Alterations in the maternal endocrine, nutritional, and metabolic environment disrupt the developmental trajectory of the fetus, leading to adult diseases. Female offspring of rats, subhuman primates, and sheep treated prenatally with testosterone (T) develop reproductive/metabolic defects during adult life similar to those that occur after intrauterine growth retardation. In the present study we determined whether prenatal T treatment produces growth-retarded offspring. Cottonseed oil or T propionate (100 mg, im) was administered twice weekly to pregnant sheep between 30-90 d gestation (term = 147 d; cottonseed oil, n = 16; prenatal T, n = 32). Newborn weight and body dimensions were measured the day after birth, and postnatal weight gain was monitored for 4 months in all females and in a subset of males. Consistent with its action, prenatal T treatment produced females and males with greater anogenital distances relative to controls. Prenatal T treatment reduced body weights and heights of newborns from both sexes and chest circumference of females. Prenatally T-treated females, but not males, exhibited catch-up growth during 2-4 months of postnatal life. Plasma IGF-binding protein-1 and IGF-binding protein-2, but not IGF-I, levels of prenatally T-treated females were elevated in the first month of life, a period when the prenatally T-treated females were not exhibiting catch-up growth. This is suggestive of reduced IGF availability and potential contribution to growth retardation. These findings support the concept that fetal growth retardation and postnatal catch-up growth, early markers of future adult diseases, can also be programmed by prenatal exposure to excess sex steroids.

Graphene-based field-effect transistors (FETs) have been developed rapidly and are currently considered as an alternative for postsilicon electronics. In this study, polypyrrole-converted nitrogen-doped few-layer graphene (PPy-NDFLG) was grown on Cu substrate by chemical vapor deposition combined with vapor deposition polymerization and then transferred onto a flexible substrate. Furthermore, antivascular endothelial growth factor (VEGF) RNA aptamer conjugated PPy-NDFLG was integrated into a liquid-ion gated FET geometry to fabricate a high-performance VEGF aptamer-based sensor. Field-induced high sensitivity was observed for the analyte-binding events, eventually leading to the recognition of the target molecules at an unprecedentedly low concentration (100 fM). Additionally, the aptasensor had excellent reusability, mechanical bendability, and durability in the flexible process. The developed methodology describes, for the first time, the fabrication of N-doped graphene using conducting polymers including heteroatoms in their structures as the carbonization precursor and demonstrates its use in a high-performance, flexible FET-type aptasensor to detect vascular endothelial growth factor as a cancer biomarker.

No abstract

We demonstrate an 80-μm-thick film (which is around 15% of the thickness of the human epidermis), which is a highly sensitive hybrid functional gauge sensor, and was fabricated from poly(vinylidene fluoride) (PVDF) and ZnO nanostructures with graphene electrodes. Using this film, we were able to simultaneously measure pressure and temperature in real time. The pressure was monitored from the change in the electrical resistance via the piezoresistance of the material, and the temperature was inferred based on the recovery time of the signal. Our thin film system enabled us to detect changes in pressure as small as 10 Pa which is pressure detection limit was 103-fold lower than the minimum level required for artificial skin, and to detect temperatures in the range 20–120°C.

We have carried out the synthesis of side-chain rosin-ester-structured poly(ε-caprolactone) (PCL) through a combination of ring-opening polymerization and click chemistry. Rosin structures are shown to be effectively incorporated into each repeat unit of caprolactone. This simple and versatile methodology does not require sophisticated purification of raw renewable biomass from nature. The rosin properties have been successfully imparted to the PCL polymers. The bulky hydrophenanthrene group of rosin increases the glass-transition temperature of PCL by >100 °C, whereas the hydrocarbon nature of rosin structures provides PCL excellent hydrophobicity with contact angle very similar to polystyrene and very low water uptake. The rosin-containing PCL graft copolymers exhibit full degradability and good biocompatibility. This study illustrates a general strategy to prepare a new class of renewable hydrocarbon-rich degradable biopolymers.