Characterization Of Membranes Research Articles

A novel poly (lactic-acid) and poly (butylene adipate-co-terephthalate) blend membrane modified with hesperidin for oily water emulsions separation

The oily wastewater produced by a variety of industrial operations presents a serious threat to both humans and the environment. Separation efficiency, good mechanical stability, high flux, and recyclability are critical parameters for a suitable oil-water separation membrane. In this study, a novel blend membrane of (poly (lactic acid)/poly (butylene adipate-co-terephthalate)) with hesperidin-NPs was synthesized by using the phase inversion technique to effectively separate oily-water emulsions. Herein, hesperidin (HSP) was harnessed for the first time as a green agent to optimize its content in the polymeric matrix. (FTIR) Fourier transform infrared spectroscopy, (FESEM) Field emission scanning electron microscopy, (CA) contact angle, mechanical tester, pore size and porosity were utilized to comprehensively characterize the manufactured (PLA/PBAT/HSP) membranes. The current work presents the proposed interaction mechanism between the contents of PLA/PBAT/HSP and the interaction mechanism of PLA/PBAT/HSP membrane with H2O molecules. The synthesized (PLA/PBAT/HSP) membrane manifested high wettability and has a 49° water contact angle and oleophobicity under a water contact angle of 146±2° for diesel oil. The PLA/PBAT membrane exhibited a homogeneous and symmetric spongy-like structure from top to bottom across its entire cross-section with very tiny active layer observed at the top surface of the membrane in FESEM images. Meanwhile, incorporating of 0.0125wt.% HSP into the casting solution has resulted in a significant change in the structural morphology. Furthermore, upon adding the HSP to the polymeric matrix, distinct changes in the structure were formed, which resulted in enhancing the mechanical features (tensile strength) of the membranes. Modified membrane with 0.025wt.% HSP displayed an optimal flux for pure water (220.5L/m2.h1) and the modified membranes maintained a high rejection (more than 99%) against oil-water emulsions. Outcomes demonstrated that the improved permeation and separation characteristics of the (PLA/PBAT/HSP) membranes could present a potential option to treat applications that use oily wastewater.

Analysis and NDT applications of a gas discharge electroacoustic transducer

In this study, a gas discharge electroacoustic transducer (GDEAT) based on a pulsed electric discharge in the air under atmospheric pressure has been investigated. By evaluating acoustic pressure and recording amplitude-frequency characteristics of membranes, the acoustic characteristic of GDEATs have been obtained in the frequency range from 40 Hz to 4 MHz. The electro-thermo-acoustic processes have been studied in gas discharge systems of an open type where the electrode space is in a direct contact with the ambient. Some features of using the above-mentioned GDEATs in nondestructive testing (NDT) of materials have been demonstrated. It has been shown that, on one hand, the wear of both electrodes and insulation limits a work life of a transducer electrode system, but, from the other hand, this may lead to deposition of micro-particles on the surface of an object under test. The wear of electrode systems was evaluated quantitatively, and the results of the chemical analysis of deposited micro-particles have been presented. The use of a GDEATs for non-contact stimulation of local resonant vibrations in subsurface defects and visualizing vibrations by means of laser dopler vibrometry has been shown in the case of NDT of a glass fiber composite.

#470 Relationship between intraperitoneal volume and intraperitoneal pressure during peritoneal dialysis

