Acetic Treatment Research Articles

Copper–Chitosan-Modified Magnetic Textile as a Peroxidase-Mimetic Catalyst for Dye Removal

Copper chitosan attached to a magnetic synthetic nonwoven textile was manufactured using a simple, rapid, and green procedure employing chitosan dissolved in diluted acetic acid and treatment with copper sulfate solution. The prepared copper–chitosan-modified textile exhibited peroxidase-mimetic activity which was subsequently used for the degradation (decolorization) of important organic dyes, namely methylene blue, Congo red, and Bismarck brown Y, in the presence of hydrogen peroxide. After 5 h of treatment at 22 °C, 87.5%, 79.5%, and 87.7% dye removal were observed for methylene blue, Congo red, and Bismarck brown Y, respectively. The textile bound catalyst can be easily recovered from the reaction mixture after the process is completed.

Reduction and structural modification of MoOx/γ-Al2O3 catalysts through acetic acid treatment for green diesel production from corn distiller’s oil

Enabling new environmentally-friendly resources for fuels and platform chemicals is crucial to fulfill our future energy demands while enhancing circularity. Corn distiller’s Oil (CDO) − as a coproduct of the ethanol industry, serves as a sustainable supply of carbon that may be converted into energy, fuels and specialty chemicals. A current challenge in using renewable oxygenated feedstocks is the high amount of coking and catalyst fouling that occurs. This study examined the hydrothermal deoxygenation of CDO into green diesel using molybdenum oxide (MoOx) catalysts in a continuous process without using any external hydrogen. The possibility of reduction and developing oxygen-deficient surfaces on molybdenum oxide (MoOx) catalysts through acetic acid treatment or adding ceria (CeO2) was investigated in order to enhance the acidity of catalysts as well as catalytic activity and stability required for the production of green diesel from CDO. Results showed that the acidity of these catalysts as measured by NH3 temperature programmed desorption (NH3-TPD) had a strong correlation between the degree of deoxygenation and catalyst stability. Acetic acid treatment of the 7.5 wt% MoO3/γ-Al2O3 catalyst reduced MoO3 to MoO3-x, increased the Mo5+ species from 8.7 % to 22 %, created Mo4+ species and increased the catalyst surface acidity in the range of low to moderate strength by approximately 17 %. The use of acetic acid-treated molybdenum oxide (Hac-7.5 wt% MoO3/γ-Al2O3) catalyst enabled nearly complete (99.9 %) deoxygenation of CDO and heavy hydrocarbons cracking to produce diesel-like fuels. A moderate increase in catalyst surface acidity by acetic acid treatment also increased the selectivity of diesel-like fuel through hydrocracking of long-chain hydrocarbons. This low-cost modification step of catalyst improvement is promising for industrial application. However, cracking of hydrocarbons generated amorphous coke (no graphitic coke was observed) on the catalyst surface, which required periodic removal by controlled calcination of the catalyst in presence of air for further use.

Effects of volatile fatty acids on soil properties, microbial communities, and volatile metabolites in wheat rhizosphere of loess

The Loess Plateau faces critical challenges due to soil degradation. In this context, using volatile fatty acids (VFAs) from biowaste as readily available soil conditioners offer promising sustainable solutions to restore soil quality and enhance agricultural productivity. The study examined how applying different VFAs as soil amendments in arid and high-salt loess soil affected wheat plant growth, soil properties, soil microbial community diversity, volatile metabolites in soil and root exudate. The non-targeted analysis was used to identify and classify 49 soil volatile organic compounds (VOCs) and 63 root exudate VOCs to seek further specific functional volatile metabolites and explore the interaction mechanisms among plants, microorganisms, and soil. The results showed that acetic acid increased soil EC by 21.0% and decreased soil organic matter by 14.4%. Propionic acid reduced soil organic matter by 14.7%. Valeric acid increased the average root diameter by 15.1%. Further analysis revealed that rhizosphere bacterial communities, but not fungal communities, showed greater sensitivity to VFAs application. Bacterial α diversity was significantly reduced in the acetic acid treatment. The main contribution of VOCs in soil with acetic acid and propionic acid applications was alcohol, and its relative percentage was 50.06% and 43.54%, respectively, which has a significantly negative correlation with the α diversity of soil bacteria. On the contrary, the content of acylamides in soil with butyric acid and valeric acid applications was higher and significantly positively correlated with the average root diameter. It was concluded that soil microbial communities respond rapidly to acetic acid, propionic acid, butyric, and valeric acid applications by adjusting the concentration of alcohols and acylamides as secondary metabolites, respectively. This study revealed the close relationship between VFAs application type and soil properties, soil microbial community diversity, soil VOCs, and root exudates VOCs. VFAs derived from biowaste will contribute to restoring loess soil quality and achieving sustainable agriculture.

