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We provide an update on diagnostic methods for the detection of urogenital schistosomiasis (UGS) in men and highlight that satisfactory urine-antigen diagnostics for UGS lag much behind that for intestinal schistosomiasis, where application of a urine-based point-of-care strip assay, the circulating cathodic antigen (CCA) test, is now advocated. Making specific reference to male genital schistosomiasis (MGS), we place greater emphasis on parasitological detection methods and clinical assessment of internal genitalia with ultrasonography. Unlike the advances made in defining a clinical standard protocol for female genital schistosomiasis, MGS remains inadequately defined. Whilst urine filtration with microscopic examination for ova of Schistosoma haematobium is a convenient but error-prone proxy of MGS, we describe a novel low-cost sampling and direct visualization method for the enumeration of ova in semen. Using exemplar clinical cases of MGS from our longitudinal cohort study among fishermen along the shoreline of Lake Malawi, the portfolio of diagnostic needs is appraised including: the use of symptomatology questionnaires, urine analysis (egg count and CCA measurement), semen analysis (egg count, circulating anodic antigen measurement and real-time polymerase chain reaction analysis) alongside clinical assessment with portable ultrasonography.
A collection of 65 formulated tablets and capsules were analyzed for phase composition by full pattern matching powder diffraction methods. The collection contained 32 of the top 200 prescription drugs sold in 2016 as well as many high-volume prescriptions and over the counter drugs from prior years. The study was used to evaluate new methods of analysis as well as the efficacy of programs designed to collect references on high volume excipients and pharmaceuticals for inclusion in the Powder Diffraction File™. The use of full pattern matching methods as well as reference pattern additions of many common excipients enabled major phase excipient identification in all formulations. This included identification of crystalline, nanocrystalline, and amorphous ingredients because full pattern matching involved the use of characteristic coherent and incoherent scatter. Oftentimes identification of the major excipients significantly aided the clean identification of the active pharmaceutical ingredients (APIs) and their polymorphic form, even at low concentrations (1–10 wt. %). Overall 93% of the APIs were identified, most through a PDF® material reference, but also through patent cross-referencing and similarity analysis comparisons.
Advances in instrumentation, software applications, and database content have all contributed to improvements in pharmaceutical analyses by powder diffraction methods in the 21st century. When compared to the globally harmonized United States Pharmacopeia General Chapter <941>, “Characterization of Crystalline and Partially Crystalline Solids by X-ray Powder Diffraction”, many historic problems in pharmaceutical analysis have been addressed by combinations of improved methods and instrumentation. Major changes in the last 20 years include (i) a dramatic lowering in detection capability and detection limits, (ii) enhanced capabilities for dynamic measurements such as in situ analyses under a variety of conditions, and (iii) the ability to identify and characterize nanomaterials, non-crystalline, and amorphous materials by both coherent and incoherent scattering profiles.
Due to the difficulty of analyzing materials at high temperatures and in reactive atmospheres, solid-state catalysts have often been developed with little knowledge of the true chemical behavior of the catalyst, except on a bulk scale. In the field of solid-state catalysis research, a great deal of time and effort is presently being spent to better characterize the chemical and physical properties which determine a particular catalyst‘s efficiency, lifetime, and selectivity. Recently, we have undertaken a study of model copper catalysts at The Dow Chemical Company in an effort to better understand the chemical and physical properties which determine the efficiency, regenerability, and lifetime of this type of solid state catalyst.
The analysis of multi-phase pharmaceuticals, particularly when similar structures are involved (i.e. polymorphs, salts or hydrates), can often be a difficult task. Historically, x-ray powder diffraction (XRD) and differential scanning calorimetry (DSC) have been utilized to study pharmaceutical samples. Relative to other materials, diffraction data for pharmaceuticals are often complex due to the large number of diffraction maxima caused by the size of the molecule and/or the molecular symmetry. Multi-phase mixtures tend to have a large number of overlapping peaks which can hinder the difftactionist's ability to identify phases and interpret the data. When similar structures are analyzed calorimetrically, their thermal events may severely overlap (as will be shown), preventing accurate interpretation of the data. In addition there are several types of thermal events which may not be related to structural transitions. A common one in pharmaceuticals is the loss of solvent or absorbed (versus molecular) water.
