bluuebunny/crossref_metadata_2025 huggingface dataset:
Impedance Spectroscopy of Dielectrics and Electronic Conductors
Authors: Bonanos Nikolaos , Pissis Polycarpos , Macdonald J. Ross
Published: June 2012

Impedance spectroscopy is used for the characterization of materials, such as electroceramics, solid and liquid electrochemical cells, dielectrics and also fully integrated devices, such as fuel cells. It consists of measuring the electrical impedance ‐ or a closely related property, such as admittance or dielectric constant ‐ as a function of frequency and comparing the results with expectations based on physical, chemical, and microstructural models. This article reviews the principles and practical aspects of the technique, the representations of the results, the analysis of data, and procedures for the correction of measurement errors. The applications of impedance spectroscopy are illustrated with examples from electroceramics and polymer‐based dielectric systems. The way in which the technique is applied to the two classes of materials is compared with reference to the different models used.
Confocal Fluorescence Microscopy
Authors: Lavrentovich Oleg D.
Published: June 2012

This article describes basic approaches to image materials by means of optical microscopy with fluorescence markers. The fluorescence microscopy is used to image materials in which the contrast cannot be achieved by light absorption, scattering, or birefringence. The fluorescence microscopy benefits greatly from a confocal mode of observation that eliminates signal coming from outside the small region of sample that is probed by a tightly focused laser beam. By scanning the focused laser beamthrough the sample, one obtains a 3D map of density of fluorescing molecules staining the sample. This technique is called confocal laser scanning microscopy (CLSM). By using fluorescent markers of anisometric shape and a polarized laser beam, one can produce 3D images of orientationally ordered materials such as liquid crystals. In this technique, called a fluorescent confocal polarizing microscopy (FCPM), the signal depends on the angle between the transition dipole of the dye and the polarization of probing light. Recent advances in the development of fluorescent markers that can be controllably switched between the bright state and the dark state lead to revolutionary development of far‐field optical microscopy with resolution well below the diffraction limit.
Porosity and Its Measurement
Authors: Espinal Laura
Published: June 2012

Numerous approaches have been applied for measuring the porosity of materials. The most common techniques are based on gas sorption, liquid intrusion, microscopy, and x‐ray and neutron scattering. Each technique provides a characteristic value of porosity, which depends on the measuring principle and nature of the probe. This article describes different porosity measurement methods, which can be selected according to the expected pore‐size range, sample preparation requirements, sample geometry, material properties, and final application.
Smart Polymeric Cathode Material with Intrinsic Overcharge Protection Based on a 2,5‐Di‐tert‐butyl‐ 1,4‐dimethoxybenzene Core Structure
Authors: Weng Wei , Zhang Zhengcheng , Abouimrane Ali , Redfern Paul C. , Curtiss Larry A. , Amine Khalil
Published: June 2012

Polymer‐based electroactive materials have been studied and applied in energy storage systems as a valid replacement for transition metal oxides. As early as 1999, Hass et al. proposed an interesting concept on the possible incorporation of both charge storage and overcharge protection functionality into a single material. However, there are virtually no examples of polymeric materials that can not only store the charge, but also consume the overcharge current. Herein, a new material based on a cross‐linked polymer (I) with 2,5‐di‐tert‐butyl‐1,4‐dimethoxybenzene as the core structure is reported. The cyclic voltammogram of the synthesized polymer shows a single oxidation/reduction peak at 3.9–4.0 V. At 1C rate (56 mA/g), polymer I shows stable cycling up to 200 cycles with <10% capacity loss. The redox shuttle mechanism remarkably can be activated when cell voltage is elevated to 4.3 V and the overcharge plateau at 4.2 V (2nd plateau) is persistent for more than 100 hours. The overcharge protection was due to the release of a chemical redox shuttle species in the electrolyte during the initial charging process. Both DFT calculations and NMR analysis of the aromatic signals in the 1H‐NMR spectrum of electrolytes from “overcharged” cells provide evidence for this hypothesis.
Ethanol‐Dispersed Polymer Nanofibers as a Highly Selective Cell Isolation and Release Platform for CD4+ T Lymphocytes
Authors: Jun Seung‐Hyun , Kim Kwanghee , An Hyo Jin , Kim Byoung Chan , Sonn Chung Hee , Kim Miju , Doh Junsang , Yee Cassian , Lee Kyung‐Mi , Kim Jungbae
Published: June 2012

A novel cell isolation and release platform using electrospun polystyrene‐poly(styrene‐co‐maleic anhydride) (PS‐PSMA) nanofibers is presented. Ethanol treatment of PS‐PSMA nanofibers, employed for the purpose of sterilization, significantly increases their inter‐fiber space for both antibody conjugation and subsequent cell separation. For the selective isolation of CD4+ T cells from heterogeneous mixtures of mouse lymph nodes, capture efficiencies of up to 100% are achieved while maintaining cellular integrity and viability. Once captured, CD4+ T lymphocytes can also be released from the NF scaffolds, further demonstrating its potential functionality as an immune cell‐supporting and releasing matrix. This is the first demonstration of lymphocyte‐culture scaffolds enabling selective isolation, accommodation, and sustained release of CD4+ T cells for the purpose of cell therapies.
“Ship‐in‐a‐Bottle” Growth of Noble Metal Nanostructures
Authors: Xiao Manda , Zhao Chunmei , Chen Huanjun , Yang Baocheng , Wang Jianfang
Published: June 2012

