The value evaluation of Nomogram prediction model based on CTA imaging features for selecting treatment methods for isolated superior mesenteric artery dissection.

OBJECTIVE: To evaluate value of Nomogram prediction model based on CTA imaging features for selecting treatment methods for isolated superior mesenteric artery dissection (ISMAD). METHODS: Symptomatic ISMAD patients were randomly divided into a training set and a validation set in a 7:3 ratio. In the training set, relevant risk factors for conservative treatment failure in ISMAD patients were analyzed, and a Nomogram prediction model for treatment outcome of ISMAD was constructed with risk factors. The predictive value of the model was evaluated. RESULTS: Low true lumen residual ratio (TLRR), long dissection length, and large arterial angle (superior mesenteric artery [SMA]/abdominal aorta [AA]) were identified as independent high-risk factors for conservative treatment failure (P < 0.05). The receiver operating characteristic curve (ROC) results showed that the area under curve (AUC) of Nomogram prediction model was 0.826 (95% CI: 0.740-0.912), indicating good discrimination. The Hosmer-Lemeshow goodness-of-fit test showed good consistency between the predicted curve and the ideal curve of the Nomogram prediction model. The decision curve analysis (DCA) analysis results showed that when probability threshold for the occurrence of conservative treatment failure predicted was 0.05-0.98, patients could obtain more net benefits. Similar results were obtained for the predictive value in the validation set. CONCLUSION: Low TLRR, long dissection length, and large arterial angle (SMA/AA) are independent high-risk factors for conservative treatment failure in ISMAD. The Nomogram model constructed with independent high-risk factors has good clinical effectiveness in predicting the failure.

Recent Advances in Anti-Inflammatory Compounds from Marine Microorganisms.

Marine microbial secondary metabolites with diversified structures have been found as promising sources of anti-inflammatory lead compounds. This review summarizes the sources, chemical structures, and pharmacological properties of anti-inflammatory natural products reported from marine microorganisms in the past three years (2021-2023). Approximately 252 anti-inflammatory compounds, including 129 new ones, were predominantly obtained from marine fungi and they are structurally divided into polyketides (51.2%), terpenoids (21.0%), alkaloids (18.7%), amides or peptides (4.8%), and steroids (4.3%). This review will shed light on the development of marine microbial secondary metabolites as potential anti-inflammatory lead compounds with promising clinical applications in human health.

A method combining LDA and neural networks for antitumor drug efficacy prediction.

Background: Personalized medicine has gained more attention for cancer precision treatment due to patient genetic heterogeneity in recent years. However, predicting the efficacy of antitumor drugs in advance remains a significant challenge to achieve this task. Objective: This study aims to predict the efficacy of antitumor drugs in individual cancer patients based on clinical data. Methods: This paper proposes to predict personalized antitumor drug efficacy based on clinical data. Specifically, we encode the clinical text of cancer patients as a probability distribution vector in hidden topics space using the Latent Dirichlet Allocation (LDA) model, named LDA representation. Then, a neural network is designed, and the LDA representation is input into the neural network to predict drug response in cancer patients treated with platinum drugs. To evaluate the effectiveness of the proposed method, we gathered and organized clinical records of lung and bowel cancer patients who underwent platinum-based treatment. The prediction performance is assessed using the following metrics: Precision, Recall, F1-score, Accuracy, and Area Under the ROC Curve (AUC). Results: The study analyzed a dataset of 958 patients with non-small cell cancer treated with antitumor drugs. The proposed method achieved a stratified 5-fold cross-validation average Precision of 0.81, Recall of 0.89, F1-score of 0.85, Accuracy of 0.77, and AUC of 0.81 for cisplatin efficacy prediction on the data, which most are better than those of previous methods. Of these, the AUC value is at least 4% higher than those of the previous. At the same time, the superior result over the previous method persisted on an independent dataset of 266 bowel cancer patients, showing the generalizability of the proposed method. These results demonstrate the potential value of precise tumor treatment in clinical practice. Conclusions: Combining LDA and neural networks can help predict the efficacy of antitumor drugs based on clinical text. Our approach outperforms previous methods in predicting drug clinical efficacy.

