1,130 research outputs found
Importance of Residual Water Permeability on the Excretion of Water during Water Diuresis in Rats
When the concentration of sodium (Na+) in arterial plasma (PNa) declines sufficiently to inhibit the release of vasopressin, water will be excreted promptly when the vast majority of aquaporin 2 water channels (AQP2) have been removed from luminal membranes of late distal nephron segments. In this setting, the volume of filtrate delivered distally sets the upper limit on the magnitude of the water diuresis. Since there is an unknown volume of water reabsorbed in the late distal nephron, our objective was to provide a quantitative assessment of this parameter. Accordingly, rats were given a large oral water load, while minimizing non-osmotic stimuli for the release of vasopressin. The composition of plasma and urine were measured. The renal papilla was excised during the water diuresis to assess the osmotic driving force for water reabsorption in the inner medullary collecting duct. During water diuresis, the concentration of creatinine in the urine was 13-fold higher than in plasma, which implies that ~8% of filtered water was excreted. The papillary interstitial osmolality was 600 mOsm/L > the urine osmolality. Since 17% of filtered water is delivered to the earliest distal convoluted tubule micropuncture site, we conclude that half of the water delivered to the late distal nephron is reabsorbed downstream during water diuresis. The enormous osmotic driving force for the reabsorption of water in the inner medullary collecting duct may play a role in this reabsorption of water. Possible clinical implications are illustrated in the discussion of a case example
Radio propagation measurements and modeling for standardization of the site general path loss model in International Telecommunications Union recommendations for 5G wireless networks
The International Telecommunications Union Radiocommunication Sector (ITU‐R) Study Group 3 identified the need for a number of radio channel models in anticipation of the World Radiocommunications Conference in 2019 when the frequency allocation for 5G will be discussed. In response to the call for propagation path loss models, members of the study group carried out measurements in the frequency bands between 0.8 GHz up to 73 GHz in urban low rise and urban high rise as well as suburban environments. The data were subsequently merged to generate site general path loss models. The paper presents an overview of the radio channel measurements, the measured environments, the data analysis and the approach for the derivation of the path loss model adopted in Recommendation ITU‐R P.1411‐10
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Management of lupus nephritis: a systematic literature review informing the 2019 update of the joint EULAR and European Renal Association-European Dialysis and Transplant Association (EULAR/ERA-EDTA) recommendations.
OBJECTIVES: To analyse the current evidence for the management of lupus nephritis (LN) informing the 2019 update of the EULAR/European Renal Association-European Dialysis and Transplant Association recommendations. METHODS: According to the EULAR standardised operating procedures, a PubMed systematic literature review was performed, from January 1, 2012 to December 31, 2018. Since this was an update of the 2012 recommendations, the final level of evidence (LoE) and grading of recommendations considered the total body of evidence, including literature prior to 2012. RESULTS: We identified 387 relevant articles. High-quality randomised evidence supports the use of immunosuppressive treatment for class III and class IV LN (LoE 1a), and moderate-level evidence supports the use of immunosuppressive treatment for pure class V LN with nephrotic-range proteinuria (LoE 2b). Treatment should aim for at least 25% reduction in proteinuria at 3 months, 50% at 6 months and complete renal response (<500-700 mg/day) at 12 months (LoE 2a-2b). High-quality evidence supports the use of mycophenolate mofetil/mycophenolic acid (MMF/MPA) or low-dose intravenous cyclophosphamide (CY) as initial treatment of active class III/IV LN (LoE 1a). Combination of tacrolimus with MMF/MPA and high-dose CY are alternatives in specific circumstances (LoE 1a). There is low-quality level evidence to guide optimal duration of immunosuppression in LN (LoE 3). In end-stage kidney disease, all methods of kidney replacement treatment can be used, with transplantation having the most favourable outcomes (LoE 2b). CONCLUSIONS: There is high-quality evidence to guide the initial and subsequent phases of class III/IV LN treatment, but low-to-moderate quality evidence to guide treatment of class V LN, monitoring and optimal duration of immunosuppression
Anti-cancer drug validation: the contribution of tissue engineered models
Abstract Drug toxicity frequently goes concealed until clinical trials stage, which is the most challenging, dangerous and expensive stage of drug development. Both the cultures of cancer cells in traditional 2D assays and animal studies have limitations that cannot ever be unraveled by improvements in drug-testing protocols. A new generation of bioengineered tumors is now emerging in response to these limitations, with potential to transform drug screening by providing predictive models of tumors within their tissue context, for studies of drug safety and efficacy. Considering the NCI60, a panel of 60 cancer cell lines representative of 9 different cancer types: leukemia, lung, colorectal, central nervous system (CNS), melanoma, ovarian, renal, prostate and breast, we propose to review current Bstate of art^ on the 9 cancer types specifically addressing the 3D tissue models that have been developed and used in drug discovery processes as an alternative to complement their studyThis article is a result of the project FROnTHERA (NORTE-01-0145-FEDER-000023), supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). This article was also supported by the EU Framework Programme for Research and Innovation HORIZON 2020 (H2020) under grant agreement n° 668983 — FoReCaST. FCT distinction attributed to Joaquim M. Oliveira (IF/00423/2012) and Vitor M. Correlo (IF/01214/2014) under the Investigator FCT program is also greatly acknowledged.info:eu-repo/semantics/publishedVersio
2017 HRS/EHRA/ECAS/APHRS/SOLAECE expert consensus statement on catheter and surgical ablation of atrial fibrillation: executive summary.
