bluuebunny/crossref_metadata_2025 huggingface dataset:
What motivates hate crimes based on sexual orientation? Mediating effects of anger on antigay aggression
Authors: Parrott Dominic J. , Peterson John L.
Published: December 2007

The aim of this study was to examine the role of anger in response to gay men within three theoretical models of antigay aggression. Participants were 135 exclusively heterosexual men who completed a structured interview designed to assess sexual prejudice, anger in response to a vignette depicting a nonerotic male–male intimate relationship (i.e. partners saying “I love you”, holding hands, kissing), and past perpetration of antigay aggression. Among identified antigay assailants, motivations for one earlier assault (i.e. sexual prejudice, peer dynamics, thrill seeking) were also assessed. Results indicated that anger fully mediated the relationship between sexual prejudice and antigay aggression, partially mediated the effect of peer dynamics on antigay aggression, and did not account for the relationship between thrill seeking and antigay aggression. These findings indicate that anger in response to gay men facilitates antigay aggression among some, but not all, antigay perpetrators. Aggr. Behav. 34:306–318, 2008. © 2007 Wiley‐Liss, Inc.
Experimental study of the differential effects of playing versus watching violent video games on children's aggressive behavior
Authors: Polman Hanneke , de Castro Bram Orobio , van Aken Marcel A.G.
Published: December 2007

There is great concern about the effects of playing violent video games on aggressive behavior. The present experimental study was aimed at investigating the differential effects of actively playing vs. passively watching the same violent video game on subsequent aggressive behavior. Fifty‐seven children aged 10–13 either played a violent video game (active violent condition), watched the same violent video game (passive violent condition), or played a non‐violent video game (active non‐violent condition). Aggression was measured through peer nominations of real‐life aggressive incidents during a free play session at school. After the active participation of actually playing the violent video game, boys behaved more aggressively than did the boys in the passive game condition. For girls, game condition was not related to aggression. These findings indicate that, specifically for boys, playing a violent video game should lead to more aggression than watching television violence. Aggr. Behav. 34:256–264, 2008. © 2007 Wiley‐Liss, Inc.
An analytical model for internal moisture content during the decreasing drying rate period
Authors: Derdour L. , Desmorieux H.
Published: December 2007

A system of analytical expressions for internal moisture distribution during the falling drying rate period for porous nonhygroscopic slabs is presented. This model is derived by resolution of thermal balance and mass flux continuity equations and on the assumption of a parabolic internal moisture profile in the liquid transport zone. This study is based on the assumption of the existence of a receding evaporative front within the product during the decreasing drying rate period and on heat transfer being the limiting mechanism. The model addresses the cases where heat transfer is the limiting mechanism during drying and applies to flat slabs which are classified into two groups, namely, thick products and thin products, depending on their thicknesses and drying conditions. Overall, the model predictions were in a slight deviation from experimental data obtained on plaster. © 2007 American Institute of Chemical Engineers AIChE J, 2008
Investigation of batch fluidized‐bed drying by mathematical modeling, CFD simulation and ECT measurement
Authors: Wang H. G. , Yang W. Q. , Senior P. , Raghavan R. S. , Duncan S. R.
Published: December 2007

Mathematical modeling, computational fluid dynamics (CFD) analysis and electrical capacitance tomography (ECT) is used to develop an understanding of batch fluidized‐bed drying, which is a complex air‐solids, multiphase process. The mathematical model is based on a three‐phase theory that describes the mass‐and heat‐transfer between the air and solids phases. The CFD model is based on a two‐fluid model (TFM) approach, in which both phases are considered to be continuous and fully interpenetrating. The hydrodynamic parameters used to model the heat‐and mass‐transfer between the two phases are determined by a correlation approach, and the estimated parameters are incorporated into a user defined function (UDF) in FLUENT. The moisture diffusion in the air and solids phases is simulated using the user defined scalar (UDS) transport equation in the software package. ECT is used for the online solids concentration and moisture measurement, based on dynamic calibration. Comprehensive comparisons between results from mathematical modeling, CFD simulation and ECT measurement are presented, and are validated using experiment results. Online measurement of moisture content is compared with a static calibration. The mathematical model, CFD and ECT presented are being integrated into an online process control system for a batch fluidized‐bed drying application in the pharmaceutical industry. © 2007 American Institute of Chemical Engineers AIChE J, 2008
Danazol therapy for aplastic anemia refractory to immunosuppressive therapy
Authors: Chuhjo Tatsuya , Yamazaki Hirohito , Omine Mitsuhiro , Nakao Shinji
Published: December 2007

Although there are anecdotal reports of the efficacy of danazol in the treatment of aplastic anemia (AA), there has been no systematic study to clarify its efficacy and toxicity. Therefore, we assessed the efficacy of danazol for treatment of patients with AA refractory to immunosuppressive therapy (IST) and those who relapsed after IST, in a prospective clinical trial. Sixteen patients (12 males and four females; six severe cases and 10 moderate cases) were treated with 300 mg of danazol daily for 12 weeks. All patients completed the treatment period without occurrence of severe toxicity. Three female patients achieved partial remission, whereas only two of the 12 male patients did so. None of the responders had shown a response to previous IST or an increase in the percentage of paroxysmal nocturnal hemoglobinuria (PNH)‐type cells which are known to be a marker for a good response to IST. These findings indicate that danazol is effective for a subset of AA patients, and particularly for female patients with AA refractory to IST. Am. J. Hematol., 2008. © 2007 Wiley‐Liss, Inc.
Validation of a targeted DNA microarray for the clinical evaluation of recurrent abnormalities in chronic lymphocytic leukemia
Authors: Patel Ankita , Kang Sung‐Hae , Lennon Patrick Alan , Li Yin Feng , Rao P. Nagesh , Abruzzo Lynne , Shaw Chad , Chinault Alan Craig , Cheung Sau W
Published: December 2007

