Size-dependent photoluminescence blinking mechanisms and volume scaling of biexciton Auger recombination in single CsPbI3 perovskite quantum dots.

Determining the correlation between the size of a single quantum dot (QD) and its photoluminescence (PL) properties is a challenging task. In the study, we determine the size of each QD by measuring its absorption cross section, which allows for accurate investigation of size-dependent PL blinking mechanisms and volume scaling of the biexciton Auger recombination at the single-particle level. A significant correlation between the blinking mechanism and QD size is observed under low excitation conditions. When the QD size is smaller than their Bohr diameter, single CsPbI3 perovskite QDs tend to exhibit BC-blinking, whereas they tend to exhibit Auger-blinking when the QD size exceeds their Bohr diameter. In addition, by extracting bright-state photons from the PL intensity trajectories, the effects of QD charging and surface defects on the biexcitons are effectively reduced. This allows for a more accurate measurement of the volume scaling of biexciton Auger recombination in weakly confined CsPbI3 perovskite QDs at the single-dot level, revealing a superlinear volume scaling (τXX,Auger ∝ σ1.96).

Anomalous layer-dependent photoluminescence spectra of supertwisted spiral WS2.

Twisted stacking of two-dimensional materials with broken inversion symmetry, such as spiral MoTe2 nanopyramids and supertwisted spiral WS2, emerge extremely strong second- and third-harmonic generation. Unlike well-studied nonlinear optical effects in these newly synthesized layered materials, photoluminescence (PL) spectra and exciton information involving their optoelectronic applications remain unknown. Here, we report layer- and power-dependent PL spectra of the supertwisted spiral WS2. The anomalous layer-dependent PL evolutions that PL intensity almost linearly increases with the rise of layer thickness have been determined. Furthermore, from the power-dependent spectra, we find the power exponents of the supertwisted spiral WS2 are smaller than 1, while those of the conventional multilayer WS2 are bigger than 1. These two abnormal phenomena indicate the enlarged interlayer spacing and the decoupling interlayer interaction in the supertwisted spiral WS2. These observations provide insight into PL features in the supertwisted spiral materials and may pave the way for further optoelectronic devices based on the twisted stacking materials.

Three-dimensional quantum imaging of dynamic targets using quantum compressed sensing.

Quantum imaging based on entangled light sources exhibits enhanced background resistance compared to conventional imaging techniques in low-light conditions. However, direct imaging of dynamic targets remains challenging due to the limited count rate of entangled photons. In this paper, we propose a quantum imaging method based on quantum compressed sensing that leverages the strong correlation characteristics of entangled photons and the randomness inherent in photon pair generation and detection. This approach enables the construction of a compressed sensing system capable of directly imaging high-speed dynamic targets. The results demonstrate that our system successfully achieves imaging of a target rotating at a frequency of 10 kHz, while maintaining an impressive data compression rate of 10-6. This proposed method introduces a pioneering approach for the practical implementation of quantum imaging in real-world scenarios.

DnaK duplication and specialization in bacteria correlates with increased proteome complexity.

The chaperone 70 kDa heat shock protein (Hsp70) is important for cells from bacteria to humans to maintain proteostasis, and all eukaryotes and several prokaryotes encode Hsp70 paralogs. Although the mechanisms of Hsp70 function have been clearly illuminated, the function and evolution of Hsp70 paralogs is not well studied. DnaK is a highly conserved bacterial Hsp70 family. Here, we show that dnaK is present in 98.9% of bacterial genomes, and 6.4% of them possess two or more DnaK paralogs. We found that the duplication of dnaK is positively correlated with an increase in proteomic complexity (proteome size, number of domains). We identified the interactomes of the two DnaK paralogs of Myxococcus xanthus DK1622 (MxDnaKs), which revealed that they are mostly nonoverlapping, although both prefer α and ß domain proteins. Consistent with the entire M. xanthus proteome, MxDnaK substrates have both significantly more multi-domain proteins and a higher isoelectric point than that of Escherichia coli, which encodes a single DnaK homolog. MxDnaK1 is transcriptionally upregulated in response to heat shock and prefers to bind cytosolic proteins, while MxDnaK2 is downregulated by heat shock and is more associated with membrane proteins. Using domain swapping, we show that the nucleotide-binding domain and the substrate-binding ß domain are responsible for the significant differences in DnaK interactomes, and the nucleotide binding domain also determines the dimerization of MxDnaK2, but not MxDnaK1. Our work suggests that bacterial DnaK has been duplicated in order to deal with a more complex proteome, and that this allows evolution of distinct domains to deal with different subsets of target proteins.IMPORTANCEAll eukaryotic and ~40% of prokaryotic species encode multiple 70 kDa heat shock protein (Hsp70) homologs with similar but diversified functions. Here, we show that duplication of canonical Hsp70 (DnaK in prokaryotes) correlates with increasing proteomic complexity and evolution of particular regions of the protein. Using the Myxococcus xanthus DnaK duplicates as a case, we found that their substrate spectrums are mostly nonoverlapping, and are both consistent to that of Escherichia coli DnaK in structural and molecular characteristics, but show differential enrichment of membrane proteins. Domain/region swapping demonstrated that the nucleotide-binding domain and the ß substrate-binding domain (SBDß), but not the SBDα or disordered C-terminal tail region, are responsible for this functional divergence. This work provides the first direct evidence for regional evolution of DnaK paralogs.

