Sodium tanshinone IIA sulfonate inhibits tumor growth via miR-138 upregulation in intermittent hypoxia-induced xenograft mice.

PURPOSE: We studied the functions of sodium tanshinone IIA sulfonate (TSA) in inducing tumor growth in obstructive sleep apnea (OSA)-mimicking intermittent hypoxia (IH) xenograft mice and the underlying potential molecular mechanism. METHODS: RNA sequencing was conducted to screen the differentially expressed microRNAs in cell lines exposed to IH with or without TSA treatment. As part of the 5-week in vivo study, we treated xenograft mice with 8-h IH once daily. TSA and miR-138 inhibitors or mimics were administrated appropriately. In addition, we performed real-time quantitative polymerase chain reaction (RT-PCR), Western blotting, enzyme-linked immunosorbent assay (ELISA), immunohistochemistry (IHC), microvessel density (MVD), and terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assays. RESULTS: RNA sequencing and RT-PCR results demonstrated that TSA increased the levels of miR-138 under IH conditions in vitro. TSA reduced the IH-stimulated high levels of hypoxia-induced factor-1α and vascular endothelial growth factor. Furthermore, IH contributed to high tumor migration, invasion, MVD, and low apoptosis. TSA attenuated IH-mediated tumor proliferation, migration, invasion, MVD, and increased apoptosis, whereas miR-138 inhibitor interrupted the effect of TSA on treating IH-induced tumor behaviors. CONCLUSIONS: OSA mimicking IH facilitates tumor growth and reduces miR-138 levels. TSA inhibits IH-induced tumor growth by upregulating the expression of miR-138.

A ratiometric fluorescence platform based on WS2 QDs/CoOOH nanosheet system for α-glucosidase activity detection.

In this study, we have constructed a ratiometric fluorescence sensor for sensitive sensing of α-glucosidase activity based on WS2 QDs/ CoOOH nanosheet system. In this system, as an oxidase-imimicking nanomaterial, CoOOH nanosheet could convert o-phenylenediamine into 2,3-diaminophenazine (DAP), which had a high fluorescence emission at 575 nm. The DAP subsequently could quench the fluorescence of WS2 QDs via the inner filter effect (IFE). L-Ascorbic acid-2-O-α-D-glucopyranose could be hydrolyzed by α-glucosidase to yield ascorbic acid. CoOOH nanosheet can be converted to Co2+ ions by ascorbic acid, leading to the fluorescence decrease of DAP and the fluorescence recovery of WS2 QDs. Therefore, a novel ratio fluorescence sensing strategy was established for α-glucosidase detection based on WS2 QDs/CoOOH nanosheet system. This WS2 QDs/CoOOH nanosheet system has a low detection limit of 0.009 U/mL for α-Glu assay. The proposed strategy succeeded in detecting α-Glu in human serum samples.

Entropy stabilized cubic Li7La3Zr2O12 with reduced lithium diffusion activation energy: studied using solid-state NMR spectroscopy.

Stabilizing cubic polymorph of Li7La3Zr2O12 at low temperatures is challenging and currently limited to mono- or dual-ion doping with aliovalent ions. Herein, a high-entropy strategy at the Zr sites was deployed to stabilize the cubic phase and lower the lithium diffusion activation energy, evident from the static 7Li and MAS 6Li NMR spectra.

Robust transformed l1 metric for fluorescence molecular tomography.

