全文获取类型
收费全文 | 20733篇 |
免费 | 1332篇 |
国内免费 | 89篇 |
专业分类
耳鼻咽喉 | 194篇 |
儿科学 | 561篇 |
妇产科学 | 407篇 |
基础医学 | 2365篇 |
口腔科学 | 349篇 |
临床医学 | 1812篇 |
内科学 | 4386篇 |
皮肤病学 | 249篇 |
神经病学 | 1148篇 |
特种医学 | 549篇 |
外科学 | 3434篇 |
综合类 | 685篇 |
一般理论 | 19篇 |
预防医学 | 1711篇 |
眼科学 | 562篇 |
药学 | 2143篇 |
中国医学 | 260篇 |
肿瘤学 | 1320篇 |
出版年
2023年 | 220篇 |
2022年 | 715篇 |
2021年 | 890篇 |
2020年 | 535篇 |
2019年 | 641篇 |
2018年 | 746篇 |
2017年 | 517篇 |
2016年 | 447篇 |
2015年 | 564篇 |
2014年 | 784篇 |
2013年 | 995篇 |
2012年 | 1441篇 |
2011年 | 1430篇 |
2010年 | 804篇 |
2009年 | 609篇 |
2008年 | 1067篇 |
2007年 | 1049篇 |
2006年 | 970篇 |
2005年 | 892篇 |
2004年 | 831篇 |
2003年 | 749篇 |
2002年 | 636篇 |
2001年 | 562篇 |
2000年 | 501篇 |
1999年 | 405篇 |
1998年 | 157篇 |
1997年 | 145篇 |
1996年 | 117篇 |
1995年 | 122篇 |
1994年 | 70篇 |
1993年 | 87篇 |
1992年 | 209篇 |
1991年 | 193篇 |
1990年 | 171篇 |
1989年 | 172篇 |
1988年 | 145篇 |
1987年 | 153篇 |
1986年 | 125篇 |
1985年 | 136篇 |
1984年 | 110篇 |
1983年 | 87篇 |
1982年 | 63篇 |
1981年 | 62篇 |
1979年 | 98篇 |
1978年 | 67篇 |
1977年 | 68篇 |
1975年 | 62篇 |
1974年 | 52篇 |
1973年 | 54篇 |
1972年 | 51篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
Cytotoxic Effects of Betel Quid and Areca Nut Aqueous Extracts on Mouse Fibroblast,Human Mouth-Ordinary-Epithelium 1 and Human Oral Squamous Cell Carcinoma Cell Lines
下载免费PDF全文
![点击此处可从《Asian Pacific journal of cancer prevention》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Badr Abdullah Al-TayarAzlina AhmadMohamad Ezany YusoffSiti Fadilah AbdullahNoor Khairiena MohamadSiti Nurnasihah Md HashimShosei KishidaMichiko KishidaNorifumi NakamuraToshiro KibeMasitah Hayati Harun 《Asian Pacific journal of cancer prevention》2020,21(4):1005-1009
Background: Betel quid chewing is more common among the older generation in rural areas of Malaysia. Oral cancer in Asia has been associated with the habit of chewing betel quid and areca nut. Objective: This study aims to investigate the cytotoxic effects of betel quid and areca nut extracts on the fibroblast (L929), mouth-ordinary-epithelium 1 (MOE1) and oral squamous cell carcinoma (HSC-2) cell lines. Methods: L929, MOE1 and HSC-2 cells were treated with 0.1, 0.2 and 0.4 g/ml of betel quid and areca nut extracts for 24, 48 and 72 h. MTT assay was performed to assess the cell viability. Results: Both extracts, regardless of concentration, significantly reduced the cell viability of L929 compared with the control (P<0.05). Cell viability of MOE1 was significantly enhanced by all betel quid concentrations compared with the control (P<0.05). By contrast, 0.4 g/ml of areca nut extract significantly reduced the cell viability of MOE1 at 48 and 72 h of incubation. Cell viability of HSC-2 was significantly lowered by all areca nut extracts, but 0.4 g/ml of betel quid significantly increased the cell viability of HSC-2 (P<0.05). Conclusion: Areca nut extract is cytotoxic to L929 and HSC-2, whereas the lower concentrations of areca nut extract significantly increased the cell viability of MOE1 compared to the higher concentration and control group. Although betel quid extract is cytotoxic to L929, the same effect is not observed in MOE1 and HSC-2 cell lines. Further investigations are needed to clarify the mechanism of action. 相似文献
993.
