全文获取类型
收费全文 | 13492篇 |
免费 | 906篇 |
国内免费 | 29篇 |
专业分类
耳鼻咽喉 | 122篇 |
儿科学 | 420篇 |
妇产科学 | 483篇 |
基础医学 | 1803篇 |
口腔科学 | 132篇 |
临床医学 | 2579篇 |
内科学 | 2314篇 |
皮肤病学 | 242篇 |
神经病学 | 1176篇 |
特种医学 | 253篇 |
外科学 | 1122篇 |
综合类 | 109篇 |
一般理论 | 17篇 |
预防医学 | 1738篇 |
眼科学 | 121篇 |
药学 | 831篇 |
中国医学 | 12篇 |
肿瘤学 | 953篇 |
出版年
2023年 | 51篇 |
2022年 | 89篇 |
2021年 | 208篇 |
2020年 | 134篇 |
2019年 | 253篇 |
2018年 | 295篇 |
2017年 | 182篇 |
2016年 | 238篇 |
2015年 | 266篇 |
2014年 | 395篇 |
2013年 | 658篇 |
2012年 | 971篇 |
2011年 | 1042篇 |
2010年 | 539篇 |
2009年 | 488篇 |
2008年 | 1015篇 |
2007年 | 1039篇 |
2006年 | 1027篇 |
2005年 | 990篇 |
2004年 | 935篇 |
2003年 | 870篇 |
2002年 | 892篇 |
2001年 | 93篇 |
2000年 | 62篇 |
1999年 | 123篇 |
1998年 | 204篇 |
1997年 | 131篇 |
1996年 | 123篇 |
1995年 | 104篇 |
1994年 | 94篇 |
1993年 | 90篇 |
1992年 | 60篇 |
1991年 | 51篇 |
1990年 | 59篇 |
1989年 | 46篇 |
1988年 | 47篇 |
1987年 | 43篇 |
1986年 | 40篇 |
1985年 | 35篇 |
1984年 | 43篇 |
1983年 | 49篇 |
1982年 | 62篇 |
1981年 | 52篇 |
1980年 | 49篇 |
1979年 | 22篇 |
1978年 | 30篇 |
1977年 | 20篇 |
1976年 | 22篇 |
1975年 | 18篇 |
1974年 | 18篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
13.
14.
Sheetal Chopra Anna S Lev-Toaff Fatih Ors Diane Bergin 《Journal of ultrasound in medicine》2006,25(5):617-27; quiz 629
OBJECTIVE: The purpose of this presentation is to show the imaging findings of the common and uncommon variants of adenomyosis as seen on sonography and magnetic resonance imaging (MRI). METHODS: A 3-year database search was performed to identify women who had pelvic sonography and pelvic MRI within a 6-month interval. Images of these cases were retrospectively reviewed. RESULTS: Eighty women were identified. Adenomyosis was diagnosed on MRI, which was used as the reference standard, in 45 of these women. The correct diagnosis was made on sonography in 73% of the cases. CONCLUSIONS: Awareness of the spectrum of imaging features of adenomyosis is important to use sonography effectively for diagnosing this entity and to help avoid misdiagnosis. 相似文献
15.
Impact of smoking on cancer stage at diagnosis. 总被引:2,自引:0,他引:2
Nathan L Kobrinsky Marilyn G Klug Peggy Jo Hokanson Diane E Sjolander Larry Burd 《Journal of clinical oncology》2003,21(5):907-913
BACKGROUND: Studies evaluating the relationship between smoking and cancer spread are limited. METHODS: We studied the relationship between cancer stage at diagnosis (local, regional, or metastatic) and smoking history (current, previous, or nonsmoker). For lung cancer, patterns of spread were also studied. RESULTS: In a tumor registry for eastern North Dakota, northwestern Minnesota, and northern South Dakota, 11,716 cases were identified from 1986 to 2001. Current smokers (relative risk [RR], 2.11; 95% confidence interval, 1.93 to 2.32; P <.001) and previous smokers (RR, 1.56; 95% confidence interval, 1.42 to 1.72; P <.001) had an increased risk of metastatic disease at diagnosis. Current smokers (RR, 1.39; 95% confidence interval, 1.29 to 1.51; P <.001), but not previous smokers, also had an increased risk of regional disease. An increase in metastatic disease was most evident for prostate cancer (RR, 1.53; P =.003). An increase in regional disease was most evident for head and neck (RR, 3.53; P <.001), prostate (RR, 1.83; P =.030), and breast cancer (RR, 1.22; P =.005). Compared with previous smokers, current smokers with metastatic lung cancer were more likely to have involvement of the brain (33.6% v 23.0%; P =.004), bone marrow, adrenal gland, and pericardium (24.7% v 15.9%; P =.004). CONCLUSION: Previous or current smoking is a risk factor for increased cancer stage in a wide range of malignancies. Further study is required to determine whether this association is causal. 相似文献
16.