High-efficiency breeding of Bacillus siamensis with hyper macrolactins production using physical mutagenesis and a high-throughput culture system.

Macrolactins have attracted considerable attention due to their value and application in medicine and agriculture. However, poor yields severely hinder their broader application in these fields. This study aimed to improve macrolactins production in Bacillus siamensis using a combined atmospheric and room-temperature plasma mutagenesis and a microbial microdroplet culture system. After 25 days of treatment, a desirable strain with macrolactins production 3.0-fold higher than that of the parental strain was successfully selected. The addition of 30 mg/L ZnSO4 further increased macrolactins production to 503 ± 37.6 µg/mL, representing a 30.9 % improvement in production compared to controls. Based on transcriptome analysis, the synthesis pathways of amino acids, fengycin, and surfactin were found to be downregulated in IMD4036. Further fermentation experiments confirmed that inhibition of the comparative fengycin synthesis pathway was potentially driving the increased production of macrolactins. The strategies and possible mechanisms detailed in this study can provide insight into enhancing the production of other secondary metabolites toxic to the producer strains.

Non-immune functions of B7-H3: bridging tumor cells and the tumor vasculature.

B7-H3 (CD276), an immune checkpoint molecule, is overexpressed in various types of cancer and their tumor vasculature, demonstrating significant associations with adverse clinical outcomes. In addition to its well-known immune functions, B7-H3 exhibits dual co-stimulatory/co-inhibitory roles in normal physiology and the tumor microenvironment. The non-immune functions of B7-H3 in tumor cells and the tumor vasculature, including promoting tumor cell anti-apoptosis, proliferation, invasion, migration, drug resistance, radioresistance, as well as affecting cellular metabolism and angiogenesis, have increasingly gained attention from researchers. Particularly, the co-expression of B7-H3 in both tumor cells and tumor endothelial cells highlights the higher potential and clinical utility of therapeutic strategies targeting B7-H3. This review aims to summarize the recent advances in understanding the non-immune functions of B7-H3 in tumors and provide insights into therapeutic approaches targeting B7-H3, focusing on its co-expression in tumor cells and endothelial cells. The aim is to establish a theoretical foundation and practical reference for the development and optimization of B7-H3-targeted therapies.

Risk factors of moderate to severe post-thrombotic syndrome within 2 years in patients with subacute thrombosis: A case-control study.

OBJECTIVE: The aim of this study was to study the risk factors influencing the occurrence of moderate to severe post-thrombotic syndrome (PTS) within 2 years in patients with subacute lower extremity deep vein thrombosis (DVT). METHODS: Seventy patients who developed moderate to severe PTS within 2 years after subacute lower extremity DVT from June 2018 to June 2022 were retrospectively selected as the case group. They were matched 1:1 by sex and age (±5 years) with 70 patients who did not develop moderate to severe PTS during the same follow-up period as the control group. Multiple logistic regression, stratified analysis, and interaction analyses were used to explore the risk factors for moderate to severe PTS. RESULTS: The multiple logistic regression model showed that patients with iliofemoral vein thrombosis had a significantly increased risk of developing moderate to severe PTS within 2 years. Patients who underwent intraluminal intervention treatment during hospitalization had a significantly reduced risk. The odds ratios were 4.000 (95% confidence interval, 1.597-10.016) for the femoral-popliteal vein thrombosis and 0.262 (95% confidence interval, 0.106-0.647) for the anticoagulation treatment group. The stratified analysis showed that intraluminal intervention treatment was a protective factor against moderate to severe PTS within 2 years across different strata of hypertension, thrombus type, body mass index, duration of anticoagulation, and wearing compression stockings. Additionally, there was an interaction between thrombus type and treatment method, with intraluminal intervention treatment having a more pronounced effect on preventing moderate to severe PTS in patients with iliofemoral vein thrombosis. CONCLUSIONS: Iliofemoral vein thrombosis is a risk factor for the development of moderate to severe PTS within 2 years in patients with subacute lower extremity DVT. Intraluminal intervention treatment can reduce the risk of moderate to severe PTS, especially in patients with iliofemoral vein thrombosis.

