1,912 research outputs found

    Comparison and analysis of bare soil evaporation models combined with ASTER data in Heihe River Basin

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    AbstractBased on ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) remote sensing data, bare soil evaporation was estimated with the Penman-Monteith model, the Priestley-Taylor model, and the aerodynamics model. Evaporation estimated by each of the three models was compared with actual evaporation, and error sources of the three models were analyzed. The mean absolute relative error was 9% for the Penman-Monteith model, 14% for the Priestley-Taylor model, and 32% for the aerodynamics model; the Penman-Monteith model was the best of these three models for estimating bare soil evaporation. The error source of the Penman-Monteith model is the neglect of the advection estimation. The error source of the Priestley-Taylor model is the simplification of the component of aerodynamics as 0.72 times the net radiation. The error source of the aerodynamics model is the difference of vapor pressure and neglect of the radiometric component. The spatial distribution of bare soil evaporation is evident, and its main factors are soil water content and elevation

    Dimethyl 3,5-diethyl-1H-pyrrole-2,4-dicarboxyl­ate

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    The title pyrrole derivative, C12H17NO4, consists of a pyrrole ring with two diagonally attached meth­oxy­carbonyl groups and two diagonally attached ethyl groups. The two carbonyl groups are approximately in the same plane as the pyrrole ring, making dihedral angles of 3.50 (19) and 6.70 (19)°. In the crystal, adjacent mol­ecules are assembled into dimers in a head-to-head mode by pairs of inter­molecular N—H⋯O hydrogen bonds

    2-Ethyl 4-methyl 5-ethyl-3-methyl-1H-pyrrole-2,4-dicarboxyl­ate

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    The title pyrrole derivative compound, C12H17NO4, was synthesized from methyl 3-oxopenta­noate by a Knorr-type reaction and contains a pyrrole ring to which two diagonal alk­oxy­carbonyl groups and two diagonal alkyl substituents are attached. The methyl­carbonyl and ethyl­carbonyl substituents are approximately co-planar with the pyrrole ring, making dihedral angles of 5.64 (2) and 3.44 (1)°, respectively. In the crystal, adjacent mol­ecules are assembled by pairs of N—H⋯O hydrogen bonds into dimers in a head-to-head mode

    Poly[[hemi-μ4-oxalato-hemi-μ2-oxalato-bis­(μ3-pyrazine-2-carboxyl­ato)erbium(III)silver(I)] monohydrate]

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    The asymmetric unit of the title complex, {[AgEr(C5H3N2O2)2(C2O4)]·H2O}n, contains one ErIII atom, one AgI atom, two pyrazine-2-carboxyl­ate (pyc) ligands, two half oxalate ligands (each lying on an inversion center) and one uncoordinated water mol­ecule. The ErIII atom is coordinated by two O atoms and two N atoms from two pyc ligands, one O atom from a third pyc ligand and four O atoms from two oxalate ligands in a distorted monocapped square-anti­prismatic geometry. The AgI atom is coordinated by two N atoms from two pyc ligands, one O atom from a third pyc ligand and one O atom from one oxalate ligand. The crystal structure exhibits a three-dimensional heterometallic polymeric network. O—H⋯O hydrogen bonding between the uncoordinated water mol­ecule and carboxyl­ate O atoms is observed

    Pholidota chinensis alleviates azoxymethane/dextran sulfate sodium-induced colorectal carcinogenesis through inhibition of TLR4 and COX-2

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    Background: Inflammatory bowel disease (IBD) always progresses to colorectal cancer (CRC) which is the second most frequent cause of death by cancer. It is about 2% of population in the lifetime worldwide who at the risk for development of CRC. Oxaliplatin is an effective anticancer drug used for the treatment of advanced CRC; however, it always causes a robust painful neuropathy. Pholidota chinensis is a Chinese folk herbal medicine which was used for treatment of inflammation such as gastroenteritis, duodenal ulcer and bronchitis.Materials and Methods: The azoxymethane (AOM) and dextran sulfate sodium (DSS) were used to induce the colon tumor of mice. The effect of Pholidota chinensis on colon tumorigenesis was evaluated. Immunohistochemistry and semi-quantitative RT-PCR were used to detect the expression of toll-like receptor 4 (TLR4) and cyclooxygenase-2 (COX-2) in colon.Results: Pholidota chinensis can alleviate the colon tumorigenesis. The prevention effects of Pholidota chinensis are similar to oxaliplatin. Specifically, administration of Pholidota chinensis solution suppresses the expression of the proliferating cell nuclear antigen (PCNA), toll-like receptor 4 (TLR4) and cyclooxygenase-2 (COX-2).Conclusion: Our findings suggested that Pholidota chinensis participate in the regulation of colon cancer development through inhibiting the expression of TLR4 and COX-2.Keywords: Pholidota chinensis; colorectal cancer; Toll-like receptor 4; Cyclooxygenase-

