全文获取类型
收费全文 | 19350篇 |
免费 | 1561篇 |
国内免费 | 340篇 |
专业分类
耳鼻咽喉 | 4167篇 |
儿科学 | 414篇 |
妇产科学 | 607篇 |
基础医学 | 1913篇 |
口腔科学 | 2000篇 |
临床医学 | 1103篇 |
内科学 | 1802篇 |
皮肤病学 | 639篇 |
神经病学 | 1123篇 |
特种医学 | 336篇 |
外科学 | 2397篇 |
综合类 | 1059篇 |
现状与发展 | 4篇 |
一般理论 | 2篇 |
预防医学 | 1821篇 |
眼科学 | 433篇 |
药学 | 639篇 |
10篇 | |
中国医学 | 167篇 |
肿瘤学 | 615篇 |
出版年
2024年 | 50篇 |
2023年 | 433篇 |
2022年 | 698篇 |
2021年 | 969篇 |
2020年 | 879篇 |
2019年 | 955篇 |
2018年 | 874篇 |
2017年 | 856篇 |
2016年 | 868篇 |
2015年 | 845篇 |
2014年 | 1217篇 |
2013年 | 1817篇 |
2012年 | 916篇 |
2011年 | 949篇 |
2010年 | 762篇 |
2009年 | 850篇 |
2008年 | 818篇 |
2007年 | 759篇 |
2006年 | 676篇 |
2005年 | 578篇 |
2004年 | 510篇 |
2003年 | 444篇 |
2002年 | 383篇 |
2001年 | 352篇 |
2000年 | 321篇 |
1999年 | 256篇 |
1998年 | 224篇 |
1997年 | 222篇 |
1996年 | 186篇 |
1995年 | 181篇 |
1994年 | 142篇 |
1993年 | 121篇 |
1992年 | 130篇 |
1991年 | 113篇 |
1990年 | 85篇 |
1989年 | 97篇 |
1988年 | 90篇 |
1987年 | 58篇 |
1986年 | 50篇 |
1985年 | 92篇 |
1984年 | 76篇 |
1983年 | 58篇 |
1982年 | 64篇 |
1981年 | 38篇 |
1980年 | 43篇 |
1979年 | 35篇 |
1978年 | 24篇 |
1977年 | 26篇 |
1976年 | 24篇 |
1975年 | 18篇 |
排序方式: 共有10000条查询结果,搜索用时 227 毫秒
91.
A. Poobalan L. Aucott W. C. S. Smith A. Avenell R. Jung J. Broom A. M. Grant 《Obesity reviews》2004,5(1):43-50
This paper aims to review the evidence for long‐term effectiveness of weight loss on cholesterol, high‐density lipoprotein (HDL), low‐density lipoprotein (LDL) and triglycerides in overweight/obese people. Current evidence is mostly based on short‐term studies. A systematic review of long‐term lipid outcomes of weight loss in studies published between 1966 and 2001, was conducted. Inclusion criteria included all cohort studies and trials carried out on participants with body mass index of greater than or equal to 28 kg m?2. Studies had at least two weight change measurements and follow‐up of more than 2 years. Thirteen long‐term studies with a follow‐up of more than 2 years were included. Cholesterol has a significant positive linear relationship with weight change (r = 0.89) where change in weight explains about 80% of the cholesterol difference variation (Adj R2 = 0.80). For every 10 kg weight loss a drop of 0.23 mmol L?1 in cholesterol may be expected for a person suffering from obesity or are grossly overweight. Weight loss has long‐term beneficial effects especially on LDL and cholesterol. Weight loss in obese patients should be encouraged and sustained. 相似文献
92.
Monitoring of skin response to sodium lauryl sulphate: clinical scores versus bioengineering methods
The present trial was designed to evaluate clinical scores (single observer) of sodium lauryl sulphate (SLS)-induced skin irritation in a group of subjects (n = 10) over a 10-day period along with various skin function parameters. In order to avoid significant variations due to secondary phenomena, the following parameters were recorded with non-invasive instruments in this order: skin capacitance (C1; arbitrary units; CM420 Corneometer), transepidermal water loss (TEWL; g/m2.h; Evaporimeter) and laser Doppler flowmetry (CBFV: cutaneous blood flow values; Periflux). All examinations were performed during winter on reclined relaxed subjects present for at least 10 min in a test room with controlled temperature and relative humidity (t degrees: 19.5-20.7 degrees C and RH: 47.3-60.3%). The analysis of differential data (delta = value at tx-value before test; 2-way ANOVA) was made on single parameters as a function of site (volar forearm versus neck) and time (from 24 h after 48-h occlusion with 5% SLS up to 10 days later). The profile of erythema scores over time differed between neck and forearm, but the delta CBFV readings with the laser Doppler instrument did not detect significant site-time interactions. Roughness (blind evaluation with palpating finger) and capacitance readings (delta C1) showed significant differences between sites, but the profile over time was similar in both locations. delta TEWL did not differ according to anatomical location. The reason for different erythema scores on neck and forearm might be related to inherent regional variation of optical properties of the skin or to a substantial contribution of SLS-induced roughness to the readings of erythema.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
93.
