bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel Nanorod Precipitate Formation in Neodymium and Titanium Codoped Bismuth Ferrite
Authors: MacLaren Ian , Wang Li Qiu , Schaffer Bernhard , Ramasse Quentin M. , Craven Alan J. , Selbach Sverre M. , Spaldin Nicola A. , Miao Shu , Kalantari Kambiz , Reaney Ian M.
Published: September 2012

The discovery of unusual nanorod precipitates in bismuth ferrite doped with Nd and Ti is reported. The atomic structure and chemistry of the nanorods are determined using a combination of high angle annular dark field imaging, electron energy loss spectroscopy, and density functional calculations. It is found that the structure of the BiFeO3 matrix is strongly modified adjacent to the precipitates; the readiness of BiFeO3 to adopt different structural allotropes in turn explains why such a large axial ratio, uncommon in precipitates, is stabilized. In addition, a correlation is found between the alignment of the rods and the orientation of ferroelastic domains in the matrix, which is consistent with the system's attempt to minimize its internal strain. Density functional calculations indicate a finite density of electronic states at the Fermi energy within the rods, suggesting enhanced electrical conductivity along the rod axes, and motivating future investigations of nanorod functionalities.
Pure dissolution kinetics of anhydrite and gypsum in inhibiting aqueous salt solutions
Authors: Pachon‐Rodriguez Edgar Alejandro , Colombani Jean
Published: September 2012

In the context of the study of the wet creep of plasterboards, digital holographic interferometry measurements have been performed of the dissolution of gypsum of various quarries in water and in aqueous solutions of salts inhibiting dissolution and of the dissolution of anhydrite in water. This technique is carried out in still water and permits to observe directly the reacting solid–liquid interface. Therefore, contrary to standard bulk measurements, the pure dissolution rate constants, free from any mass transport contribution, have been measured. These rate constants are similar for the cleavage face of the various gypsums. Thanks to their faculty of complexing the surface calcium ions, the investigated phosphate and phosphonate salts inhibit dissolution and reduce the dissolution rate constant of up to more than one order of magnitude. This strong influence may explain their anticreep role in plasterboards. © 2012 American Institute of Chemical Engineers AIChE J, 59: 1622–1626, 2013
The Head and Neck Muscles of the Serval and Tiger: Homologies, Evolution, and Proposal of a Mammalian and a Veterinary Muscle Ontology
Authors: Diogo Rui , Pastor Francisco , De Paz Felix , Potau Josep M. , Bello‐Hellegouarch Gaëlle , Ferrero Eva M. , Fisher Rebecca E.
Published: September 2012

Here we describe the head and neck muscles of members of the two extant felid subfamilies (Leptailurus serval: Felinae; Panthera tigris: Pantherinae) and compare these muscles with those of other felids, other carnivorans (e.g., domestic dogs), other eutherian mammals (e.g., rats, tree‐shrews and modern humans), and noneutherian mammals including monotremes. Another major goal of the article is to discuss and help clarify nomenclatural discrepancies found in the Nomina Anatomica Veterinaria and in veterinary atlases and textbooks that use cats and dogs as models to understand the anatomy of domestic mammals and to stress differences with modern humans. We propose a unifying nomenclature that is expanded to all the head and neck muscles and to all mammalian taxa in order to help build veterinary and mammalian muscle ontologies. Our observations and comparisons and the specific use of this nomenclature point out that felids such as tigers and servals and other carnivorans such as dogs have more facial muscle structures related to the mobility of both the auricular and orbital regions than numerous other mammals, including modern humans, which might be the result of an ancient adaptation related to the remarkable predatory capacities of carnivorans. Interestingly, the skeletal differences, mainly concerning the hyoid apparatus, pharynx, and larynx, that are likely associated with the different types of vocalizations seen in the Felinae (mainly purring) and Pantherinae (mainly roaring) are not accompanied by clear differences in the musculature connected to these structures in the feline L. serval and the pantherine P. tigris. Anat Rec, 2012. © 2012 Wiley Periodicals, Inc.
Discordance between pain and radiographic severity in knee osteoarthritis: Findings from quantitative sensory testing of central sensitization
Authors: Finan Patrick H. , Buenaver Luis F. , Bounds Sara C. , Hussain Shahid , Park Raymond J. , Haque Uzma J. , Campbell Claudia M. , Haythornthwaite Jennifer A. , Edwards Robert R. , Smith Michael T.
Published: September 2012

Objective

Radiographic measures of the pathologic changes of knee osteoarthritis (OA) have shown modest associations with clinical pain. We sought to evaluate possible differences in quantitative sensory testing (QST) results and psychosocial distress profiles between knee OA patients with discordant versus congruent clinical pain reports relative to radiographic severity measures.

Methods

A total of 113 participants (66.7% women; mean ± SD age 61.05 ± 8.93 years) with knee OA participated in the study. Radiographic evidence of joint pathology was graded according to the Kellgren/Lawrence scale. Central sensitization was indexed through quantitative sensory testing, including heat and pressure–pain thresholds, tonic suprathreshold pain (cold pressor test), and repeated phasic suprathreshold mechanical and thermal pain. Subgroups were constructed by dichotomizing clinical knee pain scores (median split) and knee OA grade scores (grades 1–2 versus 3–4), resulting in 4 groups: low pain/low knee OA grade (n = 24), high pain/high knee OA grade (n = 32), low pain/high knee OA grade (n = 27), and high pain/low knee OA grade (n = 30).

Results

Multivariate analyses revealed significantly heightened pain sensitivity in the high pain/low knee OA grade group, while the low pain/high knee OA grade group was less pain‐sensitive. Group differences remained significant after adjusting for differences on psychosocial measures, as well as age, sex, and race.

