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1.
EMBO Rep ; 24(6): e55806, 2023 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-37082939

RESUMO

Argonaute (AGO) proteins use microRNAs (miRNAs) and small interfering RNAs (siRNAs) as guides to regulate gene expression in plants and animals. AGOs that use miRNAs in bilaterian animals recognize short (6-8 nt.) elements complementary to the miRNA seed region, enabling each miRNA to interact with hundreds of otherwise unrelated targets. By contrast, AGOs that use miRNAs in plants employ longer (> 13 nt.) recognition elements such that each miRNA silences a small number of physiologically related targets. Here, we show that this major functional distinction depends on a minor structural difference between plant and animal AGO proteins: a 9-amino acid loop in the PIWI domain. Swapping the PIWI loop from human Argonaute2 (HsAGO2) into Arabidopsis Argonaute10 (AtAGO10) increases seed strength, resulting in animal-like miRNA targeting. Conversely, swapping the plant PIWI loop into HsAGO2 reduces seed strength and accelerates the turnover of cleaved targets. The loop-swapped HsAGO2 silences targets more potently, with reduced miRNA-like targeting, than wild-type HsAGO2 in mammalian cells. Thus, tiny structural differences can tune the targeting properties of AGO proteins for distinct biological roles.


Assuntos
Arabidopsis , MicroRNAs , Humanos , Animais , MicroRNAs/genética , MicroRNAs/metabolismo , Proteínas Argonautas/genética , Proteínas Argonautas/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Plantas/genética , Sementes/genética , Mamíferos/genética , Mamíferos/metabolismo
2.
Mikrochim Acta ; 191(2): 112, 2024 01 29.
Artigo em Inglês | MEDLINE | ID: mdl-38286966

RESUMO

For the first time, a tumour hypoxia marker detection has been developed using two-dimensional layered composite modified electrodes in biological and environmental samples. The concept of TaB2 and V4C3-based MXene composite materials is not reported hitherto using ball-milling and thermal methods and it remains the potentiality of the present work. The successful formation is confirmed through various characterisation techniques like X-ray crystallography, scanning electron microscopy photoelectron, and impedance spectroscopy. A reliable and repeatable electrochemical sensor based on TaB2@V4C3/SPCE was developed for quick and extremely sensitive detection of pimonidazole by various electroanalytical methods. It has been shown that the modified electrode intensifies the reduction peak current and causes a decrease in the potential for reduction, in comparison with the bare electrode. The proposed sensor for pimonidazole reduction has strong electrocatalytic activity and high sensitivity, as demonstrated by the cyclic voltammetry approach. Under the optimal experimental circumstances, differential pulse voltammetry techniques were utilised for generating the wide linear range (0.02 to 928.51 µM) with a detection limit of 0.0072 µM. The resultant data demonstrates that TaB2@V4C3/SPCE nano-sensor exhibits excellent stability, reliability, and repeatability in the determination of pimonidazole. Additionally, the suggested sensor was successfully used to determine the presence of pimonidazole in several real samples, such as human blood serum, urine, water, and drugs.


Assuntos
Carbono , Nitroimidazóis , Tantálio , Humanos , Carbono/química , Vanádio , Reprodutibilidade dos Testes , Limite de Detecção , Eletrodos , Compostos de Boro
3.
Respir Res ; 24(1): 111, 2023 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-37061730