Evolution of FLOWERING LOCUS T-like genes in angiosperms: a core Lamiales-specific diversification.

Plant life history is determined by two transitions, germination and flowering time, in which the phosphatidylethanolamine-binding proteins (PEBPs) FLOWERING LOCUS T (FT) and TERMINAL FLOWER1 (TFL1) play key regulatory roles. Compared with the highly conserved TFL1-like genes, FT-like genes vary significantly in copy numbers in gymnosperms, and monocots within the angiosperms, while sporadic duplications can be observed in eudicots. Here, via a systematic analysis of the PEBPs in angiosperms with a special focus on 12 representative species featuring high-quality genomes in the order Lamiales, we identified a successive lineage-specific but systematic expansion of FT-like genes in the families of core Lamiales. The first expansion event generated FT1-like genes mainly via a core Lamiales-specific whole-genome duplication (cL-WGD), while a likely random duplication produced the FT2-like genes in the lineages containing Scrophulariaceae and the rest of the core Lamiales. Both FT1- and FT2-like genes were further amplified tandemly in some families. These expanded FT-like genes featured highly diverged expression patterns and structural variation, indicating functional diversification. Intriguingly, some core Lamiales contained the relict MOTHER OF FT AND TFL1 like 2 (MFT2) that probably expanded in the common ancestor of angiosperms. Our data showcase the highly dynamic lineage-specific expansion of the FT-like genes, and thus provide important and fresh evolutionary insights into the gene regulatory network underpinning flowering time diversity in Lamiales and, more generally, in angiosperms.

Generation of a KCNQ1 (c.1032 + 2 T > C) mutant human embryonic stem cell line via CRISPR base editing.

The KCNQ1 gene encodes a voltage-gated potassium channel, which plays an important role in the repolarization of myocardial action potentials. Mutations in this gene often result in type 1 long QT syndrome (LQT1). Here, we generated a KCNQ1 (c.1032 + 2 T > C) mutant human embryonic stem cell line (WAe009-A-1D) based on the transient expression adenine base editing system that converts base A to G. The WAe009-A-1D cell maintains the morphology, pluripotency, and normal karyotype of the stem cells and is capable of differentiating into all three germ layers in vivo.

Research on the mitigation of redeposition defects on the fused silica surface during wet etching process.

The laser-induced damage of ultraviolet fused silica optics is a critical factor that limits the performance enhancement of high-power laser facility. Currently, wet etching technology based on hydrofluoric acid (HF) can effectively eliminate absorbing impurities and subsurface defects, thereby significantly enhancing the damage resistance of fused silica optics. However, with an increase in the operating fluence, the redeposition defects generated during wet etching gradually become the primary bottleneck that restricts its performance improvement. The composition and morphology of redeposition defects were initially identified in this study, followed by an elucidation of their formation mechanism. A mitigation strategy was then proposed, which combines a reduction in the generation of precipitation with an acceleration of the precipitation dissolution process. Additionally, we systematically investigated the influence of various process parameters such as extrinsic impurity, etching depth, and megasonic excitation on the mitigation of deposition defects. Furthermore, a novel multiple-step dynamic etching method was developed. Through comprehensive characterization techniques, it has been confirmed that this new etching process not only effectively mitigate redeposition defects under low fluence conditions but also exhibits significant inhibition effects on high fluence precursors. Consequently, it significantly enhances the laser damage resistance performance of fused silica optics.

Case report: Envafolimab combined with Endostar in the treatment of advanced non-small cell lung cancer with malignant pleural effusion.

Malignant pleural effusion (MPE) is one of the common complications of lung cancer. The quality of life and prognoses for MPE patients are significantly compromised. Controlling the production of MPE can relieve patients' symptoms, improve their quality of life, and prolong their survival. This article presents a case of advanced non-small cell lung cancer (NSCLC) with MPE and negative driver genes. The patient received envafolimab and Endostar in combination, resulting in a complete reduction of MPE and durable clinical benefits. The exploratory use of this treatment method improved the quality of life of this patient and has the potential to prolong the survival of this patient.

Genomes of Meniocus linifolius and Tetracme quadricornis reveal the ancestral karyotype and genomic features of core Brassicaceae.

