Behavior of KCl sorbent traps and KCl trapping solutions used for atmospheric mercury speciation: stability and specificity

Atmospheric mercury speciation is of paramount importance for understanding the behavior of mercury once it is emitted into the atmosphere as gaseous elemental mercury (GEM), gaseous oxidized mercury (GOM) and particulate-bound mercury (PBM). GOM and PBM can also be formed in the atmosphere; their sampling is the most problematic step in the atmospheric mercury speciation. GOM sampling with speciation traps composed of KCl sorbent materials and KCl trapping solutions are commonly used sampling methods, although the research conducted with them at ambient air concentrations is limited. The results of the specificity test demonstrated that the KCl sorbent traps are highly specific when using new traps, while their specificity drops dramatically when they are reused. The results of the stability test indicated that the highest Hg2+ losses (up to 5.5 % of Hg2+ loss) occur when low amounts of Hg2+ (< 1 ng) are loaded, due to a reduction of Hg2+ to Hg0. KCl trapping solutions have also been considered as a selective trapping media for GOM in atmospheric samples. A dimensionless Henry law constant was experimentally derived and was used to calculate the solubility of elemental Hg in KCl solution. The degree of GEM oxidation was established by purging elemental Hg calibration gas into a KCl solution and determining the GOM trapped using aqueous-phase propylation liquid–liquid extraction and gas chromatography–atomic fluorescence spectrometry (GC-AFS) measurement. A positive GOM bias was observed due to the solubility and oxidation of GEM in KCl trapping solutions, strongly suggesting that this approach is unsuitable for atmospheric mercury speciation measurements.

Rapid detection of mcyG gene of microcystins producing cyanobacteria in water samples by recombinase polymerase amplification combined with lateral flow strips

Nowadays, cyanobacteria blooms and microcystins (MCs) pollution are threatening water safety and public health. In this study, a rapid detection method was established for detecting MCs producing cyanobacteria. The MC synthesis gene mcyG was measured through recombinase polymerase amplification combined with lateral flow strips (LF-RPA) technology. The target gene mcyG was amplified at a temperature range of 37–45 °C, and the amplification time to detect mcyG was only 15 min at 37 °C. The optimal reaction conditions were confirmed using single dependent variable experiments, suggesting that the best probe dosage for 50 μL of the reaction mixture was 0.2 μL, the best dilution ratio of products was 1/100, and the best loading volume was 10 μL. The specificity test proved that the LF-RPA assay could distinguish MCs producing cyanobacteria from nontoxic algae well. Within 35 min of amplification time, the detection limit of the LF-RPA assay was 103 copies/mL mcyG and 104 cells/mL Microcystis aeruginosa FACHB-905. Overall, the LF-RPA assay could detect MCs producing cyanobacteria in water samples quickly and accurately, and it has a great promise to be applied for monitoring the MCs producing cyanobacteria blooms in natural waters.

Development and validation of a gas chromatography method for the determination of β-caryophyllene in clove extract and its application

The purpose of this study is to check the effectiveness of the analysis method that separates and quantifies β-caryophyllene among clove extracts and validate according to current ICH guidelines. The β-caryophyllene was active constituent of clove buds. The developed method gave a good detection response. In the specificity test, the standard solution was detected at about 17.32 min, and the test solution was detected at 17.32 min. The linearity of β-caryophyllen was confirmed, and at this time, the correlation coefficient (R2) of the calibration curve showed a high linearity of 0.999 or more in the concentration range. The levels of LOD and LOQ were 1.28 ug/mL and 3.89 ug/mL, respectively. The accuracy was confirmed to be 101.6–102.2% and RSD 0.95 ~ 1.31%. As a result of checking the repeatability and inter-tester reproducibility to confirm the precision, the RSD was found to be 1.34 ~ 2.69%. This validated GC method was successfully applied to a soft capsule containing clove extract and other materials for clinical trials. Therefore, this method can be used as an analytical tool for quality control of various samples, including clove extracts and their products of food and pharmaceutical uses.

