Estimation of sea water salinity from dielectric measurements: Effect of temperature

439-447Dielectric measurements have been carried out for distilled water and saline water solutions of salinities 10000, 20000, 30000, 40000 ppm, as well as sea water of Diu beach area, using Anritsu Shockline Vector Network Analyzer (VNA, model no: MS46322A) in the frequency range from 1 GHz to 20 GHz, over the temperatures of 20°, 30° and 40 °C. From the measured values of dielectric constant and dielectric loss, the values of tanδ, conductivity and emissivity of water solutions have been calculated. The variation in dielectric properties of water with salinity and temperature of measurement is compared with values calculated using Stogryn equations as well as Klein and Swift model and results are found to be in good agreement with corresponding values. From the dielectric loss values and the emissivity values of distilled water and saline water solutions at certain fixed frequencies, the salinity of sea water collected from Diu beach has been estimated to be 36,327 ppm which agrees very well with the physicochemical analysis report of laboratory

Dielectric properties of soil mixed with urea fertilizer over 20 Hz to 2 MHz frequency range

455-464The dielectric properties of sandy soil for various moisture contents of distilled water and Urea-fluid solutions in soil are estimated in the lower frequency range from 20 Hz to 2 MHz using precision LCR meter. The spectra of complex permittivity e*(ω), loss tangent tan δ(ω), electrical conductivity σ*(ω), and complex impedance Z*(ω) plane plots of these soil-fluid system have been investigated for various moisture contents of different concentrations of Urea solution in the soil samples. The dielectric constant and dielectric loss of the soil increase with increase in moisture content of different concentrations of Urea solution in the soil. The dielectric constant and dielectric loss of the soil increases significantly with the decrease in frequency over the given frequency range. The complex impedance plane (Zʹ versus Zʺ) plot separates electrode polarization and bulk material phenomena, which can also be observed in the dielectric loss tangent peaks

Dielectric properties of soil mixed with urea fertilizer over 20 Hz to 2 MHz frequency range

The dielectric properties of sandy soil for various moisture contents of distilled water and Urea-fluid solutions in soil are estimated in the lower frequency range from 20 Hz to 2 MHz using precision LCR meter. The spectra of complex permittivity e*(ω), loss tangent tan δ(ω), electrical conductivity σ*(ω), and complex impedance Z*(ω) plane plots of these soil-fluid system have been investigated for various moisture contents of different concentrations of Urea solution in the soil samples. The dielectric constant and dielectric loss of the soil increase with increase in moisture content of different concentrations of Urea solution in the soil. The dielectric constant and dielectric loss of the soil increases significantly with the decrease in frequency over the given frequency range. The complex impedance plane (Zʹ versus Zʺ) plot separates electrode polarization and bulk material phenomena, which can also be observed in the dielectric loss tangent peaks

Novel metabolic biomarkers related to sulfur-dependent detoxification pathways in autistic patients of Saudi Arabia

<p>Abstract</p> <p>Background</p> <p>Xenobiotics are neurotoxins that dramatically alter the health of the child. In addition, an inefficient detoxification system leads to oxidative stress, gut dysbiosis, and immune dysfunction. The consensus among physicians who treat autism with a biomedical approach is that those on the spectrum are burdened with oxidative stress and immune problems. In a trial to understand the role of detoxification in the etiology of autism, selected parameters related to sulfur-dependent detoxification mechanisms in plasma of autistic children from Saudi Arabia will be investigated compared to control subjects.</p> <p>Methods</p> <p>20 males autistic children aged 3-15 years and 20 age and gender matching healthy children as control group were included in this study. Levels of reduced glutathione (GSH), total (GSH+GSSG), glutathione status (GSH/GSSG), glutathione reductase (GR), glutathione- s-transferase (GST), thioredoxin (Trx), thioredoxin reductase (TrxR) and peroxidoxins (Prxs I and III) were determined.</p> <p>Results</p> <p>Reduced glutathione, total glutathione, GSH/GSSG and activity levels of GST were significantly lower, GR shows non-significant differences, while, Trx, TrxR and both Prx I and III recorded a remarkably higher values in autistics compared to control subjects.</p> <p>Conclusion</p> <p>The impaired glutathione status together with the elevated Trx and TrxR and the remarkable over expression of both Prx I and Prx III, could be used as diagnostic biomarkers of autism.</p

Mechanism of nitrogen metabolism-related parameters and enzyme activities in the pathophysiology of autism

