Water-soluble Polyethylene Glycol Research Articles

Synthesis of Water-Soluble Polyethylene Glycol Fumarates for Biomedical Applications

Polyethylene glycol fumarate (PEGF) with controlled structural composition has been obtained for further synthesis of double network crosslinked hydrogels for biomedical applications. The copolymer has been synthesized by polycondensation reaction of fumaric acid and polyethylene glycol (PEG-600). Molecular weight of PEGF has been determined by gel permeation chromatography to be approximately 6000 Da with gel permeation chromatography. The polycondensation of fumaric acid and PEG-600 was studied throughout the reaction process. The structure of the reaction product has been evidenced using FTIR- and 1H NMR-spectroscopy. The quantitative ratios of the amount of –C=C– bonds and –COO groups to –C=O groups in the obtained PEGF have been estimated from IR-spectra for different synthesis time. The time-dependence of molar ratio of double bonds to methyl groups in PEGF has been obtained from corresponding 1H NMR-spectra. FTIR and 1H NMR-spectroscopy, both, demonstrate that after the end of reaction the unsaturated –C=C– double bonds remain in the structure of the macromonomer, that is essential for further preparation of cross-linked hydrogels. The addition of the tightly cross-linked network of polyvinyl alcohol leads to formation of highly tough biocompatible material for preparation of the artificial meniscus which can further be used as a solution n the treatment of diseases such as osteoarthritis.

Development of a protocol for standardized use of a water-soluble contrast agent with polyethylene glycol in post-mortem CT angiography

Computed tomography angiography (PMCTA) is increasingly used in postmortem cases. Standardized validated protocols permit to compare different PMCTA images and make it more easily to defend a case in court. In addition to the well-known technique by Grabherr et al. (2011) which is using paraffin oil as a carrier substance, water-soluble polyethylene glycol 200 (PEG200) can be used in combination with the contrast agent Accupaque® 300. As to date, there exists no standardized protocol for the use of this contrast agent mixture, the aim of this study was to develop a protocol using it. Between 2012 and 2022, 23 PMCTA with PEG200 and Accupaque®300 were performed at the University Centre of Legal Medicine Lausanne (Switzerland) and the Institute of Forensic Medicine Munich (Germany). The images obtained were evaluated regarding the opacification of the vessels and possible artefacts. The best image quality was obtained with a mixing ratio of 1:15 (Accupaque®300:PEG200) and a perfusion volume of 1000 ml in the arterial, 1400 ml in the venous and 350 ml in the dynamic phase. The infusion rates described by Grabherr et al. were confirmed for the three phases. Overall, the opacification of the vessels was diagnostically sufficient. In 13 cases no opacification of the right coronary artery was observed due to a stratification artefact. By using the PMCTA protocol with PEG200 as a carrier, a good overall image quality can be achieved. This protocol offers the possibility to standardize PMCTA with PEG200.

Phosphorus (V) 15-crown-5-phthalocyanine as a promising non-toxic near-IR photoinitiator in aqueous medium

The search for novel water soluble red and near-IR photoinitiators for biomedical applications is a very important task. Here we describe the synthesis and photophysical properties of a water soluble complex of P(V) with tetra-15-crown-5-phthalocyanine bearing diethylene glycol monoethyl ether as axial ligand (15C5PcP-gly). In addition to intense near-IR absorption, compound 15C5PcP-gly is characterized by a high quantum yield of singlet oxygen generation with moderate photostability. The combination of these properties with the discovered low dark and light induced cytotoxicity and negligible intracellular accumulation makes the complex 15C5PcP-gly promising for biophotopolymerization. Taking advantage of all the benefits of the 15C5PcP-gly complex, we demonstrate for the first time its successful application in the bulk photocuring of a water soluble polyethylene glycol diacrylate-based system with simultaneous preservation of mammalian cells viability.

Electrospun Materials Based on Cellulose Acetate Loaded with Rosmarinic Acid with Antioxidant and Antifungal Properties.

