bluuebunny/crossref_metadata_2025 huggingface dataset:
Meta‐analysis of genetic polymorphisms in granulomatosis with polyangiitis (Wegener's) reveals shared susceptibility loci with rheumatoid arthritis
Authors: Chung Sharon A. , Xie Gang , Roshandel Delnaz , Sherva Richard , Edberg Jeffrey C. , Kravitz Megan , Dellaripa Paul F. , Hoffman Gary S. , Mahr Alfred D. , Seo Philip , Specks Ulrich , Spiera Robert F. , St.Clair E. William , Stone John H. , Plenge Robert M. , Siminovitch Katherine A. , Merkel Peter A. , Monach Paul A.
Published: April 2012

Objective

To examine the association of previously identified autoimmune disease susceptibility loci with granulomatosis with polyangiitis (Wegener's) (GPA), and to determine whether the genetic susceptibility profiles of other autoimmune diseases are associated with those of GPA.

Methods

Genetic data from 2 cohorts were meta‐analyzed. Genotypes for 168 previously identified single‐nucleotide polymorphisms (SNPs) associated with susceptibility to different autoimmune diseases were ascertained in a total of 880 patients with GPA and 1,969 control subjects of European descent. Single‐marker associations were identified using additive logistic regression models. Associations of multiple SNPs with GPA were assessed using genetic risk scores based on susceptibility loci for Crohn's disease, type 1 diabetes, systemic lupus erythematosus, rheumatoid arthritis (RA), celiac disease, and ulcerative colitis. Adjustment for population substructure was performed in all analyses, using ancestry‐informative markers and principal components analysis.

Results

Genetic polymorphisms in CTLA4 were significantly associated with GPA in the single‐marker meta‐analysis (odds ratio [OR] 0.79, 95% confidence interval [95% CI] 0.70–0.89, P = 9.8 × 10−5). The genetic risk score for RA susceptibility markers was significantly associated with GPA (OR 1.05 per 1‐unit increase in genetic risk score, 95% CI 1.02–1.08, P = 5.1 × 10−5).

Conclusion

RA and GPA may arise from a similar genetic predisposition. Aside from CTLA4, other loci previously found to be associated with common autoimmune diseases were not statistically significantly associated with GPA in this study.
Large‐scale production of human mesenchymal stem cells for clinical applications
Authors: Jung Sunghoon , Panchalingam Krishna M. , Wuerth Reynold D. , Rosenberg Lawrence , Behie Leo A.
Published: April 2012

Human mesenchymal stem cells (hMSCs) have many potential applications in tissue engineering and regenerative medicine. Currently, hMSCs are generated through conventional static adherent cultures in the presence of fetal bovine serum (FBS) for clinical applications (e.g., multiple sclerosis). However, these methods are not appropriate to meet the expected future demand for quality‐assured hMSCs for human therapeutic use. Hence, it is imperative to develop an effective hMSC production system, which should be controllable, reproducible, and scalable. To this end, efforts have been made by several international research groups to develop (i) alternative media either by replacing FBS with human‐sourced supplements (such as human serum or platelet lysate) or by identifying defined serum‐free formulations consisting of key growth/attachment factors, and (ii) controlled bioreactor protocols. In this regard, we review here current hMSC production technologies and future perspectives toward efficient methods for the generation of clinically relevant numbers of hMSC therapeutics.
Perfusion bioreactor studies of chondrocyte growth in alginate–chitosan capsules
Authors: Forsey Richard W. , Tare Rahul , Oreffo Richard O. C. , Chaudhuri Julian B.
Published: April 2012

The combination of progenitor cells, cell‐friendly scaffold, and a three‐dimensional culture system has been investigated for the culture of cartilage tissue. We have assessed chondrogenesis of alginate–chitosan‐encapsulated STRO‐1‐isolated human mesenchymal progenitor cells. In addition, ATDC‐5 cells and human articular chondrocytes were also evaluated. We have used a novel 3D bioreactor system that enabled perfusion of the capsules with culture medium up to 28 days. Results from culturing all cell types indicated chondrogenesis, both in static and bioreactor culture. The expression of SOX‐9 and type II collagen was examined as a marker of differentiation. ATDC‐5s expressed both SOX‐9 and type II collagen under perfused and static culture conditions. In monolayer cell culture, human articular chondrocytes did not express either SOX‐9 or type II collagen and STRO‐1 expressed alkaline phosphatase, indicating osteogenesis. However, when these cells were encapsulated in alginate–chitosan, both expressed SOX‐9 under static and perfused cultures, but type II collagen was only expressed under perfused culture conditions. We have also noted that the perfusion rates used were too low to ensure a significant advantage over static culture, but that use of the bioreactor eliminated the need for manual feeding and intervention of the cells over the 28‐day period.
Dried blood spot on‐card derivatization: an alternative form of sample handling to overcome the instability of thiorphan in biological matrix
Authors: Mess Jean‐Nicholas , Taillon Marie‐Pierre , Côté Cynthia , Garofolo Fabio
Published: April 2012

