bluuebunny/crossref_metadata_2025 huggingface dataset:
Gender Terminology and Indexing Systems: The Case of Woman's Body, Image and Visualization
Authors: López-Huertas María J. , Ramírez Isabel de Torres
Published: January 2008

Representation and organization of knowledge in interdisciplinary/transdisciplinary domains have attracted little attention among specialists in Information Science. The lack of attention has affected the management of this kind of information in a negative way because models used for handling interdisciplinary information are based on or inspired by disciplinarity, causing problems in information retrieval. This study is part of broader research aiming to analyze an interdisciplinary domain, in this case Gender Studies, in order to identify its terminological behaviour and its conceptual dynamics for information retrieval. On the basis of a selected lexicon of 333 terms taken from a total of 5,200 terms coming from different sources, this study aims to bring to light the model followed in the representation of concepts related to the health, image and body of women, and their visualization in texts specialized in gender and in information retrieval systems, particularly in Gender thesauri. Secondary objectives are to determine if these sources suffer from gender bias and other types of prejudices of social constructions, here in regards to the body and the health of women, and to identify the research interest that these topics awaken, as reflected in the selected collection of specialized documents. To this end, a quantitative analysis of the selected terminology was done, comparing the results obtained with the selected lexicon from the indexing systems with the lexicon obtained from the primary sources, to detect coinciding terms and possible differences between the two, and so to appraise the documental warrant of the systems. Finally, the terms were grouped into categories in order to reveal the most relevant aspects for representation in the overall context of women's health, the female body and the image of women.
Digitising the Hand-Written Bible: The Codex Sinaiticus, its History and Modern Presentation
Authors: Henschke Ekkehard
Published: January 2008

The German theologian Konstantin von Tischendorf discovered the oldest manuscript of the Bible in the middle of the 19th century. Thereafter its parts were dispersed and stored in famous libraries in London, Leipzig and St. Petersburg, and in St. Catherine's Monastery near Mount Sinai, its original home. An international consortium of libraries has been formed to preserve and research all the parts of this manuscript and then to unite them in digital form. This will result in a virtual Codex Sinaiticus on the Internet, though there will also be a printed version. Standards for preservation, transcription and digitisation have been established with the help of European and U.S. experts. This joint venture, supported by a number of research councils and foundations, began in 2006 and will be completed by 2010.
Surfacing Filipino School Children's Images of Librarians through Doodling
Authors: Guzman Allan De , Custodio Sheena Mai B. , Garcia Melissa Angela P.
Published: January 2008

This qualitative study describes how Filipino grade school pupils in a private, sectarian school in Manila, Philippines identify their views and images of the librarian. Two hundred fifty-eight (258) pupils were asked to fill out a robotfoto box for illustration and to fill in a diagram. As a result of the data gathered and analyzed, two (2) faces of the librarian came into view, based on the children's doodling, the desirable and the undesirable librarian. On the one hand, the desirable librarian represents the enticing, enduring and engaging type. On the other hand, disappointing, depressing and depriving types characterize the librarian who is undesirable. The doodlings indicate that being desirable attracts library clients to visit the library and develops interest in using the library facilities more often. The undesirable qualities make students hesitate in entering the library. This study shows the need for librarians to be concerned with improving their images to develop desired qualities for the benefit of their student clientele.
Was messen Temperatursensoren in einer Biomasse-Feuerung wirklich? (What is Really Measured by Temperature Sensors in a Biomass Furnace?)
Authors: Bauer Robert , Gölles Markus , Brunner Thomas , Dourdoumas Nicolaos , Obernberger Ingwald
Published: January 2008

In Biomasse-Feuerungsanlagen wird eine Vielzahl von Temperatursensoren eingesetzt. Einerseits müssen diese Sensoren gegenüber Verschmutzung, mechanischen Beanspruchungen und großen Temperatursprüngen unempfindlich sein; andererseits sollen sie möglichst kostengünstig sein. Dadurch werden bewusst Kompromisse hinsichtlich einer schnellen und genauen Messung eingegangen. In diesem Beitrag werden einfache mathematische Modelle vorgestellt, die den Zusammenhang zwischen Prozessgrößen und den gemessenen Temperaturen beschreiben. Man kann sie zur Abschätzung der tatsächlichen Temperaturen und für modellbasierte Regelungsstrategien einsetzen.
Alterations of Sertoli cell activity in the long-term testicular germ cell death process induced by fetal androgen disruption
Authors: Benbrahim-Tallaa Lamia , Siddeek Bénazir , Bozec Aline , Tronchon Virginie , Florin Anne , Friry Claire , Tabone Eric , Mauduit Claire , Benahmed Mohamed
Published: January 2008

