Hours In Water Research Articles

ВЛИЯНИЕ ФАКТОРОВ ПРОЦЕССА ПРОИЗВОДСТВА НА ПОКАЗАТЕЛИ ФАНЕРЫ НА МОДИФИЦИРОВАННОМ ФЕНОЛОФОРМАЛЬДЕГИДНОМ СВЯЗУЮЩЕМ

To reduce production costs, FSF plywood is produced by pressing at a reduced temperature. However, at the same time, the resite stage is not provided for the phenol-formaldehyde binder, which results in a decrease in the physical and mechanical properties of plywood. In the world and Russian practice of scientific work, this problem is solved in various ways: by modifying the binder at the stage of its synthesis, by preliminary surface treatment of veneer, by modifying phenol-formaldehyde binder at the stage of synthesis or “on site”. To develop a rational combination of the values of the production process factors, which makes it possible to form a more durable structure of plywood during low-temperature pressing, a modification of the binder with the addition of dimethylglyoxime was used. An experiment was carried out on the B-plan of the 2nd order. The following varied: proportion of dimethylglyoxime addition (from 0.5 to 1.5% of the binder mass), pressing temperature (from 110 to 130 ºС), pressing time (from 4 to 5 min). Regression models have been developed for the ultimate strength of plywood when chipping along the adhesive layer, ultimate strength in static bending, and thickness swelling of plywood after 24 hours in water. It was found that with an increase in the proportion of dimethylglyoxime additive to 1.5%, the shear strength of plywood increases by 25%, the static bending strength by 30%, and thickness swelling by 10%. This allows us to conclude about the deepening of the process of structure formation of FSF plywood when pressed on a modified binder. Recommendations for the rational combination of the values of the factors of the production process of FSF plywood have been developed

Effect of imbibition treatments on the germination of Stenocereus zopilotensis (Cactaceae) native from Guerrero, Mexico

The prickly pear cactus “tuna pelona” (Stenocereus zopilotensis), is an endemic cactus species from the state of Guerrero, Mexico, it develops in semi-arid areas and has great ecological importance as it houses and forms part of the diet of multiple species in its niche. There is a constant threat to natural populations of this species due to the overexploitation of seedling collections in the f ield by unregulated trade. In order to design an alternative for the conservation management of these species, the objective of the work was to evaluate treatments for the imbibition of “hairless tuna” seeds to promote germination and the successful establishment of seedlings with economic technologies for the farmers of the area. Fruits of "tuna pelona" (S. zopilotensis) were collected, near the community of Xalitla, municipality of Tepecoacuilco de Trujano, Guerrero; the seeds were stored for 70 and 273 days after collection (dac) at room temperature in order to maintain adequate conditions for the conservation of viability until reaching dormancy. In the stored seeds, the effect of soaking treatments was evaluated: 0, 6, 12, 24 and 12 hours in water plus another treatment that consisted of immersion in a plant-based hormonal stimulant. The germination percentage per treatment was evaluated, it was found that the control treatment (zero hours in water) of seeds stored at 70 dac only obtained 2.4% of germination. The treatment of soaking in water and in the hormonal stimulant both for 6 h presented the highest germination values with 48.6 and 44.4% respectively when using seeds of 273 dac at 14 days after the application of the treatments. These results will allow the massive production of seedlings of the species for reforestation and regional marketing purposes.

Evaluation Of The Effect Of Pre-Treatment Of Moringa Oleifera Lamarck (Moringaceae) Seeds At The Early Stage Of Germination For Massive Production In South Benin

