bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of Some New Fused and Spiro 1,4‐Benzoxazine Derivatives.
Authors: Moustafa H. M.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Pd‐Catalyzed Cross‐Coupling Reaction of (Z)‐ and (E)‐Bromoenyne: Unusual Stereochemical Outcome.
Authors: Uenishi Jun'ichi , Matsui Katsuaki , Ohmi Masashi
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Stereoselective Synthesis of 19‐Hydroxytaxoid Using Intramolecular Pinacol Coupling Reaction.
Authors: Mukaiyama Teruaki , Ogawa Yasuyuki , Kuroda Kiichi , Matsuo Jun‐ichi
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
C31—C34 Methylated Squalenes from a Bolivian Strain of Botryococcus braunii.
Authors: Achitouv Etienne , Metzger Pierre , Rager Marie‐Noelle , Largeau Claude
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Preparation of 3,17‐ and 3,20‐Difluoro‐Derivatives of the Androst‐5‐ene and Pregn‐5‐ene Series.
Authors: Decreau Richard A. , Marson Charles M.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Diastereoselective Synthesis of (2S,5R)‐5‐Hydroxypipecolic Acid and 6‐Substituted Derivatives.
Authors: Botman Peter N. M. , Dommerholt F. Jan , de Gelder Rene , Broxterman Quirinus B. , Schoemaker Hans E. , Rutjes Floris P. J. T. , Blaauw Richard H.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Synthesis of 4′‐Methyl and 4′‐Cyano Carbocyclic 2′,3′‐Didehydro Nucleoside Analogues via 1,4‐Addition to Substituted Cyclopentenones.
Authors: Hegedus Louis S. , Cross Jeff
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Regioselective Synthesis of C‐Nucleosides via Condensation of 2‐Hydrazino‐thia‐diaza‐benzo[a]azulen‐4‐one.
Authors: El‐Gazzar A. B. A.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Recent Developments in Self‐Propagating High‐Temperature Synthesis of TiC
Authors: Dubois S. , Vrel D. , Cochepin B. , Karnatak N. , Heian E. M.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Peculiarities of Intergranular Corrosion of Silicon‐Containing Austenitic Stainless Steels
Authors: Kasparova O. V.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Development of Bridged Nucleic Acid Analogues for Antigene Technology
Authors: Obika Satoshi
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Molecules with a Genuine Si—Si Triple Bond and a Stable Derivative of [SiH]+
Authors: Weidenbruch Manfred
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Combinatorial Chemistry: A Novel Method in Drug Discovery and Its Application
Authors: Pandeya S. N. , Thakhar D.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Purines
Authors: Seela F. , Ramzaeva N. , Rosemeyer H.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Chiral Solid‐State Photochemistry Including Supramolecular Approaches
Authors: Koshima Hideko
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Coherent Laser Control of the Handedness of Chiral Molecules
Authors: Brumer Paul , Shapiro Moshe
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Direct Asymmetric Photochemistry with Circularly Polarized Light
Authors: Rau Hermann
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Organic Photochemistry
Authors: Boyd Mary K. , Zopp Garrett M.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Thioamides: Some Properties and Preparations
Authors: Velkov Zh.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Crown Ethers in Enantioselective Synthesis
Authors: Tbke L. , Bako P. , Keglevich Gy. , Bako T.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Symmetrical P,P′‐disubstituted Esters of Alkylenediphosphonic Acids as Reagents for Metal Solvent Extraction
Authors: Chiarizia R. , Herlinger A. W.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
The Combinatorial Synthesis of Purine, Pyrimidine and Triazine‐Based Libraries
Authors: Bork Jacqueline T. , Lee Jae Wook , Chang Young‐Tae
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Surface Recognition of Biomacromolecules Using Nanoparticle Receptors
Authors: Verma Ayush , Rotello Vincent M.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Dynamics of Collagen in Articular Cartilage Studied by Solid‐State NMR Methods
Authors: Huster Daniel , Schiller Juergen , Arnold Klaus
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
High‐Throughput NMR Techniques for Combinatorial Chemical Library Analysis
Authors: Hou Ting , Raftery Daniel
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
ESR Dating, Dosimetry and Microscopy for Terrestrial and Planetary Materials
Authors: Ikeya M.
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Extraction with Metal Bis(dicarbollide) Anions Metal Bis(dicarbollide) Extractants and Their Applications in Separation Chemistry
Authors: Rais Jiri , Gruener Bohumir
Published: April 2005

For Abstract see ChemInform Abstract in Full Text.
Kinetics and Stability of CH4–CO2 Mixed Gas Hydrates during Formation and Long‐Term Storage
Authors: Uchida Tsutomu , Ikeda Ikuko Y. , Takeya Satoshi , Kamata Yasushi , Ohmura Ryo , Nagao Jiro , Zatsepina Olga Y. , Buffett Bruce A.
Published: April 2005

The formation of CH4–CO2 mixed gas hydrates was observed by measuring the change of vapor‐phase composition using gas chromatography and Raman spectroscopy. Preferential consumption of carbon dioxide molecules was found during hydrate formation, which agreed well with thermodynamic calculations. Both Raman spectroscopic analysis and the thermodynamic calculation indicated that the kinetics of this mixed gas hydrate system was controlled by the competition of both molecules to be enclathrated into the hydrate cages. However, the methane molecules were preferentially crystallized in the early stages of hydrate formation when the initial methane concentration was much less than that of carbon dioxide. According to the Raman spectra, pure methane hydrates first formed under this condition. This unique phenomenon suggested that methane molecules play important roles in the hydrate formation process. These mixed gas hydrates were stored at atmospheric pressure and 190 K for over two months to examine the stability of the encaged gases. During storage, CO2 was preferentially released. According to our thermodynamic analysis, this CO2 release was due to the instability of CO2 in the hydrate structure under the storage conditions.
Ab Initio Calculations and Franck–Condon Simulation of the Absorption Spectra of GeCl2 Including Anharmonicity
Authors: Mok Daniel K. W. , Chau Foo‐tim , Lee Edmond P. F. , Dyke John M.
Published: April 2005

