The Dimorphos ejecta plume properties revealed by LICIACube.

The Double Asteroid Redirection Test (DART) had an impact with Dimorphos (a satellite of the asteroid Didymos) on 26 September 20221. Ground-based observations showed that the Didymos system brightened by a factor of 8.3 after the impact because of ejecta, returning to the pre-impact brightness 23.7 days afterwards2. Hubble Space Telescope observations made from 15 minutes after impact to 18.5 days after, with a spatial resolution of 2.1 kilometres per pixel, showed a complex evolution of the ejecta3, consistent with other asteroid impact events. The momentum enhancement factor, determined using the measured binary period change4, ranges between 2.2 and 4.9, depending on the assumptions about the mass and density of Dimorphos5. Here we report observations from the LUKE and LEIA instruments on the LICIACube cube satellite, which was deployed 15 days in advance of the impact of DART. Data were taken from 71 seconds before the impact until 320 seconds afterwards. The ejecta plume was a cone with an aperture angle of 140 ± 4 degrees. The inner region of the plume was blue, becoming redder with increasing distance from Dimorphos. The ejecta plume exhibited a complex and inhomogeneous structure, characterized by filaments, dust grains and single or clustered boulders. The ejecta velocities ranged from a few tens of metres per second to about 500 metres per second.

A comprehensive review of healthy effects of vegetarian diets.

AIMS: A comprehensive review comparing the effect of vegetarian (V) and non-vegetarian (NV) diets on the major cardiometabolic diseases' outcomes was performed. DATA SYNTHESIS: We performed literature research (up to December 31, 2022) of the evidence separately for vascular disease (VD), obesity (OB), dyslipidemia (Dysl), hypertension (HPT), type 2 diabetes (T2D), metabolic syndrome (MetS), analyzing only cohort studies and randomized controlled studies (RCTs) and comparing the effect of V and NV diets. Cohort studies showed advantages of V diets compared to NV diets on incidence and/or mortality risk for ischemic heart disease, overweight and OB risk. Most cohort studies showed V had lower risk of HPT and lower blood pressure (BP) than NV and V diets had positive effects on T2D risk or plasma parameters. The few cohort studies on the risk of MetS reported mixed results. In RCTs, V diets, mainly low-fat-vegan ones, led to greater weight loss and improved glycemic control than NV diets and in the only one RCT a partial regression of coronary atherosclerosis. In most RCTs, V diets significantly reduced LDL-C levels (but also decreased HDL-C levels) and BP. CONCLUSIONS: In this comprehensive review of the association between V diets and cardiometabolic outcomes, we found that following this type of diet may help to prevent most of these diseases. However, the non-uniformity of the studies, due to ethnic, cultural, and methodological differences, does not allow for generalizing the present results and drawing definitive conclusions. Further, well-designed studies are warranted to confirm the consistency of our conclusions.

Position paper on vegetarian diets from the working group of the Italian Society of Human Nutrition.

BACKGROUND: Interest in vegetarian diets is growing in Italy and elsewhere, as government agencies and health/nutrition organizations are emphasizing that regular consumption of plant foods may provide health benefits and help prevent certain diseases. METHODS AND RESULTS: We conducted a Pubmed search, up to September, 2015, for studies on key nutrients (proteins, vitamin B12, iron, zinc, calcium, vitamin D, and n-3 fatty acids) in vegetarian diets. From 295 eligible publications the following emerged: Vegetarians should be encouraged to supplement their diets with a reliable source of vitamin B12 (vitamin-fortified foods or supplements). Since the plant protein digestibility is lower than that of animal proteins it may be appropriate for vegetarians to consume more proteins than recommended for the general population. Vegetarians should also be encouraged to habitually consume good sources of calcium, iron and zinc - particularly vegetables that are low in oxalate and phytate (e.g. Brassicaceae), nuts and seeds, and calcium-rich mineral water. Calcium, iron, and zinc bioavailability can be improved by soaking, germination, and sour-dough leavening that lower the phytate content of pulses and cereals. Vegetarians can ensure good n-3 fatty acid status by habitually consuming good sources of a-linolenic acid (walnuts, flaxseeds, chia seeds, and their oils) and limiting linoleic acid intake (corn and sunflower oils). CONCLUSIONS: Well-planned vegetarian diets that include a wide variety of plant foods, and a reliable source of vitamin B12, provide adequate nutrient intake. Government agencies and health/nutrition organizations should provide more educational resources to help Italians consume nutritionally adequate vegetarian diets.

