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1.
Phys Rev Lett ; 131(19): 196702, 2023 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-38000423

RESUMO

The V-based kagome systems AV_{3}Sb_{5} (A=Cs, Rb, and K) are unique by virtue of the intricate interplay of nontrivial electronic structure, topology, and intriguing fermiology, rendering them to be a playground of many mutually dependent exotic phases like charge-order and superconductivity. Despite numerous recent studies, the interconnection of magnetism and other complex collective phenomena in these systems has yet not arrived at any conclusion. Using first-principles tools, we demonstrate that their electronic structures, complex fermiologies and phonon dispersions are strongly influenced by the interplay of dynamic electron correlations, nontrivial spin-polarization and spin-orbit coupling. An investigation of the first-principles-derived intersite magnetic exchanges with the complementary analysis of q dependence of the electronic response functions and the electron-phonon coupling indicate that the system conforms as a frustrated spin cluster, where the occurrence of the charge-order phase is intimately related to the mechanism of electron-phonon coupling, rather than the Fermi-surface nesting.

2.
Int J Dermatol ; 60(2): 208-216, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33502780

RESUMO

BACKGROUND: Targeted therapies and immunotherapies are increasingly prescribed, but classic chemotherapy agents are still highly used in cancer treatment. Both therapies, the old and the new, are associated with cutaneous adverse events (CAEs) that can cause treatment interruptions or reduce the quality of life of patients. METHODS: An observational, cross-sectional, single-center study that included consecutive cancer patients presenting CAEs. The main objective was to describe CAEs derived from antineoplastic drugs. Secondary objectives were to determine the number and severity of CAEs and if there were differences regarding CAEs between conventional chemotherapeutics and targeted therapies. RESULTS: A total of 114 patients were included with a total number of 177 CAEs. Of the 114 patients, 64 presented a single CAE, 37 patients had two CAEs, and 13 patients presented three CAEs. The most frequent CAEs were pruritus, xerosis, palmar-plantar erythrodysesthesia (PPE), and alopecia. The majority of CAEs were mild (63.2%), followed by moderate (29.9%) and severe (6.7%) CAEs. Of the 114 patients, 103 (90.3%) received topical agents and 11 (9.7%) required systemic treatment for the management of CAEs. Prophylactic treatment for CAE was delivered to only 4/114 (3.5%) patients. No significant differences were found in the number or severity of CAEs between conventional chemotherapy and targeted therapy. CONCLUSIONS: Close collaboration between oncologists and dermatologists is essential to start preventive measures on time, enhance patient education, and avoid unnecessary dose reductions or treatment interruptions. The multidisciplinary approach can offer better management of skin toxicities.


Assuntos
Antineoplásicos , Toxidermias , Idoso , Antineoplásicos/efeitos adversos , Antineoplásicos Imunológicos/efeitos adversos , Estudos Transversais , Toxidermias/etiologia , Feminino , Humanos , Imunoterapia/efeitos adversos , Masculino , Pessoa de Meia-Idade , Qualidade de Vida , Centros de Atenção Terciária
5.
J Phys Condens Matter ; 30(37): 375801, 2018 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-30079893

RESUMO

In magnetic materials, nontrivial spin textures may emerge due to the competition among different types of magnetic interactions. Among such spin textures, chiral magnetic solitons represent topologically protected spin configurations with particle-like properties. Based on atomistic spin dynamics simulations, we demonstrate that these chiral magnetic solitons are ideal to use for logical operations, and we demonstrate the functionality of a three-input majority gate, in which the input states can be controlled by applying an external electromagnetic field or spin-polarized currents. One of the main advantages of the proposed device is that the input and output signals are encoded in the chirality of solitons, that may be moved, allowing to perform logical operations using only minute electric currents. As an example we illustrate how the three input majority gate can be used to perform logical relations, such as Boolean AND and OR.

6.
Sci Rep ; 7(1): 931, 2017 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-28424483

RESUMO

An essential property of magnetic devices is the relaxation rate in magnetic switching which strongly depends on the energy dissipation. This is described by the Landau-Lifshitz-Gilbert equation and the well known damping parameter, which has been shown to be reproduced from quantum mechanical calculations. Recently the importance of inertia phenomena have been discussed for magnetisation dynamics. This magnetic counterpart to the well-known inertia of Newtonian mechanics, represents a research field that so far has received only limited attention. We present and elaborate here on a theoretical model for calculating the magnetic moment of inertia based on the torque-torque correlation model. Particularly, the method has been applied to bulk itinerant magnets and we show that numerical values are comparable with recent experimental measurements. The theoretical analysis shows that even though the moment of inertia and damping are produced by the spin-orbit coupling, and the expression for them have common features, they are caused by very different electronic structure mechanisms. We propose ways to utilise this in order to tune the inertia experimentally, and to find materials with significant inertia dynamics.

