bluuebunny/crossref_metadata_2025 huggingface dataset:
Solution of Singular Integral Equations Involving Logarithmically Singular Kernel with an Application in a Water Wave Problem
Authors: Banerjea Sudeshna , Dutta Barnali , Chakrabarti A.
Published: May 2011

A direct function theoretic method is employed to solve certain weakly singular integral
equations arising in the study of scattering of surface water waves by vertical barriers
with gaps. Such integral equations possess logarithmically singular kernel, and a direct
function theoretic method is shown to produce their solutions involving singular integrals
of similar types instead of the stronger Cauchy-type singular integrals used by previous
workers. Two specific ranges of integration are examined in detail, which involve the following: Case(i) two disjoint finite intervals (0,a)∪(b,c) and (a,b,c being finite ) and Case(ii) a finite
union of n disjoint intervals. The connection of such integral equations for Case(i),
with a particular water wave scattering problem, is explained clearly, and the important quantities of practical interest (the reflection and transmission coefficients) are determined numerically by using the solution of the associated weakly singular integral equation.
Stochastic Modeling of Particle Deposition in Lungs of Cystic Fibrosis Patients
Authors: Sturm Robert
Published: May 2011

A stochastic model describing particle deposition in cystic fibrosis (CF) patients has been developed. The model should help to optimize drug administration in the treatment of CF by exploring those physiologic and physical parameters that are responsible for the delivering of pharmaceutical aerosols to appropriate sites (receptor cells). Concerning the modeling of deposition, changes of the lungs due to CF were expressed by either constant or random scaling of the airway calibers. Additionally, continuous enlargement of the alveoli and the definition of asymmetric breathing cycles (different lengths for inhalation and exhalation time) were carried out. Application of these model considerations to three different age groups (infants, children, and adults) showed that permanent reduction of the airway calibers generally increases deposition in the tracheobronchial tree by more than 100% with respect to healthy controls. The fraction of particles deposited in the alveoli and alveolar ducts may be decreased at the same time. These tendencies are even more pronounced by the simulation of emphysema and by extending exhalation time with respect to inhalation time. Relative particle fractions deposited in the tracheobronchial compartment significantly increase from infant to adult.
Acids and Acid Catalysis—Homogeneous
Authors: Molnár Árpád
Published: May 2011

The concept of acidity has changed tremendously over the years. It has developed from protic acids in the aqueous phase via Lewis acids with no proton at all to superacids. Acids are the most frequent catalysts of organic chemistry in the homogeneous phase and they find application as heterogeneous catalysts as well. In solution, they catalyze a wide variety of transformations ranging from rearrangements of various kinds through alkylations to Friedel–Crafts reactions. Intermediates are carbenium as well as carbonium ions. In many cases, they can be identified and occasionally even isolated. Many laws governing acid‐catalyzed reactions are known to such an extent that mechanistic and quantitative descriptions can be given. In the first part of this review, a general treatment of homogeneous acids and acid catalysis is given through the development of various acid–base theories and acidity scales. This is followed by a short characterization of the most important Brønsted and Lewis acids, including superacids, as well as chiral acids applied in homogeneous catalysis. In the last section, characteristic examples of important acid‐catalyzed processes of organic chemistry, including rearrangements, carbon–carbon bond formation, and breaking and forming of carbon–heteroatom bonds with emphasis on mechanistic and kinetic aspects, are discussed.
Homogeneous Catalysts and Catalysis
Authors: Crabtree Robert H.
Published: May 2011

The title topic is discussed in relation to general principles of coordination chemistry. Thermodynamics and kinetics are covered, as are the concepts of catalytic cycle, multiphase methods, rapid screening, and combinatorial chemistry as well as general mechanistic studies and types of catalyst.
Homogeneous Catalysts and Catalysis
Authors: Crabtree Robert H.
Published: May 2011

The broad features of the title topic are discussed, notably thermodynamics and kinetics, the nature of a catalytic cycle, types of catalysts and mechanistic studies.
Organometallic Catalysts and Catalysis
Authors: Crabtree Robert H.
Published: May 2011

The title topic is discussed in relation to general principles of organometallic chemistry. The 18e rule is discussed, as are the effects of coordination on ligands, the influence of mechanism on selectivity, and common organometallic reaction steps. These general points are illustrated using alkene isomerization, alkene hydrogenation, alkene hydroformylation, and the Wacker process as examples.
Delay‐dependent filtering for discrete‐time state‐delayed systems with small gain conditions in finite frequency ranges
Authors: Zhang Xiao‐Ni , Yang Guang‐Hong
Published: May 2011

This paper is concerned with the delay‐dependent filtering problem for linear discrete‐time multi‐delay systems with small gain conditions in finite frequency ranges. A new multiplier method is developed to convert the resulting nonconvex filtering synthesis conditions to the ones based on linear matrix inequalities (LMIs). Thus, sufficient conditions for the existence of feasible filters are given in terms of solutions to a set of LMIs. For the entire frequency case, it is shown that the proposed result is less conservative than the relative existing results. Finally, the procedures and the advantages of the proposed approach in comparison with the existing ones in the entire frequency range are illustrated via numerical examples. Copyright © 2011 John Wiley & Sons, Ltd.
Biomimetic Structures: Biological Implications of Dipeptide‐Substituted Polyphosphazene–Polyester Blend Nanofiber Matrices for Load‐Bearing Bone Regeneration
Authors: Deng Meng , Kumbar Sangamesh G. , Nair Lakshmi S. , Weikel Arlin L. , Allcock Harry R. , Laurencin Cato T.
Published: May 2011

