Comparison of sperm preparation methods to improve the recovery of mature spermatozoa in sub-fertile males.

The integrity of chromatin in the spermatozoon is essential for reproductive outcome. The aim of this study was to evaluate the most effective and cost-effective method to reduce the percentage of spermatozoa with defects in chromatin decondensation for use in assisted reproductive technologies (ART) procedures. Sperm samples from 15 sub-fertile males were examined at CFA Naples to determine the sperm decondensation index (SDI), using the aniline blue test, before and after preparation, comparing density gradients with two different swim-up approaches. All three techniques led to a reduction in decondensed spermatozoa with no statistical difference (P > 0.05) between the control and the treated sperm. In contrast, we found a highly significant decrease in SDI (P < 0.01) after the two swim-up methods in all the samples, confirming the efficacy of these methods in lowering the percentage of chromatin compaction damage. There was no statistical difference between the two swim-up methods, however swim-up from the pellet led to improved count, motility and the percentage of normal condensed spermatozoa. We suggest that swim-up from the pellet be used in ART on sub-fertile males, both to reduce cell stress by multiple centrifugation and improve the recovery rate of mature spermatozoa.

A close view of the organic linker in a MOF: structural insights from a combined 1H NMR relaxometry and computational investigation.

The organic linker in a metal organic framework (MOF) affects its adsorption behavior and performance, and its structure and dynamics play a role in the modulation of the adsorption properties. In this work, the combination of 1H nuclear magnetic resonance (NMR) longitudinal relaxometry and theoretical calculations allowed details of the structure and dynamics of the organic linker in the NH2-MIL-125 MOF to be obtained. In particular, fast field cycling (FFC) NMR, applied here for the first time on MOFs, was used to disclose the dynamics of the amino group and its electronic environment through the analysis of the 14N quadrupole relaxation peaks, observed in the frequency interval 0.5-5 MHz, at different temperatures from 25 to 110 °C. The line width of the peaks allowed a lower boundary on the rotational correlation time of the N-H bonds to be set, whereas relevant changes in the amplitudes were interpreted in terms of a change in the orientation of the 14N averaged electric field gradient tensor. The experimental findings were complemented by quantum chemistry calculations and classical molecular dynamics simulations.

Dynamics of poly(vinyl butyral) studied using dielectric spectroscopy and 1H NMR relaxometry.

Dielectric Spectroscopy (DS) and 1H Fast Field-Cycling (FFC) NMR relaxometry were applied for understanding the dynamic behavior of the amorphous ter-polymer poly(vinyl butyral) (PVB) across the glass transition temperature (Tg = 70 °C by Differential Scanning Calorimetry). Above Tg, main chain segmental motions (α relaxation) were detected and characterized using both DS and FFC NMR relaxometry. The correlation times extracted by the analysis of DS and FFC NMR relaxometry data agreed within a factor of three and showed a Vogel-Fulcher-Tammann temperature dependence, with an associated Tg of 69 °C and a fragility of 155 for PVB glass. Below Tg, a secondary process (ß relaxation) was revealed by DS, and was ascribed to reorientations of the vinyl alcohol dipoles due to local twisting motions with an associated activation barrier of 11 kcal mol-1. The ß process was also found to contribute to 1H NMR relaxation above Tg.

Copper(II) complexes with peptides based on the second cell binding site of fibronectin: metal coordination and ligand exchange kinetics.

Copper(ii) complexes with short peptides based on the second cell binding site of fibronectin, PHSFN and PHSEN, have been characterized by potentiometric, UV-vis, CD, EPR and NMR spectroscopic methods. The histidine imidazole nitrogen is the anchoring site for the metal ion binding. Thermodynamic and spectroscopic evidence is given that the side chain oxygen donor atom of glutamyl residue in Ac-PHSEN-NH2 is also involved in the binding up to physiological pH. To determine ligand exchange kinetic parameters after the imidazole nitrogen anchoring, proton relaxation enhancement NMR data have been collected for the two hydrogen atoms of the imidazole ring in the temperature range 293-315 K at pH 5.2 and globally treated within different kinetic models for ligand exchange. The best fitting model involves two steps. In the first one, which is slow, a water molecule disengages a carbonyl or a carboxylate group coordinated to the metal ion in the complex formed by PHSFN or PHSEN, respectively. This stage is one order of magnitude slower for PHSEN, due to entropic effects. In the second step, which is fast, the complex just formed exchanges with the ligand. In this step, no appreciable differences are found for the two cases examined.

Gd-doped BNNTs as T2-weighted MRI contrast agents.

