Methionine increases yolk production to offset the negative effect of caloric restriction on reproduction without affecting longevity in C. elegans.

Caloric restriction (CR) or Dietary restriction (DR) is known to improve health and in many cases increases lifespan. However, its negative effect on reproduction has not been fully studied. Practicing CR/DR without adequate knowledge on its side effect may risk complications such as infertility, birth defect, or malnutrition. In this study, by using several CR strategies in C. elegans, we examine key functions of reproduction including embryonic development and larvae growth. We find that CR significantly decreases the survival of embryos and slows the growth of the offspring. We further determine that defect in oocyte but not sperm is responsible for the compromised reproduction under CR. Interestingly, adding methionine to the medium reverses the reproduction defects, but does not affect the long lifespan resulted from CR. The beneficial effect of methionine on reproduction requires the yolk protein vitellogenin. CR down-regulates vitellogenin expression, which can be reversed by supplementing methionine in the food. Lacking the yolk protein transport due to rme-2 mutation blocks methionine's beneficial effects. Our study has revealed a novel, methionine-mediated genetic pathway linking nutrient sensing to reproduction and suggested methionine as a potential food supplement to mitigate the side effect of CR.

Controlled Layer-by-Layer Oxidation of MoTe2 via O3 Exposure.

Growing uniform oxides with various thickness on TMDs is one of the biggest challenges to integrate TMDs into complementary metal oxide semiconductor (CMOS) logic circuits. Here, we report a layer-by-layer oxidation of atomically thin MoTe2 flakes via ozone (O3) exposure. The thickness of MoO x oxide film could be tuning with atomic-level accuracy simply by varying O3 exposure time. Additionally, MoO x-covered MoTe2 shows a hole-dominated transport behavior. Our findings point to a simple and effective strategy for growing homogeneous surface oxide film on MoTe2, which is promising for several purposes in metal-oxide-semiconductor transistor, ranging from surface passivation to dielectric layers.

D2-resected stage IIIc gastric cancer patients benefit from adjuvant chemoradiotherapy.

Although adjuvant chemoradiotherapy has been an important part in the treatment of gastric cancer, whether or not adjuvant radiation can benefit patients undergoing resection with D2 lymph node dissection remains controversial. This retrospective study aimed to evaluate the role of adjuvant chemoradiotherapy on patients with D2-resected gastric cancer. A total of 337 patients with resected gastric cancer treated at Zhongnan Hospital of Wuhan University from 2004 to 2012 were retrospectively analyzed. Eligible patients were divided into the adjuvant chemoradiotherapy group (CRT; n = 124) and the adjuvant chemotherapy group (CT; n = 213). The primary endpoints were disease-free survival (DFS) and overall survival (OS), with toxicity as the secondary endpoint. A subgroup analysis was performed based on clinical staging. The two groups were comparable in baseline characteristic, except for the number of lymph nodes dissected. The median OSs in the CRT and CT groups were 51.0 months and 48.6 months, respectively (P = 0.251), and the median DFSs were 40.7 months and 31.2 months, respectively (P = 0.112). Subgroup analysis revealed that the median OSs in patients at stage IIIc in the CRT group and CT group were 29.0 and 23.0 months, respectively (P = 0.049), and those of the median DFSs were 21.2 and 15.1 months, respectively (P = 0.015). There was no significant difference in main adverse events between two groups. Collectively, adjuvant chemoradiotherapy in gastric cancer patients with D2 resection was well tolerated. For Stage IIIc patients, the addition of adjuvant chemoradiotherapy was associated with a significant benefit in both OS and DFS.