bluuebunny/crossref_metadata_2025 huggingface dataset:
Extractive recovery of aqueous diamines for bio‐based plastics production
Authors: Krzyżaniak Agnieszka , Schuur Boelo , de Haan André B.
Published: February 2013

Background

This paper reports an extractant screening study for the recovery of putrescine (butylene‐1,4‐diamine,BDA) and cadaverine (pentylene‐1,5‐diamine,PDA) from aqueous solutions (e.g. fermentation broths) by liquid–liquid extraction. Several extractants were studied, including 4‐nonylphenol, 3,4‐bis((2‐ethylhexyl)oxy)phenol, di‐2‐ethylhexyl phosphoric acid (D2EHPA), Versatic acid 1019, di‐nonyl‐naphthalene‐sulfonic acid (DNNSA), and 4‐octylbenzaldehyde. 1‐Octanol, 2‐octyl‐1‐dodecanol and heptane were used as diluents, and temperatures of 25 °C and 65 °C.

Results

The most promising solvent is 4‐nonylphenol, hardly leaching into the aqueous raffinate (19 ppm), and showingBDAdistribution coefficients very strongly dependent on the extractant concentration, ranging from very low distribution ( D ∼ 1 at <20 wt% 4‐nonylphenol in 1‐octanol at 25 °C) to high distribution (D > 100) for pure 4‐nonylphenol at 25 °C. The strong dependency of the distribution on extract phase composition was applied to efficiently back‐extract up to 90%BDAin a single step. To achieve this, the pure 4‐nonylphenol used in extraction was diluted to a 20 wt% dilution in 1‐octanol. The use of 4‐nonylphenol as extractant was also examined forPDA, and higher distributions were observed than forBDA, which can be attributed to the longer hydrocarbon chain ofPDA.

Conclusions

Recovery of diamines from aqueous medium can be accomplished in an effective way using 4‐nonylphenol as extractant. These results may be used to develop a bio‐based butylene‐1,4‐diamine production route. © 2013 Society of Chemical Industry
Calibration and validation of a model describing complete autotrophic nitrogen removal in a granular SBR system
Authors: Vangsgaard Anna Katrine , Mutlu A. Gizem , Gernaey Krist V. , Smets Barth F. , Sin Gürkan
Published: February 2013

BACKGROUND

A validated model describing the nitritation‐anammox process in a granular sequencing batch reactor (SBR) system is an important tool for: (a) design of future experiments; and (b) prediction of process performance during optimization, while applying process control, or during system scale‐up.

RESULTS

A model was calibrated using a step‐wise procedure customized for the specific needs of the system. The important steps in the procedure were initialization, steady‐state and dynamic calibration, and validation. A fast and effective initialization approach was developed to approximate pseudo steady‐state in the biofilm system. For oxygen mass transfer coefficient (kLa) estimation, long‐term data, removal efficiencies, and the stoichiometry of the reactions were used. For the dynamic calibration a pragmatic model fitting approach was used – in this case an iterative Monte Carlo based screening of the parameter space – to find the best fit of the model to dynamic data. Finally, the calibrated model was validated with an independent data set.

CONCLUSION

The calibration procedure presented is the first customized procedure for this type of system and is expected to contribute to achieving a fast and effective model calibration, an important enabling tool for various biochemical engineering design, control and operation problems. © 2013 Society of Chemical Industry
Exocytosis of neurosecretory granules from the crustacean sinus gland in freeze‐fracture
Authors: Shivers Richard R.
Published: February 2013

Exocytosis is clearly shown in freeze‐fracture preparations to be the mechanism for neurosecretion granule release from axon endings in the crayfish sinus gland. The cytoplasmic leaflet (A‐face) of axon ending membrane is characterized by randomly situated depressions representing invaginations of the axolemma, which are in contact with limiting membranes of neurohormone granules in the subjacent cytoplasm. The extracellular leaflet (B‐face) of the axolemma at release sites exhibits complementary volcano‐shaped protrusions which are cross‐fractures through necks of channels formed by invaginating plasma membrane in contact with underlying neurosecretion granules. Structural variation in B‐face protrusions is consistent with a spectrum of exocytotic profiles in various stages of formation, and with granules at different stages of passage out of the endings. Evidence in this study suggests that formation of exocytotic structures may begin by alteration of axon membrane structure at the neurosecretory ending‐hemolymph interface prior to contact of the neurohormone granules with the axolemma. Limiting membranes of neurosecretory granules exhibit protrusions which appear to interconnect granules adjacent to release sites and to attach granules to the axolemma. Freeze‐fracture is clearly shown to be an invaluable tool for monitoring the degree of exocytosis exhibited by sinus glands under normal conditions and under experimental acceleration of hormone release. This technique is capable therefore, of detecting slight increases in numbers of exocytotic profiles much more quickly and accurately than the examination of random thin sections.
Frequent detection of cytomegalovirus (CMV) DNA in the lower respiratory tract in CMV‐seropositive pediatric patients with underlying chronic bronchopulmonary diseases lacking canonical immunosuppression
Authors: Escribano Amparo , Chilet Marifina , Clari María Ángeles , Lucas Raquel , Costa Elisa , Bravo Dayana , Muñoz‐Cobo Beatriz , Borrás Rafael , Navarro David
Published: February 2013

