bluuebunny/crossref_metadata_2025 huggingface dataset:
Rolling bearing fault diagnosis based on Gramian angular difference field and improved channel attention model
Authors: Wei Lunpan , Peng Xiuyan , Cao Yunpeng
Published: January 2024

Fault diagnosis of rolling bearings is a critical task, and in previous research, convolutional neural networks (CNN) have been used to process vibration signals and perform fault diagnosis. However, traditional CNN models have certain limitations in terms of accuracy. To improve accuracy, we propose a method that combines the Gramian angular difference field (GADF) with residual networks (ResNet) and embeds frequency channel attention module (Fca) in the ResNet to diagnose rolling bearing fault. Firstly, we used GADF to convert the signals into RGB three-channel fault images during data preprocessing. Secondly, to further enhance the performance of the model, on the foundation of the ResNet we embedded the frequency channel attention module with discrete cosine transform (DCT) to form Fca, to effectively explores the channel information of fault images and identifies the corresponding fault characteristics. Finally, the experiment validated that the accuracy of the new model reaches 99.3% and the accuracy reaches 98.6% even under an unbalanced data set, which significantly improves the accuracy of fault diagnosis and the generalization of the model.
Scenarios and opportunities in the sugar and ethanol industry - challenges and opportunities towards a low carbon economy in Brazil
Authors: Teixeira Layla Leao Lima , Murari Thiago Barros , Brito Filipe Cardoso , Marques Samuel Carvalho de Azevedo , Cardoso Hugo Saba Pereira , Nascimento Filho Aloisio Santos
Published: January 2024

With the future of transport embracing new models of mobility, hybridization and electrification, a reduction in fossil fuel consumption is expected. Biofuels, especially biomass-derived ethanol, play a significant role in this transition by boosting greenhouse gas emissions. Ethanol production is considered strategic by industrialized countries, coming from renewable biomass in the energy sector. Studies have explored the contribution of biofuels to the decarbonization of the vehicle transport sector at levels from 2030 to 2050. However, the future energy matrix remains uncertain, with the potential coexistence of multiple matrices and technologies. This research evaluates Brazil's position in these scenarios, considering the challenges and risks to achieve a sustainable energy matrix in the transport sector. The methodology involves the analysis of decarbonization scenarios, methods and concepts, examining scenarios projected for the future of the light vehicle sector in the main consumer countries. In addition, the research discusses Brazil's role in biofuels and transport scenarios, with a focus on Brazilian ethanol in the global bioeconomy by 2050. The challenge of decarbonization in the transport sector is global and highlights the importance of Brazil as the second largest producer of bioethanol, after the US.
Benefícios econômicos do manejo biológico de Heterodera glycines na cultura da soja
Authors: Loureiro Elisângela de Souza , Dias Neto José Augusto , Pessoa Luis Gustavo Amorim , De Gregori Gabriela Silva , Da Silva Wilker Kelvin Amaral , Nichele Murilo , De Oliveira Inessa Steffany Torres , De Oliveira Isaías
Published: January 2024

Os fungos Trichoderma harzianum e Purpureocillium lilacinum encontrados na rizosfera e no solo são antagonistas de doenças radiculares e nematoides fitopatogênicos. O objetivo do trabalho foi avaliar a eficiência de T. harzianum e P. lilacinum no manejo de Heterodera glycines na cultura da soja. O delineamento experimental foi em blocos casualizados com quatro repetições, constituído de seis tratamentos sendo estes compostos pela testemunha (1), tratamento Cruiser 350® + Maxim XL® + Avicta Completo® (2), tratamento com o fungo P. lilacinum (3), tratamento com Avicta Completo® associado ao P. lilacinum (4), tratamento com a associação dos fungos P. lilacinum e T. harzianum (5) e tratamento P. lilacinum + T. harzianum + Avicta Completo® (6). As parcelas foram compostas por 7 linhas com espaçamento entre linhas de 0,45 m, com tamanho de 3,60 m x 10 m. Os dados da quantidade de nematoides no solo e nas raízes, o cálculo da produtividade da soja por tratamento foram submetidos à análise de variância pelo teste de Skott-knot a 5% de probabilidade. Na safra 2011/2012 a associação de produtos biológicos e químicos proporcionaram redução de 100% na quantidade de H. glycines no solo e nas raízes os produtos biológicos reduziram 69,2% da população de nematoides. Entretanto, na safra 2011/2012 a associação dos fungos P. lilacinus+T. harzianum proporcionaram maior redução no número de nematoides no solo e nas raízes. Os produtos biológicos promoveram maior produtividade e maior lucro quando comparado ao produtos químicos isolados e associados aos produtos biológicos.
Educação popular, teoria da argumentação jurídica e desenvolvimento como liberdade: convergências e desafios na transformação democrática
Authors: Andrade Alex Pires
Published: January 2024

Este artigo tem como objetivo analisar o papel da educação na transformação democrática, explorando os desafios e oportunidades que surgem em um mundo em constante evolução, caracterizado pela revolução digital, mudanças climáticas globais e transformações políticas. Para atingir esse propósito, examinaremos as teorias de argumentação jurídica de Robert Alexy e a abordagem do desenvolvimento como liberdade de Amartya Sen. Além disso, consideraremos os argumentos apresentados por Carlos Ayres Britto, Daron Acemoglu, James A. Robinson e outros autores relevantes nos campos do Direito e da Ciência Política. Este trabalho se baseia em uma extensa pesquisa bibliográfica para compreender os princípios e fundamentos da Educação Popular e da Gestão Democrática, com foco na identificação de sua convergência em torno de um projeto político de sociedade.
The Effect of Natural Disasters on the Environmental Resilience of Rural Areas
Authors: Faradiba Faradiba
Published: January 2024

