Search results for "PHOTOS"
showing 10 items of 701 documents
Physiological and Technical Aspects of Cactus Pear [Opuntia ficus-indica(L.) Mill.] Double Rellowering and Out-of-Season Winter Fruit Cropping
2007
Abstract A commercial cactus pear plantation in Sicily, Italy was manipulated to induce late cropping. The spring flush of flowers and cladodes were removed as was the second induced bloom of flowers and cladodes. The third induced bloom was harvested for a late out-of-season crop of cactus pear (Opuntia ficus-indica Mill.). The double removal induced a third flush of flowers and cladodes during late August with a fruit production that ripened the following winter (to March). The number of flowers per fertile cladode was halved after the double removal and the length of the fruit development period increased from 100-120 days to 160-190 days for the out-of-season crop. Polyethylene covering…
The coupling between electron transfer and protein dynamics in the bacterial photosynthetic reaction center: trapping of conformational substates in …
2004
The photosynthetic reaction center (RC) from purple bacteria is becoming a prototype in exploring the coupling between internal protein motions and long-range electron transfer (ET). This interplay has been extensively investigated by hampering RC substate interconversion and relaxations at low temperatures (McMahon et al., 1998, Biophys. J. 74, 2567). As a complementary approach for limiting RC dynamics at room temperature we embedded the protein within a dehydrated trehalose matrix. Spectroscopic studies and molecular dynamics simulations performed on myoglobin/trehalose/water systems have shown that the nonharmonic contributions to the protein motions (attributed to thermal fluctuations …
SYNTHESIS OF PYRROLO[3,2-H]QUINOLINONES WITH GOOD PHOTOCHEMOTHERAPEUTIC ACTIVITY AND NO DNA DAMAGE
2010
In the search for new photochemotherapeutic agents, a series of derivatives of the ring system pyrrolo[3,2-h]quinoline--bioisosters of the angular furocoumarin angelicin--were synthesized through a four-step synthetic approach, in reasonable overall yields. Eight of the synthesized derivatives showed a remarkable phototoxicity against a panel of four human tumor cell lines and a great dose UV-A dependence, reaching IC₅₀ values at submicromolar level. The mode of cellular death photoinduced by pyrrolo[3,2-h]quinolines was evaluated through a series of flow cytometric analysis and other tests were performed to clarify their mechanism of action.
An in vitro model to study cellular photosensitizer uptake and photodynamic dose-response relationships of tumor cells
1993
Cellular fluorescence intensity (CFI) after incubation with varying concentrations of the photosensitizer Photofrin and the photodynamically induced dose-response relationships of hamster melanoma cells (A-MEL-3) were studied in a recently developed in vitro model. After administration of Photofrin to the extracellular serum-free medium, CFI was evaluated by flow cytometry together with constantly fluorescing latex particles used as a reference. After 5 min, 50% of maximal CFI was found, and after 60 min CFI was maximal. No further increase was obtained during the exposure to Photofrin over the incubation period of 4 h. During this plateau phase, CFI was significantly related to the concent…
Successful treatment of adult multisystemic Langerhans cell histiocytosis with psoralen-UV-A, prednisolone, mercaptopurine, and vinblastine.
