bluuebunny/crossref_metadata_2025_split huggingface dataset:
Assessment of Alcohol Use Control Programs in Secondary Schools in Lofa County, Liberia
Authors: Korvah Macklin Marvin 
Published: April 2024

Introduction: As one of the leading risk factors for disease burdens in the modern era, alcohol consumption exacerbates health-related repercussions with likely threatening influences on morbidity and mortality. Alcohol use in Liberia is a relic that hems in the anthropological and sociological perspectives on the economy, culture, and society. Students drinking has plagued several learning institutions across the country. Hence, some private and public institutions established school-based alcohol use control programs to help reduce in-school-youths' drinking. However, no study has credibly investigated the disparity in the prevalence of drinking between public and private school students. This study aimed to examine and compare the alcohol use prevalence between public and private secondary school students in Liberia.
Methods: A quantitative method using a self-administered questionnaire to explore and interpret the prevalence of alcohol use between two independent populations, public (220) and private (180) secondary school students, was adopted. The study was done in Lofa County among students under age 14 to age 29 years. MS Excel 2016 (Office 365) was used for a two-proportion z-test analysis between two population proportions of alcohol users (public and private school students), while IBM 21.0 SPSS was used to perform chi-square tests of independence to test the association between categorical variables.
Results: Drinking was a common phenomenon among students; however, the prevalence was significantly higher in public schools (71.8%) compared to private schools (32.8%). In a chi-square (X2) test for independence in an eventuality table, there is a non-significant association between alcohol use and "age group (p=0.406)," "gender (p=0.073)," and "grade levels (p=0.073) in public schools. However, in private schools, there is a significant association between alcohol use and "age group (p=0.000)," "gender (p=0.000)," and "grade levels (p=0.000).
Conclusions: Several factors, as well as sociodemographic characteristics, limited knowledge of alcohol use policy, and students' proximity to family members who are distillers and vintners, especially in public schools, influence the high rate of alcohol use among students. Therefore, a comprehensive intervention strategy that encompasses students' social environment, including the community, school, and family, is needed to reduce and prevent students' drinking in Liberia.
Elementary Steps of Gold Catalysis: NMR Spectroscopy Reveals the Highly Cationic Character of a “Gold Carbenoid”
Authors: Seidel Günter , Mynott Richard , Fürstner Alois 
Published: February 2009

AbstractWas bist Du? Die metallinduzierte Ringöffnung 3,3‐disubstituierter Cyclopropene liefert bekanntlich Carbene; doch bei der Verwendung von AuI in dieser Reaktion erhält man ein reaktives Intermediat mit deutlich kationischem Charakter. Diese Beobachtung hat große Konsequenzen für die Goldkatalyse im Allgemeinen, bei der man bisher eine Beteiligung von Goldcarbenen angenommen hat.magnified image
Catalytic Cycloisomerization of 1,5‐Enynes to 1,3‐Cyclohexadienes via Ruthenium Vinylidene Intermediates
Authors: Fukamizu Koji , Miyake Yoshihiro , Nishibayashi Yoshiaki 
Published: February 2009

AbstractAlternativer Weg zu Dienen: Die rutheniumkatalysierte 6‐endo‐Cycloisomerisierung von 1,5‐Eninen ergibt die entsprechenden 1,3‐Cyclohexadiene in guten bis sehr guten Ausbeuten. Dieses neuartige Verfahren ist eine Alternative für die selektive Synthese von 1,3‐Cyclohexadienen, die Bausteine zahlreicher Naturstoffe sind und als vielseitige Zwischenstufen in der organischen Synthese dienen.magnified image
Ruthenium Nanoparticles Supported on Carbon Nanotubes as Efficient Catalysts for Selective Conversion of Synthesis Gas to Diesel Fuel
Authors: Kang Jincan , Zhang Shuli , Zhang Qinghong , Wang Ye 
Published: February 2009

AbstractDiesel do nicely: The title system is a highly selective Fischer–Tropsch catalyst for the production of C10–C20 hydrocarbons (diesel fuel). The C10–C20 selectivity strongly depends on the mean size of the Ru nanoparticles. Nanoparticles with a mean size around 7 nm exhibit the highest C10–C20 selectivity (ca. 65 %) and a relatively higher turnover frequency for CO conversion.magnified image
The Complexed Triphosphaallyl Radical, Cation, and Anion Family
Authors: Scheer Manfred , Kuntz Christian , Stubenhofer Markus , Linseis Michael , Winter Rainer F. , Sierka Marek 
Published: February 2009