Abstract Background and Aims Monitoring intraperitoneal pressure (IPP) has been advocated to quantitate intraperitoneal volume (IPV) during peritoneal dialysis (PD). The aim of this study was to investigate the relationship between IPV and IPP during a short PD dwell. Method Thirteen patients (age 60.2 ± 13.8 years, 5 females, BMI 28.6 ± 7.8 kg/m2) were studied during a 2-hour dwell (2 L dialysate, 2.5% dextrose) in a sitting position. IPP was measured 4x per minute by a pressure sensor integrated in the Liberty Cycler (Fresenius Medical Care, Waltham, MA, USA). Segmental abdominal bioimpedance (Hydra 4200, Xitron Technologies, San Diego, CA, USA) was done concurrently to measure IPV. Serum and dialysate creatinine and glucose concentrations were measured before and after the dwell. Dialysate density (ρ) was measured by a handheld density meter (Mettler-Toledo, Columbus, OH USA). Ultrafiltration volume (UFV) was recorded by the Liberty Cycler. A simple physical model (IPP = ρ × h × g) was used to explore the relationship between IPP and IPV (Fig. 1). Based on the model, a change in IPP (ΔIPP) depends on the change of apparent dialysate height (Δh) and dialysate density (Δρ); g is the gravity constant. The apparent cross-sectional area (A) of the peritoneal cavity was calculated as IPV/h. Results Average UFV was 0.31 ± 0.25 L (range 0.03 to 1.03 L). During the dwell, IPP decreased in 12 patients (UFV 0.03 to 0.49 L; Fig. 2) and increased in one (UFV 1.03 L). The IPP decrease (−3.81 ± 2.78 cmH2O; −21.2 ± 18%, p < 0.01) was accompanied by a decrease of apparent h (−0.04 ± 0.03 m; −20.9 ± 18.5%, p < 0.01) and ρ (−3.41 ± 0.56 kg/m3; −0.34 ± 0.06%, p < 0.0001). In patients with a decrease in IPP, the apparent dialysate h decreased from 0.19 ± 0.04 to 0.14 ± 0.04 m, and the apparent A increased from 107.8 ± 23 to 154.7 ± 34 cm2. In the patient with IPP increase, the apparent h increase from 0.14 to 0.18 m, and the apparent A from 138.4 to 164.6 cm2. ΔIPP inversely correlated with Δρ (Fig. 3) and UFV (Fig. 4). Moreover, ΔIPP correlated with D/P creatinine (Fig. 5) and with D/D0 glucose (Fig. 6). Conclusion In this proof-of-concept study, a simple physical model was used to explore the relationship between IPP and IPV. Contrary to our expectation, we found that IPP declines in most patients during the dwell. Decrease in IPP is related to increase in the apparent cross-sectional area of the peritoneal cavity. We hypothesize that during the dwell additional spaces of the peritoneal cavity become accessible to IPV. To what extent this opening of peritoneal space is associated with membrane characteristics warrants further studies.

#3017 Renal-friendly lamivudine dosages are unlikely to contribute to HIV-1 shedding into PD effluents—an open label non-randomized pharmacokinetics study

Abstract Background and Aims Renally adjusted lamivudine dosages are effective. However, some of the kidney failure patients managed with lamivudine-containing regimens are failing to suppress HIV in peritoneal dialysis (CAPD) effluent. The steady-state lamivudine pharmacokinetics among these patients was evaluated. Method This overnight open-label pharmacokinetic study enrolled participants living with HIV and managed with CAPD. Lamivudine levels in blood serum and CAPD effluent samples were quantified using liquid chromatography coupled with a mass spectrometry. Pharmacokinetic measures were obtained through non-compartmental analysis. Results Twenty-eight participants were recruited with a median ARV duration of 8 (IQR, 4.5-10.5) years and a CAPD duration of 13.3 (IQR, 3.3-31.9) months. The majority, 78.6% (22/20) of participants received a 50 mg dose and 25% (1/4) had a detectable HIV viral load (HIV-VL) in CAPD, while 10.7% (3/28), and another 10.7% (3/28) received 75 mg and 300 mg dosages, respectively. Among those treated with 75 and 300 mg, 50% (2/4) and 25% (1/4) had detectable HIV-VL in CAPD, respectively. The peritoneal membrane characteristics and CAPD system strengths were variable across the entire study population. Lamivudine exposure was increased in blood serum (50 mg-AUC0-24 hours, 651.3 ng/mL; 75 mg-AUC0-24 hours, 677.84 ng/mL; 300 mg-AUC0-24 hours, 3135.89 ng/mL) compared to CAPD effluents (50 mg-AUC0-24 hours, 384.91 ng/mL; 75 mg-AUC0-24 hours, 383.24 ng/mL; 300 mg-AUC0-24 hours, 2001.60 ng/mL) among the entire study population. The Cmax (50 mg, 41.5 ng/mL; 75 mg, 53.2 ng/mL; 300 mg, 199.1 ng/mL) and Cmin (50 mg, 17.8 ng/mL; 75 mg, 16.4 ng/mL; 300 mg, 76.4 ng/mL) measured in serum were within the therapeutic levels. Conclusion Steady-state lamivudine pharmacokinetic measures were variable among the entire study population; however, the total lamivudine exposure was within the therapeutic levels.

