bluuebunny/crossref_metadata_2025 huggingface dataset:
Differential connectivity of short‐ vs. long‐range extrinsic and intrinsic cortical inputs to perirhinal neurons
Authors: Unal Gunes , Pare Jean‐Francois , Smith Yoland , Pare Denis
Published: January 2013

The perirhinal cortex plays a critical role in recognition and associative memory. However, the network properties that support perirhinal contributions to memory are unclear. To shed light on this question, we compared the synaptic articulation of short‐ and long‐range inputs from the perirhinal cortex or temporal neocortex with perirhinal neurons in rats. Iontophoretic injections of the anterograde tracer Phaseolus vulgaris‐leucoagglutinin (PHAL) were performed at different rostrocaudal levels of the ventral temporal neocortex or perirhinal cortex, and electron microscopic observations of anterogradely labeled (PHAL+) axon terminals found at perirhinal sites adjacent to or rostrocaudally distant from the injection sites were performed. After neocortical injections, the density of PHAL+ axons in the perirhinal cortex decreased steeply with rostrocaudal distance from the injection sites, much more so than following perirhinal injections. Otherwise, similar results were obtained with neocortical and perirhinal injections. In both cases, most (76–86%) PHAL+ axon terminals formed asymmetric synapses, typically with spines (type A, 83–89%) and less frequently with dendritic profiles (type B, 11–17%). The remaining terminals formed symmetric synapses with dendritic profiles (type C, 14–23%). Type B and C synapses were 2.4–2.6 times more frequent in short‐ than long‐range connections. The postsynaptic elements in type A–C synapses were identified with immunocytochemistry for CAMKIIα, a marker of glutamatergic cortical neurons. Type A and C terminals contacted CAMKIIα‐positive principal cells, whereas type B synapses contacted presumed inhibitory neurons. Overall, these results suggest that principal perirhinal neurons are subjected to significantly more inhibition from short‐ than from long‐range cortical inputs, an organization that likely impacts perirhinal contributions to memory. J. Comp. Neurol. 521:2538–2550, 2013. © 2013 Wiley Periodicals, Inc.
Cell death atlas of the postnatal mouse ventral forebrain and hypothalamus: Effects of age and sex
Authors: Ahern Todd H. , Krug Stefanie , Carr Audrey V. , Murray Elaine K. , Fitzpatrick Emmett , Bengston Lynn , McCutcheon Jill , De Vries Geert J. , Forger Nancy G.
Published: January 2013

Naturally occurring cell death is essential to the development of the mammalian nervous system. Although the importance of developmental cell death has been appreciated for decades, there is no comprehensive account of cell death across brain areas in the mouse. Moreover, several regional sex differences in cell death have been described for the ventral forebrain and hypothalamus, but it is not known how widespread the phenomenon is. We used immunohistochemical detection of activated caspase‐3 to identify dying cells in the brains of male and female mice from postnatal day (P) 1 to P11. Cell death density, total number of dying cells, and regional volume were determined in 16 regions of the hypothalamus and ventral forebrain (the anterior hypothalamus, arcuate nucleus, anteroventral periventricular nucleus, medial preoptic nucleus, paraventricular nucleus, suprachiasmatic nucleus, and ventromedial nucleus of the hypothalamus; the basolateral, central, and medial amygdala; the lateral and principal nuclei of the bed nuclei of the stria terminalis; the caudate‐putamen; the globus pallidus; the lateral septum; and the islands of Calleja). All regions showed a significant effect of age on cell death. The timing of peak cell death varied between P1 to P7, and the average rate of cell death varied tenfold among regions. Several significant sex differences in cell death and/or regional volume were detected. These data address large gaps in the developmental literature and suggest interesting region‐specific differences in the prevalence and timing of cell death in the hypothalamus and ventral forebrain. J. Comp. Neurol. 521:2551–2569, 2013. © 2013 Wiley Periodicals, Inc.
Morphological analysis of the primary center receiving spatial information transferred by the waggle dance of honeybees
Authors: Ai Hiroyuki , Hagio Hiromi
Published: January 2013

The waggle dancers of honeybees encodes roughly the distance and direction to the food source as the duration of the waggle phase and the body angle during the waggle phase. It is believed that hive‐mates detect airborne vibrations produced during the waggle phase to acquire distance information and simultaneously detect the body axis during the waggle phase to acquire direction information. It has been further proposed that the orientation of the body axis on the vertical comb is detected by neck hairs (NHs) on the prosternal organ. The afferents of the NHs project into the prothoracic and mesothoracic ganglia and the dorsal subesophageal ganglion (dSEG). This study demonstrates somatotopic organization within the dSEG of the central projections of the mechanosensory neurons of the NHs. The terminals of the NH afferents in dSEG are in close apposition to those of Johnston's organ (JO) afferents. The sensory axons of both terminate in a region posterior to the crossing of the ventral intermediate tract (VIT) and the maxillary dorsal commissures I and III (MxDCI, III) in the subesophageal ganglion. These features of the terminal areas of the NH and JO afferents are common to the worker, drone, and queen castes of honeybees. Analysis of the spatial relationship between the NH neurons and the morphologically and physiologically characterized vibration‐sensitive interneurons DL‐Int‐1 and DL‐Int‐2 demonstrated that several branches of DL‐Int‐1 are in close proximity to the central projection of the mechanosensory neurons of the NHs in the dSEG. J. Comp. Neurol. 521:2570–2584, 2013. © 2013 Wiley Periodicals, Inc.
Biomolecule‐Assisted Construction of Cadmium Sulfide Hollow Spheres with Structure‐Dependent Photocatalytic Activity
Authors: Wei Chengzhen , Zang Wenzhe , Yin Jingzhou , Lu Qingyi , Chen Qun , Liu Rongmei , Gao Feng
Published: January 2013

