bluuebunny/crossref_metadata_2025 huggingface dataset:
Association between aluminum and iron exposure in maternal blood and umbilical cord blood and congenital heart defects in children
Authors: Li Jing , Zhang Chunhua , Mao Baohong , Liu Qian , Wang Yanxia , Yi Bin , Liu Qing
Published: January 2024

Background

Congenital heart disease (CHDs) is the major cause of mortality from birth defects, affecting up to 1% of live births worldwide. However, the relationship between aluminum (Al) and iron (Fe) levels and the risk of CHDs has yielded inconsistent results.

Methods

We conducted a pair-matched case–control study that included 97 CHDs and 194 non-CHDs to investigate the association and interaction between Al/Fe exposure and the risk of CHDs in a birth cohort study in Lanzhou, China.

Results

Higher concentrations of cord blood Al were associated with a greater risk of total CHDs (aOR = 2.826, 95% CI [1.009–7.266]) and isolated CHDs (aOR = 10.713, 95% CI [1.017–112.851]) compared to the lowest Al level. Both in maternal blood and cord blood, a significant dose-effect was observed between Al level and total CHDs (Ptrend < 0.05), but a similar pattern was not observed for Fe. High Al in addition to high Fe appeared to elicit a stronger association with CHDs than both lowest tertile of Al and Fe level in umbilical cord blood, particularly for multiple CHDs, septal defects and patent ductus arteriosus.

Conclusions

Our study suggests that exposure to Al during pregnancy (≥2,408 μg/L) is significantly associated with an increased risk of CHDs in offspring, especially septal defects, and that high levels of Al and Fe are strongly correlated with fetal heart development. Further research is needed to understand the underlying mechanisms.
Spinal Anaesthesia Success: An Observational Study Assessing Subjective Sensations During Spinal Anaesthetic Drug Injection
Authors: Patil Sandip Krishnaraj , Rawate Supriya Praful , Punamiya Zeenal
Published: January 2024

Introduction: Spinal Anaesthesia (SA) has stood as the most favoured and dependable technique in regional anaesthesia for the past century. However, despite its widespread use, there are instances of occasional SA failure. Currently, there is no straightforward, cost-effective, and easily administered real-time test-aside from the positive aspiration of Cerebrospinal Fluid (CSF)-that can reliably confirm the deposition of local anaesthetic in the subarachnoid space. Aim: To evaluate the predictive value of subjective sensations (warmth/tingling/numbness) during the administration of SA for enhancing success rates. Materials and Methods: A prospective observational study preceeded the recruitment of 500 patients for this investigation. Following the confirmation of CSF aspiration upon injecting the SA drug, Bupivacaine, patients were queried about the sensations of warmth and/or tingling numbness in the lower limb, saddle part, and inner thighs. This assessment was conducted at 30 seconds and one minute after injection. Additionally, patients were asked to report any increase in the area and/or intensity of these sensations. The adequacy of SA was determined by achieving a sensory block upto the desired dermatome level and reaching a Bromage scale score of IV. Evaluations were performed at two minutes, five minutes, 10 minutes, and 15 minutes from the initiation of SA. Results: The population, predominantly ASA Class-I (60%) and II (40%), exhibited a median age of 45 years, with 54% being male. Intraoperative vital signs, including Heart Rate (HR), Systolic Blood Pressures (SBP), and Diastolic Blood Pressures (DBP), showed a consistent declining trend post-SA administration. Efficacy assessments revealed that Bromage Grade-IV was achieved in 99% of patients at 15 minutes. Notably, subjective sensations of warmth, tingling, and/or numbness proved to be robust predictors of successful SA, with a 218-fold increased likelihood. The diagnostic model demonstrated a high sensitivity of 98%, specificity of 85%, and a Positive Predictive Value (PPV) exceeding 99%. Conclusion: This study highlights the crucial role of warmth, tingling, and numbness as reliable indicators for successful SA, supported by a robust 97% success rate. Incorporating these patient-reported sensations in assessments provides a practical and accessible approach to improve the efficacy of SA procedures.
The Potential of Katmon Fruit (Dellenia philippinensis) Extract as a Natural Food Preservative
Authors: Pormento Cecelio C.
Published: January 2024

This study investigates the potential of Katmon fruit (Dellenia philippinensis) extract as a natural food preservative. The methodology encompassed the extraction of key components from the fruit and their subsequent Analysis. Computational evaluations, based on data from Tables 1, 2, and 3, reveal a significant correlation between the acetic acid concentration in the extract and its antimicrobial effectiveness. Results demonstrate the extract's substantial capability to inhibit microbial growth, which is attributed to its high antioxidant and acetic acid content. Sensory evaluations suggest the extract does not compromise food quality. The discussion underscores the advantages of Katmon fruit extract over synthetic preservatives, highlighting its natural, cost-effective, and eco-friendly nature. The study adds to the understanding of natural food preservation, proposing a viable alternative to synthetic additives, with implications supported by computational data analyses.
Evaluation of Extractants for Determination of Micronutrients in Soils of South Gujarat, India
Authors: Vajer Prashant , Zinzala V. J. , Singh Narendra , Sisodiya R. R.  , Patel V. A. , Vasave J. B.
Published: January 2024

