Role of Intragap States in Sensitized Sb-Doped Tin Oxide Photoanodes for Solar Fuels Production.

In view of developing photoelectrosynthetic cells which are able to store solar energy in chemical bonds, water splitting is usually the reaction of choice when targeting hydrogen production. However, alternative approaches can be considered, aimed at substituting the anodic reaction of water oxidation with more commercially capitalizable oxidations. Among them, the production of bromine from bromide ions was investigated long back in the 1980s by Texas Instruments.

Electrocatalytic Poly(3,4-ethylenedioxythiophene) for Electrochemical Conversion of 5-Hydroxymethylfurfural.

This study investigates the utilization of the conductive polymer poly(3,4-ethylenedioxythiophene) (PEDOT) as a catalytic material for the 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-mediated oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA). PEDOT films doped with different counterions were electrodeposited on graphite foil. In particular, the mobile anion perchlorate and the polymeric ionomers polystyrenesulfonate, Nafion, and Aquivion were used.

N-acetylcysteine absorption and its potential dual effect improve fitness and fruit yield in Xylella fastidiosa infected plants.

Background: Xylella fastidiosa is a multi-host bacterium that can be detected in hundreds of plant species including several crops. Diseases caused by X. fastidiosa are considered a threat to global food production.

Particle films improve photosynthesis of citrus trees under excess irradiance by reducing leaf temperature.

High irradiance and increased air temperature during extreme weather conditions affect tree crops and impact the yield and quality of fruits. Moreover, flowering and fruit set of Citrus are likely impaired by UV radiation and/or reduced carbon assimilation, which increase reactive oxygen species production and damage the leaf photosynthetic apparatus. Particle coating films sprayed on leaves have been offered as a way to minimize crop losses due to the climate change scenario, even though the extent of leaf protection is not characterized.

Glyphosate excessive use chronically disrupts the shikimate pathway and can affect photosynthesis and yield in citrus trees.

Glyphosate excessive use is reported in Brazilian citrus orchards, whereas there is speculation about its consequences and the published studies are contradictory and inconclusive. This study aimed to describe the possible harmful effects by simulating glyphosate drift directly to the leaves of ∼4-yr-old citrus plants. As major results, glyphosate doses >360 g ae ha increased the shikimate accumulation in leaves (up to 2.

Electrodeposited PEDOT/Nafion as Catalytic Counter Electrodes for Cobalt and Copper Bipyridyl Redox Mediators in Dye-Sensitized Solar Cells.

PEDOT-based counter electrodes for dye-sensitized solar cells (DSSCs) are generally prepared by electrodeposition, which produces polymer films endowed with the best electrocatalytic properties. This translates in fast regeneration of the redox mediator, which allows the solar cell to sustain efficient photoconversion. The sustainable fabrication of DSSCs must consider the scaling up of the entire process, and when possible, it should avoid the use of large amounts of hazardous and/or inflammable chemicals, such as organic solvents for instance.

Visible Light Reductive Photocatalysis of Azo-Dyes with n-n Junctions Based on Chemically Deposited CdS.

New composite photocatalysts have been obtained by chemical bath deposition of CdS on top of either nanostructured crystalline ZrO or TiO films previously deposited on conductive glass FTO. Their morphological, photoelectrochemical and photochemical properties have been investigated and compared. Time resolved spectroscopic, techniques show that in FTO/TiO/CdS films the radiative recombination of charges, separated by visible illumination of CdS, is faster than in FTO/ZrO/CdS, evidencing that carrier dynamics in the two systems is different.

Effects of Deficit Irrigation and Huanglongbing on Sweet Orange Trees.

This study addresses the interactive effects of deficit irrigation and huanglongbing (HLB) infection on the physiological, biochemical, and oxidative stress responses of sweet orange trees. We sought to answer: (i) What are the causes for the reduction in water uptake in HLB infected plants? (ii) Is the water status of plants negatively affected by HLB infection? (iii) What are the key physiological traits impaired in HLB-infected plants? and (iv) What conditions can mitigate both disease severity and physiological/biochemical impairments in HLB-infected plants? Two water management treatments were applied for 11 weeks to 1-year-old-trees that were either healthy (HLB-) or infected with HLB (+) and grown in 12-L pots. Half of the trees were fully irrigated (FI) to saturation, whereas half were deficit-irrigated (DI) using 40% of the water required to saturate the substrate.

