bluuebunny/crossref_metadata_2025 huggingface dataset:
Supercapacitors Technical Requirements for New Applications
Authors: Conte M.
Published: September 2010

The supercapacitors (SCs), also called ultracapacitors or electrochemical capacitors, are devices with a very high specific power and high capacitance, available for a long period of time with negligible deterioration, that have been historically proposed in small applications (memory back‐up in consumer electronics and storage systems for microsolar power generators) and now are proposed for high power/energy applications, such as hybrid and electric vehicles, power quality systems and smart grids. The advancements in new materials and the rapid growth of more demanding storage systems in a variety of applications have created a lack of universally accepted definitions of these devices and, consequently, a real difficulty in describing developments and progress in the SC field.

This paper contains a brief survey of the history of the SC development, which is strongly related to the evolution of the SC technologies, tentatively classified in symmetric, asymmetric and hybrid. A short presentation of key parameters has been given to introduce the description of new applications with large SC devices, covering transport, industrial and electric utility sectors, with some reflections about the foreseen impacts on the future market more than quadrupled in 5 years up to almost $877 million worldwide.
BARD1 homozygous deletion, a possible alternative to BRCA1 mutation in basal breast cancer
Authors: Sabatier Renaud , Adélaïde José , Finetti Pascal , Ferrari Anthony , Huiart Laetitia , Sobol Hagay , Chaffanet Max , Birnbaum Daniel , Bertucci François
Published: September 2010

Hereditary breast cancers (BCs) are incompletely explained by BRCA genes abnormalities, as ∼70% of them are not associated with known genetic alterations. Array‐based comparative genomic hybridization (aCGH) of tumors provides an opportunity for identifying new BC susceptibility genes. By analyzing our database of high‐resolution aCGH profiles of 330 BCs, we identified a case with homozygous deletion of the entire BARD1 gene. The BARD1‐deleted case displayed a familial history of BC and other clinico‐pathological features of BRCAness, and a 17% probability of BRCA1/2 mutation. Analysis of constitutional DNA showed a BARD1 germline heterozygous deletion without BRCA1/2 mutation. Gene expression analysis using DNA microarrays classified the tumor as basal‐like, with very low BARD1 and ID4 expression, but high expression of BRCA1, RAD51, PARP1, CHEK1, and FANCA. The tumor displayed a BRCA1‐mutated expression profile. This is the first report of a non‐BRCA1/2‐mutated BC with somatic homozygous and germ‐line heterozygous deletion of the entire BARD1 gene. This observation suggests that BARD1 might be a BC susceptibility gene that follows the Knudson rule. Identification of BARD1 deletion could have clinical applications including screening for hereditary forms. © 2010 Wiley‐Liss, Inc.
A meta‐analysis of home visiting programs: Moderators of improvements in maternal behavior
Authors: Nievar M. Angela , Van Egeren Laurie A. , Pollard Sara
Published: September 2010

A meta‐analysis of home visiting programs for at‐risk families (K= 35,N= 6,453) examined differences in the effects of programs on maternal behavior. On average, programs with more frequent visitation had higher success rates. The frequency of home visits explained significant variance of effect sizes among studies in the United States, with two visits per month predicting a small, substantive effect. Intensive programs or programs with at least three visits per month were more than twice as effective as were less intensive programs. Home visiting programs using nurses or mental health professionals as providers were not significantly more effective than were programs using paraprofessionals. In general, programs showed a positive effect on maternal behavior, but programs with frequent home visits were more successful.
Becoming their mother: Knowledge, attitudes, and practices of orphanage personnel in Ukraine
Authors: Vashchenko Maryna , Easterbrooks M. Ann , Miller Laurie C.
Published: September 2010

Institutional caregiving can have adverse effects on children, yet little is known about the caregivers of institutionalized young children. We surveyed staff in three Ukrainian Baby Homes about their attitudes toward the nature of their work and the needs of the young children in their care. Seventy‐one caregivers completed anonymous, semistructured surveys. Popular reasons for working in Baby Homes included benefits and convenient work shifts, morality, and affection for children. Caregivers reported both favorable aspects of the work (enjoyment of children, professional satisfaction) and work difficulties (conflicts, lack of cooperation, little administrative support). In addition, they noted deficiencies in care: high caregiver–child ratio, frequent care disruptions, and lack of stimulation. Direct caregivers (in‐room “nannies,” educators, and nurses) and other providers (e.g., clinic nurses, physicians, therapists) differed in university‐degree attainment, professional motivation, enjoyment of children, professional satisfaction, and perceptions of self as substitute mother. A number of potential “windows for change” were identified, including recognition of deficiencies in institutional care and possibilities for improvement. Implications for interventions are discussed, including the need to consider lack of staff support, high emotional stress, internal conflicts, beliefs and attitudes about institutionalized children and their biological parents, and differences in staff educational achievement.
Inorganic arsenite inhibits IgE receptor‐mediated degranulation of mast cells
Authors: Hutchinson Lee M. , Trinh Benett M. , Palmer Rachel K. , Preziosi Christopher A. , Pelletier Jonathan H. , Nelson Hannah M. , Gosse Julie A.
Published: September 2010