Perceptions of barriers to and facilitators of exercise rehabilitation in adults with lung transplantation: a qualitative study in China.

BACKGROUND: Exercise is crucial for pulmonary rehabilitation and improving the prognosis of lung transplantation (LTx) patients. However, many LTx patients in China have low exercise tolerance and compliance, and the reasons behind these challenges have not been fully elucidated. Therefore, this qualitative research aims to identify the barriers to and facilitators of exercise rehabilitation in LTx patients. METHODS: From January to July 2023, 15 stable LTx patients were recruited and participated in in-depth, semi-structured, face-to-face interviews at Henan Provincial People's Hospital. The interview transcripts were analyzed using the COM-B model and the Theoretical Domains Framework (TDF). RESULTS: Six general themes including 19 barriers and 14 facilitators for the exercise rehabilitation of LTx patients were identified based on the COM-B model and TDF. The barriers to exercise included physical limitations, insufficient exercise endurance, lack of knowledge, and lack of motivation. The facilitators of exercise included motivation, self-efficacy, perceived significance of exercise rehabilitation, and social support. CONCLUSION: The study offers detailed insight into the development and implementation of exercise rehabilitation intervention strategies for LTx patients. By combining COM-B model and TDF, the study provides strong evidence that active behavior change strategies are required for LTx patients to promote their participation in exercise rehabilitation. Professional support, pulmonary rehabilitation training, behavior change technology, and digital health tools are essential for strengthening the evidence system for reporting exercise efficacy and effectiveness.

LncRNA PSMA3-AS1 promotes preterm delivery by inducing ferroptosis via miR-224-3p/Nrf2 axis.

Long non-coding RNAs (lncRNAs) have a vital potential in premature delivery. This research was intended to explore PSMA3-AS1's role in premature delivery as well as its possible molecular mechanism. We enrolled 100 premature delivery patients and 100 term patients. Fetal membranes were collected. RT-qPCR was adopted for evaluating PSMA3-AS1, miRNA-224-3p, along with Nrf2 expression. Cell function experiments were implemented to clarify PSMA3-AS1 functions in human trophoblast HTR-8/SVneo cells. Rescue together with mechanistic experiments were implemented for assessing the regulatory function and interaction between miR-224-3p and PSMA3-AS1 or Nrf2 axis in human trophoblast cells. The results uncovered that PSMA3-AS1 level presented downregulation in the fetal membrane tissues and human trophoblast cells. Overexpressed PSMA3-AS1 enhanced cell proliferation but suppressed ferroptosis in human trophoblast cells. Besides, PSMA3-AS1 elevation also attenuated the LPS-induced inflammatory response and restored the LPS-induced upregulation of 20α-HSD and downregulation of progesterone (P4). Mechanistically, miR-224-3p could bind to PSMA3-AS1 and present upregulation in fetal membranes and human trophoblast cells. Notably, overexpressed miR-224-3p offset the influences of PSMA3-AS1 on human trophoblast cell proliferation and ferroptosis. Furthermore, Nrf2 was targeted by miR-224-3p. Downregulated Nrf2 offset the influences of the miR-224-3p inhibitor and induced HTR-8/SVneo dysfunction. Additionally, Nrf2 transcriptionally activated PSMA3-AS1 and GPX4. In conclusion, PSMA3-AS1 expression is low during premature delivery and overexpressing PSMA3-AS1 promotes proliferation and suppresses ferroptosis of human trophoblast cells by interacting with miR-224-3p to downregulate Nrf2. Therefore, enhancing PSMA3-AS1 expression may be a promising therapeutic strategy to prevent premature delivery.

