ABSTRACT
Light-field detection measures both the intensity of light rays and their precise direction in free space. However, current light-field detection techniques either require complex microlens arrays or are limited to the ultraviolet-visible light wavelength ranges1-4. Here we present a robust, scalable method based on lithographically patterned perovskite nanocrystal arrays that can be used to determine radiation vectors from X-rays to visible light (0.002-550 nm). With these multicolour nanocrystal arrays, light rays from specific directions can be converted into pixelated colour outputs with an angular resolution of 0.0018°. We find that three-dimensional light-field detection and spatial positioning of light sources are possible by modifying nanocrystal arrays with specific orientations. We also demonstrate three-dimensional object imaging and visible light and X-ray phase-contrast imaging by combining pixelated nanocrystal arrays with a colour charge-coupled device. The ability to detect light direction beyond optical wavelengths through colour-contrast encoding could enable new applications, for example, in three-dimensional phase-contrast imaging, robotics, virtual reality, tomographic biological imaging and satellite autonomous navigation.
ABSTRACT
The pair density wave (PDW) is a superconducting state in which Cooper pairs carry centre-of-mass momentum in equilibrium, leading to the breaking of translational symmetry1-4. Experimental evidence for such a state exists in high magnetic field5-8 and in some materials that feature density-wave orders that explicitly break translational symmetry9-13. However, evidence for a zero-field PDW state that exists independent of other spatially ordered states has so far been elusive. Here we show that such a state exists in the iron pnictide superconductor EuRbFe4As4, a material that features co-existing superconductivity (superconducting transition temperature (Tc) ≈ 37 kelvin) and magnetism (magnetic transition temperature (Tm) ≈ 15 kelvin)14,15. Using spectroscopic imaging scanning tunnelling microscopy (SI-STM) measurements, we show that the superconducting gap at low temperature has long-range, unidirectional spatial modulations with an incommensurate period of about eight unit cells. Upon increasing the temperature above Tm, the modulated superconductor disappears, but a uniform superconducting gap survives to Tc. When an external magnetic field is applied, gap modulations disappear inside the vortex halo. The SI-STM and bulk measurements show the absence of other density-wave orders, indicating that the PDW state is a primary, zero-field superconducting state in this compound. Both four-fold rotational symmetry and translation symmetry are recovered above Tm, indicating that the PDW is a smectic order.
ABSTRACT
Nucleotide-binding domain and leucine-rich repeat (NLR) proteins can engage in complex interactions to detect pathogens and execute a robust immune response via downstream helper NLRs. However, the biochemical mechanisms of helper NLR activation by upstream sensor NLRs remain poorly understood. Here, we show that the coiled-coil helper NLR NRC2 from Nicotiana benthamiana accumulates in vivo as a homodimer that converts into a higher-order oligomer upon activation by its upstream virus disease resistance protein Rx. The cryo-EM structure of NbNRC2 in its resting state revealed intermolecular interactions that mediate homodimer formation and contribute to immune receptor autoinhibition. These dimerization interfaces have diverged between paralogous NRC proteins to insulate critical network nodes and enable redundant immune pathways, possibly to minimise undesired cross-activation and evade pathogen suppression of immunity. Our results expand the molecular mechanisms of NLR activation pointing to transition from homodimers to higher-order oligomeric resistosomes.
Subject(s)
NLR Proteins , Nicotiana , Plant Immunity , Plant Proteins , Protein Multimerization , Nicotiana/metabolism , Nicotiana/immunology , NLR Proteins/metabolism , Plant Proteins/metabolism , Plant Proteins/genetics , Plant Proteins/immunology , Cryoelectron Microscopy , Disease Resistance/immunology , Plant Diseases/immunologyABSTRACT
The kagome lattice of transition metal atoms provides an exciting platform to study electronic correlations in the presence of geometric frustration and nontrivial band topology1-18, which continues to bear surprises. Here, using spectroscopic imaging scanning tunnelling microscopy, we discover a temperature-dependent cascade of different symmetry-broken electronic states in a new kagome superconductor, CsV3Sb5. We reveal, at a temperature far above the superconducting transition temperature Tc ~ 2.5 K, a tri-directional charge order with a 2a0 period that breaks the translation symmetry of the lattice. As the system is cooled down towards Tc, we observe a prominent V-shaped spectral gap opening at the Fermi level and an additional breaking of the six-fold rotational symmetry, which persists through the superconducting transition. This rotational symmetry breaking is observed as the emergence of an additional 4a0 unidirectional charge order and strongly anisotropic scattering in differential conductance maps. The latter can be directly attributed to the orbital-selective renormalization of the vanadium kagome bands. Our experiments reveal a complex landscape of electronic states that can coexist on a kagome lattice, and highlight intriguing parallels to high-Tc superconductors and twisted bilayer graphene.
