全文获取类型
收费全文 | 5806篇 |
免费 | 250篇 |
国内免费 | 70篇 |
专业分类
耳鼻咽喉 | 34篇 |
儿科学 | 233篇 |
妇产科学 | 77篇 |
基础医学 | 554篇 |
口腔科学 | 111篇 |
临床医学 | 452篇 |
内科学 | 1248篇 |
皮肤病学 | 182篇 |
神经病学 | 419篇 |
特种医学 | 187篇 |
外科学 | 985篇 |
综合类 | 133篇 |
预防医学 | 240篇 |
眼科学 | 282篇 |
药学 | 550篇 |
1篇 | |
中国医学 | 36篇 |
肿瘤学 | 402篇 |
出版年
2024年 | 2篇 |
2023年 | 38篇 |
2022年 | 116篇 |
2021年 | 209篇 |
2020年 | 104篇 |
2019年 | 137篇 |
2018年 | 159篇 |
2017年 | 119篇 |
2016年 | 167篇 |
2015年 | 194篇 |
2014年 | 276篇 |
2013年 | 371篇 |
2012年 | 528篇 |
2011年 | 521篇 |
2010年 | 288篇 |
2009年 | 253篇 |
2008年 | 386篇 |
2007年 | 430篇 |
2006年 | 381篇 |
2005年 | 331篇 |
2004年 | 316篇 |
2003年 | 233篇 |
2002年 | 179篇 |
2001年 | 41篇 |
2000年 | 35篇 |
1999年 | 31篇 |
1998年 | 41篇 |
1997年 | 48篇 |
1996年 | 26篇 |
1995年 | 27篇 |
1994年 | 25篇 |
1993年 | 27篇 |
1992年 | 9篇 |
1991年 | 15篇 |
1990年 | 15篇 |
1989年 | 12篇 |
1988年 | 9篇 |
1987年 | 6篇 |
1986年 | 3篇 |
1985年 | 6篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1980年 | 1篇 |
1976年 | 4篇 |
1975年 | 1篇 |
排序方式: 共有6126条查询结果,搜索用时 0 毫秒
41.
Black tea and mammary gland carcinogenesis by 7,12- dimethylbenz[a]anthracene in rats fed control or high fat diets 总被引:3,自引:1,他引:3
Epidemiological studies suggest that tea may reduce cancer risk, and in
laboratory rodents, chemopreventive effects of tea or purified extracts of
tea have been demonstrated in lung, gastrointestinal tract and skin. There
is some evidence of chemoprevention by tea in the mammary gland, but the
data are not conclusive. In order to evaluate more fully the possible
influence of black tea on 7,12-dimethylbenz[a]anthracene (DMBA)-induced
mammary gland tumors in the female S-D (Sprague-Dawley) rat, three large
studies were performed: experiment 1, tumorigenesis in rats fed AIN-76A
diet and given 25 mg/kg DMBA and 1.25 or 2.5% whole tea extract or water to
drink; experiment 2, tumorigenesis in rats given 15 mg/kg DMBA and the same
diet and fluids as in experiment 1; experiment 3, tumorigenesis in rats fed
control or HF (high fat, corn oil) diet and given 15 mg/kg DMBA and 2% tea
or water to drink. Tea was given throughout the experiment; DMBA was given
by gastric gavage at 8 weeks of age. There was no consistent effect of tea
on tumorigenesis in rats fed AIN-76A diet; there was, however, evidence in
experiment 3 of a reduction of tumorigenesis by tea in rats fed the HF
diet. In experiment 3, rats fed the HF diet and given water showed the
expected increase in tumor burden (number and weight) compared with rats
fed control diet. However, rats fed the HF diet and given 2% tea showed no
increase in tumor burden; their tumor burden was significantly lower than
in rats fed the HF diet and given water (P < 0.01) and was not different
from rats fed control diet and given water or tea. In addition, in
experiment 3, the number of malignant tumors per tumor- bearing rat was
increased by the HF diet in water-drinking rats (P < 0.01) but not in
tea-drinking rats. Therefore, it appears that tea partially blocked the
promotion of DMBA-induced mammary tumorigenesis by the HF diet.
相似文献
42.
