bluuebunny/crossref_metadata_2025 huggingface dataset:
Entrepreneurship Education: Panacea for Unemployment and Poverty among Business Education Graduates in South-South, Nigeria
Authors: Okoro E. P.
Published: May 2024

This study investigated Entrepreneurship Education as Panacea for unemployment and poverty among Business Education graduates in South-South, Nigeria. It adopted the descriptive survey design, two research questions and two hypotheses guided the study. The target population which served as sample comprised 217 Business Education Lecturers in universities south-south, Nigeria. A questionnaire was the instrument used for data collection. The questionnaire had two parts: part A contained 4 items of demographic variables of respondents – name of university, sex, university type (Federal or State), mode of entry. Part B contained 10 items based on the two research questions: Research Question One contained 5 items and Research Question Two contained 5 items. The questionnaire was structured on a 4 – point scale of responses: Very High Extent 4 – points, High Extent 3 – points, Low Extent 2 – points, Very Low Extent 1 – point. There was face and content validity of the instrument. The instrument was validated by experts in Business Education and Measurement and Evaluation at the Delta State University, Abraka. The reliability of the instrument was ascertained through Cronbach Alpha and the results of the two research questions are – r = 0.87 and r = 0.88 respectively. A total of 217 copies of the questionnaire were administered to 217 Business Education Lecturers in all the universities offering Business Education Programmes in South- south, Nigeria. 202 copies were fully completed and returned indicating a return rate of 93.09 %. The Data collected were analyzed using mean and standard deviations. The findings showed the respondents affirming to a high extent that Entrepreneurship Education can help in eradicating unemployment and poverty by sustaining Entrepreneurship and creating wealth. It was therefore recommended among others that Entrepreneurship Education should be integrated in the education curriculum and government should establish Enterprise Development centres to promote Entrepreneurship Education.
A Review on Precision Agriculture Navigating the Future of Farming with AI and IoT
Authors: M E Krishnababu , Devi B. Rama , Soni Amitabh , Panigrahi Chandan Kumar , Sudeepthi B. , Rathi Abhinav , Shukla Anoop
Published: May 2024

Precision agriculture (PA) integrates advanced technologies such as Artificial Intelligence (AI) and the Internet of Things (IoT) to enhance the efficiency, productivity, and sustainability of agricultural practices. In India, the adoption of these technologies is emerging as a transformative force aimed at overcoming longstanding challenges such as resource depletion, yield variability, and environmental degradation. This review paper discusses the evolution and current state of PA in India, emphasizing the role of AI and IoT in revolutionizing farming practices. AI enhances decision-making through predictive analytics and machine learning models, enabling precise crop and soil monitoring, disease detection, and yield prediction. IoT complements these capabilities by providing essential infrastructure for data collection and real-time monitoring, facilitating smarter resource management and operational efficiency. The paper identifies key technical, economic, and social challenges hindering the widespread adoption of PA technologies in India, including high initial costs, scalability issues, data privacy concerns, and the impact on traditional farming employment. Solutions such as government subsidies, tailored technology adaptation, and comprehensive farmer training programs are discussed as means to address these challenges. The paper concludes by highlighting the importance of multi-stakeholder collaboration in fostering an environment conducive to the growth of precision agriculture in India. Through a combination of policy support, technological innovation, and strategic partnerships, India can fully leverage PA to meet its agricultural goals of sustainability and high productivity.
Studies on Nutrient Use Efficiency in Short Duration Red Gram (Cajanus cajan (l.) Millsp.) Varieties under Site-Specific Nutrient Management Techniques
Authors: V Arun Kumar , K Sharmili , K Udhaya Kumar , R Isaac Manuel , B Balaganesh
Published: May 2024

Aim: To evaluate the nutrient use efficiency of short duration red gram varieties under site-specific nutrient management.
Place and Duration of Study: The experiment was carried out in the rabi season of 2023 at an experimental farm in Karunya Institute of Technology and Sciences, Coimbatore. Experimental field was silty clay loam in texture with medium in available N (295 kg/ha), high in available P2O5 (kg /ha) and high in available K2O (285 kg/ha).
Study Design: Split plot design.
Methodology: The treatments consisted of three varieties in main plot namely V1- APK 1, V2- VBN 3, V3- VBN 1 and eight treatment in sub plots T1- (+NPK), T2 - N (-PK), T3 - P (-NK), T4 - K (-NP), T5 - PK (-N), T6 - NK (-P), T7 - NP (-K), and T8 - Control (-NPK).
Result: Applying fertilizer as per recommended dose of nutrients without nutrient omission, resulted in increased nutrient use efficiency, agronomic efficiency, partial factor productivity and partial nutrient budget.
Effectiveness of Soil-amended Biochar in Improving Crop Production, Soil Health and Environmental Aspects
Authors: Kaur Harpreet , Dilshad Prince, , Kaushal Shilpa , Shubham .
Published: May 2024

