bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reductively Dissociable siRNA‐Polymer Hybrid Nanogels for Efficient Targeted Gene Silencing
Authors: Hong Cheol Am , Kim Jee Seon , Lee Soo Hyeon , Kong Won Ho , Park Tae Gwan , Mok Hyejung , Nam Yoon Sung 
Published: August 2012

AbstractA highly efficient approach for target‐specific gene silencing based on a reductively dissociable nanogel incorporating small interfering RNA (siRNA) crosslinked with linear polyethylenimine (LPEI) via disulfide bonds is presented. Thiol‐terminated siRNA at both 3′‐ends is electrostatically complexed with thiol‐grafted LPEI. The prepared siRNA/LPEI complex contains inter‐ and intramolecular linkages, generating a mutually crosslinked siRNA/LPEI nanogel (MCN) that exhibits excellent structural stability against the addition of heparin but is readily disintegrated to biologically active, monomeric siRNA upon exposure to reductive conditions. Accordingly, the highly condensed, stable MCN shows greatly enhanced cellular uptake and gene silencing efficiency compared to the siRNA/LPEI complexes without crosslinks or with only LPEI‐mediated crosslinks.
A General Approach to Substituted Benzimidazoles and Benzoxazoles via Heterogeneous Palladium‐Catalyzed Hydrogen‐Transfer with Primary Amines
Authors: Pizzetti Marianna , De Luca Elisa , Petricci Elena , Porcheddu Andrea , Taddei Maurizio 
Published: August 2012

AbstractThe synthesis of benzimidazoles starting from o‐phenylenediamines and amines in the presence of palladium on charcoal as catalyst is reported. Under microwave dielectric heating it is possible to use a tertiary, a secondary, and even a primary amine as the substrate for a palladium‐mediated process to get 2‐substituted or 1,2‐disubstituted benzimidazoles, depending on the nature of the o‐phenylenediamine employed. Primary amines are the most suitable reagents for the atom economy of the overall process that resulted to be general as several different substituted benzimidazoles were obtained in good yield. Benzoxazoles can be also prepared starting from primary amines and o‐aminophenol. The reaction is also highly selective as no (poly)‐alkylated phenylenediamines or cross‐contaminated benzimidazoles are obtained starting from N‐monoalkylphenylenediamines. This behavior was interpreted as a scarce aptitude to dehydrogenation of the methylene bonded to the aromatic NH of N‐alkylarylamines. The experiments carried out consent to draw an almost complete picture of the reaction pathways occurring during the process. The catalyst can be recycled several times and, although far from optimal performances, catalyst TON=90 is encouraging for further large‐scale optimization protocols. In addition, the palladium on charcoal‐catalyzed microwave‐assisted reaction of o‐phenylenediamine gives de‐alkylation of tertiary amines and transformation into the secondary ones.
Reversible Alkylation of Dimedone with Aldehyde: A Neglected Way for Maximizing Selectivity of Three‐Component Reactions of Dimedone and an Aldehyde
Authors: Li Minghao , Gu Yanlong 
Published: August 2012

AbstractThe selectivity of a three‐component electrophilic reaction of an aldehyde with dimedone and another carbon‐based nucleophile could be improved by a reversible alkylation procedure, which involves formation, breaking and regeneration of CC bonds. In the presence of iron(III) chloride and triphenylphosphine, an analogous CC bond breaking can be observed in the reaction of 2,3,4,9‐tetrahydro‐9‐(2‐hydroxy‐4,4‐dimethyl‐6‐oxo‐1‐cyclohexen‐1‐yl)‐3,3‐dimethyl‐1H‐xanthen‐1‐one, in which the fragment of dimedone was replaced by a carbon‐based nucleophile. Inspired by this observation, some three‐component reactions of salicyldehyde and dimedone were successfully developed by using iron(III) chloride and triphenylphosphine (PPh3) as catalyst. PPh3 plays the role of hydrogen bond acceptor, which confers a good flexibility of the substrate by weakening the intramolecular hydrogen bond, allowing thus an easy interaction of the substrate with iron(III) chloride catalyst.
Palladium‐Catalyzed and Hybrid Acids‐Assisted Synthesis of [60]Fulleroazepines in One Pot under Mild Conditions: Annulation of N‐Sulfonyl‐2‐aminobiaryls with [60]Fullerene through Sequential C‐H Bond Activation, C‐C and C‐N Bond Formation
Authors: Rajeshkumar Venkatachalam , Chan Fu‐Wei , Chuang Shih‐Ching 
Published: August 2012

