bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intramolecular C–H and C–O Bond Activation of Dimethylplatinum(II) Complexes Having the PN Ligand
Authors: Kataoka Yasutaka , Nakamura Tatsuya , Tani Kazuhide 
Published: December 2002

Abstract
Reaction of (cod)PtMe2 with 1 equiv and 2 equiv of the PN ligand (PN = o-Ph2PC6H4CH2OCH2C5H4N-2) (1) gave cis-(PN-κP:κN)PtMe2 (2) and cis-(PN-κP)2PtMe2 (3) respectively. The complex 2 underwent activation of the benzylic C–H bond in toluene at 110 °C to afford (PCN-κP:κC:κN)PtMe (4). Toluene solution of 3 was refluxed for 42 h in the presence of 2 equiv of the PN ligand to afford the C–O bond cleavage product cis-(PN-κP)(Ph2PC6H4CH2-κP:κC)PtMe (cis-5) along with cis-(PN-κP)(PCN-κP:κC)PtMe (cis-6).
Electron Transport across Vesicle Bilayers Sensitized by Pyrenes: Design and Syntheses of Unsymmetrically Substituted Bifunctional Pyrenes Acting as Excellent Sensitizers
Authors: Yoshida Asako , Harada Akitomo , Mizushima Tadashi , Murata Shigeru 
Published: December 2002

Abstract
An electron transport from an electron donor entrapped into inner waterpool to an electron acceptor in outer aqueous solution across vesicle bilayers was sensitized by pyrene derivatives incorporated in the vesicle walls, although the sensitizer ability was very dependent on the substituent group on the pyrenyl ring. The newly designed pyrenes having both a hydrophilic group linked by short methylene chain and a hydrophobic long alkyl group were found to act as excellent sensitizers.
Efficient Ring Opening Reactions of N-Tosyl Aziridines with Amines and Water in Presence of Catalytic Amount of Cerium(IV) Ammonium Nitrate
Authors: Chakraborty Tushar K , Ghosh Animesh , Raju T Venugopal 
Published: December 2002

Abstract
While methyl- and benzylamines opened N-tosyl aziridines 1 very efficiently in acetonitrile with complete regio- and stereoselectivity to give the corresponding diamines 2 and 3, respectively, in excellent yields, similar openings with water could only be achieved in the presence of a catalytic amount of cerium(IV) ammonium nitrate under very mild conditions furnishing the amino alcohols 4.
Hydrogen-bonded Macrocluster Formation of Ethylene Glycol on Silica Surfaces in Ethylene Glycol-Cyclohexane Binary Liquids
Authors: Kurihara Kazue , Nakagawa Yasuhiro , Mizukami Masashi 
Published: December 2002

Abstract
Adsorption of ethylene glycol on silica surfaces was investigated in cyclohexane. A long-range attraction appeared between the silica surfaces in the presence of ethylene glycol (&gt;0.0005 mol%). ATR-FTIR spectra exhibited an absorption band at 3600–3000 cm−1, ascribed to the hydrogen-bonded hydroxyl groups. The results demonstrated that ethylene glycol adsorbed on the silica surfaces in a thick layer of several tens nm where it formed hydrogen-bonded molecular macroclusters.
Helical Assembly Formed by Chiral [11]Thiaheterohelicene Molecules in Crystals. Architecture with Triple Helix
Authors: Nakagawa Hiroko , Yoshino Jun , Yamada Koh-ichi , Shiro Motoo 
Published: December 2002

Abstract
Projection of the crystal structure of a P enantiomer of [11]thiaheterohelicene (11TH) with a helical structure of one and a half turns along the a axis revealed huge helical assemblies, in which three crystallographically independent molecules formed a smaller right-handed helix, no similar helical assembly being observed for the crystal structures of an 11TH racemate and a [9]thiaheterohelicene enantiomer.
Visible Light-induced Cationic Polymerization of Epoxides Sensitized by Benzoquinonylsulfanyl Derivatives
Authors: Suyama Kanji , Qu Weihong , Shirai Masamitsu , Tsunooka Masahiro 
Published: December 2002

Abstract
On irradiation with visible light, cationic polymerization of epoxides by a photoacid generator (PAG) was sensitized by benzoquinonylsulfanyl derivatives. Spectral analyses suggest that the reduction of the quinone derivatives on irradiation was the initial and essential step of the polymerization.
Extraction of Cd(II) and Zn(II) with Dialkylthiophosphinic Acid and Hexadentate Nitrogen-donor Ligand
Authors: Takeshita Kenji , Watanabe Kunio , Nakano Yoshio , Watanabe Masayuki 
Published: December 2002