#3084 Familial nephropathy associated with a combined mutations of Alport and Nail Patella syndrome genes in the same family

Abstract Introduction Alport syndrome is a genetic condition stemming from mutation in Type IV collagen and is characterized by kidney disease and frequently hearing loss and ocular abnormalities. Renal involvement is from an abnormality of the glomerular basement membrane with hematuria and proteinuria progressing eventually to renal failure. In the vast majority, the inheritance is X- linked affecting the alpha 5 chain of type IV collagen while in about 15 percent of the patients the inheritance is autosomal recessive or dominant with mutations affecting alpha 3 or 4 chains of type IV collagen. Sensorineural deafness is common and ocular abnormalities may include lenticonus, corneal opacities, fleck retinopathy and temporal retinal thinning. Nail Patella syndrome (NPS) is a rare genetic condition from mutation in the LMX1B gene on chromosome 9 with an autosomal dominant inheritance. Glomerular disease is from characteristic glomerular basement membrane changes and is associated with nail, pelvic girdle and limb abnormalities. A forme fruste with glomerular lesions but lacking extrarenal features is recognized but uncommon. We present a family with mutations in both COL4A5 and LMX1B presenting with hematuria and proteinuria Case Presentation A 23 year old female was evaluated for hematuria and proteinuria. Her history was notable for kidney biopsy at the age thirteen showing focal and segmental glomerulosclerosis (FSGS). She was treated with tacrolimus for four years from age thirteen through seventeen. Patient was reportedly diagnosed with Nail Patella Syndrome after genetic testing. Her family history was notable for hematuria in her brother and hematuria and proteinuria in her mother. On physical examination she was noted to have no nail or skeletal abnormalities associated with Nail Patella Syndrome. Her labs were notable for a serum creatinine of 0.6 mg/dl and proteinuria of 155 mg/g creatinine of proteinuria. Urine microscopy revealed dysmorphic hematuria. Radiological imaging did not show skeletal abnormalities observed in Nail Patella Syndrome but genetic testing identified a pathogenic variant in COL4A5 c.919G>A (p.Gly307Ser) in addition to a variant of uncertain significance in LMX1B c.349G>A (p.Gly117Ser). Her brother aged 20 had a creatinine of 0.87 mg/dl with dysmorphic hematuria and no proteinuria. Genetic testing showed the same pathogenic variant in COL4A5 as in his sibling. His mother aged 55 was subsequently evaluated and had a creatinine 0.73 mg/dl with dysmorphic hematuria and 152 mg/g of proteinuria. Genetic testing was with the same variant in COL4A5 noted in her two children. Renal biopsy was extensive thinning and segmental lamellation of the glomerular basement membrane with eight percent FSGS. The typical “moth-eaten” appearance of the glomerular basement membrane characteristic of NPS was not evident. Segmental staining was observed with alpha 5 unit of Type IV collagen. Audiology and retinal optical coherence optometry studies are pending. Discussion Alport syndrome and Nail Patella Syndrome are rare genetic disorders that cause variable degrees of renal insufficiency from glomerular base membrane defects and are associated with characteristic extra renal manifestations. This is the first report of an inherited nephritis with combined mutations in COL4A5 and LMX1B. The clinical features and renal biopsy are compatible with Alport Syndrome and the significance of the mutation in LMX1B is uncertain. Conclusion This is the first case report of a combined mutation in COL4A5 and LMX1B gene presenting with hematuria and minimal proteinuria with preserved kidney function.

