bluuebunny/crossref_metadata_2025 huggingface dataset:
Characteristics of land surface heat and water exchange under different soil freeze/thaw conditions over the central Tibetan Plateau
Authors: Guo Donglin , Yang Meixue , Wang Huijun
Published: January 2011

Freezing and thawing processes at the soil surface play an important role in determining the nature of Tibetan land and atmosphere interactions. In this study, land surface water and heat exchanges under different freezing and thawing conditions over the central Tibetan Plateau were investigated using observations from the Coordinated Enhanced Observing Period/Asia‐Australia Monsoon Project on the Tibetan Plateau, and the Simultaneous Heat and Water Model. During the freezing and thawing stages, significant diurnal variation of soil temperature resulted in a diurnal cycle of unfrozen water content at the surface. Radiation and energy components and evapotranspiration averaged over four freeze/thaw stages also changed diurnally. On average, the surface albedo (0·68) during the completely frozen stage was sharply higher than those during the freezing, thawing, and completely thawed stages due to the snow cover. The Bowen ratios were 3·1 and 2·5 in the freezing and thawing stages, respectively, but the ratio was only 0·5 in the completely thawed stage. Latent heat flux displayed distinctly better correlation with unfrozen soil water content during the freezing and thawing stages than during the completely frozen and thawed stages. This implies that the diurnal cycle of unfrozen soil water, resulting from diurnal freeze/thaw cycles at the surface, has a significant impact on latent heat flux. A surface energy imbalance problem was encountered, and the possible sources of error were analysed. Copyright © 2011 John Wiley & Sons, Ltd.
Rural homes and urban dwellings? Gender, migration and the importance of tenure in Gaborone, Botswana
Authors: Datta Kavita
Published: January 2011

Migration studies in the Third World have largely regarded the movements of women as being identical to those of men. Recent work has shown that not only are women migrating in increasing numbers but that their movement also varies from that of men in terms of motives and length of stay in the destination area.

Moreover, there is a great deal of geographical variability in female migration patterns so that women are encouraged to migrate in some countries while the movements of others are restricted. The issue of return migration has been widely debated in African migration literature in view of strong rural‐urban ties and urban growth based largely on in‐migration. On the basis of fieldwork in Botswana, it is argued that there are important gender differences in terms of the commitment to rural and urban areas. It has been postulated in past studies that the decision to remain in towns depends in part upon urban tenure and it is argued that home owners are more likely than tenants to be permanent urban dwellers. Again, there are important gender differences and women appear to be more committed to the urban dwelling than men.
A novel collagen/hydroxyapatite/poly(lactide‐co‐ε‐caprolactone) biodegradable and bioactive 3D porous scaffold for bone regeneration
Authors: Akkouch Adil , Zhang Ze , Rouabhia Mahmoud
Published: January 2011

The goal of this study was to design a nontoxic scaffold with both composition and microstructure suitable for bone engineering using collagen (Coll), hydroxyapatite (HA), and poly(lactide‐co‐ε‐caprolactone) (PLCL). Mineralized type I Coll was produced by direct nucleation of HA particles inside self‐assembled Coll fibers to obtain a Coll/HA complex, which was then added to dissolved PLCL (70:30) in 1,4‐dioxane. A 3D porous Coll/HA/PLCL scaffold was subsequently produced through freeze‐drying/lyophilization and salt‐leaching procedures. The resulting Coll/HA/PLCL scaffold displayed a high uniform porosity and highly interconnected pores. X‐ray photoelectron spectrometer and Fourier transform infrared analyses revealed the presence of both collagen and HA particles on the surface of the Coll/HA/PLCL scaffold. Proliferation assay, microscopic observations, and gene analysis with quantitative RT–PCR showed that osteoblast cells were able to attach, proliferate, and maintain an osteoblastlike phenotype when cultured on the Coll/HA/PLCL scaffold. In summary, we produced a nontoxic scaffold that contains natural polymers (Coll and HA) and synthetic polymer (PLCL). Through its chemical composition and porous morphology, this scaffold may be useful for osteoblast growth, differentiation, and bone tissue formation. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 2011.
Preliminary in vivo study of apatite and laminin‐apatite composite layers on polymeric percutaneous implants
Authors: Oyane Ayako , Hyodo Koji , Uchida Masaki , Sogo Yu , Ito Atsuo
Published: February 2011

A polymeric material coated with a hydroxyapatite (HA) layer would be useful as a flexible percutaneous device with good biocompatibility and resistance to bacterial infection. We have recently developed a simple, safe, and mild coating process to form an HA layer on the surfaces of polymeric materials. In this study, our coating process was applied to an ethylene‐vinyl alcohol copolymer film. The resulting HA‐coated film was percutaneously implanted in the scalp of a rat to examine the stability and biocompatibility of the HA layer. From the results of histological analysis, the HA layer remained undissolved on the film surface under the skin tissue even 3 days after implantation. Owing to the good biocompatibility of HA, the HA‐coated film suppressed a host's foreign‐body response and integrated with the surrounding skin tissue for as long as 14 days, in a similar fashion to a conventional percutaneous device composed of ceramic HA. Immobilization of a cell adhesion protein, laminin, into the HA layer was found to improve the adhesion strength between the film and the surrounding skin tissue without compromising good biocompatibility of HA. Our coating process to form HA and laminin‐HA composite layers would be useful in fabricating polymeric percutaneous devices with a reduced risk of bacterial infection, although further in vivo studies are required. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
Correlating hypoxia with insulin secretion using a fluorescent hypoxia detection system
Authors: Skiles Matthew L. , Fancy Romone , Topiwala Pritesh , Sahai Suchit , Blanchette James O.
Published: February 2011

