Optimal Concentration Research Articles

A Gold Nanoparticle-Based Cortisol Aptasensor for Non-Invasive Detection of Fish Stress

Cortisol is a key stress biomarker in humans and animals, including fishes. In aquafarming, stress monitoring using cortisol quantification can help to optimize aquaculture practices for welfare and productivity enhancement. However, most current methods for cortisol detection rely on invasive tissue sampling. In this work, we developed a gold nanoparticle (AuNP)-based cortisol sensor to address the demand of detecting picomolar ranges of cortisol from complex fish tank water matrices as a non-invasive alternative for more effective stress monitoring. We first identified a DNA aptamer with effective binding to cortisol and then conjugated the thiol-labelled aptamer to AuNPs together with a blocker molecule (CALNN) to form an Au-Apt-CALNN conjugate that is stable in fish tank water. The cortisol detection principle is based on magnesium chloride (MgCl2)-induced particle aggregation, where the cortisol-bound aptamer on the AuNPs folds into a tertiary structure and provides greater protection for Au-Apt-CALNN against MgCl2-induced aggregation due to steric stabilization. At an optimum MgCl2 concentration, the differential stability of particles with and without cortisol binding offers a limit of detection (LOD) of 100 pM for cortisol within a 35 min reaction. The aptasensor has been validated on recirculating aquaculture system (RAS) fish tank water samples by the HPLC method and was able to detect changes in water cortisol induced by two different stress paradigms. This on-site deployable and non-invasive sensor offers opportunities for more efficient and real-time fish stress monitoring for the optimization of aquaculture practices.

Assessing anticancer, antidiabetic, and antioxidant capacities in green-synthesized zinc oxide nanoparticles and solvent-based plant extracts

Cancer and diabetes represent significant challenges in the field of biomedicine, with major and global impacts on public health. Acacia nilotica, commonly called 'gum arabic tree,' is recognized for its unique biomedical properties. The current study aimed to investigate the pharmacological potential of A. nilotica-based zinc-oxide nanoparticles (ZnO-NPs) in comparison to the ethanol and methanol-based extracts against cancer, diabetes, and oxidative stress. Green synthesis of ZnO-NPs was performed using barks of Acacia nilotica. Different techniques for the characterization of ZnO-NPs, including UV–Visible spectroscopy, Scanning Electron Microscopy, Fourier Transmission Infrared (FT-IR) spectroscopy, and X-ray Diffraction (XRD), were utilized. The morphological analysis of ZnO-NPs revealed that the fine NPs have mean particle sizes of 15 ± 1.5 nm. For the solvent based-extraction, leaves and barks were utilized and dissolved into ethanol and methanol for further processing. The MTT assay revealed that the optimum concentration of ZnO-NPs to inhibit the proliferation of liver cancer cell line HepG2 was 100 μg/mL where 67.0 % inhibition was observed; and both ethanol- and methanol-based extracts showed optimum inhibition at 100 μg/mL. The DPPH assay further demonstrated that 250 μg/mL of ZnO-NPs and 1000 μg/mL of both ethanol- and methanol-based extracts, as the optimum concentration for antioxidant activity (with 73.1 %, 68.9 % and 68.2 % inhibition respectively). The α-Glucosidase inhibition assay revealed that 250 μg/mL of ZnO-NPs and 10 μg/mL of both ethanol- and methanol-based extracts as the optimum concentration for antidiabetic activity (with 95 %, 93.7 % and 93.4 % inhibition respectively). The study provided interesting insights into the efficacy and reliability of ZnO-NPs for potential pharmacological application. Further research should be focused on examining specific pathways and the safety of ZnO-NPs in comparison to solvent-based extracts.

Electrochemical behavior and theoretical studies of arylazo (1-naphthyl-2-cyanoacetamide) derivatives as new corrosion inhibitors for Inconel 800 in chloride solution.

