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1.
BMC Plant Biol ; 24(1): 817, 2024 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-39210248

RESUMO

BACKGROUND: Astragalus cicer L. is a perennial rhizomatous legume forage known for its quality, high biomass yield, and strong tolerance to saline-alkaline soils. Soil salinization is a widespread environmental pressure. To use A. cicer L. more scientifically and environmentally in agriculture and ecosystems, it is highly important to study the molecular response mechanism of A. cicer L. to salt stress. RESULTS: In this study, we used RNA-seq technology and weighted gene coexpression network analysis (WGCNA) were performed. The results showed 4 key modules were closely related to the physiological response of A. cicer. L. to salt stress. The differentially expressed genes (DEGs) of key modules were mapped into the KEGG database, and found that the most abundant pathways were the plant hormone signal transduction pathway and carbon metabolism pathway. The potential regulatory networks of the cytokinin signal transduction pathway, the ethylene signal transduction pathway, and carbon metabolism related pathways were constructed according to the expression pathways of the DEGs. Seven hub genes in the key modules were selected and distributed among these pathways. They may involved in the positive regulation of cytokinin signaling and carbon metabolism in plant leaves, but limited the positive expression of ethylene signaling. Thus endowing the plant with salt tolerance in the early stage of salt stress. CONCLUSIONS: Based on the phenotypic and physiological responses of A. cicer L. to salt stress, this study constructed the gene coexpression network of potential regulation to salt stress in key modules, which provided a new reference for exploring the response mechanism of legumes to abiotic stress.


Assuntos
Astrágalo , Regulação da Expressão Gênica de Plantas , Redes Reguladoras de Genes , Estresse Salino , Transcriptoma , Estresse Salino/genética , Astrágalo/genética , Astrágalo/fisiologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Perfilação da Expressão Gênica , Reguladores de Crescimento de Plantas/farmacologia , Reguladores de Crescimento de Plantas/metabolismo
2.
Sensors (Basel) ; 24(19)2024 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-39409403

RESUMO

Cellular heterogeneity plays a significant role in understanding biological processes, such as cell cycle and disease progression. Microfluidics has emerged as a versatile tool for manipulating single cells and analyzing their heterogeneity with the merits of precise fluid control, small sample consumption, easy integration, and high throughput. Specifically, integrating microfluidics with electrical techniques provides a rapid, label-free, and non-invasive way to investigate cellular heterogeneity at the single-cell level. Here, we review the recent development of microfluidic-based electrical strategies for single-cell manipulation and analysis, including dielectrophoresis- and electroporation-based single-cell manipulation, impedance- and AC electrokinetic-based methods, and electrochemical-based single-cell detection methods. Finally, the challenges and future perspectives of the microfluidic-based electrical techniques for single-cell analysis are proposed.


Assuntos
Análise de Célula Única , Análise de Célula Única/métodos , Humanos , Microfluídica/métodos , Técnicas Analíticas Microfluídicas/métodos , Técnicas Analíticas Microfluídicas/instrumentação , Eletroporação/métodos , Técnicas Eletroquímicas/métodos , Técnicas Eletroquímicas/instrumentação , Animais
3.
Nano Lett ; 23(14): 6323-6329, 2023 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-37459426

RESUMO

There remains continued interest in improving the advanced water oxidation process [e.g., ultraviolet (UV)/hydrogen peroxide (H2O2)] for more efficient and environmentally friendly wastewater treatment. Here, we report the design, fabrication, and performance of graphene oxide (GO, on top)/nickel-doped iron oxyhydroxide (Ni:FeOOH, shell)/silicon nanowires (SiNWs, core) as a new multifunctional photocatalyst for the degradation of common pollutants like polystyrene and methylene blue through enhancing the hydroxyl radical (•OH) production rate of the UV/H2O2 system. The photocatalyst combines the advantages of a large surface area and light absorption characteristics of SiNWs with heterogeneous photo-Fenton active Ni:FeOOH and photocatalytically active/charge separator GO. In addition, the built-in electric field of GO/Ni:FeOOH/SiNWs facilitates the charge separation of electrons to GO and holes to Ni:FeOOH, thus boosting the photocatalytic performance. Our photocatalyst increases the •OH yield by 5.7 times compared with that of a blank H2O2 solution sample and also extends the light absorption spectrum to include visible light irradiation.

