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1.
Int J Biol Macromol ; 270(Pt 1): 132048, 2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38704062

RESUMO

Polysaccharides are favourable and promising biopolymers for wound care applications due to their abundant natural availability, low cost and excellent biocompatibility. They possess different functional groups, such as carboxylic, hydroxyl and amino, and can easily be modified to obtain the desirable properties and various forms. This review systematically analyses the recent progress in polysaccharides derived materials for wound care applications, emphasizing the most commonly used cellulose, chitosan, alginate, starch, dextran and hyaluronic acid derived materials. The distinctive attributes of each polysaccharide derived wound care material are discussed in detail, along with their different forms, i.e., films, membranes, sponges, nanoemulsions, nanofibers, scaffolds, nanocomposites and hydrogels. The processing methods to develop polysaccharides derived wound care materials are also summarized. In the end, challenges related to polysaccharides derived materials in wound care management are listed, and suggestions are given to expand their utilization in the future to compete with conventional wound healing materials.

2.
Eur J Pharm Sci ; 198: 106797, 2024 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-38735401

RESUMO

The multicomponent etiology, complex clinical implications, dose-based side effect and degree of pain mitigation associated with the current pharmacological therapy is incapable in complete resolution of chronic neuropathic pain patients which necessitates the perpetual requirement of novel medication therapy. Therefore, this study explored the ameliorative aptitude of two novel methanimine imitative like (E)-N-(4-nitrobenzylidene)-4­chloro-2-iodobenzamine (KB 09) and (E)-N-(4-methylbenzylidene)-4­chloro-2-iodobenzamine (KB 10) in chronic constriction injury (CCI) of sciatic nerve induced neuropathic pain in rat model. Standard behavioral tests like dynamic and static allodynia, cold, thermal and mechanical hyperalgesia along with rotarod activity were performed at various experimental days like 0, 3, 7, 14 and 21. Enzyme linked immunosorbent assay (ELISA) on spinal tissue and antioxidant assays on sciatic nerve were executed accompanied by molecular docking and simulation studies. Prolonged ligation of sciatic nerve expressively induced hyperalgesia as well as allodynia in rats. KB 09 and KB 10 substantially attenuated the CCI elicited hyperalgesia and allodynia. They significantly reduced the biomarkers of pain and inflammation like Interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) in ELISA and while enhanced the GSH, SOD and CAT and diminished the MDA levels during antioxidant assays. KB 09 displayed -9.62 kcal/mol with TNF-α and -7.68 kcal/mol binding energy with IL-6 whereas KB 10 exhibited binding energy of -8.20 kcal/mol with IL-6 while -11.68 kcal/mol with TNF-α and hence both trial compounds ensured stable interaction with IL-6 and TNF-α during computational analysis. The results advocated that both methanimine derivatives might be novel candidates for attenuation of CCI-induced neuropathic pain prospects via anti-nociceptive, anti-inflammatory and antioxidant mechanisms.

3.
Cureus ; 16(4): e58380, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38756297

RESUMO

Pharmacomechanical therapy and catheter-directed thrombolysis are potent treatments for venous thromboembolism. However, limited data exist regarding the management of thrombi in the inferior vena cava (IVC). IVC thrombus resulting from tumors is a particularly uncommon condition. Managing IVC tumor thrombi poses even greater challenges, as conventional therapies such as systemic anticoagulation and thrombolysis are often ineffective. In this report, we present the case of a 73-year-old male with an inferior vena cava tumor thrombus successfully managed through aspiration thrombectomy utilizing the Inari FlowTriever system.

