bluuebunny/crossref_metadata_2025 huggingface dataset:
2. PENGARUH MEDIA SOSIAL TERHADAP INDEKS PRESTASI KADET MAHASISWA STRATA SATU FAKULTAS SAINS DAN TEKNOLOGI PERTAHANAN UNHAN RI
Authors: Lediwara Nadiza , Aulia Khamas Heikmakhtiar  , Sembada Denrineksa Bimorogo  , Hondor Saragih  , Ricky Chan  , Zefanya Seto Gandhara
Published: April 2024

Pengunaan media sosial merupakan suatu hal yang lumrah pada era serbateknologi ini. begitu juga penggunaan media sosial yang digunakan oleh kadet mahasiswadi universitas pertahanan republik indonesia. Namun, penggunaan media sosial bisa jugamenjadi dampak negatif yang dapat mempengaruhi indeks prestasi kumulatif (IPK). Tujuandari penelitian ini adalah untuk mengetahui apakah ada hubungan antara penggunaan mediasosial terhadap indeks prestasi kumulatif (IPK) kadet mahasiswa. Hubungan antara variabeldiuji dengan hipotesis asosiatif. Dari hasil penelitian didapatkah bahwa antara penggunaanmedia sosial tidak mempengaruhi indeks prestasi kumulatif (IPK).
4. ANALISIS CFD PERFORMA AERODINAMIKA MODEL SAYAP X PADA PESAWAT TERBANG RADIO CONTROLLED UNTUK AEROMODELLING TARUNA AAU
Authors: Firmanto Bondhan , Dylan Aminto Syahid  , M. Abdul Ghofur
Published: April 2024

Pesawat terbang radio controlled yang digunakan pada kegiatan aeromodellingTaruna AAU sejatinya adalah sebuah model dari pesawat terbang yang sebenarnya. Prosespembuatannya juga menyerupai proses pembuatan pesawat terbang yang sebenarnya antaralain tahap perencanaan, perancangan, pembuatan, sampai dengan uji terbang. Sebelumpesawat model tersebut diuji terbang, perlu dilakukan analisis karakter aerodinamika pesawatterbang khususnya sayap karena sayap mampu menghasilkan gaya angkat yang palingbesar. Pada penelitian ini akan dianalisis karakter aerodinamika model sayap rectangularstraight dan sayap X dengan tujuan untuk mengetahui dan menentukan model sayap yangpaling tepat digunakan pada pesawat terbang radio controlled untuk aeromodelling TarunaAAU. Analisis aerodinamika dilakukan secara numerik menggunakan paket perangkatlunak ANSYS Student 2022R1. Domain komputasi dibuat dengan perangkat lunak ANSYSDesignModeler. Model 3D sayap menggunakan penampang airfoil NACA 2812. Mesh dibuatdengan perangkat lunak ANSYS Meshing. Simulasi menggunakan perangkat lunak ANSYSFluent dengan variasi sudut serang -10°, -5°, 0°, 5° dan 10°, serta kecepatan aliran fluida5,56 m/s dan 8,33 m/s. Model turbulen yang digunakan adalah κ-omega SST pada kondisitransient, incompressible, subsonic, dan sea level. Analisis dititikberatkan pada performaaerodinamika CL, CD, CL/CD dan visualisasi aliran. Hasil penelitian menunjukkan bahwadengan bertambah nya angle of attack dan kecepatan udara, model sayap rectangularstraight dan sayap X mengalami kenaikan lift dan drag serta mengalami penurunan liftto drag ratio. Model sayap rectangular straight memiliki keunggulan geometri yang lebihsederhana dan dapat menghasilkan lift to drag ratio pada posisi sudut serang 0° yang lebihbesar daripada model sayap X yaitu sebesar 11,7. Model sayap rectangular straight dinilailebih tepat digunakan pada pesawat terbang radio controlled untuk aeromodelling TarunaAAU mengingat geometri sayap yang lebih sederhana sehingga lebih mudah dibuat danmemberikan performa aerodinamika yang lebih baik.
民办高职院校图书管理员素质建设与提升探析
Authors: 孔祥通  , 许文娟  , 孔令红  , 朱长利  , 陈祥雨
Published: April 2024

孔祥通1，许文娟1，孔令红1，朱长利1，陈祥雨2
1.曲阜远东职业技术学院，山东曲阜；
2.齐鲁理工学院，山东济南
摘要：在现代社会发展新形势下，各个行业领域也紧随时代发展的步伐进行创新及改革，以使得自身发展能够适应社会的发展潮流，而对于民办类高职院校图书管理员来说也不例外。图书管理员们自身所具备的专业素养以及业务能力对民办高校图书馆的利用率产生一定影响，因此，需要提高对民办高职院校图书管理员整体素质的重视程度，使得图书管理员们自身的能力能够满足学院图书馆管理工作的需求。
翻转课堂教学在新能源领域的改革探索
Authors: 崔小华  , 王志伟
Published: April 2024

崔小华1，王志伟2
1.曲阜远东职业技术学院，山东曲阜；
2.山东圣阳电源股份有限公司，山东济宁
摘要：课程的教学探索在翻转式课堂和过程式考核上取得一定的成果，对学生知识、能力、素质的培养起到了积极的作用，同时，对毕业设计的文献检索、论文撰写、PPT制作、答辩等进行训练，为下学期毕业设计的开展打下了基础。本课程教学改革过程仍存在不足，如部分学生参与的积极性不够、极少数学生照本宣科，没有深入研究，这是我们下一步需解决的问题。同时，随着互联网技术的发展，未来课程页可以开设为线上模式或线上线下混合式教学模式等。本课程的教学探索为其他专业课的教学方法改革奠定了基础。
Molecular target identification of two Coleus amboinicus leaf isolates toward lung cancer using a bioinformatic approach and molecular docking-based assessment
Authors: Haryadi Winarto , Gurning Kasta , Astuti Endang
Published: April 2024