Recurrent genomic alterations, mainly losses and gains of specific chromosomes and/or regions, in chronic lymphocytic leukemia (CLL) are recognized as important independent predictors of prognosis and disease progression. The current standard clinical practice for identifying these alterations is chromosome analysis and in situ hybridization with probes targeting 4–5 chromosome regions. We sought to apply array comparative genomic hybridization (array‐CGH) technology for the simultaneous detection of genomic imbalances of all loci implicated in CLL. DNA from enriched B‐cells from CLL patients were analyzed by array‐CGH on a customized CLL BAC array. Copy number changes were detected in 87% of samples with a sensitivity of 100% in samples with clonal abnormalities present in at least 23% of the cells. Furthermore, in nine cases genomic alterations were observed that were undetectable by standard cytogenetic and/or FISH analyses. One of these patients had a 13q14 deletion that was missed by the clinical CLL FISH panel probe set. Our results suggest that a subset of potentially significant genomic alterations in CLL is being missed by the current available techniques. Furthermore, this pilot study clearly shows the robustness, high sensitivity, and high specificity for the targeted CLL microarray analysis as well as the potential for use in routine screening in CLL. Am. J. Hematol., 2008. © 2007 Wiley‐Liss, Inc.
Occupational hypersensitivity pneumonitis due to molds in an onion and potato sorter
Authors: Merget R. , Sander I. , Rozynek P. , Raulf‐Heimsoth M. , Bruening T.
Published: December 2007

A 42‐year‐old female non‐smoking onion and potato sorter developed work‐related shortness of breath, cough, fatigue and flu‐like symptoms. The diagnosis of hypersensitivity pneumonitis was based on patchy infiltrates in both lungs on high resolution computed tomography and lymphocytosis of 71% in a bronchoalveolar lavage sample with a CD4/CD8 ratio of 0.4. Exposure cessation and initial corticosteroid therapy resulted in complete recovery. IgG antibodies to Penicillium species and Fusarium solani cultivated from samples from the patient's workplace were detected in the patient's serum and cross‐reactivity was demonstrated within Penicillium species, but also between Penicillium species and Aspergillus fumigatus. We conclude that occupational hypersensitivity pneumonitis due to molds may develop in onion and potato sorters. Am. J. Ind. Med. 51:117–119, 2008. © 2007 Wiley‐Liss, Inc.
Association between duration of daily visual display terminal work and insomnia among local government clerks in Japan
Authors: Yoshioka Eiji , Saijo Yasuaki , Fukui Tomonori , Kawaharada Mariko , Kishi Reiko
Published: December 2007

Background

Visual display terminal (VDT) work has become very common among office workers in developed countries; however, studies investigating the association between the duration of daily VDT work and insomnia are limited.

Methods

The aim of this study was to clarify the association between the duration of daily VDT work and sleep disturbances. We investigated 2,417 clerks (men, 2,030; women, 387) at local government offices. Sleep disturbances were evaluated using the Athens Insomnia Scale (AIS).

Results

VDT work of 6 hr or more per day was significantly associated with insomnia (odds ratio = 1.62, 95% confidence interval: 1.16–2.27) and, in particular, caused problems with “total sleep duration” and “sleepiness during the day” among sleep‐related symptoms, even after adjusting for possible confounding factors.

Conclusions

Our study suggested that VDT work of 6 hr or longer per day was related to insomnia. Am. J. Ind. Med. 51:148–156, 2008. © 2007 Wiley‐Liss, Inc.
JCQ scale reliability and responsiveness to changes in manufacturing process
Authors: d'Errico Angelo , Punnett Laura , Gold Judith E. , Gore Rebecca
Published: December 2007

Background

The job content questionnaire (JCQ) was administered to automobile manufacturing workers in two interviews, 5 years apart. Between the two interviews, the company introduced substantial changes in production technology in some production areas. The aims were: (1) to describe the impact of these changes on self‐reported psychosocial exposures, and (2) to examine test–retest reliability of the JCQ scales, taking into account changes in job assignment and, for a subset of workers, physical ergonomic exposures as assessed through field observations.

Methods

The study population included 790 subjects at the first and 519 at the second interview, of whom 387 were present in both. Differences in demand and control scores between interviews were analyzed by Wilcoxon matched‐pairs signed‐rank test. Test–retest reliability of these scales was evaluated by the intraclass correlation coefficient (ICC) and the Spearman's ρ coefficient.

Results

The introduction of more automated technology produced an overall increase in job control but did not decrease psychological demand. The reliability of the control scale was low overall but increased to an acceptable level among workers who had not changed job. The demand scale had high reliability only among workers whose physical ergonomic exposures were similar on both survey occasions.

