bluuebunny/crossref_metadata_2025_split huggingface dataset:
Medial collateral ligament healing in macrophage metalloelastase (MMP‐12)‐deficient mice
Authors: Wright Rick W. , Allen Tracy , El‐Zawawy Hossam B. , Brodt Michael D. , Silva Matthew J. , Gill Corey S. , Sandell Linda J. 
Published: August 2006

AbstractMedial collateral ligament (MCL) injuries heal by a wound repair scar response controlled by a complex cellular and cytokine environment. Many enzymes participate in wound repair, particularly the matrix metalloproteinases. We hypothesize macrophage metalloelastase (MME/MMP‐12) deficiency results in impaired healing of MCL injury. One hundred fifty MME‐deficient and 150 WT (MME+/+) mice underwent knee MCL transection with the opposite knee as a sham operated control. Mice were sacrificed at 3, 7, 28, 42, and 56 days. At each of the five time points, 15 mice were utilized for biological and 15 were utilized for biomechanical testing. Outcome measures were the presence of macrophages to represent the inflammatory phase of wound healing, collagen synthesis to assay for matrix repair, and biomechanical testing for repair strength. Immunohistochemistry demonstrated significantly fewer macrophages in cut MCLs from MME‐deficient mice versus wild‐type (WT) mice at 3, 7, 28, and 42 days (all p ≤ 0.04). In situ hybridization to Col1a1 mRNA in the MME‐deficient cut MCLs at 7, 28, and 42 day time points showed a decreased level of type I pro‐collagen mRNA compared to the WT cut MCLs (p < 0.05). Biomechanical testing revealed cut ligaments from MME‐deficient mice had significantly lower ultimate force and stiffness compared to cut ligaments from WT mice (p < 0.001), with maximal differences of 40% at 7 days for ultimate force and 28 days for stiffness (p < 0.05 by Tukey post hoc test). We conclude MME is important in the multifactorial cascade of knee MCL injury healing, showing significant differences in both the early inflammatory and in the matrix tissue synthesis phases. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 24:2106–2113, 2006
Effects of frictional conditions on structural transformation of mesocarbon microbeads
Authors: Cui X. H. , Li S. H. , Jin Y. S. , Fu H. L. , Song H. H. 
Published: August 2006

AbstractThe effects of frictional conditions (temperature, loading, sliding velocity) on the tribological performance of mesocarbon microbeads (MCMB), which were manufactured from selected petroleum asphalts, were investigated on an Optimal SRV tribotester when blended as a special additive in a pentaerythritol baseline. The results of the friction tests showed that enhanced heating, increased loading and rapid sliding were beneficial in decreasing friction coefficient and able to shorten the time before the onset of this decrease. A working definition of frictional intensity was elaborated to elucidate the ease with which the MCMB were tribologically transformed into their more lubricious allotropes. The more severe the applied frictional conditions, the lower the calculated value of the defined frictional intensity. Raman spectroscopic analyses of the worn areas of carbon steel tribosurfaces and calculated values of the microcrystalline planar size of the MCMB tribo‐transformed carbonaceous microcrystallines indicated that the decrease in friction coefficient was related to the structural transformation of MCMB towards highly ordered, carbonaceous allotropes. More rigorous frictional conditions would yield highly ordered structures of carbonaceous microcrystallines of bigger planar sizes. Copyright © 2006 John Wiley & Sons, Ltd.
Redesigning alkylated diphenylamine antioxidants for modern lubricants
Authors: Gatto Vincent J. , Elnagar Hassan Y. , Moehle William E. , Schneller Emily R. 
Published: August 2006