Fetal androgen disruption, induced by the administration of anti-androgen flutamide (0.4, 2, and 10 mg/kg day) causes a long-term apoptosis in testicular germ cells in adult male rat offspring. One of the questions raised by this observation is the role of the Sertoli cells in the adult germ cell apoptotic process. It is shown here that Sertoli cells originating from 15-day-old rats treated in utero with the anti-androgen (10 mg/kg d) did no longer protect adult germ cells against apoptosis. Indeed, untreated spermatocytes or spermatids exhibited increased (P<0.0001) active caspase-3 levels when co-cultured with Sertoli cells isolated from rat testes exposed in utero to the anti-androgen. This alteration of Sertoli cell functions was not due to modifications in the androgen signal in the adult (90-day-old) animals, since plasma testosterone and estradiol, androgen receptor expression, and androgen-targeted cell number (e.g., Sertoli cells in the seminiferous tubules) were not affected by the fetal androgen disruption. In contrast, this inability of Sertoli cells to protect germ cells against apoptosis could be accounted for by the potential failure of Sertoli cell functions. Indeed, adult testes exposed in utero to anti-androgens displayed decreased levels of several genes mainly expressed in adult Sertoli cells (anti-Mullerian hormone receptor type II (AMHR2), Cox-1, cyclin D2, cathepsin L, and GSTα). In conclusion, fetal androgen disruption may induce alterations of Sertoli cell activity probably related to Sertoli cell maturation, which potentially leads to increased adult germ cell apoptosis.
High glucose enhances lipopolysaccharide-stimulated CD14 expression in U937 mononuclear cells by increasing nuclear factor κB and AP-1 activities
Authors: Nareika Alena , Im Yeong-Bin , Game Bryan A , Slate Elizabeth H , Sanders John J , London Steven D , Lopes-Virella Maria F , Huang Yan
Published: January 2008

We have demonstrated recently that high glucose augments lipopolysaccharide (LPS)-stimulated matrix metalloproteinase (MMP) and cytokine expression by U937 mononuclear cells and human monocyte-derived macrophages. Since CD14 is a receptor for LPS, one potential underlying mechanism is that high glucose enhances CD14 expression. In the present study, we determined the effect of high glucose on CD14 expression by U937 mononuclear cells. After being chronically exposed to normal or high glucose for 2 weeks or longer, cells were treated with LPS for 24 h. Real-time PCR showed that although high glucose by itself did not increase CD14 expression significantly, it augmented LPS-stimulated CD14 expression by 15-fold. Immunoassay showed a marked enhancement of both membrane-associated and soluble CD14 protein levels by high glucose. Further investigations using transcription factor activity assays and gel shift assays revealed that high glucose augmented LPS-stimulated CD14 expression by enhancing transcription factor nuclear factor κB (NFκB) and activator protein-1 (AP-1) activities. Finally, studies using anti-CD14 neutralizing antibody showed that CD14 expression is essential for the enhancement of LPS-stimulated MMP-1 expression by high glucose. Taken together, this study has demonstrated a robust augmentation by high glucose of LPS-stimulated CD14 expression through AP-1 and NFκB transcriptional activity enhancement, elucidating a new mechanism by which hyperglycemia boosts LPS-elicited gene expression involved in inflammation and tissue destruction.
Cooperative regulation of endogenous cAMP-response element binding protein and CCAAT/enhancer-binding protein β in GH-stimulated c-fos expression
Authors: Cui Tracy Xiao , Kwok Roland , Schwartz Jessica
Published: January 2008

GH activates the c-fos promoter by regulating multiple transcription factors. This study adds to our understanding of GH-regulated transcription by demonstrating that GH regulates the c-fos cAMP-response element (CRE) and its binding protein, CREB. Activation of the c-fos promoter by GH is impaired by expression of dominant-negative A-CREB. GH stimulates rapid and transient phosphorylation of CREB at Ser 133 (P-CREB), a critical site for transactivation by CREB, in 3T3-F442A preadipocytes. Mutation of this residue impairs GH-induced c-fos expression, suggesting that phosphorylation of CREB at Ser 133 contributes to GH-induced c-fos activation. The MEK inhibitor UO126 impaired the phosphorylation of CREB and that of C/EBPβ, suggesting that ERKs mediate the phosphorylation of both proteins. UO126, but not the protein kinase A inhibitor H89, blocked GH-induced c-fos mRNA expression. A combination of CREB and C/EBPβ enhanced c-fos promoter activation, and mutation of the CRE impaired the enhancement, as well as GH-stimulated c-fos activation. GH treatment increased the occupancy of both endogenous phospho-CREB and phospho-C/EBPβ on the c-fos promoter. The increases were impaired by UO126. The active P-CREB and P-C/EBPβ are induced by GH to occupy the same c-fos promoter DNA, suggesting that they may participate in a GH-regulated complex on c-fos. These findings suggest that coordinated phosphorylation of CREB and C/EBPβ in response to GH is mediated by ERK1/2, and that the phosphorylated proteins are part of a regulatory complex that occupies c-fos in vivo to regulate c-fos transcription cooperatively in response to GH.
The transcription of steroidogenic genes in the human cerebellum and hippocampus: a comparative survey of normal and Alzheimer's tissue
Authors: MacKenzie Scott M , Dewar Deborah , Stewart William , Fraser Robert , Connell John M C , Davies Eleanor
Published: January 2008

