Clinical utility of skin cancer and melanoma risk scores for population screening: TRoPICS study.

BACKGROUND: Screening for skin cancer can be cost-effective if focused on high-risk groups. Risk prediction tools have been developed for keratinocyte cancers and melanoma to optimize advice and management. However, few have been validated in a clinical setting over the past few years. OBJECTIVES: To assess the clinical utility of risk assessment tools to identify individuals with prevalent skin cancers in a volunteer-based screening clinic. METHODS: Participants were adults presenting for a skin check at a volunteer-based skin cancer screening facility. We used previously published tools, based on questionnaire responses, to predict melanoma and keratinocyte cancers [KCs; basal cell carcinoma (BCC) and squamous cell carcinoma (SCC)] and classified each participant into one of five risk categories. Participants subsequently underwent a full skin examination by a dermatologist. All suspicious lesions were biopsied, and all cancers were histopathologically confirmed. RESULTS: Of 789 people who presented to the clinic, 507 (64%) consented to the study. Twenty-two BCCs, 19 SCCs and eight melanomas were diagnosed. The proportion of keratinocyte cancers diagnosed increased according to risk category from <1% in the lowest to 24% in the highest risk category (P < 0.001). Subtype analysis revealed similar proportionate increases in BCC or SCC prevalence according to risk category. However, a similar proportion of melanoma cases were detected in the low-risk and high-risk groups. CONCLUSION: The risk prediction model for keratinocyte cancers can reliably identify individuals with a significant skin cancer burden prior to a skin examination in the community setting. The prediction tool for melanoma needs to be tested in a larger sample exposed to a wider range of environmental risk factors.

A prospective study evaluating the integration of a multifaceted evidence-based medicine curriculum into early years in an undergraduate medical school.

BACKGROUND: The importance of ensuring medical students are equipped with the skills to be able to practice evidence-based medicine (EBM) has been increasingly recognized in recent years. However, there is limited information on an effective EBM curriculum for undergraduate medical schools. This study aims to test the feasibility of integrating a multifaceted EBM curriculum in the early years of an undergraduate medical school. This was subsequently evaluated using the validated Fresno test and students' self-reported knowledge and attitudes as they progressed through the curriculum. METHODS: EBM was integrated horizontally and vertically into the curriculum into the first 2 years of undergraduate medical school. First year medical students were recruited to participate in the study. The 212-point Fresno test was administered along with a locally developed questionnaire at baseline before EBM teaching in year one and at the end of EBM teaching in year two. RESULTS: Thirty-one students participated at baseline and 55 students participated at the end of second year EBM teaching. For the 18 students who completed the Fresno at both time points, the average score increased by 38.7 marks (p < 0.001) after EBM teaching. Students felt confident in formulating clinical questions and in critically appraising journal articles after EBM teaching. EBM was perceived to be important to their future practice as a doctor and for improving patient outcomes at both time points. CONCLUSIONS: It has been feasible to integrate a multifaceted, EBM curriculum from the first year of an undergraduate medical program. Early evaluation of the curriculum using the Fresno test has shown a significant increase in students' EBM knowledge. The curriculum also demonstrated an increase in students' perceptions of the clinical relevance of EBM in their developing practice.

Quantifying TB transmission: a systematic review of reproduction number and serial interval estimates for tuberculosis.

Tuberculosis (TB) is the leading global infectious cause of death. Understanding TB transmission is critical to creating policies and monitoring the disease with the end goal of TB elimination. To our knowledge, there has been no systematic review of key transmission parameters for TB. We carried out a systematic review of the published literature to identify studies estimating either of the two key TB transmission parameters: the serial interval (SI) and the reproductive number. We identified five publications that estimated the SI and 56 publications that estimated the reproductive number. The SI estimates from four studies were: 0.57, 1.42, 1.44 and 1.65 years; the fifth paper presented age-specific estimates ranging from 20 to 30 years (for infants <1 year old) to <5 years (for adults). The reproductive number estimates ranged from 0.24 in the Netherlands (during 1933-2007) to 4.3 in China in 2012. We found a limited number of publications and many high TB burden settings were not represented. Certain features of TB dynamics, such as slow transmission, complicated parameter estimation, require novel methods. Additional efforts to estimate these parameters for TB are needed so that we can monitor and evaluate interventions designed to achieve TB elimination.

