RESUMO
Addictive, toxic, and carcinogenic constituents present in smokeless tobacco (SLT) products are responsible for the harmful effects associated with SLT use. There are limited data on levels of such constituents in SLT products used in Africa, a region with high prevalence of SLT use and the associated morbidity and mortality. Manufactured and custom-made SLT products were purchased from five African countries (South Africa, Uganda, Mauritania, Nigeria, and Zambia) using a standard approach for sample collection, labeling, and storage. Moisture content, pH, total and unprotonated (biologically available) nicotine, five tobacco-specific N-nitrosamines (TSNA), 10 polycyclic aromatic hydrocarbons (PAH), five metals and metalloids (As, Cd, Cr, Ni, and Pb), nitrate, and nitrite were analyzed. A total of 54 samples representing 15 varieties of manufactured SLT products and 13 varieties of custom-made SLT products were purchased and analyzed. In all samples, the total nicotine ranged from 1.6 to 20.5 mg/g product and unprotonated nicotine accounted for 5.3-99.6% of the total nicotine content. The sum of all five TSNA ranged from 1.6 to 100 µg/g product, with significant within-country variations observed across both the manufactured and custom-made varieties. Significant variations were also found for PAH, metals and metalloids, nitrates, and nitrites. This is the most comprehensive report on the chemical profiling of products from African countries. This is also the first study illustrating the variability of harmful constituents within the same types and brands of African SLT. Our findings emphasize the need for consumer education and interventions to reduce SLT use in Africa. The data reported here can be useful to regulators in considering measures to prevent the occurrence of high levels of known toxicants and carcinogens in manufactured products.
Assuntos
Metaloides , Nitrosaminas , Hidrocarbonetos Policíclicos Aromáticos , Produtos do Tabaco , Tabaco sem Fumaça , África , Carcinógenos/análise , Nicotina , Nitratos , NitritosRESUMO
Mild and efficient ruthenium-catalyzed hydroxy-arylation of the terminal double bond of N-substituted 3-methyleneisoindolin-1-ones is described. The reaction takes place with aryl diazonium salt as the arylating reagent and water as the hydroxyl source in visible light at ambient temperature. The strategy entails vicinal difunctionalization of alkene and enables construction of 3-benzyl-3-hydroxyisoindolin-1-one heterocyclic scaffolds in moderate to good yields. C-C and C-O bonds are formed in one pot without any external additive and oxidant through an in situ generation of a carbocation intermediate in green light.
RESUMO
The widespread COVID-19 pandemic, caused by novel coronavirus SARS-CoV-2, has emanated as one of the most life-threatening transmissible diseases. Currently, the repurposed drugs such as remdesivir, azithromycine, chloroquine, and hydroxychloroquine are being employed in the management of COVID-19 but their adverse effects are a matter of concern. In this regard, alternative treatment options i.e., traditional medicine, medicinal plants, and their phytochemicals, which exhibit significant therapeutic efficacy and show a low toxicity profile, are being explored. The current review aims at unraveling the promising medicinal plants, phytochemicals, and traditional medicines against SARS-CoV-2 to discover phytomedicines for the management of COVID-19 on the basis of their potent antiviral activities against coronaviruses, as demonstrated in various biochemical and computational chemical biology studies. The review consists of integrative and updated information on the potential traditional medicines against COVID-19 and will facilitate researchers to develop traditional medicines for the management of COVID-19.
RESUMO
This study tests the Post-Keynesian theory regarding bank stock returns and money supply endogeneity in the context of South Asian countries. This study uses panel data set from different sources over twenty-eight (28) years. The research uses different econometric techniques before switching to the generalized method of moments (GMM). The empirical results indicate a significant positive effect of net interest rate margins on bank loans in South Asian countries, whereas a positive relationship exists between foreign to local interest rates and the money supply. The findings depict that positive associations exist between inflation and money supply of banks, and between the money supply and bank stock returns. More specifically, the GMM results show that the money supply has positively affected the stock prices of banks suggesting strong policies for the stakeholders of these economies for the sake of economic growth and sustainable development.