Successful bone regeneration benefits from three‐dimensional (3D) bioresorbable scaffolds that mimic the hierarchical architecture and mechanical characteristics of native tissue extracellular matrix (ECM). A scaffold platform that integrates unique material chemistry with nanotopography while mimicking the 3D hierarchical bone architecture and bone mechanics is reported. A biocompatible dipeptide polyphosphazene‐polyester blend is electrospun to produce fibers in the diameter range of 50–500 nm to emulate dimensions of collagen fibrils present in the natural bone ECM. Various electrospinning and process parameters are optimized to produce blend nanofibers with good uniformity, appropriate mechanical strength, and suitable porosity. Biomimetic 3D scaffolds are created by orienting blend nanofiber matrices in a concentric manner with an open central cavity to replicate bone marrow cavity, as well as the lamellar structure of bone. This biomimicry results in scaffold stress–strain curve similar to that of native bone with a compressive modulus in the mid‐range of values for human trabecular bone. Blend nanofiber matrices support adhesion and proliferation of osteoblasts and show an elevated phenotype expression compared to polyester nanofibers. Furthermore, the 3D structure encourages osteoblast infiltration and ECM secretion, bridging the gaps of scaffold concentric walls during in vitro culture. The results also highlight the importance of in situ ECM secretion by cells in maintaining scaffold mechanical properties following scaffold degradation with time. This study for the first time demonstrates the feasibility of developing a mechanically competent nanofiber matrix via a biomimetic strategy and the advantages of polyphosphazene blends in promoting osteoblast phenotype progression for bone regeneration.
Polystyrene‐Supported Enantiopure 1,2‐Diamines: Development of a Most Practical Catalyst for the Asymmetric Transfer Hydrogenation of Ketones
Authors: Marcos Rocío , Jimeno Ciril , Pericàs Miquel A.
Published: May 2011

Chlorosulfonylated polystyrene, a commodity resin, reacts with enantiopure 1,2‐diamines to afford, in a single step, high loading catalytic resins involving monosulfonylated 1,2‐diamino moieties. These functional polymers form stable (p‐cymene)ruthenium chloride [RuCl(p‐cymene)] complexes that efficiently catalyze (down to S/C=150) the asymmetric transfer hydrogenation (ATH) of alkyl aryl ketones with formic acid‐triethylamine under essentially solvent‐free (down to 0.25 mL mmol−1) reaction conditions. Among these resins, the immobilized version of TsDPEN stands out as a most practical catalyst for ATH: Uniformly high enantioselectivities are achieved with its use at low catalyst loading, and the resin can be recycled with virtually no limits.
Chiral Squaramide‐Catalyzed Highly Enantioselective Michael Addition of 2‐Hydroxy‐1,4‐naphthoquinones to Nitroalkenes
Authors: Yang Wen , Du Da‐Ming
Published: May 2011

A chiral squaramide‐organocatalyzed, highly enantioselective Michael addition of 2‐hydroxy‐1,4‐naphthoquinones to nitroalkenes has been developed. This reaction afforded the chiral naphthoquinones in excellent yields (up to 99%) and excellent enantioselectivity (up to 98% ee) under very low catalyst loading (0.25 mol%). This organocatalytic asymmetric Michael addition provides an efficient alternative route toward the synthesis of chiral functionalized naphthoquinones.
Reversed clinical phenotype due to a microduplication of Sotos syndrome region detected by array CGH: Microcephaly, developmental delay and delayed bone age
Authors: Zhang Han , Lu Xianglan , Beasley Julie , Mulvihill John J , Liu Ruizhi , Li Shibo , Lee Ji‐Yun
Published: May 2011

Haploinsufficiency of the NSD1 gene due to 5q35 microdeletions or intragenic mutations is the major cause of Sotos syndrome characterized by generalized overgrowth, large hands and feet with advanced bone age, craniofacial dysmorphic features, learning disability, and possible susceptibility to tumors. Here, we report on a 14‐month‐old boy with a reverse phenotype of Sotos syndrome due to the reciprocal duplication of the 5q35.3 region, including the NSD1 gene, detected by array CGH. The phenotype includes delayed bone age, microcephaly, seizures, and failure to thrive. Our case suggests that the gene dosage effect of the NSD1 gene is the likely cause for the reversed phenotype of Sotos syndrome in this patient. © 2011 Wiley‐Liss, Inc.
11p14.1 microdeletions associated with ADHD, autism, developmental delay, and obesity
Authors: Shinawi Marwan , Sahoo Trilochan , Maranda Bruno , Skinner S.A. , Skinner Cindy , Chinault Craig , Zascavage Roxanne , Peters Sarika U. , Patel Ankita , Stevenson Roger E. , Beaudet Arthur L.
Published: May 2011

Genomic copy number imbalances are being increasingly identified as an important cause of intellectual disability and behavioral abnormalities. The typical deletion in WAGR syndrome encompasses the PAX6 and WT1 genes, but larger deletions have been associated with neurobehavioral abnormalities and obesity. We identified four patients with overlapping interstitial deletions on 11p14.1 and extending telomeric to the WAGR critical domain. The minimal overlapping critical chromosomal region was 2.3 Mb at 11p14.1. The deletions encompass the BDNF and LIN7C genes that are implicated in the regulation of development and differentiation of neurons and synaptic transmission. All patients with this deletion exhibit variable degrees of developmental delay, behavioral problems, and obesity. Our data show that ADHD, autism, developmental delay, and obesity are highly associated with deletion involving 11p14.1 and provide additional support for a significant role of BDNF in obesity and neurobehavioral problems. © 2011 Wiley‐Liss, Inc.
A novel mutation in PYCR1 causes an autosomal recessive cutis laxa with premature aging features in a family
Authors: Lin Dar‐Shong , Yeung Chun‐Yan , Liu Hsuan‐Liang , Ho Che‐Sheng , Shu Chyong‐Hsin , Chuang Chih‐Kuang , Huang Yu‐Wen , Wu Tsu‐Yen , Huang Zon‐Darr , Jian Yuan‐Ren , Lin Shuan‐Pei
Published: May 2011

