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1.
BMC Genomics ; 23(1): 37, 2022 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-34996356

RESUMO

BACKGROUND: Advances in DNA sequencing technologies have transformed our capacity to perform life science research, decipher the dynamics of complex soil microbial communities and exploit them for plant disease management. However, soil is a complex conglomerate, which makes functional metagenomics studies very challenging. RESULTS: Metagenomes were assembled by long-read (PacBio, PB), short-read (Illumina, IL), and mixture of PB and IL (PI) sequencing of soil DNA samples were compared. Ortholog analyses and functional annotation revealed that the PI approach significantly increased the contig length of the metagenomic sequences compared to IL and enlarged the gene pool compared to PB. The PI approach also offered comparable or higher species abundance than either PB or IL alone, and showed significant advantages for studying natural product biosynthetic genes in the soil microbiomes. CONCLUSION: Our results provide an effective strategy for combining long and short-read DNA sequencing data to explore and distill the maximum information out of soil metagenomics.


Assuntos
Metagenoma , Solo , Sequenciamento de Nucleotídeos em Larga Escala , Metagenômica , Análise de Sequência de DNA
2.
Cell Death Differ ; 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34974534

RESUMO

MORC family CW-type zinc finger 2 (MORC2) is a newly identified chromatin-remodeling enzyme involved in DNA damage response and gene transcription, and its dysregulation has been linked with Charcot-Marie-Tooth disease, neurodevelopmental disorder, and cancer. Despite its functional importance, how MORC2 is regulated remains enigmatic. Here, we report that MORC2 is O-GlcNAcylated by O-GlcNAc transferase (OGT) at threonine 556. Mutation of this site or pharmacological inhibition of OGT impairs MORC2-mediated breast cancer cell migration and invasion in vitro and lung colonization in vivo. Moreover, transforming growth factor-ß1 (TGF-ß1) induces MORC2 O-GlcNAcylation through enhancing the stability of glutamine-fructose-6-phosphate aminotransferase (GFAT), the rate-limiting enzyme for producing the sugar donor for OGT. O-GlcNAcylated MORC2 is required for transcriptional activation of TGF-ß1 target genes connective tissue growth factor (CTGF) and snail family transcriptional repressor 1 (SNAIL). In support of these observations, knockdown of GFAT, SNAIL or CTGF compromises TGF-ß1-induced, MORC2 O-GlcNAcylation-mediated breast cancer cell migration and invasion. Clinically, high expression of OGT, MORC2, SNAIL, and CTGF in breast tumors is associated with poor patient prognosis. Collectively, these findings uncover a previously unrecognized mechanistic role for MORC2 O-GlcNAcylation in breast cancer progression and provide evidence for targeting MORC2-dependent breast cancer through blocking its O-GlcNAcylation.

3.
J Colloid Interface Sci ; 608(Pt 1): 158-163, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34626963

RESUMO

Herein, Cu2S as the outer shell is grown on CdS nanorods (NRs) to construct rod-shell nanostructures (CdS/Cu2S) by a rapid, scalable and facile cation exchange reaction. The CdS NRs are firstly synthesized by a hydrothermal route, in which thiourea as the precursor of sulfur and ethylenediamine (EDA) as the solvent. And then, the outer shells of CdS NRs are successfully exchanged by Cu2S via a cation exchange reaction. The obtained CdS/Cu2S rod-shell NRs exhibit much enhanced activity of hydrogen production (640.95 µmol h-1 g-1) in comparison with pure CdS NRs (74.1 µmol h-1 g-1) and pure Cu2S NRs (0 µmol h-1 g-1). The enhanced photocatalytic activity of CdS/Cu2S rod-shell NRs owns to the following points: i) the photogenerated electrons generated by CdS quickly migrate to Cu2S without any barrier due to rod-shell structure by the in-situ cation exchange reaction, a decreased carrier recombination is achieved; ii) Cu2S as outer shells broaden the light absorption range of CdS/Cu2S rod-shell NRs into visible or even NIR light, which can produce more electrons and holes. This work inspires people to further study the rod-shell structured photocatalyst through the cation exchange strategy to further solar energy conversion.


