bluuebunny/crossref_metadata_2025_split huggingface dataset:
Functional Status Determines Postoperative Outcomes in Elderly Patients Undergoing Hepatic Resections
Authors: DE LA FUENTE SEBASTIAN G. , BENNETT KYLA M. , SCARBOROUGH JOHN E. 
Published: April 2013

AbstractBackgroundWith the aging population and increasing incidence of hepatic malignancies in elderly patients, establishing the safety of hepatic resections is crucial. The present study investigates early postoperative morbidity and mortality in elderly patients undergoing hepatic resection using a nationally validated database.MethodsThe National Surgical Quality Improvement Program Participant User Files (NSQIP‐PUF) for 2005–2009 were used for the retrospective analysis of all patients undergoing hepatic resection. The primary outcome measures were 30‐day postoperative mortality, overall complication rate, and serious complication rate. The primary predictor variable was patient age, which was treated as a dichotomous variable (age ≤70 years, age ≥70 years).ResultsFive thousand seven hundred six patients were included in the final analysis, 1,280 of which were ≥70 years of age. Thirty‐day postoperative mortality (≤70 years 1.9% vs. ≥70 years 4.5%, P < 0.0001), serious complications (≤70 years 15.2% vs. ≥ 70 years 18.4%, P < 0.006) and overall complications (≤70 years 23.1% vs. ≥70 years 26.6%, P < 0.01) were more common in the elderly group. Elderly patients had significantly more wound infections, pneumonia, prolonged ventilator support, unplanned re‐intubations, renal failure, strokes, myocardial infarction, cardiac arrests, and septic shock. The median length of hospitalization was also significantly longer in the elderly.ConclusionsThis study shows significantly higher complication rates and mortality following hepatic resections in elderly patients. These findings should be taken into account when considering hepatectomy in this population. J. Surg. Oncol. 2013;107:865–870. © 2013 Wiley Periodicals, Inc.
Limiting behavior of the stochastic sequential assignment problem
Authors: Baharian Golshid , Jacobson Sheldon H. 
Published: April 2013

AbstractThe stochastic sequential assignment problem (SSAP) considers how to allocate available distinct workers to sequentially arriving tasks with stochastic parameters such that the expected total reward obtained from the sequential assignments is maximized. Implementing the optimal assignment policy for the SSAP involves calculating a new set of breakpoints upon the arrival of each task (i.e., for every time period), which is impractical for large‐scale problems. This article studies two problems that are concerned with obtaining stationary policies, which achieve the optimal expected reward per task as the number of tasks approaches infinity. The first problem considers independent and identically distributed (IID) tasks with a known distribution function, whereas in the second problem tasks are derived from r different unobservable distributions governed by an ergodic Markov chain. The convergence rate of the expected reward per task to the optimal value is also obtained for both problems. © 2013 Wiley Periodicals, Inc. Naval Research Logistics, 2013
Biallelic DICER1 mutations occur in Wilms tumours
Authors: Wu MK , Sabbaghian N , Xu B , Addidou‐Kalucki S , Bernard C , Zou D , Reeve AE , Eccles MR , Cole C , Choong CS , Charles A , Tan TY , Iglesias DM , Goodyer PR , Foulkes WD 
Published: April 2013

AbstractDICER1 is an endoribonuclease central to the generation of microRNAs (miRNAs) and short interfering RNAs (siRNAs). Germline mutations in DICER1 have been associated with a pleiotropic tumour predisposition syndrome and Wilms tumour (WT) is a rare manifestation of this syndrome. Three WTs, each in a child with a deleterious germline DICER1 mutation, were screened for somatic DICER1 mutations and were found to bear specific mutations in either the RNase IIIa (n = 1) or the RNase IIIb domain (n = 2). In the two latter cases, we demonstrate that the germline and somatic DICER1 mutations were in trans, suggesting that the two‐hit hypothesis of tumour formation applies for these examples of WT. Among 191 apparently sporadic WTs, we identified five different missense or deletion somatic DICER1 mutations (2.6%) in four individual WTs; one tumour had two very likely deleterious somatic mutations in trans in the RNase IIIb domain (c.5438A>G and c.5452G>A). In vitro studies of two somatic single‐base substitutions (c.5429A>G and c.5438A>G) demonstrated exon 25 skipping from the transcript, a phenomenon not previously reported in DICER1. Further we show that DICER1 transcripts lacking exon 25 can be translated in vitro. This study has demonstrated that a subset of WTs exhibits two ‘hits’ in DICER1, suggesting that these mutations could be key events in the pathogenesis of these tumours. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Conformational selection and induced changes along the catalytic cycle of Escherichia coli dihydrofolate reductase
Authors: Weikl Thomas R. , Boehr David D. 
Published: April 2013