Disasters have detrimental effects on environmental aspects. This research aims to investigate the negative impacts of earthquakes, volcanic eruptions and land drought on the environment. This research aims to determine the impact of natural disasters on environmental factors. The data used in this research was obtained from Podes 2021 and the Environmental Resilience Index (IKL) 2022 and 2023. The method applied in this research is multiple linear regression. The results of this research show that natural disasters have a negative impact on environmental conditions. Of the three independent variables for natural disasters in this study, it is known that volcanic eruptions have the most significant negative effects, both one year and two years after the event occurs. The negative impacts of natural disasters are still felt by the community at least 2 years after the disaster occurs. Therefore, an extra role is needed from the government to carry out evacuations when a disaster occurs, as well as implementing mitigation measures early on to reduce negative impacts.
Meta-analysis of the Aspects of Student Thinking Creativity in Learning Project Based Learning (PjBL) to Improve Learning Outcomes
Authors: Syarifuddin Andi , Gani Hamsu Abdul , Mappeasse Muhammad Yusuf
Published: January 2024

The objective of this study was to examine elements of student cognitive ingenuity developed through Project-based Learning (PjBL) to enhance educational achievements. The research participants consisted of 22 students enrolled in the Electrical Engineering Study Program. The basic hypothesis posits that the presence of creative thinking elements has a beneficial impact on enhancing students' learning results. The key aspects encompassed are fluidity, flexibility, originality, and elaboration. The data were gathered using questionnaire-based observation, utilizing instruments that have been validated by specialists. This research falls under the category of Research and Development (R&D) and follows the Thiagarajan 4D paradigm, which involves defining, designing, developing, and disseminating. The data analysis was conducted using descriptive statistics and the PjBL learning effectiveness test, with a comparison made between intact groups. Analysis reveals that all four aspects examined have a significant impact on enhancing learning outcomes. Nevertheless, the most significant impact is observed in the domain of fluency when it comes to learning outcomes. The efficacy of PjBL learning in enhancing learning outcomes in Energy Conversion courses was found to be significantly superior to that of conventional learning approaches. In the upcoming study, it is advised to investigate and expand upon four unexplored facets of creative thinking.
Effectiveness of Use of Interactive Wordwall Media in Class VII Procedure Text Materials at MTS Al-Hidayah Sungkai
Authors: Nadhirah Maskurotun , Hadiyanto  , Harjono Hary Soedarto
Published: January 2024

Appropriate, effective, and efficient media is one way to improve the learning quality. Proper, effective, and efficient media can optimally influence student learning processes and outcomes. This research aims to see the effectiveness of using word wall learning media in class VII procedure text material at MTs Al-Hidayah. The method used was quasi-experimental, with a sample of Class VII 1 students as the control class and Class VII 2 as the experimental class, and applying a pretest-posttest design. The difference test was conducted to calculate variations in the effectiveness of word wall learning media compared to without the help of learning media. The results of this research show that there are differences in learning outcomes between students who use learning media and those who do not use learning media. The effectiveness of using learning media on learning outcomes student can be seen from the average percentage of N-Gain for the experimental and control classes. The average N-Gain percentage of the practical class was 58.32% in the quite effective category, and the control class obtained an average N-Gain percentage of 18.32% in the ineffective category. This research has implications for developing appropriate, effective, and efficient media in learning Indonesian to improve student learning outcomes.
Phytochemical Screening, In vitro Antioxidant, Antibacterial Activities on Skimmia laureola Leaves Extract: A Research
Authors: Sharma Panshul , Raj Hans , Choudhary Diksha , Kumari Pooja , Kaur Rajdeep , Ankita  , Kumar Surendar
Published: January 2024

Background: Skimmia laureola owned by the Rutaceae family is one of the plants that might use the Indian traditional treatment system in the Indian subcontinent and act against many diseases. So, this new research was carried out to scientifically confirm the various solvent fractions and separate the active fraction from the plant against antioxidants and bacterial and microbial growth.

Objectives: The main objective of the study involves the Phytochemical screening and research of invitro activities i.e. antioxidant and antibacterial from the extracts of the leaves part of the Skimmia laureola plant.

Methods: Phytochemical screening was carried out of various extracts by the tests that involved it. Invitro antibacterial and antioxidant activities were examined of the plant extract through various methods DPPH, Metal chelating activity, Reducing power ability, Hydrogen peroxide scavenging activity, and Nitric oxide scavenging activity. After completion of the research, all the activity is shown graphically.

Results: Invitro antioxidant activity shows that methanolic extract shows more antioxidant activity than other extracts. The antibacterial investigations show that the ethanolic extract of the plant removal was very compelling for bacterias Streptococcus aureus, Bacillus subtilis, and Escherichia coli at 25 μg/ml, 50 μg/ml, 75 μg/ml, 100 μg/ml, 200 μg/ml and 300 μg/ml individually.

Conclusion: Auxiliary metabolites (phenol, flavonoid, tannin, and content) have been quantified. In antioxidant tests such as DPPH activity, the methanolic extract of the plant outperforms other extracts such as chloroform, petroleum ether, ethanol, and aqueous extract. The antibacterial investigations show that the ethanolic extract of the plant removed was very compelling for bacterias Streptococcus aureus, Bacillus subtilis, and E.coli. The current study may be useful in improving data regarding its distinguishing proof boundaries expected primarily in the method of the adequacy of homegrown medications in the current situation lacking administrative laws to control the nature of natural medications, as well as discovering antioxidants and antibacterial action.
Evaluation of Physicochemical, Functional and Morphological Characteristics of Starch Extracted from Defatted Conophor Seed (Tetracarpidium conophorum)
Authors: Odekunle Olubukola Yinka , Oluwalana Isaac Babatunde, , Ijarotimi Oluwole Stephen , Agboola Sesan Amos
Published: January 2024

Aim: Starch is the main carbohydrate store for numerous crops and each crop has distinct and unique characteristics. This study was aimed at investigating the physicochemical composition, functional properties and morphological characteristics of starch extracted from defatted Conophor seed flour.