The autosomal recessive form of type II cutis laxa (ARCL II) is characterized by the appearance of redundant, inelastic skin with wrinkling, an aged look and additional variable systemic involvement including intrauterine growth retardation, failure to thrive, developmental delay, dysmorphism, osseous abnormality, and CNS manifestations. Several genetic defects have been found in patients and families with the clinical manifestations of ARCL II. Recently, mutations in PYCR1 have been linked to cutis laxa with progeroid features. We ascertained two siblings with of ARCL II born to non‐consanguineous parents. Mutation analysis of PYCR1 revealed a novel single‐base deletion (c.345delC) in exon 4 leading to frame‐shift and premature stop of translation. The effect of this mutation results in a strong reduction of PYCR1 expression in skin fibroblasts from affected siblings. These two cases extend the genotypic spectrum of PYCR1‐related ARCL II. © 2011 Wiley‐Liss, Inc.
Lethal presentation of neurofibromatosis and Noonan syndrome
Authors: Prada Carlos E. , Zarate Yuri A. , Hagenbuch Sean , Lovell Anne , Schorry Elizabeth K. , Hopkin Robert J.
Published: May 2011

Neurofibromatosis type 1 and Noonan syndrome are both common genetic disorders with autosomal dominant inheritance. Similarities between neurofibromatosis type 1 and Noonan syndrome have been noted for over 20 years and patients who share symptoms of both conditions are often given the diagnosis of neurofibromatosis–Noonan syndrome (NFNS). The molecular basis of these combined phenotypes was poorly understood and controversially discussed over several decades until the discovery that the syndromes are related through disturbances of the Ras pathway. We present an infant male with coarse facial features, severe supravalvar pulmonic stenosis, automated atrial tachycardia, hypertrophic cardiomyopathy, airway compression, severe neurological involvement, and multiple complications that lead to death during early infancy. The severity of clinical presentation and significant dysmorphic features suggested the possibility of a double genetic disorder in the Ras pathway instead of NFNS. Molecular analysis showed a missense mutation in exon 25 of the NF1 gene (4288A>G, p.N1430D) and a pathogenic mutation on exon 8 (922A>G, p.N308D) of the PTPN11 gene. Cardiovascular disease has been well described in patients with Noonan syndrome with PTPN11 mutations but the role of haploinsufficiency for neurofibromin in the heart development and function is not yet well understood. Our case suggests that a double genetic defect resulting in the hypersignaling of the Ras pathway may lead to complex cardiovascular abnormalities, cardiomyopathy, refractory arrhythmia, severe neurological phenotype, and early death. © 2011 Wiley‐Liss, Inc.
Mutation in SAM domain of TP63 is associated with nonsyndromic cleft lip and palate and cleft palate
Authors: Kantaputra Piranit N. , Malaivijitnond Sutti , Vieira Alexandre R. , Heering Jan , Dötsch Volker , Khankasikum Theerapong , Sripathomsawat Warissara
Published: May 2011

Mutations in sterile alpha motif (SAM) domain of TP63 have been reported to be associated with ankyloblepharon‐ectodermal dysplasia‐cleft lip/palate syndrome and Rapp‐Hodgkin syndrome. SAM domain, a protein–protein interaction module, is found in cytoplasmic signaling proteins and several transcriptional regulatory proteins which are involved in development and differentiation. Here, we report on a SAM domain mutation (p.Asp564His) in TP63 that predisposed the patients to have nonsyndromic cleft palate and nonsyndromic cleft lip and palate. © 2011 Wiley‐Liss, Inc.
High prevalence of carpal tunnel syndrome in children with mucopolysaccharidosis type II (Hunter syndrome)
Authors: Kwon Jeong‐Yi , Ko Kiljun , Sohn Young Bae , Kim Su Jin , Park Sung Won , Kim Se‐Hwa , Cho Sung‐Yoon , Jin Dong‐Kyu
Published: May 2011

Although carpal tunnel syndrome (CTS) is the most common compressive neuropathy seen in the upper extremity of adults, it is rarely seen in children. Several reports have shown that mucopolysaccharidosis type II (Hunter syndrome), a rare genetic disorder, is one of the causes of CTS in children. Usual symptoms of CTS are pain, weakness, and paresthesias in the hand and digits. However, the diagnosis of CTS in Hunter syndrome is often delayed or unrecognized because of atypical symptoms and cognitive impairment. Here, we report the prevalence, clinical manifestation, and nerve conduction profiles of CTS in 45 Hunter syndrome patients. The mean age of the study participants was 117.1 (74.9) months (range: 4–408 months); all patients were male. Forty‐three (96.0%) of the 45 patients with Hunter syndrome had CTS. Bilateral CTS was observed in all patients; 73 (82.0%) of the patients' hands had severe degree of CTS. Intriguingly, in contrast with other nerve velocities, decreases in forearm conduction velocities of the median nerve were observed in 28 (31.5%) of 89 hands with CTS. There was a significant difference in age (P < 0.001) between hands with normal, mild, moderate, and severe grades of CTS. The compound muscle action potential and sensory nerve action potential amplitudes of the median nerves decreased with age (CMAP, r = −0.526, P < 0.001; SNAP, r = −0.564, P < 0.001). Early recognition and intervention to ameliorate the symptoms of CTS are important in improving the quality of life of Hunter syndrome patients. © 2011 Wiley‐Liss, Inc.
Significance of marrow‐derived nicotinamide adenine dinucleotide phosphate oxidase in experimental ischemic stroke
Authors: Tang Xian N. , Zheng Zhen , Giffard Rona G. , Yenari Midori A.
Published: May 2011

