Effect Of Dosage Research Articles

Removal of the large inverted repeat from the plastid genome reveals gene dosage effects and leads to increased genome copy number.

The chloroplast genomes of most plants and algae contain a large inverted repeat (IR) region that separates two single-copy regions and harbours the ribosomal RNA operon. We have addressed the functional importance of the IR region by removing an entire copy of the 25.3-kb IR from the tobacco plastid genome. Using plastid transformation and subsequent selectable marker gene elimination, we precisely excised the IR, thus generating plants with a substantially reduced plastid genome size. We show that the lack of the IR results in a mildly reduced plastid ribosome number, suggesting a gene dosage benefit from the duplicated presence of the ribosomal RNA operon. Moreover, the IR deletion plants contain an increased number of plastid genomes, suggesting that genome copy number is regulated by measuring total plastid DNA content rather than by counting genomes. Together, our findings (1) demonstrate that the IR can enhance the translation capacity of the plastid, (2) reveal the relationship between genome size and genome copy number, and (3) provide a simplified plastid genome structure that will facilitate future synthetic biology applications.

Two approaches to prepare cationic lignin‐based adsorbents for efficient removal of phosphate ion from wastewater

AbstractIn this work, two types of cationic lignin‐based adsorbents (AL‐METAC and AL‐GTA) were prepared through free radical polymerization or etherification reaction of alkali lignin with 2,3‐epoxypropyl‐3‐trimethylammonium chloride or methylacrylloxyethyl trimethyl ammonium chloride (METAC). The contents of quaternary ammonium groups in the adsorbents were adjusted by changing the dosages of 2,3‐epoxypropyl‐3‐trimethylammonium chloride and METAC to fabricate the adsorbents with excellent adsorption capacity. The structures, aqueous solubility, and physical properties of adsorbents were analyzed. Meanwhile, the effects of adsorbents dosage, pH value of solution, temperature, and ionic strength on the adsorption capacity of adsorbents were also analyzed. These two types of adsorbents exhibited outstanding affinity for phosphate, with a maximum removal efficiency of 51.8 and 73.2 mg/g, respectively. The adsorption processes followed pseudo‐second‐order and Langmuir models well. In addition, the AL‐GTA exhibited higher removal efficiency than AL‐METAC. Moreover, the AL‐METAC and AL‐GTA still retained 69.7% and 69.0% adsorption capacity after four times regeneration. The fabricated lignin‐based adsorbents have potential applications in the removal of phosphate from wastewater, which would promote the high‐value application of lignin.

Preparation and property studies of ferric sulfoaluminate cement based on Bayer red mud and phosphogypsum.

The Bayer red mud (RM) and phosphogypsum (PG) accumulation have caused significant environmental contamination. However, practical and effective resource utilization technologies are still lacking currently. This work aims to develop ferric sulfoaluminate cement (FSAC) employing low-cost materials including Bayer red mud, phosphogypsum, and other materials. This method effectively improves the utilization rate of Bayer red mud and phosphogypsum. Under the premise of ensuring the performance of FSAC, the utilization rate of solid waste can reach up to 48.56%. The effects of different red mud dosages on cement mineral formation, workability, and mechanical properties are investigated. Then, untreated phosphogypsum is adopted as a retarder for FSAC, and the hydration process, working properties, mechanical properties, types of hydration products, and morphology of FSAC are explored. The results suggest that the crystal transformation of Ye'elemite is promoted with the increase of Bayer red mud content. Cubic crystal system Ye'elemite with higher hydration activity is generated, which increases the early strength of cement but greatly reduces the setting time, hindering the later strength growth. Untreated phosphogypsum can effectively delay the early hydration process of FSAC, prolong the setting time of cement, and increase the strength of FSAC in the later stage. When the dosage of Bayer red mud and phosphogypsum is 17.64% and 9.21%, respectively, with phosphogypsum dosage of 20%, the prepared FSAC has satisfactory mechanical properties, and the 3-day and 90-day compressive strengths are 34.6 MPa and 57.1 MPa, respectively. In addition, the study of heavy metal leaching indicates that the FSAC prepared by Bayer red mud, phosphogypsum, and other raw materials will generate no environment pollution, and the solidification of heavy metal elements in the cement slurry is superior.

