Absorption Ratio Research Articles

Starch nanoparticles with predictable size prepared by alternate treatments of ball milling and ultrasonication

In this study, starch nanoparticles (SNPs) were prepared by alternate treatments of liquid nitrogen ball milling and ultrasonication. The impact, shear and friction forces produced by ball milling, and acoustic cavitation and shear effects generated by ultrasonication disrupted starch granules to prepare SNPs. The SNPs possessed narrow particle size distribution (46.91–210.52 nm) and low polydispersity index (0.28–0.45). Additionally, the SNPs exhibited the irregular fragments with good uniformity. The relative crystallinity decreased from 34.91 % (waxy corn starch, WCS) to 0–25.91 % (SNPs), and the absorbance ratios of R1047/1022 decreased from 0.81 (WCS) to 0.60–0.76 (SNPs). The SNPs had lower thermal stability than that of WCS, characterized by a decrease in Td (temperature at maximum weight loss) from 309.39 °C (WCS) to 300.39–305.75 °C (SNPs). Furthermore, the SNPs exhibited excellent swelling power (3.48–28.02 %) and solubility (0.34–0.97 g/g). Notably, oil absorption capacity of the SNPs (9.77–15.67 g/g) was rather greater than that of WCS (1.33 g/g). Furthermore, the SNPs possessed the lower storage modulus (G′), loss modulus (G″) and viscosity than that of WCS. The SNPs with predictable size and high dispersion capability prepared in this study lay a foundation for expanding the application of SNPs.

The impact of the coupling relationship between projectile size and yarn dimension on the ballistic performance of plain weave fabric

Aramid fibers, due to their relatively high inter-yarn friction, high strength, high modulus, and other characteristics, have become a typical representative of flexible anti-ballistic materials in modern warfare. Current research on the anti-penetration of aramid fabrics mostly focuses unilaterally on the structure and performance of aramid fabrics or the shape and size of projectiles, with fewer studies on the coupled effect of both on ballistic performance. This study analyzes how the coupling relationship (or size effect) between the projectile and fiber bundle dimensions affects the fabric ballistic performance from a mesoscopic scale perspective. Taking plain weave aramid fabric as the research object, considering different diameter projectiles, through a large number of ballistic impact tests and numerical simulations, parameters such as ballistic limit velocity, average energy absorption of fabric, and specific energy absorption ratio (average energy absorption of fabric divided by projectile cross-sectional area) are obtained for ballistic performance analysis. The influence law of projectile size on the ballistic performance of high-performance fabrics is as follows: The relative range of fitted ballistic limit velocity at different target positions gradually decreases and then stabilizes as the projectile diameter increases, indicating that the fabric structure effect gradually disappears at a projectile diameter of 12 mm; The average ballistic limit velocity at three impact positions, P1, P2, and P3, provides the corresponding ballistic limit velocity for 1000D aramid fabric, which increases with projectile diameter but the rate of increase slows down at an inflection point, which in this study occurs where the fabric structure effect nearly disappears at a projectile diameter of 12 mm; The energy absorption ratio increases and then decreases as the projectile diameter increases from 4 mm to 20 mm, reaching a peak at the diameter of 12 mm due to the gradual disappearance of the fabric structural effect. The projectile diameter of 12 mm corresponds to the coupling size of 11.159, which provides a size design reference for the macroscopic-based continuum models of aramid plain weave fabrics.

