Chemical Components Research Articles

Short-term exposures to PM2.5, PM2.5 chemical components, and antenatal depression: Exploring the mediating roles of gut microbiota and fecal short-chain fatty acids

BACKGROUNDPM2.5 and its chemical components increase health risks and are associated with depression and gut microbiota. However, there is still limited evidence on whether gut microbiota and short-chain fatty acids (SCFAs) mediate the association between PM2.5, PM2.5 chemical components, and antenatal depression. The purpose of this study was to investigate the mediating role of maternal gut microbiota in correlations between short-term exposure to PM2.5, short-term exposure to PM2.5 chemical components, and antenatal depression. METHODSDemographic information and stool samples were collected from 75 pregnant women in their third trimester. Their exposure to PM2.5 and PM2.5 chemical components was measured. Participants were divided into the non-antenatal depression group or the antenatal depression group according to the cut-off of 10 points on the Edinburgh Postnatal Depression Scale (EPDS). The gut microbiota were analyzed using the 16S rRNA-V3/V4 gene sequence, and the concentration of PM2.5 and its chemical components was calculated using the Tracking Air Pollution in China (TAP) database. Gas chromatography–mass spectrometry was used to analyze SCFAs in stool samples. In order to assess the mediating effects of gut microbiota and SCFAs, mediation models were utilized. RESULTSThere were significant differences between gut microbial composition and SCFAs concentrations between the non-antenatal depression group and the antenatal depression group. PM2.5 and its chemical components were positively associated with EPDS scores and negatively associated with genera Enterococcus and Enterobacter. Genera Candidatus_Soleaferrea (β = -7.21, 95%CI -11.00 to -3.43, q = 0.01) and Enterococcus (β = -2.37, 95%CI -3.87 to -0.87, q = 0.02) were negatively associated with EPDS scores, indicating their potential protective effects against antenatal depression. There was no significant association between SCFAs and EPDS scores. The mediating role of Enterococcus between different lagged periods of PM2.5, PM2.5 chemical component exposure, and antenatal depression was revealed. For instance, Enterococcus explained 29.23% (95%CI 2.16% to 87.13%, p = 0.04) of associations between PM2.5 exposure level at the day of sampling (lag 0) and EPDS scores. CONCLUSIONOur study highlights that Enterococcus may mediate the associations between PM2.5, PM2.5 chemical components, and antenatal depression. The mediating mechanism through which the gut microbiota influences PM2.5-induced depression in pregnant women still needs to be further studied.

Surface accuracy prediction method for mesh reflector antenna considering uncertainty factors in manufacturing process

The cable-net structure of mesh reflector antenna meets the requirement of surface accuracy by optimizing the shape and tension. However, in the process of manufacturing and assembly, there are inevitable random errors and structure gravity, which lead to the displacement of the nodes in surface, the surface accuracy of the antenna decreases after fabrication eventually. It is challenging to analyze the uncertainty factors and the effects on the surface accuracy. Therefore, this paper analyzes the uncertainty factors of the antenna during fabrication and proposes a method to predict the surface accuracy of the antenna after manufacturing and assembly. Firstly, based on the equilibrium equation of the cable-net structure, the mechanism of node displacement induced by uncertainty factors leading to the reduction of surface accuracy is analyzed. Secondly, based on the structure characteristics and manufacturing conditions of the antenna, the uncertainty factors including cable-net manufacturing and assembly errors, cable-truss assembly errors and gravity are analyzed qualitatively and quantitatively, the distributions of the uncertainty factors are given. Thirdly, based on Monte Carlo method, the mean and interval of the surface accuracy of different dimension parameters are predicted, the empirical prediction formulas of the surface accuracy mean and interval are fitted. Finally, the accuracy and effectiveness of the proposed formulas are verified by several numerical simulations and surface accuracy measurement experiments. The prediction method can effectively guide the design and craft of large-aperture mesh reflector antenna.

