Modeling carotid and radial artery pulse pressure waveforms by curve fitting with Gaussian functions

Modeling arterial pressure waveforms holds the potential for identifying physiological changes. There is a clinical need for a simple waveform analysis method with a high accuracy in reproducing the original waveforms. The aim of this study was to determine the accuracy of modeling carotid and radial pulses using Gaussian functions, making no physiological assumptions. Carotid and radial pulses were recorded from 20 normal volunteers. Ten consecutive beats from each volunteer were analyzed to determine beat-to-beat variability. Each pulse was decomposed using seven combinations of up to three Gaussian functions. The first function was always positive, but the second or third could be either positive or negative. Three positive Gaussian functions reproduced the original waveforms best with a mean absolute error (MAE) of 1.2% and 1.3% for the carotid and radial pulses respectively, and a maximum residual error of only 4.1% for both. This model had significantly smaller errors than any of the other six (all P < 0.001). Four positive Gaussian functions were then used to test the stability of this model. An insignificant change of the mean MAE (1.2% for both carotid and radial pulses) was obtained, showing that the stability has been reached with three positive Gaussian functions. The variability of MAE calculated as the standard deviation (SD) over the 10 beats was small at 0.2% for both pulses confirming the repeatability of using three positive Gaussian functions.     

斯夫金小蜂属一新种（膜翅目：金小蜂科）

1989年6月,在吉林省公主岭市我们从为害旱柳Salix mat sudana Koidz枝梢的黑潜蝇Melanagromyza sp.蛹中饲养出一种斯夫金小蜂。经鉴定,该种为斯夫金小蜂属Sphegigaster一新种。模式标本保存于中国科学院动物研究所。吉林斯夫金小蜂Sphegigaster jilinensis Huang,新种(图1～6)     

黑龙江下盾螨属二新种：（蜱螨亚纲）：革螨股：厉螨科）

本文记述下盾螨属２新种：拟胸下盾螨Ｈｙｐｏａｓｐｉｓ（Ｇｅｏｌａｅｌａｐｓ）ｐｒａｅｓｔｅｒｎａｌｏｉｄｅｓ，ｓｐ．ｎｏｖ．和带岭下盾螨Ｈｙｐｏａｓｐｉｓ（Ｇｅｏｌａｅｌａｐｓ）ｄａｉｌｉｎｇｅｎｓｉｓ，ｓｐ．ｎｏｖ．。模式标本保存于吉林省白城市全国鼠疫布氏菌病防治基地。     

Stiffness of photocrosslinkable gelatin hydrogel influences nucleus pulposus cell propertiesin vitro

A key early sign of degenerative disc disease (DDD) is the loss of nucleus pulposus (NP) cells (NPCs). Accordingly, NPC transplantation is a treatment strategy for intervertebral disc (IVD) degeneration. However, in advanced DDD, due to structural damage of the IVD and scaffold mechanical properties, the transplanted cells are less viable and secrete less extracellular matrix, and thus, are unable to efficiently promote NP regeneration. In this study, we evaluated the encapsulation of NPCs in a photosensitive hydrogel made of collagen hydrolysate gelatin and methacrylate (GelMA) to improve NP regeneration. By adjusting the concentration of GelMA, we prepared hydrogels with different mechanical properties. After examining the mechanical properties, cell compatibility and tissue engineering indices of the GelMA-based hydrogels, we determined the optimal hydrogel concentration of the NPC-encapsulating GelMA hydrogel for NP regeneration as 5%. NPCs effectively combined with GelMA and proliferated. As the concentration of the GelMA hydrogel increased, the survival, proliferation and matrix deposition of the encapsulated NPCs gradually decreased, which is the opposite of NPCs grown on the surface of the hydrogel. The controllability of the GelMA hydrogels suggests that these NPC-encapsulating hydrogels are promising candidates to aid in NP tissue engineering and repairing endogenous NPCs.     

Air‐Stable and Dendrite‐Free Lithium Metal Anodes Enabled by a Hybrid Interphase of C60 and Mg

Li metal is an ideal anode material for rechargeable high energy density batteries, but its sensitivity to humid air and uncontrolled dendrite growth limit its practical applications. A novel hybrid interphase is fabricated to address these issues. This interphase consists of dense fullerene (C₆₀) and magnesium metal bilayers, which are deposited successively on lithium foil by vacuum evaporation deposition and contribute to moisture resistance and lithium dendrite suppression. Thanks to this dual‐functional feature, the assembled cells with the modified anodes and commercial LiFePO₄ cathodes exhibit long cycle life (>200 cycles) with high capacity retention (>98.5%). Moreover, even the modified anodes that are exposed to humid air (30% relative humidity) for over 12 h; the cells still deliver excellent performance, comparable to those without exposure. Such a unique hybrid interphase provides a new promising method for fabricating air‐stable and dendrite‐free lithium metal batteries.