In this study, synthesize and insight the corrosion inhibition properties of two novel derivatives of 1-naphthyl-2-cyanoacetamide (NCDs) [2-cyano-2-((5,6-dimethyl-1H-benzo[d]imidazol-2-yl) diazenyl)-N (naphthalene-1-yl)acetamide] (NCD1) and [2-Cyano-N-(naphthalene-1-yl)-2-[(4,6-dimethyl-1H-pyrazolo [3, 4-b] pyridine-3-yl) hydrazono] acetamide] (NCD2). The characterization of the synthesized NCDs was confirmed through the utilization of Mass fragmentation analysis, 1H-NMR, andIR. The corrosioninhibitionperformanceofNCDsas a novel and environmentally safe corrosion inhibitor has been investigated by electrochemical techniques, a chemical technique, and theoretical studies for its anti-corrosion behavior of Inconel 800 in chloride medium. In addition, the surface morphology and inhibitor adsorption on the Inconel 800 surface were confirmed utilizing SEM, EDX, FTIR, and AFM. The advantages of NCDs include their low toxicity, environmental friendliness, ease of preparation, low odor, contain (N, O, and π-Bonds), and the inhibition efficiency elevated with decreasing solution temperature as well as inhibitor dose increase, yielding increased efficiencies of 91.8% and 95.7% for NCD1 and NCD2, respectively, at the optimum concentration of 21 10-6 mol. L-1 and 298 K temperature. An analysis of Tafel plots reveals that NCDs adhere to a mixed and isothermal Langmuir adsorption mechanism. Density Functional Theory (DFT) and Monte Carlo (MC) simulationmanifest the two compounds of NCDs can be adsorbed at the Fe (110) surface in a paralleled way, and can have a smaller energy gap (ΔE) value and exhibit higher efficiency. The experimental and theoretical findings confirm that the synthesized compounds obtained are capable of protecting the Inconel 800 from corrosion by creating an anti-corrosion coating on the surface.

Polyvinyl alcohol nanofibrous mat impregnated with ClCNTs/Fe2O3 nanocomposite for absorption of diesel oil in water

Abstract Oil contamination is one of the main sources of water pollution in the world. In this study, a sorption material that showed great promise as an absorbent for diesel oil in aqueous solution was developed. Chlorinated carbon nanotubes (CNTs) previously synthesized using a chemical vapor deposition (CVD) method were loaded with iron oxide nanoparticles via a co-precipitation method. The sorption materials were prepared by embedding ClCNTs/Fe2O3 nanocomposite into a polyvinyl alcohol (PVA) polymer matrix via electrospinning. The PVA mat containing only ClCNTs was also prepared for comparison and the maximum sorption capacity of 9.7 g/g was obtained. The optimum concentration of ClCNTs/Fe2O3 nanocomposite that gave uniform, and well-distributed nanofibers was 0.5 wt.%. Crosslinking the PVA/ClCNTs/Fe2O3 nanofiber mat with glutaraldehyde (GA) resulted in increased absorption capacity for oil of ~ 9.4 g/g in comparison with an absorption capacity of ~ 7.6 g/g attained with a pure nanofiber mat. The crosslinked nanofiber mat remained stable even after 60 min of oil absorption which proves that crosslinking assisted in increasing the affinity of PVA for oil by reducing the amount of OH groups through acetal formation making PVA less soluble to water. The oil sorption capacity of the prepared materials was not maintained even after two cycles indicating poor reusability. 

Meta-Topolin as an Effective Benzyladenine Derivative to Improve the Multiplication Rate and Quality of In Vitro Axillary Shoots of Húsvéti Rozmaring Apple Scion.

