bluuebunny/crossref_metadata_2025 huggingface dataset:
Strong resistance of poly (ethylene glycol) based L‐tyrosine polyurethanes to protein adsorption and cell adhesion
Authors: Yang Jui‐Chen , Zhao Chao , Hsieh I‐Fan , Subramanian Senthilram , Liu Lingyun , Cheng Gang , Li Lingyan , Cheng Stephen Z. D. , Zheng Jie
Published: December 2011

Biofouling that involves protein adsorption, cell and bacteria adhesion, and biofilm formation between a surface and biological entities is a great challenge for biomedical and industry applications. In this work, L‐tyrosine‐derived polyurethanes (L‐polyurethane) with different molecular weights of poly(ethylene glycol) (PEG) were synthesized, characterized and coated on gold surfaces using spin‐coating. The non‐fouling activity of different L‐polyurethane films was evaluated by protein adsorption and cell adhesion. Surface plasmon resonance and cell assay results demonstrate that the PEG content in these L‐polyurethanes contributes excellent resistance to protein adsorption and cell attachments. This work provides alternative and effective biomaterials for potential applications in blood‐contacting devices. Copyright © 2011 Society of Chemical Industry
Thermal properties of poly(dimethyl siloxane) nanocomposite filled with silicon carbide and multiwall carbon nanotubes
Authors: Hong Jinho , Choi Hyun Seok , Lee Kyung Sub , Shim Sang Eun
Published: December 2011

Silicon carbide was incorporated in poly(dimethyl siloxane) (PDMS) in combination with multiwall carbon nanotubes (MWCNTs) to improve the thermal conduction behavior. The amount of silicon carbide was increased from 0 to 150 phr and the amount of MWCNTs was increased from 0 to 8 phr at a fixed amount of silicon carbide (150 phr). The thermal conductivity of the PDMS composite was increased with increasing amount of the MWCNTs and fine dispersibility of the incorporated MWCNTs was achieved without pretreatment. The rheological properties of the PDMS composites incorporating silicon carbide and MWCNTs were investigated and the activation energy of the composites was calculated during thermal decomposition using the Horowitz‐Metzger method. Importantly, unexpected thermal decomposition behavior as indicated by the reduction in activation energy from 361.63 to 194.18 kJ mol−1, namely acceleration of decomposition of the PDMS matrix caused by MWCNTs, was observed for the first time. Copyright © 2011 Society of Chemical Industry
Electronic structure and properties of camphorimine Cu(I) coordination polymers
Authors: Fernandes Tiago A. , Carvalho M. Fernanda N. N. , Galvão Adelino M. , Bandeira Nuno A. G. , Calhorda Maria José , do Rego Ana M. Botelho
Published: December 2011

The first Cu(I) coordination polymer with an aromatic‐substituted camphorimine ligand [(CuCl)(μ‐Cl) (Cu(H2NC6H4NC10H14O)]n was obtained from reaction of CuCl with 3‐(4‐aminophenylimino)‐1,7,7‐trimethylbicyclo[2.2.1]heptan‐2‐one (H2NC6H4NC10H14O). The electronic and the surface properties (studied by X‐ray photoelectron spectroscopy) are consistent with two distinct coordination environments for the copper(I) atoms—tetrahedral and linear—for the polymer family [(CuCl)(μ‐Cl){Cu(YNC10H14O)}]n. DFT band calculations reveal that the highest energy bands are more localized on the copper(I) tetrahedral sites than on the copper(I) linear sites. The redox properties of [(CuCl)(μ‐Cl){Cu(YNC10H14O)}]n [Y = NMe2 (2b), NH2, and H2NC6H4NC10H14O (2a)] studied by cyclic voltammetry show that the oxidation potentials of the two copper centers are in fact indistinguishable. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Hydration and nutrition at the end of life: a systematic review of emotional impact, perceptions, and decision‐making among patients, family, and health care staff
Authors: del Río M. I. , Shand B. , Bonati P. , Palma A. , Maldonado A. , Taboada P. , Nervi F.
Published: December 2011

Background

Decrease in oral intake, weight loss, and muscular weakness in the last phases of a terminal illness, particularly in the context of the cachexia–anorexia syndrome, can be an important source of anxiety for the triad of patient, family, and health staff.

Methods

The present literature review examines the emotional impact of reduced oral intake as well as perceptions and attitudes toward assisted nutrition and hydration for terminally ill patients1 at the end of life, among patients, family, and health care staff. We have identified the ways in which emotional and cultural factors influence decision‐making about assisted nutrition and hydration.

Results

Lack of information and misperceptions of medically assisted nutrition and hydration can play a predominant role in the decision to begin or suspend nutritional or hydration support.