Fibrous cellulose acetate (CA) materials loaded with rosmarinic acid (RA) were successfully created by one-pot electrospinning. In order to improve the water solubility of the polyphenolic acid and to facilitate its release from the fibrous materials, the non-ionic water-soluble polyethylene glycol (PEG) was added. Detailed characterization of the fabricated fibrous CA/RA and CA/PEG/RA materials was performed using scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), UV-Vis spectroscopy and water contact angle analysis. The optimal ratio between CA, RA and PEG for preparation of defect-free and uniform fibers was accomplished by varying their concentrations. Furthermore, the incorporation of the PEG improved the hydrophilicity and wettability of the fibrous CA materials. Moreover, PEG facilitated the RA release and over 360 min, the amount released from fibrous CA/PEG/RA fibers was 91%, while that released from CA/RA materials was 53%. Both of the RA-containing fibrous materials, with and without PEG, manifested high antioxidant activity as determined by the DPPH free radical-scavenging method. In addition, the electrospun CA/PEG/RA materials displayed good antifungal activity against C. albicans. These features make the fibrous CA/PEG/RA materials promising candidates for treatment of wound infections.

Production of Ultrafine PVDF Nanofiber-/Nanonet-Based Air Filters via the Electroblowing Technique by Employing PEG as a Pore-Forming Agent.

Particles with diameters smaller than 2.5 μm (PM2.5) can penetrate the respiratory system and have negative impacts on human health. Filter media with a porous surface and nanofiber/nanonet structure demonstrate superior filtration performance compared to traditional nano- and microfiber-based filters. In this study, nanostructured filters were produced using the electroblowing method from solutions containing different ratios of poly(vinylidene fluoride) (PVDF) and polyethylene glycol (PEG) polymers for the first time. By increasing the water-soluble PEG ratio in PVDF/PEG blend nanofibers and employing a water bath treatment to the produced mat afterward, a more porous fibrous structure was obtained with a lower average fiber diameter. Notably, the removal of PEG from the PVDF/PEG (3-7) sample, which had the highest PEG content, exhibited clustered nanofiber-/nanonet-like structures with average diameters of 170 and 50 nm at the points where the fibers intersect. Although this process resulted in a slight decrease in the filtration efficiency (-1.3%), the significant reduction observed in pressure drop led to a 3.2% increase in the quality factor (QF). Additionally, by exploiting the polarizability of PVDF under an electric field, the filtration efficiency of the nanostructured PVDF filters enhanced with a ratio of 3.6% after corona discharge treatment leading to a 60% improvement in the QF. As a result, the PVDF/PEG (3-7) sample presented an impressive filtration efficiency of 99.57%, a pressure drop (ΔP) of 158 Pa, and a QF of 0.0345 Pa-1.

Influence of wood modification with polyethylene glycol and various carboxylic acids on the dimensional stability of beech wood (Fagus sylvatica)

ABSTRACT The goal of this study was the fixation of water-soluble polyethylene glycol (PEG) into the wooden cell wall. The dimensional stability of beech wood (Fagus sylvatica) modified with PEG400 and various carboxylic acids (1,2,3,4-butanetetracarboxylic acid (BTCA), citric acid (CA), malic acid, pyromellitic acid, tartaric acid, L-glutamic acid hydrochloride, ethylene diamine tetraacetic acid disodium salt dihydrate, trans-aconitic acid, maleic acid and itaconic acid) was examined. Investigations of anti-swelling efficiency (ASE), weight-percent gain (WPG) and bulking effect were made. Both the highest dimensional stabilization (values of ASE at the end of examination between 37 and 40%) and the best fixation of the chemicals in the wood (total loss of WPG between 37 and 38%) were achieved with combinations of BTCA/PEG and CA/PEG. The variants impregnated without PEG had lower bulking values. Successful modification of wood seems to be possible with BTCA, CA and malic acid in combination with PEG400.

