bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hierarchical Shelled ZnO Structures Made of Bunched Nanowire Arrays
Authors: Jiang P. , Zhou J.‐J. , Fang H.‐F. , Wang C.‐Y. , Wang Z. L. , Xie S.‐S. 
Published: April 2007

AbstractThe size‐ and morphology‐controlled growth of ZnO nanowire (NW) arrays is potentially of interest for the design of advanced catalysts and nanodevices. By adjusting the reaction temperature, shelled structures of ZnO made of bunched ZnO NW arrays are prepared, grown out of metallic Zn microspheres through a wet‐chemical route in a closed Teflon reactor. In this process, ZnO NWs are nucleated and subsequently grown into NWs on the surfaces of the microspheres as well as in strong alkali solution under the condition of the pre‐existence of zincate (ZnO22–) ions. At a higher temperature (200 °C), three different types of bunched ZnO NW or sub‐micrometer rodlike (SMR) aggregates are observed. At room temperature, however, the bunched ZnO NW arrays are found only to occur on the Zn microsphere surface, while double‐pyramid‐shaped or rhombus‐shaped ZnO particles are formed in solution. The ZnO NWs exhibit an ultrathin structure with a length of ca.  500 nm and a diameter of ca. 10 nm. The phenomenon may be well understood by the temperature‐dependent growth process involved in different nucleation sources. A growth mechanism has been proposed in which the degree of ZnO22–saturation in the reaction solution plays a key role in controlling the nucleation and growth of the ZnO NWs or SMRs as well as in oxidizing the metallic Zn microspheres. Based on this consideration, ultrathin ZnO NW cluster arrays on the Zn microspheres are successfully obtained. Raman spectroscopy and photoluminescence measurements of the ultrathin ZnO NW cluster arrays have also been performed.
Microporous Metal–Organic Frameworks with High Gas Sorption and Separation Capacity
Authors: Lee J. Y. , Olson D. H. , Pan L. , Emge T. J. , Li J. 
Published: April 2007

AbstractThe design, synthesis, and structural characterization of two microporous metal–organic framework structures, [M(bdc)(ted)0.5]·2 DMF·0.2 H2O (M = Zn (1), Cu (2); H2bdc = 1,4‐benzenedicarboxylic acid; ted = triethylenediamine; DMF: N,N‐dimethylformamide) is reported. The pore characteristics and gas sorption properties of these compounds are investigated at cryogenic temperatures, room temperature, and higher temperatures by experimentally measuring argon, hydrogen, and selected hydrocarbon adsorption/desorption isotherms. These studies show that both compounds are highly porous with a pore volume of 0.65 (1) and 0.52 cm3 g– 1 (2). The amount of the hydrogen uptake, 2.1 wt % (1) and 1.8 wt % (2) at 77 K (1 atm; 1 atm = 101 325 Pa), places them among the group of metal–organic frameworks (MOFs) having the highest H2 sorption capacity. [Zn(bdc)(ted)0.5]·2 DMF·0.2 H2O adsorbs a very large amount of hydrocarbons, including methanol, ethanol, dimethylether (DME), n‐hexane, cyclohexane, and benzene, giving the highest sorption values among all metal–organic based porous materials reported to date. In addition, these materials hold great promise for gas separation.
A fundamental equation of state for the (R134a + triethylene glycol dimethyl ether) mixture
Authors: Marchi Paolo , Scalabrin Giancarlo , Christian Ihmels E. , Richon Dominique 
Published: April 2007

AbstractThe thermodynamic properties of the mixture of 1,1,1,2‐tetrafluoroethane (R134a) and triethylene glycol dimethyl ether (TriEGDME) have been modeled with equations of state in an extended corresponding states format. A recent equation of state for pure R134a was assumed as the reference while the scale factors have been obtained in neural network form by regression of experimental data for the mixture. The modeling was focused on the liquid phase, considering the possible application of such a mixture in a refrigeration plant; since the vapor pressure of pure TriEGDME is negligible over the considered temperature range, the vapor phase of the mixture at vapor‐liquid equilibrium condition is almost pure R134a. Two fundamental equations are proposed herein. The first one, developed from a limited amount of experimental data is valid for R134a mole fractions greater than 0.94. The second equation was obtained from a wider data base; it has a larger number of free parameters to regress and covers the R134a mole fractions greater than 0.59. © 2007 American Institute of Chemical Engineers AIChE J, 2007
Musculoskeletal symptoms among poultry processing workers and a community comparison group: Black women in low‐wage jobs in the rural South
Authors: Lipscomb H.J. , Epling C.A. , Pompeii L.A. , Dement J.M. 
Published: April 2007

