bluuebunny/crossref_metadata_2025 huggingface dataset:
Determining Decision Values of Context Awareness in Ubiquitous Computing Environments
Authors: Mowafi Yaser A , Forgionne Guisseppi
Published: July 2011

Research on context‐aware computing has been focusing on the technology aspect of context acquisition and interpretation of users' surrounding environment or physical context. There is no operational mechanism for integrating context awareness that is driven by user context such as users' ongoing activities and tasks. Although the necessity of integration of sensed context data with users' intent of conduct has been recognized by many researchers, it has never been empirically investigated. Using Analytic Hierarchy Process, we propose an integrated and comprehensive approach that takes into consideration both user and physical context in defining overall context awareness value. The approach is tested using secondary data of user activities in various situations and surrounding environment scenarios. The results suggest several preliminary guidelines for determining representative measures of user and physical context approaches in the design and evaluation of context‐aware systems. Copyright © 2011 John Wiley & Sons, Ltd.
Response of mouse brain perfusion to hypo‐ and hyperventilation measured by arterial spin labeling
Authors: Oosterlinck W. Wouter , Dresselaers T. , Geldhof V. , Van Santvoort A. , Robberecht W. , Herijgers P. , Himmelreich U.
Published: July 2011

We aimed to setup a noninvasive and well‐controlled methodology for evaluation of the cerebrovascular response in mice (C57BL/6J; 12 weeks). Therefore we applied a normo‐, hypo‐, and hyperventilation paradigm combined with arterial spin labeling and monitoring of the expired CO2 (expCO2) (n = 7) or arterial pCO2 (apCO2) (n = 12). Reducing the tidal volume by 25% and the respiratory rate by 20% resulted in hypercapnia (apCO2 from 33 ± 6 mmHg to 64 ± 16 mmHg). Increasing the respiratory rate by 25% and the tidal volume by 20% decreased apCO2 to 22 ± 5 mmHg. Cerebral blood flow (CBF) was 82 ± 21, 163 ± 41 and 64 ± 18 mL/100 g/min during normo, hypo‐, and hyperventilation, respectively (midbrain). The correlation of apCO2 and CBF levels resulted in a cerebrovascular response of 2.7 ± 0.3, 2.1 ± 0.3, 2.1 ± 0.3, and 3.7 ± 0.5 mL/100 g/min/mmHg for midbrain, cortex, hippocampus and thalamus, respectively. As expCO2 levels were correlated with apCO2 (r2 = 0.86; n = 4) and CBF (r2 = 0.67) a cerebrovascular response based on simultaneously recorded CBF and expCO2 levels could be derived (3.3 ± 0.5, 2.5 ± 0.4, 3.0 ± 0.4, and 4.5 ± 0.6 mL/100 g/min/mmHg; order as above). A cross‐over experiment resulted in similar responses. In conclusion, this protocol allows evaluating basal CBF and cerebrovascular response in mice under well‐controlled conditions by simply changing ventilator settings and correlating CBF with apCO2 and/or simultaneously obtained expCO2. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
Role of the lead structure in MRI‐induced heating: In vitro measurements on 30 commercial pacemaker/defibrillator leads
Authors: Mattei Eugenio , Calcagnini Giovanni , Censi Federica , Triventi Michele , Bartolini Pietro
Published: July 2011

MRI‐induced heating on endocardial leads is a serious concern for the safety of patients with implantable pacemakers or cardioverter‐defibrillator. The lead heating depends on many factors and its amount is largely variable. In this study, we investigated the role of those structural properties of the lead that are reported on the accompanying documents of the device: (1) fixation modality (active vs. passive); (2) number of electrodes (unipolar vs. bipolar); (3) length; (4) tip surface; and (5) tip and ring resistance. In vitro temperature and specific absorption rate measurements on 30 leads (27 pacemakers, three implantable cardioverter‐defibrillator leads) exposed to the radiofrequency field typical of a 1.5 T MRI scanner are presented. The data show that each lead has its own attitude to radiofrequency‐induced heating and that the information that is available in the accompanying documents of the pacemaker is not sufficient to explain such attitude. Even if combined with that of the implant geometry, this information is still not sufficient to estimate the amount of heating due to the exposure to the radiofrequency field during MRI examination. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
Iterative optimization method for design of quantitative magnetization transfer imaging experiments
Authors: Levesque Ives R. , Sled John G. , Pike G. Bruce
Published: July 2011

Quantitative magnetization transfer imaging (QMTI) using spoiled gradient echo sequences with pulsed off‐resonance saturation can be a time‐consuming technique. A method is presented for selection of an optimum experimental design for quantitative magnetization transfer imaging based on the iterative reduction of a discrete sampling of theZ‐spectrum. The applicability of the technique is demonstrated for human brain white matter imaging at 1.5 T and 3 T, and optimal designs are produced to target specific model parameters. The optimal number of measurements and the signal‐to‐noise ratio required for stable parameter estimation are also investigated. In vivo imaging results demonstrate that this optimal design approach substantially improves parameter map quality. The iterative method presented here provides an advantage over free form optimal design methods, in that pragmatic design constraints are readily incorporated. In particular, the presented method avoids clustering and repeated measures in the final experimental design, an attractive feature for the purpose of magnetization transfer model validation. The iterative optimal design technique is general and can be applied to any method of quantitative magnetization transfer imaging. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
In vivo magnetic resonance imaging of sodium and diffusion in rat glioma at 21.1 T
Authors: Schepkin Victor D. , Bejarano Fabian Calixto , Morgan Thomas , Gower‐Winter Shannon , Ozambela Manuel , Levenson Cathy W.
Published: July 2011

