Identifying a device and detecting a change in its position is critical for secure devices management in the Internet of Things(IoT).In this paper,a device management system is proposed to track the devices by using a...Identifying a device and detecting a change in its position is critical for secure devices management in the Internet of Things(IoT).In this paper,a device management system is proposed to track the devices by using audio-based location distinction techniques.In the proposed scheme,traditional cryptographic techniques,such as symmetric encryption algorithm,RSA-based signcryption scheme,and audio-based secure transmission,are utilized to provide authentication,non-repudiation,and confidentiality in the information interaction of the management system.Moreover,an audio-based location distinction method is designed to detect the position change of the devices.Specifically,the audio frequency response(AFR)of several frequency points is utilized as a device signature.The device signature has the features as follows.(1)Hardware Signature:different pairs of speaker and microphone have different signatures;(2)Distance Signature:in the same direction,the signatures are different at different distances;and(3)Direction Signature:at the same distance,the signatures are different in different directions.Based on the features above,amovement detection algorithmfor device identification and location distinction is designed.Moreover,a secure communication protocol is also proposed by using traditional cryptographic techniques to provide integrity,authentication,and non-repudiation in the process of information interaction between devices,Access Points(APs),and Severs.Extensive experiments are conducted to evaluate the performance of the proposed method.The experimental results show that the proposedmethod has a good performance in accuracy and energy consumption.展开更多
With the rapid development of the Internet of Things(IoT),there are several challenges pertaining to security in IoT applications.Compared with the characteristics of the traditional Internet,the IoT has many problems...With the rapid development of the Internet of Things(IoT),there are several challenges pertaining to security in IoT applications.Compared with the characteristics of the traditional Internet,the IoT has many problems,such as large assets,complex and diverse structures,and lack of computing resources.Traditional network intrusion detection systems cannot meet the security needs of IoT applications.In view of this situation,this study applies cloud computing and machine learning to the intrusion detection system of IoT to improve detection performance.Usually,traditional intrusion detection algorithms require considerable time for training,and these intrusion detection algorithms are not suitable for cloud computing due to the limited computing power and storage capacity of cloud nodes;therefore,it is necessary to study intrusion detection algorithms with low weights,short training time,and high detection accuracy for deployment and application on cloud nodes.An appropriate classification algorithm is a primary factor for deploying cloud computing intrusion prevention systems and a prerequisite for the system to respond to intrusion and reduce intrusion threats.This paper discusses the problems related to IoT intrusion prevention in cloud computing environments.Based on the analysis of cloud computing security threats,this study extensively explores IoT intrusion detection,cloud node monitoring,and intrusion response in cloud computing environments by using cloud computing,an improved extreme learning machine,and other methods.We use the Multi-Feature Extraction Extreme Learning Machine(MFE-ELM)algorithm for cloud computing,which adds a multi-feature extraction process to cloud servers,and use the deployed MFE-ELM algorithm on cloud nodes to detect and discover network intrusions to cloud nodes.In our simulation experiments,a classical dataset for intrusion detection is selected as a test,and test steps such as data preprocessing,feature engineering,model training,and result analysis are performed.The experimental results show that the proposed algorithm can effectively detect and identify most network data packets with good model performance and achieve efficient intrusion detection for heterogeneous data of the IoT from cloud nodes.Furthermore,it can enable the cloud server to discover nodes with serious security threats in the cloud cluster in real time,so that further security protection measures can be taken to obtain the optimal intrusion response strategy for the cloud cluster.展开更多
