Nonadiabatic simulation study of photoisomerization of azobenzene: Detailed mechanism and load-resisting capacity

Nonadiabatic dynamical simulations were carried out to study cis-to-trans isomerization of azobenzene under laser irradiation and/or external mechanical loads. We used a semiclassical electron-radiation-ion dynamics method that is able to describe the coevolution of the structural dynamics and the underlying electronic dynamics in a real-time manner. It is found that azobenzene photoisomerization occurs predominantly by an out-of-plane rotation mechanism even under a nontrivial resisting force of several tens of piconewtons. We have repeated the simulations systematically for a broad range of parameters for laser pulses, but could not find any photoisomerization event by a previously suggested in-plane inversion mechanism. The simulations found that the photoisomerization process can be held back by an external resisting force of 90 - 200 pN depending on the frequency and intensity of the lasers. This study also found that a pure mechanical isomerization is possible from the cis state if the azobenzene molecule is stretched by an external force of 1250 -1650 pN. Remarkably, the mechanical isomerization first proceeds through a mechanically activated inversion, and then is diverted to an ultrafast downhill rotation that accomplishes the isomerization. Implications of these findings to azobenzene-based nanomechanical devices are discussed.Comment: 9 printed page

Light response of gametophyte in Adiantum flabellulatum: transcriptome analysis and identification of key genes and pathways

Light serves not only as a signaling cue perceived by plant photoreceptors but also as an essential energy source captured by chloroplasts. However, excessive light can impose stress on plants. Fern gametophytes possess the unique ability to survive independently and play a critical role in the alternation of generations. Due to their predominantly shaded distribution under canopies, light availability becomes a limiting factor for gametophyte survival, making it imperative to investigate their response to light. Previous research on fern gametophytes’ light response has been limited to the physiological level. In this study, we examined the light response of Adiantum flabellulatum gametophytes under different photosynthetic photon flux density (PPFD) levels and identified their high sensitivity to low light. We thereby determined optimal and stress-inducing light conditions. By employing transcriptome sequencing, weighted gene co-expression network analysis, and Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses, we identified 10,995 differentially expressed genes (DEGs). Notably, 3 PHYBs and 5 Type 1 CRYs (CRY1s) were significantly down-regulated at low PPFD (0.1 μmol m-2 s-1). Furthermore, we annotated 927 DEGs to pathways related to photosynthesis and 210 to the flavonoid biosynthesis pathway involved in photoprotection. Additionally, we predicted 34 transcription factor families and identified a close correlation between mTERFs and photosynthesis, as well as a strong co-expression relationship between MYBs and bHLHs and genes encoding flavonoid synthesis enzymes. This comprehensive analysis enhances our understanding of the light response of fern gametophytes and provides novel insights into the mechanisms governing their responses to light

Nomogram combining clinical and radiological characteristics for predicting the malignant probability of solitary pulmonary nodules measuring ≤ 2 cm

BackgroundAt present, how to identify the benign or malignant nature of small (≤ 2 cm) solitary pulmonary nodules (SPN) are an urgent clinical challenge. This retrospective study aimed to develop a clinical prediction model combining clinical and radiological characteristics for assessing the probability of malignancy in SPNs measuring ≤ 2 cm.MethodIn this study, we included patients with SPNs measuring ≤ 2 cm who underwent pulmonary resection with definite pathology at Qilu Hospital of Shandong University from January 2020 to December 2021. Clinical features, preoperative biomarker results, and computed tomography characteristics were collected. The enrolled patients were randomized at a ratio of 7:3 into a training cohort of 775 and a validation cohort of 331. The training cohort was used to construct the predictive model, while the validation cohort was used to test the model independently. Univariate and multivariate logistic regression analyses were performed to identify independent risk factors. The prediction model and nomogram were established based on the independent risk factors. The receiver operating characteristic (ROC) curve was used to evaluate the identification ability of the model. The calibration power was evaluated using the Hosmer–Lemeshow test and calibration curve. The clinical utility of the nomogram was also assessed by decision curve analysis (DCA).ResultA total of 1,106 patients were included in this study. Among them, the malignancy rate of SPNs was 85.08% (941/1,106). We finally identified the following six independent risk factors by logistic regression: age, carcinoembryonic antigen, nodule shape, calcification, maximum diameter, and consolidation-to-tumor ratio. The area under the ROC curve (AUC) for the training cohort was 0.764 (95% confidence interval [CI]: 0.714–0.814), and the AUC for the validation cohort was 0.729 (95% CI: 0.647–0.811), indicating that the prediction accuracy of nomogram was relatively good. The calibration curve of the predictive model also demonstrated a good calibration in both cohorts. DCA proved that the clinical prediction model was useful in clinical practice.ConclusionWe developed and validated a predictive model and nomogram for estimating the probability of malignancy in SPNs measuring ≤ 2 cm. With the application of predictive models, thoracic surgeons can make more rational clinical decisions while avoiding overtreatment and wasting medical resources

