bluuebunny/crossref_metadata_2025 huggingface dataset:
Two-Year Safety and Efficacy of Inhaled Human Insulin (Exubera) in Adult Patients With Type 1 Diabetes
Authors: Skyler Jay S. , Jovanovic Lois , Klioze Sol , Reis Joann , Duggan William ,   for the Inhaled Human Insulin Type 1 Diabetes Study Group
Published: February 2007

OBJECTIVE—The purpose of this study was to evaluate the long-term (2-year) safety and efficacy of inhaled human insulin (Exubera [insulin human (rDNA origin)] inhalation powder) (EXU) in adult patients with type 1 diabetes.

RESEARCH DESIGN AND METHODS—Patients were randomly assigned to receive EXU (n = 290) or subcutaneous (SC) insulin (n = 290), plus basal (intermediate- or long-acting) insulin. The primary end point was the annual rate of decline in pulmonary function (forced expiratory volume in 1 s [FEV1] and carbon monoxide diffusing capacity [DLCO]).

RESULTS—The mean ± SEM annual rates of change between months 0 and 24 were −0.051 ± 0.005 l/year with EXU and −0.034 ± 0.005 l/year with SC insulin (significant mean difference −0.017 ± 0.007 l/year [90% CI −0.028 to −0.005]) for FEV1 and −0.437 ± 0.073 ml · min−1 · mmHg−1 · year−1 with EXU and −0.287 ± 0.065 ml · min−1 · mmHg−1 · year−1with SC insulin (nonsignificant mean difference −0.150 ml · min−1 · mmHg−1 · year−1 [−0.310 to 0.011]) for DLCO. The mean annual rates of change in FEV1 between months 3 and 24 were −0.041 ± 0.005 and −0.031 ± 0.006 l/year in the EXU and SC insulin groups, respectively (nonsignificant mean difference −0.011 l/year [−0.023 to 0.002]), indicating that the significant difference between the treatment groups in FEV1 developed during the first 3 months and was not progressive thereafter. Adverse event profiles were similar except for a higher incidence of cough (usually mild and unproductive) in patients receiving EXU (37.6 vs. 13.1%) that decreased to 1.3% by month 24. Glycemic control was sustained in both groups (adjusted mean treatment difference in change from baseline A1C at month 24 0.25 ± 0.07% [0.13–0.37]). Although the overall hypoglycemic events were comparable between groups (4.0 vs. 3.8 events/subject-month), the incidence of severe hypoglycemic events was lower with EXU than with SC insulin (2.8 vs. 4.1 events/100 subject-months, risk ratio 0.67 [0.57–0.79]). Body weight increased to a significantly lesser extent with EXU (adjusted mean treatment difference −1.25 ± 0.36 kg [−1.85 to −0.66]).

CONCLUSIONS—Treatment group differences in lung function between EXU and SC insulin in adult patients with type 1 diabetes are small, develop early, and are nonprogressive for up to 2 years of therapy.
Prevalence and Treatment of Low HDL Cholesterol Among Primary Care Patients With Type 2 Diabetes
Authors: Grant Richard W. , Meigs James B.
Published: February 2007

OBJECTIVE—Patients with diabetes remain at high risk for cardiovascular events despite aggressive blood pressure, LDL cholesterol, and blood glucose control. We identified prevalence and predictors of low HDL cholesterol, characterized current lipid therapy, and estimated the theoretical benefit of more effective HDL cholesterol–raising methods among patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS—We analyzed a primary care–based population of patients with type 2 diabetes (n = 7,692) in 12 eastern Massachusetts outpatient practices. We grouped fibrates, niacins, and n-3 fatty acid preparations as nonstatin HDL cholesterol–raising medicines, and we used published studies to estimate the potential benefit of raising HDL cholesterol levels in this population.

RESULTS—Nearly half (49.5%) of patients had low HDL cholesterol (<40 mg/dl for men, <50 mg/dl for women). Low HDL cholesterol was independently associated with prevalent cardiovascular disease (CVD), younger age, and higher A1C levels. Nearly two-thirds of patients (63.0%) were prescribed a statin (67.6% of patients below the HDL cholesterol goal, 80.5% of patients with CVD). In contrast, only 7.9% of patients were prescribed a nonstatin HDL cholesterol–raising medication, including 16.4% of patients below the HDL cholesterol goal with CVD. Based on published studies, normalizing low HDL cholesterol in this primary care cohort would correspond to an estimated CVD mortality reduction of 42% in women and 23% in men.

CONCLUSIONS—Nearly half of the patients in this large primary care cohort had low HDL cholesterol levels. In contrast to frequent statin use, few patients were prescribed currently available medicines to raise HDL cholesterol. Low HDL cholesterol represents a highly prevalent and potentially modifiable risk factor for CVD prevention in type 2 diabetes.
Dual Endothelin Receptor Blockade Acutely Improves Insulin Sensitivity in Obese Patients With Insulin Resistance and Coronary Artery Disease
Authors: Ahlborg Gunvor , Shemyakin Alexey , Böhm Felix , Gonon Adrian , Pernow John
Published: February 2007

OBJECTIVE—Endothelin (ET)-1 is a vasoconstrictor and proinflammatory peptide that may inhibit glucose uptake. The objective of the study was to investigate if ET (selective ETA and dual ETA+ETB) receptor blockade improves insulin sensitivity in patients with insulin resistance and coronary artery disease.

