Turbidity Measurements Research Articles

A low-cost environmentally friendly approach to isolate lignin containing micro and nanofibrillated cellulose from Eucalyptus globulus bark by steam explosion

Micro- and Nano-Fibrillated Cellulose (MNFC) have gained increasing attention due to their remarkable properties, but their production usually requires an intensive multi-step process. This study proposes to find a novel approach involving steam explosion for the production of lignin-containing micro- and nano-fibrillated cellulose (L-MNFC) using Eucalyptus globulus bark as a new lignocellulosic feedstock. Eucalyptus globulus bark was first pre-treated by steam explosion in alkaline conditions (200 °C, 8 min) or by soda cooking in a rotating autoclave (170 °C, 60 min), refined and then ground until gels formed. The chemical composition of the pulps was studied with ion chromatography and FTIR-ATR. The morphology of the products was studied with measurements of suspension turbidity and Morfi Neo, optical and atomic force microscopies. Nanopapers were produced from L-MNFC to investigate mechanical properties. Results obtained showed that steam explosion produced pulps with slightly higher lignin content (≈ 9%), containing shorter fibers (≈ 400 µm) and higher amounts of fines (≈ 86%) compared to soda cooking (≈ 5%, ≈ 560 µm and 66%, respectively). AFM images of SteamEx L-MNFC gels showed a web-like structure containing lignin nanoparticles.Graphical abstract

Enhancement of selective fine particle flotation by microbubbles generated through hydrodynamic cavitation

The flotation of fine particles less than 50 μm is challenging for the mining industry. By using hydrodynamic cavitation, a significant improvement on the recovery of fine particles has been found. This study aims to investigate the effect of hydrodynamic cavitation on the selective flotation of fine particles from detailed mechanism. Our single-bubble flotation results indicated that the bubble-particle collection efficiencies of fine silica particles (D50 = 6 μm and D50 = 16 μm) improved after hydrodynamic cavitation, especially for hydrophobized silica particles. The improved flotation performance of fine particles was investigated from three perspectives: (1) By zeta potential distribution measurements, bubble-frosting on hydrophobic particles was demonstrated after hydrodynamic cavitation. (2) The formation of large aggregates of hydrophobic fine particles after cavitation was revealed by slurry turbidity and particle size measurements, potentially contributing to the improved collision efficiency of the fine particles due to the bridging effect provided by microbubbles. (3) The attachment efficiency between a solid surface and flotation bubbles was enhanced if the surface was covered with hydrodynamic cavitation-generated microbubbles. Compared to the hydrophilic particles, the hydrophobic particles benefited from the hydrodynamic cavitation from the perspectives of bubble frosting, particle-bubble collision efficiency and attachment efficiency. Based on this study, it is expected that the separation efficiency for fine hydrophilic and hydrophobic particles can be improved by hydrodynamic cavitation.

Production of lignin-containing cellulose nanofibrils by the combination of different mechanical processes

Due to its interesting properties, attention has been oriented to the production of cellulose nanofibrils. However, the cellulose isolation requires the combination of several steps which are generally very energy consuming. This is one of the main limitations for the use and industrialization of such materials. Trying to participate in the resolution of this probleme, lignin-containing cellulose nanofibrils are produced for the first time from Posidonia oceanica waste. Fibers are alkali-extracted by a conventional soda cooking in autoclave or by alkaline steam explosion. As conventional refining of unbleached fibers is difficult, a comparative study is carried out to test alternative processes for fiber fibrillation (twin-screw extrusion (1 pass) or steam explosion (during 3 times)). Actually, these two processes are known to be environmentally friendly and low energy consuming. For microfibrillation, an ultra-fine friction grinder is used to prepare lignin-containing cellulose nanofibrils. The obtained gels are characterized by several properties such as morphological analysis (Morfi, optical microscopy, scanning electron microscopy, transmission electron microscopy) and turbidity measurements. Papers and nanopapers are prepared by filtration to investigate the mechanical properties. All these analysis methods allow discussing the efficiency of the different process combinations. It is concluded that steam explosion could be an alternative method for Posidona fiber extraction, while for refining the process conditions should be optimized. Finally, it is found that LCNF produced from extruded pulps (whatever the fiber extraction method) exhibit promising properties comparing with other unbleached CNF.