We reviewed data from 47 patients who were treated for endophthalmitis at our hospital during the 11-year period 1980-90. The most common clinical features were hypopyon (75%), diminished vision (72%), ocular pain (68%), discharge (57%), corneal oedema (51%), conjunctival injection (49%), abnormal red reflex (34%), corneal ulcer (32%) and corneal perforation (6%). A total of 54 isolates were obtained from 41 (87%) of the 47 patients. Gram-positive bacteria were more common (72%), than Gram-negative organisms (22%). Two cases were due to fungi, and herpes simplex virus was isolated from one case. The two most common Gram-positive organisms were coagulase-negative staphylococci (25%), and Staphylococcus aureus (11%), while Pseudomonas aeruginosa predominated among the Gram-negative bacteria isolated (15%). Mixed bacterial species were obtained from 29% of the infected patients, including one from whom Vibrio fluvialis was isolated. Predisposing factors included ocular surgery (60%)--mostly for cataract extraction (47%), penetrating trauma (15%) and periocular (15%) or systemic (11%) infections. All patients received antibiotics (generally chloramphenicol and/or a beta-lactamase-stable penicillin plus an aminoglycoside) prior to culture, when treatment was adjusted according to specific aetiological agents. Seventy-nine per cent of patients received topical or systemic steroids. Vitrectomy (diagnostic and therapeutic) was performed on 21% of patients. Sixty-three per cent of culture-positive patients lost vision (no perception of light) in the affected eye, compared to 17% of culture-negative cases (P < 0.05 Fisher exact test). Similarly, a better visual outcome (acuity of 6/12 or better) was associated with coagulase-negative staphylococcal infection than with streptococcal or fungal infections.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
94.
LUO Zhengqiang CHEN Anmin GUO Fengjin LI Xinzhi 《中德临床肿瘤学杂志》2006,5(2):138-140
Objective: To investigate the expression of integrin α4 in osteosaxcoma and significance. Methods- Forty-six patients with osteosarcoma (Enneking Ⅰ-Ⅲ) were analyzed for the expression of α4 integrin subunit using immunohistochemical method. Results: Twenty-nine (63.04%) of 46 samples demonstrated positive (+-++) integrin α4 expression. Loss expression of integrin α4 was observed in the patients with advanced Enneking stage (P=0.0040) and with metastatic disease at presentation (P=0.0158). Integrin α4 expression correlated with cell differentiation, the level of malignancy and the invasive behavior of osteosaxcoma. Conclusion: The loss expression of integrin α4 subunit might be a predictor indicating the invasive potential of osteosarcoma and play a role in metastasis of osteosaxcoma patients. 相似文献
95.
Ivar Rønnestad Einar Thorsen Kåre Segadal Arvid Hope 《European journal of applied physiology》1994,69(1):32-35
In diving, pulmonary mechanical function is limited by the increased density of the gas breathed. Breathing cold and dry gas may cause an additional increase in airways resistance. We have measured forced vital capacity, forced expired volume in 1 s (FEV1) and forced midexpiratory flow rate (FEF25%–75%) before and after breathing dry or humid gas at 29–32°C during a standardized exercise intensity on a cycle ergometer at an ambient pressure of 3.7 MPa. The atmosphere was a helium and oxygen mixture with a density of 6.8 kg · m–3. Six professional saturation divers aged 26–37 years participated in the study. There were no significant differences in convective respiratory heat loss between the exposures. The mean evaporative heat loss was 67 W (range 59–89) breathing dry gas and 37 W (range 32–43) breathing humid gas, corresponding to water losses of 1.7 g · min–1 (range 1.5–2.2) and 0.9 g · min–1 (range 0.8–1.1), respectively. There was a significant reduction in FEV1 of 4.6 (SD 3.6)% (P<0.05), and in FEF25%–75% of 5.8 (SD 4.7)% (P<0.05) after breathing dry gas. There were no changes after breathing humid gas. By warming and humidifying the gas breathed in deep saturation diving bronchoconstriction may be prevented. 相似文献
96.
97.
98.
99.
100.
Hongbo Zhai Emi Dika Marina Goldovsky Howard I. Maibach 《Skin research and technology》2007,13(2):207-210
BACKGROUND/PURPOSE: If the occlusion time of a closed chamber evaporimeter on the skin is too long, saturation might occur. We previously compared an open chamber and a closed chamber device on healthy volunteers. Comparable data on stripped skin with higher evaporation rates are not available. This study compares the sensitivity and correlation of open and closed chamber devices in a tape-stripping human model. The amount of tape removed SC was also quantified with a protein assay method. METHODS: Ten healthy volunteers (six male and four female; seven Caucasians and three Asian; mean age 38+/-16) were enrolled. In a randomized manner, one forearm was measured by an open chamber device and the opposite by a closed chamber device. After recording baseline measurements, 20 strippings were taken on each test site with tape disks. Transepidermal water loss (TEWL) was measured at the end of 10 and 20 tape strippings at each test site. Stratum corneum (SC) aggregates in the strips was assayed. RESULTS: The mean values obtained from two devices were similar after 10 trips and 20 strips. There was no statistically significant difference. The closed chamber device showed a slightly higher (but not significant) inter-individual coefficient of variation. SC aggregates in the strips were similar and without a statistically significant difference. CONCLUSION: The study suggests that both devices might yield similar TEWL values on stripped human skin in vivo. 相似文献