Penpulimab is an anti-programmed cell death-1(PD-1)IgG1 antibody with no Fc gamma receptor(FcγR)binding activity,and thus theoretically reduced immune-related adverse events(irAEs)while maintaining efficacy.This sing...Penpulimab is an anti-programmed cell death-1(PD-1)IgG1 antibody with no Fc gamma receptor(FcγR)binding activity,and thus theoretically reduced immune-related adverse events(irAEs)while maintaining efficacy.This single-arm,phase II trial conducted across 20 tertiary care centers in China enrolled adult patients with metastatic nasopharyngeal carcinoma(NPC)who had failed two or more lines of previous systemic chemotherapy.Patients received 200-mg penpulimab intravenously every 2 weeks(4 weeks per cycle)until disease progression or intolerable toxicities.The primary endpoint was objective response rate(ORR)per RECIST(version 1.1),as assessed by an independent radiological review committee.The secondary endpoints included progression-free survival(PFS)and overall survival(OS).One hundred thirty patients were enrolled and 125 were efficacy evaluable.At the data cutoff date(September 28,2022),1 patient achieved complete response and 34 patients attained partial response.The ORR was 28.0%(95%CI 20.3–36.7%).The response was durable,with 66.8%still in response at 9 months.Thirty-three patients(26.4%)were still on treatment.The median PFS and OS were 3.6 months(95%CI=1.9–7.3 months)and 22.8 months(95%CI=17.1 months to not reached),respectively.Ten(7.6%)patients experienced grade 3 or higher irAEs.Penpulimab has promising anti-tumor activities and acceptable toxicities in heavily pretreated metastatic NPC patients,supporting further clinical development as third-line treatment of metastatic NPC.展开更多
Hollow semiconductor nanostructures with direct Z-scheme heterojunction have significant advantages for photocatalytic reactions,and optimizing the interfacial charge transmission of Z-scheme heterojunction is the hin...Hollow semiconductor nanostructures with direct Z-scheme heterojunction have significant advantages for photocatalytic reactions,and optimizing the interfacial charge transmission of Z-scheme heterojunction is the hinge to achieve excellent solar conversion efficiency.In this work,tubular Ni_(1−x)Co_(x)S_(2)-CdS heterostructures with reinforced Z-scheme charge transmission were constructed through an In-metal-organic framework(MOF)templated strategy.The Z-scheme charge transfer mechanism was sufficiently confirmed by combining density functional theory(DFT)calculation,X-ray photoelectron spectroscopy(XPS),surface photovoltage spectroscopy(SPV),and radical testing results.Crucially,the use of sodium citrate complexant contributes to the formation of intimate heterointerface,and the Fermi level gap between CdS and NiS_(2)is enlarged through Co doping into NiS_(2),which enhances the built-in electric field and photo-carriers transmission driving force for Ni_(1−x)Co_(x)S_(2)-CdS heterojunction,resulting in an evidently promoted activity toward H2 evolution reaction(HER).Under visible-light(λ>400 nm)irradiation,the Ni_(1−x)Co_(x)S_(2)-CdS composite with 10 mol%Co doping and 80 wt.%CdS(NC_(0.10)S-80%CdS)achieved an outstanding HER rate up to 35.94 mmol·g^(−1)·h^(−1)(corresponding to the apparent quantum efficiency of 34.7%at 420 nm),approximately 76.4 times that of 3 wt.%Pt-loaded CdS and it is much superior to that of most CdS-based photocatalysts ever reported.Moreover,the good photocatalytic durability of Ni_(1−x)Co_(x)S_(2)-CdS heterostructures was validated by cycling and long-term HER tests.This work could inspire the development of high-performance Z-scheme heterojunction via optimizing the morphology and interfacial charge transmission.展开更多