AbstractBackgroundPoultry processing is characterized by rapid line speed and extreme division of labor. Morbidity associated with this work has been reported by scientists, journalists and workers in this fast growing industry.MethodsCross‐sectional data from baseline measures of a cohort of black women employed in poultry processing (n = 291) and a community comparison group (n = 299) in rural North Carolina were used to evaluate musculoskeletal symptom reports and to explore factors associated with those reports. Recruitment of participants and collection of data were performed by women in the community circumventing the need to involve employers.ResultsSignificant differences in musculoskeletal symptom prevalence were observed between women employed in poultry processing and those of similar economic status employed elsewhere in the same area of rural northeastern North Carolina. After adjusting for other factors independently associated with symptoms among these women including age, depression, and perceived isometric load at work, the prevalence of upper extremity and neck symptoms was 2.4 (95% CI 1.7, 3.2) times higher among women working in poultry processing.ConclusionsThe findings add to the documentation of occupational health concerns among vulnerable workers employed in poultry processing in our state; in this economically depressed area of rural northeastern North Carolina poultry processing is the largest single employer of women. On a larger scale, the potential magnitude of upper extremity morbidity among women employed in poultry processing should be viewed with the knowledge that poultry processing is a growing industry in the U.S. with work done largely by blacks and immigrants. Am. J. Ind. Med. 50:327–338, 2007. © 2007 Wiley‐Liss, Inc.
Pesticide illness among flight attendants due to aircraft disinsection
Authors: Sutton Patrice M. , Vergara Ximena , Beckman John , Nicas Mark , Das Rupali 
Published: April 2007

AbstractBackgroundAircraft “disinsection” is the application of pesticides inside an aircraft to kill insects that may be on board. Over a 1‐year period, California's tracking system received 17 reports of illness involving flight attendants exposed to pesticides following disinsection.MethodsInterviews, work process observations, and a records review were conducted. Illness reports were evaluated according to the case definition established by the National Institute for Occupational Safety and Health.ResultsTwelve cases met the definition for work‐related pesticide illness. Eleven cases were attributed to the “Residual” method of disinsection, i.e., application of a solution of permethrin (2.2% w/w), solvents (0.8%), and a surfactant (1.4%); the method of disinsection could not be determined for one case.ConclusionsThe aerosol application of a pesticide in the confined space of an aircraft cabin poses a hazard to flight attendants. Nontoxic alternative methods, such as air curtains, should be used to minimize disease vector importation via aircraft cabins. Employers should mitigate flight attendant pesticide exposure in the interim. Am. J. Ind. Med. 50:345–356, 2007. © 2007 Wiley‐Liss, Inc.
Methylation of inorganic mercury by methylcobalamin in aquatic systems
Authors: Chen Baowei , Wang Thanh , Yin Yongguang , He Bin , Jiang Guibin 
Published: April 2007

AbstractThe methylation of inorganic Hg(II) by methylcobalamin in aquatic systems was studied using high‐performance liquid chromatography coupled with UV‐digestion cold vapor atomic fluorescence spectrometry (HPLC‐UV‐CV AFS). Monomethylmercury (MMC) could be positively identified as the reaction product in the aqueous solution. The salinity and pH of the aquatic system have great effects on the formation of MMC, because they could change the species of the reactants in the solution. From an electrophile reaction point of view, salinity and pH alter the electron density of the methyl donor and the electrophilicity of metal ion in the reaction system. This methylation of inorganic Hg(II) is shown to be possible even in highly saline solutions, which indicates its importance in aquatic environments. Kinetic experiments showed that the methylation reaction was fast and first‐order for Hg(II). The first‐order reaction rate was determined to be 0.00612 and 0.000287 min−1 for pH 5.0 and 1.5, respectively. It is suggested that this methylation could occur in the absence of enzymes, in which Hg(II) acts as an electrophile to attack methylcobalamin with a subsequent transfer of carbanion methyl group to the higher oxidized state of Hg(II). Copyright © 2007 John Wiley & Sons, Ltd.
Development of a slow non‐viral DNA release system from PDLLA scaffolds fabricated using a supercritical CO2 technique
Authors: Heyde Mieke , Partridge Kris A. , Howdle Steven M. , Oreffo Richard O.C. , Garnett Martin C. , Shakesheff Kevin M. 
Published: April 2007