Assuntos
Compostos de Cádmio , Nanoestruturas , Catálise , Cátions , Humanos , Hidrogênio
4.
Angiology ; 73(1): 60-67, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34109809

RESUMO

The prognostic value of high-sensitivity C-reactive protein (hsCRP) in complex coronary artery disease has not been fully established. We aimed to determine the association between hsCRP and long-term outcomes in elderly patients with 3-vessel disease (TVD). From April 2004 to February 2011, 3069 patients aged ≥65 years with TVD were consecutively enrolled and received medical treatment alone, percutaneous coronary intervention, or coronary artery bypass grafting. The patients were divided into 2 groups according to their hsCRP levels: <3.00 mg/L (62.1%) and ≥3.00 mg/L (37.9%). The mean age was 71 ± 4 years. The high hsCRP group had more risk factors and more frequently received conservative treatment than the low hsCRP group. During a median follow-up period of 6.2 years, elevated hsCRP was significantly associated with increased all-cause death (19.5% vs 29.6%, P < .001), cardiac death (9.4% vs 15.2%, P = .001), and major adverse cardiovascular and cerebrovascular events (34.1% vs 42.5%, P = .001). Multivariable Cox regression analyses revealed that hsCRP was an independent predictor for all of these events. Combining hsCRP with Synergy between PCI with TAXUS and Cardiac Surgery score II further improved the predictive power of the score. The relationship between hsCRP and mortality was relatively consistent across subgroups. Overall, hsCRP could prove useful for risk prediction in elderly patients.

5.
Nanoscale ; 14(2): 250-262, 2022 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-34931213

RESUMO

Inspired by the alveolar configuration, an alveoli-like ZSM-5 and the corresponding platinum encapsulated nanocomposite (Pt@PZ5) were fabricated via a dual-template method and a controlled selective desilication-recrystallization strategy. The dimensions of the central cavity, interconnected zeolitic vesicles, and mesoporous shell could be tuned by adjusting the synthesis parameters, as verified by scanning electron microscopy, transmission electron microscopy, nitrogen physisorption investigations, X-ray photoelectron spectroscopy, and X-ray diffraction techniques. Thanks to these properties and merits, the alveoli-like Pt@PZ5 showed the highest catalytic performance with excellent stability, obtaining 100% benzene conversion at 180 °C. Adsorption experiments combined with a finite-element simulation study uncovered that the alveolar architecture could expedite the accumulation of reactants and boost mass transfer; the conversion of intermediates in the voids could be further facilitated, giving optimal catalytic performance. Additionally, the alveolar architecture is resistant to metal sintering (5-20 nm) and leaching, even after calcination at 850 °C for 360 min. This work provides an alveolar concept into the rational design of efficient catalysts for fundamental catalytic action.