Conversion of Photoluminescence Blinking Types in Single Colloidal Quantum Dots.

Almost all colloidal quantum dots (QDs) exhibit undesired photoluminescence (PL) blinking, which poses a significant obstacle to their use in numerous luminescence applications. An in-depth study of the blinking behavior, along with the associated mechanisms, can provide critical opportunities for fabricating high-quality QDs for diverse applications. Here the blinking of a large series of colloidal QDs is investigated with different surface ligands, particle sizes, shell thicknesses, and compositions. It is found that the blinking behavior of single alloyed CdSe/ZnS QDs with a shell thickness of up to 2 nm undergoes an irreversible conversion from Auger-blinking to band-edge carrier blinking (BC-blinking). Contrastingly, single perovskite QDs with particle sizes smaller than their Bohr diameters exhibit reversible conversion between BC-blinking and more pronounced Auger-blinking. Changes in the effective trapping sites under different excitation conditions are found to be responsible for the blinking type conversions. Additionally, changes in shell thickness and particle size of QDs have a significant effect on the blinking type conversions due to altered wavefunction overlap between excitons and effective trapping sites. This study elucidates the discrepancies in the blinking behavior of various QD samples observed in previous reports and provides deeper understanding of the mechanisms underlying diverse types of blinking.

1D Gradient-Weighted Class Activation Mapping, Visualizing Decision Process of Convolutional Neural Network-Based Models in Spectroscopy Analysis.

Being characterized by the self-adaption and high accuracy, the deep learning-based models have been widely applied in the 1D spectroscopy-related field. However, the "black-box" operation and "end-to-end" working style of the deep learning normally bring the low interpretability, where a reliable visualization is highly demanded. Although there are some well-developed visualization methods, such as Class Activation Mapping (CAM) and Gradient-weighted Class Activation Mapping (Grad-CAM), for the 2D image data, they cannot correctly reflect the weights of the model when being applied to the 1D spectral data, where the importance of position information is not considered. Here, aiming at the visualization of Convolutional Neural Network-based models toward the qualitative and quantitative analysis of 1D spectroscopy, we developed a novel visualization algorithm (1D Grad-CAM) to more accurately display the decision-making process of the CNN-based models. Different from the classical Grad-CAM, with the removal of the gradient averaging (GAP) and the ReLU operations, a significantly improved correlation between the gradient and the spectral location and a more comprehensive spectral feature capture were realized for 1D Grad-CAM. Furthermore, the introduction of difference (purity or linearity) and feature contribute in the CNN output in 1D Grad-CAM achieved a reliable evaluation of the qualitative accuracy and quantitative precision of CNN-based models. Facing the qualitative and adulteration quantitative analysis of vegetable oils by the combination of Raman spectroscopy and ResNet, the visualization by 1D Grad-CAM well reflected the origin of the high accuracy and precision brought by ResNet. In general, 1D Grad-CAM provides a clear vision about the judgment criterion of CNN and paves the way for CNN to a broad application in the field of 1D spectroscopy.

Fear of progression among postoperative patients with newly diagnosed lung cancer: a cross-sectional survey in China.

BACKGROUND: More lung cancer cases are becoming diagnosed earlier in recent years. The diagnosis is often accompanied by fear of progression (FoP). There is a clear research gap in the existing literature on FoP and the most frequent concerns in newly diagnosed lung cancer patients. OBJECTIVE: To identify the status and factors related to FoP in newly diagnosed Chinese lung cancer patients undergoing thoracoscopic lung cancer resection. METHODS: A cross-sectional design with convenience sampling was used in this study. Participants (N = 188) with newly diagnosed lung cancer (≤ 6 months) at one hospital in Zhengzhou were recruited. A demographic questionnaire, Fear of Progression Questionnaire-Short Form, Social Support Rating Scale (SSRS), Simplified Coping Style Questionnaire, and Brief Illness Perception Questionnaire were used to assess characteristics, FoP, social support, coping style, and patient illness perceptions. Multivariable logistic regression analysis was used to identify factors associated with FoP. RESULTS: The mean score of FoP was 35.39 ± 8.03. There are 56.4% of the patients (scores ≥ 34) have a clinically dysfunctional level of FoP. FoP was higher in young (18-39 years) than middle-aged patients (40-59 years) and elderly patients (≧60 years) (P = 0.004). Patients aged 40-59 years showed significantly higher fear of family-related concerns (P < 0.001), a fear of potential harm from medications (P = 0.001); Patients aged 18-39 years and 40-59 years showed significantly higher fears of work-related concerns (P = 0.012). Multiple logistic regression analyses showed that patients' age, the time from surgery and SSRS score were found to be independently associated with higher FoP. CONCLUSIONS: High FoP is a frequently reported problem among newly diagnosed lung cancer patients, especially those less than 60 years old. Professional psychoeducation, psychological interventions, and personalized support are needed for patients with a high FoP.