Near-Infrared Photobiomodulation of Living Cells, Tubulin, and Microtubules In Vitro

We report the results of experimental investigations involving photobiomodulation (PBM) of living cells, tubulin, and microtubules in buffer solutions exposed to near-infrared (NIR) light emitted from an 810 nm LED with a power density of 25 mW/cm2 pulsed at a frequency of 10 Hz. In the first group of experiments, we measured changes in the alternating current (AC) ionic conductivity in the 50–100 kHz range of HeLa and U251 cancer cell lines as living cells exposed to PBM for 60 min, and an increased resistance compared to the control cells was observed. In the second group of experiments, we investigated the stability and polymerization of microtubules under exposure to PBM. The protein buffer solution used was a mixture of Britton-Robinson buffer (BRB aka PEM) and microtubule cushion buffer. Exposure of Taxol-stabilized microtubules (~2 μM tubulin) to the LED for 120 min resulted in gradual disassembly of microtubules observed in fluorescence microscopy images. These results were compared to controls where microtubules remained stable. In the third group of experiments, we performed turbidity measurements throughout the tubulin polymerization process to quantify the rate and amount of polymerization for PBM-exposed tubulin vs. unexposed tubulin samples, using tubulin resuspended to final concentrations of ~ 22.7 μM and ~ 45.5 μM in the same buffer solution as before. Compared to the unexposed control samples, absorbance measurement results demonstrated a slower rate and reduced overall amount of polymerization in the less concentrated tubulin samples exposed to PBM for 30 min with the parameters mentioned above. Paradoxically, the opposite effect was observed in the 45.5 μM tubulin samples, demonstrating a remarkable increase in the polymerization rates and total polymer mass achieved after exposure to PBM. These results on the effects of PBM on living cells, tubulin, and microtubules are novel, further validating the modulating effects of PBM and contributing to designing more effective PBM parameters. Finally, potential consequences for the use of PBM in the context of neurodegenerative diseases are discussed.

SDS‐induced amyloid fibrillation of acidic fibroblast growth factor

Fibroblast growth factors and their receptors regulate a broad range of biological functions from developmental processes during embryogenesis to various physiological roles in the adult state, including regulation of angiogenesis, wound healing, and metabolism. hFGF‐1 also plays a key role in neuroprotection against neurotoxicity in Alzheimer’s disease (AD). The anionic surfactant sodium dodecyl sulfate (SDS) is widely used as a model for induction of amyloid‐like fibrils. In this context, we examined the effects of SDS on FGF1 using a variety of biophysical techniques including, Transmission Electron Microscopy (TEM). The secondary structure of hFGF1 was monitored by incubating hFGF1 with different concentrations of SDS utilizing the far‐UV CD (190‐250 nm) spectroscopy. We found that from 0.08‐0.15mM concentration of SDS, the negative peak at ~206 shifted gradually towards ~212nm while at 0.2mM concentration, far‐UV CD spectra of hFGF‐1 exhibit significant changes with striking shifting of negative peak ~212 nm to ~218 nm and disappearance of positive band at ~228nm which signifies substantial loss of native β‐barrel structure. The aggregation of hFGF‐1 is detected systematically by observing the absorbance at 350nm. The results indicate that at 0.2mM SDS, hFGF1 highly aggregates. In addition to far‐UV CD spectra and turbidity measurement, the influence of SDS on the tertiary structural changes of hFGF1 was studied by mentoring the intrinsic fluorescence of hFGF1 incubated with various concentrations of SDS. The study reveals that 0.2mM SDS is the concentration that affect mostly on the tertiary structure of hFGF1 because of the highest ratio of 305 to 350 at this concentration. Thioflavin‐T (ThT) assay for quantification of Amyloid‐like fibril formation was used to investigate the concentration of SDS that induce maximum hfGF1 fibrils. This study showed that 0.2mM SDS is the concentration that induced the optimum formation of fibrils hFGF1. Based on the results of these experiments, we wanted to do more investigation to achieve more evidence about the effect of SDS on the fibrils hFGF1. Therefore, morphological study by TEM was employed to examine the effect of 0.2mM SDS and 0.6mM SDS on the formation of fibrils hFGF1. At incubation for 1‐hour fibrillar aggregates of hFGF‐1 with average diameter at about 20‐25nm is observed in presence of 0.2mM SDS. All the previous results using biophysical techniques indicate that SDS induces formation of fibrils hFGF1 concentration which assist to better understanding about the causative of the fibrils hFGF1 which lead to find a remedy for the disease related with it.