6.
J Colloid Interface Sci ; 605: 320-329, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34332407

RESUMO

Herein, we report that the phosphorous-doped 1 T-MoS2 as co-catalyst decorated nitrogen-doped g-C3N4 nanosheets (P-1 T-MoS2@N-g-C3N4) are prepared by the hydrothermal and annealing process. The obtained P-1 T-MoS2@N-g-C3N4 composite presents an enhanced photocatalytic N2 reduction rate of 689.76 µmol L-1 g-1h-1 in deionized water without sacrificial agent under simulated sunlight irradiation, which is higher than that of pure g-C3N4 (265.62 µmol L-1 g-1h-1), 1 T-MoS2@g-C3N4 (415.57 µmol L-1 g-1h-1), 1 T-MoS2@N doped g-C3N4 (469.84 µmol L-1 g-1h-1), and P doped 1 T-MoS2@g-C3N4 (531.24 µmol L-1 g-1h-1). In addition, compared with pure g-C3N4 NSs (2.64 mmol L-1 g-1h-1), 1 T-MoS2@g-C3N4 (4.98 mmol L-1 g-1h-1), 1 T-MoS2@N doped g-C3N4 (6.21 mmol L-1 g-1h-1), and P doped 1 T-MoS2@g-C3N4 (9.78 mmol L-1 g-1h-1), P-1 T-MoS2@N-g-C3N4 (11.12 mmol L-1 g-1h-1) composite also shows a significant improvement for photocatalytic N2 fixation efficiency in the sacrificial agent (methanol). The improved photocatalytic activity of P-1 T-MoS2@N-g-C3N4 composite is ascribed to the following advantages: 1) Compared to pure g-C3N4, P-1 T-MoS2@N-g-C3N4 composite shows higher light absorption capacity, which can improve the utilization rate of the catalyst to light; 2) The P doping intercalation strategy can promote the conversion of 1 T phase MoS2, which in turn in favor of photogenerated electron transfer and reduce the recombination rate of carriers; 3) A large number of active sites on the edge of 1 T-MoS2 and the existence of N doping in g-C3N4 contribute to photocatalytic N2 fixation.

7.
Chemosphere ; 292: 133446, 2021 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-34968510

RESUMO

A zeolitic cage was introduced and rationally fabricated by encapsulating Pt nanoparticles (NPs) in hollow ZSM-5, a nanomaterial with a cavity and porous shell, for efficient catalytic oxidation of benzene. The structure and formation of the zeolitic cage were systematically investigated and characterized using transmission electron microscopy, nitrogen sorption investigations, X-ray photoelectron spectroscopy, nuclear magnetic resonance spectroscopy, and X-ray diffraction. The obtained hollow 0.2 Pt@ZSM-5 exhibited a comparable low-temperature catalytic activity with 0.5Pt/ZSM-5 with T90 value of 178 °C. Various characterization techniques combined with adsorption experiments uncover the tremendous role of the zeolitic cage in the catalytic activity toward benzene oxidation. The porous shell prevented benzene dilution and the acidity originating from the hollow interior of ZSM-5 promoted the storage of benzene, thereby forming a high local concentration of benzene around Pt NPs, resulting in excellent catalytic performance. These findings provide valuable insights into the rational design of efficient catalysts for the catalytic oxidation of volatile organic compounds.

8.
Int J Infect Dis ; 115: 245-255, 2021 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-34910955

RESUMO

BACKGROUND: The aim of this study was to evaluate the long-term sequelae and cognitive profiles resulting from severe hand, foot, and mouth disease (HFMD) with central nervous system (CNS) involvement. METHODS: 294 HFMD cases were included in a retrospective follow-up study. Physical examinations were conducted. The Chinese Wechsler Preschool and Primary Scale of Intelligence, Fourth Edition (WPPSI-IV) was used to assess intelligence. RESULTS: 58 mild HFMD cases and 99 severe HFMD cases with mild CNS involvement did not present any neurological sequelae. In comparison, the sequelae incidence for severe HFMD with more severe CNS complications was 50.0%. The proportion of full-scale intelligence quotient (FSIQ) impairment was 45.0%. In the 2:6-3:11 age group, severe HFMD with more severe CNS complications and lower maternal education level were risk factors for verbal comprehension disorder. Urban-rural residence and lower paternal education level were risk factors for FSIQ disorder. Furthermore, in the 4:0-6:11 age group, severe HFMD with more severe CNS complication was a risk factor for visual spatial disorder and fluid reasoning disorder. Lower paternal education level was a risk factor for FSIQ disorder. CONCLUSION: Early assessment and intervention among severe HFMD patients with more severe CNS involvement at a very young age will prove beneficial for their future performance.

