Polyethylene Glycol Concentration Research Articles

Formulation optimization of chitosan nanoparticles incorporated rabies viral antigen and its influence on the release kinetics, immune potency and biosafety potential

In the present study, optimization of parameters for the preparation of nano formulated whole attenuated rabies vaccine with high immune potency and biocompatibility was synthesised. Response Surface Methodology (RSM) was adapted to study the influence of factors such as the concentration of chitosan (mg/mL), PEG (mg), acetic acid (%), sodium tripolyphosphate (M) and antigen (I.U.) on the structural, functional properties of chitosan PEG nanoparticles loaded rabies whole attenuated viral antigen (CS-PEG-NP-RVAg). Mathematical models were used to study the release kinetics of the nanoformulation adopting various plots such as Zero-order kinetics, First-order kinetics, Huguchi, and Huguchi-Crowell models. The evaluation provides insight into the controlled release of the rabies vaccine. The use of acetic acid (1%), sodium tripolyphosphate (0.1 M), antigen 1.5 (I.U.), PEG (60 µL), chitosan (75 mg) yields the desirable size of nanoformulations, immune potency, notable control release pattern Biocompatibility of the prepared nanovaccine was tested on Vero cell line, peripheral blood cells and probiotic bacterial strains. Nanoformulation, which obtained at the optimum condition was not inducing any toxic sign-on tested model system. Our study provides the basis of developing as effective CS-PEG-OV-RVAg as an effective and biocompatible vaccine formulation.

Cyclodextrin-linked PVP/PEG supramolecular hydrogels

Herein, we developed supramolecular hydrogels by using cyclodextrin (CD) molecules as crosslinking domains to hold poly(ethylene glycol) (PEG) and poly(N-vinylpyrrolidone) (PVP) chains in a network structure. The presence of PVP surrounding α-CD-PEG inclusion complexes through hydrogen bonds resulted in water-insoluble gels. Feed ratios of the reaction components and the molecular weight of the PEG chains were found considerably essential to adjust the properties of the final networks. With the increase of PEG concentration both the elastic and viscous modulus and the tensile capacity of the gels decreased. When the molecular weight of the PEG chains was used as ≥10 kDa, stable gels resistant to swelling forces were obtained. The synergistic effect of physical and chemical crosslinking by adding poly(ethylene glycol) dimethacrylate (PEGDMA) to the system was also investigated at varying concentrations resulted in stable networks with self-healing properties.

Mechanism of shales stabilization by hydrophobized poly(ethylene glycol)/K+ in water-base drilling fluids

The mechanism of the hydrophobized poly(ethylene glycol) (PEG)/K + system inhibiting shale hydration was studied by laboratory experiment. The inhibition performance was evaluated through cuttings hot-rolling dispersion, bentonite inhibition and contact angle tests. The inhibition became stronger as contact angle and PEG concentration increased. A modified cuttings hot-rolling dispersion experiment suggested that these molecular systems did not act through the thermally activated mud emulsion (TAME) mechanism. The interaction of the PEG/K + with clay samples was investigated through adsorption studies and by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The adsorption isotherms showed that the presence of K + increased the PEG affinity for the clay surface. This inhibition effect was accompanied by a reduction of the bentonite hydration with PEG adsorption, evidenced by FT-IR, TGA and differential thermogravimetric (DTG) curves. XRD patterns were conclusive in showing that the presence of K + ions limited the expansion of the clay interlamellar region to only one PEG layer, and the terminal hydrophobic segments of the PEG chains turned out to be determinant in enhancement of the inhibitory efficiency. The cuttings hot-rolling dispersion was carried out on water-base drilling fluid with PEG/K + , which proved the inhibition performance of PEG/K + in oil field drilling.

