bluuebunny/crossref_metadata_2025 huggingface dataset:
Acts and procedures concerning procedure-related deaths in South Africa
Authors: Jansen van Vuuren Stefan
Published: June 2013

Background: The act regarding procedure-related deaths in South Africa has changed recently (in 2007) and comprises a more encompassing description of possible procedure-related deaths. It subsequently includes unnatural deaths in cases where the patient died during aprocedure, or as a result of a procedure, or where it can be shown that any aspect of such a procedure has been a contributory cause. The act does not qualify the ‘procedure’ and by definition includes all procedures, including anaesthesia.Objective: The objective of this article is to bring awareness to general practitioners regarding the legal requirements when dealing with suspected procedure-related deaths, and to outline some of the regulations pertaining to the management of such incidents.Methods: A thorough study, interpretation and clarification of the new legislature on procedure-related deaths were performed.Discussion: The onus of deciding which procedure-related deaths are unnatural has been removed from the doctor as the new act includes all such deaths. Certain aspects of the acts remain difficult to interpret and consultation with the appointed forensic pathologist in your area is still essential in all cases of a suspected procedure-related death. Healthcare workers should acquaint themselves with all these regulations and acts that are readily available in the Government Gazette.
Use of Ber-EP4 and Epithelial Specific Antigen to Differentiate Clinical Simulators of Basal Cell Carcinoma
Authors: Dasgeb Bahar , Mohammadi Tarana M , Mehregan Darius R
Published: June 2013

EpCam is a transmembrane epithelial adhesion molecule present on all non-squamous epithelial cells. It is often overexpressed in certain carcinomas, such as breast and colon, and in dermatology, eg, basal cell carcinoma (BCC). Various monoclonal antibodies have been used to detect EpCam, including BerEP4 and epithelial specific antigen. We compared anti-EpCam clones, BerEP4, and epithelial specific antigen clone VU-1D9. One hundred and twelve lesions were stained with both antibodies. All basal cell carcinomas stained uniformly and strongly positive with both antibodies. Diffuse positive staining was also seen in all trichoepitheliomas and merkel cell carcinomas. Focal positive staining was seen in squamous cell carcinoma and benign sebaceous neoplasms. Clone VU-1D9 was more likely to produce focal positive staining as compared to BerEP4. This focal positive staining of sebaceous neoplasms and squamous cell carcinomas is a potential diagnostic pitfall.
Recruiting Trainees for a Global Health Research Workforce: The National Institutes of Health Fogarty International Clinical Research Scholars Program Selection Process
Authors: Heimburger Douglas C. , Warner Tokesha L. , Carothers Catherine Lem , Blevins Meridith , Thomas Yolanda , Gardner Pierce , Primack Aron , Vermund Sten H.
Published: June 2013

Between 2004 and 2012, the National Institutes of Health Fogarty International Clinical Research Scholars (FICRS) Program provided 1-year mentored research training at low- and middle-income country sites for American and international health science doctoral students. We describe the centralized application process, US applicant characteristics, and predictors of selection/enrollment. FICRS received 1,084 applicants representing many health professions and biomedical disciplines at 132 US academic institutions; 219 students from 72 institutions were accepted and enrolled. Medical/osteopathic students comprised 88.9% of applicants and 85.8% of enrollees. Applicants from institutions with higher applicant numbers were two times as likely to be selected. In 2012, FICRS was decentralized among 20 institutions in five consortia (Global Health Fellows), with autonomous selection processes that emphasize post-doctoral trainees. If academia, government, or charitable foundations offer future opportunities to health professions students for international research, the FICRS experience predicts that they can attract substantial numbers of motivated trainees from diverse backgrounds.
Transplacental Transmission of Cutaneous Leishmania mexicana Strain in BALB/c Mice
Authors: Avila-García Miroslava , Mancilla-Ramírez Javier , Segura-Cervantes Enrique , Farfan-Labonne Blanca , Ramírez-Ramírez Alicia , Galindo-Sevilla Norma
Published: June 2013

The vertical transmission of leishmaniasis has been reported in species that cause visceral leishmaniasis. However, this condition has scarcely been documented in species that cause cutaneous leishmaniasis. The aim of this study was to determine experimentally whether L. mexicana is transmitted vertically. A control group of BALB/c mice and a group infected with L. mexicana were mated, the gestation was monitored, and females were killed before delivery. Four resorptions (P = 0.023) and eight fetal deaths (P = 0.010) were observed in the infected female group; furthermore, the offspring body weight of the infected group was lower than the body weight of the healthy group (P = 0.009). DNA amplification by polymerase chain reaction (PCR) revealed that all placentas and maternal spleens as well as 39 of 110 fetal spleens obtained from the offspring of infected mothers tested positive for Leishmania. In conclusion, L. mexicana is transmitted transplacentally and causes fetal death, resorption, and reduction in offspring body weight.
Clinical and Epidemiologic Profile of Cutaneous Leishmaniasis in Colombian Children: Considerations for Local Treatment
Authors: Blanco Victor M. , Cossio Alexandra , Martinez Javier D. , Saravia Nancy Gore
Published: June 2013

