bluuebunny/crossref_metadata_2025 huggingface dataset:
A Structure‐Guided Switch in the Regioselectivity of a Tryptophan Halogenase
Authors: Shepherd Sarah A. , Menon Binuraj R. K. , Fisk Heidi , Struck Anna‐Winona , Levy Colin , Leys David , Micklefield Jason
Published: February 2016

Flavin‐dependent halogenases are potentially useful biocatalysts for the regioselective halogenation of aromatic compounds. Haloaromatic compounds can be utilised in the synthesis and biosynthesis of pharmaceuticals and other valuable products. Here we report the first X‐ray crystal structure of a tryptophan 6‐halogenase (SttH), which enabled key residues that contribute to the regioselectivity in tryptophan halogenases to be identified. Structure‐guided mutagenesis resulted in a triple mutant (L460F/P461E/P462T) that exhibited a complete switch in regioselectivity; with the substrate 3‐indolepropionate 75 % 5‐chlorination was observed with the mutant in comparison to 90 % 6‐chlorination for the wild‐type SttH. This is the first clear example of how regiocomplementary halogenases can be created from a single parent enzyme. The biocatalytic repertoire of SttH was also expanded to include a range of indolic and non‐indolic substrates.
A Comparative Study of Fuzzy Techniques to Handle Uncertainty: An Industrial Grinding Process
Authors: Virivinti Nagajyothi , Mitra Kishalay
Published: February 2016

The deterministic optimization models for chemical processes assume perfect information, i.e., the system parameters involved in the models should have fixed values. However, the knowledge about these parameters is often either not easy to obtain or, if available, subjected to uncertainty involved in determining them (e.g. experiments, regression etc.). The optimization results obtained using these deterministic models are, therefore, not robust to uncertainties in the parameters of the system. In this work, fuzzy based approaches, e.g. fuzzy chance constrained programming (FCCP) and fuzzy expected value model (FEVM), have been applied to a multi‐objective optimization problem of the industrial grinding process to carry out the uncertainty analysis and the results are compared with respect to the power of risk averseness adopted in the approaches used. These methods assume the uncertain parameters as fuzzy numbers and membership function is used to represent the degree of uncertainty in them. The extent of constraint satisfaction due to the presence of uncertain parameters can be accommodated assuming credibility of constraint satisfaction under FCCP framework whereas the robust set of parameters in the FEVM approach is determined by considering the expectation terms for objectives and constraints. Moreover, the issue of nonlinear relation of uncertain parameters has been handled by adopting simulation based approaches while computing the credibility. The results obtained by FCCP technique show how the presence of uncertainty leads to an operating zone of varied risk appetite of a decision maker by using different uncertain measures such as credibility, possibility and necessity. These approaches are very generic and can be adopted for the study of parametric sensitivity for any process model in a novel manner.
Adsorption of Nickel Ions on Oxygen‐Functionalized Carbons
Authors: Kern Andreas M. , Zierath Bodo , Fey Tobias , Etzold Bastian J. M.
Published: February 2016

The adsorption of nickel(II) ions on pristine and wet‐chemically oxidized microporous carbons is studied. The nature and acidity of the resulting oxygen functional groups are characterized by temperature‐programmed desorption and point of zero charge measurements. The maximal nickel ion adsorption capacity of the resulting high‐affinity Langmuir‐type adsorption equilibrium is strongly influenced by the oxidative pretreatment. At maximum, loadings of 7.5 wt % could be obtained for carbons showing oxygen content of 12.5 mmol g−1. A linear correlation of the ion uptake with the surface oxygen content could be deduced. In a kinetic study, it could be proved that the uptake of nickel at room temperature is a slow process and that the time for adsorption is independent of oxygen content, carbon type, and nickel loading.
Lanthanide‐Doped Nanoparticles with Near‐Infrared‐to‐Near‐Infrared Luminescence for Bioimaging
Authors: Wei Yurong , Yang Xiangdong , Ma Yurou , Wang Shengfu , Yuan Quan
Published: February 2016

Lanthanide (Ln, or rare‐earth) doped nanoparticles are well‐known for their prominent optical properties and have been widely used for biological applications, especially in biological assays and medical imaging. Recently, the extensive attention of near infrared (NIR) wavelength range has dramatically increased for its fast feedback, high spatial resolution and deep tissue penetration. Tissues have minimal absorbance in this region. While a lot of excellent reviews cover various aspects of biomedical imaging based on lanthanide doped nanoparticles, there has not been a review that systematically summarizes NIR‐to‐NIR imaging with lanthanide doped nanoparticles. In this review, we focus on the recent development of NIR‐to‐NIR imaging based on lanthanide doped nanoparticles, and discuss challenges and opportunities in it.
Folic Acid Functionalized PFBT Fluorescent Polymer Dots for Tumor Imaging
Authors: Cao Fengwen , Xiong Liqin
Published: February 2016

Folic acid functionalized PFBT‐COOH and PFBT‐NH2 polymer dots were prepared using a nano precipitation method, and their applications for tumor imaging in vitro and in vivo were demonstrated for the first time. The synthesized FA‐PFBT‐COOH polymer dots were 50–60 nm in diameter with a zeta potential of greater than −30 mV in water, while the synthesized FA‐PFBT‐NH2 polymer dots were 90–105 nm in diameter with a zeta potential of greater than −20 mV in water. Furthermore, the FA‐PFBT‐COOH polymer dots produced stronger fluorescence intensity in water solution as well as in the cells than the FA‐PFBT‐NH2 polymer dots, and were able to image H1299 tumors in living mice after intravenous injection. This study showed the great potentials of FA‐PFBT‐COOH polymer dots as fluorescent nanoprobes for biomedical imaging.
Design and Fabrication of Plasmonic Nanostructures with DNA for Surface‐Enhanced Raman Spectroscopy Applications
Authors: Leng Chunbo , Wang Cheng , Xiu Huixin , Qu Xiangmeng , Chen Lizhen , Tang Qian , Li Li
Published: February 2016

