bluuebunny/crossref_metadata_2025 huggingface dataset:
The Lineshape of the Electronic Spectrum of the Green Fluorescent Protein Chromophore, Part I: Gas Phase
Authors: Davari Mehdi D. , Ferrer Francisco J. Avila , Morozov Dmitry , Santoro Fabrizio , Groenhof Gerrit
Published: September 2014

In this work we present the vibrationally resolved optical absorption spectrum of p‐hydroxybenzylidene‐2,3‐dimethylimidazolinone (HBDI), the green fluorescent protein (GFP) chromophore, computed at several levels of theory, including time‐dependent DFT with various functionals and basis sets, CASSCF, CASPT2 and XMCQDPT2. We also investigated what happens to the spectrum if the ground‐ and excited‐state geometries are optimized at different levels of theory (mixed approach), as has been used previously. The vibrationally resolved absorption spectra obtained by DFT, CASPT2 and XMCQDPT2 are very similar and consist of a main absorption peak and a shoulder that is ∼1500 cm−1 higher in energy. The vibrational progression increases moderately with temperature. These spectra are in qualitative agreement with experimental action spectra, but much narrower and lack the long tail in the blue, even at high temperatures. Because our calculated emission spectra, which are equally narrow, are in good agreement with the emission of green fluorescent protein at 253 K, we argue that the action spectrum are too broad to be considered as the absorption spectrum. The CASSCF method and the mixed approaches overestimate the vibrational progressions with respect to CAM‐B3LYP, CASPT2 and XMCQDPT2, due to inaccuracies in the geometric S0→S1 displacements. Finally, we computed the vibronic spectra of four chromophore analogues with different substitutions on the rings and found that these substitutions hardly affect the lineshape in vacuum.
Ferrofluids: Synthetic Strategies, Stabilization, Physicochemical Features, Characterization, and Applications
Authors: Joseph Aswathy , Mathew Suresh
Published: September 2014

Ferrofluids (FFs) or magnetic nanofluids are incredible smart materials consisting of ultrafine magnetic nanoparticles suspended in a liquid carrier medium, which exhibit both fluidity and magnetic controllability. Studies involving the dynamics and physicochemical properties of these magnetic nanofluids are an interdisciplinary area of research attracting researchers from different fields of science and technology. Herein, a comprehensive Review on the different aspects of FF research is presented. First, the synthesis and stabilization of various types of FFs are discussed followed by their physicochemical features such as polydispersity, magnetic behavior, dipolar interactions, formation of chainlike aggregates, and long‐range ordering. The Review also details the rheological and thermal properties, dynamic instabilities, phase behavior, and particle assemblies in FFs to form complex multipolar geometries, photonic nanostructures, labyrinth structures, thin films, and droplets. Many important characterization techniques for probing FF properties are also briefly discussed, and the numerous innovative applications and future prospects of FFs are outlined.
Nickel Complex with Internal Bases as Efficient Molecular Catalyst for Photochemical H2 Production
Authors: Yang Yong , Wang Mei , Xue Liqin , Zhang Fengbo , Chen Lin , Ahlquist Mårten S. G. , Sun Licheng
Published: September 2014

A Ni complex with internal bases that contain bipyridine‐derived ligands, [Ni(L)2(H2O)2](BF4)2 ([1](BF4)2, L=2‐(2‐pyridyl)‐1,8‐naphthyridine), and a reference complex that bears analogous bipyridine‐derived ligands but without an internal base, [Ni(L′)3](BF4)2 ([2](BF4)2, L′=2‐(2‐pyridyl)quinoline), were synthesized and characterized. The electrochemical properties of these complexes were studied in CH3CN, H2O, and a mixture of EtOH/H2O. The fluorescence spectroscopic studies suggest that both dynamic and the sphere‐of‐action static quenching exist in the fluorescein Fl2−/[1]2+ and Fl2−/[2]2+ systems. These noble‐metal‐free molecular systems were studied for photocatalytic H2 generation. Under optimal conditions, the turnover number of H2 evolution reaches 3230 based on [1]2+, whereas [2]2+ displays only approximately one third of the turnover of [1]2+. A plausible mechanism for the catalytic H2 generation by [1]2+ is presented based on DFT calculations.
Investigation of Optical, Electrical, and Mechanical Properties of MOCVD‐grown ZrO2 Films
Authors: Dang Van‐Son , Banerjee Manish , Zhu Huaizhi , Srinivasan Nagendra Babu , Parala Harish , Pfetzing‐Micklich Janine , Wieck Andreas D. , Devi Anjana
Published: September 2014

Metal‐organic (MO)CVD of ZrO2 thin films is performed using the precursor [Zr(NMe2)2(guan)2] (guan = η2‐(iPrN)2CNMe2) as the Zr source, together with oxygen. Film deposition is carried out on both Si(100) and glass substrates at various deposition temperatures. The resulting films are characterized by X‐ray diffraction (XRD) and atomic force microscopy (AFM) for investigating the crystallinity and morphology, respectively. Optical properties are measured by ellipsometry and UV‐vis on Si substrates and glass substrates, respectively, showing a high average refractive index of 2.14 and transmittance of more than 80% in visible light for the film deposited at 500°C. The potential of ZrO2 thin films as gate dielectrics is verified by carrying out capacitance‐voltage (C‐V) and current‐voltage (I‐V) measurements. Dielectric constants are estimated from the accumulation capacitance, and found to be in the range 12 ‐ 19 at an AC frequency of 1 MHz, and a leakage current of the order of 10−6 A cm−2 at the applied field of 1 to 2 MV cm−1 is measured for the films deposited at temperatures from 500 to 700°C. The low leakage current and high dielectric constant implies the good quality of the film, relevant for high‐k applications. The hardness of the film ranges from 4.2 to 6.3 GPa for the 400 nm thick film, as determined by nano‐indentation measurements. The optimum dielectric and hardness is found for the film deposited at 600°C, while the highest refractive index is found to be 2.14 for the film deposited at 500°C, due to higher density of the layers.
Selective neuronal lineages derived from Dll4‐expressing progenitors/precursors in the retina and spinal cord
Authors: Zou Min , Luo Huijun , Xiang Mengqing
Published: September 2014

