bluuebunny/crossref_metadata_2025 huggingface dataset:
Theoretical and Experimental Studies on the Carbon‐Nanotube Surface Oxidation by Nitric Acid: Interplay between Functionalization and Vacancy Enlargement
Authors: Gerber Iann , Oubenali Mustapha , Bacsa Revathi , Durand Jérôme , Gonçalves Alexandra , Pereira M. Fernando R. , Jolibois Franck , Perrin Lionel , Poteau Romuald , Serp Philippe
Published: September 2011

The nitric acid oxidation of multiwalled carbon nanotubes leading to surface carboxylic groups has been investigated both experimentally and theoretically. The experimental results show that such a reaction involves the initial rapid formation of carbonyl groups, which are then transformed into phenol or carboxylic groups. At room temperature, this reaction takes place on the most reactive carbon atoms. At higher temperatures a different mechanism would operate, as evidenced by the difference in activation energies. Experimental data can be partially related to first‐principles calculations, showing a multistep functionalization mechanism. The theoretical aspects of the present article have led us to propose the most efficient pathway leading to carboxylic acid functional groups on the surface. Starting from mono‐vacancies, it ends up with the synergistic formation of dangling ‐COOH groups and the enlargement of the vacancies.
Triflic Acid Catalyzed Reductive Coupling Reactions of Carbonyl Compounds with O‐, S‐, and N‐Nucleophiles
Authors: Gellert Beate A. , Kahlcke Nils , Feurer Markus , Roth Stefanie
Published: September 2011

Highly efficient metal‐free reductive coupling reactions of aldehydes and ketones with a range of nucleophiles in the presence of triflic acid (1–5 mol %) as the catalyst are presented. The reactions can be performed at ambient temperature without exclusion of moisture or air. A range of symmetrical and unsymmetrical ethers were obtained by this method in high yields and short reaction times. For the first time, the influence of additional functionalization has been studied. Furthermore, the formation of thioethers from ketones (by addition of unmodified thiols) and of sulfonamides from either aldehydes or ketones has been achieved under catalytic conditions.
Evaluation of 4,5‐Disubstituted‐2‐Aminoimidazole–Triazole Conjugates for Antibiofilm/Antibiotic Resensitization Activity Against MRSA and Acinetobacter baumannii
Authors: Su Zhaoming , Peng Lingling , Worthington Roberta J. , Melander Christian
Published: September 2011

A library of 4,5‐disubstituted‐2‐aminoimidazole–triazole conjugates (2‐AITs) was synthesized, and the antibiofilm activity was investigated. This class of small molecules was found to inhibit biofilm formation by methicillin‐resistant Staphylococcus aureus (MRSA) at low‐micromolar concentrations; 4,5‐disubstituted‐2‐AITs were also able to inhibit and disperse Acinetobacter baumannii biofilms. The activities of the lead compounds were compared against the naturally occurring biofilm dispersant cis‐2‐decenoic acid and were revealed to be more potent. The ability of selected compounds to resensitize MRSA to traditional antibiotics (resensitization activity) was also determined. Lead compounds were observed to resensitize MRSA to oxacillin by 2–4‐fold.
Prognostic impact of discordant results from cytogenetics and flow cytometry in patients with acute myeloid leukemia undergoing hematopoietic cell transplantation
Authors: Fang Min , Storer Barry , Wood Brent , Gyurkocza Boglarka , Sandmaier Brenda M. , Appelbaum Frederick R.
Published: September 2011

BACKGROUND:

Cytogenetics and multicolor flow cytometry (MFC) are useful tools for monitoring outcome of treatment in acute myeloid leukemia (AML). However, no data are available regarding the meaning of results when the 2 tests do not agree.

METHODS:

The authors of this report analyzed 1464 pairs of concurrent cytogenetics and flow results from 424 patients, before and after hematopoietic cell transplantation, and compared the prognostic impact of discordant and concordant results.

RESULTS:

Informative discordant results were observed in 22% of patients. Compared with patients who had double‐negative test results, either positive result had a significant impact on overall survival and relapse‐free survival. The hazard ratios with either positive cytogenetic results or positive MFC results pretransplantation were 3.1 (P = .009) and 2.5 (P = .0008), respectively, for reduced overall survival and 2.7 (P = .01) and 4.1 (P < .0001), respectively, for decreased recurrence‐free survival. Similar findings were obtained post‐transplantation. Molecular cytogenetics, ie, fluorescence in situ hybridization (FISH), added value to the evaluation of discordant cases.

CONCLUSIONS:

The detection of residual AML by either cytogenetics or flow cytometry in patients who underwent hematopoietic cell transplantation predicted early relapse and shortened survival. Cancer 2012;. © 2011 American Cancer Society.
Progress and Challenges in the Calculation of Electronic Excited States
Authors: González Leticia , Escudero Daniel , Serrano‐Andrés Luis
Published: September 2011

A detailed understanding of the properties of electronic excited states and the reaction mechanisms that molecules undergo after light irradiation is a fundamental ingredient for following light‐driven natural processes and for designing novel photonic materials. The aim of this review is to present an overview of the ab initio quantum chemical and time‐dependent density functional theory methods that can be used to model spectroscopy and photochemistry in molecular systems. The applicability and limitations of the different methods as well as the main frontiers are discussed. To illustrate the progress achieved by excited‐state chemistry in the recent years as well as the main challenges facing computational chemistry, three main applications that reflect the authors’ experience are addressed: the UV/Vis spectroscopy of organic molecules, the assignment of absorption and emission bands of organometallic complexes, and finally, the obtainment of non‐adiabatic photoinduced pathways mediated by conical intersections. In the latter case, special emphasis is put on the photochemistry of DNA. These applications show that the description of electronically excited states is a rewarding but challenging area of research.
3D Amino‐Induced Electroless Plating: A Powerful Toolset for Localized Metallization on Polymer Substrates
Authors: Garcia Alexandre , Berthelot Thomas , Viel Pascal , Jégou Pascale , Palacin Serge
Published: September 2011