An experiment was conducted at Department of Soil Science and Agricultural Chemistry, Navsari Agricultural University during the year 2018-19. The methods of micronutrients determination were (i) extracted through diethylene triamine penta acetic acid (DTPA) (ii) extracted through ammonium bicarbonate- diethylene triamine penta acetic acid (AB-DTPA) (iii) extracted through Neubauer. The methods of micronutrients were evaluated through method validation parameters like linearity, sensitivity of instruments, precision and predictability. The available micronutrients determined from the sample soils were correlated with soil physico-chemical properties to know the relationship of these properties with available micronutrients. The linearity study of the series of micronutrients standard were measured through different methods of micronutrient determination. These measured values showed linear relationship with reference values. The coefficient of determination (R2) for all the methods was > 0.90. The precision was determined by relative standard deviation (RSD) (%) of different micronutrient methods which were in the range of 1.834 to 19.11 %. All the studied methods of copper, iron, zinc and manganese determination, AB-DTPA extractant method has highly significant and positive correlation with nutrient uptake by wheat on Microwave Plasma Atomic Emission Spectroscopy (MP-AES) instrument. Organic C and sand content of soil have positive correlation with micronutrients availability. While pH, EC, CEC, CaCO3, silt and clay content of soil have negative correlation with available micronutrients.
Mobile Payment Applications in Countries with Low Financial Inclusion: A Multi-stakeholder Perspective Review
Authors: Stephen B. U.  , Archibong E. E.  , Asuquo P. M.
Published: January 2024

Aims: Mobile payment apps have become the most used mobile payment system, especially in underbanked regions. It has come be the most viable way of promoting access to and use of quality financial services, at affordable cost. As far as review works on use/adoption of mobile payment apps in low financial inclusion countries go, presentation has been from users’ perspective. Thus, under-emphasizing the challenges of other members of the m-payment app ecosystem. The work aims at describing such general challenges from the lenses of users, regulators and merchants of mobile payment apps. Also, pros and cons of some specific mobile payment apps in these regions are also provided in the work.
Place and Duration of Study: The review covered literature covering m-payment adoption in low financial inclusion countries i.e. Asian and African countries, spanning 2015 to 2023.
Methodology: In selecting the literature, we considered only journal publications considering specifically m-payment apps, and written in English. To achieve a measure of spread, major regions in the two continents were considered, and journal articles focusing on a particular country were limited to two.
Conclusion: We observe that the challenges of m-payment apps from users’ perspective are mostly denser than other perspectives. Users’ and regulators’ concerns converge only so thinly. Only regulators’ task of enlightenment of users/customer of about demonetization policies mirrors one of users’ concerns, perceived trust. Users and merchants are both concerned with perceived risk and perceived ease of use concerns. The challenges of regulators as regards m-payment apps are quite dissimilar to those of merchants. In all, the observed disparate (or thin similarity of) concerns of the different m-payment app stakeholders strengthens the need for such an inclusive review done in this work.
ANÁLISE DA PRODUÇÃO CIENTÍFICA DAS PLACAS SOLARES FOTOVOLTAICAS EM TELHADOS
Authors: Costa Guimarães Daiane , Ferreira da Conceição Flávio , Leitão Russo Suzana
Published: January 2024

O crescimento populacional acarreta aumento da demanda de energia, contribuindo para a escassez dos recursos naturais. O uso das fontes de energias renováveis surge como uma solução para amenizar a pressão sobre esses recursos. A opção por um sistema de placas solares fotovoltaicas insere-se numa política estratégica de desenvolvimento sustentável, tendo como principais objetivos a opção de uma solução viável do ponto de vista econômico, bem como do ponto de vista social, com impacto bastante positivo para que as pessoas tenham consciência da necessidade de optar cada vez mais pelas energias renováveis. Dessa forma, o objetivo deste trabalho foi analisar e mapear os trabalhos publicados sobre placas solares fotovoltaicas em telhados por meio da produção cientifica da base Scopus. Foram utilizadas as expressões cell solar e roof com o operador booleano and a fim de delimitar as pesquisas especificamente em placas solares fotovoltaicas em telhados entre 2018 e 2021, em que foram identificadas 310 publicações no total. A China aparece como o país mais atuante e o Brasil ocupa o 35º lugar no ranking de publicações. Percebeu-se que os autores mais efetivos, com relação à quantidade, não estão presentes nos trabalhos mais citados. Concluiu-se que a pesquisa em placas solares fotovoltaicas em telhados vem crescendo, mas o Brasil ainda não ocupa posição de destaque dentro da temática. Observou-se também a importância da pesquisa da produção científica, a qual pode auxiliar no embasamento bibliográfico e oportunizar pesquisa em locais onde a placas solares fotovoltaicas em telhados ainda é pouco difundida.
ANÁLISE DOS DETERMINANTES DO ACESSO AO SERVIÇO DE COLETA DE RESÍDUOS SÓLIDOS PELA POPULAÇÃO DE BAIXA RENDA NO BRASIL
Authors: Da Silva Faria Marco Túlio , Queiroz Marina Muniz de , Aristides Victor Rossoni Hygor , Moreira Hadad Renato , Aparecida Figueiredo Gomes Uende
Published: January 2024

Apesar do manejo de resíduos sólidos domiciliares ser componente do saneamento básico, conforme estabelecido pela Lei Federal nº 11.445/2007, apenas 58,6% da população brasileira têm acesso adequado a esse serviço. Essa porcentagem é ainda mais alarmante para as áreas rurais, onde apenas 23,6% da população possui acesso adequado ao manejo de resíduos sólidos. Este artigo tem como objetivo descrever quantitativamente os determinantes envolvidos no acesso ao serviço de coleta de resíduos sólidos na parcela da população de baixa renda no Brasil, analisando fatores relacionados aos chefes de família, ao domicílio dos entrevistados e ao município onde esse se localiza, por meio de um modelo hierárquico de regressão logística. Os resultados obtidos permitiram traçar o perfil daqueles que não têm acesso ao serviço de coleta de resíduos sólidos, evidenciando que, entre a população em situação de baixa renda, as famílias mais excluídas são as extremamente pobres, da região Norte do Brasil, em áreas rurais, nos municípios de pequeno porte e que possuem o chão de terra como material predominante no piso dos domicílios em que residem. O modelo sugere que, entre a população em situação de baixa renda, as características dos chefes de família são menos relevantes do que as características dos domicílios para explicar a presença do serviço de coleta. Ressalta-se ainda a importância da localização da residência, uma vez que o modelo indica que famílias em áreas urbanas têm aproximadamente 43 vezes mais chances de terem acesso ao serviço de coleta de resíduos sólidos do que aquelas que residem em áreas rurais.
APLICAÇÃO DA CURATELA COMO MEDIDA PROTETIVA EXTRAORDINÁRIA À LUZ DA LEI BRASILEIRA DE INCLUSÃO
Authors: Ferreira de Oliveira Teresa Cristina , Silva Victor Machado Pereira da Silva
Published: January 2024

