bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quality of parental relationships among persons with a lifetime history of posttraumatic stress disorder
Authors: Lauterbach Dean , Bak Christina , Reiland Sarah , Mason Shawn , Lute Michael R. , Earls Lauren 
Published: April 2007

AbstractSeveral studies of combat veterans have examined the relationship between parental satisfaction and PTSD symptoms. These studies found that numbing is associated with substantial decrements in parent–child relationship quality. The current study extends previous work by assessing the effect of PTSD on parent–child relationships in a nationally representative sample of civilian men and women with PTSD resulting from a broad range of trauma. It was hypothesized that PTSD avoidance/numbing symptoms would be predictive of parent–child relationship quality and parent–child conflict. Moreover, these relationships are predicted to hold after controlling for a broad range of support‐related variables and work/finance related variables. As hypothesized, after controlling for number of children and respondent‐initiated domestic violence, numbing was predictive of increased parent–child aggression.
Confirmatory factor analysis of posttraumatic stress symptoms in cambodian refugees
Authors: Palmieri Patrick A. , Marshall Grant N. , Schell Terry L. 
Published: April 2007

AbstractThis study used confirmatory factor analysis to examine the factor structure of the Cambodian version of the Harvard Trauma Questionnaire in 488 Cambodian refugees residing in the United States. Five alternative conceptual models were compared. A model with four correlated factors reflecting symptoms of reexperiencing, avoidance, emotional numbing, and hyperarousal provided the best fit to these data. The avoidance and emotional numbing clusters demonstrated distinct associations with depression symptoms, providing some evidence of the construct validity of the four‐factor solution.
Intrusive memories and ruminations related to violent crime among young offenders: Phenomenological characteristics
Authors: Evans Ceri , Ehlers Anke , Mezey Gillian , Clark David M. 
Published: April 2007

AbstractVery little is known about the nature of perpetrator's memories of violent crime. The authors conducted semistructured interviews with a representative sample of 105 young offenders convicted of serious violence, assessing intrusive memories, ruminations, and symptoms of posttraumatic stress disorder related to their violent crime. Forty‐eight (46%) participants described significant intrusive memories of the assault, and 38 (36%) reported ruminations related to the assault. Ethnic origin and historical variables explained 19% of the variance of posttraumatic stress disorder symptom severity; intrusion and rumination characteristics added an additional 48% explained variance. The intrusive memories tended to concern the moment when the event turned for the worse for the perpetrator. The findings have implications for risk assessment and therapeutic interventions for violent offenders.
The criterion a problem revisited: Controversies and challenges in defining and measuring psychological trauma
Authors: Weathers Frank W. , Keane Terence M. 
Published: April 2007

AbstractThe Criterion A problem in the field of traumatic stress refers to the stressor criterion for posttraumatic stress disorder (PTSD) and involves a number of fundamental issues regarding the definition and measurement of psychological trauma. These issues first emerged with the introduction of PTSD as a diagnostic category in the Diagnostic and Statistical Manual of Mental Disorders, Third Edition (DSM‐III; American Psychiatric Association, 1980) and continue to generate considerable controversy. In this article, the authors provide an update on the Criterion A problem, with particular emphasis on the evolution of the DSM definition of the stressor criterion and the ongoing debate regarding broad versus narrow conceptualizations of traumatic events.
Hydration Characterization of Hydrophobically Modified Polymers by Dielectric Measurements in the Millimeter Range
Authors: Vorob'ev Mikhail , Churochkina Natalia , Khokhlov Alexei , Stepnova Evgenia 
Published: April 2007

