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Deep-sea equipment is generally made of lightweight and pressure-resistant materials in order to meet the requirements of the actual work. In order to explore marine resources better, it is necessary to research lightweight buoyancy materials for loading on mining equipment. These buoyancy materials contribute not only to providing adequate buoyancy to the mining equipment but also to reducing economic expenses. In this paper, hollow glass microspheres reinforced epoxy hollow spheres (HGMSs-EHSs) were prepared by the rolling ball method using expanded polystyrene (EPS), epoxy resin (EP), and HGMS as raw materials. Epoxy syntactic foam (ESF) was manufactured by blending EP, curing agent, HGMS, and HGMS-EHS with molding method. Basalt fiber (BF) reinforced ESF was fabricated by adding BFs to form a fiber network inside the syntactic foam. The results revealed that the density and compressive strength of ESF increased progressively with the number of HGMS-EHS layers. The density and compressive strength of ESF decreased prospectively with the increase of the stacking volume fraction of HGMS-EHS. The density and compressive strength of ESF increased gradually with the enlargement of the length and content of BF. In the range of influencing factors mentioned above, the density of ESF remains around 0.3 g/cm3, which has a low density. When the number of layers of HGMS-EHS was two, the stacking volume fraction was 90%, the length of BF was 12 mm, the content of BF was 4%, the density of BF-ESF was 0.316 g/cm3, and the compressive strength was 6.93 MPa. The compressive strength of prepared buoyancy material can meet the pressure resistance requirements for operations in waters of a certain depth. With a density of only 0.316 g/cm3, it provides sufficient buoyancy to balance the gravity of the equipment. Compared with the current study, in this paper, BFs were used as the reinforcing phase to prepare solid buoyancy foam with low density and high compressive strength. The experimental results demonstrate that this economical fiber material can effectively improve the compressive strength of buoyancy materials. This buoyancy material may be suitable for loading on small equipment for extracting marine resources. This work provides a reference for the preparation of low-density solid buoyancy materials.

Background: We investigate whether deep learning (DL) neural networks can reduce erroneous human “judgment calls” on bedside echocardiograms and help distinguish Takotsubo syndrome (TTS) from anterior wall ST segment elevation myocardial infarction (STEMI). Methods: We developed a single-channel (DCNN[2D SCI]), a multi-channel (DCNN[2D MCI]), and a 3-dimensional (DCNN[2D+t]) deep convolution neural network, and a recurrent neural network (RNN) based on 17,280 still-frame images and 540 videos from 2-dimensional echocardiograms in 10 years (1 January 2008 to 1 January 2018) retrospective cohort in University of Iowa (UI) and eight other medical centers. Echocardiograms from 450 UI patients were randomly divided into training and testing sets for internal training, testing, and model construction. Echocardiograms of 90 patients from the other medical centers were used for external validation to evaluate the model generalizability. A total of 49 board-certified human readers performed human-side classification on the same echocardiography dataset to compare the diagnostic performance and help data visualization. Findings: The DCNN (2D SCI), DCNN (2D MCI), DCNN(2D+t), and RNN models established based on UI dataset for TTS versus STEMI prediction showed mean diagnostic accuracy 73%, 75%, 80%, and 75% respectively, and mean diagnostic accuracy of 74%, 74%, 77%, and 73%, respectively, on the external validation. DCNN(2D+t) (area under the curve [AUC] 0·787 vs. 0·699, P = 0·015) and RNN models (AUC 0·774 vs. 0·699, P = 0·033) outperformed human readers in differentiating TTS and STEMI by reducing human erroneous judgement calls on TTS. Interpretation: Spatio-temporal hybrid DL neural networks reduce erroneous human “judgement calls” in distinguishing TTS from anterior wall STEMI based on bedside echocardiographic videos. Funding: University of Iowa Obermann Center for Advanced Studies Interdisciplinary Research Grant, and Institute for Clinical and Translational Science Grant. National Institutes of Health Award (1R01EB025018–01).

