Counts In Samples Research Articles

Promising Markers of Inflammatory and Gut Dysbiosis in Patients with Post-COVID-19 Syndrome.

Post-COVID-19 syndrome is a complex of different symptoms, which results in a multisystemic impairment after the suffering from COVID-19 infection. The aim of the study was to reveal the clinical, laboratory, and gut disorders in patients with post-COVID-19 syndrome (n = 39) before and after taking part in the 14-day complex program of rehabilitation. A complete blood count, coagulation test, blood chemistry, biomarkers, and metabolites in serum samples, and gut dysbiosis were revealed in patients on the day of admission and after 14-day rehabilitation, in comparison with the variables of healthy volunteers (n = 48) or with reference ranges. On the day of discharge, patients noted an improvement in respiratory function, general well-being, and mood. At the same time, the levels of some metabolic (4-hydroxybenzoic, succinic, fumaric acids) and inflammatory (interleukin-6) variables, which were increased on admission, did not reach the level of healthy people during the rehabilitation program. Taxonomy disbalance was observed in patients' feces, namely, a high level of total bacterial mass, a decrease in the number of Lactobacillus spp., and an increase in pro-inflammatory microorganisms. The authors suggest that the post-COVID-19 rehabilitation program should be personalized, considering the patient's state together with not only the baseline levels of biomarkers, but also with the individual taxonomy of the gut microbiota.

Artifactual hypoglycaemia may be common in patients with soft tissue sarcoma who received pegfilgrastim-supported chemotherapy

BackgroundRecently, we identified artifactual hypoglycemia in patients with soft tissue sarcoma (STS) who received pegfilgrastim-supported chemotherapy. In the present study, we measured white blood cell count and fasting blood glucose levels after the administration of pegfilgrastim in patients with STS and showed the relationship between artifactual hypoglycemia and white blood cell count. PatientsA total of 19 patients were included in this study. The mean age of the patients was 54 years. They received chemotherapy and administration of pegfilgrastim. Pegfilgrastim was injected subcutaneously 48 h after chemotherapy. No patient had a history of diabetes mellitus. ResultsFifty-nine cycles were administered to 19 patients. One hundred and twenty-eight samples were obtained within one week after the of pegfilgrastim administration. Hypoglycemia was observed in 38 of the 13 patients. There were no symptoms of hypoglycemia in any patient. The white blood cell count in samples from patients with hypoglycemia was significantly higher than that in samples without hypoglycemia (p < 0.001). The median white blood cell count in samples with hypoglycemia was 29,415 and 3420 in samples without hypoglycemia. Age, sex, body mass index, performance status, and red blood cell count were not associated with hypoglycemia. White blood cell count was strongly negatively correlated with fasting blood glucose levels (Pearson's r: 0.786, 95% confidence interval: 0.844–0.709, p < 0.001). Of the 38 samples with hypoglycemia, 32 were measured within 2 days after pegfilgrastim administration. ConclusionIf a lack of symptoms due to hypoglycemia and leukocytes is confirmed, physicians should wait and identify the normalization of the level of glucose according to the neutrophil nadir following temporal leukocytes, which prevents further invasive examination for hypoglycemia.

Assessment of nitrate, trace elements and bacterial contamination of groundwater in ilora area of southwestern nigeria

