bluuebunny/crossref_metadata_2025 huggingface dataset:
Persistent asthma: disease control, resource utilisation and direct costs
Authors: Van Ganse E. , Laforest L. , Pietri G. , Boissel J.P. , Gormand F. , Ben-Joseph R. , Ernst P.
Published: October 2002

Despite evidence that adverse outcomes are less frequent when asthma management is optimised, the link between the level of control, disease severity and medical resource utilisation (MRU) is poorly documented. This relationship was investigated in a group of patients suffering from persistent asthma (Global Initiative for Asthma (GINA) ≥2) in France.

In 1998 a computerised family practice database was used to identify asthma patients aged 17–50 yrs. Information from the database was complemented by a patient survey to retrospectively assess the level of asthma control and hospital contacts. Costs of MRU over a 12­month study period were related to demographics, medical history, asthma control, and doses of inhaled corticosteroids prescribed during the prestudy period.

A review of the computerised medical database identified 1,038 adult patients with persistent asthma, who completed the survey questionnaire. Over a 12­month period, the mean cost of MRU was 549.8 E for well­controlled patients, 746.3 E per patient with moderate control, and 1,451.3 E per patient with poor control. Costs also increased significantly with age, access to free asthma care, comorbid conditions, asthma symptoms in the past year and whether inhaled corticosteroids had been prescribed before the study period.

In patients with persistent asthma, large differences were observed in the use of medical resources according to control and severity. Therefore, if patients appropriately use prescribed control therapy, their use of medical resources may be reduced.
Increased expression of activation markers and adhesion molecules on lung T-cells compared with blood in the normal rat
Authors: Tschernig T , Fliegert F , Westermann J , Pabst R
Published: October 2002

Lymphocytes play an important role in many lung diseases and are routinely accessible by bronchoalveolar lavage (BAL). Lymphocytes from the BAL (BAL pool) have a different subset composition to those from peripheral blood, consisting mainly of activated T-cells. The aim of this study was to examine whether preferential migration of activated T-cells to the bronchoalveolar space or factors of the specific microenvironment mediate this phenomenon. The expression of adhesion molecules and cellular activation markers (intercellular adhesion molecule-1, leukocyte function-associated antigen-1, CD2, CD44, interleukin-2 receptor and L-selectin) was studied on T- and B-cells not only in the BAL and peripheral blood (blood pool), but also in the compartments in between, such as the lung vascular perfusate (marginal pool) and the lung interstitium (interstitial pool), with the experiments being performed simultaneously in the same animals. Low levels of adhesion molecule expression were observed on T-cells in the blood and marginal pool, medium levels in the lung interstitium and the highest levels in the BAL. "Memory" (CD45R(low)) and "naive" (CD45R(high)) T-cells in the lung compartments showed a higher expression of adhesion molecules compared with blood. However, the predominating CD45R(low) T-cells showed a significantly higher expression than the CD45R(high) cells, indicating that CD4+ CD45R(high) T-cells had changed their phenotype to CD45R(low). In conclusion, a high level of expression of leukocyte function associated antigen-1 and intracellular adhesion molecule-1 on the bronchoalveolar lavage and interstitial T-cells is more likely to be the result of local, lung-specific induction than a prerequisite for migration into the bronchoalveolar space.
The bronchoprotective effect of inhaled salmeterol in preschool children: a dose-ranging study
Authors: Primhak RA , Smith CM , Yong SC , Wach R , Kurian M , Brown R , Efthimiou J
Published: October 2002

The optimal dose of salmeterol in infants and preschool children is not known. The aim of this study was to assess the bronchoprotective effect of different doses of salmeterol using methacholine-induced wheeze in children aged <4 yrs. Children <4 yrs old with a history of recurrent wheeze underwent two methacholine challenges within 7 days. One hour before each challenge they were pretreated in double-blind fashion using a metered-dose inhaler and Babyhaler spacer. Placebo was given before one challenge, and either 25, 50 or 100 microg of salmeterol before the other. Both the dose and treatment order were random. The provocative concentration of methacholine causing wheeze (PCwheeze) was measured on each occasion. Studies were terminated when wheeze occurred or arterial oxygen saturation (Sa,o2) fell below 91%. Of the 42 children enrolled, 33 completed the study. Two subjects refused the challenge test, two failed to return and five developed upper respiratory tract infections or wheeze between the two tests. The mean (range) age of the population was 27 (8-46) months. Ratios of PCwheeze between treatment and placebo challenges were calculated for each dosage group. The treatment/placebo ratios (95% confidence intervals) were 1.2 (0.6-2.4) for 25 microg, 2.5 (1.4-4.6) for 50 microg (p<0.01), and 4.0 (2.1-7.4) (p<0.001) for 100 microg doses. In recurrently wheezy children aged <4 yrs a single dose of salmeterol between 25 and 100 microg has a dose-dependent effect on methacholine-induced wheeze, and this is significantly different from placebo at 50 and 100 microg. This study suggests that the Babyhaler effectively delivers salmeterol to children <4 yrs of age and that doses between 50-100 microg are efficacious.
Structures of surfactant films: a scanning force microscopy study
Authors: Grunder R , Gehr P , Bachofen H , Schurch S , Siegenthaler H
Published: October 2002