AbstractBound water molecules, the fraction of water molecules that are present in the hydration shells of polymers, lose their rotational mobility in the time scale of 10–50 ps, leading to additional ordering compared with unperturbed water. The amount of bound water per number of carbons in the nonpolar groups as measured by the method of waveguide dielectric resonance increased in the following order: hydrophobically modified chitosan < globular protein < hydrophobically modified polyacrylamide. The hydrophobic modification of acrylamide and chitosan polymers gave smaller variation in hydration than did both the coil‐to‐globule transition of poly(N‐isopropylacrylamide) and the masking of nonpolar groups within the protein globule.magnified image
Efficient Modification on PLLA by Ozone Treatment for Biomedical Applications
Authors: Ho Ming‐Hua , Lee Juin‐Jay , Fan Shu‐Chin , Wang Da‐Ming , Hou Lein‐Tuan , Hsieh Hsyue‐Jen , Lai Juin‐Yih 
Published: April 2007

AbstractRGDS (Arg‐Gly‐Asp‐Ser) is immobilized on poly(L‐lactic acid) (PLLA) with ozone oxidation and the addition of an intermediate reactant, acryl succinimide (ASI) to promote the grafting efficiency. A DPPH (2,2‐di(4‐tert‐octylphenyl)‐1‐picrylhydrazyl) assay has revealed that the peroxide concentration can be controlled by adjusting the ozone treatment time. The immobilization of ASI is verified by elemental analysis. The peptide concentrations are in the effective order, as shown by means of high performance liquid chromatography (HPLC), and the grafting efficiency is proven to be relatively high compared with the previous studies. The culture of rat osteosarcoma 17/2.8 (ROS), osteoblastic‐like cells, demonstrates that the grafting of RGDS can enhance the attachment and osteogenesis of ROS cells on PLLA. With the addition of ASI, the cultured ROS cells express normal function in proliferation and mineralization. From in vivo experiments, ASI immobilized on the surface is shown to be biocompatible. These results lead to the conclusion that the ozone treatment with the intermediate reactant ASI is an efficient, biocompatible, and easily controllable procedure to modify PLLA. Furthermore, the immobilization of RGDS in significant amounts following the ozone oxidation could further promote the biocompatibility and the osteoinduction of PLLA.magnified image
Cell Migration Rate on Poly(ε‐caprolactone)/Poly(ethylene glycol) Diblock Copolymers and Correlation with the Material Sliding Angle
Authors: Hsu Shan‐hui , Tang Cheng‐Ming , Chiu Jeng‐Jiann , Liao Tien‐Chi , Lin Chu‐Chieh , Iwata Hiroo 
Published: April 2007

AbstractThe nanostructure of a biomaterial surface has strong influence on cell behavior. The migration of cells on nanostructured surfaces, however, has not been investigated so far. In this study, we used PCL/PEG diblock copolymers as model surfaces to examine the effect of nanoislands on migration of different cells, including fibroblasts and endothelial cells. The water sliding angle of the substrates was measured. The cell migration rate was examined under a real‐time optical microscope. It was found that a greater cell migration rate correlated with the smaller sliding angle of the substrate.magnified image
Homogeneous Tritylation of Cellulose in 1‐Butyl‐3‐methylimidazolium Chloride
Authors: Erdmenger Tina , Haensch Claudia , Hoogenboom Richard , Schubert Ulrich S. 
Published: April 2007

Abstract1‐Alkyl‐3‐methylimidazolium‐based ionic liquids, having chloride as a counter ion, were studied for cellulose solubility; and the influence of different alkyl chain lengths was also investigated. The alkyl chain length was incrementally varied from ethyl to decyl to determine structure‐dissolution properties; a distinct odd‐even effect was observed for short chain lengths. In addition, the tritylation of cellulose was performed in 1‐butyl‐3‐methylimidazolium chloride using pyridine as base. The influences of reaction time and the ratio of trityl chloride per cellulose monomer unit on the degree of substitution were investigated in detail by elemental analysis and 1H NMR spectroscopy. A DS of around 1 was obtained after 3 h reaction time using a six fold excess of trityl chloride.magnified image
In Vivo Evaluation of a Biodegradable EDC/NHS‐Cross‐Linked Gelatin Peripheral Nerve Guide Conduit Material
Authors: Chang Ju‐Ying , Lin Jia‐Horng , Yao Chun‐Hsu , Chen Jiunn‐Horng , Lai Tung‐Yuan , Chen Yueh‐Sheng 
Published: April 2007

