Primary sternal chondrosarcoma, although rare, is the most common malignant tumor of the sternum. The gold standard treatment is complete surgical excision, which frequently causes the instability of ...the thorax necessitating future reconstruction. Local recurrence is common increasing the risk of distant metastasis.
A 60-year-old male patient was diagnosed with primary sternum chondrosarcoma and underwent surgical excision with negative resection margins. Later, he was found to have two local recurrences at 11 months and 37 months post initial excision. The two recurrences were surgically removed followed by local adjuvant radiation.
The seeding theories have been reported more frequently with relation to diagnostic biopsy procedures, tumor manipulation and self-seeding tumors. The patient developed two local recurrences despite total resection with negative margins, without concerns regarding seeding in distant metastasis.
Abstract
Background
Pulmonary carcinoid is a rare diagnosis with surgery remaining the standard treatment of choice. However, resection may impact patients’ daily activities due to decreased lung ...volume reserve and postoperative pain. Our study aims to compare the impact of different types of surgical resection on the post-operative quality of life with the application of a strict peri-operative pulmonary care program.
Methods
Patients who underwent surgery for bronchopulmonary carcinoid tumors in a tertiary cancer center between August, 2017 and March, 2020 were identified and demographic data was collected. Patients were contacted via phone for the qualitative and quantitative assessment of pain and quality of life, utilizing the Arabic version of Short-form McGill Pain Questionnaire and Activity of Daily Living (ADL) instrument respectively. Lung reserve was assessed before and after surgery. Statistical analysis used Chi-Square for categorical variables and ANOVA for continuous variables.
Results
A total of 16 patients underwent different type of resection. The majority were male (n = 10; 63%) with a mean age of 44 years (19–81). Most common clinical stage was stage I (n = 12, 75%) with typical carcinoid features recorded in more than half of the cases (n = 11, 69%). Almost all patients underwent surgical excision (n = 15, 94%) with negative resection margin and no major post-operative complications. Bilobectomy was the most frequent procedure (n = 6, 40%) and video-assisted thoracoscopic surgery (VATS) was utilized in 8 patients (50%). Expected changes were recorded in pre- and postoperative pulmonary function test with an average drop of 10 in FEV1 and 14 mL/min/mmHg in DLCO. The majority of patients (n = 15, 94%) were totally independent doing daily activities. Mild intermittent pain was found in 7 patients (44%) who scored an average intensity of 1.6 out of 10.
Conclusions
Excellent long-term outcomes can be achieved following surgical resection of pulmonary carcinoid tumors with little to no effect on patients’ lung function and quality of life in regard to performance status and post-operative pain when a good peri-operative pulmonary, physical rehabilitation, and pain management programs are adopted and strictly implemented.
Abstract
Background
Regardless of its rare occurrence, Thymoma remains the most frequently encountered primary tumor of the anterior mediastinum comprising about 50% of all masses in the region. ...Surgical resection, via thymectomy, remains the mainstay treatment modality. In locally advanced and borderline resectable tumors, neoadjuvant chemotherapy (NACT) may be utilized to increase the chance of R0 resection, raising the question of its efficacy and safety.
Methods
Demographic and clinical data from patients who presented to a tertiary cancer center between January 2015–October 2021 with a diagnosis of thymoma and underwent curative surgical resection was collected. Computed tomography scan was used to delineate clinical staging, tumor size and to detect post-therapeutic variations in tumor burden. The response evaluation criteria in solid tumors (RECIST) was used to classify the effect of NACT on tumor burden. The pathological response was determined by measuring the percentage of necrotic tissue.
Results
A total of 23 patients were diagnosed with thymoma. Most patients were male with a mean age 46 (± 15) years at diagnosis. The most common clinical stage was stage II with 5 patients (22%). A total of 12 patients had NACT as compared to 11 patients who had upfront surgery. The mean change in tumor volume was 165 cm
3
(p = 0.079) and the change in and maximum diameter was 1.53 ± 1.49 cm (p < 0.01). The effect of NACT on tumor burden based on RECIST criteria was minimal as 8 patients had stable disease. Based on pathological findings, the average necrotic portion of the tumor was 39.5% (p = 0.152). The overall survival rate is 95.65%, mean survival was 115 months (4–125). Recurrence occurred in 5 patients. The NACT group had a higher risk for recurrence (4; 33.3%) with a mean survival of 43.8 months compared to 59.6 months in those who did not receive induction therapy.
Conclusions
The exact role of induction chemotherapy in locally advanced thymoma patients remains controversial. NACT effect after utilizing radiological and pathological assessment tools was not found to significantly improve oncological outcomes compared to upfront surgery in locally advanced disease, with minimal radiologic and pathologic effect. To further demonstrate the impact of induction chemotherapy, we recommend multicentric collaborative studies.
