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1.
Sci Rep ; 12(1): 10309, 2022 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-35725989

RESUMO

The aim of the study was to evaluate adrenal axis hyperactivation measuring hair cortisol levels, and its influence on the relationship among metabolic parameters, inflammation markers and androgens in adult women with PCOS. 44 women (18-34 years) with PCOS diagnosis and a control group of 49 healthy women (19-35 years) were included. In both gropus body mass index (BMI) was calculated and waist circumference (WC) was measured. Hair cortisol, total serum testosterone (TT), serum cortisol, 25 OH vitamin D (25OHD), insulin, high sensitivity C-reactive protein (hsCRP), triglycerides (TG), HDL cholesterol (HDL), glucose and leptin were measured. Bioavailable testosterone (bioT) was calculated. Hair cortisol concentration was higher and significantly different in PCOS patients compared to the control group (130 vs 63 pg/mg of hair, p < 0.001). Subsequently, patients with PCOS were divided into two groups according to hair cortisol levels: group 1 with normal hair cortisol concentration and group 2 with levels above the upper limit of the reference values (128 pg/mg of hair). In group 2, TT significantly correlated with 25OHD, hsCRP, TG/HDL index, BMI, WC, insulin and HOMA (p < 0.05); bioT correlated with hsCRP and leptin (p < 0.05). Finally, 25OHD was inversely correlated with leptin and with TG/HDL index (p < 0.05). High hair cortisol concentration in patients with PCOS confirmed hyperactivation of the HPA axis. The associations observed were only found in patients with PCOS with high hair cortisol levels (> 128 pg/mg of hair), showing a possible effect of HPA axis in these associations.


Assuntos
Cabelo , Hidrocortisona , Síndrome do Ovário Policístico , Adolescente , Adulto , Índice de Massa Corporal , Proteína C-Reativa/metabolismo , Feminino , Cabelo/química , Humanos , Hidrocortisona/análise , Sistema Hipotálamo-Hipofisário/metabolismo , Insulina , Resistência à Insulina , Leptina/metabolismo , Obesidade/complicações , Sistema Hipófise-Suprarrenal/metabolismo , Síndrome do Ovário Policístico/metabolismo , Testosterona , Adulto Jovem
2.
Phys Rev Lett ; 126(19): 196407, 2021 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-34047592

RESUMO

We report the observation of a nontrivial spin texture in Dirac node arcs, i.e., novel topological objects formed when Dirac cones of massless particles extend along an open one-dimensional line in momentum space. We find that such states are present in all the compounds of the tetradymite M_{2}Te_{2}X family (M=Ti, Zr, or Hf and X=P or As) regardless of the weak or strong character of the topological invariant. The Dirac node arcs in tetradymites are thus the simplest possible textbook example of a type-I Dirac system with a single spin-polarized node arc.

3.
J Synchrotron Radiat ; 26(Pt 1): 280-290, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30655496

RESUMO

A new instrument named COMET for COherent Magnetic scattering Experiments in Transmission using polarized soft X-rays has been designed and built. This high-vacuum setup is placed at the intermediate focal point of the elastic branch of the SEXTANTS beamline at Synchrotron SOLEIL. The main application is in solid state physics, the instrument being optimized for studying material properties using coherent scattering of soft X-rays with an emphasis on imaging, with chemical selectivity, the magnetic domains of artificially nano-structured materials. The instrument's principal features are presented and illustrated through recently performed experiments.

4.
Sci Rep ; 8(1): 9339, 2018 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-29921938

RESUMO

In thin magnetic films with perpendicular magnetic anisotropy, a periodic "up-down" stripe-domain structure can be originated at remanence, on a mesoscopic scale (~100 nm) comparable with film thickness, by the competition between short-range exchange coupling and long-range dipolar interaction. However, translational order is perturbed because magnetic edge dislocations are spontaneously nucleated. Such topological defects play an important role in magnetic films since they promote the in-plane magnetization reversal of stripes and, in superconductor/ferromagnet hybrids, the creation of superconducting vortex clusters. Combining magnetic force microscopy experiments and micromagnetic simulations, we investigated the motion of two classes of magnetic edge dislocations, randomly distributed in an [Formula: see text]-implanted Fe film. They were found to move in opposite directions along straight trajectories parallel to the stripes axis, when driven by a moderate dc magnetic field. Using the approximate Thiele equation, analytical expressions for the forces acting on such magnetic defects and a microscopic explanation for the direction of their motion could be obtained. Straight trajectories are related to the presence of a periodic stripe domain pattern, which imposes the gyrotropic force to vanish even if a nonzero, half-integer topological charge is carried by the defects in some layers across the film thickness.