9.
Small Methods ; 5(12): e2101302, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34928034

RESUMO

Thermal management plays an important role in miniaturized and integrated nanoelectronic devices, where finding ways to enable efficient heat-dissipation can be critical. 2D materials, especially graphene and hexagonal boron nitride (h-BN), are generally regarded as ideal materials for thermal management due to their high inherent thermal conductivity. In this paper, a new method is reported, which can be used to characterize thermal transport in 2D materials. The separation of pumping from detection can obtain the temperature at different distances from the heat source, which makes it possible to study the heat distribution of 2D materials. Using this method, the thermal conductivity of graphene and molybdenum disulfide is measured, and the thermal diffusion for different shapes of graphene is explored. It is found that thermal transport in graphene changes when the surrounding environment changes. In addition, thermal transport is restricted at the boundary. These processes are accurately simulated using the finite element method, and the simulated results agree well with the experiment. Furthermore, by depositing a layer of h-BN on graphene, the heat-dissipation characteristics of graphene become tunable. This study introduces and describes a new method to investigate and optimize thermal management in 2D materials.

10.
Food Chem ; : 131577, 2021 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-34819246

RESUMO

The impact of chiral tebuconazole on the flavor and appearance of Merlot and Cabernet Sauvignon wines were systematically studied. Gas chromatography-ion mobility spectrometry and headspace-solid phase microextraction coupled with gas chromatography mass spectrometry qualitatively and quantitatively identified the flavor components, and a photographic colorimeter was used for color attribute analysis. Tebuconazole enantiomers had different effects on the flavor and appearance of young wines, especially R-tebuconazole. The flavor differences were mainly manifested in fruity and floral characteristics of the wine due to changes in the concentrations of acids, alcohols, and esters; R-tebuconazole alters the concentrations of key flavor compounds to the greatest extent. Tebuconazole treatment changes the color of young wines, with the final red shade of wine being control group > rac-tebuconazole ≥ S-tebuconazole > R-tebuconazole. Since chiral tebuconazole negatively alters wine, grapes treated with chiral pesticides should be subject to stricter quality control during processing.

11.
Small ; : e2105246, 2021 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-34741426

RESUMO

Electrocatalytic CO2 reduction reaction (CO2 RR) toward formate production can be operated under mild conditions with high energy conversion efficiency while migrating the greenhouse effect. Herein, an integrated 3D open network of interconnected bismuthene arrays (3D Bi-ene-A/CM) is fabricated via in situ electrochemically topotactic transformation from BiOCOOH nanosheet arrays supported on the copper mesh. The resulted 3D Bi-ene-A/CM consists of 2D atomically thin metallic bismuthene (Bi-ene) in the form of an integrated array superstructure with a 3D interconnected and open network, which harvests the multiple structural advantages of both metallenes and self-supported electrodes for electrocatalysis. Such distinctive superstructure affords the maximized quantity and availability of the active sites with high intrinsic activity and superior charge and mass transfer capability, endowing the catalyst with good CO2 RR performance for stable formate production with high Faradaic efficiency (≈90%) and current density (>300 mA cm-2 ). Theoretical calculation verifies the superior intermediate stabilization of the dominant Bi plane during CO2 RR. Moreover, by further coupling anodic methanol oxidation reaction, an exotic electrolytic system enables highly energy-efficient and value-added pair-electrosynthesis for concurrent formate production at both electrodes, achieving substantially improved electrochemical and economic efficiency and revealing the feasibility for practical implementation.

12.
Matter ; 4(9): 2886-2901, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34746749

RESUMO

Mechanical deformation of human skin provides essential information about human motions, muscle stretching, vocal fold vibration, and heart rates. Monitoring these activities requires the measurement of strains at different levels. Herein, we report a wearable wide-range strain sensor based on conducting polymer poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS). A bioinspired bilayer structure was constructed to enable a wide-range strain sensing (1%~100%). Besides, hydrogel was chosen as the biological- and mechanical-compatible interface layer with the human skin. Finally, we demonstrated that the strain sensor is capable of monitoring various strain-related activities, including subtle skin deformation (pulse and phonation), mid-level body stretch (swallowing and facial expressions), and substantial joint movement (elbow bending).

