bluuebunny/crossref_metadata_2025 huggingface dataset:
A hepatocyte-specific transcriptional program driven by Rela and Stat3 exacerbates experimental colitis in mice by modulating bile synthesis
Authors: Singh Jyotsna , Sarkar Binayak , Yadav Mohit , Deka Alvina , Markandey Manasvini , Sanyal Priyadarshini , Nagarajan Perumal , Gaikward Nilesh , Ahuja Vineet , Mohanty Debasisa , Basak Soumen , Gokhale Rajesh S
Published: June 2024

Hepatic factors secreted by the liver promote homeostasis and are pivotal for maintaining the liver-gut axis. Bile acid metabolism is one such example wherein, bile acid synthesis occurs in the liver and its biotransformation happens in the intestine. Dysfunctional interactions between the liver and the intestine stimulate varied pathological outcomes through its bidirectional portal communication. Indeed, aberrant bile acid metabolism has been reported in inflammatory bowel disease (IBD). However, the molecular mechanisms underlying these crosstalks that perpetuate intestinal permeability and inflammation remain obscure. Here, we identify a novel hepatic gene program regulated by Rela and Stat3 that accentuates the inflammation in an acute experimental colitis model. Hepatocyte-specific ablation of Rela and Stat3 reduces the levels of primary bile acids in both the liver and the gut and shows a restricted colitogenic phenotype. On supplementation of chenodeoxycholic acid (CDCA), knock-out mice exhibit enhanced colitis-induced alterations. This study provides persuasive evidence for the development of multi-organ strategies for treating IBD and identifies a hepatocyte-specific
rela-stat3
network as a promising therapeutic target.
Untargeted Pixel-by-Pixel Imaging of Metabolite Ratio Pairs as a Novel Tool for Biomedical Discovery in Mass Spectrometry Imaging
Authors: Cheng Huiyong , Miller Dawson , Southwell Nneka , Porcari Paola , Fischer Joshua L , Taylor Isobel , Salbaum J Michael , Kappen Claudia , Hu Fenghua , Yang Cha , Keshari Kayvan R , Gross Steven S , D’Aurelio Marilena , Chen Qiuying
Published: June 2024

Mass spectrometry imaging (MSI) is a powerful technology used to define the spatial distribution and relative abundance of metabolites across tissue cryosections. While software packages exist for pixel-by-pixel individual metabolite and limited target pairs of ratio imaging, the research community lacks an easy computing and application tool that images any metabolite abundance ratio pairs. Importantly, recognition of correlated metabolite pairs may contribute to the discovery of unanticipated molecules in shared metabolic pathways. Here, we describe the development and implementation of an untargeted R package workflow for pixel-by-pixel ratio imaging of all metabolites detected in an MSI experiment. Considering untargeted MSI studies of murine brain and embryogenesis, we demonstrate that ratio imaging minimizes systematic data variation introduced by sample handling, markedly enhances spatial image contrast, and reveals previously unrecognized metabotype-distinct tissue regions. Furthermore, ratio imaging facilitates identification of novel regional biomarkers and provides anatomical information regarding spatial distribution of metabolite-linked biochemical pathways. The algorithm described herein is applicable to any MSI dataset containing spatial information for metabolites, peptides or proteins, offering a potent hypothesis generation tool to enhance knowledge obtained from current spatial metabolite profiling technologies.
PAbFold: Linear Antibody Epitope Prediction using AlphaFold2
Authors: DeRoo Jacob , Terry James S , Zhao Ning , Stasevich Timothy J , Snow Christopher D , Geiss Brian J
Published: June 2024

Defining the binding epitopes of antibodies is essential for understanding how they bind to their antigens and perform their molecular functions. However, while determining linear epitopes of monoclonal antibodies can be accomplished utilizing well-established empirical procedures, these approaches are generally labor- and time-intensive and costly. To take advantage of the recent advances in protein structure prediction algorithms available to the scientific community, we developed a calculation pipeline based on the localColabFold implementation of AlphaFold2 that can predict linear antibody epitopes by predicting the structure of the complex between antibody heavy and light chains and target peptide sequences derived from antigens. We found that this AlphaFold2 pipeline, which we call PAbFold, was able to accurately flag known epitope sequences for several well-known antibody targets (HA / Myc) when the target sequence was broken into small overlapping linear peptides and antibody complementarity determining regions (CDRs) were grafted onto several different antibody framework regions in the single-chain antibody fragment (scFv) format. To determine if this pipeline was able to identify the epitope of a novel antibody with no structural information publicly available, we determined the epitope of a novel anti-SARS-CoV-2 nucleocapsid targeted antibody using our method and then experimentally validated our computational results using peptide competition ELISA assays. These results indicate that the AlphaFold2-based PAbFold pipeline we developed is capable of accurately identifying linear antibody epitopes in a short time using just antibody and target protein sequences. This emergent capability of the method is sensitive to methodological details such as peptide length, AlphaFold2 neural network versions, and multiple-sequence alignment database. PAbFold is available at https://github.com/jbderoo/PAbFold.
Erdemli İnsan Algısı Ölçeği: Geçerlik ve Güvenilirlik Çalışması
Authors: Yiğitce Ayşe Nur , Şentürk Şener
Published: June 2024