Developing low-cost and high-efficiency photocatalysts for hydrogen production from solar water splitting is intriguing but challenging. In this study, unique one-dimensional （1D） multi-node MoS2/CdS hetero-nanowir...Developing low-cost and high-efficiency photocatalysts for hydrogen production from solar water splitting is intriguing but challenging. In this study, unique one-dimensional （1D） multi-node MoS2/CdS hetero-nanowires （NWs） for efficient visible-light photocatalytic H2 evolution are synthesized via a facile hydrothermal method. Flower-like sheaths are assembled from numerous_ defect-rich O-incorporated {0001} MoS2 facet surrounded CdS NW stems are ultrathin nanosheets （NSs）, and {1120}- grown preferentially along the c-axis. Interestingly, the defects in the MoS2 NSs provide additional active S atoms on the exposed edge sites, and the incorporation of O reduces the energy barrier for H2 evolution and increases the electric conductivity of the MoS2 NSs. Moreover, the recombination of photoinduced charge carriers is significantly inhibited by the heterojunction formed between the MoS2 NSs and CdS NWs. Therefore, in the absence of noble metals as co-catalysts, the 1D MoS2 NS/CdS NW hybrids exhibit an excellent H2-generation rate of 10.85 mmol·g^-1·h^-1 and a quantum yield of 22.0% at ,λ = 475 nm, which is far better than those of Pt/CdS NWs, pure MoS2 NSs, and CdS NWs as well as their physical mixtures. Our results contribute to the rational construction of highly reactive nanostructures for various catalytic applications.展开更多
Construction of macro-materials with highly oriented microstructures and well-connected interfaces between building blocks is significant for a variety of applications. However, it is still challenging to confine the ...Construction of macro-materials with highly oriented microstructures and well-connected interfaces between building blocks is significant for a variety of applications. However, it is still challenging to confine the desired structures. Thus, well-defined building blocks would be crucial to address this issue. Herein, we present a facile process based on 1.8 nm Pd nanoclusters （NCs） to achieve centimeter-size assemblages with aligned honeycomb structures, where the diameter of a single tubular moiety is -4 μm. Layered and disordered porous assemblages were also obtained by modulating the temperature in this system. The reconciled interactions between the NCs were crucial to the assemblages. As a comparison, 14 nm Pd nanoparticles formed only aggregates. This work highlights the approach of confining the size of the building blocks in order to better control the assembly process and improve the stability of the structures.展开更多
A double-layer microfluidic chip integrated with a hollow fiber(HF)was developed to reconstitute the intestine-liver functionality for studying the absorption and metabolism of combination drugs.Caco-2 cells were inoc...A double-layer microfluidic chip integrated with a hollow fiber(HF)was developed to reconstitute the intestine-liver functionality for studying the absorption and metabolism of combination drugs.Caco-2 cells were inoculated in the HF cavity at the top of the serpentine channel to simulate the intestinal tissue for drug absorption and transport studied,and Hep G2 cells,seeded in the bottom chamber,were used to mimic the liver for metabolism-related studies.Genistein and dacarbazine were selected for combination drug therapy and its effects on cell viability,hepatotoxicity,and cell cycle arrest under drug-conditioned culture were investigated.The results suggested that the combined concentration below-100μg/m L had no significant inhibitory effect on Hep G2 cell viability,and therefore Hep G2 cells maintained their drug metabolism ability.When the drug concentration was increased above 250μg/m L,Hep G2 cells underwent apoptosis.Detection of metabolites by mass spectrometry proved the effective metabolism in the microchip model.This dynamic,co-culture microchip successfully provided a podium for long-term observation of absorption,transport,and metabolism of combination drugs,and could be an effective in vitro simulation model for further clinical research.展开更多