Conclusions

These results show that 5‐year test–retest reliability of self‐reported psychosocial exposures is adequate among workers whose job assignment and ergonomic exposures have remained stable over time. Am. J. Ind. Med. 51:138–147, 2008. © 2007 Wiley‐Liss, Inc.
Does APOE explain the linkage of Alzheimer's disease to chromosome 19q13?
Authors: Blom Elin S. , Holmans Peter , Arepalli Sampath , Adighibe Omanma , Hamshere Marian L. , Gatz Margaret , Pedersen Nancy L. , Bergem A. L. Mina , Owen Michael J. , Hollingworth Paul , Goate Alison , Williams Julie , Lannfelt Lars , Hardy John , Wavrant‐De Vrièze Fabienne , Glaser Anna
Published: December 2007

We have studied the impact of the apolipoprotein E gene (APOE) on the chromosome 19 linkage peak from an analysis of sib‐pairs affected by Alzheimer's disease. We genotyped 417 affected sib‐pairs (ASPs) collected in Sweden and Norway (SWE), the UK and the USA for 10 microsatellite markers on chromosome 19. The highest Zlr (3.28, chromosome‐wide P‐value 0.036) from the multipoint linkage analysis was located approximately 1 Mb from APOE, at marker D19S178. The linkage to chromosome 19 was well explained by APOE in the whole sample as well as in the UK and USA subsamples, as identity by descent (IBD) increased with the number of ε4 alleles in ASPs. There was a suggestion from the SWE subsample that linkage was higher than would be expected from APOE alone, although the test for this did not reach formal statistical significance. There was also a significant age at onset (aao) effect on linkage to chromosome 19q13 in the whole sample, which manifested itself as increased IBD sharing in relative pairs with lower mean aao. This effect was partially, although not completely, explained by APOE. The aao effect varied considerably between the different subsamples, with most of the effect coming from the UK sample. The other samples showed smaller effects in the same direction, but these were not significant. © 2007 Wiley‐Liss, Inc.
An investigation of mitochondrial haplogroups in autism
Authors: Kent Lindsey , Gallagher Louise , Elliott Hannah R. , Mowbray Catherine , Chinnery Patrick F.
Published: December 2007

Family and twin studies provide strong evidence of a major genetic influence in autism, but the underlying gene defects have yet to be characterized. The mothers of boys with autism share autistic traits, raising the possibility of a maternally inherited factor. Mitochondrial DNA (mtDNA) is almost exclusively inherited down the maternal line. We therefore explored the possibility that a particular mtDNA lineage contributes to the risk of developing autism. The mtDNA haplogroup was determined in 162 autism probands, and compared to two sets of population controls. Results show no compelling evidence of an association of any mitochondrial haplogroup in autism. © 2007 Wiley‐Liss, Inc.
Traditional nutritional analyses of figs overestimates intake of most nutrient fractions: a study of Ficus perforata consumed by howler monkeys (Alouatta palliata mexicana)
Authors: Urquiza‐Haas Tania , Serio‐Silva Juan Carlos , Hernández‐Salazar Laura Teresa
Published: December 2007

There continue to remain uncertainty concerning the nutritional importance of figs (Ficus spp.) in the primate diet. Although studies have been performed on the nutritional analysis of fig pulp and seed fractions separately, there has not been an attempt to quantify the contribution of animal matter within figs. Here we report nutritional values of figs (Ficus perforata) (Urostigma) consumed by a troop of howler monkeys (Alouatta palliata mexicana). Separate nutritional assays were performed on the pulp, seed, and animal fraction. Whole‐fig analyses significantly exaggerate the concentrations of all nutrients (lipids especially) as seeds, which represent a large proportion of the fig (45%), cannot be digested. Animal matter only represents 1% of the fig, and augments fig protein and lipid content by 0.44 and 0.30%, respectively. This represents the 11 and 9% of the fraction available for digestion. Differences in fig consumption were observed between age and sex classes (P=0.04) and periods of the day (P=0.001); females consumed more figs than males and the highest consumption of figs was observed in the afternoon. F. perforata figs may be an important component of the howler monkeys diet owing to their high content of water and calcium. Am. J. Primatol. 70:432–438, 2008. © 2007 Wiley‐Liss, Inc.
Genetic admixture, relatedness, and structure patterns among Mexican populations revealed by the Y‐chromosome
Authors: Rangel‐Villalobos H. , Muñoz‐Valle J.F. , González‐Martín A. , Gorostiza A. , Magaña M.T. , Páez‐Riberos L.A.
Published: December 2007

Y‐linked markers are suitable loci to analyze genetic diversity of human populations, offering knowledge of medical, forensic, and anthropological interest. In a population sample of 206 Mestizo males from western Mexico, we analyzed two binary loci (M3 and YAP) and six Y‐STRs, adding to the analysis data of Mexican Mestizos and Amerindians, and relevant worldwide populations. The paternal ancestry estimated in western Mexican‐Mestizos was mainly European (60–64%), followed by Amerindian (25–21%), and African (∼15%). Significant genetic heterogeneity was established between Mestizos from western (Jalisco State) and northern Mexico (Chihuahua State) compared with Mexicans from the center of the Mexican Republic (Mexico City), this attributable to higher European ancestry in western and northern than in central and southeast populations, where higher Amerindian ancestry was inferred. This genetic structure has important implications for medical and forensic purposes. Two different Pre‐Hispanic evolutionary processes were evident. In Mesoamerican region, populations presented higher migration rate (Nm = 24.76), promoting genetic homogeneity. Conversely, isolated groups from the mountains and canyons of the Western and Northern Sierra Madre (Huichols and Tarahumaras, respectively) presented a lower migration rate (Nm = 10.27) and stronger genetic differentiation processes (founder effect and/or genetic drift), constituting a Pre‐Hispanic population substructure. Additionally, Tarahumaras presented a higher frequency of Y‐chromosomes without Q3 that was explained by paternal European admixture (15%) and, more interestingly, by a distinctive Native‐American ancestry. In Purepechas, a special admixture process involving preferential integration of non‐Purepecha women in their communities could explain contrary genetic evidences (autosomal vs. Y‐chromosome) for this tribe. Am J Phys Anthropol, 2008. © 2007 Wiley‐Liss, Inc.
Alu insertion polymorphisms and an assessment of the genetic contribution of Central Asia to Anatolia with respect to the Balkans
Authors: Berkman Ceren Caner , Dinc Havva , Sekeryapan Ceran , Togan Inci
Published: December 2007

