ABSTRACT
Plant-derived exosome-like nanovesicles (ELNs) are nano-sized vesicles extracted from edible plants. Lycium ruthenicum Murray (LRM) has been gaining increasing attention due to its nutritional and medicinal value, but the ELNs in LRM has not been reported. In this study, LRM-ELNs were obtained, and the proteins, lipids, microRNAs (miRNAs) and active components in LRM tissues and LRM-ELNs was analyzed by LC-MS/MS, LC-MS, high-throughput sequencing techniques, and physical and chemical analysis. LRM-ELNs can be uptaken by PC12 cells through macropinocytosis and caveolin-mediated endocytosis primarily. Transcriptomic and western blot experiments indicate that LRM-ELNs can inhibit Aß-induced apoptosis in PC12 cells through the MAPK and PI3K/AKT signaling pathways, with miRNAs playing a crucial role. These results indicated that LRM-ELNs have the protection effect on PC12 cells and can be considered as dietary supplements for alleviating neurodegenerative diseases.
ABSTRACT
The unique spin texture of quantum states in topological materials underpins many proposed spintronic applications. However, realizations of such great potential are stymied by perturbations, such as temperature and local fields imposed by impurities and defects, that can render a promising quantum state uncontrollable. Here, we report room-temperature scanning tunneling microscopy/spectroscopy observation of interaction between Rashba states and topological surface states, which manifests local electronic structure along step edges controllable by the layer thickness of thin films. The first-principles theoretical calculation elucidates the robust Rashba states coexisting with topological surface states along the surface steps with characteristic spin textures in momentum space. Furthermore, the Rashba edge states can be switched off by reducing the thickness of a topological insulator Bi2Se3 to bolster their interaction with the hybridized topological surface states. The study unveils a manipulating mechanism of the spin textures at room temperature, reinforcing the necessity of thin film technology in controlling the quantum states.
ABSTRACT
A two-dimensional (2D) Weyl semimetal, akin to a spinful variant of graphene, represents a topological matter characterized by Weyl fermion-like quasiparticles in low dimensions. The spinful linear band structure in two dimensions gives rise to distinctive topological properties, accompanied by the emergence of Fermi string edge states. We report the experimental realization of a 2D Weyl semimetal, bismuthene monolayer grown on SnS(Se) substrates. Using spin and angle-resolved photoemission and scanning tunneling spectroscopies, we directly observe spin-polarized Weyl cones, Weyl nodes, and Fermi strings, providing consistent evidence of their inherent topological characteristics. Our work opens the door for the experimental study of Weyl fermions in low-dimensional materials.
ABSTRACT
Enterococcus faecium, Bifidobacterium, and Pediococcus acidilactici, as intestinal probiotics, have been proved to play a positive role in treating intestinal diseases, promoting growth and immune regulation in poultry. The aim of this study was to evaluate the effect of compound probiotics on growth performance, digestive enzyme activity, intestinal microbiome characteristics, as well as intestinal morphology in broiler chickens. Treatment diets with chlortetracycline and compound probiotics were used for two groups of sixty broilers each throughout the feeding process. Another group was fed the basal diet. The BW (2589.41 ± 13.10 g vs 2422.50 ± 19.08 g) and ADG (60.57 ± 0.31 g vs 56.60 ± 0.45 g) of the compound probiotics added feed treatment group were significantly increased, and the FCR was significantly decreased (P < 0.05). The supplementation of a compound probiotics enhanced the abundance of beneficial bacteria such as Lactobacillus, Faecalibacterium, and norank_f_norank_o_Clostridia_vadinBB60_group (P < 0.05), and modulated the cecal microbiota structure, thereby promoting the production of short-chain fatty acids (SCFAs) and elevating their levels (P < 0.05), particularly propionic and butyric acids. Furthermore, the administration of the compound probiotics supplements significantly enhanced the villi height, V/C ratio, and reduced the crypt depth (P < 0.05). In addition, the activity of digestive enzymes in the duodenum and jejunum was elevated (P < 0.05). Collectively, the selected compound probiotics supplemented in this experiment have demonstrated efficacy, warranting further application in practical production settings as a viable alternative to antibiotics, thereby facilitating efficient production and promoting gastrointestinal health.
