bluuebunny/crossref_metadata_2025_split huggingface dataset:
Short‐chain ester synthesis by transesterification employing poly (MAc‐co‐DMA‐cl‐MBAm) hydrogel‐bound lipase of Bacillus coagulans MTCC‐6375
Authors: Kanwar Shamsher Singh , Sharma Chanderkant , Verma Madan Lal , Chauhan Sandeep , Chimni Swapandeep Singh , Chauhan Ghansham Singh 
Published: April 2008

AbstractLipases (E.C. 3.1.1.3) have been extensively used to achieve various esterification reactions in water‐restricted or water‐free media. In the present study a purified thermotolerant alkalophilic extracellular lipase of Bacillus coagulans MTCC‐6375 has been efficiently immobilized onto a synthetic poly (MAc‐co‐DMA‐cl‐MBAm) hydrogel by surface absorption, and the bound lipase was used to perform short‐chain fatty acid ester synthesis in n‐alkane(s). The hydrogel bound lipase resulted in approximately 67 mM of isoamyl acetate at 55°C in n‐heptane under shaking in 15 h when vinyl acetate:isoamyl alcohol was used in a ratio of 100 mM:100 mM. Addition of a molecular sieve (3 Å × 1.5 mm) to the reaction system at a concentration of 25–500 mg per reaction volume had deleterious effect on the conversion of reactants to isoamyl acetate (64 mM). During the repetitive esterification under optimal conditions, the hydrogel bound lipase produced 31.3 mM of ester after fourth cycle of reuse. Use of methanol and 2‐propanol (instead of isoamyl alcohol) resulted in 78.2 and 64.9 mM of methyl acetate and 2‐propyl acetate, respectively, under the optimized conditions in n‐heptane © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Effects of blend composition and dynamic vulcanization on the morphology and dynamic viscoelastic properties of PP/EPDM blends
Authors: Prut E.V. , Erina N.A. , Karger‐Kocsis J. , Medintseva T.I. 
Published: April 2008

AbstractThe morphology and dynamic viscoelastic properties of isotactic polypropylene (PP) blended with oil‐free/oil‐extended ethylene–propylene–diene (EPDM) rubbers were studied. Unvulcanized and dynamically vulcanized blends with the compositions PP/EPDM = 50/50 and = 30/70 were investigated. The morphology was observed by phase contrasted atomic force microscopy. The dynamic viscoelastic properties were determined with a rheometer of plate–plate configuration. It was shown that the rheological behavior was strongly affected by both the composition and the morphology of the blends. Significant improvement in the flowability of the dynamically vulcanized blends was observed when oil‐extended EPDM was used instead of the oil‐free version. It was demonstrated that the rheological properties are mostly controlled by the elastomer phase at low frequencies, while in the high‐frequency range the influence of PP becomes dominant. The peculiarities in the rheological behavior of the thermoplastic elastomers (uncured blends, TPE) and thermoplastic dynamic vulcanizates (TPV, dynamically cured blends) containing oil‐extended EPDMs were traced to a limited compatibility between the PP and EPDM components in the melt. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Preparation of highly crosslinked monodisperse poly(styrene‐co‐divinylbenzene) microspheres by two‐stage dispersion polymerization
Authors: Cao Moli , Tong Bin , Shen Jinbo , Dong Yuping , Zhi Junge 
Published: April 2008

AbstractMonodisperse poly(styrene‐co‐divinylbenzene) microspheres crosslinked with different concentrations of divinylbenzene were synthesized by two‐stage dispersion polymerization in ethanol dispersion medium with poly(N‐vinyl pyrrolidone) as a stabilizer and 2,2′‐azobisisobutyronitrile as a radical initiator. The microsphere size, size distribution, surface morphology, and structure were characterized by a particle analyzer, a scanning microscope and IR spectroscopy. The effect of the adding time, the adding rate, and the concentration of crosslinker on the size, size distribution, and shape of the resulting particles were also investigated. Highly crosslinked monodisperse microspheres with diameters from 2 to 4 μm were obtained. The SEM characterization showed that the resulting microspheres had spherical shapes with smooth surfaces. The obtained microspheres have good resistance to solvent whether at ambient or heating temperatures and are thermally stable. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Studies on new type of phenolic resin—Curing reaction of bisphenol‐A‐based benzoxazine with epoxy resin using latent curing agent and the properties of the cured resin
Authors: Kimura Hajime , Matsumoto Akihiro , Ohtsuka Keiko 
Published: April 2008