Sodium and diffusion magnetic resonance imaging (MRI) in intracranial rat 9L gliomas were evaluated over 6–8 days using the advanced sensitivity of sodium MRI at 21.1 T. Glioma doubling time was 2.4–2.6 days. Glioma sodium signal was detected using the ultra‐short echo time of 0.15 ms. The high resolution 3D sodium MRI with pixels of 0.125 μL allowed for minimizing a partial volume effect often relevant to the MRI of low intensity signals. Tumor sodium and diffusion MRI were evaluated for two separate subclones of 9L cells with different resistance to 1,3‐bis(2‐chloroethyl)‐1‐nitrosurea detected by pre‐surgery assays. In vivo, after implantation, resistant 9L cells created tumors with significantly reduced sodium concentrations (57 ± 3 mM) compared with nonresistant 9L cells (78 ± 3 mM). The corresponding differences in diffusion were less, but also statistically significant. During tumor progression, an increase of glioma sodium concentration was observed in both cell types with a rate of 2.4–5.8 %/day relative to normal brain. Tumor diffusion was not significantly changed at this time, indicative of no alterations in glioma cellularity. Thus, changes in sodium during tumor progression reflect increasing intracellular sodium concentration and mounting metabolic stress. These experiments also demonstrate an enhanced sensitivity of sodium MRI to reflect tumor cell resistance. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
Measurement of transverse relaxation times of J‐coupled metabolites in the human visual cortex at 4 T
Authors: Deelchand Dinesh Kumar , Henry Pierre‐Gilles , Uǧurbil Kâmil , Marjańska Małgorzata
Published: July 2011

Accurate quantification of 1H NMR spectra often requires knowledge of the relaxation times to correct for signal losses due to relaxation and saturation. In human brain, T2 values for singlets such as N‐acetylaspartate, creatine, and choline have been reported, but few T2 values are available for J‐coupled spin systems. The purpose of this study was to measure the T2 relaxation times of J‐coupled metabolites in the human occipital lobe using the LASER sequence. Spectra were acquired at multiple echo times and were analyzed with an LCModel using basis sets simulated at each echo time. Separate basis spectra were used for resonances of protons belonging to the same molecule but having very different T2 values (e.g., two separate basis spectra were used for the singlet and multiplet signal in N‐acetylaspartate). The T2 values for the N‐acetylaspartate multiplet (149 ± 12 ms), glutamate (125 ± 10 ms), myo‐inositol (139 ± 20 ms), and taurine (196 ± 28 ms) were successfully measured in the human visual cortex at 4 T. These measured T2 relaxation times have enabled the accurate and absolute quantification of cerebral metabolites at longer echo times. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
Delirium in Older Adults
Authors: Popeo Dennis M.
Published: July 2011

Delirium is a common neuropsychiatric syndrome in the elderly that can occur in several different settings caused by several different processes. It is common and causes increased morbidity and mortality to those affected. This clinical review discusses the prediction, prevention, diagnosis, and treatment of delirium in the elderly population. Several strategies to predict delirium are noted with the discussion of pharmacological and nonpharmacological trials of prevention and treatment. Diagnosis of delirium, specifically with the use of objective instruments, is discussed, as is the evidence for pharmacological and nonpharmacological treatment strategies. Discussion of the neurobiology and genetic markers for delirium may elucidate further areas for future research. Mt Sinai J Med 78:571–582, 2011. © 2011 Mount Sinai School of Medicine
Urinary Incontinence in Older Adults
Authors: Vaughan Camille P. , Goode Patricia S. , Burgio Kathryn L. , Markland Alayne D.
Published: July 2011

Urinary incontinence is a common problem among older women and men, has a significant negative impact on quality of life, and may be costly to treat. Older women experience higher rates of urinary incontinence than older men. The causes and types of urinary incontinence also differ among older women and men. Often, older adults are reluctant to seek treatment, and healthcare providers should inquire about symptoms. Detection of urinary incontinence and determination of severity and related symptoms is important for evaluation and treatment. Urinary incontinence can be evaluated and initially treated by primary‐care providers. Evaluation for urinary incontinence involves a focused history, physical examination, a urinalysis, and measurement of postvoid residual volume, if indicated. Office‐based treatments include behavioral approaches and medications. Older adults may also consider surgical options and devices to improve urinary incontinence. Older adults with cognitive impairment and incontinence require diagnostic and treatment modifications, but may respond well to treatment. Mt Sinai J Med 78:558–570, 2011. © 2011 Mount Sinai School of Medicine
Prescribing for Older Adults
Authors: Boparai Manpreet K. , Korc‐Grodzicki Beatriz
Published: July 2011