Over the past 25 years, numerous studies utilizing both X-ray diffraction (XRE) and differential scanning calorimetry (DSC) have been reported In the literature. Generally, conventional high-temperature X-ray data identifies solid-state transitions, then attempts to correlate them with thermal events observed by the calorimeter. Since changes occur in the sample during studies such as these, separate portions of the sample must be used for XRD and DSC experiments. When comparing results of the two experiments, questions arise concerning sample homogeniety as well as temperature and environmental differences. In fact, no conventional high-temperature X-ray diffraction instrument can give the precise control over temperature and heating rate available with a DSC, The problems of sample inhomogeneltles and Instrumental differences could be avoided if X-ray diffraction and DSC could be performed simultaneously on one sample.
The following study is an evaluation of several different types of instrumentation available for use in powder x-ray diffraction work. The particular units used are those at the Dow Chemical Company x-ray diffraction lab. The variety of instrumentation allows analyses from routine phase identification to more specialized work such as low-angle x-ray diffraction of polymers and high-resolution analysis for cell parameter refinements.
The purpose of this work is to compare the relative capabilities of these different instruments under typical day-to-day operating conditions. While not a comprehensive study, the conclusions drawn should be applicable to powder x-ray diffraction in general.
Bendamustine hydrochloride monohydrate (marketed as Treanda®) is a nitrogen mustard purine analog alkylator used in the treatment of chronic lymphocytic leukemia (CLL) and non-Hodgkin lymphomas. Commercial bendamustine hydrochloride monohydrate crystallizes in the monoclinic space group P21/c (14), with a = 4.71348(4) Å, b = 47.5325(3) Å, c = 8.97458 (5) Å, β = 96.6515(8)°, V = 1997.161(23) Å3, and Z = 4. A reduced cell search in the Cambridge Structural Database yielded a previously reported crystal structure (Allen, 2002), which did not include hydrogens (Reck, 2006). In this work, the sample was ordered from Santa Cruz Biotechnology, and analyzed as received. The room-temperature crystal structure was refined using synchrotron (λ = 0.413896 Å) powder diffraction data, density functional theory (DFT), and Rietveld refinement techniques. Hydrogen positions were included as part of the structure, and recalculated during the refinement. The diffraction data were collected on beamline BM-11 at the Advanced Photon Source, Argonne National Laboratory. Figure 1 shows the powder X-ray diffraction pattern of the compound. The pattern is included in the Powder Diffraction File as entry 00-064-1508.
Whole-rock, minor element, rare earth, and electron microprobe data are presented for basaltic lavas from the western Kangerdlugssuaq area of East Greenland. Samples were obtained from Professor W. A. Deer's 1936 collection at Triangular Nunataks and Gardiner Plateau, and additional material obtained by sampling moraines on the surface of Kangerdlugssuaq Glacier. Both undersaturated and tholeiitic lavas are present at the Triangular Nunatak locality but the glacier suite is dominantly tholeiitic. The tholeiitic suite is less evolved than tholeiites from the Scoresby Sund area. Undersaturated lavas show enrichment in light rare earth elements and tholeiitic lavas show fiat chondrite-normalized patterns. Tholeiites from the Gardiner Plateau show no Eu anomaly but others show a slight negative Eu anomaly. Chemical data and considerations of regional geology are consistent with Cox's (1980) model of flood basalt vulcanism.
Black, opaque grains of a spinel whose composition is (Mg2TiO4) 85.8, (MgFe2O4) 0.4 (FeFe2O4) 13.8 (mole %) coexist with a MgAl2O4 spinel and geikielite in a periclase-forsterite marble that has been thermally metamorphosed against an alkalic ultramafic intrusion of Caledonian age in the Kangerdlugssuaq region of East Greenland. The spinel appears to be the closest recorded approach to the end-member Mg2TiO4 among natural rocks, and to be part of a solid-solution series extending across the join Mg2TiO4-MgFe2O4-FeFe2O4, the existence of which has not previously been reported. The composition of the series appears to be controlled by the fO2 that prevails during metamorphism.
