业分类
耳鼻咽喉 | 32篇 |
儿科学 | 153篇 |
妇产科学 | 183篇 |
基础医学 | 630篇 |
口腔科学 | 231篇 |
临床医学 | 503篇 |
内科学 | 951篇 |
皮肤病学 | 193篇 |
神经病学 | 330篇 |
特种医学 | 112篇 |
外科学 | 485篇 |
综合类 | 75篇 |
一般理论 | 7篇 |
预防医学 | 401篇 |
眼科学 | 83篇 |
药学 | 379篇 |
中国医学 | 48篇 |
肿瘤学 | 330篇 |
出版年
2024年 | 10篇 |
2023年 | 111篇 |
2022年 | 212篇 |
2021年 | 345篇 |
2020年 | 226篇 |
2019年 | 318篇 |
2018年 | 360篇 |
2017年 | 234篇 |
2016年 | 230篇 |
2015年 | 231篇 |
2014年 | 288篇 |
2013年 | 325篇 |
2012年 | 467篇 |
2011年 | 430篇 |
2010年 | 196篇 |
2009年 | 153篇 |
2008年 | 202篇 |
2007年 | 177篇 |
2006年 | 152篇 |
2005年 | 109篇 |
2004年 | 85篇 |
2003年 | 59篇 |
2002年 | 63篇 |
2001年 | 8篇 |
2000年 | 4篇 |
1999年 | 15篇 |
1998年 | 7篇 |
1997年 | 6篇 |
1995年 | 4篇 |
1993年 | 4篇 |
1992年 | 2篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1989年 | 5篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1984年 | 2篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 4篇 |
1976年 | 5篇 |
1975年 | 2篇 |
1974年 | 12篇 |
1973年 | 8篇 |
1972年 | 7篇 |
1971年 | 5篇 |
1970年 | 7篇 |
1969年 | 3篇 |
1968年 | 3篇 |
排序方式: 共有5126条查询结果,搜索用时 15 毫秒
1.
2.
Among many conventional techniques, nuclear techniques have shown to be faster, more reliable, and more effective in detecting explosives. In the present work, neutrons from a 5 Ci Am-Be neutron source being in water tank are captured by elements of soil and landmine (TNT), namely (14)N, H, C, and O. The prompt capture gamma-ray spectrum taken by a NaI (Tl) scintillation detector indicates the characteristic photo peaks of the elements in soil and landmine. In the high-energy region of the gamma-ray spectrum, besides 10.829 MeV of (15)N, single escape (SE) and double escape (DE) peaks are unmistakable photo peaks, which make the detection of concealed explosive possible. The soil has the property of moderating neutrons as well as diffusing the thermal neutron flux. Among many elements in soil, silicon is more abundant and (29)Si emits 10.607 MeV prompt capture gamma-ray, which makes 10.829 MeV detection difficult. The Monte Carlo simulation was used to adjust source-target-detector distances and soil moisture content to yield the best result. Therefore, we applied MCNP4C for configuration very close to reality of a hidden landmine in soil. 相似文献
3.
This retrospective analysis reviews the clinical experience of a major urban referral hospital with diffuse malignant pleural mesothelioma during the 14-year period from 1973 through 1986. Seventy-five cases of definite or equivocal mesothelioma were identified. There were four cases of primary malignant peritoneal mesothelioma, seven cases of benign fibrous mesothelioma, and 64 cases of diffuse malignant pleural mesothelioma. In 43 cases (67%) of diffuse malignant pleural mesothelioma, there was historic evidence of asbestos exposure. In 21 cases (33%), there was no known history of asbestos exposure. An increase in annual incidence of diffuse malignant pleural mesothelioma was observed over the study period, from three cases in 1973 to ten cases in 1986. Despite greater awareness of this disease, the diagnosis remains a difficult one to establish given the nonspecific symptoms, signs and radiographic appearance, variable histologic appearance, and poor diagnostic sensitivity and specificity of thoracentesis and closed pleural biopsy. Thoracotomy, thoracoscopy, and CT-guided needle biopsies gave higher yields and are the diagnostic measures of choice when diffuse malignant pleural mesothelioma is suspected. 相似文献
4.
T-cell receptor α-chain cDNA were generated from unstimulated peripheral blood mononuclear cells of a DR2,3,52a individual using a modified anchor PCR method. Fifty-six cDNA clones were identified representing 47 distinct T-cell receptor clonotypes and 26 VA loci. This analysis identified a new VA gene family VA30, and aew member of the VA6 gene family. 相似文献
5.