    Protective Effect of Sodium Nitroprusside on the Rat Small Intestine Transplanted Mucosa

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    The intestinal mucosal epithelium is extremely susceptible to even brief periods of ischemia. Mucosal barrier damage, which is associated with ischemia/reperfusion (I/R) injury and consequently bacterial translocation, remains a major obstacle for clinically successful small bowel transplantation (SBT). Previous studies have demonstrated a protective effect of nitric oxide (NO) on other transplanted organs and NO mediated intestinal protection has also been reported in vitro. The aim of this study was to evaluate the effect of sodium nitroprusside (SNP), NO donor, on graft mucosal histology and molecular markers of function after SBT in rats. We used SNP in different period of heterotopic SBT rats. The groups consisted of SBT, pre-SNP group, and post-SNP group. Interestingly, the pre-SNP graft samples exhibited less damage compared to the SBT and post-SNP samples. In addition, mucosal samples from the pre-SNP group showed higher Na+-K+-ATPase activity and higher levels of laminin expression compared to the SBT and post-SNP samples. The findings of the present study reveal that SNP given before graft ischemia/reperfusion injury has a protective effect on mucosal histology and molecular markers of function in the transplanted small intestine

    Intensity-modulated Radiation Therapy Versus Para-aortic Field Radiotherapy to Treat Para-aortic Lymph Node Metastasis in Cervical Cancer: Prospective Study

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    Aim To compare dosimetry, efficacy, and toxicity of intensity- modulated radiation therapy (IMRT) with para-aortic field radiotherapy in patients with para-aortic lymph node (PALN) metastasis of cervical cancer. Methods This prospective study examined 60 patients with cervical cancer with PALN metastasis who underwent whole-pelvis radiotherapy followed by brachytherapy between November 1, 2004 and May 31, 2008. After 3 cycles of chemotherapy, patients were serially allocated into two groups and treated with IMRT or para-aortic field RT at doses of 58-68 Gy and 45-50 Gy, respectively. Treatment response was evaluated and toxicities were assessed. Patients in the IMRT group were treated with both para-aortic field RT and IMRT in order to compare the exposure dose of organs at risk. Results In the IMRT group, the mean dose delivered to the planning target volume was 67.5 Gy. At least 99% of the gross tumor volume received effective coverage and radical dose (median, 63.5 Gy; range, 54.5-66) during treatment. IMRT plans yielded better dose conformity to the target and better sparing of the spinal cord and small intestine than para-aortic field RT. The IMRT patients experienced less acute and chronic toxicities. The IMRT group also had higher 2- and 3-year survival rates than the para-aortic RT group (2-year, 58.8% vs 25.0%, P = 0.019; 3-year, 36.4% vs 15.6%, P = 0.016). However, no significant difference was found in 1-year survival (67.7% vs 51.3%, P =0.201). The median survival in the IMRT group was 25 months (range, 3 to 37 months). The actuarial overall survival, disease-free survival, and locoregional control rates at 2 years were 67%, 77%, and 88%, respectively, in the IMRT group. Conclusions IMRT provides better clinical outcomes than para-aortic field radiotherapy in patients with PALN metastasis. However, cervical local and distal recurrence remain a problem. Long-term follow-up and studies involving more patients are needed to confirm our results

    PHOLIDOTA CHINENSIS ALLEVIATES AZOXYMETHANE/DEXTRAN SULFATE SODIUM-INDUCED COLORECTAL CARCINOGENESIS THROUGH INHIBITION OF TLR4 AND COX-2

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    Inflammatory bowel disease (IBD) always progresses to colorectal cancer (CRC) which is the second most frequent cause of death by cancer. It is about 2% of population in the lifetime worldwide who at the risk for development of CRC. Oxaliplatin is an effective anticancer drug used for the treatment of advanced CRC, however, it always causes a robust painful neuropathy. Pholidota chinensis is a Chinese folk herbal medicine which was used for treatment of inflammation such as gastroenteritis, duodenal ulcer and bronchitis. In the present study, we examined the role of Pholidota chinensis in inflammation-related colon tumorigenesis which was induced by azoxymethane (AOM)/dextran sulfate sodium (DSS) in mice. We found that Pholidota chinensis can alleviate the colon tumorigenesis. The prevention effects of Pholidota chinensis is similar to oxaliplatin. Specifically, administration of Pholidota chinensis solution suppresses the expression of the proliferating cell nuclear antigen (PCNA), toll-like receptor 4 (TLR4) and cyclooxygenase-2 (COX-2). Our findings suggested that Pholidota chinensis participate in the regulation of colon cancer development through inhibiting the expression of TLR4 and COX-2
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