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High temperature corrosion of a Pt-30 wt.% Rh alloy in a phosphorizing gas was isothermally investigated at 1285 K using a gas switching technique. Diffusion of P into the alloy created an outer layer of Pt-rich liquid and blocky (Pt, Rh)2P precipitates along with an inner layer of fcc and (Pt, Rh)2P plates in a cellular microstructure. Concentration profiles measured by SEM-WDS and EPMA across the layers at room temperature showed that there were three fcc phases: first was a 12 at.% Rh phase in the outer layer; second was a 37 at.% Rh phase in the cellular microstructure; and third was the initial 43 at.% Rh alloy. Also, the EPMA data registered approximately 0.1 at.% P in fcc of these layers. Based on the surrounding binary phase diagrams and the experimental data obtained in this study, a partial Pt-Rh-P phase diagram was constructed. A diffusion path for the corrosion microstructure was drawn on the partial phase diagram to help develop a step by step model for how the microstructure evolved. Growth kinetics of the inner layer were used to calculate a P diffusivity of about 10−12 m2/s in the Pt-Rh alloy at 1285 K, suggesting rapid diffusion by either an interstitial or interstitialcy mechanism.

Alumina-supported Cu/Fe spinel particles were exposed to oxidation/reduction atmospheres at 800°C. Structural changes of the particles subjected to gas cycles between air and 10 vol.% CO-90 vol.% Ar were studied from physical data and real-time images collected using a confocal scanning laser microscope equipped with a heating chamber. Overall particle volume slowly expanded with cycles while surface roughness decreased. Cross-sections of the exposed particles showed segregation of Cu and Fe to the edges of inner grains, which may have acted as oxygen carriers during the exposures. The particles remained whole during the cyclic exposures without any noticeable structural breakdown.

Origins of onset and progression of motor neurodegeneration in amyotrophic lateral sclerosis (ALS) are not clearly known, but may include impairment of mitochondrial bioenergetics. We used quantitative PCR approaches to analyze the mitochondrial oxidative phosphorylation (OXPHOS) transcriptomes of spinal cord tissue and peripheral blood mononuclear cells (PBMC) from persons with sporadic ALS compared with those without neurological disease. Expression measurements of 88 different nuclear (n) and mitochondrial (mt) DNA-encoded OXPHOS genes showed mtDNA-encoded respiratory gene expression was significantly decreased in ALS spinal cord by 78-84% (ANOVA p < 0.002). We observed the same phenomenon in freshly isolated PBMC from ALS patients (reduced 24-35%, ANOVA p < 0.001) and reproduced it in a human neural stem cell model treated with 2',3'-dideoxycytidine (ddC) (reduced 52-78%, ANOVA p < 0.001). nDNA-encoded OXPHOS genes showed heterogeneously and mostly decreased expression in ALS spinal cord tissue. In contrast, ALS PBMC and ddC-treated stem cells showed no significant change in expression of nDNA OXPHOS genes compared with controls. Genes related to mitochondrial biogenesis (PGC-1α, TFAM, ERRα, NRF1, NRF2 and POLG) were queried with inconclusive results. Here, we demonstrate there is a systemic decrease in mtDNA gene expression in ALS central and peripheral tissues that support pursuit of bioenergetic-enhancing therapies. We also identified a combined nDNA and mtDNA gene set (n = 26), downregulated in spinal cord tissue that may be useful as a biomarker in the development of cell-based ALS models.

Gasification is a high-temperature, high-pressure chemical process used to convert a carbon feedstock into CO and H2 (syngas) for use in power generation and the production of chemicals. It is also a leading candidate as a source of hydrogen in a hydrogen economy and is one of several technologies expected to see increased use in advanced fossil fuel power systems in the future. Gasification is being evaluated because of its high efficiency, its ability to capture CO2 for sequestration or reuse in other applications, and its potential for carbon feedstock fuel flexibility. At the heart of the gasification process is a gasifier, a high pressure chemical reaction vessel used to contain the interactions between carbon and water in a shortage of oxygen, producing syngas. The gasifier is lined with high chrome oxide materials to protect the containment vessel. Gasifiers are complex systems, and failure of the refractories used to line them was identified by industry as a limitation to their reliability and availability and to their increased use. NETL researchers have examined spent high-Cr2O3 (over 90 pct Cr2O3) refractories from numerous gasifiers to determine in-service failure mechanisms. This analysis revealed that premature failure of the high chrome oxide refractories was related to ash in the carbon feedstock, which liquefies during gasification and interacts with the refractories, leading to wear by chemical dissolution or spalling (structural and chemical). A discussion of this postmortem wear of spent refractory materials and of thermodynamic modeling used to explain microstructural changes leading to wear are explained in this article. This information will serve the basis to develop improved performance refractory materials.

