全文获取类型
收费全文 | 841篇 |
免费 | 49篇 |
国内免费 | 18篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 17篇 |
妇产科学 | 24篇 |
基础医学 | 83篇 |
口腔科学 | 10篇 |
临床医学 | 102篇 |
内科学 | 197篇 |
皮肤病学 | 6篇 |
神经病学 | 50篇 |
特种医学 | 170篇 |
外科学 | 102篇 |
综合类 | 16篇 |
一般理论 | 3篇 |
预防医学 | 55篇 |
眼科学 | 9篇 |
药学 | 34篇 |
中国医学 | 4篇 |
肿瘤学 | 23篇 |
出版年
2022年 | 3篇 |
2021年 | 18篇 |
2020年 | 4篇 |
2019年 | 5篇 |
2018年 | 8篇 |
2017年 | 9篇 |
2016年 | 8篇 |
2015年 | 13篇 |
2014年 | 14篇 |
2013年 | 27篇 |
2012年 | 43篇 |
2011年 | 51篇 |
2010年 | 24篇 |
2009年 | 29篇 |
2008年 | 34篇 |
2007年 | 61篇 |
2006年 | 55篇 |
2005年 | 39篇 |
2004年 | 35篇 |
2003年 | 51篇 |
2002年 | 41篇 |
2001年 | 28篇 |
2000年 | 28篇 |
1999年 | 29篇 |
1998年 | 13篇 |
1997年 | 11篇 |
1996年 | 15篇 |
1995年 | 10篇 |
1994年 | 9篇 |
1993年 | 6篇 |
1992年 | 20篇 |
1991年 | 21篇 |
1990年 | 16篇 |
1989年 | 28篇 |
1988年 | 20篇 |
1987年 | 19篇 |
1986年 | 12篇 |
1985年 | 6篇 |
1984年 | 4篇 |
1983年 | 4篇 |
1982年 | 3篇 |
1981年 | 5篇 |
1980年 | 6篇 |
1978年 | 3篇 |
1977年 | 4篇 |
1975年 | 5篇 |
1973年 | 3篇 |
1972年 | 1篇 |
1967年 | 1篇 |
1961年 | 2篇 |
排序方式: 共有908条查询结果,搜索用时 0 毫秒
41.
Adrenocorticotropin-independent macronodular adrenal hyperplasia: an uncommon cause of primary adrenal hypercortisolism 总被引:5,自引:0,他引:5
Doppman JL Chrousos GP Papanicolaou DA Stratakis CA Alexander HR Nieman LK 《Radiology》2000,216(3):797-802
PURPOSE: To describe the imaging findings in the adrenal glands of 12 patients with adrenocorticotropin (ACTH)-independent macronodular adrenocortical hyperplasia (AIMAH). MATERIALS AND METHODS: Computed tomographic (CT) and magnetic resonance (MR) imaging findings in the adrenal glands were reviewed retrospectively in 12 patients (three men, nine women) with ACTH-independent Cushing syndrome and with bilateral nonpigmented multinodular adrenal hyperplasia. The results of pituitary MR imaging, adrenal scintigraphy, and petrosal sampling were available in nine, five, and six patients, respectively. Eleven patients underwent bilateral and one patient underwent unilateral adrenalectomy. RESULTS: Eleven patients had enlarged multinodular adrenal glands: Nodules were 0.1-5.5 cm. The combined weight of both adrenal specimens for the 11 bilateral adrenalectomy specimens was 28-297 g, with a mean weight of 122 g. Glands were hypointense compared with the liver on T1-weighted images and were hyperintense on T2-weighted images. Pituitary MR imaging findings were negative in nine of nine patients. Iodomethylnorcholesterol scintigraphy showed bilateral uptake in four of five patients. Petrosal sinus sampling revealed no petrosal-to-peripheral ACTH gradients before corticotropin-releasing hormone (CRH) stimulation in six of six patients, but three patients had gradients after CRH stimulation. After undergoing bilateral or unilateral adrenalectomy, all patients were cured. CONCLUSION: AIMAH is a rare cause of ACTH-independent Cushing syndrome, with characteristic CT findings of massively enlarged multinodular adrenal glands. Bilateral adrenalectomy is indicated on the basis of clinical and CT findings. 相似文献
42.
Utter AC Whitcomb DC Nieman DC Butterworth DE Vermillion SS 《Medicine and science in sports and exercise》2000,32(1):41-45
PURPOSE: Aerobic exercise may influence gallstone disease pathogenesis through its effect on gallbladder motility. The purpose of this investigation was to examine the effects of exercise training on gallbladder emptying in obese women. METHODS: Twenty-seven obese subjects were randomized into one of two groups: exercise (E) (five 45-min brisk walking sessions per week at 75.2 +/- 0.5% of maximum heart rate) and controls (C). Gallbladder function via cholescintigraphy, cardiorespiratory fitness, and body composition were measured in all subjects before and after a 12-wk intervention period. In each cholescintigraphy trial subjects ingested an 8-oz liquid meal 45 min after injection of 99mTc disofenin to promote gallbladder emptying. Gallbladder areas were then scanned for 60 s and then every 5 min for 60 min. RESULTS: VO2max increased significantly by 9% for E when compared with that for C (P < 0.001). Within E postprandial gallbladder ejection fraction (EF) increased significantly after training (39.5 +/- 4.9% to 54.7 +/- 6.5%, P < 0.05); however, this 15.2% increase in EF was not significantly greater than the change reported in the controls. CONCLUSIONS: Results indicate that 12 wk of moderate exercise training does improve cardiorespiratory fitness but does not significantly effect gallbladder emptying in obese women. 相似文献
43.