4.
Biomed Pharmacother ; 174: 116544, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38599058

RESUMO

The current study was designed to investigate the potential of a synthetic therapeutic agent for better management of pain and inflammation, exhibiting minimal to non-existent ulcerogenic effects. The effect of 1-(2-chlorobenzoyl)-3-(2,3-dichlorophenyl) thiourea was assessed through model systems of nociception and anti-inflammatory activities in mice. In addition, the ulcerogenic potential was evaluated in rats using the NSAID-induced pyloric ligation model, followed by histopathological and biochemical analysis. The test was conducted on eight groups of albino rats, comprising of group I (normal saline), groups II and III (aspirin® at doses of 100 mg/kg and 150 mg/kg, respectively), groups IV and V (indomethacin at doses of 100 mg/kg and 150 mg/kg, respectively), and groups VI, VII, and VIII (lead-compound at 15 mg/kg, 30 mg/kg and 45 mg/kg doses, respectively). Furthermore, molecular docking analyses were performed to predict potential molecular target site interactions. The results showed that the lead-compound, administered at doses of 15, 30, and 45 mg/kg, yielded significant reductions in chemically and thermally induced nociceptive pain, aligning with the levels observed for aspirin® and tramadol. The compound also effectively suppressed inflammatory response in the carrageenan-induced paw edema model. As for the ulcerogenic effects, the compound groups displayed no considerable alterations compared to the aspirin® and indomethacin groups, which displayed substantial increases in ulcer scores, total acidity, free acidity, and gastric juice volume, and a decrease in gastric juice pH. In conclusion, these findings suggest that our test compound exhibits potent antinociceptive, anti-inflammatory properties and is devoid of ulcerogenic effects.


Assuntos
Inflamação , Simulação de Acoplamento Molecular , Nociceptividade , Úlcera Gástrica , Tioureia , Animais , Úlcera Gástrica/induzido quimicamente , Úlcera Gástrica/patologia , Úlcera Gástrica/tratamento farmacológico , Tioureia/análogos & derivados , Tioureia/farmacologia , Masculino , Nociceptividade/efeitos dos fármacos , Camundongos , Inflamação/tratamento farmacológico , Inflamação/patologia , Ratos , Ratos Wistar , Analgésicos/farmacologia , Analgésicos/química , Anti-Inflamatórios não Esteroides/farmacologia , Anti-Inflamatórios não Esteroides/química , Simulação por Computador , Mucosa Gástrica/efeitos dos fármacos , Mucosa Gástrica/patologia , Mucosa Gástrica/metabolismo , Indometacina/farmacologia , Dor/tratamento farmacológico , Dor/induzido quimicamente , Dor/patologia , Anti-Inflamatórios/farmacologia
5.
Cureus ; 16(3): e57110, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38686255

RESUMO

Background Typhoid fever presents a significant challenge in developing nations, exacerbated by the emergence of antibiotic-resistant strains due to widespread prevalence and overuse of antibiotics. This study seeks to assess the antibiogram profiles of Salmonella species isolated from blood cultures of patients hospitalized at two prominent tertiary care hospitals in Peshawar, Pakistan: Khyber Teaching Hospital (KTH) and Hayatabad Medical Complex (HMC). By examining these profiles, the research aims to provide valuable insights into the evolving landscape of antibiotic resistance in the context of typhoid fever management. Materials and Methods This retrospective cross-sectional study utilized data gathered from two hospitals in Peshawar, KTH and HMC. Cases of enteric fever were identified based on positive blood cultures for Salmonella species. The study encompasses demographic information, seasonal prevalence, and antibiogram profiles of 3,137 cases that were presented between 2017 and 2023. Results Among the total 3,137 cases, males accounted for the majority, comprising 63% (2,044 cases). Particularly notable was the clustering of cases among children and adolescents aged one to 24 years. The incidence peaked during the months of summer and spring, from April to September. In terms of Salmonella Typhi isolates, considerable resistance was noted against first-line antibiotics such as amoxicillin/clavulanate (80.1%), co-trimoxazole/trimethoprim-sulfamethoxazole (66.6%), and chloramphenicol (86.9%), as well as against ceftriaxone (79.7%) and ciprofloxacin (51.6%). Conversely, certain antibiotics displayed higher sensitivity patterns, including meropenem (97.8%), doripenem (99.5%), imipenem (97.7%), ertapenem (96.5%), polymyxin B (99.4%), colistin (98.1%), and tigecycline (97.3%). Despite a limited sample size of 214 specimens, fosfomycin demonstrated a remarkable sensitivity of 93.4%. Sensitivities of amikacin and gentamicin were 90.7% and 81.5%, respectively. However, the sensitivity of azithromycin was concerning, standing at 66.5%. The antibiogram pattern for Salmonella exhibited significant and drastic changes. Conclusion In conclusion, this study sheds light on a higher prevalence of typhoid fever among males, with a notable seasonal peak observed during the summer and spring months. The age group most affected spans from one to 24 years. Salmonella isolates displayed significant resistance to conventional first-line antibiotics, alongside ciprofloxacin and third-generation cephalosporins. Azithromycin exhibited lower sensitivity compared to amikacin, gentamicin, and fosfomycin. The research advocates for the empirical use of amikacin, gentamicin, fosfomycin, and meropenem in the treatment of typhoid fever in Pakistan. Urgent measures, including regular Salmonella antibiogram surveillance, antibiotic stewardship, public health education, and Salmonella vaccination programs, are deemed crucial for primary disease prevention.