The “3D amino‐induced electroless plating” (3D‐AIEP) process is an easy and cost‐effective way to produce metallic patterns onto flexible polymer substrates with a micrometric resolution and based on the direct printing of the mask with a commercial printer. Its effectiveness is based on the covalent grafting onto substrates of a 3D polymer layer which presents the ability to entrap Pd species. Therefore, this activated Pd‐loaded and 3D polymer layer acts both as a seed layer for electroless metal growth and as an interdigital layer for enhanced mechanical properties of the metallic patterns. Consequently, flexible and transparent poly(ethylene terephtalate) (PET) sheets were selectively metalized with nickel or copper patterns. The electrical properties of the obtained metallic patterns were also studied.
Combination of MOFs and Zeolites for Mixed‐Matrix Membranes
Authors: Zornoza Beatriz , Seoane Beatriz , Zamaro Juan M. , Téllez Carlos , Coronas Joaquín
Published: September 2011

Mixed‐matrix membranes (MMMs) were prepared by combinations of two different kinds of porous fillers [metal‐organic frameworks (MOFs) HKUST‐1 and ZIF‐8, and zeolite silicalite‐1] and polysulfone. In the search for filler synergy, the MMMs were applied to the separation of CO2/N2, CO2/CH4, O2/N2, and H2/CH4 mixtures and we found important selectivity improvements with the HKUST‐1‐silicalite‐1 system (CO2/CH4 and CO2/N2 separation factors of 22.4 and 38.0 with CO2 permeabilities of 8.9 and 8.4 Barrer, respectively).
Carbon Dioxide Recycling: Emerging Large‐Scale Technologies with Industrial Potential
Authors: Quadrelli Elsje Alessandra , Centi Gabriele , Duplan Jean‐Luc , Perathoner Siglinda
Published: September 2011

This Review introduces this special issue of ChemSusChem dedicated to CO2 recycling. Its aim is to offer an up‐to‐date overview of CO2 chemical utilization (inorganic mineralization, organic carboxylation, reduction reactions, and biochemical conversion), as a continuation and extension of earlier books and reviews on this topic, but with a specific focus on large‐volume routes and projects/pilot plants that are currently emerging at (pre‐)industrial level. The Review also highlights how some of these routes will offer a valuable opportunity to introduce renewable energy into the existing energy and chemical infrastructure (i.e., “drop‐in” renewable energy) by synthesis of chemicals from CO2 that are easy to transport and store. CO2 conversion therefore has the potential to become a key pillar of the sustainable and resource‐efficient production of chemicals and energy from renewables.
Synthesis and Structural Characterization of Palladacycles with Polydentate Ligands by a Stepwise Coupling Route – Palladacycles Containing Halides as Efficient Catalysts and Substrates
Authors: Xu Chen , Wang Zhi‐Qiang , Zhang Ya‐Peng , Dong Xin‐Ming , Hao Xin‐Qi , Fu Wei‐Jun , Ji Bao‐Ming , Song Mao‐Ping
Published: September 2011

A series of ferrocenyl palladacycles with polydentate ligands were conveniently prepared by the Suzuki coupling reactions of a halide‐containing ferrocenyl palladacycle [PdCl({(η5‐C5H5)}Fe{(η5‐C5H3)N2C4H2Cl})(PPh3)] (1) andarylboronic acids without additional palladium catalysis. In the absence of additional base, amination also occurred in high yield. This new protocol was successfully applied to the Suzuki coupling reactions of the analogous halide‐containing palladacycle [PdCl({(η5‐C5H5)}Fe{(η5‐C5H3)NC5H3Br})(PPh3)] (15) and Buchwald–Hartwig amination of the analogous complex [PdCl({(η5‐C5H5)}Fe{(η5‐C5H3)NC5H3Br})(DCPAB)] (32), where DCPAB = 2‐dicyclohexylphosphanyl‐2′‐(N,N‐dimethylamino)biphenyl. The halide‐containing palladacycles act as efficient catalysts and substrates in the coupling reactions. 37 new examples have been fully characterized by elemental analysis, IR and 1H NMR spectroscopy, and ESI‐MS. Additionally, the molecular structures of eight compounds were determined by single‐crystal X‐ray diffraction, and many types of intermolecular C–H···Cl (O, N, π) interactions and π–π interactions were found in the crystal structures of these palladacycles.
Preparation of Calix[8]arene Derivatives Functionalized at a Single Methylene Bridge
Authors: Itzhak Norbert , Kogan Katerina , Biali Silvio E.
Published: September 2011

A calix[8]arene derivative substituted at the single methylene bridge by a chlorine atom reacts at the substituted bridge with O, N, and C nucleophiles under SN1 conditions. Thiscalix[8]arene can serve as a useful starting material for the preparation of calix[8]arene derivatives functionalized at a single methylene bridge.
Reduced fronto‐callosal fiber integrity in unmedicated OCD patients: A diffusion tractography study
Authors: Oh Jungsu S. , Jang Joon Hwan , Jung Wi Hoon , Kang Do‐Hyung , Choi Jung‐Seok , Choi Chi‐Hoon , Kubicki Marek , Shenton Martha E. , Kwon Jun Soo
Published: September 2011

