Multiple sequence alignment-based RNA language model and its application to structural inference.

Compared with proteins, DNA and RNA are more difficult languages to interpret because four-letter coded DNA/RNA sequences have less information content than 20-letter coded protein sequences. While BERT (Bidirectional Encoder Representations from Transformers)-like language models have been developed for RNA, they are ineffective at capturing the evolutionary information from homologous sequences because unlike proteins, RNA sequences are less conserved. Here, we have developed an unsupervised multiple sequence alignment-based RNA language model (RNA-MSM) by utilizing homologous sequences from an automatic pipeline, RNAcmap, as it can provide significantly more homologous sequences than manually annotated Rfam. We demonstrate that the resulting unsupervised, two-dimensional attention maps and one-dimensional embeddings from RNA-MSM contain structural information. In fact, they can be directly mapped with high accuracy to 2D base pairing probabilities and 1D solvent accessibilities, respectively. Further fine-tuning led to significantly improved performance on these two downstream tasks compared with existing state-of-the-art techniques including SPOT-RNA2 and RNAsnap2. By comparison, RNA-FM, a BERT-based RNA language model, performs worse than one-hot encoding with its embedding in base pair and solvent-accessible surface area prediction. We anticipate that the pre-trained RNA-MSM model can be fine-tuned on many other tasks related to RNA structure and function.

Comparison of prediction models for cardiovascular and mortality risk in people with type 2 diabetes: An external validation in 23 685 adults included in the UK Biobank.

AIMS: To validate cardiovascular risk prediction models for individuals with diabetes using the UK Biobank in order to assess their applicability. METHODS: We externally validated 19 cardiovascular risk scores from seven risk prediction models (Chang et al., Framingham, University of Hong Kong-Singapore [HKU-SG], Li et al, RECODe [risk equations for complications of type 2 diabetes], SCORE [Systematic Coronary Risk Evaluation] and the UK Prospective Diabetes Study Outcomes Model 2 [UKPDS OM2]), identified from systematic reviews, using UK Biobank data from 2006 to 2021 (n = 23 685; participant age 40-71 years, 63.5% male). We evaluated performance by assessing the discrimination and calibration of the models for the endpoints of mortality, cardiovascular mortality, congestive heart failure, myocardial infarction, stroke, and ischaemic heart disease. RESULTS: Over a total of 269 430 person-years of follow-up (median 11.89 years), the models showed low-to-moderate discrimination performance on external validation (concordance indices [c-indices] 0.50-0.71). Most models had low calibration with overprediction of the observed risk. RECODe outperformed other models across four comparable endpoints for discrimination: all-cause mortality (c-index 0.67, 95% confidence interval [CI] 0.65-0.69), congestive heart failure (c-index 0.71, 95% CI 0.69-0.72), myocardial infarction (c-index 0.67, 95% CI 0.65-0.68); and stroke (c-index 0.65, 95% CI 0.62-0.68), and for calibration (except for all-cause mortality). The UKPDS OM2 had comparable performance to RECODe for all-cause mortality (c-index 0.67, 95% CI 0.66-0.69) and cardiovascular mortality (c-index 0.71, 95% CI 0.70-0.73), but worse performance for other outcomes. The models performed better for younger participants and somewhat better for non-White ethnicities. Models developed from non-Western datasets showed worse performance in our UK-based validation set. CONCLUSIONS: The RECODe model led to better risk estimations in this predominantly White European population. Further validation is needed in non-Western populations to assess generalizability to other populations.

Computationally efficient composite triple beat cancellation for DML-based DA-RoF fronthaul.

