bluuebunny/crossref_metadata_2025 huggingface dataset:
Color measurement of a ruby
Authors: Liu Yan , Lu Taijin , Mu Tao , Chen Hua , Ke Jie
Published: May 2012

The impurity transition element chromium Cr3+ in ruby can be excited to high energy levels by absorbing visible light. When the excited Cr3+ returns to ground state through an intermediate energy level, the ruby emits red light as fluorescence. The fluorescence of ruby is actually caused by visible light, not by ultraviolet. The color of ruby is attributed to both the absorption and the fluorescence. The spectrum of a natural ruby under visible light is directly measured by a dual integrating sphere spectrometer. The measured spectrum includes both the spectral reflectance and the fluorescence caused by visible light. This study confirmed that the red fluorescence of ruby is indeed caused by visible light, not by ultraviolet radiation. In addition, average color of the ruby is calculated from the measured spectrum, and true color grade is also obtained by the artificial intelligent software of the spectrometer. © 2012 Wiley Periodicals, Inc. Col Res Appl, 38, 328–333, 2013
Real‐Time Spatial Gene Expression Analysis within Current‐Producing Biofilms
Authors: Franks Ashley E. , Glaven Richard H. , Lovley Derek R.
Published: May 2012

The expression of genes involved in central metabolism and extracellular electron transfer was examined in real‐time in current‐producing anode biofilms of Geobacter sulfurreducens. Strains of G. sulfurreducens were generated, in which the expression of the gene for a short half‐life fluorescent protein was placed under control of the promoter of the genes of interest. Anode biofilms were grown in a chamber that permitted direct examination of the cell fluorescence with confocal scanning laser microscopy. Studies on nifD and citrate synthase expression in response to environmental changes demonstrated that the reporter system revealed initiation and termination of gene transcription. Uniform expression throughout the biofilms was noted for the genes for citrate synthase; PilA, the structural protein of the conductive pili; and OmcZ, a c‐type cytochrome essential for optimal current production, which was localized at the anode‐biofilm interface. These results demonstrate that even cells at great distance from the anode, or within expected low‐pH zones, are metabolically active and likely to contribute to current production and that there are factors other than gene expression differences influencing the distribution of OmcZ. This real‐time reporter approach is likely to be a useful tool in optimizing the design of technologies relying on microbe‐electrode interactions.
Second‐order statistics of system with N‐branch microdiversity and L‐branch macrodiversity operating over gamma shadowed Nakagami‐m fading channels
Authors: Sekulović Nikola M. , Stefanović Mihajlo Č. , Milović Daniela M. , Stanojčić Selena Ž.
Published: May 2012

The problem concerning short‐term fading and long‐term fading (shadowing) and their deleterious effects on wireless systems performance has been in focus for a long time. In this paper, motivated by the results of propagation measurements in land‐mobile and indoor‐mobile systems, and by the fact that gamma distribution can describe shadowing reliably, Nakagami‐m distribution is used to model the signal envelope and gamma distribution is used to model the average signal power. Receive diversity with maximal‐ratio combining and selection combining is implemented at the microlevel and macrolevel, respectively. The general case is explored, which assumes that microdiversity and macrodiversity are provided through arbitrary number of channels. Because shadowing has larger correlation distance than short‐term fading, correlated macrodiversity channels are studied. This paper investigates the dynamics of the received signal. A novel rapidly converging infinite‐series expression for average level crossing rate and average fade duration are obtained. Numerical results are graphically presented to examine the impact of fading severity, shadowing severity, number of diversity branches at the microlevel, number of base stations and correlation between base stations to the system's performance. Computer simulations are also performed to verify the validity and the accuracy of proposed theoretical analysis. Copyright © 2012 John Wiley & Sons, Ltd.
Chiral (Mercaptophenyl)oxazolines as Auxiliaries for Asymmetric Coordination Chemistry
Authors: Wenzel Marianne , Meggers Eric
Published: May 2012

(4S)‐2‐(4‐Isopropyl‐4,5‐dihydrooxazol‐2‐yl)‐4‐nitrobenzenethiol {(S)‐TS} and its tert‐butyl derivative {(S)‐TS′} were developed as chiral auxiliaries for the asymmetric synthesis of polypyridyl ruthenium complexes. In their deprotonated form, these (mercaptophenyl)oxazolines were used as bidentate ligands and allowed the efficient transfer of chirality from the oxazoline moiety to the ruthenium stereocenter. After the induction of the absolute metal‐centered configuration, the auxiliaries were labilized by converting the coordinated thiolate into a thioether ligand upon methylation with Meerwein salt, followed by the thermal replacement with 2,2′‐bipyridine or 1,10‐phenanthroline ligands under retention of configuration to afford octahedral polypyridyl ruthenium complexes with high enantiomeric excesses. These thiol‐based auxiliaries complement our previously developed acid‐labile chiral auxiliaries and thus expand the toolbox for the asymmetric synthesis of chiral ruthenium complexes.
Silver nanoparticle‐induced mutations and oxidative stress in mouse lymphoma cells
Authors: Mei Nan , Zhang Yongbin , Chen Ying , Guo Xiaoqing , Ding Wei , Ali Syed F. , Biris Alexandru S. , Rice Penelope , Moore Martha M. , Chen Tao
Published: May 2012

