Publications by authors named "Giuseppe Mercurio"

10 Publications

  • Page 1 of 1

Direct observation of charge separation in an organic light harvesting system by femtosecond time-resolved XPS.

Nat Commun 2021 Feb 19;12(1):1196. Epub 2021 Feb 19.

Center for Free-Electron Laser Science/DESY, Hamburg, Germany.

The ultrafast dynamics of photon-to-charge conversion in an organic light-harvesting system is studied by femtosecond time-resolved X-ray photoemission spectroscopy (TR-XPS) at the free-electron laser FLASH. This novel experimental technique provides site-specific information about charge separation and enables the monitoring of free charge carrier generation dynamics on their natural timescale, here applied to the model donor-acceptor system CuPc:C. A previously unobserved channel for exciton dissociation into mobile charge carriers is identified, providing the first direct, real-time characterization of the timescale and efficiency of charge generation from low-energy charge-transfer states in an organic heterojunction. The findings give strong support to the emerging realization that charge separation even from energetically disfavored excitonic states is contributing significantly, indicating new options for light harvesting in organic heterojunctions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41467-021-21454-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7895929PMC
February 2021

Observation of fluctuation-mediated picosecond nucleation of a topological phase.

Nat Mater 2021 Jan 5;20(1):30-37. Epub 2020 Oct 5.

European XFEL, Schenefeld, Germany.

Topological states of matter exhibit fascinating physics combined with an intrinsic stability. A key challenge is the fast creation of topological phases, which requires massive reorientation of charge or spin degrees of freedom. Here we report the picosecond emergence of an extended topological phase that comprises many magnetic skyrmions. The nucleation of this phase, followed in real time via single-shot soft X-ray scattering after infrared laser excitation, is mediated by a transient topological fluctuation state. This state is enabled by the presence of a time-reversal symmetry-breaking perpendicular magnetic field and exists for less than 300 ps. Atomistic simulations indicate that the fluctuation state largely reduces the topological energy barrier and thereby enables the observed rapid and homogeneous nucleation of the skyrmion phase. These observations provide fundamental insights into the nature of topological phase transitions, and suggest a path towards ultrafast topological switching in a wide variety of materials through intermediate fluctuating states.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41563-020-00807-1DOI Listing
January 2021

Natural history of non-lethal Raine syndrome during childhood.

Orphanet J Rare Dis 2020 04 16;15(1):93. Epub 2020 Apr 16.

Department of Pediatrics, Vittore Buzzi Children's Hospital, Department of Biomedical and Clinical Science L. Sacco, Università degli Studi di Milano, Milan, Italy.

Background: Raine syndrome (RS) is a rare autosomal recessive disorder caused by biallelic loss-of-function mutations of FAM20C. The most common clinical features are microcephaly, exophthalmos, hypoplastic nose and severe midface hypoplasia, leading to choanal atresia. The radiological findings include generalized osteosclerosis and brain calcifications. RS is usually lethal during the neonatal period due to severe respiratory distress. However, there exists a non-lethal RS form, the phenotype of which is extremely heterogeneous. There is paucity of data about clinical course and life expectancy of these patients.

Results: This is the first description of follow-up features of non-lethal RS patients. Moreover, we present three unpublished cases. There are five Asian and two Arab patients. All were born to consanguineous parents. The most common neonatal comorbidity was respiratory distress secondary to choanal atresia. A variable degree of neurodevelopmental delay was seen in the majority of our cases and seizures and hearing or vision involvement were also frequent. Neurological and orthopedic issues were the most frequent complications seen at follow-up in our group. Persistent hypophosphatemic rickets was the most striking endocrinological manifestation, which was scarcely responsive to therapy with phosphate salts and alfacalcidol. Life expectancy of our patients goes beyond childhood, with the oldest of those described being 18 years old at present.

