Deep Learning-Based Localization and Detection of Malpositioned Endotracheal Tube on Portable Supine Chest Radiographs in Intensive and Emergency Medicine: A Multicenter Retrospective Study.

OBJECTIVES: We aimed to develop a computer-aided detection (CAD) system to localize and detect the malposition of endotracheal tubes (ETTs) on portable supine chest radiographs (CXRs). DESIGN: This was a retrospective diagnostic study. DeepLabv3+ with ResNeSt50 backbone and DenseNet121 served as the model architecture for segmentation and classification tasks, respectively. SETTING: Multicenter study. PATIENTS: For the training dataset, images meeting the following inclusion criteria were included: 1) patient age greater than or equal to 20 years; 2) portable supine CXR; 3) examination in emergency departments or ICUs; and 4) examination between 2015 and 2019 at National Taiwan University Hospital (NTUH) (NTUH-1519 dataset: 5,767 images). The derived CAD system was tested on images from chronologically (examination during 2020 at NTUH, NTUH-20 dataset: 955 images) or geographically (examination between 2015 and 2020 at NTUH Yunlin Branch [YB], NTUH-YB dataset: 656 images) different datasets. All CXRs were annotated with pixel-level labels of ETT and with image-level labels of ETT presence and malposition. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: For the segmentation model, the Dice coefficients indicated that ETT would be delineated accurately (NTUH-20: 0.854; 95% CI, 0.824-0.881 and NTUH-YB: 0.839; 95% CI, 0.820-0.857). For the classification model, the presence of ETT could be accurately detected with high accuracy (area under the receiver operating characteristic curve [AUC]: NTUH-20, 1.000; 95% CI, 0.999-1.000 and NTUH-YB: 0.994; 95% CI, 0.984-1.000). Furthermore, among those images with ETT, ETT malposition could be detected with high accuracy (AUC: NTUH-20, 0.847; 95% CI, 0.671-0.980 and NTUH-YB, 0.734; 95% CI, 0.630-0.833), especially for endobronchial intubation (AUC: NTUH-20, 0.991; 95% CI, 0.969-1.000 and NTUH-YB, 0.966; 95% CI, 0.933-0.991). CONCLUSIONS: The derived CAD system could localize ETT and detect ETT malposition with excellent performance, especially for endobronchial intubation, and with favorable potential for external generalizability.

Extending the reach of multi-core fiber via Voronoi constellations with concatenated multilevel coding.

This Letter proposes a novel, to the best of our knowledge, coded modulation scheme for randomly coupled multi-core fiber (RC-MCF) via multidimensional (MD) constellation with concatenated two-level multilevel coding (MLC). In the proposed system, the 16-dimensional (16D) Voronoi constellation (VC), naturally fitting with the 16 degrees of freedom of a four-core fiber (two quadratures, two polarizations, and four cores), is generated by a latticed-based shaping method to provide higher shaping gains. Moreover, combining it with the concatenated two-level MLC can further achieve better performance-complexity trade-off. It is demonstrated by simulation results of long-haul multi-channel RC-MCF transmission that the proposed coded modulation scheme for four-core fiber transmission offers 77% reduction in the number of decoding operations and up to 21% (585 km) reach increase over the conventional bit-interleaved coded modulation scheme for quadrature amplitude modulation.

Enabling endogenous distributed acoustic sensing in a digital subcarrier coherent transmission system.

To monitor the health of the fiber network and its ambient environment in densely populated access/metro network areas, in this Letter, an endogenous distributed acoustic sensing (DAS) has been proposed and achieved in a coherent digital subcarrier multiplexing (DSCM) system. Rather than specially allocating a sensing probe in general integrated communication and sensing schemes, the fractional Fourier transformed (FrFT) training sequence (TS) designated for time/frequency synchronization in DSCM coherent communications has been repurposed for sensing. While achieving excellent synchronization performance of communication, the FrFT-based TS can also be concurrently utilized to perform distributed vibration sensing. Experimental results demonstrate that the FrFT-based timing/frequency synchronization sequence is repurposed to achieve a DAS sensitivity of 70 p ε/Hz at a spatial resolution of 5 m, along with 100-Gb/s 16 quadrature amplitude modulation (QAM) DSCM transmission, without a loss of spectral efficiency.

