Swelling Test Research Articles

Preparation and Enhancing Properties of pH‐Sensitive Hydrogel in Light of Gum Ghatti‐cl‐poly(acrylic acid)/ – o‐MWCNT for Sodium Diclofenac Drug Release

AbstractGum ghatti (GG) is used as a biopolymer, acrylic acid (AA) is used as a synthetic monomer, ammonium persulphate (APS) is used as an initiator, and methylene bis‐acrylamide (MBA) is used as a cross‐linker in the current study to create gum ghatti‐cl‐poly(acrylic acid)‐o‐MWCNT hydrogels. The –o‐MWCNT (0, 10, 20, 30, 40, and 50 mg) is added to the hydrogel as a filler. Fourier transform infrared (FTIR), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analyses are used to characterize the crosslinked hydrogels. The successful polymerization of the graft is confirmed by these spectroscopic studies. Sodium diclofenac (SD) as a model drug is utilized. Swelling tests are also conducted at pH 6.8 on all prepared hydrogels. In a similar manner, all hydrogel preparations are subjected to an in vitro study at neutral (pH 7.4), acidic (pH 1.2), and basic (pH 9.2) mediums, and a higher drug release is observed at pH 7.4. The Higuchi model, the Korsmeyer–Peppas model, and various zero‐order and first‐order kinetics are utilized in the investigation of the drug release order mechanism from the hydrogels. The drug release data favor the Korsmeyer–Peppas model, which describes the “n” diffusion exponent that controls the drug release mechanism from synthesized hydrogels. The “n” values control the Fickian diffusion (Case‐I diffusional) like coupled diffusion (0.45 ≤ n). According to the results presented here, GGAACNT‐based hydrogels can be used in biomedical fields, especially for controlled drug release.

Mammalian Chromosome Analysis and Sorting by Flow Cytometry.

The analysis of chromosomes by flow cytometry is termed flow cytogenetics, and it involves the analysis and sorting of single mitotic chromosomes in suspension. The study of flow karyograms provides insight into chromosome number and structure to provide information on chromosomal DNA content and can enable the detection of deletions, translocations, or any forms of aneuploidy. Beyond its clinical applications, flow cytogenetics greatly contributed to the Human Genome Project through the ability to sort pure populations of chromosomes for gene mapping, cloning, and the construction of DNA libraries. Maximizing the potential of these important applications of flow cytogenetics relies on precise instrument setup and optimal sample processing, both of which impact the accuracy and quality of the data that are generated. This article is a compilation of the existing protocols that describe the stepwise methodology of accumulating, isolating, and staining metaphase chromosomes to prepare single-chromosome suspensions for flow cytometric analysis and sorting. Although the chromosome preparation protocols have remained largely unchanged, cytometer technology has advanced dramatically since these protocols were originally developed. Advances in cytometry technologies offer new and exciting approaches for understanding and monitoring chromosomal aberrations, but the hallmark of these protocols remains their simplicity in methodologies and reagent requirements and the accuracy of data resolvable to every chromosome of the cell. © 2023 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Mitotic block and cell harvesting Basic Protocol 2: Propidium iodide isolation Support Protocol 1: Swelling test Basic Protocol 3: MgSO4 low-molecular-weight isolation Basic Protocol 4: Polyamine high-molecular-weight isolation Support Protocol 2: Molecular-weight determination of chromosomal DNA Basic Protocol 5: Chromosome analysis and sorting.

Effect of different concentrations of green tea on Cryopreservation of German Shepherd dog