4.
Nano Lett ; 23(17): 7968-7974, 2023 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-37656036

RESUMO

Magnesium diboride (MgB2) has been explored as an alternative fuel to boron (B) due to its high energy density and the additive effect of magnesium (Mg) to promote B combustion. However, the primary oxidation of MgB2 does not occur unless it decomposes at a high temperature (830 °C), which makes ignition difficult and the reaction slow. Recently, two-dimensional (2D) exfoliated MgB2 nanosheets have attracted increasing attention due to their unique properties and potential applications in various fields. In this study, we investigate the potential of 2D exfoliated MgB2 nanosheets as solid fuels for overcoming the challenges of MgB2 combustion. We analyzed their oxidation behavior and energetic performance through material characterization and combustion tests under slow- and fast-heating conditions and compared their performance with those of bulk MgB2, B nanoparticles, and a B/Mg nanoparticle mixture. This study highlights the potential of MgB2 nanosheets as promising solid fuels with superior energetic properties.

5.
Surg Endosc ; 37(2): 1334-1341, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36203107

RESUMO

BACKGROUND: Laparoscopic right posterior sectionectomy (LRPS) was technically challenging and lack of standardization. There were some approaches for LRPS, such as caudal approach and dorsal approach. During our practice, we initiated pure LRPS using the caudodorsal approach with in situ split and present several advantages of this method. METHODS: From April 2018 to December 2021, consecutive patients who underwent pure LRPS using the caudodorsal approach with in situ split at our institution entered into this retrospective study. The key point of the caudodorsal approach was that the right hepatic vein was exposed from peripheral branches toward the root and the parenchyma was transected from the dorsal side to ventral side. Specially, the right perihepatic ligaments were not divided to keep the right liver in situ before parenchymal dissection for each case. RESULTS: 11 patients underwent pure LRPS using the caudodorsal approach with in situ split. There were 9 hepatocellular carcinoma, 1 sarcomatoid hepatocellular carcinoma, and 1 hepatic hemangioma. Five patients had mild cirrhosis and 1 had moderate cirrhosis. All the procedures were successfully completed laparoscopically. The median operative time was 375 min (range of 290-505 min) and the median blood loss was 300 ml (range of 100-1000 ml). Five patients received perioperative blood transfusion, of which 1 patient received autologous blood transfusion and 2 patients received blood transfusion due to preoperative moderate anemia. No procedure was converted to open surgery. Two patients who suffered from postoperative complications, improved after conservative treatments. The median postoperative stay was 11 days (range of 7-25 days). No postoperative bleeding, hepatic failure, and mortality occurred. CONCLUSION: The preliminary clinical effect of the caudodorsal approach with in situ split for LRPS was satisfactory. Our method was feasible and expected to provide ideas for the standardization of LRPS. Further researches are required due to some limitations of this study.


Assuntos
Carcinoma Hepatocelular , Laparoscopia , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/cirurgia , Estudos Retrospectivos , Hepatectomia/métodos , Neoplasias Hepáticas/cirurgia , Laparoscopia/métodos , Duração da Cirurgia
6.
J Clin Ultrasound ; 51(1): 195-202, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36539919

RESUMO

OBJECTIVE: Thyroid cancer (TC) is an extremely prevailing malignant endocrine tumor. Therefore, effective diagnostic tools are necessary. This study explored the application value of dual-source computed tomography (DSCT) in TC diagnosis and biological behavior assessment. METHODS: This study retrospectively selected 68 TC patients and another 74 benign patients with thyroid adenoma, nodular goiter, or adenomatous hyperplasia. All patients were confirmed by pathological examination and underwent DSCT examination. The iodine concentration (IC) obtained from plain computed tomography (CT) scanning and normalized iodine concentration (NIC) in the arterial phase and venous phase were recorded. The positive expression rates of estrogen receptor alpha (ERα), estrogen receptors beta (ERß), and Ki67 in pathological tissues were determined by immunohistochemistry, and their correlation with IC in plain CT was assessed by Pearson correlation analysis, respectively. The diagnostic values of IC in plain CT and venous phase NIC in TC patients were evaluated using the receiver operating characteristic curve. RESULTS: Malignant patients had lower IC in plain DSCT scanning, venous phase NIC, and ERß, and higher ERα and Ki67 than benign patients. IC level in plain DSCT scanning was inversely-correlated with ERα and Ki-67 positive expression rates, but positively-related to ERß to different degrees. For the diagnosis of TC patients, the AUC of IC level in plain DSCT was 0.771, with a cut-off value of 1.250 (97.06% sensitivity and 41.89% specificity), and the AUC of venous phase NIC was 0.738, with a cut-off value of 0.825 (100% sensitivity and 43.24% specificity). CONCLUSION: The IC level obtained from DSCT scanning could assist in the differential diagnosis of malignant and benign thyroid nodules and evaluation of biological behaviors.


