Ultrasonic Control of Polymer-Capped Plasmonic Molecules.

Plasmonic molecules (PMs) composed of polymer-capped nanoparticles represent an emerging material class with precise optical functionalities. However, achieving controlled structural changes in metallic nanoparticle aggregation at the nanoscale, similar to the modification of atomic structures, remains challenging. This study demonstrates the 2D/3D isomerization of such plasmonic molecules induced by a controlled ultrasound process.

Quantifying the contributions of meteorology, emissions, and transport to ground-level ozone in the Pearl River Delta, China.

Ozone pollution presents a growing air quality threat in urban agglomerations in China. It remains challenge to distinguish the roles of emissions of precursors, chemical production and transportations in shaping the ground-level ozone trends, largely due to complicated interactions among these 3 major processes. This study elucidates the formation factors of ozone pollution and categorizes them into local emissions (anthropogenic and biogenic emissions), transport (precursor transport and direct transport from various regions), and meteorology.

Sources, size-resolved deposition in the human respiratory tract and health risks of submicron black carbon in urban atmosphere in Pearl River Delta, China.

Black carbon (BC) has a significantly negative impact on air quality, climate and human health. Here we investigated the sources and health effects of BC in urban area of the Pearl River Delta (PRD) based on online data measured by Aerodyne soot particle high-resolution time of flight aerosol mass spectrometer (SP-AMS). In urban PRD, BC particles mainly came from vehicle emissions especially heavy-duty vehicle exhausts (contributing 42.

[Compositional Characteristics of Volatile Organic Compounds in Typical Industrial Areas of the Pearl River Delta: Importance of Oxygenated Volatile Organic Compounds].

Volatile organic compounds (VOCs) are key components of tropospheric chemistry, of which industrial emissions are an important source of atmospheric VOCs. In this study, online measurements of 74 VOCs were made in a typical industrial area of the Pearl River Delta in southern China during the early summer of 2021. The mean volume mixing ratio of total volatile organic compounds (TVOC) was (81.

Photolysis frequency of nitrophenols derived from ambient measurements.

Nitrophenols, a class of important intermediate products from the oxidation of aromatics, can participate in photochemistry and influence the atmospheric oxidative capacity. However, the reported photolysis frequencies of nitrophenols show considerable discrepancies. Here, measurements of nitrophenol, and methyl nitrophenol using a proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS) at both urban and regional sites in southern China are used to constrain photolysis frequencies of nitrophenols.

Inter-comparisons of VOC oxidation mechanisms based on box model: A focus on OH reactivity.

Volatile organic compounds (VOCs) oxidation processes play a very important role in atmospheric chemistry, and the chemical reactions are expressed in various manners in chemical mechanisms. To gain an improved understanding of VOCs evolution during oxidation processes and evaluate the discrepancies of VOCs oxidation schemes among different mechanisms, we used the total VOC reactivity as a diagnostic and evaluated tool to explore the differences for six widely used chemical mechanisms. We compared the total VOC reactivity evolution under high-NO conditions for several sets of precursors, including n-pentane, toluene, ethene, isoprene and a mixture of 57 Photochemical Assessment Monitoring Stations (PAMS) species in a 0-D photochemical box model.

Quantifying the role of PM dropping in variations of ground-level ozone: Inter-comparison between Beijing and Los Angeles.

In recent decade the ambient fine particle (PM) levels have shown a trend of distinct dropping in China, while ground-level ozone concentrations have been increasing in Beijing and many other Chinese mega-cities. The variation pattern in Los Angeles was markedly different, with PM and ozone decreasing together over past decades. In this study, we utilize observation-based methods to establish the parametric relationship between PM concentration and key aerosol physical properties (including aerosol optical depth and aerosol surface concentration), and an observation-based 1-D photochemical model to quantify the response of PM decline in enhancing ground-level ozone pollution over a large PM concentration range (10-120 μg m).

High Concentrations of Atmospheric Isocyanic Acid (HNCO) Produced from Secondary Sources in China.

