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1.
Cell Mol Life Sci ; 76(19): 3723-3744, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31147752

RESUMO

Starting from their role exerted on osteoblast and osteoclast differentiation and activity pathways, microRNAs (miRNAs) have been recently identified as regulators of different processes in bone homeostasis. For this purpose, in a recent review, we highlighted, as deregulated miRNAs could be involved in different bone diseases such as osteoporosis. In addition, recent studies supported the concept that osteoporosis-induced bone alterations might offer a receptive site for cancer cells to form bone metastases, However, to date, no data on specific-shared miRNAs between osteoporosis and bone metastases have been considered and described to clarify the evidence of this link. The main goal of this review is to underline as deregulated miRNAs in osteoporosis may have specific roles in the development of bone metastases. The review showed that several circulating osteoporotic miRNAs could facilitate tumor progression and bone-metastasis formation in several tumor types, i.e., breast cancer, prostate cancer, non-small-cell lung cancer, esophageal squamous cell carcinoma, and multiple myeloma. In detail, serum up-regulation of pro-osteoporotic miRNAs, as well as serum down-regulation of anti-osteoporotic miRNAs are common features of all these tumors and are able to promote bone metastasis. These results are of key importance and could help researcher and clinicians to establish new therapeutic strategies connected with deregulation of circulating miRNAs and able to interfere with pathogenic processes of osteoporosis, tumor progressions, and bone-metastasis formation.


Assuntos
Neoplasias Ósseas/secundário , MicroRNA Circulante/metabolismo , Osteoporose/genética , Animais , Neoplasias Ósseas/complicações , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/secundário , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/patologia , Carcinoma de Células Escamosas do Esôfago/genética , Carcinoma de Células Escamosas do Esôfago/secundário , Feminino , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Masculino , MicroRNAs/metabolismo , Mieloma Múltiplo/genética , Osteoporose/complicações , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia
2.
Cell Mol Life Sci ; 75(4): 649-667, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28864934

RESUMO

Gene therapy might represent a promising strategy for chondral and osteochondral defects repair by balancing the management of temporary joint mechanical incompetence with altered metabolic and inflammatory homeostasis. This review analysed preclinical and clinical studies on gene therapy for the repair of articular cartilage defects performed over the last 10 years, focussing on expression vectors (non-viral and viral), type of genes delivered and gene therapy procedures (direct or indirect). Plasmids (non-viral expression vectors) and adenovirus (viral vectors) were the most employed vectors in preclinical studies. Genes delivered encoded mainly for growth factors, followed by transcription factors, anti-inflammatory cytokines and, less frequently, by cell signalling proteins, matrix proteins and receptors. Direct injection of the expression vector was used less than indirect injection of cells, with or without scaffolds, transduced with genes of interest and then implanted into the lesion site. Clinical trials (phases I, II or III) on safety, biological activity, efficacy, toxicity or bio-distribution employed adenovirus viral vectors to deliver growth factors or anti-inflammatory cytokines, for the treatment of osteoarthritis or degenerative arthritis, and tumour necrosis factor receptor or interferon for the treatment of inflammatory arthritis.


Assuntos
Cartilagem Articular/fisiologia , Condrócitos/fisiologia , Terapia Genética , Osteoartrite/terapia , Regeneração/genética , Animais , Regeneração Óssea/genética , Cartilagem Articular/patologia , Terapia Genética/métodos , Terapia Genética/tendências , Humanos
3.
Phys Rev Lett ; 120(26): 263901, 2018 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-30004768

RESUMO

The extension of nonlinear optical techniques to the extreme-ultraviolet (EUV), soft and hard x-ray regime represents one of the open challenges of modern science since it would combine chemical specificity with background-free detection and ultrafast time resolution. We report on the first observation of a four-wave-mixing (FWM) response from solid-state samples stimulated exclusively by EUV pulses. The all-EUV FWM signal was generated by the diffraction of high-order harmonics of the FERMI free-electron laser (FEL) from the standing wave resulting from the interference of two crossed FEL pulses at the fundamental wavelength. From the intensity of the FWM signal, we are able to extract the first-ever estimate of an effective value of ∼6×10^{-24} m^{2} V^{-2} for the third-order nonlinear susceptibility in the EUV regime. This proof of principle experiment represents a significant advance in the field of nonlinear optics and sets the starting point for a manifold of techniques, including frequency and phase-resolved FWM methods, that are unprecedented in this photon-energy regime.

