Simultaneous Sampling Research Articles

Skin wipe test: A simple, inexpensive, and fast approach in the diagnosis of cystic fibrosis.

To assess the performance of a newly developed skin wipe test (SWT) for the diagnosis of cystic fibrosis (CF). Spontaneously formed sweat from the forearm was wiped by a cotton swab moistened with 100 µL of deionized (DI) water and extracted into 400 µL of DI water (SWT). The conventional Macroduct sweat test (ST) was performed simultaneously. SWT samples of 114 CF patients, 76 healthy carriers, and 58 controls were analyzed by capillary electrophoresis with contactless conductivity detection and Cl- /K+ and (Cl- + Na+ )/K+ ion ratios were evaluated. Chloride concentrations from Macroduct ST were analyzed coulometrically. Analysis of 248 SWT samples and simultaneous Macroduct ST samples showed comparable method performance. Two ion ratios, Cl- /K+ and (Cl- + Na+ )/K+ , from the SWT samples and Cl- values from the ST samples were evaluated to diagnose CF. Sensitivity of the SWT method using the Cl- /K+ ratio (cutoff value 3.9) was 93.9%, compared to 99.1% when using the (Cl- + Na+ )/K+ ratio (cutoff value 5.0) and 98.3% in using Macroduct Cl- (cutoff value higher or equal to 60 mmol/L). The methods' specificities were 97.8%, 94.0%, and 100.0%, respectively. The developed SWT method with capillary electrophoretic analysis for CF diagnosis performs comparably to the conventional Macroduct ST. The SWT method is simple, fast, inexpensive, and completely noninvasive. Use of an ion ratio in obtained SWT samples is proposed as a new diagnostic parameter that shows significant promise in CF diagnostics.

Validation of the usefulness of 2-dimensional strain parameters to exclude acute rejection after heart transplantation: a multicenter study

Introduction and objectivesTwo-dimensional speckle-tracking echocardiography has emerged as a promising alternative to endomyocardial biopsy to rule out acute cellular rejection after orthotopic heart transplantation (OHT) in single center studies. In an original cohort, 15.5% and 17% of cutoff points for left ventricular global longitudinal strain (LVGLS) and free-wall right ventricular longitudinal strain, respectively, achieved 100% negative predictive value to exclude moderate or severe acute cellular rejection (ACR ≥ 2R). Our objective was to demonstrate the usefulness of speckle-tracking and validate these cutoff points in an external cohort. MethodsA prospective, multicenter study that included patients who were monitored during their first year after OHT was conducted. Echocardiographic studies analyzed by local investigators were compared with simultaneous paired endomyocardial biopsies samples. ResultsA total of 501 endomyocardial biopsy-echocardiographic studies were included in 99 patients. ACR≥2R was present in 7.4% of samples. LVGLS and free-wall right ventricular longitudinal strain were significantly reduced during ACR≥2R on univariate analysis. On multivariate analysis, LVGLS was independently associated with the presence of ACR≥2R. The original cutoff points demonstrated a negative predictive value of 94.3% to exclude ACR≥2R. ConclusionsThis study maintained a strong negative predictive value to exclude ACR≥2R after OHT and LVGLS was independently associated with the presence of ACR≥2R. We propose the use of speckle-tracking, especially LVGLS, as part of the noninvasive diagnosis and management of ACR.

Documentation of farmer perceptions and site‐specific properties to improve soil management on smallholder farms in Tanzania