Background: During retinal and spinal cord neurogenesis, Notch signaling plays crucial roles in regulating proliferation and differentiation of progenitor cells. One of the Notch ligands, Delta‐like 4 (Dll4), has been shown to be expressed in subsets of retinal and spinal cord progenitors/precursors and involved in neuronal subtype specification. However, it remains to be determined whether Dll4 expression has any progenitor/precursor‐specificity contributing to its functional specificity during neural development. Results: We generated a Dll4‐Cre BAC transgenic mouse line that drives Cre recombinase expression mimicking that of the endogenous Dll4 in the developing retina and spinal cord. By fate‐mapping analysis, we found that Dll4‐expressing progenitors/precursors give rise to essentially all cone, amacrine and horizontal cells, a large portion of rod and ganglion cells, but only few bipolar and Müller cells. In the spinal cord, Dll4‐expressing progenitors/precursors generate almost all V2a and V2c cells while producing only a fraction of the cells for other interneuron and motor neuron subtypes along the dorsoventral axis. Conclusions: Our data suggest that selective expression of Dll4 in progenitors/precursors contributes to its functional specificity in neuronal specification and that the Dll4‐Cre line is a valuable tool for gene manipulation to study Notch signaling. Developmental Dynamics 244:86–97, 2015. © 2014 Wiley Periodicals, Inc.
Whole‐mount fluorescent in situ hybridization staining of the colonial tunicate Botryllus schlosseri
Authors: Langenbacher Adam D. , Rodriguez Delany , Di Maio Alessandro , De Tomaso Anthony W.
Published: September 2014

Botryllus schlosseri is a colonial ascidian with characteristics that make it an attractive model for studying immunology, stem cell biology, evolutionary biology, and regeneration. Transcriptome sequencing and the recent completion of a draft genome sequence for B. schlosseri have revealed a large number of genes, both with and without vertebrate homologs, but analyzing the spatial and temporal expression of these genes in situ has remained a challenge. Here, we report a robust protocol for in situ hybridization that enables the simultaneous detection of multiple transcripts in whole adult B. schlosseri using Tyramide Signal Amplification in conjunction with digoxigenin‐ and dinitrophenol‐labeled RNA probes. Using this protocol, we have identified a number of genes that can serve as markers for developing and mature structures in B. schlosseri, permitting analysis of phenotypes induced in loss‐of‐function experiments. genesis 53:194–201, 2015. © 2014 Wiley Periodicals, Inc.
The role of calcium and predation on plate morph evolution in the three‐spined stickleback (Gasterosteus aculeatus)
Authors: Smith Carl , Spence Rowena , Barber Iain , Przybylski Mirosław , Wootton Robert J.
Published: September 2014

While the genetic basis to plate morph evolution of the three‐spined stickleback (Gasterosteus aculeatus) is well described, the environmental variables that select for different plate and spine morphs are incompletely understood. Using replicate populations of three‐spined sticklebacks on North Uist, Scotland, we previously investigated the role of predation pressure and calcium limitation on the adaptive evolution of stickleback morphology and behavior. While dissolved calcium proved a significant predictor of plate and spine morph, predator abundance did not. Ecol. Evol., xxx, 2014 and xxx performed a comparable analysis to our own to address the same question. They failed to detect a significant effect of dissolved calcium on morphological evolution, but did establish a significant effect of predation; albeit in the opposite direction to their prediction.
Historical land‐use and landscape change in southern Sweden and implications for present and future biodiversity
Authors: Cui Qiao‐Yu , Gaillard Marie‐José , Lemdahl Geoffrey , Stenberg Li , Sugita Shinya , Zernova Ganna
Published: September 2014

The two major aims of this study are (1) To test the performance of the Landscape Reconstruction Algorithm (LRA) to quantify past landscape changes using historical maps and related written sources, and (2) to use the LRA and map reconstructions for a better understanding of the origin of landscape diversity and the recent loss of species diversity. Southern Sweden, hemiboreal vegetation zone. The LRA was applied on pollen records from three small bogs for four time windows between AD 1700 and 2010. The LRA estimates of % cover for woodland/forest, grassland, wetland, and cultivated land were compared with those extracted from historical maps within 3‐km radius around each bog. Map‐extracted land‐use categories and pollen‐based LRA estimates (in % cover) of the same land‐use categories show a reasonable agreement in several cases; when they do not agree, the assumptions used in the data (maps)‐model (LRA) comparison are a better explanation of the discrepancies between the two than possible biases of the LRA modeling approach. Both the LRA reconstructions and the historical maps reveal between‐site differences in landscape characteristics through time, but they demonstrate comparable, profound transformations of the regional and local landscapes over time and space due to the agrarian reforms in southern Sweden during the 18th and 19th centuries. The LRA was found to be the most reasonable approach so far to reconstruct quantitatively past landscape changes from fossil pollen data. The existing landscape diversity in the region at the beginning of the 18th century had its origin in the long‐term regional and local vegetation and land‐use history over millennia. Agrarian reforms since the 18th century resulted in a dramatic loss of landscape diversity and evenness in both time and space over the last two centuries leading to a similarly dramatic loss of species (e.g., beetles).
Cardiopulmonary exercise testing in systolic heart failure in 2014: the evolving prognostic role
Authors: Corrà Ugo , Piepoli Massimo F. , Adamopoulos Stamatis , Agostoni Piergiuseppe , Coats Andrew J.S. , Conraads Viviane , Lambrinou Ekaterini , Pieske Burkert , Piotrowicz Ewa , Schmid Jean‐Paul , Seferović Petar M. , Anker Stefan D. , Filippatos Gerasimos , Ponikowski Piotr P.
Published: September 2014

