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Funder: Royal Society; Id: http://dx.doi.org/10.13039/501100000288, Funder: Winton Programme for the Physics of Sustainability, Conjugated polymers are an important class of chromophores for optoelectronic devices. Understanding and controlling their excited state properties, in particular, radiative and non‐radiative recombination processes are among the greatest challenges that must be overcome. We report the synthesis and characterization of a molecularly encapsulated naphthalene diimide‐based polymer, one of the most successfully used motifs, and explore its structural and optical properties. The molecular encapsulation enables a detailed understanding of the effect of interpolymer interactions. We reveal that the non‐encapsulated analogue P(NDI‐2OD‐T) undergoes aggregation enhanced emission; an effect that is suppressed upon encapsulation due to an increasing π‐interchain stacking distance. This suggests that decreasing π‐stacking distances may be an attractive method to enhance the radiative properties of conjugated polymers in contrast to the current paradigm where it is viewed as a source of optical quenching.

We recently introduced piezoelectric lithium niobate (LN) based transparent ultrasound transducers (TUT) as a new platform for developing multimodal optical, ultrasound, and photoacoustic imaging (PAI) systems. However, LN based TUT is limited in its signal-to-noise ratio due to material's low piezoelectricity ( $d_{33}$ ). In this letter, we report, for the first time, a 0.2-mm-thick transparent lead magnesium niobate-lead titanate (PMN-PT) based TUT (PMN-PT-TUT) for ultrasound and photoacoustic applications and compared its performance with a 0.25-mm-thick transparent LN based TUT (LN-TUT). To improve the ultrasound energy transmission efficiency, TUTs were fabricated with a two-matching-layer design. This resulted in a dual frequency response with center frequencies of 7.8 MHz/13.2 MHz and corresponding bandwidths of 28.2%/66.67% for PMN-PT-TUT, as well as center frequencies of 7.2 MHz/11.8 MHz and bandwidths of 36.1%/62.7% for LN-TUT. The optical transmission rate of PMN-PT-TUTs and LN-TUTs are measured as $\sim$ 73 and $\sim$ 91%, respectively, at 532 nm optical wavelength. The PMN-PT-TUT exhibited higher sensitivity compared to LN-TUT with a nearly threefold higher pulse echo amplitude and more than twofold higher photoacoustic amplitude. Furthermore, optical resolution photoacoustic microscopy experiments on phantom targets demonstrated lateral resolutions of 7 and 5.1 $\mu$ m and axial resolutions of 285.6 and 375.9 $\mu$ m for PMN-PT-TUT and LN-TUT, respectively. These results indicated that PMN-PT is a viable alternative to LN for developing TUT based multimodal ultrasound and PAI systems.

Efficient charge photogeneration in conjugated polymers typically requires the presence of a second component to act as electron acceptor. Here, we report a novel low band-gap conjugated polymer with a donor/orthogonal acceptor motif: poly-2,6-(4,4-dihexadecyl-4H-cyclopenta [2,1-b:3,4-b′]dithiophene)-alt-2,6-spiro [cyclopenta[2,1-b:3,4-b′]dithiophene-4,9′-fluorene]-2′,7′-dicarbonitrile, referred to as PCPDT-sFCN. The role of the orthogonal acceptor is to spatially isolate the LUMO from the HOMO, allowing for negligible exchange energy between electrons in these orbitals and minimising the energy gap between singlet and triplet charge transfer states. We employ ultrafast and microsecond transient absorption spectroscopy to demonstrate that, even in the absence of a separate electron acceptor, PCPDT-sFCN shows efficient charge photogeneration in both pristine solution and film. This efficient charge generation is a result of an isoenergetic singlet/triplet charge transfer state equilibrium acting as a reservoir for charge carrier formation. Furthermore, clear evidence of enhanced triplet populations, which form in less than 1 ps, is observed. Using group theory, we show that this ultrafast triplet formation is due to highly efficient, quantum mechanically allowed intersystem crossing between the bright, initially photoexcited local singlet state and the triplet charge transfer state. Remarkably, the free charges that form via the charge transfer state are extraordinarily long-lived with millisecond lifetimes, possibly due to the stabilisation imparted by the spatial separation of PCPDT-sFCN's donor and orthogonal acceptor motifs. The efficient generation of long-lived charge carriers in a pristine polymer paves the way for single-material applications such as organic photovoltaics and photodetectors., The spatial separation of PCPDT-sFCN's donor and orthogonal acceptor motifs allows efficient photogeneration of extraordinarily long-lived charge carriers in the pristine polymer, providing an important step towards single-material optoelectronics.

