Geospatial availability of breast cancer treatment modalities and hypothetical access improvement in Ghana: A nationwide survey.

Breast cancer in Ghana is a growing public health problem with increasing incidence and poor outcomes. Lack of access to comprehensive treatment in Ghana may be a contributing factor to its high mortality. The purpose of this study was to evaluate the availability of treatments nationwide and systematically identify high yield areas for targeted expansion. We conducted a cross-sectional, nationwide hospital-based survey from November 2020-October 2021. Surveys were conducted in person with trained research assistants and described hospital availability of all breast cancer treatments and personnel. All individual treatment services were reported, and hospitals were further stratified into levels of multi-modal treatment modeled after the National Comprehensive Cancer Network (NCCN) Framework treatment recommendations for low-resource settings. Level 3 included Tamoxifen and surgery (mastectomy with axillary lymph node sampling); Level 2 included Level 3 plus radiation, aromatase inhibitors, lumpectomy, and sentinel lymph node biopsy; Level 1 included Level 2 plus Her2 therapy and breast reconstruction. Hospitals were identified that could expand to these service levels based on existing services, location and personnel. The distance of the total population from treatment services before and after hypothetical expansion was determined with a geospatial analysis. Of the 328 participating hospitals (95% response rate), 9 hospitals had Level 3 care, 0 had Level 2, and 2 had Level 1. Twelve hospitals could expand to Level 3, 1 could expand to Level 2, and 1 could expand to Level 1. With expansion, the population percentage within 75km of Level 1, 2 and 3 care would increase from 42% to 50%, 0 to 6% and 44% to 67%, respectively. Multi-modal breast cancer treatment is available in Ghana, but it is not accessible to most of the population. Leveraging the knowledge of current resources and population proximity provides an opportunity to identify high-yield areas for targeted expansion.

Subchronic exposure to environmentally relevant concentrations of di-(2-ethylhexyl) phthalate differentially affects the colon and ileum in adult female mice.

Di(2-ethylhexyl) phthalate (DEHP) is a large-molecular-weight phthalate added to plastics to impart versatile properties. DEHP can be found in medical equipment and devices, food containers, building materials, and children's toys. Although DEHP exposure occurs most commonly by ingesting contaminated foods in the majority of the population, its effects on the gastrointestinal tract have not been well studied. Therefore, we analyzed the effects of subchronic exposure to DEHP on the ileum and colon morphology, gene expression, and immune microenvironment. Adult C57BL/6 female mice were orally dosed with corn oil (control, n = 7) or DEHP (0.02, 0.2, or 30 mg/kg, n = 7/treatment dose) for 30-34 days. Mice were euthanized during diestrus, and colon and ileum tissues were collected for RT-qPCR and immunohistochemistry. Subchronic DEHP exposure in the ileum altered the expression of several immune-mediating factors (Muc1, Lyz1, Cldn1) and cell viability factors (Bcl2 and Aifm1). Similarly, DEHP exposure in the colon impacted the gene expression of factors involved in mediating immune responses (Muc3a, Zo2, Ocln, Il6, and Il17a); and also altered the expression of cell viability factors (Ki67, Bcl2, Cdk4, and Aifm1) as well as a specialized epithelial cell marker (Vil1). Immunohistochemical analysis of the ileum showed DEHP increased expression of VIL1, CLDN1, and TNF and decreased number of T-cells in the villi. Histological analysis of the colon showed DEHP altered morphology and reduced cell proliferation. Moreover, in the colon, DEHP increased the expression of MUC2, MUC1, VIL1, CLDN1, and TNF. DEHP also increased the number of T-cells and Type 2 immune cells in the colon. These data suggest that subchronic DEHP exposure differentially affects the ileum and colon and alters colonic morphology and the intestinal immune microenvironment. These results have important implications for understanding the effects of DEHP on the gastrointestinal system.

Exploring the Psychosocial Impact of Living With HIV on Minority Older Women.