Place and Duration: Food Chemistry Laboratory, Department of Food Science and Technology, and Biochemistry Laboratory of the Federal University of Technology, Akure, from March 2023 to September 2023.

Methodology: Conophor seeds were washed, shelled manually, oven dried, milled into coarse flour and then defatted using solvent extraction method with the use of a soxhlet extractor. The defatted flour was air dried and grounded into fine powder. Starch was extracted by sedimentation at pH 11.0 and then oven dried and grounded into powder. The physicochemical composition, functional properties and morphological characteristics of Conophor starch were studied.

Results: The physicochemical study shows that Conophor starch was abundant in carbohydrate (77.26%) but had a low protein (4.46%), fat (1.99%) and fibre (1.20%) content. Mineral content of the starch were high with calcium (194.17mg/g), copper (0.05mg/g), manganese (0.42mg/g), magnesium (4.26mg/g), iron (0.34mg/g), zinc (1.59mg/g), phosphorus (26.1mg/g), sodium (23.20mg/g) and potassium (37.13mg/g). The functional property of Conophor starch showed a high water absorption capacity (513.33%), oil absorption capacity (347.57%), emulsion capacity (45.48%), emulsion stability (50.00%), swelling index (246.67%), gelation capacity (12.00m/v) and low foaming capacity (12.69%) and foaming stability (3.26%). Conophor starch had a low pasting property with peak viscosity (14.00 RVU), final viscosity (16.00 RVU) and set-back viscosity (4.00 RVU).

Conclusion: The study showed Conophor starch to be a rich source of mineral which makes it suitable for use as a supplement and its functional property makes it capable to be used in some industrial processes. However, the low paste quality of the starch renders it unsuitable for use in food processes that requires high paste formation but may be considered suitable for use in non- food related industries.
Drought Stress and its Tolerance Mechanism in Wheat
Authors: Gupta Ajeet Kumar , Agrawal Mohit , Yadav Harikant , Mishra Govind , Gupta Rishabh , Singh Abhay , Katiyar Dheeraj , Singh Piyusha , Srivastava Aman
Published: January 2024

Plants encounter diverse forms of stress in response to fluctuations in their surrounding environment. Drought is a very detrimental environmental stressor that negatively impacts crop Plants. The phenomenon of drought stress in Plants is characterized by its intricate nature, arising from many environmental factors, including limited soil water availability, elevated soil salinity levels, and increased ambient temperature. The latter is referred to as physiological drought. The wheat plant exhibits high sensitivity to dry conditions, particularly during the flowering and grain-filling stages. The phenomenon led to a significant decline in the growth and production of wheat crops. Water stress during crucial growth stages, including tillering, grain filling, and flowering, has been identified as a significant factor leading to substantial reductions in crop output. Drought stress in wheat induces morphological, physiological, biochemical, and molecular alterations. Plants employ three fundamental survival strategies, stress avoidance, escape, and tolerance, in response to drought-induced stress. The cultivation of drought-tolerant cultivars and the implementation of agronomic practices play a crucial role in the development of novel water-use strategies for effective drought management. Drought tolerance is a multifaceted characteristic governed by multiple genes, with their expressions modulated by diverse environmental factors. Therefore, the challenge of breeding for this particular trait is considerable, necessitating the utilization of novel molecular techniques such as molecular markers, quantitative trait loci [QTL] mapping procedures, and gene expression patterns to generate genotypes that exhibit tolerance to drought conditions. Wheat possesses multiple genes that contribute to drought stress tolerance by encoding various enzymes and proteins, such as late embryogenesis abundant [LEA], abscisic acid-responsive [RAB], rubisco, helicase, proline, glutathione-S-transferase [GST], and carbohydrates, which are involved in mitigating the effects of drought stress. This review paper has focused on examining the impact of water limitation on several aspects of wheat, including its morphology, physiology, biochemistry, and molecular responses. Additionally, it explores the potential losses incurred by wheat due to drought-induced stress.
Generation of Test Cases for Identification of Crime against Women through HLR and VLR
Authors: Kumar Hemant , Shukla Rishi , Gautam Prem Kumar , Tiwari Manjusha , Saxena Vipin
Published: January 2024

In recent years, it is observed that crimes against women are increasing exponentially growth manner and the nature of the crime may be sexual harassment at any place including the workplace, acid attack at any place, rape, domestic violence, and many more which the criminal may leave his location treated as visitor location for performing criminal activities against the women whose mobile is treated as a home location. In the present work, a criminal scene is established through the mathematical technique for matching these two locations for identification of the crime. From the literature, it is observed that mathematical matching techniques are not in use for the identification of crime. The purpose of the present work is to fill this gap by developing a Unified Model by the use of Unified Modeling Language which has been validated through valid test cases after implementing the model in the Python programming language.
Use of Chemotaxonomy To Study the Influence of Benzalkonium Chloride on Bacterial Populations in Biodegradation Testing
Authors: Kümmerer Klaus , Al‐Ahmad Ali , Henninger Almut
Published: January 2003