Evaluating the Effects of Chondroitin Sulfate and Hyaluronic Acid in Modifying the Properties of Collagen‐Based Matrices

The extracellular matrix (ECM) enveloping cells in living tissue is comprised of signaling and structural support molecules. The ECM is vital to maintenance of normal tissue as it controls cell signaling and is a semiporous barrier to interstitial fluid flow. Two important types of ECM molecules are fibrillar collagen (e.g. type I) and glycosaminoglycans (GAGs). In certain solid tumors, hyaluronic acid (HA) and chondroitin sulfate (CS) are two types of GAG molecules that are known to be unusually abundant. These GAGs are negatively charged with the propensity to imbibe aqueous fluid and promote tissue swelling. While many studies have described the effect each molecule has on shaping ECM properties, studies describing how the CS and HA interact with each other are much less common. This study uses an integrated approach to characterize the effects of HA and CS on fluid transport (hydraulic permeability), stiffness (indentation modulus), collagen polymerization kinetics (turbidity), and matrix microarchitecture (pore size and fiber radius). Utilizing a microfluidic approach to study hydraulic permeability observed that the addition of GAGs decreased convective fluid transport. Indenting the hydrogels with a macroscale indenter demonstrated no changes in stiffness when adding CS, while HA, and CS/HA increased hydrogel stiffness. Analysis of confocal reflectance microscopy images showed increases in both pore size and fiber radius with the addition of both GAG molecules. Finally, turbidity measurements concluded that adding GAGs to a collagen gel accelerated its polymerization, with the change in fiber radius being the primary determinant in enhanced fibril formation. This study provides additional evidence that GAGs play an important role in defining physical properties of the ECM and demonstrates further ways into controllably modifying collagen based hydrogels via the addition of native ECM molecules.

Thermosensitive core-rigid micelles of monomethoxy poly(ethylene glycol)-deoxy cholic acid

BackgroundThermosensitive micelles with rigid cores that exhibit a reversible lower critical solution temperature at 30–35 °C can be applied for drug delivery.MethodHydrophilic monomethoxy poly(ethylene glycol) was conjugated to hydrophobic deoxycholic acid to prepare monomethoxy poly(ethylene glycol)-deoxycholic acid (mPEG-DC). Micelle formation and thermosensitive solution behavior were studied using various methods, including hydrophobic dye solubilization, transmission electron microscopy, dynamic light scattering, turbidity measurement, microcalorimetry, and 1H-NMR spectroscopy. Drug release from the thermosensitive micelles was demonstrated using estradiol, a model drug.ResultsThe mPEG-DC formed micelles with a critical micelle concentration of 0.05 wt.% and an average size of 15 nm. Aqueous mPEG-DC solutions exhibit a lower critical solution temperature (LCST) that is independent of concentration and reversible over heating and cooling cycles. The LCST transition is an entropically driven process involving dehydration of the PEG shell. The thermosensitive mPEG-DC micelles with rigid DC cores were applied as an estradiol delivery system in which estradiol was released, without initial burst, over the 16 days in a diffusion-controlled manner.ConclusionsThis study suggests that mPEG-DCs form thermosensitive micelles with rigid cores that can function as an excellent diffusion-controlled hydrophobic drug delivery system without initial burst release.Graphical Thermosensitive core-rigid micelles of monomethoxy poly(ethylene glycol)-deoxy cholic acid

Turbidity Characteristics of The Waters on The Padelegan Beach, Pademawu District, Pamekasan Regency, East Java

Padelegan Beach is one of the beaches used for tourism and seaweed cultivation activities, which is located in Pademawu District, Pamekasan Regency. The distribution of water turbidity plays an important role in the success of seaweed cultivation activities and salt ponds along the Jumiang coast. The purpose of this research is to know the condition of turbidities distribution in Jumiang waters. The sampling method used the purposive sampling method with the location of nine sampling stations. The location of the turbidity measurement is based on thereare near the coast (points 1, 2, 3), beaches (points 4, 5, 6), and the high seas (7, 8, 9). Turbidity was measured using the Lutron TU-2016 Turbidity Meter. The results show that the turbidity distribution at station points near the coast is higher in value than at high sea station points. The highest turbidity value is 29,82 NTU in the coastal area, while the lowest is 4,35 NTU the offshore. The turbidity value in Jumiang coastal waters shows a value below the threshold for turbidity that is intended for cultivation activities.Keywords: characteristics, turbidity, The Padelegan Beach

