全文获取类型
收费全文 | 40051篇 |
免费 | 2319篇 |
国内免费 | 54篇 |
专业分类
耳鼻咽喉 | 663篇 |
儿科学 | 1813篇 |
妇产科学 | 977篇 |
基础医学 | 4704篇 |
口腔科学 | 1912篇 |
临床医学 | 3538篇 |
内科学 | 8262篇 |
皮肤病学 | 1106篇 |
神经病学 | 3280篇 |
特种医学 | 1263篇 |
外科学 | 6392篇 |
综合类 | 134篇 |
一般理论 | 17篇 |
预防医学 | 2530篇 |
眼科学 | 1036篇 |
药学 | 2572篇 |
中国医学 | 182篇 |
肿瘤学 | 2043篇 |
出版年
2024年 | 43篇 |
2023年 | 369篇 |
2022年 | 239篇 |
2021年 | 712篇 |
2020年 | 471篇 |
2019年 | 770篇 |
2018年 | 1366篇 |
2017年 | 976篇 |
2016年 | 1040篇 |
2015年 | 901篇 |
2014年 | 1045篇 |
2013年 | 1766篇 |
2012年 | 2884篇 |
2011年 | 3461篇 |
2010年 | 1508篇 |
2009年 | 870篇 |
2008年 | 2895篇 |
2007年 | 3114篇 |
2006年 | 3015篇 |
2005年 | 2991篇 |
2004年 | 2847篇 |
2003年 | 2658篇 |
2002年 | 2502篇 |
2001年 | 809篇 |
2000年 | 947篇 |
1999年 | 527篇 |
1998年 | 212篇 |
1997年 | 185篇 |
1996年 | 161篇 |
1995年 | 137篇 |
1994年 | 115篇 |
1993年 | 106篇 |
1992年 | 76篇 |
1991年 | 56篇 |
1990年 | 66篇 |
1989年 | 56篇 |
1988年 | 46篇 |
1987年 | 36篇 |
1986年 | 32篇 |
1985年 | 33篇 |
1984年 | 41篇 |
1983年 | 33篇 |
1982年 | 49篇 |
1981年 | 37篇 |
1980年 | 39篇 |
1979年 | 26篇 |
1978年 | 22篇 |
1977年 | 31篇 |
1976年 | 17篇 |
1973年 | 14篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Risk factors associated with intracranial hemorrhage in adults with immune thrombocytopenia: A study of 27 cases 下载免费PDF全文
Sara Melboucy‐Belkhir Mehdi Khellaf Alexandre Augier Marouane Boubaya Vincent Levy Guillaume Le Guenno Louis Terriou Bertrand Lioger Mikaël Ebbo Anne‐Sophie Morin Marie‐Paule Chauveheid Marc Michel Farid Belkhir Frédégonde About Christian Rose Guillaume Moulis Arsene Mekinian Jérôme Stirnemann Thomas Papo Stéphane Cheze Eric Rosenthal Jean‐François Viallard Nicolas Schleinitz Lionel Galicier Daniel Adoue Olivier Lambotte Mohamed Hamidou Bertrand Godeau Olivier Fain 《American journal of hematology》2016,91(12):E499-E501
992.
Vitor Hugo Pereira João Português Lucy Calvo Inocência Machado Olga Azevedo António Lourenço 《The international journal of cardiovascular imaging》2014,30(6):1203-1204
The image shows a pseudoaneurysm of the mitral-aortic intervalvular fibrosa and a fistula between the non-coronary sinus and the left atrium. 相似文献
993.