Bu çalışmada bireylerin erdemli insan algılarını ölçebilmek amacıyla “Erdemli İnsan Algısı Ölçeği” geliştirmek amaçlanmıştır. Araştırma nicel araştırma modeli kullanılarak tasarlanmıştır. Çalışmada ölçek geliştirme süreçleri takip edilmiştir. Araştırma kolay ulaşılabilir örnekleme yöntemiyle belirlenen katılımcılar aracılığıyla 3 aşamada toplanmıştır. Bu aşamalardan birincisinde 50 madde olan taslak ölçek formu kullanılarak AFA yapılmış, analiz neticesinde ikinci taslak formun hazırlanmasına karar verilmiştir. İlk aşama için 314 katılımcıdan veri toplanmıştır, ikinci aşama için 238 ve son aşama için 330 katılımcıdan toplanan veriler ile ölçeğin geçerlik, güvenirlik ve madde analizleri gerçekleştirilmiştir. İkinci çalışma grubu üzerinde AFA gerçekleştirilmiş, analiz neticesinde 32 madde olan ikinci taslak ölçek formu 21 maddeye indirilmiştir. Son çalışma grubuyla DFA gerçekleştirilmiş 21 madde olan ölçek formu üzerinde yakınsak, ıraksak ve nomolojik geçerlikler hesaplanmıştır. Sonuç olarak ölçeğin nihai hali 21 madde ve 5 faktör olarak doğrulanmıştır.
Yapılan faktör analizleri neticesinde ilk aşama için ölçeğin toplam varyansın %57.17’sini, ikinci aşama için %54.50’sini açıkladığı tespit edilmiştir. DFA sonucunda uyum indeksleri χ2/sd değeri 2.13, RMSEA değeri .059, CFI değeri .90, GFI değeri .90 ve NFI değeri .83 olarak hesaplanmıştır; yakınsak geçerlik analizinde faktör yüklerinin genel olarak .50’nin üzerinde veya yakın bir değer aldıkları tespit edilmiş, faktörlere ilişkin AVE değerlerinin ise CR değerlerinden küçük olduğu tespit edilmiştir. Iraksak geçerlik analizinde faktörler arası korelasyonun .90’dan küçük olduğu ve AVE karakökü değerlerinin korelasyon katsayılarından büyük olduğu tespit edilmiştir. Korelasyon değerlerinin pozitif ve anlamlı olması ise nomolojik geçerliğin sağlandığını göstermiştir. Path diyagramıyla ölçeğin beşli faktör yapısı doğrulanmıştır. Güvenirlik analizleri neticesinde iç tutarlılık alpha katsayısı birinci aşama için .74, ikinci aşama için .80 ve son aşama için .83 olarak tespit edilmiştir. Alınan katsayılar neticesinde ölçeğin güvenilir olduğu sonucuna ulaşılmıştır. Sonuç olarak, ölçeğin geçerlik, güvenirlik ve madde analizlerine ilişkin bulgular ölçeğin erdemli insan algılarını belirlemek üzere geçerli, güvenilir ve kullanılabilir nitelikte olduğunu ortaya çıkartmaktadır.
Effect of a walking skill training program in patients who have undergone total hip arthroplasty: Followup one year after surgery
Authors: Heiberg Kristi Elisabeth , Bruun‐Olsen Vigdis , Ekeland Arne , Mengshoel Anne Marit
Published: December 2011

Objective

To investigate the effect of a 12‐session walking skill training program of weight‐bearing activities on physical functioning and self‐efficacy initiated in patients 3 months after total hip arthroplasty (THA).

Methods

Sixty‐eight patients with THA, 35 women and 33 men, with a mean age of 66 years (95% confidence interval [95% CI] 64, 67 years), were randomized to a training group (n = 35) or a control group without physiotherapy (n = 33). Assessments were performed before the intervention at 3 months (pretest), at 5 months (posttest 1), and at 12 months (posttest 2) after surgery. The primary outcome was the 6‐minute walk test (6MWT). The secondary outcomes were the stair climbing test (ST); figure‐of‐eight test; Index of Muscle Function (IMF); active hip range of motion (ROM) in flexion, extension, and abduction; Harris Hip Score (HHS); self‐efficacy; and Hip Dysfunction and Osteoarthritis Outcome Score.

Results

The training group had larger improvements than the control group at posttest 1 on the 6MWT with an adjusted mean difference of 52 meters (95% CI 29, 74 meters; P < 0.001) and on the ST of −1 second (95% CI −2, 0 seconds; P = 0.01).There were also improvements on the figure‐of‐eight test (P = 0.02), IMF (P = 0.001), active hip ROM in extension (P = 0.02), HHS (P = 0.05), and self‐efficacy (P = 0.04). The difference between the groups persisted at posttest 2 on the 6MWT of 52 meters (95% CI 24, 80 meters; P < 0.001) and on the ST of −1 second (95% CI −3, 0 seconds; P = 0.05).

Conclusion

The walking skill training program was effective, especially in improving walking both immediately after the intervention and 1 year after THA surgery.
Oligotriphenylene Nanofiber Sensors for Detection of Nitro‐Based Explosives
Authors: Liao Yao Zu , Strong Veronica , Wang Yue , Li Xin‐Gui , Wang Xia , Kaner Richard B.
Published: December 2011

Blue light‐emitting oligotriphenylene nanofibers are synthesized by oxidizing triphenylene using ferric chloride. By adjusting the monomer concentration, the acid used, and the temperature employed, the average diameter and length of the nanofibers can be readily tuned from 50 to 200 nm and 0.5 to 5 μm, respectively. Structural characterization, electrical conductivity, thermal stability, and fluorescence of oligotriphenylene, along with a proposed nanofiber formation mechanism, are presented. Both oligotriphenylene nanofiber dispersions and oligotriphenylene/polysulfone composite films are developed as fluorescent sensors for detecting traces of nitro‐based explosives including nitromethane, nitrobenzene, and 2,4,6‐trinitrophenol, as well as an electron‐deficient metal ion, Fe(III). The sensors exhibit much better selectivity and sensitivity compared to conventional sensors, with detection limits down to 1.0 nm with a detection range covering ∼4 orders of magnitude. The detection mechanism of the fluorescent sensors is also disscussed.
Human sinonasal explant system for testing cytotoxicity of intranasal agents
Authors: Lim Jae H. , Davis Greg E. , Rue Tessa C. , Storm Daniel R.
Published: December 2011

Background:

Intranasal agents play a critical role in the management of sinonasal disorders. There are ongoing efforts to develop new intranasal medications to combat sinonasal disease. Some intranasal agents, however, can have cytotoxic effects on human sinonasal tissue. In order to facilitate safe drug discovery, we developed a simple and reliable in vitro screening assay using human sinonasal explants to measure the cytotoxic profiles of intranasal agents.