In this study, we report the synthesis of monodispersive solid and hollow CdS spheres with structure‐dependent photocatalytic abilities for dye photodegradation. The monodispersive CdS nanospheres were constructed with the assistance of the soulcarboxymthyi chitosan biopolymer under hydrothermal conditions. The solid CdS spheres were corroded by ammonia to form hollow CdS nanospheres through a dissolution–reprecipitation mechanism. Their visible‐light photocatalytic activities were investigated, and the results show that both the solid and the hollow CdS spheres have visible‐light photocatalytic abilities for the photodegradation of dyes. The photocatalytic properties of the CdS spheres were demonstrated to be structure dependent. Although the nanoparticles comprising the hollow spheres have larger sizes than those comprising the solid spheres, the hollow CdS spheres have better photocatalytic performances than the solid CdS spheres, which can be attributed to the special hollow structure.
Crystal structure, dielectric properties of (K0.5Na0.5)NbO3 single crystal grown by flux method using B2O3 flux
Authors: Saravanan R. , Rajesh D. , Rajasekaran S.V. , Perumal R. , Chitra M. , Jayavel R.
Published: January 2013

Lead free piezoelectric single crystals of sodium potassium niobate (K0.5Na0.5)NbO3 (KNN) were grown by high‐temperature solution method using two different fluxes; one with a mixture of NaF and KF and other with addition of B2O3 along with the mixture. In the present study, the growth of KNN crystals without B2O3 flux and the same with B2O3 flux were compared. It was found that additions of small amounts of B2O3 lowered the melting temperature of the solid solution and enabled better dielectric properties. Phase analysis showed that all samples were crystallized in pure orthorhombic perovskite phase. AFM morphological studies showed that the addition of B2O3 flux increased the roughness of the grown crystal. Further, addition of B2O3 flux slightly decreased the orthorhombic to tetragonal phase transition temperature T(O—T) and the Curie temperature TC. The ferroelectric behaviour of KNN single crystal has been investigated at room temperature. The crystal grown using B2O3 flux exhibited a remanent polarization (Pr) ∼ 32 μC/cm2 and coercive field (Ec) of ∼11.8 kV/cm whereas the crystal grown without the use of B2O3 flux had a remanent polarization (Pr) ∼ 36 μC/cm2 and coercive field (Ec) of ∼14.6 kV/cm.
Study on crystallization kinetics and the crystal internal defects of HMX
Authors: Cao Xuhan , Duan Xiaohui , Pei Chonghua
Published: January 2013

In this paper, the solubility data of HMX (1,3,5,7‐tetranitro‐1,3,5,7‐tetrazocane) in acetone from 323.15 K to 293.15 K were accurately measured by use of the laser‐monitoring observation technique. Intermittent dynamic method was utilized to study crystallization kinetics of HMX in acetone. The data of crystallization kinetics were obtained by moment analysis, and the parameters of the growth rate and nucleation rate equations were derived by using multiple linear least squares method. Subsequently, growth rate and nucleation rate at different conditions were calculated according to these equations. In addition, Optical Microscopy Images (qualitative) and Particle Apparent Density (quantitative) experiments were applied to study the crystal internal defects of HMX under different crystallization conditions. It can be found that the crystal apparent density of HMX is in the range of 1.8993 g·cm−3 to 1.9017 g·cm−3, very close to the theory density of HMX; the internal defects and the crystal size do not increase after 25 °C, from which we predict that the HMX crystal growth reaches the steady growth segment. These results suggest that the nucleation rate is a significant factor influencing the crystal internal defects, and larger nucleation kinetics can reduce crystal internal defects.
Monodisperse CuO Hard and Hollow Nanospheres as Visible‐Light Photocatalysts
Authors: Liu Rongmei , Yin Jingzhou , Du Wei , Gao Feng , Fan Yongzhang , Lu Qingyi
Published: January 2013

In this study, we investigated the synthesis of monodisperse CuO hard and hollow nanospheres with extraordinary visible‐light photocatalytic abilities for dye photodegradation. The monodisperse CuO hard nanospheres were constructed with assistance from the water‐soluble biopolymer sodium alginate (SA). In alkaline solution, the hard CuO spheres can be gradually corroded by ammonia to form hollow CuO nanospheres under hydrothermal conditions. Their visible‐light photocatalytic activities were investigated and the results show that both of the hard and the hollow CuO spheres have great visible‐light photocatalytic abilities for the photodegradation of dyes. In particular, CuO hollow nanospheres show extraordinary photodegradation activity towards Methyl blue (MB) and it only takes 1 min for 50 mg of CuO hollow spheres to photodegrade 100 mL of 50 mg L–1 MB solution by using solar light and without the assistance of any equipment while for 50 mg of P25 (TiO2), it takes more than 30 min even under UV irradiation. As promising energy‐saving materials, CuO nanospheres would have great application potential in environment protection technology.
Thermal‐, Pressure‐ and Light‐Induced Spin‐Crossover Behaviour in the Two‐Dimensional Hofmann‐Like Coordination Polymer [Fe(3‐Clpy)2Pd(CN)4]
Authors: Martínez Víctor , Arcís Castillo Zulema , Muñoz M. Carmen , Gaspar Ana B. , Etrillard C. , Létard Jean‐François , Terekhov Sergey A. , Bukin Gennadiy V. , Levchenko Georgiy , Real José A.
Published: January 2013

