全文获取类型
收费全文 | 9411篇 |
免费 | 538篇 |
国内免费 | 39篇 |
专业分类
耳鼻咽喉 | 142篇 |
儿科学 | 210篇 |
妇产科学 | 166篇 |
基础医学 | 1411篇 |
口腔科学 | 825篇 |
临床医学 | 786篇 |
内科学 | 1860篇 |
皮肤病学 | 247篇 |
神经病学 | 777篇 |
特种医学 | 165篇 |
外科学 | 1148篇 |
综合类 | 45篇 |
一般理论 | 4篇 |
预防医学 | 967篇 |
眼科学 | 150篇 |
药学 | 673篇 |
中国医学 | 92篇 |
肿瘤学 | 320篇 |
出版年
2023年 | 102篇 |
2022年 | 188篇 |
2021年 | 335篇 |
2020年 | 205篇 |
2019年 | 290篇 |
2018年 | 362篇 |
2017年 | 236篇 |
2016年 | 279篇 |
2015年 | 316篇 |
2014年 | 408篇 |
2013年 | 485篇 |
2012年 | 752篇 |
2011年 | 828篇 |
2010年 | 413篇 |
2009年 | 355篇 |
2008年 | 605篇 |
2007年 | 603篇 |
2006年 | 529篇 |
2005年 | 447篇 |
2004年 | 394篇 |
2003年 | 349篇 |
2002年 | 318篇 |
2001年 | 158篇 |
2000年 | 132篇 |
1999年 | 134篇 |
1998年 | 54篇 |
1997年 | 39篇 |
1996年 | 34篇 |
1995年 | 35篇 |
1994年 | 17篇 |
1993年 | 20篇 |
1992年 | 50篇 |
1991年 | 59篇 |
1990年 | 42篇 |
1989年 | 45篇 |
1988年 | 49篇 |
1987年 | 30篇 |
1986年 | 22篇 |
1985年 | 23篇 |
1984年 | 18篇 |
1983年 | 15篇 |
1982年 | 12篇 |
1980年 | 19篇 |
1979年 | 16篇 |
1975年 | 10篇 |
1974年 | 17篇 |
1973年 | 15篇 |
1970年 | 14篇 |
1967年 | 12篇 |
1965年 | 10篇 |
排序方式: 共有9988条查询结果,搜索用时 15 毫秒
81.
Eline Lima Borges Gilmara Lopes Amorim Marina Barcelos de Miranda Flaviano dos Santos Martins Antnio Carlos Martins Guedes Kinulpe Honorato Sampaio Josimare Aparecida Otoni Spira Lucíola da Silva Barcelos 《Acta cirúrgica brasileira / Sociedade Brasileira para Desenvolvimento Pesquisa em Cirurgia》2022,37(3)
82.
Trichodermamides A and B,cytotoxic modified dipeptides from the marine-derived fungus Trichoderma virens 总被引:4,自引:0,他引:4
Garo E Starks CM Jensen PR Fenical W Lobkovsky E Clardy J 《Journal of natural products》2003,66(3):423-426
Trichodermamides A (1) and B (2), two modified dipeptides, have been isolated from cultures of the marine-derived fungus Trichoderma virens. The trichodermamides possess a rare cyclic O-alkyl-oxime functionality incorporated into a six-membered ring. The structure of trichodermamide B was established by X-ray diffraction analysis, while the structure assignment of trichodermamide A, and determination of the absolute stereochemistry, was accomplished by spectral and chemical methods. Trichodermamide B displayed significant in vitro cytotoxicity against HCT-116 human colon carcinoma with an IC(50) of 0.32 microg/mL. 相似文献
83.
Rigaudière Florence Nasser Hala Pichard-Oumlil Samia Delouvrier Eliane Lopez-Hernandez Elisa Milani Paolo Auvin Stéphane Delanoë Catherine 《Documenta ophthalmologica. Advances in ophthalmology》2021,143(1):99-106
Documenta Ophthalmologica - Neuronal ceroid lipofuscinoses (CLN) are neurodegenerative disorders among the most frequent, inherited as an autosomal recessive trait. Affected patients can present... 相似文献
84.
Andr Luca Araujo de Sousa Wanderson Carvalho de Almeida Jean de Pinho Mendes Victor Angelo Martins Montalli Antonione Santos Bezerra Pinto 《Acta stomatologica Croatica》2022,56(2):176
The Melanotic Neuroectodermal Tumor of Infancy (MNTI) is an asymptomatic, pigmented neoplasm characterized by a fast and locally aggressive growth along with a rare tissue formation. In the diagnostic process, the use of imaging exams can suggest a local destruction suggestive of malignancy, a sign of bone remodeling and expansion. Therefore, as any early diagnosis minimizes risks and improves the prognosis of treatment for the patient, the aim of this study was, based on a clinical case report, to corroborate the use of histopathological analysis associated with immunohistochemistry. Thus, we conclude that the immunohistochemical exam is of great importance for a better complementation of the MNTI diagnosis process. In addition, it can reveal signs of possible aggressive growth. 相似文献
85.