To investigate the Effect of adding different concentrations of green tea extract as an antioxidant on specific physical semen characteristics of German Shepherd dogs during various steps of frozen semen processing this study was carried out. A total (of 20) good Ejaculate semen samples were collected in a plastic bag from German Shepherd dogs aged 3-4 yearsIn different locations (dog breeding).To achieve the current study's main objectives, two experiments were designed through periods extended from the beginning of December 2021 until the end of May 2022. The investigations included studying the physical properties of raw Semen (ejaculate volume, semen color, consistency, motility percentage, progressive motility percentage, dead sperm percentage, sperm abnormalities percentage, and hypo-osmotic swelling test (HOST). After that, semen samples were diluted with Tris supplemented with antioxidants. The physical properties of Semen were followed after cooling and after freezing (post-thawing). In the experiment, ten ejaculates were collected. Dilution of Semen was performed with Tris supplemented with two T1, T2, and T3) were cooled slowly up to 5C and equilibrated, packed into 0.5 ml straws, and put in vapor nitrogen (-196C) for 5-10 minutes after that, stored for 48and 72 hr in liquid Nitrogen (-196C). Progressive motility percentage, dead sperm percentage, sperm abnormalities percentage, and hypo-osmotic swelling test (HOST) were evaluated after cooling and post-thawing (Submerging the straws in the water bath at 37C for 30 seconds). It can be concluded from the present study that adding green tea extract as an antioxidant to the semen extender improves the ability to freeze, especially in the treatment T3 (0.01 mg/5 ml) and the T2 (0.05 mg/5 ml). This additive can decrease the negative Effect of freezing in liquid Nitrogen compared to the control group.

Design and characterization of adipose-derived mesenchymal stem cell loaded alginate/pullulan/hyaluronic acid hydrogel scaffold for wound healing applications

Recently, significant attention has been focused on the progression of skin equivalents to facilitate faster wound healing and thereby skin restoration. The main aim of this study was the design and characterization of a novel polysaccharide-based hydrogel scaffold by using alginate, pullulan, and hyaluronic acid polymers to provide an appropriate microenvironment to deliver Adipose-derived mesenchymal Stem Cells (ASC) in order to promote wound healing in an animal model. Characterization of synthesized hydrogel was done by using a field emission scanning electron microscope (FE-SEM), Fourier Transform-Infrared spectroscopy (FT-IR), and Differential Scanning Calorimetry (DSC). Also, contact angle analysis, the swelling and mechanical tests were performed. As a result of in vitro studies, cells can be attached, alive, and migrate through the prepared hydrogel scaffold. Finally, the therapeutic effect of the cell-seeded hydrogels was tested in the full-thickness animal wound model. Based on obtained results, the hydrogel-ASC treatment improved the healing process and accelerated wound closure.

Production and addition of encapsulated biomineralizing bacteria in construction concrete

The use of calcium carbonate for closing cracks in concrete by the action of biomineralizing bacteria has been investigated. However, these bacteria are fragile and susceptible to the reaction medium, and they must be protected by encapsulation, until the moment they must carry out the biomineralization process. This research covered the study and optimization of the production of sodium alginate capsules for subsequent encapsulation of biomineralizing bacteria. The research also investigated the effect of these capsules (added in different percentages) in concrete masses using a CP II – E Portland cement (ABNT NBR Standard), formulated from the Andreassen equation. The samples were characterized in their fresh and hardened state. The swelling tests indicated that the sodium alginate capsules provided good conditions to receive the bacteria, to keep them alive and to be mixed in the concrete, presenting enough mechanical strength. Among the investigated conditions, the composition formulated using the Andreassen coefficient equal to q=0.37 and with the addition of 1.5% of sodium alginate capsules was the one that presented the most promising results; and after 28 days of curing, the mechanical strength to compression was 45.4 MPa, with the value within ABNT NBR 11578, since it establishes a minimum of 32 MPa.

Evaluation of Hot Pressing Processing by Physical Properties of Ecofriendly Composites Reinforced by Eucalyptus Sawdust and Chamotte Residues.

The particleboard industry consumes large amounts of raw material, and this type of product consumption has been increasing over the last few years. The research for alternative raw materials becomes interesting, since most of the resources come from planted forests. In addition, the investigation of new raw materials must take into account environmentally correct solutions, such as the use of alternative natural fibers, use of agro-industrial residues, and resins of vegetable origin. The objective of this study was to evaluate the physical properties of panels manufactured by hot pressing using eucalyptus sawdust, chamotte, and polyurethane resin based on castor oil as raw materials. Eight formulations were designed with variations of 0, 5, 10, and 15% of chamotte, and two variations of resin with 10% and 15% of volumetric fraction. Tests of gravimetric density, X-ray densitometry, moisture content, water absorption, thickness swelling, and scanning electron microscopy were carried out. Through the results it can be noticed that the incorporation of chamotte in the manufacture of the panels increased the water absorption and the swelling in thickness, around 100% and the use of 15% of resin decreased, more than 50%, the values of these properties. X-ray densitometry analyzes showed that the addition of chamotte alters the density profile of the panel. In addition, the panels manufactured with 15% resin were classified as P7, the most demanding type on EN 312:2010 standard.

