全文获取类型
收费全文 | 5970篇 |
免费 | 380篇 |
国内免费 | 30篇 |
专业分类
耳鼻咽喉 | 62篇 |
儿科学 | 136篇 |
妇产科学 | 189篇 |
基础医学 | 705篇 |
口腔科学 | 238篇 |
临床医学 | 514篇 |
内科学 | 1315篇 |
皮肤病学 | 135篇 |
神经病学 | 291篇 |
特种医学 | 195篇 |
外国民族医学 | 4篇 |
外科学 | 991篇 |
综合类 | 105篇 |
现状与发展 | 2篇 |
一般理论 | 2篇 |
预防医学 | 306篇 |
眼科学 | 159篇 |
药学 | 649篇 |
中国医学 | 41篇 |
肿瘤学 | 341篇 |
出版年
2023年 | 80篇 |
2022年 | 224篇 |
2021年 | 344篇 |
2020年 | 219篇 |
2019年 | 283篇 |
2018年 | 359篇 |
2017年 | 228篇 |
2016年 | 225篇 |
2015年 | 223篇 |
2014年 | 261篇 |
2013年 | 336篇 |
2012年 | 464篇 |
2011年 | 410篇 |
2010年 | 254篇 |
2009年 | 192篇 |
2008年 | 279篇 |
2007年 | 261篇 |
2006年 | 237篇 |
2005年 | 291篇 |
2004年 | 216篇 |
2003年 | 211篇 |
2002年 | 175篇 |
2001年 | 47篇 |
2000年 | 31篇 |
1999年 | 47篇 |
1998年 | 36篇 |
1997年 | 27篇 |
1996年 | 29篇 |
1995年 | 23篇 |
1994年 | 13篇 |
1993年 | 19篇 |
1992年 | 24篇 |
1991年 | 19篇 |
1990年 | 16篇 |
1989年 | 23篇 |
1988年 | 21篇 |
1987年 | 21篇 |
1986年 | 21篇 |
1985年 | 29篇 |
1984年 | 13篇 |
1983年 | 20篇 |
1982年 | 10篇 |
1981年 | 14篇 |
1980年 | 15篇 |
1979年 | 18篇 |
1977年 | 10篇 |
1976年 | 12篇 |
1975年 | 13篇 |
1974年 | 6篇 |
1972年 | 8篇 |
排序方式: 共有6380条查询结果,搜索用时 15 毫秒
21.
22.
Evaluation of the anti-inflammatory, anti-nociceptive and gastric effects of Ginkgo biloba in the rat. 总被引:2,自引:0,他引:2
Omar M E Abdel-Salam Ayman R Baiuomy Seham El-batran Mahmoud S Arbid 《Pharmacological research》2004,49(2):133-142
Ginkgo biloba extract (GbE) was assessed in models of acute inflammation induced by carrageenan, formalin or capsaicin in the rat, in models of nociceptive pain, such as hot-plate (55 degrees C) latency, tail-electric stimulation assay and capsaicin-induced paw licking and in the model of acute gastric damage induced by indomethacin. The agent showed marked anti-inflammatory activity in the carrageenan model of paw oedema. When given subcutaneously (s.c.) (25 and 50 mg kg(-1)) 30 min before challenge, GbE inhibited paw oedema with a maximal effect of 43.7 and 56.9%, respectively, at 2h post-carrageenan. Significant inhibition of oedema was also observed when GbE (50 mg kg(-1), s.c.) was given 30 min after carrageenan challenge. The agent was also active p.o. in acute inflammation caused by carrageenan. The administration of GbE with indomethacin, rofecoxib, celecoxib, dexamethasone or melatonin resulted in an additive effect. GbE (50 mg kg(-1), s.c.) caused significant inhibition of formalin-induced paw oedema, but did not reduce the capsaicin-induced paw oedema. In tests of nociception, GbE (25, 50 or 100 mg kg(-1)) decreased in dose-dependent manner the capsaicin-induced hind paw licking time and was similarly effective in the hot-plate assay of nociception. In contrast, when assessed in the tail-electric stimulation test, GbE was only effective in the highest dose (100 mg kg(-1)). In pylorus-ligated rats, GbE (25 or 50 mg kg(-1)) increased gastric acid secretion, but reduced gastric mucosal damage caused by IND. Results suggest that GbE may be of clinical value as an anti-inflammatory and analgesic drug alone or in conjunction with NSAIDs. 相似文献
23.
24.