Pharmacotherapy of the elderly is very complex due to age‐related physiologic changes, multiple comorbidities, multiple medications (prescription, over‐the counter, and herbal), and multiple providers (prescribers and pharmacies). Age‐related physiologic changes and disease‐related changes in organ function affect drug handling (pharmacokinetics) and response (pharmacodynamics). In addition, patients' cognitive impairment, functional difficulties, as well as caregiver issues play a large role in errors and compliance. Many older adults have several chronic conditions, and they stand to benefit the most from best practice guidelines. However, they are also at risk of toxicity given our increasingly complex pharmacopoeia and potential adverse effects that can cause morbidity and mortality. It is imperative that physicians learn how to minimize side effects and interactions. Potentially inappropriate medications (medications that pose more risk than benefit to the patient) are among the most important causes of adverse drug reactions, independent of the number of medications and other confounding factors. Many of these adverse drug reactions could be predicted from the known pharmacology of the drug and therefore could be potentially avoidable. To prescribe appropriately, we need to consider not only the pharmacological properties of the drugs, but also clinical, epidemiological, social, cultural, and economic factors. Elders' adherence to prescribed medications is also complex and depends on medical, personal, and economic factors; cognitive status; and relationship with the physician. Detection of nonadherence is a necessary prerequisite for adequate treatment, and patient education is a cornerstone in achieving medication adherence. Finally, appropriate prescribing should include a consideration of life expectancy and goals of care. Mt Sinai J Med 78:613–626, 2011. © 2011 Mount Sinai School of Medicine
Alzheimer's Disease: Diagnosis and Treatment Across the Spectrum of Disease Severity
Authors: Neugroschl Judith , Wang Sophia
Published: July 2011

Alzheimer's disease exists along a spectrum, from early memory changes to functional dependence and death. Using a case illustration, we review the evaluation and diagnosis of mild cognitive impairment and the diagnosis and management of Alzheimer's disease at each stage, including the management of both cognitive and behavioral/psychiatric aspects of the disease and end‐stage and end‐of‐life care. Mt Sinai J Med 78:596–612, 2011. © 2011 Mount Sinai School of Medicine
Falls in Older Adults
Authors: Bradley Sara M.
Published: July 2011

Falls are prevalent among older adults and can lead to injury, hospitalization, and increased healthcare costs. Environmental hazards, medications, vision problems, and impairments in strength, gait, or balance can increase fall risk. A multifactorial fall‐risk assessment including a fall history, physical exam, gait and balance evaluation, and environmental assessment is recommended for all older adults who present with a fall or problem with gait or balance. Multiple‐component exercise programs, tai chi, vitamin D supplementation, withdrawal of psychotropic medications, and early cataract surgery have all been shown to reduce fall rates. Multifactorial interventions that include medication review, vision correction, management of orthostasis, environmental modification, and balance, strength, and gait training can also be beneficial in preventing falls. Mt Sinai J Med 78:590–595, 2011. © 2011 Mount Sinai School of Medicine
Differential aging of median and ulnar sensory nerve parameters
Authors: Werner Robert A. , Franzblau Alfred , D'Arcy Hannah J.S. , Evanoff Bradley A. , Tong Henry C.
Published: July 2011

Introduction: Nerve conduction velocity slows and amplitude declines with aging. Methods: Median and ulnar sensory nerves were tested at the annual meetings of the American Dental Association. Seven hundred four subjects had at least two observations. The rate of change in the nerve parameters was estimated while controlling for gender, age, change in hand temperature, baseline body mass index (BMI), and change in BMI. Results: Amplitudes of the median sensory nerve action potentials decreased by 0.58 μV per year, whereas conduction velocity decreased at a rate of 0.41 m/s per year. Corresponding values for the ulnar nerve were 0.89 μV and 0.29 m/s per year. The rates of change in amplitudes did not differ, but the median nerve demonstrated a more rapid loss of conduction velocity. Conclusions: The rate of change for the median conduction velocity was higher than previously reported. The rate of change of median conduction velocity was significantly greater than for the ulnar nerve. Muscle Nerve 45: 60–64, 2012
Prolonged hindlimb unloading leads to changes in electrophysiological properties of L5 dorsal root ganglion neurons in rats after 14 days
Authors: Ren Jun‐Chan , Fan Xiao‐Li , Song Xin‐Ai , Zhao Xue‐Hong , Chen Ming‐Xia , Shi Lei
Published: July 2011

Introduction: The purpose of this study was to evaluate the electrophysiological changes observed in dorsal root ganglion (DRG) neurons in a simulated weightlessness rat model and to assess the mechanisms involved in these changes. Methods: The simulated weightlessness model was created by hindlimb unloading (HU). Whole‐cell patch‐clamp recordings, conduction velocity measurement, and ultrastructural observation were performed. Results: In the HU rats, the action potentials had a longer duration and slower falling rate, but there was no significant effect on amplitude or rate of rise. HU also induced lowering of rheobase and of the threshold potential, making the cells more excitable. The conduction velocities in the proximal branches of ganglion cells were also decreased, and some degenerative changes in the myelin sheath were noted. Conclusions: This study provides evidence of plasticity of DRG neurons induced by HU. The changes observed might contribute to impaired motor performance in rats submitted to HU. Muscle Nerve 45: 65–69, 2012
Herpetofaunal Remains from Khonkho Wankane, an Urban and Ceremonial Centre in the Southern Lake Titicaca Altiplano: Unique Behavioural Correlates to Osseous Taphonomy
Authors: Pokines James T.
Published: July 2011

This research reports the herpetological (reptile and amphibian) remains from Khonkho Wankane, an urban and ceremonial centre in the southern Lake Titicaca region of the Bolivian Altiplano, which fluoresced during the Late Formative period. The total n = 1710, including a minimum of six taxa and representing a significant portion of the relatively depauperate modern herpetofauna recorded for the Lake Titicaca area. A lizard of the genus Liolaemus (Tropiduridae) was identified. Amphibians are represented by Andean toad Rhinella spinulosa (Bufonidae) and by at least four taxa of frogs: [cf. Gastrotheca marsupiata (Hylidae) and Pleurodema marmorata or P. cinerea and Telmatobius spp. (Leptodactylidae)]. The latter genus does not include members of the giant variants (T. culeus) that dwell in Lake Titicaca.