Tejaswini Parlapalle Reddy Usman Khan Ethan Alexander Burns Maen Abdelrahim 《World journal of clinical oncology》2020,11(11):959-967
BACKGROUNDColorectal cancer (CRC) is the third leading cause of cancer-related death in males and females in the United States. Approximately, 20%-22% of patients have metastatic disease at the time of presentation, and 50%-60% will develop metastasis over the course of their disease. Despite advances in systemic therapies, there remains a paucity of effective third- and later-line therapies for patients with ongoing disease progression. However, rechallenging chemo-resistant CRC tumors with previously administered therapies is an emerging concept that may be a life-prolonging option for heavily treated metastatic colorectal cancer (mCRC).CASE SUMMARYA 41-year-old man with no previous medical history initially presented with worsening diffuse abdominal tenderness. Computed tomography was significant for a splenic flexure mass and hepatic lesions concerning for metastatic disease. He underwent a colectomy with anastomosis. Postoperative pathology was diagnostic for moderately to well-differentiated adenocarcinoma (T4bN1bM1a). He received adjuvant 5-fluorouracil, leucovorin, and oxaliplatin (FOLFOX), but therapy was discontinued due to the development of atrial fibrillation. Additional workup indicated a carcinoembryonic antigen level of 508.2 ng/mL, and mutational analysis found that the tumor was microsatellite instability-high and KRAS/BRAF wild-type. He was started on irinotecan with oxaliplatin (IROX), and bevacizumab (14 cycles), developed disease progression, was transitioned to FOLFOX and cetuximab, and then eventually three cycles of pembrolizumab. Following disease progression, he was rechallenged with IROX therapy, as he previously responded well to oxaliplatin-based therapy. The IROX rechallenge provided this patient with a ten-month survival benefit, decreased metastatic burden, and marked improvement in his clinical condition.CONCLUSIONRechallenge of previous lines of well-tolerated systemic chemotherapy regimens may be a valuable therapeutic strategy in patients with heavily-treated mCRC. 相似文献
994.
International disaster databases and catalogs provide a baseline for researchers, governments, commu-nities, and organizations to understand the risk of a par-t... 相似文献
995.
996.
Mohammad Ashraful Amin Md Taufiqul Islam Ishtiakul Islam Khan Zahid Hasan Khan Firdausi Qadri Ashraful Islam Khan 《Clinical Case Reports》2022,10(1)
Bangladesh recently faced large outbreaks of both COVID‐19 and dengue. We present a case of COVID‐19 and dengue coinfection in a patient who presented with hemoptysis. Our results demonstrate that COVID‐19 and dengue fever are both public health issues in Bangladesh and other dengue‐endemic nations and that they can coexist. 相似文献
997.
Md Minarul Islam Rashedul Alam Hea-Jong Chung Nazim Uddin Emon Mohammad Fazlul Kabir Sajib Rudra Safaet Alam Ahsan Ullah Seong-Tshool Hong Mohammed Aktar Sayeed 《Nutrients》2022,14(2)
Bauhinia scandens L. (Family: Fabaceae) is commonly used to treat cholera, diarrhea, asthma, and diabetes disorder in integrative medicine. This study aimed to screen the presence of phytochemicals (preliminary and UPLC-QTOF–M.S. analysis) and to examine the pharmacological activities of Bauhinia scandens L. stems (MEBS) stem extracts. Besides, in silico study was also implemented to elucidate the binding affinity and drug capability of the selected phytochemicals. In vivo anti diarrheal activity was investigated in mice models. In vitro, antibacterial and antifungal properties of MEBS against several pathogenic strains were evaluated using the disc diffusion method. In addition, in silico study has been employed using Discovery studio 2020, UCFS Chimera, PyRx autodock vina, and online tools. In the anti-diarrheal investigation, MEBS showed a significant dose-dependent inhibition rate in all three methods. The antibacterial and antifungal screening showed a remarkable zone of inhibition, of the diameter 14–26 mm and 12–28 mm, by MEBS. The present study revealed that MEBS has remarkable anti-diarrheal potential and is highly effective in wide-spectrum bacterial and fungal strains. Moreover, the in silico study validated the results of biological screenings. To conclude, MEBS is presumed to be a good source in treating diarrhea, bacterial and fungal infections. 相似文献
998.