The relationship between exercise capacity, as assessed by peak oxygen consumption, and outcome is well established in heart failure (HF), but the predictive value of cardiopulmonary exercise testing (CPET) has been recently questioned, for two main reasons. First, the decisional power of CPET in the selection of heart transplantation candidates has diminished, since newer therapeutic options and the shortage of donor hearts have restricted this curative option to extremely advanced HF patients, frequently not able to perform a symptom‐limited CPET. Secondly, the use of CPET has become more complex and sophisticated, with many promising new prognostic indexes proposed each year. Thus, a modern interpretation of CPET calls for selective expertise that is not routinely available in all HF centres. This position paper examines the history of CPET in risk stratification in HF. Throughout five phases of achievements, the journey from a single CPET parameter (i.e. peak oxygen consumption) to a multiparametric approach embracing the full clinical picture in HF—including functional, neurohumoral, and laboratory findings—is illustrated and discussed. An innovative multifactorial model is proposed, with CPET at its core, that helps optimize our understanding and management of HF patients.
Long‐term follow‐up results of the Pacing to Avoid Cardiac Enlargement (PACE) trial
Authors: Yu Cheuk‐Man , Fang Fang , Luo Xiu‐Xia , Zhang Qing , Azlan Hussin , Razali Omar
Published: September 2014

Aims

We report the results of long‐term follow‐up of the Pacing to Avoid Cardiac Enlargement (PACE) trial, a prospective, double‐blinded, randomized, multicentre study that confirmed the superiority of biventricular (BiV) pacing compared with right ventricular apical (RVA) pacing in prevention of LV adverse remodelling and deterioration of systolic function at 1 and 2 years.

Methods and results

Patients with bradycardia and preserved LVEF were randomized to receive RVA (n = 88) or BiV pacing (n = 89). Co‐primary endpoints were LV end‐systolic volume (LVESV) and LVEF measured by echocardiography. There were 149 patients who had extended follow‐up, with a mean duration of 4.8 ± 1.5 years (2.5–7.8 years). The primary endpoint analyses were performed in 146 patients (74 in the RVA group and 72 in the BiV group). In the RVA pacing group, the LVEF decreased while the LVESV increased progressively at follow‐up, but remained unchanged in the BiV pacing group. The differences in LVEF between the RVA and BiV groups were –6.3, –9.2, and –10.7% at 1‐year, 2‐year, and long‐term follow‐up, respectively (all P < 0.001). The corresponding differences in LVESV were +7.4, +9.9, and +13.1 mL, respectively (all P < 0.001). The deleterious effects of RVA pacing consistently occurred in all the pre‐defined subgroups. Furthermore, patients with RVA pacing had a significantly higher prevalence of heart failure hospitalization than the BiV group (23.9% vs. 14.6%, log‐rank χ2 = 7.55, P = 0.006).

Conclusion

Left ventricular adverse remodelling and deterioration of systolic function continued at long‐term follow‐up in patients with RVA pacing; this deterioration was prevented by the use of BiV pacing. Also, heart failure hospitalization was more prevalent in the RVA pacing group.

Trial registration CUHK_CCT00037.
Synthesis and Characterization of the Nitrophenol Energetic Ionic Salts of 5,6,7,8‐Tetrahydrotetrazolo[1,5‐b][1,2,4]triazine
Authors: Wu Jin‐Ting , Zhang Jian‐Guo , Yin Xin , He Piao , Zhang Tong‐Lai
Published: September 2014

Nitrophenol energetic ionic salts based on the 5,6,7,8‐tetrahydrotetrazolo[1,5‐b][1,2,4]triazine (TZTN, 1) cation and nitrophenol anions have been synthesized in high yields by neutralization reactions. All the salts were characterized by X‐ray single‐crystal diffraction technology, IR spectroscopy, elemental analysis, and DSC measurements. The heats of formation of 2–4 were calculated by using isodesmic reactions. The calculated detonation pressures of these salts range from 29.7 to 32.6 GPa and their detonation velocities fall between 8337 and 8613 m s–1; these properties make them competitive energetic materials. In addition, the sensitivities towards impact, friction, and flame were tested, and the results indicated that salts 2 and 3 have acceptable sensitivities, whereas salt 4 shows relatively high sensitivity towards impact and flame.
Water Loss Versus Soaking Time: Spontaneous Imbibition in Tight Rocks
Authors: Lan Qing , Ghanbari Ebrahim , Dehghanpour Hassan , Hawkes Robert
Published: September 2014

The combined application of multilateral horizontal drilling and multistage hydraulic fracturing has successfully unlocked unconventional tight hydrocarbon reservoirs. However, the field data show that only a small fraction of the injected water during hydraulic fracturing treatments is recovered during flowback operations. The fate of nonrecovered water and its impact on hydrocarbon production are poorly understood. This paper aims at understanding the relationship between water loss and rock petrophysical properties. It also investigates the correlation between water loss and soaking time (well shut‐in time). Extensive spontaneous imbibition experiments are conducted on downhole samples from the shale members of the Horn River Basin and from the Montney tight gas formation. These samples are characterized by measuring porosity, mineralogy and TOC. Further, a simple methodology is used to scale up the laboratory data for predicting water imbibition volume during the shut‐in period after hydraulic fracturing operations.
Rod-shaped iron oxide nanoparticles are more toxic than sphere-shaped nanoparticles to murine macrophage cells
Authors: Lee Jang Han , Ju Jae Eun , Kim Byung Il , Pak Pyo June , Choi Eun-Kyung , Lee Hoi-Seon , Chung Namhyun
Published: September 2014