Sustainable agriculture has assumed greater importance in today’s world. Biochar has the potential to increase crop yield and soil fertility in agriculture while reducing greenhouse gas emissions at the same time. Biochar production technology and biomass type has great influence on its quality and yield which in turn is responsible for altering soil fertility status and enhancing other soil properties. Biochar is produced via thermochemical conversion of biomasses by the process of pyrolysis with different pyrolysis conditions which include heating rate, temperature or residence time that affect the product distribution and yield for biochar produced from same biomass. Biochar is produced sustainably from eco-friendly sources under manageable conditions such as agricultural woody and non-woody wastes or crop residues or animal wastes. Biochar’s acknowledgement in removing heavy toxic metals, organic solvents and pesticide residues from soil as well as in waste water management aids in environmental protection. Yield response of biochar produced from various feedstock sources on vegetable crop production is discussed to compare their relative effectiveness. Biochar is a carbonaceous substance produced that sequester carbon and remain in soil for thousands of years and thus offers stability in soil. Biochar as Negative Emissions Technology (NET) in removing CO2 from atmosphere and other greenhouse gases such as N2O and CH4 is a prominent methodology in mitigating serious concern of climate change. The objective of this review paper is to extensively justify the role and importance of biochar in agriculture and sustainable growth.
Isolation and Characterization of Glucocorticoid Steriod from the Leaf of Rauvolfia vomitoria
Authors: Uyanwa Maryjane N.  , Igwe Okenwa Uchenna , Irenus Iwu , Linda Nwoke , Echeme Johnbull O.
Published: May 2024

Isolation and characterization of glucocorticoid steroid was carried out on the leaf of Rauvolfia vomitoria. Initial phytochemical screening of the sample revealed the presence of saponins, flavonoids, alkaloids, tannins, steroids, triterpenoids and cardiac glycoside and were quantitatively determined as follows; saponins (2.37 ± 1.09), tannins (0.09 ± 0.01), alkaloids (0.82 ± 1.05), and flavonoids (0.82 ± 0.05). Isolation of the compound was carried out with the aid of column chromatography and isolate subjected to thin layer chromatography. Sample was subjected to spectroscopic analysis with the aid of FT-IR, 1H NMR, 13C NMR and HSQC. The structure of compound was determined as Cis-3-(2,2-dimethyl-26-(((2S,3R,4S,5R,6R)-2,3,4-trihydroxy-5-(hydroxymethyl)tetrahydro-2H-pyran-2-yl)oxy)butan-2-yl)-8-methoxy-15-(S)-3-methoxy-4,4- dimethylpentyl)-14-(3-methoxy-4,4-dimethylpent-1-yn-1-yl)-1,2,3,4,11,12,13,14,15,15a- octahydrophenanthro [2,1-b]furan-16(10H)-one with a molecular formulae of C44H68O11. A glucocorticoid steroid.
Water Chestnut (Trapa natans) a Crop of High Nutritional and Economical Importance-Recent Guidelines on Farming Practices
Authors: Singh I.S. , Tarate S.B. , Thakur A.K.
Published: May 2024

The global food problem could be resolved to some extent by the production of Water chestnuts. Moreover, waterlogging developed due to global warming would be better utilized by the cultivation of Water chestnut. The cultivation of thornless Water chestnuts alone or along with fish takes place in water bodies or ponds with depths ranging from 1.20 to 1.80 m as well as in shallow agricultural fields with depths of 0.30 to 0.45 m. The major carp fish could be successfully incorporated in the Water chestnut growing ponds. The water chestnut prefers to be grown in organic matter rich ponds or shallow lands. It has been found that T. natans is very efficient in absorbing nutrients, particularly N, P, K, Cu and Zn. The fruit of the Water chestnut has considerable nutritional and economical significance. The entire herb and fruit of the Water chestnut have been acknowledged in traditional medicine for their medicinal properties, serving as remedies for various diseases.
Improvement in work place and household productivity for patients with early rheumatoid arthritis treated with adalimumab plus methotrexate: Work outcomes and their correlations with clinical and radiographic measures from a randomized controlled trial companion study
Authors: van Vollenhoven Ronald F. , Cifaldi Mary A. , Ray Saurabh , Chen Naijun , Weisman Michael H.
Published: January 2010

Objective

To evaluate household and work place outcomes for patients with rheumatoid arthritis (RA) who were homemakers or employed workers, respectively, and who were treated with adalimumab plus methotrexate versus methotrexate monotherapy. We also determined baseline predictors of household and work place outcomes.

Methods

Data were from a health economic companion study to PREMIER, a 2‐year, randomized controlled trial of methotrexate‐naive patients with early RA (<3 years) who received treatment with adalimumab plus methotrexate, adalimumab, or methotrexate. Absenteeism (number of days missed or unfit to work), presenteeism (self‐judgment of the effects of RA on job or household performance), and employment status were collected from self‐reports at baseline and varying time points during the study.

Results

Household and work place outcomes were generally similar for homemakers and employed workers. Over 2 years, patients who received combination therapy missed approximately half as many days as patients who received methotrexate (17.4 versus 36.9 days for employed workers; 7.9 versus 18.6 days for homemakers). Presenteeism was lower (reflecting better productivity) for combination therapy than methotrexate monotherapy. The likelihood of gaining/retaining employment over 2 years was greater for combination therapy than methotrexate monotherapy (odds ratio 1.530, 95% confidence interval 1.038–2.255; P = 0.0318). Baseline radiographic progression was an independent predictor for retaining/gaining employment at 2 years.

Conclusion

Compared with methotrexate monotherapy, combination therapy was associated with more positive work outcomes: less absenteeism, less presenteeism, and greater likelihood of gaining/retaining employment. Radiographic progression at baseline was predictive of the ability to retain or gain employment.
Association between computer use speed and age, impairments in function, and touch typing training in people with rheumatoid arthritis
Authors: Baker Nancy A. , Rogers Joan C.
Published: January 2010

Objective

To explore the associations between impairments in hand function associated with rheumatoid arthritis (RA) and limitations in computer peripheral use.

Methods

A total of 45 computer users with RA were recruited from the Arthritis Network Research Registry. Impairments in hand function were measured using the Keitel Hand Function Index, and the Arthritis Hand Function Test, while general activity limitations were measured with the Health Assessment Questionnaire. Speed of computer peripheral device use was obtained at a laboratory work station using the Assessment of Computer Task Performance (ACTP).