The question of how these remains were incorporated into the site deposits is examined taphonomically. No indicators of human or small carnivore predation were detected. Significant spatial clustering of amphibian remains was detected, with two clusters contributing n = 1562 or 92.4% of the amphibian total (n = 1690). These concentrations also are characterised by a depressed ratio of cranial versus postcranial elements, which cannot be explained by recovery methods. These concentrations of herpetofaunal remains likely represent in‐burrow deaths of species sheltering for thermoregulatory benefits away from this harsh Altiplano environment, with the lowered recovery of cranial elements hypothesised to have resulted from a lack of ossification. The bulk of herpetofaunal remains recovered therefore likely were recent intrusions into the site deposits and do not represent the residue of human exploitation during the occupation of Khonkho Wankane. Copyright © 2011 John Wiley & Sons, Ltd.
Structure and properties of phase‐change materials based on high‐density polyethylene, hard Fischer–Tropsch paraffin wax, and wood flour
Authors: Mngomezulu M.E. , Luyt A.S. , Krupa I.
Published: July 2011

Phase‐change materials based on high‐density polyethylene (HDPE), a hard Fischer–Tropsch paraffin wax (H1 wax), and alkali‐treated wood flour (WF) were investigated. The blends and composites were prepared by melt‐mixing. They were characterized in terms of their morphology as well as thermal, mechanical, thermomechanical, and water absorption properties. Although the scanning electron microscopy micrographs showed some evidence of intimate contact between WF and the HDPE matrix, there were poor filler dispersion and interfacial adhesion. The percentage miscibility of H1 wax in HDPE seems to have decreased with increasing wax content in the blends. A fairly strong affinity between the WF and H1 wax was noticed. There was plasticization of the HDPE matrix by the wax as well as inhomogeneity and uneven wax dispersion within the polymer matrix. The presence of H1 wax and WF influenced the crystallization behavior of the HDPE matrix. The incorporation of wax reduced the thermal stability of the blends and composites, but stabilized the WF. The H1 wax and WF differently influenced the viscoelastic properties of the HDPE matrix. In contrast to the blends where the tensile properties improved in the presence of wax, the composites showed poorer properties. An increase in wax content resulted in a decrease in water uptake by the composites. POLYM. COMPOS., © 2011 Society of Plastics Engineers.
New thermo‐oxidative protective coating for carbon/carbon composites in mid‐temperature range using a combination of nano‐filler and macro‐filler with polybenzoxazine as a carbon‐forming matrix
Authors: Jin Lin , Ishida Hatsuo
Published: July 2011

A novel main‐chain type, oligomeric benzoxazine has been synthesized as a highly thermo‐oxidative matrix material. The structure of the monomer is confirmed by 1H nuclear magnetic resonance spectroscopy and size exclusion chromatography. Octasilane polyhedral oligomeric silsesquioxane (OctaSilane POSS) and glass sphere are incorporated to form an effective oxidation‐protective coating for the carbon/carbon composites. The composition has been optimized by varying benzoxazine and OctaSilane POSS ratio with the aid of thermogravimetric analyses. The even distribution of the three components has been confirmed by laser Raman image, and the effectiveness of the coating has been investigated using isothermal weight loss measurement at 700°C in air for 1300 h. POLYM. COMPOS., © 2011 Society of Plastics Engineers.
Mechanical, thermal and dynamic‐mechanical behavior of banana fiber reinforced polypropylene nanocomposites
Authors: Biswal Manoranjan , Mohanty Smita , Nayak Sanjay K.
Published: July 2011

Natural fiber‐reinforced nanocomposites based on polypropylene/nanoclay/banana fibers were fabricated by melt mixing in a twin‐screw extruder followed by compression molding in this current study. Maleic anhydride polypropylene copolymer (MA‐g‐PP) was used as a compatibilizer to increase the compatibility between the PP matrix, clay, and banana fiber to enhance exfoliation of organoclay and dispersion of fibers into the polymer matrix. Variation in mechanical, thermal, and physico‐mechanical properties with the addition of banana fiber into the PP nanocomposites was investigated. It was observed that 3 wt% of nanoclay and 5 wt% of MA‐g‐PP within PP matrix resulted in an increase in tensile and flexural strength by 41.3% and 45.6% as compared with virgin PP. Further, incorporation of 30 wt% banana fiber in PP nanocomposites system increases the tensile and flexural strength to the tune of 27.1% and 15.8%, respectively. The morphology of fiber reinforced PP nanocomposites has been examined by using scanning electron microscopy and transmission electron microscopy. Significant enhancement in the thermal stability of nanocomposites was also observed due to the presence of nanoclay under thermogravimetric analysis. Dynamic mechanical analysis tests revealed an increase in storage modulus (E′) and damping factor (tan δ), conforming the strong interaction between nanoclay/banana fiberand MA‐g‐PP in the fiber‐reinforced nanocomposites systems. POLYM. COMPOS., © 2011 Society of Plastics Engineers.
Effect of the addition of modified mica on mechanical and durability properties of FRP composite materials for civil engineering
Authors: Robert Mathieu , Cousin Patrice , Fam Amir , Benmokrane Brahim
Published: July 2011