Millions of people worldwide are exposed to arsenic (As), a toxicant which increases the risk of various cancers, cardiovascular disease and several other health problems. Arsenic is a potent endocrine disruptor, including of the estrogen receptor. It was recently shown that environmental estrogen‐receptor disruptors can affect the signaling of mast cells, which are important players in parasite defense, asthma and allergy. Antigen (Ag) or allergen crosslinking of IgE‐bound receptors on mast cells leads to signaling, culminating in degranulation, the release of histamine and other mediators. Because As is an endocrine disruptor and because endocrine disruptors have been found to affect degranulation, here we have tested whether sodium arsenite affects degranulation. Using the rat basophilic leukemia (RBL) mast cell model, we have measured degranulation in a fluorescence assay. Arsenic alone had no effect on basal levels of degranulation. However, As strongly inhibited Ag‐stimulated degranulation at environmentally relevant concentrations, in a manner that is very dependent on concentrations of both As and Ag. The concentrations of As effective at inhibiting degranulation were not cytotoxic. This inhibition may be a mechanism underlying the traditional Chinese medicinal use of As to treat asthma. These data indicate that As may inhibit the ability of humans to fight off parasitic disease. Copyright © 2010 John Wiley & Sons, Ltd.
Sensitivity of superficial cultures in lower extremity wounds
Authors: Chakraborti Chayan , Le Christina , Yanofsky Andrew
Published: September 2010

BACKGROUND:

Superficial wound cultures are routinely used to guide therapy, despite a lack of clear supporting evidence.

PURPOSE:

To conduct a systematic review of the correlation between superficial wound cultures and the etiology of skin and soft tissue infections.

DATA SOURCES:

Medline, EMBASE, CINAHL, Scopus.

STUDY SELECTION:

Articles published between January 1960 and August 2009 involving superficial wound cultures and deeper comparison cultures.

DATA EXTRACTION:

Two reviewers independently searched for abstracted information pertaining to the microbiology of lower extremity wounds sufficient to calculate the sensitivity and specificity of superficial wound cultures versus comparison cultures.

DATA SYNTHESIS:

Data pooled using a random‐effects meta‐analysis model.

RESULTS:

Of 9032 unique citations, 8 studies met all inclusion criteria. Inter‐rater reliability was substantial (Kappa = 0.78). Pooled test sensitivity for superficial wound swabs was 49% (95% confidence interval [CI], 37‐61%], and specificity was 62% (95% CI, 51‐74%). The pooled positive and negative likelihood ratios (LRs) were 1.1 (95% CI, 0.71‐1.5) and 0.67 (95% CI, 0.52‐0.82). The median number of isolates for surface cultures (2.7, interquartile range [IQR] 1.8‐3.2) was not significantly different than that for comparison cultures, (2.2, IQR 1.7‐2.9) (P = 0.75).

CONCLUSION:

Few studies show a strong relationship between superficial wound swabs and deep tissue cultures, and the current data demonstrate poor overall sensitivity and specificity. The positive and negative LRs were found to provide minimal utility in influencing pretest probabilities. Results of this analysis show that wound cultures should not be used in lieu of local antibiograms to guide initial antibiotic therapies. Journal of Hospital Medicine 2010;5:415–420. © 2010 Society of Hospital Medicine.
His‐tag binding by antibody C706 mimics β‐amyloid recognition
Authors: Teplyakov Alexey , Obmolova Galina , Canziani Gabriela , Zhao Yonghong , Gutshall Lester , Jung Sonia S. , Gilliland Gary L.
Published: September 2010

Alzheimer's disease is a progressive neurodegenerative disease characterized by extracellular deposits of β‐amyloid (Aβ) plaques. Aggregation of the Aβ42 peptide leading to plaque formation is believed to play a central role in Alzheimer's disease pathogenesis. Anti‐Aβ monoclonal antibodies can reduce amyloid plaques and could possibly be used for immunotherapy. We have developed a monoclonal antibody C706, which recognizes the human Aβ peptide. Here we report the crystal structure of the antibody Fab fragment at 1.7 Å resolution. The structure was determined in two crystal forms, P21 and C2. Although the Fab was crystallized in the presence of Aβ16, no peptide was observed in the crystals. The antigen‐binding site is blocked by the hexahistidine tag of another Fab molecule in both crystal forms. The poly‐His peptide in an extended conformation occupies a crevice between the light and heavy chains of the variable domain. Two consecutive histidines (His4–His5) stack against tryptophan residues in the central pocket of the antigen‐binding surface. In addition, they form hydrogen bonds to the acidic residues at the bottom of the pocket. The mode of his‐tag binding by C706 resembles the Aβ recognition by antibodies PFA1 and WO2. All three antibodies recognize the same immunodominant B‐cell epitope of Aβ. By similarity, residues Phe–Arg–His of Aβ would be a major portion of the C706 epitope. Copyright © 2010 John Wiley & Sons, Ltd.
Low prevalence of hepatitis E infection among pregnant women in Madrid, Spain
Authors: Lindemann Maria Luisa Mateos , Gabilondo Gustavo , Romero Beatriz , de la Maza Oihane Martín S. , Pérez‐Gracia Maria Teresa
Published: September 2010

Hepatitis E virus, a cause of sporadic hepatitis in developed countries is present in Spain. The aims of this study were to determine whether the prevalence of IgG anti‐hepatitis E virus antibodies has increased in recent years in Spain and the prevalence in a study population at risk of developing the disease following the infection. Serum samples from 1,040 women in the first trimester of pregnancy were studied. The prevalence rate of 3.6% has not increased significantly since 1999 in spite of the large number of immigrants from endemic regions. IgM anti‐HEV antibodies were detected in 0.67% of the patients suggesting that although subclinical infection exists the prevalence is very low. The reasons for the differences in the morbidity of HEV in pregnant women in different geographical areas remain unclear. Good hygienic measures and public health conditions are important factors for ensuring low prevalence of hepatitis E in Spain. J. Med. Virol. 82:1666–1668, 2010. 2010 Wiley‐Liss, Inc.
Comparison of viral load and duration of virus shedding in symptomatic and asymptomatic neonatal rotavirus infections
Authors: Ramani Sasirekha , Sankaran Premi , Arumugam Rajesh , Sarkar Rajiv , Banerjee Indrani , Mohanty Ipsita , Jana Atanu Kumar , Kuruvilla Kurien Anil , Kang Gagandeep
Published: September 2010

