Determination of seventeen major and trace elements in new float glass standards for use in forensic comparisons using laser ablation inductively coupled plasma mass spectrometry.

Consensus concentration values for seventeen (17) major and trace elements typically present in soda-lime glass manufactured using the "float " process and used in the quantitative analysis and forensic comparison of glass samples were determined using laser ablation (LA) micro sampling coupled to inductively coupled plasma mass spectrometry (ICP-MS). This is the first reporting of the chemical characterization of a new set of float glass intended for use as matrix-matched calibration standards in the forensic analysis and comparison of glass by LA-ICP-MS using a standard test method (ASTM E2927-16e1). Three Corning Float Glass Standards (CFGS) were manufactured at low, medium, and high concentrations of 32 elements typically encountered in float glass samples as found in forensic casework. This work describes an international collaboration among seven (7) laboratories to evaluate the homogeneity of the three glass materials and reports the consensus concentrations values of 17 elements at three concentration levels. Eight (8) sets of independent results from LA-ICP-MS analysis using the standard test method of analysis and one set of micro-X-ray Fluorescence Spectrometry (µXRF) data (using method ASTM E2926-17) resulted in typically <3% relative standard deviation (RSD) within each lab and < 5% RSDs among all labs participating in the study for the concentration ranges using sampling spots between 50 µm - 100 µm in diameter. These results suggest that the new calibration standards are homogeneous for most elements at the small sampling volumes (~ 90 µm deep by ~80 µm in diameter) reported and show excellent agreement among the different participating labs. Consensus concentration values are determined using a previously reported calibration standard (FGS 2) and checked with a NIST 1831 SRM®. A collaboration with National Institute of Standards and Technology (NIST) scientists to certify these glasses as SRMs, including the certification of the quantitative analysis of the minor and trace element content, for future distribution by NIST is ongoing.

A 30-year-old woman with chronic hives, intermittent fevers, and joint pain.

Chronic urticaria with concomitant systemic symptoms may be seen in several rheumatologic and autoinflammatory conditions. Although most of these conditions tend to improve with corticosteroids, symptoms often recur with dose tapering. The appearance of the rash in addition to the symptom pattern and laboratory data must be considered to differentiate potential causes. We presented a unique case of chronic urticaria with fevers and arthralgias. A diagnosis was made, and the patient had rapid improvement with targeted therapy.

Regional HIV knowledge hubs: a new approach by the health sector to transform knowledge into practice.

This study aims to introduce the knowledge hub (KH) as an initiative to facilitate transformation of knowledge into practice and to highlight the activity and limitations with this new policy. The study was conducted through a review of articles; expert views in this field were sought for further information. Regional human immunodeficiency virus (HIV) KHs were developed by the World Health Organization and GTZ. A series of activities including capacity building, development of training models, technical assistance, and application of studies are provided through these hubs. However, financial limitations are the main obstacle in achieving these aims. This piece of work introduces these HIV hubs in order to help countries, particularly developing countries, provide the support needed to fight the progression of HIV.

Cross-validation and evaluation of the performance of methods for the elemental analysis of forensic glass by µ-XRF, ICP-MS, and LA-ICP-MS.

Elemental analysis of glass was conducted by 16 forensic science laboratories, providing a direct comparison between three analytical methods [micro-x-ray fluorescence spectroscopy (µ-XRF), solution analysis using inductively coupled plasma mass spectrometry (ICP-MS), and laser ablation inductively coupled plasma mass spectrometry]. Interlaboratory studies using glass standard reference materials and other glass samples were designed to (a) evaluate the analytical performance between different laboratories using the same method, (b) evaluate the analytical performance of the different methods, (c) evaluate the capabilities of the methods to correctly associate glass that originated from the same source and to correctly discriminate glass samples that do not share the same source, and (d) standardize the methods of analysis and interpretation of results. Reference materials NIST 612, NIST 1831, FGS 1, and FGS 2 were employed to cross-validate these sensitive techniques and to optimize and standardize the analytical protocols. The resulting figures of merit for the ICP-MS methods include repeatability better than 5% RSD, reproducibility between laboratories better than 10% RSD, bias better than 10%, and limits of detection between 0.03 and 9 µg g(-1) for the majority of the elements monitored. The figures of merit for the µ-XRF methods include repeatability better than 11% RSD, reproducibility between laboratories after normalization of the data better than 16% RSD, and limits of detection between 5.8 and 7,400 µg g(-1). The results from this study also compare the analytical performance of different forensic science laboratories conducting elemental analysis of glass evidence fragments using the three analytical methods.

Correlation between age, emergency department length of stay and hospital admission rate in emergency department patients aged ≥70 years.