ABSTRACT
Sepsis, septic shock, and their sequelae are the leading causes of death in intensive care units, with limited therapeutic options. Disease resistance and tolerance are two evolutionarily conserved yet distinct defense strategies that protect the host against microbial infection. Here, we report that taurolidine administered at 6 h before septic challenge led to strong protection against polymicrobial sepsis by promoting both host resistance and disease tolerance characterized by accelerated bacterial clearance, ameliorated organ damage, and diminished vascular and gut permeability. Notably, taurolidine administered at 6 h after septic challenge also rescued mice from sepsis-associated lethality by enhancing disease tolerance to tissue and organ injury. Importantly, this in vivo protection afforded by taurolidine depends on an intact autophagy pathway, as taurolidine protected wild-type mice but was unable to rescue autophagy-deficient mice from microbial sepsis. In vitro, taurolidine induced light chain 3-associated phagocytosis in innate phagocytes and autophagy in vascular endothelium and gut epithelium, resulting in augmented bactericidal activity and enhanced cellular tolerance to endotoxin-induced damage in these cells. These results illustrate that taurolidine-induced autophagy augments both host resistance and disease tolerance to bacterial infection, thereby conferring protection against microbial sepsis.
Subject(s)
Sepsis , Thiadiazines , Animals , Autophagy , Mice , Phagocytosis , Sepsis/drug therapy , Sepsis/metabolism , Taurine/analogs & derivatives , Thiadiazines/pharmacologyABSTRACT
Two-dimensional (2D) materials are outstanding candidates for stretchable electronics, but a significant challenge is their heterogeneous integration into stretchable geometries on soft substrates. Here, we demonstrate a strategy for stretchable thin film transistors (2D S-TFT) based on wrinkled heterostructures on elastomer substrates where 2D materials formed the gate, source, drain, and channel and characterized them with Raman spectroscopy and transport measurements. The 2D S-TFTs had initial mobility of 4.9 ± 0.7 cm2/(V s). The wrinkling reduced the strain transferred into the 2D materials by a factor of 50, allowing a substrate stretch of up to 23% that could be cycled thousands of times without electrical degradation. The stretch did not alter the mobility but did lead to strain-induced threshold voltage shifts by ΔVT = -1.9 V. These 2D S-TFTs form the foundation for stretchable integrated circuits and enable investigations of the impact of heterogeneous strain on electron transport.
ABSTRACT
X-ray scintillators have utility in radiation detection, therapy, and imaging. Various materials, such as halide perovskites, organic illuminators, and metal clusters, have been developed to replace conventional scintillators due to their ease of fabrication, improved performance, and adaptability. However, they suffer from self-absorption, chemical instability, and weak X-ray stopping power. Addressing these limitations, we employ alkali metal doping to turn nonemissive CsPb2Br5 into scintillators. Introducing alkali metal dopants causes lattice distortion and enhances electron-phonon coupling, which creates transient potential energy wells capable of trapping photogenerated or X-ray-generated electrons and holes to form self-trapped excitons. These self-trapped excitons undergo radiative recombination, resulting in a photoluminescence quantum yield of 55.92%. The CsPb2Br5-based X-ray scintillator offers strong X-ray stopping power, high resistance to self-absorption, and enhanced stability when exposed to the atmosphere, chemical solvents, and intense irradiation. It exhibits a detection limit of 162.3 nGyair s-1 and an imaging resolution of 21 lp mm-1.