AbstractThis paper describes a new alkylation technology that is very effective at synthesizing structurally different alkylated diphenylamine chemistries relative to those currently available to lubricant formulators. Examples are provided showing how this technology can be used in a practical way to produce a variety of chemically modified nonylated diphenylamine types. One example is also provided illustrating the preparation of a higher molecular weight dodecylated diphenylamine. Engine oil performance data utilizing pressurized differential scanning calorimetry (PDSC), the thermo‐oxidation engine oil simulation test, and a bulk oil oxidation test demonstrate that subtle changes in alkylated diphenylamine chemical composition can result in significant oxidation and deposit control performance enhancements or losses. Examples of similar performance responses in industrial oils are demonstrated utilizing PDSC and the rotating pressure vessel oxidation test. These performance changes are directly related to specific structural changes in the modified products. Copyright © 2006 John Wiley & Sons, Ltd.
Lyotropic Liquid Crystalline Polyamides Containing Aromatic, Heterocyclic Structures: Preparation and Properties
Authors: Liu Pengtao , Wang Jinyan , Liu Cheng , Jian Xigao 
Published: August 2006

AbstractSummary: A series of novel lyotropic liquid crystalline polyamides derived from 1,2‐dihydro‐2‐(4‐aminophenyl)‐4‐[4‐(4‐(aminophenoxyl)phenyl)]‐phthalazinone (DHPZ‐DA), p‐phenylene diamine (PPD) and terephthaloyl dichloride (TPC) have been successfully synthesized by the low temperature solution polycondensation method. The copolymers obtained with inherent viscosity of ≈1.21 to 3.29 dl · g−1, determined in NMP (1 wt.‐% LiCl) or concentrated H2SO4 at 25 °C, were confirmed to be amorphous by WAXD and differential scanning calorimetry (DSC). Their solubility was improved by the introduction of non‐coplanar, twisted phthalazinone moieties and ether linkages into the main chain with the result that they can be soluble in some polar solvents containing a small amount of LiCl. Their Tgs were all above 310 °C and 10% weight loss temperatures in nitrogen above 500 °C. Most of these polyamides can form an anisotropic phase in concentrated H2SO4, NMP (1 wt.‐% LiCl) and DMAc (1 wt.‐% LiCl) solutions, observed on a polarizing light microscope.Optical micrograph (×40) of polyamide P‐4060 at 10 wt.‐% in NMP/LiCl (1% w/v) solution at room temperature.imageOptical micrograph (×40) of polyamide P‐4060 at 10 wt.‐% in NMP/LiCl (1% w/v) solution at room temperature.
Living Alternating Copolymerization of a Methylenecyclopropane Derivative with CO to Afford Polyketone with Dihydrophenanthrene‐1,10‐diyl Groups
Authors: Takeuchi Daisuke , Okada Takeshi , Kuwabara Junpei , Osakada Kohtaro 
Published: August 2006

AbstractSummary: Pd complexes prepared from [PdCl(Me)(L)] (L = N‐ligands) and NaBARF catalyze the alternating copolymerization of 7‐methylenedibenzo[a,c]bicyclo[4.1.0]heptane with CO to produce the polyketone. Pd complexes with substituted 1,10‐phenanthroline ligands produce the polymer with narrow molecular weight distribution. Addition of 4‐tert‐butylstyrene to the growing polymer after consumption of the initially charged monomer, results in polymer growth to afford an AB‐type block copolyketone. A Pd complex with an optically active bisoxazoline ligand produces the optically active polymer with narrow polydispersity. The addition of DBU to a solution of polyketone converts the cis‐fused six‐membered rings into the trans‐fused rings via epimerization of the CH carbon attached to the carbonyl group.Addition of I to cationic Pd complexes catalyzes the ring‐opening copolymerization of the monomer with CO to produce the polyketone, (C(CH2)C14H10CO)n (II).imageAddition of I to cationic Pd complexes catalyzes the ring‐opening copolymerization of the monomer with CO to produce the polyketone, (C(CH2)C14H10CO)n (II).
A Novel Fabrication Method for Poly(propylene)/Clay Nanocomposites by Continuous Processing
Authors: Kim Do Hoon , Park Jun Uk , Cho Kwang Soo , Ahn Kyung Hyun , Lee Seung Jong 
Published: August 2006