Moringa Oleifera Lam., a tropical tree with multiple uses, used as a vegetable, is part of the eating habits of rural and urban communities. This study, which took place in the city of Cotonou, aims to contribute to a massive production of Moringa plants with a view to its promotion. In this line, an experimental protocol has been set down. Thus, four types of seed pretreatments were tested on a nursery whose plants are randomly arranged in four blocks of 30 plants with four repetitions. The treatments consisted of a control (seeds not pretreated) of seeds pre-heated to 50°C, seeds soaked for 48 hours in water and scarified seeds. The variables measured are the speed of germination, the height of the plants, the length of the stems and the number of leaves.. The results obtained show that the germination time is significantly better already from the 5th day after sowing for the heated seeds with a germination rate of 74.16%. As for scarified and soaked seeds, the germination rate is low 42.5%. However, at the development stage, the scarified seeds have a better stem height from the 50th day after sowing, a significant difference is observed between the controls (44,52); scarified (48.66) and seeds heated to 45 ° C (41.38) and a similar difference between controls (44.52) and soaked 48h (43.28). the same result is obtained for the length of the leaves from the 20th day after sowing or there is a significant difference (P = 0.0228) between the plants of the batches of scarified seeds and the seeds soaked for 48 hours and a similar difference between the soaked for 48 hours and the seedlings heated (6,17). On the other hand, the number of sheets parameter does not vary considerably depending on the pre-treatments. At the start of the experiment, a significant difference (P = 0.0011) was observed between the plants whose seeds were heated (3.43) and the soaked 48h (3.00) and the controls (2.57) and scarified (2.97). Decision makers must take steps to make Moringa Oleifera accessible to all populations through the creation of plantations for exploitation.

Regenerative ability of grape cuttings under the influence of yeast suspension treatment

The paper presents the growing experiment results on activating the regenerative ability of Moldova table variety grape cuttings by processing pressed baking yeast suspension. The present circumstance became the basis for conducting special studies to check cutting response to the treatment with baking yeast suspension, with the identification of drug optimal concentration. In spring, the two-eyed cuttings were completely soaked for 24 hours in water, and then they were placed with the basal ends in yeast suspension at various concentrations for the same time. Moreover, these yeast suspension concentrations were tested both in pure form and in combination with 3% sucrose. As a result of the conducted studies, it was revealed that pressed baking yeast suspension at certain concentration can have an activating effect on regenerative ability of grape cuttings. The use of yeast suspension together with sucrose solution increases their physiological activity. It was found that cuttings basal end soaking in yeast suspension at concentrations of 10-20 g/l, together with sucrose, contributed to rooting increased by 20-30%, the proportion of cuttings with three roots or more – by 22.5-30.0%, the number of roots by 13.5–16.2%. The best option was with a yeast suspension concentration of 20 g/l.

INFLUENCE OF THE LEVEL OF WATER MINERALIZATION ON THE CONCENTRATION OF HEAVY METALS IN MUSHROOMS

The current ecological condition of forest plantations has been characterized by high anthropogenic load as a result of population activity. The consequences of the human impact have been manifested in the disturbance of natural landscapes, air pollution, hydrosphere, destruction of the lithosphere, uncontrolled depletion of forest resources, resulting in a decrease and extinction of a huge number of species of animals and plants. In the result of various industries’ work chemical compounds have been formed, which have been transformed into the biosphere and enter all living organisms. Therefore, there are serious problems in the relationship between nature and man. The human impact on the environment is extremely powerful and it is obvious that the biosphere as a result of this impact loses the ability to self-regulate and it does not allow it to function properly. One of the current environmental problems that threatens plants, animals and human health and the quality of the environment is heavy metal pollution. These substances gradually enter plants, animals and humans through the air, water and food chain over a period of time [4]. Toxicity of metals has a direct effect on flora, which is an integral part of ecosystems. These effects lead to changes in the biochemical, physiological and metabolic processes that take place in plants that grow directly in areas with high levels of heavy metals. Samples of edible forest mushrooms were taken on the territory of forests of Tyvriv, Vinnytsia and Kalyniv districts in the Forest-Steppe of the Right Bank of Ukraine. Studies of the concentration of heavy metals were performed in the research and measurement agrochemical laboratory of the Department of Ecology and Environmental Protection, Faculty of Agronomy and Forestry on the basis of Vinnytsia National Agrarian University. The concentrations of Cu, Zn, Pb and Cd of the studied fungi were determined by atomic absorption spectrometry after dry mineralization. Studies of the effect of cooking on the concentration of heavy metals in mushrooms were carried out according to the following scheme: 1. control option: mushrooms, cleaned and washed with tap water; 2. option 1: mushrooms soaked for 3 hours in water without mineral residue; 3. mushrooms soaked for 3 hours in water without mineral residue with the addition of salt (1 kg of mushrooms – 1 liter of water and 10 g of salt). The effect of soaking mushrooms in water without mineral residue with the addition of salt was studied. It was found that when soaking mushrooms for 3 hours in water without mineral residue, the concentration of zinc in them decreased: from 1.02 to 1.37 times; copper - from 1.14 to 1.5 times; lead - from 1.09 to 1.13 times; cadmium - from 1.3 to 1.5 times. When soaking mushrooms for 3 hours in water without mineral residue with the addition of salt, the concentration of zinc in them decreased: from 1.23 to 1.28 times; copper - from 1.2 to 1.36 times; lead - from 1.31 to 1.38 times; cadmium - from 1.41 to 1.6 times.

