bluuebunny/crossref_metadata_2025 huggingface dataset:
Regional seroprevalence of bluetongue virus in cattle in Illinois and western Indiana
Authors: Boyer Tim C. , Ward Michael P. , Wallace Richard L. , Singer Randall S.
Published: November 2007

Objective—To estimate seroprevalence of bluetongue virus (BTV) and the geographic distribution of seropositive cattle herds in Illinois and western Indiana.

Sample Population—10,585 serum samples obtained from cattle in 60 herds during 3 transmission seasons (2000 through 2002).

Procedures—In a longitudinal study, serum samples were tested for BTV antibodies by use of a competitive ELISA. Four geographic zones were created by use of mean minimum January temperature. A multivariable mixed-effects logistic regression model with a random effect for herd was used to estimate seropositive risk for zone, age of cattle, herd type, and transmission season.

Results—Overall, BTV antibodies were detected in 156 (1.5%) samples. Estimated seroprevalence in 2000, 2001, and 2002 was 1.49%, 0.97%, and 2.18%, respectively. Risk of being seropositive for BTV was associated with geographic zone and age. Seroprevalence increased progressively from northern to southern zones, with no evidence of BTV infection in the northernmost zone. In the southernmost zone, annual seroprevalence ranged from 8.65% to 11.00%. Adult cattle were 2.35 times as likely as juvenile cattle to be seropositive.

Conclusions and Clinical Relevance—Overall seroprevalence was lower than has been reported for Illinois cattle. Bluetongue virus antibodies were distributed heterogeneously in this region. Only in the southernmost zone was seroprevalence consistently > 2%. Regionalization of BTV risk based on state borders does not account for such variability. Serologic data could be combined with landscape, climate, and vector data to develop predictive models of BTV risk within transitional regions of the United States.
Effect of exercise on development of capillary supply and oxidative capacity in skeletal muscle of horses
Authors: Rietbroek Nancy J. , Dingboom Elizabeth G. , Schuurman Simon O. , Hengeveld-van der Wiel Ellen , Eizema Karin , Everts Maria E.
Published: November 2007

Objective—To determine whether postnatal development of oxidative capacity and capillary supply of skeletal muscle is affected by various movement regimens in horses.

Animals—35 foals.

Procedures—Dutch Warmblood foals were allocated into 3 groups (box stall rest, box stall rest with training, and free pasture exercise). Training comprised an increasing number of gallop sprints from 1 week after birth to 22 weeks of age. From 22 to 48 weeks, the 3 groups were combined and allowed to exercise freely. Capillary supply (diffusion index [ie, area supplied by 1 capillary]), citrate synthase (CS) activity, and succinate dehydrogenase (SDH) activity were measured in biopsy specimens of deep gluteus medius muscle.

Results—During the first 22 weeks, diffusion index increased in all 3 groups (the training and pasture groups had a smaller increase, compared with the box stall rest group), total SDH activity increased in the training and pasture groups and decreased in the box stall rest group, and CS activity decreased in all groups. The effect of the various movement regimens on the diffusion index remained after the groups were combined.

Conclusions and Clinical Relevance—Withholding of exercise had a negative effect on the capillary supply (ie, diffusion index increased) that remained after box stall rest was discontinued and on oxidative capacity. Box stall rest with training prevented the negative effects and eventually had the same positive effect as pasture exercise.
Evaluation of a novel immunomodulator composed of human chorionic gonadotropin and bacillus Calmette-Guerin for treatment of canine mast cell tumors in clinically affected dogs
Authors: Henry Carolyn J. , Downing Sue , Rosenthal Robert C. , Klein Mary Kay , Meleo Karri , Villamil J. Armando , Fineman Linda S. , McCaw Dudley L. , Higginbotham Mary Lynn , McMichael John
Published: November 2007

Objective—To evaluate safety and efficacy of LDI-100, a preparation containing human chorionic gonadotropin (hCG) and bacillus Calmette-Guerin (BCG), in the treatment of dogs with mast cell tumors and to compare results with those from a control group receiving single-agent vinblastine.

Animals—95 dogs with measurable grade II or III mast cell tumors.

Procedures—Dogs were randomized to receive either LDI-100 (1.35 ng of BCG and 2 units of hCG, SC, q 24 h) or vinblastine (2 mg/m2, IV, q 1 wk) for 6 weeks. Tumors were measured at baseline and day 42, and dogs were monitored for signs of toxicosis. Clinical performance scores were recorded at each visit. Differences in host factors (sex, weight, and age), clinical performance score, tumor response, and adverse events were analyzed.

Results—46 dogs received LDI-100, and 49 dogs received vinblastine. No significant differences were found between the 2 treatment groups with regard to host factors or clinical performance score. Tumor response (≥50% reduction) rates were similar between the LDI-100 and vinblastine group (28.6% and 11.7%, respectively). Dogs in the LDI-100 group had significantly less neutropenia than the vinblastine group.

