bluuebunny/crossref_metadata_2025 huggingface dataset:
Folding Dynamics of 10‐Residue β‐Hairpin Peptide Chignolin
Authors: Suenaga Atsushi , Narumi Tetsu , Futatsugi Noriyuki , Yanai Ryoko , Ohno Yousuke , Okimoto Noriaki , Taiji Makoto
Published: April 2007

Short peptides that fold into β‐hairpins are ideal model systems for investigating the mechanism of protein folding because their folding process shows dynamics typical of proteins. We performed folding, unfolding, and refolding molecular dynamics simulations (total of 2.7 μs) of the 10‐residue β‐hairpin peptide chignolin, which is the smallest β‐hairpin structure known to be stable in solution. Our results revealed the folding mechanism of chignolin, which comprises three steps. First, the folding begins with hydrophobic assembly. It brings the main chain together; subsequently, a nascent turn structure is formed. The second step is the conversion of the nascent turn into a tight turn structure along with interconversion of the hydrophobic packing and interstrand hydrogen bonds. Finally, the formation of the hydrogen‐bond network and the complete hydrophobic core as well as the arrangement of side‐chain–side‐chain interactions occur at approximately the same time. This three‐step mechanism appropriately interprets the folding process as involving a combination of previous inconsistent explanations of the folding mechanism of the β‐hairpin, that the first event of the folding is formation of hydrogen bonds and the second is that of the hydrophobic core, or vice versa.
Formal Total Synthesis of (−)‐Apicularen A by a Strategy Based on Ring‐Closing Metathesis and Transannular Cyclization
Authors: Jung Young‐Hee , Kim Young‐Ju , Lee Jieun , Tae Jinsung
Published: April 2007

A formal synthesis of (−)‐apicularen A, a potent antitumor agent with unique biological properties, has been completed in a 15‐step sequence starting from a known, enantiomerically pure hydroxyepoxide, which was generated by using the Jacobsen hydrolytic‐kinetic‐resolution methodology. The 12‐membered macrocyclic lactone in the target was constructed by ring‐closing metathesis, and thetrans‐tetrahydropyran ring system was created through the transannular etherification of a hydroxyalkene.
Development and Analysis of Modified Paired Comparisons by Use of Linearized Nonlinear Regression
Authors: Walsh John E.
Published: April 2007

The linearized nonlinear regression method (Walsh, 1963) has substantial curve‐fitting flexibility. It also permits isolation and probabilistic investigation of pertinent effects, and can be used for developing paired comparisons for persons, animals, or plants (“items” of a given type). Here, an item is identified by the values for specified characteristics, and two kinds of “treatment” (e. g., exposure and nonexposure to radiation) are compared with respect to observed values for a given characteristic. Ideally, two items being compared for treatment effect should be the same with regard to the other characteristics (those not used for comparison). That is, they should have the same set of values for these other characteristics. This ideal situation seldom occurs. However, by suitable use of the linearized nonlinear regression model, composite items can be constructed (for given treatment) that are the same with respect to the other characteristics. Modified paired comparisons are obtained on the basis of these composite items. The probability properties of modified paired comparisons can be very heterogeneous, so that special concepts and statistical techniques are needed. Two approaches for development of tests and confidence intervals are given. Some applications involving exposure to radiation are discussed.
Silica‐immobilized enzymes for multi‐step synthesis in microfluidic devices
Authors: Luckarift Heather R. , Ku Bosung S. , Dordick Jonathan S. , Spain Jim C.
Published: April 2007

The combinatorial synthesis of 2‐aminophenoxazin‐3‐one (APO) in a microfluidic device is reported. Individual microfluidic chips containing metallic zinc, silica‐immobilized hydroxylaminobenzene mutase and silica‐immobilized soybean peroxidase are connected in series to create a chemo‐enzymatic system for synthesis. Zinc catalyzes the initial reduction of nitrobenzene to hydroxylaminobenzene which undergoes a biocatalytic conversion to 2‐aminophenol, followed by enzymatic polymerization to APO. Silica‐immobilization of enzymes allows the rapid stabilization and integration of the biocatalyst within a microfluidic device with minimal preparation. The system proved suitable for synthesis of a complex natural product (APO) from a simple substrate (nitrobenzene) under continuous flow conditions. Biotechnol. Bioeng. 2007;98: 701–705. © 2007 Wiley Periodicals, Inc.
Isolated tumour cells in blood and E-cadherin expression in oesophageal squamous cell cancer
Authors: Setoyama T , Natsugoe S , Okumura H , Matsumoto M , Uchikado Y , Aikou T
Published: April 2007

Background

Patients with oesophageal squamous cell carcinoma have a high rate of recurrence, even after curative resection. The aim of this study was to examine the correlation between the presence of isolated tumour cells (ITCs) in the blood and recurrence, and between the presence of ITCs and E-cadherin expression in the primary tumour in these patients.