AbstractIdentifying sustainable land management practices within smallholder agriculture is a challenge. This is partly driven by the challenge of documenting farmers' perspectives and practices in an integrated manner with site‐specific scientific soil assessment. Smartphone applications such as LandPKS provide new approaches to quantify site‐specific soil degradation and fertility but are untested with African farm management. We surveyed 578 households in rain‐fed maize (Zea mays) production areas of Tanzania using a stratified sampling frame to encompass a wide range of soils and agroecologies. A socio‐economic survey and simultaneous sampling in focal plots documented farmer characteristics, perspectives, and management practices, along with soil properties and crop yields. For a subsample of 58 households, we additionally assessed site‐specific field status with the LandPKS application. Farmer perceptions of change in soil fertility status were consistent with soil properties, for example, a field perceived to be declining in fertility was also likely to have low SOC (1.8% relative to 2.7% for increasing fertility). LandPKS provided additional novel insights into soil limitations such as identifying poor water infiltration areas consistently associated with farmer use of erosion control practices (water infiltration of 4 mm hr−1 vs 20 all other plots). This charts a way forward to address soil fertility and land degradation challenges through the use of smartphone applications to capture site‐specific conditions and farmer concerns as the basis for land management recommendations that are highly relevant and address local conditions.

Pediatric cyclical Cushing’s disease: a case report and literature review

The article presents a rare clinical case of cyclical Cushing’s disease in a child. A 9‑year‑old boy complained of excessive weight gain for 3 years. Obesity had been progressing for the following 2 years, and then the child lost 14 kg in 5 months. Growth hormone deficiency with regard to slow growth rate and hypogonadism due to maintaining of prepubertal gonadal size were excluded. Taking into account the history of obesity and low growth rate, the child was repeatedly examined for hypercortisolism. The urinary 24‑h cortisol excretion and the overnight dexamethasone suppression test didn’t confirm hypercortisolism in spite of detected impairment of the adrenocorticotropic hormone circadian rhythm. Resumption of weight gain was observed at the age of 13.5 years. The results of urinary 24‑h cortisol excretion confirmed hypercortisolism. Magnetic resonance imaging of pituitary was unremarkable. The boy underwent simultaneous bilateral selective blood sampling from the cavernous, inferior petrosal, and sigmoid sinuses. Significant positive adrenocorticotropic hormone gradient was registered in the left cavernous sinus compared to peripheral levels, so Cushing’s disease was diagnosed. Endoscopic transnasal surgery was conducted and abnormal tissue was resected. Histopathology revealed no pituitary adenoma. The article provides a brief review on the cyclic Cushing’s disease in children and the main reasons of negative results of histopathology.

Simultaneous fast joint sparse recovery for WSN and IoT applications

Joint sparse recovery aims to recover a number of sparse signals having joint sparsity from multiple compressed measurements. Such a problem is finding increasing applications in wireless sensor networks (WSN) and Internet of Things (IoT) where multiple sensors collect measurements. However, existing algorithms lack both reconstruction accuracy and speed at the same time. In this study, the authors propose a joint sparse recovery algorithm, simultaneous fast matching pursuit (SFMP), which exploits some of the concepts developed for the fast matching pursuit (FMP) algorithm. SFMP achieves significant improvement in reconstruction time and speed compared to other related existing algorithms. In contrast to related algorithms, support selection is performed efficiently as the number of selected atoms is adapted from an iteration to another. Furthermore, signal estimation is performed avoiding large matrix inversion as in related algorithms. Moreover, simultaneously pruning the estimated signals, results in removing incorrectly selected ones. Due to the efficient selection strategy and the simultaneous pruning operation, the algorithm shows significant improvement in reconstruction accuracy from noisy measurements. SFMP achieves significant speed improvement over simultaneous orthogonal matching pursuit, and significant accuracy improvement over simultaneous compressive sampling matching pursuit, requiring a much smaller number of measurements.

Investigation of Primary and Secondary Particulate Brown Carbon in Two Chinese Cities of Xi'an and Hong Kong in Wintertime.

