scholarly journals Cs2Bi2Sr(P2O7)(PO4)2:Er3+/Yb3+ phosphors for outstanding thermal enhancement of up-conversion under 980 and 1550 nm laser excitations in the 303 to 723 K range

2022 ◽  
Vol 10 ◽  
pp. 100242
Author(s):  
Hongqiang Cui ◽  
Yongze Cao ◽  
Lei Li ◽  
Guojian Li ◽  
Yuhang Zhang ◽  
...  
Keyword(s):  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Adriana M. De Mendoza ◽  
Soňa Michlíková ◽  
Johann Berger ◽  
Jens Karschau ◽  
Leoni A. Kunz-Schughart ◽  
...  

AbstractRadiotherapy can effectively kill malignant cells, but the doses required to cure cancer patients may inflict severe collateral damage to adjacent healthy tissues. Recent technological advances in the clinical application has revitalized hyperthermia treatment (HT) as an option to improve radiotherapy (RT) outcomes. Understanding the synergistic effect of simultaneous thermoradiotherapy via mathematical modelling is essential for treatment planning. We here propose a theoretical model in which the thermal enhancement ratio (TER) relates to the cell fraction being radiosensitised by the infliction of sublethal damage through HT. Further damage finally kills the cell or abrogates its proliferative capacity in a non-reversible process. We suggest the TER to be proportional to the energy invested in the sensitisation, which is modelled as a simple rate process. Assuming protein denaturation as the main driver of HT-induced sublethal damage and considering the temperature dependence of the heat capacity of cellular proteins, the sensitisation rates were found to depend exponentially on temperature; in agreement with previous empirical observations. Our findings point towards an improved definition of thermal dose in concordance with the thermodynamics of protein denaturation. Our predictions well reproduce experimental in vitro and in vivo data, explaining the thermal modulation of cellular radioresponse for simultaneous thermoradiotherapy.


2014 ◽  
Vol 89 (6) ◽  
Author(s):  
L. S. Brizhik ◽  
A. A. Eremko ◽  
B. M. A. G. Piette ◽  
W. J. Zakrzewski

2006 ◽  
Vol 58 (6) ◽  
pp. 719-724 ◽  
Author(s):  
Faheez Mohamed ◽  
O. Anthony Stuart ◽  
Olivier Glehen ◽  
Muneyasu Urano ◽  
Paul H. Sugarbaker

2021 ◽  
Vol 108 (Supplement_2) ◽  
Author(s):  
P Prakash Narayan ◽  
R Dutta

Abstract Introduction HIPEC is highly concentrated, heated chemotherapy treatment that is delivered directly to the abdomen during surgery. HIPEC delivers chemotherapy directly to cancer cells in abdomen. Cytoreductive surgery(CRS) combined with perioperative intraperitoneal chemotherapy is currently a valid treatment option for peritoneal dissemination of gastrointestinal, gynaecological cancers or primary peritoneal neoplasms. Method 3 patients with peritoneal surface malignancy were selected. PET scan was done for all the patients to assess metastasis and peritoneal carcinomatosis index(PCI) calculated was<20 for all 3 patients They were then treated with CRS+HIPEC therapy with disease-specific chemotherapeutic agents like Cisplatin, Mitomycin and Doxorubicin and Oxaliplatin . Aim was Results All the 3 patients had a good post-operative recovery with no recurrence in the follow-up period Conclusions HIPEC and CRS plays synergistic role. A complete CRS followed by HIPEC with the disease-specific chemotherapeutic agent at 41-43ºC constitutes optimal treatment for certain malignancies. High regional concentration with low systemic concentration of chemotherapy, increased tissue penetration and thermal enhancement of cytotoxicity are some of the advantages with HIPEC therapy


2014 ◽  
Vol 136 (2) ◽  
Author(s):  
Matthew R. DeWitt ◽  
Allison M. Pekkanen ◽  
John Robertson ◽  
Christopher G. Rylander ◽  
Marissa Nichole Rylander

Single-walled carbon nanohorns (SWNHs) have significant potential for use in photothermal therapies due to their capability to absorb near infrared light and deposit heat. Additionally, their extensive relative surface area and volume makes them ideal drug delivery vehicles. Novel multimodal treatments are envisioned in which laser excitation can be utilized in combination with chemotherapeutic-SWNH conjugates to thermally enhance the therapeutic efficacy of the transported drug. Although mild hyperthermia (41–43 °C) has been shown to increase cellular uptake of drugs such as cisplatin (CDDP) leading to thermal enhancement, studies on the effects of hyperthermia on cisplatin loaded nanoparticles are currently limited. After using a carbodiimide chemical reaction to attach CDDP to the exterior surface of SWNHs and nitric acid to incorporate CDDP in the interior volume, we determined the effects of mild hyperthermia on the efficacy of the CDDP-SWNH conjugates. Rat bladder transitional carcinoma cells were exposed to free CDDP or one of two CDDP-SWNH conjugates in vitro at 37 °C and 42 °C with the half maximal inhibitory concentration (IC50) for each treatment. The in vitro results demonstrate that unlike free CDDP, CDDP-SWNH conjugates do not exhibit thermal enhancement at 42 °C. An increase in viability of 16% and 7% was measured when cells were exposed at 42 deg compared to 37 deg for the surface attached and volume loaded CDDP-SWNH conjugates, respectively. Flow cytometry and confocal microscopy showed a decreased uptake of CDDP-SWNH conjugates at 42 °C compared to 37 °C, revealing the importance of nanoparticle uptake on the CDDP-SWNH conjugate's efficacy, particularly when hyperthermia is used as an adjuvant, and demonstrates the effect of particle size on uptake during mild hyperthermia. The uptake and drug release studies elucidated the difference in viability seen in the drug efficacy studies at different temperatures. We speculate that the disparity in thermal enhancement efficacy observed for free drug compared to the drug SWNH conjugates is due to their intrinsic size differences and, therefore, their mode of cellular uptake: diffusion or endocytosis. These experiments indicate the importance of tuning properties of nanoparticle-drug conjugates to maximize cellular uptake to ensure thermal enhancement in nanoparticle mediated photothermal-chemotherapy treatments.


Author(s):  
Sandip Saha ◽  
Pankaj Biswas ◽  
Apurba Narayan Das

In presence of baffle, the turbulent airflow phenomena as well as forced convective heat exchange characteristics in two-dimensional rectangular channel have been analyzed in this work. For variations in Reynolds number (Re), we have studied the variations in characteristics of thermal behavior due to the change in the shape of baffle. Computations have been done using finite volume method (FVM) and FLUENT software and the SIMPLE algorithm has been employed for solving the governing equations. Finally, the flow and thermal exchange characteristics viz., streamline flow, turbulence intensity (TE), axial velocity, turbulence kinetic energy (TKE), normalized friction factor (F), normalized average Nusselt number (Nuavg) and thermal enhancement factor (TEF) have been studied in details from numerical standpoint. It has been found that the triangular shaped baffle provides highest value of F at Re = 30,000 and at Re = 46, 000, the maximum value of the TEF is found for the same baffle implying that triangular shaped baffle is more suitable for overall purposes.


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