Conclusion

The results suggest that central sensitization in knee OA is especially apparent among patients with reports of high levels of clinical pain in the absence of moderate‐to‐severe radiographic evidence of pathologic changes of knee OA.
A Perceptual–Motor Deficit Predicts Social and Communicative Impairments in Individuals With Autism Spectrum Disorders
Authors: Linkenauger Sally A. , Lerner Matthew D. , Ramenzoni Verónica C. , Proffitt Dennis R.
Published: September 2012

Individuals with autism spectrum disorders (ASDs) have known impairments in social and motor skills. Identifying putative underlying mechanisms of these impairments could lead to improved understanding of the etiology of core social/communicative deficits in ASDs, and identification of novel intervention targets. The ability to perceptually integrate one's physical capacities with one's environment (affordance perception) may be such a mechanism. This ability has been theorized to be impaired in ASDs, but this question has never been directly tested. Crucially, affordance perception has shown to be amenable to learning; thus, if it is implicated in deficits in ASDs, it may be a valuable unexplored intervention target. The present study compared affordance perception in adolescents and adults with ASDs to typically developing (TD) controls. Two groups of individuals (adolescents and adults) with ASDs and age‐matched TD controls completed well‐established action capability estimation tasks (reachability, graspability, and aperture passability). Their caregivers completed a measure of their lifetime social/communicative deficits. Compared with controls, individuals with ASDs showed unprecedented gross impairments in relating information about their bodies' action capabilities to visual information specifying the environment. The magnitude of these deficits strongly predicted the magnitude of social/communicative impairments in individuals with ASDs. Thus, social/communicative impairments in ASDs may derive, at least in part, from deficits in basic perceptual–motor processes (e.g. action capability estimation). Such deficits may impair the ability to maintain and calibrate the relationship between oneself and one's social and physical environments, and present fruitful, novel, and unexplored target for intervention. Autism Res 2012,5:352–362. © 2012 International Society for Autism Research, Wiley Periodicals, Inc.
Repairing rat sciatic nerve injury by a nerve‐growth‐factor‐loaded, chitosan‐based nerve conduit
Authors: Wang Hongkui , Zhao Qing , Zhao Weijia , Liu Qiong , Gu Xiaosong , Yang Yumin
Published: September 2012

We have developed a nerve conduit made up of chitosan, on which nerve growth factor (NGF) was immobilized via genipin cross‐linking. The nerve conduit was used to bridge a 10‐mm‐long sciatic nerve gap in rats. At 24 weeks after surgery, electrophysiological assessment, behavioral analysis, and histological examination were conducted to evaluate the outcomes of peripheral nerve repair. The nerve conduit allowed nerve reconstruction between two stumps and reinnervation of the target gastrocnemius muscle. For two groups of rats repaired respectively by the nerve conduit and autologous nerve graft, the density of regenerated axons was 3.55 ± 0.51 and 3.91 ± 0.14 (P = 0.712), and the cross‐sectional area of target muscles was 1,159.68 ± 305.85 and 1,307.06 ± 301.25 (P = 0.922), respectively, without significant differences between the two groups. Our data suggest the feasibility of using chitosan‐based, NGF‐loaded nerve conduits for peripheral nerve repair.
Separation and determination of anesthetics by capillary electrophoresis with mixed micelles of sodium dodecyl sulfate and Tween 20 using electrochemiluminescence detection
Authors: Liu Yan‐Ming , Li Jie , Yang Yang , Du Jun‐Jun
Published: September 2012

A simple and new method for the simultaneous determination of procaine (Pro), lidocaine (Lid), ropivacaine (Rop) and bupivacaine (Bup) was developed using capillary electrophoresis separation with mixed micelles and electrochemiluminescence detection. The use of mixed micelles of 2.0 × 10–3 mol/L sodium dodecyl sulfate (SDS) and 8.0 × 10–3 mol/L Tween 20 greatly improved separation selectivity. The detection sensitivities of four drugs with a Pt working electrode were increased by modification of the Pt electrode with europium(III)–doped Prussian Blue analog (Eu–PB). Under optimal conditions, the four local anesthetics were well separated and detected. The limits of detection (LOD, S/N = 3) of Pro, Lid, Rop and Bup in standard solution are 2.5 × 10–8, 1.3 × 10–8, 3.0 × 10–8 and 4.1 × 10–8 mol/L, respectively. The limits of quantitation (LOQ, S/N = 10) of Pro, Lid, Rop and Bup are 2.3 × 10–7, 1.2 × 10–7, 3.7 × 10–7 and 5.6 × 10–7 mol/L in a human urine sample, and 8.5 × 10–7, 6.9 × 10–7, 2.8 × 10–6 and 1.1 × 10–6 mol/L in a human serum sample, respectively. The recoveries of four drugs at different spiked concentrations in human urine and serum samples were between 86.5 and 107.6%. The proposed method has been successfully applied to determine local anesthetics in biofluids. Copyright © 2012 John Wiley & Sons, Ltd.
Systematic review of intravenous methylene blue in parathyroid surgery
Authors: Patel H P , Chadwick D R , Harrison B J , Balasubramanian S P
Published: September 2012

Background

Methylene blue is an intraoperative adjunct for localization of enlarged parathyroid glands. The availability of preoperative and other intraoperative localization methods, and the reported adverse effects of methylene blue make its routine use debatable. The aim of this study was to perform a systematic review of the use of methylene blue in parathyroidectomy.

Methods

A systematic review of English-language literature in MEDLINE and Scopus databases on the use of intravenous methylene blue in parathyroid surgery was carried out.

Results

There were no randomized clinical trials. Thirty-nine observational studies were identified, of which 33 did not have a control arm. The overall median staining rate for abnormal parathyroid glands was 100 per cent. The median cure rates in the methylene blue and no-methylene blue arms were 100 and 98 per cent respectively. Neurotoxicity was reported in 25 patients, all of whom were taking serotonergic medication.

Conclusion

Observational evidence suggests that methylene blue is efficacious in identifying enlarged parathyroid glands. Toxicity appears to be mild in the absence of concomitant use of serotonin reuptake inhibitors. The effectiveness of methylene blue in the context of currently used preoperative and intraoperative localization techniques has yet to be shown.
Systematic review of single-incision laparoscopic colonic surgery
Authors: Fung A K-Y , Aly E H
Published: September 2012

Background

Randomized clinical trials (RCTs) have shown multiport laparoscopic surgery to be safe compared with open surgery in elective colonic disease. Single-incision laparoscopic surgery (SILS) represents the latest advance in laparoscopic surgery. The aim of this systematic review was to establish the safety and complication profile of colonic SILS.