BACKGROUND AND OBJECTIVE: Fluorescence molecular tomography (FMT) is a non-invasive molecular imaging modality that can be used to observe the three-dimensional distribution of fluorescent probes in vivo. FMT is a promising imaging technique in clinical and preclinical research that has attracted significant attention. Numerous regularization based reconstruction algorithms have been proposed. However, traditional algorithms that use the squared l2-norm distance usually exaggerate the influence of noise and measurement and calculation errors, and their robustness cannot be guaranteed. METHODS: In this study, we propose a novel robust transformed l1 (TL1) metric that interpolates l0 and l1 norms through a nonnegative parameter α∈(0,+∞). The TL1 metric looks like the lp-norm with p∈(0,1). These are markedly different because TL1 metric has two properties, boundedness and Lipschitz-continuity, which make the TL1 criterion suitable distance metric, particularly for robustness, owing to its stronger noise suppression. Subsequently, we apply the proposed metric to FMT and build a robust model to reduce the influence of noise. The nonconvexity of the proposed model made direct optimization difficult, and a continuous optimization method was developed to solve the model. The problem was converted into a difference in convex programming problem for the TL1 metric (DCATL1), and the corresponding algorithm converged linearly. RESULTS: Various numerical simulations and in vivo bead-implanted mouse experiments were conducted to verify the performance of the proposed method. The experimental results show that the DCATL1 algorithm is more robust than the state-of-the-art approaches and achieves better source localization and morphology recovery. CONCLUSIONS: The in vivo experiments showed that DCATL1 can be used to visualize the distribution of fluorescent probes inside biological tissues and promote preclinical application in small animals, demonstrating the feasibility and effectiveness of the proposed method.

Prognostic value of feature-tracking right ventricular longitudinal strain in heart transplant recipients.

OBJECTIVES: The prognostic value of cardiac magnetic resonance feature tracking (CMR-FT)-derived right ventricular longitudinal strain (RVLS) post-heart transplantation has not been studied. This study aimed to evaluate the prognostic significance of CMR-FT-derived RVLS, in patients post- heart transplantation and to directly compare its value with that of conventional RV ejection fraction (RVEF). METHODS: In a cohort of consecutive heart transplantation recipients who underwent CMR for surveillance, RVLS from the free wall was measured by CMR-FT. The composite endpoint was all-cause death or major adverse cardiac events. The Cox regression model was used to examine the independent association between RVLS and the endpoint. RESULTS: A total of 96 heart transplantation recipients were retrospectively included. Over a median follow-up of 41 months, 20 recipients reached the composite endpoint. The multivariate Cox analysis showed that the model with RVLS (hazard ratio [HR]:1.334; 95% confidence interval [CI]:1.148 to 1.549; p < 0.001; Akaike information criterion [AIC] = 140, C-index = 0.831) was better in predicting adverse events than the model with RVEF (HR:0.928; 95% CI: 0.868 to 0.993; p = 0.030; AIC = 149, C-index = 0.751). Furthermore, receiver operating characteristic curves revealed that the accuracy for predicting adverse events was greater for RVLS than RVEF (area under the curve: 0.85 vs 0.76, p = 0.03). CONCLUSIONS: CMR-FT-derived RVLS is an independent predictor of adverse events in post-heart transplantation, and its predictive value was better than RVEF. Therefore, our study highlighted the importance of evaluating RVLS for risk stratification after heart transplantation. KEY POINTS: • CMR-RVLS is an independent predictor of adverse events post-heart transplantation and provides greater predictive value. • CMR-RVLS may help clinicians to risk stratification in heart transplantation recipients.

Correntropy-induced metric with Laplacian kernel for robust fluorescence molecular tomography.

Fluorescence molecular tomography (FMT), which is used to visualize the three-dimensional distribution of fluorescence probe in small animals via the reconstruction method, has become a promising imaging technique in preclinical research. However, the classical reconstruction criterion is formulated based on the squared l 2-norm distance metric, leaving it prone to being influenced by the presence of outliers. In this study, we propose a robust distance based on the correntropy-induced metric with a Laplacian kernel (CIML). The proposed metric satisfies the conditions of distance metric function and contains first and higher order moments of samples. Moreover, we demonstrate important properties of the proposed metric such as nonnegativity, nonconvexity, and boundedness, and analyze its robustness from the perspective of M-estimation. The proposed metric includes and extends the traditional metrics such as l 0-norm and l 1-norm metrics by setting an appropriate parameter. We show that, in reconstruction, the metric is a sparsity-promoting penalty. To reduce the negative effects of noise and outliers, a novel robust reconstruction framework is presented with the proposed correntropy-based metric. The proposed CIML model retains the advantages of the traditional model and promotes robustness. However, the nonconvexity of the proposed metric renders the CIML model difficult to optimize. Furthermore, an effective iterative algorithm for the CIML model is designed, and we present a theoretical analysis of its ability to converge. Numerical simulation and in vivo mouse experiments were conducted to evaluate the CIML method's performance. The experimental results show that the proposed method achieved more accurate fluorescent target reconstruction than the state-of-the-art methods in most cases, which illustrates the feasibility and robustness of the CIML method.

