Structural and Photoluminescence Characterization of Oxyfluorides for Phosphor Applications.

ConspectusRare-earth-containing phosphors were crucial to the advances made to compact fluorescent lamps (CFLs), which assisted in protecting a widely used halophosphate phosphor from degrading after exposure to a high ultraviolet flux. The CFL phosphors are often coated twice by depositing a light coat of rare-earth-containing phosphors over the inexpensive halophosphate phosphor, which generates white light with high efficacy and a good color rendering index and possesses a balance between phosphor cost and performance. Costs of phosphors can be mitigated by requiring lower rare-earth ion concentrations or by completely eliminating rare-earth ions, which was one of the main goals of investigating the oxyfluorides Sr3AlO4F and Ba2SrGaO4F as potential phosphors. Changes in the Sr3AlO4F and Ba2SrGaO4F structures were studied using high-resolution neutron diffraction annealing these materials in 5%H2/95%Ar and 4%H2/96% Ar, respectively. Annealing in these atmospheres causes self-activated photoluminescence (PL) to occur under 254 nm light, which makes them ideal materials for rare-earth-free CFL phosphors. Additionally, these hosts possess two distinct sites for isovalent or aliovalent substitution of Sr denoted as the A(1) and A(2) sites. Ga3+ can be substituted for Al3+ at the M site, which is known to have an impact on the self-activated PL emission color. The structural distortions noted included closer packing in the FSr6 octahedrons and AlO4 tetrahedrons in the Sr3AlO4F structure as compared to in air-annealed samples, which show no PL emission. Temperature-dependent studies reveal that both the air- and reductively annealed samples have identical thermal expansion within this temperature range (3-350 K). High-resolution neutron diffraction at room temperature confirmed the tetragonal structure (I4/mcm) for Ba2SrGaO4F, a novel material in the Sr3AlO4F family of materials, has been synthesized via a solid-state method. Analysis of the refined Ba2SrGaO4F structure at room temperature revealed expansion in the lattice parameters and its polyhedral subunits between the reductively annealed and air-annealed samples, which are correlated with the PL emission. Previous studies related to the application of these host structure types revealed that they have potential as commercial solid-state lighting phosphors due to their ability to resist thermal quenching as well as accommodate various levels of substitutions that will assist with color tunability.

Complexity of human death: its physiological, transcriptomic, and microbiological implications.

Human death is a complex, time-governed phenomenon that leads to the irreversible cessation of all bodily functions. Recent molecular and genetic studies have revealed remarkable experimental evidence of genetically programmed cellular death characterized by several physiological processes; however, the basic physiological function that occurs during the immediate postmortem period remains inadequately described. There is a paucity of knowledge connecting necrotic pathologies occurring in human organ tissues to complete functional loss of the human organism. Cells, tissues, organs, and organ systems show a range of differential resilience and endurance responses that occur during organismal death. Intriguingly, a persistent ambiguity in the study of postmortem physiological systems is the determination of the trajectory of a complex multicellular human body, far from life-sustaining homeostasis, following the gradual or sudden expiry of its regulatory systems. Recent groundbreaking investigations have resulted in a paradigm shift in understanding the cell biology and physiology of death. Two significant findings are that (i) most cells in the human body are microbial, and (ii) microbial cell abundance significantly increases after death. By addressing the physiological as well as the microbiological aspects of death, future investigations are poised to reveal innovative insights into the enigmatic biological activities associated with death and human decomposition. Understanding the elaborate crosstalk of abiotic and biotic factors in the context of death has implications for scientific discoveries important to informing translational knowledge regarding the transition from living to the non-living. There are important and practical needs for a transformative reestablishment of accepted models of biological death (i.e., artificial intelligence, AI) for more precise determinations of when the regulatory mechanisms for homeostasis of a living individual have ceased. In this review, we summarize mechanisms of physiological, genetic, and microbiological processes that define the biological changes and pathways associated with human organismal death and decomposition.