Random Vibration Fatigue Life Prediction of Nano-Silver Solder Joint

Nano-silver is a very potential electronic interconnection material. It’s excellent physical and chemical properties, high thermal conductivity and good electrical conductivity make it very suitable for high power electronic devices. In practical engineering, 20% of the failure of electronic products is caused by vibration load, so it is necessary to study the vibration reliability of interconnected materials. In this paper, the modal and random vibration finite element analysis of nano-silver solder joints were analyzed with workbench software. Predicting random vibration fatigue life of nano-silver solder joint by Coffin-Manson high cycle fatigue empirical formula, Miner’s linear cumulative damage theory and Steinberg model. The random vibration fatigue life of the nanosilver solder joint is 8342 h. It is found that the vibration reliability of nano-silver is inferior to Sn3.0Ag0.5Cu and Sn63Pb37 and the diameter of solder joints and PCB thickness are proportional to the vibration fatigue life, and the PCB thickness has a greater effect on the vibration life than the solder joint diameter. Solder joint height and pad thickness are inversely proportional to vibration fatigue life, and pad thickness has little effect on vibration fatigue life.

Time-varying compressive properties and constitutive model of EPDM rubber materials for tunnel gasketed joint

The stress relaxation of ethylene propylene diene monomer (EPDM) rubber material in a compressed state significantly increases the risk of water leakage at tunnel precast segmental joints. Additionally, EPDM rubber gaskets typically experience a complex precompression strain state, further complicating the prediction of long-term stress relaxation. Therefore, it is imperative to propose a novel constitutive model that realistically reflects the stress relaxation of rubber with arbitrary precompression strain, providing a reference for the long-term waterproof design of shield tunnels. In this study, the time-varying properties of EPDM rubber at material level were studied in detail. At first, a comprehensive set of accelerated aging tests were conducted on EPDM rubber samples with varying precompression strains. The hardening effect of rubber without precompression and the stress relaxation effect of rubber with precompression were explored. The time-varying law and mechanism governing rubber properties under these two effects were analyzed. Subsequently, a conversion relationship between the EPDM rubber test conditions and the actual service time was established. The predicted hardening coefficient for uncompressed EPDM after 100 years is 1.468, whereas the relaxation coefficient for compressed EPDM is 0.359. Comparative analysis revealed that the compression set index do not consider the beneficial effects of hardening, resulting in a 54.1% overestimation of the design water pressure. Finally, the analytical study on the constitutive model of EPDM rubber material was carried out. The error in compression curve for unaged sample obtained from empirical formulas exceeded three times that of the analytical model, underscoring the need to study time-varying constitutive models. An interpolation method was employed to extend the test curve, leading to the development of a new constitutive model that represents the stress relaxation characteristics of EPDM materials under arbitrary precompression strain states. By combining the proposed constitutive model with the timetemperature conversion relationship, the time-varying expressions of the constitutive parameters for relaxation and hardening effects during the service life were derived. In comparison with existing models, the proposed model demonstrates wider applicability, effectively captures the time-varying characteristics of EPDM materials under arbitrary precompression strains, offering an efficient approach for studying the long-term stress relaxation prediction of rubber gaskets in shield tunnels under complex precompression strain states.

Sheet-coating mitigation for membrane penetration in undrained triaxial tests and evaluation of comprehensive liquefaction resistance of crushed gravel

In undrained cyclic triaxial tests on crushed gravel, it is difficult to maintain undrained conditions because of the penetration of the rubber membrane (MP: membrane penetration) into the rough surface of the test specimens. A method has been developed in the present research to physically mitigate the MP-effect wherein the rough surface of each specimen is coated and smoothed by a prefabricated fines-soil sheet. This mitigation measure has been found very effective in minimizing the CR (compliance ratio for an undrained system) to achieve more strict undrained conditions. It has been further clarified that this method prevents not only the overestimation of the strength of loose specimens, as has already been recognized, but also the underestimation of the strength of dense specimens with highly positive dilatancy. The undrained cyclic strength of dense crushed gravel, comprised of various grain sizes and gradations, has been summarized in a series of undrained cyclic triaxial tests by employing the MP-mitigation method to find that, in place of the relative density governing the liquefaction resistance of loose soils, the void ratio or absolute density is a key parameter for uniquely estimating the strength with a simple empirical formula.

Tinosporae radix: A Review of Traditional Use, Botany, Phytochemistry, Bioactivity, and Quality Marker.

