Enhancing malting performance of harder barley varieties through ultrasound treatment

Harder kernels of barley are regarded as one of the factors that restrict water and enzyme movement within the endosperm during malting. A comprehensive study of two domestic varieties was performed for evaluating malting quality. Both β-glucan and total protein content of the Chinese domestic barley (Ganpi-6 and Kenpi-14) were significantly higher than Copeland. Grain hardness of the Chinese domestic barley was higher and water uptake ratio was lower compared with the Copeland. During germination, the expression levels of NCED1, NCED2 (major key regulatory enzymes for abscisic acid biosynthesis genes) were higher, whereas gibberelic acid (GA) synthesis genes (GA20ox1, GA2ox3, GA3ox2) were lower in the Ganpi-6, Kenpi-14 compared with Copeland. These two domestic barley varieties also showed significantly lower limit dextrinase and β-glucanase activity compared with Copeland. Ultrasound treatment improved the malting quality of Ganpi-6 by enhancing water uptake and GA synthesis gene expression increased. Therefore, these findings provided insights into the future direction on the utilization of ultrasonication for the applications towards the improvement of the harder barley variety.

Direct photodegradation of internally mixed sodium chloride and malonic acid single aerosols: Impact of the photoproducts on the hygroscopic properties of the particles

Sea-salt aerosols (SSA) are one of the key natural aerosols in our atmosphere, consisting predominantly of sodium chloride (NaCl). Throughout their atmospheric transport, these aerosols undergo complex internal mixing, giving rise to a rich variety of inorganic and organic species, including dicarboxylic acids. This study investigates firstly the composition and deliquescence properties of coarse particles containing pure malonic acid (MA2, CH2(COOH)2) and internally mixed NaCl and MA2, by means of an acoustic levitation system coupled with a Raman microspectrometer. Secondly, we report here the first experimental observation and characterization of the products arising from photochemical reactions under UV-Visible irradiation (338 ≤ λ ≤ 414 nm) in the absence of an oxidant under acoustic levitation conditions in MA2 and NaCl/MA2 aerosols. Furthermore, the impact of photodegradation on the hygroscopic properties of these particles is examined. We confirmed the irreversible formation of monosodium malonate (NaMA, HOOCCH2COONa), which coexists with NaCl or MA2 on non-irradiated particles. We also demonstrated the formation of oxalic acid (OA2, HOOC-COOH) within irradiated MA2 droplets and the appearance of glyoxylic acid (GlyA, HCOCOOH) in NaCl containing droplets. The photolysis process exerts a marked effect on the hygroscopic properties of the particles, resulting in a shift in deliquescence transitions toward higher relative humidity (RH) values. This study contributes to the understanding of the intricate physicochemical processes involved in SSA during their atmospheric transport. Likewise, this work sheds light on the impacts of these types of aerosols on cloud formation and climate change.

Structure-Property Relationships of Hydrogel-based Atmospheric Water Harvesting Systems

Atmospheric water harvesting (AWH) is considered one of the promising technologies to alleviate the uneven-distribution of water resources and water scarcity in arid regions of the world. Hydrogel-based AWH materials are currently attracting increasing attention due to their low cost, high energy efficiency and simple preparation. However, there is a knowledge gap in the screening of hydrogel-based AWH materials in terms of structure-property relationships, which may increase the cost of trial and error in research and fabrication. In this study, we synthesised a variety of hydrogel-based AWH materials, characterized their physochemcial properties visualized the electrostatic potential of polymer chains, and ultimately established the structure-property-application relationships of polymeric AWH materials. Poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPS) hydrogel is able to achieve an excellent water adsorption capacity of 0.62 g g-1 and a high water desorption efficiency of more than 90 % in relatively low-moderate humidity environments, which is regarded as one of the polymer materials with potential for future AWH applications.

Fast time-resolved micro-CT imaging of pharmaceutical tablets: Insights into water uptake and disintegration

We use dynamic micro-computed tomography (micro-CT) with a high temporal resolution to visualize water penetration through the porous network of immediate-release pharmaceutical solid tablets and characterize dynamic swelling and disintegration mechanisms. We process the micro-CT images using two theoretical scenarios that reflect different paths of pore structure evolution: a scenario where tablet porosity remains constant during the swelling process and a scenario where the tablet porosity progressively diminishes and eventually closes during the swelling process. We calculate the time evolution of the volume of water absorbed by the tablet and, specifically, absorbed by the excipients and the pore structure, as well as the formation and evolution of cracks. In turn, the three-dimensional disintegration pattern of the tablets is reconstructed. Restricting attention to the limiting scenario where tablet porosity is assumed fixed during the swelling process, we couple liquid penetration due to capillary pressure described by the Lucas-Washburn theory with the first-order swelling kinetics of the excipients to provide a physical interpretation of the experimental observations. We estimate model parameters that are in agreement with values reported in the literature, and we demonstrate that water penetration is dominated by intra-particle porosity rather than inter-particle porosity.

Implications of ageing effects on thermal and mechanical properties of PMMA-based bone cement for THA revision surgery

Loosening and infection are the main reasons for revision surgery in total hip arthroplasty (THA). Removing partially detached cemented implant components during revision surgery remains challenging and poses the risk of periprosthetic bone damage. A promising approach for a gentler removal of partially detached prostheses involves softening the PMMA-based bone cement by heating it above its glass transition temperature (TG), thus loosening the implant-cement bond. It is assumed that the TG of PMMA-based bone cement decreases in-vivo due to the gradual absorption of body fluid. Reliable data on TG are essential to develop a heat-based method for removing cemented implant components during revision surgery. The effect of water absorption was investigated in-vitro by ageing PMMA-based bone cement samples for different periods up to 56 days in both Ringer's solution (37 °C) and air (37 °C and 30% humidity). Subsequently, the TG and Vicat softening temperatures of the samples were determined by differential scanning calorimetry and Vicat tests, respectively, according to prescribed methods. Over the entire ageing period, i.e. comparing one day of ageing in air and 56 days in Ringer's solution, the Vicat softening temperature dropped by 16 °C, while the TG dropped by 10 °C for Palacos® R PMMA-based bone cement. Water absorption over time correlated significantly with the Vicat softening temperature until saturation of the PMMA-based bone cement was reached. Based on the TG and Vicat softening temperature measurements, it can be assumed that in body-aged bone cement, an optimal softening can be achieved within a temperature range of 85 °C-93 °C to loosen the bond between the PMMA-based bone cement mantle and the prosthesis stem. These findings may pave the way for a gentler removal of the implant in revision THA.

