Thermal Hazard Evaluation of Cumene Hydroperoxide-Metal Ion Mixture Using DSC, TAM III, and GC/MS.

Cumene hydroperoxide (CHP) is widely used in chemical processes, mainly as an initiator for the polymerization of acrylonitrile-butadiene-styrene. It is a typical organic peroxide and an explosive substance. It is susceptible to thermal decomposition and is readily affected by contamination; moreover, it has high thermal sensitivity. The reactor tank, transit storage vessel, and pipeline used for manufacturing and transporting this substance are made of metal. Metal containers used in chemical processes can be damaged through aging, wear, erosion, and corrosion; furthermore, the containers might release metal ions. In a metal pipeline, CHP may cause incompatibility reactions because of catalyzed exothermic reactions. This paper discusses and elucidates the potential thermal hazard of a mixture of CHP and an incompatible material's metal ions. Differential scanning calorimetry (DSC) and thermal activity monitor III (TAM III) were employed to preliminarily explore and narrate the thermal hazard at the constant temperature environment. The substance was diluted and analyzed by using a gas chromatography spectrometer (GC) and gas chromatography/mass spectrometer (GC/MS) to determine the effect of thermal cracking and metal ions of CHP. The thermokinetic parameter values obtained from the experiments are discussed; the results can be used for designing an inherently safer process. As a result, the paper finds that the most hazards are in the reaction of CHP with Fe(2+). When the metal release is exothermic in advance, the system temperature increases, even leading to uncontrollable levels, and the process may slip out of control.

Low dose volume histogram analysis of the lungs in prediction of acute radiation pneumonitis in patients with esophageal cancer treated with three-dimensional conformal radiotherapy / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the predictive value of low dose volume of the lung on acute radiation pneumonitis (RP) in patients with esophageal cancer treated with three-dimensional conformal radiotherapy (3D-CRT) only, and to analyze the relation of comprehensive parameters of the dose-volume V5, V20 and mean lung dose (MLD) with acute RP.</p><p><b>METHODS</b>Two hundred and twenty-two patients with esophageal cancer treated by 3D-CRT have been followed up. The V5-V30 and MLD were calculated from the dose-volume histogram system. The clinical factors and treatment parameters were collected and analyzed. The acute RP was evaluated according to the RTOG toxicity criteria.</p><p><b>RESULTS</b>The acute RP of grade 1, 2, 3 and 4 were observed in 68 (30.6%), 40 (18.0%), 8 (3.6%) and 1 (0.5%) cases, respectively. The univariate analysis of measurement data:The primary tumor length, radiation fields, MLD and lung V5-V30 had a significant relationship with the acute RP. The magnitude of the number of radiation fields, the volume of GTV, MLD and Lung V5-V30 had a significant difference in whether the ≥ grade 1 and ≥ grade 2 acute RP developed or not. Binary logistic regression analysis showed that MLD, Lung V5, V20 and V25 were independent risk factors of ≥ grade 1 acute RP, and the radiation fields, MLD and Lung V5 were independent risk factors of ≥ grade 2 acute RP. The ≥ grade 1 and ≥ grade 2 acute RP were significantly decreased when MLD less than 14 Gy, V5 and V20 were less than 60% and 28%,respectively. When the V20 ≤ 28%, the acute RP was significantly decreased in V5 ≤ 60% group. When the MLD was ≤ 14 Gy, the ≥ 1 grade acute RP was significantly decreased in the V5 ≤ 60% group. When the MLD was >14 Gy, the ≥ grade 2 acute RP was significantly decreased in the V5 ≤ 60% group.</p><p><b>CONCLUSIONS</b>The low dose volume of the lung is effective in predicting radiation pneumonitis in patients with esophageal cancer treated with 3D-CRT only. The comprehensive parameters combined with V5, V20 and MLD may increase the effect in predicting radiation pneumonitis.</p>

Thermal hazard evaluation of lauroyl peroxide mixed with nitric acid.