Behaviour of KCl sorbent traps and KCl trapping solutions used for atmospheric mercury speciation: stability and specificity

Atmospheric mercury speciation is of paramount importance for understanding the behavior of mercury once it is emitted into the atmosphere as gaseous elemental (GEM), gaseous oxidized (GOM) and particulate-bound (PBM) mercury. GOM and PBM sampling are the most problematic steps in the analytical procedure. GOM sampling with speciation traps composed of KCl sorbent materials and KCl trapping solutions are commonly used sampling methods, although the work done at ambient air concentrations is limited. The results of the specificity test showed that the KCl sorbent traps are very specific when using new traps, while their specificity drops dramatically when they are reused. The results of the stability test showed that the highest Hg2+ losses (up to 5.5 % of Hg2+ loss) occur when low amounts of Hg2+ (< 1 ng) are loaded, due to a reduction of Hg2+ to Hg0. GOM losses should be taken into account when using KCl sorbent traps for atmospheric Hg speciation, especially at low ambient GOM concentrations. KCl trapping solutions have also been considered as a selective trapping media for GOM in atmospheric samples. A dimensionless Henry’s law constant was experimentally derived and was used to calculate the solubility of elemental Hg in KCl solution. The degree of GEM oxidation was established by purging elemental Hg calibration gas into a KCl solution and determining the GOM trapped using aqueous phase propylation liquid-liquid extraction GC-AFS. A positive GOM bias was observed due to the solubility and oxidation of GEM in KCl trapping solutions strongly suggesting that this approach is unsuitable for atmospheric mercury speciation measurements.

Evaluation of an Automatic Insulated Isothermal PCR System for Rapid and Reliable Field-Deployable Detection of African Swine Fever Virus

In the present study, we evaluate an automatic sample-to-answer insulated isothermal PCR system for rapid and reliable field-deployable detection of African swine fever virus in comparison to that of OIE recommended real-time PCR counterparts with samples collected in Vietnam. For analytical sensitivity, the system could detect ASFV up to a dilution of 106 whereas the real time PCR systems could detect up to a dilution of 105 to 106. For specificity test, the system showed high specificity to ASFV in compare to different other types of swine pathogens: PRRSV, FMDV, PCV2, CSFV. The diagnostic performance comparison on 6 different types of samples showed 97.3% to 100% agreement with reference real-time PCR. The results of this study indicated that POCKIT Central-based insulated isothermal PCR system is a rapid, reliable and sample-flexible method for effective detection of ASFV.

Sensitivity and specificity test of alarm malnutrition for hospital-acquired malnutrition among pediatric patients

Detecting the risks for hospital-acquired malnutrition in children can be performed by using nutritional screening tools. One of the screening tools that has been created is Alarm Malnutrition. This study aimed to test the sensitivity and specificity of Alarm Malnutrition in detecting the risks for hospitalacquired malnutrition in comparison to Screening Tool for the Risk on Nutritional status and Growth (STRONGkids). This study employed cross sectional design and involved 168 hospitalized children (1 month to 18 years) at pediatric ward. The data were analyzed using diagnostic approach which resulted in sensitivity and specificity values. The statistical tests showed that the sensitivity and specificity values of Alarm Malnutrition and STRONGKids were 32,2% and 81,6% respectively. These results indicated that this screening tool was not better than STRONGkids which has been previously used in Indonesia. Alarm Malnutrition needs to be developed and improved in order to achieve better performance in detecting the risks for hospital-acquired malnutrition.

Development and validation of a gas chromatography method for the determination of β -caryophyllene in clove extract and its application

The purpose of this study is to check the effectiveness of the analysis method that separates and quantifies β-caryophyllene among clove extracts and validate according to current ICH guidelines. The beta caryophyllene was active constituent of clove buds. The developed method gave a good detection response. In the specificity test, the standard solution was detected at about 17.316 minutes, and the test solution was detected at 17.317 minutes. The linearity of β-caryophyllen was confirmed, and at this time, the correlation coefficient (R 2 ) of the calibration curve showed a high linearity of 0.999 or more in the concentration range. The levels of LOD and LOQ were 1.28 ug/mL and 3.89 ug/mL, respectively. The accuracy was confirmed to be 101.6 ~ 102.2% and RSD 0.95 ~ 1.31%. As a result of checking the repeatability and inter-tester reproducibility to confirm the precision, the RSD was found to be 1.34 ~ 2.69%. This validated GC method was successfully applied to a soft capsule containing clove extract and other materials for clinical trials. Therefore, this method can be used as an analytical tool for quality control of various samples including clove extracts and their products for food and pharmaceutical uses.

