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1.
PLoS Pathog ; 20(3): e1012082, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38470932

RESUMO

Ferroptosis, a defensive strategy commonly employed by the host cells to restrict pathogenic infections, has been implicated in the development and therapeutic responses of various types of cancer. However, the role of ferroptosis in oncogenic Kaposi's sarcoma-associated herpesvirus (KSHV)-induced cancers remains elusive. While a growing number of non-histone proteins have been identified as acetylation targets, the functions of these modifications have yet to be revealed. Here, we show KSHV reprogramming of host acetylation proteomics following cellular transformation of rat primary mesenchymal precursor. Among them, SERPINE1 mRNA binding protein 1 (SERBP1) deacetylation is increased and required for KSHV-induced cellular transformation. Mechanistically, KSHV-encoded viral interleukin-6 (vIL-6) promotes SIRT3 deacetylation of SERBP1, preventing its binding to and protection of lipoyltransferase 2 (Lipt2) mRNA from mRNA degradation resulting in ferroptosis. Consequently, a SIRT3-specific inhibitor, 3-TYP, suppresses KSHV-induced cellular transformation by inducing ferroptosis. Our findings unveil novel roles of vIL-6 and SERBP1 deacetylation in regulating ferroptosis and KSHV-induced cellular transformation, and establish the vIL-6-SIRT3-SERBP1-ferroptosis pathways as a potential new therapeutic target for KSHV-associated cancers.


Assuntos
Ferroptose , Herpesvirus Humano 8 , Neoplasias , Sarcoma de Kaposi , Sirtuína 3 , Ratos , Animais , Herpesvirus Humano 8/genética , Sirtuína 3/genética , Sirtuína 3/metabolismo , Transformação Celular Neoplásica , Proteínas Virais/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
2.
Small ; : e2311520, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38299465

RESUMO

LiCoO2 (LCO) cathode materials have attracted significant attention for its potential to provide higher energy density in current Lithium-ion batteries (LIBs). However, the structure and performance degradation are exacerbated by increasing voltage due to the catastrophic reaction between the applied electrolyte and delithiated LCO. The present study focuses on the construction of physically and chemically robust Mg-integrated cathode-electrolyte interface (MCEI) to address this issue, by incorporating Magnesium bis(trifluoromethanesulfonyl)imide (Mg[TFSI]2 ) as an electrolyte additive. During formation cycles, the strong MCEI is formed and maintained its 2 nm thickness throughout long-term cycling. Notably, Mg is detected not only in the robust MCEI, but also imbedded in the surface of the LCO lattice. As a result, the parasitic interfacial side reactions, surface phase reconstruction, particle cracking, Co dissolution and shuttling are considerably suppressed, resulting in long-term cycling stability of LCO up to 4.5 V. Therefore, benefit from the double protection of the strong MCEI, the Li||LCO coin cell and the Ah-level Graphite||LCO pouch cell exhibit high capacity retention by using Mg-electrolyte, which are 88.13% after 200 cycles and 90.4% after 300 cycles, respectively. This work provides a novel approach for the rational design of traditional electrolyte additives.

3.
Langmuir ; 39(13): 4777-4788, 2023 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-36947690

RESUMO

Metal-directed interfacial self-assembly of well-defined coordination polymer (CP) ultrathin films can control the metal complex arrangement and distribution at the molecular level, providing a convenient route for the design and fabrication of novel opto-electrical devices and heterogeneous catalysts. Here, we report the assembly of two series of CP multilayers with the transition-metal ions of Fe2+, Co2+, Zn2+ and Tb3+ as connectors and tripodal terpyridyl ligands of 4,4',4″-(1,3,5-triazine-2,4,6-triyl)tris(1-(4-([2,2':6',2″-terpyridin]-4'-yl)benzyl)pyridin-1-ium) (TerPyTa) and 4,4',4″-(benzene-1,3,5-triyl)tris(1-(4-([2,2':6',2″-terpyridin]-4'-yl)benzyl)pyridin-1-ium) (TerPyBen) as linkers at the air-water interface. The as-prepared Langmuir-Blodgett (LB) films display strong luminescence, with the emission wavelength and relative intensity dependent on both the metal ions and linkers; among them, the Zn-TerPyTa and Zn-TerPyBen CPs give off the strongest luminescent emission centered at about 370 nm with an emission lifetime of approximately 0.2-0.3 ns. The Tb-TerPyTa CPs can give off emission at approximately 490, 546, 586, and 622 nm, attributed to the 5D4 to 7F3-6 electron transitions of typical Tb3+ ions. Finally, these CP LB films can act as efficient heterogeneous photocatalysts for the CO2 reduction to selectively produce CO. The catalytic efficiency can be optimized by adjusting the experimental conditions (light sensitizer, electron donor, and water content) and CP composition (metal ion and ligand) with an excellent yield of up to 248.1 mmol g-1. In particular, it is revealed that, under the same conditions, the catalytic efficiency of the Fe-TerPyTa CP LB film is nearly 2 to 3 orders of magnitude higher than that of the other metalated complexes investigated in the homogeneous system. UV-vis spectroscopy and cyclic voltammetry studies demonstrated that the dual active sites of Fe-terpyridine and TerPyTa units contribute to the enhanced catalytic activity. This work provides an effective method to introduce the earth-abundant metal complexes into CP films to construct efficient noble-metal-free photocatalysts for the CO2 reduction.