Noble metal nanostructures are grown inside hollow mesoporous silica microspheres using “ship‐in‐a‐bottle” growth. Small Au seeds are first introduced into the interior of the hollow microspheres. Au nanorods with synthetically tunable longitudinal plasmon wavelengths and Au nanospheres are obtained through seed‐mediated growth within the microspheres. The encapsulated Au nanocrystals are further coated with Pd or Pt shells. The microsphere‐encapsulated bimetallic core/shell nanostructures can function as catalysts. They exhibit high catalytic performance and their stability is superior to that of the corresponding unencapsulated core/shell nanostructures in the catalytic oxidation of o‐phenylenediamine with hydrogen peroxide. Therefore, these hollow microsphere‐encapsulated metal nanostructures are promising as recoverable and efficient catalysts for various liquid‐phase catalytic reactions.
Ligand Controlled Highly Selective Copper‐Catalyzed Borylcuprations of Allenes with Bis(pinacolato)diboron
Authors: Yuan Weiming , Ma Shengming
Published: June 2012

Copper‐catalyzed highly selective borylcuprations of allenes with bis(pinacolato)diboron produce two different types of alkenylboranes by applying a ligand effect. In the presence of tris(para‐methoxyphenyl)phosphine [P(C6H4OMe‐p)3], the reaction of aryl‐1,2‐dienes affords 2‐alken‐2‐yl boronates as the only product with exclusive Z‐geometry; the regioselectivity is switched to afford the 1‐alken‐2‐yl boronates as the major products when the bidentate phosphine 2,2′‐bis(diphenylphosphino)biphenyl is used as the ligand.
Dissecting the dissectors: Knowledge, attitude, and practice of body bequests by Nigerian anatomists
Authors: Anyanwu Emeka G. , Obikili Emmanuel N.
Published: June 2012

Anatomy education in most African countries is limited by an insufficient number of cadavers for students to undertake dissection. This already significant shortage is exacerbated by an increasing number of medical schools and students. Virtual dissections are impractical in alleviating such a shortfall in African anatomy education, and further cadaver supply is challenged by unethical and dubious sources. This study was designed to assess the knowledge, attitudes, and practice of whole body and organ donation by Nigerian anatomists with the aim of finding solutions to the problems associated with the availability of cadavers in Nigerian medical schools. Out of 46 anatomists that participated in the survey, only 23.9% would consider donating their whole bodies and 60.9% their organs. More than 95% of respondents did not believe that body bequests could become the sole source of cadavers for anatomic dissection in Nigeria. Age and gender were not statistically significant in the choice of being a body or organ donor. The unacceptability to one's family members regarding body donation was the major reason for respondents' unwillingness to make a whole body donation. None of the 14 medical schools sampled in this study have yet instituted a body registration and donation program. The anatomists showed a high level of knowledge and awareness of body bequest programs, which were not reflected by their attitudes and practice. The authors recommend proactive measures aimed at improving the perception and attitudes of Nigerian anatomists. Anat Sci Educ. © 2012 American Association of Anatomists.
Constructing “sense” from evolving health information: A qualitative investigation of information seeking and sense making across sources
Authors: Genuis Shelagh K.
Published: June 2012

Focusing on information behavior in a context where medical evidence is explicitly evolving (management of the menopause transition), this investigation explored how women interact with and make sense of uncertain health information mediated by formal and informal sources. Based on interviews with 28 information seekers and 12 health professionals (HPs), findings demonstrate that participants accessed and valued a wide range of information sources, moved fluidly between formal and informal sources, and trust was strengthened through interaction and referral between sources. Participants were motivated to seek information to prepare for formal encounters with HPs, evaluate and/or supplement information already gathered, establish that they were “normal,” understand and address the physical embodiment of their experiences, and prepare for future information needs. Findings revealed four strategies used to construct sense from health information mediated by the many information sources encountered and accessed on an everyday basis: women assumed analytic and experiential “postures”; they valued social contexts for learning and knowledge construction; information consistency was used as a heuristic representing accuracy and credibility; and an important feature of sense making was source complementarity. Implications for health information literacy and patient education are discussed.
Stereoselective Glycosylation of Glucosamine: The Role of the N‐Protecting Group
Authors: Enugala Ramu , Carvalho Luísa C. R. , Dias Pires Marina J. , Marques M. Manuel B.
Published: June 2012

Oligosaccharides and glycoconjugates play an important role in biological processes. The use of these complex polymers as biocompatible materials for medicinal applications as well as therapeutic agents for the treatment of several diseases has attracted considerable interest. However, these investigations require large and pure amounts of glycostructures. Glucosamine is one of the major building blocks of these highly important glycoconjugates. Recently, considerable synthetic efforts have been devoted to improving stereoselective glycosylation. In this Focus review, the role of the amine protecting group in the outcome of the glucosamine glycosylation reaction is highlighted.
Sirtuin activators and inhibitors
Authors: Villalba José M. , Alcaín Francisco J.
Published: June 2012

