Sodium Profile Research Articles

The effect of ascending- descending ultrafiltration and sodium profiles on blood pressure in hemodialysis patients: a randomized cross-over study

BackgroundConsidering no previous research into the utilization of ascending/descending ultrafiltration and linear sodium profiles in improving blood pressure among hemodialysis patients, the present study aimed to explore the effect of the A/D-UF along with linear sodium profiles on HD patients with hypotension.MethodsApplying a crossover design, this clinical trial was fulfilled between December 2022 and June 2023 on 20 patients undergoing HD, randomized into two groups, each one receiving two intervention protocols, viz., (a) an intervention protocol in which the liquid sodium in the dialysis solution was linear and the UF profiling was A/D, and (b) a routine protocol or HD, wherein both liquid sodium and UF in the dialysis solution remained constant. The HD patients’ BP was then checked and recorded at six intervals, namely, before HD, one, two, three, and four hours after it, and following its completion, within each session. The data were further statistically analyzed using the IBM SPSS Statistics 20 and the related tests.ResultsIn total, 20 patients, including 12 men (60%) and 8 women (40%), with the mean age of 58.00 ± 14.54 on HD for an average of 54 months, were recruited in this study. No statistically significant difference was observed in the mean systolic and diastolic BP levels in the group receiving the A/D-UF profile all through the desired hours (p > 0.05), indicating that the patients did not face many changes in these two numbers during HD. Our cross-over clinical trial demonstrated a statistically significant reduction in symptomatic IDH episodes from 55 to 15% with the application of the A/D-UF profile (p < 0.05).ConclusionThe study demonstrated that the A/D-UF profile could contribute to the stability of blood pressure levels among HD patients, with no significant fluctuations observed during treatment sessions.Trial RegistrationThis study was registered in the Iranian Registry of Clinical Trials (no. IRCT20180429039463N5) on 07/01/2023.

Simultaneous sodium profile estimation and LGS SH-WFS pixel processing optimization using LGS sub-aperture images

Image displacement pixel processing for laser guide star (LGS) Shack–Hartmann wavefront sensors (WFS) is often based upon a center of gravity with thresholding [thresholded CoG (tCoG)] algorithm. This method yields a nearly linear response to the sub-aperture wavefront gradient, but suffers from zero-point biases due to sodium profile variability and the resulting changes in the shape of the LGS sub-aperture images. This effect interacts with additional biases due to the image truncation caused by the limited field of view of the WFS sub-apertures, as well as from WFS non-common path aberration (NCPA). Natural guide star (NGS) truth wavefront sensors (TWFS) have been proposed to correct for the resulting aberrations in the reconstructed wave-front, and multiple such TWFS would be required to control anisoplanatism effects when there are multiple LGS. We describe a novel algorithm that estimates the sodium profile from time averaged sub-aperture images of one or multiple LGS using a system imaging model. This estimate can then be used to correct for the zero-point bias by adjusting the tCoG reference vector. This eliminates the need for an NGS TWFS to detect sodium profile induced aberrations, and a single TWFS with faint NGS would then be sufficient to monitor any variations in NCPA if needed, which greatly improves the sky coverage. The reconstructed sodium profile can also be used to build constrained matched filters, a noise-optimal alternative to tCoG that requires accurate knowledge of the sub-aperture LGS images and their spatial derivatives (and has yet to be demonstrated on sky). This new sodium profile reconstruction algorithm consequently eliminates the need for dithering LGS spots on sky to determine these derivatives, which greatly simplifies the implementation of matched filtering and also provides better performance. All of the necessary sodium profile estimation, bias computations, and matched filter optimizations can be done with a modern CPU (e.g., Intel Core i7-11700) at around a 0.1-Hz update rate as a background process for the real time controller. Our simulations of this new method are for center launch LGS, but we are confident the profile estimation algorithm will work equally well if not better for side launch LGS, even when there is increased image truncation.

Automated adjustment of dialysate sodium by the hemodialysis monitor: Rationale, implementation, and clinical benefits.