Methods

Blood samples obtained immediately before and after resection in 125 patients with oesophageal squamous cell carcinoma were examined by real-time reverse transcription–polymerase chain reaction using carcinoembryonic antigen mRNA. Blood samples from 28 healthy volunteers and 42 patients with benign diseases were used as controls.

Results

Seventy-seven patients (61·6 per cent) were ITC positive. ITC positivity correlated significantly with tumour depth, lymph node metastasis, stage, lymphatic invasion and venous invasion. Multivariable analysis revealed that tumour depth and ITC positivity were independent factors for a shortened haematogenous disease-free interval. A significant correlation was found between ITC positivity and reduced E-cadherin expression in the primary tumour (P < 0·001). ITC-positive patients with preserved E-cadherin expression had a longer disease-free interval (P = 0·016), haematogenous disease-free interval (P = 0·020) and overall survival (P = 0·004) than those with reduced E-cadherin expression.

Conclusion

Examination of ITCs in the blood is useful for predicting haematogenous recurrence in patients with oesophageal squamous cell carcinoma.
The basilar venous plexus
Authors: Tubbs R. Shane , Hansasuta Ake , Loukas Marios , Louis Robert G. , Shoja Mohammadali M. , Salter E. George , Oakes W. Jerry
Published: April 2007

The basilar venous plexus is the anteromedian venous channel of the posterior cranial fossa that has many conflicting and brief descriptions in the extant literature. To our knowledge, no single study has been performed that analyzed this venous structure in detail. The aim of the current study was to elucidate further the anatomy of this structure of the posterior cranial fossa. The authors examined twenty adult cadaveric specimens following injection of the internal jugular veins or cavernous sinus to observe the morphology of the basilar plexus. All specimens were found to have a basilar plexus which was always plexiform and very variable in nature. This structure was dorsal to the clivus superiorly and dorsal clivus and overlying tectorial membrane inferiorly. The mean diameter of the channels making up this plexus was 1.1 mm. Communication was always found between the basilar plexus and the inferior petrosal sinuses and this was the primary route used to drain the basilar sinus out of the cranium. In fact, these two venous structures were more or less contiguous across the midline at multiple levels. In seven specimens (35%), the basilar plexus communicated with veins draining into the hypoglossal canal. The basilar plexus communicated with the marginal sinus in 12 specimens (60%). This plexus became much less concentrated as it descended inferior to a plane between the jugular tubercles. No specimen was found to have connections with veins of the anterior brain stem or ventral surface of the clivus. The basilar plexus is a highly variable posterior fossa venous structure. Clinicians and radiologists should take into account this variability when managing cerebral venous disorders or interpreting imaging studies of the skull base. Clin. Anat. 20:755–759, 2007. © 2007 Wiley‐Liss, Inc.
Bone formation as a potential motive force of tooth eruption in the rat molar
Authors: Wise Gary E. , Yao Shaomian , Henk William G.
Published: April 2007

The objectives of this anatomical study were to (1) determine if significant bone growth occurs in the base of the alveolar bony crypt of the first mandibular molar to move the tooth through the eruption pathway; (2) determine if the osteogenesis in the crypt correlates with the published chronological gene expression of bone morphogenetic protein‐2 (BMP‐2) in the dental follicle; and (3) determine chronologically and regionally the crypt bone activity. To accomplish this, the alveolar bony crypts of rat mandibular molars from postnatal days 3 to 18 were processed and examined by scanning electron microscopy (SEM). In addition, mandibles and teeth of ages 12–18 were prepared for light microscopy. SEM demonstrated that bone formation occurs in the basal (apical) portion of the alveolar bony crypt at day 3, whereas bone resorption concurrently is ongoing in the coronal region of the crypt. By day 9, the crypt is beginning to be reduced in depth as the result of basal bone formation, and by day 14, the base of the crypt immediately under the tooth is almost completely filled with bone to form the interradicular septum. At day 18, the tooth erupts as bone formation likely elevates the molar. Bone growth in the basal area of the crypt correlates with a previous study showing enhanced BMP‐2 expression in the dental follicle. Thus, SEM indicates that the motive force of tooth eruption likely is bone formation at the base of the alveolar crypt and this osteogenesis may relate to BMP‐2 production in the dental follicle. Clin. Anat. 20:632–639, 2007. © 2007 Wiley‐Liss, Inc.
Using computer vision to simulate the motion of virtual agents
Authors: Musse Soraia R. , Jung Cláudio R. , Jacques Julio C. S. , Braun Adriana
Published: April 2007

In this paper, we propose a new model to simulate the movement of virtual humans based on trajectories captured automatically from filmed video sequences. These trajectories are grouped into similar classes using an unsupervised clustering algorithm, and an extrapolated velocity field is generated for each class. A physically‐based simulator is then used to animate virtual humans, aiming to reproduce the trajectories fed to the algorithm and at the same time avoiding collisions with other agents. The proposed approach provides an automatic way to reproduce the motion of real people in a virtual environment, allowing the user to change the number of simulated agents while keeping the same goals observed in the filmed video. Copyright © 2007 John Wiley & Sons, Ltd.
Believable interaction with a quasi‐tangible tabletop interface
Authors: Lee Jangho , Lee Jun , Kim HyungSeok , Kim Jee‐In
Published: April 2007