Plasmonic nanostructures display unique and strongly enhanced optical properties, therefore hold great promise for a wide range of spectroscopic applications, particularly surface‐enhanced Raman spectroscopy (SERS). It is well acknowledged that the major contributions to SERS arise from molecules positioned in nanojunctions where the optical field is intensively concentrated due to localized surface plasmon excitations. One of the key challenges in SERS therefore lies in the design and fabrication of plasmonic nanostructures with controllable nanojunctions. In recent years, by exploiting the unparalleled base‐pairing self‐recognition properties, DNA‐mediated assembly has emerged as a powerful and programmable tool for the accurate construction of complex and hierarchical plasmonic nanostructures with well‐defined geometry and topology. In this review, we will summarize recent advances on design and fabrication of a rich variety of plasmonic nanostructures by virtue of DNA nanotechnology, and discuss their optical properties as well as applications in SERS.
Self‐Assembled DNA Nanostructures for Drug Delivery
Authors: Jia Ruokun , Wang Ting , Jiang Qiao , Wang Zhengang , Song Chen , Ding Baoquan
Published: February 2016

Due to the uniform nanoscale sizes, well‐defined shapes, precise spatial addressability and prominent biocompatibility, self‐assembled DNA nanostructures have been intensively studied for their biomedical applications. This review summarizes the recent development of DNA nanotechnology in cancer therapy, and discusses the challenges and potential strategies to advance the methodologies of cancer treatments.
DNA Directed Self‐Assembly of Fluorescent Colloidal Semiconductor Quantum Dots and Plasmonic Metal Nanoparticles Heterogeneous Nanomaterials
Authors: Guo Yan , Hu Yue , Deng Zhengtao
Published: February 2016

The exciton‐plasmon interaction between fluorescent colloidal semiconductor quantum dots and plasmonic metal nanoparticles may lead to emission quenching or enhancement of quantum dots, which have potential applications in renewable energy, nanophotonics, and biosensing. Semiconductor quantum dots and metal nanoparticles hybrids with controlled geometry, distance, and stoichiometry are crucial for the potential applications. While DNA nanotechnology, based on Watson‐Crick base‐pairing interactions between two single‐stranded DNAs, has provided unique opportunities to generate fully programmable, functional metal nanoparticles and semiconductor quantum dots hybrid nanomaterials, and offers precisely control over the spacing, orientation, and chirality of the components. This review provides the highlights of the recent progresses in DNA directed self‐assembly of colloidal semiconductor quantum dots and metallic nanoparticles heterogeneous nanomaterials. We also discuss the challenges and the trends in DNA directed self‐assembly of semiconductor quantum dots and metallic nanoparticles hybrid nanomaterials.
Biomedical Applications of DNA‐Nanomaterials Based on Metallic Nanoparticles and DNA Self‐Assembled Nanostructures
Authors: Wen Yanli , Li Lanying , Wang Lele , Xu Li , Liang Wen , Ren Suzhen , Liu Gang
Published: February 2016

DNA is the carrier of genetic information, and its sequence can be designed to realize many important functions, including DNAzyme, aptamer and even structurally precise nanomaterials. The development of DNA nanotechnology combined functional nucleic acids with nanomaterials for various effective biomedical applications. Here, we reviewed the application of DNA‐nanomaterials in two biomedical fields: early diagnosis and drug delivery. And in each field, we mainly focused on two kinds of nanomaterials: metallic nanoparticles and DNA self‐assembled nanomaterials. DNA metallic nanomaterials showed unique optical, electronic and magnetic properties in bioanalysis, and when functioned by DNA, their specificity was improved for both biosensor development and drug delivery. More recently, many DNA self‐assembled nanomaterials were introduced into biomedical application for their well‐defined structure and excellent biocompatibility. We summarized the research of these two kinds of DNA‐nanomaterials for biomedical purposes, and finally made some prospection about their future development.
Depression and Multiple Rehospitalizations in Patients With Heart Failure
Authors: Freedland Kenneth E. , Carney Robert M. , Rich Michael W. , Steinmeyer Brian C. , Skala Judith A. , Dávila‐Román Victor G.
Published: February 2016

Background

There have been few studies of the effect of depression on rehospitalization in patients with heart failure (HF), and even fewer on its role in multiple rehospitalizations.

Hypothesis

Depression is an independent risk factor for multiple readmissions in patients with HF.

Methods

A cohort of 662 patients with HF who were discharged alive after hospitalization were interviewed to evaluate symptoms of depression and were followed for 1 year. All‐cause readmissions were documented by chart review. A marginal proportional rates model was used to model the effect of depression on the rate of rehospitalization with adjustment for known predictors of HF outcomes.

Results

Depression symptoms predicted multiple readmissions (adjusted hazard ratio [HR]: 1.08, 95% confidence interval [CI]: 1.03‐1.13, P = 0.0008). Compared with patients without depression, those who met the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM‐IV) criteria for major depression at index were at the highest risk for multiple rehospitalizations (HR: 1.51, 95% CI: 1.15‐1.97, P = 0.003).