Steroid actions on brain tissue have been implicated in processes such as blood pressure regulation and neurodegeneration, including the progression of Alzheimer's disease (AD). mRNAs from all of the genes required for de novo synthesis from cholesterol of aldosterone and corticosterone (equivalent to cortisol in humans) have been identified in rat brain, together with abundant steroid hormone receptors, but the situation in human brain requires clarification. We used real-time RT-PCR to assess whether transcription of 13 steroid-associated genes occurs in human hippocampus and cerebellum, and to identify whether transcription of these genes is significantly altered in cases of AD. Frozen post-mortem samples of hippocampus and cerebellum from patients with AD (n=7) and age-matched controls free from neurological disease at the time of death (n=9) were used. We found all of the genes under investigation to be transcribed within normal and AD hippocampus and cerebellum except for CYP11B1 (11β-hydroxylase), CYP11B2 (aldosterone synthase) and CYP17 (17α-hydroxylase). No significant differences in mRNA levels were observed between the AD tissue and the equivalent control tissue, although significant regional differences in gene transcription were observed between hippocampus and cerebellum in AD and control samples. The absence of key mRNAs from human hippocampus and cerebellum rules out the de novo generation of aldosterone, cortisol or the sex steroids within these regions. However, the pattern of gene expression does suggest that the mineralocorticoid 11-deoxycorticosterone can be generated de novo. There is no evidence of a link between AD and altered steroid biosynthesis within human hippocampus and cerebellum.
Ontogenetic and tissue-specific expression of preproghrelin in the Atlantic halibut, Hippoglossus hippoglossus L.
Authors: Manning Anthony J , Murray Harry M , Gallant Jeffrey W , Matsuoka Makoto P , Radford Emily , Douglas Susan E
Published: January 2008

Ghrelin is a conserved vertebrate hormone that affects both GH release and appetite. We have cloned and characterized Atlantic halibut preproghrelin cDNA and examined for the first time preproghrelin expression during fish larval development using quantitative real-time PCR. In addition, cellular sites of expression in larvae and tissue-specific expression in 3-year-old halibut were studied. A full-length cDNA for preproghrelin was isolated from halibut stomach tissue. The 899 bp cDNA encodes an open reading frame of 105 amino acids that is comprised of a signal peptide and two peptides with high similarity to ghrelin and obestatin. The deduced amino acid sequence of halibut ghrelin peptide (GSSFLSPSHKPPKGKPPRA) shows significant conservation relative to other teleostean sequences and is identical to human ghrelin for the first seven amino acids of the sequence. The putative obestatin peptide is well-conserved among fishes but shares limited similarity with its human counterpart. Expression of ghrelin was localized to two different cell types in the stomach of larval halibut by in situ hybridization. However, sensitive PCR assays on tissues collected from 3-year-old fish additionally identified ghrelin transcripts in pyloric caecae, intestine, and in immature ovary and testis. Ontogenetic studies detected ghrelin expression prior to exogenous feeding during larval development (hatching and mouth-opening stages) with increased expression occurring through metamorphosis. This increase was pronounced during climax metamorphosis and coincided with stomach differentiation. Patterns of preproghrelin expression suggest that ghrelin has important roles during and after larval development in halibut, and that ghrelin is associated with digestive and gonadal tissues in this teleost.
Effects of packing density, excess water and solid surface area on flowability of cement paste
Authors: Kwan A. K. H. , Wong H. H. C.
Published: January 2008

Although it has been postulated for many years that it is excess water rather than whole water that lubricates the cementitious materials and governs flowability of paste (excess water is water in excess of that needed to fill up voids), there has been no detailed investigations to study the actual effects of excess water. This was due to the lack of a suitable method for measuring the packing density and voids content of cementitious materials. To resolve the problem, the authors have recently developed a new wet packing method that was applied herein to measure the packing densities and voids contents of cementitious materials containing different amounts of cement, pulverised fuel ash and condensed silica fume. The flowability properties of the paste formed of the cementitious materials with different water contents were also measured and correlated to the excess water contents, each determined as water content minus voids content. The results revealed that whereas an improvement in packing density would increase excess water content, flowability is governed mainly by excess water to solid volume and excess water to solid surface area ratios.
Characterisation of calcined paper sludge as an environmentally friendly source of metakaolin for manufacture of cementitious materials
Authors: Frías M. , Sánchez de Rojas M. I. , Rodríguez O. , Jiménez R. García , de la Villa R. Vigil
Published: January 2008

