bluuebunny/crossref_metadata_2025 huggingface dataset:
The Orientation of Map Boards
Authors: Nightingale John
Published: October 2009

Many events take place in venues that are unfamiliar to visitors attending the events. These customers need to be able to find their way around the site and the locality. They can do this using a variety of techniques, including navigation using fixed maps mounted on boards provided
by the venue or the city. The key recommendation is that normal signs, where North is at the top of the map, and the board should be facing South. In event venues such as sports grounds and exhibition halls, it is less important for the top of the map to indicate North. It might be possible
to turn the image to a "you-are here" board so that the orientation matches the grounds. Finding your way at events is important to customer satisfaction. Maps sometimes are the least addressed planning issue, but should be considered by all sizes and types of events.
Carmichael Numbers with a Square Totient
Authors: Banks W. D.
Published: October 2009

Let φ denote the Euler function. In this paper, we show that for all large x there are more than x0.33 Carmichael numbers n ⩽ x with the property that φ(n) is a perfect square. We also obtain similar results for higher powers.
Huber's Theorem for Hyperbolic Orbisurfaces
Authors: Dryden Emily B. , Strohmaier Alexander
Published: October 2009

We show that for compact orientable hyperbolic orbisurfaces, the Laplace spectrum determines the length spectrum as well as the number of singular points of a given order. The converse also holds, giving a full generalization of Huber's theorem to the setting of compact orientable hyperbolic orbisurfaces.
On Projection Bodies of Order One
Authors: Campi Stefano , Gronchi Paolo
Published: October 2009

The projection body of order one Π1K of a convex body K in ℝn is the body whose support function is, up to a constant, the average mean width of the orthogonal projections of K onto hyperplanes through the origin.

The paper contains an inequality for the support function of Π1K, which implies in particular that such a function is strictly convex, unless K has dimension one or two. Furthermore, an existence problem related to the reconstruction of a convex body is discussed to highlight the different behavior of the area measures of order one and of order n – 1.
A Class of Cellulated Spheres with Non-Polytopal Symmetries
Authors: Gévay Gábor
Published: October 2009

We construct, for alld≥ 4, a cellulation of. We prove that these cellulations cannot be polytopal with maximal combinatorial symmetry. Such non-realizability phenomenon was first described in dimension 4 by Bokowski, Ewald and Kleinschmidt, and, to the knowledge of the author, until now there have not been any known examples in higher dimensions. As a starting point for the construction, we introduce a new class of (Wythoffian) uniform polytopes, which we call duplexes. In proving our main result, we use some tools that we developed earlier while studying perfect polytopes. In particular, we prove perfectness of the duplexes; furthermore, we prove and make use of the perfectness of another new class of polytopes which we obtain by a variant of the so-calledE-construction introduced by Eppstein, Kuperberg and Ziegler.
A One-Dimensional Family of K3 Surfaces with a ℤ4 Action
Authors: Artebani Michela
Published: October 2009

The minimal resolution of the degree four cyclic cover of the plane branched along a GIT stable quartic is a K3 surface with a non symplectic action of ℤ4. In this paper we study the geometry of the one-dimensional family of K3 surfaces associated to the locus of plane quartics with five nodes.
The Irreducibility of Polynomials That Have One Large Coefficient and Take a Prime Value
Authors: Bonciocat Anca Iuliana , Bonciocat Nicolae Ciprian
Published: October 2009

We use some classical estimates for polynomial roots to provide several irreducibility criteria for polynomials with integer coefficients that have one sufficiently large coefficient and take a prime value.
Palladium‐Catalyzed Annulation of 2‐(1‐Alkynyl)benzenamines with Disulfides: Synthesis of 3‐Sulfenylindoles
Authors: Guo Yan‐Jin , Tang Ri‐Yuan , Li Jin‐Heng , Zhong Ping , Zhang Xing‐Guo
Published: October 2009

3‐Sulfenylindoles can be efficiently prepared in moderate to good yields from 2‐(1‐alkynyl)benzenamines and disulfides using the palladium/air catalytic systems. The study also provides a useful route to the synthesis of fipronil analogues.
Silver‐Catalyzed Intramolecular Cyclization of o‐(1‐Alkynyl)benzamides: Efficient Synthesis of (1H)‐Isochromen‐1‐imines
Authors: Liu Guannan , Zhou Yu , Ye Deju , Zhang Dengyou , Ding Xiao , Jiang Hualiang , Liu Hong
Published: October 2009

An efficient avenue for the facile and atom‐economic synthesis of (1H)‐isochromen‐1‐imines has been developed, and a broad spectrum of substrates can participate in the process effectively to produce the desired products in good yields. Significantly, this is the first report of the synthesis of (1H)‐isochromen‐1‐imines that involves a silver(I)‐catalyzed, regiocontrolled intramolecular addition of the carbonyl group of the amide moiety towards an alkyne.
Room Temperature Lewis Base‐Catalyzed Alumination of Terminal Alkynes
Authors: Zhou Yuhan , Lecourt Thomas , Micouin Laurent
Published: October 2009

An efficient and mild access to mixed dimethylalkynylaluminum reagents has been developed via a direct Lewis base‐catalyzed alumination of terminal alkynes by trimethylaluminum. The use of bis(trimethylsilyl)methylamine enables the metalation at room temperature with only 1% of catalyst loading.
An Organocatalytic Synthesis of cis‐N‐Alkyl‐ and N‐Arylaziridine Carboxylates
Authors: Bew Sean P. , Carrington Rachel , Hughes David L. , Liddle John , Pesce Paolo
Published: October 2009