Digestive gland inclusion bodies in queen conch (Lobatus gigas) are non-parasitic.

Unusual inclusion bodies occur within the epithelial cells of the digestive gland of queen conch, Lobatus gigas, and have previously been described as apicomplexan parasites. The aim of this study was to investigate the parasitic features of these inclusion bodies in queen conch. L. gigas from St. Kitts (Caribbean Sea) consistently (100% of n = 61) showed large numbers of ovoid to tri-bulbous dark brown inclusion bodies (15 × 30 µm) within vacuolar cells. Histochemical stains demonstrated iron, melanin, and glycoprotein and/or mucopolysaccharide within the inclusion bodies. Microscopic features indicative of a host response to injury were lacking in every case, as were consistent morphological forms to indicate distinct parasitic stages. Transmission electron microscopy failed to reveal cellular organelles of parasitic organisms and DNA extractions of purified inclusion bodies did not yield sufficient concentrations for successful PCR amplification. Scanning electron microscopy with energy dispersive X-ray analysis revealed a number of elements, particularly iron, within the inclusion bodies. We conclude that the inclusion bodies are not an infectious agent, and hypothesize that they represent a storage form for iron, and potentially other elements, within a protein matrix. Similar structures have been described in the digestive glands of other invertebrates, including prosobranchs.

Predictive thermodynamics for ionic solids and liquids.

The application of thermodynamics is simple, even if the theory may appear intimidating. We describe tools, developed over recent years, which make it easy to estimate often elusive thermodynamic parameter values, generally (but not exclusively) for ionic materials, both solid and liquid, as well as for their solid hydrates and solvates. The tools are termed volume-based thermodynamics (VBT) and thermodynamic difference rules (TDR), supplemented by the simple salt approximation (SSA) and single-ion values for volume, Vm, heat capacity, , entropy, , formation enthalpy, ΔfH°, and Gibbs formation energy, ΔfG°. These tools can be applied to provide values of thermodynamic and thermomechanical properties such as standard enthalpy of formation, ΔfH°, standard entropy, , heat capacity, Cp, Gibbs function of formation, ΔfG°, lattice potential energy, UPOT, isothermal expansion coefficient, α, and isothermal compressibility, ß, and used to suggest the thermodynamic feasibility of reactions among condensed ionic phases. Because many of these methods yield results largely independent of crystal structure, they have been successfully extended to the important and developing class of ionic liquids as well as to new and hypothesised materials. Finally, these predictive methods are illustrated by application to K2SnCl6, for which known experimental results are available for comparison. A selection of applications of VBT and TDR is presented which have enabled input, usually in the form of thermodynamics, to be brought to bear on a range of topical problems. Perhaps the most significant advantage of VBT and TDR methods is their inherent simplicity in that they do not require a high level of computational expertise nor expensive high-performance computation tools - a spreadsheet will usually suffice - yet the techniques are extremely powerful and accessible to non-experts. The connection between formula unit volume, Vm, and standard thermodynamic parameters represents a major advance exploited by these techniques.

Structures, vibrational frequencies, and stabilities of halogen cluster anions and cations, X(n)(+/-), n = 3, 4, and 5.

The structures, vibrational frequencies, and thermodynamic stabilities of the homonuclear polyhalogen ions, X3(+), X3(-), X4(+), X4(-), X5(+), and X5(-) (X = Cl, Br, I), have been calculated at the CCSD(T) level. The energetics were calculated using the Feller-Peterson-Dixon approach for the prediction of reliable enthalpies of formation. The calculations allow the following predictions where stabilities are defined in terms of thermodynamic quantities. (1) The X3(+) cations are stable toward loss of X2; (2) the X3(-) anions are marginally stable toward loss of X2 with Cl3(-) being the least stable; (3) the X4(+) cations and X4(-) anions are only weakly bound dimers of X2(+1/2) and X2(-1/2) units, respectively, but the cations are marginally stable toward decomposition to X3(+) and X, with I4(+) having the lowest dissociation energy, whereas the X4(-) anions decompose spontaneously to X3(-) and X; (4) the X5(+) cations are only marginally stable at low temperatures toward loss of X2, with Cl5(+) being the least stable; and (5) the X5(-) anions are also only stable at low temperatures toward loss of X2, with Cl5(-) being the least stable.

