影响颅内室管膜瘤患者生存和预后的相关因素分析

目的:研究影响颅内室管膜瘤患者生存和预后的相关因素,为临床治疗提供理论依据。方法:回顾性分析2008年1月至2018年1月中南大学湘雅医院收治的颅内室管膜瘤患者276例,分析性别、年龄、肿瘤部位、肿瘤直径、手术切除程度、病理分级、Ki-67指数、术后是否放疗、术后是否化疗对颅内室管膜瘤患者总生存时间和无进展生存时间的影响。结果:肿瘤部位、手术切除程度、术后是否放疗均能影响颅内室管膜瘤患者总生存时间和无进展生存时间(P<0.001),并且是影响总生存时间(P<0.001,P<0.001,P=0.002)和无进展生存时间(P<0.001,P<0.001,P<0.001)的独立因素;Ki-67指数是影响颅内室管膜瘤患者无进展生存的独立因素(P<0.001)。肿瘤位于幕上、Ki-67指数≥10%是提示预后不佳的独立危险因素(P<0.001),肿瘤全切、术后行放疗是保护因素(P<0.001,P=0.001)。结论:肿瘤部位、手术切除程度、Ki-67指数、术后是否放疗是响颅内室管膜瘤预后的独立因素,尽可能的肿瘤全切和术后放疗有助于延长患者的无进展生存时间和总生存时间。

基于非对称纤维素纳米纤维异质膜的水传输促进渗透能量转换

海洋渗透能是最有前景的可持续能源之一.非对称纳米通道膜由于其优越的离子选择性在海洋渗透能转化中受到广泛关注,但较低的离子通量仍然是其需要突破的瓶颈.本文采用纤维素纳米纤维和磺化聚砜(SPSf40)制备了非对称异质膜,这种非对称异质膜有效地提高了离子电导率,通过混合人工河流和海水的输出功率密度可达8.3 W/m^(2).与传统的离子交换膜相比,非对称异质膜的离子电导率和最大功率密度分别提高了325.0%和48.2%.从海水(非对称异质膜的疏水侧)到河水(非对称异质膜的亲水侧)的输运抑制了水的渗透压,有助于高离子的传输通量,提高了海洋渗透能量转换效率.高离子选择性的浸润梯度膜为渗透转化膜的开发提供了一种新方法.

Corrosion Behavior of Graphene Nanosheets Reinforced Magnesium Matrix Composites in Simulated Body Fluids

Magnesium(Mg)alloy is considered as a promising biodegradable implant material but restricted to rapid degradation.Here,the new strategies based on thixomolding process had been explored to utilize the outstanding anti-permeability of graphene nanosheets(GNPs)while inhibit its galvanic corrosion with the matrix,so as to improve the corrosion resistance of composites.The agglomerate of GNPs with 0.9 wt%content is the main reason for the deterioration of corrosion performance due to the formation of micro-galvanic corrosion.The grain refinement of composites with 0.6 wt%content had positive effects on the better corrosion resistance.After process adjusting,the unique distributions of GNPs along grain boundaries play a vital role in improving the corrosion resistance.It can be ascribed to the following mechanisms:(I)The barriers can be established between the Mg matrix and corrosive medium,hence blocking the charge transfer at the interface;(II)The GNPs can effectively promote apatite deposition on the Mg matrix,leading to form dense apatite layers and prevent the further invasion of SBF;(III)The GNPs acting as reinforcements exists in the corrosion layer and apatite layer,impede the apatite layer falling off from the Mg matrix.These findings broaden the horizon for biomedical applications in Mg matrix composites to realize desired performances.

The mechanism of dentine hypersensitivity:Stimuli-induced directional cation transport through dentinal tubules

Dentine hypersensitivity is an annoying worldwide disease,yet its mechanism remains unclear.The long-used hydrodynamic theory,a stimuli-induced fluid-flow process,describes the pain processes.However,no experimental evidence supports the statements.Here,we demonstrate that stimuli-induced directional cation transport,rather than fluid-flow,through dentinal tubules actually leads to dentine hypersensitivity.The in vitro/in vivo electro-chemical and electro-neurophysiological approaches reveal the cation current through the nanoconfined negatively charged dentinal tubules coming from external stimuli(pressure,pH,and temperature)on dentin surface and further triggering the nerve impulses causing the dentine hypersensitivity.Furthermore,the cationic-hydrogels blocked dentinal tubules could significantly reduce the stimuli-triggered nerve action potentials and the anionhydrogels counterpart enhances those,supporting the cation-flow transducing dentine hypersensitivity.Therefore,the inspired ion-blocking desensitizing therapies have achieved remarkable pain relief in clinical applications.The proposed mechanism would enrich the basic knowledge of dentistry and further foster breakthrough initiatives in hypersensitivity mitigation and cure.

