Topological Atomic Spinwave Lattices by Dissipative Couplings

Recent experimental advance in creating dissipative couplings provides a new route for engineering exotic lattice systems and exploring topological dissipation. Using the spatial lattice of atomic spinwaves in a vacuum vapor cell, where purely dissipative couplings arise from diffusion of atoms, we experimentally realize a dissipative version of the Su-Schrieffer-Heeger (SSH) model. We construct the dissipation spectra of the topological or trivial lattices via electromagnetically-induced-transparency (EIT) spectroscopy. The topological dissipation spectrum is found to exhibit edge modes at dissipation rates within a dissipative gap, decoupled from the bulk. We also validate chiral symmetry of the dissipative SSH couplings. This work paves the way for realizing topology-enabled quantum correlations and non-Hermitian topological quantum optics via dissipative couplings.Comment: 5 pages, 4 figure

Experimental study on the repair of peripheral nerve injuries via simultaneously coapting the proximal and distal ends of peripheral nerves to the side of nearby intact nerves

IntroductionPeripheral nerve defect is a difficult disease to treat in clinical practice. End-to-side anastomosis is a useful method to treat it. At present, the end-to-side anastomosis method does not involve the proximal nerve, which results in a waste of proximal donor nerves, and even the formation of traumatic neuromas at the proximal end. The patients suffer from traumatic neuralgia and the curative effect is unsatisfactory.MethodsIn this study, an improved end-to-side anastomosis technique was proposed in this study: both the proximal and distal ends of the damaged common peroneal nerve were sutured to an adjacent normal tibial nerve. Moreover, the possible role and mechanism of the proposed technique were explained at the physiological and anatomical levels. In this study, a 10 mm common peroneal nerve defect was made in SD rats, and the rats were randomly divided into three groups. In Group I, the distal end of the common peroneal nerve was attached end-to-side to the fenestrated tibial nerve adventitia, and the proximal end was ligated and fixed in the nearby muscle. In Group II, the tibial nerve adventitia was fenestrated and the epineurial end-to-end anastomosis surgery was performed to suture the proximal and distal ends of the common peroneal nerve. Rats in Group III were taken as control and received sham operation. Twelve weeks after the operation, the recovery of the repaired nerve and distal effector functions were examined by the sciatic functional index, electrophysiology, osmic acid staining, the muscle wet weight ratio, and the muscle fiber cross-sectional area.ResultsIt was found that these results in Group II were similar to those in Group III, but better than those in Group I. Through retrograde tracing of neurons and Electrophysiological examination in Group II, the study also found that the proximal common peroneal nerve also could establish a connection with tibialis anterior, even gastrocnemius.DiscussionTherefore, it is inferred that fostering both the proximal and distal ends of defective peripheral nerves on normal peripheral nerves using the end-to-side anastomosis technique is a more effective approach to repairing injured nerves

Application fruit tree hole storage brick fertilizer is beneficial to increase the nitrogen utilization of grape under subsurface drip irrigation

It is very important to promote plant growth and decrease the nitrogen leaching in soil, to improve nitrogen (N) utilization efficiency. In this experiment, we designed a new fertilization strategy, fruit tree hole storage brick (FTHSB) application under subsurface drip irrigation, to characterise the effects of FTHSB addition on N absorption and utilization in grapes. Three treatments were set in this study, including subsurface drip irrigation (CK) control, fruit tree hole storage brick A (T1) treatment, and fruit tree hole storage brick B (T2) treatment. Results showed that the pore number and size of FTHSB A were significantly higher than FTHSB B. Compared with CK, T1 and T2 treatments significantly increased the biomass of different organs of grape, N utilization and 15N content in the roots, stems and leaves, along with more prominent promotion at T1 treatment. When the soil depth was 15–30 cm, the FTHSB application significantly increased the soil 15N content. But when the soil depth was 30–45 cm, it reduced the soil 15N content greatly. T1 and T2 treatments obviously increased the activities of nitrite reductase (NR) and glutamine synthetase (GS) in grape leaves, also the urease activity(UR) in 30 cm of soil. Our findings suggest that FTHSB promoted plant N utilization by reducing N loss in soil and increasing the enzyme activity related to nitrogen metabolism. In addition, this study showed that FTHSB A application was more effective than FTHSB B in improving nitrogen utilization in grapes

Study of GABA in Healthy Volunteers: Pharmacokinetics and Pharmacodynamics

Preclinical studies show that GABA exerts anti-diabetic effects in rodent models of type 1 diabetes. Because little is known about its absorption and effects in humans, we investigated the pharmacokinetics and pharmacodynamics of GABA in healthy volunteers. Twelve subjects were subjected to an open-labeled, three-period trial involving sequential oral administration of placebo, 2 g GABA once, and 2 g GABA three times/day for 7 days, with a 7-day washout between each period. GABA was rapidly absorbed (Tmax: 0.5 ~ 1 h) with the half-life (t1/2) of 5 h. No accumulation was observed after repeated oral GABA administration for 7 days. Remarkably, GABA significantly increased circulating insulin levels in the subjects under either fasting (1.6-fold, single dose; 2.0-fold, repeated dose; p \u3c 0.01) or fed conditions (1.4-fold, single dose; 1.6-fold, repeated dose; p \u3c 0.01). GABA also increased glucagon levels only under fasting conditions (1.3-fold, single dose, p \u3c 0.05; 1.5-fold, repeated dose, p \u3c 0.01). However, there were no significant differences in the insulin-to-glucagon ratio and no significant change in glucose levels in these healthy subjects during the study period. Importantly, GABA significantly decreased glycated albumin levels in the repeated dosing period. Subjects with repeated dosing showed an elevated incidence of minor adverse events in comparison to placebo or the single dosing period, most notably transient discomforts such as dizziness and sore throat. However, there were no serious adverse events observed throughout the study. Our data show that GABA is rapidly absorbed and tolerated in human beings; its endocrine effects, exemplified by increasing islet hormonal secretion, suggest potential therapeutic benefits for diabetes

Flexible Dye-Sensitized Solar Cell Based on Vertical ZnO Nanowire Arrays

Flexible dye-sensitized solar cells are fabricated using vertically aligned ZnO nanowire arrays that are transferred onto ITO-coated poly(ethylene terephthalate) substrates using a simple peel-off process. The solar cells demonstrate an energy conversion efficiency of 0.44% with good bending tolerance. This technique paves a new route for building large-scale cost-effective flexible photovoltaic and optoelectronic devices

Experimental study on LBL beams

Six specimens were made and tested to study the mechanical properties of LBL beams. The mean ultimate loading value is 68.39 MPa with a standard deviation of 6.37 MPa, giving a characteristic strength (expected to be exceeded by 95% of specimens) of 57.91 MPa, and the mean ultimate deflection is 53.3 mm with a standard deviation of 5.5 mm, giving the characteristic elastic modulus of 44.3 mm. The mean ultimate bending moment is 20.18 kN.m with a standard deviation of 1.88 kN.m, giving the characteristic elastic modulus of 17.08 kN.m. The mean elastic modulus is 9688 MPa with a standard deviation of 1765 MPa, giving the characteristic elastic modulus of 6785 MPa, and the mean modulus of rupture is 93.3 MPa with a standard deviation of 8.6 MPa, giving the characteristic elastic modulus of 79.2 MPa. The strain across the cross-section for all LBL beams is basically linear throughout the loading process, following standard beam theory