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1.
Artigo em Inglês | MEDLINE | ID: mdl-39102648

RESUMO

Type III effectors (T3Es) are major determinants of Xanthomonas virulence and targets for resistance breeding. XopJ2 (syn. AvrBsT) is a highly conserved YopJ-family T3E acquired by X. perforans, the pathogen responsible for bacterial spot disease of tomato. In this study, we characterized a new variant (XopJ2b) of XopJ2, which is predicted to have a similar 3D structure as the canonical XopJ2 (XopJ2a) despite sharing only 70% sequence identity. XopJ2b carries an acetyltransferase domain and the critical residues required for its activity, and the positions of these residues are predicted to be conserved in 3D structure of the proteins. We demonstrated that XopJ2b is a functional T3E and triggers hypersensitive response when translocated into pepper cells. Like XopJ2a, XopJ2b triggers HR in Arabidopsis that is suppressed by the deacetylase, SOBER1. We found xopJ2b in genome sequences of X. euvesicatoria, X. campestris, X. citri, X. guizotiae, and X. vasicola strains, suggesting widespread horizontal transfer. In X. perforans, xopJ2b was present in strains collected in North and South America, Africa, Asia, Australia, and Europe, whereas xopJ2a had a more narrow geographic distribution. This study expands the Xanthomonas T3E repertoire, demonstrates functional conservation in T3E evolution, and further supports the importance of XopJ2 in X. perforans fitness on tomato.

2.
Front Mol Biosci ; 11: 1421030, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39184151

RESUMO

Background: Glaucoma is the leading cause of permanent blindness. Primary angle closure glaucoma (PACG) is diagnosed only after the onset of symptoms and can result in irreversible blindness despite the standard intraocular pressure (IOP) reduction therapy. The identification of potential biomarkers associated with prognosis will help improve disease management. This study aimed to identify mechanisms associated with disease progression, potential biomarkers, and therapeutic targets of PACG. Methods: The clinical data assessment of IOP, cup/disc ratio (CDR), Retinal Nerve Fiber Layer (RNFL) thickness of control, and PACG group were collected and analyzed for significant differences. The ATP levels were estimated, and targeted metabolomic analysis was performed on aqueous humor and cytokines in plasma. The pathways obtained from the metabolomics data set were compared with those obtained for data sets from the literature. Clinical parameters were correlated with cytokine levels. Targeted metabolomic analysis of cell culture supernatant from TNFα-treated N9 microglia was carried out, and overlap analysis was performed with data obtained from PACG patients. Results: Elevated IOP, CDR, ATP, cytokines, and reduced RNFL thickness were found in PACG compared to controls. Analysis of PACG and TNFα-treated N9 microglial cell culture supernatant shows activation of immuno-metabolites. The metabolic pathways of PACG, TNFα, and ATP-treated microglia from the literature show considerable overlap. Biomarker analysis identified clinical parameters, ATP, cytokines, and immuno-metabolites. Conclusion: This study shows an association between elevated levels of ATP, cytokines, immuno-metabolism, and potential microglial inflammation with disease progression, rendering these levels potential biomarkers. P2 receptors, cytokines, and IDO1/2 could be potential therapeutic targets.

3.
Oman J Ophthalmol ; 17(2): 268-270, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39132126

RESUMO

A 9-year-old child presented with a palpable swelling under the right lower lid for 3 years. On examination, the swelling was nontender, well circumscribed, and cystic on palpation. A computed tomography scan showed a well circumscribed, hyperdense lesion in the inferior orbit with no anatomic connection with the paranasal sinuses. Transcutaneous orbitotomy was performed, and the lesion was excised in toto. Histopathological examination was suggestive of a mucocele.