Conclusions

Depression is an independent risk factor for multiple all‐cause readmissions in patients with HF.
Estimating spectral reflectance from camera responses based on CIEXYZ tristimulus values under multi‐illuminants
Authors: Zhang Xiandou , Wang Qiang , Li Jincheng , Zhou Xiaohui , Yang Yuechuan , Xu Haisong
Published: February 2016

A new spectral reflectance estimation method based on CIE XYZ values under multi‐illuminants was proposed to obtain multi‐spectral images accurately by using digital still cameras. CIE XYZ values under multi‐illuminants were initially predicted from raw RGB responses by using a polynomial model with local training samples. Then, spectral reflectance was constructed from the predicted CIE XYZ values via the pseudo‐inverse method. Experimental results indicated that the new spectral reflectance estimation method significantly outperformed the traditional colorimetric characterization method without requiring extra training samples or greatly increasing computational complexities. © 2016 Wiley Periodicals, Inc. Col Res Appl, 42, 68–77, 2017
Anomalous Freezing of Nano‐Confined Water in Room‐Temperature Ionic Liquid 1‐Butyl‐3‐Methylimidazolium Nitrate
Authors: Abe Hiroshi , Takekiyo Takahiro , Yoshimura Yukihiro , Saihara Koji , Shimizu Akio
Published: February 2016

Non‐crystal formation of ice is investigated by simultaneous X‐ray diffraction and differential scanning calorimetry measurements upon cooling to −100 °C. At room temperature, size‐tunable water confinement (≈20 Å size) in a room‐temperature ionic liquid (RTIL, 1‐butyl‐3‐methylimidazolium nitrate, [C4mim][NO3]) exists in a water‐rich region (70–90 mol % D2O). The confined water (water pocket) is characterized by almost monodispersive size distribution. In [C4mim][NO3]‐x mol % D2O (70<x<94), the absence of sharp Bragg reflections and a distinct exothermal peak indicate that crystallization/cold crystallization both of [C4mim][NO3] and D2O is suppressed, even upon slow cooling and heating.
Epigenetics and addiction
Authors: Cadet JL , McCoy MT , Jayanthi S
Published: February 2016

Addictions are public health menaces. However, despite advances in addiction research, the cellular or molecular mechanisms that cause transition from recreational use to addiction remain to be elucidated. We have recently suggested that addiction may be secondary to long‐term epigenetic modifications that determine the clinical course of substance use disorders. A better understanding of epigenetic mechanisms in animal models that mimic human conditions should help to usher in a new area of drug development against addiction.
Correlates of health related quality of life in anorexia nervosa
Authors: Weigel Angelika , König Hans‐Helmut , Gumz Antje , Löwe Bernd , Brettschneider Christian
Published: February 2016

Objective

We examined the association between disorder specific factors, comorbidity and health related quality of life (HRQoL) in anorexia nervosa (AN).

Method

HRQoL was assessed using the EuroQol‐5D visual analog scale (EQ‐VAS) in this cross‐sectional study. Three regression models were estimated to determine the association between AN subtype (restrictive vs. binge/purge), duration of the eating disorder (ED), age (adolescents vs. adults), ED pathology (EDE‐Q), Body Mass Index (BMI), depressive symptoms (PHQ‐9), somatic complaints (PHQ‐15), anxiety (GAD‐7) and EQ‐VAS.

Results

The sample comprised 218 female AN patients (mean age = 23.3 years [SD = 8.2]; mean EQ‐VAS score = 53.4 [SD = 21.4]). A lower BMI, higher levels of depressive symptoms, and somatic complaints were significantly associated with lower EQ‐VAS scores.

Discussion

Findings of the present study suggest that BMI and comorbidity might be more relevant to HRQoL impairments in AN than age, diagnostic subtype, duration of the ED or current psychopathology. © 2016 Wiley Periodicals, Inc. (Int J Eat Disord 2016; 49:630–634)
Different pitcher shapes and trapping syndromes explain resource partitioning inNepenthesspecies
Authors: Gaume Laurence , Bazile Vincent , Huguin Maïlis , Bonhomme Vincent
Published: February 2016

Nepenthespitcher plants display interspecific diversity in pitcher form and diets. This species‐rich genus might be a conspicuous candidate for an adaptive radiation. However, the pitcher traits of different species have never been quantified in a comparative study, nor have their possible adaptations to the resources they exploit been tested. In this study, we compare the pitcher features and prey composition of the sevenNepenthestaxa that grow in the heath forest of Brunei (Borneo) and investigate whether these species display different trapping syndromes that target different prey. TheNepenthesspecies are shown to display species‐specific combinations of pitcher shapes, volumes, rewards, attraction and capture traits, and different degrees of ontogenetic pitcher dimorphism. The prey spectra also differ among plant species and between ontogenetic morphotypes in their combinations of ants, flying insects, termites, and noninsect guilds. According to a discriminant analysis, theNepenthesspecies collected at the same site differ significantly in prey abundance and composition at the level of order, showing niche segregation but with varying degrees of niche overlap according to pairwise species comparisons. Weakly carnivorous species are first characterized by an absence of attractive traits. Generalist carnivorous species have a sweet odor, a wide pitcher aperture, and an acidic pitcher fluid. Guild specializations are explained by different combinations of morpho‐functional traits. Ant captures increase with extrafloral nectar, fluid acidity, and slippery waxy walls. Termite captures increase with narrowness of pitchers, presence of a rim of edible trichomes, and symbiotic association with ants. The abundance of flying insects is primarily correlated with pitcher conicity, pitcher aperture diameter, and odor presence. Such species‐specific syndromes favoring resource partitioning may result from local character displacement by competition and/or previous adaptations to geographically distinct environments.
The role of local versus biogeographical processes in influencing diversity and body‐size variation in mammal assemblages
Authors: Lopez Luiz Carlos S. , Figueiredo Marcos S. L. , Fracasso Maria Paula de Aguiar , Mesquita Daniel Oliveira , Anjos Ulisses Umbelino , Grelle Carlos Eduardo Viveiros
Published: February 2016