Geometrical parameters, vibrational frequencies and relative electronic energies of the X̃1A1, ã3B1 and Ã1B1 states of GeCl2 have been calculated at the CCSD(T) and/or CASSCF/MRCI level with basis sets of up to aug‐cc‐pV5Z quality. Core electron correlation and relativistic contributions were also investigated. RCCSD(T)/aug‐cc‐pVQZ potential energy functions (PEFs) of the X̃1A1 and ã3B1 states, and a CASSCF/MRCI/aug‐cc‐pVQZ PEF of the Ã1B1 state of GeCl2 are reported. Anharmonic vibrational wavefunctions of these electronic states of GeCl2, obtained variationally using the computed PEFs, are employed to calculate the Franck–Condon factors (FCFs) of the ã–X̃ and Ã–X̃ transitions of GeCl2. Simulated absorption spectra of these transitions based on the computed FCFs are compared with the corresponding experimental laser‐induced fluorescence (LIF) spectra of Karolczak et al. [J. Chem. Phys. 1993, 98, 60–70]. Excellent agreement is obtained between the simulated absorption spectrum and observed LIF spectrum of the ã–X̃ transition of GeCl2, which confirms the molecular carrier, the electronic states involved and the vibrational assignments of the LIF spectrum. However, comparison between the simulated absorption spectrum and experimental LIF spectrum of the Ã–X̃ transition of GeCl2 leads to a revision of vibrational assignments of the LIF spectrum and suggests that the X̃1A1 state of GeCl2 was prepared in the experimental work, with a non‐Boltzmann vibrational population distribution. The X̃(0,0,1) level is populated over 4000 times more than expected from a Boltzmann distribution at 60 K, which is appropriate for the relative population of the other low‐lying vibrational levels, such as the X̃(1,0,0) and X̃(0,1,0) levels.
Double‐Tunnel Nanoscale Switch with a Redox Mediator: Operational Principles and Tunneling Spectroscopy
Authors: Kornyshev A. A. , Kuznetsov A. M. , Ulstrup J.
Published: April 2005

A description of the physical mechanism and operation of a novel nanometric electronic switch [D. I. Gittins et al., Nature 2000 408, 67] is presented. New options for controlling the properties of this device are suggested and analyzed.
Cover Picture: Engineering the Electronic Structure of Single‐Walled Carbon Nanotubes by Chemical Functionalization (ChemPhysChem 4/2005)
Authors: Zhao Jijun , Chen Zhongfang , Zhou Zhen , Park Hyoungki , Schleyer Paul von Ragué , Lu Jian Ping
Published: April 2005

The cover picture shows single‐walled carbon nanotube (SWCNT) sidewalls that can be opened by chemical modifications such as a CCl2 addition reaction. The SWCNT electronic structures near the Fermi level are only changed slightly by functionalizations at low modification ratios; however, at higher ratios, the metallic SWCNTs become nonmetallic. Therefore, the electronic properties of SWCNTs can be controlled by chemical modification. Details can be found in the Communication by J. Zhao, Z. Chen and co‐workers on page 598.
Platelet‐derived growth factor‐BB (PDGF‐BB) induces differentiation of bone marrow endothelial progenitor cell‐derived cell line TR‐BME2 into mural cells, and changes the phenotype
Authors: Miyata Takashi , Iizasa Hisashi , Sai Yoshimichi , Fujii Jo , Terasaki Tetsuya , Nakashima Emi
Published: April 2005

Blood vessels are composed of endothelial cells (EC) and mural cells, and the interaction between EC and mural cells is essential for the development and maintenance of the vasculature. EC differentiate from bone marrow‐derived endothelial progenitor cells (EPC). Recently, we established a conditionally immortalized bone marrow EPC‐derived cell line, TR‐BME2, and a brain capillary EC (BCEC) line, TR‐BBB, from temperature‐sensitive‐SV40 T‐antigen gene transgenic rats. To understand the function of EPC, it is important to analyze the difference between EPC and mature EC such as BCEC. In this study, we identified EPC‐specific genes by means of subtractive hybridization between TR‐BME2 and TR‐BBB. There was no significant difference between TR‐BME2 and TR‐BBB in the mRNA level of annexin II, which is expressed in EC. In contrast, the mRNA level of smooth muscle cell (SMC) markers such as smooth muscle protein 22 (SM22), calvasculin, and platelet‐derived growth factor (PDGF) receptor‐β, was higher in TR‐BME2 than in TR‐BBB. Moreover, the mRNA level of contractile SMC markers, such as smooth muscle α‐actin and SM22, was increased in the absence of EC growth factors, such as vascular endothelial growth factor. The mRNA level of synthetic SMC markers, such as matrix Gla protein, was increased by the addition of PDGF‐BB. The SMC derived from TR‐BME2 showed an altered phenotype, from contractile‐type to synthetic‐type, when they were cultured in the absence of PDGF‐BB. These results show that TR‐BME2 cells have higher levels of SMC markers compared with mature EC, and can differentiate into contractile‐ or synthetic‐type SMC. © 2005 Wiley‐Liss, Inc.
Normal rat hepatic stellate cells respond to endotoxin in LBP‐independent manner to produce inhibitor(s) of DNA synthesis in hepatocytes
Authors: Thirunavukkarasu Chinnasamy , Uemura Tadahiro , Wang Lian Fu , Watkins Simon C. , Gandhi Chandrashekhar R.
Published: April 2005