In this paper, we present a believable interaction mechanism for manipulation multiple objects in ubiquitous/augmented virtual environment. A believable interaction in multimodal framework is defined as a persistent and consistent process according to contextual experiences and common‐senses on the feedbacks. We present a tabletop interface as a quasi‐tangible framework to provide believable processes. An enhanced tabletop interface is designed to support multimodal environment. As an exemplar task, we applied the concept to fast accessing and manipulating distant objects. A set of enhanced manipulation mechanisms is presented for remote manipulations including inertial widgets, transformable tabletop, and proxies. The proposed method is evaluated in both performance and user acceptability in comparison with previous approaches. The proposed technique uses intuitive hand gestures and provides higher level of believability. It can also support other types of accessing techniques such as browsing and manipulation. Copyright © 2007 John Wiley & Sons, Ltd.
Computer aided generation of stylized maps
Authors: Adabala Neeharika , Varma Manik , Toyama Kentaro
Published: April 2007

Geographic maps have existed from early stages of human civilization. Various styles of visualizing the geographic information have evolved depending on the nature of information and the technology available for visualization. This has led to innumerable map styles. In this work we develop a technique to create maps by combining two‐dimensional and three‐dimensional information such that the resulting maps are both functional and aesthetically appealing. Our technique requires geographical information in vector form and aerial images as inputs. We use computer vision based approaches and user defined inputs to augment the vector data with information that is required to create stylized maps. We define procedural graphics methods to generate a range of geographic elements that can be composed together into a stylized map. We demonstrate our technique by generating example maps of a region in Las Vegas. Copyright © 2007 John Wiley & Sons, Ltd.
In vitro effects of 2‐methoxyestradiol on cell morphology and Cdc2 Kinase activity in SNO oesophageal carcinoma cells
Authors: Joubert Annie , Marais Sumari
Published: April 2007

The effects of 1 × 10−6 M exogenous 2‐methoxyestradiol (2 ME) were determined on cell morphology and cell division cycle (Cdc) 2 kinase activity in SNO oesophageal carcinoma cells. Mitotic indices revealed an increase in metaphase cells (11.2%) when compared to the 0.5% vehicle‐treated cells after 18 h of exposure to 2 ME. Vehicle‐treated control cells did not show any hallmarks of apoptosis after 18 h of exposure to dimethyl sulphoxide. Only 0.5% of 2 ME‐treated cells showed characteristics of apoptosis. Conversely, increased morphological hallmarks of apoptosis were observed in SNO‐treated cells after 21.5 h of 2 ME exposure. When compared to the 0.5% in vehicle‐treated cells, 4.7% of cells were in apoptosis. Furthermore, 34.1% of cells were blocked in metaphase after 21.5 h of 2 ME exposure compared to 0.6% of vehicle‐control cells. In addition, Cdc2 kinase activity was statistically significantly increased (1.3‐fold) (p < 0.005) in 2 ME‐treated cells when compared to vehicle‐treated controls. The present preliminary study suggests that the accumulation observed in metaphase cells and the increase in Cdc2 kinase activity caused by 2 ME are consistent with morphological hallmarks of mitotic arrest and disrupted mitotic spindle formation, thus leading to induction of apoptosis in SNO cells. Copyright © 2007 John Wiley & Sons, Ltd.
Retrograde recanalization of chronically occluded coronary arteries: Illustration and description of the technique
Authors: Kukreja Neville , Serruys Patrick W. , Sianos Georgios
Published: April 2007

Chronic total occlusions remain one of the last frontiers in interventional cardiology, with far lower procedural success rates compared with other lesion subsets. The benefits of successful treatment include improvements in angina and survival. One method, which may improve technical success rates, is the use of a retrograde approach. We report three cases employing a retrograde approach and describe the technique in detail. © 2007 Wiley‐Liss, Inc.
Beyond the Structure–Property Relationship Paradigm: Influence of the Crystal Structure and Microstructure on the Li+ Conductivity of La2/3LixTi1−xAlxO3 Oxides
Authors: García‐Martín Susana , Morata‐Orrantía Ainhoa , Alario‐Franco Miguel A. , Rodríguez‐Carvajal Juan , Amador Ulises
Published: April 2007

