Sample Concentration Research Articles

Human health risk assessment of metal contamination in cereals and pulses in the mica mining areas of Jharkhand, India

This study was carried to investigate the contamination levels of heavy in food crops (rice, wheat, maize, and pulses) grown in the vicinity of the mica mine in Jharkhand, India. Except for Pb and Zn in select places, the metal concentrations in the food crops were below the maximum allowed levels for food in India. The principal component analysis identified three components that accounted for 71.3 % of the variability in the data. The components that were retrieved indicated that soil, irrigation water, and air dust deposition could be the sources of metals in the food crops. The estimated daily intake (EDI) and target hazard quotient (THQ) of food crop consumption were used to highlight the potential health concerns associated with metal exposure. In several samples, local individuals' daily intakes of Pb was greater than the WHO's recommended daily intakes of these heavy metals. Taking into account the geometric mean of metal concentrations in food crops samples from the, the hazard index (HI) for the consumers was 10.28 which is far above unity. Pb, Co, and As were the primary contributors to the potential non-carcinogenic risk. The HI ranged from 7.22 to 18.29 across different locations, indicating a significant health risk to the consumers of locally grown food crops in the vicinity of the mica mining areas.

Proficiency test of SARS-CoV-2 Omicron variant detection in diagnostics samples by veterinary diagnostic laboratories

AbstractVeterinary diagnostic laboratories (VDLs) play a critical role in screening both human and animal samples for SARS-CoV-2. To evaluate the SARS-CoV-2 detection methods used by VDLs, a proficiency test was performed by the US Food and Drug Administration’s Veterinary Laboratory and Investigation and Response Network in collaboration with two other organizations. Thirty-two sets of 12 blind-coded samples were prepared by fortifying Molecular Transport Medium (MTM) or feline feces with SARS-CoV-2 Omicron variant or non-SARS-CoV-2 equine coronavirus RNA at various concentrations and shipped to 32 participants for blinded (unbiased) analysis. Results were analyzed according to the principles of International Organization for Standardization 16140-2:2016 using two approaches such as establishing the rate of detection (ROD) and the success rate by applying the analysis of binary outcome by logit approach. ROD provided the overall assessment of laboratories performance, whereas the novel logit approach provided an insight to more specific analysis based on the complexity of each sample. The ROD was 83% and 98% for MTM samples at 200 and 20000 genome copies per 100 µL, respectively. Fecal samples were classified as challenging exploratory, and results were not included in the assessment of performance but discussion purposes only. Fecal samples exhibited matrix interference impacting the performance. The ROD was 44% and 89% for fecal samples at 2000 and 20000 genome copies per 100 µL, respectively. The non-COVID coronavirus RNA, which was used to address the specificity, did not interfere with methods used. Establishing the success rate by evaluating the qualitative results (detected/not detected) applying a logit approach revealed that, out of thirty-two participants, twenty-eight had satisfactory results, one participant had unsatisfactory results, and three participants had questionable results for MTM samples. For fecal samples, three participants out of thirty-two did not meet the expectations at higher concentrations. Lower concentrations of fecal samples were excluded from this analysis. Again, the fecal samples were considered as challenge samples and the results were provided to assist participants in their continuous efforts to improve their performance and not to evaluate their performance.

Enhancing bricks with titanium dioxide ore waste: Mechanical and environmental assessments