Cytomegalovirus (CMV) may be a relevant cause of morbidity in patients displaying various inflammatory diseases. In this study, it was investigated whether CMV DNA is detected in the lower respiratory tract and the systemic compartment in pediatric patients with chronic or recurrent bronchopulmonary diseases. A total of 42 lower respiratory tract specimens and 11 paired plasma samples from 42 patients were analyzed for the presence of CMV DNA by real‐time PCR. The respiratory specimens were also screened for the presence of respiratory viruses and human herpesvirus 6 (HHV‐6) and 7 (HHV‐7) by PCR methods. Quantitative bacterial and fungal cultures were performed. IL‐6 levels in the respiratory specimens were quantified using ELISA. CMV DNA was detected either in the lower respiratory airways, in plasma, or both in 54.5% of CMV‐seropositive patients. The levels of IL‐6 were significantly higher in these patients than in those with no detectable levels of CMV DNA. HHV‐6 and HHV‐7 DNA were detected in three and one patients, respectively. Respiratory viruses were detected in 13 of the 42 patients. Significant growth of one or more bacterial species was observed in 17 patients. No significant association was found between the presence of CMV DNA and the detection of other microorganisms. The data indicated that the presence of CMV DNA in the lower respiratory tract is a frequent finding in children with chronic or recurrent bronchopulmonary diseases. Further, prospective observational studies are needed to assess the impact of this phenomenon, if any, on the clinical course of these patients. J. Med. Virol. 85:888–892, 2013. © 2013 Wiley Periodicals, Inc.
High frequency of complex mutational patterns in lamivudine resistant hepatitis B virus isolates
Authors: Neumann‐Fraune Maria , Beggel Bastian , Pfister Herbert , Kaiser Rolf , Verheyen Jens
Published: February 2013

The evolution of hepatitis‐B virus (HBV) drug resistance is characterized by the emergence of resistance conferring mutations and compensatory mutations. Therefore HBV drug‐resistant isolates often harbor multiple mutations in the reverse transcriptase (RT) and corresponding mutations in the hepatitis B surface antigen (HBsAg). In this study mutational patterns of 60 HBV isolates harboring drug resistance mutations rtM204V or rtM204I were retrospectively analyzed. Both mutations, especially mutation rtM204V, were most often accompanied by compensatory mutations rtV173L and rtL180M but also by mutations conferring entecavir (n = 5) or adefovir resistance (n = 4). In addition, 22 (36.7%) drug resistant HBV isolates carried mutations related to immune escape in the HBsAg. In seven cases premature stop codons in HBsAg were detected resulting in the expression of truncated HBsAg. Clonal analysis of these seven quasispecies even disclosed the presence of HBV isolates carrying further stop codons and in one case the occurrence of resistance mutation rtA181T without the stop codon mutation sW172*. Interestingly, only one HBV clone carried the resistance mutations rtM204V and rtA181T. HBV drug resistant isolates frequently harbored HBsAg mutations associated with immune escape or disease progression pointing to a complex interaction of both proteins. HBV genotypic resistance tests based on population sequencing methods seemed to be inappropriate for determining the clinical relevance of stop codons in the HBsAg. J. Med. Virol. 85:775–779, 2013. © 2013 Wiley Periodicals, Inc.
HTR2A−1438A/G polymorphism influences the risk of schizophrenia but not bipolar disorder or major depressive disorder: A meta‐analysis
Authors: Gu Lian , Long Jianxiong , Yan Yan , Chen Qiang , Pan Runde , Xie Xinfeng , Mao Xixiang , Hu Xueying , Wei Bo , Su Li
Published: February 2013

The incidence of psychiatric disorders has been shown to have a strong genetic component, and we conducted this study to investigate whether the −1438A/G polymorphism of the HTR2A gene was associated with susceptibility to schizophrenia (SZ), bipolar disorder (BD), and major depressive disorder (MDD). Pooled odd ratios (ORs) and 95% confidence intervals (95% CIs) were calculated using data obtained from a total 27 studies that investigated an association between the HTR2A −1438A/G polymorphism and SZ (15), BD (7), and MDD (4). We failed to observe an association between the HTR2A −1438A/G polymorphism and BD and MDD, and we found contrary results with regard to SZ. Our results showed that the −1438A/G polymorphism was a risk factor for SZ, especially in Caucasians (allele model: OR, 1.12; 95% CI, 1.05–1.20; I2 = 17.3%; dominant model: OR, 1.14; 95% CI, 1.03–1.27; I2 = 15.3%; recessive model: OR, 1.20; 95% CI, 1.06–1.37; I2 = 0.0%; codominant model 1: OR, 1.16; 95% CI, 1.01–1.32; I2 = 0.0%). We found that the association of the HTR2A −1438A/G polymorphism with SZ depends on the ethnic origin of the study population, and this genetic variant does not modify the susceptibility to BD or MDD. © 2013 Wiley Periodicals, Inc.
3,6′‐dithiothalidomide improves experimental stroke outcome by suppressing neuroinflammation
Authors: Yoon Jeong Seon , Lee Jong‐Hwan , Tweedie David , Mughal Mohamed R. , Chigurupati Srinivasulu , Greig Nigel H. , Mattson Mark P.
Published: February 2013