Lung cancer raises a serious concern because of its position as the second global deathliest disease in both men and women. Conventional treatments emphasize chemotherapy and radiation or their combination, which is considered to be ineffective due to harmful side effects in patients. In this work, we did a bioinformatic investigation using the pharmacological network and molecular docking approaches to evaluate the potency of natural compounds isolated from the leaves of Coleus amboinicus, Lour, i.e., 16-hydroxy-7α-acetoxyroyleanone and 16-acetoxy- 7α-hydroxyroyleanone. The activity of both active compounds against lung cancer was predicted using disease databases and genes. A total of 77 core targets were identified from the analysis using STRING and built using Cytoscape. Gene ontology, and Kyoto encyclopedia of genes, and genome analysis of cancer pathways targeting PGTS2 and peroxisome proliferator-activated receptor gamma were employed because of their critical functions in cancer therapy. The validated molecular docking analysis illustrates the possibility of interactions that occur between active compounds of target proteins in the treatment of lung cancer. This research has not yet been able to demonstrate its potential in the treatment of lung cancer, and further research is needed to prove it through in vitro and in vivo examinations before pre-clinical and clinical tests in the future.
Optimal transport for automatic alignment of untargeted metabolomic data
Authors: Breeur Marie , Stepaniants George , Keski-Rahkonen Pekka , Rigollet Philippe , Viallon Vivian
Published: April 2024

Untargeted metabolomic profiling through liquid chromatography-mass spectrometry (LC-MS) measures a vast array of metabolites within biospecimens, advancing drug development, disease diagnosis, and risk prediction. However, the low throughput of LC-MS poses a major challenge for biomarker discovery, annotation, and experimental comparison, necessitating the merging of multiple datasets. Current data pooling methods encounter practical limitations due to their vulnerability to data variations and hyperparameter dependence. Here we introduce GromovMatcher, a flexible and user-friendly algorithm that automatically combines LC-MS datasets using optimal transport. By capitalizing on feature intensity correlation structures, GromovMatcher delivers superior alignment accuracy and robustness compared to existing approaches. This algorithm scales to thousands of features requiring minimal hyperparameter tuning. Applying our method to experimental patient studies of liver and pancreatic cancer, we discover shared metabolic features related to patient alcohol intake, demonstrating how GromovMatcher facilitates the search for biomarkers associated with lifestyle risk factors linked to several cancer types.
Heritable epigenetic changes are constrained by the dynamics of regulatory architectures
Authors: Jose Antony M
Published: April 2024

Interacting molecules create regulatory architectures that can persist despite turnover of molecules. Although epigenetic changes occur within the context of such architectures, there is limited understanding of how they can influence the heritability of changes. Here I develop criteria for the heritability of regulatory architectures and use quantitative simulations of interacting regulators parsed as entities, their sensors and the sensed properties to analyze how architectures influence heritable epigenetic changes. Information contained in regulatory architectures grows rapidly with the number of interacting molecules and its transmission requires positive feedback loops. While these architectures can recover after many epigenetic perturbations, some resulting changes can become permanently heritable. Such stable changes can (1) alter steady-state levels while preserving the architecture, (2) induce different architectures that persist for many generations, or (3) collapse the entire architecture. Architectures that are otherwise unstable can become heritable through periodic interactions with external regulators, which suggests that the evolution of mortal somatic lineages with cells that reproducibly interact with the immortal germ lineage could make a wider variety of regulatory architectures heritable. Differential inhibition of the positive feedback loops that transmit regulatory architectures across generations can explain the gene-specific differences in heritable RNA silencing observed in the nematode
C. elegans
, which range from permanent silencing to recovery from silencing within a few generations and subsequent resistance to silencing. More broadly, these results provide a foundation for analyzing the inheritance of epigenetic changes within the context of the regulatory architectures implemented using diverse molecules in different living systems.
Identification of novel microcephaly-linked protein ABBA that mediates cortical progenitor cell division and corticogenesis through NEDD9-RhoA
Authors: Carabalona Aurelie , Kallo Henna , Gonzalez Maryanne , Andriichuk Liliia , Elomaa Ellinoora , Molinari Florence , Fragkou Christiana , Lappalainen Pekka , Wessels Marja W , Saarikangas Juha , Rivera Claudio
Published: April 2024

The cerebral cortex, which is responsible for higher cognitive functions, relies on the coordinated asymmetric division cycles of polarized radial glial progenitor cells for proper development. Defects in the mitotic process of neuronal stem cells have been linked to the underlying causes of microcephaly; however, the exact mechanisms involved are not fully understood. In this study, we present a new discovery regarding the role of the membrane-deforming cytoskeletal regulator protein called Abba (also known as MTSS1L/MTSS2) in cortical development. When Abba was absent in the developing brain, it led to a halt in radial glial cell proliferation, disorganized radial fibers, and abnormal migration of neuronal progenitors. During cell division, Abba localized to the cleavage furrow, where it recruited the scaffolding protein Nedd9, and positively influenced the activity of RhoA, a crucial regulator of cell division. Notably, we identified a variant of Abba (R671W) in a patient with microcephaly and intellectual disability, further highlighting its significance. The introduction of this mutant Abba protein in mice resulted in phenotypic similarities to the effects of Abba knockdown. Overall, these findings offer valuable mechanistic insights into the development of microcephaly and the cerebral cortex by identifying Abba as a novel regulator involved in ensuring the accurate progression of mitosis in neuronal progenitor cells.
Mining the neuroimaging literature
Authors: Dockès Jérôme , Oudyk Kendra , Torabi Mohammad , de la Vega Alejandro I , Poline Jean-Baptiste
Published: April 2024