Objective:

Reperfusion after stroke leads to infiltration of inflammatory cells into the ischemic brain. Nicotinamide adenine dinucleotide phosphate oxidase (NOX2) is a major enzyme system that generates superoxide in immune cells. We studied the effect of NOX2 derived from the immune cells in the brain and in blood cells in experimental stroke.

Methods:

To establish whether NOX2 plays a role in brain ischemia, strokes were created in mice, then mice were treated with the NOX2 inhibitor apocynin or vehicle and compared to mice deficient in NOX2's gp91 subunit and their wild‐type littermates. To determine whether NOX2 in circulating cells versus brain resident cells contribute to ischemic injury, bone marrow chimeras were generated by transplanting bone marrow from wild‐type or NOX2‐deficient mice into NOX2 or wild‐type hosts, respectively.

Results:

Apocynin and NOX2 deletion both significantly reduced infarct size, blood–brain barrier disruption, and hemorrhagic transformation of the infarcts, compared to untreated wild‐type controls. This was associated with decreased matrix metalloproteinase 9 expression and reduced loss of tight junction proteins. NOX2‐deficient mice receiving wild‐type marrow had better outcomes compared to the wild‐type mice receiving wild‐type marrow. Interestingly, wild‐type mice receiving NOX2‐deficient marrow had even smaller infarct sizes and less hemorrhage than NOX2‐deficient mice receiving wild‐type marrow.

Interpretation:

This indicates that NOX2, whether present in circulating cells or brain resident cells, contributes to ischemic brain injury and hemorrhage. However, NOX2 from the circulating cells contributed more to the exacerbation of stroke than that from brain resident cells. These data suggest the importance of targeting the peripheral immune system for treatment of stroke. Ann Neurol 2011;70:606–615
A randomized, pilot trial of etanercept in dermatomyositis
Authors:   The Muscle Study Group
Published: May 2011

Objective:

The aims of this pilot study were to assess (1) the safety and tolerability of etanercept in dermatomyositis (DM); (2) the feasibility and safety of a forced prednisone taper; and (3) outcome measures, including those recommended by the International Myositis Assessment Clinical Study (IMACS) group.

Methods:

We conducted a randomized, double‐blind, placebo‐controlled trial of etanercept (50mg subcutaneously weekly) for 52 weeks in DM subjects. Subjects were tapered off prednisone in a standardized schedule as tolerated over the initial 24 weeks of the study. Principal outcomes included adverse events, time from randomization to treatment failure (inability to wean off prednisone on schedule), and average prednisone dosage after week 24.

Results:

Sixteen subjects were randomized, 11 to etanercept and 5 to placebo. There were no significant differences in adverse event rates between the treatment groups, although 5 etanercept‐treated and 1 placebo‐treated subjects developed worsening rash. All 5 subjects receiving placebo were treatment failures (median time to treatment failure 148 days). In contrast, 5 of 11 subjects in the etanercept arm were successfully weaned off prednisone; the median time to treatment failure in this group was 358 days (p = 0.0002). The median of the average prednisone dosage after week 24 was 29.2mg/day in the placebo group and 1.2mg/day in the etanercept group (p = 0.02). IMACS and other outcome measures demonstrated excellent test–retest reliability (intraclass correlation coefficients 0.79–0.99). There was no significant treatment effect on functional outcome.

Interpretation:

The findings of no major safety concerns and a steroid‐sparing effect in our study suggest that further investigation of etanercept as a treatment for DM is warranted. Ann Neurol 2011;
Neuron‐restrictive silencer factor‐mediated hyperpolarization‐activated cyclic nucleotide gated channelopathy in experimental temporal lobe epilepsy
Authors: McClelland Shawn , Flynn Corey , Dubé Celine , Richichi Cristina , Zha Qinqin , Ghestem Antoine , Esclapez Monique , Bernard Christophe , Baram Tallie Z.
Published: May 2011

Objective:

Enduring, abnormal expression and function of the ion channel hyperpolarization‐activated cyclic adenosine monophosphate gated channel type 1 (HCN1) occurs in temporal lobe epilepsy (TLE). We examined the underlying mechanisms, and investigated whether interfering with these mechanisms could modify disease course.

Methods:

Experimental TLE was provoked by kainic acid‐induced status epilepticus (SE). HCN1 channel repression was examined at mRNA, protein, and functional levels. Chromatin immunoprecipitation was employed to identify the transcriptional mechanism of repressed HCN1 expression, and the basis for their endurance. Physical interaction of the repressor, NRSF, was abolished using decoy oligodeoxynucleotides (ODNs). Video/electroencephalographic recordings were performed to assess the onset and initial pattern of spontaneous seizures.