Abstract
The extraction equilibrium of Cd(II) and Zn(II) with a commercial extractant, Cyanex 301, and an aqueous complexing agent, TPEN [N,N,N′,N′-tetrakis(2-pyridylmethyl)-1,2-ethanediamine] was measured. When TPEN in amounts equimolar with heavy metal (Cd or Zn) was added in the aqueous solution, only the extraction of Zn was depressed. Then, the extraction constant of Cd was little changed and that of Zn was decreased to about 10−4 times. TPEN acts as a strong masking agent for Zn.
Ru(bpy)33+ Electrochemiluminescence Detection of Aliphatic and Aromatic Amines with Diketene
Authors: Uchikura Kazuo 
Published: December 2002

Abstract
A new derivatization method for the detection of aliphatic and aromatic amines, based on electro-chemiluminescence (ECL) with Ru(bpy)32+ is proposed. Sample amines were derivatized to acetoacetylamide-type derivatives using diketene. The derivatives were detected by reversed-phase HPLC with ECL detection using Ru(bpy)32+.
Molecular determinants of glucagon receptor signaling
Authors: Unson Cecilia G. 
Published: December 2002

AbstractA 29‐amino acid polypeptide hormone, glucagon has been one of the most prolific models in the study of hormone action. The key biologic function of glucagon is to counterbalance the actions of insulin and maintain a normal level of serum glucose. Diabetes mellitus can thus be considered a bihormonal disorder with an excess of glucagon contributing to the hyperglycemic state. The effects of glucagon are mediated by the glucagon receptor, which is itself a prototypical member of a distinct category called family B receptors within the G protein‐coupled superfamily of seven‐helical transmembrane receptors (GPCRs). At the structural level, the peptide ligands of family B receptors are highly homologous, in particular in the N‐terminal region of the molecules. The mechanism by which highly homologous peptide ligands selectively recognize their receptors involves distinct molecular interactions that are gradually being elucidated. This review focuses on structural determinants of the glucagon receptor that are important for its activity with respect to interaction with its ligand and G proteins. Information about the glucagon receptor is presented within the context of what is known about other members of the family B GPCRs. © 2002 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 66: 218–235, 2002
Mode of action of membrane active antimicrobial peptides
Authors: Shai Yechiel 
Published: December 2002

AbstractWater‐membrane soluble protein and peptide toxins are used in the defense and offense systems of all organisms, including plants and humans. A major group includes antimicrobial peptides, which serve as a nonspecific defense system that complements the highly specific cell‐mediated immune response. The increasing resistance of bacteria to conventional antibiotics stimulated the isolation and characterization of many antimicrobial peptides for potential use as new target antibiotics. The finding of thousands of antimicrobial peptides with variable lengths and sequences, all of which are active at similar concentrations, suggests a general mechanism for killing bacteria rather than a specific mechanism that requires preferred active structures. Such a mechanism is in agreement with the “carpet model” that does not require any specific structure or sequence. It seems that when there is an appropriate balance between hydrophobicity and a net positive charge the peptides are active on bacteria. However, selective activity depends also on other parameters, such as the volume of the molecule, its structure, and its oligomeric state in solution and membranes. Further, although many studies support that bacterial membrane damage is a lethal event for bacteria, other studies point to a multihit mechanism in which the peptide binds to several targets in the cytoplasmic region of the bacteria.
Structure and function of membrane fusion peptides
Authors: Tamm Lukas K. , Han Xing , Li Yinling , Lai Alex L. 
Published: December 2002

AbstractMembrane fusion peptides are highly conserved hydrophobic domains of fusion proteins that insert into membranes during membrane fusion. Recent success with solving the structures of the influenza hemagglutinin fusion peptide and some critical mutants of this peptide in membrane environments at high resolution has led to a new understanding of the mechanism of membrane fusion. This review highlights the structures that have been solved and summarizes recent thermodynamic and spectroscopic studies on the interactions of this interesting class of peptides with lipid bilayers. © 2002 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 66: 249–260, 2002
Use of confocal microscopy to follow the development of penetrative hyphae during growth of Rhizopus oligosporus in an artificial solid‐state fermentation system
Authors: Nopharatana Montira , Mitchell David A. , Howes Tony 
Published: December 2002

