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1.
Nano Lett ; 23(20): 9413-9419, 2023 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-37820373

RESUMO

Two-dimensional Mott materials have recently been reported in the dichalcogenide family with high potential for Mottronic applications. Nevertheless, their widespread use as a single or few layers is hampered by their limited device integration resulting from their growth on graphene, a metallic substrate. Here, we report on the fabrication of 1T-TaSe2 monolayers grown by molecular beam epitaxy on semiconducting gallium phosphide substrates. At the nanoscale, the charge density wave reconstruction and a moiré pattern resulting from the monolayer interaction with the substrate are observed by scanning tunneling microscopy. The fully open gap unveiled by tunneling spectroscopy, which can be further manipulated by the proximity of a metal tip, is confirmed by transport measurements from micrometric to millimetric scales, demonstrating a robust Mott insulating phase at up to 400 K.

2.
Phys Rev Lett ; 121(1): 016601, 2018 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-30028165

RESUMO

Out of equilibrium phenomena are a major issue of modern physics. In particular, correlated materials such as Mott insulators experience fascinating long-lived exotic states under a strong electric field. Yet, the origin of their destabilization by the electric field is not elucidated. Here we present a comprehensive study of the electrical response of canonical Mott insulators GaM_{4}Q_{8} (M=V, Nb, Ta, Mo; Q=S, Se) in the context of a microscopic theory of electrical breakdown where in-gap states allow for a description in terms of a two-temperature model. Our results show how the nonlinearities and the resistive transition originate from a massive creation of hot electrons under an electric field. These results give new insights for the control of the long-lived states reached under an electric field in these systems which has recently open the way to new functionalities used in neuromorphic applications.

3.
BMC Res Notes ; 9: 294, 2016 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-27267960

RESUMO

BACKGROUND: We describe a male with functionally impairing radial deviation of the thumb who presented to us at 24 years of age. Two sclerotic skin lesions had been excised 7 years before because of consecutive skin contracture. Latest radiological examination showed a spotted pattern consistent with osteopoikilosis. CASE PRESENTATION: A corrective osteotomy of the thumb was carried out due to the patients discomfort. Facing the simultaneous osteo-cutaneous malformation we postulated a Buschke-Ollendorff syndrome. Buschke-Ollendorff syndrome is a rare autosomal-dominant hereditary disorder of connective tissue with typical osteo-cutaneous manifestations. To explore our hypothesis, biopsies were taken from the affected bone lesions and surrounding skin and soft tissue for histological investigation and genetic testing of the LEMD3 gene was performed on blood of the patient. The histology showed typical changes of the bone architecture and a fibrotic collagenous nodule of the skin. The genetic testing on DNA extracted from peripheral blood leucocytes confirmed a heterozygous loss of function mutation in the LEM domain-containing protein 3 (LEMD3) gene coding for the inner nuclear membrane protein MAN1, which causes osteopoikilosis by antagonizing transforming growth factor ß (TGF-ß) and bone morphogenetic protein (BMP) signalling. CONCLUSIONS: In atypical cases of simultaneous occurrence of fibrotic skin lesions and a spotted pattern in the X-ray we recommend the genetic screening of the LEMD3 gene. A correct diagnosis of Buschke-Ollendorff syndrome is necessary to spare patients from expensive investigations and to provide reassurance about the benign nature of the disease.


Assuntos
Anormalidades Múltiplas/patologia , Osteopecilose/patologia , Anormalidades da Pele , Dermatopatias Genéticas/patologia , Polegar/anormalidades , Anormalidades Múltiplas/genética , Sequência de Bases , Análise Mutacional de DNA/métodos , Proteínas de Ligação a DNA , Humanos , Masculino , Proteínas de Membrana/genética , Mutação , Proteínas Nucleares/genética , Osteopecilose/genética , Homologia de Sequência do Ácido Nucleico , Dermatopatias Genéticas/genética , Polegar/cirurgia , Adulto Jovem
4.
Urologe A ; 54(6): 844-8, 2015 Jun.
Artigo em Alemão | MEDLINE | ID: mdl-25875931