RESUMO

BACKGROUND: Non-small cell lung cancer (NSCLC) is the main type of the most common malignant tumor in the world. Previous studies have shown that the expression level of mitochondrial creatine kinase 1 (CKMT1) is abnormal in NSCLC, but the mechanism of its effect remains unclear. Therefore, in this study, we intend to clarify the potential mechanism of CKMT1 in NSCLC and provide the theoretical basis for the clinical application of CKMT1. METHODS: The function of CKMT1 in NSCLC was identified by analyzing the GEO dataset and evaluating using in vitro and in vivo models. Protein mass spectrometry was used to find proteins interacting with CKMT1, and Co-immunoprecipitation (Co-IP) and GST-pull down experiments were used to verify the interaction between proteins. The immunofluorescence (IF) assay was used to explore the functional position of CKMT1 in cells. The effect of CKMT1 expression level on the efficacy of paclitaxel (TAX) in the treatment of NSCLC was analyzed by a combined TAX experiment in vivo and in vitro. RESULTS: CKMT1 expression was increased in NSCLC and CKMT1 promoted the proliferation of NSCLC cells in vitro and in vivo. CKMT1 knockdown resulted in a significantly increased G0/G1 fraction and decreased S phase cell fraction, indicating G1 phase arrest. Mechanically, the cyclin-dependent kinase 4 (CDK4) was identified to interact with CKMT1, and the crucial binding areas were focused on the DH domain of CKMT1 and the N- and C-terminal of CDK4. A fraction of the CDK4 proteins colocalize and interact with the CKMT1 at mitochondria, the level of phosphorylated CDK4 was regulated by CKMT1. Hence, the decrease in CKMT1 expression level could increase the antitumor effect of G2/M cell cycle antagonist-TAX in NSCLC in vitro and in vivo. CONCLUSIONS: CKMT1 could interact with CDK4 in mitochondria and regulate the phosphorylated level of CDK4, thus contributing to the proliferation and cell cycle transition of NSCLC cells. And CKMT1 could be a potential target to improve the sensitivity of chemotherapy based on TAX.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Ciclo Celular , Linhagem Celular Tumoral , Proliferação de Células , Creatina Quinase Mitocondrial , Quinase 4 Dependente de Ciclina/genética , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia
4.
Chemistry ; 29(51): e202300655, 2023 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-37227809

RESUMO

Bioluminogenic probes emerged as powerful tools for imaging and analysis of various bioanalyses, but traditional approaches would be limited to the low sensitivity during determine the low activity of protease in clinical specimens. Herein, we proposed a caged luciferase inhibitor-based bioluminescence-switching strategy (CLIBS) by using a cleavable luciferase inhibitor to modulate the activity of luciferase reporter to amplify the detective signals, which led to the enhancement of detection sensitivity, and enabled the determination of circulating Aminopeptidase N (APN) activity in thousands of times diluted serum. By applying the CLIBS to serum samples in non-small cell lung cancer (NSCLC) patients from two clinical cohorts, we revealed that, for the first time, higher circulating APN activities but not its concentration, were associated with more NSCLC metastasis or higher metastasis stages by subsequent clinical analysis, and can serve as an independent factor for forecasting NSCLC patients' risk of metastasis.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Antígenos CD13 , Luciferases
5.
Psychol Med ; 53(10): 4364-4372, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-35477437

RESUMO

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic is an unprecedented global health crisis that may cause mental health problems and heighten suicide risk. We investigated the impact of the COVID-19 pandemic on trends in suicide attempts and suicide deaths in New Taipei City, Taiwan. METHODS: The current study used the official daily data on suicide attempts and deaths in New Taipei City, Taiwan (4 million inhabitants) between 2015 and 2020 from the Taiwan National Suicide Prevention Reporting System. Interrupted time-series (ITS) analyses with parameters corrected by the estimated autocorrelations were applied on weekly aggregated data to examine whether the suicide trends during the early COVID-19 pandemic (late January to July 2020) deviated from previous trends (January 2015 to late January 2020). The impact due to the suicide prevention policy change was also examined (since August 2020). RESULTS: ITS analyses revealed no significant increases in both mean and trend on weekly suicide deaths during the COVID-19 pandemic and after the policy change. In contrast, there was a significant increasing trend in weekly suicide attempts since the COVID-19 outbreak at the rate of 1.54 attempts per week (95% confidence interval 0.49-2.60; p = 0.004). Sex difference analysis revealed that, however, this increasing trend was observed only in females not in males. CONCLUSIONS: The COVID-19 pandemic has different impacts on suicides attempts and deaths during the early pandemic in New Taipei City, Taiwan. The COVID-19 outbreak drastically increased the trend of suicide attempts. In contrast, the number of suicide deaths had remained constant in the investigated periods.