2008
Background Langerhans cell histiocytosis (LCH) is a rare disease with a peak incidence in childhood. There is limited experience with treatment options for adult patients having multisystemic LCH involvement. We report successful treatment of a 70-year-old woman with adult onset of LCH and multisystem disease (diabetes insipidus centralis, bone marrow infiltration, and lung and skin involvement). Observations A 70-year-old woman with erythematous plaques and papules of the submammary and inguinal skin attended our outpatient clinic and was diagnosed as having LCH. Organ involvement was found in the infundibulum of the pituitary gland, associated with diabetes insipidus centralis, bone marro…
PERSPECTIVE RESTITUTION FROM VIEW CAMERAS PHOTOS
2022
Abstract. The paper aims at discussing the accuracy of perspective restitution from view camera photos; view cameras are non-standard cameras frequently used in the past century for on field shooting of buildings and urban sites; this is why the reconstruction of lost buildings often deals with photos taken with a view camera. The case study chosen for the proposed experiment is an urban complex built in Palermo in the ‘50s. The site features a very regular layout with surfaces at right angle, that supports the graphic reconstruction of photos’ inner and outer orientation. The site has been surveyed with a laser scanner; the point cloud provided the metric information needed for the evaluat…
Synthesis and photocytotoxic activity of [1,2,3]triazolo[4,5-h][1,6]naphthyridines and [1,3]oxazolo[5,4-h][1,6]naphthyridines
2018
Abstract [1,2,3]Triazolo[4,5-h][1,6]naphthyridines and [1,3]oxazolo[5,4-h][1,6]naphthyridines were synthesized with the aim to investigate their photocytotoxic activity. Upon irradiation, oxazolo-naphtapyridines induced light-dependent cell death at nanomolar/low micromolar concentrations (EC50 0.01–6.59 μM). The most photocytotoxic derivative showed very high selectivity and photocytotoxicity indexes (SI = 72–86, PTI>5000), along with a triplet excited state with exceptionally long lifetime (18.0 μs) and high molar absorptivity (29781 ± 180 M−1cm−1 at λmax 315 nm). The light-induced production of ROS promptly induced an unquenchable apoptotic process selectively in tumor cells, with mitoch…
Insight on pyrimido[5,4-g]indolizine and pyrimido[4,5-c]pyrrolo[1,2-a]azepine systems as promising photosensitizers on malignant cells
2022
Searching for new small molecules as photosensitizing agents, we have developed a class of twenty-five pyrimido[5,4-g]indolizine and pyrimido[4,5-c]pyrrolo[1,2-a]azepines with a good substitution pattern defining a versatile synthetic pathway to approach the title ring system. All compounds were evaluated for their photocytotoxicity on a triple negative human breast cancer cell line (MDA-MB-231) in the dark and under UVA light (2.0 J/cm2). The most effective compounds exhibited a photoantiproliferative activity with IC50 values up to nanomolar ranges. Interestingly, these new developed compounds showed high selectivity towards cancerous cells with respect to non-cancerous ones. Moreover, fo…
The azulene scaffold from a medicinal chemist's perspective: Physicochemical and in vitro parameters relevant for drug discovery.
2022
Azulene is a bicyclic scaffold rarely applied in medicinal chemistry. Here we report physicochemical and in vitro parameters relevant for drug discovery for a series of diversely substituted azulenes. We synthesized and characterized several scaffold hopping series of analogously substituted azulenes, indoles and naphthalenes. This enabled a comparison of azulene with the more common scaffolds indole and naphthalene. Our data indicates that undesirably low photostability of azulenes is restricted to certain substitution patterns. Generally, we conclude that azulene is an underused lipophilic bicycle and should be considered as a valuable complement to the collection of medicinal chemistry s…
Recombinant water-soluble chlorophyll protein from Brassica oleracea var. Botrys binds various chlorophyll derivatives.
2003
A gene coding for water-soluble chlorophyll-binding protein (WSCP) from Brassica oleracea var. Botrys has been used to express the protein, extended by a hexahistidyl tag, in Escherichia coli. The protein has been refolded in vitro to study its pigment binding behavior. Recombinant WSCP was found to bind two chlorophylls (Chls) per tetrameric protein complex but no carotenoids in accordance with previous observations with the native protein [Satoh, H., Nakayama, K., Okada, M. (1998) J. Biol. Chem. 273, 30568-30575]. WSCP binds Chl a, Chl b, bacteriochlorophyll a, and the Zn derivative of Chl a but not pheophytin a, indicating that the central metal ion in Chl is essential for binding. WSCP …