POU transcription factor OCT4 not only plays an essential role in maintaining the pluripotent and self-renewing state of embryonic stem （ES） cells but also acts as a cell fate determinant through a gene dosage effec...POU transcription factor OCT4 not only plays an essential role in maintaining the pluripotent and self-renewing state of embryonic stem （ES） cells but also acts as a cell fate determinant through a gene dosage effect. However, the molecular mechanisms that control the intracellular OCT4 protein level remain elusive. Here, we report that human WWP2, an E3 ubiquitin （Ub）-protein ligase, interacts with OCT4 specifically through its WW domain and enhances Ub modification of OCT4 both in vitro and in vivo. We first demonstrated that endogenous OCT4 in hu- man ES cells can be post-translationally modified by Ub. Furthermore, we found that WWP2 promoted degradation of OCT4 through the 26S proteasome in a dosage-dependent manner, and the active site cysteine residue of WWP2 was required for both its enzymatic activity and proteolytic effect on OCT4. Remarkably, our data show that the en- dogenous OCT4 protein level was significantly elevated when WWP2 expression was downregulated by specific RNA interference （RNAi）, suggesting that WWP2 is an important regulator for maintaining a proper OCT4 protein level in human ES cells. Moreover, northern blot analysis showed that the WWP2 transcript was widely present in diverse human tissues/organs and highly expressed in undifferentiated human ES cells. However, its expression level was quickly decreased after human ES cells differentiated, indicating that WWP2 expression might be developmentally regulated. Our findings demonstrate that WWP2 is an important regulator of the OCT4 protein level in human ES cells.展开更多
This paper brings the comparison of performances of CO_(2)conversion by plasma and plasma-assisted catalysis based on the data collected from literature in this field,organised in an open access online database.This t...This paper brings the comparison of performances of CO_(2)conversion by plasma and plasma-assisted catalysis based on the data collected from literature in this field,organised in an open access online database.This tool is open to all users to carry out their own analyses,but also to contributors who wish to add their data to the database in order to improve the relevance of the comparisons made,and ultimately to improve the efficiency of CO_(2)conversion by plasma-catalysis.The creation of this database and database user interface is motivated by the fact that plasma-catalysis is a fast-growing field for all CO_(2)conversion processes,be it methanation,dry reforming of methane,methanolisation,or others.As a result of this rapid increase,there is a need for a set of standard procedures to rigorously compare performances of different systems.However,this is currently not possible because the fundamental mechanisms of plasma-catalysis are still too poorly understood to define these standard procedures.Fortunately however,the accumulated data within the CO_(2)plasma-catalysis community has become large enough to warrant so-called“big data”studies more familiar in the fields of medicine and the social sciences.To enable comparisons between multiple data sets and make future research more effective,this work proposes the first database on CO_(2)conversion performances by plasma-catalysis open to the whole community.This database has been initiated in the framework of a H_(2)0_(2)0 European project and is called the“PIONEER Data Base”.The database gathers a large amount of CO_(2)conversion performance data such as conversion rate,energy efficiency,and selectivity for numerous plasma sources coupled with or without a catalyst.Each data set is associated with metadata describing the gas mixture,the plasma source,the nature of the catalyst,and the form of coupling with the plasma.Beyond the database itself,a data extraction tool with direct visualisation features or advanced filtering functionalities has been dev展开更多
Acupuncture has been experimentally proved to be capable of exciting various groups of fibres. However, opinions differ as to which group of fibres is mainly responsible for conveying analgesic impulses. While some co...Acupuncture has been experimentally proved to be capable of exciting various groups of fibres. However, opinions differ as to which group of fibres is mainly responsible for conveying analgesic impulses. While some consider that large-sized fibres are concerned with analgesia, others maintain that the engagement of Group Ⅲ fibres will produce better analgesic effect. As for the role played by Group Ⅳ fibres in the effect of analgesia, some authors take a negative attitude, being void of sufficient evidence.展开更多
