bluuebunny/crossref_metadata_2025 huggingface dataset:
GM2 gangliosidosis in Saudi Arabia: Multiple mutations and considerations for future carrier screening
Authors: Kaya Namik , Owain Mohammad Al‐ , AbuDheim Nada , Zahrani Jawaher Al‐ , Colak Dilek , Sayed Moeen Al‐ , Milanlioglu Aysel , Ozand Pinar T. , Alkuraya Fowzan S.
Published: May 2011

The GM2 gangliosidose, Tay–Sachs and Sandhoff diseases, are a class of lysosomal storage diseases in which relentless neurodegeneration results in devastating neurological disability and premature death. Primary prevention is the most effective intervention since no effective therapy is currently available. An extremely successful model for the prevention of GM2 gangliosidosis in the Ashkenazi Jewish community is largely attributable to the very limited number of founder mutations in that population. Consistent with our previous observation of allelic heterogeneity in consanguineous populations, we show here that these diseases are largely caused by private mutations which present a major obstacle in replicating the Ashkenazi success story. Alternative solutions are proposed which can also be implemented for other autosomal recessive diseases in our population. © 2011 Wiley‐Liss, Inc.
Age related change in social behavior in children with Angelman syndrome
Authors: Adams Dawn , Horsler Kate , Oliver Chris
Published: May 2011

We investigated the relationship between age and laughing and smiling in children with Angelman syndrome. Twenty‐four children with Angelman syndrome were exposed to three experimentally manipulated conditions: proximity only, restricted social interaction, and social interaction. Children smiled the most in the social interaction condition and the least in the proximity only condition confirming the effect of social interaction on these behaviors. There was a decline in smiling and laughing in the oldest group (13.4–15.9 years) only in the social interaction condition. This trajectory of a decline in resource soliciting behaviors with age is consistent with predictions based on kinship theory. © 2011 Wiley‐Liss, Inc.
Extending the phenotype of lethal skeletal dysplasia type al Gazali
Authors: Grigelioniene Giedre , Papadogiannakis Nikos , Conner Peter , Geiberger Stefan , Nishikawa Masanori , Nakayama Masahiro
Published: May 2011

In this study, we describe the clinical and radiological phenotype of two patients with a rare skeletal dysplasia type al Gazali. The phenotype is characterized by brachycephaly, flat face, hypertelorism, low‐set ears, hypertrichosis, hypoplastic thorax, as well as short extremities with brachydactyly. Further characteristics are severe fetal hydrops, radiologic signs of increased bone density and short, poorly modeled tubular bones with wide diaphysis and smooth, rounded metaphyses. Cortical bones as well as vertebral endplates are thick and the skull is sclerotic with prominent parietal bones and a large anterior fontanel. Our cases suggest that skeletal dysplasia type al Gazali is a lethal condition and provide further evidence that it is inherited in an autosomal recessive manner. Both morphological and radiological features of these patients are very similar, which together with the previous report may indicate the presence of a new clinical entity in the group of skeletal dysplasias with increased bone density and metaphyseal and diaphyseal involvement. Surprisingly, histological analysis of the bone tissue and the growth plate shows completely normal structure, which suggests that the skeletal dysplasia type al Gazali is a systemic disorder resulting in increased bone density and restricted growth of the skeleton. © 2011 Wiley‐Liss, Inc.
Type 1 collagenopathy presenting with a Russell–Silver phenotype
Authors: Parker Michael J. , Deshpande Charulata , Rankin Julia , Wilson Louise C. , Balasubramanian Meena , Hall Christine M. , Wagner Bart E. , Pollitt Rebecca , Dalton Ann , Bishop Nicholas J.
Published: May 2011

Osteogenesis imperfecta (OI) is a heterogeneous group of inherited disorders of bone formation, resulting in low bone mass and an increased propensity to fracture. It exhibits a broad spectrum of clinical severity, ranging from multiple fractures in utero and perinatal death, to normal adult stature and low fracture incidence. Extra‐skeletal features of OI include blue sclera, hearing loss, skin hyperlaxity, joint hyperextensibility, and dentinogenesis imperfecta. The proα1(I) and proα2(I) chains of collagen 1 are encoded by theCOL1A1andCOL1A2genes, respectively; quantitative or qualitative defects in type I collagen synthesis usually manifest as types of OI or some sub‐types of EDS. The majority of patients (about 90%) with a clinical diagnosis of OI have a mutation in theCOL1A1orCOL1A2genes, which shows an autosomal dominant pattern of inheritance. Six other genes,CRTAP,LEPRE1,FKBP10,PP1B,SP7/Osterix(OSX), andSERPINH1, are associated with autosomal recessive forms of OI. However, other, rare phenotypes have also been described. There are many differential diagnoses of the short, syndromic child, including chromosomal, single gene, and multifactorial causes. However, one condition of particular relevance in the context of this report is the Russell–Silver syndrome (RSS). As originally described, the RSS is a very specific condition. However, it has subsequently become an umbrella term for a heterogeneous group of conditions presenting with short stature and triangular shape to the face. A significant proportion of these are now believed to be due to imprinting defects at 11p15. However, the cause in many cases remains unknown. We describe two cases with a phenotypic overlap between OI and RSS who both haveCOL1A1mutations. Thus, a type 1 collagenopathy should be considered in the differential diagnosis of syndromic short stature. © 2011 Wiley‐Liss, Inc.
NOA‐05 phase 2 trial of procarbazine and lomustine therapy in gliomatosis cerebri
Authors: Glas Martin , Bähr Oliver , Felsberg Jörg , Rasch Katja , Wiewrodt Dorothee , Schabet Martin , Simon Matthias , Urbach Horst , Steinbach Joachim P. , Rieger Johannes , Fimmers Rolf , Bamberg Michael , Nägele Thomas , Reifenberger Guido , Weller Michael , Herrlinger MD Ulrich , Group of the German Cancer Society for the Neuro‐Oncology
Published: May 2011

Objective:

The NOA‐05 multicenter trial was performed to analyze the efficacy of primary chemotherapy with procarbazine and lomustine (PC) in patients with gliomatosis cerebri (GC) and to define clinical, imaging, and molecular factors influencing outcome.