Evaluation of the Transverse Strength and Elastic Modulus of High Impact Denture Base Material

Introduction: High fracture resistance of prostheses are well accepted by both patients and dentists to have a proper restoration of the dentition. The research designated assess polymerization time effect distinct and complete temperatures on mechanical properties (denture base resin) of a high strength. The research purpose is to assess and compare the procedure used in polymerization distinct effect autoclave on the elastic modulus and transverse strength of a high strength acrylic resin to the conventional heat polymerizing. Methods: Rectangular sample of ninety-one polymarised high heat strength denture base resin were created. Polymerized sample done by hot water regarded as control group and the other groups were polymerized in autoclave at different temperatures and time lenghts. After deflasking of sample before procedure it was kept forty eight hours in water. Three parameters were used when conducting transverse strength test bending using calibrated universal testing machine with a load of 500 kg cell and a crosshead speed of 5 mm/min. One-way ANOVA was used in assessing transverse strength and elastic modulus data. And for comparison of the groups application of Tukey HSD trial has been seen appropriate (p <0.05). Results: Specimens that polymerized by autoclave at 130oC for 20 and 30 minutes showed significantly better characteristics compared to the other groups. Conclusion: Upgrading of base resins transverse strength is required because the research indicated autoclave polymerization at 130°C for 20 and 30 minutes may be an alternative polymerization method.

First Report of Root and Crown Rot of American Ginseng Caused by Pythium spinosum in China.