Behind the scenes: metagenomic analysis of bacterial communities in sustainable depilation of sheepskin.

The leather industry is embracing eco-friendly technologies for both regulatory compliance and sustainable growth. While enzymatic depilation provides a greener alternative to traditional beamhouse methods, its complexity often leads to higher costs. To address this, we examined the performance of sheepskins' native bacterial flora in acetic acid conditions with low-environmental impact. Utilizing metagenomic techniques, we analyzed the bacterial community dynamics during the depilation process. This investigation revealed a notable increase in microbial diversity and richness in acetic acid treatments compared to water treatments. At the class level, a post-processing decrease in Gammaproteobacteria dominance was observed, while Actinomycetia numbers surged in the acetic acid group. In contrast, the water group showed an increase in Bacteroidia. Order-level analysis indicated reductions in Pseudomonadales and increases in Actinomycetales with acetic acid treatment, whereas Flavobacteriales was more prevalent in water-treated liquors. At the family level, Moraxellaceae decreased and Micrococcaceae increased in the acetic acid group, in contrast to the marked rise of Weeksellaceae in the water group. Temporal analyses further highlighted the evolving bacterial landscapes under different treatments. Moreover, acetic acid treatment fostered a stable microbial community, beneficial for sustainable leather processing. Functional pathways were predicted using PICRUSt2. It showed that significantly enriched degradation pathways in the water group were less abundant in the acetic acid group, potentially preventing substrate matrix damage during depilation. The study underscores the transformative potential of acetic acid for the leather industry, offering a pathway to reduce pollution while maintaining economic viability. By enhancing our understanding of microbial interactions during depilation, this study opens avenues for refining these eco-friendly techniques. Our findings advocate for a shift towards greener depilation methods and contribute to the broader dialogue on sustainable manufacturing practices, emphasizing the importance of leveraging indigenous microbial communities for environmental and economic gains.

A novel macroporous carboxymethyl chitosan/sodium alginate sponge dressing capable of rapid hemostasis and drug delivery

Carboxymethyl chitosan (CMCS) and sodium alginate (SA), which are excellent polysaccharide-based hemostatic agents, are capable of forming polyelectrolyte complexes (PEC) through electrostatic interactions. However, CMCS/SA PEC sponges prepared by the conventional sol-gel process exhibited slow liquid absorption rate and poor mechanical properties post-swelling. In this work, a novel strategy involving freeze casting followed by acetic acid vapor treatment to induce electrostatic interactions was developed to fabricate novel PEC sponges with varying CMCS/SA mass ratios. Compared to sol-gel process sponge, the novel sponge exhibited a higher density of electrostatic interactions, resulting in denser pore walls that resist re-gelation and swelling according to FTIR, XRD, and SEM analyses. Additionally, the liquid absorption kinetics, as well as compression and tension tests, demonstrated that the novel sponge had significantly improved rapid blood absorption capacity and mechanical properties. Furthermore, in vitro coagulation and drug release studies showed that the novel sponge had a lower blood clotting index and clotting time, along with a slower drug release rate after loading with berberine hydrochloride, showcasing its potential as a rapid hemostatic dressing with controlled drug release capabilities.

SENSITIVE TO FREEZING2 is crucial for growth of Marchantia polymorpha under acidic conditions.