In vitro mass propagation of apple plants plays an important role in the rapid multiplication of genetically uniform, disease-free scions and rootstocks with desired traits. Successful micropropagation of apple using axillary shoot cultures is influenced by several factors, the most critical of which is the cytokinin included in the culture medium. The impact of medium composition from single added cytokinins on shoot proliferation of apple scion Húsvéti rozmaring cultured on agar-agar gelled Murashige and Skoog medium fortified with indole butyric acid and gibberellic acid was investigated. The optimum concentration for efficient shoot multiplication differs according to the type of cytokinin. The highest significant multiplication rate (5.40 shoots/explant) was achieved using 2.0 μM thidiazuron while the longest shoots (1.80 cm) were observed on the medium containing benzyladenine at a concentration of 2.0 μM. However, application of either thidiazuron or benzyladenine as cytokinin source in the medium resulted in shoots of low quality, such as stunted and thickened shoots with small leaves. In the case of benzyladenine riboside, the 8 μM concentration was the most effective in increasing the multiplication rate (4.76 shoots/explant) but caused thickened stem development with tiny leaves. In the present study, meta-topolin was shown to be the most effective cytokinin that could be applied to induce sufficient multiplication (3.28 shoots/explant) and high-quality shoots along with shoot lengths of 1.46 cm when it was applied at concentrations of 4 μM. However, kinetin was the least active cytokinin; it practically did not induce the development of new shoots. The superior cytokinin for in vitro axillary shoot development of apple scion Húsvéti rozmaring with high-quality shoots was the meta-topolin, but it may be different depending on the variety/genotype under study.

Thiol-ene Click Chemistry Synthesis of L-Cysteine-Grafted Graphene Oxide As a New Corrosion Inhibitor for Q235 Steel in Acidic Environment.

l-cysteine, as an eco-friendly and nontoxic corrosion inhibitor, was directly covalently linked to the carbon/carbon double bonds of the GO flakes by a thiol-ene click reaction to avoid decreasing the number of hydrophilic oxygen-containing polar functionalities. The corrosion inhibition performances of Cys-GO toward Q235 steel (QS) in diluted hydrochloric acid were studied by electrochemical methods. The corrosion was a charge transfer-controlled process, and Cys-GO manifested as a mixed-type corrosion inhibitor. The corrosion inhibition efficiency (η) for QS showed a first-increase-and-then-decrease trend with increasing Cys-GO concentrations. The optimum concentration of Cys-GO was 15 mg L-1, and the according η value was up to 90%. The Cys-GO adsorbed on the QS surface to form a protective barrier was responsible for the efficient corrosion inhibition. Langmuir adsorption isotherm model was fitted well with the experiment data, indicating a monolayer adsorption. Furthermore, the coordinate covalent bonds, π-back-donation effect, and electrostatic attraction were responsible for the Cys-GO adsorption on the QS surface.

Amelioration of protective organic layer using acenaphthene-based inhibitor responsible for excellent anti-corrosion performance: Experimental and computational perspectives

Despite the engineering promise offered by the co-existence of organic substances in protecting vulnerable metallic materials from corrosive environments, the interaction and formation mechanisms that induce the development of new materials with improved structural properties remain less understood. This study investigated the corrosion inhibitory properties of two acenaphthene derivatives, acenaphthylene-1,2‑dione (ACP) and 1,2-dihydroacenaphthylen-1-ol (DCP), as inhibitors for N80 steel in a 15 % HCl solution. The anticorrosive effectiveness of ACP and DCP compounds was evaluated through multiple research methods, including weight loss analysis, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), and surface characterization using scanning electron microscopy (SEM). The experimental findings demonstrate that ACP exhibits superior inhibition performance compared to DCP, with an inhibition efficiency of 93.54 % for ACP and 73.12 % for DCP at an optimum concentration of 5 × 10–3 M. EIS data show that the charge transfer resistance increases with higher concentrations of both compounds. PDP results indicate that ACP and DCP act as mixed-type inhibitors without altering the corrosion mechanism. The kinetic parameters of corrosion adsorption follow the Langmuir isotherm, highlighting a competition between physical and chemical interactions. To investigate how the geometric structures resulting from functional groups influence their interaction with the metal surface, theoretical calculations employing density functional theory (DFT), molecular dynamics (MD), and density-functional tight-binding (DFTB) were conducted. These calculations were aimed at gaining insights into the adsorption behavior of ACP and DCP on the metal surface and their interfacial mechanism. The calculations demonstrate that the molecule possessing twin donor atoms along with p-type orbitals of aromatic rings significantly influenced the formation of a protective film with a uniform distribution. This configuration exhibited superior corrosion performance compared to a molecule containing only one hydroxyl group (—OH). Theoretical calculations further suggest that ACP exhibits stronger adsorption ability, with the two oxygen atoms identified as the most reactive sites, indicating their tendency to donate electrons to the iron surface. The robust resonance-stabilized structure of ACP enhances the stability of the molecules, facilitating its interaction and adsorption onto the metal surface compared to the DCP inhibitor. Overall, the superior inhibition performance of ACP is attributed to the close bonding of twin donor fragments within the ACP molecule, forming a more compact adsorbed inhibitor film on the steel surface.