Thiorphan, the active metabolite of racecadotril, can undergo oxidation in biological matrices such as blood and plasma. In bioanalysis, a general approach for the stabilization of such a molecule is to derivatize the thiol group to a more stable thioether, often requiring complex handling procedures at the clinical site. In this research, the concept of dried blood spot (DBS) on‐card derivatization was evaluated to stabilize thiorphan. DBS cards were in‐house pre‐treated with 2‐bromo‐3′‐methoxyacetophenone and left to dry prior to blood spotting. Thiorphan was shown to be effectively derivatized to thiorphan–methoxyacetophenone once applied on the in‐house pre‐treated cards. Thiorphan–methoxyacetophenone was extracted by soaking a 6 mm DBS punch in methanol containing the internal standard (thiorphan–methoxyacetophenone‐D5). Chromatographic separation was achieved on a Waters XBridge C18 column with a gradient elution of 5 m m NH4HCO3 and methanol in 2.5 min and detection by ESI(+)/MS/MS. A linear (weighted 1/x2) relationship was obtained over a concentration range of 5.00–600.00 ng/mL. The assay met regulatory guidelines acceptance criteria for sensitivity, selectivity, precision and accuracy, matrix effect, recovery, dilution integrity and multiple stability evaluations. The DBS on‐card derivatization has shown to be an easy and reliable alternative form of sample collection for the quantification of thiorphan. Copyright © 2012 John Wiley & Sons, Ltd.
Neural correlates of action understanding in infants: influence of motor experience
Authors: Virji‐Babul N. , Rose A. , Moiseeva N. , Makan N.
Published: April 2012

Mirror neurons are recognized as a crucial aspect of motor and social learning yet we know little about their origins and development. Two competing hypotheses are highlighted in the literature. One suggests that mirror neurons may be innate and are an adaptation for action understanding. The alternative, proposes that mirror neurons develop through sensorimotor experience. To date, there has been little direct evidence from infant studies to support either argument. In the present study, we explored the temporal dynamics and spatial distribution of electroencephalography (EEG) brain responses in young infants during the observation of three distinct types of actions: (a) actions that are within the motor repertoire of infants, (b) actions that are not within the motor repertoire of infants, and (c) object motion. We show that young infants had significant motor resonance to all types of actions in the sensorimotor regions. Only observation of human goal‐directed actions led to significant responses in the parietal regions. Importantly, there was no significant mu desychronization observed in the temporal regions under any observation condition. In addition, the onset of mu desychronization occurred earliest in response to object motion, followed by reaching, and finally walking. Our results suggest that the infants may have a basic, experience‐independent sensorimotor mechanism optimized to detect all coherent motion that is modulated by experience.
Effect of lesion length on functional significance of intermediate long coronary lesions
Authors: López‐Palop Ramón , Carrillo Pilar , Cordero Alberto , Frutos Araceli , Mateo Irene , Mashlab Samer , Roldán Julian
Published: April 2012

Objective

To assess the relationship between lesion length and other angiographic parameters on the functional significance of long coronary lesions with moderate stenosis.

Background

Coronary revascularization is usually based on angiographic percent stenosis. Coronary stenosis length is not usually considered in daily clinical practice for revascularization decision‐making. The relevance of lesion length might be greater in longer lesions with intermediate stenosis.

Methods

All coronary lesions >20 mm and of 40–70% percent stenosis assessed by intracoronary pressure wire between 2007 and 2009 were included. Interventionists performing digital quantification of lesion stenosis were blinded to the result of fractional flow reserve (FFR). Correlations between angiographic data and FFR were analyzed.

Results

One hundred and six lesions from 103 patients were included. Reference diameter: 2.9 ± 0.56 mm; maximal stenosis: 49.0 ± 8.7%; minimal luminal diameter (MinimalLD): 1.48 ± 0.4 mm; mean luminal diameter (MeanLD): 2.3 ± 0.5 mm; mean lesion length: 28.7 ± 10.6 mm. Lesions with FFR <0.75 accounted for 33% (n = 35). Weak correlations were obtained between FFR and MinimalLD (r = 0.36; P < 0.0005), MeanLD (r = 0.24; P = 0.014), maximal stenosis (r = 0.31; P = 0.001), and mean stenosis (r = 0.018; P = 0.85); strong correlations were observed between FFR and lesion length (r = 0.63; P < 0.0005), lesion length/MinimalLD (r = 0.67; P < 0.0005), and lesion length/MeanLD (0.72; P < 0.0005). The predictive values of lesion length, lesion length/MinimalLD, and lesion length/MeanLD for FFR <0.75 were 0.86, 0.91, and 0.92, respectively.

Conclusions

In long lesions (>20 mm) with moderate angiographic stenosis, lesion length might be the strongest determinant of functional repercussion. Lesion length should be considered when judging the benefit of revascularization or perform functional functional measures that overcome the limitations of simple stenosis quantification. © 2012 Wiley Periodicals, Inc.
Liquid chromatographic resolution of 3‐amino‐1,4‐benzodiazepin‐2‐ones on crown ether‐based chiral stationary phases
Authors: Park Je Young , Jin Kab Bong , Hyun Myung Ho
Published: April 2012