Contradictory results are reported for the behaviour of quaternary ammonium compounds (QACs) in sewage treatment plants (STPs). QACs may sorb onto activated sludge. Only little information is available with respect to effects of QACs against bacteria in STPs. Only 5 to 15 % of bacteria present in sewage sludge can be detected by means of culture dependent microbiological methods. The shift of the bacterial populations due to effects of test compounds have not been studied up to now with culture independent methods. The microbial populations shift was studied in situ using culture independent chemotaxonomy profiling ubiquinones and polyamines. Additionally, toxic effects of QACs against bacteria present in the test vessels of the Zahn‐Wellens test (OECD 302 B) were assessed with a toxicity control in the test. The ubiquinone profiles representing changes in Gram‐negative populations mainly showed that the activated sludge was affected only in test vessels containing benzalkonium chloride. According to chemotaxonomy Acinetobacter or/and some members of Pseudomonas spp. have been selected by benzalkonium chloride after some adaptation period (8 to 12 days).
Effects of Short‐term and Long‐term Aluminium Stress on Photosynthesis, Respiration, and Reproductive Capacity in a Unicellular Green Flagellate (Euglena gracilis)
Authors: Danilov Roman A. , Ekelund Nils G. A.
Published: January 2003

Effects of short‐term (1 h exposure) and long‐term (7 d exposure) aluminium stress on photosynthesis and reproductive capacity have been studied in Euglena gracilis strain Z. Following concentrations of Altot (added as AlCl3) were tested: 0.5 mg L‐1, 1.0 mg L‐1, 1.5 mg L‐1, 2.5 mg L‐1, 5.0 mg L‐1, 7.5 mg L‐1, 10.0 mg L‐1, and 15.0 mg L‐1 Al, respectively. Growth rates at different aluminium concentrations did not show significant differences, except at 15.0 mg L‐1Al. Initial respiration was higher in long‐term than in the short‐term experiments. It is supposed that an energy‐dependent mechanism of excretion of aluminium ions has been active in the stressed cells. Consequently, the cells of E. gracilis after long‐term exposure to aluminium are believed to be more acclimatised to the aluminium stress. Photosynthetic efficiency (PE) has been negatively affected by aluminium in all experiments performed. Differences between control algae and those treated with aluminium were significant in all cases. PE in long‐term experiments was in general significantly higher at all concentrations of aluminium studied, compared to the short‐term experiments. The aluminium concentrations tested led only to a general decrease in PE while the level of decrease was not especially concentration‐dependent. In general, aluminium tolerance of E. gracilis can be estimated as low, especially by short‐term exposure. However, good acclimatisation capacity of this green flagellate to aluminium doses by long‐term exposure can be supposed.
Scum in Nutrient Removal Plants: The Role of Carbon Sources in “Microthrix parvicella” Growth
Authors: Lemmer Hilde , Müller Elisabeth , Schade Margit
Published: January 2003

Scum formation is a widespread problem in activated sludge nutrient removal plants. It often comes along with an excessive development of the filamentous bacterium “Microthrix parvicella” stabilizing the flotation process. As “M. parvicella” was found to depend on long‐chain fatty acids (LCFA) as sole carbon source not only in vitro but also in situ, some options of in‐situ substrate supply are discussed. Wastewater concentrations of fatty acids in the range of 2 to 15 mg L‐1 and homologue concentrations from synthetic surfactant degradation below 10 mg L‐1 rule out these substrates as source for excessive biomass production. They might, however, well be suitable for start‐up of a “M. parvicella” population. Build‐up of excessive biomass might rely on fatty acid supply originating in cell walls of lysed stationary phase bacteria of long residence time sludge fractions such as scum layers. Moreover, biogenic surfactants such as rhamnolipids have been proved to be an excellent carbon source for excessive biomass production in vitro.
The Delocalization Index as an Electronic Aromaticity Criterion: Application to a Series of Planar Polycyclic Aromatic Hydrocarbons
Authors: Poater Jordi , Fradera Xavier , Duran Miquel , Solà Miquel
Published: January 2003

This work introduces a new local aromaticity measure, defined as the mean of Bader's electron delocalization index (DI) ofpara‐related carbon atoms in six‐membered rings. This new electronic criterion of aromaticity is based on the fact that aromaticity is related to the cyclic delocalized distribution of π‐electrons. We have found that this DI and the harmonic oscillator model of aromaticity (HOMA) index are strongly correlated for a series of six‐membered rings in eleven planar polycyclic aromatic hydrocarbons. The correlation between the DI and the nucleus‐independent chemical shift (NICS) values is less remarkable, although in general six‐membered rings with larger DI values also have more negative NICS indices. We have shown that this index can also be applied, with some modifications, to study of the aromaticity in five‐membered rings.
3,3′‐ and 4,4′‐Dimethoxy‐2,2′‐bipyrroles: Highly Electron‐Rich Model Compounds for Polypyrrole Formation.
Authors: Merz Andreas , Anikin Sergiy , Lieser Bernd , Heinze Jürgen , John Hermann
Published: January 2003

3,3′‐Dimethoxy‐2,2′‐bipyrrole (1) and 4,4′‐dimethoxy‐2,2′‐bipyrrole (2) were obtained in short sequences and good yields fromN‐benzyl‐3‐hydroxypyrrole‐2,4‐dicarboxylic acid. The key intermediate leading to1is anN‐benzyl‐3‐methoxypyrrole, which is dimerized by lithiation and oxidation with NiCl2. The formation of2is achieved by a classical Ullmann coupling of diethyl 1‐benzyl‐2‐bromo‐4‐methoxypyrrole‐3,5‐dicarboxylate. TheN‐benzyl protection groups of1and2are cleaved under reducing conditions with sodium in liquid ammonia. Both isomeric bipyrroles are extremely sensitive toward air. Compound1has a very low oxidation potential of 0.09 V against AgCl but film formation hardly occurs. On the other hand, compound2with a potential of 0.35 V readily forms stable polypyrrole films with anodic waves at −0.51 and −0.35 V and a cathodic wave at −0.77 V, the lowest potential ever observed for a p‐doped polymer.
Theoretical and Photoluminescence Studies on the d10–s2 AuI–TlI Interaction in Extended Unsupported Chains
Authors: Fernández Eduardo J. , Laguna Antonio , López‐de‐Luzuriaga José M. , Mendizabal Fernando , Monge Miguel , Olmos M. Elena , Pérez Javier
Published: January 2003

