bluuebunny/crossref_metadata_2025 huggingface dataset:
Methylene Blue/Multiwall Carbon Nanotube Modified Electrode for the Amperometric Determination of Hydrogen Peroxide
Authors: Peña Roselyn C. , Bertotti Mauro , Brett Christopher M. A.
Published: September 2011

A novel amperometric sensor based on the incorporation of multiwalled carbon nanotubes (MWCNT) into a poly(methylene blue) (PMB) film immobilized on carbon composite electrodes is described. Cyclic voltammetry indicated that at a surface covered by a MWCNT/PMB layer the cathodic reduction of hydrogen peroxide is facilitated and occurs already at 0.0 V versus SCE. The effect of the order of deposition of PMB and MWCNT, as well as its loading, on electrochemical behaviour was evaluated by cyclic voltammetry and electrochemical impedance spectroscopy. The influence of the various immobilised platforms on the electrocatalytic performance towards hydrogen peroxide was also examined.
Size separation of proteins by capillary zone electrophoresis with cationic hitchhiking
Authors: Dolnik Vladislav , Gurske William A.
Published: September 2011

The paper describes a method of size separation of proteins by capillary sieving electrophoresis with cationic surfactant. Proteins are separated within 12 min with repeatability of migration times better than 0.2%. Some proteins achieve the separation efficiency of 200 000 theoretical plates. The method can be used for determination of protein relative molecular masses. The accuracy of the determined relative molecular masses and the limitation of the method were investigated by the analysis of more than 60 proteins. The method also allows separation of protein oligomers. Proteins can be quantitated after the electrokinetic injection in the concentration range 0.07–0.43 g/L. The average detection limit is about 2 mg/L.
Methylmercury and selenium speciation in different tissues of beluga whales (Delphinapterus leucas) from the western Canadian Arctic
Authors: Lemes Marcos , Wang Feiyue , Stern Gary A , Ostertag Sonja K , Chan Hing Man
Published: September 2011

Monitoring data have shown that the total monomethylmercury (CH3Hg+ and its complexes; collectively referred as MeHg hereafter) concentrations in Arctic marine mammals have remained very high in recent decades. Toward a better understanding of the metabolic and toxicological implications of these high levels of MeHg, we report here on the molecular forms of MeHg in the muscle, brain, liver, and kidneys of 10 beluga whales from the western Canadian Arctic. In all tissues analyzed, monomethylmercury was found to be dominated by methylmercuric cysteinate, a specific form of MeHg believed to be able to transport across the blood–brain barrier. Another MeHg–thiol complex, methylmercuric glutathionate, was also detected in the muscle and, to a much lesser extent, in the liver and brain tissues. Furthermore, a profound inorganic Hg peak was detected in the liver and brain tissues, which showed the same retention time as a selenium (Se) peak, suggesting the presence of an Hg–Se complex, most likely an inorganic Hg complex with a selenoamino acid. These results provide the first analytical support that the binding of MeHg with glutathione and Se may have protected beluga whales from the toxic effect of high concentrations of MeHg in their body. Environ. Toxicol. Chem. 2011;30:2732–2738. © 2011 SETAC
Insulation modelling for thermal FEM analysis of PVC and XLPE cables under fault conditions
Authors: Klimenta Dardan , Radosavljević Jordan , Jevtić Miroljub , Raičević Vladimir , Tasić Dragan , Todorović Andreja
Published: September 2011

An approach to modelling of electrical and thermo‐physical properties in small cylindrical volumes of cable insulation, that is, insulation spot samples is presented in this paper. Apart from small leakage currents, high currents can flow through these spots under fault conditions, at the same time heating up and destroying the cable insulation in them as well. An introduction of models for electrical and thermo‐physical properties of the insulation to the nonlinear thermal finite element method (FEM) analysis of faults is demonstrated on the examples of short circuits that occurred in buried power cables. Nonlinearity of the thermal FEM model is based on the heat sources, electrical and thermo‐physical properties of polyvinyl‐chloride and cross‐linked polyethylene insulation as functions of temperature and/or time. According to the DIN VDE standards, the cable structures considered herein correspond to the NAYY 4×120 SM 0.6/1 kV and NA2XY 4×120 SM 0.6/1‐kV cables. The proposed models for insulation properties are applicable to the fault thermal FEM analysis of all multi‐core power cables laid in the soils, air or water. Copyright © 2011 John Wiley & Sons, Ltd.
Lifts for evacuation—human behaviour considerations
Authors: Heyes Emma , Spearpoint Michael
Published: September 2011

To predict the time that a building will take to be evacuated in an emergency and to design lift systems capable of dealing with the demand, building designers need an understanding of the likely exiting behaviour of occupants.

Because of the inherent difficulties of carrying out research in human behaviour, a number of approaches have been used in this investigation, including analysis of data from past fire events and a number of surveys. The results from this work suggest that the split of occupants using the stairs or lifts to evacuate is governed predominantly by floor level of the occupant and that it is unreasonable to expect that occupants will wait indefinitely for a lift to arrive in an emergency situation. The drop‐off in the percentage of occupants that will continue to wait for a lift with increasing waiting time is dependent on floor height.

