bluuebunny/crossref_metadata_2025 huggingface dataset:
Autocall
Authors: Roubinet Charles‐Henri
Published: May 2010

An equity‐linked autocallable note is a legal instrument in which the notional engaged by the customer is automatically reimbursed when the underlying stock reaches a strike at a specified recalling date or at maturity if such an event does not occur (when the recall appends a coupon is also paid to give the client a return on his/her capital higher than the one he/she would get from an investment in a bond). Because the date of the reimbursement of the capital is unknown, it is necessary to use a joint equity/interest rate model for the computation of the price and sensitivities of this product. Integrating the equity smile risk and the dividend risk can also be required, but it is much more complex with an interest rate factor: the local volatility formula does not hold anymore and convexity adjustments appear with fixed discrete dividends.
Municipal Bonds
Authors: Namvar Ethan
Published: May 2010

Municipal bonds are bonds issued by local and state governments to raise funds for public works with interest payment(s) that are generally exempt from federal taxes, and often from state and local taxes as well.
Asset–Liability Management
Authors: Ziemba William T.
Published: May 2010

Asset–liability management is a major concern for large financial institutions. Assets must be invested to achieve sufficient returns to pay liabilities and achieve goals subject to uncertainties, policy, taxes, and legal constraints. This article discusses asset and liability management with portfolio complexities and policy constraints. Applications to the management of investment portfolios for large financial institutions, including pension funds and insurance companies, and for individual life‐cycle planning are discussed. The approach recommended is discrete‐time, multiperiod stochastic programming. We present the Russell–Yasuda Kasai and the InnoALM models, both of which had a major impact on the practice of asset‐liability management (ALM).
Passport Options
Authors: Henderson Vicky
Published: May 2010

This article outlines the pricing and hedging of an exotic option called a
passport option
. The passport option was invented in the mid‐1990s by quantitative analysts at Bankers Trust and this falls into the more general class of products called
options on traded accounts
. The buyer of a passport option pays a premium and trades in an underlying asset (up to predefined limits). At expiry, the buyer receives any profit on this account, but is not responsible for losses. For this reason, the option has also been called a
perfect trader option
. In a general framework, the passport option is related to a lookback option, a “best price” option.
Reinsurance
Authors: Albrecher Hansjörg
Published: May 2010

In this article, the notion of reinsurance as a means for a first‐line insurer to pass on part of his underwritten risk for some appropriate premium payment is defined and motivated. Various forms of common reinsurance treaties of proportional and nonproportional types are described, including quota‐share, surplus, excess‐of‐loss, stop‐loss, and large‐claim treaties. Some actuarial and practical challenges in connection with the determination of suitable premiums for the reinsured risk are discussed. Subsequently, main obstacles in deciding upon the choice of the appropriate reinsurance form in a given situation are treated, which often can be expressed as an optimization problem with an objective function under constraints. Finally, connections between reinsurance and the realm of finance are discussed. Throughout the article, references to the literature and links to other articles are provided.
Insurance Derivatives
Authors: Cheung KA Chun
Published: May 2010

Insurance derivatives are financial instruments that are related to insurance. Typical examples include catastrophe derivatives and equity‐linked insurance products. In this article, we present a brief introduction to these products, examine various stochastic models proposed in the literature, and address their pricing and hedging issues.
Cramér's Theorem
Authors: Tang Qihe
Published: May 2010

For a sequence of independent and identically distributed random variables whose moment‐generating function is finite in a neighborhood of the origin, Cramér's theorem gives a simple method to identify the exponential decay rate of the small probabilities that the empirical means are away from the population mean. In this article, we briefly review Cramér's theorem and related results in the context of large deviation theory.
Accumulated Claims
Authors: Schmidli Hanspeter
Published: May 2010

We consider models for the accumulated claim sizes, as they can, for instance, be used for modeling
operational risk
. A natural model consists of compound distributions. These models are difficult to handle. Modeling the accumulated claim sizes directly leads to simple approximations such as the normal approximation or the translated gamma approximation. Finally, numerical methods are successful for discrete compound distributions that are in the Panjer class of distributions.
Ruin Models with Investment Income
Authors: Paulsen Jostein
Published: May 2010

A rather general risk model compounded by a stochastic return process is presented, together with integral–differential equations for the ruin probability. Exact solutions, numerical solutions, and asymptotic properties are discussed.
Life Insurance
Authors: Steffensen Mogens
Published: May 2010

We give a survey of the mathematics of life insurance and some of its most important connections to quantitative finance. We model and valuate the payment stream of a life insurance contract on the basis of the insurance valuation principle, that is, diversification of risk. We discuss connections between this principle and the financial valuation principle of no arbitrage. We also see how quantitative finance helps in relaxing some of the strict assumptions on which diversification is based. We present different designs of contracts, including with‐profit life insurance and unit‐linked life insurance. They are classcial contract designs with so‐called participation features, that is, features that allow the policy holder to participate in the surplus of the insurance company or the capital gains on an investment portfolio. Finally, we discuss connections between the decision problems appearing from these contract designs and classical financial consumption–investment decision problems.
Quantification of Grafting Densities Achieved via Modular “Grafting‐to” Approaches onto Divinylbenzene Microspheres
Authors: Nebhani Leena , Schmiedl Detlef , Barner Leonie , Barner‐Kowollik Christopher
Published: May 2010