Prescribing dialysate sodium is the responsibility of the physician, but there are currently no clear guidelines for this prescription. Furthermore, there is quite frequently a significant difference between prescribed and measured dialysate sodium. Several arguments, both theoretical and experimental, suggest that dialysate sodium should be adjusted individually in such a way as to result in a decreasing sodium profile that takes into account the patient's predialytic natremia. The generalization in clinical routine of this strategy requires the integration into the hemodialysis monitor of software making the machine capable to automatically adjust the dialysate sodium at each session. The only three such softwares that have been integrated into hemodialysis machines for routine clinical use are discussed. All three work with conductivity measurements as a surrogate for sodium concentrations. Although there are only a few publications on the use of these softwares in clinical practice, they appear to result in improved intradialytic tolerance to the dialysis treatment, better control of hypertension, and reduced thirst, leading to decreased interdialytic weight gain.

Comparison of mesospheric sodium profile retrievals from OSIRIS and SCIAMACHY nightglow measurements

Abstract. Sodium airglow is generated when excited sodium atoms emit electromagnetic radiation while they are relaxing from an excited state into a lower energetic state. This electromagnetic radiation, the two sodium D lines at 589.0 and 589.6 nm, can usually be detected from space or from ground. Sodium nightglow occurs at times when the sun is not present and excitation of sodium atoms is a result of chemical reaction with ozone. The detection of sodium nightglow can be a means to determine the amount of sodium in the earth's mesosphere and lower thermosphere (MLT). In this study, we present time series of monthly mean sodium concentration profiles, by utilizing the large spatial and temporal coverage of satellite sodium D-line nightglow measurements. We use the OSIRIS/Odin mesospheric limb measurements to derive sodium concentration profiles and vertical column densities and compare those to measurements from SCIAMACHY/Envisat and GOMOS/Envisat. Here we show that the Na D-line limb emission rate (LER) and volume emission rate (VER) profiles calculated from the OSIRIS and SCIAMACHY measurements, although the OSIRIS LER and VER profiles are around 25 % lower, agree very well in shape and overall seasonal variation. The sodium concentration profiles also agree in shape and magnitude, although those do not show the clear semi-annual cycle which is present in the LER and VER profiles. The comparison to the GOMOS sodium vertical column densities (VCDs) shows that the OSIRIS VCDs are of the same order of magnitude although again the semi-annual cycle is not as clear. We attribute the differences in the LER, VER and sodium profiles to the differences in spatial coverage between the OSIRIS and SCIAMACHY measurements, the lower signal-to-noise ratio (SNR) of the SCIAMACHY measurements and differences in local time between the measurements of the two satellites.

Post‐mortem analysis of a commercial Copper Indium Gallium Diselenide (CIGS) photovoltaic module after potential induced degradation

AbstractAn extensive post‐mortem analysis was conducted on a commercial copper‐(indium‐gallium)‐diselenide (CIGS) photovoltaic module that degraded after exposure to the high voltage stress of a standardized potential induced degradation (PID) test. We employed a custom‐developed coring technique to extract samples from the full‐size field module, which showed degraded and nondegraded areas (regarded as reference) in electroluminescence after the PID test. The resulting solar cell samples were compared based on their electrical properties and sodium profiles using a wide range of laboratory‐based analysis techniques including photoluminescence and lock‐in thermography imaging, current–voltage measurements, and glow discharge optical emission spectroscopy. The samples that were extracted from the degraded areas of the module showed lower photoluminescence intensity and had significantly lower open‐circuit voltage V(oc) and fill factor (FF) values in comparison with reference samples. An increased content of sodium within the absorber layer was also observed for these samples, linking sodium migration to PID. These observations at the module level are consistent with earlier reports on PID‐stressed CIGS cells and mini‐modules. This is to our knowledge the first reported study of a microscopic investigation on a real‐life full‐scale CIGS module after PID.

Intraocular Pressure Changes during Hemodiafiltration with Two different Concentrations of Sodium in the Dialysate.