Silver nanoparticles (Ag‐NPs) have increasingly been used for coatings on various textiles and certain implants, for the treatment of wounds and burns, as a water disinfectant, and in air‐freshener sprays. The wide use of Ag‐NPs may have potential human health impacts. In this study, the mutagenicity of 5‐nm Ag‐NPs was evaluated in the mouse lymphoma assay system, and modes of action were assessed using standard alkaline and enzyme‐modified Comet assays and gene expression analysis. Treatments of L5178Y/Tk+/‐ mouse lymphoma cells with 5‐nm uncoated Ag‐NPs resulted in a significant yield of mutants at doses between 3 and 6 μg/mL; the upper range was limited by toxicity. Loss of heterozygosity analysis of the Tk mutants revealed that treatments with uncoated Ag‐NPs induced mainly chromosomal alterations spanning less than 34 megabase pairs on chromosome 11. Although no significant induction of DNA damage in Ag‐NP‐treated mouse lymphoma cells was observed in the standard Comet assay, the Ag‐NP treatments induced a dose‐responsive increase in oxidative DNA damage in the enzyme‐modified Comet assay in which oxidative lesion‐specific endonucleases were added. Gene expression analysis using an oxidative stress and antioxidant defense polymerase chain reaction (PCR) array showed that the expressions of 17 of the 59 genes on the arrays were altered in the cells treated with Ag‐NPs. These genes are involved in production of reactive oxygen species, oxidative stress response, antioxidants, oxygen transporters, and DNA repair. These results suggest that 5 nm Ag‐NPs are mutagenic in mouse lymphoma cells due to induction of oxidative stress by the Ag‐NPs. Environ. Mol. Mutagen. 2012. © 2012Wiley Periodicals, Inc.
Comprehensive analysis for viral elements and interleukin-28B polymorphisms in response to pegylated interferon plus ribavirin therapy in hepatitis C virus 1B infection
Authors: Maekawa Shinya , Sakamoto Minoru , Miura Mika , Kadokura Makoto , Sueki Ryota , Komase Kazuki , Shindo Hiroko , Komatsu Nobutoshi , Shindo Kuniaki , Kanayama Asuka , Ohmori Takako , Amemiya Fumitake , Takano Shinichi , Yamaguchi Tatsuya , Nakayama Yasuhiro , Kitamura Takatoshi , Inoue Taisuke , Okada Shunichi , Enomoto Nobuyuki
Published: May 2012

To comprehensively characterize the contribution of virological factors as well as interleukin-28B (IL28B) single-nucleotide polymorphisms (SNPs) in determining treatment responses in pegylated-interferon plus ribavirin (Peg-IFN/RBV) therapy for chronic hepatitis C virus (HCV)-1b infection, we undertook a retrospective cohort analysis for the pretreatment dominant complete HCV open reading frame (ORF) amino-acid (aa) sequence study in 103 consecutive HCV-1b Japanese patients. The dominant HCV sequences classified by the response were subjected to systematic sliding-window comparison analysis to characterize response-specific viral sequences, along with IL28B SNP analyses (rs8099917). In each comparison of the patients between with and without rapid viral response (RVR), nonearly viral response (nEVR), sustained virological response (SVR), or relapse, the following regions were extracted as most significantly associated with the different responses respectively: nonstructural protein 5A (NS5A) aa.2224-2248 (

P

= 1.2E-07); core aa.70 (

P

= 4E-04); NS5A aa.2340-2382 (

P

= 7.0E-08); and NS5A aa.2360-2377 (

P

= 1.1E-05). Those NS5A regions nearly coincided with the interferon (IFN) sensitivity-determining region (NS5A aa.2209-2248) and the IFN/RBV resistance-determining region (NS5A aa.2339-2379). In a multivariate analysis, the IL28B SNP (odds ratio [OR] = 16.8;

P

= 0.009) and NS5A aa.2340-2382 (OR = 13.8;

P

= 0.0003) were extracted as the two most-significant independent variables contributing to the final outcome.

Conclusion:

In Peg-IFN/RBV therapy, polymorphisms in IL28B, NS5A aa.2224-2248, core aa.70, and, most important, NS5A aa.2340-2382 have a tremendous influence on treatment response in association with viral kinetics, resulting in significantly different outcomes in chronic HCV-1b infection.
Cd81/Cd9 Tetraspanins Aid Plasmacytoid Dendritic Cells in Recognition of Hepatitis C Virus–Infected Cells And Induction of Interferon-Alpha
Authors: Zhang Shuye , Kodys Karen , Babcock Gregory J. , Szabo Gyongyi
Published: May 2012

Recognition of hepatitis C virus (HCV)-infected hepatocyes and interferon (IFN) induction are critical in antiviral immune response. We hypothesized that cell-cell contact between plasmacytoid dendritic cells (pDCs) and HCV-infected cells was required for IFN-α induction through the involvement of cell-surface molecules. Coculture of human peripheral blood mononuclear cells (PBMCs) with genotype 1a full-length (FL) HCV genomic replicon cells or genotype 2a Japanese fulminant hepatitis type 1 (JFH-1) virus-infected hepatoma cells (JFH-1), and not with uninfected hepatoma cells (Huh7.5), induced IFN-α production. Depletion of pDCs from PBMCs attenuated IFN-α release, and purified pDCs produced high levels of IFN-α after coculture with FL replicons or JFH-1-infected cells. IFN-α induction by HCV-containing hepatoma cells required viral replication, direct cell-cell contact with pDCs, and receptor-mediated endocytosis. We determined that the tetraspanin proteins, CD81 and CD9, and not other HCV entry receptors, were required for IFN-α induction in pDCs by HCV-infected hepatoma cells. Disruption of cholesterol-rich membrane microdomains, the localization site of CD81, or inhibition of the CD81 downstream molecule, Rac GTPase, inhibited IFN-α production. IFN-α induction involved HCV RNA and Toll-like receptor (TLR) 7. IFN-α production by HCV-infected hepatoma cells was decreased in pDCs from HCV-infected patients, compared to healthy controls. We found that preexposure of healthy PBMCs to HCV viral particles attenuated IFN-α induction by HCV-infected hepatoma cells or TLR ligands, and this inhibitory effect could be prevented by an anti-HCV envelope glycoprotein 2–blocking antibody. Conclusion: Our novel data show that recognition of HCV-infected hepatoma cells by pDCs involves CD81- and CD9-associated membrane microdomains and induces potent IFN-α production. (HEPATOLOGY 2013;58:940–949)
Modeling of the effect of flow depth on sediment discharged by rain‐impacted flows from sheet and interrill erosion areas: a review
Authors: Kinnell Peter Ian Alexander
Published: May 2012