New Approach to Synthesizing Cathode PtCo/C Catalysts for Low-Temperature Fuel Cells

The presented study is concerned with a new multi-step method to synthesize PtCo/C materials based on composite CoxOy/C that combines the advantages of different liquid-phase synthesis methods. Based on the results of studying the materials at each stage of synthesis with the TG, XRD, TEM, SEI, TXRF, CV and LSV methods, a detailed overview of the sequential changes in catalyst composition and structure at each stage of the synthesis is presented. The PtCo/C catalyst synthesized with the multi-step method is characterized by a uniform distribution of bimetallic nanoparticles of about 3 nm in size over the surface of the support, which result in its high ESA and ORR activity. The activity study for the synthesized PtCo/C catalyst in an MEA showed better current–voltage characteristics and a higher maximum specific power compared with an MEA based on a commercial Pt/C catalyst. Therefore, the results of the presented study demonstrate high prospects for the developed approach to the multi-step synthesis of PtM/C catalysts, which may enhance the characteristics of proton-exchange membrane fuel cells (PEMFCs).

The characteristics of high temperature polymer electrolyte membranes for fuel cell based on 2-pyridene based polybenzimidazole blended with poly(vinyl-phosphonic acid)

The present study has focused on exploring new 2-pyridine-bridge-based polybenzimidazole (2-Py-PBIs) based materials for various energy-related uses in proton exchange membrane fuel cells (PEMFC). An electrochemical device, which transforms chemical energy into electrical energy, is known as fuel cell. Using solution polymerization with polyphosphoric acid as a solvent, a series of 2-Py-PBIs were synthesised from the 4,4'-([2,4′-bipyridine]-2′,6′-diyl)bis (benzene-1,2-diamine). 2-Pyridine bridge Polybenzimidazoles are cross-linked with poly (vinylphosphonic acid), which helps us to improve membrane properties like mechanical properties and proton conductivities. FT-IR was used to characterize chemical structure, Ubbelohde viscometer was employed to determine the inherent viscosity. Additionally investigated were the oxidative stability, swelling ratio, ion exchange capability, and water uptake for 2-Py-PBIs. Thermogravimetric analysis is used to evaluate thermal stability. The obtained 2-Py-PBIs membranes were thermally stable and mechanically strong when compared with conventional polybenzimidazole-based membranes. The 2-Py-PBIs:PVPA membranes showed proton conductivity between 0.10 µS/m to 4.65 µS/m.

Effect and mechanism of solution flow rate during interfacial polymerization on morphology and performance of hollow fiber membranes

Interfacial polymerization (IP) using m-phenylenediamine and trimesoyl chloride (TMC) is an essential method for producing thin-film composite (TFC) membranes. Nevertheless, IP is highly sensitive to changes in process parameters, especially the TMC solutions flow rate during inside-out TFC hollow fibers (HF) production. Research on the impact of flow conditions (i.e., laminar vs. turbulent flows) of these organic solutions on the final membrane characteristics and corresponding mechanism is still lacking. This research tested different TMC flow rates (0.1–2 mL/min) to produce inside-out TFC HF. With a TMC flow rate increase, (i) the leaf-like structures of the polyamide (PA) layer decreased in size, (ii) the thickness of the PA layer slightly increased, and (iii) the pure water permeability decreased. However, the elemental composition, chemical bonds, and NaCl rejection remained stable. Different fluid regimes are considered to affect the performance of HF membranes by affecting the heat dissipation process during IP reaction. A TMC flow rate in the laminar flow state (i.e., low flow rates) is recommended for synthesizing HFs. The current research provides new insights into the IP reaction mechanism of HF membrane, thus offering valuable guidance to optimize and produce membrane products with better performance.

