全文获取类型
收费全文 | 1109篇 |
免费 | 91篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 37篇 |
妇产科学 | 17篇 |
基础医学 | 105篇 |
口腔科学 | 26篇 |
临床医学 | 199篇 |
内科学 | 140篇 |
皮肤病学 | 9篇 |
神经病学 | 225篇 |
特种医学 | 33篇 |
外科学 | 56篇 |
综合类 | 16篇 |
一般理论 | 3篇 |
预防医学 | 187篇 |
眼科学 | 21篇 |
药学 | 93篇 |
肿瘤学 | 37篇 |
出版年
2022年 | 7篇 |
2021年 | 20篇 |
2020年 | 8篇 |
2019年 | 9篇 |
2018年 | 22篇 |
2017年 | 14篇 |
2016年 | 16篇 |
2015年 | 24篇 |
2014年 | 41篇 |
2013年 | 54篇 |
2012年 | 73篇 |
2011年 | 76篇 |
2010年 | 34篇 |
2009年 | 24篇 |
2008年 | 51篇 |
2007年 | 62篇 |
2006年 | 39篇 |
2005年 | 48篇 |
2004年 | 47篇 |
2003年 | 52篇 |
2002年 | 48篇 |
2001年 | 42篇 |
2000年 | 34篇 |
1999年 | 20篇 |
1998年 | 13篇 |
1997年 | 8篇 |
1996年 | 13篇 |
1995年 | 8篇 |
1994年 | 9篇 |
1993年 | 13篇 |
1992年 | 16篇 |
1991年 | 27篇 |
1990年 | 25篇 |
1989年 | 20篇 |
1988年 | 17篇 |
1987年 | 17篇 |
1986年 | 20篇 |
1985年 | 14篇 |
1983年 | 10篇 |
1982年 | 7篇 |
1981年 | 7篇 |
1980年 | 5篇 |
1979年 | 13篇 |
1978年 | 8篇 |
1976年 | 7篇 |
1974年 | 9篇 |
1972年 | 9篇 |
1971年 | 5篇 |
1968年 | 4篇 |
1966年 | 4篇 |
排序方式: 共有1207条查询结果,搜索用时 203 毫秒
21.
Lipsett PA Swoboda SM Dickerson J Ylitalo M Gordon T Breslow M Campbell K Dorman T Pronovost P Rosenfeld B 《Annals of surgery》2000,231(2):262-268
OBJECTIVE: To examine the functional outcome and costs of a prolonged illness requiring a stay in the surgical intensive care unit (SICU) of 7 of more days. SUMMARY BACKGROUND DATA: The long-term benefits and costs after a prolonged SICU stay have not been well studied. METHODS: All patients with an SICU length of stay of 7 or more days from July 1, 1996, to June 30, 1997, were enrolled. One hundred twenty-eight patients met the entry criteria, and mortality status was known in 127. Functional outcome was determined at baseline and at 1, 3, 6, and 12 months using the Sickness Impact Profile score, which ranges from 0 to 100, with a score of 30 being severely disabled. Hospital costs for the index admission and for all readmissions to Johns Hopkins Hospital were obtained. All data are reported as median values. RESULTS: For the index admission, age was 57 and APACHE II score was 23. The initial length of stay in the ICU was 11 days; the hospital length of stay was 31 days. The Sickness Impact Profile score was 20.2 at baseline, 42.9 at 1 month, 36.2 at 3 months, and 20.3 at 6 months, and was lower than baseline at 1 year. The actual 1-year survival rate was 45.3%. The index admission median cost was $85,806, with 65 total subsequent admissions to this facility. The cost for a single 1-year survivor was $282,618 (1996). CONCLUSIONS: An acute surgical illness that results in a prolonged SICU stay has a substantial in-hospital death rate and is costly, but the functional outcome from both a physical and physiologic standpoint is compatible with a good quality of life. 相似文献
22.
This paper offers occupational therapy generalists and specialists a new framework by which to consider clinical evaluation data and an older adult's driving risk and potential to resume this previously learned skill. Based on Michon's model describing the hierarchy of driving levels, clinical questions identify the factors that may affect a client's fitness to drive. The first part is intended to support clinical judgment of whether a client needs a driving evaluation by a driver rehabilitation specialist. The second part offers a framework to organize clinical data that are already known and determine what other evaluation information is justified and necessary to make a driving recommendation. Methods and rational for use are discussed. 相似文献
23.
