Photochemical Reaction Enabling the Engineering of Photonic Spin-Orbit Coupling in Organic-Crystal Optical Microcavities.

The control and active manipulation of spin-orbit coupling (SOC) in photonic systems are fundamental in the development of modern spin optics and topological photonic devices. Here, we demonstrate the control of an artificial Rashba-Dresselhaus (RD) SOC mediated by photochemical reactions in a microcavity filled with an organic single crystal of photochromic phase-change character. Splitting of the circular polarization components of the optical modes induced by photonic RD SOC is observed experimentally in momentum space. By applying an ultraviolet light beam, we control the spatial molecular orientation through a photochemical reaction, and with that we control the energies of the photonic modes. This way, we realize a reversible conversion of spin splitting of the optical modes with different energies, leading to an optically controlled switching between circularly and linearly polarized optical modes in our device. Our strategy of in situ and reversible engineering of SOC induced by a light field provides a promising approach to actively design and manipulate synthetic gauge fields toward future on-chip integration in photonics and topological photonic devices.

Novel affibody molecules as potential agents in molecular imaging for MAGE-A3-positive tumor diagnosis.

BACKGROUND: The cancer-testis protein melanoma antigen A3 (MAGE-A3) is highly expressed in a broad range of malignant tumor forms. It has been confirmed that affibody molecules, a novel family of small (∼6.5 kDa) targeting proteins, are useful agents for molecular imaging and targeted tumor treatment. As a novel agent for in vivo molecular imaging detection of MAGE-A3-positive tumors, the efficacy of affibody molecules was assessed in this research. METHODS: In this study, three cycles of phage display library screening resulted in the isolation of two new affibody molecules (ZMAGE-A3:172 and ZMAGE-A3:770) that attach to MAGE-A3. These molecules were then expressed in bacteria and purified. The affibody molecules with high affinity and specificity were evaluated using western blotting, immunohistochemistry, indirect immunofluorescence, surface plasmon resonance, and near-infrared optical imaging of tumor-bearing nude mice. RESULTS: The selected ZMAGE-A3 affibodies can precisely bind to the MAGE-A3 protein in living cells and display high-affinity binding to the MAGE-A3 protein at the molecular level. Furthermore, the accumulation of DyLight755-labeled ZMAGE-A3:172 or ZMAGE-A3:770 in MAGE-A3-positive tumors was achieved as early as 30 min and disappeared at 48 h post-injection. CONCLUSION: Our findings support the potential of the two MAGE-A3 protein-binding affibody molecules for their use as molecular imaging agents.

Room-Temperature Electrical Field-Enhanced Ultrafast Switch in Organic Microcavity Polariton Condensates.

Integrated electro-optical switches are essential as one of the fundamental elements in the development of modern optoelectronics. As an architecture for photonic systems exciton polaritons, hybrid bosonic quasiparticles that possess unique properties derived from both excitons and photons, have shown much promise. For this system, we demonstrate a significant improvement of emitted intensity and condensation threshold by applying an electric field to a microcavity filled with an organic microbelt. Our theoretical investigations indicate that the electric field makes the excitons dipolar and induces an enhancement of the exciton-polariton interaction and of the polariton lifetime. Based on these electric field-induced changes, a sub-nanosecond electrical field-enhanced polariton condensate switch is realized at room temperature, providing the basis for developing an on-chip integrated photonic device in the strong light-matter coupling regime.

Circularly Polarized Laser Emission from Homochiral Superstructures based on Achiral Molecules with Conformal Flexibility.

Without external chiral intervention, it is a challenge to form homochirality from achiral molecules with conformational flexibility. We here report on a rational strategy that uses multivalent noncovalent interactions to clamp the molecular conformations of achiral D-A molecules. These interactions overcome the otherwise dominant dipole-dipole interactions and thus disfavor their symmetric antiparallel stacking. It in turn facilitates parallel packing, leading to spontaneous symmetry breaking during crystallization and thus the formation of homochiral conglomerates. When this emergent homochirality is coupled with optical gain characteristics of the molecules, the homochiral crystals are explored as excellent circularly polarized micro-lasers with low lasing threshold (16.4 µJ cm-2 ) and high dissymmetry factor glum (0.9). This study therefore provides a facile design strategy for supramolecular chiral materials and active laser ones without the necessity of intrinsic chiral element.

Helical Polariton Lasing from Topological Valleys in an Organic Crystalline Microcavity.

Topological photonics provides an important platform for the development of photonic devices with robust disorder-immune light transport and controllable helicity. Mixing photons with excitons (or polaritons) gives rise to nontrivial polaritonic bands with chiral modes, allowing the manipulation of helical lasers in strongly coupled light-matter systems. In this work, helical polariton lasing from topological valleys of an organic anisotropic microcrystalline cavity based on tailored local nontrivial band geometry is demonstrated. This polariton laser emits light of different helicity along different angular directions. The significantly enhanced chiral characteristics are achieved by the nonlinear relaxation process. Helical topological polariton lasers may provide a perfect platform for the exploration of novel topological phenomena that involve light-matter interaction and the development of polariton-based spintronic devices.