Conclusions: Manifestations of RS in those surviving the neonatal period are being increasingly recognized. Our study supports previous findings and provides clinical and biochemical observations and data from longer follow up. Finally, we propose multidisciplinary follow up for patients with non-lethal RS.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s13023-020-01373-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7164176PMC
April 2020

Publisher Correction: Seeded X-ray free-electron laser generating radiation with laser statistical properties.

Nat Commun 2019 Nov 13;10(1):5217. Epub 2019 Nov 13.

Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, D-22607, Hamburg, Germany.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41467-019-13249-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6853951PMC
November 2019

Seeded X-ray free-electron laser generating radiation with laser statistical properties.

Nat Commun 2018 10 29;9(1):4498. Epub 2018 Oct 29.

Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, D-22607, Hamburg, Germany.

The invention of optical lasers led to a revolution in the field of optics and to the creation of such fields of research as quantum optics. The reason was their unique statistical and coherence properties. The emerging, short-wavelength free-electron lasers (FELs) are sources of very bright coherent extreme-ultraviolet and X-ray radiation with pulse durations on the order of femtoseconds, and are presently considered to be laser sources at these energies. FELs are highly spatially coherent to the first-order but in spite of their name, behave statistically as chaotic sources. Here, we demonstrate experimentally, by combining Hanbury Brown and Twiss interferometry with spectral measurements that the seeded XUV FERMI FEL-2 source does indeed behave statistically as a laser. The results may be useful for quantum optics experiments and for the design and operation of next generation FEL sources.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41467-018-06743-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6206026PMC
October 2018

Diamine Oxidase Supplementation in Chronic Spontaneous Urticaria: A Randomized, Double-Blind Placebo-Controlled Study.

Int Arch Allergy Immunol 2018 26;176(3-4):268-271. Epub 2018 Apr 26.

Unit of Immunology, Rheumatology, Allergy and Rare Diseases, IRCCS Ospedale San Raffaele, Milan, Italy.

Introduction: Diamine oxidase (DAO) catabolizes and inactivates histamine, a key player in a wide range of invalidating conditions, such as migraine and chronic spontaneous urticaria (CSU). The highest expression of DAO occurs in the gastrointestinal tract, possibly to control the burden of histamine intake from food.

Methods: Here, we tested the hypothesis that a 30-day oral supplementation with DAO (1 capsule b.i.d., 15 min before a meal) could reduce the severity of CSU as estimated by the 7-Day Urticaria Activity Score (UAS-7). The study was designed as a double-blind, placebo-controlled, crossover investigation of 22 patients with CSU incompletely controlled by first-line antihistamine therapy.

Results: Twenty patients completed the study. Supplemental therapy with DAO caused a 3.8 ± 1.2 point mean ± SEM UAS-7 score reduction in patients with low serum DAO levels at time 0 (p = 0.041 compared to placebo). The degree of UAS-7 improvement was inversely correlated with the levels of basal DAO (p = 0.019). Patients receiving DAO supplementation were able to slightly reduce their daily antihistamine dose (p = 0.049).

Conclusion: These data suggest that DAO may be involved in the pathogenic cascade of CSU and that DAO supplementation could be effective for symptom relief in patients with low DAO levels in serum.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1159/000488142DOI Listing
July 2018

Chemical Bond Activation Observed with an X-ray Laser.

J Phys Chem Lett 2016 Sep 2;7(18):3647-51. Epub 2016 Sep 2.

DESY Photon Science , 22607 Hamburg, Germany.

The concept of bonding and antibonding orbitals is fundamental in chemistry. The population of those orbitals and the energetic difference between the two reflect the strength of the bonding interaction. Weakening the bond is expected to reduce this energetic splitting, but the transient character of bond-activation has so far prohibited direct experimental access. Here we apply time-resolved soft X-ray spectroscopy at a free-electron laser to directly observe the decreased bonding-antibonding splitting following bond-activation using an ultrashort optical laser pulse.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.jpclett.6b01543DOI Listing
September 2016

Molecular and structural changes induced by essential oils treatments in Vicia faba roots detected by genotoxicity testing.

