Infinitesimal optical singularity ruler for three-dimensional picometric metrology.

Optical metrology with picometer-scale precision in three-dimensional space is of considerable importance in modern physics and state of the art technology, optical interference is an effective method, but techniques with rapid spatial variation have the potential to enhance measurement precision, which will be required as measurement dimensions decrease. Here, the concept of the vanishingly small optical phase singularity ruler is introduced. Inspired by the well-known plumb-line technique used to locate the centroid, an analogous singularity line technique is proposed to locate the optical singularity with a precision of ~4.

TRAF6-mediated ubiquitination of AKT1 in the nucleus occurs in a β-arrestin2-dependent manner upon insulin stimulation.

AKT, also known as protein kinase B (PKB), serves as a crucial regulator of numerous biological functions, including cell growth, metabolism, and tumorigenesis. Increasing evidence suggests that the kinase activity of AKT is regulated via ubiquitination by various E3 ligase enzymes in response to different stimuli. However, the molecular mechanisms underlying insulin-induced AKT ubiquitination are not yet fully understood.

Dorsal raphe nucleus to basolateral amygdala 5-HTergic neural circuit modulates restoration of consciousness during sevoflurane anesthesia.

The advent of general anesthesia (GA) has significant implications for clinical practice. However, the exact mechanisms underlying GA-induced transitions in consciousness remain elusive. Given some similarities between GA and sleep, the sleep-arousal neural nuclei and circuits involved in sleep-arousal, including the 5-HTergic system, could be implicated in GA.

TRAF6-mediated ubiquitination of AKT in the nucleus is a critical event underlying the desensitization of G protein-coupled receptors.

Background: Desensitization of G protein-coupled receptors (GPCRs) refers to the attenuation of receptor responsiveness by prolonged or intermittent exposure to agonists. The binding of β-arrestin to the cytoplasmic cavity of the phosphorylated receptor, which competes with the G protein, has been widely accepted as an extensive model for explaining GPCRs desensitization. However, studies on various GPCRs, including dopamine D-like receptors (DR, DR, DR), have suggested the existence of other desensitization mechanisms.

All-optically controlled holographic plasmonic vortex array for multiple metallic particles manipulation.

Due to the sub-diffraction-limited size and giant field enhancement, plasmonic tweezers have a natural advantage in trapping metallic particles. However, the strict excitation condition makes it difficult to generate an arbitrary plasmonic field in a controllable manner, thus narrowing its practical applications. Here, we propose an all-optical plasmonic field shaping method based on a digital holographic algorithm and generate plasmonic vortex arrays with controllable spot numbers, spatial location, and topological charge.

Switchable rotation of metal nanostructures in an intensity chirality-invariant focus field.

Light-induced rotation is a fundamental motion form that is of great significance for flexible and multifunctional manipulation modes. However, current optical rotation by a single optical field is mostly unidirectional, where switchable rotation manipulation is still challenging. To address this issue, we demonstrate a switchable rotation of non-spherical nanostructures within a single optical focus field.

Generation of discrete higher-order optical vortex lattice at focus.

Higher-order vortices (HOVs) extend the dimensions of optical vortex regulation, which is of great significance in optical communication and optical tweezers. Herein, we demonstrate an alternative scheme to produce a HOV in the focus plane using multiple Laguerre-Gaussian (LG) beam interference, termed a discrete higher-order optical vortex lattice (DHOVL). The modulation depth of the DHOVL exceeds 2π.

The States of Different 5-HT Receptors Located in the Dorsal Raphe Nucleus Are Crucial for Regulating the Awakening During General Anesthesia.

General anesthesia is widely used in various clinical practices due to its ability to cause loss of consciousness. However, the exact mechanism of anesthesia-induced unconsciousness remains unclear. It is generally thought that arousal-related brain nuclei are involved.

Ubiquitination of GRK2 Is Required for the β-Arrestin-Biased Signaling Pathway of Dopamine D2 Receptors to Activate ERK Kinases.

A class-A GPCR dopamine D2 receptor (D2R) plays a critical role in the proper functioning of neuronal circuits through the downstream activation of both G-protein- and β-arrestin-dependent signaling pathways. Understanding the signaling pathways downstream of D2R is critical for developing effective therapies with which to treat dopamine (DA)-related disorders such as Parkinson's disease and schizophrenia. Extensive studies have focused on the regulation of D2R-mediated extracellular-signal-regulated kinase (ERK) 1/2 signaling; however, the manner in which ERKs are activated upon the stimulation of a specific signaling pathway of D2R remains unclear.

Noradrenergic pathway from the locus coeruleus to heart is implicated in modulating SUDEP.

Sudden unexpected death in epilepsy (SUDEP) is the leading cause of death among epilepsy patients. However, the underlying mechanism remains elusive. Seizure-induced respiratory arrest (S-IRA) is recognized as a main cause of SUDEP, but the contribution of other factors such as cardiac arrhythmias cannot be excluded.