AbstractCuring reaction of bisphenol‐A‐based benzoxazine (Ba) with epoxy resin (Ep) using latent curing agent, and the properties of the cured resin were investigated. Consequently, by using latent curing agent, the ring opening reaction of benzoxazine ring occurred more rapidly, and then also the phenolic hydoroxyl group generated by the ring opening reaction of benzoxazine ring reacted with epoxy ring more rapidly. And it was found that the cure time of the molten resins from Ba and Ep with latent curing agent could be reduced and also the cure temperature could be lowered, compared with those from Ba and Ep without latent curing agent. The melt viscosity of the molten resins from Ba and Ep with latent curing agent was kept about 50 [Pa s] at 100°C even after 30 min, the molten resins from Ba and Ep with latent curing agent showed good thermal stability below 100°C. However, above 170°C the curing reaction of Ba with Ep with latent curing agent proceeded rapidly. The cured resin from Ba and Ep with latent curing agent showed good heat resistance, flame resistance, mechanical properties, and electrical insulation, compared with the cured resin from Ba and Ep without latent curing agent. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Exploratory study on seaweed as novel filler in polypropylene composite
Authors: Hassan M. Masudul , Mueller Marco , Wagners Manfred H. 
Published: April 2008

AbstractSeaweed (SW) is employed as filler to prepare composites on the basis of a polypropylene (PP) matrix in the ratio of 10 : 90, 20 : 80, 30 : 70, 40 : 60, and 50 : 50 (wt % SW : wt % PP) by compounding and injection molding. The tensile, bending and impact properties of the composites were investigated. The 30% SW : 70% PP composite showed the best over‐all mechanical performance of the composites prepared. Further improvement of this optimal composite was achieved by incorporating 2% thermoplastic elastomer (TPE) as additive. Interfacial adhesion and bonding between the fibers and PP matrix were investigated by scanning electron microscopy (SEM). Water absorption tests of the different composites were also performed, and addition of TPE was found to lead to a substantial reduction of water uptake. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Microstructure and thermal properties of silyl‐terminated polycaprolactone–polysiloxane modified epoxy resin composites
Authors: Liu Pinggui , He Lihua , Song Jiangxuan , Liang Xingquan , Ding Heyan 
Published: April 2008

AbstractWith a direct nucleophilic addition between OH groups of polydiol and NCO of a silane, a blend of silyl‐terminated polycaprolactone PCL‐Si and silyl‐terminated polydimethylsiloxane PDMS‐Si oligomer, PCS‐2Si, were firstly prepared, and then blended with a commercial epoxy resin (diglycidyl ether of bisphenol‐A, DGEBA) to form a ternary composite. The formed ternary composites of different content of DGEBA were cured using a polyamidoamine as a curing agent and a sol–gel process at ambient temperature. The microstructures and properties of the cured composites were investigated by SEM, TGA, and energy dispersive spectroscopy. The results showed the compatibility between DGEBA and PDMS increased with increasing content of PCS‐2Si, but higher content of PCS‐2Si resulted in a slight enrichment of silicon in the surface of the cured film. TGA showed that incorporating PCS‐2Si into epoxy resin altered the composites' thermal stability and degradation characteristics. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Carbon–Nitrogen Bond‐Forming Reactions of Dialkyl Azodicarboxylate: A Promising Synthetic Strategy
Authors: Nair Vijay , Biju A. T. , Mathew Smitha C. , Babu Beneesh Pattoorpadi 
Published: April 2008

AbstractAzodicarboxylates have found applications in electrophilic amination reactions and in pericyclic reactions. The nucleophilic trigger in Mitsunobu reactions, that is, the zwitterion formed from triphenylphosphine and dialkyl azodicarboxylate, has been utilized recently in various heterocyclic constructions. This Focus Review summarizes the potential utility of azodicarboxylates in various carbon–nitrogen bond‐forming reactions.
Schlagregensicherheit von Steildachkonstruktionen – europäische und nationale Bewertungsverfahren für den Regeneintrag in gedeckte Dächer und die Schlagregensicherheit von Unterdeck‐ und Unterspannbahnen
Authors: Fechner Otto , Vogdt Frank U. 
Published: April 2008

