Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.362
Filtrar
2.
Artigo em Inglês | MEDLINE | ID: mdl-38566389

RESUMO

Cancer is a complex disease characterized by the uncontrolled and unregulated growth of cells followed by invasion and proliferation from the site of origin to other sites of the body. Conventional chemotherapy largely kills rapidly expanding and dividing cancer cells by impairing DNA synthesis and mitosis. It is associated with various types of adverse effects ranging from simple nausea and appetite loss to serious ones like bone marrow depression and compromised immunity etc., due to their non-selectivity and inability to differentiate. The ideal feature of a delivery system is delivering the drug to the target place to achieve the most therapeutic impact while having the least toxicity. With the advent of novel drug delivery systems, it has been easier to deliver the drug to the target site. Utilizing new techniques and technology makes it a feasible approach to target cancer cells. Nanoemulsions are isotropic mixtures of transparent or translucent oil globules dispersed in an aqueous phase that is kinetically stable and supported by an interfacial coating of surfactant and co-surfactant molecules with droplet sizes in the nanometre range. Nanoemulsions are the delivery system of choice in case of cancer because of certain key attributes, including biodegradability, biocompatibility, large surface area nonimmunogenicity, and release behavior control. At the same time, nanoemulsions have been engineered for various reasons, including enhanced biological half-life, target-specific binding ability, and imaging capability at different therapy levels by modifying the characteristics of nanoemulsions. This review focuses on current cancer treatment challenges and the role of nanoemulsions in treating cancer with their production methods, characterization methods, application, and quality attributes, which would help them make it to the clinics where cancer treatment is going on.

3.
Tree Physiol ; 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38606678

RESUMO

Worldwide, forests are increasingly exposed to extreme droughts causing tree mortality. Because of the complex nature of the mechanisms involved, various traits have been linked to tree drought responses with contrasting results. This may be due to species-specific strategies in regulating water potential, a process that unfolds in two distinct phases: a first phase until stomatal closure, and a second phase until reaching lethal xylem hydraulic thresholds. We conducted dry-down experiments with five broadleaved temperate tree species differing in their degree of isohydry to estimate the time to stomatal closure (tsc) and subsequent time to critical hydraulic failure (tcrit). We measured various traits linked to tree drought responses, such as the water potentials at turgor loss point (Ptlp), stomatal closure (Pgs90) and 12, 50 and 88% loss of xylem hydraulic conductance (P12, P50, P88), hydraulic capacitance (C), minimum leaf conductance (gmin), hydroscape area (HSA) and hydraulic safety margins (HSM). We found that Pgs90 followed previously recorded patterns of isohydry and was associated with HSA. Species ranked from more to less isohydric in the sequence Acer pseudoplatanus < Betula pendula < Tilia cordata < Sorbus aucuparia < Fagus sylvatica. Their degree of isohydry was associated with leaf safety (Ptlp and gmin), drought avoidance (C) and tsc, but decoupled from xylem safety (HSM and P88) and tcrit. Regardless of their stomatal stringency, species with wider HSM and lower P88 reached critical hydraulic failure later. We conclude that the duration of the first phase is determined by stomatal regulation, while the duration of the second phase is associated with xylem safety. Isohydry is thus linked to water use rather than to drought survival strategies, confirming the proposed use of HSA as a complement to HSM for describing plant drought responses before and after stomatal closure.