Using residues, generated in various production chains of goods and services through developing new materials for civil construction, has proven to be a promising approach to addressing environmental issues. The residue generated during titanium dioxide (TiO2) production, commonly called Unreacted Ore Waste (UOW), presents potential utilization routes in the ceramic materials production chain, thereby avoiding disposal in industrial landfills. This study aimed to investigate the effects of combining UOW with ceramic blocks for any beneficial results. The properties of ceramic blocks obtained from the mixture of clay and UOW were evaluated after adding 5 %, 10 %, 15 %, and 20 % of UOW relative to the clay’s total mass. The ceramic blocks produced were assessed for their mechanical, photocatalytic, morphological, granulometric, mineralogical, and chemical properties. The results indicated that UOW did not negatively affect the structural properties studied. The addition of UOW led to a significant 9 % increase in the self-cleaning efficacy of the ceramic block produced. The textural parameter values of the ceramic blocks decreased with UOW incorporation due to more efficient particle packing. The surface area reduced from 16.6 to 9.1 m2/g, and the pore volume decreased from 0.045 to 0.025 cm3/g for samples from 0 % to 20 % UOW, respectively. Decreased porosity values contributed to increased compressive strength, resulting in a 6.5 MPa increment. The results suggested that the addition of UOW causes an increase in Al concentrations in leachate samples, from 647.64 to 5128.92 ppb for samples from 0 % to 20 % UOW, respectively. The presence of leachate and solubilized components from UOW impaired the germination of Lactuca sativa seeds. Based on the results, although the addition of UOW resulted in toxicity from the leachate/solubilized components, it did not adversely affect any fundamental properties of the ceramic materials. It can be incorporated up to 20 % into the process, replacing traditional raw materials. This suggests promising future trends in sustainable construction, with broader applications in the development of eco-friendly building materials.

Isolation and Characterization of Exosomes from Ocular Samples.

Exosomes are microsize vesicles secreted by nearly all cells to the extracellular space. The vesicles transport cell signaling and communicate with other cells. Ultracentrifugation is the standard method to isolate exosomes from culture media or body fluid. Without ultracentrifuge, exosomes can be precipitated by polyethylene glycol or separated by size exclusion chromatography. After isolation, nanoparticle tracking analysis can help to estimate the size and concentration of exosome samples. Transmission electron microscopy can directly show the size and morphology of exosomes. Moreover, the sample should be characterized by the expression of several exosome biomarker proteins. Exosomal contents such as proteins and miRNAs could be profiled using appropriate technologies.

Partitioning of Neutral PFAS in Homes and Release to the Outdoor Environment: Results from the IPA Campaign.

The distribution and fate of per- and polyfluoroalkyl substances (PFAS) in homes are not well understood. To address this, we measured nine neutral PFAS in dust, airborne particles, dryer lint, and on heating and air conditioning (HAC) filters in 11 homes in North Carolina as part of the Indoor PFAS Assessment (IPA) Campaign and compared them with concurrently collected gas and cloth measurements. Fluorotelomer alcohols (FTOHs) contributed most (≥75%) to total (∑) measured neutral PFAS concentrations in dust, HAC filter, and dryer lint samples, with mean ∑(FTOH) concentrations of 207 ng/g, 549 ng/g, and 84 ng/g, respectively. In particles, perfluorooctane sulfonamidoethanols (FOSEs) dominated, with a mean ∑(FOSE) concentration of 0.28 ng/m3 or 75,467 ng/g. For FTOHs and FOSEs, resulting mean dust-air, HAC filter-air, dryer lint-air and particle-air partition coefficients in units of log(m3/μg) ranged (across species) from -5.1 to -3.6, -4.9 to -3.5, -5.4 to -4.1, and -3.2 to -0.78, respectively. We estimate that cloth, gas phase, and HAC filters are the largest reservoirs for FTOHs, while cloth, HAC filters, and dust are the largest reservoirs for FOSEs. Release rates of neutral PFAS from homes to the outdoor environment are reported.

Quantifying the sweetness intensity and impact of aroma in honey from four floral sources.