The reactions of solutions of TlPF6 and OPPh3 in tetrahydrofuran or acetone with NBu4[AuR2] (R=C6Cl5, C6F5) gave the new complexes [Au(C6Cl5)2]2[Tl(OPPh3)][Tl(OPPh3)(L)] (L=THF (1), acetone (2)) and the previously reported [Tl(OPPh3)2][Au(C6F5)2] (3). The crystal structures of complexes 1 and 2 display extended unsupported chains with short intermolecular interactions between alternating gold(I) and thallium(I) centres. Moreover, the TlI centres show two different types of geometrical environments, such as pseudotetrahedral and distorted trigonal‐bipyramidal, due to the presence of solvent molecules that act as ligands in the solid‐state structure. Quasirelativistic and nonrelativistic ab initio calculations were performed to study the nature of the intermetallic AuI–TlI interactions and are consistent with the presence of a high ionic contribution (80 %) and dispersion‐type (van der Waals) interaction with a charge‐transfer contribution (20 %) when relativistic effects are taken into account. All complexes are luminescent in the solid state at room temperature and at 77 K. Complexes 1 and 2 show site‐selective excitation, probably due to the different environments around the TlI centres. The DFT and time‐dependent (TD)‐DFT calculations are in agreement with the experimental excitation spectra for all complexes and confirm the site‐selective excitation behaviour as a function of the TlI geometrical environment.
Synthesis, Photophysical and Electrochemical Properties, and Biological Labeling Studies of Cyclometalated Iridium(III) Bis(pyridylbenzaldehyde) Complexes: Novel Luminescent Cross‐Linkers for Biomolecules
Authors: Lo Kenneth Kam‐Wing , Chung Chi‐Keung , Zhu Nianyong
Published: January 2003

We report the synthesis, characterization, photophysical, and electrochemical properties of a series of luminescent cyclometalated iridium(III) complexes containing two aldehyde functional groups [Ir(pba)2(N–N)](PF6) (Hpba=4‐(2‐pyridyl)benzaldehyde; N–N=2,2′‐bipyridine, bpy (1), 1,10‐phenanthroline, phen (2), 3,4,7,8‐tetramethyl‐1,10‐phenanthroline, 3,4,7,8‐Me4‐phen (3), 4,7‐diphenyl‐1,10‐phenanthroline, 4,7‐Ph2‐phen (4)). The X‐ray crystal structure of complex 1 has been investigated. Upon photoexcitation, complexes 1–4 exhibit intense and long‐lived emission in fluid solutions at 298 K and in low‐temperature glass. The luminescence is assigned to a triplet intra‐ligand (3IL) excited state associated with the pba− ligand, probably with mixing of some triplet metal‐to‐ligand charge‐transfer (3MLCT) (dπ(Ir)→π*(pba−)) character. Since each of these complexes possesses two aldehyde groups, which can react with the primary amine groups of biomolecules to form stable secondary amines after reductive amination, we have investigated the possibility of these complexes as novel luminescent cross‐linkers for biological substrates. L‐Alanine has been labeled with complexes 1–4 to give the luminescent bioconjugates 1‐(Ala)2–4‐(Ala)2. These conjugates show strong photoluminescence with long emission lifetimes under ambient conditions. On the basis of the emission energy trend, the excited state of these luminescent bioconjugates is likely to bear a high parentage of 3MLCT (dπ(Ir)→π*(N–N)) character. In addition, the glycoprotein avidin (Av) has also been conjugated with complexes 1–4 to give the bioconjugates 1‐Av–4‐Av. Upon photoexcitation, these bioconjugates also display intense and long‐lived 3MLCT (dπ(Ir)→π*(N–N)) emission in aqueous buffer at 298 K. Furthermore, a heterogeneous competitive assay for biotin has been developed using 2‐Av and biotinylated microspheres. We have shown that complexes 1–4 represent a new class of multicolor luminescent cross‐linkers for biomolecular species.
Substituent Effects on OH Bond Dissociation Enthalpies and Ionization Potentials of Catechols: A DFT Study and Its Implications in the Rational Design of Phenolic Antioxidants and Elucidation of Structure–Activity Relationships for Flavonoid Antioxidants
Authors: Zhang Hong‐Yu , Sun You‐Min , Wang Xiu‐Li
Published: January 2003

Density functional theory (DFT) on B3LYP/6‐31G(d,p) level was employed to investigate the substituent effects on OH bond dissociation enthalpies (BDEs) and ionization potentials (IPs) of catechols. It was revealed that the ortho hydroxyl of catechol was effective for the reduction of the OH BDE; however, the group had little influence on the IP. The para substituent effects upon OH BDEs and IPs for catechols were roughly the same as those for monophenols, and this gave the catechol moiety more potential than monophenol to be used as a lead compound in rational design of phenolic antioxidants. In addition, the 1,4‐pyrone effects on OH BDEs of catecholic rings A or B of flavonoids were also investigated. Although 1,4‐pyrone extended the conjugation system of flavonoids, it was not beneficial to reduce the OH BDE as a result of its electron‐withdrawing property. Thus, 1,4‐pyrone was unlikely to be favorable to enhance the H‐abstraction activity of flavonoids.
Synthesis and Structural Analysis of the Polymetallated Alkali Calixarenes [M4(p‐tert‐butylcalix[4]arene‐4H)(thf)x]2⋅n THF (M=Li, K; n=6 or 1; x=4 or 5) and [Li2(p‐tert‐butylcalix[4]arene‐2H)(H2O)(μ‐H2O)(thf)]⋅3 THF
Authors: Gueneau Estelle D. , Fromm Katharina M. , Goesmann H.
Published: January 2003