An extremely mild protocol that employs readily available starting materials, i.e., aldehyde, amine and alkyl diazoacetate, returns structurally diverse N‐substituted‐C‐2/3‐difunctionalised aziridines in excellent yields and stereoselectivities when pyridinium triflate is incorporated as an organocatalyst. The reaction process is environmentally benign affording water and nitrogen as the only by‐products. This racemic protocol paves the way for the development of novel asymmetric organocatalysts capable of generating optically active aziridines.
Polyhedral oligomeric silsesquioxane‐bound iminofullerene
Authors: Clarke David J. , Matisons Janis G. , Simon George P. , Samoc Marek , Samoc Anna
Published: October 2009

Polyhedral oligomeric silsesquioxane (POSS) cages containing an iminofullerene species are reported herein. Monosubstituted benzyl chloride POSS was synthesized, and subsequently reacted with sodium azide to form mono benzyl azide POSS. The azide was subsequently reacted with C60 in anhydrous, degassed toluene to yield the desired POSS iminofullerene compound. The prepared compounds were characterized by multinuclear NMR, electrospray mass spectrometry, elemental analysis, UV–vis, fluorescence and optical power limiting measurements. Copyright © 2009 John Wiley & Sons, Ltd.
Decomposition of nitrous oxide over a low‐cost catalyst
Authors: Yang Xinfang , Zhuo Yuqun , Li Tianjin , Chen Changhe , Xu Xuchang
Published: October 2009

Nitrous oxide (N2O) is a significant greenhouse gas and its emissions from fluidized bed combustion systems can be controlled using catalytic conversion and decomposition. The catalytic decomposition of N2O was studied in a quartz fixed‐bed reactor at 450–700 °C. The low‐cost catalyst was prepared from fly ash and iron oxides, and was characterized in terms of the BET specific surface area and XRD. This study showed that both the Fe content on the catalyst surface and the calcination temperature during the preparation of the catalyst should be optimized in order to significantly improve the catalyst performance when used for N2O decomposition. The influences of O2, H2O, CO2 and SO2 on the N2O decomposition were investigated at the most reactive temperature. Experimental results showed that O2 had a small negative effect on the catalytic activity, while CO2 had no obvious effect on the N2O decomposition. The N2O conversion was still high even when H2O was present. However, the N2O conversion dropped sharply when H2O and O2 were both present. The catalytic activity was reduced by SO2 because of its reaction with the catalyst. The difference between the N2O conversion with H2O present and with both H2O and O2 present was analyzed in order to determine the N2O decomposition mechanism. Two mechanisms for the N2O catalytic decomposition mechanism have been considered, of which the one with formation of oxygen atoms at two sites with migration and recombination shows better agreement with our experimental results. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Early steps in plastid evolution: current ideas and controversies
Authors: Bodył Andrzej , Mackiewicz Paweł , Stiller John W.
Published: October 2009

Some nuclear‐encoded proteins are imported into higher plant plastids via the endomembrane (EM) system. Compared with multi‐protein Toc and Tic translocons required for most plastid protein import, the relatively uncomplicated nature of EM trafficking led to suggestions that it was the original transport mechanism for nuclear‐encoded endosymbiont proteins, and critical for the early stages of plastid evolution. Its apparent simplicity disappears, however, when EM transport is considered in light of selective constraints likely encountered during the conversion of stable endosymbionts into fully integrated organelles. From this perspective it is more parsimonious to presume the early evolution of post‐translational protein import via simpler, ancestral forms of modern Toc and Tic plastid translocons, with EM trafficking arising later to accommodate glycosylation and/or protein targeting to multiple cellular locations. This hypothesis is supported by both empirical and comparative data, and is consistent with the relative paucity of EM‐based transport to modern primary plastids.
Flower symmetry evolution: towards understanding the abominable mystery of angiosperm radiation
Authors: Busch Andrea , Zachgo Sabine
Published: October 2009

Flower symmetry is considered a morphological novelty that contributed significantly to the rapid radiation of the angiosperms, which already puzzled Charles Darwin and prompted him to name this phenomenon an ‘abominable mystery’. In 2009, the bicentenary of Darwin's birth and the 150th anniversary of the publication of his seminal work, ‘On the Origin of Species’, this question can now be more satisfactorily readdressed. Understanding the molecular control of monosymmetry formation in the model species Antirrhinum opened the path for comparative studies with non‐model species revealing modifications of this trait. TCP transcription factors, named after TEOSINTE BRANCHED 1 in maize, CYCLOIDEA in snapdragon and PCF in rice, control flower monosymmetry development and contributed to establishing this trait several times independently in higher angiosperms. The joint advances in evolutionary and developmental plant research, combined in the novel research field named Evo/Devo, aim at elucidating the molecular mechanisms and strategies to unravel the mystery of how this diversity has been generated.
Quantum‐dots‐based fluoroimmunoassay for the rapid and sensitive detection of avian influenza virus subtype H5N1
Authors: Chen Liping , Sheng Zonghai , Zhang Anding , Guo Xuebo , Li Jiakui , Han Heyou , Jin Meilin
Published: October 2009

