bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of Anisotropic Polymer Particles with Soap‐Free Emulsion Polymerization in the Presence of a Reactive Silane Coupling Agent
Authors: Nagao Daisuke , Hashimoto Masahiko , Hayasaka Kentaro , Konno Mikio
Published: July 2008

A novel two step method has been developed for the preparation of anisotropic polymer particles using soap‐free emulsion polymerization in the presence of the reactive silane coupling agent 3‐methacryloxypropyltrimethoxysilane (MPTMS). In the first step, seed polymer particles were prepared in the presence of MPTMS in water. In the second step, another polymerization was conducted in the presence of the seed particles, which induced anisotropic protrusion of polymer from the seed particles. The two step method is applicable to the preparation of anisotropic polymer particles containing inorganic particles such as silica. Silica particles inside the anisotropic polymer particles were dissolved with hydrofluoric acid, which created hollow polymer particles with anisotropy.

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Brownian Dynamics Simulations of Rotational Diffusion Using the Cartesian Components of the Rotation Vector as Generalized Coordinates
Authors: Evensen Tom Richard , Naess Stine Nalum , Elgsaeter Arnljot
Published: July 2008

Here, we report on the first Brownian dynamics (BD) simulations of rotational diffusion using the Cartesian components of the rotation vector as the generalized coordinates. The model system employed in this study consists of freely rotating and non‐interacting rigid particles with arbitrary surface topography. The numerical BD algorithm contains no singularities and yields numerical results that are in full agreement with known theoretical results. Because of the absence of singularities, this new algorithm is several orders of magnitude more efficient than a simple BD algorithm employing the Euler angles as the generalized coordinates. The general theory for using generalized coordinates in studies of more complex systems involving both translation, rotation, and fluid dynamic interactions is well known. Consequently, the benefits reported here can readily be extended to such systems. Important examples are segmented polymer chains, with and without holonomic constraints, and liquid crystals.

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Hemidystonia secondary to thalamic hemorrhage treated with GPi stimulation
Authors: Hamasaki Tadashi , Yamada Kazumichi , Kuratsu Jun‐ichi
Published: July 2008

There have been few reports on the surgical treatment of secondary hemidystonias, most of which are due to basal ganglia stroke or trauma. We present 2 patients with hemidystonia secondary to thalamic hemorrhage whom we successfully treated with unilateral globus pallidus internus (GPi) stimulation. Case 1 is a 56‐year‐old man with abnormal posturing and intolerable muscle contraction pain in the left arm. Case 2 is a 73‐year‐old woman who developed severe abnormal posturing in the right arm and gait disturbance due to hyperextension of the right leg. The dystonic symptoms of both patients were refractory to medication. Three months after the inception of high frequency GPi stimulation, the motor scores on the Burke‐Fahn‐Marsden Dystonia Rating Scale were improved by 49.2% and 34.3% in Cases 1 and 2, respectively. We suggest GPi stimulation as a possible alternative to treat secondary hemidystonia. © 2008 Movement Disorder Society
Autonomic dysfunction in different subtypes of multiple system atrophy
Authors: Schmidt Claudia , Herting Birgit , Prieur Silke , Junghanns Susann , Schweitzer Katherine , Globas Christoph , Schöls Ludger , Reichmann Heinz , Berg Daniela , Ziemssen Tjalf
Published: July 2008

Multiple system atrophy (MSA) can clinically be divided into the cerebellar (MSA‐C) and the parkinsonian (MSA‐P) variant. However, till now, it is unknown whether autonomic dysfunction in these two entities differs regarding severity and profile. We compared the pattern of autonomic dysfunction in 12 patients with MSA‐C and 26 with MSA‐P in comparison with 27 age‐ and sex‐matched healthy controls using a standard battery of autonomic function tests and a structured anamnesis of the autonomic nervous system. MSA‐P patients complained significantly more often about the symptoms of autonomic dysfunctions than MSA‐C patients, especially regarding vasomotor, secretomotor, and gastrointestinal subsystems. However, regarding cardiovascular, sudomotor pupil, urogenital, and sleep subsystems, there were no significant quantitative or qualitative differences as analyzed by autonomic anamnesis and testing. Our results suggest that there are only minor differences in the pattern of autonomic dysfunction between the two clinical MSA phenotypes. © 2008 Movement Disorder Society
Ultrasonographic findings of shoulder disorders in patients with Parkinson's disease
Authors: Koh Seong‐Beom , Roh Jee‐Hoon , Kim Ji Hyun , Oh Kyungmi , Kim Byung‐Jo , Kim Gui‐Sang , Park Byung‐Kyu , Kim Se‐Ju , Yoon Joon‐Shik
Published: July 2008

The prevalence of a history of shoulder complaints is higher in patients with Parkinson's disease (PD) than in healthy individuals. The aims of this study were to evaluate shoulder disease in PD patients with ultrasonography (US) and to identify the relationship between the US findings of shoulder disease and the motor signs in patients with PD. Thirty‐three PD patients completed a shoulder disability questionnaire, a musculoskeletal examination, and US of the shoulder. Twenty‐two patients had abnormal US findings. Tendon tearing was the most common abnormal US finding (22/22), and the supraspinatus tendon was the most common site involved (15/22). Patients with tendon tearing had a significantly longer duration of disease than patients without tendon tearing (P = 0.027). Patients with adhesive capsulitis had a significantly higher rigidity score than patients without adhesive capsulitis (P = 0.035). Disease duration and rigidity were the contributing factors for the development of tendon tearing and adhesive capsulitis, respectively. © 2008 Movement Disorder Society
Ipsilateral sequential arm movements after unilateral subthalamic deep‐brain stimulation in patients with Parkinson's disease
Authors: Agostino Rocco , Dinapoli Loredana , Modugno Nicola , Iezzi Ennio , Gregori Bruno , Esposito Vincenzo , Romanelli Pantaleo , Berardelli Alfredo
Published: July 2008

