Toward “E-Ring-Free” Lamellarin Analogues: Synthesis and Preliminary Biological Evaluation

Since the discovery of anticancer properties of a naturally occurring hexacyclic marine alkaloid Lamellarin D, the attempts have been made to prepare its synthetic analogues and elucidate the effects of each structural component on their activity profile. While F-ring-free, A-ring-free and B-ring-open lamellarins are known, E-ring-free analogues have never been investigated. In this work, we developed a facile and straightforward synthetic method toward E-ring-free lamellarin analogues based on the [3+2]-cycloaddition. For the first time, we prepared several pentacyclic lamellarin analogues without E-ring in their structure and assessed their cytotoxicity in a panel of cancer cell lines in comparison with several hexacyclic lamellarins. E-ring-free lamellarins were devoid of cytotoxicity due to their poor solubility in cellular environment.     

Impact of Silicon Foliar Application on the Growth and Physiological Traits of Carthamus tinctorius L. Exposed to Salt Stress

Silicon - Althought safflower is a tolerant crop against many environmental stresses, but its yield and performance reduce under stress. The aim of this experiment was to investigate the effect of...     

Retraction Note: Multilevel modeling of the mechanical properties of graphene nanocomposites/polymer composites

Microsystem Technologies -     

Dynamic scheduling techniques for heterogeneous computing systems

There has been a recent increase of interest in heterogeneous computing systems, due partly to the fact that a single parallel architecture may not be adequate for exploiting all of a program's available parallelism. In some cases, heterogeneous systems have been shown to produce higher performance for lower cost than a single large machine. However, there has been only limited work on developing techniques and frameworks for partitioning and scheduling applications across the components of a heterogeneous system. In this paper we propose a general model for describing and evaluating heterogeneous systems that considers the degree of uniformity in the processing elements and the communication channels as a measure of the heterogeneity in the system. We also propose a class of dynamic scheduling algorithms for a heterogeneous computing system interconnected with an arbitrary communication network. These algorithms execute a novel optimization technique to dynamically compute schedules based on the potentially non-uniform computation and communication costs on the processors of a heterogeneous system. A unique aspect of these algorithms is that they easily adapt to different task granularities, to dynamically varying processor and system loads, and to systems with varying degrees of heterogeneity. Our simulations are designed to facilitate the evaluation of different scheduling algorithms under varying degrees of heterogeneity. The results show improved performance for our algorithms compared to the performance resulting from existing scheduling techniques.     

Nano-Theranostic Modality for Visualization of the Placenta and Photo-Hyperthermia for Potential Management of Ectopic Pregnancy

Ectopic pregnancy (EP) is the leading cause of maternity-related death in the first trimester of pregnancy. Approximately 98% of ectopic implantations occur in the fallopian tube, and expedient management is crucial for preventing hemorrhage and maternal death in the event of tubal rupture. Current ultrasound strategies misdiagnose EP in up to 40% of cases, and the failure rate of methotrexate treatment for confirmed EP exceeds 10%. Here the first theranostic strategy for potential management of EP is reported using a near-infrared naphthalocyanine dye encapsulated within polymeric nanoparticles. These nanoparticles preferentially accumulate in the developing murine placenta within 24 h following systemic administration, and enable visualization of implantation sites at various gestational stages via fluorescence and photoacoustic imaging. These nanoparticles do not traverse the placental barrier to the fetus or impact fetal development. However, excitation of nanoparticles localized in specific placentas with focused NIR light generates heat (>43 °C) sufficient for disruption of placental function, resulting in the demise of targeted fetuses with no effect on adjacent fetuses. This novel approach would enable diagnostic confirmation of EP when current imaging strategies are unsuccessful, and elimination of EP could subsequently be achieved using the same nano-agent to generate localized hyperthermia resulting in targeted placental impairment.     

Textural characteristics of activated carbons prepared from agricultural residues-review

Agricultural residues are the most available biomass resources in the world and can be exploited to produce various activated carbons at low cost. The textural properties of activated carbon, including surface area, pore size, pore size distribution, and certain surface functionalities are the main factors in the application of bio-based electrode materials for energy storage devices and electrochemical catalyst for CO₂ reduction reactions, gas adsorption and separation, in water and wastewater treatment. This paper reviews the physical characteristics of activated carbons produced from various biomass resources using different methods. The effects of different activation methods, sources of biomass, and other parameters on the surface properties such as specific surface area and pore volume of activated carbon are discussed. The differences in the characteristics of activated carbon made from different agricultural biomass resources under the same parameters are evaluated. Eventually, the application of abundant agricultural residues for fabricating supercapacitors' electrode materials is also discussed.     

Correction to: Direct and Residual Effects of Water Deficit Stress,Different Sources of Silicon and Plant-Growth Promoting Bacteria on Silicon Fractions in the Soil

Silicon - A Correction to this paper has been published: https://doi.org/10.1007/s12633-021-01161-w