Treatment alternatives have seldom been evaluated in children with cutaneous leishmaniasis (CL). We examine the clinical/epidemiological profile of children with CL considering international guidelines for local treatment. Descriptive analyses were conducted using International Center for Medical Research and Training (CIDEIM) case reports of parasitologically diagnosed patients ≤ 14 years of age from 2004 to 2010. Eligibility for local treatment based on World Health Organization/Pan American Health Organization (WHO/PAHO) criteria was determined. Among 380 children, 90% presented lesions of < 3 months duration, 54% presented single lesions < 30 mm in diameter, and 45% were ≤ 5 years old. Lesions on the head and neck were more frequent among children 0–5 years, and lesions below the head/neck were more frequent among 11- to 14-year-old children (P = 0.004). Using PAHO and WHO criteria, 26% and 53% of children, respectively, were eligible for local treatment. Recommended local treatments for New World CL have potential but limited applicability in children. Individual risk–benefit assessment and effectiveness data in children may increase eligibility.
Molecular Evidence of Trichostrongylus colubriformis and Trichostrongylus axei Infections in Humans from Thailand and Lao PDR
Authors: Phosuk Issarapong , Intapan Pewpan M. , Sanpool Oranuch , Janwan Penchom , Thanchomnang Tongjit , Sawanyawisuth Kittisak , Morakote Nimit , Maleewong Wanchai
Published: June 2013

Human trichostrongylosis has been reported in Thailand. Recent reports in Lao People's Democratic Republic concerning species identification urged us to investigate species distribution in Thailand. We report eight human cases in Thailand and Lao People's Democratic Republic that were found to be infected by Trichostrongylus colubriformis and T. axei identified and confirmed by molecular techniques. This evidence is the first molecular evidence of human T. colubriformis and T. axei infection in Thailand. Infection by these two species was apparently epidemic in these areas. It is necessary to proceed with more comprehensive veterinary and epidemiologic studies to enable the practical prevention and control of this parasitic zoonosis.
Economic Burden of Bacteremic Melioidosis in Eastern and Northeastern, Thailand
Authors: Bhengsri Saithip , Lertiendumrong Jongkol , Baggett Henry C. , Thamthitiwat Somsak , Chierakul Wirongrong , Tisayaticom Kanjana , Tanwisaid Kittisak , Chantra Somrak , Kaewkungwal Jaranit
Published: June 2013

Melioidosis is among the most common causes of septicemia in Thailand, but data on economic burden are limited. We describe the economic impact of bacteremic melioidosis hospitalizations in two Thailand provinces during 2006–2008. Costs are presented in US dollars ($1 = 30.49 Thai Baht). The average annual incidence of bacteremic melioidosis cases per 100,000 persons in Sa Kaeo and Nakhon Phanom was 4.6 and 14.4, respectively. The annual cost of bacteremic melioidosis hospitalizations from the societal perspective, including direct and indirect costs, was $152,159 in Sa Kaeo and $465,303 in Nakhon Phanom. The average cost per fatal case was $14,182 and $14,858 in Sa Kaeo and Nakhon Phanom, respectively. In addition to the high morbidity and mortality, the substantial economic burden of melioidosis further supports the need for investments to identify improved prevention and control strategies for melioidosis.
Numerical modelling of methyl iodide in the eastern tropical Atlantic
Authors: Stemmler I. , Rothe M. , Hense I. , Hepach H.
Published: June 2013

Abstract. Methyl iodide (CH3I) is a volatile organic halogen compound that contributes significantly to the transport of iodine from the ocean to the atmosphere, where it plays an important role in tropospheric chemistry. CH3I is naturally produced and occurs in the global ocean. The processes involved in the formation of CH3I, however, are not fully understood. In fact, there is an ongoing debate whether production by phytoplankton or photochemical degradation of organic matter is the main source term. Here, both the biological and photochemical production mechanisms are considered in a biogeochemical module that is coupled to a one-dimensional water column model for the eastern tropical Atlantic. The model is able to reproduce observed subsurface maxima of CH3I concentrations. But, the dominating source process cannot be clearly identified as subsurface maxima can occur due to both direct biological and photochemical production. However, good agreement between the observed and simulated difference between surface and subsurface methyl iodide concentrations is achieved only when direct biological production is taken into account. Production rates for the biological CH3I source that were derived from published laboratory studies are shown to be inappropriate for explaining CH3I concentrations in the eastern tropical Atlantic.
Gait Analysis in Anorexia and Bulimia Nervosa
Authors: Cimolin Veronica , Galli Manuela , Vismara Luca , Vimercati Sara Laura , Precilios Helmer , Cattani Laila , De Souza Shirley Fabris , Petroni Maria Letizia , Capodaglio Paolo
Published: June 2013

Purpose

Anorexia (AN) and bulimia nervosa (BN) are two common eating disorders, which appear to share some reduced motor capacities, such as a reduced balance. The presence and the extent of other motor disorders have not been investigated in a comprehensive way. The aim of this study was to quantify gait pattern in AN and BN individuals in order to ascertain possible differences from the normality range and provide novel data for developing some evidence-based rehabilitation strategies.

Methods

Nineteen AN patients (age 30.16+9.73) and 20 BN patients (age 26.8+8.41) were assessed with quantitative 3d computerized Gait Analysis. Results were compared with a group of healthy controls (CG; 30.7+5.6).

Results

AN and BN patients were characterized by different gait strategies compared to CG. Spatio-temporal parameters indicated shorter step length, with AN showing the shortest values. AN walked slower than BN and CG. As for kinematics, AN and BN showed a nonphysiologic pattern at pelvis and hip level on the sagittal and frontal plane, with BN yielding the most abnormal values. Both AN and BN patients were characterized by high ankle plantar flexion capacity at toe-off when compared to CG. As for ankle kinetics, both AN and BN showed physiologic patterns. Stiffness at hip level was close to CG in both pathologic groups; at the ankle level, stiffness was significantly decreased in both groups, with AN displaying lower values.