Isocyanic acid (HNCO) is a potentially toxic atmospheric pollutant, whose atmospheric concentrations are hypothesized to be linked to adverse health effects. An earlier model study estimated that concentrations of isocyanic acid in China are highest around the world. However, measurements of isocyanic acid in ambient air have not been available in China.

Splenocytes derived from young WT mice prevent AD progression in APPswe/PSENldE9 transgenic mice.

Immunosenescence contributes to pathogenesis of Alzheimer's disease (AD) in the elderly. In this study, we explored the effects of young wild type (WT) splenocytes (ySCs) on Alzheimer's disease by transplanting ySCs into APPswe/PSENldE9 transgenic mice. Young WT splenocytes not only prevented AD, but also improved the spatial learning and memory of APPswe/PSENldE9 transgenic mice.

Combined treatment of amyloid-β₁₋₄₂-stimulated bone marrow-derived dendritic cells plus splenocytes from young mice prevents the development of Alzheimer's disease in APPswe/PSENldE9 mice.

Anti-amyloid-β (Aβ) immunotherapy is a potential therapeutic strategy to reduce amyloid plaques and amyloid-associated pathologies in Alzheimer's disease (AD). Immune senescence with aging has also played a crucial role in AD pathogenesis and influences the effect of anti-Aβ immunotherapy. In this study, a combined treatment of Aβ₁₋₄₂-bone marrow-derived dendritic cells (BMDCs) with intraperitoneal injection of splenocytes from young mice was designed as a novel immunotherapy for AD in APPswe/PSEN1de9 transgenic mice models.

Changes in Otx2 and parvalbumin immunoreactivity in the superior colliculus in the platelet-derived growth factor receptor-β knockout mice.

The superior colliculus (SC), a relay nucleus in the subcortical visual pathways, is implicated in socioemotional behaviors. Homeoprotein Otx2 and β subunit of receptors of platelet-derived growth factor (PDGFR- β ) have been suggested to play an important role in development of the visual system and development and maturation of GABAergic neurons. Although PDGFR- β -knockout (KO) mice displayed socio-emotional deficits associated with parvalbumin (PV-)immunoreactive (IR) neurons, their anatomical bases in the SC were unknown.

Neuregulin1beta1 antagonizes apoptosis via ErbB4-dependent activation of PI3-kinase/Akt in APP/PS1 transgenic mice.

Alzheimer's disease (AD) is characterized by the deposition of beta-amyloid protein (Aβ) and extensive neuronal cell death. Apoptosis plays a crucial role in loss of neurons in AD. Neuregulin1 (NRG1) has been found to protect neurons from oxygen glucose deprivation induced apoptosis and hypoxia ischemia induced apoptosis.

Transplantation of oligodendrocyte precursor cells improves locomotion deficits in rats with spinal cord irradiation injury.

Demyelination contributes to the functional impairment of irradiation injured spinal cord. One potential therapeutic strategy involves replacing the myelin-forming cells. Here, we asked whether transplantation of Olig2(+)-GFP(+)-oligodendrocyte precursor cells (OPCs), which are derived from Olig2-GFP-mouse embryonic stem cells (mESCs), could enhance remyelination and functional recovery after spinal cord irradiation injury.

Downregulating the canonical Wnt/β-catenin signaling pathway attenuates the susceptibility to autism-like phenotypes by decreasing oxidative stress.

Although a growing body of evidence supports the importance of the Wnt/β-catenin signaling pathway and oxidative stress in the pathogenesis of autism, it is unclear whether a relationship exists between the Wnt/β-catenin pathway and oxidative homeostasis. The present study examines the effects of sulindac, a small molecule inhibitor of the Wnt/β-catenin signaling pathway, on the oxidative status of rats that are prenatally exposed to valproic acid (VPA), which is used in an animal model of autism. Our data show that sulindac treatment downregulated the canonical Wnt/β-catenin signaling pathway by enhancing the expression of Glycogen Synthase Kinase 3β and attenuating the expression of β-catenin in comparison to levels in VPA-treated rats.