4.
Molecules ; 28(5)2023 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-36903466

RESUMO

The application of plant dyes in the textile industry has been very limited due to their limited sources, incomplete color space, and narrow color gamut, etc. Therefore, studies of the color properties and color gamut of natural dyes and the corresponding dyeing processes are essential for completing the color space of natural dyes and their application. In this study, water extract from the bark of Phellodendron amurense (P. amurense) was used as a dye. Dyeing properties, color gamut, and color evaluation of dyed cotton fabrics were studied, and optimal dyeing conditions were obtained. The results showed that the optimal dyeing process was pre-mordanting with liquor ratio at 1:50, P. amurense dye concentration at 5.2 g/L, mordant concentration (aluminum potassium sulfate) at 5 g/L, dyeing temperature at 70 °C, dyeing time of 30 min, mordanting time of 15 min, and pH 5. Through the optimization of the dyeing process, a maximum color gamut range was obtained with lightness L* value from 74.33 to 91.23, a* value from -0.89 to 2.96, b* value from 4.62 to 34.08, chroma C* value from 5.49 to 34.09, and hue angle h° value from 57.35° to 91.57°. Colors from light yellow to dark yellow were obtained, among which 12 colors were identified according to the Pantone Matching Systems. The color fastness against soap-washing, rubbing, and sunlight on the dyed cotton fabrics all reached grade 3 level or above, further expanding the applicability of natural dyes.

5.
Int J Mol Sci ; 23(14)2022 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-35887335

RESUMO

CRISPR/Cas9-based cytosine base editors (CBEs) and adenine base editors (ABEs) can efficiently mediate C-to-T/G-to-A and A-to-G/T-to-C substitutions, respectively; however, achieving base transversions (C-to-G/C-to-A and A-to-T/A-to-C) is challenging and has been rarely studied in plants. Here, we constructed new plant C-to-G base editors (CGBEs) and new A-to-Y (T/C) base editors and explored their base editing characteristics in rice. First, we fused the highly active cytidine deaminase evoFENRY and the PAM-relaxed Cas9-nickase variant Cas9n-NG with rice and human uracil DNA N-glycosylase (rUNG and hUNG), respectively, to construct CGBE-rUNG and CGBE-hUNG vector tools. The analysis of five NG-PAM target sites showed that these CGBEs achieved C-to-G conversions with monoallelic editing efficiencies of up to 27.3% in T0 rice, with major byproducts being insertion/deletion mutations. Moreover, for the A-to-Y (C or T) editing test, we fused the highly active adenosine deaminase TadA8e and the Cas9-nickase variant SpGn (with NG-PAM) with Escherichia coli endonuclease V (EndoV) and human alkyladenine DNA glycosylase (hAAG), respectively, to generate ABE8e-EndoV and ABE8e-hAAG vectors. An assessment of five NG-PAM target sites showed that these two vectors could efficiently produce A-to-G substitutions in a narrow editing window; however, no A-to-Y editing was detected. Interestingly, the ABE8e-EndoV also generated precise small fragment deletions in the editing window from the 5'-deaminated A base to the SpGn cleavage site, suggesting its potential value in producing predictable small-fragment deletion mutations. Overall, we objectively evaluated the editing performance of CGBEs in rice, explored the possibility of A-to-Y editing, and developed a new ABE8e-EndoV tool, thus providing a valuable reference for improving and enriching base editing tools in plants.