A method for screening salt stress tolerance in Indian mustard (Brassica juncea) (L.) Czern & Coss at seedling stage

Fifty-nine diverse Brassica juncea (Indian mustard) genotypes were used to find an effective screening method to identify salt tolerance at the germination and seedling stages. Salinity stress limits crop productivity and is difficult to simulate on farms, hindering parental selection for hybridization programmes and the development of tolerant cultivars. To estimate an optimum salt concentration for screening, seeds of 15 genotypes were selected randomly and grown in vitro at 0 mM/L, 75 mM/L, 150 mM/L, 225 mM/L, and 300 mM/L concentrations of NaCl in 2 replications in a complete randomized design. Various morphological parameters, viz., length of seedling, root and shoot length, fresh weight, and dry weight, were observed to determine a single concentration using the Salt Injury Index. Then, this optimum concentration (225 mM/L) was used to assess the salt tolerance of all the 59 genotypes in 4 replications while observing the same morphological parameters. With the help of Mean Membership Function Value evaluation criteria, the genotypes were categorized into 5 grades: 4 highly salt-tolerant (HST), 6 salt-tolerant (ST), 19 moderately salt-tolerant (MST), 21 salt-sensitive (SS), and 9 highly salt-sensitive (HSS). Seedling fresh weight (SFW) at 225 mM/L was found to be an ideal trait, which demonstrates the extent to which B. juncea genotypes respond to saline conditions. This is the first report that establishes a highly efficient and reliable method for evaluating the salinity tolerance of Indian mustard at the seedling stage and will facilitate breeders in the development of salt-tolerant cultivars.

High-efficiency removal of diclofenac sodium (DS) drug using chitosan-grafted-poly(acrylic acid-co-N-isopropylacrylamide)/kaolin clay hydrogel composite

ABSTRACT The current study mainly deals with the adsorptive removal of the diclofenac sodium (DS) drug from aqueous solution by the use of the kaolin-CS-g-poly(AA-co-NIPAM) composite. The synthesised composite was characterised by Fourier Transform infrared (FTIR), X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), thermogravimetric analysis (TGA), Transmission electron microscopy (TEM), energy dispersive X-Ray spectroscopy (EDS), atomic force microscopy (AFM), swelling % ratio and point of zero charge ( p H PZC ). The pHpzc of the composite was determined to be 4. The maximum adsorption capacity of 18.51 mg/g observed at the optimised conditions, including 0.1 g of kaolin clay dose, at neutral pH using composite dose of 0.06 g for 90 min. The optimum drug concentration was 500 mg/l for temperature of 30°C. Effect of the ionic strength on the adsorption capacity of the composite and its mechanism for DS drug removal has also been investigated. The process of drug adsorption on the prepared composite was chemical and data fits well to the pseudo second order and Langmuir model. Overall, the process was spontaneous and endothermic in nature.

Does using a higher dialysate sodium concentration result in lower sodium losses with dialysis treatments?

