bluuebunny/crossref_metadata_2025 huggingface dataset:
A Novel Multibranched Chromophore Containing Carbazole Moiety for Two-Photon Microfabrication
Authors: Hu Zhi Yuan , Guo Fu Quan , Liang Hao , Guo Bin
Published: February 2012

A novel multibranched chromophore containing carbazole moiety，4, 4´, 4´´-tris(9-carbazyl-trans-styryl) triphenylamine (TCSTPA)，was synthesized and characterized by 1HNMR and elemental analysis. A larger two-photon absorption (TPA) cross section of the chromophore was obtained as high as 2350 GM compared to that of the traditional linear chromophore when pumped by a femtosecond laser at 800 nm. Microstructure based on TPA induced polymerization with a spatial resolution of submicron was fabricated under much lower incident laser power using TCSTPA as a TPA photoinitiator and a multifunctional resin of pentaerythritol triacrylate (PETA) as a polymerizable monomer. The result indicates potential applications of this kind of chromophores with multibranched structural motif in the fabrication of polymer and functional microdevices.
A Residential Interactive End-Use Electric System with Electrical Engineering Materials Based on RTP and Load Forecasting
Authors: Zheng Yuan Ping , Niu Lin , Liang Yong Liang
Published: February 2012

As smart grid has been under rapid construction in China, this paper proposes an interactive information system according to the interaction feature of smart grid. End users are able to exchange electricity usage information with power utilities by using this system. Structures and functions of this system are demonstrated first. Smart meter plays a key role in the whole system and it is connected with other parts of the system by GPRS and serial communicating paths. Subsystems both of grid side and users side are designed in details. Information of real-time pricing(RTP) and load forecasting is applied to motivate users to participate the operation of the grid actively so that energy resources could be optimized and finally goals of economical and high-efficient using of energy can be achieved.
Numerical Study of Interior Trajectory of Missile Ejection Based on Mechanics
Authors: Liu Yong Quan , Xi An Min , Liu Hong Fei
Published: February 2012

An interior trajectory simulation of the gas-steam missile ejection has been developed with the help of FLUENT software. One of the special features of this simulation is the method by which the coupled two-phase problem is reduced to solving the fluid equations only. The calculation has been done efficiently in FLUENT after setting all the required parameters and adding the source terms. Several figures of the velocity and pressure have been given to show the flow field in the reservoir. The distribution curves of the velocity and acceleration of the missile show that the results of the simulation are in good agreement with the test data of the experiments. This model can be used to analyze the similar launch procedures in practice.
Preparation of Anion Exchange Membranes Base on Fluoro-Polyacrylate for Alkaline Fuel Cells
Authors: Fang Jun , Wu Yong Bin , Zhang Yan Mei
Published: February 2012

A series of hydroxyl conducting anion exchange membranes based on the copolymer of vinylbenzyl chloride, butyl methacrylate and fluoro-polyacrylate were prepared by radical polymerization, quaternization and alkalization. The reaction conditions of polymerization were discussed and the potential applications of the resulting membranes in alkaline fuel cells were assessed. The results show that the membranes have adequate conductivity for fuel cell application.
The Use of the Wii Fit in Forensic Mental Health: Exercise for People at Risk of Obesity
Authors: Bacon Nicola , Farnworth Louise , Boyd Richard
Published: February 2012

Introduction:

Side effects of psychotropic medication often lead to rapid weight gain, having detrimental effects on forensic mental health patients' health, wellbeing, occupational performance and quality of life. Virtual reality technology could provide novel environments and motivating forums for exercise, which are otherwise unavailable to patients in such secure settings. This exploratory study aimed to evaluate the use of the Nintendo Wii Fit in changing engagement in physical activity for patients at risk of obesity at a secure hospital.

Method:

Two participants used a Wii Fit for 8 weeks in individual or group sessions. A mixed methods approach was taken, because participants' use of the Wii Fit was compared with their attitudes towards it (reported during interviews) and their daily physical activity levels (measured using an accelerometer). Researcher field notes were also used to gather contextual data.

Findings:

Participants played Wii Fit up to four times a week in sessions ranging from 7 to 127 minutes. When using the Wii Fit, participants increased their overall time spent actively moving their bodies in physical activity, as measured by the accelerometer. Using the Wii Fit also changed participants' attitudes towards exercise as they realised that it could be ‘fun’ and ‘challenging’, especially if staff members also participated.

Conclusion:

The Wii Fit encouraged patients to attempt physical activities and to learn about their bodily response to exercise. It provided a meaningful occupational intervention in a secure setting and demonstrated a potential use of the technology in mental health settings.
Cenários, dilemas e caminhos da educação superior europeia
Authors: Magalhães António
Published: February 2012

A partir de um exercício de prospectiva efectuado pelo CHEPS, este artigo discute a cartografi a dos cenários futuros e dos presentes dilemas do ensino superior (ES) europeu. Trata-se de contribuir para a discussão da gestão política de sistemas massificados, da própria natureza do ES e de fazer assentar a agência dos actores envolvidos numa base que relativiza a assunção de que não há alternativas. O objectivo não é promover uma grande narrativa que prescreva um caminho privilegiado para o desenvolvimento do ES, mas, antes, identifi car posições e contribuir para o debate em torno das escolhas com que este se confronta.
Analysis of the vertical structure and size distribution of dust aerosols over the semi-arid region of the Loess Plateau in China
Authors: Zhou B. , Zhang L. , Cao X. , Li X. , Huang J. , Shi J. , Bi J.
Published: February 2012

