全文获取类型
收费全文 | 16676篇 |
免费 | 991篇 |
国内免费 | 81篇 |
专业分类
耳鼻咽喉 | 132篇 |
儿科学 | 425篇 |
妇产科学 | 418篇 |
基础医学 | 2626篇 |
口腔科学 | 663篇 |
临床医学 | 1386篇 |
内科学 | 3692篇 |
皮肤病学 | 341篇 |
神经病学 | 1965篇 |
特种医学 | 451篇 |
外科学 | 1484篇 |
综合类 | 41篇 |
一般理论 | 5篇 |
预防医学 | 1014篇 |
眼科学 | 275篇 |
药学 | 1360篇 |
中国医学 | 57篇 |
肿瘤学 | 1413篇 |
出版年
2024年 | 18篇 |
2023年 | 171篇 |
2022年 | 394篇 |
2021年 | 597篇 |
2020年 | 360篇 |
2019年 | 478篇 |
2018年 | 574篇 |
2017年 | 451篇 |
2016年 | 524篇 |
2015年 | 653篇 |
2014年 | 739篇 |
2013年 | 941篇 |
2012年 | 1471篇 |
2011年 | 1568篇 |
2010年 | 777篇 |
2009年 | 744篇 |
2008年 | 1169篇 |
2007年 | 1097篇 |
2006年 | 1023篇 |
2005年 | 932篇 |
2004年 | 835篇 |
2003年 | 759篇 |
2002年 | 649篇 |
2001年 | 78篇 |
2000年 | 55篇 |
1999年 | 69篇 |
1998年 | 106篇 |
1997年 | 94篇 |
1996年 | 61篇 |
1995年 | 58篇 |
1994年 | 42篇 |
1993年 | 30篇 |
1992年 | 19篇 |
1991年 | 19篇 |
1990年 | 12篇 |
1989年 | 26篇 |
1988年 | 17篇 |
1987年 | 24篇 |
1986年 | 15篇 |
1985年 | 14篇 |
1984年 | 13篇 |
1983年 | 15篇 |
1982年 | 13篇 |
1981年 | 12篇 |
1980年 | 5篇 |
1979年 | 5篇 |
1978年 | 4篇 |
1975年 | 4篇 |
1973年 | 6篇 |
1972年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
981.
Association of peroxisome proliferator-activated receptor gamma 2 Pro-12-Ala polymorphism with endometriosis 总被引:4,自引:0,他引:4
Dogan S Machicao F Wallwiener D Haering HU Diedrich K Hornung D 《Fertility and sterility》2004,81(5):1411-1413
We explored the association of the PPAR-gamma2 (peroxisome proliferator-activated receptor) Pro-12-Ala polymorphism with endometriosis in a case-control study with 51 women with endometriosis stages I-IV and 55 control women without endometriosis. The 12-Pro allele of PPAR-gamma2 may have protective effects avoiding the development and progression of endometriosis. 相似文献
982.
Effects of metformin and rosiglitazone, alone and in combination, in nonobese women with polycystic ovary syndrome and normal indices of insulin sensitivity 总被引:12,自引:0,他引:12
Baillargeon JP Jakubowicz DJ Iuorno MJ Jakubowicz S Nestler JE 《Fertility and sterility》2004,82(4):893-902
OBJECTIVE: To determine whether insulin-sensitizing drugs would improve ovulation and T levels in women with polycystic ovary syndrome (PCOS), without clinical or biochemical criteria indicating insulin resistance and whether the combination of two distinct insulin-sensitizing drugs would be of any benefit over either drug alone. DESIGN: Randomized controlled double-blind trial. SETTING: A referral center in Caracas, Venezuela. PATIENT(S): One hundred twenty-eight nonobese PCOS women with normal indices of insulin sensitivity-that is, normal glucose tolerance, fasting insulin, peak insulin during an oral glucose tolerance test (OGTT), and fasting glucose-to-insulin ratio. Twenty-eight women were lost to follow-up initially and did not receive any intervention. INTERVENTION(S): One hundred women received twice daily one of the following for 6 months: metformin (850 mg), rosiglitazone (4 mg), combination of both drugs, or at least one placebo. MAIN OUTCOME MEASURE(S): Frequencies of ovulation and serum free T after 6 months. RESULT(S): Frequencies of ovulation were higher after treatment with an insulin-sensitizing drug (ovulations per subject in 6 months: metformin, 3.3; rosiglitazone, 2.4; and combination, 3.4) than with placebo (0.4). Ovulatory frequencies increased significantly more with metformin than rosiglitazone, and the combination was not more potent. After treatment, serum free-T levels were comparable among all active treatment groups (metformin: 2.34 pg/mL, rosiglitazone: 3.06 pg/mL, and combination: 2.39 pg/mL) and were significantly lower than in the placebo group (7.26 pg/mL). Compared with placebo, fasting insulin levels, area under the insulin curve during OGTT, the homeostatic model assessment of insulin sensitivity, and OGTT-derived insulin sensitivity index improved significantly after metformin or combination therapies but not after rosiglitazone. CONCLUSION(S): These findings suggest that insulin-sensitizing drugs increase ovulatory frequency and ameliorate hyperandrogenemia, even in nonobese women with PCOS who appear to have normal insulin sensitivity. 相似文献
983.
