bluuebunny/crossref_metadata_2025_split huggingface dataset:
Raman microscopy of formamide‐intercalated kaolinites treated by controlled‐rate thermal analysis technology
Authors: Frost Ray L. , Kristóf János , Horváth Erzsébet , Theo Kloprogge J. 
Published: August 2002

AbstractRaman spectroscopy of formamide‐intercalated kaolinites treated using controlled‐rate thermal analysis technology (CRTA), allowing the separation of adsorbed formamide from intercalated formamide in formamide‐intercalated kaolinites, is reported. The Raman spectra of the CRTA‐treated formamide‐intercalated kaolinites are significantly different from those of the intercalated kaolinites, which display a combination of both intercalated and adsorbed formamide. An intense band is observed at 3629 cm−1, attributed to the inner surface hydroxyls hydrogen bonded to the formamide. Broad bands are observed at 3600 and 3639 cm−1, assigned to the inner surface hydroxyls, which are hydrogen bonded to the adsorbed water molecules. The hydroxyl‐stretching band of the inner hydroxyl is observed at 3621 cm−1 in the Raman spectra of the CRTA‐treated formamide‐intercalated kaolinites. The results of thermal analysis show that the amount of intercalated formamide between the kaolinite layers is independent of the presence of water. Significant differences are observed in the CO stretching region between the adsorbed and intercalated formamide. Copyright © 2001 John Wiley & Sons, Ltd.
Raman spectroscopy of hydrazine‐intercalated kaolinite at 77, 298, 323, 343 and 358 K
Authors: Martens Wayde N. , Ding Zhe , Frost Ray L. , Kristof János , Kloprogge J. Theo 
Published: August 2002

AbstractThe Raman spectrum at 298 K of hydrazine‐intercalated kaolinite shows a single band at 3620 cm−1. No other hydroxyl stretching bands are observed. Upon obtaining the spectrum at liquid nitrogen temperature the band is observed at 3616 cm−1, the same position as for the inner hydroxyl of the non‐intercalated kaolinite. Hence this band is assigned to the inner hydroxyl of kaolinite. After exposure to the atmosphere for 10 min and upon obtaining spectra at 77 K, two additional bands are observed at 3607 and 3625 cm−1. These additional bands are only observed after the onset of deintercalation. The band observed at 3625 cm−1 is assigned to the inner surface hydroxyls, hydrogen bonded to the hydrazine. The fact that the band is only observed after the onset of deintercalation suggests that the band is Raman inactive and infrared active. Raman spectroscopic analysis indicates that there are two types of hydrazine molecules as evidenced by two NH bands, (a) weakly hydrogen bonded as evidenced by two bands observed around 3300 and 3312 cm−1 and (b) a strongly hydrogen‐bonded hydrazine as evidenced by bands at 2890 and 2948 cm−1. The two NH symmetric stretching bands at around 3300 and 3312 cm−1 combined with the two NH antisymmetric stretching bands at 3361 and 3367 cm−1 suggest that there are two slightly different NH2 units in the hydrazine‐intercalated complex. Copyright © 2002 John Wiley & Sons, Ltd.
Vibrational characteristics of new double tungstates Li2MII(WO4)2 (M = Co, Ni and Cu)
Authors: Ma̧czka M. , Hanuza J. , Fuentes A. F. , Amador U. 
Published: August 2002

AbstractFor the first time, Raman and IR studies were performed on new double tungstates Li2MII(WO4)2 (M = Co, Ni and Cu) crystallizing in the wolframite‐type structure. The observed vibrational modes were assigned to the respective motions of atoms in the unit cell. The vibrational properties of the Cu derivative differ significantly from those of the cobalt and nickel derivatives. The differences were attributed to the differences in the crystal structures. A comparison of the results with literature data for MIIWO4 and LiMIII(WO4)2 (MII = Zn, Fe, Cu; MIII = Fe, In, Sc), crystallizing in the wolframite‐like structure, revealed a very large splitting for a few bridging modes and large shifts of the low‐wavenumber modes towards higher wavenumbers in the case of Li2MII(WO4)2. These features were assigned to different arrangements of tungsten–oxygen interactions within the infinite chains, which results in the formation of two non‐equivalent oxygen bridges in the structure of the compounds studied. Copyright © 2002 John Wiley & Sons, Ltd.
A framework for establishing and implementing corporate intelligence
Authors: Trim Peter 
Published: August 2002