Assessments of groundwater pollution parameters were carried out in groundwater samples collected from selected shallow hand-dug wells across Ilora township. The analysed parameters were nitrate, trace elements including, iron, cobalt, chromium, manganese, zinc, arsenic, cadmium and lead, and bacteria count in water; using spectrophotometric method, HM Metalyser 5000 and multiple tube techniques respectively. The pH of the samples was between 6.4 and 7.6 and TDS range was 50 - 640 mg/l. The concentration of nitrate (NO3) in water was 12.8 - 274 mg/l. For trace elements concentrations in µg/l ; iron (Fe): 150 – 880, Cobalt (Co): 1 – 100, Manganese (Mn): 0.01 - 140, Chromium (Cr): 0.01 – 0.31, Zinc (Zn): 1.86 - 9.97, Arsenic (As): 3.11 - 20.80, Cadmium (Cd): 0.71 - 4.76, Lead (Pb): 1.00 – 6.82. Based on the average concentration of the trace elements the order of abundance was Fe &gt; Co &gt; Mn &gt; As &gt; Zn &gt; Pb &gt; Cd &gt; Cr. Total coliform count (TCC) in groundwater samples were between 18 and 370 cfu/100mL. From the evaluation of the degree of association between the parameters, a moderate to strong positive relationship occurred between Fe/Mn (0.59), Fe/Cr (0.85), Fe/TC (0.56), NO3/Co (0.56), NO3/Mn (0.48), NO3/Cd (0.51) and Mn/Pb (0.85). Presence of coliform bacteria in the groundwater samples indicated fecal contamination from surface environment. Comparing the parameters with guideline standards for drinking water, most of the hand-dug wells are contaminated with nitrate, five wells were contaminated with either arsenic and/or cadmium, while water from some of the wells may have objectionable taste due to high iron content. The high values of cadmium and arsenic in some wells are harmful to human health and appropriate treatment is needed. For bacteria contamination, deeper wells are recommended, and the water should to be treated and boiled prior to consumption.&#x0D;

Analytical errors in nucleated red blood cell enumeration.

Enumeration of nucleated red blood cells (NRBCs) in peripheral blood of dogs and cats is performed by manual counting during blood film evaluation. Automated methods have increased precision and accuracy; however, most analyzers cannot distinguish leukocytes and NRBCs. The Sysmex XN-V Series may distinguish NRBCs and leukocytes; however, analytical errors occur. We aimed to investigate cases with discrepant automated and manual NRBC counts, and to evaluate reasons for analytical errors. Data from samples with increased NRBCs were collected retrospectively and compared with manual counts performed on blood films using Spearman's correlation, Passing-Bablok agreement analysis, and Bland-Altman comparisons. Precision of the automated method and interobserver agreement of manual counts were evaluated. Cases with discrepant results were investigated. Agreement between the methods was good at ≤1NRBC ×109 /L in dogs and cats, and inadequate at ≥1NRBC ×109 /L. The automated method demonstrated a negative proportional difference to the manual method. Precision was good for the automated method (overall CV 7.1%) and interobserver agreement for the manual method was poor overall (mean CV 27.3%, range 0%-106.1%). Inaccuracies in NRBC enumeration by the automated method occurred with high hematocrits, the mergence of the cell fragments and leukocyte clouds, and the presence of earlier erythroid precursors. NRBC enumeration by the WNR channel on the Sysmex XN-1000 V is precise and has good agreement with manual counts in canine and feline blood samples at ≤1NRBC ×109 /L. Manual film review is indicated for samples with ≥1NRBC ×109 /L, earlier erythroid precursors, samples from greyhounds and dehydrated patients, and if gating errors are noted.

ExoCounter Assays Identify Women Who May Develop Early-Onset Preeclampsia From 12.5 μL First-Trimester Serum by Characterizing Placental Small Extracellular Vesicles.

Preeclampsia is a major cause of maternal and perinatal morbidity and mortality worldwide. Identifying women with high risk of developing preeclampsia in early pregnancy remains challenging. Extracellular vesicles released from the placenta offer an attractive biomarker but have been elusive to quantify. Here, we tested ExoCounter, a novel device that immunophenotypes size-selected small extracellular vesicles <160 nm, for its ability to perform qualitative and quantitative placental small extracellular vesicles (psEV) analysis. To investigate disease-specific and gestational age-specific changes, we analyzed psEV counts in maternal plasma samples taken at each of the 3 trimesters from women who had (1) normal pregnancy (n=3); (2) women who developed early-onset preeclampsia (EOPE; n=3); and (3) women who developed late-onset preeclampsia (n=4) using 3 antibody pairs, CD10-placental alkaline phosphatase (PLAP), CD10-CD63, and CD63-PLAP. We further validated the findings in first-trimester serum samples among normal pregnancy (n=9), women who developed EOPE (n=7), and women who developed late-onset preeclampsia (n=8). We confirmed that CD63 was the major tetraspanin molecule coexpressed with PLAP-a known placental extracellular vesicles marker on psEV. Higher psEV counts for all 3 antibody pairs were detected in the plasma of women who developed EOPE than the other 2 groups in the first trimester, which persisted through the second and third trimesters. Significantly higher CD10-PLAP (P<0.01) and CD63-PLAP (P<0.01) psEV counts were validated in the serum of the first trimester of women who developed EOPE compared with normal pregnancy. Application of the ExoCounter assay developed here could identify patients at risk of developing EOPE in the first trimester, thereby providing a window of opportunity for early intervention.