A common obstacle to the survival of encapsulated tissue is oxygen insufficiency. This appears particularly true of encapsulated pancreatic β‐cells. Our work investigates a fluorescent hypoxia detection system for early recognition of hypoxic stress in encapsulated pancreatic tissue. Murine insulinoma (MIN6) cells were engineered to produce a red fluorescent protein under the control of hypoxia‐inducible‐factor‐1. Aggregates of these cells were encapsulated in poly(ethylene glycol) hydrogels at densities of 200,000, 600,000, and 1 million cells per capsule then incubated in either a 1% or 20% oxygen environment. Cell function was evaluated by daily measurement of glucose‐stimulated insulin secretion. Encapsulated cells were also fluorescently imaged periodically over 72 h for expression of the marker signal. Results indicate that oxygen insufficiency severely impacts insulin release from MIN6 cells, and that large aggregates are especially vulnerable to oxygen limitations. Our marker was found to be successfully indicative of hypoxia and could be used as a predictor of subsequent insulin release. Further work will be required to fully characterize signal dynamics and to evaluate in vivo efficacy. The method presented here represents a unique and valuable approach to detecting hypoxic stress in living tissues which may prove useful to a variety of fields of biological research. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
Bone mineral accrual in 4- to 10-year-old precompetitive, recreational gymnasts: A 4-year longitudinal study
Authors: Erlandson Marta C , Kontulainen Saija A , Chilibeck Phil D , Arnold Catherine M , Baxter-Jones Adam DG
Published: February 2011

Competitive female gymnasts have greater bone mineral measures than nongymnasts. However, less is known about the effect of recreational and/or precompetitive gymnastics participation on bone development. The purpose of this study was to investigate whether the differences previously reported in the skeleton of competitive female gymnasts are also demonstrated in young children with a current or past participation history in recreational or precompetitive gymnastics. One hundred and sixty-three children (30 gymnasts, 61 ex-gymnasts, and 72 nongymnasts) between 4 and 6 years of age were recruited and measured annually for 4 years (not all participants were measured at every occasion). Total-body (TB), lumbar spine (LS), and femoral neck (FN) bone mineral content (BMC) were measured by dual-energy X-ray absorptiometry (DXA). Multilevel random-effects models were constructed and used to predict differences in TB, LS, and FN BMC between groups while controlling for differences in body size, physical activity, and diet. Gymnasts had 3% more TB and 7% more FN BMC than children participating in other recreational sports at year 4 (p < .05). No differences were found at the LS between groups, and there were no differences between ex-gymnasts' and nongymnasts' bone parameters (p > .05). These findings suggest that recreational and precompetitive gymnastics participation is associated with greater BMC. This is important because beginner gymnastics skills are attainable by most children and do not require a high level of training. Low-level gymnastics skills can be implemented easily into school physical education programs, potentially affecting skeletal health. © 2011 American Society for Bone and Mineral Research.
Content and method trends in the Journal of Community Psychology between 2003 and 2007
Authors: Graham Tanya M. , Ismail Tasneem
Published: February 2011

Ongoing inquiry into the characteristics of published work and its synergy with community psychology's core principles is an important reflexive endeavour in the field's continuing development. This study examined topic and method trends within the Journal of Community Psychology during a 5‐year period (January 2003–December 2007). Content analyses were conducted on published abstracts during this period (N=242). Most articles were empirical studies (61.2%) and most used a positivist methodology (53.7%). Samples mainly comprised adults and were mixed in terms of gender and ethnic/religious affiliation. The most frequent topics were mental health and mental illness (33.5%), sense of community and social support (24.4%), and dynamics of social exclusion (22.7%). A large proportion of special issues was also noted. These results illustrate contemporary trends in community psychology and suggest that critical and participatory methods as well as socially transformative epistemologies continue to be under‐represented within the field. © 2011 Wiley Periodicals, Inc.
Helping the helpers: an international training program for professionals providing social services for hiv‐positive children and their families in Southern Kazakhstan
Authors: Tartakovsky Eugene
Published: February 2011

Over one hundred children and some of their parents were infected with HIV in state hospitals in the Chimkent region in Southern Kazakhstan. After this tragedy, the Regional Department of Public Health organized social services for these families and asked the American Jewish Joint Distribution Committee (JDC) to provide them with training and supervision. Twelve seminars were conducted for the social workers in Chimkent over an 18‐month period. The JDC team also met with the local medical staff as well as with governmental and nongovernmental organizations to assess their needs and provide organizational support for the social services. This article presents an analysis of the psychosocial challenges associated with the mass HIV infection episode in Kazakhstan. The analysis is based on Hofstede's (2001) theory of cultural values, theories on cross‐cultural interaction (Cushner & Brislin, 1995), and principles of multicultural social work (Potocky‐Tripodi, 2002). The training program is described, and its results are discussed. General principles and practical recommendations for planning and implementing cross‐cultural international humanitarian programs in the field of HIV are suggested. © 2011 Wiley Periodicals, Inc.
Development of a scale to measure residents' psychological empowerment in Chinese Urban Community
Authors: Wang Qi , Chen Xiaojuan , Chen Yongsheng
Published: February 2011