Methods:

Thirty‐five patients with previously untreated GC were treated with up to six 56‐day courses of 110mg/m2 lomustine on day 1 and 60mg/m2 procarbazine on days 8 to 21. The primary endpoint was the rate of patients without therapy failure (defined as progressive disease, death from any cause, or termination of PC therapy before the end of course 4) at 8 months after the beginning of PC chemotherapy.

Results:

The failure‐free survival rate at 8 months was 50.3%. Median progression‐free survival was 14 months. At progression, 12 patients received salvage radiotherapy. Median overall survival was 30 months. Multivariate analysis revealed isocitrate dehydrogenase 1 (IDH1) gene mutation (hazard ratio [HR], 0.11; 95% confidence interval [CI], 0.02–0.58) and initial presentation without a bilateral symmetrical infiltration pattern on magnetic resonance imaging (HR 0.07, 95%CI 0.01‐0.54) as independent prognostic factors associated with prolonged survival. IDH1 mutation was significantly associated with MGMT promoter methylation and an oligodendroglial tumor component.

Interpretation:

PC chemotherapy is effective in GC. With the NOA‐05 trial being the first prospective multicenter trial in GC, PC chemotherapy can be regarded as a promising option for the primary therapy of these tumors. Ann Neurol 2011;
Biodegradable amphiphiles of grafted poly(lactide) onto 2‐hydroxyethyl methacrylate‐co‐N‐vinylpyrrolidone copolymers as drug carriers
Authors: Fares Mohammad M. , Assaf Shereen M. , Jaber Anees A.
Published: May 2011

This article describes the synthesis and characterization of 2‐hydroxylethyl methacrylate‐co‐N‐vinylpyrrolidone copolymers, (HEMA‐co‐NVP), via free radical polymerization followed by grafting of poly(lactide) onto (HEMA‐co‐NVP) copolymers, via ring opening polymerization using tin octoate as a catalyst. The copolymers and the grafted copolymers (i.e., amphiphiles) were subjected to sustained release studies using salicylic acid, as a model drug. Characterization of the formed copolymers was performed using 1H‐NMR, 13C‐NMR, FTIR, TGA, DSC, and SEM techniques. Derivative of TGA thermogram was used to determine %hydrophilicity and %hydrophobicity in the grafted and ungrafted copolymers. The SEM morphology revealed porous layers with crispy structure that were most likely due to the presence of poly(lactide) chains. At lower content of poly(lactide) moiety, grafted copolymers showed non‐Fickian diffusion release rate, whereas Fickian diffusion release rate at higher content of poly(lactide) was observed. The increase of poly(lactide) content (i.e., larger %hydrophobicity) in the copolymer increased the drug‐sustainability, due to the consistent but porous amphiphilic degradable structures that allow controllable release of drug in time interval. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
The influence of membrane formation parameters on structural morphology and performance of PES/PDMS composite membrane for gas separation
Authors: Madaeni Sayed S. , Enayati Enayat , Vatanpour Vahid
Published: May 2011

In this study, influence of membrane preparation parameters on structural morphology and performance of polyethersulfone/polydimethylsiloxane (PES/PDMS) composite membrane was investigated for gas separation. Asymmetric PES flat sheet membranes were composed by phase inversion method and used as supports. PES composite membranes were fabricated by coating silicone rubber as selective layer on the top surface of support. Effects of different concentrations of PES and PDMS, solvent type, and support thickness on membrane performance were investigated for separation of oxygen from nitrogen. The optimized superior membrane was further modified using polyvinylidenfluoride, methanol and ethanol as additives in PES solutions and/or in water coagulation bath to promote the membrane capability. The results showed that addition of ethanol and methanol in cast solution and coagulation bath can greatly affect the morphology and hence the performance of the prepared membranes. The permeance changes have the contrary trend with solubility parameter difference between solvent and nonsolvent mixture, for instance when this parameter difference was lowest, higher permeance was obtained. Support and coating polymer concentration can control the permeance. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Association of accelerated switch from vertebral end‐plate Modic I to Modic 0 signal changes with clinical benefit of intradiscal corticosteroid injection for chronic low back pain
Authors: Nguyen Christelle , Bénichou Marc , Revel Michel , Poiraudeau Serge , Rannou François
Published: May 2011

Modic I vertebral end‐plate signal changes detected by magnetic resonance imaging (MRI) are associated with chronic low back pain. Typically, Modic I signal changes in untreated patients switch to non–Modic I signal changes within 3 years, which reflect spontaneous healing. Recent findings suggest that Modic I signal changes may be related to local inflammatory changes, providing a rationale for treatment with intradiscal injections of antiinflammatory drugs. In the present report, we describe a 31‐year‐old man with 1‐year history of chronic low back pain associated with vertebral end‐plate Modic I signal changes, who received 1 intradiscal corticosteroid injection in L5–S1. Local treatment led to rapid pain relief and was associated with an accelerated switch from Modic I to Modic 0 signal changes, as seen on lumbar MRI at 1‐month followup. This is the first report of an effective local treatment for both the symptoms and the structural changes of chronic low back pain that are associated with Modic I signal changes. Additionally, this case reinforces the hypothesis that local inflammation has a pathogenic role.
Resolution of neutrophilic inflammation by H2O2 in antigen‐induced arthritis
Authors: Lopes Fernando , Coelho Fernanda M. , Costa Vivian V. , Vieira Érica L. M. , Sousa Lirlândia P. , Silva Tarcília A. , Vieira Leda Q. , Teixeira Mauro M. , Pinho Vanessa
Published: May 2011

Objective

Neutrophil accumulation contributes to the pathogenesis of rheumatoid arthritis. This study was undertaken to examine the ability of H2O2 to influence neutrophilic inflammation in a model of antigen‐induced arthritis (AIA) in mice.