Methods

The search was performed in October 2011 using PubMed, MEDLINE, Embase and the Cochrane Central Register of Controlled Trials. Search terms were ‘colorectal’, ‘colon’, ‘colectomy’, ‘rectal’ and single incision/port/trocar/site/scar. Only pure single-incision laparoscopic colonic surgery for benign and malignant colonic disease was included. Primary outcomes were the early postoperative complication profiles of colonic SILS. Secondary outcomes were duration of operation, lymph node yields, conversion rate and duration of hospital stay.

Results

Colonic SILS data were compared with data from a Cochrane review on the short-term outcomes of laparoscopic colonic surgery and four main RCTs on laparoscopic colonic surgery. Median operating times and time to first bowel motion for colonic SILS were comparable with those for laparoscopic colonic surgery. The median lymph node retrieval for malignant disease achieved with SILS was acceptable. Evidence for a reduction in postoperative pain with SILS was conflicting. There was no significant reduction in length of hospital stay with SILS. Most patients selected for colonic SILS had a low body mass index, non-bulky tumours and were operated on by experienced laparoscopic surgeons. There was significant heterogeneity in study group characteristics, indications for surgery, research methodology, operative techniques and follow-up time.

Conclusion

Colonic SILS should be restricted to highly selected patients; operations should be performed by experienced laparoscopic surgeons, with critical appraisal of clinical outcomes.
Transanal glove port is a safe and cost-effective alternative for transanal endoscopic microsurgery
Authors: Hompes R , Ris F , Cunningham C , Mortensen N J , Cahill R A
Published: September 2012

Background

Transanal endoscopic microsurgery (TEM) is a minimally invasive technique for excision of rectal tumours that avoids conventional pelvic resectional surgery along with its risks and side-effects. Although appealing, the associated cost and complex learning curve limit TEM utilization by colorectal surgeons. Single-port laparoscopic principles are being recognized as transferable to transanal work and hybrid techniques are in evolution. Here the clinical application of a new technique for transanal access is reported.

Methods

Consecutive non-selected patients eligible for TEM over a 3-month period (and selected patients thereafter) were offered a procedure performed via a ‘glove TEM port’. This access device was constructed on-table using a circular anal dilator (CAD), wound retractor and standard surgical glove, along with standard, straight laparoscopic trocar sleeves and instruments.

Results

Fourteen patients underwent full-thickness resection of benign (8) or malignant (6) rectal pathology. CAD insertion failed in one patient and conventional TEM assistance was needed in another, leaving 12 procedures completed successfully by glove TEM alone as planned (completion rate 86 per cent overall, 92 per cent after initiation). The median (range) duration of operation and resected specimen area were 93 (30–120) min and 12 (3–152) cm2 respectively. There was no intraoperative and minimal postoperative morbidity, with a median follow-up of 5·7 (2·7–9·4) months.

Conclusion

The glove TEM port is a safe, inexpensive and readily available access tool that may obviate the use of specialized equipment for transanal resection of rectal lesions.
Twenty years of experience with laparoscopic antireflux surgery
Authors: Engström C , Cai W , Irvine T , Devitt P G , Thompson S K , Game P A , Bessell J R , Jamieson G G , Watson D I
Published: September 2012

Background

There are few reports of large patient cohorts with long-term follow-up after laparoscopic antireflux surgery. This study was undertaken to evaluate changes in surgical practice and outcomes for laparoscopic antireflux surgery over a 20-year period.

Methods

A standardized questionnaire, prospectively applied annually, was used to determine outcome for all patients undergoing laparoscopic fundoplication in two centres since commencing this procedure in 1991. Visual analogue scales ranging from 0 to 10 were used to assess symptoms of heartburn, dysphagia and satisfaction with overall outcome. Data were analysed to determine outcome across 20 years.

Results

From 1991 to 2010, 2261 consecutive patients underwent laparoscopic fundoplication at the authors' institutions. Follow-up ranged from 1 to 19 (mean 7·6) years. Conversion to open surgery occurred in 73 operations (3·2 per cent). Revisional surgery was performed in 216 patients (9·6 per cent), within 12 months of the original operation in 116. There was a shift from Nissen to partial fundoplication across 20 years, and a recent decline in operations for reflux, offset by an increase in surgery for large hiatus hernia. Dysphagia and satisfaction scores were stable, and heartburn scores rose slightly across 15 years of follow-up. Heartburn scores were slightly higher and reoperation for reflux was more common after anterior partial fundoplication (P = 0·005), whereas dysphagia scores were lower and reoperation for dysphagia was less common (P < 0·001). At 10 years, satisfaction with outcome was similar for all fundoplication types.

Conclusion

Laparoscopic Nissen and partial fundoplications proved to be durable and achieved good long-term outcomes. At earlier follow-up, dysphagia was less common but reflux more common after anterior partial fundoplication, although differences had largely disappeared by 10 years.
Expression of a functional recombinant C‐type lectin‐like protein lebecetin in the human embryonic kidney cells
Authors: Jebali Jed , Jeanneau Charlotte , Morjen Maram , Mathieu Sylvie , Bazaa Amine , el Ayeb Mohamed , Luis José , Gargouri Ali , Marrakchi Naziha , el Battari Assou
Published: September 2012