It is widely accepted that abnormalities in the frontal area of the brain underpin the pathophysiology of obsessive‐compulsive disorder (OCD). Fundamental to this investigation is the delineation of frontal white matter tracts including dorsal and ventral frontal projections of interhemispheric connections. While previous investigations of OCD have examined the dorsal and ventral frontal regions, the corresponding callosal connections have not been investigated, despite their importance. We recruited twenty patients with OCD (15 drug‐naïve and 5 currently unmedicated) and demographically similar healthy controls, and conducted fiber tractography and post hoc quantitative analysis using diffusion tensor imaging. We extracted fractional anisotropy (FA) of the fronto‐callosal fibers along the entire length of the tract. Function‐specific [by the Brodmann area region‐of‐interest (ROI) approach] and region‐specific (by the length‐parameterization approach) tracts were defined. In addition, we devised a new index of dorsal‐ventral imbalance (DVII) of fiber integrity. Significant FA decreases were observed in orbitofrontal and dorsolateral prefrontal projections of the corpus callosum (P < 0.05, false discovery rate‐corrected) with higher function/region sensitivity than voxel‐based or ROI‐based approaches. Importantly, OCD patients also exhibited significantly higher ventral‐greater‐than‐dorsal asymmetry of FA values than normal controls (P < 0.05, FDR‐corrected). This study is the first to investigate fiber integrity in the dorsal/ventral frontal parts of the callosal tractography in unmedicated OCD patients. Using a more quantitative method in terms of functional and regional specificity than previous studies, we report abnormalities in interhemispheric connectivity of both dorsal and ventral networks in the pathophysiology of OCD. Hum Brain Mapp 33:2441–2452, 2012. © 2011 Wiley Periodicals, Inc.
Water storage in a till catchment. I: Distributed modelling and relationship to runoff
Authors: Seibert Jan , Bishop Kevin , Nyberg Lars , Rodhe Allan
Published: September 2011

Although water storage is an important variable to understand the hydrological functioning of a catchment, it is challenging to estimate the total water storage in a catchment. Catchment water storage can be estimated on the basis of water balance, but this approach is prone to errors in the different water balance terms. Here, an approach is presented to estimate the daily dynamics of catchment‐wide soil water and groundwater storage on the basis of groundwater‐level observations, soil properties and an assumption of hydrological equilibrium above the water table. This approach was applied to a 6300‐m2 till catchment in Southwest Sweden. The predicted mean catchment water storage between April 1991 and June 1992 was 210 mm and ranged from 190 to 260 mm. The estimated water storage followed runoff rates closely especially during recession periods. On average, 79% of the water storage was held in the unsaturated zone, and the remaining 21% was groundwater, but this proportion varied strongly with runoff and total storage. During dry conditions, unsaturated storage accounted for at maximum 95% of the water storage; during wet conditions, this number dropped to 40%. Copyright © 2011 John Wiley & Sons, Ltd.
CCN2 promotes cigarette smoke‐induced proliferation of rat pulmonary artery smooth muscle cells through upregulating cyclin D1 expression
Authors: Wang Ran , Xu Yong‐jian , Liu Xian‐sheng , Zeng Da‐xiong , Xiang Min
Published: September 2011

Cigarette smoke has been demonstrated to induce pulmonary vascular remodeling, which is characterized by medial thickening of the pulmonary arteries mainly resulting from the abnormal proliferation of pulmonary artery smooth muscle cells (PASMCs). However, the molecular mechanism underlying this process is still unclear. In the present study, we investigated whether CCN2 regulated rat PASMCs (rPASMCs) proliferation induced by cigarette smoke extract (CSE) and nicotine by upregulating cyclin D1 in vitro. CCN2 siRNA or cyclin D1 siRNA were transfected to rPASMCs which were then exposed to CSE and nicotine. Both mRNA and protein expressions of CCN2 were significantly increased in rPASMCs treated with 2% CSE or 1 µM nicotine, which markedly promoted the proliferation of rPASMCs. CCN2 siRNA inhibited the proliferation of rPASMCs induced by CSE or nicotine. Furthermore, CCN2 siRNA markedly suppressed the mRNA and protein expressions of cyclin D1 in rPASMCs and led to cell cycle arrest in G0/G1 phase resulting in reduced rPASMCs proliferation. These findings suggest that CCN2 contributes to the CSE and nicotine‐induced proliferation of rPASMCs at least in part by upregulating cyclin D1 expression. J. Cell. Biochem. 113: 349–359, 2012. © 2011 Wiley Periodicals, Inc.
Nemo‐like kinase inhibits osteoblastogenesis by suppressing bone morphogenetic protein and WNT canonical signaling
Authors: Zanotti Stefano , Canalis Ernesto
Published: September 2011