The surface modification of divinylbenzene (DVB)‐based microspheres is performed via a combination of reversible addition fragmentation chain transfer (RAFT) polymerization and rapid hetero‐Diels–Alder (HDA) chemistry with the aim of quantifying the grafting densities achieved using this “grafting‐to” method. Two variants of the RAFT‐HDA concept are employed to achieve the functionalization of the microspheres. In the first approach, the microspheres are functionalized with a highly reactive diene, i.e., cyclopentadiene, and are subsequently reacted with polystyrene chains (number‐averaged molecular weight, Mn = 4200 g mol−1; polydispersity index, PDI = 1.12.) that carry a thiocarbonyl moiety functioning as a dienophile. The functionalization of the microspheres is achieved rapidly under ambient conditions, without the aid of an external catalyst. The surface grafting densities obtained are close to 1.2 × 1020 chains per gram of microspheres. In the second approach, the functionalization proceeds via the double bonds inherently available on the microspheres, which are reacted with poly(isobornyl acrylate) chains carrying a highly dienophilic thiocarbonyl functionality; two molecular weights (Mn = 6000 g mol−1, PDI = 1.25; Mn = 26 000 g mol−1, PDI = 1.26) are used. Due to the less reactive nature of the dienes in the second approach, functionalization is carried out at elevated temperatures (T = 60 °C) yet in the absence of a catalyst. In this case the surface grafting density is close to 7 chains nm−2 for Mn = 6000 g mol−1 and 4 chains nm−2 for Mn = 26 000 g mol−1, or 2.82 × 1019 and 1.38 × 1019 chains g−1, respectively. The characterization of the microspheres at various functionalization stages is performed via elemental analysis for the quantification of the grafting densities and attenuated total reflectance (ATR) IR spectroscopy as well as confocal microscopy for the analysis of the surface chemistry.
The Role of Transition Metal Oxides in Charge‐Generation Layers for Stacked Organic Light‐Emitting Diodes
Authors: Hamwi Sami , Meyer Jens , Kröger Michael , Winkler Thomas , Witte Marco , Riedl Thomas , Kahn Antoine , Kowalsky Wolfgang
Published: May 2010

The mechanism of charge generation in transition metal oxide (TMO)‐based charge‐generation layers (CGL) used in stacked organic light‐emitting diodes (OLEDs) is reported upon. An interconnecting unit between two vertically stacked OLEDs, consisting of an abrupt heterointerface between a Cs2CO3‐doped 4,7‐diphenyl‐1,10‐phenanthroline layer and a WO3 film is investigated. Minimum thicknesses are determined for these layers to allow for simultaneous operation of both sub‐OLEDs in the stacked device. Luminance–current density–voltage measurements, angular dependent spectral emission characteristics, and optical device simulations lead to minimum thicknesses of the n‐type doped layer and the TMO layer of 5 and 2.5 nm, respectively. Using data on interface energetic determined by ultraviolet photoelectron and inverse photoemission spectroscopy, it is shown that the actual charge generation occurs between the WO3 layer and its neighboring hole‐transport material, 4,4',4”‐tris(N‐carbazolyl)‐triphenyl amine. The role of the adjacent n‐type doped electron transport layer is only to facilitate electron injection from the TMO into the adjacent sub‐OLED.
Synthesis, Functionalization, and Biomedical Applications of Multifunctional Magnetic Nanoparticles
Authors: Hao Rui , Xing Ruijun , Xu Zhichuan , Hou Yanglong , Gao Song , Sun Shouheng
Published: May 2010

Synthesis of multifunctional magnetic nanoparticles (MFMNPs) is one of the most active research areas in advanced materials. MFMNPs that have magnetic properties and other functionalities have been demonstrated to show great promise as multimodality imaging probes. Their multifunctional surfaces also allow rational conjugations of biological and drug molecules, making it possible to achieve target‐specific diagnostics and therapeutics. This review first outlines the synthesis of MNPs of metal oxides and alloys and then focuses on recent developments in the fabrication of MFMNPs of core/shell, dumbbell, and composite hybrid type. It also summarizes the general strategies applied for NP surface functionalization. The review further highlights some exciting examples of these MFMNPs for multimodality imaging and for target‐specific drug/gene delivery applications.
14q32/miRNA Clusters loss of heterozygosity in acute lymphoblastic leukemia is associated with up‐regulation of BCL11a
Authors: Agueli Cecilia , Cammarata Giuseppe , Salemi Domenico , Dagnino Lea , Nicoletti Roberta , La Rosa Maria , Messana Francesca , Marfia Anna , Bica Maria Grazia , Coniglio Maria Luisa , Pagano Maria , Fabbiano Francesco , Santoro Alessandra
Published: May 2010

This study evaluated the loss and expression level of miRNAs 14q32 clusters in acute lymphoblastic leukemia (ALL) patients with cryptic deletions at 14q32 chromosomal band to investigate their involvement in this disease. We demonstrate that a subset of ALL cases bearing 14q32 LOH showed a down‐regulation of miRNA 14q32 clusters, which is directly linked to the submicroscopic chromosomal deletion. As a consequence of miRNAs deregulation we reported an inverse correlation with the expression of their target BCL11a, a transcription factor involved in lymphoid differentiation. These results suggest that 14q32/miRNA clusters LOH may be another mechanism involved in lymphoid B cell transformation and differentiation and therefore, could be used as a diagnostic marker and therapeutic target in subsets of ALL. Am. J. Hematol., 2010. © 2010 Wiley‐Liss, Inc.
Common single nucleotide polymorphisms in immunoregulatory genes and multiple myeloma risk among women in Connecticut
Authors: Lee Kyoung‐Mu , Baris Dalsu , Zhang Yawei , Hosgood H. Dean , Menashe Idan , Yeager Meredith , Zahm Shelia Hoar , Wang Sophia S. , Purdue Mark P. , Chanock Stephen , Zheng Tongzhang , Rothman Nathaniel , Lan Qing
Published: May 2010