Conclusions

Our literature review reveals that these social, emotional, and clinical misperception elements should be considered in the decision‐making processes to help the triad develop functional forms of care at this final stage of life. Copyright © 2011 John Wiley & Sons, Ltd.
Regional differences in the evolution of lung disease in children with cystic fibrosis
Authors: Li Zhanhai , Sanders Don B. , Rock Michael J. , Kosorok Michael R. , Collins Jannette , Green Christopher G. , Brody Alan S. , Farrell Philip M.
Published: December 2011

Progression of lung disease is a major event in children with cystic fibrosis (CF), but regional differences in its evolution are unclear. We hypothesized that regional differences occur beginning in early childhood. We examined this issue by evaluating 132 patients followed in the Wisconsin Neonatal Screening Project between 1985 and 2010. We scored chest X‐rays obtained every 1–2 years with the Wisconsin chest X‐ray system, in which we divided the lungs into quadrants, and gave special attention to ratings for bronchiectasis (BX) and nodular/branching opacities. We compared the upper and lower quadrant scores, and upper right and left quadrant scores, as patients aged using a multivariable generalized estimation equation (GEE) model. We did a confirmatory analysis for a subset of 81 patients with chest computerized tomography (CT) images obtained in 2000 and scored using the Brody scoring system. The chest X‐ray analysis shows that the upper quadrants have higher BX (P < 0.001) and nodular/branching opacities (P < 0.001) scores than the lower quadrants. CT analysis likewise reveals that the upper quadrants have more BX (P = 0.02). Patients positive for mucoid PA showed significantly higher BX scores than patients with non‐mucoid PA (P = 0.001). Chest X‐ray scoring also revealed that the upper right quadrant has more BX (P < 0.001) than the upper left quadrant, and CT analysis was again confirmatory (P < 0.001). We conclude that pediatric patients with CF develop more severe lung disease in the upper lobes than the lower lobes in association with mucoid PA infections and also have more severe lung disease on the right side than on the left side in the upper quadrants. A variety of potential explanations such as aspiration episodes may be clinically relevant and provide insights regarding therapies. Pediatr Pulmonol. 2012; 47:635–640. © 2011 Wiley Periodicals, Inc.
The Relationship of Lower Limb Muscle Strength and Knee Joint Hyperextension during the Stance Phase of Gait in Hemiparetic Stroke Patients
Authors: Cooper Allison , Alghamdi Ghalib Abdulllah , Alghamdi Mohammed Abdulrahman , Altowaijri Abdulrahman , Richardson Susan
Published: December 2011

Background and Purpose

Despite the finding that 40% to 60% of stroke patients suffer from knee joint hyperextension during gait, there is a lack of agreement of the possible causes of this problem. The aim of this study was to determine whether there is a relationship between lower limb muscle weakness and knee joint hyperextension in hemiparetic stroke patients.

Methods

This is a cross‐sectional observational comparison study. Twenty patients (mean age 66 years) who had suffered a single hemiparetic stroke and were ambulant with no major lower limb joint pathology participated. Muscle strength of the hip extensors, hip flexors, hip abductors, knee extensors, knee flexors, ankle plantarflexors and ankle dorsiflexors of both limbs was measured using a hand‐held dynamometer. Computerized and visual gait analysis identified subjects with and without knee hyperextension in loading response and midstance. Subjects were categorized as having weakness of a particular muscle group if the difference in strength between the paretic and non‐paretic muscle was greater than 50%. The Pearson's chi‐squared test was used to evaluate the association between weakness and knee hyperextension.

Results

A strong relationship was found between ankle plantarflexor weakness and knee hyperextension during midstance (p = 0.044). No relationship was found between lower limb muscle weakness and knee hyperextension during loading response (p > 0.05). No relationship was found between any other lower limb muscle groups and knee hyperextension in midstance (p > 0.05).

Conclusions

Weak ankle plantarflexors, in particular gastrocnemius, may have an important role in the presence of knee hyperextension. The results of this study did not support a role for weak hamstrings or quadriceps in knee hyperextension during gait. Further research is needed to clarify the role of gastrocnemius during the stance phase and to determine if strengthening weak gastrocnemius reduces knee hyperextension. Copyright © 2011 John Wiley & Sons, Ltd.
Phenethyl isothiocyanate suppresses inhibitor of apoptosis family protein expression in prostate cancer cells in culture and in vivo
Authors: Sakao Kozue , Desineni Sudhakar , Hahm Eun‐Ryeong , Singh Shivendra V.
Published: December 2011

BACKGROUND

Cruciferous vegetable constituent phenethyl isothiocyanate (PEITC) causes apoptosis in prostate cancer cells through mechanisms not fully understood. The present study was designed to determine the role of inhibitor of apoptosis (IAP) family proteins in PEITC‐induced apoptosis induction.

METHODS

Effect of PEITC treatment on protein and mRNA expression of IAP in cells was determined by Western blotting and reverse transcription PCR, respectively. Immunohistochemistry was performed to determine the in vivo effect of PEITC administration on X‐linked IAP (XIAP) and Survivin protein expression. Overexpression of desired protein was achieved by transient transfection. Cell viability was determined by trypan blue dye exclusion assay, whereas apoptosis was quantified by measurement of histone‐associated DNA fragment release into the cytosol. Transwell chamber assay was used to determine cell migration.

RESULTS

Exposure of PC‐3 and LNCaP human prostate cancer cells to PEITC resulted in downregulation of XIAP and Survivin proteins and Survivin mRNA. PEITC administration to transgenic adenocarcinoma of mouse prostate mice caused modest but significant downregulation of XIAP and Survivin proteins in the dorsolateral prostate. Proapoptotic response to PEITC was significantly attenuated by ectopic expression of XIAP and Survivin proteins. Survivin overexpression also conferred modest but significant protection against PEITC‐mediated inhibition of PC‐3 cell migration.