A xonotlite nanofiber bioactive 3D-printed hydrogel scaffold based on osteo-/angiogenesis and osteoimmune microenvironment remodeling accelerates vascularized bone regeneration.

BACKGROUND: Coordination between osteo-/angiogenesis and the osteoimmune microenvironment is essential for effective bone repair with biomaterials. As a highly personalized and precise biomaterial suitable for repairing complex bone defects in clinical practice, it is essential to endow 3D-printed scaffold the above key capabilities. RESULTS: Herein, by introducing xonotlite nanofiber (Ca6(Si6O17) (OH)2, CS) into the 3D-printed silk fibroin/gelatin basal scaffold, a novel bone repair system named SGC was fabricated. It was noted that the incorporation of CS could greatly enhance the chemical and mechanical properties of the scaffold to match the needs of bone regeneration. Besides, benefiting from the addition of CS, SGC scaffolds could accelerate osteo-/angiogenic differentiation of bone mesenchymal stem cells (BMSCs) and meanwhile reprogram macrophages to establish a favorable osteoimmune microenvironment. In vivo experiments further demonstrated that SGC scaffolds could efficiently stimulate bone repair and create a regeneration-friendly osteoimmune microenvironment. Mechanistically, we discovered that SGC scaffolds may achieve immune reprogramming in macrophages through a decrease in the expression of Smad6 and Smad7, both of which participate in the transforming growth factor-ß (TGF-ß) signaling pathway. CONCLUSION: Overall, this study demonstrated the clinical potential of the SGC scaffold due to its favorable pro-osteo-/angiogenic and osteoimmunomodulatory properties. In addition, it is a promising strategy to develop novel bone repair biomaterials by taking osteoinduction and osteoimmune microenvironment remodeling functions into account.

Correlation of retrobulbar perfusion deficits with glaucomatous visual field defects.

PURPOSE: This study is to evaluate the correlation between retrobulbar perfusion deficits and glaucomatous visual field defects. METHODS: Eighty-four patients with glaucoma and 17 normal subjects serving as controls were selected. Color Doppler imaging (CDI) was used to measure the changes in blood flow parameters in the retrobulbar ophthalmic artery (OA), central retinal artery (CRA), and short posterior ciliary arteries (SPCAs). Visual field testing was performed using a Humphrey perimeter, categorizing the visual field deficits into four stages according to the Advanced Glaucoma Intervention Study (AGIS) scoring method. Subsequently, the correlation of retrobulbar hemodynamic parameter alterations among glaucomatous patients with varying visual field defects was examined. RESULTS: The higher the visual field stage, the lower the peak systolic velocity (PSV) of the OA, CRA, and SPCAs in glaucomatous patients. The CRA had the highest sensitivity to changes in its PSV. The PSV of the temporal SPCA (TSPCA-PSV) was lower in advanced glaucoma than in early-stage glaucoma. The PSVs of the OA, CRA, and TSPCA, as well as the resistance index of the CRA (CRA-RI), were positively correlated with the visual field index and the mean deviation. Except for that of OA, the PSV of the retrobulbar vessels was negatively correlated with the pattern standard deviation (PSD). The OA-PSV and end-diastolic velocity (EDV) of the CRA and TSPCA were lower in patients with superior visual field defects than in those with inferior visual field defects. CONCLUSIONS: Greater severity of visual field defects corresponded to poorer retrobulbar blood flow in glaucomatous patients. Patients suffered significant perfusion impairments in the CRA at the early stage, accompanied by SPCA perfusion disorder at the advanced stage. The presence of a bow-shaped defect in the superior or inferior region of the visual field in moderate-stage glaucoma was closely correlated with retrobulbar vascular EDV. TRIAL REGISTRATION: ChiCTR2200059048 (2022-04-23).