Land plants have evolved many systems to adapt to a wide range of environmental stresses. In seed plants, oligogalactolipid synthesis is involved in tolerance to freezing and dehydration, but it has not been analyzed in non-vascular plants. Here we analyzed trigalactosyldiacylglycerol (TGDG) synthesis in Marchantia polymorpha. TGDG is synthesized by galactolipid: galactolipid galactosyltransferase [GGGT; SENSITIVE TO FREEZING2 (SFR2) in Arabidopsis]. We analyzed the subcellular localization and GGGT activity of two M. polymorpha SFR2 homologs (MpGGGT1 and MpGGGT2, each as a GFP-fusion protein) using a transient expression system in Nicotiana benthamiana leaves and found that MpGGGT1-GFP localized in the chloroplast envelope membrane. We produced mutants Mpgggt1 and Mpgggt2 and found that TGDG did not accumulate in Mpgggt1 upon treatment of the thallus with acetic acid. Moreover, growth of Mpgggt1 mutants was impaired by acetic acid treatment. Microscopy revealed that the acetic acid treatment of M. polymorpha plants damaged intracellular membranes. The fact that the effect was similar for wild-type and Mpgggt1 plants suggested that MpGGGT has a role in recovery from damage. These results indicate that MpGGGT plays a crucial role in M. polymorpha growth under conditions of acid stress, which may have been encountered during the ancient terrestrial colonization of plants.

Preparation of MAZ-Type Zeolite with High Silica.

The Si/Al molar ratio of MAZ aluminosilicate zeolite prepared by the direct hydrothermal method is generally less than five, thus giving rise to poor thermal and hydrothermal stability for this low-silica zeolite. With the purpose of enhancing the Si/Al molar ratio of MAZ zeolite, post-synthesized methods including acetic acid treatment and steaming treatment, as well as interzeolite transformation from FAU zeolite, were employed to prepare MAZ zeolite with high silica. It was found that steaming treatment was more effective in increasing the Si/Al molar ratio in comparison with acetic acid treatment, affording a maximum Si/Al molar ratio of 16.9 along with a preserved crystallinity of approximately 75%. Additionally, high-silica MAZ zeolite with a Si/Al molar ratio of up to 7.3 was also capable of being directly hydrothermally synthesized using interzeolite transformation from FAU zeolite.

Light-driven acetic acid coupling for the production of succinic acid

Treating and recycling high concentration acetic acid in the exhaust water has long posed a challenge in industry. These wastes containing acetic acid are typically processed via basic neutralization, characterized by high acidity and resistance to degradation, which can bring potential economic burden and environmental hazards. Here we report a new photocatalytic conversion route for addressing high concentrations of acetic acid. This process transforms acetic acid into valuable succinic acid through dehydrogenative coupling. Additionally, the photocatalytic conversion of acetic acid exhibits structure sensitivity when employing Pt cocatalysts of varying sizes. Through inhibiting the undesirable H termination of active free radicals over small Pt atoms and clusters, the rate of undesired decarboxylation reactions can be decreased by 75 %. This effectively enhances the selectivity of the coupling product succinic acid by 2.1 times, achieving a succinic acid formation rate of 7.28 mmol/(gcat•h). This work offers a theoretical guidance for searching value-added reaction pathways of acetic acid, thereby establishing an innovative approach for high concentration exhaust acetic acid treatment and converting low value monocarboxylic molecules into valuable diacid polymerization monomers under a mild and green condition.

The Impact of Tadbir as a Pre-Application Treatment of Medicinal Plants on Their Chemical Profiles and Biological Activities in Traditional Persian Pharmacy

