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171.
Subendothelial accumulation of low-density lipoprotein (LDL) in arterial walls is an initiator of atherosclerotic plaque formation. We report here on the correlation between healthy state subendothelial LDL concentration distribution and sites of subsequent plaque formation in coronary arteries of patients with coronary artery disease (CAD). We acquired left (LCA) and right coronary artery (RCA) and atherosclerotic plaque geometries of 60 patients with CAD using dual-source computed tomography angiography. After virtually removing all plaques to obtain an approximation of the arteries' healthy state, we calculated LDL concentration in the artery walls as a function of local lumen-side shear stress. We found that maximum subendothelial LDL concentrations at plaque locations were, on average, 45% (RCA) and 187% (LCA) higher than the respective average subendothelial concentration. Our results demonstrate that locally elevated subendothelial LDL concentration correlates with subsequent plaque formation at the same location.  相似文献   
172.

Objective:

A new tool to quantify visceral adipose tissue (VAT) over the android region of a total body dual‐energy x‐ray absorptiometry (DXA) scan has recently been reported. The measurement, CoreScan, is currently available on Lunar iDXA densitometers. The purpose of the study was to determine the precision of the CoreScan VAT measurement, which is critical for understanding the utility of this measure in longitudinal trials.

Design and Methods:

VAT precision was characterized in both an anthropomorphic imaging phantom (measured on 10 Lunar iDXA systems) and a clinical population consisting of obese women (n = 32).

Results:

The intrascanner precision for the VAT phantom across 9 quantities of VAT mass (0–1,800 g) ranged from 28.4 to 38.0 g. The interscanner precision ranged from 24.7 to 38.4 g. There was no statistical dependence on the quantity of VAT for either the inter‐ or intrascanner precision result (p = 0.670). Combining inter‐ and intrascanner precision yielded a total phantom precision estimate of 47.6 g for VAT mass, which corresponds to a 4.8% coefficient of variance (CV) for a 1 kg VAT mass. Our clinical population, who completed replicate total body scans with repositioning between scans, showed a precision of 56.8 g on an average VAT mass of 1110.4 g. This corresponds to a 5.1% CV. Hence, the in vivo precision result was similar to the phantom precision result.

Conclusions:

The study suggests that CoreScan has a relatively low precision error in both phantoms and obese women and therefore may be a useful addition to clinical trials where interventions are targeted towards changes in visceral adiposity.  相似文献   
173.
In order to assess their accuracy for the determination of glucose during the enzymatic hydrolysis of pretreated lignocellulosic biomass, four different blood glucose monitors (BGMs), each utilizing a different enzymatic mechanism for the determination of glucose, were utilized in an experimental setup, which compares the efficiency of ionic liquid pretreatment with dilute acid and alkaline pretreatments applied on corncob. Among the tested devices, Optium Xceed was found to be the most accurate device for the determination of glucose where Accu-Chek Active was the least accurate BGM, yielding similar results to those obtained with DNS method. Based on the HPLC results, the % error values for Optium Xceed ranged between 3.9-10.5% for the determination of glucose concentration. Upon enzymatic hydrolysis, ionic liquid and alkaline pretreatments gave similar glucose yields, which were slightly higher than the dilute acid pretreatment, which were 31.9%, 31.0% and 27.8%, respectively, based on untreated corncob.  相似文献   
174.
In this study, we aimed to determine the inhibition effects of novel synthesized sulfamates ( 2a–g ), sulfonamides ( 3b–f ), carbonyl sulfonamides ( 3h and i ), and carbonyl sulfamates ( 4h and 4i ), which were tested against two human cytosolic carbonic anhydrase I and II isozymes (hCA I and II) and acetylcholinesterase (AChE) enzyme. For inhibition properties of allylic sulfamates, the half maximal inhibitory concentration (IC50) and inhibition constant (Ki) were calculated for each novel compounds. The allylic sulfamates showed that Ki values are in the range of 187.33–510.31 pM for hCA I, 104.22–290.09 pM against hCA II, and 12.73–103.63 pM against AChE. The results demonstrated that all newly synthesized compounds had shown effective inhibition against hCA I and II isoenzymes and AChE enzyme.  相似文献   
175.
Ginkgo biloba (EGb 761) is a well-defined plant extract that directly scavenges hydroxyl radicals. It is a potent antioxidant that inhibits apoptosis in cultured cells and is effective in treating mild-to-moderate dementia in Alzheimer patients. Apoptosis is an active process of cell destruction and it plays an important role in pathological processes. The aim of this study is to investigate the anti-apoptotic effect of EGb 761 in gossypol-treated human lymphocytes. Pretreatment of lymphocytes with 10 microg/ml EGb 761 for 30 min or 1h decreased the percentage of apoptosis to 17.5% and 20%, respectively. EGb 761 treatment (25-150 microg/ml) decreased the level of apoptosis to a plateau between 8 and 10% of the control values. We conclude that EGb 761 reduces gossypol-induced apoptosis in human lymphocytes.  相似文献   
176.