Design of tropinium-functionalized anion exchange membranes for acid recovery via diffusion dialysis process

Diffusion dialysis (DD) process utilizing anion exchange membranes (AEMs) is an environmentally-friendly and energy-efficient technology. From acidic wastewater, DD is needed for acid recovery. This research reports the development of a series of dense tropinium-functionalized AEMs via solution casting method. Fourier Infrared transform (FTIR) spectroscopy verified the successful preparation of AEMs. The developed AEMs exhibited a dense morphology, featuring 0.98-2.42 mmol/g of ion exchange capacity (IEC), 30-81% of water uptake (W_R) and 7-32% of linear swelling ratio (LSR). They displayed exceptional mechanical, thermal and chemical stability and were employed for acid waste treatment from HCl/FeCl₂ mixtures via DD process. AEMs possessed 20 to 59 (10^-3 m/h) and 166 to 362 of acid diffusion dialysis coefficient (U_H⁺) and separation factor (S) respectively at 25 °C. Compared to DF-120 commercial membrane (U_H⁺ = 0.004 m/h, S = 24.3), their DD efficiency was improved under identical experimental conditions.

Water absorption characterization of boron compounds-reinforced PLA/flax fiber sustainable composite

Biocomposites are widely used in construction, packaging, and automotive applications such as seatbacks, door panels, headliners, and dashboards, as well as industrial composting. The purpose of this study is to look into the effects of three different boron compounds (borax boric, acid combines, zinc borate, and ulexite) on the mechanical and microstructural properties of flax fiber/PLA biocomposites at different water uptake times. 7 different biocomposites were studied for this purpose: control, 3UF, 5UF, 3ZBF, 3BxBcF, 5BxBcF, and 5ZBF. Extrusion was used to create homogenous chopped flax fiber-reinforced PLA biocomposites, which were then injection molded. Alkali treatment on flax fiber surfaces was applied to improve interfacial adhesion between fiber and matrix. Water uptake tests were performed at room temperature for soaking times of 24, 50, 168, 240, 330, 480, 550, 600, and 750 h. The addition of boron compounds increases water gain from 4.4 % to 6.1 %, according to sorption results. The tensile elongation at break values of the composites increased slightly after short-term water absorption. SEM images showed that alkali-treated flax fibers and boron compounds dispersed uniformly in the PLA matrix. After 750 h of immersion, the addition of boron fillers to PLA/flax composite increased Young's Modulus and flexural modulus by about 50 % and 72 %, respectively, in comparison to the control composite sample. The addition of boric acid: borax combines into the PLA/flax composite slowed the rate of decline in tensile and flexural strength after various immersion times. Finally, using MINITAB software, the experimental results were subjected to a one-way analysis of variance (ANOVA).

Fabrication of trimethylphosphine-functionalized anion exchange membranes for desalination application via electrodialysis process

The design of conductive, improved durable and selective anion exchange membranes (AEMs) for desalination application via electrodialysis (ED) process is critical for a more sustainable future. This work reports the design of a series of homogeneous trimethylphosphine (TMP)-functionalized anion exchange membranes (AEMs) for desalination application via electrodialysis (ED) process. Physico-chemical characterization and electrochemical performance of the trimethylphosphine-functionalized anion exchange membranes was conducted and the activity found to be tuned by varying the quantity of trimethylphosphine into the membrane architecture. For anion exchange membranes M1 to M4, the ion exchange capacity (IEC) was increased from 1.35 to 2.16 mmol/g, water uptake (W_R) from 4.30 to 17.72%, linear expansion ratio (LER) from 3.70 to 12.50% with enhancing the quantity of trimethylphosphine into the polymer architecture. The ionic resistance decreased from 15.14 to 2.61 Ω cm² with increasing quantities of trimethylphosphine whereas transport number increased from 0.98 to 0.99. The performance of synthesized trimethylphosphine-functionalized anion exchange membranes in desalination of NaCl was evaluated via electrodialysis process (flux of 3.42 mol/m². h and current efficiency of 64.30%). Results showed that the prepared trimethylphosphine-functionalized membrane (optimum M4) possess improved desalination performance as compared to commercial membrane Neosepta AMX under identical experimental conditions.

Contribution of deep soil layers to the transpiration of a temperate deciduous forest: Implications for the modelling of productivity

Climate change is imposing drier atmospheric and edaphic conditions on temperate forests. Here, we investigated how deep soil (down to 300 cm) water extraction contributed to the provision of water in the Fontainebleau-Barbeau temperate oak forest over two years, including the 2018 record drought. Deep water provision was key to sustain canopy transpiration during drought, with layers below 150 cm contributing up to 60% of the transpired water in August 2018, despite their very low density of fine roots. We further showed that soil databases used to parameterize ecosystem models largely underestimated the amount of water extractable from the soil by trees, due to a considerable underestimation of the tree rooting depth. The consensus database established for France gave an estimate of 207 mm for the soil water holding capacity (SWHC) at Fontainebleau-Barbeau, when our estimate based on the analysis of soil water content measurements was 1.9 times as high, reaching 390 ± 17 mm. Running the CASTANEA forest model with the database-derived SWHC yielded a 185 gC m^-2 y^-1 average underestimation of annual gross primary productivity under current climate, reaching up to 687 ± 117 gC m^-2 y^-1 under climate change scenario RCP8.5. It is likely that the strong underestimation of SWHC that we show at our site is not a special case, and concerns a large number of forest sites. Thus, we argue for a generalisation of deep soil water content measurements in forests, in order to improve the estimation of SWHC and the simulation of the forest carbon cycle in the current context of climate change.

Sweet cherry flesh cells burst in non-random clusters along minor veins

Sweet cherry flesh cells burst when exposed to water but they do so in clusters indicating heterogeneity with respect to osmotic concentration, which depends on proximity to a minor vein. Water plays a key role in cracking in sweet cherry fruit. Magnetic resonance imaging has previously indicated preferential partitioning of water along veins. A more negative osmotic potential along veins seems the likely explanation. Here we establish if cell bursting in mature sweet cherry fruit is also associated with the veins. Cell bursting was identified by a novel light microscope technique involving exposure of a cut fruit surface to water or to sucrose solutions. Upon exposure to water there was no bursting of skin cells but for cells of the flesh (mesocarp) bursting increased with time. When the cut surface was exposed to sucrose solutions of decreasing osmotic concentrations (increasing water potentials) the incidence of cell bursting increased from hypertonic (no bursting), to isotonic, to hypotonic. Cell bursting in the outer mesocarp occurred primarily in the vicinity of minor veins that in the inner mesocarp was primarily between radial veins. The median distance between a minor vein and a bursting cell (mean diameter 0.129 mm) was about 0.318 mm that between a radial vein and a bursting cell was about 0.497 mm. In contrast, the distance between adjacent minor veins averaged 2.57 mm, that between adjacent radial veins averaged 0.83 mm. Cell bursting tends to occur in clusters. Mapping of cell bursting indicates (1) that a seemingly uniform population of mesocarp cells actually represents a heterogeneous population with regard to their cell osmotic potentials and (2) cell bursting afflicts clusters of neighbouring cells in the vicinities of minor veins.