The durability of fiber reinforced polymer (FRP) composite materials in humid and harsh environments is an important consideration for acceptance of these materials in civil engineering applications. Reducing the moisture ingress may improve the durability of FRPs. The addition of modified inorganic powder, such as clay nanoparticles, may improve several important properties of polymers, such as barrier properties, fire retardancy, dimensional stability, and mechanical strength. The present work aims to evaluate the effect of the addition of modified mica on FRP properties used in civil engineering applications. To conduct this preliminary study, the following steps were taken: (1) prepare and characterize composites made from lab‐made modified mica, (2) determine the maximum water uptake, water absorption rate and coefficient of diffusion, (3) characterize the mechanical properties, and finally, (4) evaluate the UV resistance. The experimental results show that the use of nanoparticles leads to a decrease of the coefficient of diffusion of water and a significant increase of stiffness and UV resistance. POLYM. COMPOS., © 2011 Society of Plastics Engineers.
Kinetic modeling of nanoclay‐reinforced unsaturated polyester resin
Authors: Poorabdollah Mehdi , Beheshty Mohammad Hosain , Vafayan Mehdy
Published: July 2011

Curing behavior of an unsaturated polyester (UP) resin containing 1 wt% organically modified clay (OMC) catalyzed with methyl ethyl ketone peroxide (MEKP) initiator and promoted by cobalt naphthenate accelerator was investigated by dynamic differential scanning calorimetry (DSC) at five different heating rates of 5, 10, 15, 20, and 25°C/min. X‐ray diffraction and transmission electron microscopy were used to evaluate the morphology of UP/OMC composites. Results showed a mixture of intercalated and exfoliated morphology. The dynamic DSC curing curves showed a bimodal exothermic peak; therefore, two independent reactions, namely, redox and thermal copolymerizations were assumed. Kinetic parameters were calculated by using autocatalytic model and using Down hill simplex method and Runge–Kutta algorithm for each reaction. The addition of nanoclay resulted in decrease of the activation energy of the redox reaction compared to that of the neat UP resin. Also, the pre‐exponential factor of the first reaction for UP/OMC was less than that of the neat UP. Two factors including decreasing the activation energy and decreasing the number ofcollisions of reactionary components finally resulted in increasing the reaction rate of the first reaction out of the whole reaction in the system containing nanoclay compared to the neat UP resin. It is interesting that nanoclay has no effect on the thermal decomposition reaction. POLYM. COMPOS., © 2011 Society of Plastics Engineers.
Electrospinning of polylactide and its composites with carbon nanotubes
Authors: Yang Tao , Wu Defeng , Lu Liangliang , Zhou Weidong , Zhang Ming
Published: July 2011

Electrospinning of the biodegradable polylactide (PLA) and its composites containing carbon nanotubes (CNTs) was studied in terms of solution concentrations and solvents effects as well as CNT loadings. The results reveal that the PLA fibers obtained from the solutions using the mixed solvents of chloroform/assistant solvent (v/v 3/1) show better morphologies than those from the solutions using chloroform as the single solvent. This is due to the synergistic effect by the improved conductivity and altered viscosity with addition of assistant solvent. Moreover, the surface structure of fibers depends on the volatility of assistant solvents strongly. Using volatile acrylonitrile or acetone as the assistant solvents, the columned fibers with porous surface structure are obtained; while the flat fibers with fluted surface are formed using nonvolatile dimethyl sulfoxide as the assistant solvents. As for electrospinning of the PLA/CNT composites, the morphology of obtained fibers is closely related to the dispersion of CNTs in the fibers. At low loading levels, the CNTs can be well embedded in the PLA matrix and oriented along the fiber axis, forming nanowire structure. At high loading levels, the CNTs are mainly dispersed as entangled bundles along the fiber axis, and as a result, the obtained fibers show tortuous or misshaped morphologies. Compared with that of the neat PLA fibers, the overall morphologies of the composite fibers are more or less degraded because the presence of some small CNT aggregates in the solutions easily leads to the formation of beaded fiber structure during electrospinning. The conductivity of the obtained composite fiber mats was further studied in terms of CNT loadings. POLYM. COMPOS., © 2011 Society of Plastics Engineers.
Numerical prediction of flake orientation and surface color in injection molding of flake‐pigmented thermoplastics
Authors: Park Jang Min , Jeong Seok Jae , Park Seong Jin
Published: July 2011

The present study attempts to develop physical modeling and numerical simulation system for prediction of the surface color in injection molding of flake‐pigmented thermoplastic composites. Folgar–Tucker model along with the orientation tensor is employed to predict the orientation state of pigment flakes. A phenomenological relationship between the orientation state and the surface color is proposed to estimate the surface color and color defects from the orientation prediction result. Basic studies are carried out using simple geometries with a hole or rib structure. Also a qualitative comparison between the numerical prediction and the experimental result is carried out for a complex geometry having ribs and holes. The color defects such as flow marks and weld lines could be reasonably predicted using the developed modeling and simulation system. POLYM. COMPOS., © 2011 Society of Plastics Engineers.
Prenatal features of Noonan syndrome: prevalence and prognostic value
Authors: Baldassarre G. , Mussa A. , Dotta A. , Banaudi E. , Forzano S. , Marinosci A. , Rossi C. , Tartaglia M. , Silengo M. , Ferrero G. B.
Published: July 2011

Objective

Noonan syndrome (NS) is a common autosomal dominant developmental disorder, mainly characterized by congenital heart defects, short stature, and a variable degree of developmental delay. We have reviewed the prenatal findings in NS and we have correlated them with genotype and postnatal phenotype.