Coeliac disease is more common in children with high socio-economic status.

AIM: There are a number of genetic and environmental factors that are associated with an increased risk of developing coeliac disease. Our aim was to determine whether socio-economic deprivation increases or reduces the development of the disease. METHODS: A cross-sectional study identified all children <16 years old diagnosed with coeliac disease in the same tertiary paediatric centre between January 1995 and December 2011. Data, including age at diagnosis and postcode, were collected and linked with the quintile rank of the Welsh Index of Multiple Deprivation score 2008, a measure of socio-economic status. RESULTS: We included 232 patients and identified a graded association between the prevalence of coeliac disease and socio-economic deprivation, which showed a higher rate in children living in more affluent areas. The largest difference was between the lowest deprivation level (rate/1000 = 1.16) and the highest deprivation level (rate/1000 = 0.49). CONCLUSION: In our population, coeliac disease was more common in children in the higher socio-economic groupings. The reasons for this are not clear, but perhaps both the 'hygiene hypothesis' and the health seeking behaviours of parents with high socio-economic status are possible factors in the more frequent diagnosis of coeliac disease in this group.

Geographical heterogeneity of multidrug-resistant tuberculosis in Georgia, January 2009 to June 2011.

In 2011, Georgia, in the Caucasus, reported that 11% of new and 32% of previously treated tuberculosis (TB) cases nationally had multidrug-resistant TB (MDR-TB). To help understand the mechanisms driving these high risks of drug-resistance and plan for targeted interventions, we identified geographical variability in the MDR-TB burden in Georgia and patient-level MDR-TB risk factors. We used routinely collected surveillance data on notified TB cases to estimate the MDR-TB incidence/100,000 people and the percentage of TB cases with MDR-TB for each of 65 districts and regression modelling to identify patient-level MDR-TB risk factors. 1,795 MDR-TB cases were reported (January 2009­June 2011); the nationwide notified MDR-TB incidence was 16.2/100,000 but far higher (837/100,000) in the penitentiary system. We found substantial geographical heterogeneity between districts in the average annual MDR-TB incidence/100,000 (range: 0.0­5.0 among new and 0.0­18.9 among previously treated TB cases) and the percentage of TB cases with MDR-TB (range: 0.0%­33.3% among new and 0.0%­75.0% among previously treated TB cases). Among treatment-naïve individuals, those in cities had greater MDR-TB risk than those in rural areas (increased odds: 43%; 95% confidence interval: 20%­72%). These results suggest that interventions for interrupting MDR-TB transmission are urgently needed in prisons and urban areas.

Outcomes for people with TB by disease severity at presentation.

There is substantial heterogeneity in disease presentation for individuals with TB disease, which may correlate with disease outcomes. We estimated disease outcomes by disease severity at presentation among individuals with TB during the pre-chemotherapy era.We extracted data on people with TB enrolled between 1917 and 1948 in the USA, stratified by three disease severity categories at presentation using the U.S. National Tuberculosis Association diagnostic criteria. These criteria were based largely on radiographic findings ("minimal", "moderately advanced", and "far advanced"). We used Bayesian parametric survival analysis to model the survival distribution overall, and by disease severity and Bayesian logistic regression to estimate the severity-level specific natural recovery odds within 3 years.People with minimal TB at presentation had a 2% (95% CrI 0-11%) probability of TB death within 5 years vs. 40% (95% CrI 15-68) for those with far advanced disease. Individuals with minimal disease had 13.62 times the odds (95% CrI 9.87-19.10) of natural recovery within 3 years vs. those with far advanced disease.Mortality and natural recovery vary by disease severity at presentation. This supports continued work to evaluate individualized (e.g., shortened or longer) regimens based on disease severity at presentation, identified using radiography..

Synthesis of (TDAE)(O2SSO2)(s) and discovery of (TDAE)(O2SSSSO2)(s) containing the first polythionite, [O2SSSSO2]2-.