AbstractAn extraordinarily efficient hybrid acids‐assisted, palladium‐catalyzed and chelating‐group‐assisted CH bond activation of N‐sulfonyl‐2‐aminobiaryls and their annulations with [60]fullerene via sequential CC and CN bond formation at room temperature to afford [60]fulleroazepines is demonstrated. The formation of [60]fulleroazepines is highly regioselective and tolerant to both electron‐withdrawing and electron‐donating groups on the aryl moiety and the reaction gives monofunctionalized fullerenes in good yields (up to 54% isolated yield and 92% based on converted C60).
Functionalization of wool fabric with phase‐change materials microcapsules after plasma surface modification
Authors: Oliveira Fernando Ribeiro , Fernandes Marta , Carneiro Noémia , Pedro Souto António 
Published: August 2012

AbstractThe use of microcapsules has increased in several different areas, namely, textile applications. They have been used as a possible means of introducing new properties, namely, in medical care by antibiotics, skin moisturizers, and other drugs and for thermal comfort. In this study, we examined the influence of dielectric barrier discharge (DBD) plasma treatment on the adhesion of phase‐change material (PCM) microcapsules on wool fabric. Several experimental techniques were used to evaluate the wool surface modification after plasma treatment and the influence of the microcapsules' resistance to washing conditions, namely, the determination of the static and dynamic contact angles, surface energy, and adhesion work; X‐ray photoelectron spectroscopy; Fourier transform infrared spectroscopy; differential scanning calorimetry; and scanning electron microscopy. Chemical and physical characterization of the wool fiber in the fabric confirmed significant surface modification. The plasma treatment greatly increased the hydrophilicity, surface energy, and adhesion work of the wool fabric; this proved that more microcapsules were adsorbed on the fabric and more microcapsules remained on the fabric surface after the washing procedures. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Preparation, structure, and properties of chitosan/cellulose/multiwalled carbon nanotube composite membranes and fibers
Authors: Xiao Wenjun , Wu Tinghua , Peng Jiajian , Bai Ying , Li Jiayun , Lai Guoqiao , Wu Ying , Dai Lizong 
Published: August 2012

AbstractBinary ionic liquids (ILs), 1‐butyl‐3‐methylimidazolium chloride and 1‐H‐3‐methylimidazolium chloride, were developed to dissolve chitosan and cellulose and disperse multiwalled carbon nanotubes (MWCNTs). The resulting mixed paste could be used to prepare chitosan/cellulose/MWCNT composite membranes and fibers. Fourier transform infrared spectroscopy, wide‐angle X‐ray diffraction, thermogravimetric analysis, scanning electron microscopy, tensile testing, and conductivity measurements were used to evaluate the structure and properties of the composite materials and the effect of the incorporation of MWCNTs at various loadings. The characterization results indicate that the incorporation of MWCNTs improved the comprehensive performances of the composite materials, and the best loading of MWCNTs was 4 wt %. This IL dissolution method is a green and feasible method for preparing chitosan/cellulose/MWCNT composite membranes and fibers and will provide beneficial references for the preparation of similar materials. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Effects of low frequency electromagnetic field on proliferation of human epidermal stem cells: An in vitro study
Authors: Zhang Mingsheng , Li Xinping , Bai Liming , Uchida Kenzo , Bai Wenfang , Wu Bo , Xu Weicheng , Zhu Hongxiang , Huang Hong 
Published: August 2012