High frequency near-infrared up-conversion single-photon imaging based on the quantum compressed sensing.

Infrared up-conversion single-photon imaging has potential applications in remote sensing, biological imaging, and night vision imaging. However, the used photon counting technology has the problem of long integration time and sensitivity to background photons, which limit its application in real-world scenarios. In this paper, a novel passive up-conversion single-photon imaging method is proposed, in which the high frequency scintillation information of a near infrared target is captured by using the quantum compressed sensing. Through the frequency domain characteristic imaging of the infrared target, the imaging signal-to-noise ratio is significantly improved with strong background noise. In the experiment, the target with flicker frequency on the order of GHz is measured, and the signal-to-background ratio of the imaging reaches up to 1:100. Our proposal greatly improved the robustness of near-infrared up-conversion single-photon imaging and will promote its practical application.

The Geometry of Nanoparticle-on-Mirror Plasmonic Nanocavities Impacts Surface-Enhanced Raman Scattering Backgrounds.

Surface-enhanced Raman scattering (SERS) has garnered substantial attention due to its ability to achieve single-molecule sensitivity by utilizing metallic nanostructures to amplify the exceedingly weak Raman scattering process. However, the introduction of metal nanostructures can induce a background continuum which can reduce the ultimate sensitivity of SERS in ways that are not yet well understood. Here, we investigate the impact of laser irradiation on both Raman scattering and backgrounds from self-assembled monolayers within nanoparticle-on-mirror plasmonic nanocavities with variable geometry. We find that laser irradiation can reduce the height of the monolayer by inducing an irreversible change in molecular conformation. The resulting increased plasmon confinement in the nanocavities not only enhances the SERS signal, but also provides momentum conservation in the inelastic light scattering of electrons, contributing to the enhancement of the background continuum. The plasmon confinement can be modified by changing the size and the geometry of nanoparticles, resulting in a nanoparticle geometry-dependent background continuum in SERS. Our work provides new routes for further modifying the geometry of plasmonic nanostructures to improve SERS sensitivity.

The role of atmospheric conditions in the nonradiative recombination in individual CH3NH3PbI3 perovskite crystals.

Organic-inorganic metal halide perovskites have been emerging as potential candidates for lightweight photovoltaic applications in space. However, fundamental physics concerning the effect of atmosphere on the radiative and nonradiative recombination in perovskites remains far from well understood. Here, we investigate the creation and annihilation of nonradiative recombination centers in individual CH3NH3PbI3 perovskite crystals by controlling the atmospheric conditions. We find that the photoluminescence (PL) of individual perovskite crystals can be quenched upon exposure from air to vacuum, while the subsequent PL enhancement in air shows a pressure dependence. Further analysis attributes the PL decline in vacuum to the activation of nonradiative trap sites, which is likely due to the lattice distortion caused by the variation of local strain on perovskites. With a gradual increase of the air pressure, the light-assisted chemisorption of oxygen on perovskite will passivate these nonradiative trap sites while simultaneously restoring the lattice imperfection, leading to PL enhancement. The present findings suggest that placing the perovskite in an environment with moderate oxygen content can protect the material from photophysical losses that can be pronounced under inert conditions.

Optical interference effect in the hybrid quantum dots/two-dimensional materials: photoluminescence enhancement and modulation.

The optical interference effect originating from the multiple reflections between the two-dimensional (2D) materials and the substrates has been used to dramatically enhance their Raman signal. However, this effect in the hybrid structures of colloidal quantum dots (QD) coupled to 2D materials is always overlooked. Here we theoretically prove that the photoluminescence (PL) intensities of the QD films in the QD-2D hybrid structures can be strongly enhanced and modulated by the optical interference effect between QD and 2D interfaces, breaking the inherent standpoint that PL intensities of the QD films are always prominently quenched in these hybrid structures. The theoretical predictions have been well confirmed by experimental measurements of PL properties of CdSe/ZnS and CdSeTe/ZnS QD on different 2D materials (such as WSe2, MoS2, and h-BN). PL intensities of these QD films have been periodically modulated from almost disappearing to strong enhancement (with the enhancement of about 6 times). The optical interference effect uncovered in this work enables a powerful method to manipulate the PL property of the QD films in the different QD-2D hybrid structures. These results can boost the optical performance of the QD-based electronic and optoelectronic devices in the hybrid QD-2D structures.

