Very high-frequency, gate-tunable CrPS4 nanomechanical resonator with single mode.

Two-dimensional (2D) antiferromagnetic semiconductor chromium thiophosphate (CrPS4) has gradually become a major candidate material for low-dimensional nanoelectromechanical devices due to its remarkable structural, photoelectric characteristics and potentially magnetic properties. Here, we report the experimental study of a new few-layer CrPS4 nanomechanical resonator demonstrating excellent vibration characteristics through the laser interferometry system, including the uniqueness of resonant mode, the ability to work at the very high frequency, and gate tuning. In addition, we demonstrate that the magnetic phase transition of CrPS4 strips can be effectively detected by temperature-regulated resonant frequencies, which proves the coupling between magnetic phase and mechanical vibration. We believe that our findings will promote the further research and applications of the resonator for 2D magnetic materials in the field of optical/mechanical signal sensing and precision measurement.

Gate-tunable bolometer based on strongly coupled graphene mechanical resonators.

Bolometers based on graphene have demonstrated outstanding performance with high sensitivity and short response time. In situ adjustment of bolometers is very important in various applications, but it is still difficult to implement in many systems. Here we propose a gate-tunable bolometer based on two strongly coupled graphene nanomechanical resonators. Both resonators are exposed to the same light field, and we can measure the properties of one bolometer by directly tracking the resonance frequency shifts, and indirectly measure the other bolometer through mechanical coupling. We find that the sensitivity and the response bandwidth of both bolometers can be independently adjusted by tuning the corresponding gate voltages. Moreover, the properties of the indirectly measured bolometer show a dependence on the coupling between the two resonators, with other parameters being fixed. Our method has the potential to optimize the design of large-scale bolometer arrays, and open new horizons in infrared/terahertz astronomy and communication systems.

Progressive increase of high-frequency EEG oscillations during meditation is associated with its trait effects on heart rate and proteomics: a study on the Tibetan Buddhist.

Meditation has been a spiritual and healing practice in the East for thousands of years. However, the neurophysiologic mechanisms underlying its traditional form remain unclear. In this study, we recruited a large sample of monks (n = 73) who practice Tibetan Buddhist meditation and compared with meditation-naive local controls (n = 30). Their electroencephalography (EEG) and electrocardiogram signals were simultaneously recorded and blood samples were collected to investigate the integrative effects of Tibetan Buddhist on brain, heart, and proteomics. We found that the EEG activities in monks shifted to a higher frequency from resting to meditation. Meditation starts with decrease of the (pre)frontal delta activity and increase of the (pre)frontal high beta and gamma activity; while at the deep meditative state, the posterior high-frequency activity was also increased, and could be specified as a biomarker for the deep meditation. The state increase of posterior high-frequency EEG activity was significantly correlated with the trait effects on heart rate and nueropilin-1 in monks, with the source of brain-heart correlation mainly locating in the attention and emotion networks. Our study revealed that the effects of Tibetan Buddhist meditation on brain, heart, and proteomics were highly correlated, demonstrating meditation as an integrative body-mind training.

Brain-Heart Interactions Underlying Traditional Tibetan Buddhist Meditation.

Despite accumulating evidence suggesting improvement in one's well-being as a result of meditation, little is known about if or how the brain and the periphery interact to produce these behavioral and mental changes. We hypothesize that meditation reflects changes in the neural representations of visceral activity, such as cardiac behavior, and investigated the integration of neural and visceral systems and the spontaneous whole brain spatiotemporal dynamics underlying traditional Tibetan Buddhist meditation. In a large cohort of long-term Tibetan Buddhist monk meditation practitioners, we found distinct transient modulations of the neural response to heartbeats in the default mode network (DMN), along with large-scale network reconfigurations in the gamma and theta bands of electroencephalography (EEG) activity induced by meditation. Additionally, temporal-frontal network connectivity in the EEG theta band was negatively correlated with the duration of meditation experience, and gamma oscillations were uniquely, directionally coupled to theta oscillations during meditation. Overall, these data suggest that the neural representation of cardiac activity in the DMN and large-scale spatiotemporal network integrations underlie the fundamental neural mechanism of meditation and further imply that meditation may utilize cortical plasticity, inducing both immediate and long-lasting changes in the intrinsic organization and activity of brain networks.