S. R. Capps first gave the name rock glacier on the geologic map of the United States tes in 1910. It is a tongue-like or leaf-like accumulation commonly formed by massive gravels in periglacier regions and distribute...S. R. Capps first gave the name rock glacier on the geologic map of the United States tes in 1910. It is a tongue-like or leaf-like accumulation commonly formed by massive gravels in periglacier regions and distributed mainly on medium- and high-latitude high mountains. The genesis and form of the rock glacier are rather complicated, and differ-展开更多
Human LAK cells were prepared by culturing normal human peripheral blood mononuclear cells (PBMC) with or without rIL-2 and assayed for T cell surface markers as well as anti-tumor activity against PC in vitro and in ...Human LAK cells were prepared by culturing normal human peripheral blood mononuclear cells (PBMC) with or without rIL-2 and assayed for T cell surface markers as well as anti-tumor activity against PC in vitro and in nude mice. Although the percentages of T3, T4, and T8 positive cells in rIL-2-activated cells did not differ significantly from those of control cells in vitro, the former showed stronger cytotoxicity than control cells to PG tumor cells in vitro. In vivo, LAK cells completely inhibited the growth of PG tumor in nude mice, whereas PBMC control cells were to be of no effect. The anti-tumor effect of human LAK cells in nude mice may offer a useful model to study the role of human LAK cells against human tumor in vivo.展开更多
Objective: To investigate the potential of superparamagnetic iron oxide particles (SPIO) in MR imaging for the differentiation between hyperplastic and metastatic lymph node. Methods: Animal models of malignant lymph ...Objective: To investigate the potential of superparamagnetic iron oxide particles (SPIO) in MR imaging for the differentiation between hyperplastic and metastatic lymph node. Methods: Animal models of malignant lymph node metastasis were established in 6 New-Zealand rabbits by a unilateral intra-muscular injection of VX2 carcinoma cells, and models of hyperplastic lymph nodes were induced in another 6 rabbits by a unilateral intra-muscular injection of egg yolk emulsion. MR images of the lymph nodes were obtained before and 12 h after interstitial injection of SPIO. Image results were analyzed and compared with pathological findings. Results: On unenhanced images, the signal intensity of hyperplastic and metastatic lymph nodes did not differ significantly. After administration of SPIO, the signal intensity of both hyperplastic and metastatic lymph nodes remained unchanged on T1-weighted SE images. On T2-weighted SE images, the signal intensity of hyperplastic lymph nodes decreased heterogeneously, while that of all metastatic ones remained unchanged. On T2-weighted GRE images, the signal intensity of hyperplastic lymph nodes decreased significantly and homogeneously, while that of 4 metastatic ones remained unchanged and that of the rest 2 decreased heterogeneously. Conclusion: SPIO-enhanced MR imaging may enable the differentiation between the hyperplastic and metastatic lymph nodes.展开更多
The density of dendritic cells (DC) and macro-phages (Mφ) in tissue specimens of gastric carcinoma (GC n=65) was investigated by ABC im-munohistochemical method using anti-S100 protein and anti-lysozyme antibodies, a...The density of dendritic cells (DC) and macro-phages (Mφ) in tissue specimens of gastric carcinoma (GC n=65) was investigated by ABC im-munohistochemical method using anti-S100 protein and anti-lysozyme antibodies, and was compared with that in gastric ulcer (GU n=19), chronic atrophic gastritis (CAG n=28) and normal gastric mucosa (NGM n=15). The mean density if DC (cells/mm2) in GC (15.0 was significantly higher than that in NGM (3.8) and GU (8.3), but was remarkably lower when compared to that in CAG (29.5) (P<0.01). Statistically significant difference in the population density of DC was observed between well- and poorly-differentiated GC (P<0.01). With their unique dendritic processes, DC were mainly concentrated within dense lymphoid infiltrates or in the T-area of reactive lymphoid follicles and were interspersed among the tumor cells. In contrast, Mφ were present around the necrotic foci and were rarely seen within the non-necrotic neoplastic tissues. These data suggest that DC, which differ in morphology, distribution, number and function form Mφ may be more directly involved in the host immune reaction against tumor by acting as antigen presenting cells.展开更多