Gaseous SO2 reacts with tetrakis(dimethylamino)ethylene (TDAE) in acetonitrile in a 2:1 stoichiometric ratio to give analytically pure insoluble purple (TDAE)(O2SSO2) (1) in about 80% yield. Crystals of (TDAE)(O2SSSSO2) (2) were obtained from orange solution over the purple solid. The Raman spectrum of [TDAE](2+) was established using (TDAE)(A) salts [A = 2Br(-), 2Br(-)·2H2O (X-ray), 2[Br3](-) (X-ray)]. Vibrational spectroscopy showed that [O2SSO2](2-) in 1 has C2h geometry. The X-ray structure of 2 showed that it contained [O2SSSSO2](2-), the first example of a new class of sulfur oxyanions, the polythionites. The geometry of [O2SSSSO2](2-) consists of S2 with an S-S bond length of 2.003(1) Å connected to two terminal SO2 moieties by much longer S-S bonds of 2.337(1) Å. Calculations (B3PW91/6-311+G(3df)) show that the structural units in [O2SSSSO2](2-) are joined by the interaction of electrons in two mutually perpendicular π* SOMOs of the triplet-state diradical S2 with unpaired electrons in the π*-antibonding orbitals of the two terminal [SO2](•-) and polarized to delocalize the negative charge equally onto the three fragments. Thermodynamic estimates show 2 to be stable with respect to loss of sulfur and formation of 1, in contrast to [O2SSSSO2](2-) salts of small cations that are unstable toward the related dissociation. Reaction of TDAE with an excess of liquid SO2 led to (TDAE)(O3SOSO3)·SO2 (preliminary X-ray, Raman), (TDAE)(O3SSSSO3)·2SO2 (preliminary X-ray, Raman), and (TDAE)(O3SSO2) (Raman).

Survival of people with untreated TB: effects of time, geography and setting.

BACKGROUND: An estimated 40% of people who developed TB in 2021 were not diagnosed or treated. Pre-chemotherapy era data are a rich resource on survival of people with untreated TB. We aimed to identify heterogeneities in these data to inform their more precise use.METHODS: We extracted survival data from pre-chemotherapy era papers reporting TB-specific mortality and/or natural recovery data. We used Bayesian parametric survival analysis to model the survival distribution, stratifying by geography (North America vs. Europe), time (pre-1930 vs. post-1930), and setting (sanitoria vs. non-sanitoria).RESULTS: We found 12 studies with TB-specific mortality data. Ten-year survival was 69% in North America (95% CI 54-81) and 36% in Europe (95% CI 10-71). Only 38% (95% CI 18-63) of non-sanitorium individuals survived to 10 years compared to 69% (95% CI 41-87) of sanitoria/hospitalized patients. There were no significant differences between people diagnosed pre-1930 and post-1930 (5-year survival pre-1930: 65%, 95% CI 44-88 vs. post-1930: 72%, 95% CI 41-94).CONCLUSIONS: Mortality and natural recovery risks vary substantially by location and setting. These heterogeneities need to be considered when using pre-chemotherapy data to make inferences about expected survival of people with undiagnosed TB.

Amorphous/crystalline (A/C) thermodynamic "rules of thumb": estimating standard thermodynamic data for amorphous materials using standard data for their crystalline counterparts.

Standard thermochemical data (in the form of Δ(f)H° and Δ(f)G°) are available for crystalline (c) materials but rarely for their corresponding amorphous (a) counterparts. This paper establishes correlations between the sets of data for the two material forms (where known), which can then be used as a guideline for estimation of missing data. Accordingly, Δ(f)H°(a)/kJ mol(-1) ≈ 0.993Δ(f)H°(c)/kJ mol(-1) + 12.52 (R(2) = 0.9999; n = 50) and Δ(f)G°/kJ mol(-1) ≈ 0.988Δ(f)H°(c)/kJ mol(-1) + 0.70 (R(2) = 0.9999; n = 10). Much more tentatively, we propose that S°(298)(c)/J K(-1) mol(-1) ≈ 1.084S°(298)(c)/J K(-1) mol(-1) + 6.54 (R(2) = 0.9873; n = 11). An amorphous hydrate enthalpic version of the Difference Rule is also proposed (and tested) in the form [Δ(f)H°(M(p)X(q)·nH(2)O,a) - Δ(f)H°(M(p)X(q),a)]/kJ mol(-1) ≈ Θ(Hf)n ≈ -302.0n, where M(p)X(q)·nH(2)O represents an amorphous hydrate and M(p)X(q) the corresponding amorphous anhydrous parent salt.