Methods

AIA was induced by administration of antigen into the knee joints of previously immunized mice. Neutrophil accumulation was measured by counting neutrophils in the synovial cavity and assaying myeloperoxidase activity in the tissue surrounding the mouse knee joint. Apoptosis was determined by morphologic and molecular techniques. The role of H2O2 was studied using mice that do not produce reactive oxygen species (gp91phox−/− mice) and drugs that enhance the generation or enhance the degradation of H2O2.

Results

Antigen challenge of immunized mice induced neutrophil accumulation that peaked at 12–24 hours after challenge. H2O2 production peaked at 24 hours, after which time, the inflammation resolved. Neutrophil recruitment was similar in wild‐type and gp91phox−/− mice, but there was delayed resolution in gp91phox−/− mice or after administration of catalase. In contrast, administration of H2O2 or superoxide dismutase (SOD) resolved neutrophilic inflammation. The resolution of inflammation induced by SOD or H2O2 was accompanied by an increase in the number of apoptotic neutrophils. Apoptosis was associated with an increase in Bax and caspase 3 cleavage and was secondary to phosphatidylinositol 3‐kinase (PI3K)/Akt activation.

Conclusion

Our findings indicate that levels of H2O2 increase during neutrophil influx and are necessary for the natural resolution of neutrophilic inflammation. Mechanistically, enhanced levels of H2O2 (endogenous or exogenous) inhibit p‐Akt/NF‐κB and induce apoptosis of migrated neutrophils. Modulation of H2O2 production may represent a novel strategy for controlling neutrophilic inflammation in the joints.
Formal body bequest program in Nigerian medical schools: When do we start?
Authors: Akinola Oluwole Busayo
Published: May 2011

Human body dissection is a prerequisite for the training of health professionals and the conduct of medical research. However, most Nigerian medical schools experience difficulty obtaining an adequate and regular supply of human tissue. Presently, the major source of anatomical material comes from unclaimed bodies collected from hospital mortuaries. However, one sure way to ensure a regular supply of bodies for anatomical dissection is to establish a whole body bequest program among the departments of anatomy in Nigerian medical schools. If such a program were to be supported by an appropriate legislative act of parliament, the supply of acceptable cadavers for anatomical teaching and research would be substantially increased. The author advocates for establishing a whole body bequest program among Nigerian medical schools. Anat Sci Educ. © 2011 American Association of Anatomists.
Location‐based questions and local knowledge
Authors: Bishop Bradley Wade
Published: May 2011

This article explores location‐based questions, local knowledge, and the implications stemming from these concepts for digital reference staff in consortial question‐ answering services. Location‐based questions are inquiries that concern a georeferencable site. Digital reference personnel staffing the statewide chat reference consortium used in this study respond to location‐based questions concerning over 100 participating information agencies. Some literature has suggested that nonlocal digital reference staff have difficulties providing accurate responses to location‐based questions concerning locations other than their own. This study utilized content analysis to determine the quantity of location‐based questions and the question‐negotiation process in responding to location‐based questions. Key findings indicate location‐based questions comprised 50.2% of the total questions asked to the statewide service, 73.6% of location‐based questions were responded to by nonlocal digital reference staff, and 37.5% of location‐based questions ended in referral. This article's findings indicate that despite digital reference's capability to provide anyplace, anytime question‐answering service, proximity to local knowledge remains relevant.
Intramolecular Aromatic Carbenoid Insertion of Biaryldiazoacetates for the Regioselective Synthesis of Fluorenes
Authors: Kim Jinho , Ohk Youhwa , Park Sae Hume , Jung Yousung , Chang Sukbok
Published: May 2011

The rhodium‐ or copper‐catalyzed intramolecular aromatic carbenoid insertion of biaryldiazoacetates offers a convenient route to fluorene carboxylates with high yields. Whereas, thermal conditions provided a mixture of two regioisomeric products when substituted biaryldiazoacetates were employed as substrates. The developed catalytic conditions displayed an excellent level of regioselectivity, presumably owing to steric effects. The insertion mechanism was assumed to be an electrophilic aromatic substitution, which was supported by preliminary mechanistic studies. A chloro‐substituted fluorene derivative was efficiently synthesized and utilized as a base‐sensitive protecting group of amines.
Renewable energy targets, forest resources, and second‐generation biofuels in Finland
Authors: Heinimö Jussi , Malinen Heikki , Ranta Tapio , Faaij André
Published: May 2011

Introduction of second‐generation biofuels is an essential factor for meeting the EU's 2020 targets for renewable energy in the transport sector and enabling the more ambitious targets for 2030. Finland's forest industry is strongly involved in the development and commercializing of second‐generation biofuel production technologies. The goal of this paper is to provide a quantified insight into Finnish prospects for reaching the 2020 national renewable energy targets and concurrently becoming a large‐scale producer of forest‐biomass‐based second‐generation biofuels feeding the increasing demand in European markets. The focus of the paper is on assessing the potential for utilizing forest biomass for liquid biofuels up to 2020. In addition, technological issues related to the production of second‐generation biofuels were reviewed. Finland has good opportunities to realize a scenario to meet 2020 renewable energy targets and for large‐scale production of wood‐based biofuels. In 2020, biofuel production from domestic forest biomass in Finland may reach nearly a million ton (40 PJ). With the existing biofuel production capacity (20 PJ/yr) and the national biofuel consumption target (25 PJ) taken into account, the potential net export of biofuels from Finland in 2020 would be 35 PJ, corresponding to 2–3% of European demand. Commercialization of second‐generation biofuel production technologies, high utilization of the sustainable harvesting potential of Finnish forest biomass, and allocation of a significant proportion of the pulpwood harvesting potential for energy purposes are prerequisites for this scenario. Large‐scale import of raw biomass would enable remarkably greater biofuel production than is described in this paper. © 2011 Society of Chemical Industry and John Wiley & Sons, Ltd
Bioenergy policies in Africa: mainstreaming gender amid an increasing focus on biofuels
Authors: Molony Thomas
Published: May 2011

