bluuebunny/crossref_metadata_2025 huggingface dataset:
Reprogramación celular de embriones de Anthurium andraeanum por fitohormonas para micropropagación masiva
Authors: Mireles-Ordaz Julieta , Arellano-Perusquia Abraham , Espinal-Centeno Annie , Sánchez-Segura Lino , Estrada-Luna Andrés , Cruz-Ramírez Luis Alfredo
Published: July 2016

El género Anthurium incluye alrededor de 800 especies, las cuales son originarias de diversos países tropicales y subtropicales de América. Numerosos cultivos de estas especies de Anthurium son crecidos y comercializados debido a su gran popularidad como plantas ornamentales alrededor de todo el mundo, de las cuales la más popular es Anthurium andreanum. La reproducción sexual de estas plantas en invernaderos es difícil y toma mucho tiempo, lo cual representa una desventaja para su producción masiva y comercialización. La micropropagación in vitro ha emergido como una opción para sobrellevar dicha desventaja, hasta la fecha se han logrado avances parcialmente exitosos en la micropropagación en especies de Anthurium usando varios tejidos como explantes iniciales, incluyendo hojas, pecíolo, espádice, espata, brote lateral, meristemo apical y embriones somáticos, estos últimos previamente inducidos a partir de tejido diferenciado. Sin embargo, hasta ahora no hay reportes del uso de embriones cigóticos como tejido madre para la propagación masiva de estas plantas. En el presente estudio reportamos la formación de callos organogénicos a partir de embriones cigóticos inmaduros crecidos en medio MS suplementado con la combinación de 2 mg/l de ácido 2,4-diclorofenoxiacético (2,4-D) y 0.5 mg/l de 6-benzilamino-purina (BAP). Los resultados obtenidos demuestran que los embriones en proceso de desarrollo son altamente eficientes como explantes de origen para inducir la formación de tejido calloso de una manera rápida y fácil, dando en promedio 9 brotes  por callo y logrando una taza de sobrevivencia de las plantas del 90% en la fase de aclimatación.
Caracterización, modelación morfológica y análisis proximales de Opuntia ficus-indica y O. atropes durante las épocas de estiaje y lluvias
Authors: Pérez Sánchez Rosa Elena , Delgado Sánchez Lauro Antonio , García Saucedo Pedro Antonio , Pulido Secundino Juan , Ortiz Rodríguez Ruy
Published: July 2016

El objetivo fue caracterizar y modelar esquemáticamente los indicadores morfológicos (largo, ancho y grueso) y análisis proximal de las especies Opuntia atropes y O. ficus-indica durante la época de estiaje y lluvias. La investigación se realizó en la Facultad de Medicina Veterinaria y Zootecnia-UMSNH. Se obtuvieron cladodios de ambas especies y épocas del año de dos parcelas: parcela con prácticas culturales (PCP) y sin prácticas culturales (PSP). Se seleccionaron al azar 30 plantas/especie/parcela (15/época) y se muestrearon 60 cladodios: 50% por nivel (3er y 4to nivel); 40 de O. ficus-indica (20 en PCP y 20 en PSP), mientras que en O. atropes, fueron  20 cladodios en PSP. Se obtuvieron los indicadores morfológicos y bromatológicos/especie, nivel y época. El análisis estadístico se realizó mediante Modelos de Efectos Fijos y las diferencias estadísticas (α=0.05) entre parcelas, especies y época, se obtuvieron a través de medias ajustadas por mínimos cuadrados. Se encontró que el peso fresco, en estiaje fue mayor (P<0.05) en O. ficus-indica en PSP (1.59 ±0.25 kg) que en lluvias (0.85 ±0.18 kg); sin embargo, el valor nutricional aumentó en el estiaje, específicamente en extracto etéreo (2.97 ±1.04%) y en extracto libre de nitrógeno (64.17 ±2.36%). Los cladodios de O. atropes presentaron indicadores morfológicos de menor magnitud (P<0.05) que O. ficus-indica. Las características nutricionales de O. atropes fueron similares a O. ficus-indica en el estiaje: proteína cruda, 4.70 y 5.64%; extracto etéreo, 0.53 y 0.57%; extracto libre de nitrógeno, 42.18 y 40.82%  para O. atropes y O. ficus-indica, respectivamente. El peso fresco y la fibra cruda de O. ficus-indica disminuye en época de lluvias, mientras que el contenido de grasa y carbohidratos se incrementa en dicha época. Pero, la proteína cruda permanece estable en ambas épocas del año. Por su parte, O. atropes presenta características morfológicas de menor magnitud que O. ficus-indica. Sin embargo, sus características nutricionales son similares a esta, tanto en época de lluvias como en estiaje.
Complementación energética y proteínica en corderas Blackbelly x Pelibuey en pastoreo
Authors: Zamora Zepeda Raquel , Oliva hernandez Jorge , Hinojosa Cuéllar José Alfonso
Published: July 2016

Las corderas alimentadas con base en el pastoreo sin complementación alimenticia muestran una baja ganancia diaria de peso (GDP). Esta situación retrasa el crecimiento y puede influir la edad y peso vivo (PV) a la pubertad así como la edad a un PV especifico de sacrificio. El objetivo del estudio consistió en determinar la influencia de la complementación alimenticia (CA) sobre la eficiencia postdestete de corderas Blackbelly x Pelibuey (Bb x Pb). Se utiliza-ron 16 corderas. El diseño utilizado fue completamente al azar con dos factores con medidas repetidas en un factor. Los factores fueron CA [complementación alimenticia baja (CAB): 0.26 Mcal EM y 11.7 g PC/cordera /d y complementación alimenticia creciente (CAC): al inicio como CAB más incrementos de 0.13Mcal EM y 5.85 g PC/cordera /d cada 40 días] y número de período de evaluación (P). El modelo incluyó los efectos de CA, P y la interacción CA x P. Las variables estudiadas fueron PV y GDP. La CA no afectó (P>0.05) el PV y GDP. Sin embargo, P y CA x P influyeron en el PV y GDP (P
Potencial del techo verde, para ahorrar electricidad por aire acondicionado en la edificación.
Authors: Trujillo Samayoa Ruber , Rangel Martínez Yamile , Castañeda Nolasco Gabriel
Published: July 2016