Identification of a serum-detectable metabolomic fingerprint potentially correlated with the presence of micrometastatic disease in early breast cancer patients at varying risks of disease relapse by traditional prognostic methods.

BACKGROUND: Prognostic tools in early breast cancer are inadequate. The evolving field of metabolomics may allow more accurate identification of patients with residual micrometastases. PATIENTS AND METHODS: Forty-four early breast cancer patients with pre- and postoperative serum samples had metabolomic assessment by nuclear magnetic resonance. Fifty-one metastatic patients served as control. Differential clustering was identified and used to calculate individual early patient 'metabolomic risk', calculated as inverse distance of each early patient from the metastatic cluster barycenter. Metabolomic risk was compared with Adjuvantionline 10-year mortality assessment. RESULTS: Innate serum metabolomic differences exist between early and metastatic patients. Preoperative patients were identified with 75% sensitivity, 69% specificity and 72% predictive accuracy. Comparison with Adjuvantionline revealed discordance. Of 21 patients assessed as high risk by Adjuvantionline, 10 (48%) and 6 (29%) were at high risk by metabolomics in pre- and postoperative settings, respectively. Of 23 low-risk patients by Adjuvantionline, 11 (48%) preoperative and 20 (87%) postoperative patients were at low risk by metabolomics. CONCLUSIONS: This study identifies metabolomic discrimination between early and metastatic breast cancer. Micrometastatic disease may account for metabolomic misclassification of some early patients as metastatic. Metabolomics identifies more patients as low relapse risk compared with Adjuvantionline. Further exploration of this metabolomic fingerprint is warranted.

Surface changes on comet 67P/Churyumov-Gerasimenko suggest a more active past.

The Rosetta spacecraft spent ~2 years orbiting comet 67P/Churyumov-Gerasimenko, most of it at distances that allowed surface characterization and monitoring at submeter scales. From December 2014 to June 2016, numerous localized changes were observed, which we attribute to cometary-specific weathering, erosion, and transient events driven by exposure to sunlight and other processes. While the localized changes suggest compositional or physical heterogeneity, their scale has not resulted in substantial alterations to the comet's landscape. This suggests that most of the major landforms were created early in the comet's current orbital configuration. They may even date from earlier if the comet had a larger volatile inventory, particularly of CO or CO2 ices, or contained amorphous ice, which could have triggered activity at greater distances from the Sun.

Rosetta's comet 67P/Churyumov-Gerasimenko sheds its dusty mantle to reveal its icy nature.

The Rosetta spacecraft has investigated comet 67P/Churyumov-Gerasimenko from large heliocentric distances to its perihelion passage and beyond. We trace the seasonal and diurnal evolution of the colors of the 67P nucleus, finding changes driven by sublimation and recondensation of water ice. The whole nucleus became relatively bluer near perihelion, as increasing activity removed the surface dust, implying that water ice is widespread underneath the surface. We identified large (1500 square meters) ice-rich patches appearing and then vanishing in about 10 days, indicating small-scale heterogeneities on the nucleus. Thin frosts sublimating in a few minutes are observed close to receding shadows, and rapid variations in color are seen on extended areas close to the terminator. These cyclic processes are widespread and lead to continuously, slightly varying surface properties.

Interaction of cobalt-bovine carbonic anhydrase with the acetate ion.

The visible spectra of solutions of cobalt(II) bovine carbonic anhydrase (carbonate hydro-lyase, EC 4.2.1.1) with increasing amounts of acetate have allowed the determination of the apparent inhibition constants and of the extrapolated limit spectra of the completely bound enzyme. The electronic spectra have been interpreted on the basis of the presence of five coordinate adduct species. 13C and 1H NMR spectra have also been recorded and discussed on the basis of the metal enzyme-acetate type of interactions. Titrations by means of NMR spectroscopy of the acetate-cobalt(II) bovine carbonic anhydrase with p-toluenesulfonamide and azide indicate the existence of two binding sites for the acetate group.