These results will allow building designers to make more realistic assumptions when designing evacuation strategies incorporating lifts. It is also hoped that a better understanding of the reservations that building users may have about using lifts for evacuation in emergency situations will allow better occupant training programmes to be developed. Copyright © 2011 John Wiley & Sons, Ltd.
Sub‐micrometre coatings as an infrared mirror: A new route to flame retardancy
Authors: Schartel B. , Beck U. , Bahr H. , Hertwig A. , Knoll U. , Weise M.
Published: September 2011

Most of the polymeric materials used are easy to ignite and show extensive flame spread along their surfaces. Apart from extensive heat release rates, their short time to ignition (tig), in particular, is a key fire hazard. Preventing ignition eliminates fire hazards completely. Protection layers that shift tig by more than an order of magnitude are powerful flame retardancy approaches presenting an alternative to the usual flame retardancy concepts.

Coatings are proposed that consist of a three‐layer system to ensure adhesion to the substrate, acting as an infrared (IR) mirror and protecting against oxidation. The IR‐mirror layer stack is realised by physical vapour deposition in the sub‐micrometre (<1 µm) range, reducing heat absorption by up to an order of magnitude. Not only is the ease of ignition diminished (tig is increased by several minutes), the flame spread and fire growth indices are also remarkably reduced to as little as 1/10 of the values of the uncoated polymers open for further optimization. Sub‐micrometre thin IR‐mirror coatings yielding surface absorptivity <0.1 are proposed as a novel and innovative flame retardancy approach. Copyright © 2011 John Wiley & Sons, Ltd.
Self‐perception of aging and acute medical events in chronically institutionalized middle‐aged and older persons with schizophrenia
Authors: Cheng Sheung‐Tak , Yip Leona C. Y. , Jim Olivia T. T. , Hui Anna N. N.
Published: September 2011

Objectives

To examine the relationship between self‐perceptions of aging and acute medical events in chronically institutionalized middle‐aged and older persons with schizophrenia.

Methods

Participants were 83 persons with schizophrenia (30% women; mean age = 58.48, SD = 8.14) residing in a long‐stay care home, who were without organic mental disorders, mental retardation, serious audiovisual impairment, and serious cognitive and physical impairment. They received assessments in body mass index, functional health, and global mental status, and responded to measures of self‐perception of aging at baseline. Acute events that required medical attention were recorded for the next 3 months.

Results

8% of the participants had acute medical events. Bivariate analysis suggested that number of comorbid medical conditions, mobility, Mini‐Mental State Examination, and negative self‐perception of aging were predictive of acute medical events. However, multivariate analysis (logistic regression) showed that only mobility (OR = 0.78, p = 0.04) and negative self‐perception of aging (OR = 3.38, p = 0.02) had independent effects on acute medical events, with the latter being the stronger predictor. Positive aging self‐perception, body mass index, and smoking were unrelated to medical events.

Conclusions

Physical vulnerabilities may not be sufficient to explain the development of acute medical events in late‐life schizophrenia. How individuals perceive their aging process, which is expected to regulate health behavior and help‐seeking, may be an even more important factor. Further research should investigate whether such self‐perceptions, which are probably rooted in stereotypes about aging socialized early in life, are modifiable in this population. Copyright © 2011 John Wiley & Sons, Ltd.
What's the story? The tale of reading fluency told at speed
Authors: Benjamin Christopher F. A. , Gaab Nadine
Published: September 2011

Fluent readers process written text rapidly and accurately, and comprehend what they read. Historically, reading fluency has been modeled as the product of discrete skills such as single word decoding. More recent conceptualizations emphasize that fluent reading is the product of competency in, and the coordination of, multiple cognitive sub‐skills (a multi‐componential view). In this study, we examined how the pattern of activation in core reading regions changes as the ability to read fluently is manipulated through reading speed. We evaluated 13 right‐handed adults with a novel fMRI task assessing fluent sentence reading and lower‐order letter reading at each participant's normal fluent reading speed, as well as constrained (slowed) and accelerated reading speeds. Comparing fluent reading conditions with rest revealed regions including bilateral occipito‐fusiform, left middle temporal, and inferior frontal gyral clusters across reading speeds. The selectivity of these regions' responses to fluent sentence reading was shown by comparison with the letter reading task. Region of interest analyses showed that at constrained and accelerated speeds these regions responded significantly more to fluent sentence reading. Critically, as reading speed increased, activation increased in a single reading‐related region: occipital/fusiform cortex (left > right). These results demonstrate that while brain regions engaged in reading respond selectively during fluent reading, these regions respond differently as the ability to read fluently is manipulated. Implications for our understanding of reading fluency, reading development, and reading disorders are discussed. Hum Brain Mapp, 2012. © 2011 Wiley Periodicals, Inc.
Pharyngoesophageal stricture after treatment for head and neck cancer
Authors: Wang Jing Jing , Goldsmith Tessa A. , Holman Allison S. , Cianchetti Marco , Chan Annie W.
Published: September 2011

Background

The purpose of this study was to report the risk of pharyngoesophageal stricture after treatment for head and neck cancer.

Methods

Human studies on radiation therapy with or without chemotherapy for head and neck cancer published in peer‐reviewed journals with assessment of pharyngoesophageal stricture with barium swallow or endoscopy were included.

Results

A total of 4727 patients from 26 studies treated between 1989 and 2008 were eligible for analysis. The reported overall risk of stricture was 7.2%. The risks of pharyngoesophageal stricture in both conventional and intensity‐modulated radiation therapy (IMRT) studies were 5.7% and 16.7%, respectively (p < .001). Use of concurrent (p < .001) and taxane (p = .01) chemotherapy was associated with the IMRT technique. Prospective studies reported a 3.3‐fold increased risk of stricture compared with that of retrospective studies (odds ratio: 3.3; 95% confidence interval: 2.3–4.8; p < .001).