RESUMO

This article presents a rare case of a primary neuroendocrine tumor (NET) of the kidney. Abdominal magnetic resonance imaging (MRI) was performed in a 56-year-old man during the follow-up of an adrenal adenoma. Incidentally a renal tumor at the upper pole of the left kidney was diagnosed and was suspected of being a renal cell carcinoma. After partial nephrectomy a NET measuring 4.2 cm in diameter could be diagnosed histologically. An extrarenal primary tumor was ruled out by a postoperative gallium 68-tetraazacyclododecane tetraacetic acid-octreotate (68Ga-DOTATATE) positron emission tomography/computed tomography (PET/CT) scan. A primary NET of the genitourinary tract is rare and less than 100 cases have been reported in the medical literature.


Assuntos
Neoplasias Renais/patologia , Tumores Neuroendócrinos/patologia , Diagnóstico Diferencial , Humanos , Masculino , Pessoa de Meia-Idade , Doenças Raras/patologia
5.
Phys Rev Lett ; 112(4): 047004, 2014 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-24580483

RESUMO

In a superconductor, absorption of photons with an energy below the superconducting gap leads to redistribution of quasiparticles over energy and thus induces a strong nonequilibrium quasiparticle energy distribution. We have measured the electrodynamic response, quality factor, and resonant frequency of a superconducting aluminium microwave resonator as a function of microwave power and temperature. Below 200 mK, both the quality factor and resonant frequency decrease with increasing microwave power, consistent with the creation of excess quasiparticles due to microwave absorption. Counterintuitively, above 200 mK, the quality factor and resonant frequency increase with increasing power. We demonstrate that the effect can only be understood by a nonthermal quasiparticle distribution.

6.
Phys Rev Lett ; 106(16): 161103, 2011 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-21599351

RESUMO

We perform 3+1 general relativistic simulations of rotating core collapse in the context of the collapsar model for long gamma-ray bursts. We employ a realistic progenitor, rotation based on results of stellar evolution calculations, and a simplified equation of state. Our simulations track self-consistently collapse, bounce, the postbounce phase, black hole formation, and the subsequent early hyperaccretion phase. We extract gravitational waves from the spacetime curvature and identify a unique gravitational wave signature associated with the early phase of collapsar formation.

7.
Phys Rev Lett ; 106(16): 167004, 2011 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-21599404

RESUMO

We have directly measured quasiparticle number fluctuations in a thin film superconducting Al resonator in thermal equilibrium. The spectrum of these fluctuations provides a measure of both the density and the lifetime of the quasiparticles. We observe that the quasiparticle density decreases exponentially with decreasing temperature, as theoretically predicted, but saturates below 160 mK to 25-55/µm(3). We show that this saturation is consistent with the measured saturation in the quasiparticle lifetime, which also explains similar observations in qubit decoherence times.

11.
Phys Rev Lett ; 101(16): 166407, 2008 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-18999695

RESUMO

Scanning tunneling microscopy and spectroscopy measurements in the superconducting dichalcogenide 2H-NbS2 show a peculiar superconducting density of states with two well-defined features at 0.97 and 0.53 meV, located, respectively, above and below the value for the superconducting gap expected from the single band s-wave BCS model (Delta=1.76k_(B)T_(c)=0.9 meV). Both features have a continuous temperature evolution and disappear at T_(c)=5.7 K. Moreover, we observe the hexagonal vortex lattice with radially symmetric vortices and a well-developed localized state at the vortex cores. The sixfold star shape characteristic of the vortex lattice of the compound 2H-NbSe2 is, together with the charge density wave order, absent in 2H-NbS2.