Germplasm conservation of pineapple [Ananas comosus (L.) Mer.] is crucial to preserve the genus’ genetic diversity, to secure material for genetic improvement and to support innovative and new research. Long-term conservation is accomplished through cryopreservation, that is done by storing cells or tissues at ultra-low temperature in liquid nitrogen (−196 °C). Droplet-vitrification, a combination of droplet freezing and solution-based vitrification, was used to establish a protocol for cryopreservation of pineapple genetic resources. This protocol was tested on cultivated and wild pineapple genotypes to establish a long-term germplasm security duplicate as well as to investigate cryo-injuries in the tissues by means of histological techniques. Excised shoot tips (0.5–1 mm with one primordial leaf) of different pineapple genotypes were precultured for 48 h on solid MS medium containing 0.3 M of sucrose. Three PVS2 exposure times (30, 45 and 60 min) were tested. The results showed high post cryopreservation survival for all genotypes evaluated. The best PVS2 exposure time varied according to genotype, although 45 min gave the best survival for the majority of genotypes. The technique was highly efficient in cryopreserving meristem shoot tips of different pineapple genotypes, and was also less laborious than techniques previously reported. This is a first report on application of the droplet-vitrification technique to diverse genotypes of cultivated and wild pineapples and the first report on histological changes occurring in cryopreserved Ananas tissue.

  相似文献   
177.
The main objective of this investigation is to determine the concentration and accumulation of heavy metals in the coastal sediments of the Southeastern Black Sea of Turkey. The selected sampling area has mainly been affected by anthropogenic activities, such as agricultural, untreated domestic and treated industrial wastewater, and mining. Metal enrichment factor (EF), geo-accumulation index (Igeo), and metal pollution index (MPI) have been calculated and relative contamination levels evaluated at all stations. In this study, the maximum EF values calculated for nickel (Ni), cobalt (Co), cadmium (Cd), lead (Pb), chromium (Cr), arsenic (As), zinc (Zn), and copper (Cu) were 1.4, 3.1, 5.2, 7.8, 7.8, 20, 26, and 42, respectively. Metal pollution has decreased in recent years, but the enrichment of heavy metals has been observed to be relatively high, especially in the uppermost 3-6 cm of the core sample from the Sürmene sampling station, which has been polluted by mining activities. In addition, factor analysis revealed that the coastal sediments from the Eastern Black Sea were influenced by several sources, namely lithogenic and anthropogenic activities (mining, wastewater discharging, agriculture).  相似文献   
178.
Effects of estrogen on the cardiovascular system, mediated mainly by estrogen receptor type alpha (ER alpha), have been well-defined and specific polymorphisms in the ER alpha gene (ESR1) have been associated with several coronary heart diseases including coronary artery disease (CAD) in studies covering different populations. In the present study, we aimed to investigate whether there is an association between two of the known polymorphisms in the ESR1, named c.454-397T>C and c.454-351A>G, and CAD in a Turkish population. One hundred sixty eight patients with CAD and 99 patients without CAD were included in the study. The ESR1 c.454-397T>C and c.454-351A>G polymorphisms were studied by the conventional polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. While no association was found between the c.454-351A>G polymorphism and CAD, the c.454-397T>C genotype distributions were statistically significant independent of known risk factors between CAD-positive (CAD+) and CAD-negative (CAD-) groups (p = 0.001). TT genotype was more frequent in CAD- group than in CAD+ group, 22.2% and 4.8%, respectively. CC genotype was associated with increased risk of CAD (p = 0.001) compared to the TT genotype. When comparing the distribution of CC + TC genotypes to that of TT genotype in CAD+ and CAD- groups, the frequency of CC + TC genotypes showed a significant increase independent of known CAD risk factors in CAD+ subjects (p = 0.001). As a conclusion, a statistically significant relationship between the ESR1 c.454-397T>C polymorphism and CAD were found independent of known CAD risk factors in a Turkish population.  相似文献   
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180.
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