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Environmental Science and Pollution... Jan 2023Due to disparities in the allocation of rainwater and drought, extreme exploitation of groundwater reservoirs has depleted water supplies in many locations. In addition,... (Comparative Study)
Comparative Study
Due to disparities in the allocation of rainwater and drought, extreme exploitation of groundwater reservoirs has depleted water supplies in many locations. In addition, improper disposal of domestic and industrial waste leads to poor drainage and deterioration of water quality. According to studies, desalination methods are an effective solution for treating unconventional water, i.e., sea and brackish water, and making it usable in daily life. Solar-powered desalination has recently received a great deal of attention around the world. Herein, we summarized challenges and future perspectives associated with solar-powered desalination units. Some hybrid technologies are also discussed like solar-wind desalination and RO-ED crystallizer technology in Morocco and the Middle East and North Africa (MENA) region. Previously, most experimental studies focused on the use of solar energy in traditional desalination methods such as multistage flash and multi-effect distillation. Desalination with reverse osmosis has become popular due to membrane technology improvement and benefits like high recovery ratios and low energy consumption. Furthermore, it has been seen that solar energy is less expensive than the energy obtained from traditional fuels in the MENA area. This article aims to comparatively and systematically review the economic feasibility of the use of solar photovoltaic reverse osmosis in desalination in the MENA region.
Topics: Feasibility Studies; Membranes, Artificial; Osmosis; Solar Energy; Water Purification
PubMed: 36380176
DOI: 10.1007/s11356-022-24116-z -
International Journal of Environmental... Oct 2022There are several techniques for the removal of pharmaceuticals (drugs) from wastewater; however, strengths and weaknesses have been observed in their elimination... (Review)
Review
There are several techniques for the removal of pharmaceuticals (drugs) from wastewater; however, strengths and weaknesses have been observed in their elimination processes that limit their applicability. Therefore, we aimed to evaluate the best techniques for the removal of pharmaceuticals from municipal and hospital wastewater. For this, a non-experimental, descriptive, qualitative-quantitative design was used, corresponding to a systematic review without meta-analysis. Based on established inclusion and exclusion criteria, 31 open-access articles were selected from the Scopus, ProQuest, EBSCOhost, and ScienceDirect databases. The results showed that high concentrations of analgesics such as naproxen (1.37 mg/L) and antibiotics such as norfloxacin (0.561 mg/L) are frequently found in wastewater and that techniques such as reverse osmosis, ozonation, and activated sludge have the best removal efficiency, achieving values of 99%. It was concluded that reverse osmosis is one of the most efficient techniques for eliminating ofloxacin, sulfamethoxazole, carbamazepine, and diclofenac from municipal wastewater, with removal rates ranging from 96 to 99.9%, while for hospital wastewater the activated sludge technique proved to be efficient, eliminating analgesics and antibiotics in the range of 41-99%.
Topics: Wastewater; Sewage; Diclofenac; Naproxen; Norfloxacin; Water Pollutants, Chemical; Carbamazepine; Hospitals; Ozone; Sulfamethoxazole; Anti-Bacterial Agents; Ofloxacin; Pharmaceutical Preparations; Waste Disposal, Fluid
PubMed: 36293682
DOI: 10.3390/ijerph192013105 -
Electrophoresis Jul 2022Accurate manipulation of fluids in microfluidic devices is an important factor affecting their functions. Since the emergence of microfluidic technology to transport... (Review)
Review
Accurate manipulation of fluids in microfluidic devices is an important factor affecting their functions. Since the emergence of microfluidic technology to transport fluids in microchannels, the electric field has been utilized as an effective dynamic pumping mechanism. This review attempts to provide a fundamental insight of the various electric-driven flows in microchannels and their working mechanisms as micropumps for microfluidic devices. Different electrokinetic mechanisms implemented in electrohydrodynamic-, electroosmosis-, electrothermal, and dielectrophoresis-based micropumps are discussed. A detailed description of different mechanisms is presented to provide a comprehensive overview on the key parameters used in electric micropumps. Furthermore, electrode configurations and their shapes in different micropumps are explored and categorized to provide conclusive information for the selection of efficient, simple, and affordable strategies to transport fluids in microfluidic devices. In this paper, recent theoretical, numerical and experimental investigations are covered to provide a better insight both on the operational mechanisms and strategies for lab-on-chip applications.
Topics: Electricity; Electrodes; Electroosmosis; Microfluidic Analytical Techniques; Microfluidics
PubMed: 35452525
DOI: 10.1002/elps.202100317 -
Contraception Feb 2020To understand effect of adjunct misoprostol on cervical preparation with overnight osmotic dilators for dilation and evacuation after 16 weeks gestation. (Meta-Analysis)
Meta-Analysis
OBJECTIVE
To understand effect of adjunct misoprostol on cervical preparation with overnight osmotic dilators for dilation and evacuation after 16 weeks gestation.
