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In spite of the importance of energetic materials to a broad range of military (munitions, missiles) and civilian (mining, space exploration) technologies, the introduction of new chemical entities in the field occurs at a very slow pace. This situation is understandable considering the stringent requirements for cost and safety that must be met for new chemical entities to be fielded. If existing manufacturing infrastructure could be leveraged, then this would offer a fundamental shift in the discovery paradigm. Cocrystallization is an approach poised to realize this goal because it can use existing materials and make new chemical compositions through the assembly of multiple unique components in the solid state. This account describes early proof-of-principle studies with widely used energetics in the field, including 2,4,6-trinitrotoluene (TNT) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), forming cocrystals with nonenergetic coformers that alter key properties such as density, sensitivity, and morphology. The evolution of these studies to produce cocrystals between two energetic components is detailed, including those exploiting new intermolecular interaction motifs that drive assembly such as halogen bonding. Implications of cocrystallization for performance, sensitivity to external stimuli, and manufacturability are explored at each stage. The derivation of many of these cocrystals from energetic materials in common use satisfies the goal of using materials already demonstrated to be cost-effective at scale and with well-understood safety profiles. The account concludes with a discussion of cocrystallizing molecules having excess of oxidizing power with those that are oxygen-deficient to push the limits of explosive performance to unprecedented levels. The purposeful production of an arbitrary combination of two solid components into a cocrystal is far from certain, but the studies described motivate the continued exploration of novel materials and the development of predictive models for identifying crystallization partners. When such cocrystals form, many of their most important properties cannot be predicted, pointing to another challenge for the purposeful development of energetic materials based on cocrystallization.

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The decomposition behavior of high energy metal-organic frameworks (MOFs) with extensive nitration is disclosed. In contrast to the detonation behavior observed in molecular energetic compounds, deflagration transforms cubic MOFs into anisotropic carbon structures with highly dispersed metal. Both the structural metal and intimate mixing are found to be critical.

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An energetic cocrystal is described between 3,4-diaminofurazan (DAF) and 4-amino-3,5-dinitropyrazole (ADNP). The material is remarkable because interaction between the components leads to melting behavior and melt-state stabilization (absent in ADNP), that allows a melt castable formulation with explosive performance superior to DAF. This provides another potential advantage of cocrystallization for energetic materials.

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Two polymorphic hydrogen peroxide solvates of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20; wurtzitane is an alternative name to iceane) were obtained using hydrated α-CL-20 as a guide. These novel H2 O2 solvates have high crystallographic densities (1.96 and 2.03 g cm-3 , respectively), high predicted detonation velocities/pressures (with one solvate performing better than ϵ-CL-20), and a sensitivity similar to that of ϵ-CL-20. The use of hydrated materials as a guide will be important in the development of other energetic materials with hydrogen peroxide. These solvates represent an area of energetic materials that has yet to be explored.

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Adsorption of oxidizing guest molecules into a non-energetic microporous coordination polymer produces explosives with desirable oxygen balance, high heat released upon decomposition, and suppressed vapor pressure of the guest. Here, this results in primary explosives, materials very sensitive to impact, that have the potential to be used as replacements for lead-based initiators.

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A series of single-walled carbon nanotube precursors, C3h-symmetric cyclotri(ethynylene)(biphenyl-2,4'-diyl) and cyclotri(ethynylene)(p-terphenyl-2,4″-diyl), have been prepared by a linear stepwise oligomerization-cyclization route and by statistical intermolecular cyclooligomerization. In addition to producing these members of a novel class of arylene ethynylene macrocycles, 1 and 2, the latter statistical process produces the smaller cyclic dimer, cyclodi(ethynylene)(p-terphenyl-2,4″-diyl) and the larger cyclic tetramer cyclotetra(ethynylene)(biphenyl-2,4'-diyl). These macrocycles display large Stokes shifts in their fluorescence spectra. Their biphenyl or terphenyl connectivity prevents these macrocycles from achieving full planarity in the ground state, and the ethynylene moieties could provide synthetic access to cyclic arylene oligomers and discrete carbon nanotube segments.

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OBJECTIVE: We assessed demographic and temporal trends of tuberculosis (TB)-related deaths in the United States and examined associated comorbidities listed on death certificates. METHODS: We analyzed TB-related mortality from 1990 through 2006 by examining multiple-cause-of-death data from the National Center for Health Statistics. We assessed age-adjusted mortality rates, secular trends, associations with demographic variables, and comorbid conditions. RESULTS: From 1990 through 2006, TB was reported as a cause of death among 53,505 people in the U.S. with a combined overall mean age-adjusted mortality rate of 1.16 per 100,000 person-years. The age-adjusted TB mortality rate declined from 2.22 per 100,000 person-years in 1990 to 0.47 per 100,000 person-years in 2006, demonstrating mean annual decline of about 10%. People aged 75 years and older; males; foreign-born people; and those of Hispanic, Asian, black, and Native American race/ethnicity had comparatively elevated TB-related mortality rates. The mortality rate in foreign-born people was more than two times higher than in U.S.-born people. About 89% of deaths among people of Asian race/ethnicity and nearly 50% among black people were foreign-born individuals. Human immunodeficiency virus and selected autoimmune diseases were more common in TB-related deaths. CONCLUSIONS: TB mortality decreased substantially from 1990 through 2006, but remains an important cause of preventable mortality. The observed decrease was more pronounced among U.S.-born people than among foreign-born people. Disparities in TB-related mortality and the identification of important comorbid conditions can inform strategies targeting subpopulations at increased risk for fatal TB infection.