6.
AoB Plants ; 16(2): plae018, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38601216

RESUMO

Humic acids have been widely used for centuries to enhance plant growth and productivity. The beneficial effects of humic acids have been attributed to different functional groups and phytohormone-like compounds enclosed in macrostructure. However, the mechanisms underlying the plant growth-promoting effects of humic acids are only partially understood. We hypothesize that the bio-stimulatory effect of humic acids is mainly due to the modulation of innate pathways of auxin and cytokinin biosynthesis in treated plants. A physiological investigation along with molecular characterization was carried out to understand the mechanism of bio-stimulatory effects of humic acid. A gene expression analysis was performed for the genes involved in auxin and cytokinin biosynthesis pathways in wheat seedlings. Furthermore, Arabidopsis thaliana transgenic lines generated by fusing the auxin-responsive DR5 and cytokinin-responsive ARR5 promoter to ß-glucuronidase (GUS) reporter were used to study the GUS expression analysis in humic acid treated seedlings. This study demonstrates that humic acid treatment improved the shoot and root growth of wheat seedlings. The expression of several genes involved in auxin (Tryptophan Aminotransferase of Arabidopsis and Gretchen Hagen 3.2) and cytokinin (Lonely Guy3) biosynthesis pathways were up-regulated in humic acid-treated seedlings compared to the control. Furthermore, GUS expression analysis showed that bioactive compounds of humic acid stimulate endogenous auxin and cytokinin-like activities. This study is the first report in which using ARR5:GUS lines we demonstrate the biostimulants activity of humic acid.

7.
Plant Physiol ; 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38445796

RESUMO

Low-temperature sensitivity at the germination stage is a challenge for direct seeding of rice in Asian countries. How Ca2+ and IAA signaling regulate primary root growth under chilling remains unexplored. Here, we showed that OsCML16 interacted specifically with OsPILS7a to improve primary root elongation of early rice seedlings under chilling. OsCML16, a subgroup 6c member of the OsCML family, interacted with multiple cytosolic loop regions of OsPILS7a in a Ca2+-dependent manner. OsPILS7a localized to the ER membranes and functioned as an auxin efflux carrier in a yeast growth assay. Transgenics showed that presence of OsCML16 enhanced primary root elongation under chilling, whereas the ospils7a knockout mutant lines showed the opposite phenotype. Moreover, under chilling conditions, OsCML16 and OsPILS7a mediated Ca2+ and IAA signaling and regulated the transcription of IAA signaling-associated genes (OsIAA11, OsIAA23, and OsARF16) and cell division marker genes (OsRAN1, OsRAN2, and OsLTG1) in primary roots. These results show that OsCML16 and OsPILS7a cooperatively regulate primary root elongation of early rice seedlings under chilling. These findings enhance our understanding of the crosstalk between Ca2+ and IAA signaling and reveal insights into the mechanisms underlying cold-stress response during rice germination.

8.
Heliyon ; 10(4): e26149, 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38384569

RESUMO

Biomedical image analysis plays a crucial role in enabling high-performing imaging and various clinical applications. For the proper diagnosis of blood diseases related to red blood cells, red blood cells must be accurately identified and categorized. Manual analysis is time-consuming and prone to mistakes. Analyzing multi-label samples, which contain clusters of cells, is challenging due to difficulties in separating individual cells, such as touching or overlapping cells. High-performance biomedical imaging and several medical applications are made possible by advanced biosensors. We develop an intelligent neural network model that can automatically identify and categorize red blood cells from microscopic medical images using region-based convolutional neural networks (RCNN) and cutting-edge biosensors. Our model successfully navigates obstacles like touching or overlapping cells and accurately recognizes various blood structures. Additionally, we utilized data augmentation as a pre-processing method on microscopic images to enhance the model's computational efficiency and expand the sample size. To refine the data and eliminate noise from the dataset, we utilized the Radial Gradient Index filtering algorithm for imaging data equalization. We exhibit improved detection accuracy and a reduced model loss rate when using medical imagery datasets to apply our proposed model in comparison to existing ResNet and GoogleNet models. Our model precisely detected red blood cells in a collection of medical images with 99% training accuracy and 91.21% testing accuracy. Our proposed model outperformed earlier models like ResNet-50 and GoogleNet by 10-15%. Our results demonstrated that Artificial intelligence (AI)-assisted automated red blood cell detection has the potential to revolutionize and speed up blood cell analysis, minimizing human error and enabling early illness diagnosis.