AbstractSummary: It is well known that poly(propylene)/clay (PP/clay) nanocomposite forms an exfoliated structure when mixed with maleic anhydride‐functionalized polypropylene (MAPP). This can be easily achieved by melt processing, however, the use of functionalized chemicals like MAPP costs a lot preventing its commercial application. Recently, it was reported that the exfoliated structure of PP/clay nanocomposite could be obtained without using any compatibilizer such as MAPP when exposed to the electric field. They could regulate the degree of dispersion and exfoliation by controlling the amount of clay loading, the strength of electric field, the time exposed to the electric field, etc. However, this was accomplished by applying the electric field on a rheometer for a long time. It will be practically attractive if we produce PP/clay nanocomposites via continuous processing like extrusion. A new design concept is required for this purpose. In this study, we present a novel method to continuously produce PP/clay nanocomposites using the electric melt pipe equipped with a twin‐screw extruder. Rheology, XRD, and SEM measurements confirm the formation of nanocomposites. Thermal‐ and dynamic‐mechanical analysis also shows the enhancement of the properties. Though, in this study, only a partial intercalation was achieved through continuous processing, it shows a possibility to produce nanocomposites by this approach. As this is a physical process that can be adapted to the conventional extrusion, the approach suggested in this study may be extended to other polymer/clay nanocomposite systems as well.Schematic diagram of electric melt pipe equipped with a twin‐screw extruder.magnified imageSchematic diagram of electric melt pipe equipped with a twin‐screw extruder.
The Effect of Silane Coupling Agents on the Viscoelastic Properties of Rubber Biocomposites
Authors: Jacob Maya , Francis Bejoy , Varughese K. T. , Thomas Sabu 
Published: August 2006

AbstractSummary: This paper deals with the dynamic mechanical study of sisal/oil palm hybrid fiber reinforced natural rubber composites (at frequency 1 Hz) with reference to the role of silane coupling agents. Composites were prepared using sisal and oil palm fibers subjected to chemical modifications with different types of silane coupling agents. The silanes used were Silane F8261 [1,1,2,2‐perfluorooctyl triethoxy silane], Silane A1100 [γ‐aminopropyltriethoxy silane] and Silane A151 [vinyl triethoxy silane]. It was observed that for treated composites, storage modulus and loss modulus increased while the damping property was found to decrease. Maximum E' was exhibited by the composite prepared from fibers treated with silane F8261 and minimum by composites containing fibers treated with silane A151. This was attributed to the reduced moisture absorbing capacity of chemically modified fibers leading to improved wetting. This in turn produced a strong interfacial interface giving rise to a much stiffer composite with higher modulus. Surface characterization of treated and untreated sisal fibers by XPS showed the presence of numerous elements on the surface of the fiber. Scanning electron micrographs of tensile fracture surfaces of treated and untreated composites demonstrated better fiber–matrix bonding for the treated composites.Scheme of interaction of silanes with cellulosic fibers.magnified imageScheme of interaction of silanes with cellulosic fibers.
Multi‐Morphological Complex Aggregates Formed from Amphiphilic Poly(ethylene oxide)‐block‐Polydimethylsiloxane‐block‐Poly(ethylene oxide) Triblock Copolymers
Authors: Zhang Yong , Zhang Zhijie , Wang Qian , Xu Caihong , Xie Zemin 
Published: August 2006

AbstractSummary: Amphiphilic triblock copolymers (PEOx‐b‐PDMSy‐b‐PEOx) with different block lengths were synthesized and multi‐morphological complex crew‐cut, star‐like, and short‐chain aggregates were prepared by self‐assembly of the given copolymers. The morphologies and dimensions of the aggregates can be well controlled by variation of the preparation conditions. TEM, SEM, FFR‐TEM, and LLS studies show the resulting morphologies range from LCMs, unilamellar or multilayer vesicles, LCVs, porous spheres to nanorods.TEM images of the vesicles formed from PEO‐b‐PDMS‐b‐PEO.magnified imageTEM images of the vesicles formed from PEO‐b‐PDMS‐b‐PEO.
Gold Nanostructures Formed in Ionic Clusters of Perfluorinated Ionomer
Authors: Han Tai‐Hoon , Kim Dong‐Ouk , Lee Youngkwan , Suh Su‐Jeong , Jung Hyun‐Chul , Oh Yong‐Soo , Nam Jae‐Do 
Published: August 2006