Assuntos
COVID-19 , Tentativa de Suicídio , Humanos , Masculino , Feminino , Taiwan/epidemiologia , Pandemias , Cidades
6.
BJU Int ; 131(2): 198-207, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-35704436

RESUMO

OBJECTIVES: To evaluate the anti-tumour activity and safety of anti-programmed death receptor-1 (PD-1) antibody plus epidermal growth factor receptor blockade combined with platinum-based chemotherapy (PEP) as first-line therapy for stage IV penile squamous cell carcinoma (PSCC). PATIENTS AND METHODS: We conducted a retrospective review of 17 patients with stage IV PSCC undergoing first-line PEP at Sun Yat-sen University Cancer Center between January 2018 and September 2021. Clinical responses were assessed using the Response Evaluation Criteria in Solid Tumours (RECIST) version 1.1. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method. Adverse events (AEs) were graded according to Common Terminology Criteria for Adverse Events version 5.0. RESULTS: Of 17 patients who received first-line PEP, 13 were observed to have partial responses. Twelve patients subsequently received consolidated surgery. Nine of these achieved pN0 status, of whom six with locally advanced PSCC achieved pathological complete response. The median (range) follow-up time was 24.87 (3.63-29.40) months. Median PFS and median OS were not reached, with 2-year PFS and OS rates being 68.4% (95% confidence interval [CI] 48.7-96.1) and 62.9% (95% CI 41.6-95), respectively. Eight patients experienced Grade 3 or 4 treatment-related AEs. No Grade 5 AEs or death associated with treatment was observed. CONCLUSIONS: Anti-PD-1 antibody plus epidermal growth factor receptor blockade and platinum-based chemotherapy showed promising anti-tumour activity, acceptable toxicity, and satisfying long-term survival for stage IV PSCC. Larger clinical trials are needed to validate our findings.


Assuntos
Carcinoma de Células Escamosas , Neoplasias Pulmonares , Neoplasias Penianas , Masculino , Humanos , Neoplasias Penianas/tratamento farmacológico , Neoplasias Penianas/patologia , Receptores ErbB , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/patologia , Intervalo Livre de Progressão , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Receptores de Morte Celular , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia
7.
Phys Chem Chem Phys ; 25(46): 32100-32109, 2023 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-37982601

RESUMO

In order to further clarify the effect of sulfur doping on the laser damage threshold of potassium dihydrogen phosphate (KDP), the properties of sulfur substituting for phosphorus doping defects (SP) in KDP crystals with paraelectric (PE) and ferroelectric (PE) phases are studied in this article. More accurate defect transition levels were obtained by band edge correction, and the band edge corrected values were 1.28 eV and 1.88 eV for the PE and FE phases, respectively. The defect formation energies with four different defect charges (0, +1, +2, and-1) were obtained using the finite size correction scheme. The stable defect charge states were (+2 charge state) (+1 charge state) and (-1 charge state) in turn when the Fermi level moved from the valence band maximum (VBM) to the conduction band minimum (CBM). Moreover, by considering the electron-phonon coupling, the optical absorption and emission spectra were obtained. The absorption peak for the state of the PE phase at 4.63 eV was close to the experimental value. We predicted that the absorption peak at 4.50 eV belongs to the state with the FE phase. The emission peaks at 0.10 eV and 1.36 eV were related to the PE and FE phases, accordingly. The absorption may affect the application of S-KDP crystals and reduce the laser damage threshold.