AbstractTwo methods were compared for determining the concentration of penetrative biomass during growth of Rhizopus oligosporus on an artificial solid substrate consisting of an inert gel and starch as the sole source of carbon and energy. The first method was based on the use of a hand microtome to make sections of approximately 0.2‐ to 0.4‐mm thickness parallel to the substrate surface and the determination of the glucosamine content in each slice. Use of glucosamine measurements to estimate biomass concentrations was shown to be problematic due to the large variations in glucosamine content with mycelial age. The second method was a novel method based on the use of confocal scanning laser microscopy to estimate the fractional volume occupied by the biomass. Although it is not simple to translate fractional volumes into dry weights of hyphae due to the lack of experimentally determined conversion factors, measurement of the fractional volumes in themselves is useful for characterizing fungal penetration into the substrate. Growth of penetrative biomass in the artificial model substrate showed two forms of growth with an indistinct mass in the region close to the substrate surface and a few hyphae penetrating perpendicularly to the surface in regions further away from the substrate surface. The biomass profiles against depth obtained from the confocal microscopy showed two linear regions on log–linear plots, which are possibly related to different oxygen availability at different depths within the substrate. Confocal microscopy has the potential to be a powerful tool in the investigation of fungal growth mechanisms in solid‐state fermentation. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 81: 438–447, 2003.
Enrichment of denitrifying glycogen‐accumulating organisms in anaerobic/anoxic activated sludge system
Authors: Zeng Raymond J. , Yuan Zhiguo , Keller Jürg 
Published: December 2002

AbstractDenitrifying glycogen‐accumulating organisms (DGAO) were successfully enriched in a lab‐scale sequencing batch reactor (SBR) running with anaerobic/anoxic cycles and acetate feeding during the anaerobic period. Acetate was completely taken up anaerobically, which was accompanied by the consumption of glycogen and the production of poly‐β‐hydroxy‐alkanoates (PHA). In the subsequent anoxic stage, nitrate or nitrite was utilized as electron acceptor for the oxidation of PHA, resulting in glycogen replenishment and cell growth. The above phenotype showed by the enrichment culture demonstrates the existence of DGAO. Further, it was found that the anaerobic behavior of DGAO could be predicted well by the anaerobic GAO model of Filipe et al. (2001) and Zeng et al. (2002a). The final product of denitrification during anoxic stage was mainly nitrous oxide (N2O) rather than N2. The data strongly suggests that N2O production may be caused by the inhibition of nitrous oxide reductase by an elevated level of nitrite accumulated during denitrification. The existence of these organisms is a concern in biological nutrient removal systems that typically have an anaerobic/anoxic/aerobic reactor sequence since they are potential competitors to the polyphosphate‐accumulating organisms. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 81: 397–404, 2003.
Development of a novel titration and off‐gas analysis (TOGA) sensor for study of biological processes in wastewater treatment systems
Authors: Pratt Steven , Yuan Zhiguo , Gapes Daniel , Dorigo Marco , Zeng Raymond J. , Keller Jurg 
Published: December 2002

AbstractThe development of the new TOGA (titration and off‐gas analysis) sensor for the detailed study of biological processes in wastewater treatment systems is outlined. The main innovation of the sensor is the amalgamation of titrimetric and off‐gas measurement techniques. The resulting measured signals are: hydrogen ion production rate (HPR), oxygen transfer rate (OTR), nitrogen transfer rate (NTR), and carbon dioxide transfer rate (CTR). While OTR and NTR are applicable to aerobic and anoxic conditions, respectively, HPR and CTR are useful signals under all of the conditions found in biological wastewater treatment systems, namely, aerobic, anoxic and anaerobic. The sensor is therefore a powerful tool for studying the key biological processes under all these conditions. A major benefit from the integration of the titrimetric and off‐gas analysis methods is that the acid/base buffering systems, in particular the bicarbonate system, are properly accounted for. Experimental data resulting from the TOGA sensor in aerobic, anoxic, and anaerobic conditions demonstrates the strength of the new sensor. In the aerobic environment, carbon oxidation (using acetate as an example carbon source) and nitrification are studied. Both the carbon and ammonia removal rates measured by the sensor compare very well with those obtained from off‐line chemical analysis. Further, the aerobic acetate removal process is examined at a fundamental level using the metabolic pathway and stoichiometry established in the literature, whereby the rate of formation of storage products is identified. Under anoxic conditions, the denitrification process is monitored and, again, the measured rate of nitrogen gas transfer (NTR) matches well with the removal of the oxidised nitrogen compounds (measured chemically). In the anaerobic environment, the enhanced biological phosphorus process was investigated. In this case, the measured sensor signals (HPR and CTR) resulting from acetate uptake were used to determine the ratio of the rates of carbon dioxide production by competing groups of microorganisms, which consequently is a measure of the activity of these organisms. The sensor involves the use of expensive equipment such as a mass spectrometer and requires special gases to operate, thus incurring significant capital and operational costs. This makes the sensor more an advanced laboratory tool than an on‐line sensor. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 81: 482–495, 2003.
A mechanistic model of photosynthesis in microalgae
Authors: Rubio F. Camacho , Camacho F. García , Sevilla J. M. Fernández , Chisti Y. , Grima E. Molina 
Published: December 2002