66Ga-PET-imaging of GRPR-expression in prostate cancer: production and characterization of [66Ga]Ga-NOTA-PEG2-RM26

Molecular imaging of the gastrin-releasing peptide receptor (GRPR) could improve patient management in prostate cancer. This study aimed to produce gallium-66 (T½ = 9.5 h) suitable for radiolabeling, and investigate the imaging properties of gallium-66 labeled GRPR-antagonist NOTA-PEG2-RM26 for later-time point PET-imaging of GRPR expression. Gallium-66 was cyclotron-produced using a liquid target, and enriched [66Zn]Zn(NO3)2. In vitro, [66Ga]Ga-NOTA-PEG2-RM26 was characterized in GRPR-expressing PC-3 prostate cancer cells. In vivo, specificity test and biodistribution studies were performed 3 h and 22 h pi in PC-3 xenografted mice. microPET/MR was performed 3 h and 22 h pi. Biodistribution of [66Ga]Ga-NOTA-PEG2-RM26 was compared with [68Ga]Ga-NOTA-PEG2-RM26 3 h pi. [66Ga]Ga-NOTA-PEG2-RM26 was successfully prepared with preserved binding specificity and high affinity towards GRPR. [66Ga]Ga-NOTA-PEG2-RM26 cleared rapidly from blood via kidneys. Tumor uptake was GRPR-specific and exceeded normal organ uptake. Normal tissue clearance was limited, resulting in no improvement of tumor-to-organ ratios with time. Tumors could be clearly visualized using microPET/MR. Gallium-66 was successfully produced and [66Ga]Ga-NOTA-PEG2-RM26 was able to clearly visualize GRPR-expression both shortly after injection and on the next day using PET. However, delayed imaging did not improve contrast for Ga-labeled NOTA-PEG2-RM26.

Introduction to diagnostic test accuracy studies

Diagnostic accuracy studies are fundamental for the assessment of diagnostic tests. Researchers need to understand the implications of their chosen design, opting for comparative designs where possible. Researchers should analyse test accuracy studies using the appropriate methods, acknowledging the uncertainty of results and avoiding overstating conclusions and ignoring the clinical situation which should inform the trade-off between sensitivity and specificity. Test accuracy studies should be reported with transparency using the STAndards for the Reporting of Diagnostic accuracy studies (STARD) checklist.

Literatur Review : Rapid Immunochromatography Sebagai Metode Skrining Kanker Serviks Berbasis Deteksi Onkoprotein HPV pada Urin

Cervical cancer is still become main health problem especially in development country. This cancer is the second most common cancer in Indonesian women. It commonly caused by infection of Human Papillomavirus (HPV) type 16 and 18. Actually if cervical cancer was detected earlier, it shows better respond therapy than other cancers, but this opportunity is not supported by appropiate screening methods. Nowadays, pap smear and IVA are commonly used for detect cervical cancer but they only recommend for women who have had sexual intercourse. Both of them also require medical expertise and pap smear is highly cost. Based on these problem, this paper describes novel method for cervical cancer screening by using rapid immunochromatography kit which is more applicative, noninvasive, and affordable. This paper was a literature review (library research). Data obtained through the search engine using keywords: "Cervical Cancer", "HPV", "Urine", "Screening", “Lateral flow test”, and "Rapid immunochromatography". The references were taken from reliable journal in the range of 2009 to 2019. Data was also taken from textbooks and the health institution official sites which support the analysis. This method detect the presence of oncoprotein E6 & E7 of HPV-16 and HPV-18 in urinusing antigen-antibody binding principle. Sensitivity and specificity test done by comparing the results of the kit with the results of pap smear tests as a standard screening method and PCR HPV test on urinsamples. We conclude that with further protocol development and standardization to achieve clinical sensitivity, this kit is a solution for noninvasive detection of high risk cervical cancer so that treatment can be do immediately and the mortality rate due to cervical cancer can be reduced as much as possible.