8.
Environ Res ; 216(Pt 2): 114609, 2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-36272591

RESUMO

Excessive use of nitrofurantoin (NFT) and its residues can be harmful to the ecosystem, and to mitigate this, rapid and cost-effective detection of NFT in water bodies is needed. In this regard, we prepared a three-dimensional (3D) copper-zeolitic imidazole framework (Cu/ZIF-8)-derived bimetallic Cu5Zn8 alloy-embedded hollow porous carbon nanocubes (Cu5Zn8/HPCNC) for electrochemical detection of NFT. The resultant material is characterized using suitable spectrophotometry and voltammetry methods. Cu5Zn8/HPCNC is an effective electrocatalyst with high electrical conductivity and a fast electron transfer rate. It also has more catalytic active sites for improved electrochemical reduction of NFT. Fabricated Cu5Zn8/HPCNC-modified screen-printed electrode (SPE) for NFT reduction have a wide linear range with a low detection limit, and high sensitivity (15.343 µA µÐœ-1 cm-2), appreciable anti-interference ability with related nitro compounds, storage stability, reproducibility, and repeatability. Also, the practicability of Cu5Zn8/HPCNC/SPE can be successfully employed in NFT monitoring in water bodies (drinking water, pond water, river water, and tap water) with satisfactory recoveries.


Assuntos
Carbono , Poluentes Ambientais , Carbono/química , Técnicas Eletroquímicas , Porosidade , Ligas , Reprodutibilidade dos Testes , Ecossistema , Água , Zinco
9.
J Vis ; 23(5): 9, 2023 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-37163245

RESUMO

Visual crowding can be reduced when attention is directed to the target by peripheral cues. However, it is unclear whether central cues relieve visual crowding to the same extent as peripheral cues. In this study, we combined the Posner cueing task and the crowding task to investigate the effect of exogenous and endogenous attention on crowding. In Experiment 1, five different stimulus-onset asychronies (SOAs) between the cue and the target and a predictive validity of 100% were adopted. Both attentional cues were shown to significantly reduce the effect of visual crowding, but the peripheral cue was more effective than the central cue. Furthermore, peripheral cues started to relieve visual crowding at the shortest SOA (100 ms), whereas central cues worked only at later SOAs (275 ms or above). When the predictive validity of the cue was decreased to 70% in Experiment 2, similar results to Experiment 1 were found, but the valid cue was less effective in reducing crowding than that in Experiment 1. In Experiment 3, when the predictive validity was decreased to 50%, a valid peripheral cue improved performance but a valid central cue did not, suggesting that endogenous attention but not exogenous attention can be voluntarily controlled when the cues are not predictive of the target's location. These findings collectively suggest that both peripheral and central cues can alleviate crowding, but they differ in terms of strength, time dynamics, and flexibility of voluntary control.


Assuntos
Atenção , Sinais (Psicologia) , Humanos , Tempo de Reação , Aglomeração
10.
Mikrochim Acta ; 189(11): 409, 2022 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-36205813

RESUMO

Cube-shaped samarium orthovanadate (SmVO4) nanoparticles were interconnected with a graphene oxide sheet (GOS) using a simple and eco-friendly method to generate a SmVO4@GOS nanocomposite. SmVO4 was characterized using various spectroscopic and microscopic techniques, which confirmed the wrapping of GOS around the SmVO4 nanoparticles. SmVO4@GOS was then used to modify a glassy carbon electrode (GCE), which was evaluated for its electrochemical performance toward the assay of sulfasalazine (SSZ), an antibiotic drug. Cyclic voltammetry and amperometry were both used for the assay of SSZ using the SmVO4@GOS-modified GCE at pH 7. The modified amperometric sensor is more sensitive, with a low detection limit (2.16 nM) and wide linear range of 20 nM-667 µM (Ag/AgCl). The electrochemical oxidation of SSZ was tested with blood serum and urine samples at physiological pH with recoveries in the range 96.1-98.6%. It indicates that the modified electrochemical sensor has good sensitivity and practical applicability toward SSZ detection. In the field of non-enzymatic sensors, SmVO4@GOS/GCE provides a highly promising performance. Therefore, the electrochemical sensors have capacity for extensive analytical applications in biomedical devices.