Unilateral STN‐DBS significantly improves the performance of contralateral sequential arm movements. Whether unilateral STN‐DBS also improves ipsilateral sequential movement is unclear. In this study in unmedicated parkinsonian patients, we tested the effect of unilateral STN‐DBS on the performance of ipsilateral sequential movements and compared it with the performance of contralateral sequential movements. Three‐dimensional movements were recorded with the ELITE system and three kinematic variables were considered: total movement time (TMT), total inter‐onset latency (IOL), and spatial accuracy. Unilateral STN‐DBS significantly decreased TMT in the contralateral arm and only tended to do so also in the ipsilateral arm, whereas it significantly decreased IOL and worsened spatial accuracy only on the contralateral side. Before unilateral STN‐DBS a positive correlation was present between the clinical impairment and the TMTs in the contralateral and ipsilateral sides. After unilateral STN‐DBS the UPDRS scores improved in the contralateral and to a lesser extent also in the ipsilateral side. Correlation analysis between clinical and kinematic data showed no differences between the contralateral and ipsilateral sides. Our kinematic findings show that after STN‐DBS parkinsonian patients' performance of a sequential motor task improves significantly on the contralateral but only tended to do so on the ipsilateral side. Ipsilateral changes can be explained by the observation that the output structures of the basal ganglia send large ipsilateral and less dense contralateral projections to the thalamus. © 2008 Movement Disorder Society
Psychosis, short stature in benign hereditary chorea: A novel thyroid transcription factor‐1 mutation
Authors: Glik Amir , Vuillaume Isabelle , Devos David , Inzelberg Rivka
Published: July 2008

Benign hereditary chorea (BHC) is a rare autosomal dominant nonprogressive movement disorder. In some cases the phenotype includes, besides choreoathetosis, thyroid dysfunction and pulmonary infections in infancy, as expressed by the name “Brain‐Thyroid‐Lung syndrome”. Mutations in the thyroid transcription factor‐1 (TITF‐1) gene have been identified in some BHC families. We present the phenotypic features of a family with chorea, hypothyroidism, and lung dysfunction. All affected individuals suffered from a nonprogressive chorea with infancy onset. All showed short stature and some webbed neck. One patient suffered from psychosis at the age of 27 years another from lung carcinoma. In all affected individuals, a novel mutation consisting of heterozygous C to A substitution at position 650 of the coding sequence of the TITF‐1 gene, exon 3 was detected, leading to a premature stop at codon 217 (S217X). We describe the unique phenotypic features and intrafamilial variability expressing this novel mutation. © 2008 Movement Disorder Society
Arm swing is reduced in idiopathic cervical dystonia
Authors: Kägi Georg , Schwingenschuh Petra , Bhatia Kailash P.
Published: July 2008

Arm swing is typically reduced in people with Parkinsonism, and also in those with pyramidal dysfunction. We have previously observed that patients with focal arm dystonia can also have reduced arm swing. However, arm swing has not been formally studied in adult‐onset primary cervical dystonia (AOPCD). We assessed arm swing in 100 consecutive patients diagnosed with AOPCD and 50 healthy controls. Reduced arm swing was more common in patients with AOPCD compared with healthy controls (55% vs. 6%, P < 0.001) and was more often abnormal on the same side as the direction of head turning (P < 0.05). Women with AOPCD had more often reduced arm swing compared with men (P = 0.002). Reduced arm swing is common in AOPCD. It may indicate segmental spread of subtle motor dysfunction or it may be a feature of dystonia per se. © 2008 Movement Disorder Society
Frequency of social phobia and psychometric properties of the Liebowitz social anxiety scale in Parkinson's disease
Authors: Kummer Arthur , Cardoso Francisco , Teixeira Antonio L.
Published: July 2008

There are few studies about social anxiety disorder in Parkinson's disease (PD). The objective of this study was to assess its frequency and to explore the psychometric properties of the Liebowitz social anxiety scale (LSAS) in PD. Ninety patients with PD underwent neurologic and psychiatric examination. Psychiatric examination was composed by a structured clinical interview (MINI‐Plus) followed by the application of the LSAS, the Hamilton depression rating scale (Ham‐D), and the Hamilton anxiety rating scale (Ham‐A). Neurologic examination included the MMSE, the UPDRS, the Hoehn‐Yahr Scale, and the Schwab‐England scale of activities of daily living. Social phobia was diagnosed in 50% of PD patients. The disorder was not associated with any sociodemographic or neurological feature, but was associated to major depression (P= 0.023), generalized anxiety disorder (P= 0.023), and obsessive‐compulsive disorder (P= 0.013). The score of LSAS correlated positively with the scores of Ham‐D and Ham‐A (P< 0.001 for both). A ROC curve analysis of the LSAS suggested that a cutoff score in 41/42 provided the best balance between sensitivity and specificity. This disorder seems to be more common and not just restricted to performance as previously thought. © 2008 Movement Disorder Society
Dopaminergic deficit is not the rule in orthostatic tremor
Authors: Trocello Jean‐Marc , Zanotti‐Fregonara Paolo , Roze Emmanuel , Apartis Emmanuelle , Legrand André‐Pierre , Habert Marie‐Odile , Devaux Jean‐Yves , Vidailhet Marie
Published: July 2008