CONCLUSIONS

The present study demonstrates that cellular responses to PEITC, including apoptosis induction and inhibition of cell migration, in prostate cancer cells are mediated by downregulation of XIAP and/or Survivin, which may serve as valid biomarkers of PEITC response in future clinical investigations. Prostate 72:1104–1116, 2012. © 2011 Wiley Periodicals, Inc.
Discrepancy in prostate cancer localization between biopsy and prostatectomy specimens in patients with unilateral positive biopsy: Implications for focal therapy
Authors: Sinnott Michael , Falzarano Sara M. , Hernandez Adrian V. , Jones J. Stephen , Klein Eric A. , Zhou Ming , Magi‐Galluzzi Cristina
Published: December 2011

BACKGROUND

Unilateral ablative strategy success depends on reliable prediction of prostate cancer (PCA) location. We evaluated the discrepancy in PCA localization between unilateral positive biopsy (PBx) and radical prostatectomy (RP).

METHODS

Between 2004 and 2008, 431 patients were diagnosed with unilateral PCA by 12‐core PBx; 179 underwent RP and constituted our study cohort. Specimens were reviewed to map tumor outline and determine number of cancer foci, tumor volume, Gleason score (GS), zone of origin, localization, and pathologic stage.

RESULTS

In 50 men, biopsy and prostatectomy findings correlated (unilateral tumor); in 129, PCA was detected in the contralateral side of the prostate. In 52 patients, 54 clinically significant tumors were missed by biopsy. When patients with true unilateral and missed contralateral disease at RP were compared with respect to prognostic parameters no significant differences were detected. Sixty‐one of the 88 patients with preoperative low‐risk disease had true unilateral (n = 21) or missed insignificant contralateral (n = 40) PCA; 27 had missed significant contralateral PCA at RP. PSA > 4 ng/ml predicted presence of significant bilateral disease in low‐risk population (P = 0.004). Twenty‐four of 27 patients with significant bilateral cancer had PSA > 4, although 33/61 with unilateral or bilateral insignificant cancer had similar elevated PSA values.

CONCLUSIONS

Twelve‐core biopsy is inadequate to identify candidates for organ‐sparing therapy. Most men with unilateral positive biopsies have bilateral cancer at prostatectomy. Tumors missed by biopsy were clinically significant in 40% of patients, but no prognostic parameters could predict unilateral disease. Hemi‐ablative treatment might fail to eradicate significant lesions in the contralateral side. Prostate 72:1179–1186, 2012. © 2011 Wiley Periodicals, Inc.
The influence of underlying layer on morphology of InGaN quantum dots self‐assembled by metal organic vapor phase epitaxy
Authors: Wang Lai , Zhao Wei , Lv Wenbin , Wang Lei , Hao Zhibiao , Luo Yi
Published: December 2011

The influences of two different underlying layers of GaN on the growth of InGaN quantum dots self‐assembled by metal organic vapor phase epitaxy are studied. One is a 2 μm high‐temperature grown GaN/sapphire template, and the other includes a 15 nm GaN layer on the template which possesses the same growth temperature with InGaN. The results show the latter can reduce the dot diameter greatly, and hence increase the aspect ratio of quantum dots to about 0.5. This morphology improvement is considered related to the strain area reduction at certain locations when InGaN is deposited on low‐temperature grown GaN. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Highly‐uniform 260 nm‐band AlGaN‐based deep‐ultraviolet light‐emitting diodes developed by 2‐inch×3 MOVPE system
Authors: Mino Takuya , Hirayama Hideki , Takano Takayoshi , Noguchi Norimichi , Tsubaki Kenji
Published: December 2011

High‐efficiency and high‐power deep‐ultraviolet (DUV) light‐emitting diodes (LEDs) with emission wavelength between 200 and 350 nm have a wide range of potential applications. We have developed highly‐uniform 260 nm‐band AlGaN DUV LEDs fabricated on AlN templates on (0001) sapphire using a 2‐inch×3 reactor by low‐pressure metalorganic vapor phase epitaxy (LP‐MOVPE), for the purpose of realizing commercially‐available low‐cost DUV LEDs. An NH3 pulsed‐flow multilayer (ML) growth method was used for the fabrication of low threading dislocation density (TDD) AlN templates on sapphire substrates. 4 μm‐thick low TDD AlN templates were successfully grown on (0001) sapphire substrates. Abnormal hillocks due to polarity inversion were markedly decreased, when the growth temperature of the first NH3 pulsed‐flow AlN layer directly grown on sapphire was reduced to be 1100 ºC. DUV LEDs on the high quality AlN templates showed good uniformity in the emission wavelength and in the output power, in each 2‐inch wafer and among three wafers which were simultaneously grown. The DUV‐LEDs were flip‐chip bonded and demonstrated output power of 17.1 mW at 500 mA and 40 mW at 1500 mA measured under CW and pulsed operations, respectively. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
In vitro Anti‐Herpes Simplex Virus Activity of 1,2,4,6‐Tetra‐O‐galloyl‐β‐d‐glucose from Phyllanthus emblica L. (Euphorbiaceae)
Authors: Xiang Yangfei , Pei Ying , Qu Chang , Lai Zhicai , Ren Zhe , Yang Ke , Xiong Sheng , Zhang Yingjun , Yang Chongren , Wang Dong , Liu Qing , Kitazato Kaio , Wang Yifei
Published: December 2011