Results

Multiple regression models suggested that keyboarding speed was significantly associated with touch typing training and age, while mouse speed was significantly associated with age. Impairments in hand function were significantly associated with only 2 of 7 keyboarding tasks and no mouse tasks. General activity limitations were associated with 2 of 7 keyboarding tasks and 2 of 5 significant mouse tasks. A comparison of this study's sample with a normative sample reported for the ACTP suggested that this sample's keyboarding speed was similar to a nonimpaired sample, while mouse speed was much slower.

Conclusion

Reduced keyboarding speed is most strongly associated with touch typing skill. General activity limitations appear to be the strongest arthritis‐related predictor of decreased computer use speeds. Many computer users with RA will not experience reduced productivity in typing speeds, although many may be slower than their nonimpaired counterparts for mouse use.
Diagnostic delay in sternocostoclavicular hyperostosis: Impact on various aspects of quality of life
Authors: van der Kloot Willem A. , Chotkan Sadhna A. , Kaptein Ad A. , Hamdy Neveen A. T.
Published: January 2010

Objective

Sternocostoclavicular hyperostosis (SCCH) is a rare, debilitating, chronic inflammatory disorder of the anterior chest wall due to a chronic sterile osteomyelitis of unknown origin, often associated with characteristic skin lesions of palms and soles: pustulosis palmoplantaris. SCCH goes often unrecognized for years before the diagnosis is established and treatment instituted. The objective of this study was to trace the diagnostic paths of patients with SCCH and to investigate the consequences associated with diagnostic delay.

Methods

Data were collected through structured interviews of 52 patients with a clinically, scintigraphically, and radiologically established diagnosis of SCCH.

Results

The majority of patients presented with swelling and/or pain in the sternocostoclavicular region and/or limited movement of the shoulder girdle. Pustulosis palmoplantaris was present in ∼30% of patients. The disease went unrecognized for a median of 3.5 years. Patients were often seen by at least 3 members of the medical profession before the diagnosis was suspected and eventually established. Lack of recognition of the clinical manifestations of the disease and delay in diagnosis were associated with important physical, psychological, and socioeconomic consequences affecting quality of life.

Conclusion

SCCH remains an ill‐recognized disease despite its characteristic clinical features. A low level of awareness of the disorder leads to a delay in diagnosis, which has a significant impact on various aspects of quality of life. Awareness should be raised for this disorder, enabling timely diagnosis and initiation of treatment to prevent the irreversible physical and psychological sequelae associated with the protracted untreated state.
Titelbild: Metal–Organic Spheres as Functional Systems for Guest Encapsulation (Angew. Chem. 13/2009)
Authors: Imaz Inhar , Hernando Jordi , Ruiz‐Molina Daniel , Maspoch Daniel
Published: January 2010

Die unendliche Koordinationspolymerisation von Metallionen und multitopen organischen Liganden führt zu metall‐organischen Mikro‐ und Nanokugeln, die als funktionelle Matrices verwendet werden können. In ihrer Zuschrift auf S. 2361 ff. nutzen D. Maspoch et al. diesen einfachen Prozess, um multifunktionelle Kugeln zu erhalten, in denen aktive Substanzen wie magnetische Nanopartikel, organische Farbstoffe und Quantenpunkte eingeschlossen sind. (Das Titelbild wurde von Marianne Verdoux erstellt.)

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Innentitelbild: A Phosphine‐Mediated Conversion of Azides into Diazo Compounds (Angew. Chem. 13/2009)
Authors: Myers Eddie L. , Raines Ronald T.
Published: January 2010

Im Jahr 1919 berichteten H. Staudinger und J. Meyer über die reduktive Fragmentierung eines Azids zu einem Amin. Auf S. 2395 ff. stellen nun E. L. Myers und R. T. Raines ein ergänzendes Verfahren vor: die Spaltung der anderen N‐N‐Bindung eines Azids unter Bildung einer Diazoverbindung. Weil in beiden Umsetzungen ein Phosphor(III)‐Reagens zur Anwendung kommt, wurde als Hintergrund das Bild The Alchymist, in Search of the Philosopher's Stone, Discovers Phosphorus aus dem Jahr 1771 gewählt, in dem Joseph Wright die Entdeckung des Phosphors durch Hennig Brandt im Jahr 1669 darstellt. (Gestaltung: H. Adam Steinberg)

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Zwitterionic Relatives of Cationic Platinum Group Metal Complexes: Applications in Stoichiometric and Catalytic σ‐Bond Activation
Authors: Stradiotto Mark , Hesp Kevin D. , Lundgren Rylan J.
Published: January 2010

Zwitterionic platinum group metal complexes that feature formal charge separation between a cationic metal fragment and a negatively charged ancillary ligand combine the desirable reactivity profile of related cationic complexes with the broad solubility and solvent tolerance of neutral species. As such, zwitterionic complexes of this type have emerged as attractive candidates for a diversity of applications, most notably involving the breaking and/or forming of EH and EC σ bonds involving a main group element E. Important advances in ancillary ligand design are documented that have enabled the construction of platinum group metal zwitterions. Also summarized are the results of stoichiometric and catalytic investigations in which the reactivity of such zwitterions and their more traditionally employed cationic relatives in σ bond activation chemistry are compared and contrasted.
Cover Picture: Metal–Organic Spheres as Functional Systems for Guest Encapsulation (Angew. Chem. Int. Ed. 13/2009)
Authors: Imaz Inhar , Hernando Jordi , Ruiz‐Molina Daniel , Maspoch Daniel
Published: January 2010

The infinite coordination polymerization…︁ of metal ions and multitopic organic ligands is explored to fabricate metal–organic micro‐ and nanospheres that can be used as functional matrices. In their Communication on page 2325 ff., D. Maspoch and co‐workers show how this simple process affords spheres that encapsulate active substances, such as magnetic nanoparticles, organic dyes, and quantum dots, to result in multifunctional spheres. Marianne Verdoux is thanked for the cover graphic design.

