As a rapidly growing family of 2D transition metal carbides and nitrides, MXenes are recognized as promising materials for the development of future electronics and optoelectronics. So far, the ...reported patterning methods for MXene films lack efficiency, resolution, and compatibility, resulting in limited device integration and performance. Here, a high‐performance MXene image sensor array fabricated by a wafer‐scale combination patterning method of an MXene film is reported. This method combines MXene centrifugation, spin‐coating, photolithography, and dry‐etching and is highly compatible with mainstream semiconductor processing, with a resolution up to 2 µm, which is at least 100 times higher than other large‐area patterning methods reported previously. As a result, a high‐density integrated array of 1024‐pixel Ti3C2Tx/Si photodetectors with a detectivity of 7.73 × 1014 Jones and a light–dark current ratio (Ilight/Idark) of 6.22 × 106, which is the ultrahigh value among all reported MXene‐based photodetectors, is fabricated. This patterning technique paves a way for large‐scale high‐performance MXetronics compatible with mainstream semiconductor processes.
MXenes are promising for future electronics and optoelectronics; however, previously reported patterning methods lack efficiency, resolution, and compatibility with mainstream semiconductor processing. Here, a wafer‐scale combination patterning method with a resolution up to the micrometer scale is developed, resulting in an integrated array of 1024‐pixel Ti3C2Tx/Si photodetectors with a record‐high detectivity of 7.73 × 1014 Jones.
With advances in connectomics, transcriptome and neurophysiological technologies, the neuroscience of brain-wide neural circuits is poised to take off. A major challenge is to understand how a vast ...diversity of functions is subserved by parcellated areas of mammalian neocortex composed of repetitions of a canonical local circuit. Areas of the cerebral cortex differ from each other not only in their input-output patterns but also in their biological properties. Recent experimental and theoretical work has revealed that such variations are not random heterogeneities; rather, synaptic excitation and inhibition display systematic macroscopic gradients across the entire cortex, and they are abnormal in mental illness. Quantitative differences along these gradients can lead to qualitatively novel behaviours in non-linear neural dynamical systems, by virtue of a phenomenon mathematically described as bifurcation. The combination of macroscopic gradients and bifurcations, in tandem with biological evolution, development and plasticity, provides a generative mechanism for functional diversity among cortical areas, as a general principle of large-scale cortical organization.
The quantum anomalous Hall (QAH) effect, which has been realized in magnetic topological insulators (TIs), is the key to applications of dissipationless quantum Hall edge states in electronic ...devices. However, investigations and utilizations of the QAH effect are limited by the ultralow temperatures needed to reach full quantization—usually below 100 mK in either Cr‐ or V‐doped (Bi,Sb)2Te3 of the two experimentally confirmed QAH materials. Here it is shown that by codoping Cr and V magnetic elements in (Bi,Sb)2Te3 TI, the temperature of the QAH effect can be significantly increased such that full quantization is achieved at 300 mK, and zero‐field Hall resistance of 0.97 h/e2 is observed at 1.5 K. A systematic transport study of the codoped (Bi,Sb)2Te3 films with varied Cr/V ratios reveals that magnetic codoping improves the homogeneity of ferromagnetism and modulates the surface band structure. This work demonstrates magnetic codoping to be an effective strategy for achieving high‐temperature QAH effect in TIs.
In Cr and V codoped (Bi,Sb)2Te3 topological insulator films, the quantum anomalous Hall (QAH) effect is achieved at 300 mK, about one order of magnitude higher than that for singly Cr‐ or V‐doped ones, and the energy scale of QAH state reaches 1.4 K. The transport study of the codoped films with varied Cr/V ratios reveals the origins of enhancement.
Alginate oligosaccharides (AOS), products of alginate degradation by endotype alginate lyases, possess favorable biological activities and have broad applications. Although many have been reported, ...alginate lyases with homogeneous AOS products and secretory production by an engineered host are scarce. Herein, the alginate lyase AlyC7 from
sp. C42 was characterized as a trisaccharide-producing lyase exhibiting high activity and broad substrate specificity. With PelB as the signal peptide and 500 mM glycine as the additive, the extracellular production of AlyC7 in
reached 1122.8 U/mL after 27 h cultivation in Luria-Bertani medium. The yield of trisaccharides from sodium alginate degradation by the produced AlyC7 reached 758.6 mg/g, with a purity of 85.1%. The prepared AOS at 20 μg/mL increased the root length of lettuce, tomato, wheat, and maize by 27.5%, 25.7%, 9.7%, and 11.1%, respectively. This study establishes a robust foundation for the industrial and agricultural applications of AlyC7.
This article studies the maximum likelihood inference on a class of Wiener processes with random effects for degradation data. Degradation data are special case of functional data with monotone ...trend. The setting for degradation data is one on which n independent subjects, each with a Wiener process with random drift and diffusion parameters, are observed at possible different times. Unit-to-unit variability is incorporated into the model by these random effects. EM algorithm is used to obtain the maximum likelihood estimators of the unknown parameters. Asymptotic properties such as consistency and convergence rate are established. Bootstrap method is used for assessing the uncertainties of the estimators. Simulations are used to validate the method. The model is fitted to bridge beam data and corresponding goodness-of-fit tests are carried out. Failure time distributions in terms of degradation level passages are calculated and illustrated.
Retinal vessels play an important role in the diagnostic procedure of retinopathy. Accurate segmentation of retinal vessels is crucial for pathological analysis. In this paper, we propose a new ...retinal vessel segmentation method based on level set and region growing. Firstly, a retinal vessel image is preprocessed by the contrast-limited adaptive histogram equalization and a 2D Gabor wavelet to enhance the vessels. Then, an anisotropic diffusion filter is used to smooth the image and preserve vessel boundaries. Finally, the region growing method and a region-based active contour model with level set implementation are applied to extract retinal vessels, and their results are combined to achieve the final segmentation. Comparisons are conducted on the publicly available DRIVE and STARE databases using three different measurements. Experimental results show that the proposed method reaches an average accuracy of 94.77% on the DRIVE database and 95.09% on the STARE database.