A single rotavirus strain causing asymptomatic infections as well as severe gastrointestinal disease has been described in the neonatal nurseries of the Christian Medical College, Vellore. In this study, quantitative real‐time RT‐PCR was used to determine the association of viral load with the presence of gastrointestinal symptoms in neonates. Viral load was estimated in terms of the crossing point [C(t) value] at which the amplicon could be detected in the real‐time PCR assay. The study was carried out on 103 neonates, including 33 asymptomatic neonates and 70 neonates with different gastrointestinal symptoms. The duration of virus shedding was also compared between five symptomatic and four asymptomatic neonates using real‐time RT‐PCR. There was no significant difference in viral load between symptomatic and asymptomatic neonates (P = 0.087). Among neonates with different gastrointestinal symptoms, those presenting with feed intolerance and abdominal distension had a significantly higher viral load than those with other gastrointestinal symptoms (P = 0.02). For the study on virus shedding, nine neonates were followed up for a median duration of 53 days, with a median of 31 samples tested per child. Extended shedding of low copies of rotavirus was found, with no significant differences in pattern of shedding between symptomatic and asymptomatic neonates. The lack of correlation between viral load and gastrointestinal disease demonstrates yet another difference between neonatal rotavirus infection and infection in older children where higher viral load correlates with severe disease. J. Med. Virol. 82:1803–1807, 2010. © 2010 Wiley‐Liss, Inc.
Expression of Epstein‐Barr virus‐encodedLMP1andhTERTextends the life span and immortalizes primary cultures of nasopharyngeal epithelial cells
Authors: Yip Yim‐Ling , Tsang Chi‐Man , Deng Wen , Cheung Pak‐Yan , Jin Yuesheng , Cheung Annie Lai‐Man , Lung Maria Li , Tsao Sai‐Wah
Published: September 2010

Cell immortalization is regarded as an early and pre‐requisite step in tumor development. Defining the specific genetic events involved in cell immortalization may provide insights into the early events of carcinogenesis. Nasopharyngeal carcinoma is common among the Southern Chinese population. Epstein‐Barr virus (EBV) infection is associated closely with nasopharyngeal carcinoma. The involvement ofLMP1(an EBV‐encoded oncogene) has been implicated in the pathogenesis of nasopharyngeal carcinoma. In this study,LMP1expression, in combination with ectopic expression ofhTERT(catalytic unit of human telomerase), was shown to extend the life span of primary cultures of nasopharyngeal epithelial cells and facilitate the immortalization of one of the cell lines (NP446). This is the first report on the successful immortalization of nasopharyngeal epithelial cells involvingLMP1. The events associated with the immortalization of nasopharyngeal epithelial cells byLMP1/hTERTwere characterized. Expression ofc‐Myc,Bmi‐1, andId‐1were upregulated at an early stage of immortalization. At a later stage of immortalization, downregulation ofp21andp16expression were observed. Upregulation ofEGFRexpression and activation ofMAPKsignaling pathway were observed inLMP1/hTERT‐immortalized nasopharyngeal epithelial cells. TheLMP1/hTERT‐immortalized NP446 cells were non‐tumorigenic in immunosuppressed nude mice and retained anchorage‐dependent growth, suggesting that additional events are required for tumorigenic transformation. The ability of the EBV‐encodedLMP1, in the presence ofhTERTexpression, to extend the life span and immortalize primary cultures of nasopharyngeal epithelial cells supports the involvement of EBV infection and its viral products in the early stage of pathogenesis of nasopharyngeal carcinoma. J. Med. Virol. 82:1711–1723, 2010. © 2010 Wiley‐Liss, Inc.
Human parechoviruses in infants with systemic infection
Authors: Piñeiro L. , Vicente D. , Montes M. , Hernández‐Dorronsoro U. , Cilla G.
Published: September 2010

Human parechoviruses (HPeVs) are RNA viruses related to neonatal sepsis, meningoencephalitis and other infections in young children. Little clinical and epidemiological information is available on these viruses. HPeVs were sought in cerebrospinal fluid from 397 infants aged less than 12 months from whom a sample was obtained to exclude meningitis or encephalitis from 2006 to 2009. HPeV infections were also tested in stool samples from 271 children aged less than 3 years old with gastroenteritis from November 2008 to March 2009. HPeV detection was by real‐time polymerase chain reaction assay (region 5′UTR), followed by genotyping (region VP3/VP1). HPeVs were detected in the cerebrospinal fluid of nine infants (2.3%), one aged 6 months and eight aged 14–55 days old. All were admitted to hospital for febrile syndrome with abrupt clinical deterioration and suspected systemic infection without clear laboratory signs of meningeal inflammation. The same virus was detected in all the available nasopharyngeal aspirates, stool, and/or serum samples from each patient. At least eight of the nine cases were caused by HPeV3. HPeVs were detected in stool samples from 17 children (6.3%), the most prevalent types being types 1 and 3. In conclusion, HPeV infection is common in the Basque Country (Spain) and HPeV3 is a significant cause of hospital admission due to systemic infection in the first few months of life. In these patients, HPeVs should be investigated as part of routine tests for enterovirus. J. Med. Virol. 82:1790–1796, 2010. © 2010 Wiley‐Liss, Inc.
Impact of Smad3 loss of function on scarring and adhesion formation during tendon healing
Authors: Katzel Evan B. , Wolenski Matthew , Loiselle Alayna E. , Basile Patrick , Flick Lisa M. , Langstein Howard N. , Hilton Matthew J. , Awad Hani A. , Hammert Warren C. , O'Keefe Regis J.
Published: September 2010

