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1.
J Am Chem Soc ; 146(25): 17517-17529, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38869959

RESUMO

Despite the widespread use of hydrophilic building blocks to incorporate 18F and improve tracer pharmacokinetics, achieving effective leaving group-mediated nucleophilic 18F-fluorination in water (excluding 18F/19F-exchange) remains a formidable challenge. Here, we present a water-compatible SN2 leaving group-mediated 18F-fluorination method employing preconjugated "AquaF" (phosphonamidic fluorides) building blocks. Among 19 compact tetracoordinated pentavalent P(V)-F candidates, the "AquaF" building blocks exhibit superior water solubility, sufficient capacity for 18F-fluorination in water, and excellent in vivo metabolic properties. Two nitropyridinol leaving groups, identified from a pool of leaving group candidates that further enhance the precursor water solubility, enable 18F-fluorination in water with a 10-2 M-1 s-1 level reaction rate constant (surpassing the 18F/19F-exchange) at room temperature. With the exergonic concerted SN2 18F-fluorination mechanism confirmed, this 18F-fluorination method achieves ∼90% radiochemical conversions and reaches a molar activity of 175 ± 40 GBq/µmol (using 12.2 GBq initial activity) in saline for 12 "AquaF"-modified proof-of-concept functional substrates and small-molecule 18F-tracers. [18F]AquaF-Flurpiridaz demonstrates significantly improved radiochemical yield and molar activity compared to 18F-Flurpiridaz, alongside enhanced cardiac uptake and heart/liver ratio in targeted myocardial perfusion imaging, providing a comprehensive illustration of "AquaF" building blocks-assisted water-compatible SN2 18F-fluorination of small-molecule radiotracers.


Assuntos
Radioisótopos de Flúor , Halogenação , Água , Radioisótopos de Flúor/química , Água/química , Animais , Compostos Radiofarmacêuticos/química , Compostos Radiofarmacêuticos/síntese química , Camundongos , Tomografia por Emissão de Pósitrons , Solubilidade , Estrutura Molecular , Traçadores Radioativos
2.
Curr Issues Mol Biol ; 46(4): 3108-3121, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38666925

RESUMO

Farnesyl pyrophosphate synthase (FPPS) catalyzes the synthesis of C15 farnesyl diphosphate (FPP) from C5 dimethylallyl diphosphate (DMAPP) and two or three C5 isopentenyl diphosphates (IPPs). FPP is an important precursor for the synthesis of isoprenoids and is involved in multiple metabolic pathways. Here, farnesyl pyrophosphate synthase from Sporobolomyces pararoseus NGR (SpFPPS) was isolated and expressed by the prokaryotic expression system. The SpFPPS full-length genomic DNA and cDNA are 1566 bp and 1053 bp, respectively. This gene encodes a 350-amino acid protein with a predicted molecular mass of 40.33 kDa and a molecular weight of 58.03 kDa (40.33 kDa + 17.7 kDa), as detected by SDS-PAGE. The function of SpFPPS was identified by induction, purification, protein concentration and in vitro enzymatic activity experiments. Structural analysis showed that Y90 was essential for chain termination and changing the substrate scope. Site-directed mutation of Y90 to the smaller side-chain amino acids alanine (A) and lysine (K) showed in vitro that wt-SpFPPS catalyzed the condensation of the substrate DMAPP or geranyl diphosphate (GPP) with IPP at apparent saturation to synthesize FPP as the sole product and that the mutant protein SpFPPS-Y90A synthesized FPP and C20 geranylgeranyl diphosphate (GGPP), while SpFPPS-Y90K hydrolyzed the substrate GGPP. Our results showed that FPPS in S. pararoseus encodes the SpFPPS protein and that the amino acid substitution at Y90 changed the distribution of SpFPPS-catalyzed products. This provides a baseline for potentially regulating SpFPPS downstream products and improving the carotenoid biosynthesis pathway.