Artificial Z-scheme photocatalytic systems have received considerable attention in recent years because they can achieve wide light-absorption, high charge-separation efficiency, and strong redox ability simultaneousl...Artificial Z-scheme photocatalytic systems have received considerable attention in recent years because they can achieve wide light-absorption, high charge-separation efficiency, and strong redox ability simultaneously. Nevertheless, it is still challenging to exploit low-cost and stable Zscheme photocatalysts with highly-efficient H2 evolution from solar water-splitting so far. Herein, we report a novel all-solidstate Z-scheme photocatalyst Cd1-xZnxS@WO3-x consisting of Cd1-xZnxS nanorods coated with oxygen-deficient WO3-x amorphous layers. The Cd1-xZnxS@WO3-x exhibits an outstanding H2 evolution reaction(HER) activity as compared with Pt-loaded Cd1-xZnxS and most WO3- and Cd S-based photocatalysts, due to the generation of stronger reducing electrons through the appropriate Zn-doping in Cd1-xZnxS and the enhanced charge transfer by introducing oxygen vacancies(W^5+/OVs) into the ultrathin WO3-x amorphous coatings. The optimal HER rate of Cd1-xZnxS@WO3- xis determined to be 21.68 mmol h^-1 g^-1, which is further raised up to 28.25 mmol h^-1 g^-1(about 12 times more than that of Pt/Cd1-xZnxS) when Cd1-xZnxS@WO3-x is hybridized by Co Ox and Ni Oxdual cocatalysts(Cd1-xZnxS@WO3-x/CoOx/NiOx)through in-situ photo-deposition. Moreover, the corresponding apparent quantum yield(AQY) at 420 nm is significantly increased from 34.6% for Cd1-xZnxS@WO3-x to 60.8% for Cd1-xZnxS@WO3-x/CoOx/NiOx. In addition, both Cd1-xZnxS@WO3-x and Cd1-xZnxS@WO3-x/CoOx/NiOx demonstrate good stability towards HER. The results displayed in this work will inspire the rational design and synthesis of high-performance nanostructures for photocatalytic applications.展开更多
Photocatalytic water splitting for hydrogen(H_(2))production is a green sustainable technology,in which highly-efficient steady photocatalysts are fundamentally required.In this work,unique CdS/Cd_(0.5)Zn_(0.5)S-M0_(1...Photocatalytic water splitting for hydrogen(H_(2))production is a green sustainable technology,in which highly-efficient steady photocatalysts are fundamentally required.In this work,unique CdS/Cd_(0.5)Zn_(0.5)S-M0_(1-x)W_(x)S_(2) photocatalyst constructed by CdS hollow nano-spheres with successively surface-modified Cd_(0.5)Zn_(0.5)S shell and defect-rich MO_(1-x)W_(x)S_(2) ultrathin nanosheets was reported for the first time.Interestingly,the Cd_(0.5)Zn_(0.5)S shell could greatly enhance the photo-stability and reduce the carrier recombination of CdS.Meanwhile,enriching active sites and accelerating charge transfer could be achieved via anchoring defect-rich Mo_(1-x)W_(x)S_(2) onto CdS/Cd_(0.5)Zn_(0.5)S hollow heterostructures.Specifically,the optimized CdS/Cd_(0.5)Zn_(0.5)S-Mo_(1-x)W_(x)Sa(6 h Cd_(0.5)Zn_(0.5)S-coating,7 wt.%Mo_(1-x)W_(x)S_(2),x=0.5)hybrid delivered an exceptional H_(2) generation rate of 215.99 mmol·g^(-1)·h^(-1),which is approximately 502,134,and 23 times that of pure CdS,CdS/Cd_(0.5)Zn_(0.5)S,and 3 wt.%Pt-loaded CdS/Cd_(0.5)Zn_(0.5)S,respectively.Remarkably,a high H_(2) evolution reaction(HER)apparent quantum yield(AQY)of 64.81%was obtained under 420-nm irradiation.In addition,the CdS/Cd_(0.5)Zn_(0.5)S-Mo_(1-x)W_(x)S_(2) was also durable for H2 production under long-term irradiation.This work provides valuable inspirations to rational design and synthesis of efficient and stable hybrid photocatalysts for solar energy conversion.展开更多
Membrane tension plays a significant role in many cellular processes including cell adhesion, migration and spreading. Despite the importance of membrane tension, it remains difficult to measure in vivo. Recently, the...Membrane tension plays a significant role in many cellular processes including cell adhesion, migration and spreading. Despite the importance of membrane tension, it remains difficult to measure in vivo. Recently, the development of non-invasive fluorescent probes have made great progress, especially excitedstate deplanarization in molecular rotors has been applied to image membrane tension in living cells.Nevertheless, an intrinsic limitation of such kind of probe is that they depend on the lipid packing, and how the lipid packing responds to the membrane tension change remains unclear. Therefore, in this work,we used a polarity-sensitive membrane probe to investigate the possible response mechanism of lipid packing to the change of membrane tension that was regulated by osmotic shocks. The results showed that an increase in membrane tension could stretch the lipids apart with large displacements, and this change was not homogeneous on the whole membrane, instead, increase of membrane tension induced phase separation.展开更多
基金This work is supported by Demonstration of Scientific and Technology Achievements Transform in Sichuan Province under Grant 2022ZHCG0036National Natural Science Foundation of China(62002047).