13.
J Colloid Interface Sci ; 608(Pt 2): 1229-1237, 2021 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-34749134

RESUMO

Improving the efficiency of photogenerated carrier separation is essential for photocatalytic N2 fixation. Herein, the 2D semi-metal 1T'-MoS2 was uniformly distributed in g-C3N4 nanocages (CNNCs) by a hydrothermal method, and the 1T'-MoS2/CNNC composite was obtained. 1T'-MoS2 as a co-catalyst can promote the transfer of electrons, improve the separation efficiency of photogenerated carriers, and also increase the number of effective active sites. In addition, the unique nanocage morphology of CNNCs is conducive to the scattering and reflection of incident light and improves the light absorption capacity. Therefore, the optimized 1T'-MoS2/CNNC composite (5 wt%) shows a significantly improved photocatalytic N2 fixation rate (9.8 mmol L-1 h-1 g-1) and good stability, which is significantly higher than pure CNNCs (2.9 mmol L-1 h-1 g-1), Pt/CNNC (8.2 mmol L-1 h-1 g-1) and Pt/g-C3N4 nanosheet (CNNS, 6.3 mmol L-1 h-1 g-1). This work guides guidance for the design of green and efficient N2 fixation photocatalysts.

14.
J Colloid Interface Sci ; 608(Pt 2): 1882-1893, 2021 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-34749141

RESUMO

Combination chemotherapy is a promising strategy for cancer treatment in clinics especially when multidrug-resistant cancer is emerging. One significant challenge remains in achieving sufficient multi-drug delivery into tumor cells to maximize the synergetic therapeutic effect, as it is hard to concentrate drugs in drug-resistant cancer. Therefore herein, metal-organic framework (MOF)-based polymer-coated hybrid nanoparticles (NPs) were devised and constructed for the co-delivery of doxorubicin and cisplatin to enhance combination therapy of multidrug-resistant cancer. The MOF@polymer nanocarrier combined the merits of high multi-drug loading capacity, physiological stability, and tumor microenvironment pH-responsiveness, facilitating simultaneous delivery of drugs into cancer cells and making the most of synergistic antitumor effect. Remarkably, this hybrid nanocarrier maintains a negative surface charge during circulation to guarantee a stable and prolonged process in vivo, and then exposes inner positive MOF after degradation of the outer polymer in the acidic tumor microenvironment to promote multi-drug release, cellular internalization, nuclear localization, and tumor penetration. In vitro and in vivo studies with drug-resistant MCF-7/ADR cancer suggested that the nanocarrier could achieve increased accumulation of drugs in solid tumors, remarkable tumor elimination results as well as minimized side effects, indicating an improved efficacy and safety of combination chemotherapy. MOF@polymer hybrid nanocarriers provide new insights into the development of stimuli-responsive co-delivery systems of multiple drugs.

15.
Appl Microbiol Biotechnol ; 105(21-22): 8517-8529, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34609525

RESUMO

Recently, cadmium (Cd) contamination in paddy soils has become a highly concerning pollution problem. Endophytic microbes in rice not only affect the plant growth but also contribute to ion absorption by the roots. Therefore, they are a promising, ecologically sound means of reducing the Cd transport from soils to shoots and grains of the plant. In this study, a Cd-resistant endophytic bacterium, named 181-22, with high Cd absorption capacity (90.8%) was isolated from the roots of rice planting in heavily Cd-contaminated paddy soils and was identified as Bacillus koreensis CGMCC 19,468. The strain significantly increased fresh weight of roots and shoots (44.4% and 42.7%) and dry weight of roots and shoots (71.3% and 39.9%) and decreased Cd content in the rice roots (12.8%), shoots (34.3%), and grains (39.1%) under Cd stress compared to uninoculated plant by colonizing rice roots via seed inoculation. Moreover, colonization of 181-22 reprogrammed rice physiology to alleviate Cd stress by increasing pigment and total protein content, regulating Cd-induced oxidative stress enzymes such as superoxide dismutase and catalase and reducing malondialdehyde. Thus, B. koreensis 181-22 has the potential to protect rice against Cd stress and can be used as a biofertilizer to bioremediate paddy soils contaminated with Cd. KEY POINTS: • Bacillus koreensis 181-22 colonized the inside of rice roots at high numbers via seed inoculation. • B. koreensis 181-22 promoted rice growth and decreased Cd accumulation in grains. • B. koreensis 181-22 regulated the physiological response to alleviated Cd stress in rice.