9.
Int J Biol Macromol ; 261(Pt 2): 129764, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38296144

RESUMO

In this study, Hydroxyapatite nanoparticles (HANPs), derived from eggshell waste, were employed to reinforce chitosan biopolymer-based films through the solvent-casting method. The impact of varying HANPs content (1%, 3%, 5%, and 10 wt %) in bionanocomposites was investigated. The influence of HANPs addition on the final film properties was comprehensively analyzed using Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), Dynamic Mechanical Analysis (DMA), mechanical (tensile) testing, and Water Vapor Permeability (WVP). The morphological aspects of bionanocomposites and the dispersion of nanoparticles within the matrix were studied using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and X-ray Diffraction (XRD). The structural changes in the films were probed using Fourier-Transform Infrared Spectroscopy (FTIR) and X-ray Photoelectron Spectroscopy (XPS) techniques. Results indicated that the addition of 1% and 3% of HANPs exhibited a higher glass transition temperature and improved thermal stability in bionanocomposites. Films with 3% HANPs content exhibited a notable increase in tensile strength, showing a 61.54% increase, while films with 1% HANPs content displayed a 52% reduction in WVP compared to pristine chitosan films. These findings underscore the significant potential of chitosan-hydroxyapatite bionanocomposite films for applications in food packaging applications.


Assuntos
Quitosana , Nanopartículas , Animais , Quitosana/química , Durapatita , Casca de Ovo , Resistência à Tração , Nanopartículas/química
10.
Heliyon ; 9(11): e22483, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38074891

RESUMO

Neurodegenerative complications, like Alzheimer's disease (AD) exert adverse effects i.e. psychological and physiological in the central nervous system. The synthetic drugs used for these complications have negative effects on body health and therefore natural remedies are a good and targeted approach to counter such complications. Alternatively, fruits and a variety of biochemicals which are an important source of diet, can be used for remedial purposes. Due to the antioxidant properties of polyphenolic compounds, several companies utilize this property to advertise polyphenol-rich beverages. Pomegranate (Punica granatum L.), is one such fruit that is well known for its medical usage due to its antioxidant properties. In the cuurent study a literature search survey was performed on traditional uses, phytochemicals on pomegranate and their medical applications especaily in neurodegenerative deasese using electronic data bases like PubMed, Google Scholar, Scopus, Science Direct Wikipedia and Springer Nature. Based on previous preclinical and clinical studies, pomegranate juice, extracts, and its bioactive constituents have shown many mitigating properties, including suppression of inflammatory cell signaling, reduction in expression of genes associated with oxidative stress as well as pro-inflammatory cytokines in neurons, decreased production of inflammatory and oxidative stress biomarkers and increased expression of endothelial nitric oxide synthase. It also decreases the expression of soluble amyloid protein procurer ß (sAPPß), ß-secretase and carboxyl terminal fragment ß (CTFß). Similarly, during an in-vivo study on APP/PS1 mice, pomegranate supplementation has been shown to impart cognitive aid by the protection of neurons and triggering neurogenesis through anti-inflammatory signaling pathway. In conclusion, pomegranate supplementation can be a promising source of protection against Alzheimer's disease.