Este artigo tem como objetivo geral analisar a aplicação da curatela como medida protetiva extraordinária em consonância com a Lei 13.146/2015, também conhecida como Estatuto da Pessoa com Deficiência (EPD) ou Lei Brasileira de Inclusão (LBI), demonstrando a mudança paradigmática promovida pela LBI que passou a conferir capacidade plena para todas as pessoas, desvinculando a associação instantânea entre deficiência e incapacidade civil. Ressaltam-se as alterações promovidas no Código Civil de 2002 e como o procedimento de interdição e curatela foram modificados, de forma a refletir a Dignidade da Pessoa Humana, busca-se apontar para novos traços do instituto protetivo da curatela, como seu caráter excepcional e proporcional. Concluiu-se que a curatela, em seus moldes atuais, apesar de ser um instituto vocacionado à conservação do patrimônio do incapaz, preserva sua dignidade à medida em que confere autonomia existencial para ele. A excepcionalidade da curatela decorre do princípio da plena capacidade da pessoa com deficiência, legado da LBI, sendo a restrição da capacidade civil sempre uma medida extraordinária, pois depende de prova irrefutável nos autos do processo judicial
COBERTURA POR PLANOS DE SAÚDE DO CONGELAMENTO DE ÓVULOS E A MATERNIDADE TARDIA:
Authors: De Almeida Chamusca Açucena
Published: January 2024

RESUMO: Artigo destinado à análise da relação entre os direitos reprodutivos e a técnica de congelamento de óvulos como forma de efetivar o direito ao livre planejamento familiar. Tem-se como objetivo evidenciar que o adiamento voluntário da maternidade, através do social egg freezing, é um meio de assegurar o planejamento familiar. Discute-se a (im)possibilidade de cobertura por planos de saúde, tendo em vista as disposições contidas nas Leis nº 9.263/1996, 9.656/1998 e 11.935/2009, bem como os limites do poder regulamentador da ANS na elaboração da RN nº 465, sendo avaliado também o entendimento atual do STJ acerca do tema. Ante o reconhecimento dos direitos reprodutivos como direitos fundamentais, é necessário analisar a ambiguidade existente entre a Lei dos Planos de Saúde e as normas regulamentadoras editadas pela ANS. Quanto aos aspectos metodológicos, o método utilizado foi o hipotético-dedutivo. A construção da pesquisa se deu majoritariamente a partir de levantamento teórico e bibliográfico.

Palavras-chave: Planejamento familiar; Direitos reprodutivos; Congelamento social de óvulos; Maternidade tardia; Planos de saúde.
DOAÇÃO DE ASCENDENTE PARA DESCENDENTE: ANTECIPAÇÃO DE HERANÇA E NÃO DE LEGÍTIMA
Authors: Cunha Leandro Reinaldo da
Published: January 2024

O objetivo de igualdade faz-se presente também no âmbito sucessório, havendo a previsão legal de que, salvo disposição expressa em contrário, os herdeiros acessem montantes iguais da herança do falecido, estabelecendo, com esse fim, que atos que importem em antecipação de herança sejam considerados no momento do inventário exatamente para evitar essa disparidade. O art. 544 do Código Civil expressamente considera que a doação realizada de ascendente para descendente importa em adiantamento da herança, contudo ainda segue-se considerando tais liberalidades como se fossem antecipações de legítima, conforme preconizado no Código Civil de 1916. Tal impropriedade técnica enseja consequências que podem impactar tanto aos herdeiros como a terceiros
DIVÓRCIO E O DIREITO PROCESSUAL CIVIL BRASILEIRO
Authors: Ferreira Leal Raniella
Published: January 2024

A igualdade de gênero é um debate histórico que tem proporcionado reflexões sobre a naturalização do comportamento cultural de dominação da mulher e no contexto do Código de Processo Civil (CPC), foram necessários quase 42 anos para se retirar, do contexto do divórcio, uma vulnerabilidade inadequada à figura feminina. Ocorre que, considerando que o processo legislativo pode proporcionar, na prática, a vontade dos representantes e não dos representados, por meio de uma revisão bibliográfica e análise crítica, o presente artigo objetiva investigar em que medida a alteração do CPC, acerca do divórcio, proporcionou uma igualdade de gênero. Como resultado, destaca-se que o CPC não avançou o suficiente e não proporcionou igualdade de gênero de maneira efetiva.
CIVIL-MILITARY COOPERATION AND GENDER PERSPECTIVES
Authors: Titko Elvira , Kurovska Ilona , Korniienko Petro , Balzhyk Irena A. , Stoyatska Ganna M.
Published: January 2024