7.
J Phys Condens Matter ; 29(2): 025807, 2017 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-27841998

RESUMO

We report on the electronic structure, magnetic moments and exchange interactions of one- and two-dimensional Cr clusters on a Pd(1 1 1) substrate, using a real-space method based on density functional theory in the local spin density approximation. We find in general that for the investigated clusters, the magnetic moments are sizeable and almost entirely of spin-character. We demonstrate that the interactions in general are dominated by nearest-neighbor antiferromagnetic Heisenberg form, which implies that Cr on Pd(1 1 1) forms an ideal model system, in which clusters of almost any shape and size can be investigated from a Heisenberg Hamiltonian, using a nearest-neighbor exchange model. We have also found that complex magnetic structures can be realized for linear chains of Cr, due to a competition between exchange interaction and a weaker Dzyaloshinskii-Moriya interaction.

8.
Dermatol Clin ; 33(3): 331-41, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26143417

RESUMO

Actinic granuloma and annular elastolytic giant cell granuloma are different terms used to define skin lesions characterized by elastolysis, elastophagocytosis, and multinucleated giant cell infiltrate. The clinical appearance varies from papules to annular plaques. Although elastolytic actinic giant cell granuloma shares some clinical features with granuloma annulare, they can be differentiated by histopathologic findings. The disease is initiated by an immune response triggered by different factors that alter the elastic tissue. The course tends to be chronic, with variable response to treatments, although spontaneous remission may occur. Diabetes mellitus is the systemic disease most frequently associated with this condition.


Assuntos
Tecido Elástico/patologia , Granuloma de Células Gigantes/patologia , Transtornos de Fotossensibilidade/patologia , Pele/patologia , Diabetes Mellitus/epidemiologia , Granuloma de Células Gigantes/epidemiologia , Humanos , Transtornos de Fotossensibilidade/epidemiologia
10.
Dermatol Ther ; 28(6): 346-50, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26088022

RESUMO

Xanthelasma are cholesterol-filled, soft, yellow plaques that usually appear on the medial aspects of the eyelids bilaterally. They are always benign lesions so therapy is usually undertaken only for cosmetic reasons. Surgical excision, chemical peeling with tricholoroacetic acid, and laser ablation are commonly used treatments. Liquid nitrogen cryotherapy is a potentially effective but rarely used treatment due to the risk of intense eyelid swelling. We report on our experience with four of our patients, and propose an explanation for the effectiveness of gentle liquid nitrogen spray cryotherapy in xanthelasma. We consider that gentle liquid nitrogen cryotherapy should be used in the treatment of xanthelasma due to the ease of application and low risk of adverse effects.


Assuntos
Criocirurgia/métodos , Doenças Palpebrais/cirurgia , Nitrogênio/uso terapêutico , Xantomatose/cirurgia , Administração Cutânea , Aerossóis , Criocirurgia/efeitos adversos , Doenças Palpebrais/diagnóstico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nitrogênio/administração & dosagem , Nitrogênio/efeitos adversos , Resultado do Tratamento , Xantomatose/diagnóstico
11.
Nat Commun ; 5: 4815, 2014 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-25198354

RESUMO

Chirality--that is, left or right handedness--is present in many scientific areas, and particularly in condensed matter physics. Inversion symmetry breaking relates chirality with skyrmions, which are protected field configurations with particle-like and topological properties. Here we show that a kagome magnet, with Heisenberg and Dzyaloshinskii-Moriya interactions, causes non-trivial topological and chiral magnetic properties. We also find that under special circumstances, skyrmions emerge as excitations, having stability even at room temperature. Chiral magnonic edge states of a kagome magnet offer, in addition, a promising way to create, control and manipulate skyrmions. This has potential for applications in spintronics, that is, for information storage or as logic devices. Collisions between these particle-like excitations are found to be elastic at very low temperature in the skyrmion-skyrmion channel, albeit without mass-conservation. Skyrmion-antiskyrmion collisions are found to be more complex, where annihilation and creation of these objects have a distinct non-local nature.