OBJECTIVE: To localize inflammatory and chronic changes to defined areas in the sacroiliac joints in patients with early-stage compared with late-stage spondylarthritis (SpA), using magnetic resonance imaging (MRI). METHODS: Using MRI, 93 patients with SpA and inflammatory back pain who had radiographs of the sacroiliac joints were examined, comprising 31 patients with ankylosing spondylitis (AS) and 62 with other SpA subsets, including 48 with undifferentiated SpA (uSpA). MRI was performed using T1-weighted, T2*-weighted, STIR, and dynamic contrast-enhanced (gadolinium diethylenetriaminepentaacetic acid) sequences. Two readers retrospectively analyzed the images by differentiating 9 areas of the sacroiliac joints: the ventral and caudal joint capsule, cavum, subchondral bone, bone marrow, ligament entheses, and ligaments; the sacral and iliac sides were tabulated separately. RESULTS: By MRI, sacroiliitis was more often bilateral in AS (84%) than in uSpA (48%) (P = 0.01). Inflammatory changes were found in a mean +/- SD 4.7 +/- 2.9 regions/joint, with involvement of 4.5 +/- 3.2 regions in early disease versus 5.2 +/- 2.3 regions in late disease (P not significant [NS]). Involvement of the iliac side of the sacroiliac joints was found to be more frequent than the sacral side in early disease (58% versus 48%; P < 0.01) as compared with that in late disease (58% versus 63%; P NS). The dorsocaudal parts of the synovial joint and the bone marrow were the most frequently inflamed structures in early disease (P < 0.001 for ventral versus dorsal joint capsule). In contrast, involvement of the entheses was more common in advanced disease (early 43% versus late 86%; P < 0.001). Similarly, the ligaments were more frequently involved in the late stages (early 26% versus late 40%; P = 0.06). Both patterns of bone marrow inflammation (focal and diffuse) were observed in equal frequencies in early and late disease (17% and 42% versus 26% and 43%, respectively; P NS). HLA-B27-positive patients (n = 80) had more entheseal involvement than did HLA-B27-negative patients (n = 13) (60% versus 39%; P = 0.05). HLA-B27-negative patients had a shorter disease duration (2.2 years versus 4.4 years; P = 0.05) and were more often female (62%; P = 0.02). When all pathologic changes were assessed, the STIR sequence (performed in 62 patients) was less sensitive than the contrast-enhanced sequences in that it was not able to show all relevant changes in 27% of these patients (n = 17), failing to reveal inflammation of the cavum in 15 patients and of the bone marrow and joint capsule in 1 patient each. CONCLUSION: As visualized by MRI, sacroiliitis in SpA is characterized by involvement of different joint structures. Whereas the iliac and the sacral side of the sacroiliac joints are almost equally affected, the dorsocaudal synovial part of the joint is involved significantly more often than the ventral part, especially in early disease. Sacroiliac enthesitis is not a special feature of early sacroiliac inflammation. 相似文献
994.
Supplementation with Herbal Extracts to Promote Behavioral and Neuroprotective Effects in Experimental Models of Parkinson's Disease: A Systematic Review 下载免费PDF全文
Ianara Mendonça da Costa José Rodolfo Lopes de Paiva Cavalcanti Dinalva Brito de Queiroz Eduardo Pereira de Azevedo Amália Cinthia Meneses do Rêgo Irami Araújo Filho Paulo Parente Marco Antônio Botelho Fausto Pierdoná Guzen 《Phytotherapy research : PTR》2017,31(7):959-970
Parkinson's disease (PD) consists of a neurodegenerative pathology that has received a considerable amount of attention because of its clinical manifestations. The most common treatment consists of administering the drugs levodopa and biperiden, which reduce the effectiveness of the disease and the progress of its symptoms. However, phytotherapy treatment of PD has shown great potential in retarding the loss of dopaminergic neurons and minimizing the behavioral abnormalities. The aim of this study is to systematically review the use of supplemental herbal plants with cellular protective effect and behavioral activity in in vivo and in vitro experimental models. A total of 20 studies were summarized, where the effectiveness of herbal extracts and their isolated bioactive compounds was observed in animal models for PD. The main neurochemical mechanisms found in these studies are schematically represented. The herbal extracts and their biocompounds have antioxidant, anti‐apoptotic, and antiinflammatory properties, which contribute to avoiding neuronal loss. Reports show that besides acting on the biosynthesis of dopamine and its metabolites, these compounds prevent D2 receptors' hypersensitivity. It is suggested that further studies need be conducted to better understand the mechanisms of action of the bioactive compounds distributed in these plants. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
995.
Appenzeller J Mihci G Martin MT Gallard JF Menou JL Boury-Esnault N Hooper J Petek S Chevalley S Valentin A Zaparucha A Al-Mourabit A Debitus C 《Journal of natural products》2008,71(8):1451-1454
Three new diterpene alkaloids, agelasine J (3), agelasine K (4), and agelasine L (5), were isolated from the marine sponge Agelas cf. mauritiana collected in the Solomon Islands. The structures of these compounds were elucidated by physical data analyses. They displayed in vitro antimalarial activity against Plasmodium falciparum. 相似文献
996.