CO2 separation performance and thermo-mechanical characteristics of mixed matrix membranes composed of polyvinylidene fluoride/hyperbranched polyethylenimine embedded with zinc oxide/graphene oxide filler

CO2 separation performance and thermo-mechanical characteristics of mixed matrix membranes composed of polyvinylidene fluoride/hyperbranched polyethylenimine embedded with zinc oxide/graphene oxide filler

Membrane role in heat and mass transfer resistance distribution and performance of hollow fiber membrane contactor for SGMD desalination

Hollow fiber membrane contactor (HFMC) is the core device of heat mass exchange between seawater solution and sweeping air in sweeping gas membrane distillation (SGMD) desalination. In order to reveal the distribution of heat and mass transfer resistance on feed solution side, porous membrane side and sweeping air side, a mathematical model considering the simultaneous heat mass transfer and water vapor diffusion mechanism in the membrane pores was established for the cross-flow HFMC. The simulation results of the model were compared with experimental results and literature results. Comparison shows that the deviation of simulation results of the model is less than 13.4 %, which verifies the accuracy and reliability of the simulation results. Influences of the main structural characteristics of porous membrane on the resistance distribution of heat and mass transfer, efficiency and membrane flux were explored. Air side dominates the heat transfer process, while the membrane side accounts for less than 39 % of the total heat transfer resistance for the main range of membrane microstructure parameters investigated. The mass transfer is controlled by the porous membrane except for thin membrane with a thickness of less than 100 μm. Membranes with porosity above 0.8 and as thin as possible can achieve better mass transfer efficiency and freshwater flux. Increasing mean pore diameter has a strong promotion effect on the increase of membrane flux before it reaches 150 nm, and beyond this critical value, the water vapor diffusion mechanism changes from Knudsen collision to molecular collision. Effects of different operating parameters and membrane microstructure parameters on air temperature distribution and humidity distribution were also analyzed.

Fatty acid composition and biophysical characteristics of the cell membrane of feline spermatozoa

Sperm membrane composition and biophysical characteristics play a pivotal role in many physiological processes (i.e. sperm motility, capacitation, acrosome reaction and fusion with the oocyte) as well as in semen processing (e.g. cryopreservation). The aim of this study was to characterize the fatty acid content and biophysical characteristics (anisotropy, generalized polarization) of the cell membrane of domestic cat spermatozoa. Semen was collected from 34 adult male cats by urethral catheterization. After a basic semen evaluation, the fatty acid content of some of the samples (n = 11) was evaluated by gas chromatography. Samples from other individuals (n = 23) were subjected to biophysical analysis: membrane anisotropy (which is inversely proportional to membrane fluidity) and generalized polarization (describing lipid order); both measured by fluorimetry at three temperature points: 38 °C, 25 °C and 5 °C. Spermatozoa from some samples (n = 10) were cryopreserved in TRIS egg yolk-glycerol extender and underwent the same biophysical analysis after thawing. Most fatty acids in feline spermatozoa were saturated (69.76 ± 24.45%), whereas the polyunsaturated fatty acid (PUFA) content was relatively low (6.12 ± 5.80%). Lowering the temperature caused a significant decrease in membrane fluidity and an increase in generalized polarization in fresh spermatozoa, and these effects were even more pronounced following cryopreservation. Anisotropy at 38 °C in fresh samples showed strong positive correlations with viability and motility parameters after thawing. In summary, feline spermatozoa are characterized by a very low PUFA content and a low ratio of unsaturated:saturated fatty acids, which may contribute to low oxidative stress. Cryopreservation alters the structure of the sperm membrane, increasing the fluidity of the hydrophobic portion of the bilayer and the lipid order in the hydrophilic portion. Because lower membrane fluidity in fresh semen was linked with better viability and motility after cryopreservation, this parameter may be considered an important factor in determination of sperm cryoresistance.