Tumor necrosis factor‐α (TNF) plays a prominent role in the brain damage and functional deficits that result from ischemic stroke. It was recently reported that the thalidomide analog 3,6′‐dithiothalidomide (3,6′‐DT) can selectively inhibit the synthesis of TNF in cultured cells. We therefore tested the therapeutic potential of 3,6′‐DT in a mouse model of focal ischemic stroke. Administration of 3,6′‐DT immediately prior to a stroke or within 3 hr after the stroke reduced infarct volume, neuronal death, and neurological deficits, whereas thalidomide was effective only when administered prior to stroke. Neuroprotection was accompanied by decreased inflammation; 3,6′‐DT‐treated mice exhibited reduced expression of TNF, interleukin‐1β, and inducible nitric oxide synthase; reduced numbers of activated microglia/macrophages, astrocytes, and neutrophils; and reduced expression of intercellular adhesion molecule‐1 in the ischemic brain tissue. 3,6′‐DT treatment attenuated stroke‐induced disruption of the blood–brain barrier by a mechanism that appears to involve suppression of matrix metalloproteinase‐9 and preservation of occludin. Treatment with 3,6′‐DT did not reduce ischemic brain damage in mice lacking TNF receptors, consistent with a critical role for suppression of TNF production and TNF signaling in the therapeutic action of 3,6′‐DT. These findings suggest that anti‐inflammatory mechanisms underlie the therapeutic actions of 3,6‐DT in an animal model of stroke. © 2013 Wiley Periodicals, Inc.
Organization and maintenance of molecular domains in myelinated axons
Authors: Buttermore Elizabeth D. , Thaxton Courtney L. , Bhat Manzoor A.
Published: February 2013

Over a century ago, Ramon y Cajal first proposed the idea of a directionality involved in nerve conduction and neuronal communication. Decades later, it was discovered that myelin, produced by glial cells, insulated axons with periodic breaks where nodes of Ranvier (nodes) form to allow for saltatory conduction. In the peripheral nervous system (PNS), Schwann cells are the glia that can either individually myelinate the axon from one neuron or ensheath axons of many neurons. In the central nervous system (CNS), oligodendrocytes are the glia that myelinate axons from different neurons. Review of more recent studies revealed that this myelination created polarized domains adjacent to the nodes. However, the molecular mechanisms responsible for the organization of axonal domains are only now beginning to be elucidated. The molecular domains in myelinated axons include the axon initial segment (AIS), where various ion channels are clustered and action potentials are initiated; the node, where sodium channels are clustered and action potentials are propagated; the paranode, where myelin loops contact with the axolemma; the juxtaparanode (JXP), where delayed‐rectifier potassium channels are clustered; and the internode, where myelin is compactly wrapped. Each domain contains a unique subset of proteins critical for the domain's function. However, the roles of these proteins in axonal domain organization are not fully understood. In this review, we highlight recent advances on the molecular nature and functions of some of the components of each axonal domain and their roles in axonal domain organization and maintenance for proper neuronal communication. © 2013 Wiley Periodicals, Inc.
Cover‐crop seeding‐date influence on fall nitrogen recovery
Authors: Hashemi Masoud , Farsad Ali , Sadeghpour Amir , Weis Sarah A. , Herbert Stephen J.
Published: February 2013

Planting cover crops after corn‐silage harvest could have a critical role in the recovery of residual N and N from fall‐applied manure, which would otherwise be lost to the environment. Experiments were conducted at the University of Massachusetts Research Farm during the 2004–2006 growing seasons. Treatments consisted of oat and winter rye cover crops, and no cover crop, and four cover‐crop dates of planting. The earliest planting dates of oat and winter rye produced the maximum biomass yield and resulted in the highest nitrate accumulation in both cover‐crop species. The average nitrate accumulation for the 3 years in winter rye and oat at the earliest time of planting was 60 and 48 kg ha–1, respectively. In 2004 where the residual N level was high, winter rye accumulated 119 kg nitrate ha–1. While initially soil N levels were relatively high in early September they were almost zero at all sampling depths in all plots with and without cover crops later in the fall before the ground was frozen. However, in plots with cover crops, nitrate was accumulated in the cover‐crop tissue, whereas in plots with no cover crop the nitrate was lost to the environment mainly through leaching. The seeding date of cover crops influenced the contribution of N available to the subsequent crop. Corn plants with no added fertilizer, yielded 41% and 34% more silage when planted after oat and rye, respectively, compared with the no–cover crop treatment. Corn‐silage yield decreased linearly when planting of cover crops was delayed from early September to early or mid‐October. Corn‐ear yield was influenced more than silage by the species of cover crop and planting date. Similar to corn silage, ear yield was higher when corn was planted after oat. This could be attributed in part to the winter‐kill of oat, giving it more time to decompose in the soil and subsequent greater release of N, while the rapidly increasing C : N ratio of rye can lessen availability to corn plants. Early plantings of cover crops increased corn‐ear yield up to 59% compared with corn‐ear yield planted after no cover crop.
Macro‐ and micronutrient‐release characteristics of three polymer‐coated fertilizers: Theory and measurements
Authors: Adams Curtis , Frantz Jonathan , Bugbee Bruce
Published: February 2013

In spite of several published studies we have an incomplete understanding of the ion‐release mechanisms and characteristics of polymer‐coated fertilizers (PCF). Here we extend current conceptual models describing release mechanisms and describe the critical effects of substrate moisture and temperature on macro‐ and micronutrient release of three PCF types: Polyon®, Nutricote®, and Osmocote®. Nutrient release was quantified at weekly intervals for up to 300 d from 5°C to 40°C in water and chemically inert sand, substrates that allowed release quantification without confounding effects of ion sorption/desorption. At least two release‐timeframe formulations of each PCF type were studied and all products had similar nutrient concentrations to allow isolation of the effect of coating technology. Contrary to several studies, our data and model indicate that there is no significant difference in nutrient‐release rates in water and a moist, solid substrate. This means that release rates determined in water can be used to model bio‐available nutrient concentrations in moist soil or soilless media where sorption/desorption properties alter concentrations after release. Across all PCF, the nutrients most affected by temperature were typically N, K, B, Cu, and Zn, while the least affected were P, Mg, and Fe. We also found consistent differences among the coating technologies. Osmocote fertilizers released faster than specified at both high and low temperatures. Nutricote had relatively steady release rates over time and a nonlinear response to temperature. Polyon released more slowly than specified but replicate samples were highly uniform.
Soil‐moisture change caused by experimental extreme summer drought is similar to natural inter‐annual variation in a loamy sand in Central Europe
Authors: Glaser Bruno , Jentsch Anke , Kreyling Juergen , Beierkuhnlein Carl
Published: February 2013

