全文获取类型
收费全文 | 2486篇 |
免费 | 97篇 |
国内免费 | 15篇 |
专业分类
耳鼻咽喉 | 67篇 |
儿科学 | 86篇 |
妇产科学 | 8篇 |
基础医学 | 348篇 |
口腔科学 | 104篇 |
临床医学 | 231篇 |
内科学 | 581篇 |
皮肤病学 | 12篇 |
神经病学 | 221篇 |
特种医学 | 103篇 |
外科学 | 346篇 |
综合类 | 9篇 |
一般理论 | 1篇 |
预防医学 | 134篇 |
眼科学 | 28篇 |
药学 | 130篇 |
中国医学 | 1篇 |
肿瘤学 | 188篇 |
出版年
2023年 | 7篇 |
2022年 | 11篇 |
2021年 | 34篇 |
2020年 | 22篇 |
2019年 | 33篇 |
2018年 | 36篇 |
2017年 | 25篇 |
2016年 | 40篇 |
2015年 | 42篇 |
2014年 | 66篇 |
2013年 | 114篇 |
2012年 | 136篇 |
2011年 | 159篇 |
2010年 | 107篇 |
2009年 | 81篇 |
2008年 | 140篇 |
2007年 | 177篇 |
2006年 | 160篇 |
2005年 | 150篇 |
2004年 | 170篇 |
2003年 | 182篇 |
2002年 | 180篇 |
2001年 | 38篇 |
2000年 | 17篇 |
1999年 | 32篇 |
1998年 | 31篇 |
1997年 | 36篇 |
1996年 | 27篇 |
1995年 | 26篇 |
1994年 | 31篇 |
1993年 | 27篇 |
1992年 | 23篇 |
1991年 | 28篇 |
1990年 | 16篇 |
1989年 | 19篇 |
1988年 | 11篇 |
1987年 | 8篇 |
1986年 | 10篇 |
1985年 | 16篇 |
1984年 | 17篇 |
1983年 | 15篇 |
1982年 | 21篇 |
1981年 | 8篇 |
1980年 | 12篇 |
1979年 | 6篇 |
1978年 | 11篇 |
1977年 | 14篇 |
1976年 | 7篇 |
1975年 | 6篇 |
1957年 | 2篇 |
排序方式: 共有2598条查询结果,搜索用时 0 毫秒
91.
92.
Qingju Wang Markku Alén Arja Lyytikäinen Leiting Xu Fran A Tylavsky Urho M Kujala Heikki Kröger Ego Seeman Sulin Cheng 《Journal of bone and mineral research》2010,25(7):1512-1520
Familial resemblance and diversity in bone structure and strength in adulthood are determined in part during growth. Whether these characteristics are established during gestation or shortly after birth is not known. Total‐body, lumbar spine, and femoral neck size and mass and indices of tibial bending strength and distal radial compressive strength were measured using bone densitometry and quantitative computed tomography in 236 girls at 18.5 years of age. Among them, 219, 141, and 105 girls had crown‐heel length (CHL) and weight recorded at birth and at 6 and 12 months of age, and then height and weight were recorded at 3, 5, 10, 13, and 15 years of age in 181, 176, 127, 111, and 228 girls, respectively. Of these girls, 101 and 93 girls also had bone structure assessed at 11 and 13 years of age, respectively. Similar bone measurements were made once in 78 mother‐father pairs. CHL and weight at birth did not correlate or did so weakly with bone traits in girls at 18 years of age. By contrast, CHL at 6 months correlated with the height, bone traits, and strength at puberty and at 18 years of age (r = 0.24–0.56, p < .001) in girls and with their parents' height and bone traits (r = 0.15–0.37, p < .05). When the girls' CHL at 6 months was stratified into quartiles, the absolute and relative differences in bone traits observed at puberty (~11.5 years) were maintained as these traits tracked during the ensuing 7 years. Similarly, weight at 6 months correlated with the girls' bone traits at puberty and 18 years of age (r = 0.22–0.55, p < .05). During puberty and at 18 years of age, the girls' bone traits correlated with the corresponding traits in their parents (r = 0.32–0.43, p < .01). It is concluded that familial resemblance in bone structural strength and the position of an individual's bone traits relative to others in adulthood are likely to be established during the first year of life. Thus susceptibility to bone fragility late in life has its antecedents established early in life. © 2010 American Society for Bone and Mineral Research 相似文献
93.
