Percentage Swelling Research Articles

Correlation between seminal lead and cadmium and seminal parameters in idiopathic oligoasthenozoospermic males

IntroductionThe exact causes of the decline in semen quality are not yet known, environmental factors have been considered to play an important role. Lead (Pb) and Cadmium (Cd) are two of the well-known reproductive toxicants to which humans are exposed occupationally and environmentally and can lead to negative effects on the testicular functions. The aim of this study was to evaluate lead and cadmium levels in seminal plasma of men with idiopathic oligoasthenozoospermia in comparison to fertile healthy controls and to correlate these levels with conventional semen parameters, sperm hypo-osmotic swelling (HOS) percentage, sperm DNA fragmentation percentage, and semen reactive oxygen species (ROS) levels.Material and MethodsThirty infertile male patients with idiopathic oligo and/or asthenozoospermia and thirty healthy fertile men, which was the control group, were included in the study. Lead and cadmium levels in seminal plasma, semen parameters, sperm HOS, sperm DNA fragmentation percentage and semen ROS assay were measured in all subjects.ResultsThere was a significant increase in seminal lead and cadmium levels among infertile males in comparison to controls. There were significant negative correlations between seminal lead and cadmium levels on one hand and certain semen parameters especially progressive sperm motility and vitality (HOS). Importantly, significant positive correlations were noted between seminal lead and cadmium levels on one hand and sperm DNA fragmentation percentage and semen ROS level in infertile men and controls on the other hand.ConclusionsThus, men with idiopathic male infertility had higher levels of lead and cadmium in their semen which correlated with impairment of sperm motility and vitality percentages and more importantly with higher sperm DNA fragmentation% and semen ROS level.

Synthesis of 4-Acryloylmorpholine-based Hydrogels and Investigation of their Drug Release Behaviors

In this study, hydrogels based on an amphiphilic, water soluble, bisubstituted and biocompatible acrylamide derivative, namely 4-acryloylmorpholine (4-AcM), were prepared. 4-AcM based hydrogels with different compositions were synthesized by photopolymerization from the mixtures of poly(ethylene glycol) diacrylate (PEG-DA) and poly(2-hydroxy ethyl methacrylate) (HEMA), and characterized by Fourier transform infrared spectroscopy (FTIR). Gel percentage and equilibrium swelling ratios were determined. Images obtained by scanning electron microscopy (SEM) confirmed porous structure of the hydrogels. Ciprofloxacin.HCl was chosen as a model drug in order to understand the drug loading and release behaviors of the hydrogels. As 4-AcM content increased, higher drug release was observed. On the other hand, the increase in crosslinking density due to PEG-DA content resulted in the swelling decrease of the hydrogel and reduced the diffusion of the drug.

Water and dye sorption studies of novel semi IPNs: Acrylamide/4-styrenesulfonic acid sodium salt/peg hydrogels

In this study, it has been investigated that the incorporation of poly(ethylene glycol), (PEG) and 4-styrenesulfonic acid sodium salt, (NaSS) into acrylamide, (AAm) hydrogel during free radical solution polymerization synthesis. Poly (ethylene glycol)dimethacrylate, (PEGDMA) was used as a multifunctional crosslinker in polymerization. The main purpose of this study was to combine both monomers and a polymer in a new polymeric system. Dye sorption properties of hydrogels and semi IPNs were investigated by using cationic dye such as Union Green B (Janus Green B, UGB). Swelling and sorption studies were carried out at 25°C. For structural characterization, FTIR analysis was made. The equilibrium percentage swelling (Seq%) ranges are 660–1330% for AAm/NaSS hydrogels and 580–1310% for AAm/NaSS/PEG semi IPNs. To determine the sorption behaviors of cationic dye UGB, some sorption parameters such as sorption capacity (q), adsorption percentage (Ads%) and partition coefficient (Kd) of the hydrogels were investigated. Binding characterization has been studied by Langmuir linearization method. The sorption capacity values of the hydrogel systems were changed between 1.24 × 10−4 and 4.05 × 10−4 mol g−1. The values of Ads% of the hydrogels were changed among 18−67%, and the values of Kd of the hydrogels were between 0.22 and 2.02. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers

Pembuatan Membran Polimer Elektrolit Berbasis Polistiren Akrilonitril (SAN) untuk Aplikasi Direct Methanol Fuel Cell

In this study, electrolyte membranes based on polystyrene acrylonitrile (SAN) for Direct Methanol Fuel Cell applicationwere prepared. The preparation was carried out in two steps. The first step was introduction of additives, silicaand zeolite, as reinforcing agent on SAN, to obtain silica-reinforced SAN membrane, specified as SAN-Si, andzeolite-reinforced SAN membranae, specified as SAN-Z. The two reinforced membranes were then subjected tosulphonation using sulphuric acid, and the sulphonated membranes are specified as S-SAN-Si and S-SAN-Z,respectively. The characteristics of the membrane were described in terms of the degree of sulphonation, ionicconductivity, methanol permeability, and percentage of swelling in water and methanol. The results obtaineddemonstrated that additives result in significant reduction of methanol crossover, as reflected by lower values ofmethanol permeability than that obtained for the membrane without additive. It was also found that zeolite functionsrelatively better than silica. For zeolite-modified membrane (S-SAN-Z) the ionic conductivity of 10.05 x 10 -6 S/cmwas achieved. The membrane also marked by methanol permeability of 0.52 x 10 -6, percentage of swelling of 5.12%in water and 2.58% in methanol. Thermal analysis using DSC technique revealed changes in glass transition fromthe original sample, in which the glass transition of the original sample, SAN, (55 0C), sulphonated SAN, S-SAN,(83.360C), silica-modified membrane S-SAN-Si (79.860C), and zeolite-modified membrane S-SAN-Z (79.290C). Additionof additive was also found to influence the surface characteristics of the membranes as revealed by SEM analysis,in which the surface changed from smooth for the original sample into rough for the reinforced samples with bothadditives.

Limitation of the Artificial Neural Networks Methodology for Predicting the Vertical Swelling Percentage of Expansive Clays

AbstractThe general swelling model has recently been updated in Israel by applying the Excel-solver command (ESC) analysis to new local test results from 897 undisturbed specimens. In this analysis, the goodness-of-fit statistics obtained classify the category of their associated regression only as fair. Thus, it seems necessary to explore the possibility of enhancing the outputs of this regression analysis by applying the artificial neural networks (ANN) methodology to the same 897 undisturbed specimens. However, it is shown that the use of the ANN outputs should be accompanied by an additional check to ensure that they follow the expected physical swelling behavior, as characterized by the index properties of the soil. The ANN methodology applied in this paper is similar to previous studies in geotechnical engineering. Different models were tested using the same database (i.e., the same 897 undisturbed specimens). The statistical fit of the ANN models were clearly found to be superior to the ESC models....

Synthesis, characterization and protein separation efficiency of N-isopropylacrylamide-co-N-tertiary butylacrylamide-co-acrylamide-based hydrogels

In the present study, hydrogels were prepared by free radical polymerization in water–dioxane mixture with fixed molar ratio (25 mol%) of N-isopropylacrylamide (NIPAM) and varying remaining molar concentrations of N-tert-butylacrylamide (NTBA) and acrylamide (AAm). The structure of the resultant hydrogels was studied by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) techniques. The thermal properties of the hydrogels were analyzed by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) methods. DSC thermograms were used for the quantitative determination of free, interfacial and bound water contents. The result showed that the free and interfacial water contents increased with increase in the hydrophilic AAm content, and the bound water content increased with hydrophobic NTBA content in the hydrogels. Swelling behavior of the hydrogels was evaluated at different temperatures. The percentage swelling and diffusion kinetic parameters (network structure constant, type of diffusion and diffusion constant) were calculated for all samples. The diffusion was found to be Fickian type for copolymer having equimolar concentrations of NTBA and AAm and non-Fickian type for others. Diffusion coefficients of the hydrogels were found to be increased with increasing temperature. In addition, poly(NIPAM-co-NTBA-co-AAm) hydrogels were used in concentration separation process for BSA solution. The result showed that the copolymer with equimolar NTBA and AAm contents has high separation efficiency with good thermoresponsive behavior among all copolymers.