5.
Stress Health ; 34(2): 227-234, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28834143

RESUMO

Reminiscence is a psychological intervention that uses the recall of past events, feelings, and thoughts to facilitate pleasure, quality of life, and adjustment to present life. The main goal of this study was to investigate the effect of a reminiscence intervention programme on coping strategies. One hundred fifty healthy older adults attended the reminiscence sessions. In order to evaluate the effects of the programme and find out if its effects lasted over time, we used an experimental design with pretest, posttest, and follow-up assessments, comparing a control group to the intervention group. Repeated-measures analysis of variance showed significant differences in problem-solving coping, positive reappraisal, social support seeking, and avoidance coping with the treatment group obtaining higher scores than the control group in all cases. The effects declined after 3 months, but some differences were found in the treatment group obtaining higher scores in problem-solving coping and positive reappraisal and lower in overt emotional expression. The study suggests that reminiscence therapy contributes to mental health by enhancing coping strategies that can allow the elderly to cope successfully and overcome psychological distress.


Assuntos
Adaptação Psicológica/fisiologia , Memória Episódica , Rememoração Mental/fisiologia , Avaliação de Resultados em Cuidados de Saúde , Psicoterapia/métodos , Apoio Social , Estresse Psicológico/reabilitação , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino
6.
J Phys Condens Matter ; 29(46): 465803, 2017 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-29067917

RESUMO

The resonant eigenmodes of an α'-FeN thin film characterized by weak stripe domains are investigated by Brillouin light scattering and broadband ferromagnetic resonance experiments, assisted by micromagnetic simulations. The spectrum of the dynamic eigenmodes in the presence of the weak stripes is very rich and two different families of modes can be selectively detected using different techniques or different experimental configurations. Attention is paid to the evolution of the mode frequencies and spatial profiles under the application of an external magnetic field, of variable intensity, in the direction parallel or transverse to the stripes. The different evolution of the modes with the external magnetic field is accompanied by a distinctive spatial localization in specific regions, such as the closure domains at the surface of the stripes and the bulk domains localized in the inner part of the stripes. The complementarity of BLS and FMR techniques, based on different selection rules, is found to be a fruitful tool for the study of the wealth of localized magnetic excitations generally found in nanostructures.

7.
Nat Commun ; 7: 11781, 2016 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-27283225

RESUMO

Two-dimensional electron gases at oxide surfaces or interfaces show exotic ordered states of matter, like superconductivity, magnetism or spin-polarized states, and are a promising platform for alternative oxide-based electronics. Here we directly image a dense population of randomly distributed ferromagnetic domains of ∼40 nm typical sizes at room temperature at the oxygen-deficient surface of SrTiO3, a non-magnetic transparent insulator in the bulk. We use laser-based photoemission electron microscopy, an experimental technique that gives selective spin detection of the surface carriers, even in bulk insulators, with a high spatial resolution of 2.6 nm. We furthermore find that the Curie temperature in this system is as high as 900 K. These findings open perspectives for applications in nano-domain magnetism and spintronics using oxide-based devices, for instance through the nano-engineering of oxygen vacancies at surfaces or interfaces of transition-metal oxides.

8.
Nat Mater ; 13(12): 1085-90, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25306421

RESUMO

Two-dimensional electron gases (2DEGs) forming at the interfaces of transition metal oxides exhibit a range of properties, including tunable insulator-superconductor-metal transitions, large magnetoresistance, coexisting ferromagnetism and superconductivity, and a spin splitting of a few meV (refs 10, 11). Strontium titanate (SrTiO3), the cornerstone of such oxide-based electronics, is a transparent, non-magnetic, wide-bandgap insulator in the bulk, and has recently been found to host a surface 2DEG (refs 12-15). The most strongly confined carriers within this 2DEG comprise two subbands, separated by an energy gap of 90 meV and forming concentric circular Fermi surfaces. Using spin- and angle-resolved photoemission spectroscopy (SARPES), we show that the electron spins in these subbands have opposite chiralities. Although the Rashba effect might be expected to give rise to such spin textures, the giant splitting of almost 100 meV at the Fermi level is far larger than anticipated. Moreover, in contrast to a simple Rashba system, the spin-polarized subbands are non-degenerate at the Brillouin zone centre. This degeneracy can be lifted by time-reversal symmetry breaking, implying the possible existence of magnetic order. These results show that confined electronic states at oxide surfaces can be endowed with novel, non-trivial properties that are both theoretically challenging to anticipate and promising for technological applications.