Endotoxin is implicated in the pathology of acute liver failure. The mechanisms of its actions on quiescent hepatic stellate cells (qHSCs) and their implications in hepatocyte injury are incompletely understood. We investigated effects of endotoxin (bacterial lipopolysaccharide; LPS) on qHSCs and subsequently on hepatocytes. After overnight culture following their isolation, qHSCs were incubated with or without endotoxin for 24 h. The cells and the culture supernatant were analyzed for cytokines and nitric oxide (NO) synthesis. The effects of qHSC‐conditioned media on hepatocytes were then determined. LPS increased inducible NO synthase expression, stimulated NO synthesis, and inhibited DNA synthesis in qHSCs. qHSC‐conditioned medium inhibited DNA synthesis in hepatocytes without affecting NO synthesis, while LPS (1–1,000 ng/ml)‐conditioned qHSC medium stimulated NO synthesis and caused further inhibition of DNA synthesis and apoptosis. These effects of LPS were more pronounced when qHSCs were incubated with serum, but not with LPS‐binding protein (LBP) although CD14 (a receptor for LPS‐LBP complex) was found in qHSCs. LPS stimulated the synthesis of TNF‐α, interleukin (IL)‐6, and IL‐1β but not of TGF‐β in qHSCs. Individually or together, L‐NG‐monomethylarginine and antibodies to IL‐1β, IL‐6, and TNF‐α only partly reversed qHSC + LPS‐conditioned medium‐induced inhibition of DNA synthesis in hepatocytes. These results suggest that the effects of LPS on qHSCs are novel, occurring without the aid of LBP/CD14. They also indicate that other factors, in addition to NO, TGF‐β, TNF‐α, IL‐1β, and IL‐6 are involved in the mechanisms of the growth inhibitory effects of qHSCs on hepatocytes. © 2005 Wiley‐Liss, Inc.
“Blood‐contacting neurons” in the brain of the Japanese eel Anguilla japonica
Authors: Mukuda Takoa , Matsunaga Yuzo , Kawamoto Keiichi , Yamaguchi Ken‐Ichi , Ando Masaaki
Published: April 2005

To discriminate “blood‐contacting neurons” within the brain of the eel, Evans blue (EB) was injected intraperitoneally. After five days, six brain areas were externally stained blue with the dye; the saccus dorsalis (SD), the epiphysis (E), the area postrema (AP), the posterior part of the magnocellular preoptic nucleus (PM), the pituitary (Pit), and the saccus vasculosus (SV). Among the EB‐positive area, some cells in the PM, the anterior tuberal nucleus (NAT) and the AP were discriminated as the “blood‐contacting neurons” histologically, whereas EB‐positive neurons were not detected in the SD, the E, the Pit and the SV regions. In the PM, most EB‐positive neurons (90 %) were immunoreactive to vasotocin (AVT) antibody, indicating that these neurons are vasotocinergic. The remaining EB‐positive neurons (10 %) were not immunoreactive to ANG II and tyrosine hydroxylase (TH) antibodies. Although some neurons in the PM were immunoreactive to ANG II antibody, they were EB‐negative. In contrast, almost all EB‐positive neurons in the AP showed TH‐like immunoreactivity (‐lir), indicating that these neurons utilize catecholamine(s) as a neurotransmitter. The EB‐positive neurons in the NAT were not immunoreactive to AVT, ANG II and TH antibodies, whereas some neurons without EB‐staining showed ANG II‐lir. Possible roles of these neurons in regulating drinking behavior in eels are discussed. J. Exp. Zool. 303A:366–376, 2005. © 2005 Wiley‐Liss, Inc.
Effect of graded hypoxic and acidotic stress on contractile force of heart muscle from hypoxia‐tolerant and hypoxia‐intolerant turtles
Authors: Bobb Vanessa Toney , Jackson Donald C.
Published: April 2005

Previous studies have shown that isometric contractile force of in vitro cardiac muscle from the anoxia‐tolerant painted turtle, Chrysemys picta bellii, decreases when anoxic and when acidotic. This study sought to define the thresholds for these responses in the isolated ventricular strips of the painted turtle and in the anoxia‐intolerant softshell turtles, Apalone spinifera. The ventricular strips were exposed to HCO Ringer's solution equilibrated at PO2 156, 74, 37, 19, and 0 mmHg (45 min at each grade), at both pH 7.0 and at pH 7.8. Strips were also exposed to graded lactic acidosis with intervals between pH 6.8 and pH 7.8 at PO2 156 mmHg (softshell) or 37 mmHg (painted). In painted turtle strips at pH 7.8, force remained at control levels until it decreased by 30% at PO2 19 mmHg. No further significant decrease occurred at PO20. In contrast, softshell turtle muscle force did not fall significantly until PO2 reached 0. When graded hypoxia was imposed at pH 7.0, strips from both species were more sensitive to hypoxia, but the softshell force decreased at a higher PO2 than the painted turtle (PO2 156 mmHg vs. 37 mmHg), its force fell to a lower level at PO2 0 (22 % of control vs. 40 % of control), and unlike painted turtle heart muscle, softshell muscle did not recover fully. In summary, these data indicate that ventricular strips of the painted turtle are no more tolerant of hypoxia alone than strips from the softshell turtle, but that when hypoxia is combined with acidosis, the painted turtle heart muscle functions significantly better during the exposure and recovers more fully after exposure. J. Exp. Zool. 303A:345–353, 2005. © 2005 Wiley‐Liss, Inc.
Selective processing of calling songs by auditory interneurons in the female cricket, Gryllus pennsylvanicus: possible roles in behavior
Authors: Jeffery Jason , Navia Benjamin , Atkins Gordon , Stout John
Published: April 2005