RESUMO
INTRODUCTION: Comparison of platform switched (PS), sloping shoulder, and regular implants on stress reduction in various bone densities with finite element analysis. MATERIALS AND METHODS: A total of 12 three-dimensional finite element models were built to analyze the stress distribution model. Nobel Biocare 4.3 × 8 mm regular platform replace select implant with matching diameter easy abutment, Nobel Biocare 4.3 × 8 mm replace select implant PS with 3.5 mm diameter easy abutment, Bicon 4 × 8 mm implant with 4 mm diameter sloping shoulder abutments were created virtually in compact bone density using software. The 130 N axial force and a 90 N oblique loading force were applied to the abutment to analyze the stress. RESULTS: Under horizontal and vertical loading, the sloping shoulder implant had lesser stresses in cancellous bone when compared with PS and regular implants. Sloping shoulder implant showed more stress distribution at implant-abutment interface and at crestal area, whereas with regular implants, the stresses were distributed at cortical area. CONCLUSION: Sloping shoulder implant in subcrestal position is much favorable for bone growth, stress distribution, and preservation of remaining bone. CLINICAL SIGNIFICANCE: Use of sloping shoulder implant design distributes the stress apically and creates lesser stresses when compared with PS implants.
Assuntos
Densidade Óssea , Dente Suporte , Implantes Dentários , Análise do Estresse Dentário , Projeto do Implante Dentário-Pivô , Planejamento de Prótese Dentária , Análise de Elementos Finitos , Humanos , Estresse MecânicoRESUMO
Metabolic activation of the carcinogenic tobacco-specific N-nitrosamines leads to the formation of 4-hydroxy-1-(3-pyridyl)-1-butanone (HPB)-releasing DNA adducts. We recently developed a liquid chromatography (LC)-tandem mass spectrometry (MS/MS) method for the analysis of HPB-releasing DNA adducts in human oral cells. However, given the limited amounts of DNA that can be extracted from oral cells, higher sensitivity and selectivity are required for the reliable analysis of these adducts in future studies. We have developed a new sensitive LC-nanoelectrospray ionization-high-resolution MS/MS method for the analysis of HPB-releasing DNA adducts in oral cells. A new procedure was also developed for guanine analysis by LC-MS/MS. The detection limit of the developed assay is 5 amol, and the limit of quantitation is 0.35 fmol HPB on-column, starting with 50 pg of DNA. The method was tested by analyzing oral samples from 65 smokers, including 30 head and neck squamous cell carcinoma (HNSCC) patients and 35 cancer-free controls. In all smokers, the levels of HPB-releasing DNA adducts averaged 6.22 ± 16.18 pmol/mg DNA, with significant interindividual variation being consistent with previous reports. The median HPB-releasing DNA adduct level was 6.6 times greater for those with HNSCC than for smokers without HNSCC (p = 0.002). The developed highly sensitive and selective method is a valuable tool for future measurement of HPB-releasing DNA adducts in tobacco users, which can potentially provide critical insights for the identification of individuals at risk for cancer.
Assuntos
Butanonas/toxicidade , Cromatografia Líquida/métodos , Adutos de DNA/metabolismo , Boca/metabolismo , Nanotecnologia , Piridinas/toxicidade , Espectrometria de Massas em Tandem/métodos , Humanos , Limite de Detecção , Boca/citologiaRESUMO
In this work, we have addressed the problem of "acidity" of the water-pool of a reverse micelle (RM) through the well-known inversion of sucrose reaction as a tool of investigation. This reaction has been performed inside positively and negatively charged RM and the rates are compared with that in bulk water. We propose that the buffer-like action in a water-pool is much stronger than expected earlier. The rate of sucrose hydrolysis slowed down in the negatively charged AOT reverse micelle while it sped up for the positively charged CTAB reverse micelle. However, temperature-dependent measurements showed that the activation energy remained the same for all the cases. It has been concluded that a proton gradient exists inside the water-pool of the reverse micelle and it determines the buffer-like action of the water-pool that persists until about 2 N of HCl in AOT RM of w(0) = 10.5.
