This study investigates the energy transfer mechanism between the organic polymer poly(2-methoxy-5(2'-ethyl)heroxyphenylenevinylene) (MEH-PPV) and CdSe/ZnS core-shell quantum dots (CdSe/ZnS CSQDs). Additionally, a hybrid ZnO-based photodetector (PD) is fabricated using the composite of MEH-PPV and CdSe/ZnS CSQDs, aiming to gain deeper insights. The combination of MEH-PPV and CdSe/ZnS CSQDs facilitates a broad spectral response in PDs, spanning from the ultraviolet (UV) to the visible range.
View Article and Find Full Text PDFPurpose: To compare plan quality among photon volumetric arc therapy (VMAT), Gamma Knife, and three different proton beam modalities.
Methods: Fifty-five brain lesions from 20 patients were planned with three different proton spot size ranges of cyclotron-generated proton beams, CPBs (spot size σ: 2.7-7.
Microbiology (Reading)
October 2023
Anaerobic bacteria often use antiporters DcuB (malate/succinate antiport) or DcuA (l-aspartate/succinate antiport) for the excretion of succinate during fumarate respiration. The rumen bacterium is able to produce large amounts of succinate by fumarate respiration, using the DcuB-type transporter DcuE for l-malate/succinate antiport. Asuc_0142 was annotated as a second DcuB-type transporter.
View Article and Find Full Text PDFBackground And Purpose: Brain radiotherapy (cnsRT) requires reproducible positioning and immobilization, attained through redundant dedicated imaging studies and a bespoke moulding session to create a thermoplastic mask (T-mask). Innovative approaches may improve the value of care. We prospectively deployed and assessed the performance of a patient-specific 3D-printed mask (3Dp-mask), generated solely from MR imaging, to replicate a reproducible positioning and tolerable immobilization for patients undergoing cnsRT.
View Article and Find Full Text PDFTo evaluate the dosimetric impact of titanium implants in spine SBRT using four dose calculation algorithms. Twenty patients with titanium implants in the spine treated with SBRT without density override (DO) were selected. The clinical plan for each patient was created in Pinnacle and subsequently imported into Eclipse (AAA and AcurosXB) and Raystation (CC) for dose evaluation with and without DO to the titanium implant.
View Article and Find Full Text PDFRadiation-induced cell death is a complex process influenced by physical, chemical and biological phenomena. Although consensus on the nature and the mechanism of the bystander effect were not yet made, the immune process presumably plays an important role in many aspects of the radiotherapy including the bystander effect. A mathematical model of immune response during and after radiation therapy is presented.
View Article and Find Full Text PDFPurpose: Volumetric-modulated arc therapy for total body irradiation (VMAT-TBI) is a novel radiotherapy technique that has been implemented at our institution. The purpose of this work is to investigate possible failure modes (FMs) in the treatment process and to develop a quality control (QC) program for VMAT-TBI following TG-100 guidelines.
Methods: We formed a multidisciplinary team to map out the complete treatment process of VMAT-TBI following the AAPM TG-100 guidelines.
Radiation-induced cell death is a complex process influenced by physical, chemical and biological phenomena. Strong dose gradient may intensify the complexity and reportedly creates significantly more cell death known as bystander effect. Although consensus on the nature and the mechanism of the bystander effect were not yet made, the immune process presumably plays an important role in many aspects of the radiotherapy including the bystander effect.
View Article and Find Full Text PDFAs frameless stereotactic radiosurgery increase in use, the aim of this study was to evaluate intra-fraction motion through cone-beam CT (CBCT) and high-definition motion management (HDMM) systems. Intra-fraction motion measured between localization, repeat localization and post-treatment CBCTs were correlated to intra-faction motion indicated by the HDMM files using the Pearson coefficient (r). A total of 302 plans were reviewed from 263 patients (114 male, 149 female); 216 pairs of localization-repeat localization, and 260 localization-post-treatment CBCTs were analyzed against HDMM logs.
View Article and Find Full Text PDFBackground/aim: To evaluate the feasibility of syngeneic mouse models of breast cancer by analyzing the efficacy of immune checkpoint inhibitors (ICIs) and potential predictive biomarkers.
Materials And Methods: To establish the murine triple-negative breast cancer (TNBC) models, JC, 4T1, EMT6, and E0771 cells were subcutaneously implanted into female syngeneic mice. When the tumor reached 50-100 mm, each mouse model was divided into a treatment (using a murine PD-1 antibody) and a no-treatment control group.
Introduction: We conducted a study to evaluate the dosimetric feasibility of mask-based cobalt-60 fractionated stereotactic radiotherapy (mcfSRT) with the Leksell Gamma Knife® Icon™ device.
Methods: Eleven patients with intracranial tumours were selected for this dosimetry study. These patients, previously treated with volumetric arc therapy (VMAT), were re-planned using mcfSRT.
Purpose: Competing radiosurgery plans are compared based on their conformity and gradient of dose distribution to the target volume (TV). Most widely used quality metrics such as new conformity index (NCI) and gradient index (GI) are known to have strong volume dependency on the TV of interest. A simple quality measure without the volume dependency is presented for evaluating stereotactic radiosurgery plans, expressed in distance dimension compared to the unit-less volume ratio used in NCI and GI.
View Article and Find Full Text PDFBreast cancer remains a leading cancer burden among women worldwide. Acquired resistance of cyclin-dependent kinase (CDK) 4/6 inhibitors occurs in almost all hormone receptor (HR)-positive subtype cases, comprising 70% of breast cancers, although CDK4/6 inhibitors combined with endocrine therapy are highly effective. CDK4/6 inhibitors are not expected to cooperate with cytotoxic chemotherapy based on the basic cytotoxic chemotherapy mode of action that inhibits rapidly proliferating cells.