Abstract. Using measurements of dual-wavelength polarisation lidar, particle sizer, and nephelometer from the Semi-Arid Climate and Environment Observatory of Lanzhou University (SACOL), the properties of dust aerosol extinction coefficient, optical depth, depolarisation ratio, colour ratio, size distribution, and concentration over the semi-arid region of the Loess Plateau in north-western China are analysed in a case study of dust storms from 16–18 March 2010. The results show that dust aerosols are distributed mostly within the lower layer (below 3.0 km), with the dust aerosol extinction coefficient ranging from 0.1 to 1.0 km−1. The average optical depth and depolarisation ratio are near 0.6 and 0.3, respectively, while the colour ratio ranges from 0.8 to 1.0. The mass size distribution of dust aerosols has two peaks at 0.7 μm and 5.0 μm, respectively, while the number size distribution of dust aerosols is log-normal with a maximum near 0.8 μm. Particles in the fine mode (r ≤ 2.5 μm) are predominant in the dust storm. Their number concentration decreases while those of particles in the moderate (2.5 μm < r ≤ 10.0 μm) and coarse (10.0 μm < r ≤ 20.0 μm) modes increase. Based on Mie theory and the number size distribution of the aerosol, the dust aerosol scattering coefficient and its variation with particle size are calculated and analysed. A fairly close correlation is found with that measured by the nephelometer, for which the correlation coefficients are 0.89 and 0.94, respectively, at 520 and 700 nm. It shows a Gaussian distribution of dust aerosol scattering coefficient against effective diameter, with a fitting coefficient of 0.96 and centre diameter of 5.5 μm. The contribution percentages of aerosol within fine, moderate, and coarse modes to dust aerosol scattering coefficient are 20.95%, 62.93%, and 16.12%, respectively, meaning that PM10 is a dominant factor in the dust aerosol scattering properties.
An early warning system for flash floods in hyper-arid Egypt
Authors: Cools J. , Vanderkimpen P. , El Afandi G. , Abdelkhalek A. , Fockedey S. , El Sammany M. , Abdallah G. , El Bihery M. , Bauwens W. , Huygens M.
Published: February 2012

Abstract. An early warning system (EWS) for flash floods has been developed for part of the Sinai peninsula of Egypt, an hyper-arid area confronted with limited availability of field data, limited understanding of the response of the wadi to rainfall, and a lack of correspondence between rainfall data and observed flash flood events. This paper shows that an EWS is not a "mission impossible" when confronted with large technical and scientific uncertainties and limited data availability. Firstly, the EWS has been developed and tested based on the best available information, this being quantitative data (field measurements, simulations and remote sensing images) complemented with qualitative "expert opinion" and local stakeholders' knowledge. Secondly, a set of essential parameters has been identified to be estimated or measured under data-poor conditions. These are: (1) an inventory of past significant rainfall and flash flood events, (2) the spatial and temporal distribution of the rainfall events and (3) transmission and infiltration losses and (4) thresholds for issuing warnings. Over a period of 30 yr (1979–2010), only 20 significant rain events have been measured. Nine of these resulted in a flash flood. Five flash floods were caused by regional storms and four by local convective storms. The results for the 2010 flash flood show that 90% of the total rainfall volume was lost to infiltration and transmission losses. Finally, it is discussed that the effectiveness of an EWS is only partially determined by technological performance. A strong institutional capacity is equally important, especially skilled staff to operate and maintain the system and clear communication pathways and emergency procedures in case of an upcoming disaster.
High ratio of resting energy expenditure to body mass in childhood and adolescence: A mechanistic model
Authors: Wang Zimian
Published: February 2012

Background:

Children have lower resting energy expenditure (REE) but higher ratio of resting energy expenditure to body mass (REE/BM) than do adults. This well‐known observation has never been quantitatively explained.

Objectives:

The aim of the present study is to understand the high REE/BM in childhood and adolescence.

Design:

A mechanistic REE/BM model is proposed. Literature data on REE, BM and the masses of four high metabolic rate organs (i.e., liver, brain, heart and kidneys) of 1–18 y boys and girls were used to evaluate the proposed REE/BM model. Specifically, we tested the hypothesis that the magnitude and variation of the REE/BM can be predicted by a combination of four variables, including relative cellularity, growth energy expenditure for constructing new cells, fraction of body mass as individual organs/tissues, and their specific resting energy expenditure.

Results:

The REE/BM provided by the literature is 54 kcal/kg per day at 1 year, decreasing to 26.0 kcal/kg per day at 18 years. Model‐predicted REE/BM can account for 97.0% and 100.7% of the literature‐reported REE/BM in males and females, respectively. The average differences between literature‐reported and model‐predicted REE/BM are 1.1 kcal/kg per day in boys and −0.3 kcal/kg per day in girls.