RESEARCH DESIGN AND METHODS—Seven patients (aged 58 ± 2 years) with insulin resistance and coronary artery disease completed three hyperinsulinemic-euglycemic clamp protocols: a control clamp (saline infusion), during ETA receptor blockade (BQ123), and during combined ETA (BQ123) and ETB receptor blockade (BQ788). Splanchnic blood flow (SBF) and renal blood flow (RBF) were determined by infusions of cardiogreen and p-aminohippurate.

RESULTS—Total-body glucose uptake (M) differed between the clamp protocols with the highest value in the BQ123+BQ788 clamp (P < 0.05). The M value corrected by insulin was higher in the BQ123+BQ788 than in the control clamp (P < 0.01) or the BQ123 clamp (P < 0.05). There was no difference between the control clamp and the BQ123 clamp. Mean arterial pressure did not change during the control clamp, whereas it decreased during both the BQ123 (P < 0.01) and BQ123+BQ788 (P < 0.05) clamps. RBF increased and renal vascular resistance decreased in the BQ123+BQ788 clamp (P < 0.05) but not in the BQ123 clamp. There was no change in SBF in either clamp.

CONCLUSIONS—Dual ETA+ETB receptor blockade acutely enhances insulin sensitivity in patients with insulin resistance and coronary artery disease, indicating an important role for endogenous ET-1.
Association of Television Viewing With Fasting and 2-h Postchallenge Plasma Glucose Levels in Adults Without Diagnosed Diabetes
Authors: Dunstan David W. , Salmon Jo , Healy Genevieve N. , Shaw Jonathan E. , Jolley Damien , Zimmet Paul Z. , Owen Neville ,   on behalf of the AusDiab Steering Committee
Published: February 2007

OBJECTIVE—We examined the associations of television viewing time with fasting plasma glucose (FPG) and 2-h postchallenge plasma glucose (2-h PG) levels in Australian adults.

RESEARCH DESIGN AND METHODS—A total of 8,357 adults aged >35 years who were free from diagnosed diabetes and who attended a population-based cross-sectional study (Australian Diabetes, Obesity and Lifestyle Study [AusDiab]) were evaluated. Measures of FPG and 2-h PG were obtained from an oral glucose tolerance test. Self-reported television viewing time (in the previous week) was assessed using an interviewer-administered questionnaire. Homeostasis model assessment (HOMA) of insulin sensitivity (HOMA-%S) and β-cell function (HOMA-%B) were calculated based on fasting glucose and insulin concentrations.

RESULTS—After adjustment for confounders and physical activity time, time spent watching television in women was positively associated with 2-h PG, log fasting insulin, and log HOMA-%B and inversely associated with log HOMA-%S (P < 0.05) but not with FPG. No significant associations were observed with glycemic measures in men. The β-coefficients across categories of average hours spent watching television per day (<1.0, 1.0–1.9, 2.0–2.9, 3.0–3.9, and ≥4.0) for 2-h PG in women were 0 (reference), 0.009, 0.047, 0.473, and 0.501, respectively (P for trend = 0.02).

CONCLUSIONS—Our findings highlight the unique deleterious relationship of sedentary behavior (indicated by television viewing time) and glycemic measures independent of physical activity time and adiposity status. These relationships differed according to sex and type of glucose measurement, with the 2-h PG measure being more strongly associated with television viewing. The findings suggest an important role for reducing sedentary behavior in the prevention of type 2 diabetes and cardiovascular disease, especially in women.
Impact of Disease Characteristics on the Efficacy of Duloxetine in Diabetic Peripheral Neuropathic Pain
Authors: Ziegler Dan , Pritchett Yili L. , Wang Fujun , Desaiah Durisala , Robinson Michael J. , Hall Jerry A. , Chappell Amy S.
Published: February 2007

OBJECTIVE—To evaluate the impact of baseline disease variables related to diabetes and diabetic neuropathy severity on efficacy and safety of duloxetine in the management of diabetic peripheral neuropathic pain.

RESEARCH DESIGN AND METHODS—The impact of baseline conditions was evaluated using the data from three pooled placebo-controlled studies for combined duloxetine, doses of 60 mg q.d. and 60 mg b.i.d., versus placebo. The primary efficacy measure was the weekly mean of 24-h average pain severity, and night pain was the secondary measure. Safety and tolerability were assessed.

RESULTS—There were no significant (P > 0.10) interactions of treatment by age (<65 or ≥65 years), type of diabetes (type 1 or type 2), duration of diabetes (median split <9.18 or ≥9.18 years), duration of diabetic neuropathy (<2, 2 to <6, or ≥6 years), severity of diabetic neuropathy (baseline Michigan Neuropathy Screening Instrument score <5 or ≥5), baseline A1C level (median split <7.6 or ≥7.6%), or baseline insulin use (yes/no). Significant interactions for both pain measures were observed in baseline pain subgroups (Brief Pain Inventory average pain, ≥6 and <6). Duloxetine was more effective in the subgroup with more pain. No significant association was found between any other subgroups (P > 0.10). Significant interactions (P < 0.1) occurred with treatment-emergent adverse events when stratified by subgroups.

CONCLUSIONS—Pain severity but not variables related to diabetes or neuropathy may predict the effects of duloxetine in diabetic peripheral neuropathic pain. The efficacy of duloxetine is related to the initial pain severity and is generalizable across a broad spectrum of diabetic patients, including those with the highest severity of diabetes or neuropathy.
Rate of Healing of Neuropathic Ulcers of the Foot in Diabetes and Its Relationship to Ulcer Duration and Ulcer Area
Authors: Ince Paul , Game Fran L. , Jeffcoate William J.
Published: February 2007

OBJECTIVE—To examine the outcome of neuropathic foot ulcers and to seek associations between healing and features of the ulcers at baseline.