Unlike many commercial sweeteners for which sweetness dose-response curves have been constructed, honey's sweetness has yet to be quantified. Honey differs from most commercial sweeteners in that it has a robust aroma; this aroma may impact its perceived sweetness. This study quantified the sweetness intensity and the impact of aroma on the perceived sweetness of four different honey varieties (clover, wildflower, alfalfa, and orange) compared to sucrose. Each sweetener evaluated was diluted to six concentrations in water ranging from 12.5g/L to 125g/L. Panelists (n=55) rated the sweetness intensities with and without aroma, in replicate, on the Global Sensory Intensity Scale. Additionally, the volatile organic compounds in the honey samples were profiled using gas chromatography-mass spectrometry (GC/MS) analysis. Honey and sugar were equivalently sweet at a given concentration (g/L), with aroma present (p=0.251). Additionally, honey and sugar were not equivalently sweet without aroma; aroma significantly increased sweetness intensities for all sweeteners (p=0.042) and especially honeys. In a 100g/L solution, the aromas in honey increased its sweetness by 23%-43%, depending on the floral source. Compounds with sweet aroma characteristics were identified at high concentrations in all honey samples using GC/MS analysis, including furfural, benzaldehyde, benzene acetaldehyde, and dimethyl sulfide. Additionally, (S)-limonene and toluene were present in high quantities in the orange and alfalfa samples. This study can inform appropriate honey usage levels and identify major volatiles that may enhance sweetness. PRACTICAL APPLICATION: Honey sweetness has not been determined quantitatively, despite the widespread use of honey among consumers and product formulators. Sweetness enhancement by honey aroma volatiles may support a reduction in added sugars while maintaining sweetness intensity.

Improved Standard Addition Method for Measuring Stable Isotopic Compositions and Its Application to Sulfur Isotope Composition.

The standard addition method (SAM) is widely used to measure the isotopic compositions of natural samples, particularly those with a complex matrix. However, traditional SAM has limitations for isotope systems with significant variations in isotope composition due to its reliance on approximation in calculation and the requirement for a priori estimates of analyte isotopic compositions and accurate concentrations. To overcome the issues, our work proposes an improved SAM that explicitly calculates isotope ratio R (i.e., XE/YE, 34S/32S for example) instead of approximating R* (mass number of isotope X divided by total mass number of all isotopes of an element) with R in SAM. Additionally, the sample fraction within standard-sample mixture in improved SAM is determined using the isotope compositions of standards, sample-standard mixtures, and the mixtures of both standards, rather than relying on sample concentrations and volumes. Both improvements not only overcome the shortcomings of traditional SAM but also empowered the approach's ability to accurately determine sample concentrations. To validate its effectiveness, we applied the improved SAM to natural samples with substantial sulfur (S) isotope variation (1.94 to 27.19‰) and low S concentration (0.81 to 3.47 μg g-1). The calculated δ34S values and concentrations of these samples are consistent with direct measurements within the error ranges while reducing sample sizes to 20% of those required for direct measurement. Moreover, our method achieves higher accuracy in δ34S values compared with traditional SAM. Both comparisons affirm the reliability and superiority of improved SAM.

Estimation of the Effective Radiation Dose in Nuclear Medicine Workers from Dhaka by Measuring Radioactivity in Urine Sample Resulting from Internal Exposure

This study estimates the effective doses and activity concentration from 151 urine samples which are collected from 15 (Fifteen) occupational workers at National Institute of Nuclear Medicine and Allied Science (NINMAS) in Dhaka, Bangladesh. The radioactivity concentration in urine sample is due to intake of I-131, Tc-99m and F-18. The samples have been analyzed using High Purity Germanium (HPGe) detector. The radioactivity of I-131 and Tc-99m was found 0.91 ± 0.26 BqL-1 to 504.49 ± 6.03 BqL-1 and 0.15 ± 0.21 BqL-1 to 191.19 ± 6.98 BqL-1 respectively. Radioactivity of F-18 was found from 0.031 ± 0.022 BqL-1 to 0.282 ± 0.065 BqL-1. The effective doses of occupational workers have been also calculated using the radioactivity concentration and the dose coefficient according to ICRP publication 78. Jagannath University Journal of Science, Volume 11, Number 1, June 2024, pp. 64−80

A novel double-door-opening sensor for visual determination of cardiac troponin I based on DNA hydrogel and bimetallic nanozyme

