Tree parameter extraction in Fokienia hodginsii plantation based on airborne LiDAR data.

Accurate and efficient extraction of tree parameters from plantations lay foundation for estimating individual wood volume and stand stocking. In this study, we proposed a method of extracting high-precision tree parameters based on airborne LiDAR data. The main process included data pre-processing, ground filtering, individual tree segmentation, and parameter extraction. We collected high-density airborne point cloud data from the large-diameter timber of Fokienia hodginsii plantation in Guanzhuang State Forestry Farm, Shaxian County, Fujian Province, and pre-processed the point cloud data by denoising, resampling and normalization. The vegetation point clouds and ground point clouds were separated by the Cloth Simulation Filter (CSF). The former data were interpolated using the Delaunay triangulation mesh method to generate a digital surface model (DSM), while the latter data were interpolated using the Inverse Distance Weighted to generate a digital elevation model (DEM). After that, we obtained the canopy height model (CHM) through the difference operation between the two, and analyzed the CHM with varying resolutions by the watershed algorithm on the accuracy of individual tree segmentation and parameter extraction. We used the point cloud distance clustering algorithm to segment the normalized vegetation point cloud into individual trees, and analyzed the effects of different distance thresholds on the accuracy of indivi-dual tree segmentation and parameter extraction. The results showed that the watershed algorithm for extracting tree height of 0.3 m resolution CHM had highest comprehensive evaluation index of 91.1% for individual tree segmentation and superior accuracy with R2 of 0.967 and RMSE of 0.890 m. When the spacing threshold of the point cloud segmentation algorithm was the average crown diameter, the highest comprehensive evaluation index of 91.3% for individual tree segmentation, the extraction accuracy of the crown diameter was superior, with R2 of 0.937 and RMSE of 0.418 m. Tree height, crown diameter, tree density, and spatial distribution of trees were estimated. There were 5994 F. hodginsii, with an average tree height of 16.63 m and crown diameter of 3.98 m. Trees with height of 15-20 m were the most numerous (a total of 2661), followed by those between 10-15 m. This method of forest parameter extraction was useful for monitoring and managing plantations.

Prevalence and Risk Factors Underlying Occupational Stress and Depression Among Clinical Nurses in Secondary and Tertiary Hospitals of China During COVID-19 Setting.

Aim: This study was designed to develop an effective measurement tool for occupational stress among medical staff and to identify the underlying risk factors among clinical nurses in China under depression during and after COVID-19. Methods: In the first stage, an occupational stress scale was developed for medical staff based on qualitative and quantitative methods. The dimensions of the scale were based on childhood stress and seven other parameters of working stress. In the second stage, a provincial survey was conducted among clinical nurses in Hainan. The structure of Medical Staff Occupational Stress Scale was tested in secondary and tertiary hospitals. The socio-demographic information, occupational stress (measured using the developed scale), and current depression symptoms (assessed with the nine-item Patient Health Questionnaire) were evaluated. The risk factors for occupational stress-induced depression were tested using multivariate logistic regression. Results: The Medical Staff Occupational Stress Scale consisted of 42 items under eight dimensions with strong reliability and validity. Almost 80% of the clinical nurses reported obvious symptoms of depression. Based on multivariate logistical regression analysis, the significant risk factors for depression in nurses at secondary hospitals and tertiary hospitals were childhood stress, teaching stress, relationship with patient stress, and administration stress. Conclusion: The Medical Staff Occupational Stress Scale utilized in nursing population is based on strong psychometric features. Childhood stress contributes to occupational stress in nurses. The selection of nurses for clinical work may require evaluation of past history for childhood stress to prevent occupational depression. Teaching stress, relationship with patient stress and administration stress play significant roles in the prevention of depression among clinical nurses.

Pharmacological targeting of Axin2 suppresses cell growth and metastasis in colorectal cancer.