BACKGROUND: Among older adults, minority older women will account for 60% of the new HIV diagnoses. The psychosocial impact of living with HIV among this vulnerable population narrated by their own voices has been understudied. AIMS: The purpose of this study was to explore the psychosocial impact of living with HIV on minority older women. METHODS: In-depth interviews were conducted with 28 minority older women living with HIV at an Ambulatory Care Center HIV Clinic in South Florida. All interviews were audio-recorded and transcribed verbatim. Conventional content analysis was used to identify and define the major themes that emerged from the interviews. Questions included those concerning description of life after the HIV diagnosis, most challenging aspects of life after the diagnosis, and daily activities since the diagnosis. RESULTS: The analysis of the interview data led to five main themes: (I) Social Impact of HIV, (II) Threats to Health and Well-Being, (III) HIV as a Death Sentence, (IV) Spirituality, and (V) HIV Treatment Adherence. In their narratives, women described a myriad of psychosocial issues such as depressed mood, isolation, economic challenges, stigma, anhedonia of interest, fear of death, among others. CONCLUSIONS: There is a compelling empirical need for rapid implementation of a culturally tailored, holistic, low-cost, multistrategy intervention to early screen and reduce the psychosocial impact of HIV among minority older women.

Treating Acute Cervical Radiodermatitis with Photobiomodulation Therapy: A Report of Two Cases.

Objective: The objective of this study was to report the application of photobiomodulation therapy (PBMT) in the treatment of two patients diagnosed with acute cervical radiodermatitis (RD) induced by radiotherapy. Background data: An undesirable effect of radiotherapy, RD often poses a limitation to the continuity of treatment that can negatively affect the control and prognosis of the disease. RD is frequently associated with pain and aesthetic impairment and can significantly influence quality of life. Many agents used to prevent and treat RD do not have sufficient scientific evidence to support its use. Materials and methods: In both clinical cases, the patients presented RD degree 3 and were in drug treatment, with no satisfactory response, and PBMT was started. Two diode lasers were used, with a dose of 35.71 J/cm2, 10 sec/point, 100 mW of power, and a beam area of 0.028 cm2 and dose of 27.77 J/cm2, 25 sec/point, 40 mW, and 0.036 cm2 beam area. Both lasers were applied at the wavelength of red, daily, in contact and perpendicular to the skin, to deliver 1 J/point/1.5 cm, which covered the entire area affected with RD. Results: The PBMT made possible an expressive improvement in the healing process and reduction of painful symptoms associated with RD. Conclusions: Although PBMT facilitated healing and reduced pain experienced with RD, randomized controlled trials are needed to evaluate all of its possible benefits.

Fluorescence decay rate of selected compounds from Eysenhardtia polystachya extracts and their viability as biosensors.

Eysenhardtia polystachya (EP) is an endemic Mexican plant that has been widely studied for its antidiabetic, antibacterial, and antioxidant properties. Several studies had reported the main components of EP, but their fluorescence properties had not been broadly studied. In a previous study we obtained extracts with different composition from this plant and they presented florescence. In this work we study fluorescent compounds from EP and evaluate their fluorescence properties. EP extracts were obtained by Soxhlet extraction with ethanol, samples were dried, and compounds were separated by column chromatography. Fluorescent fractions were classified apart from other fractions and characterized by Scanning electron microscopy (SEM), UV-Vis, Raman, FTIR and 1H NMR spectra. Additionally, we obtained functional nanomaterials (using silica nanoparticles). TD-DFT molecular calculations of the fluorescent components were carried out to compare their theoretical UV-Vis spectra to experimental results. Nine fractions were obtained by chromatography and five of them showed fluorescence. Fluorescence of extracts from Eysenhardtia polystachya is due to more than one component and we suggest that could be other hydrochalcones for which we present possible structures. This finding would help to dissipate questions about which component is responsible for fluorescence in extracts from the plant and in this way determinate the appropriate use for these fluorophores. Finally, the application and viability as a biosensor using pulmonary epithelium fibroblast cell culture IMR-90 was proved, and in the concentration used are non-toxic materials.

Green synthesis of Ag nanoflowers using Kalanchoe Daigremontiana extract for enhanced photocatalytic and antibacterial activities.

