Lymphome Cérébral Primitif (LCP) du Sujet Immunocompétent: A Propos d’Un cas à l’Hôpital National de Niamey (HNN)

Le Lymphome Cérébral Primitif (LCP) du sujet immunocompétent est une entité rare des lymphomes Non Hodgkiniens en général et des tumeurs cérébrales en particulier. Il est caractérisé par sa sévérité clinique, mais aussi son mauvais pronostic. Nous rapportons un cas de LCP chez un sujet immunocompétent diagnostiqué au service de neurologie et pris en charge au service d’Onco-hématologie de l’Hôpital National de Niamey.   Primary Cerebral Lymphoma (PCL) of the immunocompetent subject is a rare feature of non-Hodgkin's lymphoma in general and brain tumors in particular. It is characterized by its clinical severity, but also its poor prognosis. We report a case of LCP in an immunocompetent subject diagnosed in the neurology department and managed by Onco-hematology at the National Hospital of Niamey

Lymphome Cérébral Primitif (LCP) du Sujet Immunocompétent: A Propos d’Un cas à l’Hôpital National de Niamey (HNN)

Le Lymphome Cérébral Primitif (LCP) du sujet immunocompétent est une entité rare des lymphomes Non Hodgkiniens en général et des tumeurs cérébrales en particulier. Il est caractérisé par sa sévérité clinique, mais aussi son mauvais pronostic. Nous rapportons un cas de LCP chez un sujet immunocompétent diagnostiqué au service de neurologie et pris en charge au service d’Onco-hématologie de l’Hôpital National de Niamey.   Primary Cerebral Lymphoma (PCL) of the immunocompetent subject is a rare feature of non-Hodgkin's lymphoma in general and brain tumors in particular. It is characterized by its clinical severity, but also its poor prognosis. We report a case of LCP in an immunocompetent subject diagnosed in the neurology department and managed by Onco-hematology at the National Hospital of Niamey

Clinical and experimental aspects of aneurysmal subarachnoid hemorrhage

Aneurysmal subarachnoid hemorrhage (aSAH) continues to be associated with significant morbidity and mortality despite advances in care and aneurysm treatment strategies. Cerebral vasospasm continues to be a major source of clinical worsening in patients. We intended to review the clinical and experimental aspects of aSAH and identify strategies that are being evaluated for the treatment of vasospasm. A literature review on aSAH and cerebral vasospasm was performed. Available treatments for aSAH continue to expand as research continues to identify new therapeutic targets. Oral nimodipine is the primary medication used in practice given its neuroprotective properties. Transluminal balloon angioplasty is widely utilized in patients with symptomatic vasospasm and ischemia. Prophylactic “triple‐H” therapy, clazosentan, and intraarterial papaverine have fallen out of practice. Trials have not shown strong evidence supporting magnesium or statins. Other calcium channel blockers, milrinone, tirilazad, fasudil, cilostazol, albumin, eicosapentaenoic acid, erythropoietin, corticosteroids, minocycline, deferoxamine, intrathecal thrombolytics, need to be further investigated. Many of the current experimental drugs may have significant roles in the treatment algorithm, and further clinical trials are needed. There is growing evidence supporting that early brain injury in aSAH may lead to significant morbidity and mortality, and this needs to be explored further.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151874/1/cns13222_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151874/2/cns13222.pd

Nernst and Seebeck Coefficients of the Cuprate SuperconductorYBa2_2Cu3_3O6.67_{6.67}: A Study of Fermi Surface Reconstruction

The Seebeck and Nernst coefficients $S$ and $\nu$ of the cuprate superconductor YBa$_2$Cu$_3$O$_y$ (YBCO) were measured in a single crystal with doping $p = 0.12$ in magnetic fields up to H = 28 T. Down to T=9 K, $\nu$ becomes independent of field by $H \simeq 30$ T, showing that superconducting fluctuations have become negligible. In this field-induced normal state, $S/T$ and $\nu/T$ are both large and negative in the $T \to 0$ limit, with the magnitude and sign of $S/T$ consistent with the small electron-like Fermi surface pocket detected previously by quantum oscillations and the Hall effect. The change of sign in $S(T)$ at $T \simeq 50$ K is remarkably similar to that observed in La$_{2-x}$Ba$_x$CuO$_4$, La$_{2-x-y}$Nd$_y$Sr$_x$CuO$_4$ and La$_{2-x-y}$Eu$_y$Sr$_x$CuO$_4$, where it is clearly associated with the onset of stripe order. We propose that a similar density-wave mechanism causes the Fermi surface reconstruction in YBCO.Comment: Final version accepted for publication in Phys. Rev. Lett. New title, shorter abstract, minor revision of text and added reference

Geriatric in Patient Profile at the Department of Internal Medicine at Niamey National Hospital, Niger

Background: The ageing population in developing countries has brought a demographic and an epidemiological transition, with the impact of chronic diseases resulting from life style changes on the health status of the population. Objective: To describ a profile geriatrics patient, specifically to identify epidemiologic, clinical, etiologic and outcome of this group at the department of internal medicine to NNH Patients and method: Medical records of all geriatric patients aged ≥65 years admitted at the department of NNH Between January 2012 and December 2015 were retrieved and reviewed retrospectively. Results: A total of 6074 admissions at the internal medicine department of NNH over three years were reported and 1130 (18, 6%) were geriatrics patients, the average age was 75, 95 years and more than half were men (50,7%). 80 % of patients were in the young old group (65-74 years), 13% in the old group (75-84 years) and 7% in the oldest old group (≥85 years). High blood pressure was the frequent comorbidity (12, 3%) and the most symptoms caused hospitalization were stroke (17, 6%), fevers (16, 5%) and worst health (13, 1%). Frequent illnesses were cardiovascular diseases (38.4%), infections, (19.2%) and endocrine diseases (11%). The average length of hospital stays was 8, 7 days. The mortality rate was 18, 2% and the worst outcomes factors were female sex, frail elderly group in 75 to 84 years and high blood pressure. Conclusion: Chronic diseases were responsible of morbidity and mortality for the majority elderly’s patient