Conclusions and Clinical Relevance—hCG and BCG have immunomodulatory and antitumor effects against a variety of malignancies in humans and dogs. In this study, LDI-100 provided clinical responses comparable to single-agent vinblastine chemotherapy but without myelosuppression. LDI-100 is a promising new agent that should be further investigated for multimodality therapy of mast cell tumors in dogs.
Use of computed tomography to evaluate pathologic changes in the lungs of calves with experimentally induced respiratory tract disease
Authors: Lubbers Brian V. , Apley Michael D. , Coetzee Johann F. , Mosier Derek A. , Biller David S. , Mason Diane E. , Henao-Guerrero Piedad Natalia
Published: November 2007

Objective—To optimize methods for the use of computed tomography (CT) to assess pathologic changes in the lungs of calves and to determine the effect of treatment on lung consolidation.

Animals—10 male Holstein calves.

Procedures—Calves were anesthetized to facilitate CT imaging of the thorax. After initial images were obtained, pneumonia was induced in the calves by inoculation through a bronchoscope. Two calves were used in a preliminary study to refine the inoculation dose and optimize CT images. Four calves were administered florfenicol and 4 calves were untreated control animals. Serial images were obtained 24, 48, and 72 hours after inoculation. After final images were obtained, calves were euthanized, and lung consolidation was estimated by use of lung surface area scoring and water displacement. These estimates were compared with estimated lung consolidation obtained by use of CT.

Results—Calves had rapid disease progression. Percentage of lung consolidation was not significantly different between treatment groups for any of the estimation methods. Results of an ANOVA of the 3 assessment methods indicated significant differences among methods. Estimates of the percentage of lung consolidation obtained by use of surface area scoring and CT correlated well, whereas water displacement estimates correlated poorly with other methods of consolidation estimation.

Conclusions and Clinical Relevance—Because of the correlation with other methods for estimation of lung consolidation, CT has the potential to be used to monitor disease progression in calves with experimentally induced respiratory tract disease.
Use of vascular access ports in femoral veins of dogs and cats with cancer
Authors: Cahalane Alane Kosanovich , Rassnick Kenneth M. , Flanders James A.
Published: November 2007

Objective—To evaluate long-term function of vascular access ports (VAPs) implanted in the femoral vein of dogs and cats undergoing cancer treatment.

Design—Prospective clinical study.

Animals—3 dogs and 6 cats treated via chemotherapy or radiation.

Procedures—VAPs were surgically implanted in the left femoral vein of 3 dogs and 6 cats over a 1-year period. Injection port location was alternated to either a caudal thoracic or ilial location in each patient. Duration of VAP function, ease of infusion, and ease of aspiration through the VAPs were recorded, and associated complications were assessed at each VAP use. Client satisfaction with VAP placement was evaluated by use of a questionnaire.

Results—Primary uses of the VAPs included blood sampling and delivering sedative or chemotherapeutic drugs. Median duration of successful infusion was 147 days (range, 60 to 370 days), and median duration of successful aspiration was 117 days (range, 10 to 271 days). The frequency of signs of VAP-related discomfort was low (7% of patient observations). Clients were satisfied with their decision to use VAPs. Complications included partial (n = 7) or complete (2) VAP occlusion, port migration (1), and presumptive infection (1).

Conclusions and Clinical Relevance—Results suggested that VAP implantation into the femoral vein provides an acceptable means of chronic venous access in dogs and cats undergoing cancer treatment.
Endoscopic removal of a molariform supernumerary intranasal tooth (heterotopic polyodontia) in a horse
Authors: de Mira Monica C. , Ragle Claude A. , Gablehouse Kristin B. , Tucker Russell L.
Published: November 2007

Case Description—A 3-year-old Thoroughbred mare was evaluated because of abnormal upper respiratory tract sounds (that had become apparent during race training) of 3- to 4- months' duration.

Clinical Findings—On initial physical evaluation, there were no abnormal findings. During trotting, an abnormal upper airway expiratory sound was audible. Endoscopic examination revealed a small mass protruding into the right ventral nasal meatus. Radiographic images of the skull revealed no abnormal findings. Computed tomography of the head revealed an abnormal structure in the same location as the mass that was observed during endoscopy. The x-ray attenuation of the mass was identical to that of dental tissue.

Treatment and Outcome—The mass was surgically removed with endoscopic guidance. On gross examination, the excised mass appeared to be a nearly normal molariform tooth. Histologic examination revealed that it was a well-formed tooth, with no other associated cellular populations. The mass was determined to be a molariform supernumerary intranasal tooth. Six months following discharge from the hospital, the trainer reported that the abnormal respiratory tract sound was no longer audible. During a follow-up endoscopic examination performed at the training facility, no abnormalities were detected.

Clinical Relevance—In horses, an intranasal tooth should be considered as a differential diagnosis for expiratory stridor. Clear definitions of heterotopic polyodontia, dentigerous cyst, and temporal teratoma can be used to clinically diagnose these separate anomalies. In the horse of this report, computed tomographic findings contributed to determination of a diagnosis and formulation of a treatment plan.
Outcome of medical and surgical treatment of cecal impaction in horses: 114 cases (1994–2004)
Authors: Plummer Amy E. , Rakestraw Peter C. , Hardy Joanne , Lee Ryan M.
Published: November 2007

Objective—To determine short- and long-term outcomes, including recurrence rates, for horses with cecal impaction treated medically or surgically.

Design—Retrospective case series.

Animals—114 horses.

Procedures—Medical records were reviewed for information on signalment, history, clinical findings, treatment (medical vs surgical), and short-term outcome. Information on longterm outcome was obtained through a mail survey and telephone interview with owners.