4.
Int J Biol Macromol ; 267(Pt 1): 131362, 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38583843

RESUMO

Chitin, recovered in huge amounts from coastal waste, may biocatalytically valorized for utilization in food and biotech sectors. Conventional chemical-based conversion makes use of significant volumes of hazardous acid and alkali. Alternatively, enzymes offer better process control and generation of homogeneous products. Process variables were derived to achieve augmented levels of chitinase (3.8809 Ul-1 h-1) productivity from a novel thermophilic fungal strain Thermomyces dupontii, ITCC 9104 following incubation (96 h, 45 °C). An acidic thermostable chitinase TdChiT having molecular mass of 60 kDa has been purified. Optimal TdChiT activity has been demonstrated at 70 °C and pH 5. Notably decreased activity over a broad range of temperature and pH was observed following deglycosylation. Half-life, activation energy, Gibbs free energy, enthalpy and entropy for denaturation of TdChiT at its optimum temperature were 197.40 min, 105.48 kJ mol-1, 100.59 kJ mol-1, 102.64 kJ mol-1 and 5.95 J mol-1 K-1. TdChiT has specificity towards colloidal chitin and (GlcNAc)2-4. Metal ions viz. Mn2+, Ca2+ and Co2+ and nonionic surfactants notably enhanced chitinase activity. Thin layer chromatography analysis has revealed effective hydrolysis of colloidal chitin and (GlcNAc)2-4. TdChiT may potentially be employed for design of better, eco-friendly and less resource-intensive industrial procedures for upcycling of crustacean waste into value-added organonitrogens.

5.
Arch Microbiol ; 206(5): 209, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38587657

RESUMO

The F-box proteins in fungi perform diverse functions including regulation of cell cycle, circadian clock, development, signal transduction and nutrient sensing. Genome-wide analysis revealed 10 F-box genes in Puccinia triticina, the causal organism for the leaf rust disease in wheat and were characterized using in silico approaches for revealing phylogenetic relationships, gene structures, gene ontology, protein properties, sequence analysis and gene expression studies. Domain analysis predicted functional domains like WD40 and LRR at C-terminus along with the obvious presence of F-box motif in N-terminus. MSA showed amino acid replacements, which might be due to nucleotide substitution during replication. Phylogenetic analysis revealed the F-box proteins with similar domains to be clustered together while some sequences were spread out in different clades, which might be due to functional diversity. The clustering of Puccinia triticina GG705409 with Triticum aestivum TaAFB4/TaAFB5 in a single clade suggested the possibilities of horizontal gene transfer during the coevolution of P. triticina and wheat. Gene ontological annotation categorized them into three classes and were functionally involved in protein degradation through the protein ubiquitination pathway. Protein-protein interaction network revealed F-box proteins to interact with other components of the SCF complex involved in protein ubiquitination. Relative expression analysis of five F-box genes in a time course experiment denoted their involvement in leaf rust susceptible wheat plants. This study provides information on structure elucidation of F-box proteins of a basidiomycetes plant pathogenic fungi and their role during pathogenesis.


Assuntos
Basidiomycota , Proteínas F-Box , Filogenia , Puccinia , Basidiomycota/genética , Proteínas F-Box/genética
6.
Artigo em Inglês | MEDLINE | ID: mdl-38637215

RESUMO

The parasymphysis area of the mandible is highly dynamic because it is subjected to both occlusal and muscular forces. As a result, the fractures in this transition zone have a special pattern, posing a challenge for surgeons whether to use one miniplate versus two miniplates, as per Champy's recommendations. The commonest complication resulting to treat this area is mental nerve paraesthesia due to the dissection and stretching of the nerve. Hence, an in vitro research study of a newly designed 'Zeta' miniplate is performed, to evaluate the biomechanical behaviour using finite element (FE) analysis and biomechanical analysis along with a comparison study with the conventional miniplate configurations. The results showed that the Zeta miniplate produces the lowest stresses 17.511 MPa and the least total structural deformation of 0.0011 mm after applying the maximum occlusal bite force. On application of torsional load, total structural deformation was 0.0004 mm and von Mises (VM) stress value was 0.24 MPa which was lowest when compared with the two miniplate system. Hence, the newly developed Zeta miniplate is superior in terms of stability. Another benefit of its design is that it helps in preventing mental nerve paraesthesia and tooth root damage while fixing and stabilising the fractured bony segments.