Gupta Sumita Mukherjee Aparna Lodha Rakesh Kabra Madhulika Deepak Kishore K. Khadgawat Rajesh Talwar Anjana Kabra Sushil Kumar 《Indian journal of pediatrics》2019,86(11):987-994
Indian Journal of Pediatrics - To evaluate effect of one year exercise intervention program on bone mineral accrual in children and adolescent with cystic fibrosis (CF). Fifty-two CF children (mean... 相似文献
43.
Shalendra Kumar Faheem Ahmed Nagih M. Shaalan Rajesh Kumar Adil Alshoaibi Nishat Arshi Saurabh Dalela Fatima Sayeed Sourabh Dwivedi Kavita Kumari 《Materials》2022,15(22)
Magnetic nanostructures of CoFe2O4 were synthesized via a microwave-assisted hydrothermal route. The prepared nanostructures were investigated using X-ray diffraction (XRD), field emission electron microscopy (FE-SEM), energy dispersive X-ray (EDX) spectroscopy, high-resolution transmission electron microscopy (HR-TEM), selective area electron diffraction (SAED) pattern, DC magnetization, and dielectric spectroscopy measurements. The crystal structure studied using HR-TEM, SAED, and XRD patterns revealed that the synthesized nanostructures had a single-phase nature and ruled out the possibility of any secondary phase. The lattice parameters and unit cell volume determined from the XRD data were found to be 8.4821 Å and 583.88 Å3. The average crystallite size (~7.0 nm) was determined using Scherrer’s equation. The FE-SEM and TEM micrographs revealed that the prepared nanostructures had a spherical shape morphology. The EDX results showed that the major elements present in the samples were Co, Fe, and O. The magnetization (M) versus temperature (T) measurements specified that the CoFe2O4 nanostructures showed ferromagnetic ordering at room temperature. The blocking temperature (TB) determined using the M-T curve was found to be 315 K. The magnetic hysteresis (M-H) loop of the CoFe2O4 nanostructures recorded at different temperatures showed the ferromagnetic behavior of the CoFe2O4 nanostructures at temperatures of 200 K and 300 K, and a superparamagnetic behavior at 350 K. The dielectric spectroscopy studies revealed a dielectric constant (ε′) and loss tangent (tanδ) decrease with the increase in the frequency, as well as demonstrating a normal dispersion behavior, which is due to the Maxwell–Wagner type of interfacial polarization. The values of ε′ and tanδ were observed to increase with the increase in the temperature. 相似文献
44.
BackgroundChronic obstructive pulmonary disease (COPD) is a more prevalent chronic lung disease with a significant health burden, and the majority of these cases receive inadequate treatment.MethodsProspective, observational, interview (questionnaire) based complete workup COPD study, screened 12,000 cases with chronic respiratory symptoms with cough, sputum production, and shortness of breath. A total of 6000 COPD cases were enrolled after the spirometry test. COPD cases were assessed as disease knowledge and methods of treatment offered by applying questionnaires to patients and treating physicians.ResultsIn the present study, 3% of study cases were aware of their COPD illness, 54% were not having knowledge about the disease, and 43% cases were not accepting the COPD diagnosis (p < 0.0001). A total of 58% of cases received inhalation treatment as levosalbutamol monotherapy in 31% cases, levosalbutamol plus beclometasone in 18% cases, and formoterol plus budesonide or salmeterol plus fluticasone only in 9% of COPD cases (p < 0.0001). Total 42% cases received oral treatment as theophylline in 16% cases, salbutamol in 7% cases, oral steroids in 19% cases (p < 0.0001).Conclusion“Doctor–patient–drug trio” discordance clubbed as “difficult doctor, difficult patient, and difficult treatment” is a very crucial issue observed during diagnosis and management of COPD in peripheral settings in India. 相似文献
45.
