Concentrations Of Sodium Phosphate Research Articles

Boosting the visible-light-driven photocatalytic efficiency in porous Cu/TiO2 ceramic coatings

In this study, we examined how current density, sodium phosphate concentration, and the addition of copper sulfate to the supporting electrolyte affect PEO coatings on pure titanium. The chemical composition, morphology, and optical behavior of PEO coatings were extensively analyzed using scanning electron microscopy (SEM), X-ray diffraction (XRD), and UV–Vis diffuse reflectance spectroscopy (DRS). With an increase in current density from 6 to 18 A/dm2, the coating's pore size enlarges and the rutile phase content within the coatings increases. The coating created at 12 A/dm2 shows the highest photocatalytic activity and triggers a unique three-stage behavior in the voltage-time diagram. Adding 4 g/l of CuSO4 to the electrolyte resulted in the formation of an unwanted Cu-based precipitates, causing electrolyte instability. To stabilize it, potassium hydroxide was removed, and the base electrolyte concentration was adjusted. To address this issue, potassium hydroxide was eliminated from the supporting electrolyte. Subsequently, the concentration of the base electrolyte was optimized. Also, the synergistic influence of CuSO4 addition (4 g/l) to the supporting electrolyte at different concentrations of 5, 10, and, 15 g/l of trisodium phosphate on PA was investigated. The superior photocatalytic performance of the optimum coating created in the electrolyte containing 5 g/l trisodium phosphate and 4 g/l CuSO4 is attributed to its enhanced porous structure, along with the heterojunction between the anatase and rutile phases. These features significantly boost the available surface area and facilitate the efficient separation and transfer of photogenerated charge carriers. Ultimately, a mechanism for MB photodegradation was proposed based on the findings from Mott-Schottky analysis and DRS.

Extraction of Bovine Serum Albumin by Aqueous Two-Phase System Using PEG4000/Sodium Citrate and PEG8000/Sodium Phosphate

Aqueous Two Phase System (ATPS) or liquid-liquid extraction is used in biotechnology to recover valuable compounds from raw sources. In Aqueous Two-Phase Systems, many factors influence the Partition coefficient, K, (which is the ratio of protein concentration in the top phase to that in the bottom phase) and the Recovery percentage (Rec%). In this research, two systems of ATPS were used: first, polyethylene glycol (PEG) 4000/Sodium citrate (SC), and the second, PEG8000/ Sodium phosphate (SPH), for the extraction of Bovine Serum Albumin (BSA). The behavior of Rec% and K of pure (BSA) in ATPS has been investigated throughout the study by the effects of five parameters: temperature, concentration of polyethylene glycol (PEG4000 and PEG8000), the concentration of Sodium citrate or Sodium phosphate, pH, and the addition of sodium chloride as a supporting agent. The recovery percentage of BSA and its partition coefficient are significantly influenced by these factors to various degrees. The most influential variable in this study is PEG concentration for both systems. In addition to the PEG concentration, the stabilizing impact of NaCl is a crucial factor. The interaction between biomolecules and PEG gets more hydrophobic as the PEG concentration is raised. In the first system (PEG4000/SC), the maximum recovery percentage and partition coefficient were 98.99% and 97.69, respectively, at 31°C, PEG4000 concentration 1.5g/10 ml, Sodium citrate concentration 2.7 g/10 ml, pH 10, and 0.5 M NaCl concentration. While in the second system (PEG8000/SPH), the maximum recovery percentage and partition coefficient was 98.93% and 92.12, respectively, at 31oC, PEG8000 concentration 1.5 g/10 ml, Sodium phosphate concentration 2.4 g/10 ml, pH 10, and concentration of NaCl 0.5 M.

