Green Vehicle-Routing Problem of Fresh Agricultural Products Considering Carbon Emission.

The need to reduce carbon emission to cope with climate change has gradually become a global consensus, which also poses a great challenge to cold-chain logistics companies. It forces them to implement green distribution strategies. To help the distribution companies reduce carbon emission, this paper studies two aspects-carbon tax value and investing in the freshness-keeping cost-and proposes corresponding solutions. A new green vehicle-routing model for fresh agricultural products with the goal of minimizing the total cost is proposed. To solve the model proposed, an improved ant-colony optimization (IACO) is designed specifically. On one hand, the experimental results show that the increase in carbon tax will restrict the carbon emission behaviors of the distribution companies, but it will also reduce their economic benefits to a certain extent, at the same time. On the other hand, investing in the freshness-keeping cost can help actively achieve the carbon emission reduction target, reduce the loss of fresh agricultural products in the distribution process, improve the company's economic benefits and satisfy customers. The comparison results of different algorithms prove that the IACO proposed in this paper is more effective in solving the model, which can help increase the economic benefits of the companies and reduce carbon emission. This study provides a new solution for cold-chain logistics distribution companies to reduce carbon emission in the distribution process, and also provides a reference for government departments to formulate carbon tax policies.

Diagnosing Lemierre's Syndrome as the Cause of Multifocal Pneumonia During the COVID-19 Pandemic.

A 21-year-old male with no past medical history presented with a sore throat, cough, and shortness of breath after attending a party days earlier. He was initially treated for community-acquired pneumonia, but subsequently developed a new oxygen requirement. CT imaging of the chest showed multifocal airspace disease, concerning for COVID-19. Testing for SARS-CoV-2 was negative by RT-PCR and antibody testing. Blood cultures subsequently grew Streptococcus anginosus. A CT scan of his neck demonstrated a right peritonsillar abscess and right internal-jugular thrombus, consistent with Lemierre's syndrome. He underwent incision and drainage of the peritonsillar abscess and completed 4 weeks of IV antibiotics, which improved his symptoms. It is important to recognize that the differential diagnosis of multifocal pneumonia is broad and includes Lemierre's syndrome. The COVID-19 pandemic presents challenges with regards to anchoring bias for multifocal pneumonia.

Impaired myocardium energetics associated with the risk for new-onset atrial fibrillation after isolated coronary artery bypass graft surgery.

BACKGROUND: New-onset postoperative atrial fibrillation (POAF) is one of the most common complications occurring in 10-40% of patients after coronary artery bypass graft (CABG) surgery. Recent studies suggest that dysmetabolism may contribute to the pathogenesis of atrial fibrillation; however, the putative mechanism in patients undergoing CABG surgery is unknown. Peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) has been demonstrated as a master regulator of myocardial energy metabolism, and glucose transporter 3 (GLUT3) has both a higher affinity for glucose and a much greater transport capacity compared with GLUT1, GLUT2, and GLUT4. We sought to evaluate the role of energy metabolism, especially the glucose metabolism, on patients after isolated CABG surgery. METHODS AND RESULTS: Right atrial appendages were obtained from 79 patients who were in normal sinus rhythm and undergoing isolated CABG; those who exhibited new-onset POAF (n=22) or remained in sinus rhythm (n=57) were prospectively matched on the basis of preoperative, intraoperative, and postoperative characteristics. POAF was assessed by electrocardiogram and must have required the initiation of antiarrhythmic therapy or anticoagulation. Local PGC-1α and GLUT3 concentrations were quantified by enzyme-linked immunosorbent assay in tissue homogenates. The comparison of mRNA expression was tested by quantitative real-time PCR. PGC-1α and GLUT3 levels and the related protein mRNA expression were significantly reduced in POAF patients compared with controls (P<0.05). This selective reduction in PGC-1α was associated with the presence of diabetes mellitus (P<0.05). CONCLUSION: Patients who have low PGC-1α and GLUT3 levels are at increased risk for new-onset POAF. The myofibrillar energetic impairment may be important in the pathogenesis of atrial fibrillation.

Small molecule Wnt inhibitors enhance the efficiency of BMP-4-directed cardiac differentiation of human pluripotent stem cells.

Human induced pluripotent stem (iPS) cells potentially provide a unique resource for generating patient-specific cardiomyocytes to study cardiac disease mechanisms and treatments. However, existing approaches to cardiomyocyte production from human iPS cells are inefficient, limiting the application of iPS cells in basic and translational cardiac research. Furthermore, strategies to accurately record changes in iPS cell-derived cardiomyocyte action potential duration (APD) are needed to monitor APD-related cardiac disease and for rapid drug screening. We examined whether modulation of the bone morphogenetic protein 4 (BMP-4) and Wnt/ß-catenin signaling pathways could induce efficient cardiac differentiation of human iPS cells. We found that early treatment of human iPS cells with BMP-4 followed by late treatment with small molecule Wnt inhibitors led to a marked increase in production of cardiomyocytes compared to existing differentiation strategies. Using immunocytochemical staining and real-time intracellular calcium imaging, we showed that these induced cardiomyocytes expressed typical sarcomeric markers, exhibited normal rhythmic Ca(2+) transients, and responded to both ß-adrenergic and electric stimulation. Furthermore, human iPS cell-derived cardiomyocytes demonstrated characteristic changes in action potential duration in response to cardioactive drugs procainamide and verapamil using voltage-sensitive dye-based optical recording. Thus, modulation of the BMP-4 and Wnt signaling pathways in human iPS cells leads to highly efficient production of cardiomyocytes with typical electrophysiological function and pharmacologic responsiveness. The use of human iPS cell-derived cardiomyocytes and the application of calcium- and voltage-sensitive dyes for the direct, rapid measurement of iPS cell-derived cardiomyocyte activity promise to offer attractive platforms for studying cardiac disease mechanisms and therapeutics.

