141 research outputs found
Accurate modelling of the optics of high resolution liquid crystal devices including diffractive effects
An accurate method to model the optical behaviour of liquid crystal (LC) devices, particularly suited to devices where diffractive effects are present is described here. An accurate electromagnetic modelling programme that takes into account the full non-uniformity and anisotropy of the LC has been developed. This is combined with an existing in-house LC finite element modelling programme based on the Landau – De Gennes theory, that uses the order tensor representation of the LC orientation and allows an accurate descriptions of structures containing LC defects and small features. The electromagnetic model is based on the total field/scattered field (TF-SF) approach to electromagnetic scattering problems and is implemented using finite differences in the frequency domain (FDFD) in a form that can accommodate perfectly matched layers (PMLs) and periodic boundary conditions. The resultant matrix problem is solved efficiently using an especially adapted form of a sweeping preconditioner and the generalised minimum residual method (GMRes). This method has been implemented in 2D and is demonstrated here with the design and analysis of a reconfigurable blazed phase grating that utilises an LC defect to produce an abrupt fly-back, with the capability of short periods and high diffraction efficiency
Exploiting Spatial-temporal Correlations for Video Anomaly Detection
Video anomaly detection (VAD) remains a challenging task in the pattern
recognition community due to the ambiguity and diversity of abnormal events.
Existing deep learning-based VAD methods usually leverage proxy tasks to learn
the normal patterns and discriminate the instances that deviate from such
patterns as abnormal. However, most of them do not take full advantage of
spatial-temporal correlations among video frames, which is critical for
understanding normal patterns. In this paper, we address unsupervised VAD by
learning the evolution regularity of appearance and motion in the long and
short-term and exploit the spatial-temporal correlations among consecutive
frames in normal videos more adequately. Specifically, we proposed to utilize
the spatiotemporal long short-term memory (ST-LSTM) to extract and memorize
spatial appearances and temporal variations in a unified memory cell. In
addition, inspired by the generative adversarial network, we introduce a
discriminator to perform adversarial learning with the ST-LSTM to enhance the
learning capability. Experimental results on standard benchmarks demonstrate
the effectiveness of spatial-temporal correlations for unsupervised VAD. Our
method achieves competitive performance compared to the state-of-the-art
methods with AUCs of 96.7%, 87.8%, and 73.1% on the UCSD Ped2, CUHK Avenue, and
ShanghaiTech, respectively.Comment: This paper is accepted at IEEE 26TH International Conference on
Pattern Recognition (ICPR) 202
NaoXinTong Inhibits the Development of Diabetic Retinopathy in d
Buchang NaoXinTong capsule (NXT) is a Chinese Materia Medica standardized product extracted from 16 Chinese traditional medical herbs and widely used for treatment of patients with cerebrovascular and cardiovascular diseases in China. Formation of microaneurysms plays an important role in the development of diabetic retinopathy. In this study, we investigated if  NXT can protect diabetic mice against the development of diabetic retinopathy. The db/db mice (~6 weeks old), a diabetic animal model, were divided into two groups and fed normal chow or plus NXT for 14 weeks. During the treatment, fasting blood glucose levels were monthly determined. After treatment, retinas were collected to determine retinal thickness, accumulation of carbohydrate macromolecules, and caspase-3 (CAS-3) expression. Our results demonstrate that administration of NXT decreased fasting blood glucose levels. Associated with the decreased glucose levels, NXT blocked the diabetes-induced shrink of multiple layers, such as photoreceptor layer and outer nuclear/plexiform layers, in the retina. NXT also inhibited the diabetes-induced expression of CAS-3 protein and mRNA, MMP-2/9 and TNFα mRNA, accumulation of carbohydrate macromolecules, and formation of acellular capillaries in the retina. Taken together, our study shows that NXT can inhibit the development of diabetic retinopathy and suggests a new potential application of NXT in clinic
An acquired phosphatidylinositol 4-phosphate transport initiates T-cell deterioration and leukemogenesis