Application of Aqueous Two-Phase Systems in the Extraction of Bovine Serum Albumin

Request PDF |Protein partitioning in an Aqueous Two-Phase System (ATPS) has been found to be a powerful method for extracting and separating mixtures of biomolecules. In Aqueous Two-Phase Systems, many factors influence the Partition coefficient (K) (which is the ratio of protein concentration in the top phase to that in the bottom phase) and the Recovery percent (Rec%). Two systems of ATPS were used: first, polyethylene glycol (PEG4000)/sodium phosphate (SPH), and second, PEG4000/Dextran. The behavior of Rec% and (K) of pure Bovine Serum Albumin (BSA) in (ATPS) has been investigated throughout the study of the effects of five parameters: (temperature (T), the concentration of polyethylene glycol (PEG4000), the concentration of sodium phosphate or Dextran, pH, and the addition of sodium chloride as a supporting agent). In both systems, pH was the more significant parameter on a Recovery percent (Rec%) and partition coefficient (K). In the first system, the maximum (Rec%) and (K) was 98.08% and 50.99, respectively, at a temperature of 31°C, the concentration of PEG4000 of 1.5 g/10 ml, the concentration of sodium phosphate at 2.4 g/10 ml, pH 10, and the concentration of NaCl at 0.5 M. While in the second system, the parameter that has a more significant effect on (Rec%) and (K) was the temperature. The maximum (Rec%) and (K) were 97.54% and 39.7 respectively at a temperature of 31°C, with a concentration of PEG4000 1.5 g/10 ml, the concentration of Dextran 2.4 g/10 ml, pH 5, and concentration of NaCl at 0.1 M.

Biochemical and histological investigation on the protective effect of poly-herbal extract in high salt diet-fed male Wistar rats

BackgroundThrough different mechanisms, excessive intake of dietary salt has been documented as a risk factor for the development of elevated blood pressure and organ dysfunction. Therefore, this study evaluated the efficacy of combined extracts of four medicinal plants against high salt diet-induced succinate dehydrogenase depletion and alteration in vital organ (kidney, liver, and cardiac) hemostasis. MethodsThirty-five male Wistar rats with an average weight of 130 g were divided into 5 groups of 7 animals each. Group 1 and 2 rats were fed with normal rat chow (NRC) and 16% high salt diet (HSD) only respectively. Rats in groups 3, 4, and 5 were fed with 16% HSD and 800, 400, and 200 mg/kg poly-herbal extract (PHE), respectively, once daily for 4 weeks. The concentration and activities of creatinine, urea, sodium, magnesium, chloride, potassium, albumin, globulin, total protein, and alkaline phosphate (ALP) were estimated in the serum. Aspartate and alanine aminotransferases (AST and ALT), lactate dehydrogenase (LDH), succinate dehydrogenase (SDH) were estimated in the serum, liver, and aorta. The result revealed that the combined extract significantly (p < 0.05) lowered HSD-induced elevated serum concentration of kidney function markers and electrolytes. More so, a significant (p < 0.05) reduction in serum and tissue activities of liver and cardiac function markers was demonstrated by the poly-herbal extract. No significant changes were observed in serum albumin and globulin level, however total protein and tissue activities of SDH were significantly (p < 0.05) elevated by the PHE. The histopathological examination showed to a large extent, the extract conferred significant protection on the cytoarchitecture of the kidney, liver, and aorta. ConclusionConclusively, combined plants extract protected against high salt diet-induced biochemical and histological derangement in male Wistar rats.

Effects of Ice Massage Prior to an Iontophoresis Treatment Using Dexamethasone Sodium Phosphate.

Low current intensity iontophoresis treatments have increased skin perfusion over 700% from baseline potentially altering drug clearance from or diffusion to the targeted area. To determine the effects of a preceding 10-minute ice massage on subcutaneous dexamethasone sodium phosphate (Dex-P) concentration and skin perfusion during and after a 4-mA iontophoresis treatment. Controlled laboratory study. Research laboratory. Twenty-four participants (male = 12, female = 12; age = 25.6 [4.5]y, height = 173.9 [8.51]cm, mass = 76.11 [16.84]kg). Participants were randomly assigned into 2 groups: (1)pretreatment 10-minute ice massage and (2)no pretreatment ice massage. Treatment consisted of an 80-mA·minute (4mA, 20min) Dex-P iontophoresis treatment. Microdialysis probes (3 mm deep in the forearm) were used to assess Dex-P, dexamethasone (Dex), and its metabolite (Dex-Met) concentrations. Skin perfusion was measured using laser Doppler flowmetry. Microdialysis samples were collected at baseline, at conclusion of treatment, and every 20 minutes posttreatment for 60minutes. Samples were analyzed to determine Dex-Total (Dex-Total = Dex-P + Dex + Dex-Met). Skin perfusion was calculated as a percentage change from baseline. A mixed-design analysis of variance was used to determine Dex-Total and skin perfusion difference between groups overtime. There was no difference between groups (P = .476), but [Dex-Total] significantly increased over the course of the iontophoresis and posttreatment time (P < .001). Dex-P was measured in 18 of 24 participants with a mean concentration of 0.67 (1.09)μg/mL. Skin perfusion was significantly greater in the no ice treatment group (P = .002). Peak skin perfusion reached 27.74% (47.49%) and 117.39% (103.45%) from baseline for the ice and no ice groups, respectively. Ice massage prior to iontophoresis does not alter the tissue [Dex-Total] even with less skin perfusion.