AbstractProtein function often involves changes between different conformations. Central questions are how these conformational changes are coupled to the binding or catalytic processes during which they occur, and how they affect the catalytic rates of enzymes. An important model system is the enzyme dihydrofolate reductase (DHFR) from Escherichia coli, which exhibits characteristic conformational changes of the active‐site loop during the catalytic step and during unbinding of the product. In this article, we present a general kinetic framework that can be used (1) to identify the ordering of events in the coupling of conformational changes, binding, and catalysis and (2) to determine the rates of the substeps of coupled processes from a combined analysis of nuclear magnetic resonance R2 relaxation dispersion experiments and traditional enzyme kinetics measurements. We apply this framework to E. coli DHFR and find that the conformational change during product unbinding follows a conformational‐selection mechanism, that is, the conformational change occurs predominantly prior to unbinding. The conformational change during the catalytic step, in contrast, is an induced change, that is, the change occurs after the chemical reaction. We propose that the reason for these conformational changes, which are absent in human and other vertebrate DHFRs, is robustness of the catalytic rate against large pH variations and changes to substrate/product concentrations in E. coli. Proteins 2012;. © 2012 Wiley Periodicals, Inc.
Relation between flexibility and positively selected HIV‐1 protease mutants against inhibitors
Authors: Braz Antônio S. K. , Tufanetto Patrícia , Perahia David , Scott Luis P. B. 
Published: April 2013

AbstractThe antiretroviral chemotherapy helps to reduce the mortality of HIVs infected patients. However, RNA dependant virus replication has a high mutation rate. Human immunodeficiency virus Type 1 protease plays an essential role in viral replication cycle. This protein is an important target for therapy with viral protein inhibitors. There are few works using normal mode analysis to investigate this problem from the structural changes viewpoint. The investigation of protein flexibility may be important for the study of processes associated with conformational changes and state transitions. The normal mode analysis allowed us to investigate structural changes in the protease (such as flexibility) in a straightforward way and try to associate these changes with the increase of fitness for each positively selected HIV‐1 mutant protease of patients treated with several protease inhibitors (saquinavir, indinavir, ritonavir, nelfinavir, lopinavir, fosamprenavir, atazanavir, darunavir, and tripanavir) in combination or separately. These positively selected mutations introduce significant flexibility in important regions such as the active site cavity and flaps. These mutations were also able to cause changes in accessible solvent area. This study showed that the majority of HIV‐1 protease mutants can be grouped into two main classes of protein flexibility behavior. We presented a new approach to study structural changes caused by positively selected mutations in a pathogen protein, for instance the HIV‐1 protease and their relationship with their resistance mechanism against known inhibitors. The method can be applied to any pharmaceutically relevant pathogen proteins and could be very useful to understand the effects of positively selected mutations in the context of structural changes. Proteins 2012; © 2012 Wiley Periodicals, Inc.
A Mathematical Model of the Solid Flow Behavior in a Real Dimension Blast Furnace: Effects of the Solid Volume Fraction on the Velocity Profile
Authors: Safavi Nick Reza , Tilliander Anders , Jonsson Lage T. I. , Jönsson Pär G. 
Published: April 2013

AbstractA mathematical model based on the continuum mechanic concept has been developed to describe the profile of solid particles in a blast furnace with respect to the in‐furnace conditions and characteristics, e.g., the shape and size of the deadman. The Navier‐Stokes differential equation for multi‐phase multi‐dimensional space has been used to describe the behavior of existing phases. The equation has been modified to make it possible to describe the dual nature of the solid phase in the system by applying the concept of the solid surface stress to characterize the inter‐granular surface interactions between particles. Since different phases co‐exist in a blast furnace, the volume fraction plays an important role in a blast furnace. Therefore, the influence of three different packing densities (0.68, 0.71, and 0.74, respectively) on the profile of the flow in the upper part of a furnace down to the tuyeres level has been studied. It is shown that an increase in the volume fraction of the solid phase lead to a decrease in magnitude of the velocity. The decrease in the magnitude of the velocity due to an increase in the solid volume fraction will increase the resident time of the particles inside a blast furnace. In addition, it is shown that the solid phase velocity magnitude decreases from the throat to the belly of the furnace for the studied conditions. However, after belly the velocity magnitude increases.
Clinical Implication of Cancer Adhesion in Papillary Thyroid Carcinoma: Clinicopathologic Characteristics and Prognosis Analyzed with Degree of Extrathyroidal Extension
Authors: Jung Seung Pil , Kim Minkuk , Choe Jun‐Ho , Kim Jee Soo , Nam Seok Jin , Kim Jung‐Han 
Published: April 2013