The thermal spin‐crossover behaviour, photoexcitation and subsequent relaxation, as well as the pressure‐induced spin‐crossover behaviour at 298 K are discussed for the non‐porous two‐dimensional Hofmann‐like coordination polymer [Fe(3‐Clpy)2Pd(CN)4] (1). The title compound undergoes a two‐step, cooperative thermal‐induced SCO with critical temperatures Tc1↓ = 159.6 K and Tc1↑ = 164.5 K for the first step and Tc2↓ = 141.4 K and Tc2↑ = 148.4 K for the second step. Irradiation of the low‐spin state with green light (514 nm) at 10 K induced the photoexcitation of around 60 % of the iron(II) centres to the high‐spin state (LIESST effect). The subsequent cooperative relaxation processes were recorded at several temperatures and analysed. The effect of cooperativity on the photoexcitation was investigated by the LITH (light‐induced thermal hysteresis) procedure. At 300 K, the coordination polymer 1 underwent a cooperative spin‐crossover transition at around 0.6 GPa. The thermodynamic analysis of the pressure‐induced SCO transition afforded the enthalpy and cooperativity parameters ΔHHL(p) = 22.01 kJ mol–1 and Γ(p) = 7.47 kJ mol–1, consistent with previous results.
Synthesis and Biological Evaluation of α‐Tubulin‐Binding Pironetin Analogues with Enhanced Lipophilicity
Authors: Carda Miguel , Murga Juan , Díaz‐Oltra Santiago , García‐Pla Jorge , Paños Julián , Falomir Eva , Trigili Chiara , Díaz J. Fernando , Barasoain Isabel , Marco J. Alberto
Published: January 2013

Four new lipophilic analogues of the natural pyrone pironetin have been prepared. The C9 side‐chain of the latter has been replaced in one analogue by a 4‐phenylbutyl chain and in the other three analogues by C13 or C16 aliphatic chains, all of them bearing two stereogenic centres. Their cytotoxic activities and interactions with tubulin have been investigated. It was found that all four are cytotoxic towards two either sensitive or resistant tumoral cell lines with similar IC50 values in each case, which indicates that, like the parent natural compound, they also display a covalent mechanism of action. However, one of them operates in all likelihood through a mechanism very similar to pironetin, whereas the other three seem to operate through a different mechanism.
Photoinduced H‐Abstraction in Homo‐ and Protoadamantylphthalimide Derivatives in Solution and in Organized and Constrained Media
Authors: Cindro Nikola , Halasz Ivan , Mlinarić‐Majerski Kata , Basarić Nikola
Published: January 2013

The photochemical reactivity of homoadamantylphthalimide 5 and protoadamantylphthalimides 9 and 10 was investigated in solution, in the β‐cyclodextrin (CD) complex, and in the solid state. The triplet excited states of 5, 9 and 10 were characterized by laser flash photolysis. Sensitized irradiation in solution was found to give rise to polycyclic products through a transiently generated higher excited triplet state, not detectable by LFP. Direct excitation of 5, 9 and 10 gives, in addition to the products arising from the triplet state, cleavage products probably generated through a singlet state. Complexation with β‐cyclodextrin changes the regiochemistry of H‐abstraction. In the solid state, 5 and 9 are both photoreactive though state‐dependent product mixtures are noted. Irradiation of 5 affords only one product whereas irradiation of 9 affords the same product mixture regardless of whether irradiation is performed in the solid state or in CH3CN solution.
Fundamental periods of steel concentrically braced frames designed to Eurocode 8
Authors: Günaydın Egemen , Topkaya Cem
Published: January 2013

A two‐phase research program has been undertaken to investigate fundamental natural periods of concentrically braced frames (CBFs) designed according to Eurocode 8 (EC8). In the first phase of the program, over 83,700 buildings were designed, and the accuracy of the lower bound expressions given in well‐known design specifications was evaluated. The results indicated that the lower bound expressions given in EC8 and National Building Code of Canada (NBCC) are acceptable. Although all structures had periods longer than the ones estimated by the EC8 expression, a few structures had shorter periods than the ones estimated by the NBCC expression. In general, the lower bound expressions given in EC8 and NBCC were found to provide over conservative estimates for most cases. In the second phase of the program, a simple hand method was developed to estimate the fundamental natural periods of CBFs designed to EC8. This method requires the use of inelastic top story drift ratio as a parameter to quantify stiffness characteristics. The drift ratios were extracted from the design pool developed as a part of the first phase and represented by simple mathematical relationships. Evaluation of the proposed method indicated that the method is accurate in providing estimates of the fundamental period. To safeguard against providing unconservative estimates, the method was modified to arrive at a new lower bound expression, which significantly improves the estimates compared with the ones provided by the existing expressions. Copyright © 2013 John Wiley & Sons, Ltd.
Pesticides in urban streams and early life stages of pacific coho salmon
Authors: King Kerensa A. , Grue Christian E. , Grassley James M. , Fisk Robert J.
Published: January 2013

Pesticides are frequently detected in urban streams and are believed to be primarily the result of homeowner use. Although concentrations in most cases are low (<1 µg/L), there is concern that pesticide inputs threaten efforts to restore and enhance salmon habitat. The authors exposed early life stages of coho salmon (Oncorhynchus kisutch) to a pesticide mixture (“cocktail”) representative of those pesticides most frequently reported in urban streams in western Washington State, USA. Life stages were continuously exposed to pulses of the cocktail simulating those in urban streams in fall and winter when coho salmon eggs and sac fry are present. Nominal concentrations of eight herbicides, two insecticides, a fungicide, and a breakdown product were the maximum detected. Fertilization, hatching success, survival, deformities, and growth of fry were not significantly affected. A reduction in fertilization success (19–25%) was not reproducible even when gametes were exposed to 100 times the maximum concentrations detected. Based on the end points examined in the present study, the results suggest that direct exposure to the pesticides most frequently detected in urban streams in western Washington does not impair early life stages of coho salmon and is not a major factor governing the recovery of salmon populations. The extent to which pesticide exposure would affect smoltification, outmigration, and ocean survival needs to be determined. Environ. Toxicol. Chem. 2013;32:920–931. © 2013 SETAC
Regional inequity in financing New Cooperative Medical Scheme in Jiangsu, China
Authors: Dai Baozhen , Zhou Lulin , Mei Y. John , Zhan Changchun
Published: January 2013