Invasion of Trifolium repens L. aggravated by biodegradable plastics: adjustable strategy for foraging N and P

The invasion of alien plant and the pollution caused by soil microplastics have emerged as significant ecological threats. Recent studies have demonstrated aggravating effect of non-biodegradable microplastics on plant invasion. However, the impact of biodegradable microplastics (BMPs) on plant invasion remains unclear. Therefore, it is imperative to explore the impact of BMPs on plant invasion. In this study, a 30-day potting experiment with Trifolium repens L. (an invasive plant) and Oxalis corniculata L. (a native plant) was conducted to evaluate the influence of BMPs on T. repens's invasion. The findings revealed that BMPs results in a reduction in available N and P contents, thereby facilitating the colonization of arbuscular mycorrhizal fungi on T. repens 's roots. Consequently, T. repens adjusted its N and P foraging strategy by increasing P absorption ratio, and enhancing the accumulation of N and P in leaves. This ultimately led to the decrease of relative neighbor effect index of T. repens, indicating an aggravated invasion by T. repens. This study significantly enhances and expands the understanding of mechanisms by which microplastics aggravate plant invasion.

Growth and characteristics of bicolor Fe-doped MgAl2O4 crystals

Bicolor Fe-doped MgAl2O4 crystals were successfully grown using the floating zone technique. These bicolor crystals were grown with composition ratios of MgO to Al2O3 (x) ranging from 0.3 to 1.0 and Fe2O3 concentrations of 0.1 mol%–2.0 mol%. Their growth process involved changing the O2 concentrations in the growth atmospheres: 0 vol% O2–100 vol% Ar, 50 vol% O2–50 vol% Ar, and 100 vol% O2–0 vol% Ar. The color of the resultant crystals changes with the growth conditions employed. Crystals manifested in six colors: pink, green, purple, violet, blue, yellow, and brown, based on the combination of Fe2O3 concentrations, O2 concentrations, and x. Additionally, bicolor crystals could be grown by suddenly changing the O2 concentration in the growth atmosphere, while tri-color crystals could be achieved through gradual alterations in the O2 concentration in the growth atmosphere. The color change of the bicolor crystals is considered to be caused by the change in the optical absorption ratio at λ = 455 (blue light) and λ = 550 nm (green light) due to the change in the concentration ratio of Fe2+ and Fe3+ in the crystal.

Formulation & Evaluation of Anti Migrane Mouth Dissolving Tablet

The objective of this study is to improve the safety, efficacy, and rate of action of the existing molecule by utilising novel techniques to the administration of medication. This will be accomplished by the application of novel approaches. Orally disintegrating pills containing rizatriptan benzoate were made by the direct compression technique in order to provide migraine sufferers with a more expedient manner of gaining relief from their condition. For the purpose of this inquiry, a 32-factororial design method was utilised, and eight different formulations were examined for each of the super disintegrants that were explored. There were a number of tests that were performed on the batches of tablets that were manufactured. These tests included weight variation, hardness, friability, wetting time, invitro dispersion time, drug content, and invitro dissolution. A UV spectrophotometric approach that is easy, sensitive, rapid, accurate, cost-effective, and repeatable was created in order to identify the dose form of Rizatriptan Benzoate tablets. This method was designed in order to determine the dose form. It has been determined that rizatriptan benzoate has the maximum absorbance at a wavelength of 225 nm, and its molar absorption is measured to be 1.619 Ao. According to Beer's law, the application of the law was observed between 1 and 10 μg/ml. In order to validate the conclusions of the investigation, statistical analysis and recovery studies were carried out. In order to validate the method, a number of various criteria were utilised. These criteria included linearity, accuracy, limit of detection (LOD), limit of quantification (LOQ), Sandell's sensitivity, and specificity were among the criteria that were utilised. The practice of determining the regular dosage of Rizatriptan Benzoate in both tablet and bulk forms was found to be one that is accurate and precise via the utilisation of the preferred method. This was identified through the utilisation of the recommended method. A time period ranging from fifteen to thirty seconds was required for the optimised formulation to be distributed throughout the body. Furthermore, it demonstrated a greater water absorption ratio and released 99.60% of the medication over a period of two minutes and fifteen seconds. This was in addition to everything else that it shown.