Introducción: Tanto en México como en el mundo, más de tres cuartas partes de los insumos que se usan en la producción de electricidad provienen de fuentes no renovables, en una realidad donde los techos de las edificaciones son responsables de un consumo importante de electricidad por aire acondicionado. Por lo anterior, el objetivo fue evaluar el aspecto térmico y la eficiencia en el consumo de electricidad de dos aires acondicionados colocados, bajo el Techo de concreto reforzado y el Techo verde, y a la vez utilizar a la geometría analítica como herramienta de análisis en el consumo de electricidad.Método: Aunque inicialmente la metodología de la climatología dinámica, fue desarrollada para el análisis térmico, en este trabajo se retomó para aplicarlo al consumo eléctrico y conjuntándolo con el apoyo de la geometría analítica, a través de ecuaciones de recta que representan promedios anuales, se evidenció las diferencias en el consumo.Resultados: Los resultados obtenidos demuestran que el Techo verde amortigua mejor las temperaturas exteriores, reduce la oscilación térmica y; en el consumo eléctrico, con una diferencia promedio anual de un 28%, el Techo Verde consumió menos energía eléctrica por aire acondicionado.Discusión o conclusión: Se demuestra que conviene el uso de techos verdes en el sitio de estudio y posibilita su aplicación en otros contextos. El trabajo se realizó en periodos de temperaturas extremas opuestas, invierno de 2014 y primavera de 2015.
Puntos de equilibrio asintóticamente estables en nuevos sistemas caóticos
Authors: Casas-García K. , Quezada Téllez L. A. , Carrillo-Moreno S. , Flores-Godoy J. J. , Fernández Anaya Guillermo
Published: July 2016

En este trabajo se presentan 10 nuevos sistemas autónomos no lineales caóticos simples. Estos sistemas se encontraron utilizando el método Monte Carlo y tienen la característica de tener uno de sus puntos de equilibrio asintóticamente estables. Estos nuevos sistemas no tienen caos en el sentido de Shilnikov, pero sus diagramas de bifurcación muestran una ruta de periodo doble hacia el caos. Se calculó también la dimensión de Kaplan-Yorke, dando como resultado en un rango de 2-3.
Maíz, potencial productivo y seguridad alimentaria: el caso de San Nicolás de Los Ranchos, Puebla-México
Authors: Romero Arenas Omar , Damián Huato Miguel Ángel , Sangerman Jarquín Dora María , Reyes Muro Luis , Parraguirre Lezama José Filomeno Conrado , Orozco Cirilo Sergio
Published: July 2016

Se expone un modelo tecnológico para aumentar el potencial productivo de maíz de secano, validado con productores de San Nicolás de los Ranchos Puebla-México. Se calculó el Índice de Apropiación de Tecnologías Radicales (IATR) y el Grado de Empleo de Tecnologías Progresivas (GETP); se agruparon a los productores según su rendimiento para diseñar el modelo tecnológico y se estimó la seguridad alimentaria real y potencial. Se encontró que: en el manejo de maíz interaccionan innovaciones radicales y progresivas imperando las segundas; no hay relación directa entre el IATR y rendimientos, pero sí con el GETP; que 29% de los productores son eficientes; el 29% de los productores no poseen seguridad alimentaria y que si los productores de bajo y medio potencial productivo, aplicaran el patrón tecnológico de los productores eficientes, los rendimientos aumentarían, en promedio un 157% y 38%, respectivamente.
PVB/sepiolite nanocomposites as reinforcement agents for paper
Authors: Jankovic-Castvan Ivona , Lazarevic Slavica , Stojanovic Dusica , Zivkovic Predrag , Petrovic Rada , Janackovic Djordje
Published: July 2016

In order to improve the mechanical properties of paper, 1, 3 and 5 wt.% of
sepiolite were dispersed in a poly(vinyl butyral) (PVB) matrix and coated
onto the surface of schrenz (110 g m-2). Deagglomerated sepiolite nanofibers
in PVB matrix on paper surface were observed by scanning electronic
microscopy. The glass transition temperature of schrenz with PVB/sepiolite
coatings was not changed with increasing content of sepiolite. Two different
methods were used to evaluate the mechanical properties of the paper sample
reinforced with PVB/sepiolite nanocomposites: tensile testing and
nanoindentation. The values of breaking force and tensile energy absorption
of the reinforced paper samples obtained by tensile testing were increased by
up 10 %. The values of the reduced elastic modulus and hardness obtained by
nanoindentation were increased by up to 78 %. The best improvement of the
mechanical properties was shown by the paper sample coated with PVB/3 wt.%
sepiolite nanocomposite.
Is corruption good or bad for FDI? Empirical evidence from Asia, Africa and Latin America
Authors: Jalil Abdul , Qureshi Amina , Feridun Mete
Published: July 2016

