Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
4,909
result(s) for
"Tan, Dong"
Sort by:
Optimization of food deprivation and sucrose preference test in SD rat model undergoing chronic unpredictable mild stress
Background The chronic unpredictable mild stress (CUMS) model has long been considered the best model for exploring the pathophysiological mechanisms underlying depression. However, there are no widely recognised standards for strategies for modeling and for behavioral testing. The present study aimed to optimize the protocols for food deprivation and the sucrose preference test (SPT) for the CUMS model. Methods We first evaluated the effects of different long periods of food deprivation on the body weight of Sprague Dawley (SD) rats by testing food deprivation for 24 hours (8:00‐8:00+), food deprivation for 12 hours during the daytime (8:00‐20:00) and food deprivation for 12 hours at night (20:00‐8:00+). Next, we established a SD rat CUMS model with 15 different stimulations, and used body weight measurement, SPT, forced swim test (FST), open field test (OFT) and Morris water maze (MWM) test to verify the success of the modeling. In the SPT, consumption of sucrose and pure water within 1 and 12 hours was measured. Results Twelve hours of food deprivation during the daytime (8:00‐20:00) had no effect on body weight, while 12 hours of food deprivation at night (20:00‐8:00+) and 24 hours of food deprivation (8:00‐8:00+) significantly reduced the mean body weight of the SD rats. When SPT was used to verify the successful establishment of the CUMS rat model, sucrose consumption measured within 12 hours was less variable than that measured within 1 hour. Conclusions Twelve hours of food deprivation in the daytime (8:00‐20:00) may be considered a mild stimulus for the establishment of a CUMS rat model. Measuring sucrose consumption over 12 hours is recommended for SPT.
Journal Article
Carbonic Fluids Drive Continental Carbon Cycling as Revealed by the Geochemistry of the Eclogite‐Garnet Peridotite Interface
Subduction zones regulate Earth's carbon distribution, yet the mechanism of carbon transfer from continental crust to mantle remains elusive. We examined an eclogite‐garnet peridotite interface from the Chinese Continental Scientific Drilling Program in the Sulu orogen, representing the slab–mantle wedge boundary formed during continental subduction. Whole‐rock magnesium (Mg) isotopic and major‐trace element data, together with in situ mineral analyses, identify the presence of carbonic fluids characterized by notably light Mg isotopic compositions (−0.54 to −0.36‰) and elevated Ca, Mg, Sr, and rare earth elements contents. These fluids, generated by slab decarbonation during prograde metamorphism, mobilized carbon from the subducted crust and enriched the mantle wedge. Modeling indicates that continental subduction rivals oceanic systems in transporting carbon to mantle. However, the paucity of mantle‐derived magmatism limits carbon return, promoting long‐term retention of continental carbon in mantle and establishing continental subduction as a major sink in the global carbon budget.
Journal Article
Supercritical fluid in deep subduction zones as revealed by multiphase fluid inclusions in an ultrahigh-pressure metamorphic vein
Due to their low viscosity, high mobility, and high element contents, supercritical fluids are important agents in the cycling of elements. However, the chemical composition of supercritical fluids in natural rocks is poorly understood. Here, we investigate well-preserved primary multiphase fluid inclusions (MFIs) from an ultrahigh-pressure (UHP) metamorphic vein of the Bixiling eclogite in Dabieshan, China, thus providing direct evidence for the components of supercritical fluid occurring in a natural system. Via the 3D modeling of MFIs by Raman scanning, we quantitatively determined the major composition of the fluid trapped in the MFIs. Combined with the peak-metamorphic pressure–temperature conditions and the cooccurrence of coesite, rutile, and garnet, we suggest that the trapped fluids in the MFIs represent supercritical fluids in a deep subduction zone. The strong mobility of the supercritical fluids with respect to carbon and sulfur suggests that such fluids have profound effects on global carbon and sulfur cycling.
Journal Article
In situ interface engineering for probing the limit of quantum dot photovoltaic devices
Quantum dot (QD) photovoltaic devices are attractive for their low-cost synthesis, tunable band gap and potentially high power conversion efficiency (PCE). However, the experimentally achieved efficiency to date remains far from ideal. Here, we report an in-situ fabrication and investigation of single TiO2-nanowire/CdSe-QD heterojunction solar cell (QDHSC) using a custom-designed photoelectric transmission electron microscope (TEM) holder. A mobile counter electrode is used to precisely tune the interface area for in situ photoelectrical measurements, which reveals a strong interface area dependent PCE. Theoretical simulations show that the simplified single nanowire solar cell structure can minimize the interface area and associated charge scattering to enable an efficient charge collection. Additionally, the optical antenna effect of nanowire-based QDHSCs can further enhance the absorption and boost the PCE. This study establishes a robust ‘nanolab’ platform in a TEM for in situ photoelectrical studies and provides valuable insight into the interfacial effects in nanoscale solar cells.
