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Surface enhanced Raman scattering (SERS) is a vibrational spectroscopy method that enables the quantification of the concentration of small molecules. SERS sensing has been demonstrated in a wide variety of applications, from explosive and drug detection, to monitoring of bacteria growth. Underpinning SERS sensing are the sensor surfaces that are composed of vast quantities of metal nanostructures which confine light into small gaps called "hotspots", enhancing Raman scattering. While these surfaces are essential for increasing Raman scattering intensity so that analyte signal may be observed in small concentrations, they introduce signal variations due to spatial distributions of Raman enhancement and hotspot volume. In this work, we introduce a convolutional neural network model that improves concentration regressions in SERS sensors by learning the distributions of sensor surface dependent latent variables. We demonstrate that this model significantly improves predictions compared to a traditional multilayer perceptron approach, and that the model uses analyte spectral information and is capable of reasonable interpolations.

Two-dimensional materials and their combined heterostructures have paved the way for numerous next-generation electronic and optoelectronic applications. Herein, we performed first principles calculations to computationally design the MoSe2/WS2 heterostructure and consider its geometric structure, electronic properties and contact behavior, as well as the effects of the electric fields and strain. Our results show that the MoSe2/WS2 heterostructure is energetically, thermodynamically and mechanically stable. Depending on the stacking configurations, the MoSe2/WS2 heterostructure could form type-I or type-II band alignment. The versatility in contact behavior makes the MoSe2/WS2 heterostructure attractive in electronics and optoelectronics. The combination of the MoSe2/WS2 heterostructure also leads to an enhancement in the adsorption efficiency and the carrier mobility compared with the constituent components. More interestingly, our findings demonstrate that the electric field can induce the transition between type-I and type-II band alignments, as evident by the experimental measurement [J. Kistner-Morris, A. Shi, E. Liu, T. Arp, F. Farahmand, T. Taniguchi, K. Watanabe, V. Aji, C. H. Lui and N. Gabor, Nat. Commun., 2024, 15, 4075]. Additionally, we also find that strain can also induce the transition between type-I and type-II band alignments and lead to the transition from semiconductor to metal in the MoSe2/WS2 heterostructure. Our findings prove that the MoSe2/WS2 heterostructure holds significant potential for developing next-generation electronics. [ABSTRACT FROM AUTHOR]

Objective: Sjögren disease (SjD) is an autoimmune condition characterized by the dysfunction of the salivary and lacrimal glands. The study aimed to decipher the pathogenic cell populations and their immunologic pathways in the salivary glands. We further determined the therapeutic effect of inhibiting dedicator of cytokinesis 2 (DOCK2) shared by novel clusters of CD8+ T cells in an SjD mouse model. Methods: This study employed single‐cell RNA sequencing to examine the composition and dynamics of immune cells in the salivary glands of SjD mice. By analyzing the transcriptomic data and employing clustering analysis, a specific target was identified, leading to the treatment of mice with a targeted inhibitor. Results: The results showed diverse immune cell types, including B cells, CD4+ T cells, CD8+ T cells, macrophages, and natural killer cells. We identified specific clusters possessing phenotypic characteristics of immune cell subpopulations, thereby showing specific genes/pathways associated with the disease. The most striking finding was the elevated expression of DOCK2 in CD8+ T cells in the SjD model. This discovery is significant because subsequent treatment with a DOCK2 inhibitor 4‐[3‐(2‐Chlorophenyl)‐2‐propen‐1‐ylidene]‐1‐phenyl‐3,5‐pyrazolidinedione (CPYPP) led to a marked amelioration of SjD signs. Conclusion: The effectiveness of DOCK2 inhibition in alleviating SjD signs highlights the potential of DOCK2 as a therapeutic target, opening new avenues for treatment strategies that could modulate the immune response more effectively in SjD. [ABSTRACT FROM AUTHOR]

Nanoparticles from colloidal solution-with controlled composition, size, and shape-serve as excellent building blocks for plasmonic devices and metasurfaces. However, understanding hierarchical driving forces affecting the geometry of oligomers and interparticle gap spacings is still needed to fabricate high-density architectures over large areas. Here, electrohydrodynamic (EHD) flow is used as a long-range driving force to enable carbodiimide cross-linking between nanospheres and produces oligomers exhibiting sub-nanometer gap spacing over mm2 areas. Anhydride linkers between nanospheres are observed via surface-enhanced Raman scattering (SERS) spectroscopy. The anhydride linkers are cleavable via nucleophilic substitution and enable placement of nucleophilic molecules in electromagnetic hotspots. Atomistic simulations elucidate that the transient attractive force provided by EHD flow is needed to provide a sufficient residence time for anhydride cross-linking to overcome slow reaction kinetics. This synergistic analysis shows assembly involves an interplay between long-range driving forces increasing nanoparticle-nanoparticle interactions and probability that ligands are in proximity to overcome activation energy barriers associated with short-range chemical reactions. Absorption spectroscopy and electromagnetic full-wave simulations show that variations in nanogap spacing have a greater influence on optical response than variations in close-packed oligomer geometry. The EHD flow-anhydride cross-linking assembly method enables close-packed oligomers with uniform gap spacings that produce uniform SERS enhancement factors. These results demonstrate the efficacy of colloidal driving forces to selectively enable chemical reactions leading to future assembly platforms for large-area nanodevices.