The ICDD has developed a microanalysis tool to help scientists identify minerals from their elemental analyses, most typically micro-XRF or a microprobe analysis. Many minerals have characteristic elemental profiles that can often distinguish the mineral from others by their composition differences. In Release 2016 ICDD® PDF-4 databases 20 670 unique compositions have been identified out of 45 497 mineral and mineral-related entries. The application utilizes several common features of PDF® databases to enhance correct identification, most notably those formulas are expressed in weight and atomic percent, data sets are classified by mineral nomenclature and structural classifications, and most minerals have associated atomic and molecular structures. These crystal structures are very useful in determining compositional variants and solid solutions. The ICDD has developed algorithms that are analogous to the search/match processes used for powder diffraction identification. Data can be input as either the element or common oxide. To test the algorithm and graphics interfaces we compared results from the microanalysis module to published data from the Smithsonian Microbeam reference mineral collection. The software correctly identified 24/28 minerals by the highest merit score in the algorithm. In two cases, an isoelemental mineral was identified and in two other cases, the specimens had more elements than the reference standards hindering positive phase identification.
Why do issues “fade” from the problem stream? This is an important but underresearched question, which this article examines by looking at the dynamic interaction between frames and frame sponsors. We develop a novel methodological approach that combines algorithmic coding (topic modelling) with hand-coding to track changes in the presence of frames and frame sponsors during periods of intense problematisation (“problem windows”) both within continuous contexts and diachronically across different contexts. We apply this approach empirically in a corpus of newspaper articles that pertain to the coal seam gas controversy in Australia – a divisive policy issue where frame conflicts are common. We find that elite actors have a particularly decisive impact on the problem stream in terms of both the evolution and duration of debate. Further, problem windows close in response to three different mechanisms: elite frame convergence; public statements (by government and industry); and elections.
Roman bronze coins from the 3rd and 4th century AD exhibit a wide variety of chemistries on their surfaces. This variation has been attributed to the variable methods used to produce the coins, a large number of mints producing bronze currency, and the periods of currency devaluation within the Roman Empire. Besides the base bronze metallurgy (Cu,Sn), Ag, Pb, and Zn were frequently used as coinage metals. Silver coatings were often applied to increase the apparent value of the coins. Over the centuries these surfaces corroded producing a range of patinas. Non-destructive X-ray diffraction and X-ray fluorescence methods were used to evaluate ancient bronze coins. These methods are limited by their half depth of penetration into the coins, so the focus was on the chemistry of the patina's and how they related to the current appearance. Several 3rd-century bronze coins exhibited a very dark patina that was often composed of CuCl, Cu2O (cuprite) and several forms of copper hydroxyl chloride, resulting from surface deterioration caused by corrosion and is often referred to as bronze disease. Coins of the latter 3rd century and 4th century often exhibit patinas that are corrosion products of lead, silver, and tin, as lead and tin preferentially oxidize relative to the bronze alloys.
There are many rationing models used commercially for evaluating diets fed to dairy cows. A new model – BioParaMilk – uses a unique protein degradation model to determine microbial protein synthesis, based upon the in vitro gas production technique (IVGPT). Optigen®, a slow release, blended, non-protein nitrogen source, can partially replace soyabean meal (SBM) in a dairy diet. The partial replacement of soyabean meal and rapeseed meal with Optigen® has been shown to increase fibre digestion and may improve volatile fatty acid (VFA) and microbial nitrogen (N) flow in the rumen (Sinclair et al., 2008). The purpose of this study was to evaluate the protein degradation curve from Optigen® compared to SBM for use in this new model, using IVGPT.