AbstractA dynamic model of photosynthesis is developed, accounting for factors such as photoadaptation, photoinhibition, and the “flashing light effect.” The model is shown to explain the reported photosynthesis–irradiance responses observed under various conditions (constant low light, constant intense irradiance, flashing light, diurnal variation in irradiance). As significant distinguishing features, the model assumes: (1) The stored photochemical energy is consumed in an enzyme‐mediated process that obeys Michaelis‐Menten kinetics; and (2) photoinhibition has a square‐root dependence on irradiance. Earlier dynamic models of photosynthesis assumed a first‐order dependence of photoinhibition on irradiance and different kinetics of consumption of the stored energy than used in this work. These earlier models could not explain the photosynthesis—irradiance behavior under the full range of irradiance scenarios—a shortcoming that is overcome in the model developed in this work. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 81: 459–473, 2003.
Maximization of hydrogen production ability in high‐density suspension of Rhodovulum sulfidophilum cells using intracellular poly(3‐hydroxybutyrate) as sole substrate
Authors: Maeda Isamu , Miyasaka Hitoshi , Umeda Fusako , Kawase Masaya , Yagi Kiyohito 
Published: December 2002

AbstractGrowth of and hydrogen production by wild‐type (WT) Rhodovulum sulfidophilum were compared with those by one of its mutants lacking the poly(3‐hydroxybutyrate) (PHB) biosynthesis ability (PNM2). During phototrophic growth under aerobic conditions with fixed illumination, changes in the extinction coefficient and PHB content of WT and PNM2 cells revealed interference of light penetration by PHB. WT cells synthesized PHB at an early stage of the cultivation. PHB degradation after exhaustion of acetate during the cultivation of WT resulted in a decrease of the extinction coefficient. The hydrogen production rate under anaerobic conditions with fixed illumination was examined in WT and PNM2 cell suspensions at different densities. The hydrogen production rate was determined not by the light penetration but by the kinds of hydrogen donors and the density of suspension. The highest value of the rate of hydrogen production from PHB, 33.0 ml/l/h, was improved compared with 26.6 ml/l/h, which was the highest value in hydrogen production from succinate. Under the same illumination, conversion to hydrogen from PHB is more efficient than that from succinate, which is one of the best substrates for hydrogen production. These results suggest that the hydrogen production rate can be maximized in the hydrogen production system based on PHB degradation, which is achieved in high‐density suspension under external‐substrate‐depleted conditions after aerobic cultivation in the presence of an excess amount of acetate. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 81: 474–481, 2003.
Methyl‐β‐cyclodextrin‐enhanced solubilization and aerobic biodegradation of polychlorinated biphenyls in two aged‐contaminated soils
Authors: Fava Fabio , Bertin Lorenzo , Fedi Stefano , Zannoni Davide 
Published: December 2002

AbstractThe bioremediation of aged polychlorinated biphenyl (PCB)‐contaminated soils is adversely affected by the low bioavailability of the pollutants. Randomly methylated‐β‐cyclodextrins (RAMEB) were tested as a potential PCB‐bioavailability‐enhancing agent in the aerobic treatment of two aged‐contaminated soils. The soils, contaminated by about 890 and 8500 mg/kg of Aroclor 1260 PCBs, were amended with biphenyl (4 g/kg), inorganic nutrients (to adjust their C:N ratio to 20:1), and variable amounts of RAMEB (0%, 0.5%, or 1.0% [w/w]) and treated in both aerobic 3‐L solid‐phase reactors and 1.5‐L packed‐bed loop reactors for 6 months. Notably, significant enhancement of the PCB biodegradation and dechlorination, along with a detectable depletion of the initial soil ecotoxicity, were generally observed in the RAMEB‐treated reactors of both soils. RAMEB effects were different in the two soils, depending upon the treatment conditions employed, and generally increased proportionally with the concentration at which RAMEB was applied. RAMEB, which was slowly metabolized by the soil's aerobic microorganisms, was found to markedly enhance the occurrence of the indigenous aerobic, cultivable biphenyl‐growing bacteria harboring genes homologous to those of two highly specialized PCB degraders (i.e., bphABC genes of Pseudomonas pseudoalcaligenes KF707 and bphA1A2A3A4BC1 genes of Rhodococcus globerulus P6) and chlorobenzoic acid‐degrading bacteria as well as the occurrence of PCBs in the water phase of the soil reactors. These findings indicate that RAMEB enhanced the aerobic bioremediation of the two soils by increasing the bioavailability of PCBs and the occurrence of specialized bacteria in the soil reactors. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 81: 381–390, 2003.
Doxorubicin‐paclitaxel
Authors: Biganzoli Laura , Cufer Tanja , Bruning Peter , Coleman Robert E. , Duchateau Luc , Rapoport Bernardo , Nooij Marianne , Delhaye François , Miles D. , Sulkes Aaron , Hamilton A. , Piccart Martine 
Published: December 2002