3‐Amino‐5‐phenyl (or 5‐methyl)‐1,4‐benzodiazepin‐2‐ones, which are chiral precursors of anti‐respiratory syncytial virus active agents, were resolved on three different chiral stationary phases (CSPs) based on (+)‐(18‐crown‐6)‐2,3,11,12‐tetracarboxylic acid or (3,3′‐diphenyl‐1,1′‐binaphthyl)‐20‐crown‐6. Among the three CSPs, the CSP that is based on (3,3′‐diphenyl‐1,1′‐binaphthyl)‐20‐crown‐6 and containing residual silanol group‐protecting n‐octyl groups on the silica surface was found to be most effective with the use of 80% ethanol in water containing perchloric acid (10 mM) and ammonium acetate (1.0 mM) as a mobile phase. The separation factors (α) and resolutions (RS) were in the range of 1.90–3.21 and 2.79–5.96, respectively. From the relationship between the analyte structure and the chromatographic resolution behavior, the chiral recognition mechanism on the CSP based on (+)‐(18‐crown‐6)‐2,3,11,12‐tetracarboxylic acid was proposed to be different from that on the CSP based on (3,3′‐diphenyl‐1,1′‐binaphthyl)‐20‐crown‐6. In addition, the chromatographic resolution behavior of the most effective CSP was investigated as a function of the composition of aqueous mobile phase containing organic and acidic modifier and ammonium acetate. Chirality 24:427‐431, 2012. © 2012 Wiley Periodicals, Inc.
Manganese‐Enhanced MRI Contrast Agents: From Small Chelates to Nanosized Hybrids The Development of Iron(II) Complexes as ParaCEST MRI Contrast Agents Lanthanide Complexes as Paramagnetic Probes for 19F Magnetic Resonance The Solution Structure and Dynamics of MRI Probes Based on Lanthanide(III) DOTA as Investigated by DFT and NMR Spectroscopy (Eur. J. Inorg. Chem. 11/2012)
Authors: Kueny‐Stotz Marie , Felder‐Flesch Delphine , Morrow Janet R. , Parker David , Kuprov Ilya , Platas‐Iglesias Carlos
Published: April 2012

The cover picture highlights various aspects of research in the field of metal‐based MRI probes. The picture includes graphics from four Microreviews in this Cluster Issue superimposed on an angiographic MRI image. Shown at the bottom left is a macromolecular MnII complex (D. Felder‐Flesch, M. Kueny‐Stotz, and A. Garofalo), which is an example of manganese‐enhanced MRI contrast agents. At the bottom right, the optimization of the CEST effect for a FeII complex at close to physiological pH (J. R. Morrow and S. J. Dorazio) is depicted. Right next to it is a pseudocontact shift field around a model of a lanthanide–DOTA complex (D. Parker, I. Kuprov, and P. Harvey), illustrating the physicochemical basis of probe design for 19F MRS and MRI applications. At the top left is an energy diagram for the enantiomerization process of a LnIII complex with a cyclen‐based ligand (C. Platas‐Iglesias), which reflects an improved understanding of the solution structure and dynamics of such systems. The molecular modeling representation of a typical MRI contrast agent, [Gd(DOTA)(H2O)]–, is shown next to it. We thank the authors for providing graphics for the cover and Dr. Giorgio Gatti for putting in his time and creativity to compose this insightful picture.

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Synthesis of 2′,3′‐Dideoxy‐2′‐fluoro‐3′‐(hydroxyimino)‐, ‐3′‐(methoxyimino)‐ and ‐3′‐(hydroxyamino)pyrimidine Nucleosides
Authors: Khalil Ahmed , Mathé Christophe , Périgaud Christian
Published: April 2012

New series of 2′,3′‐dideoxy‐2′‐fluoro‐3′‐(hydroxyimino)‐, ‐3′‐(methoxyimino)‐ and ‐3′‐(hydroxyamino)pyrimidine nucleosides were synthesized. Structural assignments of the former two derivatives, which were obtained as inseparable mixtures of (E) and (Z) isomers, were based upon 1H and 19F NMR spectroscopic analysis. In particular, we observed striking differences in 19F NMR spectra resulting from through‐space N–F coupling for compounds having proximate nitrogen (oxime) and fluorine atoms with lone‐pairs correctly oriented for overlapping. Antiviral and cytotoxic activities of the target nucleosides were evaluated; however, none of them showed any antiviral activity. Only 2′,3′‐dideoxy‐2′‐fluoro‐3′‐(hydroxyamino)cytidine (19) showed moderate activity against the proliferation of murine leukemia cells (L1210).
Telecommunication e‐services orchestration enabling business process management
Authors: Chou Tung‐Hsiang , Seng Jia‐Lang
Published: April 2012

The Internet's widespread popularity and the ubiquity of the World Wide Web have revolutionized the face of business, especially in the telecommunications industry. With the emergence of business process management and of service‐oriented architecture, the focus has shifted to the development of electronic services that integrate business processes and that diversify functionalities available to customers. Most of these worldwide telecom corporations have many kinds of operations support systems in the backend environment. In this research, we present a research framework, a collaboration model and a collaboration layer to describe the method of new generation operations systems and software. This research method achieves the desired properties of telecom e‐services of business process management. Then, we use several illustrations to explain the generality of our method, and we focus on how international telecom corporations have become too concerned with the agility and the integration underlying e‐services integration based on new generation operations systems and software. Copyright © 2012 John Wiley & Sons, Ltd.
An assessment of particle methods for approximating anisotropic dispersion
Authors: Herrera Paulo A. , Beckie Roger D.
Published: April 2012

We derive a smoothed particle hydrodynamics (SPH) approximation for anisotropic dispersion that only depends upon the first derivative of the kernel function and study its numerical properties. In addition, we compare the performance of the newly derived SPH approximation versus an implementation of the particle strength exchange (PSE) method and a standard finite volume method for simulating multiple scenarios defined by different combinations of physical and numerical parameters. We show that, for regularly spaced particles, given an adequate selection of numerical parameters such as kernel function and smoothing length, the new SPH approximation is comparable with the PSE method in terms of convergence and accuracy and similar to the finite volume method. On other hand, the performance of both particle methods (SPH and PSE) decreases as the degree of disorder of the particle increases. However, we demonstrate that in these situations the accuracy and convergence properties of both particle methods can be improved by an adequate choice of some numerical parameters such as kernel core size and kernel function. Copyright © 2012 John Wiley & Sons, Ltd.
On Optimal Gene‐Based Analysis of Genome Scans
Authors: Bacanu Silviu‐Alin
Published: April 2012