OBJECTIVES/SPECIFIC AIMS: As part of a larger effort to create a longitudinal record of care for patients with chronic kidney disease (CKD) in Delaware, we assessed transitions of care from pediatric to adult care. This study examined the length of time between last pediatric contact and first contact in the adult system in order to determine characteristics associated with delayed transition to adult care. METHODS/STUDY POPULATION: Patients who receive pediatric care at the Nemours/Alfred I. duPont Hospital for Children (Nemours) are transitioned to adult care between the ages of 18 and 21. Our study population consists of all patients seen in the Nephrology unit at Nemours for CKD, hypertension (HTN), or diabetes who turned 21 years old between 2007 and 2013. Records of office visits from Nemours, Christiana Care Health System (CCHS), and Nephrology Associates, P.A. (NAPA) were transformed into the OMOP common data model and merged. Patients who had at least 1 record in the Nemours EHR of pediatric care before age 21 and had at least 1 record in the CCHS or NAPA adult EHRs were considered transitioned. To identify characteristics associated with delayed transition to adult care, we compared gender, race, ethnicity, age, comorbidities, and level of kidney function at the last pediatric visit between patients whose transition gap was less than 1 year and patients whose gap was 1 year or more. Kidney function was estimated by calculating glomerular filtration rate (GFR). Nemours estimates GFR in children using the revised Schwartz equation, which is based on serum creatinine and height. To calculate adult GFR, we used the CKD-Epi equation, which is based on serum creatinine, age, sex, and race and is widely used to derive adult GFR. As kidney function declines, GFR decreases. We used Fisher exact test to compare categorical variables and t-test to compare age and GFR. RESULTS/ANTICIPATED RESULTS: We found only 109 (25%) patients who had records in our adult offices out of the 440 Nemours patients in our data set. Of the 109 transitioned patients, 54 had office visits at CCHS, 37 at NAPA, and 18 at both locations. Examining the office visits of the 109 transitioned patients, 34 (31%) had an overlap in visits defined as an office visit at CCHS or NAPA before the last office visit at Nemours, and 75 (69%) did not have an overlap. The median gap between last pediatric and first adult office visit for the 75 patients without an overlap was 615 days (range 8–3495 d). Only 6 (6%) of the 109 transitioned patients had overlapping GFR measurements from pediatric to adult care, and all of the adult GFR calculations (CKD-Epi) were greater than the pediatric GFR calculations (Schwartz). The difference between child and adult GFR ranged from 8.2 to 87.1 mL/minute per 1.72 m2. DISCUSSION/SIGNIFICANCE OF IMPACT: During the transition from pediatric care to adult care, many young adults with CKD experience declines in health outcomes and comorbidities such as diabetes and HTN complicate self-management. Lack of overlap between pediatric and adult care office visits indicates a delay in executing this transition. In our population of 109 transitioned patients, 69% did not have an overlap in care, and 50% of those without overlap had a gap of more than 615 days (1 y, 8 mo). Our analysis suggests that young adults who are younger at last pediatric office visit are more likely to delay transitioning to adult care. Transitioning from the nurturing environment of pediatric care to adult care is a complex process and could be challenging for young adults with CKD. Transition clinics may be necessary to improve the coordination of care and help these young adults keep their physician appointments.
As we celebrate the 75th anniversary of the Powder Diffraction File, the PDF® is still a method for chemical and material analyses. The database and embedded software are designed to solve a range of solid-state material analysis problems that includes phase identification, quantitative analysis, crystallinity, and crystallite size measurements. A versatile platform allows users to interpret X-ray, electron, neutron, or synchrotron diffraction patterns for their analyses. Over several decades as diffraction hardware and software continued to improve, the International Centre for Diffraction Data continues to improve the methods and the PDF database, offering unprecedented analysis capabilities to the modern user.
The PDF-4+ 2016 contains 271 449 entries with atomic coordinates that can be used to calculate neutron time-of-flight (TOF) powder diffraction patterns. These diffraction patterns can all be calculated on-the-fly. Three TOF results can be realized: the live calculation of on-the fly diffraction patterns, the population of static PDF® entries, and data for search/match tables for phase identification. In connection with search/match, we have extended the development of the I/Ic formalism to include both constant wavelength (CW) and TOF neutron diffraction data. It is shown that the wavelength dependence of X-ray and CW neutron data must be factored into the behavior of I/Ic, whereas this dependence is directly incorporated into TOF data.