Wet-spinnability and crosslinked Fiber properties of alginate/hydroxyethyl cellulose with varied proportion for potential use in tendon tissue engineering

Researchers have examined different bio-inspired materials in tissue engineering and regenerative medicine to fabricate scaffolds to address tendon regeneration requirements. We developed fibers based on alginate (Alg) and hydroxyethyl cellulose (HEC) by wet-spinning technique to mimic the fibrous sheath of ECM. Various proportions (25:75, 50:50, 75:25) of 1 % Alg and 4 % HEC were blended to this aim. Two steps of crosslinking with different concentrations of CaCl2 (2.5 and 5 %) and glutaraldehyde (2.5 %) were used to improve physical and mechanical properties. The fibers were characterized by FTIR, SEM, swelling, degradation, and tensile tests. The in vitro proliferation, viability, and migration of tenocytes on the fibers were also evaluated. Moreover, the biocompatibility of implanted fibers was investigated in an animal model. The results showed ionic and covalent molecular interactions between the components. In addition, by properly maintaining surface morphology, fiber alignment, and swelling, lower concentrations of HEC in the blending provided good degradability and mechanical features. The mechanical strength of fibers was in the range of collagenous fibers. Increasing the crosslinking led to significantly different mechanical behaviors in terms of tensile strength and elongation at break. Because of good in vitro and in vivo biocompatibility, tenocyte proliferation, and migration, the biological macromolecular fibers could serve as desirable tendon substitutes. This study provides more practical insight into tendon tissue engineering in translational medicine.

Investigating the Performance of Co [AM-AMPS-MALEIC-AAC]/ PEI-MBA Nanocomposite Hydrogel in Sand Control from Oil Reservoirs

Sand production is one of the major challenges in oil and gas production from sandstone reservoirs. Production losses, formation damage, corrosion, and equipment failure are all consequences of sand production. Various mechanical and chemical methods are used to control sand production. One of the most efficient chemical methods is the injection of hydrogels, but its application has been constrained by the hydrogels' weak stability in the harsh conditions of the reservoir. A Co [AMAMPS-MALEIC-AAC]/PEI-MBA nanocomposite hydrogel with superior viscoelastic properties and double crosslinking was developed and synthesized to overcome these restrictions. Swelling, rheology, and morphology tests were utilized to predict the produced nanocomposite's effectiveness and performance in the harsh Iranian reservoirs. According to the obtained results, at ambient temperature (25°C, during injection) and reservoir temperature (90°C, placed in a porous medium), in distilled water, the maximum swelling ratio was 8.5 and 94, and in formation water, the maximum swelling ratio was 5.4 and 10.8, respectively. The X-ray diffraction test findings show that the nanoparticles are uniformly distributed throughout the structure. Also, according to the results of the thermal strength test, the sample’s thermal stability up to 90°C was confirmed with less than 0.6 wt% degradation. The results of the strain sweep, frequency sweep and stress-strain tests demonstrate the existence of a robust, three-dimensional, and viscoelastic structure up to a strain of 100% and a frequency of 100 Hz. In the strain sweep test with a constant frequency of 1 Hz, the maximum storage modulus was reported as 27,000 Pa, and in the frequency sweep test with a constant strain of 1%, 18,000 Pascals were reported. The stress-strain test revealed that the ultimate tensile strength of the synthesized material was 4630 pascals. These characteristics make the aforementioned nanocomposite hydrogel ideal for usage in porous media.