Conclusions

Pharyngoesophageal stricture after IMRT and chemotherapy treatment for head and neck cancer is not uncommon. Videofluoroscopic swallow study should be performed prospectively to evaluate swallowing function. © 2011 Wiley Periodicals, Inc. Head Neck, 2012
Perspective of physicians within a multidisciplinary team: Content validation of the comprehensive ICF core set for head and neck cancer
Authors: Leib Andreas , Cieza Alarcos , Tschiesner Uta
Published: September 2011

Background

The Comprehensive International Classification of Functioning, Disability and Health Core Set for Head and Neck Cancer (ICF‐HNC) is an application of the ICF and guides multidisciplinary cancer follow‐up and rehabilitation in patients with head and neck cancer. The objective of this study was to understand the role of physicians within the multidisciplinary team and to explore the content validity of the ICF‐HNC from the perspective of physicians.

Methods

In a 3‐round Delphi survey, physicians experienced in the treatment of head and neck cancer were asked what patients' problems, resources, and aspects of environment they treat. The responses of the first round were linked to the ICF. In the second round the participants received a list of identified ICF categories and were asked if these ICF categories represent patients' problems, resources, and aspects of the environment they treat. Round 3 required a reconsideration of the given answers in accord with the group response. The agreement of the linking process between 2 health care professionals was calculated using kappa statistics.

Results

In all, 55 physicians from 25 countries gave 781 statements; 83 ICF categories were linked to the statements after the first round; 55 ICF categories reached consensus of ≥75% after the third round. Of these, 46 categories (84%) are already included in the ICF‐HNC. Within the entire ICF‐HNC, physicians treat most categories from body structures (88%) and functions (76%) and some categories from activities and participation (15%) and environmental factors (21%). The kappa coefficient for linking ICF categories was 0.988 (95% bootstrapped confidence interval: 0.95–0.99).

Conclusions

The content validity of the ICF‐HNC was supported by the perspective of physicians. This study supports the need for a multidisciplinary team. The aspects of functioning which are not treated by physicians should be addressed by timely involvement of other health professions. © 2011 Wiley Periodicals, Inc. Head Neck, 2012
Thrombin‐stimulated connective tissue growth factor (CTGF/CCN2) production in human buccal mucosal fibroblasts: Inhibition by epigallocatechin‐3‐gallate
Authors: Chang Jenny Zwei‐Chieng , Yang Wan‐Hsien , Deng Yi‐Ting , Chen Hsin‐Ming , Kuo Mark Yen‐Ping
Published: September 2011

Background

Connective tissue growth factor (CTGF/CCN2) is associated with many human fibrotic disorders and was found to overexpress in oral submucous fibrosis (OSF). OSF is the result of persistent chemical irritation and microtrauma to oral mucosa from areca nut. Microtrauma could lead to the release of thrombin.

Methods

Thrombin‐induced CCN2 expression and its signaling pathways were assessed by Western blot analyses in human buccal mucosal fibroblasts.

Results

Thrombin stimulated CCN2 synthesis in buccal mucosal fibroblasts via activation of protease‐activated receptor‐1. Pretreatment with antioxidant N‐acetyl‐L‐cysteine, apoptosis signal‐regulating kinase 1 inhibitor thioredoxin, and c‐Jun NH2‐terminal kinase inhibitor SP600125 significantly reduced thrombin‐induced CCN2 synthesis. Epigallocatechin‐3‐gallate completely inhibited thrombin‐induced CCN2 synthesis.

Conclusion

Thrombin produced by microtrauma may contribute to the pathogenesis of OSF by up‐regulating CCN2 expression. This effect could be mediated by protease‐activated receptor‐1, reactive oxygen species, apoptosis signal‐regulating kinase 1, and c‐Jun NH2‐terminal kinase pathways and prevented by epigallocatechin‐3‐gallate. © 2011 Wiley Periodicals, Inc. Head Neck, 2012
The role of melanoma tumor‐derived nitric oxide in the tumor inflammatory microenvironment: Its impact on the chemokine expression profile, including suppression of CXCL10
Authors: Tanese Keiji , Grimm Elizabeth A. , Ekmekcioglu Suhendan
Published: September 2011

Melanoma appears to be heterogeneous in terms of its molecular biology, etiology and epidemiology. We previously reported that the expression of inducible nitric‐oxide synthase (iNOS) in melanoma tumor cells is strongly correlated with poor patient survival. Therefore, we hypothesized that nitric oxide (NO) produced by iNOS promotes the melanoma inflammatory tumor microenvironment associated with poor outcome. To understand the role of NO and iNOS in the melanoma inflammatory tumor microenvironment, polymerase chain reaction arrays of inflammatory and autoimmunity genes were performed on a series of stage III melanoma lymph node metastasis samples to compare the gene expression profiles of iNOS‐expressing and nonexpressing tumor samples. The results indicate that expression of CXC chemokine ligand 10 (CXCL10) was inversely correlated with iNOS expression, and the high CXCL10‐expressing cases had more favorable prognoses than the low CXCL10‐expressing cases. Functional studies revealed that treating iNOS‐negative/CXCL10‐positive melanoma cell lines with a NO donor suppressed the expression of CXCL10. Furthermore, scavenging NO from iNOS‐expressing cell lines significantly affected the chemokine expression profile. Culture supernatants from NO scavenger‐treated melanoma cells promoted the migration of plasmacytoid dendritic cells, which was diminished when the cells were treated with a CXCL10‐neutralizing antibody. CXCL10 has been reported to be an antitumorigenic chemokine. Our study suggests that the production of NO by iNOS inhibits the expression of CXCL10 in melanoma cells and leads to a protumorigenic tumor microenvironment. Inhibiting NO induces an antitumorigenic environment, and thus, iNOS should be considered to be an important therapeutic target in melanoma.
Folate, vitamin B6, vitamin B12, methionine and alcohol intake in relation to ovarian cancer risk
Authors: Harris Holly R. , Cramer Daniel W. , Vitonis Allison F. , DePari Mary , Terry Kathryn L.
Published: September 2011

