脑卒中患者运动功能自动化评定研究进展

采用量表方式对脑卒中患者进行运动功能评定,存在效率低、主观性强等不足。基于传感器技术和机器学习方法的脑卒中运动功能自动化评定,可针对脑卒中患者的运动控制、平衡、步态、关节活动度等运动功能进行自动化评定,开发了许多产品。     

估计点扩展函数对内源性光学成像信号的提取

脑内源信号光学成像是近十几年发展起来的研究大脑皮层神经群体活动的成像方法.内源性光学信号非常微弱,并且在穿过皮层组织时会发生扩散,使得图像存在一定程度的退化.本研究通过对功能图像的二阶统计量分析,选取功能柱区域与非功能柱区域像素进行联合求解高斯函数,得到针对内源性光学信号的点扩展函数的估计,并对内源性光学信号图像进行恢...     

乳腺CEUS预测模型诊断乳腺恶性病灶的观察者间一致性:多中心研究

目的 探讨拉伸指数模型DWI鉴别诊断乳腺良恶性病变的价值。方法 收集58例乳腺病变患者,共63个病灶（良性33个,恶性30个）,行多b值DWI及动态增强MRI （DCE-MRI）扫描。计算ADC、扩散分布指数（DDC）和扩散异质性指数（α）值,并生成时间-信号强度曲线（TIC）。比较良恶性病变间各参数差异,采用ROC曲线评价各参数诊断效能。结果 恶性病变ADC、DDC和α分别为（1.01±0.19）×10^-3 mm²/s、（0.89±0.23）×10^-3 mm²/s和0.75±0.09,良性病变分别为（1.41±0.27）×10^-3 mm²/s、（1.49±0.29）×10^-3 mm²/s和0.87±0.07,恶性病变均低于良性病变（P均<0.01）。各参数中DDC曲线下面积（AUC）最大（AUC=0.958）,最佳诊断界值1.22×10^-3 mm²/s,敏感度和特异度分别为96.67%、81.82%,DDC与TIC联合所得AUC为0.976,对应敏感度和特异度分别为93.33%、93.94%。结论 拉伸指数模型DWI参数DDC、α能够鉴别诊断乳腺良恶性病变,DDC与TIC联合的诊断效能高于ADC和DCE。     

High-efficiency and stable piezo-phototronic organic perovskite solar cell

Perovskite materials are regarded as next-generation organic photovoltaic (OPV) materials due to their excellent physical and chemical properties. Recent theoretical and experimental advances also revealed the piezoelectric properties of CH₃NH₃PbI₃ perovskite thin films. In this work, a CH₃NH₃PbI₃ perovskite piezo-phototronic solar cell is studied in theory. The output parameters such as open circuit voltage, current–voltage characteristics, fill factor, power conversion efficiency, and maximum output power with external strains are presented. The coefficient to characterize piezo-phototronic modulation is also calculated for the piezo-phototronic solar cell. With the change of strain, the output performance can be controlled and enhanced. This principle can offer not only a novel and unique approach to produce high-performance, stable perovskite solar cells, but also a principle to design new piezoelectric perovskite optoelectronic devices.

Enhancing the performance of perovskite solar cells with strain based on a piezo-phototronic effect.     

Coexistence of Co doping and strain on arsenene and antimonene: tunable magnetism and half-metallic behavior

Effectively modulating the magnetism of two-dimensional (2D) systems is critical for the application of magnetic nanostructures in quantum information devices. In this work, by employing density functional theory calculations, we found the coexistence of Co doping and strain can effectively control the spin states of arsenene and antimonene structures. Unstrained Co-doped arsenene (arsenene–Co) and Co-doped antimonene (antimonene–Co) structures are nonmagnetic while under a strain, the magnetic moments of both cases were abruptly increased to about 2 μ_B. The emergence of magnetism can be reflected by the reduction of the interactions between Co and its neighboring atoms by the strain, which leads to the spin-splitting of Co-3d states. More importantly, we found that the transition of magnetism accompanies the modifications of the electronic properties of arsenene and antimonene so that under strain both structures can exhibit a novel half-metallic behavior. These results provide an effective pathway for the development of arsenene- and antimonene-based electronic devices by applying Co doping and strain.

Effectively modulating the magnetism of two-dimensional (2D) systems is critical for the application of magnetic nanostructures in quantum information devices.     

