1,664 research outputs found

    Redetermination of 2,4′-methyl­ene­diphenol

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    In the previous determination [Finn & Musti (1950 ▶). J. Soc. Chem. Ind. (London), 69, S849] of the title compound, C13H12O2, the three-dimensional coordinates and displacement parameters were not reported. This redetermination at room temperature reveals that the dihedral angle between the benzene rings is 79.73 (6)°. In the crystal, inter­molecular O—H⋯O hydrogen bonds between adjacent mol­ecules result in two-dimensional wave-like supra­molecular motifs parallel to the ab plane

    Standard metabolic rate predicts growth trajectory of juvenile Chinese crucian carp (Carassius auratus) under changing food availability

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    Phenotypic traits vary greatly within populations and can have a significant influence on aspects of performance. The present study aimed to investigate the effects of individual variation in standard metabolic rate (SMR) on growth rate and tolerance to food-deprivation in juvenile crucian carp (Carassius auratus) under varying levels of food availability. To address this issue, 19 high and 16 low SMR (individuals were randomly assigned to a satiation diet for 3 weeks, whereas another 20 high and 16 low SMR individuals were assigned to a restricted diet (approximately 50% of satiation) for the same period. Then, all fish were completely food-deprived for another 3 weeks. High SMR individuals showed a higher growth rate when fed to satiation, but this advantage of SMR did not exist in food-restricted fish. This result was related to improved feeding efficiency with decreased food intake in low SMR individuals, due to their low food processing capacity and maintenance costs. High SMR individuals experienced more mass loss during food-deprivation as compared to low SMR individuals. Our results here illustrate context-dependent costs and benefits of intraspecific variation in SMR whereby high SMR individuals show increased growth performance under high food availability but had a cost under stressful environments (i.e., food shortage)

    Current Status and Prevention Strategy for Coal-arsenic Poisoning in Guizhou, China

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    Arsenic exposure from burning coal with high arsenic contents occurs in southwest Guizhou, China. Coal in this region contains extremely high concentrations of inorganic arsenic. Arsenic exposure from coal-burning is much higher than exposure from arsenic-contaminated water in other areas of China. The current status and prevention strategies for arsenic poisoning from burning high-arsenic coal in southwest Guizhou, China, is reported here. Over 3,000 arsenic-intoxicated patients were diagnosed based on skin lesions and urinary arsenic excretion. Non-cancerous toxicities and malignancies were much more common and severe in these patients than in other arsenic-affected populations around the world. The high incidence of cancer and arsenic-related mortality in this cohort is alarming. Chelation therapy was performed but the long-term therapeutic effects are not satisfactory. The best prevention strategy is to eliminate arsenic exposure. Funds from the Chinese Government are currently available to solve this arsenic exposure problem. Strategies include the installation of vented stoves, the use of marsh gas to replace coal, health education, the improvement of nutritional status, and the use of various therapies to treat arsenic-induced skin and liver diseases

    Diaqua­bis­(5-carb­oxy-2-propyl-1H-imidazole-4-carboxyl­ato-κ2 N 3,O 4)cadmium N,N-dimethyl­formamide disolvate

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    In the title complex, [Cd(C8H9N2O4)2(H2O)2]·2C3H7NO, the six-coordinate CdII ion is in a slightly distorted octa­hedral environment, defined by two O atoms from two coordinated water mol­ecules and two carboxyl­ate O atoms and two N atoms from two N,O-bidentate 5-carb­oxy-2-propyl-1H-imidazole-4-carboxyl­ate ligands. In the crystal, complex mol­ecules and dimethyl­formamide solvent mol­ecules are linked by O—H⋯O and N—H⋯O hydrogen bonds into a two-dimensional supra­molecular structure. The propyl groups of the ligands are disordered over two conformations with refined occupancies of 0.680 (7) and 0.320 (7)

    The biological effect of 125I seed continuous low dose rate irradiation in CL187 cells