Emphysematous pyelonephritis caused by C. glabrata.

Emphysematous pyelonephritis (EPN) is a rare acute necrotizing infection of the kidney and surrounding tissues, with gas in the renal parenchyma, collecting system or perirenal tissue. The bacterial etiology predominates; mainly Gram-negative bacilli; Candida spp. and C.

Photoelectrochemical hydrogen evolution using CdTeS quantum dots as sensitizers on NiO photocathodes.

The design of active photocathodes for the hydrogen evolution reaction (HER) is a crucial step in the development of dye-sensitized photoelectrochemical cells (DS-PECs) aimed at solar-assisted water splitting. In the present work, we report on the use of orange CdTexS1-x quantum dots (QDs) with an average diameter of ca. 3.

Biomass partitioning and photosynthesis in the quest for nitrogen- use efficiency for citrus tree species.

Optimizing the use of nitrogen (N) for food production is a major challenge in agricultural systems. The transformation of N into crop production results from intricate pathways, depending on plants, as well as the environment and fertilization regimes, which affect the N-use efficiency (NUE) of plants. In this context, lemon trees [Citrus limon (L.

Coffee seedlings growth under varied NO:NH ratio: Consequences for nitrogen metabolism, amino acids profile, and regulation of plasma membrane H-ATPase.

Root plasma membrane H-ATPase electrochemical equilibrium for optimum coffee plant growth can be modulated by specific ammonium:nitrate (NO:NH) ratio supply. This study aimed to evaluate the coffee seedlings responses to varying ammonium:nitrate (NO:NH) ratio and to depict how much NO and NH plants can use in terms of growth, nitrogen metabolism, amino acids profile and regulation of root plasma membrane H-ATPase. Coffee plants were grown in nutrient solution with the following NO:NH ratios (%): 100:0; 87.

Zinc phthalocyanines as light harvesters for SnO-based solar cells: a case study.

SnO nanoparticles have been synthesized and used as electron transport material (ETM) in dye sensitized solar cells (DSSCs), featuring two peripherally substituted push-pull zinc phthalocyanines (ZnPcs) bearing electron donating diphenylamine substituents and carboxylic acid anchoring groups as light harvesters. These complexes were designed on the base of previous computational studies suggesting that the integration of secondary amines as donor groups in the structure of unsymmetrical ZnPcs might enhance photovoltaics performances of DSSCs. In the case of TiO-based devices, this hypothesis has been recently questioned by experimental results.

Recombination and regeneration dynamics in FeNHC(ii)-sensitized solar cells.

Recombination and regeneration dynamics in Fe-NHC-sensitized DSSCs revealed incomplete injection and the detrimental effect of photoinjected electron recapture by the I-form of the redox electrolyte on performance. Importantly, the use of additives in the electrolyte allowed the best efficiency ever recorded for an iron-based DSSC to be reached.

Rational Design Combining Morphology and Charge-Dynamic for Hematite/Nickel-Iron Oxide Thin-Layer Photoanodes: Insights into the Role of the Absorber/Catalyst Junction.

Water oxidation represents the anodic reaction in most of the photoelectrosynthetic setups for artificial photosynthesis developed so far. The efficiency of the overall process strongly depends on the joint exploitation of good absorber domains and interfaces with minimized recombination pathways. To this end, we report on the effective coupling of thin-layer hematite with amorphous porous nickel-iron oxide catalysts prepared via pulsed laser deposition.

Copper excess reduces nitrate uptake by Arabidopsis roots with specific effects on gene expression.

Nitrate uptake by plants is mediated by specific transport proteins in roots (NRTs), which are also dependent on the activity of proton pumps that energize the reaction. Nitrogen (N) metabolism in plants is sensitive to copper (Cu) toxicity conditions. To understand how Cu affects the uptake and assimilation processes, this study assesses the inhibitory effects of elevated Cu levels on the expression of genes related to N absorption, transport and assimilation in roots of Arabidopsis.

Photosynthesis is differently regulated during and after copper-induced nutritional stress in citrus trees.