In light of the relationship between immune system dysregulation and multiple myeloma (MM) risk, we investigated whether genetic variation in 92 immune function genes among 77 gene regions are associated with MM susceptibility in a population‐based case‐control study (108 cases and 482 controls) conducted among Caucasian women in Connecticut. Tagging single‐nucleotide polymorphisms (SNPs; N = 870) were selected using a pairwise linkage‐disequilibrium based algorithm. Odds ratios (ORs) and 95% confidence intervals (CIs) for SNP genotypes were estimated using unconditional logistic regression. Tests of association for gene regions were conducted using the minP test. We applied the false discovery rate (FDR) method to the minP test results as a means of controlling for multiple comparisons. The CD4 gene region located on 12p13‐q13 (minP = 0.0009), had an FDR value <0.1. In this region, a total of six tag SNPs in two genes (CD4 and LAG3) were significantly associated with MM risk (Ptrend<0.05), with the strongest association observed for the CD4 variant rs11064392 (ORAG/GG = 2.53, 95% CI = 1.59–4.02). Our findings suggest that genetic variation in CD4 may influence susceptibility to MM. Additional studies are needed to replicate these findings and, more generally, to explore the manner in which genes and receptors may influence the pathogenesis of this poorly understood malignancy. Am. J. Hematol., 2010. © 2010 Wiley‐Liss, Inc.
Long term follow‐up of allogeneic stem cell transplantation in patients with myelodysplastic syndromes using busulfan, cytosine arabinoside, and cyclophosphamide
Authors: Atallah Ehab , Abrams Judith , Ayash Lois , Bentley Gail , Abidi Muneer , Ratanatharathorn Voravit , Uberti Joseph
Published: May 2010

We report here the 10‐year follow‐up of 86 patients who underwent allogeneic stem cell transplantation (ASCT) for myelodysplastic syndrome (MDS). All patients received the busulfan, cytosine arabinoside, and cyclophosphamide (BAC) preparative regimen which consisted of busulfan 16 mg/kg, cytosine arabinoside 8 g/m2 IV, and cyclophosphamide 120 mg/kg IV. Fifty‐nine patients (69%) had de novo MDS; 26 (30%) had secondary MDS (treatment related), and one had a preceding aplastic anemia which progressed to MDS before transplant. Cytogenetics (80 patients) was classified as good (34%), intermediate (17%), or poor (42%). With a median follow‐up for survivors of 124 months, the 10‐year Kaplan‐Meier estimates for overall survival (OS) was 43% (95% confidence interval [CI]: 31–53%). Cumulative nonrelapse mortality (NRM) and relapse was 43% (95% CI: 32–54%) and 19% (95% CI: 11–27%), respectively. No patient relapsed after 2 years. In patients with RAEB‐T/AML, 10‐year relapse‐free survival (RFS), relapse, and NRM was 36%, 36%, and 27%, respectively. Younger age (P = 0.05), human leukocyte antigen (HLA) match (P = 0.002), good risk cytogenetics (P = 0.008), and having a related donor (P = 0.03) significantly improved overall and RFS in the multivariable analysis. The long‐term follow‐up of patients receiving the BAC regimen with ASCT in this study indicated durable relapse‐free and OS with acceptable toxicity in this group of patients with high‐risk features. Am. J. Hematol., 2010. © 2010 Wiley‐Liss, Inc.
Chediak–Higashi syndrome with early developmental delay resulting from paternal heterodisomy of chromosome 1
Authors: Manoli Irini , Golas Gretchen , Westbroek Wendy , Vilboux Thierry , Markello Thomas C. , Introne Wendy , Maynard Dawn , Pederson Ben , Tsilou Ekaterini , Jordan Michael B. , Hart P. Suzanne , White James G. , Gahl William A. , Huizing Marjan
Published: May 2010

Chediak–Higashi syndrome (CHS) is a rare autosomal recessive disease characterized by variable oculocutaneous albinism, immunodeficiency, mild bleeding diathesis, and an accelerated lymphoproliferative state. Abnormal lysosome‐related organelle membrane function leads to the accumulation of large intracellular vesicles in several cell types, including granulocytes, melanocytes, and platelets. This report describes a severe case of CHS resulting from paternal heterodisomy of chromosome 1, causing homozygosity for the most distal nonsense mutation (p.E3668X, exon 50) reported to date in the LYST/CHS1 gene. The mutation is located in the WD40 region of the CHS1 protein. The patient's fibroblasts expressed no detectable CHS1. Besides manifesting the classical CHS findings, the patient exhibited hypotonia and global developmental delays, raising concerns about other effects of heterodisomy. An interstitial 747 kb duplication on 6q14.2–6q14.3 was identified in the propositus and paternal samples by comparative genomic hybridization. SNP genotyping revealed no additional whole chromosome or segmental isodisomic regions or other dosage variations near the crossover breakpoints on chromosome 1. Unmasking of a separate autosomal recessive cause of developmental delay, or an additive effect of the paternal heterodisomy, could underlie the severity of the phenotype in this patient. Published 2010 Wiley‐Liss, Inc.
Axial spondylometaphyseal dysplasia: Confirmation and further delineation of a new SMD with retinal dystrophy
Authors: Isidor Bertrand , Baron Sabine , Khau van Kien Philippe , Bertrand Anne‐Marie , David Albert , Le Merrer Martine
Published: May 2010

This report describes two unrelated boys presenting with short stature, femoral metaphyseal abnormalities, platyspondyly, and retinitis pigmentosa. Patients share similar findings with cases described by Ehara et al. [Ehara et al. (1997); Eur J Pediatr 156:627–630] described as axial spondylometaphyseal dysplasia. The presence of consanguinity in one of our patients further supports an autosomal recessive mode of inheritance of what, we believe, constitutes a separate and distinct entity. © 2010 Wiley‐Liss, Inc.
Subtelomeric deletion of 12p: Description of a third case and review
Authors: MacDonald A.H. , Rodríguez L. , Aceña I. , Martínez‐Fernández M.L. , Sánchez‐Izquierdo D. , Zuazo E. , Martínez‐Frías M.L.
Published: May 2010