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Synthetic, spectral as well as in vitro antimicrobial studies on some bismuth(III) bis(N,N‐dialkyldithiocarbamato) alkylenedithiophosphates
Authors: Chauhan H. P. S. , Bakshi Abhilasha , Bhatiya Sumit
Published: January 2010

Mixed sulfur donor ligand complexes of the type bismuth(III) bis(N,N‐dialkyldithiocarbamato) alkylenedithiophosphate, [R2NCS2]2BiS2POGO [where R = CH3 and C2H5; G = ‐CH2‐C(C2H5)2‐CH2‐, ‐CH2‐C(CH3)2‐CH2‐, ‐CH(CH3)‐CH(CH3)‐ and ‐C(CH3)2‐C(CH3)2‐] were synthesized in 1:1 molar ratio of bismuth(III) bis(N,N‐dialkyldithiocarbamate) chloride and ammonium alkylenedithiophosphate in refluxing benzene and characterized by melting point, molecular weight determinations, elemental analysis (C, H, N, Bi and S) and spectral [UV, IR,NMR (1H,13C and 31P) and powder X ray diffraction] studies; all these studies were in good agreement with the synthesized complexes. These newly synthesized derivatives are yellow and brown colored solids and are soluble in common organic solvents like benzene, chloroform, dichloromethane and DMF. Based on the physicochemical and spectral studies, a tentative structure of these newly synthesized complexes was assigned and the average particle size of the synthesized complexes determined by powder XRD, showing that nano range polycrystalline particles were formed with a monoclinic crystal system. These complexes were also screened for their antimicrobial activities using the well diffusion method. The free ligands as well as their mixed metal complexes were tested in vitro against four bacterial strains: two Gram‐positive, Staphylococcus aureus (ATCC 9144) (G+) and Bacillus subtilis (ATCC 6051), (G+) and two Gram‐negative, Escherichia coli (ATCC 9637) (G−) and Pseudomonas aeruginosa (ATCC 25619) (G−) to assess their antimicrobial properties. The results were indeed positive and exhibited good antibacterial effects. Chloroamphenicol used as a standard for comparison and synthesized complexes showed good antibacterial effects over chloroamphenicol. On the basis of these studies, the synthesized complexes help to understand the different structural and biological properties of main group elements with sulfur donor ligands. Copyright © 2010 John Wiley & Sons, Ltd.
Synthesis and characterization of (Fe3O4/MWCNTs)/ epoxy nanocomposites
Authors: Jones Wanda D. , Rangari Vijaya K. , Hassan Tarig A. , Jeelani Shaik
Published: January 2010

A sonochemical technique is used for in situ coating of iron oxide (Fe3O4) nanoparticles on outer surface of MWCNTs. These Fe3O4/MWCNTs were characterized using a high‐resolution transmission electron microscope (HRTEM), X‐ray diffraction, and thermogravimetric analysis. The as‐prepared Fe3O4/MWCNTs composite nanoparticles were further used as reinforcing fillers in epoxy‐based resin (Epon‐828). The nanocomposites of epoxy were prepared by infusion of (0.5 and 1.0 wt %) pristine MWCNTs and Fe3O4/MWCNTs composite nanoparticles. For comparison purposes, the neat epoxy resin was also prepared in the same procedure as the nanocomposites, only without nanoparticles. The thermal, mechanical, and morphological tests were carried out for neat and nanocomposites. The compression test results show that the highest improvements in compressive modulus (38%) and strength (8%) were observed for 0.5 wt % loading of Fe3O4/MWCNTs. HRTEM results show the uniform dispersion of Fe3O4/MWCNTs nanoparticles in epoxy when compared with the dispersion of MWCNTs. These Fe3O4/MWCNTs nanoparticles‐infused epoxy nanocomposite shows an increase in glass transition (Tg) temperature. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
New melamine–formaldehyde–ketone resins. VI. Preparation of filled molding compositions and compression‐molding materials from reactive solvents based on cyclohexanone
Authors: Głowacz‐Czerwonka Dorota , Kucharski Mieczysław
Published: January 2010

The conditions and a method of preparing new molding compositions and filled compression‐molding materials from melamine–formaldehyde–cyclohexanone resins are described. The resins were obtained from melamine solutions in a reactive solvent prepared by the reaction of 1 mol of cyclohexanone with 7 mol of formaldehyde. The fillers were wood powder and sulfite cellulose. The thermal properties of the samples prepared from the compositions were studied with dynamic thermal analysis, thermogravimetry, and differential scanning calorimetry analysis. Selected mechanical properties [Brinell hardness, unnotched impact strength (Charpy method), and bending strength] of the cured resins were also measured. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Effect of natural polyphenols on physicochemical properties of crosslinked gelatin‐based polymeric biocomposite
Authors: Haroun A. A. , El Toumy S. A.
Published: January 2010

