P-glycoprotein (P-gp) and CYP3A (cytochrome P450 3A, generally; Cyp3a, rodent enzyme) in the intestine can attenuate absorption of orally administered drugs. While some suggest that P-gp enhances intestinal metabolism by CYP3A/Cyp3a during absorption of a dual substrate, others suggest that P-gp reduces the metabolism in the intestine when substrates are at subsaturating concentrations. Hence, ...

The distribution of perfluorinated compounds (PFCs) in Baiyangdian Lake, China, was determined in this study. Perfluorooctanoic acid (PFOA) was the dominant PFC in lake water (1.70–73.5 ng L , median 9.72 ng L ), while perfluorooctane sulfonate (PFOS) was the dominant PFC in sediments (0.06–0.64 ng g 1 dry wt, median 0.19 ng g 1 dry wt) and in aquatic animals (0.57–13.7 ng g 1 wet wt, median 2....

This month, as the surest route to public embarassment, I decided to write about scientific heroes. Today’s world is full of talk of mentoring. Graduate students are told to find supervisors who will intellectually nourish them, emotionally support them, and teach them networking and grantspersonship. As I tap away, I can almost hear Uncle Syd muttering that the world is going to the dogs. In h...

[email protected] For the past 28 years I have talked about him, usually when people asked about the patients I treated as a hospital doctor or when asked about heroes. He was an inauspicious man, wrinkled by the years and with lungs which bore witness to decades of smoking. Late one night and after a long weekend on-call, I received a message from admissions telling me of his chest infect...

Small-conductance Ca21-activated K1 channels (SK channels) influence the induction of synaptic plasticity at hippocampal CA3–CA1 synapses. We find that in mice, SK channels are localized to dendritic spines, and their activity reduces the amplitude of evoked synaptic potentials in an NMDA receptor (NMDAR)-dependent manner. Using combined two-photon laser scanning microscopy and two-photon laser...

Pete Seiler Mechanical Eng. Dept. U. of California-Berkeley Berkeley, CA 94720-1740, USA Phone: 1-510-642-6933 Fax: 1-510-642-6163 [email protected] Bong-Sob Song Mechanical Eng. Dept. U. of California-Berkeley Berkeley, CA 94720-1740, USA Phone: 1-510-642-6933 Fax: 1-510-642-6163 [email protected] J. Karl Hedrick Mechanical Eng. Dept. U. of California-Berkeley Berkeley,...

Viruses are curious life forms. Minimalistic and yet equipped with the evolvability to persist and proliferate, there’s clearly a lesson or two to be learned from them on survival. It is perhaps these very intrinsic qualities that have transformed some viruses into the deadliest known pathogens in the history of mankind. A viral epidemic has been the focus of many summer blockbuster movies, whe...

AIM The purpose of this study was to establish a general mathematical model for describing the mechanical behaviour of root canal instruments by combining a theoretical analytical approach with a numerical finite-element method. METHOD Mathematical formulas representing the longitudinal (taper, helical angle and pitch) and cross-sectional configurations and area, the bending and torsional ine...