Brown carbon (BrC), an aerosol carbonaceous matter component, impacts atmospheric radiation and global climate because of its absorption in the near-ultraviolet-visible region. Simultaneous air sampling was conducted in two megacities of Xi'an (northern) and Hong Kong (southern) in China in winter of 2016-2017. The aim of this study is to determine and characterize the BrC compounds in collected filter samples. Characteristic absorption peaks corresponding to aromatic C-C stretching bands, organo-nitrates, and C═O functional groups were seen in spectra of Xi'an samples, suggesting that the BrC was derived from freshly smoldering biomass and coal combustion as well as aqueous formation of anthropogenic secondary organic carbon. In Hong Kong, the light absorption of secondary BrC accounted for 76% of the total absorbances of BrC. The high abundance of strong C═O groups, biogenic volatile organic compounds (BVOCs) and atmospheric oxidants suggest secondary BrC was likely formed from photochemical oxidation of BVOCs in Hong Kong. Several representative BrC molecular markers were detected using Fourier transform ion cyclotron resonance mass spectrometry and their absorption properties were simulated by quantum chemistry. The results demonstrate that light absorption capacities of secondary anthropogenic BrC with nitro-functional groups were stronger than those of biogenic secondary BrC and anthropogenic primary BrC.

HYPO PERFUSION MARKERS AS THERAPEUTIC AND PROGNOSTIC TOOLS FOR SEPTIC PATIENTS

Background: Venous-to-arterial carbon dioxide difference (PvaCO2) and central venous oxygen saturation (ScvO2) may reflect the adequacy of blood flow during septic shock states. We sought to test whether the development of Pv-aCO2 and ScvO2 during the early phases of resuscitation is related to multi-organ dysfunction and outcomes in a population of septic shock patients resuscitated targeting the usual oxygen-derived and hemodynamic parameters. Aim of the Work: To assess the central venous-arterial carbon dioxide difference (Pv-aCO2) as a goal in goal directed therapy of sepsis resuscitation in comparison to central venous oxygen saturation (ScvO2) and to test for their prognostic values. Patients and Methods: This prospective observational study was performed in a 24-bed mixed ICU in a university-affiliated hospital. We examined all septic patients with a new episode admitted to the emergency room or proceeding from clinical wards during a 24-month period. After approval by Ethical Medical Committee and obtaining informed consent, simultaneous blood samples were collected from the central venous line and the arterial catheter for obtaining venous and arterial gases respectively at (T0), and 6 hours (T6), 12 hours (T12) and 24 hours (T24) later. Patients were classified into four groups; two group (30patients) (A1 and A2) according to PcvO2 gap and another two groups (30patients) (B1 andB2) according to Central venous oxygen saturation. Group (A1) Decreasing Pcv-aCO2 (high at T0, declining at T6), Group (A2) Persistently high Pcv-aCO2 (high at T0 and T6), Group (B1) Increasing Central venous oxygen saturation (less than 70% at T0, increasing at T6), Group (B2) Decreasing Central venous oxygen saturation (less than 70%at T0 and decreasing T6). Results: Sixty-eight septic critically ill patients were included in this study. However; 8 patients were excluded from the study. Among the included patients in the study, 3 patients were excluded as they developed acute coronary syndrome, 4 patients refused to complete the treatment and discharged against medical advice, and 1 patientdeveloped an ischemic cerebral vascular stroke. The final sample was therefore 60 patients. In this study, Central veno-arterial PCO2 gap and ScvO2 are considered as surrogate markers of the payment of the oxygen debt and early predictors of clinical outcome and organ dysfunction in the ICU. As regard the study, Central veno-arterial PCO2 gap is predictors for resuscitation in septic patients. As regard A Group, there was significant statistical difference between mortality and survival at T6, T12 and T24. However; regarding B Group, there was significant statistical difference between mortality and survival at T12 and T24. Also, this study shows that patients with persistently low ScvO2 are considered a good hypo perfusion marker for septic patients. Conclusion: Data support the hypothesis that persistence of high PCO2 Gap and low ScvO2 during the resuscitation of septic patients is associated with significant higher multi-organ dysfunction and poor outcomes in critically-ill patients. Recommendations: Future studies on a larger number of patients are needed and should test PCO2 Gap and ScvO2 as perfusion goals during early phases of the resuscitation of patients in septic shock to confirm its reliability.

