全文获取类型
收费全文 | 2198篇 |
免费 | 127篇 |
国内免费 | 27篇 |
学科分类
医药卫生 | 2352篇 |
出版年
2023年 | 12篇 |
2022年 | 37篇 |
2021年 | 107篇 |
2020年 | 58篇 |
2019年 | 79篇 |
2018年 | 86篇 |
2017年 | 54篇 |
2016年 | 69篇 |
2015年 | 66篇 |
2014年 | 104篇 |
2013年 | 106篇 |
2012年 | 190篇 |
2011年 | 179篇 |
2010年 | 85篇 |
2009年 | 82篇 |
2008年 | 130篇 |
2007年 | 104篇 |
2006年 | 124篇 |
2005年 | 130篇 |
2004年 | 100篇 |
2003年 | 82篇 |
2002年 | 72篇 |
2001年 | 31篇 |
2000年 | 30篇 |
1999年 | 46篇 |
1998年 | 19篇 |
1997年 | 12篇 |
1996年 | 18篇 |
1995年 | 6篇 |
1994年 | 12篇 |
1993年 | 8篇 |
1992年 | 12篇 |
1991年 | 15篇 |
1990年 | 15篇 |
1989年 | 11篇 |
1988年 | 12篇 |
1987年 | 11篇 |
1986年 | 7篇 |
1985年 | 14篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1978年 | 3篇 |
1972年 | 1篇 |
1970年 | 1篇 |
1966年 | 1篇 |
1965年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有2352条查询结果,搜索用时 31 毫秒
71.
Abdullah MH Othman Z Noor HM Arshad SS Yusof AK Jamal R Rahman AR 《Journal of cardiology》2012,60(3):192-203
The molecular basis of coronary artery disease (CAD) has been widely studied in the western world but there is no published work on the Malaysian population. This study looked at the global gene expression profiling of the peripheral blood of patients with CAD from the 3 main ethnic groups in Malaysia. Male subjects selected were based on angiographically confirmed CAD (≥50% stenosis) and normal control subjects (0% stenosis) with age range of 55.6±5.3 and 51.0±5.5years, respectively. The global gene expression of 12 angiographically documented CAD patients and 11 matched control subjects were performed. The combined group samples identified 6 up regulated differential expression (DE) genes (GHRL, LTA, CBS, HP, ITGA2B, and OLR1) and 12 down regulated DE genes (IL18R1, ITGA2B, IL18RAP, HP, OLR1, SOD2 ITGB3, IL1B, MMP9, PLA2G7, UTS2, and CBS) to be involved in CAD at the fold change of 1.3 with fault discovery rate (FDR) of 1%. Three genes, MMP9, IL1B, and SOD2 were down regulated in all the 3 ethnic groups making them potential biomarker candidates for CAD across all three ethnicities. Further verification in a cohort study is needed. 相似文献
72.
73.
Paul D. Miller Sophie A. Jamal Sarah L. West 《Clinical reviews in bone and mineral metabolism》2012,10(3):163-173
Low bone mineral density (BMD) is a strong risk factor for low trauma fractures in the postmenopausal population without known chronic kidney disease (CKD). In stage 1?C3 CKD, low BMD can also be used to predict fracture risk with the gradient of risk similar to patients without CKD even though patients with stage 3 CKD have an approximate doubling of risk compared with age-matched patients without CKD. This greater risk of fracture in stage 3 CKD is not calculated in the current FRAX model. In stage 4?C5 CKD, BMD by dual-energy x-ray absorptiometry (DXA) is a poor predictor of fracture risk probably related to the severe derangements in bone metabolism in severe CKD, which alter bone quality and strength not measured by DXA. Serial BMD by DXA, however, may be useful in all stages of CKD to monitor for potential loss of BMD or effect of pharmacological agents to improve BMD. Newer radiological technologies, particularly high-resolution peripheral quantitative computerized tomography (HRpQcT) of the radius and tibia show promise to define the microstructural changes in bone that explain the greater risk of fracture observed in patients with CKD versus patients without CKD. BMD by DXA may still be of value across the spectrum of CKD, but physicians should realize its limitations and understand the greater risk of fracture in patients in all stages of CKD as compared to age-matched and BMD-matched patients without CKD. 相似文献
74.