To study the structures and reactivities of alkali metallated intermediates of calix[4]arenes, three compounds were isolated: [Li4(p‐tert‐butylcalix[4]arene‐4H)(thf)4]2⋅6 THF (1), [Li2(p‐tert‐butylcalix[4]arene‐2H)(H2O)(μ‐H2O)(thf)]⋅3 THF (2), and [K4(p‐tert‐butylcalix[4]arene‐4H)(thf)5]2⋅THF (3). The structure of 1 is shown to be dependent on the coordinating solvent. Partial hydrolysis of 1 leads to the formation of 2. The potassium compound 3 features a different structure to that of 1, due to a higher coordination number as well as stronger cation–π‐bonding interactions.
Reagent‐Controlled Stereoselectivity in Titanocene‐Catalyzed Epoxide Openings: Reductions and Intermolecular Additions to α,β‐Unsaturated Carbonyl Compounds
Authors: Gansäuer Andreas , Bluhm Harald , Rinker Björn , Narayan Sanjay , Schick Michael , Lauterbach Thorsten , Pierobon Marianna
Published: January 2003

The generation and addition reactions of metal bound radicals derived from normal and meso epoxides by electron transfer from titanocene(III) reagents is described. The control of enantioselectivity and diastereoselectivity of these transformations is investigated by variation of the ligands of the metal complex. The reaction can lead to unprecedented and highly selective reactions, in which synthetically useful alcohols may be prepared. The synthesis presented also circumvents the use of toxic metals. Another advantage is that there is no loss of two functional groups as usually observed in reductive radical chain reactions.
Dynamic Chirality: Keen Selection in the Face of Stereochemical Diversity in Mechanically Bonded Compounds
Authors: Tseng Hsian‐Rong , Vignon Scott A. , Celestre Paul C. , Stoddart J. Fraser , White Andrew J. P. , Williams David J.
Published: January 2003

The template‐directed syntheses, employing bisparaphenylene‐[34]crown‐10 (BPP34C10), 1,5‐dinaphthoparaphenylene‐[36]crown‐10 (1/5NPPP36C10), and 1,5‐dinaphtho‐[38]crown‐10 (1/5DNP38C10) as templates, of three [2]catenanes, whereby one of the two bipyridinium units in cyclobis(paraquat‐p‐phenylene) is replaced by a bipicolinium unit, are described. The crude reaction mixtures comprising the [2]catenanes all contain slightly more of the homologous [3]catenanes, wherein a “dimeric” octacationic cyclophane has the crown ether macrocycles encircling the alternating bipyridinium units with the bipicolinium units completely unfettered. X‐ray crystallography, performed on all three [2]catenanes and two of the three [3]catenanes reveals co‐conformational and stereochemical preferences that are stark and pronounced. Both the [3]catenanes crystallize as mixtures of diastereoisomers on account of the axial chirality associated with the picolinium units in the solid state. Dynamic 1H NMR spectroscopy is employed to probe in solution the relative energy barriers for rotations by the phenylene and pyridinium rings in the tetracationic cyclophane component of the [2]catenanes. Where there are co‐conformational changes that are stereochemically “allowed”, crown ether circumrotation and rocking processes are also investigated for the relative rates of their occurrence. The outcome is one whereby the three [2]catenanes containing BPP34C10, 1/5NPPP36C10, and 1/5DNP38C10 exist as one major enantiomeric pair of diastereoisomers amongst two, four, and eight diastereoisomeric pairs of enantiomers, respectively. The diastereoisomerism is a consequence of the presence of axial chirality together with helical and/or planar chirality in the same interlocked molecule. These [2]catenanes constitute a rich reserve of new stereochemical types that might be tapped for their switching and mechanical properties.
Expression of PTPRO during mouse development suggests involvement in axonogenesis and differentiation of NT‐3 and NGF‐dependent neurons
Authors: Beltran Pedro J. , Bixby John L. , Masters Brian A.
Published: January 2003

Competition and cooperation between type II and type III receptor protein tyrosine phosphatases (RPTPs) regulate axon extension and pathfinding in Drosophila. The first step to investigate whether RPTPs influence axon growth in the more complex vertebrate nervous system is to identify which neurons express a particular RPTP. We studied the expression of mouse PTPRO, a type III RPTP with an extracellular region containing eight fibronectin type III domains, during embryogenesis and after birth. Mouse PTPRO mRNA is expressed exclusively in two cell types: neurons and kidney podocytes. Maximal expression in the brain was coincident with mid to late gestation and axonogenesis in the brain. We cloned two cDNAs, including a splice variant without sequence coding of 28 amino acids within the juxtamembrane domain that was found mostly in kidney. In situ hybridization detected mPTPRO mRNA in the cerebral cortex, olfactory bulb and nucleus, hippocampus, motor neurons, and the spinal cord midline. In addition, mPTPRO mRNA was found throughout dorsal root, cranial, and sympathetic ganglia and within kidney glomeruli. Mouse PTPRO mRNA was observed in neuron populations expressing TrkA, the high‐affinity nerve growth factor receptor, or TrkC, the neurotrophin‐3 receptor, and immunoreactive mPTPRO and TrkC colocalized in large dorsal root ganglia proprioceptive neurons. Our results suggest that mPTPRO is involved in the differentiation and axonogenesis of central and peripheral nervous system neurons, where it is in a position to modulate intracellular responses to neurotrophin‐3 and/or nerve growth factor. J. Comp. Neurol. 456:384–395, 2003. © 2003 Wiley‐Liss, Inc.
Tenascin‐R–deficient mice show structural alterations of symmetric perisomatic synapses in the CA1 region of the hippocampus
Authors: Nikonenko Alexander , Schmidt Sandra , Skibo Galina , Brückner Gert , Schachner Melitta
Published: January 2003