American ginseng (Panax quinquefolius) is a perennial herb whose dried roots are used for health care products, medicine, and food in China (Yuan et al. 2010). Shandong Province is the main area growing American ginseng and contributes more than 50% of the production in China. Wendeng city, located in the east of Shandong Peninsula, is the primary production area of American ginseng in Shandong Province since it has four distinct seasons, sufficient light, loose soil (pH 5.5～7.0), and with thus a similar geographical environment and climate conditions to the American ginseng production area of the United States and Canada. In March 2016, 2-year old American ginseng plants that were planted directly into the ground in the greenhouses in Wendeng city, contained up to 6-10% stunted plants. Water-soaked lesions were observed on the crowns and the tips of fine roots. The leaves of the infected plants became scalded, dark green starting at the top of the plants and gradually move downward. Moreover, the leaves and petioles gradually curled withered and drooped, and the whole plant collapsed. Tissue samples, 10 mm in size, were excised from the water-soaked roots and crowns of diseased plants, rinsed under running water for 24 hours, dipped in a 0.2% calcium hypochlorite solution for 10 minutes, placed on sterile filter paper to dry and then placed on V8 medium (200 mL V8 Campbell Soup, 15 g agar, 0.2 g CaCO3, and 1 L distilled water) and incubated in the dark at 28 °C for 5 days. Five Pythium-like isolates which were arachnoid-cottony on cornmeal agar were isolated and they all produced hyphal swellings, oogonia, antheridia and oospores. Oospores were globose, smooth and plerotic, with some being aplerotic. The dimensions of hyphal swellings, oogonia and oospores respectively ranged from 9.0 to 21.3 (average 14.1) µm, 12.9 to 22.5 (average 18.2) µm, and 12.5 to 20.5 (average 16.7) µm. Finger-like projections were uniformly distributed on the walls of the oogonia and the antheridia were curved rods. The five Pythium-like isolates were identified as P. spinosum based on morphological characteristics (van der Plaats-Niterink, 1981). Genomic DNA was extracted from the isolates of the Pythium sp. using a DNA extraction kit (OMEGA, U.S.A.). The cytochrome c oxidase subunit I (COI) gene and internal transcribed spacer (ITS) region rDNA were amplified and sequenced using primers FM55/FM52R (Long et al. 2012) and ITS1/ITS4, respectively (White et al.1990). The five COI sequences were aligned and were identical for all five isolates, as well as the five ITS sequences. BLASTn analysis of the 538-bp COI sequence (accession no. MT822775) resulted in a 99% identity with that of the P. spinosum strain CBS122663 (accession no. HQ708832.1), and the 916-bp ITS sequence (accession no. MN847595) showed 100% identity with Genbank accession number AB217665 belonging to P. spinosum. Koch's postulates were confirmed. Corn kernels that had been soaked in water for 24 hours in water, autoclaved for 2 hours at 121˚C and allowed to cool were inoculated with agar plugs of P. spinosum grown on corn meal agar medium (CMA) for 10 days. The inoculated corn kernels were incubated at 28 ℃ for 13～15 days, until the corn kernels were covered with white hypha of P. spinosum. Ten healthy approximately 2-years old American ginseng plants growing in Wengdeng greenhouses were transplanted into a sterilized potting soil that was artificially infested with the corn inoculum (3 g inoculum per 100 g loam mixture). Inoculated and non-inoculated control plants were maintained in a greenhouse with a roof covered with sunshade net at 28 °C and 100% relative humidity. The experiment was repeated once. Four days after inoculation (DAI), the crown of inoculated plants developed water-soaked symptoms similar to those observed in field. No symptoms developed on the control plants. By 7 DAI, the inoculated fine roots and crowns showed water-soaked lesions identical to those observed in field, whereas control plants remained symptomless. The re-isolated isolate of P. spinosum was identical morphologically and by DNA sequence analysis to the original isolate. To our knowledge, this is the first report of root rot on American ginseng caused by P. spinosum in China and worldwide. Identification of the pathogen will assist in devising strategies to protect this important medicine plant from the pathogen, and to prevent yield losses.

Influence of different phosphoric acids before application of universal adhesive on the dental enamel.

There are different etching gels available, which have different composition, different pH, and different viscosity, and there is little information in the literature comparing all these products. To evaluate the mean microshear bond strength and morphological characteristics of tooth enamel by evaluating different phosphoric acids combined with a universal adhesive system. Eighty-four enamel samples were used, which were divided according to the acid conditioning: G1: Scotchbond Etchant (3M Oral Care), G2: Ultra-Etch (Ultradent), G3: Eco-Etch (IvoclarVivadent), G4: ETCH-37 with BAC (Bisco), G5: Etching gel (Densell), G6: Condac 37 (FGM), and G7: Scotchbond Universal Adhesive (3M Oral Care) in self-etch mode. For the adhesive procedure, Scotchbond Universal Adhesive was the one used as indicated the manufacturer's instructions, 0.9-mm-diameter resin cylinders were placed. The microshear bond strength test was performed after being stored for 24 hours in water. The morphological characteristics of tooth enamel were analyzed using the Raman confocal microscope alpha300RA. The analysis of variance (ANOVA) test and Tukey post-test were used to analyze the differences between the groups. The mean microshear bond strength values obtained for groups 1, 4, 5 were significantly greater than groups 2, 3, 6 and 7 (p < .05). All groups presented demineralization after the application of the etching acid, and few signs of demineralization were evident in group 7. Acid-etching with ETCH-37 with BAC, Etching gel, and Scotchbond Etchant improved the adhesive strength in the enamel using an universal adhesive, and acid-etching with Condac 37, Ultra-Etch, and Eco-Etch provides similar adhesive strength values to self-etch mode of universal adhesive. All acid etchants should be considered as different. The test confirms that enamel etching prior to the application of a universal adhesive system depends on the selected acid etchand product.