Perbandingan Teknik Aerasi dan Ultrasonikasi Gelasi Ionik Nanopartikel Deksametason Natrium Fosfat

Alginate, a biocompatible and biodegradable natural polymer, has been widely used as a drug molecular carrier using ionic gelation methods (crosslinking). One of the factors that must be taken into account in its preparation is the mechanical effect. The purpose of this study was to explain the preparation process and the characteristics of the calcium alginate crosslinkers as dexamethasone sodium phosphate carriers with low energy and high energy techniques. Nanosuspension is made in six formulas using 3 techniques: low energy (aeration), high energy (ultrasonication), low and high energy (aeration and ultrasonication) with a fixed concentration of dexamethasone sodium phosphate and sodium alginate, that is 0,2% and 0,1%, with 0,02% and 0,2% of calcium chloride. Determination of particle size, zeta potential, and morphology of nanoparticles using Particle Size Analyzer (PSA) and Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM). Determination of encapsulation efficiency using UV/Vis spectrophotometer and statistical analysis using MANOVA test. Synthesis of nanosuspension using a combination of low and high energy (aeration and ultrasonication) results in the most optimal characteristics with particle size value of 352.90 ± 6.10 nm, homogenized polydispersity index (0,52 ± 0,04), optimal potential zeta -44,40 ± 0,4 mV, the encapsulation efficiency of 49,5 - 74,8% and spherical particle shape. It can be concluded that the preparation using a combination of low and high energy is the most optimal preparation result.

Separation of monoclonal antibody monomer-dimer mixtures by gradient elution with ceramic hydroxyapatite.

Modeling the chromatographic separations of proteins at manufacturing scale is important since downstream processing costs are often dominant. At such scales, the columns are highly overloaded heightening the challenge of predicting performance. In this work, the separation of a monoclonal antibody monomer-dimer mixture is conducted by gradient elution chromatography with ceramic hydroxyapatite (CHT) columns Type I and Type II under overloaded conditions. Phosphate gradients are shown to be preferable over sodium chloride gradients since the latter result in undesirable pH transitions generated within the column itself. Using sodium phosphate gradients separation is obtained with both CHT types, achieving approximately 90% recovery at 99% monomer purity starting with a mixture containing 30% dimer at total protein loads up to 30 mg/mL. Because of its higher binding capacity, even higher loadings can be obtained with CHT Type I without monomer breakthrough. A hybrid model is developed to describe the separation. The model, based on an empirical description of two-component, competitive isotherms at low sodium phosphate concentration coupled with the stoichiometric displacement model at higher sodium phosphate concentrations, is in good agreement with the experiments using the linear driving force (LDF) approximation to describe adsorption/desorption kinetics. The same LDF rate coefficient predicts the separation at loadings between 0.8 and 30 mg/mL. The model developed in this work can be used as a general tool to optimize operating conditions, understand what factors limit performance, and compare different operating modes.