9.
Sci Rep ; 4: 3586, 2014 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-24394996

RESUMO

Two-dimensional electron gases (2DEGs) at transition-metal oxide (TMO) interfaces, and boundary states in topological insulators, are being intensively investigated. The former system harbors superconductivity, large magneto-resistance, and ferromagnetism. In the latter, honeycomb-lattice geometry plus bulk spin-orbit interactions lead to topologically protected spin-polarized bands. 2DEGs in TMOs with a honeycomb-like structure could yield new states of matter, but they had not been experimentally realized, yet. We successfully created a 2DEG at the (111) surface of KTaO3, a strong insulator with large spin-orbit coupling. Its confined states form a network of weakly-dispersing electronic gutters with 6-fold symmetry, a topology novel to all known oxide-based 2DEGs. If those pertain to just one Ta-(111) bilayer, model calculations predict that it can be a topological metal. Our findings demonstrate that completely new electronic states, with symmetries not realized in the bulk, can be tailored in oxide surfaces, promising for TMO-based devices.

10.
Nature ; 469(7329): 189-93, 2011 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-21228872

RESUMO

As silicon is the basis of conventional electronics, so strontium titanate (SrTiO(3)) is the foundation of the emerging field of oxide electronics. SrTiO(3) is the preferred template for the creation of exotic, two-dimensional (2D) phases of electron matter at oxide interfaces that have metal-insulator transitions, superconductivity or large negative magnetoresistance. However, the physical nature of the electronic structure underlying these 2D electron gases (2DEGs), which is crucial to understanding their remarkable properties, remains elusive. Here we show, using angle-resolved photoemission spectroscopy, that there is a highly metallic universal 2DEG at the vacuum-cleaved surface of SrTiO(3) (including the non-doped insulating material) independently of bulk carrier densities over more than seven decades. This 2DEG is confined within a region of about five unit cells and has a sheet carrier density of ∼0.33 electrons per square lattice parameter. The electronic structure consists of multiple subbands of heavy and light electrons. The similarity of this 2DEG to those reported in SrTiO(3)-based heterostructures and field-effect transistors suggests that different forms of electron confinement at the surface of SrTiO(3) lead to essentially the same 2DEG. Our discovery provides a model system for the study of the electronic structure of 2DEGs in SrTiO(3)-based devices and a novel means of generating 2DEGs at the surfaces of transition-metal oxides.

11.
J Med Genet ; 43(7): e38, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16816025

RESUMO

BACKGROUND: Overlapping phenotypes including LHON, MELAS, and Leigh syndrome have recently been associated with numerous mtDNA point mutations in the ND5 gene of complex I, now considered a mutational hot spot. OBJECTIVE: To identify the mtDNA defect in a family with a prevalent ocular phenotype, including LHON-like optic neuropathy, retinopathy, and cataract, but characterised also by strokes, early deaths, and miscarriages on the maternal line. RESULTS: Sequencing of the entire mitochondrial genome from the proband's muscle DNA identified the heteroplasmic 13042G-->A transition, which was previously described only once in a patient with a different mitochondrial disease. This mutation fulfils the major pathogenic criteria, inducing an amino acid change (A236T) at an invariant position in a highly conserved domain of the ND5 gene. Phosphorus magnetic resonance spectroscopy in the proband disclosed an in vivo brain and skeletal muscle energy metabolism deficit. CONCLUSIONS: These findings conclusively establish the pathogenic role of the 13042G-->A mutation and underscore its variable clinical expression.


Assuntos
DNA Mitocondrial/genética , Oftalmopatias/genética , Polimorfismo de Nucleotídeo Único , Pareamento Incorreto de Bases , Encéfalo/patologia , Humanos , Espectroscopia de Ressonância Magnética , Mutação , Reação em Cadeia da Polimerase , Prevalência
12.
Arch Esp Urol ; 59(3): 313-6, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16724722