AbstractPolyamidoamine polymers (PAA) comprising methylene‐bisacrylamide/dimethylethylene‐diamine monomers were synthesized, complexed with DNA and incorporated into porous PDLLA scaffolds by using a supercritical CO2 (scCO2) technique. Scaffolds were made in a dry state consequently there was a need to lyophilize the complexes. A statistically significant reduction of the transfection efficiency was observed in the absence of trehalose when compared to the original complex after freeze‐drying. Increasing concentrations (0–10% w/v) of trehalose were added to the complex prior to freeze‐drying. Structure dependent differences in DNA binding were evaluated by gel electrophoresis and thermal transition analysis. TEM and PCS showed aggregate formation after freeze‐drying without trehalose. Scaffolds were characterized by pore sizes of 173 ± 73 µm and a porosity of 71%. The transfection potential of the released DNA was investigated by seeding scaffolds with A549 cells and following firefly luciferase as a marker gene after 48 h exposure. Low but continuous levels of transfection were observed for PAA complexes during a 60‐day study. Complexes made with Lipofectamine™ gave initially higher levels of DNA release but no further expression was seen after 40 days. Uncomplexed DNA showed background levels of transfection. Culturing cells on 3D scaffolds showed a benefit in retention of transfection activity with time compared to 2D controls. Transfection levels could be increased when cells were grown in OptiMEM. This study demonstrated that PAA/DNA complexes incorporated into a PDLLA scaffold made by using scCO2 processing exhibited a slow release and extended gene expression profile. Biotechnol. Bioeng. 2007;98: 679–693. © 2007 Wiley Periodicals, Inc.
Expectations and motivations of Hondurans migrating to the United States
Authors: Sladkova Jana 
Published: April 2007

AbstractThis study explores the expectations and decision‐making processes of potential migrants at a community in Honduras. Hondurans have become one of the fastest growing populations in New York. Yet, although approximately 80 000 Hondurans try to reach the US annually, only 25 per cent succeed. To reach the United States they must undergo a dangerous journey across Guatemala and Mexico, a process to date under‐researched by social sciences. As new undocumented migrant streams continue to expand within the global economies, scholars and practitioners who work on their behalf should understand the pre‐migration values and expectations because they shape the way migrants adjust to and develop new cultural patterns in the receiving countries. Drawing on immigration and narrative theory, I hypothesize that narratives of migration from media, prior migrants, coyotes and community practices play an important role in the construction of potential migrant expectations. To represent narratives across several individual and community domains, the research design includes individual interviews, analysis of local newspapers, participant observations and teaching English classes. Analysis across these data reveals complex dilemmas potential migrants face as they weigh the costs and benefits of migration. Copyright © 2007 John Wiley & Sons, Ltd.
Adolescent motherhood: a Q‐methodological re‐evaluation of psychological and social outcomes
Authors: Richards Jan , Papworth Mark , Corbett Sally , Good James 
Published: April 2007

AbstractTraditionally, adolescent motherhood has been associated with numerous negative social, psychological and societal outcomes. However, in recent years there has been a gradual acceptance that there are many positive features to adolescent motherhood, but methodological issues have been identified within the field. This study aimed to examine adolescent motherhood from the mothers' own perspectives, exploring their attitudes towards the issues that they described as being important in their lives, by using Q‐methodology in an attempt to counter some of these methodological limitations. The mothers within the study appeared to be coping positively in their role in that levels of symptomatology, as determined from questionnaire assessment, appeared to be relatively low and they indicated through Q‐sort analysis that motherhood had been beneficial to their lives. Three independent factors (clusters of attitudes) were identified within the sample (N = 23) which differed over the dimensions of: employment, social support, coping, partner co‐habitation, financial support, maternal role satisfaction, aspirations for the future, as well as the nature of the relationship with their child(ren)'s father and their satisfaction with the fathers' role. The significance of these findings with regard to educational and social services is discussed. Copyright © 2007 John Wiley & Sons, Ltd.
DNA–Protein Noncovalent Cross‐Linking: Ruthenium Dipyridophenazine Biotin Complex for the Assembly of Proteins and Gold Nanoparticles on DNA Templates
Authors: Slim Mohamed , Durisic Nela , Grutter Peter , Sleiman Hanadi F. 
Published: April 2007

