高原人体左心室舒张功能和顺应性的改变

应用同步描记心电图、心音图、颈动脉搏动图和心尖搏动图以测定高原人体的左心室舒张功能和顺应性。在4个不同海拔高度进行实验,即76m(海平对照)、2161m、3270m和4179m,每一高度40名健康男性青年,高原3组世居、移居各20名。结果显示:随着海拔增高,主动舒张时间指数(TRTI)有减小趋势,RF波相对振幅(F/H)逐渐降低,A波相对振幅(A/D)则渐趋增大,3270m以上增大明显(p<0.05),舒张振幅时间指数(DATI)逐渐降低,3270m以上差异极显著(p<0.001)。高原世居与移居者相比,在海拔4179m出现明显差别,移居组TRTI、DATI、F/H较低而A/D较高(D<0.05)。测定射血前期与左室射血时间比值(PEP/LVET)、射血分数(EF)及左室周径纤维平均缩短速度(mVcf)3项指标作对照,显示在此高度左室收缩功能仍能保持。高原慢性心肌缺氧可能是导致左室舒张功能和顺应性轻度降低的原因。     

Hollow CuS Nanoboxes as Li‐Free Cathode for High‐Rate and Long‐Life Lithium Metal Batteries

Transition metal sulfides hold promising potentials as Li‐free conversion‐type cathode materials for high energy density lithium metal batteries. However, the practical deployment of these materials is hampered by their poor rate capability and short cycling life. In this work, the authors take the advantage of hollow structure of CuS nanoboxes to accommodate the volume expansion and facilitate the ion diffusion during discharge–charge processes. As a result, the hollow CuS nanoboxes achieve excellent rate performance (≈371 mAh g^?1 at 20 C) and ultra‐long cycle life (>1000 cycles). The structure and valence evolution of the CuS nanobox cathode are identified by scanning electron microscopy, transmission electron microscopy, and X‐ray photoelectron spectroscopy. Furthermore, the lithium storage mechanism is revealed by galvanostatic intermittent titration technique and operando Raman spectroscopy for the initial charge–discharge process and the following reversible processes. These results suggest that the hollow CuS nanobox material is a promising candidate as a low‐cost Li‐free cathode material for high‐rate and long‐life lithium metal batteries.     

Root-tip cutting and uniconazole treatment improve the colonization rate of Tuber indicum on Pinus armandii seedlings in the greenhouse

The Chinese black truffle Tuber indicum is commercially valuable. The main factors influencing the success or failure of a truffle crop include the mycorrhizal colonization rate and host plant quality. The effects of a plant growth regulator (uniconazole) and plant growth management technique (root-tip cutting) on T. indicum colonization rate and Pinus armandii seedling growth were assessed under greenhouse conditions. The results indicated that 10 mg l⁻¹ uniconazole or the combination of 5 mg l⁻¹ uniconazole and root-tip cutting constitutes an effective method for ectomycorrhizal synthesis based on an overall evaluation of colonization rate, plant biomass, plant height, root weight, stem circumference and antioxidant enzyme activities (SOD and POD) of P. armandii. The abundance of Proteobacteria in the rhizosphere of colonized seedlings might serve as an indicator of stable mycorrhizal colonization. This research inspires the potential application of uniconazole and root-tip cutting treatments for mycorrhizal synthesis and truffle cultivation.     

Binding mechanism of maltol with catalase investigated by spectroscopy,molecular docking,and enzyme activity assay

Maltol is a flavor additive that is widely used in the daily diet of humans, and its biosafety attention is concomitantly increasing. Catalase (CAT) is an antioxidant enzyme to maintain homeostasis in the tissue's environment of human body and protect cells from oxidative damages. The adverse effects of maltol to CAT activity within mouse hepatocytes as well as the structural and functional changes of CAT on molecular level were investigated by multiple spectroscopy techniques, enzyme activity experiments, and molecular docking. Results suggested that when the maltol concentrations reached to 8 × 10^?5 mol L^?1, the viability of hepatocytes decreased to 93%, and CAT activity was stimulated by maltol to 111% than the control group after exposure for 24 hours. Changes in CAT activity on molecular level were consistent with those on cellular level. The fluorescence quenching of CAT by maltol was static with the forming of maltol‐CAT complex. Moreover, ultraviolet‐visible (UV‐visible) absorption, synchronous fluorescence, and circular dichroism (CD) spectra reflected that the presence of maltol caused conformational change of CAT and made the CAT molecule skeleton loose and increased α‐helix of CAT. Maltol mainly bound with CAT through hydrogen bond, and binding site that is near the heme ring in the enzyme activity center did not interact with its main amino acid residues. This study explores the combination between maltol and CAT, providing references for evaluating health damages caused by maltol.     

Approaches to promoting bone marrow mesenchymal stem cell osteogenesis on orthopedic implant surface

Bone marrow-derived mesenchymal stem cells(BMSCs) play a critical role in the osseointegration of bone and orthopedic implant. However, osseointegration between the Ti-based implants and the surrounding bone tissue must be improved due to titanium's inherent defects. Surface modification stands out as a versatile technique to create instructive biomaterials that can actively direct stem cell fate. Here, we summarize the current approaches to promoting BMSC osteogenesis on the surface of titanium and its alloys. We will highlight the utilization of the unique properties of titanium and its alloys in promoting tissue regeneration, and discuss recent advances in understanding their role in regenerative medicine. We aim to provide a systematic and comprehensive review of approaches to promoting BMSC osteogenesis on the orthopedic implant surface.     

Length-weight relationships of eight fish species from the Hailang river,China

The present study reports the length-weight relationships (LWRs) for eight fish species sampled in Hailang River, a left-bank tributary of the Mudan River in Northeast China. The fishes were collected from April to October bimonthly 2017 by electrofishing (fishing 2 kilometers along the river and within 5 meters from the bank) and netting (drift gillnet: mesh size 2 cm × 3 cm; 200 m net length). The specimens were weighed (nearest 0.1 g) and measured (nearest 0.1 cm) in the laboratory. This study provides an update in maximum lengths for five species.     

PARP1 rs1136410 C/C genotype associated with an increased risk of esophageal cancer in smokers

Molecular Biology Reports - DNA repair system plays a crucial role in maintaining genomic integrity and stability and in protecting against cancer. Poly(ADP-ribose) polymerase 1 (PARP1) functions...     

Sustainability of SARS-CoV-2 Induced Humoral Immune Responses in COVID-19 Patients from Hospitalization to Convalescence Over Six Months

Virologica Sinica - Understanding the persistence of antibody in convalescent COVID-19 patients may help to answer the current major concerns such as the risk of reinfection, the protection period...