Journal Article
The application of desymmetric enantioselective reduction of cyclic 1,3-dicarbonyl compounds in the total synthesis of terpenoid and alkaloid natural products
The desymmetric enantioselective reduction of cyclic 1,3-dicarbonyl compounds is a powerful tool for the construction of ring systems bearing multiple stereocenters including all-carbon quaternary stereocenters, which are widely useful chiral building blocks for the total synthesis of structurally complex natural products. On the other hand, terpenoids and alkaloids, with their intricate and diverse skeletal frameworks as well as the broad range of biological activities, have long been a major focus for synthetic chemists. Over the past fifteen years, significant progress has been made in the total synthesis of complex terpenoid and alkaloid natural products by strategically applying desymmetric enantioselective reduction. Advance before 2016 in this area has been overviewed in an elegant review article. Since then, a series of more challenging terpenoid and alkaloid natural products have been synthesized utilizing a desymmetric enantioselective reduction strategy of cyclic 1,3-dicarbonyl compounds as a key transformation. This review will summarize the application of this strategy in the total synthesis of terpenoid and alkaloid natural products from the year 2016 to 2025. We first focus on the synthesis of several terpenoids and alkaloids through the desymmetric enantioselective reduction of five-membered cyclic 1,3-dicarbonyl compounds. Subsequently, the utilization of six-membered cyclic 1,3-dicarbonyl compounds for the synthesis of some terpenoids natural products is described.
Journal Article
Dual-quartet phosphorescent emission in the open-shell M1Ag13 (M = Pt, Pd) nanoclusters
Dual emission (DE) in nanoclusters (NCs) is considerably significant in the research and application of ratiometric sensing, bioimaging, and novel optoelectronic devices. Exploring the DE mechanism in open-shell NCs with doublet or quartet emissions remains challenging because synthesizing open-shell NCs is difficult due to their inherent instability. Here, we synthesize two dual-emissive M
1
Ag
13
(PFBT)
6
(TPP)
7
(M = Pt, Pd; PFBT = pentafluorobenzenethiol; TPP = triphenylphosphine) NCs with a 7-electron open-shell configuration to reveal the DE mechanism. Both NCs comprise a crown-like M
1
Ag
11
kernel with Pt or Pd in the center surrounded by five PPh
3
ligands and two Ag(SR)
3
(PPh
3
) motifs. The combined experimental and theoretical studies revealed the origin of DE in Pt
1
Ag
13
and Pd
1
Ag
13
. Specifically, the high-energy visible emission and the low-energy near-infrared emission arise from two distinct quartet excited states: the core-shell charge transfer and core-based states, respectively. Moreover, PFBT ligands are found to play an important role in the existence of DE, as its low-lying
π
* levels result in energetically accessible core-shell transitions. This novel report on the dual-quartet phosphorescent emission in NCs with an open-shell electronic configuration advances insights into the origin of dual-emissive NCs and promotes their potential application in magnetoluminescence and novel optoelectronic devices.
Exploring the dual-emission mechanism in open-shell nanoclusters with doublet or quartet emissions remains challenging. Here, the authors reveal the origin of dual-quartet phosphorescent emission in the open-shell M1Ag13 (M = Pt, Pd) nanoclusters.