Simple SummaryAn increase in intraocular pressure during chronic hemodialysis is linked to ocular complications, such as glaucoma. The behavior of intraocular pressure during hemodiafiltration is unknown. Changes in intraocular pressure with a sodium dialysate concentration fixed at 138 mmol/L and an individualized concentration were studied in 13 patients with end-stage renal disease treated with hemodiafiltration. Up to 31% patients presented an episode of intraocular hypertension without differences between sodium profiles. A large variability in intraocular pressure within patients and a high prevalence of transient intraocular hypertension were found.Ocular complications are common among end-stage renal disease patients and some complications had been linked to increments of intraocular pressure (IOP) during hemodialysis. The changes of IOP during hemodiafiltration (HDF) have been scarcely investigated and the potential influence of the sodium dialysate concentration is unknown. The aim of this study was to compare the IOP changes during HDF with sodium dialysate concentration, either fixed or individualized. Thirteen end-stage renal disease patients participated in the study; they were treated with HDF using a dialysate sodium profile fixed at 138 mmol and another session with an individualized sodium profile. The intraocular pressure was measured before and after each session and every 30 min during HDF. Both groups had a similar HDF prescription, blood pressure, and biochemical parameters. At the end of hemodiafiltration, sodium concentration decreased only in the fixed sodium profile group. The number of patients with at least an episode of intraocular hypertension during HDF ranged from 5 (19%) to 8 (31%) without significant differences between right and left eye nor between dialysate sodium concentration. During HDF, there is a large variability of IOP; transient events of intraocular hypertension are highly prevalent in this sample, and they are not related to the sodium dialysate concentration.

Identifikasi Tipe Dehidrasi dan Profil Elektrolit Mayor pada Pasien Kucing di Rumah Sakit Hewan Prof. Soeparwi dan Beberapa Klinik Hewan di Wilayah Yogyakarta

Dehydration is defined as a lack of body fluids followed by loss of electrolytes, and changes in acid-base balance. The type of dehydration is limited based on the concentration of sodium in serum at the time of dehydration. Maintenance of osmotic pressure and distribution of several compartments of body fluids are the main functions of the four major electrolytes, namely sodium (Na +), potassium (K +), chloride (Cl‾), and bicarbonate (HCO3‾). Sodium is the most cation in extracellular fluid, most potassium cation in intracellular fluid and chloride is the most anion in extracellular fluid. The purpose of this study was to identify the type of dehydration and to determine the major electrolyte profile in cats in Yogyakarta and its surroundings. This study used 18 sick cats that were thought to be dehydrated, marked by decreased skin turgor, CRT&gt; 2 seconds, and 12 cats that were suspected of having electrolyte balance disorders with symptoms of ascites, uropoetic disorders. Blood was drawn for all cats to measure Pack Cells Volume (PCV) levels. Patient clinical data and patient diagnosis were recorded, cats with changes in serum PCV levels were separated for examination of levels of sodium, chloride, potassium using Seamaty SMT-120V. The type of dehydration is identified based on the sodium level in the serum of a dehydrated cat. The results showed that most of the cat patients were dehydrated had low serum sodium levels (hyponatremia). There was 1 cat patient had low chloride levels. Potassium levels in cats with UT obstruction increased, which led to a decrease in the Na: K ratio. Cat bicarbonate levels did not show any change. From the results of the study it was concluded that dehydration in cats at Prof. Soeparwi is hypotonic dehydration (71%). The sodium profile mostly decreased, chloride and bicarbonate levels did not change, while there were changes in potassium levels in patients with UT disorders. The advice given is to check electrolytes before doing fluid therapy. Prior to electrolyte testing, dehydrated cats can be given a sodium solution.