In this study, 1,2,4,6‐tetra‐O‐galloyl‐β‐d‐glucose (1246TGG), a polyphenolic compound isolated from traditional Chinese medicine Phyllanthus emblica L. (Euphorbiaceae), was found to inhibit herpes simplex virus type 1 (HSV‐1) and type 2 (HSV‐2) infection at different magnitudes of activity in vitro. Further studies revealed that 1246TGG directly inactivated HSV‐1 particles, leading to the failure of early infection, including viral attachment and penetration. 1246TGG also suppressed the intracellular growth of HSV‐1 within a long period post‐infection (from 0 h p.i. to 12 h p.i.), while it might exert an antiviral effect mainly before 3 h p.i. It inhibited HSV‐1 E and L gene expressions as well as viral DNA replication but did not affect the RNA synthesis of IE gene in our study. Also, in the presence of 1246TGG, the synthesis of viral protein was reduced. Taken together, it was suggested that 1246TGG might exert anti‐HSV activity both by inactivating extracellular viral particles and by inhibiting viral biosynthesis in host cells. These results warrant further studies on the antiviral mechanisms of 1246TGG and suggest that it might be a candidate for HSV therapy. Copyright © 2011 John Wiley & Sons, Ltd.
Antinociceptive Activity of Aerial Parts of Polygonatum verticillatum: Attenuation of Both Peripheral and Central Pain Mediators
Authors: Khan Haroon , Saeed Muhammad , Gilani Anwar ul Hassan , Khan Murad Ali , Khan Inamullah , Ashraf Nadeem
Published: December 2011

Polygonatum verticillatum All. is used traditionally as an analgesic and plant diuretic. The methanol extract of aerial parts of Polygonatum verticillatum (PA) was assessed in various experimental paradigms. The pain threshold in the form of abdominal constriction induced by acetic acid was significantly (p < 0.01) inhibited by PA at test doses (50, 100 and 200 mg/kg). In the formalin test, PA elicited a significant (p < 0.01) analgesic activity in both phases and strongly attenuated the formalin‐induced flinching behaviour. The hot plate test was used to evaluate central involvement in the analgesic profile of PA. The PA significantly relieved thermal‐induced pain. From a mechanistic point of view, the central antihyperalgesic activity was tested for antagonism with naloxone, but no antagonism was observed. The current investigations suggest that the active constituent(s) in PA has an analgesic profile with predominant peripheral activity which is augmented by an opioid independent central effect. In the diuretic assay, PA (300 and 600 mg/kg) showed mild insignificant diuretic activity. Our study rationalized the traditional use of Polygonatum verticillatum in the treatment of painful conditions. Copyright © 2011 John Wiley & Sons, Ltd.
What is the Role of Unripe Rubus coreanus Extract on Penile Erection?
Authors: Zhao Chen , Kim Hye Kyung , Kim Sung Zoo , Chae Han Jung , Cui Wan Shou , Lee Sung Won , Jeon Ju Hong , Park Jong Kwan
Published: December 2011

The effect of unripe Rubus coreanus extract on rabbit penile corpus cavernosum (PCC) was evaluated. Penises were obtained from healthy male New Zealand white rabbits (2.5–3.0 kg). The pre‐contracted penis with phenylephrine (Phe, 10 μm) was treated with various concentrations of an extract of unripe R. coreanus (0.5, 1, 2, 3 and 4 mg/mL). The change in penile tension was recorded, cyclic nucleotides in the perfusate and the PCC were measured by radioimmunoassay, and the expression of neuronal nitric oxide synthase (nNOS) and endothelial nitric oxide synthase (eNOS) in the perfused PCC were measured by western blotting. The interaction between unripe R. coreanus and sildenafil was also evaluated. The PCC relaxation induced by the extracts of R. coreanus was in a concentration‐dependent manner and enhanced sildenafil‐induced PCC relaxation. The perfusion of penile cavernous tissue with the unripe R. coreanus extract increased cGMP and cAMP in the tissue and in the perfusate and the expression of eNOS and nNOS in the tissue. The unripe R. coreanus extract exerts a relaxing effect on penile cavernous tissue in part by activating the NO‐cGMP system and it may improve erectile dysfunction (ED), which does not completely respond to sildenafil citrate. Copyright © 2011 John Wiley & Sons, Ltd.
δ13C and δ15N values in scales of Micropterus salmoides largemouth bass as a freshwater environmental indicator
Authors: Inamura O. , Zhang J. , Minagawa M.
Published: December 2011

We have investigated the effectiveness of using the Micropterus salmoides largemouth bass, which is a top predator found throughout the world, as the index of a hydrosphere environment and its food chain. To this end, we used stable carbon and nitrogen isotope analysis (SIA). Largemouth bass were collected from eight dam reservoirs and two ponds in Toyama Prefecture, Japan. Toyama is located in central Japan and features a variety of distinct geographical environments, a result of the 3000‐m elevation that changes over short distances, and abundant water systems. The mean δ13C and δ15N values for the lipid‐extracted muscle of largemouth bass from all sampling locations showed large variability, but there were only small standard deviations at each sampling location. The isotope ratios for largemouth bass express the characteristics of each investigated hydrosphere environment and food chain. A very high correlation (δ13C: Yscale = 0.96 Xmuscle + 1.58, R2 = 0.98, δ15N: Yscale = 0.92 Xmuscle – 1.15, R2 = 0.95) of SIA values was found between largemouth bass scales and lipid‐extracted muscles, which suggests that the more easily analyzed scales are useful as SIA samples for the monitoring and comparison of hydrosphere environments throughout the world. Copyright © 2011 John Wiley & Sons, Ltd.
Robotics as a new surgical minimally invasive approach to treatment of endometriosis: a systematic review
Authors: Carvalho Luiz , Abrão Mauricio Simões , Deshpande Abhishek , Falcone Tommaso
Published: December 2011

Background

This systematic review evaluates the role of robotics in the surgical treatment of endometriosis.

