bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Relation Between the Quantity of Ammonium Compounds in Tobacco and the Nitrogen Monoxide (NO) Levels in the Smoke of Cigarettes Marketed in the Netherlands
Authors: van Amsterdam JGC , Brunt TM , Verlaan APJ , Cleven RFMJ , Opperhuizen A , Vleeming W 
Published: July 2016

Abstract
It has been suggested that ammonium compounds in tobacco generate nitrogen monoxide (NO) in cigarette smoke. This causes the smoke to retain the broncho-dilatory properties of the tobacco, which leads to an increased uptake of nicotine and thus to a potentially higher addiction to tobacco. The objective of this study was to ascertain putative correlations among the concentration of ammonium compounds in whole tobacco and the concentration of NO in mainstream smoke.
In 98 different cigarette brands marketed in the Netherlands, positive correlations were found between ‘tar’ and nicotine values (coefficient of variation, R2 = 0.95), and between ‘tar’ and NO concentration (R2 = 0.47). The quantity of ammonium compounds in tobacco (expressed as the amount of NH4+ present) varied, however, from 0.1 to 3.3 mg per gram of tobacco and was not associated with any of the parameters investigated here. In addition, five cigarette types were compared with respect to the levels of ammonium-compounds in the tobacco, the concentration of NO in the smoke and ‘tar’/nicotine ratio. The concentration of NO in the smoke from light menthol and light cigarettes (‘tar’ content < 9 mg/cig) was significantly lower than that from their regular equivalents (‘tar’ content > 9 mg/cig). As expected, the ‘tar’/nicotine ratio of regular cigarettes was significantly higher than the ratio in light cigarettes.
This study shows that the whole tobacco in the various cigarette brands differed in the amount of ammonium compounds it contained, but these amounts bore no relation to the level of NO and the level of nicotine and ‘tar’ in the smoke. Other factors that affect the burning process, such as nitrate content and product design may have made the association between ammonium compounds in tobacco and the level of NO in mainstream smoke less clear.
A Modelling Approach to Develop Machine Smoking Protocols Reflecting Human Puffing Behaviour for Conventional Cigarettes
Authors: Urban HJ , Gomm W , Schorop M 
Published: July 2016

Abstract
Our objective was to develop machine-smoking protocols (i.e. puff volume, puff duration and puff frequency) reflecting the distribution of human smoking behaviour as a complement to the International Standard (ISO) protocol. For this purpose, a modelling approach based on smoking topography and excretion data of urinary nicotine metabolites from clinical studies in the UK and Japan was used.
Three smoking protocols (LOW, MEDIUM and HIGH) were based on the 10th percentile, the mean and the 90th percentile of the puff volumes obtained from topography data. The corresponding puff durations were estimated by linear regression analysis of the puff duration/puff volume relationship. Finally, puff frequency was estimated using a predictive model assuming that the nicotine yield is a linear function (i.e. proportional) to the amount of air actually drawn through the burning part of the cigarette. This approach was termed ‘nicotine proportion method‘ where the puff frequency is changed iteratively until it equals the corresponding nicotine uptake measured in human smokers during a clinical study. The assumption was verified by measuring the nicotine yield in the laboratory on three modelled protocols for four conventional cigarettes. In 10 out of 12 cases, a very good agreement was observed between the estimated nicotine yields obtained with our modelling approach and the measured nicotine yields obtained from smoking machines in the laboratory.
Although smoking virtually identical cigarettes, smoking protocols based on topography and excretion data of urinary nicotine metabolites from the UK clinical study were different than those based on data from the study performed in Japan. This may be explained by different smoking behaviour between these two populations of smokers.
Isolation, Fractionation, and Identification of Sucrose Esters from Various Oriental Tobaccos Employing Supercritical Fluids
Authors: Ashraf-Khorassani M , Nazem N , Taylor LT , Coleman WM 
Published: July 2016