Female crickets (Gryllus pennsylvanicus), caught in the field as nymphs, responded as adults in the laboratory with selective phonotaxis to model calling songs (CSs) that reproduced the dominant carrier frequencies and syllable periods (SPs) characteristic of the male's natural calling song. Extracellular recordings demonstrated two types of auditory interneurons in the female's cervical connectives that were very similar to the AN1 and AN2 neurons previously described in other gryllid species. The AN2 neuron responded to model CSs with a phasically encoded immediate response, and a more tonically encoded prolonged response. AN2's immediate response exhibited SP‐dependent decreases (termed decrement) in its responses to sequential syllables of the CS that were greatest to CSs with the shortest SPs and diminished as SPs were lengthened, resulting in an SP‐dependent habituation. Picrotoxin application transformed this SP‐dependent habituation by AN2 to SP‐selective responses in which the degree of decrement was greatest to SPs that were most phonotactically attractive. AN2's prolonged response was most sensitive to 5 kHz CSs and correlated with the carrier frequency tuning for the thresholds of phonotaxis by females. Thus, in females, AN2's immediate (in the presence of picrotoxin) and prolonged responses were selectively tuned to the SPs and carrier frequencies of the male's calls that were most attractive behaviorally. AN1's responses at threshold were also tuned to the dominant carrier frequencies of the male's CS. J. Exp. Zool. 303A:377–392, 2005. © 2005 Wiley‐Liss, Inc.
Different somatostatin receptor subtypes are operating in the brain of the teleost fish, Coris julis
Authors: Madeo Maria , Giusi Giuseppina , Aló Raffaella , Facciolo Rosa Maria , Carelli Antonio , Canonaco Marcello
Published: April 2005

Characterization of somatostatinergic (sst) neuronal activity through the application of nonpeptidyl agonists L‐779,976 and L‐817,818 which are highly specific for the sst receptors (sstr) sstr2 and sstr5, respectively, shows for the first time that sstr2, 5‐like subtypes are the two major sstr subtypes operating in the brain of the teleost sea wrasse, Coris julis. A somewhat high but heterogeneous distribution pattern (>30<180 fmol/mg wet tissue weight) of neurons expressing sstr2, 5was reported in the different diencephalic regions plus in mesencephalon and telencephalon while low values were obtained in the cerebellum. Application of the above nonpeptidyl agonists permitted us to identify sstr2‐like as the predominant subtype in telencephalic areas such as the entopeduncular nucleus (E) and postcommissural nucleus of the ventral telencephalon (Vp) as well as in hypothalamic and thalamic areas. At the same time high levels of neurons expressing sstr5‐like, that greatly overlap those of sstr2‐like in the diencephalic areas such as the anteroventral part of the preoptic nucleus (NPOav), the dorsal habenular nucleus (NHd) and the ventrolateral thalamic nucleus (VL), indicate that sstr2‐like is very likely not the only sstr subtype acting in this fish brain. The predominance of sstr5‐like in other brain areas is confirmed by the high quantities of this subtype in mesencephalic areas such as the torus longitudinalis (TLo). Overall, the discriminately differing densities of neurons expressing both subtypes seem to point to this system as a key molecular basis accounting for the distinct neurophysiological and behavioral sst‐dependent activities in Coris julis. J. Exp. Zool. 303A:406–413, 2005. © 2005 Wiley‐Liss, Inc.
NP‐completeness of list coloring and precoloring extension on the edges of planar graphs
Authors: Marx Dániel
Published: April 2005

In the edge precoloring extension problem, we are given a graph with some of the edges having preassigned colors and it has to be decided whether this coloring can be extended to a proper k‐edge‐coloring of the graph. In list edge coloring every edge has a list of admissible colors, and the question is whether there is a proper edge coloring where every edge receives a color from its list. We show that both problems are NP‐complete on (a) planar 3‐regular bipartite graphs, (b) bipartite outerplanar graphs, and (c) bipartite series‐parallel graphs. This improves previous results of Easton and Parker 6, and Fiala 8. © 2005 Wiley Periodicals, Inc. J Graph Theory 49: 313–324, 2005
Computation of conformational entropy from protein sequences using the machine‐learning method—Application to the study of the relationship between structural conservation and local structural stability
Authors: Huang Shao‐Wei , Hwang Jenn‐Kang
Published: April 2005