BACKGROUND: Interdisciplinary emergency departments (EDs) are confronted with trauma and nontrauma patients of any age group. Length of stay (LOS) and admission rates reflect both disease complexity and severity. OBJECTIVE: To evaluate LOS and admission rates in different age groups according to traumatic and nontraumatic etiologies. PATIENTS AND METHODS: During May 2011 a total of 4,653 adult patients (defined as ≥18 years old) seen in the ED of our municipal hospital were evaluated for their primary problem, Emergency Severity Index, LOS and admission rate. 1,841 trauma patients (mean age: 51.9 years; SD 22.5 years) and 2,812 nontrauma patients (mean age: 60.0 years; SD 20.4 years) were included. RESULTS: Median LOS in the ED was 1:41 h (trauma) and 1:52 h (nontrauma). Trauma patients aged ≥70 years spent more time in the ED than nontrauma patients of this age group (patients aged ≥70 years median: 2:08 vs. 1:56 h; p < 0.0001). However, no significant difference was found in patients aged <70 years (1:33 vs. 1:48 h; p = 0.64). Comparing older with younger patients, median LOS within the ED was about 8 min longer in nontrauma patients aged ≥70 years (p = 0.22) and about 35 min longer in trauma patients aged ≥70 years (p < 0.00001). CONCLUSIONS: The correlation between age and LOS is stronger for trauma patients, which might indicate a special need for geriatric expertise in elderly trauma ED patients. Thus an interdisciplinary approach including surgical and geriatric expertise may be advantageous.

Hybridization induced transparency in composites of metamaterials and atomic media.

We report hybridization induced transparency (HIT) in a composite medium consisting of a metamaterial and a dielectric. We develop an analytic model that explains HIT by coherent coupling between the hybridized local fields of the metamaterial and the dielectric or an atomic system in general. In a proof-of-principle experiment, we evidence HIT in a split ring resonator metamaterial that is coupled to α-lactose monohydrate. Both, the analytic model and numerical calculations confirm and explain the experimental observations. HIT can be considered as a hybrid analogue to electromagnetically induced transparency (EIT) and plasmon-induced transparency (PIT).

An interlaboratory study evaluating the interpretation of forensic glass evidence using refractive index measurements and elemental composition.

Seventeen laboratories participated in three interlaboratory exercises to assess the performance of refractive index, micro X-ray Fluorescence Spectroscopy (µXRF), and Laser Induced Breakdown Spectroscopy (LIBS) data for the forensic comparison of glass samples. Glass fragments from automotive windshields were distributed to the participating labs as blind samples and participants were asked to compare the glass samples (known vs. questioned) and report their findings as they would in casework. For samples that originated from the same source, the overall correct association rate was greater than 92% for each of the three techniques (refractive index, µXRF, and LIBS). For samples that originated from different vehicles, an overall correct exclusion rate of 82%, 96%, and 87% was observed for refractive index, µXRF, and LIBS, respectively. Special attention was given to the reporting language used by practitioners as well as the use of verbal scales and/or databases to assign a significance to the evidence. Wide variations in the reported conclusions exist between different laboratories, demonstrating a need for the standardization of the reporting language used by practitioners. Moreover, few labs used a verbal scale and/or a database to provide a weight to the evidence. It is recommended that forensic practitioners strive to incorporate the use of a verbal scale and/or a background database, if available, to provide a measure of significance to glass forensic evidence (i.e., the strength of an association or exclusion).

The use of LA-ICP-MS databases to calculate likelihood ratios for the forensic analysis of glass evidence.

Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) has been shown to be an excellent technique for the discrimination of glass originating from different sources and for the association of glass originating from the same source. Typically, a match criterion is used to compare the elemental profile of the known sample to a questioned sample and if the glass samples are determined to "match" this may be followed by the use of a verbal scale to report the forensic practitioner's conclusion. This approach has several disadvantages: a fixed match criterion suffers from the "fall-off-the-cliff effect," the rarity of an elemental profile is not taken into account, and the use of a verbal scale to assign a weight of evidence may be considered as subjective and can vary by examiner. An alternative approach includes the use of a continuous likelihood ratio that provides a quantitative measure of the value of the evidence in support of any hypothesis and accounts for the rarity of an elemental profile through the use of a glass database. In the present study, two glass databases were used to evaluate the performance of the likelihood ratio; the first database includes 420 automotive windshield samples, while the second database includes 385 glass samples from casework. The multivariate kernel model was used for the calculation of the likelihood ratio. However, this model led to unreasonably large (or small) likelihood ratios. Thus, a calibration step, using the Pool Adjacent Violators (PAV) algorithm, was necessary in order to limit the likelihood ratio to reasonable values. The calibrated likelihood ratio presented rates of misleading evidence of <1.5% (for LRs<1 when objects came from the same source), and of <1.0% (for LRs>1 when objects came from different sources), which improved over the analogous ASTM false inclusion and false exclusion rates previously reported. In addition, the likelihood ratio limited the magnitude of the misleading evidence, providing only weak to moderate support for the incorrect hypothesis. Finally, most of the pairs found to present LR>1 when objects originated from different sources were explained by similarity of manufacturer of the glass source.

