Interference of High Degrees Salt on Spectrophotometric Flow Injection Analysis : Quantitative Error of Nitrite from Schlieren Effect and Salt Effect

Interference of high salt concentrations in spectrophotometric flow injection analysis is described. The spectrophotometric determination of nitrite with Griess reagent was used as a test model. Several percentage concentrations of sodium chloride, magnesium chloride, or magnesium sulfate solutions caused more than 10% positive interference in determining 0.040 mg L-1 nitrite. This interference was attributed not only to the schlieren effect but to the salt effect, i.e., the accelerated reaction of nitrite with the Griess reagent

Fetal Goitrous Hypothyroidism due to Maternal Thyroid Stimulation-Blocking Antibody: A Case Report

Most fetal goitrous hypothyroidisms are reportedly caused by the maternal use of an antithyroid drug or fetal dyshormonogenesis. However, fetal goitrous hypothyroidism due to the transplacental passage of maternal thyroid stimulation-blocking antibody (TSBAb) is extremely rare. A woman at 28 weeks of gestation was found to have a fetal goiter by ultrasonography. Because the maternal serum showed hypothyroidism with an elevated titer of TSBAb, levothyroxine sodium was administered. The patient delivered a male infant, 3,412 g, with a goiter at term. Umbilical blood revealed primary hypothyroidism with increased TSBAb, and the infant was given levothyroxine sodium. After a month, neonatal thyroid function and TSBAb levels became normal. Attention should be paid to possible fetal hypothyroidism when a fetal goiter is observed to avoid impaired mental development of the neonate.ArticleFETAL DIAGNOSIS AND THERAPY. 28(4):220-224 (2010)journal articl

Natural dimethyl sulfide gradients would lead marine predators to higher prey biomass

© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Owen, K., Saeki, K., Warren, J. D., Bocconcelli, A., Wiley, D. N., Ohira, S., Bombosch, A., Toda, K., & Zitterbart, D. P. Natural dimethyl sulfide gradients would lead marine predators to higher prey biomass. Communications Biology, 4(1), (2021): 149, https://doi.org/10.1038/s42003-021-01668-3.Finding prey is essential to survival, with marine predators hypothesised to track chemicals such as dimethyl sulfide (DMS) while foraging. Many predators are attracted to artificially released DMS, and laboratory experiments have shown that zooplankton grazing on phytoplankton accelerates DMS release. However, whether natural DMS concentrations are useful for predators and correlated to areas of high prey biomass remains a fundamental knowledge gap. Here, we used concurrent hydroacoustic surveys and in situ DMS measurements to present evidence that zooplankton biomass is spatially correlated to natural DMS concentration in air and seawater. Using agent simulations, we also show that following gradients of DMS would lead zooplankton predators to areas of higher prey biomass than swimming randomly. Further understanding of the conditions and scales over which these gradients occur, and how they are used by predators, is essential to predicting the impact of future changes in the ocean on predator foraging success.Open Access funding enabled and organized by Projekt DEAL. This study was funded by the Herrington Fitch Family Foundation, by the Woods Hole Oceanographic Institution Joint Initiative Awards Fund from the Andrew W. Mellon Foundation and The President’s Investment Fund, and by KAKENHI, Grants-in-Aid for Basic Research (B) (Grant no. 16H04168) and Bilateral Programs Joint Research Projects (open partnership), both from the Japan Society for the Promotion of Science. The authors thank Mrs. Norio Hayashi, Takanori Nagahata, and Ms. Mihoko Asano (Mitsubishi Chemical Analytech Co.) for their support with the SGV-CL device. The research was conducted under Scientific Research Permit number 18059, issued by the National Oceanic and Atmospheric Administration under the Marine Mammal Protection Act

Mobile monitoring along a street canyon and stationary forest air monitoring of formaldehyde by means of a micro gas analysis system

A micro-gas analysis system (μGAS) was developed for mobile monitoring and continuous measurements of atmospheric HCHO. HCHO gas was trapped into an absorbing/reaction solution continuously using a microchannel scrubber in which the microchannels were patterned in a honeycomb structure to form a wide absorbing area with a thin absorbing solution layer. Fluorescence was monitored after reaction of the collected HCHO with 2,4-pentanedione (PD) in the presence of acetic acid/ammonium acetate. The system was portable, battery-driven, highly sensitive (limit of detection = 0.01 ppbv) and had good time resolution (response time 50 s). The results revealed that the PD chemistry was subject to interference from O3. The mechanism of this interference was investigated and the problem was addressed by incorporating a wet denuder. Mobile monitoring was performed along traffic roads, and elevated HCHO levels in a street canyon were evident upon mapping of the obtained data. The system was also applied to stationary monitoring in a forest in which HCHO formed naturally via reaction of biogenic compounds with oxidants. Concentrations of a few ppbv-HCHO and several-tens of ppbv of O3 were then simultaneously monitored with the μGAS in forest air monitoring campaigns. The obtained 1 h average data were compared with those obtained by 1 h impinger collection and offsite GC-MS analysis after derivatization with o-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine (PFBOA). From the obtained data in the forest, daily variations of chemical HCHO production and loss are discussed

Fetal Goitrous Hypothyroidism due to Maternal Thyroid Stimulation-Blocking Antibody: A Case Report

Most fetal goitrous hypothyroidisms are reportedly caused by the maternal use of an antithyroid drug or fetal dyshormonogenesis. However, fetal goitrous hypothyroidism due to the transplacental passage of maternal thyroid stimulation-blocking antibody (TSBAb) is extremely rare. A woman at 28 weeks of gestation was found to have a fetal goiter by ultrasonography. Because the maternal serum showed hypothyroidism with an elevated titer of TSBAb, levothyroxine sodium was administered. The patient delivered a male infant, 3,412 g, with a goiter at term. Umbilical blood revealed primary hypothyroidism with increased TSBAb, and the infant was given levothyroxine sodium. After a month, neonatal thyroid function and TSBAb levels became normal. Attention should be paid to possible fetal hypothyroidism when a fetal goiter is observed to avoid impaired mental development of the neonate.ArticleFETAL DIAGNOSIS AND THERAPY. 28(4):220-224 (2010)journal articl

Abundant production of dimethylsulfoniopropionate as a cryoprotectant by freshwater phytoplanktonic dinoflagellates in ice-covered Lake Baikal

Phytoplanktonic dinoflagellates form colonies between vertical ice crystals during the icemelting season in Lake Baikal, but how the plankton survive the freezing conditions is not known. Here we show that the phytoplankton produces large amounts of dimethylsulfoniopropionate (DMSP), which is best-known as a marine compound. Lake-water DMSP concentrations in the spring season are comparable with those in the oceans, and colony water in ice exhibits extremely high concentrations. DMSP concentration of surface water correlates with plankton density and reaches a maximum in mid-April, with temperature-dependent fluctuations. DMSP is released from plankton cells into water in warm days. DMSP is a characteristic osmolyte of marine algae; our results demonstrate that freshwater plankton, Gymnodinium baicalense, has DMSP-producing ability, and efficiently uses the limited sulfur resource (only 1/500 of sea sulfate) to survive in freshwater ice. Plankton in Lake Baikal do not need an osmolyte, and our results clearly indicate that DMSP plays a cryoprotective role. DMSP, although a characteristic marine compound, could also be an important zwitterion for algae of other boreal lakes, alpine snow, and glaciers