A complete protein sequence can usually determine a unique conformation; however, the situation is different for shorter subsequences—some of them are able to adopt unique conformations, independent of context; while others assume diverse conformations in different contexts. The conformations of subsequences are determined by the interplay between local and nonlocal interactions. A quantitative measure of such structural conservation or variability will be useful in the understanding of the sequence–structure relationship. In this report, we developed an approach using the support vector machine method to compute the conformational variability directly from sequences, which is referred to as the sequence structural entropy. As a practical application, we studied the relationship between sequence structural entropy and the hydrogen exchange for a set of well‐studied proteins. We found that the slowest exchange cores usually comprise amino acids of the lowest sequence structural entropy. Our results indicate that structural conservation is closely related to the local structural stability. This relationship may have interesting implications in the protein folding processes, and may be useful in the study of the sequence–structure relationship. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Crystal structure of a calcium‐induced dimer of two isoforms of cobra phospholipase A2 at 1.6 Å resolution
Authors: Jabeen T. , Sharma S. , Singh N. , Singh R. K. , Kaur P. , Perbandt M. , Betzel Ch. , Srinivasan A. , Singh T. P.
Published: April 2005

The calcium‐induced formation of a complex between two isoforms of cobra venom phospholipase A2 reveals a novel interplay between the monomer–dimer and activity–inactivity transitions. The monodispersed isoforms lack activity in the absence of calcium ions while both molecules gain activity in the presence of calcium ions. At concentrations higher than 10 mg/ml, in the presence of calcium ions, they dimerize and lose activity again. The present study reports the crystal structure of a calcium‐induced dimer between two isoforms of cobra phospholipase A2. In the complex, one molecule contains a calcium ion in the calcium binding loop while the second molecule does not possess an intramolecular calcium ion. However, there are two calcium ions per dimer in the structure. The second calcium ion is present at an intermolecular site and that is presumably responsible for the dimerization. The calcium binding loops of the two molecules adopt strikingly different conformations. The so‐called calcium binding loop in the calcium‐containing molecule adopts a normal conformation as generally observed in other calcium containing phospholipase A2 enzymes while the conformation of the corresponding loop in the calcium free monomer deviates considerably with the formation of a unique intraloop Gly33 (N)Cys27 (O) = 2.74 Å backbone hydrogen bond. The interactions of Arg31 (B) with Asp49 (A) and absence of calcium ion are responsible for the loss of catalytic activity in molecule A while interactions of Arg2 (B) with Tyr52 (B) inactivate molecule B. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Estimation of temperature‐dependent lower flammability limit of pure organic compounds in air at atmospheric pressure
Authors: Catoire Laurent , Naudet Valérie
Published: April 2005

An equation is proposed for the accurate and user‐friendly estimation of the lower flammability limit (LFL) of C/H, C/H/N, C/H/O, C/H/O/N, and monohalogenated organic pure compounds in air at atmospheric pressure in the 25–400° C temperature range. The equation derived in this study used 40 chemicals (LFLs) for the derivation and over 200 for the validation. Comparisons between experimental data and estimated data show that the average absolute deviation is <10%, and that deviations ≥20% are exceptions. This derived equation was validated and then used to identify erroneous LFLs in the literature. We found that LFLs are in error for 10 compounds out of the 300 examined. The equation developed in this paper is compared with that developed by Britton and both equations are found to be generally consistent. Advantages and disadvantages of both equations are discussed. © 2005 American Institute of Chemical Engineers Process Saf Prog, 2005
Transduodenal Resection of Peri‐Ampullary Lesions
Authors: Dixon Elijah , Vollmer Charles M. , Sahajpal Ajay , Cattral Mark S. , Grant David R. , Taylor Bryce R. , Langer Bernard , Gallinger Steven , Greig Paul D.
Published: April 2005

Transduodenal resection (TDR) of lesions near the ampulla of Vater is an alternative to the Whipple pancreaticoduodenectomy. A retrospective analysis was performed to determine the long‐term outcome and the utility of intraoperative frozen section examinations in aiding operative decision making in patients undergoing TDR. From 1992 to 2002, 19 patients with an average age of 64.2 years (range: 33–84 years) underwent a transduodenal resection of a peri‐ampullary lesion; median follow‐up was 47 months (range: 2–100 months). Pathology of the lesions was as follows: 11 with benign ampullary adenomas, including 4 with familial adenomatous polyposis (FAP); 7 with peri‐ampullary adenocarcinomas; and 1 with a benign stricture. Survival for the entire cohort is 100%. In 12 cases an intraoperative frozen section was performed. The specificity and positive predictive value of the intraoperative histology were both 100%, and the sensitivity and negative predictive value were 57% and 38%, respectively. Three of the 4 patients with FAP have recurrent adenomatous change; 2 of the 7 with carcinoma have metastatic adenocarcinoma. Transduodenal resection of peri‐ampullary lesions appears to be a safe alternative to radical resection for benign adenomas and selected carcinoma. Intraoperative frozen section assessment is recommended in cases of potential adenocarcinoma.
Hemodynamic and Respiratory Effects of Robot‐assisted Laparoscopic Fundoplication in Children
Authors: Meininger Dirk , Byhahn Christian , Mierdl Stephan , Lehnert Mark , Heller Klaus , Zwissler Bernhard , Bremerich Dorothee H.
Published: April 2005