The synthesis and applications of anisotropic nanostructures have attracted much attention in the last decade. The nanoflower-type structures are one of the nanomaterials with anisotropic structures most investigated because of owing to high densities of edges, corners, and stepped atoms present on their nano-petals. Here, silver nanoparticles obtained by a one-step green synthesis method using extract from Kalanchoe Daigremontiana´s leaves are reported. To identify the compounds responsible for reduction of silver ions, the functional groups present in plant extract were investigated by UV-vis and FTIR. Ag nanoparticles were characterized by UV-vis, XPS, ζ-potential, XRD, and SEM-EDS. Different solvents were used to eliminate agglomeration of the silver nanoparticles. These solvents produced nanoflower-like morphology with abundant nano-petals. This is the first report of the synthesis of Ag nanoflowers formed by green synthesis method using Kalanchoe Daigremontiana extract. The synthesized Ag nanoflowers are faced center cubic structure in nature with a petal thickness approximately of 25 nm. Photocatalytic activity of the different Ag nanostructures was evaluated through the degradation of methylene blue, where the degradation time as low as 1 min is reported. Furthermore these green synthesized Ag nanoflowers were found to show high antibacterial activity against Gram-negative bacteria Escherichia coli and Gram-positive Staphylococcus aureus.

Encefalomielitis diseminada aguda posinfecciosa en un paciente con sospecha de infección por virus dengue / Postinfectious acute disseminated encephalomyelitis in a patient with suspected dengue virus infection

Introducción: La infección por virus dengue es considerada una de las arbovirosis de mayor prevalencia en los países tropicales. La encefalomielitis diseminada aguda es un trastorno inflamatorio desmielinizante y multifocal que afecta al sistema nervioso central, de inicio agudo y curso clínico monofásico. El proceso inflamatorio se encuentra mediado por mecanismos inmunológicos y su relación con infecciones por el virus dengue aún no se establece con claridad. Objetivo: Describir un caso clínico con manifestaciones del sistema nervioso central después de una probable infección por el virus dengue. Presentación del caso: Paciente femenina de 50 años, con antecedentes de hipertensión arterial controlada. Quince días después de un cuadro de fiebre de 4 días de duración, que posiblemente fue por una infección por el virus dengue, comienza con síntomas y signos de afectación neurológica caracterizadas por ligera irritabilidad, dificultad para la concentración en una actividad específica de la vida cotidiana. Progresivamente se nota dificultad motora en el hemicuerpo izquierdo además de encontrarse agitada y distraída, motivo por el cual se decide su ingreso hospitalario. Se realiza el diagnóstico a través de los hallazgos en el examen físico, los estudios positivos de resonancia magnética nuclear y el resultado positivo de la IgM de dengue en sangre. Tanto la evolución clínica como la respuesta al tratamiento con esteroides fueron favorables. Conclusiones: El evento ocurrido en este caso sugiere que los facultativos deben tener presente el diagnóstico de encefalomielitis diseminada aguda en pacientes que han tenido infección previa o alta sospecha de esta por el virus dengue(AU)

Introduction: Dengue virus infection is one of the most prevalent arboviruses in tropical countries. Acute disseminated encephalomyelitis is an inflammatory demyelinating multifocal disorder affecting the central nervous system. Its onset is acute and its clinical course monophasic. The inflammatory process is mediated by immunological mechanisms, and its relationship to dengue virus infections is still not clear. Objective: Describe a clinical case of central nervous system manifestations after probable dengue virus infection. Case presentation: Female 50-year-old patient with a history of controlled hypertension. Fifteen days after a 4-day fever episode, possibly due to dengue virus infection, the patient starts presenting neurological signs and symptoms, such as slight irritability and difficulty to concentrate on a specific activity of daily living. The patient notices progressive motor difficulty in her left hemibody and she feels agitated and distracted. It is therefore decided for her to be hospitalized. A diagnosis is made based on physical examination findings, positive nuclear magnetic resonance studies, and the positive result of the dengue IgM blood test. Both the patient's clinical evolution and her response to treatment with steroids were favorable. Conclusions: The event herein described suggests that physicians should consider the diagnosis of acute disseminated encephalomyelitis in patients with previous infection or high suspicion of infection with dengue virus(AU)

Stability Analysis of Anthocyanins Using Alcoholic Extracts from Black Carrot (Daucus Carota ssp. Sativus Var. Atrorubens Alef.).

