23 research outputs found
Synthesis and Characterization of Dendrimer Templated Supported Bimetallic Pt-Au Nanoparticles
Bimetallic dendrimer-stabilized nanoparticles (DSNs) were used to prepare supported Pt-Au catalysts within the bulk miscibility gap for this binary system. Hydroxy-terminated generation 5 PAMAM dendrimers were used to prepare Cu0 nanoparticles (NPs). The Cu0 NPs were subsequently used to reduce K2PtCl4 and HAuCl4, preparing stabilized bimetallic Pt-Au NPs with a 1:1 stoichiometry. The stabilized NPs were adsorbed onto a high surface area silica support and thermally activated to remove the dendrimers. Transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), and infrared spectroscopy of adsorbed CO showed that this preparation route resulted in NPs in which the two metals are intimately mixed and that the majority of the bimetallic NPs were smaller than 3 nm. Further, the bimetallic NPs were highly active for CO oxidation catalysis near room temperature and showed evidence of CO induced restructuring at ambient temperatures
Dendrimer-Encapsulated Nanoparticle Precursors to Supported Platinum Catalysts
In this contribution, we report the successful preparation of supported metal catalysts using dendrimer-encapsulated Pt nanoparticles as metal precursors. Polyamidoamine (PAMAM) dendrimers were first used to template and stabilize Pt nanoparticles prepared in solution. These dendrimer-encapsulated nanoparticles were then deposited onto a commercial high surface area silica support and thermally activated to remove the organic dendrimer. The resulting materials are active oxidation and hydrogenation catalysts. The effects of catalyst preparation and activation on activity for toluene hydrogenation and CO oxidation catalysis are discussed
Collaborative Perception in Autonomous Driving: Methods, Datasets and Challenges
Collaborative perception is essential to address occlusion and sensor failure
issues in autonomous driving. In recent years, theoretical and experimental
investigations of novel works for collaborative perception have increased
tremendously. So far, however, few reviews have focused on systematical
collaboration modules and large-scale collaborative perception datasets. This
work reviews recent achievements in this field to bridge this gap and motivate
future research. We start with a brief overview of collaboration schemes. After
that, we systematically summarize the collaborative perception methods for
ideal scenarios and real-world issues. The former focuses on collaboration
modules and efficiency, and the latter is devoted to addressing the problems in
actual application. Furthermore, we present large-scale public datasets and
summarize quantitative results on these benchmarks. Finally, we highlight gaps
and overlook challenges between current academic research and real-world
applications. The project page is
https://github.com/CatOneTwo/Collaborative-Perception-in-Autonomous-DrivingComment: 18 pages, 6 figures. Accepted by IEEE Intelligent Transportation
Systems Magazine. URL:
https://github.com/CatOneTwo/Collaborative-Perception-in-Autonomous-Drivin
Omecamtiv mecarbil in chronic heart failure with reduced ejection fraction, GALACTICâHF: baseline characteristics and comparison with contemporary clinical trials
Aims:
The safety and efficacy of the novel selective cardiac myosin activator, omecamtiv mecarbil, in patients with heart failure with reduced ejection fraction (HFrEF) is tested in the Global Approach to Lowering Adverse Cardiac outcomes Through Improving Contractility in Heart Failure (GALACTICâHF) trial. Here we describe the baseline characteristics of participants in GALACTICâHF and how these compare with other contemporary trials.
Methods and Results:
Adults with established HFrEF, New York Heart Association functional class (NYHA)ââ„âII, EF â€35%, elevated natriuretic peptides and either current hospitalization for HF or history of hospitalization/ emergency department visit for HF within a year were randomized to either placebo or omecamtiv mecarbil (pharmacokineticâguided dosing: 25, 37.5 or 50âmg bid). 8256 patients [male (79%), nonâwhite (22%), mean age 65âyears] were enrolled with a mean EF 27%, ischemic etiology in 54%, NYHA II 53% and III/IV 47%, and median NTâproBNP 1971âpg/mL. HF therapies at baseline were among the most effectively employed in contemporary HF trials. GALACTICâHF randomized patients representative of recent HF registries and trials with substantial numbers of patients also having characteristics understudied in previous trials including more from North America (n = 1386), enrolled as inpatients (n = 2084), systolic blood pressureâ<â100âmmHg (n = 1127), estimated glomerular filtration rate <â30âmL/min/1.73 m2 (n = 528), and treated with sacubitrilâvalsartan at baseline (n = 1594).