Atorvastatin attenuates intermittent hypoxia-induced myocardial oxidative stress in a mouse obstructive sleep apnea model.

Chronic intermittent hypoxia (CIH), a hallmark of obstructive sleep apnea (OSA), is associated with various cardiovascular diseases. In the present study, we assessed the effect of the lipid reducing agent atorvastatin on CIH-induced myocardial oxidative stress and apoptosis in a mouse OSA model. Forty-eight C57BL/6J mice were evenly divided among normoxia + vehicle, normoxia + atorvastatin, CIH + vehicle, and CIH + atorvastatin groups. CIH consisted of a hypoxia-reoxygenation cycle in which oxygen concentrations fluctuated from 21% to 6% and back over two minutes for 8 hours each day (30 events/hour). CIH exposure continued for 12 weeks. Atorvastatin (5 mg/kg) was administered from week 6 through the end of the experiment. CIH increased malondialdehyde levels and decreased superoxide dismutase activity, total antioxidant capacity, and nuclear factor erythroid 2-related factor 2 levels in cardiac tissue, indicating a reduction in antioxidant activity. Atorvastatin significantly reversed those effects (p < 0.05). CIH also increased B-cell lymphoma 2-associated protein X and cleaved caspased-3 levels as well as the myocardial apoptotic rate, as indicated by terminal deoxynucleotidyl transferase dUTP nick-end labeling. Atorvastatin had no effect on those changes (p > 0.05). Thus, atorvastatin administration exerts antioxidant but not anti-apoptotic effects after CIH and may therefore have therapeutic potential in OSA patients with cardiovascular comorbidities.

FSD-BRIEF: A Distorted BRIEF Descriptor for Fisheye Image Based on Spherical Perspective Model.

Fisheye images with a far larger Field of View (FOV) have severe radial distortion, with the result that the associated image feature matching process cannot achieve the best performance if the traditional feature descriptors are used. To address this challenge, this paper reports a novel distorted Binary Robust Independent Elementary Feature (BRIEF) descriptor for fisheye images based on a spherical perspective model. Firstly, the 3D gray centroid of feature points is designed, and the position and direction of the feature points on the spherical image are described by a constructed feature point attitude matrix. Then, based on the attitude matrix of feature points, the coordinate mapping relationship between the BRIEF descriptor template and the fisheye image is established to realize the computation associated with the distorted BRIEF descriptor. Four experiments are provided to test and verify the invariance and matching performance of the proposed descriptor for a fisheye image. The experimental results show that the proposed descriptor works well for distortion invariance and can significantly improve the matching performance in fisheye images.

Benzene Ring Knitting Achieved by Ambient-Temperature Dehalogenation via Mechanochemical Ullmann-Type Reductive Coupling.

The current approaches capable of affording conjugated porous networks (CPNs) still rely on solution-based coupling reactions promoted by noble metal complexes or Lewis acids, on-surface polymerization conducted in ultrahigh-vacuum environment at very high temperatures (>200 °C), or mechanochemical Scholl-type reactions limited to electron-rich substrates. To develop simple and scalable approaches capable of making CPNs under neat and ambient conditions, herein, a novel and complementary method to the current oxidative Scholl coupling processes is demonstrated to afford CPNs via direct aromatic ring knitting promoted by mechanochemical Ullmann-type reactions. The key to this strategy lies in the dehalogenation of aromatic halides in the presence of Mg involving the formation of Grignard reagent intermediates. Products (Ph-CPN-1) obtained via direct CC bond formation between 1,2,4,5-tetrabromobenzene (TBB) monomer feature high surface areas together with mesoporous architecture. The versatility of this approach is confirmed by the successful construction of various CPNs via knitting of the corresponding aromatic rings (e.g., pyrene and triphenylene), and even highly crystalline graphite product was obtained. The CPNs exhibit good electrochemical performance as the anode material in lithium-ion batteries (LIBs). This approach expands the frontiers of CPN synthesis and provides new opportunities to their scalable applications.