Mikael Kajanti Martti Flander Reidar Grenman Tenho Hietanen Maija Romppanen Marita Turunen Ritva Valavaara Heikki Joensuu 《Acta oncologica (Stockholm, Sweden)》1996,35(6):697-702
The nationwide experience of treating nasopharyngeal cancer in Finland during the period 1980-1989 was reviewed. Of the 107 patients included in the present analysis, 13 were treated palliatively only, and three had metastatic disease at their first clinical presentation, whereas the rest (n = 91) were treated with radical radiotherapy, of whom, 8 patients received adjuvant chemotherapy after radiotherapy. The 5-year actuarial survival rates of these 91 patients was 52%, and by the UICC stage they were classified as follows: stage I 75% (n = 12), stage II 60% (n = 5), stage III 59% (n = 34), and stage IV 38% (n = 40). According to the Cox's stepwise proportional hazard model the most important factors influencing favourable survival were the total dose of radiotherapy expressed in terms of Biologically Effective Dose (BED) with a time factor, a small size of the primary tumour and a high performance status according to the WHO scale, whereas the most important factors influencing the local control analysis were the total dose of radiotherapy (expressed in BED) and the cervical lymph node status. 相似文献
94.
Factors explaining recurrence in patients undergoing chemoimmunotherapy regimens for frequently recurring superficial bladder carcinoma 总被引:4,自引:0,他引:4
Kaasinen E Rintala E Hellström P Viitanen J Juusela H Rajala P Korhonen H Liukkonen T;FinnBladder Group 《European urology》2002,42(2):167-174
OBJECTIVES: To study the factors determining new recurrences in patients with frequently recurring superficial bladder tumors. METHODS: Of all 205 eligible patients, each received 5 weekly intravesical instillations of mitomycin C (MMC), with the first instillation given perioperatively. This was followed, according to randomization, by BCG instillations alone or by alternating instillations of interferon-alpha and BCG monthly for up to 1 year. Impact of 12 variables on time to first recurrence was retrospectively studied with the Cox multiple hazards regression and Kaplan-Meier analysis. RESULTS: Type of regimen was the most significant factor determining new recurrences, with preceding recurrence rate being the most important prognostic factor. Timing of the first MMC was the third significant predictor in the main multivariate analysis, with more than a two-fold relative risk for a new recurrence if the first MMC instillation was given later than on day 0. CONCLUSION: Preceding recurrence rate, most accurately reflects, in patients with frequently recurring tumors, the inherent risk for new recurrences. This risk can be considerably reduced by use of an effective chemoimmunotherapy regimen, and in addition, by inclusion of an early perioperative chemotherapy instillation in such a regimen. 相似文献
95.
A reversed-phase HPLC method was developed using a computer simulation program for the identification of dried roots of Echinacea purpurea, E. angustifolia, E. pallida and Parthenium integrifolium. Hydrophilic and lipophilic compounds were analysed simultaneously leading to a two-fold decrease in analysis time compared to traditional HPLC methods. 相似文献
96.
Kerkelä R Ilves M Pikkarainen S Tokola H Ronkainen J Vuolteenaho O Leppäluoto J Ruskoaho H 《Molecular pharmacology》2002,62(6):1482-1491
Members of the mammalian protein kinase C (PKC) superfamily play key regulatory roles in multiple cellular processes. In the heart, PKC signaling is involved in hypertrophic agonist-induced gene expression and hypertrophic growth. To investigate the specific function of PKC signaling in regulating cardiomyocyte growth, we used antisense oligonucleotides to inhibit PKC alpha, the major isozyme present in the neonatal heart. Transfection of cultured neonatal cardiomyocytes with antisense PKCalpha oligonucleotides resulted in a marked reduction in both PKCalpha mRNA and protein levels. PKCalpha antisense treatment also reduced phenylephrine (PE)-induced PKC activity and perinuclear translocation of PKCalpha. Antisense inhibition of PKCalpha led to reduction of PE-induced increase in skeletal alpha-actin mRNA levels and atrial natriuretic peptide (ANP) secretion but had no significant effects on PE-induced beta-myosin heavy chain, ANP, or B-type natriuretic peptide (BNP) gene expression. On the other hand, antisense PKCalpha treatment attenuated endothelin-1-induced increase in ANP and BNP peptide secretion, whereas endothelin-1-induced gene expression of ANP and BNP remained unchanged. The hypertrophic agonist-induced growth of cardiomyocytes, characterized by increased [(3)H]leucine incorporation, was not affected with antisense PKCalpha treatment. Furthermore, we found that PE-induced increase in extracellular signal-regulated kinase (ERK) activity was partially inhibited by antisense PKCalpha treatment, implicating ERK as a downstream mediator for PKCalpha signaling. These results indicate that PKCalpha isozyme is involved in hypertrophic signaling in cardiomyocytes and provide novel strategies for future studies to identify other cellular targets controlled selectively by PKCalpha or other PKC isozymes. 相似文献
97.