RESEARCH DESIGN AND METHODS—Data were collected prospectively during the course of routine management. All patients were selected who presented to a single unit between 1 January 2000 and 31 December 2004 with neuropathic foot ulcers and without evidence of either peripheral arterial disease or infection. Associations were sought between ulcer characteristics at baseline and clinical outcome.

RESULTS—A total of 154 patients (66.9% male) presented with 410 ulcers. Age was 57.4 ± 12.0 years (means ± SD). A total of 178 (43.4%) ulcers were on the plantar aspect of the foot; 73.7% of ulcers had a cross-sectional area of <1 cm2. Median ulcer duration at referral was 15 days (range 1–1,046). Healing without amputation was observed in 91.7%. The percentage of ulcers healed at 12, 20, and 52 weeks were 59.3, 70.5, and 86.6%, respectively. Significant associations were observed between area at referral and outcome type (χ2 P < 0.0001), prior ulcer duration (Kruskal-Wallis P = 0.006), and time to healing (Kruskal-Wallis P = 0.014), as well as between ulcer duration and time to healing (Spearman ρ, r = 0.104, P = 0.047). There was no difference between plantar and nonplantar ulcers.

CONCLUSIONS—The rate of healing in this cohort provides a benchmark for comparison with other centers. While further work is needed to determine how outcomes can be improved in unselected series such as these, the confirmation of close relationships between ulcer duration at referral, ulcer area, and outcome emphasizes the importance of early expert assessment of newly occurring neuropathic ulcers.
Impaired Skin Microvascular Reactivity in Painful Diabetic Neuropathy
Authors: Quattrini Cristian , Harris Nigel D. , Malik Rayaz A. , Tesfaye Solomon
Published: February 2007

OBJECTIVE—The pathogenesis of painful diabetic neuropathy (PDN) is not clear. Following our in vivo observations of increased sural nerve epineurial blood flow in patients with PDN, we investigated the cutaneous microcirculation of the foot by laser Doppler flowmetry to determine if the epineurial findings were just confined to the nerve or more widespread in other vascular beds.

RESEARCH DESIGN AND METHODS—We measured foot skin vasodilator responses to acetylcholine (Ach) and sodium nitroprusside (SNP) and vasoconstrictor responses to sympathetic (deepest possible gasp) stimulation in 5 healthy control subjects, 10 non-neuropathic diabetic (NND) patients, 10 diabetic patients with painless neuropathy (PLDN), and 8 diabetic patients with PDN.

RESULTS—In PDN, there were significantly reduced responses to Ach (ANOVA P = 0.003) and vasoconstrictor inspiratory gasp (ANOVA P < 0.001) but not to SNP (NS). Post hoc analysis showed significant differences in Ach-induced vasodilation between PDN and nondiabetic control subjects (P < 0.05) as well as between PDN and NND (P < 0.05) but not PDN and PLDN (NS). There were no significant differences for SNP-induced vasodilation. However, there were significant differences in the vasoconstrictor response between PDN and control, NND, and PLDN (P < 0.01).

CONCLUSIONS—We found an impairment of cutaneous endothelium-related vasodilation and C-fiber–mediated vasoconstriction in PDN. Inappropriate local blood flow regulation may have a role in the pathogenesis of pain in diabetic neuropathy. Prospective studies are required to determine the temporal relationship of these changes in relation to the emergence of neuropathic pain.
Meeting Quality Standards for Self-Management Education in Pediatric Type 2 Diabetes
Authors: Atkinson Amber , Radjenovic Doreen
Published: February 2007

Educational interventions in pediatric practices have typically focused on individuals with type 1 diabetes. Because the prevalence of type 2 diabetes is increasing in pediatric patients, the process of diabetes self-management education (DSME) must be expanded to incorporate appropriate materials and methods for youth with type 2 diabetes. To meet quality education standards in a pediatric program, DSME should be individualized, be provided by a multidisciplinary team, involve family members, and strategize behavior change with opportunities for periodic reinforcement. Content areas for a comprehensive DSME program for youth with type 2 diabetes are outlined, and an annotated bibliography of available materials is provided.
Rate of convergence to the semi-circle law for the Deformed Gaussian Unitary Ensemble
Authors: Götze Friedrich , Tikhomirov Alexander , Timushev Dmitry
Published: February 2007

It is shown that the Kolmogorov distance between the expected spectral distribution function of an n × n matrix from the Deformed Gaussian Ensemble and the distribution function of the semi-circle law is of order O(n
−2/3+v
).
High-quality MBE growth of AlχGa1-χ
As-based THz quantum cascade lasers
Authors: Roch Tomas , Andrews Aaron , Fasching Gernot , Benz Alexander , Schrenk Werner , Unterrainer Karl , Strasser Gottfried
Published: February 2007

High-quality GaAs-based quantum cascade laser (QCL) structures for the terahertz (THz) emission have been grown by solid source molecular-beam epitaxy. Ex-situ high-resolution x-ray diffraction shows that layer thickness and its control is the most critical growth aspect and that the lasing potential of the structure can be determined by the thickness accuracy of the layers. For our samples, the thickness tolerance for working lasing structures emitting approximately 100 μm was determined to be minimally above 1% for a 15 μm active region which was composed of 54.6 nm cascade cells. Increasing interface roughness adversely affects the lasing threshold and power.
Creep strain recovery of Fe-Ni-B amorphous metallic ribbon
Authors: Juríková Alena , Csach Kornel , Miškuf Jozef , Ocelík Václav
Published: February 2007

