全文获取类型
收费全文 | 381120篇 |
免费 | 33876篇 |
国内免费 | 15372篇 |
专业分类
耳鼻咽喉 | 3579篇 |
儿科学 | 10904篇 |
妇产科学 | 3649篇 |
基础医学 | 57468篇 |
口腔科学 | 9323篇 |
临床医学 | 32374篇 |
内科学 | 57550篇 |
皮肤病学 | 7050篇 |
神经病学 | 25229篇 |
特种医学 | 9363篇 |
外国民族医学 | 155篇 |
外科学 | 48907篇 |
综合类 | 54048篇 |
现状与发展 | 78篇 |
一般理论 | 4篇 |
预防医学 | 12858篇 |
眼科学 | 6019篇 |
药学 | 37498篇 |
131篇 | |
中国医学 | 11863篇 |
肿瘤学 | 42318篇 |
出版年
2024年 | 830篇 |
2023年 | 5729篇 |
2022年 | 11029篇 |
2021年 | 14820篇 |
2020年 | 13225篇 |
2019年 | 12910篇 |
2018年 | 12875篇 |
2017年 | 13471篇 |
2016年 | 13793篇 |
2015年 | 15078篇 |
2014年 | 23958篇 |
2013年 | 25504篇 |
2012年 | 21632篇 |
2011年 | 24751篇 |
2010年 | 20492篇 |
2009年 | 19869篇 |
2008年 | 20097篇 |
2007年 | 19619篇 |
2006年 | 17883篇 |
2005年 | 16103篇 |
2004年 | 13730篇 |
2003年 | 11715篇 |
2002年 | 9374篇 |
2001年 | 8114篇 |
2000年 | 6745篇 |
1999年 | 5974篇 |
1998年 | 5569篇 |
1997年 | 5095篇 |
1996年 | 4635篇 |
1995年 | 4118篇 |
1994年 | 3799篇 |
1993年 | 3096篇 |
1992年 | 2749篇 |
1991年 | 2458篇 |
1990年 | 1958篇 |
1989年 | 1825篇 |
1988年 | 1712篇 |
1987年 | 1412篇 |
1986年 | 1418篇 |
1985年 | 1925篇 |
1984年 | 1729篇 |
1983年 | 1235篇 |
1982年 | 1335篇 |
1981年 | 1100篇 |
1980年 | 957篇 |
1979年 | 782篇 |
1978年 | 542篇 |
1977年 | 432篇 |
1976年 | 393篇 |
1975年 | 207篇 |
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
11.
TOMONORI KATO HIROYOSHI SUZUKI AKIRA KOMIYA TAKASHI IMAMOTO YUKIO NAYA TOYOFUSA TOBE TOMOHIKO ICHIKAWA 《International journal of urology》2006,13(7):915-919
AIM: The clinical significance of the urinary white blood cell (U-WBC) count and serum C-reactive protein (CRP) level was evaluated in an effort to improve the efficiency of prostate biopsies. METHODS: We enrolled 228 consecutive patients with serum prostate-specific antigen (PSA) ranging from 3.0 to 20.0 ng/mL, normal digital rectal examination findings, and who underwent prostate biopsies between January 2001 and August 2004. Of these, 157 patients had histologically confirmed benign prostatic disease and the remaining 71 patients had prostate cancer. Patients with a pretreatment U-WBC count < or =3 or >3/high power field were defined as non-pyuria and pyuria, respectively. The patients were also separated into two groups based on the serum CRP level prior to biopsy. Several clinical factors were compared among these subgroups. RESULTS: Inflammation was histologically detected at rates of 58.1% and 34.1% in the pyuria and non-pyuria groups, respectively (P = 0.0014). The rates of cancer detection were significantly lower in the pyuria, than in the non-pyuria group (P = 0.0384). The cancer detection rates did not significantly differ according to serum CRP levels prior to biopsy. CONCLUSION: The U-WBC count appears to be a reliable indicator of minute prostatic inflammation. The serum PSA level was elevated in patients with asymptomatic prostatitis. Counting U-WBC is a simple, convenient and non-invasive method that should be valuable part of routine urological examinations. 相似文献
12.