4.
Heliyon ; 10(13): e34132, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-39071585

RESUMO

Effective planning, management, and control of industrial plants and processes have exploded in popularity to enhance global sustainability in recent decades. In this arena, computational predictive models have significantly contributed to plant performance optimization. In this regard, this research proposes an Improvised Grey Wolf Optimizer (IGWO) aided Artificial Neural Network (ANN) predictive model (IGWO-ANN Model-1 to 4) to predict the performance (permeate flux) of desalination plants accurately. For this, the proposed models investigated experimental inputs four: salt concentration & feed flow rate, condenser & evaporator inlet temperatures of the plant. Besides, mean squared error (MSE) and the regression coefficients (R2) have been used to assess the models' accuracy. The proposed IGWO-ANN Model-4 shows strong optimization abilities and provides better R2 = 99.3 % with minimum errors (0.004) compared to existing Response Surface Methodology (RSM) (R2 = 98.5 %, error = 0.100), ANN (R2 = 98.8 %, error = 0.060), GWO-ANN (R2 = 98.8 % error = 0.008), models. The proposed models are multitasking, multilayers, and multivariable, capable of accurately analyzing the desalination plant's performance, and suitable for other industrial applications. This study yielded a promising outcome and revealed the significant pathways for the researchers to analyze the desalination plant's performance to save time, money, and energy.

5.
Org Lett ; 26(30): 6471-6476, 2024 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-39042831

RESUMO

Visible light-induced C-3 arylation of quinoxalin-2(1H)-ones with abundantly available aryl iodides with good yields via an electron-donor-acceptor (EDA)-complex formation have been accomplished. The radical scavenging, Electron paramagnetic resonance (EPR), UV-visible experiments, density functional theory (DFT), and quantum yield studies revealed that the reaction went through a radical pathway via a single electron transfer (SET) process. Furthermore, the protocol could also be applied to the synthesis of biologically active molecules, illustrating the practicality of the present protocol.

6.
Artigo em Inglês | MEDLINE | ID: mdl-38949619

RESUMO

The emergence of plant pathogens is often associated with waves of unique evolutionary and epidemiological events. Xanthomonas hortorum pv. gardneri is one of the major pathogens causing bacterial spot disease of tomatoes. After its first report in the 1950s, there were no formal reports on this pathogen until the 1990s, despite active global research on the pathogens that cause tomato and pepper bacterial spot disease. Given the recently documented global distribution of X. hortorum pv. gardneri, our objective was to examine genomic diversification associated with its emergence. We sequenced the genomes of X. hortorum pv. gardneri strains collected in eight countries to examine global population structure and pathways of emergence using phylodynamic analysis. We found that strains isolated post-1990 group by region of collection and show minimal impact of recombination on genetic variation. A period of rapid geographic expansion in X. hortorum pv. gardneri is associated with acquisition of a large plasmid conferring copper tolerance by horizontal transfer and coincides with the burgeoning hybrid tomato seed industry through the 1980s. The ancestry of X. hortorum pv. gardneri is consistent with introduction to hybrid tomato seed production and dissemination during the rapid increase in trade of hybrid seeds.