8.
Int J Biol Macromol ; 266(Pt 2): 131371, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38580013

RESUMO

Bacterial caseinolytic protease-chaperone complexes participate in the elimination of misfolded and aggregated protein substrates. The spirochete Leptospira interrogans possess a set of Clp-chaperones (ClpX, ClpA, and ClpC), which may associate functionally with two different isoforms of LinClpP (ClpP1 and ClpP2). The L. interrogans ClpC (LinClpC) belongs to class-I chaperone with two active ATPase domains separated by a middle domain. Using the size exclusion chromatography, ANS dye binding, and dynamic light scattering analysis, the LinClpC is suggested to undergo nucleotide-induced oligomerization. LinClpC associates with either pure LinClpP1 or LinClpP2 isoforms non-preferentially and with equal affinity. Regardless, pure LinClpP isoforms cannot constitute an active protease complex with LinClpC. Interestingly, the heterocomplex LinClpP1P2 in association with LinClpC forms a functional proteolytic machinery and degrade ß-casein or FITC-casein in an energy-independent manner. Adding either ATP or ATPγS further fosters the LinClpCP1P2 complex protease activity by nurturing the functional oligomerization of LinClpC. The antibiotic, acyldepsipeptides (ADEP1) display a higher activatory role on LinClpP1P2 protease activity than LinClpC. Altogether, this work illustrates an in-depth study of hetero-tetradecamer LinClpP1P2 association with its cognate ATPase and unveils a new insight into the structural reorganization of LinClpP1P2 in the presence of chaperone, LinClpC to gain protease activity.

9.
Artigo em Inglês | MEDLINE | ID: mdl-38598825

RESUMO

Novel vapor-permeable materials are sought after for applications in protective wear, energy generation, and water treatment. Current impermeable protective materials effectively block harmful agents but trap heat due to poor water vapor transfer. Here we present a new class of materials, vapor permeable dehydrated nanoporous biomimetic membranes (DBMs), based on channel proteins. This application for biomimetic membranes is unexpected as channel proteins and biomimetic membranes were assumed to be unstable under dry conditions. DBMs mimic human skin's structure to offer both high vapor transport and small molecule exclusion under dry conditions. DBMs feature highly organized pores resembling sweat pores in human skin, but at super high densities (>1012 pores/cm2). These DBMs achieved exceptional water vapor transport rates, surpassing commercial breathable fabrics by up to 6.2 times, despite containing >2 orders of magnitude smaller pores (1 nm vs >700 nm). These DBMs effectively excluded model biological agents and harmful chemicals both in liquid and vapor phases, again in contrast with the commercial breathable fabrics. Remarkably, while hydrated biomimetic membranes were highly permeable to liquid water, they exhibited higher water resistances after dehydration at values >38 times that of commercial breathable fabrics. Molecular dynamics simulations support our hypothesis that dehydration induced protein hydrophobicity increases which enhanced DBM performance. DBMs hold promise for various applications, including membrane distillation, dehumidification, and protective barriers for atmospheric water harvesting materials.

10.
Biomater Adv ; 160: 213865, 2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38643693

RESUMO

Microneedle technology offers a minimally invasive treatment strategy to deliver chemotherapeutics to localized tumors. Amalgamating the surface functionalized nanoparticles with microneedle technology can potentially deliver drugs directly to tumors and subsequently target cancer cells via, overexpressed receptors on the cell surface, thereby enhancing the treatment efficacy while reducing side effects. Here, we report cetuximab anchored hyaluronic acid-oleylamine and chitosan-oleic acid-based hybrid nanoparticle (HA-OA/CS-OA NPT)-loaded dissolving microneedles (MN) for targeted delivery of cabazitaxel (CBT) in localized breast cancer tumor. The HA-OA/CS-OA NPT was characterized for their size, surface charge, morphology, physicochemical characteristics, drug release behavior, and in vitro anti-cancer efficacy. The HA-OA/CS-OA NPT were of ~125 nm size, showed enhanced cytotoxicity and cellular uptake, and elicited a superior apoptotic response against MDA-MB-231 cells. Subsequently, the morphology and physicochemical characteristics of HA-OA/CS-OA NPT-loaded MN were also evaluated. The fabricated microneedles were of ~550 µm height and showed loading of nanoparticles equivalent to ~250 µg of CBT. The ex vivo skin permeation study revealed fast dissolution of microneedles upon hydration, while the drug permeation across the skin exhibited ~4-fold improvement in comparison to free drug-loaded MN. In vivo studies performed on DMBA-induced breast cancer in female SD rats showed a marked reduction in tumor volume after administration of drug and nanoparticle-loaded microneedles in comparison to intravenous administration of free drug. However, the HA-OA/CS-OA NPT-MN showed the highest tumor reduction and survival rate, with the lowest body weight reduction in comparison to other treatment groups, indicating its superior efficacy and low systemic toxicity. Overall, the dissolving microneedle-mediated delivery of targeted nanoparticles loaded with chemotherapeutics offers a superior alternative to conventional intravenous chemotherapy.