ABSTRACT
Molecular self-assembly is a widely recognized approach for fabricating biomimetic functional nanostructures. Here, we report the synthesis of two giant hollow coronoid-like supramolecular hexagons, H1 and H2. These hexagons feature large cavities, showcasing unique inner and outer hexagons fixed by specific connectivities for enhanced stability and high metal center density. H1 exhibits properties that can be transformed through the thermodynamic conversion of the metallopolymer formed by L1 and L2. With an edge length of 6.8 nm, H2 is one of the largest hexagons reported to date. 1D and 2D NMR, TEM, ESI-MS, and TWIM-MS experiments provided conclusive evidence for the composition and structure of the assembled hexagons. This work demonstrates the feasibility of constructing giant supramolecular architectures with precise control over their size and shape, opening up new possibilities for the design and synthesis of sophisticated supramolecules and nonbiological materials.
ABSTRACT
Single-atom metal-doped M-N-C (MâFe, Co, Mn, or Ni) catalysts exhibit excellent catalytic activity toward oxygen reduction reactions (ORR). However, their performance still has a large gap considering the demand for their practical applications. This study reports a high-performance dual single-atom doped carbon catalyst (HfCo-N-C), which is prepared by pyrolyzing Co and Hf co-doped ZIF-8 . Co and Hf are atomically dispersed in the carbon framework and coordinated with N to form Co-N4 and Hf-N4 active moieties. The synergetic effect between Co-N4 and Hf-N4 significantly enhance the catalytic activity and durability of the catalyst. In an acidic medium, the ORR half-wave potential (E1/2) of the catalyst is up to 0.82 V , which is much higher than that of the Co-N-C catalyst without Hf co-doping (0.80 V). The kinetic current density of the catalyst is up to 2.49 A cm-2 at 0.85 V , which is 1.74 times that of the Co-N-C catalyst without Hf co-doping. Moreover, the catalyst exhibits excellent cathodic performance in single proton exchange membrane fuel cells and Zn-air batteries. Furthermore, Hf co-doping can effectively suppress the formation of H2O2, resulting in significantly improved stability and durability.
ABSTRACT
Gene expression is regulated at multiple levels, including RNA processing and DNA methylation/demethylation. How these regulations are controlled remains unclear. Here, through analysis of a suppressor for the OsEIN2 over-expressor, we identified an RNA recognition motif protein SUPPRESSOR OF EIN2 (SOE). SOE is localized in nuclear speckles and interacts with several components of the spliceosome. We find SOE associates with hundreds of targets and directly binds to a DNA glycosylase gene DNG701 pre-mRNA for efficient splicing and stabilization, allowing for subsequent DNG701-mediated DNA demethylation of the transgene promoter for proper gene expression. The V81M substitution in the suppressor mutant protein mSOE impaired its protein stability and binding activity to DNG701 pre-mRNA, leading to transgene silencing. SOE mutation enhances grain size and yield. Haplotype analysis in c. 3000 rice accessions reveals that the haplotype 1 (Hap 1) promoter is associated with high 1000-grain weight, and most of the japonica accessions, but not indica ones, have the Hap 1 elite allele. Our study discovers a novel mechanism for the regulation of gene expression and provides an elite allele for the promotion of yield potentials in rice.
Subject(s)
Gene Expression Regulation, Plant , Gene Silencing , Oryza , Plant Proteins , Transgenes , Oryza/genetics , Plant Proteins/genetics , Plant Proteins/metabolism , Promoter Regions, Genetic/genetics , Mutation/genetics , Protein Domains , Haplotypes/genetics , DNA Methylation/genetics , Protein Binding , Plants, Genetically Modified , AllelesABSTRACT
We present the fabrication of a novel Starfruit-shaped metal-organic framework (SMOF) composed of zirconium and Tetra(4-carboxyphenyl)porphine linkers. The SMOF exhibits a unique morphology with edge-sharing two-dimensional (2D) nanosheet petals. Our investigation unravels a captivating transformation process, wherein three-dimensional (3D) shuttle-shaped MOFs form initially and subsequently evolve into 2D nanosheet-based SMOF structures. The distinct morphology of SMOF showcases superior catalytic activity in detoxifying G-type nerve agent and blister agent simulants, surpassing that of its 3D counterparts. This discovery of the 3D-to-2D transition growth pathway unlocks exciting opportunities for exploring novel strategies in advanced MOF nanostructure development, not only for catalysis but also for various other applications.