Anthocyanins are used for food coloring due their low toxicity and health benefits. They are extracted from different sources, but black carrot has higher anthocyanin content compared with common fruits and vegetables. Here, we study alcoholic anthocyanin extracts from black carrot to enhance their stability. The objective of our research is to determine if microencapsulation with tetraethyl orthosilicate (TEOS) is a feasible option for preventing black carrot anthocyanin degradation. Extraction solvents were solutions of (1) ethanol/acetic acid and (2) ethanol/citric acid. Samples were purified through a resin column and microencapsulated using TEOS. Fourier Transformed Infrared Spectroscopy (FTIR) spectra of samples were obtained, and degradation studies were performed under different conditions of UV radiation, pH and temperature. Antioxidant activity was evaluated with radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging and electrochemical cupric reducing antioxidant capacity (CUPRAC). Color evaluation on food models were performed with CIE Lab at the beginning of experiments and after 25 days of storage. Results indicate that the more stable extracts against pH media changes are samples obtained with ethanol/acetic acid solution as extraction solvent. Extract purification through resin and TEOS microencapsulation had no significant effect on extract stability. In conclusion, although TEOS microencapsulation has proven to be effective for some dried materials from natural extracts in our previous research, we do not recommend its use for black carrot extracts considering our results in this particular case.

Auranofin-loaded nanoparticles as a new therapeutic tool to fight streptococcal infections.

Drug-loaded nanoparticles (NPs) can improve infection treatment by ensuring drug concentration at the right place within the therapeutic window. Poly(lactic-co-glycolic acid) (PLGA) NPs are able to enhance drug localization in target site and to sustainably release the entrapped molecule, reducing the secondary effects caused by systemic antibiotic administration. We have loaded auranofin, a gold compound traditionally used for treatment of rheumatoid arthritis, into PLGA NPs and their efficiency as antibacterial agent against two Gram-positive pathogens, Streptococcus pneumoniae and Streptococcus pyogenes was evaluated. Auranofin-PLGA NPs showed a strong bactericidal effect as cultures of multiresistant pneumococcal strains were practically sterilized after 6 h of treatment with such auranofin-NPs at 0.25 µM. Moreover, this potent bactericidal effect was also observed in S. pneumoniae and S. pyogenes biofilms, where the same concentration of auranofin-NPs was capable of decreasing the bacterial population about 4 logs more than free auranofin. These results were validated using a zebrafish embryo model demonstrating that treatment with auranofin loaded into NPs achieved a noticeable survival against pneumococcal infections. All these approaches displayed a clear superiority of loaded auranofin PLGA nanocarriers compared to free administration of the drug, which supports their potential application for the treatment of streptococcal infections.

Synthesis and functionalization of silica-based nanoparticles with fluorescent biocompounds extracted from Eysenhardtia polystachya for biological applications.

Several types of dyes or fluorophores are used for the detection of interactions between drug carriers and cells, within biomedicine field. However, many of them have a certain level of toxicity and instability affecting their biological properties. Different studies have demonstrated that nanoparticles (NPs) have interesting properties that could be used to stabilize diverse biomolecules, including dyes. Here, we report the synthesis of a novel nanosystem by the functionalization of silica NPs using biocompounds extracted from Mexican tree "Palo azul" (Eysenhardtia polystachya) and APTES as a coupling agent. Particle size, electrical properties, and morphology of the novel nanosystem were analyzed. The extracted biocompounds presented fluorescence which prevails over time, even after nanosystem formation and apparent cellular internalization. These were detected using MCF-7 cells visualized by confocal laser-scanning microscopy (CLSM), finding that the nanosystem was able to internalize into cells and act as a fluorescent biomarker. By this method, our novel nanosystem opens the possibilities to obtain sensitive data in a noninvasive manner for biological applications, such as early-stage cancer diagnosis, drug delivery, and pathogen detection.