•A new segmentation method for retinal vessels based on level set and region growing.•Comparisons are conducted on DRIVE and STARE databases using three different measures.•The proposed method reaches accuracy of 94.77% on the DRIVE database.•The proposed method reaches accuracy of 95.09% on the STARE database.
Replacement of CC unit with its isoelectronic BN unit in aromatics provides a new class of molecules with appealing properties, which have attracted great attention recently. In this Concept, we ...focus on BN‐substituted polycyclic aromatics with fused structures, and review their synthesis, photophysical, and redox properties, as well as their applications in organic electronics. We also present challenging synthetic targets, large BN‐ substituted polycyclic aromatics, such as regioregular BN heterosuperbenzenes, which can be viewed as BN‐doped nanographenes. Finally, we propose an atomically precise bottom‐up synthesis of structurally well‐defined BN‐doped graphenes.
A new super hero! BN substitution in aromatic systems could provide a new family of interesting compounds. In this Concept, the development of BN‐substituted polycyclic aromatics is reported, and their synthesis, properties and electronic applications are summarized. From monocyclic BN‐substituted benzene to polycyclic BN heteroaromatics (like BN heterosuperbenzene), the possible ways to structurally well‐defined BN‐doped graphenes are proposed.
China was the last country in the world to relax COVID-19 restrictions. A successful public health policy requires public support. This analysis examined the factors associated with Chinese support ...for zero-COVID and relaxing COVID-19 restrictions in China.
Two online surveys were conducted among Chinese participants in mainland China on June 10-13 (N = 460) and December 2, 2022 (N = 450). These two samples were similar based on the participants' demographics.
The results revealed that the perceived health consequences of a COVID-19 policy, perceived norms of approving a COVID-19 policy, and hope positively predicted the participants' support for the COVID-19 policy. The results further showed that collectivism and fatalism positively predicted support for zero-COVID and negatively predicted support for relaxing restrictions. COVID fatigue was negatively associated with support for zero-COVID and positively associated with support for relaxing restrictions. Liberty positively predicted support for relaxing restrictions in June and negatively predicted zero-COVID in December 2023. It did not positively or negatively predict support for the policy adopted by the government.
Collectivism, liberty, COVID fatigue, and fatalistic beliefs are important considerations connected to public support for a COVID-19 policy. The role of liberty was more nuanced and depended on the survey's time and whether the government adopted the policy.
Human infections with zoonotic coronaviruses (CoVs), including severe acute respiratory syndrome (SARS)-CoV and Middle East respiratory syndrome (MERS)-CoV, have raised great public health concern ...globally. Here, we report a novel bat-origin CoV causing severe and fatal pneumonia in humans.
We collected clinical data and bronchoalveolar lavage (BAL) specimens from five patients with severe pneumonia from Wuhan Jinyintan Hospital, Hubei province, China. Nucleic acids of the BAL were extracted and subjected to next-generation sequencing. Virus isolation was carried out, and maximum-likelihood phylogenetic trees were constructed.
Five patients hospitalized from December 18 to December 29, 2019 presented with fever, cough, and dyspnea accompanied by complications of acute respiratory distress syndrome. Chest radiography revealed diffuse opacities and consolidation. One of these patients died. Sequence results revealed the presence of a previously unknown β-CoV strain in all five patients, with 99.8% to 99.9% nucleotide identities among the isolates. These isolates showed 79.0% nucleotide identity with the sequence of SARS-CoV (GenBank NC_004718) and 51.8% identity with the sequence of MERS-CoV (GenBank NC_019843). The virus is phylogenetically closest to a bat SARS-like CoV (SL-ZC45, GenBank MG772933) with 87.6% to 87.7% nucleotide identity, but is in a separate clade. Moreover, these viruses have a single intact open reading frame gene 8, as a further indicator of bat-origin CoVs. However, the amino acid sequence of the tentative receptor-binding domain resembles that of SARS-CoV, indicating that these viruses might use the same receptor.
A novel bat-borne CoV was identified that is associated with severe and fatal respiratory disease in humans.
Synchronous rhythms represent a core mechanism for sculpting temporal coordination of neural activity in the brain-wide network. This review focuses on oscillations in the cerebral cortex that occur ...during cognition, in alert behaving conditions. Over the last two decades, experimental and modeling work has made great strides in elucidating the detailed cellular and circuit basis of these rhythms, particularly gamma and theta rhythms. The underlying physiological mechanisms are diverse (ranging from resonance and pacemaker properties of single cells to multiple scenarios for population synchronization and wave propagation), but also exhibit unifying principles. A major conceptual advance was the realization that synaptic inhibition plays a fundamental role in rhythmogenesis, either in an interneuronal network or in a reciprocal excitatory-inhibitory loop. Computational functions of synchronous oscillations in cognition are still a matter of debate among systems neuroscientists, in part because the notion of regular oscillation seems to contradict the common observation that spiking discharges of individual neurons in the cortex are highly stochastic and far from being clocklike. However, recent findings have led to a framework that goes beyond the conventional theory of coupled oscillators and reconciles the apparent dichotomy between irregular single neuron activity and field potential oscillations. From this perspective, a plethora of studies will be reviewed on the involvement of long-distance neuronal coherence in cognitive functions such as multisensory integration, working memory, and selective attention. Finally, implications of abnormal neural synchronization are discussed as they relate to mental disorders like schizophrenia and autism.
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