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排序方式: 共有531条查询结果,搜索用时 15 毫秒
1.
Mengdie Jiang Bihan Wu Yongbing Sun Yanhuai Ding Yixi Xie 《Toxicology mechanisms and methods》2019,29(4):291-299
In a biological microenvironment, free fatty acids (FFA) as ubiquitous biological molecules might interact with nanoparticles (NPs) and consequently change the toxicological responses. However, whether the chemical structures of FFA could influence their interactions with NPs remain unknown. This study investigated the interactions between ZnO NPs and saturated or unsaturated FFA (complexed to BSA), namely stearic acid (SA, C18:0), oleic acid (OA, C18:1), and α-linolenic acid (ALA, C18:3). It was shown that BSA, SA, OA, and ALA increased the atomic force microscope (AFM) heights as well the polydispersity index (PDI) of ZnO NPs. BSA modestly protected THP-1 macrophages from ZnO NP exposure, whereas OA and ALA led to relatively less cyto-protective effects of BSA. Moreover, only co-exposure to ZnO NPs and SA significantly promoted the release of interleukin-8. BSA, SA, OA, and ALA equally changed intracellular ROS and Zn ions associated with ZnO exposure, but co-exposure to ZnO NPs and OA/ALA particularly activated the expression of endoplasmic reticulum stress-apoptosis genes. In combination, these results showed that FFA could influence the colloidal aspects and toxicological signaling pathway of ZnO NPs, which is dependent on the number of unsaturated bonds of FFA. 相似文献
2.
化痰方、肝脾方抗大鼠脂肪肝模型作用机制的比较研究 总被引:7,自引:1,他引:6
目的 :探讨和比较化痰方、肝脾方抗大鼠脂肪肝模型作用机制。方法 :用高脂饮食联合四环素腹腔注射致大鼠脂肪肝模型 ,观察肝组织病理变化 ,检测肝功能 (ALT、AST)、血甘油三酯 (TG)、肝匀浆TG、游离脂肪酸 (FFA)、丙二醛 (MDA)的含量。并与正常组、东宝肝泰组对照。结果 :三个用药组的血清ALT、AST及肝匀浆FFA、TG、MDA均显著低于模型组 (P <0 .0 1 ) ,并显示抗脂肪肝的作用强弱依次为 :肝脾组优于化痰组优于东宝组 (P <0 .0 5或P <0 .0 1 )。结论 :促进脂质代谢、抗脂质过氧化可能是化痰祛浊、疏肝健脾法治疗脂肪肝作用的主要机制 相似文献
3.
Summary Utilization of carbohydrates and free fatty acids (FFA) has been investigated in gastrocnemii of dogs during long lasting isotonic rhythmical exercise induced by supramaximal stimulation of the sciatic nerve. Uptake or output of gases and substrates was determined according to the Fick principle. The first measurements were done at about 2 min after the beginning of work when blood flow has reached a steady state, and the latest at about 100 min after the beginning of exercise.During the first 7 min when the work performed exceeded 5 kg/100g×min and O2 consumption exceeded 11 ml/100g×min, uptake of arterial glucose and FFA was low, accounting for less than 40% of the total O2 consumption. Since the RQ values at the same time were about 1.0, glycogen must have been oxidized as the major aerobic energy source.About 13 min after the beginning of exercise, the work the muscles could perform declined to about half of the initial value and remained so for the following 90 min. During this time the oxygen extraction ratio of FFA was about 50% and of arterial glucose was 40–50%, while the RQ value was about 0.8.During initial strong exercise an output of lactic acid (LA) of about 10 mg/100 g×min was measured. With the decrease of work as a consequence of fatigue, LA output became negligible, and in many experiments small amounts of LA were taken up by the working gastrocnemii.It is concluded that glycogen is the major aerobic energy source for strong muscular exercise which cannot be substituted for by the oxidation of arterial glucose or FFA.Supported by the Deutsche Forschungsgemeinschaft. 相似文献
4.
目的探讨米力农(milrinone)对大鼠胰岛素分泌的影响。方法在0时静脉给予3组大鼠不同剂量的磷酸二酯酶抑制剂milrinone(剂量为:1,5,25 μmol·kg-1),并在给药前后观察其血糖、血浆胰岛素和游离脂肪酸(FFA)随时间变化的过程。结果给予milrinone的3组大鼠血浆FFA和胰岛素水平明显高于给药前和对照组,而仅25 μmol·kg-1组血糖明显升高。结论Milrinone 通过抑制磷酸二酯酶Ⅲ(PDE-3),使细胞内cAMP浓度升高而促进了胰岛β细胞分泌。但其也抑制了胰岛素的抗酯解作用,因而可能诱导了胰岛素抵抗。 相似文献
5.