Putting Plant Roots at Light: Temporal Imaging of Plant Roots and Soil Water with a Light Transmission Technique for Linking Water and Root Observations to Soil-Plant Models

Estimating how the "hidden half" of plants, that is the roots, take up water or the influences of root system architecture or root physiological properties (such as root hydraulic conductance) on efficiency of water uptake is of prime importance for improving crops against water deficits. To unravel soil-root interactions for water, we describe a system that enables a dynamic imaging of the soil water content and of the root system, from the single root to the whole root system scales.This system uses plants grown in rhizotrons filled with sandy soil and is based on the variable attenuation of the intensity of light transmitted through the rhizotron with soil water content (the rhizotron is nearly translucent when saturated and becomes darker as soil water content decreases). Images of the transmitted light during plant water uptake (or exudation) phases are recorded with a camera, showing a qualitative pattern of water content variations. The gray levels of the image pixels are then quantitatively related to water content with a calibration.This system is affordable and can be easily implemented without specific equipment. It is scalable and quick to allow the phenotyping of a range of plant genotypes relative to their water uptake pattern. This pattern can be then related with root system properties (soil colonization, root architecture ) at different plant stages. In combination with modeling , imaging results help in obtaining physiological parameters such as root hydraulic conductivity, distributed root water uptake rates or root xylem water potential. Combination of modeling and experiment further helps in testing biological and physiological assumptions and in predicting the uptake behavior of plants in the field.

Unique Behavioral Strategies Adopted by Gravid Ghost Crab Ocypode gaudichaudii to Overcome Dehydration Stress while Minimizing Predation Risks

Semi-terrestrial crabs require continual access to water to maintain life-sustaining processes such as circulation and feeding. When they emerge from their burrows during low tide to forage, they face the problem of dehydration as they leave the dampness of their burrows. While foraging above ground, water uptake is elicited through capillary action via the hydrophilic setae near the base of the crab's body. Extruded eggs that are borne on the abdominal flap of females tend to obstruct the contact of the setae with the wet sediment. The behavioral adaptations that enable the gravid female painted ghost crab, Ocypode gaudichaudii, to overcome dehydration stress and minimize predation risks at a sandy shore in Playa Venao, Panama were studied using field observations. Comparison of the morphometric measurements of setal tufts between 30 male and 30 female crabs was made to determine if there were morphological adaptations. Analysis of the water uptake behavior from video footage showed that gravid crabs spent a longer duration on water uptake than crabs that did not carry eggs. For the first time, masquerading behavior of a gravid O. gaudichaudii was observed, in which the crab minimized predatory detection by freezing its movement next to a stone enroute to the lower shore during the day. There was no sexual dimorphism in the length and width of the setal tufts between the male and female adult crabs. The results of this study provide the first evidence that the water-uptake behavior in gravid O. gaudichaudii is dependent on behavioral adaptations, as setal tuft morphology does not differ between the sexes.

Tablet formulation development focusing on the functional behaviour of water uptake and swelling

The functional behaviour of tablets is strongly influenced by their manufacturing process and the choice of excipients. Water uptake and swelling are prerequisites for tablet disintegration, dispersion and hence active pharmaceutical ingredient (API) dissolution. High proportions of polymeric excipients in tablets, which are typically used as API carriers in amorphous solid dispersions (ASDs), may be challenging due to the formation of a gelling polymer network (GPN). In this study, systematic investigations into the formulation development of tablets containing polymeric and other excipients are performed by water uptake and swelling analysis. The impact of tablet composition and porosity as well as pH of the test medium are investigated. The pH affects the analysis results for Eudragit L100-55 and Eudragit EPO. HPMC and Kollidon VA64 inhibit water uptake and swelling of tablets due to the formation of a GPN. High tablet porosity, coarse particle size of the polymer and the addition of fillers and disintegrants can reduce the negative impact of a GPN on tablet performance. The application of lubricants slows down the analysed processes. Water uptake and swelling data are fitted to an empirical model obtaining four characteristic parameters to facilitate the simple quantitative assessment of varying tablet formulations and structural properties.

An improved method for the simultaneous determination of water uptake and swelling of tablets

Water uptake and swelling of tablets are processes occurring during active pharmaceutical ingredient (API) release. Thereby, disintegration is promoted and the enhanced exposure of API surface area to the release medium facilitates API dissolution. An experimental set-up for the simultaneous and time-resolved determination of water uptake and swelling of tablets has been developed. Water uptake was determined with a balance and swelling was determined with a camera. To validate the gravimetrical analysis, real-time water uptake measurements with inert test specimens were performed. The standard deviation of these measurements was considered to depict precision. A complementary gravimetrical analysis was employed to determine accuracy. For both, precision and accuracy, a maximum deviation of 6% was found. An algorithm for the symmetry-based 3D volume reconstruction was applied to obtain volumes of the tablets from 2D images. X-ray micro computed tomography was used to validate the accuracy and the determined volumes were in good accordance within 6% deviation. A case study with binary formulations of a filler and disintegrants confirmed reproducibility and demonstrated the ability of the method to discriminate formulation characteristics, such as disintegrant type, composition and porosity for water uptake and swelling with the necessary temporal resolution.

Temporal offset between precipitation and water uptake of Mediterranean pine trees varies with elevation and season

For climate models that use paleo-environment data to predict future climate change, tree-ring isotope variations are one important archive for the reconstruction of paleo-hydrological conditions. Due to the rather complicated pathway of water, starting from precipitation until its uptake by trees and the final incorporation of its components into tree-ring cellulose, a closer inspection of seasonal variations of tree water uptake is important. In this study, branch and needle samples of two pine species (Pinus pinaster and Pinus nigra subsp. laricio) and several water compartments (precipitation, creek, soil) were sampled over a two-year period and analyzed for the temporal variations of their oxygen and hydrogen stable isotope ratios (δ¹⁸O and δ²H) at five sites over an elevation gradient from sea level to around 1600 m a.s.l. on the Mediterranean island of Corsica (France). A new model was established to disentangle temporal relationships of source water uptake of trees. It uses a calculation method that incorporates the two processes mostly expected to affect source water composition: mixing of waters and evaporation. The model results showed that the temporal offset from precipitation to water uptake is not constant and varies with elevation and season. Overall, seasonal source water origin was shown to be dominated by precipitation from autumn and spring. While autumn precipitation was a more important water source for trees growing at mid- (~800-1000 m a.s.l) and high-elevation (~1600 m a.s.l.) sites, trees at coastal sites mostly took up water from late winter and spring. These findings show that predicted decreases in precipitation amounts during the wet season in the Mediterranean can have strong impacts on water availability for pine trees, especially at higher elevations.

Comparison of the individual salinity and water deficit stress using water use, yield, and plant parameters in maize

Though water deficit and salinity effects on plants have similarities, they are physiologically different. This motivated us to separately explore the effects of salinity and water deficit on water consumption, yield, and some plant parameters for maize (Zea mays L., var. SC704). Greenhouse experiments were conducted during two seasons. In one experiment, maize was cultivated in wet soil (matric potential of - 10 kPa), and the irrigation water salinity was varied between treatments (osmotic potentials up to - 336 kPa). In a parallel experiment, five water deficit levels were maintained by irrigating with water to accomplish the same daily water uptake as in the salinity treatments. The experiments were conducted in pots with a randomized design and four replicates. Salinity and water deficit stress significantly affected yield and other plant parameters. However, root dry matter in autumn was not significant. We observed a profound effect of evaporative demand on most of the plant parameters and water use, such as water use efficiency (WUE). For same water use rate, the values of osmotic and matric potential were different. In spring season, the ratios of matric to osmotic potential were 0.25, 0.46, 0.44, and 0.43 in corresponding D₁, D₂, D₃, and D₄ water deficit and S₁, S₂, S₃, and S₄ salinity treatments. For autumn season, these ratios were 0.26, 0.36, 0.34, and 0.36. We concluded crop models that lump water deficit and salinity (additively or multiplicatively) to predict yields can result in inappropriate predictions.