Intermolecular interactions play a fundamental role on the performance of conjugated materials in organic electronic devices, as they heavily influence their optoelectronic properties. Synthetic control over the solid state properties of organic optoelectronic materials is crucial to access real life applications. Perylene diimides (PDIs) are one of the most highly studied classes of organic fluorescent dyes. In the solid state, π-π stacking suppresses their emission, limiting their use in a variety of applications. Here, we report the synthesis of a novel PDI dye that is encapsulated by four alkylene straps. X-ray crystallography indicates that intermolecular π-π stacking is completely suppressed in the crystalline state. This is further validated by the photophysical properties of the dye in both solution and solid state and supported by theoretical calculations. However, we find that the introduction of the encapsulating "arms" results in the creation of charge-transfer states which modify the excited state properties. This article demonstrates that molecular encapsulation can be used as a powerful tool to tune intermolecular interactions and thereby gain an extra level of control over the solid state properties of organic optoelectronic materials.

In recent years, common bean in Brazil has become interesting to precede the growing of off-season cotton due to its short cycle. This study was carried out in a Red Latosol in Chapadão do Sul, MS and aimed to select among the attributes of the evaluated soils, those with the best linear and spatial correlation, to explain the variability of grain yield of common bean in the soil layers of 0 - 0.10 m (layer 1) and 0.10 - 0.20 m (layer 2), sampled in a grid of 121 georeferenced points (spacing of 5 meters between points). The soil chemical attributes were determined: pH, carbon (C), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), aluminum (Al), and the sum of bases (SB). The analysis of these data was carried out using statistical and geostatistical techniques that made it possible to verify that for the grain yield of common bean, the multiple regression analysis indicates that approximately 20% of its variation is attributed to the variation in the chemical attributes of the soil presented in the present study. The chemical attributes pH1, pH2, C1, Ca1, Ca2, Mg1a, Mg2, Al2, SB1, and SB2 have spatial dependence classified mostly as moderate. Both linearly and spatially, C1 stood out as a potential indicator of common bean grain yield when grown under no-tillage.

Objective and Impact StatementSimultaneous imaging of ultrasound and optical contrasts can help map structural, functional and molecular biomarkers inside living subjects with high spatial resolution. There is a need to develop a platform to facilitate this multimodal imaging capability to improve diagnostic sensitivity and specificity.IntroductionCurrently, combining ultrasound, photoacoustic and optical imaging modalities is challenging because con-ventional ultrasound transducer arrays are optically opaque. As a result, complex geometries are used to co-align both optical and ultrasound waves in the same field of view.MethodsOne elegant solution is to make the ultrasound transducer transparent to light. Here, we demonstrate a novel transparent ultrasound transducer (TUT) liner array fabricated using a transparent lithium niobate piezoelectric material for real-time multimodal imaging.ResultsThe TUT array consisted of 64 elements and centered at ∼ 6 MHz frequency. We demonstrate a quad-mode ultrasound, Doppler ultrasound, photoacoustic and fluorescence imaging in real-time using the TUT array directly coupled to the tissue mimicking phantoms.ConclusionThe TUT array successfully showed a multimodal imaging capability, and has potential applications in diagnosing cancer, neuro and vascular diseases, including image-guided endoscopy and wearable imaging.