Tinosporae radix is the root tuber of Tinospora capillipes Gagnep of the Menispermaceae family. It has the effects of clearing away heat and toxins, benefiting the throat, relieving pain, and treating sore throat, carbuncle and boils, and other diseases in clinical practice. The related references about T. radix in this review were collected by online databases, including PubMed, Elsevier, Web of Science, Willy, SciFinder, SpringLink, Google Scholar, Baidu Scholar, ACS publications, Scopus, and CNKI. The other information about T. radix was acquired from ancient books and classical works. T. radix is an important medicinal plant with a variety of traditional uses according to the theory of Chinese medicine. Previous studies revealed that T. radix contained a variety of chemical components, including diterpenoids, alkaloids, steroids, cinnamic acid derivatives, and other compounds. Many pharmacological researches have exhibited that T. radix possesses various biological activities, including anti-cancer, hypoglycemic, anti-inflammatory, anti-bacterial, anti-ulcer, and anti-oxidant activities. Furthermore, the quality markers of T. radix were summarized and analyzed in this paper. The traditional use, botany, phytochemistry, bioactivity, and quality markers of T. radix were reviewed in this paper. It will not only provide an important clue for further studying T. radix, but also supply an important theoretical basis and a valuable reference for in-depth research and exploitations of this plant in the future.

A preliminary study on calcifying nanoparticles in dental plaque: Isolation, characterization, and potential mineralization mechanism.

Calcifying nanoparticles (CNPs), referred to as nanobacteria (NB), are recognized to be associated with ectopic calcification. This study aims to isolate and culture CNPs from the dental plaque of patients with periodontal disease and investigate their possible role in unravelling the aetiology of periodontal disease. Supragingival and subgingival plaques were sampled from 30 periodontitis patients for CNPs isolation and culture. Alkaline phosphatase (ALP) content changes were tracked over time. Positive samples underwent thorough morphological identification via hematoxylin and eosin (HE) staining, Alizarin red S (ARS), and transmission electron microscopy (TEM). The chemical composition of CNPs analysis involved calcium (Ca) and phosphorus (P) content determination, Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The subgingival plaque dental group exhibited a higher CNPs isolation rate at 36.67% (11/30) compared to the supragingival dental plaque group at 66.67% (20/30). ALP activity varied among the positive, negative and control groups. Morphological observation characterized the CNPs as round, oval, and ellipsoid particles with Ca deposits. Chemical analysis revealed the Ca/P ratio was 0.6753. Hydroxyl, methyl, carbonate, phosphate, hydrogen phosphate, and dihydrogen phosphate were detected by FTIR; the main chemical components detected by XRD were hydroxyapatite and tricalcium phosphate. CNPs were found in periodontitis-related dental plaque and exhibited the potential to develop calcified structures resembling dental calculus. However, the potential involvement of ALP in CNPs formation requires deeper exploration, as does the precise nature of its role and the interrelation with periodontitis demand a further comprehensive investigation.

Expanded therapeutic applications of Holarrhena antidysenterica: A review.

The use of medicinal plants as a rich resource of therapeutic agents in the treatment and prevention of diseases & ailments has been recognized for millennia and is highly regarded worldwide. Holarrhena antidysenterica (H. antidysenterica), also called kurchi, or kutaj, has been utilized since the dawn of time, Apocynaceae member, also known as H. pubescens, is praised for the medicinal uses of its stem bark, leaves, and seeds in Ayurveda. The study concentrated on aggregate information regarding H. antidysenterica's therapeutic effects. The purpose of this study was to determine the antidiabetic activity of an extract from H. antidysenterica seeds in diabetic rats induced by streptozotocin. Regardless of its broad variety of biological and possible therapeutic uses, there has been increasing concern regarding the use of H. antidysenterica. Various phytochemicals have been extracted from H. antidysenterica in recent years and have demonstrated typical pharmacological properties, including antibacterial, anti-diarrhoeal, anti-diabetic, anti-oxidant, anti-urolithic, and anti-inflammatory activity.. This review paper investigated the in-depth description and pharmacological properties of the plant, which produced significant findings on the chemical components present and also verified the traditionally claimed properties associated with the plant.

Evaluation of Flavonoid-rich Fraction of Portulaca Grandiflora Aerial Part Extract in Atherogenic Diet-induced Atherosclerosis.