Brassicaceae represents an important plant family from both a scientific and economic perspective. However, genomic features related to the early diversification of this family have not been fully characterized, especially upon the uplift of the Tibetan Plateau, which was followed by increasing aridity in the Asian interior, intensifying monsoons in Eastern Asia, and significantly fluctuating daily temperatures. Here, we reveal the genomic architecture that accompanied early Brassicaceae diversification by analyzing two high-quality chromosome-level genomes for Meniocus linifolius (Arabodae; clade D) and Tetracme quadricornis (Hesperodae; clade E), together with genomes representing all major Brassicaceae clades and the basal Aethionemeae. We reconstructed an ancestral core Brassicaceae karyotype (CBK) containing 9 pseudochromosomes with 65 conserved syntenic genomic blocks and identified 9702 conserved genes in Brassicaceae. We detected pervasive conflicting phylogenomic signals accompanied by widespread ancient hybridization events, which correlate well with the early divergence of core Brassicaceae. We identified a successive Brassicaceae-specific expansion of the class I TREHALOSE-6-PHOSPHATE SYNTHASE 1 (TPS1) gene family, which encodes enzymes with essential regulatory roles in flowering time and embryo development. The TPS1s were mainly randomly amplified, followed by expression divergence. Our results provide fresh insights into historical genomic features coupled with Brassicaceae evolution and offer a potential model for broad-scale studies of adaptive radiation under an ever-changing environment.

Molecular and genetic regulation of petal number variation.

Floral forms with an increased number of petals, also known as double-flower phenotypes, have been selected and conserved in many domesticated plants, particularly in ornamentals, because of their great economic value. The molecular and genetic mechanisms that control this trait are therefore of great interest, not only for scientists, but also for breeders. In this review, we summarize current knowledge of the gene regulatory networks of flower initiation and development and known mutations that lead to variation of petal number in many species. In addition to the well-accepted miR172/AP2-like module, for which many questions remain unanswered, we also discuss other pathways in which mutations also lead to the formation of extra petals, such as those involved in meristem maintenance, hormone signalling, epigenetic regulation, and responses to environmental signals. We discuss how the concept of 'natural mutants' and recent advances in genomics and genome editing make it possible to explore the molecular mechanisms underlying double-flower formation, and how such knowledge could contribute to the future breeding and selection of this trait in more crops.

Personalized anti-tumor drug efficacy prediction based on clinical data.

Anti-tumor drug efficacy prediction poses an unprecedented challenge to realizing personalized medicine. This paper proposes to predict personalized anti-tumor drug efficacy based on clinical data. Specifically, we encode the clinical text as numeric vectors featured with hidden topics for patients using Latent Dirichlet Allocation model. Then, to classify patients into two classes, responsive or non-responsive to a drug, drug efficacy predictors are established by machine learning based on the Latent Dirichlet Allocation topic representation. To evaluate the proposed method, we collected and collated clinical records of lung and bowel cancer patients treated with platinum. Experimental results on the data sets show the efficacy and effectiveness of the proposed method, suggesting the potential value of clinical data in cancer precision medicine. We hope that it will promote the research of drug efficacy prediction based on clinical data.

VEGFR affects miR-3200-3p-mediated regulatory T cell senescence in tumour-derived exosomes in non-small cell lung cancer.