A new indicator for a fair comparison on the energy performance of data centers

The power usage effectiveness (PUE) is commonly used as the key performance indicator to evaluate the energy performance of data centers. However, using only PUE cannot enable a fair comparison when data centers are operating in different regions, due to the unneglectable impacts of climatic conditions on the power consumption of cooling systems. To solve this problem, a new indicator, coefficient of PUE (COPUE), is proposed, which is defined as the ratio of the measured PUE of real data centers to the local benchmark PUE. The benchmark PUE is reckoned based on the current most commonly used cooling technology, which consists of water-cooled chillers and water cooling towers. A simplified method for calculating benchmark PUE is also developed. The degree hour of water cooling is introduced to consider the impacts of local climatic conditions. It presents the annual accumulated hours, in which chilled water is needed to satisfy the cooling demand of data centers. Through several case studies, COPUE has been proved to be an effective indicator for comparing the energy performance of data centers. When the same cooling technology is adopted, it can reflect how good the design and operation are; while, when different cooling technologies are adopted, it can be used to demonstrate which one is superior.

Phase change material impregnated wood for passive thermal management of timber buildings

The Scots pine (Pinus sylvestris L.) sapwood was impregnated with the eutectic mixture of capric acid (CA) and stearic acid (SA) as phase change material (PCM) via vacuum process for passive thermoregulation in timber buildings. The hygroscopic properties, mechanical properties, thermal energy storage (TES) characteristics and lab-scale thermo-regulative performance of wood/CA-SA composite were evaluated. The produced composite from PCM was morphologically and physico-chemically characterized by SEM, FT-IR and XRD analysis. Thermal energy storage (TES) properties, cycling chemical/thermal reliability, and thermal degradation stability of the produced composite were determined by TG/DTA and DSC analysis. The hygroscopic tests revealed that the wood/CA-SA composite showed low water absorption (WA) and high anti-swelling efficiency (ASE) after 264 hours in water. Wood treatment with CA-SA increased the bending and compression strength of wood. TG/DTA data demonstrated that the wood/CA-SA composite left higher residue of 10.31% at 800°C than that of wood with 6.87%. The DSC measurements showed that the obtained wood/CA-SA composite had a good TES capacity of about 94 J/g at 23.94°C. The cycling DSC results confirmed the eutectic PCM in wood indicated high chemical stability and storage/release reliability even though it was run 600 times melt/freeze. According to thermal performance test, the wood/CA-SA composite has ability of storing excess heat in the environment and preventing the heat flow to the environment. It can be concluded that the fabricated wood/CA-SA composite can be used for indoor temperature regulation and energy saving in timber buildings.

Mechanical properties of aged yttria-stabilized tetragonal zirconia polycrystal after abrasion with different aluminum oxide particles