12.
Mycoses ; 54(5): 450-3, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20406389

RESUMO

There are few reports studying the aetiology of onychomycosis in children in Spain. To study childhood dermatophyte onychomycosis, a retrospective study of children was carried out, who were <16 years of age with dermatophyte onychomycosis diagnosed between 1987 and 2007. Of 4622 nail samples from 3550 patients, 218 came from 181 children up to 16 years old. Onychomycosis caused by dermatophytes was demonstrated in 28 (15.5%) cases. Trichophyton rubrum (18 cases) was the most prevalent species, followed by Trichophyton tonsurans (five cases), Trichophyton mentagrophytes var. interdigitale (four cases) and Trichophyton mentagrophytes var. mentagrophytes (one case). Concomitant dermatophytosis at other locations was confirmed in seven cases (25%). Toenail onychomycosis was associated with tinea pedis in five cases. Distal and lateral subungual onychomycosis was the most common clinical pattern. The superficial white type was found in two cases of toenail onychomycosis caused by T. rubrum and T. tonsurans. During the period of study, only 5.1% of all investigated people were children up to 16 years. The prevalence of onychomycosis tended to increase over the years and represented 15.5% of all nail dystrophies in children. Therefore, dermatologists must consider onychomycosis in the differential diagnosis of nail alterations in children and always perform a mycological study to confirm the diagnosis.


Assuntos
Arthrodermataceae/isolamento & purificação , Onicomicose/epidemiologia , Adolescente , Arthrodermataceae/classificação , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Estudos Retrospectivos , Espanha/epidemiologia
13.
Acta Derm Venereol ; 87(5): 422-4, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17721650

RESUMO

Fusarium spp. are emergent opportunistic moulds capable of producing life-threatening diseases, usually in immunocompromised hosts. When they infect immunocompetent patients, they usually cause localized diseases. We describe here a case of cutaneous fusariosis in a patient with a medical history of diabetes mellitus and non-Hodgkin's lymphoma who presented with two painful lesions on her left leg. The diagnosis was made on the basis of histopathological findings and skin biopsy culture. The lesions resolved after treatment with oral itraconazole. Cutaneous fusariosis manifests clinically as lesions that can be grouped into a few clinical patterns, and should always be considered in the differential diagnosis of necrotic cutaneous lesions.


Assuntos
Dermatomicoses/diagnóstico , Úlcera da Perna/microbiologia , Idoso , Antifúngicos/uso terapêutico , Biópsia , Dermatomicoses/tratamento farmacológico , Diabetes Mellitus , Feminino , Fusarium , Humanos , Itraconazol/uso terapêutico , Úlcera da Perna/tratamento farmacológico , Linfoma não Hodgkin , Pele/patologia
14.
Actas Dermosifiliogr ; 97(2): 126-30, 2006 Mar.
Artigo em Espanhol | MEDLINE | ID: mdl-16595115

RESUMO

Cryoglobulins are serum immunoglobulins that precipitate reversibly when the serum is cooled below 371 degrees C. In cryoglobulinemic syndrome, a multitude of organs can be involved, but many patients suffer from a moderate, chronic disease consisting of palpable purpura, arthralgia and fatigue. Skin involvement is especially useful in aiding early recognition of this entity. We present four patients with cryoglobulinemic syndrome and skin lesions, in whom it was not possible to find an etiological or associated factor. We discuss the etiopathogenesis, clinical and pathological findings, treatment and prognosis of this entity.


Assuntos
Crioglobulinemia/complicações , Dermatoses Faciais/etiologia , Dermatoses do Pé/etiologia , Úlcera do Pé/etiologia , Vasculite Leucocitoclástica Cutânea/etiologia , Corticosteroides/uso terapêutico , Adulto , Idoso de 80 Anos ou mais , Terapia Combinada , Crioglobulinemia/diagnóstico , Crioglobulinemia/tratamento farmacológico , Desbridamento , Dermatoses Faciais/tratamento farmacológico , Feminino , Dermatoses do Pé/tratamento farmacológico , Úlcera do Pé/tratamento farmacológico , Úlcera do Pé/cirurgia , Humanos , Imunossupressores/uso terapêutico , Perna (Membro) , Pessoa de Meia-Idade , Prurido/tratamento farmacológico , Prurido/etiologia , Recidiva , Síndrome , Vasculite Leucocitoclástica Cutânea/tratamento farmacológico
16.
Actas dermo-sifiliogr. (Ed. impr.) ; 97(2): 126-130, mar. 2006. ilus, tab
Artigo em Es | IBECS | ID: ibc-043560