Jamal Kazmi Poh Choon Ooi Boon Tong Goh Min Kai Lee M. F. Mohd. Razip Wee Siti Shafura A Karim Syed Raza Ali Raza Mohd Ambri Mohamed 《RSC advances》2020,10(39):23297
Room-temperature ferromagnetism in the large and direct bandgap diluted magnetic semiconductor zinc oxide (ZnO) is attributed to the intrinsic defects and p-orbital–p-orbital (p–p) coupling interaction. However, due to oxidation, the ferromagnetism induced by defects is unstable. In the present work, the solution process synthesis route was utilized to grow pristine and bismuth-doped, highly crystalline ZnO nanowire (ZnO NW)-based samples. The FE-SEM images showed that the grown ZnO NWs have a preferred orientation along the c-axis in the (001) direction due to the anisotropic crystal nature of ZnO. X-ray photoelectron spectroscopy (XPS) confirmed the presence of Bi, and at a higher doping content, the bismuth oxide phase appeared. The XRD patterns showed the wurtzite crystal structure, and the large intensity of the (002) peak suggests that most of the reflection was from the top hexagonal face of the NWs, and thus, the wires are predominantly aligned along the c-axis. The TEM analysis further confirmed the crystal growth direction along the (001) direction. The UV-Visible absorption and PL measurements also showed a decrease in the bandgap with an increase in doping concentration, which may be associated with the sp–d exchange interaction between the localized d-electrons and band electrons of the Bi ions. Bi-doping tended to increase the PL intensity in the visible region. The magnetic properties measured by SQUID at 4 and 300 K showed ferromagnetic behaviour for both the pristine and Bi-doped samples. However, the saturation magnetization for the Bi-doped samples was higher compared to that of the pristine ZnO samples until the threshold doping value. The obtained results demonstrated that Bi-doping can be used to tune both the optical and magnetic properties of ZnO NWs, hence paving the way for future spintronics and spin-polarized optoelectronics applications.Room-temperature ferromagnetism in the large and direct bandgap diluted magnetic semiconductor zinc oxide (ZnO) is attributed to the intrinsic defects and p-orbital–p-orbital (p–p) coupling interaction. 相似文献
75.
76.
77.
78.
Pneumothoraces are a possible sequela of chest trauma with potential morbidity and mortality if not recognized and treated promptly. A portable supine chest radiograph is frequently the first radiologic study performed in the setting of trauma. While large pneumothoraces can be readily recognized on these radiographs, smaller pneumothoraces are missed in up to 15 % of trauma patients. There are many radiographic signs of occult pneumothoraces, and we are presenting a new radiographic sign of occult pneumothorax. The floating cardiac fat pad sign occurs when pleural air collects anteriorly and superiorly in the most non-dependent portion of the chest lifting the pericardial fat pad off the diaphragm. Lung markings are still seen surrounding the pericardial fat pad due to the inflated lower lobe of the lung resting dependently. Rapid and accurate identification of pneumothoraces is critical but often difficult on chest radiographs. Although there are many existing radiographic signs for identification of pneumothorax, prospective identification of small pneumothoraces is still relatively poor. Here, we describe an additional sign which aides in the detection of pneumothoraces, the floating cardiac fat pad. When present, this should prompt further evaluation with chest CT or upright chest radiograph. 相似文献
79.
Asuka Ito Mostofa Jamal Kiyoshi Ameno Naoko Tanaka Ayaka Takakura Takanori Miki 《Drug and chemical toxicology》2018,41(2):245-247
Carbon monoxide (CO) produces several neurological effects, including cognitive, mood, and behavioral disturbance. Glutamate is thought to play a particularly important role in learning and memory. Thus, the present study was aimed at investigating the local effect of CO on the glutamate level in the hippocampus of mice using in vivo reverse microdialysis. Mice were perfused with Ringer’s solution (control) or CO (60–125?μM) in Ringer’s solution into the hippocampus via microdialysis probe. Dialysate samples were collected every 20?min, and then analyzed with high-performance liquid chromatography coupled to an electrochemical detector. The result revealed that the perfusion with CO had no significant effect on glutamate levels (p?=?0.316) as compared to the control group. This finding does not support a local CO rise as the cause of the increased glutamate level in the hippocampus of mice. 相似文献
80.
It has been previously shown that the interaction of some weakly basic drugs with oppositely charged fatty acids during digestion can influence the solid-state form of the drug if it precipitates. The present study hypothesized the opposite effect for weakly acidic drugs. Tolfenamic acid (TA) and an oppositely charged cationic surfactant, didodecyldimethylammonium bromide (DDAB) were combined in a model medium chain lipid formulation. The phase distribution upon in vitro lipolysis was determined using HPLC and the solid-state form of precipitated TA was determined using X-ray diffraction and crossed polarized light microscopy. TA precipitated in a different polymorphic crystalline form to the starting reference material in the absence of DDAB but precipitated in an amorphous form when DDAB was included in the same formulation. The solubility of TA upon dispersion and digestion of the formulation was considerably higher in the presence of DDAB. The findings point to ionic interactions between TA and DDAB as the reason for the improved drug solubility throughout digestion, and precipitation of drug in an amorphous salt form, analogous to what has been observed in the past for some poorly water-soluble weakly basic drugs with anionic co-formers. 相似文献