Assuntos
Edição de Genes , Oryza , Sistemas CRISPR-Cas/genética , Desoxirribonuclease I/genética , Escherichia coli/genética , Guanina/análogos & derivados , Humanos , Oryza/genética
6.
Bull Environ Contam Toxicol ; 109(6): 1059-1066, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36287236

RESUMO

Soil heavy metal pollution is widespread around the world. Compared with hyperaccumulation plants, non-hyperaccumulator plant communities have many advantages in the remediation of heavy metals pollution in soil. The application of nitrogen (N) and phosphorus (P) is inexpensive and convenient, which can promote the growth of plant. N and P fertilizer might increase plant community remediation of heavy metal polluted soils. In our study, the effects of N and P fertilizer on remediation of soil Cd, Cu, Pb pollution by plant community were studied through a greenhouse experiment. Our results indicated that addition of N, P and N + P fertilizer increased plant community aboveground biomass. Simultaneously, addition of N and P fertilizer increased the accumulation of heavy metals in aboveground of the plant community and accelerated plants absorption soil heavy metals. Among them, N fertilizer had the best effect. Our results provide an inexpensive method for remediation heavy metal pollution of contaminated farmland, abandoned land and mine tailings, etc.


Assuntos
Metais Pesados , Poluentes do Solo , Poluentes do Solo/análise , Fertilizantes , Fósforo/farmacologia , Nitrogênio/farmacologia , Biodegradação Ambiental , Metais Pesados/análise , Solo , Plantas
7.
Int Tax Public Financ ; 29(4): 890-921, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34566261

RESUMO

In this paper, we estimate short- and long-term tax buoyancy for 44 sub-Saharan African (SSA) countries during 1980-2017 using time series and panel techniques. We find that the long-term tax buoyancy is either one or slightly above one for most SSA countries. Fragile states have a lower short-term tax buoyancy reflecting their institutional weaknesses. Short-term buoyancy of personal income tax is significantly less than one. Both short- and long-run tax responses are lower than those reported in previous cross-country studies, which can be interpreted as a reduced power of both automatic stabilization in the short run and fiscal sustainability in the long run. We find that central government debt and shadow economy exert a downward pressure on tax buoyancy. An important implication of these results is that the current tax systems in SSA would not be able to generate domestic revenues to the extent needed for financing the Sustainable Development Goals (SDGs).

8.
Crime Law Soc Change ; 78(3): 241-270, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35368408

RESUMO

It is virtually impossible to accurately measure employee theft across the casino industry using official statistics. In this paper, we use the self-report method for measuring crime to (a) estimate the prevalence, incidence, seriousness, and versatility of occupational offending in casinos in Macau, China-the largest casino gambling location in the world; and (b) identify characteristics which correlate with that offending. One in seven employees in our sample (14%; 38 out of 281) reported engaging in at least one of six offenses (theft in the workplace, falsification of documents, computer fraud, bribe offering, bribe accepting, and white-collar exploitation) in the 12 months prior to their survey response. The great majority of active offenders specialized in crime type: 61% of the active offenders in our sample (23 out of 38) committed just one of the six occupational crimes. Criminal "specialization" notwithstanding, offenders committed their crimes relatively frequently; occupational crimes were particularly costly to casinos in the long run; and these offenses varied in their severity and extent depending on crime type. Demographic characteristics of casino employees-in particular, male gender, occupational position, work schedule, and work-related experience-were associated with whether an employee engaged in workplace crime. Regarding psychological and lifestyle characteristics of employees, only financial pressure and gambling behavior were significantly related to occupational offending. Given that casinos are subject to high levels of surveillance relative to other places of employment, criminal motivation, and not just opportunity, could matter in terms of crimes committed by workers in the gaming industry.

