Cloud-Native Databases: A Survey Dong, Haowen; Zhang, Chao; Li, Guoliang ...
IEEE transactions on knowledge and data engineering,
06/2024
Journal Article
Recenzirano
Cloud databases have been widely accepted and deployed due to their unique advantages, such as high elasticity, high availability, and low cost. Many new techniques, such as compute-storage ...disaggregation and the log is the database, have been proposed recently to seek for higher elasticity and lower cost. To better harness the power of cloud databases, it is crucial to study and compare the pros and cons of their key techniques. In this paper, we offer a comprehensive survey of cloud-native databases. Particularly, we investigate and summarize the state-of-the-art cloud-native OLTP and OLAP databases, respectively. In the first part, we discuss three types of architectures of cloud-native OLTP database. Then we introduce their key techniques including data placement strategy, storage layer consistency, compute layer consistency, multi-layer recovery, and HTAP optimization. In the second part, we present two kinds of architectures of cloud-native OLAP databases. Then we take a deep dive into their key techniques regarding storage management, query processing, serverless computing, data protection, and machine learning in databases. Finally, we discuss the research challenges and opportunities.
Much attention has been paid to endocrine disrupting chemicals (EDCs) due to their widespread presence in various environmental matrices, and endocrine disrupting potential even at low ...concentrations. However, little is known about the multiple EDCs exposure to human and related adverse effects on health, which warrants a multi-residue method for simultaneous determination of EDCs in human samples such as serum. In this study, we developed and validated a novel method for determination of 36 EDCs (8 bisphenols, 7 parabens, 2 antimicrobials, 5 benzophenones, and 14 phthalate metabolites) in human serum with ultra-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS). Two extraction methods (liquid liquid extraction (LLE), and LLE coupled with solid phase extraction (SPE) clean-up) were compared, and eleven solvents and two SPE cartridges were optimized for extraction and clean-up procedure, respectively. Recoveries of target compounds spiked in human serum at three levels of concentrations (0.5, 2.5 and 10 ng/mL) ranged from 45.8% to 120%, and the relative standard deviations (RSDs) were lower than 20%. The linearity of the labeled dilution calibration curve was good with correlation coefficient ranging from 0.995 to 0.999, and the limits of quantification (LOQs) were between 0.002 and 0.532 ng/mL. Low RSDs of intra-day (0.1–12.7%) and inter-day (0.2–13.3%) revealed the accuracy and precision of the quantification. The method was successfully applied to determine the target EDCs in human serum samples from 14 randomly selected individuals. The developed method is a promising method for routine measurement of EDCs in human serum.
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•A simple and robust method for simultaneous determination of 36 EDCs in serum by UPLC-MS/MS was developed.•The pretreatment of LLE extraction in combination with SPE clean-up achieved high recovery and low matrix effect.•MeOH/ACN and MCX were optimized as the better extraction solvent and clean-up SPE cartridge, respectively.•The developed method was validated and successfully applied for determination of real human serum.
Rationale
Endocrine‐disrupting chemicals (EDCs), widespread and easily ingested through the simple food chain, have been suggested to pose potential carcinogenic threats to human health. Considering ...food safety and public health, it is urgent to establish a sensitive and effective method to enrich and determine EDCs in food samples.
Methods
Novel hybrid nanocomposites Fe3O4@A‐TpBD@NH2‐MIL‐125(Ti) were synthesized through the formation of amide bonds. The as‐prepared Fe3O4 were innovatively encapsulated with 4‐aminobenzoic acid functionalized COF(A‐TpBD) to generate bare carboxyl (‐COOH), which formed amide bonds with the NH2‐MIL‐125(Ti), generating well‐defined and hierarchical hybrid materials. The Fe3O4@A‐TpBD@NH2‐MIL‐125(Ti) materials were used as the adsorbents for magnetic solid‐phase extraction (MSPE) coupled with high‐performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS) to enrich and determine EDCs (E1, E2, E3 and BPA) from milk samples.
Results
Fe3O4@A‐TpBD@NH2‐MIL‐125(Ti) exhibited improved adsorption efficiency and selectivity based on π‐π stacking interaction, hydrogen bonding, electrostatic interaction, and the interaction between the hydroxyl group in EDCs and titanium ions (IV, Ti4+). Under the optimized conditions, Fe3O4@A‐TpBD@NH2‐MIL‐125(Ti)‐based MSPE coupled with HPLC/MS/MS showed good linearity with correlation coefficient (R2) ≥0.9983 and high sensitivity with limits of detection (LODs) in the range of 0.37–0.85 μg/L. Moreover, the developed method was successfully employed to detect EDCs in milk samples.