Exploring the effects of flexibility of monomers on poly (isatin monomer-co-biphenyl) anion exchange membranes

To investigate the effect of the monomer with different flexibility and rigidity on the random copolymer, we prepare anion exchange membranes (AEMs) with a similar copolymerization ratio containing different monomers. The results show that the introduction of rigid dibenzofuran, moderately flexible diphenyl ether and flexible bibenzyl affects the conformation and morphology of the polymers, further tuning the overall performance of the AEMs. The three random copolymers exhibit better microphase-separated morphology and conductivity than the homopolymer owing to their more twisted conformation. It is found that the incorporation of flexible monomers has an advantage in holding size consistence and flexibility. Overall, the integration of bibenzyl monomer has the most positive impact on the membrane characteristics, the QPIBBP-40 AEM with flexible units possesses the highest OH− conductivity (80 °C, 159.6 mS cm−1) and an excellent mechanical stability (elongation at break: 48.2 %, tensile strength: 15.6 MPa). The wet-stated QPIBBP-40 AEM maintains an inferior swelling ratio (80 °C, 10.8 %), indicating that it possesses good size consistence and ionic conductivity simultaneously. The highest output power density of the QPIBBP-40 AEM based fuel cell is 655 mW cm−2.

A novel intralamellar semi‐bioresorbable keratoprosthesis—Part A: Design conception, material perspective, and device manufacturing

AbstractCorneal diseases are a significant cause of visual impairment and blindness. The first‐line treatment for corneal opacity is penetrating keratoplasty (human donor cornea transplantation). At present, keratoprosthesis (KPro), an artificial cornea, is the last resort for correcting end‐stage corneal blindness and is usually supported by donor tissue. This article describes a new intralamellar tissue‐free KPro design concept and its preparation method. Wherein, an injection‐molding route is adopted to create a mechanically and structurally stable near‐KPro geometry using a photo‐polymerized poly(2‐hydroxyethyl methacrylate) (pHEMA) with 4% Bisphenol A dimethacrylate (BisMA) crosslinked (PC4) hydrogel composition. Prior to this, the physico‐mechanical properties of crosslinked hydrogels matching corneal tissue are identified, and the surface morphological characteristics of silk cocoon membranes are ascertained in choosing suitable KPro materials. Cytocompatibility tests on PC4 and silk‐incorporated PC4 hydrogels using rabbit corneal fibroblast cell‐line evidenced enhancement in cell growth on silk‐PC4 surfaces. Furthermore, near KPro geometry is surface‐profiled to create a one‐of‐a‐kind design with clear optics and a silk‐bioactivated composite‐based haptic‐flange hydrogel network containing site‐specific submillimeter‐scale perforations to improve tissue integration. Considering this unique KPro geometry, the optic‐haptic‐flange construct is a tissue‐free semi‐bioresorbable hydrogel device presumed to provide stability under the influence of intraocular pressure (IOP) and eyelid shear. Through this study, it is identified new KPro materials facilitate significant cytocompatibility while complimented with site‐specific novel design would offer tissue ingrowth with gradual resorption of silk, leaving behind a stable intralamellar tissue integrated with hydrogel when implanted in the corneal niche.

Adaptive state-of-health temperature sensitivity characteristics for durability improvement of PEM fuel cells

To obtain the temperature sensitivity characteristics of the proton exchange membrane fuel cell under different degradation levels, accelerated durability tests and temperature sensitivity tests of the fuel cell are first performed, and the temperature characteristics under different degradation states are analyzed by electrochemical impedance spectroscopy and polarization curve. Besides, an adaptive state-of-health transient thermal model of fuel cells is developed to investigate the effect of operating temperature on the internal gas concentration and hydrothermal distribution characteristics of the fuel cell from a mechanistic perspective. The experimental results of temperature sensitivity validate that the adaptive state-of-health transient thermal model can effectively monitor the steady and transient performance of the fuel cell. Subsequently, a mathematical model is proposed to describe the relationship among the load current, state of health, and optimal temperature using the temperature sensitivity test data and the transient thermal model of the adaptive state of health, which provides important insights into the optimal temperature range tailored to the current state of health of fuel cells to ensure efficient and stable operation of fuel cells all the time and contributes to the fine design of an optimal degradation adaptive temperature control strategy.

