Atomically precise photothermal nanomachines.

Interfacing molecular machines to inorganic nanoparticles can, in principle, lead to hybrid nanomachines with extended functions. Here we demonstrate a ligand engineering approach to develop atomically precise hybrid nanomachines by interfacing gold nanoclusters with tetraphenylethylene molecular rotors. When gold nanoclusters are irradiated with near-infrared light, the rotation of surface-decorated tetraphenylethylene moieties actively dissipates the absorbed energy to sustain the photothermal nanomachine with an intact structure and steady efficiency. Solid-state nuclear magnetic resonance and femtosecond transient absorption spectroscopy reveal that the photogenerated hot electrons are rapidly cooled down within picoseconds via electron-phonon coupling in the nanomachine. We find that the nanomachine remains structurally and functionally intact in mammalian cells and in vivo. A single dose of near-infrared irradiation can effectively ablate tumours without recurrence in tumour-bearing mice, which shows promise in the development of nanomachine-based theranostics.

Functional Characteristics, Electrophysiological and Antennal Immunolocalization of General Odorant-Binding Protein 2 in Tea Geometrid, Ectropis obliqua.

As one of the main lepidopteran pests in Chinese tea plantations, Ectropisobliqua Warren (tea geometrids) can severely decrease yields of tea products. The olfactory system of the adult tea geometrid plays a significant role in seeking behaviors, influencing their search for food, mating partners, and even spawning grounds. In this study, a general odorant-binding protein (OBP) gene, EoblGOBP2, was identified in the antennae of E. obliqua using reverse transcription quantification PCR (RT-qPCR). Results showed that EoblGOBP2 was more highly expressed in the antennae of males than in females relative to other tissues. The recombinant EoblGOBP2 protein was prepared in Escherichia coli and then purified through affinity chromatography. Ligand-binding assays showed that EoblGOBP2 had a strong binding affinity for some carbonyl-containing tea leaf volatiles (e.g., (E)-2-hexenal, methyl salicylate, and acetophenone). Electrophysiological tests confirmed that the male moths were more sensitive to these candidate tea plant volatiles than the female moths. Immunolocalization results indicated that EoblGOBP2 was regionally confined to the sensilla trichoid type-II in the male antennae. These results indicate that EoblGOBP2 may be primarily involved in the olfactory activity of male E. obliqua moths, influencing their ability to sense tea leaf volatiles. This study provides a new perspective of insect GOBPs and implies that olfactory function can be used to prevent and control the tea geometrid.

Protective effects of luteolin on cognitive impairments induced by psychological stress in mice.

In the present study, the protective effects of luteolin were investigated against psychological stress-induced cognitive impairment. To emulate the psychological stress, mice received restraint stress for six hours daily, between 9:00 and 15:00 hours, for 21 consecutive days. The results of step-through test, open-field test and Morris Water Maze test demonstrated that psychological stress treatment could result in cognitive impairments in mice. This cognition dysfunction was improved by treatment with low- and medium-dose luteolin. In addition, psychological stress induced an increased serum corticosterone concentration with a decreased serum norepinephrine and dopamine concentration. These alterations were attenuated by treatment with luteolin. Also, psychological stress significantly decreased the glutathione (GSH) concentrations and superoxide dismutase (SOD) activities in prefrontal cortex and hippocampus, while the malondialdehyde (MDA) concentrations were enhanced. However, these oxidative alterations in prefrontal cortex and hippocampus induced by psychological stress were significantly reversed by treatment of luteolin. Further, the current study indicated a decline of catalase (CAT) activities in the hippocampus of the ST group, which was significantly prevented by low, medium and high dose of luteolin. On the other hand, there was no significance in CAT activities of the prefrontal cortex among the six groups. Collectively, the present results suggest that luteolin treatment serves as a key role in improving the psychological stress-induced cognitive impairments.

L-citrulline protects against glycerol-induced acute renal failure in rats.

There is an increasing evidence that oxidative stress plays an important role in the pathogenesis of rhabdomyolysis-induced acute renal failure (ARF). In this study, protective effects of L-citrulline on glycerol-induced ARF in rats were investigated. Six groups of rats were employed in this study: group 1 served as a control; group 2 was only given glycerol (50%, 10 mL/kg, i.m.); group 3 was given glycerol plus dexamethasone (0.1 mg/kg, i.g.) as positive reference drug, starting at the same time as the glycerol injections; the last three groups were given glycerol plus L-citrulline (300, 600, and 900 mg/kg, i.g.) respectively, starting at the same time as the glycerol injections. The injections of glycerol were only once, and after glycerol injections the i.g. administrations of dexamethasone and L-citrulline were repeated every 24 h for 7 days. After 7 days of glycerol injections, the blood samples and kidney tissues were harvested for future biochemical and pathology analyses. The levels of creatinine (Cr) and urea nitrogen (BUN) in plasma, the content of malondialdehyde (MDA), glutathione (GSH), nitric oxide (NO), the activity of total nitric oxide synthase (TNOS), inducible nitric oxide synthase (iNOS), endothelial NO synthase (eNOS), and superoxide dismutase (SOD) were evaluated in kidney tissues. Consequently, administrations of L-citrulline improved an impaired intrarenal oxygenation and kidney function compared with the glycerol group, and prevented the renal oxidative stress damage as well as severe functional and morphological renal deterioration. Therefore, L-citrulline might have potential application in the amelioration of glycerol-induced ARF.

Antidepressant-like effects of tea polyphenols on mouse model of chronic unpredictable mild stress.

Tea polyphenols (TPs), which are the natural compounds extracted from tea leaves, possess a number of beneficial properties, such as reducing the risks of cancer and heart diseases, alleviating cognitive impairments and showing antidepressant-like activity in the forced swim test (FST) and tail suspension test (TST). The present study was designed to investigate the protective effect of TPs on the chronic unpredictable mild stress (CUMS)-induced depression model in mice and to elucidate the related underlying mechanisms. With the daily exposure to stressor for 5 consecutive weeks, TPs were administered in mice at a daily dose of 25 mg/kg or 50 mg/kg by gavage for 3 consecutive weeks from the 3rd week. Our results showed that CUMS significantly decreased the levels of serum serotonin (5-HT) and norepinephrine (NE) in the hippocampus, the prefrontal cortex and serum, and the activities of superoxide dismutase (SOD) and catalase (CAT), with an increase in lipid peroxidation level as well as a reduction in glutathione (GSH) level and an elevation in the production of malondialdehyde (MDA) in the hippocampus and the prefrontal cortex. CUMS also reduced open-field activity, sucrose consumption, as well as increased immobility duration in FST and TST. TPs administration could effectively reverse the alterations in the concentrations of 5-HT and NE, elevate the activities of SOD and CAT as well as the level of GSH, reduce the MDA level and inhibit lipid peroxidation. Moreover, TPs could effectively reverse alterations in immobility duration, sucrose consumption and open-field activity. In conclusion, TPs administration has exhibited significant antidepressant-like effects in mice with CUMS-induced depression. The antidepressant activity of TPs might be related to the alteration of monoaminergic responses and antioxidant defenses.