Many developing countries are now working to update their existing energy strategies and to formulate their bioenergy policies to accommodate rises in domestic and external supply and demand for biofuels. This paper presents a case for mainstreaming gender into African countries' bioenergy policies, and uses a review of the literature on gender and bioenergy to suggest some important avenues for future research to expand the current poor state of information on gender and the newer issue of biofuels. The paper opens with a brief discussion on the motivation for interest in biofuels in some African countries and suggests that in the integrated global context of biofuels, the conditions that generate inequality between rich and poor remain unchanged. It then discusses equity and energy poverty, and points to the lack of empirical evidence on gender issues relating specifically to biofuels. From this it turns to our knowledge of what the existing state of broader bioenergy use can tell us about bringing gender equity to African national bioenergy policies, and suggests that gender equity can be ‘energized’ through a perspective that focuses as much on social roles and relations between men and women as it does on ascribed responsibilities. National level bioenergy Policy Working Groups (PWGs) are then introduced as having an important role to play in ensuring that gender issues are mainstreamed into bioenergy policy within the context of the increasing focus on biofuels. © 2011 Society of Chemical Industry and John Wiley & Sons, Ltd
New energy and green entrepreneurship
Authors: Ragauskas Art J.
Published: May 2011

It is incumbent upon all of us to develop a highly skilled and green entrepreneurial workforce. © 2011 Society of Chemical Industry and John Wiley & Sons, Ltd
Eastern Europe on the way up in biodiesel and ethanol?
Authors: Covrig Claudiu
Published: May 2011

Eastern Europe is beginning to unveil an important biofuel and agricultural potential. Dr Claudiu Covrig, from Kingsman, reviews the progress that eastern EU countries have made toward exploiting disposable arable land for the production of biofuels, and considers which countries have the most potential. © 2011 Society of Chemical Industry and John Wiley & Sons, Ltd
Tools to evaluate the conformation of protein products
Authors: Manta Bruno , Obal Gonzalo , Ricciardi Alejandro , Pritsch Otto , Denicola Ana
Published: May 2011

Production of recombinant proteins is a process intensively used in the research laboratory. In addition, the main biotechnology market products are recombinant proteins and monoclonal antibodies. The biological (and clinical) properties of the protein product strongly depend on the conformation of the polypeptide. Therefore, assessment of the correct conformation of the produced protein is crucial. There is no single method to assess every aspect of protein structure or function. Depending on the protein, the methods of choice vary. There are general methods to evaluate not only mass and primary sequence of the protein, but also higher‐order structure. This review outlines the principal techniques for determining the conformation of a protein from structural (biophysical methods) to functional (in vitro binding assays) analyses.
Discovery of a Small Peptide from Combinatorial Libraries That Can Activate the Plant Immune System by a Jasmonic Acid Signaling Pathway
Authors: Miyashita Masahiro , Oda Masashi , Ono Yuji , Komoda Eriko , Miyagawa Hisashi
Published: May 2011

Plants defend themselves by using an innate immune system that is activated in response to a variety of molecules derived from pathogens. These molecules have provided profound insights into the mechanisms of pathogen recognition and subsequent signaling pathways in plants. In the present study, we screened a combinatorial random hexapeptide library for peptides that activate the plant immune system, by using a cell‐based high‐throughput screening system in which H2O2 generation was monitored. We discovered a novel small peptide (YGIHTH‐amide, PIP‐1) that triggered H2O2 production in tobacco and tomato cells, but not in Arabidopsis cells. PIP‐1 induced significant levels of phytoalexin biosynthesis and defense‐related gene expression in tobacco cells; this is likely to be activated by a jasmonic acid pathway.
Introduction to Proteins: Structure, Function and Motion. By Amit Kessel and Nir Ben‐Tal.
Authors: Sheehan David
Published: May 2011

CRC Press, Boca Raton 2011, XXVII+626 pp., hardcover $ 79.95.—ISBN 978‐4398‐1071‐2
Outcomes following treatment of femoropopliteal in‐stent restenosis: A single center experience
Authors: Yeo Khung‐Keong , Malik Umer , Laird John R.
Published: May 2011

Objectives: The aim of this study is to describe a single‐center experience with endovascular treatment of femoropopliteal in‐stent restenosis (ISR). Background: Femoropopliteal artery stenting is associated with a significant risk of ISR. Data are limited on the optimal treatment strategy and associated outcomes. Methods: A single institution retrospective chart review study was performed for patients who underwent endovascular treatment of femoropopliteal ISR from January 2006 to October 2008. Clinical and procedural characteristics, angiographic findings, and 12‐month primary and secondary patency rates were analyzed. Univariate analysis was performed to identify predictors of 12‐month primary patency. Results: Twenty‐two limbs were treated in 20 patients during the study period. Procedural success was achieved in 21 limbs (95.5%). Laser, balloon angioplasty, and excisional atherectomy were the primary therapy in 52.4%, 33.3%, and 14.3% of the cases, respectively. Adjunctive balloon angioplasty was performed after laser and excisional atherectomy in all cases. The mean length of ISR was 13.2 ± 11.3 cm with a significant proportion of cases (40.9%) having Type IV pattern of ISR. At 12 months, primary and combined primary‐assisted and secondary patency rates were 47.6 and 61.9%, respectively. Of the 11 limbs that did not have secondary patency, 6 had mild or no symptoms, and, therefore, repeat intervention was not performed. There was one transmetatarsal amputation during the 12‐month follow‐up period. In this study, there was no significant predictor of 12‐month primary patency. Conclusions: Treatment of ISR remains challenging with significant risk of recurrent restenosis. Further research is required to improve long‐term patency. © 2011 Wiley‐Liss, Inc.
Decreased risk of stent fracture‐related restenosis between paclitaxel‐eluting stents and sirolimus eluting stents: Results of long‐term follow‐up
Authors: Freixa Xavier , Almasood Ali S. , Khan Sohail Q. , Wainstein Rodrigo , Osherov Azriel , Mackie Karen , Seidelin Peter H. , Džavík Vladimír
Published: May 2011