Publisher Copyright: © 2022, The Author(s).Lipid remodeling is crucial for malignant cell transformation and tumorigenesis, but the precise molecular processes involved and direct evidences for these in vivo remain elusive. Here, we report that oxysterol-binding protein (OSBP)-related protein 4 L (ORP4L) is expressed in adult T-cell leukemia (ATL) cells but not normal T-cells. In ORP4L knock-in T-cells, ORP4L dimerizes with OSBP to control the shuttling of OSBP between the Golgi apparatus and the plasma membrane (PM) as an exchanger of phosphatidylinositol 4-phosphate [PI(4)P]/cholesterol. The PI(4)P arriving at the PM via this transport machinery replenishes phosphatidylinositol 4,5-bisphosphate [PI(4,5)P-2] and phosphatidylinositol (3,4,5) trisphosphate [PI(3,4,5)P-3] biosynthesis, thus contributing to PI3K/AKT hyperactivation and T-cell deterioration in vitro and in vivo. Disruption of ORP4L and OSBP dimerization disables PI(4)P transport and T-cell leukemogenesis. In summary, we identify a non-vesicular lipid transport machinery between Golgi and PM maintaining the oncogenic signaling competence initiating T-cell deterioration and leukemogenesis. The oxysterol-binding protein-related protein 4 (ORP4L) is expressed in T-cell acute lymphoblastic leukemia and is required for leukemogenesis. Here the authors show that ORP4L orchestrates the transport of the phospholipid PI(4)P from Golgi to the plasma membrane, contributing to PI3K/AKT hyperactivation and T-cell leukemogenesis.Peer reviewe
Associations between perioperative sleep patterns and clinical outcomes in patients with intracranial tumors: a correlation study
ObjectiveAlthough the quality of perioperative sleep is gaining increasing attention in clinical recovery, its impact role remains unknown and may deserve further exploration. This study aimed to investigate the associations between perioperative sleep patterns and clinical outcomes among patients with intracranial tumors.MethodsA correlation study was conducted in patients with intracranial tumors. Perioperative sleep patterns were assessed using a dedicated sleep monitor for 6 consecutive days. Clinical outcomes were gained through medical records and follow-up. Spearman's correlation coefficient and multiple linear regression analysis were applied to evaluate the associations between perioperative sleep patterns and clinical outcomes.ResultsOf 110 patients, 48 (43.6%) were men, with a median age of 57 years. A total of 618 days of data on perioperative sleep patterns were collected and analyzed. Multiple linear regression models revealed that the preoperative blood glucose was positively related to the preoperative frequency of awakenings (β = 0.125; 95% CI = 0.029–0.221; P = 0.011). The level of post-operative nausea and vomiting was negatively related to perioperative deep sleep time (β = −0.015; 95% CI = −0.027–−0.003; P = 0.015). The level of anxiety and depression was negatively related to perioperative deep sleep time, respectively (β = −0.048; 95% CI = −0.089–0.008; P = 0.020, β = −0.041; 95% CI = −0.076–0.006; P = 0.021). The comprehensive complication index was positively related to the perioperative frequency of awakenings (β = 3.075; 95% CI = 1.080–5.070; P = 0.003). The post-operative length of stay was negatively related to perioperative deep sleep time (β = −0.067; 95% CI = −0.113–0.021; P = 0.005). The Pittsburgh Sleep Quality Index was positively related to perioperative sleep onset latency (β = 0.097; 95% CI = 0.044–0.150; P < 0.001) and negatively related to perioperative deep sleep time (β = −0.079; 95% CI = −0.122–0.035; P < 0.001).ConclusionPerioperative sleep patterns are associated with different clinical outcomes. Poor perioperative sleep quality, especially reduced deep sleep time, has a negative impact on clinical outcomes. Clinicians should, therefore, pay more attention to sleep quality and improve it during the perioperative period.Clinical trial registrationhttp://www.chictr.org.cn, identifier: ChiCTR2200059425
Acute effect of particulate matter pollution on hospital admissions for cause-specific respiratory diseases among patients with and without type 2 diabetes in Beijing, China, from 2014 to 2020
BACKGROUND: Scientific studies have identified various adverse effects of particulate matter (PM) on respiratory disease (RD) and type 2 diabetes (T2D). However, whether short-term exposure to PM triggers the onset of RD with T2D, compared with RD without T2D, has not been elucidated. METHODS: A two-stage time-series study was conducted to evaluate the acute adverse effects of PM on admission for RD and for RD with and without T2D in Beijing, China, from 2014 to 2020. District-specific effects of PM and PM were estimated using the over-dispersed Poisson generalized addictive model after adjusting for weather conditions, day of the week, and long-term and seasonal trends. Meta-analyses were applied to pool the overall effects on