Rapid detection of bacterial load in food samples using disposable respirometric sensor sachets

We describe a new sensor platform for simple on-site analysis of total aerobic viable counts (TVCs) in food samples, which uses disposable sealable plastic sachets with phosphorescent oxygen sensor inserts and liquid growth media. Food samples are collected, placed directly in the sachets, which are then sealed and incubated at 30 °C while monitoring (hourly or endpoint) sensor signals non-invasively with a commercial handheld reader FirestingO2. The growth of microbiota produces characteristic respiration profiles, from which sample initial TVC load is quantified: the Threshold Time (TT, in hours), when the sensor signal reaches the set signal threshold, is determined and calibration equation is applied to it to calculate sample TVC load. The initial calibration equation, which provides the conversion of measured TT values (hours) into TVC, was generated with pure Escherichia coli culture: log(CFU/g) = 8.30–0.60 *TT25 ° for signal threshold of 25 degrees phase. Another calibration equation, which provides a better representation of whole food microbiota, was generated with a panel of 90 different food samples: log(CFU/g) = 8.53–0.60 *TT25°. This simple sensor system shows good correlation with traditional plate counting TVC method (ISO 4833) and suitability for autonomous on-site or in-field operation. Time to result of 1–6 h provided by the sensor sachet system is more than seven time faster than for the standard method.

Randomized, Phase II study of pemetrexed plus bevacizumab versus pemetrexed alone after treatment with cisplatin, pemetrexed, and bevacizumab in advanced non-squamous, non-small cell lung cancer: TORG (thoracic oncology research group) 1321.

Cisplatin plus pemetrexed followed by pemetrexed is an efficacious platinum combination regimen for advanced non-squamous, non-small cell lung cancer (NSCLC). Data regarding the addition of bevacizumab, especially in maintenance treatment, are insufficient. Eligibility criteria included: no prior chemotherapy; advanced, non-squamous, NSCLC; performance status ≤1; and epidermal growth factor receptor mutation-negative. Patients (N = 108) received induction chemotherapy with cisplatin, pemetrexed, and bevacizumab every 3 weeks for four cycles, and tumor response was needed to confirm four-week response duration. Patients with at least stable disease were randomized to pemetrexed/bevacizumab or pemetrexed alone. The primary endpoint was progression-free survival (PFS) after induction chemotherapy. Myeloid-derived suppressor cell (MDSC) counts of peripheral blood samples were also analyzed. Thirty-five patients each were randomized to the pemetrexed/bevacizumab group and the pemetrexed alone group. PFS was significantly better in the pemetrexed/bevacizumab group than in the pemetrexed alone group (7.0 vs. 5.4 months, hazard ratio: 0.56 [0.34-0.93], log-rank p = 0.023). In patients with partial response to induction therapy, median overall survival was 23.3 months in the pemetrexed alone group and 29.6 months in the pemetrexed/bevacizumab group (log-rank p = 0.077). Pretreatment monocytic (M)-MDSC counts tended to be greater in the pemetrexed/bevacizumab group with poor PFS than in those with good PFS (p = 0.0724). Addition of bevacizumab to pemetrexed as maintenance therapy prolonged PFS in patients with untreated, advanced, non-squamous NSCLC. Furthermore, an early response to induction therapy and pretreatment M-MDSC counts may be related to the survival benefit of the addition of bevacizumab to the combination of cisplatin and pemetrexed.

