全文获取类型
收费全文 | 8454篇 |
免费 | 682篇 |
国内免费 | 565篇 |
专业分类
耳鼻咽喉 | 39篇 |
儿科学 | 63篇 |
妇产科学 | 30篇 |
基础医学 | 1327篇 |
口腔科学 | 93篇 |
临床医学 | 255篇 |
内科学 | 483篇 |
皮肤病学 | 135篇 |
神经病学 | 230篇 |
特种医学 | 76篇 |
外国民族医学 | 3篇 |
外科学 | 185篇 |
综合类 | 1491篇 |
现状与发展 | 1篇 |
预防医学 | 597篇 |
眼科学 | 94篇 |
药学 | 1882篇 |
中国医学 | 2530篇 |
肿瘤学 | 187篇 |
出版年
2024年 | 24篇 |
2023年 | 80篇 |
2022年 | 216篇 |
2021年 | 294篇 |
2020年 | 240篇 |
2019年 | 201篇 |
2018年 | 231篇 |
2017年 | 294篇 |
2016年 | 328篇 |
2015年 | 352篇 |
2014年 | 578篇 |
2013年 | 720篇 |
2012年 | 655篇 |
2011年 | 711篇 |
2010年 | 537篇 |
2009年 | 434篇 |
2008年 | 457篇 |
2007年 | 452篇 |
2006年 | 352篇 |
2005年 | 312篇 |
2004年 | 255篇 |
2003年 | 218篇 |
2002年 | 227篇 |
2001年 | 155篇 |
2000年 | 118篇 |
1999年 | 124篇 |
1998年 | 123篇 |
1997年 | 105篇 |
1996年 | 89篇 |
1995年 | 75篇 |
1994年 | 86篇 |
1993年 | 62篇 |
1992年 | 62篇 |
1991年 | 49篇 |
1990年 | 42篇 |
1989年 | 47篇 |
1988年 | 46篇 |
1987年 | 34篇 |
1986年 | 35篇 |
1985年 | 55篇 |
1984年 | 49篇 |
1983年 | 41篇 |
1982年 | 39篇 |
1981年 | 24篇 |
1980年 | 25篇 |
1979年 | 14篇 |
1978年 | 10篇 |
1977年 | 7篇 |
1976年 | 6篇 |
1974年 | 4篇 |
排序方式: 共有9701条查询结果,搜索用时 31 毫秒
101.
Projections from the paratrigeminal nucleus and the medullary and spinal dorsal horns to the peribrachial area in the cat 总被引:1,自引:0,他引:1
The projections from the medullary and spinal dorsal horns to the dorsolateral pons were investigated in the cat utilizing both the retrograde and anterograde transport of a wheat germ agglutinin-horseradish peroxidase complex and the retrograde transport of the fluorescent dyes Fast Blue and Nuclear Yellow. After injections of wheat germ agglutinin-horseradish peroxidase into the area surrounding the brachium conjunctivum, numerous neurons were labeled ipsilaterally near levels of the obex in the paratrigeminal nucleus. Such neurons were located in connected pockets of neuropil located within the spinal trigeminal tract and along its medial edge. Most of the neurons labeled in the dorsal horns after such injections were found in lamina I. Those found in the medullary dorsal horn were mostly ipsilateral to the injection while those in the spinal dorsal horn were found bilaterally. Some labeled neurons were also found in lamina V of both the medullary and spinal dorsal horns bilaterally. When the injection was centered in either the medial parabrachial nucleus or the Kolliker-Fuse nucleus, a greater number of neurons were labeled ipsilaterally in lamina V of the medullary dorsal horn. Since neurons in lamina I of the medullary dorsal horn also project to the medial thalamus, fluorescent dyes were used to determine if the same neuron might project to both targets. Fast Blue was first injected into either the peribrachial area or the medial thalamus. After an appropriate period, Nuclear Yellow was injected into that target not injected first with Fast Blue. The injection of Nuclear Yellow was always placed on the side of the brain opposite to the first injection. Both dyes were transported retrogradely and were found in neurons located in lamina I of the medullary dorsal horn. However, no double-labeled neurons were seen. In general those labeled after injections of the medial thalamus were more superficial than those labeled after injections of the dorsolateral pons. The anterograde transport of wheat germ agglutinin-horseradish peroxidase was used to determine the termination of the projections from neurons in the medulary dorsal horn and the cervical spinal cord to the peribrachial area. After injections into these areas a moderate to sparse labeling of the lateral parabrachial nucleus and the Kolliker-Fuse nucleus was seen. It was mostly ipsilateral in cases with injections of the medullary dorsal horn but was bilateral following injections into the cervical enlargement.(ABSTRACT TRUNCATED AT 400 WORDS) 相似文献
102.