7.
BMC Genomics ; 25(1): 711, 2024 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-39044136

RESUMO

BACKGROUND: Bacterial spot of pepper (BSP), caused by four different Xanthomonas species, primarily X. euvesicatoria (Xe), poses a significant challenge in pepper cultivation. Host resistance is considered the most important approach for BSP control, offering long-term protection and sustainability. While breeding for resistance to BSP for many years focused on dominant R genes, introgression of recessive resistance has been a more recent focus of breeding programs. The molecular interactions underlying recessive resistance remain poorly understood. RESULTS: In this study, transcriptomic analyses were performed to elucidate defense responses triggered by Xe race P6 infection by two distinct pepper lines: the Xe-resistant line ECW50R containing bs5, a recessive resistance gene that confers resistance to all pepper Xe races, and the Xe-susceptible line ECW. The results revealed a total of 3357 upregulated and 4091 downregulated genes at 0, 1, 2, and 4 days post-inoculation (dpi), with the highest number of differentially expressed genes (DEGs) observed at 2 dpi. Pathway analysis highlighted DEGs in key pathways such as plant-pathogen interaction, MAPK signaling pathway, plant hormone signal transduction, and photosynthesis - antenna proteins, along with cysteine and methionine metabolism. Notably, upregulation of genes associated with PAMP-Triggered Immunity (PTI) was observed, including components like FLS2, Ca-dependent pathways, Rboh, and reactive oxygen species (ROS) generation. In support of these results, infiltration of ECW50R leaves with bacterial suspension of Xe led to observable hydrogen peroxide accumulation without a rapid increase in electrolyte leakage, suggestive of the absence of Effector-Triggered Immunity (ETI). Furthermore, the study confirmed that bs5 does not disrupt the effector delivery system, as evidenced by incompatible interactions between avirulence genes and their corresponding dominant resistant genes in the bs5 background. CONCLUSION: Overall, these findings provide insights into the molecular mechanisms underlying bs5-mediated resistance in pepper against Xe and suggest a robust defense mechanism in ECW50R, primarily mediated through PTI. Given that bs5 provides early strong response for resistance, combining this resistance with other dominant resistance genes will enhance the durability of resistance to BSP.


Assuntos
Capsicum , Resistência à Doença , Perfilação da Expressão Gênica , Doenças das Plantas , Xanthomonas , Capsicum/genética , Capsicum/microbiologia , Capsicum/imunologia , Resistência à Doença/genética , Doenças das Plantas/microbiologia , Doenças das Plantas/genética , Regulação da Expressão Gênica de Plantas , Transcriptoma
8.
Genetics ; 227(3)2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38733622

RESUMO

Genetically encoded optical indicators and actuators of neural activity allow for all-optical investigations of signaling in the nervous system. But commonly used indicators, actuators, and expression strategies are poorly suited for systematic measurements of signal propagation at brain scale and cellular resolution. Large-scale measurements of the brain require indicators and actuators with compatible excitation spectra to avoid optical crosstalk. They must be highly expressed in every neuron but at the same time avoid lethality and permit the animal to reach adulthood. Their expression must also be compatible with additional fluorescent labels to locate and identify neurons, such as those in the NeuroPAL cell identification system. We present TWISP, a transgenic worm for interrogating signal propagation, that addresses these needs and enables optical measurements of evoked calcium activity at brain scale and cellular resolution in the nervous system of the nematode Caenorhabditis elegans. In every neuron we express a nonconventional optical actuator, the gustatory receptor homolog GUR-3 + PRDX-2, under the control of a drug-inducible system QF + hGR, and a calcium indicator GCAMP6s, in a background with additional fluorophores from the NeuroPAL cell ID system. We show that this combination, but not others tested, avoids optical crosstalk, creates strong expression in the adult, and generates stable transgenic lines for systematic measurements of signal propagation in the worm brain.


Assuntos
Animais Geneticamente Modificados , Caenorhabditis elegans , Neurônios , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Neurônios/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Cálcio/metabolismo , Transdução de Sinais , Sinalização do Cálcio , Encéfalo/metabolismo
9.
J Cell Signal ; 5(2): 51-56, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38726221

RESUMO

In the quest for improving the clinical outcome of patients with metastatic genitourinary cancers, including metastatic renal cell carcinoma (mRCC), the emphasis often is on finding new targeted therapies. However, two studies by Jordan et al. (Oncogenesis 2020) and Wang et al. (Cancer Cell Int 2022) demonstrate the feasibility of improving the efficacy of a modestly effective drug Sorafenib against mRCC by attacking a mechanism hijacked by RCC cells for inactivating Sorafenib. The studies also identified hyaluronic acid synthase -3 (HAS3) as a bonafide target of Sorafenib in RCC cells. The studies demonstrate that an over-the-counter drug Hymecromone (4-methylumbelliferone) blocks inactivation of Sorafenib in RCC cells and improves its efficacy against mRCC through the inhibition of HAS3 expression and HA signaling. In the broader context, improving the efficacy of "old and failed drugs" that have favorable safety profiles should increase the availability of effective treatments for patients with advanced cancers.

