全文获取类型
收费全文 | 1460篇 |
免费 | 133篇 |
国内免费 | 12篇 |
专业分类
耳鼻咽喉 | 11篇 |
儿科学 | 28篇 |
妇产科学 | 13篇 |
基础医学 | 204篇 |
口腔科学 | 16篇 |
临床医学 | 289篇 |
内科学 | 262篇 |
皮肤病学 | 5篇 |
神经病学 | 141篇 |
特种医学 | 131篇 |
外科学 | 107篇 |
综合类 | 52篇 |
预防医学 | 125篇 |
眼科学 | 4篇 |
药学 | 146篇 |
中国医学 | 2篇 |
肿瘤学 | 69篇 |
出版年
2023年 | 10篇 |
2022年 | 11篇 |
2021年 | 18篇 |
2018年 | 19篇 |
2017年 | 19篇 |
2016年 | 15篇 |
2015年 | 24篇 |
2014年 | 39篇 |
2013年 | 47篇 |
2012年 | 41篇 |
2011年 | 44篇 |
2010年 | 36篇 |
2009年 | 28篇 |
2008年 | 49篇 |
2007年 | 36篇 |
2006年 | 40篇 |
2005年 | 32篇 |
2004年 | 43篇 |
2003年 | 35篇 |
2002年 | 40篇 |
2001年 | 46篇 |
2000年 | 38篇 |
1999年 | 51篇 |
1998年 | 35篇 |
1997年 | 27篇 |
1996年 | 35篇 |
1995年 | 27篇 |
1994年 | 24篇 |
1993年 | 23篇 |
1992年 | 48篇 |
1991年 | 34篇 |
1990年 | 48篇 |
1989年 | 45篇 |
1988年 | 50篇 |
1987年 | 50篇 |
1986年 | 41篇 |
1985年 | 49篇 |
1984年 | 32篇 |
1983年 | 33篇 |
1982年 | 20篇 |
1981年 | 9篇 |
1980年 | 15篇 |
1979年 | 16篇 |
1978年 | 22篇 |
1977年 | 19篇 |
1976年 | 14篇 |
1975年 | 14篇 |
1974年 | 19篇 |
1971年 | 14篇 |
1970年 | 15篇 |
排序方式: 共有1605条查询结果,搜索用时 15 毫秒
1.
Fluid role boundaries: exploring the contribution of the advanced nurse practitioner to multi‐professional palliative care 下载免费PDF全文
2.
Peripheral administrations of TFMPP (0.2- 1 mg/kg) or MCPP (1 mg/kg) facilitated lordosis behavior in female rats treated with estradiol benzoate, and had no effects in females primed with estradiol benzoate and progesterone. In contrast, TFMPP (1 mg/kg) and MCPP (1 mg/kg) inhibited copulatory behavior in male rats. It is concluded that there are sex differences in the effects of TFMPP and MCPP on copulatory behavior in the rat. Moreover, it is suggested that the effects of these drugs on copulatory behavior may be mediated by activation of 5-HT1B and/or 5-HT1C receptors, or by blockade of activity at 5-HT3 receptors. 相似文献
3.
E B Mendelson 《Radiologic clinics of North America》1992,30(1):107-138
With widespread use of mammography for breast cancer screening, the number of surgical procedures has also increased. Overlapping with radiographic signs of malignancy, including masses, areas of asymmetric density and architectural distortion, microcalcifications, and skin thickening, postsurgical changes may make mammographic evaluation difficult. After tumor excision and irradiation where breast alterations are more profound and prolonged, the task of distinguishing recurrent tumor from scarring or fat necrosis is even more challenging. Mammograms after breast conservation therapy for carcinoma or after cosmetic surgery require correlation with physical findings and the surgical procedures that were performed. Responses of tissue to lumpectomy and radiation, such as breast edema and skin thickening, are most pronounced 6 to 12 months after treatment, gradually resolving within 1 to 3 years. Carefully tailored mammographic studies will promote the dual goal of early detection of local tumor recurrence and avoidance of misinterpreting postoperative and irradiation changes as malignancy. Sequential examinations should begin with a postoperative preradiation mammogram for residual carcinoma, particularly when microcalcifications have been present, followed by the baseline postradiation examination at 6 months with the next study 6 months later (1 year after initial treatment). Mammograms of the treated breast may be performed at intervals of 6 months until radiographic stability has been recognized. Annual studies thereafter are suggested. The contralateral, unaffected breast should be evaluated mammographically according to screening guidelines or clinical concerns. Mammograms performed after cosmetic and reconstructive procedures should be correlated with the surgical techniques and clinical history. Modified views for silicone implants can maximize visualization of breast parenchyma. Ultrasonography is a useful complement to mammography in demonstrating the origin of a palpable mass either within the implant or the breast parenchyma. In reduction mammoplasty, distorted architecture, parenchymal bands, tissue redistribution, and fat necrosis should be recognized. After mastectomy, myocutaneous reconstruction may be performed. Masses that develop within flap reconstructions most frequently represent fat necrosis, which, when calcifying oil cysts are seen, may have a characteristic radiographic appearance. 相似文献
4.
