Photobiocatalytic Platform for the Efficient Enantio-Divergent Synthesis of β-Fluoromethylated Ketones.

β-Fluoromethyl (CHF, CHF, and CF)-substituted chiral ketones are essential moieties and are vital building blocks in pharmaceutical and agrochemistry. However, general and convenient methods for enantio-diverse access to diverse β-fluoromethylated ketones are lacking, hindering the further development of these functional moieties. In this study, we developed an ene-reductase-based photobiocatalytic platform for efficient synthesis of enantio-divergent β-fluoromethylated chiral ketones.

Unlocking mild-condition benzene ring contraction using nonheme diiron -oxygenase.

Benzene ring contractions are useful yet rare reactions that offer a convenient synthetic route to various valuable chemicals. However, the traditional methods of benzene contraction rely on noble-metal catalysts under extreme conditions with poor efficiency and uncontrollable selectivity. Mild-condition contractions of the benzene ring are rarely reported.

Hantzsch Ester as Efficient and Economical NAD(P)H Mimic for In Vitro Bioredox Reactions.

Biocatalysis has emerged as a valuable and reliable tool for industrial and academic societies, particularly in fields related to bioredox reactions. The cost of cofactors, especially those needed to be replenished at stoichiometric amounts or more, is the chief economic concern for bioredox reactions. In this study, a readily accessible, inexpensive, and bench-stable Hantzsch ester is verified as the viable and efficient NAD(P)H mimic by four enzymatic redox transformations, including two non-heme diiron N-oxygenases and two flavin-dependent reductases.

Local Modulation of Antigen-Presenting Cell Development after Resolution of Pneumonia Induces Long-Term Susceptibility to Secondary Infections.

Lung infections cause prolonged immune alterations and elevated susceptibility to secondary pneumonia. We found that, after resolution of primary viral or bacterial pneumonia, dendritic cells (DC), and macrophages exhibited poor antigen-presentation capacity and secretion of immunogenic cytokines. Development of these "paralyzed" DCs and macrophages depended on the immunosuppressive microenvironment established upon resolution of primary infection, which involved regulatory T (Treg) cells and the cytokine TGF-β.

Detecting the Curvature of de Sitter Universe with Two Entangled Atoms.

Casimir-Polder interaction arises from the vacuum fluctuations of quantum field that depend on spacetime curvature and thus is spacetime-dependent. Here we show how to use the resonance Casimir-Polder interaction (RCPI) between two entangled atoms to detect spacetime curvature. We find that the RCPI of two static entangled atoms in the de Sitter-invariant vacuum depends on the de Sitter spacetime curvature relevant to the temperature felt by the static observer.

Relativistic quantum metrology in open system dynamics.

Quantum metrology studies the ultimate limit of precision in estimating a physical quantity if quantum strategies are exploited. Here we investigate the evolution of a two-level atom as a detector which interacts with a massless scalar field using the master equation approach for open quantum system. We employ local quantum estimation theory to estimate the Unruh temperature when probed by a uniformly accelerated detector in the Minkowski vacuum.

Quantum metrology and estimation of Unruh effect.

We study the quantum metrology for a pair of entangled Unruh-Dewitt detectors when one of them is accelerated and coupled to a massless scalar field. Comparing with previous schemes, our model requires only local interaction and avoids the use of cavities in the probe state preparation process. We show that the probe state preparation and the interaction between the accelerated detector and the external field have significant effects on the value of quantum Fisher information, correspondingly pose variable ultimate limit of precision in the estimation of Unruh effect.

Neonatal Fc receptor (FcRn): a novel target for therapeutic antibodies and antibody engineering.

The biomedical applications of antibodies as prophylactics, therapeutics and diagnostics are developing rapidly. Neonatal Fc receptor (FcRn) is a major IgG Fc receptor capable of facilitating the translocation of IgG. FcRn can protect IgG from intracellular catabolism, thereby increasing its half-life.

Distribution of rat neonatal Fc receptor in the principal organs of neonatal and pubertal rats.

The neonatal Fc receptor (FcRn) mediates the transfer of IgG and albumin, also protects them from catabolism. This study characterized the expression of FcRn in different organs of neonatal and pubertal rats by reverse transcription-PCR (RT-PCR) and immunohistochemistry, demonstrates that FcRn is expressed in liver, kidney, intestine, heart, lung, spleen, skin and skeletal muscles at varying levels post-gestation from d 1 to d 63. This finding is contrary to previous studies claiming that FcRn is undetectable in most tissues after weaning.

Progress on research of chicken IgY antibody-FcRY receptor combination and transfer.

The transfer of maternal immunoglobulins (Igs) plays a significant role in fetal initial humoral immunity, of which process has changed and diversified during the evolution of vertebrates. IgY is a key molecular in antibody evolution which links ancient Igs and mammalian Igs such as IgG and IgE. IgY's transfer to the embryo is a two-step receptor-mediated process, including the transfer from the maternal bloodstream to the yolk sac, and from the yolk sac to the embryo.