Creep strain recovery and structural relaxation of the amorphous metallic glass Fe40Ni41B19 after longtime loading at different annealing temperatures below the glass transition temperature have been studied using anisothermal differential scanning calorimetry (DSC) and dilatometry (TMA). It has been demonstrated that structural relaxation effects depend on the stress-annealing temperature of the amorphous ribbon. The structural relaxation states of the amorphous ribbon annealed at different temperatures under and without applied stress have been compared. The activation energy spectra were calculated from the anisothermal dilatometric measurements using the modern method based on the Fourier transformation technique. The influence of the annealing temperature on the shape of creep strain recovery spectra has been analyzed.
A Light‐Driven Pseudo[4]rotaxane Encoded by Induced Circular Dichroism in a Hydrogel
Authors: Ma X. , Wang Q. , Qu D. , Xu Y. , Ji F. , Tian H.
Published: February 2007

A light‐driven pseudo[4]rotaxane 1, based on α‐cyclodextrin (α‐CyD) and cucurbit[7]uril (CB[7]), is prepared in an easy and convenient manner. The reference pseudo[2]rotaxane 2 and pseudo[3]rotaxane 2′ are obtained via the insertion of α‐CyD and CB[7] onto the dumbbell 3, thus including an azobenzene unit and two viologen moieties, respectively. The CyD macrocycle in pseudo[4]rotaxane 1 can be photochemically stimulated to shuttle accompanied with obvious induced circular dichroism (ICD) signals. The ICD performances of these pseudorotaxanes, including ICD in aqueous solution, variable‐temperature ICD, ICD in confected hydrogel systems and in solid‐state films, are investigated for their conformational identification. The photo‐driven shuttling of the CyD macrocycle in pseudo[4]rotaxane 1 is easier than in the CyD‐based pseudo[2]rotaxane 2, especially in non‐solution media. This can be attributed to the space exploitation of CB[7]‐included parts, which aid the movement of α‐CyD.
Nanopiezotronics
Authors: Wang Z. L.
Published: February 2007

This article introduces the fundamental principle of nanopiezotronics, which utilizes the coupled piezoelectric and semiconducting properties of nanowires and nanobelts for designing and fabricating electronic devices and components, such as field‐effect transistors and diodes. The physics of nanopiezotronics is based on the principle of a nanowire nanogenerator that converts mechanical energy into electric energy. It is anticipated to have a wide range of applications in electromechanical coupled electronics, sensing, harvesting/ recycling energy from the environment, and self‐powered nanosystems.
Inside Front Cover: Photoinduced Nitrosyl Linkage Isomers Uncover a Variety of Unconventional Photorefractive Media (Adv. Mater. 5/2007)
Authors: Schaniel D. , Imlau M. , Weisemoeller T. , Woike T. , Krämer K. W. , Güdel H.‐U.
Published: February 2007

Photorefraction, i.e., a light‐induced change of the refractive index, is uncovered as general feature of light‐induced linkage isomers in [ML5NO]n± compounds, independent of the metals M, the ligands L, or the charge n. Dominik Schaniel and co‐workers report on p. 723 that huge amplitudes of refractive‐index changes, up to 10–2, give rise to pronounced holographic light scattering, which is visualized by impressively bright cones of scattered light, as shown on the inside cover.
Quantification of performance of sensor networks for fault diagnosis
Authors: Narasimhan Sridharakumar , Rengaswamy Raghunathan
Published: February 2007

Safety and optimality are crucial requirements in every industrial process. The success of any fault diagnosis technique depends critically on the sensors measuring the important process variables. Choosing an appropriate sensor network is a combinatorially difficult problem, especially when the number of potential measurements is large. There has been considerable amount of work that has been done on developing algorithms for sensor network design for fault diagnosis based on quantitative and qualitative models. Various objectives, such as cost, reliability and fault resolution have been used in the sensor network design. While these design algorithms can provide the best design locations for a given cost, the value of the sensor network for fault diagnosis or benefit accrued is usually not quantified in a manner that is transparent to the user. This is an important aspect that needs to be addressed if these algorithms have to be assimilated into industrial practice. An approach for characterizing the value of a sensor network from a fault diagnosis perspective is proposed. This notion of value can be used directly in sensor network design algorithms. The proposed concepts are explained through a simple example and numerical simulations of a CSTR. © 2007 American Institute of Chemical Engineers AIChE J, 2007
Mass transfer in coal seams for CO2 sequestration
Authors: Wang F. Y. , Zhu Z. H. , Massarotto P. , Rudolph V.
Published: February 2007

CO2 sequestration in coal seams is a relatively new technique to simultaneously achieve enhanced coal bed methane production and reduced CO2 emission. In this article, we integrate understandings in individual research fields to provide improved insight into the nature of this complex process. Our current overall model constructed from a number of sub‐models consists of mass transfer in four pore types, namely, fractures, micro‐, meso‐, and macro‐pores, all having pore size dependent characteristics. Key parameters are estimated using well established methods from the general literature. Three mechanisms of coal swelling leading to permeability variations during adsorption are proposed based on molecular simulations. The macroscopic level model is validated using a true tri‐axial stress coal permeameter, which provides previously unpublished, accurate dynamic measurements of systems properties in three orthogonal directions including changes to the coal matrix volume. The integrated model provides a more complete and flexible representation for this complex system. © 2007 American Institute of Chemical Engineers AIChE J, 2007
Effect of order of mixing on morphology and thermal properties of the compatibilized PBT and ABS alloys/OMT nanocomposites
Authors: Xiao Junfeng , Hu Yuan , Lu Hongdian , Cai Yibing , Chen Zuyao , Fan Weicheng
Published: February 2007