Only 12 cases with a cytogenetically visible deletion of the short arm of chromosome 12 (12p) have been reported so far. The difference in clinical features observed in these patients indicates that there is no distinct phenotype associated with this short arm deletion, although the existence of a del(12p) syndrome was previously suggested. Besides those 12 reports, only two patients have been described with a subtelomeric 12p deletion; both present in the same family in which the son showed a mild phenotype of moderate mental retardation and behavioral problems and his carrier mother had no apparent phenotype. In this article, we describe the third known patient with a subtelomeric 12p deletion in a young boy with mental retardation and microcephaly, and review the literature. © 2010 Wiley‐Liss, Inc.
Array CGH in molecular diagnosis of mental retardation—A study of 150 Finnish patients
Authors: Siggberg Linda , Ala‐Mello Sirpa , Jaakkola Elisa , Kuusinen Esa , Schuit Robert , Kohlhase Jürgen , Böhm Detlef , Ignatius Jaakko , Knuutila Sakari
Published: May 2010

We report on the results of an array comparative genomic hybridization (array CGH) study of 150 karyotypically normal Finnish patients with idiopathic mental retardation and/or dysmorphic features and/or malformations. Using high‐resolution microarray analysis, we sought to identify clinically relevant microdeletions and microduplications in these patients. The results were confirmed using other methods and compared with findings reported in recent publications and internet databases. Small aberrations of potential clinical significance were found in 28 (18.6%) of the 150 patients. Eight of the identified aberrations are known to cause syndromes, 4 affected the X chromosome in males, 4 were familial, and 13 have yet to be associated with a phenotype. This study demonstrates the benefits of array CGH in clinical diagnostics of developmental disorders. Further, our findings give evidence of new syndromes. © 2010 Wiley‐Liss, Inc.
Unbalanced der(5)t(5;20) translocation associated with megalencephaly, perisylvian polymicrogyria, polydactyly and hydrocephalus
Authors: Verkerk Annemieke J.M.H. , Schot Rachel , van Waterschoot Laura , Douben Hannie , Poddighe Pino J. , Lequin Maarten H. , de Vries Linda S. , Terhal Paulien , Hahnemann Johanne M.D. , de Coo Irenaeus F.M. , de Wit Marie‐Claire Y. , Wafelman Leontien S. , Garavelli Livia , Dobyns William B. , Van der Spek Peter J. , de Klein Annelies , Mancini Grazia M.S.
Published: May 2010

The combination of megalencephaly, perisylvian polymicrogyria, polydactyly and hydrocephalus (MPPH) is a rare syndrome of unknown cause. We observed two first cousins affected by an MPPH‐like phenotype with a submicroscopic chromosome 5q35 deletion as a result of an unbalanced der(5)t(5;20)(q35.2;q13.3) translocation, including the NSD1 Sotos syndrome locus. We describe the phenotype and the deletion breakpoints of the two MPPH‐like patients and compare these with five unrelated MPPH and Sotos patients harboring a 5q35 microdeletion. Mapping of the breakpoints in the two cousins was performed by MLPA, FISH, high density SNP‐arrays and Q‐PCR for the 5q35 deletion and 20q13 duplication. The 5q35 deletion area of the two cousins almost completely overlaps with earlier described patients with an atypical Sotos microdeletion, except for the DRD1 gene. The five unrelated MPPH patients neither showed submicroscopic chromosomal aberrations nor DRD1 mutations. We reviewed the brain MRI of 10 Sotos patients and did not detect polymicrogyria in any of them. In our two cousins, the MPPH‐like phenotype is probably caused by the contribution of genes on both chromosome 5q35 and 20q13. Some patients with MPPH may harbor a submicroscopic chromosomal aberration and therefore high‐resolution array analysis should be part of the diagnostic workup. © 2010 Wiley‐Liss, Inc.
The course of cognitive‐behavioral development in children with the FMR1 mutation, Williams–Beuren syndrome, and neurofibromatosis type 1: The effect of gender
Authors: Fisch Gene S. , Carpenter Nancy , Howard‐Peebles Patricia N. , Holden Jeanette J.A. , Tarleton Jack , Simensen Richard
Published: May 2010

The course of cognitive‐behavioral development in children with intellectual disabilities produced by genetic disorders has only recently begun to be examined systematically. Unfortunately, these studies are few in number. Previously, we examined cognitive‐behavioral development in children with the fragile X (FMR1) mutation and found longitudinal decreases in both IQ and adaptive behavior (DQ) scores in most males and females with the full mutation. In this study, we examine longitudinal changes in IQ and DQ in children with neurofibromatosis type 1 (NF1) and Williams–Beuren Syndrome (WBS) by examining differences in composite IQ and DQ scores between the first test (T1) and retest (T2), and compare their developmental trajectory to children with the FMR1 mutation. Sixty‐five children with the FMR1 mutation, or NF1, or WBS, ages 4–16 years, were retested two years after initial testing with the Stanford‐Binet 4th Edition (SBFE) and the Vineland Adaptive Behavior Scale (VABS). In addition to significant longitudinal declines in IQ and DQ noted previously in children with the FMR1 mutation, we found significant decreases in IQ in males compared to females in the remainder of our sample. We also observed statistically significant decreases in DQ scores among children the FMR1 mutation, as noted previously, but not among children with NF1 or WBS. Moreover, significant declines were found only among males with the FMR1 mutation. Unlike declines in IQ scores, decreases in DQ were not significantly different between males and females. © 2010 Wiley‐Liss, Inc.
Duplication 16p11.2 in a child with infantile seizure disorder
Authors: Bedoyan Jirair K. , Kumar Ravinesh A. , Sudi Jyotsna , Silverstein Faye , Ackley Todd , Iyer Ramaswamy K. , Christian Susan L. , Martin Donna M.
Published: May 2010