Intensification of weather extremes is currently emerging as one of the most important facets of climate change. Research frontiers are in analyzing (1) the consequences for the hydrological cycle and (2) the effects of multifactor scenarios on ecosystems. However, in all theoretical and experimental scenarios, challenges arise as to how precipitation regimes translate into variation in soil moisture. Here, we explore soil‐moisture response to experimental changes in the precipitation regime in Central Europe over a period of 5 y, particularly focusing on the effects of recurrent extreme weather events. Intraannual difference in weekly precipitation sums imposed by extreme‐drought or heavy‐rainfall manipulations clearly exceeded interannual variation in the ambient precipitation pattern during the growing season between 2005 and 2009. However, soil‐moisture variability in the experimental plots did not clearly reflect any altered patterns in response to the manipulated precipitation regime. Natural variation in soil moisture between years was similar to within‐season differences between manipulations. Strong differences in soil‐moisture dynamics during the growing season can, however, be generated by changing the temporal distribution of rainfall events while keeping the magnitude of the precipitation sum constant. Our findings confirm a common methodological dilemma in precipitation‐change experiments searching for a logical way to determine how precipitation change affects communities and ecosystems on relatively short time scales: Alteration of weather regimes according to extreme‐value statistics and future scenarios vs. systematic alteration of soil moisture. For Central Europe, our data suggest that other factors rather than the magnitude of rainfall exclusion or addition would appear to be decisive for ecosystem response to more extreme precipitation regimes. Response of soil moisture to frequency, return interval, and timing of events is a promising approach for further exploration. In addition, buffer capacity of the ecosystem under study has to be taken into account.
Natural abundance of 18O of sugar biomarkers in topsoils along a climate transect over the Central Scandinavian Mountains, Norway
Authors: Zech Michael , Tuthorn Mario , Glaser Bruno , Amelung Wulf , Huwe Bernd , Zech Wolfgang , Zöller Ludwig , Löffler Jörg
Published: February 2013

Precipitation and topsoil samples from a climate transect over the Scandinavian Mountains, Norway, were analyzed for bulk and compound‐specific δ18O values. The natural abundance of 18O in the plant‐derived hemicellulose biomarkers arabinose and xylose correlates positively with δ18O of bulk soil, but not with δ18O of precipitation. This suggests that other factors than δ18Oprec, such as evaporative 18O enrichment of leaf water, exert a strong influence on the natural abundance of 18O in soils.
Workplace Bullying: Examining Self‐Monitoring and Organizational Culture
Authors: O'Farrell Colin , Nordstrom Cynthia R.
Published: February 2013

Workplace bullying is both prevalent and underresearched. Bullying includes such dysfunctional behavior as sexual harassment, social exclusion, name‐calling, slandering, and physical assaults. Bullying results in negative outcomes for both individual employees and organizations. Individuals experience stress and other physiological and psychological outcomes, and organizations register detrimental effects on productivity, absenteeism, and turnover. This research examined whether employees low in self‐monitoring and working in chaotic organizational cultures were more likely to be victimized by bullies. Results indicated that employees working in chaotic organizations (i.e., lacking transparency, accountability, and appropriate rewards and guidelines) experienced more bullying. Results are discussed with regard to establishing appropriate cultural cues to minimize organizational bullying.
Study on the 3‐hydroxy‐3‐methyl‐glutaryl CoA reductase inhibitory properties of Agaricus bisporus and extraction of bioactive fractions using pressurised solvent technologies
Authors: Gil‐Ramírez Alicia , Clavijo Cristina , Palanisamy Marimuthu , Ruiz‐Rodríguez Alejandro , Navarro‐Rubio María , Pérez Margarita , Marín Francisco R , Reglero Guillermo , Soler‐Rivas Cristina
Published: February 2013

BACKGROUND

Agaricus bisporus mushrooms were able to lower cholesterol levels in hypercholesterolaemic rats and it was suggested that dietary fibre might inhibit cholesterol absorption. However, A. bisporus extracts were also able to inhibit the 3‐hydroxy‐3‐methyl‐glutaryl CoA reductase (HMGCR, the key enzyme in the cholesterol biosynthetic pathway) and this might also contribute to the observed lowering of cholesterol levels in serum.

RESULTS

The methanol–water extracts obtained from A. bisporus were able to inhibit up to 60% the HMGCR activity using an in vitro assay. The HMGCR inhibitory capacities depended on cultivation conditions, strains, etc. The potential inhibitors were not statins, they might be β‐glucans able to scavenge the substrate and impair the enzymatic reaction. They were present during all mushroom developmental stages and similarly distributed through all the tissues including the parts discarded as a by‐product. Accelerated solvent extractions using 1:1 ethanol–water as pressurised solvent (10.7 MPa, 25°C, five cycles of 5 min) were more effective in the extraction of the HMGCiR inhibitor(s) than supercritical fluid extractions (9 MPa, 40°C) using CO2 with 10% ethanol.