The article is primarily aimed at studying and analysing social relations, roles, and dynamics in the field of civil-military cooperation and gender policy. The authors analyze various social stereotypes, political decisions, legislation, and its impact on gender equality and interaction between civil society and the military. In turn, empirical data is used to confirm or refute hypotheses about gender imbalances, challenges and achievements in these areas, but this research is focused on social analysis and understanding of current challenges in the chosen field. The research presupposed the use of various scientific methods, but its base was formed by general and special scientific and philosophical methods. Particular emphasis was placed on the formal-legal approach that facilitated in-depth analysis of international legal statutes, doctrinal perspectives, and rulings from the European Court of Human Rights concerning gender policies embedded within the framework of civil-military cooperation. The authors conduct a theoretical legal examination of civil-military cooperation within the framework of human rights defense, elucidating its distinctive features. Additionally, the paper places considerable emphasis on gender equality in the context of armed conflicts and civil-military cooperation, drawing upon international legal perspectives and scholarly methodologies.
INTERSECCIONALIDADE E VIOLÊNCIA DE GÊNERO DENTRO DO LAR
Authors: Kalb Christiane Heloisa Timm , Silva Raquel Cristini da
Published: January 2024

O presente artigo tem como objetivo analisar a articulação entre a interseccionalidade e criminologia feminista para tratar da violência doméstica no Brasil, com enfoque na mulher negra na sociedade brasileira. A violência doméstica, mais especificamente contra as mulheres negras, pode e deve ser tratada como uma problemática histórica não só de gênero como também de raça, problemática esta que está atrelada a formação de identidade das mulheres negras, desde a construção da sociedade brasileira. Neste sentido, a reflexão trazida envolve as primordiais discussões acerca das categorias raça e gênero, e como o racismo interferiu e ainda interfere nas violências de gênero, e as consequências trazidas pela cultura patriarcal que foi instalada em nossa sociedade. A metodologia aplicada é de revisão bibliográfica, com análise de legislações aplicáveis ao tema. Nessa conjuntura, haja vista que as mulheres negras estão introduzidas no ramo da violência que vai além das questões de gênero, faz-se necessário um olhar central que adentre as especificidades da violência doméstica com o conceito da interseccionalidade. Por ora, concluímos que a violência doméstica no Brasil não pode ser apenas vislumbrada, estudada e analisada sob o aspecto de gênero e classe, mas precisa de um enfoque também sob às lentes das questões raciais.
Drawing out children's false memories
Authors: Strange Deryn , Garry Maryanne , Sutherland Rachel
Published: June 2003

Since the early 1980s there has been much research investigating children's susceptibility to memory distortions when interviewed with a range of techniques. Early studies using the ‘Draw and Tell’ interview have shown that drawing, when used as a recall technique, increases the amount of correct information reported during a recall interview, without decreasing accuracy (Butler et al., 1995). We examined whether drawing, as a rehearsal technique, would lead 5‐ and 6‐year‐old children to claim that implausible events that they had previously said didn't happen, had actually happened. Children were asked whether a list of events on a Life Events Inventory (LEI) had occurred. One week later, half the children completed a ‘Draw and Tell’ interview for some target events but not others. All children completed the LEI again. Children who drew were more likely to claim that all events, not just those they drew, really happened. We discuss implications for the use of the ‘Draw and Tell’ procedure in clinical and therapeutic contexts. Copyright © 2003 John Wiley & Sons, Ltd.
Predicting the directionality of probability words from their membership functions
Authors: Budescu David V. , Karelitz Tzur M. , Wallsten Thomas S.
Published: June 2003

Teigen and Brun have suggested that distinct from their numerical implications, most probability phrases are either positive or negative, in that they encourage one to think of reasons why the target event will or will not occur. We report two experiments testing our hypotheses that (a) the direction of a phrase can be predicted from properties of its membership function, and (b) this relation is invariant across contexts, and (c) —originally formulated by Teigen and Brun (1999)—that strong modifiers intensify phrase directionality. For each phrase, participants encoded membership functions by judging the degree to which it described the numerical probabilities 0.0, 0.1, …, 1.0, and also completed sentences including the target phrase. The types of reasons given in the sentence completion task were used to determine the phrase's directionality. The results support our hypotheses (a) and (b) regarding the relation between directionality and the membership functions, but we found only limited support for hypothesis (c) regarding the effects of modifiers on directionality. A secondary goal, to validate an efficient method of encoding membership functions, was also achieved. Copyright © 2003 John Wiley & Sons, Ltd.
Characterization of denatured proteins by hydrophobic interaction chromatography: A preliminary study
Authors: Bramanti Emilia , Ferri Fabrizio , Sortino Chandra , Onor Massimo , Raspi Giorgio , Venturini Marcella
Published: June 2003

In this preliminary study hydrophobic interaction chromatography (HIC) is proposed as a good tool in order to detect conformational changes induced by chemical denaturants in two globular proteins, cytochrome C (Cyt C) and myoglobin (MYO). Alterations in protein structure were manifested chromatographically by reproducible changes in peak heights, retention time, and appearance of multiple peaks. The HIC behavior of the two model proteins denatured by guanidinium thyocyanate (GdmSCN) was investigated, keeping constant various concentrations of urea in the mobile phase in a TSK‐Gel Phenyl‐5PW column (TosoBiosep). Suitable elution conditions provide evidence of the simultaneous presence of two denatured forms in the case of MYO, and sequential different denatured states of Cyt C. © 2003 Wiley Periodicals, Inc. Biopolymers 69: 293–300, 2003
Quantitation of oxcarbazepine and its metabolites in human plasma by micellar electrokinetic chromatography
Authors: Pucci Vincenzo , Kenndler Ernst , Raggi Maria Augusta
Published: June 2003