Effects of addition of swine skin on the technological characteristics of mortadella produced in an industrial unit

The aim of this work was to evaluate the effects of the addition of swine skin on the technological characteristics of mortadella formulations produced on industrial scale. The effects of concentrations of swine skin (1.5 to 5.5 %) and sodium chloride (2 to 3 %) on total protein, total fat, starch, moisture, water activity, sodium, pH and texture profile (hardness, adhesiveness, elasticity, cohesiveness and chewiness) were evaluated and compared to a mortadella formulation without swine skin addition. The mortadella formulations with addition of 3.5 to 5.5 % swine skin and 2 to 2.5 % sodium chloride are in accordance with Brazilian legislation and provided an increase of approximately 12 % in protein content, a decrease of 14 % in sodium content and a water activity less than 0.9488. The swine skin and sodium chloride provided stability to the mortadella and influenced its texture, mainly in hardness, elasticity and chewiness.

A Prospective Cohort Study on Serum Sodium and Clinical Outcome in Pediatric Nontraumatic Coma.

To study the serum sodium level and clinical outcome in pediatric nontraumatic coma. A prospective cohort study was conducted in a tertiary care pediatric intensive care unit (PICU) from September 2015 to June 2016. Children aged < 13 y with nontraumatic coma [modified-Glasgow Coma Scale (m-GCS) score ≤ 8 or fall of ≥ 3 from baseline within 24h of admission] were included. Children who received intravenous fluids for > 24h, those with developmental delay, or died within 24h of admission were excluded. The serum sodium profile (mEq/L) in the first 72h and clinical outcome [mortality, length of stay in mechanical ventilation, PICU, and hospital] were studied. Eighty patients [Died n = 26 and Survived n = 54] were enrolled. Median [interquartile range (IQR)] age and m-GCS were 21 (4-78) mo and 9 (7-11), respectively. The mean [standard deviation (SD)] Pediatric Risk of Mortality-III (PRISM-III) was 17.7 (4). The most common etiology was acute central nervous system (CNS) infections (30%, n = 24) followed by an intracranial bleed (11.3%, n = 9). Mean (Standard error, SE) sodium levels and fluctuation of serum sodium from baseline up to 72h were similar between nonsurvivors and survivors [140.8 (1.3) vs. 139.6 (0.8), p = 0.421] and [1.2 (0.3) vs. 0.8 (0.2), p = 0.307], respectively. On multivariate analysis, the need for vasoactive therapy was an independent predictor of mortality [adjusted odds ratio = 20.78, 95% CI 4.24-101.85, p = < 0.001, R2 = 0.62]. Mean serum sodium within normal range and fluctuation of serum sodium of 0.8 to 1.2mEq/L over 72h was not associated with poor outcomes in pediatric nontraumatic coma. Vasoactive therapy was an independent predictor of mortality.

Retrieval of mesospheric sodium from OSIRIS nightglow measurements and comparison to ground-based Lidar measurements

The understanding of the excitation mechanism of the sodium D-line nightglow emission is important for many investigations of atomic sodium in the upper mesosphere region. In 1939, Sidney Chapman proposed a first scheme of the chemical reactions involving sodium and ozone to explain the yellow sodium line doublet in the terrestrial nightglow. Later, it became clear that this mechanism could not explain the observed variability in the Na D-line ratio. Hence, Slanger et al. (2005) suggested a modified Chapman mechanism. However, it is well accepted that there is still a parameter that is not well quantified, i.e., the branching ratio fA that defines how many sodium atoms are produced (via the reaction Na + O3) in the excited Na(P2J) state. Here, we retrieve sodium profiles in the mesosphere region from limb measurements carried out with the OSIRIS instrument on the Odin satellite between 2002 and until recently. These profiles are compared to profiles obtained from ground-based Lidar measurements. Until 2010, the Lidar was located in Fort Collins, Colorado at 40.5° N and 105.0° W and was then moved to Logan, Utah at 41.8° N and 111.2° W. In this study, we found 20 nights with measurements suitable for comparison. By adjusting the branching ratio in the retrieval algorithm until the Lidar Na-profile and the satellite Na-profile agree best and combining the three different approaches for the comparison we propose a value of the branching ratio of: 0.064±0.028.

