snc

Atomically dispersed metal activators (ADMAs) have demonstrated unique advantages in environmental remediation, but how to controllably regulate the active site density and electronic structure of ADMAs to further enhance activation efficiency remains challenging. Here, we introduce a sulfur-atom-doping approach that allows the fine-tuning of atomic Co site content and electronic structure, enabling exploration of density-dependent activation performance of ADMAs for peroxymonosulfate (PMS)-based Fenton-like catalysis...

Most studies on the ventral tegmental area (VTA) and substantia nigra pars compacta (SNc) have focused on dopamine neurons and their role in processes such as motivation, learning, movement, and associated disorders. However there has been increasing attention on other VTA and SNc cell types that release GABA, glutamate, or a combination of these neurotransmitters. Yet the relative distributions and proportions of neurotransmitter-defined cell types across VTA and SNc has remained unclear. Here, we used fluorescent in situ hybridization in male and female mice to label VTA and SNc neurons that expressed mRNA encoding the canonical vesicular transporters for dopamine, GABA, or glutamate: vesicular monoamine transporter VMAT2, vesicular GABA transporter (VGAT), and vesicular glutamate transporter (VGLUT2)...

Successive Negative Contrast (SNC) occurs when there is a reduction in the quantity or quality of a reward that is expected according to the presence of contextual cues. This induces an emotional response of frustration that is similar to stress. While this phenomenon has been observed in several mammal species, findings in domestic dogs have been inconsistent, although this issue has strong relevance in dog training. The aim of this study was to assess the effects of Successive Negative Contrast in two responses that had already been studied in this species, but with an increase in the methodological rigor and variations in the experimental conditions to examine the generalizability of the phenomenon...

Tremor dominant Parkinson's disease (TDPD) and essential tremor plus (ETP) syndrome are commonly encountered tremor dominant neurological disorders. Although the basal ganglia thalamocortical (BGTC) and cerebello thalamocortical (CTC) networks are implicated in tremorogenesis, the extent of functional connectivity alterations across disorders is uncertain. This study aims to evaluate functional connectivity of the BGTC and CTC in TDPD and ETP. Resting state functional MRI was acquired for 25 patients with TDPD, ETP and 22 healthy controls (HC)...

Robust preclinical models of Parkinson's disease (PD) are valuable tools for understanding the biology and treatment of this complex disease. 6-Hydroxydopamine (6-OHDA) is a selective catecholaminergic drug injected into the substantia nigra pars compacta (SNc), medial forebrain bundle (MFB), or striatum, which is then metabolized to induce parkinsonism. Unilateral injection of 6-OHDA produces loss of dopaminergic (DAergic) neurons on the injected side with a marked motor asymmetry known as hemiparkinsonism, typically characterized by a rotational behavior to the impaired side...

BACKGROUND: Sinonasal cancers (SNC) are rare cancers with a high proportion attributable to occupational carcinogens. This study aims to describe the sociodemographic, clinical, and occupational characteristics of subjects with SNC in Brazil. METHODS: Observational study conducted with secondary data from a network of Hospital Cancer Registries. We selected epithelial/unspecified SNC records with a year of diagnosis from 2007 to 2021. We performed descriptive statistics of SNC cases and calculated crude and age-standardized rates (ASR, standard: world population) by gender and Region of residence...

The core pathological event in Parkinson's disease (PD) is the specific dying of dopamine (DA) neurons of the substantia nigra pars compacta (SNc). The reasons why SNc DA neurons are especially vulnerable and why idiopathic PD has only been found in humans are still puzzling. The two main underlying factors of SNc DA neuron vulnerability appear related to high DA production, namely (i) the toxic effects of cytoplasmic DA metabolism and (ii) continuous cytosolic Ca2+ oscillations in the absence of the Ca2+ -buffer protein calbindin...

Parkinson's disease (PD) is the second most prevalent neurodegenerative disease and arises from dopamine (DA) neuron death selectively in the substantia nigra pars compacta (SNc). Rit2 is a reported PD risk allele, and recent single cell transcriptomic studies identified a major RIT2 cluster in PD DA neurons, potentially linking Rit2 expression loss to a PD patient cohort. However, it is still unknown whether Rit2 loss itself impacts DA neuron function and/or viability. Here we report that conditional Rit2 silencing in mouse DA neurons drove motor dysfunction that occurred earlier in males than females and was rescued at early stages by either inhibiting the DA transporter (DAT) or with L-DOPA treatment...

Bone void-filling cements are one of the preferred materials for managing irregular bone voids, particularly in the geriatric population who undergo many orthopedic surgeries. However, bone marrow mesenchymal stem/stromal cells (BM-MSCs) of older-age donors often exhibit reduced osteogenic capacity. Hence, it is crucial to evaluate candidate bone substitute materials with BM-MSCs from the geriatric population to determine the true osteogenic potential, thus simulating the clinical situation. With this concept, we investigated the osteogenic potential of shell nacre cement (SNC), a bone void-filling cement based on shell nacre powder and ladder-structured siloxane methacrylate, using older donor BM-MSCs (age > 55 years) and young donor BM-MSCs (age < 30 years)...

Several brainstem nuclei degenerate in Parkinson's disease (PD). In addition to the well-characterized dopaminergic neurons of the substantia nigra pars compacta (SNc), the cholinergic neurons of the pedunculopontine nucleus (PPN) also degenerate in PD. One leading hypothesis of selective vulnerability is that pacemaking activity and the activation of low-threshold L-type calcium current are major contributors to tonic calcium load and cellular stress in SNc dopaminergic neurons. However, it is not yet clear whether the vulnerable PPN cholinergic neurons share this property...

