bluuebunny/crossref_metadata_2025 huggingface dataset:
Direct Electrochemistry of Glucose Oxidase Immobilized at a Novel Composite Material β‐Cyclodextrin/poly(4‐aminothiophenol)/Au Nanoparticle Modified Electrode
Authors: Sheng Qing‐Lin , Luo Kai , Liu Rui‐Xiao , Zheng Jian‐Bin
Published: January 2012

A novel complex material was fabricated by three steps. In the first step, gold nanoparticle (Aunano) was prepared with the method of chemistry and dialysis. In the second step, 4‐aminothiophenol (AT) was encapsulated in the cavity of β‐cyclodextrin and formed inclusion complex, cyclodextrin/4‐aminothiophenol (CD/AT). And then inclusion complex was adsorbed to the surface of Aunano based on the bond of Au‐S interaction. In the last step, a complex material, cyclodextrin/poly(4‐aminothiophenol)‐Au nanoparticles (CD/PAT‐Aunano) was obtained by the polymerizing in the acid solution initiated by chlorauric acid. The CD/PAT‐Aunano has spherical nanostructure with the average diameter of 55 nm. Glucose oxidase (GOx) was anchored with this complex material and direct electrochemistry of GOx was achieved. A couple of stable and well‐defined redox peaks were observed with the formal potential (E0′) of ‐0.488 V (vs. SCE) in a pH 6.98 buffer solution. The GOx modified electrode also exhibited an excellent electrocatalytic activity to the reduction of glucose, a linearity range for determination of glucose is from 0.25 mM to 16.0 mM with a detection limit of 0.09 mM (S/N = 3). This protocol had potential application to fabricate the third‐generation biosensor.
Paraptosis accompanied by autophagy and apoptosis was induced by celastrol, a natural compound with influence on proteasome, ER stress and Hsp90
Authors: Wang Wen‐Bo , Feng Li‐Xing , Yue Qing‐Xi , Wu Wan‐Ying , Guan Shu‐Hong , Jiang Bao‐Hong , Yang Min , Liu Xuan , Guo De‐An
Published: January 2012

In the present study, we found that celastrol, a natural compound with well‐known apoptosis‐inducing effect, could also induce paraptosis‐like cytoplasmic vacuolization in cancer cell lines including HeLa cells, A549 cells and PC‐3 cells derived from cervix, lung and prostate, respectively. Further study using HeLa cells indicated that the vacuoles induced by celastrol might be derived from dilation of endoplasmic reticulum. And, in celastrol‐treated cells, markers of autophagy such as transformation of microtubule‐associated protein 1 light chain 3 (LC3)I to LC3II and LC3 punctates formation were identified. Interestingly, autophagy inhibitors could not interrupt but enhance the induction of cytoplasmic vacuolization. Furthermore, MAPK pathways were activated by celastrol and inhibitors of MEK and p38 pathways could prevent the formation of cytoplasmic vacuolization. Celastrol treatment also induced G2/M cell cycle arrest and apoptosis in HeLa cells. In conclusion, celastrol induced a kind of paraptosis accompanied by autophagy and apoptosis in cancer cells. The coincidence of apoptosis and autophagy together with paraptosis might contribute to the unique characteristics of paraptosis in celastrol‐treated cells such as the dependence of paraptosis on MAPK pathways and dynamic change of LC3 proteins. Both paraptosis and apoptosis could contribute to the cell death induced by celastrol while autophagy might serve as a kind of survival mechanism. The potency of celastrol to induce paraptosis, apoptosis and autophagy at the same dose might be related to its capability to affect a variety of pathways including proteasome, ER stress and Hsp90. J. Cell. Physiol. 227: 2196–2206, 2012. © 2011 Wiley Periodicals, Inc.
Intensification of 1‐phenylethanol production by periodical membrane extraction of the product from fermentation broth
Authors: Mihal' Mário , Markoš Jozef , Annus Július , Štefuca Vladimír
Published: January 2012

BACKGROUND: Enantioselective bioreduction of acetophenone to S‐(−)‐1‐phenylethanol by Saccharomyces cerevisiae under non‐growth conditions is inhibited by the product created. This study investigated the possibility of intensification and mathematical simulation of 1‐phenylethanol production using periodic product removal carried out by membrane extraction in a hollow fiber membrane module.

RESULTS: The highest reaction rate was observed at the beginning of the biotransformation. With increased product concentration in the reaction medium, the reaction rate gradually decreased by about 50% after 20 h of biotransformation. The low concentration of product maintained in the reaction medium using membrane extraction had positive influence on the 1‐phenylethanol production with a high yield (96%) and mean reaction rate of 0.226 mg h−1g−1, 35% higher than biotransformation without product removal. The equilibrium change and membrane fouling caused by biomass were not significant. It was possible to mathematically simulate the whole course of the extractive biotransformation with good agreement with experimental data.