ABSTRACT
We report an algorithm to identify and correct distorted wavefronts in atomic resolution scanning tunneling microscope images. This algorithm can be used to correct nonlinear in-plane distortions without prior knowledge of the physical scanning parameters, the characteristics of the piezoelectric actuator, or individual atom positions. The 2D image is first defined as a sum of sinusoidal plane waves, where a nonlinear distortion renders a curve for an otherwise ideal linear wavefront. Using the Fourier transforms of local areas of the image, the algorithm generates a wavefront vector field. The identified wavefronts are subsequently linearized for each plane wave without changing lattice orders, giving rise to distortion corrections. Our algorithm is complementary to conventional post-processing algorithms that require prior detection of real space features, which can also be used to correct nonlinear distortions in 2D images acquired by other microscopy techniques.
ABSTRACT
Pseudomonas aeruginosa is a conditional Gram-negative pathogen that produces extracellular virulence factors that can lead to bloodstream invasion, severely harm tissues, and disseminate bacteria, ultimately leading to various diseases. In this study, lactic acid bacteria (LAB) with strong antagonistic ability against P. aeruginosa were screened, and the regulatory mechanism of LAB against P. aeruginosa was evaluated. The results showed that the three selected LAB strains had strong inhibition ability on the growth, biofilm formation, and pyocyanin expression of P. aeruginosa and a promoting effect on the expression of autoinducer-2. Among them, Lactipantibacillus plantarum (Lp. plantarum) LPyang is capable of affecting the metabolic processes of P. aeruginosa by influencing metabolic substances, such as LysoPC, oxidized glutathione, betaine, etc. These results indicate that LPyang reduces the infectivity of P. aeruginosa through inhibition of its growth, biofilm formation, pyocyanin expression, and regulation of its metabolome. This study provides new insights into the antagonistic activity of Lp. plantarum LPyang against P. aeruginosa.
ABSTRACT
Lung cancer (LC) is the most frequently diagnosed cancer and is the leading cause of cancer-associated death. Serum markers that exhibit high sensitivity and specificity for LC may assist in the diagnosis and prognosis of LC. The banked serum samples from 599 individuals, including 201 healthy controls, 124 patients with benign lung diseases, and 274 LC cases, were used. The serum concentrations of biomarkers were determined by electrochemiluminescence immunoassay and chemiluminescence immunoassay. The results showed that the serum human epididymis secretory protein 4 (HE4) levels in the LC group were significantly higher than in the healthy and benign lung disease groups. The serum levels of HE4, NSE, and CYFRA21-1 were significantly higher in patients with LC compared to those in the benign lung disease group. The area under the area under the curve (AUC) of HE4 for discriminating LC from healthy controls was 0.851 (95% CI, 0.818-0.884) and 0.739 (95% CI, 0.695-0.783), 0.747 (95% CI, 0.704-0.790), 0.626 (95% CI, 0.577-0.676), and 0.700 (95% CI, 0.653-0.747) for NSE, CYFRA21-1, SCC, and ProGRP, respectively. The AUC value of the combination of serum HE4 combined with NSE, CYFRA21-1, SCC, and proGRP for cancer diagnosis was 0.896 (95% CI, 0.868-0.923). In early LC, the AUC value of HE4 for discriminating early LC from healthy controls was 0.802 (95% CI, 0.758-0.845), 0.728 (95% CI, 0.679-0.778), 0.699 (95% CI, 0.646-0.752), 0.605 (95% CI, 0.548-0.662), and 0.685 (95% CI, 0.630-0.739) for NSE, CYFRA21-1, SCC, and ProGRP, respectively. The AUC value of the combination of serum HE4 with NSE, CYFRA21-1, SCC, and proGRP for early LC was 0.867 (95% CI, 0.831-0.903). Serum HE4 is a promising LC biomarker, particularly for early-stage LC. Measuring serum HE4 levels may improve the diagnostic efficiency of LC.
