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Highly branched alkanes exhibit enhanced free volume relative to their straight chain analogues, leading to the increased solubility of sparingly soluble gases, such as N2, as well as lower hydroca...

The conclusions of the European Food Safety Authority (EFSA) following the peer review of the initial risk assessments carried out by the competent authorities of the rapporteur Member State Italy and co‐rapporteur Member State France for the pesticide active substances that are Straight Chain Lepidopteran Pheromones (SCLPs) and the considerations as regards the inclusion of the substances in Annex IV of Regulation (EC) No 396/2005 are reported. The context of the peer review was that required by Commission Implementing Regulation (EU) No 844/2012, as amended by Commission Implementing Regulation (EU) No 2018/1659. The conclusions were reached on the basis of the evaluation of representative uses of some SCLPs as semiochemicals used to protect grapes, pome fruits, walnuts, rice and any other crop (where Chilo suppressalis may be a pest) (all field uses). The reliable end points, appropriate for use in regulatory risk assessment are presented. Missing information identified as being required by the regulatory framework is listed. Concerns are identified.

Straight-chain alkanes (SCA) as collectors can effectively enhance the floatability of molybdenite. In a previous study, SCA were found to have an excellent adsorption effect on the molybdenite [001] surface (MS001), but they exhibited no adsorption behavior on the molybdenite [100] surface (MS100). However, other studies have shown that SCA could adsorb on MS100. In this paper, the underlying cause of this contradictory conclusion was identified by molecular dynamics simulation. The results show that SCA could adsorb both MS001 and MS100. However, at low SCA dosages, SCA have a strong interaction with MS001 but desorb quickly on MS100. This leads to the selective adsorption of SCA on MS001. As SCA’s concentration gradually increases, the selective adsorption behavior of SCA on MS001 will be disrupted. Excessive SCA concentration will lead to its adsorption at MS100.

NMR spectroscopy was used to measure hydrocarbon chain branching variability in meibum with age, gender and Meibomian gland dysfuction (MGD). A cohort of 65 meibum donors without dry eye and 31 donors with MGD was studied. Heteronuclear 2D NMR was used to confirm CH3 resonance assignments allowing us to positively identify 23 of the 27 proton resonances of cholesteryl ester and 1H resonances due to straight chain, iso-branched and anteiso-branched hydrocarbons. Meibum from donors without dry eye contained 57 ± 1% straight-chains, 23 ± 1% iso-branched chains and 20 ± 1% anteiso-branched hydrocarbon chains. Compared with meibum from donors without dry eye, meibum from donors with MGD contained less, 50 ± 2% straight-chains, more, 32 ± 2% iso-branched chains and the same amount, 18.0 ± 0.07%, of anteiso-branched hydrocarbon chains. Meibum hydrocarbon chain branching did not change with age between 22 and 68 years of age, nor was it influenced by gender. Based on previous studies, one would expect anteiso-branched chains would contribute to lowering the phase transition temperature of meibum, decrease the elasticity of the tear film lipid layer and increase the molecular area and spreading of meibum on the surface of the eye. Although we speculate that the observed differences in iso-chain branching do not influence tear film stability or rheology, the speculation has yet to be tested.

Lipidomics is advantageous in the study of sebum perturbations occurring in acne. An extended evaluation of the sebum lipid profiles in acne-prone sebaceous areas is lacking in dark skin. Yet, there is a void space in understanding how the building blocks of sebum lipids, i.e. individual fatty acids (FAs), are intertwined with acne-prone skin. We aimed to determine the sebum lipidome in facial areas of adolescents with and without acne in Nigeria. A cross-sectional analytical study was conducted in 60 adolescents/young adults divided in 30 acne patients (15F, 15M) and 30 age and sex-matched controls. Sebum samples obtained from foreheads and cheeks were analysed separately by gas chromatography–mass spectrometry (GCMS) and thin layer chromatography (HPTLC). Distributions of sebum components were investigated with multivariate ANOVA-simultaneous component analysis (ASCA). Sebum incretion in acne was paralleled by significantly higher abundance of triglycerides, wax esters, and squalene together with monounsaturated FAs (MUFAs), and straight chain saturated FAs (SFAs), especially those with odd-carbon chain, i.e. C13:0, C15:0, and C17:0. Profiling weight/weight percentage individual components revealed that in acne the free FAs (FFAs) array was shifted towards higher relative abundance of the SFAs C15:0, C16:0, and C17:0 and lower percentage of the anteiso-branched FFAs with 12, 14, 16, and 18 carbons. In acne patients, MUFAs and PUFAs were quantitatively increased and decreased on foreheads and cheeks, respectively. Relative abundance of fatty alcohols was decreased in acne independent on the site. The results indicated that acne associates with site-specific derangement of the pathways regulating the balance among odd straight-chain and branched-chain SFAs, MUFAs, including sapienate (C16:1n-10), PUFAs, and squalene.