Results:

Levels of NRSF and its physical binding to the Hcn1 gene were augmented after SE, resulting in repression of HCN1 expression and HCN1‐mediated currents (Ih), and reduced Ih‐dependent resonance in hippocampal CA1 pyramidal cell dendrites. Chromatin changes typical of enduring, epigenetic gene repression were apparent at the Hcn1 gene within a week after SE. Administration of decoy ODNs comprising the NRSF DNA‐binding sequence (neuron restrictive silencer element [NRSE]), in vitro and in vivo, reduced NRSF binding to Hcn1, prevented its repression, and restored Ih function. In vivo, decoy NRSE ODN treatment restored theta rhythm and altered the initial pattern of spontaneous seizures.

Interpretation:

Acquired HCN1 channelopathy derives from NRSF‐mediated transcriptional repression that endures via chromatin modification and may provide insight into the mechanisms of a number of channelopathies that coexist with, and may contribute to, the conversion of a normal brain into an epileptic one. ANN NEUROL 2011;70: 454–464.
The thermal‐electrical properties of polyvinyl alcohol/AgNO3 films
Authors: Liang Sen , Yang Jianfeng , Zhang Xiao , Bai Yu
Published: May 2011

In this article, one cast technique to fabricate 20–40 wt %AgNO3‐doped polyvinyl alcohol (PVA) composite films of which electrical resistance sharply dropped (4–5 order) in a certain temperature range was reported. The phase, structure thermal, and electrical resistivity properties of films at different heat treatment temperatures were studied by X‐ray diffraction (XRD), scanning electrical microscopy (SEM) and differential scanning calorimetry (DSC). The results showed that all the AgNO3 (20–40 wt %) doped PVA films presented an exothermic peak at 182°C. And the temperature of exothermic peak kept constant for various contents of AgNO3. Meanwhile, the phase composition of the films was greatly affected by the heat treatment temperature. Ag particles were generated during the heat treatment process, and the content of Ag particles increased with increasing the temperature. The resistivity of PVA/AgNO3 films decreased with increasing the temperature. And a sharp decrease appeared at 155–165°C due to the generation and contact of a mass of Ag particles at this temperature. The thermal‐electrical results suggested the applicability of these materials in temperature sensor, for example, critical temperature resistor thermistor. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
BA‐MMA‐POMA copolymer latexes prepared by using HMPS polymerizable emulsifier
Authors: Chen Lijun , Wu Fengqin
Published: May 2011

BA‐MMA‐POMA copolymer latex was successfully prepared by soap‐free emulsion polymerization of 2‐(perfluoro‐(1,1‐bisisopropyl)‐2‐propenyl)oxyethyl methacrylate(POMA) with butyl acrylate(BA), methyl methacrylate (MMA) initiated by K2S2O8 in the water. POMA was synthesized from the intermediate perfluoro nonene and 2‐hydroxyethyl methacrylate as the staring reactants. The structure of BA‐MMA‐POMA copolymer latex was investigated by Fourier transform infrared (FTIR). The characteristics of the film such as hydrophobicity and glass transition temperature were characterized with the contact angle and differential scanning calorimetry respectively. The influences of the amount of the fluorinated monomer and the initiator on the soap‐free emulsion polymerization and performance of the latex were studied. In addition, comparison with the latex prepared by the conventional emulsifier SDBS is investigated. Results show that the hydrophobicity and glass transition temperature (Tg) of the latex are increased when the fluorinated monomer is introduced to copolymerize with other monomers. The hydrophobicity can be improved further with heating. Compared with the latices prepared by using SDBS emulsifier, the latices prepared by using HMPS emulsifier have larger particle size, higher surface tension. However, the difference of their Tg is extremely minute. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Influence of ammonium polyphosphate modified with 3‐(methylacryloxyl) propyltrimethoxy silane on mechanical and thermal properties of wood flour–polypropylene composites
Authors: Zhou Lin , Guo Chuigen , Li Liping
Published: May 2011

In this article, the influence of ammonium polyphosphate (APP) and ammonium polyphosphate modified with 3‐(Methylacryloxyl) propyltrimethoxy silane (M‐APP) on mechanical properties, flame retardancy, and thermal degradation of wood flour–polypropylene composites (WF/PP composites) have been investigated. Polypropylene grafted with m‐isopropenyl‐α,α‐dimethylbenzyl‐isocyanate (m‐TMI‐g‐PP) was used to improve the adhesion of WF/PP composites. APP and M‐APP were used as flame retardants. The experimental results demonstrated that addition of M‐APP obviously enhanced mechanical properties of WF/PP composites. According to cone calorimetry results, M‐APP is also an effective flame retardant for WF/PP composites, compared to that of APP. It was also found that M‐APP decreased the 1% weight loss temperature and increased char residue. The thermal degradation of wood flour based upon the first peak temperature of wood decreased from 329.3 to 322.9°C and the thermal degradation of PP based upon the second peak temperature of PP improve from 518.0 to 519.6°C, when M‐APP was added to the WF/PP composites. From SEM results the char layer of the 25% M‐APP systems is much more intumescent than that of the 25% APP systems, indicating that 3‐(Methylacryloxyl) propyltrimethoxy silane can improve the char‐forming ability of WF/PP composites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Concept of minimum electrospinning voltage in electrospinning of polyacrylonitrile N,N‐dimethylformamide system
Authors: Basu Sandip , Agrawal Ashwini K. , Jassal Manjeet
Published: May 2011