4.
Biochim Biophys Acta Gen Subj ; 1862(9): 1893-1901, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29885361

RESUMO

BACKGROUND: Exosomes are nanovesicles actively secreted by potentially all cell types, including tumour cells, with the primary role of extracellular systemic communication mediators, both at autocrine and paracrine levels, at short and long distances. Recently, different studies have used exosomes as a delivery system for a plethora of different molecules, such as drugs, microRNAs and proteins. This has been made possible thanks to the simplicity in exosomes engineering, their great stability and versatility for applications in oncology as well as in regenerative medicine. SCOPE OF REVIEW: The aim of this review is to provide information on the state-of-the-art and possible applications of engineered exosomes, both for cargo and specific cell-targeting, in different pathologies related to the musculoskeletal system. MAJOR CONCLUSIONS: The use of exosomes as therapeutic agents is rapidly evolving, different studies explore drug delivery with exosomes using different molecules, showing an enormous potential in various research fields such as oncology and regenerative medicine. GENERAL SIGNIFICANCE: However, despite the significant progress made by the different studies carried out, currently, the use of exosomes is not a therapeutic reality for the considerable difficulties to overcome.


Assuntos
Exossomos/metabolismo , Doenças Musculoesqueléticas/terapia , Medicina Regenerativa , Animais , Sistemas de Liberação de Medicamentos , Exossomos/genética , Humanos , Doenças Musculoesqueléticas/genética , Doenças Musculoesqueléticas/patologia
5.
Faraday Discuss ; 194: 283-303, 2016 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-27711831

RESUMO

The development of free electron laser (FEL) sources has provided an unprecedented bridge between the scientific communities working with ultrafast lasers and extreme ultraviolet (XUV) and X-ray radiation. Indeed, in recent years an increasing number of FEL-based applications have exploited methods and concepts typical of advanced optical approaches. In this context, we recently used a seeded FEL to demonstrate a four-wave-mixing (FWM) process stimulated by coherent XUV radiation, namely the XUV transient grating (X-TG). We hereby report on X-TG measurements carried out on a sample of silicon nitride (Si3N4). The recorded data bears evidence for two distinct signal decay mechanisms: one occurring on a sub-ps timescale and one following slower dynamics extending throughout and beyond the probed timescale range (100 ps). The latter is compatible with a slower relaxation (time decay > ns), that may be interpreted as the signature of thermal diffusion modes. From the peak intensity of the X-TG signal we could estimate a value of the effective third-order susceptibility which is substantially larger than that found in SiO2, so far the only sample with available X-TG data. Furthermore, the intensity of the time-coincidence peak shows a linear dependence on the intensity of the three input beams, indicating that the measurements were performed in the weak field regime. However, the timescale of the ultrafast relaxation exhibits a dependence on the intensity of the XUV radiation. We interpreted the observed behaviour as the generation of a population grating of free-electrons and holes that, on the sub-ps timescale, relaxes to generate lattice excitations. The background free detection inherent to the X-TG approach allowed the determination of FEL-induced electron dynamics with a sensitivity largely exceeding that of transient reflectivity and transmissivity measurements, usually employed for this purpose.