Following a request from the European Commission, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of 26 compounds belonging to chemical group 3 (α,β‐unsaturated straight‐chain and branched‐chain aliphatic primary alcohols, aldehydes, acids and esters). They are all currently authorised as flavours in food. The FEEDAP Panel was unable to perform the assessment of non‐2(cis)‐en‐1‐ol [02.112] in the absence of data on its purity. The FEEDAP Panel concludes that hex‐2‐en‐1‐ol [02.020], pent‐2‐en‐1‐ol [02.050], 2‐dodecenal [05.037], nona‐2,4‐dienal [05.071], trans‐2‐nonenal [05.072], hex‐2(trans)‐enal [05.073], 2,4‐decadienal [05.081], hepta‐2,4‐dienal [05.084], deca‐2(trans),4(trans)‐dienal [05.140], dodec‐2(trans)‐enal [05.144], hept‐2(trans)‐enal [05.150], non‐2‐enal [05.171], undec‐2(trans)‐enal [05.184], trans‐2‐octenal [05.190], trans‐2‐decenal [05.191], tr‐2, tr‐4‐nonadienal [05.194], tr‐2, tr‐4‐undecadienal [05.196], hex‐2(trans)‐enyl acetate [09.394] and hex‐2‐enyl butyrate [09.396] are safe at the proposed maximum use level of 5 mg/kg feed for all animal species; nona‐2,6‐dien‐1‐ol [02.049], trans‐2, cis‐6‐nonadien‐1‐ol [02.231], nona‐2(trans),6(cis)‐dienal [05.058], nona‐2(trans),6(trans)‐dienal [05.172], allyl heptanoate [09.097] and allyl hexanoate [09.244] are safe at the proposed normal use levels of 1 mg/kg complete feed for all animal species. No safety concern would arise for the consumer from the use of these compounds up to the highest safe levels in feed. In the absence of studies to assess the safety for the user, the FEEDAP Panel cannot conclude on the safety for the users when handling the additives. No environmental risk is foreseen for these compounds at the concentrations considered safe for the target species. Since the 25 compounds are used in food as flavourings and their function is essentially the same as that in food, no further demonstration of efficacy is necessary.

Oxidative stress is associated with numerous health conditions and disorders, and aldehydes are known biomarkers of oxidative stress that can be non-invasively measured in exhaled human breath. Few studies report breath aldehyde levels in human populations, and none claim participant numbers in the hundreds or more. Further, the breath community must first define the existing aldehyde concentration variance in a normal population to understand when these levels are significantly perturbed by exogenous stressors or health conditions. In this study, we collected breath samples from 692 participants and quantified C(4)–C(10) straight chain aldehyde levels. C(9) aldehyde was the most abundant in breath, followed by C(6). C(4) and C(5) appear to have bimodal distributions. Post hoc, we mined our dataset for other breath carbonyls captured by our assay, which involves elution of breath samples onto a solid phase extraction cartridge, derivatization and liquid chromatography-quadrupole time of flight mass spectrometry (LC-qTOF). We found a total of 21 additional derivatized compounds. Using self-reported demographic factors from our participants, we found no correlation between these breath carbonyls and age, gender, body mass index (BMI), ethnicity or smoking habit (tobacco and marijuana). This work was preceded by a small confounders study, which was intended to refine our breath collection procedure. We found that breath aldehyde levels can be affected by participants’ using scented hygiene products such as lotions and mouthwashes, while collecting consecutive breath samples, rinsing the mouth with water, and filtering inspired air did not have an effect. Using these parameters to guide our sampling, subjects were instructed to avoid the prior conditions to providing a breath sample for our study.

Straight-chain alkanediols such as ethylene glycol are commonly found in our daily life as they are used to produce cosmetics, antifreezes, polyesters and polyurethanes. In this article, we report on the promising potential use of straight-chain alkanediols for rewritable full-colour imaging applications by the preparation of glassy cholesteric liquid crystals (G-CLCs). A series of straight-chain alkanediol derivatives possessing two cholesteryl groups through carbonate ester linkages (Cn-DiCh) showed thermotropic cholesteric liquid crystal phase with visible reflection. The thermally induced shifting ranges of reflection peaks were dependent on the central carbon chain length (n) of Cn-DiCh. Although the pristine Cn-DiCh showed narrow wavelength ranges of the reflection peaks by changing the temperature, we successfully prepared a mixture of two different kinds of Cn-DiCh at their equivalent weight ratio, which exhibited the reflection peak shift throughout a wide visible-wavelength range between 400 nm and 850 nm. Moreover, the binary mixtures of Cn-DiCh were rapidly cooled from the CLC temperatures to 0°C, whereupon the reflection colours could be preserved even at room temperature over 2 months. Such rapid cooling treatment enabled the straightforward preparation of solid-state G-CLCs with visible reflection characteristics, thereby leading to the applications of rewritable full-colour imaging media.

Low-dimensional halide perovskites have recently attracted intense interest as alternatives to the three-dimensional (3D) perovskites because of their greater tunability and higher environmental stability. Herein, we present the new homologous 2D series (NH3CmH2mNH3)(CH3NH3)n−1PbnI3n+1 (m = 4–9; n = 1–4), where m represents the carbon-chain number and n equals layer-thickness number. Multilayer (n > 1) 2D perovskites incorporating diammonium cations were successfully synthesized by the solid-state grinding method for m = 4 and 6 and by the solution method for m = 7–9. Structural characterization by single-crystal X-ray diffraction for the m = 8 and m = 9 series (n = 1–4) reveals that these compounds adopt the Cc space group for even n members and Pc for odd n members. The optical bandgaps are 2.15 eV for two-layer (n = 2), 2.01 eV for three-layer (n = 3), and 1.90 eV for four-layer (n = 4). The materials exhibit excellent solution processability, and casting thin-films of the n = 3 members was successfull...