10.
Environ Monit Assess ; 196(5): 491, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38691183

RESUMO

This study explores the dual applications of a greenly synthesized ZnO@CTAB nanocomposite for the efficient remediation of Rhodamine B (RhB) and lead (Pb). The synthesis method involves a sustainable approach, emphasizing environmentally friendly practices. FT-IR, XRD, FESEM, zeta potential, and particle size analyzer (PSA), BET, and UV-VIS were used to physically characterize the zinc oxide and CTAB nanocomposite (ZnO@CTAB). The size and crystalline index of ZnO@CTAB are 77.941 nm and 63.56% respectively. The Zeta potential of ZnO@CTAB is about - 22.4 mV. The pore diameter of the ZnO@CTAB was 3.216 nm, and its total surface area was 97.42 m2/g. The mechanism of adsorption was investigated through pHZPC measurements. The nanocomposite's adsorption performance was systematically investigated through batch adsorption experiments. At pH 2, adsorbent dose of 0.025 g, and temperature 50 °C, ZnO@CTAB removed the most RhB, while at pH 6, adsorbent dose of 0.11 g, and temperature 60 °C, ZnO@CTAB removed the most Pb. With an adsorption efficiency of 214.59 mg/g and 128.86 mg/g for RhB and Pb, the Langmuir isotherm model outperforms the Freundlich isotherm model in terms of adsorption. The pseudo-2nd-order model with an R2 of 0.99 for both RhB and Pb offers a more convincing explanation of adsorption than the pseudo-1st-order model. The results demonstrated rapid adsorption kinetics and high adsorption capacities for RhB and Pb. Furthermore, there was minimal deterioration and a high reusability of ZnO@CTAB till 4 cycles were observed.


Assuntos
Chumbo , Nanocompostos , Rodaminas , Poluentes Químicos da Água , Óxido de Zinco , Chumbo/química , Óxido de Zinco/química , Rodaminas/química , Nanocompostos/química , Poluentes Químicos da Água/química , Adsorção , Cetrimônio/química , Recuperação e Remediação Ambiental/métodos , Química Verde , Nanoestruturas/química
11.
Phytopathology ; 114(7): 1433-1446, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38648116

RESUMO

In this review, we highlight studies in which whole-genome sequencing, comparative genomics, and population genomics have provided unprecedented insights into past and ongoing pathogen evolution. These include new understandings of the adaptive evolution of secretion systems and their effectors. We focus on Xanthomonas pathosystems that have seen intensive study and improved our understanding of pathogen emergence and evolution, particularly in the context of host specialization: citrus canker, bacterial blight of rice, and bacterial spot of tomato and pepper. Across pathosystems, pathogens appear to follow a pattern of bursts of evolution and diversification that impact host adaptation. There remains a need for studies on the mechanisms of host range evolution and genetic exchange among closely related but differentially host-specialized species and to start moving beyond the study of specific strain and host cultivar pairwise interactions to thinking about these pathosystems in a community context.


Assuntos
Doenças das Plantas , Xanthomonas , Xanthomonas/genética , Xanthomonas/patogenicidade , Xanthomonas/fisiologia , Doenças das Plantas/microbiologia , Evolução Biológica , Interações Hospedeiro-Patógeno , Especificidade de Hospedeiro , Genoma Bacteriano/genética , Oryza/microbiologia , Citrus/microbiologia , Capsicum/microbiologia , Genômica , Evolução Molecular
12.
Curr Cardiol Rev ; 20(4): 15-38, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38685783