The correct assessment of industrial by-products and waste materials requires an in-depth knowledge of their characteristics. In thermally activated products, the calcining conditions have an important influence on the properties and later behaviour of cementitious matrices. The present study was carried out to determine the effect of calcining conditions (2–5 h at 700–800°C) on the properties of treated paper sludge. Various chemical, physical, morphological, mineralogical and pozzolanic characteristics were evaluated in order to provide a complete understanding of the properties of the calcined sludge and the possibility of using them in the manufacture of blended cements. The results showed that the thermal conditions have a major influence on the properties of the calcined sludge, primarily the mineralogical and morphological properties, as well as the pozzolanic behaviour.
CCT diagrams of tricalcium silicate decomposition
Authors: Tenório J. A. S. , Pereira S. S. R. , Ferreira A. V. , Espinosa D. C. R. , Barros A. M. , Araújo F. G. da S.
Published: January 2008

The mechanical properties of Portland cement are closely related to the chemical composition of the clinker, and particularly to the concentration of tricalcium silicate, C3S. In the industrial production process, the clinker must be rapidly quenched, to avoid its decomposition into dicalcium silicate and lime and also to avoid the transformation from higher temperature phases to lower temperature phases. This study investigated the kinetics of thermal decomposition of the C3S. Samples of laboratory-made C3S were thermally treated under specific conditions to determine the continuous cooling transformation (CCT) diagram of the material. The CCT diagram of the C3S showed decomposition rates with values that were much higher than the values traditionally accepted in the literature.
Pozzolanic reactivity of nanoscale pyrogene oxides and their strength contribution in cement-based systems
Authors: Korpa A. , Trettin R. , Böger K. G. , Thieme J. , Schmidt C.
Published: January 2008

This paper deals with the pozzolanic reactivity of pyrogene oxides (represented by Aerosil) that belong to the colloidal silicas. Pyrogene oxides are highly reactive pozzolanic nanoscale additives. They react much faster pozzolanically than other commonly used pozzolans and in this way they consume the available calcium hydroxide in a much shorter time. It is shown by using in situ X-ray transmission microscopy, pH-change measurements and the strength property results that Aerosil begins to react as early as the first hour of contact with both the added calcium hydroxide in solution and with the products of the tricalcium silicate (C3S) hydration reaction. In comparison with the other commonly used pozzolans, that is, silica fume, pyrogene oxides contribute by developing a better early and final strength. The concrete specimens that were cast by combining silica fume with small quantities of Aerosil were considered to belong to the ultra high performance class and were additionally characterised by finer pores and reduced total porosity.
Synthesis and biological evaluation of thieno[2,3-d]pyrimidine derivatives for anti-inflammatory, analgesic and ulcerogenic activity
Authors: El-Gazzar Abdel-Rahman , Hussein Hoda , Hafez Hend
Published: January 2008

Synthesis and biological evaluation of thieno[2,3-d]pyrimidine derivatives for anti-inflammatory, analgesic and ulcerogenic activity

5-Methyl-6-phenyl-2-thioxothieno[2,3-d]pyrimidone derivative (2) reacted with hydrazonoyl chloride derivatives to afford triazolothienopyrimidones4a-f.Also, acetone-1-(2-amino-5-isopropyl-thiophene-3-carbonitrile) (3) reacted with functional and bifunctional groups to yield the corresponding compounds5-11. The new products showed anti-inflammatory, analgesic, and ulcerogenic activities comparable to that of indomethacin and acetylsalicylic acid, respectively.
Caring for men in contemporary Russia
Authors: Kay Rebecca
Published: January 2008

This article explores gendered constructions of care and need and the ways in which these affect men's social security in contemporary Russia. It is suggested that gendered caring practices, besides overburdening women and devaluing their labor, also contribute to a trivialization of men's needs and their marginalization in, and/or exclusion from, complex forms of social security. Social security is understood to encompass both material and emotional support structures and networks, involving both state and nonstate actors. It is argued that hybrid forms of provision are emerging, with new actors challenging and blurring strict categorizations of state/nonstate, formal/informal, and material/ emotional in their contribution to social security. The article draws on a study of the Altai Regional Crisis Center for Men and its attempts to identify men's needs for social support, to provide appropriate forms of care, and to enhance the social security of men in the Altai Region of Western Siberia.
Functional evidence for presence of lipid rafts in erythrocyte membranes: Gsα in rafts is essential for signal transduction
Authors: Kamata Kotoe , Manno Sumie , Ozaki Makoto , Takakuwa Yuichi
Published: January 2008

Membrane microdomains enriched in cholesterol and sphingolipids and containing specific membrane proteins are designated as lipid rafts. Lipid rafts have been implicated in cell signaling pathways in various cell types. Heterotrimeric guanine nucleotide‐binding protein (Gsα) has been shown to be a raft component of erythrocytes and has been implicated in cell signaling. Rafts are isolated as detergent‐resistant microdomains (DRMs) for biochemical analysis. Cholesterol depletion is widely used to disrupt raft structures to study their function in biological membranes. In the present study, we developed an alternate strategy for disrupting raft structures without altering membrane cholesterol content. Lidocaine hydrochloride, an amphipathic local anesthetic, is shown to reversibly disrupt rafts in erythrocyte membranes and alter the Gsα dependent signal transduction pathway. These findings provide evidence for the presence of rafts while maintaining normal cholesterol content in erythrocyte membranes and confirm a role for raft‐associated Gsα in signal transduction in erythrocytes. Am. J. Hematol., 2008. © 2008 Wiley‐Liss, Inc.
Prevalence of polycythemia vera and essential thrombocythemia
Authors: Ma Xiaomei , Vanasse Gary , Cartmel Brenda , Wang Yun , Selinger H. Andrew
Published: January 2008

