The Implications of Diverse Applications and Scalable Data Sets in Benchmarking Big Data Systems

Now we live in an era of big data, and big data applications are becoming more and more pervasive. How to benchmark data center computer systems running big data applications (in short big data systems) is a hot topic. In this paper, we focus on measuring the performance impacts of diverse applications and scalable volumes of data sets on big data systems. For four typical data analysis applications---an important class of big data applications, we find two major results through experiments: first, the data scale has a significant impact on the performance of big data systems, so we must provide scalable volumes of data sets in big data benchmarks. Second, for the four applications, even all of them use the simple algorithms, the performance trends are different with increasing data scales, and hence we must consider not only variety of data sets but also variety of applications in benchmarking big data systems.Comment: 16 pages, 3 figure

Association between plasma trimethylamine N -oxide and neoatherosclerosis in patients with very late stent thrombosis

Abstract(#br)Background(#br)Trimethylamine N -oxide (TMAO) has been shown to promote the development of atherosclerosis. However, the relationship between plasma TMAO and neoatherosclerosis, an important underlying mechanism of very late stent thrombosis (VLST), is unknown.(#br)Methods(#br)This post hoc study investigated the association between TMAO and neoatherosclerosis in two independent cohorts. These included a control group of 50 healthy volunteers and a study cohort of 50 patients with VLST who presented with ST-segment elevation myocardial infarction and underwent optical coherence tomography examination. Of the 50 patients with VLST, 23 had neoatherosclerosis and 27 did not have neoatherosclerosis. Patients with neoatherosclerosis were further divided into two subgroups, including 14 patients with plaque rupture and 9 without plaque rupture.(#br)Results(#br)The plasma TMAO levels, detected using mass spectrometry, were significantly higher in patients with VLST than in healthy individuals (median [interquartile range]: 2.50 [1.67-3.84] vs. 1.32 [0.86-2.44] μM; P < 0.001). Among the VLST patients, the plasma TMAO levels were significantly higher in patients with neoatherosclerosis than in those without neoatherosclerosis (3.69 [2.46-5.29] vs. 1.96 [1.39-2.80] μM; P<0.001). In addition, in patients with neoatherosclerosis, patients with plaque rupture had significantly higher plasma TMAO concentrations than those without plaque rupture (4.51 [3.41-5.85] vs. 2.46 [2.05-3.55] μM; P=0.005). Multivariate analysis indicated that TMAO was an independent predictor of neoatherosclerosis (odds ratio 3.41; 95% confidence interval: 1.59-7.30; P=0.002). Moreover, the area under the receiver operating characteristic curve for TMAO, differentiated by neoatherosclerosis, was 0.85.(#br)Conclusions(#br)Plasma TMAO was significantly correlated with neoatherosclerosis and plaque rupture in patients with VLST

Discriminative analysis of schizophrenia patients using graph convolutional networks: A combined multimodal MRI and connectomics analysis

IntroductionRecent studies in human brain connectomics with multimodal magnetic resonance imaging (MRI) data have widely reported abnormalities in brain structure, function and connectivity associated with schizophrenia (SZ). However, most previous discriminative studies of SZ patients were based on MRI features of brain regions, ignoring the complex relationships within brain networks.MethodsWe applied a graph convolutional network (GCN) to discriminating SZ patients using the features of brain region and connectivity derived from a combined multimodal MRI and connectomics analysis. Structural magnetic resonance imaging (sMRI) and resting-state functional magnetic resonance imaging (rs-fMRI) data were acquired from 140 SZ patients and 205 normal controls. Eighteen types of brain graphs were constructed for each subject using 3 types of node features, 3 types of edge features, and 2 brain atlases. We investigated the performance of 18 brain graphs and used the TopK pooling layers to highlight salient brain regions (nodes in the graph).ResultsThe GCN model, which used functional connectivity as edge features and multimodal features (sMRI + fMRI) of brain regions as node features, obtained the highest average accuracy of 95.8%, and outperformed other existing classification studies in SZ patients. In the explainability analysis, we reported that the top 10 salient brain regions, predominantly distributed in the prefrontal and occipital cortices, were mainly involved in the systems of emotion and visual processing.DiscussionOur findings demonstrated that GCN with a combined multimodal MRI and connectomics analysis can effectively improve the classification of SZ at an individual level, indicating a promising direction for the diagnosis of SZ patients. The code is available at https://github.com/CXY-scut/GCN-SZ.git

Controllable synthesis of Si-DD3R molecular sieves nanocrystalline by microwave assisting dry-gel conversion method

All-silica Deca-Dodecasil 3 Rhombohedral (Si-DD3R) type zeolite with a two-dimensional pore system is a very attractive size selective adsorbent which enables only small molecules to adsorb. It is a great potential candidate in the fields of separation and catalysis. In this work, nanocrystalline Si-DD3R molecular sieves with the particle size of about 30 nm were synthesized by microwave assisting dry-gel conversion (MADGC) method. The advantages of microwave radiation, HF and dry-gel conversion (DGC) were well combined and effectively decrease the size and in situ synthesis time. At 433 K, highly uniform nancrystalline Si-DD3R was obtained in 7 h without seeding. When the partial pressure was 1.0 bar, the CO _2 adsorbed amount reached about 0.83 mmol g ^−1 . The zeolites are characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electron microscopy (TEM)