Dual-modified starch micelles as nanocarriers for efficient encapsulation and controlled release of walnut-derived active peptides

Hydrophilic and hydrophobic modified nanomicelles might be more conducive to passage of the gastrointestinal barrier than walnut peptide (WP). In this study, a novel double modified starch polymer, SB–CST–DCA, was synthesized by grafting sulfabetaine (SB) and deoxycholic acid (DCA) onto corn starch (CST) molecules through etherification and esterification. The modification mechanism was discussed to determine its chemical structure, morphological properties, and thermal stability. Peptide-loaded nanomicelles (SB–CST–DCA–WP) were prepared using WP as the core material. The encapsulation efficiency and peptide loading amount reached 76.90 ± 1.52% and 18.27 ± 0.53%, respectively, with good stability and pH-responsive release behavior observed to effectively control WP release and enhance its antioxidant activity. The composite exhibited safety, non-toxicity, and good blood compatibility at concentrations below 125 μg/mL. Duodenum was identified as the main absorption site with an absorption ratio of 41.16 ± 0.36%.

Insights into multi-component digestion and antioxidant release from plant protein-seaweed-based Maillard conjugate-MRP systems

Maillard conjugation to modify protein functionality results in the formation of a protein-polysaccharide complex. The resultant conjugate mixture is rich in different Maillard reaction products (MRP) and unreacted components. The investigation pertaining to the digestion and intestinal fate of these components is challenging due to the multitude of effects and interactions between different components. This study attempts to understand gastrointestinal behaviour and diffusion/release patterns of different components from a complex system made of the amaranth-Gracilaria seaweed system. Data acquired from in-vitro INFOGEST protocol and intestinal dialysis absorption model were used to investigate the amino acid release and antioxidant diffusion during different phases of digestion. The analysis suggests a significant improvement in the radical scavenging capacity of overall antioxidants released from the conjugate-MRP system compared to that of amaranth protein alone based on different antioxidant assays (DPPH, FRAP, ICred) during each stage of digestion. The permeability and overall intestinal absorption ratio of antioxidants through a dialysis membrane shows an improvement of up to 55 % compared to that of the plant protein. Moreover, amino acid and phyto-compounds release patterns of the conjugate-MRP system exhibit selective shielding effects towards the gastric phase, which can potentially be investigated for targeted release of bioactive compounds.

Optimization of preparation conditions and performance of a new degradable soil water retaining agent

Using polyaspartic acid (PAsp) and bentonite (BT) as the main raw materials, a new type of degradable soil water retaining agent (PAsp-AA/BT) was synthesized by microwave radiation. The optimum synthesis conditions and comprehensive properties of PAsp-AA/BT were discussed and the structure and surface characteristics of PAspsp-AA/BT were characterized by FTIR, SEM, XRD and TGA in the paper. The results showed that the optimum synthesis conditions of PAsp-AA/BT were as follows: the dosages of polyaspartic acid (PAsp), bentonite (BT), initiator potassium persulfate, crosslinking agent N,N′-methylene bisacrylamide was 5, 3, 0.3, 0.03%, respectively, the neutralization degree of acrylic acid was 75%, and the microwave power was 490W. Under this condition, the absorption ratio of the synthesized PAspsp-AA/BT in deionized water and 0.9% NaCl solution was 953 and 164 g/g, respectively. The synthesized PAsp-AA/BT had a high water absorption rate, good water retention and repeated water absorption, and the degradation rate in soil within 30 days reached 32.75%, with good degradation effect. The analysis of SEM, FT-IR, XRD and TGA showed that: the surface of PAsp-AA/BT was rough and had obvious pore structure, which was conducive to the diffusion of water molecules; polyaspartic acid, bentonite and acrylic acid were polymerized; the cross-linking structure was formed between polyaspartic acid, bentonite and acrylic acid; the product of PASP-AA/BT had good thermal stability. This study provides a new soil water retaining agent, which is helpful for the better development of soil water retaining agent research.