Based on basic traditional medicine practice, many plants undergo primary treatments to improve their pharmacological characteristics or to attenuate unwanted or unfavorable features of drugs before incorporating them into drug formulations. These treatments are called “Tadbir” in Traditional Persian Medicine (TPM). The purpose of these processes includes but is not limited to eliminating unnecessary compounds, excluding harmful properties such as toxicity and poignancy, and improving their overall natural properties and effectiveness. Here, the effect of vinegar and acetic acid treatment on three herbal specimens, including Carum carvi L. fruits (CC), Trachyspermum ammi (L.) Sprague fruits (TA), and Nigella sativa L. seeds (NS) were investigated. The treated and non-treated samples were subjected to essential oil and methanol extraction. Further, to assess the alterations in the essential oil constituents caused by Tadbir, samples were analyzed by Gas Chromatography/Mass Spectrometry (GC/MS) and HPTLC fingerprinting techniques. Total phenol and flavonoid content and DPPH free radical scavenging activity of methanol extracts were evaluated. As a result of the treatments, TA extracts showed significant rise in phenol and flavonoid contents. Total phenol content increased from 98.50±1.01 in non-treated increased to 181.20±0.27 mg GAE/g Ext. in the vinegar-treated TA fruit extract and total flavonoid showed a rise from 8.97±1.12 to 12.89±0.41 mg QE/g Ext. This may be the reason behind its lower IC50 values in DPPH free radical scavenging assay. Interestingly, Tadbir treatment of TA fruits with 4% acetic acid, lowered the IC50 value from 1019.42±75.65µg/mL in non-treated control to 274.2±17.22 µg/mL; while vinegar caused a lower degree of reduction in IC50 value (369.4±5.54 µg/mL) in DPPH free radical scavenging assay. However, CC fruit extracts, showed a decrease in phenolic content; while demonstrating an increase in flavonoids. Interestingly, phenol and flavonoid contents were significantly enhanced in treated NS seed extracts. The results of all extracts were found significantly different (p<0,05) from each other and the non-treated control. The conclusive results of the present study may partly justify the pre-application of Tadbir treatments of medicinal plants in traditional pharmacy.

Oral Administration Properties Evaluation of Three Milk-Derived Extracellular Vesicles Based on Ultracentrifugation Extraction Methods.

Milk-derived extracellular vesicles (M-EVs) are low-cost, can be prepared in large quantities, and can cross the gastrointestinal barrier for oral administration. However, the composition of milk is complex, and M-EVs obtained by different extraction methods may affect their oral delivery. Based on this, a new method for extracting M-EVs based on cryogenic freezing treatment (Cryo-M-EVs) is proposed and compared with the previously reported acetic acid treatment (Acid-M-EVs) method and the conventional ultracentrifugation method (Ulltr-M-EVs). The new method simplifies the pretreatment step and achieves 25-fold and twofold higher yields than Acid-M-EVs and Ulltr-M-EVs. And it is interesting to note that Cryo-M-EVs and Acid-M-EVs have higher cellular uptake efficiency, and Cryo-M-EVs present the best transepithelial transport effect. After oral administration of the three M-EVs extracted by three methods in mice, Cryo-M-EVs effectively successfully cross the gastrointestinal barrier and achieve hepatic accumulation, whereas Acid-M-EVs and Ultr-M-EVs mostly reside in the intestine. The M-EVs obtained by the three extraction methods show a favorable safety profile at the cellular as well as animal level. Therefore, when M-EVs obtained by different extraction methods are used for oral drug delivery, their accumulation properties at different sites can be utilized to better deal with different diseases.

One story as part of the Global Conversation on Sustainability: dye adsorption studies using a novel bio-derived calcite material.

Many of the United Nations' Sustainable Development Goals (SDGs) can be addressed through chemistry. Researchers at Memorial University of Newfoundland, Canada, have been sharing their stories on September 25 for the past two years through the Global Conversation on Sustainability. This article describes the details of one of these stories. As the global population increases, food production including aquaculture is increasing to provide for this. At the same time, this means more waste is produced. Waste from aquaculture isoften overlooked as a source of valuable chemicals. By-products from farming blue mussels (Mytilus edulis) is dominated by shells rich in calcite. A 'soft' calcite material prepared from waste mussels, via a combination of heat and acetic acid treatment, was investigated for its adsorptive properties and its possible use in wastewater remediation. The adsorption of two cationic dyes, methylene blue and safranin-O, on this material were evaluated through isothermal and kinetic modelling. The adsorption systems for both methylene blue and safranin-O can best be described using Langmuir isotherms and the respective adsorption capacities were 1.81 and 1.51 mg/g. The adsorption process was dominated by pseudo-second order rate kinetics. Comparisons are made with other mollusc-derived materials reported to date.