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PURPOSE: Recent studies have reported a connection between glaucoma and decreased survival. To evaluate the underlying causes of glaucoma-related mortality, we searched vital records data for deaths citing glaucoma and reviewed the demographic variables and comorbidities contained on these records. MATERIALS AND METHODS: Deaths including glaucoma, as either an underlying cause or a contributing cause of death, were selected from US multiple-cause-of-death data for the years 1990 to 2003 and combined with population data from the US Census Bureau to calculate mortality rates. Logistic regression was used to determine whether reporting of accidents and/or selected systemic disorders are associated with glaucoma on the death certificate. RESULTS: Fifteen thousand two hundred twenty-eight glaucoma-related deaths (0.05%) were identified during the years under study. Black males had the highest glaucoma-related mortality rate with 9.4 deaths per 1,000,000 persons annually, whereas Hispanic females had the lowest mortality rate at 1.8 deaths per 1,000,000. After adjusting for age, sex, and race/ethnicity, positive associations were found between glaucoma and hypertension [Odds ratio (OR): 4.89; 95% confidence interval (CI)=4.73-5.05], diabetes (OR: 2.60; 95% CI=2.50-2.71), asthma (OR: 3.14; 95% CI=2.72-3.62), and accidents of all types (OR: 1.45; 95% CI=1.35-1.55). CONCLUSIONS: Glaucoma is an important contributor to mortality for certain individuals. The disparities in mortality rates observed among race/ethnic strata may be attributed to differences in access to care as well as true differences in disease incidence and/or severity among racial groups. Despite limitations with the data, our findings suggest associations between glaucoma and a number of comorbid conditions. These associations should be explored in future studies and serve to guide strategies for disease management and prevention.

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BACKGROUND: Listeria monocytogenes is among the most virulent foodborne pathogens, with 20% of clinical infections resulting in death. To explore listeriosis-associated mortality in the United States and to evaluate prevention efforts, we reviewed vital records over a 16-year period to assess demographic, temporal, and seasonal trends. METHODS: Nonperinatal listeriosis-associated deaths from 1990 through 2005 were identified from multiple-cause-coded death records and were combined with US census data to calculate mortality rates. Poisson regression was used to model time trends, and logistic regression was used to identify comorbid conditions associated with listeriosis on the death record. RESULTS: Of the 37,267,946 deaths occurring in the United States during the 16-year study period, 1178 included listeriosis on the death record. Listeriosis-related mortality rates decreased annually by 10.74% from 1990 through 1996 and by 4.26% from 1996 through 2005. Seasonal trends show a distinct peak in mortality from July through October. After adjustment for age, sex, and race/ethnicity, listeriosis was positively associated with human immunodeficiency virus (HIV) infection (odds ratio, 4.19; 95% confidence interval, 3.06-5.73), lymphoid and hematopoietic cancers (odds ratio, 5.27; 95% confidence interval, 4.47-6.22), and liver disease (odds ratio, 2.05; 95% confidence interval, 1.54-2.73) on the death record. CONCLUSIONS: Nonperinatal listeriosis-associated deaths in the United States have decreased, paralleling a decreasing trend in incidence. Strict monitoring of food manufacturing processes, as well as improved treatment for HIV infection, may have played influential roles in preventing human infections. Health care providers should be aware of seasonal listeriosis patterns, as well as conditions predisposing individuals to severe infection and death due to L. monocytogenes infection, to guide strategies for disease management and prevention.

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RATIONALE: In late October 2003, Southern California wildfires burned more than 3,000 km2. The wildfires produced heavy smoke that affected several communities participating in the University of Southern California Children's Health Study (CHS). OBJECTIVES: To study the acute effects of fire smoke on the health of CHS participants. METHODS: A questionnaire was used to assess smoke exposure and occurrence of symptoms among CHS high-school students (n = 873; age, 17-18 yr) and elementary-school children (n = 5,551; age, 6-7 yr), in a total of 16 communities. Estimates of particulate matter (PM10) concentrations during the 5 d with the highest fire activity were used to characterize community smoke level. MAIN RESULTS: All symptoms (nose, eyes, and throat irritations; cough; bronchitis; cold; wheezing; asthma attacks), medication usage, and physician visits were associated with individually reported exposure differences within communities. Risks increased monotonically with the number of reported smoky days. For most outcomes, reporting rates between communities were also associated with the fire-related PM10 levels. Associations tended to be strongest among those without asthma. Individuals with asthma were more likely to take preventive action, such as wearing masks or staying indoors during the fire. CONCLUSIONS: Exposure to wildfire smoke was associated with increased eye and respiratory symptoms, medication use, and physician visits.

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