274 research outputs found

    Chemical components of volatile oil from Cinnamomum jensenianum Hand Mazz leaf in Yongzhou, and its antibacterial and antioxidant properties

    Get PDF
    Purpose: To study the chemical components, and in vitro antibacterial and antioxidant properties of volatile oil extracted from Yongzhou Cinnamomum jensenianum Hand. Mazz leaves.Methods: The extraction process of volatile oil in the leaves of Yongzhou Cinnamomum jensenianum Hand. Mazz was optimized with respect to volatile oil yield, and the oil was subjected to gas chromatography-mass spectrometry (GC-MS) analysis. In vitro antimicrobial activities against bacteria and fungi were evaluated by the filter paper method, while in vitro antioxidant potential was determined by assaying its ability to scavenge DPPH radicals.Results: The optimized extraction conditions for volatile oil from the leaves of Yongzhou Cinnamomum jensenianum Hand. Mazz were 3.5 h extraction time, solid-liquid ratio of 1:10, and soaking time of 4 h, which resulted in volatile oil yield of 2.4 ± 0.19 %. A total of 37 components were isolated and identified, accounting for 99.19 % of the volatile oil. The in vitro antimicrobial activities against bacteria and fungi were significant, with minimum inhibitory concentration (MIC) between 10 and 20 uL. At a volatile oil concentration of 0.09 mg/mL, the DPPH scavenging ability of the oil was stronger than that of BHT.Conclusion: There is a high level of extractability of volatile oil from the leaves of Yongzhou Cinnamomum jensenianum Hand. Mazz. The main component is linalool (94.45 %), and it has good antibacterial and antioxidant properties.Keywords: Yongzhou Cinnamomum jensenianum Hand. Mazz, Volatile oil, Antibacterial, Antioxidan

    Synthesis and Characterization of Molecularly Imprinted Polymers for Phenoxyacetic Acids

    Get PDF
    2-methylphenoxyacetic acid (2-MPA), 2-methyl-4-chlorophenxyacetic acid (MCPA) and 4-chlorophenoxyacetic acid (4-CPA) were imprinted to investigate the cross-selectivities of molecularly imprinted polymers (MIPs). The result indicates that 2-MPA, which is similar in shape, size and functionality with phenoxyacetic herbicides, are suitable to be used as a suitable template to prepare the MIPs for retaining phenoxyacetic herbicides. To study the ion-pair interactions between template molecules and functional monomer 4-vinylpiridine (4-VP), computational molecular modeling was employed. The data indicate that the cross-selectivities of MIPs for phenoxyacetic acid herbicides depend on the binding energies of complexes

    Process optimization and insecticidal activity of alkaloids from the root bark of Catalpa ovata G. Don by response surface methodology

    Get PDF
    Purpose: To optimize the extraction of total alkaloids from the root bark of Catalpa ovata using response surface methodology, and to determine the insecticidal activity of the total alkaloids extracted. Methods: A combination of Box-Behnken design and response surface methodology  (RSM) was used to optimize the acid water extraction of total alkaloids from the root bark of Catalpa ovata, with extraction rate of total alkaloids as index and the single factor experiment as basis, and the extraction time, material: liquid ratio and pH as 3 factors. The insecticidal activity of total alkaloids was determined against the three instar armyworm Mythimna separata (Lepidoptera: Noctuidae) and  diamondback moth Plutella xylostella (Lepidoptera: Plutellidae).Results: The optimum extraction conditions for total alkaloids were: material: liquid ratio of 1:10; extraction time of 3 h, pH of 1.0, and simmering. Under these  conditions, total alkaloid extraction was 8.62 %, which was very close to the experimental value. The results were accurate and reliable, with reference value. The insecticidal activity of the total alkaloids indicate that when the concentration of the total alkaloids was 10 mg/L, the fatality rate of Plutella xyllostella and oriental armyworm was over 89 %, but the insecticidal activity of the total alkaloids was lower than that of avermectin which was employed as a reference.Conclusion: The alkaloids from the root bark of Catalpa ovata are potential botanical insecticides.Keywords: Catalpa ovata, Root bark, Total alkaloids, Response surface  methodology, Insecticidal activit

    Vibration Damping of Carbon Nanotube Assembly Materials

    Full text link
    Vibration reduction is of great importance in various engineering applications, and a material that exhibits good vibration damping along with high strength and modulus has become more and more vital. Owing to the superior mechanical property of carbon nanotube (CNT), new types of vibration damping material can be developed. This paper presents recent advancements, including our progresses, in the development of high-damping macroscopic CNT assembly materials, such as forests, gels, films, and fibers. In these assemblies, structural deformation of CNTs, zipping and unzipping at CNT connection nodes, strengthening and welding of the nodes, and sliding between CNTs or CNT bundles are playing important roles in determining the viscoelasticity, and elasticity as well. Towards the damping enhancement, strategies for micro-structure and interface design are also discussed