Studies were performed evaluating the role of Smad3, a transcription factor mediating canonical TGF‐β signaling, on scarring and adhesion formation using an established flexor digitorum longus (FDL) tendon repair model. In unoperated animals the metatarsophalangeal (MTP) range of motion (ROM) was similar in Smad3−/− and wild‐type (WT) mice while the basal tensile strength of Smad3−/− tendons was significantly (39%) lower than in WT controls. At 14 and 21 days following repair Smad3−/− MTP ROM reached approximately 50% of the basal level and was twice that observed in WT tendon repairs, consistent with reduced adhesion formation. Smad3−/− and WT maximal tensile repair strength on post‐operative day 14 was similar. However, Smad3−/− tendon repairs maximal tensile strength on day 21 was 42% lower than observed in matched WT mice, mimicking the relative decrease in strength observed in Smad3−/− FDL tendons under basal conditions. Histology showed reduced “healing callus” in Smad3−/− tendons while quantitative PCR, in situ hybridization, and immunohistochemistry showed decreased col3a1 and col1a1 and increased MMP9 gene and protein expression in repaired Smad3−/− tendons. Thus, Smad3−/− mice have reduced collagen and increased MMP9 gene and protein expression and decreased scarring following tendon FDL tendon repair. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 29:684–693, 2011
Building a great organization
Authors: Thompson Mark , Tracy Brian
Published: September 2010

Basing their article on a World Success Survey in 110 nations to determine the key traits of leaders whose impact has lasted more than 20 years, Mark Thompson and Brian Tracy present seven key steps leaders use to build great organizations. This article includes insights from such leadership icons as Ingvar Kamprad, founder of IKEA; Alan Mulally, CEO of Ford; and Jeff Bezos, Amazon.com's founder.
Multipotent adipose stromal cells and breast cancer development: Think globally, act locally
Authors: Zhao Min , Dumur Cathy I. , Holt Shawn E. , Beckman Matthew J. , Elmore Lynne W.
Published: September 2010

It has long been appreciated that stromal cells within the breast tumor microenvironment contribute to mammary carcinogenesis. However, to date, very little is known regarding the role of local adipose‐derived stromal cells (ASCs) in the development of breast cancer. Based on pathological, epidemiological and experimental data, we postulate that breast‐derived ASCs are unique mesenchymal stem‐like cells that play a critical role in the development of breast cancer and discuss the global implications of this working model in terms of breast cancer prevention, early detection, and new targeted therapies. Mol. Carcinog. © 2010 Wiley‐Liss, Inc.
Fuzzy goal programming model: an overview of the current state‐of‐the art
Authors: Aouni Belaïd , Martel Jean‐Marc , Hassaine Amal
Published: September 2010

The standard Goal Programming (GP) model considers the aspiration levels (goals) as precise and deterministic. However, in practice, there are many decision‐making situations where the decision‐maker is not able to establish the goal values precisely. The goals fuzziness is more related to the nature of the objectives involved in the decision‐making situation. The Fuzzy Goal Programming (FGP) Model has been developed in the earliest of the 80s to deal with such situations. The concept of membership functions, based on fuzzy sets theory, has been used for modelling the goals fuzziness in the GP. The aim of this paper is to give an overview of the current state‐of‐the art regarding the FGP model. Copyright © 2010 John Wiley & Sons, Ltd.
Familial aggregation of Parkinson's disease in a multiethnic community‐based case‐control study
Authors: Shino Michael Y. , McGuire Valerie , Van Den Eeden Stephen K. , Tanner Caroline M. , Popat Rita , Leimpeter Amethyst , Bernstein Allan L. , Nelson Lorene M.
Published: September 2010

To assess the familial aggregation of Parkinson's disease (PD), we compared the cumulative incidence of PD among first‐degree relatives of PD cases and controls. We identified newly diagnosed patients with PD (n = 573) during 1994 to 1995 within Kaiser Permanente Medical Care Program of Northern California and recruited 496 cases (87%) for the case‐control study. Of 720 eligible controls matched by birth year and sex to cases, 541 (75%) agreed to participate. Information on family history of PD and other neurodegenerative diseases was obtained by in‐person structured interview. We used the reconstructed cohort approach that provides a better estimate of the risk. The cumulative incidence of PD was significantly higher among relatives of PD patients compared with relatives of controls (2.0 vs. 0.7%; relative risk (RR) = 3.4, 95% confidence interval (CI) 1.9–5.9; P = 0.0001). The degree of familial aggregation was higher among first‐degree relatives of Hispanic PD cases compared with Hispanic controls (3.7% vs. 0.4%; RR = 8.5, 95% CI 1.0–68.9) than it was among non‐Hispanic Caucasian cases and controls (2.0% vs. 0.8%; RR = 2.7, 95% CI 1.5–5.1; P = 0.02). The familial aggregation of PD was stronger among the siblings of PD cases (RR = 5.4, 95% CI 1.8–16.0) than among parents (RR = 2.7, 95% CI 1.3–5.2). The incidence and familial aggregation of PD is highest among Hispanics, warranting further studies of genetic and environmental risk factors in the Hispanic population. © 2010 Movement Disorder Society
Numerical treatment of engineering problems with uncertainties. The fuzzy set approach and its application to the heat exchanger problem
Authors: Babuška Ivo , Silva Renato S.
Published: September 2010