CONCLUSION: Bioreductive production of 1‐phenylethanol is more effective when using periodic membrane extraction of the product from the fermentation broth, which gives higher reaction rate, higher yield and simpler downstream process than biotransformation without product removal. Copyright © 2012 Society of Chemical Industry
Proton exchange reactions in isotope chemistry (I)
Authors: Jian Zhigang , Ray Tapan , Wu Amy , Jones Lawrence
Published: January 2012

Direct H–D exchange reactions were applied to the preparations of stable isotope‐labeled TKI258 and two TKI258 metabolites. Each compound was made in one single H–D exchange reaction with excellent isotope incorporation. The number of deuterium incorporation and deuterium distribution in the molecules was similar in all three compounds. Stable isotope‐labeled TKI258 was also prepared from d8‐methylpiperazine in a multistep synthesis.
Oncologic applications of diffusion‐weighted MRI in the body
Authors: Bonekamp Susanne , Corona‐Villalobos Celia P. , Kamel Ihab R.
Published: January 2012

Diffusion‐weighted MRI (DWI) allows the detection of malignancies in the abdomen and pelvis. Lesion detection and characterization using DWI largely depends on the increased cellularity of solid or cystic lesions compared with the surrounding tissue. This increased cellularity leads results in restricted diffusion as indicated by reduction in the apparent diffusion coefficient (ADC). Low pretreatment ADC values of several malignancies have been shown to be predictive of better outcome. DWI can assess response to systemic or regional treatment of cancer at a cellular level and will therefore detect successful treatment earlier than anatomical measures. In this review, we provide a brief technical overview of DWI, discuss quantitative image analysis approaches, and review studies which have used DWI for the purpose of detection and characterization of malignancies as well as the early prediction of treatment response. J. Magn. Reson. Imaging 2012;257–279. © 2011 Wiley Periodicals, Inc.
Real‐time magnetic resonance imaging of normal swallowing
Authors: Zhang Shuo , Olthoff Arno , Frahm Jens
Published: January 2012

Purpose:

To evaluate the use of a novel real‐time magnetic resonance imaging (MRI) technique for the assessment of normal swallowing dynamics.

Materials and Methods:

In a cohort of 10 healthy subjects, real‐time MRI movies at 24.3 frames per second were obtained in sagittal, coronal, and axial orientation during self‐controlled swallows of 5 mL pineapple juice as oral contrast bolus. All studies were performed with the use of a commercial MRI system at 3 T combining two sets of radiofrequency receiver coils. Real‐time movies relied on a fast low‐angle shot (FLASH) MRI sequence with radial undersampling and image reconstruction by nonlinear inversion yielding 41.23 msec acquisition time for an in‐plane resolution of 1.5 mm. Evaluations focused on clinical image quality as well as visualization and temporal quantification of distinct swallowing functions.

Results:

Throughout the entire process, the swallowing dynamics were well depicted and characterized with almost no visible image artifacts in all subjects. The mid‐sagittal plane turned out to be most valuable. The movies allowed for a quantitative determination of the temporal pattern of all swallowing events.

Conclusion:

The proposed real‐time MRI technique yields noninvasive, robust, and quantitative access to the physiology of normal swallowing in healthy subjects at high temporal resolution and image quality. J. Magn. Reson. Imaging 2012;35:1372–1379. © 2012 Wiley Periodicals, Inc.
B2A peptide induces chondrogenic differentiation in vitro and enhances cartilage repair in rats
Authors: Lin Xinhua , Shanmugasundaram Shobana , Liu Yi , Derrien Alexandrine , Nurminskaya Maria , Zamora Paul O.
Published: January 2012

This study investigated whether the synthetic peptide B2A (B2A2‐K‐NS) could induce in vitro chondrogenic differentiation and enhance the in vivo repair of damaged cartilage in an osteoarthritis model. In vitro, micromass cultures of murine and human stem cells with and without B2A were used as models of chondrogenic differentiation. Micromasses were evaluated for gene expression using microarray analysis and quantitative PCR; and for extracellular matrix production by Alcian blue staining for sulfated glycosaminoglycan and immunochemical detection of collagen type II. In vivo, osteoarthritis was chemically induced in knees of adult rats by an injection of mono‐iodoacetate (MIA) into the synovial space. Treatment was administered at 7‐ and 14 days after the MIA by injection into the synovial space of B2A or saline and terminated at 21 days, after which knee cartilage damage was determined and scored by histological analysis. In murine C3H10T1/2 micromass culture, B2A induced the expression of more than 11 genes associated with growth factors/receptors, transcription, and the extracellular matrix, including PDGF‐AA. B2A also significantly increased the sulfated glycosaminoglycan and collagen of murine‐ and human micromass cultures. In the knee osteoarthritis model, B2A treatment enhanced cartilage repair compared to untreated knees as determined histologically by a decrease in damage indicators. These findings suggest that B2A induces stem cells chondrogenic differentiation in vitro and enhances cartilage repair in vivo. The results suggest that B2A might be useful to promote cartilage repair. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1221–1228, 2012
Variation and pattern in the responses of mammal faunas to Late Pleistocene climatic change in southeastern South Australia
Authors: Macken Amy C. , Prideaux Gavin J. , Reed Elizabeth H.
Published: January 2012

We examined mammal occurrence and variability through the Late Pleistocene vertebrate fossil deposit of Grant Hall in Victoria Fossil Cave, Naracoorte, South Australia. To determine long‐term patterns of change, we compared the composition and relative abundance trends of the assemblage with a nearby Middle Pleistocene deposit in Cathedral Cave. Total species richness did not change through the Grant Hall sequence, dated from 93 ± 8 to 70 ± 5 ka. However, species relative abundances varied between ecologically divergent species, and in some cases between species that demonstrate similar environmental preferences. For some species this variation is comparable to that recorded in Cathedral Cave. Of those showing similar trends between the two deposits, the forest inhabitant, Pseudomys fumeus, recorded an 8.6% decline through Grant Hall, coincident with a 9.7% increase in the dry heath/mallee dweller Pseudomys apodemoides. These patterns indicate that climatic transition from relatively warm, moist to cooler, drier conditions impacted some species in similar ways through climatic cycles of the past. However, the majority of the fauna demonstrated complex responses that are individual and variable through time. Statistical tests of species trends from the Grant Hall assemblage caution that large fossil samples are required to validate patterns observed. Copyright © 2012 John Wiley & Sons, Ltd.
α‐Glucosidase‐ and α‐amylase‐inhibitory activities of phlorotannins from Eisenia bicyclis
Authors: Eom Sung‐Hwan , Lee Sang‐Hoon , Yoon Na‐Young , Jung Won‐Kyo , Jeon You‐Jin , Kim Se‐Kwon , Lee Myung‐Suk , Kim Young‐Mog
Published: January 2012

BACKGROUND: In an effort to develop alternative therapeutic agents, strong inhibitory activity against α‐glucosidase and α‐amylase was detected in Eisenia bicyclis methanolic extract.