Cardiac troponin I (cTnI), as a cardiac biomarker, holds significant importance in the diagnosis of acute myocardial infarction. However, the current detection methods mostly require specialized personnel and large analytical instruments, making it difficult to achieve convenient and on-site testing. This situation leads to delayed disease diagnosis and treatment, that increases patient suffering, and reduces the cure rate. This strategy presents the development of a portable visual DNA hydrogel colorimetric sensing platform based on a smartphone. Utilizing dual-mode detection with ultraviolet signals and solution colorimetry, the platform achieves ultra-sensitive and real-time detection of cTnI. Furthermore, optimization of detection conditions, such as the amount of polyacrylamide, reaction time, aptamer concentration, encapsulation of the nanozyme, incubation time, and reaction temperature, were performed based on this platform. The proposed ultraviolet and visual detection platforms exhibited good linear relationships with the signal within the ranges of 0.003 ng mL−1 to 10.00 ng mL−1 and 0.01 ng mL−1 to 7.00 ng mL−1, with detection limits of 2.57 pg mL−1 and 0.013 pg mL−1, respectively. Additionally, utilizing 3D printing technology, a portable detection device was designed and employed for the detection of cTnI concentrations in human serum samples. Whatever in the initial and spiked samples, the results showed high sensitivities. The sensitivity and convenience of the sensor in detecting cTnI make it promising for home testing of patients, with broad market prospects.

Venous Excess Ultrasound Score Is Associated with Worsening Renal Function and Reduced Natriuretic Response in Patients with Acute Heart Failure.

Background: The venous excess ultrasound score (VExUS) is used to objectify systemic venous congestion. The aim of the paper was to determine the association between VExUS grades and worsening renal function (WRF), reduced natriuretic response, diuretics resistance, and mortality in patients with acute heart failure (AHF). Methods: One hundred patients were included, and Doppler ultrasound of hepatic, portal, and renal veins was performed. Severity of congestion was graded using the VExUS score (grade 0, 1, 2, or 3). Sodium concentration in a spot urine sample was assessed in 2 h after the first loop diuretic administration and was adjusted for the prescribed dose of furosemide (31 mmol/40 mg). Diuretics resistance was defined as the need to double the starting dose of intravenous furosemide in 6 h. Results: Patients with VExUS grade 3 showed a higher incidence of WRF (OR: 11.17; 95% CI: 3.86-32.29; p < 0.001) and a decreased natriuretic response: a spot urine sodium content of <50 mmol/L (OR: 21.53; 95% CI: 5.32-87.06; p < 0.001) and an adjusted spot urine sodium content of <31 mmol/40 mg (OR: 9.05; 95% CI: 3.15-25.96; p < 0.001). The risk of diuretic resistance (OR: 15.31; 95% CI: 5.05-46.43; p < 0.001), as well as the need for inotropic and/or vasopressor support (OR: 11.82; 95% CI: 3.59-38.92; p < 0.001), was higher in patients with severe congestion. The hospital mortality rate increased in patients with VExUS grade 3 compared to in patients with other grades (OR: 26.4; 95% CI: 5.29-131.55; p < 0.001). Conclusions: Patients with AHF and VExUS grade 3 showed a higher risk of developing WRF, a decreased diuretic and natriuretic response, a need for inotropic and/or vasopressor support, and a poor prognosis during their hospital stay.

Utilization of Hibiscus, Tamarind and Carob in Production of Low Calories Healthy Soft Drinks

