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1.
Front Chem ; 12: 1371978, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38595704

RESUMO

The first photocatalytic trichloromethyl radical-triggered annulative reactions of amide-linked 1,7-diynes with polyhalomethanes were established for the flexible assembly of functionalized quinolin-2(1H)-ones with generally acceptable yields. With the installation of the aryl group (R1) into the alkynyl moiety, C-center radical-initiated Kharasch-type addition/nucleophilic substitution/elimination cascade to produce quinolin-2(1H)-ones-incorporating gem-dihaloalkene, whereas three examples of polyhalogenated quinolin-2(1H)-ones were afforded when amide-linked 1,7-diynes bearing two terminal alkyne units were subjected to BrCX3 by exploiting dry acetonitrile as a solvent.

2.
Brief Bioinform ; 25(3)2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38632951

RESUMO

In cancer genomics, variant calling has advanced, but traditional mean accuracy evaluations are inadequate for biomarkers like tumor mutation burden, which vary significantly across samples, affecting immunotherapy patient selection and threshold settings. In this study, we introduce TMBstable, an innovative method that dynamically selects optimal variant calling strategies for specific genomic regions using a meta-learning framework, distinguishing it from traditional callers with uniform sample-wide strategies. The process begins with segmenting the sample into windows and extracting meta-features for clustering, followed by using a pre-trained meta-model to select suitable algorithms for each cluster, thereby addressing strategy-sample mismatches, reducing performance fluctuations and ensuring consistent performance across various samples. We evaluated TMBstable using both simulated and real non-small cell lung cancer and nasopharyngeal carcinoma samples, comparing it with advanced callers. The assessment, focusing on stability measures, such as the variance and coefficient of variation in false positive rate, false negative rate, precision and recall, involved 300 simulated and 106 real tumor samples. Benchmark results showed TMBstable's superior stability with the lowest variance and coefficient of variation across performance metrics, highlighting its effectiveness in analyzing the counting-based biomarker. The TMBstable algorithm can be accessed at https://github.com/hello-json/TMBstable for academic usage only.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Genômica/métodos , Genoma , Algoritmos
3.
Food Chem ; 446: 138880, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38432140

RESUMO

Biodegradable food packaging films with good antimicrobial properties are highly sought after for prolonging the shelf-life of fruits and vegetables whilst minimizing waste streams originating from the food sector. In this work, a series of PBAT/PLA food packaging films containing sodium dehydroacetate-loaded diatomite (SD/D) as an antimicrobial agent were fabricated. Structural analyses showed that the sodium dehydroacetate was incorporated into the pores of the diatomite. A uniform dispersion of SD/D in the composite films effectively enhanced water and gas permeability, whilst also giving the films good mechanical properties. The slow release of SD endowed the composite films with long-acting antibacterial ability (>90 % bacteriostasis rate for E. coli and >85 % bacteriostasis rate for S. aureus). The composite films were able to effectively maintain the quality of banana fruits during storage at room temperature, encouraging their use in food applications where non-biodegradable petrochemical-derived packaging films have traditionally been used.


Assuntos
Anti-Infecciosos , Terra de Diatomáceas , Embalagem de Alimentos , Pironas , Antibacterianos/farmacologia , Antibacterianos/química , Água , Escherichia coli , Staphylococcus aureus , Poliésteres/química , Anti-Infecciosos/farmacologia
4.
Front Immunol ; 15: 1345586, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38515756

RESUMO

Introduction: T cell receptor (TCR) repertoires provide valuable insights into complex human diseases, including cancers. Recent advancements in immune sequencing technology have significantly improved our understanding of TCR repertoire. Some computational methods have been devised to identify cancer-associated TCRs and enable cancer detection using TCR sequencing data. However, the existing methods are often limited by their inadequate consideration of the correlations among TCRs within a repertoire, hindering the identification of crucial TCRs. Additionally, the sparsity of cancer-associated TCR distribution presents a challenge in accurate prediction. Methods: To address these issues, we presented DeepLION2, an innovative deep multi-instance contrastive learning framework specifically designed to enhance cancer-associated TCR prediction. DeepLION2 leveraged content-based sparse self-attention, focusing on the top k related TCRs for each TCR, to effectively model inter-TCR correlations. Furthermore, it adopted a contrastive learning strategy for bootstrapping parameter updates of the attention matrix, preventing the model from fixating on non-cancer-associated TCRs. Results: Extensive experimentation on diverse patient cohorts, encompassing over ten cancer types, demonstrated that DeepLION2 significantly outperformed current state-of-the-art methods in terms of accuracy, sensitivity, specificity, Matthews correlation coefficient, and area under the curve (AUC). Notably, DeepLION2 achieved impressive AUC values of 0.933, 0.880, and 0.763 on thyroid, lung, and gastrointestinal cancer cohorts, respectively. Furthermore, it effectively identified cancer-associated TCRs along with their key motifs, highlighting the amino acids that play a crucial role in TCR-peptide binding. Conclusion: These compelling results underscore DeepLION2's potential for enhancing cancer detection and facilitating personalized cancer immunotherapy. DeepLION2 is publicly available on GitHub, at https://github.com/Bioinformatics7181/DeepLION2, for academic use only.