The present study combined the literature analysis with the empirical study and proposed a Chinese local conception of psychological empowerment, which was defined as a process of personality‐oriented, self‐motivated, and proactive control with the aim of community members' citizen participation. Its basic dimension comprised an inclination to criticize based on change, the self‐evaluation for participatory competence, and the proactive control of participatory motivation. A Chinese Urban Citizens' Psychological Empowerment (CUCPE) Scale was developed and two pretest studies were conducted to refine the scale. The final investigation showed that the CUCPE Scale had good reliabilities and validities. © 2011 Wiley Periodicals, Inc.
Enzymatic activity of sperm proprotein convertase is important for mammalian fertilization
Authors: Iamsaard Sitthichai , Vanichviriyakit Rapeepun , Hommalai Greanggrai , Saewu Arpornrad , Srakaew Nopparat , Withyachumnarnkul Boonsirm , Basak Ajoy , Tanphaichitr Nongnuj
Published: January 2011

Proprotein convertase subtilisin/kexin 4 (PCSK4) is implicated for sperm fertilizing ability, based on studies using Pcsk4‐null mice. Herein we demonstrated proprotein convertase (PC) activity in intact sperm and acrosomal vesicles. To determine whether this activity was important for sperm fertilizing ability, a peptide inhibitor was designed based on PCSK4 prodomain sequence (proPC475–90), which contains its primary autocatalytic cleavage site. ProPC475–90 inhibited recombinant PCSK4's activity with a Ki value of 5.4 µM, and at 500 µM, it inhibited sperm PC activity almost completely. Treatment of sperm with proPC475–90 inhibited their egg fertilizing ability in a dose dependent manner. Correlation between sperm PC activity and fertilizing ability showed a high co‐efficient value (>0.9), indicating the importance of sperm PC activity in fertilization. In particular, sperm PC activity was important for capacitation and zona pellucida (ZP)‐induced acrosome reaction, since proPC475–90‐treated sperm showed markedly decreased rates in these two events. These results were opposite to those observed in Pcsk4‐null sperm, which contained higher PC activity than wild type sperm, possibly due to overcompensation by PCSK7, the other PCSK enzyme found in sperm. ADAM2 (45 kDa), a sperm plasma membrane protein, involved in sperm–egg plasma membrane interaction, was also processed into a smaller form (27 kDa) during capacitation at a much reduced level in proPC475–90‐treated sperm. This result suggested that ADAM2 may be a natural substrate of sperm PCSK4 and its cleavage by the enzyme during acrosome reaction may be relevant to the fertilization process. J. Cell. Physiol. 226: 2817–2826, 2011. © 2011 Wiley‐Liss, Inc.
Hyperosmotic stress strongly potentiates serum response factor (SRF)‐dependent transcriptional activity in ehrlich lettré ascites cells through a mechanism involving p38 mitogen‐activated protein kinase
Authors: Gorbatenko Andrej , Wiwel Maria , Klingberg Henrik , Nielsen Anni Bech , Kapus András , Pedersen Stine Falsig
Published: January 2011

Long‐term osmotic stress results in altered gene transcription, however, with the exception of the TonE/TonEBP system, the underlying mechanisms are poorly understood. We previously showed that upon osmotic shrinkage of Ehrlich Lettré Ascites (ELA) fibroblasts, the MEK1‐ERK1/2 pathway is transiently inhibited while p38 MAPK is activated, in turn impacting on cell survival (Pedersen et al., 2007, Cell Physiol Biochem 20: 735–750). Here, we show that downstream of these kinases, two transcription factors with major roles in control of cell proliferation and death, serum response factor (SRF) and cAMP response element‐binding protein (CREB) are differentially regulated in ELA cells. SRF Ser103 phosphorylation and SRF‐dependent transcriptional activity were strongly augmented 5–30 min and 24 h, respectively, after hyperosmotic stress (50% increase in extracellular ionic strength), in a p38 MAPK‐dependent manner. In contrast, CREB Ser133 was transiently dephosphorylated upon osmotic shrinkage. The ERK1/2 effector ribosomal S kinase (RSK) and the ERK1/2‐ and p38 MAPK effector mitogen‐ stress‐activated protein kinase 1 (MSK1) both phosphorylate CREB at Ser133. RSK and MSK1 were dephosphorylated within 5 min of shrinkage. MSK1 phosphorylation recovered within 30 min in a p38‐MAPK‐dependent manner. CREB was transiently dephosphorylated after shrinkage in a manner exacerbated by p38 MAPK inhibition or MSK1 knockdown, but unaffected by inhibition of RSK. In conclusion, in ELA cells, hyperosmotic stress activates SRF in a p38 MAPK‐dependent manner and transiently inactivates CREB, likely due to MSK1 inactivation. We suggest that these events contribute to shrinkage‐induced changes in gene transcription and death/survival balance. J. Cell. Physiol. 226: 2857–2868, 2011. © 2011 Wiley‐Liss, Inc.
The morphology of neoptile feathers: Ancestral state reconstruction and its phylogenetic implications
Authors: Foth Christian
Published: February 2011