Density Gradient Centrifugation Alone or the Combination of DGC with Annexin V Magnetic-Activated Cell Sorting Prior to Cryopreservation Enhances the Postthaw Quality of Sperm from Infertile Male Patients with Poor Sperm Quality

Objective. To examine whether density gradient centrifugation (DGC) alone or its combination with annexin V magnetic-activated cell sorting (DGC-MACS) can be used to process semen samples from infertile male patients with poor sperm quality prior to subjecting these to freeze/thaw process in order to optimize the outcomes of sperm freezing. Methods. This study enrolled sixteen patients with sperm concentration ≥ 20 × 10 6 / mL , sperm motility < 30 %, and/or <4% normal sperm morphology. Sperms were processed by DGC or DGC-MACS prior to the freeze/thaw process. Sperm motility, hyperosmotic swelling test (HOS), TUNEL test, and morphological analysis were performed before and after the freeze/thaw process. Results. The freeze/thaw process had a detrimental effect on sperm motility, viability, morphology, and DNA integrity in all three groups (RAW, DGC, and DGC + MACS groups). The DGC and DGC + MACS groups showed increased sperm motility, viability, and normal morphology following freeze/thaw than untreated frozen controls. The motility and viability were not significantly different between DGC-MACS-CPT (cryopreservation-thawing) and DGC-CPT groups. Moreover, almost no grade A or grade B sperm was observed in the DGC-MACS-CPT groups. The sperm selected by DGC or DGC + MACS showed decreased levels of sperm DNA fragmentation than RAW samples following freeze/thaw. Moreover, the sperm DNA fragmentation following freeze/thaw in the DGC-MACS-CPT group was significantly lower than that in the DGC-CPT group. Conclusions. Sperm preparation by DGC before cryopreservation improved the quality of sperm postthaw in infertile males with poor sperm quality. If the sperm quality following freeze/thaw is foreseen to be insufficient for artificial insemination with husband’s sperm or in vitro fertilization, or if there is high DNA fragmentation in RAW sperm, DGC + MACS should be used prior to cryopreservation to reduce sperm DNA fragmentation and improve the quality of sperm available for intracytoplasmic sperm injection.

TITLE OF THE ARTICLE: EXOINTERACTIVE AMELIORATION AGAINST METHOTREXATE INTOXICATION IN MOUSE SPERMATOZOA

Objective: To assess the synergistic potential using an exointeractive association between Murraya koenigii hydromethanolic leaf extract and the synthetic compound quercetin to offset methotrexate induced toxicity in mouse cauda epididymal spermatozoa. Methods: Healthy adult male albino mice were divided into eight groups (N= 6/group) and were treated with methotrexate intraperitoneally (10mg/kg body weight) at intervals of every 48 hours for 15 days, to combat this toxic effects of the drug, Murraya koenigii hydromethanolic leaf extract (250mg/kg body weight) and quercetin (15mg and 30mg) alone as well as in combination, were given by oral administration. Various sperm parameters such as sperm count, motility and viability followed by Hypo-osmotic Swelling (HOS) test, apoptosis test, Sperm Toroid Integrity (STI) and Sperm Chromatin Dispersion (SCD) assay. Statistical analysis used: Statistical analysis was carried out using Graphpad Prism Version 7 to verify levels of significance at the P < 0.001 value in one-way ANOVA. Results: Methotrexate induced a substantial reduction in sperm count, motility and viability which induces apoptotic changes, also resulted in disruption of sperm toroid protamine-DNA binding, increased fragmentation of nuclear DNA by decreased sperm chromatin dispersion and low percentage of swollen sperm representing membrane integrity loss. whereas Murraya koenigii hydromethanolic leaf extract and quercetin proved effective in reversing the drug induced toxicity, especially with the 15 mg dose of quercetin along with the plant extract brought about significant amelioration than 30mg dose of quercetin due to its pro-oxidant effects. Conclusions: To reduce the toxic manifestations of methotrexate, this exointeractive approach proved efficient.

Synthesis of novel hydrophobic nanocomposite-modified silica as efficient shale inhibitor in fuel industry

Highly inhibitive and high-temperature-resistant shale inhibitors are required to be developed as water-based drilling fluids to accomplish the requirements of the drilling process. In this work, silica nanoparticles were grafted with hyperbranched APTMS and FOTS. The modified material and shale were analyzed by several characterizations such as scanning electron microscopy (SEM) equipped with energy dispersive X-ray (EDX), Fourier transform infrared (FTIR) spectroscopy, X-Ray diffractometer (XRD), thermal gravimetric analysis (TGA), and water contact angle (WCA) measurements. The experimental results revealed that the developed material displayed outstanding shale inhibition properties, such as inhibition in the hot rolling recovery test reaching ≈96% compared to 60.40% by KCl standard test. Moreover, the swelling test of Na-Bentonite (Na-Bt) was significantly determined in the presence of a nanocomposite inhibitor accounting for around 86% in comparison to KCl which is ≈56%. This result represented the high effectiveness of the developed material to prevent the expansion of water (hydrophobic property) into the original shale which is significantly greater than KCl commercial inhibitor. This study can be suggested the design of a permanent shale inhibitor for Water-based mud (WBM) in the larger drilling operation.

