bluuebunny/crossref_metadata_2025 huggingface dataset:
Lithium Choreography: Intramolecular Arylations of Carbamate‐Stabilised Carbanions and Their Mechanisms Probed by In Situ IR Spectroscopy and DFT Calculations
Authors: Fournier Anne M. , Nichols Christopher J. , Vincent Mark A. , Hillier Ian H. , Clayden Jonathan
Published: October 2012

Deprotonation of O‐allyl, O‐propargyl or O‐benzyl carbamates in the presence of a lithium counterion leads to carbamate‐stabilised organolithium compounds that may be quenched with electrophiles. We now report that when the allylic, propargylic or benzylic carbamate bears an N‐aryl substituent, an aryl migration takes place, leading to stereochemical inversion and C‐arylation of the carbamate α to oxygen. The aryl migration is an intramolecular SNAr reaction, despite the lack of anion‐stabilising aryl substituents. Our in situ IR studies reveal a number of intermediates along the rearrangement pathway, including a “pre‐lithiation complex,” the deprotonated carbamate, the rearranged anion, and the final arylated carbamate. No evidence was obtained for a dearomatised intermediate during the aryl migration. DFT calculations predict that during the reaction the solvated Li cation moves from the carbanion centre, thus freeing its lone pair for nucleophilic attack on the remote phenyl ring. This charge separation leads to several alternative conformations. The one having Li+ bound to the carbamate oxygen gives rise to the lowest‐energy transition structure, and also leads to inversion of the configuration. In agreement with the IR studies, the DFT calculations fail to locate a dearomatised intermediate.
Supramolecular Polymer Hydrogels from Bolaamphiphilic L‐Histidine and Benzene Dicarboxylic Acids: Thixotropy and Significant Enhancement of EuIII Fluorescence
Authors: Liu Yaqing , Wang Tianyu , Liu Minghua
Published: October 2012

Supramolecular polymers from the bolaamphiphilic L‐histidine (BolaHis) and benzene dicarboxylic acids (o‐phthalic acid, OPA; isophthalic acid, IPA and terephthalic acid, TPA) were found to form hydrogels although neither of the single components could gel water. It was suggested that the hydrogen bond and ionic interactions among different imidazole and carboxylic acid groups are responsible for the formation of the supramolecular polymer as well as the hydrogel formation. Depending on the structures of the dicarboxylic acids, different behaviors of the gels were observed. The hydrogels from OPA/BolaHis and IPA/BolaHis showed thixotropic properties, that is, the hydrogel was destroyed by hand shaking and then slowly gelated again at room temperature. However, the hydrogels of TPA/BolaHis could not. Interestingly, when EuIII was doped into IPA/BolaHis supramolecular polymers, very strong luminescence enhancement was observed. FT‐IR spectroscopies and XRD analysis revealed that the strong luminescence enhancement could be attributed to the matched supramolecular nanostructures, which render the correct binding and a good dispersion of EuIII ions. The work offers a new approach for fabricating functional hydrogels through the supramolecular polymers.
Density Functional Theory Investigation on the Second‐Order Nonlinear Optical Properties of Chlorobenzyl‐o‐Carborane Derivatives
Authors: Liu Yan , Yang Guochun , Sun Shiling , Su Zhongmin
Published: October 2012

The structures and second‐order nonlinear optical (NLO) properties of a series of chlorobenzyl‐o‐carboranes derivatives (1–12) containing different push‐pull groups have been studied by density functional theory (DFT) calculation. Our theoretical calculations show that the static first hyperpolarizability (βtot) values gradually increase with increasing the π‐conjugation length and the strength of electron donor group. Especially, compound 12 exhibits the largest βtot (62.404×10−30 esu) by introducing tetrathiafulvalene (TTF), which is about 76 times larger than that of compound 1 containing aryl. This means that the appropriate structural modification can substantially increase the first hyperpolarizabilities of the studied compounds. For the sake of understanding the origin of these large NLO responses, the frontier molecular orbitals (FMOs), electron density difference maps (EDDMs), orbital energy and electronic transition energy of the studied compounds are analyzed. According to the two‐state model, the lower transition energy plays an important role in increasing the first hyperpolarizability values. This study may evoke possible ways to design preferable NLO materials.
A Convenient Hydrogenation Method for the Synthesis of Metallo‐mesoporphyrin IX Dimethyl Esters via Self‐catalyzed CoCl2‐NaBH4 Reagent System
Authors: Xu Shichao , Hu Bingcheng , Hu Tianjing , Wang Huan , Huang Xiuyou , Lou Xingkun , Liu Zuliang
Published: October 2012

A convenient protocol has been developed for the hydrogenation of metallo‐protoporphyrin IX dimethyl esters (MPPDMEs) to their mesoporphyrin analogues using CoCl2‐NaBH4 reagent system. Metallo‐porphyrin complexes were found to perform as self‐catalysts in this procedure. This method provides several advantages such as safe and simple procedure, short reaction time, high yields and low cost.
Synthesis of 2(5H)‐Furanone Derivatives with Bis‐1,2,3‐triazole Structure
Authors: Huo Jingpei , LÜ Meixiang , Wang Zhaoyang , Li Yizhong
Published: October 2012

A series of new chiral 2(5H)‐furanone derivatives containing bis‐1,2,3‐triazole moiety were designed and synthesized from (5S)‐5‐alkoxy‐3,4‐dihalo‐2(5H)‐furanones 1, dicarboxyl amino acids 2, propargyl bromide, and organic azides 5 under mild conditions via the sequential three steps, including asymmetric Michael addition‐elimination, substitution and no‐ligand click reaction. Twelve new intermediates, including N‐[5‐alkoxy‐2(5H)‐furanonyl] dicarboxyl amino acids 3 and their corresponding propargyl esters 4, and twelve target molecules 6 were characterized by FTIR, 1H NMR, 13C NMR, MS and elemental analysis. The influences of different synthetic conditions and substrates in each step were investigated. The research provides a new method and idea for the synthesis of 2(5H)‐furanone compounds with polyheterocyclic structure due to the diversities of four basic unit molecules.
Theoretical Investigation on the Electron and Energy Transfer between Peripheral Carrier Transport Groups and Central Chromophores in Electroluminescent Materials
Authors: Pan Yuyu , Liu Dandan , Xu Hai , Liu Xiaodong , Sun Guannan , Yang Bing , Ma Yuguang
Published: October 2012