This work describes, for the first time, doping of boron nitride nanotubes (BNNTs) with gadolinium (Gd@BNNTs), a stable functionalization that permits non-invasive BNNT tracking via magnetic resonance imaging (MRI). We report the structure, Gd loading, and relaxometric properties in water suspension at 7 T of Gd@BNNTs, and show the behaviour of these nanostructures as promising T2-weighted contrast agents. Finally, we demonstrate their complete biocompatibility in vitro on human neuroblastoma cells, together with their ability to effectively label and affect contrast in MRI images at 7 T.

Effects of post-reactor functionalization on the phase behaviour of an ethylene-1-octene copolymer studied using solid-state high resolution 13C NMR spectroscopy.

The effects of post-reactor functionalization with naphthoate-TEMPO on the structure and morphology of an ethylene-1-octene copolymer were investigated by means of solid-state NMR techniques and DSC measurements. Selective (13)C MAS experiments allowed the orthorhombic and the monoclinic crystalline phases and two amorphous phases with different degree of mobility to be detected and quantified. (13)C and (1)H relaxation time measurements and spin diffusion experiments gave insight into the polymer dynamics within the different phases, the crystalline domain dimensions, and the rate of chain diffusion between amorphous and crystalline phases. Comparison of the results obtained for the pristine copolymer and the functionalized samples clearly indicated that the functionalization procedure causes redistribution within the crystalline and the amorphous phases with no relevant change in the degree of crystallinity or in the crystalline domain average size, and slows down chain diffusion.

Mandated to fail? Humanitarian agencies and the protection of Palestinian children.

This paper considers the efforts of United Nations and international agencies to address the threats to Palestinian children arising from Israeli occupation. It contains an account of the reasons why agencies have failed, over many years, to prevent systematic violations by the Israeli authorities and settlers. The discussion is organised around two inter-related domains: institutional and political. The paper argues that, in the occupied Palestinian territory (oPt), limitations to the ways in which child protection has been conceptualised and pursued in practice are abundantly evident. Nevertheless, political pressure by Western donor governments serves to constrain an approach to child protection that is more preventative in nature, that addresses more explicitly Israeli violations of international law, and that reflects the experience and aspirations of Palestinian children themselves. Ultimately, therefore, the failure to protect Palestinian children must be seen not only as a result of humanitarian miscalculation but also as a consequence of political strategy.

Decomposition of green tea and rooibos tea across three monospecific temperate forests: Effect of litter type and tree species.

We studied the effect of different forest covers on carbon (C) and nitrogen (N) dynamics of two standardised litters during decomposition in soil. For this purpose, commercially available bags containing green tea or rooibos tea were incubated in close monospecific stands of Fagus sylvatica, Pseudotsuga menziesii, and Quercus cerris, in the Apennines range, Italy, and then analysed at different intervals for up to two years. We also investigated the fate of various C functional groups in both types of litter under beech by nuclear magnetic resonance spectroscopy. After two years of incubation, green tea had not changed its original C/N ratio of 10, while rooibos tea had nearly halved its original value of 45, because of different C and N dynamics. Both litters progressively lost C, about fifty per cent of the initial content in the case of rooibos tea, and a little more for green tea, most of the loss occurring in the first three months. In terms of N, green tea behaved as for C, while rooibos tea in the early stage lost part of its N stock, fully recovering it by the end of the first year. Under beech, both litters showed a preferential loss in carbohydrates during the first trimester of incubation and, consequently, an indirect enrichment in lipids. Later on, the relative contribution of the various C forms remained practically constant. Our results overall support that the decay rate and compositional changes of litter depend strongly on the litter type and little on the tree cover of the soil in which the litter is incubated.

Self-assembly and photo-cross-linking of eight-armed PEG-PTMC star block copolymers.

Eight-armed poly(ethylene glycol)-poly(trimethylene carbonate) star block copolymers (PEG-(PTMC)(8)) linked by a carbamate group between the PEG core and the PTMC blocks were synthesized by the metal-free, HCl-catalyzed ring-opening polymerization of trimethylene carbonate using an amine-terminated eight-armed star PEG in dichloromethane. Although dye solubilization experiments, nuclear magnetic resonance spectroscopy, and dynamic light scattering clearly indicated the presence of aggregates in aqueous dispersions of the copolymers, no physical gelation was observed up to high concentrations. PEG-(PTMC(9))(8) was end-group-functionalized using acryloyl chloride and photopolymerized in the presence of Irgacure 2959. When dilute aqueous dispersions of PEG-(PTMC(9))(8)-Acr were UV irradiated, chemically cross-linked PEG-PTMC nanoparticles were obtained, whereas irradiation of more concentrated PEG-(PTMC(9))(8)-Acr dispersions resulted in the formation of photo-cross-linked hydrogels. Their good mechanical properties and high stability against hydrolytic degradation make photo-cross-linked PEG-PTMC hydrogels interesting for biomedical applications such as matrices for tissue engineering and controlled drug delivery systems.

