What is known and objectiveThe pharmacokinetics (PK) and pharmacodynamics (PD) of levofloxacin were investigated following administration of levofloxacin injection in healthy Chinese volunteers for optimizing dosing regimen.MethodsThe PK study included single-dose (750 mg/150 mL) and multiple-dose (750 mg/150 mL once daily for 7 days) phases. The concentration of levofloxacin in blood and urine was determined using HPLC method. Both non-compartmental and compartmental analyses were performed to estimate PK parameters. Taking fCmax/MIC ≥5 and fAUC24 h/MIC ≥30 as a target, the cumulative fraction of response (CFR) of levofloxacin 750 mg for treatment of community-acquired pneumonia (CAP) was calculated using Monte Carlo simulation. The probability of target attainment (PTA) of levofloxacin at various minimal inhibitory concentrations (MICs) was also evaluated.Results and discussionThe results of PK study showed that the Cmax and AUC0–∞ of levofloxacin were 14·94 μg/mL and 80·14 μg h/mL following single-dose infusion of levofloxacin. The half-life and average cumulative urine excretion ratio within 72 h post-dosing were 7·75 h and 86·95%, respectively. The mean Css,max, Css,min and AUC0–τ of levofloxacin at steady state following multiple doses were 13·31 μg/mL, 0·031 μg/mL and 103·7 μg h/mL, respectively. The accumulation coefficient was 1·22. PK/PD analysis revealed that the CFR value of levofloxacin 750-mg regimen against Streptococcus pneumoniae was 96·2% and 95·4%, respectively, in terms of fCmax/MIC and fAUC/MIC targets.What is new and conclusionThe regimen of 750-mg levofloxacin once daily provides a satisfactory PK/PD profile against the main pathogenic bacteria of CAP, which implies promising clinical and bacteriological efficacy for patients with CAP. A large-scale clinical study is warranted to confirm these results.

As a novel comprehensive report of a Chinese population, this study reveals that epidemiological characteristics of MND patients were similar to those observed in international populations. MND is age-related, male gender predominant, and may be associated with both environmental and genetic risk factors.

We investigated the temperature dependence of the density-of-states in the iron-based superconductor SmO1−xFxFeAs (x = 0, 0.12, 0.15, 0.2) with high resolution angle-integrated photoemission spectroscopy. The density-of-states suppression is observed with decreasing temperature in all samples, revealing two characteristic energy scales (10 meV and 80 meV). However, no obvious doping dependence is observed. We argue that the 10 meV suppression is due to an anomalously dopingindependent normal state pseudogap, which becomes the superconducting gap once in the superconducting state; and alert the possibility that the 80 meV-scale suppression might be an artifact of the polycrystalline samples.