IntroductionMany dialysis centres prescribe a uniform dialysate sodium (DialNa) concentration, but as there is no consensus on the choice of a universal DialNa, we wished to determine dialysate sodium balance comparing DialNa of 140 and < 140 mEq/L.MethodsWaste dialysate was continuously collected during sessions and thoroughly mixed, and sodium was measured in both the waste and fresh dialysate. Sodium removal was calculated as the difference in concentrations, dialysate flow rate, session time and ultrafiltration.ResultsDialysate sodium balance was measured during 139 dialysis treatments (34 DialNa 140 versus 105 DialNa < 140, median 136 mEq/L), in 111 patients, 63% male, mean age 64.0 ± 16.2 years and 33.3% diabetic. There was no difference using the higher DialNa [net loss median 482 (238–573) versus 312 (124–599) mEq], ultrafiltration losses [226 (131–280) versus 204 (125–290)mEq] and non-ultrafiltration losses [217 (0–384) versus 173 (−90 to 350)mEq]. We also compared haemodiafiltration and haemodialysis (118 versus 23 sessions), and there were no differences in net loss [311 (91–608) versus 381 (167–597)], ultrafiltration [212 (127–290) versus 169 (110–258)mEq] and non-ultrafiltration losses [180 (−51 to 386) versus 192 (−74 to 387)mEq].ConclusionsAlthough most dialysis centres prescribe a universal dialysate sodium concentration, there is no consensus on the optimum universal concentration. We found no difference in net dialysate sodium balance when comparing patients dialysing with a dialysate sodium concentration of 140 or < 140 mEq/L. Similarly, we found no differences in dialysate sodium balance between haemodiafiltration and haemodialysis sessions.

Aequorivita sediminis sp. nov. and Aequorivita marina sp. nov., isolated from marine sediment.

Two Gram-stain-negative, rod-shaped, non-motile, strictly aerobic strains, forming yellow colonies and designated F6058T and S2608T, were isolated from marine sediment collected in Weihai, PR China. Both strains grow at 4-40 °C (optimum, 30-33 °C), pH 6.0-7.5 (optimum, pH 6.5) and in the presence of 0-7.0 % (w/v) NaCl. The optimum NaCl concentrations for strains F6058T and S2608T were 2.0 % and 2.5 %, respectively. Phylogenetic analysis of the 16S rRNA gene sequences indicated that strains F6058T and S2608T share an evolutionary lineage with members of the genus Aequorivita. The isolates exhibited a 16S rRNA gene sequence similarity of 96.7 % to each other. Strains F6058T exhibited the highest 16S rRNA gene sequence similarity to Aequorivita xiaoshiensis F64183T (98.8 %), and S2608T was most similar to Aequorivita capsosiphonis A71T (96.9 %). Iso-C15:0, anteiso-C15:0 and iso-C17:0 3-OH were the major fatty acids of strains F6058T and S2608T. The sole respiratory quinone of both isolates was menaquinone 6 (MK-6). The polar lipid profiles of the isolates both consisted of phosphatidylethanolamine and phosphoglycolipids; however, strain F6058T exhibited one glycolipid, one aminolipid and two unidentified polar lipids, and strain S2608T also had two glycolipids and one unidentified polar lipid. The DNA G+C contents of strains F6058T and S2608T were 34.6 % and 37.7 mol%, respectively. Based on their phenotypic, chemotaxonomic and genomic characteristics, strains F6058T and S2608T were considered to represent novel species of the genus Aequorivita, for which the names Aequorivita sediminis sp. nov. and Aequorivita marina sp. nov. were proposed. The type strains are F6058T (=KCTC 92653T=MCCC 1H01358T) and S2608T (KCTC 92652T=MCCC 1H01361T).

THE INFLUENCE OF BIOMASS CONCENTRATION OF CYANOBACTERIA ON SHOOT MULTIPLICATION OF POTATO PLANT, DESIREE CULTIVAR, IN VITRO