This article revisits the relationship between corruption and Foreign Direct
Investment inflows in a panel of 42 countries from 1984 to 2012 using pooled
mean group estimator in a dynamic heterogeneous panel setting using
Westerlund and ARDL panel cointegration tests where the estimations are
carried out by three different estimators: the pooled mean group (PMG), mean
group (MG), and the dynamic fixed effect (DFE) estimators in order to examine
both the long- and short-term effects of corruption on FDI inflows. The
results suggest that corruption has a positive impact on FDI inflows in the
case of Asia and Africa; and a negative impact in the case of Latin America.
The effect of informal economy on income inequality: Evidence from Turkey
Authors: Elveren Adem , Özgür Gökçer
Published: July 2016

By considering the manufacturing pay inequality index as a proxy for overall
income inequality and a novel index for the informal economy, this study
analyzes the relationship between income inequality and the size of the
informal economy in Turkey for the first time during the period of 1963-2008.
For this purpose, we employ a time-series analysis with the Johansen
cointegration test, a vector error correction model and the Granger causality
tests. The findings suggest that while an increase in income inequality and
foreign trade competitiveness leads to an expansion of the informal sector,
unemployment has negative effects on the informal sector.
Vertical spillovers from multinational enterprises: Does technological gap matter?
Authors: Pittiglio Rosanna , Reganati Filippo , Sica Edgardo
Published: July 2016

Foreign direct investment (FDI) from Multinational enterprises (MNEs) can
augment the productivity of domestic firms insofar as knowledge ?spills over?
from foreign investors to local producers. The capacity of local companies to
exploit knowledge from MNEs can be affected by the technology gap between
foreign and local enterprises at both horizontal (in the same industry) and
vertical (in different industries) level. Whereas most of the empirical
literature has focused exclusively on the analysis of horizontal and backward
spillovers (i.e. between MNEs and local suppliers), the present paper also
examines the relationship between FDI-related spillovers and technological
gap in the Italian manufacturing sector at forward level (i.e. between MNEs
and local buyers). Results suggest that at both intra-industry and forward
level, the technological gap is of considerable importance for the spillover
effect, particularly in the case of low-medium gap.
Impact of the joint-stock reform of commercial banks on the effectiveness of monetary policy in China
Authors: Fang Xianming , Jiang Yu
Published: July 2016

Over the past decade, the Chinese government has conducted the joint-stock
reform of state-owned commercial banks. The joint-stock reform improves the
marketization level of the ownership structure of commercial banks and
consequently leads to impacts on the effectiveness of monetary policy. This
paper first presents the impacting mechanisms of the joint-stock reform of
commercial banks on the effectiveness of monetary policy and then constructs
an empirical model to test those impacts. The empirical results show that the
increasing degree of joint-stock reform of commercial banks enhances the
effectiveness of expansionary monetary policy but weakens the effectiveness
of contractionary monetary policy in China.
Antimicrobial activity of biochemical substances against pathogens of cultivated mushrooms in Serbia
Authors: Potocnik Ivana , Todorovic Biljana , Djurovic-Pejcev Rada , Stepanovic Milos , Rekanovic Emil , Milijasevic-Marcic Svetlana
Published: July 2016

Disease control with few or no chemicals is a major challenge for mushroom
growers in the 21st century. An alarming incidence of resistance to
antibiotics in bacteria, and to fungicides among mycopathogenic fungi
requires effective alternatives. Previous studies have indicated that various
plant oils and their components demonstrate strong antimicrobial effects
against pathogens on cultivated mushrooms. The strongest and broadest
activity to pathogens obtained from mushroom facilities in Serbia was shown
by the oils of oregano, thyme and basil. Five oils inhibited the growth of
pathogenic bacteria Pseudomonas tolaasii: wintergreen, oregano, lemongrass,
rosemary and eucalyptus. The essential oils of oregano, geranium and thyme
were considerably toxic to the pathogenic fungi Mycogone perniciosa,
Lecanicillium fungicola and Cladobotryum spp. The strongest activity against
Trichoderma aggressivum f. europaeum was shown by the oils of basil and mint.
Oils of juniper and pine showed neither inhibitory nor lethal effects on
mushroom pathogens. Although the fungitoxic activity of oils is not strong,
they could be used as a supplement to commercial productus for disease
control, which will minimize the quantity of fungicides used.
Incidence of viruses in highbush blueberry (Vaccinium corymbosum L.) in Serbia
Authors: Jevremovic Darko , Paunovic Svetlana , Leposavic Aleksandar
Published: July 2016

A large-scale survey for highbush blueberry (Vaccinium corymbosum L.) viruses
in Serbia was performed from 2011 to 2015. A total of 81 leaf samples from 15
locations were collected and analyzed for the presence of 8 viruses.
Serological ELISA assay was performed to determine the presence of: Blueberry
scorch virus (BlScV), Blueberry shock virus (BlShV), Blueberry shoestring
virus (BSSV), Blueberry leaf mottle virus (BLMoV), Tobacco ringspot virus
(TRSV) and Tomato ringspot virus (ToRSV). All samples were tested for the
presence of Blueberry red ringspot virus (BRRV) by PCR and for Blueberry
mosaic-associated virus (BlMaV) by RT-PCR test. The analyses confirmed the
presence of BlMaV in 8 (9.9%) samples and BRRV in 1 (1.2%) sample. No BlScV,
BlShV, BLMoV, BSSV, TRSV or ToRSV viruses were detected in any of the
analyzed samples.
Allelopathic tolerance of pea cultivars to Sorghum halepense L. (Pers.) extracts
Authors: Georgieva Natalia , Nikolova Ivelina
Published: July 2016