This work was aimed to study the effect of natural polyphenols extract (Acacia nilotica bark) on physicochemical properties of crosslinked gelatin‐poly(acrylamide‐co‐acrylic acid), Gel‐poly(AAm‐co‐Ac), polymeric biocomposite film. Gelatin‐based composite films have extensive application as biocompatible biomaterial as drug carriers, cosmetics, and agricultural food packaging. The prepared composite films were characterized using Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC), in addition to the swelling and degradation behavior. UV‐Vis absorption spectra and scanning electron microscopy (SEM) were also applied to observe the interaction between Gel‐poly(AAm‐co‐Ac) and natural polyphenol (catechin). The study has demonstrated that the involvement of hydrogen bonding and hydrophobic interactions as the major forces involved in the stabilization of gelatin‐based polymeric biocomposite film by the plant polyphenols (catechin and gallic acid derivatives). Thermal stability studies of crosslinked gelatin‐based composite film revealed that A. nilotica bark extract stabilizes the gelatin molecules and leads to moderate increase of the denaturation temperatures relative to the uncrosslinked one. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Studies on polymeric conservation treatments of ceramic tiles with Paraloid B‐72 and two alkoxysilanes
Authors: Constâncio Célia , Franco Liliana , Russo Ariana , Anjinho Carlos , Pires João , Vaz M. Fátima , Carvalho Ana P.
Published: January 2010

The aim of this study was to evaluate the effect of different polymeric protections applied on ceramic tiles on their mechanical and water absorption properties. Three conservation products were used: the acrylic polymer Paraloid B‐72 and two alkoxysilane‐based formulations (tetraethoxysilane (TEOS) and IN2210, a polidimetilsiloxane‐based formulation). The coatings were applied onto handmade tiles manufactured according to a 18th century procedure. Different application procedures (immersion, brushing, and spraying) were tested. The protection effectiveness was assessed through capillary water absorption and four point bending tests. The mineralogical characterization of tiles was undertaken by XRD. The best protective properties of the tiles were achieved by immersion treatments with Paraloid B‐72 based on the protocols followed by the museums restoration departments. Nevertheless, the results of the present work show that the second immersion in Paraloid B‐72 solution, commonly made, can be eliminated, as it does not provide any significant increase in the hydrophobic or mechanical properties of the tiles. As a result, there are obvious economical benefits, as the coating process became less time‐consuming and more environmental friendly, as the amount of organic compounds is reduced. On the other hand, the use of small volumes of Paraloid B‐72 solution applied by brush, or IN2210 sprayed can provide good results, if the only purpose of the treatment is the increase of the hydrophobic properties. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Microwave assisted polycondensation of polyimides by [4,4′‐(hexafluoroisopropylidene)diphthalic anhydride, pyromellitic dianhydride] and [2,4,6‐trimethyl‐m‐phenylenediamine]. Power, time, and solvent effect
Authors: Tellez Hugo Mendoza , Alquisira Joaquín Palacios , López‐Cortés José Guadalupe , Alvarez‐Toledano Cecilio
Published: January 2010

The microwave assisted polycondensation of two polyimides were studied using pyromellitic dianhydride (PMDA), and 4,4′‐(hexafluoroisopropyliden)diphthalic anhydride (6FDA) as dianhydride monomers and 2,4,6‐trimethyl‐m‐phenylenediamine (TrmPD), as diamine monomer, under microwave irradiation in DMF and DMSO solvents. The structure and performance of polymers were characterized by Fourier Transform Infrared Spectroscopy (FTIR), viscosity, density, and Thermogravimetric Analysis (TGA). The results show that the polyimides can be obtained in a short reaction time with high intrinsic viscosity and high yield. The effect of the presence of a bridging group, C(CF3)2, in the monomer structure is apparent in the permeability parameters of the macromolecules as polymer (6FDA‐TrmPD) always presents better results than polymer (PMDA‐TrmPD). Properties as density and Tg increases with the time exposition to the microwave irradiation. Polyimides obtained present good thermal properties because they began to lose weight in a range of 8–16% at high temperature as 450°C. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Melamine‐bridged alkyl resorcinol modified urea–formaldehyde resin for bonding hardwood plywood
Authors: Hse Chung‐Yun , Higuchi Mitsuo
Published: January 2010

A powdery product was obtained by the reaction of methylolated melamine with alkyl resorcinols to form melamine‐bridged alkyl resorcinols (MARs). The effects of the addition of this powder on the bonding strength and formaldehyde emission of urea–formaldehyde (UF) resins were investigated. Three types of UF resins with a formaldehyde/urea molar ratio of 1.3 synthesized by condensation at pH 1.0 (UF‐1.0), pH 4.5 (UF‐4.5), and pH 5.0 (UF‐5.0) were fabricated. The addition of MAR to UF‐4.5 and UF‐5.0 for bonding hardwood plywood enhanced the bonding strength and reduced formaldehyde emission. For UF‐1.0, the addition of MAR adversely affected the bonding strength. However, the UF‐1.0 resin yielded the lowest formaldehyde emission of all of the UF resins in the study. The effects of the MAR addition were related to the molecular structures of the UF resins. UF‐1.0 contained a large amount of free urea, a considerable number of urons, and a highly methylene‐linked, ring‐structured higher molecular weight fraction and had a smaller number of methylol groups. Therefore, the addition of MAR was considered to cause a shortage of the methylol groups, which in turn, led to incomplete resin curing. In contrast to UF‐1.0, UF‐5.0 contained a smaller amount of free urea and a linearly structured higher molecular weight fraction and had a larger number of methylol groups. In this case, MAR was considered to effectively react with the methylol groups to develop a three‐dimensional crosslinked polymer network to enhance the bonding strength and suppress the generation of free formaldehyde to reduce formaldehyde emission. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Design and performance evaluation of multilayer packaging films for blister packaging applications
Authors: Hwang S. W. , Shim J. K. , Lee S. B. , Auras R.
Published: January 2010

