Prognostic role of PET/CT in endometrial cancer

Objectives: The present study evaluates the prognostic value of metabolic parameters related to the primary tumor identified in preoperative fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) scans in patients with endometrial cancer (EC).  Material and methods: This study included 120 patients with EC who underwent PET/CT in the preoperative period. The patients’ age, maximum standardized uptake value (SUVmax), SUVmean, metabolic tumor volume (MTV) and the total lesion glycolysis (TLG) value of the primary tumor on PET/CT; as well as the stage, histological subtype, grade and size of the primary EC; the degree of myometrial invasion (MI) cervical invasion (CI), lymphovascular invasion (LVI), lymph node metastasis (LNM) and distant metastasis (DM) were all recorded. The relationship of these factors with progression-free survival (PFS) and overall survival (OS) was evaluated.  Results: The study included 120 patients with EC with a mean age of 62.3 ± 0.02 years. Of the total, 32 patients died around the time of the analysis and 38 patients showed disease progression. The mean OS was 32.7 ± 1.6 months and the mean PFS was 30.5 ± 2.8 months. No significant relationship was identified between the SUVmax, SUVmean, MTV, TLG values, patient age, tumor size, histology, grade and MI degree, and OS or PFS. Disease stage, LVI, CI, LNM and DM were identified as prognostic factors for OS and PFS.  Conclusions: The present study found no significant relationship between preoperative PET parameters in EC and OS and PFS, although prospective studies involving a larger number of patients are required.

The value of PET/CT in determining lymph node metastasis of endometrial cancer

Objectives: In our study, the role of fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT) in determining lymph node metastasis of endometrial cancer was evaluated. Material and methods: The present retrospectively registered study included 80 patients with endometrial cancer who underwent PET/CT in preoperative period. The patients underwent total hysterectomy with bilateral salpingo-oophorectomy and lymph node dissection. Lymph node status was evaluated in histopathologic examination and PET/CT imaging and, the results were compared. Results: There were 80 patients (mean age 62 years) in the present study. Lymph node metastasis was detected in five patients, whereas 75 patients had no lymph node metastasis. A total of 1,471 lymph nodes were examined histopathologically, revealing benign findings in 1,433 (pelvic = 1018, paraaortic = 415) and malignant findings in 38 (pelvic = 28, paraaortic = 10) lymph nodes. The accuracy, sensitivity and specificity of PET/CT in determining lymph node metastasis was 95%, 80% and 96% in patient-based evaluation, and 97.4%, 78.9% and 98.6% in lymph node-based evaluation, respectively. The detection sensitivity of PET/CT was 0%, 81.4% and 100% in metastatic lymph nodes with a short diameter of ≤ 4 mm, 5–9 mm and ≥ 10 mm, respectively. PET/CT could detect 73.3% of metastatic lymph nodes that had < 10 mm short diameter. Conclusions: PET/CT is useful method in detecting lymph node metastasis especially that are disregarded by CT or MR in endometrial cancer. Although PET/CT doesn’t fully replace the surgical staging, its utilization in preoperative period may guide surgical procedure

Performance based study on the seismic safety of buildings

In the scope of this study, information has been provided on the Static Pushover Analysis which is a nonlinear deformation controlled analysis method and the Capacity Spectrum Method used to determine the performance point. In this study, static pushover analysis was made on a six-storey building with reinforcement concrete frame system by changing the materials, steel rebars and soil characteristics. The building’s capacity curves were drawn and decided according to different concrete and reinforcement groups. Furthermore the performance points of different classes of concrete were studied according to three seismic effect levels. In the case of a decrease in the reinforcement strength, a decrease of approximately 30% occurs in the base shear force. If the concrete strength is increased, an increase of 11% occurred in the base shear force. Consequently, in the comparisons made with five different concrete groups and two different reinforcement groups, rather than the increase in the strength of the concrete, an increase in the reinforcement strength was observed to be more effective on the structural capacity. Furthermore, local soil classifications were observed to be the most significant point regarding peak displacement

An experimental study on impact of anchor bars at the steel frames with infilled walls

In this study, a series of experimental study was conducted to investigate the effect of anchor bars on steel frame systems where the connections were provided by anchor bars between frame and infilled walls. Seven one over four scaled specimens having one story and one bay of frames were tested. Experimental study was carried out by damage-controlled and incrementally applied load up to loading cracks. The test results relieved that with the help of using anchor bars the capacity of energy absorption with initial stiffness were increased. It has been found that the frames without using anchor bars failure at the loading edge, the crushing behavior of infilled walls and separations at free edges were occurred. These observed failure behaviors replies with tensile cracking for the frames having anchor bars. There for it should be underlined that anchor bars have a significant effect on improving the behavior of the frames

Numerical investigation of reinforced concrete frame behavior subjected to progressive collapse

Progressive collapse is defined as the spread of an initial local failure of a structure. This phenomenon, caused by the removal of one or more load-bearing element, is followed by a chain of failures through the structure and ultimately leads to partial or even full collapse of an entire structure. As a result, an accurate understanding of structural behavior subjected to large displacements, caused by progressive collapse, is essential to ensure a safe structural design. A progressive collapse in buildings often starts with the removal of one or more columns and continues with the collapse of adjoining structural elements. Experimental studies on progressive collapse are generally not recommended because of its cost and safety reasons. Today, as a result of progress in computer technology, more complicated problems can be investigated numerically. In this study, a numerical model is used for nonlinear analysis of a reinforced concrete (RC) frame behavior subjected to progressive collapse. It is obtained that there is a good agreement between the results with those of the experimental study given in the literature. According to the results, it can be predicted numerically the response of an RC frame to progressive collapse at a highly accurate level