CONCLUSION

A mushroom cultivation and two extraction procedures were optimised to obtain fractions from A. bisporus with high HMGCR inhibitory activities to design novel ingredients for hypocholesterolaemic functional foodstuffs. © 2013 Society of Chemical Industry
Prospective Evaluation of Single-Operator Peroral Cholangioscopy in Liver Transplant Recipients Requiring an Evaluation of the Biliary Tract
Authors: Balderramo Domingo , Sendino Oriol , Miquel Rosa , de Miguel Cristina Rodriguez , Bordas Josep M. , Martinez-Palli Graciela , Leoz Maria L. , Rimola Antoni , Navasa Miguel , Llach Josep , Cardenas Andrés
Published: February 2013

In this descriptive study, we examined the role of single-operator cholangioscopy (SOC) in the evaluation of biliary complications after liver transplantation (LT). We prospectively included adult recipients of deceased donor LT who were referred for endoscopic retrograde cholangiopancreatography between June 2009 and July 2011. All patients underwent SOC with biopsy of the biliary anastomosis. Sixteen patients were included: 12 with biliary anastomotic strictures (ASs), 2 with common bile duct stones, 1 with a bile leak, and 1 with sphincter of Oddi dysfunction. Patients with ASs displayed 1 of 2 patterns: (A) mild erythema (n = 9) or (B) edema, ulceration, and sloughing (n = 3). Those without ASs displayed a pale mucosa with mild edema at the anastomosis. Patients with ASs and pattern B required a longer period of stenting than patients with pattern A (457 versus 167 days, P = 0.02). In addition, patients with pattern A had a better response and better resolution of their strictures with endoscopic therapy than those with pattern B (66% versus 33%, P = 0.13). Histological examinations of ASs showed nonspecific intraepithelial inflammation in patients with patterns A and B. Biopsy samples from patients without ASs showed normal columnar epithelial bile duct cells. The total cholangioscopy time for all procedures was 26.8 ± 10.1 minutes. In conclusion, SOC in LT recipients is feasible and allows adequate visualization and tissue sampling of ASs and bile ducts. Two distinct visual patterns that are easily identified with SOC may help to predict the outcomes of endoscopic therapy in patients with biliary complications after LT. Liver Transpl 19:199-206, 2013. © 2012 AASLD.
Increased morbidity in overweight and obese liver transplant recipients
Authors: Hakeem Abdul R. , Cockbain Andrew J. , Raza Syed S. , Pollard Stephen G. , Toogood Giles J. , Attia Magdy A. , Ahmad Niaz , Hidalgo Ernest L. , Prasad Raj K. , Menon Krishna V.
Published: February 2013

Obesity levels in the United Kingdom have risen over the years. Studies from the United States and elsewhere have reported variable outcomes for obese liver transplant recipients in terms of post–liver transplant morbidity, mortality, and graft survival. This study was designed to analyze the impact of the body mass index (BMI) on outcomes following adult liver transplantation. Data from 1994 to 2009 were retrieved from a prospectively maintained database. Patients were stratified into 5 World Health Organization BMI categories: underweight (<18.5 kg/m2), normal weight (18.5-24.9 kg/m2), overweight (25.0-29.9 kg/m2), obese (30.0-34.9 kg/m2), and morbidly obese (≥35.0 kg/m2). The primary outcome was an evaluation of graft and patient survival, and the secondary outcome was an assessment of postoperative morbidity. Bonferroni correction was applied with statistical significance set at P < 0.012. Kaplan-Meier curves were used to study the effects of BMI on graft and patient survival. A total of 1325 patients were included in the study: underweight (n = 47 or 3.5%), normal-weight (n = 643 or 48.5%), overweight (n = 417 or 31.5%), obese (n = 145 or 10.9%), and morbidly obese patients (n = 73 or 5.5%). The rate of postoperative infective complications was significantly higher in the overweight (60.7%, P < 0.01) and obese recipients (65.5%, P < 0.01) versus the normal-weight recipients (50.4%). The morbidly obese patients had a longer mean intensive care unit (ICU) stay than the normal-weight patients (4.7 versus 3.2 days, P = 0.03). The mean hospital stay was longer for the overweight (22.4 days, P < 0.001), obese (21.3 days, P = 0.04), and morbidly obese recipients (22.4 days, P = 0.047) versus the normal-weight recipients (18.0 days). There was no difference in death-censored graft survival or patient survival between the groups. In conclusion, this is the largest and only reported UK series on BMI and outcomes following liver transplantation. Overweight and obese patients have significantly increased morbidity in terms of infective complications after liver transplantation and, consequently, longer ICU and hospital stays. Liver Transpl 19:551–562, 2013. © 2013 AASLD.
Sorafenib delays recurrence and metastasis after liver transplantation in a rat model of hepatocellular carcinoma with high expression of phosphorylated extracellular signal-regulated kinase
Authors: Yan Jun , Tan Changjun , Gu Fangming , Jiang Jiahao , Xu Min , Huang Xiuzhen , Dai Zhi , Wang Zheng , Fan Jia , Zhou Jian
Published: February 2013