Value of serum laminin P1 as a diagnostic and monitoring parameter in transitional cell carcinoma of the bladder. 总被引:2,自引:0,他引:2
K M AbouFarha P P Menheere F H Nieman J W Arends R A Janknegt 《Urologia internationalis》1992,49(3):130-136
In a combined (cross-sectional and longitudinal) study, the serum concentration of laminin P1 was measured by radioimmunoassay in 16 patients with benign inflammatory bladder disorders and 47 patients with transitional cell carcinoma of the bladder. The results were compared with the serum laminin P1 values in 50 healthy control subjects. In the cross-sectional study, the mean value of serum laminin P1 was significantly higher in bladder cancer patients than either the controls (p < 0.0001) or patients with benign inflammatory bladder disorders (p < 0.001). Similarly, the mean values of all different stages of grades of the tumor were significantly higher than either the controls or patients with benign inflammatory disorders. Progressive increase in the mean values of serum laminin P1 could also be found with deterioration of the stage or grade of the tumor. However, the difference between the mean values of the different cancer stages or grades did not reach statistical significance. In the longitudinal study, no significant difference could be detected between the mean values of patients with superficial tumor recurrence and those with remission of the disease (p > 0.5). Nevertheless, in the invasive cancer group, the levels of serum laminin P1 were directly proportional with progression of the disease (Z = 2.94; p < 0.01). 相似文献
44.
45.
Masclee AA; Hopman WP; Corstens FH; Rosenbusch G; Jansen JB; Lamers CB 《Radiology》1989,173(2):407-410
Both ultrasonography (US) and cholescintigraphy are used to study gallbladder dynamics. The present study was undertaken to determine whether the two methods provide the same or different information relating to gallbladder emptying. Emptying was simultaneously studied with both methods during infusion of graded physiologic doses of cholecystokinin (CCK) in six healthy subjects. Infusion of stepwise increasing doses of CCK, ranging from 0.03 to 0.5 Ivy dog units per kilogram of body weight per hour (IDU/kg.h), induced significant dose-related increases in plasma CCK, decreases in gallbladder volume assessed with US, and gallbladder emptying assessed with cholescintigraphy. The threshold dose for inducing significant gallbladder emptying was 0.13 IDU/kg.h, as determined with both techniques, indicating similar detection limits. There was a highly significant correlation between decreases in gallbladder volume and decreases in radioactive counts over the gallbladder region, with a tendency toward greater gallbladder responses at sonography during the early phase of gallbladder contraction and toward greater responses at cholescintigraphy during the later phase of gallbladder contraction. It is concluded that these methods can be used interchangeably for the quantitation of gallbladder emptying. 相似文献
46.
47.
Nieman DC Dumke CL Henson DA McAnulty SR Gross SJ Lind RH 《Brain, behavior, and immunity》2005,19(5):398-403
Muscle damage and perceived soreness following the 160-km Western States Endurance Run were related to changes in plasma cytokines and use of nonsteroidal anti-inflammatory drugs (NSAIDS). Subjects included 60 ultramarathoners (mean+/-SE, age 45.3 +/- 1.1 years) who finished the race in under 30 h (26.3 +/- 0.4 h). Blood samples were collected the morning prior to and immediately following the race, and subjects recorded muscle soreness during the week following the race using a 10-point Likert scale (DOMS). Seven plasma cytokines were measured including IL-6, IL-10, IL-8, IL-1ra, granulocyte colony-stimulating factor (G-CSF), monocyte chemotactic protein 1 (MCP-1), and macrophage inflammatory protein 1beta (MIP-1beta). Cytokine changes were compared between NSAID users and nonusers, and correlated with creatine phosphokinase (CPK) and DOMS. Significant increases were measured for all seven cytokines, with the greatest fold increases seen for IL-6 (125x), IL-10 (24x), and G-CSF (12x). CPK was correlated with changes in IL-6, G-CSF, IL-10, IL-1ra, and MCP-1 (r = .49-.68), (P < .001), but not IL-8 or MIP-1beta. DOMS averaged 7.1 +/- 0.3 the day after the race, and 5.0 +/- 0.3, 2.5 +/- 0.2, and 1.6 +/- 0.1 3 days, 5 days, and 7 days post-race, respectively, and each was correlated with CPK (r = .40-.63, P < .001) and changes in IL-6, G-CSF, IL-10, and MCP-1 (r = .28-.77, P < .05). A comparison of NSAID users (72% of athletes) and nonusers showed no differences in CPK or DOMS, but did reveal greater increases in five of seven cytokines in the NSAID users (P < .05). In conclusion, muscle damage in athletes competing in a 160-km race was significantly correlated with post-race DOMS and increases in five of seven cytokines. NSAID users did not experience a reduction in muscle damage or DOMS, but did have higher post-race plasma levels in five of seven cytokines. 相似文献
48.