The crystal structures of several oxides of the La2/3LixTi1−xAlxO3 system have been studied by selected‐area electron diffraction, high‐resolution transmission electron microscopy, and powder neutron diffraction, and their lithium conductivity has been by complex impedance spectroscopy. The compounds have a perovskite‐related structure with a unit cell √2 ap×2 ap×√2 ap (ap=perovskite lattice parameter) due to the tilting of the (Ti/Al)O6 octahedra and the ordering of lanthanum and lithium ions and vacancies along the 2 ap axis. The Li+ ions present a distorted square‐planar coordination and are located in interstitial positions of the structure, which could explain the very high ionic conductivity of this type of material. The lithium conductivity depends on the oxide composition and its crystal microstructure, which varies with the thermal treatment of the sample. The microstructure of these titanates is complex due to formation of domains of ordering and other defects such as strains and compositional fluctuations.
Crystal Structure, Thermal and Compositional Deformations of β‐CsB5O8.
Authors: Bubnova R. , Dinnebier R. E. , Filatov S. , Anderson J.
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Single‐Crystal Growth and Characterization of Disilver(I) Monofluorophosphate(V), Ag2PO3F: Crystal Structure, Thermal Behavior, Vibrational Spectroscopy, and Solid‐State 19F, 31P, and 109Ag MAS NMR Spectroscopy.
Authors: Weil Matthias , Puchberger Michael , Fueglein Ekkehard , Baran Enrique J. , Vannahme Julia , Jakobsen Hans J. , Skibsted Joergen
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Cation—Cation Interactions and Antiferromagnetism in Na[Np(V)O2(OH)2]: Synthesis, Structure, and Magnetic Properties.
Authors: Almond Philip M. , Skanthakumar S. , Soderholm L. , Burns Peter C.
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Design and Synthesis of Novel C2‐Symmetric Chiral Piperazines and an Application to Asymmetric Acylation of σ‐Symmetric 1,2‐Diols.
Authors: Nakamura Daisuke , Kakiuchi Kiyomi , Koga Kenji , Shirai Ryuichi
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Rhodium‐Catalyzed Asymmetric Hydrosilylation of Ketones Using HETPHOX Ligands.
Authors: Coyne Anthony G. , Guiry Patrick J.
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Efficient Transamidation of Primary Carboxamides by in situ Activation with N,N‐Dialkylformamide Dimethyl Acetals.
Authors: Dineen Thomas A. , Zajac Matthew A. , Myers Andrew G.
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Selective Synthesis of (2Z,4E)‐Dienyl Esters by Ene—Diene Cross Metathesis.
Authors: Moura‐Letts Gustavo , Curran Dennis P.
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Reactions of Thioketones Possessing a Conjugated C=C Bond with Diazo Compounds.
Authors: Egli Daniel H. , Linden Anthony , Heimgartner Heinz
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
InCl3‐Catalyzed Alkylation of Aromatic and Heteroaromatic Compounds with Cyclic Allylic Acetates.
Authors: Yadav J. S. , Reddy B. V. Subba , Rao K. Vishweshwar , Rao P. Purushothama , Raj K. Sarita , Prasad A. R. , Prabhakar A. , Jagadeesh B.
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Allylpalladium Umpolung in the Three‐Component Coupling Synthesis of Homoallylic Amines.
Authors: Hopkins Chad D. , Malinakova Helena C.
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Chemoenzymatic Synthesis of the Chiral Herbicide: (S)‐Metolachlor.
Authors: Zheng Liangyu , Zhang Suoqin , Wang Fang , Gao Gui , Cao Shugui
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Novel Synthetic Methodologies. Part 99. Facile One‐Pot Multicomponent Synthesis of β‐Acetamido Ketones with Amberlyst‐15 as Heterogeneous Catalyst.
Authors: Das Biswanath , Reddy Kongara Ravinder
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Moderate Generation of Sulfenylnitrenes from Novel N‐Sulfenylsulfodiimides.
Authors: Yoshimura Toshiaki , Fujie Tetsuo , Fujii Takayoshi
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
An Easy and Convenient Synthesis of 2‐Furan‐2‐ylacetamides by Sequential Palladium‐Catalyzed Oxidative Aminocarbonylation of (Z)‐2‐En‐4‐yn‐1‐ols/Conjugate Addition/Aromatization.
Authors: Gabriele Bartolo , Plastina Pierluigi , Salerno Giuseppe , Mancuso Raffaella
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis of Mono‐ and Bis‐Arylated 3,4‐(Ethylenedioxythiophenes) via Direct Palladium‐Catalyzed Arylation Reactions.
Authors: Mohanakrishnan Arasambattu K. , Amaladass P. , Clement J. Arul
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis of End‐Blocked Thienyl Oligomers Incorporating Benzo[c]thiophene.
Authors: Mohanakrishnan Arasambattu , Amaladass P. , Clement J. Arul
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Condensation Reactions at the Methylene Group of 1‐(4‐Nitrophenyl)pyrrolin‐2‐one and 1‐(4‐Nitrophenyl)pyrrolin‐2‐onium Perchlorate.
Authors: Sibiryakova M. A. , Muzychenko G. F. , Kosulina T. P. , Pushkareva K. S.
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
One‐Pot Synthesis of Oxime Derivatives of 1,3‐Diphenylpyrazole‐4‐carboxaldehydes from Acetophenone Phenylhydrazones Using Vilsmeier—Haack Reagent.
Authors: Prakash Om , Pannu Kamaljeet , Naithani Rajesh , Kaur Harpreet
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis of 4‐Arylcarbamoyl‐5‐(2‐hydroxynaphthylazo)imidazoles and 1‐Substituted Naphtho[2,1‐e]imidazo[5,1‐c][1,2,4]triazines.
Authors: Sadchikova E. V. , Mokrushin V. S.
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
First Example of Lewis Acid Catalyzed 3‐Substituted 5‐Arylidene‐1‐methyl‐2‐thiohydantoin Formation.
Authors: Gregg Brian T. , Earley William G. , Golden Kathryn C. , Quinn John F. , Razzano Dana A. , Rennells W. Martin
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
A Convenient Access to Substituted Benzothiazole Scaffolds via Intramolecular Cyclization of Thioformanilides.
Authors: Bose D. Subhas , Idrees Mohd.
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
A Convenient Synthesis of Tetrazolo[1,5‐a]‐α‐cycloalkanones.
Authors: Shi Yan , Robl Jeffrey A. , Kennedy Lawrence J. , Malley Mary F.
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Enantioselective Synthesis of 3,4‐Dihydropyran‐2‐ones by Domino Michael Addition and Lactonization with New Asymmetric Organocatalysts. Cinchona‐Alkaloid‐Derived Chiral Quaternary Ammonium Phenoxides.
Authors: Tozawa Takashi , Nagao Hitoshi , Yamane Yoshinobu , Mukaiyama Teruaki
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Solvent‐Free Synthesis of 5‐Oxo‐5,6,7,8‐tetrahydro‐4H‐benzo‐[b]‐pyran Derivatives under Microwave Irradiation.
Authors: Hu Xue Yuan , Fan Xue Sen , Zhang Xin Ying , Qu Gui Rong , Li Yan Zhen
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Hydantoins and Thiohydantoins Derived from 1,2,3,4‐Tetrahydroisoquinoline‐3‐carboxylic Acid.
Authors: Jansa Petr , Wsol Vladimir , Bertolasi Valerio , Machacek Vladimir
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis and Biological Evaluation of New 4H‐Pyrano[2,3‐b]quinoline Derivatives that Block Acetylcholinesterase and Cell Calcium Signals, and Cause Neuroprotection Against Calcium Overload and Free Radicals.
Authors: Marco‐Contelles Jose , Leon Rafael , Lopez Manuela G. , Garcia Antonio G. , Villarroya Mercedes
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
New Efficient Synthesis of 2‐Substituted Benzothieno[3,2‐d]pyrimidin‐4(3H)‐ones via a Tandem Aza‐Wittig Reaction.
Authors: Xu Sheng‐Zhen , Hu Yang‐Gen , Ding Ming‐Wu
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis and Tautomeric Transformations of 2‐(tert‐Butyl)‐1,2,4‐Benzotriazine‐3(2H)‐thiones.
Authors: Lipilin D. L. , Tyurin A. Yu. , Smirnov O. Yu. , Churakov A. M. , Strelenko Yu. A. , Tartakovsky V. A.
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
A Facile Synthesis of 3‐Methylene‐4‐aryl‐1,3,4,5‐tetrahydrobenzo[b][1,4]diazepin‐2‐ones and 3‐Arylmethylene‐4,5‐dihydro‐3H‐benzo[b][1,4]diazepin‐2‐ylamines.
Authors: Pathak R. , Nag S. , Batra S.
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Dirhodium(II) Tetrakis(perfluorobutyrate)‐Catalyzed 1,4‐Hydrosilylation of α,β‐Unsaturated Carbonyl Compounds.
Authors: Anada Masahiro , Tanaka Masahiko , Suzuki Kanami , Nambu Hisanori , Hashimoto Shunichi
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Non‐Catalyzed, Atom‐Economic, High‐Yield Synthesis of Tertiary α‐Hydroxyphosphane Selenides.
Authors: Gusarova Nina K. , Ivanova Nina I. , Konovalova Nataliya A. , Sukhov Boris G. , Baikalova Ludmila V. , Sinegovskaya Lidiya M. , Pavlov Dmitriy V. , Trofimov Boris A.
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Stereospecific Diphosphination of Activated Acetylenes: A General Route to Backbone‐Functionalized, Chelating 1,2‐Diphosphinoethenes.
Authors: Dodds Deborah L. , Haddow Mairi F. , Orpen A. Guy , Pringle Paul G. , Woodward Gary
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis of Loliolide (I), Actinidiolide (II), Dihydroactinidiolide (III), and Aeginetolide (IV) via Cerium Enolate Chemistry.
Authors: Eidman Kirk F. , MacDougall Brian S.
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Preparation of the Central Tryptophan Moiety (I) of the Celogentin/Moroidin Family of Antimitotic Cyclic Peptides.
Authors: Yuen Alexander K. L. , Jolliffe Katrina A. , Hutton Craig A.
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Total Synthesis of Natural and Unnatural Lamellarins with Saturated and Unsaturated D‐Rings.
Authors: Ploypradith Poonsakdi , Petchmanee Thaninee , Sahakitpichan Poolsak , Litvinas Nichole D. , Ruchirawat Somsak
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Xyloketal H from the Mangrove Endophytic Fungus Xylaria sp. 2508.
Authors: Liu X. , Xu F. , Zhang Y. , Liu L. , Huang H. , Cai X. , Lin Y. , Chan W.
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
A Short and Efficient Synthesis of (‐)‐Diospongin A.
Authors: Bressy Cyril , Allais Florent , Cossy Janine
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Biologically Active Secondary Metabolites from Fungi. Part 25. Absolute Configurations of Globosuxanthone A and Secondary Metabolites from Microdiplodia sp. — A Novel Solid‐State CD/TDDFT Approach.
Authors: Hussain Hidayat , Krohn Karsten , Floerke Ulrich , Schulz Barbara , Draeger Siegfried , Pescitelli Gennaro , Antus Sandor , Kurtan Tibor
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Structures of New Flavonoids, Erycibenins D, E, and F, and NO Production Inhibitors from Erycibe expansa Originating in Thailand.
Authors: Morikawa Toshio , Xu Fengming , Matsuda Hisashi , Yoshikawa Masayuki
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Total Synthesis of (.+‐.)‐Decursivine.
Authors: Leduc Andrew B. , Kerr Michael A.
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Hepatitis B Virus Inhibiting Constituents from Herpetospermum caudigerum.
Authors: Yuan Hai‐Long , Yang Ming , Li Xian‐Yi , You Rong‐Hui , Liu Yi , Zhu Jun , Xie Huan , Xiao Xiao‐He
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Zero‐Stress Optic Glass Without Lead.
Authors: Guignard M. , Albrecht L. , Zwanziger J. W.
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Arylmethyl Substituted Derivatives of Fosmidomycin: Synthesis and Antimalarial Activity.
Authors: Schlueter Katrin , Walter Rolf D. , Bergmann Baerbel , Kurz Thomas
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
4‐(Pyrrolidinyl)methoxybenzoic Acid Derivatives as a Potent, Orally Active VLA‐4 Antagonist.
Authors: Chiba Jun , et al. et al.
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Elucidating DNA Damage and Repair Processes by Independently Generating Reactive and Metastable Intermediates
Authors: Greenberg Marc M.
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Transition Metals in Organic Synthesis: Cross‐Coupling and C—H Activation Processes
Authors: Fairlamb Ian J. S.
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis by Substitution of Oxygen and Sulfur Functionalities
Authors: Lequeux T. P.
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthetic Studies on Heliannuol Sesquiterpenoids with Allelopathic Activity
Authors: Kamei Tomoyo , Morimoto Sachie , Shishido Kozo
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Functional Dye Chemistry Based on Bioluminescence‐Related Molecules: Fundamental Chemistry and Application of the Imidazopyrazinone π‐System
Authors: Hirano Takashi
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Bioreactor Configurations for ex‐situ Treatment of Perchlorate
Authors: Sutton Paul M.
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Online ATR—IR Spectroscopy: Mechanistic Studies of Catalytic Reactions under High Pressure
Authors: Zintl Manuela , Hearley Andrew K. , Rieger Bernhard
Published: April 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Immobilization and Characterization of Glucose Oxidase on Single‐Walled Carbon Nanotubes and Its Application to Sensing Glucose
Authors: Liu Shu‐Na , Yin Ya‐Jing , Cai Chen‐Xin
Published: April 2007

