The combined catalytic systems derived from organocatalysts and transition metals exhibit powerful activation and stereoselective-control abilities in asymmetric catalysis. This work describes a ...highly efficient chiral aldehyde-nickel dual catalytic system and its application for the direct asymmetric α-propargylation reaction of amino acid esters with propargylic alcohol derivatives. Various structural diversity α,α-disubstituted non-proteinogenic α-amino acid esters are produced in good-to-excellent yields and enantioselectivities. Furthermore, a stereodivergent synthesis of natural product NP25302 is achieved, and a reasonable reaction mechanism is proposed to illustrate the observed stereoselectivity based on the results of control experiments, nonlinear effect investigation, and HRMS detection.
As a new wastewater biological nitrogen removal process, anammox and partial denitrification coupling not only plays a significant role in the nitrogen cycle, but also holds high engineering ...application value. Because anammox and some denitrifying bacteria are coupled under harsh living conditions, certain operating conditions and mechanisms of the coupling process are not clear; thus, it is more difficult to control the process, which is why the process has not been widely applied. This paper analyzes the research focusing on the coupling process in recent years, including anammox and partial denitrification coupling process inhibitors such as nitrogen (NH
4
+
, NO
2
−
), organics (toxic and non-toxic organics), and salts. The mechanism of substrate removal in anammox and partial denitrification coupling nitrogen removal is described in detail. Due to the differences in process methods, experimental conditions, and sludge choices between the rapid start-up and stable operation stages of the reactor, there are significant differences in substrate inhibition. Multiple process parameters (such as pH, temperature, dissolved oxygen, redox potential, carbon-to-nitrogen ratio, and sludge) can be adjusted to improve the coupling of anammox and partial denitrification to modify nitrogen removal performance.
As a new wastewater biological nitrogen removal process, anammox and partial denitrification coupling not only plays a significant role in the nitrogen cycle, but also holds high engineering application value.
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IJS, KILJ, NUK, UL, UM, UPUK
Mouse clinical trials (MCTs) are becoming wildly used in pre-clinical oncology drug development, but a statistical framework is yet to be developed. In this study, we establish such as framework and ...provide general guidelines on the design, analysis and application of MCTs.
We systematically analyzed tumor growth data from a large collection of PDX, CDX and syngeneic mouse tumor models to evaluate multiple efficacy end points, and to introduce statistical methods for modeling MCTs.
We established empirical quantitative relationships between mouse number and measurement accuracy for categorical and continuous efficacy endpoints, and showed that more mice are needed to achieve given accuracy for syngeneic models than for PDXs and CDXs. There is considerable disagreement between methods on calling drug responses as objective response. We then introduced linear mixed models (LMMs) to describe MCTs as clustered longitudinal studies, which explicitly model growth and drug response heterogeneities across mouse models and among mice within a mouse model. Case studies were used to demonstrate the advantages of LMMs in discovering biomarkers and exploring drug's mechanisms of action. We introduced additive frailty models to perform survival analysis on MCTs, which more accurately estimate hazard ratios by modeling the clustered mouse population. We performed computational simulations for LMMs and frailty models to generate statistical power curves, and showed that power is close for designs with similar total number of mice. Finally, we showed that MCTs can explain discrepant results in clinical trials.