6.
Nutr Metab Cardiovasc Dis ; 26(12): 1071-1078, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27776917

RESUMO

BACKGROUND: The results of the EMPA-REG-OUTCOME trial on type 2 diabetic patients at high risk for prior cardiovascular events showed that empagliflozin produces a remarkable reduction in the rates of hospitalization for heart failure (35%), cardiovascular death (38%), and all-cause death (32%). This unexpected cardio-protective action cannot be accounted for by the improvement of "classical" cardiovascular risk factors. AIMS: This review aims at summarizing current knowledge on the cardiovascular action of SGLT2 inhibitors and discuss the different hypotheses formulated to explain the results of the EMPA-REG-OUTCOME-study. DATA SYNTHESIS: We discuss in detail the major cardiovascular outcomes of the study in the light of the potential systemic and myocardial mechanisms of action of the drug. In addition, we propose and speculate on a direct effect of empagliflozin on cardiomyocytes. CONCLUSIONS: The available evidence is insufficient to establish any of the proposed mechanisms of cardiovascular action of empagliflozin. While awaiting for the results of ongoing clinical studies with other SGLT2 inhibitors, the most promising putative mechanisms still deserve to be confirmed with specifically designed, yet unavailable, pre-clinical studies.


Assuntos
Compostos Benzidrílicos/uso terapêutico , Doenças Cardiovasculares/prevenção & controle , Diabetes Mellitus Tipo 2/tratamento farmacológico , Glucosídeos/uso terapêutico , Coração/fisiopatologia , Hipoglicemiantes/uso terapêutico , Rim/efeitos dos fármacos , Miócitos Cardíacos/efeitos dos fármacos , Inibidores do Transportador 2 de Sódio-Glicose , Animais , Compostos Benzidrílicos/efeitos adversos , Doenças Cardiovasculares/mortalidade , Doenças Cardiovasculares/fisiopatologia , Ensaios Clínicos como Assunto , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/mortalidade , Diabetes Mellitus Tipo 2/fisiopatologia , Glucosídeos/efeitos adversos , Humanos , Hipoglicemiantes/efeitos adversos , Rim/metabolismo , Rim/fisiopatologia , Miócitos Cardíacos/metabolismo , Medição de Risco , Fatores de Risco , Transportador 2 de Glucose-Sódio/metabolismo , Fatores de Tempo , Resultado do Tratamento
7.
J Synchrotron Radiat ; 22(3): 485-91, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25931057

RESUMO

FERMI is a seeded free-electron laser (FEL) facility located at the Elettra laboratory in Trieste, Italy, and is now in user operation with its first FEL line, FEL-1, covering the wavelength range between 100 and 20 nm. The second FEL line, FEL-2, a high-gain harmonic generation double-stage cascade covering the wavelength range 20-4 nm, has also completed commissioning and the first user call has been recently opened. An overview of the typical operating modes of the facility is presented.

8.
Phys Rev Lett ; 113(24): 247202, 2014 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-25541801

RESUMO

Thin film magnetization reversal without applying external fields is an attractive perspective for applications in sensors and devices. One way to accomplish it is by fine-tuning the microstructure of a magnetic substrate via temperature control, as in the case of a thin Fe layer deposited on a MnAs/GaAs(001) template. This work reports a time-resolved resonant scattering study exploring the magnetic and structural properties of the Fe/MnAs system, using a 100 fs optical laser pulse to trigger local temperature variations and a 100 fs x-ray free-electron laser pulse to probe the induced magnetic and structural dynamics. The experiment provides direct evidence that a single optical laser pulse can reverse the Fe magnetization locally. It reveals that the time scale of the magnetization reversal is slower than that of the MnAs structural transformations triggered by the optical pulse, which take place after a few picoseconds already.

9.
Clin Ter ; 172(4): 260-263, 2021 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-34247206

RESUMO

ABSTRACT: Nasopharyngeal carcinoma, one of the most common head and neck cancers in Southeast Asia, is uncommon in Western countries and it is frequently diagnosed in advanced stage. Chemotherapy given with radiation therapy, followed by more chemotherapy, is the standard of care of stage IV nasopharyngeal carcinoma but Cetuximab, an epidermal growth factor (EGFR) inhibitor, is now making its way in the treatment of locoregionally advanced nasopharyngeal carcinoma. We report a case of 58 years old patient with metastatic nasopharyngeal carcinoma with an astonishing response to Cetuximab. At the time of writing, the patient is still in treatment with Cetuximab with excellent disease control.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Cetuximab/uso terapêutico , Cisplatino/uso terapêutico , Fluoruracila/uso terapêutico , Carcinoma Nasofaríngeo/tratamento farmacológico , Neoplasias Nasofaríngeas/tratamento farmacológico , Metástase Neoplásica/tratamento farmacológico , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
10.
Clin Ter ; 171(1): e63-e66, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33346331

