bluuebunny/crossref_metadata_2025_split huggingface dataset:
New ketomethylene inhibitor analogues: synthesis and assessment of structural determinants for N-domain selective inhibition of angiotensin-converting enzyme
Authors: Sharma Rajni K. , Douglas Ross G. , Louw Stefan , Chibale Kelly , Sturrock Edward D. 
Published: May 2012

Abstract
Angiotensin-converting enzyme (ACE) is a zinc metallopeptidase containing two homologous domains. While the C-domain plays a major role in blood pressure regulation, the N-domain hydrolyzes the antifibrotic agent N-acetyl-Ser-Asp-Lys-Pro. Thus, N-domain selective (N-selective) inhibitors could be useful in the treatment of conditions relating to excessive tissue fibrosis. New keto-ACE analogues were designed that contained functionalities considered important for N-selective inhibitor RXP407 binding, namely, a P2 Asp, N-acetyl group, and C-terminal amide. Such functionalities were incorporated to assess the structural determinants for N-selective binding in a novel inhibitor template. Inhibitors containing a C-terminal amide and modified P2′ group were poor inhibitors of the N-domain, with several of these displaying improved inhibition of the C-domain. Molecules with both a C-terminal amide and P2 Asp were also poor inhibitors and not N-selective. Compounds containing a free C-terminus, a P2 Asp and protecting group displayed a change of more than 1000-fold N-selectivity compared with the parent molecule. Molecular docking models revealed interaction of these P2 groups with S2 residues Tyr369 and Arg381. This study emphasizes the importance of P2 functionalities in allowing for improved N-selective binding and provides further rationale for the design of N-selective inhibitors, which could be useful in treating tissue fibrosis.
The inverse spectral problem for the Sturm–Liouville
operator with discontinuous potential
Authors: Sedipkov Aydys A. 
Published: May 2012

Abstract.
We study the inverse spectral problem for the Sturm–Liouville
operator with discontinuous potential. We establish properties of
the Jost function and investigate the inverse problem of recovering
the operator from given the Jost function. We obtain a procedure for
constructing the solution of the inverse problem.
Preparation and properties of melt blended metallocene polyethylene/silica nanocomposites: modifier effects
Authors: Lai Sun-Mou , Hsieh Meng-Ling , Chou Feng Yi , Chen Wen-Ching 
Published: May 2012

Abstract
Metallocene polyethylene (mPE)/silica ternary nanocomposites were prepared via a melt mixing approach using two types of modifiers, mPE-g-MA (maleic anhydride) or linear low density polyethylene (LLDPE)-g-MA. Transmission electron microscopy revealed a similar degree of silica dispersion status for mPE/silica with or without modifiers to suggest the similar compatibility for mPE with modified silica, as evidenced by a similar change on the master curves over the corresponding frequency range and silica content in Cole-Cole plots. Silica and the modifiers served as nucleating agents to increase the crystallization temperature of mPE. Two visible crystallization temperatures or melting temperatures corresponding to mPE and LLDPE-g-MA, respectively, were still observable for LLDPE-g-MA modified cases, but not for mPE-g-MA modified cases. LLDPE-g-MA modified cases rendered the highest Young’s modulus and cutting strength due to the induced yielding from the high crystalline LLDPE-g-MA. Cutting strength of the LLDPE-g-MA modified case was approximately 34% larger than that of the mPE-g-MA modified case at 10 phr silica. By contrast, mPE-g-MA modified cases rendered the highest tear strength due to its high flexibility to provide more physical entanglements. Strength of investigated nanocomposites varied under different deformation behaviors to signify the importance of interphase and matrix variation at similar silica dispersion status.
Influence of MMT as reinforcement on rheological behavior, mechanical and morphological properties of recycled PET/ABS thermoplastic nanocomposites
Authors: Razak Mohd Zahidfullah Abd , Arsad Agus , Rahmat Abdul Razak , Hassan Azman 
Published: May 2012