Sediment, nutrients and pollutants discharged from sheet and interrill erosion areas by rain‐impacted flows may influence water quality in streams and rivers. The depth of water on the soil surface influences the capacity of raindrop impacts to detach soil material underlying rain‐impacted flows, and a number of so‐called process‐based and mechanistic models erroneously use equations on the basis of the effect of water depth on splash erosion to account for this effect. Also, a number of these models require complex mathematical solutions to make them operate and can only predict sediment composition and discharges well if many of their parameters are calibrated specifically to the situations where they are being applied. Experiments with rain‐impacted flows, where flow depth and velocity over eroding surfaces have been controlled, have been reported in the literature and provide more appropriate equations to account for the drop size – flow depth interactions that affect detachment and transport of particles in rain‐impacted flows. There is a need to develop modeling approaches that rely on relevant data obtained under well‐controlled flow conditions where flow depths and velocities are known. Copyright © 2012 John Wiley & Sons, Ltd.
Tiam1 is associated with hepatocellular carcinoma metastasis
Authors: Huang Jing , Ye Xianghua , Guan Jian , Chen Bin , Li Qisheng , Zheng Xiaokang , Liu Laiyu , Wang Shuang , Ding Yanqing , Ding Yi , Chen Longhua
Published: May 2012

We have previously demonstrated that overexpression of T lymphoma invasion and metastasis 1 (Tiam1) is correlated with poor prognosis in patients with hepatocellular carcinoma (HCC). In this study, we tried to further investigate the potential roles of Tiam1 in the progression of HCC in a larger set of samples. By detecting Tiam1 expression in 213 HCC patients, we observed that Tiam1 had a higher probability of being overexpressed in HCC patients with metastasis than those without metastasis (68.3% vs. 52.7%, p = 0.036). In addition, the cell line with high metastatic potential expressed more Tiam1 than did the cell line with low metastatic potential. Overexpression of Tiam1 was suggested to be significantly correlated with HCC metastasis. We stably upregulated Tiam1 expression in MHCC97L as well as knocked down Tiam1 expression in HCCLM6. We also investigated the effects of Tiam1 overexpression and knockdown on HCC cells proliferation, migration and invasion in vitro and on tumorigenicity and metastasis in vivo. Overexpression of Tiam1 increased proliferation, migration and invasion of MHCC97L cells, while knockdown of Tiam1 in HCCLM6 cells resulted in the reverse. In vivo functional studies showed upregulation of Tiam1 expression led to an enhancement of tumorigenicity and metastatic potential in mice. However, knockdown of Tiam1 expression exhibited nearly 2.2‐fold retardation in tumor growth and great inhibition on tumor metastases. Our results indicate that Tiam1, as a metastasis‐related gene, may contribute to HCC invasion and metastasis, and consequently, it may be a useful biomarker for therapeutic strategy and control in HCC treatment.
Targeting of syndecan‐1 by microRNA miR‐10b promotes breast cancer cell motility and invasiveness via a Rho‐GTPase‐ and E‐cadherin‐dependent mechanism
Authors: Ibrahim Sherif A. , Yip George W. , Stock Christian , Pan Jun‐Wei , Neubauer Claudia , Poeter Michaela , Pupjalis Danute , Koo Chuay Yeng , Kelsch Reinhard , Schüle Roland , Rescher Ursula , Kiesel Ludwig , Götte Martin
Published: May 2012

microRNAs are small endogenous noncoding RNAs, which post‐transcriptionally regulate gene expression. In breast cancer, overexpression of the transmembrane heparan sulfate proteoglycan syndecan‐1, a predicted target of the oncomiR miR‐10b, correlates with poor clinical outcome. To investigate the potential functional relationship of miR‐10b and syndecan‐1, MDA‐MB‐231 and MCF‐7 breast cancer cells were transiently transfected with pre‐miR‐10b, syndecan‐1 siRNA or control reagents, respectively. Altered cell behavior was monitored by proliferation, migration and invasion chamber assays, and time‐lapse video microscopy. miR‐10b overexpression induced post‐transcriptional downregulation of syndecan‐1, as demonstrated by quantitative real‐time PCR (qPCR), flow cytometry, and 3′UTR luciferase assays, resulting in increased cancer cell migration and matrigel invasiveness. Syndecan‐1 silencing generated a copy of this phenotype. Adhesion to fibronectin and laminin and basal cell proliferation was increased. Syndecan‐1 coimmunoprecipitated with focal adhesion kinase, which showed increased activation upon syndecan‐1 depletion. Affymetrix screening and confirmatory qPCR and Western blotting analysis of syndecan‐1‐deficient cells revealed upregulation of ATF‐2, COX‐2, cadherin‐11, vinculin, actin γ 2, MYL9, transgelin‐1, RhoA/C, matrix metalloproteinase 2 (MMP2) and heparanase, and downregulation of AML1/RUNX1, E‐cadherin, CLDN1, p21WAF/CIP, cyclin‐dependent kinase 6, TLR‐4, PAI1/2, Collagen1alpha1, JHDM1D, Mpp4, MMP9, matrilin‐2 and ANXA3/A10. Video microscopy demonstrated massively increased Rho kinase‐dependent motility of syndecan‐1‐depleted cells, which displayed increased filopodia formation. We conclude that syndecan‐1 is a novel target of the oncomiR miR‐10b. Rho‐GTPase‐dependent modulation of cytoskeletal function and downregulation of E‐cadherin expression are identified as relevant effectors of the miR‐10b‐syndecan‐1 axis, which emerges as a promising target for the development of new therapeutic approaches for breast cancer.
Clinical characteristics influence in vitro action of 1,25-dihydroxyvitamin D3 in human marrow stromal cells
Authors: Zhou Shuanhu , Glowacki Julie , Kim Sung Won , Hahne Jochen , Geng Shuo , Mueller Stefan M , Shen Longxiang , Bleiberg Ilan , LeBoff Meryl S
Published: May 2012