Many thermal runaway incidents have been caused by organic peroxides due to the peroxy group, -O-O-, which is essentially unstable and active. Lauroyl peroxide (LPO) is also sensitive to thermal sources and is incompatible with many materials, such as acids, bases, metals, and ions. From the thermal decomposition reaction of various concentrations of nitric acid (HNO3) (from lower to higher concentrations) with LPO, experimental data were obtained as to its exothermic onset temperature (T0), heat of decomposition (ΔHd), isothermal time to maximum rate (TMRiso), and other safety parameters exclusively for loss prevention of runaway reactions and thermal explosions. As a novel finding, LPO mixed with HNO3 can produce the detonation product of 1-nitrododecane. We used differential scanning calorimetry (DSC), thermal activity monitor III (TAM III), and gas chromatography/mass spectrometer (GC/MS) analyses of the reactivity for LPO and itself mixed with HNO3 to corroborate the decomposition reactions and reaction mechanisms in these investigations.

Relationship of gross tumor volume with lymph node metastasis and prognosis of esophageal carcinoma / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To explore whether there is a relationship between gross tumor volume (GTV) and pathologic lymph node metastasis or prognosis of esophageal carcinoma, and to provide a new prognosis reference for esophageal carcinoma (EC).</p><p><b>METHODS</b>Six hundred and seven patients received radical resection of thoracic esophageal carcinoma from May 2002 to June 2006 in our hospital, and their pre-operative CT images were transmitted to the three-dimensional conformal radiotherapy planning system by the network in digital format. Esophageal GTV targets were outlined and their GTV volumes were calculated. To analyze whether there is a relationship between GTV volume and pathologic lymph node metastasis or prognosis.</p><p><b>RESULTS</b>In the 607 cases of esophageal carcinoma, the GTV volume was (22.5 ± 16.8) cm(3) in 374 stage N0 EC patients, significantly different from that of (30.4 ± 20.1) cm(3) in 233 stage N1 EC cases (P < 0.001). There is a significant difference between the GTV volumes of the groups with and without lymph node metastasis (P < 0.05). There was a significant difference of the GTV volumes of EC patients with one lymph node metastasis and those with ≥ 4 lymph node metastasis (P < 0.05). There was a positive correlation between GTV volume and the number of lymph node metastasis (r = 0.230, P < 0.001). The 1-, 3-, 5-year survival rates since the surgery date were 83.8%, 53.5%, and 36.4%, respectively. There was a significant difference between the survival rates of stage N0 (48.5%) and stage N1 patients (18.2%, P < 0.001), and there was a significant difference between the survival rats of patients with 0, 1 and ≥ 2 lymph node metastasis (P < 0.01). Cox regression model analysis showed that GTV volume, number of lymph node metastasis, pathological type, and lesion site were independent prognostic factors (all P < 0.05).</p><p><b>CONCLUSION</b>The GTV volume of esophageal carcinoma is positively correlated with the number of pathologic lymph node metastasis, and it is an independent prognostic factor for this cancer.</p>

Exploration of the classification of gross tumor volume and pathological staging of esophageal carcinoma / 中华肿瘤杂志

