bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and evaluation of artesunate–indoloquinoline hybrids as antimalarial drug candidates
Authors: Wang Ning , Wicht Kathryn J. , Shaban Elkhabiry , Ngoc Tran Anh , Wang Ming-Qi , Hayashi Ikuya , Hossain Md. Imran , Takemasa Yoshihiko , Kaiser Marcel , El Tantawy El Sayed Ibrahim , Egan Timothy J. , Inokuchi Tsutomu
Published: May 2014

Hybrids of artesunate–indoloquinoline were synthesized and antiplasmodial activity was evaluated.
A multifunctional composite of an antibacterial higher-valent silver metallopharmaceutical and a potent wound healing polypeptide: a combined killing and healing approach to wound care
Authors: Pal Sukdeb , Tak Yu Kyung , Han Eunyoung , Rangasamy Sabarinathan , Song Joon Myong
Published: May 2014

A histatin-1 and silver(ii) polydiguanide complex composite demonstrated both antibacterial and wound healing promoting activity.
Oxygen vacancy induced selective silver deposition on the {001} facets of BiOCl single-crystalline nanosheets for enhanced Cr(vi) and sodium pentachlorophenate removal under visible light
Authors: Li Hao , Zhang Lizhi
Published: May 2014

Oxygen vacancy induced selective silver deposition on the {001} facets of BiOCl can offer remarkable photocatalytic performance of Ag–BiOCl composites under visible light.
An electrospun nanowire-based triboelectric nanogenerator and its application in a fully self-powered UV detector
Authors: Zheng Youbin , Cheng Li , Yuan Miaomiao , Wang Zhe , Zhang Lu , Qin Yong , Jing Tao
Published: May 2014

A new kind of high performance triboelectric nanogenerator is developed and applied in a fully self-powered UV detector.
A study of allosteric binding behaviour of a 1,3-alternate thiacalix[4]arene-based receptor using fluorescence signal
Authors: Tomiyasu Hirotsugu , Jin Cheng-Cheng , Ni Xin-Long , Zeng Xi , Redshaw Carl , Yamato Takehiko
Published: May 2014

The allosteric binding behaviour of a receptorLbearing a 1,3-alternateconformation based thiacalix[4]arene has been evaluated by fluorescence and1H NMR titration experiments.
Transition-metal-free oxidative carboazidation of acrylamides via cascade C–N and C–C bond-forming reactions
Authors: Qiu Jun , Zhang Ronghua
Published: May 2014

A novel transition-metal-free oxidative carboazidation of acrylamides using inexpensive NaN3 and K2S2O8 was achieved, which not only provided an efficient method to prepare various N3-substituted oxindoles, but also represented a novel strategy for C–N and C–C bond formation via a free-radical cascade process.
Design, synthesis, and fungicidal activity of novel carboxylic acid amides represented by N-benzhydryl valinamode carbamates
Authors: Du Xiu-Jiang , Bian Qiang , Wang Hong-Xue , Yu Shu-Jing , Kou Jun-Jie , Wang Zhi-Peng , Li Zheng-Ming , Zhao Wei-Guang
Published: May 2014

A series of valinamide carbamate derivatives were designed and synthesized by introducing substituted aromatic rings into valinamide carbamate leads. Bioassays showed that some title compounds exhibited very good fungicidal activity.
Direct cleavage of the NN bond of azobenzenes by MeOTf leading to N-arylbenzimidazoles
Authors: Yan Xiaoyu , Yi Xiangli , Xi Chanjuan
Published: May 2014

Direct cleavage of the NN bond of azo compounds by methyltriflate (MeOTf) leading to benzimidazoles has been described without the assistance of any metals or metalloids.
From macropore to mesopore: diatomite reassembled into a multifunctional composite
Authors: Gao Hong-Wen , Xu Gang , Wang Yue
Published: May 2014

A ‘dissolving first and then reassembling’ way was presented for preparing an SN@SiO2 composite by the hybridization of an antistatic agent SN with diatomite. The colored antistatic agent was prepared by binding of the composite with a sulfonic dye. Also, it captured nonylphenol from wastewater, and the waste sludge produced was calcined to form mesoporous sieves.
A comparative study for the characterization of polyaniline based nanocomposites and membrane properties
Authors: Shahadat Mohammad , Bushra Rani , Khan Md. Ramir , Rafatullah Mohd. , Teng Tjoon Tow
Published: May 2014

Polyaniline (PANI) based novel nanocomposites have been fabricated using a simple sol–gel method.
Pulicaria glutinosa plant extract: a green and eco-friendly reducing agent for the preparation of highly reduced graphene oxide
Authors: Khan Mujeeb , Al-Marri Abdulhadi H. , Khan Merajuddin , Mohri Nils , Adil Syed Farooq , Al-Warthan Abdulrahman , Siddiqui Mohammed Rafiq H. , Alkhathlan Hamad Z. , Berger Rüdiger , Tremel Wolfgang , Tahir Muhammad Nawaz
Published: May 2014

The environmentally friendly and low cost green synthesis of highly reduced graphene oxide usingP. glutinosa
High selectivity up-converted fluorescence turn-on probe for Zn2+based on PAMAM hydroxy-naphthalene Schiff-bases (CN) half-organic quantum dots
Authors: Ji Yan , Qian Ying
Published: May 2014