METHODS
We searched on-line reference databases using search terms for second trimester, abortion, misoprostol, and dilators. Randomized controlled trials of cervical preparation for second trimester D&E using overnight osmotic dilators comparing adjunct misoprostol to placebo were included. Weighted mean with standard deviation (SD) and pooled binary outcomes were compared.
RESULTS
Among 84 articles identified, three met inclusion criteria (n = 457 subjects) adjunct misoprostol did not significantly decrease mean procedure times (8.5 ± 4.6 vs 9.6 ± 5.8 min, p = 0.78) or manual dilation (18% vs 28%, p = 0.23) when compared to placebo. There was no difference in total complications (p = 0.61), major complications (p = 0.44), or cervical lacerations (p = 0.87).
CONCLUSION
Current limited evidence suggests adjunct misoprostol with osmotic dilators after 16 weeks does not affect procedure time or need for manual dilation.
IMPLICATIONS
Further research is needed to determine the effect of adjunct misoprostol on major complications and blood loss.
Topics: Abortifacient Agents, Nonsteroidal; Abortion, Induced; Dilatation; Extraction, Obstetrical; Female; Humans; Misoprostol; Osmosis; Pregnancy; Pregnancy Trimester, Second
PubMed: 31811840
DOI: 10.1016/j.contraception.2019.09.005 -
The Cochrane Database of Systematic... Feb 2018Every day children and adults die from acute community-acquired bacterial meningitis, particularly in low-income countries, and survivors risk deafness, epilepsy and... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Every day children and adults die from acute community-acquired bacterial meningitis, particularly in low-income countries, and survivors risk deafness, epilepsy and neurological disabilities. Osmotic therapies may attract extra-vascular fluid and reduce cerebral oedema, and thus reduce death and improve neurological outcomes.This is an update of a Cochrane Review first published in 2013.
OBJECTIVES
To evaluate the effects of osmotic therapies added to antibiotics for acute bacterial meningitis in children and adults on mortality, deafness and neurological disability.
SEARCH METHODS
We searched CENTRAL (2017, Issue 1), MEDLINE (1950 to 17 February 2017), Embase (1974 to 17 February 2017), CINAHL (1981 to 17 February 2017), LILACS (1982 to 17 February 2017) and registers of ongoing clinical trials (ClinicalTrials.com, WHO ICTRP) (21 February 2017). We also searched conference abstracts and contacted researchers in the field (up to 12 December 2015).
SELECTION CRITERIA
Randomised controlled trials testing any osmotic therapy in adults or children with acute bacterial meningitis.
DATA COLLECTION AND ANALYSIS
Two review authors independently screened the search results and selected trials for inclusion. Results are presented using risk ratios (RR) and 95% confidence intervals (CI) and grouped according to whether the participants received steroids or not. We used the GRADE approach to assess the certainty of the evidence.
MAIN RESULTS
We included five trials with 1451 participants. Four trials evaluated glycerol against placebo, and one evaluated glycerol against 50% dextrose; in addition three trials evaluated dexamethasone and one trial evaluated acetaminophen (paracetamol) in a factorial design. Stratified analysis shows no effect modification with steroids; we present aggregate effect estimates.Compared to placebo, glycerol probably has little or no effect on death in people with bacterial meningitis (RR 1.08, 95% CI 0.90 to 1.30; 5 studies, 1272 participants; moderate-certainty evidence), but may reduce neurological disability (RR 0.73, 95% CI 0.53 to 1.00; 5 studies, 1270 participants; low-certainty evidence).Glycerol may have little or no effect on seizures during treatment for meningitis (RR 1.08, 95% CI 0.90 to 1.30; 4 studies, 1090 participants; low-certainty evidence).Glycerol may reduce the risk of subsequent deafness (RR 0.64, 95% CI 0.44 to 0.93; 5 studies, 922 participants; low to moderate-certainty evidence).Glycerol probably has little or no effect on gastrointestinal bleeding (RR 0.93, 95% CI 0.39 to 2.19; 3 studies, 607 participants; moderate-certainty evidence). The evidence on nausea, vomiting and diarrhoea is uncertain (RR 1.09, 95% CI 0.81 to 1.47; 2 studies, 851 participants; very low-certainty evidence).
AUTHORS' CONCLUSIONS
Glycerol was the only osmotic therapy evaluated, and data from trials to date have not demonstrated an effect on death. Glycerol may reduce neurological deficiency and deafness.