RESULTS: In this study, two phlorotannins were isolated from E. bicyclis and characterised by chromatography and nuclear magnetic resonance. The active substances were identified as fucofuroeckol A (FF) and dioxinodehydroeckol (DD). To the authors' knowledge, this is the first report of the identification of these substances in E. bicyclis. However, to date, no antidiabetic activity of FF and DD has been reported. Both phlorotannins demonstrated significant inhibitory activity against α‐glucosidase and α‐amylase. FF showed potent antidiabetic activity, with IC50 values of 131.34 nmol L−1 against α‐glucosidase and 42.91 µmol L−1 against α‐amylase. The corresponding IC50 values of DD were 93.33 nmol L−1 and 472.7 µmol L−1. Furthermore, kinetic analysis revealed that FF and DD exhibited non‐competitive inhibitory activity against α‐glucosidase.

CONCLUSION: These results suggest that FF and DD may be candidates for the development of an antidiabetic pharmaceutical agent or food additive. Copyright © 2012 Society of Chemical Industry
Using modified soy protein to enhance foaming of egg white protein
Authors: Wang Guang , Troendle Molly , Reitmeier Cheryll A , Wang Tong
Published: January 2012

BACKGROUND: It is well known that the foaming properties of egg white protein are significantly reduced when a small amount of yolk is mixed in the white. To improve foaming properties of yolk‐contaminated egg white protein, soy protein isolate (SPI) and egg proteins were modified to make basic proteins, and effects of these modified proteins on egg white foaming were evaluated in a model and an angel cake system.

RESULTS: SPI and egg yolk proteins were modified to have an isoelectric point of 10, and sonication was used to increase protein dispersibility after the ethyl esterification reaction. However, only the addition of sonicated and modified SPI (SMSPI) showed improvement of foaming in the 5% egg protein model system with 0.4% yolk addition. SMSPI was then used in making angel food cake to examine whether the cake performance reduction due to yolk contamination of the white would be restored by such alkaline protein. Cake performance was improved when cream of tartar was used together with SMSPI.

CONCLUSION: Basic soy protein can be made and used to improve egg white foaming properties and cake performance. Copyright © 2012 Society of Chemical Industry
Radiofrequency ablation combined with systemic chemotherapy in nasopharyngeal carcinoma liver metastases improves response to treatment and survival outcomes
Authors: Jin Ying , Cai Yu‐Chen , Cao Ye , Cai Xiu‐Yu , Tan Yu‐Ting , Shi Yan‐Xia , Jiang Wen‐Qi
Published: January 2012

Background

Systemic chemotherapy is the major treatment modality for nasopharyngeal carcinoma (NPC) liver metastases. We investigated the effectiveness of radiofrequency ablation (RFA) treatment, which has not been well explored in this disease.

Methods

One‐hundred and thirty‐four cases of NPC with liver metastases treated with chemotherapy, chemotherapy with RFA, or RFA alone were retrospectively analyzed. Patient survival was evaluated by the log‐rank test. Survival was analyses using the Kaplan–Meier method. Cox multivariate analyses of clinicopathological features and different treatment approaches were conducted.

Results

Local response rates were 58% in the RFA group, 78% in the chemotherapy group and 93% in the chemotherapy with RFA group (P < 0.001). Increased progression‐free survival (PFS) and overall survival (OS) were observed in the chemotherapy with RFA group (P < 0.001). Cox multivariate analysis indicated that the number of liver metastases (1 vs. >1), the dimension of the largest liver metastases (≤3 cm vs. >3 cm), evaluation of treatment (response vs. no response) and disease‐free survival (≤12 months vs. >12 months) were independent prognostic factors.

Conclusions

RFA combined with chemotherapy is a promising treatment for NPC metastatic liver disease with improved local response, PFS, and OS compared to current chemotherapy protocols. J. Surg. Oncol. 2012; 106:322–326. © 2012 Wiley Periodicals, Inc.
Pulmonary function in individuals who underwent liver transplantation: From the US cystic fibrosis foundation registry
Authors: Miller Melissa R. , Sokol Ronald J. , Narkewicz Michael R. , Sontag Marci K.
Published: January 2012