This study introduces a new procedure to prepare alginate-chitosan nanoparticles and examines several experimental parameters in relation to their formation and characteristics. Using DLS and TEM analysis, nanoparticle formation was shown to be predominantly affected by the ratio of alginate to chitosan, the molecular weight of the biopolymers and the solution pH. We report a method that results in spherical particles with mean diameters ranging from 323 nm to 1.6 microm, depending on the preparation conditions. The smallest particles were formed using lower molecular weight polymers with pH between 5.0 and 5.6 and having an alginate/chitosan weight ratio of 1:1.5. We have shown that DNA can be loaded with 60% association efficiency. Our system demonstrates suitable size, loading and release characteristics for application in drug- and gene-delivery systems. 相似文献
6.
Recurrent Bacteremia Caused by a “Flexispira”-Like Organism in a Patient with X-Linked (Bruton’s) Agammaglobulinemia
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)
Susan Weir Brenda Cuccherini Anne M. Whitney Marsha L. Ray John P. MacGregor Arnold Steigerwalt Maryam I. Daneshvar Robbin Weyant Betty Wray John Steele Warren Strober Vee J. Gill 《Journal of clinical microbiology》1999,37(8):2439-2445
Helicobacter spp., except for Helicobacter cinaedi, have only rarely been reported in cases of septicemia. A patient with X-linked (Bruton's) agammaglobulinemia was found to have persistent sepsis with a Helicobacter-like organism despite multiple courses of antibiotics. His periods of sepsis were associated with leg swelling thought to be consistent with cellulitis. The organism was fastidious and required a microaerophilic environment containing H(2) for growth. Optimal growth was observed at 35 to 37 degrees C on sheep blood, CDC anaerobe, and Bordet-Gengou agars. Serial subcultures every 4 to 5 days were required to maintain viability. The organism was strongly urease positive and showed highest relatedness to Helicobacter-like organisms with the vernacular name "Flexispira rappini" by 16S rRNA gene sequence analysis. Genomic DNA hybridization studies, however, found 24 to 37% relatedness to "F. rappini" and even less to other Helicobacter spp. Although the organism phenotypically resembles "Flexispira" and Helicobacter, it is thought to represent a new taxon. The patient's infection was eventually cleared with a prolonged (5-month) course of intravenous imipenem and gentamicin. 相似文献
7.
Selective elimination of alloreactive donor T cells attenuates graft-versus-host disease and enhances T-cell reconstitution. 总被引:5,自引:0,他引:5
Maria Gendelman Maryam Yassai Elizabeth Tivol Ashley Krueger Jack Gorski William R Drobyski 《Biology of blood and marrow transplantation》2003,9(12):742-752
Impaired T-cell immune reconstitution is a major complication after allogeneic bone marrow transplantation (BMT) and is particularly exacerbated in the setting of graft-versus-host disease (GVHD). Conventional approaches to reduce GVHD, such as T-cell depletion or pharmacologic immunosuppression, typically fail to enhance T-cell immunity and often further exacerbate this problem. An alternative strategy to mitigate GVHD severity is the selective elimination of graft-versus-host-reactive donor T cells by using an incorporated thymidine kinase suicide gene. This approach has been shown to effectively reduce GVHD, although the effect of this strategy on T-cell reconstitution is unresolved. We addressed this question in a murine BMT model (C57BL/6 [H-2(b)] --> AKR/J [H-2(k)]) in which donor and recipient differ at major and minor histocompatibility antigens. Lethally irradiated AKR recipients transplanted with T cell-depleted bone marrow plus thymidine kinase-positive T cells followed by post-BMT ganciclovir (GCV) administration had more prompt and complete normalization of the T-cell repertoire than phosphate-buffered saline-treated GVHD control animals. By 60 days after transplantation, mice administered GCV had T-cell repertoires that were virtually indistinguishable from those of mice that underwent transplantation with T cell-depleted bone marrow alone (no GVHD controls) when assayed by T-cell receptor (TCR) spectratyping. In contrast, phosphate-buffered saline-treated animals had persistent skewing in most Vbeta families. T cells obtained from GCV-treated mice also had significantly higher in vitro proliferative responses after posttransplantation inoculation with ovalbumin than GVHD animals, indicating that CD4(+) T-cell responses against a nominal antigen were better preserved in these chimeras. Finally, GCV-treated mice had augmented immune reconstitution in response to exogenous interleukin-7 administration, as evidenced by increased overall spleen cellularity and absolute numbers of T and B cells. This was in contrast to GVHD control animals, which had a blunted response to interleukin-7 administration. These data indicate that GVHD severity can be significantly reduced by selective elimination of alloreactive donor T cells without compromise of T-cell immunity. Moreover, in light of previous studies demonstrating that this strategy can reduce GVHD without loss of alloengraftment and antileukemia reactivity, further examination of this approach in humans seems warranted. 相似文献
8.