Involvement of the dopaminergic system in orthostatic tremor is controversial. The aim of this study was to detect possible dopaminergic denervation in primary orthostatic tremor (OT). Twelve consecutive patients with a firm diagnosis of primary orthostatic tremor were compared with age‐matched normal controls. All the patients had a neurological examination, surface polymyography, and quantification of striatal dopamine transporters with 123I‐FP‐CIT SPECT imaging. There was no significant difference in 123I‐FP‐CIT SPECT findings between controls and patients with OT. Longstanding primary orthostatic tremor is not necessarily associated with 123I‐FP‐CIT SPECT abnormalities, as 8 of our patients had more than a 10‐year history of OT. Primary orthostatic tremor without dopaminergic denervation remains a valid entity, although representing only a subtype of high‐frequency OT. A new role may emerge for 123I‐FP‐CIT SPECT in distinguishing between patients whose symptoms will be restricted to OT throughout the disease course and patients at an increased risk of developing PD. © 2008 Movement Disorder Society
Generalized and neurotransmitter‐selective noradrenergic denervation in Parkinson's disease with orthostatic hypotension
Authors: Sharabi Yehonatan , Imrich Richard , Holmes Courtney , Pechnik Sandra , Goldstein David S
Published: July 2008

Patients with Parkinson's disease (PD) often have manifestations of autonomic failure. About 40% have neurogenic orthostatic hypotension (NOH), and among PD+NOH patients virtually all have evidence of cardiac sympathetic denervation; however, whether PD+NOH entails extra‐cardiac noradrenergic denervation has been less clear. Microdialysate concentrations of the main neuronal metabolite of norepinephrine (NE) and dihydroxyphenylglycol (DHPG) were measured in skeletal muscle, and plasma concentrations of NE and DHPG were measured in response to i.v. tyramine, yohimbine, and isoproterenol, in patients with PD+NOH, patients with pure autonomic failure (PAF), which is characterized by generalized catecholaminergic denervation, and control subjects. Microdialysate DHPG concentrations were similarly low in PD+NOH and PAF compared to control subjects (163 ± 25, 153 ± 27, and 304 ± 27 pg/mL, P < 0.01 each vs. control). The two groups also had similarly small plasma DHPG responses to tyramine (71 ± 58 and 82 ± 105 vs. 313 ± 94 pg/mL; P < 0.01 each vs. control) and NE responses to yohimbine (223 ± 37 and 61 ± 15 vs. 672 ± 130 pg/mL, P < 0.01 each vs. control), and virtually absent NE responses to isoproterenol (20 ± 34 and 14 ± 15 vs. 336 ± 78 pg/mL, P < 0.01 each vs. control). Patients with PD+NOH had normal bradycardia responses to edrophonium and normal epinephrine responses to glucagon. The results support the concept of generalized noradrenergic denervation in PD+NOH, with similar severity to that seen in PAF. In contrast, the parasympathetic cholinergic and adrenomedullary hormonal components of the autonomic nervous system seem intact in PD+NOH. © 2008 Movement Disorder Society
Relationship between thermal index and mortality in Hong Kong
Authors: Leung Y. K. , Yip K. M. , Yeung K. H.
Published: July 2008

In summer (May–September), deaths associated with heat stroke are found to occur when the daily maximum net effective temperature (NET) exceeds 26. Using Poisson regression, it is estimated that the mean mortality associated with heat stroke would double per unit rise in NET beyond 26. In contrast to those in most temperate regions, the daily mortality for circulatory and respiratory related causes of death is not statistically correlated to the daily maximum NET or temperature in summer. In winter (November–March), there are statistically significant negative‐lagged correlations between the daily minimum NET and the daily mortality attributed to circulatory and respiratory diseases. The increase in mortality per unit decrease in NET is found to be the highest for hypothermia, and slightly higher for circulatory causes than respiratory causes. Deaths associated with hypothermia start to occur when the daily minimum NET is less than 14 and the mean mortality is estimated to increase by about 1.3‐fold per unit fall in NET below 14. The elderly age group (age ≧ 65 years) is found to be more vulnerable to NET changes when compared to other age groups. Copyright © 2008 Royal Meteorological Society
A positron annihilation study on the microstructure of cyanate ester resin toughened by carboxyl‐terminated butadiene‐acrylonitrile rubber system
Authors: Zeng Minfeng , Sun Xudong , Wang Yun , Zhang Mingzhu , Shen Yongmiao , Wang Baoyi , Qi Chenze
Published: July 2008