Porous silicon (PSi) is a promising material for future integrated nanophotonics when coupled with guest emitters, still facing challenges in terms of homogenous distribution and nanometric thickness of the emitter coating within the silicon nanostructure. Herein, it is shown that the nanopore surface of a porous silicon oxide (PSiO2) microcavity (MC) can be conformally coated with a uniform nm-thick layer of a cationic light-emitting polyelectrolyte, e.g., poly(allylamine hydrochloride) labeled with Rhodamine B (PAH-RhoB), leveraging the self-tuned electrostatic interaction of the positively-charged PAH-RhoB polymer and negatively-charged PSiO2 surface. It is found that the emission of PAH-RhoB in the PSiO2 MC is enhanced (≈2.5×) and narrowed (≈30×) at the resonant wavelength, compared with that of PAH-RhoB in a non-resonant PSiO2 reference structure. The time-resolved photoluminescence analysis highlights a shortening (≈20%) of the PAH-RhoB emission lifetime in the PSiO2 MC at the resonance versus off-resonance wavelengths, and with respect to the reference structure, thereby proving a significant variation of the radiative decay rate. Remarkably, an experimental Purcell factor Fp= 2.82 is achieved. This is further confirmed by the enhancement of the photoluminescence quantum yield of the PAH-RhoB in the PSiO2 MC with respect to the reference structure. Application of the electrostatic nanoassembling approach to other emitting dyes, nanomaterials, and nanophotonic systems is envisaged.

The aggregation-induced emission (AIE) phenomenon provides a new direction for the development of organic light-emitting devices. Here, we present a new class of emitters based on 4,4-difluoro-4-bora-3 a ,4 a -diaza- s -indacene (BODIPY), functionalized at different positions with tetraphenylethylene (TPE), which is one of the most famous AIE luminogens. Thanks to this modification, we were able to tune the photoluminescence of the BODIPY moiety from the green to the near-infrared (NIR) spectral range and achieve PL efficiencies of ~50% in the solid state. Remarkably, we observed an enhancement of the AIE and up to ~100% photoluminescence efficiencies by blending the TPE-substituted BODIPY fluorophores with a poly[(9,9-di- n -octylfluorene-2,7-diyl)- alt -(benzo[2,1,3]thiadiazol-4,7-diyl)] (F8BT) matrix. By incorporating these blends in organic light-emitting diodes (OLEDs), we obtained electroluminescence peaked in the range 650–700 nm with up to 1.8% external quantum efficiency and ~2 mW/cm2 radiance, a remarkable result for red/NIR emitting and solution-processed OLEDs.

Conjugated polymers with intense solid-state emission are vital for the development of next-generation optoelectronic devices. In particular, it remains extremely challenging to construct π-conjugated systems that emit in the red region of the electromagnetic spectrum and also retain their optical properties and intense photoluminescence in the solid state. In this article we report the synthesis and characterization of three novel diketopyrrolopyrrole-based conjugated polymers, with systematic variation of the covalent encapsulation density. Through control of the distance and density of encapsulation, our red-emitting polymers demonstrate that aggregation-caused quenching can be mostly eliminated, culminating in the most efficient solid-state photoluminescence from red conjugated polymers to date.

This work reports the first observation of circularly polarized electroluminescence (CPEL) in thin films of self-organized oligothiophenes. Four new 1,4-phenylene and 9H-carbazole-based oligothiophenes were ad hoc designed to ensure efficient spontaneous formation of chiral supramolecular order. They were easily synthesized and their chiroptical properties in thin films were measured. Circularly polarized luminescence (CPL) spectra revealed glum in the order of 10−2 on a wide wavelengths range, originating from their self-organized chiral supramolecular organization. These molecules have reasonable properties as organic semiconductors and for this reason they can constitute the active layer of circularly-polarized organic light-emitting diodes (CP-OLEDs). Thus, we could investigate directly their electroluminescence (EL) and CPEL, without resorting to blends, but rather in a simple multilayer device with basic architecture. This is the first example of a CP-OLED with active layer made only of a small organic compound.

In this paper we experimentally demonstrate, for the first time, staggered carrier-less amplitude and phase (sCAP) modulation for visible light communication systems based on polymer light-emitting diodes emitting at ~639 nm. The key advantage offered by sCAP in comparison to conventional multiband CAP is its full use of the available spectrum. In this work, we compare sCAP, which utilises four orthogonal filters to generate the signal, with a conventional 4-band multi-CAP system and on-off keying (OOK). We transmit each modulation format with equal energy and present a record un-coded transmission speed of ~6 Mb/s. This represents gains of 25% and 65% over the achievable rate using 4-CAP and OOK, respectively., 6 pages, 9 figures, IEEE ICC 2019 conference

A dianiline derivative of a symmetric donor-acceptor-donor diketopyrrolopyrrole-based dye is employed for the two-sided covalent functionalization of liquid exfoliated few layers graphene flakes, through a direct arylation reaction. The resulting nanohybrid features the properties of a polymeric species, being solution-processed into homogeneous thin films, featuring a pronounced red-shift of the main absorption band with respect to the model dye unit and energy levels comparable to those of common diketopyrrolopyrrole-based polymers. A good electrical conductivity and the absence of radical signals generated after intense white light illumination, as probed through electron paramagnetic resonance, suggest a possible future application of this composite material in the field of photoprotective, antistatic layers with tunable colors.