The molecular materials with structures of luminescent core and peripheral carrier groups (e.g. carbazoles), have exhibited high‐performance in organic light‐emitting diodes (OLEDs). Present work is to understand the basic process of electronic and energy exchange between the peripheral functional groups and the central core through quantum chemical analysis. As an example, 4,7‐bis(9,9‐bis(6‐(9H‐carbazol‐9‐yl)hexyl)‐9H‐fluoren‐2‐yl)benzo[c]‐[1,2,5]thiadiazole (TCBzC) is investigated in regards to optoelectronic properties using density functional theory (DFT). The results suggest that the forbidden transition from peripheral carbazole to the central chromophore core makes for separated electrical and optical properties, and high performance electroluminescence (EL) is mainly attributed to the energy‐transfer from carbazoles to the fluorene derivative core
Density Functional Theoretical Analysis of the Molecular Structural Effects on Raman Spectra of β‐Carotene and Lycopene
Authors: Liu Weilong , Wang Zhigang , Zheng Zhiren , Jiang Lilin , Yang Yanqiang , Zhao Liancheng , Su Wenhui
Published: October 2012

The molecular structural and Raman spectroscopic characteristics of β‐carotene and lycopene are investigated by density functional calculations. The effects of molecular structure and solvent environment on the Raman spectra are analyzed by comparing the calculated and measured results. It is found that the B3LYP/6‐31G(d) method can predict the reasonable result for β‐carotene, but the ν1 Raman activities of lycopene overflow at all the used theoretical methods because of the longer conjugation length. The calculated results indicate that the rotation of β‐rings in β‐carotene impedes the delocalization of π‐electrons, shortens the effective conjugation length, and results in higher frequency and lower activity of the ν1 mode in β‐carotene than lycopene. The measured ν1 bands of β‐carotene and lycopene shift respectively to higher and lower frequencies in solution compared with that in crystals since the crystal packing forces can lead to different conformational variations in the carotenoids molecules. The polarized continuum model theoretical analysis suggests that solvent has slight (significant) effects on the Raman frequencies (intensities) of both carotenoids.
Group IV M‐POSS (M=Zr, Hf) Coordination Polymers
Authors: Wei Zhijun , Ren Hongbo , Zhang Lin , Luo Meiming
Published: October 2012

The synthesis and characterization of Zr‐POSS and Hf‐POSS coordination polymers were reported. The IR data and the solid‐state 29Si MAS NMR indicated the existence of SiOM linkage. The polarized optical microscopy images and the XRD data suggested their crystalline nature.
A General and Efficient CuBr2‐Catalyzed N‐Arylation of Secondary Acyclic Amides
Authors: Wang Mangang , Yu Hua , You Xinwen , Wu Jun , Shang Zhicai
Published: October 2012

A general and efficient Cu(II)‐catalyzed cross‐coupling method is reported for the preparation of acyclic tertiary amides. Generally moderate to excellent yields and functional group tolerance were obtained with secondary acyclic amides and aryl halides as substrates in toluene.
Tetrahydropyranylation of Alcohols and Phenols Using Polystyrene Supported Lewis Acids as Catalysts
Authors: Zhang Yi , Dou Qianqian , Liu Yuan , Dai Liyan , Wang Xiaozhong , Chen Yingqi
Published: October 2012

Polystyrene supported TiCl4 (Ps‐TiCl4) and polystyrene supported FeCl3 (Ps‐FeCl3) were prepared by coordinating Lewis acids with polystyrene. The catalysts were characterized by TGA, BET, SEM, IR and pyridine‐adsorbed IR. The loading of Ps‐TiCl4 and Ps‐FeCl3 were 0.35 and 0.3 mmol·g−1 respectively. Both catalysts were found to be efficient for the tetrahydropyranylation and detetrahydropyranylation of various alcohols and phenols in different solvents. Two catalysts can be recovered and reused for five times with good activity.
Molecular Design of D‐π‐A Type II Organic Sensitizers for Dye Sensitized Solar Cells
Authors: Li Shifeng , Yang Xichuan , Qu Dingfeng , Wang Weihan , Wang Yu , Sun Licheng
Published: October 2012

Four new type II organic dyes with D‐π‐A structure (donor‐π‐conjugated‐acceptor) and two typical type II sensitizers based on catechol as reference dyes are synthesized and applied in dye sensitized solar cells (DSCs). The four dyes can be adsorbed on TiO2 through hydroxyl group directly. Electron injection can occur not only through the anchoring group (hydroxyl group) but also through the electron‐withdrawing group (CN) located close to the semiconductor surface. Experimental results show that the type II sensitizers with a D‐π‐A system obviously outperform the typical type II sensitizers providing much higher conversion efficiency due to the strong electronic push‐pull effect. Among these dyes, LS223 gives the best solar energy conversion efficiency of 3.6%, with Jsc=7.3 mA·cm−2, Voc=0.69 V, FF=0.71, the maximum IPCE value reaches 74.9%.
Palladium‐Catalyzed Suzuki‐Miyaura Type Coupling Reaction of Aryl Halides with Triphenylborane‐Pyridine
Authors: Yang Minghua , Gu Yongbing , Wang Yan , Zhao Xiyu , Yan Guobing
Published: October 2012

