Coral micro- and macro-morphological skeletal properties in response to life-long acclimatization at CO vents in Papua New Guinea.

This study investigates the effects of long-term exposure to OA on skeletal parameters of four tropical zooxanthellate corals naturally living at CO seeps and adjacent control sites from two locations (Dobu and Upa Upasina) in the Papua New Guinea underwater volcanic vent system. The seeps are characterized by seawater pH values ranging from 8.0 to about 7.

Characterization of Structural Bone Properties through Portable Single-Sided NMR Devices: State of the Art and Future Perspectives.

Nuclear Magnetic Resonance (NMR) is a well-suited methodology to study bone composition and structural properties. This is because the NMR parameters, such as the T2 relaxation time, are sensitive to the chemical and physical environment of the H nuclei. Although magnetic resonance imaging (MRI) allows bone structure assessment in vivo, its cost limits the suitability of conventional MRI for routine bone screening.

Single-sided NMR to estimate morphological parameters of the trabecular bone structure.

Purpose: Single-sided H-NMR is proposed for the estimation of morphological parameters of trabecular bone, and potentially the detection of pathophysiological alterations of bone structure. In this study, a new methodology was used to estimate such parameters without using an external reference signal, and to study intratrabecular and intertrabecular porosities, with a view to eventually scanning patients.

Methods: Animal trabecular bone samples were analyzed by a single-sided device.

Along-tract analysis of the arcuate fasciculus using the Laplacian operator to evaluate different tractography methods.

Purpose: We propose a new along-tract algorithm to compare different tractography algorithms in tract curvature mapping and along-tract analysis of the arcuate fasciculus (AF). In particular, we quantified along-tract diffusion parameters and AF spatial distribution evaluating hemispheric asymmetries in a group of healthy subjects.

Methods: The AF was bilaterally reconstructed in a group of 29 healthy subjects using the probabilistic ball-and-sticks model, and both deterministic and probabilistic constrained spherical deconvolution.

An Environmental Friendly Fluorinated Oligoamide for Producing Nonwetting Coatings with High Performance on Porous Surfaces.

The changes in the surface wettability of many materials are receiving increased attention in recent years. It is not too hard to fabricate resistant hydrophobic surfaces through products bearing both hydrophobic and reactive hydrophilic end groups. More challenging is obtaining resistant nonwetting surfaces through noncovalent reversible bonds.

Bone volume-to-total volume ratio measured in trabecular bone by single-sided NMR devices.

Purpose: Reduced bone strength is associated with a loss of bone mass, usually evaluated by dual-energy X-ray absorptiometry, although it is known that the bone microstructure also affects the bone strength. Here, a method is proposed to measure (in laboratory) the bone volume-to-total volume ratio by single-sided NMR scanners, which is related to the microstructure of the trabecular bone.

Methods: Three single-sided scanners were used on animal bone samples.

Ocean warming and acidification synergistically increase coral mortality.

Organisms that accumulate calcium carbonate structures are particularly vulnerable to ocean warming (OW) and ocean acidification (OA), potentially reducing the socioeconomic benefits of ecosystems reliant on these taxa. Since rising atmospheric CO is responsible for global warming and increasing ocean acidity, to correctly predict how OW and OA will affect marine organisms, their possible interactive effects must be assessed. Here we investigate, in the field, the combined temperature (range: 16-26 °C) and acidification (range: pH 8.

The effect of diffusion gradient direction number on corticospinal tractography in the human brain: an along-tract analysis.

Objectives: We evaluated diffusion imaging measures of the corticospinal tract obtained with a probabilistic tractography algorithm applied to data of two acquisition protocols based on different numbers of diffusion gradient directions (NDGDs).

Materials And Methods: The corticospinal tracts (CST) of 18 healthy subjects were delineated using 22 and 66-NDGD data. An along-tract analysis of diffusion metrics was performed to detect possible local differences due to NDGD.

Shell properties of commercial clam Chamelea gallina are influenced by temperature and solar radiation along a wide latitudinal gradient.

Phenotype can express different morphologies in response to biotic or abiotic environmental influences. Mollusks are particularly sensitive to different environmental parameters, showing macroscale shell morphology variations in response to environmental parameters. Few studies concern shell variations at the different scale levels along environmental gradients.

Isotropic microscale mechanical properties of coral skeletons.

Scleractinian corals are a major source of biogenic calcium carbonate, yet the relationship between their skeletal microstructure and mechanical properties has been scarcely studied. In this work, the skeletons of two coral species:solitary Balanophyllia europaea and colonial Stylophora pistillata, were investigated by nanoindentation. The hardness HIT and Young's modulus E(IT) were determined from the analysis of several load-depth data on two perpendicular sections of the skeletons: longitudinal (parallel to the main growth axis) and transverse.