9.
Carcinogenesis ; 42(8): 1100-1109, 2021 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-34117865

RESUMO

Uncontrolled activation of the Hedgehog (Hh) signaling pathway, operating through GLI transcription factors, plays a central role in the pathogenesis of cutaneous basal cell carcinoma and contributes to the development of several malignancies arising in extracutaneous sites. We now report that K5-tTA;tetO-Gli2 bitransgenic mice develop distinctive epithelial tumors within their jaws. These tumors consist of large masses of highly proliferative, monomorphous, basaloid cells with scattered foci of keratinization and central necrosis, mimicking human basaloid squamous cell carcinoma (BSCC), an aggressive upper aerodigestive tract tumor. Like human BSCC, these tumors express epidermal basal keratins and differentiation-specific keratins within squamous foci. Mouse BSCCs express high levels of Gli2 and Hh target genes, including Gli1 and Ptch1, which we show are also upregulated in a subset of human BSCCs. Mouse BSCCs appear to arise from distinct epithelial sites, including the gingival junctional epithelium and epithelial rests of Malassez, a proposed stem cell compartment. Although Gli2 transgene expression is restricted to epithelial cells, we also detect striking alterations in bone adjacent to BSCCs, with activated osteoblasts, osteoclasts and osteal macrophages, indicative of active bone remodeling. Gli2 transgene inactivation resulted in rapid BSCC regression and reversal of the bone remodeling phenotype. This first-reported mouse model of BSCC supports the concept that uncontrolled Hh signaling plays a central role in the pathogenesis of a subset of human BSCCs, points to Hh/GLI2 signaling as a potential therapeutic target and provides a powerful new tool for probing the mechanistic underpinnings of tumor-associated bone remodeling.


Assuntos
Remodelação Óssea , Carcinoma de Células Escamosas/patologia , Proteínas Hedgehog/metabolismo , Proteínas Nucleares/metabolismo , Neoplasias Cutâneas/patologia , Proteína Gli2 com Dedos de Zinco/metabolismo , Animais , Carcinoma de Células Escamosas/metabolismo , Humanos , Camundongos , Camundongos Transgênicos , Neoplasias Cutâneas/metabolismo
10.
J Insect Sci ; 21(5)2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34581410

RESUMO

RNAi is an effective tool for gene function analysis and a promising strategy to provide environmentally friendly control approaches for pathogens and pests. Recent studies support the utility of bacterium-mediated RNAi as a cost-effective method for gene function study and a suitable externally applied delivery mechanism for pest control. Here, we developed a bacterium-mediated RNAi system in Spodoptera frugiperda based on four target genes, specifically, Chitinase (Sf-CHI), Chitin synthase B (Sf-CHSB), Sugar transporter SWEET1 (Sf-ST), and Hemolin (Sf-HEM). RNAi conducted by feeding larvae with bacteria expressing dsRNAs of target genes or injecting pupae and adults with bacterially synthesized dsRNA induced silencing of target genes and resulted in significant negative effects on growth and survival of S. frugiperda. However, RNAi efficiency and effects were variable among different target genes and dsRNA delivery methods. Injection of pupae with dsCHI and dsCHSB induced a significant increase in wing malformation in adults, suggesting that precise regulation of chitin digestion and synthesis is crucial during wing formation. Injection of female moths with dsHEM resulted in lower mating, fecundity, and egg hatching, signifying a critical role of Sf-HEM in the process of egg production and/or embryo development. Our collective results demonstrate that bacterium-mediated RNAi presents an alternative technique for gene function study in S. frugiperda and a potentially effective strategy for control of this pest, and that Sf-CHI, Sf-CHSB, Sf-ST, and Sf-HEM encoding genes can be potent targets.


Assuntos
Interferência de RNA , RNA de Cadeia Dupla/farmacologia , Spodoptera , Animais , Bactérias/genética , Quitinases/efeitos dos fármacos , Quitinases/genética , Fertilidade/efeitos dos fármacos , Genes de Insetos/efeitos dos fármacos , Imunoglobulinas/efeitos dos fármacos , Imunoglobulinas/genética , Proteínas de Insetos/efeitos dos fármacos , Proteínas de Insetos/genética , Larva/efeitos dos fármacos , Larva/genética , Larva/fisiologia , Controle Biológico de Vetores , Pupa/efeitos dos fármacos , Pupa/genética , Pupa/fisiologia , Reprodução/efeitos dos fármacos , Spodoptera/efeitos dos fármacos , Spodoptera/genética , Spodoptera/fisiologia
11.
Small ; 16(25): e2002210, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32452633