Novel fluoride rechargeable dental composites containing MgAl and CaAl layered double hydroxide (LDH)

OBJECTIVE

This study aims to incorporate 2:1 MgAl and 2:1 CaAl layered double hydroxides (LDHs) in experimental dental-composites to render them fluoride rechargeable. The effect of LDH on fluoride absorption and release, and their physico-mechanical properties are investigated.

METHODS

2:1 CaAl and 2:1 MgAl LDH-composite discs prepared with 0, 10 and 30wt% LDH were charged with fluoride (48h) and transferred to deionized water (DW)/artificial saliva (AS). Fluoride release/re-release was measured every 24h (ion-selective electrodes) with DW/AS replaced daily, and samples re-charged (5min) with fluoride every 2 days. Five absorption-release cycles were conducted over 10 days. CaAl and MgAl LDH rod-shaped specimens (dry and hydrated; 0, 10 and 30wt%) were studied for flexural strength and modulus. CaAl and MgAl LDH-composite discs (0, 10, 30 and 45wt% LDH) were prepared to study water uptake (over 7 weeks), water desorption (3 weeks), diffusion coefficients, solubility and cation release (ICP-OES).

RESULTS

CaAl LDH and MgAl LDH-composites significantly increased the amount of fluoride released in both media (P<0.05). In AS, the mean release after every recharge was greater for MgAl LDH-composites compared to CaAl LDH-composites (P<0.05). After every recharge, the fluoride release was greater than the previous release cycle (P<0.05) for all LDH-composites. Physico-mechanical properties of the LDH-composites demonstrated similar values to those reported in literature. The solubility and cation release showed a linear increase with LDH loading.

SIGNIFICANCE

LDH-composites repeatedly absorbed/released fluoride and maintained desired physico-mechanical properties. A sustained low-level fluoride release with LDH-composites could lead to a potential breakthrough in preventing early stage carious-lesions.

3D imaging of bean seeds: Correlations between hilum region structures and hydration kinetics

X-ray micro-CT imaging has been applied successfully in food science and seed research due to its capacity to provide very small details of seed traits that are very complex to score. The micropyle and the tissues of the hilum region of bean seeds are recognized as structures which play an important role in hydration process. This latter influences, in turn, not only germination but also the cooking and industrial processing. Nevertheless, the role of each structure of the bean seeds is yet to be fully understood. Moreover such traits are never been quantified by using 3D imaging approaches. In this work, seeds of four ancient Italian landraces of beans have been scanned by X-ray microCT with a twofold approach: bulk scans for whole seed imaging and single seed scans for internal traits measurements. Then water uptake tests have been performed. The different structures composing the hilum region of the beans have been imaged and characterized. The two-dimensional and the three-dimensional morphometric traits have been correlated with parameters of hydration models by Principal Component Analysis (PCA) and Pearson coefficients. Micropyle groove area was the trait most influencing the very initial hydration rates while the hilum groove area was the best correlated with the overall infiltration behavior. The internal free space was the trait best correlated with the moisture at equilibrium. Moreover, strophiole shape resulted the most suitable internal trait for univocal identification of the four landraces. Overall results give a contribution to the understanding of the role of hilum region structures in bean seeds hydration process and show novel morphological traits useful for identification of local bean landraces.

Potential application of titanium dioxide nanoparticles to improve the nutritional quality of coriander (Coriandrum sativum L.)

TiO₂ nanoparticles (nTiO₂) have been widely used in many disciplines. However, whether they can be used to improve crops growth and nutritional quality is unknown. In this study, coriander (Coriandrum sativum L.) was treated with 0, 50, 100, 200, and 400 mg/L nTiO₂ to evaluate their possible benefit to plant growth and nutritional quality under hydroponic conditions. Our observations showed that 50 mg/L nTiO₂ only slightly but insignificantly increased the root and shoot fresh biomass by 13.2 % and 4.1 %, respectively, relative to the control. nTiO₂ at this level promoted shoot K, Ca, Mg, Fe, Mn, Zn, and B accumulation, while spatial distribution of K, Ca, Fe, Mn, Cu and Zn in coriander leaves was not affected. No nTiO₂ internalization or translocation to shoots occurred. 400 mg/L nTiO₂ significantly reduced root fresh biomass by 15.8 % and water content by 6.7 %. Moreover, this high dose induced root cell membrane wrinkling, attributable to their aggregation and adsorption on root surfaces. At 100-400 mg/L, antioxidant defense systems (SOD, CAT and APX) in plant were triggered to alleviate oxidative stress. At an appropriate dose (50 mg/L), nTiO₂ can improve nutrient quality of edible tissues without exerting toxicity to plant or posing health risk to consumers.

High water uptake ability was associated with root aerenchyma formation in rice: Evidence from local ammonium supply under osmotic stress conditions

Root water uptake is strongly influenced by the morphology and anatomical structure of roots, which are regulated by nitrogen forms and environmental stimuli. To further illustrate the roles of different nitrogen forms on root water uptake under osmotic stress, a split-root system was supplied with different nitrogen forms and osmotic stress simulated by adding 10% (w/v) polyethylene glycol (PEG, 6000). The local effects of nitrogen form and osmotic stress on root morphology, anatomical structure, root lignin content, and water uptake rate were investigated. Under osmotic stress conditions, ammonium markedly promoted the formation and elongation of the lateral root, whereas a significant decrease in numbers of lateral roots was observed under local nitrate supply. Under nitrate supply in split-root systems, osmotic stress significantly promoted root cell death and more aerenchyma formation, as well as accelerated the lignification of the root. However, osmotic stress had no negative effect on the root anatomical structure under ammonium supply. The root water uptake rate was significantly higher in split-root supplied with ammonium than nitrate under osmotic stress conditions. In conclusion, the high water uptake ability in local ammonium supply was associated with the more lateral roots development and the lower cell death, aerenchyma formation and lignification under osmotic stress.