Preparation of microfibrillated cellulose by in situ and one step method using calcium hydroxide as swelling and grinding agent

Abstract Calcium hydroxide was used as a swelling agent and grinding aid to grind together with cellulose raw materials to prepare microfibrillated cellulose (MFC). Carbon dioxide was introduced to obtain MFC coated with calcium carbonate (CMFC). The effect of calcium hydroxide dosage on the fibrillation process of cellulose materials and the characteristics of MFCs and CMFCs were studied. Results show that when the dosage of calcium hydroxide was 5 % (based on cellulose materials), calcium hydroxide could be completely dissolved in water and had a swelling effect on cellulose materials. When the dosage reached 10 %, undissolved calcium hydroxide particles could serve as grinding media to assist in the fibrillation of cellulose materials. When the dosage exceeded 50 %, the auxiliary grinding effect of calcium hydroxide was more obvious. After accelerated carbonation, the generated calcium carbonate nanoparticles were coated on the surface of MFC, which increased its viscosity and decreased water retention value. The presence of calcium carbonate also facilitated the concentration, redispersion, and drying of MFC. The pretreatment, mechanical fibrillation, and accelerated carbonation were carried out in the same equipment without the need for heating or washing. Therefore, this study provides a in situ and one step method for the preparation of MFC.

Assessment of effects of duration and dosage of Amlodipine on gingival health - A Prospective Study

Objectives: Calcium channel blockers are one of the most commonly used drugs for the management of cardiovascular disorders and are known for causing gingival overgrowth as an adverse effect. Disfiguring gingival overgrowth triggered by this medication is not only esthetically displeasing but also often impairs nutrition and access to oral hygiene, resulting in increased susceptibility to oral infection, caries, and periodontal diseases. The present study aimed to correlate the incidence of the extent of gingival enlargement in hypertensive patients receiving amlodipine and also a correlation of the extent of gingival enlargement with the dosage and duration of intake of Amlodipine. Materials and Methods: Hypertensive patients attending the outpatient of the Department of Oral Medicine and Radiology were selected for the study. A detailed history of the subjects was recorded for single or multiple drug usage, including the intake of amlodipine medications for hypertension, the dose and duration of the drug usage, following which a clinical examination was performed to evaluate the grades of gingival enlargement and local factors affecting the same. Results: The majority of the patients (81%) received 5 mg of amlodipine medication, and more than 40% of patients were receiving amlodipine for more than one year. More than 50% of patients had grade 2 gingival enlargement. There was a significant correlation between gingival enlargement and amlodipine dosage. Also noted was an association between gingival enlargement and duration of receiving amlodipine. Conclusion: Even with a minimal dose of amlodipine, significant gingival enlargement is seen; hence, regular follow-up with a suitable dental evaluation referral for examining gingival and periodontal status becomes imminent. Therefore, dental professionals need to identify and then guide the patient to seek the necessary medical intervention for the same.

Efficient removal of heavy metal ions by modified cellulose prepared from rice husk: Equilibrium isotherms, Kinetics and desorption studies

The cellulose acetate was prepared from the naturally occurring cellulose extracted from rice husk. It was then characterized using FTIR, XRD, SEM/EDS, TEM and BET and the results were connected to their potential applications in the elimination of heavy metal ions. Differential pulse voltammetry was used for quantitative study of heavy metal ions. An adsorption experiment was conducted to study the effect of temperature, initial concentration, adsorbent dosage, pH and contact time on the adsorption capacity of cellulose acetate. The results of the adsorption experiment showed that the removal of metal ions from adsorbent was a pH-dependent, reaching its maximum adsorption capability at pH of 5-6. Adsorption process was effective with adsorbent dosage was 10±0.1 mg/mL and the temperature was kept at 303K. The adsorption properties of cellulose acetate can be effectively described by pseudo-second-order kinetic with lower error function value and adsorption isotherm such as Freundlich and Temkin adsorption model at 50 min contact time and 50±0.1 mg/L initial concentration. The thermodynamic parameters were investigated, they shows adsorption is favorable at low temperatures. Desorption and re-adsorption of the heavy metals were also studied. Cellulose acetate still retains its adsorption efficiency up to 6th cycles of adsorption.

