Systemic treatment of gastric cancer.

Gastric cancer is one of the commonest cancers worldwide and is associated with a poor prognosis. Surgery remains the only potentially curative treatment, but is associated with a high rate of locoregional recurrence. Hence, there is ongoing debate regarding both the extent of lymph node dissection and the role of perioperative chemotherapy or chemoradiation for localized disease. Untreated metastatic gastric cancer is associated with a median survival of only 3-4 months, but this can be increased to 8-10 months, associated with improved quality of life, with combination chemotherapy. Currently, no standard combination chemotherapy regimen exists, although regimens utilizing both cisplatin and 5-fluorouracil, such as epirubicin/cisplatin/fluorouracil (ECF), are amongst the most active. Newer chemotherapeutic agents, including irinotecan, oxaliplatin and taxanes, show promising activity, and are currently being tested in phase III trials.

Don Juan Pond, Antarctica: near-surface CaCl(2)-brine feeding Earth's most saline lake and implications for Mars.

The discovery on Mars of recurring slope lineae (RSL), thought to represent seasonal brines, has sparked interest in analogous environments on Earth. We report on new studies of Don Juan Pond (DJP), which exists at the upper limit of ephemeral water in the McMurdo Dry Valleys (MDV) of Antarctica, and is adjacent to several steep-sloped water tracks, the closest analog for RSL. The source of DJP has been interpreted to be deep groundwater. We present time-lapse data and meteorological measurements that confirm deliquescence within the DJP watershed and show that this, together with small amounts of meltwater, are capable of generating brines that control summertime water levels. Groundwater input was not observed. In addition to providing an analog for RSL formation, CaCl(2) brines and chloride deposits in basins may provide clues to the origin of ancient chloride deposits on Mars dating from the transition period from "warm/wet" to "cold/dry" climates.

Accelerated thermokarst formation in the McMurdo Dry Valleys, Antarctica.

Thermokarst is a land surface lowered and disrupted by melting ground ice. Thermokarst is a major driver of landscape change in the Arctic, but has been considered to be a minor process in Antarctica. Here, we use ground-based and airborne LiDAR coupled with timelapse imaging and meteorological data to show that 1) thermokarst formation has accelerated in Garwood Valley, Antarctica; 2) the rate of thermokarst erosion is presently ~ 10 times the average Holocene rate; and 3) the increased rate of thermokarst formation is driven most strongly by increasing insolation and sediment/albedo feedbacks. This suggests that sediment enhancement of insolation-driven melting may act similarly to expected increases in Antarctic air temperature (presently occurring along the Antarctic Peninsula), and may serve as a leading indicator of imminent landscape change in Antarctica that will generate thermokarst landforms similar to those in Arctic periglacial terrains.

Flood volcanism in the northern high latitudes of Mercury revealed by MESSENGER.

MESSENGER observations from Mercury orbit reveal that a large contiguous expanse of smooth plains covers much of Mercury's high northern latitudes and occupies more than 6% of the planet's surface area. These plains are smooth, embay other landforms, are distinct in color, show several flow features, and partially or completely bury impact craters, the sizes of which indicate plains thicknesses of more than 1 kilometer and multiple phases of emplacement. These characteristics, as well as associated features, interpreted to have formed by thermal erosion, indicate emplacement in a flood-basalt style, consistent with x-ray spectrometric data indicating surface compositions intermediate between those of basalts and komatiites. The plains formed after the Caloris impact basin, confirming that volcanism was a globally extensive process in Mercury's post-heavy bombardment era.