Severe liver disease affects 4.5% to 10% of individuals with cystic fibrosis (CF) and is the third-leading cause of death. Liver transplantation (LT) is an accepted therapy, but the effects of liver disease and LT on pulmonary function in patients with CF are controversial. Our aim was to characterize changes in pulmonary function in LT patients with CF. Using mixed effect models, we analyzed pulmonary function before and after transplantation in 168 LT patients and 840 non-LT patients with CF who were matched by age, sex, pancreatic status, infections with US CF Foundation Patient Registry data (1989-2007). The primary outcome was the change in the forced expiratory volume in 1 second (FEV1; percent predicted) in LT and non-LT in the 3-years periods before or after transplantation; second we compared FEV1 changes. In the 3 years before transplantation, LT had lower initial FEV1 values (71.5% ± 1.9%, P < 0.001) and a slower decline (+0.1% ± 0.4%/year, P < 0.001) than non-LT (79.6% ± 1.3% and −1.3% ± 0.2%/year, respectively). There was no difference in the FEV1 decline after transplantation (−1.4% ± 0.4%/year for LT versus −2.1% ± 0.2%/year for non-LT, P = 0.14). Both the (P = 0.003) and (P = 0.001) had a slower FEV1 decline in the period before transplantation versus after transplantation. In conclusion, pulmonary function is lower and declines more slowly in patients with CF before LT versus, but parallels the decline in non-LT after transplantation. LT is neither beneficial nor detrimental to pulmonary function in CF but returns FEV1 decline to the same trajectory found for matched non-LT individuals with CF. Liver Transpl, 2012. © 2012 AASLD.
Transient elastography identifies liver recipients with nonviral graft disease after transplantation: A guide for liver biopsy
Authors: Rigamonti Cristina , Fraquelli Mirella , Bastiampillai Anan Judina , Caccamo Lucio , Reggiani Paolo , Rossi Giorgio , Colombo Massimo , Donato Maria Francesca
Published: January 2012

Transient elastography (TE) reliably predicts the severity of recurrent hepatitis C virus after orthotopic liver transplantation (OLT); however, its accuracy in evaluating nonviral liver graft damage is unknown. Between 2006 and 2009, 69 OLT recipients [37 for hepatitis B virus/hepatitis D virus (recurrence-free), 20 for autoimmune/cholestatic liver disease, 6 for alcoholic liver disease, and 6 for mixed etiologies] underwent protocol/on-demand liver biopsy (LB) and concomitant TE. A histological diagnosis of graft disease was made according to criteria defined by the Banff working group. Sixty-five patients (94%) had reliable TE examinations during a median post-OLT follow-up of 18 months (range = 7-251 months). LB samples (median length = 35 mm) showed graft damage in 28 patients (43%): idiopathic chronic hepatitis (11), steatohepatitis (3), rejection (3), cholangitis (2), and autoimmune/cholestatic recurrence (9). Patients with graft damage had significantly higher serum liver enzyme levels and TE results (median = 7.8 kPa, range = 5.4-27.4 kPa) than the 37 patients without graft damage (median = 5.3 kPa, range = 3.1-7.4 kPa, P < 0.001). By a receiver operating characteristic curve analysis, 2 TE cutoffs for the diagnosis of graft damage were identified: 5.3 kPa with 100% sensitivity and 7.4 kPa with 100% specificity. The pretest probability of graft damage was 43%; in patients with TE values ≤5.3 kPa, the posttest probability of graft damage fell to 0%, but in patients with TE results >7.4 kPa, the posttest probability increased to 100%. In conclusion, the dual TE cutoff allows accurate discrimination between the absence and presence of nonviral liver graft damage and improves the clinical management of OLT recipients in terms of the selection of patients most in need of LB. Liver Transpl, 2012. © 2012 AASLD.
Four hundred thirty consecutive pediatric living donor liver transplants: Variables associated with posttransplant patient and graft survival
Authors: Neto Joao Seda , Pugliese Renata , Fonseca Eduardo A. , Vincenzi Rodrigo , Pugliese Vincenzo , Candido Helry , Stein Alberto B. , Benavides Marcel , Ketzer Bernardo , Teng Hsiang , Porta Gilda , Miura Irene K. , Baggio Vera , Guimaraes Teresa , Porta Adriana , Rodrigues Celso Arrais , Carnevale Francisco C. , Carone Eduardo , Kondo Mario , Chapchap Paulo
Published: January 2012

The availability of living donors allows transplant teams to indicate living donor liver transplantation (LDLT) early in the course of liver disease before the occurrence of life-threatening complications. Late referral to transplant centers is still a problem and can compromise the success of the procedure. The aim of this study was to examine the perioperative factors associated with patient and graft survival for 430 consecutive pediatric LDLT procedures at Sirio-Libanes Hospital/A. C. Camargo Hospital (São Paulo, Brazil) between October 1995 and April 2011. The studied pretransplant variables included the following: recipient age and body weight, Pediatric End-Stage Liver Disease score, z score for height/age, bilirubin, albumin, international normalized ratio, hemoglobin, sodium, presence of ascites, and previous surgery. The analyzed technical aspects included the graft-to-recipient weight ratio and the use of vascular grafts for portal vein reconstruction. In addition, the occurrence of hepatic artery thrombosis (HAT), portal vein thrombosis (PVT), and biliary complications was also analyzed. The liver grafts included 348 left lateral segments, 5 monosegments, 51 left lobes, and 9 right lobes. In a univariate analysis, an age < 12 months, a low body weight (≤10 kg), malnutrition, hyperbilirubinemia, and HAT were associated with decreased patient and graft survival after LDLT. In a multivariate analysis, a body weight ≤ 10 kg and HAT were significantly associated with decreased patient and graft survival. The use of vascular grafts significantly increased the occurrence of PVT. In conclusion, a low body weight (≤10 kg) and the occurrence of HAT independently determined worse patient and graft survival in this large cohort of pediatric LDLT patients. Liver Transpl, 2012. © 2012 AASLD.
Increasing disparity in waitlist mortality rates with increased model for end-stage liver disease scores for candidates with hepatocellular carcinoma versus candidates without hepatocellular carcinoma#*
Authors: Goldberg David , French Benjamin , Abt Peter , Feng Sandy , Cameron Andrew M.
Published: January 2012

