Non-absorbing Surfaces Research Articles

AN INNOVATIVE FORMULATION OF PARAFFIN AND SILICONE OILS FOR THE CONTROL OF THE RED POULTRY MITE (Dermanyssus gallinae) – EXAMINATION OF THE EFFICIENCY UNDER LABORATORY CONDITIONS

The past decades of clinical practice in poultry farming are character-ized by inadequate control of one of the most important poultry ectopara-site, the red poultry mite (Dermanyssus gallinae). Therefore, the program for control of D. gallinae based exclusively ona physical mechanisms of action of acaricides has been developed in Serbia since 2012. By the beginning of 2017, a synergistic relationship between paraffi n and silicone oils was observed by our team, and its effi ciency in preventing the red poultry mite from respiring was examined. For laboratory examination the Petri dish and tin-box methods were used. Direct, full 1-minute exposure of adult mites to the recommended (15 and 20%) or even much lower concentration of the formulation resulted in 100% mortality aft er 24 hours. Subsequent 1-hour exposure (24 hours aft er application onto treated non-absorbent surface of adult mite) resulted in 100% mortality with the same concentrations. The long term eff ect depends on the surface quality. The concentrations of 15 and 20% provide 100% long-term eff ect aft er a 1-hour exposure period, and remains fully eff ective over the following 4-month period. In the following months (8 months), the formulation continues to work with a slightly lesser, however, still signifi cant eff ect. The formulation is most eff ective on a plastic surface, where the full eff ect is achieved with signifi cantly lower concentrations. The formulation has no eff ect on eggs; however, aft er the short development cycle is completed in the egg (2-6 days) and exit from the shell, the larva is immediately exposed to the eff ects of the formulation and eliminated. High effi ciency of the paraffi n and silicone oils formulation, which has been established in laboratory conditions, justifi es its use to the purpose of D. gallinae control in cages and equipment before fl ock settle-ment as well as in transport cages aft er cleaning and disinfection.

Improvement of blood loss volume estimation by paramedics using a pictorial nomogram: A developmental study

IntroductionTo propose and evaluate a nomogram to assist paramedics to visually estimate the external blood loss on a non-absorbent surface and to identify whether the nomogram improves visual estimation. MethodsThe study was a prospective, paired-control design (pre-training control group & post-training group), utilizing Emergency Medical Assistant (EMA) I and II trainees from the Hong Kong Fire Services Ambulance Command Training School. A nomogram (blood loss volume to area on a non-absorbent surface) was prepared to aid blood loss estimation. All participants estimated four scenarios of blood pools twice (A: 180mL; B: 470mL;C: 940mL; D: 1550mL) before and after using the nomogram. Every participant received two-minute training on how to use the nomogram correctly. The difference between the estimations and the actual volume in each scenario was calculated. The absolute percentage errors were used for direct comparison and identification of improvement between visual estimation and the use of the nomogram. ResultsSixty-one participants with an average of 3-year paramedic field experience were recruited by convenience sampling. In combining all scenarios, the median of absolute percentage error of 61 participants was 43% (95%CI 38.0–50.9%) in visual estimation, while it was 23% (95%CI 17.4–27.0%) when using the nomogram. There was a significant reduction in absolute percentage error between visual estimation and the use of the nomogram (p<0.0001). ConclusionThe nomogram significantly improved the estimation of external blood loss volume.

Influence of formwork material on transport properties of self-consolidating concrete near formed surfaces

This study aims at determining the influence of the formwork material on transport properties of concrete cover when using self-consolidating concrete (SCC). Two types of formwork were used. The plywood (PW) formwork material which is relatively rough and absorbent compared to the PVC material that has a very smooth and non-absorbent surface. A total of 17SCC and highly flowable concrete mixtures with wide range of slump flow and T50 values were investigated. The concrete was used to fill 400×500×200mm3 moulds made with either PVC or PW. Sorptivity tests were performed on core samples (100mm in diameter and 50mm in length) taken from the sides and center of the prepared moulds after 28days of moist curing. This paper presents new experimental method using image analysis to quantify the relative surface area of coarse aggregate along different sections near formed surfaces. Sorptivity of concrete near the surface cast against the PW formwork was found to be significantly lower than that of PVC one due to the decrease of local w/c and wall effect. The examination of packing density of coarse aggregate near PVC and PW surfaces showed limited wall effect near the PVC formwork and significant wall effect within a thickness comparable to the maximum size of coarse aggregate near the PW formwork.