Optimizing Fixation Duration for Enhanced Clarity in Pediculus humanus capitis Whole Mount Preparations Using 10% KOH at 70°C

This study evaluates the optimal fixation duration using 10% potassium hydroxide (KOH) at 70°C for whole mount preparations of Pediculus humanus capitis (head lice). Accurate head lice identification is crucial for effective public health management. Specimens were fixed for 20, 25, 30, 35, and 40 minutes at 70°C, then processed through rinsing, acetic acid treatment, dehydration, and clearing before mounting for microscopic examination. Results showed that 25 minutes of fixation provided the clearest and most detailed preparations. This duration effectively achieved tissue dehydration and clarification without significant damage. Fixation for 20 minutes was insufficient, resulting in opaque specimens due to incomplete KOH diffusion. Conversely, 40 minutes of fixation caused over-fixation, leading to tissue damage and poorer color quality. The study underscores the importance of finding the right fixation duration. While shorter times are inadequate, longer durations can degrade specimen quality. A 25-minute fixation at 70°C is optimal for balancing clarity and structural preservation, improving head lice identification. This method enhances the quality of whole mount preparations and provides practical guidance for accurate and reliable ectoparasite examination in clinical and research settings.

Growth of tungsten disulfide bilayers featuring Moiré superlattices: A surface energy perspective

The bilayer (BL) transition metal dichalcogenides (TMDs), with their elevated carrier mobility and narrowed bandgap, are advantageous for future electronic applications in comparison with their monolayer (ML) counterparts. Here, we introduce a facile and efficient approach for the chemical vapor deposition synthesis of BL WS2. The method involves an acetic acid sonication treatment to modify the substrate surface morphology and the surface energy, which regulates the nucleation processes and shapes the growth mode of WS2 crystals. Further modifications to the growth conditions yield high-quality ML and BL WS2 films. A comparative study confirms the superior valley polarization and higher carrier mobility of BL WS2 compared with its ML counterpart. Additionally, a minor twist angle existed between the upper and lower layers, featuring a Moiré superlattice. This work reveals the role of surface morphology and surface energy in the growth of TMDs. Simultaneously, it offers insights into the controlled preparation of vertically stacked homo- and heterojunctions.

Preparation and mechanical properties of Portland cement composites filled with bamboo fibres modified by acetic acid and fermentation treatment

To improve the compatibility between Portland cement and bamboo fibre, bamboo fibres were modified by acetic acid and fermentation treatment and the modified bamboo fibres/Porland cement composites were prepared. The hydration curves of the bamboo fibres/Porland cement composites were measured and the area ratio under the cement hydration heat curve was used as the compatibility coefficient to evaluate the compatibility of bamboo fiber and cement. The hydration products at different hydration times were characterized by XRD, FTIR, and SEM. Moreover, the mechanical strengths of standard test blocks of Portland cement/bamboo fibre composites were tested to further verify the improved compatibility of bamboo fiber and Portland cement. The study shows that the compatibility between bamboo fibre and Portland cement was improved from 9% to 87%, the bending strength of Portland cement/bamboo fibre composite was increased from 638 N to 3678 N, and the compressive strength was increased from 1.5 MPa to 34.35 MPa.

Facile fabrication of high-strength biocomposite through Mg2+-enhanced bonding in bamboo fiber

The emerging interests in high-performance biocomposites grows significantly driven by their superior environmental sustainability. This study proposes a unique biocomposite strategy by implementing an acetic and ball-milled treatment to disrupt the bamboo cell wall structure, thereby facilitating further processing by effectively increasing the active sites and specific surface area in the bamboo fiber. The fibers are subsequently carboxymethylated to introduce carboxyl groups which facilitate physical bonding between the fibers and Mg2+ ions that are added to the system. These ions form metal-coordination bonds with the carboxyl groups, acting as ion bridges that significantly strengthen the inter-fiber bonding. The resulted biocomposite exhibits impressive mechanical properties, including a high tensile strength (94.24 MPa) and flexural strength (104.14 MPa), not only that, changes in elastic modulus also highlight changes in fiber bonding, the flexural modulus is 21.29 GPa and the tensile modulus is 7.01 GPa. Moreover, it maintains a low water uptake capacity of only 6.8 % despite being submerged for 12 h. The thermal conductivity and fire retardancy have also been improved. The synergic bonding ability between the cellulose and lignin in the fibers, coupled with the glue-free thermoforming process, enhances the material performance and renders it fully recyclable, thus reducing environmental pollution and providing cost-effective engineering materials to society.