3.
Small ; 20(11): e2305120, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37926783

RESUMO

To reduce electromagnetic interference and noise pollution within communication base stations and servers, it is necessary for electromagnetic wave absorption (EWA) materials to transition from coating to multifunctional devices. Up to now, the stable and effective integration of multiple functions into one material by a simple method has remained a large challenge. Herein, a foam-type microwave absorption device assembled with multicomponent organic matter and graphite powder is synthesized by a universal combination process. Melamine and phenolic aldehyde amine work as the skeleton and cementing compound, respectively, in which graphite is embedded in the cementing compound interconnected into the mesoscopic 3D electric conductive and heat conductive network. Interestingly, the prepared flexible graphite/melamine foam (CMF) delivers a great EWA performance, with a great effective absorption bandwidth of 9.8 GHz, ultrathin thickness of 2.60 mm, and a strong absorption reflection loss of -41.7 dB. Moreover, the CMF possesses porosity and flexibility, endowing it with sound absorption ability. The CMF is unique in its integration of EWA, heat conduction, sound absorption, and mechanical robustness, as well as its cost-effective and scalable manufacturing. These attributes make CMF promising as a multifunctional device widely used in communication base stations, servers, and chips protection.

4.
Bioorg Med Chem Lett ; 109: 129818, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-38823726

RESUMO

Despite the availability of various 11C-labeled positron emission tomography (PET) tracers for assessing P-glycoprotein (P-gp) function, there are still limitations related to complex metabolism, high lipophilicity, and low baseline uptake. This study aimed to address these issues by exploring a series of customized dihydropyridines (DHPs) with enhanced stability and reduced lipophilicity as alternative PET tracers for P-gp dysfunction. Compared with verapamil and the rest DHPs, dimethyl 4-(4-fluorophenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate (1) exhibited superior cellular uptake differences between the human gastric cancer cell line SGC7901 and its drug-resistant counterpart. [18F]1 is successfully synthesized using a novel "hot-Hantzsch" approach in 22.1 ± 0.1 % radiochemical yields. MicroPET/CT imaging demonstrated that the uptake of [18F]1 in the brains of P-gp blocked mice increased by > 3 times compared to the control group. Additionally, [18F]1 displayed favorable lipophilicity (log D = 2.3) and excellent clearance characteristics, making it a promising tracer candidate with low background noise and high contrast.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP , Di-Hidropiridinas , Radioisótopos de Flúor , Tomografia por Emissão de Pósitrons , Di-Hidropiridinas/química , Di-Hidropiridinas/síntese química , Di-Hidropiridinas/farmacologia , Humanos , Animais , Radioisótopos de Flúor/química , Camundongos , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/antagonistas & inibidores , Linhagem Celular Tumoral , Estrutura Molecular , Compostos Radiofarmacêuticos/química , Compostos Radiofarmacêuticos/síntese química , Compostos Radiofarmacêuticos/farmacologia , Relação Estrutura-Atividade , Distribuição Tecidual
5.
BMC Microbiol ; 23(1): 170, 2023 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-37337195

RESUMO

BACKGROUND: Phages play a pivotal role in the evolution of microbial populations. The interactions between phages and their hosts are complex and may vary in response to host physiology and environmental conditions. Here, we have selected the genomes of some representative Bacillus prophages and lysosomes from the NCBI database for evolutionary analysis. We explored their evolutionary relationships and analyzed the protein information encoded by hundreds of Bacillus phages. RESULTS: We obtained the following conclusions: First, Bacillus phages carried some known functional gene fragments and a large number of unknown functional gene fragments, which might have an important impact on Bacillus populations, such as the formation of spores and biofilms and the transmission of virulence factors. Secondly, the Bacillus phage genome showed diversity, with a clear genome boundary between Bacillus prophages and Bacillus lytic phages. Furthermore, genetic mutations, sequence losses, duplications, and host-switching have occurred during the evolution of the Bacillus phage, resulting in low genome similarity between the Bacillus phages. Finally, the lysis module played an important influence on the process of Bacillus phage cross-species infestation. CONCLUSIONS: This study systematically described their protein function, diversity, and genome evolution, and the results of this study provide a basis for evolutionary diversity, horizontal gene transfer and co-evolution with the host in Bacillus phages.