Portulaca grandiflora is a tiny, upright herb that contains a variety of chemical components, including alkaloids, glycosides, mucilage, proteins, tannins, flavonoids, saponins, polysaccharides, and triterpenoids possessing properties that may help with atherosclerosis. The reported pharmacological properties of Portulaca grandiflora are antioxidant, antidiabetic, antiasthmatic, antibacterial, antiulcer and anti-inflammatory properties. The yield of methanol extract is higher than that of ethanol and acetone, and its phytoconstituents, like flavonoids and polyphenols, and has potent antioxidant properties. In order to determine the effectiveness ofPortulaca grandiflora methanol extract fraction against high-fat diet (HFD)-induced hyperlipidemia, hemodynamic change, antioxidant levels, and vascular dysfunction in rats, a study was carried out on a flavonoid-rich methanol extract fraction of the aerial part of Portulaca grandiflora Hook. This method involves a study of 30 days involving male Wistar rats (240-250 g) (n=5) that were fed with an Ath diet. Study groups were divided into (i) The Control Group, (ii) the Diseases Control Group, (iii) Disease + Standard drug (Atorvastatin 20mg/kg, orally, (iv) Disease + Test Extract dose 1 (Portulaca grandiflora 200mg/kg orally), and (v) Disease + Test Extract dose 2 (Portulaca grandiflora 400mg/kg orally). Both the test drug Portulaca grandiflora and the standard drug Atorvastatin were given orally for 30 days. At the end of the study, blood samples were taken to measure the serum lipid profile, alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, and levels of oxidative tissue stress. Hemodynamic parameters and aortic staining were performed. Portulaca grandiflora treatment improved the lipid profile and considerably reduced oxidative stress levels. Aortic staining examination revealed a marked reduction in atherosclerotic lesions. These results revealed that Portulaca grandiflora is an effective treatment approach in preventing atherosclerotic lesion progression, which is attributed to its protection against oxidative stress and various enzymatic activities in the Atherogenic model.

A new economical route for the grapefruit peel essential oil: Nanoemulsion form and insecticidal activity

The essential oil (EO) extraction is one of the ways to utilize of grapefruit (Citrus paradisi L.) peel waste. However, the low stability and penetration problems of EO limit their use. These limitations can be overcome by nanoemulsions. Therefore, this study aimed to form and characterize of the grapefruit peel essential oil nanoemulsion (EON) and investigate its insecticidal properties against Sitophilus granarius (Linnaeus, 1875) and Tribolium castaneum (Herbst, 1797) for an alternative bio-economic way. The grapefruit peel EON (4:3:3:90 w/w, EO:Tween 80:Ethanol:water) was formed by using the grapefruit peel EO with major chemical components such as d-limonene (85.70 %), myrcene (3.57 %), α-pinene (1.17 %). The grapefruit peel EON was characterized by TEM (50–120 nm), Zeta sizer (the mean droplet particle size: 109.3 nm, ζ-potential value:-20.6 mV, polydispersity index:0.265) and FT-IR analysis. 500 ppm of the grapefruit peel EON caused 50 % and 20 % mortality in S. granarius and T. castaneum after 7 days, respectively. 1000 ppm of the grapefruit peel EON caused 85 % and 50 % mortality in S. granarius and T. castaneum after 7 days, respectively. Based on the findings, the grapefruit peel EON may be considered having the potential to integrate management strategies for these pests and open a new bio-economic way.

A Review on Pencil Cactus (Euphorbia tirucalli)

Abstract: In this review, we looked at medicinal plants that are used to treat various illnesses. These are a few of the naturally occurring herbal plants that have a wide range of chemical components that are used to cure different diseases. Because of their high activity and lack of side effects, herbal plants play a significant role in treatment. The taxonomy distribution, colloquial names, phytoconstituents, morphology, pharmacological activity, medicinal applications, conclusion, and references of the plants were all examined in this review.

Chemical components and antioxidant potential of essential oil of Rhanterium epapposum growing in sandy habitat in Saudi Arabia: In silico study on cytochrome P450 1A1 and xanthine oxidase