Numerous studies have demonstrated that regulatory T (Treg) cells play an important role in the tumour microenvironment (TME). The aim of this study was to investigate whether VEGFR2 affects the expression of miR-3200-3p in exosomes secreted by tumour cells, thereby influencing Treg senescence in the TME. The results showed that VEGFR2 expression level was the highest in Calu-1 cells, and after transfection with si-VEGFR2, the exosomes secreted from Calu-1 cells were extracted and characterised with no significant difference from the exosomes of the untransfected group, but the expression of miR-3200-3p in the exosomes of the transfected si-VEGFR2 group was elevated. The Cell Counting Kit-8 (CCK-8) and flow cytometry (FCM) results suggested that exosomes highly expressing miR-3200-3p could inhibit Treg cell viability and promote apoptosis levels when treated with Treg cells. Detection of the senescence-associated proteins p16 INK4A and MMP3 by western blot (WB) revealed that exosomes highly expressing miR-3200-3p were able to elevate their protein expression levels. Tumour xenograft experiments demonstrated that exosomes with high miR-3200-3p expression promoted Treg cell senescence and inhibited subcutaneous tumour growth in nude mice. Dual-luciferase reporter assays and RNA pull-down assays showed that miR-3200-3p could be linked with DDB1. Overexpression of DDB1 reverses changes in DCAF1/GSTP1/ROS protein expression caused by exosomes with high miR-3200-3p expression. In conclusion, inhibition of VEGFR2 expression in tumour cells promotes the expression of miR-3200-3p in exosomes secreted by tumour cells. miR-3200-3p enters the TME through exosomes and acts on DDB1 in Treg cells to promote senescence of Treg cells to inhibit tumour progression.

Plasma sPD-L1 and VEGF levels are associated with the prognosis of NSCLC patients treated with combination immunotherapy.

The clinical significance of plasma soluble programmed cell death ligand 1 (sPD-L1) and vascular endothelial growth factor (VEGF) for non-small cell lung cancer (NSCLC) treated with the combination of anti-angiogenic therapy and anti-PD-L1 antibody (Ab) remain unknown. This study aimed to explore the association between plasma sPD-L1 and VEGF levels and the prognosis of NSCLC patients treated with the combination of Envafolimab and Endostar. Peripheral blood samples were collected from 24 NSCLC patients at baseline and after 6 weeks of treatment and were detected for sPD-L1 and VEGF levels. Both baseline and posttreatment sPD-L1 were significantly higher in progressive disease (PD) group than in controlled disease (CD) group (median: 77.5 pg/ml vs. 64.6 pg/ml, P  = 0.036, median: 8451 pg/ml vs. 5563 pg/ml, P  = 0.012). In multivariate analysis, lower baseline sPD-L1 levels were significantly associated with longer progression-free survival (PFS) (HR = 6.834, 95% CI: 1.350-34.592, P  = 0.020). There were significantly higher posttreatment VEGF levels in PD group compared with CD group (median: 323.7 pg/ml vs. 178.5 pg/ml, P  = 0.009). Higher posttreatment VEGF levels were significantly associated with shorter PFS in multivariate analysis (HR = 5.911, 95% CI: 1.391-25.122, P  = 0.016). Plasma sPD-L1 and VEGF levels are associated with the clinical response and prognosis of NSCLC patients treated with the combination of PD-L1 inhibitors and anti-angiogenetic therapy.

Long noncoding RNA lnc-SNAPC5-3:4 inhibits malignancy by directly upregulating miR-224-3p in non-small cell lung cancer.

The mounting body of evidence demonstrates the growing importance of long noncoding RNAs in the advancement of tumors. This study aimed to investigate the molecular mechanism of lnc-SNAPC5-3:4 in non-small cell lung cancer (NSCLC). We investigated the expression of miR-224-3p and lnc-SNAPC5-3:4 in clinical NSCLC samples and NSCLC cell lines using reverse transcription polymerase chain reaction (RT-PCR). In vitro studies, A549 cell growth was estimated using Cell Counting Kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EDU), and flow cytometry assays. In vivo studies, NSCLC tumorigenesis was determined using xenograft tumor mouse models, tumor growth was evaluated using antigen Kiel 67 (Ki67) staining, and tumor apoptosis was detected through terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. The relationship between lnc-SNAPC5-3:4 and miR-224-3p was determined by luciferase reporter gene assay. Results indicated that the expression of lnc-SNAPC5-3:4 was observed to be downregulated in NSCLC tissues and cell lines. After overexpression of lnc-SNAPC5-3:4 in cultured A549 cells, proliferation decreased and apoptosis increased. Furthermore, the expression of miR-224-3p was targeted and negatively regulated by lnc-SNAPC5-3:4. The lnc-SNAPC5-3:4 upregulation inhibited cell proliferation and promoted apoptosis, which was partially blocked by miR-224-3p overexpression in A549 cells. In addition, we constructed a subcutaneous inoculation model using BALB/c nude mice, and the results indicated that lnc-SNAPC5-3:4 overexpression restrained the growth of subcutaneous tumors, decreased Ki67 expression levels, and increased apoptosis, as indicated by TUNEL staining in nude mice. However, miR-224-3p transfection resulted in the reversal of the inhibitory effect of lnc-SNAPC5-3:4 on tumor growth. In conclusion, our study revealed that lnc-SNAPC5-3:4 inhibits tumor progression in NSCLC by targeting miR-224-3p. This study provides a potential therapeutic target for inhibiting NSCLC progression.

