Prefrontal activity and heart rate variability during cognitive tasks may show different changes in young and older adults with and without mild cognitive impairment.

Background: Age-related decline in cognitive function is often linked to changed prefrontal cortex (PFC) activity and heart rate variability (HRV). Mild cognitive impairment (MCI), a transitional stage between normal aging and dementia, might have further degeneration beyond aging. This study aimed to investigate the differences between young and older adults with or without MCI in cognitive functions, task-induced PFC activation and HRV changes. Methods: Thirty-one healthy young adults (YA), 44 older adults (OA), and 28 older adults with MCI (OA-MCI) were enrolled and compared in this cross-sectional study. Each participant received a one-time assessment including cognitive and executive functions, as well as the simultaneous recording of PFC activity and HRV during a cognitive task paradigm. Results: We observed age-related decrease in global cognitive functions, executive functions, HRV, and increase in PFC activity. The MCI further deteriorated the global cognitive and executive performances, but not the HRV or the prefrontal activation. Conclusion: Older people showed lower performances in general cognitive function and executive function, compensatory increase of PFC activity, and reduced HRV. Older people with MCI had further deterioration in cognitive performance, but not in PFC activation and HRV.

Changes in α-Dicarbonyl Compound Contents during Storage of Various Fruits and Juices.

α-Dicarbonyl compounds (α-DCs) are commonly present in various foods. We conducted the investigation into concentration changes of α-DCs including 3-deoxyglucosone (3-DG), glyoxal (GO), and methylglyoxal (MGO) in fresh fruits and decapped commercial juices during storage at room temperature and 4 °C, as well as in homemade juices during storage at 4 °C. The studies indicate the presence of α-DCs in all samples. The initial contents of 3-DG in the commercial juices (6.74 to 65.61 µg/mL) are higher than those in the homemade ones (1.97 to 4.65 µg/mL) as well as fruits (1.58 to 3.33 µg/g). The initial concentrations of GO and MGO are normally less than 1 µg/mL in all samples. During storage, the α-DC levels in the fruits exhibit an initial increase followed by a subsequent decrease, whereas, in all juices, they tend to accumulate continuously over time. As expected, 4 °C storage reduces the increase rates of the α-DC concentrations in most samples. From the viewpoint of the α-DC contents, fruits and homemade juices should always be the first choice for daily intake of nutrients and commercial juices ought to be mostly avoided.

On-Demand Storage of Photonic Qubits at Telecom Wavelengths.

Quantum memories at telecom wavelengths are crucial for the construction of large-scale quantum networks based on existing fiber networks. On-demand storage of telecom photonic qubits is an essential request for such networking applications but yet to be demonstrated. Here we demonstrate the storage and on-demand retrieval of telecom photonic qubits using a laser-written waveguide fabricated in an ^{167}Er^{3+}:Y_{2}SiO_{5} crystal. Both ends of the waveguide memory are directly connected with fiber arrays with a fiber-to-fiber efficiency of 51%. Storage fidelity of 98.3(1)% can be obtained for time-bin qubits encoded with single-photon-level coherent pulses, which is far beyond the maximal fidelity that can be achieved with a classical measure and prepared strategy. This device features high reliability and easy scalability, and it can be directly integrated into fiber networks, which could play an essential role in fiber-based quantum networks.

Aquaporin-4 deletion attenuates opioid-induced addictive behaviours associated with dopamine levels in nucleus accumbens.

There is a lack of safe and effective non-opioid medications for the treatment of opioid addiction. Aquaporin-4 (AQP4), a water channel protein expressed in astrocytes, regulates the progression of neurological diseases. Our previous work demonstrated that AQP4 deficiency in mice attenuated morphine-induced physiological dependence. However, the role of AQP4 in the neurobiology of behaviours related to opioid addiction in mice remains unclear. Here, we report that Aqp4-knockout mice exhibited attenuated heroin consumption and heroin-seeking behaviours. Furthermore, Aqp4-knockout mice displayed diminished hyperactivity induced by morphine and heroin and subsequently showed dramatically inhibited morphine-induced behavioural sensitization. This attenuated hyperlocomotion to opioids was accompanied by a decreased dopamine response to the opioid-induced increase in the levels of extracellular dopamine in the NAc. In addition, Aqp4-knockout mice displayed upregulation of dopamine transporters in the striatum, suggesting a probable neurobiological mechanism for uptake of the extracellular dopamine. The present findings suggest that deficiency of AQP4 decreases opiate-induced drug seeking and taking behaviours, and AQP4 may be involved in the treatment of addiction. Therefore, the development of a pharmacological antagonist to AQP4 may be valuable to investigate as opioid addiction therapy.

Heralded entanglement distribution between two absorptive quantum memories.