COVID-19 and brain-heart-lung microbial fingerprints in Italian cadavers.

Introduction: The fact that SARS-CoV-2, the coronavirus that caused COVID-19, can translocate within days of infection to the brain and heart and that the virus can survive for months is well established. However, studies have not investigated the crosstalk between the brain, heart, and lungs regarding microbiota that simultaneously co-inhabit these organs during COVID-19 illness and subsequent death. Given the significant overlap of cause of death from or with SARS-CoV-2, we investigated the possibility of a microbial fingerprint regarding COVID-19 death. Methods: In the current study, the 16S rRNA V4 region was amplified and sequenced from 20 COVID-19-positive and 20 non-COVID-19 cases. Nonparametric statistics were used to determine the resulting microbiota profile and its association with cadaver characteristics. When comparing non-COVID-19 infected tissues versus those infected by COVID-19, there is statistical differences (p < 0.05) between organs from the infected group only. Results: When comparing the three organs, microbial richness was significantly higher in non-COVID-19-infected tissues than infected. Unifrac distance metrics showed more variance between control and COVID-19 groups in weighted analysis than unweighted; both were statistically different. Unweighted Bray-Curtis principal coordinate analyses revealed a near distinct two-community structure: one for the control and the other for the infected group. Both unweighted and weighted Bray-Curtis showed statistical differences. Deblur analyses demonstrated Firmicutes in all organs from both groups. Discussion: Data obtained from these studies facilitated the defining of microbiome signatures in COVID-19 decedents that could be identified as taxonomic biomarkers effective for predicting the occurrence, the co-infections involved in its dysbiosis, and the evolution of the virus.

Bridging Disciplines: Applications of Forensic Science and Industrial Hemp.

Forensic laboratories are required to have analytical tools to confidently differentiate illegal substances such as marijuana from legal products (i.e., industrial hemp). The Achilles heel of industrial hemp is its association with marijuana. Industrial hemp from the Cannabis sativa L. plant is reported to be one of the strongest natural multipurpose fibers on earth. The Cannabis plant is a vigorous annual crop broadly separated into two classes: industrial hemp and marijuana. Up until the eighteenth century, hemp was one of the major fibers in the United States. The decline of its cultivation and applications is largely due to burgeoning manufacture of synthetic fibers. Traditional composite materials such as concrete, fiberglass insulation, and lumber are environmentally unfavorable. Industrial hemp exhibits environmental sustainability, low maintenance, and high local and national economic impacts. The 2018 Farm Bill made way for the legalization of hemp by categorizing it as an ordinary agricultural commodity. Unlike marijuana, hemp contains less than 0.3% of the cannabinoid, Δ9-tetrahydrocannabinol, the psychoactive compound which gives users psychotropic effects and confers illegality in some locations. On the other hand, industrial hemp contains cannabidiol found in the resinous flower of Cannabis and is purported to have multiple advantageous uses. There is a paucity of investigations of the identity, microbial diversity, and biochemical characterizations of industrial hemp. This review provides background on important topics regarding hemp and the quantification of total tetrahydrocannabinol in hemp products. It will also serve as an overview of emergent microbiological studies regarding hemp inflorescences. Further, we examine challenges in using forensic analytical methodologies tasked to distinguish legal fiber-type material from illegal drug-types.

DNA-binding and physical studies of Pt(4'-NR2-trpy)CN+ systems (trpy = 2,2':6',2''-terpyridine).