ABSTRACT
The interface between 2D topological Dirac states and an s-wave superconductor is expected to support Majorana-bound states (MBS) that can be used for quantum computing applications. Realizing these novel states of matter and their applications requires control over superconductivity and spin-orbit coupling to achieve spin-momentum-locked topological interface states (TIS) which are simultaneously superconducting. While signatures of MBS have been observed in the magnetic vortex cores of bulk FeTe0.55 Se0.45 , inhomogeneity and disorder from doping make these signatures unclear and inconsistent between vortices. Here superconductivity is reported in monolayer (ML) FeTe1-y Sey (Fe(Te,Se)) grown on Bi2 Te3 by molecular beam epitaxy (MBE). Spin and angle-resolved photoemission spectroscopy (SARPES) directly resolve the interfacial spin and electronic structure of Fe(Te,Se)/Bi2 Te3 heterostructures. For y = 0.25, the Fe(Te,Se) electronic structure is found to overlap with the Bi2 Te3 TIS and the desired spin-momentum locking is not observed. In contrast, for y = 0.1, reduced inhomogeneity measured by scanning tunneling microscopy (STM) and a smaller Fe(Te,Se) Fermi surface with clear spin-momentum locking in the topological states are found. Hence, it is demonstrated that the Fe(Te,Se)/Bi2 Te3 system is a highly tunable platform for realizing MBS where reduced doping can improve characteristics important for Majorana interrogation and potential applications.
ABSTRACT
This study aimed to investigate the effects of selenium (Se)-enriched Bacillus subtilis (Se-BS) on growth performance, antioxidant capacity, immune status, and gut health in broilers. A total of 240 one-day-old Arbor Acres broilers were randomly allotted to four groups and fed with basal diet (control group), 0.30 mg/kg Se (SS group), 3 × 109 CFU/g B. subtilis (BS group), and 0.30 mg/kg Se + 3 × 109 CFU/g B. subtilis (Se-BS group) for 42 days. The results showed that Se-BS supplementation increased body weight (BW), average daily gain, the activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), and peroxidase (POD), total antioxidant capacity (T-AOC), and the contents of interleukin (IL)-2, IL-4, and immunoglobulin (Ig) G in plasma, the index and wall thickness of the duodenum, the villus height and crypt depth of the jejunum, and GPx-1 and thioredoxin reductase 1 mRNA levels in liver and intestine and decreased feed conversion ratio (FCR) and plasma malondialdehyde (MDA) content compared with the control group on day 42 (P < 0.05). Compared with groups SS and BS, Se-BS supplementation increased BW, the activities of GPx, CAT, and POD, and the contents of IL-2, IL-4, and IgG in plasma, the index and wall thickness of the duodenum, the crypt depth and secretory IgA content of the jejunum, and GPx-1 mRNA levels in liver and intestine and decreased FCR and plasma MDA content on day 42 (P < 0.05). In conclusion, Se-BS supplementation effectively improved the growth performance antioxidant capacity, immune status, and gut health of broilers.
Subject(s)
Antioxidants , Selenium , Animals , Selenium/pharmacology , Chickens , Bacillus subtilis , Dietary Supplements , Interleukin-4 , Diet/veterinary , Glutathione Peroxidase , RNA, Messenger/genetics , Animal Feed/analysisABSTRACT
Mycotoxins are ubiquitously present in feeds and raw materials and can exert toxicity on animals and humans. Therefore, mycotoxin occurrence should be monitored. We report here a multi-mycotoxin survey of feed samples in China from 2017 to 2021. Concentrations of aflatoxins, trichothecenes type B, fumonisins, and zearalenone were determined in a total of 9392 samples collected throughout China. Regional differences and year-to-year variation of mycotoxin occurrence were also assessed in new-season corn. Generally, Fusarium mycotoxins were prevalent, while mycotoxin contamination in each feed commodity showed a distinct pattern, e.g., wheat and bran were typically affected by trichothecenes type B, peanut meals were highly susceptible to aflatoxins, and finished feeds exhibited a comparatively high prevalence of all mycotoxins. In new-season corn, trichothecenes type B and fumonisins were most prevalent, with positive rates of 84.04% and 87.16%, respectively. Regions exhibited different patterns of mycotoxin occurrence. The Anhui and Jiangsu provinces of East China exhibited a high prevalence and concentrations of aflatoxins with a positive rate and a positive average of 82.61% and 103.08 µg/kg, respectively. Central China obtained high fumonisins levels of 4707.84 µg/kg. Trichothecenes type B and zearalenone occurred more frequently in temperate regions of Northeast China, and their positive rates reached 94.99% and 55.67%, respectively. In these regions, mycotoxin concentrations in new-season corn exhibited pronounced year-to-year variations and this could be due to the unusual changes of rainfall or temperature during sensitive periods of corn growing. A large fraction of new-season corn samples contained multiple mycotoxins with two to three classes (75.42%), and the most frequently observed co-contaminants were the combination of trichothecenes type B and fumonisins (73.52%). Trichothecenes type B and zearalenone concentrations were highly positively correlated with a coefficient of 0.775. In conclusion, mycotoxins contamination and co-contamination of feeds are common. Mycotoxin contamination in new-season corn exhibited regional patterns and year-to-year variations, with climate and weather conditions as determinant factors.
