Carbon dots from tryptophan doped glucose for peroxynitrite sensing

Tryptophan doped carbon dots (Trp-CD) were microwave synthesized. The optimum conditions of synthesizing of the Trp-CD were established by response surface multivariate optimization methodologies and were the following: 2.5 g of glucose and 300 mg of tryptophan diluted in 15 mL of water exposed for 5 min to a microwave radiation of 700 W. Trp-CD have an average size of 20 nm, were fluorescent with a quantum yield of 12.4% and the presence of peroxynitrite anion (ONOO−) provokes quenching of the fluorescence. The evaluated analytical methodology for ONOO− detection shows a linear response range from 5 to 25 μM with a limit of detection of 1.5 μM and quantification of 4.9 μM. The capability of the ONOO− quantification was evaluated in standard solutions and in fortified serum samples

Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016

Assessing reactive oxygen and nitrogen species in atmospheric and aquatic environments: analytical challenges and opportunities

Reactive oxygen and nitrogen species (ROS and RNS) play a crucial role in biotic and abiotic processes. In the atmosphere, ROS/RNS are usually associated with air pollution. The ability of certain air particulate matter constituents to influence the formation and cycling of ROS/RNS at the atmosphere-biosphere-hydrosphere interfaces is important for the observed linkages between atmospheric aerosols and adverse health and climate effects. Atmosphere-hydrosphere ROS/RNS exchange fluxes affect the chemical composition of the atmosphere and surface waters compartments, acting both as a source and sink for ROS/RNS. Therefore, detecting and measuring ROS/RNS in this interface is of utmost importance. This article presents a critical review on the analytical challenges and limitations of the existing methodologies to measure ROS/RNS in air particles and surface waters. It also addresses the suitability of novel methodologies based on carbon nanoparticles as potential tools for the detection of ROS/RNS in atmospheric aerosols and aquatic compartments.publishe

Deposition of Aerosols onto Upper Ocean and Their Impacts on Marine Biota

Atmospheric aerosol deposition (wet and dry) is an important source of macro and micronutrients (N, P, C, Si, and Fe) to the oceans. Most of the mass flux of air particles is made of fine mineral particles emitted from arid or semi-arid areas (e.g., deserts) and transported over long distances until deposition to the oceans. However, this atmospheric deposition is affected by anthropogenic activities, which heavily impacts the content and composition of aerosol constituents, contributing to the presence of potentially toxic elements (e.g., Cu). Under this scenario, the deposition of natural and anthropogenic aerosols will impact the biogeochemical cycles of nutrients and toxic elements in the ocean, also affecting (positively or negatively) primary productivity and, ultimately, the marine biota. Given the importance of atmospheric aerosol deposition to the oceans, this paper reviews the existing knowledge on the impacts of aerosol deposition on the biogeochemistry of the upper ocean, and the different responses of marine biota to natural and anthropogenic aerosol input

Enhanced Peripheral Nerve Regeneration By The Combination Of A Polycaprolactone Tubular Prosthesis And A Scaffold Of Collagen With Supramolecular Organization.

The purpose of this study was to investigate the influence of implanting collagen with a supramolecular organization on peripheral nerve regeneration, using the sciatic nerve tubulization technique. For this purpose, adult female Sprague Dawley rats were divided into five groups: (1) TP - sciatic nerve repaired with empty polyethylene tubular prothesis (n = 10), (2) TPCL - nerve repair with empty polycaprolactone (PCL) tubing (n = 8), (3) TPCLF - repair with PCL tubing filled with an implant of collagen with a supramolecular organization (n = 10), (4) AG - animals that received a peripheral nerve autograft (n = 8), and (5) Normal nerves (n = 8). The results were assessed by quantification of the regenerated fibers, nerve morphometry, and transmission electron microscopy, 60 days after surgery. Immunohistochemistry and polarization microscopy were also used to analyze the regenerated nerve structure and cellular elements. The results showed that the AG group presented a larger number of regenerated axons. However, the TPCL and TPCLF groups presented more compact regenerated fibers with a morphometric profile closer to normal, both at the tube midpoint and 2 mm distal to the prosthesis. These findings were reinforced by polarization microscopy, which indicated a better collagen/axons suprastructural organization in the TPCLF derived samples. In addition, the immunohistochemical results obtained using the antibody anti-p75NTR as a Schwann cell reactivity marker demonstrated that the Schwann cells were more reactive during the regenerative process in the TPCLF group as compared to the TPCL group and the normal sciatic nerve. Altogether, the results of this study indicated that the implant of collagen with a supramolecular organization positively influenced and stimulated the regeneration process through the nerve gap, resulting in the formation of a better morphologically arranged tissue.3417-3

