More heterogeneous oil reservoir in the process of waterflooding oil field, reasonable water injection is to improve the recovery efficiency, an important means to slow down the natural decline, ...strengthen the daily management of injection Wells, according to the influencing factors of injection Wells anomalies corresponding measures, improve the water time, improve the qualified rate of water injection, truly underground “good enough water and injection water” goal, It is the most economical and effective way to improve oil recovery.
To the best of our knowledge, bridgehead carbon benzofused-bridged ring systems have previously not been accessible to the synthetic community. Here, we describe a formal type-II 4 + 4 cycloaddition ...approach that provides fully sp
-carbon embedded anti-Bredt bicyclo5.3.1 skeletons through the Rh-catalyzed C
-C
activation of benzocyclobutenones (BCBs) and their coupling with pedant dienamides. Variously substituted dienamides have been coupled with BCBs to provide a range of complex bicyclo5.3.1 scaffolds (>20 examples, up to 89% yield). The bridged rings were further converted to polyfused hydroquinoline-containing tetracycles via a serendipitously discovered transannular 1,5-hydride shift/Prins-like cyclization/Schmidt rearrangement cascade.
Machine learning has been heavily researched and widely used in many disciplines. However, achieving high accuracy requires a large amount of data that is sometimes difficult, expensive, or ...impractical to obtain. Integrating human knowledge into machine learning can significantly reduce data requirement, increase reliability and robustness of machine learning, and build explainable machine learning systems. This allows leveraging the vast amount of human knowledge and capability of machine learning to achieve functions and performance not available before and will facilitate the interaction between human beings and machine learning systems, making machine learning decisions understandable to humans. This paper gives an overview of the knowledge and its representations that can be integrated into machine learning and the methodology. We cover the fundamentals, current status, and recent progress of the methods, with a focus on popular and new topics. The perspectives on future directions are also discussed.
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•Integrating knowledge into machine learning delivers superior performance•Knowledge is categorized and its representations are presented•Various methods to bridge human knowledge and machine learning are shown•Suggestions on approaches and perspectives on future research directions are provided
Computer Science; Artificial Intelligence; Human-Centered Computing
Human catechol-O-methyltransferase, a key enzyme related to neurotransmitter metabolism, catalyses a methyl transfer from S-adenosylmethionine to catechol. Although extensive studies aim to ...understand the enzyme mechanisms, the connection of protein dynamics and enzyme catalysis is still not clear. Here, W38in (Trp143Phe) and W38in/Y68A (Trp143Phe with Tyr68Ala) mutants were carried out to study the relationship of dynamics and catalysis in nano-second timescale using time-resolved fluorescence lifetimes and Stokes shifts in various solvents. The comprehensive data implied the mutant W38in/Y68A with lower activity is more rigid than the 'WT'-W38in, suggesting the importance of flexibility at residue 38 to maintain the optimal catalysis.
A new power supply rejection (PSR) based enhancer with small and stable dropout voltage is presented in this work. It is implemented using TSMC-40 nm process technology and powered by 1.2 V supply ...voltage. A number of circuit techniques are proposed in this work. These include the temperature compensation for Level-Shifted Flipped Voltage Follower (LSFVF) and the Complementary-To-Absolute Temperature (CTAT) current reference. The typical output voltage and dropout voltage of the enhancer is 1.1127 V and 87.3 mV, respectively. The Monte-Carlo simulation of this output voltage yields a mean T.C. of 29.4 ppm/°C from −20 °C and 80 °C. Besides, the dropout voltage has been verified with good immunity against Process, Temperature and Process (PVT) variation through the worst-case simulation. Consuming only 4.75 μA, the circuit can drive load up to 500 μA to yield additional PSR improvement of 36 dB and 20 dB of PSR at 1 Hz and 1 MHz, respectively for the sensor circuit of interest. This is demonstrated through the application of an enhancer on the instrumentation Differential Difference Amplifier (DDA) for sensing floating bridge sensor signal. The comparative Monte-Carlo simulation results on a respective DDA circuit have revealed that the process sensitivity of output voltage of this work has achieved 14 times reduction in transient metrics with respect to that of the conventional counterpart over the operation temperature range in typical operation condition. Due to simplicity without voltage reference and operational amplifier(s), low power and small consumption of supply voltage headroom, the proposed work is very useful for supply noise sensitive analog or sensor circuit applications.
The association between non-alcoholic fatty liver disease (NAFLD) and osteoarthritis (OA) has not been well elucidated. The aim of the present study was to investigate the association between NAFLD ...and OA in the US adults.
A cross-sectional study was performed on participants in the 2017-2018 National Health and Nutrition Examination Survey (NHANES) cycle. NAFLD was defined by the vibration-controlled transient elastography. The diagnosis of OA was based on self-reported data. Weighted multiple logistic regression models and stratified analyses were performed to explore the relationship and verify the stability of the conclusions. Sensitivity analysis using multiple imputation for missing data and propensity score matching (PSM) were performed.