Isolation and structural characterization of the milled wood lignin, dioxane lignin, and cellulolytic lignin preparations from brewer's spent grain.

The structure of the lignin from brewer's spent grain (BSG) has been studied in detail. Three different lignin preparations, the so-called "milled-wood" lignin (MWL), dioxane lignin (DL), and cellulolytic lignin (CEL), were isolated from BSG and then thoroughly characterized by pyrolysis GC/MS, 2D-NMR, and derivatization followed by reductive cleavage (DFRC). The data indicated that BSG lignin presents a predominance of guaiacyl units (syringyl/guaiacyl ratio of 0.4-0.5) with significant amounts of associated p-coumarates and ferulates. The flavone tricin was also present in the lignin from BSG, as also occurred in other grasses. 2D-NMR (HSQC) revealed that the main substructures present are ß-O-4' alkyl-aryl ethers (77-79%) followed by ß-5' phenylcoumarans (11-13%) and lower amounts of ß-ß' resinols (5-6%) and 5-5' dibenzodioxocins (3-5%). The results from 2D-NMR (HMBC) and DFRC indicated that p-coumarates are acylating the γ-carbon of lignin side chains and are mostly involved in condensed structures. DFRC analyses also indicated a minor degree of γ-acylation with acetate groups, which takes place preferentially on S lignin (6% of S units are acetylated) over G lignin (only 1% of G units are acetylated).

Effects of tetraethyl orthosilicate (TEOS) on the light and temperature stability of a pigment from Beta vulgaris and its potential food industry applications.

A novel, simple and inexpensive modification method using TEOS to increase the UV light, pH and temperature stability of a red-beet-pigment extracted from Beta vulgaris has been proposed. The effects on the molecular structure of betalains were studied by FTIR spectroscopy. The presence of betacyanin was verified by UV-Vis spectroscopy and its degradation in modified red-beet-pigment was evaluated and compared to the unmodified red-beet-pigment; performance improvements of 88.33%, 16.84% and 20.90% for UV light, pH and temperature stability were obtained, respectively,. Measurements of reducing sugars, phenol, and antioxidant contents were performed on unmodified and modified red-beet-pigment and losses of close to 21%, 54% and 36%, respectively, were found to be caused by the addition of TEOS. Polar diagrams of color by unmodified and modified red-beet-pigment in models of a beverage and of a yogurt were obtained and the color is preserved, although here is a small loss in the chromaticity parameter of the modified red-beet-pigment.

Antidiarrheal activity of 19-deoxyicetexone isolated from Salvia ballotiflora Benth in mice and rats.

The antidiarrheal properties of 19-deoxyicetexone, a diterpenoid isolated from Salvia ballotiflora were evaluated on castor oil-, arachidonic acid (AA)- and prostaglandin (PGE2)-induced diarrhea in rodent models. The structure of 19-deoxyicetexone was determined by X-ray crystallography, mass spectrometry (EI-MS), as well as ultraviolet (UV-Vis), infrared (FT-IR) and nuclear magnetic resonance (NMR) spectroscopies. This compound significantly and dose-dependently reduced frequency of stooling in castor oil-induced diarrhea, and at dose of 25 mg/kg it also inhibited diarrhea induced with AA, while it had no effect on PGE2-induced diarrhea. This compound at doses of 25 mg/kg also diminished castor oil-induced enteropooling and intestinal motility, and inhibited the contraction of the rats' ileum induced by carbachol chloride at a concentration of 100 µg/mL. 19-Deoxyicetexone did not present acute toxicity at doses of 625 mg/kg. Its antidiarrheal activity may be due to increased reabsorption of NaCl and water and inhibition of the release of prostaglandins, gastrointestinal motility and fluid accumulation in the intestinal tracts of rats. These findings suggest that 19-deoxyicetexone may be used in the treatment of diarrhea, although more studies must be carried out to confirm this.

