bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of ruthenium anticancer agents by MEEKC‐UV and MEEKC–ICP‐MS: Impact of structural motifs on lipophilicity and biological activity
Authors: Giringer Kai , Holtkamp Hannah U. , Movassaghi Sanam , Tremlett William D. J. , Lam Nelson Y. S. , Kubanik Mario , Hartinger Christian G.
Published: February 2018

We present here the first comprehensive study on the lipophilicity of ruthenium anticancer agents encompassing compounds with broad structural diversity, ranging from octahedral RuIII(azole) through to RuII(arene) complexes. MEEKC was used to determine the capacity factors of the Ru complexes, and after a complex peak was unambiguously assigned using MEEKC–ICP‐MS, the results were validated through comparison with the log P determined by octanol/water partitioning experiments. Correlation of the two data sets demonstrated a close relationship despite the limited structural overlap of the compounds studied. The capacity factors found by MEEKC allowed for the clustering of complexes based on their structure and this could be used to rationalize the observed cytotoxicity in the human colon carcinoma HCT116 cell line. It was demonstrated that rather than modification of the mono‐ or bidentate coordinated ligands much tighter control over a complexes lipophilic properties could be achieved through modification of the Ru(arene) ligand, with minimal detriment to cytotoxicity. This demonstrates the flexibility and potential of the Ru piano‐stool scaffold. MEEKC proved to be a highly efficient means of screening the anticancer potential of preclinical ruthenium complex candidates for their lipophilic properties and correlate them with their biological activity and structural properties.
Recapitulating the clinical scenario of BRCA‐associated pancreatic cancer in pre‐clinical models
Authors: Golan Talia , Stossel Chani , Atias Dikla , Buzhor Ella , Halperin Sharon , Cohen Keren , Raitses‐Gurevich Maria , Glick Yulia , Raskin Stephen , Yehuda Daniel , Feldman Anna , Schvimer Michael , Friedman Eitan , Karni Rotem , Wilson Julie M. , Denroche Robert E. , Lungu Ilinca , Bartlett John M.S. , Mbabaali Faridah , Gallinger Steven , Berger Raanan
Published: February 2018

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies. BRCA‐associated PDAC comprises a clinically relevant subtype. A portion of these patients are highly susceptible to DNA damaging therapeutics, however, responses are heterogeneous and clinical resistance evolves. We have developed unique patient‐derived xenograft (PDX) models from metastatic lesions of germline BRCA‐mutated patients obtained at distinct time points; before treatment and at progression. Thus, closely mimicking clinical scenarios, to further investigate treatment naïve and resistant patients. DNA was isolated from six BRCA‐mutated PDXs and classified by whole‐genome sequencing to stable‐genome or homologous recombination deficient (HRD)‐genome. The sensitivity to DNA‐damaging agents was evaluated in vivo in three BRCA‐associated PDAC PDXs models: (1) HRD‐genome naïve to treatments; (2) stable‐genome naïve to treatment; (3) HRD‐genome resistant to treatment. Correlation between disease course at tissue acquisition and response to PARP inhibitor (PARPi)/platinum was demonstrated in PDXs in vivo. Only the HRD‐genome PDX, naïve to treatment, was sensitive to PARP inhibitor/cisplatin treatments. Our results demonstrate heterogeneous responses to DNA damaging agents/PARPi in BRCA‐associated PDX thus reflecting the wide clinical spectrum. An HRD‐genome PDX generated from a naïve to treatment biopsy was sensitive to platinum/PARPi whereas no benefit was observed in treating a HRD‐genome PDXs generated from a patient that had acquired resistance nor stable‐genome PDXs.
Three‐dimensional plotted alginate fibers embedded with diclofenac and bone cells coated with chitosan for bone regeneration during inflammation
Authors: Lin Hsin‐Yi , Chang Tsang‐Wen , Peng Tie‐Kun
Published: February 2018

Alginate hydrogel fibers embedded with bone cells and diclofenac were coated with a layer of chitosan hydrogel and made into a porous scaffold by three‐dimensional (3D) printing for drug release and bone regeneration. It was hypothesized that the chitosan coating could improve the scaffold's drug retention and release properties and biocompatibility. Macrophage cells were stimulated and cocultured with the scaffold. Tests were conducted to show how the chitosan coating affected the scaffold's drug release efficacy and how the release efficacy affected the cellular activities of stimulated macrophages and bone cells. The bone cells encapsulated in the coated scaffold demonstrated good viability after the acidic/basic coating process. The coating improved the retention and release efficacy of diclofenac and hence significantly inhibited interleukin‐6 and tumor necrosis factor‐α secretion from macrophages (p < 0.05). The bone cells in the coated sample mineralized more extensively than the control (p < 0.01). They also more actively expressed genes that produce proteins for extracellular matrix remodeling, MMP13, and interacting with the mineral matrix, OPN (both p < 0.01). It is believed that on days 7 and 10, when diclofenac was depleted and the concentrations of inflammatory compounds surged, the coating effectively blocked the harmful compounds and protected the bone cells within the fibers. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1511–1521, 2018.
A thermoresponsive, citrate‐based macromolecule for bone regenerative engineering
Authors: Morochnik Simona , Zhu Yunxiao , Duan Chongwen , Cai Michelle , Reid Russell R. , He Tong‐Chuan , Koh Jason , Szleifer Igal , Ameer Guillermo A.
Published: February 2018

