174 research outputs found

    Guanylate-binding protein 1 participates in cellular antiviral response to dengue virus

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    BACKGROUND: Dengue virus (DENV), the causative agent of human Dengue hemorrhagic fever, is a mosquito-borne virus found in tropical and sub-tropical regions around the world. Vaccines against DENV are currently unavailable. Guanylate-binding protein 1 (GBP1) is one of the Interferon (IFN) stimulated genes (ISGs) and has been shown important for host immune defense against various pathogens. However, the role of GBP1 during DENV infection remains unclarified. In this study, we evaluated the relevance of GBP1 to DENV infection in in vitro model. FINDINGS: Quantitative RT-PCR (qRT-PCR) and Western blot showed that the expression of mouse Gbp1 was dramatically upregulated in DENV-infected RAW264.7 cells. The intracellular DENV loads were significantly higher in Gbp1 silenced cells compared with controls. The expression levels of selective anti-viral cytokines were decreased in Gbp1 siRNA treated cells, while the transcription factor activity of NF-κB was impaired upon GBP1 silencing during infection. CONCLUSIONS: Our data suggested that GBP1 plays an antiviral role during DENV infection

    Synthesis and Catalytic Activity of Iron Hydride Ligated with Bidentate N-Heterocyclic Silylenes for Hydroboration of Carbonyl Compounds

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    We report the synthesis of a novel bidentate N-heterocyclic silylene (NHSi) ligand, N-(LSi:)-N-methyl-2-pyridinamine (1) (L = PhC­(NtBu)2), and the first bischelate disilylene iron hydride, [(Si,N)­(Si,C)­Fe­(H)­(PMe3)] (2), and monosilylene iron hydride, [(Si,C)­Fe­(H)­(PMe3)3] (2′), through Csp2–H activation of the NHSi ligand. Compounds 1 and 2 were fully characterized by spectroscopic methods and single-crystal X-ray diffraction analysis. Density functional theory calculations indicated the multiple-bond character of the Fe–Si bonds and the π back-donation from Fe­(II) to the Si­(II) center. Moreover, the strong donor character of ligand 1 enables 2 to act as an efficient catalyst for the hydroboration reaction of carbonyl compounds at room temperature. Chemoselective hydroboration is attained under these conditions. This might be the first example of hydroboration of ketones and aldehydes catalyzed by a silylene hydrido iron complex. A catalytic mechanism was suggested and partially experimentally verified

    Cost-effective digital coherent short-reach transmission system with D8QAM and low-complexity DSP

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    We propose a cost-effective digital coherent scheme with low-complexity digital signal processing (DSP) for short-reach optical interconnection. Differential 8-ary quadrature amplitude modulation (D8QAM) with 1-decision-aided adaptive differential decoding bypasses carrier recovery and enables cycle-slip-free operation. We experimentally demonstrate that the receiver sensitivity of 400-Gb/s D8QAM is insensitive to the laser type, and is the same as 400-Gb/s 16QAM in the case of 2-km transmission with a distributed feedback (DFB) laser. The proposed adaptive equalizer (AEQ) using real-valued finite impulse response (FIR) filters and shorter tap lengths for the real-imaginary filters allows hardware-efficient implementation with high robustness to the receiver-side timing skew. In the case of 400-Gb/s D8QAM 10-km transmission, our AEQ achieves comparable performance as conventional 4×4 real-valued multi-input multi-output (MIMO) and the existing simplified AEQs with complexity reduction of 50% and 14% respectively

    Tailoring magnetic behavior of CoFeMnNiX (X = Al, Cr, Ga, and Sn) high entropy alloys by metal doping

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    Magnetic materials with excellent performances are desired for functional applications. Based on the high-entropy effect, a system of CoFeMnNiX (X = Al, Cr, Ga, and Sn) magnetic alloys are designed and investigated. The dramatic change in phase structures from face-centered-cubic (FCC) to ordered body-centered-cubic (BCC) phases, caused by adding Al, Ga, and Sn in CoFeMnNiX alloys, originates from the potent short-range chemical order in the liquid state predicted by ab initio molecular dynamics (AIMD) simulations. This phase transition leads to the significant enhancement of the saturation magnetization (Ms), e.g., the CoFeMnNiAl alloy has Ms of 147.86 Am2/kg. First-principles density functional theory (DFT) calculations on the electronic and magnetic structures reveal that the anti-ferromagnetism of Mn atoms in CoFeMnNi is suppressed especially in the CoFeMnNiAl HEA because Al changes the Fermi level and itinerant electron-spin coupling that lead to ferromagnetism

    Recurrence of solitary fibrous tumor of the pleura with hypoglycemia (Doege–Potter Syndrome): a case report description