11.
Cureus ; 16(2): e54983, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38550405

RESUMO

Lymphangioma are benign, slow-growing and rare lymphatic tumors, which may emerge at any location in the body with ovary being a very rare location. Axillary region and neck are the most common sites, while retroperitoneum and mesentery account for <1%. We present a case of a young female of 33 years who had symptomatic pelvic mass and was presented with a complaint of lower abdominal pain of six-month duration and weight loss. Investigation revealed an oval-shaped complex cystic density lesion in the right adnexal region, which was likely neoplastic. Elective laparotomy with right ovarian cystectomy was performed. Histopathological examination revealed ovarian lymphangioma.

12.
Artigo em Inglês | MEDLINE | ID: mdl-38551055

RESUMO

Point of Care Diagnostics (POCD) is quintessential in hospitals and the healthcare sector as the secants uplift the quality of medical care and the life of a patient by facilitating quick identification of the underlying pathological condition. Nanotechnology can provide opportunities and has potential in the development of new-age sensing/diagnostic tools. Owing to extraordinary features (e.g., higher density, effective catalysis, good conduction, biocompatibility, inertness, and greater surface-to-volume ratio), gold nanoparticles (AuNPs) are frequently employed in POCT (Point-of-Care-Testing). Gold nanoparticles-based colorimetric methods are widely used in the rapid, sensitive, and selective detection of analytes/target molecules. AuNPs description is critical for their possible utility in prophylaxis, diagnostics, and treatment of an ailment. AuNPs interact with organic/inorganic target molecules to generate colorimetric shift that enables the accurate, precise, and subtle recognition of biologicals (e.g., microorganisms, cellular components, and proteins) and metal ions. This review focused on the need for AuNPs-based colorimetric application in prophylaxis, diagnostics, and treatment in healthcare and reviewed the future outlook of these AuNPs for biological applications. Different synthesis methods of AuNPs, their morphology, and characterization, including their surface functionalization, will be discussed in detail. AuNPs are very much preferable nanomaterials owing to exclusive optical, electrical, and photothermal features. AuNPs-based colorimetric biosensors are simple and possess great utility, yet these offer a robust technique to enable visual, quantitative analysis.

13.
Chemosphere ; 353: 141566, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38428536

RESUMO

For environmental sustainability and to achieve sustainable development goals (SDGs), drinking water treatment must be done at a reasonable cost with minimal environmental impact. Therefore, treating contaminated drinking water requires materials and approaches that are inexpensive, produced locally, and effortlessly. Hence, locally available materials and their derivatives, such as biochar (BC) and activated carbon (AC) were investigated thoroughly. Several researchers and their findings show that the application of locally accessible materials and their derivatives are capable of the adsorptive removal of organic and inorganic contaminants from drinking water. The application of locally available materials such as lignocellulosic materials/waste and its thermo-chemically derived products, including BC and AC were found effective in the treatment of contaminated drinking water. Thus, this review aims to thoroughly examine the latest developments in the use of locally accessible feedstocks for tailoring BC and AC, as well as their features and applications in the treatment of drinking water. We attempted to explain facts related to the potential mechanisms of BC and AC, such as complexation, co-precipitation, electrostatic interaction, and ion exchange to treat water, thereby achieving a risk-free remediation approach to polluted water. Additionally, this research offers guidance on creating efficient household treatment units based on the health risks associated with customized adsorbents and cost-benefit analyses. Lastly, this review work discusses the current obstacles for using locally accessible materials and their thermo-chemically produced by-products to purify drinking water, as well as the necessity for technological interventions.