11.
J Ethnobiol Ethnomed ; 19(1): 62, 2023 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-38105177

RESUMO

BACKGROUND: In multicultural societies, traditional knowledge among minorities faces several challenges. Minority groups often face difficult situations living in specific peripheral geographies and striving to retain their biocultural heritage, including medicinal plant knowledge and practices. Folk medicinal plant knowledge is a dynamic eco-cultural complex influenced by various environmental, socio-cultural, and political factors. Examining medicinal plant knowledge among minorities has been an increasingly popular topic in cross-cultural ethnobiology. It also helps understand the dynamics of local/traditional ecological knowledge (LEK/TEK) change within a given community. The current study was designed to investigate the status of medicinal plant knowledge among two linguistic groups, i.e. Ormurs and Pathans, living in a remote valley of West Pakistan. METHODS: We recruited 70 male study participants from the studied groups for semi-structured interviews to record the medicinal plant use of their communities. Data were compared among the two studied communities using the stacked charts employing the presence or absence of data with Past 4.03 and Venn diagrams. Use reports (URs) were counted for each recorded taxon. RESULTS AND DISCUSSION: A total of seventy-four medicinal plants were quoted as used as ethnomedicines by the researched communities. Most of the reported plants were used to treat digestive and liver problems. The cross-cultural comparison revealed a considerable homogeneity of medicinal plant knowledge (the two groups commonly used more than seventy plants); however, comparing uses recorded for the widely utilised medicinal plants showed numerous idiosyncratic uses among Ormurs but very few among Pathans. Ormurs reported a higher number of cultivated, wild, and imported plant uses than did Pathans. These results indicate that, compared to Pathans, the Ormur linguistic minority retain more folk medicinal plant knowledge, which may be explained by the fact that they have incorporated different folk remedies: their "own knowledge" plus that of Pathans, with whom they have lived together for centuries. Moreover, the local plant nomenclature among Ormurs was highly affected by the plant nomenclature of Pathans. CONCLUSION: The current study revealed that living together for a few centuries has not implied sharing plant knowledge (as the Pathans do not seem to have learnt from the Ormurs) or, in other words, that plant knowledge exchanges have been unidirectional. The findings show that the Pashto dominant culture may have possibly put pressure on the minority groups and affected local plant-centred cultural practices, as we see in the case of local plant nomenclature hybridisation among Omuri speakers. Hence, it is imperative to employ diverse educational strategies to revitalise the decline of medicinal plant knowledge in the studied communities, especially among Ormurs, who need more attention as they face more challenges than the other group. Locally based strategies should be devised to restore the fading connection with nature, which will be advantageous for revitalising plant knowledge.


Assuntos
Plantas Medicinais , Humanos , Etnobotânica , Paquistão , Medicina Tradicional/métodos , Fitoterapia
12.
Neurotoxicology ; 99: 274-281, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37939858

RESUMO

Ethanol administration triggers an inflammatory response that leads to a complex series of immune responses including the release of an excessive amount of inflammatory mediators particularly tumor necrosis factor (TNF-α) and nuclear factor-kB (NF-KB) which produce a large amount of reactive oxygen species. The inflammatory-induced cytotoxicity is increased when the PI3-kinase/Akt pathway is inhibited. Some studies have also shown that ethanol suppresses the PI3-kinase signaling pathway induced by receptor activation. Friedelin and Glutinol belong to pentacyclic triterpenoid class and are known for their anti-inflammatory and antioxidant properties. The present study was aimed to elucidate the effects of these phytoconstituents on one of the key ethanol-induced neuronal damage pathways. The pups having (5-7 g average body weight) were used and randomly divided into groups. The control and ethanol treated pups were administered 0.9% normal saline while treated pups received glutinol and friedelin (30 mg/kg subcutaneously) respectively. After four hours all the experimental animals were sacrificed and their brains were collected carefully for protein expression analysis of p-Akt, TNF-α, NF-KB, caspase-3 and PARP-1 employing immunoblotting technique. Hemolytic, DNA protection, chelating power and ß-carotene assays results revealed that freidelin and glutinol are safe for parenteral administration. Glutinol administration with ethanol significantly abridged the ethanol induced over expression of TNF-α, caspase-3 and PARP-1 in pup's brain. Similarly, freidelin attenuated the neurodegeneration by inhibiting the ethanol induced p-JNK and NF-kB expression in pups' brain. This protection may be attributed to the revival of p-Akt signaling for cell survival. It is concluded that the present study demonstrates the neuro-protective effects of friedelin and glutinol via modulating the capase-3 and PARP-1 expression and modulating the neuronal apoptotic pathways.