The Suzuki‐Miyaura type coupling reaction of aryl halides with triphenylborane‐pyridine was described. The reaction can be catalyzed by Pd(OAc)2 (5 mol%) in presence of Cs2CO3 at 50°C or 80°C, and functionalized biaryls were obtained in good to excellent yields. This protocol is general and can tolerate a wide range of functional groups.
Novel Synthetic Route to α‐Aminophosphonates Containing Benzothiazole Moiety
Authors: Gu Liju , Wang Rui , Huang Xiangzhong , Jin Cheng
Published: October 2012

A novel and ef?cient synthetic route to α‐aminophosphonates containing benzothiazole moiety via a cascade three‐component reaction from conveniently available starting materials has been developed. The target compounds 3a–3g, 7 and 8a, 8b were evaluated for their anticancer activities against the cancer cell line HL‐60 in vitro by the MTT method. Compound 3g showed good cancer inhibitory activity against the tested cell line. Further study is necessary to find out the potential antitumor activities.
Design of microstrip‐based surface coils for low‐field small‐bore MR applications
Authors: Seo Youngseob
Published: October 2012

Microstrip transmission line concept, which has been used to construct microwave integrated circuits or high frequency (≥300 MHz) antennas, is introduced to surface receive coils for use in a small volume coil at 1T and the feasibility of the microstrip‐based coils is investigated. Both single‐turn and two‐turn microstrip receive coils are fabricated. The size of the square shaped coil loop is 2.5 × 2.5 cm2. A lengthening inductor (toroid) is used to replace a long coaxial cable (=217 cm) needed for low‐field small‐bore MR applications. The lengthening inductor, matching, and tuning capacitors are located outside the magnet. One pulse and a gradient reversed form of FISP sequences are used to acquire NMR signals and MR images of gel phantoms, respectively. MR images acquired by the two‐turn coil have higher SNR and more uniform signal intensity than those obtained by the single‐turn coil and the volume coil. A novel, easy, and efficient method to design small microstrip‐based RF surface receive coils is developed and tested for low‐field small‐bore MR applications. © 2012 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 41B: 111–119, 2012
A novel method for coil efficiency estimation: Validation with a 13C birdcage
Authors: Giovannetti Giulio , Frijia Francesca , Hartwig Valentina , Menichetti Luca , De Marchi Daniele , Positano Vincenzo , Landini Luigi , Lombardi Massimo , Santarelli Maria Filomena , Ardenkjaer‐Larsen Jan Henrik
Published: October 2012

Coil efficiency, defined as the B1 magnetic field induced at a given point on the square root of supplied power P, is an important parameter that characterizes both the transmit and receive performance of the radiofrequency (RF) coil. Maximizing coil efficiency will maximize also the signal‐to‐noise ratio. In this work, we propose a novel method for RF coil efficiency estimation based on the use of a perturbing loop. The proposed method consists of loading the coil with a known resistor by inductive coupling and measuring the quality factor with and without the load. We tested the method by measuring the efficiency of a 13C birdcage coil tuned at 32.13 MHz and verified its accuracy by comparing the results with the nuclear magnetic resonance nutation experiment. The method allows coil performance characterization in a short time and with great accuracy, and it can be used both on the bench and inside the scanner. © 2012 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 41B: 139–143, 2012
Bortezomib, melphalan, and prednisone in elderly patients with relapsed/refractory multiple myeloma
Authors: Petrucci Maria Teresa , Levi Anna , Bringhen Sara , Scotti Simona , Gentilini Fabiana , Russo Simone , Siniscalchi Agostina , Larocca Alessandra , Grammatico Sara , Boccadoro Mario , Foà Robin , Palumbo Antonio
Published: October 2012

BACKGROUND:

In elderly patients with newly diagnosed multiple myeloma (MM), the addition of bortezomib to standard, combined oral melphalan and prednisone (MP) significantly increases the response rate and event‐free survival compared with MP alone.

METHODS:

In this phase 1/2 trial, the authors assessed the dosing, efficacy, and safety of a lower dose‐intensity MP schedule plus weekly bortezomib as salvage treatment for elderly patients with MM. To assess the maximum tolerated dose, 19 patients who had relapsed/refractory MM after 1 or 2 lines of treatment entered the first phase of the study. They received melphalan at a dose of 24 mg for 28 days; bortezomib 1.3 mg/m2on days 1, 8, 15, and 22; and prednisone at a dose of 50 mg every other day of a 28‐day cycle for a total of 9 cycles. At the end of the first phase, based on the good efficacy and acceptable toxicity of this combination, an additional 23 patients were enrolled.

RESULTS:

After a median follow‐up of 21 months, of 42 patients who relapsed, 24 (57%) obtained at least a partial response, 4 had stable disease, and 11 had progressive disease. The median time to progression was 18 months, and the median overall survival was 30 months. Grade 3 and 4 toxicity was observed in 16 of 42 patients (38%) and was more frequent during the early cycles.

CONCLUSIONS:

A weekly infusion of bortezomib associated with lower dose‐intensity MP induced a high proportion of responses and was well tolerated in elderly patients with relapsed/refractory MM. Cancer 2013. © 2012 American Cancer Society.
Two days of antithymocyte globulin are associated with a reduced incidence of acute and chronic graft‐versus‐host disease in reduced‐intensity conditioning transplantation for hematologic diseases
Authors: Crocchiolo Roberto , Esterni Benjamin , Castagna Luca , Fürst Sabine , El‐Cheikh Jean , Devillier Raynier , Granata Angela , Oudin Claire , Calmels Boris , Chabannon Christian , Bouabdallah Réda , Vey Norbert , Blaise Didier
Published: October 2012

BACKGROUND:

The optimal combination of fludarabine, busulfan, and antithymocyte globulin (ATG) for reduced‐intensity conditioning (RIC) transplantation has not been established. ATG plays a pivotal role in the prevention of graft‐versus‐host disease (GvHD), but it is associated with a higher relapse rate and an elevated incidence of infections when high doses are used.