Assuntos
Iodo , Neoplasias da Glândula Tireoide , Humanos , Receptor alfa de Estrogênio , Estudos Retrospectivos , Receptor beta de Estrogênio , Antígeno Ki-67 , Tomografia Computadorizada por Raios X/métodos , Neoplasias da Glândula Tireoide/diagnóstico por imagem , Diagnóstico Diferencial , Iodo/análise
7.
Plant J ; 103(4): 1318-1337, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32391615

RESUMO

Papaya (Carica papaya L.) is a commercially important fruit crop. Various phytohormones, particularly ethylene and auxin, control papaya fruit ripening. However, little is known about the interaction between auxin and ethylene signaling during the fruit ripening process. In the present study, we determined that the interaction between the CpARF2 and CpEIL1 mediates the interaction between auxin and ethylene signaling to regulate fruit ripening in papaya. We identified the ethylene-induced auxin response factor CpARF2 and demonstrated that it is essential for fruit ripening in papaya. CpARF2 interacts with an important ethylene signal transcription factor CpEIL1, thus increasing the CpEIL1-mediated transcription of the fruit ripening-associated genes CpACS1, CpACO1, CpXTH12 and CpPE51. Moreover, CpEIL1 is ubiquitinated by CpEBF1 and is degraded through the 26S proteasome pathway. However, CpARF2 weakens the CpEBF1-CpEIL1 interaction and interferes with CpEBF1-mediated degradation of CpEIL1, promoting fruit ripening. Therefore, CpARF2 functions as an integrator in the auxin-ethylene interaction and regulates fruit ripening by stabilizing CpEIL1 protein and promoting the transcriptional activity of CpEIL1. To our knowledge, we have revealed a novel module of CpARF2/CpEIL1/CpEBF1 that fine-tune fruit ripening in papaya. Manipulating this mechanism could help growers tightly control papaya fruit ripening and prolong shelf life.


Assuntos
Carica/metabolismo , Etilenos/metabolismo , Frutas/metabolismo , Ácidos Indolacéticos/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Proteínas de Plantas/fisiologia , Fatores de Transcrição/fisiologia , Carica/crescimento & desenvolvimento , Frutas/crescimento & desenvolvimento , Filogenia , Proteínas de Plantas/metabolismo , Fatores de Transcrição/metabolismo
8.
J Interv Cardiol ; 2021: 2632343, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34934407

RESUMO

BACKGROUND: The revascularization of small vessels using drug-eluting stents remains challenging. The use of the drug-coated balloon is an attractive therapeutic strategy in de novo lesions in small coronary vessels, particularly in the diabetic group. This study aimed to assess the outcomes of DCB-only angioplasty in small vessel disease. METHODS: A total of 1198 patients with small vessel disease treated with DCB-only strategy were followed. Patients were divided into the diabetic and nondiabetic groups. Clinical and angiographical follow-up were organized at 12 months. The primary endpoints were target lesion failure and secondary major adverse cardiac events. RESULTS: There was a significantly higher rate of target lesion failure among diabetic patients compared to nondiabetic [17 (3.9%) vs. 11 (1.4%), P=0.006], taken separately, the rate of target lesion revascularization significantly differed between groups with a higher rate observed in the diabetic group [9 (2%) vs. 4 (0.5%), P=0.014]. Diabetes mellitus remained an independent predictor for TLF (HR: 2.712, CI: 1.254-5.864, P=0.011) and target lesion revascularization (HR: 3.698, CI: 1.112-12.298, P=0.033) after adjustment. However, no significant differences were observed between groups regarding the target vessel myocardial infarction (0.6% vs. 0.1%, P=0.110) and MACE [19 (4.4%) vs. 21 (2.7%), P=0.120]. CONCLUSION: Drug-coated balloon-only treatment achieved lower incidence rates of TLF and MACE. Diabetes is an independent predictor for target lesion failure and target lesion revascularization at one year following DCB treatment in small coronary vessels. We observed no significant differences between groups regarding MACE in one year.