Variable sizes of nanoparticles, ranging from nano to micro scale, are of toxicological interest. In the present study, the authors hypothesized that, in addition to the size, the shape of iron oxide (Fe2O3) nanoparticles is a major factor that contributes to particle cytotoxicity. Cytotoxicity to mouse macrophage cells (RAW 264.7) was investigated using 3 different particles: micro-sized Fe2O3 (M-Fe2O3), nano-sized Fe2O3 (N-Fe2O3), and rod-shaped Fe2O3 (R-Fe2O3). Whereas M-Fe2O3 and N-Fe2O3 were located in the vacuole as aggregates, R-Fe2O3 was often spread throughout the cytoplasm. The extent of cytotoxicity measured by the water soluble tetrazolium (WST-1) assay was in the order R-Fe2O3 ≈ N-Fe2O3 > M-Fe2O3, whereas the extent revealed by the lactate dehydrogenase assay was in the order R-Fe2O3 >> N-Fe2O3 ≈ M-Fe2O3. In addition, the degree of tumor necrosis factor–α and reactive oxygen species (ROS) production was in the order of R-Fe2O3 > N-Fe2O3 > M-Fe2O3. In addition, a much higher extent of necrosis was associated with the presence of R-Fe2O3. These results suggest that the higher degree of necrosis due to R-Fe2O3 is correlated with both the higher degree of membrane damage and ROS production by R-Fe2O3 compared with the results of the other Fe2O3 particles. These results also showed that the degree of cytotoxicity of nanoparticles should be evaluated based on shape as well as size, because changes in shape and size are accompanied by alterations in surface area, which relate closely to cytotoxicity. Environ Toxicol Chem 2014;33:2759–2766. © 2014 SETAC
Frontal hypometabolism in elderly breast cancer survivors determined by [18F]fluorodeoxyglucose (FDG) positron emission tomography (PET): a pilot study
Authors: Ponto Laura L. Boles , Menda Yusuf , Magnotta Vincent A. , Yamada Torricia H. , Denburg Natalie L. , Schultz Susan K.
Published: September 2014

Purpose

The term “chemobrain” is sometimes used to denote deficits in neuropsychological functioning that may occur as a result of cancer treatment. As breast cancer survivors now commonly reach late life, it is not known whether previous exposure to chemotherapy may affect long‐term risk for cognitive impairment. To help address this concern, this study tested whether successfully surviving chemotherapy earlier in life was associated with later differences in brain metabolic function as an older adult compared to controls. This question was examined using positron emission tomography measures of brain glucose metabolism in elderly women cancer survivors.

Methods

Breast cancer survivors (N = 10), currently free of recurrent cancer and without a diagnosis of a cognitive disorder, were compared to matched healthy controls (N = 10). All subjects were imaged at rest with [18F]fluorodeoxyglucose. Images were analyzed semi‐quantitatively using the Alzheimer's Discrimination Tool and a volume of interest‐based approach derived from co‐registered magnetic resonance imaging.

Results

Relative [18F]fluorodeoxyglucose uptake (normalized to global) was significantly lower in the survivors compared with control subjects in bilateral orbital frontal regions, consistent with differences between the groups in cognition and executive function (i.e., Trail Making Test, Part B and mini‐mental state examination) and despite no significant differences with respect to age, education, intelligence, or working memory. None of the survivors and only one control manifested a global positron emission tomography score consistent with an Alzheimer's disease metabolic pattern.

Conclusion

Breast cancer survivors treated with chemotherapy may manifest long‐term changes in brain glucose metabolism indicative of subtle frontal hypometabolism, a finding consistent with results from neuropsychological testing and other imaging modalities. Copyright © 2014 John Wiley & Sons, Ltd.
Growth hormone resistance exacerbates cholestasis‐induced murine liver fibrosis
Authors: Stiedl Patricia , McMahon Robert , Blaas Leander , Stanek Victoria , Svinka Jasmin , Grabner Beatrice , Zollner Gernot , Kessler Sonja M. , Claudel Thierry , Müller Mathias , Mikulits Wolfgang , Bilban Martin , Esterbauer Harald , Eferl Robert , Haybaeck Johannes , Trauner Michael , Casanova Emilio
Published: September 2014

Growth hormone (GH) resistance has been associated with liver cirrhosis in humans but its contribution to the disease remains controversial. In order to elucidate whether GH resistance plays a causal role in the establishment and development of liver fibrosis, or rather represents a major consequence thereof, we challenged mice lacking the GH receptor gene (Ghr–/–, a model for GH resistance) by crossing them with Mdr2 knockout mice (Mdr2–/–), a mouse model of inflammatory cholestasis and liver fibrosis. Ghr–/–;Mdr2–/– mice showed elevated serum markers associated with liver damage and cholestasis, extensive bile duct proliferation, and increased collagen deposition relative to Mdr2–/– mice, thus suggesting a more severe liver fibrosis phenotype. Additionally, Ghr–/–;Mdr2–/– mice had a pronounced down‐regulation of hepatoprotective genes Hnf6, Egfr, and Igf‐1, and significantly increased levels of reactive oxygen species (ROS) and apoptosis in hepatocytes, compared to control mice. Moreover, single knockout mice (Ghr–/–) fed with a diet containing 1% cholic acid displayed an increase in hepatocyte ROS production, hepatocyte apoptosis, and bile infarcts compared to their wild‐type littermates, indicating that loss of Ghr renders hepatocytes more susceptible to toxic bile acid accumulation. Surprisingly, and despite their severe fibrotic phenotype, Ghr–/–;Mdr2–/– mice displayed a significant decrease in tumor incidence compared to Mdr2–/– mice, indicating that loss of Ghr signaling may slow the progression from fibrosis/cirrhosis to cancer in the liver. Conclusion: GH resistance dramatically exacerbates liver fibrosis in a mouse model of inflammatory cholestasis, therefore suggesting that GH resistance plays a causal role in the disease and provides a novel target for the development of liver fibrosis treatments. (Hepatology 2015;61:613‐626)
Perilipin 5 improves hepatic lipotoxicity by inhibiting lipolysis
Authors: Wang Chao , Zhao Yuanlin , Gao Xing , Li Le , Yuan Yuan , Liu Fang , Zhang Lijun , Wu Jie , Hu Peizhen , Zhang Xiumin , Gu Yu , Xu Yuqiao , Wang Zhe , Li Zengshan , Zhang Huizhong , Ye Jing
Published: September 2014