Hippocampal volume and resting-state functional connectivity on magnetic resonance imaging in patients with Parkinson and depression.

Background: Recent structural and functional imaging studies of depression in Parkinson disease (DPD) have failed to reveal the relevant mechanism, and relatively few studies have been conducted on limbic systems such as the hippocampus. This study thus aimed to gain new insights into the pathogenesis of DPD by detecting the changes in the hippocampal structure and the resting-state functional connectivity (FC) of patients with DPD. Methods: This study included 30 patients with DPD (DPD group), 30 patients with nondepressed Parkinson disease (NDPD; NDPD group), and 30 normal controls (NCs; NC group) with no significant age or gender differences with the DPD group. The Hamilton Depression Rating Scale (HAMD) and three-dimensional T1-weighted imaging and blood oxygen level-dependent imaging data of all patients were collected. The hippocampal volumes were measured using MATLAB software (MathWorks). The correlation between hippocampal volume and the HAMD score in the DPD group was analyzed with Pearson correlation coefficient. The bilateral hippocampi were used as the regions of interest and as the seed points for FC. FC analysis was performed between the preprocessed functional data of the whole brain and the two seed points with Data Processing Assistant for Resting-State and Statistical Parametric Mapping 8 software, respectively. The correlation between FC and HAMD scores in the patients with DPD was determined using partial correlation analysis. Results: Compared with those in the NC group and the NDPD group, the bilateral hippocampal volumes in the DPD group were significantly decreased (P<0.05). There was a negative correlation between the bilateral hippocampal volume and the HAMD score in the DPD group (P<0.05). Compared with that of the NDPD group, the FC of the right hippocampus with the right occipital lobe and left precuneus was reduced in the DPD group. In the DPD group, the FC values of the right hippocampus, right occipital lobe, and left anterior cuneiform lobe were negatively correlated with HAMD scores. Conclusions: The volume of bilateral hippocampi in patients with DPD is significantly decreased and negatively correlated with the severity of depressive disorder. The weakened FC of the right hippocampus to the right occipital lobe and the left precuneus may play an important role in the neurological basis of DPD.

The comparison of morphology and transcriptome in the inner membrane reveals the potential mechanism of the heritable carapace color of the Chinese mitten crab Eriocheir sinensis.

Carapace color plays an important role in the communication, reproduction, and self-defense of crustaceans, which is also related to their economic value. Chinese mitten crab (Eriocheir sinensis) is an important aquaculture species in China, and there are different strains with heritable carapace colors, i.e. Green, White, and Red. However, there is a lack of research on the formation mechanism of carapace color of this species. This study was conducted to compare the histology and transcriptome in the inner membrane of three carapace color strains of E. sinensis. Histological comparisons revealed that the inner membrane of green and red carapace crabs contained more melanin, appearing in clusters, and had a higher presence of yellow or orange pigments. In contrast, the inner membrane of white carapace crabs had smaller and fewer melanin particles, as well as a lower presence of yellow or orange pigments. Observation under an electron microscope showed that the inner membrane of E. sinensis contained a large number of collagen fibers and various types of cells, including fibroblasts, melanocytes, and other tissue cells, which exhibited different levels of activity. Transcriptome analysis showed that the Green, Red, and White strains of E. sinensis had approximately 80.3 K, 81.6 K and 80.3 K expressed unigenes in their inner membranes, respectively. When comparing Green and Red crabs, there were 2, 850 upregulated genes and 2, 240 downregulated genes. In the comparison between Red and White crabs, there were 2, 853 upregulated genes and 2, 583 downregulated genes. Furthermore, there were 2, 336 upregulated genes and 2, 738 downregulated genes in the inner membranes between White and Green crabs. Among these genes, some members of the solute carriers family, which are involved in carotenoid transportation, showed differential expression among the three carapace color strains. Additionally, significant differences were observed in the expression of genes related to melanin synthesis, including wingless/integrate, tyrosinase, guanine nucleotide-binding protein inhibitory subunit, cell adhesion molecule, adenylyl cyclase, and creb-binding protein. there were no differences in the gene expression levels of the crustacyanin family. In conclusion, this study identified several candidate genes associated with carapace color in the inner membrane of E. sinensis, suggesting a close relationship between the heritable carapace colors and the transport of the carotenoids as well as the synthesis of melanin.