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    <p>Abstract</p> <p>Background</p> <p>To investigate the effectiveness and mechanism of <sup>125</sup>I seed continuous low-dose-rate irradiation on colonic cell line CL187 in vitro.</p> <p>Methods</p> <p>The CL187 cell line was exposed to radiation of <sup>60</sup>Coγ ray at high dose rate of 2 Gy/min and <sup>125</sup>I seed at low dose rate of 2.77 cGy/h. Radiation responses to different doses and dose rates were evaluated by colony-forming assay. Under <sup>125</sup>I seed low dose rate irradiation, a total of 12 culture dishes were randomly divided into 4 groups: Control group, and 2, 5, and 10 Gy irradiation groups. At 48 h after irradiation, apoptosis was detected by Annexin and Propidium iodide (PI) staining. Cell cycle arrests were detected by PI staining. In order to investigate the influence of low dose rate irradiation on the MAPK signal transduction, the expression changes of epidermal growth factor receptor (EGFR) and Raf under continuous low dose rate irradiation (CLDR) and/or EGFR monoclonal antibodies were determined by indirect immunofluorescence.</p> <p>Results</p> <p>The relative biological effect (RBE) for <sup>125</sup>I seeds compared with <sup>60</sup>Co γ ray was 1.41. Apoptosis rates of CL187 cancer cells were 13.74% ± 1.63%, 32.58% ± 3.61%, and 46.27% ± 3.82% after 2 Gy, 5 Gy, and 10 Gy irradiation, respectively; however, the control group apoptosis rate was 1.67% ± 0.19%. G<sub>2</sub>/M cell cycle arrests of CL187 cancer cells were 42.59% ± 3.21%, 59.84% ± 4.96%, and 34.61% ± 2.79% after 2 Gy, 5 Gy, and 10 Gy irradiation, respectively; however, the control group apoptosis rate was 26.44% ± 2.53%. <it>P </it>< 0.05 vs. control groups by Student's t-test were found in every treated group both in apoptosis and in G<sub>2</sub>/M cell cycle arrest. After low dose rate irradiation, EGFR and Raf expression increased, but when EGFR was blocked by a monoclonal antibody, EGFR and Raf expression did not change.</p> <p>Conclusion</p> <p><sup>125</sup>I seeds resulted in more effective inhibition than <sup>60</sup>Co γ ray high dose rate irradiation in CL187 cells. Apoptosis following G<sub>2</sub>/M cell cycle arrest was the main mechanism of cell-killing effects under low dose rate irradiation. CLDR could influence the proliferation of cells via MAPK signal transduction.</p

    Effects of aminoguanidine on retinal apoptosis in mice with oxygen-induced retinopathy

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    <b>AIM:</b> To explore the protective effects of aminoguanidine (AG) on retinal apoptosis in mice with oxygen-induced retinopathy (OIR).<b>METHODS</b>:A total of 80 C57BL/6J mice, aged 7 days, were randomly divided into four groups:normal, high oxygen, high oxygen saline and high oxygen treated with AG. In the normal group, mice were housed in normoxic conditions from postnatal day P7 to P17. Mice in the other 3 groups were placed under hyperoxic conditions (75±2%O2) in an oxygen-regulated chamber for 5 days and subsequently placed in normoxic conditions for 5 days. Mice in the AG group were treated once daily, from P12 to P17, with AG hemisulfate (100mg/kg body weight, intraperitoneally) dissolved in physiological saline. An equivalent amount of 0.9% physiological saline was administered, as above, to mice in the high oxygen saline group. Ten mice were randomly selected from each group on P14 and on P17, euthanized and the retinas examined. Apoptotic cells in the retina were detected using the terminal-deoxynucleoitidyl transferase mediated nick end labeling (TUNEL) method. The expression of nitric oxide synthase (iNOS) in the retina was detected by immunohistochemistry and changes in rod cells were observed using electron microscopy.<b>RESULTS</b>:TUNEL-positive cells and iNOS immunoreactive neurons were present in the inner nuclear and ganglion cell retinal layers of mice in the high oxygen group. The number of TUNEL-positive cells was significantly greater in the high oxygen group compared with the normal group (<i>t</i>=-20.81, <i>P</i>14d <0.05; <i>t</i>=-15.05, <i>P</i>17d<0.05). However, the number of TUNEL-positive cells in the AG treatment group was significantly lower (<i>t</i>=-13.21, <i>P</i>14d<0.05; <i>t</i>=-6.61,<i>P</i>17d <0.05) compared with the high oxygen group. The expression of iNOS was significantly higher in the high oxygen group compared with the normal group (<i>t</i>=-21.95, <i>P</i>14d<0.05; <i>t</i>=-17.30, <i>P</i>17d<0.05). However, the expression of iNOS in the AG treatment group was significantly lower (<i>t</i>=-12.17,<i>P</i>14d<0.05; <i>t</i>=-10.30,<i>P</i>17d<0.05) compared with the high oxygen group. The outer segments of the rods were disorganized and short in the high oxygen group. Rod morphology appeared to be slightly improved in the AG group.<b>CONCLUSION</b>:AG may protect retinal neurons in OIR by inhibiting apoptosis. The mechanism may be related to iNOS
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