Liver transplantation (LT) is one of the curative treatments for hepatocellular carcinoma (HCC). However, cancer recurrence and metastasis after LT are common in some HCC patients with high-risk factors (even in those within the Milan criteria). It remains unclear whether adjuvant therapy with sorafenib inhibits HCC recurrence and metastasis after LT. Therefore, we performed orthotopic LT in an August Irish Copenhagen (ACI) rat model of HCC. Because LT involves immune rejection and tolerance and it is unknown whether sorafenib influences the immune response, we also investigated the effects of sorafenib on immune balance. In this study, we established an allogeneic rat LT model in which liver grafts were taken from Lewis rats and transplanted into ACI rats with orthotopic HCC, and they were administered cyclosporine A to prevent acute allograft rejection. From day 7 after LT, sorafenib was administrated at 30 mg/kg/day for 3 weeks. Our results showed that the serum levels of vascular endothelial growth factor and hepatocyte growth factor significantly increased after LT, and the T helper 1 (Th1)/T helper 2 (Th2) immune balance was shifted toward a Th2 response after immunosuppressant administration. In comparison with controls, the rats in the sorafenib group showed significantly inhibited extracellular signal-regulated kinase phosphorylation and improved progression-free survival and overall survival. The tumor proliferation rate and angiogenesis in posttransplant recurrent tumor tissues decreased in the sorafenib group, and the tumor apoptosis rate increased. There was no significant difference in the Th1/Th2 immune balance between the sorafenib and control groups. In conclusion, adjuvant therapy with sorafenib is highly effective at inhibiting cancer recurrence and metastasis without influencing the immune balance after LT for HCC with high expression of phosphorylated extracellular signal-regulated kinase. This study suggests that sorafenib may have potential, particularly as part of a stratified medicine approach to HCC treatment after LT. Liver Transpl 19:507–520, 2013. © 2013 AASLD.
Impact of placebo assignment in clinical trials of tic disorders
Authors: Cubo Esther , González Miguel , Singer Harvey , Mahone E. Mark , Scahill Lawrence , Müller‐Vahl Kirsten R. , de la Fuente‐Fernández Raul , Armesto Diana , Kompoliti Katie
Published: February 2013

Background

Understanding the impact of placebo treatment is pivotal to the correct interpretation of clinical trials. The aim of present study was to examine the placebo effect in tic disorders.

Methods

Raw data were obtained for 6 placebo‐controlledparallel and cross‐over trials that involved medical interventions for tic disorders. Tic severity was measured using the Yale Global Tic Severity Scale. Placebo effect was defined as an improvement of at least 30% over baseline scores in the total tic score and was considered clinically relevant when at least 10% of patients in the placebo‐arm met that benchmark.

Results

In total, 91 placebo‐treated patients (80% males; mean age, 16.5 years; standard deviation, 10.5 years) were included. Although there was a trend toward improvement in the total tic scores after placebo administration (P=0.057), the magnitude of the placebo effect was small (Cohen's d=0.16) but relevant (19% of the sample). Females were more likely than males to have a placebo effect.

Conclusions

The magnitude of the placebo effect in tic disorders appeared to be small. Further longitudinal studies using objective assessments for tic disorders are warranted to confirm the current results. © 2013 Movement Disorder Society
Barriers to research utilization by registered nurses in Taiwan
Authors: Chen Su‐Hui , Shao Jung‐Hua , Hsiao Ya‐Chu , Lee Hsiang‐Chun
Published: February 2013

This cross‐sectional study was designed to identify barriers to research utilization among registered nurses (N = 510) in clinical settings in Taiwan. Data were collected by mailed survey. Barriers were measured by the Barriers to Research Utilization Scale‐Chinese version, which has four subscales: characteristics of the adopter (nurse), organization (setting barriers and limitations), innovation (research qualities), and communication (presentation/accessibility of the research). Research utilization was predicted by frequency of reading professional literature, years of research experience, hospital classification, and the barriers of communication, innovation, and adopter characteristics. These findings indicate the need to enhance Taiwanese nurses' research efficacy, research‐based information, and research experiences. Nursing administrators should create a research‐friendly climate and support implementing research findings. © 2013 Wiley Periodicals, Inc. Res Nurs Health 36:191–202, 2013
Linking RN workgroup job satisfaction to pressure ulcers among older adults on acute care hospital units
Authors: Choi JiSun , Bergquist‐Beringer Sandra , Staggs Vincent S.
Published: February 2013

We examined the relationship between registered nurse (RN) workgroup job satisfaction and hospital‐acquired pressure ulcers (HAPUs) among older adults on six types of acute care units. Random‐intercept logistic regression analyses were performed using 2009 unit‐level data from the National Database of Nursing Quality Indicators® (NDNQI®) and the NDNQI RN Survey. Overall, RN workgroup job satisfaction was negatively associated with HAPU rates, although the relationship varied by unit type. RN workgroup satisfaction was significantly associated with HAPU rates on critical care, medical, and rehabilitation units. No significant association was found on step‐down, surgical, and medical‐surgical units. Findings provide evidence that higher RN workgroup job satisfaction is related to lower HAPU rates among older adult patients in acute care hospitals. © 2013 Wiley Periodicals, Inc. Res Nurs Health 36:181–190, 2013
Psychosocial factors associated with diet quality in a working adult population
Authors: Ferranti Erin Poe , Dunbar Sandra B. , Higgins Melinda , Dai Jun , Ziegler Thomas R. , Frediani Jennifer K. , Reilly Carolyn , Brigham Kenneth L.
Published: February 2013

The associations between specific intra‐ and inter‐personal psychosocial factors and dietary patterns were explored in a healthy, working adult sample of university and health center employees (N = 640) who were enrolled in a prospective predictive health study. Participants had a mean age of 48 (SD = 11) years and were 67% women and 30% minority. Baseline psychosocial measures of perceived stress, depressive symptoms, social support, and family functioning were examined for their relationships with three diet quality indices—AHEI, DASH, and the Mediterranean. Dietary intake was of moderate quality in this high‐income, well‐educated, psychosocially healthy population. Social support was positively associated with better diet quality for all three indices (p < .01). Further research should focus on socio‐environmental factors associated with diet quality. © 2013 Wiley Periodicals, Inc. Res Nurs Health 36:242–256, 2013
Improving statistical analysis of matched case–control studies
Authors: Conway Aaron , Rolley John X. , Fulbrook Paul , Page Karen , Thompson David R.
Published: February 2013