The alveolar lining layer is thought to consist of a continuous duplex layer, i.e., an aqueous hypophase covered by a thin surfactant film which is a monolayer with dipalmitoyl-phosphatidylcholine (DPPC) as its most important component. Findings obtained by electron microscopy and results from in vitro experiments suggest, however, that the structure and hence the structure-function relations of surfactant films are more complex. In order to better define their structures films of surfactants were studied by scanning force microscopy. Four different surfactants were spread on a Langmuir-Wilhelmy balance, and then transferred onto a solid mica plate by the Langmuir-Blodgett technique, under various states of film compression. Imaging of the films by scanning force microscopy was performed in the contact (repulsive) mode in air. The scanning force micrographs revealed that surfactant films are not homogeneous, but rather undergo phase transitions depending on the surface pressures. Even at comparable surface pressures different surfactants show quite different surface patterns. Differences in surface structure can even be observed in films containing surfactant proteins (SP)-B and SP-C. These observations give further evidence that the widely accepted hypothesis of a regular monolayer of phospholipids governing the surface tension probably does not hold true, but that the structure-function relationship of surface active surfactant films is even more complex than hitherto thought.
The effects of gadolinium, a stretch-sensitive channel blocker, on diaphragm muscle
Authors: Coirault C , Sauviat MP , Chemla D , Pourny JC , Lecarpentier Y
Published: October 2002

Stretch-activated channels (SAC) have been identified in many cell types including striated muscles. In diaphragm muscle, the influence of SAC on the length-active tension relationship remains unknown. Patch clamp experiments were performed on single fibres (n = 10). In isolated diaphragm muscle from adult hamsters, the effects of gadolinium (Gd3+), the most potent inhibitor of SAC blocker, on tension response to stretch at baseline were studied (n = 10), after pretreatment of the muscle with 1 nmol isoproterenol (n = 10), 0.5 micromol forskolin (n = 6), or 0.1 mmol dibutyryl cyclic adenosine monophosphate (cAMP) (n = 10). Results were compared to those obtained in low [Na+]e (n = 10), Ca2+-free medium (n = 6) or after 5 micromol nifedipine (n = 8). Gd3+ reduced active tension measured over a range of initial muscle lengths in a concentration-dependent manner (10 and 50 micromol). In isolated fibres, mechanical stretch generated a membrane current that was sensitive to Gd3+. In muscles, lowering [Na+]e mimicked the effects of Gd3+, while no change in the length-tension relationship was observed in Ca2+-free medium or after nifedipine. Drugs which increase cAMP prevented the effects of Gd3+ on active tension. In the diaphragm, gadolinium-sensitive channels are activated during physiological changes in length and influence tension development. Moreover, cyclic adenosine monophosphate content modulates the effects of gadolinium on stretch-activated channels.
Environmental factors and asthma and allergy in schoolchildren from Western Australia
Authors: Palmer LJ , Valinsky IJ , Pikora T , Zubrick SR , Landau LI
Published: October 2002

The association of environmental factors with atopic disease in children remains poorly understood. The aim of this study was to investigate the relationship between socio-environmental factors and symptoms of asthma and atopy in 6-7-yr-old children assessed as an adjunct to Phase I of the International Study of Asthma and Allergy in Childhood in Perth, Western Australia. Parental questionnaire responses were obtained for 2,193 children (73.6%) in 34 randomly selected primary schools in the Perth metropolitan area. Children born in Australia had a significantly increased risk of current asthma (odds ratio (OR) 237, p = 0.001). Having a mother born in Australia was the only factor independently associated with an increased risk of current hay fever (OR 1.56, p = 0.005). Increasing numbers of people living in the home were significantly associated with a multiplicative decrease in risk of current asthma (OR 0.88, p = 0.03) and eczema (OR 0.82, p = 0.01). Houses made of fibrocement (OR 2.40, p = 0.02) and the presence of mats on less than half of the floor area in the "main bedroom" (relative to wall-to-wall carpet) (OR 3.50, p = 0.003) were associated with an increased risk of current eczema. All reported associations were independent of socioeconomic status (categorized by school), age and sex. This study suggests that household and country-specific environmental factors are associated with asthma, hay fever and eczema risk in 6-7-yr-old schoolchildren, and may have substantially contributed to the increased prevalence of these diseases in Australia.
Nasal hyperresponsiveness to histamine induced by repetitive exposure to cedar pollen in guinea-pigs
Authors: Mizutani N , Nabe T , Sasaki K , Takenaka H , Kohno S
Published: October 2002

Nasal hyperresponsiveness is one of the characteristic features of the pathogenesis of allergic rhinitis. This study examined whether repetitive inhalation of antigen (Japanese cedar pollen) led to the development of nasal hyperresponsiveness to histamine in sensitized conscious guinea-pigs. Guinea-pigs were repeatedly challenged by pollen inhalation once every week following sensitization by means of intranasal application of pollen extract plus aluminium hydroxide. The upper airways obstruction (increase in specific airway resistance (sRaw)) in response to intranasally instilled histamine was measured as an index of nasal (hyper)responsiveness. The hyperresponsiveness to histamine gradually developed with repeated pollen inhalation challenge, and the airway response at the 20th and 24th challenges was three to four orders of magnitude higher than that in nonsensitized animals. Similar degrees of hyperresponsiveness were observed at 10 h and 2 days after a pollen inhalation challenge, but the hyperresponsiveness had almost disappeared by day 7. The increased responsiveness was suppressed by pretreatment with mepyramine but not with atropine. The maximum sRaw, which was observed 10 min after histamine instillation, was largely blocked by naphazoline. Hyperresponsiveness was hardly observed on methacholine instillation. The present allergic rhinitis model, showing marked nasal hyperresponsiveness to histamine after repeated intranasal allergen challenge in guinea pigs, should be useful for investigating the pathogenesis of allergic rhinitis.
Physiotherapy for airway clearance in adults
Authors: Pryor JA
Published: October 2002