Methods:

We obtained sinonasal tissues from several regions of the nasal cavity from 12 patients undergoing endoscopic sinonasal surgery. These tissues were cultured on polytetrafluoroethylene membrane in serum‐free growth medium. We determined the biochemical properties of these explants by measuring extracellular lactate dehydrogenase (LDH) levels and performing histological analyses over a period of 1 to 2 weeks. We then examined the cytotoxic profiles of 13 intranasal agents by measuring extracellular LDH levels using the human sinonasal explant system.

Results:

Sinonasal explants exhibited a rapid reduction in extracellular LDH levels indicating stabilization in the culture environment within 2 days. Histological analysis showed maintenance of good cellular architecture for up to 2 weeks. The explants displayed intact epithelium and expressed βIII‐tubulin and Ki‐67. Of the 13 tested intranasal agents, 1% zinc sulfate (ZnSO4), 5% ZnSO4, and Zicam application were cytotoxic.

Conclusion:

Based on the unique biochemical properties of the human nasal explant culture system, we developed a simple and reliable in vitro screening assay to determine the cytotoxic profiles of various intranasal agents by examining extracellular LDH levels and histopathology. © 2011 ARS‐AAOA, LLC.
Using carbon black nanoparticles to dye the cationic‐modified cotton fabrics
Authors: Wang Chaoxia , Zhang Xia , Lv Fangbing , Peng Liyuan
Published: December 2011

Carbon black (CB) aqueous dispersion was prepared and used to dye the cationic‐modified cotton fabrics through exhaust dyeing process. The effects of CB concentration, CB nanoparticles size, dyeing bath pH, dyeing time and dyeing temperature were investigated. The color yields of dyed fabrics were evaluated on Kubelka‐Munk value K/S. The surface morphologies of cationic modified and nonmodified cotton fabrics were measured by video microscope. The fabrics presented 18.9 of the color yield with the dyeing conditions: the dyeing solution contained 2% o.w.f. CB and dyeing at 80°C for 30 min with pH 13 using a 50 : 1 liquor ratio. The images of the video microscope demonstrated a clear surface profile for the cationic‐modified cotton fabrics dyed with smaller CB particle size solutions. These results indicated that CB nanoparticles were suitable for dyeing the cotton fabrics. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Oxidation and crosslinking processes during thermal aging of low‐density polyethylene films
Authors: Chabira Salem F. , Sebaa Mohamed , G'sell Christian
Published: December 2011

This work analyzes the influence of thermal degradation on the microstructure and the mechanical properties of low‐density polyethylene subjected to aging at 70°C in the dark for times up to 21 months. It is found that the polymer shows a gradual increase of its elastic modulus and a dramatic reduction of its ductility, due to secondary crystallization. Infrared spectroscopy (FTIR) reveals the autoaccelerated oxidation of the polymer after 5 months aging. It is observed that the unsaturated vinylidene groups initially present in the material are gradually overridden by vinyl groups and, eventually, by t‐vinylene groups. Nuclear magnetic resonance (13C NMR) shows that the initial butyl chain branches are progressively completed by shorter ramifications, namely ethyl branches. These results are discussed in term of macromolecular mechanisms: (i) oxidation, (ii) chain scission, and (iii) crosslinking. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Generalized magneto‐thermoelastic medium with variable material properties subjected to ramp‐type heating
Authors: Youssef Hamdy M. , El‐Bary A. A.
Published: December 2011

The equations of magneto‐generalized thermoelasticity with one relaxation time with variable electrical and thermal conductivity for one‐dimensional problems are cast into a matrix form using the state–space approach and Laplace transform techniques. The resulting formulation is applied to a problem of a half space where the bounded plane is subjected to a ramp‐type heating and a traction free. This takes place when a constant magnetic field permeates the medium in the absence of an external electric field. The inversion of the Laplace transform is carried out using a numerical approach. Numerical results for the temperature, the displacement, and the stress distributions are given and illustrated graphically. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Effect of the electron beam irradiation on the properties of epoxidized natural rubber (ENR 50) compatibilized linear low‐density polyethylene/soya powder blends
Authors: Sam S. T. , Ismail H. , Ahmad Z. , Ratnam C. T.
Published: December 2011

Linear low‐density polyethylene/soya powder blends were prepared by using an internal mixer at 150°C. The soya powder content ranged from 5 to 40 wt %. Epoxidized natural rubber with 50 mol % epoxidation (ENR 50) was added as a compatibilizer. The blends were irradiated by electron beam (EB) at a constant dose of 30 kGy. The changes in gel fraction, tensile properties, morphological and thermal properties of the samples were investigated. The gel content increased after EB irradiation. However, the increment of gel content was hindered by increasing soya powder content. The tensile strength and Young's modulus of the blends were increased by EB whereas the elongation at break decreased. The tensile fracture surface also support the reduction of elongation at break by EB irradiation. Further analysis on the irradiated blends using Fourier transform infrared spectra indicated an increase of oxygenated product after undergoing EB irradiation. The differential scanning calorimetry result indicated that the melting temperature of the blends decreased after EB irradiation whereas the crystallinity increased. EB irradiation also enhanced the thermal stability of the blends as indicated by thermogravimetric analysis. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
The remote sensing of mental stress from the electromagnetic reflection coefficient of human skin in the sub‐THz range
Authors: Safrai Eli , Ishai Paul Ben , Caduff Andreas , Puzenko Alexander , Polsman Alexander , Agranat Aharon J. , Feldman Yuri
Published: December 2011