RESUMO
A very efficient route to the diastereoselective synthesis of polyhydroxy pyrrolidines, piperidines and azepanes from an aldehyde derivative of ribose is reported. Asymmetric α-amination of aldehydes using proline catalysed hydrazination is the key step in the synthesis. The method utilizes the stereocenters present in ribose and the extra carbon atoms present in the target molecules are incorporated using Wittig reactions. The incorporation of the amino group is carried out asymmetrically to account for additional stereocenters. This synthetic route to iminocyclitols has the potential to be extended for the synthesis of a large class of such compounds starting from other sugar derived aldehydes.
RESUMO
The environmental arylamine mutagens are implicated in the etiology of various sporadic human cancers. Arylamine-modified dG lesions were studied in two fully paired 11-mer duplexes with a -G*CN- sequence context, in which G* is a C8-substituted dG adduct derived from fluorinated analogs of 4-aminobiphenyl (FABP), 2-aminofluorene (FAF) or 2-acetylaminofluorene (FAAF), and N is either dA or dT. The FABP and FAF lesions exist in a simple mixture of 'stacked' (S) and 'B-type' (B) conformers, whereas the N-acetylated FAAF also samples a 'wedge' (W) conformer. FAAF is repaired three to four times more efficiently than FABP and FAF. A simple A- to -T polarity swap in the G*CA/G*CT transition produced a dramatic increase in syn-conformation and resulted in 2- to 3-fold lower nucleotide excision repair (NER) efficiencies in Escherichia coli. These results indicate that lesion-induced DNA bending/thermodynamic destabilization is an important DNA damage recognition factor, more so than the local S/B-conformational heterogeneity that was observed previously for FAF and FAAF in certain sequence contexts. This work represents a novel 3'-next flanking sequence effect as a unique NER factor for bulky arylamine lesions in E. coli.
Assuntos
2-Acetilaminofluoreno/química , Compostos de Aminobifenil/química , Adutos de DNA/química , Dano ao DNA , Reparo do DNA , Desoxiguanosina/análogos & derivados , Fluorenos/química , Sequência de Bases , Dicroísmo Circular , Adutos de DNA/metabolismo , Desoxiguanosina/química , Ensaio de Desvio de Mobilidade Eletroforética , Endodesoxirribonucleases/metabolismo , Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Modelos Moleculares , Simulação de Dinâmica Molecular , Ressonância Magnética Nuclear Biomolecular , Conformação de Ácido Nucleico , TermodinâmicaRESUMO
PURPOSE: To assess the correlation between self-perceived dental appearance and dental malocclusion among 18- to 20-year-old college students in Virajpet, Karnataka. MATERIALS AND METHODS: A stratified random sample consisting of 280 18- to 20-year-old college students in Virajpet were recruited for the study. A pretested Oral Aesthetic Subjective Impact Scale (OASIS) and Visual Analogue Scale (VAS) were used to assess the subjects' perception of dental aesthetics. Malocclusion was clinically assessed using the Dental Aesthetic Index (DAI). The data were tabulated and analysed using SPSS version 16. The Spearman rankorder correlation coefficient was employed to determine the correlation between self-perceived dental appearance and dental malocclusion. RESULTS: Of the 280 students, 41.8% were females and 58.2% were males. The mean OASIS score was 23.93 (±3.72), the VAS score was 69.61 (±15.78) and DAI 24.80 (±6.29). CONCLUSION: There was a negative correlation between perception of personal dental appearance and the DAI scores in this group.
