The “Dipylon” vases and their graves: the end of exclusivity in Early Iron age Athens:

Choosing the “Dipylon vases" as a point of departure, the present article explores the funerary practices in Athens and Attica during the middle of the eighth century and the Late Geometric I period closely associated with the date during the ninth and the second half of the eighth centuries. Rather than the funerary iconography of these vases, the context is set at the heart of the discussion. The interest is placed on the burials marked in this special way and, more importantly, on the identity of their occupants who deserved this special type of memorization, accomplished through these clay mnemata.Choosing the “Dipylon vases" as a point of departure, the present article explores the funerary practices in Athens and Attica during the middle of the eighth century and the Late Geometric I period closely associated with the date during the ninth and the second half of the eighth centuries. Rather than the funerary iconography of these vases, the context is set at the heart of the discussion. The interest is placed on the burials marked in this special way and, more importantly, on the identity of their occupants who deserved this special type of memorization, accomplished through these clay mnemata

Sample preparation techniques for extraction of vitamin D metabolites from non-conventional biological sample matrices prior to LC–MS/MS analysis

The determination of vitamin D metabolites as status marker or for diagnostic purposes is almost entirely conducted from blood serum or plasma. Other biological matrices, however, have also interested researchers, for two main reasons: (1) alternative matrices may allow non-invasive sampling, permit easier sample transfer and require less demanding storage conditions; and (2) the levels of vitamin D metabolites in other body compartments may further aid the understanding of vitamin D metabolism and function. Thus, the development of reliable and efficient sample preparation protocols for sample matrices other than serum/plasma, which will remove potential interferences and selectively extract the targeted metabolites, is of great importance. This review summarizes sample preparation methods for measurement of vitamin D metabolites using liquid chromatography-(tandem)mass spectrometry in more than ten different human tissues, including hair, saliva, adipose tissue, brain and others.Peer Reviewe

Comparing derivatization reagents for quantitative LC–MS/MS analysis of a variety of vitamin D metabolites

The present study systematically compares the sensitivity and selectivity of the analysis of multiple vitamin D metabolites after chemical derivatization using different reagents for liquid chromatography-tandem mass spectrometry (LC–MS/MS). Generally, chemical derivatization is applied to vitamin D metabolites to increase the ionization efficiency, which is particularly important for very low abundant metabolites. Derivatization can also improve the selectivity of the LC separation. A wide variety of derivatization reagents has been reported in recent years, but information on their relative performance and applicability to different vitamin D metabolites is, unfortunately, not available in the literature. To fill this gap, we investigated vitamin D3, 3β-25-hydroxyvitamin D3 (3β-25(OH)D3), 3α-25-hydroxyvitamin D3 (3α-25(OH)D3), 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), and 24,25-dihydroxyvitamin D3 (24,25(OH)2D3) and compared response factors and selectivity after derivatizing with several important reagents, including four dienophile reagents (4-phenyl-1,2,4-triazoline-3,5-dione (PTAD), 4-[2-(6,7-dimethoxy-4-methyl-3-oxo-3,4-dihydroquinoxalinyl)ethyl]-1,2,4-triazoline-3,5-dione (DMEQ-TAD), Amplifex, 2-nitrosopyridine (PyrNO)) as well as two reagents targeting hydroxyl groups: isonicotinoyl chloride (INC) and 2-fluoro-1-methylpyridinium-p-toluenesulfonate (FMP-TS). In addition, a combination of dienophiles and hydroxyl group reagents was examined. For LC separations, reversed-phase C-18 and mixed-mode pentafluorophenyl HPLC columns using different compositions of the mobile phase were compared. With respect to detection sensitivity, the optimum derivatization reagent for the profiling of multiple metabolites was Amplifex. Nevertheless, FMP-TS, INC, PTAD, or PTAD combined with an acetylation reaction showed very good performance for selected metabolites. These reagent combinations provided signal enhancements on the order of 3- to 295-fold depending on the compound. Chromatographic separation of the dihydroxylated vitamin D3 species was readily achieved using any of the derivatization reactions, while for 25(OH)D3 epimers, only PyrNO, FMP, INC, and PTAD combined with acetylation enabled complete separation. In conclusion, we believe this study can serve as a useful reference for vitamin D laboratories, to help analytical and clinical scientists decide which derivatization reagent to choose for their application.Peer Reviewe

Analysis of vitamin D metabolic markers by mass spectrometry: Recent progress regarding the “gold standard” method and integration into clinical practice

Liquid chromatography/tandem mass spectrometry is firmly established today as the gold standard technique for analysis of vitamin D, both for vitamin D status assessments as well as for measuring complex and intricate vitamin D metabolic fingerprints. While the actual mass spectrometry technology has seen only incremental performance increases in recent years, there have been major, very impactful changes in the front- and back-end of MS-based vitamin D assays; for example, the extension to new types of biological sample matrices analyzed for an increasing number of different vitamin D metabolites, novel sample preparation techniques, new powerful chemical derivatization reagents, as well the continued integration of high resolution mass spectrometers into clinical laboratories, replacing established triple-quadrupole instruments. At the same time, the sustainability of mass spectrometry operation in the vitamin D field is now firmly established through proven analytical harmonization and standardization programs. The present review summarizes the most important of these recent developments.Peer Reviewe

Le traitement funéraire des immatures dans la nécropole archaïque de Vari

Based on information extracted from the diary of excavations conducted in the late 1930s, the present article discusses for the first time the child-burials of the archaic north necropolis of Vari, dating from the late 7th to 6th century BC. The spatial organization of the cemetery shows that children are buried together with adults and not separately in necropoleis reserved for pre-adults, as is the case in contemporary Attika. More importantly, a number of child-burials attracted special attention, and were venerated like those of adults, indicating that despite their age, young members of the local elite were treated as deserving of respect as heirs of their high status

Prevalence of Oxacillin-resistant Staphylococcus Strains in Clinical Specimens from Intensive Care Unit Patients

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