An important part of predicting responses with computational models is the definition of systems parameters such as material properties. The reliability of model‐based predictions depends on the quality of these data, and the knowledge of their uncertainties. When experiments cannot be performed to determine parameter values, they must be obtained from the literature, namely handbooks, standards, specification sheets, etc. This paper addresses the use of literature‐based parameters and other information for assessing uncertainty in computational predictions. The uncertainties in the data and the solution (prediction) are described in the framework of fuzzy sets. A double‐pipe heat exchanger thermal analysis problem is used to illustrate the difficulties with computational predictions when only informations from the literature are available. It is shown that the resulting uncertainties are significant and cannot be neglected. Copyright © 2010 John Wiley & Sons, Ltd.
On micro‐to‐macro transitions for multi‐scale analysis of non‐linear heterogeneous materials: unified variational basis and finite element implementation
Authors: Perić D. , de Souza Neto E. A. , Feijóo R. A. , Partovi M. , Molina A. J. Carneiro
Published: September 2010

This work describes a homogenization‐based multi‐scale procedure required for the computation of the material response of non‐linear microstructures undergoing small strains. Such procedures are important for computer modelling of heterogeneous materials when the length‐scale of heterogeneities is small compared to the dimensions of the body. The described multi‐scale procedure relies on a unified variational basis which, apart from the continuum‐based variational formulation at both micro‐ and macroscales of the problem, also includes the variational formulation governing micro‐to‐macro transitions. This unified variational basis leads naturally to a generic finite element‐based framework for homogenization‐based multi‐scale analysis of heterogenous solids. In addition, the unified variational formulation provides clear axiomatic basis and hierarchy related to the choice of boundary conditions at the microscale. Classical kinematical constraints are considered over the representative volume element: (i) Taylor, (ii) linear boundary displacements, (iii) periodic boundary displacement fluctuations and (iv) minimal constraint, also known as uniform boundary tractions. In this context the Hill‐Mandel averaging requirement, which links microscopic and macroscopic stress power, plays a fundamental role in defining the microscopic forces compatible with the assumed kinematics. Numerical examples of both microscale and two‐scale finite element simulations of elasto‐plastic material with microcavities are presented to illustrate the main features and scope of the described computational strategy. Copyright © 2010 John Wiley & Sons, Ltd.
A new numerical method for the inverse source problem from a Bayesian perspective
Authors: Yan Liang , Yang Feng‐Lian , Fu Chu‐Li
Published: September 2010

In this work, a new numerical method for the inverse problem of determining a spacewise‐dependent heat source for a parabolic heat equation is developed. We reconstruct the unknown heat source by an augmented Tikhonov regularization (a‐TR) method derived from a Bayesian perspective. The a‐TR method could determine the regularization parameter and detect the noise level automatically. Numerical results for several benchmark test problems indicate that the a‐TR method is an accurate and flexible method to determine the unknown spacewise‐dependent heat source. Copyright © 2010 John Wiley & Sons, Ltd.
Combination of the material force concept and the extended finite element method for mixed mode crack growth simulations
Authors: Häusler S. M. , Lindhorst K. , Horst P.
Published: September 2010

A novel approach to simulate crack growth within an extended finite element framework is presented. The introduced approach combines the material force concept and the extended finite element method (xFEM) that is not straight forward and faces the major problem that a crack tip node, which is required for the evaluation of the material force, is not available within an xFEM framework.

The introduced concept enables an efficient single step evaluation of the crack state and the crack growth direction based on a continuum mechanics approach and represents an alternative to the common procedure of using the stress intensity factor solution within a stress or energy‐based empirical formulation for the determination of the crack growth direction. Two different approaches are introduced that evaluate the crack tip material force within the xFEM based on a domain or contour approach, both providing equivalent results. After an evaluation of the method, a major focus is set on crack growth investigations with increased complexity, including mixed mode loading and crack interaction with other discontinuities. The influence of different evaluation parameters is studied by comparing the results with empirical, experimental and alternative numerical solutions and confirms the applicability and capability of the proposed combination of both concepts. Copyright © 2010 John Wiley & Sons, Ltd.
Carbonization of electrospun poly(acrylonitrile) nanofibers containing multiwalled carbon nanotubes observed by transmission electron microscope with in situ heating
Authors: Prilutsky Sabina , Zussman Eyal , Cohen Yachin
Published: September 2010

Composite nanofibers with 5% w/w multiwalled carbon nanotubes (MWCNTs) in polyacrylonitrile (PAN) were fabricated using the electrospinning technique. Morphological development during the carbonization process was characterized by transmission electron microscopy (TEM) with in situ heating. It was found that the orientation of graphitic layers increases with temperature and does not change significantly with time during our TEM measurement, except the 750 °C. In the heating stage at 750 °C noticeable enhancement of orientation with time was observed. The presence of embedded CNTs enhances the order of the formed graphitic structures even when the CNTs are irregular or entangled. The results indicate that embedded MWCNTs in the PAN nanofibers nucleate the growth of carbon crystals during PAN carbonization. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2010
Autoinhibition of GEF activity in intersectin 1 is mediated by the short SH3‐DH domain linker
Authors: Kintscher Carsten , Wuertenberger Silvia , Eylenstein Roy , Uhlendorf Theresia , Groemping Yvonne
Published: September 2010

Intersectin 1L (ITSN1L) acts as a specific guanine nucleotide exchange factor (GEF) for the small guanine nucleotide binding protein Cdc42 via its C‐terminal DH domain. Interestingly, constructs of ITSN1L that comprise additional domains, for instance the five SH3 domains amino‐terminal of the DH domain, were shown to be inhibited in their exchange factor activity. Here, we investigate the inhibitory mechanism of ITSN1L in detail and identify a novel short amino acid motif which mediates autoinhibition. We found this motif to be located in the linker region between the SH3 domains and the DH domain, and we show that within this motif W1221 acts as key residue in establishing the inhibitory interaction. This assigns ITSN1L to a growing class of GEFs that are regulated by a short amino acid motif inhibiting GEF activity by an intramolecular interaction. Moreover, we quantify the interaction between the ITSN1L SH3 domains and the Cdc42 effector N‐WASP using fluorescence anisotropy binding experiments. As the SH3 domains are not involved in autoinhibition, binding of N‐WASP does not release inhibition of nucleotide exchange activity in kinetic experiments, in contrast to earlier observations.
Catalyst preparation with ball milling for catalytic synthesis of coiled carbon nanotubes
Authors: Fejes Dóra , Forró László , Hernadi Klara
Published: September 2010