Study of Strength and Stability of Concrete with Water-Soluble Polyethylene Glycol as Self-Curing Agent

Abstract: Curing plays a chief function in the growth of concrete properties throughout construction. Curing is often used to provide the method by which hydraulic cement concrete mature and increase hardened property more than time as a product of the constant hydration of the cement in the occurrence of enough water (ACI, 2008). The function of curing is to lessen water disappearance from concrete and keep acceptable moisture content, especially throughout early ages, for continuance of the hydration method that is essential for the growth of cement microstructure. Since we identify water shortage is mounting day by day, so an vital research should be needed to do the constructions without water. In early stages, water was mandatory for the curing purposes in construction. Curing of material do a chief job in rising pore structure and microstructure to increase durability and performance with water-soluble polyethylene glycol as self curing agent and light weight aggregate.

Photodynamic toluidine blue-gold nanoconjugates as a novel therapeutic for Staphylococcal biofilms.

Staphylococci are among the most frequent bacteria known to cause biofilm-related infections. Pathogenic biofilms represent a global healthcare challenge due to their high tolerance to antimicrobials. In this study, water soluble polyethylene glycol (PEG)-coated gold nanospheres (28 ppm) and nanostars (15 ppm) with electrostatically adsorbed photosensitizer (PS) Toluidine Blue O (TBO) ∼4 μM were successfully synthesized and characterized as PEG-GNPs@TBO and PEG-GNSs@TBO. Both nanoconjugates and the TBO 4 μM solution showed remarkable, if similar, antimicrobial photodynamic inactivation (aPDI) effects at 638 nm, inhibiting the formation of biofilms by two Staphylococcal strains: a clinical methicillin-resistant Staphylococcus aureus (MRSA) isolate and Staphylococcus epidermidis (S. epidermidis) RP62A. Alternatively in biofilm eradication treatments, the aPDI effects of PEG-GNSs@TBO were more effective and yielded a 75% and 50% reduction in viable count of MRSA and S. epidermidis RP62A preformed biofilms, respectively and when compared with untreated samples. This reduction in viable count was even greater than that obtained through aPDI treatment using a 40 μM TBO solution. Confocal laser microscopy (CLSM) and scanning electron microscope (SEM) images of PEG-GNSs@TBO's aPDI treatments revealed significant changes in the integrity and morphology of biofilms, with fewer colony masses. The generation of reactive oxygen species (ROS) upon PEG-GNSs@TBO's aPDI treatment was detected by CLSM using a specific ROS fluorescent probe, demonstrating bright fluorescence red spots across the surfaces of the treated biofilms. Our findings shine a light on the potential synergism between gold nanoparticles (AuNPs) and photosensitizers in developing novel nanoplatforms to target Staphylococcal biofilm related infections.

3D-printed surgical wound dressing for prolonged 5-fluorouracil delivery from pluronic blending composites

A direct drug delivery system of with the inhibition of multidrug resistance was developed in this study by the polymer mixing of Pluronic block copolymer F127, L121, polyethylene glycol (PEG), and polyvinyl alcohol (PVA). The polymer mixing was defined as Pluronic blending composites (PBCs) and optimized through adjusting the ratio of two different water-soluble homopolymers, PEG and PVA. The chemotherapeutic drugs of 5-fluorouracil (5-FU) were released from Pluronic blending composites nearly one month without continuous supplementary. Also, the effective ingredient of L121 inhibited multidrug resistance in human pancreatic cancer and caused the malfunction of the ATP binding cassette subfamily C (ABCC) transporter as evidenced by the flow cytometer studies. PBC-3 effectively suppresses the function of ABCC transporter up to 25 days. 5-FU are able to accumulate in the cancer cells of AsPC-1 and PANC-1 at a designated effective concentration. Then, a surgical dressing was prepared by 3D bio-printing technology with Pluronic blending composites cross-linked by sodium alginate. Results show that the surgical dressing of 24 layers with 10 mm × 10 mm would continuously release 5-FU in effective anticancer concentration for six days.