This paper investigates the use of organic polymer light emitting diodes (PLEDs) for the use in visible light communications (VLC). We prepared blue and green emitting PLEDs using commercial light-emitting polymers, and then characterised the device emission (spectrum and power), and extracted their circuit parameters for their electrical equivalent model for driving with small signals. In addition, we characterised the bandwidth ( $\boldsymbol{B_{mod}}$ ) of the devices over a period of continuous driving (∼ 4 h) and found that for the blue PLEDs the $\boldsymbol{B_{mod}}$ decreased from an initial 750 kHz to a steady state of ∼250 kHz. The green-emitting devices were found to benefit from an extended $\boldsymbol{B_{mod}}$ of ∼1.5 MHz at the beginning of the test, which then stabilised to ∼850 kHz. Furthermore, with the addition of a first order RC filter we show that, the steady state $\boldsymbol{B_{mod}}$ of the blue PLED cane be increased by a factor of ∼3, thus allowing > 1 Mbps non-return to zero on-off keying (NRZ OOK) data transmission in a complete VLC system.

The mechanism of light therapy is called phototherapy [3, 4]. It requires absorption of a specific wavelength by a light-absorbing molecule (chromophore), which can be produced and synthesized endogenously or applied exogenously to the receptor in cell tissues [3, 9, 12]. Irradiation in the photoreceptor generates a cascade of responses from the cells that leads to modulation of the cell function, proliferation, and repair of damaged cells [3, 9, 12]. The term that describes this “potentiation/cell function modulation” process is called photobiomodulation [3, 4, 9, 12] (Figs.109.1, 109.2, 109.3, and 109.4).

We take advantage of a recent breakthrough in the synthesis of α,β-unfunctionalised 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) moieties, which we symmetrically conjugate with oligothienyls in an unexpectedly stable form, and produce a “metal-free” A-D-A (acceptor-donor-acceptor) oligomer emitting in the near-infrared (NIR) thanks to delocalisation of the BODIPY low-lying lowest unoccupied molecular orbital (LUMO) over the oligothienyl moieties, as confirmed by density functional theory (DFT). We are able to retain a PL efficiency of 20% in the solid state (vs. 30% in dilute solutions) by incorporating such a dye in a wider gap polyfluorene matrix and demonstrate organic light-emitting diodes (OLEDs) emitting at 720 nm. We achieve external quantum efficiencies (EQEs) up to 1.1%, the highest value achieved so far by a “metal-free” NIR-OLED not intentionally benefitting from triplet-triplet annihilation. Our work demonstrates for the first time the promise of A-D-A type dyes for NIR OLEDs applications thereby paving the way for further optimisation.

© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.A series of new near-infrared (NIR) emitting copolymers, based on a low band gap 6-(2-butyloctyl)-4,8-di(thiophen-2-yl)-[1,2,3]triazolo[4',5':4,5]benzo[1,2-c]-[1,2,5]thiadiazole (TBTTT) fluorophore copolymerized into a high band gap poly[3,3'-ditetradecyl-2,2'-bithiophene-5,5'-diyl-alt-5-(2-ethylhexyl)-4H-thieno[3,4-c]pyrrole-4,6(5H)-dione-1,3-diyl] (P2TTPD) host backbone, for polymer light-emitting diode (PLED) applications is reported. PLEDs fabricated from the host polymer (P2TTPD-0) show external quantum efficiencies (EQEs) up to 0.49% at 690 nm, with turn-on voltage (Von) at only 2.4 V. By incorporating the TBTTT segments into the host polymer backbone, pure NIR emission peaking at ca. 900 nm is obtained with Von remaining below 5 V. This work demonstrates that such a low Von can be attributed to efficient intrachain energy and/or charge transfer to the TBTTT sites. When the NIR emitting copolymer (P2TTPD-10) is blended with P2TTPD-0, the TBTTT are confined to well-separated polymer chains. As a result, the EQE from the blend is lower and the Von higher than that obtained from the pure copolymer (P2TTPD-1.0) with equal content of TBTTT. An analogous copolymer (P4T-1.0), consisting of poly[3,3'-ditetradecyl-2,2':5',2'':5'',2'''-quaterthiophene-5,5'''-diyl] (P4T) as the host and 1% TBTTT as the NIR emitter, further demonstrates that pure NIR emission can be obtained only through optimized molecular orbital energy levels, as in P2TTPD-1.0, which minimizes chances for either charge trapping or exciton splitting.