Dendrimer PNS-G0 realizes an (up-converted) fluorescence turn-on effect to qualitatively and quantitatively detect Zn2+based on CN_Zn_O half-organic quantum dots (HOQDs).
Effect of co-crystallization of ethanol, pyridine and 2,2′-bipyridine on molecular aggregation in bis(1,2,3,4-tetrahydroquinolinedithiocarbamato-S,S′)mercury(ii) and synthesis of HgS nanoparticles
Authors: Srinivasan Narayanaswamy , Thirumaran Subbiah , Ciattini Samuele
Published: May 2014

Different structural motifs are obtained by co-crystallization of 2,2′-bipyridine, ethanol and pyridine with [Hg(thqdtc)2].
Stereospecific alkylation of substituted adenines by the Mitsunobu coupling reaction under microwave-assisted conditions
Authors: García-Rubiño M. E. , Núñez-Carretero M. C. , Choquesillo-Lazarte D. , García-Ruiz J. M. , Madrid Yolanda , Campos J. M.
Published: May 2014

The Mitsunobu reaction under microwave-assisted conditions reveals a complete inversion of the stereogenic centre of the secondary alcohol giving an alkylated purine linked to a homochiral six-membered ring.
Visible-light-driven MWCNT@TiO2 core–shell nanocomposites and the roles of MWCNTs on the surface chemistry, optical properties and reactivity in CO2 photoreduction
Authors: Gui Meei Mei , Chai Siang-Piao , Xu Bo-Qing , Mohamed Abdul Rahman
Published: May 2014

The light absorption performance, surface chemistry and photoreactivity of the MWCNT@TiO2 core–shell in CO2 reduction were studied.
Microwave assisted [RuCl2(p-cymene)2]2 catalyzed regioselective endo-tandem cyclization involving imine and alkyne activation: an approach to benzo[4,5]imidazo[2,1-a]pyridine scaffold
Authors: Manna Sudipta Kumar , Panda Gautam
Published: May 2014

A microwave assisted efficient route to the synthesis of benzimidazole fused heterocycles through metal catalyzed endo-cyclization strategy involving imine and alkyne activation has been developed.
Use of CdTe quantum dots for high temperature thermal sensing
Authors: Li Yangyang , Li Ben Q.
Published: May 2014

Thermal sensitive photoluminescence of CdTe quantum dots was used for micro-electromechanical systems temperature measurements in the high temperature range.
Surface platinum-rich CuPt bimetallic nanoparticles supported by partially unzipped vapor grown carbon fibers and their electrocatalytic activities
Authors: Mao Han , Zhou Lan , Huang Tao , Yu Aishui
Published: May 2014

Here we prepare the CuPt/PUVGCF catalyst made of surface platinum-rich CuPt nanoparticles anchored on partially unzipped vapor grown carbon fibers (PUVGCFs) as an anode catalyst for fuel cells.
Microfluidic fabrication of multiaxial microvessels via hydrodynamic shaping
Authors: Daniele Michael A. , Radom Kathryn , Ligler Frances S. , Adams André A.
Published: May 2014

Fabrication of small, hydrogel microvessels (radii <250 um) through hydrodynamic shaping and photoinitiated polymerization is demonstrated. Photopolymerized hydrogel microvessels were produced and examined. The process is modular and amenable to generating an array of microvessel sizes and shapes.
In-plane and out-of-plane mass transport during metal-assisted chemical etching of GaAs
Authors: Song Yunwon , Ki Bugeun , Choi Keorock , Oh Ilwhan , Oh Jungwoo
Published: May 2014

We have demonstrated the dependence of the metal-assisted chemical etching of GaAs on catalyst thickness. For ultra-thin (3~10 nm) Au catalysts, we found that electrochemically generated nano-pinholes in the metal catalyst not only enhance important catalytic effects in redox reactions, but also act as a diffusion pathway for the reactants (H2SO4) and products (Ga3+ and Asn+ ions) for chemical etching oxidized GaAs.
High piezoelectricity of BaTiO3–CaTiO3–BaSnO3 lead-free ceramics
Authors: Zhu Li-Feng , Zhang Bo-Ping , Zhao Lei , Li Jing-Feng
Published: May 2014

The ultrahigh converse piezoelectric coefficient d*33 = 1444 pm V−1 and strain 0.070%, which are the highest values reported so far in lead-free ceramics, were achieved at the component of multiphase coexistence, suggesting that the BaTiO3–CaTiO3–BaSnO3 system is a promising lead-free alternative material for electromechanical actuator applications.
Type AII lantibiotic bovicin HJ50 with a rare disulfide bond: structure, structure–activity relationships and mode of action
Authors: Zhang Jie , Feng Yingang , Teng Kunling , Lin Yuheng , Gao Yong , Wang Jinfeng , Zhong Jin
Published: May 2014

Lantibiotics are ribosomally synthesized antimicrobial peptides containing unusual amino acids. As promising alternatives to conventional antibiotics, they have a high potential for alleviating the problem of emergent antibiotic resistance, with possible applications in many industries that have antibacterial demand. Bovicin HJ50 is a type AII lantibiotic, the largest group of lantibiotics, comprising a linear N-terminal region and a globular C-terminal region. Interestingly, bovicin H50 has a disulfide bond that is rare in this group. Owing to limited information about the spatial structures of type AII lantibiotics, the functional regions of this type and the role of the disulfide bond are still unknown. In the present study, we resolved the solution structure of bovicin HJ50 using NMR spectroscopy. This is the first spatial structure of a type AII lantibiotic. Bovicin HJ50 exhibited high flexibility in aqueous solution, whereas varied rigidities were observed in the different rings with the conserved ring A being the most rigid. The charged residues Lys11, Asp12 and Lys30, as well as the essential disulfide bond were critical for antimicrobial activity. Importantly, bovicin HJ50 showed not only peptidoglycan precursor lipid II-binding ability, but also pore-forming activity, which is significantly different from other bacteriostatic type AII lantibiotics, suggesting a novel antimicrobial mechanism.
Changes in the Factor VIII C2 domain upon membrane binding determined by hydrogen–deuterium exchange MS
Authors: Pantazatos Dionysios , Gessner Christopher R. , Woods Virgil L. , Gilbert Gary E.
Published: May 2014