AbstractBACKGROUNDThe potential cardiotoxicy of the doxorubicin‐paclitaxel regimen, when paclitaxel is given shortly after the end of the anthracycline infusion, is an issue of concern, as suggested by small single institution Phase II studies.METHODSIn a large multicenter Phase III trial, 275 anthracycline naive metastatic breast carcinoma patients were randomized to receive either doxorubicin (60 mg/m2) followed 30 minutes later by paclitaxel (175 mg/m2 3‐hour infusion; AT) or a standard doxorubicin‐cyclophosphamide regimen (AC; 60/600 mg/m2). Both treatments were given once every 3 weeks for a maximum of six cycles. Close cardiac monitoring was implemented in the study design.RESULTSCongestive heart failure (CHF) occurred in three patients in the AT arm and in one patient in the AC arm (P = 0.62). Decreases in left ventricular ejection fraction to below the limit of normal were documented in 33% AT and 19% AC patients and were not predictive of CHF development.CONCLUSIONSAT is devoid of excessive cardiac risk among metastatic breast carcinoma patients, when the maximum planned cumulative dose of doxorubicin does not exceed 360 mg/m2. Cancer 2003;97:40–5. © 2003 American Cancer Society.DOI 10.1002/cncr.10914
Long‐term follow‐up of a prospective policy of margin‐directed radiation dose escalation in breast‐conserving therapy
Authors: Neuschatz Andrew C. , DiPetrillo Thomas , Safaii Homa , Price Lori Lyn , Schmidt‐Ullrich Rupert K. , Wazer David E. 
Published: December 2002

AbstractBACKGROUNDA prospectively applied treatment policy for breast‐conserving therapy used margin assessment as the exclusive guide to the intensity of radiation therapy directed at the tumor bed.METHODSFrom 1982 to 1994, 498 women with 509 Stage I/II breast carcinomas with a median follow‐up of 121 months were treated. Final margin status (FMS) categories were defined as greater than 5 mm, greater than 2–5 mm, greater than 0–2 mm, and positive. For margins less than or equal to 2 mm or indeterminate, reexcisions were performed if feasible. All patients received whole breast irradiation to 50.0–50.4 Gy. Final tumor bed boosts as a function of FMS were as follows: no residual on reexcision, no boost performed; FMS greater than 5 mm, boost of 10 Gy; FMS greater than 2–5 mm, boost of 14 Gy; FMS greater than 0–2 mm or positive, boost of 20 Gy. Cases were analyzed for local failure with respect to histology, age, tumor size, excision volume, reexcision, and total dose.RESULTSFMS was positive, greater than 0–2 mm, greater than 2–5 mm, and greater than 5 mm, and no residual tumor on reexcision in 21%, 20%, 17%, 14%, and 28% of cases, respectively. At 12 years, Kaplan–Meier local failure rates were 17% for FMS positive, 9% for FMS greater than 0–2 mm, 5% for FMS greater than 2–5 mm, 0% for FMS greater than 5 mm, and 6% for specimens without evidence of residuum on reexcision (P = 0.009). Patients 45 years old and younger had a 12‐year local failure rate of 15% whereas patients older than 45 years had a 12‐year local failure rate of 6% (P = 0.01). On multivariate analysis, young age (P = 0.03) predicted increased local failure rate, whereas margins that were less than or equal to 2 mm or positive predicted late (> 5 years) but not early (≤ 5 years) recurrence (P = 0.003).CONCLUSIONSGraded tumor bed dose escalation in response to FMS results in very low rates of local failure over the first 5 years for all FMS categories. However, tumors with close/positive margins have significantly increased local failure rates after 5 years of follow‐up even with increased radiation boost dose. In addition, graded tumor bed dose escalation does not fully overcome the adverse influence of young age. Cancer 2003;97:30–9. © 2003 American Cancer Society.DOI 10.1002/cncr.10981