Sciences for The 2.5-meter Wide Field Survey Telescope (WFST)

The Wide Field Survey Telescope (WFST) is a dedicated photometric survey facility under construction jointly by the University of Science and Technology of China and Purple Mountain Observatory. It is equipped with a primary mirror of 2.5m in diameter, an active optical system, and a mosaic CCD camera of 0.73 Gpix on the main focus plane to achieve high-quality imaging over a field of view of 6.5 square degrees. The installation of WFST in the Lenghu observing site is planned to happen in the summer of 2023, and the operation is scheduled to commence within three months afterward. WFST will scan the northern sky in four optical bands (u, g, r, and i) at cadences from hourly/daily to semi-weekly in the deep high-cadence survey (DHS) and the wide field survey (WFS) programs, respectively. WFS reaches a depth of 22.27, 23.32, 22.84, and 22.31 in AB magnitudes in a nominal 30-second exposure in the four bands during a photometric night, respectively, enabling us to search tremendous amount of transients in the low-z universe and systematically investigate the variability of Galactic and extragalactic objects. Intranight 90s exposures as deep as 23 and 24 mag in u and g bands via DHS provide a unique opportunity to facilitate explorations of energetic transients in demand for high sensitivity, including the electromagnetic counterparts of gravitational-wave events detected by the second/third-generation GW detectors, supernovae within a few hours of their explosions, tidal disruption events and luminous fast optical transients even beyond a redshift of 1. Meanwhile, the final 6-year co-added images, anticipated to reach g about 25.5 mag in WFS or even deeper by 1.5 mag in DHS, will be of significant value to general Galactic and extragalactic sciences. The highly uniform legacy surveys of WFST will also serve as an indispensable complement to those of LSST which monitors the southern sky.Comment: 46 pages, submitted to SCMP

Selective photocatalytic decomposition of formic acid over AuPd nanoparticle-decorated TiO2 nanofibers toward high-yield hydrogen production

We present high-yield hydrogen production through selective photocatalytic decomposition of formic acid by using electrospun TiO2 nanofibers decorated with AuPd bimetallic alloy nanoparticles under simulated sunlight irradiation. By using only 5 mg of the AuPd/TiO2 nanofibers containing the 0.75% Au and 0.25% Pd, we could achieve an optimal H2 generation rate of 88.5 μmol h−1 with an apparent quantum yield at 365 nm as 15.6%, which is higher than that of the Pd/TiO2 and Au/TiO2 nanofibers by a factor of 1.6 and 4.5, respectively. The enhanced photocatalytic decomposition of formic acid for H2 generation could be attributed to the stronger electron-sink effect of AuPd alloy nanoparticles, the high selectivity of Pd for the dehydrogenation of formic acid, and the surface plasmon resonance effect of Au. More importantly, we demonstrate that the photocatalytic processes enable re-activation of the AuPd nanoparticles that were poisoned by CO during thermal decomposition of formic acid. As such, the presented AuPd/TiO2 nanofibers are promising materials for re-generation of H2 under mild conditions from liquid storage carrier of hydrogen.Accepted versio

