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Stimuli‐responsive photonic crystals (PCs) have been extensively studied due to their potential in fabrication of anti‐counterfeiting devices and information storage. In this work, using Ca2+ ionic crosslinker, a cholesteric liquid crystalline network (CLCN) based PC able to simultaneously present visible and fluorescence pattern by moisture treatment is designed and prepared. The circularly polarized light from helical structure of CLCN makes the reflected pattern distinguishable under different circular polarizer, implying the unique advantage of this novel coating as anti‐counterfeiting devices. More importantly, due to the thermochromic property of the liquid crystal monomers, permanent pattern is achievable by chemically crosslinking specific region at different temperature. By integrating chemically crosslinking and physically ionic crosslinking, a permanent pattern and a dynamic humidity responsive pattern can be incorporated in a single device, indicating the great potential of this novel photonic coating in information storage. [ABSTRACT FROM AUTHOR]

Imitating the structures and behaviors of natural creatures is of great significance to scientists to explore novel materials for practical applications. However, the design and fabrication of biomimetic devices with complex and outstanding performances is still on the way. A bilayer film composed of liquid crystalline networks (LCN) film and hydrochromic aggregation‐induced‐emission molecule‐doped hydrophilic layer is prepared. Under different relative humidity, the composite film can deform and change fluorescence color simultaneously. The influence of the content of the hydrophilic matrix on the fluorescent property and humidity‐responsive behaviors of the bilayer film is investigated. Thanks to the mechanical anisotropy provided by uniform‐aligned LCN film, different modes of deformation of the bilayer film are achievable, like bending, curling, and twisting. More importantly, due to the independence of the LCN film and the non‐mesogenic molecules brought by this bimorph strategy, complex alignment of the LCN film and modification by immiscible molecules are realized in a single LCN actuator. Based on the functional composite film, artificial flowers showing synergistic blooming and shape‐changing is prepared. By regulating the molecular alignment of the LC mesogens of the LCN film, the artificial flowers can imitate various blooming behaviors of natural flowers like confederate jasmine and jade lotus. [ABSTRACT FROM AUTHOR]

Understanding the biomolecular interactions in a specific organelle has been a long‐standing challenge because it requires super‐resolution imaging to resolve the spatial locations and dynamic interactions of multiple biomacromolecules. Two key difficulties are the scarcity of suitable probes for super‐resolution nanoscopy and the complications that arise from the use of multiple probes. Herein, we report a quinolinium derivative probe that is selectively enriched in mitochondria and switches on in three different fluorescence modes in response to hydrogen peroxide (H2O2), proteins, and nucleic acids, enabling the visualization of mitochondrial nucleoprotein dynamics. STED nanoscopy reveals that the proteins localize at mitochondrial cristae and largely fuse with nucleic acids to form nucleoproteins, whereas increasing H2O2 level leads to disassociation of nucleic acid–protein complexes. [ABSTRACT FROM AUTHOR]

Design and fabrication of photomechanical soft actuators has attracted intense scientific interest because of their potential in the manufacture of untethered intelligent soft robots and advanced functional devices. Trifunctional and monofunctional polymerizable molecular motors are judiciously designed and synthesized. Novel light‐driven liquid crystalline networks (LCN) are prepared by crosslinking overcrowded‐alkene‐based molecular motors with different degrees of freedom into the anisotropic LCN. The photoisomerization and thermal helix inversion of light‐driven molecular motors are reversible when only the upper part of the molecular motor is linked to the network, endowing the LCN film with remarkable photoactive performance. However, photochemical geometric change of the light‐driven molecular motor does not work after crosslinking both the upper and lower part of the motor by polymer chains. Interestingly, it is found that the fastened motor can transfer the light energy into localized heat instead of performing photoisomerization. The light‐driven molecular‐motor‐based LCN soft actuators are demonstrated to function as a grasping hand, where the continuous motions of grasping, moving, lifting, and releasing an object are successfully achieved. This work may provide inspiration to the preparation of next‐generation photoactive advanced functional materials toward their wide applications in the areas of photonics, optoelectronics, soft robotics, and beyond. [ABSTRACT FROM AUTHOR]