Automated analysis of the biomedical literature (
literature-mining
) offers a rich source of insights. However, such analysis requires collecting a large number of articles and extracting and processing their content. This task is often prohibitively difficult and time-consuming. Here, we provide tools to easily collect, process and annotate the biomedical literature. In particular, pubget is an efficient and reliable command-line tool for downloading articles in bulk from PubMed Central, extracting their contents and meta-data into convenient formats, and extracting and analyzing information such as stereotactic brain coordinates. Labelbuddy is a lightweight local application for annotating text, which facilitates the extraction of complex information or the creation of ground-truth labels to validate automated information extraction methods. Further, we describe repositories where researchers can share their analysis code and their manual annotations in a format that facilitates re-use. These resources can help streamline text-mining and meta-science projects and make text-mining of the biomedical literature more accessible, effective, and reproducible. We describe a typical workflow based on these tools and illustrate it with several example projects.
Um estudo sobre a utilização da dispensa de licitação para compras e contratações de produtos para pesquisa e desenvolvimento
Authors: Silva Eduardo Fialho , Barbosa Josiane Dantas Viana , Ribeiro Filipe da Cruz , Murari Thiago Barros
Published: April 2024

Este artigo buscou avaliar a dinâmica de utilização da nova dispensa de licitação para compras e contratações de produtos para pesquisa e desenvolvimento, que foi criada para conferir maior flexibilidade e agilidade no suprimento de materiais, insumos e serviços para suporte aos projetos de pesquisa, desenvolvimento e inovação (PD&I) de Instituições de Ciência e Tecnologia (ICTs) públicas no Brasil. Embora a nova opção de dispensa e licitação demonstre potencial para influir positivamente na qualidade das atividades de PD&I, a amostra avaliada sugere que essa nova opção legal não vem sendo aproveitada pelas ICTs públicas federais, com possível comprometimento da eficiência e da economicidade nas compras e contratações para suporte aos projetos de PD&I.
The Spectrum of Deletion Pattern in the Dystrophin Gene in Duchenne Muscular Dystrophy Patients: A Cross-sectional Study from Northeast India
Authors: Rajkonwar Anjanjyoti , Baruah Jenita , Sarmah Binod , Kusre Giriraj , Shyam Gautam , Dutta Abhijit
Published: April 2024

Introduction: Duchenne Muscular Dystrophy (DMD) is an X-linked recessive neuromuscular disorder characterised by progressive, irreversible muscle weakness. It is caused by a mutation in the dystrophin or DMD gene, leading to the absence of the essential muscle protein Dystrophin in DMD. Muscle strength continually diminishes, and death usually occurs from chronic respiratory insufficiency and/or cardiac failure. Due to the high mortality rate, early diagnosis is crucial to allow appropriate planning for patient care and treatment. In India, the traditional multiplex Polymerase Chain Reaction (PCR) assay is the most common method to detect Dystrophin gene deletion mutations. Aim: To describe the spectrum of deletion patterns in the dystrophin gene in muscular dystrophy patients attending a tertiary care hospital in Northeast India. Materials and Methods: A hospital-based cross-sectional study was conducted on a total of 53 suspected DMD patients attending the Department of Neurology and Department of Paediatrics at Assam Medical College, Dibrugarh, Assam, India from January 2016 to December 2022. Multiplex PCR was performed to study the deletion patterns for the 25 most common exons of the DMD gene for all patients at the Genetic lab, Department of Anatomy. Deletion mutations at different multiple exons were found, and the results were statistically analysed using Statistical Package for Social Sciences (SPSS) to calculate the mean and standard deviation. The results were presented in tabular form as percentages. Results: Out of the 53 cases suspected to have DMD on the basis of clinical presentation and high serum Creatine Kinase (CK) levels, 34 patients (64.2%) showing deletion mutations in the 25 most common exons of the DMD gene were included in the study. Deletions were most common in 15 (44.1%) patients in the distal hotspot region of exons 44-55. The most common gene deleted was exon 50 in 11 (32.4%) patients. The age at which symptoms were noticed was 4.7±2.01 years. The mean age at diagnosis was 8.4±2.4 years. Conclusion: In the present study, most patients suspected of DMD based on clinical and laboratory findings had deletions in the DMD gene, with the most common region for deletion in the dystrophin gene being the distal hotspot region, and exon 50 being the most commonly deleted.
Efficacy of Thoracic Segmental Spinal Anaesthesia in Percutaneous Nephrolithotomy: A Retrospective Observational Study
Authors: Haloi Prajnananda , Biswas Rahul , Bora Ananta , Devi Santana
Published: April 2024