Submicroscopic recurrent 16p11.2 rearrangements are associated with several neurodevelopmental disorders, including autism, mental retardation, and schizophrenia. The common 16p11.2 region includes 24 known genes, of which 22 are expressed in the developing human fetal nervous system. As yet, the mechanisms leading to neurodevelopmental abnormalities and the broader phenotypes associated with deletion or duplication of 16p11.2 have not been clarified. Here we report a child with spastic quadriparesis, refractory infantile seizures, severe global developmental delay, hypotonia, and microcephaly, and a de novo 598 kb 16p11.2 microduplication. Family history is negative for any of these features in parents and immediate family members. Sequencing analyses showed no mutations in DOC2A, QPRT, and SEZ6L2, genes within the duplicated 16p11.2 region that have been implicated in neuronal function and/or seizure related phenotypes. The child's clinical course is consistent with a rare seizure disorder called malignant migrating partial seizure disorder of infancy, raising the possibility that duplication or disruption of genes in the 16p11.2 interval may contribute to this severe disorder. © 2010 Wiley‐Liss, Inc.
Multiple malignant diseases in a patient with Rothmund–Thomson syndrome with RECQL4 mutations: Case report and literature review
Authors: Simon T. , Kohlhase J. , Wilhelm C. , Kochanek M. , De Carolis B. , Berthold F.
Published: May 2010

RECQL4 mutations cause genetic instability and increase the risk of malignant disease. We report on a patient with compound heterozygosity for two novel RECQL4 mutations: mutation c.1919_1924delTCACAG, p.L640_A642delinsP in exon 12 of the RECQL4 gene and mutation c.1704+1G>A in intron 10 of the RECQL4 gene. He subsequently developed large cell anaplastic T cell lymphoma at the age of 9 years, diffuse large cell B lymphoma and osteosarcoma when he was 14 years old, and finally acute lymphatic leukemia when he was 21 years old. The most remarkable clinical features are young age, spontaneous remission of diffuse large cell lymphoma, and severe CNS and skin toxicity of cytotoxic treatment. © 2010 Wiley‐Liss, Inc.
CDKN1C (p57Kip2) analysis in Beckwith–Wiedemann syndrome (BWS) patients: Genotype–phenotype correlations, novel mutations, and polymorphisms
Authors: Romanelli Valeria , Belinchón Alberta , Benito‐Sanz Sara , Martínez‐Glez Victor , Gracia‐Bouthelier Ricardo , Heath Karen E. , Campos‐Barros Angel , García‐Miñaur Sixto , Fernandez Luís , Meneses Heloisa , López‐Siguero Juan Pedro , Guillén‐Navarro Encarna , Gómez‐Puertas Paulino , Wesselink Jan‐Jaap , Mercado Graciela , Esteban‐Marfil Victoria , Palomo Rebeca , Mena Rocío , Sánchez Aurora , del Campo Miguel , Lapunzina Pablo
Published: May 2010

Beckwith–Wiedemann syndrome (BWS) is an overgrowth syndrome characterized by macroglossia, macrosomia, and abdominal wall defects. It is a multigenic disorder caused in most patients by alterations in growth regulatory genes. A small number of individuals with BWS (5–10%) have mutations in CDKN1C, a cyclin‐dependent kinase inhibitor of G1 cyclin complexes that functions as a negative regulator of cellular growth and proliferation. Here, we report on eight patients with BWS and CDKN1C mutations and review previous reported cases. We analyzed 72 patients (50 BWS, 17 with isolated hemihyperplasia (IH), three with omphalocele, and two with macroglossia) for CDKN1C defects with the aim to search for new mutations and to define genotype–phenotype correlations. Our findings suggest that BWS patients with CDKN1C mutations have a different pattern of clinical malformations than those with other molecular defects. Polydactyly, genital abnormalities, extra nipple, and cleft palate are more frequently observed in BWS with mutations in CDKN1C. The clinical observation of these malformations may help to decide which genetic characterization should be undertaken (i.e., CDKN1C screening), thus optimizing the laboratory evaluation for BWS. © 2010 Wiley‐Liss, Inc.
Treatment with valproic acid ameliorates ADHD symptoms in fragile X syndrome boys
Authors: Torrioli MariaGiulia , Vernacotola Silvia , Setini Chiara , Bevilacqua Francesca , Martinelli Diego , Snape Mike , Hutchison Julie A , Di Raimo Francesca Romana , Tabolacci Elisabetta , Neri Giovanni
Published: May 2010

Fragile X syndrome (FXS) is the leading cause of inherited mental retardation, due to expansion and methylation of the CGG sequence at the 5′ UTR of the FMR1 gene. Around 90% of affected boys present with attention deficit hyperactivity disorder (ADHD), while this percentage is lower in FXS girls (35–47%). Treatment of these behavioral symptoms is critical for many families. In an attempt at identifying drugs capable of restoring the activity of the FMR1 gene, we investigated the use of valproic acid (VPA), a well‐known antiepileptic drug, also used as a mood stabilizer and in migraine therapy. It is described as an inhibitor of histone deacetylase (HDAC) and, possibly, as a DNA demethylating agent. In an in vitro study we observed that treatment of lymphoblastoid cells from FXS patients with VPA caused a modest reactivation of FMR1 transcription and increased levels of histone acetylation, confirming the histone hyperacetylating effect, but not its putative DNA demethylating activity. On the basis of these findings, we decided to evaluate the in vivo efficacy of VPA on ADHD symptoms in FXS patients. We observed an improvement in the adaptive behavior, defined as the performance of daily activities required for personal and social competence, due to a significant reduction in hyperactivity after VPA treatment. This treatment could be considered as an alternative to that with stimulants, whose efficacy in patients with FXS needs to be confirmed by further studies. © 2010 Wiley‐Liss, Inc.
Upper limb kinematics and the role of the wrist during stone tool production
Authors: Williams E.M. , Gordon A.D. , Richmond B.G.
Published: May 2010