Assuntos
Lupanos , NF-kappa B , Neuroproteção , Fator de Necrose Tumoral alfa , Animais , Encéfalo , Caspase 3/metabolismo , Etanol/toxicidade , NF-kappa B/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Poli(ADP-Ribose) Polimerases/metabolismo , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Lupanos/farmacologia
13.
Carbohydr Polym ; 321: 121318, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37739510

RESUMO

The attention to polymer-based biomaterials, for instance, chitosan and its derivatives, as well as the techniques for using them in numerous scientific domains, is continuously rising. Chitosan is a decomposable naturally occurring polymeric material that is mostly obtained from seafood waste. Because of its special ecofriendly, biocompatible, non- toxic nature as well as antimicrobial properties, chitosan-based materials have received a lot of interest in the field of biomedical applications. The reactivity of chitosan is mainly because of the amino and hydroxyl groups in its composition, which makes it further fascinating for various uses, including biosensing, textile finishing, antimicrobial wound dressing, tissue engineering, bioimaging, gene, DNA and drug delivery and as a coating material for medical implants. This study is an overview of the different types of chitosan-based materials which now a days have been fabricated by applying different techniques and modifications that include etherification, esterification, crosslinking, graft copolymerization and o-acetylation etc. for hydroxyl groups' processes and acetylation, quaternization, Schiff's base reaction, and grafting for amino groups' reactions. Furthermore, this overview summarizes the literature from recent years related to the important applications of chitosan-based materials (i.e., thin films, nanocomposites or nanoparticles, sponges and hydrogels) in different biomedical applications.


Assuntos
Quitosana , Esterificação , Materiais Biocompatíveis/farmacologia , Acetilação , Bandagens , Polímeros
14.
Sci Rep ; 13(1): 13006, 2023 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-37563284

RESUMO

The high-precision machine tool's dynamic, static, and rigid nature directly affects the machining efficiency and surface quality. Static and dynamic analyses are essential for the design and improvement of precision machine to ensure good tool performance under difficult and demanding machining conditions. In this study, the performance of a high-precision machine tool was analyzed using its virtual model created using CAD. Static and model analysis using ANSYS Workbench software was conducted to establish the tool's static deformation and static stiffness. Furthermore, the static and dynamic characteristics of the tool were explored using a finite element modeling approach to study their performance. In particular, the structure, static force, modal, frequency spectrum, and topology optimization of machine tools were primarily analyzed. Using model analysis, we found the first four different frequencies (22.5, 28.9, 40.6, and 47.4 Hz) and vibration type, which suggested of a weak link. Further static structural analysis revealed that the deformation of the spindle was 67.26 µm. An experimental static rigidity analysis was performed, and the experimental deformation values of the tool and spindle were obtained. The static and dynamic characteristics, as well as the accuracy and efficiency of the finite element model, were verified by comparing the data with the finite element analysis (FEA) results. Subsequently, we modified the settings and analysis model to ensure that the analysis results were consistent with the experimental findings. The error between the two results was within 1.56%. For an applied load of 5000 N on the spindle nose, the tool nose transient response was 0.5 s based on transient analysis. Under the condition that the structural deformation is as constant as possible, the lightweight structure may achieve the minimum weight and enhance the natural frequency; thus, the ideal structure will be obtained, and finite element analysis will then be performed. The optimal conditions for topology optimization include a lightweight structure, reduced structural deformation, and increased natural frequency of the structure. The developed method improves structural optimization, increases the ability of the product to be manufactured, and offers designers a variety of price-effective options.

15.
Biomolecules ; 13(8)2023 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-37627324

RESUMO

Calcium (Ca2+) sparks are the elementary events of excitation-contraction coupling, yet they are not explicitly represented in human ventricular myocyte models. A stochastic ventricular cardiomyocyte human model that adapts to intracellular Ca2+ ([Ca2+]i) dynamics, spark regulation, and frequency-dependent changes in the form of locally controlled Ca2+ release was developed. The 20,000 CRUs in this model are composed of 9 individual LCCs and 49 RyRs that function as couplons. The simulated action potential duration at 1 Hz steady-state pacing is ~0.280 s similar to human ventricular cell recordings. Rate-dependence experiments reveal that APD shortening mechanisms are largely contributed by the L-type calcium channel inactivation, RyR open fraction, and [Ca2+]myo concentrations. The dynamic slow-rapid-slow pacing protocol shows that RyR open probability during high pacing frequency (2.5 Hz) switches to an adapted "nonconducting" form of Ca2+-dependent transition state. The predicted force was also observed to be increased in high pacing, but the SR Ca2+ fractional release was lower due to the smaller difference between diastolic and systolic [Ca2+]SR. Restitution analysis through the S1S2 protocol and increased LCC Ca2+-dependent activation rate show that the duration of LCC opening helps modulate its effects on the APD restitution at different diastolic intervals. Ultimately, a longer duration of calcium sparks was observed in relation to the SR Ca2+ loading at high pacing rates. Overall, this study demonstrates the spontaneous Ca2+ release events and ion channel responses throughout various stimuli.


