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1.
Rev Sci Instrum ; 95(5)2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38717655

RESUMO

We report a Bidirectional Electrode Control Arm Assembly (BECAA) for precisely manipulating dust clouds levitated above the powered electrode in RF plasmas. The reported techniques allow the creation of perfectly 2D dust layers by eliminating off-plane particles by moving the electrode from outside the plasma chamber without altering the plasma conditions. The tilting and moving of electrodes using BECAA also allows the precise and repeatable elimination of dust particles one by one to achieve any desired number of grains N without trial and error. Simultaneously acquired top and side view images of dust clusters show that they are perfectly planar or 2D. A demonstration of clusters with N = 1-28 without changing the plasma conditions is presented to show the utility of BECAA for complex plasma and statistical physics experimental design. Demonstration videos and 3D printable part files are available for easy reproduction and adaptation of this new method to repeatably produce 2D clusters in existing RF plasma chambers.

2.
Beilstein J Org Chem ; 20: 1020-1028, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38711591

RESUMO

Diaryliodonium(III) salts are versatile reagents that exhibit a range of reactions, both in the presence and absence of metal catalysts. In this study, we developed efficient synthetic methods for the preparation of aryl(TMP)iodonium(III) carboxylates, by reaction of (diacetoxyiodo)arenes or iodosoarenes with 1,3,5-trimethoxybenzene in the presence of a diverse range of organocarboxylic acids. These reactions were conducted under mild conditions using the trimethoxyphenyl (TMP) group as an auxiliary, without the need for additives, excess reagents, or counterion exchange in further steps. These protocols are compatible with a wide range of substituents on (hetero)aryl iodine(III) compounds, including electron-rich, electron-poor, sterically congested, and acid-labile groups, as well as a broad range of aliphatic and aromatic carboxylic acids for the synthesis of diverse aryl(TMP)iodonium(III) carboxylates in high yields. This method allows for the hybridization of complex bioactive and fluorescent-labeled carboxylic acids with diaryliodonium(III) salts.

3.
Phys Chem Chem Phys ; 26(17): 13287-13299, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38639091

RESUMO

Copper iodide, an environmentally friendly material abundant in nature, holds great significance for room temperature thermoelectric (TE) applications owing to its high Seebeck coefficient and optical transparency. However, to fully unlock its thermoelectric potential and match the performance of conventional TE materials, there is a need to further enhance its electrical conductivity. In this study, we have successfully synthesized nano-crystalline powders of both undoped and aluminium-doped CuI at room temperature using the chemical precipitation method in an ethanol medium. The concentration of aluminium dopant has been optimized to maximize TE performance. At 400 K, the highest TE power factor and figure of merit achieved are 79 µW m-1 K-2 and 0.08, respectively, for CuI doped with 0.1 mol% Al. This enhancement in TE properties can be attributed to the increased carrier density resulting from aluminium doping. The impact of aluminium doping on the temperature-dependent thermal conductivity has been investigated, and the findings are explained by the decay mechanism of optical phonons, supported by the anharmonic phonon coupling theory. Our work delves into the evolution of structural, thermal, optical, and TE properties of CuI upon aluminium (Al) doping. The results provide valuable insights into the future application of CuI in transparent thermoelectric and optoelectronic fields.