<p><b>OBJECTIVE</b>Using the volume calculating function of treatment planning system of 3DCRT to work out the value of GTV standard classifications and to provide the reference for clinical staging of esophageal carcinoma.</p><p><b>METHODS</b>Six hundred and seven patients underwent radical resection of thoracic esophageal carcinoma in our hospital, and their pre-operative CT images were transmitted in digital format to the three-dimensional conformal radiotherapy planning system by the network. Esophageal lesion GTV targets were outlined, and their volumes were automatically computed by the planning system. Compared the differences of the GTV volumes in different pathological T stages, and analyzed the relationship between GTV volumes and pathological T stages. According to the median volume of GTV at different pathological T stages, divided the values of GTV volume corresponding to different T stages and selected the suitable classification standard of GTV volume.</p><p><b>RESULTS</b>The esophageal carcinoma GTV length, maximum diameter and volume were related to pathological T staging and with a positive correlation (all P < 0.001). The Spearman correlation coefficient (r) was 0.376, 0.466 and 0.464, respectively, P < 0.001. Except that the length, maximum diameter and volume of GTV in pathological T3 and T4 had no significant difference, other indicators of the pathological T stages showed significant differences between the groups (P < 0.001). According to the median volume of GTV at different pathological T stages, the GTV volumes were divided into three grades: <or= 5.0 cm(3), 5.1 - 13.0 cm(3), and > 13.0 cm(3). When compared them with pathological T1, T2, and T3-T4 stages, the coincidence rate was 73.8%. The consistency was good between the GTV volume grades and pathological T stages (Kappa = 0.40, P < 0.001). The overall 5-year survival rates of GTV grades 1, 2, 3 were 78.1%, 31.5% and 33.5%, respectively (P < 0.0001). If the GTVs were divided into four grades: <or= 5.0 cm(3), 5.1 - 13.0 cm(3), 13.1 - 39.0 cm(3), and > 39.0 cm(3), the coincidence rate of GTV volume grades and pathology T staging was only 54.7%, and the consistency was poor, Kappa = 0.24, P < 0.001. The overall 5-year survival rate of GTV 1, 2, 3, 4 were 78.1%, 31.5%, 36.2% and 27.5%, respectively (P < 0.0001).</p><p><b>CONCLUSION</b>The length, maximum diameter and volume of esophageal carcinoma GTV are related to pathological T staging with a positive correlation. The classification that esophageal carcinoma GTVs divided into three grades has a good coincidence with the pathological T staging.</p>

Characteristics of the lymph node metastases and influencing factors and their value in target region delineation in postoperative radiotherapy for thoracic esophageal carcinoma / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To explore the distribution of lymph node metastases, to analyze the cliniopathologic factors of thoracic esophageal carcinoma after curative resection, and to provide the criteria of irradiated region delineation in radiotherapy for esophageal carcinoma.</p><p><b>METHODS</b>The clinicopathological data of 763 patients who underwent esophagecotomy from Jun 2002 to Jun 2006 were retrospectively analyzed. The regularity of lymph node metastases of thoracic esophageal cancer and clinicopathological factors were stratified and analyzed with SPSS13.0 software.</p><p><b>RESULTS</b>Of the 763 patients, a total of 5846 lymph nodes were dissected with an average of 7.7 lymph nodes in each case. Metastatic lymph nodes were 711, the ratio of metastatic lymph node was 12.2%, and 297 patients had lymph node involved, the lymph node metastasis rate was 38.9%. The metastatic lymph nodes of upper-thoracic esophagus were mainly observed in the supraclavicular and paratracheal regions (P < 0.05), the metastatic lymph nodes of middle-third thoracic esophagus were bidirectional, and those of the lower-third thoracic esophagus mainly metastasized to the regions adjacent to the esophagus, gastric cardia and gastric artery (P < 0.05). Both the metastasis ratio and rate of lymph nodes adjacent to the gastric artery in the lower-thoracic esophageal cancer were significantly higher than those in the middle-third and upper-third thoracic esophageal cancers (P = 0.007, P = 0.001). The multiple factors logistic regression analysis showed that tumor length, depth of tumor invasion, vascular tumor emboli and distant metastasis were major factors for lymphatic metastasis (P < 0.01). For the whole group of patients the lymph node metastatic rate was 28.5% in upper-thoracic esophageal cancer, significantly lower than 38.8% of the lower-thoracic esophageal cancer (P = 0.039) and 43.4% in the middle-thoracic esophageal cancer (P = 0.010). However, the lymph node metastatic rates were 37.0%, 37.9% and 41.4% in the upper-, middle- and lower-thoracic esophageal cancers of the 592 cases receiving left chest notches, with a non-significant difference among them (P = 0.715).</p><p><b>CONCLUSION</b>The lesion length, depth of tumor invasion, vascular tumor embolus and distant metastasis are the most important parameters for lymph node metastases. Operative modes have obvious influence on the distribution of regional lymph node metastases. Therefore, in the clinical management, a postoperative prophylactic radiotherapy may be selected according to the tumor length, depth of tumor invasion, vascular tumor embolus and distant lymph node metastasis.</p>