In the evolutionary history of modern humans, Anatolia acted as a bridge between the Caucasus, the Near East, and Europe. Because of its geographical location, Anatolia was subject to migrations from multiple different regions throughout time. The last, well‐known migration was the movement of Turkic speaking, nomadic groups from Central Asia. They invaded Anatolia and then the language of the region was gradually replaced by the Turkic language. In the present study, insertion frequencies of 10 Alu loci (A25 = 0.07, APO = 0.96, TPA25 = 0.44, ACE = 0.37, B65 = 0.57, PV92 = 0.18, FXIIIB = 0.52, D1 = 0.40, HS4.32 = 0.66, and HS4.69 = 0.30) have been determined in the Anatolian population. Together with the data compiled from other databases, the similarity of the Anatolian population to that of the Balkans and Central Asia has been visualized by multidimensional scaling method. Analysis suggested that, genetically, Anatolia is more closely related with the Balkan populations than to the Central Asian populations. Central Asian contribution to Anatolia with respect to the Balkans was quantified with an admixture analysis. Furthermore, the association between the Central Asian contribution and the language replacement episode was examined by comparative analysis of the Central Asian contribution to Anatolia, Azerbaijan (another Turkic speaking country) and their neighbors. In the present study, the Central Asian contribution to Anatolia was estimated as 13%. This was the lowest value among the populations analyzed. This observation may be explained by Anatolia having the lowest migrant/resident ratio at the time of migrations. Am J Phys Anthropol, 2008. © 2007 Wiley‐Liss, Inc.
Adult proportionality in small‐bodied foragers: A test of ecogeographic expectations
Authors: Kurki H.K. , Ginter J.K. , Stock J.T. , Pfeiffer S.
Published: December 2007

If predictable, ecogeographic patterning in body size and proportions of human populations can provide valuable information regarding human biology, adaptation to local environments, migration histories, and health, now and in the past. This paper evaluates the assumption that small‐bodied Later Stone Age (LSA) foragers of Southern Africa show the adult proportions that would be expected of warm‐adapted populations. Comparisons are also made with small‐bodied foragers from the Andaman Islands (AI). Indices including brachial, crural, limb element length to skeletal trunk height, and femoral head and bi‐iliac breadth to femoral length were calculated from samples of LSA (n = 124) and AI (n = 31) adult skeletons. Samples derived from the literature include those from high (Europe), middle (North Africa), and low (Sub‐Saharan Africa) latitude regions. The LSA and AI samples match some but not all expected ecogeographic patterns for their particular regions of long term habitation. For most limb length to skeletal trunk height indices the LSA and AI are most similar to the other mid‐latitude sample (North Africans). However, both groups are similar to low latitude groups in their narrow bi‐iliac breadths, and the AI display relatively long radii. Proportions of LSA and AI samples also differ from those of African pygmies. In regions like southern‐most Africa, that do not experience climatic extremes of temperature or humidity, or where small body size exists through drift or selection, body size, and proportions may also be influenced by nonclimatic variables, such as energetic efficiency. Am J Phys Anthropol, 2008. © 2007 Wiley‐Liss, Inc.
Brief Communication: Human cranial variation fits iterative founder effect model with African origin
Authors: von Cramon‐Taubadel Noreen , Lycett Stephen J.
Published: December 2007

Recent studies comparing craniometric and neutral genetic affinity matrices have concluded that, on average, human cranial variation fits a model of neutral expectation. While human craniometric and genetic data fit a model of isolation by geographic distance, it is not yet clear whether this is due to geographically mediated gene flow or human dispersal events. Recently, human genetic data have been shown to fit an iterative founder effect model of dispersal with an African origin, in line with the out‐of‐Africa replacement model for modern human origins, and Manica et al. (Nature 448 (2007) 346–349) have demonstrated that human craniometric data also fit this model. However, in contrast with the neutral model of cranial evolution suggested by previous studies, Manica et al. (2007) made the a priori assumption that cranial form has been subject to climatically driven natural selection and therefore correct for climate prior to conducting their analyses. Here we employ a modified theoretical and methodological approach to test whether human cranial variability fits the iterative founder effect model. In contrast with Manica et al. (2007) we employ size‐adjusted craniometric variables, since climatic factors such as temperature have been shown to correlate with aspects of cranial size. Despite these differences, we obtain similar results to those of Manica et al. (2007), with up to 26% of global within‐population craniometric variation being explained by geographic distance from sub‐Saharan Africa. Comparative analyses using non‐African origins do not yield significant results. The implications of these results are discussed in the light of the modern human origins debate. Am J Phys Anthropol, 2008. © 2007 Wiley‐Liss, Inc.
Stabilization of collagen by the plant polyphenolics Acacia mollissima and Terminalia chebula
Authors: Krishnamoorthy G. , Madhan B. , Sadulla S. , Rao J. Raghava , Madhulatha W.
Published: December 2007