Statement of problemA consensus on the benefits of airborne-particle abrasion of zirconia with alumina particles of different sizes is still lacking. Larger particle size may improve micromechanical retention but may generate deep microcracks on the zirconia surface. PurposeThe purpose of this in vitro study was to evaluate the effect of different size of Al2O3 particles used for surface abrasion on the mechanical properties of yttria-stabilized tetragonal zirconia polycrystal (Y-TZP). Material and methodsSixty Y-TZP specimens were divided into 6 groups according to the treatment: control (without treatment) or airborne-particle abrasion with Al2O3 particles (45 μm or 150 μm). Half the specimens were stored for 24 hours in water while the other half was exposed to 1.5×106 mechanical cycles before flexural strength analysis at 1 mm/min crosshead speed. Specimens were also characterized by micro-Raman spectroscopy and X-ray diffraction (XRD) to evaluate the crystalline composition. The data were subjected to 2-way ANOVA and Tukey HSD test (α=.05). ResultsAirborne-particle abrasion with alumina (P=.030) and mechanical fatigue (P<.001) had a significant effect on flexural strength. Specimens abraded with 45-μm Al2O3 particles (847 ±204 MPa) presented higher flexural strength than those of the control group (670 ±210 MPa). The size of the alumina particles was not significant for flexural strength. Flexural resistance (664 MPa) significantly decreased after mechanical fatigue. All groups showed only the tetragonal phase on the micro-Raman spectra, which was confirmed by XRD. ConclusionsAirborne-particle abrasion with smaller Al2O3 particles increased the flexural strength on Y-TZP without causing phase transformation. However, flexural strength was decreased after mechanical fatigue.

Cyperus esculentus L. as a biotechnological raw material and substitute for peanuts in the production of confectionery products

A comparative chemical composition of peanuts and Cyperus esculentus – a raw material that does not contain gluten, rich in fat, vitamins and minerals, is given. The possibility of replacing crushed peanuts with alternative raw materials – Cyperus esculentus. nodules is considered. Appropriate preparation of raw materials is offered. Sprinkling shortcake dough with crushed Cyperus esculentus . nodules, pre-soaked for 12 hours in water, fried and crushed will increase the nutritional value of the product.

Reduksi Purin pada Emping Melinjo Melalui Pre-treatment Perendaman Emping Mentah

Melinjo chips (emping as local name) has high purine content which can be related to the high uric acid level in blood that lead to joint inflamation due to the sendimentation of uric acid. The objective of this research is to prove that soaking process can reduce purine content in emping and to know the effect of the soaking process length in purine reduction. Soaking time (2, 5, and 12 hours) and emping brand (Sriti, A1 and Koki) were used as the treatments. Purine compounds such as adenine and hypoxanthine were analyzed by using High Performance Liquid Chromatography (HPLC) method with C18 column and UV detector. The three emping samples were also analyzed by using sensory evaluation to know the consumer preference toward the treated fried emping. Results obtained from this research were that soaking process can reduce both adenine and hypoxanthin content in emping. Soaking for 2 hours in water could reduce adenine content 13 – 39% and hypoxanthine content 4 – 60%. Soaking process for 2 hours on emping could reduce up to 50% of total purine base content in A1 brand, however, soaking time was not directly proportional to the decrease in purine levels. Purine content after 5 and 12 hours soaking tend to be fluctuative. Emping samples that were soaked in the water have a decrease in preference by the panelists either in color, aroma, taste, texture or in overall, but still accepted by panelists.

Mechanical Characterization of Thermoplastic Aligner Materials: Recommendations for Test Parameter Standardization.

Background Understanding of the different mechanical properties of thermoplastic materials is essential for a successful aligner treatment and further developments. However, data of previous material testing studies are scarcely comparable. Aim of the current study was to evaluate the different test parameters to lay the foundations for guidelines for future, more standardized three-point-bending aligner material tests. Materials and Methods Several parameters concerning the specimen preparation and experimental three-point-bending setup were varied. The specimens were collected from polyethylene terephthalate glycol (PET-G) Duran® foils with different thicknesses. Both raw foils and foils thermoformed using different geometrical forms were investigated. The three-point-bending tests were performed using span lengths of 8 and 16 mm and variable deflection ranges between 0.1 and 0.2 mm. The influence of water storage on the bending forces was studied using unloaded and loaded specimens. Experimental results were validated using a beam cantilever mathematical model. Results Local macroscopic cracks after long-term loading could be avoided by keeping the deflections within a thickness-dependent individual range. The mathematical calculations confirmed that these individual deflection ranges lead to local stresses between 14 and 18 MPa. Constantly loaded specimens immersed for 24 hours in water showed a decrease of the bending force by 50%. This reduction was much smaller for the unloaded specimens (14%). Conclusion During clinical aligner therapy, very small bending deflections are combined with small distances between the tooth surface regions supporting the aligner. In vitro aligner material testing by three-point bending should consider these geometrical aspects, while keeping the material stresses in a range between 14 and 18 MPa to avoid local microcracks. Considering these aspects, thickness-dependent deflections were established for three-point bending of the PET-G specimen for a span length of 8 mm. We recommend the application of these test parameters in future aligner material studies to achieve valid and comparable test results.