AbstractSchlagregensicherheit ist die Eigenschaft eines Außenbauteils, bei vorgegebener Windstärke, Regenmenge und Beanspruchungsdauer Schutz gegen das Eindringen von Wasser in das Innere des Bauteils bzw. des Gebäudes zu bieten. Auf Grundlage von genormten Prüfungen werden bereits Bauteile wie Fenster, Außentüren und Tore im Hinblick auf die Schlagregensicherheit beurteilt und klassifiziert. Dagegen sind bislang keine Prüfmethoden zur Beurteilung der Schlagregensicherheit von gedeckten Steildachkonstruktionen geregelt. Dies betrifft sowohl die aus kleinformatigen Dacheindeckungselementen gebildete Dacheindeckung als auch Unterdeck‐ und Unterspannbahnen, die während der Bauphase bei Neu‐ und Umbauten der Witterung ungeschützt ausgesetzt sind. Aus diesem Grunde wurden in den letzten Jahren große Anstrengungen unternommen, um auch die Schlagregensicherheit von gedeckten Steildachkonstruktionen und ungeschützt beregneten Unterdeck‐ und Unterspannbahnen – die als “Behelfsdeckung” dienen sollen – vergleichend beurteilen zu können.
Zur Berechnung der klimatisch bedingten Temperaturbeanspruchungen von Außenwandbekleidungen
Authors: Fouad Nabil A. , Richter Torsten 
Published: April 2008

AbstractAußenwandkonstruktionen werden durch die ständig veränderlichen klimatischen Randbedingungen maßgeblich thermischbeansprucht. Durch diese instationären nichtlinearen Temperaturbeanspruchungen können Schäden bis hin zu Standsicherheitsproblemen entstehen. In diesem Beitrag wird anhand eines Beispiels einer Außenwandkonstruktion beschrieben, welche physikalischen Grundlagen und Annahmen für eine instationäre Temperaturfeldberechnung anzusetzen sind und wie eine praxisnahe Berechnung durchgeführt werden kann.
Enhancement of transient gene expression and culture viability using Chinese hamster ovary cells overexpressing Bcl‐xL
Authors: Majors Brian S. , Betenbaugh Michael J. , Pederson Nels E. , Chiang Gisela G. 
Published: April 2008

AbstractTransient gene expression (TGE) provides a method for quickly delivering protein for research using mammalian cells. While high levels of recombinant proteins have been produced in TGE experiments in HEK 293 cells, TGE efforts in the commercially prominent CHO cell line still suffer from inadequate protein yields. Here, we describe a cell‐engineering strategy to improve transient production of proteins using CHO cells. CHO‐DG44 cells were engineered to overexpress the anti‐apoptotic protein Bcl‐xL and transiently transfected using polyethylenimine (PEI) in serum‐free media. Pools and cell lines stably expressing Bcl‐xL showed enhanced viable cell density and increased production of a glycosylated, therapeutic fusion protein in shake flask TGE studies. The improved cell lines showed fusion protein production levels ranging from 12.6 to 27.0 mg/L in the supernatant compared to the control cultures which produced 6.3–7.3 mg/L, representing a 70–270% increase in yield after 14 days of fed‐batch culture. All Bcl‐xL‐expressing cell lines also exhibited an increase in specific productivity during the first 8 days of culture. In addition to increased production, Bcl‐xL cell lines maintained viabilities above 90% and less apoptosis compared to the DG44 host which had viabilities below 60% after 14 days. Product quality was comparable between a Bcl‐xL‐engineered cell line and the CHO host. The work presented here provides the foundation for using anti‐apoptosis engineered CHO cell lines for increased production of therapeutic proteins in TGE applications. Biotechnol. Bioeng. 2008;101: 567–578. © 2008 Wiley Periodicals, Inc.
Glycation improves the thermostability of trypsin and chymotrypsin
Authors: Pham Van Thong , Ewing Erin , Kaplan Harvey , Choma Christin , Hefford Mary Alice 
Published: April 2008

AbstractA novel glycation procedure, in vacuo glycation, was used to attach glucose covalently to the lysine residues of trypsin and chymotrypsin. Glycated trypsin and glycated chymotrypsin have greatly increased thermostability compared to the native enzymes. For example, glycated bovine trypsin, incubated at 50°C and pH 8.0 for 3 h, retained more than 50% of its original activity whereas the native enzyme was inactivated under the same conditions. Similarly, after incubation at 50°C and pH 8.0, glycated bovine chymotrypsin retained 45% of its original activity and the native enzyme was inactivated. Glycated porcine trypsin is exceptionally thermostable and could be used to digest native ribonuclease at 70°C without the need for prior denaturation. The apparent increase in the thermal stability of the glycated proteins observed in activity measurements is also reflected by an increase in the Tm values determined with differential scanning calorimetry (DSC) and circular dichroism (CD). The glycation does not alter the activity or specificity of these enzymes. Biotechnol. Bioeng. 2008;101: 452–459. © 2008 Wiley Periodicals, Inc.
Comparison of microbial community composition and activity in sulfate‐reducing batch systems remediating mine drainage
Authors: Pereyra L.P. , Hiibel S.R. , Pruden A. , Reardon K.F. 
Published: April 2008