Polyacrylonitrile solutions in N,N‐dimethylformamide (DMF) were electrospun into nanofibers by charging the polymer fluid in an electric field. Controlled experiments were performed using a needle type spinneret to investigate the effect of various electrospinning parameters on the percentage conversion of polymeric fluid into fibers and on fiber diameter obtained. It was found that when the polymeric fluid was continuously fed at a constant rate, application of a minimum electrospinning voltage (MEV) was necessary to “completely” convert the ejected fluid into nanojets to form nanofibers. Also, that the maximum amount of splitting or elongation that a polymeric fluid could undergo was primarily dependent on number of entanglements per chain in the fluid. This resulted in obtaining nanofibers with a particular diameter irrespective of the values of important electrospinning variables such as applied voltage, flow rates, and distance between the electrodes. On the other hand, MEV, necessary to obtain full conversion into nanofibers, was found to be strongly dependent on the spinning parameters and was unique for a given set of parameters. The significance of the MEV was evident from the fact that the square of the MEV, which is a measure of the electrical energy utilized by the system, was found to be directly proportional to the rate of formation of fiber surface area during the electrospinning process. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Bridging autism, science and society: moving toward an ethically informed approach to autism research
Authors: Pellicano Elizabeth , Stears Marc
Published: May 2011

Recent developments in the science of autism have provoked widespread unease among autism activists. Drawing on the findings of a major international gathering of researchers, ethicists, and activists, this paper presents the first major analysis of the ethical questions arising from this unease. We outline the scientific developments that have provoked the most discomfort, analyze the response to these developments from within and without the autism community, and trace the current state of the ethical debate. Having done so, we contend that these ethical questions are unlikely to be resolved as they depend on fundamentally conflicting assumptions about the nature and desirability of neurocognitive difference. We conclude by arguing for a new range of democratic mechanisms that could enable the scientific community, autistics, and other concerned parties to respond collectively to such entrenched ethical disputes. Autism Res 2011,4:271–282. © 2011 International Society for Autism Research, Wiley Periodicals, Inc.
Impacts of co‐location, co‐production, and process energy source on life cycle energy use and greenhouse gas emissions of lignocellulosic ethanol
Authors: McKechnie Jon , Zhang Yimin , Ogino Akifumi , Saville Brad , Sleep Sylvia , Turner Mark , Pontius Robert , MacLean Heather L.
Published: May 2011

The performance of lignocellulosic ethanol in reducing greenhouse gas (GHG) emissions and fossil energy use when substituting for gasoline depends on production technologies and system decisions, many of which have not been considered in life cycle studies. We investigate ethanol production from short rotation forestry feedstock via an uncatalyzed steam explosion pre‐treatment and enzymatic hydrolysis process developed by Mascoma Canada, Inc., and examine a set of production system decisions (co‐location, co‐production, and process energy options) in terms of their influence on life cycle emissions and energy consumption. All production options are found to reduce emissions and petroleum use relative to gasoline on a well‐to‐wheel (WTW) basis; GHG reductions vary by production scenario. Land‐use‐change effects are not included due to a lack of applicable data on short rotation forestry feedstock. Ethanol production with wood pellet co‐product, displacing coal in electricity generation, performs best amongst co‐products in terms of GHG mitigation (−109% relative to gasoline, WTW basis). Maximizing pellet output, although requiring import of predominately fossil‐based process energy, improves overall GHG‐mitigation performance (−130% relative to gasoline, WTW). Similarly, lower ethanol yields result in greater GHG reductions because of increased co‐product output. Co‐locating ethanol production with facilities exporting excess steam and biomass‐based electricity (e.g. pulp mills) achieves the greatest GHG mitigation (−174% relative to gasoline, WTW) by maximizing pellet output and utilizing low‐GHG process energy. By exploiting co‐location opportunities and strategically selecting co‐products, lignocellulosic ethanol can provide large emission reductions, particularly if based upon sustainably grown, high yield, low input feedstocks. © 2011 Society of Chemical Industry and John Wiley & Sons, Ltd
Codon usage: Nature's roadmap to expression and folding of proteins
Authors: Angov Evelina
Published: May 2011

Biomedical and biotechnological research relies on processes leading to the successful expression and production of key biological products. High‐quality proteins are required for many purposes, including protein structural and functional studies. Protein expression is the culmination of multistep processes involving regulation at the level of transcription, mRNA turnover, protein translation, and post‐translational modifications leading to the formation of a stable product. Although significant strides have been achieved over the past decade, advances toward integrating genomic and proteomic information are essential, and until such time, many target genes and their products may not be fully realized. Thus, the focus of this review is to provide some experimental support and a brief overview of how codon usage bias has evolved relative to regulating gene expression levels.
Transradial cardiac catheterization: A Review of Access Site Complications
Authors: Kanei Yumiko , Kwan Tak , Nakra Navin C. , Liou Michael , Huang Yili , Vales Lori L. , Fox John T. , Chen Jack P. , Saito Shigeru
Published: May 2011

Transradial catheterization (TRC) has been associated with a lower incidence of major access site related complications as compared to the transfemoral approach. With the increased adoption of transradial access, it is essential to understand the potential major and minor complications of TRC. The most common complication is asymptomatic radial artery occlusion, which rarely leads to clinical events, owing to the dual collateral perfusion of the hand. Adequate anticoagulation, appropriate compression techniques, and smaller sheath size can minimize the risk of radial artery occlusion. Hand ischemia with necrosis has never been reported during TRC with thorough pre‐examination of intact collateral circulation. Radial artery spasm is relatively common, and can result in access and procedural failure. It can be prevented by the use of vasodilator cocktails and hydrophilic sheaths. Radial artery perforation can lead to severe forearm hematoma and compartment syndrome if not managed promptly. Careful observation, prompt detection of the hematoma, and management with a pressure bandage dressing are critical to avoid serious complications. Pseudoaneurym and arteriovenous fistula are rare complications, which can likely be managed conservatively without surgical intervention. Nerve injury occurring during access has been reported. Close observation for improvement is necessary, although symptoms usually improve over time. In summary, to prevent access site complications, avoidance of multiple punctures, gentle catheter manipulation, use of guided compression, coupled with careful observation for adverse warning signs such as hematoma, loss of pulse, pain, are critical for safe and effective TRC. © 2011 Wiley Periodicals, Inc.
Adderall induced inverted‐Takotsubo cardiomyopathy
Authors: Alsidawi Said , Muth James , Wilkin James
Published: May 2011