Polycythemia vera (PV) and essential thrombocythemia (ET) are common types of myeloproliferative disorders (MPD), the prevalence of which has not been well documented in the United States. Recent breakthroughs in the molecular etiology of these disorders and the accelerated development of targeted pharmacotherapeutics to treat them underscore the need to define the affected population. In this study, we obtained health claims data from major commercial insurance payers in Connecticut and the Center for Medicare and Medicaid Services to estimate the prevalence of PV and ET. Specifically, logistic regression was utilized to develop algorithms to predict the probability that an individual with claims suggestive of MPD truly has PV or ET, and the algorithms were then applied to health claims to estimate the number of PV and ET patients in Connecticut. As of 2003, the age‐standardized prevalence was 22 per 100,000 and 24 per 100,000 for PV and ET, respectively, in Connecticut. Applying the age‐specific prevalence of PV and ET to the entire US population resulted in an estimated total of 65,243 patients with PV and 71,078 patients with ET in the United States in 2003. This study is the first to assess the prevalence of PV and ET in a large US population. Given the large number of individuals afflicted with these diseases and the fact that demographic changes alone will further increase the burden of these diseases in the foreseeable future, it is imperative to conduct more systematic research into the etiology and treatment of PV and ET. Am. J. Hematol., 2008. © 2008 Wiley‐Liss, Inc.
Green tobacco sickness and skin integrity among migrant latino farmworkers
Authors: Arcury Thomas A. , Vallejos Quirina M. , Schulz Mark R. , Feldman Steven R. , Fleischer Alan B. , Verma Amit , Quandt Sara A.
Published: January 2008

Background

Green tobacco sickness (GTS) affects approximately one‐quarter of tobacco workers. The primary aim of this analysis is to expand existing knowledge of GTS risk factors by delineating the association of measures of skin integrity with the prevalence of GTS among Latino farmworkers.

Methods

Data are from a longitudinal study of skin disease among 304 North Carolina Latino farmworkers conducted in 2005.

Results

18.4% of the farmworkers met the GTS case definition. Self‐reported rash increased the odds of having GTS in the bivariate (OR 2.29, 95% CI 1.21, 4.35), and multivariate analyses (OR 3.30, CI 2.17, 5.02). Self‐reported itch (OR 3.54, CI 2.38, 5.24) and superficial wounds (OR 2.49, CI 1.15, 5.39) had a significant relationship to GTS in the bivariate analysis.

Conclusions

These analyses extend current knowledge of GTS risk factors to include skin integrity. Farmworkers with rash and other skin conditions can protect these affected skin areas from exposure to the tobacco plant to reduce their risk of GTS. Am. J. Ind. Med. 51:195–203, 2008. © 2008 Wiley‐Liss, Inc.
Synthesis and aging properties of reactive antioxidant NAPM in natural rubber vulcanizates
Authors: Lu Yunling , Yang Jianhua , Yin Dehong , Tan Ming , Wang Jinqu
Published: January 2008

The rubber antioxidant N‐(4‐anilinophenyl) methacrylamide (NAPM) was synthesized by a two‐step reaction using thionyl chloride (SOCl2) with methacrylic acid (MAA) and consequently 4‐aminodiphenylamine (ADPA) as precursors. NAPM was characterized by IR, 1H NMR and elemental analysis. Thermal stability, aging property of NAPM and mechanical properties of natural rubber (NR) vulcanizates containing NAPM were investigated and compared with two other commercial antioxidants N‐isopropyl‐N′‐phenyl‐p‐phenylene diamide (4010NA) and N‐(1, 3‐dimethyl butyl)—N′‐phenyl‐p‐phenylene diamide (4020). It was found that NAPM was an effective antioxidant with a better thermal stability and higher antiaging resistance than unreactive antioxidants 4010NA and 4020. And unsaturation level of NR vulcanizates containing NAPM was lower than that of 4010NA and 4020. Moreover, an antiaging resistant mechanism of a surface reaction between NAPM and cis‐1, 4‐polyisoprene in NR was proposed to explain the better properties of NAPM based on the IR and SEM analyses. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Preparation and application of silver nanoparticles on silk for imparting antimicrobial properties
Authors: Gulrajani M. L. , Gupta Deepti , Periyasamy S. , Muthu S. G.
Published: January 2008