The continuous spread of highly pathogenic avian influenza virus (AIV) subtype H5N1 is threatening the poultry industry and human health worldwide. Rapid and sensitive diagnostic methods are required for the H5N1 surveillance. In this study, the fluorescent (FL) probe of CdTe quantum dots (QDs) was designed using covalently linked rabbit anti‐AIV H5N1 antibody. Based on these QD–antibody conjugates, a novel sandwich FL‐linked immunosorbent assay (sFLISA) was developed for H5N1 viral antigen detection. The sFLISA allowed for H5N1 viral antigen determination in a linear range of 8.0 × 10−3 to 5.1 × 10−1 μg mL−1 with the limit of detection (LOD) of 1.5 × 10−4 μg mL−1. In comparison with virus isolation for 103 clinic samples, the sensitivity and specificity of sFLISA were found to be 93.6 and 91.1% respectively. The sFLISA supplied a novel approach to rapid and sensitive detection of AIV subtype H5N1 and showed great potential for biological applications in immunoassays. Copyright © 2009 John Wiley & Sons, Ltd.
Photo‐mechanical effect in luminescent polymeric materials
Authors: Karpenko A. A. , Fedorenko E. V. , Mirochnik A. G.
Published: October 2009

The photomechanical effect was found for the first time in a polymer composition on the basis of polymethylmethacrylate with embedded molecules of the luminophor dibenzoylmethanate of boron difluoride incapable of undergoing photochemical isomerization, unlike other compounds. A thermal mechanism of photochemical displacement was suggested. Copyright © 2009 John Wiley & Sons, Ltd.
Regioselective hydroxylation of daidzein using P450 (CYP105D7) from Streptomyces avermitilis MA4680
Authors: Pandey Bishnu Prasad , Roh Changhyun , Choi Kwon‐Young , Lee Nahum , Kim Eun Jung , Ko Sungghi , Kim Taejin , Yun Hyundon , Kim Byung‐Gee
Published: October 2009

Regiospecific 3′‐hydroxylation reaction of daidzein was performed with CYP105D7 from Streptomyces avermitilis MA4680 expressed in Escherichia coli. The apparent Km and kcat values of CYP105D7 for daidzein were 21.83 ± 6.3 µM and 15.01 ± 0.6 min−1 in the presence of 1 µM of CYP105D7, putidaredoxin (CamB) and putidaredoxin reductase (CamA), respectively. When CYP105D7 was expressed in S. avermitilis MA4680, its cytochrome P450 activity was confirmed by the CO‐difference spectra at 450 nm using the whole cell extract. When the whole‐cell reaction for the 3′‐hydroxylation reaction of daidzein was carried out with 100 µM of daidzein in 100 mM of phosphate buffer (pH 7.5), the recombinant S. avermitilis grown in R2YE media overexpressing CYP105D7 and ferredoxin FdxH (SAV7470) showed a 3.6‐fold higher conversion yield (24%) than the corresponding wild type cell (6.7%). In a 7 L (working volume 3 L) jar fermentor, the recombinants S. avermitilis grown in R2YE media produced 112.5 mg of 7,3′,4′‐trihydroxyisoflavone (i.e., 29.5% conversion yield) from 381 mg of daidzein in 15 h. Biotechnol. Bioeng. 2010. 105: 697–704. © 2009 Wiley Periodicals.
Coaxial electrohydrodynamic spraying of plasmid DNA/polyethylenimine (PEI) polyplexes for enhanced nonviral gene delivery
Authors: Wu Yun , Fei Zhengzheng , Lee L. James , Wyslouzil Barbara E.
Published: October 2009

DNA/polyethylenimine (PEI) polyplexes are an important class of nonviral vectors. Although the conventional preparation method, bulk mixing, is straightforward, the formation of the DNA/PEI polyplexes is not well controlled. This work explores coaxial electrohydrodynamic spraying (EHDS) as a novel, alternative method to produce DNA/PEI polyplexes in a more controlled manner. Both pGFP/PEI and pSEAP/PEI polyplexes were produced by EHDS with a coaxial needle setup. The size of the polyplexes was determined using dynamic light scattering, and their ability to transfect NIH 3T3 cells was observed by using an inverted fluorescence microscope (pGFP) or quantified by measuring the activity level of alkaline phosphatase (pSEAP). At nitrogen to phosphate ratio (N/P) of 6.7, the polyplexes produced by coaxial EHDS had delivery efficiencies up to 2.6 times higher than those produced by bulk mixing. The N/P ratio and the structure of the EHDS used to make the polyplexes were crucial factors in determining the delivery efficiency. Biotechnol. Bioeng. 2010. 105: 834–841. © 2009 Wiley Periodicals, Inc.
Characterization of a biofilm membrane reactor and its prospects for fine chemical synthesis
Authors: Gross Rainer , Lang Karsten , Bühler Katja , Schmid Andreas
Published: October 2009

Biofilms are known to be robust biocatalysts. Conventionally, they have been mainly applied for wastewater treatment, however recent reports about their employment for chemical synthesis are increasingly attracting attention. Engineered Pseudomonas sp. strain VLB120ΔC biofilm growing in a tubular membrane reactor was utilized for the continuous production of (S)‐styrene oxide. A biofilm specific morphotype appeared in the effluent during cultivation, accounting for 60–80% of the total biofilm irrespective of inoculation conditions but with similar specific activities as the original morphotype. Mass transfer of the substrate styrene and the product styrene oxide was found to be dependent on the flow rate but was not limiting the epoxidation rate. Oxygen was identified as one of the main parameters influencing the biotransformation rate. Productivity was linearly dependent on the specific membrane area and on the tube wall thickness. On average volumetric productivities of 24 g L day−1 with a maximum of 70 g L day−1 and biomass concentrations of 45 gBDW L have been achieved over long continuous process periods (≥50 days) without reactor downtimes. Biotechnol. Bioeng. 2010. 105: 705–717. © 2009 Wiley Periodicals, Inc.
Incidence of and potential risk factors for gallstone disease in a general population sample
Authors: Halldestam I , Kullman E , Borch K
Published: October 2009

Background

Several epidemiological studies have been published, but there are few reports on relations between gallstone incidence, symptomatology and risk factors.