Abstract
Isolation, fractionation, and identification of sucrose esters from aged oriental tobacco employing supercritical fluids have been completed. Underivatized sucrose ester-rich extracts were obtained using supercritical CO2 at densities greater than 0.73 g/mL. Lower density CO2 provided extracts with notable amounts of tobacco derived material; yet, no detectable sucrose ester content. Preparative supercritical fluid chromatography (SFC) provided for an additional purification of the sucrose ester-enriched fraction after column optimization. Structural assignments of the SFC fractions were facilitated using gas chromatography/mass spectrometry (GC/MS) accompanied by N, O-bis(trimethylsilyl)trifluoroacetamide-dimethylformamide (BSTFA-DMF) derivatization of the free hydroxyl groups and high performance-liquid chromatography/mass spectrometry (HPLC/MS). From a relative quantitative perspective regardless of tobacco type, sucrose esters having an acetyl group on C6 of the glucose function (Group III) were in higher concentration compared to both the concentration observed for sucrose ester of Group I (acetyl group on C3 of fructose) and sucrose ester of Group II (no acetyl group on either glucose or fructose). Saturated fatty acid constituents were found to range from a maximum total of 18 carbons to a minimum total of 13 carbons. Unsaturated and isomeric fatty acid homologues were detected within the Group II sucrose ester.
Studies of the Formation of Smoke Phenols
Authors: Dyakonov AJ , Walker RT , Brown CA , Perini FR , Passer DS , Guan J , Robinson EA 
Published: July 2016

Abstract
Processes involving or forming phenols during combustion of tobacco were studied by differential scanning calorimetry (DSC), thermogravimetry (TG), mass-spectrometry (MS), X-band electron spin resonance (ESR), and thermocouple (TCT) and infrared thermography (IRT) methods. Thermochemical properties of polyhydroxybenzenes, polynuclear aromatic hydrocarbons (PAHs), and carbohydrates were investigated both individually and when the compounds were embedded in combustible or non-combustible matrices; the compounds were studied in an O2/He atmosphere at temperatures up to 800 °C, with a heating rate up to 60 °C/min. ESR of the mainstream smoke ‘tar’ was performed at temperatures down to -253 °C. The radicals found differed in their magnetic behavior depending on the material studied; this difference was attributed to the presence of relatively unstable isolated semiquinone and/or PAH-type molecules and the more stable quinone-hydroquinone-semiquinone redox complex.
Phenols themselves were found to affect combustion by radical scavenging and initiation. Added carbohydrates introduced diffusion limitations to oxygen. They also affected the combustion temperatures and could intensify the formation of phenols via quinone. Oxidation of PAHs was investigated and enthalpies were determined. These enthalpies decreased from benzo[a]pyrene (BaP) to anthracene, naphthalene and phenanthrene.
Investigation of Tobacco Pyrolysis Gases and Puff-by-puff Resolved Cigarette Smoke by Single Photon Ionisation (SPI) - Time-of-flight Mass Spectrometry (TOFMS)
Authors: Adam T , Mitschke S , Baker RR 
Published: July 2016

Abstract
The work presented deals with the application of Single Photon Ionisation- Time-of-Flight Mass Spectrometry (SPI-TOFMS) for the investigation of tobacco smoke. SPI-TOFMS is a modern analytical technique, which enables the simultaneous analysis of a large number of organic species in complex gas mixtures in real time. The paper is a summary of a PhD thesis (1) and seven research articles, which were recently published in various scientific journals (2-8). Consequently, more detailed information on particular aspects can be found in there.
The experimental part covers two different approaches, and therefore, it is divided into two sub-sections. In the first one, the SPI-TOFMS is coupled to a pyrolysis furnace. The objective is to examine the thermal behaviour of tobacco under various controlled conditions. In so doing, three tobacco types (Virginia, Oriental, and Burley) were pyrolysed in two reaction gas compositions (nitrogen and synthetic air) and seven different furnace temperatures (400 °C, 500 °C, 600 °C, 700 °C, 800 °C, 900 °C, and 1000 °C). Results can help to unravel the complex formation and decomposition reactions taking place when tobacco is heated. In the second part the SPI-TOFMS is connected to a cigarette smoking machine in order to investigate the behaviour of cigarette smoke constituents on a puff-by-puff basis. The work incorporates the comparison of whole smoke and gas phase of cigarette smoke, a puff-resolved quantification of several hazardous smoke constituents, and the overall chemical characterisation of the individual smoking puffs. In addition, a critical consideration of the prevailing smoking procedure is given when applied to single puff analysis. A further study examines the influence of five different cigarette lighting devices (gas lighter, electric lighter, candle, match, and burning zone of another cigarette) on the chemical composition of the first puff.
The Effect of Fertilization and Mycorrhiza on Cadmium Uptake by Tobacco
Authors: Janouskova M , Lugon-Moulin N , Martin F , Vosatka M 
Published: July 2016