Abstract
A commitment to corporate intelligence will assist senior management to formulate and implement strategies that counteract the actions of competitors and fraudsters.
In order that an Intelligence Unit is managed successfully it is vital for senior management to adopt a strategic approach to intelligence and security work.
An Advisory Board should be established to oversee the activities of the Director of Corporate Intelligence and provide advice and support during the early stage of the unit's development. Copyright © 2001 John Wiley & Sons, Ltd.
The effect of feeding pods of multipurpose trees (MPTs) on the degradability of dry matter and cell wall constituents of maize stover and alfalfa incubated in the rumen of sheep
Authors: Ngwa A T , Nsahlai I V , Bonsi M L K 
Published: August 2002

AbstractThis study evaluated the effects of feeding alfalfa and pods of tree legumes on rumen pH and ammonia concentration as well as in sacco degradability of dry matter and fibre constituents of maize stover, alfalfa hay and their neutral detergent extracts. The feeds were incubated in the rumens of five South African Merino sheep fed individually in an incomplete (5 × 4) Latin square design using five diets. The diets comprised equal proportions of pasture hay and either alfalfa (Alfalfa diet) or pods of Acacia sieberiana (Sieberiana diet), Acacia nilotica (Nilotica diet) or Leucaena leucocephala (Leucaena diet). The fifth diet was composed of pasture hay alone (Hay diet) and served as a negative control. Supplementation of hay with either legume pods or alfalfa significantly (p < 0.05) increased rumen ammonia concentration from 56 to a maximum of 86 mg l−1. The pH of the rumen fluid ranged between 6.2 and 6.5 for all diets, but variations in pH were not significant. Diet did not affect (p > 0.05) the degradability constants lag time (LT), slowly degradable fraction (B), potential degradability (PD), effective degradability (ED) and rate of degradation (C) of dry matter (DM) but significantly (p < 0.01) affected ED of the fibre constituents of the incubated feeds. The effective degradabilities of the incubated feeds differed (p < 0.001), with alfalfa and maize stover having average values of 555 and 318 g kg−1 DM respectively. The rate of degradation of alfalfa was also higher (p < 0.01) than that of maize stover. Neutral detergent extraction improved ED of the cell wall constituents of maize stover but produced the opposite effect for alfalfa. The interactions between incubation feed and extract were significant (p < 0.01) for ED and C of neutral detergent fibre and hemicellulose. The observations show that pods from tree legumes are comparable to alfalfa in the provision of rumen ammonia but limit microbial activity in the degradability of fibre constituents. They also show that maize stover and alfalfa differ in their degradabilities and that the differences may be attributed to their cell wall chemistry.© 2001 Society of Chemical Industry
Telomerase activity in esophageal squamous cell carcinoma: Down‐regulation by chemotherapeutic agent
Authors: Mitsui Akira , Kuwabara Yoshiyuki , Iwase Hirotaka , Mitani Masami , Shinoda Noriyuki , Sato Atsushi , Toyama Tatsuya , Sugiura Masahiko , Suzuki Tomotaka , Kato Joji , Fujii Yoshitaka 
Published: August 2002

AbstractBackground and ObjectivesTelomerase has been suggested as being necessary for continued cell growth and progression of cancer. Esophageal cancer and matched normal esophageal tissue from 54 patients were analyzed for telomerase activity, human telomerase reverse transcriptase (hTERT) mRNA expression, and their correlation with clinicopathological factors.MethodsTelomeric repeat amplification protocol was used for detection of telomerase activity and real time quantitative RT‐PCR was used for hTERT mRNA. An esophageal carcinoma cell line was used to study the effect of chemotherapeutic agent on telomerase.ResultsTelomerase activity was detectable in 79.6% of the tumor and 59.3% of the normal esophageal tissue. The level of telomerase activity in the tumor was significantly higher than that in the normal tissue. A significantly higher telomerase activity was observed in tumors with extensive blood vessel invasion. A significantly lower telomerase activity was observed in tumors that showed good response to preoperative chemotherapy than those with poor response. TE‐9 cells exposed to 5‐FU showed a diminished telomerase activity preceded by a time‐dependent decrease in the mRNA expression of hTERT.ConclusionsTelomerase activity was high in esophageal cancer tissue and showed positive correlation with blood vessel invasion. Chemotherapeutic agents may down‐regulate telomerase activity. J. Surg. Oncol. 2002;79:37–45. © 2002 Wiley‐Liss, Inc.
Does CH3 addition to C6H6 occur as reported?
Authors: Park J. , Lin M. C. 
Published: August 2002

