Development of cordycepin formulations for preclinical and clinical studies

There is extensive literature on in vivo studies with cordycepin but these studies were generally conducted without validation of the various formulations, especially in terms of the solubility of cordycepin in the dosing vehicles used. Cordycepin is a promising drug candidate in multiple therapeutic areas and there is a growing interest in studies aimed at assessing the pharmacological activity of this compound in relevant animal disease models. It is likely that many reported in vivo studies used formulations in which cordycepin was incompletely soluble. This can potentially confound the interpretation of pharmacokinetics and efficacy results. Furthermore, the presence of particles in intravenously administered suspension can cause adverse effects and should be avoided. Here we present the results from our development of simple and readily applicable formulations of cordycepin based on quantitative solubility assessment. Homogeneous solutions of cordycepin were prepared in phosphate-buffered saline (PBS) at different pH levels, suitable as formulations for both intravenously and oral administration. For the purpose of high-dose oral administration we also developed propylene glycol (PPG)-based vehicles in which cordycepin is completely soluble. The stability of the newly developed formulations was also assessed, as well the feasibility of their sterilisation by filtration. Additionally, an HPLC-UV method for the determination of cordycepin in the formulations, which may also be useful for other purposes, was developed and validated. Our study could provide useful information for improvement of future preclinical and clinical studies involving cordycepin

Herbal Medicines for Parkinson's Disease: A Systematic Review of Randomized Controlled Trials

OBJECTIVE: We conducted systematic review to evaluate current evidence of herbal medicines (HMs) for Parkinson's disease (PD). METHODS: Along with hand searches, relevant literatures were located from the electronic databases including CENTRAL, MEDLINE, EMBASE, CINAHL, AMED, PsycInfo, CNKI, 7 Korean Medical Databases and J-East until August, 2010 without language and publication status. Randomized controlled trials (RCTs), quasi-randomized controlled trials and randomized crossover trials, which evaluate HMs for idiopathic PD were selected for this review. Two independent authors extracted data from the relevant literatures and any disagreement was solved by discussion. RESULTS: From the 3432 of relevant literatures, 64 were included. We failed to suggest overall estimates of treatment effects on PD because of the wide heterogeneity of used herbal recipes and study designs in the included studies. When compared with placebo, specific effects were not observed in favor of HMs definitely. Direct comparison with conventional drugs suggested that there was no evidence of better effect for HMs. Many studies compared combination therapy with single active drugs and combination therapy showed significant improvement in PD related outcomes and decrease in the dose of anti-Parkinson's drugs with low adverse events rate. CONCLUSION: Currently, there is no conclusive evidence about the effectiveness and efficacy of HMs on PD. For establishing clinical evidence of HMs on PD, rigorous RCTs with sufficient statistical power should be promoted in future

Measurement of the half-life of79Se with accelerator mass spectrometry

©2014 Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Sciences and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd. The accelerator mass spectrometry (AMS) is an effective method for the determination of the half-life of long-lived radionuclides. In this paper, we report a method for measurement of the half-life of 79Se. The number of 79Se atoms was determined from measured 79Se/Se absolute ratios with the AMS system at the China Institute of Atomic Energy and the decay rate of 79Se was determined by counting the emitted β-rays with a liquid scintillation spectrometer. The major improvements of our measurements include using the high abundance of an 79Se sample which was cooled for many years to exclude the interference of short-lived nuclides, the extraction of SeO2- molecular ions, that results in a suppression of the 79Br background by as much as about five orders of magnitude. Also, an AMS measurement of the absolute ratio of 79Se/Se was developed to avoid systematic errors. The results show that 79Se/Se is (2.35±0.12)×10-7 in the reference sample and the radioactivity of 79Se is (1.24±0.05) Bq/g, so the half-life of 79Se is (2.78±0.18)×105 a

Measurement of the half-life of79Se with accelerator mass spectrometry

The accelerator mass spectrometry (AMS) is an effective method for the determination of the half-life of long-lived radionuclides. In this paper, we report a method for measurement of the half-life of 79Se. The number of 79Se atoms was determined from measured 79Se/Se absolute ratios with the AMS system at the China Institute of Atomic Energy and the decay rate of 79Se was determined by counting the emitted β-rays with a liquid scintillation spectrometer. The major improvements of our measurements include using the high abundance of an 79Se sample which was cooled for many years to exclude the interference of short-lived nuclides, the extraction of SeO2- molecular ions, that results in a suppression of the 79Br background by as much as about five orders of magnitude. Also, an AMS measurement of the absolute ratio of 79Se/Se was developed to avoid systematic errors. The results show that 79Se/Se is (2.35±0.12)×10-7 in the reference sample and the radioactivity of 79Se is (1.24±0.05) Bq/g, so the half-life of 79Se is (2.78±0.18)×105 a

Enhanced energy transfer in heterogeneous nanocrystals for near infrared upconversion photocurrent generation

© 2017 The Royal Society of Chemistry. The key to produce inorganic heterogeneous nanostructures, and to integrate multiple functionalities, is to enhance or at least retain the functionalities of different components of materials. However, this ideal scenario is often deteriorated at the interface of the heterogeneous nanostructures due to lattice mismatches, resulting in downgraded performance in most hybrid nanomaterials. Here, we report that there is a narrow window in controlling temperature in a Lewis acid-base reaction process to facilitate epitaxial alignment during the synthesis of hybrid nanomaterials. We demonstrate a perfectly fused NaYF4:Yb,Tm@ZnO heterogeneous nanostructure, in which the semiconductor ZnO shell can be epitaxially grown onto lanthanide-doped upconversion nanoparticles. By achieving a matched crystal lattice, the interface defects and crystalline grain boundaries are minimized to enable more efficient energy transfer from the upconversion nanoparticles to the semiconductor, resulting in both enhanced upconversion luminescence intensity and superior photoelectrochemical properties. This strategy provides an outstanding approach to endow lanthanide-doped upconversion nanoparticles with versatile properties

Microscopic role of carbon on MgB2 wire for critical current density comparable to NbTi

Increasing dissipation-free supercurrent has been the primary issue for practical application of superconducting wires. For magnesium diboride, MgB2, carbon is known to be the most effective dopant to enhance high-field properties. However, the critical role of carbon remains elusive, and also low-field critical current density has not been improved. Here, we have undertaken malic acid doping of MgB2 and find that the microscopic origin for the enhancement of high-field properties is due to boron vacancies and associated stacking faults, as observed by high-resolution transmission electron microscopy and electron energy loss spectroscopy. The carbon from the malic acid almost uniformly encapsulates boron, preventing boron agglomeration and reducing porosity, as observed by three-dimensional X-ray tomography. The critical current density either exceeds or matches that of niobium titanium at 4.2 K. Our findings provide atomic-level insights, which could pave the way to further enhancement of the critical current density of MgB2 up to the theoretical limit