AbstractRadically complex: The photolytic reaction of [Cp*P{W(CO)5}2] (Cp*=C5Me5) with a diphosphene produces, via a radical intermediate, an air‐stable complexed triphosphaallyl radical, in which the unpaired electron is evenly distributed over both terminal P atoms. Oxidation of the radical leads to a triphosphaallyl cation, which is only stable at low temperatures in solution, whereas the stable triphosphaallyl anion is formed by reduction (see picture, Mes*=2,4,6‐tri‐tert‐butylphenyl).magnified image
Zinc Oxide Nano‐ and Microfabrication from Coordination‐Polymer Templates
Authors: Liu Xiaogang 
Published: February 2009

AbstractHex nut: An emerging synthetic approach based on metal–organic coordination‐polymer templates has been used to fabricate micro‐ and nanoscale crystals. By using a diverse range of molecular building blocks coupled with conventional synthetic techniques, it is possible to synthesize ZnO crystals with tailored sizes, shapes (such as hexagonal rings; see figure), and surface properties.magnified image
Novel peroxide‐vulcanized NBR‐PAni.DBSA blends, part 1: Preparation and characterization
Authors: Yong K. C. , Saad Che Su Mt 
Published: February 2009

AbstractBlends of poly(butadiene‐co‐acrylonitrile)‐polyaniline dodecylbenzenesulfonate [NBR‐PAni.DBSA] were successfully prepared using an internal mixer for the first time. Electrical conductivities of all the vulcanized blends (up to 10−2 S/cm with a conductivity percolation threshold 6.0 wt %/5.4 vol % of PAni.DBSA) were not affected with the addition of dicumyl peroxide (DCP) as the vulcanizing agent. The FTIR spectra of vulcanized NBR‐PAni.DBSA blends resembled a superposition of the spectra of the raw materials, but with some notable peak shifts because of the changing intermolecular interactions between the polymers. Blends with ≤30 wt % of PAni.DBSA showed the best compatibility, i.e., with greatest peak shifts for their FTIR spectra and largest temperature shifts for their DSC recorded thermal events. The morphological studies (of both optical and transmission electron micrographs) showed that the thermomechanical mixing method had reduced the amounts of phase separation in all these NBR‐PAni.DBSA blends. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis and characterization of poly(ether ketone ether ketone ketone)/poly(ether ether ketone ketone) copolymers containing naphthalene and pendant cyano groups
Authors: Cai Mingzhong , Zhu Meihua , Yu Yikai 
Published: February 2009

Abstract2,6‐Bis(β‐naphthoxy)benzonitrile (BNOBN) was synthesized by reaction of β‐naphthol with 2,6‐difluorobenzonitrile in N‐methyl‐2‐pyrrolidone (NMP) in the presence of KOH and K2CO3. Poly(ether ketone ether ketone ketone)(PEKEKK) /poly(ether ether ketone ketone) (PEEKK) copolymers containing naphthalene and pendant cyano groups were obtained by electrophilic Friedel‐Crafts polycondensation of terephthaloyl chloride (TPC) with varying mole proportions of 4,4′‐diphenoxybenzophenone (DPOBP) and 2,6‐bis(β‐naphthoxy)benzonitrile (BNOBN) using 1,2‐dichloroethane (DCE) as solvent and NMP as Lewis base in the presence of anhydrous AlCl3. The resulting polymers were characterized by various analytical techniques, such as FTIR, DSC, TG, and WAXD. The results indicated that the crystallinity and melting temperature of the polymers decreased with increase in concentration of the BNOBN units in the polymer, the glass transition temperature of the polymers increased with increase in concentration of the BNOBN units in the polymer. Thermogravimetric studies showed that all the polymers were stable up to 536°C in N2 atmosphere. The copolymers have good resistance to acidity, alkali, and organic solvents. Because of the melting temperature (Tm) depression with increase in the BNOBN content in the reaction system, the processability of the resultant coplymers could be effectively improved. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Crosslink density and diffusion mechanisms in blend vulcanizates loaded with carbon black and paraffin wax
Authors: Abu‐Abdeen M. , Alkhateeb A. 
Published: February 2009