Identification of Novel Prognostic Long Non-coding RNAs in Lung Adenocarcinoma Using WGCNA Analysis.

Long non-coding RNAs play crucial role in the tumorigenesis of lung adenocarcinoma (LUAD). However, the function of a large number of lncRNAs in LUAD has not been investigated yet. Weighted gene correlation network analysis (WGCNA) was applied to construct the co-expression module in the TCGA-LUAD cohort. Protein-protein interaction (PPI) network was used to explore the relationship of genes in the key module. The function of the key module on the prognosis in LUAD was analyzed using GO and KEGG analysis. Finally, we constructed the mRNA-lncRNA co-expression network in the key module to identify the hub lncRNAs that play crucial role in the prognosis in LUAD. The most highly expressed 2500 mRNAs and 2500 lncRNAs in the TCGA-LUAD cohort were clustered into 21 modules. After analyzing the correlation between the module and prognostic clinical traits, the Tan module, consisting of 130 genes, was selected as the key module on the prognosis in LUAD. And then, we found that genes in the key module were majorly enriched in ten multiple signaling pathways. Subsequently, we constructed the mRNA-lncRNA co-expression network based on the genes in the key module. Finally, we identified three lncRNAs and nineteen mRNAs that could be the promising prognostic biomarkers for LUAD. We identified three lncRNAs (MIR99AHG, ADAMTS9-AS2, and AC037459.2) and nineteen mRNAs as potential prognostic biomarkers in LUAD, which provided new insight for prognosis monitoring and therapy development in LUAD.

The association of alcohol consumption with the risk of sarcopenia: a dose-response meta-analysis.

Background: Sarcopenia is defined as a progressive loss of skeletal muscle mass plus a decline in muscle strength and/or reduced physical performance with advancing age. The results of current studies on the relationship between drinking and sarcopenia remain controversial.Objectives: The aim of this meta-analysis was to evaluate the association of alcohol consumption with the risk of sarcopenia.Methods: Systematic searches were conducted without language restrictions from the beginning of each database to September 20, 2023 on PubMed, Embase, Cochrane Library, Web of Science, Wanfang Data, Chinese BioMedical Literature, and China national knowledge infrastructure databases. Meta-analysis was conducted to pool the study-specific odds ratios (ORs) with 95% confidence interval (CI).Results: Sixty-two studies with 454,643 participants were enrolled. The meta-analysis of proportions revealed that alcohol consumption was not associated with the presence of sarcopenia, with a pooled OR of 0.964 (95% CI = 0.912-1.019). Further subgroup analysis indicated that alcohol consumption was correlated with lower risk of sarcopenia in men (OR = 0.763; 95% CI = 0.622-0.938; P = .010). The nonlinear dose-response analysis suggested a J-shaped association between alcohol consumption and the risk of sarcopenia, with a nadir at the amounts of alcohol consumption of 6.6 grams/day (OR = 0.765; 95% CI = 0.608-0.957; P < .05).Conclusions: The results of this meta-analysis indicate that alcohol consumption is not a risk factor for the development of sarcopenia. Any suggestion of a putative protective effect of alcohol should be treated with caution, particularly in light of the overall lack of relationship reported in the present comprehensive meta-analysis.

Enabling cost-effective high-performance vibration sensing in digital subcarrier multiplexing systems.

Enabling communication networks with sensing functionality has attracted significant interest lately. The digital subcarrier multiplexing (DSCM) technology is widely promoted in short-reach scenarios for its inherent flexibility of fine-tuning the spectrum. Its compatibility with large-scale as-deployed coherent architectures makes it particularly suited for cost-sensitive integrated sensing and communication applications. In this paper, we propose a scheme of spectrally integrating the digital linear frequency modulated sensing signal into DSCM signals to achieve simultaneous sensing and communication through shared transmitter. Consequently, this cost-effective scheme has been demonstrated to achieve 100-Gb/s dual-polarization quadrature phase-shift keying (DP-QPSK) and 200-Gb/s dual-polarization 16-ary quadrature amplitude modulation (DP-16QAM) transmission with a distributed acoustic sensing sensitivity of 69 pε/Hz and 88 pε/Hz respectively, at a spatial resolution of 4 m.