The digital-analog radio-over-fiber (DA-RoF) scheme offers a high-fidelity and spectrally efficient solution for future mobile fronthaul. However, to be implemented in the low-cost directly modulated laser with direct detection (DML-DD) link, both the digital and analog parts in DA-RoF modulation would suffer from the composite second-order (CSO) and composite triple beat (CTB) caused by the chirp-dispersion interaction. In this Letter, we propose and experimentally demonstrate a computationally efficient composite triple beat cancellation (CTB-C) algorithm for DA-RoF fronthaul in the dispersion-uncompensated C-band DML-DD link. The CSO and CTB are suppressed at the receiver-side DSP based on the theoretical model of these nonlinear distortions. In the proof-of-concept experiment, a 1.2-dB improvement in the recovered signal-to-noise ratio (SNR) is obtained with 5.5-GHz 1024-QAM orthogonal frequency division multiplexing (OFDM) signal after 10-km standard single-mode fiber (SSMF) transmission. The proposed CTB-C technique does not require the training process and performs close to the Volterra-based feed-forward equalizer (VFE) under the complexity constraint.

Comparative Analyses of Reproductive Caste Types Reveal Vitellogenin Genes Involved in Queen Fertility in Solenopsis invicta.

The red imported fire ant (Solenopsis invicta Buren) is a social pest species with a robust reproductive ability that causes extensive damage. Identification of the genes involved in queen fertility is critical in order to better understand the reproductive biology and screening for the potential molecular targets in S. invicta. Here, we used the mRNA deep sequencing (RNA-seq) approach to identify differentially expressed genes (DEGs) in the transcriptomes of three reproductive caste types of S. invicta, including queen (QA) and winged female (FA) and male (MA) ants. The genes that were specific to and highly expressed in the queens were then screened, and the Vg2 and Vg3 genes were chosen as targets to explore their functions in oogenesis and fertility. A minimum of 6.08 giga bases (Gb) of clean reads was obtained from all samples, with a mapping rate > 89.78%. There were 7524, 7133, and 977 DEGs identified in the MA vs. QA, MA vs. FA, and FA vs. QA comparisons, respectively. qRT-PCR was used to validate 10 randomly selected DEGs, including vitellogenin 2 (Vg2) and 3 (Vg3), and their expression patterns were mostly consistent with the RNA-seq data. The S. invicta Vgs included conserved domains and motifs that are commonly found in most insect Vgs. SiVg2 and SiVg3 were highly expressed in queens and winged females and were most highly expressed in the thorax, followed by the fat body, head, and epidermis. Evaluation based on a loss-of-function-based knockdown analysis showed that the downregulation of either or both of these genes resulted in smaller ovaries, less oogenesis, and less egg production. The results of transcriptional sequencing provide a foundation for clarifying the regulators of queen fertility in S. invicta. The functions of SiVg2 and SiVg3 as regulators of oogenesis highlight their importance in queen fecundity and their potential as targets of reproductive disruption in S. invicta control.

SEA-Net: Structure-Enhanced Attention Network for Limited-Angle CBCT Reconstruction of Clinical Projection Data.

This work aims to improve limited-angle (LA) cone beam computed tomography (CBCT) by developing deep learning (DL) methods for real clinical CBCT projection data, which is the first feasibility study of clinical-projection-data-based LA-CBCT, to the best of our knowledge. In radiation therapy (RT), CBCT is routinely used as the on-board imaging modality for patient setup. Compared to diagnostic CT, CBCT has a long acquisition time, e.g., 60 seconds for a full 360° rotation, which is subject to the motion artifact. Therefore, the LA-CBCT, if achievable, is of the great interest for the purpose of RT, for its proportionally reduced scanning time in addition to the radiation dose. However, LA-CBCT suffers from severe wedge artifacts and image distortions. Targeting at real clinical projection data, we have explored various DL methods such as image/data/hybrid-domain methods and finally developed a so-called Structure-Enhanced Attention Network (SEA-Net) method that has the best image quality from clinical projection data among the DL methods we have implemented. Specifically, the proposed SEA-Net employs a specialized structure enhancement sub-network to promote texture preservation. Based on the observation that the distribution of wedge artifacts in reconstruction images is non-uniform, the spatial attention module is utilized to emphasize the relevant regions while ignores the irrelevant ones, which leads to more accurate texture restoration.

