bluuebunny/crossref_metadata_2025_split huggingface dataset:
Methods for Confirming the Gram Reaction of Gram-variable Bacillus Species Isolated from Tobacco
Authors: Morin A , Poirier N , Vallee S , Porter A 
Published: July 2016

Abstract

Bacillus is a predominant genus of bacteria isolated from tobacco. The Gram stain is the most commonly used and most important of all diagnostic staining techniques in microbiology. In order to help confirm the Gram positivity of Bacillus isolates from tobacco, three methods using the chemical differences of the cell wall and membrane of Gram-positive and Gram-negative bacteria were investigated: the KOH (potassium hydroxide), the LANA (L-alanine-4-nitroanilide), and the vancomycin susceptibility tests. When colonies of Gram-negative bacteria are treated with 3% KOH solution, a slimy suspension is produced, probably due to destruction of the cell wall and liberation of deoxyribonucleic acid (DNA). Gram-positive cell walls resist KOH treatment. The LANA test reveals the presence of a cell wall aminopeptidase that hydrolyzes the L-alanine-4-nitroanilide in Gram-negative bacteria. This enzyme is absent in Gram-positive bacteria. Vancomycin is a glycopeptide antibiotic inhibiting the cell wall peptido-glycan synthesis of Gram-positive microorganisms. Absence of lysis with KOH, absence of hydrolysis of LANA, and susceptibility to vancomycin were used with the Gram reaction to confirm the Gram positivity of various Bacillus species isolated from tobacco. B. laevolacticus excepted, all Bacillus species tested showed negative reactions to KOH and LANA tests, and all species were susceptible to vancomycin (5 and 30 µg).
Mini-Review: On the Transfer of Nicotine from Tobacco to the Smoker. A Brief Review of Ammonia and “pH” Factors
Authors: Dixon M , Lambing K , Seeman JI 
Published: July 2016

Abstract
A brief review is presented of the scientific literature on the effects of ammonia compounds, when used as tobacco additives, on the smoke chemistry and bioavailablity of nicotine. The review concludes that ammonia compounds used in the manufacture of certain types of tobacco sheet materials:
1) contribute to the flavor properties of cigarette smoke,
2) do not increase the amount, rate or efficiency of nicotine transferred from tobacco to mainstream smoke (MS),
3) do not increase the percentage of nicotine in MS gas phase using the FTC/ISO (Federal Trade Commission/International Organization for Standardization) method,
4) have no influence on the determination of MS nicotine yield as measured by the FTC/ISO method, and
5) do not increase the total rate or amount of nicotine absorbed by the smoker.
The review also examines the use of pH as it relates to tobacco and to smoke and suggests a terminology which more accurately describes the measurement (pH of aqueous extract of tobacco, pH of aqueous extract of smoke, and pH/electrode in smoke). Lastly, a number of research gaps in these areas are identified.
“Smoke pH”: A Review
Authors: Rodgman A 
Published: July 2016

Abstract
The analytical methods developed since the 1950s to determine the “smoke pH” of cigarette mainstream smoke (MSS) are reviewed. Most of the methods involve averaging the values obtained with all the puffs from a cigarette or averaging values from the total number of puffs from several cigarettes plus solution of the MSS in various quantities of water prior to pH determination. “Smoke pH” values thus obtained have little relevance to the situation involving a smoker who smokes a cigarette one puff at a time. In the human biological situation, the smoke components must traverse a layer of buffered fluid separating the smoke-filled respiratory tract cavity and the underlying tissue. Seldom is the effect of either the volume or the pH of the buffered fluid taken into account in determining the “smoke pH” of cigarette MSS taken one puff at a time. While numerous recent discussions have dealt with the effect of pH on the nature (degree of protonation) of nicotine in cigarette MSS and its rate of absorption by the smoker, seldom is the volume and/or pH of oral cavity saliva or of the fluid coating the lung surface considered in the assessment of either the nature or absorption of nicotine by the smoker. If the degree of protonation of nicotine be pH dependent, then the degree of protonation of nicotine as it traverses the film of fluid separating the respiratory tract cavity and the underlying tissue must be dependent on the pH of the buffered fluid and not on the “smoke pH” per se. Statements that adjustment of the “smoke pH” by ammoniation of one or more tobacco blend components increases both the level of MSS nicotine and its rate of absorption, thus resulting in greater consumer acceptance and continuation of smoking, fail to take into account the other changes that occur in the MSS composition to enhance its consumer acceptability. Inclusion of modest percentages of ammoniated tobacco in the blend increases the “smoke pH” of the MSS but does not necessarily increase MSS nicotine level. Not only are the MSS levels of several low molecular acids, aldehydes, and ketones known to be respiratory tract irritants substantially reduced but also the MSS levels of several highly flavorful pyrazines are substantially increased. These MSS composition changes yield an MSS classified as milder and more flavorful and whose consumer acceptability is considerably enhanced. Until the pH of MSS is determined on a per puff basis in a system simulating that in the oral cavity or the lung of the smoker, the nature of specific smoke components at the time of contact and their reactivity with respiratory tract tissue remain highly speculative. “Smoke pH” value for MSS, like the “tar” value for MSS, provides little, if any, useful information about the chemical composition of the source of the MSS or about its chemical and biological properties.
The Transfer of Nicotine from Nicotine Salts to Mainstream Smoke
Authors: Perfetti TA , Norman AB , Gordon BM , Coleman III WM , Morgan WT , Dull GM , Miller CW 
Published: July 2016