Recent work has demonstrated that the reflection coefficient of human skin in the frequency range from 95 to 110 GHz (W band) mirrors the temporal relaxation of stress induced by physical exercise. In this work, we extend these findings to show that in the event of a subtle trigger to stress, such as mental activity, a similar picture of response emerges. Furthermore, the findings are extended to cover not only the W band (75–110 GHz), but also the frequency band from 110 to 170 GHz (D band). We demonstrate that mental stress, induced by the Stroop effect and recorded by the galvanic skin response (GSR), can be correlated to the reflection coefficient in the aforementioned frequency bands. Intriguingly, a light physical stress caused by repeated hand gripping clearly showed an elevated stress level in the GSR signal, but was largely unnoted in the reflection coefficient in the D band. The implication of this observation requires further validation. Bioelectromagnetics 33:375–382, 2012. © 2011 Wiley Periodicals, Inc.
The chemical formula of a magnetotactic bacterium
Authors: Naresh Mohit , Das Sayoni , Mishra Prashant , Mittal Aditya
Published: December 2011

Elucidation of the chemical logic of life is one of the grand challenges in biology, and essential to the progress of the upcoming field of synthetic biology. Treatment of microbial cells explicitly as a “chemical” species in controlled reaction (growth) environments has allowed fascinating discoveries of elemental formulae of a few species that have guided the modern views on compositions of a living cell. Application of mass and energy balances on living cells has proved to be useful in modeling of bioengineering systems, particularly in deriving optimized media compositions for growing microorganisms to maximize yields of desired bio‐derived products by regulating intra‐cellular metabolic networks. In this work, application of elemental mass balance during growth of Magnetospirillum gryphiswaldense in bioreactors has resulted in the discovery of the chemical formula of the magnetotactic bacterium. By developing a stoichiometric equation characterizing the formation of a magnetotactic bacterial cell, coupled with rigorous experimental measurements and robust calculations, we report the elemental formula of M. gryphiswaldense cell as ${\rm CH}_{{\rm 2}{\rm .06}} {\rm O}_{{\rm 0}{\rm .13}} {\rm N}_{{\rm 0}{\rm .28}} {\rm Fe}_{{\rm 1}{\rm .74} \times {\rm 10}^{- {\rm 3}} } $. Remarkably, we find that iron metabolism during growth of this magnetotactic bacterium is much more correlated individually with carbon and nitrogen, compared to carbon and nitrogen with each other, indicating that iron serves more as a nutrient during bacterial growth rather than just a mineral. Magnetotactic bacteria have not only invoked some interest in the field of astrobiology for the last two decades, but are also prokaryotes having the unique ability of synthesizing membrane bound intracellular organelles. Our findings on these unique prokaryotes are a strong addition to the limited repertoire, of elemental compositions of living cells, aimed at exploring the chemical logic of life. Biotechnol. Bioeng. 2012; 109:1205–1216. © 2011 Wiley Periodicals, Inc.
Fabrication of hierarchical hybrid structures using bio‐enabled layer‐by‐layer self‐assembly
Authors: Hnilova Marketa , Karaca Banu Taktak , Park James , Jia Carol , Wilson Brandon R. , Sarikaya Mehmet , Tamerler Candan
Published: December 2011

Development of versatile and flexible assembly systems for fabrication of functional hybrid nanomaterials with well‐defined hierarchical and spatial organization is of a significant importance in practical nanobiotechnology applications. Here we demonstrate a bio‐enabled self‐assembly technique for fabrication of multi‐layered protein and nanometallic assemblies utilizing a modular gold‐binding (AuBP1) fusion tag. To accomplish the bottom‐up assembly we first genetically fused the AuBP1 peptide sequence to the C′‐terminus of maltose‐binding protein (MBP) using two different linkers to produce MBP‐AuBP1 hetero‐functional constructs. Using various spectroscopic techniques, surface plasmon resonance (SPR) and localized surface plasmon resonance (LSPR), we verified the exceptional binding and self‐assembly characteristics of AuBP1 peptide. The AuBP1 peptide tag can direct the organization of recombinant MBP protein on various gold surfaces through an efficient control of the organic–inorganic interface at the molecular level. Furthermore using a combination of soft‐lithography, self‐assembly techniques and advanced AuBP1 peptide tag technology, we produced spatially and hierarchically controlled protein multi‐layered assemblies on gold nanoparticle arrays with high molecular packing density and pattering efficiency in simple, reproducible steps. This model system offers layer‐by‐layer assembly capability based on specific AuBP1 peptide tag and constitutes novel biological routes for biofabrication of various protein arrays, plasmon‐active nanometallic assemblies and devices with controlled organization, packing density and architecture. Biotechnol. Bioeng. 2012; 109:1120–1130. © 2011 Wiley Periodicals, Inc.
Alkoxy‐1,3,5‐triazapentadien(e/ato) Copper(II) Complexes: Template Formation and Applications for the Preparation of Pyrimidines and as Catalysts for Oxidation of Alcohols to Carbonyl Products
Authors: Kopylovich Maximilian N. , Karabach Yauhen Yu. , Guedes da Silva M. Fátima C. , Figiel Paweł J. , Lasri Jamal , Pombeiro Armando J. L.
Published: December 2011