Protocol for modulation of the serotonergic DR-PBC neural circuit to prevent SUDEP in the acoustic and PTZ-induced DBA/1 mouse models of SUDEP.

The dorsal raphe nucleus (DR) and the pre-Bötzinger complex (PBC) may play an important role in regulating seizure-induced respiratory arrest (S-IRA), the main contributor to sudden unexpected death in epilepsy. Here, we describe pharmacological, optogenetic, and retrograde labeling approaches to specifically modulate the DR to PBC serotonergic pathway. We detail steps for implanting optical fibers and viral infusion into DR and PBC regions and optogenetic techniques for exploring the role of 5-hydroxytryptophan (5-HT) neural circuit of DR-PBC in S-IRA.

Dorsal raphe nucleus to pre-Bötzinger complex serotonergic neural circuit is involved in seizure-induced respiratory arrest.

Sudden unexpected death in epilepsy (SUDEP) is the leading cause of death among patients with epilepsy. However, the underlying mechanism of SUDEP remains elusive. Previous studies showed seizure-induced respiratory arrest (S-IRA) is the main factor in SUDEP, and that enhancement of serotonin (5-HT) function in the dorsal raphe nucleus (DR) can significantly reduce the incidence of S-IRA in the DBA/1 mouse model of SUDEP.

Time-varying orbital angular momentum in tight focusing of ultrafast pulses.

The orbital angular momentum (OAM) of light has important applications in a variety of fields, including optical communication, quantum information, super-resolution microscopic imaging, particle trapping, and others. However, the temporal properties of OAM in ultrafast pulses and in the evolution process of spin-orbit coupling has yet to be revealed. In this work, we theoretically studied the spatiotemporal property of time-varying OAM in the tightly focused field of ultrafast light pulses.

Energy flow inversion in an intensity-invariant focusing field.

Dependence of light intensity on energy flow is the most intuitive presentation of an optical field. This dependence, however, also limits the applications to the interaction of the light field with matter. For further insight into this, we demonstrate a novel case of the optical field, named as the counterintuitive chiral intensity field (CCIF), in the highly focusing situation: the energy flow reverses during the propagation but the intensity distribution pattern is kept approximately invariant.

Controllable propagation and transformation of chiral intensity field at focus.

As an intrinsic feature of the optical field, chirality could induce many novel phenomena due to the interaction between chiral light and matter. Thus, the generation of optical fields possessing 2D or 3D chiral intensity patterns, called chiral intensity fields, has been widely studied. However, the control of chiral intensity field along the optical axis is still a challenge.

VGLUT2/Cdk5/p25 Signaling Pathway Contributed to Inflammatory Pain by Complete Freund's Adjuvant.

Vesicular glutamate transporter type 2 (VGLUT2) is known to play an important role in mediating heat hyperalgesia induced by inflammation. However, the underlying mechanism for this activity is poorly understood. Cyclin-dependent kinase 5 (Cdk5), serving as a key regulator in modulating release of glutamate, acted a key player in the formation of heat hyperalgesia of inflammatory pain.

Grafted optical vortex with controllable orbital angular momentum distribution.

In an optical vortex (OV) field, the orbital angular momentum (OAM) distribution strongly depends on the intensity, which results in difficulty in OAM independent modulation. To overcome this limitation, we propose a grafted optical vortex (GOV) via spiral phase reconstruction of two or more OVs with different topological charges (TCs). To remain the annular shape of the GOV's intensity, the Dirac δ-function is employed to restrict the energy in a ring.

Optical vortex shaping via a phase jump factor.

Topological charge (TC) of an optical vortex (OV) is a crucial parameter. We propose two factors, namely, the phase jump factor and the phase gradient factor, to replace the parameter of TC through unwrapping the TC definition integral. Based on these two factors, we report on a novel OV, referred to as the remainder-phase optical vortex (ROV).

Close-packed optical vortex lattices with controllable structures.

As a spatial structured light field, the optical vortex (OV) has attracted extensive attention in recent years. In practice, the OV lattice (OVL) is an optimal candidate for applications of orbital angular momentum (OAM)-based optical communications, microparticle manipulation, and micro/nanofabrication. However, traditional methods for producing OVLs meet a significant challenge: the OVL structures cannot be adjusted freely and form a close-packed arrangement, simultaneously.

Controllable mode transformation in perfect optical vortices.

We report a novel method to freely transform the modes of a perfect optical vortex (POV). By adjusting the scaling factor of the Bessel-Gauss beam at the object plane, the POV mode transformation can be easily controlled from circle to ellipse with a high mode purity. Combined with the modulation of the cone angle of an axicon, the ellipse mode can be freely adjusted along the two orthogonal directions.

In situ measurement of the topological charge of a perfect vortex using the phase shift method.

We propose a method to determine the topological charge (TC) of a perfect vortex. With the phase shift technique, the perfect vortex and its conjugate beam exactly overlap and interfere. Consequently, the TC of a perfect vortex is determined by counting the number of interference fringes.