Polysaccharide-derivative coated intravascular catheters with superior multifunctional performance via simple and biocompatible method

• An intravascular catheter was coated with CMC layer exhibiting antimicrobial, antithrombotic, and low friction properties. • Whole manufacturing process was water-based, hence eco-friendly and biocompatible. • Functionalities of CMC layer were enhanced by engineering the porous structure. • Sufficient lubricity of porous CMC coated catheter was verified via trackability test. Antimicrobial, antithrombotic activity and low-friction functions are essential for the surface of intravascular catheters (ICs). However, the multifunctional surface, encompassing all of the above properties has not yet been realized. Here, we report a novel strategy for biocompatible and eco-friendly surface modification of the ICs with multifunctional polysaccharide, O-carboxymethyl chitosan (CMC). Micro- and nanoscale porous CMC (p-CMC) layer was simply fabricated via a selective elimination of the water-soluble polyethylene glycol (PEG) from heterogeneous CMC/PEG composite. The p-CMC structure exhibited a significantly enhanced hydration rate and superhydrophilic property. In particular, the antifouling property of superhydrophilic surface showed excellent anti-adhesion of Escherichia coli and platelets along with the intrinsic multifunctionality of CMC, indicating a dual effect of our p-CMC layer: (1) intrinsic antibacterial and antithrombotic properties of CMC and (2) anti-adhesion of substances on superhydrophilic surface. Meanwhile, despite the rough surface of the p-CMC layer, it showed high lubricity and durability under continuous wet friction conditions. Furthermore, we demonstrated that the actual p-CMC coated intravascular catheter (IC) provides superior trackability in a curved artificial blood vessel. The potential of the proposed coating strategy can be offered not only ICs, but also wide range of polymer-based applications including vascular filters, grafts, pacemakers and soft robots.

Gold Nanoprobes Exploring the Ice Structure in the Aqueous Dispersion of Poly(Ethylene Glycol)-Gold Hybrid Nanoparticles.

Ice structures and their formation process are fundamentally important to cryobiology, geoscience, and physical chemistry. In this work, we synthesized gold nanoprobes by grafting water-soluble polyethylene glycol (PEG) onto spherical gold nanoparticles and analyzed the structure of ice formation in the vicinity of the resulting hybrid PEG-Au nanoparticles (AuPEGNPs). Temperature-dependent in situ small-angle X-ray scattering (SAXS) indicated that AuPEGNPs, like PEG, caused the formation of bulk spherulite ice. Unlike for PEG, we observed the formation of lamellar ice with a periodicty of 4.6 nm, which is thermodynamically less stable than the bulk form. The lamellar ice formed after AuPEGNP agglomeration during cooling at -19 °C, and it remained during subsequent heating from -20 to -11 °C and melted at around -10 °C, far below the melting temperature of bulk ice. We explain different effects of AuPEGNP and free PEG on ice formation by the topological differences. The highly concentrated PEG chains on the agglomerated Au cores lead to the formation of PEG-hydrates that assemble into lamellar ice with a periodicity of 4.6 nm.

Experimental study on strength properties of self-curing concrete with fly ash and GGBS

Presently, Fly ash and GGBS were one of the widely using pozzolanic materials in construction industry. In recent years technique of using self-curing agents for internal curing for improving the strength of concrete has been developed. This investigation aims at the evaluation of mechanical properties of self-curing concrete with fly ash, with GGBS and water-soluble polyethylene glycol (PEG 400) as a self-curing agent with different percentages of 0, 0.5, and 1% with 20 and 30% of fly ash and 0, 40 and 60% of GGBS individually. The strength properties are investigated keeping concrete in ambient curing in the laboratory at a temperature of 27 °C. The experimental results have revealed by using 1.0% of the self-curing agent in concrete of 30% substitution of cement with fly ash. There is an increase of compressive strength was observed around 20 percentage in M25 grade, 11.95 percentage in M35 grade concrete, while the split tensile strength was increased from 2.8 to 6 N/mm2 for M25 grade the same for M35 grade it is increased from 4.2 to 7 N/mm2 compared to the conventional concrete.