The central role of collagen as the major structural fibrous protein in the mammalian extracellular matrix has motivated a significant effort toward the determination of its mechanical properties at all levels, ranging from single monomers and long‐chain polymers to a structural element within a biological tissue. However, the stabilization of collagen against collagenolytic degradation finds significance in biomedical and industrial applications. Tannins are plant‐derived polyphenols that have the ability to inhibit the collagenase activity at minimum concentration. The inhibitory effect of wattle (Acacia mollissima) and myrobalan (Terminalia chebula) on the action of collagenase against collagen was probed in this study. The kinetics of the inhibition of collagenase by wattle and myrobalan was deduced from the extent of hydrolysis of 2‐furanacryloyl–L‐leucyl–glycyl–L‐prolyl–L‐alanine. Both wattle and myrobalan tannin exhibited competitive modes of inhibition against collagenase. Circular dichroism studies of collagenase on treatment with wattle and myrobalan revealed changes in the secondary structure of collagenase. These results suggest that the tannins of A. mollissima and T. chebula extracts facilitated collagen stabilization through collagenase inhibition. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Phase behavior of binary and ternary blends of poly(styrene‐co‐methacrylic acid), poly(styrene‐co‐4‐vinylpyridine), and poly(2,6‐dimethyl‐1,4‐phenylene oxide)
Authors: Benabdelghani Z. , Djadoun S. , Etxeberria A. , J Iruin J. , Uriarte C.
Published: December 2007

Poly(styrene‐co‐methacrylic acid) (PSMA) and poly(styrene‐co‐4‐vinylpyridine) (PS4VP) of different compositions were prepared and characterized. The phase behavior of these copolymers as binary PSMA/PS4VP mixtures or with poly(2,6‐dimethyl‐1,4‐phenylene oxide) (PPO) as PPO/PSMA or PPO/PS4VP and PPO/PSMA/PS4VP ternary blends was investigated by differential scanning calorimetry (DSC). This study showed that PPO was miscible with PS4VP containing up to 15 mol % 4‐vinylpyridine (4VP) but immiscible with PS4VP‐30 (where the number following the hyphen refers to the percentage 4VP in the polymer) and PSMA‐20 (where the number following the hyphen refers to the percentage methacrylic acid in the polymer) over the entire composition range. To examine the morphology of the immiscible blends, scanning electron microscopy was used. Because of the hydrogen‐bonding specific interactions that occurred between the carboxylic groups of PSMA and the pyridine groups of PS4VP, chloroform solutions of PSMA‐20 and PS4VP‐15 formed interpolymer complexes. The obtained glass‐transition temperatures (Tg's) of the PSMA‐20/PS4VP‐15 complexes were found to be higher than those calculated from the additivity rule. Although, depending on the content of 4VP, the shape of the Tg of the PPO/PS4VP blends changed from concave to S‐shaped in the case of the miscible blends, two Tg were observed with each PPO/PS4VP‐30 and PPO/PS4VP‐40 blend. The thermal stability of the PSMA‐20/PS4VP‐15 interpolymer complexes was studied by thermogravimetry. On the basis of the obtained results, the phase behavior of the ternary PPO/PSMA‐20/PS4VP‐15 blends was investigated by DSC. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Study on superabsorbent composites. XVIII. Preparation, characterization, and property evaluation of poly(acrylic acid‐co‐acrylamide)/organomontmorillonite/sodium humate superabsorbent composites
Authors: Zheng Yian , Wang Aiqin
Published: December 2007

A series of novel multifunctional poly (acrylic acid‐co‐acrylamide) (PAA‐AM)/organomontmorillonite (O‐MMT)/sodium humate (SH) superabsorbent composites were synthesized by the graft copolymerization reaction of partially neutralized acrylic acid and acrylamide on O‐MMT micropowder and SH with N,N′‐methylene bisacrylamide as a crosslinker and ammonium persulfate as an initiator in an aqueous solution. The superabsorbent composites were characterized by means of Fourier transform infrared spectroscopy, X‐ray diffraction, scanning electron microscopy, and thermogravimetric analysis. The effect of the relative weight ratio of SH to O‐MMT on the water absorbency was studied, and the results indicated that the best water absorbency of 591 g/g in distilled water was obtained when an O‐MMT content of 20 wt % and an SH content of 30 wt % were incorporated. The superabsorbent composite possessed a good capacity for water retention; even after 30 days, 24.4 wt % of water could still be saved by the sand soil containing 1.0 wt % superabsorbent composite. The results from this study show that the water absorbency of a superabsorbent composite is improved by the simultaneous introduction of O‐MMT and SH into a PAA‐AM network in comparison with the incorporation of only O‐MMT or SH. Also, in comparison with PAA‐AM/MMT/SH, an appropriate amount of O‐MMT can benefit the developed composites with respect to their water absorbency, salt resistance, and capacity for water retention in sand soil. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Aqueous dispersion polymerization of acrylamide with quaternary ammonium cationic comonomer
Authors: Wu Y. M. , Chen Q. F. , Xu J. , Bi J. M.
Published: December 2007