Mercury Migration Behavior from Flue Gas to Fly Ashes in a Commercial Coal-Fired CFB Power Plant

Mercury (Hg) emissions from coal-fired power plants are of increasing concern around the world. In this study, field tests were carried out to understand the Hg emission characteristics and its migration behaviors in a commercial CFB boiler unit with the electricity generation capacity of 25 MW. This boiler is equipped with one electrostatic precipitator (ESP) and two fabric filters (FFs) in series for removing particulates from the flue gas. The EPA 30B method was used for simultaneous flue gas Hg sampling at the inlet of the ESP and the outlet of the second FF. The Hg mass balance in the range of 104.07% to 112.87% was obtained throughout the CFB unit by measuring the Hg contents in the feed fuel, the fly ash and the bottom ash, as well as in the flue gas at the outlet of the particulate control device (PCD) system. More than 99% of Hg contained in the feed fuel was captured by the fly ash, whilst less than 1% of Hg was remained in the bottom ash or the flue gas after passing the PCD system. The gaseous Hg obviously migrated from the flue gas to the fly ash in the air pre-heater, where the flue gas temperature decreased from 250 °C at the inlet to 120 °C at the outlet. Other gaseous Hg migrated from the flue gas to the fly ash in the PCD system, as the Hg concentrations in the flue gas ranged from 3.14 to 4.14 μg/m3 at the inlet of the ESP and ranged from 0.30 to 0.36 μg/m3 at the outlet of the second FF. The average Hg contents in the fly ash samples collected from the ESP, the first FF and the second FF were 912.3, 1313.6 and 1464.9 ng/g, respectively, while the mean particle diameters of these fly ash samples tend to decrease along the flow pass in the PCD system. Compared to large fly ash particles, smaller fly ash particles exhibit higher Hg capture performance due to their high unburned carbon (UBC) content and large specific surface area. The migration of gaseous Hg from the flue gas to the fly ash downstream of the CFB boiler unit was easier than that downstream of the PC boiler unit due to high UBC content and specific surface area.

Performance evaluation of a new three-in one diffusive sampler for monitoring NO2, SO2 and O3

A tailor-made diffusive sampler has been developed for the determination of nitrogen dioxide (NO2), sulfur dioxide (SO2) and ozone (O3) concentrations with a performance evaluation of the sampler being carried out under field and laboratory conditions. The most important characteristics of the sampler design is that simultaneous sampling of the three pollutants can be performed in one sampler. All the parts of the diffusive sampler are reusable after cleaning. These properties provide important advantages in terms of cost and practicality. Two alternative samplers, having long and short diffusion paths, have been designed. Extensive validation studies, including detection limit, precision, accuracy, recovery, shelf life, storage stability, comparison with commercial diffusive samplers, and the effects of shelter use were conducted in accordance with European Standards (EN). According to the validation results, all of the parameters evaluated for the diffusive sampler (for both long and short diffusion path designs) comply with the related standards and the sampler is expected to play an important role in the widespread monitoring of inorganic pollutants, since it is cheap, easy to use and deliverable within the country.

Absorption and Intestinal Metabolic Profile of Oleocanthal in Rats.

Oleocanthal (OLC), a phenolic compound of extra virgin olive oil (EVOO), has emerged as a potential therapeutic agent against a variety of diseases due to its anti-inflammatory activity. The aim of the present study is to explore its in vivo intestinal absorption and metabolism. An in situ perfusion technique in rats was used, involving simultaneous sampling from the luminal perfusate and mesenteric blood. Samples were analysed by UHPLC–MS–MS for the presence of oleocanthal (OLC) and its metabolites. OLC was mostly metabolized by phase I metabolism, undergoing hydration, hydrogenation and hydroxylation. Phase II reactions (glucuronidation of hydrogenated OLC and hydrated metabolites) were observed in plasma samples. OLC was poorly absorbed in the intestine, as indicated by the low effective permeability coefficient (2.23 ± 3.16 × 10−5 cm/s) and apparent permeability coefficient (4.12 ± 2.33 × 10−6 cm/s) obtained relative to the values of the highly permeable reference compound levofloxacin (LEV). The extent of OLC absorption reflected by the area under the mesenteric blood-time curve normalized by the inlet concentration (AUC) was also lower than that of LEV (0.25 ± 0.04 vs. 0.64 ± 0.03, respectively). These results, together with the observed intestinal metabolism, suggest that OLC has a moderate-to-low oral absorption; but higher levels of OLC are expected to reach human plasma vs. rat plasma.