RESUMO

BACKGROUND: Myocardial infarction (MI), also referred to as a "heart attack," is brought on by a partial or total interruption of blood supply to the myocardium. Myocardial infarction can be "silent," go undiagnosed, or it can be a catastrophic occurrence that results in hemodynamic decline and untimely death. In recent years, herbal remedies for MI have become effective, secure, and readily accessible. OBJECTIVE: The purpose of this review was to examine the medicinal plants and phytochemicals that have been used to treat MI in order to assess the potential contribution of natural substances to the development of herbal MI treatments. METHODOLOGY: A literature search was employed to find information utilizing electronic databases, such as Web of Science, Google Scholar, PubMed, Sci Finder, Reaxys, and Cochrane. RESULTS: The identification of 140 plants from 12 families led to the abstraction of data on the plant families, parts of the plant employed, chemical contents, extracts, model used, and dose. CONCLUSION: The majority of the MI plants, according to the data, belonged to the Fabaceae (11%) and Asteraceae (9%) families, and the most prevalent natural components in plants with MI were flavonoids (43%), glucosides (25%), alkaloids (23%), phenolic acid (19%), saponins (15%), and tannins (12%).


Assuntos
Infarto do Miocárdio , Fitoterapia , Extratos Vegetais , Plantas Medicinais , Infarto do Miocárdio/tratamento farmacológico , Humanos , Plantas Medicinais/química , Fitoterapia/métodos , Extratos Vegetais/uso terapêutico , Compostos Fitoquímicos/uso terapêutico , Compostos Fitoquímicos/análise
13.
bioRxiv ; 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38585821

RESUMO

An animal's current behavior influences its response to sensory stimuli, but the molecular and circuit-level mechanisms of this context-dependent decision-making is not well understood. In the nematode C. elegans, inhibitory feedback from turning associated neurons alter downstream mechanosensory processing to gate the animal's response to stimuli depending on whether the animal is turning or moving forward [1-3]. Until now, the specific neurons and receptors that mediate this inhibitory feedback were not known. We use genetic manipulations, single-cell rescue experiments and high-throughput closed-loop optogenetic perturbations during behavior to reveal the specific neuron and receptor responsible for receiving inhibition and altering sensorimotor processing. An inhibitory acetylcholine gated chloride channel comprised of lgc-47 and acc-1 expressed in neuron RIM receives inhibitory signals from turning neurons and performs the gating that disrupts the worm's mechanosensory evoked reversal response.

14.
Plant Physiol ; 195(3): 2213-2233, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38466200

RESUMO

Rho of Plant (ROP) GTPases function as molecular switches that control signaling processes essential for growth, development, and defense. However, their role in specialized metabolism is poorly understood. Previously, we demonstrated that inhibition of protein geranylgeranyl transferase (PGGT-I) negatively impacts the biosynthesis of monoterpene indole alkaloids (MIA) in Madagascar periwinkle (Catharanthus roseus), indicating the involvement of prenylated proteins in signaling. Here, we show through biochemical, molecular, and in planta approaches that specific geranylgeranylated ROPs modulate C. roseus MIA biosynthesis. Among the six C. roseus ROP GTPases (CrROPs), only CrROP3 and CrROP5, having a C-terminal CSIL motif, were specifically prenylated by PGGT-I. Additionally, their transcripts showed higher expression in most parts than other CrROPs. Protein-protein interaction studies revealed that CrROP3 and CrROP5, but not ΔCrROP3, ΔCrROP5, and CrROP2 lacking the CSIL motif, interacted with CrPGGT-I. Further, CrROP3 and CrROP5 exhibited nuclear localization, whereas CrROP2 was localized to the plasma membrane. In planta functional studies revealed that silencing of CrROP3 and CrROP5 negatively affected MIA biosynthesis, while their overexpression upregulated MIA formation. In contrast, silencing and overexpression of CrROP2 had no effect on MIA biosynthesis. Moreover, overexpression of ΔCrROP3 and ΔCrROP5 mutants devoid of sequence coding for the CSIL motif failed to enhance MIA biosynthesis. These results implicate that CrROP3 and CrROP5 have a positive regulatory role on MIA biosynthesis and thus shed light on how geranylgeranylated ROP GTPases mediate the modulation of specialized metabolism in C. roseus.


