Vehicular sensor networks (VSNs) have emerged as a paradigm for improving traffic safety in urban cities. However, there are still several issues with VSNs. Vehicles equipped with sensing devices ...usually upload large amounts of data reports to a remote cloud center for processing and analyzing, causing heavy computation and communication costs. Additionally, to choose an optimal route, it is required for vehicles to query the remote cloud center to obtain road conditions of the potential moving route, leading to an increased communication delay and leakage of location privacy. To solve these problems, this paper proposes an efficient privacy-preserving data sharing (EP 2 DS) scheme for fog-assisted vehicular sensor networks. Specifically, the proposed scheme utilizes fog computing to provide local data sharing with low latency; furthermore, it exploits a super-increasing sequence to format the sensing data of different road segments into one report, thus saving on the resources of communication and computation. In addition, using the modified oblivious transfer technology, the proposed scheme can query the road conditions of the potential moving route without disclosing the query location. Finally, an analysis of security suggests that the proposed scheme can satisfy all the requirements for security and privacy, with the evaluation results indicating that the proposed scheme leads to low costs in computation and communication.
La-modified NiMgAl catalysts derived from hydrotalcites exhibited remarkably enhanced stability during the carbon dioxide reforming of methane because of their strong resistance to coke deposition. ...The reduced Ni0.5Mg2.5AlO4.5 (a) and Ni0.5Mg2.5Al0.9La0.1O4.5 (b) catalysts and the spent Ni0.5Mg2.5AlO4.5 (c) and Ni0.5Mg2.5Al0.9La0.1O4.5 (d) catalysts. Display omitted
► Ni catalysts showed a narrow Ni0 particle-size distribution between 5 and 11nm. ► Adding La increased the basicity and surface Ni content of the NiMgAl catalysts. ► Introducing La significantly improved the stability of the NiMgAl catalysts. ► La inhibited coking by forming La2O2CO3 and improving basicity and Ni0 dispersion.
La-promoted NiMgAl mixed-oxide catalysts derived from hydrotalcite were synthesized by coprecipitation for the carbon dioxide reforming of methane. X-ray diffraction, thermogravimetric analysis, temperature-programmed reduction, X-ray photoelectron spectroscopy, temperature-programmed desorption of carbon dioxide, hydrogen chemisorption and transmission electron microscopy were used to investigate the structure and deactivation characteristics of the catalysts. The catalysts exhibited a narrow Ni-metal particle-size distribution between 5 and 11nm. The presence of lanthanum evidently improved reforming activity in the temperature range of 600–700°C, because the introduction of lanthanum into the NiMgAl catalysts increased the total amount of basic sites and the surface Ni content. The activity of the Ni0.5Mg2.5Al0.9La0.1O4.5 catalyst was slightly higher than those of the other lanthanum-containing catalysts. The addition of lanthanum improved the stability of the NiMgAl catalysts significantly because of the suppression of coke deposition. Lanthanum effectively inhibited coking by increasing the basicity of the catalysts, forming the La2O2CO3 phase and improving nickel metal dispersion.
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► The supported LaNiO3 perovskite catalysts on three mesoporous carrier with different structural features have been synthesized. ► In comparison with that of the bulk LaNiO3 ...perovskite, the supported samples showed much better catalytic performance. ► The relationships between catalytic behavior and property of catalysts have been established. ► The catalyst deactivation aspect has been discussed in detail.
The supported LaNiO3 perovskite catalysts on mesoporous carrier (LaNiO3/SBA-15, LaNiO3/MCM-41 and LaNiO3/SiO2) with different pore structures have been synthesized via filling the pores of mesoporous silica with citrate complex precursors of nickel and lanthanum, with further treatments. The catalysts were characterized by means of N2 physisorption, XRD, HRTEM+EDX, TPR, temperature-programmed hydrogenation (TPH) and TGA techniques, and their catalytic performances were measured in methane dry reforming with carbon dioxide to hydrogen and synthesis gas (syngas). The results of low-angle XRD, N2 physisorption and TEM analysis showed that LaNiO3 perovskite was formed inside the channels of mesoporous supports, and the introduction of LaNiO3 perovskite did not destroy the mesoporous structure of support. The pore structure had a substantial influence on the catalytic performance. LaNiO3/MCM-41 exhibited the higher initial catalytic activity, owing to the higher Ni dispersion, while LaNiO3/SBA-15 was superior to LaNiO3/MCM-41 in the long-term stability, which could be due to the stable silica matrix restricted the agglomeration of nickel species. The hexagonal mesopores of LaNiO3/SBA-15 were still kept intact after reaction, while the mesoporous structure in LaNiO3/MCM-41 was collapsed during the reaction, which resulted in metal particles aggregation to certain extent. For comparison, the carbon deposition was responsible for the remarkable decrease of catalytic activity over LaNiO3/SiO2 sample, evidenced by TGA and TPH results.
