Necrosis Depth and Photodynamic Threshold Dose with Redaporfin-PDT

Predicting the extent of necrosis in photodynamic therapy (PDT) is critical to ensure that the whole tumor is treated but vital structures, such as major blood vessels in the vicinity of the tumor, are spared. The models developed for clinical planning rely on empirical parameters that change with the nature of the photosensitizer and the target tissue. This work presents an in vivo study of the necrosis in the livers of rats due to PDT with a bacteriochlorin photosensitizer named redaporfin using both frontal illumination and interstitial illumination. Various doses of light at 750 nm were delivered 15 min postintravenous administration of redaporfin. Sharp boundaries between necrotic and healthy tissues were found. Frontal illumination allowed for the determination of the photodynamic threshold dose—1.5 × 10¹⁹ photons cm⁻³—which means that the regions of the tissues exposed to more than 11 mm of ROS evolved to necrosis. Interstitial illumination produced a necrotic radius of 0.7 cm for a light dose of 100 J cm⁻¹ and a redaporfin dose of 0.75 mg kg⁻¹. The experimental data obtained can be used to inform and improve clinical planning with frontal and interstitial illumination protocols.     

Fast and Efficient Method to Obtain Tagitinin F by Photocyclization of Tagitinin C

There is some evidence in the literature of the photocyclization reaction of Tagitinin C ( 1 ) to Tagitinin F ( 2 ). Compound 2 has high pharmacological potential, but it is not easy to obtain, while compound 1 is easily obtained from a widespread plant, Tithonia diversifolia. Among different reaction conditions monitored, one was found that allowed the cyclization of 1 into 2 in <15 min in a photo-dependent reaction. Scaling-up the photocyclization of the pure compound 1 into 2 demonstrated 100% yield, and the isolation of 2 from a UV-irradiated extract was eight-fold higher than the quantity isolated from the non-UV-irradiated extract. We were also able to better understand the process of photoconversion and determine methods to isolate and quantify these compounds, which are known for their important antitumoral activities among other important pharmacological properties.     

Effect of Photobiomodulation on Repairing Pressure Ulcers in Adult and Elderly Patients: A Systematic Review

Evaluation of photobiomodulation therapy (PBMT) in the treatment of pressure ulcers in adults and the elderly. Systematic review, based on the recommendations of the handbook, proposed by Cochrane. The search was carried out in databases, records of randomized clinical trials, list of references cited in the selected articles, as well as a manual search in meetings and specialized journals. A total of 1342 studies were identified, 18 were preselected and 5 were included in this review. Clinical heterogeneity of the participants was observed, in addition to variation in the laser parameters and predominance of studies of low methodological quality. PBMT with the use of laser (658 nm; 4 J cm⁻²;50 mw) showed complete wound healing (P < 0.001) when compared to lasers (990 nm and 808 nm). However, there was no statistically significant difference in relation to time to complete wound healing and in area reduction compared to standard care. PBMT in the infrared wavelength showed efficacy in the healing of the pressure ulcer, similar to the standard care presented in the different studies. PBMT (658 nm) was effective in promoting healing when compared to standard care. Laser can be a therapy of choice in the treatment of pressure ulcers, since no evidence has been found to refute its clinical application.     

Chemistry of diazafulvenium methides in the synthesis of functionalized pyrazoles

The chemistry of diazafulvenium methides generated by the thermal extrusion of sulfur dioxide from 2,2-dioxo-1H,3H-pyrazolo[1,5-c] [1,3]thiazoles is described. The diazafulvenium methides unsubstituted at C-7 participate in [8 pi + 2 pi] cycloadditions giving pyrazolo-annulated heterocycles resulting from the addition across the 1,7-position. 1-Methyl-diazafulvenium methides and 7,7-dimethyl-diazafulvenium methides undergo intramolecular sigmatropic [1,8]H shifts giving vinyl-1H-pyrazoles.     

The Dynamics of Apparent Horizons in Robinson–Trautman Spacetimes

We present an alternative scheme of finding apparent horizons based on spectral methods applied to Robinson–Trautman spacetimes. We have considered distinct initial data such as representing the spheroids of matter and the head-on collision of two non-rotating black holes. The evolution of the apparent horizon is presented. We have obtained in some cases a mass gap between the final Bondi and apparent horizon masses, whose implications were briefly commented in the light of the thermodynamics of black holes.     