Sistem Kendali Dan Monitoring Tingkat Kekeruhan Air Pada Air PDAM Menggunakan Arduino Uno

Based on the survey that has been carried out, the PDAM operator detects turbidity in the water treatment plant using the conventional method (visual) and records the value of changes in turbidity that occur manually. This device is controlled by an Arduino uno microcontroller IC as a command process to be executed and a turbidity sensor that will detect turbidity in water and smartphones as monitoring media and turbidity sensor data application media. After various tests and analyzes have been carried out on the control design and monitoring of PDAM water turbidity, the measurement of this system uses the Turbidity sensor module so that it can facilitate the measurement of PDAM water turbidity and water control so that the water is not cloudy with a tool control system carried out by internet communication using the IOT method. (Internet of Things) and also the water pump motor uses a 220v AC type poma motor and uses a water filter to purify the water.

Co-administration of drugs with parenteral nutrition in the neonatal intensive care unit—physical compatibility between three components

There is a lack of compatibility data for intravenous therapy to neonatal intensive care unit (NICU) patients, and the purpose of this study was to contribute with documented physical compatibility data to ensure safe co-administration. We selected Numeta G13E, the 3-in-1 parenteral nutrition (PN) used at our NICU, together with the frequently used drugs morphine, dopamine and cefotaxime in two- but also three-component combinations. Incompatibility may lead to particle formation (precipitation) and oil-droplet growth (emulsion destabilisation), both which are undesirable and pose a safety risk to already unstable patients. We assessed potential particle formation of three mixing ratios for each combination (always including 1 + 1 ratio) using light obscuration, turbidity and pH measurements combined with visual inspection by focused Tyndall beam. Potential droplet-growth and emulsion destabilisation was assessed by estimating PFAT5 from droplet size measurements and counts, mean droplet diameter and polydispersity index from dynamic light scattering, and pH measurements. Mixed samples were always compared to unmixed controls to capture changes as a result of mixing and samples were analysed directly after mixing and after 4 h to simulate long contact time. None of the samples showed any sign of precipitation, neither in the drug-drug nor in the two- or three-component mixture with PN. Neither did we detect any form of emulsion destabilisation.Conclusion: Dopamine, morphine and cefotaxime were found to be compatible with NumetaG13E, and it is safe to co-administer these drugs together with this PN in NICU patients.What is Known:• The need for co-administration of drugs and complex PN admixtures occurs frequently in NICU due to limited venous access.• Available compatibility data are scarce and for combinations of more than two components non-existent.What is New:• Here we report physical compatibility data of two- as well as three-component combinations of frequently used NICU drugs and a 3-in-1 PN admixture.• Co-administration of Numeta G13E with dopamine and morphine, but also with morphine and cefotaxime is safe in NICU.

Chlorophyll-a Pigment Measurement of Spirulina in Algal Growth Monitoring Using Portable Pulsed LED Fluorescence Lidar System.

Chlorophyll-a measurement is important in algal growth and water quality monitoring in natural waters. A portable pulsed LED fluorescence lidar system based on the preliminary algal organic matter and pigments excitation–emission matrix (EEM) of commercialized AZTEC Spirulina powder at varying concentrations was developed. Fluorescence peaks from EEMs showed increasing intensity as the Spirulina concentration increases. Using this information, an LED fluorescence lidar with a wavelength of 385 nm, pulse width of 10 ns, and repetition frequency of 500 kHz was constructed for chlorophyll detection at 680 nm. Turbidity measurements were also conducted at 700 nm emission wavelength at the same excitation wavelength. Range-resolved fluorescence lidar signals from the portable pulsed LED fluorescence lidar system are highly correlated with the standard methods such as optical density at 680 nm (R2 = 0.87), EEM fluorescence chlorophyll-a pigment at 680 nm (R2 = 0.89), and corrected chlorophyll-a concentration (R2 =0.92). The F680/F700 lidar ratio was measured to provide a linear relationship of chlorophyll-a and turbidity in waters. The F680/F700 measurement showed strong correlations with Spirulina concentration (R2 = 0.94), absorbance at 680 nm (R2 = 0.84), EEM chlorophyll-a pigment at 680 nm (R2 = 0.83), and corrected chlorophyll-a concentration (R2 = 0.86). Results revealed that this new technique of chlorophyll-a measurement can be used as an alternative to other standard methods in algal growth monitoring.