Abstract
The objective of this research was to investigate the effect of incorporating nanofiller, montmorillonite (MMT) on mechanical, morphological and rheological properties of acrylonitrile-butadiene-styrene (ABS) and recycled poly(ethylene terephthalate) (rPET) nanocomposites. The MMT contents in 70:30 ABS/rPET and 30:70 ABS/rPET ranged from 1 to 5 wt%. The ABS/rPET nanocomposites were extruded and injection-molded into tensile, flexural and impact test samples. Samples underwent rheological testing by using melt flow index (MFI) and capillary rheometer and the morphology of the nanocomposites was investigated by using field emission scanning electron microscopy (FESEM). The maximum tensile strength and flexural strength were at 1 wt.% of MMT for both blends. However, tensile modulus and flexural modulus reached maximum point at 3 wt.% and started to decrease beyond 3 wt.%% of MMT. Impact strength for both blending decreased significantly with the incorporation of MMT. MFI values decreased with the increment of MMT for 30:70 ABS/rPET, but increased for 70:30 ABS/rPET. The incorporation of MMT increased the melt strength of 30:70 ABS/rPET nanocomposites. Shear viscosity showed increment with the increasing MMT concentration for 30:70 ABS/rPET nanocomposites. However, shear viscosity decreased with the increment of MMT for 70:30 ABS/rPET. FESEM micrographs show good distribution and dispersion of MMT in 30:70 ABS/rPET, but poor dispersion and agglomeration of MMT in 70:30 ABS/rPET.
The unusual creep and relaxation behaviour of polypropylene
Authors: Dusunceli Necmi 
Published: May 2012

Abstract
This paper focuses on experimental investigation and modelling of the unusual creep and relaxation behaviour of polypropylene. A polypropylene specimen was loaded up to three different levels of maximum strain (ɛmax), unloaded to various minimum stresses (σmin), creep and relaxation tests were performed at seven different strain levels. In addition to investigate the effect of loading history on unloading paths, multiple creep experiments were conducted at various stress levels. It was observed that unusual creep and relaxation behaviour of polypropylene depended on a strain increment (Δɛ) which is the difference between the minimum (ɛmin) and maximum strain level (ɛmax). Increasing the strain increment affects the creep and relaxation behaviour on loading path. As a result, the creep and relaxation behaviours of polypropylene show non-monotonic characteristics. The viscoplasticity theory based on overstress for polymer (VBOP) model was used to model the unusual creep and relaxation behaviour of polypropylene. From the comparison between the VBOP model predictions and the experimental results, it can be seen that the VBOP model can model both the unusual creep and relaxation behaviours of a semicrystalline polymer.
Sex Modifies Genetic Effects on Residual Variance in Urinary Calcium Excretion in Rat (Rattus norvegicus)
Authors: Perry Guy M L , Nehrke Keith W , Bushinsky David A , Reid Robert , Lewandowski Krista L , Hueber Paul , Scheinman Steven J 
Published: May 2012

AbstractConventional genetics assumes common variance among alleles or genetic groups. However, evidence from vertebrate and invertebrate models suggests that residual genotypic variance may itself be under partial genetic control. Such a phenomenon would have great significance: high-variability alleles might confound the detection of “classically” acting genes or scatter predicted evolutionary outcomes among unpredicted trajectories. Of the few works on this phenomenon, many implicate sex in some aspect of its control. We found that female genetic hypercalciuric stone-forming (GHS) rats (Rattus norvegicus) had higher coefficients of variation (CVs) for urinary calcium (CV = 0.14) than GHS males (CV = 0.06), and the reverse in normocalciuric Wistar–Kyoto rats (WKY) (CV♂ = 0.14; CV♀ = 0.09), suggesting sex-by-genotype interaction on residual variance. We therefore investigated the effect of sex on absolute-transformed residuals in urinary calcium in an F2 GHS × WKY mapping cohort. Absolute residuals were associated with genotype at two microsatellites, D3Rat46 (RNO3, 33.9 Mb) and D4Mgh1 (RNO4, 84.8 MB) at Bonferroni thresholds across the entire cohort, and with the microsatellites D3Rat46, D9Mgh2 (RNO9, 84.4 Mb), and D12Rat25 (RNO12, 40.4 Mb) in females (P &lt; 0.05) but not males. In GHS chromosome 1 congenic lines bred onto a WKY genomic background, we found that congenic males had significantly (P &lt; 0.0001) higher CVs for urinary calcium (CV = 0.25) than females (CV = 0.15), supporting the hypothesis of the inheritance of sex-by-genotype interaction on this effect. Our findings suggest that genetic effects on residual variance are sex linked; heritable, sex-specific residuals might have great potential implications for evolution, adaptation, and genetic analysis.
Genetics and Evolution of Hybrid Male Sterility in House Mice
Authors: White Michael A , Stubbings Maria , Dumont Beth L , Payseur Bret A 
Published: May 2012