This study was conducted to determine the optimum concentration of the biomass of the cyanobacteria (Oscillatoria tenuis) which supports the MS medium prepared for shoot multiplication and rooting of potato plant Desiree cultivar from the culture of sprout explants via in vitro. The results showed that all concentrations of the cyanobacteria biomass extract + MS medium led to a 100% response to shoot formation after 60 days of culture. The 60% of the cyanobacteria biomass extract to the MS medium led to recording the largest number of shoots, reaching 8.8 shoots per explant, The 20% and 40% cyanobacteria biomass concentrations + MS medium treatments were significantly superior in average shoot length and number of leaves compared to the other two treatments, which amounted to 10.02 cm and 5.1 leaves per shoot and 10.48 cm and 5.0 leaves per shoot, respectively. The control treatment and the 20% cyanobacteria biomass concentration + MS Medium treatment did not produce any stolons from the shoots after 60 days of culture. The 40% and 60% cyanobacteria biomass concentration + MS medium treatments had stolons growing from the shoot site in contact with the nutrient medium. The stolon tips began to swell until microtubers were formed 60 days after culturing. The 60% cyanobacteria biomass concentration + MS Medium treatment was significantly superior in the average number of stolons, the number of microtubers, and the microtuber weight, which amounted to 4.6 stolons per shoot, 4.6 stolons per shoot, and 0.32g, respectively. The shoots were cultured in all treatments responded to rooting 60 days after culturing. The treatment 60% cyanobacteria biomass concentration + MS medium recorded the highest response to rooting of the shoots, the average number of roots, and root length which reached 100%, 5.8 roots per shoot, and. 6.2 cm, respectively.

Salt ions improve soybean protein isolate/curdlan complex fat substitutes: Effect of molecular interactions on freeze-thaw stability

Although emulsion gels show significant potential as fat substitutes, they are vulnerable to degreasing, delamination, and other undesirable processes during freezing, storage, and thawing, leading to commercial value loss in terms of juiciness, flavor, and texture. This study investigated the gel strength and freeze-thaw stability of soybean protein isolate (SPI)/curdlan (CL) composite emulsion gels after adding sodium chloride (NaCl). Analysis revealed that adding low salt ion concentrations promoted the hardness and water-holding capacity (WHC) of fat substitutes, while high levels displayed an inhibitory effect. With 40 mM NaCl as the optimum concentration, the hardness increased from 259.33 g (0 mM) to 418.67 g, the WHC increased from 90.59 % to 93.18 %, exhibiting good freeze-thaw stability. Confocal laser scanning microscopy (CLSM) and particle size distribution were used to examine the impact of salt ion concentrations on protein particle aggregation and the damaging effect of freezing and thawing on the proteoglycan complex network structure. Fourier-transform infrared spectroscopy (FTIR) and protein solubility evaluation indicated that the composite gel network structure consisted of covalent contacts between the proteoglycan molecules and hydrogen bonds, playing a predominant role in non-covalent interaction. This study showed that the salt ion concentration in the emulsion gel affected its molecular interactions.

Green Synthesis of Silver Nanoparticles Using Aqueous Fruit Peel Extract of Citrus aurantifolia: Optimization, Its Characterization and Stability Test

In this present study, silver nanoparticles were synthesized by green biological synthesis method using plant extract from fruit peel of Citrus aurantifolia as reducing agents. All the parameters in the synthesis of silver nanoparticles (AgNPs) were optimized to achieve a better yield, controlled size and stability of the particles. The biosynthesis of silver nanoparticles was monitored via UV-vis spectrophotometer and stability test was done. The resulting UV-Vis spectra of synthesized AgNPs from C. aurantifoliafruit peel extract (CAFPE) showed standard surface plasmon resonance band at 420 nm which indicated the presence of AgNPs. The optimum result was obtained with an optimum concentration at 4 mM AgNO3, leaving in a dark room temperature for 24 h and using a concentration 1:3 ratio (extract: silver nitrate). Moreover, the stability of the CAFPE-AgNPs was also observed after 30 days of synthesis and even up to 10 months, indicating optimization plays major role towards the stability fate of nanoparticles. The FTIR analysis showed possible functional groups of biomolecules that play roles in the bioreduction and capping of silver nanoparticles. In addition, it is believed that these parameters are highly suitable for bulk production of single spherical AgNPs with diameter 29.6- 45.2 nm confirmed via FESEM. Thus, the obtained results clearly suggest that optimization of silver nanoparticles may have important role in attaining a better yield and stability of metal nanoparticles, refraining back to its original structure or particles.

Effects of hydroxytyrosol on post-thaw quality of rooster sperm.