ABSTRACT
Invited for the cover of this issue is the group of Cheng-an Tao, Jianfang Wang and co-workers at the University of Defense Technology. The image depicts a novel starfruit-shaped metal-organic framework composed of zirconium and tetra(4-carboxyphenyl)porphine linkers and characterized by 2D nanosheet petals grown through edge-sharing that showcases superior catalytic activity. Read the full text of the article at 10.1002/chem.202302835.
ABSTRACT
Carbon-fiber microelectrodes (CFMEs) are primarily used to detect neurotransmitters in vivo with fast-scan cyclic voltammetry (FSCV) but other carbon nanomaterial electrodes are being developed. CFME sensitivity to dopamine is improved by applying a constant 1.5 V vs. Ag/AgCl for 3 minutes while dipped in 1 M KOH, which etches the surface and adds oxygen functional groups. However, KOH etching of other carbon nanomaterials and applications to other neurochemicals have not been investigated. Here, we explored KOH etching of CFMEs and carbon nanotube yarn microelectrodes (CNTYMEs) to characterize sensitivity to dopamine, epinephrine, norepinephrine, serotonin, and 3,4-dihydroxyphenylacetic acid (DOPAC). With CNTYMEs, the potential was applied in KOH for 1 minute because the electrode surface cracked with the longer time. KOH treatment increased electrode sensitivity to each cationic neurotransmitter roughly 2-fold for CFMEs, and 2- to 4-fold for CNTYMEs. KOH treatment decreased the background current of the CFMEs by etching the surface carbon; however, KOH-treatment increased the CNTYME background current because the potential separates individual nanotubes. For DOPAC, the current increase was smaller at CNTYMEs because it is anionic and was repelled by the negative holding potential and did not access the crevices. XPS and Raman spectroscopy showed that KOH treatment changed the CNTYME surface chemistry by increasing defect sites and adding oxide functional groups. KOH-treated CNTYMEs had less fouling to serotonin than normal CNTYMEs. Therefore, KOH treatment activates both CFMEs and CNTYMEs and could be used in biological measurements to increase the sensitivity and decrease fouling for neurochemical measurements.
Subject(s)
Nanostructures , Nanotubes, Carbon , Dopamine , Serotonin , 3,4-Dihydroxyphenylacetic Acid , Microelectrodes , Nanotubes, Carbon/chemistry , Neurotransmitter Agents , Carbon FiberABSTRACT
The template-directed strategy has been extensively employed for the construction of supramolecular architectures. However, with the increase in the size and complexity of these structures, the synthesis difficulty of the templates escalates exponentially, thereby impeding the widespread application of this strategy. In this study, two truncated triangles T1 and T2 were successfully self-assembled through a novel segmented template strategy by segmenting the core triangular template into portions. Two metallo-organic ligands L2 and L3 were designed and synthesized by dividing the central stable triangle into three separate parts and incorporating them into the precursor ligands, which served as templates to guide the self-assembly process with ligands L1 and L4, respectively. The assembled structures were unambiguously characterized by multidimensional and multinuclear NMR (1H, COSY, NOESY), multidimensional mass spectrometry analysis (ESI-MS and TWIM-MS), and transmission electron microscopy (TEM). Moreover, we observed the formation of fiberlike nanotubes from single-molecule triangles by hierarchical self-assembly.
ABSTRACT
Birefringent crystals, which can modulate and polarize light, play a vital role in the development of optical sensors and optoelectronic devices. Herein, we synthesized a new birefringent crystal [(C10N2H10)(HI2O6)(HIO3)(IO3)] with large birefringence by integrating the large π-conjugated 4,4'-bipyridine group with two types of iodates anions ([IO3]- and [HI2O6]-) characterized by high polarizability anisotropy and strong stereochemically active lone pairs (SCALP). The crystal exhibits a large measured birefringence of 0.171 at 550 nm, surpassing most organic-inorganic hybrid iodate birefringent materials reported in the literature. Theoretical analyses reveal that the optical properties of the crystal arise primarily from the synergistic interactions between the π-conjugated 4,4'-bipyridine group and I-O groups. This research presents an effective method for the strategic integration of large π-conjugated organic cations into iodates, facilitating the design of novel birefringent materials and encouraging further exploration of superior birefringent substances.