RESUMO

Having regard to the increasing attention to the issue of safety and health of patients and workers by low, the hypothesis that this topic will be the growing trend in the next years does not seem to be manifestly unfounded. For this reason, it is wise for healthcare professionals to already be aware that any violation of the interests underlying the legislation in question entails a ruling on civil and/or criminal liability. It is therefore necessary to identify the most suitable means to prevent undue harm occurring, partly to exempt healthcare professionals and hospitals from compensation costs, thereby providing them with recourse to insurance coverage. Healthcare facility organisations must adopt Risk Management techniques as a tool to simultaneously guarantee the effectiveness of health services (in this case), the efficiency of the management economy, and finally compliance with all legally required precautions. This will relegate the occurrence of an adverse event to remote and unpredictable hypotheses, thus guaranteeing useful recourse to insurance coverage to compensate any harm that does occur.


Assuntos
Atenção à Saúde/organização & administração , Responsabilidade Legal , Gestão de Riscos/organização & administração , Compensação e Reparação , Atenção à Saúde/legislação & jurisprudência , Atenção à Saúde/normas , Pessoal de Saúde , Humanos , Gestão de Riscos/legislação & jurisprudência
11.
Clin Ter ; 172(5): 484-488, 2021 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-34625782

RESUMO

ABSTRACT: Gelli-Bianco law (Law no. 24/2017) intervenes both in order to divide healthcare liability between the healthcare professional and the facility in which he/she exercises and to incentivize the latter to adopt an organizational model suitable for managing the risk associated with the provision of any healthcare service, including the information for consent. In fact, the healthcare facility must guarantee clear, complete and adequate information on the specific case, which, therefore, cannot consist of standard forms to be signed by the patient, under penalty of a flawed consent to treatment and consequent healthcare liability in the event of an adverse event. The regulation mandates that safety must be guaranteed through proper prevention tools and health care risk management, in con-junction with the most effective use of structural, technological and organizational resources available. It further spells out the obligation of health care professionals to contribute to risk prevention while administering health care procedures. For this reason, the consent information constitutes a source of risk for the responsibility of the healthcare provider and the Facility and it must necessarily be managed. Risk Management is the management tool that can allow the healthcare facility to improve the quality and safety of the services provided, optimizing the risk of adverse events through proper moni-toring of the same. This paper will be published, following a special agreement, on the two journals "Igiene e Sanità Pubblica" and "La Clinica Tera-peutica", in Italian and in English, in order to increase the diffusion to a wider audience.


Assuntos
Consentimento Livre e Esclarecido , Gestão de Riscos , Atenção à Saúde , Feminino , Pessoal de Saúde , Serviços de Saúde , Humanos
12.
Bone ; 122: 52-75, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30772601

RESUMO

MicroRNA (miRNA) has shown to enhance or inhibit cell proliferation, differentiation and activity of different cell types in bone tissue. The discovery of miRNA actions and their targets has helped to identify them as novel regulations actors in bone. Various studies have shown that miRNA deregulation mediates the progression of bone-related pathologies, such as osteoporosis. The present review intends to give an exhaustive overview of miRNAs with experimentally validated targets involved in bone homeostasis and highlight their possible role in osteoporosis development. Moreover, the review analyzes miRNAs identified in clinical trials and involved in osteoporosis.