Leflunomide-associated pancytopenia with or without methotrexate 总被引:1,自引:0,他引:1
OBJECTIVE: To report 18 cases of pancytopenia associated with leflunomide use in Australia, 5 of which were treated at Princess Alexandra Hospital, Brisbane. case summaries: Leflunomide was used in the treatment of rheumatoid arthritis in 17 of 18 patients; the other patient was diagnosed with systemic lupus erythematosus. Median age was 65.5 years (range 18-79), and 15 of the patients were female. Fourteen patients were on combined treatment with methotrexate. Pancytopenia was typically severe, requiring hospital admission, withdrawal of the immunosuppressant(s), intensive supportive therapy, and treatment of neutropenic sepsis. Five patients died, 4 of whom were receiving concomitant methotrexate. Time to onset of pancytopenia ranged from 11 days to 4 years (median 4 mo). In one case in which the patient had been stable while receiving leflunomide, methotrexate, and hydroxychloroquine for 4 years, fatal pancytopenia was triggered by acute renal failure secondary to dehydration and use of nonsteroidal antiinflammatory drugs. The Naranjo probability scale suggested a probable causal association in 5 cases and possible association in the remainder. DISCUSSION: Leflunomide, indicated for treatment of active rheumatoid arthritis, inhibits pyrimidine synthesis in lymphocytes and other rapidly dividing cells and may rarely be associated with life-threatening pancytopenia. Combination therapy with methotrexate may increase the risk. Time to onset is variable, and clinicians should remain vigilant, particularly when there is a change in the patient's baseline health status. CONCLUSIONS: The risk of pancytopenia during leflunomide therapy appears to be increased when the drug is combined with methotrexate and in older patients. Onset may be delayed, and ongoing monitoring of blood counts is essential. 相似文献
984.
Voskova D Schoch C Schnittger S Hiddemann W Haferlach T Kern W 《Cytometry. Part B, Clinical cytometry》2004,62(1):25-38
BACKGROUND: Multiparameter flow cytometry is increasingly used to monitor minimal residual disease in patients with acute myeloid leukemia to identify leukemic cells by leukemia-associated aberrant immunophenotypes (LAIPs). Changes in LAIPs during the course of the disease may be a limitation for this approach. METHODS: We analyzed 49 patients at diagnosis and relapse by flow cytometry, cytomorphology, cytogenetics, and molecular genetics. RESULTS: In 37 patients (76%), at least one LAIP detectable at diagnosis was present at relapse; in 12 patients (24%), none of the original LAIPs were present in at least 1% of bone marrow cells. Three groups were identified: no change in LAIPs, partial changes in LAIPs, and complete change in LAIPs. There were significant differences across these groups with regard to changes in cytomorphology (11%, 40%, and 58% of all cases, respectively; P = 0.007), cytogenetics (15%, 20%, and 25%; not significant), and molecular genetics (18%, 0, and 86%; P = 0.002). CONCLUSIONS: These data indicate that, in a subset of patients with acute myeloid leukemia, the disease is biologically different at relapse; therefore, monitoring of minimal residual disease is difficult to accomplish. In most patients with acute myeloid leukemia, multiparameter flow cytometry may be used to monitor minimal residual disease. 相似文献
985.