View Article and Find Full Text PDFPurpose: To investigate whether there is a volume threshold in target volume of brain metastases below which a small cone size and sharp penumbra in Gamma Knife (GK) may provide improved plan quality when compared to Volumetric Modulated Arc Therapy (VMAT)-based stereotactic radiosurgery (SRS).
Methods: For patients treated on GK SRS for brain metastases in 2018-2019 in our institution, 121 patients with two and three targets were identified. Twenty-six patients with two or three brain metastases (total of 76 lesions) were selected for this study.
Introduction: Using multi-isocenter volumetric-modulated arc therapy (VMAT) for total body irradiation (TBI) may improve dose uniformity and vulnerable tissue protection compared with classical whole-body field technique. Two drawbacks limit its application: (1) VMAT-TBI planning is time consuming; (2) VMAT-TBI plans are sensitive to patient positioning uncertainties due to beam matching. This study presents a robust planning technique with image-guided delivery to improve dose delivery accuracy.
View Article and Find Full Text PDFEpithelial ovarian cancer remains the leading cause of mortality among all gynecologic malignancies owing to recurrence and ultimate development of chemotherapy resistance in the majority of patients. In the chemotherapy-resistant ovarian cancer preclinical model, we investigated whether AZD6738 (an ataxia telangiectasia and Rad3-related (ATR) inhibitor) could synergize with belotecan (a camptothecin analog and topoisomerase I inhibitor). In vitro, both chemotherapy-resistant and chemotherapy-sensitive ovarian cancer cell lines showed synergistic anti-proliferative activity with a combination treatment of belotecan and AZD6738.
View Article and Find Full Text PDFRecently, cyclin-dependent kinase (CDK) 4/6 inhibitors have been widely used to treat advanced hormone receptor-positive breast cancer. Despite promising clinical outcomes, almost all patients eventually acquire resistance to CDK4/6 inhibitors. Here, we screened genes associated with palbociclib resistance through genomics and transcriptomics in preclinical breast cancer models.
View Article and Find Full Text PDFBackground: Well-characterized preclinical models are essential for immune-oncology research. We investigated the feasibility of our humanized mouse model for evaluating the long-term efficacy of immunotherapy and biomarkers.
Methods: Humanized mice were generated by injecting human fetal cord blood-derived CD34+ hematopoietic stem cells to NOD-scid IL2rγnull (NSG) mice myeloablated with irradiation or busulfan.
Appl Microbiol Biotechnol
August 2020
Cyclo(Phe-Pro) (cFP), produced by the Vibrio species, plays the dual roles of being a signaling molecule and a virulence factor. Acting modes of this compound have recently been characterized at the molecular level. Nevertheless, the method by which this compound passes across biological membranes remains obscure.
View Article and Find Full Text PDFPurpose: Brain metastases (BrM) are common in patients with epidermal growth factor receptor (EGFRm) mutant non-small cell lung cancer (NSCLC). We sought to determine the rate of neurologic death (ND) in this population.
Methods And Materials: We analyzed data from 198 patients who received a diagnosis of BrM from EGFRm NSCLC between 2004 and 2016, comparing patients whose initial treatment for BrM was stereotactic radiosurgery with or without tyrosine kinase inhibitors (TKI), whole brain radiation therapy (WBRT) with or without TKI, or TKI alone.
Acetate is the main by-product from microbial succinate production. In this study, we performed acetate removal by Methanosarcina barkeri 227 for succinate fermentation by Actinobacillus succinogenes 130Z. The acetoclastic methanogen M.
View Article and Find Full Text PDFPurpose: The integral quality monitor (IQM) is a real-time radiotherapy beam monitoring system, which consists of a spatially sensitive large-area ion chamber, mounted at the collimator of the linear accelerator (linac), and a calculation algorithm to predict the detector signal for each beam segment. By comparing the measured and predicted signals the system validates the beam delivery. The current commercial version of IQM uses an analytic method to predict the signal, which requires a semi-empirical approach to determine and optimize various calculation parameters.
View Article and Find Full Text PDFThe aim of the study is to determine PTV margin for inter-observer variability in the volumetric modulated arc therapy (VMAT) prostate radiotherapy with high-dose volumetric CT (HDVCT) and conventional helical CT (CCT) for planning. Secondly to investigate the impact of geometric (PTV expansion) and dosimetric (conformity) imperfection of planning process on the PTV margin analysis. Prostate gland of ten patients were scanned with CCT and HDVCT techniques consecutively on a 320 slice volumetric CT scanner with wide field detector of 16 cm.
View Article and Find Full Text PDFActinobacillus succinogenes is a natural succinate producer, which is the result of fumarate respiration. Succinate production from anaerobic growth with C -dicarboxylates requires transporters catalysing uptake and efflux of C -dicarboxylates. Transporter Asuc_1999 (DcuE) found in A.
View Article and Find Full Text PDFPurpose: This work describes the performance characterization of a cone-beam CT-guided radiosurgery device, the Gamma Knife Icon™.
Methods: The performance tests have been categorized into: (a) image quality and mechanical integrity; (b) image coregistration fidelity; (c) adaptive treatment delivery quality; (d) high definition motion management performance characterization; (e) software communication performance testing of the integrated cone-beam CT (CBCT) system.
Results: All image quality performance characterization satisfied or exceeded manufacturer specifications.