Assuntos
Água Potável , Poluentes Químicos da Água , Purificação da Água , Carvão Vegetal , Poluentes Químicos da Água/análise , Adsorção
14.
Cureus ; 16(2): e53373, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38435145

RESUMO

Introduction Triple-negative breast cancer (TNBC) is a new concept and an important area of investigation. In Western country's literature, different studies reported on TNBC and all indicated the poor prognostic aspect of this molecular subtype over other types of breast cancer. However, there is a scarcity of comprehensive data from India. Hence, the present study was carried out to look at the epidemiological and clinical characteristics of TNBC in the Indian population. Methods The present study was performed between January 2020 and June 2021 at a tertiary care hospital in Eastern India. A total of 150 patients with TNBC were enrolled in the study. The epidemiological and clinical features of enrolled patients were collected and reviewed. Results The median age of patients at TNBC presentation was 45.53 years (24 to 74 years). The median tumor size was reported to be 5.32 cm. Of 150 patients, 94(62.67%) showed enlarged lymph nodes and 56 (37.33%) patients had no lymph node enlargement. In the present study, 85 (56.67%) patients were in the pre/perimenopausal stage at presentation, whereas 65 (43.33%) patients were in the postmenopausal stage. Upon evaluating the spread of TNBC, it was observed that a maximum of patients 60 (40%) were at the T4 stage and 56 (37.33%) at the N0 condition. The clinical staging of TNBC reported a maximum of 74 (49.33%) patients at the IIA, and IIB stages followed by 53 (35.33%) patients at the IIIA, IIIB, and IIIC stages and a minimum of 11 (7.33%) patients at stage IV. Only five (3.33%) patients were reported with a family history of breast cancer. Of all patients, 126 (84%) had detected early breast cancer thereby applicable for surgery at the time of presentation, whereas 71 (47.33%) patients were eligible for radiation therapy and 138 (92%) patients received chemotherapy. A total of 112 (74.67%) patients were found alive after 24 months of follow-up, 22 (4.67%) patients were observed with remission, and 11 (7.33%) patients died due to TNBC progression. During the course of follow-up, five (3.33%) patients were lost in the study.  Conclusion TNBC is an aggressive malignancy that has a high risk of systemic relapses in the first two years after diagnosis. For more mature evidence on TNBC, longer follow-up of patients is necessary.

15.
Comput Biol Chem ; 110: 108032, 2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38437779

RESUMO

Bioactive cobalt (II) macrocyclic complexes [Co(N4O4ML1)Cl2]-[Co(N4O4ML3)Cl2] have been synthesized by using the macrocyclic ligands [N4O4ML1], [N4O4ML2], and [N4O4ML3] that have an N4O4 core. These three macrocyclic ligands were all isolated in pure form, together with their complexes. Microanalytical investigations, FT-IR NMR, Mass, magnetic moments, electronic, PXRD, TGA, and EPR spectrum studies were used to analyse their structures. For these complexes, an octahedral geometry is proposed for the metal ion. By using molecular weights and conductivity measurements the monomeric and non-electrolytic nature has been confirmed. The Coats-Redfern and FWO methods are used to determine the thermodynamic characteristics of the ligands and their Co(II) complexes. The molecular modelling using the DFT technique displays the bond angle, bond lengths and quantum chemical properties. To determine their ability to prevent the growth of harmful fungus and bacteria, the ligands [N4O4ML1]- [N4O4ML3] and their complexes were tested in vitro against A. Niger, C. albicans and B. subtilis, S. aureus, E. coli and S. typhi fungal and bacterial organisms, respectively. By using DPPH free radical scavenger assays, the in vitro antioxidant capabilities of each compound were evaluated. The [Co(N4O4ML3)Cl2] antioxidative capabilities revealed significant radical scavenging power. The MTT assay was used to assess the toxicity of all the synthesised compounds under inquiry on MCF-7, HeLa, and A549 cancer cells. The findings revealed that the ligand and the compounds gave outstanding IC50 values in the range of 9.07-36.25 (uM) at a concentration of 25 ppm. Among all the substances evaluated, [Co(N4O4ML3)Cl2] complex was discovered to be the most active and least cytotoxic. Additionally, docking investigations of the produced compounds were carried out in order to validate the biological outcomes.