Results—54 horses were treated medically, 49 horses were treated surgically, and 11 horses were euthanized after initial examination without further treatment. Horses treated surgically were significantly more likely to have signs of moderate or severe pain than were horses treated medically. Forty-four of the 54 (81%) horses treated medically were discharged from the hospital. Twelve of the 49 horses treated surgically were euthanized at surgery because of cecal rupture. Thirty-five of the 37 (95%) horses that were allowed to recover from surgery were discharged from the hospital. In 34 horses treated surgically, typhlotomy without a bypass procedure was performed. Long-term (≥ 1 year) follow-up information was available for 19 horses treated medically and 28 horses treated surgically. Eighteen (95%) and 25 (89%) of the horses, respectively, were alive at least 1 year after treatment.

Conclusions and Clinical Relevance—Results suggested that medical and surgical treatment were both associated with favorable outcomes in horses with cecal impactions. In this population, typhlotomy alone without cecal bypass was associated with a low recurrence rate. The long-term prognosis for horses that were discharged from the hospital was good.
Effect of twin birth calvings on milk production, reproductive performance, and survival of lactating cows
Authors: Bicalho Rodrigo C. , Cheong Soon Hon , Galvão Klibs N. , Warnick Lorin D. , Guard Charles L.
Published: November 2007

Objective—To evaluate effect of twin birth calvings on milk production, reproductive performance, and survival of lactating cows.

Design—Retrospective observational cohort study.

Animals—33,868 cows from 20 farms.

Procedures—Data on age at calving for primiparous cows and mature equivalent milk yield for multiparous cows, assistance at calving, stillbirths, twin births, gestation duration, pregnancy at the end of the data collection period, and culling-death for all cows were extracted from farm computer records and used for statistical analysis.

Results—Prevalence of twin parturitions was 1.3% (159/12,050) and 6.5% (1,410/21,818) for primiparous and multiparous cows, respectively. Primiparous and multiparous cows with singletons produced more milk than cows with live twins or at least 1 dead twin (primiparous, 33.1 vs 31.9 vs 31.2; multiparous, 36.5 vs 35.7 vs 35.0). Multiparous cows with dead twins produced less milk than cows with live twins. Compared with dams with singleton birth, cows with twins were 0.78 times as likely to conceive and 1.42 times as likely to die or be culled. Cows with dead twins also had increased time to conception, compared with live twins.

Conclusions and Clinical Relevance—Twin birth was associated with decreased survival, milk production, and reproductive performance. Having at least 1 dead twin was even more detrimental than having live twins and resulted in decreased milk production and reproductive performance of lactating cows.
Metallopolymers: New Multifunctional Materials
Authors: Whittell G. R. , Manners I.
Published: November 2007

Since the mid 1990s soluble, well‐characterized high molecular weight metal‐containing and metallosupramolecular polymers have become readily available for the first time, even in some cases, with narrow molecular weight distributions and controlled architectures such as block copolymers. This has led to a rapidly expanding interest in their properties and uses. The review provides a survey of the range of applications for these new materials, which combine the processing advantages of polymers with the functionality provided by the presence of metal centers.
Derivation, simulation and validation of a cohesive particle flow CFD model
Authors: van Wachem Berend , Sasic Srdjan
Published: November 2007

A comprehensive physical model describing the agglomeration behavior present during fluidization of fine powders is still missing in literature. A model of balance of forces acting on a single solid particle is introduced, aiming at predicting and locally estimating the size of the agglomerates created in the bed. Computational fluid dynamics (CFD) have been used to investigate the hydrodynamics of a gas‐solid fluidized bed operated with particles belonging to group A of Geldart classification.1 The key issue is that, in the gas and particle flow field, both hydrodynamic and interparticle forces are of importance. The model is incorporated into simulations based on an Eulerian approach and using the kinetic theory of granular flow. In the simulations, the closure models describing the hydrodynamics of the solids phase are directly affected by the behavior of the agglomerates. No empirical data or parameters were used to close the model. The simulations are compared with experiments of an independent research group, through the time‐averaged solids volume fraction in a fluidized bed operated at different gas velocities. The agreement obtained between the simulation results and data from the literature is very good. Also, it is shown that, under flow conditions treated in this work, agglomerates of size of several single particle diameters are present in the fluidized bed. © 2007 American Institute of Chemical Engineers AIChE J, 2008
Historical hematology: May–Hegglin anomaly
Authors: Saito Hidehiko , Kunishima Shinji
Published: November 2007

May–Hegglin anomaly is a rare autosomal dominant platelet disorder characterized by thrombocytopenia, giant platelets, and unique leukocyte inclusion bodies. This disorder was first described by May, a German physician, in 1909, and was subsequently described by a Swiss physician, Hegglin, in 1945. The pathogenesis of the disorder had been unknown until recently, when mutations in the gene encoding for nonmuscle myosin heavy chain IIA (MYH9) were identified. Unique cytoplasmic inclusion bodies are aggregates of nonmuscle myosin heavy chain IIA, and are only present in granulocytes. It is not yet known why inclusion bodies are not present in platelets, monocytes, and lymphocytes, or how giant platelets are formed. Interestingly, MYH9 is also found to be responsible for several related disorders with macrothrombocytopenia and leukocytes inclusion, including Sebastian, Fechtner, and Epstein syndromes, which feature deafness, nephritis, and/or cataract. Current interest is centered upon the mechanisms by which a single mutation causes a variety of phenotypes. Am. J. Hematol., 2008. © 2007 Wiley‐Liss, Inc.
22q13 microduplication in two patients with common clinical manifestations: A recognizable syndrome?
Authors: Okamoto Nobuhiko , Kubota Takeo , Nakamura Yutaka , Murakami Ryusuke , Nishikubo Toshiya , Tanaka Ichiro , Takahashi Yukihiro , Hayashi Shin , Imoto Issei , Inazawa Johji , Hosokai Noboru , Kohsaka Shinichi , Uchino Shigeo
Published: November 2007