RESUMO

The widely used route of high-temperature pyrolysis for transformation of Prussian blue analogs (PBAs) to functional nanomaterials leads to the fast removal of CN- ligands, and thus the formation of large metal aggregates and the loss of porous structures inside PBAs. Here, a controllable pyrolysis route at low temperature is reported for retaining the confined effect of CN- ligands to metal cations during the whole pyrolysis process, thereby preparing high-surface-area cubes comprising disordered bimetallic oxides (i.e., Co3 O4 and Fe2 O3 ) nanoparticles. The disordered structure of Co3 O4 enables the exposure of abundant oxygen vacancies. Notably, for the first time, it is found that the in situ generated CoOOH during the oxygen evolution reaction (OER) can inherit the oxygen vacancies of pristine Co3 O4 (i.e., before OER), and such CoOOH with abundant oxygen vacancies adsorbs two - OH in the following Co3+ to Co4+ for markedly promoting OER. However, during the similar step, the ordered Co3 O4 with less oxygen vacancies only involves one - OH, resulting in the additional overpotentials for adsorbing - OH. Consequently, with high surface area and disordered Co3 O4 , the as-synthesized electrocatalysts have a low potential of 237 mV at 10 mA cm-2 , surpassing most of reported electrocatalysts.

12.
J Synchrotron Radiat ; 27(Pt 1): 176-184, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31868750

RESUMO

Cryogenic soft X-ray tomography (Cryo-SXT) is ideally suitable to image the 3D sub-cellular architecture and organization of cells with high resolution in the near-native preservation state. Cryogenic fluorescence microscopy (Cryo-FM) can determine the location of a molecule of interest that has been labeled with a fluorescent tag, thus revealing the function of the cells. To understand the relations between the sub-cellular architecture and the function of cells, correlative Cryo-SXT and Cryo-FM was applied. This method required the matching of images of different modalities, and the accuracy of the matching is important. Here, a precise correlative method of Cryo-SXT and Cryo-FM is introduced. The capability of matching images of different modalities with high resolution was verified by simulations and practical experiments, and the method was used to identify vacuoles and mitochondria.


Assuntos
Imageamento Tridimensional/métodos , Microscopia Confocal/métodos , Microscopia de Fluorescência/métodos , Organelas/ultraestrutura , Microtomografia por Raio-X/métodos , Animais , Criopreservação , Marcadores Fiduciais , Corantes Fluorescentes , Mastócitos/ultraestrutura , Microesferas , Mitocôndrias/ultraestrutura , Schizosaccharomyces/ultraestrutura , Vacúolos/ultraestrutura
13.
Chemistry ; 26(18): 3930-3942, 2020 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-31347217

RESUMO

Recently, nonmetal doping has exhibited its great potential for boosting the hydrogen evolution reaction (HER) of transition-metal (TM)-based electrocatalysts. To this end, this work overviews the recent achievements made on the design and development of the nonmetal-doped TM-based electrocatalysts and their performance for the HER. It is also shown that by rationally doping nonmetal elements, the electronic structures of TM-based electrocatalysts can be effectively tuned and in turn the Gibbs free energy of the TM for adsorption of H* intermediates (ΔGH* ) optimized, consequently enhancing the intrinsic activity of TM-based electrocatalysts. Notably, we highlight that concurrently doping two nonmetal elements can continuously and precisely regulate the electronic structures of the TM, thereby maximizing the activity for HER. Moreover, nonmetal doping also accounts for enhancing the physical properties of the TM (i.e. surface area). Therefore, nonmetal doping is a robust strategy for simultaneous regulation of the chemical and physical features of the TM.

14.
J Clin Lab Anal ; 34(4): e23131, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31777102

RESUMO

BACKGROUND: Emerging reports demonstrated that PIWI-interacting RNAs (piRNAs) played an indispensable role in tumorigenesis. However, it still remains elusive whether piR-1245 in gastric juice specific in stomach could be employed as a biomarker for gastric cancer (GC). The present work is aiming at exploring the possibility of piR-1245 in gastric juice as a potential marker to judge for diagnosis and prognosis of gastric cancer. METHODS: Gastric juice was collected from 66 GC patients and 66 healthy individuals. Quantitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR) was employed to measure the levels of piR-1245 expression. Then, the pattern of piR-1245 expression in gastric juice was determined between GC patients and healthy individuals. A receiver operating characteristic (ROC) curve was constructed for distinguishing GC from healthy individuals. RESULTS: Gastric juice piR-1245 levels in GC were higher than those of controls (P < .0001). The value of area under ROC (AUC) was 0.885 (sensitivity, 90.9%; specificity, 74.2%; 95% confidence interval, 0.8286 to 0.9414). High gastric juice piR-1245 expression was signally correlated with tumor size (P = .013) and TNM stage (P = .001). GC patients with high piR-1245 expression in gastric juice exerted a poorer overall survival (OS) (P = .0152) and progression-free survival (PFS) (P = .013). COX regression analysis verified that gastric juice piR-1245 expression was an independent prognostic risk variable for OS (P < .05). CONCLUSIONS: The current study suggested that piR-1245 in gastric juice had the potential to be a useful biomarker for GC detection and prognosis prediction.