AbstractBackgroundMacroscopic extrathyroidal extension (ETE) is a poor prognostic factor in papillary thyroid carcinoma (PTC). However, intraoperative inspection for ETE is often inaccurate and could lead the surgeon to misconstrue simple adhesion as gross ETE. Such confusion could result in more aggressive treatment than necessary. In the present study we investigated the frequency and clinical implication of simple adhesions.MethodsWe identified 858 patients who underwent total thyroidectomy for papillary thyroid carcinoma (PTC). Clinicopathologic features, prognosis, and stimulated serum thyroglobulin (Tg) levels were compared between four groups divided according to degree of ETE: no ETE (n = 335), simple adhesion (n = 16), microscopic ETE (n = 378), and macroscopic ETE (n = 129).ResultsIn the total of 145 cases, which were recognized as gross ETE under intraoperative inspection, 16 cases (11.0 %) were diagnosed as cancer confined to the thyroid without ETE by definite histology. The simple adhesion group showed no statistical differences in postoperative stimulated Tg levels from the no ETE and microscopic ETE groups (p > 0.05). In contrast, the distribution of postoperative Tg levels in the macroscopic ETE group was significantly higher than in the other groups (p < 0.001). During the 54‐month median follow‐up period, the macroscopic ETE and microscopic ETE groups showed poorer relapse‐free survival than the no ETE and simple adhesion groups (p < 0.05).ConclusionsThe findings of the present study indicate that the discrepancy between intraoperative inspection and definite histology is not negligible when dense adhesions are present. When no tumor is found, the patient with inflammatory or fibrotic adhesions has a favorable prognosis.
Mammary gene expression and activity of antioxidant enzymes and oxidative indicators in the blood, milk, mammary tissue and ruminal fluid of dairy cows fed flax meal
Authors: Schogor Ana Luiza Bachmann , Palin Marie-France , dos Santos Geraldo Tadeu , Benchaar Chaouki , Lacasse Pierre , Petit Hélène V. 
Published: April 2013

The effects of flax meal (FM) on the activity of antioxidant enzymes (superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT)) in the blood, mammary tissue and ruminal fluid, and oxidative stress indicators (thiobarbituric acid-reactive substances (TBARS) and 1,1-diphenyl-2-picrylhydrazyl-scavenging activity) in the milk, plasma and ruminal fluid of dairy cows were determined. The mRNA abundance of the antioxidant enzymes and oxidative stress-related genes was assessed in mammary tissue. A total of eight Holstein cows were used in a double 4 × 4 Latin square design. There were four treatments in the diet: control with no FM (CON) or 5 % FM (5FM), 10 % FM (10FM) and 15 % FM (15FM). There was an interaction between treatment and time for plasma GPx and CAT activities. Cows supplemented with FM had a linear reduction in TBARS at 2 h after feeding, and there was no treatment effect at 0, 4 and 6 h after feeding. TBARS production decreased in the milk of cows fed the 5FM and 10FM diets. There was a linear increase in nuclear factor (erythroid-derived 2)-like 2 (NFE2L2) mRNA abundance in mammary tissue with FM supplementation. A linear trend for increased mRNA abundance of the CAT gene was observed with higher concentrations of FM. The mRNA abundance of CAT, GPx1, GPx3, SOD1, SOD2, SOD3 and nuclear factor of κ light polypeptide gene enhancer in B-cells (NFKB) genes was not affected by the treatment. These findings suggest that FM supplementation can improve the oxidative status of Holstein cows as suggested by decreased TBARS production in ruminal fluid 2 h post-feeding and increased NFE2L2/nuclear factor-E2-related factor 2 (Nrf2) mRNA abundance in mammary tissue.
Why Do Closed-End Bond Funds Exist? An Additional Explanation for the Growth in Domestic Closed-End Bond Funds
Authors: Elton Edwin J. , Gruber Martin J. , Blake Christopher R. , Shachar Or 
Published: April 2013