Adaptive bias control of optical IQ modulator with low LFM dither and strong fluctuation resistance.

An innovative approach has been proposed for adaptive bias control in optical IQ modulators. In contrast to traditional approaches that utilize sine dither, this method employs a linear frequency modulated (LFM) signal as the dither, associated with the fractional Fourier Transform (FrFT) to extract the bias point drift. The LFM signal, after undergoing FrFT, transforms into a compressed signal (CS) with energy concentration in the fractional domain. Utilizing this signal for bias point monitoring, the proposed method demonstrates robust bias control even in the presence of substantial interferences, as substantiated by comprehensive simulations and experimental investigations. Remarkably, in a 20-Gbaud 16QAM signal transmission, the proposed approach achieves stable control of the bias point for over 4 hours, even in the presence of voltage fluctuations, while effectively reducing the dither amplitude by half. Furthermore, it maintains a low bit error rate (BER) below 10-5 even under intentional external interference.

Reset-free adaptive polarization controller on a silicon-photonic platform for a self-coherent communication system.

To give full play to the advantages of the self-coherent systems in the data center scene, the problem of the random walk of the polarization state of the delivered local oscillator must be solved. An adaptive polarization controller (APC) is an effective solution, with the characteristics of easy integration, low complexity, being reset-free, and so on. In this work, we experimentally demonstrated an endlessly APC based on a Mach-Zehnder interferometer on a silicon-photonic integrated circuit. The APC is thermally tuned with only two control electrodes. It endlessly stabilizes the arbitrary state of polarization (SOP) of the light to a state of equal power of the two orthogonal polarizations (X and Y). A polarization tracking speed of up to 800 rad/s is achieved.

Endogenous BOTDA in the self-homodyne coherent detection transmission system for communication-integrated datacenter temperature monitoring.

This Letter demonstrates the high compatibility of the self-homodyne coherent detection (SHCD) transmission system with the Brillouin optical time-domain analyzer (BOTDA). By fully utilizing the remote delivered local oscillator (LO) light of the transmission system, the first, to the best of our knowledge, endogenously integrated BOTDA subsystem is achieved. The remote delivery of the homologous laser source in the SHCD system ensures the frequency match between the probe light and the pump light of the BOTDA. Furthermore, an injection-locked distributed feedback (DFB) laser is employed to amplify the LO and eliminate the impact induced by the Brillouin gain. The experiment demonstrates that a 16-km distributed temperature sensing based on BOTDA can be insensibly emerged into a 50-Gbaud DP-16QAM SHCD transmission system (400 Gbps/λ/core), achieving a spatial resolution of 3 meters and a temperature accuracy of 1°C. Remarkably, the auxiliary sensing module has negligible impact on the transmission.

SRT1720 attenuates UVA-induced corneal endothelial damage via inhibition of oxidative stress and cellular apoptosis.

Corneal endothelium is mostly sensitive to oxidative pressure and mitochondrial dysfunction. However, the oxidative-antioxidant mechanism of corneal endothelial cells (CECs) remains partially defined. Silent information regulator 1 (SIRT1) is a well-studied therapeutic target of oxidative damage. This study aimed to determine the SIRT1 expression in ultraviolet A (UVA)-induced corneal endothelial damage and explore potential drugs to repair corneal endothelial oxidative injury. In this study, we showed that CECs exhibited cellular apoptosis, reactive oxygen species (ROS) accumulation and decreased SIRT1 expression. In addition, UVA induced the imbalance of mitochondrial homeostasis and function, involving in mitochondrial membrane potential, mitochondrial fusion/fission and mitochondrial energy metabolism. SRT1720, the SIRT1 activator, effectively increased SIRT1 expression and attenuated UVA-induced oxidative damage in CECs. The therapeutic effects of SRT1720 for corneal endothelial oxidative damage were also verified in UVA-irradiated mice model. Our findings indicated that SIRT1 maintained the oxidant-antioxidant balance in corneal endothelium, suggesting a new promising therapeutic target for corneal endothelial dysfunction.

