全文获取类型
收费全文 | 6695篇 |
免费 | 544篇 |
国内免费 | 30篇 |
专业分类
耳鼻咽喉 | 110篇 |
儿科学 | 180篇 |
妇产科学 | 164篇 |
基础医学 | 777篇 |
口腔科学 | 157篇 |
临床医学 | 579篇 |
内科学 | 1781篇 |
皮肤病学 | 264篇 |
神经病学 | 520篇 |
特种医学 | 138篇 |
外科学 | 899篇 |
综合类 | 23篇 |
一般理论 | 1篇 |
预防医学 | 674篇 |
眼科学 | 131篇 |
药学 | 366篇 |
中国医学 | 20篇 |
肿瘤学 | 485篇 |
出版年
2024年 | 11篇 |
2023年 | 95篇 |
2022年 | 139篇 |
2021年 | 481篇 |
2020年 | 202篇 |
2019年 | 451篇 |
2018年 | 582篇 |
2017年 | 296篇 |
2016年 | 297篇 |
2015年 | 294篇 |
2014年 | 399篇 |
2013年 | 612篇 |
2012年 | 696篇 |
2011年 | 690篇 |
2010年 | 510篇 |
2009年 | 352篇 |
2008年 | 207篇 |
2007年 | 138篇 |
2006年 | 171篇 |
2005年 | 119篇 |
2004年 | 102篇 |
2003年 | 80篇 |
2002年 | 71篇 |
2001年 | 31篇 |
2000年 | 26篇 |
1999年 | 25篇 |
1998年 | 29篇 |
1997年 | 23篇 |
1996年 | 17篇 |
1995年 | 7篇 |
1994年 | 8篇 |
1993年 | 8篇 |
1992年 | 4篇 |
1991年 | 5篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1986年 | 5篇 |
1984年 | 4篇 |
1981年 | 3篇 |
1980年 | 4篇 |
1978年 | 6篇 |
1976年 | 4篇 |
1956年 | 2篇 |
1940年 | 2篇 |
1939年 | 2篇 |
1933年 | 3篇 |
1924年 | 2篇 |
1864年 | 3篇 |
1863年 | 2篇 |
1859年 | 2篇 |
排序方式: 共有7269条查询结果,搜索用时 31 毫秒
71.
72.
Gábor RÉPÁssy Csaba Forster-HorvÁth Attila JuhÁsz Róza ÁDÁny Anna TamÁssy József TÍmÁr 《Pathology oncology research : POR》1998,4(1):14-21
Twelve laryngeal squamous cell carcinoma cases (7 laryngeal and 5 hypopharyngeal cancer; 15 samples) were analysed by immunohistochemistry
for the expression of invasion markers CD44v6/v3, NM23 and matrix metalloproteinase, MMP2. The laryngeal epithelium showed
CD44v6+v3+NM23- /MMP2- phenotype. When tumors were grouped into TNM categories the phenotype of the T2 and T3 tumors was similar, characterised
by decreased CD44v3+ and lack of MMP2 expressions. Meanwhile the NM23 expression was more frequent in T3 tumors. In T4 stage the frequency of
NM23 and MMP2 positive cases increased (5/6 and 4/6, respectively) but there was no correlation with the appearence of lymph
node metastasis. Comparison of the phenotype of laryngeal and hypopharyngeal tumors, irrespective of the TNM stages, revealed
characteristic differences: T2 stage laryngeal tumors showed decreased CD44v3 and occasional NM23 and MMP2 positivity, while
in T3 stage these tumors were characterised by increased frequency of NM23 positivity. The phenotype of the hypopharyngeal
tumors was significantly different with a high frequency of MMP2 positive cases (5/6) and NM23+1ow CD44v3+ phenotype. The sharp differences in the phenotypes of laryngeal and hypopharyngeal carcinomas were connected to the differences
in their invasive capacity unlike to the size of the tumors, since the T4 stage hypopharyngeal tumors had a significantly
smaller size than laryngeal ones, even at lower stages.
This work was supported by the Hungarian Ministry of Welfare: ETT No: T-11-100/93 相似文献
73.
Joseph OngrÁdi Steven Specter Attila HorvÁth Herman Friedman 《Pathology oncology research : POR》1998,4(3):191-199
Both marijuana and retroviruses impair natural killer (NK) cell functions, but no data on their simulataneous effects are
available. Similarities to human AIDS induced by Friend leukemia complex (FLO and its helper Rowson-Parr virus (RPV) provides
a mouse model to study drug-virus action. Leukemia susceptible BALB/c and resistant C57BL/6 mice were infected, then at time
intervals their nylon wool-separated splenocytes were exposed to tetrahydrocannabinol (THC) for 3h. Natural killer cell activity
against Yac-1 cells was assayed by 51Cr-release for 4 and 18h. Recovery of splenocytes was found to be suppressed by FLC,
but in BALB/c only by RPV. After a transient enhancement in C57BL/6 by FLC, NK cell activity of both mice became suppressed
early (2 to 4 days), normalized subsequently and enhanced late (11 to 14 days) postinfection. A moderate increase in BALB/c,
no change in C57BL/6 were induced by low (1-2.5 g/ml) THC doses. NK cell activity of BALB/c became suppressed exponentially
by higher (5-10 g/ ml) THC doses in 18h as compared to 4h assays, while its proportional and moderate impairment was seen
in C57BL/6. The magnitude of NK cell activity of infected mice was determined by THC: enhancement or impairment followed those
of untreated, infected counterparts on the level of THC-treated cells. Low doses hardly, high doses additively influenced
NK cells of infected BALB/c. THC slightly affected very early and late enhancement in NK cell activity of FLC infected C57BL/6,
but augmented RPV induced suppression late in 18h assays. Genetic factors similar to endotoxin resistance, altered cytokine
profile might determine these effects. Similar phenomena in humans might result in earlier manifestation of AIDS. 相似文献
74.