Accumulating evidence suggests that extracellular matrix (ECM) molecules play important roles in formation of synapses. Our previous electrophysiologic study of mice deficient in the extracellular matrix glycoprotein tenascin‐R (TN‐R) showed an impaired γ‐aminobutyric acid release at perisomatic inhibitory synapses in the CA1 pyramidal cell layer of the hippocampus. The present study investigated possible ultrastructural correlates of abnormal perisomatic inhibition. Topographic, morphometric, and stereologic methods were applied at the light and electron microscopic levels to quantify the density and spatial arrangement of cell bodies of CA1 pyramidal neurons and density and architecture of symmetric synapses formed on them in TN‐R−/− and wild‐type mice of different ages. The spatial arrangement of neuronal cell bodies in the CA1 pyramidal cell layer was found more diffuse and disordered in TN‐R−/− mice than in wild‐type animals. The coverage of the plasma membrane of pyramidal cell bodies by active zones of symmetric synapses was reduced by at least 40% in TN‐R−/− animals compared with control animals. Further, the length of active zone profiles of perisomatic inhibitory synapses in the CA1 pyramidal cell layer was 8–14% smaller, whereas the number of active zones calculated per length unit of cell body profile was 30–40% smaller in TN‐R mutants than in wild‐type animals. The density and spatial arrangement of synaptic vesicles in the synaptic terminals provided ultrastructural evidence for reduced synaptic activity in TN‐R mutants. Thus, TN‐R appears to play an important role in the regulation of the number and architecture of perisomatic inhibitory synapses, which play crucial roles in the synchronization of neuronal activity and modulation of synaptic plasticity in the hippocampus. J. Comp. Neurol. 456:338–349, 2003. © 2003 Wiley‐Liss, Inc.
Quantifying subjective assessment of sleep and life‐quality in antidepressant‐treated depressed patients
Authors: Mayers Andrew G. , van Hooff Johanna C. , Baldwin David S.
Published: January 2003

This study sought to establish a method of quantifying subjective perceptions of sleep against perceptions of life‐quality and mood, using amended versions of the Pittsburgh sleep diary (PghSD) and quality of life of insomniacs (QOLI) questionnaire. Diaries and questionnaires were self‐completed in participants' homes. Outpatients with a DSM‐IV diagnosis of major depressive disorder were compared with a healthy control group (with no history, or family history, of depression). Poorer sleepers, as determined by the sleep diary, were significantly more likely to report poorer life‐quality and mood perceptions on the subsequent questionnaire. Furthermore, the depressed group reported significantly poorer perceptions of sleep quality and poorer perceptions of life‐quality and mood than the control group, even though estimates of sleep disturbance were similar. This may indicate that depressed individuals experience more ‘sleep distress’ than healthy individuals. These results confirm the extent of subjectively reported sleep disruption in depression and demonstrate the merit of combining the amended PghSD and QOLI to quantify sleep perceptions. Copyright © 2002 John Wiley & Sons, Ltd. Copyright © 2002 John Wiley & Sons, Ltd.
Subjective assessment of the effects of CNS‐active drugs on sleep by the Leeds sleep evaluation questionnaire: a review
Authors: Zisapel N. , Laudon M.
Published: January 2003

The Leeds sleep evaluation questionnaire (LSEQ) comprises ten self‐rating 100 mm line analogue questions concerned with sleep and early morning behaviour. A literature search identified 83 studies in peer‐reviewed journals that reported the use of the LSEQ for psychopharmacological investigations of drug effects on self‐reported aspects of sleep. High internal consistency and reliability of the questionnaire have been demonstrated. Findings from studies involving a variety of psychoactive agents indicated that the LSEQ was able to quantify subjective impressions of sleep and waking and the effects of drugs in healthy volunteers, depressed and insomnia patients.

In accordance with their known activity profile nocturnal administration of sedative hypnotic agents and antihistamines induced dose‐related improvements in self‐reported ease of getting to sleep, and quality of sleep but a decrease in alertness and behavioural integrity the following morning. Psychostimulants, on the other hand, impaired subjective ratings of sleep and increased early morning alertness. Antidepressants and certain anxiolytic agents improved both self‐reported sleep aspects and early morning alertness. Treatment effects measured by the LSEQ corresponded to those measured for the same drugs by other assessment methods.

These data indicate that the LSEQ is a robust and reliable instrument for psychopharmacological evaluations. Self‐evaluations of sleep, as obtained by the LSEQ, can therefore provide consistent and meaningful measures for estimating the effectiveness of sleep modulators and sedative‐hypnotic drugs. Copyright © 2003 John Wiley & Sons, Ltd.
8q24 Copy number gains and expression of the c‐myc mRNA stabilizing protein CRD‐BP in primary breast carcinomas
Authors: Ioannidis Panayotis , Mahaira Louisa , Papadopoulou Anna , Teixeira Manuel R. , Heim Sverre , Andersen Johan A. , Evangelou Evangelos , Dafni Urania , Pandis Nikos , Trangas Theoni
Published: January 2003