Sirtuins 1‐7 (SIRT1‐7) belong to the third class of deacetylase enzymes, which are dependent on NAD+ for activity. Sirtuins activity is linked to gene repression, metabolic control, apoptosis and cell survival, DNA repair, development, inflammation, neuroprotection, and healthy aging. Because sirtuins modulation could have beneficial effects on human diseases there is a growing interest in the discovery of small molecules modifying their activities. We review here those compounds known to activate or inhibit sirtuins, discussing the data that support the use of sirtuin‐based therapies. Almost all sirtuin activators have been described only for SIRT1. Resveratrol is a natural compound which activates SIRT1, and may help in the treatment or prevention of obesity, and in preventing tumorigenesis and the aging‐related decline in heart function and neuronal loss. Due to its poor bioavailability, reformulated versions of resveratrol with improved bioavailability have been developed (resVida, Longevinex®, SRT501). Molecules that are structurally unrelated to resveratrol (SRT1720, SRT2104, SRT2379, among others) have been also developed to stimulate sirtuin activities more potently than resveratrol. Sirtuin inhibitors with a wide range of core structures have been identified for SIRT1, SIRT2, SIRT3 and SIRT5 (splitomicin, sirtinol, AGK2, cambinol, suramin, tenovin, salermide, among others). SIRT1 inhibition has been proposed in the treatment of cancer, immunodeficiency virus infections, Fragile X mental retardation syndrome and for preventing or treating parasitic diseases, whereas SIRT2 inhibitors might be useful for the treatment of cancer and neurodegenerative diseases.
A QuEChERS‐based extraction method for the residual analysis of pyraclofos and tebufenpyrad in perilla leaves using gas chromatography: application to dissipation pattern
Authors: Al Mahmud M. N. U. , Rahman Musfiqur , Na Tae‐Woong , Park Jong‐Hyouk , Yang Angel , Park Ki Hun , Abd El‐Aty A. M. , Nahar Nilufar , Shim Jae‐Han
Published: June 2012

The objective of this work was to establish a simple extraction method for the residual analysis of pyraclofos and tebufenpyrad in Perilla leaves. A QuEChERS (quick, easy, cheap, effective, rugged and safe) method was used for extraction using ethyl acetate as an extraction solvent, and cleanup was carried out using dispersive solid‐phase extraction technique. The samples were analyzed using gas chromatography with nitrogen phosphorous detector and confirmed by gas chromatography–mass spectrometry. The linearity was excellent (r2 = 1.0) in matrix‐matched calibration for both pesticides. The recoveries at two fortification levels were 80.76–95.38% with relative standard deviation lower than 5%. The limits of detection and limits of quantification were 0.01 and 0.033 mg/kg for both pesticides, respectively. The results revealed that the dissipation pattern of pyraclofos and tebufenpyrad followed first‐order kinetics. The pyraclofos and tebufenpyrad residues declined to a level below the maximum residue limits within 14 day between the last application and harvesting. We suggest that pyraclofos and tebufenpyrad could be used efficiently on perilla leaves under the recommended dosage conditions. Copyright © 2012 John Wiley & Sons, Ltd.
Turbulent flow chromatography in bioanalysis: a review
Authors: Couchman Lewis
Published: June 2012

With advances in fast chromatography techniques, and highly sensitive and selective detection methods such as tandem mass spectrometry, very high‐throughput bioanalytical methods can now be easily developed. The bottleneck of the analytical process then becomes the sample preparation, which it is now realized is crucial to the robust operation of the analytical system, especially for quantitative assays. Turbulent flow liquid chromatography was developed in the late 1990s, and combines ‘size exclusion’ and traditional stationary phase column chemistry to separate macromolecules, such as proteins, from smaller molecules and analytes of interest in biological fluids. By definition, the process is very rapid, and the instrumentation and software have been developed for fully automated, on‐line extraction of neat biological fluids. This work aims to review the chromatographic theory of turbulent flow chromatography and illustrate, using examples from recent literature, the application of this technique to a range of analytes from a number of different biological matrices. Copyright © 2012 John Wiley & Sons, Ltd.
Examining Improvements in Criminogenic Needs: The Risk Reduction Potential of a Structured Re‐entry Program
Authors: Brooks Holliday Stephanie , Heilbrun Kirk , Fretz Ralph
Published: June 2012

The risk–need–responsivity (RNR) model describes the importance of targeting criminogenic needs through planned interventions in order to reduce the risk of future offending behavior. Although risk/needs instruments capture these dynamic risk factors and previous research has demonstrated their sensitivity to change in these domains, correctional programs may not be leveraging the full case management potential of these instruments. This study explored the potential for improvements in criminogenic needs through participation in a brief, structured re‐entry program consistent with the principles of RNR. Four criminogenic needs were identified as having the potential to change during the course of this program: education/employment, family/marital, procriminal attitudes/orientation, and antisocial pattern. The results indicated that overall risk level significantly decreased during the course of the treatment program, as did risk level for each of these criminogenic needs. For three of these domains, the participants in the highest risk category experienced significant improvements, consistent with the risk principle of RNR. Implications for the interface between assessment and treatment planning are discussed. Copyright © 2012 John Wiley & Sons, Ltd.
Kinetics Studies on the Inhibition Mechanism of Pancreatic α‐Amylase by Glycoconjugated 1H‐1,2,3‐Triazoles: A New Class of Inhibitors with Hypoglycemiant Activity
Authors: Senger Mario Roberto , Gomes Lucas da Costa Andrade , Ferreira Sabrina Baptista , Kaiser Carlos Roland , Ferreira Vitor Francisco , Silva Floriano Paes
Published: June 2012