Assuntos
Nanopartículas , Óxidos , Antibacterianos , Carbono/química , Eletrodos , Grafite , Concentração de Íons de Hidrogênio , Nanopartículas/química , Óxidos/química , Samário , Sulfassalazina , Vanadatos
11.
J Formos Med Assoc ; 121(5): 978-985, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-34353719

RESUMO

BACKGROUND/PURPOSE: Recently optimized models for selecting the locations of hospitals capable of providing endovascular thrombectomy (EVT) did not consider the accuracy of the prehospital stroke scale assessment and possibility of secondary transport. Our study aimed to propose a new model for selecting existing hospitals with intravenous thrombolysis capability to become EVT-capable hospitals. METHODS: A sequential order was provided to upgrade hospitals providing intravenous thrombolysis, using a mixed integer programming model based on current medical resource allocation. In addition, we drafted a centralized plan to redistribute existing EVT resources by redetermining locations of EVT-capable hospitals. Using historical data of 7679 on-scene patients with suspected stroke, the model was implemented to determine the hospital that maximizes the number of patients receiving EVT treatment within call-to-definitive-treatment time. RESULTS: All suspected stroke patients were sent to EVT-capable hospitals directly under the current medical resource allocation model. After upgrading one additional hospital to become an EVT-capable hospital, the percentage of patients receiving definitive treatment within the standard call-to-definitive-treatment time was elevated from 68.82% to 72.97%. In the model, assuming that there is no hospital providing EVT, all patients suspected of stroke will be sent to EVT-capable hospitals directly after upgrading three or more hospitals to be able to provide treatment. CONCLUSION: All patients eligible for acute stroke treatment are sent to EVT-capable hospitals in the simulation under the current medical resource allocation model. This model can be utilized to provide insights for capacity redistribution in other regions.


Assuntos
Isquemia Encefálica , Procedimentos Endovasculares , Acidente Vascular Cerebral , Isquemia Encefálica/terapia , Hospitais , Humanos , Acidente Vascular Cerebral/cirurgia , Trombectomia , Tempo para o Tratamento , Resultado do Tratamento
12.
Microb Pathog ; 144: 104182, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32247644

RESUMO

Layer chickens were artificially challenged with infectious bursal disease virus (IBDV), and the kinetics of IFN-λ and antiviral genes in the bursa were explored using quantitative real-time PCR. Data showed that after the chickens were infected with IBDV, the virus load in the bursa of the Fabricius peaked at 96 h and gradually decreased. The relative mRNA expression levels of IFN-λ and antiviral genes (zinc-finger antiviral protein [ZAP], interferon alpha-inducible protein 6 [IFI6], laboratory of genetics and physiology 2 [LGP2], virus inhibitory protein [Viperin], and Mx) of the infected group dramatically increased at 24-168 h compared with those of the negative-infected group. Furthermore, the ZAP mRNA expression peaked at 24 h (3.97-fold). The Viperin mRNA transcript level was highest at 48 h (384.60-fold). The mRNA expression levels of IFI6 (96.31-fold), LGP2 (18.29-fold), and Mx (88.85-fold) peaked at 72 h, and that of IFN-λ was most remarkable at 96 h (2978.81-fold). Furthermore, the ZAP change rule was significantly positively correlated with the change rule of the IBDV load. The mRNA expression levels of IFN-λ and antiviral genes (ZAP, IFI6, LGP2, Viperin, and Mx) increased as the virus expression increased and then decreased. These results further corroborated that the IBDV infection seriously interfered with the chicken's innate immune response.


