The enterocyte proteome of gilthead seabream (Sparus Aurata) acclimated to two salinited conditions

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Dental metric standards for sex estimation in archaeological populations from Iran

Sex estimation of skeletal remains is one of the major components of forensic identification of unknown individuals. Teeth are a potential source of information on sex and are often recovered in archaeological or forensic contexts due to their post-mortem longevity. Currently there is limited data on dental sexual dimorphism of archaeological populations from Iran. This dissertation represents the first study to provide a dental sex estimation method for Iron Age populations. The current study was conducted on the skeletal remains of 143 adults from two Iron Age populations in close temporal and geographic proximity in the Solduz Valley (West Azerbaijan Province of Iran). 2D and 3D cervical mesiodistal and buccolingual and root volume measurements of maxillary and mandibular teeth were used to investigate the degree of sexual dimorphism in permanent dentition and to assess their applicability in sex estimation. In total 1327, 457, and 480 anterior and posterior teeth were used to collect 2D cervical, 3D cervical, and root volume measurements respectively. 2D cervical measurements were taken using Hillson-Fitzgerald dental calliper and 3D measurements were collected using CT images provided by Open Research Scan Archive (ORSA) - Penn Museum. 3D models of the teeth were created using manual segmentation in the Amira 6.01 software package. Since tooth density largely differs from crown to apex, root segmentation required two threshold levels: the segmentation of the root from the jaw and the segmentation of the crown from the root. Thresholds used for root segmentation were calculated using the half maximum height protocol of Spoor et al. (1993) for each skull, and thresholds used for crown segmentation were set visually for each tooth separately. Data was analysed using discriminant function analysis and posterior probabilities were calculated for all produced formulae where sex was previously assessed from morphological features of pelvis and skull. Bootstrapping was used to account for small sample sizes in the analysis. Statistical analysis was carried out using SPSS 23. The percentage of sexual dimorphism was also used to quantify the amount of sexual dimorphism in the sample. The results showed that incisors and canines were the most sexually dimorphic teeth, providing percentages of correct sex classification between 80% and 100% depending on the measurement used. Root volume measurement was shown to be the most sexually dimorphic variable providing an accuracy of over 90% in all functions. The present study provided the first dental metric standards for sex estimation using odontometric data in Iranian archaeological populations. Dental measurements, particularly root volume measurements, were found to be of value for sex assessment and the method presented here could be a useful tool for establishing accurate demographic data from skeletal remains of the Iron Age from Iran

Identification of a delta5-like fatty acyl desaturase from the cephalopod Octopus vulgaris (Cuvier 1797) involved in the biosynthesis of essential fatty acids

Long-chain polyunsaturated fatty acids (LC-PUFA) have been identified as essential compounds for common octopus (Octopus vulgaris), but precise dietary requirements have not been determined due in part to the inherent difficulties of performing feeding trials on paralarvae. Our objective is to establish the essential fatty acid (EFA) requirements for paralarval stages of the common octopus through characterisation of the enzymes of endogenous LC-PUFA biosynthetic pathways. In this study we isolated a cDNA with high homology to fatty acyl desaturases (Fad). Functional characterisation in recombinant yeast showed the octopus Fad exhibited ∆5 desaturation activity towards saturated and polyunsaturated fatty acyl substrates. Thus, it efficiently converted the yeast’s endogenous 16:0 and 18:0 to 16:1n-11 and 18:1n-13, respectively, and desaturated exogenously added PUFA substrates, 20:4n-3 and 20:3n-6, to 20:5n-3 (EPA) and 20:4n-6 (ARA), respectively. Although the ∆5 Fad enables common octopus to produce EPA and ARA, the low availability of its adequate substrates 20:4n-3 and 20:3n-6, either in the diet or by limited endogenous synthesis from C18 PUFA, might indicate that EPA and ARA are indeed EFA for this species. Interestingly, the octopus ∆5 Fad can also participate in the biosynthesis of non-methylene interrupted FA, PUFA that are generally uncommon in vertebrates but that have been found previously in marine invertebrates including molluscs, and now also confirmed to be present in specific tissues of common octopus

Mechanism of formation of silver N-heterocyclic carbenes using silver oxide: A theoretical study

The reasons for the efficiency of the silver oxide route in the synthesis of Ag(I) N-heterocyclic carbene complexes have been investigated by means of DFT calculations. A general reaction system that incorporates two N,N-dimethyl imidazolium cations, two iodides as the counterions, Ag2O, and dichloromethane solvent was considered. Exploration of several pathways for the formation of the two silver−NHC cations gives a clear picture for the reaction mechanism. The favored route involves a barrierless and very exergonic deprotonation of the first imidazolium followed by a low barrier and also exergonic metalation, affording the first silver−NHC. The second imidazolium assists these two steps stabilizing intermediates and the transition state by the formation of a strong Cimidazolium−H···OAg hydrogen bond. The formed [R2NHC]−AgI then diffuses in the solution, while silver hydroxide deprotonates the second imidazolium salt in a slightly endergonic process. After metalation, the second silver−NHC is obtained. The overall reaction is thermodynamically driven, the conversion of two imidazolium salts to two silver carbenes entailing a system stabilization of more than 70 kcal mol-1. As the acid−base reaction between the imidazolium salt and the silver base plays a key role in the process, pKa calculations were performed to compare the basicity of the N-heterocyclic carbene with those of the silver bases Ag2O, AgOH, and AgOAc. From the pKa values obtained, the advantage of silver oxide in the generation of silver carbenes is attributed to its stronger basicity

Metal-Organic Frameworks as Chemical Nanoreactors: Synthesis and Stabilization of Catalytically Active Metal Species in Confined Spaces