Rehabilitation success after psychosomatic rehabilitation as afunction of psychotherapy dose

Increasing the effectiveness of psychosomatic rehabilitation by prolonging the treatment is a subject of controversial debate. The number of sessions over time defines the dosage in psychotherapy. While the dose-response model assumes an optimal therapy dose, the good-enough level model assumes acorrelation of the rate of change with the total sessions. Arandomized control group study was conducted to investigate the extent to which an adaptive therapy concept with atwo-week intensive phase and early intervention could increase rehabilitation success. A total of 494 rehabilitants between the ages of 21 and 64 (47% women) who completed aclassical or an integrative psychosomatic rehabilitation at the Rehazentrum Oberharz between 2020 and 2022 were analysed. Rehabilitation success was mapped by the Reliable Change Index of individual symptom reduction (depression severity or psychological and somatoform disorders) and as asocio-medical parameter (physician's assessment of potential work ability (WA) after twoweeks). Two-factorial ANOVAs and hierarchical binary logistic regressions were calculated, and sick leave before rehabilitation was statistically controlled. Dosage showed no effect on symptom reduction (p = 0.29) and potential WA after twoweeks (p = 0.90). However, when stratified by disease severity, there was amean effect of dosage (p = 0.05) and twice the probability of WA after twoweeks (odds 2.13; p = 0.01) for those with mild disease at the start of measure (p = 0.05). In the early stages of an affective disorder, early and intensified intervention can counteract the chronification of mental disorders.

In vitro induction of tetraploids and their phenotypic and transcriptome analysis in Glehnia littoralis

BackgroundGlehnia littoralis is a medicinal and edible plant species having commercial value and has several hundred years of cultivation history. Polyploid breeding is one of the most important and fastest ways to generate novel varieties. To obtain tetraploids of G. littoralis in vitro, colchicine treatment was given to the seeds and then were screened based on morphology, flow cytometry, and root tip pressing assays. Furthermore, transcriptome analysis was performed to identity the differentially expressed genes associated with phenotypic changes in tetraploid G. littoralis.ResultsThe results showed that 0.05% (w/v) colchicine treatment for 48 h was effective in inducing tetraploids in G. littoralis. The tetraploid G. littoralis (2n = 4x = 44) was superior in leaf area, leaf thickness, petiole diameter, SPAD value (Chl SPAD), stomatal size, epidermal tissues thickness, palisade tissues thickness, and spongy tissues thickness to the diploid ones, while the stomatal density of tetraploids was significantly lower. Transcriptome sequencing revealed, a total of 1336 differentially expressed genes (DEGs) between tetraploids and diploids. Chromosome doubling may lead to DNA content change and gene dosage effect, which directly affects changes in quantitative traits, with changes such as increased chlorophyll content, larger stomata and thicker tissue of leaves. Several up-regulated DEGs were found related to growth and development in tetraploid G. littoralis such as CKI, PPDK, hisD and MDP1. KEGG pathway enrichment analyses showed that most of DEGs were enriched in metabolic pathways.ConclusionsThis is the first report of the successful induction of tetraploids in G. littoralis. The information presented in this study facilitate breeding programs and molecular breeding of G. littoralis varieties.

Effects of Liquidambar Orientalis Oil on Liver and Kidneys in Heathy Wistar Rats

Background: Nowadays, the tendency towards alternative herbal therapies has increased due to the side effects of drugs. However, since the contents, method of use, dosage and toxic effects of herbal products are not fully known, undesirable situations are occasionally encountered. However, there are many experimental studies on the cytotoxicity of L. orientalis oil, most of these studies are in vivo modelling. In this study, the cytotoxic effects of L. orientalis oil on the liver and kidneys were investigated in healthy rats by oral administered. Methods: The study material consisted of 18 female Wistar albino rats (190-280 g) aged 8-10 weeks. All animals were housed under optimal temperature, light and humidity conditions and fed with normal rat pellet food ad libitum. Housing conditions were checked daily. Three groups were organized as L. orientalis oil, olive oil and control group, respectively. Each group consisted of 6 rats. L. orientalis oil group: L. orientalis oil (150 mg/kg) dissolved olive oil (0.6 mL). Olive oil group: Olive oil (0.6 mL). Control group: Empty gavage. The entire trial was performed by intragastric gavage once a day for 14 days. Result: The obtained data showed that serum biochemical parameters remained within normal ranges in oral use of Liquidambar orientalis oil (150 mg/kg) and did not show any difference with the control and olive oil groups. No pathological changes related to cytotoxicity were found in the samples taken from liver and kidney tissues.