Five multilayer packaging film structures consisting of amorphous poly(ethylene terephthalate) (APET), low‐density polyethylene (LDPE), polypropylene (PP), and acrylonitrile/methyl acrylate copolymer (Barex) films [i.e., APET/polyethylene (PE), APET/PP, APET/PE + UV inhibitor, APET/PP/PE, and APET/Barex/PP] for blister packaging applications were designed and produced. Blister containers with APET/PE and APET/Barex/PP structures were prepared, and their optical, mechanical, barrier (O2, CO2, and H2O), physical, and product/package compatibility performance properties were evaluated. Package/product compatibility with simulants (soy sauce and sunscreen skin cream) at 37.8°C was evaluated for 3, 7, 14, and 28 days in the multilayer films and the blister containers. APET/Barex/PP film showed significantly better O2 and CO2 barrier performance than the other four film structures. The UV inhibitor had no significant effect on the barrier properties in the APET/PE film structure. All of the film structures showed high enough elastic storage modulus values to be applied to blister packaging in a broad range of temperatures between −45 and 80°C. The glass‐transition temperature of APET, which was responsible for the elastic modulus of the multilayer structure, decreased after the samples were exposed to the skin cream. This decrease may have been due to the sorption of the skin cream's active ingredients, such as ethylhexyl methoxycinnamate. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis and application of modified starch as a shell–core main adhesive in a foundry
Authors: Zhou Xia , Yang Jinzong , Qian Feng , Qu Guohui
Published: January 2010

To be used as an alternative adhesive for sand cores in a foundry, a solid water‐soluble modified starch [carboxymethyl starch (CMS)] was synthesized by a new dry reaction process. With this process, a series of CMS products was obtained with degrees of substitution (DSs) ranging from 0.25 to 0.78 at a high reaction efficiency and characterized with regard to their molecular structure and aqueous solution viscosity. On the basis of the dry synthesis of CMS, the properties of CMS‐bonded shell–core sand were investigated, and practical production experiments were carried out. The results show that there was a new sharp peak in the infrared spectrum that represented the carboxymethyl groups and formation of CMS. The viscosity of the CMS aqueous solution increased with increasing DS and amount of CMS. When DS was in the range 0.3–0.5 and the mass fraction was 5–7%, the CMS aqueous solution had a suitable viscosity, which was helpful for the improvement of the properties, such as flowability, permeability, and strength, of the CMS core sand. In addition, a CMS shell–core with an appropriate wall thickness (10–20 mm) for the purpose of obtaining both sufficient strength and permeability could be made with the CMS‐bonded core sand and a hot‐core‐box process. The final pouring results prove that high‐quality iron castings with smooth inner cavities could be produced with the CMS‐bonded shell–core and that it (namely the CMS‐bonded shell‐core) could be used as a replacement for the furan resin‐bonded sand core. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Influence of starch and glycerol on the properties of chitosan by positron annihilation spectroscopy
Authors: Abd El Wahab M. , Abdou E. S.
Published: January 2010

Two types of chitosan (CS), α and β, were blended with different concentrations of starch and cast to obtain films. The addition of 1% glycerol was used as a plasticizer to increase film flexibility. The properties of the obtained films were studied by positron annihilation lifetime spectroscopy, X‐ray diffraction, and scanning electron microscopy. The results indicate that pure β‐CS had smaller size free‐volume holes with high fractions than pure α‐CS; this was attributed to the difference in bonding of main chains in β‐CS. The addition of starch (>20% up to 50%) reduced the size of the free‐volume holes and increased their fraction because of the close packing of chain segments. The effect of 1% glycerol to the CS starch blends indicated that some modification took place. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Effects of membrane thickness and heat treatment on the gas transport properties of membranes based on P84 polyimide
Authors: Shen Yi , Lua Aik Chong
Published: January 2010

P84 polyimide membranes with thicknesses ranging from 6 to 310 μm were successfully fabricated by spin coating. The glass transition temperature of the P84 powder was found to be 315°C using differential scanning calorimetry, whereas its decomposition temperature was 536°C using thermogravimetric analysis. Scanning electron microscopy was used to examine the morphology of the membranes. The permeability of single gas (He, N2, O2, and CO2) and the ideal selectivity of gas pair (O2/N2, He/CO2, CO2/N2, and He/O2), as a function of membrane thickness, were determined. The results showed that the permeability of a single gas increased with increasing membrane thickness, whereas the selectivity of a given gas pair was nearly independent of the membrane thickness. The average selectivity of O2/N2, He/CO2, CO2/N2, and He/O2 were found to be 8.2, 10.0, 12.9, and 15.8, respectively. The effects of heat treatment on the membrane morphology and gas transport properties were investigated for three annealing temperatures, i.e., 80°C, 200°C, and 315°C. The membrane annealed at 315°C was cracked due to the stress sustained either during heating or cooling, thereby resulting in little or no selectivity. The permeabilities of P84‐118 membrane (118 μm thickness) annealed at 80°C were 16.2, 0.196, 1.20, and 2.01 Barrer for He, N2, O2, and CO2, respectively. The permeabilities of P84‐118 membrane annealed at 200°C decreased by 9.75%, 47.96%, 25.83%, and 30.85% for He, N2, O2, and CO2, respectively, as compared with those at 80°C, whereas the ideal selectivities increased by 42.65%, 30.52%, 32.85%, and 21.63% for O2/N2, He/CO2, CO2/N2, and He/O2, respectively. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Unique stimuli responsive characteristics of electron beam synthesized bacterial cellulose/acrylic acid composite
Authors: Halib Nadia , Amin Mohd Cairul Iqbal Mohd , Ahmad Ishak
Published: January 2010