Claudia Gedlicka Gudrun Hager Martina Weissenböck Wilhelm Gedlicka Birgit Knerer Johannes Kornfehl Michael Formanek 《Journal of oral pathology & medicine》2006,35(8):472-478
BACKGROUND: 1Alpha,25-dihydroxyvitamin D(3) [1,25(OH)(2) Vitamin D(3)] induces growth inhibition in squamous cell carcinoma (SCC) cell lines of the head and neck by arresting the cells in the G0/G1 phase of the cell cycle, probably due to an enhanced expression of p21, which could be demonstrated in other cell lines (JPPA, SCC9) before. In SCC25, a SCC cell line isolated from tongue, growth inhibition but no overexpression of p21 was detected. The retinoblastoma gene, as a direct target of G1 cyclin-CDK complexes, showed an obvious shift from the hyperphosphorylated to the hypophosphorylated form under 1,25(OH)(2)Vitamin D(3), which indicates that the growth inhibition takes place in the G0/G1 phase. To explore the possible pathway of growth inhibition in SCC25 we investigated other cell cycle inhibitors (p18, p19, p27). METHODS: Synchronized cells were treated with 1,25(OH)(2)Vitamin D(3) over 96 h. The cell cycle status and expression of cell cycle-regulating proteins was determined by fluorescence-activated cell sorting (FACS) and Western blotting. An overexpression of p18 in 1,25(OH)(2)Vitamin D(3) vs. ethanol-treated cells was determined until 30 h in SCC25. No influence was detectable on the expression of p27 and p19. CONCLUSION: One mechanism by which 1,25(OH)(2)Vitamin D(3) controls cell growth might be the upregulation of p21. As p21 was unsusceptible to 1,25(OH)(2)Vitamin D(3) in SCC25, other inhibiting proteins were necessary to be tested. The proven upregulation of p18 seems to be the responsible step for growth inhibition of 1,25(OH)(2)Vitamin D(3) in SCC25. 相似文献
13.
Anne-Catherine Bachoud-Lévi Philippe Hantraye Marc Peschanski 《Movement disorders》2002,17(3):439-444
Intrastriatal transplantation of striatal neuroblasts from human fetuses is a promising approach for treatment of Huntington's disease, on the basis of many experimental animal studies and, most recently, pilot clinical trials. Technically, several issues remain to be resolved (e.g., the precise site of dissection of the fetal tissue; the number and location of the fetal striatal implants; or the use of immunosuppressive therapy), and await larger-scale trials and purposely designed protocols. Further clinical data must also be obtained, and preliminary promising results must be replicated in a patient group large enough to provide conclusive results. It is important to establish (1) the amount of clinical benefit provided to the patient by the grafted cells; (2) the anticipated duration of clinical benefits; and (3) the secondary rate of decline after the benefit of the graft has been overbalanced. Evaluation of these parameters will require very long-term follow-up of the patients involved, over several years after grafting, before the technique can eventually be proposed widely to patients. 相似文献
14.
A. Al Tahan S. Arora A. Alzeer F. Al Tahan T. Malabarey A. Daif 《European journal of neurology》1997,4(1):52-58
The diagnosis of acute disseminated encephalomyelitis (ADEM) is frequently missed or delayed with consequent delay in instituting therapy in the crucial phase of the illness. The role of MRI in the diagnosis of ADEM is well established, however, the value of its early utilization of treatment on the outcome of patients has not been adequately stressed. Three patients with ADEM are described. Delay in the diagnosis of the first was associated with severe sequelae, while in the other two early diagnosis and institution of corticosteroid therapy which was facilitated by MRI, was associated with a better outcome. MRI should be carried out early once the diagosis of ADEM is entertained. 相似文献
15.
Pankaj Hari Anand Srivastava Arun Kumar Gupta Rajendra N. Srivastava 《Pediatric nephrology (Berlin, Germany)》1997,11(4):497-498
Acute renal failure (ARF) developed in a 7-week-old infant due to bilateral candidal bezoars (fungal balls) causing obstruction
at the pelviureteric junction. The baby was born at term with an appropriate birthweight, and had been treated with broad-spectrum
antibiotics for respiratory distress and septicemia during the 1st week of life. Recovery from ARF followed renal decompression
with bilateral nephrostomy tube placement and parenteral administration of amphotericin B and 5-flucytosine.
Received August 21, 1996; received in revised form and accepted January 3, 1997 相似文献
16.
Nawf Sharief Judith E. Kingston Vanessa M. Wright Kate Costeloe 《Pediatric hematology and oncology》1991,8(4):323-327
We describe a familial case of Marfan's syndrome with associated intrathoracic stomach detected during the neonatal period. The patient developed a primitive leukemia at 3 months of age. Acute leukemia in a patient with Marfan's syndrome has not previously been reported. 相似文献
17.
The B cell functional response following ligation of surface(s) lgM is dependent upon the differentiation stage of the populationstudied: cross-linking slgM promotes proliferation of restingtonsillar follicular mantle (FM) B lymphocytes but induces apoptosisin the susceptible Epstein- Barr virus genome-negative Burkittlymphoma (BL) cell line Ramos (Ramos-BL). This study investigateswhether phosphatidylinositol-3-kinase (Pl3-kinase), which hasbeen reported to be intimately involved in the regulation ofcellular growth, plays a role in the regulation of these sig-promoted B cell responses, and uses the selective and irreversibleinhibitor of Pl3-kinase activity, wortmannin (Wm). In Ramos-BLB cells, at 8 h post-treatment, Wm triggers a transient increasein apoptosis of 16 ± 6.9% with a concomitant cellularloss of 16 ± 6.1% from the G1 phase of cell cycle; [3H]thymidineincorporation also decreases by 33 ± 5.0%, from 37,274c.p.m. ± 10% to 25,127 c.p.m. ± 4.0%. Moreover,at 72 h culture, Wm inhibits anti-lgM-induced FM B lymphocytelevels of [3H]thymidine incorporation typically by 47% and triggers80% apoptosis from the G0G1 phase of cell cycle. Ramos-BL Bcells exhibit high basal levels of Pl3-kinase activity, as determinedby immunoprecipitation with antibody to the p85 regulatory subunitof Pl3-kinase and 32P incorporation into phosphatidylinositol,which is not significantly affected by anti-lgM stimulation;by contrast, anti-lgM stimulates significant Pl3-kinase activityover negligible basal levels in FM B lymphocytes. Pre-treatmentwith Wm inhibits Pl3-kinase activity in both cell types. Takentogether these data indicate that in Ramos-BL B cells slgM-triggeredgrowth arrest and apoptosis is Pl3- kinase independent, whereasPl3-kinase activity is critical for slgM-triggered mitogenesisof FM B lymphocytes. Thus Pl3-kinase plays a pivotal role inthe regulation of both normal and neoplastic B lymphocyte progressionthrough the cell cycle, such that if this Pl3-kinase-dependentpathway is inhibited these cells default to apoptosis. 相似文献
18.