Assuntos
Catharanthus , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas , Catharanthus/genética , Catharanthus/metabolismo , Catharanthus/enzimologia , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Prenilação de Proteína , Motivos de Aminoácidos , Alcaloides/metabolismo , Alcaloides/biossíntese
15.
J Org Chem ; 89(8): 5229-5238, 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38551089

RESUMO

Mechanochemistry refers to the initiation of chemical reactions via mechanical forces such as milling, grinding, or shearing to achieve the chemical transformations. As a manifestation of mechanocatalysis, herein, an oxidant-free and solvent-free approach for the synthesis of quinazolinones (23 derivatives) and benzothiazoles (23 derivatives) has been developed through stainless-steel-driven decarboxylative acyl radical generation from α-keto acids. A library of 2-arylquinazolinones and 2-arylbenzothiazoles has been prepared in moderate to good yields at room temperature. Moreover, control experiments and XPS studies supported the reduction (by zerovalent iron) of molecular oxygen through the moderate abrasion of balls, which promoted the generation of a superoxide radical anion via a SET process.

16.
iScience ; 27(3): 109191, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38433928

RESUMO

The paucity of preclinical models that recapitulate COVID-19 pathology without requiring SARS-COV-2 adaptation and humanized/transgenic mice limits research into new therapeutics against the frequently emerging variants-of-concern. We developed virus-free models by C57BL/6 mice receiving oropharyngeal instillations of a SARS-COV-2 ribo-oligonucleotide common in all variants or specific to Delta/Omicron variants, concurrently with low-dose bleomycin. Mice developed COVID-19-like lung pathologies including ground-glass opacities, interstitial fibrosis, congested alveoli, and became moribund. Lung tissues from these mice and bronchoalveolar lavage and lung tissues from patients with COVID-19 showed elevated levels of hyaluronic acid (HA), HA-family members, an inflammatory signature, and immune cell infiltration. 4-methylumbelliferone (4-MU), an oral drug for biliary-spasm treatment, inhibits HA-synthesis. At the human equivalent dose, 4-MU prevented/inhibited COVID-19-like pathologies and long-term morbidity; 4-MU and metabolites accumulated in mice lungs. Therefore, these versatile SARS-COV-2 ribo-oligonucleotide oropharyngeal models recapitulate COVID-19 pathology, with HA as its critical mediator and 4-MU as a potential therapeutic for COVID-19.

17.
Chem Commun (Camb) ; 60(12): 1579-1582, 2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38224119

RESUMO

A new Ru(II) arene chlorido organometallic complex [(η6-p-cymene)(L)RuCl]PF6 (named as pCYRuL) using 2-bis(quinolin-2-ylmethylene) hydrazine (L) was developed that exhibits potent anticancer activity against castration-resistant prostate cancer (CRPC) (IC50 = 0.71 µM), and it is 45 times more effective than the standard drug cisplatin (IC50 = 31.3 µM) in a castration-resistant human prostatic adenocarcinoma cell line (PC-3) but non-toxic in normal human kidney cells (HK2) as well as normal breast cells (MCF10A) and found that pCYRuL exerted anticancer activity via apoptosis induction and cell cycle arrest in the G2/M phase of PC-3 cells.


