1,721,010 research outputs found
Experimental study of mitigation systems to prevent Thermal Runaway of Li-ion Batteries
Full text linkLi-ion batteries have experienced a widespread deployment due to the strong interest in electrochemical devices capable of storing a large amount of energy in small volumes and supplying high powers when required. However, besides those advantages, this technology still presents several unsolved issues, especially regarding the safety aspects. These devices can, in fact, experience thermal runaway if the generated thermal power is not adequately dispersed, and this can occur when the cell / battery is subjected to abuse conditions (mechanical, electrical or thermal abuses). The experimental study was carried out using a full-scale hardware simulator, capable of simulating the thermal behavior of a battery pack, where electrically heated elements replaced real Li-ion cells. This expedient guarantees a high reproducibility of the working conditions and consequently a higher reliability of the measured data. The hardware simulator allows to reproduce the thermal behavior under normal operating conditions, and under abuse conditions which can lead to thermal runaway. The present work reports the results of the tests that have been carried out by reproducing the abuse conditions in one cell inside a battery module; the abused cell is heated with a high power (from 100 to 500 W for cells with a maximum heat loss of 30 W under normal operating conditions) and the efficiency of different cooling systems is checked both in limiting the temperature of the abused cell and in preventing the propagation of heat to the adjacent cells. In particular, different fluids, different fluid speeds and different mitigation methods have been tested
Temperature control of Lithium-ion battery packs under high- current abuse conditions
No full textLi-ion batteries are being widely used as power sources in a continuously increasing number of applications (from portable devices to electric vehicles and even more complex systems). Nonetheless these components are still characterized by serious concerns connected with their safety and stability, which often hinder their more widespread use. In particular, their operation is strictly dependent on their temperature which derives from the balance between the heat internally produced during operation and that dissipated towards the external environment. Beyond certain temperatures a thermal runaway can occur with possible dangerous events, such as fires and explosions. In the present paper, 3D simulations have been carried out to investigate the cooling efficiency of an air flow, under different operating conditions, on a cylindrical Li-ion cell located in a whole battery pack. Under the investigated configurations, it was found that, beyond a minimum value of the passing air velocity, it is possible to keep the cell within safe conditions, thus preventing a thermal runaway
The RANKL-RANK axis: A bone to thymus round trip
No full textThe identification of Receptor activator of nuclear factor kappa B ligand (RANKL) and its cognate receptor Receptor activator of nuclear factor kappa B (RANK) during a search for novel tumor necrosis factor receptor (TNFR) superfamily members has dramatically changed the scenario of bone biology by providing the functional and biochemical proof that RANKL signaling via RANK is the master factor for osteoclastogenesis. In parallel, two independent studies reported the identification of mouse RANKL on activated T cells and of a ligand for osteoprotegerin on a murine bone marrow-derived stromal cell line. After these seminal findings, accumulating data indicated RANKL and RANK not only as essential players for the development and activation of osteoclasts, but also for the correct differentiation of medullary thymic epithelial cells (mTECs) that act as mediators of the central tolerance process by which self-reactive T cells are eliminated while regulatory T cells are generated. In light of the RANKL-RANK multi-task function, an antibody targeting this pathway, denosumab, is now commonly used in the therapy of bone loss diseases including chronic inflammatory bone disorders and osteolytic bone metastases; furthermore, preclinical data support the therapeutic application of denosumab in the framework of a broader spectrum of tumors. Here, we discuss advances in cellular and molecular mechanisms elicited by RANKL-RANK pathway in the bone and thymus, and the extent to which its inhibition or augmentation can be translated in the clinical arena
Advances in cancer therapy: Novel approaches in combined drug treatments
No full textDrug resistance and poor efficacy of anticancer therapies prompt to investigate innovative therapeutic strategies aimed to improving efficacy and lowering toxicity. Recent advances in chemotherapeutics have been achieved using specific pharmaceutical combinations or ameliorating drug delivery by drug encapsulation. Novel combined treatments are based on the use of drugs, typically natural active or intended for other uses combined with the classical anti-cancer drug. These compounds promote synergistic effects even more enhanced when drug delivery is achieved by nanocarriers. Nanotechnologies provide a site-specific delivery at the tumor site, resulting from receptor-mediated endocytosis and prolonged circulation time. Nanocarriers also increase drug bioavailability and biocompatibility contributing to a drug increase inside the tumor and determining a minor toxicity and a better efficacy. This chapter reports recent findings about novel anticancer combined treatments and about the latest drug delivery systems based on the use of nanocarriers
Combined anticancer therapies: An overview of the latest applications