In total, 2622 participants Male: 1260 (47.8%) were included in this study with a mean age of 48.1 years old (95% CI, 46.6-49.6 years old), containing 317 (12.8%) OA patients and 1140 NAFLD patients (41.5%). A logistic regression indicated a significant association between NAFLD and OA without adjustment odds ratio (OR) = 2.05; 95% CI, 1.52-2.78. The association remained stable after adjustment for covariates (OR = 1.72; 95% CI, 1.26-2.34). Sensitivity analysis of missing data with multiple interpolation and PSM found similar results. A significant and consistent association of NAFLD with OA was still observed in each subgroup stratified by age and metabolic syndrome (MetS). Stratified by sex, obesity, and sensitivity c-reactive protein (hs-CRP) category, a statistically significant association was only shown in females, those without obesity, and those without hyper hs-CRP. The results illustrated that the relationship between NAFLD and OA was stable in all subgroups and had no interaction.
NAFLD was positively correlated with OA. Given the current pandemic of NAFLD and OA, clinicians should screen for NAFLD in arthritis patients and intervene early.
Mechanistic studies promote scientific development from phenomena to theories. Aggregation-induced emission(AIE), as an unusual photophysical phenomenon, builds the bridge between molecular science ...and aggregate mesoscience. With the twenty-year development of AIE, restriction of intramolecular motion(RIM) has been verified as the working mechanism of AIE effect. In this review, these mechanistic works about RIM are summarized from experimental and theoretical perspectives. Thereinto, the experimental studies are introduced from three parts: external rigidification, structural modification and structural characterization. In the theoretical part, calculations on the low-frequency motion of AIEgens have been performed to prove the RIM mechanism. By virtue of the theoretical calculations, some new mechanisms are proposed to supplement the RIM, such as restriction of access to conical intersection, suppression of Kasha transition, restriction of access to dark state, etc. It is foreseeable that the RIM mechanism will unify the photophysical theories for both molecules and aggregates, and inspire more progress in aggregate science.
Employee resilience is of great significance for organizations to resist pressures, overcome crises, and achieve sustainable development. However, existing research has largely failed to explore its ...situational triggers. Drawing on social information processing theory and social exchange theory, a cross-level study was conducted to theorize the underlying mechanisms through which authentic leadership facilitates employee resilience. Based on a two-wave time-lagged design, the data were obtained from 85 team leaders and 417 employees in China. The results of the cross-level model showed that authentic leadership was positively related to employee resilience. Perceived insider status and error management climate both played a partial mediating role in linking authentic leadership and employee resilience. Error management climate positively moderated the relationship between perceived insider status and employee resilience. This paper not only contributes to revealing the cross-level effect of authentic leadership on employee resilience but also provides some managerial practices.
Black phosphorus (BP) is a little-studied but promising next-generation anode material for high-energy density Li-ion and Na-ion batteries. To understand the relationship between material property ...and electrochemical performance, black phosphorus-graphite (BP-G) composite materials are synthesized with two different BP-G molar ratios. This study demonstrates that the crystal structure and PC bond of BP-G composites are affected by the BP-G molar ratio, which are directly correlated to cycle stability and the lithiation/delithiation process. BP0.9G1 shows a medium-range ordered structure, retaining some features of BP and having fewer or weaker PC bonds. In contrast, BP0.3G1 has an amorphous-like structure with robust PC bonds, which is helpful in withstanding the large volume change upon lithiation or delithiation. As a result, fracture and pulverization of particles, which are clearly seen in BP0.9G1 electrode, are scarcely observed in the cycled BP0.3G1 electrode. The possibility of mechanical failure in the BP-based electrode induced by BP's hydrophilic nature and the formation of Cu3P is also discussed. This work not only contributes to improving the current understanding of phosphorus-based anodes, but also provides direct evidence of fracture and pulverization of BP particles during cycling.
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•BP-G composition determines the structural stability of BP-G composite.•Identified relation between crystal structure and performance of BP-G composite.•Presented direct evidence of mechanical degradation of BP-G composite.•Oxygen, moisture and formation of Cu3P may also contribute to BP-G degradation.
Phototheranostic agents have thrived as promising tools for cancer theranostics because of the integration of sensitive in situ fluorescence imaging and effective multi‐model synergistic therapy. ...However, how to manipulate the intangible photon energy transfer to balance the competitive radiative and nonradiative processes is still challenging. Although numerous phototheranostic molecules are reported, their complicated molecular design and tedious synthesis often stumble further their development. Herein, three simple molecules with electron donating−accepting structures are developed. The electron acceptor engineering on molecules by introducing acridinium unit gives rise to TPEDCAc with aggregation‐induced second near‐infrared emission (AIE NIR‐II), high reactive oxygen species generation capability, and excellent photothermal conversion efficiency (44.8%) due to the drastic intramolecular motion of large acridinium rotor and balanced AIE effect. Experimental analysis and calculation on the controlled molecules suggested that large torsional angle and the strong electron‐withdrawing ability of the acridinium unit are keys for NIR‐II emission and balanced photodynamic/photothermal conversion. Impressively, the positively charged TPEDCAc shows mitochondria‐targeting capability and high performance in in vivo multi‐modal cancer theranostics under NIR laser irradiation. Hence, this work not only provides a single NIR‐II AIE‐based multi‐modal cancer theranostic system but inspires new insights into future development of new theranostic platforms.
An acceptor engineering strategy for modulating intramolecular motion is proposed for developing phototheranostic agents. By manipulating torsional angle and electron‐withdrawing ability of acceptors, balance of competing radiative and nonradiative processes can be achieved to afford TPEDCAc with aggregation‐induced second near‐infrared emission, high reactive oxygen species generation capability, and excellent photothermal conversion efficiency for developing a promising multi‐model cancer phototheranostic system.
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