Biomedical research in areas such as metabolic disorders, neuromodulatory, and immunomodulatory conditions involves lipid metabolism and demands a reliable and inexpensive method for quantification of short chain fatty acids (SCFAs). We report a GC-MS method for analysis of all straight-chain and branched-chain SCFAs using pentafluorobenzyl bromide (PFBBr) as derivatization reagent. We optimized the derivatization and GC-MS conditions using a mixture containing all eight SCFA standards, i.e., five straight-chain and three branched-chain SCFAs. The optimal derivatization conditions were derivatization time 90 min, temperature 60 (°)C, pH 7, and (CH(3))(2)CO:H(2)O ratio 2:1 (v:v). Comparing the performance of different GC column configurations, a 30 m DB-225ms hyphenated with a 30 m DB-5ms column in tandem showed the best separation of SCFAs. Using the optimized experiment conditions, we simultaneously detected all SCFAs with much improved detection limit, 0.244 - 0.977 μM. We further applied the developed method to measure the SCFAs in mouse feces and all SCFAs were successfully quantified. The recovery rates of the eight SCFAs ranged from 55.7% to 97.9%.

espanolIntroduccion: el dolor lumbar es una condicion con mayor indice de consulta en los servicios de salud. En trabajadores de oficina tambien existe una alta prevalencia, por lo tanto es necesario generar planes de intervencion desde la prevencion primaria para mejorar la condicion de salud de esta poblacion. Objetivo: determinar los efectos de un programa de ejercicio sobre el dolor lumbar en trabajadores de oficina. Materiales y metodos: se realizo un programa de ejercicio en 17 trabajadores de oficina en una empresa de Bogota durante cuatro semanas basado en el fortalecimiento de los musculos abdominales, profundos del cuello y el estiramiento de la cadena recta posterior. Se evaluo la evolucion del dolor lumbar y la incapacidad laboral por medio del cuestionario de Roland Morris, los instrumentos se aplicaron al finalizar las cuatro semanas de intervencion con seguimiento a los seis meses. Resultados: se evidencio una disminucion del dolor en dos unidades luego de las cuatro semanas de intervencion (p EnglishIntroduction: lumbar pain is a condition catalogued as one with the higher rate of medical services consultation. In office workers there is also a high prevalence, thus is necessary to generate intervention plans since primary intervention encourage improvement in health status of this population. Objective: to determine the effects of an exercise plan on low back pain in office workers. Material and method: it was conducted an exercise plan in the office based in the strengthening of the abdominal girdle, the neck´s deep muscles and the stretching of back straight chain in 17 workers of a company located in Bogota, for four weeks, and evolution respect to low back pain was evaluated through the Roland Morris questionnaire. Tools were applied at the end of the four weeks intervention and follow-up at six months was performed. Results: a decrease in pain by two units is evident after four weeks of intervention (p

Students of single crystal X-ray diffraction are often give advice as to how best to collect their data when attempting absolute configuration determination. These ‘rules’ often have more grounding in gut-feeling than evidence. Thus, in an effort to provide advice and evidence that today’s crystallographers can pass onto to tomorrow’s young scientists, we present a systematic study of 1-deoxy- l -arabinitol, a straight chain sugar which crystalises well in the space group I 4 1 .

Glycosaminoglycans (GAGs) are anionic straight chain polysaccharides with a wide range of [...]

[EN] Linear even-carbon-number alpha-olefins (LAO) with four or more carbon atoms are important compounds of high demand in chemical industry as precursors of a wide range of value-added chemicals [1]. LAO are used as co-monomers for polyethylene production, for the production of alcohols (mainly in detergents and plasticizers) and for synthesis of polyalphaolefins (used in synthetic lubricants). Alpha-olefins (C4, C6, C8 and C10) are mainly used to produce poly(vinyl chloride) plasticizers, high-density and linear low-density polyethylene to impart the stress-crack resistance. C10–C14 alpha-olefins can be used to synthesize linear alkylbenzene sulfonates (synthetic detergents). A conventional route to produce alpha-olefins is oligomerization of ethylene. The process provides production of high quality alpha-olefins but is very costly. If not oligomerization, LAO can be produced by thermal cracking of waxy paraffins but the product is not pure and contains numerous internal olefins, dienes and paraffin impurities. The process is conducted in the vapor phase at relatively low cracking temperatures and needs rapid quenching to prevent side reactions such as isomerization or cyclization. In our previous work [2], we showed that the selectivity to alpha-olefins can be increased considerably via catalytic cracking of n-alkanes under selective MW heating of catalysts. In the present work, the general regularities of MW cracking of n-alkanes are presented. Porous ceramic matrix Al2O3/Al composites (ceramometals) and various carbon materials (CM) having high dielectric losses were studied as supports of the catalysts. MW cracking was conducted with n-C16H34 and n-C28H58. The influence particle size and surface morphology of ceramometals and CM on the structural and group composition of the products was studied. It was established that LAO (C2-C23) and n-alkanes (C2-C26) were the main cracking products under selective MW heating of the used supports. The quantitative analysis of the products demonstrated that the liquid-phase process is more selective to alpha-olefins at the MW catalytic cracking than at the convectional thermal cracking. Silica modification of the surface of CM was shown to suppress spark discharge (usually observed at MW heating of CM); hence, the thermal cleavage of C-C bonds on the CM surface but not in the plasma discharge contributes the most to the formation of radicals. It was shown that the selectivity to liquid alpha-olefin could be more than 85 % under MW heating of cermets in region of the E - field node and decrease considerably in the region of H - field node., The research was supported by RSF (project No. 17-73-30032).