Our objective was to estimate and analyze the body‐size distribution parameters of terrestrial mammal assemblages at different spatial scales, and to determine whether these parameters are controlled by local ecological processes or by larger‐scale ones. Based on 93 local assemblages, plus the complete mammal assemblage from three continents (Africa, North, and South America), we estimated three key distribution parameters (diversity/size slope, skewness, and modal size) and compared the values to those expected if size distributions are mainly controlled by local interactions. Mammal diversity decreased much faster as body size increased than predicted by fractal niche theory, both at continental and at local scales, with continental distributions showing steeper slopes than the localities within them. South America showed a steeper slope (after controlling for species diversity), compared to Africa and North America, at local and continental scales. We also found that skewness and modal body size can show strikingly different correlations with predictor variables, such as species richness and median size, depending on the use of untransformed versus log‐transformed data, due to changes in the distribution density generated by log‐transformation. The main differences in slope, skewness, and modal size between local and continental scales appear to arise from the same biogeographical process, where small‐sized species increase in diversity much faster (due to higher spatial turnover rates) than large‐sized species. This process, which can operate even in the absence of competitive saturation at local scales, generates continental assemblages with steeper slopes, smaller modal sizes, and higher right skewness (toward small‐sized species) compared to local communities. In addition, historical factors can also affect the size distribution slopes, which are significantly steeper, in South American mammal assemblages (probably due to stronger megafauna extinction events in South America) than those in North America and Africa.
Commensal A4 bacteria inhibit intestinal Th2‐cell responses through induction of dendritic cell TGF‐β production
Authors: Wu Wei , Liu Hou‐Pu , Chen Feidi , Liu Han , Cao Anthony T. , Yao Suxia , Sun Mingming , Evans‐Marin Heather L. , Zhao Ye , Zhao Qing , Duck L. Wayne , Elson Charles O. , Liu Zhanju , Cong Yingzi
Published: February 2016

It has been shown that while commensal bacteria promote Th1, Th17 and Treg cells in lamina propria (LP) in steady‐state conditions, they suppress mucosal Th2 cells. However, it is still unclear whether there are specific commensal organisms down‐regulating Th2 responses, and the mechanism involved. Here we demonstrate that commensal A4 bacteria, a member of the Lachnospiraceae family, which produce an immunodominant microbiota CBir1 antigen, inhibits LP Th2‐cell development. When transferred into the intestines of RAG−/− mice, CBir1‐specific T cells developed predominately towards Th1 cells and Th17 cells, but to a lesser extent into Th2 cells. The addition of A4 bacterial lysates to CD4+ T‐cell cultures inhibited production of IL‐4. A4 bacteria stimulated dendritic cell production of TGF‐β, and blockade of TGF‐β abrogated A4 bacteria inhibition of Th2‐cell development in vitro and in vivo. Collectively, our data show that A4 bacteria inhibit Th2‐cell differentiation by inducing dendritic cell production of TGF‐β.
Electrocatalytic Oxidation of Amines by Ni­(1,4,8,11‐tetraazacyclotetradecane)2+ Entrapped in Sol–Gel Electrodes
Authors: Burg Ariela , Shamir Dror , Apelbaum Lina , Albo Yael , Maimon Eric , Meyerstein Dan
Published: February 2016

Invited for the cover of this issue is Ariela Burg from the Sami Shamoon College of Engineering, Beer‐Sheva, Israel. The cover image shows a sol–gel electrode in which a nickel complex is entrapped. This system serves as an electrocatalyst for the oxidation of amines.
Toward efficient microaerobic processes using engineered Escherichia coli W3110 strains
Authors: Pablos Tania E. , Olivares Roberto , Sigala Juan Carlos , Ramírez Octavio T. , Lara Alvaro R.
Published: February 2016

Operational and economic constraints in large‐scale bioreactors often result in local or global microaerobic conditions, which lead to less efficient bioprocesses. Escherichia coli adapts to microaerobicity by activating fermentation pathways that accumulate acidic by‐products, in detriment of growth rate (μ) and biomass yield on glucose (YX/S). In this study, the metabolism of E. coli was modified to better cope with microaerobicity. For that purpose, genes coding for global regulators like carbon source responsive B protein and aerobic respiratory control A protein, or for fermentative pathways were inactivated. The performance of a wild‐type (W3110) and engineered E. coli strains was evaluated in batch cultures at constant low dissolved oxygen tension (3% air sat.). By combining the partial elimination of fermentation pathways and the expression of the Vitreoscilla hemoglobin (VHb), a 32% decrease on carbon waste as by‐products, 24 % increase on YX/S and 13% increase of μ were obtained. Flux balance analysis of the best strain estimated major differences in the fluxes through the pentose phosphate pathway and tricarboxylic acid cycle as consequence of VHb presence. Overall, our results show that E. coli can be genetically modified to overcome some of the disadvantages of microaerobic growth, which is potentially useful for better bioreactor scale‐up and operation.
Prediction of low‐rank coal pyrolysis behavior by chemical percolation devolatilization model
Authors: Liu Guangrui , Song Huijuan , Wu Jinhu
Published: February 2016