C. Duncan K. Savage M. Williams B. Dickerson A. V. Kondas K. A. Fitzpatrick J. L. Guerrero T. Spraker G. J. Kersh 《Transboundary and Emerging Diseases》2013,60(4):345-350
In 2010, Coxiella burnetii was identified at a high prevalence in the placentas of Northern fur seals (Callorhinus ursinus) collected at a single rookery on St. Paul Island Alaska; an area of the United States where the agent was not known to be present. As contamination was hypothesized as a potential cause of false positives, but nothing was known about environmental C. burnetii in the region, an environmental survey was conducted to look for the prevalence and distribution of the organism on the island. While environmental prevalence was low, two strains of the organism were identified using PCR targeting the COM1 and IS1111 genes. The two strains are consistent with the organism that has been increasingly identified in marine mammals as well as a strain type more commonly found in terrestrial environments and associated with disease in humans and terrestrial animals. Further work is needed to elucidate information regarding the ecology of this organism in this region, particularly in association with the coastal environment. 相似文献
24.
25.
Domoto-Reilly K Sapolsky D Brickhouse M Dickerson BC;for the Alzheimer's Disease Neuroimaging Initiative 《NeuroImage》2012,63(1):348-355
There is considerable debate about the neuroanatomic localization of semantic memory, the knowledge of culturally shared elements such as objects, concepts, and people. Two recent meta-analyses of functional imaging studies (fMRI and PET) sought to identify cortical regions involved in semantic processing. Binder and colleagues (Binder et al., 2009) identified several regions of interest, widely distributed throughout the frontal, parietal, and temporal cortices. In contrast, Lambon Ralph and colleagues (2010) focused on the anterior temporal lobe, and found that when the potential for signal loss is accounted for (due, for example, to distortion artifact or field of view restriction), significant regional activation is detected. We set out to determine whether the anterior temporal lobe plays a significant role in picture naming, a task which relies on semantic memory. We examined a relatively large sample of patients with early Alzheimer's disease (N=145), a multifocal disease process typically characterized in the early stages by problems with episodic memory and executive function. Hypothesis-driven analyses based on regions of interest derived from the meta-analyses as well as exploratory analyses across the entire cerebral cortex demonstrated a highly specific correlation between cortical thinning of the left anterior temporal lobe and impaired naming performance. These findings lend further support to theories that include a prominent role for the anterior temporal lobe in tasks that rely on semantic memory. 相似文献
26.
27.
Initiation of the extrinsic pathway of coagulation by human and rabbit alveolar macrophages: a kinetic study 总被引:3,自引:0,他引:3
We examined assembly and expression of the factor X activating complex on human and rabbit alveolar macrophages. Kinetic parameters of the factor X activating reaction were determined by functional titrations of factors VII and X with macrophage tissue factor (TF) added. We found rapid activation of factor X to Xa on alveolar macrophage surfaces. Detection of rapid factor Xa formation on macrophages required addition of exogenous factors VII and X. At plasma concentrations of the purified factors, factor Xa was formed on freshly isolated macrophages at approximately 5.4 pmol/min/10(6) cells. After macrophage maturation in culture for 20 hours with LPS (endotoxin) added, the factor X activation rate was increased two- to sixfold. The km' (apparent km) of TF-factor VII enzymatic complexes assembled on alveolar macrophages for factor X were (258 +/- 55 and 475 +/- 264 nmol/L for human and rabbit cells, respectively). The km' did not change during macrophage maturation in culture, but V'max (apparent Vmax) was consistently increased. The K1/2 of human factor VII (concentrations giving half maximal rates of factor X activation) for the interaction with human and rabbit alveolar macrophage TF were 0.191 +/- 0.096 and 1.7 +/- 0.7 etamol/L, respectively. The K1/2 were not significantly changed after maturation, whereas rates of Xa formation at saturation with factor VII were increased. The fast rates of factor X activation observed at physiologic concentrations of plasma-derived factors VII and X indicate that TF on alveolar macrophages is likely to provide sites for binding of factor VII and activation of factor X in vivo during clotting reactions associated with alveolar edema and inflammation. 相似文献
28.
Huijin Dong Johanna R. Mora Catherine Brockus Shannon D. Chilewski Robert Dodge Colin Merrifield W. Matthew Dickerson Binodh DeSilva 《The AAPS journal》2015,17(6):1511-1516
Immunogenicity testing for PEGylated biotherapeutics should include methods to detect both anti-protein and anti-PEG antibodies (anti-PEG). Although some methods have been published for the detection of anti-PEG antibodies, the information is incomplete and, in some cases, reagents used (such as Tween-20) are known to interfere with detection. This rapid communication describes the use of BioScale’s Acoustic Membrane MicroParticle (AMMP®) technology using the ViBE® Workstation to measure anti-PEG antibodies in human serum samples. Briefly, a sample spiked with monoclonal human IgG anti-PEG antibody is diluted in buffer and incubated with paramagnetic beads coated with linear chain mPEG to capture anti-PEG antibodies. The complex is then captured on an acoustic membrane coated with Protein A. The change in mass on the membrane caused by the binding of the complex to the membrane results in a signal proportional to the mass of anti-PEG antibodies. The data indicate that an assay with a sensitivity of less than 1000 ng/mL for IgG is achievable. This level of sensitivity is better than current published reports on IgG anti-PEG antibody detection.KEY WORDS: acoustic membrane microparticle technology, anti-peg antibodies, emerging technology, immunogenicity assays, pegylated biotherapeutics 相似文献
29.