Peptide transporter2 (PTR2) enhances water uptake during early seed germination in Arabidopsis thaliana

PTR2 in Arabidopsis thaliana is negatively regulated by ABI4 and plays a key role in water uptake by seeds, ensuring that imbibed seeds proceed to germination. Peptide transporters (PTRs) transport nitrogen-containing substrates in a proton-dependent manner. Among the six PTRs in Arabidopsis thaliana, the physiological role of the tonoplast-localized, seed embryo abundant PTR2 is unknown. In the present study, a molecular physiological analysis of PTR2 was conducted using ptr2 mutants and PTR2CO complementation lines. Compared with the wild type, the ptr2 mutant showed ca. 6 h delay in testa rupture and consequently endosperm rupture because of 17% lower water content and 10% higher free abscisic acid (ABA) content. Constitutive overexpression of the PTR2 gene under the control of the Cauliflower mosaic virus (CaMV) 35S promoter in ptr2 mutants rescued the mutant phenotypes. After cold stratification, a transient increase in ABA INSENSITIVE4 (ABI4) transcript levels during induction of testa rupture was followed by a similar increase in PTR2 transcript levels, which peaked prior to endosperm rupture. The PTR2 promoter region containing multiple CCAC motifs was recognized by ABI4 in electrophoretic mobility shift assays, and PTR2 expression was repressed by 67% in ABI4 overexpression lines compared with the wild type, suggesting that PTR2 is an immediate downstream target of ABI4. Taken together, the results suggest that ABI4-dependent temporal regulation of PTR2 expression may influence water status during seed germination to promote the post-germinative growth of imbibed seeds.

Highly absorbent cellulose nanofibrils aerogels prepared by supercritical drying

In this paper, strictly speaking aerogels of cellulose nanofibrils (CNFs) and TEMPO-oxidized CNFs (TO-CNFs) were obtained from an optimized supercritical drying processes and cryogels were prepared after freeze-drying. The cryogels and aerogels were characterized and the influence of the preparation process on the resulting properties was studied. Significant differences were observed in the micro- and nanoscale organization of the porous structures. In addition, the specific surface areas measured varied from 25 to 160 m² g^-1 for CNF materials, depending on the preparation process. Very high specific surface areas up to 482 m² g^-1 among the highest reported for pure cellulose nanofibrils porous materials were achieved for TO-CNF aerogels. Finally, in order to evaluate their aptitudes for wound dressings applications, the capillary water uptake capacities were assessed on skin mimicking layers. From this study, it was revealed that TO-CNF aerogels can absorb almost 120 times their own weight of water.

Adenine nucleobase directed supramolecular architectures based on ferrimagnetic heptanuclear copper(II) entities and benzenecarboxylate anions

Two planar organic anions, benzoate and benzene-1,4-dicarboxylate (terephthalate), have been selected as potential π-stacking intercalators among ferrimagnetic [Cu₇(μ-adeninato)₆(μ₃-OH)₆(μ-H₂O)₆]²⁺ heptameric discrete entities. The resulting supramolecular architecture is highly dependent on the negative charge density distribution, mainly located in the carboxylate groups of the organic anions. In this sense, the benzoate anion, with just one carboxylate group, does not allow its intercalation between the adeninato ligands as it would imply a high steric hindrance among the heptameric entities. As a consequence, these benzoate anions are located inside the voids of the crystal structure reducing the accessible volume of compound [Cu₇(μ-adeninato)₆(μ₃-OH)₆(μ-H₂O)₆](benzoate)₂·~17H₂O (1). On the contrary, the terephthalate anion, containing two carboxylate groups at opposite sites, adopts a π-stacking sandwich arrangement between two adeninato ligands that affords the porous open structure of formula [Cu₇(μ-adeninato)₆(μ₃-OH)₆(μ-H₂O)₆](terephthalate)·nH₂O (2a, 2b; n: 12 and 24, respectively). In addition to that, the less directional nature of the π-stacking interactions in comparison to the complementary hydrogen bonding based supramolecular metal-organic frameworks (SMOFs), suits them with a flexible architecture able to reversibly adsorb/desorb water (up to a 25-30% at 20 °C) altogether with the expansion/shrinkage of the crystal structure. The bridging adeninato and hydroxido ligands are effective magnetic exchange mediators to provide a S_T = 5/2 ferrimagnetic state for the heptanuclear entity.

Low-dose (S)TEM elemental analysis of water and oxygen uptake in beam sensitive materials

The performance stability of organic photovoltaics (OPVs) is largely determined by their nanoscale morphology and composition and is highly dependent on the interaction with oxygen and water from air. Low-dose cryo-(S)TEM techniques, in combination with OPV donor-acceptor model systems, can be used to assess oxygen- and water-uptake in the donor, acceptor and their interface. By determining a materials dependent critical electron dose from the decay of the oxygen K-edge intensity in Electron Energy Loss Spectra, we reliably measured oxygen- and water-uptake minimizing and correcting electron beam effects. With measurements below the dose limit the capability of STEM-EDX, EFTEM and STEM-EELS techniques are compared to qualitatively and quantitatively measure oxygen and water uptake in these OPV model systems. Here we demonstrate that oxygen and water is mainly taken up in acceptor-rich regions, and that specific oxygen uptake at the donor-acceptor interphase does not occur. STEM-EELS is shown to be the best suitable technique, enabling quantification of the local oxygen concentration in OPV model systems.

The proton conductivity and mechanical properties of Nafion®/ ZrP nanocomposite membrane

Zirconium phosphates (ZrP) were incorporated into Nafion® 117 membrane by impregnating method to obtain a reduced methanol permeation and improved proton conductivity for fuel cell application. The mechanical properties and water uptake of Nafion® membrane incorporated with zirconium phosphates nanoparticles was more improvement when compared to the commercial Nafion® 117, due to the presence of phosphoric acid within the nanoparticles. The effect of ZrP nano filler on the membrane structural morphology and thermal properties were investigated by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Thermal gravimetric analysis (TGA) and Scanning Electron Microscopy (SEM). The improved ion conductivity and decreased methanol permeability on the nanocomposite membranes showed a great potential for fuel cell applications. The nanocomposite membrane with high tensile strength was obtained due to the well dispersed zirconium phosphates within the Nafion® matrix.

Does phenology play a role in the feedbacks underlying shrub encroachment?

Shrub encroachment has emerged as a global phenomenon over the past century. Multiple drivers have been put forward to explain the increased shrub dominance in various ecosystems around the world. However, the potential role of phenology in regulating shrub encroachment is not well understood. We address this issue using 3-year continuous monitoring of the phenology of coexisting shrubs and grasses combined with observations of ecohydrological processes (water uptake) and soil conditions (root zone soil moisture, soil texture, and soil temperature) at four study sites in Inner Mongolia, China, with shrub coverage of Caragana microphylla ranging from 0%, to 6.8%, 26.8% and 34.2%. Along such an encroachment gradient, shrubs exhibited progressively earlier onsets and later ends of the growing season, with an overall extension in growing season length by 15 days to 22 days in the later stages of shrub encroachment. Conversely, the coexisting grasses showed earlier occurrences both in spring and autumn phenological phases, which resulted in a phenological gap between shrubs and grasses. Thus, a positive feedback could exist between these phenological changes and shrub encroachment. In shrub patches, soils were wetter, with finer texture, and with more suitable temperatures for plant survival and development, which favored the lengthening of growing season of shrubs. The longer growing seasons are associated with longer periods of water use and photosynthesis for shrubs, and better opportunities for water uptake, with the overall effect of facilitating shrub growth and further expansion.