文摘Identifying a device and detecting a change in its position is critical for secure devices management in the Internet of Things(IoT).In this paper,a device management system is proposed to track the devices by using audio-based location distinction techniques.In the proposed scheme,traditional cryptographic techniques,such as symmetric encryption algorithm,RSA-based signcryption scheme,and audio-based secure transmission,are utilized to provide authentication,non-repudiation,and confidentiality in the information interaction of the management system.Moreover,an audio-based location distinction method is designed to detect the position change of the devices.Specifically,the audio frequency response(AFR)of several frequency points is utilized as a device signature.The device signature has the features as follows.(1)Hardware Signature:different pairs of speaker and microphone have different signatures;(2)Distance Signature:in the same direction,the signatures are different at different distances;and(3)Direction Signature:at the same distance,the signatures are different in different directions.Based on the features above,amovement detection algorithmfor device identification and location distinction is designed.Moreover,a secure communication protocol is also proposed by using traditional cryptographic techniques to provide integrity,authentication,and non-repudiation in the process of information interaction between devices,Access Points(APs),and Severs.Extensive experiments are conducted to evaluate the performance of the proposed method.The experimental results show that the proposedmethod has a good performance in accuracy and energy consumption.
基金funded by the Key Research and Development plan of Jiangsu Province (Social Development)No.BE20217162Jiangsu Modern Agricultural Machinery Equipment and Technology Demonstration and Promotion Project No.NJ2021-19.
文摘With the rapid development of the Internet of Things(IoT),there are several challenges pertaining to security in IoT applications.Compared with the characteristics of the traditional Internet,the IoT has many problems,such as large assets,complex and diverse structures,and lack of computing resources.Traditional network intrusion detection systems cannot meet the security needs of IoT applications.In view of this situation,this study applies cloud computing and machine learning to the intrusion detection system of IoT to improve detection performance.Usually,traditional intrusion detection algorithms require considerable time for training,and these intrusion detection algorithms are not suitable for cloud computing due to the limited computing power and storage capacity of cloud nodes;therefore,it is necessary to study intrusion detection algorithms with low weights,short training time,and high detection accuracy for deployment and application on cloud nodes.An appropriate classification algorithm is a primary factor for deploying cloud computing intrusion prevention systems and a prerequisite for the system to respond to intrusion and reduce intrusion threats.This paper discusses the problems related to IoT intrusion prevention in cloud computing environments.Based on the analysis of cloud computing security threats,this study extensively explores IoT intrusion detection,cloud node monitoring,and intrusion response in cloud computing environments by using cloud computing,an improved extreme learning machine,and other methods.We use the Multi-Feature Extraction Extreme Learning Machine(MFE-ELM)algorithm for cloud computing,which adds a multi-feature extraction process to cloud servers,and use the deployed MFE-ELM algorithm on cloud nodes to detect and discover network intrusions to cloud nodes.In our simulation experiments,a classical dataset for intrusion detection is selected as a test,and test steps such as data preprocessing,feature engineering,model training,and result analysis are performed.The experimental results show that the proposed algorithm can effectively detect and identify most network data packets with good model performance and achieve efficient intrusion detection for heterogeneous data of the IoT from cloud nodes.Furthermore,it can enable the cloud server to discover nodes with serious security threats in the cloud cluster in real time,so that further security protection measures can be taken to obtain the optimal intrusion response strategy for the cloud cluster.
文摘Penpulimab is an anti-programmed cell death-1(PD-1)IgG1 antibody with no Fc gamma receptor(FcγR)binding activity,and thus theoretically reduced immune-related adverse events(irAEs)while maintaining efficacy.This single-arm,phase II trial conducted across 20 tertiary care centers in China enrolled adult patients with metastatic nasopharyngeal carcinoma(NPC)who had failed two or more lines of previous systemic chemotherapy.Patients received 200-mg penpulimab intravenously every 2 weeks(4 weeks per cycle)until disease progression or intolerable toxicities.The primary endpoint was objective response rate(ORR)per RECIST(version 1.1),as assessed by an independent radiological review committee.The secondary endpoints included progression-free survival(PFS)and overall survival(OS).One hundred thirty patients were enrolled and 125 were efficacy evaluable.At the data cutoff date(September 28,2022),1 patient achieved complete response and 34 patients attained partial response.The ORR was 28.0%(95%CI 20.3–36.7%).The response was durable,with 66.8%still in response at 9 months.Thirty-three patients(26.4%)were still on treatment.The median PFS and OS were 3.6 months(95%CI=1.9–7.3 months)and 22.8 months(95%CI=17.1 months to not reached),respectively.Ten(7.6%)patients experienced grade 3 or higher irAEs.Penpulimab has promising anti-tumor activities and acceptable toxicities in heavily pretreated metastatic NPC patients,supporting further clinical development as third-line treatment of metastatic NPC.