    Associations between smoke exposure and kidney stones: results from the NHANES (2007–2018) and Mendelian randomization analysis

    Get PDF
    PurposeIt is currently controversial whether smoke exposure is associated with the risk of kidney stones. Herein, publicly available databases were combined to explore relationships with the risk of nephrolithiasis in terms of smoking status and serum cotinine concentrations.Materials and methodsFirst, we conducted an observational study using data from 2007 to 2018, based on the National Health and Nutrition Examination Survey (NHANES) database. Univariate analysis, multivariate logistic regression, trend testing, restricted cubic spline (RCS), and multiple imputation (MI) were the main analytical methods of our study. Then, A Mendelian randomization (MR) analysis was performed to explore the causal relationship between serum cotinine and nephrolithiasis. Genetic instruments for serum cotinine and pooled data for kidney stones were derived from publicly available large-scale genome-wide association studies (GWAS). Inverse-variance weighting (IVW) was the primary method for our MR analysis.ResultsA total of 34,657 and 31,352 participants were included in the observational study based on smoking status and serum cotinine concentrations, respectively. Under full adjustment of covariates, current smokers had an increased risk of kidney stones compared to non-smokers [OR = 1.17 (1.04–1.31), P = 0.009, P for trend = 0.010]. Compared with serum cotinine of <0.05 ng/ml, serum cotinine levels of 0.05–2.99 ng/ml [OR = 1.15 (1.03–1.29), P = 0.013] and ≥3.00 ng/ml [OR = 1.22 (1.10–1.37), P < 0.001] were observed to have a higher risk of nephrolithiasis (P for trend < 0.001). In addition, a non-linear relationship between log2-transformed serum cotinine and the risk of nephrolithiasis was found (P for non-linearity = 0.028). Similar results were found when serum cotinine (log2 transformation) was used as a continuous variable [OR = 1.02 (1.01–1.03), P < 0.001] or complete data was used to analyze after MI. In the MR analysis, genetically predicted high serum cotinine was causally related to the high risk of nephrolithiasis [IVW: OR = 1.09 (1.00–1.19), P = 0.044].ConclusionCurrent smoking and high serum cotinine concentrations may be associated with an increased risk of kidney stones. Further research is needed to validate this relationship and explore its underlying mechanisms

    The treatment of tuberculosis in the upper thoracic spine using the small incision technique through the third rib

    Get PDF
    BackgroundThe complex anatomical structure of the upper thoracic spine makes it challenging to achieve surgical exposure, resulting in significant surgical risks and difficulties. Posterior surgery alone fails to adequately address and reconstruct upper thoracic lesions due to limited exposure. While the anterior approach offers advantages in fully exposing the anterior thoracic lesions, the surgical procedure itself is highly intricate. Although there exist various anterior approaches for the upper thoracic spine, the incidence of upper thoracic spine lesions is relatively low. Consequently, there are limited reports on the treatment and reconstruction of upper thoracic spine lesions using the third rib small incision approach in the context of upper thoracic tuberculosis.MethodsWe collected data from four patients with upper thoracic tuberculosis who were admitted to our department between July 2017 and November 2022. The treatment for upper thoracic tuberculosis involved utilizing the third rib small incision approach, which included two cases of thoracic 3–4 vertebral tuberculosis, one case of thoracic 4 vertebral tuberculosis, and one case of thoracic 5 vertebral tuberculosis. Among the patients, three were positioned in the left lateral position, while one was positioned in the right lateral position. Prior to admission, all four patients received a two-week course of oral medication, consisting of isoniazid, rifampicin, pyrazinamide, and ethambutol. After the surgical procedure, they continued receiving anti-tuberculosis treatment for a duration of 12 months.ResultsThe average duration of the surgical procedure was 150 min, with an average blood loss of 500 ml. One patient exhibited symptoms of brachial plexus injury, which gradually improved after careful observation. All patients experienced primary wound healing, and no complications such as pulmonary infection, respiratory failure, or other adverse events were observed. Additionally, one patient showed elevated transaminase levels, leading to a modification in the anti-tuberculosis drug regimen from quadruple therapy to triple therapy.ConclusionThe treatment of upper thoracic tuberculosis through the third rib small incision technique is a very good surgical approach, which has the advantages of safety and effectiveness