The toughness of cyanate ester (CE) resin matrix improves significantly with the addition of carboxyl‐terminated butadiene‐acrylonitrile rubber (CTBN). The curing behavior of the system was studied by differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy. The results show that carboxyl groups on the CTBN chain have a slight activation effect on the CE curing reaction at the beginning of the curing process. Phase separation was found to be the main toughening mechanism for CE/CTBN composites. The existence of macro‐size pores induced by the decomposition of a small amount of the low weight molecular part of CTBN might be another toughening mechanism. It is confirmed that positron annihilation lifetime spectroscopy (PALS) is still valid in such a system where macropores filled with gas molecules exist. When a high weight percentage of CTBN (>8%) was added to CE, free‐positron annihilation was found to be the dominant annihilation process in the macropores. For CTBN weight percentage higher than 8%, the contribution of ortho‐positronium (o‐Ps) annihilation in the macropores to τ3 and I3 was found to be insignificant. It is effective to use PALS as a probe of free‐volume properties in such systems by determining the changes in the τ3 and I3 of the composite. The compatibility and interfacial adhesion of the composites can be estimated from the changes in the free‐volume properties of the composites. Copyright © 2008 John Wiley & Sons, Ltd.
Preparation and properties of aramid/layered silicate nanocomposites by solution intercalation technique
Authors: Zulfiqar Sonia , Ahmad Zahoor , Sarwar Muhammad Ilyas
Published: July 2008

Polymer—clay nanocomposites were synthesized from aromatic polyamide and organoclay using the solution intercalation technique. Polyamide chains were produced through the reaction of 4,4′‐oxydianiline (ODA) and isophthaloyl chloride (IPC) in N, N′‐dimethyl acetamide, using stoichiometry yielding chains with carbonyl chloride end groups. The intercalation of sodium montmorillonite (Na‐MMT) was carried out using p‐phenylene diamine as a swelling agent through an ion exchange reaction. Different concentrations of organoclay were blended with the polyamide solution for complete dispersion of clay throughout the matrix. The resulting composite films were characterized by X‐ray diffraction (XRD), transmission electron microscopy (TEM), mechanical testing, thermogravimetry (TGA), differential scanning calorimetry (DSC) and water absorption measurements. The XRD pattern and morphology of the nanocomposites revealed the formation of exfoliated and intercalated clay platelets in the matrix. The film containing a small amount of clay was semitransparent and had a tensile strength of the order of 70 MPa (relative to the 52 MPa of the pure aramid). Thermal decomposition temperatures were in the range of 300–450°C and the weight of the samples remaining after heating to 900°C was found to be roughly proportional to the clay loading. DSC showed a systematic increase in the glass transition temperature with increase in clay content. Water absorption of the pristine aramid film was rather high (5.7%), which reduced upon loading of organoclay. Copyright © 2008 John Wiley & Sons, Ltd.
Improving CO2 permeability in polymerized room‐temperature ionic liquid gas separation membranes through the formation of a solid composite with a room‐temperature ionic liquid
Authors: Bara Jason E. , Hatakeyama Evan S. , Gin Douglas L. , Noble Richard D.
Published: July 2008

Room‐temperature ionic liquids (RTILs) present a number of unique opportunities for the processing and tailoring of polymer materials for applications including ion conduction polymers, catalysis, and gas separations. Perhaps most importantly, RTILs can be synthesized as monomers and polymerized in the presence of non‐polymerizable RTILs to provide solid composites with enhanced properties. These features allow for the formation of poly(RTIL)–RTIL composite gas separation membranes, exhibiting hybrid properties of both RTILs and polymers. Incorporation of just 20 mol% free RTIL in the polymer membrane yields a stable composite material with a CO2 permeability increase of ∼400% with a 33% improvement to CO2/N2 selectivity relative to the analogous poly(RTIL) membrane lacking any free ion pairs. The composite membrane also showed a significant improvement in CO2/CH4 separation compared to other poly(RTILs) when analyzed via “Robeson Plots.” This new approach to polymer gas separation membranes provides a powerful method to improve the performance of current materials without intensive organic synthesis. Copyright © 2008 John Wiley & Sons, Ltd.
Organic–inorganic nanocomposites of (2‐hydroxypropyl)cellulose as a precursor of nanocrystalline zinc oxide layers
Authors: Bobowska Izabela , Wojciechowski Piotr , Halamus Tomasz
Published: July 2008

The sol–gel method of synthesis of the hybrid nanocomposite films of ZnO/(2‐hydroxypropyl) cellulose (HPC) on silica glass is presented. The sol phases were prepared for different weight ratios of zinc acetate dihydrate to HPC in the presence of triethylamine (TEA). Raman spectrum of the mixture of ZnAc and HPC indicates coordinating interaction between zinc ion and HPC. The generation of ZnO nanoparticles in the HPC matrix proceeds in situ through the annealing of the gel phase at a temperature of 160°C. Identification of ZnO nanoparticles in the HPC matrix is done by using photoluminescence (PL), UV–Vis, and Raman spectroscopy. The films of ZnO/HPC nanocomposite are transparent in the visible light and show a higher energy value of absorption edge compared with ZnO in the bulk. Nanocrystalline films of ZnO were obtained by the calcination of ZnO/HPC nanocomposite at 500°C. ZnO films possess a good transparency for the visible light and high absorbance for UV light. Nanocrystallite sizes of ZnO particles were estimated from the X‐ ray lines broadening. The properties of ZnO layers were studied by the evaluation of PL, X‐ray investigation and atom force microscope (AFM) scanning, and the optical absorption edge. Copyright © 2008 John Wiley & Sons, Ltd.
Screening, identification, and functional analysis of three novel missense mutations in the TRADD gene in children with ALL and ALPS
Authors: Dechant M.J. , Scheuerpflug C.G. , Pauly E. , van der Werff Ten Bosch J. , Debatin K.M. , Fellenberg J.
Published: July 2008

Background

Apoptosis is known to be a crucial process involved in embryogenesis, development and homeostasis of the immune system. Impaired apoptosis causes dysfunction of lymphocyte homeostasis, growth advantage of tumor cells as well as resistance to current treatment protocols. To investigate the role of the apoptosis adaptor molecules TRADD and FADD in the development of hematological diseases, patient samples were screened for mutations in these genes.