The EFSA Panel on Food Additives and Flavourings (FAF) was requested to evaluate 54 flavouring substances attributed to the Flavouring Group Evaluation 05 (FGE.05), using the Procedure as referred to in the Commission Regulation (EC) No 1565/2000. This Revision 3 includes 17 additional substances which have been cleared with respect to genotoxicity in FGE.200Rev1 ([FL‐no: 02.192, 02.231, 05.072, 05.144, 05.184, 05.189, 05.190, 05.191, 05.195, 09.247, 09.400, 09.866, 09.948]) and in FGE.203Rev2 ([FL‐no: 05.081, 05.186, 05.194, 05.196]). The substances were evaluated through a stepwise approach that integrates information on the structure–activity relationships, intake from current uses, toxicological threshold of concern (TTC), and available data on metabolism and toxicity. The Panel concluded that none of the 54 substances gives rise to safety concern at their levels of dietary intake, estimated on the basis of the ‘Maximised Survey‐derived Daily Intake’ (MSDI) approach. Besides the safety assessment of the flavouring substances, the specifications for the materials of commerce have also been considered and found adequate, except for 10 substances ([FL‐no: 08.072, 08.083, 08.101, 08.119, 08.120, 09.181, 09.329, 09.335, 09.379 and 09.637]) for which quantitative figures on the composition of stereoisomeric mixtures are missing and for [FL‐no: 09.578] complete specifications should be provided. Normal and maximum use levels were not available for [FL‐no: 08.072, 08.083, 08.101, 08.119, 08.120, 09.287, 09.326 and 09.578]. Except for flavouring substances [FL‐no: 05.072, 05.081, 05.186, 05.194, 05.196, 09.934 and 09.942], more reliable intake data should be requested for all the 46 flavouring substances, for which use levels were submitted, as their modified Theoretical Added Maximum Daily Intake (mTAMDI) exposure estimates are above the threshold of concern for structural classes I and II. This would include more reliable intake data and then, if required, additional toxicological data.

Density of binary mixtures of ethyl acetoacetate (EAA) with straight chain aliphatic ketones butan-2-one, pentan-2-one, hexan-2-one, heptan-2-one, octan-2-one and nonan-2-one were measured at varying compositions of the ethyl acetoacetate at 298.15 K. The derived properties such as excess molar volumes, V m E , of the binary mixtures were calculated from the experimental density data of the mixtures. The calculated excess molar volumes were fitted into the Redlich-Kister polynomial to obtain the fitting parameters and standard deviations. The excess molar volumes of the binary mixtures investigated were negative over the entire range of composition. The negative values were attributed to dipole–dipole interactions between the unlike molecules of mixtures than those between the like molecules of the pure solvents. The observed negative values of the excess molar volumes for the studied binary mixtures were discussed in terms of intermolecular interactions which were present in the mixtures.

The straight-chain alkane-assisted synthesis of hierarchical mesoporous silica materials (MSM) results in variable mesostructures and morphologies due to remarkably different self-assembly routes of template agent from those without the assistance of straight-chain alkanes. The textural properties, particularly pore size, channel structure, morphology, and hierarchical structure of those MSM make them demonstrate peculiar effects in the immobilization of homogeneous catalysts.

The Panel on Food Additives and Flavourings of the European Food Safety Authority was requested to evaluate the genotoxic potential of 74 flavouring substances from subgroup 1.1.1 of FGE.19 in the Flavouring Group Evaluation 200 Revision 1 (FGE.200 Rev1). In FGE.200, genotoxicity studies were provided for one representative substance, namely hex‐2(trans)‐enal [FL‐no: 05.073], and for other two substances in the same subgroup, namely 2‐dodecenal [FL‐no: 05.037] and 2‐nonenal [FL‐no: 05.171]. The Panel concluded that the concern still remains with respect to genotoxicity for the substances of this subgroup and requested an in vivo Comet assay performed in duodenum and liver for hex‐2(trans)‐enal [FL‐no: 05.073]. For the two other representative substances of subgroup 1.1.1 (nona‐2(trans),6(cis)‐dienal [FL‐no: 05.058] and oct‐2‐enal [FL‐no: 05.060]), the Panel requested a combined in vivo Comet assay and micronucleus assay. These data have been provided and are evaluated in the present opinion FGE.200 Rev1. Industry submitted genotoxicity studies on trans‐2‐octenal [FL‐no: 05.190], instead of oct‐2‐enal [FL‐no: 05.060]. Based on the available data, the Panel concluded that the concern for genotoxicity can be ruled out for hex‐2(trans)‐enal [FL‐no: 05.073], trans‐2‐octenal [FL‐no: 05.190] and nona‐2(trans),6(cis)‐dienal [FL‐no: 05.058], therefore all the 74 substances [FL‐no: 02.020, 02.049, 02.050, 02.090, 02.112, 02.137, 02.156, 02.192, 02.210, 02.231, 05.037, 05.058, 05.060, 05.070, 05.072, 05.073, 05.076, 05.078, 05.102, 05.109, 05.111, 05.114, 05.120, 05.144, 05.150, 05.171, 05.172, 05.179, 05.184, 05.189, 05.190, 05.191, 05.195, 06.025, 06.031, 06.072, 09.054, 09.097, 09.109, 09.119, 09.146, 09.233, 09.244, 09.247, 09.276, 09.277, 09.303, 09.312, 09.385, 09.394, 09.395, 09.396, 09.397, 09.398, 09.399, 09.400, 09.410, 09.411, 09.469, 09.482, 09.489, 09.492, 09.493, 09.498, 09.678, 09.701, 09.719, 09.741, 09.790, 09.841, 09.866, 09.947, 09.948, 13.004] can be evaluated through the Procedure for flavouring substances.