Template combination of copper acetate (Cu(AcO)2⋅H2O) with sodium dicyanamide (NaN(C≡N)2, 2 equiv) or cyanoguanidine (N≡CNHC(=NH)NH2, 2 equiv) and an alcohol ROH (used also as solvent) leads to the neutral copper(II)–(2,4‐alkoxy‐1,3,5‐triazapentadienato) complexes [Cu{NHC(OR)NC(OR)NH}2] (R=Me (1), Et (2), nPr (3), iPr (4), CH2CH2OCH3 (5)) or cationic copper(II)–(2‐alkoxy‐4‐amino‐1,3,5‐triazapentadiene) complexes [Cu{NHC(OR)NHC(NH2)NH}2](AcO)2 (R=Me (6), Et (7), nPr (8), nBu (9), CH2CH2OCH3 (10)), respectively. Several intermediates of this reaction were isolated and a pathway was proposed. The deprotonation of 6–10 with NaOH allows their transformation to the corresponding neutral triazapentadienates [Cu{NHC(OR)NC(NH2)NH}2] 11–15. Reaction of 11, 12 or 15 with acetyl acetone (MeC(O)CH2C(O)Me) leads to liberation of the corresponding pyrimidines NC(Me)CHC(Me)NCNHC(NH)OR, whereas the same treatment of the cationic complexes 6, 7 or 10 allows the corresponding metal‐free triazapentadiene salts {NH2C(OR)NC(NH2)NH2}(OAc) to be isolated. The alkoxy‐1,3,5‐triazapentadiene/ato copper(II) complexes have been applied as efficient catalysts for the TEMPO radical‐mediated mild aerobic oxidation of alcohols to the corresponding aldehydes (molar yields of aldehydes of up to 100 % with >99 % selectivity) and for the solvent‐free microwave‐assisted synthesis of ketones from secondary alcohols with tert‐butylhydroperoxide as oxidant (yields of up to 97 %, turnover numbers of up to 485 and turnover frequencies of up to 1170 h−1).
Constructing Single‐Chain Magnets by Supramolecular π–π Stacking and Spin Canting: A Case Study on Manganese(III) Corroles
Authors: Ding Mei , Wang Bingwu , Wang Zheming , Zhang Junlong , Fuhr Olaf , Fenske Dieter , Gao Song
Published: December 2011

A single‐chain magnet (SCM) was constructed from manganese(III) 5,10,15‐tris(pentafluorophenyl)corrole complex [MnIII(tpfc)] through supramolecular π–π stacking without bridging ligands. In the crystal structures, [Mn(tpfc)] molecules crystallized from different solvents, such as methanol, ethyl acetate, and ethanol, exhibit different molecular orientations and intermolecular π–π interaction or weak Mn⋅⋅⋅O interaction to form a supramolecular one‐dimensional motif or dimer. These three complexes show very different magnetic behaviors at low temperature. Methanol solvate 1 shows obvious frequency dependence of out‐of‐phase alternating‐current magnetic susceptibility below 2 K and a magnetization hysteresis loop with a coercive field of 400 Oe at 0.5 K. It is the first example of spin‐canted supramolecular single‐chain magnet due to weak π–π stacking interaction. By fitting the susceptibility data χMT (20–300 K) of 1 with the spin Hamiltonian expression ${\overrightarrow{H}}$=−2J${{{}\mathrel{\mathop{\sum{}}\limits^{n- 1}\limits_{i=1}}{}}}$${\overrightarrow{S}}$Ai${\overrightarrow{S}}$Ai+1+D${{{}\mathrel{\mathop{\sum{}}\limits_{i}}{}}}$${\overrightarrow{S}}$iZ2, the intrachain magnetic coupling parameter transmitted by π–π interaction of −0.31 cm−1 and zero field splitting parameter D of −2.59 cm−1 are obtained. Ethyl acetate solvate 2 behaves as an antiferromagnetic chain without ordering or slow magnetic relaxation down to 0.5 K. The magnetic susceptibility data χMT (20–300 K) of 2 was fitted by assuming the spin Hamiltonian ${\overrightarrow{H}}$=−2J${{{}\mathrel{\mathop{\sum{}}\limits^{n- 1}\limits_{i=1}}{}}}$${\overrightarrow{S}}$Ai${\overrightarrow{S}}$Ai+1, and the intrachain antiferromagnetic coupling constant of −0.07 cm−1 is much weaker than that of 1. Ethanol solvate 3 with a dimer motif shows field‐induced single‐molecule magnet like behavior below 2.5 K. The exchange coupling constant J within the dimer propagated by π–π interaction is −0.14 cm−1 by fitting the susceptibility data χMT (20–300 K) with the spin Hamiltonian ${\overrightarrow{H}}$=−2J${\overrightarrow{S}}$A${\overrightarrow{S}}$B+β(${\overrightarrow{S}}$AgA+${\overrightarrow{S}}$BgB)H. The present studies open a new way to construct SCMs from anisotropic magnetic single‐ion units through weak intermolecular interactions in the absence of bridging ligands.
Synthesis of Dendritic β‐Diketones and Their Application in Copper‐Catalyzed Diaryl Ether Formation
Authors: Keller Michel , Ianchuk Mykhailo , Ladeira Sonia , Taillefer Marc , Caminade Anne‐Marie , Majoral Jean‐Pierre , Ouali Armelle
Published: December 2011