Vitamin D is important for bone health, with low vitamin D levels being associated with skeletal fragility and fractures. Among its other biological activities, 1,25-dihydroxyvitamin D (1,25(OH)2D), stimulates the in vitro differentiation of human marrow stromal cells (hMSCs) to osteoblasts, which can be monitored by increases in alkaline phosphatase enzyme activity or osteocalcin gene expression. In this study, we tested the hypotheses that age and clinical attributes of subjects influence in vitro responsiveness of hMSCs to 1,25(OH)2D3. In a cohort of subjects whose hMSCs were isolated from bone marrow discarded during hip replacement surgery for osteoarthritis, there were significant inverse correlations with age for bone mineral density, renal function, body mass index, fat mass index, and lean mass index (n = 36–53). There were significant correlations with serum 25(OH)D for serum parathyroid hormone (PTH), body mass index, fat mass index, and lean mass index (n = 47–50). In vivo–in vitro correlation analyses indicated that there were significantly greater in vitro effects of 1,25(OH)2D3 to stimulate osteoblast differentiation in hMSCs obtained from subjects who were younger than 65 years of age, or who had serum 25(OH)D ≤ 20 ng/mL, elevated serum PTH, or better renal function, assessed by estimated glomerular filtration rate. The greater in vitro stimulation of osteoblast differentiation by 1,25(OH)2D3 in hMSCs from vitamin D-deficient subjects suggests that vitamin D replenishment may lead to more vigorous bone formation in subjects at risk. © 2012 American Society for Bone and Mineral Research.
Peptide-based mediated disruption of N-cadherin-LRP5/6 interaction promotes Wnt signaling and bone formation
Authors: Haÿ Eric , Buczkowski Thibault , Marty Caroline , Da Nascimento Sophie , Sonnet Pascal , Marie Pierre J
Published: May 2012

Wnt signaling plays an important role in skeletal biology and diseases. In osteoblasts, we recently showed that the cell-cell adhesion molecule N-cadherin interacts with the Wnt coreceptors LRP5/6 to regulate osteogenesis. In this study we investigated whether targeting the intracellular domain of N-cadherin that interacts with LRP5/6 may promote Wnt signaling and bone formation. By investigating the molecular interactions between the Wnt coreceptors LRP5/6 and N-cadherin, we identified specific LRP5/6- and N-cadherin–interacting intracellular domains that impact Wnt/β-catenin signaling in murine osteoblasts. We showed that truncated N-cadherin constructs that impair N-cadherin-LRP5/6 interactions promote Wnt/β-catenin signaling and osteoblast differentiation. Based on this finding, we developed a peptide-based approach targeting N-cadherin-LRP5 interaction for promoting Wnt signaling and osteoblast function. We found that a competitor peptide containing the 28 last amino acids of LRP5 disrupts LRP5/6-N-cadherin interaction and thereby enhances Wnt/β-catenin signaling in osteoblasts. We also show that the peptide-mediated disruption of N-cadherin-LRP5/6 interaction increases Wnt/β-catenin signaling and osteoblast function in vitro and promotes calvaria bone formation in vivo. The targeted competitor peptide-based strategy reported here may provide a novel approach to stimulate Wnt/β-catenin signaling that can be used for promoting osteoblast function and bone formation. © 2012 American Society for Bone and Mineral Research.
Time‐dependent dosing of Fe2+ for improved lipopeptide production by marine Bacillus megaterium
Authors: Rangarajan Vivek , Dhanarajan Gunaseelan , Kumar Ramya , Sen Ramkrishna , Mandal Mahitosh
Published: May 2012

BACKGROUND: Lipopeptide production is strongly influenced by trace metals. The availability of free Fe2+ in the media throughout the process of fermentation was found to be very critical. Since free Fe2+ was reported to be sequestered by the lipopeptide as it was produced, intermittent feeding of Fe2+ was strategized and optimized for enhanced lipopeptide production by marine Bacillus megaterium in glucose mineral salts medium (GMSM).

RESULTS: Studies with the single‐dose Fe2+ (0.48 mmol L−1) supplementation after 8 h of fermentation resulted in lipopeptide concentration of 3.3 ± 0.1 g L−1. Lipopeptide production was further enhanced to 4.2 ± 0.15 g L−1 by adopting a multi‐dose Fe2+ feeding strategy. The maximum product yield (YP/S) of 0.24 ± 0.02 g g−1 with specific product formation rate (qp) of 0.124 ± 0.01 g g−1 h−1 was achieved when 0.48 mmol L−1 Fe2+ was fed intermittently at different times as per the designed strategy.

CONCLUSION: Lipopeptide concentration was improved 4.7‐fold by single‐dosing and 5.8‐fold by multiple dosing of Fe2+, when compared with GMSM without Fe2+ supplementation. Copyright © 2012 Society of Chemical Industry
Modelling and performance evaluation of chromatographic monosaccharide recovery from concentrated acid lignocellulosic hydrolysates
Authors: Heinonen Jari , Sainio Tuomo
Published: May 2012

BACKGROUND: Chromatographic fractionation of concentrated acid lignocellulosic hydrolysates was investigated. The goal was to present a model that can be used in designing and performance evaluation of the fractionation process. Simple models were fitted to the experimental sorption data of the main components of the hydrolysates (sulfuric acid, monosaccharides, and acetic acid) on CS16GC resin. A column model which takes into account resin shrinking was derived.