Candidates with hepatocellular carcinoma (HCC) within the Milan criteria (MC) receive standardized Model for End-Stage LIver Disease (MELD) exception points because of the projected risk of tumor expansion beyond the MC. Exception points at listing are meant to be equivalent to a 15% rusj if 90-day mortality, with additional points granted every 3 months, equivalent to a 10% increased morality risk. We analyzed the United Network for Organ Sharing database (January 1, 2005 to May 31, 2009) to compare the 90-day waitlist outcomes of HCC candidates and non-HCC candidates with similar MELD scores. Two hundred fifty-nine HCC candidates (4.1%) who were initially listed with 22 MELD exception points were removed because of death or clinical deterioration within 90 days of listing, whereas 283 non-HCC candidates (11.0%) with initial laboratory MELD scores of 21 to 23 were removed. Ninety-three HCC candidates (4.6%) with 25 exception points (after 3-6 months of waiting) were removed because of death or clinical deterioration within 90 days, whereas 805 non-HCC candidates (17.3%) with laboratory MELD scores of 24 to 26 were removed. Twenty HCC candidates (3.0%) with 28 exception points (after 6-9 months of waiting) were removed for death or clinical deterioration within 90 days, whereas 646 non-HCC candidates (23.6%) with laboratory MELD scores of 27 to 29 were removed. In multivariate logistic regression models, HCC candidates had significantly lower 90-day odds of waitlist removal for death or clinical deterioration (P < 0.001). Over time, the risk of waitlist removal for death or clinical deterioration was unchanged for HCC candidates (P = 0.17), whereas it increased significantly for non-HCC candidates. The current allotment of HCC exception points should be re-evaluated because of the stable risk of waitlist dropout for these candidates. Liver Transpl 18:434–443, 2012. © 2012 AASLD.
Impact of nighttime and weekend liver transplants on graft and patient outcomes
Authors: Orman Eric S. , Hayashi Paul H. , Dellon Evan S. , Gerber David A. , Barritt Sidney A.
Published: January 2012

Safety concerns have been raised about nighttime and weekend patient care, but it is unknown whether these issues affect liver transplantation. We sought to identify the impact of nighttime and weekend liver transplants on graft and patient survival. We used the United Network for Organ Sharing database to review adult liver transplants from 1987 to 2010. Comparisons were made between nighttime and daytime operations and between weekday and weekend operations. Cox proportional hazard ratios (HRs) were determined 30, 90, and 365 days after transplantation after we controlled for relevant factors; 94,768 transplants were included in the analysis. The patient survival rates at 30, 90, and 365 days for nighttime operations were 96%, 93%, and 86%, respectively. The patient survival rates at 30, 90, and 365 days for weekend operations were 95%, 92%, and 86%, respectively. These rates did not significantly differ from those for daytime and weekday operations, respectively. The graft failure rate was unchanged at 30 and 90 days for weekend transplants but was modestly increased at 365 days [HR = 1.05 (95% confidence interval = 1.01-1.11)]. Graft survival was unaffected by nighttime transplantation. Nighttime and weekend operations for liver transplantation do not affect patient or graft survival, and this testifies to the patient safety measures in place. Liver Transpl, 2012. © 2012 AASLD.
Investigating the Architecture of Segmented and Branched Polymers under Random Scission by Mathematical Modeling
Authors: Iedema Piet D.
Published: January 2012

The “reverse” problem of finding the properties of the linear constituting segments of linear, but segmented chains and of polymer molecules with terminal branch points of a given chain length distribution and number of connectivity or branch points is addressed. An iterative method based on a uniform segmental end point connectivity proves to be successful for both segmented chains and terminal‐branched molecules of arbitrary length distribution. Convergence is achieved using a straightforward back‐substitution scheme. A bivariate chain length/number of branch points distribution is constructed. The method is successfully applied to completely solve the problem of simultaneous random scission of an initially terminal‐branched polymer.

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A QM Approach to the Calculation of Reactivity Ratios in Free‐Radical Copolymerization
Authors: Dossi Marco , Moscatelli Davide
Published: January 2012

All previously published results in the field of predicting copolymer reactivity and composition are collected, along with new, recently determined parameters. The copolymerizations of a variety of monomers, including styrene, acrylates, methacrylates and vinyl acetate, are investigated. In particular, the monomer and radical reactivity ratios for ST/HEMA, ST/GMA, ST/BMA, ST/HEA, MMA/VAc, ST/MMA, and ST/EA are calculated. Good agreement between the computational and experimental results is obtained for comparisons of the determined parameters with the experimental data available in the literature. In addition, some of the computed reactivity ratios are determined in this work for the first time, and they can be used as an initial guess for future experiments.

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Analytical solutions for Euler–Bernoulli beam on visco‐elastic foundation subjected to moving load
Authors: Basu Dipanjan , Kameswara Rao N. S. V.
Published: January 2012

Analytical solutions for the steady‐state response of an infinite beam resting on a visco‐elastic foundation and subjected to a concentrated load moving with a constant velocity are developed in this paper. The beam responses investigated are deflection, bending moment, shear force and contact pressure. The mechanical resistance of the foundation is modeled using two parameters ks and ts — ks accounts for soil resistance due to compressive strains in the soil and ts accounts for the resistance due to shear strains. Since this model represents the ground behavior more accurately than the Winkler spring model, the developed solutions produce beam responses that are closer to reality than those obtained using the existing solutions for Winkler model. The dynamic beam responses depend on the damping present in the system and on the velocity of the moving load. Based on the study, dynamic amplification curves are developed for beam deflection. Such amplification curves for deflection, bending moment, shear force and contact pressure can be developed for any beam‐foundation system and can be used in design. Copyright © 2012 John Wiley & Sons, Ltd.
Micromechanical modeling of mortar as a matrix‐inclusion composite with drying effects
Authors: Chen D. , Shen W. Q. , Shao J. F. , Yurtdas I.
Published: January 2012

A micromechanical analysis is presented for the description of elastic and plastic behavior of a cement‐based material (mortar). The mortar is considered as a composite material constituted with cement paste and sand grain. The mechanical behavior of cement paste is described by an elastoplastic model, while a linear elastic behavior is adopted for sand grains. A non‐linear homogenization approach based on Hill's incremental model is proposed for the determination of macroscopic properties of mortar composite. Further, influences of water saturation degree on mechanical behavior are taken into account by considering capillary effects on plastic deformation of cement paste. Comparisons between numerical simulations and experimental data are presented.