Perovskite Oxide-Halide Solid Solutions: A Platform for Electrocatalysts.

The successful integration or hybridization of perovskite oxides with their halide cousins would enable the formation of both multi-anionic and multi-cationic solid solutions with unique metal-ion sites and synergistic properties that could potentially surpass the performance of classic perovskites. However, such solid solutions had not been produced previously owing to their distinct formation energies and different synthesis conditions. Solid solutions combining perovskite oxides with fluorides were produced in this study by mechanochemical synthesis. The obtained perovskite oxide-halide solid solutions had highly mixed elements and valences, uniform element distributions, and single-phase crystalline structures. The solid solution with an optimized combination of oxides and fluorides exhibited enhanced catalytic performance in the oxygen evolution reaction.

Ambient Temperature Graphitization Based on Mechanochemical Synthesis.

Graphite has become a critical material because of its high supply risk and essential applications in energy industries. Its present synthesis still relies on an energy-intensive thermal treatment pathway (Acheson process) at about 3000 °C. Herein, a mechanochemical approach is demonstrated to afford highly crystalline graphite nanosheets at ambient temperature. The key to the success of our methodology lies in the successive decomposition and rearrangement of a carbon nitride framework driven by a denitriding reaction in the presence of magnesium. The afforded graphite features high crystallinity, a high degree of graphitization, a thin nanosheet architecture, and a small flake size, which endow it with superior efficiency in lithium-ion batteries as an anode material in terms of rate capacity and cycle stability. The mild and cost-effective pathway used in this study could be a promising alternative for graphite production.

Cardiovascular magnetic resonance-derived myocardial strain in asymptomatic heart transplanted patients and its correlation with late gadolinium enhancement.

OBJECTIVES: To investigate whether cardiovascular magnetic resonance (CMR)-derived myocardial strains were abnormal in asymptomatic heart transplant (HT) patients with normal left ventricular ejection fraction (LVEF) and to detect the relationship between CMR-derived myocardial strain parameters and late gadolinium enhancement (LGE) in asymptomatic HT patients. METHODS: A total of 72 HT patients and 35 healthy volunteers underwent 1.5-T MR scanning. The examination protocol included basic cine imaging and LGE. The deformation registration algorithm (DRA) and feature tracking (FT) software were used for the strain analyses. Myocardial strain measurements included left ventricular global longitudinal strain (LVGLS), LV global circumferential strain (LVGCS), LV global radial strain (LVGRS) and right ventricular longitudinal strain (RVLS). RESULTS: Compared with healthy volunteers, HT patients had significantly decreased DRA- and FT- derived myocardial strain measurements (all p < 0.05). There was a significant correlation and high reproducibility between the DRA- and FT-derived strain parameters. Both CMR-derived LVGLS and LVGRS were significantly related to the presence of LGE, and multivariate logistic regression analyses showed that the LVGLS measurement obtained from both techniques was independently associated with the presence of LGE. The odds ratios (ORs) for DRA- and FT-LVGLS were 1.340 and 1.342, respectively. CONCLUSIONS: Asymptomatic HT patients with preserved LVEF exhibited reduced myocardial strain parameters. The CMR-derived LVGLS was independently related to the presence of LGE in HT patients. KEY POINTS: • Reduced myocardial strain parameters were found in asymptomatic heart transplanted (HT) patients with normal left ventricular ejection fraction (LVEF). • The deformation registration algorithm (DRA) and feature tracking (FT)-derived strains in asymptomatic HT patients had high reproducibility. • DRA- and FT-derived LVGLS had an independent relationship with late gadolinium enhancement (LGE) in asymptomatic HT patients.

Efficient Nanostructuring of Silicon by Electrochemical Alloying/Dealloying in Molten Salts for Improved Lithium Storage.