Hydrogeochemical and GIS Analysis of Groundwater Quality for Drinking and Irrigation Purposes in Kuzhithuraiyar Sub-Basin, Kanniyakumari District, Tamil Nadu, India

A hydrogeochemical analysis was conducted to find the suitability of the groundwater for drinking and irrigation purposes in the Kuzhithuraiyar sub-basin, Kanniyakumari district, Tamil Nadu, India. 48 groundwater samples were collected from the different locations of the study area during both the pre- and postmonsoon periods. This study assesses the groundwater quality for drinking and irrigation purposes based on the analytical results, water quality index, Wilcox plot, and irrigation parameters such as electrical conductance, Kelly’s ratio, sodium absorption ratio values, magnesium hazards, bicarbonate, and the residual sodium carbonate index. The pH values ranged from 8.5 to 6.5, suggesting generally acceptable conditions. TDS concentrations range from 24 to 1277 mg/L, whereas EC values range from 37.50 to 1996 μS/cm. It is observed from the collected samples that the pre-monsoon water samples TDS’ values were exceeded the recommended TDS limits than postmonsoon samples. Water quality indices indicate that 50% of premonsoon samples and 48% of postmonsoon samples are suitable for drinking. In total, 10% of samples are admissible to a doubtful category before and after the monsoon, 6% are good to permissible during the monsoon, and 84% are good to permissible. Kelly’s ratio shows that 56% and 48% of samples collected during the post- and premonsoon are suitable for irrigation, respectively, whereas the remaining samples are not. Due to magnesium hazards, 40% and 44% of pre- and postmonsoon samples are not suitable for irrigation. Overall, the postmonsoon samples exceeded the permissible TDS limit (1000 mg/L) by 10% and the premonsoon samples by 6. 13% of samples obtained after the monsoon and 19% collected before the monsoon have a potential salinity greater than three, indicating that these samples are unacceptable. The sustaining water quality and mitigating possible hazards in the Kuzhithuraiyar sub-basin require continuous monitoring and focused measures.

On fused filament fabrication of PLA nanofiber reinforced PCL matrix-based smart porous scaffolds

In the past, studies were reported on polycaprolactone (PCL) and polylactic acid (PLA) nanofibers (NF)-based scaffolds for tissue engineering applications. But hitherto, little has been reported on the sensing capability of PLA-NF reinforced PCL composite (PPNC)-based smart porous scaffolds for online health monitoring (OHM) of joint strains/ tendon tears/ contusions/ rhabdomyolysis, etc. In this study, smart porous scaffolds (SPS) were fabricated by fused filament fabrication (FFF) using PPNC for OHM (of joint strains/ tendon tears/ contusions/ rhabdomyolysis, etc.) with tuneable sensing and mechanical properties. The results suggest that FFF parameters, zigzag fill pattern, 0.20 mm layer thickness, and 80 % infill percentage are the best-predicted settings for maximum yield stress (σymax) of SPS. Further, a vector network analyzer was used to ascertain the sensing capability of SPS. The resonance frequency (Rf) for PCL (virgin) and PPNC with minimum yield stress (σymin) and σymax were observed as 2.3021, 2.6008, and 2.4315 GHz respectively. The simulated return loss (S11), specific absorption ratio (SAR), and Rf for PCL (−10.7593 dB, 0.977 W/kg, and 2.6450 GHz), PPNC with σymin (−10.5737 dB, 1.437 W/kg and 2.3400 GHz) and PPNC with σymax (−10.9429 dB, 1.155 W/kg and 2.5050 GHz) indicate that experimental data is in good co-relation with the observed values. The results are supported by a scanning electron microscope and differential scanning calorimetry.