RESUMO

Las crioglobulinas son inmunoglobulinas séricas que tienen la propiedad de precipitar de forma reversible cuando el suero es enfriado por debajo de los 37 °C. En el síndrome crioglobulinémico se pueden afectar multitud de órganos pero muchos de los pacientes sufren una enfermedad moderada y crónica consistente en púrpura palpable, artralgias y fatiga. La afectación cutánea es de especial utilidad ya que puede ayudar al reconocimiento precoz de esta entidad. Presentamos 4 pacientes con síndrome crioglobulinémico y lesiones cutáneas en los cuales no fue posible encontrar un factor etiológico o asociado. Se discute la etiopatogenia, los hallazgos clinicopatológicos, tratamiento y pronóstico de esta entidad


Cryoglobulins are serum immunoglobulins that precipitate reversibly when the serum is cooled below 371ºC. In cryoglobulinemic syndrome, a multitude of organs can be involved, but many patients suffer from a moderate , chronic disease consisting of palpable purpura, arthralgia and fatigue. Skin involvement is especially useful in aiding early recognition of this entity. We present four patients with cryoglobulinemic syndrome and skin lesions, in whom it was not possible to find an etiological or associated factor. We discuss the etiopathogenesis, clinical and pathological findings, treatment and prognosis of this entity (AU)


Assuntos
Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Humanos , Crioglobulinemia/diagnóstico , Crioglobulinemia/terapia , Vasculite/diagnóstico , Fator Reumatoide/análise , Técnica Direta de Fluorescência para Anticorpo/métodos , Anti-Inflamatórios não Esteroides/uso terapêutico , Mupirocina/uso terapêutico , Corticosteroides/uso terapêutico , Prednisona/uso terapêutico , Úlcera Cutânea/diagnóstico , Crioglobulinas/análise , Vasculite/complicações , Anticorpos Antinucleares/análise , Hepatite C/complicações , Transtornos Linfoproliferativos/diagnóstico , Imunoeletroforese/métodos , Úlcera Cutânea/complicações , Úlcera do Pé/complicações , Úlcera do Pé/diagnóstico , Úlcera do Pé/terapia
19.
Actas dermo-sifiliogr. (Ed. impr.) ; 95(5): 295-297, jun. 2004. ilus
Artigo em Es | IBECS | ID: ibc-33391

RESUMO

Se presenta el caso de un paciente varón de 42 años con una lesión tumoral en labio superior cuyo estudio dermatopatológico fue compatible con el diagnóstico de linfocitoma cutáneo. Dado el fracaso de la terapéutica local previa empleada, se administró cloroquina en dosis de 500 mg/día, que indujo la remisión de la lesión. Destacamos la capacidad inmunomoduladora de los antipalúdicos de síntesis en un caso en el que los corticoides locales no fueron efectivos. (AU)


Assuntos
Adulto , Masculino , Humanos , Cloroquina/uso terapêutico , Metilprednisolona/uso terapêutico , Anti-Inflamatórios/uso terapêutico , Doenças Labiais/tratamento farmacológico , Doenças Labiais/patologia , Pseudolinfoma/tratamento farmacológico , Pseudolinfoma/patologia
20.
Dermatol Surg ; 30(4 Pt 1): 517-20, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15056141

RESUMO

BACKGROUND: Controversy exists as to whether treatment of actinic keratoses with intermittent doses of topical 5-fluorouracil is effective in the absence of significant irritation. OBJECTIVE: To evaluate the efficacy and degree of irritation of 5-fluorouracil as a function of its application frequency. METHODS: A total of 85 actinic keratoses in 53 patients were treated, initially with four applications per week for the first week. After this first week, if intolerable irritation arose, patients were instructed to reduce application frequency to two times per week for the rest of the treatment period. RESULTS: Treatment was completed for 95.4% of the lesions included, with healing of 88.6% of them. The mean time to healing was 7.4 weeks (with four applications weekly) and 10.2 weeks (with two applications). The healing rate was similar in the two groups. Significant correlations (p<0.001) were observed between application frequency and time to healing. CONCLUSION: Intermittent 5-fluorouracil treatment is effective without causing significant irritation, but time to healing increases with declining application frequency.


Assuntos
Fluoruracila/administração & dosagem , Imunossupressores/administração & dosagem , Ceratose/tratamento farmacológico , Administração Tópica , Adulto , Idoso , Esquema de Medicação , Toxidermias/etiologia , Fluoruracila/efeitos adversos , Humanos , Imunossupressores/efeitos adversos , Ceratose/etiologia , Pessoa de Meia-Idade , Fatores de Tempo , Resultado do Tratamento , Raios Ultravioleta/efeitos adversos , Cicatrização/efeitos dos fármacos
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