Background Acute myocardial infarction (AMI) with in‐hospital onset (AMI‐IHO) has poor prognosis but is clinically underappreciated. Whether its occurrence has changed over time is uncertain. Methods and Results Since 1987, the ARIC (Atherosclerosis Risk in Communities) study has conducted adjudicated surveillance of AMI hospitalizations in 4 US communities. Our analysis was limited to patients aged 35 to 74 years with symptomatic AMI. Patients with symptoms initiating after hospital arrival were considered AMI‐IHO. A total of 26 678 weighted hospitalizations (14 276 unweighted hospitalizations) for symptomatic AMI were identified from 1995 to 2014, with 1137 (4%) classified as in‐hospital onset. The population incidence rate of AMI‐IHO increased in the 4 ARIC communities from 1995 through 2004 to 2005 through 2014 (12.7—16.9 events per 100 000 people; P for 20‐year trend 65.

Abstract Effective removal or dissolution of large blood clots remains a challenge in clinical treatment of acute thrombo-occlusive diseases. Here we report the development of an intravascular microbubble-mediated sonothrombolysis device for improving thrombolytic rate and thus minimizing the required dose of thrombolytic drugs. We hypothesize that a sub-megahertz, forward-looking ultrasound transducer with an integrated microbubble injection tube is more advantageous for efficient thrombolysis by enhancing cavitation-induced microstreaming than the conventional high-frequency, side-looking, catheter-mounted transducers. We developed custom miniaturized transducers and demonstrated that these transducers are able to generate sufficient pressure to induce cavitation of lipid-shelled microbubble contrast agents. Our technology demonstrates a thrombolysis rate of 0.7 ± 0.15 percent mass loss/min in vitro without any use of thrombolytic drugs.

As a well-known medical imaging methodology, intravascular ultrasound (IVUS) imaging plays a critical role in diagnosis, treatment guidance and post-treatment assessment of coronary artery diseases. By cannulating a miniature ultrasound transducer mounted catheter into an artery, the vessel lumen opening, vessel wall morphology and other associated blood and vessel properties can be precisely assessed in IVUS imaging. Ultrasound transducer, as the key component of an IVUS system, is critical in determining the IVUS imaging performance. In recent years, a wide range of achievements in ultrasound transducers have been reported for IVUS imaging applications. Herein, a comprehensive review is given on recent advances in ultrasound transducers for IVUS imaging. Firstly, a fundamental understanding of IVUS imaging principle, evaluation parameters and IVUS catheter are summarized. Secondly, three different types of ultrasound transducers (piezoelectric ultrasound transducer, piezoelectric micromachined ultrasound transducer and capacitive micromachined ultrasound transducer) for IVUS imaging are presented. Particularly, the recent advances in piezoelectric ultrasound transducer for IVUS imaging are extensively examined according to their different working mechanisms, configurations and materials adopted. Thirdly, IVUS-based multimodality intravascular imaging of atherosclerotic plaque is discussed. Finally, summary and perspectives on the future studies are highlighted for IVUS imaging applications.

Hyperphosphatemia, the elevated level of inorganic phosphate (Pi) in serum, is associated with increased cardiovascular morbidities and mortality. The effects of high Pi on endothelial cells are not well studied. This study investigated high Pi-induced endothelial cell apoptosis and the role of microRNA-21. Mouse myocardial endothelial cells (MEC) were cultured in normal (1 mM) and high (5 mM) Pi conditions. Apoptosis was detected by TUNEL staining and flow cytometry. MicroRNA profiles of MEC response to changes in Pi concentration were obtained using gene expression arrays. Expression levels of the microRNA-21 target genes, programmed cell death gene 4 ( PDCD4), poly(ADP-ribose) polymerase ( PARP), and phosphatase and tensin homolog ( PTEN), as well as NF-κB were measured by Western blotting and RT-PCR. MicroRNA-21-specific inhibitors and mimics were used to study effects of microRNA-21 on MEC apoptosis and gene expression regulations. High Pi induced MEC apoptosis and upregulated microRNA-21 expression. MicroRNA-21-specific mimics reproduced high Pi-induced apoptosis in normal Pi medium, and microRNA-21 inhibitors ameliorated the high Pi induction of apoptosis, suggesting that microRNA-21 mediated high Pi-induced MEC apoptosis. The microRNA-21 targets PDCD4, PTEN, PARP, and NF-κB were significantly downregulated in high Pi conditions. High Pi-induced downregulation of PDCD4 was abolished by microRNA-21 inhibitors and selective ERK inhibitor (selumetinib) and was reproduced by microRNA-21 mimics. Inhibitors and mimics of microRNA-21 did not have effects on high Pi-induced NF-κB downregulation. Selumetinib blocked high Pi-induced NF-κB downregulation. MicroRNA-21 mediates high Pi-induced endothelial cell apoptosis, which involves an ERK1/2/microRNA-21/PDCD4 pathway. High Pi-induced downregulation of NF-κB expression is mediated by an ERK1/2 signaling-dependent but microRNA-21-independent mechanism. [ABSTRACT FROM AUTHOR]