Effect of PEG-8000 imposed drought stress on rice varieties germination

Drought is the major abiotic stress factor that plays crucial role in reduction in plant production of agrycutural fields in the world. In order to evaluate drought stress on rice varieties germination, total 9 rice varieties were collected from varios place in West Sumatera. PEG-8000 is often used to determine tolerance and susceptible in germination level. Three different concentrations of PEG-8000 0%, 10 %, and 20% were used in the experiment. Germination percentage, shoot lenght, root lenght, root dry weight and shoot dry weight were determined as parameters studied. The result showed that rice varieties germination was significantly reduced with the increased of PEG concentration level in all parameters studied. Base on Drought Sensitively Index (DSI) we can classified the rice varieties as tolerant (Harum and Baroto), moderate (Situbagendit and Randam Kaus) and sensitive one (Keriting, Batang Palo, Kuning rendah, Indragiri, and Rosna putih).

Optimizing investigation of suspected allergy to polyethylene glycols

Polyethylene glycols (PEGs) are polymers of varying molecular weight (MW) used widely as excipients in drugs and other products, including the mRNA vaccines against coronavirus disease 2019. Allergy to PEGs is rare. Skin testing and graded challenge carries a high risk of inducing systemic reactions. We evaluated skin prick test (SPT) results and invitro reactivity over time to different MW PEGs and assessed cross-sensitization patterns in PEG allergy. Ten patients with previously diagnosed PEG allergy underwent SPT twice with PEGs 26 months apart. Lower MW (PEG 300, 3000, 6000) were tested, followed by PEG 20,000, in stepwise, increasing concentrations. Cross-sensitization to polysorbate 80 and poloxamer 407 was assessed. SPT was performed in 16 healthy controls. Invitro basophil histamine release (HR) test and passive sensitization HR test were performed in patients and controls. Patients previously testing positive on SPT to PEG 3000 and/or 6000 also tested positive to PEG 20,000. Patients with a longer interval since diagnosis tested negative to lower MW PEGs and positive mainly to higher concentrations of PEG 20,000. Three patients developed systemic urticaria during SPT. Eight patients showed cross-sensitization to poloxamer 407 and 3 to polysorbate 80. All controls tested negative. Invitro tests showed limited usefulness. Skin test reactivity to PEG can decrease over time, but titrated SPT with increasing concentrations of PEG 20,000 can be diagnostic when lower MW PEGs test negative. To avoid systemic reactions, stepwise SPT is mandatory.

Effect of PEG on structure and physical properties of PVA/CMC nanofiber

Nanofibers are a new class of material with unique features and a wide scope of uses. This research article studies the preparation of a novel polymer nanofiber composite from polyvinyl alcohol (PVA) (10%) blended with carboxymethyl cellulose (CMC) (2.5%) with different doses of Poly Ethylene Glycol (PEG) (0.25, 0.5, 0.75 g). Four different samples of PEG0, PEG1, PEG2 and PEG3 were prepared (6.25,7.5, 8.75 and 10 total % (w/v) respectively and The morphology and the average diameter of the electro spun fibers were observed using Scanning-electron microscopy (SEM). The SEM analysis was used also to help in optimizing the PEG concentration and the electrospinning condition (needle-to-collector distance, voltage, and flow rate), that can be used for the preparation of nanofiber membrane composed of PVA/CMC/PEG. The results showed that the nanofiber morphology and diameters of the nanofibers (PEG1, PEG2 and PEG3) were enhanced and the beads disappeared with increasing the PEG concentration and the optimum values for the electrospinning parameters to obtain PEG3 nanofibers with less average diameter are flow rate of 1ml/h, Voltage of 25 kV and Needle-to-collector distance of 25 cm with average diameter of electro spun nanofibers 362 nm. Also the thermal stability of the PVA/CMC/PEG (PEG3) nanofiber membrane was investigated by TGA. The results explained that the sample lost about 7 % at 115 C in the first stage, and lost 93 % after reaching 550 C as second stage of polymer degradation. The water contact angle (WCA) for PEG3 was measured to assess the water absorption and swelling properties of the membrane and the results showed the WCA was 45.35. This value was evidence that the membrane had hydrophilic properties. Treatment with cross linking is necessary if it will use in waste water applications.