The design of highly conductive and stretchable polymer conductors with low-load nanoparticles.

Highly conductive and stretchable polymer conductors fabricated from conductive fillers and stretchable polymers are urgently needed in flexible electronics, implants, soft robotics, etc. However, polymer conductors encounter the conductivity-stretchability dilemma, in which high-load fillers needed for high conductivity always result in the stiffness of materials. Herein, we propose a new design of highly conductive and stretchable polymer conductors with low-load nanoparticles (NPs). The design is achieved by the self-assembly of surface-modified NPs to efficiently form robust conductive pathways. We employ computer simulations to elucidate the self-assembly of the NPs in the polymer matrices under equilibrium and tensile states. The conductive pathways retain 100% percolation probability even though the loading of the NPs is lowered to ∼2% volume. When the tensile strain reaches 400%, the percolation probability of the ∼2% NP system is still greater than 25%. The theoretical prediction suggests a way for advancing flexible conductive materials.

Synthesis of Chiral 2,3-Dihydrofurans via One-Pot Pd-Catalyzed Asymmetric Allylic Cycloaddition and a Retro-Dieckmann Fragmentation Cascade.

An efficient method for the enantioselective synthesis of 2,3-dihydrofurans bearing a quaternary stereocenter has been developed via Pd-catalyzed asymmetric allylic cycloaddition and a retro-Dieckmann Fragmentation cascade. The asymmetric allylic cycloaddition of vinylethylene carbonates with 3-cyanochromone followed by base-assisted retro-Dieckmann fragmentation proceeded smoothly via a one-pot process to produce chiral 3,4-disubstituted 2,3-dihydrofurans in high yields with excellent enantioselectivities.

Real-time corneal thickness changes during phacoemulsification cataract surgery.

PURPOSE: To observe the changes in corneal thickness during phacoemulsification cataract surgery and to analyze the influencing factors. METHODS: One hundred two patients (102 eyes) with cataracts undergoing phacoemulsification cataract surgery at Shandong Eye Hospital between July and October 2021 were included. Intraoperative OCT was applied to capture real-time images preoperatively, before and after ultrasonic emulsification, at the end of irrigation aspiration and the end of surgery. Then, the corneal thickness at the above time points was measured using Photoshop software. RESULTS: The corneal thickness of 102 cataract patients was 511.79 ± 31.46 µm before operation and 512.71 ± 31.51 µm at the beginning of phacoemulsification, which increased by 0.91 ± 1.48 µm (0.2%). At the end of ultrasonic emulsification, the corneal thickness was 521.58 ± 32.75 µm and 8.87 ± 8.71 µm (1.7%) thicker than that before the procedure. After irrigation aspiration, the corneal thickness reached 528.09 ± 33.87 µm, which increased by 6.52 ± 6.38 µm (1.3%) compared with that of the previous step. At the end of the operation, the corneal thickness was 539.19 ± 33.88 µm, 11.09 ± 10.92 µm, and 27.37 ± 13.64 µm thicker than that of the previous step and the preoperative thickness, respectively, with an overall increase of 5.3%. The differences were statistically significant at all time points (all P < 0.001). Correlation analysis showed that postoperative corneal thickness changes were correlated with age, cataract lens nuclear grade, actual phacoemulsification time (APT), effective phacoemulsification time (EPT), average phacoemulsification energy (APE), total surgery time (TST), cell density (CD), maximum cell area (MAX), and cell area standard deviation (SD) (all P < 0.05), while the changes in thickness were not correlated with gender, cell area coefficient of variation (CV), percentage of hexagonal cells (6A), average cell area (AVE), or minimum cell area (MIN) (all P > 0.05). CONCLUSIONS: During phacoemulsification cataract surgery, corneal thickness gradually increases in real time with the increase of perfusion pressure and intraocular manipulation time. The real-time magnitude of intraoperative corneal thickness change is closely related to lens nucleus hardness, corneal endothelial cell density, ultrasound energy, and time for emulsification.

