Hydration Treatments Research Articles

Reattachment of rehydrated dental fragment using two techniques

The reattachment of dental fragments is a conservative treatment and should be considered in the restoration of anterior tooth fractures. This study compared the fracture strength of dehydrated and rehydrated tooth fragments submitted to two different bonding techniques. Sixty human central and lateral mandibular incisors were divided into six groups and sectioned 3 mm from the incisal edge, using a diamond disk. Two reattachment techniques were applied: (a) bonding, using the Single Bond adhesive system and FiltekZ250 composite resin, followed by placement of a chamfer on the fracture line that was filled with composite resin (Groups 1, 3 and 5); and (b) use of the same bonding technique after dentin removal from the tooth fragment (Groups 2, 4 and 6). The following hydration treatments were applied to the fragments before bonding: (a) 48-h hydration (Groups 1 and 2); (b) 48-h dehydration (Groups 3 and 4); (c) 48-h dehydration followed by rehydration 30 min before bonding (Groups 5 and 6). The reattached teeth were mounted in acrylic resin cylinders and stored in distilled water for 24 h. The specimens were fractured at a speed of 1 mm min(-1) in a universal testing machine. The following mean fracture strengths (kgf) were recorded: (G1) 12.9 +/- 0.6; (G2) 18.8 +/- 4.8; (G3) 7.3 +/- 1.5; (G4) 15.2 +/- 2.4; (G5) 13.4 +/- 2.2; and (G6) 17.1 +/- 3.2. Analyses using two-way anova and the Tukey test (P < 0.01) revealed significant differences between the restorative techniques and the hydration treatments. The bonding technique that incorporated dentin removal from the fragment before bonding showed greater fracture strength across all groups. Fragment dehydration for 48 h caused a reduction in fracture strength, which was recovered by a 30-min rehydration.

SEED TECHNOLOGY AND SEED ENHANCEMENT

This paper reviews the uses, properties and manufacture of the main array of ‘seed enhancement technologies’ that are implemented in current commercial practice, with a particular emphasis on cultivated horticultural and ornamental species. Recent developments, as well as some of the newer technical approaches that are still in the research or at an early commercial stage, are covered. Coating technologies - pelleting, encrusting and filmcoating - are now used increasingly widely to facilitate seed planting, by altering seed shape, weight and surface texture, improving seed-soil contact, or manipulating imbibition. They are also used to deliver materials such as micronutrients and crop protection agents, including the high-dose systemic insecticides. New pellet manufacturing techniques, using rotary coaters, have provided an alternative to traditional ‘pan coating’. Hydration treatments manipulate vigour or physiological status, such as by priming, steeping, and pregermination. These treatments are used to make germination and seedling growth more rapid and synchronous in the seedbed in the open field or in protected conditions, and better tolerate environmental stresses. Both priming and coating technologies can also deliver beneficial microorganisms from seeds to crops. Organic farming market standards are stimulating the evaluation and optimization of methods to produce healthy planting material and new seed sanitation treatments as alternatives to fungicides or conventional hot water or bleach treatment while retaining seed viability in storage. Sorting on the basis of colour, X-ray analysis of internal structures or buoyant density in solvents offer the ability to remove weak or dead seeds, and hence ‘upgrade’ seedlot quality.

Hydration and pre-osmotic treatments on canola rape seeds (Brassica napus L.)

Hydration and pre-osmotic treatments on canola rape seeds (Brassica napus L.)

Enhanced germination, emergence and seedling vigour of Leucaena leucocephala using hardening hydration and acid shock treatments

Enhanced germination, emergence and seedling vigour of Leucaena leucocephala using hardening hydration and acid shock treatments

Use of Hydration, Germination, and α-Galactosidase Treatments to Reduce Oligosaccharides in Dry Beans

