Optical signatures of multifold fermions in the chiral topological semimetal CoSi.

We report the optical conductivity in high-quality crystals of the chiral topological semimetal CoSi, which hosts exotic quasiparticles known as multifold fermions. We find that the optical response is separated into several distinct regions as a function of frequency, each dominated by different types of quasiparticles. The low-frequency intraband response is captured by a narrow Drude peak from a high-mobility electron pocket of double Weyl quasiparticles, and the temperature dependence of the spectral weight is consistent with its Fermi velocity. By subtracting the low-frequency sharp Drude and phonon peaks at low temperatures, we reveal two intermediate quasilinear interband contributions separated by a kink at 0.2 eV. Using Wannier tight-binding models based on first-principle calculations, we link the optical conductivity above and below 0.2 eV to interband transitions near the double Weyl fermion and a threefold fermion, respectively. We analyze and determine the chemical potential relative to the energy of the threefold fermion, revealing the importance of transitions between a linearly dispersing band and a flat band. More strikingly, below 0.1 eV our data are best explained if spin-orbit coupling is included, suggesting that at these energies, the optical response is governed by transitions between a previously unobserved fourfold spin-3/2 node and a Weyl node. Our comprehensive combined experimental and theoretical study provides a way to resolve different types of multifold fermions in CoSi at different energy. More broadly, our results provide the necessary basis to interpret the burgeoning set of optical and transport experiments in chiral topological semimetals.

High Levels of Platelet-Lymphocyte Complexes in Patients with Psoriasis Are Associated with a Better Response to Anti-TNF-α Therapy.

Psoriasis is currently considered to be an immune-mediated disease whose patho-mechanisms involve platelet activation, which seems to correlate with the activity of the disease. Platelet activation is associated with the formation of platelet-lymphocyte complexes (PLyC), although their significance remains unknown. Moreover, biological treatments that target tumor necrosis factor-α (TNF-α) reduce platelet activation. To clarify the significance of PLyC, we compared their levels in patients with psoriasis with those of healthy donors and determined whether platelet binding modifies the secretion of IL-17A by T helper cells. Finally, we assessed the effect of anti-TNF-α treatment on PLyC in responder and non-responder patients with psoriasis. Ours results demonstrated an increase in PLyC in patients with psoriasis. Moreover, the percentage of IL-17-secreting cells was observed to be higher in the platelet-lymphocyte complex population, and these cells tended to secrete greater amounts of IL-17A. Psoriasis patients treated with anti-TNF-α normalized platelet-lymphocyte complex values, and the basal percentage of platelet-T helper lymphocyte complexes was significantly higher in the responder group. In conclusion, PLyC are increased in psoriasis patients, and the number of complexes decreases in response to anti-TNF-α treatment, specifically in the responder group of patients. This finding suggests that PLyC are a prognostic biomarker of response to anti-TNF-α therapy, but prospective studies are necessary to verify these results in patients with psoriasis.

Impact of the Regularization Parameter in the Mean Free Path Reconstruction Method: Nanoscale Heat Transport and Beyond.

The understanding of the mean free path (MFP) distribution of the energy carriers in materials (e.g., electrons, phonons, magnons, etc.) provides a key physical insight into their transport properties. In this context, MFP spectroscopy has become an important tool to describe the contribution of carriers with different MFP to the total transport phenomenon. In this work, we revise the MFP reconstruction technique and present a study on the impact of the regularization parameter on the MFP distribution of the energy carriers. By using the L-curve criterion, we calculate the optimal mathematical value of the regularization parameter. The effect of the change from the optimal value in the MFP distribution is analyzed in three case studies of heat transport by phonons. These results demonstrate that the choice of the regularization parameter has a large impact on the physical information obtained from the reconstructed accumulation function, and thus cannot be chosen arbitrarily. The approach can be applied to various transport phenomena at the nanoscale involving carriers of different physical nature and behavior.

Microcystic Lymphatic Malformation Successfully Treated With Topical Rapamycin.

Microcystic lymphatic malformations (MLM) are low-flow vascular malformations composed of multiple small cysts. MLM usually affect deep-lying structures, which makes their treatment even more difficult and complex. A novel and interesting treatment is rapamycin, a mammalian target of rapamycin inhibitor that when orally administrated has offered favorable results. However, until recently, topical rapamycin had not been used in the treatment of MLM. Case 1 is a girl aged 13 years with extensive MLM affecting the muscles in the right buttock. The patient had received frequent cycles of cryotherapy, but they had failed to control the associated symptoms. In the previous 12 months, the patient had reported greater discomfort, swelling, exudate, and superinfection of the affected region. Because no specific treatment has yet been approved for MLM, and as a step before the use of aggressive systemic or intralesional treatments, it was decided to initiate treatment with 1% rapamycin ointment. After 4 months of treatment, the patient presented a marked improvement, with a significant reduction of associated complications and no major side effects. Case 2 is a boy aged 5 years who underwent surgery for an intergluteal lipoblastoma at 3 weeks of life and developed a MLM on the scar 6 months afterward. The lesion showed slow growth and continuous exudation with frequent episodes of superinfection. Treatments with laser multiplex and intralesional bleomycin were performed unsuccessfully. In the previous 4 months, the patient had been treated with 1% rapamycin ointment with significant improvement and no side effects.

Hernia pulmonar / Pulmonary hernia

La hernia pulmonar o neumocele es una protrusión del pulmón a través de un defecto de la pared torácica. Es una afección infrecuente, con tan sólo unos 300 casos publicados en la bibliografía internacional 1-10 . Fue descrita por primera vez en 1499 por Roland 1 . Se realiza la presentación de un caso de hernia pulmonar adquirida traumática de un paciente masculino, blanco de 17 meses, ingresado en la terapia intensiva pediátrica del hospital Militar Central: Dr. Luis Díaz Soto por bronconeumonía complicada con derrame pleural derecho y que requirió de ventilación mecánica y pleurotomías. Se diagnosticó hernia pulmonar infraclavicular derecha como complicación de una pleurotomía alta, que como causa del proceso no se registra en la literatura revisada y que desapareció con tratamiento conservador(AU)

Hemorragia intracraneal en el niño / Intracranial hemorrhage in the child

La enfermedad cerebrovascular en neonatos, lactantes y niños es poco frecuente. Solamente representa el 2 por ciento de todos los ictus. La etiología de la enfermedad en la infancia permanece poco clara hasta en un 40 por ciento de los casos. Diversos estudios epidemiológicos muestran una incidencia de 2.7 a 7.91 ictus por 100.000 niños al año, con un índice de recurrencia del 20 por ciento. Presentamos una niña de 6 años con antecedentes de cefalea, que comenzó con un cuadro brusco de vómitos, cefalea y empeoramiento del estado de conciencia, con evolución al coma profundo, después de realizada una punción lumbar. Ingresa en la Unidad de Cuidados Intensivos Pediátricos y la tomografía axial computarizada de cráneo mostró un foco hemorrágico temporal y parietal izquierdo con desplazamiento de la línea media y con edema bilateral difuso. Evolucionó de forma tórpida hacia la disfunción múltiple de órganos y el fallecimiento. La autopsia demostró la presencia de una malformación arteriovenosa (MAV) cerebral como causa directa de la muerte(AU)