The Panel on Food Additives and Flavourings of the European Food Safety Authority was requested to evaluate the genotoxic potential of 74 flavouring substances from subgroup 1.1.1 of FGE.19 in the Flavouring Group Evaluation 200 Revision 1 (FGE.200 Rev1). In FGE.200, genotoxicity studies were provided for one representative substance, namely hex-2(trans)-enal [FL-no: 05.073], and for other two substances in the same subgroup, namely 2-dodecenal [FL-no: 05.037] and 2-nonenal [FL-no: 05.171]. The Panel concluded that the concern still remains with respect to genotoxicity for the substances of this subgroup and requested an in vivo Comet assay performed in duodenum and liver for hex-2(trans)-enal [FL-no: 05.073]. For the two other representative substances of subgroup 1.1.1 (nona-2(trans),6(cis)- dienal [FL-no: 05.058] and oct-2-enal [FL-no: 05.060]), the Panel requested a combined in vivo Comet assay and micronucleus assay. These data have been provided and are evaluated in the present opinion FGE.200 Rev1. Industry submitted genotoxicity studies on trans-2-octenal [FL-no: 05.190], instead of oct-2-enal [FL-no: 05.060]. Based on the available data, the Panel concluded that the concern for genotoxicity can be ruled out for hex-2(trans)-enal [FL-no: 05.073], trans-2-octenal [FL-no: 05.190] and nona-2(trans),6(cis)-dienal [FL-no: 05.058], therefore all the 74 substances [FL-no: 02.020, 02.049, 02.050, 02.090, 02.112, 02.137, 02.156, 02.192, 02.210, 02.231, 05.037, 05.058, 05.060, 05.070, 05.072, 05.073, 05.076, 05.078, 05.102, 05.109, 05.111, 05.114, 05.120, 05.144, 05.150, 05.171, 05.172, 05.179, 05.184, 05.189, 05.190, 05.191, 05.195, 06.025, 06.031, 06.072, 09.054, 09.097, 09.109, 09.119, 09.146, 09.233, 09.244, 09.247, 09.276, 09.277, 09.303, 09.312, 09.385, 09.394, 09.395, 09.396, 09.397, 09.398, 09.399, 09.400, 09.410, 09.411, 09.469, 09.482, 09.489, 09.492, 09.493, 09.498, 09.678, 09.701, 09.719, 09.741, 09.790, 09.841, 09.866, 09.947, 09.948, 13.004] can be evaluated through the Procedure for flavouring substances.

The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate the genotoxic potential of flavouring substances from subgroup 1.1.4 of FGE.19 in the Flavouring Group Evaluation 203 Revision 2 (FGE.203Rev2). In FGE. 203 Revision 1, the Panel concluded that the genotoxic potential could not be ruled out for the flavouring substances in this FGE. The Flavour Industry provided additional genotoxicity studies for the representative substances of FGE.19 subgroup 1.1.4, namely deca-2(trans),4(trans)-dienal [FL-no: 05.140] and hexa-2(trans),4(trans)-dienal [FL-no: 05.057]. In addition, new studies on hepta2,4-dienal [FL-no: 05.084], 2,4-octadienal [FL-no: 05.186] and tr-2,tr-4-nonadienal [FL-no: 05.194] were provided that are evaluated in the present revision of FGE.203, i.e. FGE.203Rev2. Hepta2,4-dienal [FL-no: 05.084], 2,4-octadienal [FL-no: 05.186] and tr-2,tr-4-nonadienal [FL-no: 05.194] did not induce gene mutations in bacteria. Hexa-2(trans),4(trans)-dienal [FL-no: 05.057] did not induce gene mutations in vitro in mammalian cells. Hexa-2(trans),4(trans)-dienal [FL-no: 05.057] was also tested in an in vivo gene mutation assay giving negative results. Both hexa-2(trans),4(trans)-dienal [FL-no: 05.057] and deca-2(trans),4(trans)-dienal [FL-no: 05.140] were tested in vivo for the induction of micronuclei in rats bone marrow and peripheral reticulocytes after oral or intraperitoneal administration. None of the two substances induced increased frequencies of micronuclei. The Panel concluded that the concern for genotoxicity can be ruled out for the representative substances hexa-2(trans),4(trans)-dienal [FL-no: 05.057] and deca-2(trans),4(trans)-dienal [FL-no: 05.140] and therefore also for the other substances in this group [FL-no: 02.139, 02.153, 02.162, 02.188, 05.064, 05.071, 05.081, 05.084, 05.101, 05.108, 05.125, 05.127, 05.141, 05.173, 05.186, 05.194, 05.196, 09.573]. These 20 substances can be evaluated using the Procedure for the evaluation of flavouring substances.

International audience; The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate the genotoxic potential of flavouring substances from subgroup 1.1.4 of FGE.19 in the Flavouring Group Evaluation 203 Revision 2 (FGE.203Rev2). In FGE. 203 Revision 1, the Panel concluded that the genotoxic potential could not be ruled out for the flavouring substances in this FGE. The Flavour Industry provided additional genotoxicity studies for the representative substances of FGE.19 subgroup 1.1.4, namely deca-2(trans),4(trans)-dienal [FL-no: 05.140] and hexa-2(trans),4(trans)-dienal [FL-no: 05.057]. In addition, new studies on hepta-2,4-dienal [FL-no: 05.084], 2,4-octadienal [FL-no: 05.186] and tr-2,tr-4-nonadienal [FL-no: 05.194] were provided that are evaluated in the present revision of FGE.203, i.e. FGE.203Rev2. Hepta-2,4-dienal [FL-no: 05.084], 2,4-octadienal [FL-no: 05.186] and tr-2,tr-4-nonadienal [FL-no: 05.194] did not induce gene mutations in bacteria. Hexa-2(trans),4(trans)-dienal [FL-no: 05.057] did not induce gene mutations in vitro in mammalian cells. Flexa-2(trans),4(trans)-dienal [FL-no: 05.057] was also tested in an in vivo gene mutation assay giving negative results. Both hexa-2(trans),4(trans)-dienal [FL-no: 05.057] and deca-2(trans),4(trans)-dienal [FL-no: 05.140] were tested in vivo for the induction of micronuclei in rats bone marrow and peripheral reticulocytes after oral or intraperitoneal administration. None of the two substances induced increased frequencies of micronuclei. The Panel concluded that the concern for genotoxicity can be ruled out for the representative substances hexa-2(trans),4(trans)-dienal [FL-no: 05.057] and deca-2(trans),4(trans)-dienal [FL-no: 05.140] and therefore also for the other substances in this group [FL-no: 02.139, 02.153, 02.162, 02.188, 05.064, 05.071, 05.081, 05.084, 05.101, 05.108, 05.125, 05.127, 05.141, 05.173, 05.186, 05.194, 05.196, 09.573]. These 20 substances can be evaluated using the Procedure for the evaluation of flavouring substances.

