The Role of Biological Sex in Pre-Clinical (Mouse) mRNA Vaccine Studies.

In this study, we consider the influence of biological sex-specific immune responses on the assessment of mRNA vaccines in pre-clinical murine studies. Recognising the established disparities in immune function attributed to genetic and hormonal differences between individuals of different biological sexes, we compared the mRNA expression and immune responses in mice of both biological sexes after intramuscular injection with mRNA incorporated within lipid nanoparticles. Regarding mRNA expression, no significant difference in protein (luciferase) expression at the injection site was observed between female and male mice following intramuscular administration; however, we found that female BALB/c mice exhibit significantly greater total IgG responses across the concentration range of mRNA lipid nanoparticles (LNPs) in comparison to their male counterparts. This study not only contributes to the scientific understanding of mRNA vaccine evaluation but also emphasizes the importance of considering biological sex in vaccine study designs during pre-clinical evaluation in murine studies.

Molecular genetics and phylogeny of Ephippigera species group of genus Saga Charpentier, 1825 (Orthoptera: Ensifera: Saginae) in Anatolia.

The genus Saga, one of the largest predatory bush crickets and insects in the Palearctic region, is represented by nine species in Anatolia. According to the morphological and bioacoustics evaluations of the Ephippigera species group belonging to the Saga genus, it consists of three species: S. ephippigera, S. syriaca, and S. hakkarica. To the present, however, there is no molecular genetic research on this species group. In our study, by using the 16S rDNA gene sequences, the molecular phylogeny of this species group is revealed and the morphological species hypotheses has been tested. In the study, specimens belonging to S. ephippigera, S. syriaca, and S. hakkarica were collected between the years of 2018 and 2020 with sweep netting; the DNA isolation, polymerase chain reactions, purifications and double-stranded sequencing were performed to obtain 16S rDNA gene sequences. Sequences were evaluated phylogenetically by performing alignment, phylogenetic analysis (Maximum Likelihood and Bayesian Inference), and dating of cladogenetic events, respectively. The monophyletic and species hypotheses of all three species have been supported by molecular data. It has been determined that the S. ephippigera species is the origin lineages of the Ephippigera species group which diverged approximately 0.4 million years ago; it has been also revealed that the climatic changes in the glacial and inter-glacial periods in the Middle Pleistocene period affected greatly the evolution of the species group.

Determination of neurotoxic agents as markers of common vetch adulteration in lentil by LC-MS/MS.

Vicia sativa (common vetch), which contains ß-cyanoalanine (BCA) and γ-glutamyl ß-cyanoalanine (γGBCA) is used for adulteration of lentil and have neuro toxic effects on people and animals. Therefore the determination of BCA and γGBCA analytes in accurate and reliable manner has high importance for human and animal health. LC-IDMS/MS method has been developed and validated for quantitative analyses of ß-cyanoalanine and 13C labeled BCA is used as an internal standard in γGBCA analysis. In order to validate the method, linearity, recovery, precision (repeatability), intermediate precision, limit of detection, and limit of quantification parameters were investigated. The correlation coefficient was found to be greater than 0.99 for both analytes. The recoveriess were determined as 95.8% for BCA and 97.4% for γGBCA. The relative expanded measurement uncertainties of ß-cyanoalanine and γ-glutamyl-ß-cyanoalanine were obtained as 4.6% and 5.8%, respectively with the coverage factor, k, is 2 and at 95% confidence level.

Potential reference measurement procedures for PBDE in surface water at levels required by the EU Water Frame Directive.

Polybrominated diphenylethers (PBDE), used as flame retardants, are named as priority substances in the Directive 2000/60/EC of the European parliament and of the council establishing a framework for Community action in the field of water policy. An annual average environmental quality standard (EQS) for inland surface waters of 0.0005 µg/L (0.0002 µg/L for other surface waters) for PBDE congeners involved in the technical penta-PBDE mixtures containing PBDE with five bromine atoms has been established. The directives focus especially on the congeners PBDE 28, 47, 99, 100, 153 and 154 contained in the penta-PBDE mixture. Up to now, no reference measurement procedures have been established reaching the limits of quantification (LOQs) and the associated uncertainties as defined in the directives with results traceable to the SI. Within a recent European project on metrology, different approaches for the traceable quantification of PBDE, based on liquid/liquid or solid phase extraction followed by the detection with gas chromatography coupled to either inductively coupled plasma mass spectrometry or triple quadrupole mass spectrometry, were investigated and the related LOQs and expanded uncertainties of the results were compared. A complete uncertainty budget for each method was estimated according to the Guide to the Expression of Uncertainty in Measurement (GUM). All presented analytical procedures can serve as reference measurement procedures regarding the LOQs and their associated expanded uncertainties for monitoring the six priority PBDEs named above. LOQs as low as 0.026 ng/kg with an associated expanded uncertainty of 0.002 ng/kg could be achieved.

Sources of polycyclic hydrocarbons and pesticides in soluble fraction of deposition samples in Kocaeli, Turkey.