Introduction: Percutaneous Nephrolithotomy (PCNL) is a minimally invasive procedure for the treatment of renal stone disease, usually performed under General Anaesthesia (GA). Regional anaesthesia, specifically Thoracic Segmental Spinal Anaesthesia (TSSA), offers a suitable alternative to mitigate complications associated with GA. TSSA in PCNL has an advantage over conventional lumbar spinal anaesthesia in terms of better haemodynamic stability, attributed to the lesser amount of local anaesthetic drug required. However, its clinical utility is yet to be fully explored. Aim: To investigate the feasibility and efficacy of TSSA in patients undergoing PCNL by analysing their medical records. Materials and Methods: A retrospective observational study was conducted on 250 patients from January 2022 to July 2023 at GNRC Medical, Guwahati, India. Patients aged 20- 70 years with American Society of Anaesthesiology (ASA) I and II classification, undergoing PCNL with renal stones ≤40 mm, were included. TSSA was administered at the T9-T10 intervertebral space. Intraoperative parameters, degree of motor and sensory block, post-operative analgesia, patient and surgeon satisfaction were recorded. Descriptive statistics of the study were analysed in Microsoft excel and presented as mean with standard deviation or as numbers and percentages. Results: The patients in the study had a mean age of 41.08 years, Body Mass Index (BMI) of 25.52 kg/m2 , stone size of 25.73 mm, and surgical duration of 74.92 minutes. TSSA was associated with minimal intraoperative hypotension (6%) and bradycardia (8.9%), zero incidences of neurological complications, and did not require conversion to GA. Complete stone clearance was achieved in 89.6% of cases. Post-operative analgesia was excellent in 179 (71.6%) patients as they did not require any rescue analgesia within the first 24 hours. Patient and surgeon satisfaction were notably high. Conclusion: TSSA emerges as a safe and efficient alternative to GA in selected cases of PCNL. Patient and surgeon satisfaction, along with minimal post-operative complications, support its consideration and usage. However, the choice of anaesthesia should be individualised based on procedural complexities and patient characteristics.
The Attitudes of Emergency Department Nurses towards Patient Safety in Alqassim Region, Saudi Arabia: A Questionnairebased Cross-sectional Study
Authors: Albagawi Bander Saad
Published: April 2024

Introduction: Patient safety is a crucial aspect of healthcare delivery, and nurses play a critical role in ensuring that patients receive safe and high-quality care. As healthcare systems continue to evolve, it is essential to understand the attitudes and perceptions of nurses towards patient safety. Aim: To explore emergency department nurses’ attitudes toward patient safety in the Alqassim region, Saudi Arabia. Materials and Methods: This was a cross-sectional study involving 420 emergency department nurses from the hospitals of the Alqassim region, Saudi Arabia. The World Health Organisation (WHO) patient safety questionnaire, specifically tailored for nurses, was employed. Data analysis was conducted using Statistical Package for Social Sciences (SPSS) version 25.0. Results: Total of 139 nurses out 420 completed the research. Most participants were males aged between 22 and 30 years, married, and held a Bachelor of Science in Nursing (BSN) degree. The overall average score for patient safety reached a moderate level, with a mean of 118.66±23.33. The component on workplace safety had the highest average score of 32.33±7.40, while the section on personal attitudes towards patient safety had the lowest average score of 15.02±3.72. Conclusion: Nurses exhibited moderate attitudes towards various aspects of patient safety, including error and patient safety, healthcare system safety, and personal attitudes towards patient safety. Enhancing patient safety measures is crucial for fostering a resilient safety culture in the healthcare sector.
Effect of Pruning and Nutrient Levels on Plant Growth of Guava (Psidium guajava) cv. Allahabad Safeda under Meadow Orcharding Allahabad
Authors: Singh Arun Kumar , Singh Devi
Published: April 2024

A field experiment was conducted to evaluate the effect of pruning and nutrient levels on growth and yield of guava cv. Allahabad Safeda. The treatment consists of four different levels of pruning P0: 00.0cm (Un-pruned plants/ Without Pruning), P1: Pruned at 30cm of the shoot length, P2: Pruned at 40cm of the shoot length and P3: Pruned at 50cm of the shoot length and four different levels of nutrients (NPK) viz., F1: NPK (260:320:260 g/plant)  (Control), F2: NPK (220:280:300 g/plant), F3: NPK (300:360:300g/plant) and F4: NPK (340:400:340g/plant). The experiment comprising 16 treatment combinations was laid out in 2-factor Factorial Randomized Block Design (f-RBD) having three replications during 2014-2015 & 2015-2016. Among the different treatments T16:P3(P3: 50cm x F4: 340:400:340 g/plant) was best dose for optimum vegetative growth parameter viz., plant height (cm), number of branches per plant, number of leaves per plant, plant spread (n-s & e-w), stem diameter (mm), stem length (cm) and days to taken new shoot emergence of guava cv. Allahabad safeda.
Optimizing Weed Control: A Review of Integrated Weed Management in Mustard (Brassica juncea L.)
Authors: Yernaidu Y. , Reddy G. Rama Mohan , Sriram K. , Babu M E Krishna , Sravani P.
Published: April 2024

Mustard (Brassica juncea L.), a species of the cruciferous family, is the world's third most significant oilseed crop, following soybean and palm. Mustard seeds range in oil content from 37 to 49%. India is the fourth-largest producer of mustard and rapeseed in the world. The most significant issue causing mustard's low yield is weed control. Crop yields are significantly reduced by weeds; in the case of mustard, this can mean a complete failure rate of 15–30%. Crop plants compete with weeds for nutrients, sunlight, space, and water. In addition to lowering crop quality, weeds pose a number of nutritional and environmental hazards. In mustard crops, weed competition is particularly important in the early stages since the crop grows slowly in the first 4–8 weeks after sowing. On the other hand, 15–40 days are the critical window for crop–weed competition. Weed control must be carried out appropriately and on time in order to maximize mustard growth and production. During the early stages of crop growth, 25–30 days after sowing, the traditional practice of hand weeding once is insufficient because weeds always reappear after manual weeding, irrigation, or winter rainfall. More importantly, though, is that these weeds drain a large amount of the soil's moisture and nutrients. Though hand weeding mustard is simple, the expense of doing so is significant due to the scarcity of labor at the appropriate time and the uncontrolled growth of various intra row weeds. Weeds may become tolerant of herbicides despite their regular and high dosage application. Therefore, combined approaches could be the best option to control the complex weed flora in mustard.
Ambient air pollution and risk for ischemic stroke and transient ischemic attack
Authors: Lisabeth Lynda D. , Escobar James D. , Dvonch J. Timothy , Sánchez Brisa N. , Majersik Jennifer J. , Brown Devin L. , Smith Melinda A. , Morgenstern Lewis B.
Published: May 2008