Procedure

Genomic DNA from 51 children suffering from B‐lineage‐ALL (n = 17), T‐lineage‐ALL (n = 24), ALPS Type Ia (n = 3) and ALPS Type III (n = 7) were analyzed. Genomic DNA from 50 unrelated donors without hematological diseases served as controls. Identified mutations were cloned and their influence on cell viability and NFκB activation was analyzed by flow cytometry and luciferase assay, respectively.

Results

In the FADD gene no genetic alteration could be detected. However, three novel missense mutations in the TRADD gene could be detected. They are located within a region of TRADD known to exert mainly anti‐apoptotic effects for example through the activation of the NFκB pathway. Functional analysis of cells overexpressing mutant TRADD cDNA demonstrated a reduced NFκB activity and consequently increased cell death compared to wild‐type TRADD.

Conclusion

Mutations in the TRADD gene may contribute to the development of different hematological diseases. The identified mutations demonstrate a putative impact on TRADD signaling and cell survival but may not mainly explain the pathology of the diseases investigated. Pediatr Blood Cancer 2008;51:616–620. © 2008 Wiley‐Liss, Inc.
Intermittent chronic neutropenia in a patient with familial Mediterranean fever
Authors: Ganiou Tidjani K. , Ailal F. , Najib J. , Bellanné‐Chantelot C. , Donadieu J. , Bousfiha A.A.
Published: July 2008

A 12‐year‐old daughter of consanguineous Moroccan parents was diagnosed with cyclic neutropenia, based on a combination of recurrent gingivostomatitis, a fluctuating neutrophil count, and several episodes of severe neutropenia. No ELA2 gene mutations were found. At age 19 years she presented with edema of the limbs, proteinuria and renal failure. Renal amyloidosis AA was diagnosed by biopsy. Gene mutations associated with family Mediterranean fever (FMF) were sought, and a homozygous mutation (M694V) was found in the MFEV gene. This is the novel finding of FMF that masqueraded as cyclic neutropenia. Pediatr Blood Cancer 2008;51:701–703. © 2008 Wiley‐Liss, Inc.
Hereditary retinoblastoma transmitted by maternal germline mosaicism
Authors: Barbosa Raquel H. , Vargas Fernando R. , Aguiar Fernanda C.C. , Ferman Sima , Lucena Evandro , Bonvicino Cibele R. , Seuánez Héctor N.
Published: July 2008

Background

Investigating transmission of a constitutive, g78238C > T (R552X), RB1 mutation in four affected children descended from three different unaffected fathers and an unaffected mother.

Procedures

Sequence data analyses and allele‐specific PCR assays were used to investigate the presence of the mutation in four affected children, five unaffected sibs (or half‐sibs), and the unaffected mother. Haplotyping was carried out for confirming that the children descended from different fathers.

Results

Haplotyping excluded the possibility of paternal transmission of a de novo mutation and provided evidence of maternal germline mosaicism. The mutation was apparently absent in blood‐ and buccal cell‐DNA of the mother who also showed a normal fundoscopy.

Conclusions

Our findings indicated that mosaicism was restricted to the maternal germline. The mutational event must have occurred at least 4 weeks post‐conception, unlike the early mutational events of most mosaics, occurring between fertilization and the 8th day of conception. The implications of these findings are discussed in view that genetic counselling should discriminate between germline mosaicism and de novo events in pseudo‐low‐penetrant hereditary retinoblastoma. Pediatr Blood Cancer 2008;51:598–602. © 2008 Wiley‐Liss, Inc.
Encephalopathy syndrome in children with hemato‐oncological disorders is not always posterior and reversible
Authors: Lucchini Giovanna , Grioni Daniele , Colombini Antonella , Contri Margherita , De Grandi Carlo , Rovelli Attilio , Conter Valentino , Masera Giuseppe , Jankovic Momcilo
Published: July 2008

Background

Posterior reversible leukoencephalopathy (PRES) is a clinical‐radiological event that can affect children undergoing chemotherapy regimen. Studies have shown that it is not always reversible, in spite of its original definition. We analyzed PRES cases which occurred during the last 10 years at our institute to focus on their clinical, radiological and EEG follow‐up.

Procedures

We analyzed 12 cases of PRES in children who underwent intensive chemotherapy regimens, detailing the acute neurological presentation of the syndrome, their neuro‐imaging characteristics (MRI) and EEG findings, in both an acute phase and during follow‐up.

Results

All patients survived the acute event, showing a clinical recovery of the acute neurological signs in 1–3 days and normalization of the EEG pattern in a period ranging from 1 to 8 months. During long term follow‐up, four patients developed either clinical impairment or EEG‐MRI anomalies.