Development of Functional Phthalocyanine-Based Associate towards an Effective Fluorimetric Detection of Hg(II).

In acidic media, cationic phthalocyanine Alcian blue 8GX, has an efficient fluorescence quenching effect on anionic phthalocyanine tetrasulphoaluminium phthalocyanines (AlS4Pc), forming an almost non-fluorescent associate. Based on this discovery, a red-emitting fluorescent probe consisted of AlS4PC and Alcian blue 8GX has been developed through molecular assembly. Further studies indicated that the presence of Hg(II) ion has a significant fluorescence recovery effect of the probe. Notably, only Hg(II) can significantly restore the fluorescence of AlS4Pc-Alcian blue 8GX system which was revealed from the screening experiments of common metal ions, which confirmed that the fluorescence recovery by other metal ions is very weak or even unrestored, showing high specificity and sensitivity AlS4Pc-Alcian blue 8GX to Hg(II). Thus, a new fluorimetry for Hg(II) with high specificity and high sensitivity in a wide concentration range has been established using AlS4Pc-Alcian blue 8GX associate as a red-emitting fluorescent probe. It is more noteworthy that this study opens a new way for development and application of functional phthalocyanine based red-emitting fluorescent probes.

[Application of Cationic Aluminum Phthalocyanine, a Red-Emitting Fluorescent Probe, for Sensitive Quantitative Analysis of RNA at Nanogram Level].

Tetrasubstituted trimethyl ammonium iodide aluminum phthalocyanine (TTMAAlPc), a positively charged phthalocyanine compound, is an emerging and potentially useful red-emitting fluorescence probe. The study showed that the fluorescence of TTMAAlPc could be quenched by RNA with high efficiency in weak alkaline media, and the degree of quenching has a linear relationship with RNA in a wide concentration range. The mechanism of quenching behavior of RNA on TTMAAlPc was discussed. It was attributed by the static interaction between RNA and TTMAAlPc, and the assembly of TTMAAlPc induced by RNA. Based on this new discovery, a novel method for quantitative determination of RNA at nanogram level has been established. The factors, including the pH of medium, buffer system, reaction time, reaction temperature, the usage of TTMAAlPc as well as the interferences, which affected the determination, were investigated and discussed. Under optimum conditions, the linear range of the calibration curve was 7.71-1 705.57 ng x mL(-1). The detection limit for RNA was 1.55 ng x mL(-1). This method has been applied to the analysis of practical samples with satisfied results. The constructed method is of high sensitivity and has a wide linear range, it also showed strong ability in the tolerance of foreign substances from anions, cations, surfactants and vitamins, all of which are common interferences encountered in the determination of RNA. Besides, it is the first report that the fluorescence quantum yield of TTMAAlPc has been measured at different pH by reference method in this work. The achieved data indicated that the fluorescence quantum yield of TTMAAlPc is larger than 20% and it keeps constant in a wide range of acidity, implying that TTMAAlPc is a high-quality red-emitting fluorescence probe, it has great potential for practical applications, thus is worthy of further study. This work expands the application of phthalocyanine compound in analytical sciences.

[Sensitive Determination of Chondroitin Sulfate by Fluorescence Recovery of an Anionic Aluminum Phthalocyanine-Cationic Surfactant Ion-Association Complex Used as a Fluorescent Probe Emitting at Red Region].