A Poincaré type inequality for one-dimensional multiprojective foliations

We study one-dimensional holomorphic foliations on products of complex projective spaces and present results giving the number of singularities, counting multiplicities, of a generic foliation, a criterion for a foliation to be Riccati and a Poincaré type inequality, relating degrees of foliations to degrees of hypersurfaces which are invariant by them.     

Theoretical study of the decaying convective turbulence in a shear-buoyancy PBL

The derivation of a theoretical model for the decaying convective turbulence in a shear-buoyancy planetary boundary layer is considered. The model is based on the dynamical equation for the energy density spectrum in which the buoyancy, mechanical and inertial transfer terms are retained. The parameterization for the buoyancy and mechanical terms is provided by the flux Richardson number. Regarding the inertial term an approach employing Heisenberg’s spectral transfer theory is used to describe the turbulence friction, caused by small eddies, responsible for the energy dissipation of the large eddies. Therefore, a novelty in this study is to utilize the Adomian decomposition method to solve directly without linearization the energy density spectrum equation, with this the nonlinear nature of the problem is preserved. Therefore, the errors found are only due to the parameterization used. Comparison of the theoretical model is performed against large-eddy simulation data for a decaying convective turbulence in a shear-buoyancy planetary boundary layer. The results show that the existence of a mechanical turbulent driving mechanism reduces in an accentuated way the energy density spectrum and turbulent kinetic energy decay generated by the decaying convective production in a shear-buoyancy planetary boundary layer.     

An ellipsoidal frontier model: Allocating input via parametric DEA

This paper presents the ellipsoidal frontier model (EFM), a parametric data envelopment analysis (DEA) model for input allocation. EFM addresses the problem of distributing a single total fixed input by assuming the existence of a predefined locus of points that characterizes the DEA frontier. Numeric examples included in the paper show EFM’s capacity to allocate shares of the total fixed input to each DMU so that they will all become efficient. By varying the eccentricities, input distribution can be performed in infinite ways, gaining control over DEA weights assigned to the variables in the model. We also show that EFM assures strong efficiency and behaves coherently within the context of sensitivity analysis, two properties that are not observed in other models found in the technical literature.     

Derivatives of 10,16-dihydroxyhexadecanoic acid isolated from tomato (Solanum lycopersicum) as potential material for aliphatic polyesters

The main monomer of tomato cuticle, 10,16-dihydroxyhexadecanoic acid (or 10,16-dihydroxypalmitic acid; 10,16-DHPA), was isolated and used to efficiently synthesize two different monomers (16-hydroxy-10-oxo-hexadecanoic and 7-oxohexa-decanedioic acids) in addition to a dimer and linear and branched trimers. These compounds were fully characterized using NMR and MS techniques and could be used as starting materials for the synthesis of a wide range of chemicals and bio-polyesters, particularly the latter due to their physical properties, non-toxicity, and relative abundance among raw materials.     

Polymorphic screen and drug–excipient compatibility studies of the antichagasic benznidazole

The purpose of this study was to investigate the polymorphism and compatibility of benznidazole (BNZ), a drug used in the treatment of Chagas disease. This drug was subjected to a polymorphic screen using a number of solvents and precipitation procedures to explore the possible existence of different crystal structures of BNZ. The compatibility of BNZ with selected pharmaceutical excipients was evaluated in binary mixtures, in a ratio of 1:1 (w/w). These results were then analyzed with a variety of techniques, including differential scanning calorimetry, Fourier transform infrared spectroscopy, and X-ray powder diffractometry. No polymorphic forms of BNZ were detected despite some observed changes in the DSC profile. The thermal data indicate interaction of the drug with excipients hydroxyethylcellulose, polyethylene glycol, and hydroxypropyl-β-cyclodextrin. Additional studies using infrared spectroscopy confirm the incompatibility of BNZ with only the polyethylene glycol. This excipient should not be used in the development of solid dosage forms containing BNZ.