Lumicyano – fluorescencyjny cyjanoakrylan

Lumicyano is a new reagent used to reveal fingermarks on non-porous and semi-porous surfaces. It can be applied in trace visualization process instead of cyanoacrylate and fluorescent dyes (in the case of nonabsorbent surfaces) or cyanoacrylate and dactyloscopic powders (in the case of semi-porous surfaces). Fingerprints are revealed in the traditional cyanoacrylate fuming chambers. The present work, the effectiveness of Lumicyano was investigated, in comparison to previously used sequences of laboratory techniques, i.e. cyanoacrylate + Basic Yellow 40 and cyanoacrylate + Black Ruby dactyloscopic powder.

The Reliability of Pattern Classification in Bloodstain Pattern Analysis, Part 1: Bloodstain Patterns on Rigid Non-absorbent Surfaces.

This study was designed to produce the first baseline measure of reliability in bloodstain pattern classification. A panel of experienced bloodstain pattern analysts examined over 400 spatter patterns on three rigid non-absorbent surfaces. The patterns varied in spatter type and extent. A case summary accompanied each pattern that either contained neutral information, information to suggest the correct pattern (i.e., was positively biasing), or information to suggest an incorrect pattern (i.e., was negatively biasing). Across the variables under examination, 13% of classifications were erroneous. Generally speaking, where the pattern was more difficult to recognize (e.g., limited staining extent or a patterned substrate), analysts became more conservative in their judgment, opting to be inconclusive. Incorrect classifications increased as a function of the negatively biasing contextual information. The implications of the findings for practice are discussed.

The use of micro computed tomography to ascertain the morphology of bloodstains on fabric

Very little is known about the interactions of blood and fabric and how bloodstains on fabric are formed. Whereas the blood stain size for non-absorbent surfaces depends on impact velocity, previous work has suggested that for fabrics the blood stain size is independent of impact velocity when the drop size is kept constant. Therefore, a greater understanding of the interaction of blood and fabric is required. This paper explores the possibility of using a micro computed tomography (CT) scanner to study bloodstain size and shape throughout fabrics. Two different fabrics were used: 100% cotton rib knit and 100% cotton bull drill. Bloodstains were created by dropping blood droplets from three heights; 500mm, 1000mm and 1500mm. Results from the CT scanner clearly showed the bloodstain shape throughout the fabric. The blood was found to form a diamond shaped stain, with the maximum cross-sectional area 0.3–0.5mm below the surface. The bloodstain morphology depended on both the impact velocity and fabric structure.

The morphological features of a 20 mcl blood stain

The objective of this work was to study blood stains of small volume (20 mcl). It was shown that the fall of a blood droplet from the height of 5 to 200 cm at the angle of 90 degrees on a smooth non-absorbing surface (glass) leaves round stains. Their size increases with increasing height of the fall. The character of the stain edges also depends on the height of the fall. The edges are even when the drops fall from the height of less than 20 cm but become wave-shaped with blunt projections when the height of the fall is increased to 30-90 cm. The fall from the height of 100 to 200 cm gives rise to the stains with the scalloped edges having the rectangular or nearly rectangular protrusions. From one to three additional Plateau drops can be observed near the main one.