98.
99.
We assessed changes in periodontal treatment needs among patients with diabetes and the risk factors involved in this phenomenon. The sample consisted of 120 dentate subjects, all of whom were regular patients at the Salo Regional Hospital Diabetes Clinic. They underwent periodontal examination in 1999 and were re-examined in 2001. The drop-out rate was 4%. Clinical periodontal examination included identification of visible plaque, the presence of calculus, and use of the Community Periodontal Index of Treatment Needs (CPITN) index. Diabetes-related factors consisted of information about duration of diabetes, complications, and HbA1c values. Oral health-related factors were collected by questionnaire. The CPITN index proved to be insensitive to change. Pathological pockets (CPITN 3 or 4) were found in 80% of subjects (n = 115) and 48% of sextants (n = 627); in 1999, the corresponding rates were 77% and 49%. The tooth-based individual CPITN index (code 3 or 4) revealed periodontal deterioration in 38 patients. Smoking and infrequent interdental cleaning were significant factors explaining periodontal deterioration in logistic regression. Risk factors should be taken into account when planning prevention, treatment, and supportive periodontal therapy strategies. In diabetes care, the common risk factor approach can be implemented to promote oral health among individuals with diabetes. 相似文献
100.
Effects of calcium and plant sterols on serum lipids in obese Zucker rats on a low-fat diet 总被引:2,自引:0,他引:2
Vaskonen T Mervaala E Sumuvuori V Seppänen-Laakso T Karppanen H 《The British journal of nutrition》2002,87(3):239-245
Ca may interfere with fat and cholesterol metabolism through formation of insoluble soaps with fatty and bile acids in the intestine. In the present study, we examined the effects of different dietary Ca levels on the serum lipid profile and cholesterol metabolism in obese Zucker rats fed a low-fat diet. We also tested whether dietary Ca interfered with the lipid-lowering effects of a pine oil-derived plant sterol mixture. Increase in dietary Ca intake from 0.2 to 0.8%, and further to 2.1% (w/w) dose-dependently decreased serum total cholesterol (r -0.565, P=0.002, n 27), LDL-cholesterol (r -0.538, P=0.006, n 25), and triacylglycerol (r -0.484, P=0.014, n 25) concentrations, and increased HDL-cholesterol (r -0.478, P=0.016, n 25) and HDL: LDL cholesterol (r 0.672, P<0.001, n 25) in rats fed a 1% cholesterol diet. Analysis of serum campesterol: cholesterol and sitosterol: cholesterol suggested that Ca dose-dependently increased intestinal cholesterol absorption (r 0.913, P<0.001, n 18), whereas serum desmosterol: cholesterol and lathosterol: cholesterol indicated that Ca dose-dependently increased endogenous cholesterol synthesis (r 0.691, P=0.003, n 18). Therefore, the decrease of serum LDL-cholesterol appeared to be due to Ca-induced increase in the conversion of cholesterol to bile acids. The increase in Ca intake did not interfere with the beneficial effects of plant sterols on serum total cholesterol, LDL-cholesterol and HDL-cholesterol concentrations. The high-Ca diet with plant sterol supplementation further increased the HDL-cholesterol concentration and HDL: LDL cholesterol. The present findings indicate that the beneficial effects of dietary Ca on the serum lipid profile during a low-fat diet are dose-dependent, and resemble those of bile acid sequestrants. Increased dietary Ca did not impede the lipid-lowering effects of natural plant sterols. 相似文献