Research on shutdown purge characteristics of proton exchange membrane fuel cells: Purge parameters conspicuity and residual water

This paper comprehensively investigates the purge mechanism of proton exchange membrane fuel cells during the shutdown process, which qualitatively examines the effect of purge parameters (including current density, stoichiometric ratio, and relative humidity) on water content variation, and further quantitatively investigates the remaining water content post-purge. In contrast to previous studies, this paper offers a novel perspective on analyzing the purge process and conducts a thorough examination of residual water content. This study presents a transient, isothermal, two-phase flow model for proton exchange membrane fuel cells, which is subsequently validated experimentally. Results indicate that the significance of purge parameters follows the descending order: stoichiometric ratio, relative humidity, and current density. During the purge, the stoichiometric ratio should be rapidly increased to above 9. Each incremental rise in the stoichiometric ratio from 6 to 14 leads to a respective reduction in residual membrane water content after purge of 2.19 %, 1.57 %, 1.18 %, 0.93 %, 0.76 %, 0.63 %, 0.53 %, and 0.46 %. Similarly, it is recommended to swiftly decrease relative humidity to below 40 %. Elevating the purge current density from 20 to 200 mA/cm2 decreases the time required to completely remove liquid water from 20.24 s to 6.59 s. Hence, employing a higher current density at the onset of the purge facilitates quicker removal of liquid water, albeit resulting in an increase in residual membrane water content post-purge, from 3.17 to 3.70. In summary, optimizing the purge strategy requires adjusting purge current densities according to the specific purge stage.

Assessment of production variables on the performance of ceramic membranes

Water crisis is one of the most important topics nowadays. The water crisis is approaching due to several factors, which is why finding alternative sources of water is important. Water treatment has gained its importance as it decreases the amount of waste water in addition to producing water that can be used in different applications based on its characteristics. Several water treatment techniques are present nowadays; however, research is needed to lower the cost of such techniques in addition to increasing productivity and maximize their range of applicability. Several water treatment techniques are capable of producing fresh water from different types of feed water (saline water, waste water, etc.), these techniques include membrane technologies and thermal technologies. Due to high energy consumption, and lower productivity in thermal techniques membrane techniques are mostly used nowadays in the applications of water treatment. Ceramic membranes have attracted researchers due to their characteristics and wide range of applicability. In this paper, different ceramic membrane types are illustrated; production techniques and the effect of each production variable on the membrane characteristics are shown, in addition to applying a comparison between different additives. Finally, a comparison of performance is carried out.

Improvement of point of care testing device for accurate whole blood glucose measurement in early neonates.

It is important that blood glucose concentrations be accurately and conveniently measured in infants. However, especially in the early neonatal period, point-of-care testing devices used for adults may not accurately measure blood glucose concentrations in neonates. In Study 1, the accuracy of neonatal whole-blood glucose measurements was evaluated for the existing glucose analyser Glutest Mint® (hereinafter MINT1; Sanwa Kagaku Kenkyusho, Nagoya, Japan) by comparing the data with reference blood glucose concentrations. In Study 2, we used MINT2, which was modified based on the findings from Study 1, to measure whole-blood glucose concentrations in newborns, and the accuracy of the measurements was compared with that of MINT1. Blood glucose concentrations were measured in 100 infants each in Study 1 and 2. In Study 1, the whole-blood glucose concentrations measured using MINT1 were found to be significantly lower than the reference blood glucose concentrations in early neonates. The results of Study 1 suggested that characteristics of erythrocyte membranes in early neonates affected the measurements. Therefore, we conducted Study 2 using MINT2, which was modified to be less susceptible. MINT2 was found to accurately measure whole-blood glucose concentrations in the early neonatal period. The study showed that the point-of-care testing device could be improved to allow for accurate whole-blood glucose measurements in the early neonatal period.

