Molecular Aluminum Additive for Burn Enhancement of Hydrocarbon Fuels.

Additives to hydrocarbon fuels are commonly explored to change the combustion dynamics, chemical distribution, and/or product integrity. Here we employ a novel aluminum-based molecular additive, Al(I) tetrameric cluster [AlBrNEt3]4 (Et = C2H5), to a hydrocarbon fuel and evaluate the resultant single-droplet combustion properties. This Al4 cluster offers a soluble alternative to nanoscale particulate additives that have recently been explored and may mitigate the observed problems of particle aggregation.

Flow reactor studies of non-equilibrium plasma-assisted oxidation of n-alkanes.

The oxidation of n-alkanes (C1-C7) has been studied with and without the effects of a nanosecond, non-equilibrium plasma discharge at 1 atm pressure from 420 to 1250 K. Experiments have been performed under nearly isothermal conditions in a flow reactor, where reactive mixtures are diluted in Ar to minimize temperature changes from chemical reactions. Sample extraction performed at the exit of the reactor captures product and intermediate species and stores them in a multi-position valve for subsequent identification and quantification using gas chromatography.

Design, fabrication and analysis of stagnation flow microreactors used to study hypergolic reactions.

A novel method to study the condensed phase reactions that occur during the ignition of hypergolic propellants (very fast liquid reactions) using microreactors is presented. Planar counterflow microreactors are used to isolate liquid-phase reactions and diffusion from secondary gas-phase chemical and transport processes that often occur concurrently during the overall ignition process. The counterflow microreactor has made it possible to achieve valuable insight into the preignition mechanisms of hypergolic propellants hitherto not possible using conventional drop or impinging jet tests.

Enhanced thermal decomposition of nitromethane on functionalized graphene sheets: ab initio molecular dynamics simulations.

The burning rate of the monopropellant nitromethane (NM) has been observed to increase by adding and dispersing small amounts of functionalized graphene sheets (FGSs) in liquid NM. Until now, no plausible mechanisms for FGSs acting as combustion catalysts have been presented. Here, we report ab initio molecular dynamics simulations showing that carbon vacancy defects within the plane of the FGSs, functionalized with oxygen-containing groups, greatly accelerate the thermal decomposition of NM and its derivatives.

ReaxFF reactive force field development and applications for molecular dynamics simulations of ammonia borane dehydrogenation and combustion.

Ammonia borane (AB) has attracted significant attention due to its high hydrogen content (19.6% by mass). To investigate the reaction mechanism associated with the combustion of AB, a reactive force field (ReaxFF) has been developed for use in molecular dynamics (MD) simulations.

Electrostatically self-assembled nanocomposite reactive microspheres.

Nanocomposite reactive microspheres with diameters of approximately 1-5 mum were created via electrostatic self-assembly of aluminum and cupric oxide nanoparticles. The ability to utilize this novel approach of bottom-up assembly to create these reactive materials allows for the potential for a more intimate mixture between the two nanoreactants and, thus, an overall more energetic combustion process. Experiments with the self-assembled material demonstrate the ability to achieve ignition and sustain a combustion wave in rectangular microchannels, which does not occur with material having similar amounts of organics mixed via the traditional sonication method.

Functionalized graphene sheet colloids for enhanced fuel/propellant combustion.

We have compared the combustion of the monopropellant nitromethane with that of nitromethane containing colloidal particles of functionalized graphene sheets or metal hydroxides. The linear steady-state burning rates of the monopropellant and colloidal suspensions were determined at room temperature, under a range of pressures (3.35-14.

A novel electrolytic ignition monopropellant microthruster based on low temperature co-fired ceramic tape technology.

A planar 2-D liquid monopropellant microthruster fabricated from low temperature co-fired ceramic tapes and ignited by electrolysis is reported. The volume of the combustion chamber was 820 nL (0.82 mm(3)).

Effects of exogenous, nonleukemogenic, ecotropic murine leukemia virus infections on the immune systems of adult C57BL/6 mice.

Mouse AIDS (MAIDS) develops in mice infected with a mixture of replication-competent ecotropic and mink lung cell focus-inducing murine leukemia viruses and an etiologic replication-defective virus. Helper viruses are not required for induction of MAIDS, but the time course of disease is accelerated in their presence. To understand the possible contributions of ectropic murine leukemia viruses to MAIDS pathogenesis, we biologically cloned a series of viruses from the MAIDS-inducing LP-BM5 virus mixture.

Liver cell dysplasia: a DNA aneuploid lesion with distinct morphologic features.