AbstractTo investigate the effects of low frequency electromagnetic fields (EMF) on the proliferation of epidermal stem cells, human epidermal stem cells (hESC) were isolated, expanded ex vivo, and then exposed to a low frequency EMF. The test and control cells were placed under the same environment. The test cells were exposed for 30 min/day to a 5 mT low frequency EMF at 1, 10, and 50 Hz for 3, 5, or 7 days. The effects of low frequency EMF on cell proliferation, cell cycle, and cell‐surface antigen phenotype were investigated. Low frequency EMF significantly enhanced the proliferation of hESC in the culture medium in a frequency‐dependent manner, with the highest cell proliferation rate at 50 Hz (P < 0.05). Exposure to a low frequency EMF significantly increased the percentage of cells at the S phase of the cell cycle, coupled with a decrease in the percentage of cells in the G1 phase (P < 0.05) but the effect was not frequency dependent. The percentage of CD29+/CD71− cells remained unchanged in the low frequency EMF‐exposed hESC. The results suggested that low frequency EMF influenced hESC proliferation in vitro, and this effect was related to the increased proportion of cells at the S phase. Bioelectromagnetics 34:74–80, 2013. © 2012 Wiley Periodicals, Inc.
Whole chromosome aneuploidy: Big mutations drive adaptation by phenotypic leap
Authors: Chen Guangbo , Rubinstein Boris , Li Rong 
Published: August 2012

AbstractDespite its widespread existence, the adaptive role of aneuploidy (the abnormal state of having an unequal number of different chromosomes) has been a subject of debate. Cellular aneuploidy has been associated with enhanced resistance to stress, whereas on the organismal level it is detrimental to multicellular species. Certain aneuploid karyotypes are deleterious for specific environments, but karyotype diversity in a population potentiates adaptive evolution. To reconcile these paradoxical observations, this review distinguishes the role of aneuploidy in cellular versus organismal evolution. Further, it proposes a population genetics perspective to examine the behavior of aneuploidy on a populational versus individual level. By altering the copy number of a significant portion of the genome, aneuploidy introduces large phenotypic leaps that enable small cell populations to explore a wide phenotypic landscape, from which adaptive traits can be selected. The production of chromosome number variation can be further increased by stress‐ or mutation‐induced chromosomal instability, fueling rapid cellular adaptation.
On the cause of aging and control of lifespan
Authors: Gladyshev Vadim N. 
Published: August 2012

AbstractWhat the causes of aging are and which factors define lifespan are key questions in the understanding of aging. Here, it is argued that cellular life involves (i) inevitable accumulation of damage resulting from imperfectness and heterogeneity of every cellular process, and (ii) dilution of damage when cells divide. While severe damage is cleared by protective systems, milder damage can only be diluted. This is due to the high cost of accuracy, the greater number of damage forms compared to protective systems, and the constraints on cellular life inherited from the prokaryotic world. This strategy also applies to cancer cells, which are particularly dependent on damage dilution. Imposing restriction on cell division necessarily leads to aging. Interventions that extend lifespan act through metabolic reprogramming, thereby changing both damage composition and the rate of damage accumulation. Thus, heterogeneity leading to myriad mild damage forms represents the cause of aging, whereas the processes that affect the damage landscape and damage accumulation are lifespan regulators.
Review of reactive kinetic models describing reductive dechlorination of chlorinated ethenes in soil and groundwater
Authors: Chambon Julie C. , Bjerg Poul L. , Scheutz Charlotte , Bælum Jacob , Jakobsen Rasmus , Binning Philip J. 
Published: August 2012

AbstractReductive dechlorination is a major degradation pathway of chlorinated ethenes in anaerobic subsurface environments, and reactive kinetic models describing the degradation process are needed in fate and transport models of these contaminants. However, reductive dechlorination is a complex biological process, where many microbial populations including dechlorinating, fermentative, methanogenic, iron and sulfate reducing, interact. In this article the modeling approaches and the experimental data needed to calibrate them are reviewed, classified, and discussed. Model approaches considered include first order kinetics, Monod kinetics to describe sequential reductive dechlorination and bacterial growth, and metabolic models which simulate fermentation and redox processes interacting with reductive dechlorination processes. The review shows that the estimated kinetic parameters reported vary over a wide range, and that experimental microbial data are scarce. Very few studies have been performed evaluating the influence of sulfate and iron reduction, and contradictory conclusions on the interaction of redox processes with reductive dechlorination have been reported. The modeling approaches for metabolic reductive dechlorination employing different descriptions of the interaction between redox and dechlorination processes and competition for hydrogen are classified. The current concepts lead to different results, suggesting a need for further investigations on the interactions between the microbial communities performing dechlorination and redox processes, including the establishment of biomarkers quantifying dechlorination, and on geochemical characterization. Finally, the relevance of laboratory data and the development of practical modeling tools for field applications are discussed. Biotechnol. Bioeng. 2013; 110: 1–23. © 2012 Wiley Periodicals, Inc.
Alteration of synergistic muscle activity following neuromuscular electrical stimulation of one muscle
Authors: Stutzig Norman , Siebert Tobias , Granacher Urs , Blickhan Reinhard 
Published: August 2012