Univariate analysis of markers has modest power when there are multiple causal variants within a gene. Under this scenario, combining the effects of all variants from a gene in a gene‐wide statistic is thought to increase power. However, it is not really clear (1) what is the performance of most commonly used gene‐wide methods for whole genome scans and (2) how scalable these methods are for more computationally intensive analyses, e.g. analysis of genome‐wide sequence data. We attempt to answer these questions by using realistic simulations to assess the performance of a range of gene‐based methods: (1) commonly used, e.g. VEGAS and GATES; (2) less commonly used, e.g. Simes, adaptive sum (aSUM), and kernel methods; and (3) a combination of univariate and multivariate tests we proposed for the analysis of markers in linkage disequilibrium. Simes is the fastest method and has good power for single causal variant models. aSUM method has good power for multiple causal variant models, especially at lower gene lengths. Our proposed statistic yields good power for all causal models. Given the extreme data volumes coming from sequencing studies, we recommend a two step analysis of genome scans. The initial step uses the very fast Simes procedure to flag possibly interesting genes. The second step refines interesting signals by using more computationally intensive methods, e.g. (1) aSUM for shorter and (2) VEGAS for larger gene lengths. Alternatively, genome scans can be analyzed using only our proposed method while sacrificing only a modest amount of power. Genet. Epidemiol. 36:333–339, 2012. © 2012 Wiley Periodicals, Inc.
Depressive symptoms among the medically hospitalized older individuals — a 1‐year follow‐up study
Authors: Helvik Anne‐Sofie , Engedal Knut , Selbæk Geir
Published: April 2012

Aim

The present follow‐up study of older medically hospitalized patients from a rural area in Norway assessed the prevalence of depressive symptoms at 1‐year follow‐up and furthermore explored whether depressive symptoms at follow‐up was associated with change in the medical, functional or emotional situation between baseline and follow‐up.

Methods

A 1‐year follow‐up study included 363 (175 men) older medical inpatients with age range 65–98 (mean = 80.2; standard deviation (SD) = 7.5) years. Information was collected at baseline and follow‐up using the Hospital Anxiety and Depression scale (HAD), the Mini‐Mental State Examination, Lawton and Brody's scales for physical self‐maintenance and performance of the instrumental activities of daily living.

Results

The prevalence of depressive symptoms, as defined by a score ≥ 8 at HAD‐D, was 10% at baseline and 7% at follow‐up. Of those with depressive symptoms at baseline, 78% had experienced remission. The incidence of depressive symptoms at follow‐up was 5%. In logistic regression analyses adjusted for age, gender, and depressive symptoms at baseline, becoming or being in need of assistance from nursing or social services (odds ratio (OR) = 8.1, 95% CI: 1.9–34.2 and OR = 4.4, 95% CI: 1.1–17.4, respectively), having a cognitive decline (OR = 1.1, 95% CI: 1.0–1.3), and exhibiting poorer physical self‐maintenance (OR = 1.2, 95% CI: 1.0–1.3), becoming vision impaired (OR = 8.3, 95% CI: 2.8–25.0), and with increased anxiety (OR = 1.2, 95% CI: 1.0–1.3) during follow‐up was associated with depressive symptoms at follow‐up.

Conclusion

The 1‐year follow‐up study of older medical inpatients contributes to the research body regarding risk factors of depression in older people. Copyright © 2012 John Wiley & Sons, Ltd.
Using Atom Transfer Radical Polymerization for the Synthesis of Grafted PVDF Copolymers towards the Synthesis of Membranes
Authors: Sermili Sarit , Eisen Moris S.
Published: April 2012

Graft copolymers of poly(vinylidene fluoride) (PVDF) with poly(3‐sulfopropyl methacrylic acid) (PVDF‐g‐PSPMA), poly(styrene‐4‐sulfonic acid) (PVDF‐g‐PSSA), and poly(dimethylaminoethyl methacrylate) (PDVFg‐PDMAEMA) were synthesized. The aforementioned grafted copolymers were prepared from the corresponding (PDVF‐g‐PSPMPS) poly(3‐sulfopropyl methacrylate potassium) and (PVDF‐g‐PSSS) poly(styrene‐4‐sulfonate sodium) salts using PVDF as a macroinitiator for atom transfer radical polymerization (ATRP). The copolymers were casted into membranes by the phase inversion method in aqueous media. The effects of polymerization time, degree of conversion, chain transfer agent (CTA) additive, crosslink process, and various solvents were investigated. The products were characterized by 1H and 13C NMR spectroscopy, IR spectroscopy, differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). The maximum grafting incorporation was up to 26, 20 and 20 wt % for PSSA, PSPMA and PDMAEMA, respectively. The incorporation was reduced using a CTA additive. The most impressive feature of the graft copolymer membranes produced in this study are the improved water fluxes and polyethylene glycol (PEG) rejection properties when compared to the commercially available, pristine PVDF.
The effect of conjugated spacer on novel carbazole derivatives for dye‐sensitized solar cells: Density functional theory/time‐dependent density functional theory study
Authors: Jungsuttiwong Siriporn , Yakhanthip Thanisorn , Surakhot Yaowarat , Khunchalee Janeeya , Sudyoadsuk Taweesak , Promarak Vinich , Kungwan Nawee , Namuangruk Supawadee
Published: April 2012