Abnormal metabolism of nonesterified fatty acids (NEFAs) and their derivatives has been reported to be the main cause of intracellular lipotoxic injury. Normally, NEFAs are stored in lipid droplets (LDs) in the form of triglyceride (TG), which could reduce the lipotoxicity of cytosolic NEFAs. Previous studies have implicated that Perilipin 5 (Plin5), an LD‐binding protein, regulates the storage and hydrolysis of TG in LD. However, its roles and underlying mechanisms in the liver remain unknown. Here we found that Plin5 expression was increased in steatotic livers. Using Plin5 knockout mice, we found that Plin5 deficiency resulted in reduced hepatic lipid content and smaller‐sized LDs, which was due to the elevated lipolysis rate and fatty acid utilization. Plin5‐deficient hepatocytes showed increased mitochondria proliferation, which could be explained by the increased expression and activity of PPARα stimulated by the increased NEFA levels. Meanwhile, Plin5‐deficient livers also exhibited enhanced mitochondrial oxidative capacity. We also found that Plin5 deficiency induces lipotoxic injury in hepatocytes, attributed to lipid peroxidation. Mechanistically, we found that Plin5 blocks adipose triglyceride lipase (ATGL)‐mediated lipolysis by competitively binding to comparative gene identification‐58 (CGI‐58) and disrupting the interaction between CGI‐58 and ATGL. Conclusion: Plin5 is an important protective factor against hepatic lipotoxicity induced by NEFAs generated from lipolysis. This provides an important new insight into the regulation of hepatic lipid storage and relation between lipid storage and lipotoxicity. (Hepatology 2015;61:870–882)
The CHARMM–TURBOMOLE interface for efficient and accurate QM/MM molecular dynamics, free energies, and excited state properties
Authors: Riahi Saleh , Rowley Christopher N.
Published: September 2014

The quantum mechanical (QM)/molecular mechanical (MM) interface between Chemistry at HARvard Molecular Mechanics (CHARMM) and TURBOMOLE is described. CHARMM provides an extensive set of simulation algorithms, like molecular dynamics (MD) and free energy perturbation, and support for mature nonpolarizable and Drude polarizable force fields. TURBOMOLE provides fast QM calculations using density functional theory or wave function methods and excited state properties. CHARMM–TURBOMOLE is well‐suited for extended QM/MM MD simulations using first principles methods with large (triple‐ζ) basis sets. We demonstrate these capabilities with a QM/MM simulation of Mg2+(aq), where the MM outer sphere water molecules are represented using the SWM4‐NDP Drude polarizable force field and the ion and inner coordination sphere are represented using QM PBE, PBE0, and MP2 methods. The relative solvation free energies of Mg2+ and Zn2+ were calculated using thermodynamic integration. We also demonstrate the features for excited state properties. We calculate the time‐averaged solution absorption spectrum of indole, the emission spectrum of the indole
excited state, and the electronic circular dichroism spectrum of an oxacepham. © 2014 Wiley Periodicals, Inc.
Meta‐analysis of high doses of ambroxol treatment for acute lung injury/acute respiratory distress syndrome based on randomized controlled trials
Authors: Wu Xiangdong , Li Suwei , Zhang Jiuzhi , Zhang Yongli , Han Lili , Deng Qiuming , Wan Xianyao
Published: September 2014

This study seeks to evaluate the potential benefits of high doses of ambroxol treatment for acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) by conducting a meta‐analysis based on randomized controlled trials (RCTs). We searched the Pubmed, Embase, China National Knowledge Infrastructure, and Wanfang databases through December 2013. Only RCTs evaluating high doses of ambroxol (≥15 mg/kg or 1000 mg/day) treatment for patients with ALI/ARDS were selected. We included 10 RCTs involving 508 patients. Adjuvant treatment with high doses of ambroxol increased PaO2/FiO2 (weight mean differences [WMD] = 69.18, 95% confidence intervals [CI]: 41.71–96.65), PO2 (WMD = 11.74, 95% CI: 8.50–14.99), and SaO2 (WMD = 2.15, 95% CI: 1.60–2.71) compared with usual treatment. Treatment with high doses of ambroxol appeared to reduce serum tumor necrosis factor‐α level (WMD −7.92 µg/L; 95% CI, −10.94 to −4.9) and interleukin‐6 level (WMD = −20.65 µg/L, 95% CI: −24.74 to −16.55) and to increase serum superoxide dismutase level (WMD = 19.07 NU/mL, 95% CI: 6.16–31.97). The findings suggest that treatment with high doses of ambroxol appears to improve PaO2/FiO2, PO2, and SaO2, and the benefits might be related to ambroxol's anti‐oxidant and anti‐inflammatory properties.
Molecular pathogenesis of intrahepatic cholangiocarcinoma
Authors: Andersen Jesper B.
Published: September 2014