Tannic acid-crosslinked gelatin composite microspheres adsorbed with CQAS or Ca2+ for rapid hemostasis

In the case of massive blood loss due to natural disasters and wars, timely and rapid hemostasis is of great significance to improve the survival rate of injured people. Nevertheless, uncontrolled, noncompressible, and irregular bleeding wounds remain a giant challenge for rapid hemostasis. In this study, the tannic acid-crosslinked gelatin was first obtained by Michael addition reaction, and then the tannic acid-crosslinked gelatin composite microspheres (TGMs) were prepared by the emulsion cross-linking method. TGMs could significantly improve the water absorption and hemostatic performance compared with single component gelatin microspheres (GMs). Increasing the water absorption ratio and introducing blood coagulation factors into composite materials are simple and effective strategies to enhance the hemostatic properties. Therefore, chitosan quaternary ammonium salt (CQAS) and Ca2+ were electrostatic adsorbed to obtain two kinds of functional TGMs, which were respectively CQAS-absorbed TGMs (T2GMs-CQAS) and calcium ion-absorbed TGMs (T2GMs-Ca2+). Notably, T2GMs-CQAS, and T2GMs-Ca2+ could absorb water rapidly within 3 seconds, in addition, especially the water absorption ratio of T2GMs-CQAS could reach 2.95 times compared with GMs. Benefited from rapid water absorption, coagulation pathway activation, and red blood cells aggregation of T2GMs-CQAS and T2GMs-Ca2+, resulting in rapid blood coagulation in vitro. In addition, CQAS and Ca2+ provided strong and intrinsic antibacterial activity due to positive charge. Moreover, in the tail amputation and liver hemostatic models, T2GMs-CQAS and T2GMs-Ca2+ demonstrated superior hemostatic effects compared to commercial Yunnan Baiyao®. In conclusion, T2GMs-CQAS and T2GMs-Ca2+ have potential applications as hemostatic dressings in uncontrolled, noncompressible, and irregular bleeding wounds.

A Naked-Eye Colorimetric Ratio Method for the Selective and Sensitive Detection of L-Cys Based on a Silver Nanoflakes–Chromium (III) Ion System

As a necessary sulfhydryl amino acid, L-cysteine (L-Cys) maintains many physiological functions in the biological system. However, abnormal L-Cys levels can cause a variety of diseases. In our work, a highly sensitive and selective assay has been developed for sensing L-Cys using the morphological transformation of silver-based materials induced by Cr3+. In this sensing system, Cr3+ could etch the silver nanoflakes into silver nanoparticles, accompanied by a change in absorbance, which decreases at 395 nm, creates a new peak at 538 nm, and keeps increasing the absorbance with the addition of Cr3+ concentration. Meanwhile, under the naked eye, the solution color changes from bright yellow to dark purple. Because of the strong affinity between L-Cys and Cr3+, L-Cys could inhibit the induction of Cr3+ on silver-based materials, thereby preventing changes in the configuration, absorption spectrum, and color of silver-based materials. Taking advantage of this point, we can quantitatively detect the concentration of L-Cys. A linear relationship between the absorbance ratio (A538 nm/A395 nm) and L-Cys concentration was found in the range of 0.1–0.9 μM, and the detection limit was 41.2 nM. The strategy was applied to measure L-Cys spiked in beer and urine samples, with recovery from 93.80 to 104.03% and 93.33% to 107.14% and RSD from 0.89 to 2.40% and 1.80% to 6.78%, respectively. This detection strategy demonstrates excellent selectivity and sensitivity, which makes it a practical and effective method for the detection of L-Cys in real samples.

Matrix effect correction in active neutron interrogation for residual fissile mass assessment in radioactive waste drums