Phosphorus‐based dendrimers decorated with β‐diketones were prepared and fully characterized. These macromolecules, which are the first examples of multivalent dendrimeric β‐diketones, were tested as ligands for copper in O‐arylations of 3,5‐dimethylphenol by aryl bromides. Although no dendrimer effect was observed, we were able to highlight a very efficient catalytic system that involved a monomeric β‐diketone as the ligand. The proposed conditions are very competitive in terms of catalyst and base loading as the C–O coupling can be efficiently performed by using low amounts of copper precursor (1 mol‐% instead of 5–10 mol‐%), diketone (4 mol‐% instead of 25–80 mol‐%), and base (1.2 equiv. of cesium carbonate instead of 2 or more). Moreover, the absence of the dendrimer effect is explained by the decomposition of the dendrimer under the reaction conditions, which led to the release of the peripheral diketone moieties.
Binding Survey of Ionizable Calix[4]‐1,2‐crown‐3 Nano‐baskets by Differential Pulse Voltammetry
Authors: Mokhtari Bahram , Pourabdollah Kobra
Published: December 2011

Three nano‐baskets of p‐tert‐butylcalix[4]arene‐1,2‐crown‐3 were synthesized and their binding abilities towards alkali and alkaline earth metals as well as some lanthanides were studied using differential pulse voltammetry. The novelty of this study was the investigation of macrocyclic complexes by voltammetric behaviors of two acidic moieties in each scaffold. Their voltammetric behaviors were closely related to the complex formation by entrapment of cation into crown ether cavity and ion‐dipole interaction between cation and acidic moieties in calixcrowns. The results revealed that the sulfur atom in the crown ring as well as the position of crown‐3 ether in 1,2‐alternate instead of cone conformer changed the binding ability of the scaffold to more cations.
Simultaneous determination of nitrite and nitrate in human plasma by on‐capillary preconcentration with field‐amplified sample stacking
Authors: Wang Xu , Masschelein Evi , Hespel Peter , Adams Erwin , Van Schepdael Ann
Published: December 2011

A simple method for the determination of nitrite and nitrate in human plasma has been developed using CZE with minimal sample preparation. Field‐amplified sample stacking (FASS) was used to achieve submicromolar detection by dilution of the plasma sample with deionized water. In CZE, the separation of nitrite and nitrate was achieved within 10 min without adding EOF modifier. The optimal condition was achieved with 50 mM phosphate buffer at pH 9.3. The ninefold diluted plasma samples were injected hydrodynamically for 40 s into a 60 cm×75 μm id uncoated fused‐silica capillary. The separation voltage was 20 kV (negative potential) and UV detection was performed at 214 nm. The linearity curves for nitrite and nitrate were obtained by the standard addition method. The estimated LODs for nitrite and nitrate in ninefold diluted plasma sample were 0.05 and 0.07 μM, respectively. The LODs for nitrite and nitrate in original plasma samples were 0.45 and 0.63 μM. The intra‐ and inter‐day precisions for both analytes were <2.6% and the recovery ranged between 92.3 and 113.3%. It was found that nitrite was more stable than nitrate in the plasma after the sample preparation. This proposed method was applied to a number of human plasma samples and the measured nitrite and nitrate concentrations in human plasma were consistent with the literature ranges.
Beyond being an evaluator: The multiplicity of roles of the internal evaluator
Authors: Volkov Boris B.
Published: December 2011

The chapter explores critical roles of internal evaluators in contemporary organizational settings. The need is highlighted for an expanded, reconfigured, unorthodox set of roles and styles of work to meet the needs of the emerging learning organizations effectively. A discussion of major categories of internal evaluator roles emerged from the analysis of the evaluation literature and other sources suggests new directions for how internal evaluation is conceptualized and practiced. Systematic promoting and advancing positive change, evaluation capacity building, decision making, learning, and evaluative thinking in organizations are seen as part of the harmonized internal evaluator role. © Wiley Periodicals, Inc., and the American Evaluation Association.
A Geological History of the Turkana Basin
Authors: Feibel Craig S.
Published: December 2011

The Turkana Basin preserves a long and detailed record of biotic evolution, cultural development, and rift valley geology in its sedimentary strata. Before the formation of the modern basin, Cretaceous fluvial systems, Paleogene lakes, and Oligo‐Miocene volcano‐sedimentary sequences left fossil‐bearing strata in the region. These deposits were in part related to an early system of rift basins that stretched from Sudan to the Indian Ocean. The present‐day basin has its origins in Pliocene tectonic developments of the modern rift, with subsidence making room for more than one kilometer of Plio‐Pleistocene strata. Much of this sequence belongs to the Omo Group, richly fossiliferous sediments associated with the ancestral Omo River and its tributaries. Modern Lake Turkana has a record stretching back more than 200 thousand years, with earlier lake phases throughout the Plio‐Pleistocene. The geologic history of the basin is one of dynamic landscapes responding to environmental influences, including tectonics, volcanic activity and climate. © Wiley Periodicals, Inc.
Restoration of C/EBPα in dedifferentiated liposarcoma induces G2/M cell cycle arrest and apoptosis
Authors: Wu Yuhsin V. , Okada Tomoyo , DeCarolis Penelope , Socci Nicholas , O'Connor Rachael , Geha Rula C. , Joy Somberg C. , Antonescu Cristina , Singer Samuel
Published: December 2011