overall and cause-specific RD, while the exposure-response (E-R) curves were evaluated using a cubic regression spline. RESULTS: A total of 1550,154 admission records for RD were retrieved during the study period. Meta-analysis suggested that per interquartile range upticks in the concentration of PM corresponded to 1.91% (95% CI: 1.33-2.49%), 2.16% (95% CI: 1.08-3.25%), and 1.92% (95% CI: 1.46-2.39%) increments in admission for RD, RD with T2D, and RD without T2D, respectively, at lag 0-8 days, lag 8 days, and lag 8 days. The effect size of PM was statistically significantly higher in the T2D group than in the group without T2D (z = 3.98, P \u3c 0.01). The effect sizes of PM were 3.86% (95% CI: 2.48-5.27%), 3.73% (95% CI: 1.72-5.79%), and 3.92% (95% CI: 2.65-5.21%), respectively, at lag 0-13 days, lag 13 days, and lag 13 days, respectively, and no statistically significant difference was observed between T2D groups (z = 0.24, P = 0.81). Significant difference was not observed between T2D groups for the associations of PM and different RD and could be found between three groups for effects of PM on RD without T2D. The E-R curves varied by sex, age and T2D condition subgroups for the associations between PM and daily RD admissions. CONCLUSIONS: Short-term PM exposure was associated with increased RD admission with and without T2D, and the effect size of PM was higher in patients with T2D than those without T2D
Cardiolipin externalization mediates prion protein (PrP) peptide 106–126-associated mitophagy and mitochondrial dysfunction
Proper mitochondrial performance is imperative for the maintenance of normal neuronal function to prevent the development of neurodegenerative diseases. Persistent accumulation of damaged mitochondria plays a role in prion disease pathogenesis, which involves a chain of events that culminate in the generation of reactive oxygen species and neuronal death. Our previous studies have demonstrated that PINK1/Parkin-mediated mitophagy induced by PrP106−126 is defective and leads to an accumulation of damaged mitochondria after PrP106−126 treatment. Externalized cardiolipin (CL), a mitochondria-specific phospholipid, has been reported to play a role in mitophagy by directly interacting with LC3II at the outer mitochondrial membrane. The involvement of CL externalization in PrP106−126-induced mitophagy and its significance in other physiological processes of N2a cells treated with PrP106−126 remain unknown. We demonstrate that the PrP106−126 peptide caused a temporal course of mitophagy in N2a cells, which gradually increased and subsequently decreased. A similar trend in CL externalization to the mitochondrial surface was seen, resulting in a gradual decrease in CL content at the cellular level. Inhibition of CL externalization by knockdown of CL synthase, responsible for de novo synthesis of CL, or phospholipid scramblase-3 and NDPK-D, responsible for CL translocation to the mitochondrial surface, significantly decreased PrP106−126-induced mitophagy in N2a cells. Meanwhile, the inhibition of CL redistribution significantly decreased PINK1 and DRP1 recruitment in PrP106−126 treatment but had no significant decrease in Parkin recruitment. Furthermore, the inhibition of CL externalization resulted in impaired oxidative phosphorylation and severe oxidative stress, which led to mitochondrial dysfunction. Our results indicate that CL externalization induced by PrP106−126 on N2a cells plays a positive role in the initiation of mitophagy, leading to the stabilization of mitochondrial function
Distinct miRNAs associated with various clinical presentations of SARS-CoV-2 infection.
MicroRNAs (miRNAs) have been shown to play important roles in viral infections, but their associations with SARS-CoV-2 infection remain poorly understood. Here, we detected 85 differentially expressed miRNAs (DE-miRNAs) from 2,336 known and 361 novel miRNAs that were identified in 233 plasma samples from 61 healthy controls and 116 patients with COVID-19 using the high-throughput sequencing and computational analysis. These DE-miRNAs were associated with SASR-CoV-2 infection, disease severity, and viral persistence in the patients with COVID-19, respectively. Gene ontology and KEGG pathway analyses of the DE-miRNAs revealed their connections to viral infections, immune responses, and lung diseases. Finally, we established a machine learning model using the DE-miRNAs between various groups for classification of COVID-19 cases with different clinical presentations. Our findings may help understand the contribution of miRNAs to the pathogenesis of COVID-19 and identify potential biomarkers and molecular targets for diagnosis and treatment of SARS-CoV-2 infection
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