The demand for carbonated beverages is increasing, offering opportunities to develop drinks with significant health benefits. Beverages containing carob, tamarind and hibiscus offer multiple nutritional and functional benefits and can serve as healthy alternatives to other soft drinks on the market. This is particularly important given the high sugar and calorie content of traditional soft drinks, which has been linked to increased issues associated with obesity, type 2 diabetes, osteoporosis and cardiovascular disease globally. The focus of the current work is to evaluate low-calorie soft drinks made from hibiscus, tamarind and carob and sweetened with erythritol that cater to diverse consumer segments, including diabetics and health-conscious individuals. Hibiscus, tamarind and carob extracts were sweetened with 0.5, 1 and 1.5 g erythritol sugar/200 ml carbonated beverage. The results showed that the alcoholic extract from hibiscus cups gave the highest content of phenols and flavonoids (70.3 mg gallic/g on DW and 7.8 mg catechin/g on DW), followed by carob pod alcoholic extract (19.3 mg gallic/g on DW) and tamarind alcoholic extract (11.6 mg gallic/g on DW). Tamarind gave a higher content of flavonoids (2.3 mg/g) than carob (1.2 mg/g); however, carob pods had the highest antioxidant activity (91.92%), followed by tamarind pulp (87.66%) and hibiscus cups (79.76%). The soft drinks of hibiscus and tamarind sweetened with erythritol at 1.5 g/200 ml gave the best sensory properties compared with control (adjusted by sucrose at 12% brix) and others concentrations used of erythritol sugar at (0.5 and 1.5 g /200 ml carbonated beverage). Carob pods soft drink sweetened with 0.5 g erythritol /200 ml gave the best sensory characteristics compared to the control sample and others concentrations of erythritol sugar at (1 and 1.5 g /200 ml carbonated beverage), which may be due to the high content of sugars in carob. Hibiscus carbonated beverage outperformed tamarind in terms of overall acceptability and carob carbonated beverage was the least acceptable in terms of sensory properties. Carob carbonated beverage recorded the highest antioxidant activity (90.9%) and phenolic content while representing the second highest in terms of flavonoids. Tamarind carbonated beverage ranked second in terms of antioxidant activity (86.0%) and phenolic content although it ranked first in terms of flavonoids. Hibiscus carbonated beverage recorded the lowest content in terms of antioxidant activity (79.36%), phenolic compounds and flavonoids. Hibiscus, tamarind and carob are a great choice for the production of carbonated beverages because they give the beverage desirable nutritional, cosmetic and medicinal qualities. Moreover, the simplicity of production and availability of raw materials allows for the stimulation of the economy by reducing dependence on multinational companies offering unhealthy or industrialized soft drinks.

Enhancing sensitivity in fluorescence measurements across an ultra-wide concentration range through optimizing combined-segments strategy

Fluorescence measurement technology is crucial in analytical instrumentation. However, when applied in fields such as environmental science and medical research for quantification purposes, it requires prior estimation of sample concentration and sample dilution to ensure measurement precision. This requirement presents challenge for its broader application in online fluorescence sensing. This study addresses the challenge of achieving high-precision measurements across an ultra-wide concentration range, which is critical for applications ranging from environmental monitoring to clinical diagnostics. The binary segmentation method can initially achieve the goal of ultra-wide range fluorescence measurement, but it fails to maintain sensitivity and precision across the entire range, with relative errors exceeding ±15%. Therefore, we propose an optimizing combined-segments strategy, which examines the effects of adjusting the fluorescence reception position, range, and region interval parameters of the fluorescence reception probes on measurement sensitivity limits. This strategy aims to find the optimal measurement sensitivity limit (lmopt) and the best combined-segments configuration based on more than one quantitative relationship curves. Experimental results demonstrate that within a concentration range 20 times broader than the linear range, it can effectively maintain relative errors within ±5%. This enhances the applicability of fluorescence sensing techniques in various practical settings and advances online and direct fluorescence measurement technologies across an ultra-wide concentration range.

Using Femtosecond Laser Light to Investigate the Concentration- and Size-Dependent Nonlinear Optical Properties of Laser-Ablated CuO Quantum Dots.

In this work, the nonlinear optical (NLO) properties of CuO nanoparticles (CuO NPs) were studied experimentally using the pulsed laser ablation (PLA) technique. A nanosecond Nd: YAG laser was employed as the ablation excitation source to create CuO NPs in distilled water. Various CuO NPs samples were prepared at ablation periods of 20, 30, and 40 min. Utilizing HR-TEM, the structure of the synthesized CuO NPs samples was verified. In addition, a UV-VIS spectrophotometer was used to investigate the linear features of the samples. The Z-scan technique was utilized to explore the NLO properties of CuO NPs samples, including the nonlinear absorption coefficient (β) and nonlinear refractive index (n2). An experimental study on the NLO features was conducted at a variety of excitation wavelengths (750-850 nm), average excitation powers (0.8-1.2 W), and CuO NPs sample concentrations and sizes. The reverse saturable absorption (RSA) behavior of all CuO NPs samples differed with the excitation wavelength and average excitation power. In addition, the CuO NPs samples demonstrated excellent optical limiters at various excitation wavelengths, with limitations dependent on the size and concentration of CuO NPs.