Assuntos
Neoplasias , Receptores de Antígenos de Linfócitos T , Humanos , Peptídeos , Imunoterapia , Neoplasias/genética
5.
Chemistry ; : e202400005, 2024 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-38497560

RESUMO

New chiral targets of orientational chirality have been designed and asymmetrically synthesized by taking advantage of N-sulfinyl imine-directed nucleophilic addition/oxidation, Suzuki-Miyaura, and Sonogashira cross-coupling reactions. Orientation of single isomers has been selectively controlled by using aryl/alkynyl levers [C(sp2)-C(sp) axis] and tBuSO2- protecting group on nitrogen as proven by X-ray diffraction analysis. The key structural characteristic of resulting orientational products is shown by remote through-space blocking manner. Seventeen examples of multi-step synthesis were obtained with modest to good chemical yields and complete orientational selectivity.

6.
J Org Chem ; 89(7): 4877-4887, 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38457276

RESUMO

General and convenient visible-light-promoted alkylsulfonylation and cyanoalkylsulfonylation of MBH adducts have been developed through the multicomponent insertion of sulfur dioxide, enabling the assembly of two C-S bonds to generate structurally diverse allylic alkylsulfones (43 examples in total). The reaction of MBH adducts with potassium alkyltrifluoroborates and 1,4-diazabicyclo[2.2.2]octane bis(sulfur dioxide) adduct afforded sulfones with generally good yields. Notably, the addition of N,N,N',N'-tetramethylethylenediamine as a base into the photocatalytic system led to yielding an alkyl sulfonyl unit and cyano group-anchored trisubstituted alkenes by utilizing cycloketone oxime esters as C-radical precursors. Both of these reactions have constructed two C-S bonds, and all desired products were obtained in moderate to excellent yields with complete stereospecificity.

7.
Int J Neurosci ; : 1-10, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38497924

RESUMO

OBJECTIVE: To observe the efficacy and safety of sodium valproate (VPA) compared to levetiracetam (LEV) in the treatment of severe traumatic brain injury (sTBI). METHODS: In this blind, prospective study, eighty-four sTBI patients who had craniotomy from August 2021 to August 2023 were randomly split into two groups through random number table method: LEV and VPA, each with 42 patients. Both received comprehensive treatment post-craniotomy. LEV group: LEV injection on surgery day, transitioning to LEV tablets from day two. VPA group: VPA injection on surgery day, switching to VPA extended-release tablets from day two. The study compared hospital stay, neurological function, clinical outcomes, seizures, and drug reactions between groups. RESULTS: The length of hospital stay showed no significant difference between the LEV and VPA groups. Both groups demonstrated improved neurological function post-treatment (NIHSS and BI scores), with no significant between-group differences. Clinical outcomes at 3 months post-treatment were similar in both groups. Seizure occurrence within 3 months after treatment showed no significant difference between the LEV (19.05%) and VPA (23.81%) groups. However, the VPA group experienced a significantly higher rate of drug-related adverse reactions (40.48%) compared to the LEV group (21.43%). CONCLUSION: Both VPA and LEV are effective in treating sTBI, showing no significant difference in improving neurological function, daily life abilities, treatment outcomes, and seizure occurrence. However, VPA treatment exhibited a significantly higher incidence of drug-related adverse reactions compared to LEV, indicating that LEV might be a safer option for sTBI treatment.