Dual responsive self-healing hydrogels with wide stability and excellent mechanical strength based on aliphatic polycarbonate

The wide development of hydrogels had been used in many filed due to the high water-containing and tough three-dimensional structure, however, the poor mechanical and multi-functional properties of hydrogel can be limited in its applications deeply. Herein, the dual responsive self-healing hydrogels with tough mechanical properties were manufactured by dual-physical cross-linking based on biodegradable aliphatic polycarbonate. Choosing the soft and hard segments to design the polymeric hydrogel not only can facilitate the dual-dynamic bonding interactions but also the resilient hydrogels possess robust and controllable mechanical strength (6.51 MPa). Furthermore, the results of swelling and stability tests of the materials indicated that the swelling ability of the biodegradable hydrogels can be regulated by the hydrophilic group, and the maximal swelling ratio in water and the equilibrium water content is 66% and 40%, respectively. It is worth mentioning that the tough hydrogels embrace dual-responsive high efficiency of self-healing ability, and the self-healing time is 2 h at 50 °C or 10 h under pH = 5, suggesting that the obtained hydrogels can respond to temperature and pH value to drive the fracture interface for fast self-healing, which will offer new opportunities for stimuli-responsive materials and wound healing.

Investigating the influence of water on swelling deformation and mechanical behavior of mudstone considering water softening effect

Mudstone not only swells and deforms but also be softened during water absorption because it contains many hydrophilic clay minerals. To study the influence of water on the swelling characteristics and mechanical behavior of mudstone, the water softening effect is first considered in the moisture diffusion-fracture coupling model based on the finite-discrete element method (FDEM). Then, the micro parameters of mudstone are calibrated by uniaxial, triaxial compression, and swelling tests. Subsequently, the coupling model is employed to perform uniaxial compression and triaxial compression numerical tests on the water-soaked mudstone. Results indicate that the mechanical strength decreases with the increase of water content, and the modeling results are consistent with the laboratory results. Besides, the failure pattern under uniaxial compression changes from shear failure to tensile failure as water content increases from 0% to 6%, while that of mudstone under triaxial compression tends to conjugate shear failure with the increase of water content and confining pressure. For all mudstones with different water content, the proportion of shear cracks increases with the increase of confining pressure. Finally, the effects of homogeneity index and swelling coefficient on the deformation, mechanical properties, and failure patterns of mudstone are discussed. The results in this paper provide a reference for understanding the mechanism of swelling characteristics and strength degradation of soft rock.

Histomorphological study in the pattern of thyroid lesions diagnosed by fine needle aspiration cytology

Background: Diseases of the thyroid gland is a common clinical presentation with a prevalence rate of 4-7% in the general population. The presence of thyroid swelling can cause concern to both patient and surgeon as for the diagnosis and treatment is concerned. The current study aims to study the histomorphological pattern of various thyroid lesions. Methods: A prospective cross sectional study was carried out in Bapuji Hospital and Chigateri district hospital, teaching hospitals attached to J.J.M. Medical College Davanagere over a year from August 2020 to June 2022. All patients with clinical evidence of thyroid swelling were selected. Ultrasonography (USG), fine needle aspiration of thyroid swelling (FNAC) and thyroid function test (TFT) was done and histomorphological pattern of each patient was studied. Results: The reports of FNAC and USG were similar in most of the patients. Accordingly, accuracy is 100%, sensitivity 90%, specificity 0%, positive predictive value 90%, negative predictive value 0%. Conclusions: As per the study accuracy of FNAC with USG is 100%. USG neck will help to diagnose the solid and cystic lesions. FNAC is a good diagnostic tool in the diagnosis of neoplasm and thyroiditis, Bethesda categorization helps the surgeon to plan for surgery based on the reports and thyroid profile. USG and FNAC are equally sensitive in diagnosing malignancy, but FNAC is more specific (90%). It is a minimally invasive method which can be used to distinguish malignant from benign lesions with a high degree of accuracy (90%).