Assessment of Cu(In, Ga)Se2 Solar Cells Degradation due to Water Ingress Effect on The CdS Buffer Layer

The effect of water ingress on the surface of the buffer layer of a Cu(In, Ga)Se2 (CIGS) solar cell was studied. Such degradation can occur either during the fabrication process, if it involves a chemical bath as is often the case for CdS, or while the modules are in the field and encapsulants degrade. To simulate the impact of this moisture ingress, devices with a structure sodalime glass/Mo/CIGS/CdS were immersed in deionized water. The thin films were then analyzed both pre and post water soaking. Dynamic secondary ion mass spectroscopy (SIMS) was performed on completed devices to analyze impurity diffusion (predominantly sodium and potassium) and to assess potential degradation mechanisms. The results were compared to device measurements, which indicate a degradation of all device parameters due to an increase in the total and peak trap densities, as shown by simulation. This is potentially due to a modification of the sodium profile in the bulk CIGS, with a decrease content after water soaking or because the oxygen profile increased in the bulk CIGS after water soaking.

Characterization and release profile of sodium diclofenac halal hard shell capsules made from k-carrageenan and xanthan gum with sorbitol plasticizer

Halal hard shell capsules are importantly needed by Indonesian consumers, who are predominantly Muslim, to substitute mostly used and commercially available products made from non-halal ingredients such as gelatin. The objective of this study is to prepare, characterize, and evaluate halal hard shell capsules made from k-carrageenan-xanthan gum with sorbitol as the plasticizer with diclofenac sodium as the model drug. Hardshell capsules were prepared with combinations of κ-carrageenan-xanthan gum at a weight ratio of 4:2 with the addition of 70% sorbitol, which added at a varied volume of 0.25; 0.50; 0.75; and 1.00 mL. Characterization of halal hard shell capsules includes swelling degree, tensile strength, Fourier Transformed Infrared (FTIR) and Scanning Electron Microscope (SEM), as well as disintegration test. The diclofenac sodium profile release was evaluated through the dissolution test at pH 6.8. The best physical characteristics were obtained by preparing capsule shells with a mixture of carrageenan-xanthan gum at a weight ratio of 4:2 with the addition of 0.25 mL sorbitol. The evaluation of Halal hard shell capsules showed that it had a swelling rate of 3.46% in water media, stress modulus of 28.6 MPa, strain modulus of 4.3 MPa, and modulus young of 362,3%, as well as disintegration time of capsules, was 51.8 minutes at pH 6.8. The dissolution test showed that diclofenac sodium was released at a level of 2.7% for 16 minutes. Based on this data, it can be concluded that the Halal hard shell capsule of κ-carrageenan-xanthan gum with the addition of sorbitol can be used as an alternative for the gelatin capsule with more controlled release.

Serum Sodium Profile of Congestive Heart Failure Patients and its Impact on Their Outcome at Discharge.

IntroductionPatients with congestive heart failure (CHF) readily present with electrolyte imbalance which commonly includes deficiencies of sodium, potassium, and magnesium. Hyponatremia occurs in advanced stages of CHF and is associated with adverse disease outcome-longer hospital stay, severity of CHF, and increased risk of mortality.MethodsIn this observational, single-center, prospective, case-control study adult patients admitted with clinical diagnosis of CHF were included after informed consent. Their demographic, clinical, and biochemical profile was attained. Patients with low serum sodium (hyponatremia) were grouped as "cases" and patients with normal serum sodium profile (normonatremia) were grouped as "controls". Factors associated with both groups and their hospital outcome were compared. SPSS for Windows version 16 (SPSS Inc., Chicago, IL, USA) was utilized.ResultsHyponatremia (serum sodium <135 mmol/L) was present in 58/189 (30.7%) patients admitted with CHF. Younger patients with non-ischemic CHF, and history of previous diagnosis, treatment, and hospitalization due to CHF were more likely to be affected. Diabetic nephropathy, chronic kidney disease, salt-restricted diet, drugs including furosemide, spironolactone, and angiotensin-converting enzyme inhibitors, low serum potassium, and reduced GFR were also related to hyponatremia. Hyponatremic CHF patients showed adverse hospital outcome on all parameters including higher death rate (12% vs. 0.8%), longer duration of hospital day, and deranged blood pressures and severe CHF at the time of discharge.ConclusionHyponatremic CHF patients are associated with prolonged hospital stay, more severe form of CHF, and deranged blood pressures. Overall, hyponatremia is an indirect clinical indicator of circulatory dysfunction and should guide a clinician for closer observation as outcomes could be poor. These patients also have higher in-hospital mortality risk.