RESULTS: Simulation results were found to be in good agreement with the experimental results. The isotherm models predicted correctly the co‐operative effect of H2SO4 on the sorption of the other adsorbates. The effect of column loading on the productivity of the separation process was studied with simulations. With 20 wt% H2SO4, the highest productivity was obtained with 11.5 vol% column loading. In addition, a process consisting of concentrated acid lignocellulose hydrolysis, batchwise chromatographic separation, and H2SO4 recycling was investigated. With the recycling, the maximum productivity was obtained with 18.2 vol% column loading.

CONCLUSIONS: It was demonstrated that the entire reactor‐separation process with internal recycling must be considered when evaluating the performance of the monosaccharide‐acid separation step. Process performance was found to decrease with increasing feed concentration of sulfuric acid. Copyright © 2012 Society of Chemical Industry
Start up of biological sequencing batch reactor (SBR) and short‐term biomass acclimation for polyhydroxyalkanoates production
Authors: Valentino Francesco , Brusca Angelo Antonio , Beccari Mario , Nuzzo Andrea , Zanaroli Giulio , Majone Mauro
Published: May 2012

BACKGROUND: The adaptation/selection of mixed microbial cultures under feast/famine conditions is an essential step for polyhydroxyalkanoates (PHA) production. This study investigated the short‐term adaptation of a mixed microbial culture (activated sludge) during the start up of a sequencing batch reactor (SBR).

RESULTS: Four different SBR runs were performed starting from different inocula and operated at the same organic load rate (8.5 gCOD L−1 d−1) and hydraulic retention time (1 day). At 3–7 days from SBR start up, the selected biomass was able to store PHA at comparable rate and yield with those obtained after long‐term acclimation. Independently from the time passed, a short feast phase was the key parameter to obtain PHA storage at high rate and yield in the following accumulation stage (244 mgCOD g−1CODnonPolym h−1 for specific storage rate and 48% COD COD−1 as PHA content in the biomass). The DGGE profiles showed that the good storage performance and the structure of the microbial community were not fully correlated.

CONCLUSIONS: The results suggest a new strategy for operating the PHA accumulation stage directly in the SBR, after very short biomass adaptation, instead of using two separate reactors for biomass enrichment and PHA accumulation, respectively. © 2012 Society of Chemical Industry
Cell immobilization technique for biotrickle filtering of isopropyl alcohol waste vapor generated by high‐technology industries
Authors: Tsai Shen‐Long , Lin Chi‐Wen , Wu Chih‐Hung , Xin Baoping
Published: May 2012

BACKGROUND: A bench‐scale biotrickling filter coupled with Pseudomonas citronellolis YAIP521‐immobilized polyvinyl alcohol (PVA)/alginate beads was developed for kinetic analysis of microbial removal of isopropyl alcohol (IPA), an organic solvent widely used for fabricating wafers and printed circuit boards.

RESULTS: Response surface methodology (RSM) showed that the optimal ratio of PVA to alginate was 7.5 g to 0.8 g. More than 95% of IPA removal could be achieved at an inlet concentration of 220 ± 34 ppm (w/w) under short residency time. System stability decreased under high IPA concentration and intermittent shock‐loading conditions but increased when using cell‐immobilized beads because the buffer effect limited the adverse impacts of high IPA concentrations on microorganisms, and the system gradually stabilized with IPA removal efficiency as high as 95%. Nevertheless, qPCR indicated that intermittent shock‐loading decreased the biomass in the beads.

CONCLUSION: The experimental results showed that the biotrickling filter system developed effectively diminishes the inhibitory effects of elevated IPA concentration on microbial growth, thereby solving the problem of high IPA loading often encountered in the electronic high‐tech industries. The design of the system along with the population dynamics and reaction kinetics provide superior information to ensure the success of the biotrickling filter system. © 2012 Society of Chemical Industry
POLITICAL ECONOMY AND HISTORY: MAKING SENSE OF HEALTH FINANCING IN SUB‐SAHARAN AFRICA
Authors: Eme Ichoku Hyacinth , Fonta William. M. , Ataguba John E.
Published: May 2012

This paper demonstrates that fundamental to lack of progress towards universal coverage in sub‐Saharan Africa is an elitist post‐colonial political economy that dominates the social organisation in the sub‐region. Too often, it seems that analyses of these issues ignore history and take no or little account of these post‐colonial influences that today still have a bearing on policy in various sectors, especially in health care. We conclude that the achievement of this objective has to be a long‐term process but one that cannot forget history. Various influences are, however, already moving societies in the right direction. Copyright © 2012 John Wiley & Sons, Ltd.
Identification of protein SUMOylation sites by mass spectrometry using combined microwave‐assisted aspartic acid cleavage and tryptic digestion
Authors: Osula Omoruyi , Swatkoski Stephen , Cotter Robert J.
Published: May 2012