Abstract
The effect of fertilization and arbuscularmycorrhiza (AM) on cadmium (Cd) uptake by tobacco (Nicotianatabacum L.) was studied in a greenhouse pot experiment. Two tobacco varieties and five AM fungal isolates were included in this study. Each combination of tobacco variety × AM fungal isolate was compared in two fertilization treatments: a nutrient solution and a slow-release fertilizer. Unexpectedly, root colonisation levels were low for most treatments. They were lower in the treatments having received the slow-release fertilizer than in the treatments with the nutrient solution. Inoculation with two AM fungal isolates led to a significant reduction of the Cd concentration in tobacco leaves. However, the main outcome of this study was the important effect of the fertilization regime on the Cd concentration of tobacco leaves. For one variety, Cd concentration was decreased by 48-58% in the slow-release fertilizer treatment when compared to the nutrient solution treatment. The effect of the fertilization regime on leaf Cd concentration was thus clearly more pronounced than that of AM. Similar results were obtained for the other variety, although the decrease was less pronounced.
Fibre and Particle Release from Cigarette Filters
Authors: Hengstberger M , Stark M 
Published: July 2016

Abstract
Particulates, especially those in the respirable fraction, are generally suspected of being responsible for a host of respiratory and cardiovascular health problems that may include an increase in morbidity and mortality. These effects have been related not only to the carbonaceous particulates, such as diesel soot, but also to more inert dust particles without any specific intrinsic hazard.
Therefore, any exposure to respirable dust from consumer products, and especially from tobacco products, is of considerable concern. In this context, a report of particular interest to the general public purported to show that cellulose acetate fibres released from cigarette filters could represent an additional burden and risk to the smoker. The underlying presumption was that these fibres could be respired and retained in portions of the respiratory tract, in particular in the lung.
In response to these assertions, studies were performed by and on behalf of the affected industry and the results showed that these fibres did not pose a health risk. The findings revealed that some acetate fibres were generated during the processing of the cigarettes, but they were captured on the cross-section of the cigarette filter and remained on the filter during smoking. Those fibres potentially released during smoking would be deposited inside the mouth area because they were too large to pass the larynx and could not physically enter the bronchial or pulmonary sections of the respiratory tract.
A working group from the German StandardisationOrganisation (DIN) recently discussed the experimental findings regarding the fibres generated during the processing of the acetate cigarette filter. Additional examinations on the release of respirable particles were initiated using Scanning Electron Microscope (SEM) to focus special attention on fibre-shaped particulates. The results of these recent analyses and the former findings led the group to the conclusion that ‘from the toxicological perspective, compared to the health risks otherwise associated with cigarette smoking, the release of particles from acetate filters does not constitute a particular health risk’.
Subsequent to this review and evaluation of the results some additional examinations were performed to examine further aspects of particle release. Using an improved analytical technique with real-time detection, the particle number and sizes were determined for the release of respirable particles from cigarettes and cigarette filters. The studies were performed by drawing air through filters and filter cigarettes in a clean room under intense smoking conditions, and the particles were analysed in real time with a Laser Aerosol Spectrometer. Using this technique, approximately 10 particles with a size greater than 0.3 ìm were counted per cigarette. This is comparable to a particle load in a clean room environment and representing approx. 0.05% of the particle load in ambient air.
The Composition of Cigarette Smoke. An Historical Perspective of Several Polycyclic Aromatic Hydrocarbons
Authors: Rodgman A , Cook LC 
Published: July 2016