Assuntos
Artrogripose , Sinalização do Cálcio , Humanos , Miócitos Cardíacos , Potenciais de Ação , Ventrículos do Coração
16.
Environ Sci Pollut Res Int ; 30(44): 99713-99734, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37620693

RESUMO

This study examines the validity of the environmental Kuznets curve (EKC) hypothesis and the role of environmental regulation, renewable electricity, industrialization, economic complexity, and technological innovation in sustainable environment for the G-10 economies, namely, Belgium, Canada, Germany, Italy, Japan, Netherlands, Sweden, Switzerland, the United Kingdom, and the USA, from 1994 to 2020. We employed CS-ARDL (cross-sectional augmented distributed lag (CS-ARDL), FMOLS (fully modified ordinary least squares), and DOLS (dynamic ordinary least squares) for the analysis of the data. The estimates confirm the N-shaped EKC hypothesis between the GDP and CO2 emission. Moreover, the long-run estimates exhibit that environmental tax, renewable electricity, economic complexity, and technological innovation have negative effect on CO2 emission, while GDP, industrialization and arable land have positive effect on CO2 emission. Based on these findings, we propose that governments must implement large-scale government plans and initiatives to encourage the development of environmentally friendly technologies and ideas based on renewable energy. Moreover, further growing renewable energy, environmental policies like a carbon tax, investments in green technologies, subsidies, and rewards for renewable energy infrastructure investment should be taken into account.


Assuntos
Desenvolvimento Industrial , Invenções , Desenvolvimento Econômico , Dióxido de Carbono , Estudos Transversais , Energia Renovável
17.
Sci Total Environ ; 891: 164288, 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37211135

RESUMO

Keratin has become a promising adsorbing material for the removal of heavy metals from polluted water due to its environmentally benign nature, unique chemical structure, and binding ability. We developed keratin biopolymers (KBP-I, KBP-IV, KBP-V) using chicken feathers, and assessed their adsorption performance against metal-containing synthetic wastewater at varying temperatures, contact times, and pH. Initially, a multi-metal synthetic wastewater (MMSW) containing cations (Cd2+, Co2+, Ni2+) and oxyanions (CrVI, AsIII, VV) was incubated with each KBP under different sets of conditions. Temperature results exhibited that KBP-I, KBP-IV and KBP-V showed higher metals adsorption at 30 °C and 45 °C, respectively. However, the adsorption equilibrium was achieved for selective metals within 1 h of incubation time for all KBPs. For pH, no significant difference was observed in adsorption in MMSW due to buffering of pH by KBPs. To minimize buffering, KBP-IV and KBP-V were tested further for single-metal synthetic wastewater at two different pHs i.e. 5.5 and 8.5. KBP-IV and KBP-V were selected due to their buffering capacities and high adsorption abilities for oxyanions (pH 5.5) and divalent cations (pH 8.5), respectively indicating that chemical modifications changed and enhanced the functional groups of the keratin. X-ray Photoelectron Spectroscopy analysis was performed to demonstrate the adsorption mechanism (complexation/chelation, electrostatic attraction, or chemical reduction) for the removal of divalent cations and oxyanions by KBPs from MMSW. Furthermore, KBPs exhibited adsorption behavior for Ni2+ (qm = 2.2 mg g-1), Cd2+ (qm = 2.4 mg g-1), and CrVI (qm = 2.8 mg g-1) best described by Langmuir model with the coefficient of determination (R2) values >0.95 while AsIII (KF = 6.4 L/g) was fitted well to the Freundlich model with R2 value >0.98. Based on these findings, we anticipate that keratin adsorbents have the potential to employ at a large scale for water remediation.