The development of powerful and general methods to acquire ubiquitin (Ub) chains has prompted the deciphering of Ub‐mediated processes. Herein, the cysteine‐aminoethylation assisted chemical ubiquitination (CAACU) strategy is extended and improved to enable the efficient semi‐synthesis of atypical Ub chain analogues and Ub‐based probes. Combining the Cys aminoethylation and the auxiliary‐mediated protein ligation, several linkage‐ and length‐defined atypical Ub chains including di‐Ubs, K27C‐linked tri‐Ub, K11/K48C‐branched tri‐Ub, and even the SUMOlated Ub are successfully prepared from recombinantly expressed starting materials at about a 9–20 mg L−1 expression level. In addition, the utility of this strategy is demonstrated with the synthesis of a novel non‐hydrolyzable di‐Ub PA probe, which may provide a new useful tool for the mechanistic studies of deubiquitinase (DUB) recognition. [ABSTRACT FROM AUTHOR]

The dynamics of DNA and RNA structures in live cells are important for understanding cell behaviors, such as transcription activity, protein expression, cell apoptosis, and hereditary disease, but are challenging to monitor in live organisms in real time. The difficulty is largely due to the lack of photostable imaging probes that can distinguish between DNA and RNA, and more importantly, are capable of crossing multiple membrane barriers ranging from the cell/organelle to the tissue/organ level. We report the discovery of a cationic carbon quantum dot (cQD) probe that emits spectrally distinguishable fluorescence upon binding with double‐stranded DNA and single‐stranded RNA in live cells, thereby enabling real‐time monitoring of DNA and RNA localization and motion. A surprising finding is that the probe can penetrate through various types of biological barriers in vitro and in vivo. Combined with standard and super‐resolution microscopy, photostable cQDs allow time‐lapse imaging of chromatin and nucleoli during cell division and Caenorhabditis elegans (C. elegans) growth. [ABSTRACT FROM AUTHOR]

Enzyme activity in live cells is dynamically regulated by small‐molecule transmitters for maintaining normal physiological functions. A few probes have been devised to measure intracellular enzyme activities by fluorescent imaging, but the study of the regulation of enzyme activity via gasotransmitters in situ remains a long‐standing challenge. Herein, we report a three‐channel imaging correlation by a single dual‐reactive fluorescent probe to measure the dependence of phosphatase activity on the H2S level in cells. The two sites of the probe reactive to H2S and phosphatase individually produce blue and green fluorescent responses, respectively, and resonance energy transfer can be triggered by their coexistence. Fluorescent analysis based on the three‐channel imaging correlation shows that cells have an ideal level of H2S to promote phosphatase activity up to its maximum. Significantly, a slight deviation from this H2S level leads to a sharp decrease of phosphatase activity. The discovery further strengthens our understanding of the importance of H2S in cellular signaling and in various human diseases. Two for one: A dual‐reactive molecular probe has been devised to simultaneously measure intracellular H2S levels and phosphatase activity. Fluorescent analysis by three‐channel imaging correlation reveals that a slight deviation from the normal H2S level leads to a sharp decrease of phosphatase activity. [ABSTRACT FROM AUTHOR]