Assuntos
Angioplastia Coronária com Balão , Doença da Artéria Coronariana , Diabetes Mellitus , Preparações Farmacêuticas , Angiografia Coronária , Doença da Artéria Coronariana/cirurgia , Vasos Coronários/diagnóstico por imagem , Vasos Coronários/cirurgia , Diabetes Mellitus/epidemiologia , Humanos , Resultado do Tratamento
9.
Proc Natl Acad Sci U S A ; 115(31): E7236-E7244, 2018 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-30012591

RESUMO

Transfer printing of thin-film nanoelectronics from their fabrication wafer commonly requires chemical etching on the sacrifice of wafer but is also limited by defects with a low yield. Here, we introduce a wafer-recyclable, environment-friendly transfer printing process that enables the wafer-scale separation of high-performance thin-film nanoelectronics from their fabrication wafer in a defect-free manner that enables multiple reuses of the wafer. The interfacial delamination is enabled through a controllable cracking phenomenon in a water environment at room temperature. The physically liberated thin-film nanoelectronics can be then pasted onto arbitrary places of interest, thereby endowing the particular surface with desirable add-on electronic features. Systematic experimental, theoretical, and computational studies reveal the underlying mechanics mechanism and guide manufacturability for the transfer printing process in terms of scalability, controllability, and reproducibility.

10.
J Sci Food Agric ; 101(8): 3176-3185, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33211342

RESUMO

BACKGROUND: Plums tend to experience a reduction in fruit quality due to ripening and they deteriorate quickly during storage at room temperature. Benzothiadiazole (BTH) is a plant elicitor capable of inducing disease resistance in many crops. In this study, the effect of BTH treatment on fruit ripening, fruit quality, and anthocyanin biosynthesis in 'Taoxingli' plum was investigated. RESULTS: The results showed that BTH treatment could accelerate fruit ripening without affecting the incidence of fruit decay or the shelf life. Benzothiadiazole treatment improved the quality and consumer acceptability of 'Taoxingli' plums during storage by increasing the sweetness, red color formation, and the concentration of healthy antioxidant compounds. The BTH treatment could also effectively promote the biosynthesis of anthocyanin by enhancing the enzyme activities of phenylalanine ammonia-lyase (PAL), dihydroflavonol 4-reductase (DFR), anthocyanidin synthase (ANS), and uridine diphosphate flavonoid 3-O-glucosyltransferase (UFGT) and up-regulating the gene expressions of PsPAL, PsCHI, PsDFR, PsANS, and PsUFGT during storage. CONCLUSION: Benzothiadiazole treatment could be a potential postharvest technology for improving fruit quality and consumer acceptability in harvested plum fruit. © 2020 Society of Chemical Industry.


Assuntos
Antocianinas/biossíntese , Conservação de Alimentos/métodos , Conservantes de Alimentos/farmacologia , Frutas/química , Prunus domestica/efeitos dos fármacos , Tiadiazóis/farmacologia , Armazenamento de Alimentos , Frutas/efeitos dos fármacos , Frutas/genética , Frutas/metabolismo , Oxigenases/genética , Oxigenases/metabolismo , Fenilalanina Amônia-Liase/genética , Fenilalanina Amônia-Liase/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Prunus domestica/química , Prunus domestica/genética , Prunus domestica/metabolismo , Temperatura
11.
Muscle Nerve ; 61(4): 535-541, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31950518

RESUMO

INTRODUCTION: In this study we investigated whether burst-modulated wide-pulse neuromuscular electrical stimulation (NMES) can improve the H-reflex and activation efficiency of sensory fibers. METHODS: NMES-induced electromyography (EMG) was recorded from hindpaw plantar muscles in 11 anesthetized rats. A burst-modulated wide pulse (mWP) with three carrier frequencies (2 kHz, 5 kHz, and 10 kHz) and a continuous wide-pulse (WP) were delivered to the tibial nerve of each rat. The evoked Hoffman (H)-reflexes were measured to evaluate nerve activation efficiency using the H-reflex recruitment curve (HRC). RESULTS: Relative to WP simulation, mWP stimulation required less electrical charge to excite sensory fibers and improved the H-reflex recruitment. Greater electrical charge and smaller recruitment gains were obtained with increased carrier frequency of mWP. DISCUSSION: mWP NMES can improve stimulation efficiency and improve recruitment of sensory fibers on tibial nerve stimulation, which may help to optimize NMES stimulus parameters.