4.
Shock ; 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38662580

RESUMO

ABSTRACT: Sepsis is the most frequent risk factor for acute kidney injury (AKI) in critically ill infants. Sepsis-induced dysregulation of kidney microcirculation in newborns is unresolved. The objective of this study was to use the translational swine model to evaluate changes in kidney function during the early phase of sepsis in newborns and the impact of fluid plus norepinephrine (NE) resuscitation. Newborn pigs (3-7-day-old) were allocated randomly to three groups: 1) Sham, 2) Sepsis (cecal ligation and puncture; CLP) without subsequent resuscitation, and 3) Sepsis with Lactated Ringer plus NE resuscitation. All animals underwent standard anesthesia and mechanical ventilation. Cardiac output (COP) and glomerular filtration rate (GFR) were measured non-invasively. Mean arterial pressure (MAP), total renal blood flow (RBF), cortical perfusion (coPf), medullary perfusion (mePf), and medullary tissue oxygen tension (mtPO2) were determined for 12 h. CLP decreased MAP and COP by more than 50%, with a proportional increase in renal vascular resistance (RVR) and a 60-80% reduction in RBF, coPf, mePf, and mtPO2 compared to sham. CLP also decreased GFR by ~79% and increased AKI biomarkers. Isolated foci of tubular necrosis were observed in the septic piglets. Except for mtPO2, changes in all these parameters were ameliorated in resuscitated piglets. Resuscitation also attenuated sepsis-induced increases in the levels of plasma C-reactive protein, proinflammatory cytokines, lactate dehydrogenase, alanine transaminase, aspartate aminotransferase, and renal NLRP3 inflammasome. These data suggest that newborn pigs subjected to CLP develop hypodynamic septic AKI. Early implementation of resuscitation lessens the degree of inflammation, AKI, and liver injury.

5.
Inorg Chem ; 63(16): 7218-7232, 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38593245

RESUMO

Designing highly active and robust earth abundant trifunctional electrocatalysts for energy storage and conversion applications remain an enormous challenge. Herein, we report a trifunctional electrocatalyst (CrCo/CoN4@CNT-5), synthesized at low calcination temperature (550 °C), which consists of Co-N4 single atom and CrCo alloy nanoparticles and exhibits outstanding electrocatalytic performance for the hydrogen evolution reaction, oxygen evolution reaction, and oxygen reduction reaction. The catalyst is able to deliver a current density of 10 mA cm-2 in an alkaline electrolytic cell at a very low cell voltage of ∼1.60 V. When the catalyst is equipped in a liquid rechargeable Zn-air battery, it endowed a high open-circuit voltage with excellent cycling durability and outperformed the commercial Pt/C+IrO2 catalytic system. Furthermore, the Zn-air battery powered self-driven water splitting system is displayed using CrCo/CoN4@CNT-5 as sole trifunctional catalyst, delivering a high H2 evolution rate of 168 µmol h-1. Theoretical calculations reveal synergistic interaction between Co-N4 active sites and CrCo nanoparticles, favoring the Gibbs free energy for H2 evolution. The presence of Cr not only enhances the H2O adsorption and dissociation but also tunes the electronic property of CrCo nanoparticles to provide optimized hydrogen binding capacity to Co-N4 sites, thus giving rise to accelerated H2 evolution kinetics. This work highlights the importance of the presence of small quantity of Cr in enhancing the electrocatalytic activity as well as robustness of single-atom catalyst and suggests the design of the multifunctional robust electrocatalysts for long-term H2 evolution application.

6.
Physiol Plant ; 176(2): e14285, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38606764

RESUMO

AIMS: Geophytic plants have evolved to develop underground storage organs (USO) in the active growing season to withstand harsh environments as well as to coordinate growth and reproduction when conditions are favourable. Saffron is an autumn flowering geophyte and an expensive spice crop restricted to certain geographical locations in the world. Saffron, being sterile, does not produce seeds and thus propagates only through corms, the quality of which determines its yield. Corm development in saffron is unexplored and the underlying molecular mechanism is still elusive. In this study, we performed an extensive characterisation of the transcriptional dynamics in the source (leaf) and sink (corm) tissues during corm development in saffron. KEY RESULTS: Via morphological and transcriptome studies, we identified molecular factors regulating corm development process in saffron, which defined corm development into three stages: the initiation stage demonstrates enhanced vegetative growth aboveground and swelling of shoot base belowground due to active cell division & carbohydrate storage; the bulking stage comprises of increased source and sink strength, active photosynthesis, circadian gating and starch accumulation; the maturation stage represents reduced source and sink strength, lowered photosynthesis, sugar transport, starch synthesis and cell cycle arrest. UTILITY: The global view of transcriptional changes in source and sink identifies similar and new molecular factors involved in the saffron corm development process compared to USO formation in other geophytes and provides a valuable resource for dissecting the molecular network underlying the corm development. We propose a hypothetical model based on data analysis, of how molecular factors via environmental cues can regulate the corm development process in saffron.