基金supported by the National Natural Science Foundation of China(Nos.22179068,52272222,52072197,and 52171140)the 111 Project of China(No.D20017)+5 种基金the Natural Science Foundation of Shandong Province(No.ZR2019JQ14)the Major Scientific and Technological Innovation Project of Shandong Province(No.2019JZZY020405)the Key Research and Development Program of Jiangsu Province(No.BE2021070)the Scientific and Technological Innovation Promotion Project for Small-medium Enterprises of Shandong Province(No.2022TSGC1257)the Shandong Province“Double-Hundred Talent Plan”(Nos.WST2019011,WST2020003,and WST2021021)the Major Research Program of Jining City(No.2020ZDZP024).
文摘Hollow semiconductor nanostructures with direct Z-scheme heterojunction have significant advantages for photocatalytic reactions,and optimizing the interfacial charge transmission of Z-scheme heterojunction is the hinge to achieve excellent solar conversion efficiency.In this work,tubular Ni_(1−x)Co_(x)S_(2)-CdS heterostructures with reinforced Z-scheme charge transmission were constructed through an In-metal-organic framework(MOF)templated strategy.The Z-scheme charge transfer mechanism was sufficiently confirmed by combining density functional theory(DFT)calculation,X-ray photoelectron spectroscopy(XPS),surface photovoltage spectroscopy(SPV),and radical testing results.Crucially,the use of sodium citrate complexant contributes to the formation of intimate heterointerface,and the Fermi level gap between CdS and NiS_(2)is enlarged through Co doping into NiS_(2),which enhances the built-in electric field and photo-carriers transmission driving force for Ni_(1−x)Co_(x)S_(2)-CdS heterojunction,resulting in an evidently promoted activity toward H2 evolution reaction(HER).Under visible-light(λ>400 nm)irradiation,the Ni_(1−x)Co_(x)S_(2)-CdS composite with 10 mol%Co doping and 80 wt.%CdS(NC_(0.10)S-80%CdS)achieved an outstanding HER rate up to 35.94 mmol·g^(−1)·h^(−1)(corresponding to the apparent quantum efficiency of 34.7%at 420 nm),approximately 76.4 times that of 3 wt.%Pt-loaded CdS and it is much superior to that of most CdS-based photocatalysts ever reported.Moreover,the good photocatalytic durability of Ni_(1−x)Co_(x)S_(2)-CdS heterostructures was validated by cycling and long-term HER tests.This work could inspire the development of high-performance Z-scheme heterojunction via optimizing the morphology and interfacial charge transmission.
基金Acknowledgements This work was supported by the National Natural Science Foundation of China （Nos. 21431003 and 21521091） and China Ministry of Science and Technology （No. 2016YFA0202801）. We also thank Dr. Lina Zhang and Ms. Xiaohua Gu for their kind help with the TEM measurements.
文摘Developing low-cost and high-efficiency photocatalysts for hydrogen production from solar water splitting is intriguing but challenging. In this study, unique one-dimensional （1D） multi-node MoS2/CdS hetero-nanowires （NWs） for efficient visible-light photocatalytic H2 evolution are synthesized via a facile hydrothermal method. Flower-like sheaths are assembled from numerous_ defect-rich O-incorporated {0001} MoS2 facet surrounded CdS NW stems are ultrathin nanosheets （NSs）, and {1120}- grown preferentially along the c-axis. Interestingly, the defects in the MoS2 NSs provide additional active S atoms on the exposed edge sites, and the incorporation of O reduces the energy barrier for H2 evolution and increases the electric conductivity of the MoS2 NSs. Moreover, the recombination of photoinduced charge carriers is significantly inhibited by the heterojunction formed between the MoS2 NSs and CdS NWs. Therefore, in the absence of noble metals as co-catalysts, the 1D MoS2 NS/CdS NW hybrids exhibit an excellent H2-generation rate of 10.85 mmol·g^-1·h^-1 and a quantum yield of 22.0% at ,λ = 475 nm, which is far better than those of Pt/CdS NWs, pure MoS2 NSs, and CdS NWs as well as their physical mixtures. Our results contribute to the rational construction of highly reactive nanostructures for various catalytic applications.