Dynamical structure of the pulsating atmosphere of RR Lyrae

Context. RRab stars are large amplitude pulsating stars in which the pulsation wave is a progressive wave. Consequently, strong shocks, stratification effects, and phase lag may exist between the variations associated with line profiles formed in different parts of the atmosphere, including the shock wake. The pulsation is associated with a large extension of the expanding atmosphere, and strong infalling motions are expected. Aims. The objective of this study is to provide a general overview of the dynamical structure of the atmosphere occurring over a typical pulsation cycle. Methods. We report new high-resolution observations with high time resolution of Hα and sodium lines in the brightest RR Lyrae star of the sky: RR Lyr (HD 182989). A detailed analysis of line profile variations over the whole pulsation cycle is performed to understand the dynamical structure of the atmosphere. Results. The main shock wave appears when it exits from the photosphere at φ ≃ 0.89, i.e., when the main Hα emission is observed. Whereas the acceleration phase of the shock is not observed, a significant deceleration of the shock front velocity is clearly present. The radiative stage of the shock wave is short: 4% of the pulsation period (0.892 &lt; φ &lt; 0.929). A Mach number M &gt; 10 is required to get such a radiative shock. The sodium layer reaches its maximum expansion well before that of Hα (Δφ = 0.135). Thus, a rarefaction wave is induced between the Hα and sodium layers. A strong atmospheric compression occurring around φ = 0.36, which produces the third Hα emission, takes place in the highest part of the atmosphere. The region located lower in the atmosphere where the sodium line is formed is not involved. The amplification of gas turbulence seems mainly due to strong shock waves propagating in the atmosphere rather than to the global compression of the atmosphere caused by the pulsation. It has not yet been clearly established whether the microturbulence velocity increases or decreases with height in the atmosphere. Furthermore, it seems very probable that an interstellar component is visible within the sodium profile.

Comparison of global datasets of sodium densities in the mesosphere and lower thermosphere from GOMOS, SCIAMACHY and OSIRIS measurements and WACCM model simulations from 2008 to 2012

Abstract. During the last decade, several limb sounding satellites have measured the global sodium (Na) number densities in the mesosphere and lower thermosphere (MLT). Datasets are now available from Global Ozone Monitoring by Occultation of Stars (GOMOS), the SCanning Imaging Absorption spectroMeter for Atmospheric CHartography (SCIAMACHY) (both on Envisat) and the Optical Spectrograph and InfraRed Imager System (OSIRIS) (on Odin). Furthermore, global model simulations of the Na layer in the MLT simulated by the Whole Atmosphere Community Climate Model, including the Na species (WACCM-Na), are available. In this paper, we compare these global datasets.The observed and simulated monthly averages of Na vertical column densities agree reasonably well with each other. They show a clear seasonal cycle with a summer minimum most pronounced at the poles. They also show signs of a semi-annual oscillation in the equatorial region. The vertical column densities vary from 0. 5 × 109 to 7 × 109 cm−2 near the poles and from 3 × 109 to 4 × 109 cm−2 at the Equator. The phase of the seasonal cycle and semi-annual oscillation shows small differences between the Na amounts retrieved from different instruments. The full width at half maximum of the profiles is 10 to 16 km for most latitudes, but significantly smaller in the polar summer. The centroid altitudes of the measured sodium profiles range from 89 to 95 km, whereas the model shows on average 2 to 4 km lower centroid altitudes. This may be explained by the mesopause being 3 km lower in the WACCM simulations than in measurements. Despite this global 2–4 km shift, the model captures well the latitudinal and temporal variations. The variation of the WACCM dataset during the year at different latitudes is similar to the one of the measurements. Furthermore, the differences between the measured profiles with different instruments and therefore different local times (LTs) are also present in the model-simulated profiles. This capturing of latitudinal and temporal variations is also found for the vertical column densities and profile widths.