RESUMO

OBJECTIVES: Male infertility caused by irreparable obstructive azoospermia is widely treated with MESA (Microsurgical Epididymal Sperm Aspiration) or TESE (Testicular Sperm Extraction) or PESA (Percutaneous Epididymal Sperm Aspiration) followed by an Intracytoplasmatic Spermatozoa Injection (ICSI). For each procedures are claimed advantages and disadvantages. Aim of this work is to describe our technique (OESA) for sperm retrieval reporting the results. METHODS: From 1998 to 2003 153 sperm retrieval procedures in azoospermic patients were performed. The technique consists in a small (1 cm.) surgical incision of scrotal wall under local or spinal anaesthesia. After inspecting the intrascrotal component to record the status of the epididymis and of the testicle, epididymal sperm aspiration was performed in the most appropriate site with 18 gauge needle. The aspirated spermatozoa were used immediately after aspiration not being permitted in our Institute cryopreservation. When no sperms were found TESE was performed. RESULTS: In 78 cases aspiration from epididymis was successful (OESA). In the other patients (75) TESE was performed. Higher count of spermatozoa were retrieved in all cases of OESA. Pregnancy rate was 26.6% for OESA and 6.4% for TESE. No complications occurred. CONCLUSIONS: This technique is very simple and easy allowing to obtain the advantages of microsurgical techniques (mainly choice of the most appropriate site of aspiration and immediate haemostasis if needed) with minimal invasivity (avoiding epididymal surgical incision). Moreover if OESA does not allow sperm extraction is possible to perform immediately TESE.


Assuntos
Epididimo/cirurgia , Espermatozoides , Coleta de Tecidos e Órgãos/métodos , Humanos , Infertilidade Masculina , Masculino , Procedimentos Cirúrgicos Minimamente Invasivos
13.
Arch. esp. urol. (Ed. impr.) ; 59(3): 313-316, abr. 2006. tab
Artigo em En | IBECS | ID: ibc-046834

RESUMO

OBJETIVO: La infertilidad masculina causada por azoospermia obstructiva irreparable se trata ampliamente con aspiración epididimaria microquirúrgica (MESA- microsurgical Epiddymal sperm Aspiration) o percutánea (PESA- Percutaneous Epididymal Sperm Aspiration), o con extracción testicular (TESE- Testicular Sperm Extraction) seguida por ICSI (Intracytoplasmatic spermatozoa injection). Cada uno de los procedimientos tiene ventajas e inconvenientes. El objetivo del presente artículo es describir nuestra técnica para la obtención de espermatozoides (OESA- Open Epididymal Sperm Aspiration) y comunicar nuestros resultados. MÉTODOS: Entre 1998 y 2003 se realizaron 153 procedimientos para la obtención de espermatozoides. La técnica consiste en una pequeña incisión escrotal (1 cm) bajo anestesia local o espinal. Después de inspeccionar el contenido escrotal para evaluar el estado del epidídimo y del testículo se procede a la aspiración epididimaria en el sitio más apropiado con una aguja del 18 gauge. Los espermatozoides aspirados se utilizan inmediatamente después de la aspiración porque nuestra institución no permite la criopreservación. Cuando no se encuentran espermatozoides se procede a TESE. RESULTADOS: La aspiración epididimaria fue satisfactoria en 78 casos. En los otros pacientes (75) se realizó TESE. En los casos de OESA se obtuvo un número mayor de espermatozoides. La tasa de embarazos fue del 26,6% con OESA y 6,4 % con TESE. No hubo complicaciones. CONCLUSIONES: Esta técnica es muy simple y fácil de realizar, permitiendo conseguir las ventajas de las técnicas microquirúrgicas (principalmente la elección del sitio más apropiado para la aspiración y hemostasia inmediata cuando es necesario) con mínima invasión (evitando la incisión quirúrgica del epidídimo). Además, si la OESA no obtiene espermatozoides es posible realizar inmediatamente TESE


OBJECTIVES: Male infertility caused by irreparable obstructive azoospermia is widely treated with MESA (Microsurgical Epididymal Sperm Aspiration) or TESE (Testicular Sperm Extraction) or PESA (Percutaneous Epididymal Sperm Aspiration) followed by an Intracytoplasmatic Spermatozoa Injection (ICSI). For each procedures are claimed advantages and disadvantages. Aim of this work is to describe our technique (OESA) for sperm retrieval reporting the results. METHODS: From 1998 to 2003 153 sperm retrieval procedures in azoospermic patients were performed. The technique consists in a small (1 cm.) surgical incision of scrotal wall under local or spinal anaesthesia. After inspecting the intrascrotal component to record the status of the epididymis and of the testicle, epididymal sperm aspiration was performed in the most appropriate site with 18 gauge needle. The aspirated spermatozoa were used immediately after aspiration not being permitted in our Institute cryopreservation. When no sperms were found TESE was performed. RESULTS: In 78 cases aspiration from epididymis was successful (OESA). In the other patients (75) TESE was performed. Higher count of spermatozoa were retrieved in all cases of OESA. Pregnancy rate was 26,6% for OESA and 6,4% for TESE. No complications occurred. CONCLUSIONS: This technique is very simple and easy allowing to obtain the advantages of microsurgical techniques (mainly choice of the most appropriate site of aspiration and immediate haemostasis if needed) with minimal invasivity (avoiding epididymal surgical incision). Moreover if OESA does not allow sperm extraction is possible to perform immediately TESE