R.P. Vertes 《Neuroscience》1984,11(3):651-668
The origins of projections within the medial forebrain bundle from the lower brainstem were examined with the horseradish peroxidase technique. Labeled cells were found in at least 15 lower brainstem nuclei following injections of a conjugate or horseradish peroxidase and wheat germ agglutinin at various levels of the medial forebrain bundle. Dense labeling was observed in the following cell groups (from caudal to rostral): A1 (above the lateral reticular nucleus); A2 (mainly within the nucleus of the solitary tract); a distinct group of cell trailing ventrolaterally from the medial longitudinal fasciculus at the level of the rostral pole of the inferior olive; raphe magnus; nucleus incertus; dorsolateral tegmental nucleus (of Castaldi); locus coeruleus; nucleus subcoeruleus; caudal part of the dorsal (lateral) parabrachial nucleus; and raphe pontis. Distinct but light labeling was seen in raphe pallidus and obscurus, nucleus prepositus hypoglossi, nucleus gigantocellularis pars ventralis, and the ventral (medial) parabrachial nucleus. Sparse labeling was observed throughout the medullary and caudal pontine reticular formation. Several lower brainstem nuclei were found to send strong projections along the medial forebrain bundle to very anterior levels of the forebrain. They were: A1, A2, raphe magnus (rostral part), nucleus incertus, dorsolateral tegmental nucleus, raphe pontis and locus coeruleus. With the exception of the locus coeruleus, attention has only recently been directed to the ascending projections of most of the nuclei mentioned above. Evidence was reviewed indicating that fibers from lower brainstem nuclei with ascending medial forebrain bundle projections distribute to widespread regions of the forebrain.It is concluded from the present findings that several medullary cell groups are capable of exerting a direct effect on the forebrain and that the medial forebrain bundle is the major ascending link between the lower brainstem and the forebrain. 相似文献
103.
Gordon B. Strom Richard N. Boswell Robert L. Jacobs 《The Journal of allergy and clinical immunology》1983,72(1):46-53
Thirty-four patients with a history of immediate hypersensitivity to the sting of the imported fire ant were evaluated in a study designed to compare the diagnostic usefulness of fire ant whole body extract (WBE) preparations with that of fire ant venom (IFAV). Ninety-one percent () of the hypersensitive patients skin tested with IFAV at a maximal concentration of 1:5 × 103, , demonstrated a wheat equal to or greater than the histamine control. Fifty-three percent () of the group were skin test positive to a WBE preparation. When the criteria for a positive skin test were relaxed, 82% of the hypersensitive group could be identified with the IFAWBE. A comparison of skin test results in sensitive patients revealed variability in the sensitivity of the WBE preparations utilized in the study. Leukocyte histamine release demonstrated a dose-response release of histamine with both IFAV and SIWBEa preparations. Specific venom antisera produced in rabbits identified a precipitin line of common identity in a gel-diffusion system containing IFAWBE and IFAV. This finding was verified by the competitive inhibition of IFAWBE with IFAV in a solid-phase radioimmunoassay system. Fire ant WBEs contain venom constituents and are effective diagnostic agents in up to 82% of patients with hypersensitivity to the sting of the imported fire ant. Marked variability in the responsiveness of sensitive patients to different WBE preparations mandates standardization of these diagnostic preparations. 相似文献
104.
L. BAUER C. EBNER R. HIRSCHWEHR B. WÜTHRICH† C. PICHLER‡ R. ERITSCH O. SCHEINER D. KRAFT 《Clinical and experimental allergy》1996,26(10):1161-1170
Background Allergy to celery is often associated with sensitization to birch and/or mugwort pollen. Objective and methods In a multi-centre study, sera from 23 patients suffering from type I allergy to celery and 15 patients with positive celery RAST but wo clinical sensitization were compared. To examine whether cross-reactivity between celery and mugwort pollen iticludes cross-sensitization to birch pollen allergens, we determined cross-reacting structures in birch pollen, mugwort pollen and celery by means of immunoblotting. Inhibition studies were performed by preincubation of sera with extracts of birch pollen, mugwort pollen, and celery. Results We identified three groups of proteins—homologues of Bet v I and birch profilin (Bet v 2) as well asa group of proteins with a molecular range of 46 to 60 kD—displaying IgE-cross-reactivity, which were shared by birch pollen and celery. Two of these groups of allergens (profilin and the 46 to 60 kD proteins) were also present in mugwort pollen. In this paper we demonstrate that most cross-reacting allergens present in mugwort pollen and celery can also be detected in birch pollen extract. Conclusion Therefore we propose, from a serological point of view, to extend the mugwort-celery syndrome to the birch-mugwort-celery syndrome. 相似文献
105.