Well‐differentiated liposarcoma (WDLS) and dedifferentiated liposarcoma (DDLS) represent the most common biological group of liposarcoma, and there is a pressing need to develop targeted therapies for patients with advanced disease. To identify potential therapeutic targets, we sought to identify differences in the adipogenic pathways between DDLS, WDLS, and normal adipose tissue. In a microarray analysis of DDLS (n = 84), WDLS (n = 79), and normal fat (n = 23), C/EBPα, a transcription factor involved in cell cycle regulation and differentiation, was underexpressed in DDLS when compared to both WDLS and normal fat (15.2‐ and 27.8‐fold, respectively). In normal adipose‐derived stem cells, C/EBPα expression was strongly induced when cells were cultured in differentiation media, but in three DDLS cell lines, this induction was nearly absent. We restored C/EBPα expression in one of the cell lines (DDLS8817) by transfection of an inducible C/EBPα expression vector. Inducing C/EBPα expression reduced proliferation and caused cells to accumulate in G2/M. Under differentiation conditions, the cell proliferation was reduced further, and 66% of the DDLS cells containing the inducible C/EBPα expression vector underwent apoptosis as demonstrated by annexin V staining. These cells in differentiation conditions expressed early adipocyte‐specific mRNAs such as LPL and FABP4, but they failed to accumulate intracellular lipid droplets, a characteristic of mature adipocytes. These results demonstrate that loss of C/EBPα is an important factor in suppressing apoptosis and maintaining the dedifferentiated state in DDLS. Restoring C/EBPα may be a useful therapeutic approach for DDLS. © 2011 Wiley Periodicals, Inc.
Multi‐model, multi‐sensor estimates of global evapotranspiration: climatology, uncertainties and trends
Authors: Vinukollu Raghuveer K. , Meynadier Remi , Sheffield Justin , Wood Eric F.
Published: December 2011

Estimating evapotranspiration (ET) at continental to global scales is central to understanding the partitioning of energy and water at the earth's surface and the feedbacks with the atmosphere and biosphere, especially in the context of climate change. Recent evaluations of global estimates from remote sensing, upscaled observations, land surface models and atmospheric reanalyses indicate large uncertainty across the datasets of the order of 50% of the global annual mean value. In this paper, we explore the uncertainties in global land ET estimates using three process‐based ET models and a set of remote sensing and observational based radiation and meteorological forcing datasets. Input forcings were obtained from International Satellite Cloud Climatology Project (ISCCP) and Surface Radiation Budget (SRB). The three process‐based ET models are: a surface energy balance method (SEBS), a revised Penman–Monteith (PM) model, and a modified Priestley–Taylor model. Evaluations of the radiation products from ISCCP and SRB show large differences in the components of surface radiation, and temporal inconsistencies that relate to changes in satellite sensors and retrieval algorithms. In particular, step changes in the ISCCP surface temperature and humidity data lead to spurious increases in downward and upward longwave radiation that contributes to a step change in net radiation, and the ISCCP data are not used further. An ensemble of global estimates of land surface ET are generated at daily time scale and 0.5 degree spatial resolution for 1984–2007 using two SRB radiation products (SRB and SRBqc) and the three models. Uncertainty in ET from the models is much larger than the uncertainty from the radiation data. The largest uncertainties relative to the mean annual ET are in transition zones between dry and humid regions and monsoon regions. Comparisons with previous studies and an inferred estimate of ET from long‐term inferred ET indicate that the ensemble mean value is reasonable, but generally biased high globally. Long‐term changes over 1984–2007 indicate a slight increase over 1984–1998 and decline thereafter, although uncertainties in the forcing radiation data and lack of direct linkage with soil moisture limitations in the models prevents attribution of these changes. Copyright © 2011 John Wiley & Sons, Ltd.
Potential for water salvage by removal of non‐native woody vegetation from dryland river systems
Authors: Doody Tanya M. , Nagler Pamela L. , Glenn Edward P. , Moore Georgianne W. , Morino Kiyomi , Hultine Kevin R. , Benyon Richard G.
Published: December 2011

Globally, expansion of non‐native woody vegetation across floodplains has raised concern of increased evapotranspiration (ET) water loss with consequent reduced river flows and groundwater supplies. Water salvage programs, established to meet water supply demands by removing introduced species, show little documented evidence of program effectiveness. We use two case studies in the USA and Australia to illustrate factors that contribute to water salvage feasibility for a given ecological setting. In the USA, saltcedar (Tamarix spp.) has become widespread on western rivers, with water salvage programs attempted over a 50‐year period. Some studies document riparian transpiration or ET reduction after saltcedar removal, but detectable increases in river base flow are not conclusively shown. Furthermore, measurements of riparian vegetation ET in natural settings show saltcedar ET overlaps the range measured for native riparian species, thereby constraining the possibility of water salvage by replacing saltcedar with native vegetation. In Australia, introduced willows (Salix spp.) have become widespread in riparian systems in the Murray–Darling Basin. Although large‐scale removal projects have been undertaken, no attempts have been made to quantify increases in base flows. Recent studies of ET indicate that willows growing in permanently inundated stream beds have high transpiration rates, indicating water savings could be achieved from removal. In contrast, native Eucalyptus trees and willows growing on stream banks show similar ET rates with no net water salvage from replacing willows with native trees. We conclude that water salvage feasibility is highly dependent on the ecohydrological setting in which the non‐native trees occur. We provide an overview of conditions favorable to water salvage. Copyright © 2011 John Wiley & Sons, Ltd.
A Cluster–Resonance Criterion for Al‐TM Quasicrystal Compositions
Authors: Chen Hua , Qiang Jianbing , Wang Qing , Wang Yingmin , Dong Chuang
Published: December 2011

Compositions of binary Al‐TM (TM=Cr to Ni) quasicrystals are interpreted with a unified cluster formula [icosahedron](glue)1 using the newly developed cluster–resonance model and the e/a formalism. The icosahedra are chosen from the corresponding approximants by considering large radial atomic density, high degree of isolation, and narrow distribution of the shell atoms. Icosahedral quasicrystals are expressed by an icosahedron plus one averaged icosahedron atom as the glue atom [icosahedron](icosahedron/13)1, characterized by e/a ∼1.83–1.85, while decagonal quasicrystals are expressed by an icosahedron plus one TM atom, with e/a ∼1.71–1.78. The total electrons accommodated in unit cluster formulas of different Al‐TM quasicrystals have the same value approaching 24, which implies that the cluster formulas are both chemical and electronic structural units.
Electrons in Quasicrystals
Authors: Grimm Uwe
Published: December 2011