Metallic waste in the form of shells and nozzles remains following the reprocessing of spent fuel at La Hague plant (France). Before the final disposal, drums containing the waste are transported to the compaction facility where its volume is reduced by a factor of 5. With the objective of controlling the criticality/safety levels, an active neutron interrogation system at the entrance of the facility is used to assess the residual fissile mass remaining in the waste, which relies on prompt fission neutron detection (known as the differential die-away technique, DDA). The measured signal is proportionally linked to the fissile mass by a calibration coefficient. However, two effects can produce an inaccurate prediction. The number of induced fissions for the same fissile mass varies according to the waste matrix composition, particularly the neutron slow-down and absorption ratio. Secondly, the presence of fissile clusters can impact the neutron interrogation due to an increase in self-shielding effect. This work presents a matrix effect correction method based on the use of internal flux monitors (sensitive to the neutron absorption ratio) and the transmission signal (sensitive to the slow-down ratio). It relies on a numerical model of the whole measurement cell developed with the Monte-Carlo N-Particle transport (MCNP) code. The calibration coefficient of 72 different matrices, representative of the waste produced at La Hague, were simulated and a statistical model using a multilinear regression was then established. This simulated-based approach provides a more robust and comprehensive estimation of the residual fissile mass without impacting accuracy thanks to the flux monitors and the transmission signals.

A novel method for optimizing energy absorption of tensegrities with multi- self-stress modes

To explore the factors that affect the energy absorption performance of tensegrities with multi-self-stress modes, the Beetle Antennae Genetic Algorithm (BAGA) is carried out in developing reasonable energy absorption optimization strategies. In the first stage, based on the form-finding theory, the initial self-stress (including prestress level and distribution) that meets unilateral property of components was found. Then, the maximum energy that the structure can absorb under vertical loads is taken as the objective function, and constraint conditions regarding cable relaxation, elastic failure, global volume, strut buckling and component collision are considered in obtaining the satisfactory optimal initial self-stress. Finally, three tensegrities with multi-self-stress modes are taken as illustrative examples, the impact of optimal prestress level and the corresponding distribution on the structural energy absorption performance are explored. The results indicate that, for a 18-rod tensegrity and two types of assembled complicated tensegrity, the energy absorption can be respectively increased by about 156.88 %, 50.75 % and 131.09 % with simultaneously optimizing the pre-stress level and its distribution, verifying the effectiveness of the proposed algorithm. Additionally, for the assembled complicated tensegrity constructed using two different assembling ways (corresponding to different assembled prestress distributions), the optimal structural energy absorption ratio can be as high as 1.88 times.

Bimetallic CuFe Prussian Blue Analogue Nanocubes as a Colorimetric Probe for the Quantification of Glutathione

Label-free bimetallic CuFe Prussian blue analogue nanocubes (CuFe PBA NCs) were directly employed as colorimetric probes for the visual determination of glutathione (GSH). CuFe PBA NCs produce an absorption peak at 400 nm. In the presence of GSH, the CuFe PBA NCs were transformed into larger hollow nanospheres based on the acid-initiated Kirkendall effect, leading to the appearance of a new peak at 520 nm and a solution color change from yellow to red. Thus, the GSH-induced color changes allowed the establishment of a double-signal colorimetric assay for GSH using the ratio of absorbance at 520 and 400 nm (Δ(A520/A400)). Facile determination of GSH from 0.1 to 8 μM with satisfactory specificity was developed, providing a detection limit as low as 0.08 μM. Additionally, GSH concentrations exceeding 3 μM can be directly identified by the naked eye. The colorimetric assay for GSH has also been demonstrated to have application for serum analysis. Compared with conventional single-signal colorimetric determination, the ratiometric probe was demonstrated to provide good selectivity and high sensitivity.

Numerical study on the effect of temperature rise of humeral bone nails in magnetic resonance imaging based on the finite-element method.

Humeral fracture is a common long bone fracture in orthopedic clinical diagnosis and treatment. To investigate the local temperature increase owing to changes in the specific absorption ratio (SAR) of the human body caused by humeral bone nails during magnetic resonance imaging (MRI). A refined geometric model of the upper body was constructed via data segmentation and post-processing using the digital human image dataset. Finally, the geometric model was imported into COMSOL, a 3-T magnetic resonance coil was built, and the operating frequency (128 MHz) was set to analyze the SAR of the bone-nail pair and temperature changes. The analysis of the changes after bone-nail implantation under different tissue conditions revealed that the SAR and temperature after implantation and fixation were three times higher than those before, and the areas with abrupt changes in SAR and temperature were primarily concentrated in the bone-nail area. In MRI, metal implants can cause local elevation of the SAR near the implant in the human body, resulting in a temperature increase around the implant. Consequently, long-term scanning can damage the human body.