Matched case–control research designs can be useful because matching can increase power due to reduced variability between subjects. However, inappropriate statistical analysis of matched data could result in a change in the strength of association between the dependent and independent variables or a change in the significance of the findings. We sought to ascertain whether matched case–control studies published in the nursing literature utilized appropriate statistical analyses. Of 41 articles identified that met the inclusion criteria, 31 (76%) used an inappropriate statistical test for comparing data derived from case subjects and their matched controls. In response to this finding, we developed an algorithm to support decision‐making regarding statistical tests for matched case–control studies. © 2013 Wiley Periodicals, Inc. Res Nurs Health 36:320–324, 2013
Dispersion optimization of exfoliated graphene nanoplatelet in polyetherimide nanocomposites: Extrusion, precoating, and solid state ball milling
Authors: Wu Huang , Rook Brian , Drzal Lawrence T.
Published: February 2013

Polyetherimide (PEId) nanocomposites reinforced with exfoliated graphite (graphene) nanoplatelets (GNP) were fabricated by various processing methods to achieve good dispersion including: melt‐extrusion, precoating, solid state ball milling (SSBM) as well as combinations of these methods. As a result of the precoating approach, the electrical conductivity is greatly increased with a percolation threshold as low as 2 wt% as compared to 10 wt% for melt‐extrusion, with the cost of lower mechanical properties. SSBM was investigated as an alternative process to enhance dispersion, adhesion and to reduce GNP size. High electrical conductivity and improved modulus were achieved by this approach. Further improvements to the mechanical properties could be made by combining the extrusion and SSBM approaches. Examination of the nanocomposite morphology explains the effect of these combined compounding approaches on GNP particle dispersion and their relation to the improved GNP/PEId nanocomposite performance. POLYM. COMPOS., 2013. © 2013 Society of Plastics Engineers
Nonisothermal crystallization kinetics of AB2 hyperbranched polymer‐filled polypropylene
Authors: Liu Guangtian , Lei Jing , Wang Fengyan
Published: February 2013

In this article, nonisothermal crystallization kinetics of polypropylene (PP) and AB2 hyperbranched polymer (HBP)‐filled PP have been investigated by differential scanning calorimetry. The Avrami analysis modified by Mandelkern and a method combined with Avrami and Ozawa equations were employed to describe successfully the nonisothermal crystallization kinetics of samples. The conclusion showed that HBP can prompt crystallization effectively. Furthermore, in blends of different HBP contents, the value of t1/2 became smaller with increasing HBP content; however, the crystallization rate of the blend decreased slightly when content of HBP is 5%. An increase in the Avrami exponent showed that addition of HBP influenced the mechanism of nucleation and the growth of PP crystallites. The possible explanation could be attributed to the fractal structure of HBP. The polarized micrographs showed that HBP acts as a heterogeneous nucleation agent, and the nucleation efficiency has increased remarkably in HBP/PP blends. POLYM. ENG. SCI., 53:2535–2540, 2013. © 2013 Society of Plastics Engineers
A study of the deformation‐induced whitening phenomenon for cavitating and non‐cavitating semicrystalline polymers
Authors: Farge Laurent , Andre Stéphane , Pawlak Andrzej , Baravian Christophe , Irvine Sarah C. , Philippe Adrian‐Marie
Published: February 2013

In this work, we used two techniques to study the deformation‐induced whitening phenomenon that occurs when certain semicrystalline polymers (SCPs) are subjected to tensile drawing: (1) IPLST (Incoherent Polarized Steady Light Transport) was used for characterizing the light scatterers and in particular for determining their size. (2) SRXTM (Synchrotron Radiation X‐Ray Tomographic Microscopy) was used to visualize the internal structure of the deformed SCPs. In particular, with this technique the possible presence of micrometric cavities can be detected. In the early whitening stage of a cavitating polypropylene (PP), the IPLST technique was found to show that the size of the light scatterers is larger than 1 μm. At the same time, the SRXTM measurements showed that no void larger than 1 μm was present in the material. The micrometric light scatterers responsible for the whitening phenomenon may thus not be simple cavities. In fact, this experimental study suggests that they correspond to areas where smaller objects (possibly nanovoids) are highly confined. At the scale of visible wavelengths, these regions could scatter visible light like individual entities of micrometric size. The study also showed that the size of cavities observable using SRXTM for a very deformed PP is dependent on the initial dimensions of the spherulites. Results previously obtained for a non‐cavitating high density polyethylene are also briefly presented in this article to confirm the theory that deformation‐induced‐whitening phenomenon may have various origins for such complex microstructuring. © 2013 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys., 2013
Confined glassy properties of polymer nanoparticles
Authors: Zhang Chuan , Guo Yunlong , Priestley Rodney D.
Published: February 2013

For nearly the past two decades, significant effort has been devoted to pursuing an understanding of the glass transition temperature and associated dynamics of polymers confined to the nanoscale. Without question, we know more about the glassy properties of confined polymers today than we knew two decades ago or even a decade ago. Much of our understanding has been obtained via studies on thin polymer films, as they are facile to process and are of substantial technological importance. Nevertheless, studies on polymers confined to other geometries are becoming increasingly more important as we pursue questions difficult to address using thin films and as technology demands the use of confined polymers beyond thin films. In this feature article, we highlight the impact of nanoscale confinement on the glassy properties of polymer nanoparticles. Although the emphasis is placed on contributions from our work, a discussion of the related literature is also presented. Our aim is to elucidate commonalities or fundamental differences in the deviations of glassy properties from the bulk for polymers confined to different geometries. © 2013 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2013
Modeling cellular compartmentation in one‐carbon metabolism
Authors: Scotti Marco , Stella Lorenzo , Shearer Emily J. , Stover Patrick J.
Published: February 2013