Small‐ubiquitin‐like modifier (SUMO) is a posttranslational modifier of protein substrates at lysine residues that conjugates to proteins in response to various changes in the cell. As a result of SUMO modification, marked changes in transcription regulation, DNA repair, subcellular localization and mitosis, among other cellular processes, are known to occur. However, although the identification of ubiquitylation sites by mass spectrometry is aided in part by the presence of a small di‐amino acid GlyGly “tag” that remains on lysine residues following tryptic digestion, SUMOylation poses a particular challenge as the absence of a basic residue near to the SUMO C‐terminus results in a significant 27 or 32‐amino‐acid sequence branch conjugated to the substrate peptide. MS/MS analyses of these branch peptides generally reveal abundant fragment ions resulting from cleavage of the SUMO tail, but which obscure those needed for characterizing the target peptide sequence. Other approaches for identifying SUMO substrates exist and include overexpression of the SUMO isoforms using an N‐terminal histidine tag, as well as site‐directed mutagenesis of the C‐terminal end of the SUMO sequence. Here, we employ combined enzymatic/chemical approaches, which serve to shorten the SUMO tag and thus help to simplify SUMO spectra, making interpretation of mass spectra and location of the SUMOylation site easier. As described in this report, we demonstrate a method for identifying SUMOylation sites using three commercially available SUMO‐ modified isoforms and by employing acid‐only and acid/trypsin cleavage strategies. These approaches were carried out using MALDI‐time‐of‐flight (TOF) and LC/MS instrumentation, along with collision induced dissociation (CID) and electron transfer dissociation (ETD). Copyright © 2012 John Wiley & Sons, Ltd.
Simultaneous analysis of several synthetic cannabinoids, THC, CBD and CBN, in hair by ultra‐high performance liquid chromatography tandem mass spectrometry. Method validation and application to real samples
Authors: Salomone A. , Gerace E. , D'Urso F. , Di Corcia D. , Vincenti M.
Published: May 2012

A simple procedure for the quantitative detection of JWH‐018, JWH‐073, JWH 200, JWH‐250, HU‐210, Δ9‐tetrahydrocannabinol (THC), cannabidiol (CBD) and cannabinol (CBN) in hair has been developed and fully validated. After digestion with NaOH and liquid–liquid extraction, the separation was performed with an ultra‐high performance liquid chromatography system coupled to a triple quadrupole mass spectrometer operating in the selected reaction monitoring mode. The absence of matrix interferents, together with excellent repeatability of both retention times and relative abundances of diagnostic transitions, allowed the correct identification of all analytes tested. The method was linear in two different intervals at low and high concentration, with correlation coefficient values between 0.9933 and 0.9991. Quantitation limits ranged from 0.07 pg/mg for JWH‐200 up to 18 pg/mg for CBD The present method for the determination of several cannabinoids in hair proved to be simple, fast, specific and sensitive. The method was successfully applied to the analysis of 179 real samples collected from proven consumers of Cannabis, among which 14 were found positive to at least one synthetic cannabinoid. Copyright © 2012 John Wiley & Sons, Ltd.
Rate of change of composition of lettuce in response to nitrogen depletion or re‐supply
Authors: Gent Martin P N
Published: May 2012

BACKGROUND: Lettuce accumulates high levels of nitrate when grown in winter in heated greenhouses. Temporarily removing nitrate from the nutrient solution may lower tissue nitrate. The composition of hydroponic lettuce was examined over a 6‐ to 13‐day interval of nitrogen depletion or re‐supply.

RESULTS: Growth responses were delayed by 6 days or more after changing N supply, except root growth responded in 3–4 days. The total nitrogen increased or decreased for 6 days. When measured in the light, nitrate concentration changed 10‐fold in roots within 2 days. The change in leaf and petiole tissue was slower. Amino acids responded to a change in N‐supply within 1 day in leaf and root. All tissues of N‐depleted plants had more sugars compared to N‐sufficient plants within 2 days after the start of depletion. Nitrogen depletion had reversible effects on growth or tissue concentrations if applied for only 6 days.

CONCLUSIONS: Tissue nitrate changed more rapidly than total nitrogen, or growth responses. However, nitrate changed more slowly in petiole than in leaf blade or roots, and larger plants have more biomass in petioles. Thus, clearing nitrate from lettuce is slower for large compared to smaller lettuce plants. Copyright © 2012 Society of Chemical Industry
High‐temperature conditioning induces chilling tolerance in mandarin fruit: a cell wall approach
Authors: Holland Nély , Nunes Francisca L da Silva , de Medeiros Igor U Dantas , Lafuente Maria Teresa
Published: May 2012

BACKGROUND: High‐temperature conditioning (3 days at 37 °C and 95% relative humidity), which protects ‘Fortune’ mandarins from chilling injury (CI), manifested as pitting in the outer part of the peel (flavedo), was applied prior to cold storage (2 °C) in order to investigate the involvement of cell wall composition in the chilling tolerance of mandarins.

RESULTS: Both low‐temperature storage and high‐temperature conditioning barely modified the alcohol‐insoluble substance (AIS) content or the degree of pectin esterification in the flavedo. Water‐soluble pectins (WSP) were higher in heat‐conditioned than in non‐conditioned fruits at the onset of CI. In addition, the heat‐conditioning treatment was able to increase chelator‐soluble pectins (CSP) after short cold storage periods. Covalently bound polyuronides in alkali‐soluble pectins (ASP) increased only in fruits with high incidence of CI. Cellulose and hemicellulose increased at 2 °C in both conditioned and non‐conditioned fruits, indicating that these polysaccharides may be altered by low temperature but are not related to chilling‐induced damage.