AbstractThis paper provides a new explanation for why closed-end bond funds coexist along with otherwise identical open-end bond funds. Closed-end bond funds offer investors the opportunity to leverage their fixed income investment at very low borrowing rates and are attractive to investors for this reason. We find that differences in leverage are reflected in the discount on closed-end bond funds in a manner consistent with the advantage of leverage.
Soil and water management.
Authors: Funt R. C. , Ross D. S. 
Published: April 2013

Abstract

The primary goals of soil management are to maintain fertility, reduce erosion of the topsoil and maintain good soil structure with minimum tillage. The primary goal of water management is to maintain adequate soil moisture for producing an optimal canopy for maximum fruit production. The soil management, fertility and fertilization, irrigation and water management, (water supply, water quality, water requirements, moisture monitoring, and irrigation business plan), and weed management on raspberry production are discussed.
The roles of aryl hydrocarbon receptor in immune responses
Authors: Nguyen Nam Trung , Hanieh Hamza , Nakahama Taisuke , Kishimoto Tadamitsu 
Published: April 2013

AbstractA number of recent studies have examined the functions of aryl hydrocarbon receptor (Ahr) in the immune system. Also known as dioxin receptor, Ahr is a ligand-activated transcription factor that serves as a receptor for various environmental toxins. The functions of Ahr in T cells depend on the specific ligand bound to the receptor. For instance, binding of 2,3,7,8-tetrachlorodibenzo-p-dioxin to Ahr suppresses experimental autoimmune encephalomyelitis (EAE) by promoting the development of Foxp3+ Treg cells, whereas 6-formylindolo[3,2-b]carbazole enhances EAE by inducing the differentiation of IL-17-producing T cells. Furthermore, specifically deleting Ahr in T cells inhibits collagen-induced arthritis in mice. In macrophages and dendritic cells (DCs), Ahr is anti-inflammatory. In response to LPS, Ahr-deficient macrophages show increased production of pro-inflammatory cytokines, such as IL-6 and TNF-α, and Ahr-deficient DCs produce less of the anti-inflammatory cytokine IL-10. In this review, we discuss the roles of Ahr in macrophages and T cells. Moreover, studies examining Ahr activation in other cell types have revealed additional contributions to B cell and osteoblast/osteoclast differentiation. We also briefly summarize the current understanding of regulatory mechanisms underlying Ahr activation in various cells and discuss the potential clinical implications of cell-specific targeting of Ahr in pathologic conditions of the immune system.
Field independence: Reviewing the evidence
Authors: Evans Carol , Richardson John T. E. , Waring Michael 
Published: April 2013

BackgroundThe construct of field independence (FI) remains one of the most widely cited notions in research on cognitive style and on learning and instruction more generally. However, a great deal of confusion continues to exist around the definition of FI, its measurement, and the interpretation of research results, all of which have served to limit our understanding of and practice in education.AimsThis study reviews research evidence on FI and highlights key issues to frame a more informed agenda for future research.ArgumentsCaution needs to be exercised over the interpretation of the evidence around FI and field dependence (FD). In tests measuring FI only, it is inappropriate to use the term FD. FI is clearly correlated with measures of spatial ability; however, whether FI is just a measure of perceptual and more specifically spatial ability is a matter of debate. Furthermore, whether FI is just a cognitive ability or a cognitive style is not the central issue, as both can be developed. FI has a significant relationship with aspects of working memory and with other variables. It is especially important in the management and interpretation of complex cognitive tasks.ConclusionsField independence has an important role to play in the navigation of the complex and information‐rich learning environments of the 21st century. It is therefore important to move beyond the present narrow focus on FI as a style or trait by acknowledging, embracing, and exploring the complexity of the interaction between individual and contextual variables.
An analysis of patients with T2 renal cell carcinoma (RCC) according to tumour size: a population‐based analysis
Authors: Bianchi Marco , Becker Andreas , Trinh Quoc‐Dien , Abdollah Firas , Tian Zhe , Shariat Shahrokh F. , Montorsi Francesco , Perrotte Paul , Graefen Markus , Karakiewicz Pierre I. , Sun Maxine 
Published: April 2013

