Search

The aim of the study was to develop a model of coronary microembolization (CME) in rats at a lower cost. We developed a novel rat model without thoracotomy and ventilation under the guidance of echocardiography. Rats were sacrificed at 3 h, 24 h and 1 month postoperatively in both the Echo-CME and Open-chest CME groups for the comparison of the modeling accuracy, mortality, cardiopulmonary circulation, pleural adhesion and ventilation-induced lung injury (VILI). Results showed that the coronary microthrombus formed at 3 h and reached its peak at 24 h postoperatively, which included platelet aggregation and fibrin web. The Echo-group increases success rates, decreased mortality, postoperative complications including pleural adhesion, cardiopulmonary dysfunction and VILI postoperatively than the Open-chest group at 1month postoperatively. The ejection fraction of the CME group decreased to 50% and obvious cardiac fibrosis formed at 3 months postoperatively. Our unique surgical method provided a platform to study molecular mechanisms and potential new pathways for CME treatment.

Background: The coronary microvascular dysfunction has attracted more and more attention in recent years, but there is still a lack of effective treatment. Shexiang Baoxin Pill is one of the commonly used drugs for the treatment of coronary artery disease in China. More recently, some studies found that it has the effect of improving coronary microvascular function.Objective: To evaluate the effects of Shexiang Baoxin Pill for coronary microvascular function.Methods: Databases including MEDLINE, Web of Science, CNKI, Wanfang, The Cochrane Library, EMbase, VIP and CBM were searched from inception to June 2021 to screen out relevant clinical studies. The 2019 version 2 of the Cochrane risk of bias tool (RoB2) were used to assess the methodological quality of the included studies. RevMan 5.3 software was used for meta-analysis.Results: Eleven studies meeting the criteria were included, with a total of 1,075 patients. The results of meta-analysis showed that compared with conventional treatment alone, combination of Shexiang Baoxin Pill and conventional treatment can further increase the coronary flow reserve (CFR) [mean difference (MD) = 0.43, 95%CI (0.28, 0.58), p < 0.000 01], decrease the index of microvascular resistance (IMR) [MD = −4.23, 95%CI (−5.49, −2.97), p < 0.000 01], increase serum nitric oxide (NO) [MD = 11.96, 95%CI (2.74, 21.18), p = 0.001] and decrease serum hypersensitive C-reactive protein (hs-CRP) [MD = −2.49, 95%CI (−3.08, −1.90), p < 0.000 01], but did not increase the time of duration on the exercise testing (TET) [MD = 3.64, 95%CI (−1.17, 8.45), p = 0.14]. In terms of safety, a total of 10 patients developed adverse reactions in the intervention group and 17 patients developed adverse reactions in the control group.Conclusion: Current evidence suggests that Shexiang Baoxin Pill may be effective in the improvement of coronary microvascular function when used in combination with conventional treatment. However, due to the low quality of the included studies, lack of placebo control and high heterogeneity among different studies, we should take a cautious attitude towards this conclusion. Moreover, the safety of Shexiang Baoxin Pill remains uncertain, more high-quality clinical studies are needed to verify the efficacy and safety of this drug in the future.Systematic Review Registration: [website], identifier [registration number: CRD42021265113].

Ferroptosis is a form of cell death induced by excess iron and accumulation of reactive oxygen species in cells. Recently, ferroptosis has been reported to be associated with cancer and ischemia/reperfusion (I/R) injury in multiple organs. However, the regulatory effects and underlying mechanisms of myocardial I/R injury are not well-understood. The role of miR-135b-3p as an oncogene that accelerates tumor development has been confirmed; however, its role in myocardial I/R is not fully understood. In this study, we established an in vivo myocardial I/R rat model and an in vitro hypoxia/reoxygenation (H/R)-induced H9C2 cardiomyocyte injury model and observed that ferroptosis occurred in tissues and cells during I/R myocardial injury. We used database analysis to find miR-135b-3p and validated its inhibitory effect on the ferroptosis-related gene glutathione peroxidase 4 (Gpx4), using a luciferase reporter assay. Furthermore, miR-135b-3p was found to promote the myocardial I/R injury by downregulating GPX4 expression. The results of this study elucidate a novel function of miR-135b-3p in exacerbating cardiomyocyte ferroptosis, providing a new therapeutic target for improving I/R injury.