Procedural, Short-Term, and Intermediate-Term Outcomes in Propensity-Matched Patients With Severe Mitral Valve Regurgitation Undergoing Urgent Versus Elective MitraClip Percutaneous Mitral Valve Repair.

OBJECTIVE: The study authors sought to compare outcomes in patients with severe mitral valve regurgitation (MR) undergoing urgent, as compared to elective, mitral valve repair employing MitraClip. They hypothesized that, compared to elective cases, MitraClip procedures performed for urgent indications would be associated with increased intraoperative and postoperative complications but have similar long-term outcomes. DESIGN: A retrospective chart review with 3:1 propensity score matching of elective-to-urgent cases. SETTING: A single, large-volume tertiary care academic medical center. PARTICIPANTS: All consecutive patients with severe MR who underwent elective or urgent MitraClip procedures between December 15, 2015, and October 26, 2020. INTERVENTIONS: MR repair with MitraClip. MEASUREMENTS AND MAIN RESULTS: As expected, patients in the urgent MitraClip group required a higher level of preprocedural care, and there were significant differences in baseline demographic and clinical variables as compared to the elective group. To reduce baseline characteristics heterogeneity, propensity matching was performed for age, left ventricular systolic dysfunction, congestive heart failure, chronic obstructive pulmonary disease, and smoking histories, using the nearest-neighbor matching with a caliper of 0.2 and with replacement. The final study cohort included 89 urgent and 252 matched elective cases, with a suitable alignment between the treatment groups. Propensity-matched urgent MitraClip patients experienced a longer hospital length of stay (p < 0.001), increased intensive care unit admissions (19% v 4%, p < 0.001) and mechanical ventilation (6.7% v 1.6%, p = 0.023), postprocedural atrial fibrillation (11% v 4.4%, p = 0.036), pericardial effusion (10% v 2.4%, p = 0.005), and acute kidney injury (7.9% v 2%, p = 0.016). Furthermore, patients in the urgent cohort incurred significantly higher 30-day cardiovascular mortality (6.7% v 2%, p = 0.039), increased 30-day (16% v 5.6%, p = 0.006), and 1-year (33% v 20%, p = 0.021) readmission rates. However, there were no statistically significant differences in 30-day and 1-year overall and 1-year cardiovascular mortality. CONCLUSIONS: Urgent MitraClip repairs can be performed successfully, when needed, in critically ill patients with severe MR. Despite the procedural success, patients undergoing urgent MitraClip repair remain at high risk for adverse outcomes in the short- and intermediate-term and incur increased cardiovascular mortality and morbidity. Further efforts are required to develop strategies to optimize short and intermediate outcomes in this vulnerable group of patients.

Effect of simulated microgravity conditions of hindlimb unloading on mice hematopoietic and mesenchymal stromal cells.

Conditions in space, such as microgravity, may affect the hematopoietic and bone marrow-derived mesenchymal stromal cells (BM-MSCs) of astronauts. However, to date, few detailed phenotype change data about the different type of hematopoietic cells have reported. In this study, C57BL/6 mice were randomly divided into two groups: a control group (control) and a hindlimb suspension group (treated). After four weeks of hindlimb suspension, we found that this simulated microgravity (sµg) condition could increase the percentage of monocytes and macrophages and decrease the percentage of B lymphocytes and mature red cells in bone marrow. The percentage of B lymphocytes in the spleen and the red blood cell count in peripheral blood also decreased, consistent with the response of bone marrow. The cytoskeleton in the BM-MSCs was disrupted. The expression levels of hematopoietic-related genes, such as fms-like tyrosine kinase-3 ligand, granulocyte-macrophage colony stimulating factor, interleukin-3, and adipogenic differentiation associated genes, leptin and proliferator-activated receptor γ type 2, were upregulated under sµg conditions. These results indicated that simulating microgravity can affect the phenotype of certain types of hematopoietic cells and the morphology and gene expression pattern of BM-MSCs.

Multiple Hydrogen Bonds-Reinforced Hydrogels with High Strength, Shape Memory, and Adsorption Anti-Inflammatory Molecules.