Connections among Land Use, Water Quality, Biodiversity of Aquatic Invertebrates, and Fish Behavior in Amazon Rivers.

Rivers in the Amazon have among the greatest biodiversity in the world. The Xingu River, one of the tributaries of the Amazon River, has a length of 1640 km, draining 510,000 km2 in one of the most protected regions on the planet. The Middle Xingu region in Brazil has been highly impacted by mining and livestock farming, leading to habitat fragmentation due to altered water quality. Therefore, comparing two rivers (the preserved Xingu River and the impacted Fresco River) and their confluence, the aims of the present study were to (1) assess the land uses in the hydrographic basin; (2) determine the water quality by measurements of turbidity, total solids, and metals (Cd, Cu, Fe, Mn, Pb, Zn, and Hg); (3) compare the zooplankton biodiversity; and (4) to evaluate the avoidance behavior of fish (Astyanax bimaculatus) when exposed to waters from the Xingu and Fresco Rivers. Zooplankton were grouped and counted down to the family level. For the analysis of fish avoidance, a multi-compartment system was used. The forest class predominated at the study locations, accounting for 57.6%, 60.8%, and 63.9% of the total area at P1XR, P2FR, and P3XFR, respectively, although since 1985, at the same points, the forest had been reduced by 31.3%, 25.7%, and 27.9%. The Xingu River presented almost 300% more invertebrate families than the Fresco River, and the fish population preferred its waters (>50%). The inputs from the Fresco River impacted the water quality of the Xingu River, leading to reductions in local invertebrate biodiversity and potential habitats for fish in a typical case of habitat fragmentation due to anthropic factors.

Sediment dynamics on the outer-shelf of the Gulf of Lions during a storm: An approach based on acoustic glider and numerical modeling

Describing and quantifying storm-induced sediment dynamics enables improved mapping of the fate of sediments over continental shelves, which is necessary to understand their role in the structure and dynamics of marine ecosystems, nutrient cycling, and dispersion of pollutants. Storms are episodic processes that can lead to massive sediment resuspension and transport on continental shelves. However, understanding sediment dynamics during storms remains a challenge, because these events are spatially under-sampled due to their intermittency and intensity. This paper quantifies processes that drive sediment dynamics and their spatiotemporal variability over the outer shelf of the Gulf of Lions (NW Mediterranean), during a 5-year return period storm, using an active acoustic glider combined with a hydrodynamic model (SYMPHONIE) and wave model (WAVEWATCH-III). The glider-ADCP (Acoustic Doppler Current Profiler) measurements proved invaluable validation of current vertical profiles of the hydrodynamic model during this episodic event. The combination of observations with numerical simulations suggest that sediment resuspension is an important process at depths greater than 90 m on the shelf. This appears to be primarily due to the wave forcing, which most likely accounts for some of the observed increase in suspended particulate matter in the water column. At the regional scale, an along shelf sediment transfer by successive jumps associated with onshore storms is suggested, from the main input (the Rhone River) to the output (the Cap de Creus) area of the Gulf of Lions’ shelf. This study highlights the complementarity between numerical modeling and new observation instrument designed to spatially extend the measurement of current and turbidity to study sediment resuspension and transport during extreme events on continental shelves.

Reduced fibrin clot lysis in Klinefelter syndrome associated with hypogonadism.

Objective Klinefelter syndrome (KS) is associated with increased risk of thrombosis. Hypogonadism and accumulating body fat in KS have a potential impact on fibrinolysis. In this study, we assessed the fibrinolytic system and the association with testosterone levels in KS.Design This study is a cross-sectional comparison of men with KS and age-matched male controls.Methods Fibrin clot lysis was evaluated by turbidity measurements and by measuring levels of individual fibrinolytic proteins in plasma samples. Fibrin clot structure was evaluated by scanning electron microscopy. Total testosterone was measured by liquid chromatography-tandem mass spectrometry. Body fat was evaluated by dual-energy X-ray absorptiometry.Results In this study, 45 men with KS and 45 age- and education-matched controls were included. Men with KS had a 24% reduction in fibrin clot lysis compared with controls (46.2 ± 17.1 vs 60.6 ± 18.8 %/h, P = 0.0003) and higher levels of fibrinogen, factor XIII (P ≤ 0.01), and plasminogen activator inhibitor type 1 (P = 0.04). Men with KS had lower total testosterone (P = 0.008) and higher body fat (P = 0.001). In KS, reduced fibrin clot lysability was associated with higher fibrinogen and body fat related to decreasing total testosterone and hypogonadism among men with KS. Fibrin clot structure was not different compared to KS and controls.Conclusions Fibrin clot lysis in KS was markedly reduced, potentially contributing to a prothrombotic state and increasing thrombotic risk. Hypogonadism in KS was associated with increased fibrinogen and total body fat, predicting reduced fibrin clot lysis.

