In the past few decades, the development of chemosensors for neurotransmitters has emerged as a research area of significant importance, which attracted a tremendous amount of attention due to its high sensitivity and rapid response. This current review focuses on various neurotransmitter detection based on fluorescent or colorimetric spectrophotometry published for the last 12 years, covering biogenic amines (dopamine, epinephrine, norepinephrine, serotonin, histamine and acetylcholine), amino acids (glutamate, aspartate, GABA, glycine and tyrosine), and adenosine.

c Four different rapid diagnostic tests (RDTs) for malaria were evaluated by testing 82 healthy control patients, 89 Plasmodium vivax-infected patients, and 92 rheumatoid factor (RF)-positive nonmalaria patients. The false-positive rate ranged from 2.2% to 13% in RF-positive patients. High RF levels are associated with malaria RDT false positivity. M alaria remains a major global health problem in tropical and subtropical countries, with high morbidity and mortality and extensive economic loss (1). Malaria rapid diagnostic tests (RDTs) are becoming the clinical diagnostic method of choice due to their quick results and ease of use, even by inexperienced personnel (2). However, false-positive results may be observed in patients with rheumatoid factor (RF), hepatitis C, toxoplasmosis, human African trypanosomiasis, dengue, leishmaniasis, Chagas disease, and schistosomiasis (2). Iqbal et al. (3) reported that 33 of the 35 false-positive specimens were negative when the RF was absorbed in the immunochromatographic test (ICT). The goal of this study was to use four different malaria RDTs to explore the relationship between false-positive malaria RDT results and RF.Between April 2010 and August 2013, a total of 263 wholeblood samples with EDTA were collected from South Korean patients at the Korea University Guro Hospital, Republic of Korea. Of these 263 samples, 89 were infected with malaria, as confirmed by Giemsa-stained microscopic examination, 92 did not have malaria but did have RF, and 82 had neither malaria nor RF. Both microscopy and PCR were used to rule out malaria. Each patient provided informed consent under the protocol for human use, which was approved by the Human Use Ethical Committee, Korea University Guro Hospital.Thick and thin blood films were prepared when blood was drawn in accordance with standard procedures. These films were stained with Giemsa and examined by trained microscopists who did not have prior knowledge of the patients' clinical history. Plasmodium species and the parasite density were determined. The circumsporozoite protein (CSP) gene of Plasmodium vivax was amplified by PCR using previously established methods (4). Four commercial malaria RDT kits were selected based on the multiple target antigens (Ags) detected, the BinaxNOW malaria kit (Binax Inc., Scarborough, ME, USA), the OptiMAL-IT malaria kit (BioRad, Marnes la Coquette, France), the SD Bioline malaria Ag Pf/ Pan rapid test (Standard Diagnostics, Inc., Yongin, South Korea), and the Humasis malaria P.f/Pan antigen test (Humasis, Anyang, South Korea). BinaxNOW detects both histidine-rich protein 2 (HRP-2), which is specific to Plasmodium falciparum, and aldolase, which is a pan-malarial enzyme found in the five human pathogenic Plasmodium species (5). OptiMAL-IT differentiates P. falciparum-specific lactate dehydrogenase (PfLDH) and pan-Plasmodium lactate dehydrogenase (pLDH) by immunological detection (6). The SD Bioline and Humasis tests target HRP-2 for P. falciparum and pLDH for other human malaria species (7,8). All te...

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody assays have high clinical utility in managing the pandemic. We compared antibody responses and seroconversion of coronavirus disease 2019 (COVID-19) patients using different immunoassays.Methods: We evaluated 12 commercial immunoassays, including three automated chemiluminescent immunoassays (Abbott, Roche, and Siemens), three enzyme immunoassays (Bio-Rad, Euroimmun, and Vircell), five lateral flow immunoassays (Boditech Med, SD biosensor, PCL, Sugentech, and Rapigen), and one surrogate neutralizing antibody assay (GenScript) in sequential samples from 49 COVID-19 patients and 10 seroconversion panels.Results: The positive percent agreement (PPA) of assays for a COVID-19 diagnosis ranged from 84.0% to 98.5% for all samples ( > 14 days after symptom onset), with IgM or IgA assays showing higher PPAs. Seroconversion responses varied across the assay type and disease severity. Assays targeting the spike or receptor-binding domain protein showed a tendency for early seroconversion detection and higher index values in patients with severe disease. Index values from SARS-CoV-2 binding antibody assays (three automated assays, one LFIA, and three EIAs) showed moderate to strong correlations with the neutralizing antibody percentage (r = 0.517-0.874), and stronger correlations in patients with severe disease and in assays targeting spike protein. Agreement among the 12 assays was good (74.3%-96.4%) for detecting IgG or total antibodies. Conclusions: Positivity rates and seroconversion of SARS-CoV-2 antibodies vary depending on the assay kits, disease severity, and antigen target. This study contributes to a better understanding of antibody response in symptomatic COVID-19 patients using currently available assays.

BackgroundThe malaria rapid diagnostic tests (RDTs) are now widely used in the world. Compared to Plasmodium falciparum, a poor sensitivity of RDTs was reported against Plasmodium vivax based on the adopted antibody against pan-Plasmodium antigen lactate dehydrogenase (pLDH) or aldolase. Levels of pLDH were measured from patient with P. vivax, and the correlations between the levels of pLDH and the sensitivities of RDTs were analysed among Republic of Korea (ROK) isolates.MethodsThree RDTs, OptiMAL test, SD BIOLINE Malaria Ag P.f/Pan test, Humasis Malaria Pf/Pan antigen test, and the Genedia pLDH antigen ELISA were performed with blood samples from 152 febrile patients and 100 healthy controls.ResultsThree malaria RDTs revealed sensitivities between 85.5 (131/152) and 86.8% (132/152) with highest sensitivity for the detection of P.vivax by pLDH antigen ELISA test (145/152, 95.4%) in comparison to traditional microscopy using Giemsa–stained slides. None of the healthy control tested positive by three RDTs or ELISA, indicating 100% specificity in their respective test. Levels of pLDH among Korean P. vivax isolates ranged between 0 ng/mL and 22,387.2 ng/mL (mean ± standard deviation 3,917.5 ± 6,120.9 ng/mL). The lower detection limits of three RDTs were between 25 and 50 ng/mL with artificially diluted samples. The moderate degree of correlation was observed between parasitaemia and concentrations of pLDH (r = 0.4, p < 0.05).ConclusionThe pLDH levels of P. vivax are the main explanation for the variations in the performance of pLDH-based RDTs. Therefore, comparing sensitivities of RDT may need to include targeted biomarker value of patients.

The existence and stability of the Landau equation (1936) in a general bounded domain with a physical boundary condition is a long-outstanding open problem. This work proves the global stability of the Landau equation with the Coulombic potential in a general smooth bounded domain with the specular reflection boundary condition for initial perturbations of the Maxwellian equilibrium states. The highlight of this work also comes from the low-regularity assumptions made for the initial distribution. This work generalizes the recent global stability result for the Landau equation in a periodic box [42]. Our methods consist of the generalization of the wellposedness theory for the Fokker-Planck equation [37, 38] and the extension of the boundary value problem to a whole space problem, as well as the use of a recent extension of De Giorgi-Nash-Moser theory for the kinetic Fokker-Planck equations [27] and the Morrey estimates [56] to further control the velocity derivatives, which ensures the uniqueness. Our methods provide a new understanding of the grazing collisions in the Landau theory for an initial-boundary value problem. 2010 Mathematics Subject Classification. Primary: 35Q84, 35Q20, 82C40, 35B45, 34C29, 35B65.