Assuntos
Reflexo H/fisiologia , Músculo Esquelético/fisiologia , Recrutamento Neurofisiológico/fisiologia , Nervo Tibial/fisiologia , Animais , Estimulação Elétrica , Eletromiografia , Feminino , Ratos , Ratos Sprague-Dawley
12.
BMC Vet Res ; 16(1): 96, 2020 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-32293447

RESUMO

BACKGROUND: Porcine circovirus type 2 (PCV2) is the causative agent of porcine circovirus-associated disease (PCVAD). Its prevalence in swine herds was first reported in China in 2000. PCV2 infection causes immunosuppression that leads to multiple diseases, causing serious economic problems for the swine industry in China. Since information on the genetic variation of PCV2 in Yunnan province is limited, this study aims to investigate the molecular epidemiological and evolutionary characteristics of PCV2 from 2016 to 2019. METHODS: A total of 279 clinical samples were collected from different regions of Yunnan between 2016 to 2019, and PCV2 was detected by PCR. We then amplified full genomes from the positive samples, and the sequences were analysed for homology and genetic evolution. RESULTS: Overall, 60.93% (170/279) of the screened swine herd samples were positive for PCV2. We sequenced 15 Yunnan province PCV2 strains from positive samples. Analyses of the complete genomes and Cap genes led to the classification of the 15 Yunnan PCV2 strains into PCV2a (2 of 15), PCV2b (1of 15) and PCV2d (12 of 15). All strains shared 94.3-99.9% of their identities with the nucleotide sequences of complete genomes in this study and shared 94.2-99.9% identity with the reference sequences. All strains share 89.4-100% and 86.8-100% of their identities with the nucleotide and amino acid (aa) sequences of Cap, respectively. CONCLUSIONS: The results of this study provide evidence that PCV2a, PCV2b and PCV2d genotypes coexisted in Yunnan Province from 2016 to 2019, and the priority prevalence genotype was PCV2d. The data provide evidence for the increased genetic diversity and insights into the molecular epidemiology of PCV2. This study also provides basic data for the Yunnan province PCV2 molecular epidemiological survey and accumulates effective materials for the development of PCV2 vaccines.


Assuntos
Infecções por Circoviridae/veterinária , Circovirus/genética , Variação Genética , Animais , China/epidemiologia , Infecções por Circoviridae/epidemiologia , Infecções por Circoviridae/virologia , Circovirus/classificação , Evolução Molecular , Genoma Viral , Epidemiologia Molecular , Suínos , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/virologia
13.
Ecotoxicol Environ Saf ; 189: 109981, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31812021

RESUMO

Chloroacetic acid (CAA), one of typical disinfection by-products (DBPs), has attracted considerable concerns for its biological safety. Antioxidant enzyme catalase (CAT) plays a crucial part in the regulation of redox state balance. Herein, CAA was used to test its adverse effects on CAT and explore the underlying mechanism. The cell viability of mouse primary hepatocytes decreased under CAA exposure. A bell-shaped response to CAA exposure was observed in intracellular CAT activity, whose change was partly influenced by molecular CAT activity. CAA binds to CAT mainly via van der Waals forces and hydrogen bonds with a stoichiometry of 9.2. The binding caused structural changes in CAT with the unfolding of polypeptide chains and the decrease of α-helical content. CAA interacts with the amino acid residues surrounding the active sites and substrate channel of CAT. These interactions result in the decrease of molecular CAT activity, which could be restored by high ionic strength. This study has provided a combined molecular and cellular tactics for studying the adverse effects of DBPs on biomarkers and the underlying mechanisms.