Mohammad Ali Boroumand Maryam Sotoudeh Anvari Namvar Movahedi Parin Yazdanifard 《Cardiovascular pathology》2008,17(2):124-125
Mesothelial/monocytic incidental cardiac excrescence (MICE) is a very uncommon lesion. Diagnosis is incidental and may simulate thrombotic lesions. One of the hypotheses with regard to the etiology of this lesion is a previous cardiac procedure especially mitral valve repair or commissurotomy. Herein, we describe a MICE incidentally found in a patient who underwent mitral valve replacement, as a thrombotic lesion on the left atrial auricle. Histopathologic examination suggested MICE lesions and immunohistochemical stains confirmed it. 相似文献
9.
Sympathetic skin response (SSR) in erythromelalgia 总被引:2,自引:0,他引:2
Kazemi B Shooshtari SM Nasab MR Roghani RS Haghighi FM 《Electromyography and clinical neurophysiology》2003,43(3):165-168
BACKGROUND: Erythromelalgia (EM) is characterized by severe pain associated with local redness and hotness in the extremities. When the extremity is lowered, or heat is applied, the pain is intensified and when coldness is applied, or the extremity is elevated the pain is decreased. OBJECTIVE: To evaluate if there is any sympathetic nervous system involvement in erythromelalgia, sympathetic skin response (SSR) test was done. SETTING: This study was conducted during the years 1998-2000 in the Department of Physical medicine and Rehabilitation, Shiraz University of Medical Sciences. METHODS: SSR study was done on 22 patients with erythromelalgia and 22 normal subjects were matched for age and sex for comparison. RESULTS: There is a significant difference between the patients and controls especially in the lower extremity findings (P = 0.000). More than 72.7% of the patients had abnormal SSR. CONCLUSION: It is concluded that sympathetic peripheral fibers (C fibers) are involved in erythromelalgia and it is probably the pathogenesis of the disease. 相似文献
10.
Correlation between Karnofsky Performance Status Scale and Short-Form Health Survey in patients on maintenance hemodialysis 总被引:1,自引:0,他引:1
Arogundade FA Zayed B Daba M Barsoum RS 《Journal of the National Medical Association》2004,96(12):1661-1667
BACKGROUND: Assessment of quality of life is vital inmonitoring response to various treatment measures. Various instruments, which include both generic and disease-specific instruments, are used in the assessment of health-related quality of life (HRQOL). In this study, we compare two commonly used generic instruments. OBJECTIVES: The objective of this study was to compare two generic instruments, the Karnofsky Performance Status Scale and the SF-36 Health Survey in hemodialysis (HD) patients. The study also aims to find out the association (if any) between HRQOL scores using these two scales and various clinical and biochemical parameters. MATERIALS AND METHODS: Sixty-two maintenance HD patients were recruited after informed consents were obtained. Detailed sociodemographic data was obtained. They were assessed during their regular HD sessions. Serum chemistry (which included serum urea, creatinine, Na+, K+, HCO3-, Ca2+, Po4(2-)), albumin, globulin, total protein and hemoglobin (g/dl) were assessed in all the patients. Adequacy of HD was assessed using second-generation Daugirdais formula. HRQOL was assessed using the Karnofsky and SSF-36 instruments and the scores collated and compared. Data was analyzed using SPSS version 10. RESULTS: Fifty-five patients completed the study (27 males and 28 females, mean age 40.76 +/- 11.05 years and age range of 20-65 years). There was a significant positive correlation between Karnofsky scores and all eight SF-36 domains, but only physical functioning, social functioning and role limitation due to emotional problems maintained the significance on multiple regression analysis. The serum creatinine and hemoglobin postively correlated with physical function, bodily pain, social functioning and Karnofsky scores. Age of the patients correlated negatively with two SF-36 dimensions (physical functioning and role limitation due to physical fitness) and Karnofsky scores. CONCLUSION: This study revealed a good correlation between Karnofsky performance status scale and the short-form (SF36) health survey in this Egyptian population. Age, serum creatinine and hemoglobin significantly influence quality of life in this HD patient population. 相似文献