Characterizing the mechanisms by which natural microorganisms in soil decompose gasoline hydrocarbons is of fundamental importance for a better understanding of natural attenuation and/or for predicting contaminant transport and fate in soils. To examine whether and how gasoline hydrocarbons can be decomposed under general environmental conditions, the decomposition of 10 major components generally contained in commercially available gasoline was analyzed in three arbitrarily selected Japanese soil samples. Gasoline hydrocarbons, especially aromatic hydrocarbons, are easily adsorbed by the tested Japanese soils, with straight chain hydrocarbons decomposing faster than branched hydrocarbons. Saturated monocyclic hydrocarbons were less easily decomposed than unsaturated monocyclic hydrocarbons. Enhancement of microbial decomposition of gasoline hydrocarbons requires a continuous supply of oxygen together with nutrients for the microorganisms.

With the fast development of nanotechnology, accurate measurement and classification of nanoparticles are in great need. Nanoparticles frequently appear in non-spherical forms such as long aspect ratio nanofibers, nanotubes, and irregular nano-agglomerates. While the well-developed classical studies were mainly in continuum regime with spherical particles, dynamics of the non-spherical nanoparticles is not fully understood. In this study, orientation-averaged mobility of nanofiber and nanorod (with no preferred alignment) is examined by the methods of Brownian diffusion theory, a combination of collision limited reaction rate theory and the bipolar diffusion charging analysis. Comparisons to empirical predictions from the experimental measurements are also made. The study leads to the discovery of a surface-dominated mobility for high aspect ratio nanoparticles with characteristic Knudsen number greater than 5. In view of the extreme relative length scales between particle size and the gas mean free path, particles of all morphologies can be viewed as point collisions; therefore, the equivalent surface mobility diameter is reasonably justified. This finding has been verified in the current study with high aspect ratio particles. For non-spherical particles of more general forms, further investigation is needed. As expected, accuracy of this approximation reduces as the characteristic Knudsen number decreases. When Kn(dL) < 0.1, the study shows that particle morphology starts to play an important role. A review of particle mobility for all Knudsen number flows is also provided. © 2017 American Association for Aerosol Research

Comparison theorems on resistance distances and Kirchhoff indices of the so-calledS- &T-isomer graphs are established. Then these results are applied to compare Kirchhoff indices of hexagonal chains, showing that the straight chain is the unique chain with maximum Kirchhoff index, whereas the minimum Kirchhoff index is achieved only when the hexagonal chain is an ''all-kink'' chain.

This article describes the methods for collecting automated solutions in intellectual systems. This article features conclusive methods based on the forward and reverse chains, the difference between the method of straight chain and the method of the inverse chain. This article describes methods of finding solutions in the state space, the difference between in-depth and breadth-first research. A backtracking method is described. The reduction method is revealed. The article shows the limits of applicability of methods and provides a comparison of described methods with the method of precedents.

How to overcome the friction between the micro components has become a key point of the successful operation of the micro/nano-electric mechanical systems. The understanding of the friction mechanism of the alkane liquid film confined between two substrates is important when the friction law on a macro/nano scale is not applicable. In this work, the molecular dynamics simulations are used to study the effect of the chain length on the friction properties of the liquid films that are confined between two golden substrates. There are seven pure alkane liquid films that are composed of one molecule CnH2n + 2(n = 6, 8, 10, 12, 14, 16, 18), and six mixed alkane liquid films that are composed of two molecules C6H14/CnH2n + 2(n = 8, 10, 12, 14, 16, 18) with a ratio of 1∶1. The results show that the friction force and the coefficient of friction of pure alkane liquid films both increase as the chain length increases when the carbon atom number is less than 12, whereas the friction property keeps stable when the carbon atom number of the alkane molecule is greater than 10 and the pure hexadecane liquid film has the largest friction force. In the mixed films, the addition of short chain alkane molecules can strengthen the friction, and the hexane/dodecane mixed film has the maximum friction force. The short chain molecule dilutes the C8H18 film and C10H22 film which cause the friction force to decrease. During the sliding progress, the formation of solid-like high density-packet layers is the main reason for the friction reduction. When no solid-like layer or just one solid-like layer is formed at the interface of golden base, the liquid alkane film is liquid-like and its viscosity becomes much larger than that in the normal state, which leads to high friction force. The short chain molecules reduce the density of the solid-like layers, which causes the film to transform from solid-like state to liquid state, thus resulting in the increase of friction. The friction property mainly depends on the layered structure, and the interaction between the golden surface and liquid film contributes to the friction. This study helps to understand the friction mechanism of ultra-thin liquid films.

The critical pressures pc and the critical temperatures Tc of diols with straight alkylchains HO(CH2)nOH and n = 3, 4, 5, 6, 8, 9, 10, 12 have been measured. All the alkanediols studied decompose at near-critical temperatures. A pulse-heating method which allows measuring the critical properties of thermally unstable compounds has been used. The times of heating from the beginning of a pulse to the moment of reaching the critical temperature were from (0.03 to 0.46) ms. The short residence times provided little degradation of the substances in the course of the experiments. The uncertainties of the measurement of the critical properties of alkanediols are 0.04 pc and 0.015 Tc, where Tc is the absolute temperature. The critical properties obtained have been compared with the values measured earlier by various techniques. The experimental critical constants of alkanediols have also been compared with those calculated using the group-contribution methods of Lydersen, Wilson and Jasperson, and Marrero and Gani.