Glycoconjugated 1H‐1,2,3‐triazoles (GCTs) comprise a new class of glycosidase inhibitors that are under investigation as promising therapeutic agents for a variety of diseases, including type 2 diabetes mellitus. However, few kinetics studies have been performed to clarify the mode of inhibition of GCTs with their target glycosidases. Our group has previously shown that some methyl‐β‐D‐ribofuranosyl‐1H‐1,2,3‐triazoles that inhibit baker's yeast maltase were also able to reduce post‐prandial glucose levels in normal rats. We hypothesized that this hypoglycemiant activity was attributable to inhibition of mammalian α‐glucosidases involved in sugar metabolism, such as pancreatic α‐amylase. Hence, the aim of this work was to test a series of 26 GCTs on porcine pancreatic α‐amylase (PPA) and to characterize their inhibition mechanisms. Six GCTs, all ribofuranosyl‐derived GCTs, significantly inhibited PPA, with IC50 values in the middle to high micromolar range. Our results also demonstrated that ribofuranosyl‐derived GCTs are reversible, noncompetitive inhibitors when using 2‐chloro‐4‐nitrophenyl‐α‐D‐maltotrioside as a substrate. E/ES affinity ratios (α) ranged from 0.3 to 1.1, with the majority of ribofuranosyl‐derived GCTs preferentially forming stable ternary ESI complexes. Competition assays with acarbose showed that ribofuranosyl‐derived GCTs bind to PPA in a mutually exclusive fashion. The data presented here show that pancreatic α‐amylase is one of the possible molecular targets in the pharmacological activity of ribofuranosyl‐derived GCTs. Our results also provide important mechanistic insight that can be of major help to develop this new class of synthetic small molecules into more potent compounds with anti‐diabetic activity through rational drug design.
Transventricular balloon dilation and stenting of the RVOT in small infants with tetralogy of fallot with pulmonary atresia
Authors: Cools Bjorn , Boshoff Derize , Heying Ruth , Rega Filip , Meyns Bart , Gewillig Marc
Published: June 2012

Introduction

The management of small infants with tetralogy of Fallot (TOF) with pulmonary atresia (PA) and hypoplastic pulmonary arteries can be very challenging.

Methods

In three small infants (weight range 2,200–3,600 g, pulmonary trunk 2.0–3.2 mm), initial palliation consisted of sternotomy, transventricular puncture of the right ventricular outflow tract and atretic pulmonary valve, followed by balloon dilation (n = 1) or stent deployment (n = 2) from the right ventricle into the pulmonary trunk (stent diameter 5–6 mm, length 16 mm).

Results

The procedure resulted in adequate palliation with good anterograde flow to the pulmonary arteries and near normal saturations in all three patients (>92%); there was no associated morbidity. Additional transvenous stenting was required in all patients because of progressive muscular infundibular stenosis after a median of 3 months. Two patients evolved to full repair at the age of 5 months and one patient with multiple hilar stenoses requires additional percutaneous procedures through the stented RV outflow tract.

Conclusion

Transventricular balloon dilation and stenting of the RVOT through medial sternotomy as initial palliation strategy appears a safe and well tolerated alternative treatment in small infants with TOF with PA and a hypoplastic pulmonary trunk. © 2013 Wiley Periodicals, Inc.
Mechanics of the foot Part 2: A coupled solid–fluid model to investigate blood transport in the pathologic foot
Authors: Mithraratne K. , Ho H. , Hunter P.J. , Fernandez J.W.
Published: June 2012

A coupled computational model of the foot consisting of a three‐dimensional soft tissue continuum and a one‐dimensional (1D) transient blood flow network is presented in this article. The primary aim of the model is to investigate the blood flow in major arteries of the pathologic foot where the soft tissue stiffening occurs. It has been reported in the literature that there could be up to about five‐fold increase in the mechanical stiffness of the plantar soft tissues in pathologic (e.g. diabetic) feet compared with healthy ones. The increased stiffness results in higher tissue hydrostatic pressure within the plantar area of the foot when loaded. The hydrostatic pressure acts on the external surface of blood vessels and tend to reduce the flow cross‐section area and hence the blood supply. The soft tissue continuum model of the foot was modelled as a tricubic Hermite finite element mesh representing all the muscles, skin and fat of the foot and treated as incompressible with transversely isotropic properties. The details of the mechanical model of soft tissue are presented in the companion paper, Part 1. The deformed state of the soft tissue continuum because of the applied ground reaction force at three foot positions (heel‐strike, midstance and toe‐off) was obtained by solving the Cauchy equations based on the theory of finite elasticity using the Galerkin finite element method. The geometry of the main arterial network in the foot was represented using a 1D Hermite cubic finite element mesh. The flow model consists of 1D Navier–Stokes equations and a nonlinear constitutive equation to describe vessel radius–transmural pressure relation. The latter was defined as the difference between the fluid and soft tissue hydrostatic pressure. Transient flow governing equations were numerically solved using the two‐step Lax–Wendroff finite difference method. The geometry of both the soft tissue continuum and arterial network is anatomically‐based and was developed using the data derived from visible human images and magnetic resonance images of a healthy male volunteer. Simulation results reveal that a two‐fold increase in tissue stiffness leads to about 28% reduction in blood flow to the affected region.Copyright © 2012 John Wiley & Sons, Ltd.
Malignant melanoma in neo‐bladder urinary cytology: A brief report
Authors: Sathiyamoorthy Srividya , Ali Syed Z.
Published: June 2012