Factor VIII enhances the catalytic activity of Factor IXa in a membrane-bound enzyme complex and both proteins are necessary to prevent haemophilia. Tandem lectin-like C domains mediate the membrane binding of Factor VIII and membrane-interactive residues have been identified. However, the available data provide little insight into the dynamic changes that occur upon membrane binding. We used time-based hydrogen–deuterium exchange MS to evaluate the dynamics of FVIII-C2 (Factor VIII C2 domain) alone and when membrane bound. The results confirm the participation of previously identified membrane-interactive loops in the binding mechanism. In addition, they indicate that a long peptide segment, encompassing a membrane-interactive loop and strands of the β-barrel core, is remarkably dynamic prior to membrane binding. The flexibility is reduced following membrane binding. In addition, regions that interact with the A1 and C1 domains have reduced solvent exchange. Thus the isolated C2 domain has extensive flexibility that is subject to stabilization and could be related to interactions between domains as well as between Factor VIII and Factor IXa or Factor X. These results confirm that the proposed membrane-binding loops of the FVIII-C2 interact with the membrane in a manner that leads to protection from solvent exposure.
Exposure to intrauterine inflammation leads to impaired function and altered structure in the preterm heart of fetal sheep
Authors: Tare Marianne , Bensley Jonathan G. , Moss Timothy J. M. , Lingwood Barbara E. , Kim Min Y. , Barton Samantha K. , Kluckow Martin , Gill Andrew W. , De Matteo Robert , Harding Richard , Black M. Jane , Parkington Helena C. , Polglase Graeme R.
Published: May 2014

Intrauterine inflammation is a major contributor to preterm birth and has adverse effects on preterm neonatal cardiovascular physiology. Cardiomyocyte maturation occurs in late gestation in species such as humans and sheep. We tested the hypothesis that intrauterine inflammation has deleterious effects on cardiac function in preterm sheep which might be explained by altered cardiomyocyte proliferation and maturation. Pregnant ewes received an ultrasound-guided intra-amniotic injection of lipopolysaccharide (LPS) or saline 7 days prior to delivery at day 127 of pregnancy (term 147 days). Cardiac contractility was recorded in spontaneously beating hearts of the offspring, perfused in a Langendorff apparatus. Saline-filled latex balloons were inserted into the left ventricle (LV) and right ventricle (RV). Responsiveness to isoprenaline and stop-flow/reperfusion was assessed. In other experiments, hearts were perfusion-fixed, and cardiomyocyte nuclearity, volume and number were determined. β-Adrenoceptor mRNA levels were determined in unfixed tissue. In hearts of LPS-exposed fetuses, contractility in the LV and RV was suppressed by ~40% and cardiomyocyte numbers were reduced by ~25%. Immature mono-nucleated cardiomyocytes had lower volumes (~18%), whereas mature bi-nucleated cardiomyocyte volume was ~77% greater. Although basal coronary flow was significantly increased by 21±7% in LPS-exposed hearts, following ischaemia/reperfusion (IR), end-diastolic pressure was increased 2.4±0.3-fold and infarct area was increased 3.2±0.6-fold compared with those in controls. Maximum responsiveness to isoprenaline was enhanced by LPS, without an increase in β-adrenoceptor mRNA, suggesting altered second messenger signalling. Intrauterine inflammation altered cardiac growth, suppressed contractile function and enhanced responsiveness to stress. Although these effects may ensure immediate survival, they probably contribute to the increased vulnerability of organ perfusion in preterm neonates.
The Role of Primary Caregiver Vocabulary Knowledge in the Development of Bilingual Children's Vocabulary Skills
Authors: Buac Milijana , Gross Megan , Kaushanskaya Margarita
Published: May 2014

Purpose

The present study examined the impact of environmental factors (socioeconomic status [SES], the percent of language exposure to English and to Spanish, and primary caregivers' vocabulary knowledge) on bilingual children's vocabulary skills.

Method

Vocabulary skills were measured in 58 bilingual children between the ages of 5 and 7 who spoke Spanish as their native language and English as their second language. Data related to language environment in the home, specifically, the percent of language exposure to each language and SES, were obtained from primary caregiver interviews. Primary caregivers' vocabulary knowledge was measured directly using expressive and receptive vocabulary assessments in both languages.

Results

Multiple regression analyses indicated that primary caregivers' vocabulary knowledge, the child's percent exposure to each language, and SES were robust predictors of children's English, but not Spanish, vocabulary skills.

Conclusion

These findings indicate that in the early school ages, primary caregiver vocabulary skills have a stronger impact on bilingual children's second-language than native-language vocabulary.

Supplemental Material

https://doi.org/10.23641/asha.6170465
Group Lidcombe Program Treatment for Early Stuttering: A Randomized Controlled Trial
Authors: Arnott Simone , Onslow Mark , O'Brian Sue , Packman Ann , Jones Mark , Block Susan
Published: May 2014

Purpose

This study adds to the Lidcombe Program evidence base by comparing individual and group treatment of preschoolers who stutter.