An ENDOR study of human and bovine erythrocyte superoxide dismutase: 1H and 14N interactions.

Hyperfine interactions (1H and 14N) with the paramagnetic Cu(II)-site obtained from frozen solutions of human and bovine erythrocyte superoxide dismutase (superoxide:superoxide oxidoreductase, EC 1.15.1.1) as well as from their derivatives produced by anion binding (N3-, CN-) and by depletion of the Zn(II) site were studied using electron nuclear double resonance (ENDOR) spectroscopy at about 15 K. Both interactions were found to be identical in human and bovine erythrocyte superoxide dismutase. In all compounds, an anisotropic, exchangeable 1H interaction with a nearly constant coupling value (approximately 3 MHz along g perpendicular ) was observed which is due to either histidine NH- or water protons. Other proton interactions were tentatively assigned to H beta 1 of His-44, H delta 2 of His-46 and to H beta 2 of His-44. Depletion of the Zn(II) site did not alter appreciably the pattern of the proton interactions. The 14N couplings of the native specimen indicated equivalent coordination, whereas Zn(II) depletion and CN- addition were found to produce either some or drastic inequivalences, respectively. For N3- addition to either the native or the Zn(II)-depleted sample only minor effects on the respective 14N coupling pattern were observed.

New applications of paramagnetic NMR in chemical biology.

The methodological accessibility to solution structure and dynamic investigation of paramagnetic metallobiomolecules has afforded the ability to tackle the redox pairs of electron transfer proteins of which at least one is paramagnetic, to study the orientation effects of high magnetic fields on paramagnetic biomolecules, and finally to study the role of metal-based cofactors in protein folding and stability.

Crystal structure of the catalytic domain of human matrix metalloproteinase 10.

The catalytic domain of matrix metalloproteinase-10 (MMP-10) has been expressed in Escherichia coli and its crystal structure solved at 2.1 A resolution. The availability of this structure allowed us to critically examine the small differences existing between the catalytic domains of MMP-3 and MMP-10, which show the highest sequence identity among all MMPs. Furthermore, the binding mode of N-isobutyl-N-[4-methoxyphenylsulfonyl]glycyl hydroxamic acid (NNGH), which is one of the most known commercial inhibitors of MMPs, is described for the first time.

The crystal structure of the monomeric human SOD mutant F50E/G51E/E133Q at atomic resolution. The enzyme mechanism revisited.

The crystal structure of the engineered monomeric human Cu,ZnSOD triple mutant F50E/G51E/E133Q (Q133M2SOD) is reported at atomic resolution (1.02 A). This derivative has about 20 % of the wild-type activity. Crystals of Q133M2SOD have been obtained in the presence of CdCl2. The metal binding site is disordered, with both cadmium and copper ions simultaneously binding to the copper site. The cadmium (II) ions occupy about 45 % of the copper sites by binding the four histidine residues which ligate copper in the native enzyme, and two further water molecules to complete octahedral coordination. The copper ion is tri-coordinate, and the fourth histidine (His63) is detached from copper and bridges cadmium and zinc. X-ray absorption spectroscopy performed on the crystals suggests that the copper ion has undergone partial photoreduction upon exposure to the synchrotron light. The structure is also disordered in the disulfide bridge region of loop IV that is located at the subunit/subunit interface in the native SOD dimer. As a consequence, the catalytically relevant Arg143 residue is disordered. The present structure has been compared to other X-ray structures on various isoenzymes and to the solution structure of the same monomeric form. The structural results suggest that the low activity of monomeric SOD is due to the disorder in the conformation of the side-chain of Arg143 as well as of loop IV. It is proposed that the subunit-subunit interactions in the multimeric forms of the enzyme are needed to stabilize the correct geometry of the cavity and the optimal orientation of the charged residues in the active channel. Furthermore, the different coordination of cadmium and copper ions, contemporaneously present in the same site, are taken as models for the oxidized and reduced copper species, respectively. These properties of the structure have allowed us to revisit the enzymatic mechanism.

pH-dependent equilibria of yeast Met80Ala-iso-1-cytochrome c probed by NMR spectroscopy: a comparison with the wild-type protein.