Film-forming ability of flowable cement pastes and its application in mixture proportioning of pervious concrete

In this paper, the concept of paste film-forming ability is introduced as a parameter for mixture proportioning of pervious concrete. Two new test methods are also developed. The two methods characterize film-forming ability in two conditions. The first method characterizes the ability of a cement paste to form a stable film on a smooth nonabsorbent vertical surface. The paste thickness measured from this test is called, Ideal PasteThickness (IPT). The second test characterizes the ability of cement paste to adhere and remain on an aggregate surface; this paste thickness is called ActualPasteThickness (APT). The IPT can be used as a standardized parameter to evaluate the film-forming ability of cement pastes. The APT can be used to study the formation of cement paste films on pervious concrete aggregates. In this study IPT and APT of sixteen superplasticized cement pastes were evaluated. The pastes were prepared from four water to cement (w/c) ratios (0.23, 0.27, 0.32 and 0.37).

Pulmonary Toxicity of Perfluorinated Silane-Based Nanofilm Spray Products: Solvent Dependency

A number of cases of pulmonary injury by use of aerosolized surface coating products have been reported worldwide. The aerosol from a commercial alcohol-based nanofilm product (NFP) for coating of nonabsorbing surfaces was found to induce severe lung damage in a recent mouse bioassay. The NFP contained a 1H,1H,2H,2H-perfluorooctyl trialkoxysilane (POTS) and the effects were associated with the hydrolyzed forms of the silane; increase in hydrolyzation resulted in faster induction of compromised breathing and induction of lung damage. In this study, the impact of the solvent on the toxicity of POTS has been investigated. BALB/cA mice were exposed to aerosolized water-based NFPs containing POTS, and solutions of hydrolyzed POTS in methanol, ethanol, and 2-propanol, respectively. No acute respiratory effect was observed at exposure concentrations up to 110 mg/m³ with an aqueous solution of POTS. However, exposure to POTS in methanol resulted in a decrease of the tidal volume--an effect that did not resolve within the recovery period. After 27 min of exposure, the tidal volume had decreased by 25%, indicating partial alveolar collapse. For POTS in ethanol and 2-propanol, a 25% reduction of the tidal volume was observed after 13 and 9 min, respectively; thus, the tidal volume was affected by increase of the chain length. This was confirmed in vitro by investigating lung surfactant function after addition of POTS in different solvents. The addition of vaporized methanol, 2-propanol, or acetone to aerosolized POTS in methanol further exacerbated the tidal volume reduction, demonstrating that the concentration of vaporized solvent participated in the toxicity of POTS.

Evaluation of Low Trace DNA Recovery Techniques from Ridged Surfaces

The first step in the DNA profiling process is the recovery of DNA from the crime scene or item. Such surfaces can be varying with absorbent and non-absorbent surfaces. Ridged surfaces, such as those encountered on bottletops or firearms, are also common. Although low trace DNA or “touch DNA” is problematic in forensic casework, ridged surfaces should be a more effective surface for the recovery of such DNA due their abrasive nature. The aim of this study was to evaluate six recovery techniques; single wet swab, dry-wet double swab, wet-dry double swab, flocked swab, PCR square, and tape lifts. 36 falcon tubes with screw top lids were sterilised before DNA was deposited on the screw-top lids. Each of the recovery techniques were then utilised on 6 screw-top lids. All recovery media then underwent standard DNA extraction prior to DNA quantification by UV/Vis spectroscopy and quantitative PCR. The data indicated that the tape lifts recovered significantly more DNA from the ridged surface than the other techniques. There was no significant difference between the remaining 5 techniques, although on average, flocked swabs recovered the least amount. This suggested that the success in recovery of DNA is not down to the particular technique used, but down to the competence of the individual examiner and the amount of DNA deposited onto the surface.

Numerical simulations of scattering of light from two-dimensional rough surfaces using the reduced Rayleigh equation

A formalism is introduced for the non-perturbative, purely numerical, solution of the reduced Rayleigh equation for the scattering of light from two-dimensional penetrable rough surfaces. Implementation and performance issues of the method, and various consistency checks of it, are presented and discussed. The proposed method is found, within the validity of the Rayleigh hypothesis, to give reliable results. For a non-absorbing metal surface the conservation of energy was explicitly checked, and found to be satisfied to within 0.03\%, or better, for the parameters assumed. This testifies to the accuracy of the approach and a satisfactory discretization. As an illustration, we calculate the full angular distribution of the mean differential reflection coefficient for the scattering of p- or s-polarized light incident on two-dimensional dielectric or metallic randomly rough surfaces defined by (isotropic or anisotropic) Gaussian and cylindrical power spectra. Simulation results obtained by the proposed method agree well with experimentally measured scattering data taken from similar well-characterized, rough metal samples, or to results obtained by other numerical methods.