Methods

Electronic database searches were conducted in MEDLINE, Scopus, and ISI Web of Knowledge for relevant studies over the past 10 years.

Results

Four published articles were found that used robotic assisted laparoscopy to perform endometriosis surgery. All four studies used the da Vinci Surgical System (Intuitive Surgical Inc., Sunnyvale, CA, USA). Three studies were case reports, and one was a cohort study. Robotics appears to be as effective as conventional laparoscopy in the management of endometriosis. There were no reports of any major complications.

Conclusions

Few studies have been published and show us that robotic endometriosis surgery is feasible even in severe endometriosis cases without conversion. There is a lack of long‐term outcome papers in the literature. Randomized controlled trials are necessary. Copyright © 2011 John Wiley & Sons, Ltd.
New class‐dependent feature transformation for intrusion detection systems
Authors: Mohammadi Mehdi , Raahemi Bijan , Akbari Ahmad , Nassersharif Babak
Published: December 2011

Intrusion Detection Systems (IDS) mainly focus on the original features extracted from the communications networks without complex pre‐processing. In this paper, we propose new methods for class‐dependent feature transformation to improve the accuracy of the IDS. In the previously known class‐dependent feature transformation methods, the mapping process is accomplished by employing separate mapping matrices for each class of the dataset. In the training phase, samples of each class is mapped using only the corresponding matrix, whereas, in the test phase, each sample is mapped using all transformation matrices. This may lead to inaccuracy in classification. We modify the training and test phases of the class‐dependent methods to extract more information from the dataset in the training phase that the other class‐dependent methods ignore. Unlike the previously known class‐dependent methods, the training and test phases of our proposed methods are very similar. We evaluate the performance of the proposed methods by measuring Mutual Information, and Maximum‐Relevancy Minimum‐Redundancy Information on a benchmark dataset for intrusion detection, namely NSL‐KDD dataset, and on three different types of classifiers: distance‐based, neural network‐based, and decision tree‐based classifiers. The experimental results demonstrate that the classifiers trained on the dataset transformed by our proposed feature transformation methods are more accurate in detecting intruders. In all experiments, the proposed methods perform better than their peers in increasing the classifier accuracy and reducing the false alarm of the detection process. Copyright © 2011 John Wiley & Sons, Ltd.
Estimation and testing of the relative risk of disease in case‐control studies with a set of k matched controls per case with known prevalence of disease
Authors: Moser Barry Kurt , Halabi Susan
Published: December 2011

The analysis of case‐control studies with matched controls per case is well documented in the medical literature. Of primary interest is the estimation of the relative risk of disease. Matched case‐control studies fall into two scenarios: the probability of exposure is constant within each of the case and control groups, or the probability of exposure varies within each group. Numerous estimation procedures have been developed for both scenarios. Often these procedures are developed under the rare disease assumption, where the relative risk of disease is approximated by the odds ratio. In this paper, without making the rare disease assumption, we develop consistent estimators of the relative risk of disease for both scenarios. Exact derivations of the relative risk of disease are provided. Estimators, confidence intervals, and test statistics for the relative risk of disease are developed. We then make the following observations based on extensive simulations. First, our estimators are as close or closer to the relative risk of disease than other estimators. Second, our estimators produce mean square errors for the relative risk of disease that are as good as or better than these other estimators. Third, our confidence intervals provide accurate coverage probabilities. Therefore, these new estimators, confidence intervals, and test statistics can be used to either estimate or test the relative risk of disease in matched case‐control studies. Copyright © 2011 John Wiley & Sons, Ltd.
Program impact evaluation using a matching method with panel data
Authors: Nguyen Viet Cuong
Published: December 2011

Difference‐in‐differences with matching is a popular method to measure the impact of an intervention in health and social sciences. This method requires baseline data, that is, data before interventions, which are not always available in reality. Instead, panel data with two time periods are often collected after interventions begin. In this paper, a simple matching method is proposed to measure the impact of an intervention using two‐period panel data after the intervention. The method is illustrated by the measurement of the effect of health insurance in Vietnam using household panel data. Copyright © 2011 John Wiley & Sons, Ltd.
Physical Aspects of Cell Culture Substrates: Topography, Roughness, and Elasticity
Authors: Ross Aftin M. , Jiang Zhongxiang , Bastmeyer Martin , Lahann Joerg
Published: December 2011

The cellular environment impacts a myriad of cellular functions by providing signals that can modulate cell phenotype and function. Physical cues such as topography, roughness, gradients, and elasticity are of particular importance. Thus, synthetic substrates can be potentially useful tools for exploring the influence of the aforementioned physical properties on cellular function. Many micro‐ and nanofabrication processes have been employed to control substrate characteristics in both 2D and 3D environments. This review highlights strategies for modulating the physical properties of surfaces, the influence of these changes on cell responses, and the promise and limitations of these surfaces in in‐vitro settings. While both hard and soft materials are discussed, emphasis is placed on soft substrates. Moreover, methods for creating synthetic substrates for cell studies, substrate properties, and impact of substrate properties on cell behavior are the main focus of this review.
Application of performance‐based design to an eccentrically braced frame structure
Authors: Sabol T. A. , Nishi D. E.
Published: December 2011