Background: The number of heart failure with preserved ejection fraction (HFpEF) patients is increasing year by year, yet all western medicines currently used for heart failure have been shown to be ineffective for HFpEF. Qishen Yiqi Dripping Pill is one of the commonly drugs for the treatment of heart failure in China. In recent years, some clinical studies found that it has curative effect on HFpEF.Objective: To evaluate the efficacy and safety of Qishen Yiqi Dripping Pill in treatment of HFpEF.Methods: Databases including CNKI, Wanfang, VIP, CBM, PubMed, Web of Science, The Cochrane Library and EMbase were searched from their inception to May 2020 to screen relevant randomized controlled trials. The “risk of bias” evaluation tool in the Cochrane Handbook was used to evaluate the quality of the included studies. RevMan 5.3 software was used for meta-analysis.Results: Eight studies meeting the criteria were included, with a total of 895 patients. The results of meta-analysis showed that compared with western medicine alone, combination of western medicine and Qishen Yiqi Dripping Pill can further increase the quotient of early diastolic mitral inflow velocity and late diastolic mitral inflow velocity (E/A) in patients with HFpEF [mean difference (MD) = 0.20, 95% CI (0.14, 0.26), p < 0.000 01], decrease the quotient of early diastolic mitral inflow velocity and mitral annular tissue velocity (E/e′) [MD = −2.50, 95% CI (−3.18, −1.82), p < 0.000 01], decrease brain natriuretic peptide (BNP) [MD = −151.83, 95% CI (−245.78, −57.89), p = 0.002], increase cardiac function improvement rate [relative risk (RR) = 1.30, 95% CI (1.11, 1.52), p = 0.001], and increase six-minutes walking distance (6-MWD) [MD = 64.75, 95% CI (22.65, 106.85), p = 0.003]. Four studies reported the occurrence of adverse reactions, among which three studies reported no adverse reactions and one study reported three patients with mild adverse reactions in the intervention group.Conclusion: Current evidence suggests that Qishen Yiqi Dripping Pill may be effective in the treatment of HFpEF. However, due to the low quality of the included studies, lack of placebo control, large heterogeneity among different studies, and great possibility of publication bias, the results of our review should be evaluated with more prudence, more high-quality clinical studies are needed to verify the conclusion in the future. In addition, the safety of Qishen Yiqi Dripping Pill remains uncertain, further assessment is required in the future.

Waste management is a major source of global greenhouse gas (GHG) emissions and many opportunities exist to reduce these emissions. To identify the GHG emissions from waste management in China, the characteristics of MSW and the current and future treatment management strategies, five typical management scenarios were modeled by EaseTech software following the principles of life cycle inventory and analyzed based on the carbon and energy flows. Due to the high organic fraction (50–70%) and moisture content (>50%) of Chinese municipal solid waste (MSW), the net GHG emissions in waste management had a significant difference from the developed countries. It was found that the poor landfill gas (LFG) collection efficiency and low carbon storage resulted landfilling with flaring and landfilling with biogas recovery scenarios were the largest GHG emissions (192 and 117 kgCO2-Eq/t, respectively). In contrast, incineration had the best energy recovery rate (19%), and, by grid emissions substitution, led to a substantial decrease in net GHG emissions (−124 kgCO2-Eq/t). Due to the high energy consumption in operation, the unavoidable leakage of CH4 and N2O in treatment, and the further release of CH4 in disposing of the digested residue or composted product, the scenarios with biological treatment of the organic fractions after sorting, such as composting or anaerobic digestion (AD), did not lead to the outstanding GHG reductions (emissions of 32 and −36 kgCO2-Eq/t, respectively) as expected.

Aims and methods Acute myocardial infarction (AMI) is a common cardiovascular disease with high mortality. Astragaloside IV (AS-IV) was reported to have cardioprotective effect after AMI. We hypothesize that the cardioprotective role of AS-IV is exerted by enhancing angiogenesis via regulating PTEN/PI3K/Akt signaling pathway. To valid our hypothesis, AMI rats and human umbilical vein endothelial cells (HUVECs) were employed in our study. Key findings After treatment, cardiac function, survival rate, infarct size, pathological changes and fibrosis, cell apoptosis, ultrastructural changes, angiogenesis and expression of PTEN/PI3K/Akt signaling pathway were evaluated, respectively. In vitro study we detected proliferation, tube formation and signaling pathway activation of HUVECs treated with AS-IV, lentivirus overexpressed PTEN was employed to elucidate the potential mechanism. The results indicated that AS-IV administration significantly improved cardiac function and survival rate, limited infarct size, ameliorated pathological changes and fibrosis deposition, inhibited apoptosis, relieved ultrastructure injury and enhanced angiogenesis, PTEN/PI3K/Akt signaling pathway was activated simultaneously compared to the model group. In vitro study suggested that AS-IV treatment promoted cell proliferation and tube formation, and induced PTEN/PI3K/Akt signaling pathway activation. Importantly, overexpression of PTEN by lentivirus abolished AS-IV-induced angiogenesis. Significance Our study indicated that AS-IV could promote angiogenesis and cardioprotection after myocardial infarction. The mechanisms involve activation of PTEN/PI3K/Akt signaling pathway.