Determination of chondroitin sulfate in the biomedical field has an important value. The conventional methods for the assay of chondroitin sulfate are still unsatisfactory in sensitivity, selectivity or simplicity. This work aimed at developing a novel method for sensitive and selective determination of chondroitin sulfate by fluorimetry. We found that some kinds of cationic surfactants have the ability to quench the fluorescence of tetrasulfonated aluminum phthalocyanine (AlS4Pc), a strongly fluorescent compound which emits at red region, with high efficiency. But, the fluorescence of the above-mentioned fluorescence quenching system recovered significantly when chondroitin sulfate (CS) exits. Tetradecyl dimethyl benzyl ammonium chloride(TDBAC) which was screened from all of the candidates of cationic surfactants was chosen as the quencher because it shows the most efficient quenching effect. It was found that the fluorescence of AlS4Pc was extremely quenched by TDBAC because of the formation of association complex between AlS4Pc and TDBAC. Fluorescence of the association complex recovered dramatically after the addition of chondroitin sulfate (CS) due to the ability of chondroitin sulfate to shift the association equilibrium of the association, leading to the release of AlS4Pc, thus resulting in an increase in the fluorescence of the reaction system. Based on this phenomenon, a novel method with simplicity, accuracy and sensitivity was developed for quantitative determination of CS. Factors including the reaction time, influencing factors and the effect of coexisting substances were investigated and discussed. Under optimum conditions the linear range of the calibration curve was 0.20~10.0 µg · mL(-1). The detection limit for CS was 0.070 µg · mL(-1). The method has been applied to the analysis of practical samples with satisfied results. This work expands the applications of AlS4Pc in biomedical area.

A real-world pharmacovigilance study of FDA adverse event reporting system (FAERS) events for niraparib.

Niraparib was approved for the treatment of platinum-sensitive recurrent epithelial ovarian cancer, fallopian tube and primary peritoneal cancer. The authors retrospectively investigated niraparib-related adverse events (AEs) through data mining of the US Food and Drug Administration Adverse Event Reporting System (FAERS). Four algorithms were employed to quantify the signals of niraparib associated AEs, using data from the FAERS between 2017 and 2021. MYSQL 8.0, Navicat Premium 15, Microsoft EXCEL 2019 and the GraphPad Prism 8 were used to conduct statistical analysis. There are 7,238,157 reports collected from the FAERS database, of which 11,701 reports listed niraparib as the 'primary suspected (PS)' drug. A total of 97 significant disproportionality PTs conforming to the four algorithms were simultaneously retained. Unexpected significant AEs such as neuropathy peripheral, photosensitivity reaction, gastrooesophageal reflux disease might also occur. The median onset time of niraparib-associated AEs was 18 days (interquartile range [IQR] 4-66 days), and most of the cases occurred within the first months after niraparib initiation. The study found niraparib-associated AEs and might provide important support for clinical monitoring and risk identification of niraparib.

The heart-brain axis: A proteomics study of meditation on the cardiovascular system of Tibetan Monks.

BACKGROUND: There have been mixed reports on the beneficial effects of meditation in cardiovascular disease (CVD), which is widely considered the leading cause of death worldwide. METHODS: To clarify the role of meditation in modulating the heart-brain axis, we implemented an extreme phenotype strategy, i.e., Tibetan monks (BMI > 30) who practised 19.20 ± 7.82 years of meditation on average and their strictly matched non-meditative Tibetan controls. Hypothesis-free advanced proteomics strategies (Data Independent Acquisition and Targeted Parallel Reaction Monitoring) were jointly applied to systematically investigate and target the plasma proteome underlying meditation. Total cholesterol, low-density lipoprotein cholesterol  (LDL-C), apolipoprotein B (Apo B) and lipoprotein (a) [Lp(a)] as the potential cardiovascular risk factors were evaluated. Heart rate variability (HRV) was assessed by electrocardiogram. FINDINGS: Obesity, hypertension, and reduced HRV is offset by long-term meditation. Notably, meditative monks have blood pressure and HRV comparable to their matched Tibetan controls. Meditative monks have a protective plasma proteome, related to decreased atherosclerosis, enhanced glycolysis, and oxygen release, that confers resilience to the development of CVD. In addition, clinical risk factors in plasma were significantly decreased in monks compared with controls, including total cholesterol, LDL-C, Apo B, and Lp(a). INTERPRETATION: To our knowledge, this work is the first well-controlled proteomics investigation of long-term meditation, which opens up a window for individuals characterized by a sedentary lifestyle to improve their cardiovascular health with an accessible method practised for more than two millennia. FUNDING: See the Acknowledgements section.