A reliable micellar electrokinetic chromatographic method for the determination of oxcarbazepine and its two main metabolites, 10‐hydroxycarbamazepine and 10,11‐trans‐dihydroxy‐10,11‐dihydroxycarbamazepine, in human plasma was developed. The separation and determination of the analytes was achieved using a system consisting of 60 mM SDS in phosphate buffer (30 mM, pH 8.0), to which 20% (v/v) methanol was added. Separation was carried out in an uncoated fused‐silica capillary with a separation voltage of 25 kV and currents typically less than 40 µA. Spectrophotometric detection was at 205 nm. Isolation of oxcarbazepine and its metabolites from plasma was accomplished by a solid‐phase extraction procedure. The mean extraction yield of the analytes from plasma was higher than 94%. The linear correlation coefficients were better than 0.994 for all analytes. The limit of detection was 0.05 µg/mL, the limit of quantitation 0.15 µg/mL. The repeatability for the spiked blank plasma samples was lower than 1.9% and the intermediate precision lower than 2.1%, both expressed as RSD%. The results obtained analysing real plasma samples from epileptic patients under therapy with Tolep® were satisfactory in terms of precision, accuracy and detectability. Copyright­© 2003 John Wiley & Sons, Ltd.
A new efficient method for determining the number of components in PARAFAC models
Authors: Bro Rasmus , Kiers Henk A. L.
Published: June 2003

A new diagnostic called the core consistency diagnostic (CORCONDIA) is suggested for determining the proper number of components for multiway models. It applies especially to the parallel factor analysis (PARAFAC) model, but also to other models that can be considered as restricted Tucker3 models. It is based on scrutinizing the ‘appropriateness’ of the structural model based on the data and the estimated parameters of gradually augmented models. A PARAFAC model (employing dimension‐wise combinations of components for all modes) is called appropriate if adding other combinations of the same components does not improve the fit considerably. It is proposed to choose the largest model that is still sufficiently appropriate. Using examples from a range of different types of data, it is shown that the core consistency diagnostic is an effective tool for determining the appropriate number of components in e.g. PARAFAC models. However, it is also shown, using simulated data, that the theoretical understanding of CORCONDIA is not yet complete. Copyright © 2003 John Wiley & Sons, Ltd.
Monitoring the Location, Amount, and Nature of Carbonaceous Deposits on Aged Zeolite Ferrierite Crystals by Using STEM‐EELS
Authors: van Donk Sander , de Groot Frank M. F. , Stéphan Odile , Bitter Johannes H. , de Jong Krijn P.
Published: June 2003

By the use of electron energy‐loss spectroscopy performed in a scanning transmission electron microscope (STEM‐EELS), detailed spatial information is obtained concerning the amount and nature of carbonaceous deposits formed inside the crystals of the zeolite ferrierite (FER) during the reaction of n‐butene to isobutene. In all cases, gradients in coke concentration over the crystal have been observed and quantified. An extensive accumulation of coke is observed at the entrance of the eight‐membered‐ring (MR) pores, while less coke is present at the entrances of the ten‐MR channels. At a higher coke content, further filling up of the complete micropore system occurs and the eight‐MR pores become fully blocked. The ten‐MR channels remain partially accessible for n‐butene, with alkyl‐aromatic species deposited near the inlets of these channels. With regard to the selective transformation of n‐butene into isobutene, this supports the view that the catalytic action takes place in the pore mouths of the ten‐MR channels. Overall it is demonstrated that the major benefit of STEM‐EELS is the possibility to simultaneously determine the position‐resolved amount and nature of carbonaceous deposits on intact zeolite crystals.
Global versus Local Aromaticity in Porphyrinoid Macrocycles: Experimental and Theoretical Study of “Imidacene”, an Imidazole‐Containing Analogue of Porphycene
Authors: Sargent Andrew L. , Hawkins Ian C. , Allen William E. , Liu Hong , Sessler Jonathan L. , Fowler Christopher J.
Published: June 2003

The synthesis, spectroscopic properties, and computational analysis of an imidazole‐based analogue of porphycene are described. The macrocycle, given the trivial name “imidacene”, was prepared by reductive coupling of a diformyl‐substituted 2,2′‐biimidazole using low‐valent titanium, followed by treatment with 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone. Imidacene displays a porphyrin‐like electronic structure, as judged by its 1H NMR, 13C NMR, and UV/Vis spectral characteristics. Despite a cyclic 18 π‐electron pathway, dichloromethane or ethyl acetate solutions of imidacene were found to undergo rapid decomposition, even in the absence of light and air. A series of high‐level theoretical calculations, performed to probe the origin of this instability, revealed that the presence of a delocalized 18 π‐electron pathway in both imidacene and porphycene provides less aromatic stabilization energy than locally aromatic 6 π‐electron heterocycles in their reduced counterparts. That reduction of imidacene occurs on perimeter nitrogen atoms allows it to maintain its planarity and two stabilizing intramolecular hydrogen bonds, thereby distinguishing it from porphycene and, more generally, from porphyrin. Despite the presence of both 18 π‐ and 22 π‐electron pathways in the planar, reduced form of imidacene, aromaticity is evident only in the 6 π‐electron five‐membered rings. Our computational analysis predicts that routine 1H NMR spectroscopy can be used to distinguish between local and global aromaticity in planar porphyrinoid macrocycles; the difference in the chemical shift for the internal NH protons is expected to be on the order of 19 ppm for these two electronically disparate sets of ostensibly similar compounds.
Synthesis, Structure, and Fluxionality of Strained Hypercoordinate Silicon‐Bridged [1]Ferrocenophanes
Authors: Bourke Sara C. , Jäkle Frieder , Vejzovic Emira , Lam Kin‐Chung , Rheingold Arnold L. , Lough Alan J. , Manners Ian
Published: June 2003