ABSTRACT
While partial nitrification (PN) has the potential to reduce energy for aeration, it has proven to be unstable when treating low-strength wastewater. This study introduces an innovative combined strategy incorporating a low rate of oxygen supply, pH control, and sulfide addition to selectively inhibit nitrite-oxidizing bacteria (NOB). This strategy led to a stable PN in a laboratory-scale membrane aerated biofilm reactor (MABR). Over a period of 260 days, the nitrite accumulation ratio exceeded 60% when treating synthetic sewage containing 50 mg NH4+-N/L. Through in situ activity testing and high-throughput sequencing, the combined strategy led to low levels of nitrite-oxidation activity (<5.5 mg N/m2 h), Nitrospira species (relative abundance <1%), and transcription of nitrite-oxidation genes (undetectable). The addition of sulfide led to simultaneous PN and autotrophic denitrification in the single-stage MABR, resulting in over 60% total inorganic nitrogen removal. Sulfur-based autotrophic denitrification consumed nitrite and inhibited NOB conversion of nitrite to nitrate. The combined strategy has potential to be applied in large-scale sewage treatment and deserves further exploration.
Subject(s)
Bioreactors , Denitrification , Nitrification , Sulfides , Sulfides/chemistry , Autotrophic Processes , Nitrites/metabolism , Sewage , Biofilms , Wastewater/chemistryABSTRACT
BACKGROUND: The effect of the periurethral cleansing range on catheter-associated urinary tract infection (CAUTI) occurrence remains unknown. The purpose of this study was to evaluate the efficacy of expanded periurethral cleansing for reducing CAUTI in comatose patients. METHODS: In this randomized controlled trial, eligible patients in our hospital were enrolled and allocated randomly to the experimental group (expanded periurethral cleansing protocol; n = 225) or the control group (usual periurethral cleansing protocol; n = 221). The incidence of CAUTI on days 3, 7, and 10 after catheter insertion were compared, and the pathogen results and influencing factors were analyzed. RESULTS: The incidences of CAUTI in the experimental and control groups on days 3, 7, and 10 were (5/225, 2.22% vs. 7/221, 3.17%, P = 0.54), (12/225, 5.33% vs. 18/221, 8.14%, P = 0.24), and (23/225, 10.22% vs. 47/221, 21.27%, P = 0.001), respectively; Escherichia coli and Candida albicans were the most common species in the two groups. The incidences of bacterial CAUTI and fungal CAUTI in the two groups were 11/225, 4.89% vs. 24/221, 10.86%, P = 0.02) and (10/225, 4.44% vs. 14/221, 6.33%, P = 0.38), respectively. The incidences of polymicrobial CAUTI in the two groups were 2/225 (0.89%) and 9/221 (4.07%), respectively (P = 0.03). The percentages of CAUTI-positive females in the two groups were 9.85% (13/132) and 29.52% (31/105), respectively (P < 0.05). The proportion of CAUTI-positive patients with diabetes in the experimental and control groups was 17.72% (14/79), which was lower than the 40.85% (29/71) in the control group (P < 0.05). CONCLUSION: Expanded periurethral cleansing could reduce the incidence of CAUTI, especially those caused by bacteria and multiple pathogens, in comatose patients with short-term catheterization (≤ 10 days). Female patients and patients with diabetes benefit more from the expanded periurethral cleansing protocol for reducing CAUTI.