The bone morphogenetic protein/Signaling mothers against decapentaplegic (BMP/Smad) and the WNT signaling pathways regulate the commitment of mesenchymal cells to the osteoblastic lineage. Nemo‐like kinase (Nlk) is an evolutionary conserved kinase that suppresses Smad transactivation and WNT canonical signaling. However, it is not clear whether these effects of Nlk have any consequence on the differentiation of mammalian cells. To study the function of Nlk during the commitment of ST‐2 bone marrow stromal cells to the osteoblastic fate, Nlk was downregulated by RNA interference (RNAi), following transfection of a specific small interfering (si)RNA. Nlk downregulation increased alkaline phosphatase and osteocalcin expression and sensitized ST‐2 cells to the effects of BMP2 and WNT3 on alkaline phosphatase mRNA expression and activity. Accordingly, Nlk downregulation enhanced the effect of BMP2 on the transactivation of the BMP/Smad reporter construct 12xSBE‐Oc‐pGL3, and on the levels of phosphorylated Smad1/5/8, whereas it did not affect the transactivation of the transforming growth factor‐β/Smad reporter pSBE‐Luc. Nlk downregulation sensitized ST‐2 cells to the effects of WNT3 on the transactivation of the WNT/T‐cell factor (Tcf) reporter construct 16xTCF‐Luc, whereas it did not affect cytosolic β‐catenin levels. To understand the function of Nlk in cells committed to the osteoblastic lineage, Nlk was suppressed by RNAi in primary calvarial osteoblasts. Downregulation of Nlk increased alkaline phosphatase and osteocalcin transcripts and sensitized osteoblasts to the effects of BMP2 on alkaline phosphatase activity and Smad1/5/8 transactivation and phosphorylation. In conclusion, Nlk suppresses osteoblastogenesis by opposing BMP/Smad and WNT canonical signaling. J. Cell. Biochem. 113: 449–456, 2012. © 2011 Wiley Periodicals, Inc.
Near‐to‐perfect homeostasis: Examples of universal aging rule which germline evades
Authors: Teplyuk Nadiya M.
Published: September 2011

Aging is considered to be a progressive decline in an organism's functioning over time and is almost universal throughout the living world. Currently, many different aging mechanisms have been reported at all levels of biological organization, with a variety of biochemical, metabolic, and genetic pathways involved. Some of these mechanisms are common across species, and others work different, but each of them is constitutive. This review describes the common characteristics of the aging processes, which are consistent changes over time that involve either the accumulation or depletion of particular system components. These accumulations and depletions may result from imperfect homeostasis, which is the incomplete compensation of a particular biological process with another process evolved to compensate it. In accordance with disposable‐soma theory, this imperfection in homeostasis may originate as a function of cell differentiation as early as in yeasts. It may result either from antagonistic pleiotropy mechanisms, or be simply negligible as a subject of natural selection if an adverse effect of the accumulation phenotypically manifests in organism's post‐reproductive age. If this phenomenon holds true for many different functions it would lead to the occurrence of a wide variety of aging mechanisms, some of which are common among species, while others unique, because aging is the inherent property of most biological processes that have not yet evolved to be perfectly in balance. Examples of imperfect homeostasis mechanisms of aging, the ways in which germ line escapes from them, and the possibilities of anti‐aging treatment are discussed in this review. J. Cell. Biochem. 113: 388–396, 2012. © 2011 Wiley Periodicals, Inc.
Confirmatory factor and measurement invariance analyses of the emotion regulation questionnaire
Authors: Melka Stephen E. , Lancaster Steven L. , Bryant Andrew R. , Rodriguez Benjamin F.
Published: September 2011

Emotion regulation is widely studied in many areas of psychology and the number of publications on emotion regulation has increased exponentially over the past few decades. Additionally, interest in the relationships between emotion dysregulation processes and psychopathology has drastically increased in recent years. The Emotion Regulation Questionnaire (ERQ) was developed to measure two specific constructs related to emotion control: reappraisal and suppression (Gross & John, 2003). In its initial validation study and subsequent analyses, the instrument was shown to possess sound psychometric properties, but, to date, inquiry regarding the measure's characteristics has been limited. Factor analytic examinations of commonly used instruments are recommended to validate the properties of a given measure and increase researchers understanding of the measured constructs. The current study examined the psychometric properties of the ERQ in a sample of 1,188 undergraduates through confirmatory factor analysis. Additionally, tests of measurement invariance were employed in order to examine potential structural differences based on gender and ethnicity. The current study supported the original structure of the measure with all demographic groups and exceptional fit was demonstrated. Additional normative data for gender and ethnic groups are included. Results support the use of the instrument in future research. © 2011 Wiley Periodicals, Inc. J Clin Psychol: In Session 67:1–11, 2011.
Telocyte morphologies and potential roles in diseases
Authors: Zheng Yonghua , Bai Chunxue , Wang Xiangdong
Published: September 2011

Telocytes (TCs) are a new type of interstitial cells, a small cellular body with the presence of 2–5 prolongations named as telopode (Tp)‐very thin (less than 0.2 µm) and extremely long (10–1,000 µm), a moniliform aspect, and caveolae, containing a nucleus surrounded by a small amount of cytoplasm. The nucleus occupies about 25% of TC body volume and contains clusters of heterochromatin attached to the nuclear envelope. The perinuclear cytoplasm is rich in mitochondria and contains a small Golgi complex, rough and smooth endoplasmic reticulum and cytoskeletal elements. TCs have several immunophenotypes such as CD34, c‐kit, and vimentin. TCs were found in many organs of mammals with potential biological functions, even though the exact function remains unclear. Recently, we identified and isolated TCs from the trachea for the first time and confirmed the existence of TC in lung tissues, which could have the potential significance in the pathogenesis of pulmonary diseases. Future efforts are required to clarify pathophysiological functions of TCs in the disease. J. Cell. Physiol. 227: 2311–2317, 2012. © 2011 Wiley Periodicals, Inc.
Diffusion‐weighted magnetic resonance imaging in the detection of testicular torsion: Feasibility study
Authors: Maki Daisuke , Watanabe Yuji , Nagayama Masako , Ishimori Takayoshi , Okumura Akira , Amoh Yoshiki , Nakashita Satoru , Terai Akihito , Dodo Yoshihiro
Published: September 2011

Purpose:

To investigate the feasibility and usefulness of diffusion‐weighted magnetic resonance imaging in the detection of testicular torsion.