Methods

Of 621 randomly selected individuals aged 35–85 years in a general population who had been screened previously with ultrasonography and found to have no gallbladder stones, 503 (81·0 per cent) were re-examined after a minimum interval of 5 years. At baseline and re-examination, heredity for gallstone disease was explored and body mass index, digestive symptoms including abdominal pain, quality of life, alcohol and smoking habits, use of non-steroidal anti-inflammatory drugs and oestrogen, parity and blood lipid levels were recorded.

Results

Forty-two (8·3 per cent) of the 503 subjects developed stones. Subjects were followed for a total of 3025·8 person-years, yielding an incidence for newly developed gallstones of 1·39 per 100 person-years. A positive association for gallstone development was found only for length of follow-up and plasma low-density lipoprotein-cholesterol levels at baseline. Weekly alcohol consumption was inversely related to gallstone development.

Conclusion

The incidence of gallstones in this population was 1·39 per 100 person-years. Gallstone development was related to length of follow-up and LDL-cholesterol levels, and inversely related to alcohol consumption.
Abdominosacral resection for locally advanced and recurrent rectal cancer
Authors: Ferenschild F T J , Vermaas M , Verhoef C , Dwarkasing R S , Eggermont A M M , de Wilt J H W
Published: October 2009

Background

The results of resection of locally advanced and recurrent rectal cancers, including sacral resection, were analysed critically.

Methods

Between 1987 and 2007, 353 patients with locally advanced or recurrent rectal cancer, all treated in a tertiary referral centre, were identified from a prospective database. Twenty-five patients (eight primary and 17 recurrent tumours) underwent en bloc sacral resection.

Results

A mid-sacral resection was carried out in 12 patients (level S3) and a low sacral resection in 13 (level S4/S5). Nineteen patients had an R0, four an R1 and two an R2 resection. There was no postoperative mortality. Median follow-up was 32 months. Incomplete resection had an independent negative influence on local control (5-year local recurrence rate 42 versus 0 per cent in those with and without incomplete resection; P < 0·001). The 5-year overall survival rate was 30 per cent. Five patients with recurrent tumour had pathological invasion into the sacral bone and none survived beyond 1 year.

Conclusion

Abdominosacral resection can be performed in patients with locally advanced and recurrent rectal cancer. Patients who cannot undergo a complete resection or have clear evidence of cortical invasion have a poor prognosis.
Non-viral Smad7 gene delivery and attenuation of postoperative peritoneal adhesion in an experimental model
Authors: Guo H , Leung J C K , Cheung J S , Chan L Y Y , Wu E X , Lai K N
Published: October 2009

Background

Postoperative intra-abdominal adhesion is associated with high morbidity and mortality. Smad7, a protein that occupies a strategic position in fibrogenesis, inhibits the transforming growth factor (TGF) β/Smad signalling pathway. In this study the therapeutic potential of exogenous Smad7 in preventing fibrogenesis in postoperative intra-abdominal adhesion was investigated.

Methods

Intra-abdominal adhesion was induced in a rodent model by peritoneal abrasion. Smad7 was delivered into the peritoneal cavity by a non-viral ultrasound–microbubble-mediated naked gene transfection system. The effect of Smad7 transgene on adhesion formation was studied by measuring changes in TGF-β, fibrogenic factors, α-SMA and Smad2/3 activation in the anterior abdominal wall.

Results

Four weeks after surgical abrasion, all rats developed significant peritoneal adhesion with enhanced TGF-β expression, increased levels of extracellular matrix components and activated myofibroblasts, accompanied by decreased Smad7 expression and increased Smad2/3 activation. In rats treated with the Smad7 transgene, the incidence and severity of peritoneal adhesion were significantly reduced, with biochemical downregulation of fibrogenic factors and inhibition of Smad2/3 activation. Serial quantitation using magnetic resonance imaging revealed a significant reduction in adhesion areas from day 14 onwards.

Conclusion

Ultrasound–microbubble-mediated gene transfection provides timely targeted gene delivery for the treatment of postoperative peritoneal adhesions.
Long-term weight change after oesophageal cancer surgery
Authors: Martin L , Lagergren P
Published: October 2009

Background

Malnutrition is common after oesophageal cancer surgery. This study investigated weight changes and the risk of malnutrition among long-term survivors.

Methods

A nationwide cohort study was conducted in Sweden in 2001–2004, with follow-up to 2008. Weight was assessed before oesophagectomy, after 6 months and at 3 years. Logistic regression was performed with adjustment for confounders. Odds ratios (ORs) for postoperative weight loss of at least 15 per cent were estimated.

Results

Some 203 patients survived at least 3 years after oesophagectomy. Continuous weight loss occurred for up to 3 years. Women and men had a similar risk of malnutrition after 3 years (OR 0·85 (95 per cent confidence interval 0·24 to 2·98)). In overweight patients (preoperative body mass index at least 25 kg/m2) the risk of malnutrition was increased almost fivefold at 6 months (OR 4·90 (2·27 to 10·59)) and 3 years (OR 4·60 (1·80 to 11·78)). There was no difference in weight loss at 6 months between survivors and those who died between 6 months and 3 years after surgery (OR 1·11 (0·64 to 1·94)).