Assuntos
Fagos Bacilares , Bacteriófagos , Fagos Bacilares/genética , Genoma Viral , Bacteriófagos/genética , Prófagos/genética , Mutação , Evolução Molecular
6.
Bioconjug Chem ; 34(1): 140-161, 2023 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-36594786

RESUMO

18F-Labeling methods for the preparation of 18F-labeled molecular probes can be classified into electrophilic fluorination, nucleophilic fluorination, metal-F coordination, and 18F/19F isotope exchange. Isotope exchange-based 18F-labeling methods demonstrate mild conditions featuring water resistance and facile high-performance liquid chromatography-free purification in direct 18F-labeling of substrates. This paper systematically reviews isotope exchange-based 18F-labeling methods sorted by the adjacent atom bonding with F, i.e., carbon and noncarbon atoms (Si, B, P, S, Ga, Fe, etc.). The respective isotope exchange mechanism, radiolabeling condition, radiochemical yield, molar activity, and stability of the 18F-product are mainly discussed for each isotope exchange-based 18F-labeling method as well as the cutting-edge application of the corresponding 18F-labeled molecular probes.


Assuntos
Halogenação , Água , Sondas Moleculares , Marcação por Isótopo/métodos , Radioisótopos de Flúor/química , Compostos Radiofarmacêuticos/química
7.
Microvasc Res ; 150: 104586, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37451332

RESUMO

PURPOSE: To compare long-term real-world outcomes of retinal microvasculature changes in proliferative diabetic retinopathy (PDR) treated with panretinal photocoagulation (PRP) vs. intravitreal conbercept (IVC) and to explore the potential factors affecting these changes. METHODS: This study retrospectively included 96 treatment-naïve PDR eyes of 96 type 2 diabetes mellitus patients [59 PRP and 37 IVC]. Baseline characteristics and treatment details were collected. Optical coherence tomography angiography (OCTA) data of macular vessel density (VD) and optic disc capillary density (CD) at baseline and at the last follow-up were compared between groups. The differences between the baseline and the last follow-up OCTA data in each group were also tested for significance. The correlation between the change in each OCTA parameter from baseline and each baseline characteristic/treatment parameter was investigated in each group. RESULTS: During a mean follow-up of two years, greater superficial (SCP) (p = 0.004) and deep capillary plexus (DCP) VD (p < 0.001) were observed in the foveal area in the PRP than in the IVC. Compared to the baseline, SCP VD in the foveal area increased in the PRP (p = 0.012), while an increased SCP VD in some sectors in the parafoveal and perifoveal areas (p < 0.05), rather than the foveal area (p = 0.908), was seen in the IVC. For both groups, eyes with a higher VD/CD at baseline tended to develop capillary dropout more intensively (all p < 0.05). In the IVC group, foveal avascular zone (FAZ) area change showed a negative correlation with baseline FAZ area (p = 0.020), and complementary PRP exerted a negative influence on FAZ area change (p = 0.002). In the PRP group, SCP VD change was positively correlated with follow-up frequency, and was negatively correlated with diastolic blood pressure (all p < 0.05); DCP VD change showed a positive correlation with PRP shot number (p = 0.019). CONCLUSION: The aforementioned microvasculature changes should be considered when PRP or IVC is adopted in PDR long-term management.