N. J. M N. J. M N. J. M N. J. M ABSTRACT: r r resulted in 51% ± 3.0%, 30% ± 1.9%, and 46% ± 1.9% r esulted in 51% ± 3.0%, 30% ± 1.9%, and 46% ± 1.9% r esulted in 51% ± 3.0%, 30% ± 1.9%, and 46% ± 1.9% r esulted in 51% ± 3.0%, 30% ± 1.9%, and 46% ± 1.9% r esulted in 51% ± 3.0%, 30% ± 1.9%, and 46% ± 1.9% reduction in total r eduction in total r eduction in total r eduction in total r eduction in total raffinose and stachy affinose and stachy affinose and stachy affinose and stachy affinose and stachyose for black beans ose for black beans ose for black beans ose for black beans ose for black beans, red beans beans beans beans, and navy beans , and navy beans , and navy beans , and navy beans , and navy beans, respectively. Ger er er er ermination tr mination tr mination tr mination tr mination treatment r eatment r eatment r eatment r eatment resulted in 61% ± 12%, 61% ± 1.9%, and 70% ± 2.8% esulted in 61% ± 12%, 61% ± 1.9%, and 70% ± 2.8% esulted in 61% ± 12%, 61% ± 1.9%, and 70% ± 2.8% esulted in 61% ± 12%, 61% ± 1.9%, and 70% ± 2.8% esulted in 61% ± 12%, 61% ± 1.9%, and 70% ± 2.8% r r r reduction in total r eduction in total r eduction in total r eduction in total r eduction in total raffinose and stachy affinose and stachy affinose and stachy affinose and stachy affinose and stachyose for black beans ose for black beans ose for black beans ose for black beans ose for black beans, red beans

An Update on Voice Research in the United States

An Update on Voice Research in the United States

Effect of metal content and calcination–hydration on the environment of V in zeolites prepared by impregnation of SiBEA with V IVOSO 4 solution

The presence of different V V species in VSiBEA zeolite prepared by impregnation in air of dealuminated BEA zeolite with aqueous V IVOSO 4 solution is evidenced by diffuse reflectance UV–Visible and photoluminescence spectroscopies. The former technique shows that in as prepared VSiBEA with 0.26 and 0.68 wt%, V is present as lattice mononuclear tetrahedral species. In calcined-hydrated VSiBEA whatever the V content (0.26 and 0.68 wt%) and in as prepared VSiBEA with 1.36 V wt%, V is present both as lattice mononuclear tetrahedral and extra-lattice octahedral species. However, only photoluminescence spectroscopy is able to clearly distinguish three kinds of distorted lattice mononuclear tetrahedral V V species, whose relative amounts depend on V content and calcination–hydration treatments. Moreover, FT-IR demonstrates that the presence of V in dealuminated BEA zeolite generates Brønsted and Lewis acidic sites whose amounts increase with V content.

Effectiveness of electrolytes at alleviating dehydration and improving carcass characteristics of adult sheep in lairage

The aim of this work was to examine the effectiveness of a commercial electrolyte mixture in alleviating dehydration and improving carcass characteristics of adult sheep under commercial processing conditions. Two separate experiments were conducted to investigate this aim. Experiment 1 had 2 hydration treatments (water with and without electrolytes) and sheep commenced their treatments on their arrival at the abattoir. Animals were then slaughtered at the lairage times of 24, 48 or 72 h. Experiment 2 had the same treatments and an additional no water (no electrolyte) treatment. In the second experiment only, animals from each of the treatment groups were allocated into 2 stimulation groups, so that on the production line the carcasses were either treated with high voltage stimulation or not treated. Experiment 2 animals were grazed for 2 weeks at the abattoir prior to commencement of the treatments. Animals were slaughtered after a lairage time of 24, 48 or 72 h, except for animals on the no-water treatment: these animals had lairage times of 24 or 48 h only. It was found in both experiments that there was no difference (P&gt;0.05) between the water treatments for all carcass and meat quality traits measured. Lairage time had an effect (P&lt;0.05) on urine specific gravity in both experiments. Urine specific gravity decreased as lairage time increased in experiment 1, but an opposing trend was found in experiment 2. In experiment 1, as lairage time increased, GR (total tissue depth at the 12th rib) decreased. Electrical stimulation in experiment 2 lowered (P&lt;0.05) the initial pH and interacted with lairage time causing differences in cook loss for meat aged for 1 or 7 days, but had no impact on other traits.

Alleviation of dormancy in annual ryegrass (Lolium rigidum) seeds by hydration and after-ripening

The effect of hydration (priming) treatment on dormancy release in annual ryegrass seeds from two populations was investigated. Hydration duration, number, and timing with respect to after-ripening were compared in an experiment involving 15 treatment regimens for 12 wk. Seeds were hydrated at 100% relative humidity for 0, 2, or 10 d at Weeks 1, 6, or 12 of after-ripening. Dormancy status was assessed after each hydration treatment by measuring seed germination at 12-hourly alternating 25/15 C (light/dark) periods using seeds directly from the hydration treatment and seeds subjected to 4 d postpriming desiccation. Seeds exposed to one or more hydration events during the 12 wk were less dormant than seeds that remained dry throughout after-ripening. The longer hydration of 10 d promoted greater dormancy loss than either a 2-d hydration or no hydration. For the seed lot that was most dormant at the start of the experiment, two or three rather than one hydration event or a hydration event earlier rather than later during after-ripening promoted greater dormancy release. These effects were not significant for the less-dormant seed lot. For both seed lots, the effect of a single hydration for 2 d at Week 1 or 6 of after-ripening was not manifested until the test at Week 12 of the experiment, suggesting that the hydration events alter the rate of dormancy release during subsequent after-ripening. A hydrothermal priming time model, usually used for modeling the effect of priming on germination rate of nondormant seeds, was successfully applied to dormancy release resulting from the hydration treatments.

