Revealing Ultrafast Optical Nonlinearity of Trapped Exciton Polaritons in Atomically Thin Semiconductors.

Nonlinearities are fundamental to modern optical technologies. Exciton polaritons in semiconductor microcavities provide a promising route to strong nonlinearities. Monolayer TMDs, with tightly bound excitons and strong oscillator strength, enable polaritonic phenomena under ambient conditions but face challenges from weak polariton interactions due to small exciton Bohr radius.

Research on the aperture angle-matched collimated illumination method for the dark-state light leakage of LCD target simulators.

Aiming at the problem of overbrightness of the target simulator background for LED backlight panel illumination, a 5° aperture angle-matched collimated illumination method for the target simulator is proposed based on the study of the dark-state leakage of the LCD display device and the scattered stray light of the system. After simulation analysis the method can make the display contrast increase by 3.1 times and solve the problem of dark targets being drowned by the background bright light, which exists in the LED illumination target simulator.

Research on multi-optical axis online compensation alignment method for space environment simulation system.

Aiming at the problem that the error of multi-optical axis alignment is difficult to control in the simulation calibration test, a multi-optical axis dynamic compensation alignment method for the space environment simulation system is proposed. The effect of optical axis disturbance on the signal detection link was analyzed to obtain the alignment accuracy requirements, the optical axis alignment error compensation mechanism was established, the target simulation system with long pupil distance was designed, the alignment error transfer model based on topology structure was constructed, and the test prototype was built. The test results show that the static attitude alignment resolution is better than 3" and the position alignment resolution is better than 11µm.

Research on the background stray light suppression method of a dim target projector based on the orthogonal polarization extinction principle.

Aiming at the problem of background stray light affecting the display of dim target scenes in existing projectors, a stray light suppression optical engine based on a polarizer is proposed. First, the effect of the background stray light of traditional LCOS target projectors on the display of dim targets is analyzed with simulation, and the sources of stray light in the target projector were analyzed as well. Secondly, we theoretically analyze the causes of different stray light paths and stray light polarization states, propose the method of stray light suppression based on the polarizer, and calculate the rotation angle of the polarizer.

Discovery of GuaB inhibitors with efficacy against infection.

Unlabelled: Guanine nucleotides are required for growth and viability of cells due to their structural role in DNA and RNA, and their regulatory roles in translation, signal transduction, and cell division. The natural antibiotic mycophenolic acid (MPA) targets the rate-limiting step in guanine nucleotide biosynthesis executed by inosine-5´-monophosphate dehydrogenase (IMPDH). MPA is used clinically as an immunosuppressant, but whether inhibition of bacterial IMPDH (GuaB) is a valid antibacterial strategy is controversial.

IL-22 alters gut microbiota composition and function to increase aryl hydrocarbon receptor activity in mice and humans.

Background: IL-22 is induced by aryl hydrocarbon receptor (AhR) signaling and plays a critical role in gastrointestinal barrier function through effects on antimicrobial protein production, mucus secretion, and epithelial cell differentiation and proliferation, giving it the potential to modulate the microbiome through these direct and indirect effects. Furthermore, the microbiome can in turn influence IL-22 production through the synthesis of L-tryptophan (L-Trp)-derived AhR ligands, creating the prospect of a host-microbiome feedback loop. We evaluated the impact IL-22 may have on the gut microbiome and its ability to activate host AhR signaling by observing changes in gut microbiome composition, function, and AhR ligand production following exogenous IL-22 treatment in both mice and humans.

Deletion of a previously uncharacterized lipoprotein lirL confers resistance to an inhibitor of type II signal peptidase in .

is a clinically important, predominantly health care-associated gram-negative bacterium with high rates of emerging resistance worldwide. Given the urgent need for novel antibacterial therapies against , we focused on inhibiting lipoprotein biosynthesis, a pathway that is essential for envelope biogenesis in gram-negative bacteria. The natural product globomycin, which inhibits the essential type II signal peptidase prolipoprotein signal peptidase (LspA), is ineffective against wild-type clinical isolates due to its poor penetration through the outer membrane.

Secretes a Bioactive Lipid That Triggers Inflammatory Signaling and Cell Death.

is a highly pathogenic Gram-negative bacterium that causes severe infections with very high fatality rates. infection triggers innate as well as adaptive immunity, however, our understanding of the inflammatory factors secreted by that alarm the immune system remains limited. In this study, we report that the lab adapted and clinical strains of secrete an inflammatory bioactive factor which activates TLR2, leading to canonical IRAK4-dependent NF-κB signaling and production of pro-inflammatory cytokines interleukin (IL)-6 and IL-8 and activation of the inflammasome pathway causing pyroptotic cell death.

Controllable vortex lasing arrays in a geometrically frustrated exciton-polariton lattice at room temperature.