Fabrication and characterizations of electrospun PAN/PEG1000/2000 composite fibres

Composite fibrous mats of polyacrylonitrile (PAN) and binary mixture of polyethylene glycol (PEG) 1000 plus PEG 2000 (1:1) have been fabricated using electrospinning. Phase change temperature range of PEG mixture is 24-33°C (cooling cycle) and 42-55°C (heating cycle), and corresponding enthalpy is 155J/g and 182J/g. The effects of PEG1000/2000 mass content on the morphology, thermal properties, structure of the produced composite fibres have been investigated thoroughly by scanning electron microscopy, differential scanning calorimetry, thermal gravimetric, fourier transform infrared spectroscopy and X-ray diffractometer. The experimental results show the preparation of three-dimensional nanofibrous mats. The fibre diameter varies with the PEG content. The latent heat enthalpy of the composite fibres increases with the increase in PEG blends content during cooling and heating cycles. Phase change temperature shows little difference between pure PEG and composite fibres. The obtained results also show that the super fine porous PAN mats can act as polymeric matrix of PEG1000/2000 and thus prevent the leakage of PEG1000/2000 during phase transition. PAN/PEG1000/2000 has potential to be a form-stable phase change material. polymeric matrix of PEG1000/2000 and thus prevent the leakage of PEG1000/2000 during phase transition. PAN/PEG1000/2000 has potential to be a form-stable phase change material.

Response of in vitro-regenerated Myrtus communis L. shoots to PEG-induced water stress

Myrtle ( Myrtus communis L.) is an evergreen and aromatic plant species with therapeutic and ornamental values . The effect of water stress induced by three concentrations of Polyethylene glycol (PEG), 0% (control), 3% (3%PEG) and 6% (6% PEG) was evaluated on in vitro -regenerated myrtle shoots. After 30 days of culture, all regeneration, growth and physiological parameters were measured at the end of the experiment. Murashige and Skoog (MS) medium contained 1.5 mgl -1 6-benzyladenine (BAP) and 0.2 mgl -1 Naphthaleneacetic acid (NAA) was optimized for the in vitro experiment. Increasing PEG concentration in the culture media resulted in fewer regenerated shoots, and higher rate of browning in the apical tissues. Chlorophylls and total carotenoids content significantly decreased in the shoots treated with PEG, however there were no significant differences in the pigment content under moderate or severe water stress conditions. PEG-induced water stress resulted in reduced plant growth and relative water content of newly-formed shoots. Lipid peroxidation and electrolyte leakage were lower in myrtle shoots treated with 6%PEG than 3%PEG, but they were still higher than that of the control. Proline accumulation significantly increased under 3%PEG treatment, while a little difference were observed between proline content under 6%PEG and the control. Apoptosis did not occur in the myrtle shoots grown under moderate or severe stress treatments which correlated with more increased Catalase and Superoxide dismutase activities in response to higher stress levels. The results showed a possible contribution of enzymatic antioxidant system in myrtle when counteracting severe water stress. • PEG-induced stress significantly decreased growth, water content, and pigments of in vitro -regenerated myrtle shoots. • Shoots showed a higher lipid peroxidation and electrolyte leakage under the PEG treatment than PEG-free control. • Proline accumulation significantly raised in myrtle only under mild water stress condition (3%PEG). • A higher increase of antioxidant enzymes might have a possible contribution in a lower apoptosis under stress condition.

Synthesis, Structural, Morphological and Thermal Characterization of Five Different Silica-Polyethylene Glycol-Chlorogenic Acid Hybrid Materials

