94 research outputs found

    The receptor guanylyl cyclase Npr2 is essential for sensory axon bifurcation within the spinal cord

    Get PDF
    Sensory axonal projections into the spinal cord display a highly stereotyped pattern of T- or Y-shaped axon bifurcation at the dorsal root entry zone (DREZ). Here, we provide evidence that embryonic mice with an inactive receptor guanylyl cyclase Npr2 or deficient for cyclic guanosine monophosphate-dependent protein kinase I (cGKI) lack the bifurcation of sensory axons at the DREZ, i.e., the ingrowing axon either turns rostrally or caudally. This bifurcation error is maintained to mature stages. In contrast, interstitial branching of collaterals from primary stem axons remains unaffected, indicating that bifurcation and interstitial branching are processes regulated by a distinct molecular mechanism. At a functional level, the distorted axonal branching at the DREZ is accompanied by reduced synaptic input, as revealed by patch clamp recordings of neurons in the superficial layers of the spinal cord. Hence, our data demonstrate that Npr2 and cGKI are essential constituents of the signaling pathway underlying axonal bifurcation at the DREZ and neuronal connectivity in the dorsal spinal cord

    Domain wall QCD with physical quark masses

    Full text link
    We present results for several light hadronic quantities (fπf_\pi, fKf_K, BKB_K, mudm_{ud}, msm_s, t01/2t_0^{1/2}, w0w_0) obtained from simulations of 2+1 flavor domain wall lattice QCD with large physical volumes and nearly-physical pion masses at two lattice spacings. We perform a short, O(3)%, extrapolation in pion mass to the physical values by combining our new data in a simultaneous chiral/continuum `global fit' with a number of other ensembles with heavier pion masses. We use the physical values of mπm_\pi, mKm_K and mΩm_\Omega to determine the two quark masses and the scale - all other quantities are outputs from our simulations. We obtain results with sub-percent statistical errors and negligible chiral and finite-volume systematics for these light hadronic quantities, including: fπf_\pi = 130.2(9) MeV; fKf_K = 155.5(8) MeV; the average up/down quark mass and strange quark mass in the MSˉ\bar {\rm MS} scheme at 3 GeV, 2.997(49) and 81.64(1.17) MeV respectively; and the neutral kaon mixing parameter, BKB_K, in the RGI scheme, 0.750(15) and the MSˉ\bar{\rm MS} scheme at 3 GeV, 0.530(11).Comment: 131 pages, 30 figures. Updated to match published versio

    Fermionic R-Operator and Algebraic Structure of 1D Hubbard Model: Its application to quantum transfer matrix

    Full text link
    The algebraic structure of the 1D Hubbard model is studied by means of the fermionic R-operator approach. This approach treats the fermion models directly in the framework of the quantum inverse scattering method. Compared with the graded approach, this approach has several advantages. First, the global properties of the Hamiltonian are naturally reflected in the algebraic properties of the fermionic R-operator. We want to note that this operator is a local operator acting on fermion Fock spaces. In particular, SO(4) symmetry and the invariance under the partial particle hole transformation are discussed. Second, we can construct a genuinely fermionic quantum transfer transfer matrix (QTM) in terms of the fermionic R-operator. Using the algebraic Bethe Ansatz for the Hubbard model, we diagonalize the fermionic QTM and discuss its properties.Comment: 22 pages, no figure

    Refractory and relapsed paediatric ACC in the MET studies – a challenging situation necessitating novel diagnostic and therapeutic concepts

    Get PDF
    Background Paediatric adrenocortical carcinomas (ACC) are highly aggressive malignancies with a dismal prognosis in advanced and metastatic disease. Little is known about outcome of patients with refractory and relapsed (r/r) disease. Procedure National retrospective multicentre study including r/r ACC diagnosed in patients aged <18 years registered in the MET studies between January 1997 and December 2021 Results A total of 16 patients (5 male; median age 12.9 years) with refractory disease were included. Median time to progression was 0.6 years [0.0-1.3]. Site of progression was locoregional (n=1), distant (n=3), and combined (n=12). 3-year overall (OS) and progression-free (PFS) survival were both 0%. Thirty patients with relapse (11 male; median age 7.3 years) were identified. Median time to relapse was 0.7 years [0.1-3.2]. Site of relapse was locoregional (n=8), distant (n=15), and combined (n=7). At last follow-up, 20 patients had died of disease or complications or were alive with disease, 10 patients were in second complete remission (median follow-up: 6.8 years [0-10.5]). 3-year OS and PFS following relapse were 39.1% and 31.9%. Survival was superior in patients with distant relapse (59.6%) compared to locoregional (28.6%) and combined (14.3%) (p=0.028) and in patients with complete surgical resection of all sites of recurrence (70.0%) compared to incomplete (21.4%) and no surgery (0%) (p=0.003). Conclusions For patients nonresponsive to first-line therapy or who experience relapse, prognosis is dismal and options are scarce. Site of relapse and resectability define prognosis. Novel therapeutic concepts are needed to improve the outcome of paediatric patients with r/r ACC

    Early diagnosis is associated with improved clinical outcomes in benign esophageal perforation: an individual patient data meta‑analysis