Hypo-osmotic test in cat spermatozoa

The hypo-osmotic (HOS) test has been used in other species as an indicator of the fertilising capacity of spermatozoa. The aims of this study were to assess the response of domestic cat spermatozoa to the hypo-osmotic test, to determine the type of solution, concentration and time of incubation needed to obtain a maximum percentage of swelling, to correlate the selected combination with the percentages of progressive motility and to evaluate whether dilution of the ejaculate alters the results. Incubation for 30 and 45 min in solutions of fructose and of citrate of 50 and 100 mOsmol kg⁻¹ was evaluated. The highest percentage of swelling was obtained using the 50 mOsmol kg⁻¹ solution, and no significant differences were observed between the times of exposure to the solutions. A positive correlation was observed between the percentage of individual progressive motility and the percentage of sperm swelling in a 50 mOsmol kg⁻¹ fructose solution, with no significant differences being observed between raw and diluted semen samples. The results of this study suggest that the HOS test could be useful for evaluating membrane function in domestic cat spermatozoa, both in raw semen and in samples diluted in the EZ Mixin® commercial extender, and thus could be incorporated into routine semen evaluation protocols.

Efficacy of Platelet Rich Plasma and Hydroxyapatite Crystals in Bone Regeneration After Surgical Removal of Mandibular Third Molars

This study evaluates the efficacy of platelet rich plasma (PRP) & porous hydroxyapatite crystals in bone regeneration after surgical removal of mandibular third molar with the help of radiographs and its comparison with control side. A total of 40 patients; both male and female aged between 18 and 35years, who had impacted mandibular third molars were randomly selected for this study. Twenty patients were taken for control group and 20 patients for study group. The extraction socket of the study group was packed with PRP and hydroxyapatite granules and that of control group was sutured without PRP and hydroxyapatite. The bone density of both extraction sockets were evaluated radiographically using gray level histogram and compared periodically on immediate postoperative day, 1st and 3rd month postoperatively and postoperative sequelae of both the control group and study group in terms of oedema & pain or any other adverse reactions were also assessed. Data suggested evidence of early bone formation and maturation radiographically in study group as compared to control group. The percentage of facial swelling was numerically greater on the control side as compared to the study side, Pain was also assessed with VAS and it was found that the severity of pain was equal in both study and control groups and the results were not significant. This study clearly indicated a definitive improvement in the wound healing, increase in bone density, which signifies and highlights the use of PRP and hydroxyapatite granules, certainly as a valid method in inducing and accelerating bone regeneration.

CONTROL OF SWELLING OF SOIL UNDER CANAL LINING BY WETTING AND DRYING CYCLES

ABSTRACTIn the present research, the effects of cyclic wetting and drying on the swelling potential of clayey soils were investigated. For this purpose, three different clayey samples were collected from three irrigation project sites in Iran. The swelling tests were conducted in oedometer cells, where percent swell was measured in five wetting and drying cycles. To investigate the effects of initial moisture content of the soil on swell potential, the samples were tested at moisture contents at, below and above the shrinkage limit. The results of the experiments showed that for all samples, no matter at what the initial moisture content tested, swelling potential was considerably reduced as a result of the wetting and drying cycles. For some samples, maximum reduction in swelling was observed in the second cycle, while for others it occurred in the third or fourth cycle. Copyright © 2012 John Wiley & Sons, Ltd.

Uranyl ion uptake capacity of poly (N-isopropylacrylamide/maleic acid) copolymeric hydrogels prepared by gamma rays

The effect of gel composition, absorbed dose and pH of the solution on the uranyl ion uptake capacity of N-isopropylacrylamide/maleic acid copolymeric hydrogels containing 0–3mol% of maleic acid at 48kGy have been investigated. Uranyl uptake capacity of hydrogels are found to increase from 18.5 to 94.8mg [UO22+]/g dry gel as the mole % of maleic acid content in the gel structure increased from 0 to 3. The percent swelling, equilibrium swelling and diffusion coefficient values have been evaluated for poly(N-isopropylacrylamide/maleic acid) hydrogels at 500ppm of uranyl nitrate solution.