Past studies have hypothesized that aspects of hominin upper limb morphology are linked to the ability to produce stone tools. However, we lack the data on upper limb motions needed to evaluate the biomechanical context of stone tool production. This study seeks to better understand the biomechanics of stone tool‐making by investigating upper limb joint kinematics, focusing on the role of the wrist joint, during simple flake production. We test the hypotheses, based on studies of other upper limb activities (e.g., throwing), that upper limb movements will occur in a proximal‐to‐distal sequence, culminating in rapid wrist flexion just prior to strike. Data were captured from four amateur knappers during simple flake production using a VICON motion analysis system (50 Hz). Results show that subjects utilized a proximal‐to‐distal joint sequence and disassociated the shoulder joint from the elbow and wrist joints, suggesting a shared strategy employed in other contexts (e.g., throwing) to increase target accuracy. The knapping strategy included moving the wrist into peak extension (subject peak grand mean = 47.3°) at the beginning of the downswing phase, which facilitated rapid wrist flexion and accelerated the hammerstone toward the nodule. This sequence resulted in the production of significantly more mechanical work, and therefore greater strike forces, than would otherwise be produced. Together these results represent a strategy for increasing knapping efficiency in Homo sapiens and point to aspects of skeletal anatomy that might be examined to assess potential knapping ability and efficiency in fossil hominin taxa. Am J Phys Anthropol 143:134‐145, 2010. © 2010 Wiley‐Liss, Inc.
Effective reinforcement of carbon nanotubes in polypropylene matrices
Authors: Deng H. , Bilotti E. , Zhang R. , Peijs T.
Published: May 2010

This study describes an attempt to mechanically reinforce polypropylene (PP) using multi‐wall carbon nanotubes (MWNTs) through a melt compounding process followed by hot‐pressing and solid state drawing. The effect of a high density polyethylene (HDPE) coating on MWNTs and melt flow index (MFI) of PP on the dispersion of MWNTs and composite properties are studied by means of mechanical tests, transmission electron microscopy (TEM), scanning electron microscope (SEM), differential scanning calorimetry (DSC), and wide angle x‐ray diffraction (WAXD). Highly orientated composite tapes are prepared to fully utilize the properties of MWNTs in uniaxial direction. Highly aligned MWNTs are shown by SEM, while highly oriented polymer chains are characterized by WAXD. Composite theory is used to analysis the results and indicate that effective reinforcement of PP by MWNTs is highest at relatively low filler content and draw ratios. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Effect of filler loading on the mechanical properties of crosslinked 1,2,3‐triazole polymers
Authors: Katritzky Alan R. , Sakhuja Rajeev , Huang Longchuan , Gyanda Reena , Wang Ling , Jackson David Carnaby , Ciaramitaro David A. , Bedford Clifford D. , Duran Randolph S.
Published: May 2010

The effect of filler loading on the mechanical properties of crosslinked triazole polymers obtained by polymerization of E300 dipropiolate (1) with diazide (2) obtained from tetraethylene glycol using tetraacetylene functionalized crosslinker (3) was studied systematically. Aluminum (10–14 μm) was used as the primary filler during the formulations; the effect of secondary fillers such as aluminum (<75 μm), NaCl (45–50 and 83–105 μm) was studied with the increase in the total filler loading. The modulus of the aluminum‐filled crosslinked triazole polymers increases with the increase in the filler content while using either particle sized aluminum powder. The use of Al (particle size <75 μm) and NaCl (particle size 45–50 μm and 83–105 μm) as secondary or additional fillers while using aluminum (10–14 μm) as the main filler, has a diminishing effect on the modulus and strain of the crosslinked triazole polymers. Triazole polymers described herein have the ability to wet and adhere to large quantities of these inorganic salts and thus maintain mechanical properties of the composite comparable to typical polyurethane elastomeric matrices, regardless of the chemistry of the particulate filler, which imparts an important and necessary binder characteristic for energetic composites. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Preparation and characterization of polymer/multiwall carbon nanotube/nanoparticle nanocomposites and preparation of their metal complexes
Authors: Golikand Ahmad Nozad , Didehban Khadijeh
Published: May 2010

Carbon nanotube‐polymer nanocomposites were synthesized and characterized successfully. In this work, multiwall carbon nanotubes (MWCNT) were opened using HNO3/H2SO4 mixture and filled by metal nanoparticles such as silver nanoparticles through wet‐chemistry method. The oxidized MWCNT were reacted subsequently with thionyl chloride, 1,6‐diaminohexane, producing MWNT‐amine functionalized. Then the MWCNT containing metal nanoparticles were used as a monomer with different weight percentages in melt polymerization with An and CNCl separately. Furthermore, the polyamide and polytriazine modified MWCNT were used for the preparation of metal ion complexes such as Fe+2 and La+3. The structures and properties of nanocomposites were evaluated by TEM, DSC, TGA, and FT‐IR methods. The chelating behavior and sorption capacities of prepared nanocomposites were carried out by using some metal ions. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Structure and gas permeation properties of asymmetric polyimide membranes made by dry–wet phase inversion: Influence of the polyimide molecular weight
Authors: Seki Naoko , Nagaoka Shoji , Kawakami Hiroyoshi
Published: May 2010