12.
Scand J Rheumatol ; 37(2): 135-41, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18415772

RESUMO

OBJECTIVE: We analysed the production of soluble tumour necrosis factor receptors sTNFR1 and sTNFR2 at sites of inflammation and measured their plasma concentrations to evaluate them as biological markers of disease activity. METHODS: Plasma samples of 35 patients with Behçet's disease (BD) were collected prospectively at monthly intervals and grouped for inactive disease, active BD without arthritis, and active BD with arthritis. sTNFR1 and sTNFR2 concentrations were measured using immunoassays and compared with other biological disease activity parameters. Plasma sTNFR levels were compared to synovial fluid (SF) levels in seven patients. Sixteen tissue samples of mucocutaneous lesions were stained for TNFR2 expression by immunohistochemistry. RESULTS: sTNFR1 and sTNFR2 were found at increased plasma concentrations in active BD, with the highest concentration in active BD with arthritis (p<0.001). Concentrations of both sTNFRs were at least three times higher in SF of arthritic joints than in the corresponding plasma samples (p = 0.025). A change of more than 1 ng/mL of sTNFR2 plasma concentrations correlated with a concordant change in arthritic activity (96% confidence interval). Sensitivity to change was superior to that of sTNFR1, and other biological disease activity parameters such as erythrocyte sedimentation rate (ESR), immunoglobulin (Ig)G, IgA, and interleukin (IL)-10 plasma concentrations. A strong staining for TNFR2 was found in mucocutaneous lesions, where mast cells were identified as the major source for this receptor. CONCLUSIONS: This longitudinal study demonstrates that sTNFR2 plasma concentrations are closely linked with active BD, and especially with arthritis. Taken together with the expression of TNFR molecules in mast cells of mucocutaneous lesions, our results indicate a fundamental role for the TNF/TNFR pathway in BD.


Assuntos
Artrite/metabolismo , Síndrome de Behçet/metabolismo , Articulações/metabolismo , Receptores Tipo II do Fator de Necrose Tumoral/metabolismo , Receptores Tipo I de Fatores de Necrose Tumoral/metabolismo , Pele/metabolismo , Líquido Sinovial/metabolismo , Adolescente , Adulto , Artrite/etiologia , Artrite/fisiopatologia , Síndrome de Behçet/complicações , Síndrome de Behçet/fisiopatologia , Biomarcadores/metabolismo , Sedimentação Sanguínea , Estudos Transversais , Feminino , Humanos , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Interleucina-10/sangue , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Transdução de Sinais/fisiologia
13.
Phys Rev Lett ; 98(5): 057003, 2007 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-17358886

RESUMO

We report measurements of the temperature dependence of both in-plane and out-of-plane penetration depths (lambda(a) and lambda(c), respectively) in 2H-NbSe2. Measurements were made with a radio-frequency tunnel diode oscillator circuit at temperatures down to 100 mK. Analysis of the anisotropic superfluid density shows that a reduced energy gap is located on one or more of the quasi-two-dimensional Nb Fermi surface sheets rather than on the Se sheet, in contrast with some previous reports. This result suggests that the gap structure is not simply related to the weak electron-phonon coupling on the Se sheet and is therefore important for microscopic models of anisotropic superconductivity in this compound.

14.
Dtsch Med Wochenschr ; 132(8): 375-8, 2007 Feb 23.
Artigo em Alemão | MEDLINE | ID: mdl-17299676

RESUMO

HISTORY AND CLINICAL FINDINGS: Two years after a first renal transplantation a 53-year-old man suffering from slowly progressing renal failure had developed progressive amyasthenia and myalgia in his legs and arms, but no dyspnea. Clinical examination, especially for neurological and respiratory abnormalities, was unremarkable. INVESTIGATIONS: Laboratory tests revealed a slightly raised calcium level and an extremely high parathormone (PTH) level. The chest x-ray revealed apical infiltrates, which were interpreted as diffuse pulmonary calcifications caused by hyperparathyroidism. TREATMENT AND COURSE: "Tertiary" hyperparathyroidism was diagnosed. After resection of five hyperplastic parathyroid glands the muscular symptoms disappeared, but the lung infiltates persisted. Four years later a second renal transplantation was necessary. Five years thereafter the patient died of congestive heart failure caused by coronary, hypertensive and valvular heart disease. CONCLUSION: In patients with chronic renal failure and pulmonary infiltrates - with or without respiratory symptoms - calcifications in the context of hyperparathyroidism have to be considered. Calcifications in the lung occur with several other diseases and have a variety of clinical presentations. Prognosis is related to the underlying disease.