Malignant melanoma has an unusual predilection for metastasis to the small bowel, sometimes several years after the original diagnosis. In patients who have had a cystoprostatectomy followed by an ileal conduit, metastatic melanoma to the ileal conduit can present in urine cytology. We present a rare case of metastatic malignant melanoma in neo‐bladder urine in a patient who had undergone a cystoprostatectomy for high grade urothelial carcinoma of the bladder and prostatic adenocarcinoma of Gleason grade 3+3 and two excisional procedures for cutaneous malignant melanoma. He presented with persistent hematuria and urinary tract infections unresponsive to treatment. Urine cytology revealed single large atypical cells, with large nuclei, prominent nucleoli, and cytoplasmic melanin pigment. Subsequent surgical resection revealed two areas of metastatic melanoma in the ileum, one of them being in the ileal conduit. The tumor cells were immunoreactive for S‐100 protein, Melan‐A, and HMB‐45 and were negative for CAM5.2 and cytokeratins 7 and 20. Diagn. Diagn. Cytopathol. 2013;41:997–999. © 2012 Wiley Periodicals, Inc.
Endoscopic ultrasound‐guided fine‐needle aspiration diagnosis of merkel cell carcinoma metastatic to the pancreas
Authors: Bernstein Jane , Adeniran Adebowale J. , Cai Guoping , Theoharis Constantine G. A. , Ustun Berrin , Beckman Danita , Aslanian Harry R. , Harigopal Malini
Published: June 2012

Merkel cell carcinoma (MCC) is a rare and highly aggressive primary neuroendocrine carcinoma of the skin with a high propensity for local, regional, and distant spread. Distant metastasis of MCC to the pancreas is uncommonly seen and may impose a diagnostic challenge cytologically. Here we report a case of MCC with pancreatic metastasis, which was diagnosed by endoscopic ultrasound‐guided fine‐needle aspiration (EUS‐FNA). The aspirates revealed both single and clustered epithelial cells with scant cytoplasm and round nuclei with stippled chromatin and inconspicuous nucleoli. Immunocytochemically, the tumor cells were positive for CK20, synaptophysin, CD56, and CD117. The neoplastic cells were also identified by flow cytometry as non‐hematopoietic cells which were positive for CD56 and negative for CD45. To our knowledge, this is only the second case report of MCC metastatic to the pancreas diagnosed by EUS‐FNA. There have been several reports of MCC metastatic to the pancreas diagnosed only at the time of surgical resection. However, a preoperative diagnosis allows for appropriate management while sparing a patient the morbidity of unnecessary procedures. Diagn. Cytopathol. 2014;247–252. © 2012 Wiley Periodicals, Inc.
Singlet Carbenes Derived from Ferrocene and Closely Related Sandwich Complexes
Authors: Siemeling Ulrich
Published: June 2012

This microreview describes the tremendous progress that has been made during the past decade in the area of ferrocene‐based singlet carbenes, the vast majority of which belong to the family of N‐heterocyclic carbenes (NHCs). The ferrocene motif is present in such NHCs either as a ferrocenyl (Fc) substituent or a 1,1′‐ferrocenediyl (fc) backbone. In terms of applications, the modification of popular ferrocene‐based chiral P ligands by following the phosphane‐NHC analogy has been an important guideline for much of the work directed towards catalysis. A particularly exciting development has occurred with NHCs that contain an fc backbone, since these compounds have proved to be capable of small‐molecule activation. The recent development of singlet carbenes that are not based on ferrocene but rather on related ruthenium sandwich complexes demonstrates the wide scope and highly dynamic nature of the field.
Electrophilic Cyclization of 2‐(2′,3′‐Allenyl)acetylacetates with Iodine Using Calcium Hydride as the Base
Authors: Wan Baoqiang , Jiang Xuefeng , Jia Guochen , Ma Shengming
Published: June 2012

A facile and efficient protocol for the synthesis of 4,5‐dihydrofuran derivatives via iodine‐mediated cyclization of various 2‐(2′,3′‐allenyl)acetylacetates with CaH2 as the base has been developed. The yields range from moderate to good. The resulting products can be used for further elaboration by palladium‐catalyzed coupling reactions.
Enantioselective Synthesis of (R)‐Homoboroproline from (S)‐Proline Using a Borylation Approach
Authors: Georgiou Irene , Whiting Andrew
Published: June 2012

(S)‐Proline was converted through a five‐step sequence into (R)‐homoboroproline hydrochloride in 29 % overall yield with 97 % ee The key step was the conversion of N‐Boc iodomethylpyrrolidine into the corresponding pinacol boronate ester by an efficient copper(I)‐catalyzed borylation reaction by using bispinacolatodiboron.
A parallel dual‐electrode detector for capillary electrophoresis
Authors: Dorris Megan K. , Crick Eric W. , Lunte Craig E.
Published: June 2012

An approach to on‐capillary dual‐electrode detection for CE using a parallel electrode configuration has been developed. The parallel configuration provides two operating modes. In the first mode, one working electrode is held at an oxidizing potential and the second working electrode is held at a reducing potential. This results in redox cycling of analytes between the oxidized and reduced forms, enhancing sensitivity compared to single‐electrode detection. In the second mode, both working electrodes are held at different oxidizing potentials. This mode provides electrochemical characterization of electrophoretic peaks. In the redox cyclying mode, signal enhancement of up to twofold was observed for the dual‐electrode detection of phenolic acid standards compared to single‐electrode detection. Variation in response of less than 10% from electrode to electrode was determined (at a concentration of 60 nM) indicating reproducible fabrication. LODs were determined to be as low as 5.0 nM for dual‐electrode configuration. Using the dual‐potential mode peak identification of targeted phenolic acids in whiskey samples were confirmed based on both migration time and current ratios.
Aptamers as affinity ligands for downstream processing
Authors: Walter Johanna‐Gabriela , Stahl Frank , Scheper Thomas
Published: June 2012