Conclusion

Weight loss can be long lasting after oesophagectomy; overweight patients are at particularly increased risk of malnutrition.
Randomized clinical trial of the effect of glucocorticoids on peritoneal inflammation and postoperative recovery after colectomy
Authors: Zargar-Shoshtari K , Sammour T , Kahokehr A , Connolly A B , Hill A G
Published: October 2009

Background

Recent data have suggested a relationship between postoperative fatigue and the peritoneal cytokine response after surgery. The aim of this study was to test the hypothesis that preoperative administration of glucocorticoids before surgery would decrease fatigue and enhance recovery, by reducing the peritoneal production of cytokines.

Methods

In a double-blind randomized controlled study, patients undergoing elective, open colonic resection were administered 8 mg dexamethasone or normal saline. Patients were treated within an enhanced recovery after surgery programme. Primary outcomes were cytokine levels in peritoneal drain fluid and fatigue as measured by the Identity–Consequence Fatigue Scale (ICFS).

Results

Baseline parameters were similar for 29 patients in the dexamethasone group and 31 in the placebo group. Patients who received dexamethasone had lower ICFS scores on days 3 and 7. Dexamethasone was associated with significantly lower peritoneal fluid interleukin (IL) 6 and IL-13 concentrations on day 1, and these correlated with changes in the ICFS score. There was no significant increase in adverse events in the dexamethasone group.

Conclusion

Preoperative administration of dexamethasone resulted in a significant reduction in early postoperative fatigue, associated with an attenuated early peritoneal cytokine response. Peritoneal production of cytokines may therefore be important in postoperative recovery. Registration number: ACTRN12607000066482 (http://www.anzctr.org.au/).
Leucocyte depletion of perioperative blood transfusion does not affect long-term survival and recurrence in patients with gastrointestinal cancer (Br J Surg 2009; 96: 734–740)
Authors: Nash G
Published: October 2009

The Editors welcome topical correspondence from readers relating to articles published in the Journal. Responses should be sent electronically via the BJS website (www.bjs.co.uk). All letters will be reviewed and, if approved, appear on the website. A selection of these will be edited and published in the Journal. Letters must be no more than 250 words in length.
Increased Enantioselectivity by Engineering Bottleneck Mutants in an Esterase from Pseudomonas fluorescens
Authors: Schließmann Anna , Hidalgo Aurelio , Berenguer José , Bornscheuer Uwe T.
Published: October 2009

Four hydrophobic and bulky amino acid residues (F126, F144, F159, and I225) were identified to form a bottleneck guarding the entrance to the active site of an esterase from Pseudomonas fluorescens (PFE I). Hence, a range of nonpolar amino acids were introduced into PFE I to broaden the substrate range and to increase enantioselectivity while preserving the hydrophobicity of the tunnel. First, single variants were created and then the most enantioselective ones were combined to find cooperative effects. This resulted in several mutants, which showed substantially enhanced enantioselectivity; for instance, in the kinetic resolution of 1‐phenyl‐1‐propyl acetate, with which the wild type only showed E=1.2, two mutants gave E>46. For 1‐phenyl‐1‐ethyl acetate enantioselectivity increased from ∼50 to >100 for all mutants studied. Furthermore, higher conversions could be found at shorter reaction times; this indicates that the mutations not only enhanced selectivity, but that also the entrance into the active site was indeed facilitated by these mutations. The experimental results could be explained by computer modeling.
Auto‐Tandem Catalysis: A Single Catalyst Activating Mechanistically Distinct Reactions in a Single Reactor
Authors: Shindoh Naoya , Takemoto Yoshiji , Takasu Kiyosei
Published: October 2009

Domino reactions have received great attention as efficient synthetic methodologies for the construction of structurally complex molecules from simple materials in a single operation. Catalysts in domino reactions have also been well studied. In these reactions, a catalyst activates the substrate(s) only once, and the structure of the product is delineated at that time. Recently, the new concept of “tandem catalysis” in domino reactions, in which catalyst(s) sequentially activate more than two mechanistically distinct reactions, has been proposed. Tandem catalysis is categorized into three subclasses: orthogonal‐, auto‐, and assisted‐tandem catalyses. Auto‐tandem catalysis is defined as a process in which one catalyst promotes more than two fundamentally different reactions in a single reactor. An overview of recent and significant achievements in auto‐tandem catalysis is presented in this paper.
Nickel‐Catalyzed Cross‐Coupling of Alkyl Zinc Halides for the Formation of C(sp2)C(sp3) Bonds: Scope and Mechanism
Authors: Phapale Vilas B. , Guisán‐Ceinos Manuel , Buñuel Elena , Cárdenas Diego J.
Published: October 2009

Optimal conditions for a general Ni‐catalysed Negishi cross‐coupling of alkyl zinc halides with aryl, heteroaryl and alkenyl halides have been determined. These conditions allow the reaction to take place smoothly, with low catalyst loading, and in the presence of a wide variety of functional groups to afford products in good yields at room temperature. DFT studies on the mechanism support the occurrence of a catalytic cycle involving transmetalation of the alkyl zinc halide to NiI followed by oxidative addition of the haloarene and CC reductive elimination.
Theoretical Investigation on the Effect of Different Nitrogen Donors on Intramolecular Se⋅⋅⋅N Interactions
Authors: Sarma Bani Kanta , Mugesh Govindasamy
Published: October 2009