Assuntos
Bacillus , Oryza , Poluentes do Solo , Cádmio/análise , Cádmio/toxicidade , Raízes de Plantas/química , Solo , Poluentes do Solo/análise , Poluentes do Solo/toxicidade
16.
FASEB J ; 35(11): e21972, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34613642

RESUMO

The misalignment of eating time and the endogenous circadian rhythm impairs the body's ability to maintain homeostasis. Although it is well established that children and growing animals differ from adults in their energy metabolism and behavioral patterns, little is known about how mistimed feeding disturbs the diurnal rhythms of behavior and metabolism in children and growing diurnal animals. In this study, growing pigs (diurnal animal) were randomly assigned to the daytime-restricted feeding (DRF) and nighttime-restricted feeding (NRF) groups for 5 weeks. Compared with observations in the DRF group, NRF disrupted the diurnal rhythm of behavior and clock genes and lowered the serum ghrelin, dopamine, and serotonin levels during the daytime and nighttime. Microbiome analysis results suggested that NRF altered the diurnal rhythm and composition of the gut microbiota, and increased log-ratios of Catenibacterium:Butyrivibrio and Streptococcus:Butyrivibrio. Based on the serum proteome, the results further revealed that rhythmic and upregulated proteins in NRF were mainly involved in oxidative stress, lipid metabolism, immunity, and cancer biological pathways. Serum physiological indicators further confirmed that NRF decreased the concentration of melatonin and fibroblast growth factor 21 during the daytime and nighttime, increased the diurnal amplitude and concentrations of very-low-density lipoprotein cholesterol, triglyceride, and total cholesterol, and increased the apolipoprotein B/ApoA1 ratio, which is a marker of metabolic syndrome. Taken together, this study is the first to reveal that mistimed feeding disrupts the behavioral rhythms of growing pigs, reprograms gut microbiota composition, reduces the serum levels of hormones associated with fighting depression and anxiety, and increases the risk of lipid metabolic dysregulation.


Assuntos
Ritmo Circadiano , Comportamento Alimentar , Metabolismo dos Lipídeos , Animais , Suínos
17.
Nat Commun ; 12(1): 6229, 2021 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-34711824

RESUMO

Mesenchymal stem cells adopt differentiation pathways based upon cumulative effects of mechanosensing. A cell's mechanical microenvironment changes substantially over the course of development, beginning from the early stages in which cells are typically surrounded by other cells and continuing through later stages in which cells are typically surrounded by extracellular matrix. How cells erase the memory of some of these mechanical microenvironments while locking in memory of others is unknown. Here, we develop a material and culture system for modifying and measuring the degree to which cells retain cumulative effects of mechanosensing. Using this system, we discover that effects of the RGD adhesive motif of fibronectin (representative of extracellular matrix), known to impart what is often termed "mechanical memory" in mesenchymal stem cells via nuclear YAP localization, are erased by the HAVDI adhesive motif of the N-cadherin (representative of cell-cell contacts). These effects can be explained by a motor clutch model that relates cellular traction force, nuclear deformation, and resulting nuclear YAP re-localization. Results demonstrate that controlled storage and removal of proteins associated with mechanical memory in mesenchymal stem cells is possible through defined and programmable material systems.