This study examined the regional inequity in the New Cooperative Medical Scheme (NCMS) financing in Jiangsu, China. Counties were classified into three categories according to socio‐economic development level: South Jiangsu, Middle Jiangsu and North Jiangsu. Five counties (Changshu, Danyang, Gaoyou, Jiangyan and Ganyu) were selected on the basis of the following criteria: (i) NCMS had been implemented before 2005; (ii) county governments were willing and able to collaborate with the research team; and (iii) counties had different socio‐economic development status representing the low, medium and high level of socio‐economic development in Jiangsu. As shown in this study, local governments in Jiangsu took the major NCMS financing responsibilities (75.2% in 2009), and local governments (county and lower) subsidies ranged from 220 RMB per capita in South Jiangsu to 18 RMB per capita in North Jiangsu in 2009, with a larger contribution (73.3%) in South than that in Middle (40.0%) and North Jiangsu (18.0%). For achieving more equity in NCMS financing and carrying NCMS forward, we propose that provincial and municipal governments should increase their contribution to NCMS for balancing the regional inequity in subsidies from county and lower‐level governments, and the risk pool of NCMS should be promoted to a higher level (e.g., provincial). Copyright © 2013 John Wiley & Sons, Ltd.
Adenovirus 36, adiposity, and bone strength in late-adolescent females
Authors: Laing Emma M , Tripp Ralph A , Pollock Norman K , Baile Clifton A , Della-Fera Mary Anne , Rayalam Srujana , Tompkins Stephen M , Keys Deborah A , Lewis Richard D
Published: January 2013

Adenovirus 36 (Ad36) is the only adenovirus to date that has been linked with obesity in humans. Our previous studies in late-adolescent females suggest that excess weight in the form of fat mass is associated with lower cortical bone strength. The purpose of this study was to assess the relationship between Ad36-specific antibodies, adiposity, and bone strength in our sample of late-adolescent females. A cross-sectional study of 115 females aged 18 to 19 years was performed. Participants were classified according to adiposity by dual-energy X-ray absorptiometry (body fat percentage as normal-fat [ < 32% body fat; n = 93] or high-fat [ ≥ 32% body fat; n = 22]), and according to the presence of Ad36-specific neutralizing antibodies. Peripheral quantitative computed tomography measured bone parameters at the 4% (trabecular bone) and 20% (cortical bone) site, and muscle cross-sectional area (MCSA) at the 66% site, from the distal metaphyses of the radius and the tibia. Bone strength was determined from volumetric bone mineral density and bone geometry to calculate bone strength index (BSI; trabecular site) and polar strength–strain index (SSI; cortical site). After adjustment for MCSA and limb length, radial SSI was lower in Ad36+  versus Ad36– subjects from the high-fat group (p < 0.03), but not the normal-fat group. No significant differences were observed between groups in tibial SSI or BSI. These data support an association of adiposity and cortical bone strength at the radius with the presence of neutralizing antibodies to Ad36 in late-adolescent females. © 2013 American Society for Bone and Mineral Research.
Understanding the electronic energy transfer pathways in the trimeric and hexameric aggregation state of cyanobacteria phycocyanin within the framework of Förster theory
Authors: Ren Yanliang , Chi Bo , Melhem Osama , Wei Ke , Feng Lingling , Li Yongjian , Han Xinya , Li Ding , Zhang Ying , Wan Jian , Xu Xin , Yang Minghui
Published: January 2013

In the present study, the electronic energy transfer pathways in trimeric and hexameric aggregation state of cyanobacteria C‐phycocyanin (C‐PC) were investigated in term of the Förster theory. The corresponding excited states and transition dipole moments of phycocyanobilins (PCBs) located into C‐PC were examined by model chemistry in gas phase at time‐dependent density functional theory (TDDFT), configuration interaction‐singles (CIS), and Zerner's intermediate neglect of differential overlap (ZINDO) levels, respectively. Then, the long‐range pigment‐protein interactions were approximately taken into account by using polarizable continuum model (PCM) at TDDFT level to estimate the influence of protein environment on the preceding calculated physical quantities. The influence of the short‐range interaction caused by aspartate residue nearby PCBs was examined as well. Only when the protonation of PCBs and its long‐ and short‐range interactions were properly taken into account, the calculated energy transfer rates (1/K) in the framework of Förster model at TDDFT/B3LYP/6‐31+G* level were in good agreement with the experimental results of C‐PC monomer and trimer. Furthermore, the present calculated results suggested that the energy transfer pathway in C‐PC monomer is predominant from β‐155 to β‐84 (1/K = 13.4 ps), however, from α‐84 of one monomer to β‐84 (1/K = 0.3–0.4 ps) in a neighbor monomer in C‐PC trimer. In C‐PC hexamer, an additional energy flow was predicted to be from β‐155 (or α‐84) in top trimer to adjacent β‐155 (or α‐84) (1/K = 0.5–2.7 ps) in bottom trimer. © 2013 Wiley Periodicals, Inc.
Long‐range corrected functionals satisfy Koopmans' theorem: Calculation of correlation and relaxation energies
Authors: Kar Rahul , Song Jong‐Won , Hirao Kimihiko
Published: January 2013