Following a request from the European Commission, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of 24 compounds belonging to chemical group 4 (non‐conjugated and accumulated unsaturated straight‐chain and branched‐chain, aliphatic primary alcohols, aldehydes, acids, acetals and esters). This opinion concerns 23 compounds from this group. They are currently authorised as flavours in food. The FEEDAP Panel established the following conclusions: hex‐3(cis)‐en‐1‐ol [02.056], (Z)‐non‐6‐en‐1‐ol [02.093], oct‐3‐en‐1‐ol [02.094], non‐6(cis)‐enal [05.059], hex‐3(cis)‐enal [05.075], (Z)‐hept‐4‐enal [05.085], hex‐3(cis)‐enyl acetate [09.197], hex‐3(cis)‐enyl formate [09.240], hex‐3‐enyl butyrate [09.270], hex‐3‐enyl hexanoate [09.271] and hex‐3(cis)‐enyl isobutyrate [09.563] are safe at the proposed maximum use level of 5 mg/kg complete feed for all target species; citronellol [02.011], (‐)‐3,7‐dimethyl‐6‐octen‐1‐ol [02.229], citronellal [05.021], 2,6‐dimethylhept‐5‐enal [05.074], citronellic acid [08.036], citronellyl acetate [09.012], citronellyl butyrate [09.049], citronellyl formate [09.078] and citronellyl propionate [09.129] are safe at the maximum use level of 5 mg/kg for all species, except cats for which the proposed normal use level of 1 mg/kg is considered safe; undec‐10‐enal [05.035], 1‐ethoxy‐1‐(3‐hexenyloxy)ethane [06.081] and hex‐3‐enyl isovalerate [09.505] are safe at the normal use levels of 1 mg/kg for all species. No safety concern would arise for the consumer from the use of these compounds up to the highest safe level in feeds. Hazards for skin and eye contact, and respiratory exposure are recognised for the majority of the compounds under application. Most are classified as irritating to the respiratory system. The use of the majority of the compounds in animal feed at the maximum safe level is considered safe for the environment. As all the compounds under assessment are used in food as flavourings, and their function in feed is essentially the same as in food, no further demonstration of efficacy is necessary.

Experimental measurements of turbulent and laminar burning velocities have been made for premixed hydrocarbon–air flames of straight chain molecules of increasing carbon number (from n-pentane to n-octane). Measurements were performed at 0.5 MPa, 360 K and rms turbulent velocities of 2 and 6 m/s, for a range of equivalence ratios. The laminar burning velocities were used to interpret the turbulent data, but were also found to be broadly in line with those of previous workers. At lean conditions the turbulent burning velocity was measured to be similar between the four alkanes studied. However, at rich conditions there were notable differences between the turbulent burn rates of the fuels. The equivalence ratio of the mixtures at which the maximum burning velocities occurred in the turbulent flames was richer than that under laminar conditions. The equivalence ratio of the peak turbulent burning velocity was found to be a function of the carbon number of the fuel and the turbulent intensity and became gradually fuel rich with increases in each of these values.

Alkyl and multifunctional organic nitrates, molecules of the chemical form RONO2, are products of chain terminating reactions in the tropospheric HOx and NOx catalytic cycles and thereby impact ozone formation locally. Many of the molecules in the class have lifetimes that are long enough that they can be transported over large distances. If the RONO2 then decompose to deliver NOx to remote regions they affect ozone production rates in locations distant from the original NOx source. While measurements of total RONO2 (ΣANs) and small straight chain alkyl nitrates are routine, measurements of the specific multifunctional RONO2 molecules that are believed to dominate the total have rarely been reported and never reported in coincidence with ambient ΣANs measurements. Here we describe observations obtained during the BEARPEX 2009 experiment including ΣANs and a suite of multifunctional nitrates including isoprene derived hydroxynitrates, oxidation products of those nitrates, 2-methyl-3-buten-2-ol (MBO) derived hydroxynitrates, and monoterpene nitrates. At the BEARPEX field site, the sum of the individual biogenically derived nitrates account for two-thirds of the ΣANs, confirming predictions of the importance of biogenic nitrates to the NOy budget. Isoprene derived nitrates, transported to the site, are a much larger fraction of the ΣANs at the site than the nitrates derived from the locally emitted MBO. Evidence for additional nitrates, possibly from nocturnal chemistry of isoprene and α-pinene, is presented.

Knowledge about therapy with insects in Mongolian traditional medicine is less studied even they have been used broadly since ancient time. Several orthodox practitioners have surveyed the therapeutic potentials of defensive agents in Blaps femoralis known as “stink beetle” in the past. We present results about content of defensive secretion and surface lipids, both a biologically active principle in insect, used in traditional Mongolian medicine. A combination of gas chromatography and mass spectroscopy was used for the identification of several p-benzoquinone derivatives accompanied by straight chain hydrocarbons and fatty acids. None of these compounds has been reported previously from this species. An IR imaging of insect cuticle surface shows the possibility for the analytical characterization of fatty acids in tissue at high lateral resolution of few microns.