AbstractWe report the first example of a small molecule that can noncovalently cross‐link DNA with streptavidin and streptavidin‐labeled materials. Molecule 1 possesses a ruthenium dipyridophenazine DNA‐intercalating moiety and a biotin unit; these two units are adequately separated to ensure efficient cross‐linking of DNA with protein. Complex 1 is essentially nonemissive in aqueous solution and when bound to streptavidin, however, its luminescence is turned “on” when it binds to DNA. We have used these properties to establish that this complex can simultaneously bind to DNA and streptavidin, and can thus bring these two biomolecules together. We also synthesized a related molecule, 3, in which the biotin and DNA‐intercalating moieties are covalently bound. While complex 3 can intercalate into DNA through a threading mechanism, luminescence experiments show that it cannot simultaneously bind DNA and streptavidin, most likely due to the proximity of its two molecular‐recognition units. The cross‐linking ability of molecule 1 was used to template the assembly of streptavidin molecules on circular plasmid DNA, as visualized by atomic force microscopy. In addition, using 1, we show the organization of discrete groups of gold nanoparticles labeled with streptavidin on a linear DNA template of finite size, with transmission electron microscopy. In these experiments the DNA template acted as a “molecular ruler” that dictated the number of particles in the assembly.
Risk factors for malignancy in Japanese renal transplant recipients
Authors: Imao Tetsuya , Ichimaru Naotsugu , Takahara Shiro , Kokado Yukito , Okumi Masayoshi , Imamura Ryoichi , Namba Yukiomi , Isaka Yoshitaka , Nonomura Norio , Okuyama Akihiko 
Published: April 2007

AbstractBACKGROUND.Among recipients of renal transplants, the incidences of renal cancer and gastrointestinal cancer are higher and that of skin cancer is much lower in Japan than in Europe and North America.METHODS.The risk factors for the development of malignant tumors were examined in Japanese recipients of renal transplants. A total of 556 patients underwent renal transplantation at the Department of Urology, Osaka University Faculty of Medicine between March 1, 1965, and April 31, 2004. Of these patients, 366 were retrospectively studied in whom risk factors potentially related to the development of malignancy could be evaluated on the basis of medical records. The incidence of malignancy, survival rate, and risk factors for malignancy were examined.RESULTS.The overall incidence of malignancy was 6.8% (25/366 patients). Six of the 25 patients with malignancy died of cancer, but there was no correlation between the occurrence of malignancy and the survival rate (P = .8058, log‐rank test). A Cox proportional‐hazards model identified treatment with tacrolimus (hazard ratio [HR] = 4.376; 95% confidence interval [CI]: 1.647–11.627; P = .0031) and age at transplantation (HR = 1.562; 95% CI: 1.089–2.240; P = .0155) as risk factors for malignancy.CONCLUSIONS.The results of multivariate analysis suggested that age at transplantation and the use of tacrolimus were independent risk factors for the development of malignancy in recipients of renal transplants. Cancer 2007. © 2007 American Cancer Society.
The role of interstitial brachytherapy with salvage surgery for the management of recurrent head and neck cancers
Authors: Kupferman Michael E. , Morrison William H. , Santillan Alfredo A. , Roberts Dianna , Diaz Eduardo M. , Garden Adam S. , Weber Randal 
Published: April 2007