We report here on two unrelated patients (Patients 1 and 2) with a cryptic microduplication involving a 22q13 segment. Both patients manifested infantile hypotonia, developmental delay, and growth deficiency. In addition, an abnormal signal intensity area was detected in the frontal white matter of Patient 2 by brain MRI. Whole‐genome microarray comparative genomic hybridization for Patient 1 and fluorescence in situ hybridization analysis with 22q‐subtelomeric probes performed in both patients showed a submicroscopic 22q13 duplication that involved the SHANK3 gene. The duplication in Patient 1 was de novo type, while that in Patient 2 was derived from a familial 17;22 translocation. The presence of common clinical manifestations in the two patients with the common duplicated region led to a conclusion that 22q terminal duplication is a recognizable clinical entity, that is, the 22q13 microduplication syndrome. © 2007 Wiley‐Liss, Inc.
Cerebro‐oculo‐nasal syndrome: 13 new Brazilian cases
Authors: Guion‐Almeida Maria Leine , Zechi‐Ceide Roseli Maria , Richieri‐Costa Antonio
Published: November 2007

Cerebro‐oculo‐nasal syndrome (CONS) is characterized by structural anomalies of the central nervous system (encephalocele, ventricular dilatation, defects of corpus callosum, and even holoprosencephaly in one instance), by ocular alterations ranging from anophthalmia/microphthalmia to normal eyes, and by proboscis‐like nares. Here, we report on 13 new cases with CONS, review 7 previously published cases, and evaluate the findings in all 20 patients. Despite marked variability among cases, the nasal configuration appears to be unique and diagnostic. Although one patient had a mutation in the PTCH gene, the cause of all other cases remains unknown to date. © 2007 Wiley‐Liss, Inc.
Temperature control of a pilot plant reactor system using a genetic algorithm model‐based control approach
Authors: Khairi Abdul Wahab Ahmad , Azlan Hussain Mohamed , Omar Rosli
Published: November 2007

The work described in this paper aims at exploring the use of an artificial intelligence technique, i.e. genetic algorithm (GA), for designing an optimal model‐based controller to regulate the temperature of a reactor. GA is utilized to identify the best control action for the system by creating possible solutions and thereby to propose the correct control action to the reactor system. This value is then used as the set point for the closed loop control system of the heat exchanger. A continuous stirred tank reactor is chosen as a case study, where the controller is then tested with multiple set‐point tracking and changes in its parameters. The GA model‐based control (GAMBC) is then implemented experimentally to control the reactor temperature of a pilot plant, where an irreversible exothermic chemical reaction is simulated by using the calculated steam flow rate. The dynamic behavior of the pilot plant reactor during the online control studies is highlighted, and comparison with the conventional tuned proportional integral derivative (PID) is presented. It is found that both controllers are able to control the process with comparable performance. Copyright © 2007 Curtin University of Technology and John Wiley & Sons, Ltd.
Thermal and dynamic mechanical properties of organic–inorganic hybrid composites of itaconate‐containing poly(butylene succinate) and methacrylate‐substituted polysilsesquioxane
Authors: Sakuma Takenori , Kumagai Atsushi , Teramoto Naozumi , Shibata Mitsuhiro
Published: November 2007

Itaconate‐unit‐containing poly(butylene succinate) (PBSI) was synthesized by the reaction of 1,4‐butanediol, succinic acid, and itaconic acid in a molar ratio of 2.0 : 1.0 : 1.0, and the obtained PBSI was reacted with methacryl‐group‐substituted polysilsesquioxane (ME‐PSQ) in the presence of benzoyl peroxide (BPO) at 130°C to produce PBSI/ME‐PSQ hybrid composites. The thermal and dynamic mechanical properties of the PBSI/ME‐PSQ hybrid composites were investigated in comparison with those of PBSI cured at 130°C in the presence of BPO. As a result, the hybrid composites showed a much higher thermal degradation temperature and storage modulus in the rubbery state than the cured PBSI (C‐PBSI). The thermal degradation temperature and storage modulus of the hybrid composites increased with increasing ME‐PSQ content. The glass‐transition temperature, measured by dynamic mechanical analysis of the hybrid composites, somewhat increased with increasing ME‐PSQ content. However, the glass‐transition temperatures of all the hybrid composites were lower than that of C‐PBSI. Although the IR absorption peak related to CC groups was not detected for C‐PBSI, some olefinic absorption peaks remained for all the hybrid composites. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Production of macroporous resins for heavy‐metal removal. I. Nonfunctionalized polymers
Authors: Ortiz‐Palacios Jesús , Cardoso Judith , Manero Octavio
Published: November 2007