Construction of all-solid-state ion-selective sensors using electrolyte-containing polymers.

All-solid-state NO3-, K+, NH4+, Na+, and Ca2+ ion-selective sensors (ISEs) were prepared using polyvinyl butyral (S-LEC®K KX-5). In the present case, polyvinyl butyral was used as a porous material to keep the internal solution of the respective ISE. All sensors exhibited near-Nernst responses in the concentration region between approximately 10-5 and 0.1moldm-3. To avoid the influence of KCl as interfering ions, MgSO4 was used as an electrolyte within the salt bridge. Although the liquid junction potential was generated, the potential difference was stabilized within about few minutes. The NO3--ISE showed high stability with no potential drift during 12h of continuous measurements and maintained high sensitivity even after 3weeks of storage in ultrapure water. Solidification of the internal solution is expected to make the sensor smaller and increase its mechanical strength. As an actual measurement, the sodium concentration in plasma samples using the Na+-ISE was measured to confirm agreement with literature values.

Long-term stability of sufentanil quantified by UPLC-MS-MS in human plasma frozen for 11 years at -20°C.

The long-term stability of drug concentrations in human plasma samples when stored under normal laboratory conditions over several years is important for research purposes and clinical re-evaluation, but also for forensic toxicology. Fifty human plasma samples from a former clinical trial were re-analyzed after storage at -20°C for 11 years. Plasma samples were extracted using solid-phase extraction. Isotope labelled sufentanil-D5 was used as internal standard. Sufentanil plasma concentrations were determined by ultra-performance liquid chromatography (UPLC) with gradient elution, followed by tandem mass spectrometry with electrospray ionization. The linear dynamic range (LDR) was 25 - 2500 pg/mL, the limit of detection was 10 pg/mL, and the lower limit of quantification was 25 pg/mL. Intra- and inter-assay error did not exceed 6%. The deviation of the measured sufentanil plasma concentrations between the reanalysis and the first analysis was -63 ± 14% (mean ± SD). Therefore, sufentanil concentrations in human plasma were not stable in samples frozen at -20°C over 11 years.

Evaluating vitamin D status in Chinese pre-school children using dried blood spots coupled with liquid chromatograph coupled with mass spectrometer.

Vitamin D is an essential micronutrient for multiple physiological processes, and its deficiency remains a world-wide public health problem that cannot be ignored. Dried blood spot (DBS) is a convenient tool in large-scale epidemiological studies, but its application in evaluating vitamin D status in Chinese population is still scarce. Herein, we aimed to determine the vitamin D status in Chinese pre-school children using DBS coupled with LC-MS/MS method. We first developed a sensitive and reliable method for the determination of 25-hydroxyvitamin D (25(OH)D) in DBS samples using an ultra-high-performance liquid chromatograph coupled with triple quadrupole mass spectrometer (UHPLC-QQQ-MS/MS). Next, we conducted a pilot study to compare the 25(OH)D concentration in DBS and serum samples. Finally, the assay method was used to evaluate vitamin D status in Chinese pre-school children. The present method was validated to be reliable and robust for the determination of 25(OH)D in DBS samples. Comparable consistency was observed between the 25(OH)D concentration in DBS and serum samples. A total of 3826 DBS samples collected from children aged 1-7 years were determined. The median concentration of 25(OH)D was 19.57 ng/mL (interquartile range 14.73-24.36 ng/mL), and decreased from 1 to 7 years of age. In addition, 13.51% of male children and 15.12% female children are found to be deficient in 25(OH)D. DBS coupled with LC-MS/MS is a feasible strategy to evaluate vitamin D status in epidemiological studies. And vitamin D deficiency remains a common health problem in Chinese pre-school children.