Significant growth inhibition by a bispecific affibody targeting oncoprotein E7 in both HPV16 and 18 positive cervical cancer in vitro and in vivo.

The infection with HPV 16 and 18 high-risk types account for more than 80 % of cervical cancer incidence, but there is still no targeted agent against HPV for cervical cancer therapy. Our previous study constructed a bispecific affibody Z16-18 targeting HPV16 and 18 early antigen 7 (E7, responsible for the infected cell malignant transformation). In the present study, we prepared Z16-18 in prokaryotic expression system and confirmed its significant growth inhibition both on SiHa (HPV16 positive) and HeLa (HPV18 positive) cervical cancer cells by arresting cell cycle at G0/G1 phase. The IC50 of Z16-18 on SiHa and HeLa were close in value. Z16-18 could specifically target E7 in both SiHa and HeLa, and exhibited prominent targeted enrichment on tumor tissues derived from SiHa or HeLa, resulting in the inhibition of tumourigenesis and tumour growth in vivo. Furthermore, Z16-18 could inhibit the interaction between E7 and pRb to block the E7-pRb carcinogenic pathway, resulting in the decreased release of E2F and the cell growth inhibition characterized by the decrease of CDK6 and Cyclin D1. This study provides a new strategy for targeted therapy based on affibody, and Z16-18 has great potential for utilisation and development as an agent targeting HPV16 and HPV18 related cervical cancer.

Effect of Short-Term Preoperative Parenteral Nutrition Support for Gastric Cancer Patients with Sarcopenia: a Propensity Score Matching Analysis.

INTRODUCTION: Sarcopenia is well recognized as an unfavorable prognostic marker for gastric cancer (GC) patients. Currently, few nutritional interventions-such as parenteral nutrition-exist for the treatment of patients with sarcopenia. This study aimed to estimate the effectiveness of short-term preoperative parenteral nutrition (PN) in GC patients with sarcopenia. MATERIALS AND METHODS: We collected data on GC patients with sarcopenia who underwent radical gastrectomy at our hospital from 2010 to 2018. A 1:1 ratio propensity score matching (PSM) was applied to establish the PN and control groups. Data were analyzed using the chi-squared, Mann-Whitney U, and Fisher's exact tests. RESULTS: In total, 428 patients met the inclusion criteria, and the propensity scores identified 166 matched pairs of patients with sarcopenia. The overall incidence of postoperative complications between both groups was not significantly different (P = 0.728). The PN group had a lower rate of intra-abdominal infection (P = 0.032) and higher hospitalization costs (P < 0.001) than the control group. Multivariate analysis demonstrated that age, Charlson score, and TNM stage were independent risk factors for postoperative complications. Additionally, subgroup analysis revealed that short-term preoperative PN support is associated with decreased postoperative surgical complications in patients with albumin levels < 35 g/L (P = 0.025). CONCLUSION: Short-term preoperative PN support is not associated with reduction of overall complication rate in patients with GC and sarcopenia. However, those with sarcopenia and hypoalbuminemia benefited from preoperative PN support.

Comprehensive Analysis to Identify MAGEA3 Expression Correlated With Immune Infiltrates and Lymph Node Metastasis in Gastric Cancer.

Gastric cancer (GC) is an aggressive malignant tumor and causes a significant number of deaths every year. With the coming of the age of cancer immunotherapy, search for a new target in gastric cancer may benefit more advanced patients. Melanoma-associated antigen-A3 (MAGEA3), one of the members of the cancer-testis antigen (CTA) family, was considered an important part of cancer immunotherapy. We evaluate the potential role of MAGEA3 in GC through the TCGA database. The result revealed that MAGEA3 is upregulated in GC and linked to poor OS and lymph node metastasis. MAGEA3 was also correlated with immune checkpoints, TMB, and affected the tumor immune microenvironment and the prognosis of GC through CIBERSORT, TIMER, and Kaplan-Meier plotter database analysis. In addition, GSEA-identified MAGEA3 is involved in the immune regulation of GC. Moreover, the protein-protein interaction (PPI) networks of MAGEA3 were constructed through STRING database and MAGEA3-correlated miRNAs were screened based on the joint analysis of multiple databases. In terms of experimental verification, we constructed pET21a (+)/MAGEA3 restructuring plasmids and transformed to Escherichia coli Rosetta. MAGEA3 protein was used as an antigen after being expressed and purified and can effectively detect the specific IgG in 93 GC patients' serum specimens with 44.08% sensitivity and 92.54% specificity. Through further analysis, the positive rate of MAGEA3 was related to the stage and transfer number of lymph nodes. These results indicated that MAGEA3 is a novel biomarker and correlated with lymph node metastasis and immune infiltrates in GC, which could be a new target for immunotherapy.

Experimental Measurement of the Divergent Quantum Metric of an Exceptional Point.

