Aharonov-Bohm effect in monolayer black phosphorus (phosphorene) nanorings

This work presents theoretical demonstration of Aharonov-Bohm (AB) effect in monolayer phosphorene nanorings (PNR). Atomistic quantum transport simulations of PNR are employed to investigate the impact of multiple modulation sources on the sample conductance. In presence of a perpendicular magnetic field, we find that the conductance of both armchair and zigzag PNR oscillate periodically in a low-energy window as a manifestation of the AB effect. Our numerical results have revealed a giant magnetoresistance (MR) in zigzag PNR (with a maximum magnitude approaching two thousand percent). It is attributed to the AB effect induced destructive interference phase in a wide energy range below the bottom of the second subband. We also demonstrate that PNR conductance is highly anisotropic, offering an additional way to modulate MR. The giant MR in PNR is maintained at room temperature in the presence of thermal broadening effect.Comment: 7 pages, 7 figure

Electric-field switching of exciton spin splitting in coupled quantum dots

We investigate theoretically the spin splitting of the exciton states in semiconductor coupled quantum dots (CQDs) containing a single magnetic ion. We find that the spin splitting can be switched on/off in the CQDs \textit{via} the \textit{sp-d}exchange interaction using the electric field. An interesting bright-to-dark exciton transition can be found and significantly affects the photoluminescence spectrum. This phenonmenon is induced by the transition of the ground exciton state, arising from the hole mixing effect, between the bonding and antibonding states.Comment: 3 pages, 5 figures. to appear in Appl. Phys. Let

The Law Analysis of the Weihe River Basin (Shaanxi Section) Precipitation

Abstract: Based on 1956-2010 of precipitation of Weihe river basin in shanxi section, this paper statistical analysis the precipitation characteristics, the cycle, the abrupt, the trend and sustainable. The results show that the average of many years is 606.63 mm, the maximum is 931.86 in 2003, the minimum is 368.56 in 1995; the precipitation is more in 20 century 50, 60 and 80s, less in 70, 90s and the 2000s and the average of precipitation is close to average of many years in 70s and 2000s; The rainfall process has the remarkable periodic, the first main cycle for 18 years, the second cycle for 7 years, the third for three years; The average rainfall not happened obviously mutations; and the precipitation is not significant decrease trend; Hurst index greater than 0.5, which suggests that past trends of precipitation will be continue in the future, namely in the future precipitation is not significant digressive tendency. The conclusions have the important reference value to weigh river water resources development

Increased expression of Psoriasin is correlated with poor prognosis of bladder transitional cell carcinoma by promoting invasion and proliferation

Psoriasin, otherwise known as S100A7, is a member of the S100 protein family. With the key function of binding calcium, it is able to regulate a range of cellular functions. Altered Psoriasin expression is associated with poor clinical outcomes in several solid cancers. The present study aimed to examine the implication of Psoriasin in bladder cancer (BC). Expression of Psoriasin was examined in BC cell lines using PCR. Immunohistochemical (IHC) staining of Psoriasin was performed on a bladder disease spectrum tissue array. Plasmids were constructed to effectively knockdown and overexpress Psoriasin in BC cells and further utilized for in vitro BC cellular function assays. Association between Psoriasin expression and survival of patients with BC was evaluated using Kaplan‑Meier survival analysis. Psoriasin was revealed to be expressed by both bladder epithelia and cancer cells as determined by IHC. Increased expression of Psoriasin was significantly correlated with a poor overall BC patient survival. Overexpression of Psoriasin in the EJ138 cell line increased cellular proliferation, adhesion and invasion, whereas knockdown exhibited the opposite effect on cellular functions in RT112 cells. Matrix metalloprotease (MMP)9 appeared to be the most affected of the three MMPs examined in these two BC cell lines. The analysis revealed a positive correlation in BC tumours between Psoriasin and MMP9. Overall, high Psoriasin expression was correlated with poor overall survival in BC patients and promoted invasiveness of BC cells via upregulation of MMPs. Psoriasin possesses certain prognostic and therapeutic potential in BC which requires further exploration

Direct Signal Detection Without Data‐Aided: A MIMO Functional Network Approach

Functional network (FN) has been successfully applied in many fields, but so far no methods of direct signal detection (DSD) using FN have been published. In this chapter, a novel DSD approach using FN, which can be applied to cases with a plural source signal sequence, with short sequence, and even with the absence of a training sequence, is presented. Firstly, a multiple‐input multiple‐output FN (MIMOFN), in which the initial input vector is devised via QR decomposition of the receiving signal matrix, is constructed to solve the special issues of DSD. In the meantime, the design method for the neural function of this special MIMOFN is proposed. Then the learning rule for the parameters of neural functions is trained and updated by back‐propagation (BP) algorithm. The correctness and effectiveness of the new approach are verified by simulation results, together with some special simulation phenomena of the algorithm. The proposed method can detect the source sequence directly from the observed output data by utilizing MIMOFN without a training sequence and estimating the channel impulse response