Comparison of the effects of bioactive compounds and hydration treatments on germination and cell cycle activity of sugar-beet seeds

Summary Seeds of two sugar-beet cultivars, differing in vigour, were exposed to hydration in water and soaking in two bioactive compounds. Cell cycle activity and laboratory germination capacity were determined under standard conditions after four and seven days. Two parameters were used to estimate vigour of the seeds: seedling length vigour index (percentage of seeds with radicle/hypocotyl axis over 15 mm long after 96 hours at 20°C) and germination capacity after six days at 10°C. The G 2 /G 1 ratio increased in all samples after hydration treatment and, in some cases, after bioactive compound treatment. These treatments also improved vigour of the seeds; however, application of bioactive compounds did not result in any advantage over hydration in water. Experimental and discussion Algal extracts are biological material which may be useful for controlling seed germination. Some algal products are already commercially used as a soil or foliar fertilizer to improve vigour, yield and health of crops (Wysocka-Owczarek, 1997). For example, when added to a growth substrate, they maintain its humidity and promote germination of some tropical plant species (Vazquez

Effects of hydration and scarification treatments on the germination of Trichospermum mexicanum

Effects of hydration and scarification treatments on the germination of Trichospermum mexicanum

Sequential Steps of Ammoniation of the Microporous Silicoaluminophosphates H-SAPO-34 and H-SAPO-37 Investigated by In Situ CF MAS NMR Spectroscopy

By studying the ammoniation of the silicoaluminophosphate-type zeolites H-SAPO-34 and H-SAPO-37 by in situ 1 H and 2 7 Al MAS NMR under continuous-flow (CF) conditions, a two-step adsorption process was determined. The first ammoniation step consists of an adsorption of ammonia exclusively at Bronsted acidic bridging OH groups (SiOHAI), leading to the formation of ammonium ions (NH 4 -form). The second ammoniation step, which occurs at a higher ammonia coverage, consists of a coordination of ammonia molecules to framework Al atoms in ≡P-O-Al≡ bridges. This second adsorption step causes a change of the aluminum coordination from a tetrahedral coordination to an octahedral coordination. The ammonia coordination to Al atoms is reversible when the material is purged at 413 K. The hydration of NH 4 -form silicoaluminophosphates (ammoniated bridging OH groups) causes a coordination of water molecules exclusively to Al atoms in ≡P-O-Al≡ bridges, leading to a hydrolysis of the framework. Therefore, a hydrolysis of the silicoaluminophosphate framework is hindered if the bridging OH groups (SiOHAI), as well as the aluminophosphate framework (≡P-O-Al≡), is covered by ammonia. The latter may support the stabilizing effect of preloaded ammonia on H-form silicoaluminophosphates toward hydration and weak hydrothermal treatments, as recently observed for H-SAPO-34.

HPLC Determination of Trehalose in Selaginella lepidophylla Plants

A sensitive and selective assay of trehalose is presented for its determination in anhydrobiotic organisms that are able to tolerate lack of water because of their ability to synthesize large quantities of this disaccharide. The disaccharide was extracted with water and ethanol 80%, followed by normal bonded phase‐high performance liquid chromatography and refraction index measurement. The assay demonstrated to be fast with good linear and high precision response. The column and detector performance show good retention, selectivity, and efficiency. Based on replicated analysis of standards over a range of 0.2–10 mg/mL, the method is accurate (90–100%) and precise (CV of 5% daily). The concentration of trehalose in Selaginella lepidophylla plants, subjected to hydration and dehydration treatments at seven different incubation times, ranged between 0.61 and 17.99 mg/mL. At the same time, the presence of fructose, glucose, and sucrose were analyzed. The standard deviation of plant samples were about 0.003–1.51%, where the detection limit was 0.01 mg/mL.

