RESUMEN

Many challenges have emerged due to the intense integration of renewables in the distribution system and the associated uncertainties in power generation. Consequently, local management strategies are developed at the distribution level, leading to the emergence of concepts such as microgrids. Microgrids include a variety of heating, cooling, and electrical resources and loads, and the operators' aim is to minimize operation and outage costs. Since significant distribution system outages are typically caused by events such as earthquakes, floods, and hurricanes, microgrid operators are compelled to improve resilience to ensure uninterrupted service during such conditions. A mixed-integer linear programming model is designed in this paper to optimize the energy management and structural configuration of microgrids. This optimization aims to enhance resilience cost, minimizing operation and capital costs as well as power loss and pollution. To achieve these goals, several tools are implemented including reconfiguration, storages, combined cooling, heat and power units, wind turbines, photovoltaic panels, as well as capacitors. Four case studies are defined to prove the developed model efficiency. The first case study focuses on energy management in the microgrid for operation cost minimization. The second case study emphasizes the improvement of resilience alongside energy management, aiming at minimizing costs and enhance resilience. In the third case, the microgrid's reconfiguration capability is also added to the second case. Therefore, this case aims to optimize both energy and structural management within the microgrid to simultaneously enhance resilience and minimize operational costs. Finally, in the fourth case, the problem is studied in a multi-objective approach. By comparing the results, the resilience impact on the operation of microgrids is elucidated. By considering the resilience concept in microgrid operation and based on the results of case 2, it is found that the operating costs are increased by an average of 10.38 %. However, because of reducing resilience costs by an average of 13.91 %, the total cost is reduced by an average of 5.93 % in case 2 compared to case 1. Furthermore, when comparing cases 2 and 3, the reconfiguration effect can be determined. It can be observed that the operating costs are decreased by an average of 4.5 %. Moreover, the resilience cost is decreased by an average of 1.61 %, resulting in an overall reduction of the total objective function by an average of 2.43 % in case 3 compared to case 2.

RESUMEN

Development of the multigeneration plants based on the simultaneous production of water and energy can solve many of the current problems of these two major fields. In addition, the integration of fossil power plants with waste heat recovery processes in order to prevent the release of pollutants in the environment can simultaneously cover the environmental and thermodynamic improvements. Besides, the addition of a carbon dioxide (CO2) capturing cycles with such plants is a key issue towards a sustainable environment. Accordingly, a novel waste heat recovery-based multigeneration plant integrated with a carbon dioxide separation/liquefaction cycle is proposed and investigated under multi-variable assessments (energy/exergy, financial, and environmental). The offered multigeneration system is able to generate various beneficial outputs (electricity, liquefied CO2 (L-CO2), natural gas (NG), and freshwater). In the offered system, the liquified natural gas (LNG) cold energy is used to carry out condensation processes, which is a relatively new idea. Based on the results, the outputs rates of net power, NG, L-CO2, and water were determined to be approximately 42.72 MW and 18.01E+03, 612 and 3.56E+03 kmol/h, respectively. Moreover, the multigeneration plant was efficient about 32.08% and 87.72%, respectively, in terms of energy and exergy. Economic estimates indicated that the unit product costs of electricity and liquefied carbon dioxide production, respectively, were around 0.0466 USD per kWh and 0.0728 USD per kg-CO2. Finally, the total released CO2 was about 0.034 kg per kWh. According to a comprehensive comparison, the offered multigeneration plant can provide superior environmental, thermodynamic, and economic performances compared to similar plants. Moreover, there was no need to purchase electricity from the grid.

RESUMEN

Date seeds have been studied for their possible health advantages as they are employed in various traditional remedies. This study aimed to investigate how date affected hematology, renal, and liver function in rabbits before and after date feeding. In total, 30 rabbits were used in this investigation, and they were divided into two groups (n=15). Group one (G1) was considered the control group and received only a meal without dates for 30 days, and group two (G2) was given date seed extract a about 30 ml/kg b.w. for 30 days. The findings revealed that daily oral administration of date extract resulted in a considerable increase in hemoglobin (Hgb) concentration. It is now recognized as a useful source of natural therapeutic ingredients for a variety of ailments. The study results showed that the oral administration of dates led to a significant increase in Hgb concentration, Hgb indices (MCH, MCV, MCHC, PLT, WBCs, and RBCs) and a significant increase in total protein, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, creatinine, and blood urea nitrogen levels (P≤0.05). However, there were no significant changes in albumin in G2, compared to G1. Finally, dates may help to increase biochemical and hematological parameters in rabbits.

Asunto(s)