AbstractPeripheral nerve regeneration has been evaluated using a biodegradable nerve conduit, which is made of a 1‐ethyl‐3‐(3‐dimethylaminopropyl)carbodiimide (EDC)/N‐hydroxysuccinimide (NHS) cross‐linked gelatin. The EDC/NHS crosslinked gelatin (ENG) conduit is brownish in appearance, and is concentric and round with a smooth outer surface and inner lumen. After subcutaneous implantation on the dorsal side of a rat, the degraded ENG conduit only evoked a mild tissue response, with the formation of a thin tissue capsule surrounding the conduit. Biodegradability of the ENG conduit and its effectiveness as a guidance channel has been examined by its use to repair a 10 mm gap in the rat sciatic nerve. As a result, the tubes degraded throughout the implantation period, but still remained circular with a thin round lumen until they were completely integrated with the enclosed nerves. Successful regeneration through the gap occurred in all the conduits over the three experimental periods of 4, 8, and 12 weeks. Histological observation showed that numerous myelinated axons had crossed through the gap region even at the shortest implantation period of 4 weeks. Peak amplitude, area under the muscle action potential curve, and nerve conductive velocity all showed an increase as a function of the recovery period, which indicates that the nerve had undergone adequate regeneration. These results indicate the superiority of the ENG materials and suggest that the novel ENG conduits provide a promising tool for neuro‐regeneration.magnified image
Synthesis and Characterization of Degradable p(HEMA) Microgels: Use of Acid‐Labile Crosslinkers
Authors: Bulmus Volga , Chan Yannie , Nguyen Quyen , Tran Hong L. 
Published: April 2007

AbstractNew divinyl‐functionalized acetal‐based crosslinkers were synthesized as building elements to form acid‐labile microgel particles for controlled‐release applications. The synthesized crosslinkers underwent hydrolysis at slightly acidic pHs in less than 1 h while they were stable at neutral pHs for longer times. HEMA was copolymerized with the crosslinkers via an inverse emulsion polymerization technique using a redox initiator system at room temperature to form crosslinked, colloidal p(HEMA) microgels. Microgels in diameters ranging from 150 to 475 nm with narrow distribution could be produced. The crosslinking density and the diameter of the microgels were found to be controlled by monomer/crosslinker feed ratio. The microgels demonstrated a pH‐dependent cleavage behavior that mimicked the pH‐dependent hydrolysis profile of the acid‐labile crosslinkers. Model biomacromolecules, i.e., Rhodamine B‐labeled dextran and BSA were efficiently loaded into the microgels. The release of the biomolecules from p(HEMA) microgels was also found to be controllable by the pH of the environment similar to the particle degradation. The protein released from the microgels was observed to retain its structural stability.magnified image
Poly(ε‐caprolactone)–Poly(oxyethylene) Multiblock Copolymers Bearing Along the Chain Regularly Spaced Pendant Amino Groups
Authors: Canciello Mariarosaria , Maglio Giovanni , Nese Giuseppe , Palumbo Rosario 
Published: April 2007