The effect of temperature and hydrogen addition on undesired carbonaceous deposit formation during methane coupling was studied in DBD-plasma catalytic-wall reactors with Pd/Al2 O3, using electrical power to drive the...The effect of temperature and hydrogen addition on undesired carbonaceous deposit formation during methane coupling was studied in DBD-plasma catalytic-wall reactors with Pd/Al2 O3, using electrical power to drive the reaction.Experiments with thin catalyst layers allowed comparison of the performance of empty reactors and catalytic wall reactors without significantly influencing the plasma properties.The product distribution varies strongly in the temperature window between 25 and 200℃Minimal formation of deposits is found at an optimal temperature around 75℃ in the catalytic-wall reactors.The selectivity to deposits was c.a.10% with only 9 mg of catalyst loading instead of 45% in the blank reactor,while decreasing methane conversion only mildly.Co-feeding H2 to an empty reactor causes a similar decrease in selectivity to deposits,but in this case methane conversion also decreased significantly.Suppression of deposits formation in the catalytic-wall reactor at 75℃ is due to catalytic hydrogenation of mainly acetylene to ethylene.In the empty reactor,H2 co-feed decreases conversion but does not change the product distribution.The catalytic-wall reactors can be regenerated with H2-plasma at room temperature,which produces more added-value hydrocarbons.展开更多
173 simultaneous determinations of serum copper levels (SCL), serum zinc levels (SZL) and copper/zinc ratio (CZR) were made by atomic absorption spectrophotometry in 51 previously untreated lymphoma patients. SCL and ...173 simultaneous determinations of serum copper levels (SCL), serum zinc levels (SZL) and copper/zinc ratio (CZR) were made by atomic absorption spectrophotometry in 51 previously untreated lymphoma patients. SCL and CZR were significantly higher in patients before treatment (mean value 22.97 μmol/L, 1.55, respectively) and in those who did not reach complete remission (mean 21.21 μmol/L, 1.36) as compared with the patients in complete remission (mean 16.36 μmol/L, 1.06) or normal controls (mean 15.67 μmol/L, 0.98). The mean value of SCL and CZR of patients in complete remission did not differ significantly from those of normal controls. Patients in stages HI and IV had higher SCL and CZR (mean 25.15 μmol/L, 1.79) than those in stage Ⅰ and Ⅱ (mean 19.30 μmol/L, 1.16). No significant difference in SZL was observed between the patient groups and normal controls. Thus, SCL and CZR may be used as prognostic indicators for monitoring disease activity and response to therapy in malignant lymphoma.展开更多
Light absorption and scattering of plasmonic metal nanoparticles can lead to non-equilibrium charge carriers,intense electromagnetic near-fields,and heat generation,with promising applications in a vast range of field...Light absorption and scattering of plasmonic metal nanoparticles can lead to non-equilibrium charge carriers,intense electromagnetic near-fields,and heat generation,with promising applications in a vast range of fields,from chemical and physical sensing to nanomedicine and photocatalysis for the sustainable production of fuels and chemicals.Disentangling the relative contribution of thermal and non-thermal contributions in plasmon-driven processes is,however,difficult.Nanoscale temperature measurements are technically challenging,and macroscale experiments are often characterized by collective heating effects,which tend to make the actual temperature increase unpredictable.This work is intended to help the reader experimentally detect and quantify photothermal effects in plasmon-driven chemical reactions,to discriminate their contribution from that due to photochemical processes and to cast a critical eye on the current literature.To this aim,we review,and in some cases propose,seven simple experimental procedures that do not require the use of complex or expensive thermal microscopy techniques.These proposed procedures are adaptable to a wide range of experiments and fields of research where photothermal effects need to be assessed,such as plasmonic-assisted chemistry,heterogeneous catalysis,photovoltaics,biosensing,and enhanced molecular spectroscopy.展开更多
Electrocatalytic and plasma-activated processes receive increasing attention in catalysis. Density functional theory(DFT) calculations are state-of-the-art tools for the fundamental study of reaction mechanisms and pr...Electrocatalytic and plasma-activated processes receive increasing attention in catalysis. Density functional theory(DFT) calculations are state-of-the-art tools for the fundamental study of reaction mechanisms and predicting the performance of catalytic materials. Proper application of DFT-based methods is crucial when investigating charge-doped electrode surfaces during electrocatalytic and plasma-activated reactions. Here, as a model electrode for plasma-activated CO2 splitting, we studied the interactions of O, CO, and CO2 with the neutral and progressively charged Ag(111) metal surfaces. We show that the application of correction procedures is necessary to obtain accurate adsorption energy profiles of O atoms,CO and CO2 molecules on Ag surfaces that are under the influence of additional electrons. Interestingly,the oxidation of CO is found to shift from a Langmuir–Hinshelwood mechanism on a neutral electrode to an Eley–Rideal mechanism on charged electrodes. Furthermore, we show that the surface charging of Ag(111) electrodes increase their CO2 reduction performance by enhancing the adsorption of O atoms and desorption of CO molecules. A further increase in the absolute charge-state of the electrode surface is expected to waive the thermodynamic barriers for the CO2 splitting reaction.展开更多