Accuracy of urinary dipstick for glucose and protein determination in canine cerebrospinal fluid.

To evaluate the precision of urinary dipstick (UD) to assess protein and glucose concentrations in canine CSF samples compared to the standard methods. Cerebrospinal fluid protein and glucose were measured in 22 samples from dogs with neurological diseases affecting the CNS using UD and biochemistry (pyrogallol red and glucose oxidase reaction, respectively). Results were converted into scores to allow comparison between methods. The proportion of divergence between methods and its CI were calculated. The sensitivity (Se), specificity (Sp), positive predictive value (PPV), negative predictive value (NPV), and accuracy (Ac) of UD were determined for 2 cutoff levels of CSF protein (15 and 30 mg/dL) and glucose (40 and 100 mg/dL). The proportion of divergence between methods was 64% (95% CI, 44% to 84%) for CSF protein (representing 14 of 22 erroneous samples), of which 92.9% (13 of 14) had a UD score lower than biochemistry. For CSF glucose, 73% (16 of 22 erroneous samples; 95% CI, 54% to 91%) had divergence between methods, of which 87.5% (14 of 16) had a UD score higher than biochemistry. Urinary dipstick had better results when the cutoff level was 15 mg/dL for protein (Se, 78.9%; Sp, 66.7%; PPV, 93.7%; NPV, 33.3%; Ac, 77.3%) and 40 mg/dL for glucose (Se, 89.5%; Sp, 33.3%; PPV, 89.5%; NPV, 33.3%; Ac, 81.8%) concentrations. Urinary dipstick was unreliable in estimating canine CSF protein and glucose concentrations. The UD underestimated protein and overestimated glucose levels in the canine CSF, which could have a significant diagnostic impact and should discourage its use as a bedside test.

Effect of Pregnancy on Mercury Concentration in the Body of Free-living Small Rodents.

Relatively little information exists on the effects of mercury on terrestrial wildlife populations. We analyzed 38 free-living small rodent females (Myodes glareolus, Microtus agrestris, and Apodemus flavicolis), of which 11 were pregnant, for total mercury concentrations in combined liver and kidney samples. Using a single-purpose atomic absorption spectrometer for mercury determination, the measured mercury values ranged from 0.006 to 0.079 mg/kg. Pregnant females had significantly (P<0.041) higher mercury levels in liver and kidney than did nonpregnant females. Our results suggest that during mercury biomonitoring studies it is necessary to consider the pregnancy of the analyzed animals.

The Effect of Urinary Polycyclic Aromatic Hydrocarbon Metabolites on Lipid Profiles: Does Oxidative Stress Play a Crucial Mediation Role?