Vidal-Sanz M Lafuente M Sobrado-Calvo P Selles-Navarro I Rodriguez E Mayor-Torroglosa S Villegas-Perez MP 《Neurotoxicity research》2000,2(2-3):215-227
In adult Sprague-Dawley rats, retinal ganglion cell survival was investigated after intraorbital optic nerve section and after transient ischemia of the retina induced by elevation of the intraocular pressure or by selective ligature of the ophthalmic vessels. The thickness of the inner nuclear and inner plexiform layers was also assessed after transient periods (120 min) of retinal ischemia induced by selective ligature of the ophthalmic vessels. In addition, we have also investigated the neuroprotective effects of different substances in these paradigms. The intraocular injection of brain-derived neurotrophic factor increased RGC survival after retinal ischemia induced by elevation of the intraocular pressure or by selective ligature of the ophthalmic vessels. The caspase-inhibitor Z-DEVD increased retinal ganglion cell survival after optic nerve section and also after 90 min of retinal ischemia induced by selective ligature of the ophthalmic vessels. The peptide Bcl-2 did not increase retinal ganglion cell survival after optic nerve section but increased retinal ganglion cell survival after 60 or 90 min of retinal ischemia induced by selective ligature of the ophthalmic vessels. Finally, BDNF, nifedipine, naloxone and bcl-2 prevented in part the decrease in thickness of the inner nuclear layer and inner plexiform layer induced by selective ligature of the ophthalmic vessels. Our results suggest that retinal ganglion cell loss induced by different types of injury, may be prevented by substances with neuroprotective effects, by altering steps of the cascade of events leading to cell death. 相似文献
75.
Carlos García-Girón Andrés García Palomo Carmen Alonso López Ángel León Carbonero Miguel Méndez Urena Encarna Adróver Cebrián Ramón Barceló Galíndez Mónica Arroyo Yustos José Álvarez Gallego 《Clinical & translational oncology》2005,7(6):244-249
Introduction This phase II study investigated the anti-tumour activity and toxicity of CPT-11 (250 mg/m2 i.v. infusion over 60 minutes)
administered every 2 weeks as second-line chemotherapy in patients with advanced colorectal cancer (CRC).
Material and methods Patients (n=63) with histology diagnosis of advanced CRC and proven resistance to previous fluoropyrimidine therapy were enrolled.
Results A total of 510 CPT-11 cycles were administered, with a mean of 8 cycles per patient (range: 1–32). The median relative dose
intensity was 93%. Partial response (PR) was obtained in 11 patients (17.5%; 95%CI: 8.1%–26.7%) and 29 patients (46.0%) showed
stable disease (clinical benefit of 63.5%). The median duration of response was 6.8 months (95%CI: 6.1–7.5 months), median
survival was 8.8 months (95%CI: 6.3–11.5 months) and median time to disease progression was 4.5 months (95%CI: 3.9–5.0 months).
Overall, this schedule of CPT-11 chemotherapy was well tolerated by the patient. Neutropenia was the most frequent grade 3/4
haematological toxicity (20.6% of patients and 4.1% of cycles). Neutropenia with concurrent fever or infection occurred in
7 patients (11.1%). Late onset diarrhoea was the most frequent grade 3/4 non-haematological toxicity (19.0% of patients and
2.3% of cycles). Other, lower-incidence, toxicities were anaemia, fever, infection, mucositis, nausea and vomiting. There
were no toxic deaths.
Conclusions We found that CPT-11, administered as 250 mg/m2 i.v. infusion over 60 minutes every 2 weeks, was active and well tolerated schedule in the second-line chemotherapy of advanced
CRC patients. This bi-weekly scheme could be used as an alternative to the weekly or the every-three-week schedule as well
as in combined therapies with other chemotherapeutic agents for the treatment of advanced, metastatic, CRC. 相似文献
76.
77.
78.
79.
Over the last years, ambulatory blood pressure monitoring has been introduced into the pediatric population, contributing to a significant increase in the bulk of knowledge of crucial clinically relevant issues. Guidelines have established the currently known conditions where ambulatory blood pressure monitoring is useful and where it will provide additional information in children and adolescents. How common and important the intra-individual differences are within clinical and ambulatory blood pressure is the keystone to the use of ambulatory blood pressure monitoring as a diagnostic tool. By using not only office, but also ambulatory blood pressure, four possible situations arise. Two of these have values in agreement for normotension or hypertension. Two have values that are discrepant. The latter two are known as white coat and masked hypertension. The relationship with hypertension-induced organ damage, the prognostic value and the assessment of treatment goals are key issues of ambulatory blood pressure monitoring. In children, the accurate identification of hypertension at the earliest possible age would, therefore, give health-care providers the opportunity to initiate preventive measures, thereby reducing the chance of developing end-organ damage and its attendant morbidity and mortality. 相似文献
80.