Introduction: Takotsubo Cardiomyopathy (TTC), also known as stress‐induced cardiomyopathy, was initially described in Japan in 1990. Both illicit and prescription drugs have added to the growing list of insulting stressors. We describe an interesting case of atypical TTC triggered by adderall overdose. Clinical case: A 19‐year‐old female was brought to the Emergency Department after ingesting 30 Adderall tablets. She was complaining of pressure like chest pain and shortness of breath. Her cardiac enzymes were elevated but the electrocardiogram was unremarkable. Echocardiography identified an ejection fraction (EF) of 25–30% with severe hypokinesis of the base and a preserved apex. Cardiac angiography demonstrated normal coronary arteries with an EF of 35%, hyperkinetic apex and akinetic base consistent with the diagnosis of inverted‐TTC. Her symptoms resolved in 24 hrs. Repeat echocardiogram performed 3 days later showed an EF of 60% with no regional wall motion abnormalities. Discussion: TTC can be identified as a rapid development of severe and reversible left ventricular dysfunction extending beyond the territory of a single epicardial coronary artery in the absence of coronary artery disease or pheochromocytoma. Clinical presentation can be challenging and very hard to distinguish from acute myocardial infarction. Medication induced‐TTC has been reported. In our case, the patient overdosed on Adderall which is a sympathomimetic medication. Cardiac imaging identified wall motion abnormalities consistent with inverted type TTC. Restoration of left ventricular function within days confirms the diagnosis of TTC. In conclusion, this case offers an interesting insight into the pathophysiology of TTC. © 2011 Wiley Periodicals, Inc.
Long‐term outcome after drug‐eluting stent implantation in unselected population: ROME and UDINE Experience (The RUDI Registry)
Authors: Sardella Gennaro , Conti Giulia , Bisceglia Teodoro , Canali Emanuele , Mancone Massimo , De Carlo Carlotta , Spedicato Leonardo , Morocutti Giorgio , Fedele Francesco , Bernardi Guglielmo
Published: May 2011

Objectives: The aim of our study is to evaluate the safety and efficacy of DES implantation in an unselected, “real world,” high‐risk population. Background: Several clinical trials showed that drug‐eluting stents (DESs) implantation is safe and effective in selected population. In spite of these encouraging results, there are some concerns about “real world” utilization of these stents. Methods: One thousand four hundred and fifty‐five off‐label patients have been included in our registry. Primary end‐points were: long‐term clinical incidence of major adverse cardiac and cerebrovascular events (MACCE) and thrombosis (ST). We detected the difference between uniDES vs. multiDES implantation in terms of MACCE, death, nonfatal‐MI, the composite of death/nonfatal‐MI and target lesion revascularization (TLR) and the difference between DES type in term of MACCE. Results: At 36 months follow‐up we found: cardiac death occurred in 20 patients (1.6%); 33 patients (2.6%) had a nonfatal MI and 81 patients (6.3%) had a TLR. We observed one (0.1%) acute, 9 subacute (0.6%), 6 late (0.6%), and 1 (0.5%) very late definite ST. No difference were found in terms of overall MACCE, MI, death and composite of death/nonfatal‐MI between uni‐ and multiDES implantation but multiDES group had a higher incidence of TLR. No difference between DES type in term of MACCE was detected. Conclusions: DES utilization shows their safety and efficacy in off‐label patients with complex clinical and angiographic profile in terms of long‐term incidence of MACCE. MultiDES implantation is associated with a higher risk of long‐term TLR. No difference between DES type was found. © 2011 Wiley Periodicals, Inc.
Application of radiofrequency perforation to recanalization late stent thrombosis of aortic coarctation
Authors: Aguirre‐Molina Carlos Alberto , García‐Montes José Antonio , Bialkowski Jacek
Published: May 2011

We present an interesting complication of late stent thrombosis after percutaneous treatment of aortic coartaction and a new modality of treatment with radiofrequency perforation and implantation of additional stent to resolve this problem. © 2011 Wiley‐Liss, Inc.
Anthraquinone Monosulfonate Adsorbed on Graphite Shows Two Very Different Rates of Electron Transfer: Surface Heterogeneity Due to Basal and Edge Plane Sites
Authors: Neumann Christopher C. M. , Batchelor‐McAuley Christopher , Downing Clive , Compton Richard G.
Published: May 2011