The research on multiple hydrogen bonds (H-bonds) hydrogels have gradually aroused wide interest. In this paper, a multiple H-bonds-reinforced poly(acrylamide-co-2-vinyl-4,6-diamino-2-vinyl-1,3,5-triazine)/tannic acid (P(Am-co-VDT)/TA) hydrogels are prepared. The results suggest that the prepared hydrogel has two types of H-bonds crosslinking regions: A "soft" region of H-bonds between the diaminotriazine (DAT) moieties on the polymer chains and the TA pyrogallol/catechol groups, and a "hard" region of H-bonds forming by DAT moieties with itself. The hard crosslinking region exhibits significantly higher activation energy than the soft region. Such soft and hard dual physically crosslinked networks dramatically enhance the mechanical properties of P(Am-co-VDT)/TA hydrogels in a synergistic manner (tensile strength is 2.34 MPa, elongation at break is 410%). Due to the multiple hydrogen bonds, the hydrogel has good pH sensitivity and rapid response to shape memory within a few minutes. In addition, the hydrogels have the capacity of physical adsorption of the anti-inflammatory drug diclofenac sodium and other molecules with a specific spatially arranged chemical composition. These hydrogels with high mechanical strength, excellent shape memory behavior, and capacity of adsorption of anti-inflammatory drug could be attractive candidates for applications in the fields of biomedicine, tissue engineering, and medical materials.

Cyclophilin D participates in the inhibitory effect of high-fat diet on the expression of steroidogenic acute regulatory protein.

OBJECTIVE: The high-fat diet (HFD)-induced obesity is responsible for the testosterone deficiency (TD). However, the mechanism remains unknown. Mitochondrial homeostasis is proved to be important for maintaining the function of steroidogenic acute regulatory protein (StAR), the first rate-limiting enzyme in testosterone synthesis. As the key regulator of mitochondrial membrane permeability, cyclophilin D (CypD) plays a crucial role in maintaining mitochondrial function. In this study, we sought to elucidate the role of CypD in the expression of StAR affected by HFD. METHODS: To analyse the influence of CypD on StAR in vivo and in vitro, mouse models of HFD, CypD overexpression and CypD knockout (Ppif-/- ) as well as Leydig cells treated with palmitic acid (PA) and CypD overexpression plasmids were examined with an array of metabolic, mitochondrial function and molecular assays. RESULTS: Compared with the normal diet mice, consistent with reduced testosterone in testes, the expressions of StAR in both mRNA and protein levels in HFD mice were down-regulated, while expressions of CypD were up-regulated. High-fat intake impaired mitochondrial function with the decrease in StAR in Leydig cells. Overexpression of CypD inhibited StAR expressions in vivo and in vitro. Compared with C57BL/6 mice with HFD, expressions of StAR were improved in Ppif-/- mice with HFD. CONCLUSIONS: Mitochondrial CypD involved in the inhibitory effect of HFD on StAR expression in testes.

Hepatocyte growth factor enhances the inflammation-alleviating effect of umbilical cord-derived mesenchymal stromal cells in a bronchiolitis obliterans model.

BACKGROUND AIMS: Specific and effective therapy for prevention or reversal of bronchiolitis obliterans (BO) is lacking. In this study, we evaluated the therapeutic effect of hepatocyte growth factor (HGF) gene modified mesenchymal stromal cells (MSCs) on BO. METHODS: A mouse model of experimental BO was established by subcutaneously transplanting the tracheas from C57BL/6 mice into Balb/C recipients, which were then administered saline, Ad-HGF-modified human umbilical cord-MSCs (MSCs-HGF) or Ad-Null-modified MSCs (MSCs-Null). The therapeutic effects of MSCs-Null and MSCs-HGF were evaluated by using fluorescence-activated cell sorting (FACS) for lymphocyte immunophenotype of spleen, enzyme-linked immunosorbent assay (ELISA) and real-time polymerase chain reaction (rt-PCR) for cytokine expression, and histopathological analysis for the transplanted trachea. RESULTS: The histopathologic recovery of allograft tracheas was improved significantly after MSCs-Null and MSCs-HGF treatment and the beneficial effects were particularly observed in MSCs-HGF-treated mice. Furthermore, the allo-transplantation-induced immunophenotype disorders of the spleen, including regulatory T (Treg), T helper (Th)1, Th2 and Th17, were attenuated in both cell-treated groups. MSCs-HGF treatment reduced expression and secretion of inflammation cytokines interferon-gamma (IFN-γ), and increased expression of anti-inflammatory cytokine interleukin (IL)-4 and IL-10. It also decreased the expression level of the profibrosis factor transforming growth factor (TGF)-ß. CONCLUSION: Treatment of BO with HGF gene modified MSCs results in reduction of local inflammation and promotion in recovery of allograft trachea histopathology. These findings might provide an effective therapeutic strategy for BO.