The geometry of Hamiltonian's eigenstates is encoded in the quantum geometric tensor (QGT), containing both the Berry curvature, central to the description of topological matter, and the quantum metric. So far, the full QGT has been measured only in Hermitian systems, where the role of the quantum metric is mostly limited to corrections. On the contrary, in non-Hermitian systems, and, in particular, near exceptional points, the quantum metric is expected to diverge and to often play a dominant role, for example, in the enhanced sensing and in wave packet dynamics. In this Letter, we report the first experimental measurement of the quantum metric in a non-Hermitian system. The specific platform under study is an organic microcavity with exciton-polariton eigenstates, which demonstrate exceptional points. We measure the quantum metric's divergence, and we determine the scaling exponent n=-1.01±0.08, which is in agreement with the theoretical description of second-order exceptional points.

Nontrivial band geometry in an optically active system.

Optical activity, also called circular birefringence, is known for two hundred years, but its applications for topological photonics remain unexplored. Unlike the Faraday effect, the optical activity provokes rotation of the linear polarization of light without magnetic effects, thus preserving the time-reversal symmetry. In this work, we report a direct measurement of the Berry curvature and quantum metric of the photonic modes of a planar cavity, containing a birefringent organic microcrystal (perylene) and exhibiting emergent optical activity. This experiment, performed at room temperature and at visible wavelength, establishes the potential of organic materials for implementing non-magnetic and low-cost topological photonic devices.

Efficient Bosonic Condensation of Exciton Polaritons in an H-Aggregate Organic Single-Crystal Microcavity.

Although organic polariton condensation has been recently demonstrated, they only utilize the photon part of polaritons and ignore the excitonic contribution because the polariton-polariton and polariton-reservoir interactions are weak in organic microcavities owing to the absence of Coulomb exchange-interactions between Frenkel excitons. We demonstrate highly efficient and strongly polarization-dependent polariton condensates in a microcavity consisting of an H-aggregate organic single-crystalline microbelt sandwiched between two silver reflectors. Benefitting from the advantages of vibronic coupling in H-aggregates and heavy exciton-like polaritons, both macroscopic coherent polariton ground-state population and high-energy quantized-modes are observed. The measurements are qualitatively reproduced based on simulations of the spatiotemporal polariton dynamics. The observation of low threshold polariton lasing, the ease of fabrication, and the potential for efficient electronic charge injection make microcrystals of organic semiconductors attractive candidates for continuous wave and electrically pumped functional photonic polariton circuits and organic polariton lasers, operating at room temperature.

Learning Hybrid Representation by Robust Dictionary Learning in Factorized Compressed Space.

In this paper, we investigate the robust dictionary learning (DL) to discover the hybrid salient low-rank and sparse representation in a factorized compressed space. A Joint Robust Factorization and Projective Dictionary Learning (J-RFDL) model is presented. The setting of J-RFDL aims at improving the data representations by enhancing the robustness to outliers and noise in data, encoding the reconstruction error more accurately and obtaining hybrid salient coefficients with accurate reconstruction ability. Specifically, J-RFDL performs the robust representation by DL in a factorized compressed space to eliminate the negative effects of noise and outliers on the results, which can also make the DL process efficient. To make the encoding process robust to noise in data, J-RFDL clearly uses sparse L2, 1-norm that can potentially minimize the factorization and reconstruction errors jointly by forcing rows of the reconstruction errors to be zeros. To deliver salient coefficients with good structures to reconstruct given data well, J-RFDL imposes the joint low-rank and sparse constraints on the embedded coefficients with a synthesis dictionary. Based on the hybrid salient coefficients, we also extend J-RFDL for the joint classification and propose a discriminative J-RFDL model, which can improve the discriminating abilities of learnt coefficients by minimizing the classification error jointly. Extensive experiments on public datasets demonstrate that our formulations can deliver superior performance over other state-of-the-art methods.

Organic-Inorganic Hybrid Perovskite Nanowire Laser Arrays.

Fabrication of semiconductor nanowire laser arrays is very challenging, owing to difficulties in direct monolithic growth and patterning of III-V semiconductors on silicon substrates. Recently, methylammonium lead halide perovskites (MAPbX3, X = Cl, Br, I) have emerged as an important class of high-performance solution-processed optoelectronic materials. Here, we combined the "top-down" fabricated polydimethylsiloxane rectangular groove template (RGT) with the "bottom-up" solution self-assembly together to prepare large-scale perovskite nanowire (PNW) arrays. The template confinement effect led to the directional growth of MAPbX3 along RGTs into PNWs. We achieved precise control over not only the dimensions of individual PNWs (width 460-2500 nm; height 80-1000 nm, and length 10-50 µm) but also the interwire distances. Well-defined dimensions and uniform geometries enabled individual PNWs to function as high-quality Fabry-Perot nanolasers with almost identical optical modes and similarly low-lasing thresholds, allowing them to ignite simultaneously as a laser array. Optical tests demonstrated that PNW laser arrays exhibit good photostabillity with an operation duration exceeding 4 × 107 laser pulses. Precise placement of PNW arrays at specific locations makes our method highly compatible with lithographic techniques, which are important for integrating PNW electronic and photonic circuits.