Silver nanoparticles were produced by a chemical reduction method that reduced silver nitrate with reducing agents such as hydrazine and glucose. The silver nanoparticles were characterized with transmission electron microscope, scanning electron microscope, and optical microscope. The effects of process parameters such as the stirring speed, temperature, type of reducing agent, and dispersing agent on the particle size were studied. The particle size decreased with an increase in the stirring speed and a decrease in the process temperature. Smaller particles were formed when the silver nitrate was reduced by glucose versus those that were formed by reduction with hydrazine. Silver nanoparticles with average sizes of 10 and 35 nm, produced by reduction with hydrazine at 5 and 40°C, were applied to silk by an exhaust method. Silk fabrics treated with 40 ppm silver hydrosol produced at 5°C and 60 ppm silver hydrosol produced at 40°C showed 100% antimicrobial activity against the gram‐positive bacterium Staphylococcus aureus. The durability of the antimicrobial property of the treated silk fabric to washing was also examined and is presented. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
In vitro release of complexed pDNA from biodegradable polymer films
Authors: Ramgopal Y. , Venkatraman S. S. , Godbey W. T.
Published: January 2008

The controlled delivery of low‐molecular weight drugs and proteins from biodegradable polymers has received considerable attention. However, controlled release studies of pDNA from such polymers have not been reported to date. In this study, a plasmid DNA was complexed with the cationic polymer called polyethylenimine (PEI). This gene vector has been shown to be very effective in transfecting cells. The complexed DNA were then incorporated into different types of poly‐lactic‐co‐glycolic acid (PLGA) film; PLGA 53/47 (Mw 90 kDa), 50/50 (Mw 11 kDa, end group is lauryl ester) and 75/25 (Mw 120 kDa). Their release profiles from a buffer solution were studied. An initial (small) burst release of PEI‐DNA from film was observed in PLGA 53/47 and 50/50, followed by a plateau phase and finally a rapid erosion‐controlled release. For PLGA 50/50, the rapid release started after 14 days; erosion‐controlled release for PLGA 53/47 started after 9 days; for PLGA 75/25, the release rate was governed by an initial burst release (10%) followed by a slow release controlled by diffusion. No obvious erosion‐controlled release rate was observed for this polymer up to 27 days. Thus, the controlled release of complexed DNA follows the general features exhibited by lower‐ Mw drugs. This is of significance in designing gene vector matrices that offer the promise of more lasting gene therapy compared with particulate formulations. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Sulfonated poly(arylene ether ketone)s prepared by direct copolymerization as proton exchange membranes: Synthesis and comparative investigation on transport properties
Authors: Zhao Chengji , Li Xianfeng , Lin Haidan , Shao Ke , Na Hui
Published: January 2008

Sulfonated poly(aryl ether ketone)s (SPAEK) copolymers were synthesized by aromatic nucleophilic polycondensation from 3,3′, 5,5′‐tetramethyl‐4, 4′–biphenol, 1,4‐bis(4‐fluorobenzoyl) benzene, and disulfonated difluorobenzophenone. The SPAEK membranes did not exhibit excessive swelling in hot water and at the same time show the proton conductivities in the range of 0.030 S/cm to 0.099 S/cm at 80°C. The methanol diffusion coefficients of the SPAEK membranes were in the range of 4.7 × 10−7 to 8.1 × 10−7cm2/s measured at 25°C. The transport properties of this series of SPAEK copolymers were compared to poly(aryl ether ether ketone)s (SPEEK), poly(aryl ether ether ketone ketone)s (SPEEKK), and Nafion® membranes. It was found that the transport properties (including proton conductivity and methanol permeability) follows the trend of SPEEKK‐60 < SPAEK‐60 < SPEEK‐60 < Nafion® 117, the order of which is also attributed to the differences in the chemical structure of the polymers and the membrane morphology. In general, this novel series of SPAEK membranes possess various advantages, such as low cost of the initial monomers, high thermal and mechanical stability, and low methanol permeability while simultaneously possessing sufficient proton conductivity, which makes them notably promising as proton exchange membrane (PEM) materials in direct methanol fuel cell (DMFC) applications. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis of the Bicyclo[7.3.0]dodecadiyne Core of the Maduropeptin Chromophore
Authors: Iso Kentaro , Inoue Masayuki , Kato Nobuki , Hirama Masahiro
Published: January 2008

Maduropeptin, an extremely potent antitumor agent, consists of a 1:1 complex of a carrier protein and a chromophore. We report herein a general and efficient route for the synthesis of the highly strained bicyclo[7.3.0]dodecadiyne core of the chromophore. The key feature of the synthetic strategy is the use of two Sonogashira coupling reactions in a stepwise manner to construct the conjugated dienyne substructure of the fused‐ring system, including the Z alkene at C4,C13.
Total Synthesis of (−)‐Reidispongiolide A, an Actin‐Targeting Macrolide Isolated from the Marine Sponge Reidispongia coerulea
Authors: Paterson Ian , Ashton Kate , Britton Robert , Cecere Giuseppe , Chouraqui Gaëlle , Florence Gordon J. , Knust Henner , Stafford Jonathan
Published: January 2008