Techniques for augmenting, when necessary, the normal mucociliary and cough clearance mechanisms of the lungs are not new, but, in more recent years, techniques have been developed which are effective, comfortable and can be used independent of an assistant in the majority of adolescents and adults. Postural drainage with chest clapping and chest shaking has, in most parts of the world, been replaced by the more effective techniques of the active cycle of breathing, autogenic drainage, R-C Cornet, Flutter, positive expiratory pressure mask, high-frequency chest wall oscillation and intrapulmonary percussive ventilation. Glossopharyngeal breathing is being considered again and is often a useful technique for increasing the effectiveness of cough in patients with tetraplegia or neuromuscular disorders. The evidence in support of these techniques is variable, and the literature is confusing and conflicting. There may or may not be significant differences among the techniques in the short or long term. Many of the regimens now include the forced expiratory manoeuvre of a "huff" and this has probably increased the effectiveness of airway clearance. If objective differences are small, individual preferences and cultural influences may be significant in increasing adherence to treatment and in the selection of an appropriate regimen or regimens for an individual patient.
Assessment of Stroke Index Using Impedance Cardiography: Comparison with Traditional Vital Signs for Detection of Moderate Acute Blood Loss in Healthy Volunteers
Authors: Kosowsky Joshua M. , Han Jin H. , Collins Sean P. , McAfee Andrew T. , Storrow Alan B.
Published: October 2002

Objectives:Impedance cardiography has been used to detect early hemorrhagic shock, but, to the best of the authors' knowledge, no previous study has looked at the test characteristics of bioimpedance‐derived hemodynamic parameters for the detection of a measured loss of blood volume. The authors set out to investigate the effect of controlled hemorrhage on stroke index (SI) using impedance cardiography, and to evaluate the performance of this test for moderate blood loss in comparison with the performance of traditional vital signs.Methods:Supine and standing measurements of SI were made using a thoracic electrical bioimpedance monitor in 197 healthy, adult volunteers before and after donation of a standard unit (500 mL) of whole blood. Pre‐ and post‐donation means for supine SI, heart rate (HR), systolic blood pressure (SBP), and diastolic blood pressure (DBP), and for the postural changes in each of these measurements (▵SI, ▵HR, ▵SBP, ▵DBP), were compared using a paired‐sample, two‐tailed t‐test. For each term, receiver operating characteristic (ROC) curves were generated, treating pre‐ and post‐donation populations as independent. Areas under the ROC curves were compared using a method for correlated test result data.Results:Mean ± SD pre‐ and post‐donation values for SI were 47.0 ± 6.9 mL/m2and 43.9 ± 7.3 mL/m2, respectively (p < 0.0001). Mean pre‐ and post‐donation values for ▵SI were ‐7.7 ± 5.8 mL/m2and ‐9.0 ± 8.2 mL/m2, respectively (p = 0.02). For discriminating between pre‐ and post‐donation status, the areas under the ROC curves for SI and ▵SI were 0.62 and 0.58, respectively. In comparison, the areas under the ROC curves for HR, SBP, DBP, ▵HR, ▵SBP, and ▵DBP were 0.49, 0.61, 0.56, 0.82, 0.53, and 0.50, respectively. The area under the ROC curve for ▵HR was significantly greater than the area under any of the other curves (p < 0.0001).Conclusions:Moderate blood loss was associated with a decline in mean SI that was clearly detectable with impedance cardiography. However, as a test for moderate blood loss in this controlled setting, neither SI nor ▵SI performed better than traditional vital signs.
Perspectives on Practicing Procedures on the Newly Dead
Authors: Oman Kathleen S. , Armstrong John David , Stoner Martha
Published: October 2002

Invasive procedures are commonly practiced and taught on newly deceased patients (the newly dead) in emergency and critical care settings. Justified by the claim of necessity for professional competence to provide lifesaving care, these procedures, commonly hidden from public and professional scrutiny, are frequently performed on the newly dead without consent from family or interested parties. Objective: To describe older adults' beliefs about practicing and teaching lifesaving procedures on the newly dead and their belief about the requirement for consent for these procedures. Methods: An exploratory, descriptive design used a seven‐item Likert‐type instrument with open‐ended questions to gather data from a convenience sample of 100 adults in two metropolitan cities. Results: The typical respondent was 74.5 years old (mean; range of 55‐95 years), female (71%), and married (44.8%) or widowed (36.5%). Most respondents were high school graduates (94%), and 63% had some level of college education. The majority of the sample was white (75%), they were predominately Protestant (40%), and 72% reported their health as good to excellent. Most study participants believed that practicing or teaching lifesaving skills on a newly dead body is acceptable (54%), and that provision for consent is necessary (80%). Planning to donate organs and preferring an autopsy were associated with agreeing that using the newly dead body for skill practice was acceptable; preferring cremation was related to believing that consent for skill practice on the newly dead was not necessary. Conclusions: The participants in this study value the use of the newly dead to practice and teach lifesaving skills, and believe that consent for this practice is necessary.
Are Intubation Conditions Using Rocuronium Equivalent to Those Using Succinylcholine?
Authors: Perry Jeffrey Joseph , Lee Jacques , Wells George
Published: October 2002