Abstract: The nucleus accumbens (NAc), an important target of deep brain stimulation for some neuropsychiatric disorders, is thought to be involved in epileptogenesis, especially the shell portion. However, little is known about the exact parcellation within the NAc, and its structural abnormalities or connections alterations of each NAc subdivision in temporal lobe epilepsy (TLE) patients. Here, we used diffusion probabilistic tractography to subdivide the NAc into core and shell portions in individual TLE patients to guide stereotactic localization of NAc shell. The structural and connection abnormalities in each NAc subdivision in the groups were then estimated. We successfully segmented the NAc in 24 of 25 controls, 14 of 16 left TLE patients, and 14 of 18 right TLE patients. Both left and right TLE patients exhibited significantly decreased fractional anisotropy (FA) and increased radial diffusivity (RD) in the shell, while there was no significant alteration in the core. Moreover, relatively distinct structural connectivity of each NAc subdivision was demonstrated. More extensive connection abnormalities were detected in the NAc shell in TLE patients. Our results indicate that neuronal degeneration and damage caused by seizure mainly exists in NAc shell and provide anatomical evidence to support the role of NAc shell in epileptogenesis. Remarkably, those NAc shell tracts with increased connectivities in TLE patients were found decreased in FA, which indicates disruption of fiber integrity. This finding suggests the regeneration of aberrant connections, a compensatory and repair process ascribed to recurrent seizures that constitutes part of the characteristic changes in the epileptic network. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the value of multiparametric magnetic resonance imaging (MRI) diffusion-weighted imaging (DWI) for monitoring the ultra-early (within 24 hours) treatment effect of sorafenib in human hepatocellular carcinoma (HCC) xenografts.Materials and Methods: With institutional Animal Care and Use Committee approval, 16 BALB/c nude mice bearing subcutaneous HCC xenografts underwent serial Gaussian and non-Gaussian DWI at baseline and 1, 3, 6, 12, and 24 hours posttreatment using a 1.5T whole-body MRI system. Gaussian-DWI-derived apparent diffusion coefficient (ADC), D, D*, and f, and non-Gaussian-DWI-derived MD, MK, DDC, and α were calculated and compared between the control (n = 6) and sorafenib-treated groups (n = 10) with respect to each timepoint using Mann-Whitney or Wilcoxon signed-rank test. Results were validated by pathology.Results: Compared to baseline, ADC and D at 1 hour posttreatment (P = 0.005 and P = 0.013, respectively) and MD and DDC at 3 hours posttreatment (P = 0.009 and P = 0.005, respectively) significantly decreased and remained lower through 12 hours of follow-up (P = 0.005-0.022), followed by recovery to baseline levels at 24 hours posttreatment (P = 0.139-0.646). MK significantly increased at 1 hour posttreatment (P = 0.013) and remained higher through 24 hours of follow-up (P = 0.009-0.028). No significant differences were found in D*, f, and α at different timepoints (P = 0.188-0.714). Light microscopy did not reveal abnormal findings until 3 hours posttreatment, when central patchy necrosis was observed; more prominent diffuse necrosis was observed at 24 hours. Electron microscopy revealed swollen mitochondria at 1 hour posttreatment and accumulation of intracellular autophagosomes from 3 to 24 hours posttreatment.Conclusion: Multiparametric DWI might evaluate therapeutic effects of sorafenib in HCC, where metrics of ADC, D, and MK could potentially serve as imaging biomarkers for monitoring therapeutic effects as early as 1 hour after treatment. Level of Evidence 1 Technical Efficacy: Stage 4 J. MAGN. RESON. IMAGING 2017;46:248-256. [ABSTRACT FROM AUTHOR]

Parkinson's disease (PD) is a heterogeneous neurodegenerative disorder with variable clinicopathologic phenotypes and underlying neuropathologic mechanisms. Each clinical phenotype has a unique set of motor symptoms. Tremor is the most frequent initial motor symptom of PD and is the most difficult symptom to treat. The dentate nucleus (DN) is a deep iron-rich nucleus in the cerebellum and may be involved in PD tremor. In this study, we test the hypothesis that DN iron may be elevated in tremor-dominant PD patients using quantitative susceptibility mapping. Forty-three patients with PD [19 tremor dominant (TD)/24 akinetic rigidity (AR) dominant] and 48 healthy gender- and age-matched controls were recruited. Multi-echo gradient echo data were collected for each subject on a 3.0-T MR system. Inter-group susceptibility differences in the bilateral DN were investigated and correlations of clinical features with susceptibility were also examined. In contrast with the AR-dominant group, the TD group was found to have increased susceptibility in the bilateral DN when compared with healthy controls. In addition, susceptibility was positively correlated with tremor score in drug-naive PD patients. These findings indicate that iron load within the DN may make an important contribution to motor phenotypes in PD. Moreover, our results suggest that TD and AR-dominant phenotypes of PD can be differentiated on the basis of the susceptibility of the DN, at least at the group level. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Cesium lead halide quantum dots (QDs) have tunable photoluminescence that is capable of covering the entire visible spectrum and have high quantum yields, which make them a new fluorescent materials for various applications. Here, the synthesis of CsPbX3 (X = Cl, Br, I, or mixed Cl/Br and Br/I) QDs by direct ion reactions in ether solvents is reported, and for the first time the synergetic effects of solvent polarity and reaction temperature on the nucleation and growth of QDs are demonstrated. The use of solvent with a low polarity enables controlled growth of QDs, which facilitates the synthesis of high-quality CsPbX3 QDs with broadly tunable luminescence, narrow emission width, and high quantum yield. A QD white LED (WLED) is demonstrated by coating the highly fluorescent green-emissive CsPbBr3 QDs together with red phosphors on a blue InGaN chip, which presents excellent warm white light emission with a high rendering index of 93.2 and color temperature of 5447 K, suggesting the potential applications of highly fluorescent cesium lead halide perovskite QDs as an alternative color converter in the fabrication of WLEDs. [ABSTRACT FROM AUTHOR]