16.
Curr Microbiol ; 81(5): 118, 2024 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-38492019

RESUMO

Synthesizing nanoparticles through a green synthesis approach is common nowadays. Cyanobacteria have attained great importance in the field of biosynthesis of nanoparticles as there is no use of toxic chemicals as reducing or capping agents for the synthesis of metal oxide nanoparticles. Micronutrient-based nano-formulations have become a topic of great interest in recent times due to their various advantageous properties and applications in agriculture. The current study aims to exploit the potential cyanobacterial strains isolated from different locations such as freshwater and soil ecosystems. The potential cyanobacterial isolates were screened based on their multiple plant growth promoting (PGP) attributes such as Indol acetic acid (IAA) production, siderophores, and phosphate solubilization. After the screening of cyanobacteria based on multiple PGP activities, the cyanobacterial strain was identified at the species level as Pseudanabaena foetida RJ1, based on microscopy and molecular characterization using 16S rRNA gene sequencing. The cyanobacterial biomass extract and cell-free extracts are utilized for the synthesis of CuO micronutrient Nanoparticles (NPs). The cyanobacterial strain Pseudanabaena foetida RJ1 possesses plant growth-promoting (PGP) attributes that provide reduction and capping for CuO NPs. The synthesized NPs were characterized and subjected to make a nano-formulation, utilizing the cyanobacteria-mediated CuO NPs along with low-cost zeolite as an adsorbent. The application of cyanobacterial biomass extract and cell-free extract provided an excellent comparative aspect in terms of micronutrient NP synthesis. The NPs in the form of formulations were applied to germinated paddy seeds (Pusa Basmati -1509) with varying concentrations (5, 10, 15 mg/l). Effects of cyanobacteria based CuO NPs on hydroponically grown paddy crops were analyzed. The application of nano-formulations has shown a significant increase in plant growth promotion in rice plants under hydroponics conditions. There is no such type of comparative investigation reported earlier, and NPs of micronutrients can be utilized as a new economic nanofertilizer and can be applied to plants for their growth promotion.


Assuntos
Cianobactérias , Nanopartículas Metálicas , Nanopartículas , Oryza , Cobre/farmacologia , Hidroponia , RNA Ribossômico 16S/genética , Ecossistema , Nanopartículas Metálicas/química , Micronutrientes , Extratos Vegetais
17.
Nanomedicine (Lond) ; 19(7): 633-651, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38445583

RESUMO

Nanomedicine has opened up new avenues for cancer treatment by enhancing drug solubility, permeability and targeted delivery to cancer cells. Despite its numerous advantages over conventional therapies, nanomedicine may exhibit off-target drug distribution, harming nontarget regions. The increased permeation and retention effect of nanomedicine in tumor sites also has its limitations, as abnormal tumor vasculature, dense stroma structure and altered tumor microenvironment (TME) may result in limited intratumor distribution and therapeutic failure. However, TME-responsive nanomedicine has exhibited immense potential for efficient, safe and precise delivery of therapeutics utilizing stimuli specific to the TME. This review discusses the mechanistic aspects of various TME-responsive biopolymers and their application in developing various types of TME-responsive nanomedicine.


Assuntos
Nanomedicina , Neoplasias , Humanos , Microambiente Tumoral , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Sistemas de Liberação de Medicamentos
18.
J Nematol ; 56(1): 20240007, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38510971

RESUMO

Anguina tritici, the wheat seed gall nematode, causes the 'ear-cockle' or seed gall disease of wheat (Triticum sp.), leading to an extensive decline of yield (30-70%) in underdeveloped wheat cultivating countries of the world. The nematode is known to survive in anhydrobiotic conditions for up to 32 years. Here, we present the first transcriptome assembly of A. tritici, which will be a valuable resource for understanding the genes responsible for nematode survival and above-ground plant parasitism. The final 133.2 Mb assembly consists of 105606 open reading frames (including isoforms) with the following BUSCO scores against Nematoda database: 80.3% complete (16.4% single copy and 63.9% duplicated), 2.1% fragmented, and 17.6% missing.