AbstractSummary: Gold nanoparticles and nanorods have been synthesized in the ionic cluster network of Nafion using a liquid‐phase chemical impregnation/reduction process seemingly visualizing the phase‐separated hydrated cluster network of Nafion. The spherical shape of the hydrated clusters is clearly seen by the replicated gold nanoparticles with diameters of 5–6 nm. The gold nanoparticles grow through the Nafion cluster network to form gold nanorods with diameters of 5–6 nm and a characteristic length of 12–15 nm, which compare well to the previously reported small‐angle X‐ray scattering results. Tiny channels between adjacent spherical clusters are also observed, which expand to form a rod structure by a reorganization of ion exchange sites and an elastic deformation of Nafion polymer chains. The gold nanorods become interconnected in a cascadic feature, and a tripod‐shaped nanorod structure is one of the most commonly observed structures of the replicated gold. Although further study should be performed, the synthesized gold may be used to visualize the hydrated cluster and the network structure of Nafion, which could be used as important information in identifying the morphology and ion transport phenomena of Nafion.Gold nanoparticles and nanorods growing through a hydrated Nafion cluster network.magnified imageGold nanoparticles and nanorods growing through a hydrated Nafion cluster network.
Thienopyrazine‐Based Low‐Bandgap Poly(heteroaryleneethynylene)s for Photovoltaic Devices
Authors: Ashraf Raja Shahid , Shahid Munazza , Klemm Elisabeth , Al‐Ibrahim Maher , Sensfuss Steffi 
Published: August 2006

AbstractSummary: Low‐bandgap π‐conjugated polymers that consist of alkyl thiophene/alkoxy phenylene and 2,3‐diphenylthieno[3,4‐b]pyrazine units have been prepared in high yields by a Sonogashira polycondensation. The copolymers are characterized by NMR, IR, UV, GPC, and elemental analysis. Thin films of the polymers P1, P2, and P3 exhibit an optical bandgap of ≈1.57–1.60 eV. Under simulated AM 1.5 conditions P2/PCBM devices on polyester foil provide a short circuit current of ISC = 10.72 mA · cm−2, an open circuit voltage of Voc = 0.67 V, and a power conversion efficiency of 2.37%.Schematic of the photovoltaic device made from the polymers synthesized here.magnified imageSchematic of the photovoltaic device made from the polymers synthesized here.
Delamination of Organically Modified Layered Filler via Solid‐State Processing
Authors: Saito Tomotaka , Okamoto Masami , Hiroi Ryoichi , Yamamoto Minoru , Shiroi Takashi 
Published: August 2006

AbstractSummary: Solid‐state processing for the preparation of poly(p‐phenylenesulfide) (PPS‐) based nano‐composites having finely dispersed layered fillers was conducted. The mixture of PPS and organically modified layered filler (OMLF) (95/5 wt./wt.) was subjected to the processing using thermostated hot‐press at 150 °C, below Tm of PPS (i.e., PPS is still at the solid‐state), and applying pressures of 33 MPa for 30 s. The mixture exhibited disorder and delaminated layer structure with the thickness of 10–20 nm into the PPS matrix. In contrast, a nano‐composite prepared by melt compounding at 300 °C for 3 min showed large stacked silicate layers in the PPS matrix. The processing led to delamination of the silicate layers and attained the discrete dispersion.TEM bright field image and FFT spectrum of a solid‐state processed PPS nano‐composite.magnified imageTEM bright field image and FFT spectrum of a solid‐state processed PPS nano‐composite.
Spinocerebellar ataxia type 1, 2, and 3 and restless legs syndrome: Striatal dopamine D2 receptor status investigated by [11C]raclopride positron emission tomography
Authors: Reimold Matthias , Globas Christoph , Gleichmann Marc , Schulze Michael , Gerloff Christian , Bares Roland , Machulla H.‐J. , Bürk Katrin 
Published: August 2006