In Parkinson's disease (PD), iron elevation in specific brain regions as well as selective loss of dopaminergic neurons is a major pathologic feature. A reliable quantitative measure of iron deposition is a potential biomarker for PD and may contribute to the investigation of iron-mediated PD. The primary purpose of this study is to assess iron variations in multiple deep grey matter nuclei in early PD with a novel MRI technique, quantitative susceptibility mapping (QSM). The inter-group differences of susceptibility and R2* value in deep grey matter nuclei, namely head of caudate nucleus (CN), putamen (PUT), global pallidus (GP), substantia nigra (SN), and red nucleus (RN), and the correlations between regional iron deposition and the clinical features were explored in forty-four early PD patients and 35 gender and age-matched healthy controls. Susceptibility values were found to be elevated within bilateral SN and RN contralateral to the most affected limb in early PD compared with healthy controls (HCs). The finding of increased susceptibility in bilateral SN is consistent with work on a subgroup of patients at the earliest clinical detectable state (Hoehn and Yahr [1967]: Neurology 17:427-442; Stage I). However, increased R2* values were only seen within SN contralateral to the most affected limb in the PD group when compared with controls. Furthermore, bilateral SN magnetic susceptibility positively correlated with disease duration and UPDRS-III scores in early PD. This finding supports the potential value of QSM as a non-invasive quantitative biomarker of early PD. Hum Brain Mapp 36:4407-4420, 2015. © 2015 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

The white backlight in displays is generated by optimizing the proportions of individual emitters with different wavelengths by variations in materials composition, phase, and structure. Color pixels usually result from the separation of white light or the excitation with multiwavelength or multipulse sources. However, it is a challenge to develop a material that comprises a single structure and emits over the full visible spectrum, but where the emission wavelengths can be controlled by a simple excitation source. Herein, we report an upconversion nanostructure that incorporates several lanthanide ions in the same core@shell@shell structure. The combination of multiple narrow spectral bands results in the emission of white light. The emission colors can be tuned by changing the excitation power density, which manipulates the photon transfer pathways. Applications such as flat-panel displays and imaging have been demonstrated. [ABSTRACT FROM AUTHOR]