There is a need in orthopaedic and craniomaxillofacial surgeries for materials that are easy to handle and apply to a surgical site, can fill and fully conform to the bone defect, and can promote the formation of new bone tissue. Thermoresponsive polymers that undergo liquid to gel transition at physiological temperature can potentially be used to meet these handling and shape‐conforming requirements. However, there are no reports on their capacity to induce in vivo bone formation. The objective of this research was to investigate whether the functionalization of the thermoresponsive, antioxidant macromolecule poly(poly‐ethyleneglycol citrate‐co‐N‐isopropylacrylamide) (PPCN), with strontium, phosphate, and/or the cyclic RGD peptide would render it a hydrogel with osteoinductive properties. We show that all formulations of functionalized PPCN retain thermoresponsive properties and can induce osteodifferentiation of human mesenchymal stem cells without the need for exogenous osteogenic supplements. PPCN‐Sr was the most osteoinductive formulation in vitro and produced robust localized mineralization and osteogenesis in subcutaneous and intramuscular tissue in a mouse model. Strontium was not detected in any of the major organs. Our results support the use of functionalized PPCN as a valuable tool for the recruitment, survival, and differentiation of cells critical to the development of new bone and the induction of bone formation in vivo. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1743–1752, 2018.
Automated error control in divide‐and‐conquer self‐consistent field calculations
Authors: Kobayashi Masato , Fujimori Toshikazu , Taketsugu Tetsuya
Published: February 2018

In linear‐scaling divide‐and‐conquer (DC) electronic structure calculations, a buffer region is used to control the error introduced by the DC approximation. In this study, an energy‐based error estimation scheme is proposed for the DC self‐consistent field method with a two‐layer buffer region scheme. Based on this scheme, a procedure to automatically determine the appropriate buffer region in the DC method is proposed. It was confirmed that the present method works satisfactorily in calculations of water clusters and proteins, although its performance was insufficient for the calculation of a delocalized graphene system. © 2018 Wiley Periodicals, Inc.
Hydride‐Triel Bonds
Authors: Jabłoński Mirosław
Published: February 2018

In this article, we present the results of our comprehensive studies of 72 dimers of thetype (X = Si, Ge; Y = B, Al, Ga; RX = H, Cl, Me; RY = H, F, Cl, Me) and featuring hydride‐triel bonds (i.e., charge‐inverted hydrogen bonds). Influence of X and Y atoms as well as RXand RYsubstituents on various properties of these dimers is investigated in detail. In particular the strength of the H⋯Y hydride‐triel bonds is paid a close attention and it is shown that hydride‐triel bonds can be strong enough to considerably determine structure and properties of molecular systems. In addition, properties of the investigated dimers are largely governed by the charge transfer from the Lewis base to the Lewis acid, which is particularly important if more bulky and polarizable RYand Y atoms are present in themolecule. Several excellent linear (R2close to 1) and exponential correlations between pairs of diverse parameters are presented. Few instances are discussed where somewhat unexpected bond paths exist between two atoms featuring partial negative charges (e.g., between hydride hydrogen and halogen and between lateral sides of two halogens) showing that in some cases a bond path prefers to link two closely spaced electron‐rich atoms instead of two atoms that are expected to form a bond. © 2018 Wiley Periodicals, Inc.
Genetic and phenotypic characterizations of drug‐resistant Mycobacterium tuberculosis isolates in Cheonan, Korea
Authors: Jeon Jae‐Sik , Kim Jae Kyung , Choi Qute , Kim Jong Wan
Published: February 2018

Background

Mycobacterium tuberculosis (MTB) causes tuberculosis (TB), which is a fatal disease. Cases of drug‐resistant MTB have increased in recent years. In this study, we analyzed 7 sites of MTB DNA sequences, including the rpoB and inhA gene, to investigate the relationship between gene mutations and drug resistance in MTB.

Methods

Mycobacterium tuberculosis liquid culture samples (197 specimens from 74 cases) were collected between June 2015 and May 2016 and sequenced. The results were compared with those obtained from antibiotic susceptibility tests.

Results

In 65 (87.8%) cases, the antibiotic‐resistant phenotype was consistent with genotyping results, whereas in 9 (12.2%) cases, there was no match. Eight mutations were detected in the rpoB gene, which showed the highest mutation rate. Sequencing results indicated that these mutations were present in 12 cases.

Conclusion

Previously published data on antibiotic resistance genes are insufficient for effective prevention of multidrug‐ or extensive drug‐resistant TB. Additional studies are needed to characterize the complement of antibiotic resistance genes in MTB.
A Self‐Regulatory Model of Resource Scarcity
Authors: Cannon Christopher , Goldsmith Kelly , Roux Caroline
Published: February 2018

Academics have shown a growing interest in the effects of resource scarcity—a discrepancy between one's current resource levels and a higher, more desirable reference point. However, the existing literature lacks an overarching theory to explain the breadth of findings across different types of resources. To address this, we introduce a self‐regulatory model of resource scarcity. In it, we propose that consumers respond to resource scarcity through two distinct psychological pathways: a scarcity‐reduction route aimed at reducing the discrepancy in resources and a control‐restoration route aimed at reestablishing diminished personal control by attaining security in other domains. We explain how a key determinant of which route the consumer will pursue is the perceived mutability of the resource discrepancy. We also specify moderators, based on our proposed model, to identify when each of the two routes is pursued. This model is assessed in the context of alternative theoretical perspectives, including commodity theory, life history theory, and models of compensatory behavior. Finally, we provide a research agenda for those interested in studying the psychology of resource scarcity from a self‐regulatory perspective.
Recombinant type Human mastadenovirus D85 associated with epidemic keratoconjunctivitis since 2015 in Japan
Authors: Hashimoto Shintaro , Gonzalez Gabriel , Harada Seiya , Oosako Hideo , Hanaoka Nozomu , Hinokuma Rikutaro , Fujimoto Tsuguto
Published: February 2018