Great enhancement on two-photon photoluminescence imaging contrast of Au nanoparticles via double-pulse femtosecond laser excitation with controlled phase differences.

Au nanoparticles are attractive contrast agents for noninvasive living tissue imaging with deep penetration because of their strong two-photon photoluminescence (TPPL) intensity and excellent biocompatibility. However, the inevitable phototoxicity and huge auto-fluorescence are consistently associated with laser excitation. Therefore, enhancement of TPPL intensity and suppression of backgrounds are always highly desired under the demand of reducing excitation powers. In this work, we develop a double-pulse TPPL (DP-TPPL) scheme with controlled phase differences (Δφ) between the double pulses to significantly improve the signal-to-noise ratio (SNR) of TPPL imaging. Under the modulated phase (Δφ periodically varying between 0-2π), our results show that SNR can be improved from 4.3 to 1715, with an enhancement of up to 400 folds at the integration of 50 ms. More importantly, this enhancement can be unlimitedly lifted by increasing the number of photons or integration times in principle. Further boosting has been achieved by reducing the magnitude of background noises; subsequently, SNR is improved by more than 104 times. Our schemes offer great potential for reducing phototoxicity and extracting extremely weak signals from huge backgrounds and open up a new possibility for a rapid, flexible, and reliable medical diagnosis by TPPL imaging with diminished laser powers.

Coherent Interference Fringes of Two-Photon Photoluminescence in Individual Au Nanoparticles: The Critical Role of the Intermediate State.

The interaction between light and metal nanoparticles enables investigations of microscopic phenomena on nanometer length and ultrashort timescales, benefiting from strong confinement and enhancement of the optical field. However, the ultrafast dynamics of these nanoparticles are primarily investigated by multiphoton photoluminescence on picoseconds or photoemission on femtoseconds independently. Here, we presented two-photon photoluminescence (TPPL) measurements on individual Au nanobipyramids (AuNP) to reveal their ultrafast dynamics by double-pulse excitation on a global timescale ranging from subfemtosecond to tens of picoseconds. Two orders of magnitude photoluminescence enhancement, namely, coherent interference fringes, has been demonstrated. Power-dependent measurements uncovered the transform of the nonlinearity from 1 to 2 when the interpulse delay varied from tens of femtoseconds to tens of picoseconds. We proved that the real intermediate state plays a critical role in the observed phenomena, supported by numerical simulations with a three-state model. Our results provide insight into the role of intermediate states in the ultrafast dynamics of noble metal nanoparticles. The presence of the intermediate states in AuNP and the coherent control of state populations offer interesting perspectives for imaging, sensing, nanophotonics, and in particular, for preparing macroscopic superposition states at room temperature and low-power superresolution stimulated emission depletion microscopy.

Criteria for Assessing the Interlayer Coupling of van der Waals Heterostructures Using Ultrafast Pump-Probe Photoluminescence Spectroscopy.

van der Waals (vdW) heterostructures of transition metal dichalcogenides (TMDCs) provide an excellent paradigm for next-generation electronic and optoelectronic applications. However, the reproducible fabrications of vdW heterostructure devices and the boosting of practical applications are severely hindered by their unstable performance, due to the lack of criteria to assess the interlayer coupling in heterostructures. Here we propose a physical model involving ultrafast electron transfer in the heterostructures and provide two criteria, η (the ratio of the transferred electrons to the total excited electrons) and ζ (the relative photoluminescence variation), to evaluate the interlayer coupling by considering the electron transfer in TMDC heterostructures and numerically simulating the corresponding rate equations. We have proved the effectiveness and robustness of two criteria by measuring the pump-probe photoluminescence intensity of monolayer WS2 in the WS2/WSe2 heterostructures. During thermal annealing of WS2/WSe2, ζ varies from negative to positive values and η changes between 0 and 4.5 × 10-3 as the coupling strength enhanced; both of them can well characterize the tuning of interlayer coupling. We also design a scheme to image the interlayer coupling by performing PL imaging at two time delays. Our scheme offers powerful criteria to assess the interlayer coupling in TMDC heterostructures, offering opportunities for the implementation of vdW heterostructures for broadband and high-performance electronic and optoelectronic applications.