Assuntos
Estética Dentária , Má Oclusão/psicologia , Autoimagem , Adolescente , Atitude Frente a Saúde , Estudos Transversais , Feminino , Humanos , Índice de Necessidade de Tratamento Ortodôntico , Índia , Masculino , Má Oclusão/classificação , População Rural , Sorriso , Escala Visual Analógica , Adulto JovemRESUMO
Adduct-induced DNA damage can affect transcription efficiency and DNA replication and repair. We previously investigated the effects of the 3'-next flanking base (G*CT vs G*CA; G*, FABP, N-(2'-deoxyguanosin-8-yl)-4'-fluoro-4-aminobiphenyl; FAF, N-(2'-deoxyguanosin-8-yl)-7-fluoro-2-aminofluorene) on the conformation of arylamine-DNA lesions in relation to E. coli nucleotide excision repair ( Jain , V. , Hilton , B. , Lin , B. , Patnaik , S. , Liang , F. , Darian , E. , Zou , Y. , Mackerell , A. D. , Jr. , and Cho , B. P. ( 2013 ) Nucleic Acids Res. , 41 , 869 - 880 ). Here, we report the differential effects of the same pair of sequences on DNA replication in vitro by the polymerases exofree Klenow fragment (Kf-exo(-)) and Dpo4. We obtained dynamic (19)F NMR spectra for two 19-mer modified templates during primer elongation: G*CA [d(5'-CTTACCATCG*CAACCATTC-3')] and G*CT [d(5'-CTTACCATCG*CTACCATTC-3')]. We found that lesion stacking is favored in the G*CT sequence compared to the G*CA counterpart. Surface plasmon resonance binding results showed consistently weaker affinities for the modified DNA with the binding strength in the order of FABP > FAF and G*CA > G*CT. Primer extension was stalled at (n) and near (n - 1 and n + 1) the lesion site, and the extent of blockage and the extension rates across the lesion were influenced by not only the DNA sequences but also the nature of the adduct's chemical structure (FAF vs FABP) and the polymerase employed (Kf-exo(-) vs Dpo4). Steady-state kinetics analysis with Kf-exo(-) revealed the most dramatic sequence and lesion effects at the lesion (n) and postinsertion (n + 1) sites, respectively. Taken together, these results provide insights into the important role of lesion-induced conformational heterogeneity in modulating translesion DNA synthesis.
Assuntos
Compostos de Aminobifenil/química , Reparo do DNA , Replicação do DNA , Fluorenos/química , Conformação de Ácido Nucleico , Sequência de Bases , Adutos de DNA , Dano ao DNA , DNA Polimerase I/metabolismo , Flúor/química , Cinética , Ressonância de Plasmônio de SuperfícieRESUMO
4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK, 1) is a potent tobacco-specific lung carcinogen believed to play a key role in the development of lung cancer in smokers. Metabolic activation of NNK to DNA damaging reactive intermediates proceeds via α-hydroxylation pathways. The end products of these pathways are excreted in the urine of smokers as 4-oxo-4-(3-pyridyl)butanoic acid (keto acid, 3) and 4-hydroxy-4-(3-pyridyl)butanoic acid (hydroxy acid, 4). The sum of these biomarkers (after NaBH4 treatment), referred to as total hydroxy acid, could potentially be used to measure the extent of NNK metabolic activation in smokers. However, the same metabolites are formed from nicotine; therefore, there is a need to distinguish the NNK- and nicotine-derived keto and hydroxy acid in smokers' urine. We previously developed a unique methodology based on the use of [pyridine-D4]NNK ([D4]1), which metabolizes to the correspondingly labeled biomarkers. In this study, we developed a sensitive and reproducible assay for the detection and quantitation of total [pyridine-D4]hydroxy acid ([D4]4) in human urine. A two-step derivatization approach was used to convert [D4]4 to [pyridine-D4]methyl 4-hexanoyl-4-(3-pyridyl)butanoate ([D4]6), and an LC-ESI-MS/MS method was developed for the analysis of this derivative with excellent sensitivity, accuracy, and precision. The robustness and reproducibility of the assay was further confirmed by its application for the analysis of urine samples from 87 smokers who smoked [D4]1-containing cigarettes for 1 week. The measured level averaged 130 fmol/mL urine. The developed assay can be used in future studies that may require evaluation of the relative efficiency of NNK metabolic activation in humans.