The ground‐state structure and frontier molecular orbital of D‐π‐A organic dyes, CFT1A, CFT2A, and CFT1PA were theoretically investigated using density functional theory (DFT) on B3LYP functional with 6‐31G(d,p) basis set. The vertical excitation energies and absorption spectra were obtained using time‐dependent DFT (TD‐DFT). The adsorptions of these dyes on TiO2 anatase (101) were carried out by using a 38[TiO2] cluster model using Perdew–Burke–Ernzerhof functional with the double numerical basis set with polarization (DNP). The results showed that the introduction of thiophene–thiophene unit (T–T) as conjugated spacer in CFT2A could affect the performance of intramolecular charge transfer significantly due to the inter‐ring torsion of T–T being decreased compared with phenylene–phenylene (P–P) spacer of CFP2A in the researhcers' previous report. It was also found that increasing the number of π‐conjugated unit gradually enhanced charge separation between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of these dyes, leading to a high‐efficiency photocurrent generation. The HOMO–LUMO energy gaps were calculated to be 2.51, 2.37, and 2.50 eV for CFT1A, CFT2A, and CFT1PA respectively. Moreover, the calculated adsorption energies of these dyes on TiO2 cluster were ∼14 kcal/mol, implying that these dyes strongly bind to TiO2 surface. Furthermore, the electronic HOMO and LUMO shapes of all dye–TiO2 complexes exhibited injection mechanism of electron via intermolecular charge‐transfer transition. © 2012 Wiley Periodicals, Inc.
Synthesis, Crystal Structure, Antioxidation and DNA‐Binding Studies of a Zinc(II) Complex with the Bis(N‐allylbenzimidazol‐2‐ylmethyl)aniline
Authors: Wu Huilu , Liu Bin , Kou Fan , Jia Fei , Yuan Jingkun , Bai Ying
Published: April 2012

A complex of zinc(II) picrate (pic) with bis(N‐allylbenzimidazol‐2‐ylmethyl)aniline (abba), with composition [Zn(abba)2](pic)2, was synthesized and characterized by elemental analysis, electrical conductivity, IR and UV/Vis spectral measurements. The crystal structure of the zinc(II) complex has been determined by single‐crystal X‐ray diffraction. The Zn(II) is bonded to two abba ligands through four benzimidazole nitrogen, resulting in a distorted tetrahedron geometry. The DNA‐binding properties of the ligand and the zinc(II) complex were investigated by electronic absorption, fluorescence spectra and viscosity measurements. The experimental results suggest that the zinc(II) complex binds to DNA in an intercalation mode. In addition, the ligand abba and Zn(II) complex have scavenging effects for hydroxyl radicals and the complex shows stronger scavenging effects for hydroxyl radicals than the ligand.
Surfactant Templated Silica Xerogels as Adsorbents for Rhodamine 6G
Authors: Pirzada Tahira , Shah Syed Sakhawat
Published: April 2012

A series of silica xerogels was synthesized by using TEOS as the silica precursor and a non ionic surfactant Triton X100 (TX100) and a cationic surfactant Hexadecyltrimethylammonium Bromide (CTAB) as templates. The xerogels were synthesized through 2‐way catalysis using ultrasonic radiations for homogeneous mixing of the precursors and template. The surfactant template was later removed through calcination at 550 °C. It was found out that gels having CTAB as the template had higher surface area (612.08 m2/g) than the gels templated by TX100 (539.6 m2/g). High surface area xerogels were used in adsorption experiments for aqueous solutions of Rhodamine 6G (R6G). UV visible spectroscopy was used to find out the concentrations of dye solutions. The adsorption data of both the types of xerogels was found to follow Freundlich's adsorption model pointing towards the possibility of adsorption of the dye molecules on the heterogeneous surface of the adsorbent.
BMP‐2 but not VEGF or PDGF in fibrin matrix supports bone healing in a delayed‐union rat model
Authors: Kaipel Martin , Schützenberger Sebastian , Schultz Arthur , Ferguson James , Slezak Paul , Morton Tatjana J. , Van Griensven Martijn , Redl Heinz
Published: April 2012

Treatment of delayed bone healing and non‐unions after fractures, osteotomies or arthrodesis still is a relevant clinical challenge. Artificially applied growth factors can increase bone healing and progressively gain importance in clinical routine. The aim of this study was to determine the effects of rhPDGF‐BB, rhVEGF‐165, and rhBMP‐2 in fibrin matrix on bone healing in a delayed‐union rat model. Thirty‐seven rats underwent a first operation where a standardized femoral critical size defect was created. A silicone spacer was implanted to impair vascularization within the defect. At 4 weeks the spacer was removed in a second operation and rhPDGF‐BB, rhVEGF‐165, or rhBMP‐2 were applied in a fibrin clot. Animals in a fourth group received a fibrin clot without growth factors. At 8 weeks fibrin bound rhBMP‐2 treated animals showed a significantly increased union rate and bone volume within the defect compared to the other groups. Single application of fibrin bound rhPDGF‐BB and rhVEGF‐165 failed to increase bone healing in our atrophic non‐union model. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1563–1569, 2012
Water quality under intensive banana production and extensive pastureland in tropical Mexico
Authors: Aryal Deb R. , Geissen Violette , Ponce‐Mendoza Alejandro , Ramos‐Reyes Rodimiro R. , Becker Mathias
Published: April 2012