Ionothermal synthesis of AlPO-34 membranes on macroporous α-Al2O3 supports without using organic template

Continuous and compact AlPO-34 molecular sieve membranes were successfully synthesized on the outer surface of macroprous tube α-Al2O3 supports under secondary ionothermal growth with the proposed wetting seed layer. The recyclable ionic liquids (ILs) can both act as solvent media and the structure-directing agent (SDA) of the aiming topological structure of CHA, largely reducing the wastewater. Wetting the seed layer could accelerate the diffusion of ILs to the surface of the support and further increase the binding force between the membrane and the support. Compared with the open system, the closed system led to the achievement of the high-quality AlPO-34 membrane. The H2 permeance of the resulting membrane was 9.74 × 10−8 mol m−2 s−1 Pa−1 and the ideal selectivities of H2/CO2, H2/N2, H2/CH4, H2/C3H8 and H2/i-C4H10 were 7.48, 8.54, 14.67, 39.25 and 65.83, respectively, which were higher than Knudsen diffusion ratios. The obtained membrane was firstly explored for the PV dehydration of isopropyl alcohol (90 wt%)/water mixtures, exhibiting good performance with the separation factor of 147 and high water flux of 1.09 kg m−2 h−1

Growth Study of Hierarchical Pore SSZ-13 Molecular Sieves with Improved CO₂ Adsorption Performance

SSZ-13, with a unique pore structure and excellent thermal stability, showed a potential application in the adsorption and catalysis industry. In this work, Al(NO3)3 was used as an Al source to study the performance and morphology of the zeolite. The zeolite was prepared with an unconventional process by adding an Al source before the structure-directing agent and base. When inorganic oxygen-containing anions were introduced into the unconventional synthesis system, the crystals of the zeolite conform to the unconventional growth mode. The zeolites with large crystals were assembled from small unit nanocrystals. Extending the reaction time, aging time and adding fluoride ions introduced a multistage pore structure on the surface of the molecular sieve, which improved the CO2 adsorption performance. When aging for 24 h, reaction for 96 h, and the amount of fluorine added was 0.05 (F/Si), the sample had the best hierarchical pore structure. The SSZ-13 molecular sieve with an added amount of 0.1 (F/Si) has the highest CO2 adsorption performance. The adsorption amount was 4.55 mmol/g at 1 bar, which is 20.4% higher than that of zeolite SSZ-13 prepared by the conventional process

Synthesis of self-assembled hierarchical AlPO-34 microspheres by using an ionic liquid and its application in heavy metal removal

Hierarchical AlPO-34 molecular sieves microspheres were synthesized in a [BMIm]Br ionic liquid without template or complex post-treatment process. The formation mechanism of such framework structures and their morphology were investigated. [BMIm]Br was proven to serve as both solvent and sole provider of the structure directing agent. The organic amine in the compound affects the framework density of the crystals and promotes the formation of a chabazite (CHA) type framework. After ageing for 1 h the AlPO-34 microspheres are formed due to the aggregation properties of the ionic liquid. The hierarchical mirosphere has a relatively high Brunauer–Emmett–Teller surface area and a considerably uniform mesoporous channel network. The hierarchical AlPO-34 microspheres were used as absorbers of heavy metal cations and showed a higher loading capacity and distribution coefficient compared with the AlPO-34-NH

Optimized Preparation of Nanosized Hollow SSZ-13 Molecular Sieves with Ultrasonic Assistance

Because of its unique eight-membered ring pore structure and the arrangement of cations in its structure, the SSZ-13 molecular sieve has a higher affinity for CO2 than other gases, meaning it has attracted more attention than other porous materials for CO2 adsorption. However, the expensive template and long preparation time limits the industrial production of SSZ-13. In this work, a hollow structure was successfully introduced into the nanosized SSZ-13 molecular sieve with ultrasonic treatment. The effects of the amount of seed added and the ultrasonic time on the structure were investigated. When the amount of seed added was 0.5 wt.% and the ultrasonic time was 60 min, the sample showed a hollow cubic crystal with a diameter of about 50 nm. The specific surface area reached 791.50 m2/g, and the mesoporous ratio was 66.3%. The samples were tested for CO2 adsorption performance at 298 K. It was found that the hollow sample prepared in this work has higher CO2 adsorption capacity compared with the SSZ-13 zeolite prepared with conventional methods. When the adsorption pressure was 0.27 bar, the adsorption amount reached 2.53 mmol/g. The hollow SSZ-13 molecular sieve reached a CO2 adsorption capacity of 4.24 mmol/g at 1 bar