The aim of this study was to report the emergence of a recombinant human mastadenovirus (HAdV) type 85 (HAdV‐85) and to describe its genomic and clinical characteristics. The strains were detected and identified in Japan in cases of adenoviral conjunctivitis including epidemic keratoconjunctivitis (EKC). The type was designated as HAdV‐85 based on the novel combination of penton base (P = HAdV‐37), hexon (H = HAdV‐19), and fiber (F = HAdV‐8). The whole genome sequence determined for HAdV‐85 was compared against sequences of other types in the same species. The results of the phylogenetic analysis suggested a recombinant origin between HAdV‐53 and HAdV‐64, which have been two major causes of adenoviral EKC in Japan over the past decade. During the period between 2008 and 2016 in Kumamoto city, southwest of Japan, 311 cases diagnosed with conjunctivitis were diagnosed as being the consequence of adenoviral infections. Among them, 11 cases were determined to have been caused by HAdV‐85 since 2015. Thus, HAdV‐85 could be an emerging causative agent of adenoviral conjunctivitis.
Alterations in natural killer and dendritic cell subsets in individuals with HIV‐associated neurotuberculosis
Authors: Rao Deepashri , Venkataswamy Manjunatha M. , Vasanthapuram Ravi , Satishchandra Parthasarathy , Desai Anita
Published: February 2018

One of the commonest HIV‐associated opportunistic infections of the central nervous system is neurotuberculosis. Interaction between HIV,Mycobacterium tuberculosisand host immune system in co‐infected individuals may result in altered frequencies of immune cells, thereby modulating dissemination and disease progression. We examined the frequencies of natural killer (NK) cell and dendritic cell (DC) subsets in HIV infected individuals with neurotuberculosis (HIVNTB) as compared to individuals with HIV associated systemic TB (HIVSTB), asymptomatic HIV, non‐HIV NTB, non‐HIV STB, and healthy controls. Peripheral blood mononuclear cells (PBMC) were stained with fluorochrome‐conjugated monoclonal antibodies‐ Lineage cocktail (containing CD3, CD14, CD19, and CD20), HLA‐DR, CD16, CD56, CD11c, and CD123, fixed with 2% paraformaldehyde and analyzed on the flow cytometer. The pDCs were significantly reduced in all HIV infected groups, with a marked reduction in HIVNTB cases as compared to healthy controls. While the CD56‐CD16btNK cell subset displayed a significant increase in frequency in all three HIV infected groups compared the three HIV negative groups, the CD56dimCD16btsubset was significantly lower in frequency in the HIVNTB compared to healthy controls. The decreased frequencies of plasmacytoid DCs and cytotoxic NK cells, which are crucial for innate immune defence against HIV, may result in ineffective virus control and lead to an exacerbated course of disease in HIVNTB individuals.
A plausible atmospheric trigger for the 2017 coastal El Niño
Authors: Garreaud René D.
Published: February 2018

The far eastern tropical Pacific experienced a rapid, marked warming in early 2017, causing torrential rains along the west coast of South America with a significant societal toll in Peru and Ecuador. This strong coastal El Niño was largely unpredicted, even a few weeks before its onset, and it developed differently from either central or eastern events. Here we provide an overview of the event, its impacts and concomitant atmospheric circulation. It is proposed that a remotely forced, sustained weakening of the free tropospheric westerly flow impinging the subtropical Andes leads to a relaxation of the southeasterly (SE) trades off the coast, which in turn may have warmed the eastern Pacific throughout the weakening of upwelling in a near‐coastal band and the lessening of the evaporative cooling farther offshore.
Thermoplastic Polyurethane Elastomers with Aliphatic Hard Segments Based on Plant‐Oil‐Derived Long‐Chain Diisocyanates
Authors: Schemmer Brigitta , Kronenbitter Cathrin , Mecking Stefan
Published: February 2018

Novel plant‐oil‐derived long‐chain (C19 and C23) α,ω‐diisocyanates, optionally in combination with the corresponding long‐chain diols, provide entirely aliphatic hard segments in segmented thermoplastic polyurethane elastomers (TPUs), with carbohydrate‐based poly(trimethylene glycol) soft segments. Compared to materials based on a mid‐chain monomer analog, phase separation is higher due to an increased flexibility of the aliphatic segments. Although melting points are slightly lower than for HDPE, the long‐chain TPU's solid‐state structure is still dominated by hydrogen‐bonding.
Medium Resolution 1H‐NMR at 62 MHz as a New Chemically Sensitive Online Detector for Size‐Exclusion Chromatography (SEC–NMR)
Authors: Höpfner Johannes , Ratzsch Karl‐Friedrich , Botha Carlo , Wilhelm Manfred
Published: February 2018