The prognostic significance of serum sodium in a population undergoing cardiac resynchronisation therapy

PurposeTo determine the prognostic implications of changes towards hyponatremia at varying time-points in the treatment of patients undergoing cardiac resynchronisation therapy (CRT). MethodsA retrospective series of 249 patients was studied from 2002 to 2013. The population was categorized on the basis of serum sodium profile at baseline, at 1 month and at 6 month follow up visits following successful CRT implantation. The composite endpoint was all-cause mortality and heart failure hospitalisation (defined by the need for intravenous diuretic therapy) following CRT implantation. ResultsA total of 249 patients (67.8±12.5 years; NYHA class III/IV 75; LVEF 27.2±8.8%) were followed up for a median of 5.5 years. Hyponatremia at baseline, 1 month or 6 months follow up did not predict the composite endpoint. 26% of patients showed hyponatremia at baseline prior to CRT implantation, while it was present in 19.9% of patients 1 month (p=0.003) and in 16% (p<0.001) 6 months after CRT implantation. There was a significantly worse outcome for those patients who developed hyponatremia 6 months after CRT implantation. In multivariate analysis, the intake of loop diuretics (HR 1.76 [1.04–2.95], p=0.03) and renal impairment (urea>7.0mmol/l) (HR 1.61 [1.05–2.46], p=0.03) at baseline were associated with an increased risk of unplanned heart failure hospitalisation and all-cause mortality after CRT implantation. ConclusionsA change towards hyponatremia when observed 6 months after CRT implantation may predict a worse clinical outcome. Additionally, renal impairment and higher diuretic doses are associated with an increased risk of mortality in the population analysed.

Structure evalution of electron irradiated borosilicate glass simuluated by molecular dynamics

Sodium borosilicate (NBS) glass is one of the candidate materials for high-level waste glass immobilization. A large number of experiments are performed to study the effect of irradiation by electrons or heavy ions on this type of glass. However, only a few researches of numerically investigating the effect of irradiated NBS glass have been reported. Furthermore those studies mainly focus on heavy-ion irradiation, and none of them is devoted to simulating the effects of electron irradiation on glass that has been irradiated by electrons, especially for structure evolution. In this paper, we propose a novel method of using molecular dynamics (MD) to simulate structure evolution of electron-irradiated NBS glass with compositions of 67.73% SiO2, 18.04% B2O3 and 14.23% Na2O, in mol.%. This method is based on the previous experimental results of Raman spectra and mechanism of structure transformation in irradiated glass. The Raman spectra confirm that the peak indicating the existence of molecular oxygen appears at 1550 cm-1 in irradiated glass. It is assumed that those oxygen atoms do not have any interactions with other adjacent atoms nor participate in the glass network recombination. This assumption is reasonable, for molecular oxygen mainly exists as dissolved oxygen instead of oxygen bubble and is located at interstice of glass network. Thus the presence of molecular oxygen does not have any effect on glass network structure. Then irradiated glass can be obtained by gradually randomly removing a certain number of oxygen atoms from the pristine glass. The glass with removed oxygen atoms is regarded as an irradiated glass which is considered as one irradiated by electrons in experiments. The results derived from MD simulation include average SiOSi bond angle, ring size distribution, sodium profile, evolution of [BO4] units, and [BO3] units. With the increase of removed oxygen atoms, the average bond angle of SiOSi decreases and the number of small rings gradually increases in irradiated glass. Besides, sodium phase separation is observed obviously after extensively removing oxygen. Moreover, in the process of removing oxygen, some [BO4] units transform into [BO3] units, and the transformation process reaches a saturation state finally. Those effects derived from MD such as decrease of SiOSi bond angle, increase of small rings in number, phase separation of sodium and structure change between [BO4] units and [BO3] units, are consistent with those of glass irradiated by electrons in previous experiments. Therefore, the method proposed in this paper will provide a new perspective to understand the mechanism of structure evolution in sodium borosilicate glass after being irradiated by electrons.

