Neural stem cell transplantation alleviates functional cognitive deficits in a mouse model of tauopathy

The mechanisms of the transplantation of neural stem cells(NSCs)in the treatment of Alzheimer’s disease remain poorly understood.In this study,NSCs were transplanted into the hippocampal CA1 region of the rTg(tau P301L)4510 mouse model,a tauopathy model that is thought to reflect the tau pathology associated with Alzheimer’s disease.The results revealed that NSC transplantation reduced the abnormal aggregation of tau,resulting in significant improvements in the short-term memory of the tauopathy model mice.Compared with wild-type and phosphate-buffered saline(PBS)-treated mice,mice that received NSC transplantations were characterized by changes in the expression of multiple proteins in brain tissue,particularly those related to the regulation of tau aggregation or misfolding.Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analysis and Gene Ontology(GO)function analysis revealed that these proteins were primarily enriched in pathways associated with long-term potentiation,neurogenesis,and other neurobiological processes.Changes in the expression levels of key proteins were verified by western blot assays.These data provided clues to improve the understanding of the functional capacity associated with NSC transplantation in Alzheimer’s disease treatment.This study was approved by the Beijing Animal Ethics Association and Ethics Committee of Beijing Institute of Technology(approval No.SYXK-BIT-school of life science-2017-M03)in 2017.

Coupling ideality of standing-wave supermode microresonators

Standing-wave supermode microresonators that are created through the strong coupling between counter-propagating modes have emerged as versatile platforms for sensing and nonlinear optics.For example,these microresonators have shown potential in nanoparticle sizing and counting,as well as enhancing the single-photon optomechanical coupling rate of stimulated Brillouin scattering.However,it has been observed that the relation between the mode linewidth and on-resonance transmission of the split supermodes differs obviously from that of the non-split modes.This behavior is typically quantified by the coupling ideality(I),which remains inadequately explored for the standing-wave supermodes.In this study,we theoretically and experimentally investigate the coupling ideality of standing-wave supermodes in a commonly employed configuration involving a Si O2microresonator side-coupled to a tapered fiber.Our findings demonstrate that,even with a single-mode tapered fiber,the coupling ideality of the standing-wave supermodes is limited to 0.5,due to the strong backscattering-induced energy loss into the counter-propagating direction,resulting in an additional equivalent parasitic loss.While achieving a coupling ideality of 0.5 presents challenges for reaching over-coupled regimes,it offers a convenient approach for adjusting the total linewidth of the modes while maintaining critically-coupled conditions.

Thermal effect of the accumulated water with different depths on permafrost subgrade in cold regions

In cold regions,the thermal effect of accumulated water on underlying permafrost and permafrost subgrade remains a significant hazard causing engineering risks.Water depth of accumulated water may be an important influence factor of permafrost thermal stability,but there is lack of qualitative and quantitative research about that.In this study,equivalent thermal conductivity theory and solid heat transfer theory have been used to establish the calculation model for simulating heat transfer in water and soil.Thereafter,the accuracy and reliability of the calculation model are checked by monitored data and subsequently used to analyze the thermal erosion of water on underlying permafrost and permafrost under the embankment.These simulation results show that shallow water can protect permafrost and deeper water disrupts the thermal stability of underlying permafrost.The thermal effect extent of water is primarily determined by its depth,and the concept of critical depth and stable depth of accumulated water has been proposed.Moreover,the temperature field of permafrost under embankment can be changed by the slope toe water.In addition,the thermal effect range of the slope toe water is limited by the thermal influence radius,which increases with the depth of standing water.These findings provide support as well as a fundamental base for environmental issues arising from the accumulated water.These observations will,thus,also be valuable to further engineering environment studies in cold regions.

A Better Semi-online Algorithm for Q3/s_1=s_2≤s_3/C_(min) with the Known Largest Size

This paper investigates the semi-online machine covering problem on three special uniform machines with the known largest size. Denote by sj the speed of each machine, j = 1, 2, 3. Assume 0 〈 s1 = s2 = r 〈 t = s3, and let s = t/r be the speed ratio. An algorithm with competitive ratio max（2, 3s＋6/s＋6 is presented. We also show the lower bound is at least max（2, 38 3s/s＋6）. For s ≤ 6, the algorithm is an optimal algorithm with the competitive ratio 2. Besides, its overall competitive ratio is 3 which matches the overall lower bound. The algorithm and the lower bound in this paper improve the results of Luo and Sun.