This paper focuses on DNA-binding interactions exhibited by Pt(dma-T)CN(+), where dma-T denotes 4'-dimethylamino-2,2':6',2''-terpyridine, and includes complementary studies of the corresponding pyrr-T complex, where pyrr-T denotes 4'-(N-pyrrolidinyl)-2,2':6',2''-terpyridine. The chromophores are useful for understanding the interesting and rather intricate DNA-binding interactions exhibited by these and related systems. One reason is that the terpyridine ligands employed provide intense visible absorption and enhanced photoluminescence signals. Incorporating cyanide as a coligand further aids analysis by suppressing covalent binding. Physical methods utilized include X-ray crystallography for structures of the individual inorganic complexes. Viscometry as well as spectral studies of the absorbance, emission, and circular dichroism (CD) yield information about interactions with a variety of DNA hosts. Although there is no sign of covalent binding under the conditions used, most hosts exhibit two phases of uptake. Under conditions of high loading (low base-pair-to-platinum ratios), the dma-T complex preferentially binds externally and aggregates on the surface of the host, except for the comparatively rigid host [poly(dG-dC)]2. Characteristic signs of the aggregated form include a bisignate CD signal in the charge-transfer region of the spectrum and strongly bathochromically shifted emission. When excess DNA is present, however, the complex shifts to intercalative binding, preferentially next to G[triple bond]C base pairs if available. Once the complex internalizes into DNA it becomes virtually immune to quenching by O2 or solvent, and the emission lifetime extends to 11 micros when [poly(dI-dC)]2 is the host. On the other hand, the host itself becomes a potent quenching agent when G[triple bond]C base pairs are present because of the reducing strength of guanine residues.

Development and validation of the AmpFlSTR Yfiler PCR amplification kit: a male specific, single amplification 17 Y-STR multiplex system.

In the past 5 years, there has been a substantial increase in the use of Y-short tandem repeat loci (Y-STRs) in forensic laboratories, especially in cases where typing autosomal STRs has met with limited success. The AmpFlSTR Yfiler PCR amplification kit simultaneously amplifies 17 Y-STR loci including the loci in the "European minimal haplotype" (DYS19, DYS385a/b, DYS389I, DYS389II, DYS390, DYS391, DYS392, and DYS393), the Scientific Working Group on DNA Analysis Methods (SWGDAM) recommended Y-STR loci (DYS438 and DYS439), and the highly polymorphic loci DYS437, DYS448, DYS456, DYS458, Y GATA H4, and DYS635 (formerly known as Y GATA C4). The Yfiler kit was validated according to the FBI/National Standards and SWGDAM guidelines. Our results showed that full profiles are attainable with low levels of male DNA (below 125 pg) and that under optimized conditions, no detectable cross-reactive products were obtained on human female DNA, bacteria, and commonly encountered animal species. Additionally, we demonstrated the ability to detect male specific profiles in admixed male and female blood samples at a ratio of 1:1000.

Developmental validation of the Quantifiler(®) HP and Trio Kits for human DNA quantification in forensic samples.

The quantification of human genomic DNA is a necessary first step in the DNA casework sample analysis workflow. DNA quantification determines optimal sample input amounts for subsequent STR (short tandem repeat) genotyping procedures, as well as being a useful screening tool to identify samples most likely to provide probative genotypic evidence. To better mesh with the capabilities of newest-generation STR analysis assays, the Quantifiler(®) HP and Quantifiler(®) Trio DNA Quantification Kits were designed for greater detection sensitivity and more robust performance with samples that contain PCR inhibitors or degraded DNA. The new DNA quantification kits use multiplex TaqMan(®) assay-based fluorescent probe technology to simultaneously quantify up to three human genomic targets, allowing samples to be assessed for total human DNA, male contributor (i.e., Y-chromosome) DNA, as well as a determination of DNA degradation state. The Quantifiler HP and Trio Kits use multiple-copy loci to allow for significantly improved sensitivity compared to earlier-generation kits that employ single-copy target loci. The kits' improved performance provides better predictive ability for results with downstream, newest-generation STR assays, and their shortened time-to-result allows more efficient integration into the forensic casework analysis workflow.

Comparison of near-infrared and laser-induced breakdown spectroscopy for determination of magnesium stearate in pharmaceutical powders and solid dosage forms.