In this article, we show that the long‐range‐corrected (LC) density functionals LC‐BOP and LCgau‐BOP reproduce frontier orbital energies and highest‐occupied molecular orbital (HOMO)—lowest‐unoccupied molecular orbital (LUMO) gaps better than other density functionals. The negative of HOMO and LUMO energies are compared with the vertical ionization potentials (IPs) and electron affinities, respectively, using CCSD(T)/6‐311++G(3df,3pd) for 113 molecules, and we found LC functionals to satisfy Koopmans' theorem. We also report that the frontier orbital energies and the HOMO‐LUMO gaps of LC‐BOP and LCgau‐BOP are better than those of recently proposed ωM05‐D (Lin et al., J. Chem. Phys. 2012, 136, 154109). We express the exact IP in terms of orbital relaxation, and correlation energies and hence calculate the relaxation and correlation energies for the same set of molecules. It is found that the LC functionals, in general, includes more relaxation effect than Hartree–Fock and more correlation effect than the other density functionals without LC scheme. Finally, we scan μ parameter in LC scheme from 0.1 to 0.6 bohr−1 for the above test set molecules with LC‐BOP functional and found our parameter value, 0.47 bohr−1, is usefully applicable to our tested systems. © 2013 Wiley Periodicals, Inc.
Automatic recalibration and processing of tandem mass spectra using formula annotation
Authors: Stravs Michael A. , Schymanski Emma L. , Singer Heinz P. , Hollender Juliane
Published: January 2013

High accuracy, high resolution tandem mass spectrometry (MS/MS) is becoming more common in analytical applications, yet databases of these spectra remain limited. Databases require good quality spectra with sufficient compound information, but processing, calibration, noise reduction and retrieval of compound information are time‐consuming tasks that prevent many contributions. We present a comprehensive workflow for the automatic processing of MS/MS using formula annotation for recalibration and cleanup to generate high quality spectra of standard compounds for upload to MassBank (www.massbank.jp). Compound information is retrieved via Internet services. Reference standards of 70 pesticides were measured at various collision energies on an LTQ‐Orbitrap XL to develop and evaluate the workflow. A total of 944 resulting spectra are now available on MassBank. Evidence of nitrogen adduct formation during MS/MS fragmentation processes was found, highlighting the benefits high accuracy MS/MS offers for spectral interpretation. A database of recalibrated, cleaned‐up spectra resulted in the most correct spectra ranked in first place, regardless of whether the search spectra were recalibrated or not, whereas the average rank of the correct molecular formula was improved from 2.55 (uncalibrated) to 1.53 when using recalibrated MS/MS data. The workflow is available as an R package RMassBank capable of generating MassBank records from raw MS and MS/MS data and can be adjusted to process data acquired with different settings and instruments. This workflow is a vital step towards addressing the need for more high quality, high accuracy MS/MS spectra in spectral databases and provides important information for spectral interpretation. Copyright © 2012 John Wiley & Sons, Ltd.
Comparative analysis of viral genomes from acute and chronic hepatitis B reveals novel variants associated with a lower rate of chronicity
Authors: Chook Jack Bee , Ngeow Yun Fong , Khang Tsung Fei , Ng Kee Peng , Tiang Yee Peng , Mohamed Rosmawati
Published: January 2013

Infection with the hepatitis B virus (HBV) may lead to an acute or chronic infection. It is generally accepted that the clinical outcome of infection depends on the balance between host immunity and viral survival strategies. In order to persist, the virus needs to have a high rate of replication and some immune‐escape capabilities. Hence, HBVs lacking these properties are likely to be eliminated more rapidly by the host, leading to a lower rate of chronicity. To test this hypothesis, 177 HBV genomes from acute non‐fulminant cases and 1,149 from chronic cases were retrieved from GenBank for comparative analysis. Selection of candidate nucleotides associated with the disease state was done using random guess cut‐off and the Bonferroni correction. Five significant nucleotides were detected using this filtering step. Their predictive values were assessed using the support vector machine classification with five‐fold cross‐validation. The average prediction accuracy was 61% ± 1%, with a sensitivity of 24% ± 1%, specificity of 98% ± 1%, positive predictive value of 92% ± 4% and negative predictive value of 56% ± 1%. BCP/X, enhancer I and surface/polymerase variants were found to be associated almost exclusively with acute hepatitis. These HBV variants are novel potential markers for non‐progression to chronic hepatitis. J. Med. Virol. 85:419–424, 2013. © 2013 Wiley Periodicals, Inc.
Prevalence of human metapneumovirus in children with acute lower respiratory infection in Changsha, China
Authors: Xiao Ni‐guang , Zhang Bing , Xie Zhi‐ping , Zhou Qiong‐hua , Zhang Rong‐fang , Zhong Li‐li , Ding Xiao‐fang , Li Jia , Song Jing‐rong , Gao Han‐chun , Hou Yun‐de , Duan Zhao‐jun
Published: January 2013