CONCLUSION: High‐temperature conditioning may reduce chilling‐induced flavedo pitting in ‘Fortune’ mandarin fruit by maintaining normal levels of WSP and increasing putative sites for calcium bridge formation within the cell wall, but not by inducing changes in other matrix cell wall components. Copyright © 2012 Society of Chemical Industry
Invasive fungal infections following liver transplantation: Incidence, risk factors, survival, and impact of fluconazole-resistant Candida parapsilosis (2003-2007)
Authors: Raghuram Anupama , Restrepo Alejandro , Safadjou Saman , Cooley Jennifer , Orloff Mark , Hardy Dwight , Butler Sam , Koval Christine E.
Published: May 2012

Invasive fungal infections (IFIs) are associated with a high mortality rate for liver transplantation (LT) recipients. To study the incidence of and risk factors for IFIs in LT recipients and the associated mortality rates, we retrospectively reviewed the records of first-time deceased donor LT recipients (January 2003 to December 2007). The incidence of IFIs was 12%. Non-albicans
Candida species accounted for 55% of IFIs; 50% of these IFIs were Candida parapsilosis. Only 43% of Candida isolates were fluconazole-susceptible (minimum inhibitory concentration ≤ 8 μ/mL). All C. parapsilosis isolates were fluconazole-resistant, and this coincided with a surge of these isolates during a peak period of LT. Factors associated with IFIs included a creatinine level > 2 mg/mL [hazard ratio (OR) = 2.4, 95% confidence interval (CI) = 1.2-5.0, P = 0.01], a Model for End-Stage Liver Disease score > 25 (OR = 2.4, 95% CI = 1.2-4.9, P = 0.02), pretransplant fungal colonization (OR = 7.0, 95% CI = 3.2-15.3, P < 0.001), and a daily prophylactic fluconazole dosage < 200 mg (OR = 2.8, 95% CI = 1.1-7.4, P = 0.03). According to a multivariate analysis, only pretransplant fungal colonization was associated with IFIs (OR = 7.8, 95% CI = 3.9-16.2, P < 0.001). The 1-year patient survival rates with and without IFIs were 41% and 80%, respectively, and the survival rates with C. parapsilosis, other non-albicans
Candida, and Candida albicans IFIs were 28%, 50%, and 75%, respectively. In conclusion, IFIs after LT (especially non-albicans
Candida species and fluconazole-resistant C. parapsilosis) were associated with reduced survival. The risk factors highlight the importance of pretransplant risk assessments. The identification of pretransplant fungal colonization may allow for risk modifications before or at the time of LT. Additionally, the number of LT procedures and prophylactic strategies may affect institutional outbreaks of resistant Candida strains. Liver Transpl, 2012. © 2012 AASLD.
The Effect of Melt Extrusion Process Parameters on Rotary‐Evaporated Poly(propylene) Nanocomposites
Authors: Radhakrishnan Vinod K. , Davis Virginia A. , Davis Edward W.
Published: May 2012

Design of experiments is employed to investigate the interrelationships between processing and nanotube surface chemistry on the properties of PP nanocomposites. Statistically significant effects of nanomaterial type and concentration, extrusion temperature, screw speed, and recirculation time, and their interactions, on nanocomposite thermal properties and stability are isolated. The effects of these factors on the shear storage modulus, the low‐frequency slope of the shear storage modulus, decomposition temperature, and melt temperature are explored. Nanotube concentration has the most significant effect in enhancing the decomposition temperature of the nanocomposite, while long extrusion time and higher temperatures lead to deteriorated properties.

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Water‐Stable Nonwovens Composed of Electrospun Fibers from Aqueous Dispersions by Photo‐Cross‐Linking
Authors: Giebel Elisabeth , Greiner Andreas
Published: May 2012

Copolymers of MMA, BA, and MABP are prepared by radical emulsion polymerization in water. As a result aqueous dispersions of these copolymers are obtained with particle sizes around 60–120 nm. After addition of some PVA the dispersions are electrospun. The resulting fibers display different morphologies depending on the copolymer composition. Inter‐ and intra‐particle cross‐linking is achieved by photo‐cross‐linking induced by the MABP moieties yielding fibers with good thermomechanical properties depending on the content of MABP. With this approach, thermomechanically stable electrospun fibers with smooth surface structure can be obtained by electrospinning from water.

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MR imaging of the amide‐proton transfer effect and the pH‐insensitive nuclear overhauser effect at 9.4 T
Authors: Jin Tao , Wang Ping , Zong Xiaopeng , Kim Seong‐Gi
Published: May 2012

The amide proton transfer (APT) effect has emerged as a unique endogenous molecular imaging contrast mechanism with great clinical potentials. However, in vivo quantitative mapping of APT using the conventional asymmetry analysis is difficult due to the confounding nuclear Overhauser effect (NOE) and the asymmetry of the magnetization transfer effect. Here, we showed that the asymmetry of magnetization transfer contrast from immobile macromolecules is highly significant, and the wide spectral separation associated with a high magnetic field of 9.4 T delineates APT and NOE peaks in a Z‐spectrum. Therefore, high‐resolution apparent APT and NOE maps can be obtained from measurements at three offsets. The apparent APT value was greater in gray matter compared to white matter in normal rat brain and was sensitive to tissue acidosis and correlated well with apparent diffusion coefficient in the rat focal ischemic brain. In contrast, no ischemia‐induced contrast was observed in the apparent NOE map. The concentration dependence and the pH insensitivity of NOE were confirmed in phantom experiments. Our results demonstrate that in vivo apparent APT and NOE maps can be easily obtained at high magnetic fields and the pH‐insensitive NOE may be a useful indicator of mobile macromolecular contents. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.
Oscillating and pulsed gradient diffusion magnetic resonance microscopy over an extendedb‐value range: Implications for the characterization of tissue microstructure
Authors: Portnoy S. , Flint J. J. , Blackband S. J. , Stanisz G. J.
Published: May 2012