Highlights:

We propose a homogenization method for non‐linear cement‐based materials.

We take into account local properties of constituent phases of composite.

The effects of drying process on effective behavior are considered.

Numerical simulations agree well with experimental data. Copyright © 2012 John Wiley & Sons, Ltd.
What was hot at the ICS meeting Glasgow, Scotland, 2011
Authors: Cartwright Rufus , Mangera Altaf , Tikkinen Kari A.O. , Chapple Christopher
Published: January 2012

In late August 2011 the annual ICS meeting returned to Glasgow, for a week of Scottish themed socializing and scientific debate. In this overview of the scientific programme we have tried to highlight some of the themes of the meeting, looking at new directions for continence basic science, and focusing on abstracts with important implications for clinical practice. Neurourol. Urodynam. 31:2–6, 2012. © 2011 Wiley Periodicals, Inc.
Succinct greedy drawings do not always exist
Authors: Angelini Patrizio , Di Battista Giuseppe , Frati Fabrizio
Published: January 2012

A greedy drawing is a graph drawing containing a distance‐decreasing path for every pair of nodes. A path (v0,v1,…,vm) is distance‐decreasing if d(vi,vm) < d(vi‐1,vm), for i = 1,…,m. Greedy drawings easily support geographic greedy routing. Hence, a natural and practical problem is the one of constructing greedy drawings in the plane using few bits for representing vertex Cartesian coordinates and using the Euclidean distance as a metric. We show that there exist greedy‐drawable graphs that do not admit any greedy drawing in which the Cartesian coordinates have less than a polynomial number of bits. © 2012 Wiley Periodicals, Inc. NETWORKS, 2012
First‐day step‐down to oral outpatient treatment versus continued standard treatment in children with cancer and low‐risk fever in neutropenia. A randomized controlled trial within the multicenter SPOG 2003 FN study
Authors: Brack Eva , Bodmer Nicole , Simon Arne , Leibundgut Kurt , Kühne Thomas , Niggli Felix K. , Ammann Roland A.
Published: January 2012

Background

The standard treatment of fever in chemotherapy‐induced neutropenia (FN) includes emergency hospitalization and empirical intravenous antimicrobial therapy. This study determined if first‐day step‐down to oral outpatient treatment is not inferior to continued standard regarding safety and efficacy in children with low‐risk FN.

Procedure

In a randomized controlled non‐blinded multicenter study, pediatric patients with FN after non‐myeloablative chemotherapy were reassessed after 8–22 hours of inpatient intravenous antimicrobial therapy. Low‐risk patients were randomized to first‐day step‐down to experimental (outpatient, oral amoxicillin plus ciprofloxacin) versus continued standard treatment. Exact non‐inferiority tests were used for safety (no serious medical complication; non‐inferiority margin of difference, 3.5%) and efficacy (resolution of infection without recurrence, no modification of antimicrobial therapy, no adverse event; 10%).

Results

In 93 (26%) of 355 potentially eligible FN episodes low‐risk criteria were fulfilled, and 62 were randomized, 28 to experimental (1 lost to follow‐up) and 34 to standard treatment. In intention‐to‐treat analyses, non‐inferiority was not proven for safety [27 of 27 (100%) vs. 33 of 34 (97%; 1 death) episodes; 95% upper confidence border, 6.7%; P = 0.11], but non‐inferiority was proven for efficacy [23 of 27 (85%) vs. 26 of 34 (76%) episodes; 95% upper confidence border, 9.4%; P = 0.045]. Per‐protocol analyses confirmed these results.

Conclusions

In children with low‐risk FN, the efficacy of first‐day step‐down to oral antimicrobial therapy with amoxicillin and ciprofloxacin in an outpatient setting was non‐inferior to continued hospitalization and intravenous antimicrobial therapy. The safety of this procedure, however, was not assessable with sufficient power. Pediatr Blood Cancer 2012;59:423–430. © 2012 Wiley Periodicals, Inc.
Experience with high dose methotrexate therapy in childhood acute lymphoblastic leukemia in a tertiary care cancer centre of a developing country
Authors: Kapoor Gauri , Sinha Rupal , Abedin Sarfraz
Published: January 2012

Background

Intensification of systemic chemotherapy with inclusion of high dose methotrexate (HDMTX) has helped omit cranial irradiation from standard risk acute lymphoblastic leukemia (ALL) protocols, thereby eliminating the adverse side effects associated with its use. Administration of HDMTX needs meticulous monitoring. Limitations in the availability of trained staff and adequate infrastructure often pose problems in the developing world. The aim of this study was (1) to treat childhood ALL with a protocol that would have reduced use of cranial irradiation and containing infusions of high‐dose methotrexate HDMTX (5 g/m2) without compromising on survival, and (2) evaluate the experience with HDMTX in a tertiary care cancer centre in a developing country.