Materials and Methods:

Institutional Review Board approval and informed consent from all participants were obtained. Consecutive 28 patients with acute scrotal symptoms were included in this study. Fat‐suppressed T2‐weighted, dynamic subtraction contrast‐enhanced, and diffusion‐weighted images were obtained in the coronal plane with a 1.5 T MR unit. An apparent diffusion coefficient (ADC) map was reconstructed from the diffusion‐weighted images obtained with b‐factor of 0 and 800 s/mm2. Comparisons of ADC values between the affected and nonaffected testes were performed with Mann–Whitney's U‐test.

Results:

Diffusion‐weighted and ADC images with diagnostic quality were obtained in 23 out of the 28 patients (82%). In testicular torsion (n = 9), the mean ADC value of the twisted testes was significantly lower than that of the nonaffected testes (0.750 ± 0.297 vs. 1.017 ± 0.165 × 10−3 mm2/sec, P < 0.05). In other scrotal disorders (n = 14), there was no significant difference in the mean ADC value of the testes between the affected and nonaffected side (P = 0.655). The affected‐to‐nonaffected ratio of ADC value was significantly lower in testicular torsion than that in other scrotal disorders (P < 0.05).

Conclusion:

Diffusion‐weighted imaging of the scrotum with testicular ADC measurement can allow for the detection of testicular torsion without any use of contrast media. J. Magn. Reson. Imaging 2011;. © 2011 Wiley Periodicals, Inc.
Association of placental volume measured by MRI and birth weight percentile
Authors: Derwig Iris E. , Akolekar Ranjit , Zelaya Fernando O. , Gowland Penny A. , Barker Gareth J. , Nicolaides Kypros H.
Published: September 2011

Purpose:

To investigate if placental volume in the second trimester of pregnancy is related to uterine artery blood flow and neonatal birth weight.

Materials and Methods:

In 83 singleton pregnancies at 24–29 weeks' gestation, uterine artery pulsatility index (PI) was measured by Doppler ultrasound and placental volume was calculated from images obtained by magnetic resonance imaging (MRI) at 1.5T. The significance of the association between placental volume, uterine artery PI, and birth weight was examined.

Results:

In 37 normal pregnancies resulting in delivery of neonates with birth weight at or above the 10th percentile, the median placental volume increased with gestational age from 363 cm3 at 24 weeks to 515 cm3 at 29 weeks. In 46 pregnancies that resulted in delivery of small for gestational age (SGA) neonates with birth weight below the 10th percentile the median placental volume, corrected for gestational age, was significantly decreased by 120 cm3 (P < 0.0001) and median uterine artery PI was increased (1.87 vs. 1.59, P < 0.0001). There were significant associations between placental volume and both uterine artery PI (r = −0.677, P < 0.0001) and birth weight percentile (r = 0.658, P < 0.0001).

Conclusion:

Placental volume during the second trimester is smaller in pregnancies that subsequently deliver SGA neonates and the measurement is related to placental perfusion. J. Magn. Reson. Imaging 2011;. © 2011 Wiley Periodicals, Inc.
Role of microRNAs in central nervous system development and pathology
Authors: Meza‐Sosa Karla F. , Valle‐García David , Pedraza‐Alva Gustavo , Pérez‐Martínez Leonor
Published: September 2011

Gene expression regulation is essential for correct functioning of the cell. Complex processes such as development, apoptosis, cell differentiation, and cell cycling require a fine tuning of gene expression. MicroRNAs (miRNAs) are small RNAs that have been recognized as key components of the gene expression regulatory machinery. By sequence complementarity, miRNAs recognize target mRNAs and inhibit their function through degradation or by repressing their translation. The development of the central nervous system (CNS) requires precise and exquisitely regulated gene expression patterns. It is now widely recognized that miRNAs have the capacity to provide such fine regulation both in time and in space. High‐throughput analyses as well as classical molecular biology approaches have allowed the identification of essential miRNAs for CNS development and function. Moreover, recent studies in several model organisms are beginning to show intricate regulatory networks involving miRNAs, transcription factors, and epigenetic regulators during CNS development. Here we review recent findings on the role that miRNAs play in the development of the CNS as well as in neuropathologies such as schizophrenia, Parkinson disease, and Alzheimer's disease, among others. © 2011 Wiley Periodicals, Inc.
Effects of extensive circumferential periosteal stripping on the microstructure and mechanical properties of the murine femoral cortex
Authors: Mercurio Andrew D. , Motta Tatiana , Green Eric , Noble Garrett , Hart Richard T. , Allen Matthew J.
Published: September 2011

Extensive periosteal stripping (PS) is a risk factor for post‐radiation pathologic fracture following surgery for extremity soft tissue tumors. The purpose of this study was to determine the effects of PS on bone structure and mechanical properties. Thirty‐one skeletally mature mice underwent PS, with circumferential removal of periosteum from an 8‐mm segment of the mid‐diaphysis of the left femur. Thirty‐one control mice underwent sham surgery in which the femur was isolated without manipulation of the periosteum. At 2, 6, 12, or 26 weeks following surgery, the left femora were examined by micro‐CT to quantify cortical thickness (CtTh), cross‐sectional area (CSA), bone volume (BV), and polar moment of inertia (PMI). Three‐point mechanical bend testing was performed and peak load, stiffness, and energy to failure were determined. PS resulted in significantly decreased CtTh, CSA, BV, and PMI at all time points. Peak load, stiffness, and energy to failure were significantly reduced at 2, 6, and 12 weeks. There were no significant differences in mechanical properties at 26 weeks. In this mouse model, extensive circumferential PS resulted in sustained changes in bone structure that were still evident after 6 months, accompanied by reductions in bone strength that persisted for at least 3 months. © 2011 Orthopaedic Research Society. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 30:561–568, 2012
Review of periprosthetic osteolysis in total joint arthroplasty: An emphasis on host factors and future directions
Authors: Beck Ryan T. , Illingworth Kenneth D. , Saleh Khaled J.
Published: September 2011

