Search results for "LIGHT"
showing 10 items of 3575 documents
The Mechanism of Photoinhibition of Spinach Thylakoids
1990
There is conflicting evidence as to wether D1-protein is the primary target of photoinhibition [1] or P680, the reaction centre of photo-system II [2]. The present paper desribes photoinhibition within a two step process consisting of an oxygen radical induced inactivation at the QB-site followed by damage to reaction centre II through the degradation of the D1-protein.
Visible-light-induced oxidation of trans-ferulic acid by TiO2 photocatalysis
2012
Abstract The oxidation of trans-ferulic acid (C10H10O4) in aqueous TiO2 dispersion occurs via the formation of a charge-transfer complex on the TiO2 surface that is able to absorb visible light (λ ⩾ 400 nm). The main product is CO2, whereas secondary oxidation products are organic species such as vanillin, caffeic acid, homovanillic acid, and vanillylmandelic acid. Oxidation through the formation of a charge-transfer complex occurs only in the presence of specific TiO2 samples. Experiments in the absence of oxygen, in the presence of bromate ions and by using a phosphate-modified TiO2, have been carried out for investigating the reaction mechanism. In order to study the interaction between …
Production of biologically active light chain of tetanus toxin inEscherichia coli
1993
AbstractThe activity of the light (L) chain of tetanus toxin, and of mutants constructed by site-directed mutagenesis, was studied by expression and purification of the proteins from E. coli. Wild-type recombinant L chain (pTet87) was active in the inhibition of exocytosis from cultured bovine adrenal chromaffin cells, although at a level 5–15% of that of L chain purified from tetanus toxin. L chain mutants which terminated at Leu-438 (pTet89), or which contained a Cys-to-Ser mutation at residue 439 (pTet88) were equally as active as the full-length recombinant protein. The reduced activity of pTet87 L chain correlated with C-terminal proteolysis of the protein upon purification. A tryptic …
Cultural content of lighting for the discovery of archaeological heritage
2013
Archaeological sites, built landscapes of the past, represent the identity heritage for future generations. The aim of this article is to investigate and demonstrate the importance of the cultural identity reinforcement, which can be achieved by enhancing the historical heritage through the use of artificial lighting. The charm of an archaeological site or a monument comes from the perception of its whole environmental context, both for the functional lighting and the enhancement of the artistic and monumental. Light can turn into concrete matter both in interiors, in archaeological and urban spaces: combining innovative technologies, artificial light can be used to change the world, to sha…
Dentin tubule orientation determines odontoblastic differentiation in vitro: A morphological study.
2019
Odontoblasts are post-mitotic cells responsible for maintenance of the dentin, and are therefore important for dental health. In some cases, irreversible pulpitis leads to necrosis and consequently death of odontoblasts. Regenerative endodontics (RE) uses the concept of tissue engineering to restore the root canals to a healthy state, allowing for continued development of the root and surrounding tissue. Human dental pulp stem cells (hDPSCs) have been successfully used in RE to restore odontoblast function. Surface microgeometry is one of the most important factors involved in the induction of differentiation of hDPSCs into odontoblast-like cells. Although different authors have demonstrate…
«History’s stained canvas»: Uses and appropriations of medieval past in Enlightenment Historiography. The case of Peter «the cruel»
2020
The aim of this paper is to explore the political meanings of the medieval past in the historical understanding of individuals in the 18th century. Beyond the familiar Gothic myth, I will focus on the multilayered image of the monarch Peter of Castile (1334–1369), considered cruel, lustful and passionate in the eyes of enemies and historians. The aim is to analyse the different attitudes towards and uses of this historical figure (one that was quite problematic given the cultural values of the period), ranging from the most negative of connotations to the most passionate of defences and including some more ambiguous stances. For this analysis, I will explore certain Enlightenment debates th…
One-pot direct synthesis for multifunctional ultrasmall hybrid silica nanoparticles
2018
International audience; Ultrasmall silica nanoparticles (NPs), having hydrodynamic diameters under 10 nm are promising inorganic platforms for imaging and therapeutic applications in medicine. Herein is described a new way for synthesizing such kind of NPs in a one-pot scalable protocol. These NPs bear DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) ligands on their surface that can chelate different metals suitable for a wide variety of biomedical applications. By varying the ratio of the precursors, the hydrodynamic diameters of the particles can be controlled over the range of 3 to 15 nm. The resulting NPs have been characterized extensively by complementary techniques li…
Remote Sensing of Photoplethysmogram using Multi Spot Illumination
2018
The ability to remotely extract Photoplethysmogram (PPG) signals is of great interest. A novel approach to overcome motion related noise, based on a multi spot pattern was experimentally demonstrated. Improvement of PPG signal is presented.
Messenger RNA degradation is initiated at the 5′ end and follows sequence- and condition-dependent modes in chloroplasts
2011
Using reporter gene constructs, consisting of the bacterial uidA (GUS) coding region flanked by the 5' and 3' regions of the Chlamydomonas rbcL and psaB genes, respectively, we studied the degradation of mRNAs in the chloroplast of Chlamydomonas reinhardtii in vivo. Extending the 5' terminus of transcripts of the reporter gene by more than 6 nucleotides triggered rapid degradation. Placing a poly(G) tract, known to pause exoribonucleases, in various positions downstream of the 5' terminus blocked rapid degradation of the transcripts. In all these cases the 5' ends of the accumulating GUS transcripts were found to be trimmed to the 5' end of the poly(G) tracts indicating that a 5' → 3' exori…
Comparison Between Classic and Light Touch Massage on Psychological and Physical Functional Variables in Athletes: a Randomized Pilot Trial
2020
Background: Despite the general belief of the benefits and the widespread use of massage in sport field, there are limited empirical data on possible effectiveness of massage on psychological and physical functional variables.
 Purpose: The main objective of the present study was to compare the effectiveness of classical and light touch massage on psychological and physical functional variables in athletes.
 Setting: Athletic club of Valencia
 Participants: 20 amateur athletes were recruited from two athletic clubs.
 Research Design: A single-blind, randomized, pilot-placebo trial.
 Intervention: The subjects were randomly allocated to two different groups: a) Massa…