The present study investigated the structure, morphology, thermal behavior, and bacterial growth analysis of novel three-component hybrid materials synthesized by the sol-gel method. The inorganic silica matrix was weakly bonded to the network of two organic components: a well-known polymer such as polyethylene glycol (PEG, average molar mass of about 4000 g/mol), and an antioxidant constituted by chlorogenic acid (CGA). In particular, a first series was made by a 50 wt% PEG-based (CGA-free) silica hybrid along with two 50 wt% PEG-based hybrids containing 10 and 20 wt% of CGA (denoted as SP50, SP50C10 and SP50C20, respectively). A second series contained a fixed amount of CGA (20 wt%) in silica-based hybrids: one was the PEG-free material (SC20) and the other two contained 12 and 50 wt% of PEG, respectively (SP12C20 and SP50C20, respectively), being the latter already included in the first series. The X-ray diffraction (XRD) patterns and scanning electron microscope (SEM) images of freshly prepared materials confirmed that all the materials were amorphous and homogeneous regardless of the content of PEG or CGA. The thermogravimetric (TG) analysis revealed a higher water content was adsorbed into the two component hybrids (SP50 and SC20) because of the availability of a larger number of H-bonds to be formed with water with respect to those of silica/PEG/CGA (SPC), where silica matrix was involved in these bonds with both organic components. Conversely, the PEG-rich materials (SP50C10 and SP50C20, both with 50 wt% of the polymer) retained a lower content of water. Decomposition of PEG and CGA occurred in almost the same temperature interval regardless of the content of each organic component. The antibacterial properties of the SiO2/PEG/CGA hybrid materials were studied in pellets using either Escherichia coli and Enterococcus faecalis, respectively. Excellent antibacterial activity was found against both bacteria regardless of the amount of polymer in the hybrids.

Physiological and morphological traits associated with germinative and reproductive stage of garden orache (A. hortensis L. var. rubra) under water stress

BackgroundDrought is a major problem limiting the growth and development of plants in the world and especially in Tunisia. Halophytes constitute a renewable wealth and they offer great flexibility with regard to abiotic stresses, and they are evaluated for their ecological and potential food use.ResultsThe proposed work identifies the response of Atriplex hortensis var. rubra to the germinal stage and the reproductive stage under a deficient water regime to measure the drought resistance of this plant that has very interesting forage production abilities. The morphological and water parameters are used to characterize the physiological response of this species to the effects of water deficit. For the germination test, four levels of osmotic potential caused by PEG-6000 solutions at different levels of water potential (− 0.1, − 0.5, − 1.0, − 1.5 MPa) were adopted in seed of A. hortensis germination media. The methodology adopted in the second experiment is based on the cultivation of potted plants stored in a semi-controlled greenhouse at flowering stage. The water deficit was imposed on the plants by watering stop for a week, and the control plants are subjected to a water regime maintained irrigated at 100% of the capacity in the field. Drought tolerance was scored 30 days after the drought stress commenced based on the number of branches and leaf, dry biomass, relative water content, leaf water potential, and nitrogen content. No significant difference was observed in germination rates for all PEG concentrations throughout the experiment which are still close to 60%. The results obtained for the second experiment show a high tolerance of A. hortensis under water stress. Drought induced decreases in two physiological parameters, the number of branches and leafs, and the relative water content of annual Atriplex. Heatmap and PCA data revealed that physiological parameters are more sensitive than morphological parameters in distinguishing the control and drought treatments.ConclusionsIndeed, the orache is distinguished by a great ability to retain water potential after a month of stress. Thus, height, number of branches, leaf and shoot dry weight, and percentage of nitrogen were significantly similar for controls and stressed for A. hortensis. On the other hand, measured root length and basic and midday water potential show significant variability between controls and stressors. In addition, these results highlight the importance of the resistance of Atriplex halophyte forage to drought.

Effect of pretreatment, temperature, gibberellin (GA3), salt and water stress on germination of Lavandula mairei Humbert

Lavandula mairei Humbert is an endemic species of Morocco, it is considered as rare and threatened species. It grows spontaneously in arid and semi-arid bioclimates, and found its uses in traditional medicine for the treatment of various diseases such as gastrointestinal diseases, microbial infection, cough and asthma. With the optic of conservation, this study aims to evaluate the combined effect of temperature and pretreatment on L. mairei seeds germination. On the other hand, this study looks to assess the effect of different concentrations of gibberellin (GA3), polyethylene glycol (PEG 6000) and sodium chloride (NaCl) on seeds germination. The results revealed, an optimal germination temperature of 25 °C, and over 90 % of seeds are able to germinate without using any pretreatment. Nevertheless, pretreatment of the seeds with sulfuric acid and hydrogen peroxide increased the germination rate to over 96 %. It has also been demonstrated that treatment with gibberellin improves the germination rate of L. mairei seeds. In addition, the water deficit caused a drop in the germination rate (of about 11 %) starting from - 0.53 MPa. Thus, the salt stress estimated by the application of different concentrations of sodium chloride (NaCl) has shown that the germination percentage of L. mairei seeds decreased considerably when the concentration exceeds 150 mM. This study could be a basic guide for the possible cultivation and conservation programs of L. mairei Humbert, Moroccan endemic and threatened plant.