Doubling down on dosage: exploring the interplay between dosage effects, antisocial traits, treatment attitudes, and recidivism-related therapy outcomes

Purpose Studies evaluating the external validity of theoretically informed (risk-need-responsivity [RNR]) cognitive behavioral therapy (CBT) programs have not systematically assessed antisocial personality traits as a source of variability in outcomes. The purpose of this brief report is to examine antisocial traits as a potential source of variability in outcomes. Design/methodology/approach Using longitudinal, program-evaluation data (a sample of incarcerated men who were exposed to RNR-informed CBT), the authors examined how antisocial personality traits, attitudes toward treatment and dosage impacted treatment outcomes. A linear regression assessed the relationship between antisocial personality traits and attitudes toward treatment. A latent profile analysis identified participants with elevated antisocial traits and negative attitudes toward treatment. Treatment dosage groups (0, 5, 10 and 15 weeks) were used to assess treatment response per pro-criminal attitudes, skills and rates of recidivism. Findings Antisocial traits predicted negative attitudes toward treatment. Elevated antisocial traits and negative treatment attitudes predicted less change in criminal attitudes among those who completed 15 weeks of treatment; higher dosage did not significantly improve rates of recidivism. Variable-centered post hoc analyses largely corroborated these findings. These results suggest RNR-informed CBT may need to be modified for justice-involved persons with elevated antisocial traits. Originality/value Few studies have empirically examined the sources of variability in treatment effects for justice-involved persons with antisocial personality traits. This brief report provides a structured examination of factors that may impact treatment outcomes in this population, and therefore aims to inform future research on the effectiveness of empirically supported interventions for people in the legal system.

Effect of l-arginine compared to placebo on sexual function in women with major depressive disorder: a randomized controlled trial

BackgroundWhile some evidence suggests that l-arginine may improve sexual function and alleviate depression, it has not been investigated in women with depression to assess both its effects on the depression and sexual function concurrently.MethodsPatients who had received a diagnosis of major depressive disorder, as determined by predetermined inclusion and exclusion criteria, were enrolled in this triple-blind clinical trial. Patients were divided into two groups: group A, received L-arginine 1 gram twice daily, and group B, received a placebo for four weeks. They were evaluated at baseline, after four and eight weeks with the Hamilton Depression Rating Scale (HDRS), and Rosen’s questionnaire or Female Sexual Function Index (FSFI).ResultsA decrease in the severity of depression was observed in all patients, which was determined due to Hamilton’s questionnaire (P-value < 0.001). During the time in group A, FSFI increased. Based on the FSFI questionnaire, they had improvement in some domains, including the lubrication index and orgasm index, which significantly changed in the eighth week compared to the baseline (P-value < 0.05). However, these two indicators did not change statistically significantly compared to the placebo group.ConclusionL-arginine supplementation can improve sexual function, particularly lubrication and orgasm, and mood in women with depression, with minimal side effects observed. Additional research is necessary to validate these results by examining the effects of higher dosages, extended durations, and larger populations of depressed patients.Trial registrationIranian Registry of Clinical Trial: IRCT20100127003210N26.