Abstract
Transfer of nicotine to mainstream smoke was measured for Reference cigarettes made with the addition of 20 -40 mg of seven different nicotine salts, d- and l-nicotine and N’-formylnornicotine. Regression analysis of the nicotine yields from these cigarettes as a function of the nicotine content of the tobacco rods indicated an average nicotine transfer efficiency (17.5%), similar to that found for a separate series of cigarettes made with single-grade tobacco materials (16.2%). Analysis of the enantiomeric purity of the smoke nicotine from the cigarettes made with added nicotine salts and neat nicotine showed no evidence of conversion between l- and d-nicotine during the smoking process. The cigarette made with added N’-formylnornicotine showed no evidence of additional nicotine transfer attributable to reduction of this compound to nicotine. A third series of cigarettes were made with varying levels of d- and l-nicotine added to a tobacco blend and to reconstituted tobacco to further investigate transfer efficiency of the enantiomers. Regression analysis indicated no statistically significant difference between transfer efficiencies of d- and l-nicotine. These results suggest that nicotine salts and d- and l-nicotine transfer to smoke at the same efficiency. However, transfer efficiency of either compound was lower when applied to reconstituted tobacco (9.7%) than when applied to the Reference tobacco blend (15.3%). The thermal stabilities of nicotine salts have little bearing on efficiency of transfer to smoke or on racemization between d- and l-nicotine. Formation of d-nicotine in mainstream smoke via reduction of N’-formylnornicotine does not appear to occur.
Aflatoxin B1 and Tobacco Products
Authors: Massey ED 
Published: July 2016

Abstract
The potential for aflatoxin B1 contamination of tobaccos and its subsequent transfer to smoke has been raised. This paper examines published work relevant to this issue and concludes that aflatoxin B1 is not a contamination issue on tobaccos and, even if present, would decompose in the burning cigarette and would not transfer to smoke.
Determination of Nicotine in Tobacco: Collaborative Study
Authors: Franke JE , Bennett CB , Davis RE , Thomsen HV , Johnston KS 
Published: July 2016

Abstract
An international collaborative study was performed to compare several analytical methods for the determination of nicotine in tobacco that are in current use around the world. Five nicotine methods were evaluated and compared, specifically methyl-t-butyl ether (MTBE) extraction with capillary-column gas chromatography (GC), n-hexane extraction with capillary-column GC, n-hexane extraction with packed-column GC, methanol/ammonia extraction with capillary-column GC, and aqueous extraction with continuous flow analyzer (CFA) colorimetry. A total of 37 laboratories participated in the study, with between 9 and 18 laboratories submitting data per nicotine method. Repeatability, reproducibility, and mean nicotine statistics were calculated and compared for each method. Results for reproducibility (%) and mean nicotine difference (%, relative to the mean of the three capillary-GC methods), respectively, for each method are as follows: MTBE method (2.5%, -1.40%), hexane-capillary (4.5%, +0.06%), methanol/ammonia (3.7%, +1.34%), CFA (4.4%, +4.08%), and hexane-packed (5.8%, +4.14%). Pair-wise group comparison tests with simultaneous 95% confidence intervals were used to compare the sample nicotine values between any two given methods. Eight of the ten pair-wise comparisons were statistically different at 95% confidence, the two statistically indistinguishable pair-wise comparisons being CFA vs. hexane-packed and hexane-capillary vs. methanol/ammonia. The results of this collaborative study will be useful toward the goal of standardizing on a reference method for nicotine analysis in tobacco and tobacco products.
Determination of Mercury in Mainstream Cigarette Smoke by Conventional and Amalgamation Cold Vapor Atomic Absorption Spectrometry
Authors: McDaniel RL , Torrence KM , Self DA , Chang MJ 
Published: July 2016

