Fabricating ultrathin two-dimensional (2D) covalent organic framework (COF) nanosheets (NSs) in large scale and high yield still remains a great challenge. This limits the exploration of the unique functionalities and wide range of application potentials of such materials. Herein, we develop a scalable general bottom-up approach to facilely synthesize ultrathin (<2.1 nm) imine-based 2D COF NSs (including COF-366 NSs, COF-367 NSs, COF-367-Co NSs, TAPB-PDA COF NSs, and TAPB-BPDA COF NSs) in large scale (>100 mg) and high yield (>55%), via an imine-exchange synthesis strategy through adding large excess amounts of 2,4,6-trimethylbenzaldehyde into the reaction system under solvothermal conditions. Impressively, visualization of the periodic pore lattice for COF-367 NSs by a scanning tunneling microscope (STM) clearly discloses the ultrathin 2D COF nature. In particular, the ultrathin COF-367-Co NSs isolated are subject to the heterogeneous photocatalyst for CO2-to-CO conversion, showing excellent efficiency with a CO production rate as high as 10 162 μmol g–1 h–1 and a selectivity of ca. 78% in aqueous media under visible-light irradiation, far superior to corresponding bulk materials and comparable with the thus far reported state-of-the-art visible-light driven heterocatalysts.

We present a study of electric, thermal and thermoelectric response in noncollinear antiferromagnet Mn3Sn, which hosts a large Anomalous Hall Effect (AHE). Berry curvature generates off-diagonal thermal(Righi-Leduc) and thermoelectric(Nernst) signals, which are detectable at room temperature and invertible with a small magnetic field. The thermal and electrical Hall conductivities respect the Wiedemann-Franz law, implying that the transverse currents induced by Berry curvature are carried by Fermi surface quasi-particles. In contrast to conventional ferromagnets, the anomalous Lorenz number remains close to the Sommerfeld number over the whole temperature range of study, excluding any contribution by inelastic scattering and pointing to Berry curvature as the unique source of AHE. The anomalous off-diagonal thermo-electric and Hall conductivities are strongly temperature-dependent and their ratio is close to kB/e.The ordinary Hall effect, the transverse electric field generated by a longitudinal charge current in presence of a magnetic field, is caused by the Lorentz force exerted by magnetic field on charge carriers. In ferromagnetic solids, there is an additional component to this response (known as extraordinary or anomalous), thought to arise as a result of a sizeable magnetization. During the past decade, a clear link between the Anomalous Hall Effect (AHE) and the Berry curvature of Bloch waves has been established [1,2]. Charged carriers of entropy are also affected by the Lorenz force. Therefore, one expects a transverse component to thermal conductivity called the Righi-Leduc (or the thermal Hall) effect [3] in presence of magnetic field. This is also the case of thermoelectric conductance, which acquires an off-diagonal component, α ij , intimately linked to the Nernst coefficient, directly measurable by experiment [4]. When the Berry curvature replaces the magnetic field, counterparts of the AHE appear in the thermal and thermoelectric response of ferromagnets [5][6][7][8]. They can be an additional source of information regarding the fundamental mechanism leading to the generation of dissipationless transverse currents. Recently, following a proposition by Chen, Niu and Macdonald[9], Nakasutji et al. and Nayak et al. found a large AHE in Mn 3 Sn [10] and Mn 3 Ge [11,12], which are noncollinear antiferromagnets at room temperature. Several recent theoretical studies were devoted to this issue [13][14][15].In this letter, we present a study of Anomalous Righi-Leduc and Nernst effects (ANE) in Mn 3 Sn in order to quantify the amplitude of these coefficients compared to their Hall counterpart.We detect a large Anomalous Righi-Leduc conductivity and find that its magnitude corresponds to what is expected according to the Wiedemann-Franz (WF) Law over an extended temperature window. The result confirms a theoretical prediction by Haldane[16] with important consequences for the debate regarding the two alternative formulations of anomalous Hall effect [16][17][18]. AHE can be formulated as a property of th...

Experimental autoimmune encephalomyelitis (EAE) is a T-celldependent autoimmune disease that reproduces the inflammatory demyelinating pathology of multiple sclerosis (MS). We investigated the efficacy and mechanism of immunosuppression against EAE by administering 2-amino-[2-(4-octylphenyl) ethyl]-1,3-propanediol hydrochloride (FTY720) in Lewis rats immunized with myelin basic protein together with complete Freund's adjuvant. FTY720 treatment almost completely protected the rats against disease. The protection by FTY720 was associated with a dramatic reduction in the number of lymphocytes staining for T-cell receptors in the spinal cord as examined by immunohistochemistry. The mRNA expression of Th1 cytokines interleukin (IL)-2, IL-6, and interferon-␥ in the spinal cord was also reduced dramatically as assessed by reversetranscription polymerase chain reaction. Furthermore, lymphocytes isolated from the spleen of FTY720-treated rats were transferred into naive recipient rats against EAE manifestation by reducing both disease incidence and clinical score. These results suggested that the protective anti-inflammatory effect of treatment with FTY720 was, to a large extent, due to the inhibition of encephalitogenic T-cell responses and/or their migration into the central nervous system and may be a potential candidate for use in treating patients with MS.