Application of nanostructured silicon (nSi) is significantly retarded by challenges in the production of affordable nSi. We herein report a high-yield (ca. 100 %) and low-energy (2 kWh Kg-nSi-1 ) nanostructuring of industrial microsized silicon (mSi) through a closed-loop electrochemical Mg alloying/dealloying in molten MgCl2 /NaCl/KCl at 773 K. The resulting nSi unexpectedly shows a salt-unwetted character, allowing an automatic separation from the melts. Thus water washing and accompanying oxidation of the nSi can be avoided. The final product has a nanoporous structure and comprises Si nanorods (ca. 30 nm in diameter) with an ultrathin oxide coating. It can be used for Li storage giving a combination of high initial coulombic efficiency, high specific capacity, and long cycling stability. This nanostructuring process consumes very few chemicals except for the mSi and produces almost zero waste.

CMR-derived extracellular volume fraction (ECV) in asymptomatic heart transplant recipients: correlations with clinical features and myocardial edema.

Myocardial interstitial expansion seems to be fundamental to the process of adverse left ventricular remodeling. Recent evidence has shown that the extracellular volume fraction (ECV) derived from cardiovascular magnetic resonance (CMR) can be used as a noninvasive method to quantify myocardial interstitial volume in a range of heart diseases. Our aim was to determine whether ECV is increased in asymptomatic orthotopic heart transplant (HTx) patients and its associations with clinical features and T2 values, the elevation of which usually suggests myocardial edema. A group of asymptomatic cardiac transplant recipients and some healthy volunteers were invited to undergo a comprehensive CMR scan, including cine imaging, late gadolinium enhancement, T1 mapping and T2 mapping, from March to June in 2017. All quantitative measurements were averaged from the basal and mid short-axis slices. Fifty-eight recipients (mean age, 42.7 ± 11.5 years; 13 females), at a median of 1.8 years (0.3-6.3 years) after HTx, and 20 healthy volunteers (mean age, 39.5 ± 11.3 years; 5 females) underwent the CMR scan. We found that both the ECV and T2 values were higher in the post-HTx group (ECV: 26.7 ± 3.3 vs. 24.6 ± 2.5%, p = 0.008; T2: 47.7 ± 2.8 vs. 44.5 ± 1.6 ms, p < 0.001) than in the control group. ECV was moderately associated with organ ischemia time at the time of transplantation but not with the hemodynamics parameter or the time since transplantation at CMR. Additionally, a relatively strong correlation was observed between ECV and T2 (r = 0.7, p < 0.001). So, our conclusion is that CMR-derived ECV is increased and associated with peri-transplant ischemia time in asymptomatic HTx patients. And the strong correlation of ECV with elevated T2 indicates that myocardial edema may be an important part of the extracellular volume expansion after heart transplantation.

Association between myocardial extracellular volume and strain analysis through cardiovascular magnetic resonance with histological myocardial fibrosis in patients awaiting heart transplantation.

BACKGROUND: Cardiovascular magnetic resonance (CMR)-derived extracellular volume (ECV) and tissue tracking strain analyses are proposed as non-invasive methods for quantifying myocardial fibrosis and deformation. This study sought (1) to histologically validate myocardial ECV against the collagen volume fraction (CVF) measured from tissue samples of patients undergoing heart transplantation and (2) to detect the correlations between myocardial systolic strain and the myocardial ECV and histological CVF in patients undergoing heart transplantation. METHODS: A total of 12 dilated cardiomyopathy (DCM) and 10 ischaemic cardiomyopathy (ICM) patients underwent T1 mapping with the Modified Look Locker Inversion recovery (MOLLI) sequence, T2 mapping and ECV. Myocardial systolic strain, including left ventricular global longitudinal (GLS), circumferential (GCS) and radial strain (GRS), were quantified using CMR cine images with tissue tracking analysis software. Tissue samples were collected from each of 16 segments of the explanted hearts and were stained with picrosirius red for histological CVF quantification. RESULTS: A strong relationship was observed between the global myocardial ECV and histological CVF in the DCM and ICM patients based on a per-patient analysis (r = 0.904 and r = 0.901, respectively, p <  0.001). In the linear mixed-effects regression analysis, ECV correlated well with the histological CVF in the DCM and ICM patients on a per-segment basis (ß = 0.838 and ß = 0.915, respectively, p <  0.001). In the multivariate linear regression analysis, histological CVF was the strongest independent determinant of ECV in the patients awaiting heart transplantation (standardised ß = 0.860, p <  0.001). However, the T2 time, GLS, GCS and GRS showed no significant associations with ECV and CVF in the patients awaiting heart transplantation. CONCLUSIONS: ECV derived from CMR correlated well with histological CVF, indicating its potential as a non-invasive tool for the quantification of myocardial fibrosis. Additionally, impaired myocardial systolic strains were not associated with the ECV and CVF in the patients awaiting heart transplantation.