In this article, we report the influence of the polyimide molecular weight (1.2 × 105, 2.6 × 105, and 4.1 × 105) on the structure and the gas permeation properties of asymmetric polyimide membranes made by the dry–wet phase‐inversion process. The apparent skin layer thickness of the asymmetric membrane increased with increasing molecular weight, and the thicknesses of the membranes prepared from the three polyimides with a casting polymer solution containing 8.0 wt % butanol were 132, 350, and 739 nm, respectively. That is, the gas permeance in the asymmetric membranes increased with decreasing molecular weight. In contrast, the gas selectivity of the asymmetric membranes did not depend on the skin layer thickness. The solvent evaporation in the dry phase‐inversion process and the nonsolvent diffusion in the dry process were important factors that determined the formation of the asymmetric membrane. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Studies on sorption isotherm models of ion exchange modified acrylic fibers
Authors: Zargaran Mojdeh , Shoushtari Ahmad M. , Abdouss Majid
Published: May 2010

The sorption behavior, favorability, shape and thermodynamic parameters of Cu(II), Ni(II), Pb(II), and Fe(III) ions sorption onto the ion exchage acrylic fiber were studied by applying Langmuir, Freundlich, Dubinin‐Radushkevich and Redlich–Peterson models. Analytical studies from sorption isotherms proved that sorption process follows mono layer adsorption mechanism. Gibbs free energy was spontaneous for all interactions. The adsorption processes all exhibited endothermic enthalpy values and were accompanied by increasing in entropy. The activation energies for the sorption of metal ions on aminated acrylic fiber were at the same order of magnitude as the activation energy of ion exchange. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis and characterization of poly(4‐diphenylaminostyrene)‐Poly(9‐vinylanthracene) binary block copolymer
Authors: Natori Itaru , Natori Shizue , Sekikawa Hiroyuki , Takahashi Tomoyuki , Sato Hisaya
Published: May 2010

Block copolymerization of plural types of monomers offers a new opportunity for the preparation of a variety of multifunctional polymers. Poly(4‐diphenylaminostyrene) (PDAS)‐poly(9‐vinylanthracene) (PVAN) binary block copolymer (PDAS‐PVAN) was synthesized by (living) anionic polymerization using the benzyllithium/N,N,N′,N′‐tetramethylethylenediamine system. The photoluminescence emission of PDAS‐PVAN was enhanced by the fluorescence resonance energy transfer from PDAS block to PVAN block in PDAS‐PVAN. The hole drift mobility of the copolymer was controllable by the amount of triphenylamino groups in the polymer chain. The optical and electrical properties of PDAS‐PVAN were adjustable through the polymer chain structure. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis and properties of polymer from bis‐3,4‐ethylenedioxythiophene substituted acenaphthenequinoxaline
Authors: Matsidik Rukiya , Mamtimin Xirali , Mi Hong Yu , Nurulla Ismayil
Published: May 2010

A new electrochoromic polymer poly(8,11‐bis(3,4‐ethylenedioxy thiophen‐2‐yl)acenaphtho[1,2‐b]‐quinoxaline) (PBEAQ) was synthesized by electrochemical polymerization of the corresponding monomer (BEAQ) in a 0.1 M tetraethylammonium tetrafluoroborate (TEABF4) dichloromethane–acetonitrile (2 : 1, v : v) solution. The monomer and polymer were characterized by elemental analysis, 1H‐NMR, IR, and UV‐vis spectroscopy. The electrochemical and optical properties of polymer were investigated by cyclic voltammetry and UV‐vis spectroscopy. Cyclic voltammetry and spectroelectrochemistry studies demonstrated that the polymer can be reversibly reduced and oxidized (both n‐ and p‐doped) between −2 V and +1.5 V vs. Ag/Ag+. The polymer had a transmissive light blue color in the oxidized state and reddish color in the reduced state. Undoped polymer shows UV‐vis absorption peaks at 615 nm in solution, 650 nm in solid state, and has an optical band gap of 1.5 eV. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Catalytic oxidation of organic substrates using a reusable polystyrene‐anchored orthometallated palladium(II) complex
Authors: Islam Manirul , Mondal Paramita , Roy Anupam Singha , Tuhina K.
Published: May 2010

A new heterogeneous secondary amine Pd(II) complex anchored to macroporous polystyrene beads, P‐[Pd2(seam)2(OAc)2] (seam = secondary amine), was synthesized by reacting polymer‐anchored secondary amine with palladium acetate in acetic acid medium. The structure of this immobilized complex has been established on the basis of scanning electron microscope, thermogravimetric analysis, elemental analysis, atomic absorption spectroscopy, and spectrometric methods like diffuse reflectance spectra of solid and Fourier transform infrared spectroscopy. The catalytic activity of the Pd‐complex was investigated toward the oxidation of various olefins and alcohols in presence of tert‐butylhydroperoxide as an oxidant. The effects of various parameters such as solvent, oxidant, reaction time, reaction temperature, amount of catalyst, and substrates‐to‐oxidant ratio have been studied. The catalytic results reveal that the present polymer‐anchored Pd(II) complex can be recycled more than seven times without much loss in the catalytic activity. Comparative studies have been done with the corresponding unsupported metal complex. The polymer‐anchored catalyst was found to be superior to its homogeneous counterpart in activity, product selectivity, stability, and reusability © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Study on the synthesis, structure, and properties of polydimethylsiloxane‐acrylate/organophilic montmorillonite nanocomposite emulsions
Authors: Li Hong‐Qiang , Zeng Xing‐Rong , Deng Hui‐Ping
Published: May 2010