Treatment of [Fc-1-R 1 -1′-R 2 ] (R 1 = H, R 2 = CH(O); R 1 = H, R 2 = CMe(O); R 1 = R 2 = CMe(O)) with LiC CCH 2 OLi (prepared in situ from HC CCH 2 OH and n -BuLi) affords the ferrocenyl-substituted but-2-yne-1,4-diol compounds of general formula [Fc-1-R 1 -1′-{CR(OH)C CCH 2 OH}] (R 1 = R = H ( 1a ); R 1 = H, R = Me ( 1b ); R 1 = CMe(O), R = Me ( 1c )) in low to high yields, respectively (where Fc = Fe(η 5 -C 5 H 4 ) 2 ). In the case of the reactions of [Fc-1-R 1 -1′-R 2 ] (R 1 = H, R 2 = CH(O); R 1 = R 2 = CMe(O)), the by-products [Fc-1-R 1 -1′-{CR(OH)(CH 2 ) 3 CH 3 }] (R 1 = R = H ( 2a ); R 1 = CMe(O), R = Me ( 2c )) along with minor quantities of [Fc-1,1′-{CMe(OH)(CH 2 ) 3 CH 3 } 2 ] ( 3 ) are also isolated; a hydrazide derivative of dehydrated 2c , [1-(CMe CHCH 2 CH 2 CH 3 )–1′-(CMe NNH-2,4-(NO 2 ) 2 C 6 H 3 )] ( 2c ′), has been crystallographically characterised. Interaction of 1 with Co 2 (CO) 8 smoothly generates the alkyne-bridged complexes [Fc-1-R 1 -1′-{Co 2 (CO) 6 -μ-η 2 -CR(OH)C CCH 2 OH}] (R 1 = R = H ( 4a ); R 1 = H, R = Me( 4b ); R 1 = CMe(O), R = Me ( 4c )) in good yield. Reaction of 4a with PhSH, in the presence of catalytic quantities of HBF 4 · OEt 2 , gives the mono- [Fc-1-H-1′-{Co 2 (CO) 6 -μ-η 2 –CH(SPh)C CCH 2 OH}] ( 5 ) and bis-substituted [Fc-1-H-1′-{Co 2 (CO) 6 -μ-η 2 -CH(SPh)C CCH 2 SPh}] ( 6 ) straight chain species, while with HS(CH 2 ) n SH ( n = 2,3) the eight- and nine-membered dithiomacrocylic complexes [Fc-1-H-1′-{ cyclo -Co 2 (CO) 6 -μ-η 2 -CH(S(CH 2 ) n –)C CCH 2 S–}] [ n = 2 ( 7a ), n = 3 ( 7b )] are afforded. By contrast, during attempted macrocyclic formation using 4b and HSCH 2 CH 2 OCH 2 CH 2 SH dehydration occurs to give [Fc-1-H-1′-{Co 2 (CO) 6 -μ-η 2 -C( CH 2 )C CCH 2 OH}] ( 8 ). Single crystal X-ray diffraction studies have been reported on 2c ′, 4b , 4c , 7b and 8 .

Ultraviolet irradiation (UV-C) is proven to be effective to inactivate microorganisms. The present study investigates the effect of sublethal UV-C rays on the membrane fatty acid profile of four Staphylococcus aureus strains isolated from air, patient, food and animal. Our results show that S. aureus isolated from patients and air are the most sensitive to UV-C rays and that their inactivation achieves a greater than 2-log reduction after a UV-C exposure of 210 mJ cm−2. However, the strain isolated from food is the most resistant one. The fatty acid analysis indicates that this strain (food) reveals a decrease of branched chain fatty acids (BCFA iso and anteiso) and an increase of straight chain saturated fatty acids (SCFA).

Chlorinated paraffins (also called polychlorinated n-alkanes — PCAs) are a class of industrial chemicals comprising chlorinated straight chain hydrocarbons. They have a wide range of applications and are now found in a range of environmental compartments. We analysed a total of 25 human milk-fat samples, donated by 18 individuals from the urban London and more rural Lancaster areas in the UK, for short chain PCAs (C10–C13 sPCAs) and medium chain PCAs (C14–C17 mPCAs), using gas chromatography–ECNI high-resolution mass spectrometry. Our study confirms that trace quantities of PCAs can reach human milk-fat. sPCAs were detected in all but four samples, while mPCAs were detected in all samples. The median sPCA concentration was 180 ng/g fat (range of 49 to 820 ng/g fat — detected values only) and the median mPCA concentration was 21 ng/g fat (range of 6.2 to 320 ng/g fat). No differences were noted in ranges of observed values for either sPCAs or mPCAs between samples from London and Lancaster. Most samples also exhibited similar patterns of sPCAs and mPCAs. One sample exhibited a different pattern for sPCAs and mPCAs, an observation that may be related to differences in exposure or biological factors for this individual. Keywords: Breast-milk, Organochlorine, SCCP, MCCP

The interfacial tension (IFT) of 1 M solutions of N,N-dialkyl amide in n-dodecane against water and nitric acid has been measured at 303K. Ten amides, namely, dibutyl hexanamide (DBHA), diisobutyl hexanamide (DiBHA), dibutyl octanamide (DBOA), dihexyl hexanamide (DHHA), dibutyl dodecanamide (DBDA), di n-octyl butanamide (DOBA), diisooctyl butanamide (DiOBA), di n-octyl isobutanamide (DOiBA), di n-hexyl octanamide (DHOA), and di n-octyl hexanamide (DOHA) were synthesized and used. The effect of concentration of DOHA on IFT against 3 M nitric acid was also studied. It was observed that the introduction of branching in an amide on either the acyl or the nitrogen side increases the IFT over its straight chain analogue, as in the case of DiOBA, DOiBA, and DiBHA. Increasing the carbon chain length on the acyl side, keeping the total carbon number constant, was found to increase the IFT considerably. Increasing the concentration of the amide resulted in a decrease in the IFT values, due to the lowering of the concentration of hydrophobic diluent. An increase in the uranium loading of the organic phase in the case of 1 M DOHA, was found to increase the IFT.

Biolubricants from Castor oil were produced enzymatically by transesterification with higher alcohols using a lipase mixture of immobilized Mucor miehei (RMIM) and immobilized Candida antarctica lipase B (Novozym 435) under low water conditions. The conversions were in the range of 80–95% under the optimized conditions.