The aim of this work was the synthesis of macroporous resins with large specific surface areas through the use of organic solvents (known as porogens or pore‐forming agents) for applications in hexavalent chromium (Cr+6) removal operations. The synthesis of these materials by suspension polymerization allowed the generation of macroporous structures. The comonomers 4‐vinylpyridine and divinylbenzene were considered in different ratios. Poly(vinyl alcohol) was used as a suspension agent in a mixture of toluene and hexane. The materials produced were characterized with Fourier transform infrared spectroscopy, elemental analysis, thermogravimetry, nitrogen adsorption, and scanning electron microscopy. The macroporous resin with the largest surface area (130 m2/g) was thermally stable up to 300°C and had a structure that included spherical domains with a mean diameter of 68 μm, uniform porosity, and expected high sorption capability. The sorption properties of the resins were evaluated for applications in water‐treatment operations to eliminate Cr+6 ions at a pH near 7. The advantages of these materials were their high removal capability, high selectivity, and fast adsorption kinetics at a pH 6.5. An aqueous solution of 4 ppm K2Cr2O7 was used to quantify the Cr+6 content by ultraviolet–visible spectroscopy. A remarkable sorption level (94%) of chromate ions (Cr+6) was obtained during a 15‐h period for the resin with the highest pyridine group content. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008
Potentiometric studies of oxidation–reduction reactions with redox copolymers
Authors: Bogoczek Romuald , Kociołek‐Balawejder Elżbieta , Stanisławska Ewa
Published: November 2007

Polymeric oxidants in the bead form that were macroporous styrene/divinylbenzene copolymers containing N‐chlorosulfonamide functional groups (in sodium or hydrogen form) or N‐bromosulfonamide groups (in sodium form) were synthesized and investigated to determine their oxidizing powers. The redox potentials of the N‐chlorosulfonamide/sulfonamide and N‐bromosulfonamide/sulfonamide systems were determined by potentiometric studies at different pH values with aqueous solutions of Na2SO3, KCN, and KSCN as reducers. The formal redox potentials of the N‐chlorosulfonamide copolymers were 0.79, 0.44, and −0.12 V at pH's of 1.8, 8.45, and 13.6, respectively. The formal redox potential of the N‐bromosulfonamide copolymer was about 100 mV higher in comparable conditions and in solutions over pH = 5 (e.g., 0.56 V at pH = 8.56). The comparatively higher oxidizing power of the N‐bromosulfonamide copolymer was particularly evident in a strong alkaline medium (in which the N‐chlorosulfonamide copolymer was not reactive). In contrast, the N‐chlorosulfonamide copolymer showed strong oxidative properties in acidic media (in which the N‐bromosulfonamide copolymer decomposed itself). © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008
Performance studies of phosphate‐doped polyaniline containing paint coating for corrosion protection of aluminium alloy
Authors: Sathiyanarayanan S. , Syed Azim S. , Venkatachari G.
Published: November 2007

Polyaniline‐phosphate polymer was prepared chemically by oxidation polymerization of aniline in phosphoric acid medium using ammonium persulphate. The PANI‐phosphate polymer was characterized by FTIR, XRD, and SEM. The paints using PANI‐phosphate as pigment in acrylic and epoxy binder were prepared. The protective performance of the coating formed on aluminum alloy AA 2024 T3 was studied by electrochemical impedance spectroscopy in 0.5% NaCl solution. Both the coating systems have exhibited the coating resistance values above 1M Ω cm2 even after 50‐days exposure in 0.5% NaCl solution. Besides the anticorrosion performance of PANI‐containing coating is comparable with that of chromate‐containing coating. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Improving mechanical performance of injection molded PLA by controlling crystallinity
Authors: Harris Angela M. , Lee Ellen C.
Published: November 2007

Currently, use of poly(lactic acid) (PLA) for injection molded articles is limited for commercial applications because PLA has a slow crystallization rate when compared with many other thermoplastics as well as standard injection molding cycle times. The overall crystallization rate and final crystallinity of PLA were controlled by the addition of physical nucleating agents as well as optimization of injection molding processing conditions. Talc and ethylene bis‐stearamide (EBS) nucleating agents both showed dramatic increases in crystallization rate and final crystalline content as indicated by isothermal and nonisothermal crystallization measurements. Isothermal crystallization half‐times were found to decrease nearly 65‐fold by the addition of only 2% talc. Process changes also had a significant effect on the final crystallinity of molded neat PLA, which was shown to increase from 5 to 42%. The combination of nucleating agents and process optimization not only resulted in an increase in final injection molded crystallinity level, but also allowed for a decreased processing time. An increase of over 30°C in the heat distortion temperature and improved strength and modulus by upwards of 25% were achieved through these material and process changes. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Polyurethanes with monodisperse rigid segments based on a diamine–diamide chain extender
Authors: Biemond G. J. E. , Braspenning K. , Gaymans R. J.
Published: November 2007