The chemical percolation devolatilization (CPD) model was proposed to predict the pyrolysis behavior of fast‐heated coal based on the chemical structure of low‐rank coal sample. The coal‐dependent chemical structure parameters were taken directly from solid state 13C nuclear magnetic resonance (NMR) analysis, with the exception of one empirical coefficient initial fraction of char bridges (c0). The Fourier transform infrared spectroscopic analysis was also employed to describe the pyrolysis characteristics of parent coal. The predictions of amount and characteristics of volatiles, tar and char from CPD model indicated that the crosslinking mechanism plays an important role for the pyrolysis of low‐rank coal. In order to deeply understand the structure and chemical bonds of coal sample, the average chemical structure of low‐rank coal was built by ACD/Labs software of ChemSketch. The 13C NMR spectrum of established average coal structure fitted well with that of parent coal sample. © 2016 American Institute of Chemical Engineers Environ Prog, 35: 1215–1220, 2016
Barley root hair growth and morphology in soil, sand, and water solution media and relationship with nickel toxicity
Authors: Lin Yanqing , Allen Herbert E. , Di Toro Dominic M.
Published: February 2016

Barley, Hordeum vulgare (Doyce), was grown in the 3 media of soil, hydroponic sand solution (sand), and hydroponic water solution (water) culture at the same environmental conditions for 4 d. Barley roots were scanned, and root morphology was analyzed. Plants grown in the 3 media had different root morphology and nickel (Ni) toxicity response. Root elongations and total root lengths followed the sequence soil > sand > water. Plants grown in water culture were more sensitive to Ni toxicity and had greater root hair length than those from soil and sand cultures, which increased root surface area. The unit root surface area as root surface area per centimeter of length of root followed the sequence water > sand > soil and was found to be related with root elongation. Including the unit root surface area, the difference in root elongation and 50% effective concentration were diminished, and percentage of root elongations can be improved with a root mean square error approximately 10% for plants grown in different media. Because the unit root surface area of plants in sand culture is closer to that in soil culture, the sand culture method, not water culture, is recommended for toxicity parameter estimation. Environ Toxicol Chem 2016;35:2125–2133. © 2016 SETAC
Identifying Android malware with system call co‐occurrence matrices
Authors: Xiao Xi , Xiao Xianni , Jiang Yong , Liu Xuejiao , Ye Runguo
Published: February 2016

With the popularity of Android devices, mobile malware in Android has became more prevalent. Malware causes lots of harm to users, such as stealing personal information and using too much battery or CPU. Detecting mobile malware is the main task in Android security. In this work, we use a dynamic analysis method to distinguish malware with system call sequences. At first, we track the system calls of applications under different events. Then two different feature models, the frequency vector and the co‐occurrence matrix, are employed to extract features from the system call sequence. Finally, we apply Adaptive Regularization Of Weight Vectors and other machine learning algorithms to identify Android malware based on the aforementioned two models, respectively. We evaluate our method with 1189 benign applications and 1227 malicious applications. The experiment results show that the co‐occurrence matrix can achieve a much better detection rate than the frequency vector. Our best detection rate is 97.7per cent with false positive rate being 1.34per cent, which is better than those of the existing methods. Copyright © 2016 John Wiley & Sons, Ltd.
The effect of aboveground biomass removal on soil macronutrient over time in Munesa Shashemane, Ethiopia
Authors: Madalcho Aklilu Bajigo
Published: February 2016

This study aims to compare the proportion of macronutrients in different parts of the aboveground biomass; and to estimate the amount of macronutrient loss from continuous farmlands (mechanized farm and traditional farm) and plantation stands (Cupresus lusitanica and Eucalyptus saligna) through harvesting. From 20 × 20 m2 sized sample plots, a representative samples were collected from leaf, branch and stem of the plantation stands. Macronutrient analyses were carried out for the samples taken from plantations and maize crops on continuous farmlands. All data collected were subjected to ANOVA using the general linear model of SAS 9.0 at P < 0.05. The results of macronutrient in aboveground biomass of maize in the continuous farm lands shows that, the grain component contained as much as 50% of N and 60% of P compared to leaf and stem. However, a high proportion of K, Ca, and Mg were found in the leaf and stem components. In the case of C. lusitanica, 64.4% N, 70% P, 68.4% K, 65.3% Ca, and 68.75% of Mg was found in the stem compared to the leaf and branch. In the E. saligna, the stem contained 22% N, 30% P, 11.8% K, 26.6% Ca, and 12.5% Mg; with the remaining proportion of each nutrient found in the leaf and branch. Based on the results, much of the nutrients can be removed through the leaf and stem removal in the continuous farmlands. Complete removal of the biomass with little residue returned to the soil, for long periods under plantation land use, may also lead to macronutrient depletion. Therefore, to minimize this effect, the aboveground biomass harvest should focus on grain only on the farmlands, and stem only on the plantations.
Protein tyrosine phosphatase 1B dephosphorylates PITX1 and regulates p120RasGAP in hepatocellular carcinoma
Authors: Tai Wei‐Tien , Chen Yao‐Li , Chu Pei‐Yi , Chen Li‐Ju , Hung Man‐Hsin , Shiau Chung‐Wai , Huang Jui‐Wen , Tsai Ming‐Hsien , Chen Kuen‐Feng
Published: February 2016