Objective: To compare the outcomes between paclitaxel‐eluting stents (PES) and sirolimus‐eluting stents (SES) for the treatment of drug‐eluting stent (DES) fracture. Background: DES fracture is considered as an important predictor of in‐stent restenosis (ISR). However, little data are available evaluating the optimal treatment for this complication of coronary stenting. Methods: From January 1, 2004 to December 31, 2008, patients with DES ISR treated with a second DES were identified and evaluated for stent fracture. Stent fracture was defined by the presence of strut separation in multiple angiographic projections, assessed by two independent reviewers. Target lesion revascularization (TLR) at 6 and 12 months were the primary end points. Results:Of 131 lesions with DES ISR treated with a second DES, we found 24 patients (24 lesions, 18.2%) with angiographically confirmed stent fracture. Of these, 20 patients (20 lesions) treated with either PES (n = 11/55%) or SES (n = 9/45%) were included in the study. TLR at 6 months occurred in 9% of patients treated with PES and 22% of those treated with SES (P = 0.41). After 12 months, TLR was 9% and 55.5%, respectively (P = 0.024). Conclusions:This study demonstrates a high incidence of stent fracture in patients presenting with DES ISR in need of further treatment with another DES. The suggested association between treatment of stent fracture‐associated DES ISR with PES as compared with SES, and better long‐term outcomes, is in need of confirmation by larger prospective registries and randomized trials. © 2011 Wiley Periodicals, Inc.
A pH‐Responsive Cleavage Route Based on a Metal–Organic Coordination Bond
Authors: Xing Lei , Zheng Haoquan , Che Shunai
Published: May 2011

The physical or chemical event that generally causes stimuli responses is limited to the formation or destruction of secondary forces, such as hydrogen bonding, hydrophobic effects, electrostatic interactions, and simple reactions. Here, pH‐responsive behavior of metal–organic coordination bonding, which is intrinsic to natural systems (e.g., transferrin recycling in cells), is becoming a strong candidate for a new stimulus–responsive route. We have designed a simple pH‐responsive release system by integrating a metal ion and ligand or self‐assembling these species with biodegradable host molecules to form nanoparticles with “metal–ligand” or “host–metal–ligand” architectures. The cleavage of either or both the “metal–ligand” or the “host–metal” coordination bond in response to pH variations causes significant damage to the nanoparticles and the subsequent release of ligand molecules under designated pH conditions.
Robust and Efficient Amide‐Based Nonheme Manganese(III) Hydrocarbon Oxidation Catalysts: Substrate and Solvent Effects on Involvement and Partition of Multiple Active Oxidants
Authors: Song Young Joo , Lee Sun Hwa , Park Hyun Min , Kim Soo Hyun , Goo Hyo Geun , Eom Geun Hee , Lee Ju Hoon , Lah Myoung Soo , Kim Youngmee , Kim Sung‐Jin , Lee Ju Eun , Lee Hong‐In , Kim Cheal
Published: May 2011

Two new mononuclear nonheme manganese(III) complexes of tetradentate ligands containing two deprotonated amide moieties, [Mn(bpc)Cl(H2O)] (1) and [Mn(Me2bpb)Cl(H2O)]⋅CH3OH (2), were prepared and characterized. Complex 2 has also been characterized by X‐ray crystallography. Magnetic measurements revealed that the complexes are high spin (S=5/2) MnIII species with typical magnetic moments of 4.76 and 4.95 μB, respectively. These nonheme MnIII complexes efficiently catalyzed olefin epoxidation and alcohol oxidation upon treatment with MCPBA under mild experimental conditions. Olefin epoxidation by these catalysts is proposed to involve the multiple active oxidants MnVO, MnIVO, and MnIIIOO(O)CR. Evidence for this approach was derived from reactivity and Hammett studies, KIE (kH/kD) values, H218O‐exchange experiments, and the use of peroxyphenylacetic acid as a mechanistic probe. In addition, it has been proposed that the participation of MnVO, MnIVO, and MnIIIOOR could be controlled by changing the substrate concentration, and that partitioning between heterolysis and homolysis of the OO bond of a Mn‐acylperoxo intermediate (MnOOC(O)R) might be significantly affected by the nature of solvent, and that the OO bond of the MnOOC(O)R might proceed predominantly by heterolytic cleavage in protic solvent. Therefore, a discrete MnVO intermediate appeared to be the dominant reactive species in protic solvents. Furthermore, we have observed close similarities between these nonheme MnIII complex systems and Mn(saloph) catalysts previously reported, suggesting that this simultaneous operation of the three active oxidants might prevail in all the manganese‐catalyzed olefin epoxidations, including Mn(salen), Mn(nonheme), and even Mn(porphyrin) complexes. This mechanism provides the greatest congruity with related oxidation reactions by using certain Mn complexes as catalysts.
Direct Experimental Evidence for the High Chemical Reactivity of α‐ and β‐Xylopyranosides Adopting a 2,5B Conformation in Glycosyl Transfer
Authors: Amorim Luis , Marcelo Filipa , Rousseau Cyril , Nieto Lidia , Jiménez‐Barbero Jesús , Marrot Jérôme , Rauter Amélia P. , Sollogoub Matthieu , Bols Mikael , Blériot Yves
Published: May 2011