The effects of intensive banana production with high mineral‐fertilizer application and of extensive pastures were compared regarding water quality in a lowland region of SE Mexico. We monitored NO$ _3^- $, NO$ _2^- $, and PO43– concentrations in groundwater (80 m depth), subsurface water (5 m depth), and surface water (open‐ditch drainage) at monthly intervals for a one‐year period. Irrespective of the land use, the NO$ _3^- $ concentrations in all water bodies were lower than the threshold value for drinking water and aquatic life. Particularly in areas with intense banana production, the NO$ _2^- $ contents in water exceeded the safety thresholds for drinking water of 1.0 mg L–1 (WHO, 2006) and aquatic ecosystems of 0.2 mg L–1 (OATA, 2008). Water from pastureland showed significantly higher PO43– concentration than that from the banana plantation, indicating a high risk of eutrophication. There is a need to provide recommendations for optimal time and amount of N application in commercial banana production and for limitation of P inputs in pasturelands to avoid further contamination of water bodies.
Micro‐encapsulation of refined olive oil: influence of capsule wall components and the addition of antioxidant additives on the shelf life and chemical alteration
Authors: Calvo Patricia , Castaño Ángel Luís , Lozano Mercedes , González‐Gómez David
Published: April 2012

BACKGROUND: Although refined olive oils (ROOs) exhibit lower quality and less stability toward thermal stress than extra‐virgin olive oils, these types of oil are gaining importance in the food industry. The inclusion of ROOs in processed food may alter the oxidative stability of the manufactured products, and therefore having technological alternatives to increase oil stability will be an important achievement. For this reason the main goal of this study was to assess the influence of the micro‐encapsulation process on the ROO chemical composition and its oxidative stability. Factors such as microcapsule wall constituents and the addition of the antioxidant butyl hydroxytoluene were investigated in order to establish the most appropriate conditions to ensure no alteration of the refined olive oil chemical characteristics.

RESULTS: The optimised methodology exhibited high encapsulation yield (>98%), with micro‐encapsulation efficiency ranging from 35 to 69% according to the nature of the wall components. The encapsulation process slightly altered the chemical composition of the olive oil and protected the oxidative stability for at least 11 months when protein components were included as wall components.

CONCLUSION: It was concluded that the presence of proteins constituents in the microcapsule wall material extended the shelf life of the micro‐encapsulated olive oil regardless the use of antioxidant additives. Copyright © 2012 Society of Chemical Industry
Performance analysis of flexible multirecess hydrostatic journal bearing operating with micropolar lubricant
Authors: Verma Suresh , Kumar Vijay , Gupta K. D.
Published: April 2012

This paper presents the analytical study of the effect of the bearing shell flexibility on the performance of multirecess hydrostatic journal bearing system operating with micropolar lubricant. The modified Reynolds equation for the flow of micropolar lubricant through constant flow valve‐compensated hydrostatic journal bearing has been solved by finite element technique based on Galerkins method, and the resulting elastic deformation in the bearing shell due to fluid‐film pressure has been determined iteratively, in which the deformation coefficient accounts for the bearing shell flexibility. The computed results suggest that the influence of the micropolar effect on bearing performance characteristics is significantly affected by the bearing shell flexibility. Copyright © 2012 John Wiley & Sons, Ltd.
Nanostructure Evolution Mechanisms During Slow Load‐Cycling of Oriented HDPE/PA Microfibrillar Blends as a Function of Composition
Authors: Zeinolebadi Ahmad , Stribeck Norbert , Ganjaee‐Sari Morteza , Dencheva Nadya , Denchev Zlatan , Botta Stephan
Published: April 2012

Oriented precursors of MFCs consisting of HDPE and PA6 or PA12 are studied during strain‐controlled slow load‐cycling. In the PA6‐containing blends a strongly retarded nanostrain response is detected. Compatibilization induces nanostrain heterogenization. Stress fatigue is lower in the PA12 blends, but hardly decreased by the compatibilizer. Selective migration of the compatibilizer into a disordered semi‐crystalline fraction of the HDPE matrix can explain the findings. The semi‐crystalline HDPE entities in PA6 blends appear more disordered than in PA12‐blends. An analysis of the HDPE nanostructure evolution during cycling reveals epitaxial strain crystallization. Uncompatibilized PA6 blends cycled about high pre‐strain show plastic flow but nanoscopic shrinkage in the semi‐crystalline stacks.

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A new phenotype of brain iron accumulation with dystonia, optic atrophy, and peripheral neuropathy
Authors: Horvath Rita , Holinski‐Feder Elke , Neeve Vivienne C.M. , Pyle Angela , Griffin Helen , Ashok Deephthi , Foley Charlotte , Hudson Gavin , Rautenstrauss PhD Bernd , Nürnberg Gudrun , Nürnberg Peter , Kortler Jörg , Neitzel Birgit , Bäßmann Ingelore , Rahman Thahira , Keavney Bernard , Loughlin John , Hambleton Sophie , Schoser Benedikt , Lochmüller Hanns , Santibanez‐Koref Mauro , Chinnery Patrick F.
Published: April 2012

Background:

Neurodegeneration with brain iron accumulation is clinically and genetically heterogeneous because of mutations in at least 7 nuclear genes.

Methods:

We performed homozygosity mapping and whole‐exome sequencing in 2 brothers with brain iron accumulation from a consanguineous family.

Results:

We identified a homozygous missense mutation in both brothers in the very recently identified chromosome 19 open‐reading frame 12 gene. The disease presented before age 10 with slowly progressive tremor, dystonia, and spasticity. Additional features were optic atrophy, peripheral neuropathy, and learning difficulties. A raised serum creatine kinase indicated neuromuscular involvement, and compensatory mitochondrial proliferation implicated mitochondrial dysfunction as a pathological mechanism.