The first hypercoordinate sila[1]ferrocenophanes [fcSiMe(2‐C6H4CH2NMe2)] (5 a) and [fcSi(CH2Cl)(2‐C6H4CH2NMe2)] (5 b) (fc=(η5‐C5H4)Fe(η5‐C5H4)) were synthesized by low‐temperature (−78 °C) reactions of Li[2‐C6H4CH2NMe2] with the appropriate chlorinated sila[1]ferrocenophanes ([fcSiMeCl] (1 a) and [fcSi(CH2Cl)Cl] (1 d), respectively). Single‐crystal Xray diffraction studies revealed pseudo‐trigonal bipyramidal structures for both 5 a and 5 b, with one of the shortest reported Si⋅⋅⋅N distances for an sp3‐hybridized nitrogen atom interacting with a tetraorganosilane detected for 5 a (2.776(2) Å). Elongated SiCipso bonds trans to the donating NMe2 arms (1.919(2) and 1.909(2) Å for 5 a and 5 b, respectively) were observed relative to both the non‐trans bonds (5 a: 1.891(2); 5 b: 1.879(2) Å) and the SiCipso bonds of the non‐hypercoordinate analogues ([fcSiMePh] (1 b): 1.879(4), 1.880(4) Å; [fcSi(CH2Cl)Ph] (1 e): 1.881(2), 1.884(2)). Solution‐state fluxionality of 5 a and 5 b, suggestive of reversible coordination of the NMe2 group to silicon, was demonstrated by means of variable‐temperature NMR studies. The ΔG≠ of the fluxional processes for 5 a and 5 b in CD2Cl2 were estimated to be 35.0 and 37.6 kJ mol−1, respectively (35.8 and 38.3 kJ mol−1 in [D8]toluene). The quaternization of 5 a and 5 b by MeOTf, to give [fcSiMe(2‐C6H4CH2NMe3)][OTf] (7 a‐OTf) and [fcSi(CH2Cl)(2‐C6H4CH2NMe3)][OTf] (7 b‐OTf), respectively, supported the reversibility of NMe2 coordination at the silicon center as the source of fluxionality for 5 a and 5 b. Surprisingly, low room‐temperature stability was detected for 5 b due to its tendency to intramolecularly cyclize and form the spirocyclic [fcSi(cyclo‐CH2NMe2CH2C6H4)]Cl (9‐Cl). This process was observed in both solution and the solid state, and isolation and Xray characterization of 9‐Cl was achieved. The model compound, [Fc2Si(2‐C6H4CH2NMe2)2] (8), synthesized through reaction of [Fc2SiCl2] with two equivalents of Li[2‐C6H4CH2NMe2] at −78 °C, showed a lack of hypercoordination in both the solid state and in solution (down to −80 °C). This suggests that either the reduced steric hindrance around Si or the unique electronics of the strained sila[1]ferrocenophanes is necessary for hypercoordination to occur.
Chemical Reactivity Controlled by Negative Hyperconjugation: A Theoretical Study
Authors: Nilsson Lill Sten O. , Rauhut Guntram , Anders Ernst
Published: June 2003

Negative hyperconjugation is a general phenomenon that can be observed in many areas of chemistry. The knowledge of its impact on structural parameters and conformational issues is well established, but little is known about its importance for chemical reactivity. Here we present a systematic study of different aspects of negative hyperconjugation on the reactivity of complex heterocyclic systems using density functional theory. Intermediates from the reaction of nitrogen‐based nucleophiles with bis(1,3,4‐thiadiazolo)‐1,3,5‐triazinium halides serve as benchmark systems to demonstrate the effects of negative hyperconjugation on bond lengths, on the relative stability of conformational isomers and transition structures and, most importantly, on the different reaction pathways of these species. The computational results provided here are in part supported by experiments reported elsewhere.
Syntheses and Coordination Chemistry of Aminomethylphosphine Derivatives of Adenine
Authors: Zhang Qingzhi , Hua Guoxiong , Bhattacharyya Pravat , Slawin Alexandra M. Z. , Woollins J. Derek
Published: June 2003

Two aminomethylphosphane derivatives of adenine 9‐(2‐{bis[(diphenylphosphanyl)methyl]amino}ethyl)adenine (La) and 9‐(3‐{bis[(diphenylphosphanyl)methyl]amino}propyl)adenine (Lb) were synthesised. Oxidation of La and Lb with H2O2, elemental sulfur or elemental selenium led to the corresponding oxidized products 4a/b−6a/b. Both La and Lb behave as didentate ligands towards late transition metals. Reaction of La or Lb with [MX2(cod)] (M = Pd, Pt; X = Cl, Me) gave chelate complexes 7a/b−10a/b. Reaction of La or Lb with [AuCl(tht)] or [{RuCl(μ‐Cl)(p‐MeC6H4iPr)}2] gave the didentate bridging complexes 11a/b and 12a. All compounds have been fully characterised by microanalysis, IR, 1H and 31P{1H} NMR spectroscopy, and EI/CI/FAB mass spectrometry. 1H{31P} NMR and 1H‐13C correlation experiments were used to confirm the spectral assignments where necessary. Two compounds were structurally characterised by X‐ray crystallographic analysis. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Determination of Se(IV) in On‐Line System by Cathodic Stripping Voltammetry
Authors: Korolczuk Mieczyslaw , Grabarczyk Malgorzata
Published: June 2003

A sensitive and selective on‐line voltammetric procedure for determination of traces of Se(IV) is presented. The pulsed potential accumulation was proposed for minimization of interferences of surface active substances and foreign ions. The calibration plot was linear from 1×10−9 mol L−1 to 4×10−8 mol L−1 for accumulation time of 180 s. The relative standard deviation was 6.1% (n=5) for a Se(IV) concentration of 1×10−8 mol L−1. The detection limit estimated from (3 σ) for an accumulation time of 180 s was about 4×10−10 mol L−1. The validation of the procedure proposed was made by a recovery tests for tap and river water samples.
The removal of reactive azo dyes by natural and modified zeolites
Authors: Armaǧan B , Özdemir O , Turan M , Çelik MS
Published: June 2003