Conclusion:

The high REE/BM ratio in childhood results from two model variables: the high fraction of body mass as liver, brain, heart, and kidneys, and their high specific resting metabolic rates. The proposed REE/BM model promotes understanding of the REE, and allows a rational establishment of energy requirements for children and adolescents. Am. J. Hum. Biol., 2012. © 2012 Wiley Periodicals, Inc.
Technological Developments in IGCC for Carbon Capture
Authors: Prins M. , van den Berg R. , van Holthoon E. , van Dorst E. , Geuzebroek F.
Published: February 2012

Legislation will soon require significant carbon capture and sequestration (CCS) capabilities. The purpose of this paper is to show how advances in technology can further improve the high efficiencies of Integrated Gasification Combined Cycle (IGCC) power plants and to determine whether the efficiency penalty for pre‐combustion removal of CO2 can be minimized. An in‐house study was carried out and the methodology is explained. Technological developments are explained for IGCC in general, e.g., improved gas turbines, and for IGCC with CCS, e.g., in the field of more efficient water gas shift and CO2 removal processes. The results show that the 48 % coal‐to‐power efficiency can be surpassed and the efficiency penalty for CCS minimized to 7 %. This is possible using near‐commercial technologies.
Phase II study of Gleevec plus hydroxyurea in adults with progressive or recurrent low‐grade glioma
Authors: Reardon David A. , Desjardins Annick , Vredenburgh James J. , Herndon James E. , Coan April , Gururangan Sridharan , Peters Katherine B. , McLendon Roger , Sathornsumetee Sith , Rich Jeremy N. , Lipp Eric S. , Janney Dorothea , Friedman Henry S.
Published: February 2012

BACKGROUND:

We evaluated the efficacy of imatinib plus hydroxyurea in patients with progressive/recurrent low‐grade glioma.

METHODS:

A total of 64 patients with recurrent/progressive low‐grade glioma were enrolled in this single‐center study that stratified patients into astrocytoma and oligodendroglioma cohorts. All patients received 500 mg of hydroxyurea twice a day. Imatinib was administered at 400 mg per day for patients not on enzyme‐inducing antiepileptic drugs (EIAEDs) and at 500 mg twice a day if on EIAEDs. The primary endpoint was progression‐free survival at 12 months (PFS‐12) and secondary endpoints were safety, median progression‐free survival, and radiographic response rate.

RESULTS:

Thirty‐two patients were enrolled into each cohort. Eleven patients (17%) had before radiotherapy and 24 (38%) had received before chemotherapy. The median PFS and PFS‐12 were 11 months and 39%, respectively. Outcome did not differ between the histologic cohorts. No patient achieved a radiographic response. The most common grade 3 or greater adverse events were neutropenia (11%), thrombocytopenia (3%), and diarrhea (3%).

CONCLUSIONS:

Imatinib plus hydroxyurea was well tolerated among recurrent/progressive LGG patients but this regimen demonstrated negligible antitumor activity. Cancer 2012. © 2012 American Cancer Society.
Very long‐term follow‐up results of imatinib mesylate therapy in chronic phase chronic myeloid leukemia after failure of interferon alpha therapy
Authors: Kantarjian Hagop , O'Brien Susan , Garcia‐Manero Guillermo , Faderl Stefan , Ravandi Farhad , Jabbour Elias , Shan Jianqin , Cortes Jorge
Published: February 2012

BACKGROUND:

The long‐term outcome of patients with chronic phase chronic myeloid leukemia treated with imatinib after failure of interferon alpha therapy has not been detailed.

METHODS:

In total, 368 patients were analyzed. Univariate and multivariate survival analyses were conducted using standard statistical methods.

RESULTS:

Overall, 247 patients (67%) achieved a complete cytogenetic response (CCyR). Of the 327 patients who were studied, 207 patients (63%) achieved a major molecular response (MMR), and 99 patients (30%) had undetectable breakpoint cluster region/c‐abl oncogene (BCR‐ABL) levels at some time during therapy. The estimated 10‐year survival rate was 68%, the progression‐free survival rate was 67%, and the event‐free survival rate was 51%. In multivariate analysis, age ≥60 years, hemoglobin <10 g/dL, bone marrow basophils ≥5%, any peripheral blasts, and clonal evolution were independent adverse factors for survival. The estimated 7‐year survival rate according to the presence of no factors (n = 154), 1 or 2 factors (n = 190), or ≥3 factors (n = 24) were 93%, 70%, and 25%, respectively (P< .01). Achieving an MMR, a CCyR, or a partial cytogenetic response at 12 months was associated with significantly better 10‐year survival rate in a landmark analysis (10‐year survival rate, 80%‐90%) compared with achieving a minor cytogenetic response or a complete hematologic response (10‐year survival rate, 55%‐65%) or another response (10‐year survival rate, 10%). In a landmark analysis that included imatinib response at 12 months, achieving a major cytogenetic response or better (hazard ratio, 0.12;P< .001) and achieving a complete hematologic response or a minor cytogenetic response (hazard ratio, 0.36;P= .003) were significant favorable prognostic factors.