Laparoscopic fundoplication is increasingly used for treating gastro‐esophageal reflux disease in children. Mechanical and pharmacological effects may contribute to hemodynamic and respiratory changes during carbon dioxide pneumoperitoneum. The aim of the present study was to evaluate the hemodynamic and respiratory effects of pneumoperitoneum (PP) with an intra‐abdominal pressure (IAP) of 12 mmHg in children undergoing robot‐assisted laparoscopic fundoplication during total intravenous anesthesia. Ten children, aged 8–16 years, American Society of Anesthesiologists physical status II–III, scheduled for robot‐assisted laparoscopic fundoplication in the reverse Trendelenburg position were investigated. Minute ventilation (MV), peak inspiratory pressure (PIP), IAP, heart rate (HR), mean arterial blood pressure (MAP) were recorded, together with pH, base excess, HCO3−, PetCO2, PaCO2, and PaO2 at six time points: before insufflation, 10, 30, 60, 90 minutes after creating PP and after desufflation. The IAP was maintained at 12 mmHg. During insufflation MAP increased significantly from 70.6 (±9.0) to 84.8 (±10.4) mmHg, MV was increased from 4.6 (±0.8) to 5.5 (±0.9) lmin−1, PIP increased, PaO2 and pH decreased. PetCO2 increased from 33.1 (±1.6) to 36.6 (±1.6) mmHg together with PaCO2. Hemodynamic and respiratory effects due to the intra‐abdominal insufflation of CO2 with an IAP of 12 mmHg are well tolerated, and anesthesia with remifentanil, propofol and mivacurium facilitates extubation immediately at the end of surgery.
How to Appraise the Effectiveness of Treatment
Authors: Bhandari Mohit , Haynes R. Brian
Published: April 2005

Before implementing a new therapy, we should ascertain the benefits and risks of the therapy and assure ourselves that the resources consumed during the intervention will not be exorbitant. In the hierarchy of research designs, the results of randomized controlled trials, especially if systematically reviewed, are considered the highest level of evidence. We suggest a three‐step approach to using an article from the medical literature to guide your patient care. We recommend that readers ask whether the study can provide valid results, review the results, and consider how the results can be applied to patient care. Given the time constraints of busy surgical practices and surgical training programs, applying this analysis to every relevant article will be challenging. However, the basis of this process is essentially what we all do many times each week when making decisions about whether and how to treat patients. Making this process explicit with guidelines to assess the strength of the available evidence can serve to improve patient care. It also allow us to defend therapeutic interventions based on available evidence and not anecdote.
Factors contributing to the seasonal occurrence of the willow leaf beetle Plagiodera versicolora
Authors: Egusa Sawako , Nishida Takayoshi , Fujisaki Kenji , Sawada Hiroichi
Published: April 2005

We conducted a 3‐year study of a natural population of the willow leaf beetle Plagiodera versicolora (Coleoptera: Chrysomelidae) on a river bank of the Inukami River, Shiga, central Japan, where four willow species (Salix chaenomeloides, S. eriocarpa, S. integra, and S. serissaefolia) occur sympatrically. Our survey showed that: (1) at the study site, the abundance of P. versicolora greatly varied among years and among willow species; (2) adult abundance changed seasonally with species‐specific patterns on different willow species; and (3) the dispersal‐settlement of adults had the most pronounced effects on the seasonal population growth rate of P. versicolora. Factors affecting these results were discussed.
SHOW: A Computerized System for Guiding Manual Sample Handling
Authors: Du Ping
Published: April 2005

Despite advances in laboratory automation, many sample handling tasks remain a manual process. SHOW (Sample Handling Operation Wizard) is a computerized system developed to guide manual sample handling. It consists of an illumination station equipped with a flat panel computer monitor, a sample tray holding up to four microtiter plates and up to eight vials, and a computer installed with custom software. The sample tray, loaded with plates and vials, is placed on the illumination station, which displays images of wells and vials directly below. Plate format can be set by the user to fit 24-, 48-, 96-, or 384-well plates. By illuminating the wells or vials involved in a sample handling step of a predefined protocol, manual operations can be performed with precise guidance from the system, and sample properties or experimental data can be recorded by clicking on the corresponding well images. As a result, the risk of locating a wrong sample or placing a sample at a wrong location is minimized, and sample handling operations become more efficient and less stressful.
Children's Participation in Social Policy: Inclusion, Chimera or Authenticity?
Authors: Cockburn Tom
Published: April 2005

This paper explores the recent plethora of commitments by government to include children in social policy decision making in the UK. The participation of children is located in the tensions between children perceived as competent and/or incompetent that underlies the ambiguities of children's participation. The paper examines the ways participation, power and empowerment can be used in the context of children. The paper looks at children’s civic engagement and suggests that the participation of children is difficult with the ways representative governments operate in a liberal democracy today, but ends with some suggested ways forward.
New Labour's Approach to the Voluntary Sector: Independence and the Meaning of Partnership
Authors: Lewis Jane
Published: April 2005

A major problem for voluntary organisations service providers under contract has been their independence in regard to both the relatively narrow issue of the terms and conditions of service provision, and the broader issue about the part voluntary organisations might play in policy shaping and democratic renewal. I examine the way in which New Labour has developed its ‘partnership’ approach to the voluntary sector since 1998. I argue that better terms and conditions have been secured for voluntary organisations providing services, and that large and umbrella organisations now have more impact on the implementation of central government policy. However, the more equal partnership required for a policy-shaping role in the sense of agenda-setting is likely to remain elusive, while at the local level there are tensions between the idea of voluntary organisations as agents of ‘civil renewal’ and as service providers.
Die Erfassung des Entwicklungsniveaus epistemologischer Überzeugungen und das Problem der Übertragbarkeit von Interviewverfahren in standardisierte Fragebogenmethoden
Authors: Krettenauer Tobias
Published: April 2005