Assuntos
Hidroxibutiratos/urina , Nitrosaminas/metabolismo , Piridinas/urina , Biomarcadores/urina , Cromatografia Líquida de Alta Pressão , Humanos , Nitrosaminas/química , Fumar , Espectrometria de Massas por Ionização por ElectrosprayRESUMO
Nucleotide excision repair (NER) is a major repair pathway that recognizes and corrects various lesions in cellular DNA. We hypothesize that damage recognition is an initial step in NER that senses conformational anomalies in the DNA caused by lesions. We prepared three DNA duplexes containing the carcinogen adduct N-(2'-deoxyguanosin-8-yl)-7-fluoro-2-acetylaminofluorene (FAAF) at G(1), G(2) or G(3) of NarI sequence (5'-CCG(1)G(2)CG(3)CC-3'). Our (19)F-NMR/ICD results showed that FAAF at G(1) and G(3) prefer syn S- and W-conformers, whereas anti B-conformer was predominant for G(2). We found that the repair of FAAF occurs in a conformation-specific manner, i.e. the highly S/W-conformeric G(3) and -G(1) duplexes incised more efficiently than the B-type G(2) duplex (G(3)â¼G(1)> G(2)). The melting and thermodynamic data indicate that the S- and W-conformers produce greater DNA distortion and thermodynamic destabilization. The N-deacetylated N-(2'-deoxyguanosin-8-yl)-7-fluoro-2-aminofluorene (FAF) adducts in the same NarI sequence are repaired 2- to 3-fold less than FAAF: however, the incision efficiency was in order of G(2)â¼G(1)> G(3), a reverse trend of the FAAF case. We have envisioned the so-called N-acetyl factor as it could raise conformational barriers of FAAF versus FAF. The present results provide valuable conformational insight into the sequence-dependent UvrABC incisions of the bulky aminofluorene DNA adducts.
Assuntos
2-Acetilaminofluoreno/química , Adutos de DNA/química , Reparo do DNA , Desoxiguanosina/química , Fluorenos/química , Termodinâmica , Adenosina Trifosfatases/metabolismo , Sequência de Bases , Calorimetria , Dicroísmo Circular , Proteínas de Ligação a DNA/metabolismo , Desoxirribonucleases de Sítio Específico do Tipo II , Proteínas de Escherichia coli/metabolismo , Ressonância Magnética Nuclear Biomolecular , Conformação de Ácido Nucleico , Desnaturação de Ácido Nucleico , Espectrometria de Massas por Ionização por ElectrosprayRESUMO
Cluster DNA damage refers to two or more lesions in a single turn of the DNA helix. Such clustering may occur with bulky DNA lesions, which may be responsible for their sequence-dependent repair and mutational outcomes. Here we prepared three 16-mer cluster duplexes in which two fluoroacetylaminofluorene adducts (dG-FAAF) are separated by zero, one, and two nucleotides in the Escherichia coli NarI mutational hot spot (5'-CTCTCG1G2CG3CCATCAC-3'): 5'-CG1*G2*CG3CC-3', 5'-CG1G2*CG3*CC-3', and 5'-CG1*G2CG3*CC-3' (G* = dG-FAAF), respectively. We conducted spectroscopic, thermodynamic, and molecular dynamics studies of these di-FAAF duplexes, and the results were compared with those of the corresponding mono-FAAF adducts in the same NarI sequence [Jain, V., et al. (2012) Nucleic Acids Res. 40, 3939-3951]. Our nucleotide excision repair results showed the diadducts were more reparable than the corresponding monoadducts. Moreover, we observed dramatic flanking base sequence effects on their repair efficiency in the following order: NarI-G2G3 > NarI-G1G3 > NarI-G1G2. The nuclear magnetic resonance, circular dichroism, ultraviolet melting, and molecular dynamics simulation results revealed that in contrast to the monoadducts, diadducts produced a synergistic effect on duplex destabilization. In addition, dG-FAAF at G2G3 and G1G3 destacks the neighboring bases, with greater destabilization occurring with the former. Overall, the results indicate the importance of base stacking and related thermal and thermodynamic destabilization in the repair of bulky cluster arylamine DNA adducts.
