全文获取类型
收费全文 | 9174篇 |
免费 | 810篇 |
国内免费 | 27篇 |
学科分类
医药卫生 | 10011篇 |
出版年
2021年 | 131篇 |
2020年 | 97篇 |
2019年 | 144篇 |
2018年 | 156篇 |
2017年 | 120篇 |
2016年 | 134篇 |
2015年 | 136篇 |
2014年 | 187篇 |
2013年 | 302篇 |
2012年 | 436篇 |
2011年 | 401篇 |
2010年 | 279篇 |
2009年 | 216篇 |
2008年 | 421篇 |
2007年 | 384篇 |
2006年 | 382篇 |
2005年 | 375篇 |
2004年 | 339篇 |
2003年 | 353篇 |
2002年 | 327篇 |
2001年 | 286篇 |
2000年 | 280篇 |
1999年 | 243篇 |
1998年 | 127篇 |
1997年 | 113篇 |
1996年 | 88篇 |
1995年 | 107篇 |
1994年 | 91篇 |
1993年 | 84篇 |
1992年 | 189篇 |
1991年 | 217篇 |
1990年 | 163篇 |
1989年 | 206篇 |
1988年 | 216篇 |
1987年 | 257篇 |
1986年 | 206篇 |
1985年 | 235篇 |
1984年 | 139篇 |
1983年 | 96篇 |
1982年 | 77篇 |
1981年 | 85篇 |
1980年 | 71篇 |
1979年 | 107篇 |
1978年 | 108篇 |
1977年 | 92篇 |
1976年 | 73篇 |
1975年 | 76篇 |
1974年 | 77篇 |
1973年 | 72篇 |
1972年 | 72篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Suchi Raghunathan Corey L. Reynolds Robert J. Schwartz M. David Stewart Bradley K. McConnell 《Fundamental & clinical pharmacology》2019,33(1):25-30
Inbred mouse strains are the most widely used mammalian model organism in biomedical research owing to ease of genetic manipulation and short lifespan; however, each inbred strain possesses a unique repertoire of deleterious homozygous alleles that can make a specific strain more susceptible to a particular disease. In the current study, we report dystrophic cardiac calcinosis (DCC) in C.B‐17 SCID male mice at 10 weeks of age with no significant change in cardiac function. Acquisition of DCC was characterized by myocardial injury, fibrosis, calcification, and necrosis of the tissue. At 10 weeks of age, 38% of the C.B‐17 SCID mice from two different commercial colonies exhibited significant calcinosis on the ventricular epicardium, predominantly on the right ventricle. The frequency of calcinosis was more than 50% for mice obtained from Taconic's Cambridge City colony and 25% for mice obtained from Taconic's German Town colony. Interestingly, the DCC phenotype did not affect cardiac function at 10 weeks of age. No differences in echocardiography or electrocardiography were observed between the calcinotic and non‐calcinotic mice from either colony. Our findings suggest that C.B‐17 SCID mice exhibit DCC as early as 10 weeks of age with no significant impact on cardiac function. This strain of mice should be cautiously considered for the study of cardiac physiology. 相似文献
3.
Ferdynand Hebal Elissa Port Catherine J. Hunter Bryan Malas Jared Green Marleta Reynolds 《Journal of pediatric surgery》2019,54(4):656-662
Background/purpose
Computed tomography (CT) derived Haller Index (HI) remains the standard for quantifying severity in patient with pectus excavatum (PE). Optical scanning described in literature reports optimistic results and new indices that correlate with HI. This study assessed the feasibility of a handheld White Light Scanner (WLS) to obtain 3D measurements and indices of PE deformity.Methods
From April 2015–April 2017, WLS scanning was conducted by orthotists during clinical visits. Included were children with PE up to 18?years. Analysis assessed correlation of a WLS-derived severity index, Hebal-Malas Index (HMI), with physician measured PE Depth (PED), and CT-derived HI.Results
Of 195 participants, 185(94%) patients with PE were scanned and 127(69%) had complete WLS data. For 88 patients undergoing monitoring, HMI correlated with PED (r?=?0.42, p?=?0.004). For 39 patients with pre-operative CT, HMI demonstrated strong correlation with HI (r?=?0.87, p < 0.0001).Conclusions
WLS demonstrated high feasibility of scanning PE. WLS-derived HMI best correlates with HI for patients with severe pectus deformity. Our current data is suggestive that WLS is best applied for severe deformities and yet to be established for milder deformities. Future yearly WLS will provide data on deformity progression and surgical therapy.Level of Evidence
IV.Type of Study
Diagnostic Study. 相似文献4.