A wet-dry deposition sampler was located at The Scientific and Technological Research Council of Turkey-National Metrology Institute (TUBITAK-UME) station, and a bulk deposition sampler was placed at the Kadilli village to determine the atmospheric deposition flux of polycyclic aromatic hydrocarbons (PAHs) and pesticides (organochlorine and organophosphorus) in soluble fraction of samples in Kocaeli, Turkey. The 28 samples for each wet, dry, and total deposition were collected weekly from March 2006 to March 2007. Gas chromatography-tandem mass spectrometry was used to analyze the samples which were prepared by using solid-phase extraction (SPE) method. The sum of volume weighted mean of deposition fluxes was obtained as 7.43 µg m(-2) day(-1) for wet deposition, 0.28 µg m(-2) day(-1) for dry deposition and 0.54 µg m(-2) day(-1) for bulk deposition samples for PAHs and 9.88 µg m(-2) day(-1) for wet deposition, 4.49 µg m(-2) day(-1) for dry deposition, and 3.29 µg m(-2) day(-1) for bulk deposition samples for pesticides. While benzo(a)anthracene had the highest fluxes among PAH compounds for all types of depositions, guthion and phosphamidon had the highest deposition flux compared with the other pesticides. Benzo(ghi)perylene, dibenz(a,h)anthracene, indeno(1,2,3-c,d)pyrene, benzo(a)pyrene, and acenaphthene were not detected in any of the samples. Beta-HCH, gamma-HCH, and endrin aldehyde were the only compounds among 18 organochlorine pesticides to be detected in all deposition samples. The main sources of pesticides were the high number of greenhouses around the sampling stations. However, all of the organophosphorus pesticides were detected in all deposition samples. The pollution sources were identified as coal and natural gas combustion, petrogenic sources, and traffic for TUBITAK-UME station whereas coal and natural gas combustion and traffic were the main sources for Kadilli station by considering the results of factor analysis, ratios, and wind sector analysis.

Full method validation for the determination of hexachlorobenzene and hexachlorobutadiene in fish tissue by GC-IDMS.

This paper summarizes the validation strategy and the results obtained for the simultaneous determination of hexachlorobenzene (HCB) and hexachlorobutadiene (HCBD) in fish tissue with a maximum of about 10% m/m fat content using a GC-IDMS technique. The method is applicable for the determination of HCB and HCBD at trace levels in different kinds of fish tissue samples in accordance with the requirements of the EU Directive 2008/105/EC establishing Environmental Quality Standard (EQS) levels for biota in aquatic ecosystems (10 ng/g for HCB and 55 ng/g for HCBD). The method validation aimed to assess performance parameters such as linearity, limit of detection/limit of quantification (LOD/LOQ), trueness, selectivity, intermediate precision, repeatability, stability of the extracts and robustness. The validation experiments have been performed by using uncontaminated fish tissue. Trueness was evaluated by using a certified reference material (NIST SRM 1947) (where applicable) and by the standard addition method. Very good linear signal-concentration curves were obtained for both analytes over the whole range of calibration. The repeatability and the intermediate precision of the method, expressed as relative standard deviation (RSD) and calculated at the EQS level, were estimated to be below 3% both for HCB and HCBD. The limits of quantification were 3.7 ng/g for HCB and 15.7 ng/g for HCBD in the fish. An uncertainty budget for the measurement of both HCB and HCBD in fish at about the EQS levels, applying the described method, has been established in the order of 10%. The analytical method and its performance characteristics take into account the requirements of EU Directive 2009/90/EC regarding the establishment of minimum performance criteria for the methods of analysis to be used in the water monitoring activity of the Water Framework Directive. Finally, the validated method was successfully tested on contaminated Silurus glanis from Ebro River (Spain). The method will be used in the homogeneity, stability and interlaboratory comparison studies for the characterization of a new candidate certified reference material.

An efficient GC-IDMS method for determination of PBDEs and PBB in plastic materials.

In this study, a fast, inexpensive, simple and reliable analytical method, involving pressurized solvent extraction (PSE) system and gas chromatography, coupled to an ion trap tandem mass spectrometry (GC-ITMS-MS), has been developed. It was validated for determination of 2,2',4,4'-tetrabromodiphenyl (BDE-47), 2,2',3,4,4',5',6-heptabromodiphenyl (BDE-183), 2,2',3,3',4,4',5,5',6-nonabromodiphenyl (BDE-206) and decabromodiphenyl (BDE-209) ethers and decabromobiphenyl (BB-209) in polypropylene (PP), polyethylene (PE) and acrylonitrile butadiene styrene (ABS) polymeric matrix. Certified reference materials (CRM) were used to assess the trueness of the method. Quantification of the analytes was performed by a primary method, i.e. isotope dilution mass spectrometry (IDMS). An important advantage of the method is speed. While the analysis of a single sample could take one and half hours, analyses of six samples take 5h. This is due to the automated PSE system, which allows extraction of six samples simultaneously. Automated system increases the repeatability and reduces analyst dedication and human error input. Recoveries between 79.6% and 93.7% were obtained. GC/ITMS-MS presented high selectivity by eliminating matrix effect so that the LOD values of 0.079-0.493 mg/kg in polymeric matrix were obtained. The method was applied to various selected electrical and electronic products. Sum of the mass fractions of PBDE and PBB analytes in the materials was determined to be under 1000 mg/kg, which is the limit defined by directives.

Snell's law of refraction observed in thermal frontal polymerization.

We demonstrate that Snell's law of refraction can be applied to thermal fronts propagating through a boundary between regions that support distinct frontal velocities. We use the free-radical frontal polymerization of a triacrylate with clay filler that allows for two domains containing two different concentrations of a peroxide initiator to be molded together. Because the polymerization reaction rates depend on the initiator concentration, the propagation speed is different in each domain. We study fronts propagating in two parallel strips in which the incident angle is 90 degrees. Our data fit Snell's law v(r)/v(i)=sin theta(r)/sin theta(i), where v(r) is the refracted velocity, v(i) is the incident velocity, theta(r) is the angle of refraction, and theta(i) is the incident angle. Further, we study circular fronts propagating radially from an initiation point in a high-velocity region into a low-velocity region (and vice versa). We demonstrate the close resemblance between the numerically simulated and experimentally observed thermal reaction fronts. By measuring the normal velocity and the angle of refraction of both simulated and experimental fronts, we establish that Snell's law holds for thermal frontal polymerization in our experimental system. Finally we discuss the regimes in which Snell's law may not be valid.