The effect of different donor nitrogen atoms on the strength and nature of intramolecular Se⋅⋅⋅N interactions is evaluated for organoselenium compounds havingN,N‐dimethylaminomethyl (dime), oxazoline (oxa) and pyridyl (py) substituents. Quantum chemical calculations on three series of compounds [2‐(dime)C6H4SeX (1 a–g), 2‐(oxa)C6H4SeX (2 a–g), 2‐(py)C6H4SeX (3 a–g); X=Cl, Br, OH, CN, SPh, SePh, CH3] at the B3LYP/6‐31G(d) level show that the stability of different conformers depends on the strength of intramolecular nonbonded Se⋅⋅⋅N interactions. Natural bond orbital (NBO), NBO deletion and atoms in molecules (AIM) analyses suggest that the nature of the Se⋅⋅⋅N interaction is predominantly covalent and involves nN→σ*SeXorbital interaction. In the three series of compounds, the strength of the Se⋅⋅⋅N interaction decreases in the order3>2>1for a particular X, and it decreases in the order Cl>Br>OH>SPh≈CN≈SePh>CH3for all the three series1–3. However, further analyses suggest that the differences in strength of Se⋅⋅⋅N interaction in1–3is predominantly determined by the distance between the Se and N atoms, which in turn is an outcome of specific structures of1,2and3, and the nature of the donor nitrogen atoms involved has very little effect on the strength of Se⋅⋅⋅N interaction. It is also observed that Se⋅⋅⋅N interaction becomes stronger in polar solvents such as CHCl3, as indicated by the shorterrSe⋅⋅⋅Nand higherESe⋅⋅⋅Nvalues in CHCl3compared to those observed in the gas phase.
Decision making in depression: differences in decisional conflict between healthy and depressed individuals
Authors: van Randenborgh Annette , de Jong‐Meyer Renate , Hüffmeier Joachim
Published: October 2009

This study investigated differences in the emergence of decisional conflict in healthy and depressed participants. The two groups of interest were questioned about their experience of decisional conflict and ongoing thoughts and impressions during decision making. As predicted, depressed participants experienced more decisional conflict than healthy participants. Furthermore, the diverse processes hypothesis was supported: In healthy participants, preoccupation with the task was the only predictor of decisional conflict. In depressed participants, decisional conflict was predicted by a combination of depression‐related processes (e.g., low self‐efficacy, lack of concentration, rumination, etc.). This research reduces the gap between the relevance of the symptom of indecisiveness (e.g., for diagnostic purposes) and the lack of knowledge in this realm of psychopathology. Copyright © 2009 John Wiley & Sons, Ltd.

Key Practitioner Message:

Depressed inpatients report more every day decisional conflict than healthy people. Practitioners should be aware of this symptom of depression that has not received much attention in research and practice yet.

Beyond this quantitative difference, there is also a qualitative difference between the decisional conflict experienced by depressed and healthy individuals: While healthy individuals' decisional conflict revolves around a thorough consideration of the decision task, depressed individuals' decisional conflict seems to be characterized by an inward focus of attention. They engage in an evaluation of their personal resources and competences as a decision maker.

Improving self‐efficacy and reducing feelings of helplessness related to decision making should alleviate decisional conflict in depressed people. These means may thus constitute a powerful intervention to reduce every day stress for patients and enhance recovery from depression.

This research highlights the detrimental effects of self‐focused thinking in depression. Decision making seems to be another task that is negatively affected by this type of depressogenic thinking. Interventions tackling depressive rumination appear beneficial in the light of this study.
Synthesis of Functionalized Bicyclo[3.2.0]heptanes – a Study of the [2+2] Photocycloaddition Reactions of 4‐Hydroxycyclopent‐2‐enone Derivatives
Authors: Le Liepvre Matthieu , Ollivier Jean , Aitken David J.
Published: October 2009

A selection of 4‐hydroxycyclopent‐2‐enone derivatives were prepared in enantiomerically pure form, and their photochemical [2+2] cycloaddition reactions with a variety of alkenes were studied, with a view to providing diversely functionalized bicyclo[3.2.0]heptanes. Intermolecular reactions provided the target structures in reasonable yields as a mixture of exo and endo adducts, in proportions which varied very little as a function of the steric bulk of the reactants or the reaction conditions. The system was suitably adapted for an intramolecular reaction, which provided a single, stereochemically pure product, the convenient precursor of a rigid, concave, trioxygenated skeleton. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Sterility testing by CE: A comparison of online preconcentration approaches in capillaries with greater internal diameters
Authors: Petr Jan , Jiang Chunxia , Sevcik Juraj , Tesarova Eva , Armstrong Daniel W.
Published: October 2009

Detection of microbial contamination is of critical importance in the medical and the food industry. Rapid tests for the absence or presence of viable microorganisms are in urgent demand. CE is a modern analytical technique that can be adapted for rapid screening of microbial contamination. However, the small dimensions of capillaries allow the introduction of only a small fraction of the sample, which can be problematic when examining large samples. In this article, we examine the possibilities of introducing larger sample volumes using capillaries with greater id together with different stacking techniques. The use of 0.32 mm id capillary and the injection of 60% of the capillary volume led to approximately 120‐fold improvement of the injected sample volume over the classical injection 5% of a 0.10‐mm id capillary. The setup we described opens new possibilities in sterility testing using CE.
The interspecific relationships of Astragalus species in Egypt assessed by the morpho‐anatomical characters of the pod
Authors: Mourad M. M. , Sharawy S. M.
Published: October 2009

The pod morphological and anatomical characters of 20 species, one subspecies and five varieties of Astragalus out of the 32 species growing in Egypt were investigated by LM and SEM, and numerically analysed to show the inter‐ as well as the infra‐specific relationships. It was concluded that both A. trimestris and A. corrugatus show marked affinity to other species investigated in the present work. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Geranium jaramilloi (Geraniaceae), a new species from Colombia
Authors: Aedo C.
Published: October 2009