Utter AC Nieman DC Mulford GJ Tobin R Schumm S McInnis T Monk JR 《Medicine and science in sports and exercise》2005,37(8):1395-1400
PURPOSE: To evaluate the accuracy of leg-to-leg bioelectrical impedance analysis (BIA) in assessing fat-free mass (FFM) using the TBF-300WA in comparison with hydrostatic weighing (HW) and skinfolds (SK) in high-school (HS) wrestlers in a hydrated state. METHODS: Body composition was determined by BIA, HW, and three-site SK in 129 HS wrestlers (mean +/- SD, age: 15.5 +/- 1.3, height 1.70 +/- 0.08 m, body mass 65.6 +/- 13.1 kg). For all methods, body density (Db) was converted to percent body fat (%BF) using the Brozek equation. Hydration state was quantified by evaluating urine specific gravity. RESULTS: There were no significant differences for estimated FFM between BIA (56.9 +/- 8.4 kg) and HW (56.2 +/- 9.9 kg) or between SK (56.1 +/- 8.9 kg) and HW. The standard errors of estimate for FFM with HW as the reference method were 3.64 kg for BIA and 1.97 kg for SK. Significant correlations were found for FFM between HW and BIA (r = 0.93, P < 0.001), and between HW and SK (r = 0.98, P < 0.001). The FFM difference between BIA and HW was significantly correlated with the FFM average of the two methods (r = -0.39, P < 0.001). The FFM difference between SK and HW was also significantly correlated with the FFM average (r = -0.44, P < 0.001). CONCLUSIONS: This study demonstrates that SK should be considered as the preferred field method of estimating the FFM of HS wrestlers because of its greater individual precision than the leg-to-leg BIA method. Although the BIA is an attractive assessment tool and easy to use, it should be recommended as an alternative to the SK method only when trained skinfold technicians are not available. 相似文献
49.
Potlog-Nahari C Stratton P Winkel C Widra E Sinaii N Connors S Nieman LK 《Fertility and sterility》2004,81(6):1507-1512
OBJECTIVE: To determine whether urine VEGF is elevated in women with endometriosis. DESIGN: Prospective observational study. SETTING: Tertiary care government and private hospitals. PATIENT(S): During laparoscopy for pelvic pain or infertility, urine was collected and possible endometriosis lesions were excised. Of 62 women, 40 had histology-proven endometriosis and 22 had no histological proof of the disease. INTERVENTION: None. MAIN OUTCOME MEASURE(S): Urine VEGF-A(121, 165) was measured and compared in women with and without biopsy-proven endometriosis. RESULT(S): Urine VEGF levels corrected for creatinine excretion were similar in women with (83.6 +/- 11.3 pg/mg Cr) and without (88.5 +/- 10.4 pg/mg Cr) endometriosis (P =.77). The frequency distribution of urine VEGF measurements for women with and without endometriosis was similar. No significant difference was noted in urine VEGF levels when comparing endometriosis stages or in those with endometriomas compared to controls. Urine VEGF did not vary significantly over the menstrual cycle or between groups by cycle phase. No cutoff point discriminated individuals with and without the condition. CONCLUSION(S): It is unlikely that urine VEGF-A(121, 165), as measured in this study, will be a useful non-invasive marker for endometriosis. 相似文献
50.
Henson DA Nieman DC Pistilli EE Schilling B Colacino A Utter AC Fagoaga OR Vinci DM Nehlsen-Cannarella SL 《International journal of sport nutrition and exercise metabolism》2004,14(3):308-322
The influence of 6% carbohydrate ingestion and age on PHA-induced lymphocyte proliferation and in vitro cytokine production was studied in 48 runners following a competitive marathon. Runners were randomly assigned to carbohydrate (C; n = 23) and placebo (P; n= 25) groups, with blood samples taken before, immediately after, and 1.5 hr post-race. C versus P ingestion resulted in higher plasma glucose, lower plasma cortisol, reduced neutrophilia, and monocytosis during recovery, but had no effect on the post-exercise reduction in T-lymphocytes or NK cells, or on race times. No group differences were observed for PHA-induced lymphocyte proliferation or cytokine production. However, for all subjects combined, lymphocyte proliferation and IFN-gamma secretion decreased significantly below pre-race values by 1.5 hr of recovery, and these were negatively correlated with plasma cortisol. Young (<50 years; n = 36) and old (>or=50 years; n = 12) runners exhibited parallel post-race declines in lymphocyte proliferation and IFN-gamma secretion, with the older group exhibiting a 33-59% lower proliferation at each time point. In conclusion, PHA-induced lymphocyte proliferation and cytokine production decreased significantly following a marathon, and this decrease was strongly linked to cortisol and only partially linked to T-cell changes. This decrease occurred in both younger and older runners and was not influenced by carbohydrate. 相似文献