The negatively charged (at pH 8.2) glucose oxidase (GOx, pIca.4.2) was assembled onto the surface of single‐walled carbon nanotubes (SWNT), which was covered (or wrapped) by a layer of positively charged polyelectrolyte poly(dimethyldiallylammonium chloride) (PDDA), via the electrostatic interaction forming GOx‐PDDA‐ SWNT nanocomposites. Fourier transform infrared (FTIR), UV‐Vis and electrochemical impedance spectroscopy (EIS) were used to characterize the growth processes of the nanocomposites. The results indicated that GOx retained its native secondary conformational structure after it was immobilized on the surface of PDDA‐SWNT. A biosensor (Nafion‐GOx‐PDDA‐SWNT/GC) was developed by immobilization of GOx‐PDDA‐SWNT nanocomposites on the surface of glassy carbon (GC) electrode using Nafion (5%) as a binder. The biosensor showed the electrocatalytic activity toward the oxidation of glucose under the presence of ferrocene monocarboxylic acid (FcM) as an electroactive mediator with a good stability, reproducibility and higher biological affinity. Under an optimal condition, the biosensor could be used to detection of glucose, presenting a typical characteristic of Michaelis‐Menten kinetics with the apparent Michaelis‐Menten constant ofKappMca.4.5 mmol/L, with a linear range of the concentration of glucose from 0.5 to 5.5 mmol/L (with correlation coefficient of 0.999) and the detection limit ofca.83 µmol/L (at a signal‐to‐noise ratio of 3). Thus the biosensor was useful in sensing the glucose concentration in serum since the normal glucose concentration in blood serum was around 4.6 mmol/L. The facile procedure of immobilizing GOx used in present work would promote the developments of electrochemical research for enzymes (proteins), biosensors, biofuel cells and other bioelectrochemical devices.
The Reaction of Molybdenum with 2,3‐Dihydroxynaphthalene
Authors: Lu Xiao‐Ming , Pei Xiu‐Huan , Wang Xiao‐Jun , Ye Chao‐Hui
Published: April 2007