Shaking table model tests were carried out to study the seismic behaviors of double box utility tunnel with joint connections and the surrounding soil. The seismic wave obtained from 1952 Taft earthquake was employed as the input in this study, and its PGA has been adjusted to 0.2 g, 0.4 g, 0.8 g, and 1.2 g, respectively. In addition, a series of sine waves with PGA of 0.2 g and frequencies of 5 Hz, 10 Hz, 15 Hz, 20 Hz, 25 Hz, and 30 Hz were applied to study the effect of frequency characteristics on seismic behavior of the utility tunnel and the surrounding soil. The testing results show that the laminar soil container does not impose significant boundary effect, and the dynamic earth pressure response is significantly influenced due to existence of the joint connection. Besides, the effect of soil-structure interaction on seismic behaviors is becoming even more obvious as the input PGA increases. The acceleration response is also significantly influenced by the dynamic property of the soil. Greater bending moment occurs at the corners of the structure, and its increasing ratio will decrease with an increasing input PGA magnitude. Lastly, the effect of frequency is significant. Therefore, it is noteworthy that the possible effect of natural frequency is considered when the utility tunnel is under construction.

By establishing the mathematical model of the current stress of the isolated bidirectional dc-dc converter (IBDC), this paper comparatively analyzes the performances of IBDC under traditional single-phase-shift control and dual-phase-shift (DPS) control. On this basis, this paper proposes a current-stress-optimized switching strategy for IBDC with DPS control, and the corresponding control scheme is designed and implemented. The current-stress-optimized switching strategy can minimize the current stress, improve the system efficiency, and increase system power capability, and these performances are particularly effective for operation conditions with high voltage conversion ratio and light load. At last, experimental results verify the excellent performance of the current-stress-optimized switching strategy and correctness of the theoretical analysis.

This paper points out a phenomenon of power backflow in traditional phase-shift (TPS) control of isolated bidirectional full-bridge DC-DC converter (IBDC), and analyzes the effects which backflow power act on power circulating flow and current stress. On this basis, the paper proposes a novel extended-phase-shift (EPS) control of IBDC for power distribution in microgrid. Compared with TPS control, EPS control not only expands regulating range of transmission power and enhances regulating flexibility, but also reduces current stress and improves the system efficiency. The operation principle of EPS control and the operation modes of IBDC are analyzed in the paper. By establishing mathematical models of transmission power, backflow power, and current stress, the paper comparatively analyzes control performances of TPS and EPS control. At last, experimental results verify the excellent performance of EPS control and correctness of the theoretical analysis.

High on-aspirin platelet reactivity (HAPR) has been associated with compromised aspirin efficacy in patients with diabetes suffering from acute cardiovascular events, but the key mechanisms remain elusive. The objective of this study was to uncover the potential link between pathogenic accumulation of salicylic acid (SA), the major metabolite of aspirin, and HAPR in diabetic state. Aspirin failed to inhibit platelet CD62P expression and thromboxane (TX) B2/6-keto-prostaglandin（PG）F1α ratio in a type 2 diabetes mellitus (T2DM) mice model, particularly in the female, which were unanimously accompanied by significantly higher plasma SA concentrations. Pre-administration with SA increased both platelet CD62P expression and TXB2/6-keto-PGF1α ratio in female T2DM mice, while pretreatment with NaHCO3 caused the opposite effect. On the in vitro human umbilical vein endothelial cells (HUVECs)-platelet interaction assay, SA suppressed inflammation-induced cyclooxygenase-2 upregulation on HUVECs and attenuated their inhibitory effect on platelet aggregation in a dose-dependent manner. The prolonged retention of SA in diabetes may be partially explained by the downregulation of various SA efflux transporters in the kidney and the decreased urine pH. Importantly, in female aspirin non-responsive patients, the trough plasma concentration of SA are markedly increased with T2DM treated with long-term aspirin, and TXB2/6-keto-PGF1α ratio and uric acid level in plasma are positively correlated with SA concentration. Our findings support that the accumulation of SA represents an important factor in causing HAPR in diabetes, and that targeting impaired SA excretion may become a novel intervention strategy to diabetes-associated HAPR.