ConspectusSince the advent of the first metal-organic frameworks (MOFs), we have witnessed an explosion of captivating architectures with exciting physicochemical properties and applications in a wide range of fields. This, in part, can be understood under the light of their rich host-guest chemistry and the possibility to use single-crystal X-ray diffraction (SC-XRD) as a basic characterization tool. Moreover, chemistry on preformed MOFs, applying recent developments in template-directed synthesis and postsynthetic methodologies (PSMs), has shown to be a powerful synthetic tool to (i) tailor MOFs channels of known topology via single-crystal to single-crystal (SC-SC) processes, (ii) impart higher degrees of complexity and heterogeneity within them, and most importantly, (iii) improve their capabilities toward applications with respect to the parent MOFs. However, the unique properties of MOFs have been, somehow, limited and underestimated. This is clearly reflected on the use of MOFs as chemical nanoreactors, which has been barely uncovered. In this Account, we bring together our recent advances on the construction of MOFs with appealing properties to act as chemical nanoreactors and be used to synthesize and stabilize, within their channels, catalytically active species that otherwise could be hardly accessible. First, through two relevant examples, we present the potential of the metalloligand approach to build highly robust and crystalline oxamato- and oxamidato-MOFs with tailored channels, in terms of size, charge and functionality. These are initial requisites to have a playground where we can develop and fully take advantage of singular properties of MOFs as well as visualize/understand the processes that take place within MOFs pores and somehow make structure-functionalities correlations and develop more performant MOFs nanoreactors. Then, we describe how to exploit the unique and singular features that offer each of these MOFs confined space for (i) the incorporation and stabilization of metals salts and complexes, (ii) the in situ stepwise synthesis of subnanometric metal clusters (SNMCs), and (iii) the confined-space self-assembly of supramolecular coordination complexes (SCCs), by means of PSMs and underpinned by SC-XRD. The strategy outlined here has led to unique rewards such as the highly challenging gram-scale preparation of stable and well-defined ligand-free SNMCs, exhibiting outstanding catalytic activities, and the preparation of unique SCCs, different to those assembled in solution, with enhanced stabilities, catalytic activities, recyclabilities, and selectivities. The results presented in this Accounts are just a few recent examples, but highly encouraging, of the large potential way of MOFs acting as chemical nanoreactors. More work is needed to found the boundaries and fully understand the chemistry in the confined space. In this sense, mastering the synthetic chemistry of discrete organic molecules and inorganic complexes has basically changed our way of live. Thus, achieving the same degree of control on extended hybrid networks will open new frontiers of knowledge with unforeseen possibilities. We aim to stimulate the interest of researchers working in broadly different fields to fully unleash the host-guest chemistry in MOFs as chemical nanoreactors with exclusive functional species.This work was supported by the MINECO (Spain) (ProjectsCTQ2016-75671-P, 2017-86735-P, and Excellence Units“Severo Ochoa”and“Maria de Maeztu”SEV-2016-0683 andMDM-2015-0538) and the Ministero dell’Istruzione, dell’Uni-versitàe della Ricerca (Italy). Thanks are also extended to the“2019 Post-Doctoral Junior Leader-Retaining Fellowship, laCaixa Foundation (ID100010434 and Fellowship Code LCF/BQ/PR19/11700011”(J. F.-S.) and the Diamond LightSource for awarded beamtime and provision of synchrotronradiation facility at I19 beamline (D. A.). E.P. acknowledges thefinancial support of the European Research Council underthe European Union’s Horizon 2020 Research and InnovationProgramme/ERC Grant Agreement No. 814804, MOF-reactors

Coordination versatility of 5(3)-(2-hydroxyphenyl)-3(5)-methylpyrazole: Synthesis, crystal structure and properties of Co-III, Ni-II and Cu-II complexes

Item does not contain fulltextNew complexes with 5(3)-(2-hydroxyphenyl)-3(5)-methylpyrazole (H(2)phpz), [Co-2(H(2)phpz)(Hphpz)(2)(phpz)(2)](.)3CH(3)CN (1), [Ni(Hphpz)(2)] (2) and [Cu(HphpZ)(2)] (3), were synthesized and structurally characterized. The ligand coordinates in the form of 3-(2-hydroxyphenyl)-5-methylpyrazole in all cases, except for one ligand in the Co-III complex, where it coordinates in the 5-(2-hydroxyphenyl)-3-methylpyrazole mode. Crystallographic analysis revealed that 1 contains two chemically and crystallographically distinct cobalt(III) ions triply bridged by one phenoxide and two pyrazolate groups, giving rise to a [Co-2(N-N)(2)O] core with a (CoCo)-Co-... distance of 3.154 angstrom. Additionally, the H(2)phpz ligand shows four different coordination modes with the metal ions, demonstrating its versatility. The dinuclear unit of 1 is stabilized by strong intramolecular N-(HO)-O-... hydrogen-bonding interactions involving the phenol oxygen atom of the H(2)phpz ligand and the N-H functionality of the pyrazole ring. The crystal structure of the isomorphous complexes 2 and 3 reveals the presence of centrosymmetric mononuclear units with the MN2O2 [M = Ni-II (2), Cu-II (3)] chromophore displaying a slightly distorted square-planar geometry. The mononuclear structures of 2 and 3 are further stabilized by intramolecular hydrogen bonds established between the acid N-H group as donor and the phenoxide group of the H(2)phpz ligand as acceptor. Spectroscopic studies, ESI-MS and cyclic voltammetry were performed, supporting the crystallographic analysis. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Fatty acid composition of polar and neutral lipid fractions of Octopus vulgaris Cuvier, 1797 paralarvae reared with enriched on-grown Artemia

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