Conclusions:

Further studies are needed to explore the function of the chromosome 19 open‐reading frame 12 gene, and extended genetic analysis on larger patient cohorts will provide more information about the presentation and frequency of this disease. © 2012 Movement Disorder Society
First trimester placental volume and three dimensional power doppler ultrasonography in type I diabetic pregnancies
Authors: Rizzo Giuseppe , Capponi Alessandra , Pietrolucci Maria Elena , Aiello Eloisa , Arduini Domenico
Published: April 2012

Objective

This study aimed to investigate the placental volume and three dimensional (3D) power Doppler vascularization in type I diabetic pregnancies during the first trimester

Methods

3D‐power Doppler ultrasonography of the placenta was performed at 11 + 0–13 + 6 weeks in 32 pregnancies complicated by type I diabetes. Placental volume, vascularization index (VI), flow index (FI), and vascularization flow index (VFI) were calculated using a standardized setting.

Results

In nine pregnancies, a poor first trimester glycemic control was present as expressed by HbA1c levels ≥ 7%, whereas in the remaining 23 mothers, the HbA1c concentrations were <7%. No differences were found in the placental volumes of diabetic mothers when compared with reference limits. 3D Doppler placental vascular indices were significantly higher in diabetic mothers (VI delta value 0.99, p = 0.0012; FI delta value 0.64, p = 0.0008; VFI delta value 1.28, p = 0.0039) when compared with reference limits. Pregnancies with HbA1c ≥7% exhibited higher placental vascular indices when compared with diabetic mothers with better glycemic control.

Conclusions

In type I diabetic mothers, placental vascular indices are increased and these modifications are more evident in pregnancies with poor first trimester glycemic control. © 2012 John Wiley & Sons, Ltd.
An algorithm to identify preterm infants in administrative claims data
Authors: Eworuke Efe , Hampp Christian , Saidi Arwa , Winterstein Almut G.
Published: April 2012

Purpose

To develop and validate an algorithm to identify preterm infants in the absence of birth certificates within Medicaid data.

Methods

Medicaid fee‐for‐service claims data from Florida (FL) and Texas (TX) were linked to vital statistics data for infants who were continuously eligible during the first 3 months following birth or died within that period. Prematurity was defined as less than 34 weeks gestational age. Using FL as exploratory dataset and vital statistics birth data as gold standard, we developed a logistic regression model from diagnostic and procedure codes commonly associated with preterm care, creating a prematurity score for each infant. A score cutoff was selected that maximized sensitivity while maintaining a positive predictive value (PPV) ≥ 90%. Confirmatory analyses were conducted in the TX datasets.

Results

The prevalence of prematurity was 5.2% (95%CI: 5.1–5.2) and 4.5% (95%CI: 4.4–4.6) in FL and TX, respectively. Using only gestational age International Classification of Disease version 9, Clinical Modification (ICD‐9‐CM) codes (765.20–765.27) associated with inpatient claims achieved sensitivity of 25.7% (FL) and 12.5% (TX), specificity of 99.9% (FL) and (TX), and PPV of 91.7% (FL) and 84.8% (TX). The model had excellent discriminatory validity with a c‐statistic of 0.928 (95%CI: 0.925–0.931). The selected cutoff point achieved sensitivity of 52.6%, specificity of 99.8%, and PPV of 91.7% in FL. In TX, sensitivity was 46.8%, specificity was 99.9%, and PPV was 82.2%.

Conclusion

Identification of prematurity based on gestational age ICD‐9‐CM codes is not sensitive. The prematurity score has superior construct validity and allows more comprehensive identification of preterm infants in the absence of birth certificates. Copyright © 2012 John Wiley & Sons, Ltd.
Synthesis and characterization of a multiarm poly(acrylic acid) star polymer for application in sustained delivery of cisplatin and a nitric oxide prodrug
Authors: Duan Shaofeng , Cai Shuang , Xie Yumei , Bagby Taryn , Ren Shenqiang , Forrest M. Laird
Published: April 2012

Functionalized polymeric nanocarriers have been recognized as drug delivery platforms for delivering therapeutic concentrations of chemotherapies. Of this category, star‐shaped multiarm polymers are emerging candidates for targeted delivery of anticancer drugs, due to their compact structure, narrow size distribution, large surface area, and high water solubility. In this study, we synthesized a multiarm poly(acrylic acid) star polymer via macromolecular design via the interchange (MADIX)/reversible addition fragmentation chain transfer (MADIX/RAFT) polymerization and characterized it using nuclear magnetic resonance (NMR) and size exclusion chromatography. The poly(acrylic acid) star polymer demonstrated excellent water solubility and extremely low viscosity, making it highly suited for targeted drug delivery. Subsequently, we selected a hydrophilic drug, cisplatin, and a hydrophobic nitric oxide (NO)‐donating prodrug, O2‐(2,4‐dinitrophenyl) 1‐[4‐(2‐hydroxy)ethyl]‐3‐methylpiperazin‐1‐yl]diazen‐1‐ium‐1,2‐diolate, as two model compounds to evaluate the feasibility of using poly(acrylic acid) star polymers for the delivery of chemotherapeutics. After synthesizing and characterizing two poly(acrylic acid) star polymer‐based nanoconjugates, poly(acrylic acid)–cisplatin (acid–Pt) and poly(acrylic acid–NO (acid–NO) prodrug, the in vitro drug release kinetics of both the acid–Pt and the acid–NO were determined at physiological conditions. In summary, we have designed and evaluated a polymeric nanocarrier for sustained‐delivery of chemotherapies, either as a single treatment or a combination therapy regimen. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Unitary perturbation theory applied to multiconfigurational reference functions
Authors: Nagy Péter R. , Szabados Ágnes
Published: April 2012