AbstractThe kinetics for the CH3 + C6H6 reaction has been investigated by modeling the existing data obtained by Holt and Kerr [Int J Chem Kinet 1977, 9, 185.]. The result of the modeling suggests that the yields of CH4 measured in the UV photolysis of mixtures of (CH3CO)2, i‐C4H10, and C6H6 and employed in their analysis of the CH3 + C6H6 kinetics could be quantitatively predicted by the reactions of CH3 with i‐C4H10 and alkyl radicals present in the system, independent of the CH3 + C6H6 reaction. The CH3 + C6H6 reaction was concluded to be insignificant under the conditions employed on account of the instability of the C7H9 radical adduct and the strong CH bonds in benzene, which prevent the occurrence of the simple abstraction process. © 2001 John Wiley & Sons, Inc. Int J Chem Kinet 33: 803–807, 2001
Kinetics of the thermal isomerization of 1,1‐dimethylcyclopropane
Authors: Kalra Bansi L. , Lewis David K. 
Published: August 2002

AbstractRate constants for the unimolecular thermal isomerization of gaseous 1,1‐dimethylcyclopropane to isomeric methylbutenes have been measured, and Arrhenius parameters determined, over a wide temperature range, 683–1132 K, using a single‐pulse shock tube and a static reactor. For the overall reaction, Ea = 61.8 ± 0.4 kcal/mol, and log10(A, s−1) = 15.04 ± 0.10. These values are in good agreement with previously reported values obtained over a much narrower temperature range. Rate constants for formation of the two major products, 2‐methylbut‐2‐ene and 3‐methylbut‐1‐ene, are given by Ea = 61.9 kcal/mol, log A = 14.80 and Ea = 61.1 kcal/mol, log A = 14.54, respectively. A comparison of the activation parameters for structural isomerizations of cyclopropane, methylcyclopropane, and 1,1‐dimethylcyclopropane confirms a trend toward lower activation energy values as hydrogen atoms in cyclopropane are replaced by CH3 groups. © 2001 John Wiley & Sons, Inc. Int J Chem Kinet 33: 853–858, 2001
Kinetics and mechanism of the oxidation of 4‐methyl‐3‐thiosemicarbazide by acidic bromate
Authors: Jonnalagadda Sreekantha B. , Chinake Cordelia R. , Olojo Rotimi , Simoyi Reuben H. 
Published: August 2002

AbstractThe oxidation of 4‐methyl‐3‐thiosemicarbazide (MTSC) by bromate and bromine was studied in acidic medium. The stoichiometry of the reaction is extremely complex, and is dependent on the ratio of the initial concentrations of the oxidant to reductant. In excess MTSC and after prolonged standing, the stoichiometry was determined to be H3CN(H)CSN(H)NH2 + 3BrO3− → 2CO2 + NH4+ + SO42− + N2 + 3Br− + H+ (A). An interim stoichiometry is also obtained in which one of the CO2 molecules is replaced by HCOOH with an overall stoichiometry of 3H3CN(H)CSN(H)NH2 + 8BrO3− → CO2 + NH4+ + SO42− + HCOOH + N2 + 3Br− + 3H+ (B). Stoichiometry A and B are not very different, and so mixtures of the two were obtained. Compared to other oxidations of thiourea‐based compounds, this reaction is moderately fast and is first order in both bromate and substrate. It is autocatalytic in HOBr. The reaction is characterized by an autocatalytic sigmoidal decay in the consumption of MTSC, while in excess bromate conditions the reaction shows an induction period before autocatalytic formation of bromine. In both cases, oxybromine chemistry, which involves the initial formation of the reactive species HOBr and Br2, is dominant. The reactions of MTSC with both HOBr and Br2 are fast, and so the overall rate of oxidation is dependent upon the rates of formation of these reactive species from bromate. Our proposed mechanism involves the initial cleavage of the CN bond on the azo‐side of the molecule to release nitrogen and an activated sulfur species that quickly and rapidly rearranges to give a series of thiourea acids. These thiourea acids are then oxidized to the sulfonic acid before cleavage of the CS bond to give SO42−, CO2, and NH4+. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 237–247, 2002
Influence of nozzle‐to‐skin distance in cryogen spray cooling for dermatologic laser surgery
Authors: Aguilar Guillermo , Majaron Boris , Pope Karl , Svaasand Lars O. , Lavernia Enrique J. , Nelson J. Stuart 
Published: August 2002