Abstract
Because of the significant advancements in fractionation, analytical, and characterization technologies since the early 1960s, hundreds of components of complex mixtures have been accurately characterized without the necessity of actually isolating the individual component. This has been particularly true in the case of the complex mixtures tobacco and tobacco smoke. Herein, an historical account of a mid-1950 situation concerning polycyclic aromatic hydrocarbons (PAHs) in cigarette smoke is presented. While the number of PAHs identified in tobacco smoke has escalated from the initial PAH, azulene, identified in 1947 to almost 100 PAHs identified by late 1963 to more than 500 PAHs identified by the late 1970s, the number of PAHs isolated individually and characterized by several of the so-called classical chemical means (melting point, mixture melting point, derivative preparation and properties) in the mid-1950s and since is relatively few, 14 in all. They were among 44 PAHs identified in cigarette mainstream smoke and included the following PAHs ranging from bicyclic to pentacyclic: Acenaphthylene, 1,2-dihydroacenaphthylene, anthracene, benz[a]anthracene, benzo[a]pyrene, chrysene, dibenz[a, h]anthracene, fluoranthene, 9H-fluorene, naphthalene, 1-methylnaphthalene, 2-methylnaphthalene, phenanthrene, and pyrene. One of them, benzo[a]pyrene, was similarly characterized in another study in 1959 by Hoffmann.
On the abrasion of heat-treated 2.8C21Cr1Mo white cast iron
Authors: Al-Rubaie Kassim S. , Preti Orlando , Pohl Michael 
Published: July 2016

Abstract
The abrasion behaviour of heat-treated 2.8C21Cr1Mo cast iron was studied. The specimens were destabilised at two temperatures, 980 and 1050°C, for 4 h, air hardened, and then tempered at five temperatures, 220, 320, 400, 500, and 620°C, for 2 h followed by air cooling. Using a pin-on-plate abrasion apparatus, the specimens were abraded on four types of bonded abrasives (silicon carbide, corundum, flint, and glass). The effect of work hardening on the abrasion resistance was investigated. It was found that the increase in alloy hardness produced by heat treatment had little effect on the abrasion resistance against silicon carbide or corundum; the inverse was true against flint or glass. The as-hardened structure containing 40% retained austenite gave the best abrasion resistance, whereas the hardened and tempered at 620°C showed the worst. Both bulk hardness and matrix hardness before wear correlated poorly with the abrasion resistance. Therefore, a general model “equivalent hardness” was developed, in which the hardness of the abraded matrix was considered. With this model, the abrasion behaviour can be clearly analysed.
Novel method for dynamic control of intracranial pressure
Authors: Luciano Mark G. , Dombrowski Stephen M. , Qvarlander Sara , El-Khoury Serge , Yang Jun , Thyagaraj Suraj , Loth Francis 
Published: July 2016

OBJECTIntracranial pressure (ICP) pulsations are generally considered a passive result of the pulsatility of blood flow. Active experimental modification of ICP pulsations would allow investigation of potential active effects on blood and CSF flow and potentially create a new platform for the treatment of acute and chronic low blood flow states as well as a method of CSF substance clearance and delivery. This study presents a novel method and device for altering the ICP waveform via cardiac-gated volume changes.METHODSThe novel device used in this experiment (named Cadence) consists of a small air-filled inelastic balloon (approximately 1.0 ml) implanted into the intracranial space and connected to an external programmable pump, triggered by an R-wave detector. Balloons were implanted into the epidural space above 1 of the hemispheres of 19 canines for up to 10 hours. When activated, the balloons were programed to cyclically inflate with the cardiac cycle with variable delay, phase, and volume. The ICP response was measured in both hemispheres. Additionally, cerebral blood flow (heat diffusion and laser Doppler) was studied in 16 canines.RESULTSThis system, depending on the inflation pattern of the balloon, allowed a flattening of the ICP waveform, increase in the ICP waveform amplitude, or phase shift of the wave. This occurred with small mean ICP changes, typically around ± 2 mm Hg (15%). Bilateral ICP effects were observed with activation of the device: balloon inflation at each systole increased the systolic ICP pulse (up to 16 mm Hg, 1200%) and deflation at systole decreased or even inverted the systolic ICP pulse (−0.5 to −19 mm Hg, −5% to −1600%) in a dose-(balloon volume) dependent fashion. No aphysiological or deleterious effects on systemic pressure (≤ ±10 mm Hg; 13% change in mean pressure) or cardiac rate (≤ ± 17 beats per minute; 16% change) were observed during up to 4 hours of balloon activity.CONCLUSIONSThe results of these initial studies using an intracranially implanted, cardiac-gated, volume-oscillating balloon suggest the Cadence device can be used to modify ICP pulsations, without physiologically deleterious effects on mean ICP, systemic vascular effects, or brain injury. This device and technique may be used to study the role of ICP pulsatility in intracranial hemo- and hydrodynamic processes and introduces the creation of a potential platform of a cardiac-gated system for treatment of acute and chronic low blood flow states, and diseases requiring augmentation of CSF substance clearance or delivery.
Minimally invasive atlantoaxial fusion: cadaveric study and report of 5 clinical cases
Authors: Srikantha Umesh , Khanapure Kiran S. , Jagannatha Aniruddha T. , Joshi Krishna C. , Varma Ravi G. , Hegde Alangar S. 
Published: July 2016