METHODS:

The authors retrospectively compared 2 different doses of ATG combined with fludarabine and busulfan in 229 adult patients who underwent transplantation at their institution. ATG was administered over 1 day (FBA1) or over 2 days (FBA2) at a daily dose of 2.5 mg/kg.

RESULTS:

There were 124 patients in the FBA2 cohort and 105 patients in the FBA2 cohorts. Patients in the FBA2 cohort were older and more frequently underwent transplantation from an unrelated donor; 93% of patients in the FBA2 cohort received intravenous busulfan versus only 5% in the FBA1 cohort. The incidence of grade 2 through 4 acute GvHD was 23% in the FBA2 cohort versus 42% in the FBA1 cohort (P= .002); the incidence of grade 3 through 4 acute GvHD was 10% versus 23%, respectively (P= .006); and the incidence of chronic GvHD was 35% versus 69%, respectively (P< .0001). The 2‐year rates of overall survival, nonrelapse mortality, and relapse/progression for the FBA1 and FBA2 cohorts were 65% versus 67%, respectively (P= .99), 20% versus 19%, respectively (P= .61), and 30% versus 19%, respectively (P= .09). The results were confirmed in multivariate analysis.

CONCLUSIONS:

The use of ATG at a dose of 5 mg/kg was correlated significantly with reduced incidence and severity of GvHD without impairing disease control. Taken together, the current results suggest that this conditioning represents a step forward in the optimization of RIC. Cancer 2013. © 2012 American Cancer Society.
Thyroid transcription factor‐1 expression is an independent predictor of recurrence and correlates with the IASLC/ATS/ERS histologic classification in patients with stage I lung adenocarcinoma
Authors: Kadota Kyuichi , Nitadori Jun‐ichi , Sarkaria Inderpal S. , Sima Camelia S. , Jia Xiaoyu , Yoshizawa Akihiko , Rusch Valerie W. , Travis William D. , Adusumilli Prasad S.
Published: October 2012

BACKGROUND:

In the current study, the authors investigated whether thyroid transcription factor‐1 (TTF‐1) expression is correlated with the International Association for the Study of Lung Cancer (IASLC)/American Thoracic Society (ATS)/European Respiratory Society (ERS) classification and whether it stratifies patients with stage I lung adenocarcinoma with respect to disease recurrence.

METHODS:

Patients with stage I lung adenocarcinoma were classified according to the IASLC/ATS/ERS classification. Tissue microarrays were constructed and immunostaining for TTF‐1 was performed. A total of 452 cases were available for analysis. Tumors were dichotomized based on the intensity of nuclear TTF‐1 expression as negative (score of 0) or positive (score of 1–3). The cumulative incidence of recurrence (CIR) was used to estimate disease recurrence probabilities.

RESULTS:

TTF‐1 expression was identified in 92% of patients, including 100% of patients with minimally invasive or lepidic‐predominant adenocarcinoma, 94% of patients with acinar‐predominant adenocarcinoma, 98% of patients with papillary‐predominant adenocarcinoma, 93% of patients with micropapillary‐predominant adenocarcinoma, 86% of patients with solid‐predominant adenocarcinoma, 67% of patients with colloid‐predominant adenocarcinoma, and 47% of patients with invasive mucinous carcinoma. The CIR for patients with negative TTF‐1 expression (n = 34 patients; 5‐year CIR, 40%) was significantly higher than that for patients with positive TTF‐1 expression (n = 418 patients; 5‐year CIR, 15%) (P < .001). Among the patients with intermediate‐grade tumors, the CIR for patients with negative TTF‐1 expression (n = 16 patients; 5‐year CIR, 45%) was significantly higher than that for patients with positive TTF‐1 expression (n = 313 patients; 5‐year CIR, 14%) (P < .001). On multivariate analysis, negative TTF‐1 expression was found to be significantly correlated with an increased risk of disease recurrence (hazards ratio, 2.55; P = .009).

CONCLUSIONS:

TTF‐1 expression was found to be an independent predictor of disease recurrence, stratifying intermediate‐grade tumors into 2 prognostic subsets, and it correlates with the IASLC/ATS/ERS classification. Cancer 2013. © 2012 American Cancer Society.
Graphics processing unit acceleration of the red/black SOR method
Authors: Konstantinidis Elias , Cotronis Yiannis
Published: October 2012

This work presents our strategy, applied optimizations and results in our effort to exploit the computational capabilities of graphics processing units (GPUs) under the CUDA environment in order to solve the Laplacian PDE. The parallelizable red/black successive over‐relaxation (SOR) method was used. Additionally, a program for the CPU was developed as a performance reference. Various performance improvements were achieved by using optimization methods, which proved to provide significant speedup. Memory access patterns prove to be a critical factor in efficient program execution on GPUs and it is, therefore, appropriate to follow data reorganization to achieve the highest feasible memory throughput. The same approach exhibits performance benefits on the CPU version, as well. Eventually, a direct comparison of optimal versions’ performance was realized. A 10 × speedup was measured for the CUDA version on an NVidia GTX480 GPU (NVidia Corp, Sta. Clara, CA, USA), exceeding 142 GB/s bandwidth, over the single threaded CPU version when run on an Intel Core i7 2600K CPU. The results prove that the global memory cache added on recent GPU architectures assist achieving high performance without requiring to employ the special memory types provided by the GPU (i.e. shared, texture or constant memory). Copyright © 2012 John Wiley & Sons, Ltd.
Design and synthesis of 1,3‐dicapryloyl‐2‐acetylglycerol as molecular probe for triacylglycerol metabolism study
Authors: Lei Qiong , Lee Wilson Liangwei , Li Tianhu
Published: October 2012

The increasing number of health issues caused by obesity and lack of healthy and efficient fat substitutes require development on new fat substitute. This study proposes a new potential reduced‐calorie structured triacylglycerol (TAG) of “1,3‐medium‐chain, 2‐short‐chain triglycerides (MSM)” configuration, and the fat substitution method is based on the suppression of 2‐monoacylglycerol absorption into intestinal cells, which would decrease the recombination of TAG and reduce lipid absorption in the digestive tract. A molecular probe, 1,3‐dicapryloyl‐2‐acetylglycerol, is offered for nutritionists to conduct further study on its metabolism in human body. The synthesis method for this structured TAG starts from the lipase‐catalyzed esterification between glycerol and caprylic acid, yielding 1,3‐dicapryloylglycerol, and is followed by direct esterification with acetic anhydride to form 1,3‐dicapryloyl‐2‐acetylglycerol. Its structure is characterized by FTIR,1H NMR,13C NMR, and LC‐ESI‐MS.