Utilization of absorbance subtraction and ratio difference green spectrophotometric methods for the quantification of alfuzosin hydrochloride and tadalafil in their binary mixture

Alfuzosin hydrochloride and tadalafil fixed-dose combination tablets were recently formulated for the treatment of individuals with lower urinary tract symptoms caused by benign prostatic hyperplasia. Herein, the first spectrophotometric methods for quantitative analysis of alfuzosin hydrochloride and tadalafil in their binary mixture were established. The spectral overlapping of alfuzosin hydrochloride and tadalafil made direct simultaneous analysis unfeasible. Therefore, two mathematical methods were used to solve these overlapping spectra: absorbance subtraction and ratio difference. The absorbance subtraction method manipulates the zero absorption spectra of the studied drugs at the isoabsorptive point (272 nm) and uses the absorbance factor of pure ALF to calculate the absorbance of the studied drugs in the mixture at the isoabsorptive point. The ratio spectra method, on the other hand, manipulates the ratio spectra of the studied drugs, which are obtained by dividing each drug’s zero absorption spectra by a divisor spectrum from the second drug. The ratio amplitude difference between 251 nm and 211 nm was directly proportional to alfuzosin hydrochloride, whereas between 292 nm and 222 nm it was directly proportional to tadalafil. The methods used were verified in accordance with the recommendations of the ICH and demonstrated adequate linear regression in working ranges of 1–15 µg/mL for alfuzosin hydrochloride and 3–40 µg/mL for tadalafil. The methods were accurate, precise, and selectively employed to quantify alfuzosin hydrochloride and tadalafil in their combined tablets.

Degradation Rate/Vulnerability Potential and Fertility Status of Luvisols in the Mandara Mountains (Far-North Cameroon).

Soil degradation emerges as one of the major problems in the locality of Sir in the Mandara Mountains, Far-North Cameroon. Inappropriate agricultural techniques resulting in land use change affect soil functions and seriously harm forest ecosystems. This study was conducted to analyse the current character of soils and access their degradation and their level of fertility. Twenty soil samples were taken at 15 cm depth. This includes ten in the plot under forest reserve and ten others in the plot under cultivation. Cultivation is responsible for the increase in bulk density (BD) (1.59 to 2.23 g/cm3), Mg (4.76 to 6.40 cmol·kg-1), Ca (10.44 to 11.26 cmol·kg-1), P (7.93 to 9.93 g/kg), and Mg/K (2.28 to 5.84) and decrease in CEC (38 0.15 to 31.46 cmol·kg-1), OM (2.76 to 1.08%), OC (1.66 to 0.62%), total nitrogen (0.08 to 0.05%), K (4.59 to 1.15 cmol·kg-1), Na (1.32 to 0.91 cmol·kg-1), C/N (25.69 to 13.86), and Ca/Mg (2.32 to 1.89). This variability in physicochemical properties reflects progressive soil degradation. Cultivated soils are subject to severe degradation or potential vulnerability (SDR/Vp = 4/2) due to texture, organic carbon, soil aggregate stability, sealing index, and total nitrogen. On the other hand, soils under forest reserve are subject to severe degradation or vulnerability due to the total nitrogen and sodium absorption ratio. The soils of the study area are subject to severe and extreme potential degradation or vulnerability due to BD, respectively, under forest reserve and cultivation. Two classes of fertility were identified: class II (plots under forest reserve) having a good level of fertility, characterized by good physical properties and severe limitations in nitrogen and phosphorus and class IV (cultivated plots) with a low level of fertility due to severe limitations in organic matter, phosphorus, and poor physical characteristics. The best indicator of the good quality of the luvisols of Sir is the pH, while the bulk density is an indicator of severe to very extreme degradation or high to very high vulnerability. The application of organic and mineral amendments is essential for raising the organic matter and nitrogen and phosphorus contents in these soils.