Stone porosity, wettability changes and other features detected by MRI and NMR relaxometry: a more than 15-year study.

Scientists applying magnetic resonance techniques to cultural heritage are now a quite vast and international community, even if these applications are not yet well known outside this community. Not only laboratory experiments but also measurements in the field are now possible, with the use of portable nuclear magnetic resonance (NMR) instruments that enable non-invasive and non-destructive studies on items of any size, of high artistic and historical value as well as diagnosis of their conservation state. The situation was completely different in the second half of the 1990s when our group started working on applications of NMR to cultural heritage, by combining the knowledge of NMR for fluids in porous media at the University of Bologna, with the skilfulness of the chemists for cultural heritage of CNR and University of Florence, and Safeguarding Cultural Heritage Department of Aosta.

Nano and sub-nano multiscale porosity formation and other features revealed by 1H NMR relaxometry during cement hydration.

Cement hydration occurs when water is added to cement powder, leading to the formation of crystalline products like Portlandite and the quasi-amorphous, poorly crystalline, calcium silicate hydrate (C-S-H) gel. Despite its importance in determining the final properties of the cement, many models exist for the nano and sub-nano level organization of this "liquid stone." (1)H NMR relaxometry in White Portland Cement paste during hydration allowed us to monitor the formation and evolution of the multiscale porosity of the cement, with the formation of structures at nano and sub-nano levels of C-S-H gel (calcium silicate interlayer water, water in small and large gel pores) along with three low-mobility (1)H pools, identified as (1)H nuclei in C-S-H layers, likely belonging to OH groups, with (1)H nuclei in Portlandite, and in crystal water of Ettringite.

Biomineralization control related to population density under ocean acidification.

Anthropogenic CO is a major driver of current environmental change in most ecosystems, and the related ocean acidification (OA) is threatening marine biota. With increasing pCO, calcification rates of several species decrease, although cases of up-regulation are observed. Here, we show that biological control over mineralization relates to species abundance along a natural pH gradient.

A time-domain nuclear magnetic resonance study of Mediterranean scleractinian corals reveals skeletal-porosity sensitivity to environmental changes.

Mediterranean corals are a natural model for studying global warming, as the Mediterranean basin is expected to be one of the most affected regions and the increase in temperature is one of the greatest threats for coral survival. We have analyzed for the first time with time-domain nuclear magnetic resonance (TD-NMR) the porosity and pore-space structure, important aspects of coral skeletons, of two scleractinian corals, Balanophyllia europaea (zooxanthellate) and Leptopsammia pruvoti (nonzooxanthellate), taken from three different sites on the western Italian coast along a temperature gradient. Comparisons have been made with mercury intrusion porosimetry and scanning electron microscopy images.

Analysis of inter-fraction setup errors and organ motion by daily kilovoltage cone beam computed tomography in intensity modulated radiotherapy of prostate cancer.

Background: Intensity-modulated radiotherapy (IMRT) enables a better conformality to the target while sparing the surrounding normal tissues and potentially allows to increase the dose to the target, if this is precisely and accurately determined. The goal of this work is to determine inter-fraction setup errors and prostate motion in IMRT for localized prostate cancer, guided by daily kilovoltage cone beam computed tomography (kVCBCT).

Methods: Systematic and random components of the shifts were retrospectively evaluated by comparing two matching modalities (automatic bone and manual soft-tissue) between each of the 641 daily kVCBCTs (18 patients) and the planning kVCT.

PERFIDI filters to suppress and/or quantify relaxation time components in multi-component systems: an example for fat-water systems.

Parametrically Enabled Relaxation FIlters with Double and multiple Inversion (PERFIDI) is an experimental NMR/MRI technique devised to analyze samples/voxels characterized by multi-exponential longitudinal relaxation. It is based on a linear combination of NMR sequences with suitable preambles composed of inversion pulses. Given any standard NMR/MRI sequence, it permits one to modify it in a way which will attenuate, in a predictable manner and before data acquisition, signals arising from components with different r rates (r=1/T1).

Nanopore structure buildup during endodontic cement hydration studied by time-domain nuclear magnetic resonance of lower and higher mobility 1H.

Time-domain nuclear magnetic resonance (TD-NMR) of (1)H nuclei has been used to monitor and model changes of endodontic cement pastes during hydration, from the initial reaction period up to hours and days. The (1)H in the samples are divided into two major spin groups by fitting each free induction decay, acquired after the second pulse of an inversion recovery (I-R) pulse sequence with variable interpulse delay, by the sum of a quasi-Gaussian (signal from low mobility nuclei) and an exponential (from higher mobility nuclei). The extrapolations to zero time of the signals from the two spin groups give two sets of I-R data that have been analyzed to give quasi-continuous T(1) distributions.