    Pengembangan Media Pembelajaran Fisika Berupa Buletin Dalam Bentuk Buku Saku Untuk Pembelajaran Fisikakelas VIII Materi Gaya Ditinjau Dari Minat Baca Siswa

    Full text link
    Tujuan dari penelitian ini untuk mengembangkan media pembelajaran berupa buletin dalam bentuk buku saku untuk pembelajaran Fisika kelas VIII pada materi Gaya ditinjau dari aspek materi, konstruk, dan bahasa serta minat baca siswa. Penelitian ini termasuk penelitian pengembangan yang menggunakan metode Research and Development (R&D). Penelitian ini menggunakan model pengembangan model prosedural yaitu model yang bersifat deskriptif yang menunjukkan tahapan-tahapan yang harus diikuti untuk menghasilkan produk berupa media pembelajaran.Jenis data yang diperoleh bersifat kualitatif dan kuantitatif yaitu angket dan wawancara. Teknik analisis data yang digunakan adalah analisis deskriptif kualitatif dan kuantitatif. Hasil penelitian menunjukkan bahwa media pembelajaran yang dikembangkan berupa buletin Fisika dalam bentuk buku saku memiliki kriteria sangat baik berdasarkan penilaian dari ahli materi, ahli bahasa Indonesia, dan ahli media memberikan rata-rata penilaian sebesar 86,56%. Media pembelajaran yang dikembangkan juga memiliki kriteria sangat baik bila ditinjau dari peningkatan minat baca siswa. Hal ini terbukti pada hasil angket minat baca awal dan akhir yang diberikan kepada siswa yang memberikan rata-rata peningkatan sebesar 11,13%. Selain itu juga dianalisis dengan menggunakan uji-t berpasangan terhadap data masing-masing kelompok uji coba untuk mengetahui signifikansi dari peningkatan minat baca siswa. Untuk uji coba perorangan diperoleh hasil perhitungan thitung = 6,957 > ttabel = 1,943 dan nilai Sig. = 0,001 < 0,05 yang berarti sangat signifikan. Untuk kelompok kecil didapatkan hasil perhitungan bahwa thitung = 7,848 > ttabel = 1,725 dan nilai Sig. = 0,000 < 0,05 yang berarti sangat signifikan. Untuk kelompok besar juga didapatkan hasil perhitungan bahwa thitung = 20,214 > ttabel = 1,725 dan nilai Sig. = 0,000 < 0,05 yang berarti sangat signifikan. Simpulan dari penelitian ini adalah media pembelajaran berupa buletin dalam bentuk buku saku memiliki kriteria sangat baik bila ditinjau dari aspek materi, konstruk, dan bahasa serta minat baca siswa

    Research progress in the removal of fluoride ions from mine water by adsorption method

    Get PDF
    Fluoride ions are widely distributed in surface rivers and groundwater bodies in China, especially in the mining areas along the Yellow River in the western Yellow River basin that there is a widespread problem of excessive fluoride in the mine water, which poses a potential threat to the local ecological environment and human health. The status quo of fluoride pollution in China is mostly at a low concentration pollution level, which leads to it difficult to remove efficiently through conventional water treatment technologies. The adsorption method is considered to be an effective way to remove low concentration fluoride ions because of its high adsorption efficiency and convenient operation. The research status of fluoride removal by commonly used adsorption materials such as carbon based, minerals, metals and metal organic frameworks (MOFs) was reviewed and summarized before summarizing the influence of different factors on the fluoride removal efficiency and adsorption mechanism of these adsorption materials. Then the application effect and operation cost of adsorption method in mine water treatment were emphatically analyzed, and the development direction of adsorption method in the treatment of low concentration (<10 mg/L) and high water content fluorine-containing mine water was prospected. In general, there are still some deficiencies in the study of fluoride removal by adsorption. In terms of adsorption mechanism, it should be further investigated from three aspects which includes the characteristics of adsorption materials, the occurrence form of fluoride ions and the interaction mechanism between adsorption materials and fluoride ions. For the engineering application of adsorption method, the demand of engineering application should be regarded as the guidance. Based on the above discussion, the research and development direction of removing fluoride ions from mine water by adsorption method is proposed, which is to focus on the development of low cost and high efficiency environment-friendly modified adsorbents based on natural/waste (ore) and carbon-based, aluminum-based or other new polymer adsorption materials under the principle of clarifying local policies and water quality and quantity. In addition, it is necessary not to improve the selective adsorption performance of the modified adsorbent for fluoride ions, but also to ensure the stability, economy and safety of the adsorbent in the whole life cycle of preparation, processing, production and recycling, thereby improving its competitiveness of the adsorption method in the actual application of fluoride containing wastewater and enhancing the application potential of the adsorption method
    corecore