The aim of our experiments was the production of helically coiled carbon nanotubes selectively. The influence of catalytic particles prepared by ball milling (dry and wet method) was investigated on the growth of coiled carbon nanotubes under CVD conditions. For qualitative characterization of carbon deposit on the surface, the products were imaged by transmission and scanning electron microscopy (TEM, SEM). The activity of each catalyst sample was characterized by carbon yield.

magnified image

HRTEM image of helically coiled carbon nanotube.
Rims of carbon nanotubes – influence of chirality
Authors: Dumlich Heiko , Reich Stephanie
Published: September 2010

We study the possible configurations of the open ends (rims) of carbon nanotubes. There are many possible rim structures for a given chirality (n,m). The rim configuration depends to a large extend on the atomic species and shape of its host material. We develop formulas to derive the number of armchair and zigzag‐type dangling bonds contained in a specific rim configuration. Armchair and zigzag‐type dangling bonds form different barriers at the interface between a carbon nanotube and a host material. Reshaping the rim to a desired configuration allows to change the properties of the nanotube, e.g. transport barriers, which might be interesting for producing tailored NEMS or carbon nanotube based composites.
Dissociation of water on a palladium nanoparticle
Authors: Papas Brian N. , Whitten Jerry L.
Published: September 2010

Ab initio SCF‐CI theory has been used to examine the interactions of a single water molecule with a 31‐atom nanocluster of palladium. Calculations are performed on singly‐charged cationic and anionic particles in addition to the neutral system to determine effects of charging on the adsorption energy of water and the barriers to dissociation. Penetration of the dissociated H through the surface layer into an interstitial subsurface site is also examined. Adsorption energies of an intact water molecule fall in the range 0.2–0.8 eV, while the barrier to dissociation into a subsurface site is in the range 1.4–2.1 eV depending on the charge of the metal particle. Calculations on the photoinduced dissociation of water adsorbed on the Pd surface are also reported, and dissociation pathways with smaller energy barriers than found for the ground state are shown to exist. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
L'acide Sulfoglutaconique
Authors: van der Zanden J. M.
Published: September 2010

En partant de l'acide β‐chloroglutaconique et aussi de l'acide glutinique, on a préparé l'acide β‐sulfoglutaconique; les produits sont identiques (point de fusion, les sels dipotassique, dibarytique et triargentique).

L'acide β‐chloroglutaconique a été obtenu suivant des modes de préparation connus. Le point de fusion était de 141‐142° (litt. 129°). II a été rendu probable que nous avons affaire à la forme cis.

La préparation de l'acide glutinique a été simplifiée. Le produit fond à 158.5° (litt. 145‐146°).
Die Mikrogasanalyse von Argon‐Stickstoff Mischungen
Authors: van Liempt J. A. M. , van Wijk W.
Published: September 2010

Beschreibung einer Apparatur, mit der kleine Volumina Argon‐Stickstoff quantitativ analysiert werden können.
Synthese von Glyceriden mit Hilfe von Tritylverbindungen
Authors: Verkade P. E. , van der Lee J. , Meerburg L. W.
Published: September 2010

In einer früheren Abhandlung haben wir eine Synthese von zweisäurigen Diglyceriden beschrieben. Durch Einwirkung eines Acylchlorids bei Zimmertemperatur in Gegenwart von Chinolin oder Pyridin lassen sich hieraus in sehr guter Ausbeute reine dreisäurige Glyceride herstellen. Die Brauchbarkeit dieses Verfahrens wird in dieser Abhandlung an der Herstellung der drei Myristyl‐palmityl‐stearylglycerole gezeigt. Die Bedeutung dieser Synthese dreisäuriger Glyceride für die weitere Entwicklung der Fettchemie wird auseinandergesetzt.
Derivatives of the oxidation products of glycerol
Authors: den Otter H. P.
Published: September 2010

The aim of this investigation on the oxidation of glycerol, was to discover a method of preparing dihydroxyacetone in higher yields than obtained by E. Fischer and J. Tafel

Ber. 20, 3384 (1887).

) by purely chemical means. The literature on the purely chemical oxidation of glycerol is very voluminous

See dissertation, pp. 19, 20 and 21.

).

The oxidation of glycerol was examined with hydrogen peroxide and ferrous sulphate, with alkaline hypochlorite solution using cobalt acetate as catalyst, with bleaching powder and cobalt acetate and with bromine and soda. The latter method afforded crystallised dihydroxyacetone. Various hydrazones and osazones of this compound were prepared. Some of the osazones of dihydroxyacetone could only be obtained by first oxidising it to hydroxypyruvic aldehyde and reacting the latter with the appropriate substituted hydrazines.

Various osazones of glyoxal were also prepared.
The diffusion of an electrolyte
Authors: Hermans J. J.
Published: September 2010

I. Theoretical part: The diffusion of an electrolyte is due to a tendency of the ions to move towards points of lower concentration, while their charge causes a gradient of potential which makes both ions move with the same average velocity. The above mentioned tendency can be described by a “Penetrationsdruck” which depends on the concentration of the electrolyte. Moreover attention must be paid to the mutual influence of motions, which can be treated in a very general way by means of hydrodynamical considerations.