Study of the structural evolution of the 10 Å unstable hydrate of kaolinite during dehydration by XRD and SAXS

This work deals with understanding the structural evolution of the dehydration of the 10 Å unstable hydrate of kaolinite. The method used to characterize this hydrate is based on a comparison between the experimental and the calculated X-ray diffraction profiles. The study was achieved in two steps: (i) the quantitative interpretation of 00lreflections enabled the determination of the number of intercalated water molecules, their positions and the stacking mode of the clay layers along the normal to the (a,b) plane; and (ii) the study of thehklreflections withhand/ork≠ 0 enabled the characterization of the structural evolution in the (a,b) plane of the hydrated kaolinite during dehydration. The hydrate is made up of two demixed phases. The first phase is homogenous and corresponds to a 10 Å hydrated kaolinite, characterized by two H2O molecules per Si2Al2O5(OH)4situated atZ= 7.1 Å from the surface oxygen. Two adjacent layers are translated with respect to each other, withT1= −0.155a+ 0.13b+ 10n. The abundance of this phase decreases during dehydration. The second phase is made up of 10 Å hydrated layers, 8.4 Å hydrated layers and 7.2 Å dehydrated kaolinite layers, randomly interstratified. The abundance of this second phase increases during dehydration. The corresponding interlayer shifts are respectivelyT21= −0.155a+ 0.13b+ 10nfor the 10 Å hydrated layer,T22= −0.355a+ 0.35b+ 8.4nfor the 8.4 Å hydrate andT23= −0.36a− 0.024b+ 7.2nfor the natural kaolinite. In addition to these interlayer shifts, some translation defects are introduced, such as −b/3, which exists in the initial kaolinite. The interpretation of the small-angle X-ray scattering (SAXS) patterns showed that the particle thickness remained the same before and after the hydration treatments, whereas X-ray diffraction (XRD) results indicated that the hydration of kaolinite caused a decrease of the mean number of layers \bar m per crystallite from 40 to 20 layers. This decrease is related to the presence of H2O molecules situated within the micropores in the kaolinite particles that leave their interlayer space after heating at 573 K. The resulting dehydrated compound is characterized by the same basal distance and mean number of layers \bar m per crystallite as for the natural kaolinite, while the proportion of the defects, such as the −b/3 translation, increases in the completely dehydrated compound (45%) compared with the natural kaolinite (10%).

Effect of controlled hydration treatments on storage longevity of aubergine seeds during development

The effects of controlled hydration treatments on seed storage longevity of aubergine (Solanum melongena L.) seeds harvested 45, 50, 55, and 60 days after anthesis (daa) in 1999 and 2000, were studied. Treated and control seeds were stored at 30 oC with 12% moisture content and sampled monthly for up to 180 days. Longevity was assessed by changes in P50 (half-viability period) and regression coefficients of the survival curves following probit analysis. The treatments extended P50 values between 19 and 65 days longer than the control, depending on the seed lot. Controlled hydration also substantially decreased life span of seeds in time (regression coefficient). The maximum advantage was obtained in 45 and 60 daa in 1999 and 2000 during development, respectively. Results showed that controlled hydration treatment could be used to prolong the storage longevity of aubergine seed lots from different stages of development.

Reversible Color Change of Chromophores in Zeolites by Direct Interaction with Alkali Metal Cations

Reversible color change of a neutral chromophore in a cationic zeolite was achieved by controlling the direct interaction between alkali-metal cations and chromophores. As a typical combination of the cationic host and the neutral chromophore, Na+-type mordenite accommodating N,N-dimethyl-p-nitroaniline (DMpNA) was prepared. The UV−vis spectra showed an extraordinarily large shift of the absorption band of DMpNA by 85 nm after the dehydration treatment of the hydrated sample. Furthermore, the absorption band was shifted reversibly by the dehydration and hydration treatments. Solid-state 23Na MAS NMR with a cross-polarization technique revealed that DMpNA molecules were present in the neighborhood of the dehydrated Na+ in the dehydrated form while the molecules were distant from 23Na in the hydrated form. These results indicated that adsorbed water molecules controlled the strength of the interaction between Na+ and DMpNA molecules.

Effects of Hydration Treatments on the Phase Transition of Anodic Alumina Oxide Layers

Hydration treatments were performed on the pure aluminum substrate at <TEX>$100^{\circ}C$</TEX> followed by anodizing and heat treatments on the layers. The transformation behaviors of the oxide layers according to the hydration treatment were studied using TEM, XRD, RBS etc. Above <TEX>$90^{\circ}C$</TEX> the hydrous oxide film could be formed, which were turned out to be hydrous oxides(AlOOH <TEX>$nH_2$</TEX>O). The anodization on the hydrous oxide film was more effective for the transition of amorphous anodic oxides to the crystalline <TEX>$\Upsilon-Al_2$</TEX> <TEX>$O_3$</TEX> comparing with the case for anodizing on the aluminum substrate without hydration treatment And additional heat treatments were also helpful for the acceleration of the transformation of the hydrous oxide to <TEX>$\Upsilon-Al_2$</TEX> <TEX>$O_3$</TEX>. During the heat treatment the interface between <TEX>$\Upsilon-Al_2$</TEX> <TEX>$O_3$</TEX>and the hydrous oxide layers migrated to the outer side of hydrous layer.