8.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 46(1): 43-48, 2024 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-38433630

RESUMO

Objective To analyze the correlations between platelet-related parameters and the incidence of anxiety and depression in the patients undergoing peritoneal dialysis(PD),and evaluate the efficacy of the parameters in the diagnosis of anxiety and depression in PD patients. Methods A total of 245 patients undergoing PD in the First Affiliated Hospital of Hebei North University from September 2022 to February 2023 were enrolled.The generalized anxiety scale(GAD-7) and the patient health questionnaire(PHQ-9) were used to evaluate the anxiety and depression of the patients,respectively.The personal information and biochemical indicators of the patients were collected,and the platelet count(PLT),mean platelet volume(MPV),and platelet distribution width(PDW) were measured.Logistic regression was adopted to analyze the relationships of platelet-related parameters with anxiety and depression in PD patients. Results Among the 245 patients undergoing PD,the incidences of anxiety and depression were 15.9% and 38.0%,respectively.There were differences in the dialysis period(Z=-2.358,P=0.018;Z=-3.079,P=0.002),MPV(Z=-4.953,P<0.001;Z=-7.878,P<0.001),and PDW(Z=-4.587,P<0.001;Z=-7.367,P<0.001) between the anxiety group and the non-anxiety group as well as between the depression group and the non-depression group.The correlation analysis showed that MPV(r=0.358,P<0.001;r=0.489,P<0.001) and PDW(r=0.340,P<0.001;r=0.447,P<0.001) were positively correlated with anxiety and depression in the patients undergoing PD.The Logistic regression model showed that MPV(P=0.022,P=0.011),PDW(P=0.041,P=0.018),and dialysis period(P=0.011,P=0.030) were independent risk factors for the anxiety and depressive state in PD patients.The areas under the receiver operating characteristic curve of MPV in the diagnosis of anxiety and depression in PD patients were 0.750 and 0.800,respectively,and those of PDW were 0.732 and 0.780,respectively. Conclusion MPV and PDW have high efficacy in the diagnosis of anxiety and depression associated with PD and can be used as objective indicators to evaluate the anxiety and depression in the patients undergoing PD.


Assuntos
Ansiedade , Diálise Peritoneal , Humanos , Diálise Peritoneal/efeitos adversos , Hospitais , Modelos Logísticos , Curva ROC
9.
Cerebellum ; 2024 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-38429489

RESUMO

COQ8A plays an important role in the biosynthesis of coenzyme Q10 (CoQ10), and variations in COQ8A gene are associated with primary CoQ10 deficiency-4 (COQ10D4), also known as COQ8A-ataxia. The current understanding of the association between the specific variant type, the severity of CoQ10 deficiency, and the degree of oxidative stress in individuals with primary CoQ10 deficiencies remains uncertain. Here we provide a comprehensive analysis of the clinical and genetic characteristics of an 18-year-old patient with COQ8A-ataxia, who exhibited novel compound heterozygous variants (c.1904_1906del and c.637C > T) in the COQ8A gene. These variants reduced the expression levels of COQ8A and mitochondrial proteins in the patient's muscle and skin fibroblast samples, contributed to mitochondrial respiration deficiency, increased ROS production and altered mitochondrial membrane potential. It is worth noting that the optimal treatment for COQ8A-ataxia remains uncertain. Presently, therapy consists of CoQ10 supplementation, however, it did not yield significant improvement in our patient's symptoms. Additionally, we reviewed the response of CoQ10 supplementation and evolution of patients in previous literatures in detail. We found that only half of patients could got notable improvement in ataxia. This research aims to expand the genotype-phenotype spectrum of COQ10D4, address discrepancies in previous reviews regarding the effectiveness of CoQ10 in these disorders, and help to establish a standardized treatment protocol for COQ8A-ataxia.

10.
Molecules ; 29(4)2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38398533

RESUMO

We present the first example of visible-light-mediated multicomponent annulation of 1,7-diynes by taking advantage of quadruple cleavage olf carbon-halogen bonds of BrCCl3 to generate a C1 synthon, which was adeptly applied to the preparation of skeletally diverse 3-benzoyl-quinolin-2(1H)-one acetates in moderate to good yields. Controlled experiments demonstrated that H2O acted as both oxygen and hydrogen sources, and gem-dichlorovinyl carbonyl compound exhibited as a critical intermediate in this process. The mechanistic pathway involves Kharasch-type addition/6-exo-dig cyclization/1,5-(SN")-substitution/elimination/binucleophilic 1,6-addition/proton transfer/tautomerization sequence.