A series of MgO-coated SBA-15 mesoporous silica with MgO contents ranging from 2 wt% to 15 wt% have been successfully synthesized by a simple one-pot synthesis method and further impregnated with ...10 wt% Ni. Ni/SBA-15 modified with 8 wt% MgO was also prepared by conventional impregnation method. The materials were characterized by means of XRD, N2 physisorption, TEM by applying high-angle annular dark field (HAADF), XPS, CO2-TPD, TGA and temperature-programmed hydrogenation (TPH) techniques, and their catalytic performance was tested for methane reforming with CO2. The results showed that MgO was successfully coated on the walls of mesoporous silica and the mesoporous structure of SBA-15 was well maintained after MgO modification. Compared to MgO-impregnated material, MgO-coated counterpart showed a better order in the mesostructure and more medium basic sites. The addition of MgO enhanced initial catalytic activity of Ni/SBA-15, and the catalyst with 8 wt% MgO coating showed the most excellent catalytic activity. The MgO coating induced an improved dispersion of Ni species and larger medium basic sites than that of MgO impregnation, which led to an enhanced long-term stability and resistance to carbon formation. The deposition of graphitic carbon species during the reaction was the main reason for the deactivation of Ni/SBA-15 catalyst.
In comparison with those of MgO-impregnated SBA-15 material, the MgO-coated SBA-15 using one-pot strategy possessed obviously larger medium basic sites and a higher dispersion of Ni species, which inhibited the occurring of carbon formation and resulted in a better catalytic stability. Display omitted
•MgO-coated SBA-15 catalysts were prepared by one-pot method.•The coating by MgO induced an improved Ni dispersion and medium basic sites.•The MgO-coated catalyst exhibited excellent catalytic activity and stability.•Carbon deposition was the main reason for the deactivation of catalyst.
Background
The benefits of talazoparib compared with conventional chemotherapy in HER2-negative advanced breast cancer (ABC) remain unclear.
Methods
Patients older than 18 years, with a deleterious ...germline BRCA1/2 (gBRCA1/2) mutated, metastatic, or locally advanced and HER2-positive breast cancer were enrolled. Patient data including age, menostatus, tumor grade, pathologic tumor size, lymph node status, and whether they had received adjuvant radiation or chemotherapy was collected. The primary outcomes of the study were disease-free survival (DFS), which was defined as the time from randomization to death or recurrence due to any reason, and overall survival (OS), which was defined as the time from randomization to death due to any reason. P<0.05 was considered to be statistically significant.
Results
A total of 136 patients were finally enrolled in the present retrospective study, including 62 patients in the talazoparib group (group A) and 74 in the conventional chemotherapy group (group B). After a median follow-up of 70.9 months 95% confidence interval (CI): 68.3–78.5, both DFS and OS did not differ significantly between the two groups (P=0.658 and P=0.690, respectively). The exploratory subgroup analyses further validated the robustness of the primary results across the subgroups.
Conclusions
Talazoparib was not better than conventional chemotherapy in terms of DFS and OS for the treatment of gBRCA1/2 mutated HER2-positive breast cancer patients.
► We modified one coal with H2O2, (NH4)2S2O8 and HNO3 respectively, to prepare coal samples with different surface properties. ► The oxygen groups on coal surface were characterized by XPS. ► The ...textures of the coal samples were investigated by N2 adsorption at 77K. ► The adsorption behaviors were measured by volumetric method. ► There was a negative correlation between methane saturated adsorption capacity and the Ototal/Ctotal.
To investigate the influence of surface oxygen groups on methane adsorption on coals, one bituminous coal was modified with H2O2, (NH4)2S2O8 and HNO3 respectively, to prepare coal samples with different surface properties. The oxygen groups on coal surface were characterized by X-ray photoelectron spectroscopy (XPS). The textures of the coal samples were investigated by N2 adsorption at 77K. Their surface morphologies were analyzed by scanning electron microscopy (SEM). The methane adsorption behaviors of these coal samples were measured at 303K in pressure range of 0–5.3MPa by volumetric method. The adsorption data of methane were fitted to the Langmuir model and Dubinin–Astakhov (D–A) model. The fitting results showed that the D–A model fitted the isotherm data better than the Langmuir model. It was observed that there was, in general, a positive correlation between the methane saturated adsorption capacity and the micropore volume of coals while a negative correlation between methane saturated adsorption capacity and the Ototal/Ctotal. The methane adsorption capacity was determined by the coal surface chemistry when the microporosity parameters of two samples were similar. Coal with a higher amount of oxygen surface groups, and consequently with a less hydrophobic character, had lower methane adsorption capacity.
Poly (ADP-ribose) polymerase (PARP) inhibitors are a therapeutic milestone exerting a synthetic lethal effect in the treatment of cancer involving
mutation. Theoretically, PARP inhibitors (PARPi) ...eliminate tumor cells by disrupting DNA damage repair through either PARylation or the homologous recombination (HR) pathway. However, resistance to PARPi greatly hinders therapeutic effectiveness in triple-negative breast cancer (TNBC). Owing to the high heterogeneity and few genetic targets in TNBC, there has been limited therapeutic progress in the past decades. In view of this, there is a need to circumvent resistance to PARPi and develop potential treatment strategies for TNBC. We present, herein, a review of the scientific progress and explore the mechanisms underlying PARPi resistance in TNBC. The complicated mechanisms of PARPi resistance, including drug exporter formation, loss of poly (ADP-ribose) glycohydrolase (PARG), HR reactivation, and restoration of replication fork stability, are discussed in detail in this review. Additionally, we also discuss new combination therapies with PARPi that can improve the clinical response in TNBC. The new perspectives for PARPi bring novel challenges and opportunities to overcome PARPi resistance in breast cancer.