Cholangiocarcinoma (CCA) is an orphan cancer of the hepatobiliary tract, the incidence of which has increased in the past decade. The molecular pathogenesis of this treatment‐refractory disease is poorly understood. Desmoplasia is a key causal feature of CCA; however, a majority of tumors develop with no apparent etiological background. The impact of the stromal compartment on tumor progression as well as resistance to therapy is in vogue, and the epithelial‐stromal crosstalk may present a target for novel treatment strategies. As such, the complexity of tumor cellularity and the molecular mechanisms underlying the diversity of growth patterns of this malignancy remain a clinical concern. It is crucial to advance our present understanding of the molecular pathogenesis of CCA to improve current clinical strategies and patient outcome. This will facilitate the delineation of patient subsets and individualization for precision therapies. Many questions persevere as to the evolutionary process and cellular origin of the initial transforming event, the context of intratumoral plasticity and the causal driver action. Next‐generation sequencing has begun to underline the persistent alterations, which may be the trigger of acquired drug resistance, and the cause of metastasis and disease recurrence. A complex issue that remains is to account for the heterogeneous pool of “backseat” aberrations, which in chromosomal proximity to the causative variant are likely to influence, for example, drug response. This review explores the recent advances in defining the molecular pathways implicated in the development of this devastating disease and, which present putative clinical strategies.
Aquaporin 4‐Dependent expression of glial fibrillary acidic protein and tenascin‐C in activated astrocytes in stab wound mouse brain and in primary culture
Authors: Ikeshima‐Kataoka Hiroko , Abe Yoichiro , Yasui Masato
Published: September 2014

We previously reported that aquaporin 4 (AQP4) has a neuroimmunological function via astrocytes and microglial cells involving osteopontin. AQP4 is a water channel localized in the endofoot of astrocytes in the brain, and its expression is upregulated after a stab wound to the mouse brain or the injection of methylmercury in common marmosets. In this study, the correlation between the expression of AQP4 and the expression of glial fibrillary acidic protein (GFAP) or tenascin‐C (TN‐C) in reactive astrocytes was examined in primary cultures and brain tissues of AQP4‐deficient mice (AQP4/KO). In the absence of a stab wound to the brain or of any stimulation of the cells, the expressions of both GFAP and TN‐C were lower in astrocytes from AQP4/KO mice than in those from wild‐type (WT) mice. High levels of GFAP and TN‐C expression were observed in activated astrocytes after a stab wound to the brain in WT mice; however, the expressions of GFAP and TN‐C were insignificant in AQP4/KO mice. Furthermore, lipopolysaccharide (LPS) stimulation activated primary culture of astrocytes and upregulated GFAP and TN‐C expression in cells from WT mice, whereas the expressions of GFAP and TN‐C were slightly upregulated in cells from AQP4/KO mice. Moreover, the stimulation of primary culture of astrocytes with LPS also upregulated inflammatory cytokines in cells from WT mice, whereas modest increases were observed in cells from AQP4/KO mice. These results suggest that AQP4 expression accelerates GFAP and TN‐C expression in activated astrocytes induced by a stab wound in the mouse brain and LPS‐stimulated primary culture of astrocytes. © 2014 Wiley Periodicals, Inc.
Eating quality of meat from six lamb breed types raised in Brazil
Authors: Monaco Carla Alves , Freire Maria T Alvarenga , Melo Lauro , Rosa Alessandra Fernandes , Carrer Celso da Costa , Trindade Marco A
Published: September 2014

BACKGROUND

Breed or genotype is important to consider for developing appropriate eating quality in lamb. The objectives of this study were to compare physical and chemical parameters and sensory acceptance of longissimus lumborum (LL) muscle from six lamb breed types economically important to the Brazilian sheep‐raising chain.

RESULTS

No difference (P > 0.05) among samples was found in relation to L*, a* and b* parameters. However, differences were detected in shear force for the LL muscle produced by different breeds (P < 0.05), where animals without definite breed (WDB) showed higher shear force, whereas the lowest levels were observed for breed Hampshire Down, followed by Ile de France and the Dorper/Santa Inês cross‐breed (Dorper/SI). In relation to sensory acceptance, no difference (P > 0.05) was detected in aroma attribute for all breed types tested. For the attributes texture, juiciness, flavor and overall quality, differences were detected (P < 0.05), Dorper/SI, Hampshire Down and Suffolk cross breeds received the best scores, while Santa Inês received intermediate evaluations, and Ile de France and WDB were the least accepted.

CONCLUSION

Under the conditions evaluated in this study, meat from Dorper/SI and Hampshire Down cross‐breeds showed better eating quality, satisfying most consumers. © 2014 Society of Chemical Industry
Fabrication of novel bundled fiber and performance assessment for clinical applications
Authors: Kim Changhwan , Jeon Myung Jin , Jung Jin Hyang , Yang Jung dug , Park Hoyong , Kang Hyun Wook , Lee Ho
Published: August 2014

Background and Objectives

During laser vaporization of benign prostate hyperplasia (BPH), high precision of optical fiber handling is pivotal to minimize any post‐operative complications. The aim of the study was to evaluate the feasible applications of a bundled fiber to treat BPH by directionally and selectively manipulating laser light onto the targeted tissue.

Methods

A bundled optical fiber, consisting of four side‐firing fibers, was fabricated to selectively emit laser beams in from one to four directions. Both transmission efficiency and light distribution were qualitatively and quantitatively characterized on the bundled fiber. In terms of interstitial application of the proposed fiber with 1064 nm on porcine liver tissue, the extent of thermal denaturation was estimated and compared at various laser parameterizations and for different directions of light.

Results

From the laser source to the fiber tip, the fabricated fiber device demonstrated a total light transmission of 52%. Due to internal light reflection, a secondary beam was emitted backward from the fiber tip and was responsible for 25% of the transmission loss. According to tissue testing, the extent of tissue denaturation generally increased with laser power, irradiation time, and number of light directions. The geometrical shape of thermal coagulation correlated well with the direction of light emission. Thermal damage to the glass tube occurred during excessive heat accumulation generated by continuous irradiation.