Donald Barnett Brian A. Baldo Merlin E.H. Howden 《The Journal of allergy and clinical immunology》1983,72(1):61-68
Crude peanut protein fractions from raw and roasted peanuts were examined in the RAST with 10 sera from patients showing clinical peanut sensitivity. The radioactive uptake results, which were generally high, did not reveal any distinguishable pattern. Two commercially available peanut proteins, peanut lectin and phospholipase D, gave poor RAST responses. Three purified peanut proteins, α-arachin, conarachin I, and concanavalin A-reactive glycoprotein, all gave significant RAST results that were generally lower than those obtained with the crude extracts. The extent of RAST inhibition obtained with these materials was inversely related to their abundance in the total peanut protein. Crossed immunoelectrophoresis with extracts from raw and roasted peanut indicated the presence of 22 and 10 anodically migrating antigens, respectively. Sixteen IgE binding antigens were revealed for raw peanut and seven for roasted peanut after incubation with a mixed serum from the 10 patients in crossed radioimmunoelectrophoresis (CRIE) using 125I-labeled anti-IgE. CRIE plates treated with individual serum samples showed that all the patients had specific IgE for the major antigen peak, which has been tentatively identified as α-arachin. This major storage protein of peanut, which is known to be particularly heat resistant, may be of greater clinical significance than its apparently low RAST activity would seem to indicate. 相似文献
106.
目的:探究泽漆水提物对香烟烟雾(CS)所致的慢性阻塞性肺病(COPD)的保护作用及肺组织癌前病变相关蛋白的影响。方法:通过建立CS所致的COPD小鼠模型(60只),随机分为正常组、模型组、阳性药组(地塞米松2 mg·kg-1)及泽漆水提物低、中、高剂量组(1.875、3.75、7.5 g·kg-1)。采用高效液相色谱法(HPLC)测定泽漆水提物中相关成分;动物肺功能仪检测小鼠呼气末期暂停(EEP)、气道阻力(Penh)、50%肺活量呼吸时的呼气流量(EF50)等肺功能指标变化;高通量液相蛋白芯片技术检测小鼠肺泡灌洗液(BALF)中白细胞介素(IL)-2、IL-5、IL-18、IL-17A、IL-27等炎性因子水平变化;苏木素-伊红(HE)染色检测小鼠肺组织的病理变化;比色法测定小鼠肺组织中的丙二醛(MDA)、髓过氧化物酶(MPO)及谷胱甘肽过氧化物酶(GSH-Px)含量变化;实时荧光定量聚合酶链式反应(Real-time PCR)检测肿瘤坏死因子-α(TNF-α)、转化生长因子-β(TGF-β)、基质金属蛋白酶(MMP)-2、MMP-9及MM... 相似文献
107.
The human ileostomy model, widely considered the benchmark for determining in vivo starch digestibility, has disadvantages. The ileorectostomised rat model (IRM) is a possible surrogate but evidence as to its validity is scant. In this preliminary study, the resistant starch (RS) content of test breads made from refined low (LAW-R) and high amylose wheat (HAW-R) flours was established in a randomised cross-over trial involving six human ileostomy participants. Starch digestibility of refined breads and diets made from these flours was then evaluated in ileorectostomised rats using a similar experimental format. Physical performance measures and other data were also collected for the rat model. The amount of RS in the low- and high-amylose breads as measured using the human model was 0.8 ± 0.1 and 6.5 ± 0.3 g/100 g, respectively. The RS level of HAW-R bread determined using ileorectostomised rats was 5.5 ± 0.8 g/100 g, about 15% less than that recorded in the human study, whereas for conventional wheat breads the models produced similar RS values. While offering promise, further validation using a wide variety of starchy food products is needed before the IRM can be considered an acceptable alternative for RS determination. 相似文献
108.