In recent years,artificial intelligence(AI)methods have prominently proven their use in solving complex problems.Across science and engineering disciplines,the data-driven approach has become the fourth and newest par...In recent years,artificial intelligence(AI)methods have prominently proven their use in solving complex problems.Across science and engineering disciplines,the data-driven approach has become the fourth and newest paradigm.It is the burgeoning of findable,accessible,interoperable,and reusable(FAIR)data generated by the first three paradigms of experiment,theory,and simulation that has enabled the application of AI methods for the scientific discovery and engineering of compounds and materials.Here,we introduce a recipe for a data-driven strategy to speed up the virtual screening of two-dimensional(2D)materials and to accelerate the discovery of new candidates with targeted physical and chemical properties.As a proof of concept,we generate new 2D candidate materials covering an extremely large compositional space,downselect 316,505 likely stable 2D materials,and predict the key physical properties of these new 2D candidates.Finally,we hone in on the most propitious candidates of functional 2D materials for energy conversion and storage.展开更多
Silicon nanocrystals(SiNCs)have great potential to become environmental friendly alternatives to heavy-metal containing nanocrystals for applications including medical imaging,lighting and displays.SiNCs exhibit excel...Silicon nanocrystals(SiNCs)have great potential to become environmental friendly alternatives to heavy-metal containing nanocrystals for applications including medical imaging,lighting and displays.SiNCs exhibit excellent photostability,non-toxicity and abundant resources,but their often reported inefficient and spectrally limited light emission seriously impair their applications.Here we demonstrate a new method that converts SiNCs into an efficient and robust multi-chromatic phosphor.Using~15 keV electron-beam irradiation of oxide-capped SiNCs,we introduce several types of color centers into the nanocrystal’s oxide shell with efficient blue,green and red emission bands,together yielding warm-white photoluminescence,even for a single SiNC.Introduced centers are not native to the original system and we relate them to known defects in silica.Unlike in the silica host,however,here the centers are efficiently optically excitable.Provided further optimization and up-scaling of this method,e-beam irradiated SiNCs can be of great interest as white phosphors for applications such as LEDs.展开更多
基金Acknowledgments We are grateful to Dr DA Melton （Harvard University） for shar- ing his human ES cells with us. The study was supported by grants from the National High Technology Research and Development Program of China （2006CB943900）, the National Natural Science Foundation of China （General Program, 30500088）, the Shang- hai Jiao Tong University School of Medicine, and the Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences. The study was also supported by the Shanghai Leading Academic Deciline Project （S30201）.
文摘POU transcription factor OCT4 not only plays an essential role in maintaining the pluripotent and self-renewing state of embryonic stem （ES） cells but also acts as a cell fate determinant through a gene dosage effect. However, the molecular mechanisms that control the intracellular OCT4 protein level remain elusive. Here, we report that human WWP2, an E3 ubiquitin （Ub）-protein ligase, interacts with OCT4 specifically through its WW domain and enhances Ub modification of OCT4 both in vitro and in vivo. We first demonstrated that endogenous OCT4 in hu- man ES cells can be post-translationally modified by Ub. Furthermore, we found that WWP2 promoted degradation of OCT4 through the 26S proteasome in a dosage-dependent manner, and the active site cysteine residue of WWP2 was required for both its enzymatic activity and proteolytic effect on OCT4. Remarkably, our data show that the en- dogenous OCT4 protein level was significantly elevated when WWP2 expression was downregulated by specific RNA interference （RNAi）, suggesting that WWP2 is an important regulator for maintaining a proper OCT4 protein level in human ES cells. Moreover, northern blot analysis showed that the WWP2 transcript was widely present in diverse human tissues/organs and highly expressed in undifferentiated human ES cells. However, its expression level was quickly decreased after human ES cells differentiated, indicating that WWP2 expression might be developmentally regulated. Our findings demonstrate that WWP2 is an important regulator of the OCT4 protein level in human ES cells.