Topics: Adolescent; Adrenal Cortex Hormones; Adult; Anti-Bacterial Agents; Child; Combined Modality Therapy; Community-Acquired Infections; Deafness; Dexamethasone; Diuretics, Osmotic; Epilepsy; Gastrointestinal Hemorrhage; Glucose; Glycerol; Humans; Intracranial Pressure; Meningitis, Bacterial; Nervous System Diseases; Osmosis; Osmotic Pressure; Randomized Controlled Trials as Topic
PubMed: 29405037
DOI: 10.1002/14651858.CD008806.pub3 -
The Cochrane Database of Systematic... Aug 2016Constipation within childhood is an extremely common problem. Despite the widespread use of osmotic and stimulant laxatives by health professionals to manage... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Constipation within childhood is an extremely common problem. Despite the widespread use of osmotic and stimulant laxatives by health professionals to manage constipation in children, there has been a long standing paucity of high quality evidence to support this practice.
OBJECTIVES
We set out to evaluate the efficacy and safety of osmotic and stimulant laxatives used to treat functional childhood constipation.
SEARCH METHODS
We searched MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, and the Cochrane IBD Group Specialized Trials Register from inception to 10 March 2016. There were no language restrictions. We also searched the references of all included studies, personal contacts and drug companies to identify studies.
SELECTION CRITERIA
Randomised controlled trials (RCTs) which compared osmotic or stimulant laxatives to placebo or another intervention, with participants aged 0 to 18 years old were considered for inclusion. The primary outcome was frequency of defecation. Secondary endpoints included faecal incontinence, disimpaction, need for additional therapies and adverse events.
DATA COLLECTION AND ANALYSIS
Relevant papers were identified and two authors independently assessed the eligibility of trials, extracted data and assessed methodological quality using the Cochrane risk of bias tool. The primary outcome was frequency of defecation. Secondary endpoints included faecal incontinence, disimpaction, need for additional therapies and adverse events. For continuous outcomes we calculated the mean difference (MD) and 95% confidence interval (CI) using a fixed-effect model. For dichotomous outcomes we calculated the risk ratio (RR) and 95% CI using a fixed-effect model. The Chi(2) and I(2) statistics were used to assess statistical heterogeneity. A random-effects model was used in situations of unexplained heterogeneity. We assessed the overall quality of the evidence supporting the primary and secondary outcomes using the GRADE criteria.
MAIN RESULTS
Twenty-five RCTs (2310 participants) were included in the review. Fourteen studies were judged to be at high risk of bias due to lack of blinding, incomplete outcome data and selective reporting. Meta-analysis of two studies (101 patients) comparing polyethylene glycol (PEG) with placebo showed a significantly increased number of stools per week with PEG (MD 2.61 stools per week, 95% CI 1.15 to 4.08). Common adverse events in the placebo-controlled studies included flatulence, abdominal pain, nausea, diarrhoea and headache. Participants receiving high dose PEG (0.7 g/kg) had significantly more stools per week than low dose PEG (0.3 g/kg) participants (1 study, 90 participants, MD 1.30, 95% 0.76 to 1.84). Meta-analysis of 6 studies with 465 participants comparing PEG with lactulose showed a significantly greater number of stools per week with PEG (MD 0.70 , 95% CI 0.10 to 1.31), although follow-up was short. Patients who received PEG were significantly less likely to require additional laxative therapies. Eighteen per cent (27/154) of PEG patients required additional therapies compared to 31% (47/150) of lactulose patients (RR 0.55, 95% CI 0.36 to 0.83). No serious adverse events were reported with either agent. Common adverse events in these studies included diarrhoea, abdominal pain, nausea, vomiting and pruritis ani. Meta-analysis of 3 studies with 211 participants comparing PEG with milk of magnesia showed that the stools per week were significantly greater with PEG (MD 0.69, 95% CI 0.48 to 0.89). However, the magnitude of this difference was quite small and may not be clinically significant. One child was noted to be allergic to PEG, but there were no other serious adverse events reported. One study found a significant difference in stools per week favouring milk of magnesia over lactulose (MD -1.51, 95% CI -2.63 to -0.39, 50 patients), Meta-analysis of 2 studies with 287 patients comparing liquid paraffin (mineral oil) with lactulose revealed a relatively large statistically significant difference in the number of stools per week favouring liquid paraffin (MD 4.94 , 95% CI 4.28 to 5.61). No serious adverse events were reported. Adverse events included abdominal pain, distention and watery stools. No statistically significant differences in the number of stools per week were found between PEG and enemas (1 study, 90 patients, MD 1.00, 95% CI -1.58 to 3.58), dietary fibre mix and lactulose (1 study, 125 patients, P = 0.481), senna and lactulose (1 study, 21 patients, P > 0.05), lactitol and lactulose (1 study, 51 patients, MD -0.80, 95% CI -2.63 to 1.03), hydrolyzed guar gum and lactulose (1 study, 61 patients, MD 1.00, 95% CI -1.80 to 3.80), PEG and flixweed (1 study, 109 patients, MD 0.00, 95% CI -0.33 to 0.33), PEG and dietary fibre (1 study, 83 patients, MD 0.20, 95% CI -0.64 to 1.04), and PEG and liquid paraffin (2 studies, 261 patients, MD 0.35, 95% CI -0.24 to 0.95).