The adsorption mechanism of three reactive dyes by zeolite has been examined with the aim of identifying the ability of zeolite to remove textile dyes from aqueous solutions. Towards this aim, a series of batch adsorption experiments was carried out, along with determination of the electrokinetic properties of both natural and modified zeolites. The adsorbent in this study is a clinoptilolite from the Gördes region of Turkey. The reactive dyes CI Reactive Black 5, Red 239 and Yellow 176 are typical azo dyes extensively used in textile dyeing. Adsorption tests were carried out as a function of mixing time, solids concentration, dye concentration and pH. The adsorption results indicate that the natural zeolite has a limited adsorption capacity for reactive dyes but is substantially improved upon modifying its surfaces with quaternary amines. An electrostatic adsorption mechanism involving the formation of a bilayer of amine molecules on the clinoptilolite surface onto which anionic dye molecules adsorb, depending on their polarities, is proposed. The results are also supported by electrokinetic measurements. The adsorption data were fitted to the Langmuir isotherm and it was found that the modified sepiolite yields adsorption capacities (qe) of 111, 89 and 61 mg g−1 for Red, Yellow and Black, respectively. These results are comparable to a popular adsorbent, activated carbon. Copyright © 2003 Society of Chemical Industry
Field investigations of soil hydrological properties of fen soils in North‐East Germany
Authors: Schindler Uwe , Müller Lothar , Behrendt Axel
Published: June 2003

To investigate the changes of hydrological properties of peat soil in course of soil development, field measurements at 84 fen sites (Histosols) in 19 fen regions of North‐East Germany were carried out. Capillary water supply at all the stages of soil development was not limited up to 70 cm of ground water level. Worsening of plant water supply was the result of mud accumulation in the capillary fringe, ground water levels located deeper than 70 cm below soil surface, low hydraulic conductivity in the ground water zone, and hysteresis effects, affected by high dynamics of ground water level during the day.
Longitudinally implanted intrafascicular electrodes for stimulating and recording fascicular physioelectrical signals in the sciatic nerve of rabbits
Authors: Zheng Xiujun , Zhang Jian , Chen Tongyi , Chen Zhongwei
Published: June 2003

The purpose of this experiment was to determine the stimulating and recording characters of fascicular physioelectrical signals in the activity of peripheral nerves by longitudinally implanted intrafascicular electrodes (LIFEs) in a rabbit sciatic nerve model, and discuss the future application of LIFEs in functional electrical stimulation (FES) and control of electric arm prosthesis. In methodology, LIFEs were inserted into the fasciculus of the sciatic nerves of rabbits and used as recording electrodes and stimulating electrodes, respectively. Motor‐evoked potentials (MEPs), cortical somatosensory‐evoked potentials (CSEPs), and electromyography (EMG) were recorded by using a transcranial stimulation system (TCS). LIFEs were found to have stable stimulating and recording characters. The interpeak amplitudes (IPAs) of MEPs ranged from 78–156 μV (mean ± SD, 102 ± 23.2 μV). The onset latency (OL) of MEPs ranged from 9.8–11.2 msec (mean ± SD, 10.8 ± 0.6 msec). The interpeak amplitudes (IPAs) of CSEPs ranged from 5.8–7.2 μV (mean ± SD, 6.7 ± 0.5 μV). The onset latency (OL) of CSEPs ranged from 11.4–14.6 msec (mean ± SD, 12.8 ± 1.3 msec). EMGs could be recorded in the gastrocnemius, but could not be recorded in the tibialis anterior muscle. In conclusion, longitudinally implanted intrafascicular electrodes can act as intrafascicular stimulating and recording electrodes with high selective characters. They can provide a new way to study fascicular physioelectrical signals and their function in the activity of peripheral nerves. © 2003 Wiley‐Liss, Inc. MICROSURGERY 23:268–273 2003
Experimental model of heterotopic uterus transplantation in the laboratory rat
Authors: Jiga Lucian P. , Lupu Cătălin M. , Zoica Bogdana S. , Ionac Mihai
Published: June 2003

The present study describes a standardized experimental model of whole‐uterus‐and‐ovaries heterotopic allotransplantation in the laboratory rat. Fifteen transplantation procedures were done. The anatomy of the pelvic region was studied with an additional 20 dissections, noting the topographical and vascular anatomy of the uterus, fallopian tubes, and ovarian vessels. Recipients were randomized into three groups. The average operative time was 150 min. The postoperative survival rate was 100%. Postoperative vascular anastomosis patency was 100%, and 26% at 72 hr. Recipients were euthanized at 24 hr (group I), 48 hr (group II), and 72 hr (group III); grafts were harvested and examined macroscopically, and fixed in formaline for histopathological and immunocytochemical analysis. Failure in 74% of the grafts at 72 hr was due to early thrombosis, starting from the capillary bed and progressing towards the main feeding pedicles. More studies must be undertaken to further understand the rejection mechanisms in transplanted reproductive organs. The efficiency, feasibility, and safety for such an operation in humans remain to be proven. We consider the present model a suitable tool to study all the above‐mentioned goals. © 2003 Wiley‐Liss, Inc. MICROSURGERY 23:246–250 2003
Preparation and characterization of organoclay nanocomposites based on natural rubber
Authors: López‐Manchado MA , Herrero B , Arroyo M
Published: June 2003