Effect of High Hydrostatic Pressure Intensity on Structural Modifications in Mealworm (Tenebrio molitor) Proteins

Processing edible insects into protein extracts may improve consumer acceptability. However, a better understanding of the effects of food processing on the proteins is needed to facilitate their incorporation into food matrices. In this study, soluble proteins from Tenebrio molitor (10% w/v) were pressurized using high hydrostatic pressure (HHP) at 70–600 MPa for 5 min and compared to a non-pressurized control (0.1 MPa). Protein structural modifications were evaluated using turbidity measurement, particle-size distribution, intrinsic fluorescence, surface hydrophobicity, gel electrophoresis coupled with mass spectrometry, and transmission electron microscopy (TEM). The observed decrease in fluorescence intensity, shift in the maximum emission wavelength, and increase in surface hydrophobicity reflected the unfolding of mealworm proteins. The formation of large protein aggregates consisting mainly of hexamerin 2 and ⍺-amylase were confirmed by protein profiles on gel electrophoresis, dynamic light scattering, and TEM analysis. The typical aggregate shape and network observed by TEM after pressurization indicated the potential involvement of myosin and actin in aggregate formation, and these were detected by mass spectrometry. For the first time, the identification of mealworm proteins involved in protein aggregation phenomena under HHP was documented. This work is the first step in understanding the mealworm protein–protein interactions necessary for the development of innovative insect-based ingredients in food formulations.

Pilot Testing of the "Turbidimeter", a Simple, Universal Reader Intended to Complement and Enhance Bacterial Growth Detection in Manual Blood Culture Systems in Low-Resource Settings.

Bloodstream infections and antimicrobial resistance are an increasing problem in low-income countries. There is a clear need for adapted diagnostic tools. To address this need, we developed a simple, universal reader prototype that detects bacterial growth in blood culture bottles. Our “turbidimeter” evaluates bacterial growth, based on the turbidity of the broth and the color change of the colorimetric CO2 indicator in commercially available blood culture bottles. A total of 60 measurements were performed using 10 relevant microbial species, spiked in horse blood, to compare the turbidimeter’s performance with that of an automatic reference system. The turbidimeter was able to detect growth in all but one of the spiked blood culture bottles. In the majority (7/10) of the species tested, time-to-detection of the turbidimeter was shown to be non-inferior to the reference automated time-to-detection. This was, however, only the case when both the turbidity and color change in the colorimetric CO2-indicator were used to evaluate growth. We could not demonstrate the non-inferiority of the turbidity measurement alone. Overall, the turbidimeter performed well, but we also identified some improvements that will be implemented in the next version of the prototype.

LED PEDD Discharge Photometry: Effects of Software Driven Measurements for Sensing Applications.

This work explores the effects of embedded software-driven measurements on a sensory target when using a LED as a photodetector. Water turbidity is used as the sensory target in this study to explore these effects using a practical and important water quality parameter. Impacts on turbidity measurements are examined by adopting the Paired Emitter Detector Diode (PEDD) capacitive discharge technique and comparing common embedded software/firmware implementations. The findings show that the chosen software method can (a) affect the detection performance by up to 67%, (b) result in a variable sampling frequency/period, and (c) lead to an disagreement of the photo capacitance by up to 23%. Optimized code is offered to correct for these issues and its effectiveness is shown through comparative analyses, with the disagreement reduced significantly from 23% to 0.18%. Overall, this work demonstrates that the embedded software is a key and critical factor for PEDD capacitive discharge measurements and must be considered carefully for future measurements in sensor related studies.