Hüneke R Zitzelsberger D Fassl J Jüngling E Brose S Buhre W Rossaint R Lückhoff A 《Anesthesiology》2004,101(2):409-416
BACKGROUND: Cardiac L-type calcium currents (ICa,L) are affected by volatile anesthetics, possibly contributing to their side effects. Actions of anesthetics on ion channels are usually studied in vitro at room temperature. However, the solubility of anesthetic gases as well as ICa,L are markedly sensitive to the study temperature. Therefore, temperature-dependent effects of halothane and sevoflurane on cardiac ICa,L were analyzed. METHODS: ICa,L were studied at 21 degrees C and 36 degrees C with the patch clamp technique in isolated human atrial cardiomyocytes. Concentrations of anesthetics brought into solution by gassing at both temperatures were determined with gas chromatography. RESULTS: The aqueous concentrations of halothane and sevoflurane were linearly related to their concentration in the gas phase (1 to 3 minimum alveolar concentration [MAC]). At 21 degrees C, the slope of this relation was 0.52 and 0.12 mm/vol % for halothane and sevoflurane, respectively, and decreased at 36 degrees C to 0.29 and 0.09 mm/vol %, respectively. ICa,L displayed significantly higher current amplitudes at 36 degrees C than at 21 degrees C and significantly accelerated time-dependent inactivation. Halothane (1-2 MAC) and sevoflurane (1-3 MAC) evoked stronger inhibitions of ICa,L at 21 degrees C than at 36 degrees C. In spite of different temperature-dependent current amplitudes, the fractional (percent) inhibition of ICa,L showed the same linear relationship to the concentrations of halothane and sevoflurane in the bath medium at both temperatures, as revealed from present and previous experiments. CONCLUSIONS: Inhibition of ICa,L by halothane and sevoflurane is determined by the aqueous concentration of the anesthetics, independently of the temperature. Increased solubility may explain the stronger effects of the anesthetics at lower temperatures. 相似文献
986.
A 47-yr-old man with history of complex regional pain syndrome type 1 underwent an IV Bier block with a mixture of lidocaine and clonidine. The tourniquet was deflated after 60 min, and approximately 10 min later he presented with complex partial seizures. The possible mechanisms for this are discussed, and the effects of clonidine, lidocaine, and the mixture of both are reviewed, as are four additional published cases reporting seizures after the administration of clonidine. 相似文献
987.
Canavese C Bergamo D Ciccone G Longo F Fop F Thea A Martina G Piga A 《Kidney international》2004,65(3):1091-1098
BACKGROUND: Guidelines for treating anemia in dialysis patients accept, as high-end range of serum ferritin useful to optimize erythropoietin therapy, values high as 500 to 900 microg/L, on the hypothesis that ferritin might be not representative of iron overload. METHODS: A superconducting quantum interference device (SQUID) was used to make direct noninvasive magnetic measurements of nonheme hepatic iron content in 40 dialysis patients treated with intravenous iron, and liver iron content was compared with biochemical markers of iron status. RESULTS: Only 12/40 (30%) patients showed normal hepatic iron content (SQUID <400 microg/g), while 32.5% had mild (400 to 1000 microg/g) and 37.5% severe (>1000 microg/g) iron overload, although 28/40 patients (70%) had serum ferritin below 500 microg/L. Among many parameters, hepatic iron content was only correlated with ferritin (r= 0.324, P= 0.04). The receiver operating characteristic (ROC) analysis showed the best specificity/sensitivity ratio to identify iron overload for ferritin >340 microg/L (W = 0.716). Multivariate logistic regression analysis demonstrated that an increase in serum ferritin of 100 microg/L and female gender were independent variables associated with moderate to severe hepatic iron overload: OR 1.71 (95% CI 1.10 to 2.67) and OR 10.68 (95% CI 1.81 to 63.15), respectively. CONCLUSION: Hepatic iron overload is frequent in dialysis patients with ferritin below currently proposed high-end ranges, and the diagnostic power of ferritin in indicating true iron stores is better than presumed. Safety concerns should prompt a reevaluation of acceptable iron parameters, focusing on potential gender-specific differences, to avoid potentially harmful iron overload in a majority of dialysis patients, mainly females. 相似文献
988.