Periprosthetic osteolysis is one of the leading causes of total joint revision procedures. If allowed to progress in the absence of radiographic diagnosis and/or proper medical treatment, osteolysis may result in aseptic loosening yielding failure of the implant and the need for complex revision arthroplasty. The purpose of this review was to assess the current understanding of periprosthetic osteolysis with an emphasis on host factors and future directions. A PubMed search was conducted using the following key words; osteolysis, periprosthetic osteolysis, osteolysis imaging. Pertinent articles, as it pertained to the outline of the review, were selected. Periprosthetic osteolysis stems from numerous risk factors. Osteolysis host characteristic risk factors include gender, body weight, and genetics. Current implant designs have reduced the incidence of this disease; however no current design has been able to replicate the in vivo characteristics and therefore development of wear particles continues to be seen. Advanced methods of imaging diagnosis are on the rise, however early imaging diagnosis is currently ineffective. Pharmacologic intervention appears to be a logical avenue for medical intervention, but no approved drug therapy to prevent or inhibit periprosthetic osteolysis is currently available. Although the rate of periprosthetic osteolysis seems to be decreasing with advances in implant design and increased knowledge of the biological process of wear particle induced osteolysis, the rapid increase in the total number of total joint arthroplasties over the next two decades means that better ways of detecting and treating periprosthetic osteolysis are greatly needed. © 2011 Orthopaedic Research Society. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 30:541–546, 2012
Effectiveness of a redesigned vaginal implant transmitter in mule deer
Authors: Bishop Chad J. , Anderson Charles R. , Walsh Daniel P. , Bergman Eric J. , Kuechle Peter , Roth John
Published: September 2011

Our understanding of factors that limit mule deer (Odocoileus hemionus) populations may be improved by evaluating neonatal survival as a function of dam characteristics under free‐ranging conditions, which generally requires that both neonates and dams are radiocollared. The most viable technique facilitating capture of neonates from radiocollared adult females is use of vaginal implant transmitters (VITs). To date, VITs have allowed research opportunities that were not previously possible; however, VITs are often expelled from adult females prepartum, which limits their effectiveness. We redesigned an existing VIT manufactured by Advanced Telemetry Systems (ATS; Isanti, MN) by lengthening and widening wings used to retain the VIT in an adult female. Our objective was to increase VIT retention rates and thereby increase the likelihood of locating birth sites and newborn fawns. We placed the newly designed VITs in 59 adult female mule deer and evaluated the probability of retention to parturition and the probability of detecting newborn fawns. We also developed an equation for determining VIT sample size necessary to achieve a specified sample size of neonates. The probability of a VIT being retained until parturition was 0.766 (SE = 0.0605) and the probability of a VIT being retained to within 3 days of parturition was 0.894 (SE = 0.0441). In a similar study using the original VIT wings (Bishop et al.2007), the probability of a VIT being retained until parturition was 0.447 (SE = 0.0468) and the probability of retention to within 3 days of parturition was 0.623 (SE = 0.0456). Thus, our design modification increased VIT retention to parturition by 0.319 (SE = 0.0765) and VIT retention to within 3 days of parturition by 0.271 (SE = 0.0634). Considering dams that retained VITs to within 3 days of parturition, the probability of detecting at least 1 neonate was 0.952 (SE = 0.0334) and the probability of detecting both fawns from twin litters was 0.588 (SE = 0.0827). We expended approximately 12 person‐hours per detected neonate. As a guide for researchers planning future studies, we found that VIT sample size should approximately equal the targeted neonate sample size. Our study expands opportunities for conducting research that links adult female attributes to productivity and offspring survival in mule deer. © 2011 The Wildlife Society.
LOCAL PERCEPTIONS OF WOODY VEGETATION DYNAMICS IN THE CONTEXT OF A ‘GREENING SAHEL’: A CASE STUDY FROM BURKINA FASO
Authors: Sop T. K. , Oldeland J.
Published: September 2011

After decades of drought in the Sahel, several studies have reported a ‘(re)greening’ of the area. However, most of these studies were based on large scale climatological or remotely sensed observations, with little or no ground truthing. The aim of this study was to assess the local perceptions of the distribution of socio‐economically important tree species in the Sub‐Sahel of Burkina Faso. Semi‐structured interviews were performed with 87 groups of informants from 20 villages belonging to three ethnic groups (Mossi, Fulani and Samo). Univariate and multivariate statistics were used to compare perceptions between the targeted ethnic groups. According to the locals, more than 80 per cent of the 90 listed species were declining, with over 40 per cent identified as threatened, including numerous plants of great economic value. Increasing species were mostly drought‐tolerant plants such as Balanites aegyptiaca. A few species were listed as locally extinct. Gender and age did not significantly affect local knowledge, whereas ethnicity did. The major causes of species decline were identified to be drought, deforestation and bushfires. In all ethnic groups, informants observed a southward shift in species distribution. Local perceptions suggest a general decline in woody vegetation. Thus, the alleged (re)greening in the Sahel might not have reversed the degradation of woody species in the area. Data derived from local ecological knowledge were consistent with that of many ecological studies, suggesting the reliability of people's knowledge for obtaining ecological data. Information from this study can be used as baseline for conservation of species identified as threatened. Copyright © 2011 John Wiley & Sons, Ltd.
Measurements of the persistent singlet state of N2O in blood and other solvents—Potential as a magnetic tracer
Authors: Ghosh R. K. , Kadlecek S. J. , Ardenkjaer‐Larsen J. H. , Pullinger B. M. , Pileio G. , Levitt M. H. , Kuzma N. N. , Rizi R. R.
Published: September 2011

