Oxygen and carbon dioxide sensors are involved in many chemical and biochemical reactions. Consequently, considerable efforts over years have been devoted to discover and improve suitable techniques for measuring gas ...Oxygen and carbon dioxide sensors are involved in many chemical and biochemical reactions. Consequently, considerable efforts over years have been devoted to discover and improve suitable techniques for measuring gas concentrations by optical fiber sensors. Optical gas sensors consist of a gas-sensitive dye entrapped in a matrix with a high permeability to gas. With such sensors, gas concentration is evaluated based upon the reduction in luminescence intensity caused by gas quenching of the emitting state. However, the luminescence quenching effect of oxygen is highly sensitive to temperature. Thus, a simple, low-cost plastic optical fiber sensor for dual sensing of temperature and oxygen is presented. Also, a modified Stern-Volmer model is introduced to compensate for the temperature drift while the temperature is obtained by above dual sensor. Recently, we presented highly-sensitive oxygen and dissolved oxygen sensors comprising an optical fiber coated at one end with platinum （II） meso-tetrakis（pentafluorophenyl）porphyrin （PtTFPP） and PtTFPP entrapped core-shell silica nanoparticles embedded in an n-octyltriethoxysilane（Octyl-triEOS）/tetraethylorthosilane （TEOS） composite xerogel. Also, two-dimensional gas measurement for the distribution of chemical parameters in non-homogeneous samples is developed and is of interest in medical and biological researches.展开更多
Current hemostatic agents or dressings are not efficient under extremely hot and cold environments due to deterioration of active ingredients,water evaporation and ice crystal growth.To address these challenges,we eng...Current hemostatic agents or dressings are not efficient under extremely hot and cold environments due to deterioration of active ingredients,water evaporation and ice crystal growth.To address these challenges,we engineered a biocompatible hemostatic system with thermoregulatory properties for harsh conditions by combining the asymmetric wetting nano-silica aerogel coated-gauze(AWNSA@G)with a layer-by-layer(LBL)structure.Our AWNSA@G was a dressing with a tunable wettability prepared by spraying the hydrophobic nano-silica aerogel onto the gauze from different distances.The hemostatic time and blood loss of the AWNSA@G were 5.1 and 6.9 times lower than normal gauze in rat’s injured femoral artery model.Moreover,the modified gauze was torn off after hemostasis without rebleeding,approximately 23.8 times of peak peeling force lower than normal gauze.For the LBL structure,consisting of the nano-silica aerogel layer and a n-octadecane phase change material layer,in both hot(70℃)and cold(-27℃)environments,exhibited dual-functional thermal management and maintained a stable internal temperature.We further verified our composite presented superior blood coagulation effect in extreme environments due to the LBL structure,the pro-coagulant properties of nano-silica aerogel and unidirectional fluid pumping of AWNSA@G.Our work,therefore,shows great hemostasis potential under normal and extreme temperature environments.展开更多
文摘Oxygen and carbon dioxide sensors are involved in many chemical and biochemical reactions. Consequently, considerable efforts over years have been devoted to discover and improve suitable techniques for measuring gas concentrations by optical fiber sensors. Optical gas sensors consist of a gas-sensitive dye entrapped in a matrix with a high permeability to gas. With such sensors, gas concentration is evaluated based upon the reduction in luminescence intensity caused by gas quenching of the emitting state. However, the luminescence quenching effect of oxygen is highly sensitive to temperature. Thus, a simple, low-cost plastic optical fiber sensor for dual sensing of temperature and oxygen is presented. Also, a modified Stern-Volmer model is introduced to compensate for the temperature drift while the temperature is obtained by above dual sensor. Recently, we presented highly-sensitive oxygen and dissolved oxygen sensors comprising an optical fiber coated at one end with platinum （II） meso-tetrakis（pentafluorophenyl）porphyrin （PtTFPP） and PtTFPP entrapped core-shell silica nanoparticles embedded in an n-octyltriethoxysilane（Octyl-triEOS）/tetraethylorthosilane （TEOS） composite xerogel. Also, two-dimensional gas measurement for the distribution of chemical parameters in non-homogeneous samples is developed and is of interest in medical and biological researches.
基金granted approval by the Animal Ethics Committee of Jiangnan University(Protocol JN.No 20220615S0801025).
文摘Current hemostatic agents or dressings are not efficient under extremely hot and cold environments due to deterioration of active ingredients,water evaporation and ice crystal growth.To address these challenges,we engineered a biocompatible hemostatic system with thermoregulatory properties for harsh conditions by combining the asymmetric wetting nano-silica aerogel coated-gauze(AWNSA@G)with a layer-by-layer(LBL)structure.Our AWNSA@G was a dressing with a tunable wettability prepared by spraying the hydrophobic nano-silica aerogel onto the gauze from different distances.The hemostatic time and blood loss of the AWNSA@G were 5.1 and 6.9 times lower than normal gauze in rat’s injured femoral artery model.Moreover,the modified gauze was torn off after hemostasis without rebleeding,approximately 23.8 times of peak peeling force lower than normal gauze.For the LBL structure,consisting of the nano-silica aerogel layer and a n-octadecane phase change material layer,in both hot(70℃)and cold(-27℃)environments,exhibited dual-functional thermal management and maintained a stable internal temperature.We further verified our composite presented superior blood coagulation effect in extreme environments due to the LBL structure,the pro-coagulant properties of nano-silica aerogel and unidirectional fluid pumping of AWNSA@G.Our work,therefore,shows great hemostasis potential under normal and extreme temperature environments.