Aptamers are single‐stranded synthetic oligonucleotides that are able to capture their target molecule with high affinity and specificity. Therefore, they can be thought of as nucleic acid‐based alternative to antibodies, which have several advantages over their amino acid‐based counterparts. Consequently, aptamers can be used in different applications based on molecular recognition including affinity separations. This review will summarize the state‐of‐the‐art in aptamer‐based affinity separations; will discuss the current limitations and will highlight possible future prospects. The first part will point out the advantages of aptamers in downstream processing. Here, the properties of aptamers will be discussed along with their implications on downstream processing from a user's point of view. In the second part, a brief summary of the literature is given with focus on aptamer‐based separation of proteins. Finally, some drawbacks of aptamers will be illustrated and possibilities to overcome these limitations will be suggested. New technologies in the fields of aptamer selection and synthesis are expected to further promote the use of aptamers as affinity ligands in downstream processing.
Encapsulation of probiotic strains in plain or cysteine‐supplemented alginate improves viability at storage below freezing temperatures
Authors: Sousa Sérgio , Gomes Ana M. , Pintado Maria M. , Malcata Francisco X. , Silva José P. , Sousa José M. , Costa Paulo , Amaral Maria H. , Rodrigues Dina , Rocha‐Santos Teresa A. P. , Freitas Ana C.
Published: June 2012

Four probiotic bacteria (Lactobacillus paracasei L26, L. casei‐01, L. acidophilus Ki, and Bifidobacterium animalis BB‐12®) were encapsulated in plain alginate or alginate supplemented with L‐cysteine·HCl, and resulting microcapsules were stored at different temperatures, namely 21, 4, −20, or −80°C for a period of up to 6 months. The results showed that the encapsulation in calcium alginate microcapsules was only effective in promoting protection at freezing temperatures, independently of the sensitivity of the strain. Storage of calcium alginate microcapsules at −80°C indicated a protective effect upon viability of all four probiotic strains and the presence of L‐cysteine·HCl in the alginate matrix improved protection upon cell viability of B. animalis BB‐12®. An increase in storage temperature of encapsulated bacteria caused an increase in rate of loss in their viability that was strain dependent. This study suggests that microencapsulation of probiotic cells in calcium alginate can be suitable for sustaining the viability of probiotics in food products that require storage below freezing temperatures, even in the absence of cryoprotectors, contributing to an increased shelf life.
Carbon black nanoparticle intratracheal installation results in large and sustained changes in the expression of miR‐135b in mouse lung
Authors: Bourdon Julie A. , Saber Anne T. , Halappanavar Sabina , Jackson Petra A. , Wu Dongmei , Hougaard Karin S. , Jacobsen Nicklas R. , Williams Andrew , Vogel Ulla , Wallin Håkan , Yauk Carole L.
Published: June 2012

MicroRNAs (miRNA) are important noncoding regulatory molecules that bind target messenger RNA (mRNA), primarily affecting their translation into protein. Because miRNAs can simultaneously target hundreds of mRNAs, subtle changes in their expression can elicit important cellular effects. Little is known about the role of miRNAs in pulmonary responses to inhaled particulate matter. We studied pulmonary global miRNA responses to Printex 90 carbon black nanoparticles in (1) nonpregnant C57BL/6 female mice instilled with vehicle or a single dose of 0.162 mg and euthanized 1, 3, and 28 days post‐exposure, and (2) C57BL/6Bom Tac dams instilled with vehicle or a cumulative dose of 0.268 mg (four separate instillations of vehicle or 0.067 mg Printex 90 during pregnancy) and euthanized at weaning (26–27 days postexposure). We measured similar expression profiles in both exposure scenarios, with marked increases in miR‐135b and subtle changes in miR‐21 and miR‐146b. All three miRNAs were confirmed in nonpregnant females by RT‐PCR, whereas only miR‐135b was confirmed in the dams. Target analysis revealed no concomitant changes in established and predicted targets of miR‐135b, miR‐21, or miR‐146b. Analysis of potentially perturbed pathways did not reveal changes that would suggest down‐stream miRNA effects. The reasons for the lack of association between miRNA and transcript profiles may be related to the complexity of miRNA function and fate, or to the possibility that targets may differ from those already established or predicted in silico. We hypothesize that changes in the expression of these miRNAs may be associated with resolution of pulmonary inflammation, but future work will be necessary to precisely identify specific targets of these miRNAs in lungs. Environ. Mol. Mutagen., 2012. © 2012 Wiley Periodicals, Inc.
ACB‐PCR measurement of H‐ras codon 61 CAA→CTA mutation provides an early indication of aristolochic acid I carcinogenic effect in tumor target tissues
Authors: Wang Yiying , Arlt Volker M. , Roufosse Candice A. , McKim Karen L. , Myers Meagan B. , Phillips David H. , Parsons Barbara L.
Published: June 2012