Using aqueous solution of ammonium sulfate as medium, acrylamide (AM) and dimethylaminoethyl methacrylate methyl chloride (DMC) as main raw materials, poly(dimethylaminoethyl methacrylate methyl chloride) (PDMC) as stabilizer and 2,2′‐azobis (2‐amidinopropane) dihydrochloride (V‐50) as initiator, the cationic polyelectrolyte of P(DMC‐AM) was synthesized by aqueous dispersion polymerization. The effects of the major reaction variables on synthesis conditions, product characteristics (particle size and molecular weight), and polymerization rate were investigated. The polymerization was retarded by the presence of the ammonium sulfate. The optimum reaction conditions for obtaining a stable aqueous dispersion were concentrations of 1.8 × 10−4–7.0 × 10−4mol L−1for V‐50, 1.5–3.5% for stabilizer, and 23.2–30.0% for salt. The molecular weight of PDMC formed was 1.5 × 105to 7.0 × 105. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Preparation of porous PVdF membrane via thermally induced phase separation using sulfolane
Authors: Cui Zhen‐Yu , Du Chun‐Hui , Xu You‐Yi , Ji Gen‐Liang , Zhu Bao‐Ku
Published: December 2007

Sulfolane was acted as a kind of diluent to prepared PVdF porous membranes via TIPS process. Its impact on structure and morphology was studied. Phase diagram for this system was determined by different scanning calorimetry (DSC). Not any structure in the region higher than the dynamic crystallization temperature can be found and the temperature at which particle formation was observed by the optical microscope was approximately in agreement with the dynamic crystallization temperature, which revealed that only S–L phase separation happened for PVdF/sulfolane system during TIPS process. It was found that the heat of crystallization increased with the increase of polymer content. The increase of the cooling rate will increase the crystallization rate. SEM, which showed that membranes had symmetrical structure and pores formed between PVdF crystallization, revealed that PVdF will present different crystallization morphology as the cooling rate changed. With the cooling rate decrease, both the size of particles and the channel size of open pores between particles became larger, but more uneven. As the cooling rate increased, the size of particles decreased and pore became well interconnected and uniform, which were confirmed by the measurement of average pore size and pore size distribution. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Unsymmetrical α‐diimine nickel (II) complex with rigid bicyclic ring ligand: Synthesis, characterization, and ethylene polymerization in the presence of AlEt2Cl
Authors: Li Ting , Zhang Chuan Hui , Zhu Fang Ming , Wu Qing
Published: December 2007

Unsymmetrical α‐diimine ligand 1 was successfully synthesized via condensation of trimethylaluminum (TMA) metalated 2‐methyl‐6‐isopropyl‐aniline with rigid bicyclic aliphatic diketone camphorquinone. Syn‐ and anti‐stereoisomers were detected by 13C NMR in the condensation product. The corresponding α‐diimine nickel (II) complex 1 was prepared from the exchange reaction of (DME)NiBr2 with the ligand 1, and displayed high activity for ethylene polymerization in the presence of diethylaluminum chloride (AlEt2Cl). The resultant polymers were confirmed by gel permeation chromatography and 13C NMR characterization to be broad molecular weight distribution polyethylene with various branches, and high degree of branching, even at low polymerization temperature −10°C. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis of novel moisture‐curable polyurethanes end‐capped with alkoxysilane and use as solvent‐free elastic adhesives
Authors: Nomura Yukihiro , Sato Akihiro , Sato Shinichi , Mori Hideharu , Endo Takeshi
Published: December 2007

Novel silane endcappers and novel polyurethanes end‐capped with alkoxysilane (silylated polyurethanes) were developed as moisture‐curable materials, in which curing reaction occurs under humid conditions in the presence of dioctyltin diversatate as a curing catalyst. Two secondary amine‐terminated alkoxysilane compounds (silane endcappers) were synthesized by Michael addition reaction of commercially available N‐(2‐aminoethyl)‐3‐aminopropyltrimethoxysilane (or N‐(2‐aminoethyl)‐3‐aminopropylmthyldimethoxysilane) with methyl acrylate. The resulting silane endcappers were utilized to end‐capped isocyanate‐terminated polyurethanes, providing the silylated polyurethanes. The physical properties of the moisture‐curable silylated polyurethanes derived from several polyols and the silane endcappers were evaluated in terms of 50% modulus, tensile strength at break, elongation at break, and Shore A hardness after curing. The longer main chain of the silylated polyurethanes led to the lower Shore A hardness, the lower 50% modulus, and the longer elongation at break. In contrast, the tensile strengths at break were almost the same for all silylated polyurethanes, irrespective of the length of the main chain and the structure of the terminal silyl group. The silylated polyurethanes were employed for the preparation of novel solvent‐free moisture‐curable elastic adhesives, which were evaluated at the tensile shear bond strength. No significant influence of the molecular weight of the polyols and silane endcappers was observed on the tensile shear bond strength. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Thermally stable polyurethane‐ureas and copolyurethane‐ureas containing zinc and nickel dihydroxysaltrien complexes
Authors: Khamma Nittaya , Krisiri Datchanee , Tachaprasertporn Prakaywan , Chantarasiri Nuanphun
Published: December 2007