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    Hypoglycemia has multiple causes, but the most common is a complication of insulin treatment. In addition to insulin therapy, tumors such as insulinomas of pancreatic origin and extrapancreatic tumors causing paraneoplastic syndromes should also be considered. Solitary fibrous tumors of the pleura (SFTP) is rare tumor, which when associated with hypoglycemia causes Doege-Potter syndrome. This article reports a case of a 69-year-old man with Doege-Potter syndrome and underwent the first surgical resection for SFTP. However, the tumor recurred 9 years later with hypoglycemic symptoms and implant metastasis. This recurrent tumor originated from the visceral pleura, was more aggressive and invaded the diaphragm and parietal pleura. After the second surgical removal of the tumor, the hypoglycemic symptoms disappeared

    Canagliflozin Alleviates Atherosclerosis Progression through Inflammation, Oxidative Stress, and Autophagy in Western Diet-fed ApoE −/− Mice

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    Purpose: This study was aimed at investigating the effect of canagliflozin (Cana) on atherosclerosis and further exploring its potential mechanism. Methods: ApoE −/− mice were fed a Western diet (WD) and randomly divided into a WD group and WD+Cana group. After 15 weeks of canagliflozin treatment, serum levels of fasting insulin and inflammatory cytokines were determined with ELISA kits. HE, Oil Red O, and Masson staining were used to estimate the extent of atherosclerosis. Immunohistochemistry, immunofluorescence, ROS staining, and RT-PCR were used to further investigate Cana’s potential mechanism. Results: Histological analysis indicated that Cana restrained atherosclerotic plaque development. Furthermore, Cana decreased the percentage of F4/80 positive cells, and the areal density of ROS and relative fluorescence intensity of P62, but enhanced the relative fluorescence intensity of LC3 in the aortic root. Analysis of factors associated with the inflammatory response mediated by AP-1, oxidative stress mediated through the ROS/Nrf2 pathway, and autophagy in the aorta indicated elevated mRNA levels of F4/80, MCP-1, VCAM-1, AP-1, ROS, NOX4, P62, NLRP3, and IL-1β, but diminished mRNA levels of Nrf2, GST, eNOS, and LC3, in the WD+Cana group. Conclusion: Canagliflozin may attenuate atherosclerosis by decreasing the inflammatory response mediated by AP-1, alleviating oxidative stress through the ROS/Nrf2 pathway, and enhancing autophagy in WD-fed ApoE −/− mice

    Correlation Between Bioelectrical Impedance Analysis and Chest CT-Measured Erector Spinae Muscle Area: A Cross-Sectional Study

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    BackgroundSkeletal muscle mass (SMM) plays an important part in diverse health and disease states. Bioelectrical impedance analysis (BIA) and computed tomography (CT) are available for its assessment. However, muscle mass assessed by BIA may be influenced by multiple factors. The erector spinae muscle area (ESA) on chest CT is recently presumed to be representative of SMM. This study aimed to derive BIA from the ESA and evaluate the magnitude of association (between ESA measured from chest CT) and BIA.MethodsSubjects hospitalized for health checkups between December 2020 and December 2021, having undergone both BIA (50 kHz, 0.8 mA) and chest CT, were included. ESA was quantified at the level of the 12th thoracic vertebra (T12-ESA) by a standardized semi-automated segmentation algorithm. Low SMM was defined using the Asian Working Group for Sarcopenia criteria. The association between T12-ESA and BIA was then evaluated. Stratified analyses by sex and BMI were also performed.ResultsAmong 606 included subjects (59.7 ± 16.6 years, 63.5% male), 110 (18.2%) had low SMM. BMI in low and normal SMM groups was 20.1 and 24.7 kg/m2, respectively. Current smoking, drinking, chronic obstructive pulmonary disease, and chronic renal dysfunction were more frequently seen in the low SMM group than in the normal SMM group. The final regression model included T12-ESA, weight, BMI, and age, and had an adjusted R2 of 0.806 with BIA. In the validation group, the correlation between T12-ESA-derived BIA and BIA remained high (Pearson correlation = 0.899). Stratified analysis disclosed a stronger correlation between T12-ESA and BIA in male subjects than in female subjects (adjusted R2 = 0.790 vs. adjusted R2 = 0.711, p < 0.05), and a better correlation was observed in obese (BMI ≥ 30 kg/m2) compared with underweight (BMI < 18.5 kg/m2) subjects (adjusted R2 = 0.852 vs. adjusted R2 = 0.723, p < 0.05). Additional analysis revealed a significant correlation between T12-ESA and skeletal muscle cross-sectional area at the 3rd lumbar vertebra (L3-CSA) (adjusted R2 = 0.935, p < 0.001).ConclusionsCT-based assessment of ESA at the T12 level is feasible and correlated well with BIA, especially in male subjects and obese subjects