ST-segment elevation myocardial infarction (STEMI) is most commonly caused by an acute thrombotic occlusion of a coronary artery. For patients in whom the onset of STEMI occurs outside of hospital (outpatient STEMI), early reperfusion therapy with either fibrinolysis or primary percutaneous coronary intervention reduces complications and improves survival, compared with delayed reperfusion. STEMI systems of care are defined as integrated groups of separate entities focused on reperfusion therapy for STEMI, generally including emergency medical services, emergency medicine, cardiology, nursing, and hospital administration. These systems of care have been successful at reducing total ischaemia time and outpatient STEMI mortality. By contrast, much less is known about STEMI that occurs in hospitalized patients (inpatient STEMI), which has unique clinical features and much worse outcomes than outpatient STEMI. Inpatient STEMI is associated with older age, a higher female:male ratio, and more comorbidities than outpatient STEMI. Delays in diagnosis and infrequent use of reperfusion therapy probably also contribute to unfavourable outcomes for inpatient STEMI. [ABSTRACT FROM AUTHOR]

Thrombotic thrombocytopenic purpura (TTP) affects essentially all organ systems. Myocardial injury in TTP is often attributed to microthrombi formation. We present the first case report in the literature of an acute TTP patient with concomitant obstructive coronary artery disease (CAD) and acute myocardial infarction who underwent successful percutaneous coronary intervention (PCI). A 70-year-old female patient who was diagnosed with acute TTP required plasma exchange. The patient also experienced episodes of angina pectoris, elevated cardiac enzymes and global ST segment depressions on ECG. A subsequent non-invasive ischaemia workup revealed significant ischaemia. Coronary angiography revealed obstructive CAD in her right coronary artery, requiring PCI with a bare metal stent placement and dual antiplatelet therapy. The patient tolerated antiplatelet therapy well. At 6 months of follow-up, she had no recurrent angina. This case highlights the potential co-existence of obstructive CAD and acute TTP requiring careful differential diagnosis and treatment. [ABSTRACT FROM AUTHOR]

IMPORTANCE Reperfusion times for ST-elevation myocardial infarction (STEMI) occurring in outpatients have improved significantly, but quality improvement efforts have largely ignored STEMI occurring in hospitalized patients (inpatient-onset STEMI). OBJECTIVE To define the incidence and variables associated with treatment and outcomes of patients who develop STEMI during hospitalization for conditions other than acute coronary syndromes (ACS). DESIGN, SETTING, AND PARTICIPANTS Retrospective observational analysis of STEMIs occurring between 2008 and 2011 as identified in the California State Inpatient Database. EXPOSURES STEMIs were classified as inpatient onset or outpatient onset based on present-on-admission codes. Patients who had a STEMI after being hospitalized for ACS were excluded from the analysis. MAIN OUTCOMES AND MEASURES Regression models were used to evaluate associations among location of onset of STEMI, resource utilization, and outcomes. Adjustments were made for patient age, sex, comorbidities, and hospital characteristics. The analysis allowed for the location of inpatient STEMI to have a multiplicative rather than an additive effect for resource utilization since these measures were highly skewed. RESULTS A total of 62 021 STEMIs were identified in 303 hospitals, of which 3068 (4.9%) occurred in patients hospitalized for non-ACS indications. Patients with inpatient-onset STEMI were older (mean, 71.5 [SD, 13.5] years vs 64.9 [SD, 14.1] years; P < .001) and more frequently female (47.4%vs 32%; P < .001) than those with outpatient-onset STEMI. Patients with inpatient-onset STEMI had higher in-hospital mortality (33.6%vs 9.2%; adjusted odds ratio (AOR), 3.05; 95%CI, 2.76-3.38; P < .001), were less likely to be discharged home (33.7% vs 69.4%; AOR, 0.38; 95%CI, 0.34-0.42; P < .001), and were less likely to undergo cardiac catheterization (33.8% vs 77.8%; AOR, 0.19; 95%CI, 0.16-0.21; P < .001) or percutaneous coronary intervention (21.6%vs 65%; AOR, 0.23; 95%CI, 0.21-0.26; P < .001). Length of stay and inpatient charges were higher for inpatient-onset STEMI (mean length of stay, 13.4 days [95%CI, 12.8-14.0 days] vs 4.7 days [95%CI, 4.6-4.8 days]; adjusted multiplicative effect, 2.51; 95%CI, 2.35-2.69; P < .001; mean inpatient charges, $245 000 [95%CI, $235 300-$254 800] vs $129 000 [95%CI, $127 900-$130 100]; adjusted multiplicative effect, 2.09; 95%CI, 1.93-2.28; P < .001). [ABSTRACT FROM AUTHOR]