The Thermo-Oxidative Behavior of Cotton Coated with an Intumescent Flame Retardant Glycine-Derived Polyamidoamine: A Multi-Technique Study.

Linear polyamidoamines (PAAs) derived from the polyaddition of natural α-amino acids and N,N'-methylene bis(acrylamide) are intumescent flame retardants for cotton. Among them, the glycine-derived M-GLY extinguished the flame in horizontal flame spread tests at 4% by weight add-on. This paper reports on an extensive study aimed at understanding the molecular-level transformations of M-GLY-treated cotton upon heating in air at 300 °C, 350 °C and 420 °C. Thermogravimetric analysis (TGA) identified different thermal-oxidative decomposition stages and, coupled to Fourier transform infrared spectroscopy, allowed the volatile species released upon heating to be determined, revealing differences in the decomposition pattern of treated and untreated cotton. XPS analysis of the char residues of M-GLY-treated cotton revealed the formation of aromatic nanographitic char at lower temperature with respect to untreated cotton. Raman spectroscopy of the char residues provided indications on the degree of graphitization of treated and untreated cotton at the three reference temperatures. Solid state 13C nuclear magnetic resonance spectroscopy (NMR) provided information on the char structure as a function of the treatment temperature, clearly indicating that M-GLY favors the carbonization of cotton with the formation of more highly condensed aromatic structures.

Self-aggregation of gel forming PEG-PLA star block copolymers in water.

The aggregation behavior and dynamics of poly(ethylene glycol) (PEG) and poly(lactide) (PLA) chains in a homologous series of eight-armed PEG-PLA star block copolymers ((PEG(65)-NHCO-PLA(n))(8) with n = 11, 13, and 15) in water at different concentrations and temperatures were studied by means of (1)H and (13)C NMR spectroscopy and (1)H longitudinal relaxation time analysis. The state of water in these systems was also investigated through the combined use of (1)H and (2)H longitudinal relaxation time measurement. On the basis of the NMR experimental findings and of dynamic light scattering measurements, (PEG(65)-NHCO-PLA(n))(8) in water can be described as self-aggregated systems with quite rigid hydrophobic domains made of PLA chains and aqueous domains where both PEG chains and water molecules undergo fast dynamics. A smaller number of rigid domains was found for (PEG(65)-NHCO-PLA(11))(8) with respect to the homologous copolymers with longer PLA chains. At low concentrations, the PLA domains are mainly formed by chains belonging to the same molecule, thus giving rise to unimolecular micelles. At intermediate concentrations, that is, above the critical association concentration (CAC) but below the critical gel concentration (CGC), nanogels are formed by interconnection of several PLA domains through shared unimers. Above the CGC, the network is extended to the entire system, giving rise to macroscopic gels. In all cases, a fraction of PLA chains remains quite mobile and exposed to water due to topological constraints of the star architecture.

Influence of amide versus ester linkages on the properties of eight-armed PEG-PLA star block copolymer hydrogels.

Water-soluble eight-armed poly(ethylene glycol)-poly(l-lactide) star block copolymers linked by an amide or ester group between the PEG core and the PLA blocks (PEG-(NHCO)-(PLA)(8) and PEG-(OCO)-(PLA)(8)) were synthesized by the stannous octoate catalyzed ring-opening polymerization of l-lactide using an amine- or hydroxyl-terminated eight-armed star PEG. At concentrations above the critical gel concentration, thermosensitive hydrogels were obtained, showing a reversible single gel-to-sol transition. At similar composition PEG-(NHCO)-(PLA)(8) hydrogels were formed at significantly lower polymer concentrations and had higher storage moduli. Whereas the hydrolytic degradation/dissolution of the PEG-(OCO)-(PLA)(8) takes place by preferential hydrolysis of the ester bond between the PEG and PLA block, the PEG-(NHCO)-(PLA)(8) hydrogels degrade through hydrolysis of ester bonds in the PLA main chain. Because of their relatively good mechanical properties and slow degradation in vitro, PEG-(NHCO)-(PLA)(8) hydrogels are interesting materials for biomedical applications such as controlled drug delivery systems and matrices for tissue engineering.

What can the global movement to end child marriage learn from the implementation of other multi-sectoral initiatives?

