425 research outputs found
5-Chloro-1,3-dimethyl-1H-pyrazole-4-carbaldehyde
In the title compound, C6H7ClN2O, the molecules are situated on mirror planes, so H atoms of two methyl groups were treated as rotationally disordered over two orientations each. The crystal packing exhibits weak intermolecular C—H⋯O interactions and short Cl⋯N contacts of 3.046 (2) Å
Swainsonine reduces 5-fluorouracil tolerance in the multistage resistance of colorectal cancer cell lines
<p>Abstract</p> <p>Background</p> <p>Drug resistance is a major problem in cancer chemotherapy. Acquisition of chemo-resistance not only reduces the effectiveness of drugs, but also promotes side effects and markedly reduces the patient's quality of life. However, a number of resistance mechanisms have been reported and are thought to be the reason for the difficulties in solving drug-resistance problems.</p> <p>Result</p> <p>To investigate the mechanisms of drug resistance, a set of cell lines with different levels of sensitivity and possessing different mechanisms of resistance to 5-fluorouracil (5-FU) was established from a colorectal cancer cell line. The expression of thymidylate synthase, orotic acid phosphoribosyltransferase and dihydropyrimidine dehydrogenase, which are well known to be related to drug resistance, differed among these cell lines, indicating that these cell lines acquired different resistance mechanisms. However, swainsonine, an inhibitor of N-glycan biosynthesis, reduced 5-FU-tolerance in all resistant cells, whereas the sensitivity of the parental cells was unchanged. Further analysis of the N-glycan profiles of all cell lines showed partial inhibition of biosynthesis and no cytotoxicity at the swainsonine dosage tested.</p> <p>Conclusion</p> <p>These observations suggest that N-linked oligosaccharides affect 5-FU resistance more widely than do drug-resistance related enzymes in colorectal cancer cells, and that the N-glycan could be a universal target for chemotherapy. Further, swainsonine may enhance the performance of chemotherapy by reducing tolerance.</p
Parameters in a Class of Leptophilic Dark Matter Models from PAMELA, ATIC and FERMI
In this work we study a class of leptophilic dark matter models, where the
dark matter interacts with the standard model particles via the
gauge boson, to explain the excess in cosmic rays
observed by ATIC and PAMELA experiments, and more recently by Fermi experiment.
There are three types of models: a) , b)
, and c) . Although ATIC or Fermi
data is consistent with PAMELA data separately, ATIC and Fermi data do not
agree with each other. We therefore aim to identify which of the three models
can explain which data set better. We find that models a) and b) can give
correct dark matter relic density and explain the ATIC and PAMELA data
simultaneously recur to the Breit-Wigner enhancement. Whereas model c) with a
larger mass can explain Fermi and PAMELA data simultaneously. In all
cases the model parameters are restricted to narrow regions. Future improved
data will decide which set of data are correct and also help to decide the
correct dark matter model.Comment: Latex 15 pages with 5 figures. Modified to include discussions of
recent Fermi data on the leptophilic models studied in this paper. Title also
modifie
ATIC and PAMELA Results on Cosmic e^\pm Excesses and Neutrino Masses
Recently the ATIC and PAMELA collaborations released their results which show
the abundant e^\pm excess in cosmic rays well above the background, but not for
the \bar{p}. Their data if interpreted as the dark matter particles'
annihilation imply that the new physics with the dark matter is closely related
to the lepton sector. In this paper we study the possible connection of the new
physics responsible for the cosmic e^\pm excesses to the neutrino mass
generation. We consider a class of models and do the detailed numerical
calculations. We find that these models can natually account for the ATIC and
PAMELA e^\pm and \bar{p} data and at the same time generate the small neutrino
masses.Comment: 7 pages, 5 figures. Published version with minor corrections and more
reference
6-Methylpyridine-2(1H)-thione
There are two unique molecules in the asymmetric unit of the title pyridinethione derivative, C6H7NS, each of which adopts the thione rather than the mercaptan form. The rings in both molecules are essentially planar, with maximum deviations from the least-squares planes through all non-H atoms of 0.021 (2) and 0.017 (2) Å. In the crystal structure, the molecules form centrosymmetric cyclic dimers through intermolecular N—H⋯S hydrogen bonds. Additional C—H(methyl)⋯S interactions generate a three-dimensional network
Maladjustment to Academic Life and Employment Anxiety in University Students with Irritable Bowel Syndrome
The present study tested our hypothesis that university students with irritable bowel syndrome (IBS) may experience less satisfactory academic lives than those of students without IBS. We also verified the hypothesis that university students with IBS might have higher employment anxiety than students without IBS might.We conducted a cross-sectional study of 1, 686 university students. Presence or absence of IBS was assessed via the Rome III Questionnaire. Two original items were used to evaluate academic life. The prevalence rates of IBS with diarrhea, IBS with constipation, mixed IBS, and unsubtyped IBS in the study population were 5%, 2%, 10%, and 3%, respectively. Regarding academic life, the proportions of participants who experienced maladjustment and employment anxiety were 29% and 50%, respectively. After adjusting for age, sex, and faculty, the odds ratios for maladjustment and employment anxiety were significantly higher in students who screened positively, relative to those who screened negatively, for IBS (OR, 1.62; 95% CI, 1.24-2.21; OR, 2.16; 95% CI, 1.68-2.81, respectively). In conclusion, maladjustment and anxiety over future employment were higher in university students with IBS relative to those without
Construction of possible integrated predictive index based on EGFR and ANXA3 polymorphisms for chemotherapy response in fluoropyrimidine-treated Japanese gastric cancer patients using a bioinformatic method
Selected genetic and clinical parameters of gastric cancer patients. (XLS 33 kb
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