The article attempts to identify candidate loci responsible for genetic-dependent variation in collateral circulation. The authors reported that four quantitative trait loci (QTL) were derived for collateral number, including epistasis between two loci. They were also able to map a QTL that was identical with the strongest QTL for chromosome 7 collateral number. They concluded that collateral extent and remodeling are heritable complex traits.

The article presents a study which investigated the role of endothelial nitric oxide synthase (eNOS) in forming native collaterals and remodeling in obstructive disease by comparing the native collateral circulation in healthy tissue and collateral remodeling after femoral artery ligation (FAL) in wild-type and eNOS-knockedout (KO) mice. The results showed that perfusion after FAL fell in adult eNOS-KOs due to collateral loss during growth to adulthood. eNOS-KOs also has reduced collateral remodeling and angiogenesis as compared to wild-types.

Proteins responsible for Pi homeostasis are critical for all life. In Saccharomyces cerevisiae, extracellular [Pi] is "sensed" by the inositol-hexakisphosphate kinase (IP6K) that synthesizes the intracellular inositol pyrophosphate 5-diphosphoinositol 1,2,3,4,6-pentakisphosphate (5-InsP7) as follows: during a period of Pi starvation, there is a decline in cellular [ATP]; the unusually low affinity of IP6Ks for ATP compels 5-InsP7 levels to fall in parallel (Azevedo, C., and Saiardi, A. (2017) Trends. Biochem. Sci. 42, 219-231. Hitherto, such Pi sensing has not been documented in metazoans. Here, using a human intestinal epithelial cell line (HCT116), we show that levels of both 5-InsP7 and ATP decrease upon [Pi] starvation and subsequently recover during Pi replenishment. However, a separate inositol pyrophosphate, 1,5-bisdiphosphoinositol 2,3,4,6-tetrakisphosphate (InsP8), reacts more dramatically (i.e. with a wider dynamic range and greater sensitivity). To understand this novel InsP8 response, we characterized kinetic properties of the bifunctional 5-InsP7 kinase/InsP8 phosphatase activities of full-length diphosphoinositol pentakisphosphate kinases (PPIP5Ks). These data fulfil previously published criteria for any bifunctional kinase/phosphatase to exhibit concentration robustness, permitting levels of the kinase product (InsP8 in this case) to fluctuate independently of varying precursor (i.e. 5-InsP7) pool size. Moreover, we report that InsP8 phosphatase activities of PPIP5Ks are strongly inhibited by Pi (40-90% within the 0-1 mM range). For PPIP5K2, Pi sensing by InsP8 is amplified by a 2-fold activation of 5-InsP7 kinase activity by Pi within the 0-5 mM range. Overall, our data reveal mechanisms that can contribute to specificity in inositol pyrophosphate signaling regulating InsP8 turnover independently of 5-InsP7, in response to fluctuations in extracellular supply of a key nutrient. [ABSTRACT FROM AUTHOR]