11.
J Am Heart Assoc ; 13(5): e032326, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38390817

RESUMO

BACKGROUND: Approximately half of patients who achieve successful reperfusion do not achieve functional independence. The present study sought to investigate the clinical outcomes and safety of intraarterial or intravenous tirofiban as adjunct therapy in patients with acute basilar artery occlusion who had achieved successful recanalization with endovascular treatment. METHODS AND RESULTS: In the national, prospective BASILAR (Endovascular Treatment for Acute Basilar Artery Occlusion Study) registry, 458 patients who met inclusion criteria were divided into 3 groups based on tirofiban administration (no tirofiban, n=262; intravenous tirofiban, n=101; intraarterial+intravenous tirofiban, n=95). Their clinical outcomes were compared with 90-day modified Rankin Scale scores. Adjusted odds ratios (aORs) and 95% CIs were obtained by logistic regression models and propensity score matching. Safety outcomes included any intracranial hemorrhage (ICH), symptomatic ICH, and mortality. Among 458 included patients, 184 (40.2%) achieved a favorable outcome (modified Rankin Scale score 0-3). There were no differences between the intravenous tirofiban group and the no tirofiban group in terms of safety and clinical outcomes (all P>0.05). Compared with the no tirofiban group, the intraarterial+intravenous tirofiban group had higher odds of 90-day modified Rankin Scale score 0 to 3 (aOR, 2.44 [95% CI, 1.30-4.64], P=0.006) and lower 3-month mortality (aOR, 0.38 [95% CI, 0.19-0.71], P=0.002) without an increase in any ICH (aOR, 0.34 [95% CI, 0.09-1.01], P=0.07) or symptomatic ICH (aOR, 0.23 [95% CI, 0.03-0.90], P=0.05). Similar results of intraarterial+intravenous tirofiban on improving clinical outcomes were detected in novel cohorts constructed by propensity score matching. CONCLUSIONS: Intraarterial+intravenous rather than intravenous tirofiban improved clinical outcomes without increasing the frequency of symptomatic ICH among patients with basilar artery occlusion after successful endovascular treatment. Further studies are needed to delineate the roles of intraarterial+intravenous tirofiban in patients with basilar artery occlusion receiving endovascular treatment.


Assuntos
Arteriopatias Oclusivas , Procedimentos Endovasculares , Acidente Vascular Cerebral , Humanos , Tirofibana/uso terapêutico , Artéria Basilar/diagnóstico por imagem , Estudos Prospectivos , Terapia Trombolítica/efeitos adversos , Terapia Trombolítica/métodos , Resultado do Tratamento , Hemorragias Intracranianas/etiologia , Arteriopatias Oclusivas/diagnóstico por imagem , Arteriopatias Oclusivas/tratamento farmacológico , Sistema de Registros , Procedimentos Endovasculares/efeitos adversos , Trombectomia
12.
J Fish Dis ; : e13930, 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38349841

RESUMO

Large yellow croaker (Larimichthys crocea) is a vital marine-cultured species in China. Large yellow croaker iridovirus (LYCIV) can cause a high mortality rate in L. crocea. Rapid and convenient detection of LYCIV is an urgent demand for diagnosis. In this study, rapid and simple recombinase polymerase amplification (RPA), real-time RPA and RPA combined with lateral flow dipstick (RPA-LFD) methods were developed for the detection of LYCIV based on the conserved sequence of the LYCIV major capsid protein (MCP) gene. With these optimized RPA analyses, LYCIV detection could be completed within 20 min at 40°C. Both RPA and real-time RPA could detect viral DNA as low as 102 copies/µL, while the detection limit of RPA-LFD was 101 copies/µL, and there was no cross-reaction with other aquatic pathogens (KHV, CyHV-2, GCRV-JX01, SVCV, LCDV and LMBV). In practical evaluation of RPA, real-time RPA and RPA-LFD methods, the results showed consistency with the general PCR detection. In short, the developed RPA, real-time RPA and RPA-LFD analyses could be simple, rapid, sensitive and reliable methods for field diagnosis of LYCIV infection and have significant potential in the protection of LYCIV infection.

13.
RSC Adv ; 14(4): 2792-2795, 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38234866

RESUMO

Two 8,8' disubstituted binaphthyl ligands have been designed and synthesized in 3.1% and 11.4% overall yield, respectively. X-ray structure analysis demonstrated that a unique chiral microenvironment was created. With the assistance of a new aggregation-induced polarization (AIP) technology, chiral aggregates were determined as the fraction of polar solvent increased in the nonpolar/polar solvent system, which indicated their potential in modern asymmetric synthesis and catalysis.