Assuntos
Crocus , Crocus/genética , Crocus/metabolismo , Transcriptoma/genética , Folhas de Planta , Amido/metabolismo
7.
Sci Rep ; 14(1): 9342, 2024 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-38653763

RESUMO

Chickpea is a highly nutritious protein-rich source and one of the major crops to alleviate global malnutrition, but poor seed quality affects its productivity. Seed quality is essential for better crop establishment and higher yields, particularly in the uncertain climate change. The present study investigated the impact of botanical priming versus hydropriming and bavistin seed treatment on chickpea seeds. A detailed physiological (germination percentage, root and shoot length, vigour index) and biochemical (amylase, protease, dehydrogenase, phytase, and lipid peroxidation) analysis was carried out in order to assess the effect of priming treatments. Turmeric-primed seeds showed better germination rate (94.5%), seedling length, enzyme activity, and lower malondialdehyde (MDA) content. Sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis revealed the expression of minor polypeptides of albumin and globulin in the primed seeds. Moreover, field experiments indicated increased crop growth, vigour, days to 50% flowering, yield and its attributing traits in turmeric-primed seeds. Botanical priming can increase chickpea yield by up to 16% over the control group. This low-cost and eco-friendly technique enhances seed and crop performance, making it a powerful tool for augmenting chickpea growth. Therefore, chickpea growers must adopt botanical priming techniques to enhance the quality of seed and crop performance. Moreover, this approach is environmentally sustainable and can help conserve natural resources in the long term. Therefore, this new approach must be widely adopted across the agricultural industry to ensure sustainable and profitable farming practices.


Assuntos
Cicer , Produtos Agrícolas , Germinação , Sementes , Cicer/crescimento & desenvolvimento , Cicer/efeitos dos fármacos , Cicer/metabolismo , Sementes/crescimento & desenvolvimento , Sementes/efeitos dos fármacos , Sementes/metabolismo , Germinação/efeitos dos fármacos , Produtos Agrícolas/crescimento & desenvolvimento , Produtos Agrícolas/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Plântula/efeitos dos fármacos , Plântula/metabolismo , Proteínas de Plantas/metabolismo , Malondialdeído/metabolismo
8.
ACS Photonics ; 11(3): 1244-1251, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38523744

RESUMO

We study the photophysical stability of ensemble near-surface nitrogen vacancy (NV) centers in diamond under vacuum and air. The optically detected magnetic resonance contrast of the NV centers was measured following exposure to laser illumination, showing opposing trends in air compared to vacuum (increasing by up to 9% and dropping by up to 25%, respectively). Characterization using X-ray photoelectron spectroscopy (XPS) suggests a surface reconstruction: In air, atmospheric oxygen adsorption on a surface leads to an increase in NV- fraction, whereas in vacuum, net oxygen desorption increases the NV0 fraction. NV charge state switching is confirmed by photoluminescence spectroscopy. Deposition of ∼2 nm alumina (Al2O3) over the diamond surface was shown to stabilize the NV charge state under illumination in either environment, attributed to a more stable surface electronegativity. The use of an alumina coating on diamond is therefore a promising approach to improve the resilience of NV sensors.