Zusammenfassung. Es wird untersucht, inwieweit die von Rest (1979) im Bereich der Moralentwicklung erprobte Strategie der Übersetzung von Interviewmethoden in Fragebogenverfahren auf andere Bereiche entwicklungspsychologischer Forschung übertragbar ist. Hierfür wird ein neu entwickelter Fragebogen zur Erfassung des Entwicklungsniveaus epistemologischer Überzeugungen (FREE) vorgestellt, der auf vergleichbaren Konstruktionsprinzipien beruht wie der Defining Issues Test (DIT). Für diesen Fragebogen werden Reliabilitäts- und Validitätskennwerte ermittelt. Quer- und längsschnittliche Analysen weisen eine ausreichende Sensitivität des FREE gegenüber Alters- und Bildungseffekten nach. Zudem ergab sich eine hohe korrelative Übereinstimmung von Fragebogen- und Interviewdaten. Eine deutliche Differenz zwischen beiden Methoden zeigte sich jedoch bei der Einschätzung des absoluten Kompetenzniveaus der Befragten. Die Ergebnisse entsprechen weitgehend den Befunden im Bereich der Moralentwicklung und sprechen für die Generalisierbarkeit der Übertragungsstrategie. Der FREE empfiehlt sich folglich dann als Alternative zu Interviewverfahren, wenn bei der Untersuchung des Entwicklungsniveaus epistemologischer Überzeugungen interindividuelle Unterschiede und nicht das absolute Kompetenzniveau im Vordergrund stehen.
Fragen und Erklärungen beim kooperativen Lernen in Grundschulklassen
Authors: Kronenberger Julia , Souvignier Elmar
Published: April 2005

Zusammenfassung. Anhand von Videoanalysen wurde das Elaborationsverhalten von Drittklässlern in kooperativen Kleingruppen untersucht. Weiterhin wurde geprüft, ob eine Optimierung der Gruppenarbeit durch ein zusätzliches Fragetraining gelingt. Als Indikatoren für elaborative Prozesse wurden das Frage- und Erklärverhalten während der Gruppenarbeit herangezogen. An drei Grundschulen erarbeiteten jeweils zwei Parallelklassen (N = 138) vier sechsstündige Unterrichtseinheiten in der kooperativen Unterrichtsmethode des Gruppenpuzzles, wobei jeweils eine Klasse pro Schule das zusätzliche Fragetraining erhielt. Es zeigte sich, dass das Elaborationsniveau bei Fragen und Erklärungen recht niedrig ausfiel. Menge und Niveau der gestellten Fragen konnten durch das Fragetraining nur in Phasen gegenseitiger Wissensvermittlung verbessert werden. In Phasen gleichberechtigter gemeinsamer Wissenserarbeitung sowie in Bezug auf die Güte der Erklärungen konnte kein Trainingseffekt festgestellt werden. Trotz der eher geringen elaborativen Kompetenzen der Drittklässler scheint der Einsatz einer komplexen kooperativen Lernform schon in dieser Klassenstufe möglich. Auffällig ist, dass in Phasen gegenseitiger Wissensvermittlung spontan helfende (“didaktische“) Fragen formuliert wurden - die Kinder übernahmen also durchaus ihre Rolle als Lehrende.
Natural arsenic contamination of Holocene alluvial aquifers by linked tectonic, weathering, and microbial processes
Authors: Saunders J. A. , Lee M.‐K. , Uddin A. , Mohammad S. , Wilkin Richard T. , Fayek Mostafa , Korte Nic E.
Published: April 2005

Linked tectonic, geochemical, and biologic processes lead to natural arsenic contamination of groundwater in Holocene alluvial aquifers, which are the main threat to human health around the world. These groundwaters are commonly found a long distance from their ultimate source of arsenic, where chemical weathering of As‐bearing minerals occurs. We propose a “GBH‐As” model that ties together all of the important tectonic, biologic, and hydrologic processes that cause natural As release in groundwater in Holocene terrestrial deposits. Processes highlighted by the “GBH‐As” model can explain the movement of arsenic from lithosphere to hydrosphere. However, we propose a factor that has increased dissolved As concentrations in Holocene aquifers to levels where human health is threatened: mechanical weathering associated with Pleistocene glaciation. Our model invokes erosion of mountain belts aided by glaciers, transport of arsenic by surface waters, adsorption of As by stream sediments, and deposition of stream sediments and organic matter in alluvial deposits. Subsequently, Fe(III)‐reducing bacteria present in alluvial aquifers cause the release of sorbed As to groundwater under moderately reducing conditions.
Sensitivity of satellite microwave and infrared observations to soil moisture at a global scale: Relationship of satellite observations to in situ soil moisture measurements
Authors: Prigent Catherine , Aires Filipe , Rossow William B. , Robock Alan
Published: April 2005

This study presents a systematic and integrated analysis of the sensitivity of the available satellite observations to in situ soil moisture measurements. Although none of these satellites is optimized for land surface characterization, before the launches of the SMOS‐ and HYDROS‐dedicated missions they are the only potential sources of global soil moisture measurements. The satellite observations include passive microwave emissivities, active microwave scatterometer data, and infrared estimates of the diurnal amplitude of the surface skin temperature. The Global Soil Moisture Data Bank provides in situ soil moisture measurements in five separate regions. This simultaneous analysis of various satellite observations and the large amount of in situ measurements has two major advantages. First, this analysis helps identify and separate the physical mechanisms that affect the satellite observations. For example, we show that the passive microwave polarization differences at 19 GHz and above are essentially sensitive to the vegetation and not to the soil moisture (i.e., the correlation between microwave observations and soil moisture is only indirect and comes from the statistical correlation between vegetation and soil moisture). Second, this analysis enables an objective comparison of the relative potential of the various satellite observations for soil moisture retrieval when other conditions are held constant. The second part of this study benefits from this synthesis to derive a relationship between satellite observations and soil moisture at a global scale.
Potential of Advanced Microwave Sounding Unit‐A (AMSU‐A) and AMSU‐B measurements for atmospheric temperature and humidity profiling over land
Authors: Karbou Fatima , Aires Filipe , Prigent Catherine , Eymard Laurence
Published: April 2005