Assuntos
Diabetes Mellitus Tipo 2 , Retinopatia Diabética , Humanos , Retinopatia Diabética/diagnóstico , Retinopatia Diabética/terapia , Vasos Retinianos/diagnóstico por imagem , Angiofluoresceinografia/métodos , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/diagnóstico , Estudos Retrospectivos , Retina , Tomografia de Coerência Óptica/métodos , Microvasos/diagnóstico por imagem , Fotocoagulação
8.
Chemistry ; 29(37): e202300248, 2023 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-37102671

RESUMO

18 F-Labeled molecular tracers and subsequent positron emission tomography are indispensable molecular imaging tools in medical diagnosis and research. The preparation of 18 F-labeled molecular tracers involves critical steps such as the 18 F-labeling reaction, work-up, and 18 F-product purification, which are governed by 18 F-labeling chemistry. Since direct incorporation of 18 F in aqueous media exhibits many advantages in practice, this Review summarizes the existing 18 F-labeling methods in aqueous media, which are sorted by atoms forming chemical covalent bonds with F. The Review is focused on the respective reaction mechanism, the water effect and the applications of these methods for the development of 18 F-radiopharmaceuticals. The research progress on aqueous nucleophilic labeling methods using [18 F]F- as the 18 F source has been mainly discussed.

9.
Langmuir ; 39(26): 9007-9016, 2023 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-37329319

RESUMO

Radiochemical yields (RCYs) of isotope exchange-based 18F-fluorination of non-carbon-centered substrates in water are rationally enhanced by adding surfactants, which increases both the rate constant k and local reactant concentrations. Among 12 surfactants, the cationic surfactant cetrimonium bromide (CTAB) and two nonionic surfactants (Tween 20 and Tween 80) were selected for their superior catalytic effects, namely, electrostatic effects or solubilization effects. For a model substrate, bis(4-methoxyphenyl)phosphinic fluoride, the 18F-fluorination rate constant (k) increased up to 7-fold, while its saturation concentration rose up to 15-fold due to micelle formation, encapsulating 70-94% of the substrate. With 30.0 mmol/L CTAB, the required 18F-labeling temperature of a typical organofluorosilicon prosthesis ([18F]SiFA) decreased from 95 °C to room temperature, achieving an RCY of 22%. For an E[c(RGDyK)]2-derived peptide tracer with an organofluorophosphine prosthesis, the RCY in water at 90 °C achieved 25%, correspondingly increasing the molar activity (Am). After high-performance liquid chromatography (HPLC) or solid-phase purification, the residual selected surfactant concentrations in the tracer injections were well below the FDA DII (Inactive Ingredient Database) limits or the LD50 in mice.

10.
Appl Microbiol Biotechnol ; 107(22): 6761-6773, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37698607

RESUMO

Pullulan is a polymer produced by Aureobasidium spp. The yield of pullulan production can be impacted by the cellular differentiation of Aureobasidium spp., which changes with alterations in the growth environment. To improve pullulan yield, identifying key factors that regulate cellular differentiation is crucial. In this study, the main form of pullulan synthesis in Aureobasidium pullulans NG was through swollen cells (SC). The results showed that citric acid (CA) can regulate the cellular differentiation of Aureobasidium pullulans NG by accumulating higher levels of CA in the cells to maintain growth in SC form and increase pullulan production. The addition of 1.0% CA to Aureobasidium pullulans NG for 96 h resulted in a significant increase in pullulan production, producing 18.32 g/l compared to the control group which produced 10.23 g/l. Our findings suggest that controlling cellular differentiation using CA is a promising approach for enhancing pullulan production in Aureobasidium pullulans. KEY POINTS: • The regulation of cell differentiation in Aureobasidium pullulans NG is demonstrated to be influenced by citric acid. • Intracellular citric acid levels in Aureobasidium pullulans NG have been shown to support the growth of swollen cells. • Citric acid has been found to increase pullulan production in Aureobasidium pullulans NG.