In this past decade, new therapeutic approaches based on the use of rituximab, high-dose cytosine-arabinoside, and autologous stem cell transplantation (ASCT) have changed the paradigm of mantle cell lymphoma (MCL) treatment, significantly improving the quality and duration of response and

The widespread application of quantum dots greatly profits from their broad absorption band. However, the variable nature of excitations within these bands is expected to result in undesired excitation energy dependence of steady state emission properties. We demonstrate the different role played by hot and cold carrier trapping in determining fluorescence quantum yields. Our analysis relates the energetic parameters with the available knowledge on the dynamics of charge trapping. It turns out that detrapping processes play a pivotal role in determining steady state emission properties. We studied excitation dependent photoluminescence quantum yields (PLQY) in different CdSe/CdxZn1-xS (x = 0, 0.5, and 1) quantum dots to identify best performing heterostructures in terms of shell thickness and composition. Our rationalization of the observed behavior is focused on the modulation of trapping and detrapping rates. The combination of experimental results and PLQY kinetics modeling reveals the need to consider hot-carrier trapping, supporting recent dynamics observations. This work provides a deeper insight into the trapping process in quantum dots, relating its energetics and dynamics.

We present the synthesis of a novel diphenylanthracene (DPA) based semiconducting polymer. The polymer is solubilised by alkoxy groups attached directly to a DPA monomer, meaning the choice of co-monomer is not limited to exclusively highly solubilising moieties. Interestingly, the polymer shows a red-shifted elecroluminescence maximum (510 nm) when compared to its photoluminescence maximum (450 nm) which we attribute to excimer formation. The novel polymer was utilised as a host for a covalently-linked platinum(ii) complexed porphyrin dopant. Emission from these polymers was observed in the NIR and again showed almost a 100 nm red shift from photoluminescence to electroluminescence. This work demonstrates that utilising highly aggregating host materials is an effective tool for inducing red-shifted emission in OLEDs.

We report our investigations of the photophysical properties of a so-called “donor-acceptor” (D-A) electroluminescent polymer incorporating N-alkyl-4,7-di(thien-2-yl)-2,1,3-benzothiadiazole-5,6-dicarboxylic imide (DI) as the electron acceptor and benzo[1,2-b:4,5-b′]dithiophene (BDT) acceptor units. Polymer light-emitting diodes (PLEDs) based on this copolymer give the best efficiency (external quantum efficiency EQE∼0.04%) and show a pure near-infrared (NIR) electroluminescence (EL) with a peak at 870 nm.

RESUMO O presente trabalho foi desenvolvido com o objetivo de avaliar a produção de biomassa, crescimento micelial e a colonização do substrato palha de arroz por Pleurotus ostreatus e Pleurotus ostreatoroseus, sob o efeito da adição de serragem de couro curtida ao tanino vegetal. O experimento 1 constituiu-se na formulação de meios de cultura, à base de palha de arroz adicionada de serragem de couro, nas concentrações 0, 5, 10, 15, 20, 25 e 30%. Discos de micélio de P. ostreatus (BF24) e P. ostreatoroseus (POR01/06) foram transferidos para o centro de placas contendo meios previamente preparados. Eles foram incubados a 28º C. No segundo experimento, o substrato palha de arroz foi submetido as mesmas condições experimentais acima descritas. O substrato inoculado com as duas cepas foi acondicionado em tubos de ensaio e incubado a 28º C. A biomassa fúngica foi avaliada pela diferença de massa seca e massa úmida, enquanto que para o crescimento do micélio realizaram-se mensurações em períodos pré-determinados até a completa colonização do meio ou do substrato. Verificou-se que os tratamentos com adição de 5, 15 e 25% e 15% deste suplemento para P. ostreatus proporcionaram redução da biomassa e do crescimento micelial, respectivamente. Na fase de miceliação o acréscimo de 5% deste suplemento a palha de arroz apresentou efeito positivo para o desenvolvimento de P. ostreatus.