Chemical reaction between sodium pyruvate and ammonium sulfate in aerosol particles and resultant sodium sulfate efflorescence

The hygroscopicity of aerosols is dependent upon their chemical composition. When their chemical compositions are altered, the water content in aerosols often changes, which may further modify phase behaviour. However, the study of phase behaviour dependence on chemical reactions is still limited. In this work, internally mixed sodium pyruvate (SP)/ammonium sulfate (AS) droplets were studied using an in-situ ATR-FTIR spectrometer. FTIR spectral analysis showed that solid sodium sulfate (SS) formed during the dehydration process, indicating a chemical reaction between SP and AS. In addition, the water content decreased after a dehydration-hydration process despite organic salt (SS) to inorganic salt (AS) mole ratios (OIRs) During the second relative humidity (RH) cycle, the water content remained constant, however, the efflorescence relative humidity (ERH) was lower than that in the first dehydration. The crystal relative humidities (CRHs) of SS are 66.7-53.1%, 66.0-58.2%, 62.2-57.1% and 49.6-43.6% for OIRs of 3:1, 2:1, 1:1 and 1:3, respectively, suggesting the crystallization of SS was favoured by higher SP content. For 2:1 OIRs, the solid SS was the greatest and an excess of either SP or AS blocked the solid SS formation. At a constant 80% RH, depletion of reagents was ∼0.97, and water loss was ∼0.6 in ∼40 min. After 90 min, solid SS formed. The chemical reaction was faster than water loss; furthermore, water loss from the chemical reaction led to solid SS above the ERH of pure SS particles (∼75% RH). When the RH changed rapidly, the reaction was slow and solid SS decreased.

Flexible heteroionic calcium-magnesium alginate beads for controlled drug release

In the present work heteroionic calcium-magnesium alginate beads have been prepared by ionotropic gelation using different Ca:Mg ratios. This simple and straightforward approach allowed the obtention of CaMg-alginate beads presenting different mechanical performance depending on the Mg:Ca ratio. The dynamic swelling behavior of the beads was investigated. Increase in the quantity of Mg²⁺ incorporated in the beads increased the rate of swelling at pH 1.2 and pH 7.2. Finally, the release of ibuprofen was investigated. It was found that increasing the Mg²⁺ present in the beads raised the drug release rate.

Aboveground overyielding in a mixed temperate forest is not explained by belowground processes

The relationship between forest productivity and tree species diversity has been described in detail, but the underlying processes have yet to be identified. One important issue is to understand which processes are at the origin of observed aboveground overyielding in some mixed forests. We used a beech-maple plantation exhibiting aboveground overyielding to test whether belowground processes could explain this pattern. Soil cores were collected to determine fine root (FR) biomass and vertical distribution. Correlograms were used to detect spatial arrangement. Near-infrared reflectance spectroscopy was used to identify the tree species proportion in the FR samples and spatial root segregation. An isotopic approach was used to identify water acquisition patterns. The structure and the composition of the ectomycorrhizal fungal community were determined by high-throughput sequencing of DNA in the soil samples. We found no spatial pattern for FR biomass or for its vertical distribution along the gradients. No vertical root segregation was found, as FR density for both species decreased with depth in a similar way. The two species displayed similar vertical water acquisition profiles as well, mainly absorbing water from shallow soil layers; hence, niche differentiation for water acquisition was not highlighted here. Significant alterations in the fungal community compositions were detected in function of the percentage of maple in the vicinity of beech. Our findings do not support the commonly suggested drivers of aboveground overyielding in species-diverse forests and suggest that competition reduction or between-species facilitation of belowground resource acquisition may not explain the observed aboveground overyielding.

Carbohydrate gel beads as model probes for quantifying non-ionic and ionic contributions behind the swelling of delignified plant fibers

Macroscopic beads of water-based gels consisting of uncharged and partially charged β-(1,4)-d-glucan polymers were developed to be used as a novel model material for studying the water induced swelling of the delignified plant fiber walls. The gel beads were prepared by drop-wise precipitation of solutions of dissolving grade fibers carboxymethylated to different degrees. The internal structure was analyzed using Solid State Cross-Polarization Magic Angle Spinning Carbon-13 Nuclear Magnetic Resonance and Small Angle X-ray Scattering showing that the internal structure could be considered a homogeneous, non-crystalline and molecularly dispersed polymer network. When beads with different charge densities were equilibrated with aqueous solutions of different ionic strengths and/or pH, the change in water uptake followed the trends expected for weak polyelectrolyte gels and the trends found for cellulose-rich fibers. When dried and subsequently immersed in water the beads also showed an irreversible loss of swelling depending on the charge and type of counter-ion which is commonly also found for cellulose-rich fibers. Taken all these results together it is clear that the model cellulose-based beads constitute an excellent tool for studying the fundamentals of swelling of cellulose rich plant fibers, aiding in the elucidation of the different molecular and supramolecular contributions to the swelling.

Cutaneous water collection by a moisture-harvesting lizard, the thorny devil (Moloch horridus)

Moisture-harvesting lizards, such as the Australian thorny devil, Moloch horridus, have the remarkable ability to inhabit arid regions. Special skin structures, comprising a micro-structured surface with capillary channels in between imbricate overlapping scales, enable the lizard to collect water by capillarity and transport it to the mouth for ingestion. The ecological role of this mechanism is the acquisition of water from various possible sources such as rainfall, puddles, dew, condensation on the skin, or absorption from moist sand, and we evaluate here the potential of these various sources for water uptake by M. horridus The water volume required to fill the skin capillary system is 3.19% of body mass. Thorny devils standing in water can fill their capillary system and then drink from this water, at approximately 0.7 µl per jaw movement. Thorny devils standing on nearly saturated moist sand could only fill the capillary channels to 59% of their capacity, and did not drink. However, placing moist sand on skin replicas showed that the capillary channels could be filled from moist sand when assisted by gravity, suggesting that their field behaviour of shovelling moist sand onto the dorsal skin might fill the capillary channels and enable drinking. Condensation facilitated by thermal disequilibrium between a cool thorny devil and warm moist air provided skin capillary filling to approximately 0.22% of body weight, which was insufficient for drinking. Our results suggest that rain and moist sand seem to be ecologically likely water sources for M. horridus on a regular basis.

The role of peltate scales in desiccation tolerance of Pleopeltis polypodioides

The extreme drought tolerance of the resurrection fern is in part the result of the dorsal scales that assist in water distribution and controlled desiccation. We studied the effect of peltate scales on water uptake and loss of the desiccation-tolerant epiphytic fern Pleopeltis polypodioides using optical and FTIR microscopy and staining with calcofluor, solophenyl flavine7GFE, and Ruthenium Red. We provide information on structure, property, and function of the scales by measuring water uptake and dehydration, contact angles, and metabolic activity. Peltate scales mainly contain cellulose, xylogalactans, and pectin. Water is absorbed from the center of scales, and the overlapping arrangement of scales facilitates surface spreading of water. Intact fronds hydrated fully within 5 h of imbibition of the apical pinna, without scales water uptake stopped after 1 h. Hydration rates via rhizomes followed a longer time course but also improved in the presence of scales. Fronds with and without scales lost half of their water content in 15 or 4 h, respectively. The overall metabolism of rapidly dehydrated fronds was significantly reduced compared with slowly dehydrated fronds. Thus, water management and metabolism of Pleopeltis are dependent on surface properties determined by peltate scales.