Abstract
A method for differentiation of gas- and particulate-phase mercury in mainstream cigarette smoke was developed using electrostatic precipitation (EP) as the trap for the particulate phase and impingers containing acidic potassium permanganate solution as the trap for the gas-phase portion. The mercury collected from the gas phase was analyzed by conventional cold vapor atomic absorption spectrometry (CVAAS) and the particulate phase was analyzed by gold amalgamation CVAAS. Cigarettes were smoked under two smoking regimes, FTC (35-mL puff volume, 2 s puff duration and one puff every 60 s) and an alternative (45-mL puff volume, 2 s puff duration, one puff every 30 s and 50% of any ventilation holes blocked) currently recommended by the Massachusetts Department of Health. For the 1R4F reference cigarette smoked under the FTC smoking regime, the mercury found in the particulate phase was less than 0.2 ng/cig, compared with 4.9 ng/cig in the gas phase. By changing smoking parameters, the mercury concentration in mainstream smoke was found to change proportional to the delivery of cigarette smoke condensate (CSC) for the same type of cigarette. However, the mercury level for different types of cigarettes smoked under the same smoking parameters had no linear relationship with CSC delivery. Spiked recovery was 98% AA± 8% for gas-phase mercury and 97% AA± 2% for the particulate phase. These results indicate that the analytical method developed is suitable for the determination of mercury in mainstream smoke. For routine analytical work in a smoking laboratory, only the gas phase needs to be analyzed for determination of mercury in mainstream smoke because the amount of mercury in the particulate phase is negligible.
Propagation of Cigarette Static Burn
Authors: Miura K , Kitao S , Egashira Y , Nishiyama N , Ueyama K 
Published: July 2016

Abstract
A propagation model of cigarette static burn at the cigarette periphery is proposed. Propagation of cigarette static burn is characterized by intermittent burn of the cigarette paper. The burning rate depends on the period of flash burn of the paper and is independent of the burning width. By measuring the local temperature near the front line of the burning propagation, the rate-determining step was identified as the time required to ignite the paper. A mathematical analysis was performed by calculating the heat transfer at the periphery during the paper heating period, and it was revealed that the thermal properties of the cigarette are the dominant factors of cigarette static burn. Modeling results showed good agreement with measured data.
Floral Morphology and Some Other Characteristics of Iso-genomic Alloplasmics of Nicotianatabacum L.
Authors: Berbec A 
Published: July 2016

Abstract
Cytoplasms of several Nicotiana species - N. amplexicaulis, N. bigelovii, N. debneyi, N. eastii, N. exigua, N. glauca, N. glutinosa, N. goodspeedii, N. knightiana, N. occidentalis, N. plumbaginifolia, N. raimondii, N. suaveolens, N. undulata - were bred into the N. tabacum genomic background of flue cured tobacco cv. Zamojska 4. The collection includes also a cytoplasmic male sterile (cms) analogue of cv. Zamojska 4 with mutated cytoplasm of N. tabacum. Some of the alloplasmics were originally obtained in this laboratory (N. amplexicaulis, N. eastii, N. exigua, N. glauca, N. knightiana, N. raimondii). The remaining ones were acquired from other laboratories and backcrossed into Zamojska 4. All alien cytoplasms except that of N. knightiana produced full male sterility in Zamojska 4. The extent of male organ modifications varied from complete absence of stamens (N. suaveolens, N. tabacum) to petaloid and stigmatoid structures (most common effect) to malformed stamens (N. amplexicaulis, N. glauca) to apparently normal stamens (N. raimondii, N. knightiana). The majority of the alloplasmics showed response to tentoxin that was compatible with the cytoplasm donor. The exceptions were those involving N. exigua, N. raimondii, (N. raimondii I), and the cytoplasmic mutant of N. tabacum. There was some variation in growth and morphology among the alloplasmic variants of Zamojska 4. Under field infestation alloplasmics with the cytoplasm of N. plumbaginifoliaand N. eastiishowed symptoms of blue mold whereas the remaining alloplasmics and cv. Zamojska 4 were highly tolerant of that disease.
Comparative Study of Leaf Surface Texture and Ability to Expand of Cured Tobacco
Authors: Rohr R , Eberhard A , Delon R , Descombes JP , Demor JM 
Published: July 2016

