Bis[tris(tetrahydrofuran)lithium(1+)] bis(μ-diphenylphosphanido)bis(tetra-carbonylmolybdate)(2–)

In the dianion [Mo2(/z-PPh2)2(CO)8] 2-, two Mo centres are 4.100 (1)/ apart and are bridged asymmetrically by two diphenylphosphanido ligands. Each metal atom is also coordinated by four terminal CO ligands. There are strong interactions between the dianion and the two [Li(thf)3] + cations (thf = C4HsO). The Li ions are ligated by one equatorial carbonyl O atom from each Mo centre.published_or_final_versio

A threshold approach for peaks-over-threshold modeling using maximum product of spacings

We propose a threshold model extending the generalized Pareto distribution for exceedances over a threshold. The threshold is solely determined within the model and is shown to be super-consistent under the maximum product of spacings estimation method. We apply the model to some insurance data and demonstrate the merit of having a full parametric model for the entire data set.published_or_final_versio

A note on the estimation of extreme value distributions using maximum product of spacings

published_or_final_versio

Testing for double threshold autoregressive conditional heteroscedastic model

The testing problem for the hypothesis of linearity against the double threshold autoregressive conditional heteroscedastic model is addressed. The, problem is nonstandard as the threshold parameter is a nuisance parameter which is absent under the null hypothesis. We will show that the asymptotic null distribution of the Lagrange-multiplier test statistic is a functional of a zero-mean Gaussian process. In some cases, we give the upper percentage points of the test statistic. The performance of the test statistic is illustrated by extensive simulation experiments and an example.published_or_final_versio

Test for homogeneity in gamma mixture models using likelihood ratio

postprin

Descriptive Anatomy and Three-Dimensional Reconstruction of the Skull of the Early Tetrapod Acanthostega gunnari Jarvik, 1952

The early tetrapod Acanthostega gunnari is an iconic fossil taxon exhibiting skeletal morphology reflecting the transition of vertebrates from water onto land. Computed tomography data of two Acanthostega skulls was segmented using visualization software to digitally separate bone from matrix and individual bones of the skull from each other. A revised description of cranial and lower jaw anatomy in this taxon based on CT data includes new details of sutural morphology, the previously undescribed quadrate and articular bones, and the mandibular symphysis. Sutural morphology is used to infer loading regime in the skull during feeding, and suggests Acanthostega used its anterior jaws to initially seize prey while smaller posterior teeth were used to restrain struggling prey during ingestion. Novel methods were used to repair and retrodeform the skull, resulting in a three-dimensional digital reconstruction that features a longer postorbital region and more strongly hooked anterior lower jaw than previous attempts while supporting the presence of a midline gap between the nasals and median rostrals

Metformin Use and Gastric Cancer Risk in Diabetic Patients After Helicobacter pylori Eradication

Background: Although prior studies showed metformin could reduce gastric cancer (GC) risk in patients with diabetes mellitus (DM), they failed to adjust for Helicobacter pylori infection and glycemic control. We aimed to investigate whether metformin reduced GC risk in H. pylori -eradicated diabetic patients and its association with glycemic control. Methods: This was a territory-wide cohort study using hospital registry database, recruiting all diabetic patients who were prescribed clarithromycin-based triple therapy for H. pylori infection from 2003 to 2012. Subjects were observed from H. pylori therapy prescription until GC diagnosis, death or end of study (December 2015). Exclusion criteria included GC diagnosed within first year of H. pylori therapy, prior history of GC or gastrectomy, and failure of H. pylori eradication. The hazard ratio (HR) of GC with metformin (defined as at least 180-day use) was estimated by Cox model with propensity score adjustment for covariates (age, sex, comorbidities, medications [including insulin], and time-weighted average hemoglobin A1c [HbA1c]). All statistical tests were two-sided. Results: During a median follow-up of 7.1 years (IQR:4.7–9.8), 37 (0.51%) of 7,266 diabetic patients developed GC at a median age of 76.4 years (IQR: 64.8–81.5 years). Metformin use was associated with a reduced GC risk (adjusted HR:0.49; 95% CI:0.24–0.98). There was a trend towards a lower GC risk with increasing duration (ptrend =0.01) and dose of metformin (ptrend=0.02) HbA1c level was not an independent risk factor for GC. Conclusions: Metformin use was associated with a lower GC risk among H. pylori -eradicated diabetic patients in a duration- and dose-response manner, which was independent of HbA1c level

Chinese red yeast rice (Monascus purpureus-fermented rice) promotes bone formation

<p>Abstract</p> <p>Background</p> <p>Statin can induce the gene expression of bone morphogenetic protein-2. Red yeast rice (RYR, <it>Hongqu</it>), <it>i.e</it>. rice fermented with <it>Monascus purpureus</it>, contains a natural form of statin. This study demonstrates the effects of RYR extract on bone formation.</p> <p>Methods</p> <p>Bone defects were created in the parietal bones of two New Zealand white rabbits. In the test animal, two defects were grafted with collagen matrix mixed with RYR extract. In the control animal, two defects were grafted with collagen matrix alone. UMR 106 cell line was used to test RYR extract <it>in vitro</it>. In the control group, cells were cultured for three durations (24 hours, 48 hours and 72 hours) without any intervention. In the RYR group, cells were cultured for the same durations with various concentrations of RYR extract (0.001 g/ml, 0.005 g/ml and 0.01 g/ml). Bicinchoninic acid (BCA) assay, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and alkaline phosphatase (ALP) assay were performed to measure total protein, mitochondrial activity and bone cell formation respectively.</p> <p>Results</p> <p>The test animal showed more formation of new bone in the defects than the control animal. RYR significantly increased the optical density in the MTT assay and ALP activity <it>in vitro</it>.</p> <p>Conclusion</p> <p>RYR extract stimulated new bone formation in bone defects <it>in vivo </it>and increased bone cell formation <it>in vitro</it>.</p

Helicobacter pylori associated gastric intestinal metaplasia: Treatment and surveillance

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ACE (Angiotensin-Converting Enzyme) Inhibitors/Angiotensin Receptor Blockers Are Associated With Lower Colorectal Cancer Risk: A Territory-Wide Study With Propensity Score Analysis

Whether ACE (angiotensin-converting enzyme) inhibitors and angiotensin receptor blockers modify colorectal cancer risk remains controversial. We aimed to determine association between their use and colorectal cancer risk after a negative baseline colonoscopy. This is a territory-wide retrospective cohort study recruiting patients aged ≥40 who had undergone colonoscopy between 2005 and 2013. Exclusion criteria included colorectal cancer detected 3years (adjusted hazard ratio, 1.18 [95% CI, 0.88-1.57]); every single year increase in the drug use was associated with 5% reduction in adjusted hazard ratio risk. ACE inhibitors/angiotensin receptor blocker were associated with a lower colorectal cancer risk in a duration-response manner