In situ monitoring of photo-crosslinking reaction of water-soluble bifunctional macromers using magnetic levitation

Crosslinking is one of the fundamental phenomena in polymer science, which happens by forming covalent bonds or relatively short sequences of chemical bonds to join two polymer chains. Crosslinking and the subsequent volume shrinkage of monomers/macromers result in changes in their corresponding density which can be measured using density-based measurement techniques (e.g., dilatometry). Here, we demonstrate a method that allows in situ monitoring of photopolymerization of water-soluble bifunctional macromers using magnetic levitation (MagLev) system. We use a hydrophobic paramagnetic solution to monitor the photopolymerization of water-soluble polyethylene glycol diacrylate (PEGDA) as a model of bifunctional macromers using a ring MagLev system. Based on changes in levitation heights (densities) after illumination of blue light, we have successfully monitored the double bond conversion of PEGDA 700 macromers at various polymerization conditions. Our findings suggest that MagLev can be used as a new and complementary analytical technique for rapid screening of the photopolymerization reactions and measurement of conversions using changes in the levitation height of the macromers.

Development, Characterization and In Vivo Pharmacokinetic Assessment of Rectal Suppositories Containing Combination Antiretroviral Drugs for HIV Prevention.

Receptive anal intercourse (RAI) contributes significantly to HIV acquisition underscoring the need to develop HIV prevention options for populations engaging in RAI practices. We explored the feasibility of formulating rectal suppositories with potent antiviral drugs for on-demand use. A fixed-dose combination of tenofovir (TFV) and elvitegravir (EVG) (40 mg each) was co-formulated in six different suppository bases (three fat- and three water-soluble). Fat-soluble witepsol H15 and water-soluble polyethylene glycol (PEG) based suppositories demonstrated favorable in vitro release and were advanced to assess in vivo pharmacokinetics following rectal administration in macaques. In vivo drug release profiles were similar for both suppository bases. Median concentrations of TFV and EVG detected in rectal fluids at 2 h were 1- and 2-logs higher than the in vitro IC50, respectively; TFV-diphosphate levels in rectal tissues met or exceeded those associated with high efficacy against rectal simian HIV (SHIV) exposure in macaques. Leveraging on these findings, a PEG-based suppository with a lower dose combination of tenofovir alafenamide (TAF) and EVG (8 mg each) was developed and found to achieve similar rectal drug exposures in macaques. This study establishes the utility of rectal suppositories as a promising on-demand strategy for HIV PrEP and supports their clinical development.

Structural behavior of self-curing concrete with partial replacement of coarse aggregates with fly ash pellets

As we are in the world to conserve water for our daily needs, the present technologies have to be optimized in a feasible way, especially to one of the process curing in construction field. Thus, indeed there is an immediate need to do research on water used for curing process on concrete. Curing is one of the significant process for the concrete to have sufficient moisture content particularly at early stages of concreting in order to enhance the property of the concrete. It also plays a major role in concrete by developing pore structure and microstructure thus enhances its performance and durability. By considering these importance’s about curing and also to minimize the water for curing of concrete, a study has been conducted on concrete with the help of Polyethylene Glycol-400 (PEG-400) a water soluble self-curing agent to reduce the usage of water for curing. The present study also emphasis the use of fly ash pellets (FAP) prepared from the waste fly ash as coarse aggregate partially. The trail mix of concrete is proportioned replacing coarse aggregate by 10%, 15%, 20%, 25% and 30% with FAP and the compressive strength of the concrete were determined and found the optimum percentage replacement of coarse aggregate with FAP is at 25% resulting maximum compressive strength. The mechanical properties of concrete using water-soluble Polyethylene Glycol (PEG 400) have been found and also identified the optimum dosage to achieve maximum mechanical properties of the concrete. The increase in water retention capacity in the concrete and reducing the water evaporation in curing process can be done by using self-curing agent and it will absorb the water from the atmosphere thus saves water in the curing process compare to conventional concrete. The concrete mechanical properties containing self-curing agent are studied at various percentage such as 0.5, 0.7, 0.75, 0.8 and 1.0 added by weight of cement and compared with those of conventionally cured concrete. From the investigation it has been concluded that optimum dosage of PEG-400 for maximum mechanical property of M25 grade of concrete containing 25% of fly ash pellets as coarse aggregate is at the percentage of 0.75 by weight of cement.