Artenie A Artenie R Ungureanu D Botnariu G Anisies E Ionescu SD Cosovanu A 《Revista medico-chirurgical?? a Societ????ii de Medici ??i Naturali??ti din Ia??i》2004,108(3):503-508
It is known that high sanguin levels of cholesterol and LDL-cholesterol (LDLc) have an important role in the pathogenesis of atherosclerosis. The treatment of hypercholesterolemia with statins and/or with fibrates have had beneficial effects on coronary heart disease and on other localization of atherosclerosis. The decreased of cholesterol and LDL-cholesterol is the most important effect of this treatment. The epidemiological studies have revealed that the treatment with statins and/or with fibrates produce an increase of HDL-cholesterol (HDLc), which is also very important in the regression of atherosclerosis. We tried in this review to explain the mechanisms of the increase of HDL-cholesterol, in concordance with the data from literature. 相似文献
989.
This article presents a numerical study of the electroporation process of spherical cells suspended in an electrolyte solution, using the equivalent circuit method (ECM) for field calculation proposed by Ramos et al. A model for the electric conductance of the cell membrane derived from the analytical and experimental results obtained by Glaser et al. for planar lipidic membranes was applied. The influence of the cell concentration and membrane properties (described in the model) on the membrane current, membrane potential, and dependence of the electrolyte conductivity on the applied electric field was studied. These results clarify the electric events connected with the pore opening process and allow the planning of experimental approaches to study reversible membrane rupture in real cells. 相似文献
990.
Walz MK Peitgen K Diesing D Petersenn S Janssen OE Philipp T Metz KA Mann K Schmid KW Neumann HP 《World journal of surgery》2004,28(12):1323-1329
The retroperitoneoscopic approach is a standardized operative procedure for primary adrenal gland tumors. It allows direct access with a detailed view of the adrenal gland. Thereby, a clear differentiation between normal and neoplastic adrenal tissue is often possible, which permits a planned partial resection of the gland in selected cases. Between July 1994 and November 2003 325 posterior retroperitoneoscopic adrenalectomies were performed for primary benign adrenal gland tumors (106 Conns adenomas, 83 pheochromocytomas, 76 Cushings adenomas, 60 nonfunctioning tumors; size: 2.8 ± 1.5 cm; site: 160 right, 165 left) in 318 patients (122 M, 196 F, age: 49.0 ± 14.3 years). In 96 patients 100 tumors were removed by partial adrenalectomy (30 Conns adenomas, 33 pheochromocytomas, 20 Cushings adenomas, 17 nonfunctioning tumors; site: 61 right, 59 left) maintaining tumor-free parts of the adrenal gland. Of this group, 15 patients suffered from bilateral adrenal neoplastic diseases. During the same period, 225 total adrenalectomies (76 Conns adenomas, 50 pheochromocytomas, 56 Cushings adenomas, 34 nonfunctioning tumors; site: 109 right, 116 left) were performed in 224 patients. There was no mortality. Major complications were seen in 1.8%, minor complications in 14.5%. Three conversions were necessary to an open or a laparoscopic approach (2 patients and 1 patient, respectively). There are no differences between the two groups (total versus partial adrenalectomy) with regard to tumor size (2.8 ± 1.6 cm versus 2.8 ± 1.5 cm), operating time (80 ± 44 minutes versus 79 ± 42 minutes), and blood loss (33 ± 71 ml versus 29 ± 31 ml). In all patients with partial adrenalectomy, biochemical healing was proven. Fourteen of 15 patients with bilateral diseases had preservation of adrenocortical function. After a mean follow up of 51 months (range: 7–120 months) local recurrence or relapse of the initial diseases was noticed in 6 patients after total adrenalectomy: in 4 patients with Conns syndrome and bilateral hyperplasia, and in 2 patients with malignant pheochromocytoma and adrenocortical carcinoma, respectively. Our data demonstrate that partial adrenalectomy is a safe procedure not only perioperatively but also in the long-term follow-up.This article was presented at the International Association of Endocrine Surgeons meeting, Uppsala, Sweden, June 14–17, 2004. 相似文献