de Souza DE Senna-Fernandes V de Carvalho Brito L de Souza RS França D Manoel CV de Almeida MC Bernardo-Filho M 《The American journal of Chinese medicine》2007,35(6):977-986
In clinical acupuncture, when acupuncture points are stimulated, several types of reflex responses can be evoked. Consequently, different categories of physiological responses are induced, which include changes in the activities of internal organs and tissues. The acupuncture point Sanyinjiao (SP6) has been used successfully to treat different human gastrointestinal conditions. The aim of this work was to investigate the effects of end-organ response induced by acupuncture point SP6 on the bioavailability of the radiopharmaceutical sodium pertechnetate (Na99mTcO4) in Wistar rats. Healthy rats were allocated into 2 groups, control-CG and treated-TG. TG was bilaterally stimulated at acupuncture point SP6 with stainless steel needles. Ocular plexus administration of Na99mTcO4 (3.7MBq) was carried out 10 min after every needle insertion in all animals. Ten minutes later, the animals were killed, the organs were isolated, the radioactivity was determined in a well gamma counter, and the percentage of injected dose per gram of tissue (%ID/g) was determined for each organ. The %ID/g was significantly altered (p < 0.05) in the small intestine of TG (0.56 +/- 0.09) when compared to CG (0.82 +/- 0.18). These results may suggest that this stimulation might induce physiological responses capable of altering the bioavailability of the radiopharmaceutical sodium pertechnetate. These findings aid in providing a better understanding of acupuncture and its effects on various organs and tissues. 相似文献
997.
Seyithan Taysi Firas Shawqi Algburi Muhammed Enes Taysi Cuneyt Caglayan 《Phytotherapy research : PTR》2023,37(3):1115-1135
Caffeic acid phenethyl ester (CAPE), a main active component of propolis and a flavonoid, is one of the natural products that has attracted attention in recent years. CAPE, which has many properties such as anti-cancer, anti-inflammatory, antioxidant, antibacterial and anti-fungal, has shown many pharmacological potentials, including protective effects on multiple organs. Interestingly, molecular docking studies showed the possibility of binding of CAPE with replication enzyme. In addition, it was seen that in order to increase the binding security of the replication enzyme and CAPE, modifications can be made at three sites on the CAPE molecule, which leads to the possibility of the compound working more powerfully and usefully to prevent the proliferation of cancer cells and reduce its rate. Also, it was found that CAPE has an inhibitory effect against the main protease enzyme and may be effective in the treatment of SARS-CoV-2. This review covers in detail the importance of CAPE in alternative medicine, its pharmacological value, its potential as a cancer anti-proliferative agent, its dual role in radioprotection and radiosensitization, and its use against coronavirus disease 2019 (COVID-19). 相似文献
998.
999.
Recurrence of Plasmodium falciparum after treatment with quinine and doxycycline in the Amazon basin 下载免费PDF全文
Margarete do Socorro Mendonça Gomes José Luiz Fernandes Vieira Álvaro Augusto Ribeiro D'Almeida Couto Vanja Suely Calvosa D'Almeida Couto Michelle Valéria Dias Ferreira Vieira Francis Christian da Silva Pereira Ricado Luiz Dantas Machado 《Tropical medicine & international health : TM & IH》2017,22(2):133-138
1000.
Nuriye Yıldırım Özdemir Hüseyin Abalı Berna Öksüzoğlu Burçin Budakoğlu İlkay Akmangit Nurullah Zengin 《Supportive care in cancer》2009,17(4):399-403
Goals It is generally recommended to wait for at least 24 h before starting chemotherapy after implanting venous port catheters
(VPC). Our aim was to evaluate whether it is safe to start chemotherapy on the day of implantation.
Patients and methods One hundred eighty patients who had to be given chemotherapy on the day of VPC implantation at our institution from June 2005
to April 2007 were included.
Main results Of patients, 122 were male (67.8%) and median age was 55 years. Majority (133, 72.8%) had colon and gastric adenocancer. Median
time to chemotherapy onset from VPC implantation was 102 min (minimum–maximum, 12–402). One hundred sixty-four (91.1%) received
prolonged chemotherapy infusions beyond 48 h. No life-threatening acute complications like pneumothorax and hemothorax developed.
In one patient extravasation (empty saline extravasation secondary to wrong insertion of the needle), in 17 (9.4%) pain, and
in 41 (22.8%) minor bleeding as echymosis were seen. Thrombosis developed in 11 (6.1%). Reasons for VPC removal were thrombosis
(2), sepsis (2), cellulitis (1), skin dehiscence (1), and patient will (1).
Conclusion Chemotherapy administration immediately after VPC implantation appears safe without increased acute and chronic complications
in inpatient setting. 相似文献