99 research outputs found
Impact of 18F-FDG PET/CT on the staging of patients with non-small cell lung cancer
Background: Non-small cell lung cancer (NSCLC) accounts for approximately 80% of new diagnoses of pulmonary carcinoma. This study investigated the correlation between 18 F-fluorodeoxyglucose uptake in computerized tomography integrated positron emission tomography and tumor size, lymph node metastasis, and distant metastasis in patients with NSCLC.Methods: The records of 318 NSCLC patients (220 male, 98 females; mean age 60.94 years) were evaluated retrospectively.Results: 278 cases were adenocarcinomas; 28 squamous cell carcinomas; and 12 large cell carcinoma. When the cases were categorized according to tumor size (group 1, ≤3 cm; group 2, >3 and ≤5 cm; group 3, >5 cm), the maximum standardized uptake value (SUVmax) was significantly lower in groups 1 and 2 compared with group 3 (p<0,001 for each). Considering all cases, tumor SUVmax was not correlated with age, gender or histopathological type. Lymph node metastases were seen in 250 cases: 80.2% of these were adenocarcinomas, 71.4% squamous cell carcinomas, and 58.3% large cell carcinomas. Neither lymph node involvement nor distant metastases were correlated with tumor SUVmax, although lymph node size was positively correlated with lymph node SUVmax (r=0.758; p<0.001).Conclusions: SUVmax was significantly associated with tumor size, but not with distant metastases or lymph node involvement. Therefore, SUVmax on positron emission tomography is not predictive of the presence of metastases.
Can positron emission tomography - computed tomography imaging predict of metastases in patients with small cell lung cancer
Background: Small-cell lung cancer (SCLC) accounts for 15%-20% of all lung cancer cases. positron emission tomography - computed tomography (PET/CT) has become increasingly used as an initial staging tool in patients with SCLC. We aimed to explore the relationships between primary tumor 18F-FDG uptake measured as the maximum standardized uptake value (SUV max) and clinical stage at PET/CT for small cell lung cancer patients (SCLC).Methods: Patients with SCLC who underwent 18F-FDG PET/CT scans before the treatment were included in the study at Bach Mai hospital of Vietnam, from November 2014 to May 2018. The primary tumor and secondary lesion SUVmax was calculated; the tumor size was measured; the TNM status was determined mainly by FDG PET/CT imaging according to The 8th Edition of the TNM Classification for Lung Cancer were recorded. An evaluation was made of the linear relationship between tumor size, T stage, N stage, and M stages of the patients and their SUVmax using Spearman’s correlation.Results: Total 37 cases (34 men and 3 women; age range 38 - 81 years, median 64 years) were analyzed. The average of primary tumor size and SUVmax were 5.95±2.77 cm and 10.21±4.75, respectively. The SUVmax of primary tumor is significantly greater than that of nodal and distant organ metastasis (10.21±4.75 vs 8.20±4.35 and 6.44±3.17, p<0.01). There was a moderate correlation between SUVmax and tumor size (r =0.596, p<0.001), tumor stage (r = 0.502, p<0.01) but not significant with nodal stage (r =-0.218, p=0.194), metastasis stage (r = -0.055, p=0.747), and overall stage (r=-0.060, p=0.725).Conclusions: SUVmax was significantly correlated with tumor size, but not with distant metastases or lymph node involvement. Therefore, SUVmax on positron emission tomography is not predictive of the presence of metastases in patients with SCLC
Using positron emission tomography - computed tomography imaging to distinguish of metastatic disease from second primary lung tumours in patients with non-small cell lung cancer
Background: In NSCLC patients with multiple lesions, the differentiation between metastases and second primary tumours has significant therapeutic and prognostic implications. The aim of this retrospective study was to investigate the potential of 18F-FDG PET to discriminate metastatic disease from second primary lung tumours.Methods: Of 318 NSCLC patients between November 2015 and October 2018 at Bach Mai hospital, patients with a synchronous second primary lung cancer were selected. Patients with metastatic disease involving the lungs served as the control group. Maximum standardized uptake values (SUVs) measured with 18F-FDG PET were determined for two tumours in each patient. The SUVmax was determined and compared between the second primary group and metastatic disease group. Receiver-operating characteristic (ROC) curve analysis was performed to determine the sensitivity and specificity of the SUVmax for an optimal cut-off value.Results: A total of 81 NSCLC patients (44 metastatic disease, 37 second primary cancer) were included for analysis. The SUVmax was significantly higher in patients with second primary cancer than in those with metastatic disease (7.53±4.33 vs 4.35±2.58, respectively, p<0.001). The area under the ROC curve was 0.81 and the odds ratio for the optimal cut-off was 7.52.Conclusions: SUVmax from 18F-FDG PET images can be helpful in differentiating metastatic disease from second primary tumours in patients with synchronous pulmonary lesions. Further studies are warranted to confirm the consistency of these results.