Daniela N Amora Ticiana M Sousa Alice M C Martins Paulo S F Barbosa Marta R Magalh?es Marcus H Toyama Manassés C Fonteles Dalgimar B de Menezes Helena S A Monteiro 《Toxicon》2006,47(3):260-264
Ophidian accidents caused by the subspecies Crotalus durissus are responsible for high morbity and mortality rates. Acute renal failure is a common complication observed in these accidents. The aim of the present study was to investigate the renal effects promoted by the venom of C. d. collilineatus and its fractions, crotoxin and phospholipase A2. C. d. collilineatus (Cdc; 30 microg mL(-1)), crotoxin (CTX; 10 microg mL(-1)) and phospholipase A2 (PLA2; 10 microg mL(-1)) were tested in isolated rat kidney. The first 30 min of each experiment were used as an internal control and Cdc or its fractions, CTX and PLA2 were added to the system after this period. All experiments lasted 120 min. The venom of Cdc decreased perfusion pressure (PP; control120 = 110.3 +/- 3.69 mmHg; Cdc120 = 96.7+/-8.1 mmHg), renal vascular resistance (RVR; control120 = 6.42+/-0.78 mmHg mL g(-1) min(-1); Cdc120 = 4.8+/-0.56 mmHg/mL g(-1) min(-1)), urinary flow (UF; control120 = 0.19+/-0.03 mL g(-1) min(-1); Cdc120 = 0.12 +/- 0.01 mL g(-1) min(-1)), and glomerular filtration rate (GFR; control120 = 0.79 +/- 0.07 mL g(-1) min(-1); Cdc120 = 0.53 +/- 0.09 mL g(-1) min(-1)), but had no effect on the percent of sodium tubular transport (%TNa+), percent of chloride tubular transport (%TK+) and percent of potassium tubular transport (%TCl-). CTX and PLA2 reduced the GFR, while UF, PP and RVR remained stable during the full 120 min of perfusion. Crotoxin administration also diminished the %TK+ (control120 = 69.94 +/- 6.49; CTX120 = 33.28 +/- 4.78) and %TCl- (control120 = 79.53 +/- 2.67; CTX120 = 64.62 +/- 6.93). PLA2 reduced the %TK+, but exerted no effect on the %TNa+ or on that of TCl-. In conclusion, the C. d. collilineatus venom altered the renal functional parameters evaluated. We suggest that crotoxin and phospholipase A2 were involved in this process, since the renal effects observed would be due to the synergistic action of the components of the venom. 相似文献
86.
Elma Izze da Silva Magalhes Bianca Rodrigues de Oliveira Lívia Carolina Sobrinho Rudakoff Vitria Abreu de Carvalho Poliana Cristina de Almeida Fonseca Viola Soraia Pinheiro Machado Arruda Carolina Abreu de Carvalho Carla Cristine Nascimento da Silva Coelho Maylla Luanna Barbosa Martins Bragana Heloisa Bettiol Marco Antnio Barbieri Viviane Cunha Cardoso Alcione Miranda dos Santos Renata Bertazzi Levy Antnio Augusto Moura da Silva 《Nutrients》2022,14(15)
Longitudinal studies evaluating the relationship between UPF consumption and the incidence of Metabolic Syndrome (MetS) and its components are still scarce. This study aimed to evaluate the effect of UPF consumption on the incidence of MetS and its components in adults. A prospective study was conducted with 896 participants from the 1978/79 Ribeirão Preto cohort, São Paulo, Brazil. UPF consumption was evaluated in %kcal and %g at ages 23–25 years. Incidence of MetS and its components were estimated at ages 37–39 years, according to the Joint Interim Statement criteria. Poisson regression was used to assess associations, and interactions with sex were investigated. UPF consumption had no association with MetS (%kcal Adjusted PR: 1.00; 95% CI: 0.99–1.01; %g Adjusted PR: 1.00; 95% CI: 0.99–1.01). However, women with higher UPF consumption, in %kcal and %g, had a higher risk of abdominal obesity (%kcal: p = 0.030; %g: p = 0.003); and women with higher UPF consumption, in %g, had a higher risk of low HDL-cholesterol (p = 0.041). For the other components of MetS, no significant associations were observed in either sex. These findings suggest evidence of no association between UPF consumption and MetS; however, consumption of UPF was associated with increased WC and low HDL-c, but only in women. 相似文献
87.