Methods

The cohort consisted of 47 patients with molecular diagnosis of NS. Prenatal and postnatal phenotypes were assessed by analysis of medical records, and clinical follow‐up. Postnatal clinical phenotype, congenital heart disease, neuropsychomotor development, and growth pattern were arbitrarily scored in terms of severity.

Results

Mean age at diagnosis of NS was 7 years (ranging from birth to 38 years). Abnormal maternal serum triple screen was present in 36% of cases, nuchal translucency > 2.5 mm in 41%, polyhydramnios in 38% and fetal anomalies at prenatal ultrasonography in 21%. No statistical association was observed between prenatal findings and NS genotype or scores of postnatal clinical phenotype, congenital heart disease, neuropsychomotor development, or short stature. Presence of morphologic fetal anomalies at ultrasonography was associated with developmental delay/intellectual disabilities (p < 0.001) and juvenile myelomonocytic leukaemia (p = 0.006).

Conclusions

Abnormal prenatal findings are frequent in NS pregnancies, though they are not specific and most are not useful for the prediction of the postnatal phenotype. Copyright © 2011 John Wiley & Sons, Ltd.
First‐trimester prediction of preeclampsia using metabolomic biomarkers: a discovery phase study
Authors: Odibo Anthony O. , Goetzinger Katherine R. , Odibo Linda , Cahill Alison G. , Macones George A. , Nelson D. Michael , Dietzen Dennis J.
Published: July 2011

Objective

We tested the hypothesis that first‐trimester metabolic biomarkers offered a unique profile in women with preeclampsia (PE) in the second half of pregnancy, compared with controls.

Method

We conducted a nested case‐control study within a prospective cohort of pregnant women followed from the first‐trimester to delivery. Cases were those who developed PE at any gestational age, and these were compared with a control group without adverse pregnancy outcome, matched for gestational age within 3 days. We analyzed maternal blood obtained at 11–14 weeks' gestation for 40 acylcarnitine species (C2–C18 saturated, unsaturated, and hydroxylated) and 32 amino acids by liquid chromatography tandem mass spectrometry. Logistic regression modeling estimated the association of each metabolite with development of PE.

Results

We compared 41 cases with PE with 41 controls and found four metabolites (hydroxyhexanoylcarnitine, alanine, phenylalanine, and glutamate) that were significantly higher in the cases with PE. The area under the curve (AUC) using these metabolites individually to predict PE varied from 0.77 to 0.80, and when combined, the AUC improved to 0.82 [95% confidence interval (95% CI): 0.80–0.85] for all cases of PE and 0.85 (95% CI: 0.76–0.91) for early onset PE.

Conclusion

Our findings suggest a potential role for first‐trimester metabolomics in screening for PE. Copyright © 2011 John Wiley & Sons, Ltd.
Second trimester biparietal diameter size and the risk of adverse pregnancy outcomes
Authors: Marsoosi Vajiheh , Pirjani Reihaneh , Jamal Ashraf , Eslamian Laleh , Rahimi‐Foroushani Abbas
Published: July 2011

Objective

To identify the relationship between biparietal diameter (BPD) in the second trimester and adverse pregnancy outcomes in low‐risk pregnancies.

Method

This prospective cohort study was performed on 2219 singleton pregnant women from August 2008 to March 2010. The gestational age‐specific percentiles of BPD at 17 to 24 weeks of gestation were established to categorize participants into three groups: a BPD < 10th percentile as small BPD, between 10th and 90th percentile as normal BPD and > 90th percentile as large BPD. Using logistic regression analysis, the association between BPD < 10th and > 90th percentile with pregnancy outcomes was evaluated after controlling for confounding factors.

Results

There was a significantly increased risk of macrosomia [odds ratio (ORadj) = 2.1; 95% confidence intervals (CI), 1.23–3.78] and preterm labor (PTL) (ORadj = 1.9; 95% CI, 1.19–3.05) in fetuses with a BPD > 90th percentile compared with fetuses with a normal BPD, and there was a significant relationship between small for gestational age (SGA) at delivery and a BPD < 10th percentile at the second trimester (ORadj = 2.4; 95% CI, 1.77–3.52). No association was present between preeclampsia and second trimester BPD.

Conclusion

BPD in the first half of pregnancy is related to fetal size at term and risk of PTL. Copyright © 2011 John Wiley & Sons, Ltd.
Venous thromboembolism prophylaxis after total knee or hip replacement: treatment pattern and outcomes
Authors: Penning‐van Beest Fernie J. A. , Overbeek Jetty A. , Meijer Willemijn M. , Woodruff Kimberly , Jackson Joseph , van der Vis Harm , van der Linden Paul , Herings Ron M. C.
Published: July 2011

Purpose

To determine the thromboprophylactic treatment pattern and occurrence of venous thromboembolism (VTE), major bleeding, and wound infections in patients undergoing total knee replacement (TKR) or total hip replacement (THR).

Methods

From the PHARMO database, all patients ≥18 years hospitalized for TKR or THR between January 2003 and September 2008 were selected. Patients with pharmacy data up to 3 months after hospitalization were included in the study cohort. Duration and type of thromboprophylaxis were assessed. VTE, major bleeding, and wound infections were identified by hospitalizations. Regarding VTE, timing of event in relation to thromboprophylaxis was determined.