Practical application: This kind of pure structured triglyceride can function as a molecular probe for nutritionists to test its metabolism in human body and conduct further evaluation on their fat substitute potential. The synthesis method can also be easily adopted by food industry since it involves only two simple reaction steps.
Absolute Configuration of Highly Flexible Natural Products by the Solid‐State ECD/TDDFT Method: Ximaolides and Sinulaparvalides
Authors: Kurtán Tibor , Jia Rui , Li Yan , Pescitelli Gennaro , Guo Yue‐Wei
Published: October 2012

The quantum‐mechanical calculation of chiroptical properties such as electronic circular dichroism (ECD) is an increasingly popular tool for establishing the absolute configuration of organic compounds, including natural products. However, this approach is often limited by conformational flexibility, which can be overcome by considering the solid crystalline state instead of solution. By knowing the solid‐state geometry, one may employ it as the input structure for ECD calculations and then comparing this with the ECD spectrum measured on a microcrystalline sample. We report here the application of this solid‐state ECD approach to establish the absolute configuration of three natural products, namely ximaolide A, sinulaparvalide A and B; all display pronounced flexibility and belong to two families of compounds with remarkable biological activity. The present configurational assignment may also be extended to several analogues whose absolute configurations have not yet been reported.
Synthesis of Pyrimidine‐Modified NHC Ruthenium‐Alkylidene Catalysts and Their Application in RCM, CM, EM and ROMP Reactions
Authors: Wu Guang‐Long , Cao Sheng‐Li , Chen Jian , Chen Zili
Published: October 2012

A new type of N‐heterocyclic carbene bearing ruthenium olefin metathesis catalyst was prepared through the incorporation of a chelated pyrimidinyl methylene subunit, in which electron‐rich substituents were attached to stabilize the ruthenium complexes. These catalysts were successfully used in various types of olefin metathesis reactions, including ring‐closing metathesis (RCM), cross‐metathesis (CM), enyne metathesis (EM), and ring‐opening metathesis polymerization (ROMP) reactions. The results therein showed that the presence of an electron‐deficient pyrimidine structure greatly enhanced the new NHC ruthenium complexes' catalytic activities.
A Potentiometric Sensor for Cd2+ Based on Carbon Nanotube Paste Electrode Constructed from Room Temperature Ionic Liquid, Ionophore and Silica Nanoparticles
Authors: Afkhami Abbas , Bagheri Hasan , Shirzadmehr Ali , Khoshsafar Hosein , Hashemi Pegah
Published: October 2012

A novel and effective potentiometric sensor for the rapid determination of Cd2+ based on carbon paste electrode consisting of the room temperature ionic liquid 1‐butyl‐3‐methylimidazolium hexafluorophosphate, multiwalled carbon nanotubes, silica nanoparticles and ionophore was constructed. The prepared composite has a low potential drift, high selectivity and fast response time, which leads to a more stable potential signal. A linear dynamic range of 4.50×10−9–1.00×10−1 mol L−1 with a detection limit of 2.00×10−9 mol L−1 was obtained. The modified electrode was successfully applied to the accurate determination of trace amounts of Cd2+ in environmental and biological samples.
Nanomolar Determination of Penicillamine by Using a Novel Cobalt/Polyaniline/Carbon Paste Nanocomposite Electrode
Authors: Amiri Mandana , Nekoiean Khadijeh , Bezaatpour Abolfazl
Published: October 2012

The fabrication of cobalt/polyaniline nanocomposite was performed using a simple chemical method. It was characterized by using TEM and FTIR techniques. The nanocomposite was applied as a modifier in a carbon paste electrode for selective determination of penicillamine. Penicillamine reacts with emeraldine polyaniline by using 1,4, Michael addition reaction. It can decrease the voltammetric peak current of emeraldine polyaniline. The effects of pH and potential sweep rate on the response of the electrode were investigated. Differential pulse voltammetry was applied for quantitative determination. Dynamic linear ranges were obtained in the ranges of 1.0×10−8–1.0×10−7 mol L−1 and 1.0×10−9–1.0×10−8 mol L−1.
Hydroxyanthraquinones Carminic Acid and Chrysazin Anodic Oxidation
Authors: de Souza Gil Eric , de Oliveira Severino Carlos B. , de Oliveira‐Brett Ana Maria
Published: October 2012

The anodic oxidation of the hydroxyanthraquinones carminic acid (CA) and chrysazin (CR) was investigated. The oxidation of CA proceeds in a pH‐dependent cascade mechanism, concerning the hydroquinone, the catechol and the 3‐OH groups in the anthraquinone moiety. The oxidation of the hydroquinone following the catechol electron‐donating groups occurs first at low positive potentials, the 3‐OH group is oxidized irreversibly at a higher potential. The oxidation of CR is pH‐dependent and occurs in successive steps. Oxidation of the hydroquinone tautomer in the CR‐ring occurs first, and the symmetrical 1‐OH and 8‐OH groups are irreversibly oxidized at the same higher potential.
Porous Nanostructured Metals for Electrocatalysis
Authors: Guo Dao‐Jun , Ding Yi
Published: October 2012