Objective

Data on the association between air pollution and cerebrovascular disease in the United States are limited. The objective of this study was to investigate the association between short‐term exposure to ambient air pollution and risk for ischemic cerebrovascular events in a US community.

Methods

Daily counts of ischemic strokes/transient ischemic attacks (TIAs) (2001–2005) were obtained from the population‐based Brain Attack Surveillance in Corpus Christi (BASIC) Project. Daily particulate matter less than 2.5μm in diameter (PM2.5), ozone (O3), and meteorological data were obtained from Texas Commission on Environmental Quality. To examine the association between PM2.5and stroke/TIA risk, we used Poisson regression. Separate models included same‐day PM2.5, PM2.5lagged 1 to 5 days, and an averaged lag effect. All models were adjusted for temperature, day of week, and temporal trends in stroke/TIA. The effects of O3were also investigated.

Results

Median PM2.5was 7.0μg/m3(interquartile range, 4.8–10.0μg/m3). There were borderline significant associations between same‐day (relative risk [RR], 1.03; 95% confidence interval [CI], 0.99–1.07 for an interquartile range increase in PM2.5) and previous‐day (RR, 1.03; 95% CI, 1.00–1.07) PM2.5and stroke/TIA risk. These associations were independent of O3, which demonstrated similar associations with stroke/TIA risk (same‐day RR, 1.02; 95% CI, 0.97–1.08; previous‐day RR, 1.04; 95% CI, 0.99–1.09).

Interpretation

We observed associations between recent PM2.5and O3exposure and ischemic stroke/TIA risk even in this community with relatively low pollutant levels. This study provides data on environmental exposures and stroke risk in the United States, and suggests future research on ambient air pollution and stroke is warranted. Ann Neurol 2008
Organotin(IV) carboxylates of cyclopropane carboxylic acid and 3‐cyclohexylpropanoic acid: synthesis, characterization and biological activity. The crystal structure of bis(cyclopropanecarboxylato) tetramethyldistannoxane
Authors: Sarma Moumita Sen , Saha Aniruddha , Roy Abhijit
Published: May 2008

A series of tri‐ and di‐organotin(IV) derivatives of the types R3SnL, R2SnL2 and [(R2SnL)2O]2 have been synthesized by the reaction of tri‐ and di‐organotin(IV) chloride(s) with sodium cyclopropane carboxylate and sodium 3‐cyclohexylpropanoate. Based on spectroscopic evidence (IR and NMR), all the triorganotin carboxylates were found to be penta‐coordinated in the solid state (except the tricyclohexyltin derivative, which was found to be four‐coordinated) and four‐coordinated in the solution state. Attempted reaction of Me2SnCl2 with sodium cyclopropane carboxylate in 1:2 stoichiometry afforded a bis(dicarboxylato tetraorganodistannoxane) complex, {[Me2Sn(cyclo‐CH2)2CHCOO]2O}2. The X‐ray diffraction of this ‘dimethyltin(IV) complex’ shows that the compound possesses a tetranuclear aggregate with one bridging bidentate and other free organic ester type monodentate carboxylate groups in which each Sn atom has a five‐coordinated geometry. These complexes were also screened for their antifungal activities. Copyright © 2008 John Wiley & Sons, Ltd.
Synthesis and structure of novel spirosilanes. Combination of 1,2‐hydroboration and 1,1‐organoboration
Authors: Wrackmeyer Bernd , Khan Ezzat , Kempe Rhett
Published: May 2008

The reaction of tetra(alkyn‐1‐yl)silanes Si(CC‐R1)4 1 [R1 = tBu (a), Ph (b), C6H4‐4‐Me (c)] with 9‐borabicyclo[3.3.1]nonane (9‐BBN) in a 1:2 ratio affords the spirosilane derivatives 5a–c as a result of twofold intermolecular 1,2‐hydroboration, followed by twofold intramolecular 1,1‐organoboration. Intermediates 3a–c, in which two alkenyl‐ and two alkyn‐1‐yl groups are linked to silicon, were identified by NMR spectroscopy. The molecular structure of the spiro compound 5c was determined by X‐ray analysis, and the solution‐state structures of products and intermediates follow conclusively from the consistent NMR spectroscopic data sets (1H, 11B, 13C and 29Si NMR). Copyright © 2008 John Wiley & Sons, Ltd.
Palladium‐catalyzed Heck coupling of 2‐vinylpyridine with aryl chlorides
Authors: Li Ming , Hua Ruimao
Published: May 2008

An efficient PdCl2(PCy3)2‐catalyzed cross‐coupling reaction of 2‐vinylpyridine with aryl chlorides to afford trans‐2‐styrylpyridines with a variety of functional groups on the benzene ring is described. Copyright © 2008 John Wiley & Sons, Ltd.
New biosurfactants based on germylated fatty compounds
Authors: Katir N. , El Kadib A. , Castel A. , Rivière P. , Benmaarouf Z.
Published: May 2008