This paper focuses on the application of performance‐based design to a tall eccentrically braced frame (EBF) structure. The height of the structure exceeds that permitted by theInternational Building Codefor braced frames, and a dual system would typically be required. It was argued that better, more cost‐effective seismic performance could be obtained using an all‐braced frame scheme. Project‐specific performance and analysis criteria were developed limiting overall story drift and link rotation demand. EBF link models used recently completed research to calibrate behavior, particularly that associated with estimating link overstrength in thick‐flanged link beams. Key findings include more realistic column axial load demands than would have been predicted using current AISC 341Seismic Provisionsas well as improved EBF strength distribution throughout the height of the building to delay formation of story mechanisms. Copyright © 2011 John Wiley & Sons, Ltd.
Wind turbine SCADA alarm analysis for improving reliability
Authors: Qiu Yingning , Feng Yanhui , Tavner Peter , Richardson Paul , Erdos Gabor , Chen Bindi
Published: December 2011

Previous research for detecting incipient wind turbine failures, using condition monitoring algorithms, concentrated on wind turbine Supervisory Control and Data Acquisition (SCADA) signals, such as power output, wind speed and bearing temperatures, using power‐curve and temperature relationships. However, very little research effort has been made on wind turbine SCADA alarms. When wind turbines are operating in significantly sized wind farms, these alarm triggers are overwhelming for operators or maintainers alike because of large number occurring in a 10 min SCADA period. This paper considers these alarms originating in two large populations of modern onshore wind turbines over a period of 1–2 years. First, an analysis is made on where the alarms originate. Second, a methodology for prioritizing the alarms is adopted from an oil and gas industry standard to show the seriousness of the alarm data volume. Third, two methods of alarm analysis, time‐sequence and probability‐based, are proposed and demonstrated on the data from one of the wind turbine populations, considering pitch and converter systems with known faults. The results of this work show that alarm data require relatively little storage yet provide rich condition monitoring information. Both the time‐sequence and probability‐based analysis methods have the potential to rationalize and reduce alarm data, providing valuable fault detection, diagnosis and prognosis from the conditions under which the alarms are generated. These methods should be developed and integrated into an intelligent alarm handling system for wind farms, aimed at improving wind turbine reliability to reduce downtime, increase availability and leading to a well‐organized maintenance schedule. Copyright © 2011 John Wiley & Sons, Ltd.
Algorithms for hierarchical clustering: an overview
Authors: Murtagh Fionn , Contreras Pedro
Published: December 2011

We survey agglomerative hierarchical clustering algorithms and discuss efficient implementations that are available in R and other software environments. We look at hierarchical self‐organizing maps, and mixture models. We review grid‐based clustering, focusing on hierarchical density‐based approaches. Finally, we describe a recently developed very efficient (linear time) hierarchical clustering algorithm, which can also be viewed as a hierarchical grid‐based algorithm. © 2011 Wiley Periodicals, Inc.

This article is categorized under:

Algorithmic Development > Hierarchies and Trees

Technologies > Structure Discovery and Clustering
Nanobiotechnology for the capture and manipulation of circulating tumor cells
Authors: Hughes Andrew D. , King Michael R.
Published: December 2011

A necessary step in metastasis is the dissemination of malignant cells into the bloodstream, where cancer cells travel throughout the body as circulating tumor cells (CTC) in search of an opportunity to seed a secondary tumor. CTC represent a valuable diagnostic tool: evidence indicates that the quantity of CTC in the blood has been shown to relate to the severity of the illness, and samples are readily obtained through routine blood draws. As such, there has been a push toward developing technologies to reliably detect CTC using a variety of molecular and immunocytochemical techniques. In addition to their use in diagnostics, CTC detection systems that isolate CTC in such a way that the cells remain viable will allow for the performance of live‐cell assays to facilitate the development of personalized cancer therapies. Moreover, techniques for the direct manipulation of CTC in circulation have been developed, intending to block metastasis in situ. We review a number of current and emerging micro‐ and nanobiotechnology approaches for the detection, capture, and manipulation of rare CTC aimed at advancing cancer treatment. WIREs Nanomed Nanobiotechnol 2012, 4:291–309. doi: 10.1002/wnan.168

This article is categorized under:

Nanotechnology Approaches to Biology > Cells at the Nanoscale

Implantable Materials and Surgical Technologies > Nanomaterials and Implants

Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease
The molecular characterization of new types of Saccharomyces cerevisiae × S. kudriavzevii hybrid yeasts unveils a high genetic diversity
Authors: Peris David , Belloch Carmela , Lopandić Ksenija , Álvarez‐Pérez José Manuel , Querol Amparo , Barrio Eladio
Published: December 2011