A long-lasting biological larvicide against the dengue vector mosquito Aedes albopictus.

Aedes albopictus is the primary vector of mosquito-borne diseases, including dengue and chikungunya, in China. The management of vector mosquitoes is the primary strategy for the control of such infectious diseases. The gravid Ae. albopictus prefers to skip-oviposit its eggs into different small water containers, and the management of these breeding places is critical for mosquito control. Bacillus thuringiensis subspecies Israelensis (Bti) is a useful biological larvicide, but the effective period of the currently available commercial product is relatively short. This study aimed to develop a long-lasting formulation of Bti to control the dengue vector mosquito Ae. albopictus. Water-soluble polyethylene glycols and water-insoluble hexadecanol were mixed with Bti to develop the long-lasting formulation Bti-BLOCK, based on the solid dispersion technique. The controlled release of Bti-BLOCK and its effect on Ae. albopictus were assayed in the laboratory and in the field. The results showed that Bti toxins were slowly released from Bti-BLOCK into the water and maintained at an effective dose for at least 6 months. Bti-BLOCK caused high mortality during the immature stage (>90%) and achieved full inhibition during pupation (100%). The efficacy lasted at least 12 weeks in the laboratory and 6 weeks in the field. Furthermore, we confirmed an 89% reduction in Ae. albopictus density and a reduction in the R0 of dengue to a low-risk level after 6 months of open-field interventions. We developed a long-lasting biological larvicide, Bti-BLOCK, which displayed very good efficacy in the control of the dengue vector mosquito Ae. albopictus.

Comparison of the effect of polyethylene glycol and simultaneous administration of polyethylene glycol with probiotics in the treatment of chronic functional constipation: a clinical trial

Background and aims: Constipation is one of the most common issues in pediatrics. The aim of this study was to compare the effect of polyethylene glycol and the simultaneous administration of polyethylene glycol along with probiotics in the treatment of chronic functional constipation. Materials and Methods: In this randomized double-blind clinical trial, 150 children with chronic functional constipation referred to Imam Ali Clinic affiliated with Shahrekord University of Medical Sciences from 2017 to 2018 were included. The first group (A) consumed 1 g/ kg of body weight per day of water-soluble polyethylene glycol powder and the second group (B) consumed a probiotic powder and 1 g/kg of body weight of the water-soluble polyethylene glycol powder daily. In weeks 0, 1, and 2, questionnaires were filled out by the parents of the children and the data were analyzed. Results: The results showed that there was no significant difference in any of the variables between groups A and B (P=0.07) including the frequency of fecal excretion in week 1 (77% and 71%) and week 2 (4% and 5.4%) and stool consistency in week 1 (4% and 6.7%) and week 2 (86.7% and 92%). Moreover, there was no significant difference between groups A and B in any of the variables frequency of painful excretion in week 1 (74% and 73%, respectively) and week 2 (5.3% and 4%, respectively), frequency of abdominal pain in week 1 (61.3% and 49.3%, respectively) and week 2 (4% and 5.3%, respectively), and the frequency of fecal incontinence in week 1 (22.77% and 18.7%, respectively) and week 2 (6.7% and 1.3%) (P>0.05, respectively). Conclusion: Our results indicated that the administration of probiotic supplement (Lactobacillus Rhamnosus, Lactobacillus acidophilus, Lactobacillous Bulgaricus) has no effect on the improvement of symptoms in children with chronic constipation.