Methods proposed in this study can make the design and analysis of MCTs more rational, flexible and powerful, make MCTs a better tool in oncology research and drug development.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Simple steps, complex result: Consecutive organo‐catalyzed reactions of 3‐indolylmethanol compounds with aldehydes and N‐protected indoles lead to the formation of structurally complex ...cyclopentabindoles (see scheme, Bn=benzyl). These one‐pot multistep reactions have a broad substrate scope and give the products in high yields, and with excellent diastereoselectivities and enantioselectivities.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
In this paper, we give some necessary and sufficient conditions for a family of linear bounded operators to be a dual
K
-g-Bessel sequence of a given
K
-g-frame and, particularly, we determine a ...method to examine the uniqueness of the dual
K
-g-Bessel sequences associated with a
K
-g-frame. We also study the redundancy of
K
-g-frames and some new properties of exact
K
-g-frames are presented.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Use of a phase change material (PCM)-based heat sink in transient thermal management of plastic quad flat package (QFP) electronic devices was investigated experimentally and numerically. Results ...show that increased power inputs enhance the melting rate as well as the thermal performance of the PCM-based heat sinks until the PCM is fully melted. A three-dimensional computational fluid dynamics model was proposed to simulate the problem and demonstrated good agreement with experimental data. Results indicate the potential for PCM-based heat sinks for use in intermittent-use devices.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Abstract
Optical nanoantennas have attracted significant attention over the past decades, owing to their exceptional capabilities in terms of light manipulation and versatile optical applications. ...Recently, active nanoantennas have been developed by introducing phase change materials, to achieve specific tunable electromagnetic responses. However, most of these attempts only function with ‘ON’/‘OFF’ states or switch in a few discrete states, significantly restricting the application in dynamic tunability. Thus far, the continuous and reversible modulation of optical nanoantennas has not been sufficiently explored. In this article, we experimentally demonstrate a continuously and reversibly electro-tunable optical nanoantenna, by integrating an asymmetric gold nanodisk dimer array with a vanadium dioxide (VO
2
) film and graphene thin film. By accurately controlling the applied electrical current, the Joule heat generated in the graphene film excites the metal-insulator phase transition of VO
2
, and the refractive index of VO
2
exhibits a relatively large variation. When VO
2
is in the insulating phase, we observe an apparent resonance dip in the reflection spectrum, which is attributed to a hybrid mode originating from the gap plasmon in the dimers and localized surface plasmon (LSP) resonance excited at the edge of the nanodisks. Meanwhile, owing to the coupling between two asymmetric LSP resonances in the neighboring nanodisks, the reflected peak based on the Fano effect is realized. However, once VO
2
is in the metallic phase, the hybrid mode becomes weaker and red-shifted, and the Fano effect disappears. Thereafter, the continuous and reversible electro-modulation of the nanoantenna features, including the resonant wavelength, resonant intensity, and quality factors (
Q
), are experimentally verified in the optical communication region, by varying the applied electrical current in the hybrid structure. To further increase the modulation range of these properties, we scan the gap size and structural asymmetry parameter of the nanodisk dimer. The results show that, with a smaller gap size, the resonant intensity of the nanoantenna is stronger. When the structural asymmetry parameter increases, the resonant wavelength is redshifted. We expect that such continuously and reversibly electro-tunable nanoantennas will stimulate various applications in optical communication systems, tunable photoelectric sensors, and beyond.
Metal-halide perovskites have been hailed as remarkable materials for photovoltaic devices and, recently, their star has also been on the rise in optoelectronics and photonics. In particular, the ...optical properties of a metal-halide perovskite can be widely manipulated once its bulk structure has been reduced to a low-dimensional structure, allowing multiple functionalities of light generation, emission, transmission, and detection to be realized in one material. In this paper, we highlight the recent advances in the synthesis of low-dimensional metal-halide perovskites and their unique properties as well as their novel optoelectronic and photonic applications. It is anticipated that this review can serve as an overview and evaluation of state-of-the-art synthesis techniques as well as nanoscale optoelectronics and photonics based on low-dimensional perovskite nanocrystals.
This feature article provides an overview of synthesis, properties and applications of low-dimensional perovskites.
Aim
To explore the sleep quality among Chinese nurses and identify the association between night shift and sleep quality and health.
Background
Chinese nurses have many night shifts; the effect of it ...regarding nurses' sleep quality and health is still not being explored.
Methods
This was a cross‐sectional study. There were 3,206 nurse participants. The participants self‐completed a sociodemographic questionnaire, the Pittsburgh Sleep Quality Index (PSQI) and the Cornell Medical Index (CMI).
Results
Night shift nurses demonstrated relatively worse sleep quality (55.1%) and more health problems (20.7%). Night shift work was significantly associated with poor sleep quality (β = 0.96, confidence interval CI = 0.67–1.26) and poor health (β = 2.01, CI = 0.15–3.88). Except for sleep medication (β = 0.02, CI = −0.01, 0.05) and psychological health (β = 0.38, CI = −0.27, 1.03), night shift work was significantly associated with other PSQI domains and physical health.
Conclusion
Night shift work was a risk factor for nurses' sleep quality and health. Night shift nurses have more sleep disorders and physical health problems.
Implications for Nursing Management
Nurse managers should pay attention to the impact of shift work on nurses’ sleep quality and health and reform the rotating shift work system to improve nurses’ occupational health.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK, VSZLJ
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