Effect of cross linking on the physicochemical properties of cola starch

Cola starch from Cola nitida (rubra) was isolated using 1% (w/v) sodium metabisulphite solution and was chemically modified with sodium tripolyphosphate (STPP) and acetic anhydride (ACOH) as cross-linking agents. The physicochemical and functional properties of the cross linked (modified starch) were compared with the native (unmodified) cola starch. The results presented important changes in the pasting, thermal transition and morphology of the native starch. The morphology of cross linked cola starch appears different from that of the native starch. The shape of the granules appears distorted and the general smoothness of the wall was replaced with some edges. Presence of slight aggregation of the starch granules was also observed. The physicochemical properties of the cross linked starch were obtained as follows: swelling 7.35 to 7.86% for ACOH, 6.00 t 6.20% for STPP, solubility 6.38 to 6.52% for ACOH and 6.23 to 6.48% for STPP, amylose (%): 23.88 for STPP and 24.58 for ACOH while the corresponding values for the native starch were, swelling: 8.85%. solubility: 7.48% and amylose: 24.76%. The results showed a decrease in percent swelling and solubility of cross linked starch compared to the native starch. Comparable values were obtained for both cross linking agents. The Rapid Visco Analyser (RVA) showed that both cross linking agents affected the peak, breakdown, set back and final viscosities of the native cola starch. The peak, breakdown, and set back viscosities of the cross-linked cola starch were lower than that of the native starch, while the final viscosity of the cola starch is lower than that of the cross linked starch. The extent of change is a function of temperature and heating times. The observed trends are consistent with other modified starches that have found useful applications in food and confectionery industries. Key words: Cross-linked (modified) starch, native starch, isolation, starch modification, physicochemical characteristics.

Recent Developments in the Swelling Model of Expansive Clays for Pavement-Heave Calculations

Abstract The prediction of pavement heave necessitates knowledge of the swelling-pressure characteristic (the swelling model) of the clay stratum under consideration, data that are usually obtained from laboratory tests on undisturbed clay specimens. It is demonstrated that a general swelling model equation should be employed that predicts the percentage of swell under a given vertical pressure exerted on clay characterized by the following parameters: (a) the liquid limit, (b) the ratio between the in situ moisture content and the plasticity limit, and (c) the in situ dry density. The development of this general equation is described by applying the Excel-solver analysis to 352 local test results, yielding preferable results to those stemming from a previous analysis that utilized the multiple linear regression method. Together with employing the general swelling model, an adjustment for any specific given condition is performed by conducting linear regressions (a simple one and a zero-intercept one) with the local test results and the general swelling model. Finally, the paper outlines guidelines for choosing the most relevant of the three calculated models.

Investigation of the influence of coal swelling on permeability characteristics using natural brown coal and reconstituted brown coal specimens

Permeability has been identified as one of the foremost factors that determine the effectiveness of CO2 sequestration in deep coalbeds. Coal matrix swelling can cause a remarkable decrease in the permeability of a coalbed reservoir during the carbon dioxide injection process. The main aim of this paper is to correlate the diametrical swelling percentage with coal permeability. This experimental program further attempts to investigate the effect of gas flow properties in coal due to CO2 sorption. Furthermore, the applicability of using a laboratory-made reconstituted coal specimen for permeability testing has been comprehensively investigated.A laboratory-based experimental program has been carried out using a high pressure triaxial experimental set-up. In this study, the effect of swelling on coal permeability has been investigated using two types of specimens. An intact brown coal specimen cored from a natural coal block and a reconstituted brown coal specimen made by compacting coal dust in a mould has been subjected to testing. Tests have been carried out under different gas injection and confining pressures. CO2 and N2 gases have been used as injection media. Gas injection has been carried out with two stages of N2 injection, prior to and after CO2 injection.Diametrical swelling of the two specimens has been compared with the permeability data. A good correlation was observed between permeability and coal swelling. The coal swelling percentage increased on exposure to carbon dioxide compared to exposure to N2. This effect increased as gas injection pressure increased. Exposure of the coal specimens to CO2 has contributed to a detrimental effect on permeability. This was clearly evident during the second injection of N2 gas.