Assuntos
Calcinose/etiologia , Hiperparatireoidismo/complicações , Transplante de Rim , Pneumopatias/etiologia , Calcinose/diagnóstico , Cálcio/sangue , Evolução Fatal , Insuficiência Cardíaca/complicações , Humanos , Hiperparatireoidismo/diagnóstico , Hiperparatireoidismo/cirurgia , Falência Renal Crônica/complicações , Falência Renal Crônica/cirurgia , Pneumopatias/diagnóstico , Masculino , Pessoa de Meia-Idade , Debilidade Muscular , Dor , Glândulas Paratireoides/patologia , Glândulas Paratireoides/cirurgia , Hormônio Paratireóideo/sangue
15.
Aktuelle Urol ; 35(4): 326-30, 2004 Aug.
Artigo em Alemão | MEDLINE | ID: mdl-15459874

RESUMO

Prostate cancer (PCa) like other tumors expresses antigens that may serve as target for specific immunotherapy. Special antigen-presenting cells (e. g., dendritic cells) are capable of generating tumor-specific immunity. Cytotoxic T-cells (killer cells) are very effective against antigens and, consequently, against the respective tissue or tumor. Cancer testis antigens (CTA) are expressed in various human cancers but, aside from the testicles, not in normal tissue. Therefore, they are suitable for a specific tumor immunotherapy. We looked at different CTA (LAGE-1, PRAME, MAGE-C2, NY-ESO-1, SSX-2 and PAGE4) and their occurrence in prostatic cancer. Expression of CTA in various PCa cell lines and PCa material from patients was very heterogeneous. Only PAGE4 was expressed in primary PCa and in LnCaP cells as well as in hormone-dependent and hormone-refractory PCa probes. We conclude that PAGE4 should be further evaluated as a potential target for immunotherapy of PCa.


Assuntos
Antígenos de Neoplasias/imunologia , Vacinas Anticâncer/uso terapêutico , Células Dendríticas/imunologia , Imunoterapia , Neoplasias da Próstata/terapia , Animais , Antígenos de Superfície , Vacinas Anticâncer/imunologia , Ensaios Clínicos Fase I como Assunto , Ensaios Clínicos Fase II como Assunto , Humanos , Imunoterapia/métodos , Masculino , Proteínas de Membrana , Camundongos , Proteínas de Neoplasias , Neoplasias Experimentais/imunologia , Neoplasias Experimentais/terapia , Neoplasias da Próstata/imunologia , Proteínas Repressoras , Linfócitos T Citotóxicos/imunologia , Testículo/imunologia , Células Tumorais Cultivadas
16.
J Clin Pathol ; 57(6): 641-3, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15166272

RESUMO

AIMS: To assess the value of homeobox protein CDX-2 expression in the distinction between primary ovarian carcinomas and carcinomas metastatic to the ovary. METHODS: CDX-2 expression was assessed by immunohistochemistry in 120 serous, 68 endometrioid, 24 clear cell, and 16 mucinous carcinomas of the ovary. In addition, CDX-2 immunoreactivity was investigated in 20 metastases from adenocarcinomas to the ovary (15 of colorectal, two of gastric, one of appendiceal, one of pancreatic, and one of cervical origin) and their corresponding primary tumours. RESULTS: Almost all of the primary ovarian carcinomas lacked immunoreactivity for CDX-2. In contrast, 14 of the 16 metastases to the ovary from intestinal primaries showed CDX-2 immunoexpression. CONCLUSION: CDX-2 is a useful marker for differentiating primary ovarian carcinoma from carcinomas metastatic to the ovary.