RESUMEN

Breast cancer is a common cancer and is the leading cause of cancer-related deaths among women worldwide. Studies have shown that breast cancer is a heterogeneous tumor with varying response to treatments. The clinical use of doxorubicin (Dox) in the treatment of cancer is limited by its cardiotoxicity which results in often fatal heart failure and the development of multidrug resistance. Therefore, new therapeutic strategies and targets are underscored. Propolis has been reported to show a broad spectrum of biological activities including anticancer activity. In this study, we investigated the role of propolis on the antitumor effects of Dox on breast cancer cells (MDA-MB-231) and its ability to provide protection against Dox-mediated damage on normal cells (MRC-5). Modifications in cell viability, apoptosis induction, cell cycle progression and permeability glycoprotein (P-gp) activity of breast cancer cells in vitro were evaluated. Propolis combined with Dox inhibited cell growth in a dose dependent manner by inducing cell cycle arrest in the S phase and caspase-dependent apoptosis. In the presence of propolis, the IC50 of Dox against MDA-MB-231 cells decreased by 10-fold. The increased sensitivity of cancer cells to the combined treatment was explained by the capacity of propolis to cause a significant increase in Dox content in MDA-MB-231. Very interestingly, Algerian propolis showed its ability to inhibit efficiently P-gp function in comparison with verapamil, reference P-gp modulator, which proves the efficacy of propolis to reverse the problem of multidrug resistance. Our results showed also that propolis could protect normal cells from deleterious effects of Dox by amelioration of cell viability. In conclusion, the obtained results indicate that Algerian propolis potentiated the antitumor effects of Dox on breast cancer cells and could reduce the problem of multidrug resistance. Therefore, Algerian propolis may be an effective agent in a combined treatment with Dox for increased therapeutic efficacy against breast cancer. Clinically, our results are relevant because with this combined therapy it may be possible to counter the problem of cancer cell resistance while reducing the problem of toxicity on normal cells.

Asunto(s)

RESUMEN

Intravascular imaging has evolved alongside interventional cardiology as an adjunctive tool for assessing plaque pathology and for guiding and optimizing percutaneous coronary intervention (PCI) in challenging lesions. The two modalities which have dominated the field are intravascular ultrasound (IVUS), which relies on sound waves and optical coherence tomography (OCT), relying on light waves. These approaches however have limited efficacy in assessing plaque morphology and vulnerability that are essential for guiding PCI in complex lesions and identifying patient at risk that will benefit from emerging therapies targeting plaque evolution. These limitations are complementary and, in this context, it has been recognized and demonstrated in multi-modality studies that the concurrent use of IVUS and OCT can help overcome these deficits enabling a more complete and accurate plaque assessment. The Conavi Novasight Hybrid IVUS-OCT catheter is the first commercially available device that is capable of invasive clinical coronary assessment with simultaneously acquired and co-registered IVUS and OCT imaging. It represents a significant evolution in the field and is expected to have broad application in clinical practice and research. In this review article we present the limitations of standalone intravascular imaging techniques, summarize the data supporting the value of multimodality imaging in clinical practice and research, describe the Novasight Hybrid IVUS-OCT system and highlight the potential utility of this technology in coronary intervention and in the study of atherosclerosis.

Asunto(s)

RESUMEN

Chronic idiopathic constipation (CIC) can be defined as bowel movements that are difficult to pass, are not occurring frequently, or have incomplete evacuation during defecation. A high-fiber diet and laxatives are the commonly used treatments, but in many cases, they do not produce satisfactory results. The first line of treatment is osmotic laxatives. If there is no improvement, the second line is guanylate cyclase-C (GCC) agonists like linaclotide or prokinetic agents such as prucalopride. On December 14, 2018, the United States Food and Drug Administration (US FDA) approved prucalopride for treating chronic idiopathic constipation. Prucalopride is a prokinetic agent which works at the 5-hydroxytryptamine receptor 4 (5-HT4) as an agonist with greater receptor selectivity. Patients on prucalopride reported improved symptoms, quality of life and satisfaction. The most frequent adverse events were headaches and problems related to the gastrointestinal tract. Caution should be taken when using prucalopride in patients with impaired liver and renal function. In Canada, prucalopride has been approved for treatment of female patients with chronic idiopathic constipation who have failed therapy with at least two laxatives from different classes over a six-month period.

RESUMEN

The worldwide incidence of neuroendocrine tumors (NETs) has been increasing. They are a very diverse group of tumors which are commonly found in the gastrointestinal and bronchopulmonary tracts. These tumors usually express somatostatin receptors. Therefore, somatostatin analogs are used for symptom relief as well as treatment. Of the many therapeutic options available, peptide receptor radionuclide therapy (PRRT) has been shown to be very promising. In January 2018, the Food Drug and Authority (FDA) approved 177Lu-Dotatate for use in gastroenteropancreatic neuroendocrine tumors (GEP-NETs). Lutetium is a lower energy beta-emitting radionuclide. The therapeutic use of lutetium-177 (177Lu) has shown better results in advanced gastroenteropancreatic and bronchial neuroendocrine tumors when compared with other therapies available. Adverse effects associated with this therapy include myelotoxicity and nephrotoxicity as the radiopeptides are reabsorbed and accumulate in the renal interstitium. Everolimus is a good and safe option in patients pretreated with 177Lu-Dotatate. Lutetium, in combination with somatostatin analogs, has proven efficacy to treat gastroenteropancreatic neuroendocrine tumors in candidates with somatostatin receptor-positive advanced tumors and normal renal function. This therapy has great potential as it decreases tumor size, improves symptoms, and improves quality of life.

RESUMEN

A method for linking genomic sequences cloned in yeast artificial chromosomes (YACs) has been tested using Caenorhabditis elegans as a model system. Yeast clones carrying YACs with repeated sequences were selected from a C. elegans genomic library, total DNA was digested with restriction enzymes, transferred to nylon membranes and probed with a variety of repetitive DNA probes. YAC clones that overlap share common bands with one or more repetitive DNA probes. In 159 YAC clones tested with one restriction enzyme and six probes 28 overlapping clones were detected. The advantages and limitations of this method for construction of YAC physical maps is discussed.

Asunto(s)