The effect of a 2,5B boat conformation on xyloside reactivity has been investigated by studying the hydrolysis and glycosylation of a series of synthetic xyloside analogues based on a 2‐oxabicyclo[2.2.2]octane framework, which forces the xylose analogue to adopt a 2,5B conformation. The locked β‐xylosides were found to hydrolyze 100–1200 times faster than methyl β‐D‐xylopyranoside, whereas the locked α‐xylosides hydrolyzed up to 2×104 times faster than methyl α‐D‐xylopyranoside. A significant rate enhancement was also observed for the glycosylation reaction. The high reactivity of these conformers can be related to the imposition of a 2,5B conformation, which approximates a transition state (TS) boat conformation. In this way, the energy penalty required to go from the chair to the TS conformation is already paid. These results parallel and support the observation that the GH‐11 xylanase family force their substrate to adopt a 2,5B conformation to achieve highly efficient enzymatic glycosidic bond hydrolysis.
Unmodified “GNP–Oligonucleotide” Nanobiohybrids: A Simple Route for Emission Enhancement of DNA Intercalators
Authors: Maiti Subhabrata , Dutta Sounak , Das Prasanta Kumar
Published: May 2011

We present herein a simple method for enhancing the emission of DNA intercalators in homogeneous nanobiohybrids of unlabeled oligonucleotides and unmodified gold nanoparticles (GNPs). Pristine single‐stranded DNA (ss‐DNA) has been wrapped around unmodified GNPs to induce metal‐enhanced fluorescence (MEF) of DNA intercalators, such as ethidium bromide and propidium iodide. The thickness of the ss‐DNA layer on the gold nanosurface determines the extent of MEF, since this depends on the position of the intercalator in relation to the metal surface. Presumably, at a suitable thickness of this DNA layer, more of the intercalator is localized at the optimum distance from the nanoparticle to give rise to MEF. Importantly, no external spacer or coating agent was needed to induce the MEF effect of the GNPs. The concentration ratios of Au to DNA in the nanohybrids, as well as the capping agents applied to the GNPs, play key roles in enhancing the emission of the intercalators. The dimensions of both components of the nanobiohybrids, that is, the size of the GNPs and the length of the oligonucleotide, have considerable influences on the emission enhancement of the intercalators. Emission intensity increased with increasing size of the GNPs and length of the oligonucleotide only when the DNA efficiently wrapped the nanoparticles. An almost 100 % increment in the quantum yield of ethidium bromide was achieved with the GNP–DNA nanobiohybrid compared with that with DNA alone (in the absence of GNP), and the fluorescence emission was enhanced by 50 % even at an oligonucleotide concentration of 2 nM. The plasmonic effect of the GNPs in the emission enhancement was also established by the use of similar nanobioconjugates of ss‐DNA with nonmetallic carbon nanoparticles and TiO2 nanoparticles, with which no increase in the fluorescence emission of ethidium bromide was observed.
Exploring the Oxidative Cyclization of Substituted N‐Aryl Enamines: Pd‐Catalyzed Formation of Indoles from Anilines
Authors: Neumann Julia J. , Rakshit Souvik , Dröge Thomas , Würtz Sebastian , Glorius Frank
Published: May 2011

The direct Pd‐catalyzed oxidative coupling of two CH‐bonds within N‐aryl‐enamines 1 allows the efficient formation of differently substituted indoles 2. In this cross‐dehydrogenative coupling, many different functional groups are tolerated and the starting material N‐aryl‐enamines 1 can be easily prepared in one step from commercially available anilines. In addition, the whole sequence can also be run in a one‐pot fashion. Optimization data, mechanistic insight, substrate scope, and applications are reported in this full paper.
ChemInform Abstract: Efficient and Highly Selective Method for the Synthesis of 4‐Iodo‐3‐substituted 1H‐Isoselenochromenes and ‐Isothiochromenes.
Authors: Schneider Caroline C. , Bortolatto Cristiani , Back Davi F. , Menezes Paulo H. , Zeni Gilson
Published: May 2011

The presented synthesis of the title compounds (IV) and (VII) via Sonogashira cross‐coupling reaction proceeds cleanly under mild conditions.
ChemInform Abstract: Nickel‐Catalyzed Negishi Cross‐Coupling Reactions of Secondary Alkylzinc Halides and Aryl Iodides.
Authors: Joshi‐Pangu Amruta , Ganesh Madhu , Biscoe Mark R.
Published: May 2011

In the presence of NiCl2 and terpyridine, a wide range of aromatic iodides are found to undergoes efficient and selective cross‐coupling with secondary alkylzinc halides to afford products of type (III) and (V).
ChemInform Abstract: Catalyst‐Free One‐Pot Reductive Alkylation of Primary and Secondary Amines and N,N‐Dimethylation of Amino Acids Using Sodium Borohydride in 2,2,2‐Trifluoroethanol.
Authors: Tajbakhsh Mahmood , Hosseinzadeh Rahman , Alinezhad Heshmatollah , Ghahari Somayeh , Heydari Akbar , Khaksar Samad
Published: May 2011

A simple procedure for the reductive amination of aldehydes (including formaldehyde) and ketones using NaBH4 is developed.
ChemInform Abstract: One‐Pot Synthesis of α‐Amino Acids from Imines Through CO2 Incorporation: An Alternative Method for Strecker Synthesis.
Authors: Mita Tsuyoshi , Chen Jianyang , Sugawara Masumi , Sato Yoshihiro
Published: May 2011

Starting from α‐amino sulfones, the synthesis of the esters (IV) is achieved via imine formation, stannylation, carboxylation and esterification.
ChemInform Abstract: Boric Acid Mediated N‐Acylation of Sulfoximines.
Authors: Garimallaprabhakaran Aswinkumar , Harmata Michael
Published: May 2011

Boric acid reacts with carboxylic acids to form reactive acylating agents which are intercepted by sulfoximes (I).
ChemInform Abstract: Palladium‐Catalyzed Coupling of N‐Tosylhydrazones with ortho Substituted Aryl Halides: Synthesis of 4‐Arylchromenes and Related Heterocycles.
Authors: Rasolofonjatovo Evelia , Treguier Bret , Provot Olivier , Hamze Abdallah , Morvan Estelle , Brion Jean‐Daniel , Alami Mouad
Published: May 2011