Utility of anticoagulation, pre-smearing and post-smearing hemolytic techniques on morphological assessment and reproducibility in fluid cytology.

Knowledge of proper collection, storage, preservation, and processing techniques is critical to ensuring proper handling and analysis of fluid cytology specimens. This study was conducted to determine the effect of anticoagulation, pre-smearing acetic acid treatment technique, and saline rehydration technique on morphological assessment, reproducibility, and reporting in fluid cytology. The study was carried out in the cytopathology laboratory over 2 months (April-May 2022), where 100 effusion samples were analyzed. At least 20-40 mL of fluid was collected in heparinized and non-heparinized containers for each patient. Samples were processed in cytospin and stained with Giemsa and Papanicolaou stains. For 70 hemorrhagic specimens, an extra smear was prepared from the sediment and subjected to the saline rehydration technique as per the Indian Academy of Cytologists (IAC) guidelines. Seventy-three hemorrhagic specimens whose quantity received was more than 35 mL were subjected to the pre-smearing technique. These smears were evaluated for (a) the presence or absence of blue background/any other background staining, (b) cellularity, (c) cell morphology and (d) the presence/absence of microclots. Heparinized samples showed no compromise in cellular morphology or cellularity although a blue background was observed in an occasional case. The pre-smearing technique had less background hemorrhage and preserved cell characteristics. The post-smearing saline rehydration technique did not compromise the cellularity but distorted morphology and showed background staining. The pre-smearing acetic acid treatment showed better-preserved cellularity and cytomorphology with the absence of background staining when compared to the post-smearing saline rehydration technique.

Evaluation of organic options for Johnsongrass (Sorghum halepense) control during winter fallow

AbstractJohnsongrass [Sorghum halepense (L.) Pers.] is one of the most problematic perennial grass weed species in row-crop production across the southern United States. Control of this species is especially challenging in organic systems due to a lack of effective options. A field experiment was conducted at the Texas A&M research farm near College Station, TX, from fall 2019 to spring 2021 to evaluate various nonchemical options for managing S. halepense in the fallow season, implemented over 2 yr in the same locations. The treatments included disking once, disking twice, disking + immediate flooding, disking + flush irrigation + flooding, disking twice + flooding after the first frost, periodic mowing, acetic acid treatment, and disking + tarping. Disking + immediate flooding, disking + flush irrigation + flooding, and disking + tarping were the most effective treatments. Compared with the nontreated control plots, these treatments reduced S. halepense aboveground density (<9 plants m−2 vs. 64 plants m−2), aboveground biomass (<80 g m−2 vs. 935 g m−2), rhizome biomass (<4 g m−2 vs. 55 g m−2), rhizome node number (<25 nodes m−2 vs. 316 nodes m−2), and rhizome length (<42 cm m−2 vs. 660 cm m−2). Disking twice + flooding after the first frost did not show a consistent impact. Periodic mowing also reduced S. halepense density (12 plants m−2 vs. 64 plants m−2) and other variables compared with the control plots at the end of the study in spring 2021. Disking alone once or twice each growing season or repeated application of acetic acid failed to control S. halepense. These results indicate that well-timed nonchemical management practices such as tarping and flooding implemented during the winter fallow can be very effective in reducing S. halepense densities.