Lebecetin is an anticoagulant C‐type lectin‐like protein that was previously isolated from Macrovipera lebetina venom and described to consist of two subunits (alpha and beta). It was reported to potently prevent platelet aggregation by binding to glycoprotein Ib and to exhibit a broad spectrum of inhibitory activities on various integrin‐mediated functions of tumor cells, including adhesion, proliferation, and cell migration. This study aimed to investigate the structure‐function of lebecetin. Accordingly, the cDNA of each subunit was cloned and separately or jointly expressed in the human embryonic kidney cells using two vectors with different selectable tags. The immunofluorescence analysis of transfected cells revealed significant expression levels and co‐localization of the two lebecetin subunits. The recombinant proteins were efficiently secreted and purified using metal‐chelating affinity chromatography. We found that the Lebecetin alpha and beta subunits were produced as a mixture of homodimers and heterodimers and that the heterodimerization represents a prerequisite for functioning. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2012
Evaluation of critical nutritional parameters and their significance in the production of rhamnolipid biosurfactants from Pseudomonas aeruginosa BS‐161R
Authors: Kumar Chityal Ganesh , Mamidyala Suman Kumar , Sujitha Pombala , Muluka Hemalatha , Akkenapally Surekha
Published: September 2012

Eleven biosurfactant producing bacteria were isolated from different petroleum‐contaminated soil and sludge samples. Among these 11 isolates, two were identified as promising, as they reduced the surface tension of culture medium to values below 27 mN m−1. Besides biosurfactant production property, they exhibited good flocculating activity. Microbacterium sp. was identified as a new addition to the list of biosurfactant and bioflocculant‐producers. Optimization of various conditions for rhamnolipid production was carried out for one of the promising isolate, Pseudomonas aeruginosa BS‐161R. Bioglycerol (2.5%), as a cheap renewable carbon source, attained better rhamnolipid yield, while sodium nitrate appeared to be the preferable nitrogen source. The optimum carbon to nitrogen (C/N) and carbon to iron (C/Fe) ratios achieved were 15 and 28,350, respectively, which favored rhamnolipid production. Physical parameters like pH, temperature, and agitation speed also affected the production of rhamnolipids. Results from shake flask optimization indicated that the concentration of bioglycerol, sodium nitrate, and iron were the most significant factors affecting rhamnolipid production, which was supported by the results of central composite rotatable design. After optimization of the culture conditions, the production of rhamnolipids increased by ninefold from 0.369 to 3.312 g L−1. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2012
Hepatoprotective effect of bis(4‐methylbenzoyl) diselenide against CCl4‐induced oxidative damage in mice
Authors: Filho Carlos Borges , Del Fabbro Lucian , Boeira Silvana P. , Furian Ana Flávia , Savegnago Lucielli , Soares Letiére Cabreira , Braga Antonio Luiz , Jesse Cristiano R.
Published: September 2012

From a pharmacological point of view, organoseleniums are compounds with important and interesting antioxidant and biological activities. The aim of this study was to evaluate the hepatoprotective effect of bis(4‐methylbenzoyl) diselenide (BMD) against carbon tetrachloride (CCl4)–induced oxidative damage in mice. The animals received BMD (25 mg/kg p.o., for 3 days), and after 1 day, CCl4 (1 mg/kg body weight) was administered by intraperitoneal route. One day after the CCl4 exposure, the animals were euthanized for biochemical and histological analysis. Treatment with BMD (25 mg/kg p.o.) protected against aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, gamma‐glutamyl transferase and lactate dehydrogenase activity increases induced by CCl4 plasma exposure. Treatment with BMD (25 mg/kg) protected against increases in thiobarbituric reactive species and decreasing non‐protein thiols and ascorbic acid levels in liver of mice. Catalase and superoxide dismutase activity inhibition in the liver caused by CCl4 were protected by treatment with BMD (25 mg/kg). Glutathione S‐transferase activity was inhibited by CCl4 and remained unaltered even after treatment with BMD. Sections of liver from CCl4‐exposed mice presented an intense infiltration of inflammatory cells and loss of the cellular architecture. BMD (25 mg/kg) attenuated CCl4‐induced hepatic histological alterations. The results demonstrated the hepatoprotective effects of BMD in the mouse liver, possibly by modulating the antioxidant status. Copyright © 2012 John Wiley & Sons, Ltd.
Over‐expression of circadian clock gene Bmal1 affects proliferation and the canonical Wnt pathway in NIH‐3T3 cells
Authors: Lin Fuwei , Chen Yijia , Li Xiaolong , Zhao Qing , Tan Zhen
Published: September 2012

Bmal1 is a transcription factor that plays a central role in the regulation of circadian rhythms. Recent study reported that Bmal1–/– mice displayed many known features of premature ageing, such as reduction of bone mass. Our previous study has found that both the proliferation of bone marrow mesenchymal stem cells (BMSCs) and Bmal1 expression decreased with advancing age. It seemed that a positive correlation existed between Bmal1 protein level and the proliferative activity of BMSCs. β‐catenin, the core factor of the canonical Wnt pathway, also showed reduced expression in aged mice. In order to further confirm this, we constructed a lentiviral vector to over‐express Bmal1 in NIH‐3T3 cells; successful transfection was verified. The cell proliferation rate of infected cells was higher than the non‐transfected NIH‐3T3 cells, suggesting that circadian clock gene Bmal1 can promote proliferation. β‐catenin showed an increased expression in NIH‐3T3 cells after Bmal1 over‐expression, indicating that activation of the canonical Wnt pathway might be the mechanism underlying the effect of circadian clock gene Bmal on promoting cell proliferation. Copyright © 2012 John Wiley & Sons, Ltd.
A descriptor of amino acids SVWG and its applications in peptide QSAR
Authors: Tong Jianbo , Chen Yang , Liu Shuling , Che Ting , Xu Xiameng
Published: September 2012

A descriptor, SVWG (principal component scores vector of WHIM (weighted holistic invariant molecular index) descriptors and GETWAY (GEometry, Topology, and Atom‐Weights AssemblY) descriptors), was derived from a principal component analysis of a matrix of two structural variables of coded amino acid. SVWG scales were then applied in three panels of peptide quantitative structure activity relationship (QSAR) that were molded by partial least squares regression. The obtained models with the correlation coefficient () and cross‐validation correlation coefficient () were 0.893 and 0.830 for angiotensin‐converting enzyme inhibitors, 0.990 and 0.968 for antimicrobial peptides, and 0.955 and 0.908 for oxytocin, respectively. Satisfactory results showed that information related to biological activity can be systemically expressed by SVWG scales, which may be a useful structural expression methodology for study on peptide QSAR. Copyright © 2012 John Wiley & Sons, Ltd.
Angular Benzoperylenetetracarboxylic Bisimides
Authors: Langhals Heinz , Böck Bernd , Schmid Tanja , Marchuk Alexey
Published: September 2012