Understanding pulp delignification by laccase-mediator systems through isolation and characterization of lignin-carbohydrate complexes.

The effects and mechanism of pulp delignification by laccases in the presence of redox mediators have been investigated on unbleached eucalyptus kraft pulp treated with laccases from Pycnoporus cinnabarinus (PcL) and Myceliophthora thermophila (MtL) and 1-hydroxybenzotriazole (HBT) and methyl syringate (MeS) as mediators, respectively. Determination of the corrected κ number in eucalyptus pulps after the enzymatic treatments revealed that the PcL-HBT system exhibited a more remarkable delignification effect than the MtL-MeS system. To obtain further insight, lignin-carbohydrate complexes were fractionated and subsequently characterized by nuclear magnetic resonance, thioacidolysis (followed by gas chromatography and size exclusion chromatography), and pyrolysis-gas chromatography-mass spectrometry (pyrolysis-GC-MS) analyses before and after the enzymatic treatments and their controls. We can conclude that the laccase-mediator treatments altered the lignin structures in such a way that more lignin was recovered in the xylan-lignin fractions, as shown by Klason lignin estimation, with smaller amounts of both syringyl (S) and guaiacyl (G) uncondensed units, as shown by thioacidolysis and gas chromatography, especially after the PcL-HBT treatment. The laccase-mediator treatment produced oxidation at Cα and cleavage of Cα and Cß bonds in pulp lignin, as shown by pyrolysis-GC-MS. The general mechanism of residual lignin degradation in the pulp by laccase-mediator treatments is discussed in light of the results obtained.

Structural characterization of lignin isolated from coconut (Cocos nucifera) coir fibers.

The structure of the isolated milled "wood" lignin from coconut coir has been characterized using different analytical methods, including Py-GC/MS, 2D NMR, DFRC, and thioacidolysis. The analyses demonstrated that it is a p-hydroxyphenyl-guaiacyl-syringyl (H-G-S) lignin, with a predominance of G units (S/G ratio 0.23) and considerable amounts of associated p-hydroxybenzoates. Two-dimensional NMR indicated that the main substructures present in this lignin include ß-O-4' alkyl aryl ethers followed by phenylcoumarans and resinols. Two-dimensional NMR spectra also indicated that coir lignin is partially acylated at the γ-carbon of the side chain with p-hydroxybenzoates and acetates. DFRC analysis showed that acetates preferentially acylate the γ-OH in S rather than in G units. Despite coir lignin's being highly enriched in G-units, thioacidolysis indicated that ß-ß' resinol structures are mostly derived from sinapyl alcohol. Finally, we find evidence that the flavone tricin is incorporated into the coconut coir lignin, as has been recently noted for various grasses.

Sugar recoveries from wheat straw following treatments with the fungus Irpex lacteus.

Irpex lacteus is a white-rot fungus capable of increasing sugar recovery from wheat straw; however, in order to incorporate biopretreatment in bioethanol production, some process specifications need to be optimized. With this objective, I. lacteus was grown on different liquid culture media for use as inoculums. Additionally, the effect of wheat straw particle size, moisture content, organic and inorganic supplementations, and mild alkali washing during solid-state fermentation (SSF) on sugar yield were investigated. Wheat thin stillage was the best medium for producing inoculums. Supplementation of wheat straw with 0.3mM Mn(II) during SSF resulted in glucose yields of 68% as compared to yields of 62% and 33% for cultures grown without supplementation or on untreated raw material, respectively after 21 days. Lignin loss, wheat straw digestibility, peroxidase activity, and fungal biomass were also correlated with sugar yields in the search for biopretreatment efficiency indicators.

Demonstration of laccase-based removal of lignin from wood and non-wood plant feedstocks.