Assuntos
Biomarcadores Tumorais/análise , Proteínas de Homeodomínio/análise , Proteínas de Neoplasias/análise , Neoplasias Ovarianas/diagnóstico , Neoplasias Ovarianas/secundário , Adenocarcinoma/química , Adenocarcinoma/diagnóstico , Adenocarcinoma/secundário , Fator de Transcrição CDX2 , Neoplasias Colorretais/química , Diagnóstico Diferencial , Feminino , Humanos , Transativadores
19.
J Immunol ; 167(12): 6859-68, 2001 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-11739503

RESUMO

The proteasome is critically involved in the production of MHC class I-restricted T cell epitopes. Proteasome activity and epitope production are altered by IFN-gamma treatment, which leads to a gradual replacement of constitutive proteasomes by immunoproteasomes in vitro. However, a quantitative analysis of changes in the steady state subunit composition of proteasomes during an immune response against viruses or bacteria in vivo has not been reported. Here we show that the infection of mice with lymphocytic choriomeningitis virus or Listeria monocytogenes leads to an almost complete replacement of constitutive proteasomes by immunoproteasomes in the liver within 7 days. Proteasome replacements were markedly reduced in IFN-gamma(-/-) mice, but were only slightly affected in IFN-alphaR(-/-) and perforin(-/-) mice. The proteasome regulator PA28alpha/beta was up-regulated, whereas PA28gamma was reduced in the liver of lymphocytic choriomeningitis virus-infected mice. Proteasome replacements in the liver strongly altered proteasome activity and were unexpected to this extent, since an in vivo half-life of 12 days had been previously assigned to constitutive proteasomes in the liver. Our results suggest that during the peak phase of viral and bacterial elimination the antiviral cytotoxic T lymphocyte response is directed mainly to immunoproteasome-dependent T cell epitopes, which would be a novel parameter for the design of vaccines.


Assuntos
Infecções por Arenaviridae/imunologia , Cisteína Endopeptidases/química , Listeriose/imunologia , Hepatopatias/imunologia , Complexos Multienzimáticos/química , Animais , Infecções por Arenaviridae/enzimologia , Autoantígenos , Cisteína Endopeptidases/genética , Cisteína Endopeptidases/imunologia , Interferon-alfa/fisiologia , Interferon gama/genética , Interferon gama/farmacologia , Interferon gama/fisiologia , Listeriose/enzimologia , Hepatopatias/enzimologia , Vírus da Coriomeningite Linfocítica , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/fisiologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Complexos Multienzimáticos/genética , Complexos Multienzimáticos/imunologia , Proteínas Nucleares/metabolismo , Perforina , Proteínas Citotóxicas Formadoras de Poros , Complexo de Endopeptidases do Proteassoma , Biossíntese de Proteínas , Proteínas/genética , RNA Mensageiro/biossíntese , Receptor de Interferon alfa e beta , Receptores de Interferon/genética
20.
Schweiz Med Wochenschr ; 130(47): 1820-6, 2000 Nov 25.
Artigo em Alemão | MEDLINE | ID: mdl-11130148

RESUMO

Whipple's disease has been diagnosed more frequently in recent years as a consequence of better awareness and of improved diagnostic tools. The number of case reports of Whipple's disease without gastrointestinal symptoms and without histological lesions of the intestinal mucosa is increasing. Therefore, the traditional perception of this disease as well as the methods for its diagnosis need to be revised. We report on 2 patients with Whipple's disease who had systemic inflammatory reactions but neither gastrointestinal symptoms nor an abnormal duodenal histology. Whipple's disease was diagnosed on the basis of extraintestinal tissue histology (lymph node, vertebral body) and by polymerase chain reaction, and was treated successfully with antibiotics. Recommendations for diagnostic procedure in Whipple's disease with both typical and atypical clinical presentation are discussed.


Assuntos
Doença de Whipple/diagnóstico , Doença de Whipple/patologia , Antibacterianos/uso terapêutico , Diagnóstico Diferencial , Duodeno/patologia , Humanos , Mucosa Intestinal/patologia , Linfonodos/patologia , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Coluna Vertebral/patologia , Doença de Whipple/tratamento farmacológico
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