The theory leads to a formula for the diffusion coefficient and for the diffusion potential. The latter has been compared with experiments mentioned in the literature.
The bromination of quinoline, isoquinoline, thiazole and benzthiazole in the gaseous phase
Authors: Jansen H. E. , Wibaut J. P.
Published: September 2010

The bromination of quinoline in the gaseous phase at 450‐500° results in the formation of 2‐bromoquinoline, the yield being sufficient for preparative work. If the bromination is carried out at 300°, 3‐bromoquinoline is formed. The influence of temperature on the course of the substitution reaction is therefore analogous to that previously found with pyridine.

The bromination of isoquinoline at 450° gives a small yield of 1‐bromo‐isoquinoline. The bromination of thiazole at both 250° and 450° gives 2‐bromothiazole.

The bromination of benzthiazole at 450° is analogous to that of quinoline.

The hydrogen atoms of the benzene nucleus of benzthiazole are not substituted and the bromine atom enters the thiazole ring at the only available position, namely the 2‐position. The 2‐bromobenzthiazole so formed may also be prepared from 2‐aminobenzthiazole.
On the system water‐sulphur trioxide
Authors: Snethlage H. C. S.
Published: September 2010

The values of E and log. A in kT = A e ‐E/RT. which have been published for the oxidation of succinic acid with chromic acid in sulphuric acid of varying strength, allow one to calculate kT for any temperature. The maximum which was found in the kT‐acid concentration curve must show a shift to lower sulphuric acid concentrations with decrease of the temperature. At −40° it is found very near to the composition SO3 3 aq. This, and the fact that the speed of oxidation increases rapidly with the acid concentration as soon as the composition SO3 5 aq. has been reached, leads to the conclusion that SO3 3 aq. is one of the active components of the system. Comparison of the speed of decomposition of chromic acid, the speed of oxidation of organic substances and the speed of decomposition of organic substances by sulphuric acid, leads to the conclusion that a second hydrate, probably 2 SO3 1 aq. is active too. It is known that reactions which are dependent on the concentration of this substance have an abnormally high temperature coefficient. The superposition of the effects caused by these two hydrates explains the behaviour of solutions of sulphuric acid in water at different temperatures in a number of cases.
The basic properties of orthophosphoric acid
Authors: Arlman E. J.
Published: September 2010

On adding together H3PO4 and HClO4 a substance of the composition H3PO4. HClO4 is formed with a melting point of 46°‐47°. It is shown by the electrolysis of its solution in CH3NO2 that the H3PO4 forms a positive ion, from which follows that H3PO4 has basic properties towards the strong acid HClO4. The reaction:

may be compared with the reaction:
Die Struktur einiger Kristallisierten Antimonate
Authors: Beintema J.
Published: September 2010

Die Koordinationszahl des fünfwertigen Antimons in seinen Sauerstoffverbindungen, wie sie aus dem Verhältnisse der Ionenradien des fünfwertig positiven Antimons und des zweiwertig negativen Sauerstoffs abgeleitet werden kann, ist sechs. In Zusammenhang damit nimmt Pauling 1) an, dass die Antimonate als Salze der hypothetischen Säure HSb(OH)6 aufzufassen seien.

L. Pauling, J. Am. Chem. Soc. 55, 1895 (1933)

Um die Richtigkeit dieser Hypothese zu prüfen, wurden einige kristallisierten Antimonate röntgenographisch untersucht. Es konnte dabei gezeigt werden, dass wenigstens die kristallisierten Antimonate des Natriums (das sogenannte “Natriumdihydropyrostibiat”), des Magnesiums, des Nickels, des Kobalts und des komplexen Kations: {Cu(NH3)3(H2O)3}” in der Tat das Ion {Sb(OH)6}' enthalten. Auch im Falle des Bariumantimonats konnte diese Struktur der Antimonationen wahrscheinlich gemacht werden.

Das Triaquo‐triamino‐Kupferantimonat zeigt eine bemerkenswerte Parallelverwachsung, die der von Bijvoet und Nieuwenkamp2) beim CdBr2 gefundene “Wechselstruktur” einigermassen ähnlich ist. Für diese Erscheinung wurde der Name , Intrataxie” vorgeschlagen.

Auch bei der triklinen Modifikation des Magnesium‐ und des Kobaltsalzes muss eine derartige “Intrataxie” wahrscheinlich angenommen werden

J. M. Bijvoet und W. Nieuwenkamp, Z. Krist. 86, 466 (1933)

)
The Raman spectrum of sulphur dioxide in different states
Authors: Gerding H. , Nijveld W. J.
Published: September 2010

The influence of the state of matter on the three vibrations of sulphur dioxide has been studied.

For that reason the Raman spectra of gaseous SO2 at 12 atmospheres, of liquid SO2 at 40° and 70°, of solutions of SO2 in water and of mixtures of SO2 with CCl4 (and SO3) were investigated.

The difference between
equation image
gas and
equation image
liquid for the strongest Raman line of SO2, is equal to 6 cm−1. This is to be ascribed to the action of the electrostatic fields of the dipole molecules in the liquid.

For solutions in water (at 50°), the dissolved SO2 is in a state comparable with the gaseous one. The concentration of H2SO3 in the solution can only be small.

For the mixtures only small displacements of the Raman lines have been The spectrum of the mixtures consists in first approximation of a superposition of the spectra of the two components.

The experimental arrangement used, is described in detail.
Zur Silberkeimtheorie des Latenten Bildes: Die Kritische Keimgrösse
Authors: Reinders W. , de Vries R. W. P.
Published: September 2010

Die Untersuchungen von Reinders und Hamburger über die physikalische Entwicklung von Silberschichten subatomarer Dicke, welche durch Sublimation im Hochvakuum auf Glasunterlage hergestellt waren, wurden wiederholt und erweitert.