基金funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No.813393partially funded by the Portuguese FCT-Funda??o para a Ciência e a Tecnologia,under projects UIDB/50010/2020,UIDP/50010/2020 and PTDC/FIS-PLA/1616/2021。
文摘This paper brings the comparison of performances of CO_(2)conversion by plasma and plasma-assisted catalysis based on the data collected from literature in this field,organised in an open access online database.This tool is open to all users to carry out their own analyses,but also to contributors who wish to add their data to the database in order to improve the relevance of the comparisons made,and ultimately to improve the efficiency of CO_(2)conversion by plasma-catalysis.The creation of this database and database user interface is motivated by the fact that plasma-catalysis is a fast-growing field for all CO_(2)conversion processes,be it methanation,dry reforming of methane,methanolisation,or others.As a result of this rapid increase,there is a need for a set of standard procedures to rigorously compare performances of different systems.However,this is currently not possible because the fundamental mechanisms of plasma-catalysis are still too poorly understood to define these standard procedures.Fortunately however,the accumulated data within the CO_(2)plasma-catalysis community has become large enough to warrant so-called“big data”studies more familiar in the fields of medicine and the social sciences.To enable comparisons between multiple data sets and make future research more effective,this work proposes the first database on CO_(2)conversion performances by plasma-catalysis open to the whole community.This database has been initiated in the framework of a H_(2)0_(2)0 European project and is called the“PIONEER Data Base”.The database gathers a large amount of CO_(2)conversion performance data such as conversion rate,energy efficiency,and selectivity for numerous plasma sources coupled with or without a catalyst.Each data set is associated with metadata describing the gas mixture,the plasma source,the nature of the catalyst,and the form of coupling with the plasma.Beyond the database itself,a data extraction tool with direct visualisation features or advanced filtering functionalities has been dev
文摘Acupuncture has been experimentally proved to be capable of exciting various groups of fibres. However, opinions differ as to which group of fibres is mainly responsible for conveying analgesic impulses. While some consider that large-sized fibres are concerned with analgesia, others maintain that the engagement of Group Ⅲ fibres will produce better analgesic effect. As for the role played by Group Ⅳ fibres in the effect of analgesia, some authors take a negative attitude, being void of sufficient evidence.
文摘S. R. Capps first gave the name rock glacier on the geologic map of the United States tes in 1910. It is a tongue-like or leaf-like accumulation commonly formed by massive gravels in periglacier regions and distributed mainly on medium- and high-latitude high mountains. The genesis and form of the rock glacier are rather complicated, and differ-
文摘Human LAK cells were prepared by culturing normal human peripheral blood mononuclear cells (PBMC) with or without rIL-2 and assayed for T cell surface markers as well as anti-tumor activity against PC in vitro and in nude mice. Although the percentages of T3, T4, and T8 positive cells in rIL-2-activated cells did not differ significantly from those of control cells in vitro, the former showed stronger cytotoxicity than control cells to PG tumor cells in vitro. In vivo, LAK cells completely inhibited the growth of PG tumor in nude mice, whereas PBMC control cells were to be of no effect. The anti-tumor effect of human LAK cells in nude mice may offer a useful model to study the role of human LAK cells against human tumor in vivo.
文摘Objective: To investigate the potential of superparamagnetic iron oxide particles (SPIO) in MR imaging for the differentiation between hyperplastic and metastatic lymph node. Methods: Animal models of malignant lymph node metastasis were established in 6 New-Zealand rabbits by a unilateral intra-muscular injection of VX2 carcinoma cells, and models of hyperplastic lymph nodes were induced in another 6 rabbits by a unilateral intra-muscular injection of egg yolk emulsion. MR images of the lymph nodes were obtained before and 12 h after interstitial injection of SPIO. Image results were analyzed and compared with pathological findings. Results: On unenhanced images, the signal intensity of hyperplastic and metastatic lymph nodes did not differ significantly. After administration of SPIO, the signal intensity of both hyperplastic and metastatic lymph nodes remained unchanged on T1-weighted SE images. On T2-weighted SE images, the signal intensity of hyperplastic lymph nodes decreased heterogeneously, while that of all metastatic ones remained unchanged. On T2-weighted GRE images, the signal intensity of hyperplastic lymph nodes decreased significantly and homogeneously, while that of 4 metastatic ones remained unchanged and that of the rest 2 decreased heterogeneously. Conclusion: SPIO-enhanced MR imaging may enable the differentiation between the hyperplastic and metastatic lymph nodes.