10.
Adv Biomed Res ; 13: 4, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38525391

RESUMO

Background: To determine the superiority of the combination of endoscopic retrograde cholangiopancreatography (ERCP) and digital single-operator cholangioscopy (DSOC) in the same sitting over the individual modality alone in patients with indeterminate biliary strictures. Materials and Methods: A randomized study enrolled 60 adult patients with biliary strictures who were randomized into two groups: ERCP + DSOC and ERCP/DSOC. Histopathologic or cytologic assessment was performed in terms of benign, indeterminate, or malignant nature of the strictures. Procedural adverse events were documented. Accuracy in terms of sensitivity (Sn), specificity (Sp), and predictive value [positive (PPV) and negative (NPV)] were noted. Results: As per final diagnosis, in ERCP/DSOC group, there were 12 (40%) benign cases and 18 (60%) malignant cases, and in group ERCP + DSOC, there were 8 (26.67%) benign cases and 22 (73.33%) malignant cases. ERCP/DSOC labeled 16 (53.33%) patients as benign, 8 (26.67%) as malignant, and 6 (20%) as indeterminate, while ERCP + DSOC labeled 8 (26.67%) as benign, 17 (56.67%) as malignant, and 5 (16.67%) as indeterminate. The Sn, Sp, PPV, and NPV of ERCP/DSOC were 44.4%, 75%, 100%, and 56.25%, and for ERCP + DSOC was 77.27%, 62.50%, 100%, and 62.5%, respectively (P = 0.033). Side effects were statistically similar in both the groups (P > 0.05). Conclusion: To conclude, the combination of ERCP with DSOC is safe and effective with higher diagnostic sensitivity (77.27%) in comparison to standard ERCP or DSOC alone (44.4%) for the diagnosis of biliary strictures.

11.
Org Biomol Chem ; 22(15): 3053-3058, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38545870

RESUMO

We report a competent and selective hydrosilylation of nitriles and tertiary amides catalyzed by the readily available zinc bis(hexamethyldisilazide) under solvent-free and mild conditions, making it a sustainable and desirable alternative to existing methods. Both protocols afforded high conversion, superior selectivity, and a broad substrate scope, from electron-withdrawing to electron-donating and heterocyclic substitutions.

12.
Anim Biotechnol ; 35(1): 2319622, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38437001

RESUMO

The objective of the present study was to identify genomic regions influencing economic traits in Murrah buffaloes using weighted single step Genome Wide Association Analysis (WssGWAS). Data on 2000 animals, out of which 120 were genotyped using a double digest Restriction site Associated DNA (ddRAD) sequencing approach. The phenotypic data were collected from NDRI, India, on growth traits, viz., body weight at 6M (month), 12M, 18M and 24M, production traits like 305D (day) milk yield, lactation length (LL) and dry period (DP) and reproduction traits like age at first calving (AFC), calving interval (CI) and first service period (FSP). The biallelic genotypic data consisted of 49353 markers post-quality check. The heritability estimates were moderate to high, low to moderate, low for growth, production, reproduction traits, respectively. Important genomic regions explaining more than 0.5% of the total additive genetic variance explained by 30 adjacent SNPs were selected for further analysis of candidate genes. In this study, 105 genomic regions were associated with growth, 35 genomic regions with production and 42 window regions with reproduction traits. Different candidate genes were identified in these genomic regions, of which important are OSBPL8, NAP1L1 for growth, CNTNAP2 for production and ILDR2, TADA1 and POGK for reproduction traits.


Assuntos
Búfalos , Estudo de Associação Genômica Ampla , Feminino , Animais , Búfalos/genética , Lactação/genética , Genoma/genética , Leite , Genômica , Fenótipo , Polimorfismo de Nucleotídeo Único/genética
13.
Biochem Biophys Res Commun ; 706: 149764, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38484569