AbstractThe aim of the study was to determine muscle activation of the m. triceps surae during maximal voluntary contractions (MVCs) following neuromuscular electrical stimulation (NMES) of the m. gastrocnemius lateralis (GL). The participants (n = 10) performed three MVC during pretest, posttest, and recovery, respectively. Subsequent to the pretest, the GL was stimulated by NMES. During MVC, force and surface electromyography (EMG) of the GL, m. gastrocnemius medialis (GM), and m. soleus (SOL) were measured. NMES of GL induced no significant decline (3%) in force. EMG activity of the GL decreased significantly to 81% (P < 0.05), whereas EMG activity of the synergistic SOL increased to 112% (P < 0.01). The GM (103%, P = 1.00) remained unaltered. Decreased EMG activity in the GL was most likely caused by failure of the electrical propagation at its muscle fiber membrane. The decline of EMG activity in GL was compensated by increased EMG activity of SOL during MVC. It is suggested that these compensatory effects are caused by central contributions induced by NMES.
Thrombin formation and effect of unfractionated heparin during pediatric cardiac catheterization
Authors: Chen Dawei , Långström Satu , Petäjä Jari , Heikinheimo Markku , Pihkala Jaana 
Published: August 2012

ObjectivesTo assess the strength of thrombin formation and determine the effects of unfractionated heparin (UFH) in children during cardiac catheterization.BackgroundUFH reduces the thrombotic risk related to catheterization but the effects of UFH on the coagulation system in children, and proper monitoring of UFH remain unclear.MethodsWe studied 42 patients aged 3–12 years undergoing catheterization. Twenty‐seven received UFH (group A) and 15 patients did not (group B). Anticoagulation was assessed by measurements of plasma prothrombin fragment F1 + 2, thrombin–antithrombin (TAT) complexes, D‐dimer, activated partial thromboplastin time (APTT), anti‐FXa, and prothrombinase‐induced clotting time (PiCT).ResultsMarkers of thrombin generation remained low during catheterization in group A. In group B, both F1 + 2 and TAT had increased significantly (P< 0.05) by the end of the procedure versus baseline and versus respective levels in group A. In group A, 15 min after heparinization, APTT was over 180 sec (in all patients), anti‐FXa 1.4 U/ml (1.1–2.4 U/ml) and PiCT 1.5 U/ml (1.3–2.4 U/ml). Anti‐FXa and PiCT were correlated (R= 0.84,P< 0.0001).ConclusionsThrombin generation was enhanced in patients who did not receive UFH, which may increase the risk of thrombotic complications. In group A, routine heparinization seemed excessive by all monitoring methods. UFH prevented an increase in prothrombin to thrombin conversion, resulting in unaltered fibrin formation. The current UFH protocol seemed to have no effect on postprocedural activation of coagulation. Further studies are needed to clarify adequate heparin dosing for children during cardiac catheterization to prevent thrombotic complications without predisposing the patient to bleeding complications. © 2012 Wiley Periodicals, Inc.
ChemInform Abstract: New Crystal Structure: Synthesis and Characterization of Hexagonal Wurtzite MnO.
Authors: Nam Ki Min , Kim Yong‐Il , Jo Younghun , Lee Seung Mi , Kim Bog G. , Choi Ran , Choi Sang‐Il , Song Hyunjoon , Park Joon T. 
Published: August 2012