Conclusions

The proposed fiber can be beneficial for laser vaporization of BPH by providing a selective light direction irradiation along with minimal thermal damage. Further studies will extend the applicability of the bundled fiber to treat tubular tissue structure. Lasers Surg. Med. 46:718–725, 2014. © 2014 Wiley Periodicals, Inc.
Metallo‐Supramolecular Nanogels for Intracellular pH‐Responsive Drug Release
Authors: Yao Xuemei , Chen Li , Chen Xiaofei , He Chaoliang , Zhang Jingping , Chen Xuesi
Published: September 2014

A simple process is developed to fabricate metallo‐supramolecular nanogels (MSNs) by the metallo‐supramolecular‐coordinated interaction between histidine and iron‐meso‐tetraphenylporphin. MSNs are composed of histidine‐modified dextran (DH) and iron‐meso‐tetraphenylporphin (Fe–Por) and exhibit excellent biocompatibility and stability. MSNs show pH responsiveness in the intracellular mildly acidic environment, which has great potential for acid‐triggered drug release delivery. In vitro drug release profiles demonstrate that the pH‐dependent disassembly of MSNs to histidine and Por results in a quicker release rate of loaded‐DOX at pH 5.3, while at pH 7.4 MSNs could hinder the release of loaded‐DOX due to the enhanced stability of MSNs.

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Strategy for Good Dispersion of Well‐Defined Tetrapods in Semiconducting Polymer Matrices
Authors: Lim Jaehoon , Borg Lisa zur , Dolezel Stefan , Schmid Friederike , Char Kookheon , Zentel Rudolf
Published: September 2014

The morphology or dispersion control in inorganic/organic hybrid systems is studied, which consist of monodisperse CdSe tetrapods (TPs) with grafted semiconducting block copolymers with excess polymers of the same type. Tetrapod arm‐length and amount of polymer loading are varied in order to find the ideal morphology for hybrid solar cells. Additionally, polymers without anchor groups are mixed with the TPs to study the effect of such anchor groups on the hybrid morphology. A numerical model is developed and Monte Carlo simulations to study the basis of compatibility or dispersibility of TPs in polymer matrices are performed. The simulations show that bare TPs tend to form clusters in the matrix of excess polymers. The clustering is significantly reduced after grafting polymer chains to the TPs, which is confirmed experimentally. Transmission electron microscopy reveals that the block copolymer‐TP mixtures (“hybrids”) show much better film qualities and TP distributions within the films when compared with the homopolymer‐TP mixtures (“blends”), representing massive aggregations and cracks in the films. This grafting‐to approach for the modification of TPs significantly improves the dispersion of the TPs in matrices of “excess” polymers up to the arm length of 100 nm.
Oxygen–Nitrogen Switchable Copolymers of 2,2,2‐Trifluoroethyl Methacrylate and N,N‐Dimethylaminoethyl Methacrylate
Authors: Zhang Qi , Zhu Shiping
Published: September 2014

In this work, a novel class of O2/N2 switchable polymers is reported, which is prepared by atom transfer radical copolymerization (ATRcoP) of commercially available 2,2,2‐trifluoroethyl methacrylate (FMA) and N,N‐dimethylaminoethyl methacrylate (DMA). The copolymer is random and contains 10 FMA units and 85 DMA units. Its aqueous solution becomes transparent with O2 bubbling and turns to turbid with N2 purging. This O2/N2‐responsive switchability between the transparent and turbid states is reversible. The FMA–DMA copolymer is thermosensitive and has a lower critical solution temperature (LCST) of 24.5 °C. O2 molecules interact with fluorinated groups of the copolymer and increase the LCST to 55 °C. Purging N2 removes O2 and returns the polymer thermosensitivity back to its initial state. The switchability occurs in the whole temperature range (24.5–55 °C).

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Weißes Licht aus Nitriden
Authors: Schmiechen Sebastian , Pust Philipp , Schmidt Peter J. , Schnick Wolfgang
Published: September 2014

Außergewöhnlich schmalbandig emittierende rote Leuchtstoffe auf Nitridbasis bilden die Grundlage für eine neue Generation noch effizienterer Leuchtdioden.
Nanostrukturelle Inhomogenität in Polymernetzwerken
Authors: Lorenzo Fany Di , Seiffert Sebastian
Published: September 2014

Kettenvernetzungspunkte in polymeren Netzwerken sind oft räumlich inhomogen verteilt. Die strukturelle Inhomogenität beeinflusst die physikalischen Eigenschaften vernetzter Polymermaterialien. Dieses Wechselspiel lässt sich mit Lichtstreuung, NMR‐Spektroskopie und Fluoreszenzverfahren studieren.
Theoretical study and simulation of moisture transport in unsaturated porous media by periodic homogenization
Authors: Mchirgui W. , Millet O. , Amiri O.
Published: September 2014

In this work, the macroscopic Richards equation for moisture transport is established in unsaturated porous media using periodic homogenization. By performing dimensional analysis on microscopic equations of moisture transfer, dimensional numbers characterizing moisture transport appear. The application of the asymptotic homogenization leads to the classical Richards equation, which is justified rigorously this way. Moreover, we obtain an accurate definition of the homogenized diffusion tensor of moisture involving the geometric properties of the microstructure and known transport properties of the material. A different behavior for the transport of water vapor between hygroscopic and super‐hygroscopic region is revealed. Finally, a simple 2D example where an analytical solution exists is addressed. Copyright © 2014 John Wiley & Sons, Ltd.
Rhodamine‐Appended Bipyridine: XOR and OR Logic Operations Integrated in an Example of Controlled Metal Migration
Authors: Núñez Cristina , Santos Sergio M. , Oliveira Elisabete , Santos Hugo M. , Capelo José Luis , Lodeiro Carlos
Published: September 2014