Folate, methionine, vitamin B6 and vitamin B12 may influence carcinogenesis due to their roles in the one‐carbon metabolism pathway, which is critical for DNA synthesis, methylation and repair. Low intake of these nutrients has been associated with an increased risk of breast, colon and endometrial cancers. Previous studies that have examined the relation between these nutrients and ovarian cancer risk have been inconsistent and have had limited power to examine the relation by histologic subtype. We investigated the association between folate, methionine, vitamin B6, vitamin B12 and alcohol among 1910 women with ovarian cancer and 1989 controls from a case‐control study conducted in eastern Massachusetts and New Hampshire from 1992 to 2008. Diet was assessed via food frequency questionnaire. Participants were asked to recall diet one‐year before diagnosis or interview. Logistic regression models were used to calculate odds ratios (OR) and 95% confidence intervals (95% CIs). We also examined whether the associations varied by ovarian cancer histologies using polytomous logistic regression. We observed an inverse association between dietary vitamin B6 (covariate‐adjusted OR = 0.76, 95% CI 0.64–0.92; ptrend = 0.002) and methionine intake (covariate‐adjusted OR = 0.72, 95% CI = 0.60–0.87; ptrend < 0.001) and ovarian cancer risk comparing the highest to lowest quartile. The association with dietary vitamin B6 was strongest for serous borderline (covariate‐adjusted OR = 0.49, 95% CI = 0.32–0.77; ptrend = 0.001) and serous invasive (covariate‐adjusted OR = 0.74, 95% CI = 0.58–0.94; ptrend = 0.012) subtypes. Overall, we observed no significant association between folate and ovarian cancer risk. One‐carbon metabolism related nutrients, especially vitamin B6 and methionine, may lower ovarian cancer risk.
Type and location of tumor‐infiltrating macrophages and lymphatic vessels predict survival of colorectal cancer patients
Authors: Ålgars Annika , Irjala Heikki , Vaittinen Samuli , Huhtinen Heikki , Sundström Jari , Salmi Marko , Ristamäki Raija , Jalkanen Sirpa
Published: September 2011

The type of tumor‐infiltrating macrophages may be decisive in tumor immunity, lymphangiogenesis and in the clinical outcome of cancer. Here, we elucidated the prognostic significance of lymphatic vessels, different types of macrophages and the balance between different macrophage types in colorectal cancer. We analyzed the impact of density, type and location of macrophages on the clinical behavior of 159 primary colorectal carcinomas using CD68 as a pan‐macrophage marker and CLEVER‐1/Stabilin‐1 as a marker for regulatory/suppressive macrophages. Podoplanin was used as a pan‐lymphatic vessel marker. A high number of CLEVER‐1/Stabilin‐1+ peritumoral macrophages positively correlated with survival (p = 0.04). However, in more advanced disease (Stage IV), the patients with a high number of peritumoral or intratumoral CLEVER‐1/Stabilin‐1+ macrophages had a shorter disease‐specific survival (p = 0.05, and p = 0.008, respectively). Moreover, a low number of suppressive intratumoral CLEVER‐1/Stabilin‐1+ macrophages among high numbers of CD68+ macrophages correlated with a low number of distant recurrences (p = 0.01) and to fewer disease relapses exclusively in the liver as well (p = 0.006). A high number of intratumoral lymphatics correlated with poor survival (p = 0.03). The results of this work suggest that the type of macrophages, number of lymphatic vessels and their location contribute to the clinical behavior of colorectal cancer in a disease stage‐specific manner.
Synthesis of 2‐Arylbenzoxazoles from Flash Vacuum Pyrolysis of 2‐Methoxy‐N‐(arenylidene)anilines
Authors: Chou Chin‐Hsing , Hsueh Yu‐Tan , Wang Bo‐Chi
Published: September 2011

Flash vacuum pyrolysis of 2‐methoxy‐N‐(arenylidene)anilines 2a‐g at 700 °C and 1 × 10‐2 Torr gave the corresponding 2‐arylbenzoxazoles 1a‐g.
Synthesis of Substituted 4‐Aroyl‐1‐indanone and 5‐Aroyl‐1‐tetralone
Authors: Chang Meng‐Yang , Lee Nien‐Chia
Published: September 2011

Several substituted 4‐aroyl‐1‐indanones 2 and 5‐aroyl‐1‐tetralones 3 were prepared in good yields from 1‐indanones 1 via a series of reasonable transformations.
Effect of Ultrasonic‐assisted Preparation Methods on Structure, Morphology and Optical Properties of Nanosized Cupric Oxide
Authors: Gharagozlou Mehrnaz , Rahnama Ahmad
Published: September 2011