Methods

A retrospective chart review was done of 41 consecutive children with a confirmed diagnosis of ALL who had received at least one cycle of HDMTX as part of their consolidation treatment with regard to the patient demographic profile, details of HDMTX infusion and leucovorin rescue, toxicity, additional hospitalization, delay in next cycle of chemotherapy and survival.

Results

The clinically most significant toxicities observed were mucositis 39% (58/149) and fever 28% (42/149) together leading to additional hospital stay in 7% (11/149) cycles and neutropenia grade 3 or more in 24.8% (34/137) contributing to delay in next cycle of chemotherapy in 15% (23/149) cycles.

Conclusion

With this strategy, it was possible to omit or reduce the dose of cranial irradiation while maintaining survival outcomes. The administration of HDMTX therapy was found to be feasible and safe with the precautions described. Pediatr Blood Cancer 2012;59:448–453. © 2012 Wiley Periodicals, Inc.
The efficacy and toxicity of SIOP preoperative chemotherapy in Malawian children with a Wilms tumour
Authors: Israels Trijn , Chagaluka George , Pidini Dalida , Caron Huib , de Kraker Jan , Kamiza Steve , Borgstein Eric , Molyneux Liz
Published: January 2012

Background

In Malawi, preoperative chemotherapy for Wilms tumour is a logical strategy, but detailed information on toxicity and efficacy in such a resource limited setting has been unavailable.

Procedure

Patients diagnosed with a unilateral Wilms tumour received preoperative chemotherapy—a two‐drug 4‐week regimen for localized disease and 6 weeks of a three‐drug regimen for metastatic disease. Estimated maximum tumour diameter, decrease in tumour size, resectability, stage distribution and haematological toxicity during therapy were documented.

Results

At diagnosis, 28% of 72 patients had an estimated maximum tumour diameter of more than 25 cm; 29% of patients had metastases. Eight children (11%) died during preoperative chemotherapy. More than half (59%) of the patients developed moderate neutropenia (neutrophils <1.0 × 109/L; CTC grade 3) and 27% severe neutropenia (CTC grade 4 neutrophils <0.5 × 10.9/L). Grade 4 neutropenia occurred significantly more frequently in children receiving the three‐drug regimen compared to the two‐drug regimen; 50% (10/20) versus 15% (6/40) (P = 0.004). Fifty‐seven percent of all patients had CTC grade 4 anaemia (Hb < 6.5 g/dL) during treatment. Most tumours (92%, 56/61) showed a response to chemotherapy but 14% (8/58) remained unresectable.

Conclusion

Preoperative chemotherapy for Wilms tumour causes considerable haematological toxicity and treatment‐related mortality in malnourished Malawian children. A significant number of children have unresectable disease despite preoperative chemotherapy. To reduce treatment related mortality, consideration should be given to starting treatment with reduced doses in acutely malnourished patients. Pediatr Blood Cancer 2012;59:636–641. © 2012 Wiley Periodicals, Inc.
The influence of patient reported outcomes on the discussion of psychosocial issues in children with cancer
Authors: Engelen Vivian , van Zwieten Myra , Koopman Hendrik , Detmar Symone , Caron Huib , Brons Paul , Egeler Maarten , Kaspers Gert‐Jan , Grootenhuis Martha
Published: January 2012

Background

This study investigates the effect of using patient reported outcomes (PROs) about health‐related quality of life (HRQOL) in clinical practice on the type and amount of psychosocial topics discussed during a paediatric oncology consultation.

Procedure

Children (N = 193) with cancer participated in a sequential cohort intervention study, with a control (no PRO was used) and intervention group (a PRO was used). For each child three consecutive consultations with the paediatric oncologist were audio recorded in order to assess the discussed psychosocial topics. One third of the audio recordings were qualitatively analysed.

Results

The type of the discussed psychosocial topics in the control and intervention group did not differ from each other. However, the discussion of psychosocial topics increased in the intervention group compared to the control group. In both groups, topics within the social domain occurred most frequently and topics regarding the emotional domain had the lowest incidence.

Conclusions

PROs do not change the psychosocial content of communication. Paediatric oncologists already address psychosocial issues during the consultation, regardless of the use of a PRO. However, with a PRO available they address these issues more systematically and more often. Pediatr Blood Cancer 2012; 59: 161–166. © 2012 Wiley Periodicals, Inc.
Macrovascular and microvascular outcomes after beginning of insulin versus additional oral glucose‐lowering therapy in people with type 2 diabetes: an observational study
Authors: Hall Gillian C. , McMahon Alex D. , Carroll Dawn , Home Philip D.
Published: January 2012

Purpose

In type 2 diabetes, the optimal stage to introduce insulin can be unclear. We compared the incidence of subsequent vascular disease between treatment regimens, that is, adding another oral glucose‐lowering drug (OGLD) versus starting insulin treatment.

Methods

People with poor control on OGLDs who intensified treatment (2000–2007) were grouped by number of baseline OGLDs. Two composite endpoints, of macrovascular disease (all‐cause mortality, myocardial infarction, acute coronary syndrome and stroke) and of microvascular disease (peripheral neuropathy, nephropathy or retinopathy), together with HbA1c and weight change over a year, were compared in those beginning insulin versus an additional OGLD. All data came from The Health Information Network UK primary care database.