AbstractHexagonal wurtzite MnO is prepared by thermal decomposition of Mn(acac)2 in benzylamine on a carbon template (Ar, 180 °C, 3 h).
ChemInform Abstract: Photo‐to‐Current Response of Bi2Fe4O9 Nanocrystals Synthesized Through a Chemical Co‐Precipitation Process.
Authors: Li Yongping , Zhang Yongcheng , Ye Wanneng , Yu Jianqiang , Lu Chaojing , Xia Linhua 
Published: August 2012

AbstractBi2Fe4O9 nanocrystals are precipitated from a HNO3 solution of Bi(NO3)3 and Fe(NO3)3 by addition of aqueous NaOH solution up to a pH value of 12 at room temperature.
ChemInform Abstract: Assembly of Saturated Nb/W Mixed‐Addendum Polyoxometalate [P2W15Nb3O62]9‐ and Lanthanide Ions (Ln: Eu, Ce).
Authors: Li Cong‐Cong , Liu Shu‐Xia , Li Shu‐Jun , Yang Yuan , Jin Hai‐Yan , Ma Feng‐Ji 
Published: August 2012

AbstractThe title compounds are characterized by single crystal XRD, IR and photoluminescence spectroscopy, and electrochemical measurements.
ChemInform Abstract: Catalytic Asymmetric Monofluorination of α‐Keto Esters: Synthesis of Optically Active β‐Fluoro‐α‐hydroxy and β‐Fluoro‐α‐amino Acid Derivatives.
Authors: Suzuki Shoko , Kitamura Yuki , Lectard Sylvain , Hamashima Yoshitaka , Sodeoka Mikiko 
Published: August 2012

AbstractThe monofluorination is achieved in the presence of (R)‐SEGPHOS‐derived palladium μ‐hydroxo complex (I).
ChemInform Abstract: Radical Mechanism in the Elimination of 2‐Arylsulfinyl Esters.
Authors: Latorre Antonio , Lopez Irakusne , Ramirez Victoria , Rodriguez Santiago , Izquierdo Javier , Gonzalez Florenci V. , Vicent Cristian 
Published: August 2012

AbstractBased on electrospray ionization mass spectrometry and trapping experiments, it is found that the dehydrosulfenylation of 2‐arylsulfinyl esters proceeds via a radical mechanism.
ChemInform Abstract: Orthoamides and Iminium Salts. Part 76. A Further Contribution to the Chemistry of Trialkoxyacetonitriles.
Authors: Kantlehner Willi , Vettel Markus , Eppinger Bernhard 
Published: August 2012

AbstractTrimethoxyacetonitrile (III) is used as a trap for a variety of carbanions.
ChemInform Abstract: A Concise Access to (Polyfluoroaryl)allenes by Cu‐Catalyzed Direct Coupling with Propargyl Phosphates.
Authors: Nakatani Akihiro , Hirano Koji , Satoh Tetsuya , Miura Masahiro 
Published: August 2012

AbstractThe nature of the propargyl phosphate substituents influences the reaction outcome (efficiency and regioselectivity).
ChemInform Abstract: Hiyama Coupling Reaction of Fluorous Alkenyl‐fluorosilanes: Scope and Mechanistic Considerations.
Authors: Rabai Jozsef , Csapo Agnes , Bodor Andrea 
Published: August 2012

AbstractNovel fluorous alkenyl‐fluorosilanes (V) are synthesized by a three‐step procedure and subjected to a Hiyama coupling reaction with iodobenzene to provide the appropriate ω‐perfluoroalkyl‐styrenes.
ChemInform Abstract: A New Family of Cinchona‐Derived Bifunctional Asymmetric Phase‐Transfer Catalysts: Application to the Enantio‐ and Diastereoselective Nitro‐Mannich Reaction of Amidosulfones.
Authors: Johnson Kayli M. , Rattley Matt S. , Sladojevich Filippo , Barber David M. , Nunez Marta G. , Goldys Anna M. , Dixon Darren J. 
Published: August 2012