14.
Int J Biol Macromol ; 255: 127921, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37944741

RESUMO

To reduce the white pollution, the eco-friendly biodegradable poly (butylene adipate-co-terephthalate) (PBAT)-based films had attracted increasing interests worldwide. However, the high-cost of the PBAT had limited the large-scale development and application. In this work, 10 wt% low-cost lignin was introduced into the PBAT to prepare composite films by melt blending and blow molding, and the POSS(epoxy)8 was selected as the compatibilizer to improve the compatibility of PBAT and lignin. The maximum tensile strength and the nominal strain at break subsequently increased by 48.2 % and 21.4 % respectively, while the water vapor permeability enhanced by 9.9 %. Furthermore, the UV aging resistance of PBAT/lignin films were significantly improved, with only 1 wt% POSS(epoxy)8 content. This work provides an efficient strategy to foster the end-user confidence in the low-cost and eco-friendly biodegradable polymer materials with efficient performance.


Assuntos
Lignina , Poliésteres , Resinas Epóxi , Adipatos
15.
J Neurol ; 271(2): 864-876, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37847292

RESUMO

OBJECTIVE: Mitochondrial myopathy without extraocular muscles involvement (MiMy) represents a distinct form of mitochondrial disorder predominantly affecting proximal/distal or axial muscles, with its phenotypic, genotypic features, and long-term prognosis poorly understood. METHODS: A cross-sectional study conducted at a national diagnostic center for mitochondrial disease involved 47 MiMy patients, from a cohort of 643 mitochondrial disease cases followed up at Qilu Hospital from January 1, 2000, to January 1, 2021. We compared the clinical, pathological, and genetic features of MiMy to progressive external ophthalmoplegia (PEO) and mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) patients. RESULTS: MiMy patients demonstrated a more pronounced muscle involvement syndrome, with lower 6MWT scores, higher FSS, and lower BMI compared to PEO and MELAS patients. Serum levels of creatinine kinase (CK), lactate, and growth and differentiation factor 15 (GDF15) were substantially elevated in MiMy patients. Nearly a third (31.9%) displayed signs of subclinical peripheral neuropathy, mostly axonal neuropathy. Muscle biopsies revealed that cytochrome c oxidase strong (COX-s) ragged-red fibers (RRFs) were a typical pathological feature in MiMy patients. Genetic analysis predominantly revealed mtDNA point pathogenic variants (59.6%) and less frequently single (12.8%) or multiple (4.2%) mtDNA deletions. During the follow-up, a majority (76.1%) of MiMy patients experienced stabilization or improvement after therapeutic intervention. CONCLUSIONS: This study provides a comprehensive profile of MiMy through a large patient cohort, elucidating its unique clinical, genetic, and pathological features. These findings offer significant insights into the diagnostic and therapeutic management of MiMy, ultimately aiming to ameliorate patient outcomes and enhance the quality of life.


Assuntos
Acidose Láctica , Síndrome MELAS , Oftalmoplegia Externa Progressiva Crônica , Acidente Vascular Cerebral , Humanos , Síndrome MELAS/genética , Músculos Oculomotores , Estudos Transversais , Qualidade de Vida , Acidente Vascular Cerebral/patologia , DNA Mitocondrial/genética , Oftalmoplegia Externa Progressiva Crônica/genética , Oftalmoplegia Externa Progressiva Crônica/patologia
16.
Colloids Surf B Biointerfaces ; 234: 113690, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38086276

RESUMO

Functionalization of GO with an amphiphilic block copolymer is designed with an aim to enhance its biocompatibility, however, long copolymer chains can screen the blade effect of GO to sacrifice its antimicrobial activities. To solve this problem, low molecular weight of poly(ethylene glycol) (PEG), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and their block copolymer were respectively introduced onto GO via an isophorone diisocyanate modified GO as a intermediate, followed by a solvent evaporation of an oil-in-water emulsion treatment (SE treatment) to induce block copolymer into polymer micelle via phase separation to refresh the sharp edges of GO. Block copolymer modified GO possessed similar dispersibility and stability to PEG modified GO, and even higher loading capacity of the hydrophobic drug than PHBV modified GO, illustrating its superior properties to homopolymer. PEG, PHBV and their block copolymer modified GO were nontoxic towards ATDC5 cells while cultured for 3 days and compatible with erythrocytes within 8 h. SE treatment enhanced greatly the loading capacity of the hydrophobic drug and the accumulative release reached 91.3% within 24 h. The inhibition zone of the block copolymer modified GO was 14.1 mm and 14.8 mm against E. coli and S. aureus, comparable to that of PEG modified GO. The bacterial reduction rate of the copolymer micelle modified GO was 87.1% and 82.7% towards E. coli and S. aureus, much greater than that of PEG, PHBV and their block copolymer modified GO at a concentration of 1 mg/mL. The antibiofilm capacity of the copolymer micelle modified GO were equal to that of PEG modified, demonstrating its great promise in tissue engineering application for repair of infected tissue defects.