Human metapneumovirus (hMPV) causes acute respiratory infections in children. The prevalence and clinical characteristics of hMPV were determined in nasopharyngeal aspirates of children in Changsha, China. Reverse transcription‐polymerase chain reaction (RT‐PCR) or PCR was employed to screen for both hMPV and other common respiratory viruses in 1,165 nasopharyngeal aspirate specimens collected from children with lower respiratory tract infections from September 2007 to August 2008. All PCR products were sequenced, and demographic and clinical data were collected from all patients. Seventy‐six of 1,165 (6.5%) specimens were positive for hMPV, of which 85.5% (65/76) occurred in the winter and spring seasons. The hMPV coinfection rate was 57.9% (44/76), and human bocavirus was the most common virus detected in conjunction with hMPV. Phylogenetic analysis revealed that 94.7% of the hMPV detected were of subgroup A2, 5.3% were subgroup B2, and none belonged to either the A1 or B1 subgroups. No significant differences were found in terms of the frequency of diagnosis and clinical signs between either the co‐ and mono‐infection groups, or between patients with and without underlying diseases. It was concluded that hMPV is an important viral pathogen in pediatric patients with lower respiratory tract infections in Changsha. Only hMPV genotypes A2 and B2 were co‐circulating in this locality; human bocavirus was the most common coinfecting virus, and coinfection did not affect disease severity. J. Med. Virol. 85:546–553, 2013. © 2013 Wiley Periodicals, Inc.
Prevalence of human papillomavirus infection in Argentinean women attending two different hospitals prior to the implementation of the National Vaccination Program
Authors: Chouhy Diego , D'Andrea Rubén Mamprín , Iglesias Mercedes , Messina Analía , Ivancovich Juan J. , Cerda Belen , Galimberti Diana , Bottai Hebe , Giri Adriana A.
Published: January 2013

Cervarix vaccine was included in the National Immunization Program of Argentina in 2011 but data about the local distribution of human papillomavirus (HPV) infection in women exposed to the virus are scarce. This cross‐sectional study determined the prevalence and type distribution of HPV infection in unvaccinated women attending routine gynecological screening in two public hospitals located in Buenos Aires and Santa Fe, Argentina. Socio‐demographic, sexual behavior, and co‐factors information was obtained from all participants (Buenos Aires, n = 429; Santa Fe, n = 433). Cervicovaginal swabs were tested with an MY11/09 primer‐based assay and with the CUT primer system targeting mucosal/cutaneous HPVs. Participants from Buenos Aires showed significantly higher rates of HPV infection (52.4% vs. 40.6%), of multiple infections (24.2% vs. 16.4%), and of low‐risk (20.3% vs. 13.9%) and high‐risk types (44.1% vs. 33.3%) than those from Santa Fe. HPV‐66 (Buenos Aires: 17%) and HPV‐16 (Santa Fe: 8.5%) were the most prevalent types. Novel HPV‐66 putative subtype and variants were identified. Vaccine types 16 and 18 were frequent (Buenos Aires: 13.5%; Santa Fe: 10.2%) but few participants had co‐infections with both (Buenos Aires: 1.4%; Santa Fe: 0.2%). A common risk factor for HPV infection was having a new sexual partner in the last year (Buenos Aires: OR 2.53, P < 0.001; Santa Fe: OR 1.85, P = 0.04). This study provides valuable baseline data for future assessment of the impact of massive vaccination in Argentina and it underlines the use of additional HPV testing strategies, such as the CUT system, for surveillance and vaccinology. J. Med. Virol. 85:655–666, 2013. © 2013 Wiley Periodicals, Inc.
Integral geometry for \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}${\mathcal {D}}$\end{document}‐modules on dual flag manifolds and generalized Verma modules
Authors: Marastoni Corrado
Published: January 2013

Given a pair of dual generalized flag manifolds of a semisimple algebraic group, we show that the integral transform between them given by the open orbit in their product is an equivalence. We also describe the links of this problem with the structure of generalized Verma modules, and how the above construction can be applied to the representation theory of real forms of the group.
Gelation kinetics of crosslinked gelatin
Authors: Abete Tiziana , Del Gado Emanuela , de Arcangelis Lucilla
Published: January 2013

Experimental results have shown that the kinetics of bond formation in chemical crosslinking of gelatin solutions is strongly affected not only by gelatin and reactant concentrations but also by the solution pH. We present an extended numerical investigation of the phase diagram and of the kinetics of bond formation as a function of the pH, via Monte Carlo simulations of a lattice model for gelatin chains and reactant agent in solution. We find that gelation can be hindered either by loop formation, at low reactant concentrations, or by saturation of active sites of the chains via formation of single bonds with crosslinkers, at high reactant concentrations. The ratio of the characteristic times for the formation of first and the second bond between the crosslinker and an active site of a chain is found to depend on the reactant reactivity, in good agreement with experimental data. POLYM. COMPOS., 2013 © 2013 Society of Plastics Engineers
Thermal study on phenyl, hepta isobutyl‐polyhedral oligomeric silsesquioxane/polystyrene nanocomposites
Authors: Blanco Ignazio , Bottino Francesco Agatino
Published: January 2013

A comparative study concerning the thermal stability of polystyrene (PS) and three polyhedral oligomeric silsesquioxane/polystyrene (POSS/PS) nanocomposites of formula R7R′(SiO1.5)8/PS (where R = isobutyl and R′ = phenyl), at various (3, 5, and 10%) POSS concentration was carried out in both inert (flowing nitrogen) and oxidative (static air) atmospheres. Nanocomposites were synthesized by in situ polymerization of styrene in the presence of POSS and the experimental filler concentration in the obtained compounds, determined by 1H NMR spectroscopy, was in all cases slightly higher than that in the reactant mixtures. Inherent viscosity (ηinh) determinations indicated that the average molar mass of polymer in the nanocomposites was practically the same than neat PS and were in agreement with calorimetric glass transition temperature (Tg) measurements. The temperature at 5% mass loss (T5%) and the activation energy (Ea) of degradation process of synthesized nanocomposites were determined and compared with each other and with those of unfilled PS. On the basis of the results from thermal and IR spectroscopy characterizations, nanocomposite with 5% of molecular filler appears the most thermally stable. The results were also compared with literature data on similar PS‐based nanocomposites. POLYM. COMPOS., 2013 © 2013 Society of Plastics Engineers
Synthesis and chain extension of hydroxyl‐terminated poly(lactic acid) oligomers and application in the blends
Authors: Liu Junshao , Peizhen Chen , Jiang Huihua , Chen Liangbi
Published: January 2013