11.
BMC Ophthalmol ; 23(1): 28, 2023 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-36690959

RESUMO

OBJECTIVE: To develop and validate a nomogram model for predicting chronic ocular graft-versus-host disease (coGVHD) in patients after allogenic haematopoietic stem cell transplantation (allo-HSCT). METHODS: This study included 61 patients who survived at least 100 days after allo-HSCT. Risk factors for coGVHD were screened using LASSO regression, then the variables selected were subjected to logistic regression. Nomogram was established to further confirm the risk factors for coGVHD. Receiver operating characteristic (ROC) curves were constructed to assess the performance of the predictive model with the training and test sets. Odds ratios and 95% confidence intervals (95% CIs) were calculated by using logistic regression analysis. RESULTS: Among the 61 patients, 38 were diagnosed with coGVHD. We selected five texture features: lymphocytes (LYM) (OR = 2.26), plasma thromboplastin antecedent (PTA) (OR = 1.19), CD3 + CD25 + cells (OR = 1.38), CD3 + HLA-DR + cells (OR = 0.95), and the ocular surface disease index (OSDI) (OR = 1.44). The areas under the ROC curve (AUCs) of the nomogram with the training and test sets were 0.979 (95% CI, 0.895-1.000) and 0.969 (95% CI, 0.846-1.000), respectively.And the Hosmer-Lemeshow test was nonsignificant with the training (p = 0.9949) and test sets (p = 0.9691). CONCLUSION: We constructed a nomogram that can assess the risk of coGVHD in patients after allo-HSCT and help minimize the irreversible loss of vision caused by the disease in high-risk populations.


Assuntos
Doença Enxerto-Hospedeiro , Transplante de Células-Tronco Hematopoéticas , Humanos , Nomogramas , Transplante Homólogo/efeitos adversos , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Doença Enxerto-Hospedeiro/etiologia , Fatores de Risco
12.
Int J Mol Sci ; 24(3)2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36769154

RESUMO

In the traditional method of the bio-fabrication of zinc oxide nanoparticles (ZnONPs), bacterial strains face metal toxicity and antimicrobial action. In the current study, an alkalescent nucleoside antibiotic was mixed with zinc hexanitrate to fabricate the ZnONPs. An integrated approach of DIAION HP-20 macroporous resin and sephadex LH-20 column chromatography was adopted to separate and purify alkalescent nucleoside AN03 from Streptomyces koyanogensis. Alkalescent nucleoside was confirmed by the Doskochilova solvent system. The bio-fabricated ZnONPs were characterized by using Fourier transform infrared (FTIR), X-ray diffraction (XRD), and transmission electron microscopy (TEM) analyses. The XRD spectrum and the TEM images confirmed the crystallinity and the spherical shape of the ZnONPs with an average size of 22 nm. FTIR analysis showed the presence of functional groups, which confirmed the bio-fabrication of ZnONPs from alkalescent nucleoside ANO3. In-vitro studies showed that 75 µg/mL of ZnONPs had a strong inhibitory zone (28.39 mm) against the Magnaporthe grisea and significantly suppressed the spore germination. SEM and TEM observations respectively revealed that ZnONPs caused breakage in hyphae and could damage the cells of M. grisea. Greenhouse experiments revealed that the foliar spray of ZnONPs could control the rice blast disease by 98%. Results also revealed that ZnONPs had positive effects on the growth of the rice plant. The present study suggested that ZnONPs could be fabricated from microbe-derived nucleoside antibiotics without facing the problems of metal toxicity and antimicrobial action, thus overcoming the problem of pathogen resistance. This could be a potent biocontrol agent in rice blast disease management.


