Portable Instrument for Hemoglobin Determination Using Room-Temperature Phosphorescent Carbon Dots

A portable reconfigurable platform for hemoglobin determination based on inner filter quenching of room-temperature phosphorescent carbon dots (CDs) in the presence of H2O2 is described. The electronic setup consists of a light-emitting diode (LED) as the carbon dot optical exciter and a photodiode as a light-to-current converter integrated in the same instrument. The reconfigurable feature provides adaptability to use the platform as an analytical probe for CDs coming from different batches with some variations in luminescence characteristics. The variables of the reaction were optimized, such as pH, concentration of reagents, and response time; as well as the variables of the portable device, such as LED voltage, photodiode sensitivity, and adjustment of the measuring range by a reconfigurable electronic system. The portable device allowed the determination of hemoglobin with good sensitivity, with a detection limit of 6.2 nM and range up to 125 nM.MINECO (Spain) CTQ2016-78754-C2-1-REuropean Union (EU

Stereodivergent, Diels-Alder-initiated organocascades employing α,β-unsaturated acylammonium salts: scope, mechanism, and application.

Chiral α,β-unsaturated acylammonium salts are novel dienophiles enabling enantioselective Diels-Alder-lactonization (DAL) organocascades leading to cis- and trans-fused, bicyclic γ- and δ-lactones from readily prepared dienes, commodity acid chlorides, and a chiral isothiourea organocatalyst under mild conditions. We describe extensions of stereodivergent DAL organocascades to other racemic dienes bearing pendant secondary and tertiary alcohols, and application to a formal synthesis of (+)-dihydrocompactin is described. A combined experimental and computational investigation of unsaturated acylammonium salt formation and the entire DAL organocascade pathway provide a rationalization of the effect of Brønsted base additives and enabled a controllable, diastereodivergent DAL process leading to a full complement of possible stereoisomeric products. Evaluation of free energy and enthalpy barriers in conjunction with experimentally observed temperature effects revealed that the DAL is a rare case of an entropy-controlled diastereoselective process. NMR analysis of diene alcohol-Brønsted base interactions and computational studies provide a plausible explanation of observed stabilization of exo transition-state structures through hydrogen-bonding effects

Taking stock of mangrove and seagrass blue carbon ecosystems: A perspective for future carbon trading

Seagrass and mangroves support a number of ecosystem services, such as sustaining marine fisheries, water clarity, and the protection of shoreline from erosion. Producing a national and global consensus of their total worth is a challenge. More often than not the variety and distal evaluation approaches do not fit comfortably within current market-based economic models, which are arguably more capable of swaying government policy in assessing their preservation over economic development. The exception to this rule is the increasing recognition of the importance of these systems as a carbon sink for combating ‘greenhouse’ gas emissions. In response, these sinks have been labelled as ‘Blue Carbon, a rhetorical tool to distinguish them from terrestrial and ocean sinks, and the different approaches they would require for conservation. However, there are a number of knowledge gaps, untested underlying assumptions, and measurement practicalities in assessing an accurate value of carbon sequestration and storage. Unless these are addressed, then the push for seagrass and mangroves to be included within the carbon-financing network may not be successful. This short communication discusses the limitations of the current blue carbon conceptual model, and provides recommendations for a more limited but robust submission of its present and future worth, required for carbon financing

Real-Time Transient Soot and NOx Virtual Sensors for Diesel Engine using Neuro-Fuzzy Model Tree and Orthogonal Least Squares

Diesel engine combustion and emission formation is highly nonlinear and thus creates a challenge related to engine diagnostics and engine control with emission feedback. This paper presents a novel methodology to address the challenge and develop virtual sensing models for engine exhaust emission. These models are capable of predicting transient emissions accurately and are computationally efficient for control and optimization studies. The emission models developed in this paper belong to the family of hierarchical models, namely “neuro-fuzzy model tree”. The approach is based on divide-and-conquer strategy i.e. to divide a complex problem into multiple simpler subproblems, which can then be identified using simpler class of models. Advanced experimental setup incorporating a medium duty diesel engine is used to generate training data. Fast emission analyzers for soot and NOX provide instantaneous engine-out emissions. Finally, the Engine-In-the-Loop is used to validate the models for predicting transient particulate mass and NOX.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/89877/1/draft_01.pd

Environmental contaminants, parasitism, and neoplasia in white perch Morone americana from Chesapeake Bay, USA

White perch are an abundant demersal fish species in freshwater and oligohaline habitats of the Chesapeake Bay. An avoidance of salinity \u3e 12-15 ppt generally restricts the distribution and movements of fish to within tributaries in the mid to lower Bay, which over time has resulted in the formation of at least three separate stocks in Chesapeake Bay. Sub-populations of white perch that are partially isolated may serve as sentinels of the conditions or stressors in the tributaries in which they reside. Fish are exposed to a variety of environmental contaminants and other anthropogenic stressors that can vary in magnitude based on regional differences in land-use patterns. Health studies of white perch conducted in the 1980s and 1990s revealed a variety of hepatic lesions, including two reports of liver neoplasms, which suggested a sensitivity to degraded habitat or pollution. However, surveys to determine prevalences and potential etiologies of tumors were not determined and the health of white perch in Chesapeake Bay was not investigated again until the studies reported herein. Recent health investigations has revealed associations between neoplasms (cholangiocarcinomas) and bile duct parasites (coccidian and myxozoan) that were not previously described from white perch. These findings raised questions concerning the potential roles of contaminants and parasitism in liver tumor induction in this species. To address knowledge gaps associated with the prevalence and etiology of tumors in white perch, an assessment of environmental contaminants, biomarkers of exposure, biliary parasites, and liver histopathology was required. This study was conducted in two tributaries of the Bay: the Choptank River, an eastern shore tributary with extensive watershed agriculture, and the Severn River, a western shore tributary with extensive development. This dissertation addresses: 1) descriptions and taxonomic placement of the coccidian and myxozoan parasites; 2) measurement of waterborne concentrations of polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides, and brominated diphenyl ethers; 3) detection of biliary metabolites as a biomarker of exposures to PAHs; 4) a histopathological description of parasitic infections, neoplasms and other lesions in the liver of fish; 5) an assessment of the biological and anthropogenic risk factors for neoplasia; and 6) an assessment of splenic and hepatic macrophage aggregates as an alternate biomarker of contaminant exposure