If the Sustainable Development Goal (SDG) target 5.3 to end child marriage by 2030 is to be met, the annual rate of reduction in the prevalence of child marriage must increase from 1.9% to 23%. Over 30 countries have developed, or are developing, national policies/programmes towards this goal. However, many are struggling to operationalise these policies/programmes, particularly at subnational levels. Thus, Girls Not Brides and the WHO commissioned a review of lessons learnt from national and subnational implementation of multi-sectoral policies/programmes targeting other issues that could be applied to the global movement to end child marriage. This review identified a number of pragmatic lessons learnt. At the national level, countries should identify and engage committed and skilled leadership, build a shared understanding of the target issue and how to address it, and delineate and clarify the roles and responsibilities of relevant stakeholders. At the subnational level, countries should establish coordination mechanisms, build awareness and capacity of staff, use subnational evidence to contextualise and tailor interventions, develop coordinated budgets and cost-sharing mechanisms, and integrate monitoring and evaluation systems. These lessons are remarkably consistent, despite coming from different target issues and contexts. The commonality of these findings reveals that various stakeholders are repeatedly and consistently failing to ensure that these fundamental requirements are in place. It is vital that the global movement to end child marriage learns from and uses these lessons if it is to meet its SDG target.

Chromium isotopes tracking the resurgence of hexavalent chromium contamination in a past-contaminated area in the Friuli Venezia Giulia Region, northern Italy.

The origin of a resurgent hexavalent chromium contamination in groundwater from a phreatic aquifer in the Friuli Venezia Giulia Region plain was investigated by chromium isotopic systematics. The area underwent a severe Cr(VI) contamination by industrial effluents in 1997, when Cr(VI) concentration in groundwater reached 4500 µg/L. In subsequent years the contamination naturally attenuated, totally disappearing in 2003. A renewal of water contamination was observed in 2008, Cr(VI) reaching 1560 µg/L. The δ53Cr value in groundwater and extracts from sediments was measured in 2009-2011, and it ranges between -3.21 and +0.21‰ and between -4.71 and +1.26‰, respectively. Due to the lack of geogenic Cr-sources, these data are interpreted as evidence of the subsequent oxidation through Mn-oxides of the Cr(III) hosted in the aquifer and originated by the reduction of the original industrial chromates. Cr(III) is characterized by negative δ53Cr, starting from the δ53Cr value around zero of Cr(VI) in industrial effluents. Oxidation liberates soluble Cr(VI) which is transported by groundwater and permeated soils. The complex Cr-isotopic vs. concentration distribution reflects both the new Cr(VI) reduction and dilution processes in the aquifer system. From an environmental point of view, the data raise concerns regarding the potential impact of past Cr(VI)-contamination.

Interaction of a tripeptide with cesium perfluorooctanoate micelles.

The interaction of alanyl-phenylalanyl-alanine (Ala-Phe-Ala) with the micelles formed by cesium perfluorooctanoate (CsPFO) in water was studied in the isotropic phase by means of 1H NMR and by molecular dynamics (MD) simulations. Information on the location of the peptide was experimentally obtained from selective variations in Ala-Phe-Ala chemical shifts and from differential line broadening in the presence of the paramagnetic ion Mn2+. The peptide-micelle association constant was estimated analyzing the chemical shift variations of the most sensitive Ala-Phe-Ala resonances with the peptide concentration. MD simulations of Ala-Phe-Ala in the micellar environment confirmed the experimental observations, identifying the hydrogen bonding interactions of the different peptide moieties with the micelle, yielding a binding constant close to the experimental one. NOESY experiments suggest that the peptide in the micellar environment does not adopt a preferred conformation but is mainly unstructured. Details on the conformational behavior of the peptide in the micellar solution observed through MD were consistent with a different conformational equilibrium in the proximity of the micelle. Information on Ala-Phe-Ala dynamics was obtained from 1H T1 data and compared to MD simulation results on the overall tumbling motion.

Water/polymer interactions in poly(amidoamine) hydrogels by 1H nuclear magnetic resonance relaxation and magnetization transfer.

Hydrated cross-linked polymers belonging to the family of poly(amidoamine)s were investigated by high and low resolution (1)H nuclear magnetic resonance techniques in order to obtain information on water/polymer interactions in the swollen state. (1)H spin-spin and spin-lattice relaxation time analysis, as well as magnetization transfer experiments, indicated that water and polymer proton pools are essentially uncoupled, with water molecules diffusing fast within the hydrogel structure and exchanging between "bound" and free sites. For the polymer characterized by the highest cross-linking degree, there is strong evidence of a beadlike structure resulting in higher network rigidity and hydrogel micrometric heterogeneity.

