Parameters estimation of the discrete stable distribution

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal

Poly[[[silver(I)-μ-1,4-bis­[(imidazol-1-yl)meth­yl]benzene-κ2 N 3:N 3′-silver(I)-μ-1,4-bis­[(imidazol-1-yl)meth­yl]benzene-κ2 N 3:N 3′] 4,4′-diazenediyldibenzoate] dihydrate]

In the title compound, [Ag2(C14H14N4)2](C14H8N2O4)·2H2O, each of the two unique Ag+ ions is two-coordinated by two N atoms from two different 1,4-bis­[(imidazol-1-yl)meth­yl]benzene ligands in an almost linear fashion [N—Ag—N = 170.34 (10) and 160.25 (10)°]. The 4,4′-diazenediyldibenzoate anions do not coordinate to Ag. O—H⋯O hydrogen bonds stabilize the crystal structure

3,3,3′,3′-Tetra­methyl-6,6′-bis­[(pyridin-4-yl)meth­oxy]-1,1′-spiro­biindane ­monohydrate

The asymmetric unit in the title compound, C33H34N2O2·H2O, consists of a V-shaped mol­ecule and a water mol­ecule to which it is hydrogen bonded. The angle between the mean planes of the two spiro-connected indane groups is 77.06 (5)°. The two five-membered rings of the indane groups have envelope conformations with the methyl­ene atoms adjacent to the spiro C atom forming the flaps. They have deviations from the mean plane of the other four atoms in the rings of 0.374 (4) and 0.362 (4) Å. In the crystal, molecules are linked to form inversion dimers via O—H⋯N hydrogen bonds involving the pyridine N atoms and the solvent water mol­ecule. The dimers are linked into a chain along the b axis by π–π stacking inter­actions between a pyridine ring and its centrosymmetrically related ring in an adjacent dimer. The centroid–centroid distance between the planes is 3.7756 (17) Å, the perpendicular distance is 3.4478 (11) Å and the offset is 1.539 Å

Prediction of large esophageal varices in cirrhotic patients using classification and regression tree analysis

OBJECTIVES: Recent guidelines recommend that all cirrhotic patients should undergo endoscopic screening for esophageal varices. That identifying cirrhotic patients with esophageal varices by noninvasive predictors would allow for the restriction of the performance of endoscopy to patients with a high risk of having varices. This study aimed to develop a decision model based on classification and regression tree analysis for the prediction of large esophageal varices in cirrhotic patients. METHODS: 309 cirrhotic patients (training sample, 187 patients; test sample 122 patients) were included. Within the training sample, the classification and regression tree analysis was used to identify predictors and prediction model of large esophageal varices. The prediction model was then further evaluated in the test sample and different Child-Pugh classes. RESULTS: The prevalence of large esophageal varices in cirrhotic patients was 50.8%. A tree model that was consisted of spleen width, portal vein diameter and prothrombin time was developed by classification and regression tree analysis achieved a diagnostic accuracy of 84% for prediction of large esophageal varices. When reconstructed into two groups, the rate of varices was 83.2% for high-risk group and 15.2% for low-risk group. Accuracy of the tree model was maintained in the test sample and different Child-Pugh classes. CONCLUSIONS: A decision tree model that consists of spleen width, portal vein diameter and prothrombin time may be useful for prediction of large esophageal varices in cirrhotic patient

Exploration and practice of animal physiology teaching mode for top class

动物生理学是动物医学、动物科学专业的重要基础理论课程。针对本校拔尖班学生培养计划和学习特点，本课程在教学中注重情境化教学，把最新研究进展及时整合到相应教学模块中，适当提高过程性评价比例，探索出适合拔尖班学生的授课模式，改善教学效果。Animal physiology is an important basic theoretical course for the specialty of animal medicine and animal science. According to the training programs and learning characteristics of top class students in our college, this course focused on situational teaching, integrated the latest progress manner into teaching model timely, and properly increased the process evaluation proportion in order to explore suitable teaching mode for top-class students, and improve teaching effectiveness

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

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-

A WENO algorithm for radiative transfer with resonant scattering: the time scale of the Wouthuysen-Field Coupling

We develop a numerical solver for the integral-differential equations, which describes the radiative transfer of photon distribution in the frequency space with resonant scattering of Lyalpha photons by hydrogen gas in the early universe. The time-dependent solutions of this equation is crucial to the estimation of the effect of the Wouthuysen-Field (WF) coupling in relation to the 21 cm emission and absorption at the epoch of reionization. The resonant scattering leads to the photon distribution in the frequency space to be piecewise smooth containing sharp changes. The weighted essentially nonoscillatory (WENO) scheme is suitable to handle this problem, as this algorithm has been found to be highly stable and robust for solving Boltzmann equation. We test this numerical solver against analytic solutions of the evolution of the photon distribution in rest background, analytic solution in expanding background without resonant scattering and formation of local Boltzmann distribution around the resonant frequency with the temperature same as that of atom for recoil. We find that evolution of photon distribution undergoes three phases; profile is similar to the initial one, a flat plateau (without recoil) or local Boltzmann distribution (with recoil) forms around the resonant frequency, and finally the distribution around the resonant frequency is saturated when the photons from the source is balanced by the redshift of the expansion. This result indicates that the onset of the W-F coupling should not be determined by the third phase, but by the time scale of the second phase. We found that the time scale of the W-F coupling is equal to about a few hundreds of the mean free flight time of photons with resonant frequency, and is independent of the Sobolev parameter if this parameter is much less than 1.Comment: 20 pages, 13 figure