Method

A randomized controlled trial of 54 preschoolers was designed to establish whether group delivery outcomes were not inferior to the individual model. The group arm used a rolling group model, in which a new member entered an existing group each time a vacancy became available. Assessments were conducted prerandomization and 9 months and 18 months postrandomization.

Results

There was no evidence of a difference between treatment arms for measures of weeks or clinic visits required, percent syllables stuttered, or parent severity ratings. However, children in the group arm consumed around half the number of speech-language pathologist hours compared with children treated individually. In addition, children in the group progressed more quickly after the treating speech-language pathologist became more practiced with the group model, suggesting the group results are conservative estimates.

Conclusions

Group delivery of the Lidcombe Program is an efficacious alternative to the individual model. Parents responded favorably to the group model, and the treating speech-language pathologists found group treatment to be more taxing but clinically gratifying.
Measurement of effective sheath width around cutoff probe in low-pressure plasmas
Authors: Kim D. W. , You S. J. , Kim J. H. , Chang H. Y. , Oh W. Y.
Published: May 2014

Previous studies indicated that the measurement results of microwave probes can be improved by applying the adequate sheath width to their measurement models, and consequently the sheath width around the microwave probe tips has become very important information for microwave probe diagnostics. In this paper, we propose a method for measuring the argon plasma sheath width around the cutoff probe tips by applying the circuit model to the cutoff probe phase spectrum. The measured sheath width of the cutoff probe was found to be in good agreement with the floated sheath width calculated from the Child-Langmuir sheath law. The physical reasons for a discrepancy between the two measurements are also discussed.
Studying protein assembly with reversible Brownian dynamics of patchy particles
Authors: Klein Heinrich C. R. , Schwarz Ulrich S.
Published: May 2014

Assembly of protein complexes like virus shells, the centriole, the nuclear pore complex, or the actin cytoskeleton is strongly determined by their spatial structure. Moreover, it is becoming increasingly clear that the reversible nature of protein assembly is also an essential element for their biological function. Here we introduce a computational approach for the Brownian dynamics of patchy particles with anisotropic assemblies and fully reversible reactions. Different particles stochastically associate and dissociate with microscopic reaction rates depending on their relative spatial positions. The translational and rotational diffusive properties of all protein complexes are evaluated on-the-fly. Because we focus on reversible assembly, we introduce a scheme which ensures detailed balance for patchy particles. We then show how the macroscopic rates follow from the microscopic ones. As an instructive example, we study the assembly of a pentameric ring structure, for which we find excellent agreement between simulation results and a macroscopic kinetic description without any adjustable parameters. This demonstrates that our approach correctly accounts for both the diffusive and reactive processes involved in protein assembly.
A combined experimental and computational study of the molecular interactions between anionic ibuprofen and water
Authors: Zapata-Escobar Andy , Manrique-Moreno Marcela , Guerra Doris , Hadad C. Z. , Restrepo Albeiro
Published: May 2014

In this work, we report a detailed study of the microsolvation of anionic ibuprofen, Ibu−. Stochastic explorations of the configurational spaces for the interactions of Ibu− with up to three water molecules at the DFT level lead to very rich and complex potential energy surfaces. Our results suggest that instead of only one preponderant structure, a collection of isomers with very similar energies would have significant contributions to the properties of the solvated drug. One of these properties is the shift on the vibrational frequencies of the asymmetric stretching band of the carboxylate group in hydrated Ibu− with respect to the anhydrous drug, whose experimental values are nicely reproduced using the weighted contribution of the structures. We found at least three types of stabilizing interactions, including conventional \documentclass[12pt]{minimal}\begin{document}${\rm CO}_2^-\cdots$\end{document} CO 2−⋯H2O, H2O⋯H2O charge assisted hydrogen bonds (HBs), and less common H2O⋯H–C and H2O⋯π interactions. Biological water molecules, those in direct contact with Ibu−, prefer to cluster around the carboxylate oxygen atoms via cyclic or bridged charge assisted hydrogen bonds. Many of those interactions are strongly affected by the formal carboxylate charge, resulting in “enhanced” HBs with increased strengths and degree of covalency. We found striking similarities between this case and the microsolvation of dymethylphosphate, which lead us to hypothesize that since microsolvation of phosphatidylcholine depends mainly on the formal charge of its ionic \documentclass[12pt]{minimal}\begin{document}${\rm PO}_2^-$\end{document} PO 2− group in the polar head, then microsolvation of anionic ibuprofen and interactions of water molecules with eukaryotic cell membranes are governed by the same types of physical interactions.
An ab initio approach to free-energy reconstruction using logarithmic mean force dynamics
Authors: Nakamura Makoto , Obata Masao , Morishita Tetsuya , Oda Tatsuki
Published: May 2014

We present an ab initio approach for evaluating a free energy profile along a reaction coordinate by combining logarithmic mean force dynamics (LogMFD) and first-principles molecular dynamics. The mean force, which is the derivative of the free energy with respect to the reaction coordinate, is estimated using density functional theory (DFT) in the present approach, which is expected to provide an accurate free energy profile along the reaction coordinate. We apply this new method, first-principles LogMFD (FP-LogMFD), to a glycine dipeptide molecule and reconstruct one- and two-dimensional free energy profiles in the framework of DFT. The resultant free energy profile is compared with that obtained by the thermodynamic integration method and by the previous LogMFD calculation using an empirical force-field, showing that FP-LogMFD is a promising method to calculate free energy without empirical force-fields.
Liquid-solid and solid-solid phase transition of monolayer water: High-density rhombic monolayer ice
Authors: Kaneko Toshihiro , Bai Jaeil , Yasuoka Kenji , Mitsutake Ayori , Zeng Xiao Cheng
Published: May 2014