Peter J. Franks PhD ; Hanne Winterberg RGN DN BSc ; Christine J. Moffatt RGN PhD 《Wound repair and regeneration》2002,10(3):133-140
Little is known of the impact of pressure ulceration on adult patients' health-related quality of life. The purpose of this study was to determine the impact pressure ulceration has on pressure ulcer patients cared for in the community. A case control study design was used by drawing a random sample from patients receiving community nursing care, stratified by the presence of pressure ulceration. In all, 75 patients with pressure ulcers were compared with 100 controls without ulcers using the four-point ulcer grading scale described by United Kingdom consensus guidelines. Patients were interviewed using the Short Form-36 (SF-36) questionnaire and activities of daily living assessed using the modified Barthel scale. Patients with pressure ulcers had significantly poorer physical function (mean difference (d) = 37.6, 95% CI 28.6-46.6, p < 0.001) and social functioning (d = 33.9, 95 % CI 24.0-43.9, p < 0.001) than published age- and sex-matched normative data from the United Kingdom. The difference between cases and controls was much smaller in these domains, with neither approaching statistical significance. After adjustment for age and gender, scores for bodily pain were poorer in patients with no ulceration (d = -10.5, 95% CI - 20.6 to - 0.4, p = 0.042) indicating greater pain in these patients compared with the cases with ulceration. Activities of daily living determined by the modified Barthel scale showed reduced self-care (d = -7.6, 95% CI -12.5 to - 2.7, p = 0.010) and mobility (d = -9.2, 95% CI -14.6 to - 3.8, p = 0.001) in patients with pressure ulceration. The overall ability to perform these activities was also significantly poorer in this group (d = -16.3, 95% CI -27.3 to -5.3, p = 0.004). While patients with pressure ulceration experience some deficits in their health-related quality of life compared with a normal population, these differences are similar to those experienced by other patients receiving community nursing care. 相似文献
5.
Sex differences in plasma cocaine levels and subjective effects after acute cocaine administration in human volunteers 总被引:3,自引:3,他引:0
S. E. Lukas M. Sholar L. H. Lundahl X. Lamas E. Kouri J. D. Wines L. Kragie J. H. Mendelson 《Psychopharmacology》1996,125(4):346-354
Gender differences after acute cocaine administration have received little attention in spite of the fact that males and females respond differently to many drugs. Seven male and seven female occasional cocaine users received both an intranasal dose of cocaine hydrochloride (0.9 mg/kg) and placebo powder in a randomized order and reported subjective effects via an instrumental joystick device and various questionnaires. Blood samples were withdrawn at 5-min intervals to assess pharmacokinetic differences. Male subjects achieved the highest peak plasma cocaine levels (144.4 ± 17.5 ng/ml), detected cocaine effects significantly faster than females and also experienced a greater number of episodes of intense good and bad effects. Women studied during the follicular phase of their menstrual cycle had peak plasma cocaine levels of 73.2 ± 9.9 ng/ml, which was significantly higher than when they were studied during their luteal phase (54.7 ± 8.7 ng/ml), but there were no differences in their subjective reports of cocaine effects. In spite of the different cocaine blood levels and subjective effects, peak heart rate increases did not differ between males and females suggesting that women may be more sensitive than males to the cardiovascular effects of cocaine. These data suggest that there are significant gender and menstrual cycle differences in the response to acute intranasal cocaine administration and these differences may have implications for the differential abuse of this drug.This paper is dedicated to Xavier Lamas, MD, PhD, who lost his life while ascending Mt. Everest, August 1995 相似文献
6.
D S Mendelson B D Berson C L Janus E S Gendal D J Krellenstein 《Journal of computer assisted tomography》1988,12(5):881-884
A patient undergoing treatment for abdominal lymphoma presented with a superior vena cava (SVC) syndrome. The presence of a wide mediastinum and "nodular" mediastinal densities on CT presented a diagnostic problem, necessitating thoracotomy. The thoracotomy was negative for tumor or infection. We believe that the presence of an indwelling catheter and mediastinal lipomatosis resulted in the SVC syndrome. The "nodular" densities represented an unusual set of mediastinal collaterals that must be distinguished from adenopathy. 相似文献
7.