Free triiodothyronine levels are positively associated with non-alcoholic fatty liver disease in euthyroid middle-aged subjects.

BACKGROUND: Studies on the relationship between thyroid function and non-alcoholic fatty liver disease (NAFLD) among euthyroid subjects have produced conflicting results. OBJECTIVES: The aim of this study was to investigate the association between thyroid function and the presence of NAFLD in a large-sample middle-aged euthyroid subjects. METHODS: A total of 2576 euthyroid subjects who underwent health check-up were included. NAFLD was diagnosed by hepatic ultrasonography. Conventional risk factors for NAFLD were assessed as well as serum levels of TSH, FT3 and FT4. RESULTS: Levels of FT3 were significantly higher in NAFLD group (5.12 ± 0.58 versus 4.84 ± 0.58 pmol/L, adjusted p = 0.000) than non-NAFLD group, while levels of TSH and FT4 were comparable between NAFLD and non-NAFLD groups (TSH: 2.13 ± 0.90 versus 2.20 ± 0.93 mIU/L, adjusted p = 0.190; FT4: 16.41 ± 2.04 versus 16.18 ± 2.06 pmol/L, adjusted p = 0.146, respectively). Levels of FT3 were positively correlated with components of metabolic syndrome. Multivariate logistic regression analysis revealed that high level of FT3 was an independent predictor for NAFLD (odds ratio: 1.253, p = 0.040). The relationship between FT4 and NAFLD in women was different according to menopausal status, with negative association in pre-menopausal women (OR: 0.777, 95% CI: 0.617-0.979, p = 0.032) and null association in post-menopausal women (OR: 1.037, 95% CI: 0.841-1.277, p = 0.736). CONCLUSIONS: Our findings suggested that high levels of FT3 were significantly associated with NAFLD among middle-aged euthyroid subjects independently of known metabolic risk factors. A negative correlation of serum FT4 level with NAFLD was only observed in pre-menopausal women.

[Effect of anxin granules combined with tirofiba on patients with acute myocardial infarction after elective percutaneous coronary intervention].

To investigate the influence of Anxin granules combined with tirofiban on acute myocardial infarction (AMI) Patients after elective percutaneous coronary intervention (PCI). One hundred and twenty AMI patients were randomly divided into treatment group and control group. The patients in the two groups were all given Tirofiban 30mins before PCI . The treatment group was added Anxin granules 30 mins before and after PCI. Tissue factor (TF) and von willebrand factor (vWF) were tested at 6 hours after operation. Syndromatology alteration of traditional Chinese medicine (TCM) and bleeding complications were observed at 4 weeks after operation. Both TF and vWF at 6 hours after operation of the treatment group was lower than the control group significantly (P < 0.01), while the condition of myocardial ischemia at 90 mins after operation of the treatment group was better than control group with significance. The syndromatology alteration of TCM especially spontaneous perspiration and hypodynamia of the treatment group were improved significantly compared to control group 4 weeks after operation. All patients in both groups had no bleeding complications and thrombopenia. The study suggests that Anxin granules combined with tirofiba can improve the clinical efficacy and the endothelial function of AMI patients after PCI with no increase in bleeding events.