19.
Environ Monit Assess ; 196(4): 393, 2024 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-38520559

RESUMO

Tropospheric ozone is an air pollutant at the ground level and a greenhouse gas which significantly contributes to the global warming. Strong anthropogenic emissions in and around urban environments enhance surface ozone pollution impacting the human health and vegetation adversely. However, observations are often scarce and the factors driving ozone variability remain uncertain in the developing regions of the world. In this regard, here, we conducted machine learning (ML) simulations of ozone variability and comprehensively examined the governing factors over a major urban environment (Ahmedabad) in western India. Ozone precursors (NO2, NO, CO, C5H8 and CH2O) from the CAMS (Copernicus Atmosphere Monitoring Service) reanalysis and meteorological parameters from the ERA5 (European Centre for Medium-Range Weather Forecast's (ECMWF) fifth-generation reanalysis) were included as features in the ML models. Automated ML (AutoML) fitted the deep learning model optimally and simulated the daily ozone with root mean square error (RMSE) of ~2 ppbv reproducing 84-88% of variability. The model performance achieved here is comparable to widely used ML models (RF-Random Forest and XGBoost-eXtreme Gradient Boosting). Explainability of the models is discussed through different schemes of feature importance, including SAGE (Shapley Additive Global importancE) and permutation importance. The leading features are found to be different from different feature importance schemes. We show that urban ozone could be simulated well (RMSE = 2.5 ppbv and R2 = 0.78) by considering first four leading features, from different schemes, which are consistent with ozone photochemistry. Our study underscores the need to conduct science-informed analysis of feature importance from multiple schemes to infer the roles of input variables in ozone variability. AutoML-based studies, exploiting potentials of long-term observations, can strongly complement the conventional chemistry-transport modelling and can also help in accurate simulation and forecast of urban ozone.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Ozônio , Humanos , Ozônio/análise , Poluição do Ar/análise , Monitoramento Ambiental , Poluentes Atmosféricos/análise , Aprendizado de Máquina
20.
Colloids Surf B Biointerfaces ; 237: 113865, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38520950

RESUMO

BACKGROUND: Nanocrystals can be produced as a dry powder for inhalation (DPIs) to deliver high doses of drug to the lungs, owing to their high payload and stability to the shear stress of aerosolization force. Furthermore, lipid-coated nanocrystals can be formulated to improve the drug accumulation and retention in lung. OBJECTIVE: The present work involved the fabrication of paclitaxel nanocrystals using hydrophilic marine biopolymer fucoidan as a stabilizer. Thereafter, fabricated nanocrystals (FPNC) were surface-modified with phospholipid to give lipid-coated nanocrystals (Lipo-NCs). METHODS: The nanocrystals were fabricated by antisolvent crystallization followed by the probe sonication. The lipid coating was achieved by thin film hydration followed ultrasonic dispersion technique. Prepared nanocrystals were lyophilized to obtain a dry powder of FPNC and Lipo-NCs, used later for physicochemical, microscopic, and spectroscopic characterization to confirm the successful formation of desired nanocrystals. In-vitro and in-vivo investigations were also conducted to determine the role of nanocrystal powder in pulmonary drug delivery. RESULTS: Lipo-NCs exhibited slower drug release, excellent flow properties, good aerosolization performance, higher drug distribution, and prolonged retention in the lungs compared to FPNC and pure PTX. CONCLUSION: Lipid-coated nanocrystals can be a novel formulation for the maximum localization of drugs in the lungs, thereby enhancing therapeutic effects and avoiding systemic side effects in lung cancer therapy.


Assuntos
Nanopartículas , Paclitaxel , Paclitaxel/química , Pós , Administração por Inalação , Nanopartículas/química , Lipídeos , Tamanho da Partícula
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...