AUTHORS' CONCLUSIONS
The pooled analyses suggest that PEG preparations may be superior to placebo, lactulose and milk of magnesia for childhood constipation. GRADE analyses indicated that the overall quality of the evidence for the primary outcome (number of stools per week) was low or very low due to sparse data, inconsistency (heterogeneity), and high risk of bias in the studies in the pooled analyses. Thus, the results of the pooled analyses should be interpreted with caution because of quality and methodological concerns, as well as clinical heterogeneity, and short follow-up. There is also evidence suggesting the efficacy of liquid paraffin (mineral oil). There is no evidence to demonstrate the superiority of lactulose when compared to the other agents studied, although there is a lack of placebo controlled studies. Further research is needed to investigate the long term use of PEG for childhood constipation, as well as the role of liquid paraffin. The optimal dose of PEG also warrants further investigation.
Topics: Adolescent; Child; Child, Preschool; Constipation; Defecation; Dietary Fiber; Enema; Female; Humans; Infant; Infant, Newborn; Lactulose; Laxatives; Magnesium Hydroxide; Male; Mineral Oil; Osmosis; Polyethylene Glycols; Randomized Controlled Trials as Topic; Senna Extract; Sennosides; Treatment Outcome
PubMed: 27531591
DOI: 10.1002/14651858.CD009118.pub3 -
PloS One 2016In nature, shooting mechanisms are used for a variety of purposes, including prey capture, defense, and reproduction. This review offers insight into the working... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
In nature, shooting mechanisms are used for a variety of purposes, including prey capture, defense, and reproduction. This review offers insight into the working principles of shooting mechanisms in fungi, plants, and animals in the light of the specific functional demands that these mechanisms fulfill.
METHODS
We systematically searched the literature using Scopus and Web of Knowledge to retrieve articles about solid projectiles that either are produced in the body of the organism or belong to the body and undergo a ballistic phase. The shooting mechanisms were categorized based on the energy management prior to and during shooting.
RESULTS
Shooting mechanisms were identified with projectile masses ranging from 1·10-9 mg in spores of the fungal phyla Ascomycota and Zygomycota to approximately 10,300 mg for the ballistic tongue of the toad Bufo alvarius. The energy for shooting is generated through osmosis in fungi, plants, and animals or muscle contraction in animals. Osmosis can be induced by water condensation on the system (in fungi), or water absorption in the system (reaching critical pressures up to 15.4 atmospheres; observed in fungi, plants, and animals), or water evaporation from the system (reaching up to -197 atmospheres; observed in plants and fungi). The generated energy is stored as elastic (potential) energy in cell walls in fungi and plants and in elastic structures in animals, with two exceptions: (1) in the momentum catapult of Basidiomycota the energy is stored in a stalk (hilum) by compression of the spore and droplets and (2) in Sphagnum energy is mainly stored in compressed air. Finally, the stored energy is transformed into kinetic energy of the projectile using a catapult mechanism delivering up to 4,137 J/kg in the osmotic shooting mechanism in cnidarians and 1,269 J/kg in the muscle-powered appendage strike of the mantis shrimp Odontodactylus scyllarus. The launch accelerations range from 6.6g in the frog Rana pipiens to 5,413,000g in cnidarians, the launch velocities from 0.1 m/s in the fungal phylum Basidiomycota to 237 m/s in the mulberry Morus alba, and the launch distances from a few thousands of a millimeter in Basidiomycota to 60 m in the rainforest tree Tetraberlinia moreliana. The mass-specific power outputs range from 0.28 W/kg in the water evaporation mechanism in Basidiomycota to 1.97·109 W/kg in cnidarians using water absorption as energy source.
DISCUSSION AND CONCLUSIONS
The magnitude of accelerations involved in shooting is generally scale-dependent with the smaller the systems, discharging the microscale projectiles, generating the highest accelerations. The mass-specific power output is also scale dependent, with smaller mechanisms being able to release the energy for shooting faster than larger mechanisms, whereas the mass-specific work delivered by the shooting mechanism is mostly independent of the scale of the shooting mechanism. Higher mass-specific work-values are observed in osmosis-powered shooting mechanisms (≤ 4,137 J/kg) when compared to muscle-powered mechanisms (≤ 1,269 J/kg). The achieved launch parameters acceleration, velocity, and distance, as well as the associated delivered power output and work, thus depend on the working principle and scale of the shooting mechanism.
Topics: Animals; Biophysical Phenomena; Energy Metabolism; Fungi; Plant Physiological Phenomena; Predatory Behavior
PubMed: 27454125
DOI: 10.1371/journal.pone.0158277