Assuntos
Osso e Ossos/metabolismo , Epigênese Genética , Regulação da Expressão Gênica , MicroRNAs/genética , Osteoporose/genética , Animais , Diferenciação Celular/genética , Humanos , MicroRNAs/metabolismo , Osteoblastos/metabolismo , Osteoblastos/patologia
13.
Sci Adv ; 5(7): eaaw5805, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31360768

RESUMO

Advances in developing ultrafast coherent sources operating at extreme ultraviolet (EUV) and x-ray wavelengths allow the extension of nonlinear optical techniques to shorter wavelengths. Here, we describe EUV transient grating spectroscopy, in which two crossed femtosecond EUV pulses produce spatially periodic nanoscale excitations in the sample and their dynamics is probed via diffraction of a third time-delayed EUV pulse. The use of radiation with wavelengths down to 13.3 nm allowed us to produce transient gratings with periods as short as 28 nm and observe thermal and coherent phonon dynamics in crystalline silicon and amorphous silicon nitride. This approach allows measurements of thermal transport on the ~10-nm scale, where the two samples show different heat transport regimes, and can be applied to study other phenomena showing nontrivial behaviors at the nanoscale, such as structural relaxations in complex liquids and ultrafast magnetic dynamics.

14.
Br J Pharmacol ; 153(5): 907-14, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17982475

RESUMO

BACKGROUND AND PURPOSE: Increased angiotensin II levels and insulin resistance coexist at the early stages of cardiomyopathies. To determine whether angiotensin II increases insulin resistance in cardiomyocytes, we studied the effect of angiotensin II on basal and insulin-stimulated transport rate of energy substrates in immortalized cardiomyocytes (HL-1 cells). EXPERIMENTAL APPROACH: Glucose and palmitic acid uptakes were measured using [(3)H]2-deoxy-D-glucose and [(14)C]palmitic acid, respectively, in cells exposed or not exposed to angiotensin II (100 nM), angiotensin II plus irbesartan or PD123319, type 1 and 2 receptor antagonists, or PD98059, an inhibitor of ERK1/2 activation. Cell viability, DNA, protein synthesis and surface area were evaluated by the MTT test, [(3)H]thymydine, [(3)H]leucine and morphometric analysis, respectively. Type 1 receptor levels were measured by western blot analysis. KEY RESULTS: Basal uptakes of glucose and palmitic acid by HL-1 cells (0.37+/-0.07 and 7.31+/-0.22 pmol per 10(4)cells per min, respectively) were both stimulated by 100 nM insulin (+91 and +64%, respectively). Cells exposed to angiotensin II remained viable and did not show signs of hypertrophy. In these conditions, the basal palmitic acid uptake of the cells increased (11.41+/-0.46 pmol per 10(4) cells per min) and insulin failed to stimulate the uptake of glucose and fatty acids. Changes in the rate of uptake of energy substrates were prevented or significantly reduced by irbesartan or PD98059. CONCLUSIONS AND IMPLICATIONS: Angiotensin II is a candidate for increasing insulin resistance in cardiomyocytes. Our results suggest a further mechanism for the cardiovascular protection offered by the angiotensin II type 1 receptor blockers.


Assuntos
Angiotensina II/farmacologia , Resistência à Insulina , Insulina/metabolismo , Miócitos Cardíacos/metabolismo , Receptor Tipo 1 de Angiotensina/efeitos dos fármacos , Bloqueadores do Receptor Tipo 1 de Angiotensina II/farmacologia , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Glucose/metabolismo , Hipertrofia , Camundongos , Ácido Palmítico/metabolismo , Receptor Tipo 1 de Angiotensina/metabolismo
15.
Nat Commun ; 9(1): 4659, 2018 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-30405105

RESUMO

Short wavelength free-electron lasers (FELs), providing pulses of ultrahigh photon intensity, have revolutionized spectroscopy on ionic targets. Their exceptional photon flux enables multiple photon absorptions within a single femtosecond pulse, which in turn allows for deep insights into the photoionization process itself as well as into evolving ionic states of a target. Here we employ ultraintense pulses from the FEL FERMI to spectroscopically investigate the sequential emission of electrons from gaseous, atomic argon in the neutral as well as the ionic ground state. A pronounced forward-backward symmetry breaking of the angularly resolved emission patterns with respect to the light propagation direction is experimentally observed and theoretically explained for the region of the Cooper minimum, where the asymmetry of electron emission is strongly enhanced. These findings aim to originate a better understanding of the fundamentals of photon momentum transfer in ionic matter.