Results

The study population included 2930 patients with TKR, 5332 patients with THR without hip fracture, and 289 patients with THR and hip fracture. Mean duration of thromboprophylaxis was about 30 (± 20) days for all procedures, with low‐molecular‐weight heparin being the most frequently used drug. During 3 months of follow‐up, 1% to 2% of patients were hospitalized for an event. The most observed event was wound infection (58%), followed by major bleeding (29%), and VTE (13%). For wound infection and major bleeding, median time after surgery was about 19 days. Median time between surgery and VTE was 24 days for TKR and 60 days for THR. Eighteen of 23 VTE occurred during thromboprophylaxis.

Conclusions

Although patients are often treated for fewer days than recommended, thromboprophylaxis after TKR and THR in the Netherlands is adequate. Only 5 of 23 VTE hospitalizations occurred off‐treatment and might have been prevented. Furthermore, fewer than 1% of patients were hospitalized for bleeding. Copyright © 2011 John Wiley & Sons, Ltd.
A theoretical prediction on the ground‐state complexes bound by metal ions to thymine base isomers
Authors: Chen Jinpeng , Ai Hongqi , Zhao Yongping , Liu Jingjing
Published: July 2011

Stability orderings of 150 stable complexes formed by metal ions (Na+, K+, Ca2+, Mg2+, and Zn2+) and 13 stable thymine tautomers in both solvent and gas phases are obtained, and the optimal binding site for a metal ion in a specific thymine tautomer is identified. Results indicate that the complex with the canonical thymine tautomer (T1) is more stable than those with the rare ones, and the monodentate complex M–T1o4(o2) are their ground‐state form in the solvent phase. The ground‐state thymine complexes bound by Ca2+, Mg2+, or Zn2+ become bidentate M–T3o4lo2,n3, which is derived from a rare thymine tautomer T3o4l, whereas those bound by Na+ and K+ are still monodentate complexes M–T1o4(o2), however, in the gas phase. The differences in stability are discussed in detail from the binding strength of metal ions, relative energy of the corresponding thymine tautomers, and solution effect. Copyright © 2011 John Wiley & Sons, Ltd.
Kinetic elucidation of comonomer‐induced chemical and physical activation in heterogeneous ziegler‐natta propylene polymerization
Authors: Taniike Toshiaki , Tien Nguyen Binh , Takahashi Shougo , Quoc Vu Thang , Ikeya Mitsuhiro , Terano Minoru
Published: July 2011

We have kinetically elucidated the origins of activity enhancement because of the addition of comonomer in Ziegler‐Natta propylene polymerization, using stopped‐flow and continuously purged polymerization. Stopped‐flow polymerization (with the polymerization time of 0.1–0.2 s) enabled us to neglect contributions of physical phenomena to the activity, such as catalyst fragmentation and reagent diffusion through produced polymer. The propagation rate constant kp and active‐site concentration [C*] were compared between homopolymerization and copolymerization in the absence of physical effects. kp for propylene was increased by 30% because of the addition of a small amount of ethylene, whereas [C*] was constant. On the contrary, both kp (for propylene) and [C*] remained unchanged by the addition of 1‐hexene. Thus, only ethylene could chemically activate propylene polymerization. However, continuously purged polymerization for 30 s resulted in much more significant activation by the addition of comonomer, clearly indicating that the activation phenomenon mainly arises from the physical effects. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Efficient catalysts for ring‐opening polymerization of ε‐caprolactone and β‐butyrolactone: Synthesis and characterization of zinc complexes based on benzotriazole phenoxide ligands
Authors: Tai Yu‐En , Li Chen‐Yu , Lin Chia‐Her , Liu Yi‐Chang , Ko Bao‐Tsan , Sun Ya‐Sen
Published: July 2011

A series of efficient zinc catalysts supported by sterically bulky benzotriazole phenoxide (BTP) ligands are synthesized and structurally characterized. The reactions of diethyl zinc (ZnEt2) with CMe2PhBTP‐H, t‐BuBTP‐H, and TMClBTP‐H yield monoadduct [(μ‐BTP)ZnEt]2 (1–3), respectively. Bisadduct complex [(t‐BuBTP)2Zn] (4) results from treatment of ZnEt2 with t‐BuBTP‐H (2 equiv.) in toluene, but treatment of TMClBTP‐H with ZnEt2 in the same stoichiometric proportion in Et2O produces five‐coordinated monomeric complex [(TMClBTP)2Zn(Et2O)] (5). The molecular structures of compounds 1, 4, and 5 are characterized by X‐ray crystal structure determinations. All complexes 1–5 are efficient catalysts for the ring‐opening polymerization of ε‐caprolactone (ε‐CL) in the presence of 9‐anthracenemethanol. Experimental results indicate that complex 3 exhibits the greatest activity with well‐controlled character among these complexes. The polymerizations of ε‐CL and β‐butyrolactone catalyzed by 3 are demonstrated in a “living” character with narrow polydispersity indices (monomer‐to‐initiator ratio in the range of 25–200, PDIs ≤ 1.10). The “immortal” character of 3 provides a way to synthesize as much as 16‐fold polymer chains of poly(ε‐CL) (PCL) with narrow PDI in the presence of a catalyst in a small proportion. The controlled fashion of complex 3 also enabled preparation of the PCL‐b‐poly(3‐hydroxybutyrate) copolymer. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Synthesis, characterization, and properties of tunable thermosensitive amphiphilic dendrimer‐star copolymers with Y‐shaped arms
Authors: Yuan Weizhong , Zhang Jinchun , Wei Jingren , Yuan Hua , Ren Jie
Published: July 2011

