Short- and Medium-term Atmospheric Effects of Very Large Solar Proton Events

Long-term variations in ozone have been caused by both natural and humankind related processes. In particular, the humankind or anthropogenic influence on ozone from chlorofluorocarbons and halons (chlorine and bromine) has led to international regulations greatly limiting the release of these substances. These anthropogenic effects on ozone are most important in polar regions and have been significant since the 1970s. Certain natural ozone influences are also important in polar regions and are caused by the impact of solar charged particles on the atmosphere. Such natural variations have been studied in order to better quantify the human influence on polar ozone. Large-scale explosions on the Sun near solar maximum lead to emissions of charged particles (mainly protons and electrons), some of which enter the Earth's magnetosphere and rain down on the polar regions. "Solar proton events" have been used to describe these phenomena since the protons associated with these solar events sometimes create a significant atmospheric disturbance. We have used the National Center for Atmospheric Research (NCAR) Whole Atmosphere Community Climate Model (WACCM) to study the short- and medium-term (days to a few months) influences of solar proton events between 1963 and 2005 on stratospheric ozone. The four largest events in the past 45 years (August 1972; October 1989; July 2000; and October-November 2003) caused very distinctive polar changes in layers of the Earth's atmosphere known as the stratosphere (12-50 km; -7-30 miles) and mesosphere (50-90 km; 30-55 miles). The solar protons connected with these events created hydrogen- and nitrogen- containing compounds, which led to the polar ozone destruction. The hydrogen-containing compounds have very short lifetimes and lasted for only a few days (typically the duration of the solar proton event). On the other hand, the nitrogen-containing compounds lasted much longer, especially in the Winter. The nitrogen oxides were predicted to increase substantially due to these solar events and led to mid- to upper polar stratospheric ozone decreases of over 20%. These WACCM results generally agreed with satellite measurements. Both WACCM and measurements showed enhancements of nitric acid, dinitrogen pentoxide, and chlorine nitrate, which were indirectly caused by these solar events. Solar proton events were shown to cause a significant change in the polar stratosphere and need to be considered in understanding variations during years of strong solar activity

Is cytoreductive surgery and hyperthermic intraperitoneal chemotherapy indicated in hepatobiliary malignancies?

Abstract Background Hepatopancreaticobiliary malignancies with peritoneal carcinomatosis exhibit poor survival with current therapies: hepatocellular carcinoma 11 months with sorafenib, and pancreaticobiliary 9–14 months with systemic chemotherapy. However, limited data exist on the utility of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in these patients. Methods We retrospectively reviewed our institutional hepatopancreaticobiliary malignancies with peritoneal carcinomatosis which underwent cytoreductive surgery and hyperthermic intraperitoneal chemotherapy from 2007 to 2017 and analyzed perioperative and oncologic outcomes. Results Seventeen patients were included: 9 hepatocellular carcinoma, 8 pancreaticobiliary (4 cholangiocarcinoma, 3 gallbladder, 1 pancreatic). Peritoneal cancer index, number of organs resected, completeness of cytoreduction, and 30-day morbidity were equivalent. Hepatocellular carcinoma received significantly less neoadjuvant therapy (11%, p = 0.008), though adjuvant therapy rates were similar. At a median follow-up of 15 months, progression-free survival was similar amongst all cohorts. However, overall survival was longer in hepatocellular carcinoma (42 months vs. cholangiocarcinoma 19 months, gallbladder 8 months, pancreatic 15 months, p = 0.206) with 59% 3-year overall survival (vs. 0% cholangiocarcinoma, 0% gallbladder, 0% pancreatic). Conclusions Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy may offer a survival benefit in select hepatocellular carcinoma patients with peritoneal carcinomatosis, though has dubious utility in pancreaticobiliary malignancies. </jats:sec

Is Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy Indicated in Hepatobiliary Malignancies?

Abstract Background Hepatopancreaticobiliary malignancies with peritoneal carcinomatosis (PC) exhibit poor survival with current therapies; HCC 11 months with sorafenib, pancreaticobiliary 9-14 months with systemic chemotherapy. Methods We retrospectively reviewed our institutional hepatopancreaticobiliary malignancies with PC which underwent CRS/HIPEC from 2007-2017 and analyzed perioperative and oncologic outcomes. Results 17 patients were included; 9 HCC, 8 pancreaticobiliary (4 cholangiocarcinoma, 3 gallbladder, 1 pancreatic). PCI (12 vs. 9), completeness of cytoreduction (78% vs. 75%) and 30-day morbidity (11% vs. 13%) were equivalent. HCC received less neoadjuvant therapy (11% vs. 75%, p=0.008), though adjuvant therapy rates were similar (78% vs. 100%, p=0.156). At a median follow-up of 15 months, PFS was similar (7 vs. 10 months p=0.957). However, OS was longer in HCC (42 vs. 15 months p=0.206) with 59% 3-year OS (vs. 0% pancreaticobiliary). Conclusions CRS/HIPEC may offer a survival benefit in select HCC patients with PC, though has dubious utility in PB malignancies.</jats:p

Is Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy Indicated in Hepatobiliary Malignancies?

Abstract Background: Hepatopancreaticobiliary malignancies with peritoneal carcinomatosis exhibit poor survival with current therapies; hepatocellular carcinoma 11 months with sorafenib, pancreaticobiliary 9-14 months with systemic chemotherapy. However, limited data exist on the utility of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in these patients. Methods: We retrospectively reviewed our institutional hepatopancreaticobiliary malignancies with peritoneal carcinomatosis which underwent cytoreductive surgery and hyperthermic intraperitoneal chemotherapy from 2007-2017 and analyzed perioperative and oncologic outcomes. Results: 17 patients were included; 9 hepatocellular carcinoma, 8 pancreaticobiliary (4 cholangiocarcinoma, 3 gallbladder, 1 pancreatic). PCI, number of organs resected, completeness of cytoreduction and 30-day morbidity were equivalent. Hepatocellular carcinoma received significantly less neoadjuvant therapy (11%, p=0.008), though adjuvant therapy rates were similar. At a median follow-up of 15 months, progression-free survival was similar amongst all cohorts. However, overall survival was longer in hepatocellular carcinoma (42 months vs. cholangiocarcinoma 19 months, gallbladder 8 months, pancreatic 15 months, p=0.206) with 59% 3-year overall survival (vs. 0% cholangiogarcinoma, 0% gallbladder, 0% pancreatic).Conclusions: Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy may offer a survival benefit in select hepatocellular carcinoma patients with peritoneal carcinomatosis, though has dubious utility in pancreaticobiliary malignancies.</jats:p