In order to evaluate the allelopathic effect of Sorghum halepense extracts on
germination and initial growth of six pea (Pisum sativum subsp. sativum,
Pisum sativum subsp. arvense) cultivars and to identify tolerant cultivars, a
laboratory experiment was conducted. The studied cultivars revealed different
levels of susceptibility to allelopathic impact of root and aboveground
biomass extracts of S. halepense. Root growth parameters (length and weight)
of the pea cultivars exhibited greater susceptibility to weed extracts than
stem parameters. The inhibitory effects of the extracts on germ length of P.
sativum ranged from 1.4% (cultivar Mir) to 45.0% (Kamerton), on germ weight -
from 3.5% (Pleven 4) to 42.9% (K-80), and on seed germination - from 11.8%
(Mir) to 31.3% (K-80). Total inhibitory effect, i.e. the impact of S.
halepense extracts on all studied parameters of P. sativum, revealed that the
cultivars Mir and Pleven 4 were the most tolerant. Growing such cultivars may
reduce weed damage. Low tolerance was manifested by the cultivar K-80, while
Modus, Glyans and Kamerton ranked intermediate. The cultivars with large-size
seeds or lower grain protein content were more affected by the depressing
effect of S. halepense extracts.
The Filling Value of Cigar Tobacco: Examination of Different Cutting Widths of Cigarillo Filling Tobacco / Die Füllfähigkeit von geschnittener Zigarreneinlage: Ergebnisse einer Untersuchung von Zigarillos mit Einlagen verschiedener Schnittbreiten
Authors: Halbye M. , Knudsen J.Y.
Published: July 2016

For the purpose of producing cigarillos of optimum filling value measurements have been taken by two instruments, i.e. the impact volumeter and the Borgwaldt compressimeter, in order to examine whether the respective methods are suitable for cigar tobacco. The authors intended to determine the optimum width of cut for the filling of cigarillos as well as the optimum weight conditioned by the width of cut under the different circumstances. The measurements were taken with widths of cut of 1, 1 ½, 2, 2 ½ and 3 millimetres. The data furnished by the two instruments showed a relation between width of cut and filling capacity. The measurements taken by means of the compressimeter were more precise than those taken by the impact volumeter. Allowance has to be made, however, for the fact that the conditions to which the tobacco is exposed in both instruments are not the same as those of manufactured cigarillos. There is a relation between the distribution of strand dimensions of cut tobacco and the compression volume. The compression volume increases with increasing proportions of coarse particles and decreases with increasing proportions of fine particles. Subjective manual estimation of the filling capacity by experienced examiners corresponds fairly to the results obtained by mechanical determination
Remarks about Corrections of Regulations for the Determination of Nicotine / Bemerkungen zur Korrektur der Vorschrift für die Nikotinbestimmung
Authors: Lipp G.
Published: July 2016

1. Dekadische Absorptionskonstante

2. Gravimetrische Bestimmung mit Kieselwolframsaeure

3. Säure für die Vordestillation

4. Filterwirkung
Examination of Cigarette Smoke Components: The Yield of Total Particulate Matter, Total Water, Pyridine, Nicotine, Phenol, Catechol, Scopoletin and Carbon Oxide in Cigarette Smoke in Correlation to Puff Number and Cigarette Filter - Betrachtungen über die Veränderung des Tabakrauches in der Cigarette: Die Ausbeute an Rohkondensat, Gesamtwasser, Pyridin, Nikotin, Phenol, Brenzcatechin, Scopoletin und Kohlenoxid im Cigarettenrauch in Abhängigkeit von der Zugnummer und vom Rauchfilter
Authors: Waltz von P. , Häusermann M.
Published: July 2016

Any smoke component is distributed over both the particulate and the gaseaus phases. The distribution is determined by a) the vapour pressure of the considered substance, b) its concentration in the smoke, and c) its physico-chemical affinity for the particulate phase. The availability of a substance in the gaseaus state, i. e. the condition for its selective removal by an appropriate filter, is therefore dependent on these factors. The experiments designed to study these relationships are based on three variables held each at several Ievels: :1. Test substances distinguishing themselves by the factors a), b), and c): Carbon monoxide, crude (moist) smoke condensate, total water, pyridine, total alkaloids, volatile phenols, catechol, and scopoletin. 2. These substances are determined in the smoke trapped separately per individual puffs. The composition of the smoke leaving the cigarette depends on the puff number, according to the factors a), b), and c). 3· Use of four different smoke filtration devices permitting the study of the availability of a given test substance or of its affinity to the filter material. The following expressions are used for the interpretation of the experimental results: The ratio of the yield of test substance to the yield of crude condensate; the coefficients of filtration of the test substance in both the tobacco rod and the experimental filter; the coefflcient of selectivity, defined as the difference between the respective coefficients of filtration for the crude condensate and for the test .substance. The results of the experimentation tend to confirm the initial hypothesis and give ,sufficient detailed information to permit the tentative establishment of a general scheme which allows to predict the selective behaviour of a particular ·smoke component, if its concentration in the smoke, its vapour pressure and its presumable affinity towards a given filter material are known. lt is further shown that a mathematical expression for the yield of a particular smoke component, as a function of the puff number, can be established on an empirical basis for carbon monoxide, · crude condensate, total alkaloids, catechol and scopoletin. The increase in the yield of carbon monoxide with the puff number is shown to be due to a CO loss through the permeable paper wrapper of the cigarette, this loss being smaller as the butt becomes shorter
A Dimensionless Measure of Filter Selectivity: Geometrical Factors in Cigaret Construction which Influence this Measure
Authors: Davis H. , George W.
Published: July 2016