Nicolette W. de Jong Severina Terlouw Frank E. van Boven M.S. van Maaren Marco W.J. Schreurs Dianne B.P.M. van den Berg-Somhorst Diederik Esser Shanna Bastiaan-Net 《Nutrients》2021,13(4)
Approximately 70% of birch pollen allergic patients in Europe experience hypersensitivity reactions to Immunoglobulin E (IgE) cross-reactive food sources. This so-called pollen-food syndrome (PFS) is defined by allergic symptoms elicited promptly by the ingestion of fruits, nuts, or vegetables in these patients. So far, in the literature, less attention has been given to Bet v 1 cross-reactive symptoms caused by pear (Pyrus communis). In the Netherlands, pears are widely consumed. The primary objective of this study was to measure the type and severity of allergic symptoms during pear challenges in birch pollen allergic patients, with a positive history of pear allergy, using two different pear varieties. Fifteen patients were included, skin prick test (SPT), prick-to-prick test (PTP), specific Immunoglobulin E (sIgE), and single-blind oral challenges were performed with two pear (Pyrus communis) varieties: the ‘Cepuna’ (brand name Migo®) and the ‘Conference’ pears. All patients were sensitized to one or both pear varieties. A total of 12 out of 15 participants developed symptoms during the ‘Cepuna’ food challenge and 14/15 reacted during the ‘Conference’ challenge. Challenges with the ‘Cepuna’ pears resulted in less objective symptoms (n = 2) in comparison with challenges with ‘Conference’ pears (n = 7). Although we did not find significance between both varieties in our study, we found a high likelihood of fewer and less severe symptoms during the ‘Cepuna’ challenges. Consequently selected pear sensitized patients can try to consume small doses of the ‘Cepuna’ pear outside the birch pollen season. 相似文献
109.
Alma Martelli Lorenzo Flori Era Gorica Eugenia Piragine Anella Saviano Giuseppe Annunziata Matteo Nicola Dario Di Minno Roberto Ciampaglia Ilenia Calcaterra Francesco Maione Gian Carlo Tenore Ettore Novellino Vincenzo Calderone 《Nutrients》2021,13(5)
Preservation of vascular endothelium integrity and functionality represents an unmet medical need. Indeed, endothelial dysfunction leads to decreased nitric oxide biosynthesis, which is prodromic of hypertension and hypercoagulability. In this panorama, the nutraceutical supplement Taurisolo®, a polyphenolic extract from Aglianico cultivar grape, rich in catechin and procyanidins, was evaluated as a vasoprotective, vasorelaxing, anti-hypertensive and anti-coagulant agent in: cell lines, isolated vessels, in vivo models of chronic hypertension and hypercoagulability, and in clinical tests of endothelial reactivity. Taurisolo® demonstrated to fully protect vascular cell viability from oxidative stimulus at 100 µg/mL and evoke vasorelaxing effects (Emax = 80.6% ± 1.9 and pEC50 = 1.19 ± 0.03) by activation of the Sirtuins-AMPK-pathway. Moreover, Taurisolo®, chronically administered at 20 mg/Kg/die in in vivo experiments, inhibited the onset of cardiac hypertrophy (heart weight/rat weight = 3.96 ± 0.09 vs. 4.30 ± 0.03), hypercoagulability (decrease of fibrinogen vs. control: p < 0.01) and hypertension (mean of Psys: 200 ± 2 vs. control 234 ± 2 mmHg) and improved endothelial function (Emax = 88.9% ± 1.5 vs. control 59.6% ± 3.6; flow-mediated dilation in healthy volunteers after 400 mg twice daily for 8 weeks vs. baseline: p = 0.019). In conclusion, Taurisolo® preserves the vascular function against ox-inflamm-ageing process and the consequent cardiovascular accidents. 相似文献
110.
豚草花粉变应原致过敏性鼻炎豚鼠模型的建立 总被引:3,自引:0,他引:3
为了建立豚草花粉变应原致过敏性鼻炎的实验动物模型,将健康豚鼠42只,随机分为致敏组(n=32)和对照组(n=10).致敏组经腹腔、四肢皮下注射豚草花粉变应原免疫4周后,鼻腔滴入豚草花粉变应原;对照组以生理盐水代替变应原.结果致敏组28只出现鼻痒、喷嚏、流清涕等过敏性鼻炎的临床体征(评分》5分),鼻腔分泌物涂片见大量嗜酸性粒细胞,以及鼻粘膜水肿、粘膜嗜酸性粒细胞和肥大细胞浸润等组织学变化,而对照组无上述变化(P《0.001).本实验建立的豚草花粉变应原致过敏性鼻炎的实验动物模型,为过敏性鼻炎,特别是豚草花粉变应原所致的过敏性鼻炎的诊断、治疗及研究工作提供了有力的方法及形态学依据. 相似文献