Genetic deletion of Rnd3 results in aqueductal stenosis leading to hydrocephalus through up-regulation of Notch signaling

Rho family guanosine triphosphatase (GTPase) 3 (Rnd3), a member of the small Rho GTPase family, is involved in the regulation of cell actin cytoskeleton dynamics, cell migration, and proliferation through the Rho kinase-dependent signaling pathway. We report a role of Rnd3 in the pathogenesis of hydrocephalus disorder. Mice with Rnd3 genetic deletion developed severe obstructive hydrocephalus with enlargement of the lateral and third ventricles, but not of the fourth ventricles. The cerebral aqueducts in Rnd3-null mice were partially or completely blocked by the overgrowth of ependymal epithelia. We examined the molecular mechanism contributing to this Rnd3-deficiency–mediated hydrocephalus and found that Rnd3 is a regulator of Notch signaling. Rnd3 deficiency, through either gene deletion or siRNA knockdown, resulted in a decrease in Notch intracellular domain (NICD) protein degradation. However, there was no correlated change in mRNA change, which in turn led to an increase in NICD protein levels. Immunoprecipitation analysis demonstrated that Rnd3 and NICD physically interacted, and that down-regulation of Rnd3 attenuated NICD protein ubiquitination. This eventually enhanced Notch signaling activity and promoted aberrant growth of aqueduct ependymal cells, resulting in aqueduct stenosis and the development of congenital hydrocephalus. Inhibition of Notch activity rescued the hydrocephalus disorder in the mutant animals

In-situ synthesis of ultra-fine ZrB2–ZrC–SiC nanopowders by sol-gel method

© 2019 Elsevier Ltd and Techna Group S.r.l. ZrB2–ZrC–SiC nanopowders with uniform phase distribution were prepared from cost-effective ZrOCl2·8H2O by a simple sol-gel method. The synthesis route, ceramization mechanism and morphology evolution of the nanopowders were investigated. ZrB2–ZrC–SiC ceramic precursor can be successfully obtained through hydrolysis and condensation reactions between the raw materials. Pyrolysis of the precursor was completed at 650 °C, and it produced ZrO2, SiO2, B2O3 and amorphous carbon with a yield of 39% at 1300 °C. By heat-treated at 1500 °C for 2 h, highly crystallized ZrB2–ZrC–SiC ceramics with narrow size distribution were obtained. With the holding time of 2 h, both the crystal size and the particle size can be refined. Further prolonging the holding time can lead to serious particles coarsening. Studies on the microstructure evolution of the generated carbon during the ceramic conversion demonstrates the negative effect of the ceramic formation on the structure order improvement of the carbon, due to the large amount of defects generated in it by the boro/carbothermal reduction reactions

CT-guided iodine-125 brachytherapy as salvage therapy for local-regional recurrent breast cancer

BackgroundThe treatment of local–regional recurrent breast cancer (BC) after external beam radiotherapy is challenging. We aim to evaluate the effectiveness and safety of computed tomography (CT)–guided percutaneous iodine-125 brachytherapy for local recurrent BC.MethodsWe retrospectively analyzed 15 patients with local recurrent BC treated with CT-guided interstitial implantation of iodine-125 seeds. Regular contrast-enhanced CT was conducted to evaluate the tumor response. Follow-up survival, quality of life, and adverse events were analyzed.ResultsAmong the 15 patients, five were elderly patients (older than 80 years) and six were complicated with chronic underlying diseases. The median number of 125I seeds implantation was 33 (range: 20–130) with median dose 90 (D90, the minimum dose covering 90% of the target volume) of 108 Gy (range: 60–120 Gy). There was no significant difference in D90, V100 (the volume of the target receiving 100% of the prescription dose), and V150 (the volume of the target receiving 150% of the prescription dose) before and after operation (p > 0.05). The median follow-up was 14 months (range: 6–18 months). Six months after operation, the ORR was 66.7% (10/15) and the LCR was 93.3% (14/15). The 6- and 12-month survival rates were 100 and 41.6%, respectively, and the median survival time was 12.5 months. PS score decreased from 1.53 ± 0.81 to 0.53 ± 0.49. The pain score decreased from 2.87 ± 1.67 before operation to 1.07 ± 1.18 after operation, and the differences were statistically significant (p< 0.05). No severe complications occurred.ConclusionsCT-guided iodine-125 brachytherapy provided a safe and effective choice for recurrent BC with significant local therapeutic effects and minor complications, especially for elderly patients with chronic underlying disease and those who were not eligible for surgical resection and had failed to benefit from systemic therapy