Assuntos
Antivirais/metabolismo , Infecções por Birnaviridae/metabolismo , Expressão Gênica , Vírus da Doença Infecciosa da Bursa/fisiologia , Interferons/metabolismo , Animais , Infecções por Birnaviridae/virologia , Bolsa de Fabricius/virologia , Galinhas/imunologia , Imunidade Inata , Interferons/genética , Proteínas Mitocondriais/metabolismo , Doenças das Aves Domésticas/virologia , RNA Helicases/metabolismo , Proteínas Repressoras/metabolismo
13.
Cereb Cortex ; 29(6): 2737-2747, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30843060

RESUMO

Chronic stress has been observed to increase the risk of developing depression and induce neuronal alterations of synaptic plasticity, yet the underlying molecular mechanisms remain unclear. Here, we found that the ubiquitously expressed RNA-binding protein HuR was up-regulated in the medial prefrontal cortex (mPFC) of mice following chronic stress. In adult mice, AAV-Cre-mediated knockout of HuR in the mPFC prevented anxiety-like and depression-like behaviors induced by chronic stress. HuR was also required for the stress-induced dendritic spine loss and synaptic transmission deficits. Moreover, HuRflox/flox;Nex-Cre mice, which induce HuR loss of function from embryonic development, exhibited enhanced synaptic functions. Notably, we ascertained RhoA signaling to be regulated by HuR and involved in the modulation of structural synaptic plasticity in response to chronic stress. Our results demonstrate HuR is a critical modulator for the regulation of stress-induced synaptic plasticity alterations and depression, providing a potential therapeutic target for the treatment of depressive disorders.


Assuntos
Depressão/metabolismo , Proteína Semelhante a ELAV 1/metabolismo , Plasticidade Neuronal/fisiologia , Córtex Pré-Frontal/metabolismo , Animais , Depressão/etiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Restrição Física , Estresse Psicológico/complicações
14.
Biochem Biophys Res Commun ; 511(2): 369-373, 2019 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-30803756

RESUMO

Substance P is one of the major neuropeptides released by striatal neurons; however, its function in the striatum remains unclear. In this study, we found substance P triggers spontaneous neurotransmitter release and rapid synaptic vesicle exocytosis in cultured striatal neurons, as substance P knockdown in these neurons impaired spontaneous neurotransmitter release and calcium-dependent rapid synaptic neurotransmission. Furthermore, treatment with exogenous substance P completely rescued the synaptic dysfunction phenotype in striatal neurons lacking this neuropeptide. On the other hand, substance P knockdown had no effect on the size of the readily releasable pool of synaptic vesicles, but decreased the probability of presynaptic release of synaptic vesicles in cultured striatal neurons. Treatment with CP96345, a NK1 receptor antagonist, also resulted in synaptic defects in cultured striatal neurons. In summary, we propose substance P is critical for synaptic transmission in striatal neurons.


Assuntos
Neurônios/metabolismo , Substância P/metabolismo , Transmissão Sináptica , Animais , Células Cultivadas , Corpo Estriado/citologia , Corpo Estriado/metabolismo , Camundongos , Neurônios/citologia , Terminações Pré-Sinápticas/metabolismo , Vesículas Sinápticas/metabolismo
15.
Langmuir ; 34(15): 4651-4657, 2018 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-29554798

RESUMO

An electrically induced bottom-up process was introduced for the fabrication of multifunctional nanostructures of polymers. Without requiring complicated photolithography or printing techniques, the fabrication process first produced a conducting template by colloidal lithography to create an interconnected conduction pathway. By supplying an electrical charge to the conducting network, the conducting areas were enabled with a highly energized surface that generally deactivated the adsorbed reactive species and inhibited the vapor deposition of poly- p-xylylene polymers. However, the template allowed the deposition of ordered poly- p-xylylene nanostructures only on the confined and negative areas of the conducting template, in a relatively large centimeter-scale production. The wide selection of functionality and multifunctional capability of poly- p-xylylenes naturally rendered the synergistic and orthogonal chemical reactivity of the resulting nanostructures. With only a few steps, the construction of a nanometer topology with the functionalization of multiple chemical conducts can be achieved, and the selected deposition process represents a state-of-the-art nanostructure fabrication in a simple and versatile approach from the bottom up.