    Get PDF
    Background Time of diagnosis (TOD) of benign esophageal perforation is regarded as an important risk factor for clinical outcome, although convincing evidence is lacking. The aim of this study is to assess whether time between onset of perforation and diagnosis is associated with clinical outcome in patients with iatrogenic esophageal perforation (IEP) and Boerhaave’s syndrome (BS). Methods We searched MEDLINE, Embase and Cochrane library through June 2018 to identify studies. Authors were invited to share individual patient data and a meta-analysis was performed (PROSPERO: CRD42018093473). Patients were subdivided in early (≤ 24 h) and late (> 24 h) TOD and compared with mixed effects multivariable analysis while adjusting age, gender, location of perforation, initial treatment and center. Primary outcome was overall mortality. Secondary outcomes were length of hospital stay, re-interventions and ICU admission. Results Our meta-analysis included IPD of 25 studies including 576 patients with IEP and 384 with BS. In IEP, early TOD was not associated with overall mortality (8% vs. 13%, OR 2.1, 95% CI 0.8–5.1), but was associated with a 23% decrease in ICU admissions (46% vs. 69%, OR 3.0, 95% CI 1.2–7.2), a 22% decrease in re-interventions (23% vs. 45%, OR 2.8, 95% CI 1.2–6.7) and a 36% decrease in length of hospital stay (14 vs. 22 days, p < 0.001), compared with late TOD. In BS, no associations between TOD and outcomes were found. When combining IEP and BS, early TOD was associated with a 6% decrease in overall mortality (10% vs. 16%, OR 2.1, 95% CI 1.1–3.9), a 19% decrease in re-interventions (26% vs. 45%, OR 1.9, 95% CI 1.1–3.2) and a 35% decrease in mean length of hospital stay (16 vs. 22 days, p = 0.001), compared with late TOD. Conclusions This individual patient data meta-analysis confirms the general opinion that an early (≤ 24 h) compared to a late diagnosis (> 24 h) in benign esophageal perforations, particularly in IEP, is associated with improved clinical outcome.publishedVersio

    Tenacidad a la fractura de compuestos cermets 3Al2O3*2SiO2/Ag manufacturados por molienda de alta energĂ­a

    Get PDF
    La fabricación de materiales compuestos de matriz cerámica reforzados con partículas metálicas han propiciado la formación de nuevos materiales conocidos como compuestos CERMETS, materiales que debido a sus elementos precursores poseen propiedades distintas a las de los materiales convencionales. En este trabajo se establece la ruta de fabricación de materiales compuestos cermets base 3Al2O3*2SiO2 reforzados con partículas metálicas de Ag a partir de la formación de la composición química en peso de polvos de 3Al2O3*2SiO2 / 1% Ag en busca de un aumento en la tenacidad a la fractura con respecto al cerámico base. La composición química de polvos es sometida a un proceso de mezcla molienda de alta energía en seco en un molino tipo planetario por 2 horas a 200 rpm. Los polvos posteriormente son conformados en muestras cilíndricas de 20 mm de diámetro y 3 mm de espesor mediante la aplicación de carga uniaxial en frío de 200 MPa. Las muestras son sinterizadas a 1500°C y 1600°C por una y dos horas en un horno de resistencia eléctrica en atmósfera controlada de gas nitrógeno. Los compuestos fabricados son analizados microestructuralmente por microscopia óptica y electrónica de barrido. Se determina la densidad y las propiedades mecánicas de dureza y tenacidad a la fractura, las dos últimas por el método de indentación. Los resultados muestran la viabilidad de fabricación de materiales compuestos cermets así como los cambios en la densidad, la dureza y la tenacidad a la fractura, con respecto al cerámico 3Al2O3*2SiO2 sin refuerzo metálico

    Early diagnosis is associated with improved clinical outcomes in benign esophageal perforation: an individual patient data meta-anal

    Get PDF
    Background: Time of diagnosis (TOD) of benign esophageal perforation is regarded as an important risk factor for clinical outcome, although convincing evidence is lacking. The aim of this study is to assess whether time between onset of perforation and diagnosis is associated with clinical outcome in patients with iatrogenic esophageal perforation (IEP) and Boerhaave’s syndrome (BS). Methods: We searched MEDLINE, Embase and Cochrane library through June 2018 to identify studies. Authors were invited to share individual patient data and a meta-analysis was performed (PROSPERO: CRD42018093473). Patients were subdivided in early (≤ 24 h) and late (> 24 h) TOD and compared with mixed effects multivariable analysis while adjusting age, gender, location of perforation, initial treatment and center. Primary outcome was overall mortality. Secondary outcomes were length of hospital stay, re-interventions and ICU admission. Results: Our meta-analysis included IPD of 25 studies including 576 patients with IEP and 384 with BS. In IEP, early TOD was not associated with overall mortality (8% vs. 13%, OR 2.1, 95% CI 0.8–5.1), but was associated with a 23% decrease in ICU admissions (46% vs. 69%, OR 3.0, 95% CI 1.2–7.2), a 22% decrease in re-interventions (23% vs. 45%, OR 2.8, 95% CI 1.2–6.7) and a 36% decrease in length of hospital stay (14 vs. 22 days, p 24 h) in benign esophageal perforations, particularly in IEP, is associated with improved clinical outcome
    • …
    corecore