Risk factors of pneumothorax and chest tube placement after computed tomography-guided core needle biopsy of lung lesions : a single-centre experience with 822 biopsies

Purpose: To determine the risk factors of pneumothorax and chest tube placement after computed tomography-guided core needle lung biopsy (CT-CNB). Material and methods: Variables that could increase the risk of pneumothorax and chest tube placement were retrospectively analysed in 822 CT-CNBs conducted with 18-gauge non-coaxial CT-CNB in 813 patients (646 men and 167 women; range: 18-90 years; mean: 59.8 years). Predictor variables were age, gender, patient position, severity of pulmonary emphysema, lesion size and localisation, contour characteristics, presence of atelectasis, pleural tag and fissure in the needle-tract, length of the aerated lung parenchyma crossed by the needle, needle entry angle, number of pleural punctures, experience of the operator, and procedure duration. All variables were investigated by ×2 test and logistic regression analysis. Results: The overall incidence of pneumothorax was 15.4% (127/822). Chest tube placement was required for 22.8% (29/127) of pneumothoraxes. The significant independent variables for pneumothorax were lesions smaller than 3 cm (p = 0.009), supine and lateral decubitus position during the procedure (p < 0.001), greater lesion depth (p = 0.001), severity of pulmonary emphysema (p < 0.001), needle path crossing the fissure (p < 0.001), and a path that skips the atelectasis (p < 0.001) or pleural tag (p < 0.001); those for chest tube placement were prone position (p < 0.001), less experienced operator (p = 0.001), severity of pulmonary emphysema (p < 0.001), and greater lesion depth (p = 0.008). Conclusions: The supine and lateral decubitus position, a needle path that crosses the fissure, and a path that skips the atelectasis or a pleural tag are novel predictors for the development of pneumothorax. Key words: computed tomography (CT), CT-guided core needle lung biopsy (CT-CNB), pneumothorax, chest tube, pulmonary lesion

The Broader Impact of Student-Scientist Partnership: Scientists’ Contribution to Students’ Understanding and Proficiencies of Science

This study aims to investigate the broader impacts of student-scientist partnership with an emphasis on scientists’ possible contributions to students’ understanding and proficiencies of science. Appeals from the National Science Foundation have specifically called for broader participation and direct involvement in science and the enhancement of research and education through the linking of scientists with other programs. The Botanical Society of America's PlantingScience project is a partnership of students, science teachers, and scientist-mentors working together in authentic science learning. This dissertation includes three papers. The first paper is an extensive literature review focusing on how scientists can contribute to students’ science learning via online mentoring. The second paper applies a grounded theory approach to build a theory that explains how scientists talk about science when they engage in inquiry activities with students and how this interaction occurs. The third study, which is a mixed methods study, investigates how scientists contribute to students’ science proficiencies and what kind of patterns exist between scientist-mentors and student-teams during inquiry engagement. The literature review reveals an information gap exploring how scientists reflect their understanding of science to K-12 students when they work together in a partnership model. This review pointed out three main questions regarding student-scientist partnerships via online mentoring: (1) What do scientists say about science when they engage in online dialogue about students’ inquiry projects? (2) What are the connections between scientists’ demographics, the subject of the inquiry, and the way they explain the nature of science? and (3) What is the relationship between the quality of students’ inquiries and what their mentors reveal about the nature of science in their dialogues? The results of the grounded theory study revealed the educational, social, and cultural means of the interaction between two parties-- students and scientists. Also, investigation of various cases allowed a better understanding of the essence of nature and culture of science from practitioners’ perspectives. Finally, the mixed methods study revealed that scientists contributed to the authenticity of students’ inquiry experiences by encouraging them to understand scientific explanations, generate scientific evidence with them, reflect on scientific knowledge, and participate productively in scientific discussions

Optimization of a condenser in a thermal power plant

Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.In this study, thermal power plant’s, based on Ideal Rankine Cycle, steam is condensed while the pressure of the condenser changes between 0.1 bar and 0.02 bar. The effect of this condensation on condenser area and effects to the cost is investigated. Change of rate of condenser area is calculated, relative to the condenser pressure drops. It is concluded that the area of condenser increases when the pressure of condenser decreases, accordingly the cooling water pump power changes. This result is discussed in the impact of energy production costs

Broadband, Stable, and Non-Iterative Dielectric Constant Measurement of Low-Loss Dielectric Slabs Using a Frequency-Domain Free-Space Method

A broadband, stable, and non-iterative free-space method is proposed for dielectric constant ε′r determination of low-loss dielectric slabs from reflection-only measurements through simple calibration standards (reflect and air). It is applicable for dispersive samples and does not require thickness information. Simulations of non-disperive and dispersive samples are performed to validate our method. Dielectric constant measurements of polyethylene and Polyoxymethylene samples (9–11 GHz) are carried out to examine the accuracy of our method. IEE

Effect of Needle-Tract Bleeding on Pneumothorax and Chest Tube Placement Following CT Guided Core Needle Lung Biopsy

Background: Bleeding in the biopsy tract has been studied for its ability to decrease the risk of pneumothorax with indefinite results in the previous studies. Purpose: To investigate the risk factors for needle-tract bleeding (NTB) and the possible effect of NTB on the pneumothorax and resultant chest tube placement after CT-guided cutting needle biopsy (CT-CNB) of pulmonary lesions. Methods: Predictive variables for NTB and the effect of NTB on the development of pneumothorax and consequent chest tube placement were retrospectively determined in 416 patients who had undergone an 18-gauge non-coaxial CT-CNB (338 men and 78 women; average age, 59.3 years). Patient-related parameters were age, gender, patient position, and severity of pulmonary emphysema. Lesion-related variables were size, localization, and contour characteristics of the lesion. Procedure-related variables were the presence of atelectasis, pleural tag, and fissure in the needle-tract, length of the aerated lung parenchyma crossed by needle, needle entry angle, number of pleural punctures, the experience of the operator, and procedure duration. All variables were analyzed by x2 test and logistic regression analysis. Results: NTB was demonstrated in 142 of 421 (33.7%) procedures. The predictive variables of NTB were smaller lesion size (p = 0.011) and greater lesion depth (p = 0.002). In patients without emphysema around the lesion, the pneumothorax developed in 44/190 cases (23.1%) without NTB and in 12/95 procedures (12.6%) with NTB (p < 0.001). Conclusion: NTB may have a preventive effect on pneumothorax development, particularly in the absence of emphysema around the lesion

Breast cancer in association with thyroid disorders

BACKGROUND: The relationship between breast cancer and thyroid diseases is controversial. Discrepant results have been reported in the literature. The incidences of autoimmune and nonautoimmune thyroid diseases were investigated in patients with breast cancer and age-matched control individuals without breast or thyroid disease. METHODS: Clinical and ultrasound evaluation of thyroid gland, determination of serum thyroid hormone and antibody levels, and fine-needle aspiration of thyroid gland were performed in 150 breast cancer patients and 100 control individuals. RESULTS: The mean values for anti-thyroid peroxidase antibodies were significantly higher in breast cancer patients than in control individuals (P = 0.030). The incidences of autoimmune and nonautoimmune thyroid diseases were higher in breast cancer patients than in control individuals (38% versus 17%, P = 0.001; 26% versus 9%, P = 0.001, respectively). CONCLUSION: Our results indicate an increased prevalence of autoimmune and nonautoimmune thyroid diseases in breast cancer patients