Nanoporous metals have been used to enhance electrocatalysis. The origin of their capability is understood on the basis of enlarged surface area. On the other hand, the nanoconfined space of nanoporous metals can significantly affect the electrochemical efficiency. Moreover, molecular dynamics in nanoconfined spaces is capable of offering much more chances of interaction between a redox molecule and a metal surface. These unique properties come from simply nanoporous structure and suggest new opportunity to innovative electrocatalysts in the future. This review addresses recent advances in the field of nanoporous metals and discusses respective important electrocatalytic applications.
Recent advances in the combination of capillary electrophoresis with mass spectrometry: From element to single‐cell analysis
Authors: Klepárník Karel
Published: October 2012

This overview deals with the latest development of electrophoresis in capillaries and microfluidic devices coupled to MS detection. A wide selection of relevant articles covers the literature published from January 2010 till June 2012 as a continuation of the review article on the same topic by Pantuckova et al. [Electrophoresis 2011, 32, 43–51]. Special attention is paid to the new improvements in instrumentation and methodology of three interfacing methods, ESI, matrix‐assisted desorption/ionization, and ICP. Representative examples illustrate applications in the proteomics, glycomics, metabolomics, biomarker research, forensics, pharmacology, food analysis and single‐cell analysis. The combinations of MS with capillary versions of electrochromatography, ITP, IEF, and micellar electrokinetic chromatography are not included.
Missing from the Institutional Data Picture: Non‐Tenure‐Track Faculty
Authors: Kezar Adrianna , Maxey Daniel
Published: October 2012

This chapter describes the characteristics of non‐tenure‐track faculty, which now make up the majority of faculty on campuses; highlights the importance of reporting complete data; and calls upon institutional researchers to contribute to addressing this growing segment of the faculty.
Phosphorylation of NuMA by Aurora‐A kinase in PC‐3 prostate cancer cells affects proliferation, survival, and interphase NuMA localization
Authors: Toughiri Raheleh , Li Xiang , Du Quansheng , Bieberich Charles J.
Published: October 2012

Aurora‐A is a serine/threonine kinase that has oncogenic properties in vivo. The expression and kinase activity of Aurora‐A are up‐regulated in multiple malignancies. Aurora‐A is a key regulator of mitosis that localizes to the centrosome from the G2 phase through mitotic exit and regulates mitotic spindle formation as well as centrosome separation. Overexpression of Aurora‐A in multiple malignancies has been linked to higher tumor grade and poor prognosis through mechanisms that remain to be defined. Using an unbiased proteomics approach, we identified the protein nuclear mitotic apparatus (NuMA) as a robust substrate of Aurora‐A kinase. Using a small molecule Aurora‐A inhibitor in conjunction with a reverse in‐gel kinase assay (RIKA), we demonstrate that NuMA becomes hypo‐phosphorylated in vivo upon Aurora‐A inhibition. Using an alanine substitution strategy, we identified multiple Aurora‐A phospho‐acceptor sites in the C‐terminal tail of NuMA. Functional analyses demonstrate that mutation of three of these phospho‐acceptor sites significantly diminished cell proliferation. In addition, alanine mutation at these sites significantly increased the rate of apoptosis. Using confocal immunofluorescence microscopy, we show that the NuMA T1804A mutant mis‐localizes to the cytoplasm in interphase nuclei in a punctate pattern. The identification of Aurora‐A phosphorylation sites in NuMA that are important for cell cycle progression and apoptosis provides new insights into Aurora‐A function. J. Cell. Biochem. 114: 823–830, 2013. © 2012 Wiley Periodicals, Inc.
Sodium valproate potentiates staurosporine‐induced apoptosis in neuroblastoma cells via Akt/survivin independently of HDAC inhibition
Authors: Shah Reecha D. , Jagtap Jayashree C. , Mruthyunjaya S. , Shelke Ganesh V. , Pujari Radha , Das Gowry , Shastry Padma
Published: October 2012

Sodium valproate (VPA) has been recently identified as a selective class I histone deacetylase (HDAC) inhibitor and explored for its potential as an anti‐cancer agent. The anti‐cancer properties of VPA are generally attributed to its HDAC inhibitory activity indicating a clear overlap of these two actions, but the underlying mechanisms of its anti‐tumor effects are not clearly elucidated. The present study aimed to delineate the molecular mechanism of VPA in potentiating cytotoxic effects of anti‐cancer drugs with focus on inhibition of HDAC activity. Using human neuroblastoma cell lines, SK‐N‐MC, SH‐SY5Y, and SK‐N‐SH, we show that non‐toxic dose (2 mM) of VPA enhanced staurosporine (STS)‐induced cell death as assessed by MTT assay, PARP cleavage, hypodiploidy, and caspase 3 activity. Mechanistically, the effect of VPA was mediated by down regulation of survivin, an anti‐apoptotic protein crucial in resistance to STS‐mediated cytotoxicity, through Akt pathway. Knock down of class I HDAC isoforms remarkably inhibited HDAC activity comparable with that of VPA but had no effect on STS‐induced apoptosis. Moreover, MS‐275, a structurally distinct class I HDAC inhibitor did not affect STS‐mediated apoptosis, nor decrease the levels of survivin and Akt. Valpromide (VPM), an amide analog of VPA that does not inhibit HDAC also potentiated cell death in NB cells associated with decreased survivin and Akt levels suggesting that HDAC inhibition might not be crucial for STS‐induced apoptosis. The study provides new information on the possible molecular mechanism of VPA in apoptosis that can be explored in combination therapy in cancer. J. Cell. Biochem. 114: 854–863, 2013. © 2012 Wiley Periodicals, Inc.
Exendin‐4 inhibits iNOS expression at the protein level in LPS‐stimulated Raw264.7 macrophage by the activation of cAMP/PKA pathway
Authors: Chang Seo‐Yoon , Kim Dong‐Bin , Ryu Gyeong Ryul , Ko Seung‐Hyun , Jeong In‐Kyung , Ahn Yu‐Bae , Jo Yang‐Hyeok , Kim Myung‐Jun
Published: October 2012