Liquid-solid and solid-solid phase transitions of a monolayer water confined between two parallel hydrophobic surfaces are studied by molecular dynamics simulations. The solid phase considered is the high-density rhombic monolayer ice. Based on the computed free energy surface, it is found that at a certain width of the slit nanopore, the monolayer water exhibits not only a high freezing point but also a low energy barrier to crystallization. Moreover, through analyzing the oxygen-hydrogen-oxygen angle distribution and oxygen-hydrogen radial distribution, the high-density monolayer ice is classified as either a flat ice or a puckered ice. The transition between a flat ice and a puckered ice reflects a trade-off between the water-wall interactions and the electrostatic interactions among water molecules.
Electron-induced hydrogen loss in uracil in a water cluster environment
Authors: Smyth M. , Kohanoff J. , Fabrikant I. I.
Published: May 2014

Low-energy electron-impact hydrogen loss due to dissociative electron attachment (DEA) to the uracil and thymine molecules in a water cluster environment is investigated theoretically. Only the A′-resonance contribution, describing the near-threshold behavior of DEA, is incorporated. Calculations are based on the nonlocal complex potential theory and the multiple scattering theory, and are performed for a model target with basic properties of uracil and thymine, surrounded by five water molecules. The DEA cross section is strongly enhanced when the attaching molecule is embedded in a water cluster. This growth is due to two effects: the increase of the resonance lifetime and the negative shift in the resonance position due to interaction of the intermediate negative ion with the surrounding water molecules. A similar effect was earlier found in DEA to chlorofluorocarbons.
Transformation of potential energy surfaces for estimating isotopic shifts in anharmonic vibrational frequency calculations
Authors: Meier Patrick , Oschetzki Dominik , Berger Robert , Rauhut Guntram
Published: May 2014

A transformation of potential energy surfaces (PES) being represented by multi-mode expansions is introduced, which allows for the calculation of anharmonic vibrational spectra of any isotopologue from a single PES. This simplifies the analysis of infrared spectra due to significant CPU-time savings. An investigation of remaining deviations due to truncations and the so-called multi-level approximation is provided. The importance of vibrational-rotational couplings for small molecules is discussed in detail. In addition, an analysis is proposed, which provides information about the quality of the transformation prior to its execution. Benchmark calculations are provided for a set of small molecules.
Evaluating the applicability of the Fokker-Planck equation in polymer translocation: A Brownian dynamics study
Authors: Polson James M. , Dunn Taylor R.
Published: May 2014

Brownian dynamics (BD) simulations are used to study the translocation dynamics of a coarse-grained polymer through a cylindrical nanopore. We consider the case of short polymers, with a polymer length, N, in the range N = 21–61. The rate of translocation is controlled by a tunable friction coefficient, γ0p, for monomers inside the nanopore. In the case of unforced translocation, the mean translocation time scales with polymer length as ⟨τ1⟩ ∼ (N − Np)α, where Np is the average number of monomers in the nanopore. The exponent approaches the value α = 2 when the pore friction is sufficiently high, in accord with the prediction for the case of the quasi-static regime where pore friction dominates. In the case of forced translocation, the polymer chain is stretched and compressed on the cis and trans sides, respectively, for low γ0p. However, the chain approaches conformational quasi-equilibrium for sufficiently large γ0p. In this limit the observed scaling of ⟨τ1⟩ with driving force and chain length supports the Fokker-Planck (FP) prediction that ⟨τ⟩ ∝ N/fd for sufficiently strong driving force. Monte Carlo simulations are used to calculate translocation free energy functions for the system. The free energies are used with the FP equation to calculate translocation time distributions. At sufficiently high γ0p, the predicted distributions are in excellent agreement with those calculated from the BD simulations. Thus, the FP equation provides a valid description of translocation dynamics for sufficiently high pore friction for the range of polymer lengths considered here. Increasing N will require a corresponding increase in pore friction to maintain the validity of the FP approach. Outside the regime of low N and high pore friction, the polymer is out of equilibrium, and the FP approach is not valid.
Film growth, adsorption and desorption kinetics of indigo on SiO2
Authors: Scherwitzl Boris , Resel Roland , Winkler Adolf
Published: May 2014

Organic dyes have recently been discovered as promising semiconducting materials, attributable to the formation of hydrogen bonds. In this work, the adsorption and desorption behavior, as well as thin film growth was studied in detail for indigo molecules on silicon dioxide with different substrate treatments. The material was evaporated onto the substrate by means of physical vapor deposition under ultra-high vacuum conditions and was subsequently studied by Thermal Desorption Spectroscopy (TDS), Auger Electron Spectroscopy, X-Ray Diffraction, and Atomic Force Microscopy. TDS revealed initially adsorbed molecules to be strongly bonded on a sputter cleaned surface. After further deposition a formation of dimers is suggested, which de-stabilizes the bonding mechanism to the substrate and leads to a weakly bonded adsorbate. The dimers are highly mobile on the surface until they get incorporated into energetically favourable three-dimensional islands in a dewetting process. The stronger bonding of molecules within those islands could be shown by a higher desorption temperature. On a carbon contaminated surface no strongly bonded molecules appeared initially, weakly bonded monomers rather rearrange into islands at a surface coverage that is equivalent to one third of a monolayer of flat-lying molecules. The sticking coefficient was found to be unity on both substrates. The desorption energies from carbon covered silicon dioxide calculated to 1.67 ± 0.05 eV for multilayer desorption from the islands and 0.84 ± 0.05 eV for monolayer desorption. Corresponding values for desorption from a sputter cleaned surface are 1.53 ± 0.05 eV for multilayer and 0.83 ± 0.05 eV for monolayer desorption.
Communication: State-to-state photoionization and photoelectron study of vanadium methylidyne radical (VCH)
Authors: Luo Zhihong , Zhang Zheng , Huang Huang , Chang Yih-Chung , Ng C. Y.
Published: May 2014