Objective: To determine whether the intubation conditions created by rocuronium are equivalent to those of succinylcholine during rapid‐sequence induction (RSI). Methods: Medline, EMBASE, and the Cochrane Controlled Trials Register were searched for randomized clinical trials (RCTs). The search strategy included all generic and trade names for succinylcholine and rocuronium, anesthesia, neuromuscular blockade, and a validated RCT filter. Intubation conditions were a required outcome. Two reviewers assessed studies for eligibility, data extraction, and quality. Intubation conditions were scored with Goldberg's scale (excellent conditions defined as clear vocal cords, easy tube insertion, and no cough). A‐priori subgroup analysis was conducted for the sedative, use of opioids, true versus modified RSI, age group, and the dose of rocuronium. Data were analyzed with Metaview 4.1 for relative risk (RR) of achieving excellent intubation conditions. A sample size calculation determined that n = 468 is required for equivalence. Results: Forty articles were identified; ten articles were excluded by the inclusion criteria, two were duplicate publications, and two had insufficient data. Therefore, 26 studies were analyzed. Overall, rocuronium was inferior to succinylcholine, with a RR = 0.87 (95% CI = 0.81 to 0.94) (N = 1,606). However, intubation conditions were similar in the propofol subgroup, with a RR = 0.96 (95% CI = 0.87 to 1.06) (N = 640). Failed intubations (N = 28) were equivalent in the two groups. Conclusions: Overall, succinylcholine creates excellent intubation conditions more reliably than rocuronium. If a second‐line agent is required, rocuronium used with propofol creates intubation conditions equivalent to those with succinylcholine.
Residency Training in Emergency Ultrasound: Fulfilling the Mandate
Authors: Heller Michael B. , Mandavia Diku , Tayal Vivek S. , Cardenas Evelyn E. , Lambert Michael J. , Mateer James , Melanson Scott W. , Peimann Nathan P. , Plummer David W. , Stahmer Sarah A.
Published: October 2002

Although bedside ultrasound is listed in the Model of the Clinical Practice of Emergency Medicine as an integral diagnostic procedure, the manner in which the didactic, hands‐on, and experiential components of emergency ultrasound are taught is not specifically prescribed by the Residency Review Committee for Emergency Medicine (RRC‐EM) or any single sponsoring group. Seven professional organizations [the American Board of Emergency Medicine (ABEM), the American College of Emergency Medicine (ACEP), the Council of Emergency Medicine Residency Directors (CORD), the Emergency Medicine Residents Association (EMRA), the National Association of EMS Physicians (NAEMSP), the RRC‐EM, and the Society for Academic Emergency Medicine (SAEM)] developed the Scope of Training Task Force, with the goal of identifying emerging areas of clinical importance to the specialty of emergency medicine, including emergency department (ED) ultrasound. The Task Force then identified a group of recognized authorities to thoughtfully address the issue of ED ultrasound training. This report represents a consensus of these identified experts on how emergency ultrasound training should be incorporated into emergency medicine residency programs.
Clinical Pharmacokinetics of Irinotecan and Its Metabolites: A Population Analysis
Authors: Xie Rujia , Mathijssen Ron H.J. , Sparreboom Alex , Verweij Jaap , Karlsson Mats O.
Published: October 2002

PURPOSE: To build population pharmacokinetic (PK) models for irinotecan (CPT-11) and its currently identified metabolites.

PATIENTS AND METHODS: Seventy cancer patients (24 women and 46 men) received 90-minute intravenous infusions of CPT-11 in the dose range of 175 to 300 mg/m2. The PK models were developed to describe plasma concentration profiles of the lactone and carboxylate forms of CPT-11 and 7-ethyl-10-hydroxycamptothecin (SN-38) and the total forms of SN-38 glucuronide (SN-38G), 7-ethyl-10-[4-N-(5-aminopentanoic acid)-1-piperidino]-carbonyloxycamptothecin (APC), and 7-ethyl-10-[4-amino-1-piperidino]-carbonyloxycamptothecin (NPC) by using NONMEM.

RESULTS: The interconversion between the lactone and carboxylate forms of CPT-11 was relatively rapid, with an equilibration half-life of 14 minutes in the central compartment and hydrolysis occurring at a rate five times faster than lactonization. The same interconversion also occurred in peripheral compartments. CPT-11 lactone had extensive tissue distribution (steady-state volume of distribution [Vss], 445 L) compared with the carboxylate form (Vss, 78 L, excluding peripherally formed CPT-11 carboxylate). Clearance (CL) was higher for the lactone form (74.3 L/h) compared with the carboxylate form (12.3 L/h). During metabolite data modeling, goodness of fit indicated a preference of SN-38 and NPC to be formed out of the lactone form of CPT-11, whereas APC could be modeled best by presuming formation from CPT-11 carboxylate. The interconversion between SN-38 lactone and carboxylate was slower than that of CPT-11, with the lactone form dominating at equilibrium. The CLs for SN-38 lactone and carboxylate were similar, but the lactone form had more extensive tissue distribution.