Assuntos
Acetatos/toxicidade , Antioxidantes/metabolismo , Catalase/metabolismo , Poluentes Químicos da Água/toxicidade , Acetatos/química , Animais , Antioxidantes/química , Catalase/química , Sobrevivência Celular/efeitos dos fármacos , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Camundongos , Ligação Proteica , Estrutura Secundária de Proteína , Poluentes Químicos da Água/química
14.
Lasers Med Sci ; 35(2): 365-372, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31222480

RESUMO

The post-stimulation response of neural activities plays an important role to evaluate the effectiveness and safety of neural modulation techniques. Previous studies have established the capability of infrared neural modulation (INM) on neural firing regulation in the central nervous system (CNS); however, the dynamic neural activity after the laser offset has not been well characterized yet. We applied 980-nm infrared diode laser light to irradiate the primary motor cortex of rats, and tungsten electrode was inserted to record the single-unit activity of neurons at the depth of 800-1000 µm (layer V of primary motor cortex). The neural activities were assessed through the change of neural firing rate and firing pattern pre- and post-stimulation with various radiant exposures. The results showed that the 980-nm laser could modulate the firing properties of neurons in the deep layer of the cortex. More neurons with post-stimulation response (78% vs. 83%) were observed at higher stimulation intensity (0.803 J/cm2 vs. 1.071 J/cm2, respectively). The change of firing rate also increased with radiant exposures increasing, and the response lasted up to 4.5 s at 1.071 J/cm2, which was significantly longer than the theoretical thermal relaxation time. Moreover, the increasing Fano factors indicated the irregularity firing pattern of post-stimulation response. Our results confirmed that neural activity maintained a prolonged post-stimulation response after INM, which may provide necessary measurable data for optimization of INM applications in CNS.


Assuntos
Raios Infravermelhos , Córtex Motor/fisiologia , Neurônios/fisiologia , Potenciais de Ação/fisiologia , Animais , Estimulação Elétrica , Lasers Semicondutores , Masculino , Ratos Sprague-Dawley
15.
Sensors (Basel) ; 20(10)2020 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-32429490

RESUMO

This work presents a magnetic-driven deterministic lateral displacement (m-DLD) microfluidic device. A permanent magnet located at the outlet of the microchannel was used to generate the driving force. Two stages of mirrored round micropillar array were designed for the separation of magnetic beads with three different sizes in turn. The effects of the forcing angle and the inlet width of the micropillar array on the separating efficiency were studied. The m-DLD device with optimal structure parameters shows that the separating efficiencies for the 10 µm, 20 µm and 40 µm magnetic beads are 87%, 89% and 94%, respectively. Furthermore, this m-DLD device was used for antibody recognition and separation among a mixture solution of antibodies. The trajectories of different kinds of magnetic beads coupled with different antigens showed that the m-DLD device could realize a simple and low-cost diagnostic test.


Assuntos
Anticorpos , Dispositivos Lab-On-A-Chip , Técnicas Analíticas Microfluídicas , Anticorpos/análise , Fenômenos Magnéticos , Magnetismo , Imãs
16.
J Org Chem ; 84(11): 6928-6939, 2019 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-31088076

RESUMO

An iron-catalyzed methylene forming strategy is disclosed through sequential C-H and C-O bond functionalization of methanol with cosolvent water. This protocol provides an easy and novel access to methylene-tethered imidazo[1,2- a]pyridine and 2-aminopyridine analogues in a sustainable manner and represents a complementary approach to traditional methylene forming strategies.

17.
J Biochem Mol Toxicol ; 33(2): e22248, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30368982

RESUMO

Because cadmium might interact with proteins and, thus, exert toxicity in organisms, it is vital to understand the molecular mechanism of the interaction between cadmium and biologically relevant proteins as well as the structural and functional changes in these proteins. In this study, the interaction between α-chymotrypsin (α-ChT) and cadmium chloride (CdCl2 ) was investigated by performing enzyme activity determinations, multispectroscopic measurements, isothermal titration calorimetry, and molecular docking studies. It was demonstrated that CdCl 2 binds to α-ChT mainly via electrostatic forces with (21.0 ± 0.982) binding sites, leading to the increase of α-helix and the decrease of ß-sheet. The interaction between CdCl 2 and α-ChT loosened the protein skeleton and increased the molecular volume of α-ChT. CdCl 2 first binds to the interface of α-ChT and then interacts with the key residues His 57 or Asp 102 or both in the active sites, leading to the activity inhibition of α-ChT under the exposure of high CdCl 2 concentrations.


