Dry Mass Loss Research Articles

Dry mass loss of different moisture content canola at different temperatures

Dry mass loss (DML) of Sound canola and Mouldy canola (sound + mouldy canola) was measured at 25, 30, and 35oC over 14 weeks by weighing 10 kg samples every 2 week. The moisture content of the canola was 10, 12.5, and 15.0% (wet basis). The relationship was quantified among the DML measured gravimetrically, germination decrease rate (GDR), and decrease in the percentage of test weight (PTW). The measured DML was also compared with the DML estimated from respired CO2. The measured DML increased as germination and test weight decreased, and the Spearmen Rank Order correlation between DML and germination or between DML and PTW was greater than 0.58 in 18 of 24 cases. The GDR of mouldy canola was significantly higher than that of Sound canola except at 15% moisture content and 35oC. A decrease of germination and/or PTW could be used to estimate roughly the DML trend but did not predict the DML value with high accuracy. There was no significant difference between the measured- and estimated-DML. Measuring the mass loss or CO2 production roughly estimated DML but using DML to evaluate grain quality was unreliable.

Dweller and tunneler dung beetles synergistically accelerate decomposition of cattle and horse dung in a semi-arid steppe

Aboveground and belowground invertebrates play a key role in decomposition of organic matter in terrestrial ecosystems. Dung beetles are well known for their functions in breaking down and transporting ungulate dung into soils thus promoting dung decomposition. However, the effects of functionally different dung beetles on the decomposition processes of the dung from different ungulates remain less explored. We did an in situ experiment using the 'dung and soil' mesocosm to investigate the separate and combined effects of two functionally contrasting dung beetle species, a dweller Aphodius sordecens and a tunneler Onthophagus gibbulus, on the decomposition processes of the dung from horse and cattle. We determined the changes in dung mass, dung C and N contents, microbial respiration from the 'dung and soil' mesocosm or from the soil beneath the dung pats, and examined the amount of dung balls transferred by beetles into different soil layers, under five dung beetle treatments (C – soil, no dung nor beetles; D – dung on soil with no beetles; DB - dung on soil with dweller beetles; TB - dung on soil with tunneler beetles; DTB - dung on soil with dweller and tunneler beetles) were applied to the dung of two major grazers with different digestive systems in native steppes in northern China, over a two-month period following dung deposition. We found that (1) tunneler beetles (in TB and DTB) significantly enhanced the dry mass loss of cattle dung but not horse dung. (2) Dung C and N contents declined more rapidly with the presence of any dung beetle species (DB-DTB) than that without (D); and dung N content showed different decreasing rates between horse and cattle dung in different decomposition periods. (3) The presence of the two functionally contrasting dung beetle species together had a synergistic, positive effect on soil microbial respiration and thus on the decomposition rate of soil organic matter; however, no significant effects of beetles on net microbial respiration was detected in the 'dung + soil' mesocosm. (4) The direct effect of dung beetles on dung mass loss was stronger for cattle dung than for horse dung. In contrast, the decline in moisture content of horse dung with decomposition time affected the microbial respiration in dung, and thus indirectly affected the dry mass loss and the C and N contents. Our results suggest it critically important to incorporate the functions of soil invertebrates into nutrient cycling models to improve their accuracy, and to promote invertebrate diversity in grazed grassland to maintain ecosystem health and services.

Effects of gamma radiation on the quality of Hass avocado fruits (Persea americana Mill.)

The Hass avocado is a crop with significant growth potential for Colombia as an export product; however, the country has reported quarantine-type pest insect species that limit its export. The objective of this research was to evaluate gamma radiation treatments of fruit in order to study its use as a post-harvest treatment. Gamma radiation levels were evaluated at 100, 200, 400 and 800 Gy and compared against a control without irradiation. The harvest maturity status was established as a blocking factor. The evaluation was carried out for 20 days after the application of the treatments, emulating conditions of refrigerated transport at 7 °C. The variables firmness, exocarp and mesocarp color, soluble solids, dry mass, respiration, and weight loss were analyzed longitudinally at five evaluation points, where time acted as an intrasubject factor in the analysis of longitudinal multivariate variance. The variables lipid peroxidation and ethylene production rate were evaluated only once at the end of the test. We found that the highest radiation treatment affected the color of the exocarp and the content of total soluble solids, while all treatments affected the respiratory intensity, increased lipid peroxidation, altering the color of the mesocarp, which is the tissue of greater commercial interest for fresh fruits. All the treatments affected the visual quality of the fruits independent of the point of harvest maturity.