Aristolochic acid (AA) is a strong cytotoxic nephrotoxin and carcinogen, which induces forestomach and kidney tumors in mice and is associated with development of urothelial cancer in humans. This study sought to gain mechanistic insight into AAI‐induced carcinogenesis through analysis of a tumor‐relevant endpoint. Female Hupki mice were treated daily with 5 mg AAI/kg body weight by gavage for 3, 12, or 21 days. Histopathology and DNA adduct analysis confirmed kidney and forestomach as target tissues for AAI‐induced toxicity. H‐ras codon 61 CAA→CTA mutations were measured in mouse kidney and forestomach, as well as liver and glandular stomach (nontarget organs) by allele‐specific competitive blocker‐PCR (ACB‐PCR), because A→T transversion is the predominant mutation induced by AA and this particular mutation was found previously in AA‐induced rodent forestomach tumors. Treatment‐related differences were observed, with the H‐ras mutant fraction (MF) of mouse kidney and forestomach exposed to 5 mg AAI/kg body weight for 21 days significantly higher than that of vehicle‐treated controls (Fisher's exact test, P < 0.05). Statistically significant correlations between dA‐AAI adduct levels (measured previously in the same animals) and induced H‐ras MFs were evident in forestomach of mice treated for 21 days (linear regression, P < 0.05). The significant increase in H‐ras MF in kidney and forestomach, along with the correlation between DNA adducts, histopathology, and oncogene mutation, provide definitive evidence that AA induces tumors through a directly mutagenic mode of action. Thus, measurement of tumor‐associated mutations is a useful tool for elucidating the mechanisms underlying the tissuespecificity of carcinogenesis. Environ. Mol. Mutagen. 2012. © 2012 Wiley Periodicals, Inc.
Ubiquitylation in immune disorders and cancer: from molecular mechanisms to therapeutic implications
Authors: Fulda Simone , Rajalingam Krishnaraj , Dikic Ivan
Published: June 2012

Conjugation of ubiquitin to proteins (ubiquitylation) has emerged to be one of the most crucial post‐translational modifications controlling virtually all cellular processes. What was once regarded as a mere signal for protein degradation has turned out to be a major regulator of molecular signalling networks. Deregulation of ubiquitin signalling is closely associated with various human pathologies. Here, we summarize the current knowledge of ubiquitin signalling in immune deficiencies and cancer as well as the available therapeutic strategies targeting the ubiquitin system in combating these pathogenic conditions.
Loss of stromal androgen receptor leads to suppressed prostate tumourigenesis via modulation of pro‐inflammatory cytokines/chemokines
Authors: Lai Kuo‐Pao , Yamashita Shinichi , Huang Chiung‐Kuei , Yeh Shuyuan , Chang Chawnshang
Published: June 2012

Stromal–epithelial interaction is crucial to mediate normal prostate and prostate cancer (PCa) development. The indispensable roles of mesenchymal/stromal androgen receptor (AR) for the prostate organogenesis have been demonstrated by using tissue recombination from wild‐type and testicular feminized mice. However, the stromal AR functions in the tumour microenvironment and the underlying mechanisms governing the interactions between the epithelium and stroma are not completely understood. Here, we have established the first animal model with AR deletion in stromal fibromuscular cells (dARKO, AR knockout in fibroblasts and smooth muscle cells) in the Pten+/− mouse model that can spontaneously develop prostatic intraepithelial neoplasia (PIN). We found that loss of stromal fibromuscular AR led to suppression of PIN lesion development with alleviation of epithelium proliferation and tumour‐promoting microenvironments, including extracellular matrix (ECM) remodelling, immune cell infiltration and neovasculature formation due, in part, to the modulation of pro‐inflammatory cytokines/chemokines. Finally, targeting stromal fibromuscular AR with the AR degradation enhancer, ASC‐J9®, resulted in the reduction of PIN development/progression, which might provide a new approach to suppress PIN development.
Arctic rockwall retreat rates estimated using laboratory‐calibrated ERT measurements of talus cones in Longyeardalen, Svalbard
Authors: Siewert Matthias Benjamin , Krautblatter Michael , Christiansen Hanne Hvidtfeldt , Eckerstorfer Markus
Published: June 2012

Holocene rockwall retreat rates quantify integral values of rock slope erosion and talus cone evolution. Here we investigate Holocene rockwall retreat of exposed arctic sandstone cliffs in Longyeardalen, central Svalbard and apply laboratory‐calibrated electrical resistivity tomography (ERT) to determine talus sediment thickness. Temperature–resistivity functions of two sandstone samples are measured in the laboratory and compared with borehole temperatures from the talus slope. The resistivity of the higher and lower‐porosity sandstone at relevant borehole permafrost temperatures defines a threshold range that accounts for the lithological variability of the dominant bedrock and debris material. This helps to estimate the depth of the transition from higher resistivities of ice‐rich debris to lower resistivities of frozen bedrock in the six ERT transects. The depth of the debris–bedrock transition in ERT profiles is confirmed by a pronounced apparent resistivity gradient in the raw data plotted versus depth of investigation. High‐resolution LiDAR‐scanning and ERT subsurface information were collated in a GIS to interpolate the bedrock surface and to calculate the sediment volume of the talus cones. The resulting volumes were referenced to source areas to calculate rockwall retreat rates. The rock mass strength was estimated for the source areas. The integral rockwall retreat rates range from 0.33 to 1.96 mm yr–1, and are among the highest rockwall retreat rates measured in arctic environments, presumably modulated by harsh environmental forcing on a porous sandstone rock cliff with a comparatively low rock mass strength. Here, we show the potential of laboratory‐calibrated ERT to provide accurate estimates of rockwall retreat rates even in ice‐rich permafrost talus slopes. Copyright © 2012 John Wiley & Sons, Ltd.
In vitro apoptotic effects of methanol extracts of Dianthus chinensis and Acalypha australis L. targeting specificity protein 1 in human oral cancer cells
Authors: Shin Ji‐Ae , Kim Jae‐Jin , Choi Eun‐Sun , Shim Jung‐Hyun , Ryu Mi Heon , Kwon Ki Han , Park Hee‐Min , Seo Jin‐Young , Lee Soo‐Yeon , Lim Do‐Won , Cho Nam‐Pyo , Cho Sung‐Dae
Published: June 2012

Background

The aims of this study were to evaluate the apoptotic activities and molecular mechanisms of methanol extracts of Dianthus chinensis (MEDC) and Acalypha australis L. (MEAL) in human oral cancer cells.