BACKGROUND: Cytochrome c has five distinct pH-dependent conformational states, including two alkaline forms of unknown structure. It is believed that in both of the alkaline forms a Lys residue is ligated to the heme, but the identity of the Lys residue is different. Exchange between these forms would require extensive structural rearrangement. Mutation of the heme axial ligand (Met80) to Ala in Saccharomyces cerevisiae iso-1-cytochrome c yields a protein (Ala80cyt c) capable of binding exogenous ligands such as dioxygen and cyanide. We have analyzed the 1H NMR spectra of this mutant at various pH values in the hope of gaining insight into the structure of the acidic and alkaline forms of native cytochrome c. RESULTS: The pH dependence of the 1H NMR spectrum of ferriAla80cyt c is consistent with the high-spin/low-spin transition (pKa = 6.5) observed by absorption spectroscopy. The T1 values for the low-spin form are consistent with OH ligation, as inferred previously from absorption and electron paramagnetic resonance spectroscopic results. The pH-dependent equilibria of ferriAla80cyt c differ from those of the wild-type protein. Both Ala80 and wild-type ferricyt c appear to have the same iron coordination at low pH (approximately equal to 2), while only one alkaline form of Ala80cyt c (versus two for WTcyt c) was detected. CONCLUSIONS: The differences between the pH dependence of the 1H NMR spectra of Ala80cyt c and those of the wild-type protein demonstrate that the heme axial ligands influence the relative energies of the conformational states of cytochrome c. The results are consistent with the notion that a large rearrangement is required to switch between the two alkaline forms.

[Public food service in Milan city and Hinterland: GMP application (Part 1)]. / Ristorazione pubblica: indagine campionaria in due AASSLL dell'area milanese. Nota 1: Applicazione dell'autocontrollo.

Food service establishments are recognized as a critical sector concerning foodborne diseases occurrence, that is associated to contributing factors such as the anticipated preparation of meals that are often highly handled, and long-time distributed. A survey has been planned to evaluate the application of HACCP plan, in order to select a statistically representative sample of food services (restaurant, pizza-shop, bar, ..) in two Milan area' Public Health Units (PHU). During the inspections a proper check-list has been filled up in order to give a conformity evaluation about the global situation and about three specific sections: hygiene of food-handlers, procedures control, temperatures management. The food services have been found satisfactory in 9/106 and 5/54 cases in Milan City and in hinterland, respectively; among the two areas, highly significant differences have been revealed about temperatures management (68% and 28% unsatisfactory, respectively). In Milan City restaurants provided with HACCP plan scores are significantly different from unprovided restaurants scores (global and the three sections' evaluation); in Milan hinterland differences between provided and unprovided HACCP plan restaurants regard temperature management scores only. Useful suggestions to improve the quality of surveillance activity come from complex and heterogeneous findings shown in this study.

[Public food service in Milan city and Hinterland: food-handlers training level (Part 2)]. / Ristorazione pubblica: indagine campionaria in due AASSLL dell'area milanese. Nota 2: Grado di preparazione del personale.

The prevention and control of foodborne diseases play an important role in public health and the responsibility of food-handlers is of great concern: their training on food safety is particularly required in the critical sector of public food service establishments. The food-handlers knowledge has been evaluated by a questionnaire filled up in two Public Health Units (PHU) in Milan City and Milan hinterland. Only 11.5% of food-handlers turned at to be good trained; the wrong answers are concentrated on the section titled "temperatures management" (68 and 59% in Milan City and in Milan hinterland, respectively). Only for 31.4% of food-handlers the attendance to training courses is well documented, although the knowledge level seems to be partially influenced by training activity: exclusively in Milan City food-handlers an highly significant difference has been found among "trained" and "no-trained" workers in correct answers about temperatures management (p= 0.0046). The frequency of exact answers isn't associated to the satisfaction level revealed during inspection of restaurants. Focusing the attention on the insufficient efficacy of training courses and the lacking connection between knowledge and behaviour, a critical revision of training activity quality seems to be necessary. In future some professional training activities in the field should be promoted.