Investigation of the structure, filler interaction and degradation of disulfide elastomers made by Reversible Radical Recombination Polymerization (R3P)

In this paper we report the synthesis and analysis of cyclic polydisulfides, their redox depolymerization as well as their interaction with carbon black. Cyclic poly(3,6-dioxa-1,8-octanedithiol)s (pDODT) were synthesized by Reversible Radical Recombination Polymerization (R3P). R3P is a scalable “green” polymerization process using triethylamine (TEA), H2O2 and air for the polymerization of dithiol monomers. pDODTs were synthesized in 5 and 20 g batches. The effect of peroxide concentration (3, 5, 10, 20, 30 %) was investigated. It was found that the molecular weights increased exponentially with increasing peroxide concentrations. At 30 % peroxide concentration pDODTs with Mn up to 400,000 g/mol and polydispersity of 2 were obtained. 700 and 800 MHz NMR were used for investigating the chemical structure of the polymers. The absence of thiol end group signals in polymers made with > 10 wt % H2O2 and Mn < 100,000 g/mol, including a sample of a fractionated polymer with starting Mn = 600,000 g/mol, verified cyclic structures. Dithiothreitol reduced the polymers to monomer and a small percentage of oligomers. Carbon black was shown to increase the moduli of high molecular weight pDODTs. Swelling tests in chloroform showed that polymers made with 20 and 30 w% peroxide swelled 14 and 10 times of their starting weight without dissolving, indicating chemical interaction between the polymers and carbon black. Further analysis of these interesting elastomers, available at the 20 g scale, is in progress.

Alginate-Gelatin Self-Healing Hydrogel Produced via Static-Dynamic Crosslinking.

Alginate-gelatin hydrogels mimicking extracellular matrix (ECM) of soft tissues have been generated by static-dynamic double crosslinking, allowing fine control over the physical and chemical properties. Dynamic crosslinking provides self-healing and injectability attributes to the hydrogel and promotes cell migration and proliferation, while the static network improves stability. The static crosslinking was performed by enzymatic coupling of the tyrosine residues of gelatin with tyramine residues inserted in the alginate backbone, catalyzed by horseradish peroxidase (HRP). The dynamic crosslinking was obtained by functionalizing alginate with 3-aminophenylboronic acid which generates a reversible bond with the vicinal hydroxyl groups of the alginate chains. Varying the ratio of alginate and gelatin, hydrogels with different properties were obtained, and the most suitable for 3D soft tissue model development with a 2.5:1 alginate:gelatin molar ratio was selected. The selected hydrogel was characterized with a swelling test, rheology test, self-healing test and by cytotoxicity, and the formulation resulted in transparent, reproducible, varying biomaterial batch, with a fast gelation time and cell biocompatibility. It is able to modulate the loss of the inner structure stability for a longer time with respect to the formulation made with only covalent enzymatic crosslinking, and shows self-healing properties.

Establishment of methods to analyze the structural and functional integrity of the quail (Coturnix coturnix japonica) sperm plasma membrane

ABSTRACT 1. The objectives of this study were to establish the use of the fluorophores Hoechst 33342 and propidium iodide for the evaluation of sperm plasma membrane integrity and to identify an adequate hypoosmotic solution for the evaluation of sperm membrane functionality in quails. 2. Sperm samples were collected from the vas deferens of nine quails. After initial evaluation, the samples were subjected to a flash-frozen assay. Three treatments with the following proportions of fresh sperm and sperm subjected to flash freezing were prepared as follows: 100:0 (T100), 50:50 (T50), and 0:100 (T0). The hypoosmotic swelling test used distilled water (0 mOsm/l) and fructose solutions (50, 100, and 200 mOsm/l). 3. Immediately after recovery, the samples showed 75.6 ± 5.0% motility with vigour of 3.7 ± 0.3 and 96.1 ± 0.5% of the sperm appeared normal. The membrane integrity test showed 62.2 ± 5.2% intact sperm at T100, 29.0 ± 4.1% at T50 and 0.1 ± 0.1% at T0. Moreover, a greater number of reactive sperm (74.7 ± 6.7%) were observed when incubated in distilled water (0 mOsm/l) in comparison to other solutions (P < 0.05). 4. The association of fluorescent probes composed of Hoechst 33342 and propidium iodide provided an efficient assessment of the integrity of the plasmatic membrane of quail spermatozoa. However, the study identified that the hypoosmotic swelling test has little predictive value regarding sperm membrane functionality in this species.