5.
Dwight W. Reynolds M.D. F.H.R.S. 《Pacing and clinical electrophysiology : PACE》2006,29(10):1186-1186
6.
7.
8.
Myocyte cytochrome oxidase activity and neuromuscular conduction associated with metabolic alkalemia
Many studies have shown increased affinity of hemoglobin for oxygen during metabolic alkalemia and dependence of intramitochondrial cytochrome oxidase activity on arterial oxyhemoglobin saturation. The present studies tested the hypothesis that metabolic alkalemia produces tissue hypoxia independent of arterial oxygen desaturation. Neuromuscular conduction latency was used as an indicator of functional impairment, and was measured following electrostimulation of the sciatic nerve and recording of the electromyogram from the gastrocnemius muscle of rats anesthetized with pentobarbital sodium. To increase the affinity of hemoglobin for oxygen, sodium bicarbonate was administered in graded doses every 15 min. Statistical significance of changes was estimated by the paired Student's t test. Arterial bicarbonate ion concentration increased from 25 +/- 1.3 to 39.0 +/- 3.0 mM while arterial pH increased from 7.30 +/- 0.02 to 7.50 +/- 0.03 (P less than 0.01). Neuromuscular conduction latency increased from 1.9 +/- 0.13 to 2.7 +/- 0.18 ms (P less than 0.01). Tissue hypoxia was suggested by a greater decrease in mass spectrometric determinations of gastrocnemius muscle oxygen tension (PO2) in separate groups of control (arterial pH 7.38 +/- 0.04) and experimental (arterial pH 7.48 +/- 0.03) rats. These changes were accompanied by markedly decreased uptake of 3.3'-diaminobenzidine (DAB) by gastrocnemius muscle mitochondria, suggesting decreased intracellular activity of cytochrome oxidase and intracellular oxygen availability to myocytes in the absence of arterial oxygen desaturation. 相似文献
9.
10.
Sodium MRI of the human kidney at 3 Tesla. 总被引:6,自引:0,他引:6
Nimrod Maril Yael Rosen Glenn H Reynolds Alex Ivanishev Long Ngo Robert E Lenkinski 《Magnetic resonance in medicine》2006,56(6):1229-1234
The sodium concentration gradient in the kidney (from the cortex to the medulla) serves to regulate fluid homeostasis and is tightly coupled to renal function. It was previously shown that renal function and pathophysiology can be characterized in rat kidneys by measuring the sodium gradient with (23)Na MRI. This study demonstrates for the first time the ability of (23)Na MRI to map the distribution of sodium in the human kidney and to quantify the corticomedullary sodium gradient. The study was performed on a 3T Signa LX scanner (GE) using an in-house-built quadrature surface coil. (23)Na images of volunteers were acquired using a 3D coronal gradient-echo sequence at a spatial resolution of 0.3 x 0.3 x 1.5 cm(3) in a 25-min scan time. The signal intensity (relative to the noise) increased linearly from the cortex to each of the medullae with a mean slope of 1.6 +/- 0.2 in relative arbitrary units per mm (Rel.u./mm, N = 6) and then decreased, as expected, toward the renal pelvis. Water deprivation (12 hr) induced a significant increase of 25% (P < 0.05) in this gradient. Based on these results, we suggest that sodium MRI can serve as a valuable noninvasive method for functional imaging of the human kidney. 相似文献