The effective therapeutic targets for hepatocellular carcinoma remain limited. Pituitary homeobox 1 (PITX1) functions as a tumor suppressor in hepatocarcinogenesis by regulating the expression level of Ras guanosine triphosphatase‐activating protein. Here, we report that protein tyrosine phosphatases 1B (PTP1B) directly dephosphorylated PITX1 at Y160, Y175, and Y179 to further weaken the protein stability of PITX. The PTP1B‐dependent decline of PITX1 reduced its transcriptional activity for p120RasGAP (RASA1), a Ras guanosine triphosphatase‐activating protein. Both silencing of PTP1B and PTP1B inhibitor up‐regulated the PITX1‐p120RasGAP axis through hyperphosphorylation of PITX1. Sorafenib, the first and only targeted drug approved for hepatocellular carcinoma, directly decreased PTP1B activity and promoted the expression of PITX1 and p120RasGAP by PITX1 hyperphosphorylation. Molecular docking also supported the potential interaction between PTP1B and sorafenib. PTP1B overexpression impaired the sensitivity of sorafenib in vitro and in vivo, implying that PTP1B has a significant effect on sorafenib‐induced apoptosis. In sorafenib‐treated tumor samples, we further found inhibition of PTP1B activity and up‐regulation of the PITX1‐p120RasGAP axis, suggesting that PTP1B inhibitor may be effective for the treatment of hepatocellular carcinoma. By immunohistochemical staining of hepatic tumor tissue from 155 patients, the expression of PTP1B was significantly in tumor parts higher than nontumor parts (P = 0.02). Furthermore, high expression of PTP1B was significantly associated with poor tumor differentiation (P = 0.031). Conclusion: PTP1B dephosphorylates PITX1 to weaken its protein stability and the transcriptional activity for p120RasGAP gene expression and acts as a determinant of the sorafenib‐mediated drug effect; targeting the PITX1‐p120RasGAP axis with a PTP1B inhibitor may provide a new therapy for patients with hepatocellular carcinoma. (Hepatology 2016;63:1528‐1543)
Persistent Effect of Vitamin D Supplementation on Musculoskeletal Parameters in Adolescents One Year After Trial Completion
Authors: Ghazal Nisrine , Al-Shaar Laila , Maalouf Joyce , Nabulsi Mona , Arabi Asma , Choucair Mahmoud , Tamim Hani , Mahfoud Ziad , El-Hajj Fuleihan Ghada
Published: February 2016

We showed a beneficial effect of vitamin D supplementation on musculoskeletal parameters in adolescent girls in a 1-year, randomized, double-blinded placebo-controlled trial (RCT). Our objective for this study was to investigate the residual effect of vitamin D supplementation on bone mineral content (BMC), bone mineral density (BMD), at the lumbar spine and hip, lean mass, and height, 1 year after trial completion. We performed post hoc analyses in 167 adolescents, 86 girls and 81 boys, age 13.9 ± 2 years, who received vitamin D or placebo during the trial, and continued into the follow-up trial. Musculoskeletal parameters were measured at baseline, 12 months (intervention), and 24 months (follow-up). ANOVA and t tests were used to compare results between the placebo group and the merged vitamin D arms (200 or 2000 IU/day), by gender. Baseline characteristics were comparable between treatment groups at entry into the extension. Girls who had received vitamin D during the trial, had significantly larger hip BMC increments compared to those assigned to placebo, at 24 months compared to study entry, but not 24 compared to 12 months, which persisted in adjusted analyses. There were no significant differences in bone mass changes between treatment groups in boys, at 24 months compared to 12 months or to baseline. The beneficial effect of vitamin D supplementation on hip bone mass, achieved in girls during the trial, persisted 1 year after trial completion. These net cumulative increments, 1 year after discontinuation of supplementation, may have important implications on optimizing peak bone mass accretion in adolescent girls. © 2016 American Society for Bone and Mineral Research.
Circadian Clock Regulates Bone Resorption in Mice
Authors: Xu Cheng , Ochi Hiroki , Fukuda Toru , Sato Shingo , Sunamura Satoko , Takarada Takeshi , Hinoi Eiichi , Okawa Atsushi , Takeda Shu
Published: February 2016

The circadian clock controls many behavioral and physiological processes beyond daily rhythms. Circadian dysfunction increases the risk of cancer, obesity, and cardiovascular and metabolic diseases. Although clinical studies have shown that bone resorption is controlled by circadian rhythm, as indicated by diurnal variations in bone resorption, the molecular mechanism of circadian clock–dependent bone resorption remains unknown. To clarify the role of circadian rhythm in bone resorption, aryl hydrocarbon receptor nuclear translocator-like (Bmal1), a prototype circadian gene, was knocked out specifically in osteoclasts. Osteoclast-specific Bmal1-knockout mice showed a high bone mass phenotype due to reduced osteoclast differentiation. A cell-based assay revealed that BMAL1 upregulated nuclear factor of activated T cells, cytoplasmic, calcineurin-dependent 1 (Nfatc1) transcription through its binding to an E-box element located on the Nfatc1 promoter in cooperation with circadian locomotor output cycles kaput (CLOCK), a heterodimer partner of BMAL1. Moreover, steroid receptor coactivator (SRC) family members were shown to interact with and upregulate BMAL1:CLOCK transcriptional activity. Collectively, these data suggest that bone resorption is controlled by osteoclastic BMAL1 through interactions with the SRC family and binding to the Nfatc1 promoter. © 2016 American Society for Bone and Mineral Research.
Cointegration modelling for empirical South American seasonal temperature forecasts
Authors: Turasie Alemtsehai A. , Coelho Caio A. S.
Published: February 2016