Cupric oxide is a p‐type semiconductor with a narrow band‐gap which is suitable for catalysis, electrochemical cells, field emission devices and gas sensor applications. Despite considerable efforts devoted to the preparation of the nanosized CuO, there is a lack of information about ultrasonic‐assisted (US) preparation methods. Nanosized cupric oxide was successfully prepared through different ultrasonic‐assisted (US) preparation methods. Furthermore, the influence of preparation method on the structure, morphology and optical properties of nanosized CuO has been reported. XRD patterns were identical to the single‐phase pure CuO with a monoclinic structure. The enhancement of the crystallinity and crystallite size was observed for the sample prepared through the US thermal decomposition. The absorption band of CuO nanocrystals prepared through the US liquid hydrolysis shows a clear red shift of about 40 nm compared to those obtained with other preparation methods. Our results indicated that almost spherical CuO nanoparticles with an average size of 65 nm were prepared during the US thermal decomposition, while CuO rod‐like nanostructures with an average diameter of about 16 nm were obtained via the US liquid hydrolysis method. The band gap values of nanosized CuO samples were larger than the reported value for the bulk CuO. Synthesized CuO samples by US methods with adjustable and controllable properties make the applicability of cupric oxide even more versatile.
Dispersive Liquid‐Liquid Microextraction Followed by HPLC‐DAD as an Efficient and Sensitive Technique for the Determination of Patulin from Apple Juice and Concentrate Samples
Authors: Farhadi Khalil , Maleki Ramin
Published: September 2011

A simple and sensitive method based on dispersive liquid‐liquid microextraction (DLLME) in conjunction with high performance liquid chromatography‐diode array detection (HPLC‐DAD) has been developed for the quantitative analysis of patulin in apple juice and concentrate samples. The effect of extraction and disperser solvent (nature and volume), pH of sample solution, extraction time and extraction temperature was investigated. Under the optimal conditions the linear dynamic range of patulin was from 8.0 to 40.0 μg L‐1 with a correlation coefficient of 0.9993 and a detection limit of 4.0 μg L‐1. The relative standard deviation (RSD) was less than 5.9% (n = 5) and the recovery values were in the range of 94‐97%. Finally the proposed method was successfully applied for the analysis of patulin in apple juice and concentrate samples.
Electrodeposition CaCO3 Nanoparticles‐chitosan Composite Film on Carbon Ionic Liquid Electrode as a Platform for Hemoglobin Electrochemical Biosensor
Authors: Zhao Hong‐Ye , Zheng Jian‐Bin , Sheng Qing‐Lin
Published: September 2011

By one‐step co‐electrodeposition CaCO3 nanoparticles‐chitosan composite film on carbon ionic liquid electrode (CILE), and then by spreading the composition of hemoglobin (Hb) and chitosan on the nanoCaCO3‐chi/CILE, a Hb‐chi/nanoCaCO3‐chi/CILE was fabricated and the direct electrochemistry and electrocatalysis of Hb at the electrode was investigated. The electrochemical impedance spectroscopy of the modified electrode showed the electron transfer resistance was 1166 Ω. Investigation results of cyclic voltammetrys showed a pair of well‐defined and quasireversible redox peak of Hb with the formal potentials of ‐0.295 V (vs. SCE) in 0.1 mol·L‐1 pH 7.0 PBS; the response time of the reduction peak currents of Hb was lower than 3s; a linear range for determination of H2O2 was from 5.0 μmol·L‐1 to 1.3 mmol·L‐1 with a detection limit of 1.6 μmol·L‐1 (S/N = 3) and a sensitivity of 0.16 A·M‐1·cm‐2; the electron transfer rate constant and the apparent Michaelis‐Menten constant of Hb were 1.98 s‐1 and 0.81 mmol·L‐1, respectively. As a result, the case of the one‐step co‐electrodeposition and the promising feature of biocomposite could serve as a versatile platform for the fabrication of electrochemical biosensors.
Application of Net Analyte Signal Standard Addition Method (NASSAM) for Simultaneous Determination of Lead and Tin by Differential Pulse Polarography
Authors: Asadpour‐Zeynali Karim , Reza Majidi Mir , Vallipour Javad , Jafari Samira
Published: September 2011

Differential pulse polarography was used for simultaneous determination of Sn2+ and Pb2+. But there is a problem for simultaneous determination and it is high overlapped DPPs of mentioned cations that their determination is impossible in the presence of each other, so multivariate calibration methods as chemomatrics methods were used for this determination. There are some disadvantageous for multivariate calibration methods that can be solved by a new and simple method called net analyte signal standard addition method. This method has some advantages, such as: the use of a full voltammogram, realization in a single step, therefore it does not require calibration and prediction steps and only a few measurements are required for the determination.
Ionic Liquid [EMIM]OAc under Ultrasonic Irradiation towards Synthesis of 1,4‐DHP's
Authors: Reddy B. Palakshi , Rajesh K. , Vijayakumar V.
Published: September 2011

The ionic liquid 1‐ethyl‐3‐methylimidazole acetate ([EMIM]OAc) was found to be a mild and effective catalyst for the efficient, one‐pot, three‐component synthesis of 1,4‐dihydropyridines from arylaldehydes, ethylacetoacetate/acetylacetone and ammonium acetate at room temperature under sonication. The developed method has many advantages, including devoid of harmful catalysts, reacting at room temperature, higher yields in a simple methodology or operational convenience.
Purification, Characterization and N‐terminal Sequence Analysis of Betel Leaf (Piper betle) Invertase
Authors: Hossain Md. Murad , Pervin Farzana , Absar Nurul
Published: September 2011