Abraham Nudelman Yitschak Binnes Naomi Shmueli-Broide Yael Odessa J. Paul Hieble Anthony C. Sulpizio 《Archiv der Pharmazie》1996,329(3):125-132
Vinylogous (Groups III and V ) and acetylenologous (Group IV ) analogs of the classical β-adrenergic agents — stimulants and blockers — were prepared in order to evaluate the effect of degree of saturation, position of unsaturation and rigidity of the chain linking the aromatic ring and the amino containing functional group on biological activity. Derivatives from Group III , which represent 4-aryl-3-butenyl-2-ol-amine analogs of Group II , retained β1-adrenoceptor antagonist activity albeit substantially less potent (50–200-fold) than that possessed by their aryloxy counterparts. Consistent with the SAR for Group II compounds, substitution at position 2 of the aromatic ring yielded the most potent antagonists ( 5a, 5d, 5g ), with KB's ranging from 73–93 nM while 3,4-dichloro substitution ( 5e ) markedly reduced antagonist potency (KB = 2,400 nM). Agonist activity was also noted for 5b and 5d , suggesting that these compounds may be best classified as partial agonists. Representatives from Groups IV and V were inactive as antagonists at the β1-adrenoceptor confirming the importance of the spatial relationship between the hydroxyl and the amino nitrogen. 相似文献
19.
目的:研究健血升白冲剂对小鼠血液系统的影响。方法:以骨髓细胞计数,白细胞计数和血象为指标,观察健血升白冲剂对正常小鼠和化学及放射损伤小鼠的影响。结果:健血升白冲剂明显增加正常小鼠白细胞计数(P<001),显著改善环磷酰胺诱导小鼠白细胞和骨髓细胞的减少作用(分别为P<005,P<001),并能显著增加60Co放射损伤小鼠骨髓细胞(P<001)和白细胞(P<001)。结论:健血升白冲剂对化学及放射损伤小鼠血液系统有明显的保护及改善作用。是一个有开发价值的药物。 相似文献
20.
BACKGROUND: The responses of mice to the mite allergen Der p 1 have been used to study the mechanisms of allergic sensitization and the development of new types of immunotherapy. Many of the studies require a knowledge of the T cell epitopes, and because Der p 1 is polymorphic, the effect of natural amino acid substitution in the allergen. The intranasal administration of peptides containing T cell epitopes can induce a mucosal tolerance but it is not known if the major activity is limited to stimulatory peptides and if, as found for autoimmunity, some epitopes are not inhibitory. OBJECTIVE: To determine and compare the sequences of Der p 1 which contain stimulatory epitopes for the high responding H-2(b) and H-2(q) mice and the sequences which induce tolerance by intranasal administration of peptides. METHODS: T cell responses of mice immunized with Der p 1 were measured by in vitro T cell stimulation assays so an extensive study of epitope recognition and intranasal tolerance could be made. Synthetic peptides were used to examine the stimulatory and inhibitory ability of all Der p 1 sequences and to map the major H-2(b) epitope in detail. This included the effect of the common polymorphic amino acid 124 substitution found within this epitope. RESULTS: Three and two regions, respectively, were found to contain stimulatory T cell epitopes for H-2(b) and H-2(q) mice. The peptides in these regions were also the most active at inducing intranasal tolerance for the responding haplotype. The correspondence between inhibitory and stimulatory peptides was maintained for the fine mapping of the major H-2(b) epitope. This was found about a core region of 118-126 which was overlapping but separate to a consensus sequence for the binding of endogeneous peptides. Peptides with alanine at the naturally polymorphic residue 124 stimulated and inhibited responses to Der p 1 more effectively, while peptides with the valine 124 variant were immunogenic but poorly cross-reactive. CONCLUSIONS: The intranasal administration of peptides representing each of five epitopes recognized by two strains of mice were able to induce mucosal tolerance and the major tolerizing activity was limited to these epitopes. The position of the core major epitope for C57 mice, which differs from a previously predicted epitope, and its specificity for the natural alanine 124 variant is described. 相似文献