Liver cell dysplasia is characterized by hepatocellular foci with nuclear atypia. It is often seen in cirrhosis and may be a precursor of hepatocellular carcinoma (HCC). To determine whether liver cell dysplasia is DNA aneuploid, 72 sections of 33 cirrhotic livers from the autopsy files of The Johns Hopkins Hospital were studied, and 14 foci of dysplasia from 13 cirrhotic livers were selected.

Multiparameter DNA flow cytometry of keratoacanthoma.

Keratoacanthomas (KAs) are rapidly growing cutaneous lesions that frequently look much like well-differentiated squamous cell carcinomas (SCCs) but spontaneously regress. It is uncertain whether KA is a reactive hyperplastic lesion that mimics a neoplasm or a true (but defective) neoplasm that cannot sustain progressive growth. To address this question, we performed DNA flow cytometric analysis on 14 KAs and 10 cutaneous SCCs for comparison.

Epithelioid component of uterine leiomyosarcoma simulating metastatic carcinoma.

A variant of uterine leiomyosarcoma containing two morphologic bell populations is described. A smooth-muscle component with a mitotic rate of 13 per 10 high-power fields, and a second population of cells mimicking metastatic small-cell carcinoma were both present. The second population was composed of small angulated epithelioid cells with hyperchromatic nuclei and barely discernible cytoplasm growing in tight rows, often in single file between fascicles of smooth muscle.

ZDV delays but does not prevent the transmission of MAIDS by LP-BM5 MuLV-infected macrophage-monocytes.

LP-BM5 MuLV infection of monocyte-macrophages (MM cells) and the ability of MM cells infected with this murine oncornavirus complex to transmit murine acquired immune deficiency syndrome (MAIDS) were assessed. Adherent cells expressing Mac-1 antigen (Mac-1+) were isolated from the peritoneum of infected C57BL/6 mice at weekly intervals postinoculation. A small percentage of MM cells was infected by 7 days after inoculation with LP-BM5 MuLV and virus production could be detected in MM cells throughout the course of disease.

Clear cell dysplasia of the bladder. Report of a case with flow cytometric analysis.

Clear cell dysplasia of the bladder is a well-described morphologic entity that has been found in association with transitional cell carcinoma of the bladder. Its biologic role in bladder tumorigenesis is unknown, and no instances of its polidy analysis have been reported. The authors describe a case of clear cell dysplasia of the bladder found in association with a primary adenocarcinoma of the bladder.

Effect of 3'azidothymidine administered in drinking water or by continuous infusion on the development of MAIDS.

LP-BM5 MuLV infection of C57BL/6 mice induces a well characterized, lymphoproliferative, immunodeficiency disease (MAIDS), which is useful for evaluation of potential antiviral agents, because of the reproducibility of virological and clinical endpoints. This MAIDS retrovirus model was used to evaluate 3'azido-2,3'dideoxythymidine (AZT), using different doses, methods of administration and timing for initiation and continuation of therapy. AZT therapy 1 mg/ml in the drinking water given 30 days prior to virus challenge, and continued for 16 weeks, prevented LP-BM5 MuLV dissemination and disease in 13 of 15 treated mice.

DNA analysis of cardiac myxomas: flow cytometry and image analysis.

Cardiac myxoma is the most common primary tumor of heart, but there is a longstanding controversy over whether it is a true neoplasm or a reactive lesion. We analyzed 24 cardiac myxomas from 22 patients: 22 by DNA flow cytometry and five by image analysis. Two myxomas were aneuploid; one of those analyzed by flow cytometry, and the other by image analysis.

Functional and phenotypic alterations in T cell subsets during the course of MAIDS, a murine retrovirus-induced immunodeficiency syndrome.

The functional and phenotypic characteristics of Ly-4(CD4)+ and Ly-2(CD8)+ T cells were studied after induction of murine AIDS with LP-BM5 murine leukemia virus. Assays of spleen cells for their ability to generate in vitro CTL responses to TNP-modified autologous cells (self + x CTL) and to alloantigens (allo CTL) showed that self + x CTL responses were greatly impaired at 3 to 4 wk postinfection and were undetectable thereafter. Allo CTL responses were normal at 3 to 4 wk, but were reduced at 8 to 9 wk and absent at 14 wk postinfection.

Retrovirus-induced murine acquired immunodeficiency syndrome: natural history of infection and differing susceptibility of inbred mouse strains.

C57BL mice (Fv-1b) develop a severe immunodeficiency disease following inoculation as adults with LP-BM5 murine leukemia virus (MuLV), a derivative of Duplan-Laterjet virus which contains B-tropic ecotropic and mink cell focus-inducing MuLVs and a putative defective genome which may be the proximal cause of disease. The stages of development of this disease were defined for C57BL mice on the basis of lymphadenopathy and splenomegaly; histopathological changes consistent with B-cell activation; and alterations in expression of cell surface antigens affected by proliferation of T cells, B cells, and macrophages. By using this disease profile as a standard, the response of adult mice of various inbred strains and selected F1 hybrids was compared.