Molecular scatology: how to improve prey DNA detection success in avian faeces?

The analysis of prey DNA in faeces is a non-invasive approach to examine the diet of birds. However, it is poorly known how gut transition time, environmental factors and laboratory treatments such as storage conditions or DNA extraction procedures affect the detection success of prey DNA. Here, we examined several of these factors using faeces from carrion crows fed with insect larvae. Faeces produced between 30 min and 4 h post-feeding tested positive for insect DNA, representing the gut transition time. Prey detection was not only possible in fresh but also in 5-day-old faeces. The type of surface the faeces were placed on for these 5 days, however, affected prey DNA detection success: samples placed on soil provided the lowest rate of positives compared to faeces left on leaves, on branches and within plastic tubes. Exposing faeces to sunlight and rain significantly lowered prey DNA detection rates (17% and 68% positives in exposed and protected samples, respectively). Storing faeces in ethanol or in the freezer did not affect molecular prey detection. Extracting DNA directly from larger pieces of faecal pellets resulted in significantly higher prey detection rates than when using small amounts of homogenized faeces. A cetyltrimethyl ammonium bromide-based DNA extraction protocol yielded significantly higher DNA detection rates (60%) than three commercial kits, however, for small amounts of homogenized faeces only. Our results suggest that collecting faeces from smooth, clean and non-absorbing surfaces, protected from sunlight and rain, improves DNA detection success in avian faeces.

Recovery Efficiencies of Anthrax Spores and Ricin from Nonporous or Nonabsorbent and Porous or Absorbent Surfaces by a Variety of Sampling Methods*

The 2001 anthrax letter cases brought into focus the need to establish the most effective environmental sampling procedures. Results are presented from two studies aimed at establishing the best procedures for everyday surfaces likely to be contaminated after the release of environmentally stable bioaggressive agents, as exemplified by anthrax spores and ricin. With anthrax spores, contact plates, with mean retrieval rates of 28-54%, performed better than other methods by a wide margin for flat nonporous, nonabsorbent surfaces. They also proved best on flat porous, absorbent materials, although recoveries were low (<7%). For both agents, dry devices (swabs, wipes, Trace Evidence Collection Filters) had universally poor retrieval efficiencies with no significant differences between them. Among moistened devices (wipes, swabs, and Sample Collection and Recovery Devices), wipes were generally best, albeit with considerable cross-over among individual readings (highest mean recoveries for anthrax spores and ricin 5.5% and 2.5%, respectively, off plastic).

Fingerprint Powder Formulation based on Azure I1 Dye

A novel fingerprint-dusting composition based on an organic dye, azure 11, has been prepared. The proportion of the dye in the formulation is 1 per cent, the remaining being an adhesive mixture of meshed aluminum, boric acid, talc, and barium carbonate. The powder gives sharp and clear prints on a wide range of absorbent and non-absorbent surfaces, including multicoloured ones. Weak, chance prints may be detected under ultraviolet light.

Computer simulations for multiple scattering of light rays in systems of opaque particles

A new computer model for multiple light scattering in arbitrary systems of opaque diffusely scattering particles is considered. For ray tracing and scattering in such systems, the geometric optics approximation is used. Semi-infinite media and clusters with spherical and irregular shaped particles are investigated. The irregular particles are approximated with a discrete set of small triangular facets attached to each other. The particle surface is supposed to scatter by the Lambertian indicatrix. Scattering of the first six orders is considered, but the model can be effectively used for calculations of higher orders too. Phase-angle curves of scattering for media and clusters with different packing density are calculated. It is shown that the contributions of scattering orders rapidly diminish as the order grows even for non-absorbing particulate surfaces. Only the first scattering order shows the opposition effect and is rather sensitive to packing density. Higher orders do not show any features near zero phase angle. The contributions of high orders increase slightly, when the packing density increases. The form of particles is important mostly for the second scattering order. For clusters of particles both packing density and number of particles are important for phase function behavior. Clusters consisting of 100 particles show weak phase-angle dependences of high orders of scattering. These dependences become more prominent with increase of number of particles. Phase curves for spherical and cubic clusters are compared. It turns out that the influence of cluster shape is only a minor factor.