<p>Abstract</p> <p>Background</p> <p>There is evidence that impaired metabolism play an important role in the etiology of many neuropsychiatric disorders. Although this has not been investigated to date, several recent studies proposed that nitrogen metabolism-related parameters may have a pathophysiological role in autism.</p> <p>Methods</p> <p>The study enrolled 20 Saudi boys with autism aged 4 to 12 years and 20 healthy controls matched for age and gender. Levels of creatine, urea, ammonia, gamma-aminobutyric acid (GABA), glutamate:glutamine (Glu:Gln) ratio, and enzymatic activities of glutamate dehydrogenase, 5'-nucleotidase, and adenosine deaminase (ADA) were determined in plasma samples from both groups.</p> <p>Results</p> <p>We found a significant elevation of creatine, 5'-nucleotidase, GABA, and glutamic acid and a significant decrease in the enzymatic activity of ADA and glutamine level in patients with autism compared with healthy controls. The most significant variation between the two groups was found in the Glu:Gln ratio.</p> <p>Conclusion</p> <p>A raised Glu:Gln ratio together with positive correlations in creatine, GABA, and 5'-nucleotidase levels could contribute to the pathophysiology of autism, and might be useful diagnostic markers. The mechanism through which these parameters might be related to autism is discussed in detail.</p

30-Day morbidity and mortality of bariatric metabolic surgery in adolescence during the COVID-19 pandemic – The GENEVA study

Background: Metabolic and bariatric surgery (MBS) is an effective treatment for adolescents with severe obesity. Objectives: This study examined the safety of MBS in adolescents during the coronavirus disease 2019 (COVID-19) pandemic. Methods: This was a global, multicentre and observational cohort study of MBS performed between May 01, 2020, and October 10,2020, in 68 centres from 24 countries. Data collection included in-hospital and 30-day COVID-19 and surgery-specific morbidity/mortality. Results: One hundred and seventy adolescent patients (mean age: 17.75 ± 1.30 years), mostly females (n = 122, 71.8%), underwent MBS during the study period. The mean pre-operative weight and body mass index were 122.16 ± 15.92 kg and 43.7 ± 7.11 kg/m2, respectively. Although majority of patients had pre-operative testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (n = 146; 85.9%), only 42.4% (n = 72) of the patients were asked to self-isolate pre-operatively. Two patients developed symptomatic SARS-CoV-2 infection post-operatively (1.2%). The overall complication rate was 5.3% (n = 9). There was no mortality in this cohort. Conclusions: MBS in adolescents with obesity is safe during the COVID-19 pandemic when performed within the context of local precautionary procedures (such as pre-operative testing). The 30-day morbidity rates were similar to those reported pre-pandemic. These data will help facilitate the safe re-introduction of MBS services for this group of patients

30-day morbidity and mortality of sleeve gastrectomy, Roux-en-Y gastric bypass and one anastomosis gastric bypass: a propensity score-matched analysis of the GENEVA data

Background: There is a paucity of data comparing 30-day morbidity and mortality of sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), and one anastomosis gastric bypass (OAGB). This study aimed to compare the 30-day safety of SG, RYGB, and OAGB in propensity score-matched cohorts. Materials and methods: This analysis utilised data collected from the GENEVA study which was a multicentre observational cohort study of bariatric and metabolic surgery (BMS) in 185 centres across 42 countries between 01/05/2022 and 31/10/2020 during the Coronavirus Disease-2019 (COVID-19) pandemic. 30-day complications were categorised according to the Clavien–Dindo classification. Patients receiving SG, RYGB, or OAGB were propensity-matched according to baseline characteristics and 30-day complications were compared between groups. Results: In total, 6770 patients (SG 3983; OAGB 702; RYGB 2085) were included in this analysis. Prior to matching, RYGB was associated with highest 30-day complication rate (SG 5.8%; OAGB 7.5%; RYGB 8.0% (p = 0.006)). On multivariate regression modelling, Insulin-dependent type 2 diabetes mellitus and hypercholesterolaemia were associated with increased 30-day complications. Being a non-smoker was associated with reduced complication rates. When compared to SG as a reference category, RYGB, but not OAGB, was associated with an increased rate of 30-day complications. A total of 702 pairs of SG and OAGB were propensity score-matched. The complication rate in the SG group was 7.3% (n = 51) as compared to 7.5% (n = 53) in the OAGB group (p = 0.68). Similarly, 2085 pairs of SG and RYGB were propensity score-matched. The complication rate in the SG group was 6.1% (n = 127) as compared to 7.9% (n = 166) in the RYGB group (p = 0.09). And, 702 pairs of OAGB and RYGB were matched. The complication rate in both groups was the same at 7.5 % (n = 53; p = 0.07). Conclusions: This global study found no significant difference in the 30-day morbidity and mortality of SG, RYGB, and OAGB in propensity score-matched cohorts