Avian neoptile feathers are defined as the first feather generation, which covers the chick after hatching, and usually described as simple structures consisting of numerous downy barbs which are radially symmetrically arranged and come together in a short calamus. In contrast, in some birds (e.g., Anas platyrhynchos, Dromaius novaehollandiae) the neoptile feathers have a prominent rhachis, and therefore display clear bilateral symmetry. Because the symmetrical variety found in neoptile feathers is poorly understood, their morphology was studied in a more comprehensive and phylogenetic approach. Neoptile body feathers from over 22 bird species were investigated using light microscopy, SEM, and MicroCT. Characters such as an anterior–posterior axis, a central rhachis, medullary cells, and structure of the calamus wall were defined and mapped onto recent phylogenetic hypotheses for extant birds. It can be shown that bilaterally symmetric neoptile feathers (with a solid calamus wall) were already present in the stem lineage of crown‐group birds (Neornithes). In contrast, simple radially symmetric neoptile feathers (with a fragile calamus wall) are an apomorphic character complex for the clade Neoaves. The simple morphology of this feather type may be the result of a reduced period of development during embryogenesis. To date, embryogenesis of neoptile feathers from only a few bird species was used as a model to reconstruct feather evolution. Because this study shows that the morphology of neoptile feathers is more diverse and even shows a clear phylogenetic signal, it is necessary to expand the spectrum of “model organisms” to species with bilaterally symmetric neoptile feathers and compare differences in the frequency of feather development from a phylogenetic point of view. J. Morphol., 2011. © 2011 Wiley‐Liss, Inc.
Different spatial and temporal protein expressions of repulsive guidance molecule a and neogenin in the rat optic nerve after optic nerve crush with and without lens injury
Authors: Schnichels Sven , Heiduschka Peter , Julien Sylvie
Published: February 2011

The failure of lesioned mammalian CNS neurons to regenerate their axons remains a challenge. Evidence is emerging that repulsive proteins contribute to this failure. The repulsive guidance molecule A (RGMA) induces growth cone collapse in vitro, accumulates in the scar after spinal cord injury, and is up‐regulated in glaucoma. In this study, we evaluated the spatial and temporal localization pattern of RGMA and its receptor neogenin in the optic nerve after optic nerve crush (ONC) without or with lens injury (LI) at up to nine time points (6 hr to 20 days) postsurgery by performing immunohistochemistry and Western blots. We found RGMA at the crush site (CS) and in the developing scar of ONC rats at every time point investigated, whereas it was absent in the CS of ONC + LI rats. Independent of the model, many cells were RGMA+ in the ON: nerve fibers, blood vessels, astrocytes, oligodendrocytes, some microglia, some macrophages, and the sheath of the ON. Western blots showed a significantly lowered amount of RGMA in ONC + LI animals at 2, 4, and 6 days after crush compared with ONC animals. Furthermore, LI in sham‐operated animals showed an increase of RGMA in six of eight time points compared with the sham‐operated animals. Moreover, the effects of LI on the morphology of the ON were characterized at a level of detail never reported before. Our results show that RGMA is present and might contribute to the inhibitory environment in the ON, especially in and around the CS after ONC. © 2011 Wiley‐Liss, Inc.
Going lean drives business success at E‐Z‐GO
Authors: Stern Renée
Published: February 2011

What happens when an aging command‐and‐control vehicle manufacturer company facing diminishing business embarks on a course guided by lean manufacturing and business processes? For E‐Z‐GO of Augusta, Georgia, the result was a 200‐percent jump in profits in five years and systemwide improvement across all business functions that led the company to earn the first enterprise‐level Shingo Prize for Operational Excellence. This article details the continuous improvement roadmap that helped steer the organization on its journey of transformation, the bumps encountered along the way, and the widespread employee engagement designed to power E‐Z‐GO's efforts toward excellence in the future. © 2011 Wiley Periodicals, Inc.
Evaluating boards of directors of public‐sector companies in India: An empirical study of India's Navratna companies
Authors: Gupta S. L. , Hothi B. S. , Gupta Abhishek
Published: February 2011

The Navratna companies are a group of Indian public‐sector enterprises to which the Indian government has given a measure of financial and operational autonomy that allows them to make investments without the need to seek government approval. Evaluations of the operation of the board of directors of the Navratna companies are, at times, complex and confidential. This can make studying, analyzing, and evaluating them a difficult task. This research is based on a survey of the board of directors in nine Navratna companies: Oil and Natural Gas Corporation (ONGC), National Thermal Power Corporation (NTPC), Steel Authority of India Limited (SAIL), Indian Oil Corporation (IOC), Hindustan Petroleum Corporation Limited (HPCL), Bharat Petroleum Corporation Limited (BPCL), Gas Authority of India Limited (GAIL), Mahanagar Telephone Nigam Limited (MTNL), and Bharat Heavy Electricals Limited (BHEL). The results of our survey provide the basis for the evaluation of the operation of the board of directors of Navratna companies. They also indicate that the board of directors should not involve itself in the day‐to‐day functioning of the organization and that governance of such companies involves more than simply ensuring returns in the short term. © 2011 Wiley Periodicals, Inc.
Oxidative stress induces senescence in chondrocytes
Authors: Brandl Anita , Hartmann Andreas , Bechmann Volker , Graf Bernhard , Nerlich Michael , Angele Peter
Published: January 2011