Magnetic Resonance Imaging Features of Common Posterior Fossa Brain Tumors in Children: A Preliminary Vietnamese Study
BACKGROUND: Magnetic Resonance Imaging (MRI) nowadays plays an important role in the evaluation of posterior fossa brain tumours in children for appropriate diagnosis, treatment planning, and follow-up.
AIM: To assess the MRI features of common posterior fossa brain tumours including medulloblastomas, ependymomas, and pilocytic astrocytomas along with the postoperative parameters to contribute the local knowledge to the neuroradiology and neurosurgery fields.
METHODS: The study was performed at Children's Hospital 02 from January 2016 to June 2019. In this study, all pediatric patients adopted MRI to evaluate the posterior fossa brain tumours’ characteristics and then underwent surgery to eradicate the posterior fossa tumours. We retrospectively compared the baseline parameters, MRI parameters, and postoperative parameters among medulloblastomas, ependymomas, and pilocytic astrocytomas.
RESULTS: There were 62 patients (27 medulloblastomas, 20 ependymomas, and 15 pilocytic astrocytomas) in this research. The main structure of medulloblastomas and ependymomas was predominantly solid, whereas the main structure of pilocytic astrocytomas was superiorly cystic (p < 0.05). Ependymoma tended to extend tumour through foramina of Luschka and Magendie (p < 0.05). Medulloblastomas chiefly showed iso intensity on T2W and FLAIR images meanwhile ependymomas and pilocytic astrocytomas predominantly appeared hyperintensity on T2W and FLAIR images. Medulloblastomas and ependymomas were mostly high intensity on DWI, and low intensity on ADC whereas pilocytic astrocytomas were usually low intensity on DWI and high intensity on ADC. After injecting CE, pilocytic astrocytomas showed a mixed intensity whereas the signal intensity of medulloblastoma and ependymoma on T1CE was generally strong. There were positive correlations between FH diameter and estimated blood loss (r = 0.289, p < 0.05); and surgical time (r = 0.312, p < 0.05).
CONCLUSION: MRI plays a crucial role in demonstrating the features of posterior fossa brain tumours for appropriate diagnosis of medulloblastomas, ependymomas, and pilocytic astrocytomas. Medulloblastomas are problematic tumours and the clinicians should also take into consideration in cases of larger feet-to-head diameter of tumours to ensure the efficacy and safety surgery for patients
Modeling of parallel power MOSFETs in steady-state
In high-power applications, multiple power MOSFETs are connected in parallel
and treated as a single switch in order to handle much larger total currents.
In this paper, a parallel power MOSFETs model from the turnoff state until they
reach their steady state is introduced. The model represents the relationship
between each power MOSFET's gate voltage and the current distribution among
them. The study's key purpose is to use the model for dealing with the
asymmetry in sharing current and power loss between these semiconductor devices
during the steady state region.Comment: 10 pages, 7 figures, The 2023 INTERNATIONAL SYMPOSIUM ON ADVANCED
ENGINEERING (ISAE2023
STIRLING ENGINE: FROM DESIGN TO APPLICATION INTO PRACTICE AND EDUCATION
Stirling motor is a type of outside ignition heat motor that can utilize various fuel sources from customary structures (coal, oil, kindling, rice husk, and so forth) to sustainable power sources (sun-oriented energy), climate, squander heat usage, and so forth). The article centers around introducing the fundamental highlights of the improvement history, activity qualities, and plan techniques for certain sorts of Stirling motors, in this way offering useful appropriateness as well as a college preparing for understudies. The understudy studying Thermal Engineering in our nation today.
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Stemtech model in education 4.0: Designing height measuring instruments in grade 10
With the development in the fourth industrial revolution, there have been urgent demands for new human resources in the world. The mission set for the education sector is to prepare students with skills and knowledge in line with global standards to keep up with the industrial age 4.0. Among the educational trends that serve the fourth industrial revolution, STEM education has been demonstrating its superiority through various studies. This study applies the STEMTech model, which connects the fields of Science, Technology, Engineering, and Mathematics with a central technological factor, to create STEM products in the context of high schools in Vietnam recently. Firstly, the research trains students about STEM education, STEMTech model, and some new technologies; then divides the class into multiple groups of students to conduct a project based on STEMTech model; finally, surveys students. Statistical analysis was used to evaluate STEMTech model, whose results show that STEMTech model can engage students in learning, develop their creativity, and promote other competencies
Ultrasound versus Radiography for Evaluating Surgical Necrotizing Enterocolitis
Purpose:
Necrotizing enterocolitis (NEC) is an abdominal inflammatory condition that is common in premature neonates. Although abdominal radiograph (AR) remains the imaging standard for NEC, it may miss up to 50% of early signs of NEC and has been described to have a sensitivity as low as 15.4% for detecting pneumoperitoneum. Abdominal ultrasound (US) is portable, non-invasive, and allows real-time bowel integrity, movement, and perfusion assessment. We aim to evaluate the concordance between US and AR in detecting NEC features and the diagnostic performance of both modalities in detecting pneumoperitoneum.