THE EFFECT OF POST-STORAGE HYDRATION TREATMENTS ON VIABILITY OF ONION SEEDS

The effects of hydration (priming and humidification) treatments at 15°C on the germination of onion seeds (i.e., long-day cvs Valencia and Corum; short-day cvs TEG-502 and Banko) with reduced viability were investigated. Osmotic solutions of PEG-8000 at -0.5 and -1.0 MPa were used for 1, 2 and 3 days. Humidification treatments were also conducted for 1, 2 and 3 days, considering the results of preliminary experiments. At the end of the experiments, in cv. Valencia, all the priming treatments leaded to a decline in the germination percentages of the seeds. Priming treatment with -0.5 MPa for 1 and 2 days decreased the germination percentage in cv. Corum, while the other treatments increased it. Nevertheless, all the priming treatments increased the germination percentage in cvs TEG-502 and Banko. As far as the mean germination time is concerned, there was no significant difference compared with control, following the priming treatments with PEG-8000 in cvs Valencia and Corum. However, all the treatments increased the mean germination time in cvs TEG-502 and Banko. Humidification treatments increased the germination percentages of seeds in all cultivars. Moreover, all humidification treatments shortened the mean germination time. Humidification treatments gave better results compared with priming treatments, in terms of both germination percentage and mean germination time. The best results were obtained from 1-day and 3-day humidification treatments in long-day and short-day onion seeds, respectively.

Effect of hydration treatments on seed parameters of different lettuce (Lactuca sativa L.) seed lots

The influence of hydration treatments on seed parameters of lettuce seed lots with different initial quality was investigated. Nine seed lots were treated by prehydration (for 3, 6, 12 and 24 hours) and by osmopriming in polyethylene glycol 6,000 solution (for 24, 72 and 144 hours) with osmotic potential &amp;ndash;1.5 MPa. The result of hydration treatment depends on seed lot attributes. The germination percentage is not a sufficient criterion for determination of seed suitability for hydration treatment. A possible complementary parameter can be the mean time of germination (MTG) with high correlation between untreated and treated seed lots. The effect of hydration also depends on the hydration method and time of treatment. The osmopriming is a more suitable method for lettuce seed than prehydration. Generally, a shorter time of hydration (till 6&amp;nbsp;hours at prehydration and till 72 hours at priming) proved more effective on the parameters of lettuce seed lots after treatment.

Seed Enhancements to Improve Spinach Germination

Rapid, synchronized, and high percentage of germination is required for commercial spinach (Spinacia oleracea L.) production using hydroponic techniques. Seed treatments examined to improve seed germination were: 1) decoating; 2) leaching in water; and 3) soaking seeds for 4 hours in 0.5% NaOCl, leaching for 15 hours in water, and sowing in 0.3% H2O2 (this treatment will be referred to as NaOCl/H2O2). Germination studies were conducted on four cultivars at a constant 18 °C (optimal) or 30 °C (inhibitory). At 18 °C, germination rate (T50) was maximized by both hydration treatments, but uniformity of germination (Tsd) was greatest for decoated seeds; final germination was ≥89% for all treatments. At 30 °C, decoating resulted in greatest uniformity of germination. The NaOCl/H2O2 treatment resulted in highest germination (94%) at the high temperature, whereas decoating was least effective (69%). Reduced germination of decoated seeds was attributed to atypical germinants. Cultivars differed in response to the treatments at both temperatures. Component analysis of the NaOCl/H2O2 treatment was studied with two slow-to-germinate cultivars. Treatment with H2O2, with or without NaOCl, improved the rate, uniformity, and percentage of germination of seeds of both cultivars, but NaOCl alone did not. Pericarp removal or pericarp removal plus NaOCl/H2O2 treatments reduced variability in germination time and enhanced speed of germination at 30 °C, but decoating produced a higher percentage of atypical seedlings than did other treatments. Therefore, the NaOCl/H2O2 treatment is recommended for growers who are unable to maintain cool germination temperatures and/or cannot afford the costs associated with cooling. If growers can maintain a germination temperature of ≈18 °C, decoated seeds are preferable, based on the high uniformity of germination.