This study investigates an alternative modelling approach for empirical seasonal temperature forecasts over South America. Seasonal average temperatures are found to be non‐stationary at most parts of South America over the 1949–2012 period. Simple persistence and lagged regression methods have considerable correlation skill in forecasting next season temperature using previous season temperature as predictor. However, the presence of trends in both predictor and predictand temperature variables can affect correlation skill. Models that can account for non‐stationarity in these variables may do better in modelling and forecasting seasonal temperatures known to have trends. A novel method (cointegration), introduced here for empirical seasonal climate forecasting, is found to perform better than the traditional persistence and regression forecasts for places where the predictor and predictand temperatures have stochastic trends. Potential skill pairwise comparisons between temperature forecasts produced with cointegration and those produced using persistence and lagged regression have shown that the alternative cointegration method performs significantly better than the other two. One of the main reasons for the better performance of cointegration method is that the modelling procedure accounts for the existing non‐stationarity in the process, and thus enables the estimated model to predict out of the range as efficiently as possible. Overall, this method appears to be ideal for modelling and predicting climate under the current global warming scenario. This is because most of the climatic variables including temperature in particular cannot be assumed to be stationary through time under such warming scenario.
Si3N4 as a biomaterial and its tribo‐characterization under water lubrication
Authors: Özmen Yılmaz
Published: February 2016

Hip implant wear is recognised as the main cause of hip implant failure therefore has been widely investigated both experimentally and clinically, demonstrating the coexistence of abrasive, adhesive, fatigue and corrosive wear. Many clinical in vivo and bulk material wear rate data from published literature have been presented for non‐oxide ceramic implants. Several studies have shown that the coefficient of friction of self‐mated silicon nitride in water decreases from an initially high value to about 0.002 after a certain run‐in period. Since the worn surfaces become extremely smooth, the low friction is attributed to the initiation of hydrodynamic lubrication by a thin water film at the interface. The possibility of mixed lubrication, i.e. hydrodynamic lubrication by water and boundary lubrication due to the presence of colloidal silica on the wearing surfaces, has also been proposed.

Influence of load, speed and surface roughness on the duration of the run‐in period of silicon nitride under water lubrication was investigated in this study. The results confirmed that a low coefficient of friction is obtained following a run‐in period when a wear scar of sufficient size is developed to reduce the contact stress. The run‐in period, during which the coefficient of friction is fairly high, is shorter for smoother surfaces and at higher loads and speeds. The striations that appeared to be associated with the high‐friction spikes can be formed as a result of surface film breakdown. Although the results are consistent with the proposed mechanisms of hydrodynamic lubrication or mixed lubrication, it is proposed that the low‐friction behaviour may also be related to fundamental interactions between two hard and elastically deforming surfaces covered with hydrogen‐terminated oxide films. Copyright © 2016 John Wiley & Sons, Ltd.
Functionalized Polymers from α‐Hydroxyalkylated N‐Vinylcaprolactam
Authors: Schönenberg Lisa , Ritter Helmut
Published: February 2016

Hydroxyalkylation of N‐vinylcaprolactam (NVCL) in α‐position via ring‐opening reaction of propylene oxide and ε‐caprolactone, respectively, yields in precursors for multifunctional NVCL derivatives. Homo‐ and copolymers of hydroxyfunctionalized NVCL derivatives, synthesized by free radical mechanism, are further investigated regarding their thermoresponsive behavior. Esterification of hydroxypropylated NVCL derivative with methacrylic anhydride is carried out yielding a versatile bifunctional cross‐linker. Networks are obtained either via free radical polymerization of the cross‐linker or anionic polymerization of only the methacrylic function and subsequent polymer analogous cross‐linking of the vinylic side groups. The rheological behavior during and after curing is investigated by oscillatory rheology. Furthermore, N‐vinylcaprolactam anion is used as an initiator for the anionic ring‐opening polymerization of ε‐caprolactone. Copolymerization of poly(ε‐caprolactone) macromonomer with NVCL yields graft copolymers. A polymerizable thermotropic liquid crystalline (LC) derivative is prepared by coupling cholesteryl chloroformate to NVCL. The thermal behavior of LC derivative is investigated by differential scanning calorimetry and polarized light microscopy.

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Simulation Study on the Coil‐Globule Transition and Surface Adsorption of HP Chains
Authors: Wang Qi , Jiang Si‐Jia , Jia Wen , Luo Meng‐Bo
Published: February 2016

The coil‐globule transition of short hydrophobic‐polar (HP) chains, composed of 24 hydrophilic monomers and 24 polar monomers, in solution and on hydrophobic surface and the adsorption of the HP chain on hydrophobic surface are simulated. The coil‐globule transition point of the HP chain is dependent on sequence of chain but is roughly independent of the surface adsorption strength. Whereas the critical adsorption point of the HP chain is roughly independent of sequence. In addition, the lowest energy states can be obtained for the HP chain in solution or on surface by Monte Carlo simulated annealing method. Results show that the statistical conformation is strongly dependent on the intrachain H‐H attraction strength and the surface adsorption strength.