The effect of instrument lubricant on the diametral tensile strength and water uptake of posterior composite restorative material

OBJECTIVES

This in-vitro study investigated the effect of 'instrument lubricants' used during placement of composite restorative material, on the diametral tensile strength (DTS) and water uptake of composite specimens.

METHODS

300 posterior composite cylindrical specimens were manufactured: 60 with each instrument lubricant (ethanol, 3-step, 2-step and 1-step 'bonding agent') and 60 with no lubricant (controls). Each set of 60 specimens was evenly allocated to one of the following test groups (n=100/group): Group 1 - tested for DTS immediately after manufacture; Groups 2 and 3 - tested for DTS after immersion in phosphate-buffered saline (PBS) for 1 and 12-weeks respectively, using a Universal Instron machine. Water uptake was assessed gravimetrically. Data were statistically analysed with two-way ANOVA and Tukey's post hoc test (α=0.05).

RESULTS

The mean DTS and percentage weight change of composite specimens ranged between 32.49-53.14MPa and 0.51-1.36% and varied with lubricant used and time incubated in PBS. All control groups exhibited significantly higher DTS (MPa) (groups 1-3: 53.17±1.78; 50.64±1.85; 45.17±1.77) and lower percentage weight change (groups 2-3: 0.51±0.03; 0.61±0.01) than specimens placed with an instrument lubricant, with significant differences between certain lubricant groups.

CONCLUSION

Data from the present study suggest that the use of instrument lubricant may adversely effect the DTS and water uptake of composite restorative material.

CLINICAL SIGNIFICANCE

The use of instrument lubricants to aid composite placement is widespread however based on the data obtained it is suggested that discontinuing or limiting the use of instrument lubricants, and if necessary using the 'bonding agent' from a 3-step adhesive system is recommended as results suggest this has the least deleterious effect upon material properties.​.

The effects of groundwater depth on water uptake of Populus euphratica and Tamarix ramosissima in the hyperarid region of Northwestern China

Knowledge of the water sources used by desert trees and shrubs is critical for understanding how they function and respond to groundwater decline and predicting the influence of water table changes on riparian plants. In this paper, we test whether increased depth to groundwater changed the water uptake pattern of desert riparian species and whether competition for water resources between trees and shrubs became more intense with a groundwater depth gradient. The water sources used by plants were calculated using the IsoSource model, and the results suggested differences in water uptake patterns with varying groundwater depths. At the river bank (groundwater depth = 1.8 m), Populus euphratica and Tamarix ramosissima both used a mixture of river water, groundwater, and deeper soil water (>75 cm). When groundwater depth was 3.8 m, trees and shrubs both depended predominantly on soil water stored at 150-375 cm depth. When the groundwater depth was 7.2 m, plant species switched to predominantly use both groundwater and deeper soil water (>375 cm). However, differences in water acquisition patterns between species were not found. The proportional similarity index (PSI) of proportional contribution to water uptake of different water resources between P. euphratica and T. ramosissima was calculated, and results showed that there was intense water resource competition between P. euphratica and T. ramosissima when grown at shallow groundwater depth (not more than 3.8 m), and the competition weakened when the groundwater depth increased to 7.2 m.

Time Harmonic Elastography Reveals Sensitivity of Liver Stiffness to Water Ingestion

The aim of the study was to test the sensitivity of liver stiffness (LS) measured by time harmonic elastography in large tissue windows to water uptake and post-prandial effects. Each subject gave written informed consent to participate in this institutional review board-approved prospective study. LS was measured by time harmonic elastography in 10 healthy volunteers pre- and post-prandially, as well as before, directly after and 2 h after drinking water. The LS-time function during water intake was measured in 14 scans over 3 h in five volunteers. LS increased by 10% (p = 0.0015) post-prandially and by 11% (p = 0.0024) after pure water ingestion, and decreased to normal values after 2 h. LS was lower after overnight fasting than after 2-h fasting (3%, p = 0.04). Over the time course, LS increased to post-water peak values 15 min after drinking 0.25 L water and remained unaffected by further ingestion of water. In conclusion, our study indicates that LS measured by time harmonic elastography represents an effective-medium property sensitive to physiologic changes in vascular load of the liver.

Development of experimental resin modified glass ionomer cements (RMGICs) with reduced water uptake and dimensional change

OBJECTIVE

To investigate water uptake, desorption, diffusion coefficient, solubility and dimensional changes of four experimental RMGICs in deionized water (DW) and artificial saliva (AS), and compare with two commercial RMGICs and control home liquids based on the two commercial materials used.

METHODS

Two commercial RMGICs, RelyX Luting (RX, 3M ESPE) and Fuji Plus (FP, GC), two control home liquids and four new liquid compositions (F1, F2, R1, R2) comprising different percentages of the monomer THFM (tetrahydrofurfuryl-methacrylate) with the original monomer HEMA (2-hydroxyethyl-methacrylate) were used in this study. Home and experimental liquids were mixed with the corresponding commercial powder. Disk-shaped specimens (16mm diameter 1mm thickness) were immersed in DW/AS at 37°C (n=6) and weighed at regular time intervals. Percentage weight change with time was recorded. At 24 weeks, disks were desorbed in an oven at 37°C to minimum weight.

RESULTS

All new compositions showed lower water uptake and dimensional (volume) changes than the commercial products in both DW and AS. On desorption, FP showed higher weight loss compared to materials in the same group in both solutions (p<0.0001), with the exception of F2 in DW (p=0.283). RX had higher weight loss compared to R1 and R2 in DW and AS (p<0.0001). Fickian diffusion was confirmed for all materials immersed in DW and AS.

SIGNIFICANCE

The experimental compositions in this study have shown promising results when tested in both DW and AS with lower water uptakes and volume changes than commercial materials. This may lead to wider applications than current commercial materials.

Biomedical potential of chitosan/HA and chitosan/β-1,3-glucan/HA biomaterials as scaffolds for bone regeneration--A comparative study

The aim of this work was to compare biomedical potential of chitosan/hydroxyapatite (chit/HA) and novel chitosan/β-1,3-glucan/hydroxyapatite (chit/glu/HA) materials as scaffolds for bone regeneration via characterization of their biocompatibility, porosity, mechanical properties, and water uptake behaviour. Biocompatibility of the scaffolds was assessed in direct-contact with the materials using normal human foetal osteoblast cell line. Cytotoxicity and osteoblast proliferation rate were evaluated. Porosity was assessed using computed microtomography analysis and mechanical properties were determined by compression testing. Obtained results demonstrated that chit/HA scaffold possessed significantly better mechanical properties (compressive strength: 1.23 MPa, Young's modulus: 0.46 MPa) than chit/glu/HA material (compressive strength: 0.26 MPa, Young's modulus: 0.25 MPa). However, addition of bacterial β-1,3-glucan to the chit/HA scaffold improved its flexibility and porosity. Moreover, chit/glu/HA scaffold revealed significantly higher water uptake capability (52.6% after 24h of soaking) compared to the chit/HA (30.7%) and thus can serve as a very good drug delivery carrier. Chit/glu/HA scaffold was also more favourable to osteoblast survival (near 100% viability after 24-h culture), proliferation, and spreading compared to the chit/HA (63% viability). The chit/glu/HA possesses better biomedical potential than chit/HA scaffold. Nevertheless, poor mechanical properties of the chit/glu/HA limit its application to non-load bearing implantation area.