Partial purification of fibrinolytic and fibrinogenolytic protease from Gliricidia sepium seeds by aqueous two-phase system

Abstract Fibrinolytic proteases are enzymes that provide a promising alternative to drugs for thrombolytic therapy, since they degrade fibrin, the major component of blood clots. Aqueous two-phase systems (ATPS) using polyethylene glycol (PEG) 8000 and sodium phosphate were used to select optimal conditions for extracting a cysteine protease with fibrinolytic and fibrinogenolytic activity from the legume Gliricidia sepium PBSGS. For this purpose, extraction tests were conducted in accordance with a 24-factorial design, in which concentrations of PEG (CPEG), molar mass of PEG, concentrations of sodium phosphate (CPHO) and pH were used as independent variables, and partition coefficient, activity yield and purification factor as responses. The best results in terms of enzyme partial purification were obtained at CPEG of 12.5% (w/w), CPHO of 15% (w/w) and pH 8.0, which guaranteed a purification factor of 6.26, a partition coefficient of 1.32 and a yield of 141.57%. The results clearly showed preferential protease partitioning to the PEG-rich top phase. The enzyme, which was able to degrade human fibrinogen, was characterized as a cysteine protease (66 kDa) and exhibited optimum activity temperature of 60 °C and pH of 8.0; in addition, its activity was increased in the presence of potassium, iron, zinc and sodium ions and reduced in the presence of calcium ion. The results obtained suggest potential of ATPS-partially purified protease in thrombolytic treatment, which will be the object of future investigation.

Isoelectric point-amyloid formation of α-synuclein extends the generality of the solubility and supersaturation-limited mechanism.

Proteins in either a native or denatured conformation often aggregate at an isoelectric point (pI), a phenomenon known as pI precipitation. However, only a few studies have addressed the role of pI precipitation in amyloid formation, the crystal-like aggregation of denatured proteins. We found that α-synuclein, an intrinsically disordered protein of 140 amino acid residues associated with Parkinson's disease, formed amyloid fibrils at pI (= 4.7) under the low-sodium phosphate conditions. Although α-synuclein also formed amyloid fibrils at a wide pH range under high concentrations of sodium phosphate, the pI-amyloid formation was characterized by marked amyloid-specific thioflavin T fluorescence and clear fibrillar morphology, indicating highly ordered structures. Analysis by heteronuclear NMR in combination with principal component analysis suggested that amyloid formation under low and high phosphate conditions occurred by distinct mechanisms. The former was likely to be caused by the intermolecular attractive charge-charge interactions, where α-synuclein has +17 and −17 charges even with the zero net charge. On the other hand, the latter was caused by the phosphate-dependent salting-out effects. pI-amyloid formation may play a role in the membrane-dependent amyloid formation of α-synuclein, where the negatively charged membrane surface reduces the local pH to pI and the membrane hydrophobic environment enhances electrostatic interactions. The results extend the supersaturation-limited mechanism of amyloid formation: Amyloid fibrils are formed under a variety of conditions of decreased solubility of denatured proteins triggered by the breakdown of supersaturation.

Morphological modification and corrosion response of MgO and Mg3(PO4)2 composite formed on magnesium alloy

During the last decade, much effort has been poured into aiming at controlling the surface morphologies of inorganic layer via plasma electrolysis that exhibited good functional properties. In this work, the 3-dimensional structures were formed on magnesium alloy by means of self-assembly. To this end, the porous inorganic layer was modified additionally by immersion in solutions with different ratios of albumin (ALB) and sodium phosphate (SP). The porous layer was transformed into the flower-like structure when the amount of ALB was relatively higher than SP. As the relative concentration of SP increased, the formation of the rod-like structure was favored, covering the entire surface of porous inorganic layer. These findings were attributed mainly to the electrostatic interactions between albumin and Mg3(PO4)2 where the competitive adsorption between ALB and PO4−3 on oxide surface took place. Since ALB adsorption was hindered by the presence of PO4−3, the rod-like structure controlled at relatively high concentration of SP was responsible for excellent electrochemical stability. The shape-controlled synthesis of either flower- or rod-like structures present provided a green approach desirable for electrochemical applications of magnesium-based alloys.