Poly(butylene terephthalate) (PBT) and acrylonitrile–butadiene–styrene terpolymers (ABS) alloys/organically modified montmorillonite (OMT) nanocomposites using terpolymers of random ethylene, methyl acrylate, and glycidyl methacrylate as the reactive compatibilizer were prepared by different melt‐mixing sequences. The microstructures were characterized by scanning electron microscopy, X‐ray diffraction, transmission electron microscopy, and high‐resolution electron microscopy. It was found that order of mixing affects the dispersion state of OMT in the alloy matrix. The crystallization behavior of PBT in the compatibilized PBT and ABS alloys/OMT nanocomposites was studied by wide angle X‐ray diffraction. It revealed that order of mixing has influence on the preferential crystal growing direction of PBT owing to the antagonistic effect of ABS and OMT. Thermogravimetric analyses and differential scanning calorimetry also showed order of mixing changes the thermal property of the compatibilized PBT and ABS alloys/OMT nanocomposites. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2130–2139, 2007
Swelling behaviors of ionic poly(N,N‐dimethylacrylamide‐co‐acrylamide) hydrogels in various media
Authors: Çaykara Tuncer , Akçakaya İlkay
Published: February 2007

Polyelectrolyte hydrogels were synthesized from N,N‐dimethylacrylamide, acrylamide, and itaconic acid with ammonium persulfate as a free‐radical initiator in the presence of methylene(bis)acrylamide as a crosslinker. The swelling behavior of the ionic poly(N,N‐dimethylacrylamide‐co‐acrylamide) hydrogels was investigated in pure water, in KSCN solutions with pHs 4 and 9, and in water–acetone mixtures according to the itaconic acid content in the hydrogel. The pulsatile swelling behavior of these hydrogels was studied both in water–acetone and in pH 2–9 buffer solutions. Although the equilibrium swelling ratio of the hydrogels with low concentrations of itaconic acid was almost not affected by changes in the temperature, the equilibrium swelling ratio of the hydrogels with high concentrations of itaconic acid increased in the temperature range of 20–50°C. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2140–2145, 2007
Acrylic‐based nanocomposite resins for coating applications
Authors: Nobel M. L. , Mendes E. , Picken S. J.
Published: February 2007

Acrylic‐based nanocomposite resins have been investigated in view of future application in water borne automotive coatings by the aid of postemulsification processes. Mechanical, flow and leveling properties of the nanocomposite resins, containing various concentrations of silicate, have been investigated. The results are related to morphological information obtained from TEM and WAXS measurements in the liquid suspension as well as from the cured film. At low silicate loadings, when flow properties are still acceptable for typical emulsification processing, a strong increase in modulus of the cured coating films is observed because of the mainly exfoliated silicate platelets. The rate of increase in modulus of the cured films decreases at higher silicate loadings. Analyzing the mechanical data, using Halpin–Tsai theory indicates that this is due to less perfect exfoliation at higher silicate loading, which is confirmed by TEM analysis. In addition at higher silicate loading, the flow properties of the resin as analyzed by DMA show solid‐like behavior. This can lead to poor film formation in future application. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2146–2156, 2007
Batch and continuous processing of polymer layered organoclay nanocomposites
Authors: Demirkol Emre A. , Kalyon Dilhan M.
Published: February 2007

The generation of nanocomposites upon intercalation and exfoliation of clay tactoids using melt compounding is a difficult process. In this study various polymeric binders were melt compounded with organophilic clay particles using myriad methods, including sonication, batch mixing, and twin screw extrusion. The characterization of the compounded samples employing X‐ray diffraction (XRD) and transmission electron microscopy (TEM) revealed that there is little intercalation and exfoliation when nonpolar poly(dimethyl siloxane) (PDMS) and poly(propylene) (PP) binders were used, resulting in no significant changes in the dynamic properties of the suspensions upon small‐amplitude oscillatory shearing. On the other hand, when polar polymeric binders, i.e., silanol terminated poly(dimethyl siloxane) and maleic anhydride modified PP were used for compounding with organoclays, TEM and XRD revealed intercalation with some partial exfoliation, resulting in increases in the dynamic properties, along with sensitivity to the thermomechanical history during processing. These results reinforce earlier findings, which suggest that the interfacial properties between the organoclays and the polymeric binders need to be tailored properly to enable the generation of nanocomposites of organoclays using melt compounding technologies. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1391–1398, 2007
Degradation kinetics of acrylonitrile/methyl vinyl ketone copolymers
Authors: Hou Chen , Guo Zhenliang , Liu Junshen , Ying Liang
Published: February 2007

Methyl vinyl ketone (MVK) was first used to successfully copolymerize with acrylonitrile (AN). This was achieved by using azobisisobutyronitrile as the initiator. Differential scanning calorimetry results of the degradation of AN/MVK copolymers in air are presented. The apparent activation energy of degradation of the copolymers was calculated with Kissinger method. Effects of copolymerization conditions on the apparent activation energy of the copolymers were studied. It has been found that increasing dimethyl sulfoxide concentration in the solvent mixture leads to a rapid increase in the degradation apparent activation energy of AN/MVK copolymers. The apparent activation energy decreases quickly along with increase in the comononer MVK concentration, and this change becomes less prominent as the weight ratio of MVK/AN goes beyond 7/93. The apparent activation energy shows a trend of increase as the copolymerization temperature increases. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1386–1390, 2007
Tensile strength and its variation for PAN‐based carbon fibers. II. Calibration of the variation from testing
Authors: Yao Jiangwei , Yu Weidong
Published: February 2007