Subject(s)
Aflatoxins , Fumonisins , Mycotoxins , Trichothecenes , Zearalenone , Humans , Animals , Mycotoxins/analysis , Zearalenone/toxicity , Fumonisins/toxicity , Food Contamination/analysis , Animal Feed/analysis , Trichothecenes/toxicity , Aflatoxins/analysis , Zea mays , ChinaABSTRACT
Aptamers incorporating chemically modified bases can achieve superior affinity and specificity compared to natural aptamers, but their characterization remains a labor-intensive, low-throughput task. Here, we describe the "non-natural aptamer array" (N2A2) system, in which a minimally modified Illumina MiSeq instrument is used for the high-throughput generation and characterization of large libraries of base-modified DNA aptamer candidates based on both target binding and specificity. We first demonstrate the capability to screen multiple different base modifications to identify the optimal chemistry for high-affinity target binding. We next use N2A2 to generate aptamers that can maintain excellent specificity even in complex samples, with equally strong target affinity in both buffer and diluted human serum. For both aptamers, affinity was formally calculated with gold-standard binding assays. Given that N2A2 requires only minor mechanical modifications to the MiSeq, we believe that N2A2 offers a broadly accessible tool for generating high-quality affinity reagents for diverse applications.
Subject(s)
Aptamers, Nucleotide , Humans , Aptamers, Nucleotide/chemistry , Biological Assay , SELEX Aptamer TechniqueABSTRACT
Quantum materials are usually heterogeneous, with structural defects, impurities, surfaces, edges, interfaces, and disorder. These heterogeneities are sometimes viewed as liabilities within conventional systems; however, their electronic and magnetic structures often define and affect the quantum phenomena such as coherence, interaction, entanglement, and topological effects in the host system. Therefore, a critical need is to understand the roles of heterogeneities in order to endow materials with new quantum functions for energy and quantum information science applications. In this article, several representative examples are reviewed on the recent progress in connecting the heterogeneities to the quantum behaviors of real materials. Specifically, three intertwined topic areas are assessed: i) Reveal the structural, electronic, magnetic, vibrational, and optical degrees of freedom of heterogeneities. ii) Understand the effect of heterogeneities on the behaviors of quantum states in host material systems. iii) Control heterogeneities for new quantum functions. This progress is achieved by establishing the atomistic-level structure-property relationships associated with heterogeneities in quantum materials. The understanding of the interactions between electronic, magnetic, photonic, and vibrational states of heterogeneities enables the design of new quantum materials, including topological matter and quantum light emitters based on heterogenous 2D materials.
ABSTRACT
As the most difficult to control in plant disease, phytopathogenic bacteria cause huge losses to agricultural products and economy worldwide. However, the commercially available bactericides are few and enhance pathogen resistance. To alleviate this situation, 50 flavonoids were evaluated for their antibacterial activities and mechanism of action against two intractable plant bacterial pathogens. The results of bioassays showed that most of the flavonoids exhibited moderate inhibitory effects against Xanthomonas oryzae (Xo) and Xanthomonas axonopodis pv citri (Xac). Remarkably, kaempferol showed excellent antibacterial activity against Xo in vitro (EC50 = 15.91 µg/mL) and quercetin showed the best antibacterial activity against Xac in vitro (EC50 = 14.83 µg/mL), which was better than thiodiazole copper (EC50 values against Xo and Xac were 16.79 µg/mL, 59.13 µg/mL, respectively). Subsequently, in vivo antibacterial activity assay further demonstrated kaempferol exhibited a stronger control effect on bacterial infections than thiodiazole copper. Then, the preliminary antibacterial mechanism of kaempferol was investigated by ultrastructural observations, transcriptomic, qRT-PCR analysis and biochemical index determination. These results showed that kaempferol mainly exerted bacteriostatic effects at the molecular level by affecting bacterial energy metabolism, reducing pathogenicity, and leading to disruption of cellular integrity, leakage of contents and cell death eventually.