The one‐pot regioselective hydration of alkynes, N‐tosylhydrazene formation and Pd‐catalyzed coupling with aryl halides provides (Z)‐diarylolefins which are cyclized to afford heterocycles (VI) and (IX).
ChemInform Abstract: Enantioselective Haloetherification by Asymmetric Opening of meso‐Halonium Ions.
Authors: Hennecke Ulrich , Mueller Christian H. , Froehlich Roland
Published: May 2011

The approach is based on the selective opening of halonium ions in the presence of the chiral catalyst.
ChemInform Abstract: Gold‐Catalyzed Rearrangement of O‐Vinyl Oximes for the Synthesis of Highly Substituted Pyrroles.
Authors: Ngwerume Simbarashe , Camp Jason E.
Published: May 2011

O‐vinyl oximes, synthesized by reaction of oximes with alkynecarboxylates, undergo an unprecedented Au‐catalyzed rearrangement to yield pyrroles [e,g.
ChemInform Abstract: A Novel and One‐Pot Multicomponent Approach to the Synthesis of Dihydroindeno[1,2‐b]pyrroles and Indeno[2′,1′:4,5]pyrrolo[1,2‐a]‐Fused 1,3‐Diazaheterocycles.
Authors: Alizadeh Abdolali , Zarei Ameneh , Rezvanian Atieh
Published: May 2011

An easy, highly efficient, mild, and simple synthesis of the title compounds (IV) and (VI), which are heterocycles of potential synthetic and pharmalogical interest, is presented from readily available starting materials.
ChemInform Abstract: Nitropyridines. Part 10. Palladium‐Catalyzed Cross‐Coupling of 2‐Bromo‐5‐nitropyridine with Terminal Acetylenes.
Authors: Sagitullina G. P. , Vorontsova M. A. , Garkushenko A. K. , Poendaev N. V. , Sagitullin R. S.
Published: May 2011

The synthesis of a series of substituted 2‐ethynyl‐5‐nitropyridines and their transformation into difficultly accessible 2‐acetyl‐5‐nitropyridine and 5‐nitro‐2‐phenacylpyridine is presented.
ChemInform Abstract: Efficient Diverse Approach for Quinoxaline‐Derived Glycosylated and Morphinylated Analogues.
Authors: Beldi Razika , Atta Kamal F. , Aboul‐Ela Sallah , El Ashry El Sayed H.
Published: May 2011

The method is described as suitable for substance library creation.
ChemInform Abstract: Palladium‐Catalyzed Highly Regio‐ and Stereoselective Synthesis of 4‐Alkylidene‐4H‐3,1‐benzoxazines from N‐Acyl‐o‐alkynylanilines.
Authors: Saito Takao , Ogawa Shohei , Takei Naoya , Kutsumura Noriki , Otani Takashi
Published: May 2011

A new, straightforward, and highly selective method to prepare 4‐alkylidenebenzoxazines of type (II) and (IV) is reported.
ChemInform Abstract: Synthesis of 4‐(Substituted benzyl)‐1H,3H‐benzo[f]1,3,5‐triazepin‐2‐ones
Authors: Maruthikumar T. Venkata , Rao G. V. Panakala , Reddy V. Prabhakar , Rao P. Hanumantha
Published: May 2011

via reaction of o‐phenylenediamine (I) with 1,3,5‐oxadiazin‐2‐ones (II)
ChemInform Abstract: Synthesis and Structure—Activity Relationships of Novel Benzoxaboroles as a New Class of Antimalarial Agents.
Authors: Zhang Yong‐Kang , et al. et al.
Published: May 2011

Benzoxaborole (VII) as well as a series of analogues are designed to assess the structural features required for potent antimalarial activity.
ChemInform Abstract: Application of Bis(trimethylsilyl) Phosphonite in the Efficient Preparation of New Heterocyclic α‐Aminomethyl‐H‐phosphinic Acids.
Authors: Olszewski Tomasz K. , Boduszek Bogdan
Published: May 2011

A simple and reproducible synthesis of the title compounds (II) and the corresponding free acids (III), which are useful building blocks, e.g. in the synthesis of phosphinic pseudopeptides, is presented.
ChemInform Abstract: Hydrogenation and Conformational Analysis of (1R,2R,6S)‐3‐Methyl‐6‐(1‐methylethenyl)cyclohex‐3‐ene‐1,2‐diol.
Authors: Ardashov O. V. , Genaev A. M. , Il'ina I. V. , Korchagina D. V. , Volcho K. P. , Salakhutdinov N. F.
Published: May 2011

Nickel hydridoborate, generated in situ from NiCl2 and NaBH4, selectively reduces the exocyclic double bond in title compound (I) furnishing compound (II) in good yield.
ChemInform Abstract: Asterolaurins G‐J, New Xenicane Diterpenoids from the Taiwanese Soft Coral Asterospicularia laurae.
Authors: Lin Yun‐Sheng , Fazary Ahmed Eid , Chen Chung‐Hsiung , Kuo Yao‐Haur , Shen Ya‐Ching
Published: May 2011

isolation and structure elucidation of asterolaurin G (I), H (II), I (III) and J (IV)
ChemInform Abstract: Schiglautone A, a New Tricyclic Triterpenoid with a Unique 6/7/9‐Fused Skeleton from the Stems of Schisandra Glaucescens.
Authors: Meng Fan‐Yu , Sun Jia‐Xiang , Li Xue , Yu Heng‐Yi , Li Shu‐Ming , Ruan Han‐Li
Published: May 2011

Title compound (I) shows weak cytotoxicity against HeLa, Hep G2, and SGC‐7901 cell lines.
ChemInform Abstract: Diels—Alder Reaction as a Synthetic Approach to Bicyclo[3.3.1]nonane Colchicine Analogues.
Authors: Nurieva E. V. , Semenova I. S. , Nuriev V. N. , Shishov D. V. , Baskin I. I. , Zefirova O. N. , Zefirov N. S.
Published: May 2011