Results

After exclusions, 14 904 people intensified treatment from one OGLD, 7231 from two and 978 from three, 9, 41 and 90%, respectively, started insulin. Average follow‐up was 3.5 years. The adjusted hazard ratios for macrovascular events, OGLD versus insulin, were 0.53 (95%CI 0.42, 0.69) from one baseline treatment, 0.85 (0.70 1.04) from two and 1.07 (0.50, 2.30) from three, with no difference in risk of microvascular disease in any comparison. Mean body weight increased, and mean HbA1c fell across groups; the only significant adjusted comparison was greater weight increase when commencing insulin from one OGLD.

Conclusions

Starting insulin rather than adding another OGLD to double or triple oral therapy did not significantly increase the incidence of vascular events. Beginning insulin from one OGLD was uncommon. More incident macrovascular disease in this group may be caused by residual confounding. Copyright © 2012 John Wiley & Sons, Ltd.
Optimization of picosecond laser structuring for the monolithic serial interconnection of CIS solar cells
Authors: Heise Gerhard , Heiss Andreas , Hellwig Christian , Kuznicki Thomas , Vogt Helmut , Palm Joerg , Huber Heinz P.
Published: January 2012

We report on the optimization of selective picosecond laser structuring for the monolithic serial interconnection of (Cu(In,Ga)(S,Se)2) CIS thin film solar cells. We introduce a quantitative value to compare the energy efficiency of the different investigated laser processes, the specific ablation energy, which indicates the required energy to remove a certain volume of the specific material. We have examined the structuring efficiencies for induced laser ablation processes for a modification of the beam profile (elliptical and flat‐top beam shaping) and for the application of different laser wavelengths (1064 and 532 nm). Application of induced laser processes (often referred as “lift‐off”) decreases the specific ablation energy dramatically by nearly one order of magnitude. Modifications of the beam profile such as elliptical and flat‐top beam shaping are nearly halving the energy per ablated volume relative to a circular beam. The application of a laser wavelength 532 nm decreases the specific ablation energy compared with 1064 nm significantly for processes involving the CIS layer. We finally demonstrate that with a picosecond laser power of only 2 W, the molybdenum back contact (P1, glass side) and the ZnO front contact (P3, ZnO on CIS) can be structured with a process speed of up to 4 m/s. About 2 µm thick CIS layer (P2) is structured by standard direct laser ablation at higher energy densities with 200 mm/s. Copyright © 2012 John Wiley & Sons, Ltd.
Synthesis of amphiphilic poly(N‐vinylcaprolactam) using ATRP protocol and antibacterial study of its silver nanocomposite
Authors: Singh Pooja , Srivastava Ambika , Kumar Rajesh
Published: January 2012

Atom transfer radical polymerization (ATRP) of N‐vinylcaprolactam (NVCL) was studied by uisng ethyl‐2‐bromoisobutyrate (EIB) as initiator in 1,4‐dioxane. It led to controlled radical polymerization of NVCL, with the molecular weight increased along with the conversion of monomer and a relatively narrow molecular weight distribution could be obtained, as determined by gel permeation chromatography. 1H NMR showed that the major population of poly(N‐vinylcaprolactam) (PVCL) retained the chain‐end functional group. The living nature of the ATRP for NVCL was confirmed by the experiments of PVCL chain extension. PVCL was further investigated for its ability to form micelles in aqueous media. Self‐assembling of the amphiphilic PVCL leads to the formation of their micellar aggregates in aqueous media which was confirmed by transmission electron microscope. The critical micelle concentration value was calculated from the photophysical changes of Pyrene‐1‐Carboxaldehyde by UV absorption studies and was found to be 0.0320 mg/mL. The polymer nanocomposite was synthesized and examined in view of antibacterial effect against Enterococcus faecalis, Staphylococcus aureus, Escherichia coli, Proteus mirabilis, and Klebsiella pneumonae. It was found that polymer nanocomposite possess strong antibacterial activity against Enterococcus faecalis with minimum inhibitory concentration value of 32 μg/mL. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Molecular bases for resistance to acetyl‐coenzyme A carboxylase inhibitor in Japanese foxtail (Alopecurus japonicus)
Authors: Tang Huaiwu , Li Jun , Dong Liyao , Dong Aibin , Lü Bo , Zhu Xudong
Published: January 2012

BACKGROUND: Haloxyfop‐R‐methyl is a widely used herbicide to control Poaceae weeds. Alopecurus japonicus, a widespread annual grass, can no longer be controlled by haloxyfop‐R‐methyl after continuous use of this herbicide for several years.

RESULTS: Dose‐response experiments have established that the Js‐R biotype of A. japonicas has evolved resistance to aryloxyphenoxypropionates (APPs). Target‐site enzyme sensitivity experiments have established that the haloxyfop (free acid) rate causing 50% inhibition of acetyl‐CoA carboxylase (ACCase) activity (I50) for the resistant (Js‐R) biotype is 11 times higher than that for the susceptible (Js‐S) biotype. In many cases, resistance to ACCase‐inhibiting herbicides is due to a resistant ACCase enzyme. Full‐length DNA and mRNA sequences of the plastidic ACCase gene were amplified. Eight single‐nucleotide differences were detected in this region. Four of the nucleotide changes were silent mutations. However, the other four nucleotide mutations caused four amino acid substitutions, replacing Arg‐1734 with Gly, Met‐1738 with Leu, Thr‐1739 with Ser and Ile‐2041 with Asn in the R biotype respectively; the substitution at position 2041 had been reported, while the other three had not.

CONCLUSION: The ACCase in the Js‐R biotype was less susceptible to haloxyfop‐R‐methyl than that in the Js‐S biotype. Moreover, the amino acid substitution of Ile‐2041 with Asn might confer resistance to haloxyfop‐R‐methyl in A. japonicas. Copyright © 2012 Society of Chemical Industry