RESUMO

Recent studies propose that primary transcripts of miRNAs (pri-miRNAs) contain small Open Reading Frames (ORFs) capable of encoding miRNA-encoded peptides (miPEPs). These miPEPs can function as transcriptional regulators for their corresponding pri-miRNAs, ultimately enhancing mature miRNA accumulation. Notably, pri-miR408 encodes the functional peptide miPEP408, regulating expression of miR408 and its target genes, providing plant tolerance to stresses. While miPEPs are crucial regulators, the factors governing them are have not been studied in detail. Here, we explored the light-dependent regulation of miPEP408 in Arabidopsis. Expression analysis during dark-light transitions revealed light-induced transcription and accumulation of the miPEP408. As the promoter of miR408 contains cis-acting elements responsible for binding to the bZIP-type transcription factor ELONGATED HYPOCOTYL5 (HY5), known for light-mediated regulation in plants, we studied its involvement in the regulation of miR408. Analysis of HY5 mutant (hy5-215), complemented line (HY5OX/hy5), and CONSTITUTIVE PHOTOMORPHOGENIC 1 mutant (cop1-4) plants supported HY5's positive regulation of miPEP408. Grafting and GUS assays further suggested the role of HY5 as a shoot-root mobile signal inducing light-dependent miPEP408 expression. This study underscores the regulatory impact of light on small peptides, exemplified by miPEP408, mediated by the key transcription factor HY5.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , MicroRNAs , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Ligação Proteica , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Fatores de Transcrição de Zíper de Leucina Básica/genética , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Peptídeos/genética , Peptídeos/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Regulação da Expressão Gênica de Plantas
14.
JHEP Rep ; 6(4): 100993, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38425452

RESUMO

Background & Aims: Maintenance of abstinence in alcohol-related liver disease (ARLD) is a major unmet therapeutic need. Digital therapeutics can deliver ongoing behavioural therapy, in real-time, for chronic conditions. The aim of this project was to develop and clinically test AlcoChange, a novel digital therapeutic for ARLD. Methods: AlcoChange was developed using validated behaviour change techniques and a digital alcohol breathalyser. This was an open-label, single-centre study. Patients with ARLD, ongoing alcohol use (within 1 month) and possession of a suitable smartphone were eligible. Patients were recruited from inpatient and outpatient settings, and received AlcoChange therapy for 3 months. The primary outcome was reduction in alcohol use from baseline to 3 months, measured by timeline follow-back. Secondary outcomes included: (i) compliance with the AlcoChange app, (ii) alcohol-related and all-cause hospital re-admissions up to 1 year, (iii) qualitative analysis to determine factors associated with compliance. Results: Sixty-five patients were recruited, of whom 41 completed the study per protocol. Patients compliant with the intervention (>60 logins over 3 months) had a significant reduction in alcohol use from baseline compared to non-compliant patients (median [IQR]: -100% [100% to -55.1%] vs. -57.1% [-95.3% to +32.13%], p = 0.029). The proportion attaining abstinence at 3 months was higher in the compliant group (57.1% vs. 22.2%, p = 0.025). The compliant group had a significantly decreased risk of subsequent alcohol-related re-admission up to 12 months (p = 0.008). Qualitative analysis demonstrated that receiving in-app feedback and the presence of a health-related 'sentinel event' were predictors of compliance with the intervention. Conclusions: Use of the novel digital therapeutic, AlcoChange, was associated with a significant reduction in alcohol use and an increase in the proportion of patients with ARLD attaining abstinence. Definitive randomised trials are warranted for this intervention. Impact and implications: Alcohol-related liver disease (ARLD) is an increasing health problem worldwide. The main cause of death and disability in ARLD is ongoing alcohol consumption, but few patients receive medications or talking therapy to maintain abstinence. This study demonstrated that a digital therapeutic, linked to a smartphone, may help reduce alcohol consumption and alcohol-related hospital admissions in these patients. If validated in larger, randomised, trials, digital therapeutics may have a role in the primary and secondary prevention of complicatons from ARLD.