Oscillating gradient spin‐echo (OGSE) pulse sequences have been proposed for acquiring diffusion data with very short diffusion times, which probe tissue structure at the subcellular scale. OGSE sequences are an alternative to pulsed gradient spin echo measurements, which typically probe longer diffusion times due to gradient limitations. In this investigation, a high‐strength (6600 G/cm) gradient designed for small‐sample microscopy was used to acquire OGSE and pulsed gradient spin echo data in a rat hippocampal specimen at microscopic resolution. Measurements covered a broad range of diffusion times (TDeff = 1.2–15.0 ms), frequencies (ω = 67–1000 Hz), andb‐values (b= 0–3.2 ms/μm2). Variations in apparent diffusion coefficient with frequency and diffusion time provided microstructural information at a scale much smaller than the imaging resolution. For a more direct comparison of the techniques, OGSE and pulsed gradient spin echo data were acquired with similar effective diffusion times. Measurements with similar TDeffwere consistent at lowb‐value (b< 1 ms/μm2), but diverged at higherb‐values. Experimental observations suggest that the effective diffusion time can be helpful in the interpretation of lowb‐value OGSE data. However, caution is required at higherb, where enhanced sensitivity to restriction and exchange render the effective diffusion time an unsuitable representation. Oscillating and pulsed gradient diffusion techniques offer unique, complementary information. In combination, the two methods provide a powerful tool for characterizing complex diffusion within biological tissues. Magn Reson Med 69:1131–1145, 2013. © 2012 Wiley Periodicals, Inc.
In vivo free induction decay based 3D multivoxel longitudinal hadamard spectroscopic imaging in the human brain at 3 T
Authors: Tal Assaf , Goelman Gadi , Gonen Oded
Published: May 2012

We propose and demonstrate a full 3D longitudinal Hadamard spectroscopic imaging scheme for obtaining chemical shift maps, using adiabatic inversion pulses to encode the spins' positions. The approach offers several advantages over conventional Fourier‐based encoding methods, including a localized point spread function; no aliasing, allowing for volumes of interest smaller than the object being imaged; an option for acquiring noncontiguous voxels; and inherent outer volume rejection. The latter allows for doing away with conventional outer volume suppression schemes, such as point resolved spectroscopy (PRESS) and stimulated echo acquisition mode (STEAM), and acquiring non‐spin‐echo spectra with short acquisition delay times, limited only by the excitation pulse's duration. This, in turn, minimizes T2 decay, maximizes the signal‐to‐noise ratio, and reduces J‐coupling induced signal decay. Results are presented for both a phantom and an in vivo healthy volunteer at 3 T. Magn Reson Med 69:903–911, 2013. © 2012 Wiley Periodicals, Inc.
Characterization of novel soybean‐oil‐based thermosensitive amphiphilic polymers for drug delivery applications
Authors: Abdekhodaie Mohammad J , Liu Zengshe , Erhan Sevim Z , Wu Xiao Yu
Published: May 2012

Hydrolyzed polymers of soybean oil (HPSO) and of epoxidized soybean oil (HPESO) were developed previously. Owing to their natural food origin and biocompatibility, we exploited further their potential as a drug delivery system and pharmaceutical excipients. This work aimed to investigate self‐assembly, thermal transition, interaction with various drugs and surface activity of these novel amphiphilic polymers. The critical micelle concentration of HPSO and HPESO was determined by the surface tension method. The molecular interaction between HPESO and anticancer drug doxorubicin HCl was examined. The effect of the polymers on the solution contact angle and surface energy of compressed tablets of hydrophobic drugs ibuprofen and nifedipine was measured. The thermal transition temperatures Ttr (cloud points) of the polymers in aqueous solutions increased with increasing polymer concentration. HPSO exhibited lower Ttr than HPESO. The critical micelle concentration was found to be 0.05 mg mL−1 for HPSO and 0.08 mg mL−1 for HPESO. Strong molecular interactions between HPESO and doxorubicin were observed. Both polymers reduced the interfacial energy and contact angles of drug tablets with more effect on ibuprofen tablets with the use of HPSO. These results suggest that the novel soybean‐oil‐based amphiphilic polymers have great potential for drug delivery and pharmaceutical formulations. Copyright © 2012 Society of Chemical Industry
Polyaldehydes: homopolymers, block copolymers and promising applications
Authors: Köstler Stefan
Published: May 2012

This minireview gives a brief overview on the polymerization of higher aldehydes, discusses current applications of certain polyaldehydes, and points toward potential future applications of these interesting materials. Although it was discovered long ago that several aldehydes can be polymerized, the application potential of these polymers was largely overlooked. This is somewhat surprising as many polyaldehydes show interesting properties such as fast and complete depolymerization triggered by chemical or thermal stimuli. Such stimuli‐responsive polymers can be useful materials in many applications in for example nanotechnology or drug delivery. By incorporating polyaldehydes into functional block copolymers even more versatile materials can be created. The increasing number of recent research examples demonstrates the growing interest in polyaldehydes as smart materials and their potential for novel applications. Copyright © 2012 Society of Chemical Industry
Impact of photovoltaic orientation on its relative economic value in wholesale energy markets
Authors: Hummon Marissa , Denholm Paul , Margolis Robert
Published: May 2012

Most calculations of optimum photovoltaic (PV) performance focus on maximizing annual energy production. However, given the seasonally and daily time varying electricity demand and resulting variation in price, the PV orientation resulting in maximum energy yield may not yield the maximum economic benefit. With the use of historical solar irradiance and wholesale market prices for several locations in the USA, we evaluate the benefits of a variety of orientations for fixed and tracking PV arrays. We find that orienting fixed arrays slightly to the west of due south generally increases their economic value in the simulated systems because the reduced generation on an annual basis is more than offset by increased generation in high‐value hours in late summer afternoons. However, this effect is small, typically providing an increase in value from 1% to 5%. The economic value of adjusting the orientation semi‐annually (May 1st and September 1st) and monthly shows a modest increase in value from 3% to 5%. Several other implications of this analysis are also discussed. Copyright © 2012 John Wiley & Sons, Ltd.