Injection-molded capsule bodies and caps based on polymer blends for controlled drug delivery

A variety of polymer:polymer blends was used to prepare hot melt extrudates and empty capsules (bodies and caps) by injection-molding using a benchtop extruder (Babyplast). KollidonSR:inulin and Carbothane:inulin blends were investigated. The impact of the blend ratio on the water uptake and dry mass loss kinetics upon exposure to 0.1 MHCl, phosphate buffer pH6.8 and culture medium optionally inoculated with fecal samples from Inflammatory Bowel Disease (IBD) patients were studied. Hot melt extrudates were loaded with up to 60% theophylline, capsules were filled with drug powder. Increasing the inulin content led to increased water uptake and dry mass loss rates, resulting in accelerated drug release from the dosage forms, irrespective of the type of polymer blend. This can be attributed to the higher hydrophilicity/water-solubility of this polymer compared to KollidonSR and Carbothane. Interestingly, the presence of fecal samples in culture medium increased the water uptake and dry mass loss of hot melt extrudates to a certain extent, suggesting partial system degradation by bacterial enzymes. However, these phenomena did not translate into any noteworthy impact of the presence of colonic bacteria on theophylline release from the investigated extrudates or capsules. Hence, drug release can be expected to be independent of the location “small intestine vs. colon” from these dosage forms, which can be advantageous for long term release throughout the entire gastro intestinal tract.

Effects of model boundary conditions on simulated drying kinetics and inversely determined liquid water permeability for cement-based materials

The accurate simulation of moisture transport in cement-based materials is an important step to predict many durability processes of concrete structures. This paper studied the effects of boundary conditions on modeling moisture transport, in particular for simulating drying kinetics and the inverse determination of liquid water permeability. Three boundary conditions were investigated, namely, the Dirichlet (imposed) condition, the flux boundary condition, and the boundary supplied by moisture movement in the ambient environment (coupling with a convection-diffusion moisture transport model). By comparing with the measured drying mass loss curves (without airflow) for ordinary Portland cement pastes, we found that the Dirichlet boundary condition provides slightly better simulated drying kinetics than the flux boundary condition, while results of the coupling model are less promising. As for inversely determined liquid permeability, the studied boundary conditions lead to the max. 36% difference. If considering the airflow in the environment, both the flux boundary condition and the coupling model with computational fluid dynamics (CFD) show that the airflow does not have an effect on moisture evaporation for the studied cement-based materials, because of their low permeability, resulting in a very short initial stage of drying. Moisture evaporation for these materials is mainly controlled by the internal moisture transport. However, for materials with high permeability, the drying kinetics increase with the airflow velocity because the initial stage of drying becomes much longer than the low permeable materials. The implication is that some laboratory methods for drying cement-based materials (specimens stored in a sealed chamber without airflow) may need to be reevaluated because the relative humidity at the material surface is different from the controlled relative humidity.

Significant difference in response of malignant tumor cells of individual patients to photodynamic treatment as revealed by digital holographic microscopy.

The investigation of in-vitro response of cell cultures derived from tumor material of individual patients with similar tumor localizations to photodynamic treatment is presented. Tumor types included in the research were renal cell carcinoma, melanoma and alveolar, synovial, lypo- and osteo- sarcomas. Long-term observations of treatment-induced morphological changes in cells were performed by means of digital holographic microscopy. A substantial variance in response of cells of individual patients with similar tumor types and localizations to photodynamic treatment with the same dose has been observed. These peculiarities are indicative of the demand to personalized protocols of photodynamic treatment. The elevated resistance of cells of some patients to treatment at high doses highlights potential limitations of photodynamic therapy for some patients. Digital holographic microscopy is shown to be an informative label-free noninvasive tool allowing for long-term monitoring of cell samples in vitro and providing quantitative information on necrosis rate and loss of cellular dry mass. The developed methodology can be generalized for analysis of cellular response to various therapies.