Coronary artery vasospasm and cardiogenic shock as the initial presentation for eosinophilic granulomatosis with polyangiitis.

A 68-year-old woman presented to our hospital with unstable angina and was admitted for further evaluation. While hospitalized, she developed persistent angina with hypotension along with ST-segment elevation in leads V1-V2 along with lead aVR elevation on 12-lead electrocardiogram. Coronary angiography revealed diffuse multi-vessel coronary vasospasm most notably in the left anterior descending artery (LAD). Due to incomplete resolution of vasospasm with intracoronary verapamil and nitroglycerin, along with hemodynamic compromise requiring an intra-aortic balloon pump, percutaneous coronary intervention (PCI) of the LAD was performed. Clinical workup revealed hypereosinophlia and elevated IgE; diagnosis of eosinophilic granulomatosis with polyangiitis was confirmed with evidence of radiographic migratory pulmonary infiltrates and airway obstruction on spirometry. The patient had recurrent angina after PCI but her symptoms resolved fully after a course of corticosteroids. We attribute her refractory vasospastic angina to previously undiagnosed small/medium-vessel vasculitis. .

Spectrally wide-band terahertz wave modulator based on optically tuned graphene.

New applications in the realms of terahertz (THz) technology require versatile adaptive optics and powerful modulation techniques. Semiconductors have proven to provide fast all-optical terahertz wave modulation over a wide frequency band. We show that the attenuation and modulation depth in optically driven silicon modulators can be significantly enhanced by deposition of graphene on silicon (GOS). We observed a wide-band tunability of the THz transmission in a frequency range from 0.2 to 2 THz and a maximum modulation depth of 99%. The maximum difference between the transmission through silicon and GOS is Δt = 0.18 at a low photodoping power of 40 mW. At higher modulation power, the enhancement decreased due to charge carrier saturation. We developed a semianalytical band structure model of the graphene-silicon interface to describe the observed attenuation and modulation depth in GOS.

Forensic investigation of brick stones using instrumental neutron activation analysis (INAA), laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) and X-ray fluorescence analysis (XRF).

Brick stones collected from different production facilities were studied for their elemental compositions under forensic aspects using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), instrumental neutron activation analysis (INAA) and X-ray fluorescence analysis (XRF). The aim of these examinations was to assess the potential of these methods in forensic comparison analyses of brick stones. The accuracy of the analysis methods was evaluated using NIST standard reference materials (679, 98b and 97b). In order to compare the stones to each other, multivariate data analysis was used. The evaluation of the INAA results (based on the concentrations of V, Na, K, Sm, U, Sc, Fe, Co, Rb and Cs) using principal component analysis (PCA) and cluster analysis is presented as an example. The results derived from the different analytical methods are consistent. It was shown that elemental analysis using the described methods is a valuable tool for forensic examinations of brick stones.

Characterizing ablation and aerosol generation during elemental fractionation on absorption modified lithium tetraborate glasses using LA-ICP-MS.

The influence of sample matrix composition, absorption behavior and laser aerosol particle size distribution on elemental fractionation in laser ablation inductively coupled plasma mass spectrometry was studied for nanosecond laser ablation at a wavelength of 266 nm. To this end, lithium tetraborate glass samples with different iron oxide contents and trace amounts of a group of 11 elements were prepared synthetically. The samples were characterized in terms of optical absorbance, melting points, trace element concentrations and homogeneity. UV/VIS spectra showed that sample absorption rises with increasing Fe2O3 content. Crater depths and time-dependent particle size distributions were measured, and ablated and transported sample volumes were estimated. Furthermore, the laser aerosol was filtered using a particle separation device and transient ICP-MS signals were acquired with and without filtering the aerosol. The results demonstrate that the amount of ablated sample is related to the absorption coefficient of the sample and therefore to the optical penetration depth of the laser beam into the sample. The higher energy densities resulting from the shorter penetration depths result in smaller average particle sizes for highly absorbing samples, which allows more efficient transport to and atomization and excitation of the ablated material within the ICP. The particle size distribution changes continuously with ablation time, and larger particle fractions occur mainly at the beginning of the ablation, which leads to particle-related fractionation processes at the beginning of the transient signal. Exceeding a critical depth to diameter ratio, laser-related elemental fractionation processes occur. Changes in the volatile to non-volatile element intensity ratio after the aerosol is filtered indicate that particle size-related enrichment processes contribute to elemental fractionation.