Near-infrared (NIR) spectroscopy has become well established in both the pharmaceutical arena and other areas as a useful technique for rapid quantitative analysis of solid materials. Though laser-induced breakdown spectroscopy (LIBS) has not been widely applied in the pharmaceutical industry, the technique has been used for rapid quantitative analysis of solids in many other applications. One analysis amenable to each technique is the determination of magnesium stearate in solids during the lubrication blending unit operation of pharmaceutical processing. A comparative study of the utility of these two techniques for this application will be presented. Necessary sample preparations and the extent and type of matrix effects will be discussed. Additionally, it will be shown that NIR provides better accuracy and precision than LIBS with the experimental parameters used; however, LIBS showed superior selectivity as it was demonstrated to be more robust to sample matrix perturbations. Examples of blending applications will also be presented.

Developmental validation of the quantifiler real-time PCR kits for the quantification of human nuclear DNA samples.

The Quantifiler Human DNA Quantification Kit and the Quantifiler Y Human Male DNA Quantification Kit were designed for the quantification of human genomic DNA in forensic samples. The kits use a real-time PCR-based process to quantify, respectively, total human DNA or human male DNA only. We report the results of a developmental validation study that we performed with the Quantifiler Kits, following the official SWGDAM guidelines. The Quantifiler Kits were tested for performance criteria such as species specificity, sensitivity, stability, precision and accuracy, and in addition, were tested with forensic case-type samples and mixed (male:female) DNA samples. The Quantifiler Kit methods were highly specific for human DNA, and could detect as little as 32 picograms of DNA using 2 microL of sample per assay. The accuracy and precision of the Quantifiler Kit methods was comparable or superior to that of other quantification methods.

Developmental validation of the AmpFℓSTR® NGM SElect™ PCR Amplification Kit: A next-generation STR multiplex with the SE33 locus.

The AmpFℓSTR(®) NGM SElect™ PCR Amplification Kit is a new 17-plex STR genotyping kit designed for use primarily in forensic casework analysis. The kit was designed to be a counterpart to the AmpFℓSTR(®) NGM™ Kit for laboratories wishing to add the SE33 locus to the new European Standard Set of STR loci. The NGM SElect Kit shares the same primer sets for 16 common loci with the NGM Kit (D10S1248, D3S1358, vWA, D16S539, D2S1338, amelogenin, D8S1179, D21S11, D18S51, D19S433, TH01, FGA, D22S1045, D2S441, D1S1656 and D12S391), with additional primers for the SE33 locus. Developmental validation studies followed the Scientific Working Group on DNA Analysis Methods (SWGDAM) guidelines for STR kit manufacturers and tested several critical areas of kit performance including a sensitivity series, DNA mixtures and inhibited samples. The studies demonstrated that the NGM SElect Kit provides equivalent overall performance to the NGM Kit, but with even greater discriminatory power due to the inclusion of the highly informative SE33 locus.

Identification and secondary structure analysis of a region affecting electrophoretic mobility of the STR locus SE33.

SE33 is one of the most informative markers in forensic use due to its high power of discrimination. During the course of developing the AmpFℓSTR(®) NGM SElect™ PCR Amplification Kit several SE33 primer designs were screened with one primer pair yielding a high frequency of discordant alleles when compared to the AmpFℓSTR(®) SEfiler Plus™ PCR Amplification Kit. This discordance was mostly specific to samples of African descent with an estimated frequency of 5.1% and was a result of a mobility shift of approximately +0.84nt. The sequence analysis of the affected alleles revealed that the only difference from the wild type sequence was a single nucleotide polymorphism (SNP) outside of the SE33 repeat but within the amplicon of this particular set of experimental primers. In total, we identified three different SNPs all within 9nt of each other, each of which could cause the mobility shift individually. Further characterization of this region via site directed mutagenesis and thermostability measurements strongly suggests that this polymorphic region contains a secondary structure that, when disrupted due to the presence of a variant SNP, results in a mobility shift relative to the wild type sequence. To overcome this problem, the SE33 primers used in the final configuration of the NGM SElect™ Kit avoided the amplification of this polymorphic region yielding in turn results highly concordant with the SEfiler Plus™ Kit.