Rhanterium epapposum Oliv. (Family: Asteraceae) is a common plant in Saudi Arabia, possessing a variety of traditional uses. The current targets were studying the comparative chemical profile and antioxidant of the essential oil (EO) of R. epapposum collected from a sandy habitat at Qareenah, Riyadh, Saudi Arabia. The EO profiling was constructed via gas chromatography-mass spectrometry (GC-MS) and GC-flame ionization detection (GC-FID). Forty-eight compounds were found, including monoterpenes (hydrocarbons 3.25% and oxygenated 48.64%), sesquiterpenes (hydrocarbons 12.64 % and oxygenated 32.38%), which are the backbone of the oil along with a minor of other non-terpenoid compounds (1.31%). Linalool (18.02%), α-eudesmol (11.98%), trans-sesquisabinene hydrate (11.63%), aromadendrene oxide-(1) (7.68%), nerol (6.88%), and α-terpineol (5.01%) were identified as the dominant components. The EO was evaluated for its antioxidant activity using in vitro DPPH, ABTS, and FRAP methods. The results demonstrated that R. epapposum EO possesses a dosage-dependent ability for antioxidant scavenging activity as per all three techniques. This EO exhibited IC50 values of 517.59, 350.24, and 713.72 μg/mL for the DPPH, ABTS, and FRAP, respectively, through the comparison with the ascorbic acid with respective values of 36.10, 26.12, and 44.58 μg/mL. The main compounds were subjected to docking analysis on cytochrome P450 1A1 and xanthine oxidase. All evaluated compounds exhibited good binding affinities especially α-eudesmol and linalool for both enzymes, respectively. The current research confirmed the potent free radical scavenging properties of R. epapposum EO. More research on the antioxidant content of this oil and/or its primary constituents in pure form on the two enzymes, cytochrome P450 1A1 and xanthine oxidase, is proposed to develop a better understanding of the oxidative action routes in vivo and in vitro.

REVIEW OF COMPREHENSIVE STUDY ON DIFFERENT ACTIVITIES OF PRIYANGU

The chemical components found in plants make them a vital and fundamental component of complementary and alternative medicine. Traditional medicine has made use of plants of the Aglaia genus, the species in the Meliaceae family. the genus Aglaia has more than one hundred. Juss. Aglaia elaeagnoidea In the Western Ghats and other dry regions of India, Benth trees grow in dense, damp woods. Priyangu and chokkala are two of the common names. Rural people use the bark and leaves of this tree, much like they do with other Aglaia species. The Aglaia elaeagnoidea plant's leaves and stem bark are used in Indian medicine, specifically Ayurvedic medicine, to treat a variety of conditions, including skin diseases, tumors, insect repellent, antibacterial, anti-inflammatory, wound-healing, and anti-cancer. Numerous studies have documented the existence of phytoconstituents in plant extracts, providing empirical evidence for the anti-inflammatory, analgesic, anti-tumor, and anti-hypertensive effects of plants. This review includes information on Aglaia elaeagnoidea phytochemistry and pharmacological properties.

RANSE simulations for unmanned sailboat performance prediction: Coupling aerodynamics and hydrodynamics in self-sailing

During the design phase of sailboats, naval architects typically employ hydrodynamic and aerodynamic models of the sailboat, utilizing a Velocity Prediction Program (VPP) to solve the equations of motion, thus determining the sailboat's speed and performance. Traditional methods for solving sailboat motion equations often employ simplified empirical formulas or costly experimental procedures, which yield less accurate results. This study presents the RANSE-based CFD software STAR-CCM + to comprehensively model the sailboat's hull-sail-rudder assembly. By implementing overset grid technology and the Volume of Fluid (VOF) model, the paper aims to couple the solution of aerodynamic and hydrodynamic forces under wind influence and introduces PID rudder control technology to maintain a balance of forces and convergence of motion state. This approach enables the prediction of the sailboat's speed and performance, such as yaw angle, heel, and rudder angle. Results demonstrate minimal variations in sailboat speed (<0.05 m/s) and heading (<0.1°) in upwind, downwind and reaching sailing conditions, underscoring the method's feasibility and advocating for further research into self-sailing performance.

Relaxation of Spring Festival Firework Regulations Leads to a Deterioration in Air Quality.

The relaxation of restrictions on Chinese Spring Festival (SF) firework displays in certain regions has raised concerns due to intensive emissions exacerbating air quality deterioration. To evaluate the impacts of fireworks on air quality, a comparative investigation was conducted in a city between 2022 (restricted fireworks) and 2023 SF (unrestricted), utilizing high time-resolution field observations of particle chemical components and air quality model simulations. We observed two severe PM2.5 pollution episodes primarily triggered by firework emissions and exacerbated by static meteorology (contributing approximately 30%) during 2023 SF, contrasting with its absence in 2022. During firework displays, freshly emitted particles containing more primary inorganics (such as chloride and metals like Al, Mg, and Ba), elemental carbon, and organic compounds (including polycyclic aromatic hydrocarbons) were predominant; subsequently, aged particles with more secondary components became prevalent and continued to worsen air quality. The primary emissions from fireworks constituted 54% of the observed high PM2.5 during the displays, contributing a peak hourly PM2.5 concentration of 188 μg/m3 and representing over 70% of the ambient PM2.5. This study underscores that caution should be exercised when igniting substantial fireworks under stable meteorological conditions, considering both the primary and potential secondary effects.