Objective
To examine the discriminant properties of the most contemporary version of the Tumour‐Node‐Metastasis (TNM) staging for renal cell carcinoma (RCC) sub‐classification of T2 lesions according to a threshold size of 10 cm. Other thresholds were also assessed.
Patients and Methods
Between 1988 and 2006, within the Surveillance, Epidemiology, and End Results database, patients with T2 N0–2 M0–1 RCC treated with a nephrectomy were abstracted.
Tumour size was evaluated according to several thresholds: ≥8, ≥9, ≥10, ≥11, and ≥12 cm. Kaplan–Meier and life tables for cancer‐specific mortality (CSM) were computed.
Several Cox regression modes were fitted for prediction of CSM, using different thresholds.
The predictive accuracy of various thresholds was compared using the area under the curve and methods of calibration.
Results
In all, 4963 patients were identified. Kaplan–Meier analyses showed statistically significant CSM‐free survival differences between all examined thresholds.
In multivariable Cox‐regression models, all tested tumour size thresholds emerged as independent predictors of CSM.
Of all thresholds, the values of 9 (0.55) and 11 cm (0.55) achieved the highest discrimination in univariable analysis, followed by 10 (0.539), 12 (0.539), and 8 cm (0.531).
When the thresholds were combined with all other variables, the 11 cm (0.688) achieved the highest discrimination.
Conclusion
The discriminant properties of all examined thresholds showed very similar discriminant properties, which brings into questioning whether a dichotomization of pT2 tumours is really necessary.
The role of chronic prostatic inflammation in the pathogenesis and progression of benign prostatic hyperplasia (BPH)
Authors: Gandaglia Giorgio , Briganti Alberto , Gontero Paolo , Mondaini Nicola , Novara Giacomo , Salonia Andrea , Sciarra Alessandro , Montorsi Francesco 
Published: April 2013

Several different stimuli may induce chronic prostatic inflammation, which in turn would lead to tissue damage and continuous wound healing, thus contributing to prostatic enlargement.
Patients with chronic inflammation and benign prostatic hyperplasia (BPH) have been shown to have larger prostate volumes, more severe lower urinary tract symptoms (LUTS) and a higher probability of acute urinary retention than their counterparts without inflammation.
Chronic inflammation could be a predictor of poor response to BPH medical treatment. Thus, the ability to identify patients with chronic inflammation would be crucial to prevent BPH progression and develop target therapies.
Although the histological examination of prostatic tissue remains the only available method to diagnose chronic inflammation, different parameters, such as prostatic calcifications, prostate volume, LUTS severity, storage and prostatitis‐like symptoms, poor response to medical therapies and urinary biomarkers, have been shown to be correlated with chronic inflammation.
The identification of patients with BPH and chronic inflammation might be crucial in order to develop target therapies to prevent BPH progression. In this context, clinical, imaging and laboratory parameters might be used alone or in combination to identify patients that harbour chronic prostatic inflammation.
Percutaneous cryoablation of renal tumours: outcomes from 171 tumours in 147 patients
Authors: Breen David J. , Bryant Timothy J. , Abbas Ausami , Shepherd Beth , McGill Neil , Anderson Jane A. , Lockyer Richard C. , Hayes Matthew C. , George Steve L. 
Published: April 2013

Objective
To evaluate the technical and oncological efficacy of an image‐guided cryoablation programme for renal tumours.
Patients and Methods
A prospective analysis of technical and radiological outcomes was undertaken after treatment of 171 consecutive tumours in 147 patients.
Oncological efficacy in a subset of 125 tumours in 104 patients with >6 months' radiological follow‐up and a further subset of 62 patients with solitary, biopsy‐proven renal carcinoma was also analysed.
Factors influencing technical success, as determined by imaging follow‐up, and complication rates were statistically analysed using a statistics software package and logistic regression analyses.
Results
No variables were found to predict subtotal treatment, although gender (P = 0.08), tumour size of >4 cm (P = 0.09) and central location of tumour (P = 0.07) approached significance.
Upper pole location was the single variable that was found to predict complications (P = 0.006).
Among the 104 patients (125 tumours), radiologically assessed at ≥6 months and with a mean radiological follow‐up of 20.1 months, we found a single case of unexpected late local recurrence.
Conclusion
Percutaneous image‐guided cryoablation, at a mean of 20.1 months' follow‐up, appears to provide a safe and effective treatment option with a low complication rate.
Anteriorly sited tumours should not be considered a contraindication for percutaneous image‐guided cryoablation.