A meta-analysis of sodium profiling techniques and the impact on intradialytic hypotension.

Introduction Hemodialysis has improved in recent years, however, despite such improvements, intra-dialytic hypotensive episodes still persist which can lead to a reduction in the overall effectiveness of the treatment. Profiling sodium levels during dialysis can improve vascular refilling andtherefore may prevent hypotensive events. A number of profiling methods exist and this meta-analysis set out to examine the effectiveness of these methods. Methods To assess the effectiveness of hemodialysis sodium profiling techniques. A review and meta-analysis analytical framework was used. A search was conducted using Medline, Embase and CINAHL, Scopus and Web of Knowledge between 1946 and 2014 of published English-language peer reviewed randomized control studies. In total 10 articles were retrieved and included in the review. All data was abstracted with a standardized data collection form. Stata 11.2 (Stata Corp) was used to analyse the data. Actual numbers of hypotensive events were pooled between studies. Analysis of subgroups was performed on sodium profile type. The data were further investigated using meta-regression. Publication bias was also tested. Findings Stepwise profiling was shown to be statistically significantly effective in reducing intradialytic episodes. Results demonstrated that linear sodium profiling was not effective in reducing hypotensive events during dialysis. Discussion This review has shown that using stepwise profiling is more effective at reducing intra-dialytic symptoms than other profiling methods. There was no evidence that linear profiling method was any more effective than conventional dialysis and in fact the results showed the reverse.

Investigation of factors limiting efficiency in Cu(In,Ga)Se2 thin film solar cells during rapid evaporation process

Rapid evaporation is crucial in the low-cost manufacturing of Cu(InxGa1-x)Se2 (CIGS) thin-film solar cells. This form of evaporation deteriorates cell performance in an open-circuit voltage and fill factor. Cell performance is strongly dependent on the deposition process and properties of the thin films. With respect to evaporation rates, analyses of electrical properties, film composition, grain structure, and phase characteristics were conducted to investigate limits on the efficiency of evaporated CIGS thin-film solar cells. CIGS solar cells evaporated at different deposition rates were compared. Raman spectroscopy was used to characterize the residual phases deteriorating the cell performance of these solar cells. Sodium (Na) profiles measured using secondary-ion mass spectrometry revealed that with higher CIGS evaporation rates, Na diffusion in the CIGS layers is lower. Rapidly evaporated CIGS led to two features, residual phases of the CIGS remained and Na concentrations near the surface were insufficient. This result implies that a shortfall in the p-type carrier density during rapid evaporation is a critical factor negatively affecting the efficiency of CIGS thin-film solar cells.

Artificial neural networks for centroiding elongated spots in Shack–Hartmann wavefront sensors

The use of Adaptive Optics in Extremely Large Telescopes brings new challenges, one of which is the treatment of Shack-Hartmann Wavefront sensors images. When using this type of sensors in conjunction with laser guide stars for sampling the pupil of telescopes with 30+ m in diameter, it is necessary to compute the centroid of elongated spots, whose elongation angle and aspect ratio are changing across the telescope pupil. Existing techniques such as Matched Filter have been considered as the best technique to compute the centroid of elongated spots, however they are not good at coping with the effect of a variation in the Sodium profile. In this work we propose a new technique using artificial neural networks, which take advantage of the neural network's ability to cope with changing conditions, outperforming existing techniques in this context. We have developed comprehensive simulations to explore this technique and compare it with existing algorithms.