A rare case of infected urinothorax.

Urinothorax is a rare cause of pleural effusion. Infected urinothorax is even rarer. Here we present a case of infected urinothorax from renal mass causing obstructive uropathy. Patient improved with pleural drainage and a multidisciplinary approach of treatment between team involving urologist and pulmonologist. This case highlights the complexity in the diagnosis and management of infected urinothorax.

Deep convolutional dictionary learning network for sparse view CT reconstruction with a group sparse prior.

Purpose Numerous techniques based on deep learning have been utilized in sparse view computed tomography (CT) imaging. Nevertheless, the majority of techniques are instinctively constructed utilizing state-of-the-art opaque convolutional neural networks (CNNs) and lack interpretability. Moreover, CNNs tend to focus on local receptive fields and neglect nonlocal self-similarity prior information. Obtaining diagnostically valuable images from sparsely sampled projections is a challenging and ill-posed task. Method To address this issue, we propose a unique and understandable model named DCDL-GS for sparse view CT imaging. This model relies on a network comprised of convolutional dictionary learning and a nonlocal group sparse prior. To enhance the quality of image reconstruction, we utilize a neural network in conjunction with a statistical iterative reconstruction framework and perform a set number of iterations. Inspired by group sparsity priors, we adopt a novel group thresholding operation to improve the feature representation and constraint ability and obtain a theoretical interpretation. Furthermore, our DCDL-GS model incorporates filtered backprojection (FBP) reconstruction, fast sliding window nonlocal self-similarity operations, and a lightweight and interpretable convolutional dictionary learning network to enhance the applicability of the model. Results The efficiency of our proposed DCDL-GS model in preserving edges and recovering features is demonstrated by the visual results obtained on the LDCT-P and UIH datasets. Compared to the results of the most advanced techniques, the quantitative results are enhanced, with increases of 0.6-0.8 dB for the peak signal-to-noise ratio (PSNR), 0.005-0.01 for the structural similarity index measure (SSIM), and 1-1.3 for the regulated Fréchet inception distance (rFID) on the test dataset. The quantitative results also show the effectiveness of our proposed deep convolution iterative reconstruction module and nonlocal group sparse prior. Conclusion In this paper, we create a consolidated and enhanced mathematical model by integrating projection data and prior knowledge of images into a deep iterative model. The model is more practical and interpretable than existing approaches. The results from the experiment show that the proposed model performs well in comparison to the others.

A New Biocontrol Agent Bacillus velezensis SF334 against Rubber Tree Fungal Leaf Anthracnose and Its Genome Analysis of Versatile Plant Probiotic Traits.

Natural rubber is an important national strategic and industrial raw material. The leaf anthracnose of rubber trees caused by the Colletotrichum species is one of the important factors restricting the yields of natural rubber. In this study, we isolated and identified strain Bacillus velezensis SF334, which exhibited significant antagonistic activity against both C. australisinense and C. siamense, the dominant species of Colletotrichum causing rubber tree leaf anthracnose in the Hainan province of China, from a pool of 223 bacterial strains. The cell suspensions of SF334 had a significant prevention effect for the leaf anthracnose of rubber trees, with an efficacy of 79.67% against C. siamense and 71.8% against C. australisinense. We demonstrated that SF334 can lead to the lysis of C. australisinense and C. siamense mycelia by causing mycelial expansion, resulting in mycelial rupture and subsequent death. B. velezensis SF334 also harbors some plant probiotic traits, such as secreting siderophore, protease, cellulase, pectinase, and the auxin of indole-3-acetic acid (IAA), and it has broad-spectrum antifungal activity against some important plant pathogenic fungi. The genome combined with comparative genomic analyses indicated that SF334 possesses most genes of the central metabolic and gene clusters of secondary metabolites in B. velezensis strains. To our knowledge, this is the first time a Bacillus velezensis strain has been reported as a promising biocontrol agent against the leaf anthracnose of rubber trees caused by C. siamense and C. australisinense. The results suggest that B. velezensis could be a potential candidate agent for the leaf anthracnose of rubber trees.