Assuntos
Biomarcadores Tumorais/genética , Suco Gástrico/metabolismo , RNA Interferente Pequeno/genética , Neoplasias Gástricas/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Prognóstico , RNA Interferente Pequeno/metabolismo , Curva ROC , Neoplasias Gástricas/diagnóstico , Neoplasias Gástricas/patologia , Análise de Sobrevida
15.
Psychiatr Psychol Law ; 27(4): 558-577, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33679198

RESUMO

Considerable empirical research has shown that work-family conflict has a negative effect on the job satisfaction and organizational commitment of United States correctional staff. This study is the first to examine the effect of work-family conflict on job satisfaction and organizational commitment for staff at Chinese prisons. Findings from ordinary least squares (OLS) regression analyses indicated that strain-based conflict, behavior-based conflict and family-on-work conflict had negative effects on the job satisfaction of Chinese prison staff. Also, strain-based conflict and behavior-based conflict had negative effects on organizational commitment. Overall, the results support the conclusion that work-family conflict was generally perceived as stressful by Chinese prison staff and negatively impacted their job satisfaction and organizational commitment, as has been found among United States staff.

16.
Angew Chem Int Ed Engl ; 59(43): 19054-19059, 2020 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-32686303

RESUMO

Previous density-functional theory (DFT) calculations show that sub-nanometric Cu clusters (i.e., 13 atoms) favorably generate CH4 from the CO2 reduction reaction (CO2 RR), but experimental evidence is lacking. Herein, a facile impregnation-calcination route towards Cu clusters, having a diameter of about 1.0 nm with about 10 atoms, was developed by double confinement of carbon defects and micropores. These Cu clusters enable high selectivity for the CO2 RR with a maximum Faraday efficiency of 81.7 % for CH4 . Calculations and experimental results show that the Cu clusters enhance the adsorption of *H and *CO intermediates, thus promoting generation of CH4 rather than H2 and CO. The strong interactions between the Cu clusters and defective carbon optimize the electronic structure of the Cu clusters for selectivity and stability towards generation of CH4 . Provided here is the first experimental evidence that sub-nanometric Cu clusters facilitate the production of CH4 from the CO2 RR.

17.
J Am Chem Soc ; 141(32): 12717-12723, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31348650

RESUMO

Electrocatalytic reduction reaction of CO2 (CO2RR) is an effective way to mitigate energy and environmental issues. However, very limited catalysts are capable of converting CO2 resources into high-value products such as hydrocarbons or alcohols. Herein, we first propose a facile strategy for the large-scale synthesis of isolated Cu decorated through-hole carbon nanofibers (CuSAs/TCNFs). This CuSAs/TCNFs membrane has excellent mechanical properties and can be directly used as cathode for CO2RR, which could generate nearly pure methanol with 44% Faradaic efficiency in liquid phase. The self-supporting and through-hole structure of CuSAs/TCNFs greatly reduces the embedded metal atoms and produces abundant efficient Cu single atoms, which could actually participate in CO2RR, eventually causing -93 mA cm-2 partial current density for C1 products and more than 50 h stability in aqueous solution. According to DFT calculations, Cu single atoms possess a relatively higher binding energy for *CO intermediate. Therefore, *CO could be further reduced to products like methanol, instead of being easily released from the catalyst surface as CO product. This report may benefit the design of efficient and high-yield single-atom catalysts for other electrocatalytic reactions.