文摘The density of dendritic cells (DC) and macro-phages (Mφ) in tissue specimens of gastric carcinoma (GC n=65) was investigated by ABC im-munohistochemical method using anti-S100 protein and anti-lysozyme antibodies, and was compared with that in gastric ulcer (GU n=19), chronic atrophic gastritis (CAG n=28) and normal gastric mucosa (NGM n=15). The mean density if DC (cells/mm2) in GC (15.0 was significantly higher than that in NGM (3.8) and GU (8.3), but was remarkably lower when compared to that in CAG (29.5) (P<0.01). Statistically significant difference in the population density of DC was observed between well- and poorly-differentiated GC (P<0.01). With their unique dendritic processes, DC were mainly concentrated within dense lymphoid infiltrates or in the T-area of reactive lymphoid follicles and were interspersed among the tumor cells. In contrast, Mφ were present around the necrotic foci and were rarely seen within the non-necrotic neoplastic tissues. These data suggest that DC, which differ in morphology, distribution, number and function form Mφ may be more directly involved in the host immune reaction against tumor by acting as antigen presenting cells.
基金supported by the Innovation Fund for Chemistry of NWO,grant number 731.014.303by SASOL。
文摘The effect of temperature and hydrogen addition on undesired carbonaceous deposit formation during methane coupling was studied in DBD-plasma catalytic-wall reactors with Pd/Al2 O3, using electrical power to drive the reaction.Experiments with thin catalyst layers allowed comparison of the performance of empty reactors and catalytic wall reactors without significantly influencing the plasma properties.The product distribution varies strongly in the temperature window between 25 and 200℃Minimal formation of deposits is found at an optimal temperature around 75℃ in the catalytic-wall reactors.The selectivity to deposits was c.a.10% with only 9 mg of catalyst loading instead of 45% in the blank reactor,while decreasing methane conversion only mildly.Co-feeding H2 to an empty reactor causes a similar decrease in selectivity to deposits,but in this case methane conversion also decreased significantly.Suppression of deposits formation in the catalytic-wall reactor at 75℃ is due to catalytic hydrogenation of mainly acetylene to ethylene.In the empty reactor,H2 co-feed decreases conversion but does not change the product distribution.The catalytic-wall reactors can be regenerated with H2-plasma at room temperature,which produces more added-value hydrocarbons.
文摘173 simultaneous determinations of serum copper levels (SCL), serum zinc levels (SZL) and copper/zinc ratio (CZR) were made by atomic absorption spectrophotometry in 51 previously untreated lymphoma patients. SCL and CZR were significantly higher in patients before treatment (mean value 22.97 μmol/L, 1.55, respectively) and in those who did not reach complete remission (mean 21.21 μmol/L, 1.36) as compared with the patients in complete remission (mean 16.36 μmol/L, 1.06) or normal controls (mean 15.67 μmol/L, 0.98). The mean value of SCL and CZR of patients in complete remission did not differ significantly from those of normal controls. Patients in stages HI and IV had higher SCL and CZR (mean 25.15 μmol/L, 1.79) than those in stage Ⅰ and Ⅱ (mean 19.30 μmol/L, 1.16). No significant difference in SZL was observed between the patient groups and normal controls. Thus, SCL and CZR may be used as prognostic indicators for monitoring disease activity and response to therapy in malignant lymphoma.
基金support by the Dutch Research Council(Nederlandse Organisatie voor Wetenschappelijk Onderzoek)via the NWO Vidi award 680-47-550.