Recently, the assembly of van der Waals heterostructures (vdWH) has proved to be an effective strategy to alter the properties and enhance the functionality of multifunctional devices based on 2D materials. Herein, first‐principles calculations are employed to construct the HfS2${\rm HfS}_2$/MoS2${\rm MoS}_2$ vdWH, exploring its electronic properties, contact characteristics, and the impact of electric gating. The HfS2${\rm HfS}_2$/MoS2${\rm MoS}_2$ vdWH is predicted to be structurally, thermally, and mechanically stable. The HfS2${\rm HfS}_2$/MoS2${\rm MoS}_2$ vdWH leads to a reduction in the bandgap compared to the constituent components, potentially enhancing optical absorption. Furthermore, the HfS2${\rm HfS}_2$/MoS2${\rm MoS}_2$ heterostructure forms the type‐II band alignment, localizing electrons and holes predominantly in the HfS2${\rm HfS}_2$ and MoS2${\rm MoS}_2$ layers, respectively. Such type‐II HfS2${\rm HfS}_2$/MoS2${\rm MoS}_2$ heterostructure makes it promising candidate for the optoelectronic devices, benefiting from the spatial separation of photogenerated electron‐hole pairs. Notably, the electronic properties and contact characteristics of the HfS2${\rm HfS}_2$/MoS2${\rm MoS}_2$ vdWH are controllable under electric gating. The negative electric gating facilitates to a transformation from type‐II to type‐I band alignment, while the positive electric field induces a shift from semiconductor to metal in the HfS2${\rm HfS}_2$/MoS2${\rm MoS}_2$ vdWH. This findings can provide valuable insights into the fundamental aspects that contribute to the exceptional performance observed in HfS2${\rm HfS}_2$/MoS2${\rm MoS}_2$ vdWH toward high‐performance multifunctional devices. [ABSTRACT FROM AUTHOR]

BMP6 is a central cytokine in the induction of Sjogren's syndrome-associated (SS-associated) secretory hypofunction. However, the upstream initiation leading to the production of this cytokine in SS is unknown. In this study, RNA ISH on salivary gland sections taken from patients with SS indicated monocytic lineage cells as a cellular source of BMP6. RNA-Seq data on human salivary glands suggested that TLR4 signaling was an upstream regulator of BMP6, which was confirmed by in vitro cell assays and single-cell transcriptomics of human PBMCs. Further investigation showed that HSP70 was an endogenous natural TLR4 ligand that stimulated BMP6 expression in SS. Release of HSP70 from epithelial cells could be triggered by overexpression of lysosome-associated membrane protein 3 (LAMP3), a protein also associated with SS in several transcriptome studies. In vitro studies supported the idea that HSP70 was released as a result of lysosomal exocytosis initiated by LAMP3 expression, and reverse transcription PCR on RNA from minor salivary glands of patients with SS confirmed a positive correlation between BMP6 and LAMP3 expression. BMP6 expression could be experimentally induced in mice by overexpression of LAMP3, which developed an SS-like phenotype. The newly identified LAMP3/HSP70/BMP6 axis provided an etiological model for SS gland dysfunction and autoimmunity., Introduction Sjogren's syndrome (SS) is an autoimmune disease characterized by dry mouth and/or eye symptoms (sicca symptoms) and lymphocytic inflammation in salivary and/or lacrimal glands. The pathogenetic mechanism driving the [...]

The functionality of electronic and optoelectronic devices relying on two‐dimensional (2D) materials can be substantially influenced by the characteristics of their electrical contacts. Herein, a metal–semiconductor electrical contact between metallic NbS2 and semiconducting MoSe2 monolayer is constructed using first‐principles calculations. The electronic properties and contact characteristics of the NbS2/MoSe2 heterostructure as well as the effects of electric fields and in‐plane strains are also explored. These results indicate that the NbS2/MoSe2 heterostructure exhibits the p$p$‐type Schottky contact (ShC) with low Schottky barriers and possesses low contact resistance of the tunneling barrier. Furthermore, the electronic properties and contact characteristics of the NbS2/MoSe2 heterostructure can be fine‐tuned through the application of in‐plane strains and electric fields. The electric fields give rise to the transformation from p$p$‐type to n$n$‐type ShC as well as the conversion from ShC to Ohmic contact (OhC) in the NbS2/MoSe2 heterostructure. Similarly, in‐plane strains play a role in direct‐to‐indirect band gap transitions and further contribute to the conversion from ShC to OhC in the NbS2/MoSe2 heterostructure. These findings offer valuable theoretical insights that can guide the practical utilization of the NbS2/MoSe2 vdW‐MSH in the development of next‐generation electronic and optoelectronic devices. [ABSTRACT FROM AUTHOR]

A significant problem in the area of rechargeable alkali ion battery technologies is the exploration of anode materials with overall high specific capacities and superior physical properties. By using first-principles calculations, we have determined that monolayer TiSi2N4 is precisely such a potential anode candidate. Its demonstrated dynamic, thermal, mechanical, and energetic stabilities make it feasible for experimental realization. An important benefit of the electrode conductivity is that the electronic structure reveals that the pristine system experiences a change from a semiconductor to a metal throughout the entire alkali adsorption process. What's more interesting is that monolayer TiSi2N4 can support up to double-sided 3-layer ad-atoms, resulting in extremely high theoretical capacities for Li, Na, Mg, and K of 1004, 854, 492 and 531 mA h g−1 and low average open-circuit voltages of 0.55, 0.25, 0.55, and −1.3 V, respectively. Alkali diffusion on the surface has been demonstrated to occur extremely quickly, with migration energy barriers for Li, Na, Mg, and K as low as 0.25, 0.14, 0.10, and 0.07 eV, respectively. The results reveal that the migration barrier energy is the lowest for Li and Mg from path-2 and Na and K from path-1. Overall, these findings suggest that monolayer TiSi2N4 is a suitable anode candidate for use in high-performance and low-cost metal-ion batteries. [ABSTRACT FROM AUTHOR]