Automatic quantification of superficial foveal avascular zone in optical coherence tomography angiography implemented with deep learning.

An accurate segmentation and quantification of the superficial foveal avascular zone (sFAZ) is important to facilitate the diagnosis and treatment of many retinal diseases, such as diabetic retinopathy and retinal vein occlusion. We proposed a method based on deep learning for the automatic segmentation and quantification of the sFAZ in optical coherence tomography angiography (OCTA) images with robustness to brightness and contrast (B/C) variations. A dataset of 405 OCTA images from 45 participants was acquired with Zeiss Cirrus HD-OCT 5000 and the ground truth (GT) was manually segmented subsequently. A deep learning network with an encoder-decoder architecture was created to classify each pixel into an sFAZ or non-sFAZ class. Subsequently, we applied largest-connected-region extraction and hole-filling to fine-tune the automatic segmentation results. A maximum mean dice similarity coefficient (DSC) of 0.976 ± 0.011 was obtained when the automatic segmentation results were compared against the GT. The correlation coefficient between the area calculated from the automatic segmentation results and that calculated from the GT was 0.997. In all nine parameter groups with various brightness/contrast, all the DSCs of the proposed method were higher than 0.96. The proposed method achieved better performance in the sFAZ segmentation and quantification compared to two previously reported methods. In conclusion, we proposed and successfully verified an automatic sFAZ segmentation and quantification method based on deep learning with robustness to B/C variations. For clinical applications, this is an important progress in creating an automated segmentation and quantification applicable to clinical analysis.

Structure-matched Phthalocyanine Ion Pair as a Red-emitting Fluorescent Optical Probe for the Analysis of Sodium Dodecylbenzenesulfonate with High Specificity and Sensitivity.

We have found that a positively charged cationic copper phthalocyanine, Alcian blue (Alcian blue 8GX), can efficiently quench the fluorescence of an oppositely charged red fluorescent phthalocyanine compound with a matched molecular structure, tetrasulfonated aluminum phthalocyanine (AlS4Pc), because of the formation of an ion pair complex (AlS4Pc-Alcian blue 8GX) that exhibits almost no fluorescence. An investigation was carried out on the fluorescence recovery of AlS4Pc-Alcian blue 8GX caused by a series of anionic surfactants containing a sulfonic group (sodium dodecylbenzenesulfonate (SDBS), sodium lauryl sulfate (SLS), and sodium dodecyl sulfate (SDS)). The results showed that SDBS exhibited a significant response, and the highest sensitivity among the surfactants. Due to its high efficiency of fluorescence quenching and the high level of fluorescence recovery, direct observes can even be performed by the naked eye. The results revealed that the Alcian blue 8GX-AlS4Pc ion-pair complex fluorescent probe only responded to SDBS in the low-concentration range. Based on the new founding, this study proposed a novel principle and method of fluorescence enhancement to specifically measure the concentration of SDBS, thereby achieving a highly sensitive and highly specific determination of SDBS. Under the optimal conditions, the fluorescence intensity (I(f)) of the system and the concentration of SDBS in the range of 1 × 10(-7) - 1 × 10(-5) mol/dm(3) exhibited a good linear relationship. This method is highly sensitive, and the operation is simple and rapid. It had been applied for the quantitative analysis of SDBS in environmental water, while achieving satisfactory results compared with those of the standard method. This study developed a new application of the fluorescent phthalocyanine compounds used as molecular probes in analytical sciences.