The tensile behavior of carbon fibers shows large scattering. This is due to the fiber itself and the testing operations. Because of the high tenacity and modulus, low strain, and easy breakability in bending, not only is the tensile test for single carbon fibers extremely difficult, but the measured results are also oppugned. To achieve a reliable and accurate characterization, several factors influencing the objective and exact testing of single carbon fibers have been measured and discussed, including the wrong pretension, nonaxial stretching, and adhesion effects. The experimental results indicate that the error of strain causing them ranges from 1.5 to 12.3%. Because of the typical linear stress–strain curves of carbon fibers, the ratio of the strain error to the modulus error is approximately equal to 1 : 1, so the calibration of the measured strain must be conducted for the accurate evaluation of the modulus and itself. The calibration is put forward. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2625–2632, 2007
Dynamic wetting of plasma‐treated polypropylene nonwovens
Authors: Wei Qufu , Wang Yingying , Hou Dayin , Huang Fenglin
Published: February 2007

Various techniques have been employed to improve the wettability of polypropylene materials for a wide range of applications. In this study, polypropylene nonwovens were treated in oxygen plasma for improving water adsorption properties. The effects of plasma treatment on wetting and water adsorption behavior were characterized using dynamic contact angle measurements and dynamic sorption measurements. The introduction of hydrophilic groups was detected by attenuated total reflection–Fourier transform infrared spectroscopy. The plasma treatment roughened the fiber surface revealed by atomic force microscopy. The roughened and hydrophilic surface resulted in the change in advancing and receding contact angles. The dynamic sorption measurements also examined the water adsorption behavior of the materials. The investigation revealed that plasma treatment could significantly improve the water adsorption properties of polypropylene nonwovens. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2157–2160, 2007
Synthesis and conducting and thermal properties of polysilanes containing substituted benzophenanthrene groups
Authors: Li Meijiang , Qiu Huayu , Jiang Jianxiong , Lai Guoqiao , Feng Shengyu
Published: February 2007

Dichloromethyl(2,9‐diphenyl‐7,8‐benzophenanthryl)silane (1) was synthesized by the Diels–Alder reactions of dichloromethylvinylsilane with 2,5‐diphenyl‐3,4‐(o,o′‐biphenylene)cyclopentadienone in a sealed tube. Poly [methylphenylsilylene‐co‐(2,9‐diphenyl‐7,8‐benzophenanthryl)methylsilylene] (PMBSI) was obtained by Wurtz‐type coupling of dichloromethylphenylsilane and 1 and was characterized with Fourier transform infrared, 1H‐NMR, 13C‐NMR, 29Si‐NMR, gel permeation chromatography, and ultraviolet and fluorescence spectroscopy. The conducting properties and thermal properties of the polymer were investigated. Because of the introduction of benzophenanthrene groups into the Si atoms of the polymer, the ultraviolet absorption wavelengths of the PMBSI redshifted significantly in the ultraviolet region, and a strong photoluminescence band could be observed in the visible region. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2445–2450, 2007
Microcrystallinity and colloidal peculiarities of UF/isocyanate hybrid resins
Authors: Wieland S. , Pizzi A. , Grigsby W. , Warnes J. , Pichelin F.
Published: February 2007

Combined mixtures of polymeric diphenylmethane diisocyanates (pMDI) with Urea‐formaldehyde‐resins (UF) adhesives for wood panels are shown (a) by X‐ray diffraction analysis (XRD) of the cured adhesive to present a certain percentage of microcrystallinity, this being due exclusively to the proportion of urea‐formaldehyde resin present in the mix and, (b) by polarized light optical microscopy (PLOM) to present colloidal structures in which oligomers and colloidal structures of one resin have migrated within the colloidal structures of the other resin. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2633–2636, 2007
Preparation and radar wave absorbing characterization of bicomponent fibers with infrared camouflage
Authors: Yu Bin , Qi Lu , Ye Jian‐zhong , Sun Hui
Published: February 2007

Sheath‐core bicomponent fibers were prepared by a general melt‐spinning method with polypropylene chips and various particles. The melt‐spun fibers were characterized by DSC and mass specific electrical resistance (MSER) apparatus. The electromagnetic constant was measured using a network analyzer and the absorbing wave effect was evaluated by an arch method. The results of the DSC thermogram indicated that the crystallinity of polypropylene containing particles in the core‐part slightly increased first and then kept steadily with the particles content increase. Nanoparticles in the sheath‐part did not make the crystallinity of fibers change markedly. The MSER of fibers rapidly decreased with the metal particles input. The complex permeability of fibers with Ba/Mn‐Zn ferrite was improved compared with that of fiber with single Mn‐Zn ferrite and the complex permittivity of fiber containing the 20 wt % Ba/Mn‐Zn ferrite increased with the increasing bronze content. The fibers filled with the Ba/Mn‐Zn ferrite and bronze particles had good radar absorbing effect. The input of Al particles in the sheath‐part of the fibers showed a limited effect on the radar wave absorbing properties of the fibers. The lowest infrared emissivity of the fibers including 15 wt % Al particles in sheath‐part reached 0.62. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2180–2186, 2007
Synthesis and swelling properties of grafting‐type and crosslinking‐type water‐swellable elastomers
Authors: He Peixin , Zhang Yuhong , Hu Rong
Published: February 2007