Methods and materials:
We conducted an IRB-approved retrospective, cross-sectional, single-center study. We identified infants with a diagnosis of NEC confirmed by pathology reports that had a bowel US and AR studies obtained before surgery from January 2012 to August 2022. We extracted clinical and demographic data from our electronic chart system. Two pediatric radiologists, blinded to reports, evaluated the images to determine the presence of pneumatosis (PI), portal vein gas (PVG), bowel distension (BD), and pneumoperitoneum on both modalities. A third pediatric radiologist resolved discrepant responses. We calculated the diagnostic performance of both modalities to detect perforation based on the presence of pneumoperitoneum, and the concordance between them utilizing the kappa statistic (κ). We excluded studies with insufficient diagnostic quality.
Results
Our cohort included 9 girls and 22 boys, median age 23 days (IQR 14.5-55 days). Of those, 23 (76%) were born prematurely, and 20 had confirmed intestinal perforation. US demonstrated 35% sensitivity and 90% specificity, while AR demonstrated 15% sensitivity and 100% specificity. Agreement between US and AR was 10/30 (33.3%) for PI (κ=0.01), 22/28 (79%) for PVG (κ=0.2), 19/31 (61%) for BD (κ=0.21), and 24/31 (77%) for pneumoperitoneum (κ=0.34). Each feature was present more frequently on US than AR.
Conclusion:
Our study demonstrated that abdominal US was a valuable complementary tool for detecting NEC features and intestinal perforation. Despite a low to moderate agreement between both modalities, US consistently outperformed AR in identifying NEC features, including pneumoperitoneum. These findings highlight the significance of integrating US into the NEC diagnostic process and the need for revising the current NEC diagnostic algorithm. Future efforts include larger cohorts and a collaborative approach to improve the NEC diagnostic algorithm
Assessing status and habitat of siamese fireback (Lophura diardi) by using camera trap in Lo Go-Xa Mat National Park, Vietnam
Siamese fireback, Lophura diardi, belonging to Galliformes is at risk due to habitat loss and hunting, which are main challenges to conservation of the species. In order to provide scientific information to conserve the L. diardi, we implemented a camera-trap survey in Lo Go-Xa Mat National Park from 2017 to 2018. Occupancy and Poisson regression models were used to investigate presence of the species and potential factors influencing the occurrence of the species in the study area. Our results showed that the probability of occurrence of the species at locations within the park was high at 0.84 (0.69–0.92) and detection probability was relative low at 0.19 (0.16–0.23). The best models consistently suggested that the abundance of the species was high in closed canopy forest cover (β = 0.41), but appeared to be notably lower in areas far away from the ranger stations (β = -0.25) and in places with high frequency of human (β = -0.22). This research provided the first quantitative information of status and potential factors influencing occurrence of the L. diardi in the park, which is an essential data for developing practical actions to protect the species and monitoring program in the future for the park.        Â
A preliminary study to establish the transfected CHO cell lines which highly express Trastuzumab - A biosimilar product of Herceptin
Human epidermal growth factor receptor 2 (HER2) has been identified as a molecular target for breast cancer therapy, such as Trastuzumab (Herceptin®). This has been shown to improve patient survival substantially. The current study is aiming to locally produce an anti-HER2 monoclonal antibody (named Trastuzumab) which has an equivalent biological properties in comparison with the original version, Herceptin®). In silico design and construction of recombinant vectors, as well as the establishment of transfected cell lines with high expression of Trastuzumab were performed. Based on the protein sequences obtained from the Drugbank, the DNA sequences encoding for the light chain (Tras-Lc) and heavy chain (Tras-Hc) of Trastuzumab were optimized and integrated into pNanogen-Hygro and pNanogen-Puro vectors, respectively. The Neon Transfection System was used to co-transfect the pNanogen-Tras-Lc-Hygro and pNanogen-Tras-Hc-Puro constructs into CHO cells. Different co-transfected single-cell-colonies selected on media supplemented with hygromycin and puromycin were used for ELISA and SDS-PAGE assays to identify the CHO cell lines which highly express Trastuzumab. Based on the present results, 30μg of both constructs were suitable for DNA co-transfection. After 07 days of culture, the highest amount of Trastuzumab (561 µg/ml) was obtained from the H06LD68 cell line
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