AbstractSome new cinchona alkaloid derivatives are prepared and tested as catalysts.
ChemInform Abstract: N‐(tert‐Butoxycarbonyl)‐N‐[(triethylenediammonium)sulfonyl]azanide: A Convenient Sulfamoylation Reagent for Alcohols.
Authors: Armitage Ian , Berne Alexander M. , Elliott Eric L. , Fu Mingkun , Hicks Frederick , McCubbin Quentin , Zhu Lei 
Published: August 2012

AbstractThe title reagent reacts with primary and secondary alcohols and phenols to afford sulfamates.
ChemInform Abstract: An Efficient, Expeditious, and Diastereoselective One‐Pot Pseudo‐Five‐Component Reaction for the Synthesis of New Bis‐Betti Bases under Catalyst‐Free Conditions.
Authors: Shafiee Mehdi , Khosropour Ahmad R. , Mohammadpoor‐Baltork Iraj , Moghadam Majid , Tangestaninejad Shahram , Mirkhani Valiollah 
Published: August 2012

AbstractThe synthesis of title compounds from different dihydrooxynaphthalenes, aromatic aldehydes, and 2‐amino‐5‐methylisoaxzole is studied.
ChemInform Abstract: Intramolecular Oxycyanation of Alkenes by Cooperative Pd/BPh3 Catalysis.
Authors: Koester Dennis C. , Kobayashi Masato , Werz Daniel B. , Nakao Yoshiaki 
Published: August 2012

AbstractAlkenyl(cyanato)benzenes undergo the title reaction to give benzofuran‐ and benzopyran derivatives in a highly chemo‐ and regioselective manner.
ChemInform Abstract: DABCO‐Promoted Efficient and Convenient Synthesis of Benzofurans.
Authors: Meshram H. M. , Reddy B. Chennakesava , Prasad B. R. V. , Goud P. Ramesh , Kumar G. Santosh , Kumar R. Naveen 
Published: August 2012

AbstractDABCO‐catalyzed reaction of phenacyl halides and salicylaldehyde derivatives provides an efficient access towards 2‐acylbenzofurans (III).
ChemInform Abstract: Facile Synthesis of 2,3‐Disubstituted Pyrroles from 2‐Substituted 1‐Pyrrolines.
Authors: Fujiwara Yurie , Oda Mitsunori , Shoji Taku , Abe Takako , Kuroda Shigeyasu 
Published: August 2012

AbstractPyrrolines (I) react with arylaldehyde acetals (II) in the presence of a Lewis acid and base to give arylmethylidene pyrrolines (III).
ChemInform Abstract: Silica‐Supported Bismuth(III) Chloride as a New Recyclable Heterogeneous Catalyst for the Paal—Knorr Pyrrole Synthesis.
Authors: Aghapoor Kioumars , Ebadi‐Nia Leila , Mohsenzadeh Farshid , Morad Mina Mohebi , Balavar Yadollah , Darabi Hossein Reza 
Published: August 2012

AbstractThe catalyst system exhibits a remarkable reusable activity and a higher performance compared to homogeneous BiCl3.
ChemInform Abstract: Sulfated Tin Oxide: A Reusable and Highly Efficient Heterogeneous Catalyst for the Synthesis of 2,4,5‐Triaryl‐1H‐imidazole Derivatives.
Authors: Dake Satish A. , Khedkar Mahesh B. , Irmale Ghanshyam S. , Ukalgaonkar Suhas J. , Thorat Vinod V. , Shintre Suhas A. , Pawar Rajendra P. 
Published: August 2012

AbstractA new one‐pot, three‐component condensation reaction of benzil/benzoin, aromatic aldehydes and NH4OAc using sulfated tin oxide as catalyst yields the corresponding title compounds (III) in excellent yields.
ChemInform Abstract: The First Examples of Cycloadditions of 2‐Diazo‐1,3‐dicarbonyl Compounds to Aromatic Thioketones.
Authors: Nikolaev Valerij A. , Ivanov Alexey V. , Shakhmin Anton A. , Sieler Joachim , Rodina Ludmilla L. 
Published: August 2012

AbstractAcyclic 2‐diazo‐1,3‐dicarbonyl compounds undergo a multistep cascade process to give oxathioles (III).