In vitro evaluation of the anti-proteolytic and cross-linking effect of mussel-inspired monomer on the demineralized dentin matrix

ObjectivesTo evaluate the anti-proteolytic and cross-linking effect of N-(3,4-dihydroxyphenethyl)methacrylamide (DMA) on the demineralized dentin matrix in vitro. MethodsFour experimental solutions were selected: 50% ethanol/water solution (Control); 1, 5, and 10 mmol/L DMA dissolved in 50% ethanol/water solution. Sound human molars were sectioned to produce dentin beams with dimension of 1×1×6 mm. The dentin beams were demineralized with 10% phosphoric acid for 8 h to remove the apatite. The demineralized specimens were randomly separated into four groups and immersed in the four experimental solutions for 1 h. After the treatment, the ultimate tensile strength (UTS), loss of dry mass and the release of hydroxyproline by storing the treated specimens in 0.1 mg/mL collagenase solution for 24 h were assessed. The swelling ratio of another ten specimens from each group were evaluated. The interaction between DMA with dentin matrix was observed under Field Emission Scanning Electron Microscopy (FESEM). UTS data was analyzed by two-way ANOVA followed by Tukey test, and the other data was analyzed by one-way ANOVA followed by Tukey test (α = 0.05). ResultsThe two-way ANOVA factors, different solutions (p < 0.001), collagenase degradation (p < 0.001) and their interactions (p < 0.001) all significantly affected the UTS. The 10 mM DMA treatment significantly decreased the percentage of loss of dry mass, release of hydroxyproline and swelling ratio of demineralized dentin matrix compared to other treatment groups (p < 0.05). The FESEM observation depicted that with increasing concentration of DMA, the structure of dentin matrix was protected and the porosity within dentin collagen network was decreased. ConclusionsThe treatment by 10 mM DMA/ethanol solution for 1 hour is capable of enhancing the mechanical properties of demineralized dentin matrix against collagenase degradation and may be clinically useful to improve the durability of hybrid layer. Clinical SignificanceThe 10 mM DMA/ethanol primer may offer an alternative choice for dentists to strengthen the mechanical properties of demineralized dentin matrix and resist its degradation by collagenase.

Ecological implications of twentieth century reforestation programs for the urban forests of S\xe3o Paulo, Brazil: a study based on litterfall and nutrient cycling

The focus of this study was to investigate the wide use of Eucalyptus spp., an exotic plant with high allelopathic ability, in the reforestation programs of urban parks in São Paulo City, Brazil, over the last century. To understand the implications of using Eucalyptus spp. in the city’s parks, this study aimed to compare nutrient cycling and litter decomposition between a mixed composition of litter (i.e., native and exotic species) and the litter of a single species (i.e., Eucalyptus). To accomplish this, newly deciduous leaves were collected from two native and two exotic species that are commonly used in the afforestation of São Paulo as well as from Eucalyptus spp. The mixed composition of litter yielded a higher dry mass loss and return of macro- and micronutrients to the forest floor. The decomposition constant (k) values were 0.00322 and 0.00207 g g−1 day−1 for the mixed composition and Eucalyptus spp., respectively. The time required for decomposition of 50 and 95% of deciduous material was 215 and 931 days, respectively, and for the mixed litterfall 334 and 1449 days, respectively, for Eucalyptus spp. Therefore, the mixed litter exhibited greater dry mass loss and nutrient cycling in an urban forest of São Paulo City, since dry mass losses as well as speed and amount of nutrients returned to the forest floor were relatively higher compared to Eucalyptus spp. Nutrient cycling via Eucalyptus spp. litter was less efficient than mixed composition of litter, demonstrating that reforestation programs carried out in the twentieth century using only one species may have had little success. The results of this work emphasize the fact that in urban reforestation programs the City of São Paulo must consider the environmental and biogeographic characteristics of the species employed and use high levels of biodiversity, since the city lies in a megadiverse biome.

Macronutrient deficiency in cucumber plants: impacts in nutrition, growth and symptoms

This study aimed to assess the growth, nutrition and visual deficiency symptoms of cucumber plants as a function of macronutrient omission. The experiment was conducted in a completely randomized design, with seven treatments and four replicates, corresponding to nutrient solution without nutrient omission (CS) of Hoagland and Arnon, nitrogen (−N), phosphorus (−P), potassium (−K), calcium (−Ca), magnesium (−Mg) and sulfur (−S) omission. Omissions decreased the accumulation of macronutrients with detrimental effects in physiological variables and in the efficiency of absorption, transport and use of macronutrients, causing losses in growth and on dry mass production. Since the losses in dry mass in the shoot were up to 85%, 85%, 83%, 47%, 40% and 40% to the omission of Ca, Mg, N, P, K and S, respectively. The accumulation of macronutrients in the aerial part of cucumber plants that received the complete solution (CS) in relation to each omission (−) was 1058/75, 157/20, 958/152, 578/9, 147/5 and 142/12 for CSN/−NN, SCP/−PP, SCK/−KK, SCCa/−CaCa, SCMg/−MgMg and SCS/−SS, respectively. Therefore, the lowest macronutrients accumulation, the green color index, plant growth and dry matter production were reduced in cucumber plants. The order of limitation of macronutrients in the shoot dry matter production in cucumber plants was N = Ca = Mg > P > K = S.