Rubber compounds based on natural rubber (NR) reinforced with octadecylamine‐modified bentonite have been prepared via a vulcanization process and characterized by several techniques. The silicate nanolayers are exfoliated and uniformly dispersed in the polymer chains. Monsanto measurements have shown that the organoclay accelerates the vulcanization reaction and, furthermore, gives rise to a marked increase of the torque, indicating that the elastomer becomes more crosslinked in the presence of the organoclay. These results were corrobated by swelling measurements since a noticeable increase in the curing degree was observed when the organoclay was added to the rubber recipe. Moreover, thermodynamic parameters have shown an increase in the structural order of the nanocomposite. In addition, thermal analysis supports the assumption that the degree of curing of the elastomer increases when the organoclay is added to the elastomer. An appreciable increase of the involved heat during the curing reaction has been observed. Moreover, the Tg of the NR increases in the presence of the organoclay due to the confinement of the elastomer segment into the organoclay nanolayers, which restricts the mobility of the chains. Copyright © 2003 Society of Chemical Industry
Soft immobilized pH gradient gels in proteome analysis: A follow‐up
Authors: Bruschi Maurizio , Musante Luca , Candiano Giovanni , Ghiggeri Gian Marco , Herbert Ben , Antonucci Francesca , Righetti Pier Giorgio
Published: June 2003

As a follow‐up of a previous work on two‐dimensional map analysis utilizing soft (< 4%T) immobilized pH gradient (IPG) matrices in the first dimension (Candiano et al., Electrophoresis 2002, 23, 292–297), we have further optimized the preparation of such dilute IPG gels. One important step for obtaining an even reswelling of the entire IPG strip along the pH 3–10 interval is a washing step in 100 mM citric acid. It appears as though after rinsing off the excess acid in distilled water, a gradient of this tricarboxylic acid remains trapped into the IPG matrix, from almost nil at the acidic gel region to substantially higher amounts in its basic counterpart. This gradient helps in obtaining a uniform reswelling of the IPG strip, since carboxyl groups are more heavily hydrated than amino groups. The combined effects of uniform reswelling and of diluting the gel matrix favor penetration of large macromolecules (> 200 kDa) and allow for better spot resolution and for the display of a substantially higher number of spots also in the 30–60 000 Da region. A delipidation step in tri‐n‐butylphosphate:acetone:methanol (1:12:1) appears to substantially improve spot focusing and greatly diminish streaking and smearing of spots in all regions of the pH gradient.
Identification of new celiac disease autoantigens using proteomic analysis
Authors: Stulík Jiří , Hernychová Lenka , Porkertová Stanislava , Pozler Oldřich , Tučková Ludmila , Sánchez Daniel , Bureš Jan
Published: June 2003

Celiac disease is an autoimmune disorder in which gluten peptides presented by specific HLA‐DQ2‐ and HLA‐DQ8‐positive antigen presenting cells elicit immune response in connective tissue of lamina propria. Immunoglobulin A (IgA) antiendomysial antibodies are specific for celiac disease and are used for screening, diagnosis and follow‐up of this disease with an almost 100% sensitivity and specificity. The major target antigen of IgA antiendomysial antibodies was identified as tissue transglutaminase; nevertheless, the existence of the additional unique celiac disease‐specific autoantigens is anticipated. In this study we have utilized a proteomic approach in order to search out new autoantigens recognized by serum antibodies of patients with active celiac disease. We report the detection of 11 proteins that were immunorecognized with various frequencies by sera of patients with celiac disease. Four autoantigens were identified by mass fingerprinting approach as actin, ATP synthase β chain and two charge variants of enolase α. While production of IgA antibodies against actin molecules were described earlier, the existence of autoantibodies to ATP synthase β chain and enolase α species in sera collected from patients with active celiac disease are described for the first time. These results are suggestive of the existence of additional celiac disease autoantigens with possible diagnostic utility.
An approach to the proteomic analysis of a breast cancer cell line (SKBR‐3)
Authors: Wu Shiaw‐Lin , Hancock William S. , Goodrich Geoffrey G. , Kunitake Steven T.
Published: June 2003

This report describes the profiling of proteins in a sample prepared by laser capture microdissection (LCM) from a breast cancer cell line (SKBR‐3). This experimental approach serves as a model system for proteomic studies on selected tissue samples and for studies of specific cell types. The captured cells were isolated in a dehydrated and reduced state and solubilized with a denaturing buffer. After dilution the protein mixture was digested with trypsin and the resulting peptide mixture was fractionated by reversed phase HPLC (RPLC) and analyzed on an ion trap mass spectrometer. A key part of this study is the combination of the LCM process with an extraction/digestion procedure that allowed effective solubilization of a significant part of the cellular sample in a single step. The identity of the peptides was determined by tandem mass spectrometry measurements in which the resulting spectra were compared with genomic and proteomic databases and protein identifications were made. While only peptides with a high probability assignment were used, the interpretation of mass spectral fragmentation patterns were also confirmed by manual interpretation of the spectra. Also, for the more abundant proteins the initial protein assignment from the best match peptide was strengthened by the observation of additional confirmatory peptide identifications. Another selection criteria was correlation of the mass spectrometric studies with clinical and genomic studies of potential cancer markers in tumor samples. This proteomic study allowed identification of the following proteins: human receptor protein kinase HER‐2 or ERBB‐2 and related kinases HER‐3 and HER‐4, the gene products from breast cancer type I and II susceptibility genes and cytoskeletal components such as cytokeratins 8, 18 and 19. Other proteins include fibroblast growth factor receptor variants (FGFR‐2&4) and T‐lymphoma invasion and metastasis inducing protein 1 (TIAM1). In addition several nonreceptor protein kinases YES, FAK and JAK‐1 and 3 were identified. Since the study was performed on a limited number of cells (approximately 10 000) it raises the possibility of such studies being performed on individual patient samples prepared by needle biopsy.