New 4,4′‐dihydroxysaltrien metal complexes, (MOHSal2trien, where M = Zn and Ni) were synthesized and used for the synthesis of metal‐containing polyurethane‐ureas and copolyurethane‐ureas. MOHSal2trien underwent polymerization reaction with two diisocyanates, namely 4,4′‐diphenylmethane diisocyanate (MDI) and isophorone diisocyanate (IPDI) to yield polyurethane‐ureas. Copolyurethane‐ureas were synthesized by the reaction between MOHSal2trien, MDI, and diamines or dialcohols. The diamines or dialcohols employed were 4,4′‐methylenedianiline (MDA), hexamethylenediamine (HMA), bisphenol A (BPO), and hexamethylene glycol (HMO). The polymers were characterized by IR, NMR, elemental analysis, XRD, solubility, and viscosity. Thermal stability and flammability of polymers were studied by thermogravimetric analysis (TGA) in air and by measuring limiting oxygen index (LOI) values, respectively. It was found that the resulting metal‐containing polyurethane‐ureas and copolyurethane‐ureas exhibited good thermal stability. Among all metal‐containing polyurethane‐ureas, NiOHSal2trien‐MDI was the most thermally stable polymer with char yield of 55% at 600°C. Solubility in DMSO of zinc‐containing copolyurethane‐ureas based on dialcohols was greatly improved when compared with those of zinc‐ and nickel‐containing polyurethane‐ureas. ZnOHSal2trien‐MDI‐BPO and ZnOHSal2trien‐MDI‐HMO gave high char yield of 46% at 600°C, which is almost comparable with that of NiOHSal2trien‐MDI. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Effects and optimization of processing parameters in water‐assisted injection molding
Authors: Huang Han‐Xiong , Deng Zhi‐Wu
Published: December 2007

Experiments of water‐assisted injection molded polypropylene curved pipe were carried out on newly developed equipment in this lab. First, four processing parameters, including short‐shot size, melt temperature, water injection delay time, and water pressure, were investigated in terms of their effects on the water penetration length and residual wall thickness of curved pipe. Second, an orthogonal array of Taguchi, the S/N ratio, and ANOVA were utilized to find the optimal processing parameters resulting in maximum water penetration length. Finally, the crystallization behavior difference between the beginning and the end of the water channel of the curved pipe was analyzed using differential scanning calorimetry. It was interesting to find that the crystallinity of sample from the middle is higher than those from both outer and inner layers at position near the water inlet. The samples taken from the outer layer, middle, and inner layer show similar melting peak and crystallinity at position near the end of water channel. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Fluid biomulching based on poly(vinyl alcohol) and fillers from renewable resources
Authors: Chiellini E. , Cinelli P. , Magni S. , Miele S. , Palla C.
Published: December 2007

This article reports on the results obtained in an investigation on the application of biodegradable polymeric materials in the agricultural practice of mulching. Particular attention has been devoted to the effect of biobased mulching films generated in situ by low‐pressure spraying of polymeric water dispersions on the various cultivars. In a field trial, the effectiveness of the hydromulching (liquid‐mulching) technique was assessed by the monitoring of the growth and yield of lettuce and corn, which were used as reference plants. Conventional plastic films and straw mulching (SM) were compared with liquid‐mulching treatments based on poly(vinyl alcohol) and natural fillers derived from agroindustrial wastes (sugar cane bagasse, wheat flour, saw dust, and wheat straw). An improvement of the biomass yield of the two selected plants with respect to conventional polyethylene mulching was attained in various liquid‐mulching formulations with positive effects on the maintenance of soil structure. Alternative fluid‐mulching treatments based on biodegradable components were effective in preserving soil aggregates and improving some crop growth parameters. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Use of input selection techniques to improve the performance of an artificial neural network during the prediction of yarn quality properties
Authors: Mwasiagi Josphat Igadwa , Wang Xin Hou , Huang Xiu Bao
Published: December 2007

The performance of an artificial neural network (ANN) is affected by the number and types of inputs. The aim of this article is to study the performance of ANN algorithms, used for the prediction of cotton yarn strength, elongation, and evenness, as the input units are subtracted (skeletonized) and added to the input layer. Nineteen factors, consisting of fiber properties, processing parameters, and yarn quality properties, were used as the main source of inputs. The initial sets of inputs, which were selected on the basis of their relationship with the output factors, were 13, 13, and 12 for yarn strength, elongation, and evenness, respectively. The final sets of inputs were 14 factors for the three yarn quality properties being predicted, and the new ANN algorithms showed performance improvement of 40, 37, and 47% for strength, elongation, and evenness, respectively, when compared to the algorithms with 19 factors. Yarn twist, fiber length, and fiber length uniformity were common among the five most influential factors affecting yarn strength, elongation, and evenness, accounting for 40, 37, and 37% for the prediction of yarn strength, elongation, and evenness, respectively. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
In situ fibrous structure oriented polymer blends composed of poly(lactic acid) and polycaprolactone containing peroxide
Authors: Semba Takeshi , Kitagawa Kazuo , Kotaki Masaya , Hamada Hiroyuki
Published: December 2007

A fibrous dispersed phase stuffed with polycaprolactone (PCL) was constructed in a poly(lactic acid) (PLA) matrix during an injection‐molding process. The injection‐molding process showed efficiency in forming dispersions with fibrous shapes, and they could impart the ductile property of PCL to the brittle PLA matrix, with appropriate interfacial adhesion arising from the cocrosslinking structure at the PLA/PCL interface by dicumyl peroxide (DCP). However, the addition of excess DCP caused a split of the dispersions resulting from the compatibility increment and the excess crosslinking reaction at the interface and inside each phase. The addition of a small amount of DCP could adhere the interface without splitting of the dispersions. The observed internal structure in the injection moldings showed a morphology transition that changed gradually from a fine fibrous morphology to a coarse morphology at a deeper position in the injection moldings. The tensile properties of sliced local layers, which were fabricated with a sliding microtome, proved that the fibrous morphology was effective in the improvement of ductility of the blends. An X‐ray analysis showed that the shear flow increased the crystalline orientation and formed a different crystalline structure only in the PCL dispersed phase, but its crystalline structure was not the main factor for ductility improvement. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Viscosity behavior of microwave‐heated and conventionally heated poly(ether sulfone)/dimethylformamide/lithium bromide polymer solutions
Authors: Idris Ani , Ahmed Iqbal
Published: December 2007