The pursuit of resin-dentin bond durability: Simultaneous enhancement of collagen structure and polymer network formation in hybrid layers

ObjectiveImperfect polymer formation as well as collagen’s susceptibility to enzymatic degradation increase the vulnerability of hybrid layers over time. This study investigated the effect of new dimethyl sulfoxide (DMSO)-containing pretreatments on long-term bond strength, hybrid layer quality, monomer conversion and collagen structure. MethodsH3PO4-etched mid-coronal dentin surfaces from extracted human molars (n = 8) were randomly treated with aqueous and ethanolic DMSO solutions or following the ethanol-wet bonding technique. Dentin bonding was performed with a three-step etch-and-rinse adhesive. Resin-dentin beams (0.8 mm2) were stored in artificial saliva at 37 °C for 24 h and 2.5 years, submitted to microtensile bond strength testing at 0.5 mm/min and semi-quantitative SEM nanoleakage analysis (n = 8). Micro-Raman spectroscopy was used to determine the degree of conversion at different depths in the hybrid layer (n = 6). Changes in the apparent modulus of elasticity of demineralized collagen beams measuring 0.5 × 1.7 × 7 mm (n = 10) and loss of dry mass (n = 10) after 30 days were calculated via three-point bending and precision weighing, respectively. ResultsDMSO-containing pretreatments produced higher bond strengths, which did not change significantly over time presenting lower incidence of water-filled zones. Higher uniformity in monomer conversion across the hybrid layer occurred for all pretreatments. DMSO-induced collagen stiffening was reversible in water, but with lower peptide solubilization. SignificanceImproved polymer formation and higher stability of the collagen-structure can be attributed to DMSO’s unique ability to simultaneously modify both biological and resin components within the hybrid layer. Pretreatments composed of DMSO/ethanol may be a viable-effective alternative to extend the longevity of resin-dentin bonds.

Benthic invertebrate assemblages and leaf‐litter breakdown along the eucrenal–hypocrenal ecotone of a rheocrene spring in Central Italy: Are there spatial and seasonal differences?

AbstractTo better understand the pattern of variation in biocomplexity of springs and first‐order streams, it is essential to explore how the characteristics of spring communities may vary from the spring source (eucrenal) to the first reach of the originating springbrook (hypocrenal). For these reasons, we assessed spatial and temporal variation of crenic assemblages and leaf‐litter breakdown along a 45‐m reach of a spring–springbrook system in Central Italy. We found that physicochemical and hydrological parameters of Vera Spring did not vary significantly along the 45‐m reach investigated. In contrast, total richness of assemblages was significantly higher at 20 and 45 m from the spring source, while abundances were more variable and did not show significant differences between seasons and among sites. The composition of assemblages did not show significant temporal trends in all sites investigated, while spatial differences along the eucrenal–hypocrenal ecotone were more prominent. The functional organization of assemblages was relatively stable in both space and time, and no spatial differences were observed in the rate of leaf‐litter breakdown, though the dry mass loss of poplar leaves was slightly higher at the most downstream site. We conclude that immediately after groundwater emergence, spring communities are less stable and more variable while they tend to be better organized at short distance downstream. Small and gradual spatial changes in the strength of competitive interactions and predation pressures may have a fundamental role in structuring spring communities more than variation in abiotic parameters and/or differences in quantity and quality of food resources.

Heat Waves Alter Macrophyte-Derived Detrital Nutrients Release under Future Climate Warming Scenarios.