Conclusions:
GALACTICâHF enrolled a wellâtreated, highârisk population from both inpatient and outpatient settings, which will provide a definitive evaluation of the efficacy and safety of this novel therapy, as well as informing its potential future implementation
Localization of DJ-1 mRNA in the mouse brain
DJ-1 is mutated in autosomal recessive, early onset Parkinson's disease but the exact localization of the DJ-1 gene product in the mammalian brain is largely unknown. We aimed to evaluate the DJ-1 mRNA expression pattern in the mouse brain. Serial coronal sections of brains of five male and five female adult mice were investigated by using in situ hybridization with a DJ-1 specific 35S-labeled oligonucleotide probe. Hybridized sections were analyzed after exposure to autoradiography films and after coating with a photographic emulsion. DJ-1 was heterogeneously expressed throughout the mouse central nervous system. A high expression of DJ-1 mRNA was detected in neuronal and non-neuronal populations of several structures of the motor system such as the substantia nigra, the red nucleus, the caudate putamen, the globus pallidus, and the deep nuclei of the cerebellum. Furthermore, DJ-1 mRNA was also highly expressed in non-motor structures including the hippocampus, the olfactory bulb, the reticular nucleus of the thalamus, and the piriform cortex. The high expression of DJ-1 mRNA in brain regions involved in motor control is compatible with the occurrence of parkinsonian symptoms after DJ-1 mutations. However, expression in other regions indicates that a dysfunction of DJ-1 may contribute to additional clinical features in patients with a DJ-1 mutation
Dendrimer Templates for Heterogeneous Catalysts: Bimetallic Pt-Au Nanoparticles on Oxide Supports
Polyamidoamine (PAMAM) dendrimers were used to template Pt, Au, and bimetallic PtâAu dendrimer encapsulated nanoparticles (DENs) in solution. Adjusting the solution pH allowed for slow, spontaneous adsorption of the nanoparticles onto silica, alumina, and titania. After dendrimer removal, the catalysts were characterized with infrared spectroscopy of adsorbed CO and tested with CO oxidation catalysis. Infrared spectroscopy of the monometallic Pt catalysts showed a slight shift in the CO stretching frequency for the different supports. For the bimetallic catalysts, infrared spectra showed CO adsorbed on both Pt and on Au sites. Spectra collected during CO desorption showed substantial interactions between the two bands, confirming the presence of bimetallic particles on all the supports. The bimetallic catalysts were found to be more active than the monometallic catalysts and had lower apparent activation energies. The titania supported PtâAu catalyst was resistant to deactivation during an extended treatment at 300 °C. Correlations between IR spectra and catalytic activity showed differences between the mono- and bimetallic materials and implicated a bimetallic PtâAu ensemble at the catalytic active site. This is the first study to show that DENs are appropriate precursors for studying support effects on catalysis by metal nanoparticles, although the magnitude of the effects were small
MiR-361-5p promotes proliferation and inhibits apoptosis of fibroblast-like synoviocytes via targeting ZBTB10 in rheumatoid arthritis
Objectives This study is aimed to explore the key role of miR-361-5p in fibroblast-like synovial (FLS) cells of rheumatoid arthritis (RA) and explore the underlying mechanism. Methods First, we performed RT-qPCR to evaluate the expression of miR-361-5p in both synovial tissues of RA patients and cultured RA-FLS cells. Then CCK-8 assay, EdU staining, Western blot, flow cytometry, and ELISA were conducted to estimate the influence of inhibiting miR-361-5p on RA-FLS cells. Moreover, we used bioinformatics analysis to predict the potential targets of miR-361-5p and perform a dual luciferase report assay for verification. Finally, rescue experiments were performed to prove the role of miR-361-5p/Zinc Finger And BTB Domain Containing 10 (ZBTB10) in the proliferation, cell cycle, and apoptosis of RA-FLS. Results We find that the expression of miR-361-5p is increased in both RA tissues and cultured RA-FLS cells. The inhibition of miR-361-5p can not only inhibit proliferation, arrest the cell cycle in G1/G0 phase, and increase apoptosis, but also reduce the inflammatory factors secreted by RA-FLS cells. In addition, ZBTB10 is a direct target for miR-361-5p, over-expression of ZBTB10 reverses the effect of miR-361-5p in RA-FLS. Conclusions MiR-361-5p promotes the progression of rheumatoid arthritis by targeting ZBTB10.Key points The influences of miR-361-5p on RA-FLS cells
