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The changes in capacitance and conductance of lipid bilayer membranes have been studied with adsorbed membrane fragments containing Na+,K+-ATPase. These changes have been initiated by fast release of protons from a bound form (“caged H+”) induced by an UV flash. The changes of the capacitance in the presence of Na+,K+-ATPase were affected by the frequency of the applied voltage, pH and the concentration of sodium ions. Addition of sodium ions altered the changes of capacitance caused by a pH jump in the medium due to caged H+ photolysis, and the magnitude and sign of this effect depended on the initial pH. These results are explained by competitive binding of sodium ions and protons to the ion-binding sites of the Na+,K+-ATPase at its cytoplasmic side. The pH at which the sign of the sodium ion effect changed allows the evaluation of the pK of the proton binding site, which is about 7.6.  相似文献   
145.
Seven strains of the causative agent of Lyme borreliosis have been isolated from ticks of the species Ixodes ricinus (L.) obtained at the territories of Leningrad Province, Lithuania and Czechoslovakia. The strains have been studied in reactions with 5 types of monoclonal antibodies. All isolated strains belong to serotype II according to Barbour's system and are typical for European strains.  相似文献   
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The aim of the present study is to assess the possible protective effects of thymol and carvacrol against cisplatin (CP)‐induced nephrotoxicity. A single dose of CP {6 mg/kg, intraperitoneally (i.p.)} injected to male rats revealed significant increases in serum urea, creatinine, and tumor necrosis factor alpha levels. It also increased kidney contents of malondialdehyde and caspase‐3 activity with significant reduction in serum albumin, kidney content of reduced glutathione as well as catalase, and superoxide dismutase activity as compared to that of the control group. In contrast, administration of thymol {20 mg/kg, orally (p.o.)} and/or carvacrol (15 mg/kg, p.o.) for 14 days before CP injection and for 7 days after CP administration restored the kidney function and examined oxidative stress parameters. In conclusion, thymol was more effective nephroprotective than carvacrol. Moreover, a combination of thymol and carvacrol had a synergistic nephroprotective effect that might be attributed to antioxidant, anti‐inflammatory, and antiapoptotic activities.  相似文献   
147.
The effect of deep hypothermia on the rat's organism was investigated without the use of hypercapnic hypoxia or administration of medicine. The possibility of resuscitation and rehabilitation of rats after deep hypothermia depending on different rate of heating have been also studied. It has been observed that the cardiac activity stopped at about 3 degrees C. We supposed that the extremely intensive heating and temperature rise of an organism were both limiting factors. We have discovered that the low intensity of heating was the next factor of limitation which was connected with the duration of clinical death. These experiments showed that the intensive cooling and heating (about 0.4 degrees C per min.) are the best for resuscitation and rehabilitation after deep hypothermia.  相似文献   
148.

Background

Breast cancer survivors, particularly those treated with chemotherapy, are at significantly increased risk for long-term cognitive and neurobiologic impairments. These deficits tend to involve skills that are subserved by distributed brain networks. Additionally, neuroimaging studies have shown a diffuse pattern of brain structure changes in chemotherapy-treated breast cancer survivors that might impact large-scale brain networks.

Methods

We therefore applied graph theoretical analysis to compare the gray matter structural networks of female breast cancer survivors with a history of chemotherapy treatment and healthy age and education matched female controls.

Results

Results revealed reduced clustering coefficient and small-world index in the brain network of the breast cancer patients across a range of network densities. In addition, the network of the breast cancer group had less highly interactive nodes and reduced degree/centrality in the frontotemporal regions compared to controls, which may help explain the common impairments of memory and executive functioning among these patients.

Conclusions

These results suggest that breast cancer and chemotherapy may decrease regional connectivity as well as global network organization and integration, reducing efficiency of the network. To our knowledge, this is the first report of altered large-scale brain networks associated with breast cancer and chemotherapy.  相似文献   
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Background  

Monetary incentives are an effective way of increasing response rates to surveys, though they are generally less effective in physicians, and are more effective when the incentive is paid up-front rather than when made conditional on completion.  相似文献   
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