Critical Particulate Contaminant(s) Generated during Arc Welding on Aluminum Alloys

Assessing exposure to particulate emissions during arc welding is an important consideration in assuring compliance with regulatory requirements. This study examined welding emissions during argon-shielded GMAW (MIG welding) processes involving aluminum alloys in a shipbuilding environment using traditional methods of air sampling (portable pumps and closed-face cassettes containing PVC filters.) Current requirements for exposure determination (inhalable, respirable and total particulates) necessitate three simultaneous samples, a very onerous imposition on worker safety and comfort. Application of a conversion factor published in the literature can considerably simplify this situation through use of a single sampler, the conventional closed face cassette. This approach provides a first-level means of evaluation and is especially useful where exposure levels are low compared to regulatory Exposure Limits. Assessment of exposure to chromium, magnesium and manganese may require additional consideration because of the necessity for simultaneous evaluation against TLVs for inhalable and respirable particulates and different oxidation states. Results strongly suggest that beryllium and/or chromium VI and possibly manganese dominate consideration about exposure and control measures (Critical Particulate Contaminant). This results from the difficulty of analysis created by the combination of extremely small Exposure Limits, presence of these elements in the alloy in trace to very small quantities and uncertainty associated with detectability in standard air samples. Resolving this question requires collection and analysis of bulk quantities of welding fume to improve the mathematics associated with detectability. Determination of the Critical Particulate Contaminant considerably simplifies future evaluation and focuses follow-up action in the appropriate direction.

Estimating the basic reproduction number of a pathogen in a single host when only a single founder successfully infects.

If viruses or other pathogens infect a single host, the outcome of infection may depend on the initial basic reproduction number R0, the expected number of host cells infected by a single infected cell. This article shows that sometimes, phylogenetic models can estimate the initial R0, using only sequences sampled from the pathogenic population during its exponential growth or shortly thereafter. When evaluated by simulations mimicking the bursting viral reproduction of HIV and simultaneous sampling of HIV gp120 sequences during early viremia, the estimated R0 displayed useful accuracies in achievable experimental designs. Estimates of R0 have several potential applications to investigators interested in the progress of infection in single hosts, including: (1) timing a pathogen’s movement through different microenvironments; (2) timing the change points in a pathogen’s mode of spread (e.g., timing the change from cell-free spread to cell-to-cell spread, or vice versa, in an HIV infection); (3) quantifying the impact different initial microenvironments have on pathogens (e.g., in mucosal challenge with HIV, quantifying the impact that the presence or absence of mucosal infection has on R0); (4) quantifying subtle changes in infectability in therapeutic trials (either human or animal), even when therapies do not produce total sterilizing immunity; and (5) providing a variable predictive of the clinical efficacy of prophylactic therapies.

Development of a highly sensitive sampler for atmospheric monitoring of 8-H ambient ozone concentrations

A new passive sampler reinforced with a composite membrane was developed to determine the 8-h ozone (O3) concentration in ambient air. The composite membrane's water absorption capacity and porosity values were found analyzing its surface morphology using Scanning Electron Microscopy (SEM).Ozone adsorption performance of this sampler was tested by a badge-type sampler and automated measurement results. The developed sampler gave results equivalent (R<sup>2</sup> = 0.85) to those of automated O3 monitors, and its experimental sampling rate was determined to be 55 cm<sup>3</sup>/min, approximately two times higher than the rate of the badge-type sampler. The detection limit obtained (5.3 μg/m<sup>3<.sup>, 8 h sampling) in the study was adequate for winter-period samplings where in the ozone concentration is low in urban and semi-urban areas. Multimedia sampling results revealed that the results of the developed passive sampler had a high repeatability (RSD < 20%). Passive samplers reinforced with composite membranes were tested by badge-type samplers performing simultaneous samplings in land conditions. Area sampling results indicated that badge-type samplers were not suitable for 8-h area samplings, but tube-type samplers could be used.