The Characterization of Laser-Induced Particles Generated from Aluminum Alloy in High Power Laser Facility.

Aerosol particle contamination in high-power laser facilities has become a major cause of internal optical component damage resistance and service life reduction. In general, contaminating particles primarily originate from stray light; therefore, it is crucial to investigate the mechanism and dynamics of the dynamic contaminating particle generation to control the cleanliness level. In this study, corresponding research was conducted on experiments and theory. We investigated the particle generation and surface composition modification under the action of a laser. We employed various surface analytical methods to identify the possible variations in the aluminum alloy surface during laser irradiations. A theoretical model for particle ejection from aluminum alloy surfaces was established by taking the adhesion force and laser cleaning force (due to thermal expansion) into account. The results show that the threshold energies for contamination particle generation and damage are around 0.1 and 0.2 J/cm2, respectively. Subsurface impurities are the primary source of particles, and particle adhesion density is related to surface roughness. Pollution particle generation and splashing processes include temperature increases, phase changes, impact diffusion, and adhesion. The results provide a reference for the normal operation of high-energy laser systems. The results also suggest that the laser irradiation pretreatment of aluminum alloy surfaces is essential to improve the cleanliness level.

High temperature inhibits photosynthesis of chrysanthemum (Chrysanthemum morifolium Ramat.) seedlings more than relative humidity.

High relative humidity (RH) and high temperature are expected more frequently due to climate change, and can severely affect the growth of chrysanthemums. In order to analyze the interactive effects of RH and high temperature on the photosynthetic performance of chrysanthemum, a completely randomized block experiment was conducted with three factors, namely temperature (Day/night temperature, 35°C/18°C, 38°C/18°C, 41°C/18°C), RH (Whole day RH, 50%, 70%, 90%), and treatment duration (3d, 6d, 9d). The control (CK) temperature was 28°C/18°C and RH was 50%. The results showed that with the increase of temperature, the apparent quantum efficiency (AQE), maximum net photosynthetic rate (Pn-max), net photosynthetic rate (Pn), transpiration rate (Tr), water use efficiency (WUE), maximal recorded fluorescence intensity (Fm), PSII maximal photochemical efficiency (Fv/Fm), absorption flux per cross section (ABS/CSm), trapped energy flux per cross section (TRo/CSm), electron transport flux per cross section (ETo/CSm) and photosynthetic pigment content of leaves significantly decreased, the minimal recorded fluorescence intensity (Fo), fluorescence intensity at point J of the OJIP curve (Fj) and non-photochemical quenching per cross section (DIo/CSm) significantly increased, the fluorescence difference kinetics of the OJ phase of chrysanthemum leaves showed K-bands. Pn, AQE, Fm, Fv, Fv/Fm, ABS/CSm, TRo/CSm, ETo/CSm and photosynthetic pigment content were higher at 70% RH than the other two RH conditions. The dominant factor causing the decrease of Pn in leaves was stomatal limitation at 35°C,38°C, three RH conditions, 3d and 6d, but non-stomatal limitation at 41°C and 9d. There was an interaction between temperature and RH, with a significant impact on Pn. The temperature had the greatest impact on Pn, followed by RH. This study confirms that heat stress severely affects the photosynthesis of chrysanthemum leaves, and when the temperature reaches or exceeds 35°C, adjusting the RH to 70% can effectively reduce the impact of heat stress on chrysanthemum photosynthesis.