Conclusions

Both AN and BN were characterized by an altered gait pattern compared to CG. Biomechanical differences were evident mainly at pelvis and hip level. Loss of lean mass may lead to musculoskeletal adaptation, ultimately causing alterations in the gait pattern.
Stakeholder Happiness Enhancement: A Neo-Utilitarian Objective for the Modern Corporation
Authors: Jones Thomas M. , Felps Will
Published: June 2013

Employing utilitarian criteria, Jones and Felps, in “Shareholder Wealth Maximization and Social Welfare: A Utilitarian Critique” (Business Ethics Quarterly23[2]: 207–38), examined the sequential logic leading from shareholder wealth maximization to maximal social welfare and uncovered several serious empirical and conceptual shortcomings. After rendering shareholder wealth maximization seriously compromised as an objective for corporate operations, they provided a set of criteria regarding what a replacement corporate objective would look like, but do not offer a specific alternative. In this article, we draw on neo-utilitarian thought to advance a refined version of normative stakeholder theory that we believe addresses a major remaining criticism of extant versions, their lack of specificity. More particularly, we provide a single-valued objective function for the corporation—stakeholder happiness enhancement—that would allow managers to make principled choices between/among policy options when stakeholder interests conflict.
Organomodified Silicone Elastomer (OMSE) for Next Generation Personal Care Products
Authors: Vaidya Ashish Anant , Balu K. , Chavan Mohan Vijaykumar , Ghosh Nilmoni , Kumar Amit
Published: June 2013

Personal care (PC) products containing commercial silicone elastomer (SE) blends offer superior sensory, due to their silky and non-greasy characteristics. These products contain functional organic actives; namely sunscreens, antibacterial agents and dyes. The functional performance of the PC products is determined by the extent of deposition of the actives on the skin or hair. However, this performance is limited due to incompatibility of organic actives with the silicone elastomer (SE) blend. This review described recent development of organomodified silicone elastomers (OMSE) for enhanced compatibility and superior deposition of actives on the skin or hair. OMSEs contain covalently linked functional actives to the cross-polymeric silicone backbone. OMSE were synthesized by reacting alkenyl functional derivatives of avobenzone, benzylidene malonate, curcumin or hydroxyanthraquinone, suitable crosslinker, solubilizing (e.g. CnH2n i.e. alkyl) / emulsifying agents (e.g. polyether) with the poly(dimethyl)-co-(methylhydrogen)siloxane copolymer in the presence of platinum catalyst. OMSE showed superior functional performance due to uniform molecular distribution of sunscreen / dye molecules on the substrate surface. Covalently attached sunscreen / dye molecules on the cross-polymeric silicone backbone would show enhanced safety profile due to negligible possibility of penetration through skin.
Structural, Morphological and Tensile Study of CdS/Polystyrene (PS) Nanocomposite
Authors: Mathur Vishal , Sharma Kananbala
Published: June 2013

Thick film of CdS/Polystyrene (PS) nanocomposite was synthesized by dispersing nanofiller particles of CdS in PS matrix. The nanostructure of the CdS particles has been ascertained through X-ray Diffraction (XRD) and Transmission Electron Microscopy (TEM). Small angle x-ray scattering analysis has been performed in order to ascertain nanocomposite character of the PS/CdS sample. Scanning Electron Microscopy (SEM) analyses of these samples have been carried out to establish the surface morphology. The Tensile studies of prepared samples have been ascertained through Dynamic Mechanical Analyzer (DMA). This study reveals that the young’s modulus and the toughness of the material are greatly influenced by the existence of interfacial energetic interaction between dispersed CdS nanofiller particles and matrix of PS.
Taking Space to Grow Food and Community: Urban Agriculture and Guerrilla Gardening in Vancouver
Authors: Black Rachel E.
Published: June 2013

City planners and citizens often see gardens as spaces for urban beautification projects. However, urban agriculture and growing food in cities is becoming an increasingly accepted use of public green spaces. This article examines how gardeners and the City of Vancouver negotiate space while trying to create green cities, greater awareness of food security issues, and community in urban environments. These gardens show how local discourses of health, environment, and food production are created through this process of appropriating urban spaces for horticultural activities. Based on ethnographic fieldwork, this paper explores the development of spontaneous and grassroots urban agriculture movements in Vancouver. This research was carried out from 2006 to 2008 while the city was preparing for the 2010 Winter Olympic Games. At this time, Vancouverites, local officials, and Games organizers were concerned about putting on a “green” Games. As the media spotlight began to fall on Vancouver, urban agriculture became a very public demonstration of the city’s environmental awareness. This article looks at how, at a particular historic moment, grassroots gardening movements gained mainstream acceptance and played a role in constructing the city’s image as an environmentally aware urban place with a high standard of living.
Eskimo Ice Cream and Kraft Dinner Goulash: The Cultural Geographies of Food in Three Cookbooks from the Northwest Territories (NWT), Canada
Authors: Christensen Julia
Published: June 2013