New double‐ and triple‐hybrid Saccharomyces yeasts were characterized using PCR‐restriction fragment length polymorphism of 35 nuclear genes, located on different chromosome arms, and the sequencing of one nuclear and one mitochondrial gene. Most of these new hybrids were originally isolated from fermentations; however, two of them correspond to clinical and dietary supplement isolates. This is the first time that the presence of double‐hybrid S. cerevisiae × S. kudriavzevii in non‐fermentative substrates has been reported and investigated. Phylogenetic analysis of the MET6 nuclear gene confirmed the double or triple parental origin of the new hybrids. Restriction analysis of gene regions in these hybrids revealed a high diversity of genome types. From these molecular characterizations, a reduction of the S. kudriavzevii fraction of the hybrid genomes is observed in most hybrids. Mitochondrial inheritance in hybrids was deduced from the analysis of mitochondrial COX2 gene sequences, which showed that most hybrids received the mitochondrial genome from the S. kudriavzevii parent. However, two strains inherited a S. cerevisiae COX2, being the first report of S. cerevisiae × S. kudriavzevii hybrids with S. cerevisiae mitochondrial genomes. These two strains are those showing a higher S. kudriavzevii nuclear genome reduction, especially in the wine hybrid AMH. This may be due to the release of selective pressures acting on the other hybrids to maintain kudriavzevii mitochondria‐interacting genes. Copyright © 2011 John Wiley & Sons, Ltd.
The Effectiveness of Cultural Adjustment and Trauma Services (CATS): Generating Practice‐Based Evidence on a Comprehensive, School‐Based Mental Health Intervention for Immigrant Youth
Authors: Beehler Sarah , Birman Dina , Campbell Ruth
Published: December 2011

A collaborative study of Cultural Adjustment and Trauma Services (CATS), a comprehensive, school‐based mental health program for traumatized immigrant children and adolescents, was conducted to generate practice‐based evidence on the service delivery model across two school districts. Program effectiveness was assessed by testing whether client functioning and PTSD symptoms improved as a result of 7 separate service elements. An array of clinical services including CBT, supportive therapy, and coordinating services were provided to all students, and an evidence‐based intervention for trauma, TF‐CBT, was implemented with a subset of students. Greater quantities of CBT and supportive therapy increased functioning, while greater quantities of coordinating services decreased symptoms of PTSD. TF‐CBT services were associated with both improved functioning and PTSD symptoms, although TF‐CBT was implemented with fidelity to the overall comprehensive service model rather than the structured intervention model. Results suggest the comprehensive school‐based model was effective, though different service components affected different student outcomes. Implications of these findings for immigrant mental health interventions and implementing structured evidence‐based practices into community mental health programs are discussed. Suggestions are made for future research on existing mental health practices with immigrants.
Analysis of Changing Residential Fire Dynamics and Its Implications on Firefighter Operational Timeframes
Authors: Kerber Stephen
Published: December 2011

There has been a steady change in the residential fire environment over the past several decades. These changes include larger homes, different home geometries, increased synthetic fuel loads, and changing construction materials. Several experiments were conducted to compare the impact of changing fuel loads in residential houses. These experiments show living room fires have flashover times of less than 5 min when they used to be on the order of 30 min. Other experiments demonstrate the failure time of wall linings, windows and interior doors have decreased over time which also impact fire growth and firefighter tactics. Each of these changes alone may not be significant but the all-encompassing effect of these components on residential fire behavior has changed the incidents that the fire service is responding to. This analysis examines this change in fire dynamics and the impact on firefighter response times and operational timeframes.
Ranking of Urology Registrar Placements within a Region. An SAC Pilot
Authors: Oates J.E. , O'Flynn K.J. , Shackley D.C.
Published: December 2011

Background:

There is a continual desire to improve educational standards, demonstrate quality assurance of training and to respond to the growing pressure to reduce SpR numbers. Any reduction would need to be based on an assessment which looks at educational value and trainee experience. We describe our experience using a tool to rank urology registrar posts in a single region.

Methods and materials:

An assessment scoring tool was created with equal trainee and trainer components. The trainee and trainer elements were developed from the proposed JCST trainee assessment and the GMC standards for trainers, with a maximum score of 200 achievable. Higher scores could be obtained by the unit being pro-active with educational activities. This tool was completed by all the training units and trainees within a single region.

Results:

Results were obtained from all units within the region, with scores ranging from 130 to 168 (mean 149). Units scoring highly in trainee components also scored highly in the trainer component.

Conclusion:

This tool allows objective assessment of training posts using evidence from the training unit, trainee and TPD. Incorporating this data into the annual ARCP would potentially improve the process. There was widespread support for repeating the exercise and the tool provided a powerful means of engagement in improving training.
Burning peat and reworking loess contribute to the formation and evolution of a large Carolina-bay basin
Authors: Rodriguez Antonio B. , Waters Matthew N. , Piehler Michael F.
Published: December 2011

Carolina bays are nearly ubiquitous along ~ 1300 km of the North American Atlantic Coastal Plain, but relatively few bays have been examined in detail, making their formation and evolution a topic of controversy. The Lake Mattamuskeet basin, eastern North Carolina, USA, is a conglomeration of multiple Carolina bays that form a > 162 km2 lake. The eastern shoreline of the lake is made up of a 2.9-km-wide plain of parabolic ridges that recorded rapid shoreface progradation. The lower shoreface deposit contains abundant charcoal beds and laminae dated 6465–6863 cal yr BP, corresponding with initiation of a lacustrine environment in the eastern part of the lake. A core from the western part of the lake sampled a 1541–1633 cal yr BP charcoal bed at the base of the lacustrine unit, indicating formation of this part of the basin postdates the eastern basin. Lake Mattamuskeet has no relationship to the Younger Dryas or a linked impact event because rim accretion significantly postdates 12,000 cal yr BP. The shoreline progradation, and association of charcoal beds with the oldest lake sediment in both main parts of the basin, suggest that fire and subsequent hydrodynamic processes were associated with initial formation of these Carolina bays.
Particular Solution of Polyharmonic Spline Associated with Reissner Plate Problems
Authors: Tsai C. C. , Quadir M. E. , Hwung H. H. , Hsu T. W.
Published: December 2011