Synthesis of Biodegradable Mixing-Polymer as Coating Material for Controlled-Release Urea Fertilizer

The biodegradable mixing-polymer as low cost, environmentally friendly coating material for controlled-release urea fertilizer was synthesized by borax crosslinked phosphated distarch phosphate (PDSP)/polyvinyl alcohol (PVA) and polyacrylic acid (PAA) via pan coating method. The physico-chemical characteristics of biodegradable mixing-polymer were confirmed by FTIR, TGA and SEM techniques. The kinetics of urea release were also carefully investigated in water and soil. It’s been found that a uniform layer with better bonding structure was created on surface of the mixing-polymer PDSP/PVA-PAA and the time released 70% urea reached 6 hours in water and more than 27 days in soil.

Acids ‘generally recognized as safe’ affect morphology and biocompatibility of electrospun chitosan/polyethylene oxide nanofibers

Electrospinning of neat chitosan is currently achieved by using strong acids or organic solvents, which limits the use of chitosan nanofibers as biocompatible scaffolds for drug delivery and tissue engineering. The aim was to elucidate the effect of specific acids generally recognized as safe (GRAS) on the properties of electrospun chitosan-based nanofibers. Electrospinning chitosan in dilute acetic acid or succinic acid with polyethylene oxide resulted in white and separated nanofibers, whereas nanofibers electrospun in dilute citric acid were transparent and interconnected. Including succinic or citric acid in the spinning process induced disintegration of the fiber mat after four hours in water, and a concentration-dependent effect on epithelial cell viability. Chitosan nanofibers electrospun in acetic acid maintained their shape and fibrous structure after four hours in water, and showed no effect on cell viability. This study demonstrates that the choice of GRAS acid highly determines the properties of electrospun chitosan nanofibers.

Influence of Low Temperature on Concrete Properties

The aim of this article is to show the negative effect of the reduced ripening temperature on the increase in compressive strength. Laboratory tests were performed on a concrete mix with a w/c ratio of 0.54. The samples were reformed for 2, 5, 8 hours at +18°C, and then were frozen once to -3°C and -8°C for 24 hours. After this time, the samples matured at +18°C. The greater the early strength, the lower the drop in compressive strength with a single freeze. The greatest decrease in strength was noted for concrete maturing 2 hours and once frozen to -8°C is 52.3%. The greatest impact on durability drops is: freezing temperature, pre-ripening time, type of cement used. Additionally, the methods of protecting concrete against the influence of negative temperatures are described. Laboratory tests carried out indicate a negative effect of the reduced temperature on the increase of compressive strength. The largest decrease in compressive strength in relation to the reference concrete was noted for concrete made of cement CEM II / BV 32.5R maturing for 2 hours in water at +18°C and once frozen in air to -8°C, a fall of 52.3 %. After analysing the test results, it was found that the drop in compression strength depends on the type of cement, the level of freezing temperature and the time of initial maturation. It was found that the lower the freezing temperature and the shorter the pre-ripening time, the greater the drop in compressive strength. The influence of negative temperatures on young concrete is harmful in every case, although this harmfulness has a different degree. It is therefore necessary to protect young concrete against this type of weather conditions. Concrete works under conditions of reduced temperatures are only possible if contractors take appropriate measures to enable binding and hardening of the concrete mix, e.g. by providing thermal protection, so that the young concrete in the element does not freeze. The reduced air temperatures have a negative effect on the setting and hardening of the concrete. The lower the ambient temperature of the concrete structure being made, the lower the concrete temperature and the younger the maturing process of the concrete is slower.