The prognostic significance of serum CA125 levels with ER, PR, P53 and Ki-67 expression in endometrial carcinomas

Objectives: The present study evaluates the relationship between the expression levels of hormone receptors (HRs), Ki-67, p53 and serum cancer antigen 125 (CA125) levels in endometrial cancer and clinicopathological risk factors, and determines their prognostic values. Material and methods: This retrospective study included 49 patients with endometrial cancer whose estrogen receptor (ER) and progesterone receptor (PR) Ki-67 and p53 expression levels were determined through immunohistochemical methods, and whose preoperative serum CA125 levels were measured. These factors relationship with various clinicopathological factors, progression-free survival (PFS) and overall survival (OS) was investigated. Results: The study included 49 patients with EC with a mean age of 61 ± 10 years. The rate of HR positivity was significantly higher in the endometrioid histology group than in the non-endometroid histology group (p = 0.026). A high level of Ki- 67 expression was found to be associated with a non-endometroid histology (p = 0.016), and a high tumor grade (p < 0.001) and a high p53 expression were found to be associated with advanced disease stage (p = 0.026). A positive correlation was found between p53 and Ki-67, a negative correlation was found between p53 and Ki-67 and the presence of HR. Significant relationship was not found between HR status, p53, Ki-67, CA125 and either other clinicopathological risk factors or survival. Conclusions: While HR positivity indicates favorable clinicopathological prognostic factors, high Ki-67 and high p53 expression indicate unfavorable ones. However, no direct effect of these factors on prognosis was found in this study

The effect of linear guide representation for topology optimization of a five-axis milling machine

Topology optimization is a countermeasure to obtain lightweight and stiff structures for machine tools. Topology optimizations are applied at component level due to computational limitations, therefore linear guides’ rolling elements are underestimated in most of the cases. Stiffness of the entire assembly depends on the least stiff components which are identified as linear guides in the current literature. In this study, effects of linear guide’s representation in virtual environment are investigated at assembly level by focusing on topology optimization. Two different contact models are employed for rolling elements in the linear guides. Reliability of the contact models are verified with experiments. After the verification, heavy duty cutting conditions are considered for the system and topology optimization is performed for two different contact models to reduce the mass of the structure. The difference caused by the representation of rolling elements is demonstrated for the same topology algorithm and the optimization results are compared for the models. Lastly, the effect of using more stiff linear guides in the five-axis milling machine is investigated by increasing the stiffness of the contact elements

Comparison of polymethylmethacrylate versus hydrophobic acrylic lenses for primary intraocular lens implantation in pediatric cataract surgery

AIM: To compare the visual results and postoperative complications of polymethylmethacrylate(PMMA)and hydrophobic acrylic intraocular lenses(IOLs)in children who underwent cataract extraction with primary IOL implantation.METHODS:This retrospective study included 117 eyes of 63 children with bilateral pediatric cataract undergoing cataract surgery and primary IOL implantation. The patients were divided into two groups, Group I included 58 eyes of 30 patients with PMMA IOLs; Group II included 59 eyes of 33 patients with hydrophobic acrylic IOLs. The clinical features, refraction errors, best corrected visual acuity(BCVA)and surgical complications were compared between two groups.RESULTS:The mean age at the time of surgery was 5.8(2-12)y and mean follow up period was 40.5(6-196)mo. Postoperatively, BCVA was ≥0.5 in 80 eyes(68.4%)and this was comparable in two groups. Visual axis opacification was seen in 28 eyes(48.3%)in Group I and 16 eyes(27.1%)in Group II and this difference was statistically significant(P=0.018). Postoperative IOL dislocation and posterior synechia formation were also noted. When all postoperative complications were considered, there were significantly less complications in the acrylic IOL group than PMMA IOL group(P=0.020).CONCLUSION: Pediatric cataract surgery with primary IOL implantation is a safe procedure. Hydrophobic acrylic IOLs may lead to less postoperative complications compared to PMMA IOLs

Can proliferative hypertrophic scars of the median sternotomy incision predict the occurrence and characteristics of urethral stricture?

Conclusion: A poorly healed median stemotomy incision scar can predict a poor wound healing in the urethra tissue. Further large scale, multi-center and prospective studies are needed to clarify this relationship

An efficient analog circuit sizing method based on machine learning assisted global optimization

Machine learning-assisted global optimization methods for speeding up analog integrated circuit sizing is attracting much attention. However, often a few typical analog IC design specifications are considered in most relevant research. When considering the complete set of specifications, two main challenges are yet to be addressed: (1) The prediction error for some performances may be large and the prediction error is accumulated by many performances. This may mislead the optimization and fail the sizing, especially when the specifications are stringent. (2) The machine learning cost could be high considering the number of specifications, considerably canceling out the time saved. A new method, called Efficient Surrogate Model-assisted Sizing Method for High-performance Analog Building Blocks (ESSAB), is proposed in this paper to address the above challenges. The key innovations include a new candidate design ranking method and a new artificial neural network model construction method for analog circuit performances. Experiments using two amplifiers and a comparator with a complete set of stringent design specifications show the advantages of ESSAB