PENGARUH KOREKSI POSTUR TERHADAP PENURUNAN NYERI PINGGANG BAWAH PADA MAHASISWA SEBAGAI DAMPAK KEGIATAN PEMBELAJARAN SECARA VIRTUAL

Sitting for long hours during virtual learning will cause a musculoskeletal disorder in the lower spine which is commonly known as low back pain.Interventions that can be done to treat low back pain are through posture correction exercises, which are exercises to correct unstable muscles, bad posture and muscle pain caused by changes in posture by teaching someone good posture.Objective: To determine the effect of posture correction on reducing low back pain in college students. Research design: pre-experimental using a "one-group pretest-posttest" design.The research population was all Physiotherapy students at the Jakarta III Polytechnic of the Ministry of Health.The results of the sample count were 17 people.The independent variable in this study was the posture correction exercise intervention.The dependent variable is low back pain.This research was conducted in April – September 2022. Data collection used a low back pain assessment instrument and then provided posture correction interventions.Data analysis was performed using univariate and bivariate.The results of the statistical test proved that there was a significant difference in the average lower back pain in college students between before and after the intervention (p = 0.0001).Suggestion: So that students can practice Posture Correction regularly, so that lower back pain will be felt even less.&#x0D; Keywords: Posture Correction, low back pain.

Assessment of indoor bioaerosol exposure using direct-reading versus traditional methods—potential application to home health care

Home healthcare workers (HHCWs) can be occupationally exposed to bioaerosols in their clients’ homes. However, choosing the appropriate method to measure bioaerosol exposures remains a challenge. Therefore, a systematic comparison of existing measurement approaches is essential. Bioaerosol measurements with a real-time, fluorescence-based Wideband Integrated Bioaerosol Sensor (WIBS) were compared to measurements with four traditional off-line methods (TOLMs). The TOLMS included optical microscopic counting of spore trap samples, microbial cultivation of impactor samples, qPCR, and next-generation sequencing (NGS) of filter samples. Measurements were conducted in an occupied apartment simulating the environments that HHCWs could encounter in their patients’ homes. Descriptive statistics and Spearman’s correlation test were computed to compare the real-time measurement with those of each TOLM. The results showed that the geometric mean number concentrations of the total fluorescent aerosol particles (TFAPs) detected with the WIBS were several orders of magnitude higher than those of total fungi or bacteria measured with the TOLMs. Among the TOLMs, concentrations obtained with qPCR and NGS were the closest to the WIBS detections. Correlations between the results obtained with the WIBS and TOLMs were not consistent. No correlation was found between the concentrations of fungi detected using microscopic counting and any of the WIBS fluorescent aerosol particle (FAP) types, either indoors or outdoors. In contrast, the total concentrations detected with microbial cultivation correlated with the WIBS TFAP results, both indoors and outdoors. Outdoors, the total concentration of culturable bacteria correlated with FAP-type AC. In addition, fungal and bacterial concentrations obtained with qPCR correlated with FAP types AB and AC. For a continuous, high-time resolution but broad scope, the real-time WIBS could be considered, whereas a TOLM would be the best choice for specific and more accurate microbial characterization. HHCWs’ activities tend to re-aerosolize bioaerosols causing wide temporal variation in bioparticle concentrations. Thus, the advantage of using the real-time instrument is to capture those variations. This study lays a foundation for future exposure assessment studies targeting HHCWs.

Relationship between hematologic parameters related to systemic inflammation and insulin resistance-associated metabolic parameters in women with polycystic ovary syndrome.