A neural network retrieval method has been applied to investigate AMSU‐A/AMSU‐B atmospheric temperature and humidity profiling capabilities over land. The retrieval method benefits from a reliable estimate of the land emissivity and skin temperature as well as first guess information regarding the temperature‐humidity profiles. It has been applied on a large geographic area (60°W–60°E, 60°S–60°N) and atmospheric situations (winter and summer). The retrieved RMS errors are within 2 K and 9% in temperature and relative humidity, respectively. Regardless of scanning conditions, vegetation types, and atmospheric situations, the algorithm retrieval results are satisfactory for both temperature and relative humidity. The retrieval approach has been evaluated by comparison with available in situ measurements.
Precursory accelerating seismic moment release (AMR) in a synthetic seismicity catalog: A preliminary study
Authors: Robinson Russell , Zhou Shiyong , Johnston Steven , Vere‐Jones David
Published: April 2005

A power‐law like acceleration of seismic moment release (AMR) has been proposed as a precursor to large earthquakes. Because of problems with real‐world data, we have used a synthetic seismicity model of 256 interacting faults embedded in a 3‐D elastic half‐space to search for periods of AMR preceding the largest events (Mw ∼ 7.1). In only 5 of 18 cases does the AMR model fit the data significantly better than a linear moment release, and then only weakly so. This proportion, or higher, occurs in 8% of 1000 randomized catalogs. We conclude that either AMR is unlikely to be a common precursor, or that factors contributing to the AMR pattern in the real world are missing from the synthetic model.
Thermal properties of the metastable supersaturated vapor of the Lennard-Jones fluid
Authors: Linhart Andreas , Chen Chin-Cheng , Vrabec Jadran , Hasse Hans
Published: April 2005

p , ρ, T data of the supersaturated vapor of the Lennard-Jones fluid are obtained by molecular dynamics simulations. The metastable state points are identified before a phase separation takes place. An estimation of the location of the spinodal is given. The results are compared to two theoretically based equations of state and one empirical equation of state which was parametrized also taking into account metastable state points. The pressure obtained by simulation is found to be lower than that from both theoretically based equations of state, which do not account for the inhomogeneous density distribution of the supersaturated vapor.
Appraisal of the performance of nonhybrid density functional methods in characterization of the Al4C molecule
Authors: Zubarev Dmitry Yu. , Boldyrev Alexander I.
Published: April 2005

In three recent publications it was predicted that an Al4C molecule is planar on the basis of nonhybrid density functional calculations. These conclusions contradict our earlier predictions that Al4C is tetrahedral. In order to resolve the controversy we probed in this paper a potential energy surface of Al4C using a large variety of theoretical methods including multiconfigurational methods and a variety of one-electron basis sets. We confirmed that the nonhybrid Becke’s exchange with Perdew–Wang 1991 correlation functional density functional method predicts that Al4C has a planar structure in agreement with the reports of the other three groups. However, in this paper we have shown that high level ab initio calculations at the coupled cluster with singles, doubles, and noniterative triples and at the complete active space self-consistent field followed by multireference configurational interaction levels of theory confirm our earlier prediction that Al4C is indeed tetrahedral. The failure of nonhybrid density functional methods to correctly characterize the global minimum structure of Al4C demonstrates that it is dangerous to rely solely on these density functional methods in characterization of new molecules and clusters, where experimental structure is not known.
Comparison of efficiency and bias of free energies computed by exponential averaging, the Bennett acceptance ratio, and thermodynamic integration
Authors: Shirts Michael R. , Pande Vijay S.
Published: April 2005

Recent work has demonstrated the Bennett acceptance ratio method is the best asymptotically unbiased method for determining the equilibrium free energy between two end states given work distributions collected from either equilibrium and nonequilibrium data. However, it is still not clear what the practical advantage of this acceptance ratio method is over other common methods in atomistic simulations. In this study, we first review theoretical estimates of the bias and variance of exponential averaging (EXP), thermodynamic integration (TI), and the Bennett acceptance ratio (BAR). In the process, we present a new simple scheme for computing the variance and bias of many estimators, and demonstrate the connections between BAR and the weighted histogram analysis method. Next, a series of analytically solvable toy problems is examined to shed more light on the relative performance in terms of the bias and efficiency of these three methods. Interestingly, it is impossible to conclusively identify a “best” method for calculating the free energy, as each of the three methods performs more efficiently than the others in at least one situation examined in these toy problems. Finally, sample problems of the insertion/deletion of both a Lennard-Jones particle and a much larger molecule in TIP3P water are examined by these three methods. In all tests of atomistic systems, free energies obtained with BAR have significantly lower bias and smaller variance than when using EXP or TI, especially when the overlap in phase space between end states is small. For example, BAR can extract as much information from multiple fast, far-from-equilibrium simulations as from fewer simulations near equilibrium, which EXP cannot. Although TI and sometimes even EXP can be somewhat more efficient in idealized toy problems, in the realistic atomistic situations tested in this paper, BAR is significantly more efficient than all other methods.