Unitary parametrization of the wave operator in the form suggested by Mayer is studied in the multireference framework. The investigated unitary perturbation theory (UPT) constructs a first correction in terms of the functions having nonzero interaction with the reference state via the Hamiltonian. Parameters in the exponential of the wave operator are determined by two dimensional eigenvalue equations. Because of the unitary mapping, UPT is unaffected by the quasi‐degeneracy problem, making it an ideal tool for correcting multireference starting functions. Lack of size‐consistency is however a shortcoming of the method. Applications of UPT as well as the related degeneracy‐corrected PT (DCPT) are presented on intruder prone examples like the symmetric dissociation of the water molecule, the BeH2 system and the two lowest lying states of the scandium dimer. Size consistency violation is analysed and evaluated on the example of the water dimer. Tractability of excited states by UPT is examined by computing the singlet–triplet splitting of the CH2 molecule. © 2012 Wiley Periodicals, Inc.
Effects of the flow rate of O2 annealing ambient on structural and electrical properties of n+ emitter junctions formed using screen‐printed phosphorus diffusion process
Authors: Kim Jin‐Sung , Yun Hyung‐Joong , Seo Min‐Woo , Janardhanam V. , Ahn Kwang‐Soon , Choi Chel‐Jong
Published: April 2012

We have investigated the effects of the flow rate of O2 annealing ambient on the structural and electrical properties of the emitters with n+/p junctions formed using the screen printing of phosphorus (P) dopant paste, followed by O2 annealing. The reaction between P‐paste and Si led to the formation of phosphorus silicate glass layer, of which P atoms were mostly segregated in surface and interface regions. The sheet resistance of the screen‐printed n+ emitters formed under O2 flow rate of 5 l/min (LPM) was lower than that of 1 LPM. The recombination mechanism dominated the current transport in the forward bias regions of the screen‐printed n+ emitter, regardless of O2 flow rate. The n+ emitter formed under O2 flow rates of 5 LPM exhibited better rectification behavior with low reverse leakage, as compared with that of 1 LPM. The formation of thicker phosphorus silicate glass film caused by the increase in the O2 flow rate resulted in the increase in the equilibrium concentration of Si interstitials in bulk Si and provided more P atoms being incorporated in n+/p emitter junction. The increases in maximum concentration of P atoms and junction depth caused by the increase in the O2 flow rate could be responsible for superior junction quality of n+ emitter formed under O2 flow rates of 5 LPM. Copyright © 2012 John Wiley & Sons, Ltd.
Stress and stem cells
Authors: Tower John
Published: April 2012

The unique properties and functions of stem cells make them particularly susceptible to stresses and also lead to their regulation by stress. Stem cell division must respond to the demand to replenish cells during normal tissue turnover as well as in response to damage. Oxidative stress, mechanical stress, growth factors, and cytokines signal stem cell division and differentiation. Many of the conserved pathways regulating stem cell self‐renewal and differentiation are also stress‐response pathways. The long life span and division potential of stem cells create a propensity for transformation (cancer) and specific stress responses such as apoptosis and senescence act as antitumor mechanisms. Quiescence regulated by CDK inhibitors and a hypoxic niche regulated by FOXO transcription factor function to reduce stress for several types of stem cells to facilitate long‐term maintenance. Aging is a particularly relevant stress for stem cells, because repeated demands on stem cell function over the life span can have cumulative cell‐autonomous effects including epigenetic dysregulation, mutations, and telomere erosion. In addition, aging of the organism impairs function of the stem cell niche and systemic signals, including chronic inflammation and oxidative stress. WIREs Dev Biol 2012 doi: 10.1002/wdev.56

This article is categorized under:

Adult Stem Cells, Tissue Renewal, and Regeneration > Stem Cells and Disease

Adult Stem Cells, Tissue Renewal, and Regeneration > Environmental Control of Stem Cells

Adult Stem Cells, Tissue Renewal, and Regeneration > Stem Cells and Aging
Production host selection for asymmetric styrene epoxidation: Escherichia coli vs. solvent-tolerant Pseudomonas
Authors: Kuhn Daniel , Bühler Bruno , Schmid Andreas
Published: April 2012

Selection of the ideal microbe is crucial for whole-cell biotransformations, especially if the target reaction intensively interacts with host cell functions. Asymmetric styrene epoxidation is an example of a reaction which is strongly dependent on the host cell owing to its requirement for efficient cofactor regeneration and stable expression of the styrene monooxygenase genes styAB. On the other hand, styrene epoxidation affects the whole-cell biocatalyst, because it involves toxic substrate and products besides the burden of additional (recombinant) enzyme synthesis. With the aim to compare two fundamentally different strain engineering strategies, asymmetric styrene epoxidation by StyAB was investigated using the engineered wild-type strain Pseudomonas sp. strain VLB120ΔC, a styrene oxide isomerase (StyC) knockout strain able to accumulate (S)-styrene oxide, and recombinant E. coli JM101 carrying styAB on the plasmid pSPZ10. Their performance was analyzed during fed-batch cultivation in two-liquid phase biotransformations with respect to specific activity, volumetric productivity, product titer, tolerance of toxic substrate and products, by-product formation, and product yield on glucose. Thereby, Pseudomonas sp. strain VLB120ΔC proved its great potential by tolerating high styrene oxide concentrations and by the absence of by-product formation. The E. coli-based catalyst, however, showed higher specific activities and better yields on glucose. The results not only show the importance but also the complexity of host cell selection and engineering. Finding the optimal strain engineering strategy requires profound understanding of bioprocess and biocatalyst operation. In this respect, a possible negative influence of solvent tolerance on yield and activity is discussed.