AbstractPoly(ε‐caprolactone) (PCL) macromers ($\overline M _{\rm n} $ = 1.7–3.8 kDa) which contain one Z‐protected NH2 group per chain were synthesized by ring‐opening polymerization of ε‐caprolactone in the presence of Sn(oct)2 using as initiator a diamine prepared by condensation of N‐Boc‐1,6‐hexanediamine and Nα‐Boc‐Nε‐Z‐L‐Lysine. The coupling of these macromers with COCl end‐capped poly(oxyethylene) (PEO), $\overline M _{\rm n} $ = 1.0 kDa, afforded amphiphilic multiblock poly(ether ester)s (PEEs) which have, along the chain, regularly spaced pendant protected amino groups. Deprotection, accomplished without chain degradation, yielded NH2 groups available for further reactions. The molecular structure of macromers and PEEs was investigated by 1H NMR and SEC. DSC and WAXS analyses showed that macromers and copolymers were semicrystalline and their Tm increased with increase in the molecular weight of PCL segments. The inherent viscosity values (0.25–0.30 dL · g−1), together with SEC analysis results, indicated moderate polymerization degrees.magnified image
ATPase‐Coupled Release Control from Polyion Complex Capsules Encapsulating Muscle Proteins
Authors: Sugiura Kousuke , Ohkawa Kousaku , Hirai Toshihiro , Fujii Toshihiro 
Published: April 2007

AbstractIn the present study, a muscle contractile protein complex, actomyosin, has been successfully encapsulated into gellan–chitosan polyion complex (PIC) capsules. The recovery of the myosin‐ATPase activity is approximately 50% and the Mg2+‐ATPase activity is stimulated by the presence of F‐actin, which implies the formation of the actomyosin complex inside the capsule. Furthermore, encapsulation could protect the myosin, F‐actin, and actomyosin inside from hydrolysis by proteases. Two small proteins, myoglobin and cytochrome c, have been used in the release tests. The release of myoglobin is not affected by the ionic strength of the external solution, while the release of cytochrome c increases with increasing ionic strength. The maximal releases are found in the external pH solution close to the isoelectric points of each protein. The Mg2+‐ATP complex itself reduces the release percentages of the small proteins from the PIC capsule. The release amounts further decrease when coexisting with Mg2+‐ATP and the encapsulated actomyosin, which indicates the release regulation by actomyosin. The present study suggests that the ATPase‐coupled sliding motion of the myosin–F‐actin filaments modifies the pore size of the polymer networks in the PIC capsule membranes.magnified image
All‐Dry Synthesis and Coating of Methacrylic Acid Copolymers for Controlled Release
Authors: Lau Kenneth K. S. , Gleason Karen K. 
Published: April 2007

AbstractInitiated chemical vapor deposition (iCVD) is presented as an all‐dry synthesis and coating method for applying methacrylic acid copolymers as pH‐responsive controlled release layers. iCVD combines the strengths of liquid‐phase chemical synthesis with a precision solvent‐free chemical vapor deposition environment. Copolymers of methacrylic acid and ethyl acrylate were confirmed by a systematic shift in the carbonyl bond stretching mode with a shift in the comonomer ratio within the copolymer and by the ability to apply the Fineman–Ross copolymerization equation to describe copolymerization kinetics. Copolymers of methacrylic acid and ethylene dimethacrylate showed pH‐dependent swelling behavior that was applied to the enteric release of fluorescein and ibuprofen.magnified image
Uniform Biodegradable Hydrogel Microspheres Fabricated by a Surfactant‐Free Electric‐Field‐Assisted Method
Authors: Choy Young Bin , Choi Hyungsoo , Kim Kyekyoon (Kevin) 
Published: April 2007

AbstractUniform biodegradable hydrogel microspheres (HMS) with precisely controlled size have been fabricated using an electric‐field‐assisted precision particle fabrication technique. Particle agglomeration was prevented by charging the hydrogel drops and allowing Coulomb repulsion to separate them. As a result, surfactant‐free and non‐toxic particle fabrication was possible and the resulting microspheres were most suitable for biomedical and food‐related applications. Due to the size uniformity, the present HMS may serve as a convenient yet most accurate vehicle for controlled delivery of therapeutic agents and other active ingredients.magnified image
Ferrocene Branched Chitosan for the Construction of a Reagentless Amperometric Hydrogen Peroxide Biosensor
Authors: Garcia Ariel , Peniche‐Covas Carlos , Chico Belkis , Simpson Benjamin K. , Villalonga Reynaldo 
Published: April 2007