16.
Asian-Australas J Anim Sci ; 30(6): 788-796, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27703133

RESUMO

OBJECTIVE: In order to improve fermentation quality of natural grasses, their silage preparation and fermentation quality in meadow steppe (MS) and typical steppe (TS) were studied. METHODS: The small-scale silages and round bale silages of mixed natural grasses in both steppes were prepared using the commercial lactic acid bacteria (LAB) inoculants Chikuso-1 (CH, Lactobacillus plantarum) and cellulase enzyme (AC, Acremonium cellulase) as additives. RESULTS: MS and TS contained 33 and 9 species of natural grasses, respectively. Stipa baicalensis in MS and Stipa grandi in TS were the dominant grasses with the highest dry matter (DM) yield. The crude protein (CP), neutral detergent fiber and water-soluble carbohydrate of the mixed natural grasses in both steppes were 8.02% to 9.03%, 66.75% to 69.47%, and 2.02% to 2.20% on a DM basis, respectively. All silages treated with LAB and cellulase were well preserved with lower pH, butyric acid and ammonia-N content, and higher lactic acid and CP content than those of control in four kinds of silages. Compared with CH- or AC-treated silages, the CH+ AC-treated silages had higher lactic acid content. CONCLUSION: The results confirmed that combination with LAB and cellulase may result in beneficial effects by improving the natural grass silage fermentation in both grasslands.

17.
Small ; 12(11): 1458-68, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26814978

RESUMO

A high-sensitivity and low-power theranostic nanosystem that combines with synergistic photothermal therapy and surface-enhanced Raman scattering (SERS) mapping is constructed by mesoporous silica self-assembly on the reduced graphene oxide (rGO) nanosheets with nanogap-aligned gold nanoparticles (AuNPs) encapsulated and arranged inside the nanochannels of the mesoporous silica layer. Rhodamine 6G (R6G) as a Raman reporter is then encapsulated into the nanochannels and anti-epidermal growth factor receptor (EGFR) is conjugated on the nanocomposite surface, defined as anti-EGFR-PEG-rGO@CPSS-Au-R6G, where PEG is polyethylene glycol and CPSS is carbon porous silica nanosheets. SERS spectra results show that rGO@CPSS-Au-R6G enhances 5 × 10(6) magnification of the Raman signals and thus can be applied in the noninvasive cell tracking. Furthermore, it displays high sensitivity (detection limits: 10(-8) m R6G solution) due to the "hot spots" effects by the arrangements of AuNPs in the nanochannels of mesoporous silica. The highly selective targeting of overexpressing EGFR lung cancer cells (A549) is observed in the anti-EGFR-PEG-rGO@CPSS-Au-R6G, in contrast to normal cells (MRC-5). High photothermal therapy efficiency with a low power density (0.5 W cm(-2) ) of near-infrared laser can be achieved because of the synergistic effect by conjugated AuNPs and rGO nanosheets. These results demonstrate that the anti-EGFR-PEG-rGO@CPSS-Au-R6G is an excellent new theranostic nanosystem with cell targeting, cell tracking, and photothermal therapy capabilities.