The aim of the present study was to evaluate the associations between hematologic parameters related to systemic inflammation and insulin resistance-associated metabolic parameters in women with polycystic ovary syndrome (PCOS). Eighty-two women between the ages of 18 and 35 years who were diagnosed with PCOS were included in this study. A 2-hour 75-g oral glucose tolerance test (OGTT) was administered to all study participants; fasting and postprandial glucose and insulin levels were measured simultaneously during the 2-hour OGTT. Hematologic parameters were derived from a standard complete blood count and a differential count of fasting-state blood samples. The correlations between hematologic parameters and insulin resistance-associated clinical and metabolic parameters were evaluated using the Spearman rank correlation and partial correlation coefficients. Hematologic parameters related to systemic inflammation were compared between the two groups, categorized by the presence or absence of insulin resistance. Significant differences in the absolute neutrophil count, absolute monocyte count, platelet count, and neutrophil-lymphocyte ratio were found between the insulin-resistant group and insulin-nonresistant group. Correlation analysis found that all hematological parameters, except for the platelet-lymphocyte ratio, were associated with at least one insulin resistance-associated metabolic parameter. However, these significant correlations between hematological and metabolic parameters were attenuated after controlling for the effects of other covariates using partial correlation analysis. The association between hematologic parameters indicative of systemic inflammation and insulin resistance-associated metabolic parameters seems to be strongly influenced by other anthropometric covariates in women with PCOS.

Passive swab versus grab sampling for detection of SARS-CoV-2 markers in wastewater

Early detection of the COVID-19 virus, SARS-CoV-2, is key to mitigating the spread of new outbreaks. Data from individual testing is increasingly difficult to obtain as people conduct non-reported home tests, defer tests due to logistics or attitudes, or ignore testing altogether. Wastewater based epidemiology is an alternative method for surveilling a community while maintaining individual anonymity; however, a problem is that SARS-CoV-2 markers in wastewater vary throughout the day. Collecting grab samples at a single time may miss marker presence, while autosampling throughout a day is technically challenging and expensive. This study investigates a passive sampling method that would be expected to accumulate greater amounts of viral material from sewers over a period of time. Tampons were tested as passive swab sampling devices from which viral markers could be eluted with a Tween-20 surfactant wash. Six sewersheds in Detroit were sampled 16–22 times by paired swab (4 h immersion before retrieval) and grab methods over a five-month period and enumerated for N1 and N2 SARS-CoV-2 markers using ddPCR. Swabs detected SARS-CoV-2 markers significantly more frequently (P < 0.001) than grab samples, averaging two to three-fold more copies of SARS-CoV-2 markers than their paired grab samples (p < 0.0001) in the assayed volume (10 mL) of wastewater or swab eluate. No significant difference was observed in the recovery of a spiked-in control (Phi6), indicating that the improved sensitivity is not due to improvements in nucleic acid recovery or reduction of PCR inhibition. The outcomes of swab-based sampling varied significantly between sites, with swab samples providing the greatest improvements in counts for smaller sewersheds that otherwise tend to have greater variation in grab sample counts. Swab-sampling with tampons provides significant advantages in detection of SARS-CoV-2 wastewater markers and are expected to provide earlier detection of new outbreaks than grab samples, with consequent public health benefits.

A novel material for the microbiological, oxidative, and color stability of salmon and chicken meat samples: Nanofibers obtained from sesame oil

Sesame oil nanofibers (diameter min: 286 max: 656nm), starting thermal degradation at 60 °C, were successfully obtained using the electrospinning technique in Türkiye. The distance, high voltage, and flow rate in electrospinning parameters were defined as 10 cm, 25 kV, and 0.065 mL/min. Mesophilic, psychrophilic bacteria, and yeast & molds counts of control group samples were higher (up to 1.21 log CFU/g) than those of salmon and chicken meat samples treated with sesame oil nanofibers. Thiobarbituric acid (TBA) value in control salmon meat samples stored for 8 days was defined between 0.56 and 1.48 MDA/kg (increase: 146%). However, the rise in TBA for salmon samples treated with sesame oil nanofibers was 21%. Also, nanofiber application for chicken samples limited the rapid oxidation up to 51.51% compared to control samples on the 8th day (p < 0.05). b* value (decline: 15.23 %) associated with rapid oxidation of the control group in salmon samples was more rapidly decreased than that of fish samples treated with sesame-nanofibers (b*: 12.01%) (p < 0.05). Chicken fillets b* values were more stable compared to control chicken meat samples for 8 days. Sesame oil-nanofiber application did not adversely affect the L* value color stability of all meat samples.