AbstractIn spinocerebellar ataxias (SCAs), up to 30% of patients complain of restless legs syndrome (RLS). In primary RLS, a putative role of the dopaminergic system has been postulated. To assess dopaminergic function in SCA1, 2, and 3, dopamine D2 receptor binding potential (BP) was assessed by [11C]raclopride positron emission tomography in 10 SCA patients, 4 of whom suffered from RLS as demonstrated by polysomnography. BP was compared to 9 age‐matched control subjects. In 2 SCA patients, striatal BP was clearly reduced (<2 SD below the mean of controls). However, there were no significant group differences between SCA and controls, largely owing to a significantly higher variance of striatal BP in SCA. BP was negatively correlated with disease duration. The fit suggests an increased BP in early stages, followed by a moderate decline in all quantified regions (caudate, dorsal putamen, ventral striatum) presumably reflecting a progressive loss of D2 receptors. RLS in SCA was not accompanied by a significant reduction of D2 receptor availability in the striatum. This missing correlation may point to an extrastriatal origin of RLS. © 2006 Movement Disorder Society
Time of loss of employment in Parkinson's disease
Authors: Schrag Anette , Banks Pauline 
Published: August 2006

AbstractWe examined time to loss of employment in two U.K.‐based studies of 151 and 308 patients with Parkinson's disease (PD) with onset age before 65 years. Fifty‐two percent and 57% of patients had retired early due to PD, 18% and 5% of patients were unemployed, and 8% and 11% were part‐time–employed. Mean age of retirement was 55.8 years compared to an average retirement age of 62 years in the U.K. population. Mean time to loss of employment was 4.9 years, ranging from a mean of 6.7 years in those with onset before age 45 to 1.7 years in those with onset after age 56, but the range was large (0–17 years). After censoring for those still working and those retiring at a normal retirement age, survival analysis revealed that 46% had stopped working after a disease duration of 5 years and 82% after 10 years with a median survival to loss of employment of 6.0 (95% CI: 5.4–6.6) years. Age of onset correlated negatively with time to loss of employment (r = −0.6; P < 0.001). There were no differences between sexes, rural vs. urban living, types of work, those living alone or with a partner, and those with and without children in their household. We conclude that Parkinson's disease leads to loss of employment on average within less than 10 years of disease onset. However, the variability of time to loss of employment is large, indicating that other factors than onset age and disease duration influence loss of patients' employment. © 2006 Movement Disorder Society
Joint and skeletal deformities in Parkinson's disease, multiple system atrophy, and progressive supranuclear palsy
Authors: Ashour Ramsey , Jankovic Joseph 
Published: August 2006