On the swelling of polychloroprene‐MMT nanocomposite films

AbstractFor the first time, the effects on the percentage of swelling of fifteen solvents on latex polychloroprene (CR) nanocomposite (NC) films, and typical physical properties were studied. These films were prepared with 2.5, 5.0, 7.5, and 10.0 phr of montmorillonite (MMT) dispersed in water. Transmission electron microscopy (TEM) and X‐ray diffraction (XRD) results exhibit both exfoliated and intercalated layers in NC films. It was found that the Young's modulus and hardness increased with the MMT content. Calculations of the crosslink density were used to evaluate the effect of MMT concentration on the percentage of swelling. It was observed that in chloroform CR films showed the maximum swelling and it is therefore the best solvent to calculate the Flory–Huggins polymer–solvent interaction parameter as well as the crosslink density. To find the Flory‐Huggins polymer–solvent interaction parameter, it was preferred to use the Hoftyser and Van Krevelen polychloroprene solubility parameter of 19.2 (MPa)1/2 (calculated from the molar attraction constants) instead of using the swelling master curve which is not accurate. In all NC films, swelling by organic solvents was reduced by the addition of MMT. The increasing crosslink density with MMT suggests that dispersed clay emulates chemical bonds by hindering solvent migration throughout the polymer matrix and reducing solvent penetration. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Preparation and characterization of chitosan–zeolite composites

AbstractDouble crosslinked chitosan–zeolite (CZ‐2) and noncrosslinked chitosan–zeolite (CZ‐0) composites were prepared and characterized by using Fourier transform infrared (FTIR) spectrometer, surface area analyzer, scanning electron microscope coupled with energy dispersive X‐ray (SEM‐EDX) spectrometer, thermogravimetric analyzer (TGA), X‐ray diffraction analyzer (XRD) and carbon, hydrogen, nitrogen (CHN) analyzer. After crosslinking, CZ‐2 showed a reduction in surface area and CHN content in comparison to chitosan, zeolite, and CZ‐0. Crosslinking resulted in improved stability of CZ‐2 in distilled water, acetic acid and NaOH as CZ‐2 recorded the lowest percentage of swelling. XRD diffractograms confirmed the formation of composites as there was a marked difference in the peak intensity at 2θ = 19.8°. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Preparation and drug release properties of lignin–starch biodegradable films

AbstractStarch is one of the most commonly available natural polymers which are obtained from agro‐sources. It is renewable and abundant in nature. Unfortunately due to its poor mechanical properties and hygroscopic nature, there are some strong limitations to the development of starch‐based products. Usually blends of starch are prepared and plasticized with glycerol to improve some of its properties. In this study, lignin was extracted from hazelnut shells and investigated as a potential additive for starch biofilms. The structural characterization of hazelnut lignin was performed by employing UV spectroscopy and Fourier transform infrared (FTIR) spectroscopy. Lignin was blended with corn starch in different ratios to obtain biofilms. Mechanical and thermal properties of the biofilms were enhanced as the lignin amount was increased in the formulations. Water absorption tests were performed at pH 2.0, 4.0, and 6.0. The percent swelling values of the starch/lignin films increased as pH increased. Also, the biofilm exhibiting the best properties was chosen for the drug release studies. Biofilms showed a fast ciprofloxacin (CPF) release within an hour and then the drug release rate decreased. A pH dependent drug release mechanism was also observed according to Koshner–Peppas model. The drug release increased with a decrease in pH.

Design and evaluation of guar gum-based ofloxacin sustained release ocular insert

To prepare ocular inserts of ofloxacin using guar gum as a polymer for sustained delivery over a period of 24 h.Ofloxacin ocular inserts were prepared by the solvent casting method using guar gum in different proportions (0.5% w/v, 0.75% w/v and 1.0% w/v). The prepared formulations were evaluated for thickness, weight variation, percentage drug content, surface pH, folding endurance, percentage moisture absorption and loss, percentage swelling, mechanical strength and in vitro transcorneal permeation. In vitro transcorneal permeation study was performed on goat cornea using a modified Franz diffusion cell. The inserts were found to be of uniform thickness (ranging from 51.230 ± 0.385 μm to 109.275 ± 0.522 μm) and weight (1.720 ± 0.079 mg to 3.402 ± 0.105 mg). The % drug content in the inserts was found to vary between 95.450 ± 0.427% and 98.471 ± 0.225.The cumulative % drug releases from the formulation ranged from 38.19 to 75.21 over a period of 24 h. All the formulations followed a zero order release pattern. The in vitro transcorneal study revealed that an increase in concentration of the polymer slowed down the release of ofloxacin from the formulation.Ocular inserts using guar gum as a polymer were successfully prepared and can be effectively used for sustained ocular delivery over a period of 24 h.