Hydroxyl‐terminated poly(lactic acid) prepolymer (LA prepolymer) were prepared via L‐lactic acid as monomer, 1,4‐butanediol as blocking agent and Sn(II) octoate as catalyst by direct melt polymerization. Then the LA prepolymer was blended with starch followed by in situ chain extending reaction using different content of TDI as chain extender, producing the high molecular weight of poly(ester urethane) in the blends. The LA prepolymer/starch‐TDI blends were characterized by GPC, 1H‐NMR, SEM, DSC, tensile strength testing, and water resistance. The SEM results of cross‐section show that, compared with the simple PLA/starch blends, almost the starch granules were completely covered by ploy(ester urethane) in the LA prepolymer/starch‐TDI blends system. In comparison to the simple PLA/starch blends, the mechanical properties of LA prepolymer/starch‐TDI blends were increased, such as tensile strength increasing from 18.6 ± 3.8 to 44.2 ± 6.2 Mpa, tensile modulus increasing from 510 ± 62 to 1,850 ± 125 Mpa and elongation at break increasing from 1.8 ± 0.4 to 4.0 ± 0.5 %, respectively. This is attributed to high weight of poly (ester urethane) was formed via in situ reaction of the end of hydroxyl (LA prepolymer) and isocyanate groups and the starch granules were easily covered by ploy(ether urethane) via in situ polymerization in the blends. Moreover, covalent linkage was formed between the two phases interfaces. As a result, the interfacial adhesion was enhance and improved the mechanical property. In addition, the water resistance of LA prepolymer/starch‐TDI blends was much better that of the simple PLA/starch blends. POLYM. COMPOS., 2013 © 2013 Society of Plastics Engineers
Fabrication and microwave absorption properties of BaTiO3 nanotube/polyaniline hybrid nanomaterials
Authors: Zhu Yao‐Feng , Fu Ya‐Qin , Natsuki Toshiaki , Ni Qing‐Qing
Published: January 2013

Hybrid nanomaterials consisting of BaTiO3 nanotubes (BTO NTs) and polyaniline (PANI), hereafter denoted as BTO NT/PANI, were successfully prepared by a one‐step in situ oxidative polymerization process of aniline monomers in the presence of BaTiO3 nanotubes, with ammonium persulfate as oxidant and hydrochloric acid as dopant. The structure and morphology of the nanocomposites were characterized by field emission scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, X‐ray powder diffraction, thermogravimetric analysis, and X‐ray photoelectron spectroscopy. The conductivity property of the hybrid nanomaterials was also investigated. Compared with pure polyaniline, BTO NT/PANI hybrid nanomaterials exhibited enhanced reflection loss properties, which can even be further improved with appropriate electromagnetic impedance matching. More importantly, microwave‐absorbing properties of the nanocomposites can be simply modulated simply by controlling the BaTiO3 NTs content of the absorber for the required frequency bands. Therefore, these composites may be used as lightweight andhighly effective microwave absorbers. POLYM. COMPOS., 2013 © 2013 Society of Plastics Engineers
Novel antimicrobial polymer films active against bacteria and fungi
Authors: Piotto Stefano , Concilio Simona , Sessa Lucia , Iannelli Pio , Porta Amalia , Calabrese Elena Concetta , Galdi Maria Rosaria , Incarnato Loredana
Published: January 2013

We report on the synthesis and the characterization of an azobenzene‐based compound. The molecule shows high antimicrobial activity against Staphilococcus aureus and Candida albicans, as demonstrated by in vitro microbiological test in solution. Two antimicrobial polymeric systems were realized introducing this antimicrobial molecule in two polyolefin matrices. The polymeric materials containing different percentages of azo‐compound were mold‐casted and the obtained films were tested in vitro against the same Gram‐positive bacterium and fungus. The films show biocide activity at low percentage of azo dye (up to 0.01%), holding promise for the fabrication of bacteria‐resistant polymer films by means of simple melt processing. POLYM. COMPOS., 34:1489–1492, 2013. © 2013 Society of Plastics Engineers
Preparation and physical properties of polylactide/cellulose nanowhisker/nanoclay composites
Authors: Hong Jinwook , Kim Dae Su
Published: January 2013

Polylactide (PLA) has been getting lots of interests in step with global concerns on sustainable green technology because it is biodegradable with reasonable mechanical strength and can be processed quite easily. But, to compete with commodity polymers in the market PLA‐based green composites need to have higher mechanical and thermal properties. Therefore, in this study, cellulose nanowhiskers (CNWs) as well as nanoclay were used as nanofillers to improve physical properties of PLA. CNWs were prepared from microcrystalline cellulose (MCC) powder by acid hydrolysis, and confirmed by TEM. To improve interfacial bonding between PLA and CNWs maleic anhydride‐grafted PLA (MAPLA) was prepared and used as a compatibilizer. PLA‐based composites were prepared by melt mixing followed by compression molding. Mechanical properties of the composites were measured by UTM and DMA. The melt mixing conditions were optimized first, and then composition was optimized step by step to obtain a PLA‐based green composite with excellent physical properties. CNWs were much better than MCC powder as reinforcing natural fillers. MAPLA and nanoclay could improve considerably physical properties of the PLA‐based composites. Compared to the PLA/MCC composite the tensile strength of the PLA/CNW/MAPLA/nanoclay composite was almost doubled and the glass transition temperature of the composite was 23°C higher, making the composite possible for commercial applications. POLYM. COMPOS., 2013 © 2013 Society of Plastics Engineers
Chitosan nanoparticles as therapeutic protein nanocarriers: The effect of ph on particle formation and encapsulation efficiency
Authors: Mattu Clara , Li Ruo , Ciardelli Gianluca
Published: January 2013