José?Rodrigues?PereiraEmail author Sandro?J?Martins Sueli?M?Nikaedo Flora?K?Ikari 《BMC cancer》2004,4(1):69
Background
Although modest improvements in the survival of patients with non-small cell lung cancer (NSCLC) can be achieved with cisplatin-based chemotherapy (CT), its value is disputed in the geriatric setting. In this study, we evaluate the feasibility of vinorelbine/cisplatin CT for elderly NSCLC patients. 相似文献88.
Moraes Tde M Rodrigues CM Kushima H Bauab TM Villegas W Pellizzon CH Brito AR Hiruma-Lima CA 《Journal of ethnopharmacology》2008,120(2):161-168
Ethnopharmacological relevance
Mangaba (Hancornia speciosa Gomez) is a medicinal plant frequently cited in ethnopharmacological inventories of the central region of Brazil against gastrointestinal disorders such as diarrhoea, ulcer, gastritis and stomachache.Aim of the study
The hydroalcoholic extract (HE) and infusion (BI) of Hancornia speciosa bark were investigated for their ability to prevent and heal rodent gastric ulcer.Materials and methods
The preventive and healing action of both preparations of Hancornia speciosa were evaluated in experimental models in rodents that simulated this disease in human gastric mucosa.Results
BI did not exert gastroprotective effect, in contrast to HE (500 mg/kg, p.o.) that decreased (p < 0.05) the severity of gastric damage induced by HCl/ethanol (52%), indomethacin/bethanechol (51%), stress (52%) or pylorus ligature experiments (54%). HE increased (p < 0.05) the pH and decreased acid output of gastric juice. This extract promoted increase of mucus amount (3.62 mg/wt. tissue vs. 5.81 mg/wt. tissue), healing action (67%) and displayed anti-Helicobacter pylori effect.Conclusions
The antiulcer action of Hancornia speciosa resulted in increase of gastric mucus formation and antioxidant properties of polymeric proanthocyanidins present in the bark composition of this medicinal plant. 相似文献89.
Paulo A Martins S Branco P Dias T Borges C Rodrigues AI Costa Mdo C Teixeira A Mota-Filipe H 《Phytotherapy research : PTR》2008,22(4):539-543
The effect of an aqueous extract of Pterospartum tridentatum on the blood glucose levels of normal Wistar rats was investigated in a situation of oral glucose challenge. The extract at 300 mg/kg showed an antihyperglycaemic effect in the first 30 min after glucose challenge but then the blood glucose levels rose above those of the control group, indicating the presence of compounds with different effects on glucose tolerance. Nine compounds of isoflavone and flavonol skeletons were identified in the extract by HPLC-ESI-MS(n), four of them being identified for the first time in this species. The isoflavone sissotrin and the flavonol derivative, isoquercitrin, were selected for the oral glucose tolerance test. Isoquercitrin (100 mg/kg) showed time-dependent antihyperglycaemic activity by delaying the post-oral glucose load glycaemic peak at 30 min, as did the sodium-dependent glucose transporter inhibitor phloridzin (100 mg/kg). In contrast, sissotrin (100 mg/kg) showed an opposite effect, impairing glucose tolerance. In conclusion, these preliminary results indicate that the effect of the extract on blood glucose may be either antihyperglycaemic or hyperglycaemic. Additionally, as far as is known, these are the first in vivo results on the acute antihyperglycaemic potential of isoquercitrin. 相似文献
90.
Cabrita S Rodrigues H Abreu R Martins M Teixeira L Marques C Mota F de Oliveira CF 《European journal of gynaecological oncology》2008,29(2):135-137
PURPOSE OF INVESTIGATION: Magnetic resonance imaging (MRI) has emerged as an important imaging modality in the evaluation of the extension of endometrial carcinoma which is essential in planning treatment and predicting prognosis. This study aimed to assess the value of MRI in the preoperative staging of endometrial carcinoma. METHODS: We included in this study 162 patients with a histological diagnosis of endometrial carcinoma who underwent MRI pelvic imaging and surgical staging. MRI images were compared with pathological findings to measure MRI's sensitivity, specificity, positive and negative predictive values and diagnostic accuracy in what concerns myometrial, cervical and lymph node invasion. RESULTS: MRI differentiation of deep myometrial invasion from superficial disease agreed with pathological findings in 77% of cases, with a sensitivity of 83%, a specificity of 72% and a diagnostic accuracy of 77%. Concerning cervical invasion, MRI had a sensitivity, specificity and diagnostic accuracy of 42%, 92%, 81% respectively. In assessing lymph node invasion, MRI presented a sensitivity of just 17%, a specificity of 99% and a diagnostic accuracy of 89%. CONCLUSION: Our study confirmed the high accuracy of MRI imaging in assessing myometrial and cervical invasion in endometrial carcinoma. When evaluating lymph node invasion, micrometastases are responsible for the low sensitivy of MRI. 相似文献