Polyether(bisurethane‐bisurea‐bisamide)s (PEUUA) based on poly(tetramethylene oxide) (PTMO) were synthesized by chain extension of PTMO endcapped with a diisocyanate (DI), and a diamine–diamide extender. The prepolymers were PTMOs with molecular weights between 1270 and 2200 g mol−1, either endcapped with 4,4′‐diphenylmethane diisocyanate (MDI), 2,4‐toluene diisocyanate (2,4‐TDI), or 1,6‐hexane diisocyante (HDI) and with a low content of free diisocyanate (<0.1 wt %). The diamine–diamide (6A6) extender was based on hexamethylene diamine (6) and adipic acid (A). In this way, segmented polyurethanes with monodisperse rigid segments (DI‐6A6‐DI) were obtained. The PEUUAs were characterized by DSC as well as temperature‐dependent FTIR and DMTA. The mechanical properties of the polymers were evaluated by compression set and tensile test measurements. The polyurethanes with monodisperse rigid segments displayed low glass transition temperatures, almost temperature‐independent rubbery plateaus and sharp melting temperatures. The crystallinities of the hard segments were 70–80% upon heating and 40–60% upon cooling. The rate of crystallization was moderately fast as the supercooling (Tm − Tc) was in the order 36–54°C. The polyurethanes based on HDI had a much higher rubber modulus as compared to the MDI and 2,4‐TDI‐based polymers, because of a higher degree of crystallinity and/or a higher aspect ratio of the crystallites. The HDI residues are flexible and not sterically hindered and could therefore be more easily packed than MDI or 2,4‐TDI residues. Polyurethanes with monodisperse DI‐6A6‐DI hard segments have interesting properties. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Gelation of methylcellulose hydrogels under isothermal conditions
Authors: Joshi S. C. , Su J. C. , Liang C. M. , Lam Y. C.
Published: November 2007

The current work deals with the gelation of methylcellulose (MC) in aqueous solutions under isothermal conditions. The isothermal gelation was monitored during two consecutive heating and cooling cycles. The gelation was observed to occur early during the second cycle and progress at a higher rate. Micelle‐like structures were found to form in MC solutions during the first gelation cycle. These were largely responsible for the accelerated gelation during the second heating cycle. The influence from the state of water was examined by studying the gelation phenomenon for MC using either cold or hot DI water as solvent. The possible mechanism involved is discussed. A gel indexing method was established to provide a quantitative measure for the state of gelation achievable using different MC concentrations with either cold or hot water solvent. Stabilization kinetics for the gel under isothermal conditions was described using the Malkin and Kulichikhin model. The kinetics parameters were determined. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Light‐triggered reversible solubility of α‐cyclodextrin and azobenzene moiety complexes in PDMAA‐co‐PAPA via molecular recognition
Authors: Luo Chunhua , Zuo Fang , Ding Xiaobin , Zheng Zhaohui , Cheng Xu , Peng Yuxing
Published: November 2007

Photoresponsive polymer with azobenzene pendant group (PDMAA‐co‐PAPA) was synthesized by radical polymerization of N,N‐dimethylacrylamide (DMAA) and N‐4‐phenylazophenyl acrylamide (PAPA), and the characterization of the inclusion complexes of the PDMAA‐co‐PAPA with α‐cyclodextrin (α‐CD) were performed by FTIR, GPC, 1H NMR, 2D NOESY, and UV–vis spectroscopy. It was found that the solubility of PDMAA‐co‐PAPA and α‐CD inclusion complexes in aqueous solution showed tunable property, which could be triggered by alternating UV–vis light irradiation at a certain temperature due to the effect of molecular recognition of α‐CD with azobenzene moiety in the polymer. After UV irradiation, the lower critical solution temperature (LCST) of the polymer aqueous solution increased slightly without α‐CD while the LCST decreased sharply at presence of α‐CD. Furthermore, UV spectroscopy showed that the photoisomerization of the polymer solution went on rapidly and reversibly, and 2D NOESY data suggested that the inclusion complexation of α‐CD with trans azobenzene moiety and the decomplexation with cis azobenzene resulted in reversible solubility behavior when objected to UV and Vis light irradiation alternately. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Coarse‐grained lattice model simulations of sequence‐structure fitness of a ribosome‐inactivating protein
Authors: Olson Mark A. , Yeh In‐Chul , Lee Michael S.
Published: November 2007

Many realistic protein‐engineering design problems extend beyond the computational limits of what is considered practical when applying all‐atom molecular‐dynamics simulation methods. Lattice models provide computationally robust alternatives, yet most are regarded as too simplistic to accurately capture the details of complex designs. We revisit a coarse‐grained lattice simulation model and demonstrate that a multiresolution modeling approach of reconstructing all‐atom structures from lattice chains is of sufficient accuracy to resolve the comparability of sequence‐structure modifications of the ricin A‐chain (RTA) protein fold. For a modeled structure, the unfolding–folding transition temperature was calculated from the heat capacity using either the potential energy from the lattice model or the all‐atom CHARMM19 force‐field plus a generalized Born solvent approximation. We found, that despite the low‐resolution modeling of conformational states, the potential energy functions were capable of detecting the relative change in the thermodynamic transition temperature that distinguishes between a protein design and the native RTA fold in excellent accord with reported experimental studies of thermal denaturation. A discussion is provided of different sequences fitted to the RTA fold and a possible unfolding model. © 2007 Wiley Periodicals, Inc. Biopolymers 89: 153–159, 2008.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Analysis of structural changes in normal and aneurismal human aortic tissues using FTIR microscopy
Authors: Rubin S. , Bonnier F. , Sandt C. , Ventéo L. , Pluot M. , Baehrel B. , Manfait M. , Sockalingum G. D.
Published: November 2007