AbstractThe objective of this study is to characterize clinical features of joint and skeletal deformities in Parkinson's disease (PD), multiple system atrophy (MSA), and progressive supranuclear palsy (PSP). Clinical information including age, gender, presence of deformity, initial symptom side, neuropsychological and motor features, family history, and treatment with levodopa/dopamine agonists was collected on consecutive patients with PD, MSA, and PSP evaluated at the Movement Disorders Clinic at Baylor College of Medicine. In this series of 202 patients, 36.1% had deformities of the limbs, neck, or trunk, including 33.5% of PD, 68.4% of MSA, and 26.3% of PSP patients. “Striatal” hand and foot deformities were present in 13.4%, involuntary trunk flexion in 12.9%, anterocollis in 9.4%, and scoliosis in 8.4% of all patients. Patients with these joint and skeletal deformities had higher mean Unified Parkinson's Disease Rating Scale scores (57.4 vs. 46.6; P < 0.01) and were more often treated with levodopa (69.9% vs. 50.4%; P < 0.01) than patients without deformity, independent of disease duration. Patients with striatal deformity were younger than patients without deformity (mean 60.4 vs. 68.6 years; P < 0.01), and they tended to have an earlier age of onset of initial parkinsonian symptoms (mean 54.7 vs. 62.5 years; P < 0.01). Furthermore, the side of striatal deformity correlated with the side of initial parkinsonian symptoms in all patients (100%) with striatal hand and in 83.3% of patients with striatal foot. Joint and skeletal deformities are common and frequently under‐recognized features of PD, MSA, and PSP that often cause marked functional disability independent of other motor symptoms. © 2006 Movement Disorder Society
Open‐label pilot study of levetiracetam (Keppra) for the treatment of chorea in Huntington's disease
Authors: Zesiewicz Theresa A. , Sullivan Kelly L. , Hauser Robert A. , Sanchez‐Ramos Juan 
Published: August 2006

AbstractThe objective of this study is to evaluate the tolerability and preliminary efficacy of levetiracetam (LEV) in reducing chorea in Huntington's disease (HD) patients in a prospective open‐label pilot study. Nine HD patients with chorea were treated with LEV in doses up to 3,000 mg/day for up to 48 days. The primary endpoint measure was the Unified Huntington's Disease Rating Scale (UHDRS) chorea subscore. The mean dose (±SD) of LEV at endpoint was 2,583.3 ± 1,020.6 mg/day. Mean UHDRS chorea score decreased from 12.6 ± 3.0 at baseline to 6.7 ± 4.3 at endpoint (P = 0.01). There was no significant change in UHDRS total motor scores (38.8 ± 11.4 at baseline and 33.6 ± 26.7 at endpoint; P = 0.24). Somnolence contributed to a 33% drop‐out rate, and 3 patients developed Parkinsonism. Results of this open label study suggest that LEV may be efficacious in reducing chorea in HD patients. © 2006 Movement Disorder Society
Case–control study of UCHL1 S18Y variant in Parkinson's disease
Authors: Tan Eng‐King , Puong Kim‐Yoong , Fook‐Chong Stephanie , Chua Eva , Shen Hui , Yuen Yih , Pavanni Ratnagopal , Wong Meng‐Cheong , Puvan Kathiravelu , Zhao Yi 
Published: August 2006

AbstractA recent meta‐analysis observed a greater significant inverse association of the ubiquitin carboxy‐terminal hydrolase L1 (UCHL1) S18Y variant with Parkinson's disease (PD) for Asian (predominantly Japanese) populations compared with Caucasian populations. We performed an independent case–control study in 335 PD and 341 control subjects with data from a Chinese population to investigate the age‐of‐onset effect of the UCHL1 variant in PD. The Y/Y and Y/S genotypes were less frequent in the PD young‐onset group than in controls and the frequency of the Y alleles was higher in young controls compared to young‐onset PD (age at examination ≤ 65 years; P = 0.003). Multivariate analysis revealed the Y/Y genotype was significantly lower (P = 0.008) in the young‐onset PD (Y/Y vs. S/S: odds ratio [OR]: 0.42; 95% confidence interval [CI]: 0.24, 0.74; S/Y vs. S/S: OR: 0.66, 95% CI: 0.41, 1.08) compared with controls, but this difference was not seen for the late‐onset PD. Kaplan–Meier analysis carried out on PD subjects demonstrated that the Y/Y genotype was associated with a later onset of PD than Y/S plus S/S genotypes (P = 0.05). We provided an independent confirmation of the protective effect of the UCHL1 S18Y variant (Y/Y genotype) against PD in young Chinese subjects. Further functional studies of the S18Y variant in both cell and animal models will be of interest. © 2006 Movement Disorder Society