Graphitic electrodes find widespread use throughout electrochemistry; understanding their fundamental electrochemical properties is imperative. It is widely thought that graphite edge plane sites exhibit faster rates of electron transfer as compared to basal plane sites. Hitherto the different rates of electron transfer at the edge and basal sites have been inferred indirectly using diffusional systems. To avoid possible complications we alternatively study a surface‐bound system to simplify the interpretation. The voltammetric response of graphitic‐surface‐bound anthraquinone monosulfonate (AQMS) with varying pH, reveals two distinct voltammetric responses, ascribed as being due to the basal and edge plane sites; where the pKa s associated with the reduced anthraquinone are found to differ for the two sites. Through modelling of the system based upon a “scheme of squares” mechanism it is possible to conclude that both the thermodynamics and kinetics of the species differ in the two environments in which the rate of electron transfer at the basal plane site is shown to be 2–3 orders of magnitude slower than that of the edge plane site. This work provides the first example of a voltammetric response which is purely due to electron transfer at a basal plane site. Further, we believe this is the first time a full “scheme of squares” model has been used for the quantitative analysis of a diffusionless 2H+2e− system.
Ultrasensitive Electrochemical Analysis of Two Analytes by Using an Autonomous DNA Machine that Works in a Two‐Cycle Mode
Authors: Zhang Hui , Fang Congcong , Zhang Shusheng
Published: May 2011

We report a novel autonomous DNA machine for amplified electrochemical analysis of two DNAs. The DNA machine operates in a two‐cycle working mode to amplify DNA recognition events; the working mode is assisted by two different nicking endonucleases (NEases). Two bio‐barcode probes, a ZnS nanoparticle (NP)–DNA probe and a CdS NP–DNA probe, were used to trace two target DNAs. The detection system was based on a sensitive differential pulse anodic stripping voltammetry (DPASV) method for the simultaneous detection of ZnII and CdII tracers, which were obtained by dissolving the two probes. Under the optimised conditions, detection limits as low as 5.6×10−17 (3σ) and 4.1×10−17 M (3σ) for the two target DNAs were achieved. It has been proven that the DNA machine system can simultaneously amplify two target DNAs by more than four orders of magnitude within 30 min at room temperature. In addition, in combination with an aptamer recognition strategy, the DNA machine was further used in the aptamer‐based amplification analysis of adenosine triphosphate (ATP) and lysozyme. With the amplification of the DNA machine, detection limits as low as 5.6×10−9 M (3σ) for ATP and 5.2×10−13 M (3σ) for lysozyme were simultaneously obtained. The satisfactory determination of ATP and lysozyme in Ramos cells reveals the good selectivity and feasibility of this protocol. The DNA machine is a promising tool for ultrasensitive and simultaneous multianalysis because of its remarkable signal amplification and simple machine‐like operation.
Targeting Norovirus Infection—Multivalent Entry Inhibitor Design Based on NMR Experiments
Authors: Rademacher Christoph , Guiard Julie , Kitov Pavel I. , Fiege Brigitte , Dalton Kevin P. , Parra Francisco , Bundle David R. , Peters Thomas
Published: May 2011

Noroviruses attach to their host cells through histo blood group antigens (HBGAs), and compounds that interfere with this interaction are likely to be of therapeutic or diagnostic interest. It is shown that NMR binding studies can simultaneously identify and differentiate the site for binding HBGA ligands and complementary ligands from a large compound library, thereby facilitating the design of potent heterobifunctional ligands. Saturation transfer difference (STD) NMR experiments, spin‐lock filtered NMR experiments, and interligand NOE (ILOE) experiments in the presence of virus‐like particles (VLPs), identified compounds that bind to the HBGA binding site of human norovirus. Based on these data two multivalent prototype entry‐inhibitors against norovirus infection were synthesized. A surface plasmon resonance based inhibition assay showed avidity gains of 1000 and one million fold over a millimolar univalent ligand. This suggests that further rational design of multivalent inhibitors based on our strategy will identify potent entry‐inhibitors against norovirus infections.
Induction of Molecular Chirality by Circularly Polarized Light in Cyclic Azobenzene with a Photoswitchable Benzene Rotor
Authors: Hashim P. K. , Thomas Reji , Tamaoki Nobuyuki
Published: May 2011

New phototriggered molecular machines based on cyclic azobenzene were synthesized in which a 2,5‐dimethoxy, 2,5‐dimethyl, 2,5‐difluorine or unsubstituted‐1,4‐dioxybenzene rotating unit and a photoisomerizable 3,3′‐dioxyazobenzene moiety are bridged together by fixed bismethylene spacers. Depending upon substitution on the benzene moiety and on the E/Z conformation of the azobenzene unit, these molecules suffer various degrees of restriction on the free rotation of the benzene rotor. The rotation of the substituted benzene rotor within the cyclic azobenzene cavity imparts planar chirality to the molecules. Cyclic azobenzene 1, with methoxy groups at both the 2‐ and 5‐positions of the benzene rotor, was so conformationally restricted that free rotation of the rotor was prevented in both the E and Z isomers and the respective planar chiral enantiomers were resolved. In contrast, compound 2, with 2,5‐dimethylbenzene as the rotor, demonstrated the property of a light‐controlled molecular brake, whereby rotation of the 2,5‐dimethylbenzene moiety is completely stopped in the E isomer (brake ON, rotation OFF), while the rotation is allowed in the Z isomer (brake OFF, rotation ON). The cyclic azobenzene 3, with fluorine substitution on the benzene rotor, was in the brake OFF state regardless of E/Z photoisomerization of the azobenzene moiety. More interestingly, for the first time, we demonstrated the induction of molecular chirality in a simple monocyclic azobenzene by circular‐polarized light. The key characteristics of cyclic azobenzene 2, that is, stability of the chiral structure in the E isomer, fast racemization in the Z isomer, and the circular dichroism of enantiomers of both E and Z isomers, resulted in a simple reversible enantio‐differentiating photoisomerization directly between the E enantiomers. Upon exposure to r‐ or l‐circularly polarized light at 488 nm, partial enrichment of the (S)‐ or (R)‐enantiomers of 2 was observed.