18.
J Synchrotron Radiat ; 26(Pt 5): 1808-1814, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31490173

RESUMO

Transmission X-ray microscopes (TXMs) have become one of the most powerful tools for imaging 3D structures of nano-scale samples using the computed tomography (CT) principle. As a major error source, sample jitter caused by mechanical instability of the rotation stage produces shifted 2D projections, from which reconstructed images contain severe motion artifacts. In this paper, a jitter correction algorithm is proposed, that has high accuracy and computational efficiency for TXM experiments with or without nano-particle markers. Geometric moments (GMs) are measured on segmented projections for each angle and fitted to sinusoidal curves in the angular direction. Sample jitter is estimated from the difference between the measured and the fitted GMs for image correction. On a digital phantom, the proposed method removes jitter errors at different noise levels. Physical experiments on chlorella cells show that the proposed GM method achieves better spatial resolution and higher computational efficiency than the re-projection method, a state-of-the-art algorithm using iterative correction. It even outperforms the approach of manual alignment, the current gold standard, on faithfully maintaining fine structures on the CT images. Our method is practically attractive in that it is computationally efficient and lowers experimental costs in current TXM studies without using expensive nano-particles markers.


Assuntos
Aumento da Imagem/métodos , Imageamento Tridimensional , Microscopia Eletrônica de Transmissão , Tomografia Computadorizada por Raios X , Algoritmos , Artefatos , Simulação por Computador , Imagens de Fantasmas
19.
World J Surg Oncol ; 17(1): 106, 2019 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-31208415

RESUMO

BACKGROUND: To retrospectively analyze the tumor resection method used in 20 patients with clavicular tumors and evaluate its clinical efficacy. METHODS: A total of 9 patients with clavicular benign tumors underwent intracapsular resection, and 11 patients with clavicular malignant tumors underwent tumor resection from May 2012 to May 2017. Of the 11 patients, 5 underwent clavicular reconstruction using the plate-cement complex. Surgical efficacy was assessed using the Musculoskeletal Tumor Society, Constant-Murley, and American Shoulder and Elbow Surgeons shoulder outcome scores preoperatively until 12 months postoperatively. RESULTS: The average duration of follow-up care was 33.7 (12-71) months. Of the 20 patients, 3 patients died, 3 survived with tumor recurrence or metastasis, and 14 survived with no tumor recurrence. Among the 5 patients who underwent resection of malignant clavicular tumors and reconstruction, 2 underwent a re-operation because of a loose screw and plate displacement. In the functional assessment of the shoulder joint, patients with benign and malignant clavicular tumors showed significantly higher scores postoperatively compared with preoperative scores. For malignant clavicular tumors, no significant improvement was observed when comparing the non-reconstruction and reconstruction groups. CONCLUSIONS: Surgery is an optimal treatment for clavicular tumors. In patients with benign clavicular tumors, simple intracapsular resection can achieve a satisfactory prognosis. Reconstruction of a clavicular defect after resection of a clavicular malignant tumor is not recommended.


Assuntos
Neoplasias Ósseas/cirurgia , Clavícula/cirurgia , Recidiva Local de Neoplasia/cirurgia , Adolescente , Adulto , Neoplasias Ósseas/patologia , Criança , Pré-Escolar , Clavícula/patologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida , Adulto Jovem
20.
J Insect Sci ; 19(3)2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31115473

RESUMO

Recent studies on polyandry evolution have revolutionized our understanding of sexual selection. Therefore, study on traits in females, such as sensory perception and remating strategies, is expected to disclose a greater role of sexual selection in female evolution. Here, we tested how bodyweights of both sexes affected female and male remating behavior in Spodoptera litura (Fabricius, 1775) (Lepidoptera: Noctuidae). Results show most (74.4%; unmated virgin females may be sexually immature) females and males mated the first time in the second scotophase after eclosion. In the subsequent scotophase, 41.9% once-mated females and 94.1% once-mated males mated the second time with a novel virgin mate. Analyses indicate that female remating probability significantly increased with the increase of her own and the second male's bodyweight but decreased with the increase of the first male's bodyweight, while bodyweights of both sexes have no significant effect on male remating probability. Considering the nature of the low level of polyandry (two times on average) and last male precedence in S. litura, we propose that 1) females are more choosy when remating, from which females will benefit indirectly by sequential mate comparison and remate to replace sperm from the previous mates with those from higher quality mates, and 2) males will generally like to remate with any possible females, from which males will gain direct benefit by siring more offspring. The outcome of polyandry rate is likely to be the result of male investment × female choice interactions.


Assuntos
Peso Corporal , Comportamento Sexual Animal , Spodoptera/fisiologia , Animais , Feminino , Masculino
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