Quantized vortices appearing in topological excitations of quantum phase transition play a pivotal role in strongly correlated physics involving the underlying confluence of superfluids, Bose-Einstein condensates and superconductors. Exciton polaritons as bosonic quasiparticles have enabled studies of non-equilibrium quantum gases and superfluidity. Exciton-polariton condensates in artificial lattices intuitively emulate energy-band structures and quantum many-body effects of condensed matter, underpinning constructing vortex lattices and controlling quantum fluidic circuits.

All-optical switching based on interacting exciton polaritons in self-assembled perovskite microwires.

Ultrafast all-optical switches and integrated circuits call for giant optical nonlinearity to minimize energy consumption and footprint. Exciton polaritons underpin intrinsic strong nonlinear interactions and high-speed propagation in solids, thus affording an intriguing platform for all-optical devices. However, semiconductors sustaining stable exciton polaritons at room temperature usually exhibit restricted nonlinearity and/or propagation properties.

Inhibition of Escherichia coli Lipoprotein Diacylglyceryl Transferase Is Insensitive to Resistance Caused by Deletion of Braun's Lipoprotein.

Lipoprotein diacylglyceryl transferase (Lgt) catalyzes the first step in the biogenesis of Gram-negative bacterial lipoproteins which play crucial roles in bacterial growth and pathogenesis. We demonstrate that Lgt depletion in a clinical uropathogenic Escherichia coli strain leads to permeabilization of the outer membrane and increased sensitivity to serum killing and antibiotics. Importantly, we identify G2824 as the first-described Lgt inhibitor that potently inhibits Lgt biochemical activity and is bactericidal against wild-type Acinetobacter baumannii and E.

Unstable Mechanisms of Resistance to Inhibitors of Escherichia coli Lipoprotein Signal Peptidase.

Clinical development of antibiotics with novel mechanisms of action to kill pathogenic bacteria is challenging, in part, due to the inevitable emergence of resistance. A phenomenon of potential clinical importance that is broadly overlooked in preclinical development is heteroresistance, an often-unstable phenotype in which subpopulations of bacterial cells show decreased antibiotic susceptibility relative to the dominant population. Here, we describe a new globomycin analog, G0790, with potent activity against the type II signal peptidase LspA and uncover two novel resistance mechanisms to G0790 in the clinical uropathogenic strain CFT073.

Interaction of CK1δ with γTuSC ensures proper microtubule assembly and spindle positioning.

Casein kinase 1δ (CK1δ) family members associate with microtubule-organizing centers (MTOCs) from yeast to humans, but their mitotic roles and targets have yet to be identified. We show here that budding yeast CK1δ, Hrr25, is a γ-tubulin small complex (γTuSC) binding factor. Moreover, Hrr25's association with γTuSC depends on its kinase activity and its noncatalytic central domain.

Casein kinase 1 promotes initiation of clathrin-mediated endocytosis.

In budding yeast, over 60 proteins functioning in at least five modules are recruited to endocytic sites with predictable order and timing. However, how sites of clathrin-mediated endocytosis are initiated and stabilized is not well understood. Here, the casein kinase 1 (CK1) Hrr25 is shown to be an endocytic protein and to be among the earliest proteins to appear at endocytic sites.

Ipl1/Aurora-dependent phosphorylation of Sli15/INCENP regulates CPC-spindle interaction to ensure proper microtubule dynamics.

Dynamic microtubules facilitate chromosome arrangement before anaphase, whereas during anaphase microtubule stability assists chromosome separation. Changes in microtubule dynamics at the metaphase-anaphase transition are regulated by Cdk1. Cdk1-mediated phosphorylation of Sli15/INCENP promotes preanaphase microtubule dynamics by preventing chromosomal passenger complex (CPC; Sli15/INCENP, Bir1/Survivin, Nbl1/Borealin, Ipl1/Aurora) association with spindles.

Overlapping kinetochore targets of CK2 and Aurora B kinases in mitotic regulation.

Protein kinase CK2 is one of the most conserved kinases in eukaryotic cells and plays essential roles in diverse processes. While we know that CK2 plays a role(s) in cell division, our understanding of how CK2 regulates cell cycle progression is limited. In this study, we revealed a regulatory role for CK2 in kinetochore function.

A Dam1-based artificial kinetochore is sufficient to promote chromosome segregation in budding yeast.

Kinetochores are large multiprotein complexes that mediate chromosome segregation in all eukaryotes by dynamically connecting specialized chromosome regions, termed centromeres, to the plus-ends of spindle microtubules. Even the relatively simple kinetochores of the budding yeast Saccharomyces cerevisiae consist of more than 80 proteins, making analysis of their respective roles a daunting task. Here, we have developed a system that allows us to artificially recruit proteins to DNA sequences and determine whether they can provide any aspect of kinetochore function in vivo.