Metal ion scavenging activity of elastin-like peptide analogues containing a cadmium ion binding sequence

The development of simple and safe methods for recovering environmental pollutants, such as heavy metals, is needed for sustainable environmental management. Short elastin-like peptide (ELP) analogues conjugated with metal chelating agents are considered to be useful as metal sequestering agents as they are readily produced, environment friendly, and the metal binding domain can be selected based on any target metal of interest. Due to the temperature dependent self-assembly of ELP, the peptide-based sequestering agents can be transformed from the solution state into the particles that chelate metal ions, which can then be collected as precipitates. In this study, we developed a peptide-based sequestering agent, AADAAC-(FPGVG)4, by introducing the metal-binding sequence AADAAC on the N-terminus of a short ELP, (FPGVG)4. In turbidity measurements, AADAAC-(FPGVG)4 revealed strong self-assembling ability in the presence of metal ions such as Cd2+ and Zn2+. The results from colorimetric analysis indicated that AADAAC-(FPGVG)4 could capture Cd2+ and Zn2+. Furthermore, AADAAC-(FPGVG)4 that bound to metal ions could be readily recycled by treatment with acidic solution without compromising its metal binding affinity. The present study indicates that the fusion of the metal-binding sequence and ELP is a useful and powerful strategy to develop cost-effective heavy metal scavenging agents with low environmental impacts.

Delayed alveolar clearance of nanoparticles through control of coating composition and interaction with lung surfactant protein A

The coating composition of nanomedicines is one of the main features in determining the medicines' fate, clearance, and immunoresponse in the body. To highlight the coatings' impact in pulmonary administration, two micellar superparamagnetic iron oxide nanoparticles (SPION) were compared. These nanoparticles are similar in size and charge but have different coatings: either phosphatidylcholine (PC-SPION) or bovine serum albumin (BSA-SPION). The aim of the study was to increase the understanding of the nano-bio interaction with the cellular and non-cellular components of the lung and underline valuable coatings either for local lung-targeted drug delivery in theranostic application or patient-friendly route systemic administration. PC-SPION and BSA-SPION were deposited in the alveoli by in vivo instillation and, despite the complexity of imaging the lung, SPION were macroscopically visualized by MRI. Impressively, PC-SPION were retained within the lungs for at least a week, while BSA-SPION were cleared more rapidly. The different lung residence times were confirmed by histological analysis and supported by a flow cytometry analysis of the SPION interactions with different myeloid cell populations. To further comprehend the way in which these nanoformulations interact with lung components at the molecular level, we used fluorescence spectroscopy, turbidity measurements, and dynamic light scattering to evaluate the interactions of the two SPION with surfactant protein A (SP-A), a key protein in setting up the nanoparticle behavior in the alveolar fluid. We found that SP-A induced aggregation of PC-SPION, but not BSA-SPION, which likely caused PC-SPION retention in the lung without inducing inflammation. In conclusion, the two SPION show different outcomes from interaction with SP-A leading to distinctive fate in the lung. PC-SPION hold great promise as imaging and theranostic agents when prolonged pulmonary drug delivery is required.

Flow Injection Analysis with Turbidity Detection for the Quantitative Determination of Mebeverine Hydrochloride in Pharmaceutical Formulations

The main objective of this paper is to develop and validate flow injection method, a precise, accurate, simple, economic, low cost and specific turbidimetric method for the quantitative determination of mebeverine hydrochloride (MbH) in pharmaceutical preparations. A homemade NAG Dual & Solo (0-180º) analyser which contains two identical detections units (cell 1 and 2) was applied for turbidity measurements. The developed method was optimized for different chemical and physical parameters such as perception reagent concentrations, aqueous salts solutions, flow rate, the intensity of the sources light, sample volume, mixing coil and purge time. The correlation coefficients (r) of the developed method were 0.9980 and 0.9986 for cell 1 and 2 respectively and showed the linearity of response against concentration over the range of 1.0 to 6.5 and 0.7-6.5mmol/L for cell 1 & 2 respectively. The limit of detections (LOD) for cell 1 and cell 2 were 0.28 and 0.21 mmol/L respectively. The intra-day and inter-day precision for two serial estimations of 3.5 and 5.5 mmol/L of MBH exhibited a relative standard deviation of 0.46%, 0.28%, 0.23%, 0.26% and 0.39%, 0.79%, 0.14%, 0.05% for cell 1 & 2 respectively. The accuracy of the developed method has expressed a recovery percentage (Rec %) and error % which was between 99.22 to 101.13 and 99.39 to 101.17 for cell 1 and cell 2 respectively. The ICH guidelines were followed for method validation. The developed method was successfully applied for the determination of MbH in pure and pharmaceutical preparations and the method can be conveniently used for routine analysis in laboratory as a quality control method since the method permits quantitively determination of 60 samples/h.