In‐Silico Tuning of Curcumin Loading on PEG Grafted Chitosan: An Atomistic Simulation

AbstractIn this work, trimethyl chitosan grafted polyethylene glycol (PEG) was employed to optimize the curcumin loading, which is a natural bioactive substance with a good anti‐cancerous effect. It is vital to develop a novel carrier to increase the therapeutic effect of curcumin and decrease its hydrophobicity. Biocompatibility and hydrophilicity of the PEG cause it to be one of the most attractive drug carriers. Chitosan is also of great importance, considering its biocompatibility, and is used along with the drug‐carrying polymers. In this work, interaction energies, stability, hydrophilicity, and other molecular properties of the curcumin‐loaded PEG‐chitosan nanohybrid have been investigated. Atomistic analysis showd that the optimum concentration of chitosan is 60 % and optimum concentration of PEG is 40 %. In addition to concentration, the effect of PEG chain length, which is one of the important parameters of this circimin delivery system, has been also studied. The current work gives an atomistic insight into curcumin delivery and suggests a new curcumin delivery system.

Bioabsorbable flexible elastomer of PTMC‐b‐PEG‐b‐PTMC copolymer as intestinal anastomosis scaffold

AbstractArtificial intestinal devices play an important role for intestinal anastomosis, while there is not a suitable candidate with the characteristics for this application. It is necessary to develop a biodegradable tissue‐compliant intestinal anastomosis device. Herein, the triblock copolymers of poly(trimethylene carbonate)‐b‐polyethylene glycol‐b‐poly(trimethylene carbonate) (PTMC‐b‐PEG‐b‐PTMC) were prepared with different degradation properties by adjustable the block proportions. These copolymers were electrospun to fabricate the intestinal anastomosis scaffolds. Considering the degradation, mechanical properties, and hydrophilicity of the triblock copolymers, the scaffolds with PEG content ranging from 10% to 20% were suitable for implantation evaluation. The flexible scaffolds with PEG content of 15% were selected to perform animal experiments. The results showed that the scaffolds loaded with triclosan could effectively promote the healing of intestinal wounds and reduce the probability of intestinal fistula, intestinal obstruction, and other complications. The scaffolds are a promising candidate for clinical intestinal implants.

In vitro effect of polyethylene glycol and sorbitol on two banana varieties viz. Grand naine and Nalla bontha to study drought stress

Water stress is one of the foremost categories of stress damaging plants’ overall growth and development. The aim of the present study was to explore and demonstrate stress-induced drought to calibrate changes in stress parameters of two banana plant varieties viz. Grand naine (G9) and Nalla bontha were cultured in Murashige and Skoog medium (MS) media supplemented with stress inducers -Poly ethylene glycol (PEG) and sorbitol. The different concentrations of inducers were used to induce drought stress in two varieties of banana with contrasting characters for drought condition. The study indicated that PEG contrived mild to moderate osmotic stress and so does the alditol i.e. sorbitol on in vitro banana plants. The different concentrations of PEG and sorbitol produced significant effects on various parameters. The maximum decrease in shoot length was prominent in G9(52%) as compared to Nalla bontha (11%). When treated with 3% w/v sorbitol, even average root length showed the same level of damage with G9(59%) while in case of Nalla bontha there was a 17% decrease. The banana plantlet produced in vitro was estimated at one and two weeks after inoculation, respectively. Proline content tended to increase as the concentration of osmotic inducers increased (-44 % in G9 at 3% w/v sorbitol), whereas RWC (8.9% in G9 at 3% w/v Peg) showed an opposite effect. It was concluded that quantitative and qualitative changes in physiological (shoot and root length) and biochemical (Proline and relative water content, RWC) parameters played an important role in plants under drought stress conditions. This pattern varied from species to species. This work has been attempted for the first time in banana, especially Grand naine varieties with contrasting characters under induced drought stress.