Benzoperylene derivatives with two angularly attached dicarboxylic imide rings, which were prepared by the Diels–Alder‐Reaction, exhibit strong fluorescence and their free peri positions allow either control of the UV/Vis spectra through their substituents or form anchor positions for the attachment of functional units. The angular chromophore 3 may be used both for fluorescent labeling such as for primary amines or enzymes or as building blocks for more complex assemblies where they may act as energy donors for FRET or electron acceptors in PET such as for photovoltaic solar cells.
NMR Spectroscopic Analysis Reveals Extensive Binding Interactions of Complex Xyloglucan Oligosaccharides with the Cellvibrio japonicus Glycoside Hydrolase Family 31 α‐Xylosidase
Authors: Silipo Alba , Larsbrink Johan , Marchetti Roberta , Lanzetta Rosa , Brumer Harry , Molinaro Antonio
Published: September 2012

The study of the interaction of glycoside hydrolases with their substrates is fundamental to diverse applications in medicine, food and feed production, and biomass‐resource utilization. Recent molecular modeling of the α‐xylosidase CjXyl31A from the soil saprophyte Cellvibrio japonicus, together with protein crystallography and enzyme‐kinetic analysis, has suggested that an appended PA14 protein domain, unique among glycoside hydrolase family 31 members, may confer specificity for large oligosaccharide fragments of the ubiquitous plant polysaccharide xyloglucan (J. Larsbrink, A. Izumi, F. M. Ibatullin, A. Nakhai, H. J. Gilbert, G. J. Davies, H. Brumer, Biochem. J. 2011, 436, 567–580). In the present study, a combination of NMR spectroscopic techniques, including saturation transfer difference (STD) and transfer NOE (TR‐NOE) spectroscopy, was used to reveal extensive interactions between CjXyl31A active‐site variants and xyloglucan hexa‐ and heptasaccharides. The data specifically indicate that the enzyme recognizes the entire cello‐tetraosyl backbone of the substrate and product in positive enzyme subsites and makes further significant interactions with internal pendant α‐(1→6)‐linked xylosyl units. As such, the present analysis provides an important rationalization of previous kinetic data on CjXyl31A and unique insight into the role of the PA14 domain, which was not otherwise obtainable by protein crystallography.
Tautomerization in 2,7,12,17‐Tetraphenylporphycene and 9‐Amino‐2,7,12,17‐tetraphenylporphycene: Influence of Asymmetry on the Direction of the Transition Moment
Authors: Fita Piotr , Pszona Maria , Orzanowska Grażyna , Sánchez‐García David , Nonell Santi , Vauthey Eric , Waluk Jacek
Published: September 2012

Femtosecond transient absorption anisotropy studies have been performed for two porphycenes of different symmetry. In 2,7,12,17‐tetraphenylporphycene, the chemical identity of two trans forms implies a change in the S0–S1 transition‐moment direction upon tautomerization. Exploiting this phenomenon, the rates of double hydrogen transfer in both the S0 and S1 states (1.4×1012 s−1 and 2.7×1011 s−1, respectively) have been determined by performing time‐resolved anisotropy studies. In the asymmetric 9‐amino‐2,7,12,17‐tetraphenylporphycene, tautomerization occurs with a similar rate in the ground state. In the S1 state, the reaction is hindered in its vibrationally relaxed form, but the excitation spectra suggest that it may occur for an unrelaxed molecule. Unlike all porphycenes that have been studied so far, 9‐amino‐2,7,12,17‐tetraphenylporphycene does not reveal significant changes in anisotropy owing to intramolecular double hydrogen transfer; rather, the transition‐moment directions are similar in the two tautomeric forms. Analysis of the molecular orbitals allows for an explanation of the “locking” of the transition moments: it is due to a large splitting of the two HOMO orbitals, which retain the order of their energies in the two tautomers.
Reversible Double CH Bond Activation of Linear and Cyclic Ethers To Form Iridium Carbenes
Authors: Valpuesta Jose E. V. , Álvarez Eleuterio , López‐Serrano Joaquín , Maya Celia , Carmona Ernesto
Published: September 2012

The double CH bond activation of a series of linear and cyclic ethers by the iridium complex [Tptol′Ir(C6H5)(N2)] (2⋅N2), which features a cyclometalated hydrotris(3‐p‐tolylpyrazol‐1‐yl)borate ligand (Tptol′) coordinated in a κ4‐N,N′,N′′,C manner, has been studied. Two methyl ethers, namely, Me2O and MeOtBu, along with diethyl ether and the cyclic ethers tetrahydrofuran, tetrahydropyran (THP), and 1,4‐dioxane have been investigated with formation in every case of the corresponding hydride carbene complexes 3–8, which are stabilized by κ4‐coordination of the ancillary Tptol′ ligand. Five of the compounds have been structurally authenticated by X‐ray crystallography. A remarkable feature of these rearrangements is the reversibility of the double CH bond activation of Me2O, MeOtBu, Et2O, and THP. This has permitted catalytic deuterium incorporation into the methyl groups of the two methyl ethers, although in a rather inefficient manner (for synthetic purposes). Although possible in all cases, CC coupling by migratory insertion of the carbene into the IrC σ bond of the metalated linkage has only been observed for complex 8 that contains a cyclic carbene that results from α,α‐CH activation of 1,4‐dioxane. Computational studies on the formation of iridium carbenes are also reported, which show a role for metalated Tp ligands in the double CH activation and account for the reversibility of the reaction in terms of the relative stability of the reagents and the products of the reaction.
Graphite Oxides: Effects of Permanganate and Chlorate Oxidants on the Oxygen Composition
Authors: Chua Chun Kiang , Sofer Zdeněk , Pumera Martin
Published: September 2012