Long non-coding RNA-NONMMMUT004552.2 regulates the unloading-induced bone loss through the miRNA-15b-5p/Syne1 in mice.

Exercise-induced mechanical loading can increase bone strength whilst mechanical unloading enhances bone-loss. Here, we investigated the role of lncRNA NONMMUT004552.2 in unloading-induced bone-loss. Knockout of lncRNA NONMMUT004552.2 in hindlimb-unloaded mice caused an increase in the bone formation and osteoblast activity. The silencing of lncRNA NONMMUT004552.2 also decreased the osteoblast apoptosis and expression of Bax and cleaved caspase-3, increased Bcl-2 protein expression in MC3T3-E1 cells. Mechanistic investigations demonstrated that NONMMUT004552.2 functions as a competing endogenous RNA (ceRNA) to facilitate the protein expression of spectrin repeat containing, nuclear envelope 1 (Syne1) by competitively binding miR-15b-5p and subsequently inhibits the osteoblast differentiation and bone formation in the microgravity unloading environment. These data highlight the importance of the lncRNA NONMMUT004552.2/miR-15b-5p/Syne1 axis for the treatment of osteoporosis.

A cross-sectional mental-health survey of Chinese postgraduate students majoring in stomatology post COVID-19 restrictions.

Background: The psychological status of Chinese postgraduate students majoring in stomatology after the COVID-19 restrictions still remains unclear. The objective of this study is to evaluate the mental status through a cross-sectional survey and gather related theoretical evidence for psychological intervention on postgraduate students majoring in stomatology. Methods: An online survey was administered, and subjective well-being, anxiety, stress and depression symptoms were assessed using the 5-item World Health Organization Well-Being Index (WHO-5), item Generalized Anxiety Disorder Scale (GAD-7), 10-item Perceived Stress Scale (PSS-10), and Patient Health Questionnaire-9 (PHQ-9), respectively, wherein suicidal ideation and sleep-related problems were measured with PHQ-9 and Insomnia Severity Index (ISI). Results: A total of 208 participants who completed one questionnaire were considered as valid. It was found that female respondents generally exhibited significantly higher levels of PSS-10, PHQ-9, and GAD-7 scores and shorter physical activity hours than male students. Students from rural areas demonstrated significantly higher levels of PHQ-9, suicidal ideation, and less portion of good or fair family economic support. Additionally, individuals from only-child families reported increased levels of activity hours (1.78 ± 2.07, p = 0.045) and a higher portion (55.10%, p = 0.007) of having clear future plan as compared with multiple-child families. The risk factors for anxiety symptoms (GAD-7 score) were higher scores of PSS-10 (OR = 1.15, 95% CI = 1.09-1.22), PHQ-9 (OR = 1.35, 95% CI = 1.22-1.49), and ISI-7 (OR = 1.14, 95% CI = 1.06-1.23), while owning a clear graduation plan was the protective factor (OR = 0.55, 95% CI = 0.31-0.98). Moreover, the risk factors for depressive symptoms (PHQ-9) included PSS-10 (OR = 1.10, 95% CI = 1.04-1.16), GAD-7 (OR = 1.38, 95% CI = 1.25-1.52), suicidal ideation (OR = 5.66, 95% CI = 3.37-9.51), and ISI-7 (OR = 1.17, 95% CI = 1.09-1.25). Approximately 98.08% of Chinese postgraduates studying stomatology reported experiencing at least moderate stress after the COVID-19 restrictions. Conclusion: Within the limitations of this study, senior students were more inclined to stress, while anxiety symptoms were related to severer levels of stress, depression, and insomnia. Depressive symptoms were associated with higher levels of stress, anxiety, insomnia, suicidal ideation, and lower levels of self-reported well-being. Thus, psychological interventions for postgraduates should be timely and appropriately implemented by strengthening well-being, reasonably planning for the future, and good physique, thereby mitigating the psychological issues after COVID-19 restrictions.