A stereocontrolled total synthesis of the microfilament‐destabilizing cytotoxic macrolide (−)‐reidispongiolide A, isolated from the New Caledonian marine sponge Reidispongia coerulea, is described. This synthesis utilizes a convergent aldol‐based strategy to construct the 26‐membered macrolactone, followed by the late‐stage coupling of a derived aldehyde with an N‐vinylformamide‐containing ketone subunit to install the full side chain. Two alternative routes were examined for the introduction of the 2E,4E‐dienoate region, and a complex Mukaiyama aldol coupling was used to connect the northern and southern hemispheres to install the C13 stereocenter. This constitutes the first chemical synthesis of any member of the reidispongiolide/sphinxolide family of marine macrolides and unequivocally establishes the relative and absolute configuration.
Monitoring Transport Phenomena of Paramagnetic Metal‐Ion Complexes Inside Catalyst Bodies with Magnetic Resonance Imaging
Authors: Bergwerff Jaap A. , Lysova Anna A. , Espinosa‐Alonso Leticia , Koptyug Igor V. , Weckhuysen Bert M.
Published: January 2008

An indirect magnetic resonance imaging (MRI) method has been developed to determine in a noninvasive manner the distribution of paramagnetic Co2+ complexes inside Co/Al2O3 catalyst extrudates after impregnation with Co2+/citrate solutions of different pH and citrate concentrations. UV/Vis/NIR microspectroscopic measurements were carried out simultaneously to obtain complementary information on the nature of the Co2+ complexes. In this way, it could be confirmed that the actual distribution of Co2+ inside the extrudates could be derived from the MRI images. By combining these space‐ and time‐resolved techniques, information was obtained on both the strength and the mode of interaction between [Co(H2O)6]2+ and different Co2+ citrate complexes with the Al2O3 support. Complexation of Co2+ by citrate was found to lead to a stronger interaction of Co with the support surface and formation of an eggshell distribution of Co2+ complexes after impregnation. By addition of free citrate and by changing the pH of the impregnation solution, it was possible to obtain the rather uncommon egg‐yolk and egg‐white distributions of Co2+ inside the extrudates after impregnation. In other words, by carefully altering the chemical composition and pH of the impregnation solution, the macrodistribution of Co2+ complexes inside catalyst extrudates could be fine‐tuned from eggshell over egg white and egg yolk to uniform.
Gas‐Phase Study on the CC Coupling of Naphthol Catalyzed by CuII⋅TMEDA: Evidence for the Key Role of Binuclear Clusters
Authors: Roithová Jana , Schröder Detlef
Published: January 2008

The mechanism of oxidative coupling of two naphthol molecules to form binaphthol catalyzed by Cu(OH)Cl⋅TMEDA (TMEDA=N,N,N′,N′‐tetramethylethylenediamine) was approached by means of a gas‐phase model system. Concise evidence is provided that the coupling reaction proceeds in clusters with two CuII centers, whereby the intermediacy of free naphthoxy radicals in the coupling step is avoided. In the absence of TMEDA, the cluster is bound via a bridging counterion and the coupling reaction is followed by cluster cleavage. The coordination of one or two TMEDA molecules to the reactive complex results in more efficient coupling of naphthol molecules, and moreover, the binuclear cluster is also conserved after the reaction is completed. The effect of TMEDA is twofold: First, it supports clustering of copper and, second, as a ligand bound to a copper center in the reactive complex, it weakens the bond between copper and the naphtholato ligand such that the naphtholato unit is more prone to undergo CC coupling. Furthermore, a pronounced counterion effect is found that correlates well with condensed‐phase data: weakly bridging counterions (e.g., NO3−) yield less stable dicopper clusters and the coupling reaction hardly occurs, whereas better bridging counterions (e.g., Cl− or Br−) provide more stable clusters that make the coupling reaction more efficient.
Reaction Mechanism of Apocarotenoid Oxygenase (ACO): A DFT Study
Authors: Borowski Tomasz , Blomberg Margareta R. A. , Siegbahn Per E. M.
Published: January 2008