Study on the Mechanism of Action of the Traditional Chinese Medical Prescription Gushukang in Treating Osteoporosis Based on Network Pharmacology and Experimental Verification.

Gushukang (GSK), a traditional Chinese medical prescription, has made a great and extensive contribution to the treatment of different forms of osteoporosis, but polypharmacology studies of its mechanism of action are lacking. This study investigates the pharmacological mechanism of osteoporosis using network pharmacology and molecular docking. Experimental verification was carried out to confirm the efficacy of GSK on RANKLinduced osteoclast differentiation in RAW264.7 cells to verify the network pharmacology studies. The effective chemical components and corresponding targets of osteoporosis with oral bioavailability of more than 30% and drug-like properties greater than 0.18 were searched in the TCMSP and TCM-ID databases. DrugBank, GeneCards, OMIM, TTD, and other databases were examined for targets related to osteoporosis. Using Cytoscape software, a network of possible TCM-active ingredient-osteoporosis targets was created. STRING software was used to create the networks of protein-protein interactions. The DAVID program was carried out to conduct GO and KEGG pathway enrichment analyses of the targets. Molecular docking and pattern of action analysis were carried out using software like AutoDock Vina and Discovery Studio Visualizer. The growth media for RAW264.7 cells contained varying doses of GSK serum and 50 ng/mL RANKL. The activity of TRAP was altered. Additionally, genes related to osteoclasts were examined using an RT-PCR assay. Network pharmacological analysis revealed that the primary efficacy targets of osteoporosis were PTGS2, PTGS1, HSP90AA1, NCOA2, ADRB2, ESR1, NCOA1, and AR. The pharmacological targets of osteoporosis may be mediated by substances including quercetin, kaempferol, luteolin, naringenin, icariin, anthocyanin, tanshinone IIA, and cryptotanshinone. GSK markedly inhibited RANKL-induced TRAP activity. qRT-PCR results revealed decreased expression of the PTGS2 and ADRB2 genes upon GSK treatment. The findings of network pharmacology, molecular docking, as well as experimental verification provide a new further study for elucidating the pharmacodynamic substance basis and polypharmacology mechanism of GSK in treating osteoporosis.

Comprehensive Multipath Variational Kinetics Study on Hydrogen Abstraction Reactions from Three Typical Dimethylcyclohexane Isomers by Hydroxyl Radicals: from the Electronic Structure to Model Applications.

Cycloalkanes serve as an important class of chemical components in both fossil and alternative transportation fuels and have attracted considerable attention from the combustion community. Hydrogen abstractions from cycloalkanes by hydroxyl radicals initiate the fuel decomposition process and trigger off the subsequent chain reactions and thus play an important role in both combustion and atmospheric chemistry. The target of this study is to fill the vacancy in kinetics data toward the H-abstraction reactions by hydroxyl radical from three typical dimethylcyclohexane isomers through first-principles and direct dynamics. The rate constants involving 18 elementary reactions in total were accurately determined by the multipath canonical variational transition state theory with the multidimensional small-curvature correction for tunneling (MP-CVT/SCT), over a broad temperature range of 200-2000 K. The significant roles of multistructural torsional anharmonicity and recrossing effects were stressed per abstraction site, while the quantum tunneling effect was found to be slight at temperatures of interest in combustion. The discrepancies observed among different reaction systems at a similar abstraction site highlight the fuel molecular effects on site-specific rate constants. The comparison results of total rate constants given by different dynamics approaches prove the importance of considering the torsional anharmonicity, recrossing, and tunneling effects, and the robust feature of the simplified MS-CVT/SCT. The calculated total constants for dimethylcyclohexane isomers by OH are consistent with those measured for methylcyclohexane and 1,4-dimethylcyclohexane at low temperatures. The branching ratio analysis confirms the predominant role of the tertiary abstraction at low-to-intermediate temperatures and its growing competition with distinct secondary abstractions as temperature increases. The calculated rate constants were eventually fitted into the analytical expressions and incorporated into the kinetic models to learn about the influences on modeling performance.