A rational definition for characterizing the capacity of a cigarette filter to selectively modify the chemical composition of mainstream smoke is presented. The definition is related to the concept of separation factor as defined in chemical engineering and applied in the description of various unit processes. A number of numerical values for a wide range of cigarette filters currently found in the world market place are presented. The relative independence of the selectivity as defined in this paper upon tobacco types is demonstrated. Using a fixed filter construction in terms of amount and type of cellulose acetate fiber and plasticizer content, selectivity values are presented as a function of cigarette length and relative proportion of the cigarette which is allotted to the filter. Further, it is shown that selectivity appears to increase with length for given filter construction parameters. A limited amount of data regarding selectivity for weak acid components of mainstream smoke and certain gas phase components is presented as a characterization of dual filters currently on the US market
The Modification of Cigarette Smoke by Filter Tips
Authors: Williamson J. T. , Graham J. F. , Allman D. R.
Published: July 2016

One of the best known ways of modifying cigarette smoke is by the use of cigarette filters of various types. Filters are now being made from a variety of materials and, of recent years, have become more complex in structure and function. The authors consider the different ways in which different types of filters modify the chemical composition of the smoke showing some typical results. A new method of studying the range of higher boiling compounds in the smoke based on the volatilization of compounds trapped on a Cambridge Filter is discussed and information which this provides with different filter types is presented. Having shown the different action of the available range of filters as individuals, the possibilities of combining these in different ways to produce multiple filters and the degree of control of the smoke composition made possible as a result are discussed. If one examines the efficiency of any type of filter towards the whole range of substances in tobacco smoke from the permanent gases up to the high boiling compounds such as nicotine, one finds that the efficiency of the same filter varies widely according to the compound considered. Further, one finds that the pattern of efficiencies over the range of compounds is quite different between one filter and another. If, in the design of a filter cigarette, one wishes to emphasize or reduce various portions of the smoke it is possible to exercise a considerable degree of control by the use of suitable types of filter or combinations of filters. In addition to removing smoke constituents to varying degrees it is also possible to add desirable constituents to the smoke such as flavours by means of filters and the analytical technique mentioned above is very suitable for assessing the amount of such flavouring material which is actually present in the cigarette smoke
The Use of Photoelectric Cells for Measuring the Static Duration of Combustion in Cigarettes/Anwendung von Photoleitern zur Bestimmung der statischen Branddauer von Cigaretten
Authors: Lubrano A. , Carugno N.
Published: July 2016

The semi-automatic assembly presented here (photoelectric cells used to measure the static duration of combustion in cigarettes) resembles in principle the design published by Wiley and Holmes. Essentially it consists of an electrical start-stop device timed by 2 signals activated by the movement of the glowing zone through a thermo-transductor field. It differs from the earlier design in that, instead of a hot bi-metallic thermocoupling, it uses a photo-transistor very selective in IR (maximum response 1.55 mµ, with a 50 % drop for 0.8 and none for 2 mµ). The device also has a mechanical system for holding the cigarette and positioning the phototransistors, and an electrical cigarette lighting system. The apparatus is set up for simultaneous control of 5 cigarettes.
Smoke Streams in Cigarettes / Die Strömungsverhältnisse in Cigaretten
Authors: Meyer-Abich K.M.
Published: July 2016

According to the formulae
Preparation and Properties of N-Nitroso Derivatives of Tobacco Alcaloids / Darstellung und Eigenschaften von N-Nitroso-Verbindungen der Tabakalkaloide
Authors: Neurath G. , Dünger M.
Published: July 2016

Preparation and properties of N-nitroso derivatives of nornicotine, anabasine, metanicotine and dihydrometanicotine are described. The corresponding N-amino compounds were obtained by reduction and were then transformed into 5-nitro-2-hydroxy-benzal derivatives for identification. Characteristics and spectra of the said compounds are indicated.
A Contribution to the Sifting Analysis of Tobacco / Ein Beitrag zur Siebanalyse des Tabaks
Authors: Hübschen L.
Published: July 2016

After considering the sifting analysis of tobacco in general, the author examines the factors which have an influence on the result. It is shown that a comparative sifting analysis gives reproducible results only if the water content of tobacco, the type of sifting machine, the size of the sieve holes, and the length of sifting are indicated. It is recommended to institute standards to this end. The described practical application shows that representative and discussible results can be obtained under uniform conditions.
An Improved Sifting Machine for the Fractionation of Tobacco / Eine verbesserte Siebmaschine zur Fraktionierung von Tabakgut
Authors: Kruszynski A.J. , Larsen H.
Published: July 2016

A sifting machine for cigar filling tobacco is described which includes four different sieves and a conveyor belt continuously supplying the apparatus with tobacco. A first sieve ( Ø of holes: 15 mm) rids the flux of the largest tobacco pieces. The remaining flux of tobacco is received on a second level with three successive zones having increasing perforation diameters (2. 6 and 10 mm). In this way five different classes of product are obtained. As an example the following were obtained during an experiment: > 15 mm: 29 %, 15-10 mm: 23 %, 10-6 mm: 28 %, 6-2 mm: 18 %, << 2 mm: 2 %. Results obtained for stripped and cut cigar filling tobacco as well as for stripped and cut cigarette tobacco are indicated and discussed with regard to dispersion and reproducibility.
Chemical Studies on Tobacco Smoke: I. The Quantitative Determination of Indoles in Cigarette Smoke
Authors: Hoffmann D. , Rubin J.
Published: July 2016

A method for the quantitative determination of indole and alkylated indoles in cigarette smoke is described. The analysis consists of distributions between n-hexane / methanol-water (4:1); n-hexane / methanol-water (1:2); column chromatography on Florosil and gas chromatographic separation on 20 % Apiezon L at 155°C. Quantitative data are secured by use of C14-labelled indole as internal standard. In the smoke of an 85 mm blended United States cigarette without filter tip were determined 13.9 µg indole, 14.0 µg skatole, 4.2 µg 3-ethylindole, and 0.21 µg 3-n-propylindole. The presence of an admixture of dimethylindoles was tentatively established; their concentration was below 0.03 µg per cigarette
The Direct Preparation of Cigarette Smoke Condensate by High Velocity Impaction
Authors: Mathewson H. D.
Published: July 2016