Ali H. Abu Ibaid Caitlin A. Hebron Hana'a A. Qaysse Melanie J. Coyne Tom S. Potokar Fikr A. Shalltoot Mahmoud A. Shalabi 《International wound journal》2022,19(5):1210
The aim of this study was to identify the epidemiology, aetiology as well as the knowledge, attitudes, and practices relating to burn injuries in Palestine. A mixed‐method approach was used. A survey was distributed to a total of 1500 households selected by randomised approach. The survey was standardised based on World Health Organisation''s guidelines for conducting community surveys on injury. Additionally, there were 12 focus group discussions and 10 key informant interviews to collect rich qualitative data. In the West Bank and Gaza, 1.5% of Palestinians had experienced serious burn injuries in the 12 months. The total sample of 1500 yields a margin of error (plus/minus) = 2.5% at a 95% level of confidence and a response distribution (P = 50%) with 3% non‐response rate. Of the 1500 households approached, 184 reported a total of 196 burn injuries, with 87.2% occurring inside the home: 69.4% were females and 39.3% were children. The main source of reported cause of burn was heat and flame (36%), electric current (31.6%), hot liquid (28.6%), and chemicals (2.7%). The most common first aid for burns was pouring water (74.7%). People in rural, refugee, and Bedouin settings had the highest incidence of burns. This study provides the burn prevalence rate, explanatory factors that contribute to the frequency of burns in Palestine. Making burn prevention a higher priority within the national policy is crucial. 相似文献
25.
The eye is an invulnerable organ with intrinsic anatomical and physiological barriers, hindering the development of a pioneer ocular formulation. The aim of this work was to develop an efficient ocular delivery system that can augment the ocular bioavailability of the antifungal drug, terconazole. Mesoporous silica microparticles, Syloid® 244 FP were utilized as the carrier system for terconazole. Preliminary studies were carried out using different drug:Syloid® weight ratios. The optimum weight ratio was mixed with various concentrations (30 and 60%w/w) of poly (lactic-co-glycolic acid) (PLGA), ester or acid-capped and with different monomers-ratio (50:50 and 75:25) using the nano-spray dryer. Results revealed the superiority of drug:Syloid® weight ratio of 1:2 in terms of yield percentage (Y%), SPAN and drug content percentage (DC%). Furthermore, incorporation of PLGA with lower glycolic acid monomer-ratio significantly increased Y%. In contrast, increasing the glycolic acid monomer-ratio resulted in higher DC% and release efficiency percentage (RE%). Additionally, doubling PLGA concentration significantly reduced Y%, DC%, drug loading percentage (DL%) and RE%. Applying desirability function in terms of increasing DC%, DL% besides RE% and decreasing SPAN, the selected formulation was chosen for DSC, XRD and SEM investigations. Results confirmed the successful loading of amorphized terconazole on PLGA-modified Syloid® microparticles. Moreover, pharmacokinetic studies for the chosen formulation on male Albino rabbits’ eyes revealed a 2, 6.7 and 25.3-fold increase in mean residence time, Cmax and AUC0–24-values, respectively, compared to the drug suspension. PLGA-modified Syloid® microparticles represent a potential option to augment the bioavailability of ocular drugs. 相似文献
26.
The presence of nitrates in water in large amounts is one of the most dangerous health issues. The greatest risk posed by nitrates is hemoglobin oxidation, which results in Methemoglobin in the human body, resulting in Methemoglobinemia. There are many ways to eliminate nitrates from underground water. One of the most effective and selective methods is using zero-valent iron (ZVI) nanoparticles. ZVI nanoparticles can be easily synthesized by reducing ferric or ferrous ions using sodium borohydride. The prepared ZVI nanoparticles were examined by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), electron microscopy (TEM), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) surface area, and zeta potential. We aim to eliminate or reduce the nitrates in water to be at the acceptable range, according to the world health organization (WHO), of 10.0 mg/L. Nitrate concentration in water after and before treatment is measured using the UV scanning method at 220 nm wavelength for the synthetic contaminated water and electrochemical method for the naturally contaminated water. The conditions were optimized for obtaining an efficient removing process. The removal efficiency reaches about 91% at the optimized conditions. 相似文献
27.
The effect of complexation of glimepiride, a poorly water-soluble antidiabetic drug, with β-cyclodextrin and its derivatives (HP-β-CyD and SBE-β-CyD) in presence of different concentrations of water-soluble polymers (HPMC, PVP, PEG 4000 and PEG 6000) on the dissolution rate of the drug has been investigated. The results revealed that the dissolution rate of the drug from these ternary systems is highly dependent on polymer type and concentration. The dissolution rate of the drug from ternary systems containing PEG 4000 or PEG 6000 seems to be generally higher than from systems containing HPMC or PVP. An optimum increase in the dissolution rate of the drug was observed at a polymer concentration of 5% for PEG 4000 or PEG 6000 and at 20% concentration of HPMC or PVP. The dissolution rate of the drug from the ternary system glimepiride–HP-β-CyD–5% PEG 4000 was high compared to the other systems. Tablets containing the drug or its equivalent amount of this ternary system were prepared and subjected to accelerated stability testing at 40 °C/75% R.H. to investigate the effect of storage on the chemical stability as well as therapeutic efficacy of the tablets. The results revealed stability of the tablets and consistent therapeutic efficacy on storage. 相似文献
28.