Conclusions
Fe3O4@A‐TpBD@NH2‐MIL‐125(Ti) possess good adsorption capability and selectivity for EDCs. In addition, the proposed MSPE‐HPLC/MS/MS method based on Fe3O4@A‐TpBD@NH2‐MIL‐125(Ti) is effective and sensitive for the determination of EDCs in real samples, which can be used as a robust alternative method to monitor EDCs in complex matrices.
•Functionalized magnetic covalent organic framework composite was facilely prepared.•Magnetic composites were employed for highly effective fluoroquinolones enrichment.•MSPE-HPLC–MS/MS method was ...developed for fluoroquinolones detection in food samples.
Most of the reported covalent organic frameworks (COFs) are hydrophobic, limiting their adsorption application in sample pretreatment field. In this work, sulphonate functionalized magnetic covalent organic frameworks (COFs) composites were first synthesized by loading gold nanoparticles on Fe3O4@COF(TpBD) surface and then functionalized by sodium 3-mercaptopropanesulphonate immobilization via Au-S bonding formation (denoted as Fe3O4@COF(TpBD)@Au-MPS nanocomposites), which were further utilized as adsorbents for magnetic solid-phase extraction (MSPE) of fluoroquinolones. Compared with Fe3O4@COF(TpBD), the composites exhibited higher affinity to fluoroquinolones. Under optimized conditions, the developed MSPE method coupled with HPLC–MS/MS showed good linearity (R2 ≥0.9989) and yielded low limits of detection (0.1–1.0 μg kg−1) for fluoroquinolones. Moreover, the proposed method was successfully applied to extract fluoroquinolones from spiked meats (pork, chicken and bovine). The satisfactory recoveries were in the range of 82–110.2% with the relative standard deviations (RSDs) lower than 7.7%. These results indicated that the Fe3O4@COF(TpBD)@Au-MPS is a promising magnetic adsorbent for trace fluoroquinolones determination in meat samples. This work not only provided a facile strategy for COF functionalization, but also developed an efficient method for detecting fluoroquinolones in foodstuffs.
Background
This study aimed to summarize the clinical features of Autoimmune Glial Fibrillary Acidic Protein Astrocytosis mimicking tuberculosis meningitis to improve clinicians’ understanding of ...this disease.
Methods
We retrospectively analyzed the clinical manifestations, cerebrospinal fluid results, and imaging data of five patients with Autoimmune Glial Fibrillary Acidic Protein Astrocytosis mimicking tuberculous meningitis who were admitted to Xiangya Hospital Central South University between October 2021 and July 2022.
Results
Five patients were aged 31–59 years, with a male-to-female ratio of 4:1. Among the cases reviewed, four had a history of prodromal infections manifesting as fever and headache. One patient developed limb weakness and numbness with clinical manifestations of meningitis, meningoencephalitis, encephalomyelitis, or meningomyelitis. Cerebrospinal fluid analysis revealed an increased cell count in five cases, with a lymphocyte majority. All five cases had a CSF protein level > 1.0 g/L, CSF/blood glucose ratio < 0.5, and two patients had CSF glucose < 2.2 mmol/L. Decreased CSF chloride was observed in three cases, while increased ADA was observed in one case. Both serum and cerebrospinal fluid were positive for anti-GFAP antibodies in three cases, while in two cases, only CSF was positive for anti-GFAP antibodies. Additionally, hyponatremia and hypochloremia were observed in three cases. No tumors were detected in any of the five patients during tumor screening, and all five cases had a good prognosis following immunotherapy.
Conclusion
Anti-GFAP antibody testing should be routinely performed in patients with suspected tuberculosis meningitis to avoid misdiagnosis.
•CuCeWTi-FSP for Hg adsorption is synthesized by flame spray pyrolysis (FSP).•The MOE remains above 95 % after adsorbing 149,000 μg/g of Hg0.•Cu atoms dispersed in CuCeWTi-FSP adsorb oxygen from the ...environment.•The adsorbed oxygen rather than surface oxygen is consumed for CuCeWTi-FSP.
High-concentration mercury capture at high temperatures poses a significant challenge during the periodic shutdown of raw meal mills in cement clinker production. This study synthesized CuOx-CeOx-WO3/TiO2 nanomaterials for mercury removal using wet impregnation, laminar premixed flame (∼1800 K), and flame spray pyrolysis (FSP, ∼ 2800 K). The performance of the synthesized sorbents was evaluated for mercury removal at temperatures above the typical shutdown conditions, specifically at 450 °C. The results demonstrated that the FSP-synthesized sorbent maintained an adsorption efficiency of over 95 % even after 30 days of continuous absorption, while the wet-impregnated sorbent reached saturation after only 50 h. To gain insights into the adsorption mechanism, various physicochemical properties of the sorbents were characterized, including surface area, pore volume, average pore diameter, phase composition, morphology, and valence states of surface elements. The findings revealed that the FSP-synthesized sorbent exhibited a larger specific surface area and smaller primary particle sizes compared to the wet-impregnated sorbent. Furthermore, Cu atoms were dispersed within the FSP-synthesized sorbent, while CuO clusters were supported on CeO2 in the wet-impregnated sorbent. Based on the XPS results, it was determined that the FSP-synthesized sorbent utilized adsorbed molecular oxygen as the oxidizing species, whereas the wet-impregnated sorbent relied on active oxygen on the CeO2 surface.
