151 research outputs found
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Cryopreservation: Methods, equipment and critical concerns
The technique of cryopreservation aims to maintain the biological samples in a metabolic suspension state, by which all chemical, physical and biological changes are diminished. The biology principles behind cryopreservation are widely investigated in the literature. However, little scientific interest has been focused to the current equipment used as cryogenic storages and how they affect the viability and functionality of the cells during their preservation. This review paper attempts to bridge the gap between the biology and engineering aspects of cryopreservation. The basic principles of cryobiology, the cryoinjury mechanisms, the role of cryoprotective agents, the state of the art cryopreservation methods and equipment, and concerns regarding the use of liquid nitrogen as cryogenic refrigerant are covered. Further to our knowledge there is no complete review in the literature describing the connection between the current cryogenic equipment and the physical events taking place during cryopreservation. The paper aims to provide researchers with the key knowledge of cryopreservation, not only from a biological point of view, but from a technical aspect, too, in order to contribute to the development of the cryobiology field.This work was funded by Air Products PLC
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Experimental and CFD Validation of the Thermal Performance of a Cryogenic Batch Freezer with the Effect of Loading
Cryogenic freezing systems are used in many industries to preserve food and cell cultures. The freezing methods adopted involve multiple systems to preserve cultures, with many freezing systems using a selection of direct freezing and long-term storage allowing mass and time-efficient freezing methods. However, risks associated with direct freezing using liquid nitrogen can cause cell degradation and crystallisation. This study will focus on the implementation of a batch freezer, using liquid nitrogen sprays to freeze products. The effectiveness of the freezing process will be investigated experimentally for an array of operating conditions. Using numerical methods, additional loading configurations and operation temperatures were also studied to characterise the freezing profile of the system
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CFD model of a lab scale cryogenic batch freezer with the investigation of varying effects on the heat transfer coefficient
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The Evolving Role of Cryosurgery in Breast Cancer Management: A Comprehensive Review
Copyright © 2023 by the authors. Breast cancer is the most commonly diagnosed type of cancer, accounting for approximately one in eight cancer diagnoses worldwide. In 2020, there were approximately 2.3 million new cases of breast cancer globally, resulting in around 685,000 deaths. Consequently, there is an ongoing need to develop innovative therapeutic approaches that can improve both clinical outcomes and patient quality of life. The use of ultra-low cryogenic temperatures, facilitated by cryogenic media such as liquid nitrogen, has revolutionized the biomedical field and opened up new possibilities for advanced clinical treatments, including cryosurgery. Cryosurgery has demonstrated its feasibility as a minimally invasive technique for destroying breast tumors and eliciting a significant antitumor immune response in the host. This feature sets cryosurgery apart from other ablative techniques. It has been shown to be well tolerated and effective, offering several advantages such as simplicity, the avoidance of general anesthesia, minimal pain, low morbidity, short recovery time, cost-effectiveness, and notably, improved aesthetic outcomes. The reviewed studies indicate that cryosurgery holds promise in the management of early-stage breast cancer and metastatic disease, especially in triple-negative and Her2-positive molecular subtypes in conjunction with checkpoint inhibitors and anti-Her2 antibodies, respectively. Furthermore, the effectiveness of cryosurgery in the management of ductal carcinoma in situ should be investigated as an alternative modality to surgery or surveillance. The minimally invasive nature of cryosurgery has the potential to significantly enhance the quality of life for patients.Air Products PLC under grant agreement: 216-206-P-F
Preclinical evaluation of cyclin dependent kinase 11 and casein kinase 2 survival kinases as RNA interference targets for triple negative breast cancer therapy
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Low-temperature heat transfer mediums for cryogenic applications
Copyright © 2023 The Author(s). Background:
Researchers and industrialists have grown interested in cryogenic technologies over the years. Cryogenic heat transfer has enabled new applications due to material properties and behaviour at very low temperatures. This domain is still underdeveloped and unfamiliar in various applications.
Methods:
This work discusses the recent progress on cryogenic mediums and their respective use in different heat transfer applications. After identifying what is commonly designated as a cryogenic medium, i.e., those with a boiling point below -150 °C, the different characteristics and features of such mediums are critically discussed.
Significant findings:
Liquid He and N2 were found to be the most used cryogenic mediums, mainly due to the very low temperature attained by liquid He, as the closest to the absolute zero, along with the low cost and high availability of liquid N2. The use of liquid-phase cryogenic in a single-phase state was found to be the most common application method. Two-phase applications of the cryogenic medium are mainly for use in a heat pipe, in which both latent and sensible heat is utilized. Cryogenic mediums are essential for critical and niche applications such as in aerospace, superconductivity, advanced machining and manufacturing methods, and more critically in many healthcare applications and advanced scientific research.Air Products PLC under grant agreement: 216-206-P-F
Identification and functional characterisation of CRK12:CYC9, a novel cyclin-dependent kinase (CDK)-cyclin complex in Trypanosoma brucei
The protozoan parasite, Trypanosoma brucei, is spread by the tsetse fly and causes trypanosomiasis in humans and animals. Both the life cycle and cell cycle of the parasite are complex. Trypanosomes have eleven cdc2-related kinases (CRKs) and ten cyclins, an unusually large number for a single celled organism. To date, relatively little is known about the function of many of the CRKs and cyclins, and only CRK3 has previously been shown to be cyclin-dependent in vivo. Here we report the identification of a previously uncharacterised CRK:cyclin complex between CRK12 and the putative transcriptional cyclin, CYC9. CRK12:CYC9 interact to form an active protein kinase complex in procyclic and bloodstream T. brucei. Both CRK12 and CYC9 are essential for the proliferation of bloodstream trypanosomes in vitro, and we show that CRK12 is also essential for survival of T. brucei in a mouse model, providing genetic validation of CRK12:CYC9 as a novel drug target for trypanosomiasis. Further, functional characterisation of CRK12 and CYC9 using RNA interference reveals roles for these proteins in endocytosis and cytokinesis, respectively
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