Electrolysis of metal oxides in MgCl2 based molten salts with an inert graphite anode.

Electrolysis of solid metal oxides has been demonstrated in MgCl2-NaCl-KCl melt at 700 °C taking the electrolysis of Ta2O5 as an example. Both the cathodic and anodic processes have been investigated using cyclic voltammetry, and potentiostatic and constant voltage electrolysis, with the cathodic products analysed by XRD and SEM and the anodic products by GC. Fast electrolysis of Ta2O5 against a graphite anode has been realized at a cell voltage of 2 V, or a total overpotential of about 400 mV. The energy consumption was about 1 kW h kgTa(-1) with a nearly 100% Ta recovery. The cathodic product was nanometer Ta powder with sizes of about 50 nm. The main anodic product was Cl2 gas, together with about 1 mol% O2 gas and trace amounts of CO. The graphite anode was found to be an excellent inert anode. These results promise an environmentally-friendly and energy efficient method for metal extraction by electrolysis of metal oxides in MgCl2 based molten salts.

Phylogenetic studies of two Anas platyrhynchos (Anatini: Anatinae) in Hunan province of China based on complete mitochondrial DNA sequences.

In this study, we cloned and sequenced the complete mitochondrial DNAs of Chinese duck, Anas platyrhynchos, population from two different areas of Hunan province in China. The Anas platyrhynchos breed Linwu duck (LW) sample was taken from the Linwu county of Chenzhou city, and the Anas platyrhynchos breed Youxian duck (YX) sample was taken from the Youxian county of Zhuzhou city. The lengths of their complete mitochondrial genome were 16,604 bp (LW) and 16,606 bp (YX), respectively. The organization of the two Anas platyrhynchos breed mitochondrial genomes was similar to those reported from other duck mitochondrial genomes. Phylogenetic analyses using N-J computational algorithms showed that the analyzed species are divided into four major clades: Anatinae, Anserinae, Dendrocygninae and Anseranatidae. Also, the Linwu duck and Youxian duck have highly similar phylogenetic relationship.

Efficacy of positive airway pressure on brain natriuretic peptide in patients with heart failure and sleep-disorder breathing: a meta-analysis of randomized controlled trials.

OBJECTIVE: Positive airway pressure (PAP) has been recognized as an effective therapeutic option for sleep-disordered breathing (SDB) in patients with heart failure (HF), and it can improve left ventricular function. Whether PAP can ameliorate serum brain natriuretic peptide (BNP) levels, a biomarker of HF, is controversial. The purpose of the present study was to quantitatively assess the efficacy of PAP on BNP in patients with HF and SDB. METHODS: A systematic search of PubMed, Embase, Web of Science and Cochrane library identified six randomized controlled trials (RCTs), in which PAP was compared with medical therapy, subtherapeutic PAP or different types of PAP. The data of BNP were extracted and pooled into meta-analysis using STATA 12.0. RESULTS: Totally 6 RCT studies (7 cohorts) with 222 patients were enrolled into analysis. The quality of each study was high and the heterogeneity (I(2) = 58.1%) was noted between studies. A significant reduction of BNP was observed after PAP treatment in patients with HF and SDB (SMD -0.517, 95% CI -0.764 to -0.270, z = 4.11, p = 0.000). CONCLUSION: Our meta-analysis of RCTs demonstrated that PAP elicits significant reduction of BNP in patients with HF and SDB.