PURPOSE: Neuromelanin is visualized by optimizing the conditions of longitudinal relaxation (T1)-weighted imaging (T1WI). Although it was originally developed in 2D imaging, 3D imaging has been also reported, and T1WI sequences with magnetization transfer (MT) pulses are now widely used in 3D gradient echo (GRE) sequences. In this study, we assert that the use of spectral presaturation with inversion recovery (SPIR) may also be useful as an alternative to MT pulses, and we optimize SPIR and compare it with MT...

Dopaminergic neurons (DANs) in the substantia nigra pars compacta (SNc) have been related to movement speed, and loss of these neurons leads to bradykinesia in Parkinson's disease (PD). However, other aspects of movement vigor are also affected in PD; for example, movement sequences are typically shorter. However, the relationship between the activity of DANs and the length of movement sequences is unknown. We imaged activity of SNc DANs in mice trained in a freely moving operant task, which relies on individual forelimb sequences...

Degeneration in the substantia nigra (SN) pars compacta (SNc) underlies motor symptoms in Parkinson's disease (PD). Currently, there are no neuroimaging biomarkers that are sufficiently sensitive, specific, reproducible, and accessible for routine diagnosis or staging of PD. Although iron is essential for cellular processes, it also mediates neurodegeneration. MRI can localize and quantify brain iron using magnetic susceptibility, which could potentially provide biomarkers of PD. We measured iron in the SNc, SN pars reticulata (SNr), total SN, and ventral tegmental area (VTA), using quantitative susceptibility mapping (QSM) and R2* relaxometry, in PD patients and age-matched healthy controls (HCs)...

Developing efficient metal-free catalysts to directly synthesize hydrogen peroxide (H2 O2 ) through a 2-electron (2e) oxygen reduction reaction (ORR) is crucial for substituting the traditional energy-intensive anthraquinone process. Here, in-plane topological defects enriched graphene with pentagon-S and pyrrolic-N coordination (SNC) is synthesized via the process of hydrothermal and nitridation. In SNC, pentagon-S and pyrrolic-N originating from thiourea precursor are covalently grafted onto the basal plane of the graphene framework, building unsymmetrical dumbbell-like S─C─N motifs, which effectively modulates atomic and electronic structures of graphene...

Dopamine neurons switch from tonic pacemaker activity to high-frequency bursts in response to salient stimuli. These bursts lead to superlinear increases in dopamine release, and the degree of this increase is highly dependent on firing frequency. The superlinearity and frequency-dependence of dopamine release implicates short-term plasticity processes. The presynaptic Ca2+ -sensor synaptotagmin-7 (SYT7) has suitable properties to mediate such short-term plasticity and has been implicated in regulating dopamine release from somatodendritic compartments ...

Neuromelanin hypopigmentation within substantia nigra pars compacta (SNc) reflects the loss of pigmented neurons, which in turn contributes to the dysfunction of the nigrostriatal and striato-cortical pathways in Parkinson's disease (PD). Our study aims to investigate the relationships between SN degeneration manifested by neuromelanin reduction, functional connectivity (FC) among large-scale brain networks, and motor impairment in PD. This study included 68 idiopathic PD patients and 32 age-, sex- and education level-matched healthy controls who underwent neuromelanin-sensitive magnetic resonance imaging (MRI), functional MRI, and motor assessments...

Previous experiments found that acceptance of saccharin by rats was reduced if they had prior experience of sucrose or some other highly palatable solution. This study tested whether such successive negative contrast (SNC) effects involve acquisition of an aversion to the new taste. In three experiments, rats were switched from sucrose exposure in Stage 1 to a less palatable solution containing a new taste in Stage 2. In Experiments 1 and 2, a novel flavor was added to a saccharin solution at the start of Stage 2...

Owing to its stable graphene-like honeycomb structure, suitable band gap, and nontoxicity, SnC monolayer (ML) has attracted increasing attention in photocatalytic applications. One pertinent obstacle inherent to SnC ML-based photocatalysts has been the high energy barrier in hydrogen evolution reaction (HER) that always requires external energy input and/or strongly acidic conditions. Herein, we propose a two-dimensional (2D) SnC/ZrS2 van der Waals heterostructure (vdWHS) for highly efficient photocatalytic water splitting using first-principles calculations...

BACKGROUND: Guillain-Barré syndrome (GBS) is a condition characterized by acute and progressive weakness that impacts the limbs, facial muscles, and bulbar muscles due to acute polyneuro-radiculopathy. Typically, an infection that results in immune-mediated nerve dysfunction is what starts the disease. Patients often encounter paresthesia or discomfort before progressing to muscle weakness, initially in the lower extremities (which may include some proximal components) and subsequently in the upper extremities...

We investigated the effect of gallic acid against neurodegenerative pathophysiology relevant to PD in mice with rotenone-induced toxicity. Forty male ICR mice were randomly divided into four groups: sham-veh, PD-veh (received subcutaneous injection with 2.5 mg/kg/48 h of rotenone); PD-Gal50; and PD-Gal100 (the latter two groups received subcutaneous injection with 2.5 mg/kg/48 h of rotenone and oral gavage with gallic acid 50 and 100 mg/kg/48 h, respectively). All treatments continued for 5 weeks with motor ability assessments once per week using hanging and rotarod tests...