荧光素眼底血管造影在糖尿病视网膜病变诊断中的应用 总被引:4,自引:2,他引:4
荧光素眼底血管造影在糖尿病视网膜病变(DR)诊断中的应用包括对非增殖性糖尿病视网膜病变的早期诊断,认识增殖前期病变,判断是否进入增殖期以及应用对糖尿病黄斑病变进行诊断与分型等.在糖尿病视网膜病变的诊治过程中,合理进行荧光素眼底血管造影检查将会提高对病变的认识和诊治水平. 相似文献
6.
目的了解与循环系统相关眼底病的发病率、年龄增长趋势以及血管造影检查在眼底病诊断中的应用价值.方法对眼科1283例患者进行荧光素眼底血管造影(fundus fluorescein abgiography,FFA)和/或吲哚青绿血管造影检查的资料、眼底病发病部位和性质进行了分组比较.结果在1283例患者中,视网膜血管性疾病700例,占54.5%,平均年龄58.7岁;黄斑部疾病330例,占25.7%,平均年龄54.1岁;炎性眼底病103例,占8%,平均年龄44.02岁.结论随着年龄增长,循环系统疾病的不断增多,眼底病发病率逐渐增高;应用彩色荧光吲哚青绿血管造影有助于眼与全身病的早期确诊和随访. 相似文献
7.
Retinal pigment epithelial detachment, often asymptomatic is a common retinal finding. Multiple serous retinal pigment epithelial detachment especially in a female is very uncommon. We describe a case of multiple retinal pigment epithelial detachments throughout the fundus in a 51-year old female otherwise asymptomatic. Indocyanine green angiography and fundus auto fluorescence showed abnormalities with a normal systemic work-up. This is the first report of an asymptomatic patient correlating angiogram with auto fluorescence in multiple serous retinal pigment epithelial detachments. 相似文献
8.
Jiaju Yang Enke Gu Ting Yan Daoming Shen Bainian Feng Chunlei Tang 《Chemical biology & drug design》2019,93(5):900-909
Free fatty acid 1 (FFA1/GPR40) has attracted extensive attention as a novel target for the treatment of type 2 diabetes for its role in the enhancement of insulin secretion with glucose dependency. Aiming to develop novel potent FFA1 agonists, a new series of phenylpropionic acid derivatives were designed and synthesized on the basis of the modification of chemical cement of TAK‐875, AMG‐837, and LY2881835. Among them, most promising compounds 7 , 14 , and 15 were obtained with EC50 values of 82, 79, and 88 nM, exhibiting a powerful agonistic activity compared to TAK‐875 (95.1 nM). During Oral glucose tolerance test in normal mice, compound 7 , 14 , and 15 had significant glucose‐lowering effect at the dose of 50 mg/kg. Furthermore, compound 15 (50 mg/kg) also significantly improved in glucose tolerance in type 2 diabetic mice. Herein, we reported the discovery and optimization of a series of potent FFA1 agonists. The discovery supported further exploration surrounding this scaffold. 相似文献
9.
10.
Murray AJ Cole MA Lygate CA Carr CA Stuckey DJ Little SE Neubauer S Clarke K 《Journal of molecular and cellular cardiology》2008,44(4):694-700
Heart failure patients have abnormal cardiac high energy phosphate metabolism, the explanation for which is unknown. Patients with heart failure also have elevated plasma free fatty acid (FFA) concentrations. Elevated FFA levels are associated with increased cardiac mitochondrial uncoupling proteins (UCPs), which, in turn, are associated with decreased mitochondrial respiratory coupling and low cardiac efficiency. Here, we determined whether increased mitochondrial UCP levels contribute to decreased energetics in the failing heart by measuring UCPs and respiration in mitochondria isolated from the viable myocardium of chronically infarcted rat hearts and measuring efficiency (hydraulic work/O2 consumption) in the isolated, working rat heart. Ten weeks after infarction, cardiac levels of UCP3 were increased by 53% in infarcted, failing hearts that had ejection fractions less than 45%. Cardiac UCP3 levels correlated positively with non-fasting plasma FFAs (r = 0.81; p < 0.01). Mitochondria from failing hearts were less coupled than those from control hearts, as demonstrated by the lower ADP/O ratio of 1.9 ± 0.1 compared with 2.5 ± 0.2 in controls (p < 0.05). The decreased ADP/O ratio was reflected in an efficiency of 14 ± 2% in the failing hearts when perfused with 1 mM palmitate, compared with 20 ± 1% in controls (p < 0.05). We conclude that failing hearts have increased UCP3 levels that are associated with high circulating FFA concentrations, mitochondrial uncoupling, and decreased cardiac efficiency. Thus, respiratory uncoupling may underlie the abnormal energetics and low efficiency in the failing heart, although whether this is maladaptive or adaptive would require direct investigation. 相似文献