OBJECTIVE
Minimally invasive techniques are being increasingly used to treat disorders of the cervical spine. They have a potential to reduce the postoperative neck discomfort subsequent to extensive muscle dissection associated with conventional atlantoaxial fusion procedures. The aim of this paper was to elaborate on the technique and results of minimally invasive atlantoaxial fusion.

MATERIALS
Minimally invasive atlantoaxial fusion was done initially in 4 fresh-frozen cadavers and subsequently in 5 clinical cases. Clinical cases included patients with reducible atlantoaxial instability and undisplaced or minimally displaced odontoid fractures. The surgical technique is illustrated in detail.

RESULTS
Among the cadaveric specimens, all C-1 lateral mass screws were in the correct position and 2 of the 8 C-2 screws had a vertebral canal breach. Among clinical cases, all C-1 lateral mass screws were in the correct position. Only one C-2 screw had a Grade 2 vertebral canal breach, which was clinically insignificant. None of the patients experienced neurological worsening or implant-related complications at follow-up. Evidence of rib graft fusion or C1–2 joint fusion was successfully demonstrated in 4 cases, and flexion-extension radiographs done at follow-up did not show mobility in any case.

CONCLUSIONS
Minimally invasive atlantoaxial fusion is a safe and effective alternative to the conventional approach in selected cases. Larger series with direct comparison to the conventional approach will be required to demonstrate clinical benefit presumed to be associated with a minimally invasive approach.
Au détour de la formation : le contrepoint de la recherche
Authors: Ferry Gilles 
Published: July 2016

L'initiation à la recherche comme élément constitutif d'une démarche de formation est présente dans les orientations des dernières années et les discours actuels sur la formation.
Après avoir développé la parenté possible entre l'acte de se former et celui d'être en recherche. Gilles Ferry situe le discours et la pratique de la recherche comme un contrepoint à instaurer dans la dynamique de la formation. Contestant l'approche qui consiste, de son point de vue à lier habituellement l'initiation à la recherche à un modèle pédagogique centré sur les acquisitions, l'auteur suggère et propose que l'activité de recherche soit liée à une pédagogie de la démarche dans une «dynamique du détour», ou/et à une pédagogie de l'analyse.
Approche qualitative multidimensionnelle de renseignant, perception et attentes des étudiants
Authors: Abernot Yvan , Turlot Jean-Christophe 
Published: July 2016

Grâce à un questionnaire portant sur les caractéristiques d'enseignants universitaires en situation d'une part, sur les idéaux d'autre part, les étudiants, mais aussi les enseignants eux-mêmes ont exprimé leurs perceptions et leurs attentes.
L'analyse factorielle des correspondances multiples montre que les étudiants distinguent principalement leurs enseignants sur des critères de prise en compte du public et d'académisme (compétence et «classissisme»). Leurs attentes portent sur une participation accrue à des cours plus variés. Les idéaux des étudiants et des enseignants sont identiques : compétence, grandes qualités pédagogiques et relationnelles. Si les enseignants interrogés se perçoivent assez proches de cet idéal, leurs étudiants ne sont pas toujours du même avis...
Le stéréotype de l'« enseignant idéal» est très puissant. Son étude doit entrer dans le cursus de formation des enseignants.