This article investigates the viscosity behavior of new membrane dope solutions of poly(ether sulfone) (PES) and dimethylformamide with low‐molecular‐weight halogenated lithium bromide (LiBr) additives prepared with two different techniques: (1) a microwave (MW) technique and (2) a conventional heating (CH) technique. In addition, the influence of different concentrations of anhydrous halogenated LiBr additives (0–5 wt %) on the viscosity behavior is analyzed. The viscosity of the dope solutions was assessed with a conical rheometer equipped with a high‐viscosity adapter. The results revealed that the pure PES solutions prepared by the MW and CH techniques exhibited pseudoplastic and Newtonian behavior, respectively. Both the MW and CH PES solutions containing the LiBr additives exhibited dilatant behavior, which obeyed the power law. The apparent viscosity of all the dope solutions prepared with the MW technique was lower than that of those prepared with the CH technique. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Effect of UV‐photocrosslinking on the nonisothermal crystallization kinetics of polyethylene
Authors: Tang Longxiang , Yan Manqing , Liu Chunhua , Wang Pinghua , Qu Baojun
Published: December 2007

The influences of UV‐photocrosslinking on crystallite structure and nonisothermal crystallization kinetics of polyethylene (PE) were investigated by optical microscope (OM) and differential scanning calorimetry (DSC) at different cooling rates, respectively. The observation of crystallite structure showed that, due to crosslinking of molecular chains of PE, the PE spherulites grow more imperfectly with increasing gel content. The Avrami analysis modified by Jeziorny was applied to describe the nonisothermal crystallization process of virgin PE and photocrosslinked PE (XLPE) samples. The values of half‐time of crystallization t1/2 and the parameter Zc showed that the crystallization rate increased with increasing cooling rates for both XLPE and virgin PE, but the crystallization rate of XLPE is lower than that of virgin PE at the same cooling rate. The activation energies were estimated by the Kissinger method, and the values were 176.7 and 197.1 kJ/mol for virgin PE and XLPE, respectively, indicating that UV‐photocrosslinking might hinder the overall nonisothermal crystallization process of PE. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Grafting polymer from poly(ethylene terephthalate) films by surface‐initiated ATRP
Authors: Zhang Hongwen , Shouro Daisuke , Itoh Koichi , Takata Tadahiko , Jiang Yan
Published: December 2007

Surface‐initiated atom transfer radical polymerization (ATRP) from poly(ethylene terephthalate) (PET) film was studied. Poly(methyl methacrylate) (PMMA), poly (acrylamide) (PAAM), and their diblock copolymer (PMMA/PAAM) on the surface of PET film were successfully prepared by surface‐initiated ATRP. The structures and properties of the modified PET film were characterized by FT‐IR/ATR, X‐ray photoelectron spectroscopy (XPS), measurements of contact angles, and scanning electronic microscopy (SEM). The results indicate that the surface properties of PET film were greatly improved by grafted polymer. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Oxidative radical generation via nitrogen dioxide dimer conversions induced by amide groups of macromolecules
Authors: Davydov E. Ya. , Gaponova I. S. , Pokholok T. V. , Pariiskii G. B. , Zaikov G. E.
Published: December 2007

The features of initiation of free radical reactions in polymers by dimers of nitrogen dioxide are considered. The conversion of planar dimers into nitrosyl nitrate in the presence of amide groups of macromolecules has been revealed. Nitrosyl nitrate initiates radical reactions in oxidative primary process of electron transfer with formation of intermediate radical cations and nitric oxide. As a result of subsequent reactions, nitrogen‐containing radicals are produced. The dimer conversion has been exhibited by estimation of the oxyaminoxyl radical yield in characteristic reaction of p‐benzoquinone with nitrogen dioxide on addition of aromatic polyamide and polyvinylpyrrolidone to reacting system. The isomerization of planar dimers is efficient in their complexes with amide groups, as confirmed by ab initio calculations. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Preparation, morphology, and physical properties of transparent PSt hybrid materials containing silicone macromonomer
Authors: Daimatsu Kazuki , Anno Yusuke , Sugimoto Hideki , Nakanishi Eiji , Inomata Katsuhiro , Ikeda Tomoki , Yokoi Kazuki
Published: December 2007

The aim of this study was to prepare transparent polystyrene (PSt) hybrid materials containing silicone macromonomer. Silicone urethane methacrylate (SiUMA) was synthesized by the reaction between the hydroxyl end groups of a silicone macromonomer and the isocyanate group of 2‐methacryloyloxyethyl isocyanate (MOI), and copolymers with different weight proportions were prepared by copolymerization of styrene (St), SiUMA and ethyleneglycol dimethacrylate (EGDMA). Though the prepared P(St‐co‐SiUMA) copolymers which had not introduced EGDMA were opaque, the prepared P(St‐co‐SiUMA‐co‐EGDMA) copolymers were transparent, similarly to pure PSt. DSC and 1H‐NMR measurements were carried out to investigate the factors in this transparency in detail. From these measurement results, it was confirmed that the reactivity of the copolymerization had a significant influence on the transparency of the product. In addition, the contact angle of P(St‐co‐SiUMA‐co‐EGDMA) with 10 wt % SiUMA was greater than 90°, which was a 10° improvement compared to pure PSt. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008