Cellular senescence is a program activated during diverse situations of cell stress. Chondrocytes differ from other somatic cells as articular cartilage is an avascular tissue. The effects of oxidative stress on chondrocytes are still unknown. Our studies were to investigate into the proliferation potential, cytological features and the telomere linked stress response system of human osteoarthritic chondrocytes, subjected to acute or prolonged oxidant challenge with hydrogen peroxide. Telomere length was measured using the telomere restriction fragment assay, gene expression was determined by RT‐PCR. Sub‐lethal doses of oxidative stress induced cell‐cycle arrest, senescent‐morphological features and senescence‐associated β‐galactosidase positivity. Prolonged oxidative treatment had no effects on cell proliferation or morphology. Sub‐lethal and prolonged low doses of oxidative stress considerably accelerated telomere attrition. The effects of sub‐lethal oxidative stress regarding proliferation and telomere biology were more distinct in senescent cells. Acute oxidant insult caused up‐regulation of p21 expression to levels comparable to senescent cells. TRF2 protects telomere ends and showed elevated expression levels. SIRT1 and XRCC5 enable cells to cope with unfavorable growing conditions. Both were up‐regulated after oxidant insult, but expression levels decreased in aging cells. Taken together, oxidative stress considerably accelerated telomere shortening and cellular aging in chondrocytes. Senescent cells showed a reduced tolerance to oxidative stress. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 29: 1114–1120, 2011
Effect of organic amendments on uptake of selenium and biochemical grain composition of wheat and rape grown on seleniferous soils in northwestern India
Authors: Sharma Sucheta , Bansal Abhey , Dogra Ritu , Dhillon Surjit K. , Dhillon Karaj S.
Published: February 2011

Crops grown in seleniferous soil may accumulate selenium (Se) to levels considered highly toxic for animal and human consumption. Furthermore, higher Se content in plant tissues leads to considerable deterioration in product quality. Application of organic amendments plays an important role in improving soil physical, chemical, and biological conditions and influencing nutrient availability. A field trial was conducted to evaluate the effect of organic amendments, namely poultry manure (PM), sugar cane press mud (SCPM), and farmyard manure (FYM), on Se uptake and grain quality of wheat and oilseed rape grown on a seleniferous soil in Punjab, India. Selenium accumulation by wheat and oilseed rape grains decreased significantly (75%–95%) with the application of PM and SCPM, while FYM application resulted in a significant decrease (23%) only in case of wheat grains. The amount of Se associated with seed proteins varied in proportion to its uptake under different treatments. Quality of wheat grains improved considerably with respect to total soluble sugars, reducing sugars, starch, lipids, and sulfur concentrations only after application of SCPM and PM. Treating a Se‐contaminated soil with organic amendments significantly increased the oil concentration and changed the proportion of various fatty acids in rape grains. It is concluded that applying organic amendments to Se‐contaminated soils can alleviate the deleterious effects of Se and restore the nutritional quality of grains.
Orthogonal array design for the optimization of ionic liquid‐based dispersive liquid–liquid microextraction of benzophenone‐type UV filters
Authors: Ye Lei , Liu Juanjuan , Yang Xin , Peng Yan , Xu Li
Published: February 2011

In the present study, dispersive liquid–liquid microextraction (DLLME) using an ionic liquid (IL) as the extractant was successfully developed to extract four benzophenone‐type UV filters from the different water matrices. Orthogonal array experimental design (OAD), based on five factors and four levels (L16(45)), was employed to optimize IL‐dispersive liquid–liquid microextraction procedure. The five factors included pH of sample solution, the volume of IL and methanol addition, extraction time and the amount of salt added. The optimal extraction condition was as follows. Sample solution was at a pH of 2.63 in the presence of 60 mg/mL sodium chloride; 30 μL IL and 15 μL methanol were used as extractant and disperser solvent, respectively; extraction was achieved by vortexing for 4 min. Using high‐performance liquid chromatography‐UV analysis, the limits of detection of the target analytes ranged between 1.9 and 6.4 ng/mL. The linear ranges were between 10 or 20 ng/mL and 1000 ng/mL. This procedure afforded a convenient, fast and cost‐saving operation with high extraction efficiency for the model analytes. Spiked waters from two rivers and one lake were examined by the developed method. For the swimming pool water, the standard addition method was employed to determine the actual concentrations of the UV filters.
Assessment of soil erosion in karst regions of Havana, Cuba
Authors: Febles‐González J.M. , Vega‐Carreño M.B. , Tolón‐Becerra A. , Lastra‐Bravo X.
Published: January 2011

Only recently have erosion models begun to be used in research work in Cuba, specifically the USLE and the thematic cartography of factors in a GIS framework without using a specific model. It therefore becomes necessary to include simulation models for karst regions that make possible an integral assessment of the specific types of soil erosion in those environments and take into consideration the effects of climate change in soil management systems. Morphometric analysis of karst doline absorption forms in regions of La Habana Province in 1986, 1997, and 2009 allowed the characterisation and application of the Morgan Morgan Finney (MMF) conceptual empirical erosion model in the Country for the first time. The results showed previously unreported losses of 12·3–13·7 t of soil ha −1 y−1, which surpasses the permissible erosion threshold. Furthermore, it clearly shows the unsustainable trend of Red Ferralitic and Ferrasol Rhodic (World Reference Base) soils use. The model applied considered the effects of extreme rainfall events associated with climate change in recent years. The results found have led to strategies for coping with future climate change in each scenario and have made it possible to evaluate the consequences. Copyright © 2011 John Wiley & Sons, Ltd.
Classical and quantum control of electrons using the carrier‐envelope phase of strong laser fields
Authors: Abel M. , Neumark D.M. , Leone S.R. , Pfeifer T.
Published: February 2011

