Camptothecin-based nanodrug delivery systems

The drug camptothecin has a wide range of antitumor effects in cancers including gastric cancer,rectal and colon cancer,liver cancer,and lung cancer.Camptothecin-based drugs inhibit topoisomerase 1(Topo 1),leading to destruction of DNA,and are currently being used as important chemotherapeutic agents in clinical antitumor treatment.However,the main obstacle associated with cancer therapy is represented by systemic toxicity of conventional anticancer drugs and their low accumulation at the tumor site.In addition,low bioavailability,poor water solubility,and other shortcomings hinder their anticancer activity.Different from traditional pharmaceutical preparations,nanotechnology-dependent nanopharmaceutical preparations have become one of the main strategies for different countries worldwide to overcome drug development problems.In this review,we summarized the current hotspots and discussed a variety of camptothecin-based nanodrugs for cancer therapy.We hope that through this review,more efficient drug delivery systems could be designed with potential applications in clinical cancer therapy.

Effect of different film color mulching on dry matter and grain yield of oil flax in dry-land

Mulching can effectively maintain soil moisture;color of mulching film affects soil water storage capacity and further promote crop growth to improve grain yield.Field experiment was conducted to study effects of different film colors on dry matter accumulation(DMA)and grain yield of oil flax.Results showed that white plastic film mulching could increase leaf area,chlorophyll content and DMA.DMA of white film mulching and micro-ridge with soil covering was 53.0%higher than that of CK,and 7.8%higher than that of black film mulching.Mulching method also influenced DMA.Micro-ridge alone increased it by 13.7%than flat cultivation and soil covering improved another 7.6%under white film mulching.Both white and black film mulching with microridge could significantly improve grain yield.Black film mulching with micro-ridge and soil covering,white film mulching with micro-ridge and no soil covering significantly increased capsule number per plant,1,000-grain weight and grain yield of oil flax,compared with CK.Grain yield increased 29.0%and 28.9%respectively.These results indicated that the above mulching methods were suitable for high yield cropping pattern in dry-farming regions.

EFFECT OF FRACTIONAL ORDER PARAMETER ON THERMOELASTIC BEHAVIORS OF ELASTIC MEDIUM WITH VARIABLE PROPERTIES

This paper is concerned with the thermoelastic behaviors of an elastic medium with variable thermal material properties. The problem is in the context of fractional order heat conduction. The governing equations with variable thermal properties were established by means of the fractional order calculus. The problem of a half-space formed of an elastic medium with variable thermal material properties was solved, and asymptotic solutions induced by a sudden temperature rise on the boundary were obtained by applying an asymptotic approach. The propagations of thermoelastic wave and thermal wave, as well as the distributions of displacement, temperature and stresses were obtained and plotted. Variations in the distributions with different values of fractional order parameter were discussed. The results were compared with those obtained from the case of constant material properties to evaluate the effects of variable material properties on thermoelastic behaviors.

EFFECT OF FRACTIONAL ORDER PARAMETER ON THERMOELASTIC BEHAVIORS IN INFINITE ELASTIC MEDIUM WITH A CYLINDRICAL CAVITY

The thermal shock problems involved with fractional order generalized theory is studied by an analytical method. The asymptotic solutions for thermal responses induced by transient thermal shock are derived by means of the limit theorem of Laplace transform. An infinite solid with a cylindrical cavity subjected to a thermal shock at its inner boundary is studied. The propagation of thermal wave and thermal elastic wave, as well as the distributions of displacement, temperature and stresses are obtained from these asymptotic solutions. The investigation on the effect of fractional order parameter on the propagation of two waves is also conducted.