    SENP1 regulates IFN-γ−STAT1 signaling through STAT3−SOCS3 negative feedback loop

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    Interferon-γ (IFN-γ) triggers macrophage for inflammation response by activating the intracellular JAK−STAT1 signaling. Suppressor of cytokine signaling 1 (SOCS1) and protein tyrosine phosphatases can negatively modulate IFN-γ signaling. Here, we identify a novel negative feedback loop mediated by STAT3−SOCS3, which is tightly controlled by SENP1 via de-SUMOylation of protein tyrosine phosphatase 1B (PTP1B), in IFN-γ signaling. SENP1-deficient macrophages show defects in IFN-γ signaling and M1 macrophage activation. PTP1B in SENP1-deficient macrophages is highly SUMOylated, which reduces PTP1B-induced de-phosphorylation of STAT3. Activated STAT3 then suppresses STAT1 activation via SOCS3 induction in SENP1-deficient macrophages. Accordingly, SENP1-deficient macrophages show reduced ability to resist Listeria monocytogenes infection. These results reveal a crucial role of SENP1-controlled STAT1 and STAT3 balance in macrophage polarization

    Train-your-brain program to reduce depression, anxiety, and stress in stroke survivors: a pilot community-based cognitive intervention study

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    IntroductionStroke is a major cause of death and disability worldwide, and it often results in depression, anxiety, stress, and cognitive impairment in survivors. There is a lack of community-based cognitive interventions for stroke survivors. This pilot single trial aimed to assess the feasibility, acceptability, and perceived effectiveness of a community-based cognitive intervention program called Train-Your-Brain (TYB) for stroke survivors and caregivers. The study focused on improvements in emotional and psychological well-being, as well as cognitive functioning.MethodsA quasi-experimental design was used in this study. A total of 48 participants were recruited and assessed using Depression, Anxiety, Stress Scale – 21 items (DASS-21), Montreal Cognitive Assessment (MoCA) and Symbol Digits Modality Test (SDMT) before and after the intervention. The TYB program consisted of nine sessions and was conducted via the Zoom software application. Participants provided feedback on the program, highlighting areas for improvement.ResultsTwenty-seven stroke survivors and 21 caregivers completed the program. Participants expressed high satisfaction with the TYB program but recommended avoiding assessments in December and customizing the program for stroke survivors and caregivers. Stroke survivors showed significant improvements in depression and stress scores, while caregivers experienced no significant improvements after the program. While there was a slight improvement in stroke survivors’ cognitive scores after the program, it was not statistically significant. Caregivers, however, experienced a significant decline in cognitive scores.DiscussionThe TYB program provided group support and validation, resulting in improved mood and reduced stress among stroke survivors. Cultural collectivism played a significant role in fostering group cohesion. However, the program’s limited focus on caregivers and timing of assessments during the December holidays may have affected the outcomes. The TYB program demonstrated feasibility and potential effectiveness in alleviating psychological distress and enhancing cognitive function among stroke survivors. Future research should explore long-term effects, larger sample sizes, and non-English-speaking populations to enhance generalizability. Tailored interventions for caregivers are necessary

    Emergency tracheal intubation in 202 patients with COVID-19 in Wuhan, China:lessons learnt and international expert recommendations

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    Tracheal intubation in coronavirus disease 2019 (COVID-19) patients creates a risk to physiologically compromised patients and to attending healthcare providers. Clinical information on airway management and expert recommendations in these patients are urgently needed. By analysing a two-centre retrospective observational case series from Wuhan, China, a panel of international airway management experts discussed the results and formulated consensus recommendations for the management of tracheal intubation in COVID-19 patients. Of 202 COVID-19 patients undergoing emergency tracheal intubation, most were males (n=136; 67.3%) and aged 65 yr or more (n=128; 63.4%). Most patients (n=152; 75.2%) were hypoxaemic (Sao2 <90%) before intubation. Personal protective equipment was worn by all intubating healthcare workers. Rapid sequence induction (RSI) or modified RSI was used with an intubation success rate of 89.1% on the first attempt and 100% overall. Hypoxaemia (Sao2 <90%) was common during intubation (n=148; 73.3%). Hypotension (arterial pressure <90/60 mm Hg) occurred in 36 (17.8%) patients during and 45 (22.3%) after intubation with cardiac arrest in four (2.0%). Pneumothorax occurred in 12 (5.9%) patients and death within 24 h in 21 (10.4%). Up to 14 days post-procedure, there was no evidence of cross infection in the anaesthesiologists who intubated the COVID-19 patients. Based on clinical information and expert recommendation, we propose detailed planning, strategy, and methods for tracheal intubation in COVID-19 patients
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