Dynamics of Dimethylbutanols in Plastic Crystalline Phases by Field Cycling 1H NMR Relaxometry.

2,2-Dimethylbutan-1-ol (2,2-DM-1-B), 3,3-dimethylbutan-1-ol (3,3-DM-1-B), and 3,3-dimethylbutan-2-ol (3,3-DM-2-B) show a rich solid-state polymorphism, which includes one or more plastic crystalline phases (also referred to as orientationally disordered crystalline (ODIC) phases) and glass of the liquid or ODIC phases. In this work, the dynamics of the three isomeric alcohols was investigated in the liquid and plastic crystalline phases by fast field cycling 1H NMR relaxometry in the temperature range between 213 and 303 K. The analysis of the nuclear magnetic relaxation dispersion curves (i.e., longitudinal relaxation rate R1 vs 1H Larmor frequency) acquired for the different alcohols at different temperatures gave quantitative information on internal motions, overall molecular reorientations, and molecular self-diffusion. Self-diffusion coefficients were also determined in the liquid phase and in some ODIC phases of the samples from the trends of 1H R1 as a function of the frequency square root at low frequencies. Remarkable changes in the temperature trends of correlation times and self-diffusion coefficients were found at the transition between the liquid and the ODIC phase for 2,2-DM-1-B and 3,3-DM-1-B, and between ODIC phases for 3,3-DM-2-B, the latter sample showing a markedly different dynamic and phase behavior.

Conformations of banana-shaped molecules studied by 2H NMR spectroscopy in liquid crystalline solvents.

ClPbis11BB and Pbis11BB, two banana-shaped mesogens differing by a chlorine substituent on the central phenyl ring, show a nematic and a B2 phase, respectively. To obtain information on the structural features responsible for their different mesomorphic behavior, a study of the preferred conformations of these mesogens has been performed by NMR spectroscopy in two nematic media (Phase IV and ZLI1167), which should mimic the environment of the molecules in their own mesophases, avoiding problems of sample alignment by a magnetic field. To this aim, 2H NMR experiments have been performed on selectively deuterated isotopomers of ClPbis11BB and Pbis11BB and of two parent molecules, ClPbisB and PbisB, assumed as models in previous theoretical and experimental conformational studies. We found that only a limited number of conformations is compatible with experimental data, often very different from those inferred from theoretical calculations in vacuo, indicating a strong influence of the liquid crystalline environment on molecular conformation. No significant differences between chlorinated and non-chlorinated molecules were found, this suggesting that chlorine does not change the molecular conformational equilibrium, as previously proposed.

Dynamics of the Chiral Liquid Crystal 4'-Butyl-4-(S)-(2-methylbutoxy)azoxybenzene in the Isotropic, Cholesteric, and Solid Phases: A Fast Field-Cycling NMR Relaxometry Study.

(1)H NMR relaxometry was applied to investigate dynamic processes in the isotropic liquid, cholesteric, and crystalline phases of the chiral mesogen 4'-butyl-4-(S)-(2-methylbutoxy)azoxybenzene (4ABO5*). To this aim, (1)H longitudinal relaxation rates were measured as a function of temperature (between 257 and 319 K) and Larmor frequency (from 10 kHz to 35 MHz by a fast field-cycling relaxometer and at 400 MHz by an NMR spectrometer). The NMR relaxation dispersion (NMRD) curves so obtained were analyzed in terms of models suitable for the description of dynamic processes in the different phases, thus quantitatively determining values of characteristic motional parameters. In particular, internal and overall rotations/reorientations, molecular translational diffusion, and collective motions contribute to relaxation in the isotropic and cholesteric phases, whereas, in the crystalline phase, relaxation is mainly determined by internal motions and molecular reorientations. The results were discussed and compared with those previously obtained on the same compound by dielectric relaxation spectroscopy.

Conformation and orientation of tetraalanine in a lyotropic liquid crystal studied by nuclear magnetic resonance.

The (1)H NMR spectra of two isotopomers of tetraalanine deuterated on the two external methyl groups and on the two internal ones, respectively, were recorded in the lyotropic solvent cesium pentadecafluorooctanoate (CsPFO)/water. Eight dipolar couplings could be estimated from the spectra. The set of dipolar couplings was fitted assuming that one rigid conformer is present. Of the four major conformers considered, selected on the basis of theoretical calculations, the one characterized by the two couples of internal dihedral angles in the Ramachandran region of PPII resulted to be the only one to fit the set of couplings within experimental error. The data indicate that the molecule is oriented with the long molecular axis tilted with respect to the surface of the micelles formed by CsPFO.