Die Grenze der Entwicklungsfähigkeit wurde bei einer Schichtdicke von etwa 0.002 Atomen gefunden. Die Entwicklungsfähigkeit steigt sehr rasch mit der Schichtdicke.

Unter den normalen Umständen der Entwicklung (Δ E =εAg‐ε Red ungefähr 0.200 bis 0.250 Volt) sind isolierte Atome, Doppelatome und 3‐Aggregate nicht entwickelbar. Erst Aggregate von 4 und mehr Atomen sind keimfähig.
Les Acétales Cycliques de Quelques Combinaisons Mono‐ et Dicarbonylées
Authors: Böeseken J. , Tellegen F.
Published: September 2010

Nous avons étudié la préparation des acétales *) cycliques de quelques mono‐ et bi‐cétones. La butanedione‐2,3 (diacétyle) donne un mono‐acétale pentacyclique, un diacétale pentacyclique (p. d. f. 30°–31°) et un diacétale hexacyclique (p. d. f. 90°–91°). Les structures de ces acétales furent démontrées. La méthode de préparation fut presque toujours l'addition d'acide sulfurique concentré.
Sur les Polymères du Méthylchavicol
Authors: van der Zanden J. M.
Published: September 2010

Le chauffage du méthylchavicol, CH3O. C6H4. CH2. CH: CH2, à 250° a donné naissance à un mélange de polymères, d'oùG nous avons isolé, à l'état pur et cristallisé, trois dimères et un trimère.

L'un de ces dimères est le 1,6‐di‐p‐méthoxyphénylhexène‐1.

Nous avons établi sa structure, en étudiant la transposition‐Beckmann de l'oxime d'un acide cétonique, qu'on obtient entre autres produits, en oxydant le dimère.

Nous avons synthétisé cet acide cétonique, l'acide γ‐anisoyl‐n. butyrique et également l'acide δ‐p‐méthoxyphényl‐n.valérique, qui prend naissance comme produit primaire dans l'oxydation du polymère et qui, par une Oxydation plus énergique engendre l'acide cétonique. Enfin nous avons vérifié et également l'acide δ‐p‐méthoxyphényl‐n. valérique, qui prend naissance qu'on obtient également par hydrogénation du dimère.
Zur Kenntnis der Diterpene 37. Mitteilung: Über die Lage der Carboxylgruppe im Ringe A der Agathen‐disäure
Authors: Ruzicka L. , Jacobs H.
Published: September 2010

Die in den Agatho‐Kopalen vorkommende Agathen‐disäure ist wahrscheinlich ein regelmässig gebautes Diterpen, in welchem die Lage einer Methylgruppe und eines Carboxyls noch nicht genau bekannt war. Nach Methoden, die sich bei der Aufklärung der Abietinsäure bewährt hatten, wurde die Ortsbestimmung dieses Carboxyls durchgeführt.
Nouvelles recherches experimentales sur la configuration des antipodes optiques de substances differentes
Authors: Timmermans Jean
Published: September 2010

L'étude desracémiques actifspermet de classer les antipodes de différentes substances en deux séries de configuration antagoniste, correspondant l'une à l'acide tartrique d. et l'autre à l'acide l.; l'auteur compare les résultats obtenus de cette manière à ceux déduits d'autres considérations par Kuhn et Freudenberg.
Preparation and reactions of mono‐ and dihydroxycholestanes
Authors: Heilbron I. M. , Shaw W. , Spring F. S.
Published: September 2010

The preparation of 4:5‐ and 5:6‐dihydroxycholestanes by hydration of Δ4− and Δ5‐cholestene oxides respectively is described; dehydration of the two diols gives either the parent oxide or cholestadiene the structure of which is discussed in the light of the reactions employed.
Transformations of esters of unsaturated fatty acids with hydrogenation catalysts in the absence of hydrogen
Authors: Waterman H. I. , van Vlodrop C.
Published: September 2010

Catalytic hydrogenation of the esters of unsaturated fatty acids is often accompanied with isomerisation‐reactions.

Isomerisation occurs also during the heating of esters of unsaturated fatty acids with hydrogenation catalysts in the absence of hydrogen. Therefore this isomerisation has not to be considered especially as a process dependent on the hydrogenation.

The isomerisation of oleic acid ethyl ester was carried out with nickelkieselguhr‐catalyst at 290° C. An elaidination process takes place which could be followed by the iodine equilibrium constant method of van der Steur.
Studies on sesamine II
Authors: Cohen W. D.
Published: September 2010

Through careful degradation of dibromosesamine it has been possible to divest the sesamine‐molecule of its aromatic portion and a compound has been isolated, although in a small yield, which can be considered as the double cyclic acetal of 3.4‐dihydroxyhexane‐ 1.6‐di‐al. As a result, the structural formula of sesamine formerly proposed, which was still somewhat ambiguous, especially as regards the aliphatic part of the molecule, now becomes more probable.
The estimation of glycerol and some other hydroxylated compounds
Authors: Bertram S. H. , Rutgers R.
Published: September 2010

A method has been worked out for the estimation of glycerol by means of a complex copper compound. The failure of other methods on the same lines is ascribed to some properties of this compound and the mistakes made previously are avoided by working in alcoholic solution.

Proofs are provided of the accuracy of the results obtained. In contrast with other methods, the estimation is very quick, does not involve a preliminary purification for most of the glycerol containing liquids met with, does not estimate impurities such as trimethyleneglycol and sugars, and yields true results.

The possibilities of adapting the method to mannitol, sorbitol, tartaric acid, etc. are outlined.