AbstractBACKGROUNDThe role of interstitial brachytherapy (IBT) in the salvage surgical management of regional lymphatic metastases for head and neck cancer has not been defined to date. To further explore its therapeutic benefit in the management of head and neck squamous cell carcinoma, the authors reviewed their experience utilizing IBT at the M. D. Anderson Cancer Center.METHODSA retrospective chart review of all patients who were received IBT for cervical recurrences of head and neck cancer was undertaken. Twenty‐two patients were identified; all patients underwent neck dissection and intraoperative placement of afterloading catheters as part of the salvage treatment. Soft tissue reconstruction was performed when necessary. The duration and dosage of salvage brachytherapy was reviewed, and the overall disease‐free survival rates were determined.RESULTSAll patients had been treated with external beam radiation therapy prior to recurrence, with an average dose of 65 grays (Gy), and 46% of patients had undergone prior neck dissection. The median time to regional recurrence after definitive treatment was 30 months. Soft tissue coverage of the surgical bed with a muscle flap, most commonly a pectoralis major flap, was performed in 19 of 22 patients. The median IBT dose was 60 Gy over a total duration of 4 days. Postoperative complications were few, and there were no perioperative deaths. Recurrences in the reirradiated necks occurred in 27% of patients.CONCLUSIONSRegional recurrences are common after multimodality treatment for head and neck cancer and are challenging to manage. Although its role has not been defined clearly, salvage neck dissection with IBT is beneficial in the management of recurrent lymphatic metastases of upper aerodigestive tract carcinomas. Cancer 2007. © 2007 American Cancer Society.
QoS‐aware mobile service transactions in a wireless environment
Authors: Younas Muhammad , Chao Kuo‐Ming , Wang Ping , Huang Chun‐Lung 
Published: April 2007

AbstractMobile computing greatly facilitates the provision of mobile services using portable and handheld devices which are connected through wireless networks. A pre‐requisite for the provision of an effective service is to ensure quality of service (QoS) during the concurrent execution of requests and system or network failures. This paper presents a new transaction management approach for the provision of mobile services which is based on advanced transaction models and fuzzy selection criteria. It employs a novel QoS consensus moderation approach in order to select preferred mobile services from among various alternatives, thus providing multiple pathways to the completion of mobile service transactions. Unlike traditional transaction management schemes, the proposed approach takes into account QoS attributes in the commit process of mobile service transactions. The proposed approach is implemented as a prototype tool and evaluated through a number of experiments. Experimental results show that the proposed approach effectively selects mobile services and significantly increases the throughput (i.e. commit rate) of mobile service transactions. Copyright © 2007 John Wiley & Sons, Ltd.
DS/CDMA throughput of a multi‐hop sensor network in a Rayleigh fading underwater acoustic channel
Authors: Mar Choong Hock , Seah Winston K. G. 
Published: April 2007

AbstractAsynchronous half‐duplex Direct‐Sequence Code‐Division Multiple‐Access (DS/CDMA) is a suitable candidate for the MAC protocol design of underwater acoustic (UWA) sensor networks owing to its many attractive features. Our ad‐hoc multi‐hop network is infrastructureless in that it is without centralized base stations or power control. Hence, we develop an asynchronous distributed half‐duplex control protocol to regulate between the transmitting and receiving phases of transmissions. Furthermore, multi‐hop communications are very sensitive to the time variability of the received signal strength in the fading channel and the ambient noise dominated by snapping shrimp in harsh underwater environments, because a broken link in the multi‐hop path is enough to disrupt communications and initiate new route searches. In our configuration, we use the Ad hoc On‐demand Distance Vector (AODV) routing protocol optimized for UWA networks. Empirical studies show that we can model the channel as a slow‐varying frequency non‐selective Rayleigh fading channel. We theoretically analyze the throughput of our configuration by considering three salient features: the ability of the receiver to demodulate the data, the effect of our control protocol and the effect of disconnections on the generation of routing packets. The throughput under various operating conditions is then examined. It is observed that at optimal node separation, the throughput is improved by a factor of 10. Copyright © 2007 John Wiley & Sons, Ltd.
Fast synchronization for quasi‐immutable objects
Authors: Nishiyama Hiroyasu , Nakajima Kei 
Published: April 2007

AbstractIncreasing synchronization performance is one of the most important factors for improving Java performance. We present the concept of quasi‐immutable objects and its application to implement fast synchronization primitives. Quasi‐immutable objects are usually used for read accesses, but they are rarely used for write accesses. Using these characteristics, we describe the optimization for a synchronized read sequence of quasi‐immutable objects. Our described method dynamically detects objects that are not written from critical sections of other threads, and applies the fast read sequence. The optimized read sequence enables the simultaneous execution of critical sections by multiple threads and reduces synchronization overhead. We implemented the described optimization on HotSpot Java VM. The experimental evaluations indicated that the optimization improved the performance of a micro‐benchmark up to a factor of 16 and SPEC benchmarks up to 31%. Copyright © 2007 John Wiley & Sons, Ltd.