Dispersible hydrolytically sensitive nanoparticles for nasal delivery of thyrotropin releasing hormone (TRH)

Nose-to-brain delivery of drugs is affected by nanoparticles (NPs) deposited on the olfactory surface and absorbed directly into the brain. Thyrotropin releasing hormone (TRH), a water soluble drug used for treating suicidal patients, was incorporated into a fast degrading poly(sebacic anhydride) (PSA) NPs. NPs were prepared by a solvent-antisolvent process under strict anhydrous environment to obtain high TRH loading and to avoid premature PSA degradation and TRH release. PSA and TRH were dissolved in a mixture of dichloromethane and ethanol and added dropwise to a dispersion of mannitol particles in heptane as an antisolvent. Mannitol powder was included in the antisolvent, so that formed NPs adhered to the mannitol microparticles for easy isolation and immediate dispersion in water prior to use. The size, surface charge, and morphology of the TRH-PSA NPs were determined using dynamic light scattering (DLS), zeta-potential, and Scanning Electron Microscopy (SEM), respectively. The NPs prepared were uniform and spherical of ~250 nm. Further, the in vitro release profile of TRH from NPs lasted for 12 h with most TRH released within the first hour in water. Concentration dependent cell toxicity studies revealed low toxicity level at low concentrations of the NPs. Surface adsorption of the NPs was also uniform on the cell surface as examined through the odyssey near infrared fluorescence (NIR) images using Indocyanine green (ICG). The NPs are designed to enable direct delivery to the olfactory epithelium using a refillable nasal atomizer that deposits mist onto the olfactory neuro-epithelium.

Two enteral solutions with different chloride concentrations administered by naso-ruminal route for fluid therapy in adult cattle

ABSTRACT: Six adult Holstein cows were used in this fluid therapy study. All animals were previously submitted to 24 hours of water and food abstaining period and submitted to both hydration treatments for eight hours in a crossover design 6x2. Two treatments with hypotonic solutions (190 mOsm/L) with low strong ion difference and different chloride concentrations solutions were executed. Physical, biochemical, blood gas analysis and urinary evaluation were executed in five different experimental times (T-24h, T0h, T4h, T8h e T24h). The hydration period caused plasmatic volume expansion. An increase in faeces humidity, excretion of Na+ and Cl- in urine, reduction of PCV, osmolarity, blood and urinary pH was observed. Both solutions can be used for fluid therapy for adult cattle and solution containing calcium chloride (SECaCl) was the most suitable for use in animals with hypochloraemia.

Development of a whole plant bioassay to test effects of potentized calcium carbonate in pillule formulation

From a pharmaceutical point of view, we see a need to develop stable preclinical test systems to identify and investigate effects of potentized remedies as used in Anthroposophic Medicine and Homeopathy. We evaluated a plant bioassay regarding its capacity to distinguish homeopathic remedies from placebo, applied as sucrose pillules. Pea seed (Pisum sativum L) was soaked for 24 hours in water with dissolved homeopathic or placebo pillules, or in water only. Shoot length was measured 14 days after planting and treatment groups were compared by analysis of variance (ANOVA). The stability of the system was validated by systematic negative control experiments. The system is suitable to test a common application form - sucrose pillules - of a potentized preparation without influence of the pharmaceutical carrier substance. A screening of 13 potentized preparations revealed Calcium carbonicum to affect pea shoot growth (p < 0.05). Three independent series of main experiments were performed with potentized Calcium carbonicum to assess reproducibility. Meta-analysis of all data revealed significant effects of Calcium carbonicum 12c and 30c on pea shoot growth (p < 0.05), which were however dependent on the date of experiment and/or the experimental series. Potentized Calcium carbonicum, applied as sucrose pillules, influenced pea shoot growth in the assay investigated. However, due to the small effect size and due to the modulation of the effects by still unknown external factors, further optimization of this bioassay is necessary to be used in pharmaceutical quality control or in investigating the biological or pharmaceutical mode of action of potentized preparations.