The present study is the first report describing the purification, enzymatic properties and N‐terminal amino acid sequence of a native invertase in betel leaf. The invertase was purified as a monomeric glycoprotein of molecular mass (Mr) 68 kDa. The enzyme was capable to attack β‐fructofuranoside linkages from the fructose end of sucrose, raffinose and stachyose indicating it as an authentic β‐D‐fructofuranosidase with high specificity for sucrose (Km 4.83 mM). The maximum activity was detected at pH 5.2 and 37 °C. Glucose and fructose showed typical inhibitory effect on the enzyme activity where as lectin was found to be effective activators of the enzyme. Significant inhibition by heavy metal ion Hg2+ and sulfhydryl group modifying agents suggesting that free sulfhydryl group containing amino acid, cysteine is necessary for the catalytic activity of the invertase. A BLAST search of the N‐terminal amino acid sequence of betel leaf invertase showed significant homology with the homologous invertases in database.
Prenatal diagnosis of diastematomyelia: A case report and review of the literature
Authors: Li Sheng‐li , Luo Guoyang , Norwitz Errol R. , Wang Chenhong , Ouyang Shuyuan , Wen Hua‐xuan , Xia Xun , Yao Yuan
Published: September 2011

Diastematomyelia is a rare congenital disorder in which the spinal cord is divided longitudinally for part of its length. It can be accurately identified in the prenatal period by detailed sonographic examination of the spine. We report a case of diastematomyelia localized to spinal levels T6‐T9 diagnosed prenatally at 31 weeks' gestation and review the existing literature on the diagnosis and management of this condition during pregnancy. © 2011 Wiley Periodicals, Inc. J Clin Ultrasound, 2012
Synthesis of carbon‐14 labeled pyraoxystrobin, a novel fungicide
Authors: Liu Xun‐yue , Ye Qing‐fu , Kan Deng‐lei , Zhang Zheng , Ding Xing‐cheng
Published: September 2011

SYP‐3343, (E)‐2‐(2‐((3‐(4‐chlorophenyl)‐1‐methyl‐1H‐pyrazole‐5‐yloxy)methyl)) phenyl)‐3‐methoxyacrylate, is a novel fungicide with broad‐spectrum and high activity against fungi. In this paper, radioactive pyraoxystrobin, labeled in the pyrazole ring system was achieved from 14C labeled 4‐chlorobenzoic acid through substitution, cyclization, and condensation, in an overall chemical and radiochemical yield of 44%. The chemical and radiochemical purity of the title compound was 98.5% and 98.2%, respectively. This labeled SYP‐3343 was used as a radiotracer for metabolism, toxicology, mode of action, and other environmental studies. Copyright © 2011 John Wiley & Sons, Ltd.
Virtual worlds
Authors: Guthrie Kathy L. , Phelps Kirstin , Downey Steve
Published: September 2011

Games, role‐playing, and simulations as developmental tools have been used in education since the 1800s. An emerging form of collaborative game play is virtual worlds; however, the use of virtual worlds in leadership education has not been fully investigated. The purpose of this article is to (a) demonstrate how virtual worlds are a viable venue for leadership education, and (b) present a hierarchy of skills sets that can be developed in virtual world settings. In doing so, this article provides evidence that virtual worlds can be used as a new instructional delivery environment for leadership education as the appeal and intrinsic nature of virtual environments aligns well with the experiential framework of leadership education.
Perceptions and outcomes of a managerial coaching certificate program: Educational leaders vs. business leaders
Authors: Chandler Mary M. , Roebuck Deborah Britt , Swan William W. , Brock Stephen J.
Published: September 2011

Educational leaders face unprecedented changes in developing new strategies and processes that improve teacher effectiveness, student performance, and administrators' professional development. Coaching is a way to improve and increase performance. Educators are in a position to take advantage of coaching as used by business leaders all over the world. This study examined the effectiveness of a coaching model designed for managers in a college of business. The study included both educational (n = 5) and business leaders (n = 30). It examined their perceptions and outcomes of their participation. The results strongly support the efficacy of this coaching model.
Pervasive myths in leadership development: Unpacking constraints on leadership learning
Authors: Dugan John P.
Published: September 2011

Forty years ago, the questions most discussed among those who cared about leadership were “is leadership possible among those who don't have titles and positions?”; “what are the characteristics possessed by effective leaders?”; and “how do we find the people who are the best leaders and help them prepare for positions that will allow them to have an impact?” After many conversations, conferences, research studies, and books, the terrain has shifted among scholars. Now the conversations focus on questions such as “If leadership is a shared responsibility among members of groups, how can the full leadership potential of all be cultivated?”; “What role do collaborators play in empowering positive leadership and defending against those who misuse it?”; and “How can organizations cultivate cultures that support and encourage visionary leadership dedicated to benefitting all?”

The shift in the questions that leadership educators now explore, coupled with the breadth and variety of the initiatives dedicated to nurturing it, demonstrate that leadership can be taught. More importantly, the practice of leadership demonstrates that many can pursue leadership and that they must if the opportunities of the 21st century are to be fulfilled. The conversations and the needs for leadership have both shifted and it is now incumbent on those who value leadership most to agree to unifying perspectives that can draw us together in common purpose. From your vantage point, what are the crucial conversations, next steps, and/or thoughts for consideration as we enter the second decade of the 21st century?
Effect of J‐coupling on lipid composition determination with localized proton magnetic resonance spectroscopy at 9.4 T
Authors: Yahya Atiyah , Tessier Anthony G. , Fallone B. Gino
Published: September 2011

Purpose:

To demonstrate, at 9.4 T, that J‐coupling interactions exhibited by lipid protons affects lipid composition determination with a point resolved spectroscopy (PRESS) sequence.