15.
Chem Soc Rev ; 53(9): 4786-4827, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38545658

RESUMO

This review summarizes the structural and synthetic aspects of heterocyclic molecules incorporating an atom of a hypervalent main-group element. The term "hypervalent" has been suggested for derivatives of main-group elements with more than eight valence electrons, and the concept of hypervalency is commonly used despite some criticism from theoretical chemists. The significantly higher thermal stability of hypervalent heterocycles compared to their acyclic analogs adds special features to their chemistry, particularly for bromine and iodine. Heterocyclic compounds of elements with double bonds are not categorized as hypervalent molecules owing to the zwitterionic nature of these bonds, resulting in the conventional 8-electron species. This review is focused on hypervalent heterocyclic derivatives of nonmetal main-group elements, such as boron, silicon, nitrogen, carbon, phosphorus, sulfur, selenium, bromine, chlorine, iodine(III) and iodine(V).

16.
BMJ Case Rep ; 17(2)2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38350705

RESUMO

Bartter syndrome (BS) is a rare genetic tubulopathy affecting the loop of Henle leading to salt wasting. It is commonly seen in utero or in the early neonatal period. Rare cases of acquired BS are reported in association with infections like tuberculosis, granulomatous conditions like sarcoidosis, autoimmune diseases and drugs. The mainstay of management includes potassium, calcium and magnesium supplementation. We report the case of a woman in her 50s with a history of type 2 diabetes mellitus for the last 10 years, who presented with diabetic foot ulcers and generalised weakness with ECG changes suggestive of hypokalaemia. She had severe hypokalaemia with high urine potassium excretion and hypochloraemic metabolic alkalosis. She poorly responded to intravenously administered potassium supplements and had persistent hypokalaemia. On further evaluation of the persistent hypokalaemia, a diagnosis of idiopathic Bartter-like phenotype was made. She responded well to tablet indomethacin and is presently asymptomatic and is being maintained on tablet indomethacin after 6 months of follow-up.


Assuntos
Síndrome de Bartter , Diabetes Mellitus Tipo 2 , Hipopotassemia , Recém-Nascido , Feminino , Humanos , Síndrome de Bartter/complicações , Síndrome de Bartter/diagnóstico , Síndrome de Bartter/tratamento farmacológico , Hipopotassemia/complicações , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/tratamento farmacológico , Fenótipo , Potássio/metabolismo , Indometacina/uso terapêutico , Comprimidos
17.
Plant Cell Environ ; 47(4): 1207-1223, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38164016

RESUMO

Throughout evolution, plants have developed strategies to confront and alleviate the detrimental impacts of abiotic stresses on their growth and development. The combat strategies involve intricate molecular networks and a spectrum of early and late stress-responsive pathways. Plant peptides, consisting of fewer than 100 amino acid residues, are at the forefront of these responses, serving as pivotal signalling molecules. These peptides, with roles similar to phytohormones, intricately regulate plant growth, development and facilitate essential cell-to-cell communications. Numerous studies underscore the significant role of these small peptides in coordinating diverse signalling events triggered by environmental challenges. Originating from the proteolytic processing of larger protein precursors or directly translated from small open reading frames, including microRNA (miRNA) encoded peptides from primary miRNA, these peptides exert their biological functions through binding with membrane-embedded receptor-like kinases. This interaction initiates downstream cellular signalling cascades, often involving major phytohormones or reactive oxygen species-mediated mechanisms. Despite these advances, the precise modes of action for numerous other small peptides remain to be fully elucidated. In this review, we delve into the dynamics of stress physiology, mainly focusing on the roles of major small signalling peptides, shedding light on their significance in the face of changing environmental conditions.


