全文获取类型
收费全文 | 641篇 |
免费 | 45篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 18篇 |
儿科学 | 18篇 |
妇产科学 | 15篇 |
基础医学 | 116篇 |
口腔科学 | 6篇 |
临床医学 | 82篇 |
内科学 | 101篇 |
皮肤病学 | 6篇 |
神经病学 | 53篇 |
特种医学 | 25篇 |
外科学 | 72篇 |
综合类 | 14篇 |
预防医学 | 75篇 |
眼科学 | 22篇 |
药学 | 28篇 |
中国医学 | 5篇 |
肿瘤学 | 37篇 |
出版年
2024年 | 2篇 |
2023年 | 2篇 |
2022年 | 8篇 |
2021年 | 27篇 |
2020年 | 17篇 |
2019年 | 23篇 |
2018年 | 26篇 |
2017年 | 7篇 |
2016年 | 17篇 |
2015年 | 15篇 |
2014年 | 24篇 |
2013年 | 39篇 |
2012年 | 44篇 |
2011年 | 41篇 |
2010年 | 30篇 |
2009年 | 36篇 |
2008年 | 40篇 |
2007年 | 47篇 |
2006年 | 37篇 |
2005年 | 49篇 |
2004年 | 39篇 |
2003年 | 40篇 |
2002年 | 41篇 |
2001年 | 6篇 |
2000年 | 2篇 |
1999年 | 4篇 |
1998年 | 8篇 |
1997年 | 8篇 |
1996年 | 5篇 |
1994年 | 1篇 |
1990年 | 1篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1983年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有693条查询结果,搜索用时 0 毫秒
31.
BACKGROUND: We identified risk factors and clinical outcomes associated with ambulatory care-sensitive conditions requiring intensive care unit (ICU) admission. METHODS: This prospective cohort study included 4,144 patients admitted to the medical ICU of an urban teaching hospital during a 3-year period. RESULTS: A total of 627 patients were classified as having ambulatory care-sensitive conditions (ie, potentially preventable ICU admissions). Black race, decreasing Acute Physiology and Chronic Health Evaluation II (APACHE II) score, younger age, female sex, and absence of immunodeficiency were independently associated with ambulatory care-sensitive conditions. Patients classified as having ambulatory care-sensitive conditions accounted for 2,006 ventilator days, 2,508 ICU days, and 5,392 hospital days. The hospital mortality rate was statistically lower for patients with ambulatory care-sensitive conditions than for patients without these conditions. Patients classified as having ambulatory care-sensitive conditions were also statistically more likely than other patients to lack health insurance and to sign out of the hospital against medical advice. CONCLUSION: Patients with ambulatory care-sensitive conditions account for a substantial portion of all admissions to the intensive care unit. These data suggest that interventions aimed at preventing such admissions could improve ICU bed use. 相似文献
32.
Advances in technology must be integrated into curricula. The authors review the process and risks associated with adopting handheld technology and offer suggestions for integrating this technology into nursing curricula. 相似文献
33.
Xu J Rao JR Millar BC Elborn JS Evans J Barr JG Moore JE 《Journal of medical microbiology》2002,51(12):1117-1127
Mushroom worker's lung (MWL) is a hypersensitivity pneumonitis or allergic alveolitis caused by a type III IgG-mediated immunopathogenic inflammatory reaction in the host due to the inhalation of several thermophilic organisms, including Thermoactinomyces spp. It is difficult to distinguish phenotypically the eight species of this genus; therefore, this study sought to develop an improved molecular means of identifying Thermoactinomyces spp. associated with MWL by partial 16S rDNA PCR amplification and direct sequencing. Hypervariable regions within the 16S rRNA gene, which could be employed as signature sequences of the eight individual species, were identified and employed with highly conserved flanking primers to allow initial PCR amplification, before direct DNA sequencing of the 16S rDNA amplicons. A novel 24-mer 16S rDNA oligonucleotide upstream primer was designed from in silico alignments of all Thermoactinomyces spp. and was employed in combination with downstream (reverse) 16S rDNA primers. This permitted the successful identification of all four isolates associated with mushroom workers' lung. The method may be useful in the identification of Thermoactinomyces spp. associated with allergic alveolitis or pneumonitis associated with occupational exposure in agricultural and horticultural environments. 相似文献
34.
35.
36.