Electrons are among the lightest quantum particles in nature, yet they are of paramount importance in any kind of chemical reaction as they are the essence of molecular bonds. For several years, laser fields have been used towards the final goal of controlling chemical reaction dynamics. While early experiments focused mainly on the control of the internuclear wavefunction of rather heavy molecules, advances in short‐pulse laser technology now allow the control of lighter molecules all the way down to hydrogen and even the direct control of electrons and their quantum wavefunctions. In this context, the stabilization and control of the carrier‐envelope phase (CEP) of laser pulses has been one of the crucial technological advances that set off a revolution in ultrafast laser science. The authors review and summarize some of the past and current experimental achievements and theoretical ideas on CEP laser control of electrons. It will become clear that in some cases, depending on the control scenario, electrons can be considered to behave as classical particles and the control of their trajectories follow the laws of classical Newtonian mechanics while in other cases, the quantum nature of electrons is directly exploited to steer electron dynamics by means of quantum interference.
Pattern of bacterial and fungal infections in the first 3 months after pediatric living donor liver transplantation: An 11-year single-center experience
Authors: Nafady-Hego Hanaa , Elgendy Hamed , Moghazy Walid El , Fukuda Kazuhiko , Uemoto Shinji
Published: January 2011

Infection after pediatric living donor liver transplantation (LDLT) is a major cause of morbidity and mortality. Here, we sought to determine the incidence, timing, location, and risk factors for bacterial and fungal infections. We retrospectively investigated infection for 3 postoperative months in 345 consecutive pediatric patients (56.2% were females) who underwent primary LDLT at Kyoto University Hospital, Japan. A total of 179 patients (51.9%) developed at least 1 bacterial and/or fungal infection episode, with an infection rate of 2.5 per patient. The predominant infection site was the surgical site (52%). Most of the bacterial and fungal infection occurred within the first month. Enterococcus species followed by multidrug-resistant Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus were the predominant bacterial pathogens. All fungal isolates were Candida species. Prolonged preoperative hospital stay more than 7 days (P = 0.025) and bile leak (P = 0.047) were independent predictors of bacterial infection. Preoperative ascites (P = 0.009) and prolonged insertion of intravascular catheters (P = 0.001) independently predicted fungal infections. Bacterial and fungal infections were responsible for 42.9% of the causes of death in our study. To avoid bacterial and fungal infections after LDLT, broader-spectrum prophylaxis to cover the range of organisms seen in these infections should be considered as a more favorable treatment regimen to prevent prophylaxis failure, especially for patients with a preoperative hospital stay more than 7 days or operative complications in the form of a bile leak. Early drain removal and prophylactic antifungal drugs should be considered for patients with preoperative ascites. Cooperation between attending physicians and infectious disease physicians can improve the outcome of patients after LDLT. Liver Transpl 17:976–984, 2011. © 2011 AASLD.
Hot dip galvanizing behavior of advanced high strength steel
Authors: Li F. , Liu H. , Shi W. , Liu R. , Li L.
Published: February 2011

This work studied the hot dip galvanizing behavior of three advanced high strength steels annealed under different protective atmospheres. The coating quality, surface oxides, and the mechanical property of steel matrix were examined. The experimental results show that annealing atmosphere can influence the galvanizability and thermodynamics calculation can predict the surface selective oxidation. It was shown for the first time in this work that annealing atmosphere may also influence the mechanical property of the steel matrix.
Transformation/dissolution studies on the release of iron and chromium from particles of alloys compared with their pure metals and selected metal oxides
Authors: Hedberg Y. , Wallinder I. Odnevall
Published: February 2011

Transformation/dissolution (T/D) data for different Cr‐ and Fe‐based alloys (a FeCr alloy, stainless steel AISI 316L, an alloy side product (SP) from stainless steel production) compared with their pure metals (Cr, Fe) and selected metal oxides (Cr2O3, Fe3O4) was generated and is used throughout the entire REACH assessment documentation of chromium metal and ferrochromium alloys to derive conclusions regarding their acute and chronic ecotoxicity hazard classification.

Short and long term tests were conducted to assess data for acute and chronic aquatic toxicity following the recognized standardized T/D protocol. Tests were performed in media of different pH (pH 6.0 and pH 8.0), time periods, and solution composition, also investigating the effect of different experimental parameters.

Generated data elucidates the complexity of the metal release process and its dependence on many interacting material‐, surface‐, and experimental factors as well as on the chemistry of the metal–water system being metal species specific. It is evident that the extent of metal release cannot be predicted by either the bulk or the surface composition, and that metal speciation measurements of released metals are essential to assess aquatic toxicity induced by metal/alloy particles. Observed released Fe and Cr concentrations were significantly lower than reported acute and chronic ecotoxicological endpoints.
The effect of absorbed hydrogen on the corrosion behavior of sintered NdFeB magnet
Authors: Yang H. , Mao S. , Song Z.
Published: February 2011

The absorption of hydrogen by NdFeB magnet has been investigated by using the electrochemical charging technique at constant cathodic current density Ic ranging from 0 to 4 mA/cm2. Open circuit potential measurements (OCP) and polarization curves were carried out to study the corrosion behavior of the charged NdFeB magnet in 0.01 mol/L NaCl solution. The results showed that hydrogen had a strong influence on the corrosion of NdFeB magnet. The open circuit potential became gradually negative due to the hydrogen incorporation into the NdFeB magnet. The corrosion resistance was reduced gradually with the increasing cathodic current density Ic. The surface structure and the morphology of the charged NdFeB magnet were examined by XRD and SEM. The results revealed that the effect of the absorbed hydrogen focused mostly on accelerating the exfoliation corrosion of Nd2Fe14B matrix grain.
Preparation and characterization of inorganic and organic coatings on AZ91D magnesium alloy with electroless plating pretreatment
Authors: Zhang S. Y. , Li Q. , Yang X. K. , Zhang H. X. , Wang S. Y. , Liu F.
Published: February 2011

In this paper, a protective coating scheme was applied for the corrosion protection of AZ91D magnesium alloy. Electroless Ni coating (EN coating) as bottom layer, electrodeposited Ni coating (ENN coating), and silane‐based coating (ENS coating) as top layer, respectively, were successfully prepared on AZ91D magnesium alloy by combination techniques. Scanning electron microscopy and X‐ray diffraction were employed to investigate the surface and phase structure of coatings, respectively. The electrochemical corrosion behaviors of coatings in neutral 3.5 wt% NaCl solution were evaluated by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques. The corrosion testing showed that the three kinds of coatings all could provide corrosion protection for AZ91D magnesium alloy to a certain extent, and the corrosion resistance of ENN and ENS was superior to EN. In order to further study the corrosion protection properties of ENN and ENS, a comparative investigation on the evolution of EIS of ENN and ENS was carried out by dint of immersion test in neutral 3.5 wt% NaCl solution. The results indicated that, compared with ENN, the ENS could provide longer corrosion protection for AZ91D magnesium alloy. It is significant to determine the barrier effect of each coating, which could provide reference for industry applications.
A zinc/silicon dioxide composite film: Fabrication and anti‐corrosion characterization
Authors: Lin Z. F. , Zhang D. , Wang Y. , Wang P.
Published: February 2011

A zinc/silicon dioxide composite film has been electrodeposited on carbon steel surface via adding tetraethylorthosilicate (TEOS) in zinc nitrate solution. The advantage of this method is that the metal/inorganic composite film can be fabricated without adding solid particles in solution. Polarization curve results showed that the composite film obtained at a TEOS concentration of 0.012 M had the best corrosion resistance. Electrochemical impedance spectroscopy results indicated that this film had a corrosion protection effect in 3.5 wt% sodium chloride solution for hundreds of hours. This kind of composite film can be potentially applied as anti‐corrosion coating for metal corrosion protection.
Magnetic properties of multi‐walled carbon nanotubes modified with cobalt
Authors: Grechnev G.E. , Desnenko V.A. , Fedorchenko A.V. , Panfilov A.S. , Prylutskyy Y.I. , Grybova M.I. , Matzui L.Y. , Ritter U. , Scharff P. , Kolesnichenko Y.A.
Published: February 2011

Magnetic properties of multi‐walled carbon nanotubes (MWCNT) modified with cobalt were studied in detail in the temperature range (4.2–290) K. MWCNT which encapsulate Co nanoparticles were obtained using CVD methods. The low temperature SQUID magnetization measurements were supplemented by structural investigations with thermogravimetric analysis, HRTEM and SEM.

Die magnetischen Eigenschaften von mit Kobalt‐modifizierten mehrwandigen Kohlenstoffnanoröhren (MWCNT) wurden im Detail in einem Temperaturbereich von 4,2 bis 290 K untersucht. Die MWCNT mit Kobalteinschlüssen wurden durch CVD Methoden erhalten. Die bei niedrigen Temperaturen gemessenen SQUID Magnetisierungen konnten durch Strukturuntersuchungen mit thermogravimetrischen Analysen und Rasterelektronenmessungen ergänzt werden.
Variation of defect spectra in Si ionizing radiation detectors depending on irradiation
Authors: Kalendra V. , Kažukauskas V. , Vainorius N. , Vaitkus J. V. , Bozhko V.
Published: February 2011

The defect properties of Si ionizing radiation detectors were investigated depending on the irradiation by high energy neutrons. The investigations were performed in the framework of WODEAN project of CERN‐RD50 collaboration. The p+‐n‐n+ samples were irradiated with the fluencies 1·1013 to 1·1016 n/cm2. The photoconductivity spectra indicated that upon irradiation deep levels below the middle of the band gap were created. Their activation energies were 0.49–0.52 eV, 0.77–0.81 eV, 0.88–0.91 eV, and 1.02–1.11 eV. The effective densities of these levels were depending on the fluencies and on the isochronal thermal treatments at low temperatures. The variations of the defect level population induced by annealing have been compared with the steady state lifetimes and photoconductivity decay constants.