A state‐of‐the‐art, medium‐resolution 1H‐NMR spectrometer (62 MHz) is used as a chemically sensitive online detector for size‐exclusion chromatography of polymers such as polymethylmethacrylate (PMMA) and polystyrene (PS). The method uses protonated eluents and works at typical chromatographic conditions with trace amounts of analytes (<0.5 g L−1 after separation). Strong solvent suppression, e.g., by a factor of 500, is achieved by means of T1‐filtering and mathematical subtraction methods. Substantial improvements are made with respect to previous work in terms of the sensitivity (signal‐to‐noise ratio up to 130:1, PMMA OCH3) and selectivity (peak width, full width half maximum (FWHM) 4 Hz on‐flow). Typical homopolymers and a blend are investigated to deformulate their composition along the dimensions of molecular weight and NMR chemical shift. These results validate this new hyphenated chromatography method, which can greatly facilitate analysis and is much more effective than previously published results.
Hydrogen Bond Induces Hierarchical Self‐Assembly in Liquid‐Crystalline Block Copolymers
Authors: Huang Shuai , Pang Linlin , Chen Yuxuan , Zhou Liming , Fang Shaoming , Yu Haifeng
Published: February 2018

Microphase‐separated structures of block copolymers (BCs) with a size of sub‐10 nm are usually obtained by hydrogen‐bond‐induced self‐assembly of BCs through doping with small molecules as functional additives. Here, fabrication of hierarchically self‐assembled sub‐10 nm structures upon microphase separation of amphiphilic liquid‐crystalline BCs (LCBCs) at the existence of hydrogen bonds but without any dopants is reported. The newly introduced urethane groups in the side chain of the hydrophobic block of LCBCs interact with the ether groups of the hydrophilic poly(ethylene oxide) (PEO) block, leading to imperfect crystallization of the PEO blocks. Both crystalline and amorphous domains coexist in the separated PEO phase, enabling a lamellar structure to appear inside the PEO nanocylinders. This provides an elegant method to fabricate controllable sub‐10 nm microstructures in well‐defined polymer systems without the introduction of any dopants.
The GNAT: A new tool for processing NMR data
Authors: Castañar Laura , Poggetto Guilherme Dal , Colbourne Adam A. , Morris Gareth A. , Nilsson Mathias
Published: February 2018

The GNAT (General NMR Analysis Toolbox) is a free and open‐source software package for processing, visualising, and analysing NMR data. It supersedes the popular DOSY Toolbox, which has a narrower focus on diffusion NMR. Data import of most common formats from the major NMR platforms is supported, as well as a GNAT generic format. Key basic processing of NMR data (e.g., Fourier transformation, baseline correction, and phasing) is catered for within the program, as well as more advanced techniques (e.g., reference deconvolution and pure shift FID reconstruction). Analysis tools include DOSY and SCORE for diffusion data, ROSY T1/T2 estimation for relaxation data, and PARAFAC for multilinear analysis. The GNAT is written for the MATLAB® language and comes with a user‐friendly graphical user interface. The standard version is intended to run with a MATLAB installation, but completely free‐standing compiled versions for Windows, Mac, and Linux are also freely available.
Cross‐linked poly(aryl ether sulfone) membranes for direct methanol fuel cell applications
Authors: Yılmaz Esra , Can Erde
Published: February 2018

Partially sulfonated poly(aryl ether sulfone) (PESS) was synthesized and methacrylated via reaction with glycidyl methacrylate (PESSGMA) and cross‐linked via radical polymerization with styrene and vinyl‐phosphonic acid (VPA). The chemical structures of the synthesized pre‐polymers were characterized via FTIR and 1H NMR spectroscopic methods and molecular weight was determined via GPC. Membranes of these polymers were prepared via solution casting method. The crosslinking of the PESS polymer reduced IEC, proton conductivity, swelling in water, and methanol permeability of the membranes while increasing the modulus and the glass transition temperature. However, the introduction of the VPA comonomer increased the proton conductivity while maintaining excellent resistance to methanol cross‐over, which was significantly higher as compared with both PESS and the commercial Nafion membranes. Membranes of PESSGMA copolymers incorporating VPA, exhibited proton conductivity values at 60 °C in the range of 16–32 mS cm−1 and methanol permeability values in the range of 6.52 × 10−9 – 1.92 × 10−8 cm2 s−1. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018, 56, 558–575
Preparation of Macroporous Mn3O4 Microspheres via Thermal Decomposition in Water Vapor
Authors: Kozawa Takahiro
Published: February 2018

Macroporous materials are in constant demand for use in environmental purification filters. Although the preparation of porous materials by a thermal decomposition route without templates and surfactants is simple, low‐cost, and scalable, the pore size of the resulting materials is limited to micropore or mesopore regions. Herein, I report the preparation of macroporous Mn3O4 microspheres from MnCO3 spheres via thermal decomposition in water vapor. The accelerated decomposition of MnCO3 by water vapor facilitates vermicular growth of Mn3O4 primary particles at a low temperature, leading to the formation of a maze‐like pore structure. The characteristic microstructure of macroporous Mn3O4 microspheres exhibits nanoparticle capture properties and inherited its pore structure of Mn3O4 during conversion to Mn2O3 by reheating. This study reveals new possibilities for the application of the thermal decomposition method to prepare macroporous particles.
Penne‐Like MoS2/Carbon Nanocomposite as Anode for Sodium‐Ion‐Based Dual‐Ion Battery
Authors: Zhu Haili , Zhang Fan , Li Jinrui , Tang Yongbing
Published: February 2018