AbstractFive microbial inocula were evaluated in batch tests for the ability to remediate mine drainage (MD). Dairy manure (DM), anaerobic digester sludge, substrate from the Luttrell (LUTR) and Peerless Jenny King (PJK) sulfate‐reducing permeable reactive zones (SR‐PRZs) and material from an MD‐treatment column that had been inoculated with material from a previous MD‐treatment column were compared in terms of sulfate and metal removal and pH neutralization. The microbial communities were characterized at 0, 2, 4, 9, and 14 weeks using denaturing gradient gel electrophoresis and quantitative polymerase chain reaction to quantify all bacteria and the sulfate‐reducing bacteria of the genus Desulfovibrio. The cultures inoculated with the LUTR, PJK, and DM materials demonstrated significantly higher rates of sulfate and metal removal, and contained all the microorganisms associated with the desired functions of SR‐PRZs (i.e., polysaccharide degradation, fermentation, and sulfate reduction) as well as a relatively high proportion of Desulfovibrio spp. These results demonstrate that inoculum influences performance and also provide insights into key aspects of inoculum composition that impact performance. This is the first systematic biomolecular examination of the relationship between microbial community composition and MD remediation capabilities. Biotechnol. Bioeng. 2008;101: 702–713. © 2008 Wiley Periodicals, Inc.
Cloning, expression, and characterization of novel thermostable family 7 cellobiohydrolases
Authors: Voutilainen Sanni P. , Puranen Terhi , Siika‐aho Matti , Lappalainen Arja , Alapuranen Marika , Kallio Jarno , Hooman Satu , Viikari Liisa , Vehmaanperä Jari , Koivula Anu 
Published: April 2008

AbstractAs part of the effort to find better cellulases for bioethanol production processes, we were looking for novel GH‐7 family cellobiohydrolases, which would be particularly active on insoluble polymeric substrates and participate in the rate‐limiting step in the hydrolysis of cellulose. The enzymatic properties were studied and are reported here for family 7 cellobiohydrolases from the thermophilic fungi Acremonium thermophilum, Thermoascus aurantiacus, and Chaetomium thermophilum. The Trichoderma reesei Cel7A enzyme was used as a reference in the experiments. As the native T. aurantiacus Cel7A has no carbohydrate‐binding module (CBM), recombinant proteins having the CBM from either the C. thermophilum Cel7A or the T. reesei Cel7A were also constructed. All these novel acidic cellobiohydrolases were more thermostable (by 4–10°C) and more active (two‐ to fourfold) in hydrolysis of microcrystalline cellulose (Avicel) at 45°C than T. reesei Cel7A. The C. thermophilum Cel7A showed the highest specific activity and temperature optimum when measured on soluble substrates. The most effective enzyme for Avicel hydrolysis at 70°C, however, was the 2‐module version of the T. aurantiacus Cel7A, which was also relatively weakly inhibited by cellobiose. These results are discussed from the structural point of view based on the three‐dimensional homology models of these enzymes. Biotechnol. Bioeng. 2008;101: 515–528. © 2008 Wiley Periodicals, Inc.
The Mildiomycin Biosynthesis: Initial Steps for Sequential Generation of 5‐Hydroxymethylcytidine 5′‐Monophosphate and 5‐Hydroxymethylcytosine in Streptoverticillium rimofaciens ZJU5119
Authors: Li Li , Xu Zhinan , Xu Xiaoying , Wu Jun , Zhang Yun , He Xinyi , Zabriskie T. Mark , Deng Zixin 
Published: April 2008

AbstractMildiomycin (MIL) is a peptidyl nucleoside antibiotic with strong activity against powdery mildew disease of plants. We have cloned the MIL biosynthetic gene cluster in Streptoverticillum rimofaciens ZJU5119 and shown that this organism also produces the related antifungal compound, deshydroxymethyl mildiomycin (dHM‐MIL). A cosmid genomic library was screened for a putative nucleotide hydrolase gene that is related to blsM from the blasticidin S cluster. Six cosmids were identified that contained a 3.5 kb DNA fragment that harbors a homologue of blsM. The sequence of the fragment revealed two open‐reading frames that are likely to function in MIL formation: milA is a CMP hydroxymethylase gene and milB is the homologue of the CMP hydrolase gene blsM. Insertional disruption of milA abolished the production of MIL but not dHM‐MIL, whereas a milB knockout strain did not produce either of the peptidyl nucleosides. Recombinant MilA was produced in E. coli and shown to specifically introduce a C‐5 hydroxymethyl group on CMP, but it did not accept cytosine or dCMP as a substrate. MilB was also expressed and purified from E. coli and shown to efficiently hydrolyze both hydroxymethyl‐CMP (HMCMP) and could accept CMP as an alternative substrate. The ratio of free HMC and cytosine released by MilB was ca. 9:1 in in vitro assays, and is consistent with the higher levels of MIL compared to dHM‐MIL that are produced by Streptoverticillum rimofaciens.
ANGIOCARE: An automated system for fast three‐dimensional coronary reconstruction by integrating angiographic and intracoronary ultrasound data
Authors: Bourantas Christos V. , Kalatzis Fanis G. , Papafaklis Michail I. , Fotiadis Dimitrios I. , Tweddel Ann C. , Kourtis Iraklis C. , Katsouras Christos S. , Michalis Lampros K. 
Published: April 2008