Antioxidant enzymatic responses in Citrus leaves under Cu-induced stress depends on rootstock genotypes. However, there is a lack of information about how woody plants recover growth capacity after exposure to elevated Cu and whether growth is affected by the redistribution of the metal to new vegetative parts and consequently whether photosynthesis is affected. Therefore, the biomass of plants and Cu concentrations in new leaf flushes were determined in young citrus trees grafted onto contrasting rootstocks [Swingle citrumelo (SW) and Rangpur lime (RL)].

Mechanisms of copper stress alleviation in Citrus trees after metal uptake by leaves or roots.

Nutritional disorders caused by copper (Cu) have affected citrus orchards. Since Cu is foliar sprayed as a pesticide to control citrus diseases, this metal accumulates in the soil. Thereby, we evaluated the effects of Cu leaf absorption after spray of different metal sources, as well as roots absorption on growth, nutritional status, and oxidative stress of young sweet orange trees.

Oxidative stress induced by Cu nutritional disorders in Citrus depends on nitrogen and calcium availability.

Nutritional stress caused by copper (Cu) deficiency or toxicity affects fruit production of citrus orchards worldwide, but this could be minimised by fine-tuned fertilisation in the orchards. Two experiments were performed aiming to evaluate the photosynthetic capacity and the antioxidant enzyme activities of Swingle citrumelo seedlings, grown in nutrient solution (NS) with two levels of nitrogen (N) in the first experiment (adequate-N and high-N) and two levels of calcium (Ca) in the second (low-Ca and adequate-Ca). Plants were then exposed to various Cu levels (low, medium and high) for 15 days.

Dye-sensitized solar cells based on a push-pull zinc phthalocyanine bearing diphenylamine donor groups: computational predictions face experimental reality.

Computational studies have suggested that the integration of secondary amine as donor groups in the structure of unsymmetrical zinc phthalocyanine (ZnPc) should have positive effects on photovoltaic performance, once the molecule is integrated as light harvester in dye sensitized solar cells (DSSCs). Aiming at obtaining experimental confirmation, we synthesized a peripherally substituted push-pull ZnPc bearing three electron donating diphenylamine substituents and a carboxylic acid anchoring group and integrated it as sensitizer in TiO-based DSSCs. Detailed functional characterization of solar energy converting devices resulted in ruling out the original hypothesis.

A new ruthenium black dye design with improved optical properties for transparent dye sensitized solar devices.

We report here on the preparation and on the electronic properties of a panchromatic Ru(ii) sensitizer based on a new ligand which allows for higher molar extinction coefficients in the visible and better performances (32% efficiency improvement) over conventional "black dye" in transparent DSSC.

Photoelectrochemical Behavior of Electrophoretically Deposited Hematite Thin Films Modified with Ti(IV).

Doping hematite with different elements is a common strategy to improve the electrocatalytic activity towards the water oxidation reaction, although the exact effect of these external agents is not yet clearly understood. Using a feasible electrophoretic procedure, we prepared modified hematite films by introducing in the deposition solution Ti(IV) butoxide. Photoelectrochemical performances of all the modified electrodes were superior to the unmodified one, with a 4-fold increase in the photocurrent at 0.

Anatomical and Physiological Responses of Citrus Trees to Varying Boron Availability Are Dependent on Rootstock.

In Citrus, water, nutrient transport and thereby fruit production, are influenced among other factors, by the interaction between rootstock and boron (B) nutrition. This study aimed to investigate how B affects the anatomical structure of roots and leaves as well as leaf gas exchange in sweet orange trees grafted on two contrasting rootstocks in response to B supply. Plants grafted on Swingle citrumelo or Sunki mandarin were grown in a nutrient solution of varying B concentration (deficient, adequate, and excessive).

Uptake and distribution of soil applied zinc by citrus trees-addressing fertilizer use efficiency with 68Zn labeling.

The zinc (Zn) supply increases the fruit yield of Citrus trees that are grown, especially in the highly weathered soils of the tropics due to the inherently low nutrient availability in the soil solution. Leaf sprays containing micronutrients are commonly applied to orchards, even though the nutrient supply via soil could be of practical value. This study aimed to evaluate the effect of Zn fertilizers that are applied to the soil surface on absorption and partitioning of the nutrient by citrus trees.