17.
Sheryl A. Scott Seth Dinowitz Kristen Terhaar Diane Sherlock Maurice A. Campbell Dreania Levine 《The Journal of comparative neurology》1994,350(2):302-310
The goal of the present study was to identify cytochemical markers characteristic of muscle afferents in hatchling chicks. To this end, we stained neurons in the trigeminal mesencephalic nucleus with a variety of markers that label subsets of neurons in avian dorsal root ganglia. We found that trigeminal mesencephalic neurons are surprisingly heterogeneous in their cytochemical make-up, expressing, to varying degrees, substance P, cholecystokinin, carbonic anhydrase, calbindin D-28k, parvalbumin, and S-100β. Calbindin D28k and S-100β appeared to be expressed equally in medial and lateral divisions of the trigeminal mesencephalic nucleus. In contrast, substance P- and cholecystokinin-immunoreactive neurons were more abundant in the medial division, whereas carbonic anhydrase activity and parvalbumin immunoreactivity were stronger in the lateral division. We were unable to detect met-enkephalin, neuropeptide Y, calcitonin gene-related peptide, vasoactive intestinal peptide, somatostatin, γ-aminobutyric acid, or tyrosine hydroxylase in the trigeminal mesencephalic nucleus. Moreover, these neurons did not appear to bind the lectin Dolichos biflorus agglutinin. The heterogeneity of expression of markers among trigeminal mesencephalic nucleus neurons, especially between neurons in the medial and lateral divisions, suggests that these neurons are functionally diverse. 相似文献
18.
19.
Clinical trial of a prevention and treatment protocol for skin breakdown in two nursing homes. 总被引:1,自引:0,他引:1
Susan Hunter Julie Anderson Darlene Hanson Patricia Thompson Diane Langemo Marilyn G Klug 《Journal of wound, ostomy, and continence nursing》2003,30(5):250-258
OBJECTIVE: Our objective was to assess the effectiveness of skin care protocols, including a body wash and skin protectant, on skin breakdown in 2 nursing homes. DESIGN: This was a quasi-experimental pretest/posttest design study.Setting and subjects Adult residents (n = 136) of 2 skilled nursing homes consented to participate in this study. Seventy percent were women; the sample average age of 82 years. INSTRUMENTS: A researcher-designed data recording form documented resident demographics, incidence and type of skin breakdown or pressure ulcer, presence of urinary or fecal incontinence, and assessment of the effectiveness of body wash and skin protectant. METHODS: Baseline data on prevalence of pressure ulcers and skin protocol were collected weekly for a 3-month period followed by a week-long educational program by the researchers about skin care and the body wash and skin protectant. During the 3-month trial with the body wash and skin protectant incorporated into routine care, research assistants recorded resident data weekly and researchers again assessed prevalence and incidence of pressure ulcers and skin breakdown weekly. RESULTS: Incorporation of a body wash and skin protectant into a skin care prevention and early intervention protocol in 2 nursing homes documented a decrease in skin breakdowns from 68 pre-intervention to 40 postintervention; the decrease in agency B was statistically significant. There was a statistically significant decrease in stage I and II pressure ulcer incidence overall (pre-intervention = 19.9%, postintervention = 8.1%). Nurses evaluated the body wash and skin protectant as effective for 98% of the time used. CONCLUSION: Implementation of a protocol for skin care along with staff education, including the prophylactic use of a body wash and skin protectant, reduced the incidence of skin breakdown, including pressure ulcers and perineal dermatitis, in 2 long-term care facilities. 相似文献
20.