The dual‐ion battery (DIB) system has attracted great attention owing to its merits of low cost, high energy, and environmental friendliness. However, the DIBs based on sodium‐ion electrolytes are seldom reported due to the lack of appropriate anode materials for reversible Na+ insertion/extraction. Herein, a new sodium‐ion based DIB named as MoS2/C‐G DIB using penne‐like MoS2/C nanotube as anode and expanded graphite as cathode is constructed and optimized for the first time. The hierarchical MoS2/C nanotube provides expanded (002) interlayer spacing of 2H‐MoS2, which facilitates fast Na+ insertion/extraction reaction kinetics, thus contributing to improved DIB performance. The MoS2/C‐G DIB delivers a reversible capacity of 65 mA h g−1 at 2 C in the voltage window of 1.0–4.0 V, with good cycling performance for 200 cycles and 85% capacity retention, indicating the feasibility of potential applications for sodium‐ion based DIBs.
Effect of Acetylation and Beta‐Amylase Treatment on Complexation of Debranched Starch with Naringenin
Authors: Gonzalez Ana , Wang Ya‐Jane , Staroszczyk Hanna , Brownmiller Cindi , Lee Sun‐Ok
Published: February 2018

Starch inclusion complexation has been shown to improve solubility of water insoluble molecules. Potato starch and Hylon VII are acetylated at two levels and then debranched alone or combined with β‐amylase hydrolysis, and its complexes with naringenin are prepared in aqueous conditions and characterized in this study. Both soluble and insoluble complexes are formed with the soluble complex present in the supernatant and the insoluble complex as the precipitate after centrifugation. The recovery of the soluble complexes and the naringenin content increased when starch is acetylated, and further increased when the β‐amylase treatment is included. The naringenin contents in both complexes from Hylon VII are significantly greater than those from potato starch regardless of treatments. The insoluble complexes comprise a greater naringenin content than the soluble counterparts for both starches. FTIR spectra and thermal properties by differential scanning calorimetry confirm the molecular interaction between starch and naringenin for both complexes. This work is the first to demonstrate that starch derivatives form complexes with naringenin, and both acetylation and the beta‐amylase treatment improve their complexation.
Carboxymethylation of Plasticized Starch by Reactive Extrusion (REX) with High Reaction Efficiency
Authors: Milotskyi Romain , Bliard Christophe
Published: February 2018

Carboxymethyl potato starches with degrees of substitution (DS) of 0.15–0.64 are synthesized in one step and in high levels of reaction efficiency (RE) using reactive extrusion processes on plasticized starch. The influence of process parameters such as screw geometry, specific mechanical energy (SME), temperature, and residence time on DS, RE and crystallinity are determined. SME have a surprisingly greater influence than the reaction time on RE. Up to 64% RE is reached with high values of SME (297 kJ kg−1). SME also have a major impact on starch chain degradation. The co‐rotating screw geometry have a positive influence on the RE. The temperature is found to have no effect on the reaction in the 90–120 °C range. Two types of malto‐dextrins are successfully used as alternative plasticizers for starch. The carboxymethylated starches are characterized using nuclear magnetic resonance spectroscopy, size exclusion chromatography, and X‐ray diffraction. This study shows that starch can be efficiently carboxymethylated in a plasticized medium with high RE using different plasticizers in very short reaction times.
Fine Tuning of Canonical Wnt Stimulation Enhances Differentiation of Pluripotent Stem Cells Independent of β-Catenin-Mediated T-Cell Factor Signaling
Authors: Chen Joseph , Nefzger Christian M. , Rossello Fernando J. , Sun Yu B.Y. , Lim Sue Mei , Liu Xiaodong , de Boer Suzan , Knaupp Anja S. , Li Jinhua , Davidson Kathryn C. , Polo Jose M. , Barberi Tiziano
Published: February 2018

The canonical Wnt/β-catenin pathway is crucial for early embryonic patterning, tissue homeostasis, and regeneration. While canonical Wnt/β-catenin stimulation has been used extensively to modulate pluripotency and differentiation of pluripotent stem cells (PSCs), the mechanism of these two seemingly opposing roles has not been fully characterized and is currently largely attributed to activation of nuclear Wnt target genes. Here, we show that low levels of Wnt stimulation via ectopic expression of Wnt1 or administration of glycogen synthase kinase-3 inhibitor CHIR99021 significantly increases PSC differentiation into neurons, cardiomyocytes and early endodermal intermediates. Our data indicate that enhanced differentiation outcomes are not mediated through activation of traditional Wnt target genes but by β-catenin's secondary role as a binding partner of membrane bound cadherins ultimately leading to the activation of developmental genes. In summary, fine-tuning of Wnt signaling to subthreshold levels for detectable nuclear β-catenin function appears to act as a switch to enhance differentiation of PSCs into multiple lineages. Our observations highlight a mechanism by which Wnt/β-catenin signaling can achieve dosage dependent dual roles in regulating self-renewal and differentiation.
Political risk assessment by multinational corporations in African markets: A Nigerian perspective
Authors: Mshelia James B. , Anchor John R.
Published: February 2018

