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Optoelectronic functional materials with flexible and in-plane anisotropic properties has been a significant development direction of nanotechnology due to wearable and polarized optoelectronic applications. Herein, the elasticity, global band dispersion, optical dielectric properties of environmentally friendly IVB-VIA layered transition metal trichalcogenides (MX3, M = Zr, Hf; X = S, Se) are investigated systematically by density functional theory with different kinds of van der Waals correction and hybrid functional. The low elastic modulus suggests that they are appropriate for the design of flexible optoelectronic devices. Originating from the effect of d states of chalcogens and s states of transition metals, the dispersion of the valence band edge of monolayer MX3 shows that the effective mass of carriers along the wave vector kx is much heavier than that of carriers along the wave vector ky. This means that the mobility of carriers exhibits obvious in-plane anisotropy. Meanwhile, the optical dielectric properties of monolayer MX3 as well as absorbed photon flux (Jabs) of the related heterostructures display noteworthy in-plane anisotropy in the visible-IR region. The ratio of Jabs from different direction reaches up to 1.7. This work could not only promote understanding of rich photophyiscal properties of transition metal trichalcogenides, but also provide a theoretical reference for the invention of high-performance optoelectronic devices with high flexibility and anisotropy. [ABSTRACT FROM AUTHOR]

Transition metal dichalcogenides have been widely utilized as nonlinear optical materials for laser pulse generation applications. Herein, we study the nonlinear optical properties of a VS2-based optical device and its application as a new saturable absorber (SA) for high-power pulse generation. Few-layer VS2 nanosheets are deposited on the tapered region of a microfiber to form an SA device, which shows a modulation depth of 40.52%. After incorporating the microfiber-VS2 SA into an Er-doped fiber laser cavity, passively Q-switched pulse trains could be obtained with repetition rates varying from 95 to 233 kHz. Under the pump power of 890 mW, the largest output power and shortest pulse duration are measured to be 43 mW and 854 ns, respectively. The high signal-to-noise ratio of 60 dB confirms the excellent stability of the Q-switching state. To the best of our knolowdge, this is the first illustration of using VS2 as an SA. Our experimental results demonstrate that VS2 nanomaterials have a large potential for nonlinear optics applications.

The immune mechanism underlying hepatitis B surface antigen (HBsAg) loss, particularly type I inflammatory response, during pegylated interferon‐α (PEG‐IFN) therapy remains unclear. In this study, we aimed to elucidate such immune mechanisms. Overall, 82 patients with chronic hepatitis B (CHB), including 41 with HBsAg loss (cured group) and 41 uncured patients, received nucleos(t)ide analogue and PEG‐IFN treatments. Blood samples from all patients, liver tissues from 14 patients with CHB, and hepatic perfusate from 8 liver donors were collected for immune analysis. Jurkat, THP‐1 and HepG2.2.15 cell lines were used in cell experiments. The proportion of IFN‐γ+ Th1 cells was higher in the cured group than in the uncured group, which was linearly correlated with HBsAg decline and alanine aminotransferase (ALT) levels during treatment. However, CD8+ T cells were weakly associated with HBsAg loss. Serum and intrahepatic levels of Th1 cell‐associated chemokines (C‐X‐C motif chemokine ligand [CXCL] 9, CXCL10, CXCL11, IFN‐γ) were significantly lower in the cured patients than in patients with a higher HBsAg quantification during therapy. Serum from cured patients induced more M1 (CD68+CD86+ macrophage) cells than that from uncured patients. Patients with chronic HBV infection had significantly lower proportions of CD86+ M1 and CD206+ M2 macrophages in their livers than healthy controls. M1 polarization of intrahepatic Kupffer cells promoted HBsAg loss by upregulating the effector function of tissue‐resident memory T cells with increased ALT levels. IFN‐γ+ Th1 activates intrahepatic resident memory T cells to promote HBsAg loss by inducing M1 macrophage polarization. [ABSTRACT FROM AUTHOR]