Quasicrystals, discovered by Dan Shechtman in 1982, provide unique materials with long‐range aperiodic order. Their electronic structure and the electronic transport in quasicrystalline alloys has been a focus of research, motivated by trying to understand the formation and stability of quasicrystals, and their pronounced transport anomalies. This brief review on the motion of electrons concentrates on one perspective of this problem. It focuses on results obtained for simple models which capture the essence of the aperiodic order, rather than on results which attempt a realistic description of quasicrystalline alloys by employing empirical interaction potentials.
Diffusion‐weighted MRI of fatty liver
Authors: Poyraz Ahmet K. , Onur Mehmet R. , Kocakoç Ercan , Oğur Erkin
Published: December 2011

Purpose:

To investigate the effect of fat infiltration on the apparent diffusion coefficient (ADC) of liver, and assess the relationship between ADC and hepatic fat fraction (HFF).

Materials and Methods:

MRI scans of 120 consecutive patients were included in this retrospective study. Of these, 42 patients were included in the fatty liver group and 78 in the control group. ADC values were measured from a pair of diffusion‐weighted (DW) images (b = 0 mm2/s and 1000 mm2/s). HFFs were measured using T1W GRE dual‐echo images. The difference between the ADCs of the two groups was assessed with the t‐test. The relationship between HFF and ADC was determined using linear regression analysis and the Pearson correlation coefficient (r).

Results:

Mean HFFs were 0.85 ± 2.86 and 13.67 ± 8.62 in the control and fatty liver groups, respectively. The mean ADC of fatty liver group 1.20 ± 0.22 × 10−3 mm2/s was significantly lower than that of the control group 1.32 ± 0.23 × 10−3 mm2/s (P = 0.02). Linear regression analysis revealed an inverse relationship between ADC and HFF (r = −0.39, P < 0.0001).

Conclusion:

ADC significantly decreases in patients with >5% HFF, and ADC and HFF exhibit an inverse relationship. J. Magn. Reson. Imaging 2012;35:1109‐1111. © 2011 Wiley Periodicals, Inc.
Improving the performance of diffusion‐weighted inner field‐of‐view echo‐planar imaging based on 2D‐Selective radiofrequency excitations by tilting the excitation plane
Authors: Finsterbusch Jürgen
Published: December 2011

Purpose:

To improve the performance and flexibility of diffusion‐weighted inner field‐of‐view (FOV) echo‐planar imaging (EPI) based on 2D‐selective radiofrequency (RF) excitations by 1) using higher gradient amplitudes for outer excitation lines, and 2) tilting the excitation plane such that the unwanted side excitations do not overlap with the current image slice or other slices to be acquired.

Materials and Methods:

Acquisitions with a conventional (untilted) and the improved setup were compared and inner FOV diffusion tensor measurements were performed in the human brain and spinal cord with voxel sizes of 1.0 × 1.0 × 5.0 mm3 and 0.6 × 0.6 × 5.0 mm3 on a 3 T whole‐body magnetic resonance imaging (MRI) system.

Results:

With the modified setup, the 2D‐selective RF excitations can be considerably shortened (e.g., from 26 msec to 6 msec) which 1) avoids profile distortions in the presence of magnetic field inhomogeneities, and 2) reduces the required echo time and increases the signal‐to‐noise ratio accordingly, e.g., by about 20% in the spinal cord.

Conclusion:

Tilting the excitation plane and applying variable gradient amplitudes improves the applicability of inner FOV EPI based on 2D‐selective RF excitations. J. Magn. Reson. Imaging 2012;35:984–992. © 2011 Wiley Periodicals, Inc.
Molecular characterization of wild‐type measles viruses in Tamil Nadu, India, during 2005–2006: Relationship of genotype D8 strains from Tamil Nadu to global strains
Authors: Duraisamy Raja , Rota Paul A , Palani Gunasekaran , Elango Varalakshmi , Sambasivam Mohana , Lowe Luis , Lopareva Elena , Ramamurty Nalini
Published: December 2011

Molecular characterization of measles viruses is a valuable tool for measuring the effectiveness of measles control and elimination programmes. WHO recommends that virological surveillance be conducted during all phases of measles control to document circulation of indigenous strains and trace future importation. This report describes the genetic characterization of wild type measles viruses from Tamil Nadu, India isolated between January 2005 and January 2006. In the study, 304 suspected measles cases (292 from 56 outbreaks and 12 sporadic cases) were investigated. Blood samples were collected from suspected measles outbreaks and 11 suspected sporadic cases and tested for the presence of measles and rubella specific IgM. Based on serological results, 53 outbreaks were confirmed as measles, 2 as a combination of measles and rubella, and 1 negative for both. Eight sporadic cases were confirmed as measles and one as rubella. Throat swab and urine samples were collected for virus isolation and 28 isolates were obtained. Sequencing and analysis showed that 3 isolates belonged to genotype D4 and 25 to genotype D8. Comparison of the genotype D8 sequences from Tamil Nadu with previously reported genotype D8 sequences from India and abroad showed six distinct clusters with Tamil Nadu strains forming two clusters. This study has established baseline molecular data and is the first report that describes genetic diversity of circulating measles strains in Tamil Nadu, a state in India. D8 has multiple lineages and this has been linked with importation of measles into the USA and UK. J. Med. Virol. 84:348–357, 2012. © 2011 Wiley Periodicals, Inc.