Biowaste Valorization of Palm Tree Phoenix dactylifera L. for Nanocellulose Production

The desire to reduce reliance on oil resources arises from the concerns about carbon footprint and nonrenewability. Conversely, the global presence of over 100 million palm trees poses a significant challenge due to the substantial amount of biowaste generated annually. Additionally, the use of nanocellulose (NC) as a cost-effective material is steadily gaining recognition for its growing adaptability over time. The main goal of this study is to biosynthesized NC from Iraqi date palm Phoenix dactylifera leaves waste with low-concentration acid-alkali treatment. The date palm leaves waste yields 20 g of NC from 100 g of leaves before acid hydrolysis treatment. The chemical components of biosynthesized NC were 47.90%, 26.78%, and 24.67% for α-cellulose, hemicellulose, and lignin, respectively. In order to study their properties, NC from raw date palm leaves was studied by microscopic techniques such as scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, and atomic force microscope (AFM). SEM results revealed rod-like structured NC as well as combined long-fine fibrous structures rather than compacted bundles with sizes ranging between 31 and 74 nm. With EDX, all spectra exhibit the peaks of carbon and oxygen as the main elements with 63.8% and 10.44%, respectively, in their compositions, which relate to the typical composition of cellulose. The 3D image of AFM NC with a tapping mode presented a highly uniform distribution of NC with a size of ∼15 nm. The statistical roughness analysis shows that the obtained roughness average is 7.20 nm with the root–mean-square roughness value of 21.56 nm, which corresponded relatively with the micrographs of SEM. The results of this study demonstrate the promise of using date palm waste as raw material to produce NC as green nanocomposite from biodegradable nanomaterials for water purification and sustained drug delivery for biomedical applications. In this regard and because of the insufficient reports about the extraction of NC from palm tree leaves waste, the objective of this study was designed to fabricate NC biologically from fibers sourced from the waste of Iraqi date palm P. dactylifera leaves that left in agricultural lands or burned, which can be an ecological and health problem as a bionanocomposites in the medical and industrial field and as alternative resources of wood materials.

STAGED, LAPAROSCOPIC HYBRID EPAULI REPAIR FOR LARGE PARASTOMAL HERNIA – CASE REPORT

Abstract Background Managing large parastomal hernias poses significant challenges due to their high recurrence rates and the elevated risk for peri- and post-operative complications. Method Case report of a successful repair of a large parastomal hernia using a staged minimally invasive, hybrid approach. Results The patient underwent uncomplicated laparoscopic total colectomy in 2016 for ulcerative colitis. Several years later, in 2020, the patient presented to our hospital with a large parastomal hernia with obesity as comorbidity. To address this complex hernia, the patient was referred to the obesity team and underwent laparoscopic gastric sleeve resection in autumn 2021. In 2022, the patient's BMI had decreased to below 30, prompting the decision to proceed with hernia surgery. In May 2022, we performed chemical component separation using 300 units of Botox. Four weeks later, laparoscopic hybrid Epauli repair was undertaken. The laparoscopic component involved reducing hernia contents, abdominal wall dissection with Transversus Abdominis Release (TAR), mesh placement, and closing the posterior layer. Open surgery was interspersed throughout the laparoscopic procedure and at its conclusion. This included temporary stoma closure and reduction, temporary stoma site closure, medial repositioning of the stoma through rectus, excess skin excision, and stoma re-suturing. The patient experienced an uncomplicated recovery. In January 2023, the patient underwent complete abdominoplasty. A one-year postoperative CT scan and clinical control demonstrated a satisfactory outcome. Conclusion For complex and large parastomal hernias, hybrid surgery, combining open and minimally invasive approaches, offers a valuable operative strategy for managing such large hernias.

Characterization of The Physical and Chemical Components of Mangrove Mud in The Cojimies River Estuary, Latitude 0 Experimental Station Located in The Mache River

Characterization of The Physical and Chemical Components of Mangrove Mud in The Cojimies River Estuary, Latitude 0 Experimental Station Located in The Mache River