Pair density wave facilitated by Bloch quantum geometry in nearly flat band multiorbital superconductors

Bloch electrons in multiorbital systems carry quantum geometric information characteristic of their wavevector-dependent interorbital mixing.The geometric nature impacts electromagnetic responses,and this effect carries over to the superconducting state,which receives a geometric contribution to the superfluid weight.In this paper,we show that this contribution could become negative under certain appropriate circumstances.This may facilitate the stabilization of Cooper pairings with real space phase modulation,i.e.,the pair density wave order,as we demonstrate through two-orbital model Bogoliubov de-Gennes mean-field calculations.The quantum geometric effect therefore constitutes an intrinsic mechanism for the formation of such a novel phase of matter in the absence of external magnetic field.

Temperature difference-enhanced salinity gradient energy conversion enabled by thermostable hydrogel membrane with anti-swelling property

Coupling low-grade heat(LGH)with salinity gradient is an effective approach to increase the efficiency of the nanofluidic-membrane-based power generator.However,it is a challenge to fabricate membranes with high charge density that ensures ion permselectivity,while maintaining chemical and mechanical stability in this composite environment.Here,we develop a bis[2-(methacryloyloxy)ethyl]phosphate(BMAP)hydrogel membrane with good thermal stability and anti-swelling property through self-crosslinking of the selected monomer.By taking advantage of negative space charge and three-dimensional(3D)interconnected nanochannels,salinity gradient energy conversion efficiency is substantially enhanced by temperature difference.Theoretical and experimental results verify that LGH can largely weaken the concentration polarization,promoting transmembrane ion transport.As a result,such a hydrogel membrane delivers high-performance energy conversion with a power density of 11.53 W·m^(−2)under a negative temperature difference(NTD),showing a 193%increase compared with that without NTD.

Osmotic-Enhanced-Photoelectrochemical Hydrogen Production Based on Nanofluidics

Harvesting clean energy such as solar energy and salinity gradient energy directly from the surrounding environment has attracted great attention.A promising proof-of-concept combination of cation-selective membrane-based osmotic energy with photoelectrochemical-based solar energy has been developed,highlighting the great potential for the direct conversion of osmotic energy to hydrogen energy.With the help of a 50-fold concentration gradient,the MXene-CdSe quantum dots system exhibits the highest photocurrent enhancement ratio(Δ/_(L-H)/Δ/_(L-L)),and the hydrogen production is increased by about 33%at a bias of 0 V versus reversible hydrogen electrode.Directly converting osmotic energy and solar energy into hydrogen energy suggests the possibility of coupling osmotic energy with other renewable energy sources.

Phase-field simulation for the evolution of solid/liquid interface front in directional solidification process

In this study, the phase field method was used to study the multi-controlling factors of dendrite growth in directional solidification. The effects of temperature gradient, propelling velocity, thermal disturbance and growth orientation angle on the growth morphology of the dendritic growth in the solid/liquid interface were discussed. It is found that the redistribution of solute leads to multilevel cavity and multilevel fusion to form multistage solute segregation, and the increase of temperature gradient and propelling velocity can accelerate the dendrite growth of directional solidification, and also make the second dendrites more developed, which reduces the primary distance and the solute segregation. When the temperature gradient is large, the solid-liquid interface will move forward in a flat interface mode,and the thermal disturbance does not affect the steady state behavior of the directionally solidified dendrite tip. It only promotes the generation and growth of the second dendrites and forms the asymmetric dendrite. Meanwhile, it is found that the inclined dendrite is at a disadvantage in the competitive growth compared to the normal dendrite, and generally it will disappear. When the inclination angle is large, the initial primary dendrite may be eliminated by its secondary or third dendrite.

Hendecanuclear [Cu_(6)Gd_(5)] magnetic cooler with high molecular symmetry of D_(3h)

A new family of isostructural 3 d-4 f polymetallic complexes,formulated as [Cu_(6)Ln_(5)(μ_(3)OH)_(9)(C_(4)H_(8)O_(2)N)_(6)(C_(5)H_(4)ON)_(6)(H_(2)O)_(9)]·(ClO_(4))_(6)·(H_(2)O)_(22)(Ln=Pr,1;Nd,2;Sm,3;Eu,4;Gd,5),was successfully isolated through the simple hydrolysis reaction of 2-aminoisobutyric acid,2-hydroxypyridine,Cu(CH_(3)COO)_(2)·H_(2)O,and Ln(ClO_(4))_(3)·6 H_(2)O.Notably,the [Cu_(6)Ln_(5)] clusters with high molecular symmetry of D_(3h) are rare examples of2-aminoisobutyric acid-based 3 d-4 f clusters.The successful theoretical modeling of 5 yielded that the Gd-Gd exchange is of order 0.2 K,whereas the Gd-Cu exchange is an order of magnitude larger.Magnetization data collected for comp lex 5 yield a magnetic entropy change(-ΔSm) of 19.6 J kg^(-1) K^(-1)<1 at 3 K and 7 T,which may be attributed to the weak magnetic interactions between the component metal ions.