AbstractBackground and ObjectiveCryogen sprays are used for cooling human skin during various laser treatments. Since characteristics of such sprays have not been completely understood, the optimal atomizing nozzle design and operating conditions for cooling human skin remain to be determined.Materials and MethodsTwo commercial cryogenic spray nozzles are characterized by imaging the sprays and the resulting areas on a substrate, as well as by measurements of the average spray droplet diameters, velocities, temperatures, and heat transfer coefficients at the cryogen‐substrate interface; all as a function of distance from the nozzle tip.ResultsSize of spray cones and sprayed areas vary with distance and nozzle. Average droplet diameter and velocity increase with distance in the vicinity of the nozzle, slowly decreasing after a certain maximum is reached. Spray temperature decreases with distance due to the extraction of latent heat of vaporization. At larger distances, temperature increases due to complete evaporation of spray droplets. These three variables combined determine the heat transfer coefficient, which may also initially increase with distance, but eventually decreases as nozzles are moved far from the target.ConclusionsSprayed areas and heat extraction efficiencies produced by current commercial nozzles may be significantly modified by varying the distance between the nozzle and the sprayed surface. Lasers Surg. Med. 28:113–120, 2001. © 2001 Wiley‐Liss, Inc.
A phantom with tissue‐like optical properties in the visible and near infrared for use in photomedicine
Authors: Lualdi Manuela , Colombo Ambrogio , Farina Bruno , Tomatis Stefano , Marchesini Renato 
Published: August 2002

AbstractBackground and ObjectiveModeling of light transport in tissue requires development of theoretical models and experimental procedures, as well as tissue‐simulating phantoms. Our purpose was to develop a phantom that matches the optical characteristics of human skin in the visible and near infrared spectral range.Study Design/Materials and MethodsThe phantom consists of a transparent silicone rubber in which Al2O3 particles and a cosmetic powder are embedded. Layers with thickness as thin as 0.1 mm can be made. The optical properties of Al2O3 particles and cosmetic powder, i.e., total attenuation, absorption and scattering coefficients, and phase function, have been determined in the visible and near infrared spectral range, by using direct and indirect techniques.ResultsBy varying the concentration of scattering and absorbing particles, tissue‐like layers can be produced with predictable optical properties. In particular, mixing at suitable concentration Al2O3 particles and cosmetic powder with the silicone rubber, the optical properties of human skin have been simulated over a range of wavelengths from 400 to 1,000 nm. The comparison between the phantom diffuse reflectance spectrum and that of human skin, averaged over a sample of 260 patients, showed a good agreement.ConclusionThe proposed technique allows to produce a stable and reproducible phantom, with accurately predictable optical properties, easy to make and to handle. This phantom is a useful tool for numerous applications involving light interaction with biologic tissue. Lasers Surg. Med. 28:237–243, 2001. © 2001 Wiley‐Liss, Inc.
Laser resurfacing with a long pulse erbium: YAG laser compared to the 950 ms pulsed CO2 laser
Authors: Rostan Elizabeth F. , Fitzpatrick Richard E. , Goldman Mitchel P. 
Published: August 2002

AbstractBackground and Objective:Laser resurfacing with the 950 μs pulsed CO2 laser is an effective treatment for photodamage and acne scarring; however, the potential for prolonged erythema and delayed re‐epithelialization dissuade many patients from the procedure. With the use of erbium lasers alone, there is a decrease in the incidence and severity of these adverse sequelae; however, it is difficult to achieve the same degree of improvement as with the CO2 laser because of the more superficial depth of resurfacing. Thus, new erbium lasers have been developed with longer pulse durations to deliver increased thermal effects to tissue. It is hypothesized that with the use of these lasers, diminished erythema and faster wound healing will be observed as well as enhanced clinical outcomes.Study Design/Materials and Methods:Sixteen patients were randomized to receive laser resurfacing on one‐half of the face with the 950 μs pulsed CO2 laser (UPCO2) followed by short pulse erbium:YAG ablation, and to the other half with a variable pulsed erbium laser (VP Er:YAG) followed by traditional short pulse erbium laser. Patients were evaluated clinically before resurfacing and at 1, 2, 4, 8, and 12 weeks post‐operatively. Histologic samples taken at various time periods before and after resurfacing were also evaluated.Results:Overall clinical improvement was equal for both UPCO2 and VP Er:YAG treated sides with an average improvement in photoaging scores of 57%. Decreased erythema, less edema, and faster healing were observed on the VP Er:YAG treated side.Conclusion:The VP Er:YAG laser can achieve a similar degree of improvement as seen with short pulse CO2 laser resurfacing with decreased thermal tissue effects and decreased risk for adverse sequelae. Lasers Surg. Med. 29:136–141, 2001. © 2001 Wiley‐Liss, Inc.
Vegetarianism: Toward a greater understanding
Authors: Janda Swinder , Trocchia Philip J. 
Published: August 2002