Assuntos
Magnaporthe , Nanopartículas , Oryza , Óxido de Zinco , Antibacterianos/farmacologia , Antibacterianos/química , Óxido de Zinco/química , Nucleosídeos/farmacologia , Pyricularia grisea , Nanopartículas/química , Oryza/microbiologia
13.
Int J Mol Sci ; 24(21)2023 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-37958506

RESUMO

Nicotine-induced endoplasmic reticulum (ER) stress in retinal pigment epithelium (RPE) cells is thought to be one pathological mechanism underlying age-related macular degeneration (AMD). ERp29 attenuates tobacco extract-induced ER stress and mitigates tight junction damage in RPE cells. Herein, we aimed to further investigate the role of ERp29 in nicotine-induced ER stress and choroidal neovascularization (CNV). We found that the expression of ERp29 and GRP78 in ARPE-19 cells was increased in response to nicotine exposure. Overexpression of ERp29 decreased the levels of GRP78 and the C/EBP homologous protein (CHOP). Knockdown of ERp29 increased the levels of GRP78 and CHOP while reducing the viability of ARPE-19 cells under nicotine exposure conditions. In the ARPE-19 cell/macrophage coculture system, overexpression of ERp29 decreased the levels of M2 markers and increased the levels of M1 markers. The viability, migration and tube formation of human umbilical vein endothelial cells (HUVECs) were inhibited by conditioned medium from the ERp29-overexpressing group. Moreover, overexpression of ERp29 inhibits the activity and growth of CNV in mice exposed to nicotine in vivo. Taken together, our results revealed that ERp29 attenuated nicotine-induced ER stress, regulated macrophage polarization and inhibited CNV.


Assuntos
Neovascularização de Coroide , Nicotina , Animais , Humanos , Camundongos , Neovascularização de Coroide/genética , Neovascularização de Coroide/metabolismo , Chaperona BiP do Retículo Endoplasmático , Estresse do Retículo Endoplasmático , Células Endoteliais da Veia Umbilical Humana/patologia , Nicotina/farmacologia , Epitélio Pigmentado da Retina/metabolismo , Proteínas de Choque Térmico/metabolismo
14.
Molecules ; 28(7)2023 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-37050023

RESUMO

The common mycotoxins in polluted grains are aflatoxin B1(AFB1), zearalenone (ZEN) and deoxynivalenol (DON). Because of the potential threat to humans and animals, it is necessary to detect mycotoxin contaminants rapidly. At present, later flow immunoassay (LFIA) is one of the most frequently used methods for rapid analysis. However, multistep sample pretreatment processes and organic solvents are also required to extract mycotoxins from grains. In this study, we developed a one-step and "green" sample pretreatment method without using organic solvents. By combining with LFIA test strips and a handheld detection device, an on-site method for the rapid detection of AFB1, ZEN and DON was developed. The LODs for AFB1, ZEN and DON in corn are 0.90 µg/kg, 7.11 µg/kg and 10.6 µg/kg, respectively, and the working ranges are from 1.25 µg/kg to 40 µg/kg, 20 µg/kg to 2000 µg/kg and 35 µg/kg to 1500 µg/kg, respectively. This method has been successfully applied to the detection of AFB1, ZEN and DON in corn, rice and peanut, with recoveries of 89 ± 3%-106 ± 3%, 86 ± 2%-108 ± 7% and 90 ± 2%-106 ± 10%, respectively. The detection results for the AFB1, ZEN and DON residues in certified reference materials by this method were in good agreement with their certificate values.


Assuntos
Micotoxinas , Oryza , Zearalenona , Animais , Humanos , Arachis , Aflatoxina B1 , Zea mays , Micotoxinas/análise , Contaminação de Alimentos/análise
15.
Environ Geochem Health ; 45(8): 6177-6198, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37269417