Subject(s)
Flavonoids , Kaempferols , Flavonoids/pharmacology , Kaempferols/pharmacology , Copper , Bacteria , Anti-Bacterial Agents/pharmacologyABSTRACT
Controlling the interlayer coupling in two-dimensional (2D) materials generates novel electronic and topological phases. Its effective implementation is commonly done with a transverse electric field. However, phases generated by high displacement fields are elusive in this standard approach. Here, we introduce an exceptionally large displacement field by structural modification of a model system: AB-stacked bilayer graphene (BLG) on a SiC(0001) surface. We show that upon intercalation of gadolinium, electronic states in the top graphene layers exhibit a significant difference in the on-site potential energy, which effectively breaks the interlayer coupling between them. As a result, for energies close to the corresponding Dirac points, the BLG system behaves like two electronically isolated single graphene layers. This is proven by local scanning tunneling microscopy (STM)/spectroscopy, corroborated by density functional theory, tight binding, and multiprobe STM transport. The work presents metal intercalation as a promising approach for the synthesis of 2D graphene heterostructures with electronic phases generated by giant displacement fields.
ABSTRACT
The transport of water through nanoscale capillaries/pores plays a prominent role in biology, ionic/molecular separations, water treatment and protective applications. However, the mechanisms of water and vapor transport through nanoscale confinements remain to be fully understood. Angstrom-scale pores (~2.8-6.6 Å) introduced into the atomically thin graphene lattice represent ideal model systems to probe water transport at the molecular-length scale with short pores (aspect ratio ~1-1.9) i.e., pore diameters approach the pore length (~3.4 Å) at the theoretical limit of material thickness. Here, we report on orders of magnitude differences (~80×) between transport of water vapor (~44.2-52.4 g m-2 day-1 Pa-1) and liquid water (0.6-2 g m-2 day-1 Pa-1) through nanopores (~2.8-6.6 Å in diameter) in monolayer graphene and rationalize this difference via a flow resistance model in which liquid water permeation occurs near the continuum regime whereas water vapor transport occurs in the free molecular flow regime. We demonstrate centimeter-scale atomically thin graphene membranes with up to an order of magnitude higher water vapor transport rate (~5.4-6.1 × 104 g m-2 day-1) than most commercially available ultra-breathable protective materials while effectively blocking even sub-nanometer (>0.66 nm) model ions/molecules.
Subject(s)
Graphite , Nanopores , Steam , Gases , Membranes , IonsABSTRACT
Quantum coupling in arrayed nanostructures can produce novel mesoscale properties such as electronic minibands to improve the performance of optoelectronic devices, including ultra-efficient solar cells and infrared photodetectors. Colloidal PbSe quantum dots (QDs) that self-assemble into epitaxially-fused superlattices (epi-SLs) are predicted to exhibit such collective phenomena. Here, we show the emergence of distinct local electronic states induced by crystalline necks that connect individual PbSe QDs and modulate the bandgap energy across the epi-SL. Multi-probe scanning tunneling spectroscopy shows bandgap modulation from 0.7 eV in the QDs to 1.1 eV at their necks. Complementary monochromated electron energy-loss spectroscopy demonstrates bandgap modulation in spectral mapping, confirming the presence of these distinct energy states from necking. The results show the modification of the electronic structure of a precision-made nanoscale superlattice, which may be leveraged in new optoelectronic applications.
ABSTRACT
The structures of bare Ti3C2 and functionalized Ti3C2T2 (T = O, F, H, OH) MXenes were constructed, and the effect of surface functional groups T2 (T = O, F, H, OH) on the structural, electronic, and lithium storage properties were investigated by first-principles calculations. The results show that the proximity of surface functional groups will induce some lattice distortion of Ti3C2T2 MXene. The degree of lattice distortion depends mainly on the adsorption position of functional groups and the types of surface functional groups. From the point of view of forming energy, the surface functional groups tend to be located at the CCP site. From the energy band and DOS results, the presence of surface functional groups has a significant effect on the valence band, while it has a slight impact on the conduction band. In terms of lithium storage, lithium atom adsorption starts from the HCP position for bare Ti3C2, while functionalized Ti3C2T2 starts from the CCP position. The double-layer lithium storage capacity of bare Ti3C2 and Ti3C2O2 were 639.78 mAh/g and 537.22 mAh/g, respectively. And the single-layer lithium storage capacity of Ti3C2F2 was 130.77 mAh/g.