Mahmoud Omer Hessein Ali Nina Orlovskaya Amelia Ballesteros Vee San Cheong Kari Martyniak Fei Wei Boyce E. Collins Sergey N. Yarmolenko Jackson Asiatico Michael Kinzel Christopher Ngo Jagannathan Sankar Ashley Calder Timothy Gilbertson Teerin Meckmongkol Ranajay Ghosh Melanie Coathup 《Nutrients》2022,14(15)
The influence of diet on the development of osteoporosis is significant and not fully understood. This study investigated the effect of diets of varying lipid profiles and ω-3, ω-6 and ω-9 composition on the structural and mechanical properties of bone. The hypothesis studied was that a diet high in saturated fat would induce osteoporosis and produce an overall increased detrimental bony response when compared with a diet high in unsaturated ω-6, or ω-9. Male C57BL/6J mice were fed either a control diet, 50:50 mix (saturated:unsaturated) high in ω-9 (HFD50:50), a diet high in saturated fat (HSF) or a polyunsaturated fat diet high in ω-6 (PUFA) over an 8-week duration. Tibiae were retrieved and evaluated using DMA, 3-point-bending, histomorphometry, and microCT. Mice fed a HSF diet displayed key features characteristic of osteoporosis. The loss tangent was significantly increased in the HFD50:50 diet group compared with control (p = 0.016) and PUFA-fed animals (p = 0.049). HFD50:50-fed mice presented with an increased viscous component, longer tibiae, increased loss modulus (p = 0.009), and ultimate stress, smaller microcracks (p < 0.001), and increased trabecular width (p = 0.002) compared with control animals. A diet high in ω-9 resulted in an overall superior bone response and further analysis of its role in bone health is warranted. 相似文献
29.
Jain S Zharikova OL Ravindran S Nanovskya TN Mattison DR Hankins GD Ahmed MS 《American journal of perinatology》2008,25(3):169-174
The aim of this investigation was to determine the metabolism of glyburide (GL) by microsomes prepared from placentas obtained from uncomplicated pregnancies (UP), women with gestational diabetics (GD) on a diabetic diet, and those on a diet and GL. Term placentas were obtained from UP and GD. Crude microsomal fractions were prepared by differential centrifugation and stored at -80 degrees C. The activity of the microsomes in metabolizing glyburide to the trans-4-hydroxycyclohexyl glyburide (THCGL) and cis-3-hydroxycyclohexyl glyburide (CHCGL) was determined and quantified using high-performance liquid chromatography-mass spectrometer (HPLC-MS). The activity of the placental microsomes varied widely between individual placentas in each group. The median values (pmol.mg (-1) P.min (-1)) for the rates of THCGL formation were 0.34, 0.3, and 0.23 for placentas of UP, GD on diet, and GD on GL and a diet, respectively. The median values for CHCGL formation were 0.13 for UP, 0.11 for GD on a diet, and 0.10 (pmol.mg (-1) P.min (-1)) for GD on GL and a diet. A pool of individual microsomal fractions from each group was prepared and its activity revealed the following: greater formation of THCGL in the UP (0.36 +/- 0.10) than GD (0.22 +/- 0.03) ( P = 0.058 for GD on a diet, 0.04 for GD on GL). There was greater formation of CHCGL in UP (0.26 +/- 0.04) than GD (0.12 +/- 0.003) ( P < 0.006). There was no difference in GD on a diet and GD on GL plus diet. We concluded that the apparent differences in the formation of metabolites may be statistically significant, but it is unlikely to be of physiological importance, given the sample size and other experimental factors. Therefore, a more comprehensive investigation is underway. 相似文献
30.
V. Bharath V. Auradi G. B. Veeresh Kumar Madeva Nagaral Murthy Chavali Mahmoud Helal Rokayya Sami NI Aljuraide Jong Wan Hu Ahmed M. Galal 《Materials》2022,15(12)
The paper focused on an experimental study on the microstructural, mechanical, and wear characteristics of 15 wt.% alumina (Al2O3) particulates with an average particle size of 20 µm, reinforced in Al2014 alloy matrix composite as-cast and heat-treated samples. The metal matrix composite (MMC)samples were produced via a novel two-stage stir-casting technique. The fabricated composite samples were subjected to evaluate hardness, tensile strength, fatigue behavior and wear properties for both as cast and T6 heat-treated test samples. The Al2014 alloy and Al2014-15 wt.% Al2O3 MMCs were in solution for 1 h at a temperature of 525 °C, quenched instantly in cold water, and then artificially aged for 10 h at a temperature of 175 °C. SEM and X-ray diffraction analyses were used to investigate the microstructure and dispersion of the reinforced Al2O3 particles in the composite and the base alloy Al2014. The obtained results indicated that the hardness, tensile and fatigue strength and wear resistance increased when an amount of Al2O3 particles was added, compared to the as-cast Al2014 alloy and it was observed that after subjecting the same composite samples to heat treatment, there was further enhancement in the mechanical and wear properties in the Al2014 matrix alloy and Al2014-15 wt.% Al2O3 composite samples. 相似文献