Day GA Hoover MD Stefaniak AB Dickerson RM Peterson EJ Esmen NA Scripsick RC 《Experimental lung research》2005,31(3):341-360
Beryllium metal and its oxide and alloys are materials of industrial significance with recognized adverse effects on worker health. Currently, the degree of risk associated with exposure to these materials in the workplace is assessed through measurement of beryllium aerosol mass concentration. Compliance with the current mass-based occupational exposure limit has proven ineffective at eliminating the occurrence of chronic beryllium disease (CBD). The rationale for this research was to examine the mechanism of beryllium bioavailability, which may be pertinent to risk. The authors tested the hypothesis in vitro that dissolution of particles engulfed by macrophages is greater than dissolution in cellular medium alone. Physicochemical changes were evaluated in vitro for well-characterized high-purity beryllium oxide (BeO) particles in cell-free media alone and engulfed by and retained within murine J774A.1 monocyte-macrophage cells. The BeO particles were from a commercially available powder and consisted of diffuse clusters (aerodynamic diameter range 1.5 to 2.5 microm) of 200-nm diameter primary particles. Following incubation for 124 to 144 hours, particles were recovered and recharacterized. Recovered particles were similar in morphology, chemical composition, and size relative to the original material, confirming the relatively insoluble nature of the BeO particles. Measurable levels of dissolved beryllium, representing 0.3% to 4.8% of the estimated total beryllium mass added, were measured in the recovered intracellular fluid. Dissolved beryllium was not detected in the extracellular media. The BeO chemical dissolution rate constant in the J774A. 1 cells was 2.1 +/- 1.7 x 10(-8)g/(cm2 . day). In contrast, the BeO chemical dissolution rate constant in cell-free media was < 8.1 x 10(-9)g/(cm2 . day). In vivo, beryllium dissolved by macrophages may be released in the pulmonary alveolar environment, in the lymphatic system after transport of beryllium by macrophages, or in the alveolar interstitium after migration and dissolution of beryllium particles in tissue. These findings demonstrate a mechanism of bioavailability for beryllium, are consistent with previously observed results in canine alveolar macrophages, and provide insights into additional research needs to understand and prevent beryllium sensitization and CBD. 相似文献
30.
Douglas M. Simon John P. Cello Jorge Valenzuela Richard Levy Gordon Dickerson Richard Goodgame Michael Brown Kip Lyche W.Jeffrey Fessel James Grendell C.Mel Wilcox Nezam Afdhal Ronald Fogel Vonda Reeves-Darby John Stern Owen Smith Frank Graziano Douglas Pleakow Timothy Flanigan Timothy Schubert Mark Loveless Larry Eron Paul Basuk Maurizio Bonacini Jan Orenstein 《Gastroenterology》1995,108(6):1753-1760
Diarrhea is a significant problem in patients with acquired immunodeficiency syndrome (AIDS). The aim of this study was to determine octreotide effectiveness in refractory AIDS-associated diarrhea. In a 3-week protocol, 129 patients with a stool weight of >500 g/day despite standard antidiarrheal therapy were randomized to receive octreotide or placebo (3:2 ratio). Octreotide dose was increased 100 μg weekly to a maximum of 300 μg three times a day based on weekly 72-hour stool collections. Subsequently, patients received open-label octreotide at doses of up to 500 μg three times a day. A 30% decrease in stool weight defined response. After 3 weeks, 48% of octreotide- and 39% of placebo-treated patients had responded (P = 0.43). At 300 μg three times a day, 50% of octreotide- and 30.1% of placebo-treated patients responded (P = 0.12). At a baseline stool weight of 1000–2000 g/day, 57% of octreotide- and 25% of placebo-treated patients responded (P = 0.06). Response rates based on CD4 counts, diarrhea duration, body weight, human immunodeficiency virus risk factor, and presence or absence of pathogens showed no benefit of octreotide. Adverse events were more frequent in the octreotide-treated group. In the doses studied, octreotide was not more effective than placebo in patients with refractory AIDS-associated diarrhea. This lack of effectiveness may be attributable to inadequate sample size, doses, and duration of study treatment. 相似文献