Assuntos
2-Acetilaminofluoreno/química , Adutos de DNA/metabolismo , Desoxirribonucleases de Sítio Específico do Tipo II/metabolismo , Endodesoxirribonucleases/metabolismo , Proteínas de Escherichia coli/metabolismo , Escherichia coli/metabolismo , Pareamento de Bases , Sequência de Bases , Análise por Conglomerados , Adutos de DNA/química , Reparo do DNA , Desoxirribonucleases de Sítio Específico do Tipo II/química , Desoxirribonucleases de Sítio Específico do Tipo II/genética , Simulação de Dinâmica Molecular , Mutação , Oligodesoxirribonucleotídeos/síntese química , Oligodesoxirribonucleotídeos/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , TermodinâmicaRESUMO
A SARS-CoV-2 virus has spread around the globe since March 2020. Millions of people infected worldwide with coronavirus. People from every country expressed their sentiments about coronavirus on social media. The aim of this work is to determine the general public opinion of Indian Twitter users about coronavirus. The Hindi tweets posted about COVID-19 is used as input data for sentiment analysis. The natural language processing is applied on input data for feature extraction. Further, the optimal features are selected from the pre-processed data using the metaheuristic based Grey wolf optimization technique. Finally, a hybrid of convolution neural network(CNN) and a long short-term memory (LSTM) model pair is employed to categorize the sentiments as positive, negative, and neutral. The outcome of the proposed model is compared with other machine learning techniques, namely, Random Forest, Decision Tree, K-Nearest Neighbor, Naive Bayes, Support vector machine (SVM), CNN, LSTM, LSTM-CNN, and CNN-LSTM. The highest accuracy of 87.75%, 88.41%, 87.89%, 85.54%, 89.11%, 91.46%, 88.72%, 91.54%, and 92.34% is obtained by Random Forest, Decision Tree, K-Nearest Neighbor, Naive Bayes, SVM, CNN, LSTM, LSTM-CNN, and CNN-LSTM, respectively. The proposed ensemble hybrid model gives the highest 95.54%, 91.44%, 89.63%, and 90.87% classification accuracy, precision, recall, and F-score, respectively.
RESUMO
In light of increasing concerns about climate change and energy security, renewable energy has been seen as the most promising solution to fulfil future energy needs. This study examines the drivers of renewable energy consumption (REC) and the nexus between GDP growth, technological innovation, gross fixed capital formation, CO2 emissions, income inequality, and renewable energy consumption (REC) using annual data from BRICS countries. To this end, the study uses the augmented mean group (AMG) estimator, a second-generation estimator that takes slope homogeneity and cross-sectional dependence into consideration. For robustness, the pooled mean group (PMG) estimator has also been utilized. The findings of both estimators indicate that carbon emissions, technological innovation, and gross fixed capital formation exert adverse and significant impacts on REC. The findings also show that the use of renewable energy will rise as income inequality declines. We also employ the Dumitrescu and Hurlin (DH) granger causality test. The results of the analysis demonstrate a one-way causal association between income inequality and REC. This finding confirms that a reduction in income inequality will have a major impact on the adoption of renewable energy sources.
Assuntos
Desenvolvimento Econômico , Invenções , Estudos Transversais , Dióxido de Carbono , Energia RenovávelRESUMO
Background: Oral lichen planus is a T-cell-mediated chronic inflammatory disease affecting approximately 1% to 2% of the population, the etiology of which is currently unknown. The objectives of this study were to observe if senescence occurs in oral lichen planus, through the assessment of the immunohistochemical expression of a novel marker for senescence called Senescence marker protein-30 or regucalcin, and compare the expression to that in oral lichenoid reaction and non-specific inflammation. Subjects and Methods: The study material consisted of 30 cases of oral lichen planus, 15 cases of oral lichenoid reaction and 15 cases of non-specific inflammation. The number of positive cells in ten randomly selected high power fields were counted in the epithelium and the connective tissue separately and the mean was determined. Results: Mann-Whitney U test was used to statistically analyze if there was any significant difference in the expression of Senescence marker protein-30 between oral lichen planus, oral lichenoid reaction and non-specific inflammation. Even though a greater expression was seen in the oral lichen planus cases than oral lichenoid reaction, the difference in both the epithelium and connective tissue was not statistically significant. Conclusion: This study shows that in addition to the already known mechanisms like apoptosis and increased cell proliferation rates, the activated T-lymphocytes may also trigger a senescent change in the cells of oral lichen planus. As with the other mechanisms, this is also seen only in a small proportion of the cases.