The development of hyperpolarized tracers has been limited by short nuclear polarization lifetimes. The dominant relaxation mechanism for many hyperpolarized agents in solution arises from intramolecular nuclear dipole–dipole coupling modulated by molecular motion. It has been previously demonstrated that nuclear spin relaxation due to this mechanism can be removed by storing the nuclear polarization in long‐lived, singlet‐like states. In the case of N2O, storing the polarization of the nitrogen nuclei has been shown to substantially increase the polarization lifetime. The feasibility of utilizing N2O as a tracer is investigated by measuring the singlet‐state lifetime of the N2O when dissolved in a variety of solvents including whole blood. Comparison of the singlet lifetime to longitudinal relaxation and between protonated and deuterated solvents is consistent with the dominance of spin‐rotation relaxation, except in the case of blood. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
Novel method to measure the shear strength of exfoliated montmorillonite/polymer nanocomposite films
Authors: Lin Keng‐Jen , Hsueh Chun‐Hway , Lin King‐Fu
Published: September 2011

Shear fracture of exfoliated montmorillonite/poly(methyl acrylate‐co‐methyl methacrylate) (MMT/P(MA‐co‐MMA)) nanocomposite films fabricated via soap‐free emulsion polymerization was studied using a unique test fixture that is capable of controlling the inclined angle between the loading axis and the shear fracture plane. It was found that fracture of the films depended on both shear and normal stresses and could be described by the Mohr–Coulomb criterion. The effects of MMT content on the intrinsic shear strength (i.e. the shear strength at zero normal stress) τs were also examined. The obtained τs increased from 1.66 to 2.78 MPa as 1 wt% MMT was incorporated into P(MA‐co‐MMA) and then increased almost linearly to 5.32 MPa when the content of MMT increased to 15 wt%. Also, the fracture‐surface morphology of the composite film depended on both the MMT content and the inclined angle (and hence the normal‐to‐shear stress ratio). For low MMT contents and low normal‐to‐shear stress ratios, striations normal to the shear direction appeared on the fracture surface. As the MMT content or the stress ratio increased, the fracture surface became rough accompanied by the presence of interfacial micro‐cracking between MMT nanoplatelets and the matrix. With further increase in MMT content and high stress ratio, the MMT nanoplatelets were compressed into large flakes on the fracture surface. Copyright © 2011 Society of Chemical Industry
SARS‐CoV heptad repeat 2 is a trimer of parallel helices
Authors: Celigoy Jessica , Ramirez Benjamin , Caffrey Michael
Published: September 2011

In severe acute respiratory syndrome coronavirus, the envelope heptad repeat 2 (HR2) plays a critical role in viral entry. Moreover, HR2 is both the target for novel antiviral therapies and, as an isolated peptide, presents a potential antiviral therapeutic. The structure of HR2, as determined by NMR spectroscopy in the presence of the co‐solvent trifluoroethanol (TFE), is a trimer of parallel helices, whereas the structure of HR2, as determined by X‐ray crystallography, is a tetramer of anti‐parallel helices. In this work, we added a nitroxide spin label to the N‐terminal region of HR2 and used paramagnetic relaxation enhancement to assess the orientation of the HR2 helices under different solution conditions. We find that the relaxation effects are consistent with an orientation corresponding to a trimer of parallel helices in both the presence and absence of TFE. This work suggests that the different orientation and oligomerization states observed by NMR and X‐ray are due to the 11 additional residues present at the N‐terminus of the NMR construct.
Effects of Liquid Contaminants on Heat Seal Strength of low‐density polyethylene Film
Authors: Mihindukulasuriya S. , Lim L.‐T.
Published: September 2011

Heat sealing is commonly applied for making form‐fill‐seal packages fabricated from thermoplastic films. One of the challenges frequently faced by the industry is inadvertent contamination of film–film interface by the product during filling, which can compromise package seal strength. In this study, the effects of dwell time (0.5–1.5 s), jaw pressure (28–1860 kPa), jaw configuration (narrow versus wide contact area) and jaw temperature (150°C–180°C) on the interface temperature and seal strength of a linear low‐density polyethylene (LLDPE) film were investigated. Three different film–film interface conditions were studied: (1) no contaminant; (2) with water contaminant; and (3) with vegetable oil contaminant. In the presence of liquid contaminant, jaw pressure played an important role in displacing the liquid from the seal area to form intact seals. Short dwell time (0.3 s) and low jaw temperature (150°C) was not favourable for forming intact seals in both water‐contaminated and vegetable oil‐contaminated films. The optimum jaw temperature and dwell time required to produce intact seals for oil contaminated films was 180°C and 0.3 s, respectively, whereas a combination of 165°C jaw temperature and 1 s dwell time was required to form intact seals for water‐contaminated films. Within the experimental conditions investigated, interface temperatures of 130°C–140°C resulted in the most optimum seal strength for both water‐contaminated and clean film specimens. Above 140°C, a weakening of seal strength was observed, presumably because of the change in melt flow characteristics and possible initiation of thermal degradation of the polymer. Copyright © 2011 John Wiley & Sons, Ltd.
Microstructual Evolution of a Nb‐Microalloyed Advanced High Strength Steel Treated by Quenching‐Partitioning‐Tempering Process
Authors: Zhong N. , Wang Y. , Zhang K. , Rong Y. H.
Published: September 2011

