752 research outputs found
Lactulose: an effective preventive and therapeutic option for ischemic stroke by production of hydrogen
Lactulose, a synthetic sugar not able to be digested and absorbed by human beings, is widely used to treat constipation and hepatic encephalopathy clinically. Through fermentation by the bacteria in the gastrointestinal tract, lactulose can produce considerable amount of hydrogen, which is protective for ischemic stroke as a unique antioxidant. We propose that lactulose can induce the production of endogenous hydrogen that in turn reduces oxidative stress and ameliorate the stroke damage in human beings
Three-Layered Atmospheric Structure in Accretion Disks Around Stellar-Mass Black Holes
Modeling of the x-ray spectra of the Galactic superluminal jet sources GRS
1915+105 and GRO J1655-40 reveal a three-layered atmospheric structure in the
inner region of their accretion disks. Above the cold and optically thick disk
of a temperature 0.2-0.5 keV, there is a warm layer with a temperature of
1.0-1.5 keV and an optical depth around 10. Sometimes there is also a much
hotter, optically thin corona above the warm layer, with a temperature of 100
keV or higher and an optical depth around unity. The structural similarity
between the accretion disks and the solar atmosphere suggest that similar
physical processes may be operating in these different systems.Comment: 5 fives, 2 figures, 1 table. The online version of the paper in
Science may be accessed through http://jet.uah.edu/~zhangsn/papers.htm
Glomerular Organization of the Antennal Lobes of the Diamondback Moth, Plutella xylostella L.
The antennal lobe of the moth brain is the primary olfactory center processing information concerning pheromones and plant odors. Plutella xylostella is a major worldwide pest of cruciferous vegetables and its behavior is highly dependent on their olfactory system. However, detailed knowledge of the anatomy and function of the P. xylostella olfactory system remains limited. In the present study, we present the 3-Dimentional (3-D) map of the antennal lobe of P. xylostella, based on confocal microscopic analysis of glomerular segmentation and Neurobiotin backfills of Olfactory Receptor Neurons (ORNs). We identified 74–76 ordinary glomeruli and a macroglomerular complex (MGC) situated at the entrance of the antennal nerve in males. The MGC contained three glomeruli. The volumes of glomeruli in males ranged from 305.83 ± 129.53 to 25440.00 ± 1377.67 μm3. In females, 74–77 glomeruli were found, with the largest glomerulus ELG being situated at the entrance of the antennal nerve. The volumes of glomeruli in females ranged from 802.17 ± 95.68 to 8142.17 ± 509.46 μm3. Sexual dimorphism was observed in anomalous supernumerary, anomalous missing, shape, size, and array of several of the identified glomeruli in both sexes. All glomeruli, except one in the antennal lobe (AL), received projections of antennal ORNs. The glomeruli PV1 in both sexes received input from the labial palp nerve and was assumed as the labial pit organ glomerulus (LPOG). These results provide a foundation for better understanding of coding mechanisms of odors in this important pest insect
Stable hZW10 kinetochore residency, mediated by hZwint-1 interaction, is essential for the mitotic checkpoint
The mitotic checkpoint is an essential surveillance mechanism that ensures high fidelity chromosome segregation during mitosis. Mitotic checkpoint function depends on numerous kinetochore proteins, including ZW10, ROD, and Zwilch (the ROD–ZW10–Zwilch complex). Through an extensive mutagenesis screen of hZW10, we have mapped the kinetochore localization domain of hZW10 as well as the hZwint-1 interaction domain. We find that hZwint-1–noninteracting mutants still localize to kinetochores. In addition, using fluorescence recovery after photobleaching, we have found that hZW10 residency at metaphase kinetochores is brief (half-time of 13 s). However, during prometaphase or at unattached kinetochores, enhanced green fluorescent protein–hZW10 becomes a stable component of the kinetochore. Moreover, we find that stable hZW10 kinetochore residency at prometaphase kinetochores is dependent on its interaction with hZwint-1, and is essential for mitotic checkpoint arrest
Consumption of Hydrogen Water Reduces Paraquat-Induced Acute Lung Injury in Rats
Exposure to paraquat leads to acute lung injury and oxidative stress is widely accepted as a contributor to paraquat-induced acute lung injury. Recent studies have reported that consumption of water with dissolved molecular hydrogen to a saturated level (hydrogen water) prevents oxidative stress-induced diseases. Here, we investigated whether consumption of saturated hydrogen saline protects rats against paraquat-induced acute lung injury. Adult male Sprague-Dawley (SD) rats were randomly divided into four groups: Control group; hydrogen water-only group (HW group); paraquat-only group (PQ group); paraquat and hydrogen water group (PQ + HW group). The rats in control group and HW group drank pure water or hydrogen water; the rats in PQ group and PQ + HW group were intraperitonealy injected with paraquat (35 mg/kg) and then provided pure water or hydrogen water. Both biochemical and histological lung alterations were measured. The results showed that hydrogen water ameliorated these alterations, demonstrating that hydrogen water alleviated paraquat-induced acute lung injury possibly by inhibition of oxidative damage
Synthesis and spectroscopic calf thymus deoxyribonucleic acid binding investigations of luteolin – zinc(II) complex
196-201A luteolin–zinc(II) (lut–Zn) complex has been synthesized by the reaction of luteolin with copper acetate in alcohol. The binding mode of lut–Zn with calf thymus deoxyribonucleic acid (ctDNA) is studied by different spectroscopic methods in pH 7.4 tris(hydroxymethyl)aminomethane–HCl (Tris–HCl) buffer solution. Ultraviolet (UV)–visible absorption spectrophotometry and fluorescence spectroscopy as well as viscosity measurements have proved the formation of lut–Zn–ctDNA complex. Binding constant (Ka) of lut–Zn–ctDNA complex is 4.29 × 104 L mol-1 (310 K). Fluorophotometry measurements has proved that the quenching mechanism of fluorescence of acridine orange (AO)–ctDNA by lut–Zn is static quenching. The thermodynamic parameters entropy change (ΔS), enthalpy change (ΔH) and Gibbs free energy (ΔG) of binding reaction are calculated to be -20.87 J K-1 mol -1, -3.39 × 104 J mol-1 and -2.74 × 104 J mol-1 at 310 K, respectively. Negative values of ΔH and ΔS have indicated that there are hydrogen bonds and van der Waals forces in the binding reaction of lut–Zn with ctDNA. The fluorescence results and UV–visible absorption together have revealed that the interaction mode of lut–Zn to ctDNA is an intercalation mode. This conclusion is further confirmed by viscosity measurements
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