Assuntos
Antineoplásicos , Complexos de Coordenação , Neoplasias de Próstata Resistentes à Castração , Quinolinas , Rutênio , Masculino , Humanos , Antineoplásicos/farmacologia , Complexos de Coordenação/farmacologia , Rutênio/farmacologia , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Proliferação de Células , Quinolinas/farmacologia , Linhagem Celular Tumoral
18.
Sensors (Basel) ; 24(2)2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38257637

RESUMO

Shape memory alloys (SMAs) have become the most common choice for the development of mini- and micro-type soft bio-inspired robots due to their high power-to-weight ratio, ability to be installed and operated in limited space, silent and vibration-free operation, biocompatibility, and corrosion resistance properties. Moreover, SMA spring-type actuators are used for developing different continuum robots, exhibiting high degrees of freedom and flexibility. Spring- or any elastic-material-based antagonistic or biasing force is mostly preferred among all other biasing techniques to generate periodic oscillation of SMA actuator-based robotic body parts. In this model-based study, SMA-based spring-type actuators were used to develop a carangiform-type robotic fishtail. Fin size optimization for the maximization of forward thrust was performed for the developed system by varying different parameters, such as caudal fin size, current through actuators, pulse-width modulation signal (PWM), and operating depth. A caudal fin with a mixed fin pattern between the Lunate and Fork "Lunafork" and a fin area of approximately 5000 mm2 was found to be the most effective for the developed system. The maximum forward thrust developed by this fin was recorded as 40 gmf at an operation depth of 12.5 cm in a body of still water.

19.
ACS Phys Chem Au ; 4(1): 57-66, 2024 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-38283784

RESUMO

Aß1-40 peptide and Aß1-42 peptide are the building units of beta-amyloid plaques present in Alzheimer's disease (AD)-affected brain. The binding affinity of various divalent metal ions such as Cu and Zn present in AD-affected brain with different amino acids available in Aß-peptide became the focus to explore their role in soluble neurotoxic oligomer formation. Cu2+ metal ions are known to enhance the neurotoxicity of the Aß1-42 peptide by catalyzing the formation of soluble neurotoxic oligomers. The competitive preference of both Cu2+ and Zn2+ simultaneously to interact with the Aß-peptide is unknown. The divalent Cu and Zn ions were inserted in explicit aqueous Aß1-42 peptide configurations to get insights into the binding competence of these metal ions with peptides using classical molecular dynamics (MD) simulations. The metal-ion interactions reveal that competitive binding preferences of various peptide sites become metal-ion-specific and differ significantly. For Cu2+, interactions are found to be more significant with respect to those of Asp-7, His-6, Glu-11, and His-14. Asp-1, Glu-3, Asp-7, His-6, Glu-11, and His-13 amino acid residues show higher affinity toward Zn2+ ions. MD simulations show notable variation in the solvent-accessible surface area in the hydrophobic region of the peptide. Infinitesimal mobility was obtained for Zn2+ compared to Cu2+ in an aqueous solution and Cu2+ diffusivity deviated significantly at different time scales, proving its labile features in aqueous Aß1-42 peptides.

20.
Curr Biol ; 34(1): R14-R15, 2024 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-38194919

RESUMO

Stereotyped oscillations in population neural activity recordings from immobilized Caenorhabditis elegans have garnered interest for their striking low dimensionality and their evocative state-space trajectories or manifolds. Previously these oscillations have been interpreted as intrinsically driven global motor commands. Here we test whether these oscillations are intrinsic. We show that similar oscillations are evoked by high-intensity blue light commonly used for calcium imaging. Oscillations are reduced or absent and have a lower frequency when a longer imaging wavelength is used. Under the original blue light illumination, oscillations are reduced or have a lower frequency in animals that lack GUR-3, an endogenous light- and hydrogen-peroxide-sensitive gustatory receptor. Additional experiments with hydrogen peroxide are consistent with GUR-3's involvement. We therefore propose that blue light evokes global oscillations in part through the creation of reactive oxygen species that activate the hydrogen-peroxide-sensing receptor GUR-3.


Assuntos
Encéfalo , Caenorhabditis elegans , Animais , Luz Azul , Peróxido de Hidrogênio , Peróxidos , Hidrogênio
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