Influence of Macrobenthos (Meretrix meretrix Linnaeus) on Erosion‐Accretion Processes in Intertidal Flats: A Case Study From a Cultivation Zone

AbstractThe activity of benthic organisms can strongly influence sediment dynamics in an intertidal flat. However, few studies have conducted a quantitative assessments of the effect of benthic organisms on erosion‐accretion processes under field conditions. The aim of this study was to quantify the effects of the benthic clam Meretrix meretrix Linnaeus (M. meretrix) on bed erodibility and sediment erosion‐accretion processes in an intertidal flat. Within the cultivation zone at site A, M. meretrix is present in large numbers (up to 137 individuals per square meter). On the other hand, site B is located outside the cultivation zone. At this site, which is only 500 m away from site A alongshore, M. meretrix forms a sparse population with only 3.7 individuals per square meter. The results showed that the critical shear stress for erosion, denoted by τce, was 0.22 and 0.32 N/m2 at sites A and B, respectively, and the magnitudes of bed‐level change were significantly higher at site A than site B. These results reveal the large effect of M. meretrix on decreasing τce, augmenting the erosion rate when the bed shear stress due to combined currents and waves, denoted by τcw, was higher than τce, and conversely enhancing the accretion rate when τcw < τce. The changes induced in these parameters are likely to have a large impact on model predictions of bed erodibility, sedimentary processes, and morphological evolution. Thus, integrated field measurements of hydrodynamic and bed‐level changes, accompanied by simultaneous biological sampling, may help to improve the parameterization of hydro‐sedimentary and morphodynamic models for shallow‐water environments.

Composition and richness of monogonont rotifers from La Plata River Basin, South America

Abstract: We present here the first study that analyzed the composition and richness of rotifers of the entire La Plata River basin, the second largest in South America, based on simultaneous and standardized sampling. Fifteen large reservoirs and eight river stretches were selected in the upper, middle, and lower portions of the Paraná, Paraguay, and Uruguay Rivers, which are the major rivers of the La Plata basin. We took a total of 86 samples (open water habitats) in 2010. A mean of 27±11 species per sub-basin was found, with the highest richness in the Lower Paraná (41 species), followed by the Paranapanema (40 species) and Lower Uruguay (38 species). Low richness was observed in the Middle Uruguay and Middle Paraná. We found 106 species belonging to 21 families and two orders. The family with the highest number of species was Lecanidae (21), followed by Brachionidae (20), Trichocercidae (9), and Synchaetidae (8). The species with higher occurrences were Conochilus dossuarius, Kellicottia bostoniensis, Keratella americana, Keratella cochlearis and Hexarthra mira. New occurrences of rotifers were registered for Brazil (Colurella adriatica), São Paulo State (Enteroplea lacustris), and Argentina (Gastropus hyptopus, Harringia rousseleti and Lecane thienemanni). Spearman correlation between the number of species and physical and chemical variables demonstrated positive correlation with chlorophyll and temperature, and negative correlation with dissolved oxygen. We extend the distribution list for some native (Lecane ludwigii) and non-native species of rotifers (K. bostoniensis). We also list the monogonont rotifer species found at the sampling stations.

Clinical Significance of Serum TLR4 and NF-κB Levels in Neonatal Jaundice.