CONCLUSIONS:

The current results indicated that the estimated 10‐year survival rate of 68% for patients with chronic myeloid leukemia who receive imatinib after failure on interferon has improved. Cancer 2012;118: 3116–22. © 2011 American Cancer Society.
A Systematic Approach to Alkali Biuretooxophosphates
Authors: Wirnhier Eva , Schnick Wolfgang
Published: February 2012

Biuretooxophosphates represent a link between carbon nitride and phosphorus (oxo)nitride precursor chemistry being closely related to cyanurates and trimetaphosphimates. The group of alkali biuretooxophosphates has been complemented by the synthesis of four salts M[PO2(NH)3(CO)2]·xH2O in which M = Li, K, Rb, and Cs (x = 1, 0, 0.5, 0, respectively). The structures were solved by single‐crystal X‐ray diffraction and compared with the corresponding ammonium and sodium salts. For all of the salts, the 1‐phospha‐2,4,6‐s‐triazine ring exhibits a nearly planar conformation with the phosphorus atom being slightly deflected. In the sequence Li to Cs, the crystal structures show a significant change in orientation leading from a parallel to a perpendicular arrangement of the rings, the latter being bridged by N–H···O bonds. The thermal behavior of the biuretooxophosphates was examined by means of temperature‐dependent powder X‐ray diffraction measurements and combined thermogravimetric analysis (TGA) and differential thermal analysis (DTA). Moreover, the FTIR and photoluminescence spectra of the salts are discussed.
Development of a delirium risk screening tool for long‐term care facilities
Authors: McCusker Jane , Cole Martin G. , Voyer Philippe , Ciampi Antonio , Monette Johanne , Champoux Nathalie , Vu Minh , Belzile Eric
Published: February 2012

Objective

The aim of this study is to develop a delirium risk screening tool for use in long‐term care (LTC) facilities.

Methods

The sample comprised residents aged 65 years and over of seven LTC facilities in Montreal and Quebec City, Canada, admitted for LTC. Primary analyses were conducted among residents without delirium at baseline. Incident delirium was diagnosed using multiple data sources during the 6‐month follow‐up. Risk factors, all measured at or prior to baseline, included the following six groups: sociodemographic, medical, cognitive status, physical function, agitated behavior, and symptoms of depression. Variables were analyzed individually and by group using Cox regression models. Clinical judgment was used to select the most feasible among similarly performing factors.

Results

The cohort comprised 206 residents without delirium at baseline; 69 cases of incident delirium were observed (rate 7.6 per 100 person weeks). The best‐performing screening tool comprised five items, with an overall area under the curve of 0.82 (95% CI 0.76, 0.88). These items included brief measures of cognitive status, physical function, behavioral, and emotional problems. Using cut‐points of 2 (or 3) over 5, the scale has a sensitivity of 90% (63%), specificity of 59% (85%), and positive predictive value of 52% (66%).

Conclusions

This brief screening tool allows nurses to identify LTC residents at increased risk for delirium. These residents can be targeted for closer monitoring and preventive interventions. Copyright © 2012 John Wiley & Sons, Ltd.
Direct stimulation of the autonomic nervous system modulates activity of the brain at rest and when engaged in a cognitive task
Authors: Basile Barbara , Bassi Andrea , Calcagnini Giovanni , Strano Stefano , Caltagirone Carlo , Macaluso Emiliano , Cortelli Pietro , Bozzali Marco
Published: February 2012

The effect of autonomic perturbation (AP) on the central nervous system functioning is still largely unknown. Using an automated neck suction device to stimulate the carotid mechanoreceptors in the carotid sinus (parasympathetic pathway), operated synchronously with functional magnetic resonance imaging (fMRI) acquisition, we investigated the effects of AP on the activity of the brain at rest and when engaged in a visuo‐spatial attention task. ECG was always recorded to index changes in autonomic function. At rest, AP induced increased activation in the insula and in the amygdala, which have been previously associated with the autonomic control and emotion processing, as well as in the caudate nucleus and in the medial temporal cortex, both implicated in cognitive functions. Despite a preserved performance during visuo‐spatial attention task, AP induced increased reaction times and a positive modulation on the activation of the right posterior parietal cortex, the occipital cortex, the periaquiductal gray, and nuclei of the brainstem. We speculate that this modulation of brain activity represents, at different anatomical levels, a compensation mechanism to maintain cognitive efficiency under parasympathetic stimulation, which is traditionally considered as the system for energy regain and storage. In conclusion, this study provides the first evidence of a dynamic interaction between AP and higher level functions in humans. Hum Brain Mapp, 2013. © 2012 Wiley Periodicals, Inc.
Effect of annual endoscopic screening on clinicopathologic characteristics and treatment modality of gastric cancer in a high‐incidence region of Korea
Authors: Chung Su Jin , Park Min Jung , Kang Seung Joo , Kang Hae Yeon , Chung Goh Eun , Kim Sang Gyun , Jung Hyun Chae
Published: February 2012

We investigated risk factors for gastric cancer (GC) and effect of annual endoscopic screening on detection and treatment modality of GC. Asymptomatic adults who underwent upper endoscopy during health checkups at Seoul National University Hospital Healthcare System Gangnam Center were enrolled. We compared clinicopathologic characteristics of GC according to screening interval (repeated vs. infrequent, annual vs. biennial). After age‐ and sex‐matching, relative risk was computed by hazard ratio (HR) using Cox proportional regression with multivariate adjustment. Of the 58,849 subjects who received screening endoscopy, 277 (0.47%) were found to have GC. Intestinal type comprised 55.4% (102/184) followed by diffuse type (n = 65, 35.3%). Age ≥50 years, family history and smoking independently increased the risk of GC for both types, whereas male gender [HR = 4.81, 95% confidence interval (CI): 2.72–8.03] and intestinal metaplasia (IM) (HR = 10.87, 95% CI: 3.36–22.30) were significant predictors for intestinal type only. Proportion of early gastric cancer (EGC) was 98.6% (71/72) in annual screening group and 80.7% (46/57) in biennial screening group (p < 0.01). In the former, tumor size was smaller (1.7 ± 1.3 vs. 2.3 ± 1.8 cm; p < 0.01] and proportion of intramucosal cancer was larger (75.0 vs. 56.1%; p = 0.04). Endoscopic resection was performed more frequently in annual screening group (56.9 vs. 33.3%; p = 0.02). IM along with male gender and older age was a strong risk factor for intestinal type GC. Annual screening group improved detection of early‐stage and endoscopically treatable GC suggesting that intensive screening and surveillance may be useful for high‐risk subpopulations with epidemiologic risk factors or premalignant lesions such as IM.
The Personal Problems of College Students
Authors: DUREA M. A. , LOVE L. L.
Published: February 2012