Power system stabilizers (PSSs) associated with generators are mandatory requirements for damping low-frequency oscillations of a multimachine power system. Nevertheless, PSSs work well at particular ...network configuration and steady-state conditions for which they were designed. Therefore, the aim of this paper is the design of a robust PSS able to ensure the stability of the system for a wide range of loading conditions and various faults with higher performance. The main motivation for this design is to simultaneously shift as much as could be possible the lightly damped and undamped system electromechanical modes, at different loading conditions and system configurations, into pre-specified zone in the
s
-plane called D-shape sector. Hence, the problem of robustly tuning the PSSs parameters is formulated as a multiobjective optimization problem (MOP) with an eigenvalue-based objective functions. An improved version of non-dominated sorting genetic algorithms (NSGAII) is proposed to solve this MOP. The performance of the proposed NSGAII-based PSS (NSGAII-PSS) under different loading conditions, system configurations and disturbances is tested and examined for different multimachine power systems. Eigenvalue analysis and nonlinear simulations show the effectiveness and robustness of the proposed controllers NSGAII-PSSs and their ability to provide efficient damping of low-frequency oscillations.
Purpose
The association between papillary thyroid cancer (PTC) and Hashimoto’s thyroiditis (HT) remains a matter of debate. Several genetic and environmental factors have been found to influence this ...association. Because of the variation in these factors among different populations, we conducted a country- and region-based meta-analysis to examine whether the geographic area influences this association.
Methods
We searched PubMed and Web of Science databases for original articles that investigated the association between HT and PTC from February 1955 to February 28, 2023. The included studies were stratified according to their country and region of origin. Various subgroup analyses were conducted. The primary outcome was the pooled relative risk (RR) and its 95% confidence interval (CI) for each region and country.
Results
Forty-six studies including a total of 93,970 participants met our inclusion criteria. They originated from 16 countries distributed in five regions. Significant variation was found among countries but not among regions. Upon analysis of all 46 included studies, countries were classified based on their RR and its 95% CI. Excluding countries with pooled sample sizes <500, Sri Lanka (RR 4.23, 95% CI 2.91–6.14), Poland (RR 3.16, 95% CI 2.79–3.57) and Japan (2.68, 2.14–3.36) showed the strongest association between HT and PTC while Greece (RR 1.06, 95% CI 1.00–1.13), Spain (RR 0.70, 95% CI 0.23–2.11), and Jordan (0.62, 0.32–1.32) showed no significant association.
Conclusion
Our findings revealed a variation in the association between HT and PTC among countries but not among regions. The country-to-country variation could be due to certain genetic and/or environmental factors subject to geographic variation that influence this association. These findings may help guide health policies aiming to mitigate the risk of PTC in the HT population by helping identify high-risk and low-risk countries.
In the past two decades, conventional power system stabilizer (PSS) is widely used to damp power systems oscillations. Nowadays, several approaches based on intelligent techniques have been applied ...to PSS design problem. This paper deals with optimal design of multimachine power system stabilizers to improve the dynamic stability of power system. The design problem is formulated as an optimization problem. Non-Dominated Sorting Genetic Algorithm (NSGA-II) is employed to search the optimal PSS parameters.. Based on a three-machine nine-bus test system, nonlinear simulation results under disturbance, show the effectiveness of the proposed approach in power oscillation damping.
Direct catalytic oxidation of alcohols to acetals in one step process is very attractive, because the two steps process leads firstly to aldehydes, which are unstable species serving as reactive ...intermediates to generate several by‐products reducing process efficiency and selectivity. In this work, a new selective catalytic acetalization of 1‐butanol into 1‐1‐dibutoxybutane acetal using H2O2 in one step process is investigated using Keggin‐type polyoxometalates catalysts. The materials developed consisted of new lacunary phophotungstate salts Cs5MPW11(H2O)O39 (M=Fe, Co and Cu) which were prepared by inorganic solution condensation method and characterized using XRD, IR, SEM and EDX analysis to verify their structure, surface morphology and chemical composition. Cs5CuPW11(H2O)O39 catalyst allowed the highest performance for the oxidation of 1‐butanol at 60 °C using H2O2 excess with a yield approaching 92 % and a turnover number of 784. Such activity is related to a bifunctional behavior of the catalyst as superacid and redox operating system and the synergistic effect created between the PW11O397− Keggin framework, Cs+ and Cu2+.
Catalytic oxidation of 1‐butanol over lacunary POM salts modified by transition metals in the presence of H2O2 as oxidizing agent enables selective production of the acetal 1,1‐dibutoxybutane with yield approaching 92 % for the catalyst Cs5CuPW11(H2O)O39, such activity is related to a bifunctional behavior of the catalyst as superacid and redox operating system. This one‐step process avoids the formation of unstable by‐products.