Leonard E. Grosso Brian T. Collins Cherie H. Dunphy Ricardo R. Ramos 《Diagnostic cytopathology》1998,19(1):66-69
The diagnosis of Hodgkin's disease by fine-needle aspiration (FNA) can be problematic. A case of Hodgkin's disease, lymphocyte depleted subtype, sampled by FNA biopsy is presented. We describe the cytomorphologic features present in this unusual subtype of Hodgkin's disease and discuss the differential diagnosis. Immunohistochemical and morphologic findings of a subsequent biopsy specimen supported the diagnosis. Although FNA is an increasingly used diagnostic modality to evaluate tumors including malignant lymphomas, Hodgkin's disease remains, as in this case, a difficult diagnosis by FNA. Diagn. Cytopathol. 1998;19:66–69. © 1998 Wiley-Liss, Inc. 相似文献
37.
Victoria L. Fields Ian T. Kracalik Christina Carthel Adriana Lopez Amy Schwartz Nathaniel M. Lewis Mackenzie Bray Carlene Claflin Kilee Jorgensen Ha Khong Walter Richards Ilene Risk Maureen Smithee Madison Clawson Lee Cherie Booth Tara Scribellito Jason Lowry Jessica Huynh Linda Davis Holly Birch Tiffany Tran Joseph Walker Alicia Fry Aron Hall Jodee Baker Eric Pevzner Angela C. Dunn Jacqueline E. Tate Hannah L. Kirking Tair Kiphibane Cuc H. Tran 《Emerging infectious diseases》2021,27(12):2999
Outcomes and costs of coronavirus disease (COVID-19) contact tracing are limited. During March–May 2020, we constructed transmission chains from 184 index cases and 1,499 contacts in Salt Lake County, Utah, USA, to assess outcomes and estimate staff time and salaries. We estimated 1,102 staff hours and $29,234 spent investigating index cases and contacts. Among contacts, 374 (25%) had COVID-19; secondary case detection rate was ≈31% among first-generation contacts, ≈16% among second- and third-generation contacts, and ≈12% among fourth-, fifth-, and sixth-generation contacts. At initial interview, 51% (187/370) of contacts were COVID-19–positive; 35% (98/277) became positive during 14-day quarantine. Median time from symptom onset to investigation was 7 days for index cases and 4 days for first-generation contacts. Contact tracing reduced the number of cases between contact generations and time between symptom onset and investigation but required substantial resources. Our findings can help jurisdictions allocate resources for contact tracing. 相似文献
38.
Ovenden SP Nielson JL Liptrot CH Willis RH Tapiolas DM Wright AD Motti CA 《Journal of natural products》2011,74(1):65-68
A new sesquiterpene benzoxazole, nakijinol B (3), its acetylated derivative, nakijinol B diacetate (6), and two new sesquiterpene quinones, smenospongines B (4) and C (5), were isolated from the methanol extract of the marine sponge Dactylospongia elegans. Also isolated were the known compounds dactyloquinone B and a 1:1 mixture of ilimaquinone and 5-epi-ilimaquinone. Their structures were determined on the basis of spectroscopic analyses and comparison with literature data. The isolated compounds were assessed for their cytotoxicity against a panel of human tumor cell lines (SF-268, H460, MCF-7, and HT-29) and a normal mammalian cell line (CHO-K1). All compounds were found to have activities in the range 1.8-46 μM and lacked selectivity for tumor versus normal cell lines. 相似文献
39.
Carpal tunnel syndrome grading system in rheumatoid arthritis 总被引:2,自引:0,他引:2
Junko Shinoda Hiroyuki Hashizume Cherie McCown Masuo Senda Keiichiro Nishida Takeshi Doi Hajime Inoue 《Journal of orthopaedic science》2002,7(2):188-193
The grading system of Hashizume and Hirooka for carpal tunnel syndrome (CTS) was modified to refine the system for surgical
treatment selection for specific subsets of CTS in patients with rheumatoid arthritis (RA). The grading system uses clinical
signs and symptoms of CTS, including pain indications, to identify surgical subsets of patients to facilitate treatment selection.
Retrospective analysis of the system included radiographic and electromyographic findings. Twenty-nine hands of 21 adult patients
with CTS in RA were graded in the current study. Eight hands with mild synovitis received conservative treatment only. Endoscopic
carpal tunnel release (ECTR), using Okutsu's universal subcutaneous endoscopic system with a clear cannula, was performed
in 11 hands with moderate synovitis. Open carpal tunnel release (OCTR) combined with flexor tenosynovectomy was performed
in 9 hands with severe synovitis. One more hand required OCTR after ECTR when malignant RA was diagnosed. Clinical results,
evaluated using Kelly's criteria, were: excellent in 19 hands, good in 5, fair in 4, and poor in the 1 patient with malignant
RA. Clinical symptoms of CTS improved in all but the latter patient. Although the sample size in the current study is small,
the results appear to warrant further study to determine the clinical utility of the grading system.
Received: April 2, 2001 / Accepted: November 1, 2001 相似文献
40.