Expression of glial cell line-derived neurotrophic factor and its receptors in cultured retinal Müller cells under high glucose circumstance.

This study aimed to explore the effect of high glucose concentration on the expression of glial cell line-derived neurotrophic factor (GDNF) and its family ligand receptors (GFRs) GFRα1 and GFRα2 in Müller cells and the protective role of GDNF in cultured Müller cells under high glucose circumstance. Cultured Müller cells (untreated or treated with 200 ng/mL of GDNF) were exposed to high glucose conditions (20 mmol/L glucose). We found that the expression levels of GDNF and GFRα1 mRNA and protein increased gradually over time under high glucose and exogenous GDNF-treated conditions, whereas the upregulation in GFRα2 expression was observed only in the early stage of high glucose conditions.

Activation of liver X receptor decreases BACE1 expression and activity by reducing membrane cholesterol levels.

The synthetic Liver X receptor (LXR) activator T0901317 has been reported to exert neuroprotective effect in Alzheimer's disease, but the relationship between LXR activation and beta-site amyloid precursor protein cleaving enzyme 1 (BACE-1) remains uncertain. This study investigated the effect of T0901317 on membrane cholesterol levels, BACE1 expression and activity. We found that T0901317 decreased membrane cholesterol levels, reduced BACE1 expression and activity as well as β-secretase cleaved C-terminal fragment (β-CTF) levels in vivo and in vitro.

MK-801 induces schizophrenic behaviors through downregulating Wnt signaling pathways in male mice.

Wnt signaling is important in various neuropsychiatric diseases. However, its actions on modulating schizophrenia are largely unknown. Our previous study found that three SNPs in adenomatous polyposis coli (APC), a negative regulator of the Wnt signaling, were associated with schizophrenia, and the mRNA levels of APC in blood leucocytes of patients with schizophrenia were significantly increased.

Alterations of NMDA receptor subunits NR1, NR2A and NR2B mRNA expression and their relationship to apoptosis following transient forebrain ischemia.

Glutamate excitotoxicity mediated by NMDA receptor activation plays a key role in many aspects of ischemic brain injury, but the expression of NMDA receptor subunits NR1, NR2A and NR2B mRNA and their relationship to apoptosis is still unclear. In this study, we applied in situ hybridization and TUNEL staining to investigate the expression of NMDA receptor subunit mRNA and apoptosis in hippocampus of rats after transient forebrain ischemia. The results showed that in the CA1 region, NR1 mRNA expression was significantly increased following ischemia-reperfusion (IR), reaching peak levels at IR 24h, and then gradually decreasing until IR 7 days.

Demethylation of specific Wnt/β-catenin pathway genes and its upregulation in rat brain induced by prenatal valproate exposure.

Valproate (VPA) has been used for decades in the treatment of epilepsy and migraine. However, maternal administration of VPA during pregnancy increases susceptibility to autism spectrum disorders (ASDs) in the offspring. The aim of this study was to investigate the methylation modification and its effects on the activity of Wnt/β-catenin pathway in the rat brain prenatally exposed to VPA.

(Z)-(1,3-Thia-zinan-2-ylideneamino)formo-nitrile.

In the title mol-ecule, C(5)H(7)N(3)S, the thia-zine ring shows a conformation close to a half-boat. The Cremer & Pople puckering parameters of the thia-zine ring are q2 = 0.4645 (2) Å, θ = 132.

Neuroprotective effects of neuregulin-1 in rat models of focal cerebral ischemia.

The purpose of this study was to investigate the therapeutic efficacy and mechanism of recombinant human NRG-1 to attenuate ischemia/reperfusion brain injury. NRG-1(3.0 ng/kg) was applied intravascularly 10 min before middle cerebral artery occlusion (MCAO) and then focal cerebral ischemia for 90 min and reperfusion for 24 h.