McAN: a novel computational algorithm and platform for constructing and visualizing haplotype networks.

Haplotype networks are graphs used to represent evolutionary relationships between a set of taxa and are characterized by intuitiveness in analyzing genealogical relationships of closely related genomes. We here propose a novel algorithm termed McAN that considers mutation spectrum history (mutations in ancestry haplotype should be contained in descendant haplotype), node size (corresponding to sample count for a given node) and sampling time when constructing haplotype network. We show that McAN is two orders of magnitude faster than state-of-the-art algorithms without losing accuracy, making it suitable for analysis of a large number of sequences. Based on our algorithm, we developed an online web server and offline tool for haplotype network construction, community lineage determination, and interactive network visualization. We demonstrate that McAN is highly suitable for analyzing and visualizing massive genomic data and is helpful to enhance the understanding of genome evolution. Availability: Source code is written in C/C++ and available at https://github.com/Theory-Lun/McAN and https://ngdc.cncb.ac.cn/biocode/tools/BT007301 under the MIT license. Web server is available at https://ngdc.cncb.ac.cn/bit/hapnet/. SARS-CoV-2 dataset are available at https://ngdc.cncb.ac.cn/ncov/. Contact: songshh@big.ac.cn (Song S), zhaowm@big.ac.cn (Zhao W), baoym@big.ac.cn (Bao Y), zhangzhang@big.ac.cn (Zhang Z), ybxue@big.ac.cn (Xue Y).

Joint Neural Denoising of Surfaces and Volumes

Denoisers designed for surface geometry rely on noise-free feature guides for high quality results. However, these guides are not readily available for volumes. Our method enables combined volume and surface denoising in real time from low sample count (4 spp) renderings. The rendered image is decomposed into volume and surface layers, leveraging spatio-temporal neural denoisers for both components. The individual signals are composited using learned weights and denoised transmittance. Our architecture outperforms current denoisers in scenes containing both surfaces and volumes, and produces temporally stable results at interactive rates.

Intramammary Infusion of Micronised Purified Flavonoid Fraction (MPFF) in Mastitis-Diagnosed Dairy Cows Naturally Infected by Staphylococcus spp. in the Late Lactation.

Infectious mastitis is the most prevalent health problem in dairy cattle that can result in permanent economic losses on dairy farms. The micronised purified flavonoid fraction (MPFF) is a biocompatible active polyphenolic compound derived from flavonoid glycosides which exhibits several antimicrobial, anti-inflammatory, and phlebotonic properties. The goal was to assess the effects of an alternative therapy for mastitis based on MPFF intramammary infusions in late lactation in dairy cows naturally infected by Staphylococcus spp. The California Mastitis Test (CMT scores) was performed to detect mastitis-positive quarters in twelve dairy farms. All cows were screened for immune response by measuring somatic cell counts (SCCs; cells/mL) in milk samples from each quarter. In addition, bacteriological identification, pathogenic bacterial isolates, and total bacterial counts (TBCs; CFU/mL) were assessed before (day 0, last milking day) and after (day 3 post-calving) MPFF application. Antimicrobial sensitivity patterns of the pathogenic isolated bacteria were evaluated. Finally, cure rates (%) were determined for each MPFF treatment. Around 15 mastitis-related genera were isolated. Staphylococcus aureus (25.2%) and coagulase-negative Staphylococci (CNS; 22.4%) were the most prevalent pathogens. No statistical differences were observed in SCCs and TBCs after low, medium, and high MPFF dose administration in S. aureus-positive mastitis cases (p > 0.05). However, differences were observed in SCCs and TBCs after medium and high MPFF dose administration in CNS-positive quarters (p < 0.05). The pathogenic bacteria isolate reduction after MPFF applications showed a dose-response fashion (p < 0.01) while isolates obtained from controls and low MPFF-treated quarters remained similar, irrespective of the pathogen (p > 0.05). Sensitivity patterns were variable, although S. aureus remained resistant, irrespective of the MPFF dose. However, CNS showed a dose-response sensitivity pattern. Finally, the cure rate (%) on day 3 post-partum improved significantly using medium and higher MPFF doses in CNS-positive quarters (p < 0.05). In conclusion, MPFF treatment was found to be more effective for CNS-positive cases in the late lactation due to noticeable dose-specific responses regarding somatic cells, bacterial counts, sensitivity patterns, and cure rates in dairy cattle.