Novel and well‐defined amphiphilic dendrimer‐star copolymer poly(ε‐caprolactone)‐block‐(poly(2‐(2‐methoxyethoxy)ethylmethacrylate‐co‐oligo(ethylene glycol) methacrylate))2 with Y‐shaped arms were synthesized by the combination of ring‐opening polymerization (ROP) and atom transfer radical polymerization (ATRP). The investigation of thermal properties and the analysis of crystalline morphology indicate that the high‐branched structure of dendrimer‐star copolymers with Y‐shaped arms and the presence of amorphous P(MEO2MA‐co‐OEGMA) segments together led to the complete destruction of crystallinity of the PCL segments in the dendrimer‐star copolymer. In addition, the hydrophilicity–hydrophobicity transition of the dendrimer‐star copolymer film can be achieved by altering the external temperatures. The amphiphilic copolymers can self‐assemble into spherical nanomicelles in water. Because the lower critical solution temperature of the copolymers can be adjusted by varying the ratio of MEO2MA and OEGMA, the tunable thermosensitive properties can be observed by transmittance, dynamic laser light scattering, and transmission electron microscopy (TEM). The release rate of model drug chlorambucil from the micelles can be effectively controlled by changing the external temperatures, which indicates that these unique high‐branched amphiphilic copolymers have the potential applications in biomedical field. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Effect of Somatosensory Stimulation of Two and Three Nerves on Upper Limb Function in Healthy Individuals
Authors: Sorinola Isaac Olubunmi , Bateman Robert William , Mamy Katherine
Published: July 2011

Background and Purpose

Improvement in motor function has been reported in healthy subjects following somatosensory stimulation (SS) of individual upper limb peripheral nerves. This effect could have beneficial applications in rehabilitation, but there is little knowledge of the effects of stimulating multiple upper limb nerves. This study evaluated the effects of SS of two and three nerves on hand function.

Methods

A single blind within‐group repeated measures design was utilized. Ten healthy subjects (27.1 ± 5.4 years [mean ± SD], three men) were recruited and, after a familiarization session, were given SS to the ipsilateral hand in a randomized order to two (ulnar and median) and three (ulnar, median and radial) nerves on two occasions separated by at least one week. The time required to complete the Jebsen–Taylor Hand Function Test (JTHFT) and handgrip strength of the ipsilateral hand were measured before and immediately after each SS session.

Results

Total JTHFT time decreased significantly by an average of 3.58 ± 2.75 s (9.9%; P = 0.003) and 4.10 ± 3.20 s (11.6%; P = 0.003) following SS to two and three nerves, respectively, but no difference between the two was found. Handgrip strength decreased significantly by 1.82 ± 1.91 kgf (P = 0.015) following SS to three nerves only.

Conclusions

This study suggests that SS of three nerves may facilitate motor training but may also induce a reduction in muscle performance. Further studies are needed to determine the clinical implications of these findings for neurological rehabilitation. Copyright © 2011 John Wiley & Sons, Ltd.
Cleavage of cellulose by a CBM33 protein
Authors: Forsberg Zarah , Vaaje‐Kolstad Gustav , Westereng Bjørge , Bunæs Anne C. , Stenstrøm Yngve , MacKenzie Alasdair , Sørlie Morten , Horn Svein J. , Eijsink Vincent G.H.
Published: July 2011

Bacterial proteins categorized as family 33 carbohydrate‐binding modules (CBM33) were recently shown to cleave crystalline chitin, using a mechanism that involves hydrolysis and oxidation. We show here that some members of the CBM33 family cleave crystalline cellulose as demonstrated by chromatographic and mass spectrometric analyses of soluble products released from Avicel or filter paper on incubation with CelS2, a CBM33‐containing protein from Streptomyces coelicolor A3(2). These enzymes act synergistically with cellulases and may thus become important tools for efficient conversion of lignocellulosic biomass. Fungal proteins classified as glycoside hydrolase family 61 that are known to act synergistically with cellulases are likely to use a similar mechanism.
Emerging treatment options for patients with castration‐resistant prostate cancer
Authors: George Daniel , Moul Judd W.
Published: July 2011

BACKGROUND

Most prostate cancer‐related deaths occur in patients with castration‐resistant prostate cancer (CRPC). Recent preclinical and clinical studies have identified intracellular signaling pathways and changes in the tumor and bone microenvironment as potential key drivers of CRPC. This increased understanding of mechanisms associated with CRPC has driven the development of numerous new agents, many of which are poised to alter the current CRPC treatment landscape.

METHODS

A review of literature was conducted to identify ongoing and planned phase III studies of novel agents to treat CRPC.

RESULTS

Multiple studies were identified, including novel androgen biosynthesis inhibitors (abiraterone, TAK‐700), androgen‐receptor inhibitors (MDV3100), angiogenesis inhibitors (aflibercept, tasquinimod), endothelin antagonists (zibotentan, atrasentan), a Src tyrosine kinase inhibitor (dasatinib), a novel radiotherapy (radium‐223), and new immunotherapies (ipilimumab and ProstVac). In addition, both sipuleucel‐T (an immunotherapy) and cabazitaxel (third‐generation taxane) and the RANK‐L inhibitor, denosumab, have recently been approved by the US Food and Drug Administration.

CONCLUSIONS

Various combinations of these agents could theoretically be used to treat future patients with CRPC by targeting multiple signaling pathways as well as aspects of the tumor and bone microenvironments. Additional research will be needed to understand how to best use these agents and individualize care to optimize CRPC patient outcomes. Prostate 72:338–349, 2012. © 2011 Wiley Periodicals, Inc.