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The superconductor PdTe2 is known to host bulk Dirac bands and topological surface states. The coexistence of superconductivity and topological surface states makes PdTe2 a promising platform for exploring topological superconductivity and Majorana bound states. In this work, we report the spectroscopic characterization of ultrathin PdTe2 films with thickness down to three monolayers (ML). In the 3 ML PdTe2 film, we observed spin-polarized surface resonance states, which are isolated from the bulk bands due to the quantum size effects. In addition, the hybridization of surface states on opposite faces leads to a thickness-dependent gap in the topological surface Dirac bands. Our photoemission results show clearly that the size of the hybridization gap increases as the film thickness is reduced. The observation of isolated surface resonances and gapped topological surface states sheds light on the applications of PdTe2 quantum films in spintronics and topological quantum computation.
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INTRODUCTION: Cyclosporine therapy for Stevens-Johnson syndrome-toxic epidermal necrolysis (SJSTEN) was first reported in the literature by Renfro et al. in 1989. Herein we report an additional 4 cases of SJS-TEN treated with cyclosporine. METHODS: Case information was collected retroactively at the University of Louisville Hospital in Louisville, KY. All cases had a diagnosis of SJS or TEN by a dermatologist. All patients were ≥18 years of age and treated with cyclosporine during their admission. RESULTS: Three of four patients re-epithelialized within an average of 3.67 days of starting 3-4 mg/kg/day of cyclosporine. One patient passed away, likely due to advanced endometrial cancer. DISCUSSION: We provide a review of the literature on cyclosporine use for SJS/TEN, including various outcome measures - stabilization (cessation of new lesions), time to re-epithelialization, mortality rate, and hospital length of stay and, where available, comparison to other systemic agents. CONCLUSION: The outcomes appear to be consistent with rapid re-epithelialization and low mortality as seen in many previous reports. Treating SJS-TEN with systemic agents including cyclosporine will remaincontroversial because the vast majority of data comes from case reports, case series, or small open prospective trials.
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Inhibidores de la Calcineurina/uso terapéutico , Ciclosporina/uso terapéutico , Síndrome de Stevens-Johnson/tratamiento farmacológico , Adulto , Anciano , Antiinflamatorios/uso terapéutico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios RetrospectivosRESUMEN
Our laboratory has recently demonstrated that low concentrations of ouabain increase blood pressure in rats associated with stimulation of NaK ATPase activity and activation of the Src signaling cascade in NHE1-dependent manner. Proteomic analysis of human kidney proximal tubule cells (HKC11) suggested that the Angiotensin II type 1 receptor (AT1R) as an ouabain-associating protein. We hypothesize that ouabain-induced stimulation of NaK ATPase activity is mediated through AT1R. To test this hypothesis, we examined the effect of ouabain on renal cell angiotensin II production, the effect of AT1R inhibition on ouabain-stimulated NKA activity, and the effect of ouabain on NKA-AT1R association. Ouabain increased plasma angiotensin II levels in rats treated with ouabain (1µg/kg body wt./day) for 9days and increased angiotensin II levels in cell culture media after 24h treatment with ouabain in human (HKC11), mouse (MRPT), and human adrenal cells. Ouabain 10pM stimulated NKA-mediated 86Rb uptake and phosphorylation of EGFR, Src, and ERK1/2. These effects were prevented by the AT1R receptor blocker candesartan. FRET and TIRF microscopy using Bodipy-labeled ouabain and mCherry-NKA or mCherry-AT1R demonstrated association of ouabain with AT1R and NKA. Further our FRET and TIRF studies demonstrated increased association between AT1R and NKA upon treatment with low dose ouabain. We conclude that ouabain stimulates NKA in renal proximal tubule cells through an angiotensin/AT1R-dependent mechanism and that this pathway contributes to cardiac glycoside associated hypertension.