Semen cryopreservation is one of the most important reproduction techniques in the livestock and poultry industry. Cryopreservation induces cold stress, generating reactive oxygen species (ROS) and oxidative stress causing structural and biochemical damages in sperm. In this study, we evaluated the effects of the hydroxytyrosol (HT), as an antioxidant, at the concentrations of 0, 25, 50, and 100 μg/mL on post-thaw semen quality metrics in rooster. Semen samples were collected twice a week from 10 roosters (29 weeks), processed and frozen according to experimental groups. Different quality parameters, including total motility, progressive motility, viability, morphology, membrane integrity, and malondialdehyde were measured after thawing. Results showed that 25 and 50 μg/mL of HT produced the highest percentage of total motility (51.01 ± 2.19 and 50.15 ± 2.19, respectively) and progressive motility (35.74 ± 1.34 and 35.15 ± 1.34, respectively), membrane integrity (48.00 ± 2.18 and 46.75 ± 2.18, respectively) as well as viability (53.00 ± 2.17 and 52.50 ± 2.17, respectively) compared with the other groups (p < .05). The group with 25 μg/mL of HT showed the lowest significant (p < .05) MDA concentration (1.81 ± 0.25). Our results showed that the effect of HT was not dose-dependent and optimum concentration of HT could improve functional parameters of rooster sperm after freezing-thawing. These findings suggest that HT may have protective effects on the rooster sperm during the freezing-thawing process.

Recovery of Propionic Acid from Aqueous Phase using Alamine 336 in 1 - Octanol by Reactive Extraction

The by-products of carboxylic acids are useful in chemical industry, pharmaceutical industry, preservations, drug delivery towards a more economical energy efficient technology. Physical and chemical equilibria results are presented as equilibrium distribution, distribution co -efficient, extraction efficiency, loading ratio and volume percentage by varying concentrations. The distribution of propionic acid between aqueous phase and organic phase reaches equilibrium over a concentration range of 0.009 kmol/m3 – 0.055 kmol/m3 . The optimum TOA concentration is found to be 40% at which KD value for 1 - octanol is 16.7. The modified separation increases with decrease in TOA &amp; acid concentration and alamine loading with acid Z decreases with increase in alamine concentration in 1 – octanol. Optimum extraction efficiency is 43.82% for a conc. of 40% TOA at 0.2 kmol/m3.

Preparation and Evaluation of Metronidazole Tablets Produced with Different Binders Using Wet Granulation Method

In tablet formulation, binders are essential for ensuring proper powder mix, granulation and overall tablet quality. Variations in binder quality and concentration can impact drug bioavailability, strength and manufacturing processes. The inconsistency in bioavailability and therapeutic response of metronidazole from different manufacturers highlights the importance of binder selection in tablet formulation. This study evaluates the impact of different binding agents on tablet quality. The optimum binder concentration for each of the binders was assessed to obtain suitable concentration that was used to prepare metronidazole tablets. Metronidazole tablets were formulated with four different binder vis, acacia, gelatine, PVP, maize starch at 3% concentration using wet granulation method after which the tablet properties were evaluated. Metronidazole powder exhibited poor flow indices, as indicated by angle of repose: 39.92 ± 1.85, Carr’s compressibility index (CI): 20.13 ± 0.28 and Hausner’s ratio (Hr): 1.26 ± 0.01, whereas its granules exhibited good flow properties. The crushing strength (CS), friability (FR), disintegration time (DT) (CSFR/DT) ratio for batches showed values in 3% binder concentration, indicating higher strength as compared to other concentrations. There was a significant increase (P &lt; 0.05) in the CSFR/DT ratio for gelatine (2.22) in formulation F2 compared to maize starch in Formulation F4. The formulated tablets with the various binders have met with the British Pharmacopeial criteria of 80% drug release from uncoated immediate-release tablets. Amongst the four binders, gelatine was found to be the best in the formulation of robust metronidazole tablets by wet granulation method at an optimised concentration of 3% w/w. Tablets produced with gelatin exhibited greater mechanical strength than those produced with other binders, while also demonstrating a slightly longer DT. Metronidazole tablets produced with gelatine have met the British Pharmacopeial requirements including an acceptable in-vitro drug release profile.