CONCLUSION: Plasma data of CPT-11 and metabolites could be adequately described by this compartmental model, which may be useful in predicting the time courses, including interindividual variability, of all characterized substances after intravenous administrations of CPT-11.
Complication Rates Among Cancer Patients With Peripherally Inserted Central Catheters
Authors: Walshe Louise J. , Malak Sharp F. , Eagan Janet , Sepkowitz Kent A.
Published: October 2002

PURPOSE: Peripherally inserted central catheters (PICCs) are frequently used to deliver outpatient courses of intravenous therapy. However, the rates and risks of complication for this device have not been well-studied. Our objective was to determine the incidence and risk factors of PICC-related complications with a 1-year prospective observational study.

PATIENTS AND METHODS: All PICCs inserted in adult and pediatric patients at Memorial Sloan-Kettering Cancer Center (MSKCC) were followed prospectively. The device insertion team, inpatient nurses, and various home-care companies and outside institutions collected longitudinal data.

RESULTS: Three hundred fifty-one PICCs were inserted during the study period and followed for a total of 10,562 catheter-days (median placement, 15 days; range, 1 to 487 days). Two hundred five PICCs (58%) were managed by home-care companies and outside institutions, and 146 PICCs (42%) were managed exclusively at MSKCC. For these 205 PICCs, 131 nurses from 74 home-care companies and institutions were contacted for follow-up clinical information. In all, 115 (32.8%) of 351 PICCs were removed as a result of a complication, for a rate of 10.9 per 1,000 catheter-days. Patients with hematologic malignancy or bone marrow transplant were more likely to develop a complication, whereas those with metastatic disease were less likely.

CONCLUSION: Complications occur frequently among cancer patients with PICCs, and long-term follow-up is onerous. Despite a high complication rate, the ease of insertion and removal argues for continued PICC use in the cancer population.
Vinyl- and Dienylpalladium Complexes Formed via Insertion of Alkyne into Sterically Hindered Pd–Aryl Bonds
Authors: Yagyu Takeyoshi , Osakada Kohtaro
Published: October 2002

[PdI(C6H3Me2-2,6)(bpy)] reacts with excess amounts of dimethyl acetylenedicarboxylate to produce [PdI{CZ=CZ-(C6H3Me2-2,6)}(bpy)] (2, Z = COOMe) and [PdI{CZ=CZ–CZ=CZ(C6H3Me2-2,6)}(bpy)] (3). Crystallographic study revealed the molecular structures of 2 and 3 the latter of which has an s-trans dienyl ligand.
Conformational Study of a Tetraacyl Biosynthetic Precursor of Lipid A by NMR
Authors: Oikawa Masato , Shintaku Tetsuya , Yoshizaki Hiroaki , Fukase Koichi , Adachi Seiji , Lee Keonil , Kusumoto Shoichi
Published: October 2002

During the course of a conformational study of lipid A, which is a bioactive entity of lipopolysaccharide of the Gram-negative bacterial cell surface, the molecular conformation of its tetraacyl biosynthetic precursor in dimethyl sulfoxide was unambiguously determined by means of NMR using both 6-13C-labeled and nonlabeled synthetic specimens. The conformation of the hydrophilic moiety was determined by an NMR analysis based on the spin-coupling constants and nuclear Overhauser enhancement data around the glycosidic linkage. The whole molecular shape of the glycolipid was then elaborated with the aid of molecular mechanics calculations.
Static and Dynamic Stereochemistry of N-Alkyl- and N,O-Dialkyl- N-9-triptycylhydroxylamine Derivatives
Authors: Yamamoto Gaku , Nakajo Fusako , Endo Naoka , Mazaki Yasuhiro
Published: October 2002

Stereochemistry of N-9-triptycylhydroxylamine and its N-alkyl and N,O-dialkyl derivatives was studied. X-ray crystallographic analysis of N,O-diethyl-N-9-triptycylhydroxylamine revealed (a) the chiral nature of the molecule, (b) an almost tetrahedral geometry of the nitrogen atom, and (c) a nearly eclipsing arrangement of the O–Et bond with the nitrogen lone-pair orbital. In solution, enantiomerization takes place rapidly at room temperature on the NMR time scale but slows down at low temperatures. The stereomutation proceeds by way of two processes, “R-passing,” and “O-passing,” in which the alkyl (R) and oxy (OH or OR) groups attached to the nitrogen atom, respectively, pass over a benzene ring, accompanied by nitrogen inversion and partial rotation of the N–O bond. The energy barriers to these processes were obtained by dynamic NMR spectroscopy.
InCl3-Catalyzed Reductive Coupling of Aromatic Carbonyl Compounds in the Presence of Magnesium and Chlorotrimethylsilane
Authors: Mori Kenji , Ohtaka Seiji , Uemura Sakae
Published: October 2002

Reductive homocoupling of aromatic aldehydes and ketones has been achieved in tetrahydrofuran at room temperature using a catalytic amount of InCl3 (0.005–0.1 molar amount) under nitrogen atmosphere in the presence of both chlorotrimethylsilane and magnesium metal (Mg turnings) to provide the corresponding 1,2-diols in good to moderate yields with a high diastereoselectivity.
Solid Surface Enhancement Effects on Chemiluminescence. III. Diaryloxalate as Chemiluminescence Reagent and Inorganic Materials as Media Solids
Authors: Yoshinaga Tetsutaro , Tanaka Yasuo , Ichimura Teijiro , Hiratsuka Hiroshi , Hasegawa Miki , Kobayashi Michio , Hoshi Toshihiko
Published: October 2002