In addition to a rise in global air and water mean temperatures, extreme climate events such as heat waves are increasing in frequency, intensity, and duration in many regions of the globe. Developing a mechanistic understanding of the impacts of heat waves on key ecosystem processes and how they differ from just an increase in mean temperatures is therefore of utmost importance for adaptive management against effects of global change. However, little is known about the impact of extreme events on freshwater ecosystem processes, particularly the decomposition of macrophyte detritus. We performed a mesocosm experiment to evaluate the impact of warming and heat waves on macrophyte detrital decomposition, applied as a fixed increment (+4 °C) above ambient and a fluctuating treatment with similar energy input, ranging from 0 to 6 °C above ambient (i.e., simulating heat waves). We showed that both warming and heat waves significantly accelerate dry mass loss of the detritus and carbon (C) release but found no significant differences between the two heated treatments on the effects on detritus dry mass loss and C release amount. This suggests that moderate warming indirectly enhanced macrophyte detritus dry mass loss and C release mainly by the amount of energy input rather than by the way in which warming was provided (i.e., by a fixed increment or in heat waves). However, we found significantly different amounts of nitrogen (N) and phosphorus (P) released between the two warming treatments, and there was an asymmetric response of N and P release patterns to the two warming treatments, possibly due to species-specific responses of decomposers to short-term temperature fluctuations and litter quality. Our results conclude that future climate scenarios can significantly accelerate organic matter decomposition and C, N, and P release from decaying macrophytes, and more importantly, there are asymmetric alterations in macrophyte-derived detrital N and P release dynamic. Therefore, future climate change scenarios could lead to alterations in N/P ratios in the water column via macrophyte decomposition processes and ultimately affect the structure and function of aquatic ecosystems, especially in the plankton community.

The effect of phytic acid on enzymatic degradation of dentin.

We evaluated the effect of phytic acid on matrix metalloproteinase (MMP)- or cysteine cathepsin (CC)-mediated dentin degradation. Demineralized dentin beams were divided into five groups (n=12) and treated with 1%, 2%, or 3% phytic acid or with 37% phosphoric acid. Untreated demineralized beams served as controls. After incubation for 1 or 3wk, dry mass loss was determined and aliquots of incubation media were analysed for cross-linked telopeptide of type I collagen (ICTP) fragments for MMP-mediated and c-terminal telopeptide of type I collagen (CTX) for cathepsin-k-mediated degradation. The direct effect of phytic acid was evaluated using MMP activity assay. Data were analysed using repeated-measures anova. ICTP releases with 1% and 2% phytic acid treatment were statistically significantly lower than those following phosphoric acid treatment at 3wk. The CTX release for phytic acid-treated beams at 3wk was not significantly different from that of untreated control beams, but it was significantly lower than that of phosphoric acid-treated beams. Their MMP activities at 3wk were not significantly different from those of the controls but they were significantly lower than those seen for phosphoric acid-treated beams. Compared to phosphoric acid, phytic acid treatment resulted in a reduced dentinal host-derived endogenous enzymatic activity and collagen degradation.

Differential responses of litter decomposition in the air and on the soil surface to shrub encroachment in a graminoid-dominated temperate wetland

Graminoid-dominated wetlands have been subjected to widespread shrub encroachment, yet the effect of this shift in species composition on litter decomposition remains unclear, especially in the standing-dead stage. We collected labile (Deyeuxia angustifolia) and recalcitrant (Carex schmidtii) graminoid leaf litter from a freshwater wetland in northeast China, and used the litterbag method to characterize litter ash-free dry mass (AFDM) loss and nitrogen (N) release in the air and on the soil surface in open wetlands and two shrub islands (Salix floderusii producing phenol-poor litter and Betula fruticosa producing phenol-rich litter) over 360 days of decomposition. Litter decomposition in the air and on the soil surface responded differentially to shrub expansion. In the air, AFDM loss and N release for both labile and recalcitrant litter were often lower in shrub islands than in open wetlands. On the soil surface, labile litter decomposition was decelerated in the presence of shrubs with phenol-rich litter, but accelerated in the presence of shrubs with phenol-poor litter. Despite the absence of significant differences in N release, recalcitrant litter AFDM loss was lower in shrub islands than in open wetlands after 360 days of decomposition on the soil surface. Shrub encroachment retards litter decomposition in the air, but the effects on litter decomposition on the soil surface vary with shrub type and litter degradability in graminoid-dominated wetlands. Moreover, these findings emphasize that standing litter decomposition should be considered to enhance our understanding of shrub encroachment effects on litter decomposition in these wetlands.

Three new methods indicate that CO2 concentration affects plant respiration in the range relevant to global change.