The coding region determinant binding protein (CRD‐BP) was isolated by virtue of its high affinity to the c‐myc mRNA coding region stability determinant and shown to shield this message from nucleolytic attack, prolonging its half‐life. CRD‐BP is normally expressed during fetal life but is also activated de novo in tumors. Considering that aberrant CRD‐BP expression may represent an additional mechanism interfering with c‐myc regulation, we screened 118 primary breast carcinomas for CRD‐BP expression, 60 of which had also been analyzed by comparative genomic hybridization (CGH). Copy number gains encompassing 8q24, the chromosome band that contains the c‐myc locus, were detected in 48.3% (29/60) of tumors, whereas gains involving band 17q21, which contains the CRD‐BP locus, were observed in 18.3% (11/60) of tumors. CRD‐BP expression was detected in 58.5% (69/118) of tumors, implying mechanisms of activation alternative to gene amplification. Altogether, some 75% of the tumors had alterations pertaining to c‐myc since they either harbored 8q24 gains and/or expressed CRD‐BP. Significant associations were detected between CRD‐BP expression and the absence of estrogen receptors (p = 0.005) and between the presence of 8q24 gains and an increased number of genomic changes as measured by CGH (p = 0.0017). Tumors were divided into 4 groups according to CRD‐BP expression and 8q24 gains. The odds for tumors having both characteristics to be classified as poorly differentiated (grade III vs. grade I and II) were 19.6 times the corresponding odds for tumors neither expressing CRD‐BP nor harboring 8q24 gains. For tumors either harboring 8q24 gains only or expressing CRD‐BP alone, the corresponding odds were 6.4 and 3, respectively. © 2002 Wiley‐Liss, Inc.
Relationship between E‐cadherin gene mutation and p53 gene mutation, p53 accumulation, Bcl‐2 expression and Ki‐67 staining in diffuse‐type gastric carcinoma
Authors: Fricke Elena , Keller Gisela , Becker Ingrid , Rosivatz Erika , Schott Christina , Plaschke Susanne , Rudelius Martina , Hermannstädter Christine , Busch Raymonde , Höfler Heinz , Becker Karl‐Friedrich , Luber Birgit
Published: January 2003

E‐cadherin mutations are found in 50% of diffuse‐type gastric carcinoma, but not in intestinal gastric carcinoma. Because cell–cell adhesion mediated by E‐cadherin plays an important role in epithelial cell survival, E‐cadherin mutations could alter the apoptotic behavior of tumor cells. p53 and Bcl‐2 family members are also important regulators of cellular apoptosis. This is the first study that investigates the relationship between E‐cadherin gene mutation and p53 gene mutation, p53 accumulation, Bcl‐2 expression, and Ki‐67 expression in diffuse‐type gastric carcinoma (24 cases, E‐cadherin mutation status: wild‐type in 8 patients and mutant in 16 patients). The mutation status of exons 5–8 of p53 was analyzed by denaturing high pressure liquid chromatography (DHPLC) in formalin‐fixed, paraffin‐embedded tumor sections, followed by direct sequencing of cases with aberrant chromatographic patterns. p53 mutations were found in 1 of 8 tumors without E‐cadherin mutation (12.5%) and in 1 of 16 tumors with E‐cadherin mutation (6.3%), a difference that was not statistically significant (p = 1.00). p53 accumulation was found in 8 of 24 tumors (33.3%) by immunohistochemical staining. p53 accumulation was significantly more frequent in tumors without E‐cadherin mutations (5 of 8 tumors, 62.5%) than in gastric carcinoma tissues with E‐cadherin mutations (3 of 16 tumors, 18.8%, p = 0.03). Bcl‐2 staining was not observed in gastric carcinoma cells without E‐cadherin mutations, but was detectable in 5 of 16 tumors with E‐cadherin mutations (31.3%), a difference that was not statistically significant (p = 0.13). No relationship was observed between Ki‐67 staining and the E‐cadherin mutation status (p = 1.00). These data suggest that the presence of E‐cadherin mutations can significantly alter the accumulation of the apoptose‐regulating p53 protein, whereas no correlation with the p53 mutation status or with Ki‐67 staining was observed. © 2002 Wiley‐Liss, Inc.
Age‐dependent variations of human and rat colon myofibroblasts in culture: Influence on their functional interactions with colon cancer cells
Authors: Pourreyron Céline , Dumortier Jérôme , Ratineau Christelle , Nejjari Mimoun , Beatrix Olivier , Jacquier Marie‐France , Remy Lionel , Chayvialle Jean‐Alain , Scoazec Jean‐Yves
Published: January 2003

Epithelial–mesenchymal interactions play a pivotal role in colon cancer invasion and metastasis. We aimed at elucidating the impact of long‐term cultivation on the phenotypic and functional characteristics of primary fibroblasts and their interaction with the human colon adenocarcinoma cell line LoVoC5. We used fibroblasts from human colon tumor tissue, normal human colon mucosa, rat normal colon and 2 rat colon‐derived myofibroblast cell lines, MIC316 and MG. The following parameters were studied: cell shape and size, growth curve, intermediate filament expression and extracellular matrix synthesis. Coculture models with or without cell contacts were used to test the effects on LoVoC5 cell proliferation, spreading and adhesion. Irrespective of their origin, fibroblastic cells in primary cultures presented marked phenotypic and functional changes with time. Before passage 5, they presented as large, slow‐growing cells expressing vimentin and α‐smooth muscle actin; synthesizing laminin‐1, fibronectin and collagens I and IV; and inducing LoVoC5 proliferation, spreading and adhesion. After passage 15, they presented as small, fast‐growing cells inconstantly expressing α‐smooth muscle actin and synthesizing mainly type I collagen. In coculture with or without cell contacts, they inhibited LoVoC5 proliferation and allowed only limited cell spreading and adhesion. Myofibroblastic cell lines presented as large, fast‐growing cells expressing vimentin and α‐smooth muscle actin and synthesizing mainly type I collagen. They had no significant effects on LoVoC5 proliferation, spreading and adhesion. Our results underline the importance of age‐dependent variations in colon mesenchymal cells in culture and for the in vitro study of epithelial–mesenchymal interactions in colon cancer. © 2002 Wiley‐Liss, Inc.