AbstractObjectives:The development of an automated, user‐friendly system (ANGIOCARE), for rapid three‐dimensional (3D) coronary reconstruction, integrating angiographic and, intracoronary ultrasound (ICUS) data.Methods:Biplane angiographic and ICUS sequence images are imported into the system where a prevalidated method is used for coronary reconstruction. This incorporates extraction of the catheter path from two end‐diastolic X‐ray images and detection of regions of interest (lumen, outer vessel wall) in the ICUS sequence by an automated border detection algorithm. The detected borders are placed perpendicular to the catheter path and established algorithms used to estimate their absolute orientation. The resulting 3D object is imported into an advanced visualization module with which the operator can interact, examine plaque distribution (depicted as a color coded map) and assess plaque burden by virtual endoscopy.Results:Data from 19 patients (27 vessels) undergoing biplane angiography and ICUS were examined. The reconstructed vessels were 21.3–80.2 mm long. The mean difference was 0.9 ± 2.9% between the plaque volumes measured using linear 3D ICUS analysis and the volumes, estimated by taking into account the curvature of the vessel. The time required to reconstruct a luminal narrowing of 25 mm was approximately 10 min.Conclusion:The ANGIOCARE system provides rapid coronary reconstruction allowing the operator accurately to estimate the length of the lesion and determine plaque distribution and volume. © 2008 Wiley‐Liss, Inc.
Feasibility of patent foramen ovale closure with no‐device left behind
Authors: Ruiz Carlos E. , Kipshidze Nicholas , Chiam Paul T.L. , Gogorishvili Irakli 
Published: April 2008

AbstractObjectives:This study evaluated the feasibility of percutaneous patent foramen ovale (PFO) closure using a transcatheter suture (Superstitch), leaving no device behind.Background:PFO has been implicated in cryptogenic strokes and migraine with auras. Percutaneous PFO closure, being less invasive than surgical closure, is increasingly performed. There are, however, early and long‐term risks including device embolization, fracture, thrombosis, or infection, erosions into the free atrial wall and aorta, arrhythmias, and death. Furthermore, device implantation may complicate future percutaneous access to the left atrium. Partially reabsorbable devices and tissue welding to close PFO have recently been introduced. The first‐in‐man transcatheter suture closure of a PFO in an 18‐year‐old female with chronic migraine with aura and a well documented stroke is described.Methods:The right femoral vein was cannulated under mild sedation and local anesthesia. Using intracardiac echocardiography imaging, bubble study demonstrated a right‐to‐left shunt through the PFO at rest. A Superstitch device was advanced across the PFO and sutures were delivered through the septum primum and secundum. The sutures were exteriorized and a knot was advanced to the right atrial septum and cut.Results:Bubble study confirmed successful PFO suture closure. Transesophageal and transthoracic echocardiograms with bubble studies at 1 and 2 months, respectively showed complete closure with no right‐to‐left shunt even during Valsalva maneuver. At 6 months, the patient remained free ofsymptoms or migraine episodes.Conclusion:Percutaneous transcatheter suture closure of a PFO can be successfully achieved with no residual shunt and leaving nodevice behind. Technological refinements are required for wider scale use. © 2008 Wiley‐Liss, Inc.
ChemInform Abstract: Hydrogenoxosilicates of the Lanthanides. Part 2. La9OMg[SiO4]6[SiO3(OH)] with cerite‐Like Structure.
Authors: Lipp Christian , Schleid Thomas 
Published: April 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Visualizing the Crystal Structure and Locating the Catalytic Activity of Micro‐ and Mesoporous ZSM‐5 Zeolite Crystals by Using in situ Optical and Fluorescence Microscopy.
Authors: Kox Marianne H. F. , Stavitski Eli , Groen Johan C. , Perez‐Ramirez Javier , Kapteijn Freek , Weckhuysen Bert M. 
Published: April 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.