Subject(s)
Catheter-Related Infections , Coma , Urinary Tract Infections , Humans , Female , Urinary Tract Infections/prevention & control , Urinary Tract Infections/epidemiology , Male , Middle Aged , Catheter-Related Infections/prevention & control , Catheter-Related Infections/epidemiology , Adult , Aged , Urinary Catheterization/adverse effects , Urinary Catheterization/methods , UrethraABSTRACT
BACKGROUND: Metabolic syndrome (MetS) is a clinical syndrome characterized by multiple metabolic disorders and is a serious global health problem. The coffee effect, acting as one of the most prevalent beverages on metabolic syndrome, is debatable. METHODS: We included patients from the National Health and Nutrition Examination Survey 2003-2018 and used a comprehensive evaluation called the MetS z-score to assess the severity of metabolic syndrome. The relationship between coffee, decaffeinated coffee, tea, and MetS z-scores was explored using a weighted linear regression. We also divided the participants into metabolic and non-metabolic syndrome groups according to the NCEP/ATP III criteria for the subgroup analysis. RESULTS: A total of 14,504 participants were included in this study. The results demonstrated that drinking more than three cups of coffee daily was significantly linked to lower MetS z-scores (p < 0.001). Daily coffee consumption was also associated with lower BMI (p = 0.02), systolic blood pressure (p < 0.001), Homeostatic Model Assessment for Insulin Resistance (p < 0.001), and triglycerides (p < 0.001), while it was positively correlated with HDL-C (p = 0.001). Participants who consumed more than three cups of coffee daily had a lower MetS z-score in the MetS (p < 0.001) and non-MetS (p = 0.04) groups. CONCLUSION: This research indicates that coffee consumption is linked to MetS severity. However, decaffeinated coffee and tea intake were unrelated to MetS severity.
Subject(s)
Coffee , Metabolic Syndrome , Nutrition Surveys , Severity of Illness Index , Humans , Metabolic Syndrome/epidemiology , Nutrition Surveys/methods , Nutrition Surveys/statistics & numerical data , Female , Male , Middle Aged , Adult , Risk Factors , Cross-Sectional Studies , United States/epidemiology , TeaABSTRACT
AIMS: Ethyl hexanoate, one of the key flavor compounds in strong-flavor Baijiu. To improve the content of ethyl hexanoate in strong-flavor Baijiu, a functional strain with high yield of ethyl hexanoate was screened and its ester-producing performance was studied. METHODS AND RESULTS: Upon identification, the strain was classified as Candida sp. and designated as ZY002. Under optimal fermentation conditions, the content of ethyl hexanoate synthesized by ZY002 can be as high as 170.56 mg L-1. A fermentation test was carried out using the ZY002 strain bioaugmented Daqu to verify the role of the strain applied to Baijiu brewing. It was found that strain ZY002 could not only improve the moisture and alcohol contents of fermented grains but also diminish the presence of reducing sugar and crude starch. Furthermore, it notably amplified the abundance of flavor compounds. CONCLUSION: In this study, Candida sp. ZY002 with a high yield of ethyl hexanoate provided high-quality strain resources for the actual industrial production of Baijiu.
Subject(s)
Candida , Caproates , Esters , Fermentation , Fermented Foods , Caproates/metabolism , Esters/metabolism , Esters/analysis , Fermented Foods/microbiology , Fermented Foods/analysis , Candida/metabolism , Flavoring Agents/metabolism , Food Microbiology , Alcoholic Beverages/microbiology , Alcoholic Beverages/analysisABSTRACT
Climate change is a common challenge faced by all humanity. Promoting emission and carbon reduction in agricultural land is the most important priority for addressing climate change and realizing sustainable development. Based on data from 296 prefecture-level cities in China from 2011 to 2021, this study utilizes machine-learning and text-analysis methods to construct an indicator of government climate-risk attention (GCRA). It combines a two-way fixed-effects model to investigate how GCRA affects agricultural-land carbon emissions (ALCE) and carbon intensity (ALCI) and the mechanism of the impact. The results indicate that (1) GCRA substantially reduces ALCE and ALCI, and the conclusions are robust to a battery of tests. Furthermore, (2) mechanism analysis reveals that GCRA primarily uses three mechanisms-strengthening environmental regulation, promoting agricultural green-technology innovation, and upgrading agricultural-land mechanization-to reduce ALCE and lower ALCI. Additionally, (3) heterogeneity analysis suggests that the carbon-emission reduction effect of GCRA is more significant in the east, in arid and humid climate zones, and in non-grain-producing regions. Finally, (4) spatial-spillover effect analysis and quantile regression results demonstrate that GCRA also significantly inhibits carbon emissions and the carbon intensity of nearby agricultural land, with the inhibition effect becoming more pronounced at higher levels of government attention. This study's discoveries are helpful in promoting the emission reduction and carbon sequestration of agricultural land and provide references for developing countries to cope with climate change.