Linear convergence of the subspace constrained mean shift algorithm: from Euclidean to directional data.

This paper studies the linear convergence of the subspace constrained mean shift (SCMS) algorithm, a well-known algorithm for identifying a density ridge defined by a kernel density estimator. By arguing that the SCMS algorithm is a special variant of a subspace constrained gradient ascent (SCGA) algorithm with an adaptive step size, we derive the linear convergence of such SCGA algorithm. While the existing research focuses mainly on density ridges in the Euclidean space, we generalize density ridges and the SCMS algorithm to directional data. In particular, we establish the stability theorem of density ridges with directional data and prove the linear convergence of our proposed directional SCMS algorithm.

Dynamic controllable residual generative adversarial network for low-dose computed tomography imaging.

Background: Computed tomography (CT) imaging technology has become an indispensable auxiliary method in medical diagnosis and treatment. In mitigating the radiation damage caused by X-rays, low-dose computed tomography (LDCT) scanning is becoming more widely applied. However, LDCT scanning reduces the signal-to-noise ratio of the projection, and the resulting images suffer from serious streak artifacts and spot noise. In particular, the intensity of noise and artifacts varies significantly across different body parts under a single low-dose protocol. Methods: To improve the quality of different degraded LDCT images in a unified framework, we developed a generative adversarial learning framework with a dynamic controllable residual. First, the generator network consists of the basic subnetwork and the conditional subnetwork. Inspired by the dynamic control strategy, we designed the basic subnetwork to adopt a residual architecture, with the conditional subnetwork providing weights to control the residual intensity. Second, we chose the Visual Geometry Group Network-128 (VGG-128) as the discriminator to improve the noise artifact suppression and feature retention ability of the generator. Additionally, a hybrid loss function was specifically designed, including the mean square error (MSE) loss, structural similarity index metric (SSIM) loss, adversarial loss, and gradient penalty (GP) loss. Results: The results obtained on two datasets show the competitive performance of the proposed framework, with a 3.22 dB peak signal-to-noise ratio (PSNR) margin, 0.03 SSIM margin, and 0.2 contrast-to-noise ratio margin on the Challenge data and a 1.0 dB PSNR margin and 0.01 SSIM margin on the real data. Conclusions: Experimental results demonstrated the competitive performance of the proposed method in terms of noise decrease, structural retention, and visual impression improvement.

Comprehensive control of PM 2.5 capture and ozone emission in two-stage electrostatic precipitators.

Indoor air purification is extremely urgent to eliminate the health threat of PM 2.5, VOCs and microbial aerosol for exposing people, for which ESPs enjoy exceptional advantage for its special high-voltage characteristic. However, the secondary air pollutant of ozone is produced to possibly cause potential risk. In this work, six kinds of two-stage ESPs containing various charger and collector units, whose structure and size design are determined according to the indoor application, are developed to investigate the comprehensive control of PM 2.5 capture and ozone emission. Responsive surface methodology is employed to explore the relationship among ozone concentration, wire number, charger current and airflow velocity, and obtain regression model for predicting ozone emission. The comprehensive evaluation standard considering efficiency-ozone double factors is proposed to optimize structure design and working conditions of two-stage ESPs. Experimental results show that two-stage ESPs with a unit ratio of >3/4 can keep relatively good stable state, whose current reduction is in around 10 µA, for preventing particle charging function of charger from basically affecting. For the two-stage ESP with Ra = 2/5, it finds the optimization of working conditions of collector can bring rapid improvement of collection efficiency for 0.25 µm particles, which reaches up to be >60 %, while the optimization of that of the charger can only result in an enhancement of <30 %. RSM analysis exhibits a strong connection between the interactive effect of charger current and airflow velocity for presenting a steep response surface. Based on comprehensive control of PM 2.5 and ozone pollutants, it suggests the two-stage ESP with Ra = 2/5 is selected at the first priority and then that with Ra = 1/6, while two-stage ESP with Ra = 4/3 is not recommended for unsatisfied consequence of both of PM 2.5 capture and ozone emission.