Urinary polycyclic aromatic hydrocarbon (PAH) metabolites are associated with oxidative stress; however, epidemiological studies have not reported the impacts of these urinary PAH metabolites on blood lipid levels. This study investigated the relationship between urinary PAH metabolites, urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG), and blood lipid profiles. A total of 109 elderly volunteers were recruited with complete datasets for analysis. Blood and morning urine samples were collected in the winter of 2011. The PAH metabolites, creatinine, and 8-OHdG levels in urine samples were analyzed using Gas Chromatography-Mass Spectrometry, spectrophotometry, and an ELISA kit, respectively. The blood lipid profiles were analyzed using an automatic biochemical analyzer. The relationship between lipid profiles and 8-OHdG was assessed using a two-independent sample nonparametric test, categorized by gender, smoking, and alcohol consumption status. After normalizing the concentration values, a general linear regression model was employed to examine the correlations between PAH metabolites, 8-OHdG, and lipid profiles. A mediation model was developed to investigate the mediating effect of 8-OHdG on the relationship between PAH metabolites and lipid profiles. The median of eight PAH metabolite concentrations in urine samples ranged from 1 to 10 μmol/mol creatinine (Cr). Significant differences in lipid profiles were observed across genders. However, no significant differences were found in smoking or alcohol consumption status for both genders. Linear regression analysis revealed that an increase in the logarithmic concentration of 2-hydroxynaphthalene (2-OHNap), 9-hydroxyfluorene (9-OHFlu), 3-hydroxyfluorene (3-OHFlu), 2-hydroxyfluorene (2-OHFlu), 1-hydroxypyrene (1-OHPyr), and 6-hydroxychrysene (6-OHChr) was associated with an increase in urinary 8-OHdG levels, after adjusting for BMI and age. Specifically, 1-hydroxynaphthalene (1-OHNap) and 1-OHPyr correlated negatively with apolipoprotein A1 (Apo A1). Conversely, 1-OHPyr was positively correlated with low-density lipoprotein cholesterol (LDL-C). In addition, b,c-dihydroxyphenanthrene (2-OHBcPhe) was positively associated with apolipoprotein B (Apo B). Notably, 8-OHdG did not exhibit a significant correlation with lipid profiles. The mediating effect of 8-OHdG on the relationship between hydroxylated PAHs and lipid profiles was not statistically significant. However, the indirect effects of hydroxylated PAHs on blood lipids were statistically substantial, specifically for 1-OHNap to Apo A1 (-0.025, 95% CI: -0.041, -0.009), 1-OHPyr to LDL-C (0.107, 95% CI: 0.011, 0.203), and 2-OHBcPhe to Apo B (0.070, 95% CI: 0.005, 0.135). This study suggests that an increase in urinary PAH metabolites may elevate the levels of urinary 8-OHdG and influence blood lipid profiles. However, no direct relationship was found between 8-OHdG and lipid profiles. The mediation analysis indicated that the effects of PAH metabolites on lipid changes may operate through pathways other than oxidative stress.

Modular Point-of-Need Tropane Alkaloid Detection at Regulatory Levels: Combining Solid-Liquid Extraction from Buckwheat with a Paper-Immobilized Liquid-Phase Microextraction and Immuno-Detection in Interconnectable 3D-Printed Devices.

Contamination with tropane alkaloids in cereals is expected to increase globally. However, current identification tools (e.g., liquid chromatography-mass spectrometry) for tropane alkaloids are time-consuming and expensive. Furthermore, their miniaturized alternatives lack sensitivity and robustness. Therefore, there is a pressing need for inexpensive and effective screening methods. Here, an on-site applicable modular workflow for tropane alkaloid detection in buckwheat is presented. The modular workflow combines paper microfluidics and interconnectable 3D-printed sample preparation tools and was evaluated for different tropane alkaloids, including atropine and scopolamine. Furthermore, integration with an indirect competitive lateral flow immunoassay (icLFIA) for atropine detection at relevant levels was demonstrated. In the modular workflow, to minimize matrix coextraction, tropane alkaloids were extracted from the milled buckwheat cereals by a mixture of alkaline aqueous and immiscible organic solvents (extraction recoveries: 66-79%). The tropane alkaloids were subsequently concentrated with a newly developed paper-immobilized liquid-phase microextraction (PI-LPME, extraction recoveries: 34-60%, concentration factor to immobilized solution in paper: 60-108×). After the PI-LPME, with an integrated 3D-printed setup, the tropane alkaloids were directly eluted (elution recoveries: 83-93%) and detected with the icLFIA. Digital read-out of the icLFIA, by employing a hand-held reader, enabled semiquantification of atropine (IC50 = 0.56 ng mL-1 in standard solutions). The modular workflow was validated by analyzing 24 blank and spiked buckwheat cereal samples with 5 and 10 μg kg-1 atropine. A cutoff value was established with an estimated false negative rate of 1% and estimated false positive rate of 0.68%. Therefore, the modular workflow can aid in fast, inexpensive, and on-site atropine detection by nonexperts, and when integrated with a scopolamine-specific icLFIA expanded toward scopolamine detection. Moreover, the developed sample extraction and concentration method (PI-LPME) is suitable for the analysis of many other compounds with pH-dependent polarity.