Methods

The apoptotic effects and related molecular mechanisms of MEDC and MEAL on oral cancer cells were evaluated using MTS assay, DAPI staining, immunostaining, Western blotting, and reverse transcriptase–polymerase chain reaction.

Results

Sp1 was overexpressed in oral tumor tissues compared with normal oral mucosa. Downregulation of Sp1 inhibited the growth of SCC‐15 and YD‐15 oral cancer cells. MEDC and MEAL inhibited cell growth and induced apoptosis in both cell lines by decreasing the expression of Sp1. In addition, treatment of cells with MEDC and MEAL decreased Mcl‐1 expression, which is a downstream target of Sp1.

Conclusion

Our results indicate that MEDC and MEAL are bioactive natural products that can potentially induce apoptosis of tumor cells that overexpress the Sp1 protein. © 2012 Wiley Periodicals, Inc. Head Neck, 2013
The Role of Personal Loss in the Caregiving Experiences of Well Siblings of Adults With Serious Mental Illness
Authors: Leith Jaclyn E. , Stein Catherine H.
Published: June 2012

Objective

The present study examined the role of personal loss due to mental illness and meaning‐related coping strategies on reports of caregiving among well siblings of adults with serious mental illness.

Method

A sample of 103 well siblings of adults with serious mental illness completed an online survey. Participants were recruited through websites related to mental illness and through contact with leaders of family support groups.

Results

Personal loss, not meaning‐related coping, was the strongest predictor of current caregiving among well siblings. Well siblings’ age, support group affiliation, and perceived level of sibling dependence also contributed to variation in reports of current caregiving.

Conclusion

Personal loss has powerful implications for research and interventions focused on sibling involvement in caregiving for adults with mental illness.
An Open Trial of Motivational Interviewing to Address Suicidal Ideation With Hospitalized Veterans
Authors: Britton Peter C. , Conner Kenneth R. , Maisto Stephen A.
Published: June 2012

Objective:

The purpose of this open trial was to test the acceptability of motivational interviewing to address suicidal ideation (MI‐SI) for psychiatrically hospitalized veterans with suicidal ideation, estimate its pre‐post effect size on the severity of suicidal ideation, and examine the rate of treatment engagement after discharge.

Methods:

Participants received a screening assessment, baseline assessment, one or two MI‐SI sessions, posttreatment assessment, and 60‐day follow‐up assessment. Thirteen veterans were enrolled, 9 (70%) completed both MI‐SI sessions and the posttreatment assessment, and 11 (85%) completed the follow‐up assessment.

Results:

Participants found MI‐SI to be acceptable. They experienced large reductions in the severity of suicidal ideation at posttreatment and follow‐up. In the 2 months following discharge, 73% of participants completed two or more mental health or substance abuse treatment sessions each month.

Conclusions:

These preliminary findings suggest that MI‐SI has potential to reduce risk for suicide in psychiatrically hospitalized veterans and that a more rigorous trial is needed. © 2012Wiley Periodicals, Inc. J. Clin. Psychol. 00:1‐11, 2012.
Unraveling the Influences of Soft‐Tissue Flipper Development on Skeletal Variation Using an Extinct Taxon
Authors: Maxwell Erin E.
Published: June 2012

Adaptation to an aquatic habitat results in dramatic changes in tetrapod limb morphology as limbs take on the roles of propulsion and steering and lose their weight‐bearing function. Changes include enclosure of the limb in a soft‐tissue flipper and proportional lengthening of the distal limb, often accomplished through the addition of skeletal elements (hyperphalangy). The flipper structure itself and changes to the developmental architecture permitting hyperphalangy are hypothesized to increase observed limb variation, based on a cetacean model. These hypotheses are examined in the ichthyosaurs Stenopterygius and Mixosaurus. Hyperphalangy combined with high levels of variation in phalangeal counts were observed in both genera. The amount of variation was not proportional to the number of phalanges in a digit, but was related to functional digit length. In addition, qualitative variants were catalogued in both genera. Polyphalangy, phalangeal fusion, and additional ossifications in the zeugopodial row were not observed in Mixosaurus, but were common in Stenopterygius, even though both genera exhibited a similar degree of hyperphalangy. These results suggest that while the flipper structure and processes resulting in hyperphalangy may increase observed variation in phalangeal counts, these factors are unlikely to be causing high levels of qualitative variation in ichthyosaurs. Patterns of variation in ichthyosaur limbs, and thus variability, are unique to species but can change over evolutionary time. J. Exp. Zool. (Mol. Dev. Evol.) 318B:545–554, 2012. © 2012 Wiley Periodicals, Inc.
What happens when you trust your supervisor? Mediators of individual performance in trust relationships
Authors: Li Alex Ning , Tan Hwee Hoon
Published: June 2012

To understand how trust in supervisor translates into individual job performance, we hypothesize that trust in supervisor facilitates positive psychological conditions of meaningfulness, safety, and availability, which in turn predict individual job performance. We assert that each of the three mediating paths in our model represents a distinct mechanism by which trust in supervisor contributes to individual job performance. We test our hypotheses with 206 supervisor–subordinate dyads and find that trust in supervisor contributes to job performance through psychological availability and psychological safety but not psychological meaningfulness. By examining three different psychological mechanisms within the same frame, we provide a test that compares and contrasts the uniqueness of the three pathways. Our findings suggest practical ways for managers to build trust with subordinates and guidance for the design of productive work conditions. Copyright © 2012 John Wiley & Sons, Ltd.