Conclusions

We suggest that a long term follow‐up is necessary to determine the reversibility of the neurological events. Clinical observation, as well as EEG and MRI should be included in follow‐up evaluations. Pediatr Blood Cancer 2008;51:629–633. © 2008 Wiley‐Liss, Inc.
Current awareness in prenatal diagnosis
Authors:   John Wiley & Sons, Ltd.
Published: July 2008

In order to keep subscribers up‐to‐date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of prenatal diagnosis. Each bibliography is divided into 17 sections: 1 Reviews; 2 General Interest; 3 Normal Fetal Development; 4 Gametogenesis and Pre‐implantation Diagnosis; 5 First Trimester Diagnosis; 6 Second Trimester Diagnosis; 7 Fetal Diagnosis by Ultrasound and Other Imaging; 8 Maternal Screening; 9 Screening for Carriers of Genetic Abnormality; 10 Technological Developments; 11 Confined Placental Mosaicism and Uniparental Disomy; 12 Molecular Cytogenetics; 13 Fetal Cells in Maternal Circulation; 14 Fetal Therapy; 15 Psychosocial Aspects; 16 Epidemiology and Environmental Factors; 17 Developmental Pathology. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted
Prader‐Willi syndrome: is there a recognizable fetal phenotype?
Authors: Bigi Nicole , Faure Jean‐Michel , Coubes Christine , Puechberty Jacques , Lefort Geneviève , Sarda Pierre , Blanchet Patricia
Published: July 2008

Objectives

To determine fetal features, which could lead to the diagnosis of Prader‐Willi syndrome (PWS) during pregnancy.

Methods

We analyze the ultrasound features, genetic studies and pathologic findings in two cases of PWS diagnosed during pregnancy.

Results

In the first case, diminished fetal movement, polyhydramnios and oddly positioned hands and feet suggested PWS. Methylation studies confirmed diagnosis and a deletion was detected in the 15q11‐q13 region. In the second case, similar ultrasound findings led to prenatal diagnosis of PWS with an abnormal methylation pattern compatible with uniparental disomy. Both fetuses had a characteristic appearance at 28 and 30 weeks' gestation, which included a peculiar position of hands with flexed wrists and dorsi‐extended feet with flexed toes.

Conclusions

The peculiar position of the extremities combined with diminished fetal movement and polyhydramnios seems to be characteristic and should suggest PWS. Copyright © 2008 John Wiley & Sons, Ltd.
Informed choice to undergo prenatal screening for thalassemia: a description of written information given to pregnant women in Europe and beyond
Authors: Van den Heuvel Ananda , Hollywood Amelia , Hogg Julie , Dormandy Elizabeth , Chitty Lyn , Kabra Madhulika , Ma Runmei , Masturzo Bianca , Marteau Theresa M.
Published: July 2008

Purpose

To investigate whether prenatal screening for thalassemia is presented as a choice, and how the condition is described in written information given to pregnant women in different countries.

Method

One leaflet from each of seven countries (UK, The Netherlands, Greece, Italy, Israel, India and China) was collected for evaluation. Statements relating to choice and those describing the condition were extracted for analysis.

Results

The leaflets varied in length from 26 to 74 sentences (mean: 42). Overall, more sentences were devoted to describing the condition (mean: 5) than to conveying choice (mean: 2). Leaflets from Northern Europe contained the highest proportion of sentences relating to choice, while those from Italy and Israel contained none. The majority of sentences describing thalassemia were classified as negative. The leaflets from China and India contained the highest proportion of negative sentences and the leaflets from the Netherlands and Italy, the lowest.

Conclusion

For women to make an informed decision they need to be offered a choice and given balanced information regarding the condition for which screening is being offered. The results of this study raise doubts as to the extent to which prenatal services in many countries are facilitating informed choices. Copyright © 2008 John Wiley & Sons, Ltd.
Down syndrome biochemical markers and screening for preeclampsia at first and second trimester: correlation with the week of onset and the severity
Authors: Kang Jin Hee , Farina Antonio , Park Ji Hyeon , Kim Sung Han , Kim Ji Yeon , Rizzo Nicola , Elmakky Amira , Jun Hye Sun , Hahn Won Bo , Cha Dong Hyun
Published: July 2008

Objectives

To estimate the combined screening performance of first and early second trimester prenatal serum markers for Down syndrome, in screening for the development of preeclampsia, and analyze the correlation among marker levels, week of onset, and severity of the disease.

Methods

A retrospective cohort study was carried out on 32 women with preeclampsia and 3044 controls. Serum samples from these pregnancies were assayed for pregnancy‐associated plasma protein‐A (PAPP‐A), alpha‐fetoprotein (AFP), unconjugated estriol (uE3), human chorionic gonadotrophin (hCG), and inhibin‐A. A likelihood ratio and the odds of being affected given a positive result (OAPR) of various combinations of markers were calculated and receiver operating characteristic (ROC) curves analysis was performed.

Results

In the pregnancies that subsequently developed preeclampsia, first trimester PAPP‐A concentration was significantly lower and concentrations of early second trimester inhibin‐A and hCG significantly elevated. Levels of early second trimester uE3 and AFP were not significantly altered. We also found that inhibin‐A correlates with both onset of the disease and the severity.

Conclusion

Down syndrome biochemical markers levels are altered in those patients who subsequently developed preeclampsia and may be a useful screening test for preeclampsia. Inhibin‐A is the most predictive marker and correlates with the severity of subsequent preeclampsia and inversely with the week of occurrence of preeclampsia. Copyright © 2008 John Wiley & Sons, Ltd.
Prediction of superimposed preeclampsia using uterine artery Doppler velocimetry in women with chronic hypertension
Authors: Roncaglia Nadia , Crippa Isabella , Locatelli Anna , Cameroni Irene , Orsenigo Francesca , Vergani Patrizia , Ghidini Alessandro
Published: July 2008

Objective

To assess the role of uterine artery (UtA) Doppler to predict superimposed preeclampsia in women with chronic hypertension.