Effects of Moringa Oleifera Leaf Extract Plus Rosiglitazone on Serum Leptin and Glucose and Lipid Metabolism in Type 2 Diabetic Rats.

Objective: To investigate the effects of Moringa Oleifera Leaf Extract (MOLE) plus rosiglitazone (RSG) on glucose and lipid metabolism, serum leptin, and the Akt/GSK3ß/ß-Catenin signaling pathway in type 2 diabetic (T2D) rats. Methods: Sixty male Sprague-Dawley (SD) rats were randomly divided into six groups: the normal group, the model group, the RSG group, the low- and high-dose MOLE group, and the MOLE+RSG group. The normal group was fed a standard rat diet, while the other groups were given a single intraperitoneal injection of low-dose streptozomycin (STZ) (35 mg/kg) and fed a high-sugar and high-fat diet. After 8 weeks, the treatment outcomes were evaluated by measuring key parameters of blood glucose and lipid metabolism and the protein kinase B (AKT) / Glycogen synthase kinase 3beta (GSK3ß) /ß-Catenin signaling pathway in the T2D rats. Results: Compared with the normal group, the model group showed significantly increased levels of blood glucose, blood lipids, serum leptin, free fatty acid (FFA), and tumor necrosis factor-α (TNF-α). Compared with the model group, the RSG, low-dose MOLE, and high-dose MOLE groups displayed effective control of blood glucose, blood lipids, serum leptin, FFA, and TNF-α. The MOLE+RSG group surpassed the RSG group in regulating glucose, lipid metabolism, and serum leptin levels in T2D rats. In addition, the MOLE+RSG group also had superiority over the RSG group in activating the AKT/GSK3ß/ß-Catenin pathway. Conclusion: MOLE plus RSG can effectively reduce blood glucose and blood lipids in T2DM rats.

Label-Free Quantitative Proteomics Reveal the Mechanisms of Young Wheat (Triticum aestivum L.) Ears' Response to Spring Freezing.

Late spring frost is an important meteorological factor threatening the safe production of winter wheat in China. The young ear is the most vulnerable organ of the wheat plant to spring frost. To gain an insight into the mechanisms underpinning young wheat ears' tolerance to freezing, we performed a comparative proteome analysis of wheat varieties Xumai33 (XM33, freezing-sensitive) and Jimai22 (JM22, freezing-tolerant) under normal and freezing conditions using label-free quantitative proteomic techniques during the anther connective tissue formation phase (ACFP). Under freezing stress, 392 and 103 differently expressed proteins (DEPs) were identified in the young ears of XM33 and JM22, respectively, and among these, 30 proteins were common in both varieties. A functional characterization analysis revealed that these DEPs were associated with antioxidant capacity, cell wall modification, protein folding, dehydration response, and plant-pathogen interactions. The young ears of JM22 showed significantly higher expression levels of antioxidant enzymes, heat shock proteins, and dehydrin under normal conditions compared to those of XM33, which might help to prepare the young ears of JM22 for freezing stress. Our results lead to new insights into understanding the mechanisms in young wheat ears' response to freezing stress and provide pivotal potential candidate proteins required for improving young wheat ears' tolerance to spring frost.

Deep Learning-based Diagnosis and Localization of Pneumothorax on Portable Supine Chest X-ray in Intensive and Emergency Medicine: A Retrospective Study.