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A CO funnel in the Galactic centre: molecular counterpart of the northern Galactic chimney
We report the discovery of a velocity coherent, funnel-shaped 13CO emission feature in the Galactic centre (GC) using data from the SEDIGISM survey. The molecular cloud appears as a low-velocity structure (VLSR = [ − 3.5, + 3.5] km s−1) with an angular extent of 0.95° ×1°, extending towards positive Galactic latitudes. The structure is offset from Sgr A* towards negative Galactic longitudes; it spatially and morphologically correlates well with the northern lobe of the 430 pc radio bubble, believed to be the radio counterpart of the multiwavelength GC chimney. Spectral line observations in the frequency range of 85–116 GHz have been carried out using the IRAM 30-m telescope towards 12 positions along the funnel-shaped emission. We examine the 12C/13C isotopic ratios using various molecules and their isotopologues. The mean 12C/13C isotope ratio (30.6 ± 2.9) is consistent with the structure located within inner 3 kpc of the Galaxy and possibly in the GC. The velocity of the molecular funnel is consistent with previous radio recombination line measurements of the northern lobe of radio bubble. Our multiwavelength analysis suggests that the funnel-shaped structure extending over 100 pc above the Galactic plane is the molecular counterpart of the northern GC chimney
2017 HRS/EHRA/ECAS/APHRS/SOLAECE expert consensus statement on catheter and surgical ablation of atrial fibrillation: executive summary.
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Analog reservoir computing via ferroelectric mixed phase boundary transistors.
Analog reservoir computing (ARC) systems have attracted attention owing to their efficiency in processing temporal information. However, the distinct functionalities of the system components pose challenges for hardware implementation. Herein, we report a fully integrated ARC system that leverages material versatility of the ferroelectric-to-mixed phase boundary (MPB) hafnium zirconium oxides integrated onto indium-gallium-zinc oxide thin-film transistors (TFTs). MPB-based TFTs (MPBTFTs) with nonlinear short-term memory characteristics are utilized for physical reservoirs and artificial neuron, while nonvolatile ferroelectric TFTs mimic synaptic behavior for readout networks. Furthermore, double-gate configuration of MPBTFTs enhances reservoir state differentiation and state expansion for physical reservoir and processes both excitatory and inhibitory pulses for neuronal functionality with minimal hardware burden. The seamless integration of ARC components on a single wafer executes complex real-world time-series predictions with a low normalized root mean squared error of 0.28. The material-device co-optimization proposed in this study paves the way for the development of area- and energy-efficient ARC systems
A CO Funnel in the Galactic Centre: Molecular Counterpart of the Northern Galactic Chimney?
We report the discovery of a velocity coherent, funnel shaped ^13CO emission
feature in the Galactic centre (GC) using data from the SEDIGISM survey. The
molecular cloud appears as a low velocity structure (V_LSR=[-3.5, +3.5] km/s)
with an angular extent of 0.95{\deg} x 1{\deg}, extending toward positive
Galactic latitudes. The structure is offset from Sgr A* toward negative
Galactic longitudes and spatially and morphologically correlates well with the
northern lobe of the 430 pc radio bubble, believed to be the radio counterpart
of the multiwavelength GC chimney. Spectral line observations in the frequency
range of 85-116 GHz have been carried out using the IRAM 30 metre telescope
toward 12 positions along the funnel-shaped emission. We examine the ^12C/^13C
isotopic ratios using various molecules and their isotopologues. The mean
^12C/^13C isotope ratio (30.6+-2.9) is consistent with the structure located
within inner 3 kpc of the Galaxy and possibly in the GC. The velocity of the
molecular funnel is consistent with previous radio recombination line
measurements of the northern lobe of radio bubble. Our multiwavelength analysis
suggests that the funnel shaped structure extending over 100 pc above the
Galactic plane is the molecular counterpart of the northern GC chimney.Comment: Accepted for publication in A&A Letter
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