Atopic dermatitis (AD) is a chronic pruritic skin disorder affecting many people especially young children. It is a disease caused by the combination of genetic predisposition, immune dysregulation, and skin barrier defect. In recent years, emerging evidence suggests oxidative stress may play an important role in many skin diseases and skin aging, possibly including AD. In this review, we give an update on scientific progress linking oxidative stress to AD and discuss future treatment strategies for better disease control and improved quality of life for AD patients.

CD4 T cells have been implicated in cancer immunity for their helper functions. Moreover, their direct cytotoxic potential has been shown in some patients with cancer. Here, by mining single-cell RNA-seq datasets, we identified CD4 T cell clusters displaying cytotoxic phenotypes in different human cancers, resembling CD8 T cell profiles. Using the peptide-MHCII-multimer technology, we confirmed ex vivo the presence of cytolytic tumor-specific CD4 T cells. We performed an integrated phenotypic and functional characterization of these cells, down to the single-cell level, through a high-throughput nanobiochip consisting of massive arrays of picowells and machine learning. We demonstrated a direct, contact-, and granzyme-dependent cytotoxic activity against tumors, with delayed kinetics compared to classical cytotoxic lymphocytes. Last, we found that this cytotoxic activity was in part dependent on SLAMF7. Agonistic engagement of SLAMF7 enhanced cytotoxicity of tumor-specific CD4 T cells, suggesting that targeting these cells might prove synergistic with other cancer immunotherapies.

Titanium alloys with various porous structures can be fabricated by advanced additive manufacturing techniques, which are attractive for use as scaffolds for bone defect repair. However, modification of the scaffold surfaces, particularly inner surfaces, is critical to improve the osteointegration of these scaffolds. In this study, a biomimetic approach was employed to construct polydopamine-assisted hydroxyapatite coating (HA/pDA) onto porous Ti6Al4V scaffolds fabricated by the electron beam melting method. The surface modification was characterized with the field emission scanning electron microscopy, energy dispersive spectroscopy, water contact angle measurement, and confocal laser scanning microscopy. Attachment and proliferation of MC3T3-E1 cells on the scaffold surface were significantly enhanced by the HA/pDA coating compared to the unmodified surfaces. Additionally, MC3T3-E1 cells grown on the HA/pDA-coated Ti6Al4V scaffolds displayed significantly higher expression of runt-related transcription factor-2, alkaline phosphatase, osteocalcin, osteopontin, and collagen type-1 compared with bare Ti6Al4V scaffolds after culture for 14 days. Moreover, microcomputed tomography analysis and Van-Gieson staining of histological sections showed that HA/pDA coating on surfaces of porous Ti6Al4V scaffolds enhanced osteointegration and significantly promoted bone regeneration after implantation in rabbit femoral condylar defects for 4 and 12 weeks. Therefore, this study provides an alternative to biofunctionalized porous Ti6Al4V scaffolds with improved osteointegration and osteogenesis functions for orthopedic applications.

Intrinsic anomalous Nernst effect (ANE), like its Hall counterpart, is generated by Berry curvature of electrons in solids. Little is known about its response to disorder. In contrast, the link between the amplitude of the ordinary Nernst coefficient (ONE) and the mean-free-path is extensively documented. Here, by studying Co3Sn2S2, a topological half-metallic semimetal hosting sizable and recognizable ordinary and anomalous Nernst responses, we demonstrate an anti-correlation between the amplitude of ANE and carrier mobility. We argue that the observation, paradoxically, establishes the intrinsic origin of the ANE in this system. We conclude that various intrinsic off-diagonal coefficients are set by the way the Berry curvature is averaged on a grid involving the mean-free-path, the Fermi wavelength and the de Broglie thermal length.

Cell secretion dynamics plays a central role in physiological and disease processes. Due to its various temporal profiles, it is essential to implement a precise detection scheme for continuous monitoring of secretion in real time. The current fluorescent and colorimetric approaches hinder such applications due to their multiple time-consuming steps, molecular labeling, and especially the 'snapshot' endpoint readouts. Here, we develop a nanoplasmonic biosensor for real-time monitoring of live cell cytokine secretion in a label-free configuration. Our nanoplasmonic biosensor is composed of gold nanohole arrays supporting extraordinary optical transmission (EOT), which enables sensitive and high-throughput analysis of biomolecules. The nanobiosensor is integrated with an adjustable microfluidic cell module for the analysis of live cells under well-controlled culture conditions. We achieved an outstanding sensitivity for the detection of vascular endothelial growth factor (VEGF) directly in complex cell media. Significantly, the secretion dynamics from live cancer cells were monitored and quantified for 10 hours while preserving good cell viability. This novel approach of probing cytokine secretion activity is compatible with conventional inverted microscopes found in a common biology laboratory. With its simple optical set-up and label-free detection configuration, we anticipate our nanoplasmonic biosensor to be a powerful tool as a lab-on-chip device to analyze cellular activities for fundamental cell research and biotechnologies.