Abstract
Tobacco leaf texture, appreciated by the difference of surface roughness of cured leaves, is studies with light microscopy and scanning electron microscopy (SEM). The leaf texture is obviously determined by the presence or absence of conical cellular protuberances on the adaxial side of the leaf. Considering the anatomic point of view, the leaf thickness, always more important when the leaf texture is open, is the only objective criterion which could be associated to the texture. The ultra-structural study with SEM and transmission electron microscopy (TEM) demonstrates that the expansion capacity of tobacco doesn't rely on cytological factors such as cellular reserves or debris. The expansion capacity could be inversely proportional with the relative importance of the mesophyll comparing to palisade parenchyma. On the studied material, no direct relation between the leaf texture and the expansion capacity has been noticed.
Puff-by-puff Mainstream Smoke Analysis by Multiplex Gas Chromatography-Mass Spectrometry
Authors: Thomas CE , Koller KB 
Published: July 2016

Abstract
A puff-by-puff mainstream smoke procedure has been developed that provides the sensitivity and selectivity of a gas chromatography-mass spectrometry (GC-MS) system. The smoke analysis is based on automated sample collection and injection into the GC system. This development builds on, and complements, prior puff-by-puff procedures developed by Philip Morris USA, that utilized infrared (IR) analysis of gas-phase mainstream smoke. IR analysis of the gas-phase smoke for individual smoke constituents relies on the unique spectroscopic absorption patterns of each analyte. The new multiplex procedure relies on both chromatographic separation as well as spectroscopic separation. A significant feature of this method is that multiple injections are made prior to the complete elution of the first injected sample. The benefits of this methodology are that both sensitivity and the number of detected compounds are enhanced. While the multiplex method increases the complexity of the chromatographic data, the mass spectral analysis provides a means for data reduction to meaningful results. Many smoke constituents that are at concentrations below the Fourier transform infrared (FTIR) detection limit are observable with the multiplex analysis while maintaining the feature of puff-by-puff characterization of fresh smoke. The gas-phase mainstream smoke filtration performance of standard adsorption materials are discussed as a demonstration of the versatility and information content of this analytical procedure.
Studies of Polycyclic Aromatic Hydrocarbons in Cigarette Mainstream Smoke: Identification, Tobacco Precursors, Control of Levels: A Review
Authors: Rodgman A 
Published: July 2016

Abstract
During the period of tobacco smoke research from the early 1950s to the mid-1960s it was repeatedly asserted that a) tobacco and many tobacco components were involved in the pyrogenesis of polycyclic aromatic hydrocarbons (PAHs), several of which were reported to initiate tumors on the skin of laboratory animals and b) tobacco additives (flavorants, casing materials, humectants) were highly likely to be similarly involved in PAH pyrogenesis. Extensive knowledge on PAHs was deemed highly necessary because of their claimed importance in the smoking-health issue. The numerous assertions about the generation of PAHs in cigarette mainstream smoke (MSS) triggered extensive and intensive research both within and outside the Tobacco Industry to define the nature of the PAHs, their per cigarette MSS delivery amounts, their precursors, etc. It was not until 1960 that VAN DUUREN et al. (1) reported three specific aza-arenes in cigarette MSS that were asserted to be involved in smokers’ respiratory tract cancer. As noted in a recent Letter to the Editors (2), the presence of these three aza-arenes in tobacco smoke has never been confirmed. Between 1960 and 1965, other MSS components (phenols as promoters, polonium-210, N-nitrosamines, ciliastatic compounds) were asserted to be responsible for smoking related diseases. However, no major assertions were made that phenols, polonium-210, or the N-nitrosamines were derived from flavorants, casing materials, or humectants. Some investigators did report that several ciliastats were derived from added sugars and glycerol. The ciliastat proposal was drastically diminished in importance by the findings in the 1960s that only a relatively small proportion of the ciliastats reached the smoker's cilia. During that time, pertinent skills and competencies in research on tobacco smoke composition, particularly the PAH fraction, have been developed. Such skills permitted the isolation in crystalline form of 14 PAHs and the quantitation of these and many other PAHs. They were also used to put in perspective the pyrogenesis of PAHs from a) specific tobacco components, b) additives, and c) processed tobaccos (reconstituted tobacco sheet [RTS], expanded tobacco). R.J. Reynolds Tobacco Company (RJRT) pioneered the use of RTS (1953) and expanded tobaccos (1969) in cigarette blends and generated much previously unpublished data on the effect of such processed tobaccos on MSS composition.
Characterization of Virginia Tobaccos by Chemometric Methods
Authors: Apostolova E , Dagnon S , Edreva A 
Published: July 2016