A new species of Geranium L. (Geraniaceae), Geranium jaramilloi Aedo, sp. nova, is described and illustrated. The new species is morphologically most similar to G. santanderiense and G. lainzii. Geranium jaramilloi is easily distinguished by its leaves with entire segments (3‐lobed in G. santanderiense), and with abundant, patent, long and stout, eglandular hairs on both surfaces, although restricted to nerves abaxially (usually glabrous, and with a noticeable ciliate margin in G. santanderiense). Leaves also distinguished very well G. jaramilloi from G. lainzii, having the latter subtruncate leaves with 3‐lobed segments and scattered hairs near leaf margin. The new species belongs to sect. Gracilia, a group endemic to Colombia and Venezuela, characterized by its herbaceous and well developed stem, 2‐flowered cymules and inflorescence with dichasial branching. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Hereditary gastrointestinal stromal tumors sharing the KIT Exon 17 germline mutation p.Asp820Tyr develop through different cytogenetic progression pathways
Authors: Veiga Isabel , Silva Mara , Vieira Joana , Pinto Carla , Pinheiro Manuela , Torres Lurdes , Soares Marta , Santos Lúcio , Duarte Hugo , Bastos Artur L. , Coutinho Camila , Dinis José , Lopes Carlos , Teixeira Manuel R.
Published: October 2009

Hereditary gastrointestinal stromal tumor (GIST) syndrome is a rare autosomal dominant genetic disorder originated by germline mutations in the KIT or PDGFRA genes. We report the third family with hereditary predisposition to GIST due to the KIT Exon 17 germline mutation p.Asp820Tyr and characterize the cytogenetic progression pathways followed by different GIST sharing the same primary genetic event, using a combination of chromosome banding, comparative genomic hybridization (CGH), and fluorescence in situ hybridization (FISH) analyses. The missense mutation p.Asp820Tyr was detected in the proband's rectal and gastric GIST, as well as in his aunt's GIST epiplon metastasis. The mutation p.Asp820Tyr was subsequently also found in the proband's peripheral blood DNA, as well as in that of 4 of 10 relatives thus far analyzed. CGH analysis revealed loss of 14q and 15q in the proband's gastric lesion, whereas FISH analysis of the proband's rectal GIST did not detect loss of 14q and 15q, but instead loss of 4q and 22q and gain of 20q, indicating that the two tumors were independent GIST. Chromosome banding and CGH analyses of the aunt's GIST epiplon metastasis revealed multiple cytogenetic alterations, including 1p loss, but none in common with the two proband's GIST. We conclude that, although the patients share the same KIT Exon 17 germline mutation, the multiple GIST analyzed followed different pathogenetic progression pathways, each of which did not significantly differ from what has been described in sporadic GIST. © 2009 Wiley‐Liss, Inc.
Genome‐wide scan identifies a copy number variable region at 3q26 that regulates PPM1L in APC mutation‐negative familial colorectal cancer patients
Authors: Thean L. F. , Loi C. , Ho K. S. , Koh P. K. , Eu K. W. , Cheah P. Y.
Published: October 2009

Familial adenomatous polyposis (FAP) is an autosomal dominantly inherited form of colorectal cancer (CRC) caused by mutation in the adenomatous polyposis coli (APC) gene. However, APC mutations are not detected in 10–50% of FAP patients. We searched for a new cancer gene by performing genome‐wide genotyping on members of an APC mutation‐negative FAP variant family and ethnicity‐matched healthy controls. No common copy number change was found in all affected members using the unaffected members and healthy controls as baseline. A 111 kb copy number variable (CNV) region at 3q26.1 was shown to have copy number loss in all eight polyps compared to matched lymphocytes of two affected members. A common region of loss in all polyps, which are precursors to CRC, is likely to harbor disease‐causing gene in accordance to Knudsen's “two‐hit” hypothesis. There is, however, no gene within the deleted region. A 2‐Mb scan of the genomic region encompassing the deleted region identified PPM1L, coding for a novel serine‐threonine phosphatase in the TGF‐β and BMP signaling pathways. Real‐time PCR analyses indicate that the 3′UTR of PPM1L transcript was down‐regulated more than two‐folds in all six polyps and tumors compared to matched mucosa of the affected member. This down‐regulation was not observed in APC mutation‐positive FAP patients. Our results suggest that the CNV region at 3q26 harbors an element that regulates the expression of an upstream candidate tumor suppressor, PPM1L, thus providing a novel mechanism for colorectal tumorigenesis in APC mutation‐negative familial CRC patients. © 2009 Wiley‐Liss, Inc.
In silico prediction and screening of γ‐secretase inhibitors by molecular descriptors and machine learning methods
Authors: Yang Xue‐Gang , Lv Wei , Chen Yu‐Zong , Xue Ying
Published: October 2009

γ‐Secretase inhibitors have been explored for the prevention and treatment of Alzheimer's disease (AD). Methods for prediction and screening of γ‐secretase inhibitors are highly desired for facilitating the design of novel therapeutic agents against AD, especially when incomplete knowledge about the mechanism and three‐dimensional structure of γ‐secretase. We explored two machine learning methods, support vector machine (SVM) and random forest (RF), to develop models for predicting γ‐secretase inhibitors of diverse structures. Quantitative analysis of the receiver operating characteristic (ROC) curve was performed to further examine and optimize the models. Especially, the Youden index (YI) was initially introduced into the ROC curve of RF so as to obtain an optimal threshold of probability for prediction. The developed models were validated by an external testing set with the prediction accuracies of SVM and RF 96.48 and 98.83% for γ‐secretase inhibitors and 98.18 and 99.27% for noninhibitors, respectively. The different feature selection methods were used to extract the physicochemical features most relevant to γ‐secretase inhibition. To the best of our knowledge, the RF model developed in this work is the first model with a broad applicability domain, based on which the virtual screening of γ‐secretase inhibitors against the ZINC database was performed, resulting in 368 potential hit candidates. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2010
Efficient nonbonded interactions for molecular dynamics on a graphics processing unit
Authors: Eastman Peter , Pande Vijay S.
Published: October 2009