Lead (Pb) Sorption Kinetics by Clay Minerals: Bentonite and Zeolite

Background: Heavy metal pollution chiefly lead (Pb) causes various environmental disequilibrium and health hazards. Immobilization of lead (Pb) usingclay minerals is cost effective for metal remediation due to their higher surface area and negative charges. Methods: This study was taken up to assess the Pb removal potentials of bentonite and zeolite from contaminated water and to study the effect of sorbent dosage, initial Pb2+ concentrations and incubation time intervals on Pb adsorption and desorption was studied. Result: Zeolite was effective in immobilising Pb (78.0%) than bentonite (70.9%) which increased with increasing sorbent dosage and time intervals. The pseudo second-order kinetic model described the Pb adsorption precisely. Chemisorption was the dominant mechanism operating in aqueous solution system, hence, it could be concluded that zeolite can be utilized as an efficient sorbent for wastewater treatment.

Novel progressive deep learning algorithm for uncovering multiple single nucleotide polymorphism interactions to predict paclitaxel clearance in patients with nonsmall cell lung cancer

AbstractBackgroundThe rate at which the anticancer drug paclitaxel is cleared from the body markedly impacts its dosage and chemotherapy effectiveness. Importantly, paclitaxel clearance varies among individuals, primarily because of genetic polymorphisms. This metabolic variability arises from a nonlinear process that is influenced by multiple single nucleotide polymorphisms (SNPs). Conventional bioinformatics methods struggle to accurately analyze this complex process and, currently, there is no established efficient algorithm for investigating SNP interactions.MethodsWe developed a novel machine‐learning approach called GEP‐CSIs data mining algorithm. This algorithm, an advanced version of GEP, uses linear algebra computations to handle discrete variables. The GEP‐CSI algorithm calculates a fitness function score based on paclitaxel clearance data and genetic polymorphisms in patients with nonsmall cell lung cancer. The data were divided into a primary set and a validation set for the analysis.ResultsWe identified and validated 1184 three‐SNP combinations that had the highest fitness function values. Notably, SERPINA1, ATF3 and EGF were found to indirectly influence paclitaxel clearance by coordinating the activity of genes previously reported to be significant in paclitaxel clearance. Particularly intriguing was the discovery of a combination of three SNPs in genes FLT1, EGF and MUC16. These SNPs‐related proteins were confirmed to interact with each other in the protein–protein interaction network, which formed the basis for further exploration of their functional roles and mechanisms.ConclusionWe successfully developed an effective deep‐learning algorithm tailored for the nuanced mining of SNP interactions, leveraging data on paclitaxel clearance and individual genetic polymorphisms.

Optimisation of Synchronous Grouting Mix Ratio for Shield Tunnels

During shield construction in underground spaces, synchronous grouting slurry is poured between the surrounding rock and tunnel lining to ensure stability. For synchronous grouting slurries, few studies have investigated the relationship between the rheological parameters and physical properties, grout-segregation mechanism, and anti-segregation performance. Therefore, we explored the relationships between the slurry rheological parameters, segregation rate, and bleeding rate. Cement, sand, fly ash, and bentonite were used to prepare the slurry, and the effects of different polycarboxylate water-reducing agents and dispersible latex powder dosages were studied. The rheological parameters of 16 groups of uniformly designed slurries were tested, and the data were fit using the Herschel–Bulkley model. The optimal mix ratio lowered the slurry segregation rate, and its rheological behaviour was consistent with the Herschel–Bulkley fluid characteristics. High-yield-shear-stress synchronous grouting slurries with high and low viscosity coefficients were less likely to bleed and segregate, respectively. The optimised slurry fluidity, 3 h bleeding rate, 24 h bleeding rate, segregation rate, coagulation time, and 28 days compressive strength were 257.5 mm, 0.71%, 0.36%, 3.1%, 6.7 h, and 2.61 MPa, respectively, which meet the requirements of a synchronous grouting slurry of shield tunnels for sufficiently preventing soil disturbance and deformation in areas surrounding underground construction sites.

Vibro-tactile stimulation of the neck reduces pain in people with cervical dystonia: a proof-of-concept study.