Screening and RSM optimization for synthesis of a Gum tragacanth–acrylic acid based device for in situ controlled cetirizine dihydrochloride release

The present research work was aimed at the development and optimization of a Gum tragacanth–acrylic acid based hydrogel for in situ release of cetirizine dihydrochloride under different pH conditions such as 2.0, 7.0 and 9.2 at 37 °C. Various process variables like solvent, temperature, pH, treatment time, initiator molar ratio, concentration of monomer and cross-linker were screened using a fractional factorial design approach. Using a half normality plot, the most significant parameters for maximizing swelling are found. These significant parameters (solvent, pH and monomer) are further optimized using center composite design. The ANOVA model predicted that the interaction between pH and monomer concentration had an antagonistic effect on percentage swelling. The sequential experimental design approach was able to optimize the reaction parameters for getting the candidate polymer with maximum swelling capacity, thereby maximizing water absorption capacity by fivefold. Characterization of the candidate hydrogel Gt-cl-poly(AA) was done using FTIR and SEM techniques. The candidate polymer with maximum water absorption capacity was found to exhibit maximum drug absorption which later on was released in a Case II diffusion manner at pH 2.0 and 7.0. However, a non-Fickian mechanism was exhibited at pH 9.2. The hydrogel has been found to show colon specific release behavior of the drug. The initial diffusion coefficient has a greater value than the later diffusion coefficient indicating a higher drug release rate during the early stage.

Formulation and evaluation of chondroitin sulphate tablets of aceclofenac for colon targeted drug delivery.

The aim of the present study was to develop a single unit, site-specific matrix tablets of aceclofenac allowing targeted drug release in the colon with a microbially degradable polymeric carrier, chondroitin suphate (CS) and to coat the optimized batches with a pH dependent polymeric. The tablets were prepared by wet granulation method using starch mucilage as a binding agent and HPMC K-100 as a swellable polymer. Chondroitin Sulphate and drug and physical mixture were characterized by Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The tablets were tested for their in-vitro dissolution characteristics in various simulated gastric fluids for their suitability as a colon-specific drug delivery system and also the tablets were evaluated for physicochemical properties, drug content, water percentage swelling and erosion characteristics. The dissolution data demonstrates that the 10% w/w increase in coating level of the pH dependent polymer (Eudragit L-100 and Eudragit S-100 in a ratio of 1 : 4 prevented the drug release in the simulated gastric fluid (pH 1.2-SGF) and the simulated intestinal fluid (pH 7.4-SIF). The dissolution rate of the tablet is dependent upon the concentration of Chondroitin sulphate in the simulated colonic fluid (SCF). The rapid increase in release of aceclofenac in SCF was revealed as due to the degradation of the Chondroitin sulphate membrane by bacterial enzymes. The studies confirmed that, the designed system could be used potentially as a carrier for colon delivery of aceclofenac by regulating drug release in stomach and the small intestine.

Prediction of expansive soil swelling based on four micro-scale properties

A comprehensive study of expansive soil behavior includes understanding the surface phenomena of clay particles within the soil matrix. This research studies four micro-scale properties of four remolded expansive soils––matric suction, pH, surface conductance and percentage of montmorillonite––in order to predict soil swelling. An approach to approximate surface conductance is presented. Linear regression analyses were undertaken in an attempt to predict percent swell and swell pressure based on each of these micro-scale properties. Matric suction was found to be the most accurate predictor of the swelling behavior of the studied soils, which were initially compacted at optimum moisture content. Surface conductance, which is a combination of specific surface area, cation exchange capacity and cation mobility, also gave good predictions, except for one soil with high acidity.