Aortic aneurisms are frequently asymptomatic but can induce dramatic complications. The diagnosis is only based on the aortic diameter and not on a structural and compositional basis. In this preliminary study, we propose infrared microspectroscopy to nondestructively probe normal and aneurismal human aortas. Spectra from 19 human ascending aortic biopsies (10 normal and 9 aneurismal) were acquired using infrared microspectroscopy. A 1500 × 150 μm2 area of each 7‐μm thick cryosection was investigated using a 30‐μm spatial resolution with a total of about 200 spectra per sample. Spectral differences between normal and aneurismal tissues were mainly located in spectral regions related to proteins, such as elastin and collagen, and proteoglycans (1750–1000 cm−1). Tissue heterogeneity and sample classification have been evaluated using hierarchical cluster analysis of individual or mean spectra and their second derivative. Using spectral range related to proteins, 100% of good classification was obtained whereas the proteoglycan spectral range was less discriminant. This in vitro study demonstrates the potential of such technique to differentiate between normal and aneurismal aortas using selected spectral ranges. Future investigations will be focused on these specific spectral regions to determine the role of elastin and collagen in the discrimination of normal and pathological aortas. © 2007 Wiley Periodicals, Inc. Biopolymers 89: 160–169, 2008.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Contrast‐induced nephropathy
Authors: Pucelikova Tereza , Dangas George , Mehran Roxana
Published: November 2007

Contrast induced nephropathy (CIN) is an iatrogenic disorder, resulting from exposure to contrast media. Contrast‐induced hemodynamic and direct cytotoxic effects on renal structures are highly evident in its pathogenesis, whereas other mechanisms are still poorly understood. CIN is typically defined as an increase in serum creatinine by either ≥0.5 mg/dl or by ≥25% from baseline within the first 2–3 days after contrast administration. Although rare in the general population, CIN has a high incidence in patients with an underlying renal disorder, in diabetics, and the elderly. The risk factors are synergistic in their ability to produce CIN. The best way to prevent CIN is to identify the patients at risk and to provide adequate peri‐procedural hydration. The role of various drugs in prevention of CIN is still controversial and warrants future studies. Despite remaining uncertainty regarding the degree of nephrotoxicity produced by various contrast agents, in current practice non‐ionic low‐osmolar contrast media are preferred over the high‐osmolar contrast media in patients with renal impairment. © 2007 Wiley‐Liss, Inc.
Rheolytic mechanical thrombectomy for pulmonary artery thrombus in children with complex cyanotic congenital heart disease
Authors: Menon Shaji C. , Hagler Donald J. , Cetta Frank , Cabalka Allison K.
Published: November 2007

Acute thrombosis of the pulmonary arteries (PA) can occur during operative or catheter based interventions. This may have serious consequences especially in patients with palliated single ventricle physiology. Traditional therapy for PA thrombosis includes use of local or systemic thrombolytic therapy and surgical thrombectomy. Percutaneous transcatheter mechanical thrombectomy can be broadly divided into three categories based on their mechanisms of action: (a) mechanical fragmentation of the embolus using guide‐wires, pigtail catheters, or balloons (flossing technique), (b) extraction using cup or basket devices, or (c) hydrodynamic fragmentation and aspiration of the embolus. Rheolytic thrombectomy using AngioJet system (Possis Medical, Minneapolis, MN) uses hydrodynamic thrombus fragmentation and aspiration technique, and provides an alternative solution in management of acute thrombosis. We report three patients with complex congenital heart disease of single ventricle physiology palliated by cavopulmonary anastomosis or central shunts and PA thrombosis treated with AngioJet system. © 2008 Wiley‐Liss, Inc.
On the free boundary problem of three‐dimensional incompressible Euler equations
Authors: Zhang Ping , Zhang Zhifei
Published: November 2007

In this paper, we consider in three dimensions the motion of a general inviscid, incompressible fluid with a free interface that separates the fluid region from the vacuum. We assume that the fluid region is below the vacuum and that there is no surface tension on the free surface. Then we prove the local well‐posedness of the free boundary problem in Sobolev space provided that there is no self‐intersection point on the initial surface and under the stability assumption that ${{\partial p}\over {\partial {\bf n}}}(\xi)|_{t=0}\leq -2c_{0}<0$ with ξ being restricted to the initial surface. © 2007 Wiley Periodicals, Inc.
Rat pancreatic islet is formed by unification of multiple endocrine cell clusters
Authors: Hara Akemi , Kadoya Yuichi , Kojima Itaru , Yamashina Shohei
Published: November 2007

The organogenesis of islets in rat pancreas was studied by three‐dimensional reconstructions from serial section micrographs. On embryonic day (E) 12, an endocrine cluster consisting mainly of glucagon‐expressing cells maintained connection with the pancreatic endoderm at several regions. On E15–E17, the cluster enlarged by fusion of newly formed buds. Although the proportion of insulin‐expressing cells increased, they were located in the periphery of the cluster. On the day of birth, insulin‐expressing cell clusters enlarged and fused to form several cores within the islet. The glucagon‐expressing cell mass expanded to form a thin mantle covering the cores. During islet organogenesis, proliferation activity was high in the exocrine duct system. Moreover, the endocrine cell clusters maintained contact with the duct epithelium throughout. We conclude that the pancreatic islet is generated by the unification of multiple endocrine clusters originated from separate regions of the duct system. The mechanism of mantle–core formation is discussed. Developmental Dynamics 236:3451–3458, 2007. © 2007 Wiley‐Liss, Inc.
Output‐only structural identification in time domain: Numerical and experimental studies
Authors: Perry M. J. , Koh C. G.
Published: November 2007