Materials and Methods:

Experiments were conducted on four oils (almond, corn, sesame, and sunflower), on visceral adipose tissue of a euthanized mouse, and on pure linoleic acid at 9.4 T. The 2.1, 2.3, and 2.8 ppm resonances were measured at multiple echo times (TEs) by a standard PRESS sequence and by a PRESS sequence consisting of narrow‐bandwidth refocusing pulses designed to rewind the J‐coupling evolution of the target peak protons in the voxel of interest. T2 corrections were performed on both groups of data for the three peaks and lipid compositions for the oils and for the mouse tissue were determined. Lipid compositions were also calculated from a short‐TE standard PRESS spectrum.

Results:

A chemical analysis of the samples was not performed; however, the oil compositions calculated from resonance peaks acquired with the PRESS sequence designed to minimize J‐coupling effects, following T2 relaxation correction, closely agreed with values in the literature, which was not the case for all of the compositions determined from the regular PRESS spectra.

Conclusion:

The presented work brings to attention the significance of J‐coupling effects when calculating lipid compositions from localized proton spectra. J. Magn. Reson. Imaging 2011;. © 2011 Wiley Periodicals, Inc.
The antidepressant citalopram inhibits delayed rectifier outward K+current in mouse cortical neurons
Authors: Zhan Xiao‐Qin , He Yan‐Lin , Yao Jin‐Jing , Zhuang Jia‐Li , Mei Yan‐Ai
Published: September 2011

Citalopram, a selective serotonin (5‐HT) reuptake inhibitor (SSRI) as well as an antidepressant, is thought to exert its effects by increasing synaptic 5‐HT levels. However, few studies have addressed the possibility that citalopram has other molecular mechanisms of action. We examined the effects of citalopram on delayed rectifier outward K+current (IK) in mouse cortical neurons. Extracellular citalopram reversibly inhibited IKin a dose‐dependent manner and significantly shifted both steady‐state activation and inactivation curves toward hyperpolarization. Neither 5‐HT itself nor antagonists of 5‐HT and dopamine receptors could abolish citalopram‐induced inhibition of IK. In addition, intracellular application of GTPγ‐S similarly failed to prevent the inhibition of IKby citalopram. When applied intracellularly, citalopram had no effect on IKand did not influence the reduction of IKinduced by extracellular citalopram. The effect of citalopram was use dependent, but not frequency dependent, and it did not require channel opening. Electrophysiological recordings in acute cortical slice showed that citalopram significantly reduced the action potential (AP) firing frequency of cortical neurons and increased action potential duration (APD). The selective Kv2.1 subunit blocker Jingzhaotoxin‐III (JZTX‐III) did not abolish citalopram‐induced IKinhibition. Transfection of HEK293 cells with Kv2.1 or Kv2.2 constructs indicated that citalopram mainly inhibited Kv2.2 current. We suggest that citalopram‐induced inhibition of IKin mouse cortical neurons is independent of G‐protein‐coupled receptors and might exert its antidepressant effects by enhancing presynaptic efficiency. Our results may help to explain some of the unknown therapeutic effects of citalopram. © 2011 Wiley Periodicals, Inc.
Extracellular proteinase formation in carbon starving Aspergillus nidulans cultures – physiological function and regulation
Authors: Szilágyi Melinda , Kwon Nak‐Jung , Bakti Fruzsina , M‐Hamvas Márta , Jámbrik Katalin , Park HeeSoo , Pócsi István , Yu Jae‐Hyuk , Emri Tamás
Published: September 2011

Extracellular proteinase formation in carbon depleted cultures of the model filamentous fungus Aspergillus nidulans was studied to elucidate its regulation and possible physiological function. As demonstrated by gene deletion, culture optimization, microbial physiological and enzymological experiments, the PrtA and PepJ proteinases of A. nidulans did not appear to play a decisive role in the autolytic decomposition of fungal cells under the conditions we tested. However, carbon starvation induced formation of the proteinases observable in autolytic cultures. Similar to other degradative enzymes, production of proteinase was regulated by FluG‐BrlA asexual developmental signaling and modulated by PacC‐dependent pH‐responsive signaling. Under the same carbon starved culture conditions, alterations of CreA, MeaB or heterotrimeric G protein mediated signaling pathways caused less significant changes in the formation of extracellular proteinases. Taken together, these results indicate that while the accumulation of PrtA and PepJ is tightly coupled to the initiation of autolysis, they are not essential for autolytic cell wall degradation in A. nidulans. Thus, as Aspergillus genomes contain a large group of genes encoding proteinases with versatile physiological functions, selective control of proteinase production in fungal cells is needed for the improved industrial use of fungi. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Microbial diversity during Rotary Drum and Windrow Pile composting
Authors: Bhatia Akansha , Ali Muntzir , Sahoo Jitendra , Madan Sangeeta , Pathania Ranjana , Ahmed Naseem , Kazmi A. A.
Published: September 2011