Assuntos
Cloreto de Cádmio/química , Quimotripsina/química , Cádmio/química , Domínio Catalítico , Humanos
18.
Nano Lett ; 18(3): 1699-1706, 2018 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-29356548

RESUMO

Explosives, propellants, and pyrotechnics are energetic materials that can store and quickly release tremendous amounts of chemical energy. Aluminum (Al) is a particularly important fuel in many applications because of its high energy density, which can be released in a highly exothermic oxidation process. The diffusive oxidation mechanism (DOM) and melt-dispersion mechanism (MDM) explain the ways powders of Al nanoparticles (NPs) can burn, but little is known about the possible use of plasmonic resonances in NPs to manipulate photoignition. This is complicated by the inhomogeneous nature of powders and very fast heating and burning rates. Here, we generate Al NPs with well-defined sizes, shapes, and spacings by electron beam lithography and demonstrate that their plasmonic resonances can be exploited to heat and ignite them with a laser. By combining simulations with thermal-emission, electron-, and optical-microscopy studies, we reveal how an improved control over NP ignition can be attained.

19.
Biochem Biophys Res Commun ; 503(2): 521-527, 2018 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-29758194

RESUMO

The tRNA selenocysteine 1 associated protein 1 (Trnau1ap, initially named SECp43) is involved in Selenocysteine (Sec) biosynthesis and incorporation into selenoproteins, which play a key role in biological processes, such as embryonic development. We previously reported that downregulation of Trnau1ap inhibited proliferation of cardiomyocyte-like H9c2 cells. However, the effects of Trnau1ap on cell proliferation and migration of embryonic development are not known, and the mechanisms remain elusive. Herein, lentiviral shRNA vectors were transfected in NIH3T3, JEG-3 and Bewo cells (embryonic, trophoblast and placental cells). We found that knockdown of Trnau1ap resulted in reduced expression levels of selenoproteins. The data of Cell Count Kit-8 (CCK-8) assay and wound scratch assay revealed the proliferation and migration rates were reduced in the Trnau1ap-shRNA groups. Furthermore, western blot analysis showed that the phosphorylation level of Akt in the phosphatidylinositol 3-kinase (PI3K)/Akt pathway was attenuated. These results indicate that Trnau1ap plays an important role in regulation of cell proliferation and migration through the PI3K/Akt signaling pathway, as well as being essential for embryonic development by regulating the expression of selenoproteins.


Assuntos
Movimento Celular , Proliferação de Células , Proteínas Nucleares/genética , Fosfatidilinositol 3-Quinase/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas de Ligação a RNA/genética , Transdução de Sinais , Animais , Linhagem Celular Tumoral , Técnicas de Silenciamento de Genes , Humanos , Camundongos , Células NIH 3T3 , Proteínas Nucleares/metabolismo , Proteínas de Ligação a RNA/metabolismo
20.
Nano Lett ; 17(10): 5925-5930, 2017 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-28873319

RESUMO

Silicon (Si) particles are widely utilized as high-capacity electrodes for Li-ion batteries, elements for thermoelectric devices, agents for bioimaging and therapy, and many other applications. However, Si particles can ignite and burn in air at elevated temperatures or under intense illumination. This poses potential safety hazards when handling, storing, and utilizing these particles for those applications. In order to avoid the problem of accidental ignition, it is critical to quantify the ignition properties of Si particles such as their sizes and porosities. To do so, we first used differential scanning calorimetry to experimentally determine the reaction onset temperature of Si particles under slow heating rates (∼0.33 K/s). We found that the reaction onset temperature of Si particles increased with the particle diameter from 805 °C at 20-30 nm to 935 °C at 1-5 µm. Then, we used a xenon (Xe) flash lamp to ignite Si particles under fast heating rates (∼103 to 106 K/s) and measured the minimum ignition radiant fluence (i.e., the radiant energy per unit surface area of Si particle beds required for ignition). We found that the measured minimum ignition radiant fluence decreased with decreasing Si particle size and was most sensitive to the porosity of the Si particle bed. These trends for the Xe flash ignition experiments were also confirmed by our one-dimensional unsteady simulation to model the heat transfer process. The quantitative information on Si particle ignition included in this Letter will guide the safe handling, storage, and utilization of Si particles for diverse applications and prevent unwanted fire hazards.

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