Assuntos
Líquen Plano Bucal , Erupções Liquenoides , Doenças da Boca , Humanos , Epitélio , Inflamação , Erupções Liquenoides/metabolismo , Mucosa BucalRESUMO
Periodontal diseases significantly impact about half of the global population, and their treatment often encompasses relieving symptoms as well as regenerating the destroyed tissues. Revolutionary research in the management of periodontal disease includes biomaterials, a boon to re-generative dentistry owing to their excellent biological properties: non-toxicity, anti-inflammatory, biocompatibility, biodegradability, and adhesion. This study aimed to fabricate an injectable fucoidan containing chitosan hydrogel and prove its effectiveness in periodontal bone regeneration. The injectable hydrogel was prepared using the sol-gel method and was subjected to various physical, chemical, and biological characterizations to understand its efficacy in formation of new bone. The effectiveness of the developed hydrogel was assessed in periodontal bony defects to study the soft and hard tissue changes. A total of 40 periodontitis patients with bony defects were recruited and randomized into two groups to receive fucoidan-chitosan hydrogel and concentrated growth factor, respectively. Customized acrylic stents were used to guide the hydrogel placement into the defect site. Post-surgical changes in clinical parameters were assessed at 3, 6, and 9 months to appreciate the soft and hard tissue changes using repeated measures analysis of variance and Bonferroni's post hoc test. Significance was kept at 5%. The porosity, water uptake of the prepared hydrogel showed good efficacy, with particle size of the fucoidan containing chitosan hydrogel of 6.000 nm. The MG-63 osteoblasts cell line revealed biocompatibility, biodegradability and showed slow and sustained drug release, increased cell proliferation, and enhanced alkaline phosphatase secretion. Mineralization assay was greatest in the fucoidan containing chitosan hydrogel. Clinically, it exhibited significantly lower probing depth values and a higher mean improvement in clinical attachment level as compared to the concentrated growth factor (CGF) group at the end of 3 and 6 months (p < 0.05). The mean of the defect fills in the fucoidan containing chitosan group was 1.20 at the end of 9 months (p < 0.001) as compared with defect fills observed in the CGF group. The presence of fucoidan in the hydrogel significantly contributed to bone regeneration in humans, thus strengthening its potential in tissue engineering. Fucoidan-chitosan will be a promising biomaterial for bone tissue regeneration.
RESUMO
All around the world, but particularly in developing nations, carbon dioxide emissions are on the rise, and climate change and global warming are brought on by an increase in CO2 emissions. This article provides an overview of the technological effect on energy consumption in the residential, transport, and industrial sector and its ultimate effect on the environment. Using the STIRPAT-Kaya-EKC model for the years 1990 to 2020, this study looked at the threshold impact of technological advancements on the link between disaggregated energy use and CO2 emissions for a panel of 10 Asian countries using the panel threshold regression. Findings demonstrate that the EKC phenomenon is present in the chosen Asian region. Findings also suggest that technology has a threshold influence on the relationship between energy use and carbon emissions; however, this effect varies across sectors.
Assuntos
Dióxido de Carbono , Desenvolvimento Econômico , Dióxido de Carbono/análise , Ásia , Tecnologia , Indústrias , Energia RenovávelRESUMO
The purpose of this study is to examine the impact of green tax incentives such as investment tax credit and taxable income deductions related to the environmental sustainability and climate change which are becoming more popular in developing countries, whereas introducing green tax incentives related to the environment and climate change helps and meets the sustainability objectives of growth and development. For this purpose, we selected the top 100 listed companies on the Swedish stock market (SSM), Nasdaq Stockholm (SN), in order to better understand the real facts and figures of green tax environment. This study uses a longitudinal research design because sample observations vary across firms and over a short time and conducts probit and logistic regression to identify the beneficiaries of the tax incentives. The findings show that different firm-level characteristics significantly impact the probability of being an ITC beneficiary.