Assuntos
Escherichia coli , Grafite , Micelas , Staphylococcus aureus , Polímeros/farmacologia , Polímeros/química , Polietilenoglicóis/química , Antibacterianos/farmacologia , Poliésteres/química
17.
Eur J Med Chem ; 264: 116026, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38070429

RESUMO

Here we designed and synthesized 58 deferasirox derivatives with the aim of discovering novel antifungal agents. Most compounds exhibited moderate to excellent in vitro antifungal activities against Cryptococcus neoformans H99 with MIC values ranging from 0.25 µg/mL to 16 µg/mL, including ten compounds with MIC values less than 1 µg/mL that were further screened against an additional six pathogenic fungi. This class of compounds showed high potency against Candida glabrata with MIC values ranging from <0.125 µg/mL to 1 µg/mL. We identified that compound 54 has high potency against 14 strains of Candida glabrata spp. and Cryptococcus spp. with MIC values ranging from <0.125 µg/mL to 1 µg/mL. In addition, compound 54 significantly reduced the CFU in a mouse model of disseminated infection with Cryptococcus neoformans H99 at a dose of 10 mg/kg, which is comparable to FLC. Further investigations on compound 54 are currently in progress.


Assuntos
Criptococose , Cryptococcus neoformans , Camundongos , Animais , Antifúngicos/farmacologia , Deferasirox/farmacologia , Testes de Sensibilidade Microbiana , Criptococose/tratamento farmacológico
18.
Mar Environ Res ; 193: 106298, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38101202

RESUMO

To investigate the toxic mechanism of SiO2 nanoparticles (nSiO2) and polystyrene microplastics (mPS) on microalgae Nitzschia closterium f. minutissima, growth inhibition tests were carried out. The growth and biological responses of the algae exposed to nSiO2 (0.5, 1, 2, 5, 10, 30 mg L-1) and mPS (1, 5, 10, 30 and 75 mg L-1) were explored in f/2 media for 96 h. Both micro-/nano-particles (MNPs) inhibited the growth of N. closterium f. minutissima in a concentration- and time-dependent manner. The toxic effect of mPS on N. closterium f. minutissima is higher than that of nSiO2, because silicon is essential for diatoms to maintain cell wall integrity, and the addition of appropriate amounts of nSiO2 can be absorbed and used as a nutrient to promote diatom growth and protect the integrity of the siliceous shell to some extent. Both MNPs induce the production of excess oxidation and activate the cellular antioxidant defense system, leading to increased SOD and CAT activity as a means to resist oxidative damage to the cell, and eliminating excess ROS and maintaining normal cell morphology and metabolism. SEM is consistent with the results of MDA, showing that mPS with high concentrations attach to the surface of algal cells to produce heterogeneous aggregates and disrupt the cell wall and cell membrane, causing the cells to expand and rupture. This study contributes to the understanding of the size effect of MNPs on the growth of marine diatom.


Assuntos
Closterium , Diatomáceas , Poluentes Químicos da Água , Microplásticos , Dióxido de Silício/toxicidade , Dióxido de Silício/metabolismo , Plásticos , Poluentes Químicos da Água/metabolismo
19.
Sci China Life Sci ; 2023 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-38041781

RESUMO

Box C/D RNAs guide the site-specific formation of 2'-O-methylated nucleotides (Nm) of RNAs in eukaryotes and archaea. Although C/D RNAs have been profiled in several archaea, their targets have not been experimentally determined. Here, we mapped Nm in rRNAs, tRNAs, and abundant small RNAs (sRNAs) and profiled C/D RNAs in the crenarchaeon Sulfolobus islandicus. The targets of C/D RNAs were assigned by analysis of base-pairing interactions, in vitro modification assays, and gene deletion experiments, revealing a complicated landscape of C/D RNA-target interactions. C/D RNAs widely use dual antisense elements to target adjacent sites in rRNAs, enhancing modification at weakly bound sites. Two consecutive sites can be guided with the same antisense element upstream of box D or D', a phenomenon known as double-specificity that is exclusive to internal box D' in eukaryotic C/D RNAs. Several C/D RNAs guide modification at a single non-canonical site. This study reveals the global landscape of RNA-guided 2'-O-methylation in an archaeon and unexpected targeting rules employed by C/D RNA.

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