A grafting water‐swellable elastomer (WSE) that is, chlorinated polyethylene (CPE)‐graft‐poly(ethylene glycol) (PEG), was synthesized by a grafting reaction. The synthesis was based on the reaction between chlorine in CPE and sodium salt of PEG. PEG with molecular weights of 600 and 1000 were used. The maximum grafting percentage of the resulted copolymers after purification was 9.79%. The structure of the copolymer was confirmed by an IR spectrum. The grafting degree and PEG content increased with increasing reaction time and reaction temperature. The equilibrium swelling degree of the grafting copolymer was very small, only 16.94%. However, for the crosslinking WSE, the swelling degree was influenced by the absorbency temperature and absorbency time. The absorbency rate was faster than that of the grafting WSE, and the swelling degree in the equilibrium state was higher than that of the grafting WSE, too. The maximum swelling degree of the crosslinking WSE was 70%. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2637–2642, 2007
Experimental characterization of woven jute‐fabric‐reinforced isothalic polyester composites
Authors: Ahmed K. Sabeel , Vijayarangan S.
Published: February 2007

In this article, mechanical performance of isothalic polyester‐based untreated woven jute‐fabric composites subjected to various types of loading has been experimentally investigated. The laminates were prepared by hand lay‐up technique in a mold. Specimens for tests were fabricated as per ASTM standards. All the tests (except impact) were conducted on closed loop servo hydraulic MTS 810 material test system using data acquisition software Test Works‐II. From the results obtained, it was found that the tensile strength and tensile modulus of jute‐fabric composite are 83.96% and 118.97% greater than the tensile strength and modulus of unreinforced resin, respectively. The results of other properties, such as flexural, in‐plane shear, interlaminar shear, impact, etc., also revealed that the isothalic‐polyester‐based jute‐fabric composite have good mechanical properties and can be a potential material for use in medium load‐bearing applications. The failure mechanism and fiber‐matrix adhesion were analyzed by scanning electron microscope. Effects of long‐term immersion in water on mechanical properties are also presented. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2650–2662, 2007
Effect of intercalant content of mica on the various properties for the charged nanocomposite poly(N‐isopropyl acrylamide) hydrogels
Authors: Lee Wen‐Fu , Tsao Kai‐Tai
Published: February 2007

In this study, we intend to adjust the charge properties of the poly(N‐isopropylacrylamide) [Poly(NIPAAm)] gel by using anionic clay and cationic monomer. Hence, two series of nanocomposite hydrogels bearing different charges were designed from NIPAAm, intercalated mica (IM) (NIM‐series) and NIPAAm, IM, trimethyl (acrylamido propyl) ammonium iodide (TMAAI) (NTIM‐series), respectively. The mica was first intercalated with different contents of intercalant, trimethyl (acrylamido propyl) ammonium chloride (TMAACl), based on the cationic exchange capacity (CEC) of mica. The effect of the CEC value of IM and IM content on the charge property, swelling behaviors, mechanical properties, and drug‐release behaviors of the present gels were investigated. Results showed that the negative charges for NIM series gels decrease with increase in CEC values of the IM (from −11 to −6 mV), the positive charges for NTIM series gels also decrease with increase in CEC values of the IM (from +36 to +18 mV). The swelling behaviors and mechanical properties for the NTIM gels were significantly enhanced by IM content and CEC values of the IM. The microstructures, morphologies, and drug‐release behaviors in these two series gels are also investigated. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2277–2287, 2007
Surface modification of polyester and polyamide fabrics by low frequency plasma polymerization of acrylic acid
Authors: Cireli Aysun , Kutlu Bengi , Mutlu Mehmet
Published: February 2007

In this study, the surface characteristics of polyester and polyamide fabrics were changed by plasma polymerization technique utilizing acrylic acid as precursor. This monomer was used to produce hydrophilic materials with extended absorbency. The hydrophilicity, total wrinkle recovery angle (WRA°) and breaking strength of the fabrics were determined prior and after plasma polymerization treatment. The modification of surfaces was carried out at low pressure (<100 Pa) and low temperature (<50°C) plasma conditions. The effects of exposure time and discharge power parameters were optimized by comparing properties of the fabrics before and after plasma polymerization treatments. It was shown that two sides of polyester fabric samples were treated equally and homogeneously in plasma reactor. For polyester fabrics, the minimum wetting time, 0.5 s, was observed at two plasma processing parameters of 10 W–45 min and 10 W–20 min, where untreated fabric has a wetting time of 6 s. For polyester fabrics, the maximum value was obtained at 60 W–5 min with the wrinkle recovery angle of 306° where the untreated fabric has 290°. The optimum plasma conditions for polyamide fabrics were determined as 30 W–45 min where 2 s wetting time was observed. Wrinkle recovery angle of untreated polyamide fabric was 264°. In this study, after plasma polymerization of acrylic acid, wrinkle recovery angle values were increased by 13%. No significant change was observed in breaking strength of both fabrics after plasma treatment. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2318–2322, 2007
Variation of inhibited oxidation parameters in the range of phase transition
Authors: Kalinina I. G. , Gumargalieva K. Z. , Shlyapnikov Yu. A.
Published: February 2007

Parameters of inhibited oxidation of isotactic propylene containing antioxidant 2,2′‐methylene‐bis(4‐methyl‐6‐tertbutylphenol) have been studied in the temperature range 140–210°C. Unlike polyethylene, the dependencies of inhibited oxidation parameters of critical antioxidant concentration and of rate constant of antioxidant consumption change with temperature do not obey Arrhenius law both below and above the melting temperature. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2711–2713, 2007
Memory functions in polymer modified asphalts
Authors: Polacco Giovanni , Stastna Jiri , Michalica Peter , Biondi Dario , Cantù Matteo , Zanzotto Ludovit
Published: February 2007