The mechanism of the oxidative cleavage catalyzed by apocarotenoid oxygenase (ACO) was studied by using a quantum chemical (DFT: B3 LYP) method. Based on the available crystal structure, relatively large models of the unusual active‐site region, in which a ferrous ion is coordinated by four histidines and no negatively charged ligand, were selected and used in the computational investigation of the reaction mechanism. The results suggest that binding of dioxygen to the ferrous ion in the active site promotes one‐electron oxidation of carotenoid leading to a substrate radical cation and a Fe‐bound superoxide radical. Recombination of the two radicals, which can be realized in at least two different ways, yields a reactive peroxo species that subsequently evolves into either a dioxetane or an epoxide intermediate. The former easily decays into the final aldehyde products, whereas the oxidation of the epoxide to the proper products of the reaction requires involvement of a water molecule. The calculated activation barriers favor the dioxetane mechanism, yet the mechanism involving the epoxide intermediate cannot be ruled out.
ChemInform Abstract: Synthesis, Structure and Properties of Li2Rh3B2.
Authors: Bailey Mark S. , Lobkovsky Emil B. , Hinks David G. , Claus Helmut , Hor Yew San , Schlueter John A. , Mitchell John F.
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: On the Structural and Magnetic Properties of the Ternary Silicides Ce6M1.67Si3 (M: Co, Ni) and Ce5Ni1.85Si3.
Authors: Gaudin E. , Chevalier B.
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Synthesis and Structure of BaPtIn3 and BaTl0.63In3.33. Two Contrasting Examples of Preferential Site Occupation in BaAl4‐Type Structures.
Authors: Palasyuk Andriy , Corbett John D.
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Synthesis and Structures of SrAuIn and SrAuIn3.
Authors: Muts Ihor R. , Poettgen Rainer , Zaremba Vasyl I.
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Raman‐Spectroscopic Investigation of Ba2InTaO6 and Sr2InTaO6 Perovskites.
Authors: Dias A. , Khalam L. A. , Sebastian M. T. , Moreira R. L.
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: The Extended Chain Compounds Ln12(C2)3I17 (Ln: Pr, Nd, Gd, Dy): Synthesis, Structure and Physical Properties.
Authors: Ryazanov Mikhail , Mattausch Hansjuergen , Simon Arndt
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Single Crystal X‐Ray Diffraction Study of a Mixed‐Valence Gold Compound, Cs2AuIAuIIICl6 under High Pressure up to 18 GPa: Pressure‐Induced Phase Transition Coupled with Gold Valence Transition.
Authors: Matsushita Nobuyuki , Ahsbahs Hans , Hafner Stefan S. , Kojima Norimichi
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Solvothermal Synthesis of Two 2‐D Thioantimonates(III) with Metal Complexes as Template Ions, [M(dap)3]Sb4S7 (M: Ni2+ and Co2+).
Authors: Zhou Jian , Bian Guo‐Qing , Zhang Yong , Dai Jie , Cheng Na
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Facile High‐Yield Synthesis of Pure, Crystalline Mg(BH4)2.
Authors: Zanella Pierino , Crociani Laura , Masciocchi Norberto , Giunchi Giovanni
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Synthesis and Characterization of Er3SmQ6 (Q: S, Se) and Er1.12Sm0.88Se3.
Authors: Gray Danielle L. , Rodriguez Brandon A. , Chan George H. , Van Duyne Richard P. , Ibers James A.
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Two Non‐centrosymmetric Cubic Seleno‐Germanates Related to CsCl‐Type Structure: Synthesis, Structure, Magnetic and Optical Properties.
Authors: Choudhury Amitava , Polyakova Larisa A. , Strobel Sabine , Dorhout Peter K.
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Another Example for the Ability of the SbS33‐ Anion to Act as a Bidentate Ligand: Solvothermal Synthesis, Crystal Structure, Calculated and Experimental Raman Spectra of [Cr(tren)SbS3]×H2O.
Authors: Moeller Karina , Naether Christian , Bannwarth Alexander , Bensch Wolfgang
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Synthesis, Crystal Structure and Properties of RbMnO2.
Authors: Pfeiffer Steffen , Jansen Martin
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: A One‐Dimensional Organic—Inorganic Hybrid Based on the Bimolecular {[Cu(en)2]2 [Cu2Si2W22O78]}8‐ Polyoxometalate.
Authors: Wang Jing‐Ping , Du Xiao‐Di , Niu Jing‐Yang
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Development of an Electrolytic System for Non‐Kolbe Electrolysis Based on the Acid—Base Reaction Between Carboxylic Acids as a Substrate and Solid‐Supported Bases.
Authors: Tajima Toshiki , Kurihara Hitoshi , Fuchigami Toshio
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Highly Enantioselective Direct Aldol Reaction Catalyzed by Cinchona‐Derived Primary Amines.
Authors: Zheng Bao‐Lei , Liu Quan‐Zhong , Guo Chuan‐Sheng , Wang Xue‐Lian , He Long
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Synthesis and Reactivity of N‐[3‐Amino‐4‐(benzoxazol‐2‐yl)pyrazol‐5‐yl]phenylamine.
Authors: Abdelhamid Abdou O. , Baghos Victorin B. , Halim Mervat M. A.
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Scandium Triflate Catalyzed Aminolysis of meso‐Aziridines.
Authors: Peruncheralathan Saravanan , Henze Michael , Schneider Christoph
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Broensted Acid Catalyzed Formal Insertion of Isocyanides into a C—O Bond of Acetals.
Authors: Tobisu Mamoru , Kitajima Aki , Yoshioka Sachiko , Hyodo Isao , Oshita Masayuki , Chatani Naoto
Published: January 2008

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.