16.
Br J Pharmacol ; 150(8): 1003-10, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17339841

RESUMO

BACKGROUND AND PURPOSE: Methylamine is an endogenous aliphatic amine exhibiting anorexigenic properties in mice. The aim of this work was to show whether methylamine also modifies feeding behaviour in rats and, if so, to identify the mediator(s) responsible for such effects. EXPERIMENTAL APPROACH: Microdialysis experiments with the probe inserted in the periventricular hypothalamic nucleus were carried out in 12 h starved, freely moving rats. Collected perfusate samples following methylamine injection (i.c.v.) were analysed for nitric oxide by chemiluminescence and for dopamine and 5-hydroxytryptamine content by HPLC. Kv1.6 potassium channel expression was reduced by antisense strategy and this decrease quantified by semi-quantitative RT-PCR analysis. KEY RESULTS: Methylamine showed biphasic dose-related effects on rat feeding. At doses of 15-30 microg per rat, it was hyperphagic whereas higher doses (60-80 microg) were hypophagic. Methylamine stimulated central nitric oxide (+115% vs. basal) following hyperphagic and dopamine release (60% over basal values) at hypophagic doses, respectively. Treatment with L-N(G)-nitro-L-arginine-methyl ester (i.c.v. 2 microg 10 microl(-1)) or with alpha-methyl-p-tyrosine (i.p. 100 mg kg(-1)) before methylamine injection, reduced nitric oxide output and hyperphagia, or dopamine release and hypophagia respectively. Moreover, hypophagia and hyperphagia, as well as nitric oxide and dopamine release were significantly reduced by down-regulating brain Kv1.6 potassium channel expression. CONCLUSIONS AND IMPLICATIONS: The effects of methylamine on feeding depend on the hypothalamic release of nitric oxide and dopamine as a result of interaction at the Kv1.6 channels. The study of methylamine levels in the CNS may provide new perspectives on the physiopathology of alimentary behaviour.


Assuntos
Depressores do Apetite/metabolismo , Regulação do Apetite , Dopamina/metabolismo , Jejum , Hipotálamo/metabolismo , Metilaminas/metabolismo , Óxido Nítrico/metabolismo , Animais , Depressores do Apetite/administração & dosagem , Regulação do Apetite/efeitos dos fármacos , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacologia , Hiperfagia/metabolismo , Hiperfagia/fisiopatologia , Hipotálamo/efeitos dos fármacos , Injeções Intraventriculares , Canal de Potássio Kv1.6/efeitos dos fármacos , Canal de Potássio Kv1.6/genética , Canal de Potássio Kv1.6/metabolismo , Masculino , Metilaminas/administração & dosagem , Microdiálise , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico Sintase/metabolismo , Oligonucleotídeos Antissenso/genética , Oligonucleotídeos Antissenso/metabolismo , Ratos , Ratos Wistar , Serotonina/metabolismo , Fatores de Tempo , Tirosina 3-Mono-Oxigenase/antagonistas & inibidores , Tirosina 3-Mono-Oxigenase/metabolismo , alfa-Metiltirosina/farmacologia
17.
Struct Dyn ; 4(5): 055101, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28713843

RESUMO

We report the results of resonant magnetic XUV reflectivity experiments performed at the XUV free-electron laser FERMI. Circularly polarized XUV light with the photon energy tuned to the Fe M2,3 edge is used to measure resonant magnetic reflectivities and the corresponding Q-resolved asymmetry of a Permalloy/Ta/Permalloy trilayer film. The asymmetry exhibits ultrafast changes on 240 fs time scales upon pumping with ultrashort IR laser pulses. Depending on the value of the wavevector transfer Qz , we observe both decreasing and increasing values of the asymmetry parameter, which is attributed to ultrafast changes in the vertical spin and charge density profiles of the trilayer film.