Pain is a common non-motor symptom in patients with cervical dystonia (CD), severely impacting their quality of life. The pathophysiology of CD is incompletely understood but it involves altered processing of proprioceptive and pain signals. The purpose of this proof-of-concept study was to determine if vibro-tactile stimulation (VTS)-a non-invasive form of neuromodulation targeting the somatosensory system-can modulate neck pain in people with CD. In a multi-center study, 44 CD patients received VTS to sternocleidomastoid and/or trapezius muscles for up to 45min under 9 different stimulation conditions that either targeted a single or a pair of muscles. The primary outcome measure was a perceived pain score (PPS) rated by participants on a 100-point analogue scale. During VTS, 29/44 (66%) of participants experienced a reduction in PPS of at least 10% with 17/44 (39%) reporting a reduction in pain of 50% or higher. After VTS cessation, 57% of participants still reported a 10% or higher reduction in PPS. Effects were significant at the group level and persisted for up to 20min post-treatment. No distinct optimal stimulation profiles were identified for specific CD phenotypes. Clinical markers of disease severity or duration did not predict the degree of VTS-induced pain reduction. This proof-of-concept study demonstrates the potential of VTS as a new non-invasive therapeutic option for treating neck pain associated with CD. Further research needs to delineate optimal dosage and long-term effects.

Metagenome-enabled models improve genomic predictive ability and identification of herbivory-limiting genes in sweetpotato

Abstract Plant-insect interactions are often influenced by host-/insect-associated metagenomic community members. Relative abundance of insects and the microbes that modulate their interactions were obtained from sweetpotato (Ipomoea batatas) leaf-associated metagenomes using quantitative reduced representation sequencing and strain/species level profiling with the Qmatey software. Positive correlations were found between whitefly (Bemisia tabaci) and its endosymbionts (Candidatus Hamiltonella defensa, Candidatus Portiera aleyrodidarum, and Rickettsia spp.) and negative correlations with nitrogen-fixing bacteria that implicate nitric oxide in sweetpotato-whitefly interaction. Genome-wide associations using 252,975 dosage-based markers, and metagenomes as a covariate to reduce false positive rates, implicated ethylene and cell wall modification in sweetpotato-whitefly interaction. The predictive abilities (PA) for whitefly and Ocypus olens abundance were high in both populations (68-69% and 33.3-35.8%, respectively, and 69.9% for Frankliniella occidentalis). The metagBLUP (gBLUP) prediction model, which fits the background metagenome-based Cao dissimilarity matrix instead of the marker-based relationship matrix (G-matrix), revealed moderate PA (35.3-49.1%) except for O. olens (3-10.1%). Significant gain in PA after modeling the metagenome as a covariate (gGBLUP, ≤11%) confirms quantification accuracy and that the metagenome modulates phenotypic expression and might account for the missing heritability problem. Significant gains in PA were also revealed after fitting allele dosage (≤17.4%) and dominance effects (≤4.6%). Pseudo-diploidized genotype data underperformed for dominance models. Including segregation distorted loci (SDL) increased PA by 6-17.1%, suggesting traits associated with fitness cost might benefit from the inclusion of SDL. Our findings confirm the holobiont theory of host-metagenome co-evolution and underscore its potential for breeding within the context of GxGxE interactions.

Construction of a GTP regeneration system by regulating gene expression in the pathway

Guanosine 5′-triphosphate (GTP) provides precursors for the biological synthesis of various valuable compounds. However, the insufficient supply of GTP is often encountered when engineering microbes for the synthesis of certain products, which results in metabolic imbalance and unsatisfying product yield. To tackle this issue, a general strategy for improving GTP regeneration was developed in this study. The effects of dosage and combination strategy of genes related to GTP synthesis were examined to pinpoint the most critical genes influencing GTP production in Escherichia coli. A regeneration system of GTP was derived by the overexpression of genes guaA and guaB, the intracellular GTP concentration of which improved by 81%. To further verify the applicability of the engineered GTP regeneration system on strengthening the product synthesis, it was applied to the production of riboflavin and colanic acid that required GTP as a precursor. It turned out that the titer of riboflavin was increased by 95.8% and the titer of colanic acid was increased by 44%. The GTP regeneration system developed here can also be applied to other products that use GTP as a precursor or require GTP as a cofactor.

Effectiveness of Bamboo Leaf Silica Applied with Nanosprayer and Growing Media on Yield of Red Beetroot (Beta vurgaris L.)