To explore the expression of serum TLR4 and NF-κB levels in neonatal jaundice. A total of 63 jaundice infants admitted to our hospital from January 2017 to January 2018 were enrolled into the experimental group (34 pathological jaundice infants and 29 physiological jaundice infants). The serum TLR4 level (0.5 ng/mL as positive expression) was determined by immunohistochemical staining, and the serum NF-κB level in peripheral blood was determined by ELISA. A total of 40 healthy infants with simultaneous blood sampling and physical examination were enrolled into the control group to measure the levels of TLR4 and NF-κB which were compared between the two groups. The levels of serum TLR4 and NF-κB in the infants in the experimental group were higher than those in normal newborns in the same period, the difference between the two groups was statistically significant (p < 0.05), and the levels of TLR4 and NF-κB showed a gradual downtrend after treatment. TLR4 expressions were positive in pathologic and physiologic jaundice infants of the experimental group, and negative in the control group. The correlation analysis showed that the elevated levels of TLR4, NF- kb, IL-Iβ, and TNF-α were risk factors for jaundice. The elevated levels of TLR4 and NF-κB are the main factors of neonatal jaundice. TLR4, NF- kb, IL-Iβ, and TNF-α are closely related to the onset of jaundice, which can be used as an important marker in clinical diagnosis of neonatal jaundice.

Cyclostationary Characterization of Radiated Emissions in Digital Electronic Devices

Stochastic electromagnetic fields originating from processes in digital circuitry affect the operation of the circuit, increase the error rate in the transmission of digital signals, degrade the circuit's performance, yield malfunction of the system or even lead to a complete failure of the system's operation. Interference from stochastic fields are not only disruptive but are becoming more common due to the increasing complexity of modern electronics. Stochastic electromagnetic fields under common circumstances are due to a mixture of emissions from different sources, which makes a quantification of stochastic fields very challenging. Since digital signals are clocked, the ensemble averages of the electromagnetic field transients representing the digital signal exhibit a periodic time dependence with the period of the clock interval. The probabilistic model of the cyclostationary random process was composed by appropriate transformations of the initial discrete random process of the binary symbols. Exploiting the cyclostationary characteristics of stochastic fields greatly simplifies their analysis. The physical signal propagating along the transmission line is considered also a source of the radiating electromagnetic field which preserves the cyclostationary properties of the binary sequence. The stochastic process of the measured near-field emissions inherits probability characteristicsfrom the random process of the physical signal in the transmission line. This paper presents an approach for quantifying emissions and coupling of stochastic fields using their cyclostationary properties. For practical evaluation of cyclostationary characteristics the statistical cyclic averaging of the measured signals are used. The important feature of the statistical cyclic averaging procedure is its capability to distinguish cyclostationary signals from a mixture of stochastic processes such as stationary noise with deterministic signals and even from other cyclostationary signals with distinct cyclic frequencies. The measurement setup for observing electromagnetic emissions from printed circuit boards (PCBs) hosting digital electronic devices comprises an automated positioning system with a scanning near-field probe attached to the moving scanner head. This scanning near-field probe and a properly position fixed or also movable reference probe are connected to the inputs of a multi-channel digital oscilloscope for simultaneous and synchronous sampling and registering of the magnetic field components. The registered data from the oscilloscope was transferred to a data acquisition computer. After the postprocessing procedure, the spatial localization of distributed radiating sources on the surface of the PCB was performed in conjunction with determination of their average power characteristics and specified cyclic frequencies. The proposed cyclic averaging was applied to the spatial separation of radiating sources with different bit rates and for the quantitative characterization of crosstalk and coupling between transmission lines carrying the data sequencesand subsequent estimation of bit error rate (BER) caused by the crosstalk using their cyclostationary properties.

Performance of StatSensor Point-of-Care Device for Measuring Creatinine in Patients With Chronic Kidney Disease and Postkidney Transplantation.