The shell thickness and composition of CdSe–CdxZn1–xS core–shell quantum dots (QDs) are defining parameters for the efficiency of such materials as light emitters. In this work we present a detailed study into the optical absorption and fluorescence properties of CdSe–CdS, CdSe–Cd0.5Zn0.5S, and CdSe–ZnS QDs as a function of shell thickness. Moreover, the single-exciton recombination dynamics of these systems are analyzed by means of a time-correlated single-photon counting technique and directly related to the specific core–shell interfaces of the various QDs studied using a phenomenological kinetic model. The findings from this model highlight the strong role of the core–shell interface on both steady state photoluminescence and exciton recombination dynamics in these systems.

The arginine dihydrolase pathway in Giardia intestinalis produces energy via the carbamate kinase (CBK, ATP:carbamate phosphotransferase, EC 2.7.2.2) reaction. Characterisation of the CBK gene from the Portland 1 strain indicated that it is located on either chromosome 3 or 4, does not appear to contain introns and is expressed in both the trophozoite and early cyst stages. Heterologous expression of CBK in Escherichia coli, using the pQE-30 expression system (QIAGEN), enabled a one-step purification of the recombinant enzyme via affinity chromatography. The expressed protein was identified by enzyme assay and mass spectrometry. The native and recombinant forms of the enzyme have similar physical properties and the recombinant enzyme appears to be active as the homodimer.

Minotto, L., Ko, G.-A., Edwards, M. R., and Bagnara, A. S. 1998.Trichomonas vaginalis: Expression and characterisation of recombinantS-adenosylhomocysteinase.Experimental Parasitology90, 175–180. The gene encodingS-adenosylhomocysteinase activity (S-adenosylhomocysteine hydrolase, SAHH; EC 3.3.1.1) inTrichomonas vaginalishas been expressed inEscherichia colito facilitate the characterisation of the enzyme. Expression of this gene using the pQE-30 (6xHis N-terminal tag) expression system (QIAGEN) has enabled the one-step purification of 6 mg of active recombinant enzyme from a 100-ml bacterial culture by affinity chromatography using a nickel-NTA matrix. The recombinant enzyme has a molecular weight of approximately 56,000 and identification of tryptic peptides by matrix-assisted laser desorption ionisation (MALDI) mass spectrometry has shown that the purified recombinant protein is identical in primary structure to the predicted sequence. The presence of the N-terminal 6xHis tag in the recombinant enzyme did not appear to affect its kinetic and other properties, which are similar to those exhibited by the “native” enzyme present in cell-free extracts ofT. vaginalis.These properties include a similar apparentKmfor adenosine (20–25 μM for the recombinant and 5–10 μM for the native enzymes, respectively) and similar inhibition/inactivation patterns exhibited by adenosine analogues such as arabinosyl adenine (ara-A).

The objective of this study was to evaluate soybean and Brachiaria forage yields, under a crop-livestock integration system, in terms of increasing covering herbicide and potassium rates. The experiment was carried out in a randomized complete blocks design, in a split-split-plot scheme, with three replications. The treatments were: cultivars (CD 216 and VMax), for plots; herbicide rates (0 g ha -1 , 0.24 g ha -1 ; and 0.96 g ha -1 of haloxyfop-methyl), for split-plots; and potassium doses (30 kg ha -1 and 60 kg ha -1 of K 2 O), for split-split-plots. VMax presented the highest number of pods per plant, while CD 216 presented the largest number of grains per pods. There was interaction among cultivars and herbicide doses, concerning the one hundred grains mass. For the split-plot, in comparison with VMax, CD 216 showed a higher one hundred grains mass rate. T here were no significant levels of herbicide and K for soybean yield under crop-livestock integration. However, the highest CD 216 and VMax yield rates were obtained at 0 g i.a. ha -1 and 0.96 g i.a. ha -1 of the herbicide and 60 kg ha -1 and 30 kg ha -1 of K 2 O. The K doses which resulted in a higher dry biomass yield rate for Brachiaria brizantha were 30 kg ha -1 of K 2 O, in consortium with the CD 216 cultivar, and 60 kg ha -1 of K 2 O, in consortium with VMax. KEY-WORDS: Brachiaria brizantha ; Glycine max ; herbicides; intercropping; haloxyfop-methyl.

