Investigation on Thermal Insulation and Mechanical Strength of Lightweight Aggregate Concrete and Porous Mortar in Cold Regions

Thermal insulation is an important indicator to evaluate the construction material in cold region engineering.As we know,adding the industrial waste as lightweight aggregate or creating the pore inside the cement-based composite could make the texture loose,and the thermal insulating capacity of the material would be improved with this texture.Using these methods,the industrial by-product and engineering waste could be cycled in an efficient way.Moreover,after service the fragmented cement composites paste could be used as aggregate in the thermal insulating concrete again.While the porous texture is not favorable for the mechanical strength and long-term durability in a cold environment.To balance the above three requirements from two opposite directions,different processing methods were applied to create the thermal insulation concrete/mortar.Firstly,the organic/inorganic lightweight aggregate,including the Expanded Polystyrene(EPS),Expanded Perlite(EP),and Ceramsite(CRMST)particles,were applied to create the Lightweight Aggregate Concrete(LWAC).As the comparative tests,the expanded Superabsorbent Polymer(SAP)hydrogel and Air-Entraining Agent(AEA)were also introduced to create the porous mortar.The above concrete/mortar was tested in the normal state and under the Freeze-Thaw cycle to explore the engineering performance in cold regions.During the experimenting process,the thermal insulation,mechanical strength,and frost resistance of these cement-based composites were investigated,and an optimal thermal insulation concrete/mortar was determined.

Evolutionary trajectory of TRPM2 channel activation by adenosine diphosphate ribose and calcium

Ion channel activation upon ligand gating triggers a myriad of biological events and,therefore,evolution of ligand gating mechanism is of fundamental importance.TRPM2,a typical ancient ion channel,is activated by adenosine diphosphate ribose(ADPR)and calcium and its activation has evolved from a simple mode in invertebrates to a more complex one in vertebrates,but the evolutionary process is still unknown.Molecular evolutionary analysis of TRPM2s from more than 280 different animal species has revealed that,the C-terminal NUDT9-H domain has evolved from an enzyme to a ligand binding site for activation,while the N-terminal MHR domain maintains a conserved ligand binding site.Calcium gating pattern has also evolved,from one Ca^(2+)-binding site as in sea anemones to three sites as in human.Importantly,we identified a new group represented by olTRPM2,which has a novel gating mode and fills the missing link of the channel gating evolution.We conclude that the TRPM2 ligand binding or activation mode evolved through at least three identifiable stages in the past billion years from simple to complicated and coordinated.Such findings benefit the evolutionary investigations of other channels and proteins.

Intrinsic Kinematics of the Tibiotalar and Subtalar Joints during Human Walking based on Dynamic Biplanar Fluoroscopy

Accurate knowledge of the kinematics of the in vivo Ankle Joint Complex(AJC)is critical for understanding the biomechanical function of the foot and assessing postoperative rehabilitation of ankle disorders,as well as an essential guide to the design of ankle–foot assistant devices.However,detailed analysis of the continuous 3D motion of the tibiotalar and subtalar joints during normal walking throughout the stance phase is still considered to be lacking.In this study,dynamic radiographs of the hindfoot were acquired from eight subjects during normal walking.Natural motions with six Degrees of Freedom(DOF)and the coupled patterns of the two joints were analyzed.It was found that the movements of the two joints were mostly in opposite directions(including rotation and translation),mainly in the early and late stages.There were significant differences in the Range of Motion(ROM)in Dorsiflexion/Plantarflexion(D/P),Inversion/Eversion(In/Ev),and Anterior–Posterior(AP)and Medial–Lateral(ML)translation of the tibiotalar and subtalar joints(p<0.05).Plantarflexion of the tibiotalar joint was coupled with eversion and posterior translation of the subtalar joint during the impact phase(R^(2)=0.87 and 0.86,respectively),and plantarflexion of the tibiotalar joint was coupled with inversion and anterior translation of the subtalar joint during the push-off phase(R^(2)=0.93 and 0.75,respectively).This coordinated coupled motion of the two joints may be a manifestation of the AJC to move flexibly while bearing weight and still have stability.

In vivo noninvasive study of diabetic peripheral neuropathy plantar morphology and mechanical properties based on ultrasound

To the Editor:The incidence of diabetes complications increases with the increase in diabetes incidence.Diabetic peripheral neuropathy(DPN)is one of the most common complications in diabetes patients.DPN is very harmful and is an important cause of diabetic foot and amputation.The amputation rate of DPN patients is 10-20 times higher than that of nondiabetic patients.Every 30 s,somewhere in the world,a patient’s lower limb or part of a lower limb will be surgically amputated due to DPN.[1]DPN seriously interferes with the physical and mental health of patients.At the same time,the high cost of treatment and rehabilitation care also causes huge economic pressure on patients.Therefore,it is particularly important to identify,diagnose,and prevent DPN in the early or ultra-early stage.