Research on graphene materials has refocused on graphite oxides (GOs) in recent years. The fabrication of GO is commonly accomplished by using concentrated sulfuric acid in conjunction with: a) fuming nitric acid and KClO3 oxidant (Staudenmaier); b) concentrated nitric acid and KClO3 oxidant (Hofmann); c) sodium nitrate for in situ production of nitric acid in the presence of KMnO4 (Hummers); or d) concentrated phosphoric acid with KMnO4 (Tour). These methods have been used interchangeably in the graphene community, since the properties of GOs produced by these different methods were assumed as almost similar. In light of the wide applicability of GOs in nanotechnology applications, in which presence of certain oxygen functional groups are specifically important, the qualities and functionalities of the GOs produced by using these four different methods, side‐by‐side, was investigated. The structural characterizations of the GOs would be probed by using high resolution X‐ray photoelectron spectroscopy, nuclear magnetic resonance, Fourier transform infrared spectroscopy, and Raman spectroscopy. Further electrochemical applicability would be evaluated by using electrochemical impedance spectroscopy and cyclic voltammetry techniques. Our analyses highlighted that the oxidation methods based on permanganate oxidant (Hummers and Tour methods) gave GOs with lower heterogeneous electron‐transfer rates and a higher amount of carbonyl and carboxyl functionalities compared with when using chlorate oxidant (Staudenmaier and Hofmann methods). These observations indicated large disparities between the GOs obtained from different oxidation methods. Such insights would provide fundamental knowledge for fine tuning GO for future applications.
ChemInform Abstract: Effect of the Framework Flexibility on the Centricities in Centrosymmetric In2Zn(SeO3)4 and Noncentrosymmetric Ga2Zn(TeO3)4.
Authors: Lee Dong Woo , Bak Dan‐bee , Kim Saet Byeol , Kim Jiwon , Ok Kang Min
Published: September 2012

Crystals of In2Zn(SeO3)4 (I) and Ga2Zn(TeO3)4 (II) are prepared by solid state reaction of ZnO, In2O3 or Ga2O3, and SeO2 or TeO2 (silica tubes, 600—700 °C, 48 h).
ChemInform Abstract: Crystal Structure and Magnetic Properties of NaCuII [(CuII3O)(PO4)2Cl].
Authors: Jin Teng‐Teng , Liu Wei , Chen Shuang , Prots Yurii , Schnelle Walter , Zhao Jing‐Tai , Kniep Ruediger , Hoffmann Stefan
Published: September 2012

The new title compound is synthesized from a mixture of NH4H2PO4, NaCl, and CuCl2 (alumina crucible, 727 K, 2 d) and characterized by single crystal XRD and magnetic measurements.
ChemInform Abstract: Effect of Structural Packing on the Luminescence Properties in Tungsten Bronze Compounds M2KNb5O15 (M: Ca, Sr, Ba).
Authors: Yin Xin , Shi Liu , Wei Ang , Wan Dongyun , Wang Yaoming , Huang Fuqiang
Published: September 2012

Whereas Ca2KNb5O15 exhibits host luminescence at 460 nm when excited at 269 nm, Sr2KNb5O15 and Ba2KNb5O15 do not show host luminescence.
ChemInform Abstract: Standard Enthalpy of Formation of NaxCoO2 System
Authors: Phapale S. , Mishra R. , Mishra P. K.
Published: September 2012

[solution calorimetric determination for x = 0.1, 0.2, ...
ChemInform Abstract: Freeze‐Drying Synthesis of Li3V2(PO4)3/C Cathode Material for Lithium‐Ion Batteries.
Authors: Qiao Y. Q. , Wang X. L. , Mai Y. J. , Xia X. H. , Zhang J. , Gu C. D. , Tu J. P.
Published: September 2012

The title cathode material is prepared by freeze‐drying of an aqueous solution containing NH4VO3, LiOH, and H3PO4 (‐53 °C, 48 h) followed by calcination of the obtained precursor together with polystyrene spheres as the carbon source (Ar flow, 750 °C, 8 h).
ChemInform Abstract: Effects of Large Halides on the Structures of Lanthanide(III) and Plutonium(III) Borates.
Authors: Polinski Matthew J. , Wang Shuao , Cross Justin N. , Alekseev Evgeny V. , Depmeier Wulf , Albrecht‐Schmitt Thomas E.
Published: September 2012

As revealed by single crystal XRD compounds (III) and (VII) crystallize in the space group P21/n with Z = 4.
ChemInform Abstract: Syntheses, Crystal Structures and Characterizations of New Vanadium Arsenites and Arsenates.
Authors: Liu Jun‐Hui , He Zhang‐Zhen , Kong Fang , Xu Xiang , Sun Chuan‐Fu , Mao Jiang‐Gao
Published: September 2012

The structures of (III), (IV), (VII), and (VIII) are determined by single crystal XRD.
ChemInform Abstract: Synthesis of Mixed‐Valent α‐ and β‐NaFe2O3 Polymorphs under Controlled Partial Oxygen Pressure.
Authors: Bruno Shaun R. , Blakely Colin K. , Poltavets Viktor V.
Published: September 2012

The title polymorphs are synthesized from stoichiometric mixtures of α‐NaFeO2, α‐Fe2O3, and Fe metal under controlled oxygen partial pressure (alumina boats in a closed quartz tube, 850 °C, 48—72 h).
ChemInform Abstract: Visible Light Photoredox Organocatalysis: A Fully Transition Metal‐Free Direct Asymmetric α‐Alkylation of Aldehydes.
Authors: Fidaly Kassim , Ceballos Claire , Falguieres Annie , Veitia Maite Sylla‐Iyarreta , Guy Alain , Ferroud Clotilde
Published: September 2012

A combination of photoredox catalyst with chiral imidazolidinone organocatalyst is used for the asymmetric α‐alkylation of aldehydes (II) with bromide (I).
ChemInform Abstract: Cine Substitution of Arenes Using the Aryl Carbamate as a Removable Directing Group.
Authors: Mesganaw Tehetena , Nathel Noah F. Fine , Garg Neil K.
Published: September 2012