A comprehensive review of experimental studies on shear behavior of bolted rock joints with varying rock joint and bolt parameters and normal stress

AbstractThe shear characteristics of bolted rock joints are crucial for the stability of tunneling and mining, particularly in deep underground engineering, where rock bolt materials are exposed to high stress, water pressure, and engineering disturbance. However, due to the complex interaction between bolted rock joints and various geological contexts, many challenges and unsolved problems arise. Therefore, more investigation is needed to understand the shear performance of bolted joints in the field of deep underground engineering. This study presents a comprehensive review of research findings on the responses of bolted joints subjected to shearing under different conditions. As is revealed, the average shear strength of bolted rock joints increases linearly with the normal stress and increases with the compressive strength of rock until it reaches a stable value. The joint roughness coefficient (JRC) affects the contact area, friction force, shear strength, bending angle, and axial force of bolted rock joints. A mathematical function is proposed to model the relationship between JRC, normal load, and shear strength. The normal stress level also influences the deformation model, load‐carrying capacity, and energy absorption ratio of bolts within bolted rock joints, and can be effectively characterized by a two‐phase exponential equation. Additionally, the angle of the bolts affects the ratio of tensile and shear strength of the bolts, as well as the mechanical behavior of both bolted rock joints and surrounding rock, which favors smaller angles. This comprehensive review of experimental data on the shear behavior of bolted rock joints offers valuable theoretical insights for the development of advanced shear devices and further pertinent investigations.

A modified CTAB method for the extraction of high-quality RNA from mono-and dicotyledonous plants rich in secondary metabolites

BackgroundHigh-quality RNA extraction from woody plants is difficult because of the presence of polysaccharides and polyphenolics that bind or co-precipitate with the RNA. The CTAB (cetyl trimethylammonium bromide) based method is widely used for the isolation of nucleic acids from polysaccharide-rich plants. Despite the widespread use of the CTAB method, it is necessary to adapt it to particular plant species, tissues and organs. Here we described a simple and generalized method for RNA isolation from mature leaf tissues of several economically important woody (17) and herbaceous plants (2) rich in secondary metabolites. High yields were achieved from small amount (up to 50 mg) of plant material. Two main modifications were applied to the basic protocol: an increase in β-mercaptoethanol concentration (to 10%v/v) and the use of an effective DNase treatment. As opposed to similar studies, we tried to describe a more detailed protocol for isolating RNA, including the exact quantity and concentration of the reagents were used.ResultsOur modified CTAB method is proved to be efficient in extracting the total RNA from a broad range of woody and herbaceous species. The RNA yield was ranged from 2.37 to 91.33 µg/µl. The A260:A280 and A260:A230 absorbance ratios were measured from 1.77 to 2.13 and from 1.81 to 2.22. The RIN value (RNA Integrity Number) of the samples fell between 7.1 and 8.1, which indicated that a small degree of RNA degradation occurred during extraction. The presence of a single peak in the melt curve analyses and low standard errors of the Ct values of replicated measurements indicated the specificity of the primers to bind to the cDNA.ConclusionsOur RNA isolation method, with fine-tuned and detailed instructions, can produce high quality RNA from a small amount of starting plant material that is suitable for use in downstream transcriptional analyses. The use of an increased concentration of the reducing agent β-mercaptoethanol in the extraction buffer, as well as the application of DNaseI-treatment resulted in a method suitable for a wide range of plants without the need of further optimalization, especially in Rhus typhina (Staghorn sumac), for which molecular-genetic studies have not yet been sufficiently explored.