Folate‐mediated one‐carbon metabolism (FOCM) is associated with risk for numerous pathological states including birth defects, cancers, and chronic diseases. Although the enzymes that constitute the biological pathways have been well described and their interdependency through the shared use of folate cofactors appreciated, the biological mechanisms underlying disease etiologies remain elusive. The FOCM network is highly sensitive to nutritional status of several B‐vitamins and numerous penetrant gene variants that alter network outputs, but current computational approaches do not fully capture the dynamics and stochastic noise of the system. Combining the stochastic approach with a rule‐based representation will help model the intrinsic noise displayed by FOCM, address the limited flexibility of standard simulation methods for coarse‐graining the FOCM‐associated biochemical processes, and manage the combinatorial complexity emerging from reactions within FOCM that would otherwise be intractable. WIREs Syst Biol Med 2013, 5:343–365. doi: 10.1002/wsbm.1209

This article is categorized under:

Analytical and Computational Methods > Dynamical Methods

Biological Mechanisms > Metabolism

Physiology > Mammalian Physiology in Health and Disease
Coupling spans of the Higgs-like boson
Authors: Dobrescu Bogdan A. , Lykken Joseph D.
Published: February 2013

Abstract

Using the LHC and Tevatron data, we set upper and lower limits on the total width of the Higgs-like boson. The upper limit is based on the well-motivated assumption that the Higgs coupling to a W or Z pair is not much larger than in the Standard Model. These width limits allow us to convert the rate measurements into ranges for the Higgs couplings to various particles. A corollary of the upper limit on the total width is an upper limit on the branching fraction of exotic Higgs decays. Currently, this limit is 47% at the 95% CL if the electroweak symmetry is broken only by doublets.
In vivo magnetic resonance imaging of mice liver tumors using a new gadolinium‐based contrast agent
Authors: Chen Shih‐Hsien , Kuo Yu‐Ting , Cheng Tian‐Lu , Chen Chiao‐Yun , Chiu Yen‐Yu , Lai Jui‐Jen , Chang Chih‐Ching , Jaw Twei‐Shiun , Wang Yun‐Ming , Liu Gin‐Chung
Published: February 2013

We compared the enhancement effect between a newly synthesized tissue‐specific contrast agent, [Gd‐DOTA‐FPβG], and a commercially available agent, [Gd(DOTA)]−, in a murine model of liver tumor using a clinical magnetic resonance imaging scanner. The colon cancer cell lines with and without β‐glucuronidase (βG) expression were implanted into the liver of mice. Self‐synthesized gadolinium‐based magnetic resonance contrast agent, [Gd(DOTA‐FPβG)], was administered to measure enhancement on magnetic resonance images using a commercially available agent, [Gd(DOTA)]−, as control in a clinical 3.0 tesla (T) magnetic resonance scanner. In vivo fluorescence imaging and histopathology of the liver were also performed to compare and correlate with the magnetic resonance studies. The in vivo fluorescence imaging failed to depict a sufficiently intense signal for liver or liver tumor of mice without exposure of the liver following an incision on the abdominal wall. The tissue‐specific magnetic resonance agent, [Gd(DOTA‐FPβG)], caused significantly stronger enhancement in tumors expressing βG (CT26/mβG‐eB7) than in tumors not expressing βG (CT26) (p < 0.05). In the magnetic resonance imaging studies using control agent [Gd(DOTA)]−, the tumors with and without βG expression depicted no significant difference in enhancement on the T1‐weighted images. The [Gd(DOTA‐FPβG)] also provided significantly more contrast uptake in the CT26/mβG‐eB7 tumor than in the normal liver parenchyma, whereas the [Gd(DOTA)]− did not. This study confirms that better contrast enhancement can be readily detected in vivo by the use of a tissue‐specific magnetic resonance contrast agent to target tumor cells with specific biomarkers in a clinical magnetic resonance imaging scanner.
THE REGULAR GRAPH OF A NONCOMMUTATIVE RING
Authors: AKBARI S. , HEYDARI F.
Published: February 2013

Let $R$ be a ring and $Z(R)$ be the set of all zero-divisors of $R$. The total graph of $R$, denoted by $T(\Gamma (R))$ is a graph with all elements of $R$ as vertices, and two distinct vertices $x, y\in R$ are adjacent if and only if $x+ y\in Z(R)$. Let the regular graph of $R$, $\mathrm{Reg} (\Gamma (R))$, be the induced subgraph of $T(\Gamma (R))$ on the regular elements of $R$. In 2008, Anderson and Badawi proved that the girth of the total graph and the regular graph of a commutative ring are contained in the set $\{ 3, 4, \infty \} $. In this paper, we extend this result to an arbitrary ring (not necessarily commutative). We also prove that if $R$ is a reduced left Noetherian ring and $2\not\in Z(R)$, then the chromatic number and the clique number of $\mathrm{Reg} (\Gamma (R))$ are the same and they are ${2}^{r} $, where $r$ is the number of minimal prime ideals of $R$. Among other results, we show that if $R$ is a semiprime left Noetherian ring and $\mathrm{Reg} (R)$ is finite, then $R$ is finite.