Search results for "PHOTOS"
showing 10 items of 701 documents
Comprehensive assessment of the microalgae-nitrifying bacteria competition in microalgae-based wastewater treatment systems: Relevant factors, evalua…
2022
[EN] Due to their capacity to assimilate carbon dioxide and nutrients, microalgae-based cultivation systems have emerged as a green solution for intensive wastewater treatment. However, when large concentrations of ammonium are present the competition between microalgae and ammonium-oxidising bacteria plays a significant role. Microalgae use ammonium to synthesise proteins, photosynthetic pigments and nucleic acids, while ammonium-oxidising bacteria use it as a source of electrons and oxidise it to nitrite.Several authors have studied the isolated factors that influence microalgae-nitrifying bacteria competition, although a comprehensive analysis of this interesting topic is still lacking. …
On-line monitoring of photosynthetic activity based on pH data to assess microalgae cultivation
2020
[EN] Microalgae performance of outdoor cultivation systems is influenced by environmental and operating dynamics. Monitoring and control systems are needed to maximise biomass productivity and nutrient recovery. The goal of this work was to corroborate that pH data could be used to monitor microalgae performance by means of data from an outdoor membrane photobioreactor (MPBR) plant. In this system, microalgae photosynthetic activity was favoured over other physical and biological processes, so that the pH data dynamics was theoretically related to the microalgae carbon uptake rate (CUR). Shortand long-term continuous operations were tested to corroborate the relationship between the first d…
CEFLES2: The remote sensing component to quantify photosynthetic efficiency from the leaf to the region by measuring sun-induced fluorescence in the …
2009
The CEFLES2 campaign during the Carbo Europe Regional Experiment Strategy was designed to provide simultaneous airborne measurements of solar induced fluorescence and CO<sub>2</sub> fluxes. It was combined with extensive ground-based quantification of leaf- and canopy-level processes in support of ESA's Candidate Earth Explorer Mission of the "Fluorescence Explorer" (FLEX). The aim of this campaign was to test if fluorescence signal detected from an airborne platform can be used to improve estimates of plant mediated exchange on the mesoscale. Canopy fluorescence was quantified from four airborne platforms using a combination of novel sensors: (i) the prototype ai…
SYNTHESIS AND PHOTOCHEMIOTHERAPEUTIC ACTIVITY OF THIOPYRANO[2,3-E]INDOL-2-ONES
2004
A series of derivatives of the new ring system thiopyrano[2,3-e]indol-2-one was prepared with the aim of obtaining new photochemotherapeutic drugs. Biological screenings were performed on this new class of photoactivable drugs and a strong antiproliferative effect was observed upon irradiation with UVA light. The compound bearing a methyl substituent at the pyrrole nitrogen resulted as the most interesting showing IC50 in the nanomolar range.
Porphyrin and phthalocyanine photosensitizers designed for targeted photodynamic therapy of colorectal cancer
2020
Colorectal cancer is of particular concern due to its high mortality rate count. Recent investigations on targeted phototherapy involving novel photosensitizers and drug-delivery systems have provided promising results and realistic prospects for a successful medical treatment. New research trends have been focused particularly on development of advanced molecular systems offering effective photoactive species which could be selectively delivered directly into the affected cells. Porphyrins and phthalocyanines have been considered extremely attractive for this purpose due to their molecular versatility, excellent photochemical properties and multifunctional nature. In this review it has bee…
THIOPYRANO[2,3-E]INDOL-2-ONES: ANGELICIN HETEROANALOGUES WITH POTENT PHOTOANTIPROLIFERATIVE ACTIVITY
2008
A new class of compounds, the thiopyrano[2,3-e]indol-2-ones, bioisosters of the angular furocoumarin angelicin, was synthesized with the aim of obtaining new photochemotherapeutic agents. In particular 7,8-dimethyl-thiopyranoindolone 6c s showed a remarkable phototoxicity and a great dose UVA dependence reaching IC(50) values at submicromolar level. This latter photoinduced a massive apoptosis and a remarkable photodamage to lipids and proteins. Although it did not intercalate DNA, it was able to cause photooxidation of DNA bases.
Double stimuli-responsive polysaccharide block copolymers as green macrosurfactants for near-infrared photodynamic therapy
2019
The NIR absorbing photosensitizer phthalocyanine zinc (PC(Zn)) was stabilized in aqueous media as water-dispersible nanoparticles with a reduction- and pH-responsive full polysaccharide block copolymer. A cellular uptake and also photo switchable intracellular activity of the cargo upon irradiation at wavelengths in the near infrared region were shown. The block copolymer was synthesized by applying a copper-free click strategy based on a thiol exchange reaction, creating an amphiphilic double-stimuli-responsive mixed disulfide. The dual-sensitive polysaccharide micelles represent a non-toxic and biodegradable green macrosurfactant for the delivery of phthalocyanine zinc. By encapsulation i…
Changes in the protein profile of Quercus ilex leaves in response to drought stress and recovery
2009
To characterize the molecular response of holm oak to drought stress and its capacity to recover 9-month-old Quercus ilex seedlings were subjected to three treatments for a 14-d period: (i) continuous watering to field capacity (control plants, W), (ii) no irrigation (drought treatment, D), and (iii) no irrigation for 7d followed by a watering period of 7d (recovery treatment, R). In drought plants, leaf water potential decreased from -0.72 (day 0) to -0.99MPa (day 7), and -1.50MPa (day 14). Shoot relative water content decreased from 49.3% (day 0) to 47.7% (day 7) and 40.8% (day 14). Photosystem II quantum yield decreased from 0.80 (day 0) to 0.72 (day 7) and 0.73 (day 14). Plants subjecte…
The effect of saline water on Phillyrea angustifolia L. seedlings
2013
Water limitations in the Mediterranean areas are very common and the use of saline water for plant irrigation is becoming a necessity. Salinity generally affects plant growth and physiological processes, and can eventually lead to leaf injuries and plant death. For these reasons, the selection of salt tolerant species is a priority for landscaping purposes in the Mediterranean areas. The objective of this study was to evaluate the effect of saline water on Phillyrea angustifolia plant performance. Seventy-five rooted cuttings were grown in the greenhouse in 4-liter pots and irrigated for 5 months with saline water at different NaCl concentrations for two consecutive years. In 2010, 45 plant…
The family of furocoumarins: Looking for the best photosensitizer for phototherapy
2008
Abstract Furocoumarins are widely used as photosensitizers in photochemical therapies against different skin disorders such as psoriasis and vitiligo. Absorption of near-UV light by the chromophore triggers a set of photoreactions related to the therapeutic properties of the technique: linkage of a furocoumarin to thymine DNA nucleobases preventing proliferation of pathogenic cells, or generation of highly reactive singlet oxygen in damaged tissues. The family of furocoumarins has been studied in depth for many years seeking a drug having the most remarkable set of properties to act as a photosensitizer. For this purpose, understanding the underlying photochemical mechanisms behind the effe…