Methods

In a cohort of 182 women with chronic hypertension, UtA Doppler studies were performed before 25 weeks (mean 19.7 ± 2.1 weeks) and repeated later in pregnancy (mean 28.5 ± 3.7 weeks).

Results

The incidence of preeclampsia was 13% (24/182). Rates of preeclampsia increased with advancing gestation of abnormal UtA Doppler: 7% when UtA Doppler were normal at early exam, 18% when abnormal at early exam, and 28% when abnormal at late exam (Chi‐square for trend: P < 0.001). The rate of preeclampsia among 40 women with abnormal early but normal late UtA Doppler was similar to that of women with normal findings at early exam (8 vs 7%; P = 1.00). Logistic regression analysis showed that the ability of UtA Doppler to predict preeclampsia was independent from other variables [Odds Ratio (OR) 7.1, 95% Confidence Interval (CI) 2.6–18.9). Receiver operating characteristic (ROC) curve identified a UtA value of 0.58 as the optimal threshold for the prediction of preeclampsia.

Conclusion

The later in pregnancy the abnormal UtA Doppler findings are observed, the greater the risk of preeclampsia. Normalization of UtA Doppler after 25 weeks reduces the risk of preeclampsia to 8%. Copyright © 2008 John Wiley & Sons, Ltd.
Morphology and glass transition of thin polylactic acid films
Authors: Narladkar A. , Balnois E. , Vignaud G. , Grohens Y. , Bardeau J.‐F.
Published: July 2008

The aim of this study is to highlight the effect of the morphology of polylactic acid (PLA) thin films on the glass transition in this confined geometry. For that purpose, poly(L‐lactic acid) and poly(D‐lactic acid) polymer films were prepared on different surfaces such as mica and silicon surfaces by using two different solvents. The films exhibit different morphologies starting from individual macromolecular chains at very low concentration to homogeneous films at higher concentrations. Globular to elongated rodlike structures of the PLA macromolecules were observed according to the polarity of the surface and the solvent. The Tg of PLA enantiomeric film, determined by adhesion force using atomic force microscopy (AFM) as a function of temperature, was confirmed by ellipsometric measurements. Surprisingly, this value is independent of the morphology of thin enantiomeric film. A balance between the attractive surface effects and a decrease of the crystallinity of PLA on the mobility in the amorphous region will be discussed. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Natural rubber nanocomposite reinforced with nano silica
Authors: Chen Ying , Peng Zheng , Kong Ling Xue , Huang Mao Fang , Li Pu Wang
Published: July 2008

Inorganic nano fillers have demonstrated great potential to enhance the properties of natural rubber (NR). The present article reports the successful development of a NR nanocomposite reinforced with nano silica (SiO2). Its dynamic mechanical properties, thermal aging resistance, and morphology are investigated. The results show that the SiO2 nanoparticles are homogenously distributed throughout the NR matrix in a form of spherical nano‐cluster with an average size of 80 nm when the SiO2 content is 4 wt%. With the introduction of SiO2, the thermal resistance and the storage modulus of NR host significantly increase, and the activation energy of relaxation of the nanocomposite, compared to the raw NR, increases from 90.1 to 125.8 kJ/mol. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Increasing the efficiency of the extrusion process
Authors: Sikora Janusz W.
Published: July 2008

The article presents constructional methods of increasing the efficiency of the polymer extrusion process. Increasing the efficiency of the polymer extrusion process consists in the increase of the flow rate of the processed polymer and the energy efficiency of polymer processing extruders and the decrease of the specific energy consumption and the pulsation of the flow rate and polymer pressure, as well as quality improvement of the received extrudate as a result of better homogenization of mechanical and thermal properties and polymer structure. Therefore, the improvement of the constructional solution of the screw and barrel of the extruder plasticating system was discussed. The improvement of the construction of the screw lies in using the active and passive grooved barrel section. Original constructional solutions of the active grooved section with both longitudinal and helical grooves were shown. The devices increasing the efficiency of the extrusion were also shown, which included a screen changer, a melt pump, and a static mixer. Appropriate conclusions were drawn. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Miscibility, melting, and crystallization behavior of poly(hydroxybutyrate) and poly(D,L‐lactic acid) blends
Authors: Gunaratne L.M. Wasantha K. , Shanks R.A.
Published: July 2008

Melting behavior and crystal morphology of poly(3‐hydroxybutyrate)‐poly(D,L‐lactic acid) (PHB‐RPLA) blends with various compositions have been investigated by modulated temperature differential scanning calorimetry (mt‐DSC), polarized optical thermomicroscopy (POTM), modulated force thermomechanometry (mf‐TM), and small angle X‐ray scattering (SAXS). Thermal properties were investigated after fast cooling crystallization treatment. Multiple melting peak behavior was observed for all polymers. mt‐DSC data revealed that PHB‐RPLA blends undergo melting‐recrystallization‐remelting during heating, as evidenced by exothermic peaks in the nonreversing heat capacity. A decrease in degree of crystallinity due to significant melt‐recrystallization was observed for blends. PHB‐RPLA showed different crystal morphologies for various compositions. POTM results showed that the crystallization rates and sizes of spherulites were significantly reduced as RPLA content increased. mf‐TM results confirmed miscibility of these two polymers. SAXS data provided evidence of lamella thickness of blends, which increased with increasing RPLA content. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Numerical prediction of phase‐change heat conduction of injection‐molded high density polyethylene thick‐walled parts via the enthalpy transforming model with mushy zone
Authors: Yang Bin , Fu Xiao‐Rong , Yang Wei , Huang Li , Yang Ming‐Bo , Feng Jian‐Min
Published: July 2008