Mustafa Anwar Muhammed Ali Shaikh Abdul Uneeb Masood Khan Muhammad Hassan Asif Hussain Khoja Andanastuti Muchtar 《Materials》2022,15(7)
Nondestructive characterization of solid oxide fuel cell (SOFC) materials has drawn attention owing to the advances in instrumentation that enable in situ characterization during high-temperature cell operation. X-ray photoelectron spectroscopy (XPS) is widely used to investigate the surface of SOFC cathode materials because of its excellent chemical specificity and surface sensitivity. The XPS can be used to analyze the elemental composition and oxidation state of cathode layers from the surface to a depth of approximately 5–10 nm. Any change in the chemical state of the SOFC cathode at the surface affects the migration of oxygen ions to the cathode/electrolyte interface via the cathode layer and causes performance degradation. The objective of this article is to provide a comprehensive review of the adoption of XPS for the characterization of SOFC cathode materials to understand its degradation mechanism in absolute terms. The use of XPS to confirm the chemical stability at the interface and the enrichment of cations on the surface is reviewed. Finally, the strategies adopted to improve the structural stability and electrochemical performance of the LSCF cathode are also discussed. 相似文献
999.
Upconverting luminescent nanoparticles (UCNPs) are “new generation fluorophores” with an evolving landscape of applications in diverse industries, especially life sciences and healthcare. The anti-Stokes emission accompanied by long luminescence lifetimes, multiple absorptions, emission bands, and good photostability, enables background-free and multiplexed detection in deep tissues for enhanced imaging contrast. Their properties such as high color purity, high resistance to photobleaching, less photodamage to biological samples, attractive physical and chemical stability, and low toxicity are affected by the chemical composition; nanoparticle crystal structure, size, shape and the route; reagents; and procedure used in their synthesis. A wide range of hosts and lanthanide ion (Ln3+) types have been used to control the luminescent properties of nanosystems. By modification of these properties, the performance of UCNPs can be designed for anticipated end-use applications such as photodynamic therapy (PDT), high-resolution displays, bioimaging, biosensors, and drug delivery. The application landscape of inorganic nanomaterials in biological environments can be expanded by bridging the gap between nanoparticles and biomolecules via surface modifications and appropriate functionalization. This review highlights the synthesis, surface modification, and biomedical applications of UCNPs, such as bioimaging and drug delivery, and presents the scope and future perspective on Ln-doped UCNPs in biomedical applications. 相似文献
1000.
Azhar Equbal Mohammad Ali Md. Asif Equbal S. C. Srivastava Zahid A. Khan Md. Israr Equbal Irfan Anjum Badruddin Khalid Mohamed El-Hady Sarfaraz Kamangar 《Materials》2022,15(7)
In this study, compacted hematite (Fe2O3) preforms were made and sintered at various temperatures, such as 1250 °C and 1300 °C, using both conventional and microwave sintering methods. The density, porosity, microhardness, cold crushing strength, microphotographs, and X-ray diffraction (XRD) analysis of the sintered preforms were used to evaluate the performance of the two sintering methods. It was found that microwave sintered preforms possessed lesser porosity and higher density than conventionally sintered preforms owing to uniform heating of the powdered ore in microwave sintering method. Furthermore, it was also observed that microwave sintered preforms exhibited relatively higher cold crushing strength and hardness than conventionally sintered preforms. Thus, the overall results revealed that microwave sintering yielded better properties considered in the present study. 相似文献