Abstract
Comparative genetic mapping provides insights into the evolution of the reproductive barriers that separate closely related species. This approach has been used to document the accumulation of reproductive incompatibilities over time, but has only been applied to a few taxa. House mice offer a powerful system to reconstruct the evolution of reproductive isolation between multiple subspecies pairs. However, studies of the primary reproductive barrier in house mice—hybrid male sterility—have been restricted to a single subspecies pair: Mus musculus musculus and Mus musculus domesticus. To provide a more complete characterization of reproductive isolation in house mice, we conducted an F2 intercross between wild-derived inbred strains from Mus musculus castaneus and M. m. domesticus. We identified autosomal and X-linked QTL associated with a range of hybrid male sterility phenotypes, including testis weight, sperm density, and sperm morphology. The pseudoautosomal region (PAR) was strongly associated with hybrid sterility phenotypes when heterozygous. We compared QTL found in this cross with QTL identified in a previous F2 intercross between M. m. musculus and M. m. domesticus and found three shared autosomal QTL. Most QTL were not shared, demonstrating that the genetic basis of hybrid male sterility largely differs between these closely related subspecies pairs. These results lay the groundwork for identifying genes responsible for the early stages of speciation in house mice.
Age-Specific Variation in Immune Response inDrosophila melanogasterHas a Genetic Basis
Authors: Felix Tashauna M , Hughes Kimberly A , Stone Eric A , Drnevich Jenny M , Leips Jeff 
Published: May 2012

AbstractImmunosenescence, the age-related decline in immune system function, is a general hallmark of aging. While much is known about the cellular and physiological changes that accompany immunosenescence, we know little about the genetic influences on this phenomenon. In this study we combined age-specific measurements of bacterial clearance ability following infection with whole-genome measurements of the transcriptional response to infection and wounding to identify genes that contribute to the natural variation in immunosenescence, using Drosophila melanogaster as a model system. Twenty inbred lines derived from nature were measured for their ability to clear an Escherichia coli infection at 1 and 4 weeks of age. We used microarrays to simultaneously determine genome-wide expression profiles in infected and wounded flies at each age for 12 of these lines. Lines exhibited significant genetically based variation in bacterial clearance at both ages; however, the genetic basis of this variation changed dramatically with age. Variation in gene expression was significantly correlated with bacterial clearance ability only in the older age group. At 4 weeks of age variation in the expression of 247 genes following infection was associated with genetic variation in bacterial clearance. Functional annotation analyses implicate genes involved in energy metabolism including those in the insulin signaling/TOR pathway as having significant associations with bacterial clearance in older individuals. Given the evolutionary conservation of the genes involved in energy metabolism, our results could have important implications for understanding immunosenescence in other organisms, including humans.
The Effect of Age on Delay in Diagnosis and Stage of Breast Cancer
Authors: Partridge Ann H. , Hughes Melissa E. , Ottesen Rebecca A. , Wong Yu-Ning , Edge Stephen B. , Theriault Richard L. , Blayney Douglas W. , Niland Joyce C. , Winer Eric P. , Weeks Jane C. , Tamimi Rulla M. 
Published: May 2012