Abnormal regulation of IFN-alpha, -beta, and -gamma expression in MAIDS, a murine retrovirus-induced immunodeficiency syndrome.

Mice infected with LP-BM5 murine leukemia viruses (MuLV) develop a syndrome with many features in common with AIDS including lymphadenopathy and profound immunodeficiency associated with enhanced susceptibility to infection and terminal B cell lymphomas. To evaluate cellular defects that may predispose infected mice to these sequelae, we studied the regulation of IFN gene expression. Spleen cells from mice infected with LP-BM5 MuLV expressed high levels of IFN-gamma mRNA by 1 wk post-inoculation and throughout the course of disease.

Expression and modulation of a retrovirus-associated antigen by murine melanoma cells.

The antigen recognized by the monoclonal antibody MM2-9B6 is specific for melanomas originating in C57BL/6 mice. It is expressed by three melanomas of independent origin and not by normal or fetal tissues, by a wide variety of other nonmelanoma tumors in C57BL/6 mice, or even by melanomas syngeneic to other strains of mice. We have demonstrated that the expression of the relevant antigen is dependent on the replication and budding of a B-tropic ecotropic murine retrovirus.

CD4+ T cells are required for development of a murine retrovirus-induced immunodeficiency syndrome (MAIDS).

Mice depleted in vivo of CD4+ Th cells by treatment with mAb GK1.5 were found to be resistant to the lymphoproliferative/immunodeficiency disease (MAIDS) induced in intact mice by infection with the mixture of LP-BM5 murine leukemia viruses. Depleted mice did not develop lymphadenopathy or splenomegaly, had normal serum IgM levels, normal CTL responses to alloantigens, and were able to generate PFC responses to Th-independent antigens even though frequencies of virus-producing spleen cells were comparable in depleted and intact mice.

Passive serum antibody causes temporary recovery from influenza virus infection of the nose, trachea and lung of nude mice.

BALB/c normal and nude mice were infected with a non-lethal mouse-passaged A/PC/1/73 (H3N2) influenza virus in order to assess the role of T cells on the course of disease of the nose, trachea and lung. The tracheal epithelium of both mouse strains was desquamated by 3 days after infection. Although normal regeneration began, nude mice never completed that regeneration whereas normal mice had fully regenerated tracheas by Day 14.

Evolution of B cell lineage lymphomas in mice with a retrovirus-induced immunodeficiency syndrome, MAIDS.

Mice infected with LP-BM5 murine leukemia virus develop lymphadenopathy, splenomegaly, hypergammaglobulinemia, and profound immunosuppression associated with enhanced susceptibility to infection. In this study, molecular genetic analyses of spleen and lymph node cells from infected mice showed the early course of disease was associated with polyclonal proliferations of both B and T cells but that by 12 wk oligoclonal expansions of B or T cells could be detected. When near death, the mice were killed and almost all exhibited clonally restricted populations of B cells, and continuous cultures of B lineage cells were established from three of 19 mice.

Functional T lymphocytes are required for a murine retrovirus-induced immunodeficiency disease (MAIDS).

Athymic nu/nu mice were found to be resistant to the immunodeficiency disease and lethality induced in normal mice by the injection of the LP-BM5 mixture of murine retroviruses (LP-BM5 MuLV). Susceptibility to disease induction was reconstituted by injection of nu/nu mice with purified, mature T lymphocytes. The extent of viral replication of both the ecotropic and mink cell focus forming (MCF) components of LP-BM5 MuLV was equivalent in both nu/nu and normal animals.

Abrogation of resistance to severe mousepox in C57BL/6 mice infected with LP-BM5 murine leukemia viruses.

Strain C57BL/6 (B6) mice infected with LP-BM5 murine leukemia virus (MuLV) develop a disease which combines abnormal lymphoproliferation with profound immunosuppression and has many features in common with human acquired immunodeficiency syndrome induced by HTLV-III/LAV retroviruses. To determine whether this LP-BM5 MuLV infection would affect the innate resistance of B6 mice to a naturally occurring, highly virulent murine pathogen, mice were exposed to ectromelia virus at various times after treatment with LP-BM5 viruses. At week 4 after infection with LP-BM5, mice challenged with ectromelia virus were unable to generate a humoral immune response to this virus, and between weeks 8 and 10 after infection, challenged mice lost the ability to generate an ectromelia virus-specific cytotoxic-T-cell response.