[H2N(CH2)3NH3]2[MoO2(C10H6O2)2] (1) was synthesized by the reaction of (n‐Bu4N)4[Mo8O26] with 2,3‐dihydroxynaphthalene in the mixed solvent of CH3OH, CH3CN and 1,3‐propanediamine. (C5H11N2)2‐ [H2N(CH2)3NH2][MoO2(C10H6O2)2] (2) was obtained by the reaction of Na2MoO4·2H2O with 2,3‐dihydroxy‐ naphthalene in the same solvent above. Both of the complexes possess complex anion [Mo(VI)O2(OC10H6O)2]2−which shows pseudo‐octahedrally coordinated fashion, while the counterions are two protonated 1,3‐propanedia‐ mine in complex1and (C5H11N2)+in complex2. (C5H11N2)+is the byproduct of reaction 2, which results from combination of acetonitrile with 1,3‐propanediamine. Packing diagrams of the two complexes are also different. There is anti‐parallel‐aligned‐double‐meso‐bilayer unit in complex1. However there are four chiral anions arranged in anticlockwise orientation in complex2.
CoMFA 3D‐QSAR Analysis of Epothilones Based on Docking Conformation and Alignment
Authors: Yuan Wei , Luan Lin‐Bo , Li Yan‐Ni
Published: April 2007