BACKGROUND AND PURPOSE: The scaffold molecule Axin2 is constitutively activated in colorectal cancer (CRC) and functions as a potent promoter of CRC behaviour. Pharmacological targeting of Axin2 may therefore exert a therapeutic effect in patients with CRC. Here, we discovered a potent small-molecule inhibitor of Axin2, based on the mechanism by which Axin2 is regulated post-translationally, and investigated its antitumour effects. EXPERIMENTAL APPROACH: Compound discovery and its inhibitory action on Axin2 protein were revealed by microscale thermophoresis, in vitro kinase assay, quantitative kinetic assay, immunoblotting/immunoprecipitation, RT-qPCR and cycloheximide pulse-chase assay. Compound antitumour effects and the underlying mechanisms were evaluated in multiple cell-based assays and mouse models. KEY RESULTS: We discovered that glycogen synthase kinase 3ß (GSK3ß) phosphorylates Axin2 at two consensus motifs and coupled Axin2 phosphorylation to its ubiquitination (mediated by the E3 ligase ß-Trcp2) and proteasomal degradation. The binding of Axin2 to GSK3ß in CRC cells is faint, which enables most of the Axin2 protein to maintain an unphosphorylated status and thereby permits the cells to preserve high levels of Axin2. Importantly, we identified a small-molecule compound CW85319 that enhances Axin2's interaction with GSK3ß via forming a high affinity for Axin2. Treatment of CRC cells with CW85319 enhanced Axin2 binding with GSK3ß, thereby promoting Axin2 phosphorylation, subsequent ubiquitination, and degradation. Furthermore, we demonstrated that CW85319 efficiently suppressed Axin2-driven CRC growth and metastasis, without eliciting side toxicity. CONCLUSIONS AND IMPLICATIONS: These findings suggest that pharmacological targeting of Axin2 by CW85319 may provide therapeutic benefits against certain human cancers, especially CRC.

Z16b, a natural compound from Ganoderma cochlear is a novel RyR2 stabilizer preventing catecholaminergic polymorphic ventricular tachycardia.

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited, lethal ventricular arrhythmia triggered by catecholamines. Mutations in genes that encode cardiac ryanodine receptor (RyR2) and proteins that regulate RyR2 activity cause enhanced diastolic Ca2+ release (leak) through the RyR2 channels, resulting in CPVT. Current therapies for CPVT are limited. We found that Z16b, a meroterpenoid isolated from Ganoderma cochlear, inhibited Ca2+ spark frequency (CaSF) in R2474S/ + cardiomyocytes in a dose-dependent manner, with an IC50 of 3.2 µM. Z16b also dose-dependently suppressed abnormal post-pacing Ca2+ release events. Intraperitoneal injection (i.p.) of epinephrine and caffeine stimulated sustained ventricular tachycardia in all R2474S/+ mice, while pretreatment with Z16b (0.5 mg/kg, i.p.) prevented ventricular arrhythmia in 9 of 10 mice, and Z16b administration immediately after the onset of VT abolished sVT in 9 of 12 mice. Of translational significance, Z16b significantly inhibited CaSF and abnormal Ca2+ release events in human CPVT iPS-CMs. Mechanistically, Z16b interacts with RyR2, enhancing the "zipping" state of the N-terminal and central domains of RyR2. A molecular docking simulation and point mutation and pulldown assays identified Z16b forms hydrogen bonds with Arg626, His1670, and Gln2126 in RyR2 as a triangle shape that anchors the NTD and CD interaction and thus stabilizes RyR2 in a tight "zipping" conformation. Our findings support that Z16b is a novel RyR2 stabilizer that can prevent CPVT. It may also serve as a lead compound with a new scaffold for the design of safer and more efficient drugs for treating CPVT.

The Influence of Personality and Demographic Characteristics on Aggressive Driving Behaviors in Eastern Chinese Drivers.

PURPOSE: Road safety research is important due to the large number of road traffic fatalities globally. This study investigated the influences of age, driving experience and other covariates on aggressive driving behavior. METHODS: A cross-sectional survey was conducted in Yixing City, Wuxi City, Jiangsu Province, China. Regression analysis was applied to explore the influences of age and driving experience and their interactions with other covariates on aggressive driving behavior. Two analyses methodologies were used to assess the simple effect of the interactions. Firstly, the Jamovi automatic analysis classification program was used to calculate the simple slope test. Second, the SPSS macro program was also used to calculate the simple slope test also. RESULTS: A total of 570 drivers (247 males, 282 females) participated in the survey. A negative correlation was found between age and aggressive driving behaviors, and a positive correlation was found between neuroticism and aggressive driving behaviors in the multiple regression analysis. Significant associations were also found between age, driving experience, and depression, as well as age, driving experience, and neuroticism. Simple slope tests showed that depressive symptoms could increase aggressive behaviors in the elderly and experienced drivers. When experiencing neuroticism, individuals with higher driving experience were more aggressive in driving than shorter experienced drivers. CONCLUSION: Age and neuroticism influenced aggressive driving behaviors. Veteran drivers could be aggressive drivers when experiencing depressive symptoms or neuroticism. Mobile intervention could be sent to the potentially risky drivers, which would be safe and broadly feasible to prevent aggressive driving behavior in the background of COVID-19.