In the present work, non-equilibrium molecular dynamics (MD) simulations are used to investigate the flow of liquid water between two metallic solid atomistic smooth walls. The present work focuses ...on the combined effect of external electric field and driving force on the slip behaviour and structure of liquid water at the solid-water interface. The upper wall of the set model is positively charged, and the lower wall of the model is negatively charged. The simulation results show that as the driving force increases, the slip length also increases. At a given driving force, no matter how the electric field intensity changes, there is almost no change in the slip length, so the slip length is independent of the electric field strength. In addition, the results found that there is a linear relationship between the slip length and the normalised main peak of the static structure factor under different driving forces.
Apoptosis is orchestrated by a family of cysteine proteases known as the caspases, and caspase3 is the primary executioner caspase in the apoptosis. In the present study, the potential role of ...caspase3 was investigated under the exposure to high temperature and elevated ammonium in stony coral Pocillopora damicornis. The cDNA of a caspase3 (PdCaspase3) was identified to encode a polypeptide of 344 amino acids, and the encoded protein contained one CASc domain (Caspase, interleukin-1 beta converting enzyme homologues, from Val76 to Asn333). The recombinant protein of the mature PdCaspase3 was expressed in Escherichia coli BL21 (DE3)-Transetta, and it displayed caspase3-like activity which catalyzed the reaction of DEVD-p-nitroanilide cleavage. The expression level of PdCaspase3 mRNA increased significantly at 24h after acute heat stress and 12h after acute ammonium stress, reached 2.28-fold (P<0.05) and 1.76-fold (P<0.05) of that in the blank group, respectively. The activation level of caspase3 began to increase at 12h (1.41-fold, P<0.05), and reached the peak at 24h (1.54-fold, P<0.05) after acute heat stress. Furthermore, the activation level of caspase3 increased significantly during 6–24h, with the highest level at 24h (1.44-fold, P<0.05) after acute ammonium stress. These results collectively suggested that PdCaspase3, as a homologue of caspase3, was involved in the response to high temperature and elevated ammonium, which might further regulate the symbiosis between the host and zooxanthellae in the stony coral P. damicornis.
•PdCaspase3 cDNA encoded a polypeptide of 344 amino acids.•PdCaspase3 recombinant protein displayed caspase3-like activity.•PdCaspase3 expression increased significantly after acute heat and ammonium stress.•Activation level of caspase3 increased significantly after heat and ammonium stress.
Coral skeleton δ13C is a routinely measured indicator in modern insolation change research, but the knowledge of environmental and climatic signals recorded in its seasonality during geological time ...is sparse. In this study, we present eight Porites coral δ13C records from the mid‐late Holocene to the present from the northern South China Sea (NSCS). Compared with the main control factors for modern δ13C changes, coral δ13C seasonality in the NSCS since the mid‐Holocene shows a long‐term decreasing trend, which is consistent with the change trend as orbital‐induced (precession) insolation seasonal amplitude. By excluding other influencing factors, we speculate that the stronger coral δ13C seasonality (18.8%) over the mid‐Holocene than modern period is attributable to the metabolic effect, which predicts the stronger coral δ13C seasonality under stronger insolation seasonality. Our study has implications for coral δ13C seasonality as a potential indicator to record past insolation information under different climatic backgrounds.
Plain Language Summary
Numerous studies have documented the seasonal features of fast‐growing modern coral skeleton δ13C in response to insolation variation. The environmental and climatic signals recorded by coral δ13C seasonality in the geological period remain unclear owing to the relatively short length of observation records. Here we present monthly resolved δ13C records in seven fossil Porites corals (5.6–3.6 ka BP, before 1950 CE) and one modern Porites coral (1987–2001 CE) from the northern South China Sea (NSCS). Compared with the widely accepted prevailing control factors for modern coral δ13C, our results indicated that the stronger coral δ13C seasonality (18.8%) over the mid‐Holocene compared to the modern period is consistent with the orbital‐induced (precession) insolation changes, which indicate a declining seasonality from the mid‐Holocene to present. By excluding other influencing factors, we infer that a tendency toward higher δ13C seasonality during the mid‐Holocene was primarily driven by the metabolic fractionation caused by the enhanced insolation seasonality. This study highlighted coral δ13C seasonality as a potential indicator for recording past insolation information.
Key Points
The seasonal variation of modern coral skeleton δ13C in the northern South China Sea (NSCS) is primarily controlled by solar insolation
Coral δ13C seasonality in the NSCS since the mid‐Holocene shows a long‐term decreasing trend
The decrease of orbital‐induced (precession) insolation seasonal amplitude led to the declining trend of δ13C seasonality
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