AbstractChitosan was chemically branched with ferrocene moieties and further used as a support for the immobilization of horseradish peroxidase on a glassy carbon electrode. The reagentless biosensor device showed a linear amperometric response toward hydrogen peroxide concentrations between 35 × 10−6 M and 2.0 × 10−3 M. The biosensor reached 95% of the steady‐state current in about 20 s and its sensitivity was 28.4 × 10−3 µA · M−1. The enzyme electrode retained 94% of its initial activity after 2 weeks of storage at 4 °C in 50 × 10−3 M sodium phosphate buffer at pH 7.0.magnified image
Thermal Behavior of Isotactic Poly(propylene)/Maleated Poly(propylene) Blends
Authors: Vîlcu Catalin , Grigoras Cristian , Vasile Cornelia 
Published: April 2007

AbstractThis paper analyzes the thermal and thermo‐oxidative degradation behavior, phase separation, melting, and crystallization of blends consisting of isotactic poly(propylene) (IPP) and poly(propylene) grafted with maleic anhydride (PP‐g‐MA). It has been established that, depending on the blend composition and crystallization/preparation procedure, the blends of IPP and PP‐g‐MA can either co‐crystallize or evidence phase separation. This conclusion has been attained by comparing the DSC results of crystallization under dynamic and isothermal conditions with X‐ray diffraction results. On the basis of the obtained results, the optimum mixing ratios have been established as 95–85 wt.‐% IPP/5–15 wt.‐% PP‐g‐MA. Thermo‐oxidative behavior has been studied by thermogravimetry and differential thermal analysis.magnified image
Effect of Ultrasonic Dispersion Methods on Thermal and Mechanical Properties of Organoclay Epoxy Nanocomposites
Authors: Dean Katherine , Krstina Julia , Tian Wendy , Varley Russell J. 
Published: April 2007

AbstractThis report highlights the importance of nanocomposite formation and dispersion upon improvements in properties for high performance epoxy based layered silicate nanocomposites. This is achieved through the preparation of epoxy nanocomposites with varying clay concentrations using ultrasonic and solvent based fabrication and standard shear mixing procedures. Ultrasonication (combined with a solvent), in comparison to shear mixing methods, produces superior nanoscale dispersion according to SEM and TEM. As a result of the improvements in nanoscale dispersion, the corresponding improvements in fracture toughness, strength, strain to failure (compressive and flexural) and char stability are presented. TGA shows that while the initial thermal decomposition process is not affected, the stability of the char layer formed during decomposition increases with improved nanoscale dispersion as well as increasing concentration. The effect of moisture upon the dynamic mechanical thermal analysis of the epoxy nanocomposites displays some dependence upon the clay dispersion with a modest increase in plasticisation for the sonicated samples. Overall, this work shows that for a high performance epoxy anhydride resin system, significant improvements in key properties can be achieved at low levels of addition if appropriate sonicated dispersion methods can be utilised.magnified image
The Effects of Different Plasticizers on the Properties of Thermoplastic Starch as Solid Polymer Electrolytes
Authors: Ma Xiaofei , Yu Jiugao , He Kang , Wang Ning 
Published: April 2007

