An Automatic Implementation of Oropharyngeal Swab Sampling for Diagnosing Respiratory Infectious Diseases via Soft Robotic End-Effectors

The most widely adopted method for diagnosing respiratory infectious diseases is to conduct polymerase chain reaction(PCR)assays on patients’respiratory specimens,which are collected through either nasal or oropharyngeal swabs.The manual swab sampling process poses a high risk to the examiner and may cause false-negative results owing to improper sampling.In this paper,we propose a pneumatically actuated soft end-effector specifically designed to achieve all of the tasks involved in swab sampling.The soft end-effector utilizes circumferential instability to ensure grasping stability,and exhibits several key properties,including high load-to-weight ratio,error tolerance,and variable swab-tip stiffness,leading to successful automatic robotic oropharyngeal swab sampling,from loosening and tightening the transport medium tube cap,holding the swab,and conducting sampling,to snapping off the swab tail and sterilizing itself.Using an industrial collaborative robotic arm,we integrated the soft end-effector,force sensor,camera,lights,and remote-control stick,and developed a robotic oropharyngeal swab sampling system.Using this swab sampling system,we conducted oropharyngeal swab-sampling tests on 20 volunteers.Our Digital PCR assay results(RNase P RNA gene absolute copy numbers for the samples)revealed that our system successfully collected sufficient numbers of cells from the pharyngeal wall for respiratory disease diagnosis.In summary,we have developed a pharyngeal swab-sampling system based on an“enveloping”soft actuator,studied the sampling process,and imple-mented whole-process robotic oropharyngeal swab-sampling.

A novel UHMWPE composite with low friction coefficient for long-term ice sliding

Low friction ice sliding interfaces were critical for ski performance optimization.Traditional fluorinated ski waxes have attracted considerable attention for enhancing the hydrophobicity,anti-wearing,and oxidation resistance of ski–ice base.However,the toxicity and complexity of the waxing process limited batch manufacturing of low-cost and non-toxic ski–ice base,what is more,the wax covering on the base wore and failed during skiing due to the friction between ski and ice.Herein,we demonstrated a novel ultra-high molecular weight polyethylene(UHMWPE)composite that could maintain a low coefficient of friction(COF)with about 0.026 for at least 160 min when skiing on the ice.Microcapsule(MS)could release liquid(liquid paraffin(LP)).The released LP further enhanced the hydrophobicity of UHMWPE’s surfaces when friction occurred,which would maintain the stability and durability of the water film,and achieved superior and long-lasting friction resistance.Compared with other microcapsules with lower hydrophobic core,microcapsules with LP performed the best in reducing the friction of ski base from 0.126 to 0.024.Meanwhile,the COF of the surface kept at about 0.02 even after 12 rapid temperature changes.The presented UHMWPE composite of encapsulated liquids showed great potential and broad application owing to its simplicity and efficiency in winter sports.

Low-temperature activity and mechanism of WO_3-modified CeO_2-TiO_2 catalyst under NH_3-NO/NO_2 SCR conditions

The CeO2‐TiO2(CeTi)and CeO2/WO3‐TiO2(CeWTi)catalysts were prepared by a sol‐gel precipitation method and their NH3‐NO/NO2 selective catalytic reduction(SCR)performance was studied.N2O formation and effect of oxygen concentration on SCR performance over CeWTi catalyst were also investigated while varying the NO2/NOx ratio.Results indicate that fast SCR behavior of CeWTi catalyst has the best NH3‐NO/NO2 SCR performance due to the catalyst reoxidation rate by NO2 higher than by O2.Compared with CeTi catalyst,CeWTi catalyst exhibits higher de‐NOx performance under NH3‐NO/NO2 SCR conditions.As the CeTi and CeWTi catalysts exhibit similar redox property,addition of WO3 provides more acid sites which accelerate the reaction between NH4NO3 and NO to get a superior low‐temperature activity.Amount of N2O formation shows a peak at 250 oC mainly derived from NH4NO3 decomposition.

Hierarchical Manganese Oxide/Carbon Nanocomposites for Supercapacitor Electrodes

MnO2/carbon nanocomposites with hierarchical pore structure and controllable MnO2 loading have been synthesized using a self-limiting growth method. This was achieved by the redox reactions of KMnO4 with sacrificed carbon substrates that contain hierarchical pores. The unique pore structure allows the synthesis of nanocomposites with tunable MnO2 loading up to 83 wt.%. The specific capacitance of the nanocomposites increased with the MnO2 loading; the conductivity measured by electrochemical impedance spectroscopy, on the other hand, decreased with increasing MnO2 loading. Optimization of the MnO2 loading resulted in nanocomposites with high specific capacitance and excellent rate capability. This work provides important fundamental understanding which will facilitate the design and fabrication of high-performance supercapacitor materials for a large variety of applications.

Efficient Synthesis of PbTe Nanoparticle Networks

The synthesis of semiconductor nanocrystalline networks using weak capping ligands in aqueous media has been demonstrated.Carbohydrates,includingβ-cyclodextrin,D-(+)-glucose,D-glucosamine,lactobionic acid,sucrose,and starch were chosen as weak ligands to facilitate the formation of PbTe nanoparticle networks.The nanoparticle size,ranging from 5 nm to 30 nm,can be tuned by manipulating the temperature and concentration.Through a similar strategy,more complicated nanostructures including carbohydrate spheres@PbTe core-shell structures and Te@carbohydrate@PbTe multilayered submicron cables have been fabricated.This is a general approach which can be easily extended to the fabrication of other semiconductor networks,including PbSe and Bi2Te3 using carbohydrates and ethylenediaminetetraacetic acid(EDTA),respectively,as ligands.

Solvothermal synthesis of PbTe/SnTe hybrid nanocrystals

PbTe/SnTe hybrid nanocrystals with designed shape, chemical composition and narrow size distribution were synthesized by an efficient solvothermal approach. This approach enables mass and economical synthesis of PbTe-based nanocrystals. The organic ligands were completely removed by pretreatment with a super-hydride solution, making it possible to fabricate fully dense and robust thermoelectric devices with increased electrical conductivity.

Construction and Application of in vitro Alveolar Models Based on 3D Printing Technology

Increasing lung diseases,mutating coronaviruses,and the development of new compounds urgently require biomimetic in vitro lung models for lung pathology,toxicology,and pharmacology.The current construction strategies for lung models mainly include animal models,2D cell culture,lung-on-a-chip,and lung organoids.However,current models face difficulties in reproducing in vivo-like alveolar size and vesicle-like structures,and are unable to contain multiple cell types.In this study,a strategy for constructing alveolar models based on degradable hydrogel microspheres is proposed.Hydrogel microspheres,200-250μm in diameter,were prepared using a self-developed printing technique driven by alternating viscous and inertial forces.Microcapsules were further constructed using a coacervation-based layer-by-layer technique and core liquefaction.Three types of cells were inoculated and co-cultured on hydrogel capsules based on optimized microcapsule surface treatment strategies.Finally,an in vitro three-dimensional endothelial alveolar model with a multicellular composition and vesicle-like structure with a diameter of approximately 230μm was successfully constructed.Cells in the constructed alveolar model maintained a high survival rate.The LD_(50)values of glutaraldehyde based on the constructed models were in good agreement with the reference values,validating the potential of the model for future toxicant and drug detection.