AbstractResults on blends containing different ingredients have revived the interest on the interaction parameter and crosslink density of structures that contain soft fillers. Composite blend of natural rubber and styrene butadiene rubber loaded with the percolation concentration of high abrasion furnace carbon black and different concentrations with paraffin wax were prepared. The applicability of the blends for liquid diffusion has been examined through the changes in the interaction parameter and the crosslink density at different temperatures. The transport mechanism through the vulcanized blends is governed by Fickian diffusion law at room temperatures and it becomes non‐Fickian at higher temperatures. The diffusion coefficients were calculated and found to have an activated behavior with temperature from which the activation energy was calculated. The change in entropy, enthalpy, and Gibbs free energy are also studied at different temperatures. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Model prediction of the ESCR of semicrystalline polyethylene: Effects of melt cooling rate
Authors: Sharif A. , Mohammadi N. , Ghaffarian S. R. 
Published: February 2009

AbstractThe effects of melt cooling rate on the morphology and environmental stress cracking resistance (ESCR) of a commercial‐grade high‐density polyethylene (HDPE) were investigated by DSC, WAXS, Raman spectroscopy, DMTA, microhardness, and standard Bell test. The results showed exclusion of short chain branches from the crystallites leading to their perfection by decrease in the melt cooling rate. Accordingly, samples' ESCR increased because of the aforementioned crystal thickening. In addition, quantitative evaluation of crystal strength was performed for the first time by microhardness technique. Crystal strength or the required energy for plastic deformation of unit area of the crystals, Δh·ℓc, complemented crystal thickening hypothesis. The product of Δh and average crystal thickness, ℓc, was also proportional with storage modulus of the samples at ESCR test temperature. The evaluation of the results using the recently proposed model based on the analogy of crack growth through amorphous phase of semicrystalline polymers in harsh environments with crack growth at adhesive polymer–substrate interfaces showed reasonably good correlation. Finally, the comparison of literature and current research data based on the new model delineated new directions for phenomenon generalization. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Expression and Identification of Immunological Activities of the HIV‐gp120N‐Human Interferon Gamma Fusion Protein
Authors: Feng Ting‐Ting , Zhao Gang , Yao Hang Ping , Wang Qiao Ping , Wu Nan‐Ping 
Published: February 2009

AbstractThe human immunodeficiency virus type 1 (HIV‐1) envelope glycoprotein gp120 is a vaccine immunogen that has been studied extensively. To enhance the immune response of cells against HIV‐1 gp120, we tested the coexpression of gp120N with interferon‐γ (IFN‐γ) as an immune adjuvant. Two recombinant prokaryotic plasmids were constructed: the pET44b‐HIV‐1‐gp120N plasmid construct carried the HIV‐1 gp120N gene (pET44‐gp120N), whereas the pET44b‐HIV‐1‐gp120N‐IFN‐γ plasmid construct carried a fusion gp120N‐IFN‐γ gene (pET44b‐gp120N‐IFN‐γ). Target protein expression was achieved in E. coli BL21 (DE3) cells by chemical induction. To test the immunological activity of the proteins, mice were injected with a control, gp120N, or the fusion gp120N‐IFN‐γ protein. The serum and spleen cells of the mice were collected for immunological detection. Results showed that specific T lymphocyte proliferation and the expression of the Th1‐type cytokines (IL‐2 and IFN‐γ) were higher in the gp120N‐IFN‐γ group than the other two groups (P < 0.05). No difference was observed in the expression levels of the Th2‐type cytokines (IL‐4 and IL‐10; P > 0.05). These results suggest that IFN‐γ plays a prominent role as an immune adjuvant when coexpressed with HIV‐1 gp120N. IFN‐γ enhances the specific cell immune response of mice against HIV‐1 gp120. Anat Rec, 292:381–386, 2009. © 2009 Wiley‐Liss, Inc.
The Lateral Line System in Larvae of the Blind Cyprinid Cavefish, Phreatichthys andruzzii
Authors: Dezfuli Bahram S. , Capuano Silvia , Magosso Sara , Giari Luisa , Berti Roberto 
Published: February 2009