PURPOSE: To develop two deep learning-based systems for diagnosing and localizing pneumothorax on portable supine chest X-rays (SCXRs). METHODS: For this retrospective study, images meeting the following inclusion criteria were included: (1) patient age ≥ 20 years; (2) portable SCXR; (3) imaging obtained in the emergency department or intensive care unit. Included images were temporally split into training (1571 images, between January 2015 and December 2019) and testing (1071 images, between January 2020 to December 2020) datasets. All images were annotated using pixel-level labels. Object detection and image segmentation were adopted to develop separate systems. For the detection-based system, EfficientNet-B2, DneseNet-121, and Inception-v3 were the architecture for the classification model; Deformable DETR, TOOD, and VFNet were the architecture for the localization model. Both classification and localization models of the segmentation-based system shared the UNet architecture. RESULTS: In diagnosing pneumothorax, performance was excellent for both detection-based (Area under receiver operating characteristics curve [AUC]: 0.940, 95% confidence interval [CI]: 0.907-0.967) and segmentation-based (AUC: 0.979, 95% CI: 0.963-0.991) systems. For images with both predicted and ground-truth pneumothorax, lesion localization was highly accurate (detection-based Dice coefficient: 0.758, 95% CI: 0.707-0.806; segmentation-based Dice coefficient: 0.681, 95% CI: 0.642-0.721). The performance of the two deep learning-based systems declined as pneumothorax size diminished. Nonetheless, both systems were similar or better than human readers in diagnosis or localization performance across all sizes of pneumothorax. CONCLUSIONS: Both deep learning-based systems excelled when tested in a temporally different dataset with differing patient or image characteristics, showing favourable potential for external generalizability.

Dexmedetomidine Confers Protection Against Neuronal Oxygen Glucose Deprivation-Reperfusion by Regulating SIRT3 Mediated Autophagy.

Dexmedetomidine (Dex) plays protective effects on brain ischemia-reperfusion (I/R) injury, but its mechanism remains unclear. In this study, we aimed to investigate whether Dex protects neurons against I/R injury by activating SIRT3 mediated autophagy. The oxygen glucose deprivation-reperfusion (OGD/R) model was constructed in HT22 cells. Different doses of Dex (50 ng/mL, 100 ng/mL and 500 ng/mL) were treated to observe the changes of autophagy and SIRT3 expression. Further, the mimic of SIRT3 and SIRT3 inhibitor were used to analyze the effects of Dex on the SIRT3 expression in HT22 cells. Additionally, the autophagy inhibitor and AMPK inhibitor were used to analyze the effects of Dex on SIRT3 mediated autophagy. The cells viability, oxidative stress and ATP were observed using assay kits. The mitochondrial membrane potential (MMP) and death were analyzed by flow cytometry. The degree of autophagy was observed by acridine orange staining. Western blotting was used to analyze the expression of autophagy related proteins and AMPK/mTOR pathway related proteins. After Dex treatment, the OGD/R induced cell injury was significantly improved through decreasing the levels of LDH and H2O2, increasing levels of ATP and MMP. Furthermore, Dex increased the degree of autophagy and expression of SIRT3 in OGD/R injured cells. Through overexpression of SIRT3, the OGD/R induced cell injury was also clearly improved. But the SIRT3 inhibitor or autophagy inhibitor covered the roles of Dex. Additionally, AMPK inhibitor played an opposite role compared with the effects of Dex treatment. From this study, the protection mechanism of Dex on neurons I/R injury might related to the activation of SIRT3 mediated autophagy.

Pd-Catalyzed regio- and stereoselective allylic substitution of vinylethylene carbonates with 1,2,4-triazoles.

N 1-Substituted 1,2,4-triazoles are ubiquitous skeletons in medicinal agents, agrochemicals, and organic materials. Herein, an efficient and practical method for the synthesis of N1-allylated 1,2,4-triazoles via Pd-catalyzed allylic substitution of vinylethylene carbonates (VECs) with 1,2,4-triazoles has been developed. By using a catalyst generated in situ from Pd2(dba)3·CHCl3 and DPPE under mild conditions, the process allows rapid access to N1-allylated 1,2,4-triazoles bearing diverse functionalities in high yields with excellent N1-selectivities, linear-selectivities, and Z-stereoselectivities.