Arylcarbamates undergo cine‐substitution reactions via ortho‐metallation and functionalization to afford ortho‐substituted products.
ChemInform Abstract: Bi(OTf)3‐Catalyzed Cycloisomerization of Aryl‐Allenes.
Authors: Lemiere Gilles , Cacciuttolo Bastien , Belhassen Emilie , Duncah Elisabet
Published: September 2012

Cyclohydroarylation or tandem intramolecular cycloaddition reactions produce different types of polycycles.
ChemInform Abstract: Gold(I)‐Catalyzed Regioselective Inter‐/Intramolecular Addition Cascade of Di‐ and Triynes for Direct Construction of Substituted Naphthalenes.
Authors: Naoe Saori , Suzuki Yamato , Hirano Kimio , Inaba Yusuke , Oishi Shinya , Fujii Nobutaka , Ohno Hiroaki
Published: September 2012

The method provides a new approach to 1,3‐disubstituted naphthalenes, disubstituted chrysenes, and related compounds.
ChemInform Abstract: An Excellent Dual Recycling Strategy for the Hypervalent Iodine/Nitroxyl Radical Mediated Selective Oxidation of Alcohols to Aldehydes and Ketones.
Authors: Dohi Toshifumi , Fukushima Kei‐ichiro , Kamitanaka Tohru , Morimoto Koji , Takenaga Naoko , Kita Yasuyuki
Published: September 2012

An adamantane‐derived hypervalent iodine reagent is an efficient oxidant for the conversion of primary and secondary alcohols.
ChemInform Abstract: Terminal Alkyne Homocoupling Reactions Catalyzed by an Efficient and Recyclable Polymer‐Supported Copper Catalyst at Room Temperature under Solvent‐Free Conditions.
Authors: He Ying , Cai Chun
Published: September 2012

Both aromatic and aliphatic terminal alkynes undergo the homocoupling reaction within only 10‐20 minutes to give the corresponding 1,4‐disubstituted 1,3‐diynes in excellent to high yields.
ChemInform Abstract: Thiopseudourea Ligated Palladium Complexes: Synthesis, Characterization and Application as Catalysts for Suzuki—Miyaura, Sonogashira, Heck and Hiyama Reactions.
Authors: Srinivas Keesara , Srinivas Pottabathula , Prathima Parvathaneni Sai , Balaswamy Kodicherla , Sridhar Balsubramanian , Rao Mandapati Mohan
Published: September 2012

Six palladium complexes of type (I) are prepared in 4 steps from commercially available benzoyl chlorides.
ChemInform Abstract: Dehydrogenative Amide Synthesis from Alcohol and Amine Catalyzed by Hydrotalcite‐Supported Gold Nanoparticles.
Authors: Zhu Jiangling , Zhang Yan , Shi Feng , Deng Youquan
Published: September 2012

With exception of benzyl amine (IIa), only cyclic amines are found to be efficient substrates in the amidation process.
ChemInform Abstract: Highly Atom Economical Uncatalyzed and I2‐Catalyzed Silylation of Phenols, Alcohols and Carbohydrates, Using HMDS under Solvent‐Free Reaction Conditions (SFRC).
Authors: Jereb Marjan
Published: September 2012

The environmentally friendly method is performed strictly without a solvent, in the presence of air, and using a small excess of Tms2NH to give the crude products with high purity.
ChemInform Abstract: Synthesis of Amines from Alcohols in a Nonepimerizing One‐Pot Sequence — Synthesis of Bioactive Compounds: Cinacalcet and Dexoxadrol.
Authors: Guerin Claire , Bellosta Veronique , Guillamot Gerard , Cossy Janine
Published: September 2012

The present method proceeds without epimerization of enantioenriched amines or alcohols.
ChemInform Abstract: Preparation of Modified Peptides: Direct Conversion of α‐Amino Acids into β‐Amino Aldehydes.
Authors: Saavedra Carlos J. , Boto Alicia , Hernandez Rosendo
Published: September 2012

The present method is applied to preparation of small peptide derivatives with β‐aldehyde moieties which in turn are precursors of peptides possessing a γ‐alcohol unit.
ChemInform Abstract: Enantioselective Diels—Alder Reaction of α‐(Acylthio)acroleins: A New Entry to Sulfur‐Containing Chiral Quaternary Carbons.
Authors: Sakakura Akira , Yamada Hiroki , Ishihara Kazuaki
Published: September 2012

Unfortunately, coupling of the acrolein (Ie) with cyclopentadiene gives racemic products.
ChemInform Abstract: Nickel‐Catalyzed Regio‐ and Stereoselective Reductive Coupling Between Methylenecyclopropanes, Aldehydes, and Triethylborane with Retention of the Cyclopropane Ring.
Authors: Ogata Kenichi , Shimada Daisuke , Fukuzawa Shin‐ichi
Published: September 2012

The title reaction generates cyclopropane derivatives with a quaternary stereocenter in a stereoselective manner.
ChemInform Abstract: Tandem Nucleophilic Addition/Fragmentation of Vinylogous Acyl Nonaflates for the Synthesis of Functionalized Alkynes, with New Mechanistic Insight.
Authors: Batsomboon Paratchata , Gold Brian A. , Alabugin Igor V. , Dudley Gregory B.
Published: September 2012

The utility of nonaflates (III) in title reactions to provide alkyne‐tethered ketones and β‐ketophosphonates is demonstrated.
ChemInform Abstract: Magnetically Separable Cu‐Carboxylate MOF Catalyst for the Henry Reaction.
Authors: Arai Takayoshi , Kawasaki Nao , Kanoh Hirofumi
Published: September 2012

The metal‐organic framework is synthesized and successfully employed as catalyst in the cross‐coupling reaction of phenylacetylene with 2‐oxazolidinone.
ChemInform Abstract: Direct Reductive Amination of Aldehydes Using Lithium—Arene (cat.) as Reducing System: A Simple One‐Pot Procedure for the Synthesis of Secondary Amines.
Authors: Nador Fabiana , Moglie Yanina , Ciolino Andres , Pierini Adriana , Dorn Viviana , Yus Miguel , Alonso Francisco , Radivoy Gabriel
Published: September 2012