AbstractScanning and transmission electron microscopic observations were made on the anterior and posterior lateral line system of larvae of the blind cavefish, Phreatichthys andruzzii. The investigations were conducted on 36 specimens belonging to three different ages of juvenile: 7, 14, and 28 days posthatching. The basic sensory unit of the mechanoreceptive system is a superficial “neuromast,” which is composed of sensory hair cells (HCs) embedded in nonsensory support cells (SCs) frequently covered with a cupula. Head neuromasts had the longest cupulae. These organs presented the same structure and ultrastructure in the head and along the body of all specimens of P. andruzzii of different ages. Hair cells of neuromasts of P. andruzzii larvae were pear‐shaped cells ∼10–20 μm high and 3–5 μm in diameter. The nucleus of each hair cell was large and basally placed, the cytoplasm contained numerous mitochondria and each HC had a single long kinocilium and several short stereocilia. The majority of SCs were elongated in shape and their nuclei occupied a significant portion of the cytoplasm. The support cells at the margin of the neuromast were particularly thin. Both types of support cells possessed well‐developed rough endoplasmic reticulum and Golgi apparatus. The size and number of neuromasts and their component cells increased with the age of larvae (ANOVA, P < 0.05). The dimensions of the neuromasts of the anterior lateral line (head) did not differ significantly from those of the posterior lateral line (trunk) (ANOVA, P > 0.05). Anat Rec, 292:423–430, 2009. © 2009 Wiley‐Liss, Inc.
Cardiac Stem Cell Research: An Elephant in the Room?
Authors: Di Felice Valentina , De Luca Angela , Colorito Maria Luisa , Montalbano Antonella , Ardizzone Nella Maria , Macaluso Filippo , Gammazza Antonella Marino , Cappello Francesco , Zummo Giovanni 
Published: February 2009

AbstractHeart disease is the leading cause of death in the industrialized world, and stem cell therapy seems to be a promising treatment for injured cardiac tissue. To reach this goal, the scientific community needs to find a good source of stem cells that can be used to obtain new myocardium in a very period range of time. Since there are many ethical and technical problems with using embryonic stem cells as a source of cells with cardiogenic potential, many laboratories have attempted to isolate potential cardiac stem cells from several tissues. The best candidates seem to be cardiac “progenitor” and/or “stem” cells, which can be isolated from subendocardial biopsies from the same patient or from embryonic and/or fetal myocardium. Regardless of the technique used to isolate and characterize these cells, it appears that the different cells isolated from adult myocardium to date are all phenotypic variations of a unique cell type that expresses several markers, such as c‐Kit, CD34, MDR‐1, Sca‐1, CD45, nestin, or Isl‐1, in various combinations. Anat Rec, 292:449–454, 2009. © 2009 Wiley‐Liss, Inc.
Morphological Changes in the Mandible of Male Mice Associated With Aging and Biomechanical Stimulus
Authors: Tagliaro Maria Luisa , De Oliveira Raquel Mattos , Padilha Dalva Maria Pereira , Callegari‐Jacques Sidia Maria , Jeckel‐Neto Emílio Antônio 
Published: February 2009

AbstractDegenerative changes in the temporomandibular joint (TMJ) associated with aging can affect mandibular shape and reduce growth potential when stimulated by functional appliance therapy. This study was designed to evaluate the morphological changes in the mandibles of male mice associated with aging and biomechanical stimulus. Every 3 days over the course of 1 month, the lower incisors were trimmed by 1 mm to induce mandibular advancement (MA) when the animal was feeding. The left mandibles of the 23 experimental and 27 control animals were subsequently dissected, and digital images were obtained to analyze nine linear/angular measurements. Because mandibular morphology depends on the maintenance of condylar cartilage, the surfaces of the condylar cartilage and the ascending ramus of the mandible were also analyzed by scanning electron microscopy (SEM). The linear measurements of the mandible showed changes according to age in the control group and a growth response in the mandibular condyle in 7‐ and 15‐month‐old mice after MA. Moreover, SEM analysis revealed depressions in the anterior region of the condylar cartilage and inclined vascular grooves in the ascending ramus in the 7‐ and 15‐month‐old experimental mice. Although the growth potential is reduced in mice after 6 months of age, the results showed that continuous growth of the mandible occurs after maturation, except in the condyle, and that biomechanical stimulus of the TMJ of male mice leads to condylar growth. These results suggest that mature and old individuals can favorably respond to maxillary functional orthopedic therapy. Anat Rec, 292:431–438, 2009. © 2009 Wiley‐Liss, Inc.
VESGEN 2D: Automated, User‐Interactive Software for Quantification and Mapping of Angiogenic and Lymphangiogenic Trees and Networks
Authors: Vickerman Mary B. , Keith Patricia A. , McKay Terri L. , Gedeon Dan J. , Watanabe Michiko , Montano Monica , Karunamuni Ganga , Kaiser Peter K. , Sears Jonathan E. , Ebrahem Quteba , Ribita Daniela , Hylton Alan G. , Parsons‐Wingerter Patricia 
Published: February 2009