A method is described for the collection of smoke condensate by high-velocity impaction. Analytical and mass-condensate versions are considered, and the results of analyses on their product are reported and discussed. The potential scope of applications of this type of collector are also indicated
A Method for the Determination of Nicotine in Lung Tissue of Hamsters / Eine Methode zur Bestimmung des Nikotins in Hamsterlungen
Authors: Elmenhorst H.
Published: July 2016

A method for the determination of nicotine in lung tissue is presented. The nicotine is extracted from homogenized lung tissue by means of a mixture of hydrochloric acid and methanol. It is then spectrophotometrically determined after the disturbing accompanying substances have been eliminated by a preliminary acid steam distillation. The method's inferior limit of detection is 40 µg of nicotine contained in 3 lungs, which corresponds to 17.7 µg of nicotine per gramme of lung tissue. In the case of nicotine contents of 50 µg per analytical procedure the standard deviation of the method was found to be 1.7 µg, and the resulting coefficient of variation was calculated to be 3.4 %. The procedure is simple and therefore suitable for the study of numerous samples. The exposure of hamsters to inhaled raw cigarette smoke revealed that the nicotine content of lungs of experimental animals augments with the number of burnt cigarettes and the duration of inhalation. The reproducibility of Dontenwill's inhalation procedure was tested and proved to be satisfactory. The coefficient of variation within two series of inhalation experiments was found to be between 4.1 and 5.2 %
Examination of Volatile Bases in Cigarette Smoke / Untersuchung der Flüchtigen Basen des Tabakrauches
Authors: Neurath G. , Dünger M. , Gewe J. , Lüttich W. , Wichern H.
Published: July 2016

The smoke of cigarettes with high base content was examined for primary and secondary bases. As 4'-nitro-azobenzenecarboxamides- (4) (NABSA) the bases were separated by column and thin-layer chromatography and identified by melting points, RF-values, IR-spectra, retention times, mass-spectra, and elemental analyses. 27 primary and secondary bases were isolated and 24 of them identified. For the first time n-propylamine, n-butylamine, iso-butylamine, iso-pentylamine, b-phenethylamine, methyl ethylamine, diethylamine, methyl-b-phenethylamine, 1,2,5,6-tetrahydropyridine, aniline, 3-methylaminopyridine, and dihydrometanicotine were detected in cigarette smoke. Earlier results about the presence of pyrrolidine, piperidine, and 2-methylpyrrolidine in smoke could be confirmed. Presumably methyl-n-butylamine and methyl-iso-butylamine are to be found in tobacco smoke. One further amine was not identified.
Examination of Volatile Bases in Different Types of Tobacco II / Untersuchung der Flüchtigen Basen des Tabaks, ll
Authors: Neurath G. , Krull A. , Pirmann B. , Wandrey K.
Published: July 2016

An examination of the volatile bases in different types of tobacco was carried out. Virginia and Oriental types of cigarette tobaccos and a typical Burley tobacco were examined qualitatively and a blend of black tobacco was also analysed quantitatively. Ethylamine, iso-butylamine, b-phenethylamine, dimethylamine, methylethylamine, methyl-n-propylamine, methyl-b-phenethylamine, and 1,2,5,6-tetrahydropyridine were identified in tobacco for the first time. Among the tobacco bases identified ammonia, methylamine, iso-pentylamine, pyrrolidine, and piperidine were already known. Ammonia is the main component of the volatile bases. As to quantity the minor alkaloids nornicotine and anabasine are followed by methylamine and pyrrolidine. The quantitative relations of the decarboxylated amino acids correspond to that of amino acids contained in tobacco hydrolysates.
Dimethyl Sulfide in Cigarette Smoke - On the Origin of the Sulfur Compounds of Cigarette Smoke and on Their Possible Contribution to its Overall Flavor and Aroma
Authors: Philippe R.J.
Published: July 2016

Dimethyl sulfide has been isolated from cigarette smoke by a combination of adsorption and partition gas chromatographic techniques. Positive identification of dimethyl sulfide was obtained by infra-red spectrophotometry, mass spectrometry and gas chromatographic retention times. Both infra-red and mass spectra are presented and their most important features are discussed. Based on gas chromatographic measurements, a semiquantitative estimation of the amount of dimethyl sulfide in cigarette smoke is given. A list of the sulfur compounds identified up to now in cigarette smoke is presented as well as some discussion about their possible origin. After some evidence given on the importance of sulfur compounds on the flavour of several natural products and of some synthetic compositions, the question is raised as to the possible effect of these sulfur compounds on the overall flavour and aroma of cigarette smoke.
Model Pyrolysis - The Study of Cellulose
Authors: Robb E.W. , Johnson W.R. , Westbrook J.J. , Seligman R.B.
Published: July 2016