18.
Int J Biol Macromol ; 241: 124446, 2023 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-37088187

RESUMO

Biosorbents for water remediation were prepared using keratin biopolymer cross-linked with nanochitosan (NC). Keratin proteins were dissolved using reducing agents and NC was incorporated with concentrations of 1, 3 and 5 % individually into the keratin solution. The mixtures were thermally treated at 75°C overnight, which promoted the formation of ester bonds between the hydroxyl groups of nanochitosan and the carboxylic groups of the keratin biopolymer. The resulting keratin derived biosorbents were characterized by X-Ray photoelectron spectroscopy, confirming the cross-linking between keratin and nanochitosan. The chicken feathers keratin (CFK) surface modifications with nanochitosan were examined with Brunauer-Emmett-Teller, scanning and transmission electron microscopies. The sorption capacity of biosorbents was tested for eight different metals simultaneously at different contact times (15, 30, 60, 120, 240, 280 mins) and pH (5.5, 7.5 and 8.5), including arsenic, selenium, chromium, nickel, cobalt, lead, cadmium and zinc, using simulated industrial wastewater water containing 600 µgl-1 concentration of each metal. The synthesized environmentally benign biosorbents exhibited biosorption of metals upto 98 % at pH 7.5 and a contact time of 24 h, showing their potential for industrial wastewater remediation.


Assuntos
Metais Pesados , Poluentes Químicos da Água , Animais , Águas Residuárias , Queratinas/química , Poluentes Químicos da Água/química , Adsorção , Água , Concentração de Íons de Hidrogênio
19.
Polymers (Basel) ; 15(4)2023 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-36850121

RESUMO

Proteins-derived polymeric micelles have gained attention and revolutionized the biomedical field. Proteins are considered a favorable choice for developing micelles because of their biocompatibility, harmlessness, greater blood circulation and solubilization of poorly soluble drugs. They exhibit great potential in drug delivery systems as capable of controlled loading, distribution and function of loaded agents to the targeted sites within the body. Protein micelles successfully cross biological barriers and can be incorporated into various formulation designs employed in biomedical applications. This review emphasizes the recent advances of protein-based polymeric micelles for drug delivery to targeted sites of various diseases. Most studied protein-based micelles such as soy, gelatin, casein and collagen are discussed in detail, and their applications are highlighted. Finally, the future perspectives and forthcoming challenges for protein-based polymeric micelles have been reviewed with anticipated further advances.

20.
Artigo em Inglês | MEDLINE | ID: mdl-36808935

RESUMO

The abundance of CO2 from the cement industry, power generation, petroleum production, and combustion of biomass makes it a readily available feedstock to produce chemicals and materials, although it has yet to achieve optimal development. Even though syngas (CO + H2) hydrogenation to methanol is an established industrial process, when the same catalytic system based on Cu/ZnO/Al2O3 is employed with CO2, the water formed as a byproduct reduces the activity, stability, and selectivity of the process. Here, we explored the potential of phenyl polyhedral oligomeric silsesquioxane (POSS) as a hydrophobic support of Cu/ZnO for direct CO2 hydrogenation to methanol. Mild calcination of the copper-zinc-impregnated POSS material affords the formation of CuZn-POSS nanoparticles with Cu and ZnO homogeneously dispersed with an average particle size of 7 and 15 nm supported on O-POSS and D-POSS, respectively. The composite supported on D-POSS was able to reach a 3.8% yield of methanol with a 4.4% of CO2 conversion and with selectivity as high as 87.5% within 18 h. The structural investigation of the catalytic system reveals that CuO/ZnO are electron withdrawers in the presence of the siloxane cage of POSS. The catalytic system metal-POSS is stable and recyclable under H2 reduction and CO2/H2 conditions. We tested the use of microbatch reactors in heterogeneous reactions as a rapid and effective tool for catalyst screening. The increased number of phenyls in the structure of POSS results in an increased hydrophobic character that plays a decisive role in the methanol formation after comparison with CuO/ZnO supported on reduced graphene oxide with 0% selectivity to methanol under the study conditions. The materials were characterized using scanning electron microscopy, transmission electron microscopy, attenuated total reflection Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, powder X-ray diffraction, Fourier transform infrared analysis, Brunauer-Emmett-Teller specific surface area analysis, contact angle, and thermogravimetry. The gaseous products were characterized by gas chromatography coupled with thermal conductivity detectors and flame ionization detectors.

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