What are some of the problems which disturb college students? Are these problems related to their academic standing? These are some of the questions answered in this study which was made of three hundred and four freshmen in the College of Education, Ohio State University. The technique of procedure and the tabulation and interpretation of results will be of interest to counselors and personnel workers.
Integrated multimodal optical microscopy for structural and functional imaging of engineered and natural skin
Authors: Zhao Youbo , Graf Benedikt W. , Chaney Eric J. , Mahmassani Ziad , Antoniadou Eleni , DeVolder Ross , Kong Hyunjoon , Boppart Marni D. , Boppart Stephen A.
Published: February 2012

An integrated multimodal optical microscope is demonstrated for high‐resolution, structural and functional imaging of engineered and natural skin. This microscope incorporates multiple imaging modalities including optical coherence (OCM), multi‐photon (MPM), and fluorescence lifetime imaging microscopy (FLIM), enabling simultaneous visualization of multiple contrast sources and mechanisms from cells and tissues. Spatially co‐registered OCM/MPM/FLIM images of multi‐layered skin tissues are obtained, which are formed based on complementary information provided by different modalities, i.e., scattering information from OCM, molecular information from MPM, and functional cellular metabolism states from FLIM. Cellular structures in both the dermis and epidermis, especially different morphological and physiological states of keratinocytes from different epidermal layers, are revealed by mutually‐validating images. In vivo imaging of human skin is also investigated, which demonstrates the potential of multimodal microscopy for in vivo investigation during engineered skin engraftment. This integrated imaging technique and microscope show the potential for investigating cellular dynamics in developing engineered skin and following in vivo grafting, which will help refine the control and culturing conditions necessary to obtain more robust and physiologically‐relevant engineered skin substitutes. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dissecting the “CHF admission”: An evidence‐based review of the evaluation and management of acute decompensated heart failure for the hospitalist
Authors: Kransdorf Evan P. , Kittleson Michelle M.
Published: February 2012

Acute decompensated heart failure (ADHF) is one of the most common conditions managed by hospitalists. Here we review the most recent evidence applicable to hospitalists for the diagnosis, risk stratification, and management of patients presenting with ADHF. By following a structured approach based on the patient's symptoms, history, physical examination, and laboratory testing, the clinician can make the diagnosis of heart failure efficiently. Because patients exhibit a wide spectrum of risk for adverse outcomes, both in the hospital and after discharge, assessing for clinical factors associated with these outcomes is essential. Congestion should be managed primarily with diuretics, and vasodilators may be helpful in certain patients. Given high rates of readmission, hospitalists should ensure that patients received evidence‐based therapy, heart failure education is performed, and follow‐up is in place before discharge. Journal of Hospital Medicine 2012; © 2012 Society of Hospital Medicine
Facile Preparation of Polymeric Dimers from Amphiphilic Patchy Particles
Authors: Wang Fengyang , Cheng Lin , Chen Tianhong , Zhu Dongsheng , Wen Qiang , Wang Shaowu
Published: February 2012

A straightforward strategy for assembling polymeric dimers from amphiphilic nanoparticles is reported. Amphiphilic polymeric nanoparticles with a mixed‐shell of PEO/P2VN blocks and a flexible core of PAA blocks are fabricated by a non‐covalent crosslinking method. Uniform polymeric dimers are efficiently and simply obtained via hydrophobic interactions under optimized conditions in selective solvent. The steric hindrance generated by reorganization of hydrophilic polymer brushes during the interparticle association is critical for morphological selectivity in the assembly. General applicability offers the possibility to organize functional NPs into superstructures with well‐defined geometry and association numbers.
Direct Cyclodextrin‐Mediated Ring Opening Polymerization of ϵ‐Caprolactone in the Presence of Yttrium Trisphenolate Catalyst
Authors: Li Xin , Zhu Yinghong , Ling Jun , Shen Zhiquan
Published: February 2012

Unmodified β‐cyclodextrin has been directly used to initiate ring‐opening polymerization of ϵ‐caprolactone in the presence of yttrium trisphenolate. Well‐defined cyclodextrin (CD)‐centered star‐shaped poly(ϵ‐caprolactone)s have been successfully synthesized containing definite average numbers of arms (Narm = 4–6) and narrow polydispersity indexes (below 1.10). The number‐average molecular weight () and average molecular weight per arm () are controlled by the feeding molar ratio of monomer to initiator. The prepared star‐PCL with of 2.7 × 103 is in fully amorphous and that with of 13.3 × 103 is crystallized. In addition, the obtained poly(e‐caprolactone) (PCL) stars with various molecular weights have different solubilities in methanol and tetrahydrofuran, which can be applied for further modifications.
Effect of Chain Microstructure and Cooling Rate on Crystaf Calibration Curves: An Experimental Study
Authors: Somnukguande Punnawit , Anantawaraskul Siripon , Soares João B.P.
Published: February 2012