Journal Article
Supporting Tremor Rehabilitation Using Optical See-Through Augmented Reality Technology
Tremor is a movement disorder that significantly impacts an individual’s physical stability and quality of life, and conventional medication or surgery often falls short in providing a cure. Rehabilitation training is, therefore, used as an auxiliary method to mitigate the exacerbation of individual tremors. Video-based rehabilitation training is a form of therapy that allows patients to exercise at home, reducing pressure on rehabilitation institutions’ resources. However, it has limitations in directly guiding and monitoring patients’ rehabilitation, leading to an ineffective training effect. This study proposes a low-cost rehabilitation training system that utilizes optical see-through augmented reality (AR) technology to enable tremor patients to conduct rehabilitation training at home. The system provides one-on-one demonstration, posture guidance, and training progress monitoring to achieve an optimal training effect. To assess the system’s effectiveness, we conducted experiments comparing the movement magnitudes of individuals with tremors in the proposed AR environment and video environment, while also comparing them with standard demonstrators. Participants wore a tremor simulation device during uncontrollable limb tremors, with tremor frequency and amplitude calibrated to typical tremor standards. The results showed that participants’ limb movement magnitudes in the AR environment were significantly higher than those in the video environment, approaching the movement magnitudes of the standard demonstrators. Hence, it can be inferred that individuals receiving tremor rehabilitation in the AR environment experience better movement quality than those in the video environment. Furthermore, participant experience surveys revealed that the AR environment not only provided a sense of comfort, relaxation, and enjoyment but also effectively guided them throughout the rehabilitation process.
Journal Article
Sulfur-enriched sub-arc fluids drive deep sulfur cycling in subduction zones
Arc magmas are enriched in sulfur relative to mid-ocean ridge basalts, commonly attributed to slab-derived sulfur inputs during subduction. However, the contribution of slab fluids remains debated because sulfur concentrations in sub-arc fluids have not been directly measured. Here we quantify sulfur in slab-derived fluids preserved as multiphase fluid inclusions composed of H
2
O, calcite, and chalcopyrite in omphacite from ultrahigh-pressure eclogites in the Sumdo orogenic belt. Three-dimensional Raman spectroscopy reveals high sulfur concentrations averaging ~6 wt.%. Mass-balance calculations indicate that such fluids can efficiently enrich the mantle wedge and supply up to ~70% of the sulfur emitted by arc volcanism. We further suggest that chalcopyrite formed through post-entrapment reduction of oxidized sulfur species by host omphacite, followed by precipitation with co-entrapped copper and iron. Our findings identify sub-arc depths as a critical window for slab sulfur release and provide key constraints on deep sulfur cycling and copper mobilization in arc systems.
Three-dimensional Raman modelling of multiphase inclusions in Sumdo eclogites reveals sulfur rich slab-derived fluids at sub-arc depths, providing direct constraints on deep sulfur cycling and copper mobilization in subduction zones.
Journal Article
A hybrid linear dynamic absorber and nonlinear energy sink for broadband absorption of a circular ring
Nonlinear energy sinks (NES) have been shown to have broadband absorption for multiple modes. Furthermore, linear dynamic absorbers (LDA) often only operate effectively within located frequency ranges and are unable to achieve broadband absorption. Therefore, this manuscript first proposed using a hybrid LDA and NES to design the circular ring absorption system. Compared with LDA, broadband absorption could be achieved through configuring and tuning linear stiffness. Both the linear and nonlinear stiffnesses are introduced by adding vertical and horizontal springs. The linear and nonlinear stiffness effects on the circular ring absorption system are investigated simultaneously. The dynamic model of the circular ring absorption system with hybrid LDA and NES is constructed, and the approximate analytical solution is obtained using the harmonic balance analysis. The expressions of frequency response and force transmissibility are given, and the analytical results are verified numerically. By comparing the amplitude-frequency response curves of the circular ring with LDA only, NES only, and a hybrid LDA and NES, it is confirmed that a hybrid LDA and NES can better control the forced vibration of the circular ring absorption system. Hybrid LDA and NES were shown to suppress main resonance peaks of the circular ring absorption system, making the device resistant to misalignments. In a linear system, this can only be achieved by resonance matching, so a hybrid LDA and NES have the same effect as adding multiple linear absorbers. Some properties of damping, nonlinear stiffness, and mass ratios in a hybrid LDA and NES are investigated. These parameters determine the specific shape of the force transmissibility curve of the ring absorption system. It is found that a proper increase in the mass ratio of the hybrid LDA and NES can obtain a better vibration reduction effect; adjusting the damping ratio and nonlinear stiffness ratio of the hybrid LDA and NES can improve the vibration reduction effect to a certain extent. Based on the analysis of the parameters effects of hybrid LDA and NES on vibration control, the parameters of hybrid LDA and NES are compared. The analysis of the results demonstrates that by selecting reasonable damping, nonlinear stiffness, and mass ratios, the frequency band of the circular ring absorption system can be broadened. Finally, an experiment is performed to validate the correctness of the proposed method.
Journal Article