AbstractVegetarianism continues to gain prominence in contemporary society. This research uses a two‐phase approach to further the understanding of this phenomenon. In the first phase, a phenomenological perspective is utilized to provide a deeper understanding of the motivations, tensions, and coping mechanisms underlying vegetarianism. The second phase builds upon this understanding and broadens the scope of the research by introducing the concept of vegetarian orientation. Here, survey methodology is employed to investigate the manner in which a person's demographic, attitudinal, and personality characteristics influence his/her vegetarian‐oriented attitudes and behaviors. Findings and their marketing implications are discussed. © 2001 John Wiley & Sons, Inc.
Molecular orbital treatment of gas‐phase ion molecule collision rates: Reactive and nonreactive collisions
Authors: Dougherty Ralph C. 
Published: August 2002

Abstract

I.
Introduction
142

II.
Reaction Efficiency
144

III.
Ion Polar‐Molecule Collisions
145

IV.
Momentum‐Transfer Ion‐Molecule Collisions
146

V.
Summary
151

Acknowledgments
151

References
151

This paper reviews some applications of quantum mechanical models to ion‐molecule collision processes, and presents a new theoretical approach to ion mobilities of isobaric ions. Reactive ion‐molecule collisions have been successfully modeled, using perturbation molecular orbital (PMO) theory, and ab initio quantum mechanical models. In ion polar‐molecule collisions, the Stark effect exerts a controlling influence on the collision rate. The average dipole orientation for an ion polar‐molecule collision is exactly zero. The instantaneous dipole orientation to the ion‐molecule axis in these collisions is not zero. The instantaneous angle between the dipole and the ion‐molecule axis, Θ, increases as the distance between the ion and molecule, r, decreases. The Stark effect couples collisional angular momentum of the ion‐molecule complex and rotational angular momentum of the molecule. Conversion of collisional angular momentum to rotational angular momentum causes the rotation of the molecule to increase as the ion and molecule approach each other. Changes in Θ directly follow the changes in rotational angular momentum for the molecule. In momentum transfer ion‐molecule collisions in gases, the energy difference between the frontier orbitals of the collision pair is such that a first‐order perturbation model is not appropriate. An approximate second‐order PMO equation for the reduced mobility of ions in non‐polar gases, Ko PMO, is presented and used to analyze data from the literature. Ion mobility is linearly related to Ko PMO, a function of the ion‐molecule electronic potential, ΔEIM, and the reduced mass, μIM, for the ion bath‐gas interaction. The electronic states of first‐row transition metal ions separated by ion‐mobility in helium have been assigned on the basis of their reduced mobilities. © 2001 John Wiley & Sons, Inc., Mass Spec Rev 20:142–152, 2001
Expression of prostate‐specific antigen is transcriptionally regulated by genistein in prostate cancer cells
Authors: Davis Joanne N. , Kucuk Omer , Sarkar Fazlul H. 
Published: August 2002

AbstractProstate cancer is the second‐leading cause of cancer‐related deaths in men in the United States. Unfortunately, there is no effective therapy when prostate cancer becomes metastatic and refractory to conventional treatments. For this reason, the identification and exploration of new agents that reduce prostate cancer cell growth are of paramount importance. High consumption of plant‐derived phytoestrogens is inversely associated with the incidence and mortality rate of prostate cancer. Previous studies, including our own, have shown that the phytoestrogen genistein inhibits prostate cancer cell growth in vitro and in vivo and decreases secreted and intracellular levels of the androgen‐regulated protein prostate‐specific antigen (PSA), but the role of genistein as an agonist/antagonist for hormone receptors remains unclear. To elucidate the mechanism by which genistein modulates PSA protein expression in prostate cancer cells, we investigated the effects of genistein on androgen‐mediated and estrogen‐mediated transcriptional regulation of PSA, androgen receptor (AR) mRNA and protein expression, and the ability of nuclear proteins to bind to androgen‐response elements (AREs) in LNCaP cells. We showed that genistein decreased the transcriptional activation of PSA by both androgen‐dependent and androgen‐independent methods in LNCaP cells. The reduction of androgen‐mediated transcriptional activation of PSA was correlated with decreased AR protein and mRNA levels and decreased binding to AREs. In contrast, genistein had differential effects on 17β‐estradiol–mediated PSA expressions. Low concentrations of genistein enhanced 17β‐estradiol–mediated PSA expressions, whereas high concentrations of genistein inhibited estrogen‐mediated PSA expression in LNCaP cells. Genistein did not inhibit AR protein expression in the presence of 17β‐estradiol. These results suggest that ligand‐dependent differences in the ability to activate PSA expression may contribute to the agonistic/antagonistic responses observed with genistein in prostate cancer cells. © 2002 Wiley‐Liss, Inc.