Main products are the expected secondary amines or analogous imines for substrates having electron‐withdrawing groups.
ChemInform Abstract: Asymmetric Aldol Reaction Catalyzed by the Anion of an Ionic Liquid.
Authors: Gauchot Vincent , Schmitzer Andreea R.
Published: September 2012

Salts (I) promote the reaction of some cyclic and acyclic ketones with aromatic aldehydes.
ChemInform Abstract: Asymmetric Transfer Hydrogenation of Ketones Catalyzed by Nickel Complex with New PNO‐Type Ligands.
Authors: Dong Zhen Rong , Li Yan Yun , Yu Shen Luan , Sun Guo Song , Gao Jing Xing
Published: September 2012

Moderate to good enantioselectivities can be obtained for aromatic ketone substrates.
ChemInform Abstract: Graphene Oxide as an Acid Catalyst for the Room Temperature Ring Opening of Epoxides.
Authors: Dhakshinamoorthy Amarajothi , Alvaro Mercedes , Concepcion Patricia , Fornes Vicente , Garcia Hermenegildo
Published: September 2012

A simple and general procedure for the title reaction is developed by using a highly efficient and easily recoverable and reusable catalyst for additional runs before deactivation.
ChemInform Abstract: Direct C—H Arylation of Quinones with Anilines.
Authors: Lamblin Marc , Naturale Guillaume , Dessolin Jean , Felpin Francois‐Xavier
Published: September 2012

The coupling step proceeds under mild, metal‐free aqueous conditions.
ChemInform Abstract: Preparation of Chiral 3‐Arylpyrrolidines via the Enantioselective 1,4‐Addition of Arylboronic Acids to Fumaric Esters Catalyzed by Rh(I)/Chiral Diene Complexes.
Authors: Chung Yu‐Chiang , Janmanchi Damodar , Wu Hsyueh‐Liang
Published: September 2012

A wide range of arylboronic acids is subjected to the reaction with diester (I).
ChemInform Abstract: SN1‐Type Substitution Reactions of N‐Protected β‐Hydroxytyrosine Esters: Stereoselective Synthesis of β‐Aryl and β‐Alkyltyrosines.
Authors: Wilcke David , Herdtweck Eberhardt , Bach Thorsten
Published: September 2012

Stereochemistry of desired aryl‐and β‐alkyltyrosines is strongly influenced by the choice of protecting and ester groups of starting hydroxytyrosine esters.
ChemInform Abstract: Highly Enantio‐ and Diastereoselective Vinylogous Aldol Reaction by LiCl‐Assisted BINOL—Titanium Species.
Authors: Wang Guowei , Wang Baomin , Qi Shuai , Zhao Jinfeng , Zhou Yuhan , Qu Jingping
Published: September 2012

The reaction is applied to a wide range of aromatic, olefinic and aliphatic aldehydes to prepare the target products in high yields and nearly complete enantioselectivities.
ChemInform Abstract: Catalytic Activation of Diazo Compounds Using Electron‐Rich, Defined Iron Complexes for Carbene‐Transfer Reactions.
Authors: Holzwarth Michael S. , Alt Isabel , Plietker Bernd
Published: September 2012

Various diazo compounds are used and the transformation displays a broad functional group tolerance.
ChemInform Abstract: Supported Au Nanoparticles as Efficient Catalysts for Aerobic Homocoupling of Phenylboronic Acid.
Authors: Wang Liang , Zhang Wei , Su Dang Sheng , Meng Xiangju , Xiao Feng‐Shou
Published: September 2012

A highly active and easily recyclable catalyst is prepared for the title synthesis.
ChemInform Abstract: Organocatalytic Asymmetric Synthesis of Trifluoromethyl‐Substituted Diarylpyrrolines: Enantioselective Conjugate Cyanation of β‐Aryl‐β‐trifluoromethyl‐disubstituted Enones.
Authors: Kawai Hiroyuki , Okusu Satoshi , Tokunaga Etsuko , Sato Hiroyasu , Shiro Motoo , Shibata Norio
Published: September 2012

The simple title synthesis is reported for the first time.
ChemInform Abstract: An Active and Selective Heterogeneous Catalytic System for Michael Addition.
Authors: Keipour Hoda , Khalilzadeh Mohammad A. , Hosseini Abolfazl , Pilevar Afsaneh , Zareyee Daryoush
Published: September 2012

It is demonstrated that the exceedingly strong base KF on clinoptilotite is highly efficient for the selective 1,4‐Michael addition of different donors to chalcones to give the adducts in excellent yields.
ChemInform Abstract: Synthesis of 1,1‐Diarylethylenes via Efficient Iron/Copper Co‐Catalyzed Coupling of 1‐Arylvinyl Halides with Grignard Reagents.
Authors: Hamze Abdallah , Brion Jean‐Daniel , Alami Mouad
Published: September 2012

A wide range of biologically valuable title compounds is prepared.
ChemInform Abstract: Feeding the Heck Reaction with Alcohol: One‐Pot Synthesis of Stilbenes from Aryl Alcohols and Bromides.
Authors: Colbon Paul , Barnard Jonathan H. , Purdie Mark , Mulholland Keith , Kozhevnikov Ivan , Xiao Jianliang
Published: September 2012

The reaction proceeds via selective dehydration of alcohols to styrenes followed by a Pd‐catalyzed Heck arylation to afford a variety of functionalized stilbenes in one‐pot manner.
ChemInform Abstract: Tandem Decarboxylative Allylation and Fragmentation of Allyl Benzocyclobutenyl Carbonates: Access to ortho‐Functionalized Aryls from Aryl Bromides.
Authors: Rosa David , Chtchemelinine Andrei , Orellana Arturo
Published: September 2012

Benzocyclobutenols (IV) and (VI) undergo Pd‐catalyzed decarboxylative allylation and selective β‐elimination leading to ortho‐substituted arenes (V) and (VII), generally in good yields.