The formation and swelling behavior of bacterial cellulose/acrylic acid hydrogel prepared from aqueous mixture consists of 20 : 80 (v/v) acrylic acid (AAc) and 1% bacterial cellulose dispersion under accelerated electron beam was investigated. Gel fraction of hydrogel increased with the increasing dose suggesting a denser composite at 50 kGy compared to 35 kGy. SEM photomicrographs revealed a homogenous pores distribution at higher dose with pore sizes ranging from 1 to 5 μm. Hydrogel synthesized at lower dose of electron beam exhibited higher swelling ability and the degree of swelling increased as the pH of surrounding medium increased and it reached the optimum swelling at pH 7. While swelling of the hydrogel decreased with the increasing ionic strength of solution, swelling at different temperatures ranging from 25 to 50°C revealed a unique character where the hydrogel shrunk at 37°C. Moreover, hydrogel synthesized at higher dose exhibited a higher degree of swelling in methanol with respect to water. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Competitive adsorption between an AMPS®‐based fluid loss polymer and Welan gum biopolymer in oil well cement
Authors: Plank Johann , Lummer Nils Recalde , Dugonjić‐Bilić Fatima
Published: January 2010

Water‐soluble 2‐acrylamido‐2‐methylpropane sulfonic acid (AMPS®)‐based copolymers are commonly used to provide water retention (fluid loss control) for oil well cement slurries. Here, the fluid loss performance of a CaAMPS®‐N,N‐dimethylacrylamide copolymer (CaAMPS®‐co‐NNDMA) in the presence of Welan gum, an anionic microbial biopolymer produced by anaerobic fermentation using Alcaligenes ATCC 31555 bacteria was investigated at 80°C. Welan gum is used to control unwanted free water development at the surface of the cement slurry. The effectiveness of CaAMPS®‐co‐NNDMA fluid loss additive (FLA) solely relies on its high adsorption onto the positively charged surfaces of cement hydrates. Adsorption of the FLA is, however, perturbed by Welan gum. This anionic polysaccharide competes with CaAMPS®‐co‐NNDMA for adsorption sites on the cement surface. This effect is surprising because in cement pore solution, Welan gum exhibits a much lower specific anionic charge amount than CaAMPS®‐co‐NNDMA. The reason is that Welan gum possesses carboxylate functionalities, which are much stronger anchor groups than the sulfonate groups present in CaAMPS®‐co‐NNDMA. The superiority of the carboxylate groups regarding their affinity to the mineral surface, which possesses insufficiently coordinated Ca atoms is confirmed by a higher calcium binding capability for Welan gum than for the FLA. Thus, Welan gum can reduce effectiveness of CaAMPS®‐co‐NNDMA as fluid loss agent by preventing its adsorption or through displacement of already adsorbed FLA molecules from the surface of cement. In multiadmixture systems, which are commonly used in oil well cement, concrete or mortars, competitive adsorption between different additives for surface sites can negatively impact the performance of these additives. Understanding the reasons behind can help to develop more effective admixture systems. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Genetic variation at the IRF7/PHRF1 locus is associated with autoantibody profile and serum interferon‐α activity in lupus patients
Authors: Salloum Rafah , Franek Beverly S. , Kariuki Silvia N. , Rhee Lesley , Mikolaitis Rachel A. , Jolly Meenakshi , Utset Tammy O. , Niewold Timothy B.
Published: January 2010

Objective

Interferon‐α (IFNα) is a heritable risk factor for systemic lupus erythematosus (SLE). Genetic variation near IRF7 is implicated in SLE susceptibility. SLE‐associated autoantibodies can stimulate IFNα production through the Toll‐like receptor/IRF7 pathway. This study was undertaken to determine whether variants of IRF7 act as risk factors for SLE by increasing IFNα production and whether autoantibodies are important to this phenomenon.

Methods

We studied 492 patients with SLE (236 African American, 162 European American, and 94 Hispanic American subjects). Serum levels of IFNα were measured using a reporter cell assay, and single‐nucleotide polymorphisms (SNPs) in the IRF7/PHRF1 locus were genotyped.

Results

In a joint analysis of European American and Hispanic American subjects, the rs702966 C allele was associated with the presence of anti–double‐stranded DNA (anti‐dsDNA) antibodies (odds ratio [OR] 1.83, P = 0.0069). The rs702966 CC genotype was only associated with higher serum levels of IFNα in European American and Hispanic American patients with anti‐dsDNA antibodies (joint analysis P = 4.1 × 10−5 in anti‐dsDNA–positive patients and P = 0.99 in anti‐dsDNA–negative patients). In African American subjects, anti‐Sm antibodies were associated with the rs4963128 SNP near IRF7 (OR 1.95, P = 0.0017). The rs4963128 CT and TT genotypes were associated with higher serum levels of IFNα only in African American patients with anti‐Sm antibodies (P = 0.0012). In African American patients lacking anti‐Sm antibodies, an effect of anti‐dsDNA–rs702966 C allele interaction on serum levels of IFNα was observed, similar to the other patient groups (overall joint analysis P = 1.0 × 10−6). In European American and Hispanic American patients, the IRF5 SLE risk haplotype showed an additive effect with the rs702966 C allele on IFNα level in anti‐dsDNA–positive patients.

Conclusion

Our findings indicate that IRF7/PHRF1 variants in combination with SLE‐associated autoantibodies result in higher serum levels of IFNα, providing a biologic relevance for this locus at the protein level in human SLE in vivo.
Bim–Bcl‐2 homology 3 mimetic therapy is effective at suppressing inflammatory arthritis through the activation of myeloid cell apoptosis
Authors: Scatizzi John C. , Hutcheson Jack , Pope Richard M. , Firestein Gary S. , Koch Alisa E. , Mavers Melissa , Smason Avraham , Agrawal Hemant , Haines G. Kenneth , Chandel Navdeep S. , Hotchkiss Richard S. , Perlman Harris
Published: January 2010

Objective

Rheumatoid arthritis (RA) is a destructive autoimmune disease characterized by an increased inflammation in the joint. Therapies that activate the apoptotic cascade may have potential for use in RA; however, few therapeutic agents fit this category. The purpose of this study was to examine the potential of Bim, an agent that mimics the action of Bcl‐2 homology 3 (BH3) domain–only proteins that have shown success in preclinical studies of cancer, in the treatment of autoimmune disease.