A synthetic model of Hg(II) sequestration.

Tridentate ligand N-(2-pyridylmethyl)-N-(2-(ethylthiolato)amine (L) forms the novel complex [Hg(5)(L)(6)](ClO(4))(4).toluene () with a bicyclo[3.3.3] Hg(5)S(6) core and 4-, 5- and 6-coordinate metal centers; characterization of a solution of by ESI-MS revealed elaborate speciation involving [Hg(n)L(n+1)(ClO(4))(n-2)](+), [Hg(n)L(n)(ClO(4))(n-1)](+) and [Hg(n)L(n-1)(ClO(4))(n)](+) ion families.

A pragmatic approach to biochemical systems theory applied to an alpha-synuclein-based model of Parkinson's disease.

This paper presents a detailed systems model of Parkinson's disease (PD), developed utilizing a pragmatic application of biochemical systems theory (BST) intended to assist experimentalists in the study of system behavior. This approach utilizes relative values as a reasonable initial estimate for BST and provides a theoretical means of applying numerical solutions to qualitative and semi-quantitative understandings of cellular pathways and mechanisms. The approach allows for the simulation of human disease through its ability to organize and integrate existing information about metabolic pathways without having a full quantitative description of those pathways, so that hypotheses about individual processes may be tested in a systems environment. Incorporating this method, the PD model describes alpha-synuclein aggregation as mediated by dopamine metabolism, the ubiquitin-proteasome system, and lysosomal degradation, allowing for the examination of dynamic pathway interactions and the evaluation of possible toxic mechanisms in the aggregation process. Four system perturbations: elevated alpha-synuclein aggregation, impaired dopamine packaging, increased neurotoxins, and alpha-synuclein overexpression, were analyzed for correlation to qualitative PD system hypotheses present in the literature, with the model demonstrating a high level of agreement with these hypotheses. Additionally, various PD treatment methods, including levadopa and monoamine oxidase inhibition (MAOI) therapy, were applied to the disease models to examine their effects on the system. Future additions and refinements to the model may further the understanding of the emergent behaviors of the disease, helping in the identification of system sensitivities and possible therapeutic targets.

In-line monitoring of moisture content in fluid bed dryers using near-IR spectroscopy with consideration of sampling effects on method accuracy.

In-line near-IR moisture monitoring of the dynamic, fluid bed drying environment has been reported in recent years by several research groups; however, analytical figures of merit with regard to prediction accuracy are discussed in only a subset of this work, and issues with sampling and sample presentation are scarcely addressed at all. In this study, experiments were performed at 65-, 300-, and 600-L drying scales using several different sampling configurations in an effort to better understand and improve in-line near-IR method accuracy. Findings from this work demonstrate that process heterogeneity plays a major role in determination of apparent prediction accuracy. This aspect is general to all in-line measurements and plays an especially important role in solids and slurry systems that are prone to heterogeneity. In addition to experimental results, simulations based on these findings and sampling theory demonstrate an interesting paradox: depending on the sampling configuration employed, the method with the smallest apparent error is not necessarily optimal for process monitoring and control. Furthermore, sampling configuration influences the number of samples necessary to define an adequate calibration set. Finally, process understanding that was gained as a result of temporally rich, in-line measurements will be presented.

Spectroscopic approach for on-line monitoring of particle size during the processing of pharmaceutical nanoparticles.

A novel application of near-infrared (near-IR) spectroscopy for the on-line determination of nanoparticle size of a drug compound in a high solids dispersion is described. The on-line spectroscopic technique provides real-time data for process monitoring and control and overcomes the limitations that are encountered using laboratory-based instrumentation for nanoparticle size determination. Near-IR spectroscopy is capable of providing an accuracy of 2.4 nm near the endpoint of particle production, where the volume-weighted D90 particle size is determined to be 200-220 nm. The accuracy is adequate for endpoint control, which minimizes excess processing and provides control over the particle size throughout nanoparticle production.