Solid surface enhancement effects on chemiluminescence were studied using many inorganic materials as solid media. The results has been classified as follows: the first group (G-1) which has higher initial intensities and shorter lifetimes compared with the reference chemiluminescence (blank CL; medium solid used is a slide glass)—Al2O3 series including hydroxides and glass fiber filter fall under this group (G-1); the second group (G-2) which has lower initial intensities and longer lifetimes compared with the blank CL—high purity CaCO3 fall under this group (G-2); the third group (G-3) which has higher initial intensities and longer lifetimes compared with the blank CL—SiO2 powder and a silica fiber filter fall under this group (G-3); and the fourth group (G-4) which has lower initial intensities and shorter lifetimes compared with the blank CL—all remaining solid media other than group (G-1)–(G-3) fall under this group (G-4). Furthermore, from a chemiluminescent energy point of view, there exists another group (G-5) which has higher relative luminescent energies or relative quantum yields than the blank one–all the compounds that belong to the group (G-3) and others in group (G-1) and group (G-2), i.e., silica powder (SW-CO type), silica fiber filter (QR-100 type), and high purity calcium carbonate (3N-D type) are members of this group (G-5). Effects of surface condition and particle size on chemiluminescence were also examined.
Fundamental mechanisms of the growth and decay of the PNA teleconnection pattern
Authors: Feldstein Steven B.
Published: October 2002

This investigation performs diagnostic analyses on NCEP/NCAR re‐analysis data, and also does forced, nonlinear, barotropic model calculations to examine the dynamical mechanisms associated with the growth and decay of the Pacific/North American teleconnection pattern (PNA). The diagnostic calculations include projection and composite analyses of each term in the stream‐function‐tendency equation.

The results of the diagnostic analyses and model calculations reveal a PNA life cycle that is complete within approximately 2 weeks and is dominated by linear processes. The growth of the two upstream PNA anomaly centres is found to be by barotropic conversion from the zonally asymmetric climatological flow, and the two downstream PNA anomaly centres by linear dispersion. The PNA anomaly growth eventually ceases because of changes in the spatial structure of the anomaly. An analysis of the role of Ekman pumping is performed with a very simple model. The results, although qualitative, suggest that the decay of the PNA may be through Ekman pumping. An examination of the role of transient eddy vorticity fluxes indicates that they play an important role during some stages of the PNA life cycle. Lastly, the model calculations also reveal a crucial role played by the divergence term in maintaining the PNA anomaly in a quasi‐fixed position. Copyright © 2002 Royal Meteorological Society.
Equatorial waves in temperature in the altitude range 4 to 70 km
Authors: Murthy B. V. Krishna , Satheesan K. , Parameswaran K. , Sasi M. N. , Ramkumar Geetha , Bhavanikumar Y. , Raghunath K. , Krishniah M.
Published: October 2002

Using altitude profiles of temperature in the range 4 to 70 km derived from Mesosphere–Stratosphere–Troposphere radar and lidar observations at Gadanki (13.5°N,79.2°E) from 18 January 1999 to 5 March 1999, characteristics of equatorial waves are studied. Two‐dimensional Fourier‐transform analysis of the temperature profiles is carried out to identify the periodicities and their vertical wave numbers. From the characteristics obtained, equatorial slow Kelvin waves with periodicities 15.7 d, 9.4 d, 7.8 d and 6.7 d are identified in the troposphere and stratosphere regions and among these 7.8 d and 6.7 d periodicities are found to penetrate into the mesosphere. Equatorial waves with smaller periodicities in the range 5.2 d to 3.6 d are also observed. The vertical flux of horizontal momentum (zonal) of the identified slow Kelvin‐wave periodicities in the altitude region 4–25 km is estimated. It is found that equatorial waves modulate tropical tropopause temperature and altitude. Copyright © 2002 Royal Meteorological Society.
Fiscal Policy, Profits, and Investment
Authors: Alesina Alberto , Ardagna Silvia , Perotti Roberto , Schiantarelli Fabio
Published: October 2002

This paper evaluates the effects of fiscal policy on investment using a panel of OECD countries. We find a sizeable negative effect of public spending—and in particular of its wage component— on profits and on business investment. This result is consistent with different theoretical models in which government employment creates wage pressure for the private sector. Various types of taxes also have negative effects on profits, but, interestingly, the effects of government spending on investment are larger than those of taxes. Our results can explain the so-called “non-Keynesian” (i.e., expansionary) effects of fiscal adjustments.
The Impact of Economic Conditions on Participation in Disability Programs: Evidence from the Coal Boom and Bust
Authors: Black Dan , Daniel Kermit , Sanders Seth
Published: October 2002

We examine the impact of the coal boom of the 1970's and the coal bust of the 1980's on disability program participation. These shocks provide clear evidence that as the value of labor-market participation increases, disability program participation falls. For the Disability Insurance program, the elasticity of payments with respect to local earnings is between –0.3 and –0.4 and for Supplemental Security Income the elasticity is between –0.4 and –0.7. Consistent with a model where qualifying for disability programs is costly, the relationship between economic conditions and program participation is much stronger for permanent than for transitory economic shocks.
The Role of Economics in Climate Change Policy
Authors: McKibbin Warwick J , Wilcoxen Peter J
Published: October 2002