Assuntos
Masculino , Humanos , Epididimite/cirurgia , Espermatozoides , Infertilidade Masculina , Procedimentos Cirúrgicos Minimamente Invasivos
14.
Arch Esp Urol ; 57(8): 870-2, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15560282

RESUMO

OBJECTIVES: Leiomyosarcoma is a rare histological subtype of renal sarcomas, accounting for approximately 50-60% of the reported cases. Spontaneous rupture of renal tumor is an uncommon event and the most frequent cause is angiomyolipoma. We report a case of spontaneous rupture of leiomyosarcoma in a 45-year-old woman, presenting with severe left flank pain and perirenal hemorrhage. METHODS: A 45-year-old caucasian white woman was transferred to our department from emergency room of a different Hospital for acute left flank pain interpreted as a renal colic not responsive to medical therapy. On clinical examination patient was haemodynamically stable but with rapid decrease in hemoglobin, pale, without haematuria with a persistent left flank and hypochondrium pain as in acute abdomen. CT scan of abdomen showed a retroperitoneal haematoma around the left kidney, and a large heterogeneous mass. RESULTS: Laparotomy was urgently performed. There was large retroperitoneal hematoma extending from left kidney to pelvic space. At the upper pole of the kidney a bleeding tumor was found. Radical nephrectomy was performed. The histological diagnosis was of low-grade leiomyosarcoma from renal angiomyolipoma. CONCLUSIONS: We attract attention both on kidney cancer (at our knowledge only 3 cases described in literature) and on the need of imaging in the clinical approach of renal colic. We strongly believe that the patients presenting at emergency for renal colic must be scanned by ultrasounds or TC.


Assuntos
Neoplasias Renais/complicações , Leiomiossarcoma/complicações , Feminino , Humanos , Pessoa de Meia-Idade , Ruptura Espontânea
15.
Arch. esp. urol. (Ed. impr.) ; 57(8): 870-872, oct. 2004.
Artigo em Es | IBECS | ID: ibc-35827

RESUMO

OBJETIVOS: El leiomiosarcoma es un tipo de sarcomas renal poco frecuente, que supone aproximadamente el 50-60 por ciento de los casos comunicados. La rotura espontánea de un tumor renal es un acontecimiento raro, siendo la causa más frecuente el angiomiolipoma. Presentamos un caso de rotura espontánea de un leiomiosarcoma en una mujer de 45 años con dolor lumbar izquierdo severo y hemorragia perirrenal. MÉTODOS: Mujer blanca de 45 años de edad derivada a nuestro departamento desde el servicio de urgencias de otro hospital por un dolor lumbar izquierdo agudo interpretado como cólico renal sin respuesta a tratamiento médico. En la exploración física la paciente estaba hemodinámicamente estable pero presentaba un rápido descenso de la hemoglobina, estaba pálida, no tenía hematuria y tenía un dolor persistente en fosa lumbar e hipocondrio izquierdos sugestivos de abdomen agudo. Un TAC abdominal demostró un hematoma retroperitoneal alrededor del riñón izquierdo y una gran masa heterogénea. RESULTADOS: Se realizó laparotomía de urgencias. Había un gran hematoma retroperitoneal que se extendía desde el riñón izquierdo hasta la pelvis. En el polo superior del riñón se encontró un tumor que sangraba. Se realizó nefrectomía radical. El diagnóstico anatomopatológico fue leiomiosarcoma de bajo grado con origen en un angiomiolipoma renal. CONCLUSIONES: Llamamos la atención sobre dos aspectos: el cáncer renal (según nuestros datos hay sólo tres casos descritos en la literatura) y la necesidad de realizar estudios de imagen en el abordaje clínico del cólico renal. Creemos firmemente que a los pacientes vistos en urgencias con cólico renal se les debe realizar ecografía o TAC (AU)


Assuntos
Feminino , Humanos , Pessoa de Meia-Idade , Ruptura Espontânea , Leiomiossarcoma , Neoplasias Renais
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