Reversible engineering of spin-orbit splitting in monolayer MoS2via laser irradiation under controlled gas atmospheres.

Monolayer transition metal dichalcogenides, manifesting strong spin-orbit coupling combined with broken inversion symmetry, lead to coupling of spin and valley degrees of freedom. These unique features make them highly interesting for potential spintronic and valleytronic applications. However, engineering spin-orbit coupling at room temperature as demanded after device fabrication is still a great challenge for their practical applications. Here we reversibly engineer the spin-orbit coupling of monolayer MoS2 by laser irradiation under controlled gas environments, where the spin-orbit splitting has been effectively regulated within 140 meV to 200 meV. Furthermore, the photoluminescence intensity of the B exciton can be reversibly manipulated over 2 orders of magnitude. We attribute the engineering of spin-orbit splitting to the reduction of binding energy combined with band renormalization, originating from the enhanced absorption coefficient of monolayer MoS2 under inert gases and subsequently the significantly boosted carrier concentrations. Reflectance contrast spectra during the engineering stages provide unambiguous proof to support our interpretation. Our approach offers a new avenue to actively control the spin-orbit splitting in transition metal dichalcogenide materials at room temperature and paves the way for designing innovative spintronic devices.

Exploration of exciton dynamics in GaTe nanoflakes via temperature- and power-dependent time-resolved photoluminescence spectra.

GaTe nanoflakes have been receiving much research attention recently due to their applications in optoelectronic devices, such as anisotropic non-volatile memory, solar cells, and high-sensitivity photodetectors from the ultraviolet to the visible region. Further applications, however, have been impeded due to the limited understanding of their exciton dynamics. In this work we perform temperature- and power-dependent time-resolved photoluminescence (PL) spectra to comprehensively investigate the exciton dynamics of GaTe nanoflakes. Temperature-dependent PL measurements manifest that spectral profiles of GaTe nanoflakes change dramatically from cryogenic to room temperature, where the bound exciton and donor-to-acceptor pair transition normally disappear above 100 K, while the charged exciton survives to room temperature. The lifetimes of these excitons and their evolution vs temperature have been uncovered by time-resolved PL spectra. Further measurements reveal the entirely different power-dependent exciton behaviors of GaTe nanoflakes between room and cryogenic temperatures. The underlying mechanisms have been proposed to explore the sophisticated exciton dynamics within GaTe nanoflakes. Our results offer a more thorough understanding of the exciton dynamics of GaTe nanoflakes, enabling further progress in engineering GaTe-based applications, such as photodetectors, light-emitting diodes, and nanoelectronics.

Underestimated effect of the polymer encapsulation process on the photoluminescence of perovskite revealed by in situ single-particle detection.

Photostability has always been an important issue that limits the performance of organo-metal halide perovskites in optoelectronic devices. Although the photostability can be partially improved by polymer coating/encapsulation, one rising question that needs to be considered is whether the improvement of photostability is accessed at the expense of intangible loss in photoluminescence (PL) properties. By in situ analyzing the evolution of PL properties of individual perovskite crystals during the polymer encapsulation procedure, we demonstrate here that poly(methyl methacrylate), a common polymeric encapsulant, would passivate the surface defects of perovskite crystals, leading to the suppress of PL blinking. However, somewhat counterintuitive, the toluene solvent will induce the PL decline of individual perovskite crystals via accumulation of the number of quenchers that, most probably, are related to the ion migration in perovskite. The findings at the single-particle level emphasize the often-neglected role of the polymer matrix and the solvent in the optical properties of perovskite material during the polymer encapsulation process, and will guide the further design of more stable and high-performance devices based on perovskite.

Visualizing Quantum Coherence Based on Single-Molecule Coherent Modulation Microscopy.

Massive magical phenomena in nature are closely related to quantum effects at the microscopic scale. However, the lack of straightforward methods to observe the quantum coherent dynamics in integrated biological systems limits the study of essential biological mechanisms. In this work, we developed a single-molecule coherent modulation (SMCM) microscopy by combining the superior features of single-molecule microscopy with ultrafast spectroscopy. By introducing the modem technology and defining the coherent visibility, we realized visualization and real-time observation of the decoherence process of a single molecule influenced by the microenvironment for the first time. In particular, we applied this technique to observe the quantum coherent properties of the entire chlorella cells and found the correlation between the coherent visibility and metabolic activities, which may have potential applications in molecular diagnostics and precision medicine.