Inhomogeneity of rat vertebrae trabecular architecture by high-field 3D mu-magnetic resonance imaging and variable threshold image segmentation.

Purpose: To analyze the 3D microarchitecture of rat lumbar vertebrae by micro-magnetic resonance imaging (micro-MRI).

Materials And Methods: micro-MR images (20 x 20 x 20 microm(3) apparent voxel size) were acquired with a three-dimensional spin-echo pulse sequence on four lumbar vertebrae of two rats. Apparent microarchitectural parameters like trabecular bone fraction (BV/TV), specific bone surface (BS/TV), mean intercept length (MIL), and Euler number per unit volume (Euler density, E(V)) were calculated using a novel semiquantitative variable threshold segmentation technique.

Water vapor absorption in porous media polluted by calcium nitrate studied by time domain nuclear magnetic resonance.

Nuclear magnetic resonance relaxation analysis of liquid water (1)H nuclei in real porous media, selected for their similar composition (carbonate rocks) and different pore space architecture, polluted with calcium nitrate, is presented to study the kinetics of water condensation and salt deliquescence inside the pore space. These phenomena are responsible for deterioration of porous materials when exposed to environmental injury by pollution in a humid atmosphere. The theory is well described for simple pore geometries, but it is not yet well understood in real porous media with wide distributions of pore sizes and connections.

Use of Magnetic Resonance Imaging for monitoring Parma dry-cured ham processing.

Protocols were developed to apply Magnetic Resonance Imaging (MRI) to the dry-curing of Italian Parma ham. NMR relaxation analyses were performed on dry-cured hams at different processing stages to evaluate the ranges of variation of (1)H relaxation times T(1) and T(2) in representative ham muscle tissues, due to dehydration and salt uptake. MRI maps of the same ham sections were acquired, allowing T(1) and T(2) average values to be computed in selected Regions of Interest (ROI) inside muscle Semimembranosus, Semitendinosus and Biceps femoris.

Validity of NMR pore-size analysis of cultural heritage ancient building materials containing magnetic impurities.

NMR relaxation time distributions, obtained with laboratory and portable devices, are utilized to characterize the pore-size distributions of building materials coming from the Roman remains of the Greek-Roman Theatre of Taormina. To validate the interpretation of relaxation data in terms of pore-size distribution, comparison of results from standard and in situ NMR experiments with results of the mercury intrusion porosimetry (MIP) has been made. Although the pore-size distributions can be obtained by NMR in terms of either longitudinal (T(1)) or transverse (T(2)) relaxation times distributions, the shorter duration of the T(2) measurement makes it, in principle, preferable, although the determination of T(2) distributions is not necessarily an easy alternative to finding T(1) distributions.

PERFIDI: parametrically enabled relaxation filters with double and multiple inversion.

We present a novel approach to the nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) analysis of complex samples with nontrivial distribution of longitudinal relaxation rate R(1). Parametrically enabled relaxation filters with double and multiple inversion (PERFIDI) aim to separate signals arising from components with different R(1) values prior to actual data acquisition. Given any standard NMR/MRI pulse sequence, which, by itself, is insensitive to differences in R(1) values, it can be combined with a PERFIDI preamble, which functions as a preliminary R(1) filter and confers on the original technique sensitivity to the dimension R(1).

Imaging inert fluorinated gases in cracks: perhaps in David's ankles.

Inspired by the challenge of determining the nature of cracks on the ankles of Michelangelo's statue David, we discovered that one can image SF(6) gas in cracks in marble samples with alacrity. The imaging method produces images of gas with a signal-to-noise ratio (SNR) of 100-250, which is very high for magnetic resonance imaging (MRI) in general, let alone for an image of a gas at thermal equilibrium polarization. To put this unusual SNR in better perspective, we imaged SF(6) in a crack in a marble sample and imaged the lung tissue of a live rat (a more familiar variety of sample to many MRI scientists) using the same pulse sequence, the same size coils and the same MRI system.

Nuclear magnetic resonance for cultural heritage.

Nuclear magnetic resonance (NMR) portable devices are now being used for nondestructive in situ analysis of water content, pore space structure and protective treatment performance in porous media in the field of cultural heritage. It is a standard procedure to invert T(1) and T(2) relaxation data of fully water-saturated samples to get "pore size" distributions, but the use of T(2) requires great caution. It is well known that dephasing effects due to water molecule diffusion in a magnetic field gradient can affect transverse relaxation data, even if the smallest experimentally available half echo time tau is used in Carr-Purcell-Meiboom-Gill experiments.