Assuntos
Receptores ErbB/metabolismo , Ouro/química , Grafite/química , Hipertermia Induzida , Nanopartículas/química , Fototerapia , Dióxido de Silício/química , Análise Espectral Raman/métodos , Nanomedicina Teranóstica/métodos , Células A549 , Sobrevivência Celular , Humanos , Lasers , Microscopia de Fluorescência , Nanopartículas/ultraestrutura , Oxirredução , Porosidade
18.
Nanotechnology ; 25(33): 335301, 2014 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-25060983

RESUMO

We demonstrate a process to selectively tune the pore size of an individual nanochannel in an array of high-aspect-ratio anodic aluminum oxide (AAO) nanochannels in which the pore sizes were originally uniform. This novel process enables us to fabricate arrays of AAO nanochannels of variable sizes arranged in any custom-designed geometry. The process is based on our ability to selectively close an individual nanochannel in an array by using focused ion beam (FIB) sputtering, which leads to redeposition of the sputtered material and closure of the nanochannel with a capping layer of a thickness depending on the energy of the FIB. When such a partially capped array is etched in acid, the capping layers are dissolved after different time delays due to their different thicknesses, which results in differences in the time required for the following pore-widening etching processes and therefore creates an array of nanochannels with variable pore sizes. The ability to fabricate such AAO templates with high-aspect-ratio nanochannels of tunable sizes arranged in a custom-designed geometry paves the way for the creation of nanophotonic and nanoelectronic devices.

19.
Environ Sci Pollut Res Int ; 31(13): 19274-19293, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38358635

RESUMO

Considering the opening of high-speed railway (HSR) as a quasi-natural experiment, this paper explores the emission reduction effect of HSR opening and its mechanisms and heterogeneity characteristics based on the panel data of 272 cities in China from 2006 to 2019 by staggered DID model and the mediating effect model. It is found that (1) the opening of HSR significantly reduces the carbon emission level of cities, and the conclusion still holds after controlling the endogeneity issue and a series of robustness tests; (2) Bancon decomposition and negative weight diagnostics both show that the estimated average treatment effect bias is small and the robust estimators are more robust; (3) by reducing production costs and promoting inter-regional industrial division of labor, the opening of HSR promotes intra-industrial structural transformation and inter-industrial structural transformation, respectively, thus reducing urban carbon emissions. At the same time, HSR achieves urban carbon emission reduction by promoting free movement of population and human capital agglomeration; and (4) further study finds that there is regional heterogeneity in the emission reduction effect of HSR opening, and the carbon reduction effect is mainly reflected in large and medium-sized cities, near provincial capitals, non-resource-based cities, and cities with rich educational resources, which indicates that the location of future HSR should be combined with the city's own characteristics and be tailored to the city.


Assuntos
Carbono , Indústrias , Humanos , China , Cidades , Movimento , Desenvolvimento Econômico
20.
Spectrochim Acta A Mol Biomol Spectrosc ; 319: 124488, 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-38820818

RESUMO

The electronic structures, defect formations, defect transition levels and optical properties for VK+Hi defect models in KDP crystals have been studied based on DFT. Lattice dynamics methods give the most reasonable compensation mechanism for VK, namely compensation with the third-nearest Hi neighbor from VK for the paraelectric (PE) phase and compensation with the fourth-nearest neighbor Hi from VK for the ferroelectric (FE) phase. The defect formation energies indicate that the [Formula: see text] (The superscript represents the charged state, the 'x' represents neutral, ''' represents -1 charge state and '.' represents +1 charge state.) is the main defect type in this kind of defect cluster and a self-trapped electron is located at Hi in the (VK + Hi)' system. For [Formula: see text] system, one electron is accommodated in VK. There is not a new defect state in the band gap. The Hi bonds with the O ion (0.99 Å) form a hydroxyl. For (VK + Hi)' system, the hydroxyl is broken, the Hi exists in an atomic form and introduces new defect states in the band gap. As the large relaxation energy leads to a large Huang-Rhys factor, the Stokes red shifts will significantly affect the optical properties. A broad ultraviolet (UV) absorption band and emission band range from UV to visible are obtained originating from the defect cluster. We believe that the far-violet absorption peaks (167 nm and 179 nm) caused by defect cluster VK+Hi can significantly impact the optical damage threshold of the KDP.

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