Silica protects plants from abiotic stress. Planting media provides a place to grow and nutrition for plant growth. The research aims to study the effect of bamboo leaf silica dosage and growing media on the yield of red beets cultivated in the lowlands. The research was designed using a completely randomized factorial design (CRD) with two treatment factors. The first factor is the dose of bamboo leaf silica fertilizer (0 ppm, 0.15 ppm, 0.30 ppm, 0.45 ppm, 0.60 ppm). The second factor is the growing media (soil growing media; soil growing media + goat manure, and soil growing media + goat manure + husk charcoal). Research results: bamboo leaf silica dosage (0.3 ppm, 0.45 ppm and 0.60 ppm) affects the chlorophyll b and total chlorophyll. Growing media soil + goat manure + husk charcoal affects the length of red beet plants, number of leaves, diameter and length of red beetroots, wet weight and dry weight of red beetroots. Combination of growing media treatment (soil + goat manure + husk charcoal) with all doses of bamboo leaf silica increased the chlorophyll a, chlorophyll b and total chlorophyll. The sugar content of red beetroots was not influenced by the dose of bamboo leaf silica or the growing medium. Keywords: Chlorophyll, Husk Charcoal, Manure, Soil.

Investigation on the anti-carbonation properties of alkali-activated slag concrete: Effect of activator types and dosages

In this paper, three alkaline activators, namely sodium hydroxide (SH), calcium oxide and sodium carbonate (COSC), calcium hydroxide and sodium sulfate (CHSS), and the influence of different alkali equivalents on the carbonation resistance of alkali-activated slag concrete (AASC) were investigated. By testing the mechanical properties at different carbonation ages of AASC with three types of activators at varying alkali equivalents (4%, 6%, and 8%), along with the changes in carbonation depth, this study aims to characterize hydration products and porosity through microstructural analysis. The objective is to explain the mechanism by which carbonation affects the AASC structure. The findings showed that the carbonation rate (i.e., the growth rate of the carbonation depth) of AASC was CHSS > COSC > SH when the exciter dosages were the same, and the carbonation rate of all samples tended to slow down as the alkali components increased. Calcite and spherulite were the calcium carbonate morphologies after SH, COSC, and CHSS carbonation according to XRD, TG/DSC, and pore structure tests; the calcium carbonate content decreased with increasing alkali equivalent after carbonation. Since the pore-increasing effect of carbonation due to the destruction of C–S–H is weaker than the filling effect produced by calcium carbonate, the total pore volume of SH, COSC, and CHSS decreased due to the activator effect after carbonation. Specifically, the calcium carbonate created by carbonation repairs pores and cracks of matrix, but its presence also reduces the calcium hydroxide concentration, leading to a decrease in the alkalinity of the pore solution, which disrupts the structure of the hydration products and loosens the matrix. The focus is on which aspect is more decisive. Interestingly, small pores however decreased, while there was an increase in larger pore sizes resulting in a change in pore size distribution. However, this negative impact on pore distribution decreased with increasing alkali dosage.

Synthesis and characterisation of K2CO3-activated carbon produced from distilled spent grains for the adsorption of CO2.

Activated carbon was prepared from distilled spent grains (DSG) using K2CO3 activation and chitosan modification. The effects of activator dosage, activation temperature, and the incorporation of chitosan as a nitrogen source on the adsorption performance were studied in this paper. The activated carbons were characterised by scanning electron microscopy, X-ray photoelectron spectroscopy, and nitrogen and carbon dioxide gas adsorption. Under the optimal conditions, the BET-specific surface area, total pore volume, and microporous volume of the activated carbon were as high as 1142 m2/g, 0.62 cm3/g, and 0.40 cm3/g, respectively. Chitosan was used as the nitrogen source, and surface modification was carried out concurrently with the K2CO3 activation process. The results revealed a carbon dioxide adsorption capacity of 5.2 mmol/g at 273.15 K and 1 bar without a nitrogen source, which increased to 5.76 mmol/g after chitosan modification. The isosteric heat of adsorption of CO2 all exceed 20 kJ/mol, hinting at the coexistence of both physisorption and chemisorption. The adsorption behaviour of the DSG-based activated carbon can be well-described by the Freundlich model.