Photodynamic oxidation of Staphylococcus warneri membrane phospholipids: new insights based on lipidomics

RATIONALE The photodynamic process involves the combined use of light and a photosensitizer, which, in the presence of oxygen, originates cytotoxic species capable of oxidizing biological molecules, such as lipids. However, the effect of the photodynamic process in the bacterial phospholipid profile by a photosensitizer has never been reported. A lipidomic approach was used to study the photodynamic oxidation of membrane phospholipids of Staphylococcus warneri by a tricationic porphyrin [5,10,15‐tris(1‐methylpyridinium‐4‐yl)‐20‐(pentafluorophenyl)porphyrin triiodide, Tri‐Py+‐Me‐PF]. METHODS S. warneri (108 colony forming units mL–1) was irradiated with white light (4 mW cm–2, 21.6 J cm–2) in the presence of Tri‐Py+‐Me‐PF (5.0 μM). Non‐photosensitized bacteria were used as control (irradiated without porphyrin). After irradiation, total lipids were extracted and separated by thin‐layer chromatography (TLC). Isolated fractions of lipid classes were quantified by phosphorus assay and analyzed by mass spectrometry (MS): off‐line TLC/ESI‐MS, hydrophilic interaction (HILIC)‐LC/MS and MS/MS. RESULTS The most representative classes of S. warneri phospholipids were identified as phosphatidylglycerols (PGs) and cardiolipins (CLs). Lysyl‐phosphatidylglycerols (LPGs), phosphatidylethanolamines (PEs), phosphatidylcholines (PCs) and phosphatidic acids (PAs) were also identified. After photodynamic treatment, an overall increase in the relative abundance of PGs was observed as well as the appearance of new oxidized species from CLs, including hydroxy and hydroperoxy derivatives. Formation of high amounts of lipid hydroperoxides was confirmed by FOX2 assay. Photodynamic oxidation of phospholipid standards revealed the formation of hydroperoxy and dihydroperoxy derivatives, confirming the observed CL oxidized species in S. warneri. CONCLUSIONS Membrane phospholipids of S. warneri are molecular targets of the photoinactivation process induced by Tri‐Py+‐Me‐PF. The overall modification in the relative amount of phospholipids and the formation of lipid hydroxides and hydroperoxides indicate the lethal damage caused to photosensitized bacterial cells.The authors thank Vanessa Oliveira MSc. for her help in bacteria identification by PCR testing. Thanks are due to Fundação para a Ciência e a Tecnologia (FCT, Portugal), European Union, QREN, FEDER and COMPETE for funding the QOPNA research unit (project PEst‐C/QUI/UI0062/2011 and the project PTDC/QUI‐BIQ/104968/2008), to the Portuguese National NMR Network that was also supported by funds from FCT, and to the RNEM (REDE/1504/REM/2005) for the Portuguese Mass Spectrometry Network. Thanks are also due to the Centre for Environmental and Marine Studies for funding the Microbiology Research Group (project Pest‐C/MAR/LA0017/2011). Eliana Alves (SFRH/BD/41806/2007), Tânia Melo (SFRH/BD/84691/2012) and Cláudia Simões (SFRH/BD/46293/2008) are grateful to FCT for their PhD grants.publishe