Study of the AlS4Pc-Polylysine Ion Pair, a Red-Fluorescent Probe: Its High Specificity, Large Concentration Range Response to Bismuth Ion, and Application.

Tetrasulfonated aluminum phthalocyanine (AlS4Pc), a strongly red-emitting compound, shows high detection sensitivity, little effect of photobleaching, and photochemical stability, making it an excellent red-fluorescent probe. We have observed that in acid media, a low concentration of poly-L-lysine (PLL) has a strong fluorescence-quenching effect on AlS4Pc, forming the ion-pair complex as AlS4Pc-PLL with almost no fluorescence. However, in the presence of Bi3+, the fluorescence of AlS4Pc-PLL dramatically recovers and the emission is visual because of the remarkable recovery. Screening experiments with other metal ions reveal that only Bi3+ can restore the fluorescence of the AlS4Pc-PLL complex. The presence of other metal ions does not result in the recovery of fluorescence, indicating the high specificity of the response to Bi3+ of AlS4Pc-PLL. This is the key finding of the present study. It was also observed that the response to Bi3+ of AlS4Pc-PLL exhibits a linear relationship over a large concentration range (three orders of magnitude). Based on these findings, we have established a new quantitative analysis method for Bi3+ with high specificity and high sensitivity, using the ion-pair AlS4Pc-PLL complex as a red-fluorescent probe, and we discuss the reaction mechanism. The detection limit of this method is 0.0021 mg L-1 The linear relationship applies to the range of 0.007-34.9 mg L-1 with a correlation coefficient of 0.9993. The method established addresses the complex operation and time-consuming problems in traditional methods and is thus suitable for real applications. Satisfactory results have been obtained when the method was applied to the measurement of real samples. This study further expands the scope of new applications of phthalocyanine-based red-fluorescent probes in analytical sciences.

Novel Method for the Analysis of Ribonuclease Based on Fluorescence Recovery of a Cationic Aluminum Phthalocyanine-RNA Association Complex as a Red-emitting Fluorogenic Substrate.

The conventional spectrophotometric method that is often applied to determine ribonuclease (RNase) has disadvantages that include cumbersome manipulation, time-consuming processing and a lack of linear range. We had found that a low concentration of RNA could induce cationic aluminum phthalocyanine (tetra(trimethylammonio)aluminum phthalocyanine (TTMAAlPc)), which emitted strong red fluorescence to aggregate in neutral media, resulting in an almost complete quenching of fluorescence from the cationic aluminum phthalocyanine. The RNA is degraded through hydrolysis by RNase, which destroys the induced aggregation of TTMAAlPc on RNA and releases free TTMAAlPc, leading to a significant fluorescence recovery of the reaction system. Based on this new finding, a method to detect RNase by enhanced fluorescence was established using the TTMAAlPc-RNA association complex as a new fluorogenic substrate of RNase. The optimal conditions were determined, and the interfering foreign substances were investigated. Under optimal conditions, the linear range was 0.05 - 50 µg/L, and the detection limit was 0.02 µg/L. This method was applied for the analysis of ribonuclease in urine specimens from normal adults, and the results were consistent with those determined by conventional spectrophotometric methods. The developed method is easy to operate and highly sensitive, and has a wide linear range, thus solving issues with conventional methods. This study applied, for the first time, cationic phthalocyanine as a fluorescent probe in the detection of nuclease, which provides new applications of phthalocyanine as a fluorescent probe emitting at the red wavelength region.

Polymer-based micro/nanowire structures for three-dimensional photonic integrations.

By assembling polymer micro/nanowires, 3D wire structures for photonic integrations were fabricated, including a 2x2 crossed structure, a 3x3 crossed structure, and a parallelogram structure. Optical wave-guiding properties of the 3D wire structures were demonstrated with a measured insertion loss of 0.83 dB, on average, at 650 nm wavelength. Light can be transmitted vertically from one wire to another. Coupling efficiency between adjacent wires is tunable by changing the cross angle and the center-to-center distance.