Hospitalization Services Utilization Between Permanent and Migrant Females in Underdeveloped Rural Regions and Contributing Factors—A Five-Time Data Collection and Analysis

The proportion of migrating females has increased, and more often, old females are left in rural regions. Resources are needed to provide suitable hospitalization service to females in underdeveloped rural regions. Using multi-stage hierarchical cluster random sampling method, nine towns from three counties were enrolled in five-time points between 2006 and 2014 in this study. The research subjects of this study were females age 15 and up. Data regarding the utilization of inpatient services were collected and analyzed. Complex sampling logistic regression was conducted to analyze influencing factors. This study reveals that for both permanent females and migrant females, the older their age, the higher their hospitalization rate. The utilization of hospitalization service for permanent females was associated with the occurrence of chronic diseases (adjusted Odds Ratio (aOR) = 5.402). In addition, permanent females suffering from chronic diseases were more likely to avoid hospitalization despite their doctor’s advice (aOR = 34.657) or leave the hospital early against medical advice (AMA) (aOR = 10.009). Interventions to combat chronic diseases and adjust compensation schemes for permanent females need to be provided

Epidermal growth factor receptor and EGFRvIII in glioblastoma: signaling pathways and targeted therapies.

Amplification of epidermal growth factor receptor (EGFR) and its active mutant EGFRvIII occurs frequently in glioblastoma (GBM). While EGFR and EGFRvIII play critical roles in pathogenesis, targeted therapy with EGFR-tyrosine kinase inhibitors (TKIs) or antibodies has only shown limited efficacy in patients. Here we discuss signaling pathways mediated by EGFR/EGFRvIII, current therapeutics, and novel strategies to target EGFR/EGFRvIII-amplified GBM

Ultraviolet Irradiation Effects on luminescent Centres in Bismuth-Doped and Bismuth-Erbium Co-Doped Optical Fibers via Atomic Layer Deposition

The effects of ultraviolet irradiation on luminescent centres in bismuth-doped (BDF) and bismuth/erbium co-doped (BEDF) optical fibers were examined in this study. The fibers were fabricated by modified chemical vapor deposition combining with atomic layer deposition method. The fibers were exposed to irradiation from a 193 nm pulsed wave argon fluoride laser, and an 830 nm wavelength laser diode pump source was employed for excitation. The experimental results showed that, for the BDF, the transmission loss was slightly reduced and the luminescence intensity was increased at the bismuth-related active aluminum centre (BAC-Al). Then, for the BEDF, the transmission loss was increased a little and the luminescence intensity was also increased at the BAC-Al centre. However, the luminescence intensity was decreased at approximately 1420 nm of the bismuth-related active silica centre (BAC-Si) for all fiber samples. One possible formation mechanism for luminescence intensity changes was probably associated with the valence state transfer of bismuth ions. The other possible mechanism was that the ArF-driven two-photon process caused luminescence changes in BAC-Al and BAC-Si. It was very important to reveal nature of luminescence properties of Bi-doped and Bi/Er co-doped optical fiber

Enhanced visible-light-driven photocatalytic hydrogen generation over g-C3N4 through loading the noble metal-free NiS2 cocatalyst

Nickel sulfide nanoparticles were successfully grown as a cocatalyst on the surface of polymeric g-C3N4 photocatalysts through a hydrothermal method. The NiS2 composition is confirmed by various spectroscopic techniques and electron microscopy. It was found that the presence of NiS2 nanoparticles on the g-C3N4 surface could greatly enhance the photocatalytic activity of g-C3N4 for hydrogen generation under visible-light irradiation. Significantly, the NiS2-loaded g-C3N4 was capable of showing an even higher photocatalytic H2 generation rate than that of Pt-loaded g-C3N4. Such enhanced photocatalytic activities by NiS2-loading could be attributed to the effective charge transfer between g-C3N4 and the attached NiS2 nanoparticles which might also serve as active sites for proton reduction into H2. Our studies demonstrate a promising strategy to develop economic noble-metal-free composites as photocatalysts for efficient solar-to-hydrogen conversion.Accepted versio