Long-term study on wastewater SARS-CoV-2 surveillance across United Arab Emirates

Wastewater-based epidemiology (WBE) demonstrates an efficient tool to monitor and predict SARS-CoV-2 community distribution. Many countries across the world have adopted the technique, however, most of these studies were conducted for a short duration with a limited sampling size. In this study, long-term reliability and quantification of wastewater SARS-CoV-2 surveillance is reported via analyzing 16,858 samples collected from 453 different locations across the United Arab Emirates (UAE) from May 2020 to June 2022. The collected composite samples were first incubated at 60 °C followed by filtration, concentration, and then RNA extraction using commercially available kits. The extracted RNA was then analyzed by one-step RT-qPCR and RT-ddPCR, and the data was compared to the reported clinical cases. The average positivity rate in the wastewater samples was found to be 60.61 % (8.41–96.77 %), however, the positivity rate obtained from the RT-ddPCR was significantly higher than the RT-qPCR suggesting higher sensitivity of RT-ddPCR. Time-lagged correlation analysis indicated an increase in positive cases in the wastewater samples when the clinical positive cases declined suggesting that wastewater data are highly affected by the unreported asymptomatic, pre-symptomatic and recovering individuals. The weekly SARS-CoV-2 viral count in the wastewater samples are positively correlated with the diagnosed new clinical cases throughout the studied period and the studied locations. Viral count in wastewater peaked approximately one to two weeks prior to the peaks appearing in active clinical cases indicating that wastewater viral concentrations are effective in predicting clinical cases. Overall, this study further confirms the long-term sensitivity and robust approach of WBE to detect trends in SARS-CoV-2 spread and helps contribute to pandemic management.

Quantum advantage of Monte Carlo option pricing

Quantum computers have the potential to provide quadratic speedup for Monte Carlo methods currently used in various classical applications. In this work, we examine the advantage of quantum computers for financial option pricing with the Monte Carlo method. Systematic and statistical errors are handled in a joint framework, and a relationship to quantum gate error is established. New metrics are introduced for the assessment of quantum advantage based on sample count and optimized error handling. We implement and analyze a Fourier series based approach and demonstrate its benefit over the more traditional rescaling method in function approximation. Our numerical calculations reveal the unpredictable nature of systematic errors, making consistent quantum advantage difficult with current quantum hardware. Our results indicate that very low noise levels, a two-qubit gate error rate below 10−6, are necessary for the quantum method to outperform the classical one, but a low number of logical qubits (ca. 20) may be sufficient to see quantum advantage already.

Preventing swarm detection in extracellular vesicle flow cytometry: a clinically applicable procedure