Political risk assessment (PRA) is one of the determinants of foreign direct investment (FDI) and the competitiveness of multinational corporations (MNCs), yet little is known about its use in African markets. This study critically investigates the PRA techniques used by MNCs in Nigeria and their applicability. It uses a multimethod approach to analyze data collected from MNCs and the data set of the International Country Risk Guide (ICRG) PRA annual rating for Nigeria from 2011 to 2015. The findings reveal that most firms use qualitative, rather than quantitative, PRA techniques. Regional variations in the outcome of PRA within Nigeria could also contribute to the low use of quantitative techniques. This article identifies that firms are prepared to invest in Nigeria, in spite of high political risk, due to its economic and financial attractiveness. This article's findings offer some implications for practice with some suggestions on how it could influence firms’ internationalization and their conduct of PRA.
Acute Limb Ischemia Secondary to Native Artery Occlusion: Results of a Contemporary Case Series
Authors: Seguí Nuria , Ruiz‐Carmona Carlos , Velescu Alina , Mateos Eduardo , Elosua Roberto , Clará Albert
Published: February 2018

Background

The treatment of acute limb ischemia (ALI) has barely changed over the last years. However, the progressive implementation of anticoagulants, antiplatelet agents or statins within the population might have modified the profile and prognosis of patients suffering an ALI. The aim of this study was to evaluate the current results of the management of ALI secondary to a native artery occlusion.

Methods

Retrospective study of 220 consecutive patients (mean age 78 years; 49% male) was conducted between 2007 and 2015. ALI secondary to trauma or grafts/stents occlusions were excluded. Statistical analysis was performed with logistic regression.

Results

A total of 141 cases (64.1%) were attributed to embolism and 79 (35.9%) to acute arterial thrombosis. Peripheral neuro‐ischemic impairment occurred in 135 patients (61.4%), being severe in 42 (19.1%). ALI treatment included anticoagulation (n = 27; 12.3%), regional fibrinolysis (n = 2; 1%), embolectomy/thrombectomy (n = 129; 58.6%), angioplasty/stenting (n = 8; 3.6%), bypass (n = 47; 21.3%) or direct major limb amputation (n = 7; 3.2%). Limb salvage and survival rates at 30/90 days were 95%/95% and 82.3%/74.1%, respectively. Independent risk factors for major amputation were diabetes, severe neuro‐ischemic impairment, acute arterial thrombosis and treatment delay >1 day after vascular consultation. In addition, age, chronic peripheral arterial disease, any neuro‐ischemic impairment and a hospitalization for any other reason simultaneous to the ALI were independently associated with mortality.

Conclusions

Regardless of excellent limb salvage rates, patients currently suffering from an ALI are, when compared to previous studies, older than before and with an increased rate of mortality. Risk factors do not appear to be modifiable once the ALI appears so prevention strategies should be aimed to avoid the episode.
Data Improvement Through Simplification: Implications for Low‐Resource Settings
Authors: Anderson Geoffrey A. , Bohnen Jordan , Spence Richard , Ilcisin Lenka , Ladha Karim , Chang David
Published: February 2018

Background

The focus of many data collection efforts centers on creation of more granular data. The assumption is that more complex data are better able to predict outcomes. We hypothesized that data are often needlessly complex. We sought to demonstrate this concept by examination of the American Society of Anesthesiologists (ASA) scoring system.

Methods

First, we created every possible consecutive two, three and four category combinations of the current five category ASA score. This resulted in 14 combinations of simplified ASA. We compared the predictive ability of these simplified scores for postoperative outcomes for 2.3 million patients in the NSQIP database. Individual model performance was assessed by comparing receiver operator characteristic (ROC) curves for each model with the standard ASA.

Results

Two of our 4‐category models and one of our 3‐category models had ability to predict all outcomes equivalent to standard ASA. These results held for all outcomes and on all subgroups tested. The performance of the three best performing simplified ASA scores were also equivalent to the standard ASA score in the univariate analysis and when included in a multivariate model.

Conclusions

It is assumed that the most granular data and use of the largest number of variables for risk‐adjusted predictions will increase accuracy. This complexity is often at the expense of utility. Using the single best predictor in surgical outcomes research, we have shown this is not the case. In this example, we demonstrate that one can simplify ASA into a 3‐category variable without losing any ability to predict outcomes.
Changing the characteristics and properties of zeolite Y and nano-anatase in the formation of a nano-anatase/Y composite with improved photocatalytic and adsorption properties
Authors: Domoroshchina E. N. , Chernyshev V. V. , Kuz’micheva G. M. , Dorokhov A. V. , Pirutko L. V. , Kravchenko G. V. , Chumakov R. B.
Published: February 2018

Zeolite Y and the NTD/Y nanocomposite, which were synthesized in situ (the addition of zeolite Y to the reaction mixture in the course of the synthesis of NTD by the sulfate method), were studied by a variety of methods. The decrease in the particle size (scanning electron microscopy) and the water content in pores (X-ray powder diffraction study, the full-profile Rietveld method, IR spectroscopy, differential scanning calorimetry), the increase in OH groups content and the decrease in the water content on the surface of zeolite (X-ray photoelectron spectroscopy) in the composition of NTD/Y compared to the initial zeolite Y were all established. A larger specific surface area of NTD/Y (Brunauer–Emmet–Teller method) compared to the initial zeolite Y is due to the fact that zeolite Y in the nanocomposite contains a smaller amount of water because of the synthesis conditions and the presence of nanocrystalline NTD on the surface of zeolite particles. It was found that NTD/Y nanocomposite exhibits a higher photocatalytic activity in the model decomposition reaction of methyl orange under UV and adsorption capacity for the extraction of P(V) and As(V) ions from aqueous media compared to the initial zeolite and pure NTD obtained under the same conditions, which differs from NTD/Y by the larger particle size, the smaller specific surface and the smaller content of OH groups and water on the surface. The role of Bronsted and Lewis centers in the realization of properties is discussed.
Electrospinning pectin-based nanofibers: a parametric and cross-linker study
Authors: McCune Devon , Guo Xiaoru , Shi Tong , Stealey Samuel , Antrobus Romare , Kaltchev Matey , Chen Junhong , Kumpaty Subha , Hua Xiaolin , Ren Weiping , Zhang Wujie
Published: February 2018