18.
Nanomaterials (Basel) ; 11(10)2021 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-34685026

RESUMO

TiO2 has been generally studied for photocatalytic sterilization, but its antibacterial activities are limited. Herein, TiO2 nanospheres with rutile/anatase heterophase junctions are prepared by a wet chemical/annealing method. The large BET surface area and pore size are beneficial for the absorption of bacteria. The rutile/anatase heterojunctions narrow the bandgap, which enhances light absorption. The rutile/anatase heterojunctions also efficiently promote the photogenerated carriers' separation, finally producing a high yield of radical oxygen species, such as •O2- and •OH, to sterilize bacteria. As a consequence, the obtained TiO2 nanospheres with rutile/anatase heterojunctions present an improved antibacterial performance against E. coli (98%) within 3 h of simulated solar light irradiation, exceeding that of TiO2 nanospheres without annealing (amorphous) and TiO2 nanospheres annealing at 350 and 550 °C (pure anatase). Furthermore, we design a photocatalytic antibacterial spray to protect the file paper. Our study reveals that the TiO2 nanospheres with rutile/anatase heterojunctions are a potential candidate for maintaining the durability of paper in the process of archival protection.

19.
Phys Chem Chem Phys ; 23(36): 20666-20674, 2021 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-34515274

RESUMO

Recently, palladium diselenide (PdSe2) has emerged as a promising material with potential applications in electronic and optoelectronic devices due to its intriguing electronic and optical properties. The performance of the device is strongly dependent on the charge-carrier dynamics and the related hot phonon behavior. Here, we investigate the photoexcited-carrier dynamics and coherent acoustic phonon (CAP) oscillations in mechanically exfoliated PdSe2 flakes with a thickness ranging from 10.6 nm to 54 nm using time-resolved non-degenerate pump-probe transient reflection (TR) spectroscopy. The results imply that the CAP frequency is thickness-dependent. Polarization-resolved transient reflection (PRTR) measurements reveal the isotropic charge-carrier relaxation dynamics and the CAP frequency in the 10.6 nm region. In addition, the deformation potential (DP) mechanism dominates the generation of the CAP. Moreover, a sound velocity of 6.78 × 103 m s-1 is extracted from the variation of the oscillation period with the flake thickness and the delay time of the acoustic echo. These results provide insight into the ultrafast optical coherent acoustic phonon and optoelectronic properties of PdSe2 and may open new possibilities for PdSe2 applications in THz-frequency mechanical resonators.

20.
Environ Pollut ; 290: 118000, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34482244

RESUMO

During three sampling periods in 2014, systematic investigations were conducted into contamination profiles of ten organophosphate flame retardants (OPFRs) in both suspended particulate phase and water phase in the Yellow River (Henan Area). This research shows that OPFRs exist at lower concentrations in the suspended phase than in the water phase. The median concentration of 10 OPFRs (∑10OPFRs) in the suspended particulate phase was 62.5 ng/g (fluctuating from ND to 6.17 × 103 ng/g, dw), while their median concentration in the water phase was 109 ng/L (fluctuating from 35.6 to 469 ng/L). Among the selected 10 OPFRs, triethylphosphate (TEP), tris(1-chloro-2-propyl) phosphate (TCPP), and tris(2-chloroethyl) phosphate (TCEP) were the predominant compounds in the water phase (occupying 91.6% of the ∑10OPFRs), while TCPP, TCEP, and tri-o-tolyl phosphate (o-TCP) were the most common in the suspended particulate phase, accounting for 90.1% of the ∑10OPFRs. Across the three sampling periods, there was no significant seasonable variation for OPFRs either in the water phase or in the suspended particulate phase, except for TCEP and TCPP in the water phase. Compared with research findings relating to concentrations of OPFRs around China and abroad, the OPFRs of the Yellow River (Henan Area) in the water phase were at a moderate level. Suspended particles (SS) had a very important impact on the transportation of OPFRs in the studied area, with about 83.9% of ∑10OPFRs inflow attributed to SS inflow and about 81.7% of ∑10OPFRs outflow attributed to SS outflow. The total annual inflow and outflow of OPFRs were 7.72 × 104 kg and 6.62 × 104 kg in the studied area, respectively.


Assuntos
Retardadores de Chama , China , Poeira , Retardadores de Chama/análise , Organofosfatos/análise , Compostos Organofosforados/análise , Rios
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