AbstractQuantification of microvascular remodeling as a meaningful discovery tool requires mapping and measurement of site‐specific changes within vascular trees and networks. Vessel density and other critical vascular parameters are often modulated by molecular regulators as determined by local vascular architecture. For example, enlargement of vessel diameter by vascular endothelial growth factor (VEGF) is restricted to specific generations of vessel branching (Parsons‐Wingerter et al., Microvascular Research72: 91, 2006). The averaging of vessel diameter over many successively smaller generations is therefore not particularly useful. The newly automated, user‐interactive software VESsel GENeration Analysis (VESGEN) quantifies major vessel parameters within two‐dimensional (2D) vascular trees, networks, and tree‐network composites. This report reviews application of VESGEN 2D to angiogenic and lymphangiogenic tissues that includes the human and murine retina, embryonic coronary vessels, and avian chorioallantoic membrane. Software output includes colorized image maps with quantification of local vessel diameter, fractal dimension, tortuosity, and avascular spacing. The density of parameters such as vessel area, length, number, and branch point are quantified according to site‐specific generational branching within vascular trees. The sole user input requirement is a binary (black/white) vascular image. Future applications of VESGEN will include analysis of 3D vascular architecture and bioinformatic dimensions such as blood flow and receptor localization. Branching analysis by VESGEN has demonstrated that numerous regulators including VEGF165, basic fibroblast growth factor, transforming growth factor β‐1, angiostatin and the clinical steroid triamcinolone acetonide induce ‘fingerprint’ or ‘signature’ changes in vascular patterning that provide unique readouts of dominant molecular signaling. Anat Rec, 292:320–332, 2009. © 2009 Wiley‐Liss, Inc.
Differential MMP‐2 and MMP‐9 Activity and Collagen Distribution in Skeletal Muscle from pacu(Piaractus mesopotamicus)During Juvenile and Adult Growth Phases
Authors: Michelin Aline Cristina , Justulin Luis Antonio , Delella Flávia Karina , Padovani Carlos Roberto , Felisbino Sérgio Luis , Dal‐Pai‐Silva Maeli 
Published: February 2009

AbstractHere, we evaluated collagen distribution and matrix metalloproteinases (MMPs) MMP‐2 and MMP‐9 activities in skeletal muscle of pacu (Piaractus mesopotamicus) during juvenile and adult growth phases. Muscle samples from juvenile and adult fishes were processed by histochemistry for collagen system fibers and for gelatin‐zymography for MMP‐2 and MMP‐9 activities analysis. Picrosirius staining revealed a myosept, endomysium, and perimysium‐like structures in both growth phases and muscle types, with increased areas of collagen fibers in adults, mainly in red muscle. Reticulin staining showed that reticular fibers in the endomysium‐like structure were thinner and discontinuous in the red muscle fibers. The zymography revealed clear bands of the pro‐ MMP‐9, active‐ MMP‐9, intermediate‐ MMP‐2, and active‐ MMP‐2 forms in red and white muscle in both growth phases. MMP‐2 activity was more intense in juvenile than adult muscle fibers. Comparing the red and white muscle types, MMP‐2 activity was significantly higher in red muscle in adult phase only. The activity of MMP‐9 forms was similar in juvenile red and white muscles and in the adult red muscle, without any activity in adult white muscle. In conclusion, our results show that,in pacu, the higher activities of MMP‐2 and ‐9 are associated with the rapid muscle growth in juvenile age and in adult fish, these activities are related with a different red and white muscle physiology. This study may contribute to the understanding muscle growth mechanisms and may also contribute to analyse red and the white muscle parameters of firmness and softness, respectively, of the commercial product. Anat Rec, 292:387–395, 2009. © 2009 Wiley‐Liss, Inc.