The purpose of this study was to learn how cellulose pyrolysis was affected by changes in atmospheres, by varied pyrolysis temperatures, by the addition of inorganic materials, and by chemical modifications of the cellulose molecule. These studies have led to the hypothesis that cellulose can pyrolyse by two different modes to form B(a)P. Large quantities of B(a)P can be formed by high temperature (850°C) isothermal pyrolysis of cellulose via a very efficient gaseous reaction route. In this reaction the B(a)P yield decreased in the presence of iron, cobalt, and nickel while the yield increased with increasing temperatures and with the introduction of oxygen into the system. In contrast, graduated heating experiments demonstrated that B(a)P began to form at 450°C. This reaction was inefficient with respect to B(a)P yield and was unaffected by the presence of metals. The B(a)P precursors were hypothesized to be nonvolatile, being formed via a solid state decomposition of cellulose and involving the generation of free radicals. This reaction was inhibited by the presence of nitric oxide or salts generating nitric oxide. Additionally, oxidation of the cellulose molecule at the C6 position produced a decreased B(a)P yield.
The Measurement of Smoking Parameters Using Transducers/Zur Messung von Abrauchparametern mit Hilfe von Messgrößenumformern
Authors: Lorenz H.W. , Seehofer F.
Published: July 2016

The suitability of electric measuring methods making use of transducers has been tested for the smoking parameters puff duration, draw resistance, puff profile and puff volume. The procedures proved to be accurate, reproducible and technically simple and are, in our opinion, appropriate for calibrating smoking machines and for controlling the said parameters during the smoking process.
The Spectrophotometric Determination of Formaldehyde in Whole Smoke/Eine spektralphotometrische Methode zur Bestimmung von Formaldehyd im Vollrauch von Cigaretten
Authors: Stauffer H.P. , Bourquin J.
Published: July 2016

The quantitative determination of formaldehyde in the gas phase of cigarette smoke does not permit any conclusion about the actual level in whole smoke. This is due to the fact that a Cambridge filter charged with smoke condensate absorbs up to 50 % of the volatile aldehydes from the gas phase. A simple method is presented making possible the estimation of formaldehyde in whole cigarette smoke. The procedure is based on the Hantzsch reaction between formaldehyde, acetylacetone and ammonium ion in an aqueous buffer solution. The reaction product, 3,5-diacetyl1,4-dihydrolutidine, has an absorption maximum at 412 nm and is measured spectrophotometrically. The operations are simple and there are no separation steps required. Reproducibility is excellent and interference by other carbonyl compounds can be neglected. Acetaldehyde in concentrations 10 times higher than formaldehyde interferes to less than 1 %. Different types of cigarettes have been analysed with respect to their delivery of formaldehyde. Values found range from 40 to 90 µg per cigarette. The concentrations found in whole smoke are significantly higher than the values cited in the Iiterature for gas phase formaldehyde
Effect of Tobacco Smoke Condensates on Ascorbate
Authors: Bilimoria M.H. , Nisbet M.A.
Published: July 2016

Ethanolic extracts of tobacco and tobacco smoke contain compounds capable of accelerating the oxidation of ascorbate. Using a polarographic technique, smoke from cigarettes, cigars and pipe were examined for oxidising properties. Smoke from Virginia cigarettes showed greater activity than that from blended cigarettes, while smoke from cigars and pipes had even lower activity. The reaction of ascorbate and smoke has been shown by EPR to involve a radical intermediate.
Gaschromatographic Determination of Carbon Monoxide in Exhaled Air and Blood/Gaschromatographische Bestimmung von Kohlenmonoxid in der Ausatmungsluft und im Blut
Authors: Grieder K. , Buser H.
Published: July 2016

The gas chromatographic method described here has been developed for the determination of low carbon monoxide concentrations in air and blood. For the determination in expired air, a 4 ml sample is injected in a molecular sieve 13X column, where the CO is separated from the other gases. The CO is then hydrogenated to methane over a nickel catalyst column heated to 290°C, and the methane is determined with a flame ionization detector. The limit of detection is 0.1 ppm CO in a total sample volume of 4 ml. The standard deviation per single determination is 0.04 to 0.08 ppm CO in the CO concentration range 0.2 to 10 ppm. For the determination in blood, the CO is liberated from the HbCO complex with K3[Fe(CN)6], transferred into a molecular sieve 5A column which is cooled in liquid nitrogen, and then swept into the gas chromatographic set-up used for the determination of CO in air. 0.05 % HbCO can still be detected in a 0.1 ml blood sample. The standard deviation per single determination is 0.02 % HbCO for a total of 1 % HbCO in the blood sample.
The Determination of Thiodan and Thiodan Sulphate on Tobacco and in Smoke Condensate
Authors: Hengy H. , Thirion J.
Published: July 2016

A gas chromatographic method was developed for the quantitative determination of a- and b-thiodan and thiodan sulphate on tobacco and in smoke condensate in concentrations as Iow as 0.01 parts per million. A survey was made of the thiodan and thiodan sulphate content of leaf tobacco and cigarettes. Thiodan and thiodan sulphate residues in leaf tobacco were found to amount to between 0.02 and 0.3 ppm and to between less than 0.02 and 0.05 ppm respectively. Cigarettes manufactured from Virginia tobacco were found to contain between 0.1 and 0.2 ppm of thiodan and less than 0.05 ppm of thiodan sulphate. The transfer rate of thiodan and thiodan sulphate from cigarette tobacco into the mainstream smoke ranged from 14.5 % to 16.3 %
Analytical Examination of Gas Phase Condensate of Cigarette Smoke - Analytische Untersuchungen an Gasphasenkondensat
Authors: Schüller D. , Drews C.J. , Harke H.P.
Published: July 2016

By the use of gaschromatographic and mass spectrometric methods gas phase condensate from cigarette smoke, isolated on a preparative scale, has been compared with the native gas phase from the smoke of the same cigarettes and investigated for qualitative composition. With regard to composition, there is a satisfactory conformity between both mixtures of substances. It has been possible to identify or to characterize more than 60 constituents
Effects of irrigation, Nitrogen Fertilization, Plant Population and Variety on the Physico-Chemical Properties of Maryland Tobacco: I. Agronomic Effects
Authors: Brown G.W. , McKee C.G. , Street O.E.
Published: July 2016

Irrigation experiments on Maryland tobacco have been conducted since 1955 on Monmouth fine sandy loam, a typical tobacco soil of Southern Maryland. An overhead sprinkler system was employed. Moisture levels in the soil were studied, using Bouyoucous gypsum blocks and tensiometers. The following conclusions were made from this study:

1. In a year of severe drought, 1966, ample irrigation increased yields, unit value and total value. Irrigated yields were 175 per cent of non-irrigated; unit value was 141 per cent, and total value of irrigated tobacco was 247 per cent of non-irrigated.