The viscoelastic nonlinear behavior of several base and polymer modified asphalts (PMA) has been studied in step‐strain experiments. The polymers were poly(styrene‐b‐butadiene‐b‐styrene), poly(styrene‐b‐ethylene‐co‐butylene‐b‐styrene), poly(ethylene‐r‐vinylacetate) copolymers, and a linear low density poly(ethylene), which were chosen as representatives of the main categories of asphalt modifiers. Because of the complexity of the morphological structure of these materials, the relaxation modulus has only partial and qualitative similarities with that of melt or high concentrated solutions of entangled polymeric liquids. No time strain separability can be applied, and the relaxation experiments are conveniently described by means of the memory functions. These have been calculated both via a parametric fitting procedure and by interpolation algorithms. Results are presented, and a correlation between the PMA structure and the corresponding memory function is proposed for the investigated materials. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2330–2340, 2007
Investigation for surface morphology and mechanical property variations of single polymer particles
Authors: Ok Kim Dong , Hee Jin Jeong
Published: February 2007

Monodisperse polymer particles were prepared via one‐step seeded polymerization using polystyrene, poly(methyl methacrylate), or styrene/methyl methacrylate copolymer [poly(ST‐co‐MMA)] as seed particles and 1,6‐hexanedioldiacrylate or divinylbenzene as crosslinking monomer. For the study, the effects of the combination of seed polymer and crosslinking monomer, the ratio of the absorbed monomer to the seed polymer particles (swelling ratio: S/R), and the seeded polymerization rate on the variation of surface morphology and mechanical properties of polymer particles, such as recovery rate, K‐values, breaking strength, and breaking displacement were investigated by using microcompression test. It was observed that the surface morphology could be controlled by changing polymerization rate or combination of seed polymer and crosslinking monomer, and it had a great influence on mechanical properties, especially the breaking strength. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2350–2360, 2007
Effect of water‐contact on the roughness of patterned photoresist investigated by AFM analysis
Authors: Ahn Sung Il , Kim Jae Hyun , Zin Wang‐Cheol
Published: February 2007

The effect of water‐contact time on the roughness increment of patterned photoresist (AZ5214) was investigated by atomic force microscopy (AFM) analysis and the reason for the roughness increment was studied by the gravimetric experiment and the ellipsometry method. New method for calculating root‐mean‐square (RMS) line edge roughness from AFM data and the model of immersion lithography for experimentation were established. From the gravimetric experiments, it was confirmed that the diffusion of water into photoresist file is ruled my Fick's law. It was suggested that the amount of the roughness increment during rapid evaporation of water. As a result, the roughness of both the patterned line edge and the surface were proportioned in the root of water‐contact time at the initial time and it was the same as the results in previous gravimetric experiments. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2361–2365, 2007
Novel phenyl acetylene terminated poly(carborane‐silane): Synthesis, characterization, and thermal property
Authors: Zhou Quan , Mao Zuju , Ni Lizhong , Chen Jianding
Published: February 2007

Phenyl acetylene terminated poly(carborane‐silanec) (PACS) was synthesized by the couple reaction of methyldichlorosilane with 1,7‐dilithio‐m‐carborane and lithium phenylacetylide. The structure was characterized using FTIR, 1H‐NMR, 13C‐NMR, 29Si‐NMR, and gel permeation chromatography. PACS exhibits solubility in common organic solvents. Thermal and oxidative properties were evaluated by thermogravimetric analysis (TGA). Thermoset exhibits extremely thermal and oxidative property and TGA curves show that the temperature of 5% weight loss (Td5) is 762°C and char yield at 800°C is 94.2% in nitrogen. In air, surprisingly, both Td5 and char yield at 800°C show slight increase, which is greater than 800°C and 95.6%, respectively. After pyrolysis, the char has no additional weight loss up to 800°C in air. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2498–2503, 2007
Melting process and mechanism for vibration induced single‐screw extruder
Authors: Zeng Guang‐Sheng , Qu Jin‐Ping , Feng Yan‐Hong
Published: February 2007

The effect of a vibration force field on the melting process of an extruder is studied. It is shown that the mechanism for melting differs from conventional theory. Experimental studies of melting of low‐density polyethylene (LDPE) pellets in a vibration‐induced single‐screw (VISS) extruder show that melting is initiated on the inside of the barrel and the surface of screw. Models were developed that explain the melting mechanism in those regions. The melting at the surface of the screw is mainly initiated by frictional work on the pellets by the vibration and rotation of the screw. The melting action at the barrel is induced by a barrel temperature higher than the melting point and propagated by viscous dissipation heating of the melt film produced. The theory is supplemented by a calculation sample, which shows good agreement with experimental data obtained on a transparent barrel VISS (T‐VISS) extruder and a half‐open barrel VISS (H‐VISS) extruder with LDPE. The results of the experiment and calculation sample indicate that the introduction of vibration‐induced field can improve the melting capacity of extruder to a great extent. The present model enables the prediction of processing parameters for VISS extruders, from which the optimum operating conditions can be obtained. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2504–2514, 2007
Study on rubber blends: Influence of epoxidation on phase morphology and interphase
Authors: Rocha T. L. A. C. , Rosca C. , Schuster R. H. , Jacobi M. M.
Published: February 2007

A discussion about phase morphology and interphase is presented taking into account the influence of the epoxidation on NR/SBR blends. Unfilled blends were examined in a broad composition range to investigate the morphology by TEM (transmission electron microscopy) and to estimate the volume fraction of the interphase by means of DMA (dynamic mechanical analysis). It was observed that the domain sizes and the volume fraction of the interphase depend on the difference in polarity of rubbers caused by the presence of the epoxidized phase and the polarizability caused by the difference on the vinyl content. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2377–2384, 2007