In this paper, analytical particular solutions of the augmented polyharmonic spline (APS) associated with Reissner plate model are explicitly derived in order to apply the dual reciprocity method. In the derivations of the particular solutions, a coupled system of three second-ordered partial differential equations (PDEs), which governs problems of Reissner plates, is initially transformed into a single six-ordered PDE by the Hörmander operator decomposition technique. Then the particular solutions of the coupled system can be found by using the particular solution of the six-ordered PDE derived in the first author's previous study. These formulas are further implemented for solving problems of Reissner plates under arbitrary loadings. In the solution procedure, an arbitrary loading measured at some scattered points is first interpolated by the APS and a corresponding particular solution can then be approximated by using the prescribed formulas. After that the complementary homogeneous problem is formally solved by the method of fundamental solutions (MFS). Numerical experiments are carried out to validate these particular solutions.
Endochronic Simulation on the Effect of Curvature Rate at the Preloading Stage on the Subsequent Creep or Relaxation of Thin-Walled Tubes Under Pure Bending
Authors: Chang K.-H. , Hung C.-Y.
Published: December 2011

In this paper, the first-order ordinary differential constitutive equations of endochronic theory were combined with the principle of virtual work for simulating the response of creep (moment is kept constant for a period of time) or relaxation (curvature is kept constant for a period of time) of thin-walled tubes subjected to pure bending with different curvature-rates at the preloading stage. A group of Fourier series was used to describe the circumferential displacements of the tube. Thus, a system of nonlinear algebraic equations was determined. This system of equations can be solved by numerical method. Experimental data tested by Pan and Fan [1] were compared with the theoretical simulations in this study. It is shown that the theoretical formulations effectively simulate the experimental data.
Simulation of Crack Propagation in Three-Point Bending Piezoelectric Beam Based on Three-Dimensional Anisotropic Piezoelectric Damage Mechanics
Authors: Yang X. H. , Cao W. Z. , Tian X. B.
Published: December 2011

A finite element method combined with three-dimensional anisotropic piezoelectric continuum damage mechanics is presented to simulate quasi-static crack propagation behavior in piezoelectric ceramics in this paper. In this method, the three-dimensional anisotropic piezoelectric damage constitutive model is utilized for characterizing the effects of mechanical and electrical damages on the fields near the crack tip, the combined-damage from the dominant mechanical and electrical damage components is regarded as the fracture criterion, and the gradient of combined-damage is assumed to control crack growth direction. A set of numerical simulations of the midspan crack propagation in a three-point bending PZT-4 beam are performed in various loading conditions. After the numerical results are validated by comparison with the corresponding experimental ones, the effects of mechanical and electrical loads on the cracking be havior are respectively evaluated. It is found from the obtained results that mechanical and electrical loads influence on the damage fields in the vicinity of the crack-tip, as well as the crack growth rate, in a significant way. With the increment in mechanical loading, the crack growth rate obviously increases. This means that positive and negative electric fields enhance and inhibit crack propagation, respectively.
Experimental and Numerical Investigation into the Quasi-Static Crushing Behaviour of the S-Shape Square Tubes
Authors: Khalkhali A. , Masoumi A. , Darvizeh A. , Jafari M. , Shiri A.
Published: December 2011

Vehicle energy absorbing components usually have a curved shape to avoid interference with other components like engine, driving system and fuel tank, etc. Crush behaviour of the S-shape square tubes, as a simplified model of front member of a vehicle body, is investigated in the present study. Experimental and numerical investigation into the quasi static crushing of such tubes was performed. Experimental tests were carried out with cross head speed of 5mm/min. Finite element analysis was performed using ABAQUS/Explicit to simulate quasi-static tests conditions. The predicted crushing characteristics such as global deformation mode, plastic folding mode and load-displacement response obtained by numerical approach were found to be in good agreement with the experimental results. The validated numerical model was then used in the parametric study to examine the effect of design parameters such as wall thickness, web width, curve angle and radius of curvature on the energy absorption capability of the S-shape square tubes. It is shown that some interesting relationships can be discovered by the parametric study to be used as useful design approach for improving the performance of the S-shape tubes.
Experimental and Numerical Study on a Straight Exhaust Pipe
Authors: Liang S.-M. , Wang C.-J.
Published: December 2011

In this study, radiated noise is investigated by experimental and numerical methods for a straight exhaust pipe of diameter 23mm that replaces the original exhaust pipe of a motorcycle of EZ 125cc provided by Kwang Yang Motor Co. In experiment, temperature, pressure and flow speed of the exhausted gas have been measured for different engine speeds ranging from 3000-5000rpm without loading. Sound pressure levels (SPL) at a distance of 0.5m from the exhaust pipe exit for different inclination angles (0° ∼ 90°) were recorded and compared with the result of simulation. In numerical simulation, a high-resolution 5th-order Euler solver was used and conducted on a parallel computation system with a cluster of 4 personal computers with dual processors. It is found that the back-and-forth reflection of expansion waves inside the pipe due to the shock wave diffraction around the pipe exit is the mechanism of radiating sound waves from the exhaust pipe. The numerical result shows the exhausted-gas flow with complicated vortex rings and its associated acoustic field. The acoustic field indicates that there are three sound lobes with different directivities for the engine speed of 4000rpm.