文摘Light absorption and scattering of plasmonic metal nanoparticles can lead to non-equilibrium charge carriers,intense electromagnetic near-fields,and heat generation,with promising applications in a vast range of fields,from chemical and physical sensing to nanomedicine and photocatalysis for the sustainable production of fuels and chemicals.Disentangling the relative contribution of thermal and non-thermal contributions in plasmon-driven processes is,however,difficult.Nanoscale temperature measurements are technically challenging,and macroscale experiments are often characterized by collective heating effects,which tend to make the actual temperature increase unpredictable.This work is intended to help the reader experimentally detect and quantify photothermal effects in plasmon-driven chemical reactions,to discriminate their contribution from that due to photochemical processes and to cast a critical eye on the current literature.To this aim,we review,and in some cases propose,seven simple experimental procedures that do not require the use of complex or expensive thermal microscopy techniques.These proposed procedures are adaptable to a wide range of experiments and fields of research where photothermal effects need to be assessed,such as plasmonic-assisted chemistry,heterogeneous catalysis,photovoltaics,biosensing,and enhanced molecular spectroscopy.
基金part of the European project KEROGREEN,which has received funding from the European Union’s Horizon 2020 Research and Innovation Programme under Grant Agreement no.763909funding from the initiative“Computational Sciences for Energy Researcah”of Shell and the Netherlands Organization for Scientific Research(NWO)grant no.15CSTT05。
文摘Electrocatalytic and plasma-activated processes receive increasing attention in catalysis. Density functional theory(DFT) calculations are state-of-the-art tools for the fundamental study of reaction mechanisms and predicting the performance of catalytic materials. Proper application of DFT-based methods is crucial when investigating charge-doped electrode surfaces during electrocatalytic and plasma-activated reactions. Here, as a model electrode for plasma-activated CO2 splitting, we studied the interactions of O, CO, and CO2 with the neutral and progressively charged Ag(111) metal surfaces. We show that the application of correction procedures is necessary to obtain accurate adsorption energy profiles of O atoms,CO and CO2 molecules on Ag surfaces that are under the influence of additional electrons. Interestingly,the oxidation of CO is found to shift from a Langmuir–Hinshelwood mechanism on a neutral electrode to an Eley–Rideal mechanism on charged electrodes. Furthermore, we show that the surface charging of Ag(111) electrodes increase their CO2 reduction performance by enhancing the adsorption of O atoms and desorption of CO molecules. A further increase in the absolute charge-state of the electrode surface is expected to waive the thermodynamic barriers for the CO2 splitting reaction.
文摘In recent years,artificial intelligence(AI)methods have prominently proven their use in solving complex problems.Across science and engineering disciplines,the data-driven approach has become the fourth and newest paradigm.It is the burgeoning of findable,accessible,interoperable,and reusable(FAIR)data generated by the first three paradigms of experiment,theory,and simulation that has enabled the application of AI methods for the scientific discovery and engineering of compounds and materials.Here,we introduce a recipe for a data-driven strategy to speed up the virtual screening of two-dimensional(2D)materials and to accelerate the discovery of new candidates with targeted physical and chemical properties.As a proof of concept,we generate new 2D candidate materials covering an extremely large compositional space,downselect 316,505 likely stable 2D materials,and predict the key physical properties of these new 2D candidates.Finally,we hone in on the most propitious candidates of functional 2D materials for energy conversion and storage.
基金supported by a MacGillavry Fellowship(K.D.)the Stichting voor Fundamenteel Onderzoek der Materie(FOM)+1 种基金which is part of the Netherlands Organisation for Scientific Research(NWO,K.D.,I.D.)NanoNextNL program(I.D.)funded by the Dutch Ministry of Economic Affairs and Vici fellowship from NWO(B.B.and P.S.)。
文摘Silicon nanocrystals(SiNCs)have great potential to become environmental friendly alternatives to heavy-metal containing nanocrystals for applications including medical imaging,lighting and displays.SiNCs exhibit excellent photostability,non-toxicity and abundant resources,but their often reported inefficient and spectrally limited light emission seriously impair their applications.Here we demonstrate a new method that converts SiNCs into an efficient and robust multi-chromatic phosphor.Using~15 keV electron-beam irradiation of oxide-capped SiNCs,we introduce several types of color centers into the nanocrystal’s oxide shell with efficient blue,green and red emission bands,together yielding warm-white photoluminescence,even for a single SiNC.Introduced centers are not native to the original system and we relate them to known defects in silica.Unlike in the silica host,however,here the centers are efficiently optically excitable.Provided further optimization and up-scaling of this method,e-beam irradiated SiNCs can be of great interest as white phosphors for applications such as LEDs.