Transient heat transfer problems with phase‐changes, also known as the “Stefan problems” or “moving‐boundary problems,” are practically significant in many engineering and technological fields. Injection molding, one of the most widely used plastics processing techniques, mainly consists of filling, packing, and cooling, and the cooling stage is crucial since it considerably affects the productivity and quality of the molded parts. Thus, solutions for transient phase‐change heat conduction problems during injection molding will be instructive. In this article, the enthalpy transforming scheme proposed by Cao and Faghri, which could handle the Stefan problems for generalized multidimensional phase‐change structures, is applied coupled with the control‐volume/finite‐difference techniques. Considering the polydispersity and hierarchical structures, the polymer extended phase change temperature range or mushy zone was included in the two‐dimensional enthalpy formulation to forecast the transient phase‐change heat conduction during the cooling stage for injection‐molded high density polyethylene (HDPE) parts. Experiments were performed and good agreement has been achieved, which reveals that the enthalpy transforming model gives good prediction, especially for the cooling analysis for the injection molding of thick‐walled parts of crystalline polymers. The understanding of the phase‐change heat conduction characteristics may facilitate the optimal designs of polymer injection molding process for industrial applications. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Microstructure and water vapor transport properties of functionalized carbon nanotube‐reinforced dense‐segmented polyurethane composite membranes
Authors: Mondal S. , Hu J.L.
Published: July 2008

This work investigates the influence of functionalized multiwall carbon nanotube (MWNT) on microstructure and water vapor transport properties of segmented polyurethane (SPU) membranes. SPUs were reinforced with four different concentration of MWNT viz. 0.25, 0.50, 1.0, and 2.5 wt%. Presence of the microcrystals in all SPU‐MWNT composite membranes was detected by wide angle X‐ray diffraction (WAXD). The percent crystallinity of SPU‐MWNT at 0.25 wt% content of MWNT was increased slightly when compared with the pristine SPU sample. However, further increase of MWNT decreases the order structure. Glass transition temperature was increases with increasing MWNT content in the SPUs, which signifies that MWNT could also affect the amorphous region of SPU. WAXD and transmission electron microscopy (TEM) results evidenced the interaction between SPUs and MWNT. In comparing the water vapor transport properties of MWNT‐SPU composite membranes, it was observed that at 0.25 wt% of MWNT in SPU, water vapor transport property increases slightly at soft segment crystal melting temperature. Further increase of MWNT content has no significant influence on the water vapor transport properties. However, at 2.5 wt% of MWNT in SPU matrix, water vapor transport was decreases due to the increase of stiffness in the polymer chains. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
A simplified approach to predict part temperature and minimum “safe” cycle time
Authors: Hioe Yunior , Chang Keh‐Chyou , Zuyev Konstantin , Bhagavatula Narayan , Castro Jose M.
Published: July 2008

The largest component of the injection molding cycle is the cooling time. Thus it is highly desirable, to be able to predict what its minimum acceptable value can be. This is becoming even more important with increased competition from regions where the labor cost is low. In an injection molding operation, the mold thermal state changes from its initial value until a quasi steady state is reached. The minimum required cooling time increases with continuous molding until a steady state value is achieved. Improving the mold thermal design will decrease the cooling time thus reducing total cycle time. The overall goal of this work is to develop a simple reliable method to predict a minimum safe cycle time for steady production. In this article, we discuss software capable of simulating the thermal state of the part and mold for multiple injection molding cycles while balancing simulation time with results accuracy. Three case studies are presented, one done in our labs and two on‐site at an automotive manufacturing facility. The three case studies are used to evaluate the ability of the software to predict part surface temperature for continuous molding. We also discuss how this software can be used as the basis to establish the minimum safe cycle time. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
In situ compatibilization of maleated thermoplastic starch/polyester melt‐blends by reactive extrusion
Authors: Raquez Jean‐Marie , Nabar Yogaraj , Narayan Ramani , Dubois Philippe
Published: July 2008

This article concerns the utilization of maleated thermoplastic starch (MTPS) in the reactive extrusion melt‐blending with poly(butylene adipate‐co‐terephthalate) (PBAT) in blown film applications. First, MTPS was prepared from cornstarch with glycerol (plasticizer) and maleic anhydride (MA; esterification agent). MTPS was then melt‐blended with PBAT in a subsequent downstream extrusion operation. The effects of both polyester and MA contents were studied on the physicochemical parameters of melt‐blends. For high polyester fractions (>60 wt%), PBAT‐g‐MTPS graft copolymers were obtained through transesterification reactions. They were promoted by the MA‐derived acidic moieties grafted onto the starch backbone as shown by selective Soxhlet extraction experiments and FTIR analyses. At lower polyester content, no significant reaction occurred more likely due to an inversion in the phase morphology between both components. Tensile properties of PBAT‐g‐MTPS graft copolymer containing 70 wt% polyester were much higher as the TPS/PBAT melt‐blend modified with MA. This can be explained by a finer morphology of the dispersed phase in the continuous PBAT matrix, and an increased interfacial area for the grafting reaction as attested by morphological studies. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers.