Effects of sewage sludge on heavy metal accumulation in soil and plants and on crop productivity in Aleppo governorate

Sewage sludgeHeavy metalsCrop productionCropsOrganic matterSoil

Assessing the protective effect of cutoff walls on groundwater pumping against saltwater upconing in coastal aquifers

Data availability: No data was used for the research described in the article.Copyright © 2022 The Authors. Subsurface physical barriers are amongst the most effective methods to mitigate seawater intrusion in coastal aquifers. The main objective of this study was to examine the impact of cutoff walls on saltwater upconing using laboratory and numerical modelling experiments. Physical experiments were first completed to reproduce the saltwater upconing process in a laboratory-scale coastal aquifer model incorporating an impermeable cutoff wall. Numerical modelling was used for validation purposes and to perform additional simulations to explore the protective effect of cutoff walls against saltwater upconing. The results suggest that the cutoff wall did not substantially delay the saltwater upconing mechanism in the investigated configurations. Laboratory and numerical observations showed the existence of some residual saline water, which remained on the upper part of the aquifer on the seaward side of the wall following the retreat of the saltwater. The protective effect of cutoff walls was noticeably sensitive to the design parameters. Specifically, cutoff walls installed close to the pumping well enabled the implementation of higher pumping rates, therefore a more optimal use of the freshwater, especially for deeper wells. The results highlighted that the penetration depth of the cutoff walls may not necessarily need to exceed the depth of the pumping well to ensure effectiveness, which is of great importance from construction and economic perspectives

Linezolid population pharmacokinetic model in plasma and cerebrospinal fluid among patients with tuberculosis meningitis

BACKGROUND: Linezolid is evaluated in novel treatment regimens for tuberculous meningitis (TBM). Linezolid pharmacokinetics have not been characterized in this population, particularly in cerebrospinal fluid (CSF) where exposures may be affected by changes in protein concentration. Linezolid co-administration with high-dose rifampicin, has also not been studied. We aimed to characterize linezolid plasma and CSF pharmacokinetics in adults with TBM. METHODS: In LASER-TBM pharmacokinetic-substudy, the intervention groups received high-dose rifampicin (35mg/kg) plus linezolid 1200mg/day for 28days, then reduced to 600mg/day. Plasma sampling was done on day 3 (intensive) and on day 28 (sparse). A lumbar CSF sample was obtained on both visits. RESULTS: 30-participants, median(min-max) age and weight of 40(27-56)years and 58(30-96)kg, contributed 247 plasma and 28 CSF observations. Plasma pharmacokinetics was described by one-compartment model with first-order absorption and saturable elimination. Maximal clearance was 7.25L/h, and Km was 27.2mg/L. Rifampicin co-treatment duration did not affect linezolid pharmacokinetics. CSF-Plasma partitioning correlated with CSF total-protein upto 1.2g/L where the partition-coefficient reached maximal value of 37%. Plasma-CSF equilibration half-life was ∼3.5hours. CONCLUSION: Linezolid was readily detected in CSF despite high-dose rifampicin co-administration. These findings support continued clinical evaluation of linezolid plus high-dose rifampicin for the treatment of TBM in adults

Physiological and biochemical analyses shed light on the response of sargassum vulgare to ocean acidification at different time scales

Studies regarding macroalgal responses to ocean acidification (OA) are mostly limited to short-term experiments in controlled conditions, which hamper the possibility to scale up the observations to long-term effects in the natural environment. To gain a broader perspective, we utilized volcanic CO2 vents as a “natural laboratory” to study OA effects on Sargassum vulgare at different time scales. We measured photosynthetic rates, oxidative stress levels, antioxidant contents, antioxidant enzyme activities, and activities of oxidative metabolic enzymes in S. vulgare growing at a natural acidified site (pH 6.7) compared to samples from a site with current pH (pH 8.2), used as a control one. These variables were also tested in plants transplanted from the control to the acidified site and vice-versa. After short-term exposure, photosynthetic rates and energy metabolism were increased in S. vulgare together with oxidative damage. However, in natural populations under long-term conditions photosynthetic rates were similar, the activity of oxidative metabolic enzymes was maintained, and no sign of oxidative damages was observed. The differences in the response of the macroalga indicate that the natural population at the acidified site is adapted to live at the lowered pH. The results suggest that this macroalga can adopt biochemical and physiological strategies to grow in future acidified oceans

A comparison of the population pharmacokinetics of rifampicin, isoniazid and pyrazinamide between hospitalized and non-hospitalized tuberculosis patients with or without HIV

Background. Early mortality among hospitalized HIV-associated tuberculosis (TB/HIV) patients is high despite treatment. The pharmacokinetics of rifampicin, isoniazid, and pyrazinamide were investigated in hospitalized TB/HIV patients and a cohort of outpatients with TB (with or without HIV) to determine whether drug exposures differed between groups. Methods. Standard first-line TB treatment was given daily as per national guidelines, which consisted of oral 4-drug fixed-dose combination tablets containing 150 mg rifampicin, 75 mg isoniazid, 400 mg pyrazinamide, and 275 mg ethambutol. Plasma samples were drawn on the 3rd day of treatment over eight hours post-dose. Rifampicin, isoniazid, and pyrazinamide in plasma were quantified and NONMEM® was used to analyze the data. Results. Data from 60 hospitalized patients (11 of whom died within 12 weeks of starting treatment) and 48 outpatients were available. Median (range) weight and age were 56 (35 - 88) kg, and 37 (19 - 77) years, respectively. Bioavailability and clearance of the three drugs were similar between TB/HIV hospitalized and TB outpatients. However, rifampicin’s absorption was slower in hospitalized patients than in outpatients; mean absorption time was 49.9% and 154% more in hospitalized survivors and hospitalized deaths, respectively, than in outpatients. Higher levels of conjugated bilirubin correlated with lower rifampicin clearance. Isoniazid’s clearance estimates were 25.5 L/h for fast metabolizers and 9.76 L/h for slow metabolizers. Pyrazinamide’s clearance was more variable among hospitalized patients. The variability in clearance among patients was 1.70 and 3.56 times more for hospitalized survivors and hospitalized deaths, respectively, than outpatients. Conclusion. We showed that the pharmacokinetics of first-line TB drugs are not substantially different between hospitalized TB/HIV patients and TB (with or without HIV) outpatients. Hospitalized patients do not seem to be underexposed compared to their outpatient counterparts

IN VITRO EVALUATION OF ENCAPSULATED PROBIOTIC BACTERIA SUPPLEMENTATION TO RUMINANT RATIONS

The aim of this study was to in vitro evaluate encapsulated probiotic supplementation to ruminant rationson degradation and fermentation parameters. The ration consisted of 40% alfalfa hay and 60% concentrate feed mixture. Encapsulated and not encapsulated probiotic were supplemented with level of 106cfu/kg of the total dry matter of ration (DM) and compared with encapsulation media (Sodium Alginate, SA) and control (not supplemented ration). DM and OM degradation and total gas production as well as fermentation parameters of the incubated samples were determined after 24 h of fermentation. Significant (P<0.01) increases in in-vitro DM degradability was observed for the experimental ration supplemented with encapsulated or not encapsulated probiotics at levels (106 CFU/ kg DM) and SA treatment compared to control ration. Also, significant (P<0.05) improvement in OM degradability was recorded for the ration supplemented with not encapsulated probiotics bacteria compared to the other treatments. Moreover no significant differences were observed between the control ration and the rations supplemented with encapsulated probiotics or SA only, as well as no significant difference was recorded between the ration supplemented with encapsulated probiotics and the ration supplemented with SA only. Probiotics bacteria supple mentation in the form of not encapsulated probiotic resulted significant increases in in vitro total gas production per sample and per g DM, OM, dDM, NDF and ADF after 24 hours incubation period compared to the other experimental rations (control, encapsulated probiotic and SA). While significant increase in total gas production per g dOM was observed for not encapsulated probiotic compared to encapsulated probiotic only. It could be concluded that, using encapsulated probiotics bacteria had no significant effect on DM degradability and may be induce decrease in gas production and fermentation parameters

IN-VITRO EVALUATION OF PROBIOTIC BACTERIA SUPPLEMENTATION TO RUMINANT RATIONS

The aim of this study was to evaluate effect of different level of probiotic supplementation to ruminant rations, using in-vitro batch culture technique to determine degradation and fermentation parameters. In vitro experimental ration was formulated, the ration consisted of 40% alfalfa hay and 60% concentrate feed mixture. Three level of probiotic supplementation (106, 108, 1010 cfu/kg DM) were evaluated. DM and total gas production as well as fermentation parameters of the incubated samples were determined after 24 hrs. of fermentation. Slightly increases (P>0.05) in in-vitro dry matter degradability were observed for the ration supplemented with probiotics bacteria at different levels (106,108 and 1010 cfu/ kg DM) compared to control ration. Probiotics bacteria supplementation with different level (106,108 and 1010 cfu/ kg DM) led to significant (P<0.001) increases in organic matter degradability and total gas production per sample and per g DM, OM, NDF and ADF compared to the not supplemented ration (control ration), and no significant differences were observed among the different levels of probiotics supplementation. Significant increase in total volatile fatty acid concentration after 24 hours' incubation period compared to the not supplemented ration. On the other hand, the treatment supplemented with probiotic recorded lower ammonia concentration compared to the control group. It could be concluded that, adding  probiotics bacteria supplementation to experimental ration resulted increase DM and OM degradability and using dose 106 CFU/kg DM feed is sufficient to induce improvement in degradability and fermentation parameter

Liquid Marble Actuator for Microfluidic Logic Systems

© 2018, The Author(s). A mechanical flip-flop actuator has been developed that allows for the facile re-routing and distribution of liquid marbles (LMs) in digital microfluidic devices. Shaped loosely like a triangle, the actuating switch pivots from one bistable position to another, being actuated by the very low mass and momentum of a LM rolling under gravity (~4 × 10 −6 kg ms −1 ). The actuator was laser-cut from cast acrylic, held on a PTFE coated pivot, and used a PTFE washer. Due to the rocking motion of the switch, sequential LMs are distributed along different channels, allowing for sequential LMs to traverse parallel paths. This distributing effect can be easily cascaded, for example to evenly divide sequential LMs down four different paths. This lightweight, cheap and versatile actuator has been demonstrated in the design and construction of a LM-operated mechanical multiplication device — establishing its effectiveness. The actuator can be operated solely by gravity, giving it potential use in point-of-care devices in low resource areas