Biodegradable Polylactide Scaffolds with Pharmacological Activity by Means of Ultrasound Micromolding Technology

Ultrasound micromolding technology has been applied to get microporous polylactide scaffolds from the subsequent leaching of incorporated NaCl salts. A small amount of water-soluble polyethylene glycol (PEG) was required in order to improve the leaching process and get compact pieces with interconnected pores. Distribution of polymers in the processed specimens was quite homogeneous due to the small PEG content, although it was more concentrated in the regions close to the feeding channels due to its higher viscosity. Hydrophobic drugs like triclosan could be incorporated causing a minimum degradation during ultrasound processing and suffering an insignificant solubilization during the leaching step. Final scaffolds showed clear bactericide or bacteriostatic effects before and after 10 h of exposure. Cell proliferation of MDCK epithelial cells was higher for TCS loaded porous scaffolds (200%) than for unloaded samples (170%) and non-porous polylactide (PLA) specimens (100%, control). Micrographs showed the absence of non-inhibition areas in both the specimens and the container, confirming the biocompatibility of PLA specimens.

Covalently Tethered Rhodamine Voltage Reporters for High Speed Functional Imaging in Brain Tissue.

Voltage-sensitive fluorophores enable the direct visualization of membrane potential changes in living systems. To pair the speed and sensitivity of chemically synthesized fluorescent indicators with cell-type specific genetic methods, we here develop Rhodamine-based Voltage Reporters (RhoVR) that can be covalently tethered to genetically encoded, self-labeling enzymes. These chemical-genetic hybrids feature a photoinduced electron transfer triggered RhoVR voltage-sensitive indicator coupled to a chloroalkane HaloTag ligand through a long, water-soluble polyethylene glycol linker (RhoVR-Halo). When applied to cells, RhoVR-Halo dyes selectively and covalently bind to surface-expressed HaloTag enzyme on genetically modified cells. RhoVR-Halo dyes maintain high voltage sensitivities-up to 34% ΔF/F per 100 mV-and fast response times typical of untargeted RhoVRs, while gaining the selectivity of genetically encodable voltage indicators. We show that RhoVR-Halos can record action potentials in single trials from cultured rat hippocampal neurons and can be used in concert with green-fluorescent Ca2+ indicators like GCaMP to provide simultaneous voltage and Ca2+ imaging. In a brain slice, RhoVR-Halos provide exquisite labeling of defined cells and can be imaged using epifluorescence, confocal, or two-photon microscopy. Using high-speed epifluorescence microscopy, RhoVR-Halos provide a read-out of action potentials from labeled cortical neurons in a rat brain slice, without the need for trial averaging. These results demonstrate the potential of hybrid chemical-genetic voltage indicators to combine the optical performance of small-molecule chromophores with the inherent selectivity of genetically encodable systems, permitting imaging modalities inaccessible to either technique individually.

Effect of Polyethylene Glycol in Self-Curing of Self Compacting Concrete

The objective of this research is to evaluate the strength characteristics of self-compacting concrete as self-curing material by using water soluble Polyethylene Glycol 400. The objective of self-curing agent is to decrease concrete water disposal, thus increasing concrete's water retention ability in comparison with conventional curing. Self curing Concrete is a modern method, which performed to meet the water needs of the concrete without external curing. This research discusses the compressive, flexural, and split tensile strength of the concrete having the self-curing agent. Polyethylene glycol (PEG) of Molecular Weight 400 (PEG 400).The percentage of self-curing used from 0.5, 0.1, 1.5 and 2 percent by weight of cement. From the experimental results it is observed that optimal dosage PEG 400 is achieved at one percent being maximum strength. It is also found that the increase in PEG dosage decreases the strength of concrete.