In the past, tripolyphosphate (TPP)‐crosslinked chitosan (CS) nanoparticles (CSNPs) have been widely applied for the delivery of biomacromolecules, because of their mild preparation conditions. However, poor uniformity and burst release limit their application to some extent. In this study, we investigated the effect of pH on the formation and on protein encapsulation efficiency (EE) of CSNPs. Results revealed that smaller particles are formed at lower pH and that the size distribution is conjointly influenced by pH and CS/TPP mass ratio. EE of bovine serum albumin (BSA) increased significantly with pH value. The influence of the pH of the crosslinker (TPP) solution was also studied, showing that CSNPs prepared with basic TPP solution (pH 9.5) had larger size, higher yield, and BSA EE compared with those obtained with acidic TPP solution (pH 5.5). Characterization by Fourier transform infrared‐attenuated total Reflectance (FTIR‐ATR) spectroscopy and SEM as well as the in vitro BSA release analysis revealed that the pH of the TPP solution might influence CSNPs' properties, by changing the conformation of polymer chains. This study analyzes the formation of CSNPs and protein encapsulation mechanisms at different pH values of both the polymer and the crosslinker solutions, suggesting strategies to overcome some of the major drawbacks of CSNPs as protein nanocarriers for therapeutic applications. POLYM. COMPOS., 34:1538–1545, 2013. © 2013 Society of Plastics Engineers
Investigation of peptide thioester formation via N→Se acyl transfer
Authors: Adams Anna L. , Macmillan Derek
Published: January 2013

Native chemical ligation is widely used for the convergent synthesis of proteins. The peptide thioesters required for this process can be challenging to produce, particularly when using Fmoc‐based solid‐phase peptide synthesis. We have previously reported a route to peptide thioesters, following Fmoc solid‐phase peptide synthesis, via an N→S acyl shift that is initiated by the presence of a C‐terminal cysteine residue, under mildly acidic conditions. Under typical reaction conditions, we occasionally observed significant thioester hydrolysis as a consequence of long reaction times (~48 h) and sought to accelerate the reaction. Here, we present a faster route to peptide thioesters, by replacing the C‐terminal cysteine residue with selenocysteine and initiating thioester formation via an N→Se acyl shift. This modification allows thioester formation to take place at lower temperatures and on shorter time scales. We also demonstrate how application of this strategy also accelerates peptide cyclization, when a linear precursor is furnished with an N‐terminal cysteine and C‐terminal selenocysteine. Copyright © 2013 European Peptide Society and John Wiley & Sons, Ltd.
Temperature quenching of Ce3+ impurity ion fluorescence in Y2O2S: Spatial confinement effect in multiphonon relaxation
Authors: Feofilov S. P. , Kulinkin A. B. , Zakharchenya R. I. , Hölsä J. , Malkamäki M.
Published: January 2013

The non‐radiative decay of the 5d excited state of Ce3+ ions in Y2O2S was studied with fluorescence spectroscopy. It is shown that temperature quenching of Ce3+ ion fluorescence is due to high‐order multiphonon relaxation. The direct evidence of spatial confinement effect in multiphonon relaxation was obtained: relaxation is more efficient in nanoparticles than in micron‐sized particles.
Eighty years of random networks
Authors: Wright A. C. , Thorpe M. F.
Published: January 2013

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The 80 years since Zachariasen's famous paper, 20 years before Stephen Elliott was born, on the random network theory of glass structure have seen remarkable progress in our understanding of the structure of glassy materials through the construction of models and comparison with experiment. In the early days, models were hand‐built with plastic units and had free boundary conditions. Today, very much larger computer models have periodic boundary conditions. We recount the progress that has been made in the last 80 years, and discuss the current agreement between models and experiments that remains imperfect. Stephen Elliott's work on medium range order forms an important part of the history of this subject.
Effect of Wine Polyphenol Resveratrol on the Contractions Elicited Electrically or by Norepinephrine in the Rat Portal Vein
Authors: Protić Dragana , Beleslin‐Čokić Bojana , Novaković Radmila , Kanjuh Vladimir , Heinle Helmut , Šćepanović Radisav , Gojković‐Bukarica Ljiljana
Published: January 2013

We investigated the effects of resveratrol on rat portal vein (RPV) contractility without endothelium. Contractions were produced by electrical field stimulation of perivascular nerves (EFS), norepinephrine (NE), adenosine 5′‐triphosphate (ATP), high K+ solution and by calcium chloride (CaCl2) in Ca2+‐free and high K+, Ca2+‐free solution. The EFS‐evoked contractions were more sensitive to resveratrol and to NS1619‐selective openers of big calcium‐sensitive (BKCa) channels, than NE‐evoked contractions. Effects of resveratrol on the ATP‐evoked contractions were weak. Blockers of BKCa channels partly inhibited the effect of resveratrol only in EFS‐contracted preparations. Western blotting showed that RPV expressed KCa1.1 protein. Inhibitors of ATP‐ and voltage‐sensitive K+ channels did not modify the effects of resveratrol. None of the antagonists of K+ channels affected the resveratrol inhibition of NE‐evoked contractions and effect of high concentrations of resveratrol on the EFS‐evoked contractions. Resveratrol more potently inhibited CaCl2 than potassium chloride contractions of RPV. Thus, BKCa channels partly mediate the inhibitory effect of resveratrol on the neurogenic contractions of RPV. The smooth muscle Ca2+ channels and/or Ca2+ mobilizing through cells might be involved in the effects of resveratrol on the contractility of RPV. Our results are important for better understanding the impact of resveratrol on the portal circulation. Copyright © 2013 John Wiley & Sons, Ltd.