Effects of dopants Ti and Al on microstructure, mechanical and tribological behaviors of ZnO/MoS2 coating deposited by magnetron co-sputtering
This paper investigates the underlying mechanisms of Ti and Al doped into ZnO/MoS2 coatings to develop better tribological properties for MoS2-based lubrication coatings. To this end, Ti-ZnO/MoS2 and Al-ZnO/MoS2 coatings with gradient processing were successfully prepared using magnetron co-sputtering with a subsequent annealing treatment. The effects of Ti and Al on the structures and properties of ZnO/MoS2 coatings were analyzed using various analytical methods. The results showed that Ti-ZnO/MoS2 coatings annealed at 300 °C displayed a minimum friction coefficient of 0.07, and Al-ZnO/MoS2 coatings annealed at 300 °C possessed the best oxidation resistance during wear process. Similarly, the highest nano-hardnesses of Ti and Al doped coatings were 1.9 GPa and 2.0 GPa after annealing at 300 °C. The growth of ZnO grains in Ti-ZnO/MoS2 coatings were different from the other coatings based on the Raman analysis, and Al-doped coating showed better fracture toughness and binding forces from indentation and scratch testing. These results suggest that the respective underlying mechanisms of these metals in ZnO/MoS2 coatings were different. As a result, this study shows that select metals could improve the different properties of metal-ZnO/MoS2 coating by utilizing different mechanisms. Formation of ZnS might account for the synergistic lubrication of ZnO and MoS2 co-doped coatings, and ZnO/MoS2 coatings had moisture resistance because of no sulfate radical appeared by XPS analysis. Therefore, metal-ZnO/MoS2 will be potential lubrication coatings to be widely used under natural ambient conditions
Response of Soil CO 2
Demand for food security and the current global warming situation make high and strict demands on the North China Plain for both food production and the inhibition of agricultural carbon emissions. To explore the most effective way to decrease soil CO2 emissions and maintain high grain yield, studies were conducted during the 2012 and 2013 summer maize growing seasons to assess the effects of wheat straw mulching on the soil CO2 emissions and grain yield of summer maize by adding 0 and 0.6âkgâmâ2 to fields with plant densities of 100â000, 75â000, and 55â000 plants haâ1. The study indicated that straw mulching had some positive effects on summer maize grain yield by improving the 1000-kernel weight. Meanwhile, straw mulching effectively controlled the soil respiration rate and cumulative CO2 emission flux, particularly in fields planted at a density of 75â000 plants haâ1, which achieved maximum grain yield and minimum carbon emission per unit yield. In addition, soil microbial biomass and microbial activity were significantly higher in mulching treatments than in nonmulching treatments. Consequently, summer maize with straw mulching at 75â000 plants haâ1 is an environmentally friendly option in the North China Plain
Comparison of Clinical Characteristic and Prognosis between Ovarian Clear Cell Carcinoma and Serous Carcinoma: A 10-Year Cohort Study of Chinese Patients.
To compare the clinicopathologic features and prognosis of Chinese patients with ovarian clear cell carcinoma (CCC) and serous carcinoma (SC).A retrospective cohort study was designed to investigate the clinicopathologic characteristic and prognosis of patients with CCC and SC who were diagnosed and treated in in a tertiary referral center (Peking Union Medical College Hospital) between 1999 and 2009. The Kaplan-Meier method and Cox regression were employed in the survival analysis.A total of 504 cases were included in the study, comprising 197 cases of CCC and 307 cases of SC. The mean age of the patients with SC was greater than of CCC patients (3.6±0.94, P<0.001). Patients with CCC were more likely to be early-stage and optimally debulked (P<0.001). Regarding cancer-antigen 125, 22% of the patients with CCC had normal values, and the level was significantly lower than in patients with SC (P<0.001). More CCC patients had platinum-resistant tumors compared with platinum-sensitive disease (45.7% in CCC vs. 61.0% in SC [P=0.008]). The 5-year survival rate was 51.2% in the CCC group vs. 49.8% in the SC group (P=0.428). Patients with advanced CCC had a statistically significant poorer overall survival (OS) compared with their SC counterparts (38.0 vs. 52.0 months; hazard ratio 1.584, 95% confidence interval [CI] 1.167-2.150, P=0.003). However, the advantage of improved progression-free survival (PFS) existed across all stages.Women with ovarian CCC presented at a younger age and early stage. Patients with ovarian CCC also had improved PFS, but they had similar OS compared to patients with SC. However, patients with advanced CCC had decreased survival