Short-term responses of plant dark respiration to carbon dioxide concentration ([CO2]) in the range anticipated in the atmosphere with global change remain controversial, primarily because it is difficult to convincingly eliminate the many possible sources of experimental error in measurements of carbon dioxide or oxygen exchange rates. Plant dark respiration is a major component of the carbon balance of many ecosystems. In seedlings without senescent tissue, the rate of loss of dry mass during darkness indicates the rate of respiration. This method of measuring respiration was used to test for [CO2] effects on respiration in seedlings of three species with relatively large seeds. The time it took respiration to exhaust substrates and cause seedling death in darkness was used as an indicator of respiration rate in four other species with smaller seeds. The third method was measuring rates of CO2 exchange in excised petioles sealed in a cuvette submerged in water to prevent leaks. Petioles were utilized as the plant tissue type with the most reliable rates of respiration, for excised tissue. The rate of loss of dry mass in the dark decreased with increasing [CO2] in the range of 200-800 μmol mol-1 in all three large-seeded species. The seedling survival time in the dark increased with [CO2] in the same concentration range in all four of the smaller-seeded species. Respiration rates of excised petioles of several species also decreased over this [CO2] range. The data provide new evidence that the rate of dark respiration in plant tissue often decreases with increasing [CO2] in the 200-800 μmol mol-1 range.

Effect of Broken Coffee Beans Particle Size, Roasting Temperature, and Roasting Time on Quality of Coffee Beverage

Optimum flavor and aroma of the coffee are developed during the roasting process. However, certain problems exist in the coffee roasting process such as partial charring, over roasting, and poor temperature distribution across the coffee bean (due to the low thermal conductivity of bean), if conditions are not optimized. Hence, uniform temperature distribution across the coffee bean in the roasting process is highly desirable. To achieve these requirements, the broken coffee beans were positioned in a single layer packed bed arrangement using the closed system by circulating hot air. In this experiment, three factors were arranged in a completely randomized design with three levels and three replications. The first factor considered was roasting temperature (200°C, 230°C, and 260°C), second factor was roasting time (5 min, 10 min, and 15 min), and third was particle size (4–6 mm, 2.36–3.35 mm, and 1.7–2.36 mm). The initial moisture content of raw beans (cv. Limu) was determined. The data were collected on selective physical properties of roasted coffee beans and sensory acceptability of prepared beverage. The results showed that the physical properties and sensory acceptability are significantly high ( P &lt; 0.001 ). It depends on the interaction effect of all the studied factors. Among the studies parameters, roasting temperature of 230°C with a particle size range of 4–6 mm showed the steady transition in dry mass loss and change in bulk density with increase in roasting duration. Coffee roasted at 230°C for 10 min with a particle size of 4–6 mm showed the highest sensory acceptability score (89.21). In conclusion, it can be said that a temperature of 230°C, a time of 10 min, and a particle size between 2.36–3.35 mm and 4–6 mm are recommended conditions for the roasting process of coffee beans.

Novel Orthodontic Cement Comprising Unique Imidazolium-Based Polymerizable Antibacterial Monomers.

White spot lesions (WSLs) can develop quickly and compromise the successful outcome of the orthodontic treatment. Orthodontic bonding cement with the capability to prevent or mitigate WSLs could be beneficial, especially for patients with high risk of caries. This study explored novel mono- and di-imidazolium-based polymerizable antibacterial monomers and evaluated orthodontic cement compositions comprising such novel monomers. Their antibacterial potentials, mechanical properties, and shear bond strength (SBS) to bovine enamel were investigated. Statistical tests were applied to SBS and mechanical tests (one-way ANOVA and Tukey’s test). For antibacterial resins C (ABR-C) and E (ABR-E), their minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against cariogenic Streptococcus mutans bacterial strain UA159 were found to be 4 μg/mL and 8 μg /mL, respectively. The loss of dry mass from completely demineralized dentin beams in buffer solutions pre-dipped into ABR-C and ABR-E resins is much less than that in control buffer (artificial saliva) only. For unfilled resins comprising up to 12 wt % ABR-C, no significant decreases in flexural strength or modulus were observed. For experimental cements incorporating 1–4 wt % ABR-C, there was no drastic compromise to the SBS to enamel except for 3 wt % ABR-C. Furthermore, their SBS was all comparable to the commercially available orthodontic cements. The ISO-22196 antimicrobial test against S. aureus showed significant levels of antibacterial effects—up to over 5 logs of microorganism reduction exhibited by ABR-C-containing experimental cements. The imidazolium-based polymerizable monomers could be utilized to functionalize orthodontic bonding cement with steady antibacterial activity and develop a potential strategy to counteract WSLs.