Migraine is a primary headache disorder characterized by recurrent attacks of throbbing pain associated with neurological, gastrointestinal and autonomic symptoms. Previous studies have detected structural deficits and functional impairments in migraine patients. However, researchers have failed to investigate the functional connectivity alterations of regions with structural deficits during the resting state. Twenty-one migraine patients without aura and 21 age-and gender-matched healthy controls participated in our study. Voxel-based morphometric (VBM) analysis and functional connectivity were employed to investigate the abnormal structural and resting-state properties, respectively, in migraine patients without aura. Relative to healthy comparison subjects, migraine patients showed significantly decreased gray matter volume in five brain regions: the left medial prefrontal cortex (MPFC), dorsal anterior cingulate cortex (dACC), right occipital lobe, cerebellum and brainstem. The gray matter volume of the dACC was correlated with the duration of disease in migraine patients, and thus we chose this region as the seeding area for resting-state analysis. We found that migraine patients showed increased functional connectivity between several regions and the left dACC, i.e. the bilateral middle temporal lobe, orbitofrontal cortex (OFC) and left dorsolateral prefrontal cortex (DLPFC). Furthermore, the functional connectivity between the dACC and two regions (i.e. DLPFC and OFC) was correlated with the duration of disease in migraine patients. We suggest that frequent nociceptive input has modified the structural and functional patterns of the frontal cortex, and these changes may explain the functional impairments in migraine patients. Copyright (C) 2012 John Wiley & Sons, Ltd.

Photoplethysmography (PPG) is an optical method for detecting blood volume changes in tissue. Respiratory-induced intensity, frequency and amplitude variations are contained in the PPG signal; thus, an understanding of the relationships between all of these variations and respiration is essential to advancing respiration monitoring based on PPG. This study investigated correlations between respiratory-induced variations extracted from PPG and simultaneous respiratory signals. PPG signals were recorded from 28 healthy subjects under eight different conditions. Six respiratory-induced variations, i.e. the period of the systole, diastole and pulse, the amplitude of the systole and diastole, and the intensity variation, were determined from the PPG signal. The results indicate that, compared with the period of the pulse, the period of the systole and diastole correlates weakly with respiration; the amplitude of the diastole has a stronger correlation with respiration than the amplitude of the systole. For men, when the respiratory rate is less than 10 breaths min(-1), the period of the pulse has the strongest correlation with respiration, whereas up to or above 15 breaths min(-1), the intensity variation becomes strongest in the sitting posture, while the amplitude of the diastole is strongest in the supine posture. For women, compared with the other variations, the period of the pulse has nearly the strongest correlation with respiration, independent of respiratory rate or posture.

To solve the network performance deterioration caused by network nodes failure according to unexpected and unforeseen environmental changes in wireless sensor network WSN, a high fault-tolerant and energy-efficient multipath routing protocol based on the idea of hybrid, energy-efficient distributed HEED clustering protocol, called HEED fault tolerant HEED-FT is proposed in this paper. To improve the routing reliability and energy balance between cluster heads, the HEED-FT algorithm first introduces the non-probability waiting time, residue energy and centres to improve the cluster lifetime. Then multiple clustering parameters are applied with different hierarchy which can control the ideal topology distribution of the cluster heads. Finally, a multiple trees Gabriel graph MTGG model is put forward to get a reliable communication link with multiple clustering parameters which can ensure the nodes in an ideal cluster topology distribution. The simulation results show that HEED-FT has less energy consumption, higher reliability and longer network survival than the traditional algorithms.

Along with the increasing system capacity, large-scaled energy storage systems are supposed to be connected into 10kV or higher networks. Urban network has strict criterions on power quality of the power electronic devices connected. Moreover, the occupancy and noise of industrial frequency transformers also become restraints to the promotion of urban network energy storage. For that reason, this paper proposes a battery energy storage system based on cascaded dc-ac converter, dual active bridges, and a common dc bus. High frequency transformers are used to replace the industrial frequency transformer for insulation, and battery groups are connected to the common dc bus with respective dc-dc interfaces. This multilevel converter system is easy to modularize, easy to extend, and allows different kinds of batteries to work together. The main circuit and proper control system are designed, with the soft-switching condition and current control issues of the dual active bridge analyzed in detail. The simulation results from EMTDC model verify the operation principles and corresponding control strategies.

An approach using morphological filter technique is proposed to determine the respiratory rhythm from the photoplethysmographic (PPG) signal. As the structuring elements of morphological filter have a decisive effect on the analysis result, in the study the structuring elements are determined by the individual heart rate adaptively. The procedure was tested on a group of healthy subjects. Compared with the reference respiratory signal from the transthoracic impedance measurement, the proposed method is an efficient tool to detect the respiratory rhythm from PPG signal. Furthermore, the low computational complexity of the algorithm may make it easy to be implemented on Microprogrammed Control Units (MCU) for real-time processing. More experimental data is necessary to improve the reliability and robustness of the algorithm.