A simple and efficient method for producing amphiphilic germylated compounds has been developed by hydrogermylation of fatty acid methyl esters. The germylated precursors afford a micelle‐type assembly in various solvents as evident by the formation of nano‐objects, micrometer spheres and lamellar forms. This offers a promising route to synthetically useful monomers for structured materials. Copyright © 2008 John Wiley & Sons, Ltd.
Resin‐IV: Synthesis and characterization of terpolymers derived from 2‐hydroxyacetophenone, melamine, and formaldehyde
Authors: Gupta R. H. , Zade A. B. , Gurnule W. B.
Published: May 2008

Terpolymer resins (2‐HAMF) were prepared by the condensation of 2‐hydroxyacetophenone and melamine with formaldehyde in the presence of acid catalyst and using varied molar ratios of reacting monomers. Compositions of terpolymers have been determined by elemental analysis. The number average molecular weights (Mn) have been determined by conductometric titration in nonaqueous medium. Viscometric measurements in dimethyl sulfoxide have been carried out with a view to ascertain the characteristic functions and constants. Electronic spectra, infrared and nuclear magnetic resonance spectra were studied to elucidate the structure. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Effects of the die geometry on the expansion of polystyrene foams blown with carbon dioxide
Authors: Xu Xiang , Park Chul B.
Published: May 2008

This article presents the effects of the die geometry on the expansion ratio of extruded polystyrene foams blown with CO2. Three groups of interchangeable filamentary dies were used to represent the die parameters. The experimental results reveal that a strong relationship exists between the expansion ratio of the extruded polystyrene foams and the die geometry through its effects on the pressure‐drop rate, the die pressure, the amount of premature cell growth, and the initial shape of the extrudate. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Raman spectroscopy for spinline crystallinity measurements. II. Validation of fundamental fiber‐spinning models
Authors: Patel Rajen M. , Doufas Antonios K. , Paradkar Rajesh P.
Published: May 2008

The original Doufas–McHugh two‐phase microstructural/constitutive model for stress‐induced crystallization is expanded to polyolefin systems and validated for its predictive capability of online Raman crystallinity and spinline tension data for two Dow homopolymer polypropylene resins. The material parameters—inputs to the model—are obtained from laboratory‐scale material characterization data, that is, oscillatory dynamic shear, rheotens (melt extensional rheology), and differential scanning calorimetry data. The same set of two stress‐induced crystallization material/molecular parameters are capable of predicting the crystallinity profiles along the spinline and fiber tension very well overall for a variety of industrial fabrication conditions. The model is capable of predicting the freeze point, which is shown, for the first time, to correlate very well with the measured stick point (i.e., the point in the spinline at which the fiber bundle converts from a solid‐like state to a liquid‐like state and sticks to a solid object such as a glass rod). The model quantitatively captures the effects of the take‐up speed, throughput, and melt flow rate on the crystallization rate of polypropylene due to stress‐induced crystallization effects. This validated modeling approach has been used to guide fiber spinning for rapid product development. The original Doufas–McHugh stress‐induced crystallization model is shown to be numerically robust for the simulation of steady polypropylene melt spinning over a wide range of processing conditions without issues of discontinuities due to the onset of the two‐phase constitutive formulation downstream of the die face, at which crystallization more realistically begins. Because of the capturing of the physics of polypropylene fiber spinning and the very good model predictive power, the approximations of the original Doufas–McHugh model are asserted to be reasonable. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Raman spectroscopy for spinline crystallinity measurements. I. Experimental studies
Authors: Paradkar Rajesh P. , Patel Rajen M. , Knickerbocker Ed , Doufas Antonios
Published: May 2008

Online Raman spectra, obtained at different points along the spinline during the melt spinning of polypropylene homopolymer (hPP) fibers, are presented. The percentage crystallinity corresponding to each spectrum was determined from the normalized intensity of the 809‐cm−1 Raman band. A calibration curve for propylene crystallinity was established offline with compression‐molded films and fibers spun under different processing conditions. Several hPPs and propylene–ethylene copolymers (with 5–15% ethylene) were used to cover a wide calibration range for propylene crystallinity (9.5–60.9%) with an R2 value of 0.989. This calibration curve was subsequently used to predict the polypropylene crystallinity in the spinline as a function of distance from the spinneret. Under identical conditions of quench and throughput, at a fixed point along the spinline, the overall crystallinity developed in the fiber was found to increase with an increase in the spinning speed. As the spinning speed increased, the point of the onset of crystallization moved closer to the spinneret. The rise in crystallinity was more gradual, at 750 m/min as opposed to 1500 m/min. Increasing the throughput at constant spinning speed was found to decrease the rate of crystallization because of a decrease in the spinline stress. At a fixed distance from the spinneret under identical conditions of quench and spinning speed, fibers spun at a higher throughput showed less overall crystallinity. The onset and rate of crystallization was found to be faster in the lower melt index H502‐25RG resin as compared to the 5D49 resin under the spinning conditions explored. The experimental data presented here were used to validate fundamental fiber‐spinning models (see part II of this series of articles). The validated models and experimental observations can be used to guide the fiber spinning of isotactic polypropylene for rapid product development. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis and characterization of rubber‐seed‐oil‐based polyurethanes
Authors: Bakare Isiaka O. , Pavithran C. , Okieimen Felix E. , Pillai C. K. S.
Published: May 2008