文摘Construction of macro-materials with highly oriented microstructures and well-connected interfaces between building blocks is significant for a variety of applications. However, it is still challenging to confine the desired structures. Thus, well-defined building blocks would be crucial to address this issue. Herein, we present a facile process based on 1.8 nm Pd nanoclusters （NCs） to achieve centimeter-size assemblages with aligned honeycomb structures, where the diameter of a single tubular moiety is -4 μm. Layered and disordered porous assemblages were also obtained by modulating the temperature in this system. The reconciled interactions between the NCs were crucial to the assemblages. As a comparison, 14 nm Pd nanoparticles formed only aggregates. This work highlights the approach of confining the size of the building blocks in order to better control the assembly process and improve the stability of the structures.
基金supported by the National Natural Science Foundation of China (81373373, 21435002, 21621003)
文摘A double-layer microfluidic chip integrated with a hollow fiber(HF)was developed to reconstitute the intestine-liver functionality for studying the absorption and metabolism of combination drugs.Caco-2 cells were inoculated in the HF cavity at the top of the serpentine channel to simulate the intestinal tissue for drug absorption and transport studied,and Hep G2 cells,seeded in the bottom chamber,were used to mimic the liver for metabolism-related studies.Genistein and dacarbazine were selected for combination drug therapy and its effects on cell viability,hepatotoxicity,and cell cycle arrest under drug-conditioned culture were investigated.The results suggested that the combined concentration below-100μg/m L had no significant inhibitory effect on Hep G2 cell viability,and therefore Hep G2 cells maintained their drug metabolism ability.When the drug concentration was increased above 250μg/m L,Hep G2 cells underwent apoptosis.Detection of metabolites by mass spectrometry proved the effective metabolism in the microchip model.This dynamic,co-culture microchip successfully provided a podium for long-term observation of absorption,transport,and metabolism of combination drugs,and could be an effective in vitro simulation model for further clinical research.
基金financially supported by the National Natural Science Foundation of China (51572136, 51772162, 21571112, 51802170 and 21801150)the Natural Science Foundation of Shandong Province (ZR2018BEM014, ZR2018LB008 andZR2019MB001)+2 种基金Taishan Scholar Foundation of Shandong Province (H. W., ts201712047)the Special Fund Project to Guide Development of Local Science and Technology by Central Government (H.W.)Taishan Scholar Program of Advantage and Characteristic Discipline Team of Eco Chemical Process and Technology
文摘Artificial Z-scheme photocatalytic systems have received considerable attention in recent years because they can achieve wide light-absorption, high charge-separation efficiency, and strong redox ability simultaneously. Nevertheless, it is still challenging to exploit low-cost and stable Zscheme photocatalysts with highly-efficient H2 evolution from solar water-splitting so far. Herein, we report a novel all-solidstate Z-scheme photocatalyst Cd1-xZnxS@WO3-x consisting of Cd1-xZnxS nanorods coated with oxygen-deficient WO3-x amorphous layers. The Cd1-xZnxS@WO3-x exhibits an outstanding H2 evolution reaction(HER) activity as compared with Pt-loaded Cd1-xZnxS and most WO3- and Cd S-based photocatalysts, due to the generation of stronger reducing electrons through the appropriate Zn-doping in Cd1-xZnxS and the enhanced charge transfer by introducing oxygen vacancies(W^5+/OVs) into the ultrathin WO3-x amorphous coatings. The optimal HER rate of Cd1-xZnxS@WO3- xis determined to be 21.68 mmol h^-1 g^-1, which is further raised up to 28.25 mmol h^-1 g^-1(about 12 times more than that of Pt/Cd1-xZnxS) when Cd1-xZnxS@WO3-x is hybridized by Co Ox and Ni Oxdual cocatalysts(Cd1-xZnxS@WO3-x/CoOx/NiOx)through in-situ photo-deposition. Moreover, the corresponding apparent quantum yield(AQY) at 420 nm is significantly increased from 34.6% for Cd1-xZnxS@WO3-x to 60.8% for Cd1-xZnxS@WO3-x/CoOx/NiOx. In addition, both Cd1-xZnxS@WO3-x and Cd1-xZnxS@WO3-x/CoOx/NiOx demonstrate good stability towards HER. The results displayed in this work will inspire the rational design and synthesis of high-performance nanostructures for photocatalytic applications.