Background:The StatSensor is a point-of-care device which measures creatinine in capillary whole blood. Previous studies reported an underestimation of the creatinine measurements at high creatinine concentrations and were performed in the prestandardization era for creatinine.Objective:This accuracy-based study evaluates the use of this device in kidney-transplanted patients and those with chronic kidney disease (CKD).Design:Cross-sectional diagnostic accuracy study.Setting:Nephrology outpatient clinic in an urban tertiary center.Participants:Adults with CKD or a functioning kidney transplant.Measurements:Duplicate StatSensor creatinine measurements were performed on capillary whole blood samples collected by direct fingerstick and SAFE-T-FILL collection device. Results were compared with simultaneous venous blood sampling for serum and plasma creatinine measured by an enzymatic method on the Roche Integra 400 mainframe analyzer with traceability to the ID-GC-MS (isotope dilution gas chromatography mass spectrometry) reference method.Methods:Deming regression, Pearson correlation coefficient, and Bland-Altman analysis were used to assess accuracy and comparability between capillary whole blood measured by StatSensor and plasma creatinine measured by routine analyzer with traceability to the reference method. Estimated glomerular filtration (eGFR) rates were calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation and concordance with Kidney Disease Improving Global Outcomes (KDIGO) CKD stage classification was evaluated.Results:There were 60 participants (mean age = 61.9 ± 15.0 years, 55% men, 33% transplant, mean plasma creatinine = 137 ± 59 µmol/L). Bland-Altman analysis indicated a positive mean bias of 12.7 µmol/L between StatSensor fingerstick creatinine measurement and plasma creatinine. Comparison of eGFR (CKD-EPI) calculated from the StatSensor fingerstick creatinine versus plasma creatinine showed misclassification across all KDIGO CKD stages. Postanalytical correction of the bias did not improve misclassifications. The use of mean of duplicate StatSensor creatinine results did not improve performance compared with the use of singlet results.Limitations:Single center, limited participant numbers.Conclusions:The results of our study suggest that the limiting characteristics of the StatSensor device are not only bias, but also imprecision. The level of imprecision observed may influence clinical decision-making and limit the usefulness of StatSensor as a CKD screening tool. If choosing to utilize it for either screening for or monitoring CKD, it is essential that clinicians understand the limitations of point-of-care devices and apply this knowledge to test interpretation.

Relationship between vasospasm and serum chromogranin a levels in an animal subarachnoid haemorrhage model

Aim In that study, searching Chromogranin A levels on vasospasm in experimental subarachnoid heamorrhage (SAH) model was aimed. Material and methods Sixteen Wistar Albino male rats were used in study. Two groups are formed; first was consisting of 8 rats that experimental SAH was performed on them, second group was control group that nothing was done. Animals were sacrified fourtyeight hours later subarachnoid heamorrhage was occured. Peripheral venous blood samples were taken from the experimental group before SAH formation, 15 minutes, 75 minutes after experimental SAH formation and 48 hours as peak of vasospasm. Simultaneous peripheral venous blood samples were also collected from the control group. Blood samples were biochemically evaluated after centrifugation and serum Chromogranin A levels were studied. Results Serum chromogranin A levels increased statistically significant (p 0,05) at the 15th minute after SAH, as the samples obtained from the experimental and control groups were anticipated as a result of the statistical analysis of the data after the biochemical examinations. Conclusion In all these findings, we concluded that Chromogranin A could be used as a marker for the investigation of endocrine stress in the early period of post-SAH vasospasm and it could be proved by more studies.

Multi-Channel and Simultaneous Data Acquisition System for Magnetic Tensor Detection

This paper reports the design of a multi-channel and simultaneous data acquisition system(MSDAS). It can collect 12-channel magnetic induction component signals with magnetic tensor information rapidly and simultaneously. The STM32F103RCT6 and a 16-bit AD7606 are used as the MSDAQ’s microcontroller and the analog-to-digital(A/D) converter, respectively. Moreover, FATFS file system and TCP/IP protocol are integrated such that the MSDAS is capable of local storage and network simultaneous data transmission in real time. Experiments show that MSDAS can achieve data acquisition error ≤0.5% with the simultaneous sampling rate up to 500Hz. It is verified that the measurement results of magnetic tensor are basically consistent with the theory.