Polydimethylsiloxane‐acrylate/organophilic montmorillonite (PDMS‐ACR/OMMT) nanocomposite emulsions were prepared by the copolymerization between ACR and PDMS/OMMT seeding emulsion, which was prepared beforehand by ring‐opening in situ polymerization of octamethyl cyclotetrasiloxane (D4) intercalated into the interlayer of OMMT modified with dodecylbenzene sulfonate acid (DBSA). OMMT, PDMS/OMMT seeding emulsion, and PDMS‐ACR/OMMT nanocomposite emulsions were characterized with X‐ray diffraction, FTIR, laser particle size analysis, SEM, and TG; the physical properties of the of PDMS‐ACR/OMMT latex films were also characterized including adherence, impact property, bend property, hardness, and water resistance. The results showed that DBSA was intercalated into the interlayer of montmorillonite, and ring‐opening in situ polymerization of D4 could be carried out favorably in OMMT interlayer. The onset weight‐loss temperature of PDMS‐ACR/OMMT latex films was higher than that of polyacrylate latex film by 44°C. When the addition of the amount of OMMT was 2 wt % in PDMS‐ACR/OMMT emulsions, OMMT had been peeled into layered structure and dispersed in the continuous polymer phase, the shape of OMMT was regular and its size was uniform, the physical properties of the latex films were improved obviously. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Preparation and characterization of elastomer‐based nanocomposite gels using an unique latex blending technique
Authors: Mitra Suman , Chattopadhyay Santanu , Bhowmick Anil K.
Published: May 2010

Nanocomposite (NC) gels based on natural rubber (NR) and styrene butadiene rubber (SBR) were prepared by using a unique latex blending technique. These NC gels were prepared by first blending the water swollen unmodified montmorillonite clay (Na+‐MMT) suspension into the respective latices followed by prevulcanization to generate crosslinked nanogels. Use of water assisted fully delaminated Na+‐MMT suspension resulted in predominantly exfoliated morphology in the NC gels, as revealed by X‐ray diffraction study and transmission electron microscopy. Addition of Na+‐MMT significantly improved various physical, mechanical and thermal properties of these NC gels. For example, 6 phr of Na+‐MMT loaded NR based NC gels registered 54% and 200% increase in tensile strength and Young's modulus, respectively, compared to the unfilled NR gels. SBR based NC gels also showed similar level of improvement in mechanical properties. Mechanical properties of NC gels prepared using this route were also compared with the NC gels prepared by co‐coagulation and conventional curing technique and found to be superior. In the case of dynamic mechanical properties, NC gels showed higher glass transition temperatures along with a concomitant increase in storage moduli, compared to the unfilled gels. These Na+‐MMT reinforced NC gels also exhibited markedly improved thermal stability. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Thermally induced solid‐state synthesis of fluorine‐containing poly(ether oxadiazole)
Authors: Maruyama Yuka , Maeda Yukihiko , Wakabayashi Kanji , Yamazaki Shinichi , Kimura Kunio
Published: May 2010

Synthesis of poly[oxy‐(2,3,5,6‐tetrafluoro‐1,4‐phenylene)‐(1,3,4‐oxadiazol‐2‐yl)‐1,4‐phenylene] (F‐PEOz) was examined by nucleophilic aromatic substitution reaction of 2‐(4‐hydroxyphenyl)‐5‐pentafluorophenyl‐1,3,4‐oxadiazole (HPOz). Only low molecular weight F‐PEOz or crosslinked insoluble polymers were obtained by the solution polymerization with bases. In contrast, thermally induced solid‐state polymerization of HPOz potassium salts at 180°C for 1 h gave fully soluble F‐PEOz with the yield of 84% and its reduced viscosity was 0.66 dL g−1. The longer polymerization time gave insoluble polymers due to the crosslinking reaction even in solid state. The solid‐state polymerization did not undergo topochemically and it proceeded in an amorphous state. The crosslinking reaction was slightly inhibited by the solid‐state polymerization. F‐PEOz exhibited excellent solubility, high Tg of 246°C and good thermal stability. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis and characterization of novel highly branched block copoly(urethane‐imide)s based on pentaerythritol, different diisocyanate and aromatic dianhydride
Authors: Chen Wenqiu , Chen Chuan , Yan Wei , Yi Changfeng , Wu Shuilin , Yeung Kelvin W. K. , Xu Zushun
Published: May 2010

In this work, we for the first time prepared a series of novel highly branched block copoly (urethane‐imide)s (CoPUIs) successfully by the condensation polymerization of star‐like prepolymers and dianhydrides, (including pyromellitic dianhydride (PMDA), 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride, and 4,4′‐oxydiphthalic anhydride) and the star‐like prepolymers were synthesized from pentaerythritol (PAT) and toluene‐2,4‐diisocyanate (TDI) or isophorone diisocyanate. Our results revealed that it took about 40 min to complete the prepolymerization of PAT and TDI at 40°C. In addition, the imidization of the prepolymer and PMDA was successfully carried out at 120°C for 2 h. The X‐ray diffractometer patterns exhibited that the resulting CoPUIs presented heterogenous structure with the d‐spacing around 0.40 nm. Differential scanning calorimeter curves showed that the Tg of these CoPUIs ranged from 214 to 229°C in N2 atmosphere. Thermogravimetric analyzer curves indicated that these synthesized CoPUIs had obviously two steps of weight loss in N2 atmosphere due to the used monomers which decomposed at 230–235°C and 602–644°C, respectively. The solubility testing results showed that the highly branched block CoPUIs had desirable solubility in several strong polar aprotic solvents and exhibited a strong resistance to dilute acid corrosion. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010