In this article, I explore three Northwest Territories (NWT) cookbooks from the 1960s. The first cookbook, a fundraiser for the Anglican Church in Inuvik, demonstrates the significance of traditional Indigenous food preparations, as well as the integration of imported recipes, adapted to draw resourcefully on northern store provisions of that time. Most, if not all, of the recipes are provided by Indigenous women. The second, published by the Daughters of the Midnight Sun in Yellowknife, is a hospital fundraiser that offers a different perspective - that of an emerging population of newcomers from elsewhere in Canada and the world. While the recipes attest to the diverse roots of settlers in a growing community, they also tell a story of exclusion: one cannot help but wonder at the lack of Indigenous representation among the recipe writers, in a community built within the traditional homelands of the Yellowknives Dene First Nation. The third, published by the Department of Indian Affairs and Northern Development, offers tips to northern “wilderness wives” on nutrition along with recipes that are often out of touch with the availability of certain ingredients in northern communities. Drawing on feminist and postcolonial theory, I critique these cookbooks: analyzing both the recipes and the positionalities of their writers, to explore how the north was imagined by three different, often opposing, perspectives; and offering insight into (persistent) colonial geographies of food and community in the NWT.
The Aurora borealis harmony as structural design in Eduard Tubin’s ‘Northern Lights’ Piano Sonata No. 2
Authors: Jurkowski Edward
Published: June 2013

The Estonian Eduard Tubin’s (1905-1982) second piano sonata, subtitled the “Northern Lights Sonata,” represents a significant turning point for the composer. Written between February and October in 1950, the sonata contains attributes that become hallmarks of Tubin’s mature style—namely, a highly concentrated compositional structure, an enriched, tonally ambiguous harmonic design, and the use of cyclically repeating theme groups. The subtitle of the composition comes from Tubin himself. Specifically, he noted that the work’s opening eight-note harmony represents the programmatic depiction of the whirling flashes from the northern lights he witnessed in Stockholm during 1949. In this article, I trace the various transformations of the Aurora borealis harmony in the second piano sonata and identify its role as a vital structural element of the composition. Following a descriptive assessment of the work’s three movements, I end by identifying some fascinating relationships between the piano sonata and other works by Tubin from this time period.
Les logiques du fonctionnement du discours esthétique chez les paysans du Salento. Une exégèse inachevée ?
Authors: Gervasi Flavia
Published: June 2013

Une fréquentation prolongée et intense entamée depuis 2008 avec un groupe restreint d’anciens chanteurs paysans du Salento, au sud de l’Italie, nous a persuadée qu’ils possèdent une esthétique de leur chant, bien que celle-ci ne soit jamais explicitée et que cette esthétique reflète un système de pensée en lien avec leur vie agricole. Nous sommes toutefois consciente du fait que dégager une conception, un système de pensée qui relève de l’esthétique, en absence d’un discours direct qui porte sur cette dimension et en absence de théorisation constitue une entreprise complexe. Notre étude se concentre alors sur l’observation et l’analyse d’attitudes linguistiques – tautologies, tentatives d’échapper aux questions du chercheur, etc. – qui, bien qu’apparemment lointaine d’un discours esthétique direct, cache un système de pensée relié à la dimension endogène du beau et du plaisant.
Portrait de la scolarisation des élèves québécois ayant le syndrome de Gilles de la Tourette
Authors: Leclerc Julie , Forget Jacques
Published: June 2013

L’étude présente les premières données concernant la scolarisation des élèves québécois ayant le SGT dans le contexte de la Politique de l’adaptation scolaire en lien avec la réforme de l’éducation. L’objectif est de présenter un portrait des manifestations comportementales, des troubles associés, de la classification en tant qu’élèves handicapés ou en difficulté d’adaptation ou d’apprentissage et des milieux éducatifs fréquentés par ces élèves. Un questionnaire d’enquête descriptive a été envoyé aux membres de l’Association québécoise du syndrome de la Tourette. Les résultats indiquent que 14 des 32 participants fréquentent des classes ordinaires. Le code de difficulté attribué pour les troubles relevant de la psychopathologie est néanmoins celui le plus souvent octroyé. La conclusion réfléchit aux interventions et au soutien apporté à ces élèves, en vue de leur réussite scolaire.
Navigating Between Rigour and Community-Based Research Partnerships: Building the Evaluation of the Uniting Our Nations Health Promotion Program for FNMI Youth
Authors: Crooks Claire V. , Snowshoe Angela , Chiodo Debbie , Brunette-Debassige Candace
Published: June 2013

Our team has worked closely with First Nations, Métis, and Inuit (FNMI) community partners and our local school board over the past 9 years to develop a range of strengths-based health promotion programs for FNMI youth. This article begins with a brief description of our school-based programming to provide context. Next, we identify challenges in conducting rigorous program evaluation and highlight the requirements of community-based research partnerships. Finally, we identify a number of factors that have helped us achieve a balance between the frameworks of rigour and community-based research partnerships. Throughout the paper we use examples from our projects to illustrate issues.
Understanding the Journey Through Homelessness: A Hermeneutic Study of Women Without Children
Authors: Osuji Joseph C. , Hirst Sandra P.
Published: June 2013

This study explored the meaning of the experience of homelessness and exiting homelessness among women without children. Convenience and snowball sampling techniques were used to recruit 12 women in an urban centre in Canada. Texts resulting from audiotaped interviews, participant observations, and reflective journal entries constituted data for analysis. Gadamerian hermeneutics informed the interpretive method used for analysis. The analysis yielded 5 subthemes that described the journey: (a) loss of self at home: the trigger; (b) non-feeling of “at-homeness”: dissociation; (c) disconnection and aloneness: homelessness; (d) simulating home: transitional shelter living; and (e) finding oneself: hopefulness. Findings suggest that exiting homelessness for women was a journey in search of hope, and reconnection with the self and others. This perspective suggests a new approach for policy and practice.
Les mauvais traitements psychologiques subis par les adolescents et adolescentes … des mots qui frappent!
Authors: Bêty Cynthia , Lavoie Francine , Nadeau Danielle
Published: June 2013

This qualitative study investigated perceptions of Psychological Maltreatment (PM) with 19 adolescent victims referred to a child welfare agency. The research objectives were: (a) to explore youths’ causal attributions of PM, their perceived control of the PM situation, and their perceptions of the abuser; and (b) to document whether these perceptions differ as a function of the nature of the relationship between the youth and his or her abuser. Thirty-six critical incidents were investigated through semi-structured interviews with 19 participants. Interview transcripts were subjected to content analysis. Results highlight the subjective suffering of PM victims in this population and the difference in perceptions of this kind of violence according to whether intrafamilial or extrafamilial PM is involved.
Interaction of Discharges in Heptane with Silicon Covered by a Carpet of Carbon Nanotubes
Authors: Hamdan Ahmad , Audinot Jean‐Nicolas , Migot‐Choux Sylvie , Noel Cédric , Kosior Francis , Henrion Gérard , Belmonte Thierry
Published: June 2013

Discharges in heptane in pin‐to‐plate configuration are produced between a platinum wire and a (100)‐oriented silicon wafer coated by a carbon nanotube (CNT) carpet. This carpet is used to simulate the behavior of a nanostructured surface in electro‐discharge machining (EDM) where small protrusions on the surface could play a similar role. CNTs behave like simple electrical conductors between the discharge and the silicon wafer. They act as if they would focus the current on smaller areas. The average diameter of impacts is about five times smaller if the silicon wafer is coated by a CNT carpet. The underlying silicon surface is heated by the plasma and melts, forming a central spot surrounded by a serrated trailing edge. The current density being about one order of magnitude larger when a CNT carpet is present, the induced magnetic field stirs the molten silicon, creating serrations all around the impact. Hot nanoparticles of carbon coming from the plasma fall and roll randomly on the silicon surface where they create wavy micro‐channels. Nanowires that are detached from the surface are covered by nanoparticles of platinum in the plasma and embedded within an amorphous carbon layer deposited on the nanotube. However, these effects can only be observed if the current density is high enough (>≈10 A µm−2 depending on the material) like in micro‐EDM but not in nano‐EDM.
A Bottom‐Up Approach to Build 3D Architectures from Nanosheets for Superior Lithium Storage
Authors: Gong Yongji , Yang Shubin , Zhan Liang , Ma Lulu , Vajtai Robert , Ajayan Pulickel M.
Published: June 2013

Two‐dimensional (2D) atomic layers such as graphene, and metal chalcogenides have recently attracted tremendous attention due to their unique properties and potential applications. Unfortunately, in most cases, the free‐standing nanosheets easily re‐stack due to their van der Waals forces, and lose the advantages of their separated atomic layer state. Here, a bottom‐up approach is developed to build three‐dimensional (3D) architectures by 2D nanosheets such as MoS2 and graphene oxide nanosheets as building blocks, the thin nature of which can be well retained. After simply chemical reduction, the resulting 3D MoS2‐graphene architectures possess high surface area, porous structure, thin walls and high electrical conductivity. Such unique features are favorable for the rapid diffusions of both lithium ions and electrons during lithium storage. As a consequence, MoS2‐graphene electrodes exhibit high reversible capacity of ≈1200 mAh g−1, with very good cycling performance. Moreover, such a simple and low‐cost assembly protocol can provide a new pathway for the large‐scale production of various functional 3D architectures for energy storage and conversions.
Site‐Specific Differentiation of Neural Stem Cell Regulated by Micropatterned Multicomponent Interfaces
Authors: Wang Ying , Xu Zhen , Kam Lance C. , Shi Peng
Published: June 2013

Stem cell microenvironments are enriched by signals from a variety of components, which cooperate spatially and temporally to regulate cellular function. In vitro recapitulating such complexity in a well‐controlled manner is elusive. Here, a platform for patterning multiple bio‐active proteins on a single substrate is developed and optimized, and is used it to study the cooperative involvement of cell–matrix interaction and cell–cell signaling in regulating neural stem cell (NSC) function. An affinity‐capturing‐based multi‐step microcontact printing is used to pattern, extracellular matrix proteins, and cell–cell signaling ligands, as intersecting lines on a nonadhesive background. Such design provides spatial segregation of signals from different extrinsic components, while allowing cell traffic between them during their proliferation and differentiation processes. Rat embryonic neural stem cells are cultured and characterized on the multicomponent substrates patterned with different combinations of fibronectin, N‐cadherin, and Jagged1 proteins and allow to proliferate and differentiate over long term. It is found that local presentation of Notch signaling ligand (Jagged1) or cell adhesion molecule (N‐cadherin) effectively modulate the balance between cell–cell and cell–matrix interaction, and significantly change the overall spatial remodeling of NSC differentiation. This platform provides an unambiguous approach to study the spatial and temporal cooperative involvement of different extrinsic components in regulating stem cell behavior. It is also readily expandable for inclusion of extra components and applicable to use with other types of cells, which provide a powerful tool for basic study of cell–material interaction or advanced tissue‐interface engineering.
Recent Advances in Applications and Performance of Inorganic Hollow Spheres in Devices
Authors: Chen Min , Ye Chenyu , Zhou Shuxue , Wu Limin
Published: June 2013

Inorganic hollow spheres have wide, important applications due to their unique structure, controllable morphology, and composition. Recent developments in the application and performance of inorganic hollow spheres in solar cells, UV photodectors, gas sensors, and supercapacitors are discussed. For each inorganic hollow sphere based device, a critical comment is given based on knowledge and related research experience. Some perspectives on the future research and development of these inorganic‐hollow‐sphere devices are given.
Enhanced cloud‐to‐ground lightning frequency in the vicinity of coal plants and highways in Northern Georgia, USA
Authors: Strikas Ona M. , Elsner James B.
Published: June 2013

Lightning amplification has been detected in areas with enhanced aerosol concentrations. Here the authors use cloud‐to‐ground (CG) lightning strike data across North Georgia to statistically model the lightning frequency as a function of distance from nearest coal plant and distance from nearest highway. Results show a threefold increase in lightning occurrence near coal plants and highways. Lightning enhancement near coal plants extends to distances exceeding 100 km; whereas, the lightning enhancement near highways is limited to a localized spike. The models explain not more than 11% of the spatial variability in flash frequency.
Stem Cells as a Good Tool to Investigate Dysregulated Biological Systems in Autism Spectrum Disorders
Authors: Griesi‐Oliveira Karina , Sunaga Daniele Yumi , Alvizi Lucas , Vadasz Estevão , Passos‐Bueno Maria Rita
Published: June 2013

Identification of the causes of autism spectrum disorders (ASDs) is hampered by their genetic heterogeneity; however, the different genetic alterations leading to ASD seem to be implicated in the disturbance of common molecular pathways or biological processes. In this scenario, the search for differentially expressed genes (DEGs) between ASD patients and controls is a good alternative to identify the molecular etiology of such disorders. Here, we employed genome‐wide expression analysis to compare the transcriptome of stem cells of human exfoliated deciduous teeth (SHEDs) of idiopathic autistic patients (n = 7) and control samples (n = 6). Nearly half of the 683 identified DEGs are expressed in the brain (P = 0.003), and a significant number of them are involved in mechanisms previously associated with ASD such as protein synthesis, cytoskeleton regulation, cellular adhesion and alternative splicing, which validate the use of SHEDs to disentangle the causes of autism. Autistic patients also presented overexpression of genes regulated by androgen receptor (AR), and AR itself, which in turn interacts with CHD8 (chromodomain helicase DNA binding protein 8), a gene recently shown to be associated with the cause of autism and found to be upregulated in some patients tested here. These data provide a rationale for the mechanisms through which CHD8 leads to these diseases. In summary, our results suggest that ASD share deregulated pathways and revealed that SHEDs represent an alternative cell source to be used in the understanding of the biological mechanisms involved in the etiology of ASD. Autism Res 2013, ●●: ●●–●●. © 2013 International Society for Autism Research, Wiley Periodicals, Inc.
Harvesting microalgae cultures with superabsorbent polymers: Desulfurization of Chlamydomonas reinhardtii for hydrogen production
Authors: Martín del Campo Julia S. , Patiño Rodrigo
Published: June 2013

It is presented in this work a new methodology to harvest fresh water microalgae cultures by extracting the culture medium with superabsorbent polymers (SAPs). The microalgae Chlamydomonas reinhardtii were grown in the Sueoka culture medium, harvested with polyacrylic SAPs and re‐suspended in the culture medium tris‐acetate‐potassium without sulfur (TAP‐S) to generate hydrogen (H2) under anoxic conditions. The H2 production as an alternative fuel is relevant since this gas has high‐energy recovery without involving carbon. Before microalgae harvesting, a number of range diameters (1–7 mm) for SAPs spherical particles were tested, and the initial rate (V0) and the maximal capacity (Qmax) were determined for the Sueoka medium absorption. The SAP particles with the diameter range 2.0–2.5 mm performed the best and these were employed for the rest of the experiments. The Sueoka medium has a high salt content and the effect of the ionic strength was also studied for different medium concentrations (0–400%). The SAPs were reused in consecutive absorption/desorption cycles, maintaining their absorption capacity. Although the Sueoka medium reduces the SAPs absorption capacity to 40% compared with deionized water, the use of SAPs was very significant for the desulfurization process of C. reihardtii. The presence of C. reinhardtii at different concentrations does not affect the absorption capacity of the Sueoka culture medium by the SAPs. In order to reduce the time of the process, an increase of the SAPs concentration was tested, being 20 g of SAP per liter of medium, a condition to harvest the microalgae culture in 4 h. There were no evident cell ruptures during the harvesting process and the cells remained alive. Finally, the harvested biomass was re‐suspended in TAP‐S medium and kept under anaerobic conditions and illumination to produce H2 that was monitored by a PEM fuel cell. The use of SAPs for microalgae harvesting is a feasible non‐invasive procedure to obtain high concentrations of functional biomass at low cost; it offers an attractive alternative due to its versatility and simplicity. Biotechnol. Bioeng. 2013;110: 3227–3234. © 2013 Wiley Periodicals, Inc.
Steady‐State Plasma Concentration of Donepezil Enantiomers and Its Stereoselective Metabolism and Transport In Vitro
Authors: Lili Wan , Cheng Guo , Zhiyong Zhou , Qi Yu , Yan Li , Dan Li , Xueli Zheng , Yuan Zhong
Published: June 2013

The aim of the present study was to elucidate the differences in the plasma concentration of two enantiomers of donepezil in Chinese patients with Alzheimer's disease (AD) and investigate in vitro stereoselective metabolism and transport. Donepezil enantiomers were separated and determined by LC‐MS/MS using D5‐donepezil as an internal standard on a Sepax Chiralomix SB‐5 column. In vitro stereoselective metabolism and transport of donepezil were investigated in human liver microsomes and MDCKII‐MDR1 cell monolayer. Pre‐dose (Css‐min) plasma concentrations were determined in 52 patients. The mean plasma level of (R)‐donepezil was 14.94 ng/ml and that of (S)‐donepezil was 23.37 ng/ml. One patient's plasma concentration of (R)‐donepezil was higher than (S)‐donepezil and the ratio is 1.51. The mean plasma levels of (S)‐donepezil were found to be higher than those of (R)‐donepezil in 51 patients and the ratio of plasma (R)‐ to (S)‐donepezil varies from 0.34 to 0.85. In the in vitro microsomal system, (R)‐donepezil degraded faster than (S)‐donepezil. Vmax of (R)‐donepezil was significantly higher than (S)‐donepezil. The P‐gp inhibition experiment shown that the Papp of the two enantiomers was higher than 200 and the efflux ratios were 1.11 and 0.99. The results of the P‐gp inhibition identification experiment showed IC50 values of 35.5 and 20.4 μM, respectively, for the two enantiomers. The results indicate that donepezil exhibits stereoselective hepatic metabolism that may explain the differences in the steady‐state plasma concentrations observed. Neither (R)‐ nor (S)‐donepezil was a P‐gp substance and the two enantiomers are highly permeable through the blood–brain barrier. Chirality 25:498–505, 2013. © 2013 Wiley Periodicals, Inc.
(S)‐(−)‐(2‐MeBu)N(Pr)2MeI Salt as Template in the Enantioselective Synthesis of the Enantiopure Two‐dimensional (S)‐(−)‐(2‐MeBu)N(Pr)2Me[ΛMnΔCr(C2O4)3] Ferromagnet
Authors: Gruselle Michel , Li Yanling , Ovanesyan Nikolay , Makhaev Viktor , Shilov Gennadi , Mushenok Fedor , Train Cyrille , Aldoshin Serguey
Published: June 2013

We describe herein the synthesis of (rac)‐ or enantiopure (S)‐(−)‐(2‐MeBu)N(Pr)2MeI ammonium salts. These racemic and enantiopure ammonium salts were used as cationic templates to obtain new two‐dimensional (2D) ferromagnets [(rac)‐(2‐MeBu)N(Pr)2Me][MnCr(C2O4)3] and [(S)‐(−)‐(2‐MeBu)N(Pr)2Me][ΔMnΛ nCr(C2O4)3]. The absolute configuration of the hexacoordinated Cr(III) metallic ion in the enantiopure 2D network was determined by a circular dichroism measurement. The structure of [(2‐MeBu)N(Pr)2Me][MnCr(C2O4)3], established by single crystal X‐ray diffraction, belongs to the chiral P63 space group. According to direct current (dc) magnetic measurements, these compounds are ferrromagnets with a temperature Tc = 6°K. Chirality 25:444–448, 2013. © 2013 Wiley Periodicals, Inc.
Organization of protein complexes and a mechanism for grana formation in photosynthetic membranes as revealed by cryo‐electron microscopy
Authors: Ford R. C. , Holzenburg A.
Published: June 2013

Plant and algal chloroplasts and their ultrastructure were one of the first specimens to be studied by microscopy, and their granular nature was first described by Van Leeuwenhoek in 1676. Here we have used cryo‐electron tomography and three‐dimensional reconstruction to resolve chloroplast ultrastructure at a level where individual protein complexes can be observed. The data reveal features of the ultrastructure which are consistent with a simple hypothesis for the generation of the characteristic stacked grana described by Leeuwenhoek. We find that stacked regions can be formed by invaginations of the ‘sac‐like’ structure of the membrane. Two, or more, invaginations associate together to give stacks of membranes within the sac. In the tomograms, both the stacked and unstacked regions of the membrane display lateral heterogeneity in terms of the particles embedded in them. Unstacked regions display microdomains that are densely packed with CF1‐CF0 proton ATPases that predominantly occupy parts where the disk‐shaped sacs curve at the periphery. Stacked regions display membranes packed with photosystem II complexes.
Overcoming Bottlenecks of Enzymatic Biofuel Cell Cathodes: Crude Fungal Culture Supernatant Can Help to Extend Lifetime and Reduce Cost
Authors: Sané Sabine , Jolivalt Claude , Mittler Gerhard , Nielsen Peter J. , Rubenwolf Stefanie , Zengerle Roland , Kerzenmacher Sven
Published: June 2013