Power generation characteristics and optimum alcohol concentration in bio-direct alcohol fuel cell using chitin family electrolyte

Direct alcohol fuel cells (DAFCs) have the potential to become the next-generation portable energy device. However, the development of DAFC requires the explore new electrolytes without fuel crossover. In this study, DAFC with bio-electrolyte have been fabricated and their characteristics have been investigated. Ethanol impermeability measurements revealed that the crossover of ethanol in the chitin and chitosan electrolytes is extremely low. This result indicates that the chitin family electrolyte has the potential of DEFC electrolytes. Furthermore, DAFCs using the chitin electrolyte have been investigated for various alcohol fuels (methanol, ethanol, 1-propanol, and 1-butanol fuels), and the optimum fuel concentrations to achieve the maximum power density in these DAFCs have been determined. In addition, these results and viscosity measurements clarify the optimum alcohol fuel concentration can be obtained by adding the water molecules required for the proton generating reaction to the water molecules required to stabilize alcohol in water.

Humic acid as eco‐friendly corrosion inhibitor for EH40 ship plate steel

In this study, a new type of green corrosion inhibitor, namely, sodium humate (SH), was extracted from humus soil, which is a natural humus plant, by dissolution‐neutralization, and then used for corrosion inhibition of low carbon steel in seawater. The corrosion inhibition performance of SH on low carbon steel EH40 in seawater was tested by weight loss method and electrochemical technology. The surface and corrosion products of low carbon steel were observed and analyzed by scanning electron microscope (SEM), atomic force microscope (AFM), contact angle and X‐ray photoelectron spectroscopy (XPS). The results show that SH is a mixed corrosion inhibitor, and the optimum concentration is 2 g L−1. At this concentration, the inhibition rate can reach 93.6%. It mainly affects the semi‐reaction of cathodic corrosion. By forming a corrosion protection layer with uniform adsorption on the surface of EH40 steel, EH40 steel becomes more resistant to seawater corrosion.

Effects of phytase inclusion in diets containing rice protein concentrate (RPC) on the nutrient digestibility, growth and chemical characteristics of rohu (Labeo rohita).

The objective of the current study was to assess the impact of dietary phytase supplementation on Labeo rohita fingerlings and to examine the effects on growth, nutrient digestibility and chemical characteristics of diets containing rice protein concentrate (RPC) as a major protein source. Six experimental diets were made, i.e., a positive control (fishmeal-based diet with no phytase), FM0; a negative control (RPC-based diet with no phytase), RPC0; and four supplemental phytase levels (250, 500, 1000, and 2000 FTU/kg). Fingerlings with an average weight of 9.42 ± 0.02 grams (mean ± SD) were randomly distributed into six experimental groups of three replicates, each containing 25 fish per tank (75 liters of water), provided with experimental diets at a rate equivalent to 5% of their body weight for 90 days, and uneaten feed was collected after 2 hours to determine feed consumption. The feces were collected before feeding to estimate digestibility. Phytase in combination with the RPC-based diet significantly (p < 0.05) enhanced phytate phosphorus in vitro hydrolysis; growth performance; nutrient (crude protein, crude fat, moisture and gross energy) and mineral (P, Ca, Mg, Na, K, Zn, Mn and Cu) digestibility; digestive enzyme (protease, lipase and amylase) activity; and mineral deposition up to 1000 FTU/kg phytase. However, the hepatosomatic and viscerosomatic indices and carcass composition were not influenced (p > 0.05) by phytase supplementation. Increasing phytase supplementation in the RPC-based diets led to a significant (p < 0.05) decrease in the serum biochemical parameters (alkaline phosphatase activity, aspartate aminotransferase, alanine aminotransferase), which resulted in improved liver health. In conclusion, phytase-supplemented RPC-based diets improved the growth, mineral/nutrient digestibility, digestive enzymes, serum biochemistry, and mineral deposition of L. rohita fingerlings up to 1000 FTU/kg. Broken line regression analysis revealed that the optimum phytase concentration in the RPC-based diet for L. rohita was 874.19 FTU/kg.