Sleep apnea syndrome in chronic renal disease 总被引:10,自引:0,他引:10
PURPOSE: We performed this study in order to expand on an earlier report indicating a high prevalence of the sleep apnea syndrome in male patients with end-stage renal disease treated with hemodialysis and to determine whether patients with chronic renal insufficiency (prior to the initiation of therapy for end-stage renal disease) and female patients with end-stage renal disease treated with hemodialysis were affected. PATIENTS AND METHODS: Polysomnography was performed in 26 male and female patients with chronic renal insufficiency and end-stage renal disease treated with hemodialysis who were not receiving testosterone. They included 22 whose histories were suggestive of sleep apnea ("symptomatic") and four whose histories were not ("asymptomatic"). RESULTS: Sixteen of the symptomatic (73 percent) and none of the asymptomatic patients were found to have clinically significant sleep apnea syndrome (p less than 0.02). Both female patients and patients with chronic renal insufficiency had sleep apnea. In nine of these 16 cases, the disorder was primarily of the obstructive type. CONCLUSION: These preliminary data raise the possibility of an association of chronic renal disease and the sleep apnea syndrome, and suggest that some of the daytime sleepiness and disturbed nocturnal sleep in such patients may be related to sleep apnea. They also indicate that questioning patients with chronic renal disease and symptoms suggestive of a sleep disorder is useful in determining who are at high risk for the sleep apnea syndrome. Further study is required to establish a causal relationship between chronic renal disease and the sleep apnea syndrome, and to determine the prevalence of the latter in patients with end-stage renal disease. 相似文献
8.
9.
Ability of National Committee for Clinical Laboratory Standards-recommended quality control strains from the American Type Culture Collection to detect errors in disk diffusion susceptibility tests. 下载免费PDF全文
A Yechouron A Dascal J Stevenson J Mendelson 《Journal of clinical microbiology》1991,29(12):2758-2762
The National Committee for Clinical Laboratory Standards (NCCLS) recommends, as a quality control for the disk diffusion susceptibility test, the use of three strains from the American Type Culture Collection: Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853, and Escherichia coli ATCC 25922. This study assesses the capacity of these strains to detect errors in the overall method. ATCC strains were tested by comparing testing by the standard NCCLS-recommended procedure (ST) with testing under the following conditions: incubation at 25 degrees C, Mueller-Hinton agar depths of 2 mm (AD2) and 8 mm (AD8), agar pHs of 6.5 and 8, inocula with McFarland standards of 0.25 (0.25M) and 4.0 McFarland (4.0M), direct inoculation without preincubation of inoculum (DI), and a 2-h delay between inoculation and disk application (2HR). The frequency of zone measurements outside the NCCLS-recommended control zone limits were as follows: ST, 0%; AD2, 18%; AD8, 9.6%; pH 6.5, 7.9%; pH 8, 5.3%; 0.25M, 3.5%; 4.0M, 24%; DI, 3.4%; 2HR, 1.8%; 25 degrees C (only E. coli and P. aeruginosa were evaluable), 28%. These results suggest that the quality control strains are only partially effective in detecting single extreme laboratory errors and that careful laboratory supervision is necessary even in the setting of properly monitored quality control strains. 相似文献
10.
Molecular and antigenic characterization of a highly evolved derivative of the type 2 oral poliovaccine strain isolated from sewage in Israel 总被引:13,自引:0,他引:13 下载免费PDF全文
Shulman LM Manor Y Handsher R Delpeyroux F McDonough MJ Halmut T Silberstein I Alfandari J Quay J Fisher T Robinov J Kew OM Crainic R Mendelson E 《Journal of clinical microbiology》2000,38(10):3729-3734
An unusual, highly diverged derivative of the Sabin type 2 oral poliovaccine (OPV) strain was recovered from environmental samples during routine screening for wild polioviruses. Virus was cultivated in L20B cells and then passaged on BGM cells at 40 degrees C (RCT [reproductive capacity at supraoptimal temperature]-positive marker) to select against most OPV strains. All but 1 of 25 RCT-positive OPV-derived environmental isolates were antigenically and genetically (>99.5% VP1 sequence match) similar to the respective Sabin strains. However, isolate PV2/4568-1/ISR98 (referred to below as 4568-1) escaped neutralization with Sabin 2-specific monoclonal antibodies and cross-adsorbed sera, and had multiple nucleotide substitutions (220 of 2,646; 8.3%) in the P1 capsid region. Fourteen of the 44 associated amino acid substitutions in the capsid mapped to neutralizing antigenic sites. Neutralizing titers in the sera of 50 Israeli children 15 years old were significantly lower to 4568-1 (geometric mean titer [GMT], 47) than to Sabin 2 (GMT, 162) or to the prototype wild strain, PV2/MEF-1/EGY42 (GMT, 108). Two key attenuating sites had also reverted in 4568-1 (A(481) to G in the 5' untranslated region and the VP1 amino acid I(143) to T), and the isolate was highly neurovirulent for transgenic mice expressing the poliovirus receptor (PVR-Tg21 mice). The extensive genetic divergence of 4568-1 from the parental Sabin 2 strain suggested that the virus had replicated in one or more people for approximately 6 years. The presence in the environment of a highly evolved, neurovirulent OPV-derived poliovirus in the absence of polio cases has important implications for strategies for the cessation of immunization with OPV following global polio eradication. 相似文献