Structural Optimization and Improving Antitumor Potential of Moreollic Acid from Gamboge.

Moreollic acid, a caged-tetraprenylated xanthone from Gamboge, has been indicated as a potent antitumor molecule. In the present study, a series of moreollic acid derivatives with novel structures were designed and synthesized, and their antitumor activities were determined in multifarious cell lines. The preliminary screening results showed that all synthesized compounds selectively inhibited human colon cancer cell proliferation. TH12-10, with an IC50 of 0.83, 1.10, and 0.79 µM against HCT116, DLD1, and SW620, respectively, was selected for further antitumor mechanism studies. Results revealed that TH12-10 effectively inhibited cell proliferation by blocking cell-cycle progression from G1 to S. Besides, the apparent structure-activity relationships of target compounds were discussed. To summarize, a series of moreollic acid derivatives were discovered to possess satisfactory antitumor potentials. Among them, TH12-10 displays the highest antitumor activities against human colon cancer cells, in which the IC50 values in DLD1 and SW620 are lower than that of 5-fluorouracil.

A small-molecule compound D6 overcomes EGFR-T790M-mediated resistance in non-small cell lung cancer.

Non-small cell lung cancer (NSCLC) is a deadly and highly prevalent malignancy. Targeting activated-EGFR mutations in NSCLC via EGFR tyrosine kinase inhibitor (EGFR-TKI) initially achieves a profound therapeutic response, but resistance frequently evolves, reducing treatment options. Here, we present a small-molecule compound D6 which selectively inhibits tumor cell growth and migration in NSCLC cells with EGFR-TKI-resistant T790M-EGFR-activated mutations (T790M-EGFR-AM), e.g., L858R/T790M, 19Del/T790M and L858R/T790M/C797S. D6 mimics a natural product isolated from the roots of Codonopsis pilosula and selectively competes with T790M-EGFR-AM to bind to HSP90, thus facilitating the ubiquitination dependent proteasomal degradation of T790M-EGFR-AM. By contrast, D6 has little impact on typical HSP90 chaperone activity, suggesting low systemic toxicity. Promisingly, D6 combined with erlotinib or osimertinib shows efficacy in overcoming the EGFR-TKIs-resistance in NSCLCs. Our study raises an alternative strategy to overcome T790M-mediated EGFR-TKI resistance in NSCLC via targeting the protein-protein interaction of HSP90 and T790M-EGFR by intervention with D6.

Neuroprotective Norsesquiterpenoids and Triterpenoids from Populus euphratica Resins.

Two new octanorlanostane-type triterpenes, euphraticanoids A and B (1 and 2), two new trinorsesquiterpenoids, euphraticanoids C and D (3 and 4), and eight known triterpenoids (5, 6, 8-13) along with one steroid (7) were isolated from Populus euphratica resins. The structures of these new compounds, including their absolute configurations, were characterized by spectrocsopic, chemical, and computational methods. Biological evaluation revealed that compounds 4, 7-9, 12, and 13 display neuroprotective activities in H2O2-induced HT-22 cells with 4, 8, and 9 occurring in a concentration-dependent manner and 7, 12, and 13 reaching the maximum effects at 20 µM. Meanwhile, the neuroprotective properties of all isolates were accessed using glutamate-induced SH-SY5Y cells and disclosed that compounds 3, 4, 8, and 9 could dose-dependently protect neural cell injury in a concentration range of 10-40 µM. Finally, a brief structure-activity relationship was briefly discussed.

Meroterpenoids from the Fungus Ganoderma sinensis and First Absolute Configuration Clarification of Zizhine H.

Five new meroterpenoids, zizhines P-S and U (1-4,7), together with two known meroterpenoids (5 and 6) were isolated from Ganoderma sinensis. Their structures including absolute configurations were assigned by using spectroscopic, computational, and chemical methods. Racemics zizhines P and Q were purified by HPLC on chiral phase. Biological evaluation found that 4, 5 and 6 are cytotoxic toward human cancer cells (A549, BGC-823, Kyse30) with IC50 values in the range of 63.43-80.83 µM towards A549, 59.2 ± 2.73 µM and 64.25 ± 0.37 µM towards BGC-823, 76.28 ± 1.93 µM and 85.42 ± 2.82 µM towards Kyse30.