Physical and chemical indicators of transformations of poultry carcass parts and broiler litter during short term thermophilic composting

Short-term on-site composting of poultry carcasses and broiler litter (BL) is considered as a feasible technology for pathogen elimination during events of mass mortality in poultry houses. However, factors related to mass losses and physical transformation of the poultry carcass, and associated emissions of volatile organic compounds (VOCs) and odors, have not been thoroughly evaluated. This study aims to characterize the degradation of separated carcass parts co-composted with BL and the associated air emissions during 30 days of enclosed composting at 50 °C with constant aeration. The study was carried out in lab-scale simulators using five mixtures containing feathers, rib bones, skins, breast muscles, and hearts and livers, prepared at a 1:2 volumetric ratio (carcass:BL). Dry mass losses reached 59.5, 41.1, 60.8 and 103.5% (based on weight) or 48.4, 29.6, 49.7, and 94.8% (based on CO2-C and NH3-N emissions), for rib bones, skins, breast muscles, and hearts and livers, respectively. Visually, most of the carcass parts were degraded, and the typical carcass odor had disappeared by the end of the 30 days. Out of 24 VOCs, dimethyl disulfide (DMDS) and dimethyl trisulfide (DMTS) contributed 80.7–88.3% of the total VOC flux, considering the partial contribution of each part to the emissions involved with the whole carcass. DMDS, DMTS, benzaldehyde, methanethiol, pentanoic acid, and NH3, contributed 90.5–97.9% of the odor activity values during composting. DMDS/DMTS ratio is suggested as a potential biomarker of stabilization and readiness of the compost for transportation toward further treatment or safe burial.

Effect of drought stress on indigo and seed yield of Indigofera tinctoria ecotypes

The objective of the the current study was to elucidate the effect of drought stress on indigo yield and to derive certain morphological traits of indigo ecotypes. This experiment was laid out in a split-plot arranged at a randomized complete block design, with three replications in the Jiroft Agricultural and Natural Resources Research and Education Center, Kerman, Iran, during 2013-14 growing seasons. The main plot and the subplot included drought stress (100, 75, and 50% of crop water requirement) and indigo ecotypes (Jiroft, Roudbar, Rigan, and Ghale Ganj), respectively. The obtained results showed that morphological and indigo content attributes revealed significant differences between the control and the drought-stress plants. Increasing water stress (up to 50% of crop water requirement) resulted in a severe loss of leaf dry mass, plant height, and seed yield of 25, 25 and 58%, respectively, in comparison to the control condition; the highest indigo yield and content obtained from the mid-stress level. Moreover, interaction effects of drought and ecotypes on leaf dry mass, seed, and indigo yield were significant; thus, the LDM and seed yield was the greatest in the Jiroft ecotype in the control, the indigo yield was the greatest under mid-level stress, and it was the lowest in the Ghale Ganj ecotype under severe water-stress level. Therefore, the results of this research suggest that the Jiroft ecotype will perform well with respect to drought tolerance and will be useful for cultivation in the semi-arid regions of Jiroft.

Water sorption hysteresis in wood near 100 °C

Abstract Whether water sorption hysteresis exists above 75 °C and the representation of its relationship with wood softening remains unclear. In this study, sorption hysteresis at three temperature levels, namely, 75, 90 and 99.5 °C, was investigated using accurately controlled conditioning chambers using powder samples from seven wood species. The dry mass loss percentage of the samples and proper equilibrium time was evaluated by pretests to ensure reliable sorption isotherms afterwards. The dry mass loss percentage after the entire sorption isotherm running needs to be kept within 0.5% to avoid complications in determining the equilibrium time. The abrupt increase of equilibrium moisture content at high relative humidity regions and the crossover of adsorption isotherms were not observed. Hysteresis was conspicuous at 75 and 90 °C and was statistically confirmed at 99.5 °C. High sample extractives content or unnecessarily long equilibrium time would cause significant sample dry mass loss, which may suppress the desorption isotherm to an extent that leads to unjustified hysteresis disappearance. The hysteresis behavior observed in this study suggests that wood softening does not necessarily result in hysteresis disappearance, and the explanation of hysteresis progression as a function of wood softening temperature must be evaluated with care in the future.