Mukul Vij Yogesh Puri Ashwin Rammohan Gowripriya G Rajesh Rajalingam Ilankumaran Kaliamoorthy Mohamed Rela 《World journal of gastrointestinal oncology》2022,14(3):607-627
Cholangiocarcinomas are a heterogeneous group of highly aggressive cancers that may arise anywhere within the biliary tree. There is a wide geographical variation with regards to its incidence, and risk-factor associations which may include liver fluke infection, primary sclerosing cholangitis, and hepatolithiasis amongst others. These tumours are classified into intrahepatic, perihilar and distal based on their anatomical location. Morphologically, intrahepatic cholangiocarcinomas are further sub-classified into small and large duct variants. Perihilar and distal cholangiocarcinomas are usually mucin-producing tubular adenocarcinomas. Cholangiocarcinomas develop through a multistep carcinogenesis and are preceded by dysplastic and in situ lesions. While clinical characteristics and management of these tumours have been extensively elucidated in literature, their ultra-structure and tumour biology remain relatively unknown. This review focuses on the current knowledge of pathological characteristics, molecular alterations of cholangiocarcinoma, and its precursor lesions (including biliary intraepithelial neoplasia, intraductal papillary neoplasms of the bile duct, intraductal tubulopapillary neoplasms and mucinous cystic neoplasm). 相似文献
46.
47.
Kumar D Tomar RS Deolia SK Mitra M Mukherjee R Burman AC 《Journal of pharmaceutical and biomedical analysis》2007,43(4):1228-1235
The degradation of docetaxel drug substance and its injection formulation has been investigated. The majority of impurities were observed in a base degradation study and all five degradation products were characterized. These impurities were isolated, enriched and were subjected to mass and NMR spectral studies. Based on the spectral data, these were characterized as 10-deacetyl baccatin III, 7-epi-10-deacetyl baccatin III, 7-epi-10-oxo-10-deacetyl baccatin III, 7-epi docetaxel and 7-epi-10-oxo-docetaxel, respectively. The last two impurities were also detected in the stability study of docetaxel formulation. Out of these degradation impurities two substances have been previously identified while the other three previously unreported. 相似文献
48.
单克隆抗体博来霉素A6偶联物对白血病细胞特异性结合与内化 总被引:2,自引:0,他引:2
抗CCT2单克隆抗体博来霉素A6偶联物可吸附胶体金颗粒(McAb-A6-Au)。电镜观察表明,在4℃,1h,表面有McAb-A6-Au颗粒的CEM细胞最高达78%;在37℃,4h,内化McAb-A6-Au颗粒的CEM细胞高达72%。而抗原性无关的U937细胞仅为14%。并且McAb-A6-Au颗粒能直接穿过细胞膜、核膜进入细胞浆和细胞核。37℃,1h已有10~18%的CEM细胞核内有McAb-A 6-Au颗粒。实验结果提示了单抗与博来霉素A6的偶联物与选择性地结合靶细胞,而且进入细胞速度快、穿透力强,有可能成为治疗白血病药物。 相似文献
49.
Background:Management of posterior scleral perforation is commonly done with cryotherapy/laser or scleral patch graft depending on the size of perforation. However, for large perforations, the availability of donor sclera is always an issue. To overcome this problem, we tried using absorbable gelatin sponge to plug the perforation as an alternative.Purpose:To evaluate the efficacy of gelatin foam as an alternative to scleral patch graft in cases with perforation of posterior sclera.Synopsis:Here we report the case of a 27-year-old male, who sustained penetrating injury to right eye with two metallic intraocular foreign bodies with visual acuity of hand movement close to face. Primary wound repair was done, followed by retrieval of the first piece of metallic foreign body that measured 11X3mm in size. The second foreign body visualized at posterior pole adjascent to the disc was removed using Machemar forceps and it measured 10X3 mmin size. Leakage of PFCL at the site confirmed a posterior scleral perforation. Cryotherapy was avoided due to its proximity to optic nerve head, and donor sclera was not readily available at that moment. We managed the case by plugging the defect with absorbable gelatin foam, followed by silicone oil injection into the vitreous cavity. Post operative outcome was good with restoration of anatomical integrity of the globe along with improvement in visual acuity upto 6/18.Highlights:Gelatin foam being absorbable and inciting less reaction aids in sealing the perforation and maintenance of globe contour with the advantage being readily available, cost-effective and it can be left in situ without the need for additional surgery for its removal. This would be of use in situations where the donor sclera is not readily available, and thus can be a potential alternative. However, further studies with larger sample size need to be done to evaluate and compare its effectiveness over donor scleral grafts.Online Video Link: https://youtu.be/fkardnkMQQo 相似文献
50.
How to cite this article: Hirolli D, Panda R, Baidya DK. Bygone Ether: Theriac to Obstinate Hiccups—Food for Thought! Indian J Crit Care Med 2022;26(7):884. 相似文献