Epothilones belong to a class of novel microtubule stabilizing and anti‐mitotic agents, which have a paclitaxel‐like mechanism of action. A three‐dimensional quantitative structure‐activity relationship (3D‐QSAR) model was built for epothilones by the method of comparative molecular field analysis (CoMFA) combined with the flexible docking technology. The docking CoMFA model gave a good cross‐validated value of q2=0.784 with an optimized component of 6 and the conventional correlation coefficient of r2=0.985. The statistical results show that the model has good ability to predict the activity of the studied compounds. At last, the docking CoMFA model was analyzed through contour maps complemented with MOLCAD‐generated active site potential surface in the α,β‐tubulin receptor, which can provide important information for the structure‐based drug design.
Theoretical Study on One‐ and Two‐Photon Absorption Properties of PPV Derivative with Electron‐Donor Phenylanthracene as Pendent Group
Authors: Zhao Liang , Mu Li , Yang Guo‐Chun , Su Zhong‐Min , Qin Chun‐Sheng , Shao Chen
Published: April 2007

Based on the equilibrium structures from quantum mechanics AM1 method, employing INDO/CI method and the sum‐over‐state (SOS) formula, the one‐photon absorption (OPA) and two‐photon absorption (TPA) properties as well as the second hyperpolarizabilities were discussed in detail for a kind of PPV derivative poly 2‐(9‐phenylan‐ thracen‐10‐yl)‐1,4‐phenylenevinylene (P1). The results indicate that the two‐photon cross section (δ) increases with the increasing of the number of repeating segment (n), however only a slight increase corresponds to the increasing of molecular weight when the repeating unit number arrives at a certain number. From this point of view, the TPA cross section values of P1 were extrapolated through the linear fit of δ value vs. 1/n. The δ value of P1 is as high as 181 GM (1 GM10−50 cm4·s·photon−1). Concerning the influence of pendent group and extension of π‐conjuga‐ tion on δ values, another four oligomers P2, PPV, P1‐1, and P2‐1 were investigated for comparison. The calculation results reveal that the position and property of pendent group have great influence on the OPA and TPA properties. A most crucial role for relatively larger δ value was played by the extension of π‐conjugation.
Solubilities, Densities and Refractive Indices of Rubidium Chloride or Cesium Chloride in Ethanol Aqueous Solutions at Different Temperatures
Authors: Zhao Wen‐Xia , Hu Man‐Cheng , Jiang Yu‐Cheng , Li Shu‐Ni
Published: April 2007

The data of solubilities, densities and refractive indices of rubidium chloride or cesium chloride in the system C2H5OH‐H2O were measured by using a simple accurate analytical method at different temperatures, with mass fractions of ethanol in the range of 0 to 1.0. In all cases, the presence of ethanol significantly reduced the solubility of rubidium chloride and cesium chloride in aqueous solution. The solubilities of the saturated solutions were fitted via polynomial equations as a function of the mass fraction of ethanol. The CsCl‐C2H5OH‐H2O ternary system appeared in two liquid phases:alcoholic phase and water phase, when the mass fractions of ethanol were in the range of 10.37% to 49.59% at 35 °C. Density and refractive index were also determined for the same ternary systems with varied unsaturated salt concentrations. Values for both experiment and theory were correlated with the salt concentrations and proportions of alcohol in the solutions. The equations proposed could also account for the saturated solutions.
Influences of Triton X‐100 on Hemoglobin Behaviors in Hemoglobin/Acyclovir/Triton X‐100/H2O System
Authors: Liu Tian‐Qing , Guo Rong
Published: April 2007