Measurement of Cholesterol and Triglycerides in Dried Serum and the Effect of Storage

Dried blood on filter paper has been found to be suitable in large-scale population screening programs (1)(2)(3), but to the best of our knowledge, dried blood or serum on filter paper has not been used for lipid measurements. In the present study, we evaluated the stability of cholesterol and triglycerides in serum dried on filter paper. Fifty-four patients coming to the centralized laboratory, CNC, All India Institute of Medical Sciences for lipid investigations were selected at random, and blood was collected by venipuncture into tubes without anticoagulant. Serum was separated within 2 h of collection. All procedures were in accordance with the ethics standards of our institution. An aliquot of each serum sample was analyzed immediately. Exact 10-μL replicates of the samples were also spotted onto 3M Whatman filter paper kept on a nonabsorbent surface (thermacol) and left at room temperature for 1 h for drying. The room temperature was 16–37 °C for the duration of the study. After drying, one aliquot was eluted and analyzed on the day of collection. The remaining filter discs were kept in a sealed plastic bag to protect them from dust and moisture and stored at room …

The Presumptive Reagent Fluorescein for Detection of Dilute Bloodstains and Subsequent STR Typing of Recovered DNA

A presumptive reagent for dilute blood detection other than luminol is fluorescein. The sensitivity of fluorescein approaches the sensitivity of detection levels of luminol. The fluorescein detection method offers the advantages of working in a lighted environment, and the reaction persists longer than luminol. A series of diluted bloodstains, ranging from neat to 1:1,000,000, was placed on a variety of substrates. Three sets were made per substrate. One set was exposed to fluorescein, one set was exposed to luminol, and one set served as an uncontaminated control. The fluorescein signal persisted longer than luminol. However, background staining for fluorescein was observed on some substrates within 30 s to 1 min, and no background staining was observed for luminol. Stains on non-absorbent surfaces were detectable at 1:100,000 dilutions, and stains on absorbent surfaces were detectable usually at no more than 1:100. The sensitivity of detection of fluorescein was comparable to that of luminol in this study. In all cases, where sufficient DNA was recovered, typeable results at all 13 core CODIS STR loci were obtained from treated bloodstains and controls. The results from STR typing indicate that there was no evidence of DNA degradation.

Fingerprint Enhancement Revisited and the Effects of Blood Enhancement Chemicals on Subsequent Profiler Plus™ Fluorescent Short Tandem Repeat DNA Analysis of Fresh and Aged Bloody Fingerprints