Our aim was to prospectively evaluate the feasibility of diffusional kurtosis imaging (DKI) in normal human kidney and to report preliminary DKI measurements. Institutional review board approval and informed consent were obtained. Forty-two healthy volunteers underwent diffusion-weighted imaging (DWI) scans with a 3-T MR scanner. b values of 0, 500 and 1000 s/mm2 were adopted. Maps of fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity ( D⊥), axial diffusivity ( D||), mean kurtosis (MK), radial kurtosis ( K⊥) and axial kurtosis ( K||) were produced. Three representative axial slices in the upper pole, mid-zone and lower pole were selected in the left and right kidney. On each selected slice, three regions of interest were drawn on the renal cortex and another three on the medulla. Statistical comparison was performed with t-test and analysis of variance. Thirty-seven volunteers successfully completed the scans. No statistically significant differences were observed between the left and right kidney for all metrics ( p values in the cortex: FA, 0.114; MD, 0.531; D⊥, 0.576; D||, 0.691; MK, 0.934; K⊥, 0.722; K||, 0.891; p values in the medulla: FA, 0.348; MD, 0.732; D⊥, 0.470; D||, 0.289; MK, 0.959; K⊥, 0.780; K||, 0.287). Kurtosis metrics (MK, K||, K⊥) obtained in the renal medulla were significantly ( p <0.001) higher than those in the cortex (0.552 ± 0.04, 0.637 ± 0.07 and 0.530 ± 0.08 in the medulla and 0.373 ± 0.04, 0.492 ± 0.06 and 0.295 ± 0.06 in the cortex, respectively). For the diffusivity measures, FA of the medulla (0.356 ± 0.03) was higher than that of the cortex (0.179 ± 0.03), whereas MD, D⊥ and D|| (mm2/ms) were lower in the medulla than in the cortex (3.88 ± 0.09, 3.50 ± 0.23 and 4.65 ± 0.29 in the cortex and 2.88 ± 0.11, 2.32 ± 0.20 and 3.47 ± 0.31 in the medulla, respectively). Our results indicate that DKI is feasible in the human kidney. We have reported the preliminary DKI measurements of normal human kidney that demonstrate well the non-Gaussian behavior of water diffusion, especially in the renal medulla. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Graphene oxide has widely been employed in various fields, but its structure and composition has still not been fully understood. Here we report that freshly prepared graphene oxide exhibits a large number of π-conjugated carbon radicals at its π-network plane, which result from the addition reaction of hydroxyl radicals from H2O2 onto the conjugated double bonds of graphene oxide. The π-conjugated carbon radicals can directly initiate the long-lasting visible chemiluminescence of luminol, which is even stronger than that obtained when horseradish peroxidase and H2O2 are used. Previously, graphene oxide was mainly reported to be a quencher of chemiluminescence instead. Remarkably, the reacted radicals can be regenerated, thereby enabling the repetitive initiation of chemiluminescence by re-treatment of graphene oxide. The results reported here provide a new understanding of the structure, properties, and applications of graphene oxide. [ABSTRACT FROM AUTHOR]

In this preliminary study, we aimed to investigate the abnormalities of water diffusion in children with temporal lobe epilepsy (TLE). Eight children with unilateral TLE (according to electroencephalography, EEG) and eight age- and sex-matched controls were recruited. Diffusion tensor imaging (DTI)/diffusional kurtosis imaging (DKI) acquisitions were performed. Radial diffusivity ( λ⊥), axial diffusivity ( λ∥), mean diffusivity (MD) and fractional anisotropy (FA) maps were calculated for both DTI and DKI, and radial kurtosis ( K⊥), axial kurtosis ( K∥) and mean kurtosis (MK) maps were calculated for DKI only. Mann-Whitney test showed that, for white matter in the temporal lobe, DKI-derived λ∥, MD and K∥ were significantly different in bilateral temporal lobes and EEG-abnormal and EEG-normal sides of the temporal lobe between patients and controls, whereas DTI showed no abnormalities. For gray matter, DKI detected significantly higher MD and MK in the same three comparisons, whereas DTI detected abnormalities only in the comparison between bilateral temporal lobes and between EEG-normal sides in cases and left-right matched sides in controls. No significant difference was observed between EEG-abnormal and EEG-normal sides in cases. These preliminary results indicate that DKI is more sensitive than DTI for the detection of diffusion abnormalities in the temporal lobes of children with TLE, even when EEG signals are normal. These findings pave the way for the application of DKI for in-depth studies on TLE in children. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Since the first discovery of luminescent graphene oxide (GO), exponentially increasing investigations on the tunable structures and surfaces for modulating its optical properties have struggled to expand applications in imaging, sensing, biomedical diagnostics, and so on. Here, the latest works on reconstructing or modifying the structures and surfaces of GO to achieve diverse luminescence are systematically reviewed, including fluorescence, electroluminescence, and chemiluminescence. Moreover, the fundamental difficulties of the investigations and applications of luminescent GO nanomaterials are clarified to inspire more constructive thoughts for expanding their application boundaries. [ABSTRACT FROM AUTHOR]