The ability of Trametes villosa laccase, in conjuction with 1-hydroxybenzotriazole (HBT) as mediator and alkaline extraction, to remove lignin was demonstrated during treatment of wood (Eucalyptus globulus) and non-wood (Pennisetum purpureum) feedstocks. At 50 Ug(-1) laccase and 2.5% HBT concentration, 48% and 32% of the Eucalyptus and Pennisetum lignin were removed, respectively. Two-dimensional nuclear magnetic resonance of the feedstocks, swollen in dimethylsulfoxide-d(6), revealed the removal of p-hydroxyphenyl, guaiacyl and syringyl lignin units and aliphatic (mainly ß-O-4'-linked) side-chains of lignin, and a moderate removal of p-coumaric acid (present in Pennisetum) without a substantial change in polysaccharide cross-signals. The enzymatic pretreatment (at 25 Ug(-1)) of Eucalyptus and Pennisetum feedstocks increased the glucose (by 61% and 12% in 72 h) and ethanol (by 4 and 2 g L(-1) in 17 h) yields from both lignocellulosic materials, respectively, as compared to those without enzyme treatment.

New dye-sensitized solar cells obtained from extracted bracts of Bougainvillea glabra and spectabilis betalain pigments by different purification processes.

The performance of a new dye-sensitized solar cell (DSSC) based in a natural dye extracted from the Bougainvillea spectabilis' bracts, is reported. The performance of this solar cell was compared with cells prepared using extract of the Bougainvillea glabra and mixture of both extracts; in both cases the pigments were betalains, obtained from Reddish-purple extract. These dyes were purified to different extents and used for the construction of solar cells that were electrically characterized. The materials were characterized using FTIR and UV-Vis. Solar cells were assembled using TiO(2) thin film on indium tin oxide (ITO)-coated glass; a mesoporous film was sensitized with the Bougainvillea extracts. The obtained solar energy conversion efficiency was of 0.48% with a current density J(SC) of 2.29 mA/cm(2) using an irradiation of 100 mW/cm(2) at 25 °C.

Towards industrially-feasible delignification and pitch removal by treating paper pulp with Myceliophthora thermophila laccase and a phenolic mediator.

The ability of two natural phenols to act as mediators of the recombinant Myceliophthora thermophila laccase (MtL) in eucalypt-pulp delignification was investigated. After alkaline peroxide extraction, the properties of the enzymatically-treated pulps improved with respect to the control. The pulp brightness increased (3.1 points) after the enzymatic treatment with MtL alone, but the highest improvements were obtained after the MtL treatment using syringaldehyde (4.7 points) and especially methyl syringate (8.3 points) as mediators. Likewise, a decrease in kappa number up to 2.7 points was obtained after the MtL-methyl syringate treatment, followed by decreases of 1.4 and 0.9 points after the treatments with MtL-syringaldehyde and MtL alone, respectively. On the other hand, removal of the main lipophilic extractives present in eucalypt pulp was observed after the above laccase-mediator treatments. Finally, the doses of both MtL and methyl syringate were reduced, and results compatible with industrial implementation were obtained.

Highly acylated (acetylated and/or p-coumaroylated) native lignins from diverse herbaceous plants.

The structure of lignins isolated from the herbaceous plants sisal ( Agave sisalana), kenaf ( Hibiscus cannabinus), abaca ( Musa textilis) and curaua ( Ananas erectifolius) has been studied upon spectroscopic (2D-NMR) and chemical degradative (derivatization followed by reductive cleavage) methods. The analyses demonstrate that the structure of the lignins from these plants is highly remarkable, being extensively acylated at the gamma-carbon of the lignin side chain (up to 80% acylation) with acetate and/or p-coumarate groups and preferentially over syringyl units. Whereas the lignins from sisal and kenaf are gamma-acylated exclusively with acetate groups, the lignins from abaca and curaua are esterified with acetate and p-coumarate groups. The structures of all these highly acylated lignins are characterized by a very high syringyl/guaiacyl ratio, a large predominance of beta- O-4' linkages (up to 94% of all linkages), and a strikingly low proportion of traditional beta-beta' linkages, which indeed are completely absent in the lignins from abaca and curaua. The occurrence of beta-beta' homocoupling and cross-coupling products of sinapyl acetate in the lignins from sisal and kenaf indicates that sinapyl alcohol is acetylated at the monomer stage and that, therefore, sinapyl acetate should be considered as a real monolignol involved in the lignification reactions.