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New insights into FtsZ rearrangements during the cell division of Escherichia coli from single‐molecule localization microscopy of fixed cells
Authors: Vedyaykin Alexey D. , Vishnyakov Innokentii E. , Polinovskaya Vasilisa S. , Khodorkovskii Mikhail A. , Sabantsev Anton V.
Published: February 2016

FtsZ – a prokaryotic tubulin homolog – is one of the central components of bacterial division machinery. At the early stage of cytokinesis FtsZ forms the so‐called Z‐ring at mid‐cell that guides septum formation. Many approaches were used to resolve the structure of the Z‐ring, however, researchers are still far from consensus on this question. We utilized single‐molecule localization microscopy (SMLM) in combination with immunofluorescence staining to visualize FtsZ in Esherichia coli fixed cells that were grown under slow and fast growth conditions. This approach allowed us to obtain images of FtsZ structures at different stages of cell division and accurately measure Z‐ring dimensions. Analysis of these images demonstrated that Z‐ring thickness increases during constriction, starting at about 70 nm at the beginning of division and increasing by approximately 25% half‐way through constriction.
Impact of xanthohumol (a prenylated flavonoid from hops) on DNA stability and other health‐related biochemical parameters: Results of human intervention trials
Authors: Ferk Franziska , Mišík Miroslav , Nersesyan Armen , Pichler Christoph , Jäger Walter , Szekeres Thomas , Marculescu Rodrig , Poulsen Henrik E. , Henriksen Trine , Bono Roberto , Romanazzi Valeria , Al‐Serori Halh , Biendl Martin , Wagner Karl‐Heinz , Kundi Michael , Knasmüller Siegfried
Published: February 2016

Scope

Xanthohumol (XN) is a hop flavonoid found in beers and refreshment drinks. Results of in vitro and animal studies indicate that it causes beneficial health effects due to DNA protective, anti‐inflammatory, antioxidant, and phytoestrogenic properties. Aim of the present study was to find out if XN causes alterations of health‐related parameters in humans.

Methods and results

The effects of the flavonoid were investigated in a randomized crossover intervention trial (n = 22) in which the participants consumed a XN drink (12 mg XN/P/day). We monitored alterations of the DNA stability in single cell gel electrophoresis assays in lymphocytes and of several health‐related biomarkers. A decrease of oxidatively damaged purines and protection toward reactive oxygen species induced DNA damage was found after the consumption of the beverage; also the excretion of 8‐oxo‐7,8‐dihydro‐2′‐deoxyguanosine and 8‐oxo‐guanosine in urine was reduced. The assumption that the flavonoid causes DNA protection was confirmed in a randomized follow‐up study with pure XN (n = 10) with a parallel design. Other biochemical parameters reflecting the redox‐ and hormonal status and lipid‐ and glucose metabolism were not altered after the intervention.

Conclusion

Taken together, our data indicate that low doses of XN protect humans against oxidative DNA damage.
Two nonspecific lipid transfer proteins (nsLTPs) from tomato seeds are associated to severe symptoms of tomato‐allergic patients
Authors: Martín‐Pedraza Laura , González Miguel , Gómez Francisca , Blanca‐López Natalia , Garrido‐Arandia María , Rodríguez Rosalía , Torres María J. , Blanca Miguel , Villalba Mayte , Mayorga Cristobalina
Published: February 2016

Scope

Tomato has become one of the most consumed vegetables worldwide, but its intake is often accompanied by an increasing risk of inducing allergic symptoms. The aim of the work was the identification of new seed‐specific allergens associated with severe symptoms in patients allergic to this edible vegetable.

Methods and results

We used 22 sera from well‐defined tomato‐allergic patients. Tomato seed proteins were purified and analyzed for biochemical and immunological characterization. A mixture of two associated IgE‐binding nsLTPs was purified from tomato seeds. Both allergens, Sola l 7 and Sola l 6, displayed primary structure differences with respect to their counterpart, Sola l 3, from tomato pulp/peel. They retained the ability to bind IgE from 71.4% of patients with severe symptoms. The purified proteins induced positive basophil activation test and skin prick test, and displayed cross‐reactivity with homologous allergens from peanut and sunflower seeds, among others.

Conclusion

We herein described two novel allergens from tomato seeds that belong to the nonspecific lipid transfer protein family classes 1 and 2, respectively. This is the first work associating IgE reactivity to these proteins with severe symptoms of certain tomato‐allergic patients. Therefore, they are optimal candidates for clarifying the diagnosis of the tomato allergy.
Three‐dimensional MR spectroscopic imaging using adiabatic spin echo and hypergeometric dual‐band suppression for metabolic mapping over the entire brain
Authors: Esmaeili Morteza , Bathen Tone F. , Rosen Bruce R. , Andronesi Ovidiu C.
Published: February 2016

Purpose

Large lipid and water signals in MR spectroscopic imaging (MRSI) complicate brain metabolite quantification. In this study, we combined adiabatic hypergeometric dual‐band (HGDB) lipid and water suppression with gradient offset independent adiabatic (GOIA) spin echo to improve three‐dimensional (3D) MRSI of the entire brain.

Methods

3D MRSI was acquired at 3T with a 32‐channel coil. HGDB pulses were used before excitation and during echo time. A brain slab was selected with GOIA‐W(16,4) pulses, weighted phase encoded stack of spirals, and real‐time motion/shim correction. HGDB alone or in combination with OVS and MEGA (MEscher‐GArwood) was compared with OVS only and no suppression.

Results

The combined HGDB pulses suppressed lipids to 2%–3% of their full unsuppressed signal. The HGDB lipid suppression was on average 5 times better than OVS suppression. HGDB+MEGA provided 30% more suppression compared with a previously described HGDB+OVS scheme. The number of voxels with good metabolic fits was significantly larger in the HGDB data (91%–94%) compared with the OVS data (59%–80%).

Conclusion

HGDB pulses provided efficient lipid and water suppression for full brain 3D MRSI. The HGDB suppression is superior to traditional OVS, and it can be combined with adiabatic spin echo to provide a sequence that is robust to B1 inhomogeneity. Magn Reson Med 77:490–497, 2017. © 2016 International Society for Magnetic Resonance in Medicine