Novel biobased polyurethanes were synthesized from rubber seed oil (RSO), a renewable resource. The RSO monoglyceride, together with xylene and hexamethylene diisocyanate (HMDI), was employed to synthesize the desired urethane‐based prepolymer with isocyanate (NCO)‐terminated end groups followed by curing. The degrees of crosslinking of the polyurethane after curing were assessed with their swelling behavior. The properties of the resulting polyurethanes were found to be dependent on the type of diisocyanate and their molar ratios to the RSO monoglyceride. The network structures, which were assessed through swelling studies, showed that networks based on HMDI with an NCO/OH ratio of 1.50 were better crosslinked than with those toluene diisocyanate. The thermal properties of the samples analyzed by thermogravimetric analysis showed two and three decomposition stages in aliphatic‐ and aromatic‐based RSO polyurethanes, respectively. The highest stability with initial decomposition temperature (253°C) and percentage residual at 500°C (11.4%) was achieved with an aliphatic‐based RSO polyurethane. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Radiation‐induced crosslinking and mechanical properties of blends of poly(lactic acid) and poly(butylene terephthalate‐co‐adipate)
Authors: Sarath Kumara P. H. , Nagasawa Naotsugu , Yagi Toshiaki , Tamada Masao
Published: May 2008

Blends of poly(L‐lactic acid) (PLLA) and poly (butylene terephthalate‐co‐adipate) (PBTA) were prepared at ratios of 50 : 50, 60 : 40, and 80 : 20 by melt blending in a Laboplastomill. Improved mechanical properties were observed in PLLA when it was blended with PBTA, a biodegradable flexible polymer. Irradiation of these blends with an electron beam (EB) in the presence of triallyl isocyanurate (TAIC), a polyfunctional monomer, did not cause any significant improvement in the mechanical properties, although the gel fraction increased with the TAIC level and dose level. Irradiation of the blends without TAIC led to a reduction in the elongation at break (Eb) but did not show a significant effect on the tensile strength. Eb of PBTA was unaffected by EB radiation in the absence of TAIC. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis and properties of novel poly(benzimidazopyrrolone amide)s containing pyridine moieties
Authors: Wang Xiaolong , Li Yanfeng , Gong Chenliang , Ma Tao , Zhang Shujiang
Published: May 2008

A series of new poly(benzimidazopyrrolone amide) (PPA) copolymers were synthesized by a two‐step procedure, which was the solution polycondensation of a novel pyridine‐containing tetraamine with various aromatic dianhydrides at a room temperature and cyclization of the resulting prepolymers at a high temperature, respectively. The resulting prepolymers from the solution polycondensation, that is, poly(amide amino acid)s (PAAAs), had inherent viscosities of 0.82–0.91 dL/g; then, tough and flexible PPA films could be successfully prepared by the casting of the PAAA solutions onto a glass substrate followed by thermal curing with a program temperature procedure up to 350°C. The obtained PPA films exhibited not only excellent thermal properties with onset decomposition temperatures in the range 502–521°C, glass‐transition temperatures in the range 299–337°C, and residual weight retentions at 700°C in air of 29.1–34.8% but also good mechanical properties with tensile strengths of 102.1–115.9 MPa and elongations at break of 6.8–7.4%. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis and properties of chitosan‐modified poly(acrylic acid)
Authors: Chuang Chung‐Yang , Don Trong‐Ming , Chiu Wen‐Yen
Published: May 2008

Potassium persulfate (K2S2O8) was used to initiate the polymerization of acrylic acid (AA) monomer in a chitosan (CS) solution. Both a poly(acrylic acid) (PAA) homopolymer and a CS‐co‐PAA copolymer were produced. When the amount of AA was increased from 5 to 40 g with 5 g of CS, the total monomer conversion was found to increase from 89 to 98% after 2 h of reaction at 70°C. In addition, the percentage of reacted AA monomer being converted to the CS‐co‐PAA copolymer (copolymerization efficiency) and the weight composition of the PAA portion in the copolymer (copolymer composition) both increased with the amount of AA added. The structures and properties of the synthesized CS‐modified PAA polymers were studied. In Fourier transform infrared spectra, the formation of a polyelectrolyte complex between CS chains and PAA chains could be observed. From the thermograms obtained via differential scanning calorimetry, we found that the presence of rigid CS chains increased the glass‐transition temperature of PAA. Thermogravimetric analysis revealed three stages of degradation of the synthesized CS‐modified PAA polymers. The swelling ratio of the CS‐modified PAA polymers depended on the pH value and had a maximum value in a buffer solution at pH 7. This was due to the changes in the morphological structure with the pH value. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
High‐frequency welding of thermoplastic LLDPE/PA 6/PE‐g‐MAH ternary blends
Authors: Yoon C. S. , Lee E. M. , Jang M. S. , Song C. K. , Kang C. Y. , Kim K. H. , Kim B. K.
Published: May 2008

High frequency (HF) welding of linear low density polyethylene (LLDPE) melt blends with polyamide 6 (PA6) was done at 27.12 MHz using maleic anhydride grafted polyethylene (PE‐g‐MAH) as compatibilizer. HF welding was not possible for the blends at room temperature, but possible at higher temperatures (50, 80°C) although the maximum relaxation frequency was lower than the operating frequency. Greater dielectric constant, dissipation factor, and welding performance were obtained when PA 6 was premixed with PE‐g‐MAH rather than the one‐shot process where all the components were mixed simultaneously. This was interpreted in terms of lowered viscosity of PA 6 phase, which encapsulates the flow effectively and provides great skin effect. Also, the peeling force of resin–resin was greater than resin–nylon mesh due to the higher melting temperature and vacancy of nylon mesh. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Characterization of polyvinyl alcohol/gelatin blend hydrogel films for biomedical applications
Authors: Pawde S. M. , Deshmukh Kalim
Published: May 2008