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Activadores de Enzimas/farmacología , Túbulos Renales Proximales/efectos de los fármacos , Ouabaína/farmacología , Receptor de Angiotensina Tipo 1/metabolismo , ATPasa Intercambiadora de Sodio-Potasio/metabolismo , Angiotensina II/metabolismo , Bloqueadores del Receptor Tipo 1 de Angiotensina II/farmacología , Angiotensinógeno/metabolismo , Animales , Línea Celular , Relación Dosis-Respuesta a Droga , Activación Enzimática , Activadores de Enzimas/toxicidad , Hipertensión/inducido químicamente , Hipertensión/enzimología , Túbulos Renales Proximales/enzimología , Ratones , Ouabaína/toxicidad , Peptidil-Dipeptidasa A/metabolismo , Fosforilación , Unión Proteica , Ratas Sprague-Dawley , Receptor de Angiotensina Tipo 1/genética , Transducción de Señal/efectos de los fármacos , ATPasa Intercambiadora de Sodio-Potasio/genética , TransfecciónRESUMEN
2D van der Waals (vdW) magnets open landmark horizons in the development of innovative spintronic device architectures. However, their fabrication with large scale poses challenges due to high synthesis temperatures (>500 °C) and difficulties in integrating them with standard complementary metal-oxide semiconductor (CMOS) technology on amorphous substrates such as silicon oxide (SiO2) and silicon nitride (SiNx). Here, a seeded growth technique for crystallizing CrTe2 films on amorphous SiNx/Si and SiO2/Si substrates with a low thermal budget is presented. This fabrication process optimizes large-scale, granular atomic layers on amorphous substrates, yielding a substantial coercivity of 11.5 kilo-oersted, attributed to weak intergranular exchange coupling. Field-driven Néel-type stripe domain dynamics explain the amplified coercivity. Moreover, the granular CrTe2 devices on Si wafers display significantly enhanced magnetoresistance, more than doubling that of single-crystalline counterparts. Current-assisted magnetization switching, enabled by a substantial spin-orbit torque with a large spin Hall angle (85) and spin Hall conductivity (1.02 × 107 â/2e Ω⻹ m⻹), is also demonstrated. These observations underscore the proficiency in manipulating crystallinity within integrated 2D magnetic films on Si wafers, paving the way for large-scale batch manufacturing of practical magnetoelectronic and spintronic devices, heralding a new era of technological innovation.
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A two-dimensional (2D) Weyl semimetal, akin to a spinful variant of graphene, represents a topological matter characterized by Weyl fermion-like quasiparticles in low dimensions. The spinful linear band structure in two dimensions gives rise to distinctive topological properties, accompanied by the emergence of Fermi string edge states. We report the experimental realization of a 2D Weyl semimetal, bismuthene monolayer grown on SnS(Se) substrates. Using spin and angle-resolved photoemission and scanning tunneling spectroscopies, we directly observe spin-polarized Weyl cones, Weyl nodes, and Fermi strings, providing consistent evidence of their inherent topological characteristics. Our work opens the door for the experimental study of Weyl fermions in low-dimensional materials.
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Patients with human immunodeficiency virus (HIV) infection exhibit changes in sleep patterns, motor disorders, and cognitive dysfunction; these symptoms may be secondary to circadian rhythm abnormalities. Studies in mice have shown that intracerebral injection of an HIV protein, transactivator of transcription (Tat), alters the timing of circadian rhythms in a manner similar to light. Therefore, we tested the hypothesis that chronic Tat expression alters circadian rhythms, especially their entrainment to a light-dark (LD) cycle, by using transgenic mice in which Tat expression in the brain was induced via a doxycycline (DOX)-sensitive, glial fibrillary-associated, protein-restricted promoter. Because opiate substance abuse, which shares comorbidity with HIV infection, also disrupts sleep, a final experiment assessed the effects of morphine exposure on circadian rhythms in wild-type and Tat transgenic mice. Mice housed in cages equipped with running wheels were fed chow with or without DOX. Experiment 1 revealed a small but significant (P < 0.05) difference between groups in the phase angle of entrainment and a 15% decrease in the wheel running in the DOX group (P < 0.005). During exposure to constant darkness, DOX did not alter the endogenous period length of the circadian rhythm. Experiment 2 investigated the effect of DOX on circadian rhythms in wild-type and Tat(+) mice during exposure to a normal or phase-shifted LD cycle, or morphine treatment without any change in the LD cycle. Tat induction significantly decreased wheel running but did not affect entrainment to the normal or shifted LD cycle. Morphine decreased wheel running without altering the phase angle of entrainment, and the drug's effects were independent of Tat induction. In conclusion, these findings suggest that chronic brain expression of Tat decreases locomotor activity and the amplitude of circadian rhythms, but does not affect photic entrainment or reentrainment of the murine circadian pacemaker.