Statistical and sequential (fill-and-draw) approach to enhance rhamnolipid production using industrial lignocellulosic hydrolysate C6 stream from Achromobacter sp. (PS1)

Statistical optimization using industrial rice-straw hydrolysate (C6 stream) containing 5.0% total sugars was carried out for enhancing the rhamnolipid production from Achromobacter sp. (PS1) with subsequent adoption of a sequential fermentation approach with fill-and-draw operation for further increment. The interactive effects of six influential variables obtained from one-factor-at-a-time approach as sodium nitrate, yeast extract, ferrous sulphate, phosphate concentrations and agitation in presence of lignocellulosic hydrolyzed sugars as a basal medium using central composite design revealed the experimental rhamnolipid yield of 5.46 g/L at optimum conditions of total sugars 40 g/L (w/v), sodium nitrate 6.0 (g/L), yeast extract 2 (g/L), ferrous sulphate 0.2 (mg/L) and phosphate 1000 mM at 100 rpm at 30 °C in 8 days. The sequential approach further resulted in an overall yield of 19.35 g/L of rhamnolpid in five sequential-cycles with an increase of 258% over the batch process on account of nutrients replenishment and dilution of toxic by-products.

Leaching kinetics of scheelite concentrate with sodium hydroxide in the presence of phosphate

Abstract The reaction kinetics for the leaching of low-grade scheelite concentrate was investigated in an autoclave with sodium hydroxide in the presence of phosphate. The effects of stirring speed (300−600 r/min), reaction temperature (353−383 K), sodium hydroxide concentration (1.69−6.76 mol/L) and phosphate concentration (0.68−1.69 mol/L) on the WO3 dissolution ratio were studied. The results showed that the WO3 dissolution ratio was practically independent of stirring speed, while it increased with increasing the reaction temperature, and the concentrations of sodium hydroxide and phosphate. The experimental data were consistent with the shrinking core model, with a surface chemical reaction as the leaching rate-determining step. The apparent activation energy was calculated as 49.56 kJ/mol, and the reaction orders with respect to the concentrations of sodium hydroxide and phosphate were determined as 0.27 and 0.67, respectively. The kinetics equation of the leaching process was established.

RELEASE BEHAVIOR OF DICHLORPROP FROM ZN/AL-LDH-DICHLORPROP NANOCOMPOSITE INTO CHLORIDE, CARBONATE AND PHOSPHATE SOLUTIONS

A release study of dichlorprop phenoxyherbicides from the interlayer of a Zn/Al-layered double hydroxide-dichlorprop nanocomposite was performed with various concentrations of sodium chloride, sodium carbonate and sodium phosphate and a mixture of sodium chloride, sodium carbonate and sodium phosphate in aqueous solution. The release study of dichlorprop showed that release is dependent on the concentration of the aqueous solution. The accumulated release percentage of dichlorprop phenoxyherbicides into the solution was found to be higher in solutions containing carbonate, phosphate, and a mixture of carbonate or phosphate anions. Confirmation of the release process was confirmed by the PXRD pattern of the powder recovered from highly concentrated solutions of sodium chloride, sodium carbonate, and sodium phosphate with basal spacing of 7.8 Å, 7.6 Å and 7.4 Å, is due to chloride, carbonate, and phosphate intercalation, respectively. The kinetic study revealed that dichlorprop release into sodium carbonate and sodium phosphate solutions is governed by pseudo-second order kinetics, while release into sodium chloride solution is governed by parabolic diffusion. This study shows that a layered double hydroxide might be used as a host for the controlled release of the phenoxyherbicide dichlorprop.

Optimization of AZ80 magnesium alloy anodizing by using Taguchi method

Abstract In this study, anodizing of AZ80 magnesium alloy by using different parameter were investigated. The Taguchi method was employed to investigate the effect of process parameter, namely anodizing potential, treatment time and electrolyte concentration on corrosion behaviour on anodized AZ80 magnesium alloy. The data were statistically analysed using Minitab software to predict the optimal combination of processing parameter. It was found that the factor that give biggest influence to the corrosion resistance of the anodic film is voltage, followed by Sodium Hydroxide, Sodium Silicate, Sodium Phosphate and finally treatment time. The optimum parameter is achieved by combination of 10 min of treatment time, 30V of potential, and 80, 40 and 30 g/L concentration of potassium hydroxide, sodium silicate and sodium phosphate.

Toxic effect and physiological disruption of sodium phosphate to the quagga mussel (Dreissena bugensis).