BackgroundFlow cytometry is commonly used to detect cell-derived extracellular vesicles in body fluids such as blood plasma. However, continuous and simultaneous illumination of multiple particles at or below the detection limit may result in the detection of a single event. This phenomenon is called swarm detection and leads to incorrect particle concentration measurements. To prevent swarm detection, sample dilution is recommended. Since the concentration of particles differs between plasma samples, finding the optimal sample dilution requires dilution series of all samples, which is unfeasible in clinical routine. ObjectivesHere we developed a practical procedure to find the optimal sample dilution of plasma for extracellular vesicle flow cytometry measurements in clinical research studies. MethodsDilution series of 5 plasma samples were measured with flow cytometry (Apogee A60-Micro), triggered on side scatter. The total particle concentration between these plasma samples ranged from 2.5 × 109 to 2.1 × 1011 mL−1. ResultsSwarm detection was absent in plasma samples when diluted ≥1.1 × 103-fold or at particle count rates <3.0 × 103 events·s-1. Application of either one of these criteria, however, resulted in insignificant particle counts in most samples. The best approach to prevent swarm detection while maintaining significant particle counts was by combining minimal dilution with maximum count rate. ConclusionTo prevent swarm detection in a series of clinical samples, the measurement count rate of a single diluted plasma sample can be used to determine the optimal dilution factor. For our samples, flow cytometer, and settings, the optimal dilution factor is ≥1.1 × 102-fold, while the count rate is <1.1 × 104 events·s−1.

The MeerKAT Absorption Line Survey: Homogeneous continuum catalogues towards a measurement of the cosmic radio dipole

The number counts of homogeneous samples of radio sources are a tried and true method of probing the large-scale structure of the Universe, as most radio sources outside the Galactic plane are at cosmological distances. As such, they are expected to trace the cosmic radio dipole, an anisotropy analogous to the dipole seen in the cosmic microwave background (CMB). Results have shown that although the cosmic radio dipole matches the direction of the CMB dipole, it has a significantly larger amplitude. This unexplained result challenges our assumption of the Universe being isotropic, which can have large repercussions for the current cosmological paradigm. Though significant measurements have been made, sensitivity to the radio dipole is generally hampered by systematic effects that can cause large biases in the measurement. Here we assess these systematics with data from the MeerKAT Absorption Line Survey (MALS), a blind search for absorption lines with pointings centred on bright radio sources. With the sensitivity and field of view of MeerKAT, thousands of sources are observed in each pointing, allowing for the possibility of measuring the cosmic radio dipole given enough pointings. We present the analysis of ten MALS pointings, focusing on systematic effects that could lead to an inhomogeneous catalogue. We describe the calibration and creation of full band continuum images and catalogues, producing a combined catalogue containing 16 307 sources and covering 37.5 square degrees of sky down to a sensitivity of 10 μJy beam−1. We measure the completeness, purity, and flux recovery statistics for these catalogues using simulated data. We investigate different source populations in the catalogues by looking at flux densities and spectral indices and how they might influence source counts. Using the noise characteristics of the pointings, we find global measures that can be used to correct for the incompleteness of the catalogue, producing corrected number counts down to 100–200 μJy. We show that we can homogenise the catalogues and properly account for systematic effects. We determine that we can measure the dipole to 3σ significance with 100 MALS pointings.

Hyperbaric treatment of platelets is comparable to cold storage alone over 14 days.

Platelets stored at room temperature (22-24°C) for transfusion purposes have a shelf life of 5-7 days, or 72 h when stored refrigerated (1-6°C). The limited shelf life of platelet products severely compromises platelet inventory. We hypothesized that cold storage of platelets in 100% plasma using xenon gas under high pressure would extend shelf life to 14 days. Double apheresis platelet units were collected and split equally between two bags. One unit was placed in a hyperbaric chamber, pressurized to 4 bars with a xenon/oxygen gas mixture, and placed in a refrigerator for 14 days (Xe). The remaining unit was aliquoted into mini-bags (10 ml) for storage at room temperature (RTP) or in cold (CSP). Samples were assayed on days 5 (RTP) or 14 (Xe and CSP) for count, metabolism, clot strength, platelet aggregation, and activation markers. The platelet count in Xe samples was lower than that of RTP but significantly higher than CSP. Despite similar levels of glucose and lactate, the pH of Xe samples was significantly lower than CSP. Glycoprotein expression was better preserved by Xe storage compared to CSP, but no differences in activation were observed. Thromboelastography and aggregometry results were comparable between all groups. Cold storage of platelets in plasma with hyperbaric xenon provides no significant improvement in platelet function over cold storage alone. The use of a hyperbaric chamber and the slow off-gassing of Xe-stored units complicate platelet storage and delivery logistics.