In situ study of water uptake by the seeds, endosperm and husk of barley using infrared spectroscopy

Variations in the amount and rates of water uptake influence the seed hydration as well as the modification of the endosperm for industrial uses (e.g., malting). The aim of this study was to investigate and interpret absorption frequencies in the mid infrared (MIR) region associated with water uptake in whole seeds, husk and endosperm of barley seeds during the initial period of soaking in water. Partial least squares (PLS) regression models for the prediction of water uptake in the set of samples yield a coefficient of determination (R(2)) and a standard error in cross validation of 0.75 and 2.57 (% w/w), respectively. The biological implications of this study are that the first stages of germination can be monitored using the information derived from the MIR spectra. These results also demonstrated that whole seeds, endosperm and husk derived from the same variety or genotype have different patterns in the MIR region.

Storage influence on the functional, sensory and keeping quality of quality protein maize flour

Apart from nutritional values functional and sensory properties affect the behavior of food system and its acceptability for consumption during storage. Hence keeping quality of maize flour (HQPM-7) with and without lime treatment(control) was studied in terms of functional (bulk density, pH, swelling capacity, water and oil absorption capacity, least gelation concentration, peroxide value), sensory (appearance, color, taste, texture, mouth feel and overall acceptability) and rolling parameters (water absorption by flour, rolling quality, diameter after baking ) for a period of 6 months under room temperature (25 ± 5 °C) in two types of packages viz, LDPE cover (P) and plastic box (B). Physical parameters such as length, breadth and thickness (11.26-10.52 mm, 9.67-9.14 mm, & 4.72-3.95 mm) were reduced in lime treated grains compared to control. Significant increase (p ≤ 0.05) in ash content of lime treated flour (1.67 ± 0.01 g) was observed compared to control (1.5 ± 0.02 g). Calcium content of lime treated maize flour increased significantly (p ≤ 0.05) from 48 to 136 mg. There is a significant reduction in functional properties of flour after 3 and 2 months irrespective in polyethylene cover and plastic box. The properties like rolling quality, diameter after baking and water uptake by the flour were reduced significantly (p ≤ 0.05) after 4 months of storage in treated and after 1 month in control samples. Sensory scores of roti (dry pan cake) decreased significantly after 3 months of storage with an overall acceptability score of 4.0 and 3.4. In control samples mean taste (3.6), mouth feel (3.8) as well as OAA scores (3.8) decreased after second month. Hence lime treated maize flour with added nutritional benefits is suitable for making rotis of good palatability and can be stored in LDPE covers up to 3 months.

Relationship of starch changes to puffing expansion of parboiled rice

'Intan' variety of paddy (Oryza sativa) was tested for puffing. It was parboiled under a wide range of paddy moisture content, steaming pressure and time, as also temperature and time of sand heating. The resulting milled rices were studied for their diverse properties including puffing. Indices of starch changes in the samples were calculated as: (1) gelatinisation index from the solubility of amylose in 0.2 N KOH; (2) amylopectin retrogradation from the post-production drop in room-temperature hydration power of the parboiled paddy during air-drying, (3) thermal breakdown of starch from the drop in gel permeation chromatographic fraction I of starch; lipid-amylose complexation indirectly from (4) drop in rate of water uptake during cooking and (5) cooked-rice firmness. It was found that the puffing expansion was very highly correlated with the combined above 5 indices of starch changes, as much as 90% of the variation in puffing being explainable on that basis. Puffing was promoted by gelatinisation as well as lipid-amylose complexation, but was retarded by amylopectin retrogradation and probably starch breakdown.

Water uptake by safflower and wheat roots infected with arbuscular mycorrhizal fungi

The objective of this study was to determine if infection by arbuscular mycorrhizal fungi alters water uptake by roots under well watered to severely droughted conditions. Safflower and wheat plants were grown with and without the mycorrhizal fungi, Glomus etunicatum or G. intraradices in nutrient-amended soil under environmentally controlled conditions to yield mycorrhizal and non-mycorrhizal plants with similar leaf areas, root length densities, d. wt, and adequate tissue phosphorus and nitrogen. Specific water uptake rates (cm₃ of water cm_-1 root length d^-1 ) were estimated non-destructively at various depths in the soil from changes in the soil water content measured using a gamma attenuation method. When soil water was severely depleted, changes in soil water potentials were also measured with soil psychrometers. Roots from both plant species extracted water at the fastest rate from the upper soil layers when the soil water content was high, and later, extracted water primarily from deeper depths as water in the upper soil layers was depleted. Mycorrhizal infection did not affect the rates at which roots extracted water from soil whether soil moisture conditions were at their wettest condition, at container capacity, or at the driest extreme when soil water potentials ranged from -1.5 to -2.0 MPa and the plants were completely wilted. Plant water relations were also largely unaffected by infection. Mycorrhizal infection did not alter the ability of plants to extract water from soil even during extreme drought.

Comparative study of water uptake and photosynthetic gas exchange between scrub and fringe red mangroves, Rhizophora mangle L

The red mangrove (Rhizophora mangle L.) occurs frequently in both scrub and fringe mangrove forests. Our previous study demonstrated that individuals of this mangrove species growing in scrub and fringe forests differ significantly in both morphological and physiological characteristics. To further characterize physiological differences between scrub and fringe mangroves, we compared their differences in water uptake and photosynthetic gas exchange during different seasons. In the wet season (June-October, 1990), scrub mangroves showed lower δD and δ¹⁸O values of stem water than fringe mangroves, indicating more usage of rain-derived freshwater. In the dry season (Jan-April, 1991), however, scrub mangroves utilized the same water source as fringe mangroves, reflected by their similar δD and δ¹⁸O values of stem water. Consistently, there were significant differences in predawn water potentials between scrub and fringe mangroves in the wet season (October 1990) with higher values for scrub mangroves, but no significant differences in the dry season (January 1991). Higher elevation in the scrub forest seems to be the major factor responsible for the shift of water sources in scrub mangroves. On Apr. 27 and Aug. 8, 1990, scrub mangroves showed lower CO₂ assimilation rate, stomatal conductance, and intercellular CO₂ concentration than fringe mangroves. There were no differences in these gas exchange characteristics on the other two measuring dates: Oct. 17, 1990 and Jan. 11, 1991. Instantaneous water use efficiency was significantly higher for scrub mangroves than for fringe mangroves on three of the four sampling dates. Similarly, leaf carbon isotope discrimination of scrub mangroves was always significantly lower than that of fringe mangroves, indicating higher long-term water use efficiency. Higher water use efficiency in scrub mangroves is a result of stomatal limitation on photosynthesis, which may entail considerable carbon cost to the plants.