RESUMO

Metal mineral mining results in releases of large amounts of heavy metals into the environment, and it is necessary to better understand the response of rhizosphere microbial communities to simultaneous stress from multiple heavy metals (HMs), which directly impacts plant growth and human health. In this study, by adding different concentrations of cadmium (Cd) to a soil with high background concentrations of vanadium (V) and chromium (Cr), the growth of maize during the jointing stage was explored under limiting conditions. High-throughput sequencing was used to explore the response and survival strategies of rhizosphere soil microbial communities to complex HM stress. The results showed that complex HMs inhibited the growth of maize at the jointing stage, and the diversity and abundance of maize rhizosphere soil microorganisms were significantly different at different metal enrichment levels. In addition, according to the different stress levels, the maize rhizosphere attracted many tolerant colonizing bacteria, and cooccurrence network analysis showed that these bacteria interacted very closely. The effects of residual heavy metals on beneficial microorganisms (such as Xanthomonas, Sphingomonas, and lysozyme) were significantly stronger than those of bioavailable metals and soil physical and chemical properties. PICRUSt analysis revealed that the different forms of V and Cd had significantly greater effects on microbial metabolic pathways than all forms of Cr. Cr mainly affected the two major metabolic pathways: microbial cell growth and division and environmental information transmission. In addition, significant differences in rhizosphere microbial metabolism under different concentrations were found, and this can serve as a reference for subsequent metagenomic analysis. This study is helpful for exploring the threshold for the growth of crops in toxic HM soils in mining areas and achieving further biological remediation.


Assuntos
Metais Pesados , Microbiota , Poluentes do Solo , Humanos , Cádmio/análise , Rizosfera , Metais Pesados/análise , Solo/química , Zea mays/metabolismo , Poluentes do Solo/análise , Microbiologia do Solo
16.
J Neurochem ; 163(4): 310-326, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35775994

RESUMO

GABAergic network activity has been established to be involved in numerous physiological processes and pathological conditions. Extensive studies have corroborated that GABAergic network activity regulates excitatory synaptic networks by activating presynaptic GABAB receptors (GABAB Rs). It is well documented that astrocytes express GABAB Rs and respond to GABAergic network activity. However, little is known about whether astrocytic GABAB Rs regulate excitatory synaptic transmission mediated by GABAergic network activity. To address this issue, we combined whole-cell recordings, optogenetics, calcium imaging, and pharmacological approaches to specifically activate hippocampal somatostatin-expressing interneurons (SOM-INs), a type of interneuron that targets pyramidal cell dendrites, while monitoring excitatory synaptic transmission in CA1 pyramidal cells. We found that optogenetic stimulation of SOM-INs increases astrocyte Ca2+ signaling via the activation of astrocytic GABAB Rs and GAT-3. SOM-INs depress excitatory neurotransmission by activating presynaptic GABAB Rs and astrocytic GABAB Rs, the latter inducing the release of ATP/adenosine. In turn, adenosine inhibits excitatory synaptic transmission by activating presynaptic adenosine A1 receptors (A1 Rs). Overall, our results reveal a novel mechanism that SOM-INs activation-induced synaptic depression is partially mediated by the activation of astrocytic GABAB Rs.


Assuntos
Astrócitos , Interneurônios , Astrócitos/metabolismo , Interneurônios/metabolismo , Hipocampo/metabolismo , Transmissão Sináptica/fisiologia , Somatostatina , Receptores de GABA-B/fisiologia , Receptores Purinérgicos P1/metabolismo , Ácido gama-Aminobutírico/metabolismo , Adenosina/metabolismo
17.
Bioconjug Chem ; 33(5): 749-766, 2022 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-35467335

RESUMO

Reactive oxygen species (ROS) are a cluster of highly reactive and short-lived oxygen-containing molecules that lead to metabolic disorders where production exceeds catabolism in an organism. Many specific radiotracers for positron/single-photon emission tomography have been developed to reveal the discrepancy of ROS levels in normal and damaged tissues and further clarify the relationship between ROS and diseases. This review summarizes the advances achieved for the development of ROS radiotracers to date. The structure design, radiosynthesis, and imaging performance of existing radiotracers are discussed with the individual ROS-response mechanisms highlighted.