Methods

Synovial tissues from RA and osteoarthritis patients were analyzed for the expression of Bim and CD68 using immunohistochemistry. Macrophages from Bim−/− mice were examined for their response to lipopolysaccharide (LPS) using flow cytometry, real‐time polymerase chain reaction analysis, enzyme‐linked immunosorbent assay, and immunoblotting. Bim−/− mice were stimulated with thioglycollate or LPS and examined for macrophage activation and cytokine production. Experimental arthritis was induced using the K/BxN serum–transfer model. A mimetic peptide corresponding to the BH3 domain of Bim (TAT‐BH3) was administered as a prophylactic agent and as a therapeutic agent. Edema of the ankles and histopathologic analysis of ankle tissue sections were used to determine the severity of arthritis, its cellular composition, and the degree of apoptosis.

Results

The expression of Bim was reduced in RA synovial tissue as compared with controls, particularly in macrophages. Bim−/− macrophages displayed elevated expression of markers of inflammation and secreted more interleukin‐1β following stimulation with LPS or thioglycollate. TAT‐BH3 ameliorated arthritis development, reduced the number of myeloid cells in the joint, and enhanced apoptosis without inducing cytotoxicity.

Conclusion

These data demonstrate that BH3 mimetic therapy may have significant potential for the treatment of RA.
Nonsteroidal antiinflammatory drugs and prostaglandin E2 modulate the synthesis of osteoprotegerin and RANKL in the cartilage of patients with severe knee osteoarthritis
Authors: Moreno‐Rubio Juan , Herrero‐Beaumont Gabriel , Tardı´o Lidia , álvarez‐Soria M. ángeles , Largo Raquel
Published: January 2010

Objective

Although the osteoprotegerin (OPG)/RANK/RANKL system is the main modulator of bone remodeling, it remains unclear whether it is regulated in cartilage during osteoarthritis (OA). The aim of this study was to examine whether nonsteroidal antiinflammatory drug (NSAID) treatment modulates the synthesis of OPG and RANKL in the cartilage of patients with OA, and to investigate whether prostaglandin E2 (PGE2) modifies this system in human OA chondrocytes in culture.

Methods

A 3‐month clinical trial was carried out in 20 patients with severe knee OA, all of whom were scheduled to undergo knee replacement surgery. Ten of these patients were treated with celecoxib, and the other 10 patients, who did not want to be treated, served as the control group. After surgery, cartilage was processed for molecular biology studies. We also used human OA chondrocytes to examine the effects of PGE2 on OPG/RANKL synthesis, examining which surface receptors were affected by PGE2.

Results

In patients with OA, celecoxib decreased RANKL synthesis in the cartilage, thereby increasing the OPG:RANKL ratio. In human OA chondrocytes in culture, PGE2 elicited a dose‐ and time‐dependent increase in the synthesis of RANKL, the extent of which was greater than that of OPG. Confocal microscopy revealed that PGE2 induced RANKL transport to the cell membrane. Only EP2/EP4 agonists reproduced the effects of PGE2 on OPG and RANKL induction.

Conclusion

Long‐term NSAID treatment inhibited the resorptive signal synthesized by chondrocytes. In vitro, PGE2 regulated the expression and release of these key mediators of bone metabolism by articular chondrocytes. The role of OPG/RANK/RANKL in OA cartilage metabolism is still unknown, although the synthesis of these proteins would enable the cartilage to control the activity of subchondral bone cells.
A four‐gene biomarker predicts skin disease in patients with diffuse cutaneous systemic sclerosis
Authors: Farina G. , Lafyatis D. , Lemaire R. , Lafyatis R.
Published: January 2010

Objective

Improved outcome measures in systemic sclerosis (SSc) are critical to finding active therapeutics for this disease. The modified Rodnan skin thickness score (MRSS) is the current standard for evaluating skin disease in SSc, but it is not commonly used in the clinical setting, in part because it requires specialized training to perform accurately and consistently. The purpose of this study was to investigate whether skin gene expression might serve as a more objective surrogate outcome measure to supplement skin score evaluations.

Methods

Skin RNAs from a group of patients with diffuse cutaneous SSc were studied for expression levels of genes known to be regulated by transforming growth factor β (TGFβ) and interferon (IFN). These levels were correlated with the MRSS, using multiple regression analyses to obtain best‐fit models.

Results

Skin expression of the TGFβ‐regulated genes cartilage oligomeric matrix protein (COMP) and thrombospondin 1 (TSP‐1) correlated moderately well with the MRSS, but the addition of other TGFβ‐regulated genes failed to significantly improve best‐fit models. IFN‐regulated genes were also found to correlate with the MRSS, and the addition of interferon‐inducible 44 (IFI44) and sialoadhesin (Siglec‐1) to COMP and TSP‐1 in multiple regression analyses significantly improved best‐fit models, achieving an R2 value of 0.89. These results were validated using an independent group of skin biopsy samples. Longitudinal scores using this 4‐gene biomarker indicated that it detects change over time that corresponds to changes in the MRSS.

Conclusion

We describe a 4‐gene predictor of the MRSS and validate its performance. This objective measure of skin disease could provide a strong surrogate outcome measure for patient care and for clinical trials.