Optimisation of the preparation procedure of crumb rubber modified bitumen with wax-based additives

Wax-based additives can be added to crumb rubber modified bitumen (CRMB) at different stages to enhance the workability. This study aims to optimize the preparation procedure by investigating the effects of the preparation procedure on the rheological properties of CRMB containing wax-based additives and the interaction mechanism. Rubber swelling tests under various conditions were conducted to examine the effects of temperature and additives on the interaction process. Rheological and thermal characterizations were performed on the CRMB binder and its liquid phase. Results show that reducing the bitumen viscosity by adding wax-based additives can promote the bitumen-rubber interaction and achieve similar swelling results at a lower temperature. However, a significant proportion of wax-based additives were found to penetrate rubber particles for the warm-produced CRMB. Although warm-produced CRMB may save energies compared to hot-produced CRMB, it is not recommended to replace the traditional hot-produced CRMB procedure.

Serotypes and Antibiotic Resistance of Streptococcus pneumoniae before and after the Introduction of the 13-Valent Pneumococcal Conjugate Vaccine for Adults and Children in a Rural Area in Japan.

The increase in non-vaccine serotypes of Streptococcus pneumoniae and their multidrug resistance have become an issue following the introduction of the 13-valent pneumococcal conjugate vaccine (PCV13). In this study, we investigated the serotypes and drug resistance of S. pneumoniae detected in adult and pediatric outpatients at a hospital in a rural area of Japan between April 2012 and December 2016. Serotypes of the bacterium were identified using the capsular swelling test and multiplex polymerase chain reaction testing of DNA extracted from the specimens. Antimicrobial susceptibility was determined using the broth microdilution method. The serotype 15A was classified using multilocus sequence typing. The results showed that the prevalence of non-vaccine serotypes increased significantly in children from 50.0% in 2012-2013 to 74.1% in 2016 (p ≤ 0.006) and in adults from 15.8% in 2012-2013 to 61.5% in 2016 (p ≤ 0.026), but no increase in drug-resistant isolates was evident. However, an increase in the drug-resistant serotypes 15A and 35B was observed in children. Although isolates of these two serotypes showed cefotaxime susceptibility, cefotaxime resistance was confirmed for the serotype 15A isolates. Future trends in the spread of these isolates should be monitored with caution.

Experimental Investigation on the Performance of Polymer-Coated Clay/Polyacrylamide Hydrogel for Water Shutoff Treatment

SummaryPolymer gel system has been identified as having the potential for blocking and diverting water flow. However, the current polymer reported an inability to maintain its mechanical strength, limited penetration depth, and instability in reservoir conditions of high temperature and high pressure. A distinctive bentonite nanomer clay (PGV)/acrylamide (AM)-co-2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) preformed particle gel with poly(ethylene glycol-b-tetramethylene oxide) (PEGTMO) coating to control the swelling kinetics is formulated. The in-house formulated gel’s ability to block and divert water flow in a porous medium is studied. The formation recipe of the gel was achieved by numerous swelling tests as induced by brine solution under reservoir conditions. Through the swelling tests, the long-term thermal stability of the gel solution was demonstrated. The incorporation of PGV clay particles improves the swelling and mechanical properties of the gel. Premature swelling can be avoided with PEGTMO coating as it slows the swelling rate over a 10-minute period, which gives the advantage of controlling the swelling before reaching the intended site of action during coreflood experiments. The rheological behavior of the hydrogel features rubber-like mechanical behavior with a viscosity value of 1.17 cp, which displayed water-like characteristics. Further, significant permeability reduction of large fractures is demonstrated by the coreflooding experiment with a calculated result of 96.2%. This formulated gel could offer the solution as a blocking agent in void space channels containing reservoirs that leads to a reduction of water cut due to thief zones.