Genome-Wide Identification and Analysis of Plasma Membrane H+-ATPases Associated with Waterlogging in Prunus persica (L.) Batsch

Plant plasma membrane H+-ATPase is a transport protein that is generally located on the plasma membrane and generates energy by hydrolyzing adenosine triphosphate (ATP) to pump hydrogen ions (H+) in the cytoplasm out of the cell against a concentration gradient. The plasma membrane H+-ATPases in plants are encoded by a multigene family and potentially play a fundamental role in regulating plant responses to various abiotic stresses, thus contributing to plant adaptation under adverse conditions. To understand the characteristics of the plasma membrane H+-ATPase family in peach (Prunus persica), this study analyzed the plasma membrane H+-ATPase family genes in peach. The results showed that there were 27 members of the plasma membrane H+-ATPase family in peach with amino acid sequences ranging from 943 to 1327. Subcellular localization showed that 23 of the 27 members were located on the cell membrane, and the phylogenetic tree analysis indicated that peach plasma membrane H+-ATPase members were divided into five groups. There were four genes with tandem repeat relationships, and six plasma membrane H+-ATPase genes were differentially expressed after 5 days of flooding and under non-flooding conditions based on the RNA-seq and RT-qPCR analyses. This study also investigated the characteristics and possible functions of the plasma membrane H+-ATPase family members in peach. The results provide theoretical support for further studies on their biological functions in peach.

Pervaporation Membranes Based on Polyelectrolyte Complex of Sodium Alginate/Polyethyleneimine Modified with Graphene Oxide for Ethanol Dehydration.

Pervaporation is considered the most promising technology for dehydration of bioalcohols, attracting increasing attention as a renewable energy source. In this regard, the development of stable and effective membranes is required. In this study, highly efficient membranes for the enhanced pervaporation dehydration of ethanol were developed by modification of sodium alginate (SA) with a polyethylenimine (PEI) forming polyelectrolyte complex (PEC) and graphene oxide (GO). The effect of modifications with GO or/and PEI on the structure, physicochemical, and transport characteristics of dense membranes was studied. The formation of a PEC by ionic cross-linking and its interaction with GO led to changes in membrane structure, confirmed by spectroscopic and microscopic methods. The physicochemical properties of membranes were investigated by a thermogravimetric analysis, a differential scanning calorimetry, and measurements of contact angles. The theoretical consideration using computational methods showed favorable hydrogen bonding interactions between GO, PEI, and water, which caused improved membrane performance. To increase permeability, supported membranes without treatment and cross-linked were developed by the deposition of a thin dense layer from the optimal PEC/GO (2.5%) composite onto a developed porous substrate from polyacrylonitrile. The cross-linked supported membrane demonstrated more than two times increased permeation flux, higher selectivity (above 99.7 wt.% water in the permeate) and stability for separating diluted mixtures compared to the dense pristine SA membrane.

Biochar decorated with metal–organic framework nanoparticles as robust modifier to manipulate nanofiltration mixed matrix membranes characteristics and performance

UiO-66-NH2 metal–organic framework nanoparticles and carbonaceous biochar prepared from the pyrolysis of Cladophora glomerata alga are introduced as novel modifiers and employed to manipulate polyethersulfone (PES) mixed matrix membranes. The membranes were fabricated through immersion precipitation method and fully assessed through X-ray diffraction pattern, field emission scanning electron microscopy, contact angle, atomic force microscopy, and zeta potential analysis. The membrane performances were also examined by water flux, fouling resistance, and solute rejection. The results indicated that the modified membranes manipulated by 0.2–0.8 wt% of modifier had smoother surfaces than the pristine PES membrane. Moreover, by loading the modifiers in the membrane bulk, the zeta potential was changed from negative to positive values. All the modified membranes revealed superior filtration performance compared to that of the pristine PES membrane. In the modified membrane of the best performance, water flux was increased to up to 85% and contact angle was decreased to 43°. Due to the uniform distribution of modifiers on the membrane surface, and thereby, formation of a barrier layer, up to 98.5% of Reactive Blue 50 dye was rejected by the modified membranes. Salt rejections were also improved in the membranes tailored by the introduced modifiers. Furthermore, through the fouling experiments conducted by humic acid and bovine serum albumin, just 12.9 and 34% reductions in water fluxes were recorded for the modified membrane of the best performance. The experimental results indicated that the higher flux recovery ratios could also be expected for all the membranes modified by the novel hydrophilic modifiers.