No full textTumor resistance and low drug efficacy prompt to investigate new therapeutic strategies that have high efficacy and low toxicity, especially for cancers with poor prognosis. This goal has been recently achieved using particular pharmaceutical combination or nanotechnologies to specifically deliver drugs at the tumor site. Novel combined treatments employ either naturally active ingredients or drugs already intended for other uses, with the aim to increase cell sensitivity to therapy and reduce drug toxicity. Combined treatments usually improve the overall therapeutic efficacy of the single drug. Drug–drug interactions allow synergistic effects. Several evidences indicate that synergy can be affected by drug–drug ratio and drug administration order. Therapeutic efficacy can be enhanced through drug entrapment in nanocarriers that allow a site-specific targeting, resulting in a build-up of the drug in the tumor with a significant toxicity reduction. Several studies investigated combined entrapment of two or more drugs each one characterized by different mechanisms of action. These nanosystems improve synergistic efficacy and could be a device to resolve toxicity and multi-drug resistance. Nano-encapsulation of anticancer agents by targeting specific tumor tissues significantly optimizes drug bioavailability, biocompatibility and therapeutic efficacy. The efficacy of these formulations results from receptor-mediated endocytosis and prolonged circulation time. Drug encapsulation also allows using limited final concentration while avoiding its activity within the blood circulation. In this review we report recent findings about novel combined treatment focusing on synergistic effects and mechanisms of action. We will also overview the latest drug delivery system and their therapeutic benefits in cancer treatment
Editorial: The bone/bone marrow microenvironment: A hub for immune regulation of the tumor cells fate
Full text linkA simplified model for improving thermal stability of Lithium-ion batteries
Full text linkLithium ion batteries represent a well established technology in a range of applications (laptops, mobile phones, etc.) but they are becoming key factors in many other areas were reliability and safety are of paramount importance (e.g. the space and automobile industries). However, a number of drawbacks still raise concerns about their wider use and hamper a more structured introduction in these additional applications. In particular, the management of heat effects remains a challenge, as an excessive temperature rise can cause reduction of cycle life, battery failures and, above all, may lead to thermal runaway of individual cells or of an entire battery pack, with associated damages to the surrounding people or environment. In the present paper, a simplified model capable of predicting the thermal behaviour of a battery pack refrigerated with a cooling fluid, is presented. It allows to quickly estimating the efficiency of a given cooling system under specific working conditions, and thus identify the range of operation within which a given energy storage system can safely operate
Thermal management of lithium-ion batteries: An experimental investigation
No full textThis paper describes a set of experimental tests carried out to better understand the thermal behavior of Lithium-ion batteries under load and the capability of various cooling fluids in maintaining the working conditions within a safe range for the cells. Despite several theoretical models are available in the literature, very few experimental data are reported. Different types of cells have been analyzed. The generation of hot spots has sometimes been registered, their occurrence being independent of cell geometry and size; instead, the battery's history and age, appeared the main factors in determining the onset of hot spots on the surface of the cell. Two experimental rigs have been set up to test the capability of different cooling fluids in removing the surplus heat generated in a Li-ion battery module, where the cells of interest have been replaced with electrically heated elements with the same thermal characteristics of the cells. It was thus possible to safely investigate “extreme” operating conditions, where the occurrence of a thermal runaway is possible. Among the tested fluids, air was unable to adequately limit the surface temperature increase, while a perfluorinated polyether, allowed to work within the optimal temperature range, even under severe operating conditions
Genetics of Osteopetrosis
No full textPurpose of Review: The term osteopetrosis refers to a group of rare skeletal diseases sharing the hallmark of a generalized increase in bone density owing to a defect in bone resorption. Osteopetrosis is clinically and genetically heterogeneous, and a precise molecular classification is relevant for prognosis and treatment. Here, we review recent data on the pathogenesis of this disorder. Recent Findings: Novel mutations in known genes as well as defects in new genes have been recently reported, further expanding the spectrum of molecular defects leading to osteopetrosis. Summary: Exploitation of next-generation sequencing tools is ever spreading, facilitating differential diagnosis. Some complex phenotypes in which osteopetrosis is accompanied by additional clinical features have received a molecular classification, also involving new genes. Moreover, novel types of mutations have been recognized, which for their nature or genomic location are at high risk being neglected. Yet, the causative mutation is unknown in some patients, indicating that the genetics of osteopetrosis still deserves intense research efforts
Soluble factors on stage to direct mesenchymal stem cells fate
No full textMesenchymal stem cells (MSCs) are multipotent stromal cells that are identified by in vitro plastic adherence, colony-forming capacity, expression of a panel of surface molecules, and ability to differentiate at least toward osteogenic, adipogenic, and chondrogenic lineages. They also produce trophic factors with immunomodulatory, proangiogenic, and antiapoptotic functions influencing the behavior of neighboring cells. On the other hand, a reciprocal regulation takes place; in fact, MSCs can be isolated from several tissues, and depending on the original microenvironment and the range of stimuli received from there, they can display differences in their essential characteristics. Here, we focus mainly on the bone tissue and how soluble factors, such as growth factors, cytokines, and hormones, present in this microenvironment can orchestrate bone marrow-derived MSCs fate. We also briefly describe the alteration of MSCs behavior in pathological settings such as hematological cancer, bone metastasis, and bone marrow failure syndromes. Overall, the possibility to modulate MSCs plasticity makes them an attractive tool for diverse applications of tissue regeneration in cell therapy. Therefore, the comprehensive understanding of the microenvironment characteristics and components better suited to obtain a specific MSCs response can be extremely useful for clinical use
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