AbstractBackground.Young women with breast cancer are more likely to present with more advanced disease and are more likely to die as a result of breast cancer than their older counterparts. We sought to examine the relationship among young age (≤40 years), the likelihood of a delay in diagnosis, and stage.Methods.We examined data from women with newly diagnosed stage I–IV breast cancer presenting to one of eight National Comprehensive Cancer Network centers in January 2000 to December 2007. Delay in diagnosis was defined as time from initial sign or symptom to breast cancer diagnosis &gt;60 days.Results.Among 21,818 women with breast cancer eligible for analysis, 2,445 were aged ≤40 years at diagnosis. Young women were not more likely to have a delay in diagnosis &gt;60 days (odds ratio [OR], 1.08; 95% confidence interval [CI], 0.98–1.19) after adjustment for type of initial sign or symptom. Young women were only modestly more likely to present with higher stage disease after a similar adjustment (OR, 1.18; 95% CI, 1.07–1.31). Women presenting with symptomatic disease, more common in younger women, were more likely to have a delay in diagnosis (OR, 3.31; 95% CI, 3.08–3.56) and higher stage (OR, 4.31; 95% CI 4.05–4.58).Conclusion.Young age is not an independent predictor of delay in diagnosis of breast cancer and only modestly is associated with higher stage disease. Presenting with symptoms of breast cancer predicts delay and higher stage at diagnosis.
Fibroblast Growth Factor 23 and Inflammation in CKD
Authors: Munoz Mendoza Jair , Isakova Tamara , Ricardo Ana C. , Xie Huiliang , Navaneethan Sankar D. , Anderson Amanda H. , Bazzano Lydia A. , Xie Dawei , Kretzler Matthias , Nessel Lisa , Hamm L. Lee , Negrea Lavinia , Leonard Mary B. , Raj Dominic , Wolf Myles 
Published: May 2012

Summary

Background and objectives
Levels of fibroblast growth factor 23 (FGF23) and inflammatory markers are commonly elevated in CKD, and each is associated with adverse clinical outcomes. This study tested the hypothesis that FGF23 is independently associated with inflammation in CKD.

Design, setting, participants, & measurements
The association between levels of FGF23 and the inflammatory markers IL-6, C-reactive protein (CRP), TNF-α, and fibrinogen was assessed in a cross-sectional analysis of 3879 participants enrolled in the Chronic Renal Insufficiency Cohort (CRIC) study between June 2003 and September 2008.

Results
FGF23 correlated directly with IL-6 (r=0.4), CRP (r=0.2), TNF-α (r=0.4), and fibrinogen (r=0.3; P<0.001 for each). In univariate and multivariable-adjusted linear regression analyses, natural log (ln) transformed FGF23 was significantly associated with lnIL-6, lnCRP, lnTNF-α, and fibrinogen (P<0.001 for each). Each unit higher lnFGF23 was associated with severe inflammation, defined as levels of all inflammatory markers in the highest 25th percentile, in univariate (odds ratio [OR], 2.4 [95% confidence interval (CI), 2.0–2.9]) and multivariable-adjusted (OR, 2.0 [95% CI, 1.6–2.5]) logistic regression analyses. Ascending FGF23 quartiles were independently associated with severe inflammation (OR, 5.6 for the highest versus lowest FGF23 quartile [95% CI, 2.3–13.9]; P for trend < 0.001).

Conclusions
Higher FGF23 levels are independently associated with higher levels of inflammatory markers in patients with CKD and with significantly greater odds of severe inflammation. Future studies should evaluate whether inflammation modifies the association between FGF23 and adverse outcomes in CKD.
Mandatory Disclosure of the Engagement Partner's Identity: Potential Benefits and Unintended Consequences
Authors: King Ronald R. , Davis Shawn M. , Mintchik Natalia 
Published: May 2012

SYNOPSIS
This paper contributes to the deliberations on the potential consequences of requiring disclosure of the engagement partner's identity in the audit report. The PCAOB has recently suggested that this requirement will lead to enhanced audit quality due to increased engagement partner accountability and improved transparency of the audit process. The goal of our commentary is to examine this issue by considering factors that potentially affect audit quality in appearance and audit quality in fact, and applying insights from three distinct academic frameworks: source credibility, accountability, and the theory of affordances.
While prior evidence from source credibility research implies that a mandatory signature will likely increase audit quality in appearance, its impact on audit quality in fact remains unclear. Academic literature suggests that increased accountability will increase audit effort but is silent on the associated increase in audit effectiveness. As a result, mandatory disclosure is likely to increase the risk of over-auditing because audit services have the essential characteristics of a credence good. As for an increase in audit quality in appearance, the question remains whether the current perception of audit quality is too low or too high. The increase in public perceptions of audit quality without an associated increase in actual quality is a desirable accomplishment only when public perception of quality is below actual audit quality. Otherwise, the measure increases the gap between delivered audit quality and public perceptions of it. We suggest specific research opportunities in this area.
Use of histologic margin evaluation to predict recurrence of cutaneous malignant tumors in dogs and cats after surgical excision
Authors: Scarpa Filippo , Sabattini Silvia , Marconato Laura , Capitani Ombretta , Morini Maria , Bettini Giuliano 
Published: May 2012