Phosphorous is an essential nutrient for all forms of life; however, the question of toxicity to aquatic species remains largely unanswered, despite many systems that exceed natural phosphorus loads. This study determined the ecotoxicological threshold concentration of phosphorus to the freshwater bivalve Dreissena bugensis using a 96-h bioassay. Sublethal, medial lethal, and lethal levels of sodium phosphate to D. bugensis were found to be 125, 260, and 476ppm. Physiological biomarkers such as the oxygen consumption and filtration rate were estimated by exposing D. bugensis to five different sublethal concentrations (25, 50, 75, 100, and 125ppm) of sodium phosphate for 96h. Both oxygen consumption and filtration rate gradually declined with increasing exposure concentrations and durations, which was significant (α < 0.05) for 75, 100, and 125ppm of sodium phosphate concentrations. Based on the feeding rate and oxygen consumption endpoints, the no-observed effect concentration and the low observed effect concentration were 25 and 75ppm, respectively. Maximum acceptable toxicant concentration of sodium phosphate was 43.3ppm. Measured environmental concentration (MEC) of total phosphorus (0.015ppm; n = 6) was obtained from seasonal field assessments in Saginaw Bay during the years 2008 to 2010. An assessment factor of 1000 was used for calculating the predicted no effect concentration (PNEC) of 0.025ppm. Risk quotient (RQ) of "0.6" was therefore established using MEC/PNEC (real risk) ratio. Binary ecological classification (RQ < 1) suggested that there is no appreciable risk of phosphorus to D. bungensis in the Saginaw Bay of Lake Huron of Laurentian Great Lakes.

Biomass and lipid production of marine diatom Chaetoceros ChTA at different nutrient concentrations

Microalgae, especially diatom, are an optimal resource of polyunsaturated fatty acids (PUFAs). Recently, the new industrial scale culture systems are being developed for the purpose of producing the large amounts of biomass for biofuel, medicinal, cosmetical production. However, an economic utilization system needs to be standardized for the optimal production of the resources. In this way, manipulation of culture conditions (physicochemical factors) represents a solution to increase the lipid yield. The strain Chaetoceros ChTA is one of the high potential lipid strains, isolated from Thuan An coastal zone, Thua Thien Hue province. This paper deals with the growth and total lipid content of the marine diatom strain, Chaetoceros ChTA at different concentrations of sodium nitrate, sodium phosphate and sodium silicate under the laboratory condition. In addition, the fatty acid composition of the strain Chaetoceros ChTA growing in f/2 medium (control formula) was also analyzed. The result showed that this diatom strain successfully growed with maximum biomass production of 0.482g/L at the 112.50 mg/L of sodium nitrate meanwhile maximum total lipid content of 25.62% dry cell weight was recorded in the medium amended with 2.13 mg/L sodium phosphate. The fatty acid composition of this strain in f/2 medium (control) was analysed through GC-MS and the result showed that the saturated fatty acid content was 32.3% while the content of unsaturated fatty acid was 65.9% of the total fatty acid (TFA). The fatty acid composition also contains a significant amount of EPA (14.33%) and DHA is suitable for navigation use them as functional foods, pharmaceuticals and feed supplements for animals in aquaculture.

Physicochemical properties of frozen Alaska pollock fillets and surimi as affected by various sodium phosphates

The physicochemical characteristics of frozen Alaska pollock fillet and surimi were investigated as affected by various phosphates (sodium tripolyphosphate (STPP), tetrasodium pyrophosphate (TSPP), trisodium pyrophosphate, sodium hexametaphosphate, and disodium phosphate anhydrous). Both phosphate-injected fillets and phosphate-added surimi along with cryoprotectant (5% sugar and 4% sorbitol) were subjected to 0, 3, and 9 freezing/thawing (F/T) cycles. The concentration of sodium phosphate retained in fillet was adjusted to 0.3% using poking (6 times), soaking (10 min), and draining (2 min). Trimethylamine-N-oxide demethylase (TMAOase) activity and formaldehyde (FA) concentration were found significantly higher in fillet than in surimi. As STPP and TSPP were more effective to control TMAOase activity of fillet and surimi than other phosphates, during repeated F/T, lower TMAOase activity, lower FA content, lower drip/cook loss, and higher salt-soluble protein extractability were observed. Texture toughness in fillet and surimi with STPP and/or TSPP were lower than other treatments. Practical applications Two phosphates (STPP and TSPP) effectively minimized both freeze-induced and TMAOase-caused denaturation in fillets and surimi. As a result, texture toughening was reduced. TMAOase activity and FA content were significantly lower in surimi than fillets.