Enzymatic biofuel cells (BFCs) show great potential for the direct conversion of biochemically stored energy from renewable biomass resources into electricity. However, enzyme purification is time‐consuming and expensive. Furthermore, the long‐term use of enzymatic BFCs is hindered by enzyme degradation, which limits their lifetime to only a few weeks. We show, for the first time, that crude culture supernatant from enzyme‐secreting microorganisms (Trametes versicolor) can be used without further treatment to supply the enzyme laccase to the cathode of a mediatorless BFC. Polarization curves show that there is no significant difference in the cathode performance when using crude supernatant that contains laccase compared to purified laccase in culture medium or buffer solution. Furthermore, we demonstrate that the oxygen reduction activity of this enzymatic cathode can be sustained over a period of at least 120 days by periodic resupply of crude culture supernatant. This is more than five times longer than control cathodes without the resupply of culture supernatant. During the operation period of 120 days, no progressive loss of potential is observed, which suggests that significantly longer lifetimes than shown in this work may be possible. Our results demonstrate the possibility to establish simple, cost efficient, and mediatorless enzymatic BFC cathodes that do not require expensive enzyme purification procedures. Furthermore, they show the feasibility of an enzymatic BFC with an extended lifetime, in which self‐replicating microorganisms provide the electrode with catalytically active enzymes in a continuous or periodic manner.
Candida rugosa lipase‐catalyzed synthesis of sucrose‐6‐acetate in a 2‐butanol/buffer two‐phase system
Authors: Zhong Xiang , Qian Junqing , Liu Min , Ma Lingzhi
Published: June 2013

Sucrose‐6‐acetate, a short‐chain monoester, is an important intermediate for the preparation of sucralose. Regioselective transformations of mono‐ and oligosaccharides by enzymes have been performed in organic solvents. The present study was carried out with Candida rugosa lipase to synthesize sucrose‐6‐acetate by transesterification of sucrose and vinyl acetate in a two‐phase system consisting of a buffer solution and an organic solvent. The screening results revealed that 2‐butanol/Tris‐HCl was the optimal two‐phase system for biocatalysis, and other factors influencing the synthesis of sucrose‐6‐acetate were also studied. Three major factors (temperature, initial buffer pH, and molar ratio of substrates) were identified through Plackett–Burman design, and the response surface methodology was employed to optimize the reaction process. Under optimal conditions, the yield of sucrose‐6‐acetate reached up to 57.42%. The aqueous two‐phase system was successfully applied to the synthesis of sucrose‐6‐acetate with high yield, low toxicity, good resolution, low cost, and simple scale‐up.
Thiobencarb Herbicide Reduces Growth, Photosynthetic Activity, and Amount of Rieske Iron‐Sulfur Protein in the Diatom Thalassiosira pseudonana
Authors: Shimasaki Yohei , Tsuyama Michito , Tasmin Rumana , Qiu Xuchun , Shimizu Motoyuki , Sato Yusuke , Yamasaki Yasuhiro , Kato‐Unoki Yoko , Nukata Atsushi , Nakashima Takashi , Ichinose Hirofumi , Wariishi Hiroyuki , Honjo Tsuneo , Oshima Yuji
Published: June 2013

We investigated the effects of the herbicide thiobencarb on the growth, photosynthetic activity, and expression profile of photosynthesis‐related proteins in the marine diatom Thalassiosira pseudonana. Growth rate was suppressed by 50% at a thiobencarb concentration of 1.26 mg/L. Growth and photosystem II activity (Fv/Fm ratio) were drastically decreased at 5 mg/L, at which the expression levels of 13 proteins increased significantly and those of 11 proteins decreased significantly. Among these proteins, the level of the Rieske iron‐sulfur protein was decreased to less than half of the control level. This protein is an essential component of the cytochrome b6f complex in the photosynthetic electron transport chain. Although the mechanism by which thiobencarb decreased the Rieske iron‐sulfur protein level is not clear, these results suggest that growth was inhibited by interruption of the photosynthetic electron transport chain by thiobencarb. © 2013 Wiley Periodicals, Inc. J BiochemMol Toxicol 27:437‐444, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/jbt.21505
Comparative analysis of the performance of commonly available density functionals in the determination of geometrical parameters for copper complexes
Authors: Sousa Sérgio F. , Pinto Gaspar R. P. , Ribeiro António J. M. , Coimbra João T. S. , Fernandes Pedro A. , Ramos Maria João
Published: June 2013

In this study, a set of 50 transition‐metal complexes of Cu(I) and Cu(II), were used in the evaluation of 18 density functionals in geometry determination. In addition, 14 different basis sets were considered, including four commonly used Pople's all‐electron basis sets; four basis sets including popular types of effective‐core potentials: Los Alamos, Steven‐Basch‐Krauss, and Stuttgart‐Dresden; and six triple‐ζ basis sets. The results illustrate the performance of different methodological alternatives for the treatment of geometrical properties in relevant copper complexes, pointing out Double‐Hybrid (DH) and Long‐range Correction (LC) Generalized Gradient Approximation (GGA) methods as better descriptors of the geometry of the evaluated systems. These however, are associated with a computational cost several times higher than some of the other methods employed, such as the M06 functional, which has also demonstrated a comparable performance. Regarding the basis sets, 6–31+G(d) and 6–31+G(d,p) were the best performing approaches. In addition, the results show that the use of effective‐core potentials has a limited impact, in terms of the accuracy in the determination of metal‐ligand bond‐lengths and angles in our dataset of copper complexes. Hence, these could become a good alternative for the geometrical description of these systems, particularly CEP‐121G and SDD basis sets, if one is considering larger copper complexes where the computational cost could be an issue. © 2013 Wiley Periodicals, Inc.