This study was aimed at determining the effect of seven blood enhancement reagents on the subsequent Profiler Plus fluorescent STR DNA analysis of fresh or aged bloody fingerprints deposited on various porous and nonporous surfaces. Amido Black, Crowle's Double Stain. 1,8-diazafluoren-9-one (DFO), Hungarian Red, leucomalachite green, luminol and ninhydrin were tested on linoleum, glass, metal, wood (pine, painted white), clothing (85% polyester/15% cotton, 65% polyester/35% cotton, and blue denim) and paper (Scott 2-ply and Xerox-grade). Preliminary experiments were designed to determine the optimal blood dilutions to use to ensure a DNA typing result following chemical enhancement. A 1:200 blood dilution deposited on linoleum and enhanced with Crowle's Double Stain generated enough DNA for one to two rounds of Profiler Plus PCR amplification. A comparative study of the DNA yields before and after treatment indicated that the quantity of DNA recovered from bloody fingerprints following enhancement was reduced by a factor of 2 to 12. Such a reduction in the DNA yields could potentially compromise DNA typing analysis in the case of small stains. The blood enhancement chemicals selected were also evaluated for their capability to reveal bloodmarks on the various porous and nonporous surfaces chosen in this study. Luminol. Amido Black and Crowle's Double Stain showed the highest sensitivity of all seven chemicals tested and revealed highly diluted (1:200) bloody fingerprints. Both luminol and Amido Black produced excellent results on both porous and nonporous surfaces, but Crowle's Double Stain failed to produce any results on porous substrates. Hungarian Red, DFO, leucomalachite green and ninhydrin showed lower sensitivities. Enhancement of bloodmarks using any of the chemicals selected, and short-term exposure to these same chemicals (i.e., less than 54 days), had no adverse effects on the PCR amplification of the nine STR systems surveyed (D3S 1358, HumvWA, HumFGA, D8S1179, D21S11, D18S51, D5S818, D13S317, D7S820) or of the gender determination marker Amelogenin. The intensity of the fluorescent signals was very similar and the allele size measurements remained constant and identical to those of untreated bloody fingerprints. No additional background fluorescence was noted. Continuous exposure (for 54 days) to two of the seven enhancement chemicals selected (i.e., Crowle's Double Stain and Hungarian Red) slightly reduced the amplification efficiency of the longer STR loci in profiles of fresh and 7 to 14-day-old bloodprints. This suggests that long-term exposure to these chemicals possibly affects the integrity of the DNA molecules. This study indicates that significant evidence can be obtained from fresh or aged bloody fingerprints applied to a variety of absorbent and nonabsorbent surfaces which are exposed to different enhancement chemicals for short or long periods of time. It also reaffirms that PCR STR DNA typing procedures are robust and provide excellent results when used in concert with fluorescence-based detection assays after fingerprint identification has taken place.

Blood loss estimation by out-of-hospital emergency care providers

Objectives. To evaluate emergency medical technicians' (EMTs') ability to estimate spilled blood volume and to determine whether limited training improves estimate accuracy and whether there is a difference in improvement comparing two different training methods. Methods. The study design was a single-blinded, clinical model, utilizing EMTs (basic, intermediate, and advanced) from a local commercial ambulance service. Participants estimated the volume of randomly selected volumes of packed red blood cells reconstituted to a normal hematocrit and poured onto three absorbent (carpet) and three nonabsorbent (vinyl) surfaces. Participants were then randomly assigned to one of two teaching groups. The sitegrp (n = 17) returned to the six testing sites and were told the actual blood volumes. The slidegrp (n = 16) were taught with slides of six similar blood spill sites. Both groups were provided with suggestions for making volume estimates. The same participants were then retested one month later using the same type of sites and six new blood volumes. Results. Thirty-three participants with an average of 7.5 years of prehospital care experience completed testing on both dates. Mean percent error {[(estimated volume - actual volume)/actual volume] ± 100} for all participants decreased from 65% ± 33% initially to 52% ± 20% after retesting (p < 0.05). Mean percent error was 74% ± 41% and 59% ± 20% for the sitegrp (p < 0.15) initially and after retesting, respectively. Mean percent error was 56% ± 17% and 45% ± 17% for the slidegrp (p < 0.05) initially and after retesting, respectively. Conclusion. Prehospital care providers are not accurate at estimating spilled blood volumes. This ability can be improved with limited education. Slides appear to be as effective as viewing actual spill sites.

The monitoring of contaminated impervious planar surfaces

The responses of several types of surface contamination monitor have been investigated for three typical working surfaces contaminated by three radionuclides commonly used in diagnostic or analytical biomedical applications. Of the three radionuclides, is an intermediate-energy gamma emitter, decays by electron capture, emitting low-energy x-rays, and is a moderate-energy beta emitter. For each radionuclide monitored values have generally been found to be within 30% of projected response, this being based on calibrations which make use of standard radionuclide sources and conditions. The several types of contaminated non-absorbent surface that have been investigated produce monitored values which for a given type of monitor and radionuclide cannot be differentiated from each other.