Glucagon‐like peptide‐1 (GLP‐1) and its potent agonists have been widely studied in pancreatic islet β‐cells. However, GLP‐1 receptors are present in many extrapancreatic tissues including macrophages, and thus GLP‐1 may have diverse actions in these tissues and cells. Therefore, we examined the mechanism by which exendin‐4 (EX‐4), a potent GLP‐1 receptor agonist, inhibits lipopolysaccharide (LPS)‐induced iNOS expression in Raw264.7 macrophage cells. EX‐4 significantly inhibited LPS‐induced iNOS protein expression and nitrite production. However, Northern blot and promoter analyses demonstrated that EX‐4 did not inhibit LPS‐induced iNOS mRNA expression and iNOS promoter activity. Electrophoretic mobility shift assay (EMSA) showed that EX‐4 did not alter the binding activity of NF‐κB to the iNOS promoter. Consistent with the result of EMSA, LPS‐induced IκBα phosphorylation and nuclear translocation of p65 were not inhibited by EX‐4. Also, actinomycin D chase study and the promoter assay using the construct containing 3′‐untranslated region of iNOS showed that EX‐4 did not affect iNOS mRNA stability. Meanwhile, cycloheximide chase study demonstrated that EX‐4 significantly accelerated iNOS protein degradation. The EX‐4 inhibition of LPS‐induced iNOS protein was significantly reversed by adenylate cyclase inhibitors (MDL‐12330A and SQ 22536), a PKA inhibitor (H‐89) and PKAα gene silencing. These findings suggest that EX‐4 inhibited LPS‐induced iNOS expression at protein level, but not at transcriptional mechanism of iNOS gene and this inhibitory effect of EX‐4 was mainly dependent on cAMP/PKA system. J. Cell. Biochem. 114: 844–853, 2013. © 2012 Wiley Periodicals, Inc.
Stem cells as promising therapeutic options for neurological disorders
Authors: Yoo Jongman , Kim Han‐Soo , Hwang Dong‐Youn
Published: October 2012

Due to the limitations of pharmacological and other current therapeutic strategies, stem cell therapies have emerged as promising options for treating many incurable neurologic diseases. A variety of stem cells including pluripotent stem cells (i.e., embryonic stem cells and induced pluripotent stem cells) and multipotent adult stem cells (i.e., fetal brain tissue, neural stem cells, and mesenchymal stem cells from various sources) have been explored as therapeutic options for treating many neurologic diseases, and it is becoming obvious that each type of stem cell has pros and cons as a source for cell therapy. Wise selection of stem cells with regard to the nature and status of neurologic dysfunctions is required to achieve optimal therapeutic efficacy. To this aim, the stem cell‐mediated therapeutic efforts on four major neurological diseases, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis, and stroke, will be introduced, and current problems and future directions will be discussed. J. Cell. Biochem. 114: 743–753, 2013. © 2012 Wiley Periodicals, Inc.
Multilayer appearance on contrast‐enhanced susceptibility‐weighted images on patients with brain abscesses: Possible origins and effects of postprocessing
Authors: Chang Hing‐Chiu , Chuang Tzu‐Chao , Chung Hsiao‐Wen , Lin Huey‐Shyan , Lai Ping‐Hong , Weng Mei‐Jui , Fu Jui‐Hsun , Wang Po‐Chin , Li Shang‐Chieh , Pan Huay‐Ben
Published: October 2012

Purpose:

To demonstrate the presence of a multilayer appearance of the capsule on contrast‐enhanced (CE) susceptibility‐weighted imaging (SWI) in patients with pyogenic brain abscesses. Possible origins for the appearance and effects of postprocessing settings are discussed.

Materials and Methods:

Fourteen patients with pyogenic brain abscesses underwent post gadolinium‐enhanced SWI at 1.5 T. All SWI images were postprocessed with various filter and mask settings to compare the image appearance. Computer simulations using a paramagnetic spherical shell model were performed to verify the clinical findings.

Results:

Pyogenic brain abscesses demonstrated a multilayer appearance with a darkened ring within the enhanced capsule on CE‐SWI in all patients. The multilayer appearance was slice‐orientation‐dependent, decreased with larger widths of the high‐pass filter, and increased with larger numbers of phase mask multiplication operations, consistently on both simulation results and the clinical images.

Conclusion:

CE‐SWI shows the multilayer appearance of the capsule in pyogenic brain abscesses, which may arise from postprocessing procedures originally designed to enhance susceptibility contrast. Although SWI may provide additional information valuable in the diagnosis of pyogenic brain abscesses, image interpretation should be exercised with caution, particularly for CE‐SWI. J. Magn. Reson. Imaging 2012; 36:1353–1361. © 2012 Wiley Periodicals, Inc.
High performance of a new PCR‐based urine assay for HPV‐DNA detection and genotyping
Authors: Tanzi Elisabetta , Bianchi Silvia , Fasolo Maria Michela , Frati Elena R. , Mazza Francesca , Martinelli Marianna , Colzani Daniela , Beretta Rosangela , Zappa Alessandra , Orlando Giovanna
Published: October 2012