基金support from the National Natural Science Foundation of China(Nos.51802170,51772162,and 21801150)the Natural Science Foundation of Shandong Province(Nos.ZR2019MB001,ZR2018BEM014,and ZR2019JQ14)+3 种基金the Youth Innovation and Technology Foundation of Shandong Higher Education Institutions,China(No.2019KJC004)the Taishan Scholar Project of Shandong Province(No.ts201712047)the Special Fund Project to Guide Development of Local Science and Technology by Central Government,the Open Research Fund of State Key Laboratory of Inorganic Synthesis and Preparative Chemistry of Jilin University(No.2019-22)the Taishan Scholar Program of Advantage and Characteristic Discipline Team of Eco-Chemical Process and Technology.
文摘Photocatalytic water splitting for hydrogen(H_(2))production is a green sustainable technology,in which highly-efficient steady photocatalysts are fundamentally required.In this work,unique CdS/Cd_(0.5)Zn_(0.5)S-M0_(1-x)W_(x)S_(2) photocatalyst constructed by CdS hollow nano-spheres with successively surface-modified Cd_(0.5)Zn_(0.5)S shell and defect-rich MO_(1-x)W_(x)S_(2) ultrathin nanosheets was reported for the first time.Interestingly,the Cd_(0.5)Zn_(0.5)S shell could greatly enhance the photo-stability and reduce the carrier recombination of CdS.Meanwhile,enriching active sites and accelerating charge transfer could be achieved via anchoring defect-rich Mo_(1-x)W_(x)S_(2) onto CdS/Cd_(0.5)Zn_(0.5)S hollow heterostructures.Specifically,the optimized CdS/Cd_(0.5)Zn_(0.5)S-Mo_(1-x)W_(x)Sa(6 h Cd_(0.5)Zn_(0.5)S-coating,7 wt.%Mo_(1-x)W_(x)S_(2),x=0.5)hybrid delivered an exceptional H_(2) generation rate of 215.99 mmol·g^(-1)·h^(-1),which is approximately 502,134,and 23 times that of pure CdS,CdS/Cd_(0.5)Zn_(0.5)S,and 3 wt.%Pt-loaded CdS/Cd_(0.5)Zn_(0.5)S,respectively.Remarkably,a high H_(2) evolution reaction(HER)apparent quantum yield(AQY)of 64.81%was obtained under 420-nm irradiation.In addition,the CdS/Cd_(0.5)Zn_(0.5)S-Mo_(1-x)W_(x)S_(2) was also durable for H2 production under long-term irradiation.This work provides valuable inspirations to rational design and synthesis of efficient and stable hybrid photocatalysts for solar energy conversion.
基金financially supported by Research and Development Program in Key Areas of Guangdong Province,China (No.2019B020209009)National Natural Science Foundation of China(Nos. 21727814, 22034005, 81872829)the China Postdoctoral Science Foundation (No. 2020M680502)。
文摘Membrane tension plays a significant role in many cellular processes including cell adhesion, migration and spreading. Despite the importance of membrane tension, it remains difficult to measure in vivo. Recently, the development of non-invasive fluorescent probes have made great progress, especially excitedstate deplanarization in molecular rotors has been applied to image membrane tension in living cells.Nevertheless, an intrinsic limitation of such kind of probe is that they depend on the lipid packing, and how the lipid packing responds to the membrane tension change remains unclear. Therefore, in this work,we used a polarity-sensitive membrane probe to investigate the possible response mechanism of lipid packing to the change of membrane tension that was regulated by osmotic shocks. The results showed that an increase in membrane tension could stretch the lipids apart with large displacements, and this change was not homogeneous on the whole membrane, instead, increase of membrane tension induced phase separation.