Assuntos
Reguladores de Crescimento de Plantas , Plantas , Reguladores de Crescimento de Plantas/metabolismo , Plantas/metabolismo , Desenvolvimento Vegetal , Peptídeos/metabolismo , Estresse Fisiológico/genética
18.
Nano Lett ; 24(5): 1611-1619, 2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38267020

RESUMO

The nanoscale arrangement of ligands can have a major effect on the activation of membrane receptor proteins and thus cellular communication mechanisms. Here we report on the technological development and use of tailored DNA origami-based molecular rulers to fabricate "Multiscale Origami Structures As Interface for Cells" (MOSAIC), to enable the systematic investigation of the effect of the nanoscale spacing of epidermal growth factor (EGF) ligands on the activation of the EGF receptor (EGFR). MOSAIC-based analyses revealed that EGF distances of about 30-40 nm led to the highest response in EGFR activation of adherent MCF7 and Hela cells. Our study emphasizes the significance of DNA-based platforms for the detailed investigation of the molecular mechanisms of cellular signaling cascades.


Assuntos
Fator de Crescimento Epidérmico , Receptores ErbB , Humanos , DNA/química , Fator de Crescimento Epidérmico/química , Fator de Crescimento Epidérmico/metabolismo , Receptores ErbB/metabolismo , Células HeLa , Ligantes , Transdução de Sinais
19.
3 Biotech ; 14(2): 54, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38282912

RESUMO

In the present investigation, a soil isolate Pseudomonas aeruginosa CSPS4 was used for retrieving the l-asparaginase encoding gene (Asn_PA) of size 1089 bp. The gene was successfully cloned into the pET28a (+) vector and expressed into E. coli BL21(DE3) for characterization of the protein. The recombinant rAsn_PA enzyme was purified by affinity chromatography using Ni-NTA2+ resins. Molecular weight analysis using SDS-PAGE unveiled rAsn_PA as a monomeric protein of molecular weight ~ 35 kDa. On characterization, the recombinant rAsn_PA showed optimum pH and temperature of 6.0 and 60 °C, respectively, along with significant stability at 50-70 °C, along with 50% residual activity at 80 °C after 3 h of incubation. Similarly, the rAsn_PA exhibited asparaginase activity over a broad pH range between 4 and 8. The enzyme was not significantly inhibited in the presence of detergents. The rAsn_PA was grouped into the asparaginase-glutaminase family II due to the glutaminase activity. The purified rAsn_PA showed antitumor activity by exhibiting a cytotoxic effect on three different cell lines, where IC50 of purified rAsn_PA was 2.3 IU, 3.7 IU, and 20.5 IU for HL-60, MOLM-13, and K-562 cell lines, respectively. Thus, recombinant rAsn_PA of P. aeruginosa CSPS4 may also be explored as an antitumor agent after reducing or minimizing the glutaminase activity. Thermo-acidophilic properties of rAsn_PA make it a novel enzyme that needs to be further investigated.

20.
Chemistry ; 30(6): e202303300, 2024 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-37929771

RESUMO

Owing to their high reactivity and selectivity, variations in the spin ground state and a range of possible pathways, high-valent FeIV =O species are popular models with potential bioinspired applications. An interesting example of a structure-reactivity pattern is the detailed study with five nonheme amine-pyridine pentadentate ligand FeIV =O species, including N4py: [(L1 )FeIV =O]2+ (1), bntpen: [(L2 )FeIV =O]2+ (2), py2 tacn: [(L3 )FeIV =O]2+ (3), and two isomeric bispidine derivatives: [(L4 )FeIV =O]2+ (4) and [(L5 )FeIV =O]2+ (5). In this set, the order of increasing reactivity in the hydroxylation of cyclohexane differs from that with cyclohexadiene as substrate. A comprehensive DFT, ab initio CASSCF/NEVPT2 and DLPNO-CCSD(T) study is presented to untangle the observed patterns. These are well reproduced when both activation barriers for the C-H abstraction and the OH rebound are taken into account. An MO, NBO and deformation energy analysis reveals the importance of π(pyr) → π*xz (FeIII -OH) electron donation for weakening the FeIII -OH bond and thus reducing the rebound barrier. This requires that pyridine rings are oriented perpendicularly to the FeIII -OH bond and this is a subtle but crucial point in ligand design for non-heme iron alkane hydroxylation.

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