18.
Aliment Pharmacol Ther ; 23(8): 1143-51, 2006 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-16611275

RESUMO

BACKGROUND: Recent studies suggest a role of n-3 long-chain polyunsaturated fatty acids (n-3 PUFA) as peroxisome proliferator-activated receptor-alpha ligands in improving non-alcoholic fatty liver disease (NAFLD) in rodents. However, data in humans are still lacking. AIM: To evaluate the efficacy of prolonged PUFA supplementation in patients with NAFLD. METHODS: Fifty-six patients with NAFLD were enrolled. Among the overall eligible patients, 42 assumed n-3 PUFA 1-g capsule daily for 12 months, whereas 14 refused the treatment and were analysed as controls. All patients underwent haematochemical and ultrasound follow-up. RESULTS: Polyunsaturated fatty acid supplementation significantly decreased serum aspartate transaminase (P = 0.003), alanine transaminase (P = 0.002), gamma-glutamyl transpeptidase (P = 0.03), triglycerides (P = 0.02) and fasting glucose (P = 0.02) in comparison with controls. Circulating arachidonate and n-6/n-3 fatty acid ratio was reduced (P = 0.0002, and P = 0.0001 respectively) in treated patients. Moreover, ultrasonography demonstrated improvement of liver echotexture after PUFA (P = 0.0001), and increase of Doppler perfusion index (P = 0.001), whereas no significant changes occurred in controls. CONCLUSIONS: Supplementation with n-3 PUFA improves biochemical, ultrasonographic and haemodynamic features of liver steatosis. Our study supports the efficacy of n-3 PUFA as a new therapeutic approach in the treatment of NAFLD.


Assuntos
Ácidos Graxos Ômega-3/administração & dosagem , Fígado Gorduroso/tratamento farmacológico , Adulto , Idoso , Alanina Transaminase/sangue , Aspartato Aminotransferases/sangue , Glicemia/análise , Estudos de Casos e Controles , Suplementos Nutricionais , Fígado Gorduroso/sangue , Fígado Gorduroso/diagnóstico por imagem , Feminino , Humanos , Fígado/diagnóstico por imagem , Fígado/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Triglicerídeos/sangue , Ultrassonografia Doppler , gama-Glutamiltransferase/sangue
19.
Sci Rep ; 6: 38796, 2016 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-27941842

RESUMO

In the past few years, we have been witnessing an increased interest for studying materials properties under non-equilibrium conditions. Several well established spectroscopies for experiments in the energy domain have been successfully adapted to the time domain with sub-picosecond time resolution. Here we show the realization of high resolution resonant inelastic X-ray scattering (RIXS) with a stable ultrashort X-ray source such as an externally seeded free electron laser (FEL). We have designed and constructed a RIXS experimental endstation that allowed us to successfully measure the d-d excitations in KCoF3 single crystals at the cobalt M2,3-edge at FERMI FEL (Elettra-Sincrotrone Trieste, Italy). The FEL-RIXS spectra show an excellent agreement with the ones obtained from the same samples at the MERIXS endstation of the MERLIN beamline at the Advanced Light Source storage ring (Berkeley, USA). We established experimental protocols for performing time resolved RIXS experiments at a FEL source to avoid X ray-induced sample damage, while retaining comparable acquisition time to the synchrotron based measurements. Finally, we measured and modelled the influence of the FEL mixed electromagnetic modes, also present in externally seeded FELs, and the beam transport with ~120 meV experimental resolution achieved in the presented RIXS setup.

20.
Rev Sci Instrum ; 86(8): 083901, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26329205

RESUMO

Ultrafast magnetization reversal of a ferrimagnetic metallic alloy GdFeCo was investigated by time-resolved resonant magneto-optical Kerr effect measurements using a seeded free electron laser. The GdFeCo alloy was pumped by a linearly polarized optical laser pulse, and the following temporal evolution of the magnetization of Fe in GdFeCo was element-selectively traced by a probe free electron laser pulse with a photon energy tuned to the Fe M-edge. The results have been measured using rotating analyzer ellipsometry method and confirmed magnetization switching caused by ultrafast heating.

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