Pectin, a natural biopolymer mainly derived from citrus fruits and apple peels, shows excellent biodegradable and biocompatible properties. This study investigated the electrospinning of pectin-based nanofibers. The parameters, pectin:PEO (polyethylene oxide) ratio, surfactant concentration, voltage, and flow rate, were studied to optimize the electrospinning process for generating the pectin-based nanofibers. Oligochitosan, as a novel and nonionic cross-liker of pectin, was also researched. Nanofibers were characterized by using AFM, SEM, and FTIR spectroscopy. The results showed that oligochitosan was preferred over Ca2+ because it cross-linked pectin molecules without negatively affecting the nanofiber morphology. Moreover, oligochitosan treatment produced a positive surface charge of nanofibers, determined by zeta potential measurement, which is desired for tissue engineering applications.
Corrosion resistance of BIS 2062-grade steel coated with nano-metal-oxide mixtures of iron, cerium, and titanium in the marine environment
Authors: Ashraf P. Muhamed , Anuradha R.
Published: February 2018

BIS 2062-grade carbon steel is extensively used for fishing boat construction. The steel is highly susceptible to corrosion on the hull and welding joints under marine environment. Here, we demonstrate the application of a novel multifunctional nano-metal-oxide mixture comprised of iron, titanium, and cerium as a marine coating to prevent corrosion. The electrochemical performance of nano-metal-oxide mixture coatings, applied over boat-building steel, was evaluated at 3.5% NaCl medium. The nano-mixture surface coatings showed an efficient corrosion resistance with increased polarization resistance of 6043 Ω cm2 and low corrosion current density of 3.53 × 10−6 A cm−2. The electrochemical impedance spectral data exhibited improvement in the polarization resistance of outermost surface and internal layers. The coating responded faster recovery to normal state when subjected to an induced stress over the coating. The nano-material in the coating behaves as a semiconductor; this enhanced electronic activity over the surface of the steel.
Photocatalytic degradation of organic dyes using composite nanofibers under UV irradiation
Authors: Salama Ahmed , Mohamed Alaa , Aboamera Nada M. , Osman T. A. , Khattab A.
Published: February 2018

In this work, photocatalytic degradation of organic dyes such as methylene blue (MB) and indigo carmine (IC) have been studied by composite nanofibers systems containing cellulose acetate (CA), multiwall carbon nanotubes (CNT) and TiO2 nanoparticles under UV light. The amino factionalized TiO2–NH2 NPs cross-linked to the CA/CNT composite nanofibers works as a semiconductor catalyst. The morphology and crystallinity were characterized by scanning electron microscopy, transmission electron microscopy (TEM), X-ray diffraction, and Fourier transform infrared spectroscopy. It was also seen that many factors affected the photodegradation rate, mainly the pH of the solution and the dye concentration, temperature, etc. The study demonstrated that IC degrades at a higher rate than MB. The maximum photodegradation rate of both organic dyes was achieved at a pH 2. In comparison to other studies, this work achieved high photodegradation rate in lower time and using less power intensity.
Promoting or suppressing resilience to mental health outcomes in at risk young people: The role of parental and peer attachment and school connectedness
Authors: Oldfield Jeremy , Stevenson Andrew , Ortiz Emily , Haley Bethany
Published: February 2018

Adolescent attachment relationships formed with parents are salient predictors of mental health. Few studies, however, have demonstrated whether peer attachment or school connectedness can predict resilience to mental health difficulties when a young person is at risk due to poor parental attachment. Ninety adolescents (44 females and 46 males) living in economically disadvantaged areas and attending informal schooling projects in and around Guatemala City participated. Participants completed self‐report measures of parental and peer attachment, school connectedness and mental health. Resilience to mental health difficulties was predicted by more secure school connectedness but lower levels of secure peer attachment. School connectedness may provide a role in promoting resilience for mental health for adolescents living in risk, whereas the potential negative influence that secure attachments to peers exerts, in context of poor parental attachment, needs to be explored further.
Parental documentation status and academic attitudes and expectations among early adolescent latinos
Authors: Shreffler Karina M. , Giano Zachary , Cox Ronald B. , Merten Michael J. , Gallus Kami L.
Published: February 2018

Many Latino youth are U.S. citizens but live with parents whose immigration status is unauthorized. The association between parental documentation status and early adolescent academic attitudes and expectations is unclear. Using a general population sample of urban 7th grade students who self‐identified as Latino in the South Central U.S. (n = 514), we examine the associations between parental documentation status and youth attitudes about the importance of graduating high school and college and expectations of the likelihood of completing high school and attending college. Findings suggest that parent documentation status is not associated with attitudes toward the importance of high school and college among Latino early adolescents, but it is significantly associated with perceptions of the likelihood of achievement. Thus, parent immigration status may be an educational barrier that needs to be addressed early for Latino youth, as efforts in high school may be too late for some students.
Disability and common mental disorders: Results from the World Mental Health Survey Initiative Portugal
Authors: Antunes Ana , Frasquilho Diana , Azeredo-Lopes Sofia , Neto Daniel , Silva Manuela , Cardoso Graça , Caldas-de-Almeida José Miguel
Published: February 2018

Background

Common mental disorders are highly prevalent and disabling, leading to substantial individual and societal costs. This study aims to characterize the association between disability and common mental disorders in Portugal, using epidemiological data from the World Mental Health Survey Initiative.