Tunable temperature-responsive permeable composite films using polyethylene glycol as a phase change material

Poly(ether-block-amide) (PEBAX)/polyethylene glycol (PEG) (PEBAX/PEG) composite films were successfully prepared, via solution casting methods, for use as temperature-responsive permeable composite films. Their morphologies, thermal properties, and permeabilities were investigated as a function of PEG content. The introduction of high molecular weight PEG into PEBAX results in enhancement of thermal stability in the composite films. As the PEG content was increased, water vapor uptake increased, but the vapor diffusion rate decreased because of effects related to chemical affinity and crystallinity. All PEBAX/PEG composite films exhibited a jump in permeability at temperatures near the PEG phase transition temperature, and this depends on PEG content. This indicates that considerable gas passed through the composite films at temperatures near the PEG phase transition temperature, and this can be controlled by introducing different amounts of PEG. Our result can provide the insights into the further development of self-venting materials using temperature-responsive permeable materials for food, agricultural, and biomedical packaging.

Polyethylene glycol and silica sol penetration improves hydrophobicity and dimensional stability of wood after a short-time treatment

Polyethylene glycol (PEG) and silica sol were used to improve the dimension stability and hydrophobicity of wood with different moisture contents (MC after oven drying, air drying: 10–12% and steam conditioning: 38–40%) via 24 h immersion treatment. The water in wood served as a medium for helping PEG diffusion into cell wall, resulting in a better dimensional stability for 38–40% MC wood. PEG impregnation could improve the dimensional stability but decrease the surface hydrophobicity due to its moisture affinity. PEG concentration (10, 20, and 30 wt.%) showed little influence on water contact angles (WCA) of treated wood. Silica sol impregnation could improve the dimensional stability and WCA. It was ascribed to the -OH consumption and filling effect in wood caused by silica sol networks. After combination treatment (one-step or two-step method), PEG and silica sol could provide a synergistic effect on improving dimensional stability and hydrophobicity of wood owing to the bulking effect and filling effect, respectively. In one-step method, as a lubricant and bulking agent, PEG could improve the ductility of the film formed by stiff silica via Si–O–Si cross-linked sol in wood. Moreover, the decreased surface hardness and compression strength of PEG treated wood were compensated by silica incorporation.

Rapid One-Step Detection of Viral Particles Using an Aptamer-Based Thermophoretic Assay.

Rapid and sensitive identification of viral pathogens such as SARS-CoV-2 is a critical step to control the pandemic disease. Viral antigen detection can compete with gold-standard PCR-based nucleic acid diagnostics in terms of better reflection of viral infectivity and reduced risk of contamination from enzymatic amplification. Here, we report the development of a one-step thermophoretic assay using an aptamer and polyethylene glycol (PEG) for direct quantitative detection of viral particles. The assay relies on aptamer binding to the spike protein of SARS-CoV-2 and simultaneous accumulation of aptamer-bound viral particles in laser-induced gradients of temperature and PEG concentration. Using a pseudotyped lentivirus model, a limit of detection of ∼170 particles μL-1 (26 fM of the spike protein) is achieved in 15 min without the need of any pretreatment. As a proof of concept, the one-step thermophoretic assay is used to detect synthetic samples by spiking viral particles into oropharyngeal swabs with an accuracy of 100%. The simplicity, speed, and cost-effectiveness of this thermophoretic assay may expand the diagnostic tools for viral pathogens.