Human ISL1 heart progenitors generate diverse multipotent cardiovascular cell lineages.

The generation and expansion of diverse cardiovascular cell lineages is a critical step during human cardiogenesis, with major implications for congenital heart disease. Unravelling the mechanisms for the diversification of human heart cell lineages has been hampered by the lack of genetic tools to purify early cardiac progenitors and define their developmental potential. Recent studies in the mouse embryo have identified a multipotent cardiac progenitor that contributes to all of the major cell types in the murine heart. In contrast to murine development, human cardiogenesis has a much longer onset of heart cell lineage diversification and expansion, suggesting divergent pathways. Here we identify a diverse set of human fetal ISL1(+) cardiovascular progenitors that give rise to the cardiomyocyte, smooth muscle and endothelial cell lineages. Using two independent transgenic and gene-targeting approaches in human embryonic stem cell lines, we show that purified ISL1(+) primordial progenitors are capable of self-renewal and expansion before differentiation into the three major cell types in the heart. These results lay the foundation for the generation of human model systems for cardiovascular disease and novel approaches for human regenerative cardiovascular medicine.

Intramyocardial injection of tannic acid attenuates postinfarction remodeling: a novel approach to stabilize the breaking extracellular matrix.

OBJECTIVE: Myocardial infarction is associated with early matrix metalloproteinase activation and extracellular matrix degradation. We tested the hypothesis that stabilizing the original extracellular matrix of the infarcted left ventricle with local injection of tannic acid would preserve cardiac structure and function. METHODS: In vitro cytotoxicity of tannic acid was performed first; myocardial infarction model was induced by ligation of the left anterior descending branch in rats. Tannic acid was intramyocardially injected into infarcted site 24 hours after myocardial infarction (n = 30), and saline solution was injected in the same way as in the control (n = 30). The matrix metalloproteinase activity from tannic acid/saline solution-treated tissues was assayed by gelatin zymography 24 hours and 1 week after the treatment. The collagen content in the infarcted area was evaluated by hydroxyproline colorimetry assay 1 and 4 weeks after the treatment. Left ventricular structure and function were also evaluated with echocardiography, hemodynamics, and histologic examination. RESULTS: Tannic acid at a concentration of 0.05% had minimal cytotoxic effects on cultured cardiomyocytes and thus was subsequently chosen as the optimal concentration for injection. Compared with the saline solution injection group, tannic acid treatment inhibited the matrix metalloproteinase-2/-9 activity and increased the collagen content at the early post-myocardial infarction stage (48.6 +/- 7.2 vs 37.3 +/- 6 microg/mg dry weight). Tannic acid treatment also significantly reduced infarct expansion (infarct expansion index: 1.04 +/- 0.15 vs 1.42 +/- 0.21) and left ventricular dilatation at 4 weeks after infarction. Although tannic acid treatment improved fractional shortening (26% +/- 2.4% vs 23.3% +/- 3.2%), it failed to alter blood pressure (systolic blood pressure: 93.8 +/- 8.2 vs 90.6 +/- 8.5 mm Hg) and rate of pressure rise. CONCLUSIONS: Local delivery of tannic acid prevents collagen matrix degradation via cross-linking fibrous collagen and inhibiting matrix metalloproteinase activity but does not improve the intrinsic contractile function of myocardium. This treatment may be helpful to attenuate the adverse topographic remodeling after acute myocardial infarction.

Tissue extracts from infarcted myocardium of rats in promoting the differentiation of bone marrow stromal cells into cardiomyocyte-like cells.

OBJECTIVE: To investigate whether cardiac tissue extracts from rats could mimic the cardiac microenvironment and act as a natural inducer in promoting the differentiation of bone marrow stromal cells (BMSCs) into cardiomyocytes. METHODS: Three kinds of tissue extract or cell lysate [infarcted myocardial tissue extract (IMTE), normal myocardial tissue extract (NMTE) and cultured neonatal myocardial lysate (NML)] were employed to induce BMSCs into cardiomyocyte-like cells. The cells were harvested at each time point for reverse transcription-polymerase chain reaction (RT-PCR) detection, immunocytochemical analysis, and transmission electron microscopy. RESULTS: After a 7-day induction, BMSCs were enlarged and polygonal in morphology. Myofilaments, striated sarcomeres, Z-lines, and more mitochondia were observed under transmission electron microscope. Elevated expression levels of cardiac-specific genes and proteins were also confirmed by RT-PCR and immunocytochemistry. Moreover, IMTE showed a greater capacity of differentiating BMSCs into cardiomyocyte-like cells. CONCLUSIONS: Cardiac tissue extracts, especially IMTE, can effectively differentiate BMSCs into cardiomyocyte-like cells.