Numerical analysis of thermal decomposition for RDX, TNT, and Composition B.

Demilitarization of waste explosives on a commercial scale has become an important issue in many countries, and this has created a need for research in this area. TNT, RDX and Composition B have been used as military explosives, and they are very sensitive to thermal shock. For the safe waste treatment of these high-energy and highly sensitive explosives, the most plausible candidate suggested has been thermal decomposition in a rotary kiln. This research examines the safe treatment of waste TNT, RDX and Composition B in a rotary kiln type incinerator with regard to suitable operating conditions. Thermal decomposition in this study includes melting, 3 condensed phase reactions in the liquid phase and 263 gas phase reactions. Rigorous mathematical modeling and dynamic simulation for thermal decomposition were carried out for analysis of dynamic behavior in the reactor. The results showed time transient changes of the temperature, components and mass of the explosives and comparisons were made for the 3 explosives. It was concluded that waste explosives subject to heat supplied by hot air at 523.15K were incinerated safely without any thermal detonation.

Correlation between obesity and clinicopathological factors in patients with papillary thyroid cancer.

PURPOSE: Epidemiological studies have shown that obesity is associated with an increased risk of thyroid cancer. However, the exact nature of the relationship, especially with respect to the behavior of the cancer, remains uncertain. The objective of this study was to evaluate the correlation between the body mass index (BMI) and clinicopathological features of thyroid cancer patients. METHODS: From January 2009 to April 2010, 716 consecutive patients (602 females and 114 males; mean age 47.02 ± 11.73 years) with papillary thyroid cancer (PTC) were analyzed retrospectively. Patients were divided into two subgroups according to age (<45 years, ≥45 years). The BMI groupings were based on standardized categories set by the World Health Organization. The relationships between the BMI and these parameters were assessed. RESULTS: A non-overweight BMI was associated with a younger age and female gender. Tumor multiplicity was related to a higher BMI. In an age-related subgroup analysis, a higher BMI was correlated with more lymph node involvement (p = 0.004), lymphatic invasion (p = 0.003) and tumor multiplicity (p = 0.008) in patients ≥45 years of age. The absence of an association between the BMI and T stage, nodal status, vascular invasion, lymphatic invasion, and extrathyroidal extension was noted in a statistical analysis. In the subgroup of patients <45 years of age, no positive associations were observed between the BMI and any parameters other than age and sex. CONCLUSIONS: In PTC patients ≥45 years of age, a higher BMI was associated with more aggressive tumor features, such as lymph node metastasis, lymphatic invasion, and tumor multiplicity.

Comparison of surgical outcomes between endoscopic and robotic thyroidectomy.

OBJECTIVES: Gasless transaxillary endoscopic thyroidectomy offers a distinct advantage over the conventional open operation because it leaves no visible neck scar. Indications have expanded with the development of new surgical techniques and instruments. However, because of the two-dimensional view and the nonflexible instruments, this procedure is not easily amenable for total thyroidectomy. So, robotic surgery has been introduced and offers improved visualization and dexterity. But, it remains unclear whether robotic thyroidectomy offers any potential benefits over endoscopic thyroidectomy. The aim of this present study was to determine whether robotic surgery is superior to endoscopic surgery through a comparison of surgical outcomes. METHODS: Between May 2009 and February 2011, 165 patients underwent endoscopic thyroidectomy (endoscopy group) and 46 patients underwent robotic thyroidectomy (robot group). A gasless transaxillary approach was used in both groups. The two groups were compared in terms of patient characteristics, perioperative clinical results, pathologic findings, and postoperative complication. RESULTS: Both patient groups were similar in terms of patient characteristics, mean number of retrieved central lymph nodes, pathological features, length of hospital stays, postoperative complication rate, and serum Tg level. However, the mean total operation time for thyroidectomy was 126.2 ± 37.84 min in the endoscopy group and 179.6 ± 44.34 min in the robot group (P < 0.001). Postoperative total drainage for lobectomy was 153.3 ± 45.64 for the endoscopy group and 179.9 ± 49.15 for the robot group (P = 0.031). Cost effectiveness is also an important consideration when evidence for predominance of two surgical techniques is lacking. The mean cost of robotic thyroidectomy was $6,655, compared with $829 for endoscopic thyroidectomy (P < 0.001). There was no significant difference in postoperative complications as hypocalcemia, recurrent laryngeal nerve injury, chyle leakage and tracheal injury in the two groups (P = 0.332). CONCLUSION: Robotic thyroidectomy was lengthier in duration than endoscopic thyroidectomy, more costly, and associated with increased postoperative drainage with no improvement in oncologic outcomes or complication rates. Therefore our data do not support any advantage of robotic surgery over endoscopic surgery.

Microsatellite instability is associated with the clinicopathologic features of gastric cancer in sporadic gastric cancer patients.

PURPOSE: Replication error is an important mechanism in carcinogenesis. The microsatellite instability (MSI-H) of colorectal cancers is associated with the development of multiple cancers. The influence of MSI-H on the development of multiple gastric cancers in sporadic gastric cancer patients has not been defined. This study was performed to reveal the association between the clinicopathologic features and MSI in sporadic gastric cancers. MATERIALS AND METHODS: Between July 2004 and March 2009, the clinicopathologic characteristics, including MSI status, were evaluated in 128 consecutive patients with sporadic gastric cancers. None of the patients had hereditary non-polyposis colorectal cancer of familial gastric cancer. The markers that were recommended by the NCI to determine the MSI status for colorectal cancers were used. RESULTS: MSI-H cancers were found in 10.9% of the patients (14/128). Synchronous gastric cancers were shown in 4 patients (3.1%). Synchronous cancers were found in 2 of 14 patients with MSI-H gastric cancer (14.3%) and 2 of 114 patients with MSS gastric cancer (1.8%; P=0.059, Fisher's exact test). Among the patients with synchronous cancer 50% (2/4) had MSI-H cancer, but 9.7% of the patients (12/124) without synchronous cancer had MSI-H cancer. MSI-H (RR, 24.7; 95% CI, 1.5~398.9; P=0.024) was related with to synchronous gastric cancer, but age, gender, family history, histologic type, location, gross morphology, size, and stage were not related to synchronous gastric cancer. CONCLUSIONS: MSI is associated with the intestinal-type gastric cancer and the presence of multiple gastric cancers in patients with sporadic gastric cancer. Special attention to the presence of synchronous and the development of metachronous multiple cancer in patients with MSI-H gastric cancer is needed.