The most important characteristic of climate change as a policy problem is uncertainty. From climatology to economics, uncertainties are pervasive, large and difficult to resolve. However, the economic theory of environmental policy under uncertainty provides a clear guide to the design of an appropriate policy. An efficient and practical approach would be a hybrid that incorporates the best features of tradable permits and emissions taxes. Unfortunately, international negotiations have taken a different approach, focusing on rigid targets and timetables for emissions reductions. The result has been the Kyoto Protocol, an agreement with no real chance of reducing greenhouse gas emissions.
Sidetrack and Recompletion Risks in Oil Fields II. Economics of Sidetrack Development
Authors: Lerche I. , Noeth S.
Published: October 2002

The worth of undertaking a sidetrack well for an already producing oil field is examined in terms of the chances the sidetrack will fail and also the chances the sidetrack, even if successful, will kill already producing wells. The decision to proceed with such a sidetrack is shown to be sensitive to the residual producible reserves, the costs of the sidetrack, and its costs per bbl of oil relative to the costs through already producing wells and to the total cash flow achieved to date. In addition, the types of uncertainty ascribed to the future estimates made for production influence the decision, as do the ranges of uncertainty for unknown components, such as the chances of a successful sidetrack and the chances of killing producing wells. Simple numerical illustrations are provided to show how such uncertainties can be used to assess the inherent risk, and also to show how corporate mandates of minimum acceptable chance of success constrain the needed net value for the sidetrack situation. The general problem, with all parameters included, can be set up as a simple Excel spreadsheet calculation, so that recourse to massive computing power is not needed. In this way, and with the help of superposed Crystal Ball types of programs for assessing the influence of parameter value ranges and distribution types, one can quickly find out which parameters need to be better constrained to improve the assessment of whether a sidetrack is preferable to not undertaking such a development.
Hydrate Composition from Seismic Data: An Inverse Procedure
Authors: Lerche I. , Noeth S.
Published: October 2002

Hydrate existence conditions and the associated thermal gradients are examined using equations of state for mixes of gases. Three examples are developed to illustrate the resolution possible in determining the composition of a hydrate and the required range of thermal gradient using seismic information concerning the depth and thickness of a hydrate-bearing body. The examples use shallow (70m), medium (250m) and deep (600m) water as archetypical conditions. In general, it is shown that one cannot determine a unique composition for the hydrate due to incomplete knowledge of parameters in the hydrate existence equations of state, including the lack of knowledge concerning salinity and sedimentary lithological effects on parameters in the equations of state, and also due to such parameters being massively influenced by the types and mixing fractions of gases that compose the hydrate. What is shown is that it is possible to determine the cumulative probability that a hydrate has greater than a given fraction of methane and at the same time determine the probability that the associated thermal gradient lies within geologically required constraints. In association with this determination, one can also identify the relative contributions of each uncertain parameter to the resolution of the methane fraction and the thermal gradient, including geological parameters (such as sediment density) and “kinetic” parameters in the hydrate equation of state. In this way one can determine where to place effort in any further attempt to narrow down the uncertainty in the methane fraction for a given hydrate, and one can also identify when it is necessary to do so. These aspects are developed in the paper. There is also the point that, for deep water hydrates, the attempt to use the top of the hydrate body as the shallowest depth for hydrate existence can fail and recourse to a more appropriate strategy, but one that is not so statistically sharp, is required. This aspect, too, is developed in the paper. The main point to make is that the quantitative procedure developed here allows one to use seismic data directly to assess a hydrate body, to determine what can be deduced concerning hydrate composition, the sort of uncertainty one has to contend with, and also to determine the worth of proceeding further with more information collection to help resolve better the uncertainties.
A Modified Filtered-X LMS Algorithm for Active Control of Periodic Noise with On-Line Cancellation Path Modelling
Authors: Qiu Xiaojun , Hansen Colin H.
Published: October 2002

The filtered-x LMS algorithm (FXLMS) has been successfully applied to the active control of periodic and random noise and vibration. This paper presents a modified algorithm for active control of periodic noise based on the FXLMS algorithm which uses random noise for on-line cancellation path transfer function (CPTF) estimation. In the proposed algorithm, another two short adaptive filters are introduced. One is an adaptive noise cancellation filter, which is used to improve the convergence speed of the CPTF modelling filter in the presence of very large amplitude primary noise by cancelling the component of the error signal that is correlated with the primary noise. The other is an adaptive estimator, which is used to re-estimate the obtained CPTF (long FIR filter estimated by random noise) with a short FIR filter by using the periodic reference signal as the input. The traditional FXLMS algorithm is then used with the shortened FIR filter to filter the reference signal, thus providing significant processing flexibility in practical situations where the primary path transfer function changes much faster than the CPTF. Simulation results demonstrate the effectiveness of the proposed algorithm.
Digit Skin Temperature Test for Peripheral Circulation Evaluation
Authors: Pelmear P.L. , Ibanez D , de Veber G
Published: October 2002

A test procedure for evaluating vasospasm in hand digits using cold water immersion at 15°C for a period of 10 minutes is described, and the result of initial and repeat tests on 25 subjects who volunteered for a control group study are reported. Digit skin temperatures were continuously recorded and the recovery temperatures were noted while the hands were immersed and for a further 10 minutes afterwards in air. Five from their history and test results were determined to have Raynaud's disease or Constitutional White Finger, and a further 5 subjects with no history of cold hands or Raynaud's phenomenon had non-repeatable test results indicative of an asymptomatic sub-clinical state. A statistical analysis of the results from the 15 normal control subjects provides reference data (means and standard deviations) for the maximum skin temperature at 10 minutes immersion, and the skin recovery temperatures post-cold stress at 1 minute intervals in air. This objective test is frequently used for evaluating cold induced vasospasm in hand digits, and the normative data provided will enable abnormal subjects to be identified. Additional reference data is provided for use with vibration exposed workers to permit the severity of the vasospasm to be graded in accordance with the Stockholm vascular scale for Hand-arm Vibration Syndrome (HAVS).
Modelling and Open-Loop Control of a Single-Link Flexible Manipulator with Genetic Algorithms
Authors: Shaheed M. H. , Tokhi M. O. , Chipperfield A. J. , Azad A. K. M.
Published: October 2002