Abstract
Objective—To assess the usefulness of histologic evaluation of surgical margins to predict local recurrence of cutaneous malignant tumors in dogs and cats treated by means of surgical excision.
Design—Prospective case series.
Animals—40 dogs and 20 cats.
Procedures—60 surgically excised tumors (20 soft tissue sarcomas [STSs], 20 mast cell tumors [MCTs], and 20 carcinomas) were examined histologically. Margins were classified as clean, close, or infiltrated; histologic grade was assessed in STSs and MCTs. Recurrence rates and recurrence-free intervals (RFIs) during a 24-month follow-up period were recorded, and method accuracy was calculated.
Results—Surgical margins were clean in 29 of 60 (48%) tumors, close in 11 (18%), and infiltrated in 20 (33%). Tumors recurred in 27 of 60 (45%) animals, with a mean ± SD RFI of 229 ± 173 days. Recurrence rates for animals that had tumors with infiltrated (16/20) or close (8/11) margins were significantly higher than recurrence rate for animals that had tumors with clean margins (3/29). Margin classification was a significant predictor of RFI. Accuracy of the method to predict recurrence was 94% for carcinomas, 87% for STSs, and 76% for MCTs.
Conclusions and Clinical Relevance—Histologic assessment of margin status was useful for predicting local recurrence of cutaneous malignant tumors in dogs and cats treated by means of excision alone. Method accuracy varied among tumor types and grades. Recurrence times suggested postsurgical follow-up should continue for ≥ 2 years. Results were similar for animals with infiltrated and close tumor margins, and careful postsurgical management is recommended for both.
Mitral valve repair under cardiopulmonary bypass in small-breed dogs: 48 cases (2006–2009)
Authors: Uechi Masami , Mizukoshi Takahiro , Mizuno Takeshi , Mizuno Masashi , Harada Kayoko , Ebisawa Takashi , Takeuchi Junichirou , Sawada Tamotsu , Uchida Shuhei , Shinoda Asako , Kasuya Arane , Endo Masaaki , Nishida Miki , Kono Shota , Fujiwara Megumi , Nakamura Takashi 
Published: May 2012

Abstract
Objective—To determine whether mitral valve repair (MVR) under cardiopulmonary bypass would be an effective treatment for mitral regurgitation in small-breed dogs.
Design—Retrospective case series.
Animals—48 small-breed dogs (body weight, 1.88 to 4.65 kg [4.11 to 10.25 lb]; age, 5 to 15 years) with mitral regurgitation that underwent surgery between August 2006 and August 2009.
Procedures—Cardiopulmonary bypass was performed with a cardiopulmonary bypass circuit. After induction of cardiac arrest, a mitral annuloplasty was performed, and the chordae tendineae were replaced with expanded polytetrafluoroethylene chordal prostheses. After closure of the left atrium and declamping to restart the heart, the thorax was closed.
Results—Preoperatively, cardiac murmur was grade 3 of 6 to 6 of 6, thoracic radiography showed cardiac enlargement (median vertebral heart size, 12.0 vertebrae; range, 9.5 to 14.5 vertebrae), and echocardiography showed severe mitral regurgitation and left atrial enlargement (median left atrium-to-aortic root ratio, 2.6; range, 1.7 to 4.0). 45 of 48 dogs survived to discharge. Three months after surgery, cardiac murmur grade was reduced to 0/6 to 3/6, and the heart shadow was reduced (median vertebral heart size, 11.1 vertebrae, range, 9.2 to 13.0 vertebrae) on thoracic radiographs. Echocardiography confirmed a marked reduction in mitral regurgitation and left atrium-to-aortic root ratio (median, 1.7; range, 1.0 to 3.0).
Conclusions and Clinical Relevance—We successfully performed MVR under cardiopulmonary bypass in small-breed dogs, suggesting this may be an effective surgical treatment for dogs with mitral regurgitation. Mitral valve repair with cardiopulmonary bypass can be beneficial for the treatment of mitral regurgitation in small-breed dogs.