Summary: Crystallization analysis fractionation (Crystaf) is a polymer characterization technique based on differences in chain crystallizabilities in a dilute solution during non‐isothermal crystallization. Crystaf profiles, a weight distribution function of chains crystallized at each temperature, can be used to infer the chemical composition distribution (CCD) of copolymers when a Crystaf calibration curve, a relationship between peak crystallization temperature and average comonomer content, is known. In this investigation, the effect of the number average molecular weight, comonomer type, and cooling rate on Crystaf calibration curves were experimentally investigated. It was found that the cooling rate and comonomer type may strongly affect Crystaf calibration curves, while the influence of molecular weight is relatively subtle.
An In Situ Small‐Angle X‐Ray Scattering Study of Propylene‐Butene and Propylene‐Ethylene Random Copolymers during Heating Process
Authors: Tang Yujing , Guo Meifang , Wang Qiao , Ren Minqiao , Song Wenbo
Published: February 2012

Summary: The micro‐structure evolution of isotactic polypropylene‐1‐butene (iPPBu) and polypropylene‐ethylene (iPPEt) random copolymers with 4 mol% of 1‐butene and ethylene was respectively investigated by differential scanning calorimetry (DSC) and in‐situ small angle X‐ray scattering (SAXS) techniques during heating process. The signal of melting enthalpy of iPPBu disappears a little earlier than that of iPPEt, which keeps consistent with the decay trend of scattering intensity during the late period of melting process. However, the SAXS data further show that the crystal thickness of iPPBu is a little larger than that of iPPEt during heating process. It is suggested that the melting behaviors of such copolymers depend on not only the lamellar thickness but also the crystal stability.
Morphological Changes of Linear, Branched Polyethylenes and their Blends during Crystallization and Subsequent Melting by Synchrotron SAXS and DSC
Authors: Sun Yingying , Fischer Stefan , Jiang Zhiyong , Tang Tao , Funari Sérgio S. , Gehrke Rainer , Men Yongfeng
Published: February 2012

Summary: The crystalline structure and phase morphology of linear, branched polyethylenes and their blends during crystallization and subsequent melting were investigated, using a combination of differential scanning calorimetry (DSC), and synchrotron small angle X‐ray scattering (SAXS). A linear polyethylene (PE1) with weight‐average molecular weight (Mw) of 114 000 g/mol, and two branched polyethylene copolymers, containing 4.8 mol% (PE4) and 15.3 mol% (PE10) hexane, with molecular weights of 93 000 g/mol and 46 000 g/mol were used as pure samples. Two blends, PE1‐4 and PE1‐10, each with a weight ratio of 50/50, were prepared by solution blending. Our results indicate that in PE4 a phase separation within the branched component itself occurred, forming a broad distribution of lamellar thicknesses during the crystallization process. PE10 on the other hand did hardly crystallize because of the high degree of branching. Co‐crystallization of both components took place in blend PE1‐4 and liquid‐liquid phase separation occurred in the melt of PE1‐10. Morphological parameters were determined by using Bragg's law and the correlation function, respectively. The detected semicrystalline morphology can be well described by the lamellar insertion mode where thin lamellae develop between thicker primary lamellae. During subsequent heating, lamellae melted in the reversed sequence of their formation. The evolution of the structural parameters as a function of temperature revealed that surface melting began at first, and then the complete melting of stacks occurred until the final melting temperature was reached.
Crystallization Elution Fractionation and Thermal Gradient Interaction Chromatography. Techniques Comparison
Authors: Monrabal Benjamin , Mayo Nuria , Cong Rongjuan
Published: February 2012

Summary: The chemical composition distribution has been shown to be the most critical and discriminating parameter in understanding the performance of industrial polyolefins with non homogeneous comonomer incorporation. The chemical composition distribution is being analyzed by well known techniques such as temperature rising elution fractionation, TREF, crystallization analysis fractionation, CRYSTAF and crystallization elution fractionation, CEF. These techniques separate according to crystallizability and provide a powerful and predictable separation of components based on the presence of branches, irregularities or tacticity differences, independently of the molar mass. TREF, CRYSTAF and CEF can not be used, however, for the separation of more amorphous resins, and may not always provide the best solution for complex multi‐component resins due to the existence of some co‐crystallization. The application of high temperature interactive HPLC to polyolefins opened a new route to characterize these types of polymers. The use of solvent gradient HPLC for separation of polyethylene and polypropylene and the developments in HPLC on carbon based columns extended further the application of high temperature HPLC in polyolefins. A new approach has been developed recently using the carbon based column but replacing solvent gradient by a thermal gradient which facilitates the analysis of polyethylene copolymers and provides a powerful tool for the analysis of elastomers. Thermal gradient interaction chromatography (TGIC) is being compared with TREF and CEF with the analysis of model samples. The advantages/disadvantages of each technique are being investigated and discussed. The combination of TGIC and TREF/CEF provides an extended range of separation of polyolefins.
Effect of Hydrogen, Electron Donor, and Polymerization Temperature on Poly(propylene) Microstructure
Authors: Alshaiban Ahmad , Soares João B. P.
Published: February 2012