Implantable vaccine development using in vitro antigen-pulsed macrophages absorbed on laser micro-structured Si scaffolds

To overcome the limiting antigenic repertoire of protein sub-units and the side effects of adjuvants applied in second generation vaccines, the present work combined in vitro and in vivo manipulations to develop biomaterials allowing natural antigen-loading and presentation in vitro and further activation of the immune response in vivo. 3-dimensional laser micro-textured implantable Si-scaffolds supported mouse macrophage adherence, allowed natural seeding with human serum albumin (antigen) and specific antibody and inflammatory cytokine production in vitro. Implantation of Si-scaffolds loaded with antigen-activated macrophages induced an inflammatory reaction along with antigen-specific antibody production in vivo, which could be detected even 30 days post implantation. Analysis of implant histology using scanning electron microscopy showed that Si-scaffolds could be stable for a 6-month period. Such technology leads to personalized implantable vaccines, opening novel areas of research and treatment.     

Perceptual and response interference in Alzheimer’s disease and mild cognitive impairment

Objectives

The ability to resolve conflicts is indispensable to the function of daily life and decreases with cognitive decline. We hypothesized that subjects with different levels of cognitive impairment exhibit different conflict resolution performances and may be susceptible to interference effects at different stages.

Methods

Sixteen normal controls (NC), 15 mild cognitive impairment (MCI) and seven Alzheimer’s disease (AD) patients were recruited to perform in a modified Eriksen flanker task.

Results

We observed that the AD and MCI patients exhibited smaller accuracy rate and longer response time compared to NC subjects. Longer N2 and P300 latencies were observed in the AD group. Furthermore, the MCI group showed a longer latency than the NC group in the P300 latency. The magnitude of the perceptual and response interference effects was larger in the AD group than the other groups, and the MCI group significantly differed from the NC group at the perceptual level.

Conclusion

The ability to resolve conflict decreased with impaired cognition and the perceptual and response interference effects may be useful in distinguishing MCI and AD.

Significance

The perceptual or response interference effect may potentially be employed as a useful non-invasive probe for the clinical diagnosis of MCI and AD.     

Novel Reticular Cyclen‐Based Polymer as Gene Vector in DNA Transfection

This study provided an experimental evidence for the use of cyclen (1, 4, 7, 10‐tetraazacyclododecane)‐based polymer for gene delivery. The interesting interaction of the polymer with plasmid DNA was studied by using fluorescence titration, circular dichroism spectra, agarose gel electrophoresis and atomic force microscopy. It was found that polyplex was formed between the polycation and plasmid DNA. The results demonstrated that the cyclen‐based polymer could act as non‐viral gene vector with relatively low cytotoxicity.     

Theoretical investigations of the Jahn–Teller distortions for V and Cr in α-Al2O3

The spin Hamiltonian parameters (zero-field splittings D, g factors g_// and g_⊥, the hyperfine structure constants and the spin–lattice coupling coefficients |G_–|, |G₁₅|, |G₅₁| and |G₄₄|) for V³⁺ and Cr⁴⁺ in α-Al₂O₃ are theoretically investigated from the perturbation formulas of these parameters for a 3d² ion under trigonally distorted octahedra. In these formulas, the contributions from the dynamical Jahn–Teller effect, the configuration interactions and the ligand orbital and spin–orbit coupling interactions are quantitatively taken into account in a uniform way based on the ligand field model. The impurity-ligand bond angles related to the C₃ axis are found to experience the variations of about 1.5–1.9° due to the dynamical Jahn–Teller nature, yielding more regular octahedra around the 3d² impurities. In addition, the size mismatching substitution of the smaller host Al³⁺ by the larger impurities may also bring forward some contributions to the local angular distortions. All the calculated spin Hamiltonian parameters based on the above angular variations show reasonable agreement with the experimental data for both centers. The improvements are achieved in this work by adopting the uniform model and formulas and much fewer adjustable parameters as compared with the previous treatments.     

Gaussian source model based iterative algorithm for EEG source imaging

Estimation of the neural active sources from the scalp electroencephalogram (EEG) is an ill-posed inverse problem. In this paper, we propose a new source model: Gaussian distributed Source Model (GSM), to model the activations in brain. GSM may imitate an Isolated Source Model (ISM) or a Distributed Source Model (DSM) by adopting different supporting range parameter of the Gaussian function. Using GSM, an iterative Gaussian source Imaging Algorithm (GIA) is developed to detect the EEG sources. As GIA dynamically reduces the solution space, the solution may gradually converge to a desired distribution. A comparative evaluation among LORETA, FOCUSS and GIA was conducted for both isolated point sources and distributed sources, the results demonstrate that GIA is more flexible and efficient for various actual sources configurations. Finally, GSM was applied to real recordings obtained from a visual spatial attention task; the corresponding source activation areas of the early component are localized in contralateral occipital cortices, consistent with the retinotopic organization of early visual spatial attention effects.