Benefiting from the attractive high carrier mobility, large absorption coefficient, and ambient stability, group IV–VI compounds show excellent potential applications for optoelectronic devices. Herein, a germanium telluride (GeTe) film with a nanosphere structure has been controllably grown by facile physical vapor deposition and utilized into a photoelectrochemical (PEC)-type photodetector. The GeTe-based PEC-type photodetector possesses an excellent photoresponse and high responsivity in the visible region. Meanwhile, density functional theory calculations were employed to investigate the electronic characteristics of GeTe, supplying evidence of the broadband absorption. The improvement of photoelectric response can be attributed to the thicker films due to the larger light harvesting and higher carrier concentration, which is also verified by the visible–near-infrared absorption spectra and electrochemical impedance spectroscopy. The photocurrent density (Iph) and photoresponsivity (Rph) values of the GeTe-based photodetector can reach 22.8 μA/cm2 and 228.9 μA/W. Generally, our work provides an effective way to extend semiconductor materials in applications of PEC-type photodetectors. [ABSTRACT FROM AUTHOR]

The improvement of optical absorption behavior of the second near‐infrared region (NIR‐II, 1000–1350 nm) based on new function materials is significant for the development of biomedicine and optical imaging. Therefore, the electronic structures and optical absorption of 2H phase MoS2 doped by F, Cl, Br, and I atoms with various doping concentrations are calculated, results show that halogen elements introduced extra transition allowed bands which is about 1.0 eV wide to 2H‐MoS2, and the increasing of impurity concentration can trigger strong spin splits. The transformation of electronic structures leads to 2H‐MoS2 metallic behaviors, improves transition efficiency, and lowers photon energy loss. More importantly, strong light–mass interaction is verified and breaks the energy level degeneracy, makes absorption peaks at 0.6–1.0 eV photon energy region, successfully extends the work region of 2H‐MoS2 to NIR‐II window, greatly improves the optical response and application potential in the photoelectric field. These results not only prove the potential of halogen elements as dopants in bandgap engineering of 2H‐MoS2 but also may indicate a direction for seeking new generation function materials that own excellent performance in the NIR‐II window, which is of great significance to promote the development of optoelectronics and bioimaging applications. [ABSTRACT FROM AUTHOR]

Programmed death-1 receptor ligand 1 (PD-L1) is a promising therapeutic target in aggressive cancers. However, immune landscapes and cancer hallmarks of human PD-[L1.sup.+] tumors as well as their roles in determining therapeutic efficacies are unknown. Here, we showed, in detailed studies of gene data regarding 9769 patients of 32 types of human cancers, that PD-L1 could not exclusively represent the IFN-[gamma] signature and potentially signified proinflammatory myeloid responses in a tumor. PD-L1 heterogeneity endowed by local immune landscapes controlled cancer hallmarks and clinical outcomes of patients. Mechanically, NF-[kappa]B signal elicited by macrophage inflammatory responses generated PD-[L1.sup.+] cancer cells exhibiting capabilities to aggressively survive, support angiogenesis, and metastasize, whereas STAT1 signal triggered by activated T cells induced PD-[L1.sup.+] cancer cells susceptive to apoptosis. Importantly, PD-[L1.sup.+] cancer cells generated by macrophages established great resistance to conventional chemotherapy, cytotoxicity of tumor-specific effector T cells, and therapy of immune-checkpoint blockade. Therapeutic strategy combining immune-checkpoint blockade with macrophage depletion or NF-[kappa]B inhibition in vivo effectively and successfully elicited cancer regression. Our results provide insight into the functional features of PD-[L1.sup.+] tumors and suggest that strategies to influence functional activities of inflammatory cells may benefit immune-checkpoint blockade therapy., Introduction Programmed death-1 receptor (PD-1) or its ligand-1 (PD-L1, B7-H1) is a promising therapeutic target in aggressive cancers (1, 2). PD-1 is mainly expressed by exhausted or suppressive lymphocytes and [...]

The modulation of electrostatic potential and optoelectronic characteristics of Janus MoSSe/MX2 (M = Mo, X = S, Se) van der Waals (vdW) heterostructures with strain engineering were studied by first principles. Based on the effection of uniaxial strain, the electronic properties of heterostructures not only are induced to form direct band gap and indirect band gap and even semiconductor-metal transformation, but also lead to strong interface-built electric field and excellent optical adsorption properties in the range of IR-visible. This work reveals the photophysical properties of MoSSe/MX2 vdW heterostructures as well as shows their strong potential for applications in novel optoelectronic devices and photocatalysis. [ABSTRACT FROM AUTHOR]