Human papillomavirus (HPV) testing has been proposed as a means of replacing or supporting conventional cervical screening (Pap test). However, both methods require the collection of cervical samples. Urine sample is easier and more acceptable to collect and could be helpful in facilitating cervical cancer screening. The aim of this study was to evaluate the sensitivity and specificity of urine testing compared to conventional cervical smear testing using a PCR‐based method with a new, designed specifically primer set. Paired cervical and first voided urine samples collected from 107 women infected with HIV were subjected to HPV‐DNA detection and genotyping using a PCR‐based assay and a restriction fragment length polymorphism method. Sensitivity, specificity, Positive Predictive Value (PPV), and Negative Predictive Value (NPV) were calculated using the McNemar's test for differences. Concordance between tests was assessed using the Cohen's unweighted Kappa (k). HPV DNA was detected in 64.5% (95% CI: 55.1–73.1%) of both cytobrush and urine samples. High concordance rates of HPV‐DNA detection (k = 0.96; 95% CI: 0.90–1.0) and of high risk‐clade and low‐risk genotyping in paired samples (k = 0.80; 95% CI: 0.67–0.92 and k = 0.74; 95% CI: 0.60–0.88, respectively) were observed. HPV‐DNA detection in urine versus cervix testing revealed a sensitivity of 98.6% (95% CI: 93.1–99.9%) and a specificity of 97.4% (95% CI: 87.7–99.9%), with a very high NPV (97.4%; 95% CI: 87.7–99.9%). The PCR‐based assay utilized in this study proved highly sensitive and specific for HPV‐DNA detection and genotyping in urine samples. These data suggest that a urine‐based assay would be a suitable and effective tool for epidemiological surveillance and, most of all, screening programs. J. Med. Virol. 85:91–98, 2012. © 2012 Wiley Periodicals, Inc.
Human metapneumovirus associated with community‐acquired pneumonia in children in Beijing, China
Authors: Lu Guilan , Li Jianguo , Xie Zhengde , Liu Chunyan , Guo Li , Vernet Guy , Shen Kunling , Wang Jianwei
Published: October 2012

Community‐acquired pneumonia is a major cause of morbidity and mortality in children worldwide. However, few studies have been conducted on the infection of human metapneumovirus (hMPV) associated with pediatric community‐acquired pneumonia in China. Nasopharyngeal aspirates were collected between July 2008 and June 2010 from 1,028 children, aged ≤16.5 years, who were diagnosed with community‐acquired pneumonia in Beijing, China. Reverse‐transcriptase polymerase chain reaction was used to screen the samples for hMPV and common respiratory viruses. hMPV was detected in 6.3% of the patients with community‐acquired pneumonia. This detection rate is the third highest for a respiratory virus in children with community‐acquired pneumonia, after that of rhinovirus (30.9%) and respiratory syncytial virus (30.7%). The detection rate of hMPV in 2008/2009 (42/540, 7.8%) was significantly higher than in 2009/2010 (23/488, 4.7%; χ2 = 4.065, P = 0.044). The hMPV subtypes A2, B1, and B2 were found to co‐circulate, with A2 being most prevalent. These results indicate that hMPV plays a substantial role in pediatric community‐acquired pneumonia in China. Overall, these findings provide a better understanding of the epidemiological and clinical features of hMPV infections. J. Med. Virol. 85:138–143, 2012. © 2012 Wiley Periodicals, Inc.
In vivo implant fixation of carbon fiber‐reinforced PEEK hip prostheses in an ovine model
Authors: Nakahara Ichiro , Takao Masaki , Bandoh Shunichi , Bertollo Nicky , Walsh William R , Sugano Nobuhiko
Published: October 2012

Carbon fiber‐reinforced polyetheretherketone (CFR/PEEK) is theoretically suitable as a material for use in hip prostheses, offering excellent biocompatibility, mechanical properties, and the absence of metal ions. To evaluate in vivo fixation methods of CFR/PEEK hip prostheses in bone, we examined radiographic and histological results for cementless or cemented CFR/PEEK hip prostheses in an ovine model with implantation up to 52 weeks. CFR/PEEK cups and stems with rough‐textured surfaces plus hydroxyapatite (HA) coatings for cementless fixation and CFR/PEEK cups and stems without HA coating for cement fixation were manufactured based on ovine computed tomography (CT) data. Unilateral total hip arthroplasty was performed using cementless or cemented CFR/PEEK hip prostheses. Five cementless cups and stems and six cemented cups and stems were evaluated. On the femoral side, all cementless stems demonstrated bony ongrowth fixation and all cemented stems demonstrated stable fixation without any gaps at both the bone‐cement and cement‐stem interfaces. All cementless cases and four of the six cemented cases showed minimal stress shielding. On the acetabular side, two of the five cementless cups demonstrated bony ongrowth fixation. Our results suggest that both cementless and cemented CFR/PEEK stems work well for fixation. Cup fixation may be difficult for both cementless and cemented types in this ovine model, but bone ongrowth fixation on the cup was first seen in two cementless cases. Cementless fixation can be achieved using HA‐coated CFR/PEEK implants, even under load‐bearing conditions. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31: 485–492, 2013
Mechanical effectiveness of lateral foot wedging in medial knee osteoarthritis after 1 year of wear
Authors: Barrios Joaquin A. , Butler Robert J. , Crenshaw Jeremy R. , Royer Todd D. , Davis Irene S.
Published: October 2012

The use of lateral foot wedging in the management of medial knee osteoarthritis is under scrutiny. Interestingly, there have been minimal efforts to evaluate biomechanical effectiveness with long‐term use. Therefore, we aimed to evaluate dynamic knee loading (assessed using the knee adduction moment) and other secondary gait parameters in patients with medial knee osteoarthritis wearing lateral foot wedging at a baseline visit and after 1 year of wear. Three‐dimensional gait data were captured in an intervention group of 19 patients with symptomatic medial knee osteoarthritis wearing their prescribed laterally wedged foot orthoses at 0 and 12 months. Wedge amounts were prescribed based on symptom response to a step‐down test. A control group of 19 patients wearing prescribed neutral orthoses were also captured at 0 and 12 months. The gait of the intervention group wearing neutral orthoses was additionally captured. Walking speed and shoes were controlled. Analyses of variance were conducted to examine for group‐by‐time (between the groups in their prescribed orthoses) and condition‐by‐time (within the intervention group) interactions, main effects, and simple effects. We observed increased knee adduction moments and frontal plane motion over time in the control group but not the intervention group. Further, within the intervention group, the mechanical effectiveness of the lateral wedging did not decrease. In patients with medial knee osteoarthritis, the effects of lateral foot wedging on pathomechanics associated with medial knee osteoarthritis were favorable and sustained over time. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31: 659–664, 2013