Buffering action of acetate on hydrogen production by Ethanoligenens harbinense B49

800x600 The buffering effect of acetate on hydrogen production during glucose fermentation by Ethanoligenens harbinense B49 was investigated compared to phosphate, a widely used fermentative hydrogen production buffer. Specific concentrations of sodium acetate or phosphate were added to batch cultures, and the effects on hydrogen production were comparatively analyzed using a modified Gompertz model. Adding 50 mM acetate or phosphate suppressed the hydrogen production peak and slightly extended the lag phase. However, the overall hydrogen yields were 113.5 and 108.5 mmol/L, respectively, and the final pH was effectively controlled. Acetate buffered against hydrogen production more effectively than did phosphate, promoting cell growth and preventing decreased pH. At buffer concentrations 100-250 mM, the maximum hydrogen production was barely suppressed, and the lag phase extended past 7 h. Therefore, although acetate inhibits hydrogen production, using acetate as a buffer (like phosphate) effectively prevented pH drops and increased substrate consumption, enhancing hydrogen production. Normal 0 21 false false false ES X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:Tabla normal; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:Times New Roman,serif;}

A combined sodium phosphate and sodium sulfide pretreatment for enhanced enzymatic digestibility and delignification of corn stover

Na3PO4 and Na2S were employed as efficient alkaline catalysts for the pretreatment of corn stover. To systematically obtain optimal conditions, the effects of critical pretreatment parameters including sodium phosphate concentration (1–4%), sulfidity (0–20%), pretreatment temperature (100–120°C), and reaction time (20–60min) on the reducing sugar yield of pretreated substrates were evaluated in a lab-scale using the response surface methodology. Pretreated under the sodium phosphate concentration of 4%, sulfidity of 10%, temperature of 120°C, and reaction time of 40min, the reducing sugar yield and glucose yield of the pretreated corn stover achieved 91.11% and 64.01%, respectively, with a moderate enzyme loading of 30FPU/g substrate. Additionally, a strong correlation (R2=0.971 and R2=0.954) between the delignification and the reducing sugar yield (or glucose yield) was observed by this pretreatment method. These results evidently support that the combined Na3PO4-Na2S pretreatment is an effective and feasible method for processing lignocellulosic biomass.

Paclitaxel Loaded Nanoliposomes in Thermosensitive Hydrogel: A Dual Approach for Sustained and Localized Delivery

In an attempt to improve the localized paclitaxel delivery, carrier based thermoresponsive chitosan hydrogel was exploited in the present study. Nanoliposomes as carrier for paclitaxel were prepared and optimized in strength of 6 mg/ml similar to marketed paclitaxel formulation. The chitosan solution (2% w/v) mixed with different concentrations of dibasic sodium phosphate (DSP) was evaluated as thermoresponsive systems in terms of gelling temperature and time. Finally, the drug loaded nanoliposomes were incorporated in optimized chitosan- DSP hydrogel base to form nanoliposomal in situ thermosensitive hydrogel formulations having dual mechanism of protection and release. The optimal formulation containing DSP was selected on the basis of minimal gelation temperature (37±0.8 ºC) and time (6.7±0.3 min). In vitro drug release experiment illustrated that developed formulation manifested sustained release action in which drug release was extended for more than 72 h compared to marketed formulation. In addition, optimized nanoliposomal hydrogel demonstrated enhanced biological half-life of 15.7±1.5h, depicting maintenance of constant plasma concentration in contrast to marketed formulation that showed the half-life (t1/2) of 3.6±0.4h. The in vivo anti tumor activity tested using EAC model also corroborated the above findings that developed formulation was having significant higher anti-tumor activity and reduced toxicity than the marketed formulation. Tumor volume was found to reduce upto 89.1±3.5% by treatment with in situ hydrogel formulation. The histopathological study of tumor also demonstrated the better safety and efficacy of developed formulation in comparison to marketed paclitaxel formulation. Our results suggest that carrier based chitosan hydrogel could be an efficacious vehicle for sustained and localized delivery of paclitaxel.