A new bipyridyl derivative 1 bearing rhodamine B as visible fluorophore was designed, synthesized and characterized as a fluorescent and colorimetric sensor for metal ions. Interaction with Cu2+, Zn2+, Cd2+, Hg+, and Hg2+ ions was followed by UV/Vis and emission spectroscopy. Upon addition of these metal ions, different colorimetric and fluorescent responses were observed. “Off‐on‐off” (Cu2+, Zn2+, and Hg2+) and “off‐on” (Hg+ and Cd2+) systems were obtained. Probe 1 was explored to mimic XOR and OR logic operations for the simultaneous detection of Hg+–Cu2+ and Hg+–Zn2+ pairs, respectively. DFT calculations were also performed to gain insight into the lowest‐energy gas‐phase conformation of free receptor 1 as well as the atomistic details of the coordination modes of the various metal ions.
Preparation and characterization of three phase epoxy syntactic foam filled with carbon fiber reinforced hollow epoxy macrospheres and hollow glass microspheres
Authors: Wu Xinfeng , Dong Lihua , Zhang Fuhua , Zhou Yun , Wang Liping , Wang Dongsheng , Yin Yansheng
Published: September 2014

The present study focuses on the preparation and characterization of three phase epoxy syntactic foam (ESF) filled with carbon fiber reinforced hollow epoxy macrospheres (CFR‐HEMS) and hollow glass microspheres (HGMS). The ESF was produced by embedding CFR‐HEMS into a mixture of epoxy‐hardener and 30 wt% HGMS. An innovative approach and simple procedure was implemented in the preparation of CFR‐HEMS where expanded polystyrene (EPS) beads were used as initiation template. The EPS beads were coated with epoxy resin and carbon fiber using “rolling ball method,” and these coated EPS beads were later cured and post‐cured at high temperature which will shrink the EPS beads thus producing a hollow macrosphere structure. The compressive property of ESF was characterized and the mechanical model was issued. The ESF (450 kg/m3, 30.74 MPa) can withstand 2049 m water pressure and provide 550 kg/m3 buoyancy, the higher strength are due to the fiber spherical x–y network throughout the macrosphere epoxy matrix, which can give some support to the preparation of buoyancy material used in deepwater oil exploration. POLYM. COMPOS., 37:497–502, 2016. © 2014 Society of Plastics Engineers
Properties of carbon fiber reinforced poly(vinylidene fluoride)‐based friction materials of ultrasonic motors
Authors: Ding Qingjun , Zhao Gai , Peng Hanmin , Zhang Yudan , Li Huafeng
Published: September 2014

In order to improve output properties and anti‐irradiation capability of ultrasonic motors (USMs), which are driven by friction forces of friction material between the stator and rotor, a type of friction material is fabricated by composite materials consist of carbon fiber (CF) and polyvinylidene fluoride (PVDF). The effects of different contents of CF on the mechanical and tribological properties of PVDF‐based friction materials are studied, and the mechanical features of the relative USMs are measured. Further, the worn surface morphology of PVDF composites is observed by means of scanning electron microscope and the wear mechanisms are also discussed. In addition, the anti‐irradiation capability of the type of friction materials is measured by the γ‐ray irradiation at room temperature environment with the total radiation dose of 4.0X rad (Si). The experimental results show that the incorporation of CF into PVDF can effectively improve the friction and wear properties of the friction materials, and the mechanical properties of TRUM‐60 used by relative PVDF composites are also increased with the increase of CF. For TRUM‐60, both the no‐load speed and holding torque of the USMs were high, and the wear of friction material was lowest, when the CF content is 15 wt%. The experiment results also show that this PVDF‐based friction material has a good anti‐irradiation property. Therefore, the composite materials consist of CF and PVDF are beneficial for the applications in USMs, especially for some radiation environment. POLYM. COMPOS., 37:547–552, 2016. © 2014 Society of Plastics Engineers
Half a century of research, teaching, service
Authors: Perrin Charles L.
Published: September 2014

This is a summary of the research of Charles L. Perrin and his coworkers in the areas of aromatic mercuration, vibronic borrowing, ipso factors in electrophilic aromatic substitution, malonic anhydrides, mechanisms of proton exchange in amides, stereoelectronic control, the so‐called reverse anomeric effect, an NMR titration method for highly accurate measurement of relative acidities, secondary deuterium isotope effects on acidity, symmetry of hydrogen bonds in solution, and nucleophilic addition to a para‐benzyne diradical, along with Perrin's contributions to teaching and to service. Copyright © 2014 John Wiley & Sons, Ltd.
Crystallization and orientation of isotactic poly(propylene) in cylindrical nanopores
Authors: Reid Dariya K. , Ehlinger Bridget A. , Shao Lin , Lutkenhaus Jodie L.
Published: August 2014

The crystallization of polymers in cylindrical geometries is important as interest in polymer nanowires and nanostructures grows. Here, semicrystalline isotactic poly(propylene) (iPP) is shown to crystallize in a homogeneous, low‐dimensional fashion when confined in cylindrical pores as small as 15 nm. A strong dependence on pore diameter is demonstrated. Isothermal crystallization studies suggest a reduced Avrami exponent as pore diameter decreases and as crystallization time increases. Complementary X‐ray diffraction with tilt (texture analysis) reveals one‐dimensional ordering of iPP crystals within pores of 40 nm diameter or less in which crystals preferentially orient, perpendicular to the pore wall. These findings demonstrate that the origin of this orientation is related to the impingement of crystals against the pore wall, thus “freezing out” polymer crystallizing in nonpreferred directions. These results show that curvature‐directed crystallization is one potential means to control a polymer's crystallization rate and orientation. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014, 52, 1412–1419