The recently developed “quenching and partitioning” heat treatment and “quenching‐partitioning‐tempering” heat treatment are novel processing technologies, which are designed for achieving advanced high strength steels (AHSS) with combination of high strength and adequate ductility. Containing adequate amount of austenite phase is an important characteristic of the above steel, and the partitioning treatment is a key step in Q&P or Q‐P‐T process during which the austenite phase is enriched with carbon and achieves thermal stability. However, the microstructural evolution of the steel during the partitioning process is rather complicated. In present study, evolution of complex microstructure in a low carbon steel containing Nb during the Q‐P‐T process has been studied in detail. The microstructural evolution of the steel was investigated in terms of X‐ray diffraction, scanning electron microscope and transmission electron microscope. The experimental results show that the Nb‐microalloyed steel demonstrates a complex multiphase microstructure which consists of lath martensite with high dislocation density, retained austenite, alloy carbide, transition carbide, and a few twin martensite after the Q‐P‐T process. The experimental results can be helpful for the design of Q‐P‐T heat treatment and for the control of mechanical properties of Q‐P‐T steel.
Necrosis and Angioinvasion Predict Adverse Outcome in Pancreatic Neuroendocrine Tumors After Curative Surgical Resection: Results of a Single‐Center Series
Authors: Demir Resit , Pohl Johann , Agaimy Abbas , Peros Georgios , Perrakis Aristoteles , Merkel Susanne , Hohenberger Werner , Klein Peter
Published: September 2011

Background

The prediction of outcome in pancreatic neuroendocrine tumors (P‐NETs) still represents a challenge. Several clinicopathologic parameters have been proposed to predict adverse outcome. The aim of this study was to evaluate the impact of tumor necrosis and angioinvasion on the outcome after curative R0 resection of P‐NETs.

Methods

We reviewed our institutional experience over the last 30 years. A total of 82 patients with a mean age of 54 years (range 17–83 years) underwent surgical resection of P‐NETs during the period from 1964 to 2006. There were 41 men and 41 women. The patients’ outcomes after R0 surgical treatment were analyzed in relation to the presence or absence of tumor cell necrosis and angioinvasion as judged by histologic methods.

Results

The overall (n = 82) 5‐year survival was 52.4% (±6.0%). Forty‐eight of the patients underwent a R0 resection successfully. These patients showed a 5‐year survival of 59.04% (±7.8%); the median survival was 101 ± 36 months. Necrosis status was documented on 47 of the R0 resected patients (97.9%). The survival median of patients with tumor cell necrosis was significantly shorter than those without necrosis (41 ± 25 vs. 173 ± 69 months, respectively, P = 0.006). The patients’ mean 5‐year survival was also significantly decreased (28.9 ± 15.0% vs. 68.5.6 ± 8.9%). Angioinvasion status was documented on 43 of the R0 resected patients (90.0%). The median survival of these patients was decreased from 173 ± 51 to 54 ± 18 months when angioinvasion was observed in the histological sections (P = 0.104). The patients’ mean 5‐year survival was also decreased from 69.2 ± 9.3% to 35.9 ± 14.0%.

Conclusions

Long‐term survival of patients with P‐NETs is influenced by various pathologic factors. Among our patients, there was not a significant difference in overall survival based on the diameter of the primary tumor or the lymph node status after R0 surgical resection. The presence of necrosis in the TNM and World Health Organization classification for pancreatic endocrine tumor was associated with significant poor overall survival in each classification category. Hence, necrosis represents an independent variable for poor prognosis.
Regularity of flat free boundaries in two-phase problems for the p-Laplace operator
Authors: Lewis John L. , Nyström Kaj
Published: September 2011

In this paper we continue the study in Lewis and Nyström (2010) [19], concerning the regularity of the free boundary in a general two-phase free boundary problem for the
p
-Laplace operator, by proving regularity of the free boundary assuming that the free boundary is close to a Lipschitz graph.
How the integration of traditional birth attendants with formal health systems can increase skilled birth attendance
Authors: Byrne Abbey , Morgan Alison
Published: September 2011

Background

Forty years of safe motherhood programming has demonstrated that isolated interventions will not reduce maternal mortality sufficiently to achieve MDG 5. Although skilled birth attendants (SBAs) can intervene to save lives, traditional birth attendants (TBAs) are often preferred by communities. Considering the value of both TBAs and SBAs, it is important to review strategies for maximizing their respective strengths.

Objectives

To describe mechanisms to integrate TBAs with the health system to increase skilled birth attendance and examine the components of successful integration.

Method

A systematic review of interventions linking TBAs and formal health workers, measuring outcomes of skilled birth attendance, referrals, and facility deliveries.

Results

Thirty‐three articles met the selection criteria. Mechanisms used for integration included training and supervision of TBAs, collaboration skills for health workers, inclusion of TBAs at health facilities, communication systems, and clear definition of roles. Impact on skilled birth attendance depended on selection of TBAs, community participation, and addressing barriers to access. Successful approaches were context‐specific.

Conclusions

The integration of TBAs with formal health systems increases skilled birth attendance. The greatest impact is seen when TBA integration is combined with complementary actions to overcome context‐specific barriers to contact among SBAs, TBAs, and women.