Assuntos
Diagnóstico por Imagem , Espécies Reativas de Oxigênio/metabolismo
18.
J Org Chem ; 87(22): 15661-15669, 2022 11 18.
Artigo em Inglês | MEDLINE | ID: mdl-36317696

RESUMO

By employing Cu(CH3CN)4PF6 as the catalyst and tert-butyl hydroperoxide as the oxidant, we realized a three-component radical selenosulfonation of substituted maleimides, sulfonyl hydrazides, and diphenyl diselenides, providing a series of 3,4-selenosulfonylated succinimides in moderate to good yields. This reaction features broad substrate scopes, high functional-group tolerability, and feasibility of gram-scale synthesis, enabling one-step construction of C-SO2 and C-Se bonds under mild reaction conditions. Preliminary mechanistic studies support the free-radical-induced pathway.


Assuntos
Cobre , Iodo , Cobre/química , Maleimidas , Estrutura Molecular , Hidrazinas/química , Catálise
19.
Clin Chem Lab Med ; 60(8): 1299-1307, 2022 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-35567358

RESUMO

OBJECTIVES: To validate the analytical performance and diagnostic accuracy for non-ST-segment elevation myocardial infarction (NSTEMI) with a new high-sensitivity cardiac troponin I (hs-cTnI) assay on the automated light-initiated chemiluminescent assay (LiCA®) platform. METHODS: Comprehensive analytical validations were performed, and the 99th percentile upper reference limit (URL) from apparently healthy individuals were established. We evaluated the diagnostic performance of the assay for NSTEMI. RESULTS: The limit of quantitation (LoQ) were 1.9 ng/L (20% CV) and 5.1 ng/L (10% CV). The sex-specific 99th percentile URLs were 17.6 ng/L (4.2% CV) for men (age 20-79y) and 14.2 ng/L (4.9% CV) for women (age 19-89y) in serum, 14.4 ng/L (4.9% CV) for men (age 19-88y) and 12.9 ng/L (5.2% CV) for women (age 19-87y) in plasma, respectively. Detection rates in healthy individuals were from 98.7 to 99.1%. The correlation coefficient and median bias between LiCA and Architect were 0.985 and 0.1% (-2.0-2.9%) in full analytical range of serum specimens. In lower range (<100 ng/L), LiCA had an overall positive bias 6.7% (-1.6-13.3%), R=0.949. At the specific medical decision levels (15.2, 26.2 and 64.0 ng/L), assay difference was estimated to be <10%. No significant differences on AUC, sensitivity and specificity, NPV and PPV were found between LiCA and Architect for the diagnosis of NSTEMI. CONCLUSIONS: LiCA hs-cTnI is a precise, highly sensitive and specific assay that meets the requirement of a 3rd generation (level 4) high-sensitivity method. The diagnostic accuracy of LiCA assay for NSTEMI is comparable to the established Architect hs-cTnI assay.


Assuntos
Infarto do Miocárdio sem Supradesnível do Segmento ST , Troponina I , Adulto , Idoso , Idoso de 80 Anos ou mais , Bioensaio , Biomarcadores , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio sem Supradesnível do Segmento ST/diagnóstico , Sensibilidade e Especificidade , Troponina T , Adulto Jovem
20.
J Chem Phys ; 157(18): 184501, 2022 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-36379776

RESUMO

We investigated the stretched dynamics of the structural relaxation in molecular glass formers by using dielectric and thermal (or enthalpic) relaxations. The dielectric stretching exponents ßdie are determined by the Havriliak-Negami function, while the enthalpic ßTNMH is quantified by using the Tool-Narayanaswamy-Moynihan-Hodge formalism. We found ßTNMH is anticorrelated with the degree of freedom, a molecule addressed by the concept of beads. Referring to the reported relation of ßdie to the dipole moment µ, we proposed a combined parameter of µ2*beads, which can rationalize the difference in stretching exponents obtained by dielectric and enthalpic relaxations. For the majority of glass-forming molecules, the difference is trivial, but for those molecules with both unusually high dipole moments and flexibility, a large difference is obvious. The interplay of the degree of freedom and dielectric dipole-dipole interaction in molecular dynamics is addressed.

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