While several studies have been conducted on the antioxidant properties of the beta-amino acid taurine, these studies all used concentrations lower than what is found physiologically. This study investigates the scavenging and antioxidant properties of physiological taurine concentrations against different reactive species. No reactivity between taurine and hydrogen peroxide was found; however, taurine exhibited significant scavenging potential against peroxyl radical, nitric oxide, and superoxide donors. This study also evaluated if taurine was able to minimize the in vitro CuZn-superoxide dismutase damage (SOD) induced by peroxynitrite. Taurine prevented both the formation of nitrotyrosine adducts and the decrease in SOD activity caused by peroxynitrite. In addition, taurine prevented the ex vivo damage caused by tert-butyl hydroperoxide in rat liver slices. These experimental data show that taurine, at different physiological concentrations efficiently scavenges many reactive oxygen and nitrogen species. This finding supports the hypothesis that the antioxidant properties of taurine may be critical for the maintenance of cellular functions, and it suggests a more important function of taurine that requires further investigation.

O objetivo deste trabalho foi avaliar a produtividade, eficiência biológica, massa fresca, composição centesimal dos cogumelos Pleurotus ostreatus (BF24) e Pleurotus sajor-caju (PSC96/03 e PSC01/06) produzidos no substrato capim-elefante (Pennisetum purpureum) pasteurizado e a relação Carbono/Nitrogênio inicial e final do substrato. O substrato seco e particulado a 2 cm foi umedecido por 24 horas e pasteurizado a 100 ºC durante 30 minutos. Adicionaram-se 3% de inóculo de cada linhagem, sendo acondicionado em embalagens de polipropileno com 1 kg cada uma. Os substratos foram incubados a 26 ºC e na fase de frutificação a 23±3 ºC e umidade relativa de 75% a 90%. Na linhagem BF24 observou-se maior massa fresca (281,19g), eficiência biológica (112,46%) e produtividade (28,11%). O substrato com relação Carbono:Nitrogênio inicial de 162:1 foi o de menor relação (68:1) após o cultivo do P. sajor-caju (PSC01/06). A linhagem PSC96/03 proporcionou maior teor de proteína em relação às demais, tendo a BF24 maior teor de lipídios. Quanto ao teor de carboidratos e cinzas, nas diferentes espécies e linhagens não houve diferenças significativas; já para a quantidade de fibras, as linhagens BF24 e PSC01/06 foram similares, porém superiores a PSC96/03. As duas espécies de Pleurotus podem ser cultivadas em capim-elefante pasteurizado, suprimindo o processo de compostagem. The objective of this work was to evaluate the productivity, biological efficiency, fresh matter, and centesimal composition of mushroom Pleurotus ostreatus (BF24) and Pleurotus sajor-caju (PSC96/03 and PSC01/06) grown in pasteurized elephant grass substrate (Pennisetum purpureum). It was also assessed the initial and final Carbon/Nitrogen ratio. The dried 2-cm-particulate substrate was moist for 24 hours and pasteurized at 100ºC during 30 minutes. Then, it was added 3% of inoculum of each strain. The substrate was placed into 1-kg polypropylene bags. The bags were incubated at 26ºC and relative humidity of 75 to 90%. In the fructification phase they were incubated at 23±3ºC. The strain BF24 had the highest fresh matter (281.19g), biological efficiency (112.46%) and productivity (28.11%). The substrate having initial Carbon/Nitrogen ratio of 162:1 showed the lowest final ratio (68:1), after P. sajor-caju (PSC01/06) cultivation. The strain PSC96/03 showed higher protein content than the others, and BF24 had the highest lipid content. There were no significant differences for carbohydrate and ash contents for the different species and strains. The strains BF24 and PSC01/06 had similar fiber amount, but higher than PSC96/03. The two species of Pleurotus can be cultivated in pasteurized elephant grass, supressing the composting process.