2. Nitrogen fertilizer rates of 100.9, 134.5 and 168.1 kg ha were used. Under irrigation, gains in yield and total value, and some loss in unit value were obtained from the first added increment of fertilizer nitrogen above the base amount. Addition of the second increment produced smaller gains in yield, a greater loss in unit value, and losses in total value.

3. In the absence of irrigation, the supply of soil water could limit nitrogen assimilation by the plants. The higher rates of nitrogen fertilization were effective in increasing yield and total value over the lower increments. Even unit value was not adversely affected.

4. The Wilson broadleaf variety of Maryland tobacco consistently outyielded the Catterton medium broadleaf variety, but due to lower unit value, probably caused by darker colours, it had a lower total value.

5. Plant populations of about 18000 per hectare produced increased yields and gross return over a population of about 12000. Populations of 24000 plants per hectare were excessive in most cases, and produced losses in yield and unit value.

6. Comparative response to irrigation depends on severity of drought, but late depletion of soil moisture levels may prevent the full potential development of the crop, and result in lower yields and total value.
Microscopic Examination of Fibres Used for the Manufacture of Cigarette Papers/Mikroskopische Untersuchungen zur Stoffzusammensetzung von Cigarettenpapieren
Authors: Jodl R. , Krüll F.
Published: July 2016

The present paper shows and discusses microphotographs of fibres used for the manufacture of cigarette papers as well as such photographs disclosing the composition of cigarette papers.
An Automated Procedure for the Determination of Ammonia in Tobacco
Authors: Collins P.F. , Lawrence W.W. , Williams J.F.
Published: July 2016

A procedure for the automated determination of ammonia in tobacco has been developed. Ammonia is extracted from the ground tobacco sample with water and is determined with a Technicon Auto Analyser system which employs separation of the ammonia through volatilization followed by colourimetry using the phenate-hypochlorite reaction. The procedure has been applied to a variety of tobaccos containing from 0.02 to 0.5 % ammonia with an overall relative standard deviation of 2 %. The accuracy of the procedure as judged by recovery tests and by comparison to a manual distillation method is considered adequate
Composition Studies on Tobacco: XLVI. Attempts to Modify Selected Biochemical Properties of Cigarette Smoke by the Use of Specially Treated Filters
Authors: Benedict R.C. , Stedman R.L. , James R.L.
Published: July 2016

Aqueous solutions of cigarette smoke produced by collecting smoke in dilute buffer were monitored during puffing for alterations in redox potential and pH. These solutions were examined subsequently for their inhibitory effect on yeast alcohol dehydrogenase, their reaction with model disulfide and sulfhydryl compounds, and their reaction with the colourimetric oxidation-reduction indicator 2,6-dichlorophenol indophenol. These properties were selected to indicate possible biochemical reactions of smoke, and to distinguish between alternative theories for observed enzyme inactivation. Previous experiments had indicated that smoke constituents that react with sulfhydryls might be responsible for such behaviour and that such constituents might be removed selectively by filter agents. Cellulose cottons treated to introduce sulfhydryl and/or ion-exchange groups were employed as filter additives, and the smoke solutions were examined for alterations in their reactivity with the above tests. Sulfhydryl reactivity appears to be too slow for effective selective filtration of such reactants from tobacco smoke. The various tests are evaluated on the basis of the contribution of the two phases; the vapour phase contains the components affecting pH, aldehyde content, and reactions with disulfides, and the particulate matter phase contains the components mainly affecting the remaining tests
Determination of Methylcyclopentenolone and Ethylcyclopentenolone in Cigarette Smoke and Latakia Tobacco/Nachweis von Methylcyclopentenolon und Aethylcyclopentenolon in Cigarettenrauch und Latakiatabak
Authors: Elmenhorst H.
Published: July 2016

3-Methyl-2-cyclopentene-2-ol-1-one (I) and 3-ethyl-2-cyclopentene-2-ol-1-one (II) were identified as new tobacco smoke constituents by gas chromatography and mass spectrometry. After clean-up by thick-layer and thin-layer chromatography and conversion into the methylenolethers by reaction with methanol and HCl, the methylethers of (I) and (II) were identified by high resolution gas chromatography on glass capillary columns and mass spectrometry. The concentration of (I) in tobacco smoke varies according to the tobacco type. Oriental, Virginia and Burley tobaccos were compared. The amounts of (I) and (II) in the smoke of the Oriental tobaccos were at least 0.12 mg/cigarette and 0.048 mg/cigarette respectively. Traces of (I) and (II) were also found in Latakia tobacco. (I) itself has a characteristic aroma of ''burnt sugar'' and a taste which can be described as maple-licorice with a suggestion of walnut. This means that (I) is a flavour constituent of tobacco smoke. But more interesting is the fact that (I) acts as a flavour enhancer and has a modifying effect on the flavour produced by phenols, which results in a ''smoky'' rather than a ''phenolic'' or ''cresotic'' character. We think that substances like the two compounds (I) and (II) found by us are of general importance for the basic smoky flavour of cigarette smoke