Die Defekteigenschaften von Si‐Detektoren für ionisierende Strahlung wurden in Abhängigkeit von der Bestrahlung durch hochenergetische Neutronen untersucht. Die Untersuchungen wurden im Rahmen des Projekts WODEAN der CERN‐RD50 Kollaboration durchgeführt. Die p+‐n‐n+ Proben wurden mit Flussdichten von 1·1013 bis 1·1016 n/cm2 bestrahlt. Die Photoleitfähigkeitsspektren ergaben, dass bei der Bestrahlung tiefe Niveaus unterhalb der Mitte der Bandlücke erzeugt wurden. Die Aktivierungsenergien dieser Niveaus betragen 0,49 bis 0,52 eV, 0,77 bis 0,81 eV, 0,88 bis 0,91 eV und 1,02 bis 1,11 eV. Die effektiven Dichten dieser Niveaus hängen sowohl von der Flussdichte als auch von der isochron thermischen Behandlung bei niedrigen Temperaturen ab. Die Variation der Besetzung des Niveaus durch Erhitzen wurde mit den Gleichgewicht‐Lebensdauern und den Photoleitfähigkeit‐Abbaukonstanten verglichen.
A comparative STM‐investigation of monolayers of n‐alkanes and arachidic acid on the liquid tetradecane‐graphite interface
Authors: Senenko A.I. , Stryzheus. D.V. , Marchenko A.A. , Naumovets A.G.
Published: February 2011

Highly ordered monolayer films of an n‐alkane and arachidic acid were deposited on graphite surface from their solutions in n‐tetradecane, and their molecular structure was investigated by scanning tunneling microscopy. Close‐packed lamella‐like structures with long range order were observed. In alkane monolayers, each lamella is composed by single molecules, while in the case of acid, lamellas consist of dimers formed by acid molecules due to interaction between their carboxylic groups, probably via hydrogen bonds. An increased brightness of carboxyl head in each fifth acid molecule was observed, which is attributed to nonequivalent positions of acid molecules with respect to the substrate carbon atoms.

Hochgeordnete Monoschichtfilme von einem n‐Alkan und von Arachidonsäure wurden auf einer Graphitoberfläche aus Lösungen in n‐Tetradecan abgeschieden und ihre Molekularstruktur wurde untersucht. Beobachtet wurden dichtgepackte lamellenartigen Strukturen mit weitreichender Ordnung. In Alkan‐Monoschichten besteht jede Lamelle aus einzelnen Molekülen, während bei Säuren die Lamellen aus Dimerenbestehen, die aus Säuremolekülen über die Wechselwirkung zwischen ihren Carboxylgruppen gebildet wurden, wahrscheinlich durch Wasserstoffbrückenbindung. Eine verstärkte Helligkeit des Carboxylat‐Endes wurde in jedem fünften Säuremolekül beobachtet, was für nichtäquivalente Position von Säuremolekülen in Bezug auf einer Schichtunterlage aus Kohlenstoffatomen typisch ist.
Effect of flavonoids on basal and insulin‐stimulated 2‐deoxyglucose uptake in adipocytes
Authors: Claussnitzer Melina , Skurk Thomas , Hauner Hans , Daniel Hannelore , Rist Manuela J.
Published: January 2011

Scope: The adipose tissue is a major site of insulin action and contributes substantially to energy homeostasis. Insulin increases the extraction of glucose from circulation into adipose tissue by recruiting the glucose transporter GLUT4 to the plasma membrane. It has been proposed that dietary flavonoids may interfere with glucose transport processes.

Methods and results: We have used murine 3T3‐L1 adipocytes and isolated mature human adipocytes to assess the interaction of selected flavonoids with glucose uptake, both in the basal state and after insulin stimulation. Kinetic characterization of 2‐deoxyglucose uptake in the basal state revealed in both cell types an apparent Km of around 8 mM with no change in affinity but a significant increase in maximal influx in the presence of insulin. A screening of representative flavonoids of different structural classes revealed the flavanone naringenin and the isoflavone daidzein to affect glucose transport significantly with half‐maximal inhibition at concentrations of around 60–80 μM for basal and 70–110 μM for insulin‐stimulated glucose uptake in both 3T3‐L1 adipocytes and mature human adipocytes.

Conclusion: Considering attainable plasma concentrations of flavonoids in vivo, we assume that even under physiological conditions naringenin and daidzein could impair glucose removal from plasma, which may pose a risk to patients with diabetes mellitus.
Stabilization of small heterodimer partner mRNA by grape seed procyanidins extract in cultured hepatocytes
Authors: Inoue Jun , Tanaka Minako , Nanmoku Manami , Yashiro Takuya , Sato Ryuichiro
Published: January 2011

Scope: Consumption of dietary grape seed procyanidins extract (GSPE) has improved the plasma lipid profile in humans and experimental animals. The effect of GSPE on the reduction of the postprandial plasma triglyceride (TG) levels has been attributed to the activation of the small heterodimer partner (SHP). GSPE increases SHP gene expression in rat liver and the TG‐lowering effect of GSPE is abolished in SHP‐deficient mice. However, the mechanism by which GSPE increases SHP mRNA levels remains unclear. This study addressed the effect of GSPE on SHP mRNA stability.

Methods and results: The present study shows for the first time that SHP mRNA is rapidly degraded, as measured by actinomycin D‐based mRNA chase experiments, and GSPE transiently stabilizes SHP mRNA in HepG2 cells. This degradative effect was completely abolished with 2 h of prolonged treatment with GSPE. However, treatment of fresh HepG2 cells with a pretreated GSPE‐containing medium also stabilized SHP mRNA, indicating that GSPE inactivation is not responsible for the transient effects that GSPE has on SHP mRNA stability.

Conclusion: SHP expression is intricately controlled by mRNA stabilization, which is transiently increased by GSPE, along with at the transcriptional and posttranslational levels.