AbstractPlasticizers with amide groups (urea and formamide) and polyols (glycerol, glucose, and sorbitol) were used to prepare thermoplastic starch (TPS) containing NaCl salt as solid polymer electrolytes (SPE). Fourier Transform infrared (FT‐IR) spectroscopy revealed that both plasticizers and Na+ could form the interaction with starch, and plasticizers containing amide groups had stronger hydrogen bond‐forming abilities with starch than polyols. These interactions prevented starch molecules from crystallizing again, indicated by X‐ray diffraction (XRD). Scanning electron microscope (SEM) showed that starch granules were in a molten state and a continuous phase of TPS was formed. Among TPS as SPE, formamide‐plasticized TPS (FPTPS) had the largest elongation at break and lowest tensile stress. The conductance of TPS was sensitive to water. TPS plasticized by solid plasticizers had the higher sensitivity of the conductance to water contents at the low water contents (<0.1). The relationship of the conductance and water contents was in agreement with the second‐order polynomial correlation when water contents were below 0.45. FPTPS had the best conductance as a whole. At the medium water content (0.2), the conductance of FPTPS containing NaCl was about 10−3 S · cm−1.magnified image
A High‐Throughput, Controllable, and Environmentally Benign Fabrication Process of Thermoplastic Nanofibers
Authors: Wang Dong , Sun Gang , Chiou Bor‐Sen 
Published: April 2007

AbstractContinuous and uniform yarns of thermoplastic nanofibers were prepared via direct melt extrusion of immiscible blends of thermoplastic polymers with CAB and subsequent extraction removal of CAB. Ratios of thermoplastic/sacrificial polymers, melt viscosity, and interfacial tensions affect the formation of nanofibers. Dominating sacrificing polymer content in the blends and low interfacial tensions between thermoplastic polymer and CAB are two key factors. This fabrication process possesses features of high productivity, versatility of thermoplastics, controllability, and environment friendliness in manufacturing thermoplastic nanofibers.magnified image
Preparation and Properties of Natural Sand Particles Reinforced Epoxy Composites
Authors: Sui Gang , Jana Soumen , Salehi‐khojin Amin , Neema Sanjay , Zhong Wei‐Hong , Chen Hui , Huo Qun 
Published: April 2007

AbstractAn epoxy composite using Cancun natural hydrophobic sand particle as filler material was fabricated in this study. Three point bending tests demonstrated an enhancement of 7.5 and 8.7% in flexural strength and flexural modulus, respectively, of epoxy composite containing 1 wt.‐% sand particles without any chemical treatment involved, compared to the pristine epoxy. Scanning electron microscopy (SEM) studies revealed that the fracture toughness of the epoxy matrix was enhanced owing to the presence of sand particles in an epoxy/sand composite. Through dynamic mechanical analysis (DMA) and thermal mechanical analysis (TMA) methods, it was found that the storage modulus (E′), glass transition temperature (Tg) and dimensional stability of the sand particles/epoxy composites were increased compared to the pristine epoxy. The friction behavior of epoxy/sand system reflected that the microstructure of epoxy composites was steady. These experimental results suggest that Cancun sand, as a freshly found natural micron porous material, may find promising applications in composite materials.magnified image
Distinct distribution of autosomal dominant spinocerebellar ataxia in the Mexican population
Authors: Alonso Elisa , Martínez‐Ruano Leticia , De Biase Irene , Mader Christopher , Ochoa Adriana , Yescas Petra , Gutiérrez Roxana , White Misti , Ruano Luís , Fragoso‐Benítez Marcela , Ashizawa Tetsuo , Bidichandani Sanjay I. , Rasmussen Astrid 
Published: April 2007

AbstractDominant ataxias show wide geographic variation. We analyzed 108 dominant families and 123 sporadic ataxia patients from Mexico for mutations causing SCA1–3, 6–8, 10, 12, 17 and DRPLA. Only 18.5% of dominant families remained undiagnosed; SCA2 accounted for half (45.4%), followed by SCA10 (13.9%), SCA3 (12%), SCA7 (7.4%), and SCA17 (2.8%). None had SCA1, 6, 8, 12 or DRPLA. Among sporadic cases, 6 had SCA2 (4.9%), and 2 had SCA17 (1.6%). In the SCA2 patients we identified 6 individuals with the rare (CAG)33allele, 2 of whom showed early onset ataxia. The distribution of dominant ataxia mutations in Mexicans is distinct from other populations. © 2007 Movement Disorder Society