By employing the infrared (IR)-ultraviolet (UV) laser excitation scheme, we have obtained rotationally selected and resolved pulsed field ionization-photoelectron (PFI-PE) spectra for vanadium methylidyne cation (VCH+). This study supports that the ground state electronic configuration for VCH+ is …7σ28σ23π49σ1 $(\tilde X$(X̃2Σ+), and is different from that of …7σ28σ23π41δ1 ($\tilde X$X̃2Δ) for the isoelectronic TiO+ and VN+ ions. This observation suggests that the addition of an H atom to vanadium carbide (VC) to form VCH has the effect of stabilizing the 9σ orbital relative to the 1δ orbital. The analysis of the state-to-state IR-UV-PFI-PE spectra has provided precise values for the ionization energy of VCH, IE(VCH) = 54 641.9 ± 0.8 cm−1 (6.7747 ± 0.0001 eV), the rotational constant B+ = 0.462 ± 0.002 cm−1, and the v2+ bending (626 ± 1 cm−1) and v3+ V–CH stretching (852 ± 1 cm−1) vibrational frequencies for VCH+($\tilde X$X̃2Σ+). The IE(VCH) determined here, along with the known IE(V) and IE(VC), allows a direct measure of the change in dissociation energy for the V–CH as well as the VC–H bond upon removal of the 1δ electron of VCH($\tilde X$X̃3Δ1). The formation of VCH+($\tilde X$X̃2Σ+) from VCH($\tilde X$X̃3Δ1) by photoionization is shown to strengthen the VC–H bond by 0.3559 eV, while the strength of the V–CH bond remains nearly unchanged. This measured change of bond dissociation energies reveals that the highest occupied 1δ orbital is nonbonding for the V–CH bond; but has anti-bonding or destabilizing character for the VC–H bond of VCH($\tilde X$X̃3Δ1).
Stability and capping of magnetite ultra-thin films
Authors: Fleischer K. , Mauit O. , Shvets I. V.
Published: May 2014

Ultrathin films of Fe3O4 have been grown epitaxially on nearly lattice matched MgO(001). The stability of 4 nm thick films in ambient air and under annealing in an oxygen atmosphere at 200 °C has been studied. By magneto optical and Raman measurements, we can confirm the presence of the Fe3O4 phase and the formation of a maghemite top layer passivating the Fe3O4 thin film. In a second step, we are able to demonstrate that this top layer oxidation in ambient air can be prevented by a 2 nm thick magnesium ferrite passivation layer, while a thicker 20 nm MgO layer prevents oxidation even at elevated temperatures.
Spin-orbit interaction tuning of perpendicular magnetic anisotropy in L1 FePdPt films
Authors: Ma X. , He P. , Ma L. , Guo G. Y. , Zhao H. B. , Zhou S. M. , Lüpke G.
Published: May 2014

The dependence of perpendicular magnetic anisotropy Ku on spin-orbit coupling strength ξ is investigated in L10 ordered FePd1−xPtx films by time-resolved magneto-optical Kerr effect measurements and ab initio density functional calculations. Continuous tuning of Ku over a wide range of magnitude is realized by changing the Pt/Pd concentration ratio, which strongly modifies ξ but keeps other leading parameters affecting Ku nearly unchanged. Ab initio calculations predict a nearly quadratic dependence of Ku on ξ, consistent with experimental data. Ku increases with increasing chemical order and decreasing thermal spin fluctuations, which becomes more significant for samples with higher Pt concentration. The results demonstrate an effective method to tune Ku utilizing its sensitivity on ξ, which will help fabricate magnetic systems with desirable magnetic anisotropy.
Ballistic electron transport calculation of strained germanium-tin fin field-effect transistors
Authors: Lan H.-S. , Liu C. W.
Published: May 2014

The dependence of ballistic electron current on Sn content, sidewall orientations, fin width, and uniaxial stress is theoretically studied for the GeSn fin field-effect transistors. Alloying Sn increases the direct Г valley occupancy and enhances the injection velocity at virtual source node. (112¯) sidewall gives the highest current enhancement due to the rapidly increasing Г valley occupancy. The non-parabolicity of the Г valley affects the occupancy significantly. However, uniaxial tensile stress and the shrinkage of fin width reduce the Г valley occupancy, and the currents are enhanced by increasing occupancy of specific indirect L valleys with high injection velocity.
Water sensor
ppk28
modulates
Drosophila
lifespan and physiology through AKH signaling
Authors: Waterson Michael J. , Chung Brian Y. , Harvanek Zachary M. , Ostojic Ivan , Alcedo Joy , Pletcher Scott D.
Published: May 2014

Significance

Sensory inputs are known to control aging. The underlying circuitry through which these cues are integrated into regulatory physiological outputs, however, remains largely unknown. Here, we use the taste sensory system of the fruit fly
Drosophila melanogaster
to detail one such circuit. Specifically, we find that water-sensing taste signals alter nutrient homeostasis and regulate a glucagon-like signaling pathway to govern production of internal water production. This metabolic alteration likely serves as a response to water sensory information. This control of metabolic state, in turn, determines the organism’s long-term health and lifespan. Our studies, then, provide a framework for understanding sensory control of aging as well as several targets to potentially maximize organismal health.
Fossil palm beetles refine upland winter temperatures in the Early Eocene Climatic Optimum
Authors: Archibald S. Bruce , Morse Geoffrey E. , Greenwood David R. , Mathewes Rolf W.
Published: May 2014