Abstract
The microlensing effect has developed into a powerful technique for a diverse range of applications including exoplanet discoveries, structure of the Milky Way, constraints on MAssive ...Compact Halo Objects, and measurements of the size and profile of quasar accretion disks. In this paper, we consider a special type of microlensing events where the sources are fast radio bursts (FRBs) with ∼milliseconds (ms) durations for which the relative motion between the lens and source is negligible. In this scenario, it is possible to temporally resolve the individual microimages. As a result, a method beyond the inverse ray shooting method, which only evaluates the total magnification of all microimages, is needed. We therefore implement an algorithm for identifying individual microimages and computing their magnifications and relative time delays. We validate our algorithm by comparing to analytical predictions for a single microlens case and find excellent agreement. We show that the superposition of pulses from individual microimages produces a light curve that appears as multipeaked FRBs. The relative time delays between pulses can reach 0.1–1 ms for stellar-mass lenses and hence can already be resolved temporally by current facilities. Although not yet discovered, microlensing of FRBs will become regular events and surpass the number of quasar microlensing events in the near future when 10
4−5
FRBs are expected to be discovered on a daily basis. Our algorithm provides a way of generating the microlensing light curve that can be used for constraining stellar-mass distribution in distant galaxies.
Optical interconnects play an integral role in large-scale digital computing, switching, and routing systems. The authors describe a path toward future many-chip modules based on silicon photonic ...interposers that stitch together tens of chips in a dense and efficient communication infrastructure. They review the guiding design principles for this "macrochip" and describe its canonical energy, loss, and area budgets.
Answering spatio-temporal range queries (RQs) on trajectory databases, i.e., finding all trajectories that intersect given ranges, is crucial in many real-world applications. Various kinds of indexes ...have been proposed to accelerate RQs. However, existing indexes typically use euclidean distance to prune irrelevant regions without concerning the underlying road network information. Nevertheless, as vehicle trajectories are generated on road network edges, the road network could be seen as meta knowledge of trajectories and be used to index and query trajectories. To this end, we propose RP-Tree, a r oad network-aware p artition tree to support efficient RQs. The basic idea is partitioning a road network graph into hierarchical subgraphs and generate a balanced tree structure, where each tree node maintains its associated trajectories. We compactly index the spatio-temporal information of trajectories on the corresponding road network edges. Then, we design efficient search algorithms to support RQs by pruning irrelevant trajectories through subgraph range borders associated with RP-Tree nodes. Last but not least, we scale RP-Tree to very large datasets by devising approximate algorithms with bounded confidence at an interactive speed. Experimental results on three real-world datasets from Porto, Chengdu, and Beijing show that our method outperform baselines by 1 to 2 orders of magnitude.
Researches on reaction kinetics and mechanism are crucial to the application of hydrogen production technology by supercritical water gasification of coal from experiment to industrialization. Based ...on the migration mechanisms of nitrogen and sulfur in the process, this paper developed a general model including nitrogen and sulfur to study the generation path, consumption path and reaction rate of the gasification products. The parameters of the kinetic model were obtained by fitting the experimental data of the gasification products, and the activation energy of each reaction was obtained by the Arrhenius equation. By comparing the reaction rates among the various reactions, the reaction steps for controlling the production or digestion of the product could be obtained. The main source of ammonia production was pyrolysis of coal followed by steam reforming reaction of fixed carbon. The rate of ammonia contribution from ammonia synthesis was extremely low and could be ignored. The consumption path of ammonia was the decomposition reaction of ammonia though its rate was also slow. The pyrolysis reaction of coal was the main source of hydrogen sulfide, followed by the steam reforming reaction of fixed carbon. The difference of the concentration and reactivity between organic sulfur and inorganic sulfur caused the difference in the generation source of hydrogen sulfide in early and late stage of the gasification. The kinetic model can predict not only the production of hydrogen, methane, carbon dioxide, carbon monoxide, ammonia and hydrogen sulfide under different operating conditions, but also the products for different coal types, which may provide a theoretical basis for the targeted regulation of nitrogen and sulfur elements in supercritical water.
•Experiments for SCWG of coal were carried out in quartz tube reactors.•A kinetic model including N and S elements for SCWG of coal was developed.•The generation paths and reaction rates of NH3 and H2S were investigated.•The kinetic model has a good universality for different coal types.
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