J Toxicol Environ Health A 2016 25;79(4):143-52. Epub 2016 Feb 25.

d Laboratory of Chemometrics and Environmental Applications (ISPRA) , Rome , Italy.

Over the last few years, there has been an increased interest in exploiting allelopathy in organic agriculture. The aim of this investigation was to examine the effects of essential oil mixtures in order to establish their allelopathic use in agriculture. Two mixtures of essential oils consisting respectively of tea tree oil (TTO) and clove plus rosemary (C + R) oils were tested. Phytotoxicity and genotoxicity tests on the root meristems of Vicia faba minor were performed. A phytotoxic influence was particularly relevant for C + R mixture, while genotoxicity tests revealed significant results with both C + R oil mixture and TTO. Phenotypic analysis on Vicia faba minor primary roots following C + R oil mixture treatment resulted in callose production, an early symptom attributed to lipid peroxidation. The approach described in this study, based on genotoxicity bioassays, might identify specific DNA damage induced by essential oil treatments. These tests may represent a powerful method to evaluate potential adverse effects of different mixtures of essential oils that might be useful in alternative agriculture. Future studies are focusing on the positive synergism of more complex mixtures of essential oils in order to reduce concentrations of potentially toxic components while at the same time maintaining efficacy in antimicrobial and antifungal management.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/15287394.2015.1124059DOI Listing
August 2016

Evaluation of autonomies in the severely brain injured: the Progression of Autonomies Scale.

Funct Neurol 2013 Jan-Mar;28(1):29-38

Research in Advanced Neurorehabilitation, S.Anna Institute, Crotone, Italy.

The aim of this study was to validate the Progression of Autonomies Scale (PAS) for the evaluation of autonomies in severe acquired brain injury patients. The PAS design is based on a model of progressive recovery of autonomies and is organized in three domains (Personal, Domestic and Extra-domestic). Scores assigned range from zero to three. The PAS items gather information about the patient's perception and awareness of his/her disability(ies) on admission and perception of his/her improvement at the end of a rehabilitation process. The PAS was administered to 127 inpatients on admission to and at discharge from a rehabilitation program. All 127 inpatients, recruited in a prospective multicenter study, completed the rehabilitation program. The statistical analysis identified a total of 38 items to be retained in the PAS, out of an initial 82 items. The results provide evidence of the validity and reliability of the PAS in its final version.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3812722PMC
August 2013

Residual risk of HIV-1 transmission: the case of a seroconverter.

Clin Lab 2002 ;48(5-6):283-6

National Blood Transfusion Centre, Italian Red Cross, Rome.

In the present report we describe the case of a repeat blood donor infected with HIV-1. In January 2000 the donor was found to be repeatedly reactive to HIV1/2 antibodies and HIV-1 RNA screening tests. The donation was confirmed to be HIV-1 positive by Western blot. During the post-test counselling session, the donor reported a risk sexual behaviour denied during the pre-donation interview, and he recalled that in May 1998 he had undergone a check-up including the test for the detection of HIV1/2 antibodies, which was negative. This check-up was dated four months the next to the donor's previous donation in January 1998, which had been found HIV1/2 antibody negative, too. Serum and plasma specimens, properly stored at -80 degrees C, were available at the hospital where the donor had undergone the HIV antibody test in May 1998. Thus, the specimens dated May 1998 and the specimen of the last donation in January 2000 were investigated again by using the most sensitive tests currently available in the setting of donation screening. On the whole, the results suggest that in May 1998 the donor was in the pre-seroconversion period for HIV-1 infection. The case reported here stresses that a residual risk for HIV transmission through blood products still relies on the possibility that an individual may be accepted as blood donor during the asymptomatic pre-seroconversion window period of HIV-1 infection. Actually, this phase of the infection cannot be detected by the routine antibody/antigen-based HIV1/2 screening tests but only by using more sensitive techniques such as genomic screening.
View Article and Find Full Text PDF

Download full-text PDF

Source
January 2003
-->