Single-ion heat capacities, C(p)(298)ion, of solids: with a novel route to heat-capacity estimation of complex anions.

Single-ion heat capacities, C(p)(298)(ion), are additive values for the estimation of room-temperature (298 K) heat capacities of ionic solids. They may be used for inferring the heat capacities of ionic solids for which values are unavailable and for checking reported values, thus complementing our independent method of estimation from formula unit volumes (termed volume-based thermodynamics, VBT). Analysis of the reported heat-capacity data presented here provides a new self-consistent set of heat capacities for both cations and anions that is compatible (and thus may be combined) with an extensive set developed by Spencer. The addition of a large range of silicate species permits the estimation of the heat capacities of many silicate minerals. The single-ion heat capacities of individual silicate anions are observed to be strictly proportional to the total number of atoms (Si plus O), n, contained within the silicate anion complex itself (e.g., for the anion Si(2)O(7)(2-), n = 9, for SiO(4)(2-), n = 5), C(p)(silicate anion)/J K(-1) mol(-1) = 13.8n, in a new rule that is an extension of the Neumann-Kopp relationship. The same linear relationship applies to other homologous anion series (for example, oxygenated heavy-metal anion complexes such as niobates, bismuthates, and tantalates), although with a different proportionality constant. A similar proportionality, C(p)(complex anion)/J K(-1) mol(-1) ≈ 17.5n, which may be regarded as a convenient "rule of thumb", also applies, although less strictly, to complex anions in general. The proportionality constants reflect the rigidity of the complex anion, being always less than the Dulong-Petit value of 25 J K(-1) mol(-1). An emergent feature of our VBT and single-ion approaches to an estimation of the thermodynamic properties is the identification of anomalies in measured values, as is illustrated in this paper.

Risk of epithelial ovarian cancer in asymptomatic women with ultrasound-detected ovarian masses: a prospective cohort study within the UK collaborative trial of ovarian cancer screening (UKCTOCS).

OBJECTIVE: To estimate the risk of primary epithelial ovarian cancer (EOC) and slow growing borderline or Type I and aggressive Type II EOC in postmenopausal women with adnexal abnormalities on ultrasound. METHODS: This was a prospective cohort study in the ultrasound group of the UK Collaborative Trial of Ovarian Cancer Screening of postmenopausal women with ultrasound-detected abnormal adnexal (unilocular, multilocular, unilocular solid and multilocular solid, solid) morphology on their first scan. Women were followed up through the national cancer registries and by postal questionnaires. Absolute risks of EOC and borderline, Type I and Type II EOC within 3 years of initial scan were calculated. RESULTS: Of 48 053 women who underwent ultrasound examination and had complete scan data, 4367 (9.1% (95% CI, 8.8-9.3%)) had abnormal adnexal morphology. Median follow-up was 7.09 (25(th) -75(th) centiles, 6.03-7.92) years. Forty-seven (32 borderline or Type I, 15 Type II) were diagnosed with EOC. The overall absolute risk of EOC associated with abnormal adnexal morphology was 1.08% (95% CI, 0.79-1.43%); for borderline and Type I it was 0.73% (95% CI, 0.5-1.03%); and for Type II it was 0.34% (95% CI, 0.33-0.79%). In the subgroup (n = 741) with solid elements (unilocular solid, multilocular solid and solid) overall absolute risk was 4.45% (95% CI, 3.08-6.20%), for borderline and Type I it was 3.1% (95% CI, 1.9-4.6%) and for Type II it was 1.3% (95% CI, 0.6-2.4%). 11 982 women had both ovaries visualized and normal annual scans throughout the 3-year follow-up period. In this group, no borderline or Type I and eight Type II cancers were diagnosed. CONCLUSION: Asymptomatic postmenopausal women with ultrasound-detected adnexal abnormalities with solid elements have a 1 in 22 risk for EOC. Despite the higher prevalence of Type II EOC, the risk of borderline or Type I cancer in women with ultrasound abnormalities seems to be higher than does the risk of Type II cancer. This has important immediate implications for patients with incidental adnexal findings as well as for any future ultrasound-based screening.

Unique thermodynamic relationships for ΔfHo and ΔfGo for crystalline inorganic salts. I. Predicting the possible existence and synthesis of Na2SO2 and Na2SeO2.