Lifshitz critical point in the cuprate superconductor YBa2Cu3Oy from high-field Hall effect measurements

The Hall coefficient R_H of the cuprate superconductor YBa2Cu3Oy was measured in magnetic fields up to 60 T for a hole concentration p from 0.078 to 0.152, in the underdoped regime. In fields large enough to suppress superconductivity, R_H(T) is seen to go from positive at high temperature to negative at low temperature, for p > 0.08. This change of sign is attributed to the emergence of an electron pocket in the Fermi surface at low temperature. At p < 0.08, the normal-state R_H(T) remains positive at all temperatures, increasing monotonically as T \to 0. We attribute the change of behaviour across p = 0.08 to a Lifshitz transition, namely a change in Fermi-surface topology occurring at a critical concentration p_L = 0.08, where the electron pocket vanishes. The loss of the high-mobility electron pocket across p_L coincides with a ten-fold drop in the conductivity at low temperature, revealed in measurements of the electrical resistivity $\rho$ at high fields, showing that the so-called metal-insulator crossover of cuprates is in fact driven by a Lifshitz transition. It also coincides with a jump in the in-plane anisotropy of $\rho$, showing that without its electron pocket the Fermi surface must have strong two-fold in-plane anisotropy. These findings are consistent with a Fermi-surface reconstruction caused by a unidirectional spin-density wave or stripe order.Comment: 16 pages, 13 figures, see associated Viewpoint: M. Vojta, Physics 4, 12 (2011

Enhancement of the Nernst effect by stripe order in a high-Tc superconductor

The Nernst effect in metals is highly sensitive to two kinds of phase transition: superconductivity and density-wave order. The large positive Nernst signal observed in hole-doped high-Tc superconductors above their transition temperature Tc has so far been attributed to fluctuating superconductivity. Here we show that in some of these materials the large Nernst signal is in fact caused by stripe order, a form of spin / charge modulation which causes a reconstruction of the Fermi surface. In LSCO doped with Nd or Eu, the onset of stripe order causes the Nernst signal to go from small and negative to large and positive, as revealed either by lowering the hole concentration across the quantum critical point in Nd-LSCO, or lowering the temperature across the ordering temperature in Eu-LSCO. In the latter case, two separate peaks are resolved, respectively associated with the onset of stripe order at high temperature and superconductivity near Tc. This sensitivity to Fermi-surface reconstruction makes the Nernst effect a promising probe of broken symmetry in high-Tc superconductors

Magnetostriction and magnetic texture to 97.4 Tesla in frustrated SrCu2(BO3)2

Strong geometrical frustration in magnets leads to exotic states, such as spin liquids, spin supersolids and complex magnetic textures. SrCu2(BO3)2, a spin-1/2 Heisenberg antiferromagnet in the archetypical Shastry-Sutherland lattice, exhibits a rich spectrum of magnetization plateaus and stripe-like magnetic textures in applied fields. The structure of these plateaus is still highly controversial due to the intrinsic complexity associated with frustration and competing length scales. We reveal new magnetic textures in SrCu2(BO3)2 via magnetostriction and magnetocaloric measurements in fields up to 97.4 Tesla. In addition to observing the low-field fine structure of the plateaus with unprecedented resolution, the data also reveal lattice responses at 82 T and at 73.6 T which we attribute, using a controlled density matrix renormalization group approach, to the long-predicted 1/2-saturation plateau, and to a new 2/5 plateau.Comment: 12 pages, 4 figures, submitte

Broken rotational symmetry in the pseudogap phase of a high-Tc superconductor

The nature of the pseudogap phase is a central problem in the quest to understand high-Tc cuprate superconductors. A fundamental question is what symmetries are broken when that phase sets in below a temperature T*. There is evidence from both polarized neutron diffraction and polar Kerr effect measurements that time- reversal symmetry is broken, but at temperatures that differ significantly. Broken rotational symmetry was detected by both resistivity and inelastic neutron scattering at low doping and by scanning tunnelling spectroscopy at low temperature, but with no clear connection to T*. Here we report the observation of a large in-plane anisotropy of the Nernst effect in YBa2Cu3Oy that sets in precisely at T*, throughout the doping phase diagram. We show that the CuO chains of the orthorhombic lattice are not responsible for this anisotropy, which is therefore an intrinsic property of the CuO2 planes. We conclude that the pseudogap phase is an electronic state which strongly breaks four-fold rotational symmetry. This narrows the range of possible states considerably, pointing to stripe or nematic orders.Comment: Published version. Journal reference and DOI adde

Technology for NASA's Planetary Science Vision 2050.

NASAs Planetary Science Division (PSD) initiated and sponsored a very successful community Workshop held from Feb. 27 to Mar. 1, 2017 at NASA Headquarters. The purpose of the Workshop was to develop a vision of planetary science research and exploration for the next three decades until 2050. This abstract summarizes some of the salient technology needs discussed during the three-day workshop and at a technology panel on the final day. It is not meant to be a final report on technology to achieve the science vision for 2050