By identifying changes in stiffness parameters, structural damage can be detected and monitored. Although considerable progress has been made in this research area, many challenges remain in achieving robust structural identification based on incomplete and noisy measurement signals. The identification task is made even more difficult if measurement of input force is to be eliminated. To this end, an output‐only structural identification strategy is proposed to identify unknown stiffness and damping parameters. A non‐classical approach based on genetic algorithms (GAs) is adopted. The proposed strategy makes use of the recently developed GA‐based method of search space reduction, which has shown to be able to accurately and reliably identify structural parameters from measured input and output signals. By modifying the numerical integration scheme, input can be computed as the parameter identification task is in progress, thereby eliminating the need to measure forces. Numerical and experimental results demonstrate the power of the strategy in accurate and efficient identification of structural parameters and damage using only incomplete acceleration measurements. Copyright © 2007 John Wiley & Sons, Ltd.
Assessment of the access selection gain in multi‐radio access networks
Authors: Sachs Joachim , Magnusson Per
Published: November 2007

In this paper, we investigate the capacity gain of access selection in a multi‐radio access network with heterogeneous radio access technologies (RATs). We classify the kinds of gain that can be achieved by access selection: statistical multiplexing in the multi‐access system leads to a trunking gain, spatial transmission diversity results from the geographic capacity distribution of the cell layout, stochastic transmission diversity exploits the multi‐path fading characteristics. We show how these different properties are affected by the cell layout of the different RATs, the characteristics of each RAT and the traffic load distribution in the network. In a simulation environment the system capacity for the combination of two wide‐area access technologies, as well as, for the combination of a wide‐area and a local‐area access technology is investigated. For this, we compare two different access selection algorithms. One uses the radio link quality as an input parameter, while the other also considers the cell load. We derive quantitative figures for the capacity gain in a large number of scenarios and show that load‐based access selection can significantly increase the capacity. We show that the gain of an overlay of local‐area access cells provides little capacity gain for uniform geographic load distribution, whereas significant gain can be achieved when most users are located at hotspots. Copyright © 2007 John Wiley & Sons, Ltd.
Modelling of virtual‐circuit switching nodes with multicast connections
Authors: Głąbowski Mariusz , Stasiak Maciej , Zwierzykowski Piotr
Published: November 2007

This paper presents an approximate calculation methodology of the occupancy distribution and the blocking probability in a virtual circuit switching node with multi‐rate unicast and multicast traffic streams. Particular traffic streams are generated by an infinite as well as by a finite population of traffic sources. The model enables calculations of any structure of the groups forming the outgoing directions of the node. Additionally, bandwidth reservation algorithms are also proposed in order to improve traffic characteristics of different traffic classes. The results of the analytical calculations have been compared with the simulation results of a switching node carrying multicast and unicast traffic streams. Copyright © 2007 John Wiley & Sons, Ltd.
Mutational inactivation of TGFBR2 in microsatellite unstable colon cancer arises from the cooperation of genomic instability and the clonal outgrowth of transforming growth factor β resistant cells
Authors: Biswas Swati , Trobridge Patricia , Romero‐Gallo Judith , Billheimer Dean , Myeroff Lois L. , Willson James K. V. , Markowitz Sanford D. , Grady William M.
Published: November 2007

The mutational inactivation of transforming growth factor β receptor type II (TGFBR2) occurs in ∼30% of colon cancers and promotes the formation of colon cancer by inhibiting the tumor suppressor activity of the TGFB signaling pathway. TGFBR2 mutations occur in >90% of microsatellite unstable (MSI) colon cancers and affect a polyadenine tract in exon 3 of TGFBR2, called BAT‐RII, which is vulnerable to mutation in the setting of DNA mismatch repair (MMR) system deficiency. In light of the vulnerable nature of the BAT‐RII tract in the setting of MMR inactivation and the favorable effects of TGFBR2 inactivation in colon cancer, analysis of TGFBR2 inactivation provides an opportunity to assess the roles of genomic instability vs. clonal selection in cells acquiring TGFBR2 BAT‐RII tract mutations in MSI colon cancer formation. The contribution of genomic instability and/or clonal evolution to the mutational inactivation of TGBFR2 in MSI colon cancers has not been studied in a systematic way that would allow a determination of the relative contribution of these two mechanisms in the formation of MSI colon cancer. It has not been demonstrated whether the BAT‐RII tract mutations are strictly a consequence of the BAT‐RII region being hypermutable in the setting of MMR deficiency or if the mutations are rather a consequence of clonal selection pressure against the TGFB receptor. Through the use of defined cell line systems, we show that both genomic instability and clonal selection of TGFB resistant cells contribute to the high frequency of TGFBR2 mutations in MSI colon cancer. © 2007 Wiley‐Liss, Inc.