We describe an algorithm for computing nonbonded interactions with cutoffs on a graphics processing unit. We have incorporated it into OpenMM, a library for performing molecular simulations on high‐performance computer architectures. We benchmark it on a variety of systems including boxes of water molecules, proteins in explicit solvent, a lipid bilayer, and proteins with implicit solvent. The results demonstrate that its performance scales linearly with the number of atoms over a wide range of system sizes, while being significantly faster than other published algorithms. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2010
Regulation of stemness and stem cell niche of mesenchymal stem cells: Implications in tumorigenesis and metastasis
Authors: Kuhn Nastaran Z. , Tuan Rocky S.
Published: October 2009

Human mesenchymal stem cells (MSCs) derived from adult tissues have been considered a candidate cell type for cell‐based tissue engineering and regenerative medicine. These multipotent cells have the ability to differentiate along several mesenchymal lineages and possibly along non‐mesenchymal lineages. MSCs possess considerable immunosuppressive properties that can influence the surrounding tissue positively during regeneration, but perhaps negatively towards the pathogenesis of cancer and metastasis. The balance between the naïve stem state and differentiation is highly dependent on the stem cell niche. Identification of stem cell niche components has helped to elucidate the mechanisms of stem cell maintenance and differentiation. Ultimately, the fate of stem cells is dictated by their microenvironment. In this review, we describe the identification and characterization of bone marrow‐derived MSCs, the properties of the bone marrow stem cell niche, and the possibility and likelihood of MSC involvement in cancer progression and metastasis. J. Cell. Physiol. 222: 268–277, 2010. © 2009 Wiley‐Liss, Inc.
Molecular mechanism underlying muscle mass retention in hibernating bats: Role of periodic arousal
Authors: Lee Kisoo , So Hyekyoung , Gwag Taesik , Ju Hyunwoo , Lee Ju‐Woon , Yamashita Masamichi , Choi Inho
Published: October 2009

Hibernators like bats show only marginal muscle atrophy during prolonged hibernation. The current study was designed to test the hypothesis that hibernators use periodic arousal to increase protein anabolism that compensates for the continuous muscle proteolysis during disuse. To test this hypothesis, we investigated the effects of 3‐month hibernation (HB) and 7‐day post‐arousal torpor (TP) followed by re‐arousal (RA) on signaling activities in the pectoral muscles of summer‐active (SA) and dormant Murina leucogaster bats. The bats did not lose muscle mass relative to body mass during the HB or TP‐to‐RA period. For the first 30‐min following arousal, the peak amplitude and frequency of electromyographic spikes increased 3.1‐ and 1.4‐fold, respectively, indicating massive myofiber recruitment and elevated motor signaling during shivering. Immunoblot analyses of whole‐tissue lysates revealed several principal outcomes: (1) for the 3‐month HB, the phosphorylation levels of Akt1 (p‐Akt1) and p‐mTOR decreased significantly compared to SA bats, but p‐FoxO1 levels remained unaltered; (2) for the TP‐to‐RA period, p‐Akt1 and p‐FoxO1 varied little, while p‐mTOR showed biphasic oscillation; (3) proteolytic signals (i.e., atrogin‐1, MuRF1, Skp2 and calpain‐1) remained constant during the HB and TP‐to‐RA period. These results suggest that the resistive properties of torpid bat muscle against atrophy might be attained primarily by relatively constant proteolysis in combination with oscillatory anabolic activity (e.g., p‐mTOR) corresponding to the frequency of arousals occurring throughout hibernation. J. Cell. Physiol. 222: 313–319, 2010. © 2009 Wiley‐Liss, Inc.
Antioxidant activity and properties of gelatin films incorporated with tea polyphenol‐loaded chitosan nanoparticles
Authors: Bao Shibao , Xu Shiying , Wang Zhang
Published: October 2009

BACKGROUND: Gelatin film is widely used for the protection of food quality. In order to improve its antioxidant activity, natural antioxidant tea polyphenol‐loaded chitosan nanoparticles (TPCN) were prepared and incorporated into gelatin film. The antioxidant effect of TPCN against the oxidation of fish oil was investigated, as well as the release of TP from nanoparticles in the film.

RESULTS: The incorporation of TPCN greatly decreased the tensile strength and oxygen permeability but increased the water vapour permeability and affected the transparency of gelatin film. Scanning electron microscopy images indicated that extensive interference was embedded with TPCN in the film microstructure. The peroxide value of fish oil packaged with films incorporated with TPCN was lower than that of fish oil packaged with control films during the incubation period. The radical‐scavenging activity of films incorporated with TPCN was higher than that of control films, and increasing radical‐scavenging activity of the former was observed during the storage period.

CONCLUSION: The antioxidant activity and properties of gelatin film were affected by TPCN incorporation and storage time. Also, the oxidation of fish oil was retarded. The addition of TPCN could improve the antioxidant activity of gelatin film, and the release of TP from nanoparticles in the film was achieved during the storage period. Copyright © 2009 Society of Chemical Industry