Owing to the inevitable loss in communication channels, the distance of entanglement distribution is limited to approximately 100 kilometres on the ground1. Quantum repeaters can circumvent this problem by using quantum memory and entanglement swapping2. As the elementary link of a quantum repeater, the heralded distribution of two-party entanglement between two remote nodes has only been realized with built-in-type quantum memories3-9. These schemes suffer from the trade-off between multiplexing capacity and deterministic properties and hence hinder the development of efficient quantum repeaters. Quantum repeaters based on absorptive quantum memories can overcome such limitations because they separate the quantum memories and the quantum light sources. Here we present an experimental demonstration of heralded entanglement between absorptive quantum memories. We build two nodes separated by 3.5 metres, each containing a polarization-entangled photon-pair source and a solid-state quantum memory with bandwidth up to 1 gigahertz. A joint Bell-state measurement in the middle station heralds the successful distribution of maximally entangled states between the two quantum memories with a fidelity of 80.4 ± 2.2 per cent (±1 standard deviation). The quantum nodes and channels demonstrated here can serve as an elementary link of a quantum repeater. Moreover, the wideband absorptive quantum memories used in the nodes are compatible with deterministic entanglement sources and can simultaneously support multiplexing, which paves the way for the construction of practical solid-state quantum repeaters and high-speed quantum networks.

Storage of telecom-C-band heralded single photons with orbital-angular-momentum encoding in a crystal.

A memory-based quantum repeater architecture provides a solution to distribute quantum information to an arbitrary long distance. Practical quantum repeaters are likely to be built in optical-fiber networks which take advantage of the low-loss transmission between quantum memory nodes. Most quantum memory platforms have characteristic atomic transitions away from the telecommunication band. A nondegenerate photon pair source is therefore useful for connection of a quantum memory to optical fibers. Here, we report a high-brightness narrowband photon-pair source which is compatible with a rare-earth-ion-doped crystal Pr3+:Y2SiO5. The photon-pair source is generated through a cavity-enhanced spontaneous parametric down-conversion process with the signal photon at 606 nm and the idler photon at 1540 nm. Moreover, using the telecom C-band idler photons for heralding, we demonstrate the reversible transfer of orbital-angular-momentum qubit between the signal photon and the quantum memory based on Pr3+:Y2SiO5.

Multiplexed storage and real-time manipulation based on a multiple degree-of-freedom quantum memory.

The faithful storage and coherent manipulation of quantum states with matter-systems would enable the realization of large-scale quantum networks based on quantum repeaters. To achieve useful communication rates, highly multimode quantum memories are required to construct a multiplexed quantum repeater. Here, we present a demonstration of on-demand storage of orbital-angular-momentum states with weak coherent pulses at the single-photon-level in a rare-earth-ion-doped crystal. Through the combination of this spatial degree-of-freedom (DOF) with temporal and spectral degrees of freedom, we create a multiple-DOF memory with high multimode capacity. This device can serve as a quantum mode converter with high fidelity, which is a fundamental requirement for the construction of a multiplexed quantum repeater. This device further enables essentially arbitrary spectral and temporal manipulations of spatial-qutrit-encoded photonic pulses in real time. Therefore, the developed quantum memory can serve as a building block for scalable photonic quantum information processing architectures.

Identification of functional nuclear export sequences in human sphingosine kinase 1.

Sphingosine kinase (SPHK) is an enzyme that phosphorylates sphingosine to form sphingosine 1-phosphate (S1P). Human SPHK1 (hSPHK1) was localized predominantly in the cytoplasm when transiently expressed in Cos7 cells. In this study, we have found two functional nuclear export signal (NES) sequences in the middle region of hSPHK1. Deletion and mutagenesis studies revealed that the cytoplasmic localization of SPHK1 depends on its nuclear export, directed by the NES. Furthermore, upon treatment with leptomycin B, a specific inhibitor of the nuclear export receptor CRM1, a marked nuclear accumulation of hSPHK1 was observed, indicating that hSPHK1 shuttles between the cytoplasm and the nucleus. Our results provide the first evidence of the active nuclear export of SPHK1 and suggest it is mediated by a CRM1-dependent pathway.

Influence of platelet activating factor on expression of adhesion molecules in experimental pancreatitis.

AIM: To determine whether Platelet activating factor (PAF) has a regulation role in the expression of adhesion molecules and accumulation of neutrophils in a murine model of acute pancreatitis. METHODS: One hundred twenty-eight Kunming mice were divided into four groups. Group 1 received 0.1 ml saline s.c. every hour for three hours (sham). Group 2 received cerulein (50 microg/kg dose s.c.) every hour for three hours. Group 3 received AP and additional challenge of PAF (50 mg/kg in absolute ethanol) (AP/PAF). Group 4 received AP, plus therapeutic treatment with GAB (25 mg dose i.p.) immediately after the first challenge of cerulein (AP/GAB). Animals were sacrificed at 12 h after the first challenge of saline or cerulein. Adhesion molecules of pancreas were semi-quantified by SP methods. Standard assays were performed for serum amylase and myeloperoxidase activity (MPO) of pancreas. Histology of pancreas was scored in a blind manner. Water content of pancreas was also measured at the same time. RESULTS: Control pancreata showed negligible adhesion molecule expression and neutrophil accumulation. There were evident adhesion molecules expression and neutrophil accumulation in AP and AP/PAF compared with sham (P<0.05). AP/GAB had a lower level of adhesion molecules, neutrophils, and water content versus AP and AP/PAF (P<0.05). Histology showed a trend toward improvement in AP/GAB, but did not reach statistical significance. CONCLUSION: PAF can induce the expression of adhesion molecules that mediate neutrophil accumulation. The PAF antagonist reduces the expression of adhesion molecules and the severity of inflammation when given immediately after the induction of mild AP in mice. These results suggest that PAF antagonism may be useful in the treatment of mild pancreatitis after its clinical onset.