The concept that equates oxidation and pressure has been successfully utilized in explaining the structural changes observed in the M(2)S subnets of M(2)SO(x) (x = 3, 4) compounds (M = Na, K) when compared with the structures (room- and high-pressure phases) of their parent M(2)S `alloy' [Martínez-Cruz et al. (1994), J. Solid State Chem. 110, 397-398; Vegas (2000), Crystallogr. Rev. 7, 189-286; Vegas et al. (2002), Solid State Sci. 4, 1077-1081]. These structural changes suggest that if M(2)SO(2) would exist, its cation array might well have an anti-CaF(2) structure. On the other hand, in an analysis of the existing thermodynamic data for M(2)S, M(2)SO(3) and M(2)SO(4) we have identified, and report, a series of unique linear relationships between the known Δ(f)H(o) and Δ(f)G(o) values of the alkali metal (M) sulfide (x = 0) and their oxyanion salts M(2)SO(x) (x = 3 and 4), and the similarly between M(2)S(2) disulfide (x = 0) and disulfur oxyanion salts M(2)S(2)O(x) (x = 3, 4, 5, 6 and 7) and the number of O atoms in their anions x. These linear relationships appear to be unique to sulfur compounds and their inherent simplicity permits us to interpolate thermochemical data (Δ(f)H(o)) for as yet unprepared compounds, M(2)SO (x = 1) and M(2)SO(2) (x = 2). The excellent linearity indicates the reliability of the interpolated data. Making use of the volume-based thermodynamics, VBT [Jenkins et al. (1999), Inorg. Chem. 38, 3609-3620], the values of the absolute entropies were estimated and from them, the standard Δ(f)S(o) values, and then the Δ(f)G(o) values of the salts. A tentative proposal is made for the synthesis of Na(2)SO(2) which involves bubbling SO(2) through a solution of sodium in liquid ammonia. For this attractive thermodynamic route, we estimate ΔG(o) to be approximately -500 kJ mol(-1). However, examination of the stability of Na(2)SO(2) raises doubts and Na(2)SeO(2) emerges as a more attractive target material. Its synthesis is likely to be easier and it is stable to disproportionation into Na(2)S and Na(2)SeO(4). Like Na(2)SO(2), this compound is predicted to have an anti-CaF(2) Na(2)Se subnet.

Characteristics and Effectiveness of Interventions That Target the Reporting, Communication, or Clinical Interpretation of Lumbar Imaging Findings: A Systematic Review.

BACKGROUND: Patients and clinicians may misinterpret the clinical importance of imaging findings in patients with low back pain, leading to potential harm related to overdiagnosis. PURPOSE: Our aims were to qualitatively summarize the characteristics of tested interventions that target the reporting, communication, or clinical interpretation of lumbar imaging findings and determine whether interventions are effective in improving low back pain-related health outcomes, health care use, or health care costs. DATA SOURCES: PubMed, MEDLINE, CINAHL, EMBASE, PsycINFO, and the Cochrane Library were searched from inception to October 20, 2021. STUDY SELECTION: The search retrieved 4394 articles, nine articles (seven studies) met the inclusion criteria to summarize intervention characteristics. Five of these studies had an adequate design for evaluating intervention effectiveness. DATA ANALYSES: Intervention characteristics were summarized using the Template for Intervention Description and Replication checklist. Effectiveness data were extracted from short, intermediate, and long-term follow-up points. Studies were assessed for risk of bias, and Grading of Recommendations Assessment, Development and Evaluation methodology was used to determine the certainty of the evidence. DATA SYNTHESIS: Four studies investigated the insertion of prevalence information into imaging reports. Single studies investigated withholding diagnostic information, education, and reassurance. Moderate-quality evidence (from 1 study) suggests that inserting prevalence information into imaging reports probably does not change the overall health care use in the long-term but may reduce opioid prescribing. LIMITATIONS: The available evidence is limited, and a meta-analysis was not possible. CONCLUSIONS: Further work is required to develop and test interventions that target the reporting, communication, and clinical interpretation of lumbar imaging findings that may reduce overdiagnosis and improve the management of low back pain.

Ambient isobaric heat capacities, C(p,m), for ionic solids and liquids: an application of volume-based thermodynamics (VBT).