The influences of Triton X‐100 on hemoglobin (Hb) behaviors were studied by the methods of UV‐Vis spectrum, fluorescence spectrum, HPLC, conductivity, zeta potential and negative‐staining transmission electron microscope in Hb/acyclovir/Triton X‐100/H2O system. With the increase of Triton X‐100 concentration in the system, the percentage of the free acyclovir increased from 58%–63% to 90%–94%. The static quenching constant and the association number of acyclovir to Hb decreased. The fluorescence spectrum, conductivity, zeta potential, fluorescence polarization and negative‐staining morphology of Hb tended to recover to those of the original state of Hb in the same concentration of Hb. The interaction between Triton X‐100 and Hb is stronger than that between acyclovir and Hb. Most Triton‐X‐100 was associated with Hb at low Triton X‐100 concentration. But the interaction of Triton X‐100 with Hb was apparently dominant in high Triton X‐100 concentration. The Hb structure was unfolded and finally denatured.
Synthesis, Crystal Structures and Properties of Two Novel Co(II) and Cd(II) Complexes of N‐Acetyl‐L‐glutamic Acid and Imidazole Ligands
Authors: Cheng Meng‐Qi , Ma Lu‐Fang , Wang Li‐Ya
Published: April 2007

Two novel complexes {(Co(A‐glu)(Im)2(·0.5H2O}n (1) and (Cd(A‐glu)(Im)3(n (2) (H2A‐gluN‐acetyl‐L‐glu‐ tamic acid, Im=imidazole) have been synthesized from the reaction of H2A‐glu with Co(CH3COO)2·4H2O or Cd(CH3COO)2·2H2O in the presence of Im. Both of the complexes display different coordination environment and similar one‐dimensional chain structure. The magnetic susceptibility measurements for 1 show a weak antiferromagnetic interaction between two cobalt(II) ions bridged by A‐glu ligand. The complex 2 exhibits an intense fluorescent emission in solid state at room temperature.
Study on Preconcentration of Trace Copper Using Microcrystalline Triphenylmethane Loaded with Malachite Green
Authors: Liang Yong , Zhao Xiao‐Hong , Li Quan‐Min , Cui Feng‐Ling , Liu Guo‐Guang
Published: April 2007

The paper describes a novel method for copper preconcentration using microcrystalline triphenylmethane loaded with malachite green prior to the determination by the flame atomic absorption spectrometry (FAAS). Under the optimum conditions, Cu(II) can be totally adsorbed on the surface of microcrystalline triphenylmethane, and completely separated from Pb(II), Cd(II), Co(II), Cr(III), Ni(II), Mn(II), Fe(III) and Al(III) by controlling acidity. The preconcentration factor of this proposed method is 200. The recovery is in a range of 97.5%–105%. The relative standard deviation (RSD) is not beyond 3.0%. The proposed method has been successfully applied to the determination of trace copper in various water samples with satisfactory results.
Determination of Trace Arsenic by Solid Substrate‐Room Temperature Phosphorescence Quenching Method Based on the Catalyzed Reaction of H2O2 Oxidizing 9‐Hydroxy‐2,3,4,9‐tetrahydro‐1,10‐anthraquinone
Authors: Hu Shi‐Rong , Wen Quan , Kong Xiang‐Bin , Luo Cai‐Ying , Chen Hui‐Hua , Chen Li‐Fen , Zhang Yu‐Ping
Published: April 2007

A new solid substrate‐room temperature phosphorescence (SS‐RTP) quenching method for the determination of trace As(V) has been developed, based on the facts that 9‐hydroxy‐2,3,4,9‐tetrahydro‐1,10‐anthraquinone (R) can emit intense and stable SS‐RTP on solid substrate, and α,α′‐dipyridyl can activate As(V) catalysis of the reaction of H2O2 oxidizing R to non‐phosphorescence compound R′, which can cause the sharp quenching of SS‐RTP. Under the optimum condition, the relationship between the ΔIp of the emitting intensity and 1.60–160 fg·spot−1 As(V) (corresponding concentration:0.0040–0.40 ng·mL−1, sample volume:0.4 µL·spot−1) conformed to Beer′ law. The regression equation of working curve can be expressed as ΔIp20.46+0.5492cAs(V) (fg·spot−1) (r=0.9995, n=6). The limit detection (LD) is 0.27 fg·spot−1 [As(V) corresponding concentration:6.8×10−13 g·mL−1, n=11]. The samples containing 0.0040 and 0.40 ng·mL−1 As(V) were repeatedly determined for 11 times. RSD are 3.0% and 2.7% respectively. The SS‐RTP mechanism was also discussed. R was synthesized in this paper. Meanwhile, the structure was determined by NMR, IR , mass spectra and elemental analysis.