Summary: Polypropylene made with an industrial heterogeneous Ziegler‐Natta catalyst was characterized using high temperature GPC, 13C NMR, and Crystallization Elution Fractionation (CEF). The effect of hydrogen and electron donor during polymerization on poly(propylene) microstructure was investigated at two temperatures. In addition to the expected electron donor effect on polypropylene tacticity, hydrogen was also found to increase polypropylene tacticity. The effect of changing these polymerization conditions on molecular weight and polydispersity was also investigated. Finally, CEF profiles show how the crystallizability of polypropylene increases by adding hydrogen and electron donor to the reactor.
“True” Concentration Determination Using a Concentration and Composition Sensitive Infrared Detector for Molecular Weight Characterization of Polyolefins
Authors: Huang Tianzi , Brown Raymond , Cong Rongjuan , Yau Wallace , Hazlitt Lonnie , deGroot A. Willem
Published: February 2012

Summary: The infrared detector with a composition channel provides the ability to construct “true” concentration of the polyethylene‐polypropylene copolymer and polymer blends to compensate the different infrared responses to each component. Using this “true” concentration constructed by the infrared detector, triple detector gel permeation chromatography (GPC) could generate conventional (by column calibration) and absolute (by laser light scattering) molecular weight and molecular weight distribution data comparable to data obtained by using the concentration obtained by a differential reflex index concentration detector. In addition to its unique feature of in‐situ composition detection, the infrared detector in its mass detection mode possesses the advantages of faster equilibrium time, more stable baseline, less effect from temperature variation, and low sensitivity to moisture or air in the solvent.
Teacher and observer ratings of young African American children's social and emotional competence
Authors: Humphries Marisha L. , Keenan Kate , Wakschlag Lauren S.
Published: February 2012

Children's social and emotional competence abilities have been linked to successful social interactions and academic performance. This study examined the teacher and observer ratings of social and emotional competence for 89 young (3‐ to 5‐year‐old), African American children from economically stressed urban environments. There was a specific interest in understanding the convergence and divergence of the raters on these competence behaviors within the classroom. This study also examined the association among children's competence abilities and their overall functioning at school. There were significant associations between teacher and observer reports of children's competence. Children who were observed to be socially and emotionally competent were rated by their teachers as functioning well in school. However, there were differences among teacher and observer reports in terms of the specific behaviors that represented social and emotional competence. These findings provide support for the use of multi‐method, multi‐informant measures to assess competence among African American children. © 2012 Wiley Periodicals, Inc.
Reading Experiences of Nonnative‐English‐Speaking Preservice English Teachers: A Turkish Case
Authors: Bektas‐Cetinkaya Yesim
Published: February 2012

In an EFL context, where language learners and users lack sufficient opportunities to receive oral input, reading in English plays a major role in improving nonnative preservice English teachers’ language proficiency and allowing them to access information recorded exclusively in English. The current study investigates prospective nonnative English teachers’ reading experiences in the Turkish EFL context by describing their reading activities, both in their native and target languages through print and on‐screen modes, inside and outside the classroom. These nonnative preservice English teachers reported reading less than four hours a day either for courses or pleasure. Second, they indicated that they read various materials both in Turkish and in English. However, this was mostly in Turkish, although English was their major. Lastly, almost all reported having an access to the Internet and the majority to a personal computer; however, they reported a preference for printed to on‐screen materials for physical, cognitive, and affective reasons.
STRONG CONVERGENCE OF SOME ALGORITHMS FOR λ-STRICT PSEUDO-CONTRACTIONS IN HILBERT SPACE
Authors: YAO YONGHONG , LIOU YEONG-CHENG , MARINO GIUSEPPE
Published: February 2012

Two algorithms have been constructed for finding the minimum-norm fixed point of a λ-strict pseudo-contraction T in Hilbert space. It is shown that the proposed algorithms strongly converge to the minimum-norm fixed point of T.
Circulating 25-hydroxyvitamin D levels in relation to blood pressure parameters and hypertension in the Shanghai Women's and Men's Health Studies
Authors: Dorjgochoo Tsogzolmaa , Ou Shu Xiao , Xiang Yong-Bing , Yang Gong , Cai Qiuyin , Li Honglan , Ji Bu-Tian , Cai Hui , Gao Yu-Tang , Zheng Wei
Published: February 2012

Little is known about the association of circulating 25-hydroxyvitamin D (25(OH)D) and blood pressure (BP) parameters, including systolic and diastolic BP, pulse pressure (PP), mean arterial pressure (MAP) and hypertension in non-Western populations that have not yet been exposed to foods fortified with vitamins and seldom use vitamin D supplements. A cross-sectional analysis of plasma 25(OH)D levels in association with BP measures was performed for 1460 participants (1055 women and 405 men, aged 40–74 years) of two large cohort studies in Shanghai. Multivariable linear and logistic regressions were conducted. Overall, the prevalence of vitamin D deficiency was 55·8 % using National Health and Nutrition Examination Survey, USA criteria and 29·9 % using WHO criteria. The median plasma 25(OH)D level in the population was 38·0 nmol/l for men and 33·6 nmol/l for women (P < 0·01) among participants who were not on antihypertensive drugs. Among men, BP parameters (systolic BP, diastolic BP and MAP) were significantly and inversely associated with higher quintiles of 25(OH)D compared with the lowest quintile (Ptrend < 0·05 for all). Vitamin D non-deficient status (WHO criteria) was inversely associated with hypertension (ORadjusted = 0·29; 95 % CI 0·10, 0·82). An inverse association was also found between hypertension and the highest quintile of 25(OH)D (ORadjusted = 0·16; 95 % CI 0·04, 0·65 for ≥ 50·6 nmol/l; Ptrend = 0·02). Among women, no significant associations were found for BP parameters and hypertension. The present study shows that vitamin D deficiency is common among adults in urban China. Circulating 25(OH)D levels were inversely related to the levels of individual BP parameters and hypertension among middle-aged and elderly men but not among women. More research is needed to investigate the potential sex differential associations.
CRUDE PROTEIN, AMINO ACID AND ALKALOID CONTENTS OF ANNUAL SWEET LUPIN (LUPINUS SPP.L.) FORAGES AND SEEDS GROWN IN ETHIOPIA
Authors: YEHEYIS LIKAWENT , KIJORA C. , VAN SANTEN E. , WINK M. , DANIER JÜRGEN , PETERS K. J.
Published: February 2012