Significance

Elevated CO
2
combined with globally warm temperatures in the Eocene make its climate ideal for understanding modern global warming and its biotic consequences. Globally low temperature seasonality—the relationship between winter and mean annual temperatures—has been proposed as key to differential Eocene biodiversity and community patterns. Palms are important winter temperature indicators by their sensitivity to frost; however, their presence in paleocommunities may be masked by taphonomic constraints and identification difficulties. We used fossil obligate palm-feeding beetles to establish the presence of palms in a cool upland in midlatitude western North America. In this way, we provide a more precise characterization of climate during an important interval of the emergence of modern ecosystems.
A structure-specific nucleic acid-binding domain conserved among DNA repair proteins
Authors: Mason Aaron C. , Rambo Robert P. , Greer Briana , Pritchett Michael , Tainer John A. , Cortez David , Eichman Brandt F.
Published: May 2014

Significance

Mutations in SMARCAL1, a DNA remodeling protein fundamental to genome integrity during replication, lead to the developmental disorder Schimke immuno-osseous dysplasia (SIOD). SMARCAL1-deficient cells exhibit collapsed replication forks, S-phase cell cycle arrest, increased chromosomal breaks, hypersensitivity to genotoxic agents, and chromosomal instability. SMARCAL1 facilitates replication restart by catalyzing ATP-dependent fork regression and branch migration, the mechanism of which is poorly understood. Here we provide structural and biochemical evidence for a conserved substrate recognition domain in DNA repair enzymes that couples ATP hydrolysis to remodeling of a variety of DNA structures, and provide insight into the role of this domain in replication fork stability and genome integrity.
YY1 is indispensable for Lgr5
+
intestinal stem cell renewal
Authors: Perekatt Ansu O. , Valdez Michael J. , Davila Melanie , Hoffman A. , Bonder Edward M. , Gao Nan , Verzi Michael P.
Published: May 2014

Significance

A subset of our body’s tissues is continuously renewed through cell division. Tissue-specific stem cells support this tissue turnover, and understanding the mechanisms that control the behavior of these stem cells is important to understanding the health of the tissue. In this work, we identify a novel regulator of the intestinal stem cells. We find that, when the transcription factor YY1 is inactivated, intestinal stem cells can no longer renew themselves. We show that YY1 controls mitochondrial gene expression, and loss of YY1 results in loss of mitochondrial structural integrity. This work, therefore, provides a link between a mitochondrial regulator and stem cell function and broadens our appreciation of metabolic regulation in tissue-specific stem cells.
Mechanistic rationale for targeting the unfolded protein response in pre-B acute lymphoblastic leukemia
Authors: Kharabi Masouleh Behzad , Geng Huimin , Hurtz Christian , Chan Lai N. , Logan Aaron C. , Chang Mi Sook , Huang Chuanxin , Swaminathan Srividya , Sun Haibo , Paietta Elisabeth , Melnick Ari M. , Koeffler Phillip , Müschen Markus
Published: May 2014

Significance

The unfolded protein response (UPR) mitigates endoplasmic reticulum (ER) stress. In this regard, ER stress-inducing agents were found to be highly active in a clinical trial for children with relapsed acute lymphoblastic leukemia (ALL), a disease derived from transformed pre-B cells. To understand the efficacy of ER stress-inducing agents in pre-B ALL, we studied the relevance of the UPR pathway in genetic and patient-derived (xenograft) models of human pre-B ALL. Our studies revealed an unrecognized vulnerability of both normal pre-B cells and pre-B cell-derived ALL cells to genetic or pharmacological blockade of the UPR pathway. Our results establish a mechanistic rationale for the treatment of children with pre-B ALL with agents that block the UPR pathway and induce ER stress.
Response of
Escherichia coli
growth rate to osmotic shock
Authors: Rojas Enrique , Theriot Julie A. , Huang Kerwyn Casey
Published: May 2014

Significance

The peptidoglycan cell wall is a universal feature of bacteria that determines their shape, their effect on the human immune system, and their susceptibility to many of our front-line antibiotics. Therefore, it is essential to understand the physiology of this structure. Here, we examine the fundamental biomechanical and biochemical processes that drive cell-wall expansion during cell growth. We demonstrate that, contrary to a long-standing hypothesis, osmotic pressure is not essential for cell-wall expansion of the model bacterium
Escherichia coli
and that growth of this organism is robust to changes in osmotic pressure. This may be an important adaptation for an enteric bacterium, which regularly faces drastic changes in its osmotic environment during entry and exit from the intestine.
The linker connecting the two kringles plays a key role in prothrombin activation
Authors: Pozzi Nicola , Chen Zhiwei , Pelc Leslie A. , Shropshire Daniel B. , Di Cera Enrico
Published: May 2014

Significance

Deletion of the flexible linker connecting the two kringles of prothrombin reduces the drastic enhancement of thrombin generation by cofactor Va from >3,000-fold observed with wild-type prothrombin to only 60-fold. The change proves that deletion of the linker mimics the effect of cofactor Va on prothrombin activation. The crystal structure of the deletion mutant reveals a contorted conformation where the domains are not vertically stacked, kringle-1 comes close to the protease domain, and the Gla-domain contacts kringle-2. These findings broaden our understanding of a key reaction of the blood coagulation cascade. Cofactor Va enhances activation of prothrombin by altering the architecture of the linker and inducing a conformation similar to the structure of the deletion mutant.
RNAi-mediated silencing of hepatic
Alas1
effectively prevents and treats the induced acute attacks in acute intermittent porphyria mice
Authors: Yasuda Makiko , Gan Lin , Chen Brenden , Kadirvel Senkottuvelan , Yu Chunli , Phillips John D. , New Maria I. , Liebow Abigail , Fitzgerald Kevin , Querbes William , Desnick Robert J.
Published: May 2014