Abstract
Leaf samples of different flue-cured Virginia tobacco varieties were analyzed and compared to a standard, the typical American Virginia cultivar K 326. Plants were grown in the Plovdiv region, Bulgaria, under conditions appropriate for Virginia varieties. The tobaccos were characterized by means of high performance liquid chromatography (HPLC) of polyphenols and capillary gas chromatography (CGC) of the neutral volatiles of essential oils, as well as by a sensory evaluation of color and aroma. All cultivars examined contained twelve polyphenol components in their HPLC profiles and differed only in quantitative aspects. Both qualitative and quantitative variations between the CGC profiles of essential oils of the cultivars were observed. The chromatographic profiles of polyphenols and essential oils were compared by the pattern recognition method (PRM) and used for calculating the similarity indexes (Is
,%) of the samples to the standard Virginia variety K 326. The chemometric data obtained are completely compatible with sensory evaluation of color and aroma. Based on the results obtained the tobaccos may be distinguished as: typical full-flavored Virginia - aromatic (Virginia 330); typical full-flavored Virginia - less aromatic (Virginia 0454); non-typical (filler type) Virginia (Virginia 42). The possibilities of the PRM for objective evaluation of color and aroma of Virginia tobaccos were demonstrated.
Bacillus thuringiensis (Bt) for the Control of Insect Pests in Stored Tobacco: A Review
Authors: Blanc M , Kaelin P , Gadani F 
Published: July 2016

Abstract
Among the insect species causing infestations and serious damages to stored commodities, the cigarette beetle, Lasiodermaserricorne (F.) and the tobacco moth, Ephestiaelutella (Hübner) are the major pests of both raw and manufactured tobacco. Post-harvest tobacco control is achieved through sanitation, insect monitoring, and fumigation with phosphine. However, insect resistance to phosphine and control failures have been reported, and increasing regulatory pressure is being exerted on fumigants. Biological control agents such as Bacillus thuringiensis (Bt) appear to be environmentally sound and potentially viable alternatives to chemical control. Bt is a bacterium that produces insecticidal crystal proteins during the sporulation phase and has been, for more than 40 years, the microorganism of choice for the biocontrol of phytophagous insect pests. It produces insecticidal crystal proteins that display specific activity against certain orders of insects and become active upon ingestion by the insect. Our laboratory has conducted extensive research and worldwide surveys to evaluate the presence of Bt in stored tobacco and has confirmed previous findings indicating that Bt may be considered part of the naturally occurring phylloplanemicroflora. Several Bt strains were isolated from tobacco and characterized by DNA and protein profiling. The insecticidal activity of selected strains and of two commercial products against the larvae of L. serricorne was determined by diet incorporation assays. Moreover, the stability of Bt spores and crystal proteins on cured tobacco leaves was assessed over a storage period of time of 30 months. Cigarette prototypes were made with Bt-treated tobacco. Standard cigarette and smoke evaluations did not show any significant difference between the test and control cigarettes. Although the tested Bt strains and products did not yield satisfactory levels of mortality at the required times and doses, the experimental results summarized in the present review indicate that B. thuringiensishas potential for the control of the cigarette beetle. The integration of conventional control approaches with novel systems based on biological agents with different modes of action should offer new avenues for the effective management of stored tobacco pests in line with integrated pest management (IPM) concepts.