Aliphatic and aromatic inhibitors binding to the active site of catechol 2,3-dioxygenase from Pseudomonas putida mt-2.

The interaction of different classes of inhibitors with the extradiol cleaving catechol 2,3-dioxygenase from Pseudomonas putida mt-2 was monitored by longitudinal and transverse proton relaxation measurements as well as by kinetic activity studies in order to characterize the type of interaction of such inhibitors with the active site of the enzyme. The average distances of the inhibitors from the catalytic iron(II) ion have been estimated from the 1H longitudinal relaxation rates. Phenols and aliphatic ketones appear to be coordinated to the iron(II) ion in the active site.

Transient versus steady state NOE in paramagnetic molecules Cu2Co2SOD as an example.

Truncated, steady state and transient NOE experiments have been performed on bovine Cu2Co2 superoxide dismutase. The effectiveness of the different NOE experiments in the general case of paramagnetic macromolecules is discussed. It is concluded that steady state NOEs give superior results. The validity of the two spins approximation is discussed, and NOE values for a fully coupled set of nuclei have been calculated. Transient NOE experiments, when properly performed, confirm the previous assignment of the hyperfine shifted signals in Cu2Co2SOD based on steady state NOE measurements [(1989) Inorg. Chem. 28, 4650] and eliminate any further reason for controversy on an important issue as the assignment of the 1H NMR signals of protons of metal-coordinated imidazoles.

Substrate, substrate analogue, and inhibitor interactions with the ferrous active site of catechol 2,3-dioxygenase monitored through XAS studies.

The interactions of catechol (substrate), 2-hydroxy-pyridine-N-oxide (substrate analogue), and 2-bromophenol (inhibitor) with the extradiol cleaving catechol-2,3-dioxygenase from Pseudomonas putida mt-2 have been monitored through X-ray absorption spectroscopy (XAS). The analysis of the data provides details about the mode of coordination of the substrate and of the inhibitors to the active site of the enzyme.

Selective interaction of ferricyanide with cluster I of Clostridium pasteurianum 2[Fe4S4] ferredoxin.

Treatment of Clostridium pasteurianum ferredoxin (CpFd) with stoichiometric amounts of potassium ferricyanide results in the specific conversion of cluster I into a Fe3S4+ species while leaving cluster II unaltered. Ferricyanide-treated CpFd derivative has been purified and characterized through biochemical and spectroscopical techniques. The cluster conversion process is reversible and reconstitution of native CpFd has been afforded under appropriate conditions.

ePHOGSY experiments on a paramagnetic protein: location of the catalytic water molecule in the heme crevice of the oxidized form of horse heart cytochrome c.

The hydration properties of the oxidized form of horse heart cytochrome c have been studied by 1H NMR spectroscopy. Application of ePHOGSY (enhanced protein hydration observed through gradient spectroscopy) experiments over a paramagnetic molecule provided firm spectroscopic evidence of the presence of a water molecule in the heme crevice. A few intermolecular NOEs have been used to locate the water molecule at about 0.65 nm away from the iron atom and to compare the position observed in solution with that observed in the crystal structure and in solution for the reduced state. The resulting picture is that there is a detectable movement of the water molecule upon oxidation.

The D13C variant of Bacillus schlegelii 7Fe ferredoxin is an 8Fe ferredoxin as revealed by 1H-NMR spectroscopy.

The N-terminal cluster binding motif Cys8XXXXXXXCys16....Cys49 of Bacillus schlegelii 7Fe ferredoxin, which provides the ligands to the [Fe3S4]+ cluster, was modified by the mutation Asp13 --> Cys. The mutant D13C is expressed in Escherichia coli as an 8Fe ferredoxin, with NMR properties similar to those of clostridial-type ferredoxins. The full assignment of the hyperfine shifted resonances indicates that Cys13 serves as ligand to the new fourth iron atom in the N-terminal cluster despite the atypical binding sequence CysXXXXCysXXCys....Cys. The C alpha-C beta-S-Fe dihedral angles of all cysteine ligands to the two [Fe4S4]2+ clusters of the D13C variant are similar to those observed in other 8Fe and 4Fe ferredoxins.