Though bitter white lupin (Lupinus albusL.) is a traditional crop in Ethiopia, sweet lupins are new to the country. As a result, the nutritional value of low-alkaloid lupins has not been evaluated under Ethiopian conditions. Crude protein, amino acid and alkaloid contents of 16 cultivars of three annual lupin species grown in four lupin growing locations (Merawi, Finoteselam, Kossober-1 and Kossober-2) of Ethiopia were evaluated. Location × cultivar interaction was a significant source of variation for all traits (p< 0.0001). In all locations, blue entries had either similar (p≥ 0.0584) or higher (p≤ 0.0235) forage crude protein content than the Local Landrace, white group and yellow entry. Compared with the Local Landrace, white and blue entries, the sole yellow entry had higher (p≤ 0.0148) seed crude protein content at all locations except at Kossober-2, where it had similar (p= 0.8460) crude protein content as white entries. The Local Landrace had the highest forage and seed alkaloid contents. However, sweet blue Vitabor and Sanabor entries had the lowest forage and seed alkaloid contents, respectively. Low alkaloid and higher crude protein contents of sweet lupins grown in Ethiopia show the possibility to use sweet lupin forage and seeds as cheap home-grown protein source for livestock feed and human food in the country. However, for more reliable information, the laboratory results need to be verified by animal and human evaluations of the crop.
The effect of temperature on growth of early life stages of the common squid Loligo vulgaris
Authors: Moreno A. , Pierce G.J. , Azevedo M. , Pereira J. , Santos A.M.P.
Published: February 2012

The squid Loligo vulgaris has an extended spawning season within the upwelling system off north-west Portugal, and its paralarvae may thus develop under a wide range of environmental conditions. Both temperature and salinity are expected to affect the metabolism of young squid and we tested their effects on growth during the embryonic and post-hatching phase, based on measurements of growth increments in statoliths of juveniles and adults, using generalized additive models. There was no evidence that statolith increments representing early growth become unreadable in adult statoliths. Variability in the statolith size at hatching was weakly but significantly related to the variables in the model. On the other hand, the effects on statolith growth of both sea surface temperature and of sea bottom temperature were significant during early post-hatching life. Thicker increments are deposited in the statoliths of squid living under higher temperatures, which results in summer hatchers having larger statoliths at the age of 90 days. Inspection of the statolith accretion pattern, using a piecewise linear regression method, revealed an ontogenetic shift in increment width, which may be an indication of the age of transition from paralarva to juvenile. On this basis, it is suggested that the planktonic stage lasts 60 or 90 days, depending on whether the paralarvae lived at higher (>15°C) or lower (<15°C) sea surface temperatures. The life strategy under warmer conditions potentially favours survival by reducing the duration of the vulnerable planktonic phase.
Current status and conservation of the Endangered Przewalski's gazelleProcapra przewalskii, endemic to the Qinghai–Tibetan Plateau, China
Authors: Li Chunlin , Jiang Zhigang , Ping Xiaoge , Cai Jing , You Zhangqiang , Li Chunwang , Wu Yonglin
Published: February 2012

In 2008 Przewalski's gazelleProcapra przewalskii, endemic to the Qinghai–Tibetan Plateau, China, was recategorized from Critically Endangered to Endangered on the IUCN Red List. The species is still, however, threatened, and the human population and accompanying domestic livestock are increasing around Qinghai Lake. Here we provide up-to-date information on the distribution and population size of the species, evaluate its current conservation status and discuss the difficulties of protecting this gazelle species. We used both distance sampling and total counts to survey 16 sites where the species has been reported and found it at 13 of these, occupying a total area of c. 250 km2. Population size estimated from distance sampling (1,635) and total counts (1,544) was similar. About 20% of the gazelles located were in newly discovered areas for the species. The results indicate an overall growth in the population of Przewalski's gazelle since 2003, although some subpopulations have declined or been extirpated. In spite of conservation efforts Przewalski's gazelle is still threatened by habitat degradation and loss, habitat fragmentation, fencing, intensified competition with domestic livestock and predation. Further growth of this gazelle population is constrained by limited habitat availability and human–gazelle conflict. We recommend that management and conservation strategies need to incorporate comprehensive knowledge of the gazelle, long-term monitoring, and captive breeding of injured and orphaned gazelles to form a potential pool of individuals for future reintroductions to the historical range of the species outside the Qinghai Lake basin.