The synthesis of the title bicyclononane colchicine analogues by Diels—Alder reactions of appropriate dienophiles with dienes proves to be rather difficult.
ChemInform Abstract: Synthesis of 3′‐Azido‐3′‐deoxythymidine (AZT)—Cinchona Alkaloid Conjugates via Click Chemistry: Toward Novel Fluorescent Markers and Cytostatic Agents.
Authors: Baraniak Dagmara , Kacprzak Karol , Celewicz Lech
Published: May 2011

The copper‐catalyzed Huisgen azide‐alkyne cycloaddition reaction between azidodeoxythymidine (II) and Cinchona alkaloids (I) and (IV), resp., provides two series of conjugates as single products.
ChemInform Abstract: Research Trends in Rare Earths: A Preliminary Analysis
Authors: Adachi Gin‐ya , Imanaka Nobuhito , Tamura Shinji
Published: May 2011

Review: 7 refs.
ChemInform Abstract: Novel Multifunctional Materials Based on Oxide Thin Films and Artificial Heteroepitaxial Multilayers
Authors: Opel Matthias , Gepraegs Stephan , Menzel Edwin P. , Nielsen Andrea , Reisinger Daniel , Nielsen Karl‐Wilhelm , Brandlmaier Andreas , Czeschka Franz D. , Althammer Matthias , Weiler Mathias , et al. et al.
Published: May 2011

Review: 150 refs.
ChemInform Abstract: Vanadium and Molybdenum Peroxides: Synthesis and Catalytic Activity in Oxidation Reactions
Authors: Conte Valeria , Floris Barbara
Published: May 2011

Review: 147 refs.
ChemInform Abstract: Utility of 3‐Amino‐4,6‐dimethyl‐1H‐pyrazolo[3,4‐b]pyridine in Heterocyclic Synthesis
Authors: Gouda Moustafa A.
Published: May 2011

Review: 29 refs.
ChemInform Abstract: Phosphoramidite—Rhodium Complexes as Catalysts for the Asymmetric [2 + 2 + 2] Cycloaddition of Alkenyl Isocyanates and Alkynes
Authors: Friedman Rebecca Keller , Oberg Kevin M. , Dalton Derek M. , Rovis Tomislav
Published: May 2011

Review: 40 refs.
ChemInform Abstract: Carbene Catalysts
Authors: Moore Jennifer L. , Rovis Tomislav
Published: May 2011

Review: 172 refs.
ChemInform Abstract: Asymmetric Hydrogenation of Activated Ketones
Authors: Margitfalvi Jozsef L. , Talas Emilia
Published: May 2011

Review: 499 refs.
ChemInform Abstract: Azide Chemistry in Rotaxane and Catenane Synthesis
Authors: Durot Stephanie , Frey Julien , Sauvage Jean‐Pierre , Tock Christian
Published: May 2011

Review: 97 refs.
ChemInform Abstract: Fluorogenic Copper(I)‐catalyzed Azide—Alkyne Cycloaddition Reactions and Their Applications in Bioconjugation
Authors: Le Droumaguet Celine , Wang Qian
Published: May 2011

Review: 86 refs.
ChemInform Abstract: The Medicinal Potential of Promising Marine Macrolides with Anticancer Activity
Authors: Qi Yunkun , Ma Shutao
Published: May 2011

Review: ca. 150 refs.
ChemInform Abstract: Integrated Bioinorganic Hybrid Systems for Nano‐Forensics
Authors: Oh Jae‐Min , Park Dae‐Hwan , Choy Jin‐Ho
Published: May 2011

Review: 76 refs.
ChemInform Abstract: Cleavage of RNA Phosphodiester Bonds by Small Molecular Entities: A Mechanistic Insight
Authors: Loennberg Harri
Published: May 2011

Review: ca. 150 refs.
ChemInform Abstract: The Effect of pH on the Oxidative Polymerization of Aniline and the Morphology and Properties of Products
Authors: Sapurina I. Yu , Stejskal J.
Published: May 2011

Review: 250 refs.
5′,6′‐Nucleoside Phosphonate Analogues Architecture: Synthesis and Comparative Evaluation towards Metabolic Enzymes
Authors: Gallier Franck , Alexandre Julie A. C. , El Amri Chahrazade , Deville‐Bonne Dominique , Peyrottes Suzanne , Périgaud Christian
Published: May 2011

Nucleoside phosphonates have been designed as stable 5′‐mononucleotide mimics and are nowadays considered a potent class of antiviral agents. Within cells, they must be metabolised to the corresponding diphosphate to exert their biological activity. In this process, the first phosphorylation step, catalysed by nucleoside monophosphate kinases (NMP kinases), has been proposed as a bottleneck. Herein, we report the synthesis of a series of ribonucleoside phosphonate derivatives isosteric to 5′‐mononucleotides, with different degrees of flexibility within the 5′,6′‐CC bond, as well as different polarities, through the introduction of hydroxy groups. The influence of these modifications on the capacity of the compounds to act as substrates for appropriate human NMP kinases, involved in nucleic acids metabolism, has been investigated. Low flexibility, as well as an absence of hydroxy groups within the ribose–phosphorus architecture, is critical for efficient phosphotransfer. Among the series of pyrimidine analogues, one derivative was shown to be phosphorylated by human UMP‐CMP kinase, with rates similar to those of dUMP and even better than dCMP.
Aggregation of 2‐Aminobenzimidazole—A Combined Experimental and Theoretical Investigation
Authors: Angelova Silvia E. , Spassova Milena I. , Deneva Vera V. , Rogojerov Marin I. , Antonov Liudmil M.
Published: May 2011

An investigation of 2‐aminobenzimidazole was carried out by calculations at HF, MP2, and DFT levels of theory and also by UV and IR spectroscopy. The quantum chemical calculations predict a full shift of the equilibrium towards the amino form, but the absorption spectra in different solvents distinctly show a two‐component equilibrium system. Examination of possible equilibria in solution shows that an equilibrium between two dimeric forms of the amino tautomer of 2‐aminobenzimidazole explains the spectral observations.