Thermodynamic properties, such as standard entropy, among others, have been shown to correlate well with formula volume, V(m), thus permitting prediction of these properties on the basis of chemical formula and density alone, with no structural detail required. We have termed these procedures "volume-based thermodynamics" (VBT). We here extend these studies to ambient isobaric heat capacities, C(p,m), of a wide range of materials. We show that heat capacity is strongly linearly correlated with formula volume for large sets of minerals, for ionic solids in general, and for ionic liquids and that the results demonstrate that the Neumann-Kopp rule (additivity of heat capacity contributions per atom) is widely valid for ionic materials, but the smaller heat capacity contribution per unit volume for ionic liquids is noted and discussed. Using these correlations, it is possible to predict values of ambient (298 K) heat capacities quite simply. We also show that the heat capacity contribution of water molecules of crystallization is remarkably constant, at 41.3 ± 4.7 J K(-1) (mol of water)(-1), so that the heat capacities of various hydrates may be reliably estimated from the values of their chemical formula neighbors. This result complements similar observations that we have reported for other thermodynamic differences of hydrates.

Why are [P(C6H5)4](+)N3- and [As(C6H5)4](+)N3- ionic salts and Sb(C6H5)4N3 and Bi(C6H5)4N3 covalent solids? A theoretical study provides an unexpected answer.

A recent crystallographic study has shown that, in the solid state, P(C(6)H(5))(4)N(3) and As(C(6)H(5))(4)N(3) have ionic [M(C(6)H(5))(4)](+)N(3)(-)-type structures, whereas Sb(C(6)H(5))(4)N(3) exists as a pentacoordinated covalent solid. Using the results from density functional theory, lattice energy (VBT) calculations, sublimation energy estimates, and Born-Fajans-Haber cycles, it is shown that the maximum coordination numbers of the central atom M, the lattice energies of the ionic solids, and the sublimation energies of the covalent solids have no or little influence on the nature of the solids. Unexpectedly, the main factor determining whether the covalent or ionic structures are energetically favored is the first ionization potential of [M(C(6)H(5))(4)]. The calculations show that at ambient temperature the ionic structure is favored for P(C(6)H(5))(4)N(3) and the covalent structures are favored for Sb(C(6)H(5))(4)N(3) and Bi(C(6)H(5))(4)N(3), while As(C(6)H(5))(4)N(3) presents a borderline case.

Particle Analysis by Scanning Electron Microscopy With Energy Dispersive X-Ray Analysis in Pulmonary Pathology Specimens From U.S. Military Service Members Deployed During the Global War on Terror 2002 to 2015.

INTRODUCTION: Between 2001 and 2015, 2.77 million U.S. military service members completed over 5 million deployments to Southwest Asia. There are concerns that deployment-related environmental exposures may be associated with adverse pulmonary health outcomes. Accurate pulmonary diagnosis often requires histopathological biopsy. These lung biopsies are amenable to chemical analysis of retained particulates using scanning electron microscopy with energy dispersive X-ray analysis (SEM/EDXA). METHOD: A retrospective review of SEM/EDXA data collected in conjunction with pathologic diagnostic consultations at the Joint Pathology Center from 2011 to 2016 was conducted. Sections adjacent to those obtained for pathologic diagnosis were prepared for SEM/EDXA particle analysis, which provides qualitative identification of elements present in each particle and semiquantitative estimations of elemental weight percent. The review includes comparison of the particle analysis data and diagnostic findings, the particle count for the standard field analyzed, and types of particles identified. RESULTS: Nonneoplastic lung biopsy specimens from 25 deployed and 7 nondeployed U.S. service members were analyzed as part of the Joint Pathology Center pathologic consultations. The major exogenous particle types identified in both groups include aluminum silicates, other silicates, silica, and titanium dioxide. Endogenous particle types identified include calcium salts and iron-containing particles consistent with hemosiderin. These particles are present in deployed and nondeployed service members and are particle types commonly identified in lung biopsy specimens from urban dwelling adults. Rare particles containing other elements such as cerium and iron alloys were identified in some cases. Possible sources of these materials include diesel fuel and occupational and other environmental exposures. CONCLUSION: Scanning electron microscopy with energy dispersive X-ray particle analysis of inhaled particulates retained in lung tissue from deployed service members identifies particles commonly present in inhaled dust. In this small case series, we were not able to detect particle profiles that were common and unique to deployed patients only.