Improved permeate flux and rejection of ultrafiltration membranes prepared from polyethylene terephthalate (PET) bottle waste

The vast amount of not-recycled polyethylene terephthalate (PET) bottle waste is a serious threat to the environment. In order to utilize the waste, PET ultrafiltration membranes were prepared using PET bottle waste as the raw material by using the phase inversion technique. Low molecular weight polyethylene glycol (PEG 400) was used as the additive for the membranes. PET resin was also used as the membrane material to compare the properties of the membrane from PET bottle waste and those from the PET resin. The membrane prepared from PET bottle waste and that prepared from PET resin showed similar membrane characteristics such as IR spectra, morphology, hydrophilicity and porosity, indicating that instead of using PET resin, PET bottle waste can be utilized as a source of the polymer material to fabricate low-cost membranes. The morphology, hydrophilicity and porosity of the membranes were strongly affected by the PEG 400 concentration. The analysis of the membrane morphology using Scanning Electron Microscopy showed that the membranes had an asymmetric structure that consisted of a macroporous cross section and a smooth active layer. Increasing the PEG 400 concentration resulted in a smaller pore size, however the hydrophilicity and the porosity of the membranes increased. As a result, the membranes showed an increase in both permeate flux and rejection with increasing concentration of PEG 400 as observed from the results of the ultrafiltration experiments. Using Bovine Serum Albumin as a solute model in the feed, high values of rejection of up to 94% were achieved. Thus, ultrafiltration membranes with improved permeate flux and rejection could be prepared from PET bottle waste by the addition of PEG 400 as the additive.

Seed priming for increased seed germination and enhanced seedling vigor of winter rice

Low seed emergence rate, poor seedling growth and low survival rate of winter rice due to cold spell are very common in Bangladesh. Pre-sowing seed priming could be a viable approach to overcome this problem. A laboratory screening of different priming agents was conducted at the Agro Innovation Laboratory, Department of Agronomy, Bangladesh Agricultural University in November 2018. The experiment comprised two factors. Factor A includes five rice varieties, namely i) BRRI dhan28 ii) BRRI dhan29 iii) BRRI dhan36 iv) BRRI dhan55 and v) Hybrid SL-8H; factor B includes 22 seed priming methods comprised different concentrations of NaCl, KCl CaCl2, CuSO4, ZnSO4, Na2MoO4, PEG and control (no priming). The experiment was laid out in a completely randomized design (CRD) with four replications. A positive influence of seed priming on seed emergence rate (%), germination time, seedling vigor and seedling growth (length and dry matter) was evident from this study. Among the priming agents, KCl and CaCl2 performed best; while priming with NaCl, Na2MoO4 and PEG showed no advantages over no priming for germination rate and seedling vigor & growth indices. In conclusion, pre sowing seed priming approach can be explored as a viable tool for increased seed germination and better seedling growth of winter rice under stress condition.

Hydrogels applied in cosmetology irradiated by ionizing radiation

Hydrogels are three-dimensionally crosslinked polymers that exhibit high capacity to absorb water or solvents, without compromising its structure, allowing its application in cosmetic products, because it presents easy scattering and vehicular active principles. The use of ionizing radiation to obtain the hydrogels provides the absence of chemical initiators; sterilization; reticulation and adjustment of physical-chemical properties. In this work different types of hydrogels containing 5 wt%, 7.5 wt% and 10 wt% PVP concentrations and different radiation 25 and 20 kGy doses were prepared, maintaining 3 wt% PEG concentrations and 1 wt%, agar based on literature studies. The samples were characterized by dehydration as a function of time, acidity, visual and sensorial analyzes and stability. The results obtained showed that all the compositions are stable, have a pH close to the skin and the compositions containing 5 wt% PVP, obtained with 20 and 25 kGy radiation dose undergo greater dehydration. In sensory research, the hydrogels containing 7.5 wt% PVP, obtained with 25 kGy radiation dose, presented the best results in terms of absorption, sliding, odor, while the composition containing 10 wt% PVP obtained with 25 kGy radiation dose, proved to be inadequate in the public perception. Therefore, the hydrogels obtained with 7.5 wt% PVP, with 25 kGy radiation dose were the most suitable for applications in cosmetic products.