Search results for "sun"

Design of novel artemisinin-like derivatives with cytotoxic and anti-angiogenic properties

2010

Abstract Artemisinins are plant products with a wide range of medicinal applications. Most prominently, artesunate is a well tolerated and effective drug for treating malaria, but is also active against several protozoal and schistosomal infections, and additionally exhibits anti-angiogenic, anti-tumorigenic and anti-viral properties. The array of activities of the artemisinins, and the recent emergence of malaria resistance to artesunate, prompted us to synthesize and evaluate several novel artemisinin-like derivatives. Sixteen distinct derivatives were therefore synthesized and the in vitro cytotoxic effects of each were tested with different cell lines. The in vivo anti-angiogenic proper…

Abstract 5109: Beyond malaria: Second career of artesunate as cancer drug

2017

Abstract More than a decade ago, we initiated a research program on the molecular pharmacology of phytochemicals derived from Chinese medicinal herbs. Bioactive plant extracts have been fractionated by chromatographic techniques. We isolated bioactive compounds and elucidated their chemical structures by nuclear magnetic resonance and mass spectrometry. A promising compounds was artemisinin from Artemisia annua L. and its semisynthetic compound artesunate. Artemisinin and artesunate are anti-malarial drugs. Our data indicated profound activity against cancer cells, but also against various viruses, Schistosoma, Trypanosoma, and even plant crown gall tumors. To elucidate the molecular mode o…

The broad-spectrum antiinfective drug artesunate interferes with the canonical nuclear factor kappa B (NF-κB) pathway by targeting RelA/p65.

2015

Infection with human cytomegalovirus (HCMV) is a serious medical problem, particularly in immunocompromised individuals and neonates. The success of standard antiviral therapy is hampered by low drug compatibility and induction of viral resistance. A novel strategy is based on the exploitation of cell-directed signaling inhibitors. The broad antiinfective drug artesunate (ART) offers additional therapeutic options such as oral bioavailability and low levels of toxic side-effects. Here, novel ART-derived compounds including dimers and trimers were synthesized showing further improvements over the parental drug. Antiviral activity and mechanistic aspects were determined leading to the followi…

Triplet stabilization for enhanced drug photorelease from sunscreen-based photocages

2021

[EN] Recently, sunscreen-based drug photocages have been introduced to provide UV protection to photoactive drugs, thus increasing their photosafety. Here, combined experimental and theoretical studies performed on a photocage based on the commercial UVA filter avobenzone (AB) and on the photosensitizing non-steroidal anti-inflammatory drug ketoprofen (KP) are presented unveiling the photophysical processes responsible for the light-triggered release. Particular attention is paid to solvent stabilization of the drug and UV filter excited states, respectively, which leads to a switching between the triplet excited state energies of the AB and KP units. Most notably, we show that the stabiliz…

Commentary. Regulation of drug and immune resistance by YY1 in cancer.

2010

Differential interactions of the broad spectrum drugs artemisinin, dihydroartemisinin and artesunate with serum albumin

2013

Artemisinin is a drug, widely used in malaria treatment. As the binding affinity of artemisinin and its derivatives dihydroartemisinin and artesunate to blood serum proteins might influence the effectiveness of the drug, binding of artemisinin and derivatives to serum albumin was studied under near physiological conditions. Binding kinetics indicate a simple, single-step association process for all artemisinin derivatives. The determined changes in enthalpy and entropy upon drug binding clearly indicate that hydrophobic forces are most important for artemisinin and dihydroartemisinin binding, whereas binding of artesunate is governed by both hydrophilic and hydrophobic forces. Key residues,…

Stolen innocence? Observance of the EU Directive on presumption of innocence by Spanish crime reporting

2021

This paper examines the compliance of Spanish crime reporting with the principles of the 2016 EU Directive on presumption of innocence, which aims at preventing the publication of information that might bias the public and the jurors against the suspect. A content analysis applied to a sample of 200 crime news stories published by eleven of the most popular print and online news platforms in 2018 reveals that the Spanish press coverage of crime is centered around the pre-trial and sentence stages, with little attention to the oral trial. The full name and the face portrait of the suspect appear in roughly one-third of the stories, but this overwhelmingly happens in news stories reporting on…

Non-thermal processes in coronae and beyond

2012

This contribution summarizes the splinter session "Non-thermal processes in coronae and beyond" held at the Cool Stars 17 workshop in Barcelona in 2012. It covers new developments in high energy non-thermal effects in the Earth's exosphere, solar and stellar flares, the diffuse emission in star forming regions and reviews the state and the challenges of the underlying atomic databases.

Results from the Fourth WMO Filter Radiometer Comparison for aerosol optical depth measurements

2018

Abstract. This study presents the results of the Fourth Filter Radiometer Comparison that was held in Davos, Switzerland, between 28 September and 16 October 2015. Thirty filter radiometers and spectroradiometers from 12 countries participated including reference instruments from global aerosol networks. The absolute differences of all instruments compared to the reference have been based on the World Meteorological Organization (WMO) criterion defined as follows: 95% of the measured data has to be within 0.005 ± 0.001∕m (where m is the air mass). At least 24 out of 29 instruments achieved this goal at both 500 and 865 nm, while 12 out of 17 and 13 out of 21 achieved this at 368 and 412 nm,…

Night, day, sunrise, sunset: do fish under snow and ice recognize the difference?

2008

1. Although boreal lakes are ice-covered for several months annually, little is known about the behaviour of fish under ice. To consider the reasons for diel vertical migrations (DVM) it is important to compare periods under ice as opposed to under open water. Echosounding provides a tool for non-intrusive continuous monitoring of fish, even in winter. 2. Changes in the vertical distribution of fish through six 48-h periods were monitored using a stationary, mounted echosounder that beamed vertically either from the bottom up or from the surface down from February to April, 2003. The up-beaming and down-beaming transducers were run alternately for 24 h each over the 48-h period. Standard ec…