Effects of acetic acid treatment on growth and pigment contents in barley

Acetic acid (AA) is an organic acid and has been widely used as food preservative and a dietary spice in vinegar form. In addition to its therapeutic uses in its vinegar form, AA attenuates inhibitory effects of stress in plants. However, in some plant species toxic effects of AA have been found. Therefore, in this study, 0, 2.5 and 5 mM concentrations of AA were applied to 2-day-old barley (Hordeum vulgare L. cv. Bornova-92) seedlings for 2 days in order to investigate the possible toxic effects of AA. After treatments, seedlings were grown in AA-free conditions for 2 days to recover. AA inhibited root and shoot growth; decreased water content, fresh weight, chlorophyll, pheophytin, and carotenoid contents. However, anthocyanin and flavonoid contents, as well as the levels of UV-absorbing compounds and UV-B marker increased in the leaves of AA-treated plants. AA increased hydrogen peroxide (H2O2) content in shoots and induced cell death in roots. Soluble carbohydrate content decreased in roots of AA-treated plants while insoluble carbohydrate content increased. Our results demonstrate that AA in young barley seedlings can exhibit its toxic effects through oxidative stress, which induced antioxidative response in the form of molecules with antioxidative activities. These effects persisted for 2 days after the removal of AA.

Xylooligosaccharides and glucose preparation from sugarcane bagasse by a combination of acetic acid treatment and sequential xylanase and cellulase enzymatic hydrolysis

Acetic acid of 2.5–10% (m/v) can be exploited to assisted hydrolyze sugarcane bagasse for directly producing XOS, however, it simultaneously generated high amounts of byproducts, increasing the difficulty of products purification, and there are evidences that the ratio of active ingredients (xylobiose (X2) and xylotriose (X3)) was lower. In this study, a strategy of acetic acid pretreatment with post-xylanase treatment of sugarcane bagasse for preparing xylooligosaccharides (XOS) was put forward. Firstly, the acid hydrolysis with post-xylanase hydrolysis processes varied the parameters applying single-factor experiments design using the 2.5–10% (m/v) acetic acid at a temperature of 130–190 °C and a duration of 20–60 min. According to single-factor experiments, a three-level three-factor Box-Behnken Design with response surface methodology was performed to maximize the XOS yields. As a results, the maximum XOS yield was achieved at over 60.7% with a sequential operation of acid hydrolysis (3.6% acetic acid, 180 °C, 35 min) and xylanase hydrolysis (12 h), and the ratio of (X2 + X3)/XOS was over 70%. Moreover, the treatment with 3.6% acetic acid and xylonase also improved enzymatic hydrolysis yield to 82.1%. Overall, favorable outcomes suggest that the combined approach of acidic and enzymatic hydrolysis is cost-effective for XOS with desired degree of polymerization and glucose preparation.

Investigation of the crystal formation from calcium silicate in human dentinal tubules and the effect of phosphate buffer saline concentration

Background/purposeBased on hydrodynamic theory, blocking the dentinal tubules can reduce discomfort caused by dentin hypersensitivity. This study identified the crystals formed in dentinal tubules from tricalcium silicate (TCS) in phosphate-buffered saline (PBS) and evaluated the effect of PBS concentration on crystal formation. Materials and methodsSixty-nine specimens were made by isolating the cervical part of extracted premolars. TCS was applied by brushing for 10,000 strokes on dentin surface simulating sensitive dentin. Specimens were stored in PBS or solutions with concentrations 1/100, 1/10, 10, and 100 times that of PBS for 1, 30, 60, or 90 days (n = 3). Another nine specimens applied TCS, were immersed in PBS for 3 months, and divided into three subgroups: no treatment, sonication for 10 min, and 1M acetic acid treatment for 3 min. Crystal formation was examined using a scanning electron microscope, assigned five grade scores (0–4) according to maturation, and analyzed by a nonparametric two-way ANOVA (α = 0.05). Crystal components were analyzed using X-ray diffraction (XRD) and energy dispersion X-ray spectroscopy (EDS). ResultsThe maturation of intratubular crystals was dependent on time and PBS concentration (P < 0.05). In all periods, the high-concentration group showed a higher maturation grade than the low-concentration group. Intratubular crystals were similar to hydroxyapatite according to XRD and EDS, and they withstood sonication and acid application. ConclusionTCS with nanosized particles formed hydroxyapatite-like crystals in the dentinal tubules, which were dependent on time and concentration of PBS and withstood sonication and acid application.