Significance

There is an unmet need for a more effective, faster-acting, and safer therapy for the life-threatening acute neurovisceral attacks that occur in the acute hepatic porphyrias. Recent studies indicate that the acute attacks are primarily caused by the neurotoxic porphyrin precursors 5-aminolevulinic acid and porphobilinogen, which accumulate as a consequence of the markedly induced expression of hepatic 5-aminolevulinic acid synthase 1 (ALAS1). Here, we demonstrate that liver-targeted small interfering RNAs specific for
Alas1
are highly effective in preventing and treating the biochemically induced acute attacks in a mouse model of acute intermittent porphyria, the most common acute hepatic porphyria. These preclinical studies provide proof-of-concept for the clinical development of RNAi-mediated therapy for the acute porphyric attacks.
Actos de cortesía valorizadora (cumplidos y halagos) en el cine argentino actual
Authors: Hernández Toribio María Isabel , Deltell Escolar Luis
Published: May 2014

En este artículo presentamos una revisión terminológica de los conceptos generalizados y vigentes en el ámbito hispano para aludir a un tipo de actos de habla (cumplidosyhalagos) que, a pesar de ser utilizados indistintamente por muchos hablantes e incluso en los estudios de cortesía, presentan diferencias semánticas y pragmáticas interesantes que no se han explicitado convenientemente en la bibliografía. No hemos encontrado al respecto una clara delimitación de los conceptos propuestos en el ámbito hispano.

Para ilustrar la distinción teórica propuesta hemos seleccionado algunos ejemplos cinematográficos extraídos de películas argentinas actuales. Aprovecharemos la posibilidad que el cine ofrece de revisar de manera interdisciplinar (desde los estudios lingüísticos de cortesía y los análisis del discurso cinematográfico) estos actos de habla: no solo mostrar su contextualización, sino también las herramientas que ofrece el propio lenguaje cinematográfico para elogiar a los protagonistas de las películas. Un análisis multimodal nos va a permitir constatar el papel que desempeñan en este sentido los recursos no verbales (paralingüísticos, cinésicos y proxémicos), así como los propiamente cinematográficos propios de la puesta en escena.
The role of Indian Diaspora in the development of the Indian IT industry
Authors: Pande Amba
Published: May 2014

Diasporas have emerged as one of the agents of development in today’s world. India’s experience with the IT industry can be cited as one of the best instances of Diasporainduced development. The Indian Diaspora has shared a symbiotic relationship with the Indian IT industry, where both have reinforced each other’s quantitative and qualitative growth over the decades. On the one hand, the Indian Diaspora brought a multi-layered gain to the IT industry in terms of enhanced skills; capital formation (human, social and financial); inward remittances; foreign direct investment flows; creation of networks/markets and a boost for India’s image. On the other hand, the Indian IT industry created a strong incentive for the mobility of highly skilled professionals and provided the Diaspora with the much needed opportunity to engage with their motherland.
Telomeropathies: An emerging spectrum disorder
Authors: Holohan Brody , Wright Woodring E. , Shay Jerry W.
Published: May 2014

A constellation of related genetic diseases are caused by defects in the telomere maintenance machinery. These disorders, often referred to as telomeropathies, share symptoms and molecular mechanisms, and mounting evidence indicates they are points along a spectrum of disease. Several new causes of these disorders have been recently discovered, and a number of related syndromes may be unrecognized telomeropathies. Progress in the clinical understanding of telomeropathies has in turn driven progress in the basic science of telomere biology. In addition, the pattern of genetic anticipation in some telomeropathies generates thought-provoking questions about the way telomere length impacts the course of these diseases.
Applying Intervention Mapping to develop a community-based intervention aimed at improved psychological and social well-being of unmarried teenage mothers in Uganda
Authors: Leerlooijer Joanne N. , Kok Gerjo , Weyusya Joseph , Bos Arjan E. R. , Ruiter Robert A. C. , Rijsdijk Liesbeth E. , Nshakira Nathan , Bartholomew Leona K.
Published: May 2014

Out-of-wedlock pregnancy among adolescents in sub-Saharan Africa is a major concern, because of its association with health, social, psychological, economic and demographic factors. This article describes the development of the Teenage Mothers Project, a community-based intervention to improve psychological and social well-being of unmarried teenage mothers in rural Uganda. We used Intervention Mapping (IM) for systematically developing a theory and evidence-based comprehensive health promotion programme. A planning group consisting of community leaders, teenage mothers, staff of a community-based organization and a health promotion professional was involved in the six steps of IM: needs assessment, programme objectives, methods and applications, intervention design, planning for adoption and implementation and planning for evaluation. The programme includes five intervention components: community awareness raising, teenage mother support groups, formal education and income generation, counselling, and advocacy. The intervention components are based on a variety of theoretical methods, including entertainment education, persuasive communication, mobilization of social networks and social action. In conclusion, IM facilitated the planning group to structure the iterative, bottom-up, participatory design of the project in a real-life setting and to use evidence and theory. The article provides suggestions for the planning of support interventions for unmarried teenage mothers.