Methods

Twelve-month common mental disorders were assessed with the CIDI 3.0. Disability was evaluated with the modified WMHS WHODAS-II. Logistic regression models were used to assess the association between disability and each disorder or diagnostic category (mood or anxiety disorders).

Results

Among people with a common mental disorder, 14.6% reported disability. The specific diagnoses significantly associated with disability were post-traumatic stress disorder (OR: 6.69; 95% CI: 3.20, 14.01), major depressive disorder (OR: 3.49; 95% CI: 2.13, 5.72), bipolar disorder (OR: 3.41; 95% CI: 1.04, 11.12) and generalized anxiety disorder (OR: 3.14; 95% CI: 1.43, 6.90). Both categories of anxiety and mood disorders were significantly associated with disability (OR: 1.88; 95% CI: 1.23, 2.86 and OR: 3.94; 95% CI: 2.45, 6.34 respectively).

Conclusions

The results of this study add to the current knowledge in this area by assessing the disability associated with common mental disorders using a multi-dimensional instrument, which may contribute to mental health policy efforts in the development of interventions to reduce the burden of disability associated with common mental disorders.
The incidence, psychiatric co-morbidity and pharmacological treatment of severe mental disorders in children and adolescents
Authors: Nesvåg Ragnar , Bramness Jørgen G. , Handal Marte , Hartz Ingeborg , Hjellvik Vidar , Skurtveit Svetlana
Published: February 2018

Background

Antipsychotic drug use among children and adolescents is increasing, and there is growing concern about off-label use and adverse effects. The present study aims to investigate the incidence, psychiatric co-morbidity and pharmacological treatment of severe mental disorder in Norwegian children and adolescents.

Methods

We obtained data on mental disorders from the Norwegian Patient Registry on 0–18 year olds who during 2009–2011 were diagnosed for the first time with schizophrenia-like disorder (International Classification of Diseases, 10th revision codes F20-F29), bipolar disorder (F30-F31), or severe depressive episode with psychotic symptoms (F32.3 or F33.3). Data on filled prescriptions for psychotropic drugs were obtained from the Norwegian Prescription Database.

Results

A total of 884 children and adolescents (25.1 per 100 000 person years) were first time diagnosed with schizophrenia-like disorder (12.6 per 100 000 person years), bipolar disorder (9.2 per 100 000 person years), or severe depressive episode with psychotic symptoms (3.3 per 100 000 person years) during 2009–2011. The most common co-morbid mental disorders were depressive (38.1%) and anxiety disorders (31.2%). Antipsychotic drugs were prescribed to 62.4% of the patients, 72.0% of the schizophrenia-like disorder patients, 51.7% of the bipolar disorder patients, and 55.4% of the patients with psychotic depression. The most commonly prescribed drugs were quetiapine (29.5%), aripiprazole (19.6%), olanzapine (17.3%), and risperidone (16.6%).

Conclusions

When a severe mental disorder was diagnosed in children and adolescents, the patient was usually also prescribed antipsychotic medication. Clinicians must be aware of the high prevalence of depressive and anxiety disorders among early psychosis patients.
Efficacy of non-invasive brain stimulation on the symptom dimensions of schizophrenia: A meta-analysis of randomized controlled trials
Authors: Kennedy Nigel I. , Lee Won Hee , Frangou Sophia
Published: February 2018

Background

Transcranial direct current stimulation (tDCS) and repetitive transcranial magnetic stimulation (rTMS) have shown promise in the treatment of schizophrenia.

Objective

To quantify the efficacy of double-blind randomized controlled trials (RCT) of tDCS and rTMS for the positive and negative symptoms of schizophrenia and identify significant moderators relating to patient-related features and stimulation parameters.

Methods

Systemic review and meta-analyses of the relevant literature published until February 1st, 2017 to assess treatment efficacy and quantify the contribution of potential moderator variables.

Results

We identified 7 RCTs on tDCS (involving 105 participants) and 30 RCTs on rTMS (involving 768 participants). Compared to sham, tDCS improved all symptom dimensions but the effect reached significance for negative symptoms (Hedge’s g = −0.63, p = 0.02). Efficacy for positive but not negative symptoms was linearly associated with cumulative tDCS stimulation. Compared to sham, rTMS improved hallucinations (Hedge’s g = −0.51, p < 0.001) and negative symptoms (Hedge’s g = −0.49, p = 0.01) but was associated with modest, non-significant worsening of positive symptoms (Hedge’s g = 0.28, p = 0.13). Higher pulse frequency (>10 Hz), motor threshold intensity of 110%, left prefrontal cortical treatment site and trial duration over 3 weeks were associated with improvement in negative symptoms and worsening in positive symptoms (all p < 0.03).

Conclusions

The symptom dimensions in schizophrenia may respond differently to brain stimulation interventions in a way that may reflect the interaction between disease- and treatment-related mechanisms. Our findings underscore the need for further research into patient selection prior to treatment assignment and greater refinement of stimulation protocols.