This study investigates the prevailing microbial communities during the composting of vegetable waste, cattle manure and saw dust, in a household (250 l) batch scale Rotary Drum composter and Windrow Pile. Physico‐chemical parameters were analyzed to study the organic matter transformations. Total organic matter reduced from 63.8% to 36.2% in rotary drum and 39.6% in windrow pile composting. The C/N ratio decreased from 26.52 to 8.89 and 14.33 in rotary drum and windrow pile composting. The indigenous population of total heterotrophic bacteria decreased in rotary drum and windrow pile composting after 20 days. However, total fungal load initially increased within initial 4 days, then subsequently reduced in final composts. The average number of fecal coliforms and fecal Streptococci showed decrement with time, in both composting systems. Escherichia coli and Salmonella species number deduced during the study. Composting cycle started with Gram positive rods but ended up with the dominance of Gram negative bacilli shaped bacteria. Transformation of organic compounds during the biodegradation of organic waste, difference in the utilization of nutrients (organic matter) by the different group of microbes and high temperature could be cited as a possible reason of the above changes. Scanning electron microscopy has been used to obtain the surface structures of the cultured mycoflora. Results of the study revealed that higher diversity of microbes prevailed in rotary drum as compared to windrow pile, yielding more stable and pathogenic free compost in lesser period of composting. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Interactions between bicarbonate, potassium, and magnesium, and sulfur‐dependent induction of luminescence in Vibrio fischeri
Authors: Tabei Yosuke , Era Mariko , Ogawa Akane , Morita Hiroshi
Published: September 2011

In spite of its central importance in research efforts, the relationship between seawater compounds and bacterial luminescence has not previously been investigated in detail. Thus, in this study, we investigated the effect of cations (Na+, K+, NH4+, Mg2+, and Ca2+) and anions (Cl–, HCO3–, CO32–, and NO3–) on the induction of both inorganic (sulfate, sulfite, and thiosulfate) and organic (l‐cysteine and l‐cystine) sulfur‐dependent luminescence in Vibrio fischeri. We found that HCO3– (bicarbonate) and CO32– (carbonate), in the form of various compounds, had a stimulatory effect on sulfur‐dependent luminescence. The luminescence induced by bicarbonate was further promoted by the addition of magnesium. Potassium also increased sulfur‐dependent luminescence when sulfate or thiosulfate was supplied as the sole sulfur source, but not when sulfite, l‐cysteine, or l‐cystine was supplied. The positive effect of potassium was accelerated by the addition of magnesium and/or calcium. Furthermore, the additional supply of magnesium improved the induction of sulfite‐ or l‐cysteine‐dependent luminescence, but not the l‐cystine‐dependent type. These results suggest that sulfur‐dependent luminescence of V. fischeri under nutrient‐starved conditions is mainly controlled by bicarbonate, carbonate, and potassium. In addition, our results indicate that an additional supply of magnesium is effective for increasing V. fischeri luminescence. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Comparison of common lignin methods and modifications on forage and lignocellulosic biomass materials
Authors: Goff Ben M , Murphy Patrick T , Moore Kenneth J
Published: September 2011

BACKGROUND: A variety of methods have been developed for estimating lignin concentration within plant materials. The objective of this study was to compare the lignin concentrations produced by six methods on a diverse population of forage and biomass materials and to examine the relationship between these concentrations and the portions of these materials that are available for utilisation by livestock or for ethanol conversion.

RESULTS: Several methods produced lignin concentrations that were highly correlated with the digestibility of the forages, but there were few relationships between these methods and the available carbohydrate of the biomass materials. The use of Na2SO3 during preparation of residues for hydrolysis resulted in reduced lignin concentrations and decreased correlation with digestibility of forage materials, particularly the warm‐season grasses.

CONCLUSION: There were several methods that were well suited for predicting the digestible portion of forage materials, with the acid detergent lignin and Klason lignin method giving the highest correlation across the three types of forage. The continued use of Na2SO3 during preparation of Van Soest fibres needs to be evaluated owing to its ability to reduce lignin concentrations and effectiveness in predicting the utilisation of feedstuffs and feedstocks. Because there was little correlation between the lignin concentration and the biomass materials, there is a need to examine alternative or develop new methods to estimate lignin concentrations that may be used to predict the availability of carbohydrates for ethanol conversion. Copyright © 2011 Society of Chemical Industry
Exogenous mammalian sex hormones mitigate inhibition in growth by enhancing antioxidant activity and synthesis reactions in germinating maize seeds under salt stress
Authors: Erdal Serkan
Published: September 2011

BACKROUND: Mammalian sex hormones (MSH)—progesterone, β‐estradiol and androsterone—enhance plant growth and development by stimulating significant morphological and biochemical parameters under normal conditions. However, there is no report regarding their effects on plants exposed to environmental stress conditions. Therefore, the present study was focused on elucidating the possible positive effects of MSH on seedling growth, antioxidant activity and synthesis reactions in maize seeds exposed to salt stress, one of the most important environmental stresses. For this purpose, the various concentrations (10−6, 10−8, 10−10 and 10−12 mol L−1) of MSH were studied.

RESULTS: Salinity (100 mmol L−1 NaCl) significantly reduced root length and seedling height, whereas MSH treatment significantly ameliorated the adverse effects of salinity on root length and seedling height. On the other hand, although salinity increased soluble protein, soluble sugar and proline content in 7‐day‐old maize seedlings, these were higher in MSH‐treated seedlings. Similarly, MSH treatment augmented superoxide dismutase, peroxidase and catalase activities under salt stress, whereas it decreased superoxide production and lipid peroxidation level. The most favorable concentrations were determined as 10−8 mol L−1 for progesterone and β‐estradiol and 10−10 mol L−1 for androsterone.

CONCLUSION: Exogenous MSH application was found to have an important ameliorative effect on growth of seeds exposed to salt stress by stimulating antioxidant activity and synthesis reactions. This is the first study investigating the effects of MSH on germination of seeds exposed to stress conditions. Copyright © 2011 Society of Chemical Industry