In the present investigation, attempt was made to prepare blend hydrogel by esterification of polyvinyl alcohol with gelatin. The blend hydrogel was further converted into films by the conventional solution‐casting method. These films were characterized by FTIR, DSC, and X‐ray diffraction studies. The refractive index and viscosity of different composition of the blends were measured in the solution phase of the material. The mechanical properties of the blend films were measured by tensile test. Swelling behavior of the blend hydrogel was also studied. The FTIR spectrum of the blend film indicated complete esterification of the free carboxylic group of gelatin. The DSC results indicate that the addition of gelatin with PVA changes the thermal behavior like melting temperature of PVA, which may be due to the miscibility of PVA with gelatin. The interaction of gelatin with PVA molecule changes the crystallite parameters and the degree of crystallinity. The crystallinity of the blend film was mainly due to gelatin. The comparison of viscosity indicated an increase in the segment density within the molecular coil. The results revealed the changes observed in the properties of the gel, and it enhances the gel formation at viscoelastic phase of the material. The blend film had sufficient strength and water‐holding capacity. The results obtained indicated that the blend film could be used for various biomedical applications such as wound dressing and drug‐delivery systems. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Effect of silicone oil on the morphology and properties of polycarbonate
Authors: Kim Sung‐Ryong , Kim Dong‐Ju
Published: May 2008

Two types of silicone oil, poly(dimethyldiphenyl siloxane) (PDMDPS) and poly(dimethyl siloxane) (PDMS), were added to polycarbonate (PC), and the morphological, mechanical, rheological, and thermal changes of the PC/silicone oil were investigated. A scanning electron microscope showed that the dispersed droplets of the silicone oils in the PC matrix and the size of the dispersed phases were enlarged with increasing amounts of silicone oil. A transition from brittle to ductile failure was observed with increasing PDMDPS. The impact strength of neat PC at −30°C was 8 kgf cm/cm, which increased to 52 kgf cm/cm with the addition of PDMDPS. It appears that, at low temperature, the phenyl group in PDMDPS is more effective for toughening. A higher decomposition temperature and the bulkier molecular structure of PDMDPS, compared to PDMS, resulted in a smaller increase in the melt flow index of PC/PDMDPS than for PC/PDMS. The glass transition temperature, initiation temperature of thermal weight loss, and heat distortion temperature of PC/silicone oil systems were decreased with an increase in the silicone oil. The blending of PC with PDMDPS provided a practical way to develop a combination of high tensile strength and impact strength at a low temperature with applicable comprehensive properties. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
English‐Arabic proper‐noun transliteration‐pairs creation
Authors: Fattah Mohamed Abdel , Ren Fuji
Published: May 2008

Proper nouns may be considered the most important query words in information retrieval. If the two languages use the same alphabet, the same proper nouns can be found in either language. However, if the two languages use different alphabets, the names must be transliterated. Short vowels are not usually marked on Arabic words in almost all Arabic documents (except very important documents like the Muslim and Christian holy books). Moreover, most Arabic words have a syllable consisting of a consonant‐vowel combination (CV), which means that most Arabic words contain a short or long vowel between two successive consonant letters. That makes it difficult to create English‐Arabic transliteration pairs, since some English letters may not be matched with any romanized Arabic letter. In the present study, we present different approaches for extraction of transliteration proper‐noun pairs from parallel corpora based on different similarity measures between the English and romanized Arabic proper nouns under consideration. The strength of our new system is that it works well for low‐frequency proper noun pairs. We evaluate the new approaches presented using two different English‐Arabic parallel corpora. Most of our results outperform previously published results in terms of precision, recall, and F‐Measure.
Organic‐Inorganic Hybrid Materials for Efficient Enantioseparation Using Cellulose 3,5‐Dimethylphenylcarbamate and Tetraethyl Orthosilicate
Authors: Ikai Tomoyuki , Yamamoto Chiyo , Kamigaito Masami , Okamoto Yoshio
Published: May 2008

The hybrid bead‐type chiral packing material (CPM) for preparative enantioseparation has been prepared from the cellulose 3,5‐dimethylphenylcarbamate containing a small number of 3‐(triethoxysilyl)propyl groups in the presence of tetraethyl orthosilicate, by a sol‐gel reaction in an aqueous surfactant solution. The obtained hybrid bead‐type CPM was packed into a column and evaluated by high‐performance liquid chromatography. When compared with the commercially available Chiralpak IB, which is prepared by the immobilization of cellulose 3,5‐dimethylphenylcarbamate on silica gel, the hybrid bead‐type CPM was shown to exhibit a similar chiral recognition and possess a higher loading capacity.
NMR Studies on Monofunctionalized Fullerenyl Cation and Anion Encapsulating a H2 Molecule
Authors: Murata Michihisa , Ochi Yuta , Kitagawa Toshikazu , Komatsu Koichi , Murata Yasujiro
Published: May 2008

1H NMR chemical shifts of molecular hydrogen encapsulated in dichloromethyl–C60 cation and (1‐octynyl)–C60 anion were studied to clarify the difference in magnetic shielding effects inside the fullerene cages. The signals of the H2 molecule inside both cationic and anionic C60 cages appeared at lower fields than those of the neutral counterparts. These results were interpreted based on the results of NICS calculations. It was demonstrated that the H2 molecule inside the C60 cages can serve as an excellent NMR probe of aromaticity for both cationic and anionic C60 derivatives.