An open-loop control strategy for vibration suppression of a flexible manipulator system using genetic algorithms is presented in this paper. This consists of developing suitable forcing functions so that the dominant vibration modes of the system are not excited and hence the system vibration is reduced. The method requires that the vibration modes of the system be determined very precisely. Genetic algorithms (GAs) are used for this purpose. Low-pass and band-stop (elliptic type) filtered bang-bang torque inputs are accordingly developed on the basis of the identified vibration modes. The filtered torque inputs thus developed are applied to the system in an open-loop configuration and their performances in suppressing structural vibrations of the system are assessed in comparison to a bang-bang torque input. A comparative study of the low-pass and band-stop filtered torque inputs in suppressing the system vibrations are also presented and discussed.
The Hydrophobisation of Activated Carbon Surfaces by Organic Functional Groups
Authors: Budarin Vitaly L. , Clark James H. , Mikhalovsky Sergey V. , Gorlova Alina A. , Boldyreva Nataly A. , Yatsimirsky Vitaly K.
Published: October 2002

A technique of hydrophobic surface design with a high degree of structural homogeneity has been developed for catalytic materials. Mesoporous activated carbons and silica gel were modified by (A) treatment with vinyltrimethoxysilane (vtms) or (B) chlorination with carbon tetrachloride followed by reaction with a Grignard reagent. Evidence for silica gel modification was obtained from FT-IR and 13C NMR spectroscopy and from elemental analysis. Carbons chemically modified with alkanes and olefins were studied using thermogravimetry (TG) and the results compared with those for the modified silica gel. TG and differential scanning calorimetry (DSC) revealed that the polymerisation of vinyl groups occurred on the carbon surface. The participation of the carrier surface in the initiation of radical processes has been discussed.
Interaction of Hydride Silica Surfaces with N-Vinyl-2-Pyrrolidone
Authors: Belyakova L.A. , Varvarin A.M.
Published: October 2002

The solid-phase thermal and catalytic hydrosilylation of N-vinyl-2-pyrrolidone on the surface of hydride silicas has been studied. It was established that thermal polymerization of N-vinyl-2-pyrrolidone occurs as a side reaction during the thermal hydrosilylation of N-vinyl-2-pyrrolidone. It has also been found that the interaction of silicon hydride groups with water and propan-2-ol, as well as the formation of metallic platinum occur as side reactions during the catalytic hydrosilylation of N-vinyl-2-pyrrolidone on the surface of hydride silicas. Thermal hydrosilylation of N-vinyl-2-pyrrolidone in the absence of a catalyst and solvent is much preferred for the chemical bonding of N-vinyl-2-pyrrolidone in the surface layer of hydride silicas.
Adsorption and Adsorption Kinetics of the Vapours of Polar Substances on Microporous Carbon Adsorbents
Authors: Wojsz Roman
Published: October 2002

The applicability of the Polanyi–Dubinin (PD) potential theory to the adsorption of the vapours of polar and non-polar compounds on to microporous carbon adsorbents has been evaluated. Expressions describing the changes in the fundamental thermodynamic functions resulting from the modified PD theory have been presented. These dependencies are related to the adsorption isotherm equations with the inclusion of parameters for both the structural heterogeneity and the association of molecules.
The Role of Charcoal Ash Content in the Performance of Air Purification Filters
Authors: Bailey A. , Meech S.E. , Williams M.R.
Published: October 2002

A nutshell-based activated carbon was treated with hydrochloric acid to partially de-ash it. The de-ashed sample was then treated with bromine water and subsequently hydrogenated. The base sample was also treated with bromine water and then hydrogenated. The surface areas and pore volumes available to water vapour were unchanged by these treatments, although the polar surface area was considerably reduced in each case. The sample with the lowest surface polarity had the worst performance (shortest penetration time) when pre-humidified at 80% RH and tested with hexane. Examination of the humidity leaving the bed during the adsorption of hexane vapour suggested that the rate-determining step was the surface transport of displaced water and that removing the ash content hindered this transport considerably. Bromination followed by hydrogenation, although reducing the polarity, did not remove the ash content and may even have improved its ability to transport displaced water.
Studies of the Surface Properties of an MCM-41 Molecular Sieve Using Thermal Analysis and Nitrogen Adsorption Methods
Authors: Staszczuk P. , Danielkiewicz T. , Klinowski J.
Published: October 2002

The Q-TG mass loss and first derivative Q-DTG mass loss curves with respect to temperature and time obtained during programmed liquid thermodesorption under quasi-isothermal conditions have been used to study adsorbed layers on and the heterogeneous properties of an MCM-41 molecular sieve. The values of the adsorption capacity, total porosity of the material, discontinuous charges in adsorption layer properties and changes in the mechanism of the wetting process have been determined. The porosity parameters of the samples studied were also determined from nitrogen adsorption measurements. The total pore volumes of the tested samples were compared with thermogravimetric data with good correlations being obtained.