Many "classic" mitochondrial diseases have been described that arise from single homoplasmic mutations in mitochondrial DNA (mtDNA). These diseases typically affect nonmitotic tissues (brain, retina, muscle), present with variable phenotypes, can appear sporadically, and are untreatable. Evolving evidence implicates mtDNA abnormalities in diseases such as Alzheimer's, Parkinson's, and type II diabetes, but specific causal mutations for these conditions remain to be defined. Understanding the mtDNA genotype-phenotype relationships and developing specific treatment for mtDNA-based diseases is hampered by inability to manipulate the mitochondrial genome. We present a novel protein transduction technology ("protofection") that allows insertion and expression of the human mitochondrial genome into mitochondria of living cells. With protofection, the mitochondrial genotype can be altered, or exogenous genes can be introduced to be expressed and either retained in mitochondria or be directed to other organelles. Protofection also delivers mtDNA in vivo, opening the way to rational development of mitochondrial gene replacement therapy of mtDNA-based diseases.

Slag foaming is a steel-making process that has been shown to improve the efficiency of electric arc furnace plants. Unfortunately, slag foaming is a highly dynamic process that is difficult to control. This paper describes the development of an adaptive, intelligent control system for effectively manipulating the slag foaming process. The level-2 intelligent control system developed is based on three techniques from the field of computational intelligence (CI): (1) fuzzy logic, (2) genetic algorithms, and (3) neural networks. Results indicate that the computer software architecture presented in this paper is suitable for effectively manipulating complex engineering systems characterized by relatively slow process dynamics like those of a slag foaming operation.

Parkinson's disease patients may experience various gastrointestinal symptoms; however, the exact pathophysiology of these symptoms is not fully understood. Therefore, the aim of this study was to investigate the pattern of gastric myoelectrical activity in patients with Parkinson's disease. Eleven patients with Parkinson's disease and 10 healthy subjects participated in the study. Patients were stratified as "receiving dopaminergic therapy" (N = 5) and "off therapy" (N = 6). Gastric myoelectrical activity was measured by means of surface electrogastrography (EGG) for 30 min before and for 90 min after a standardized meal. The dominant frequency, postprandial EGG power change, and the percentage of normal 2-4 cycles/min (cpm) slow-wave activity in the three groups were calculated and compared. The mean postprandial EGG power increase in the untreated patients was smaller than in the treated patients (-3.11 +/- 1.01 and 1.17 +/- 1.96 dB; P = 0.072). Moreover, both of these values were significantly decreased when compared to the control group (untreated vs control: -3.11 +/- 1.01 vs 8.01 +/- 1.86 dB; P = 0.04 and treated vs control: 1.17 +/- 1.96 vs 8.01 +/- 1.86 dB; P = 0.02). The percentage of normal 2-4 cpm slow waves in untreated patients was not different from the treated patients (82.6 +/- 6.6% vs 75.8 +/- 13.6%, P = NS) or from the control group (88.2 +/- 5.4%, P = NS). The dominant frequency after the meal was similar to that in the fasting state both in the untreated (3.3 +/- 0.1 vs 3.2 +/- 0.2 cpm; P = NS) and treated patients (3.2 +/- 0.1 vs 3.1 +/- 0.1 cpm, P = NS), whereas the dominant frequency significantly increased postprandially in the control group (2.88 +/- 0.12 vs 3.05 +/- 0.16; P < 0.05). Abnormalities in gastric myoelectrical activity in untreated Parkinson's disease patients reflect direct involvement of the gastrointestinal tract by the primary disease process. EGG can be regarded as a useful diagnostic tool in evaluating gastrointestinal involvement in neurodegenerative diseases.

The long-term use of dopamine replacement therapy leads to dyskinesias in some Parkinson’s disease (PD) patients, which may be specific to the D1 subtype of dopamine (DA) receptor. The purpose of this study was to test the effectiveness of a D2-specific DA agonist, Pramipexole, in PD patients. In a double-blind design, 6 patients took increasing doses of Pramipexole over the course of 24 weeks, and were tested in a total of 15 sessions on four measures of movement efficacy: tapping speed, simple response time, choice response time, and sequencing. Compared with 3 placebo control patients, those on active medication showed faster tapping speeds and simple response times. Choice response time and sequencing were not affected by medication status. The D2 subtype of DA receptor may be especially important in movement speed, and may contribute less to more cognitive aspects of movement.

The second edition of theManual of Vascular Plants of Northeastern United States and Adjacent Canada by Gleason and Cronquist (1991) is the most recent and up-to-date taxonomic treatment of the flora of that region. Since no floristic summary of theManual was included in the publication, a computer analysis of the taxonomic data of theManual was performed in order to generate a floristic summary. Totals of 4285 species, 1091 genera, and 191 families were tabulated. The largest genus wasCarex, with 230 species; the largest family was the Asteraceae, with 528 species. Comparisons made with earlier floras of the same region indicated small declines on the order of 10% for these taxonomic groups.

A thorough review and critical evaluation of field surveys from 1900 to the present of foliar injury to Pinus strobus L. supposedly caused by air pollution was undertaken. Ninety percent of the surveys failed to meet current scientific standards of acceptability. The conduct and peer review of surveys has been poor and the correct injury symptoms have not always been used. Data were obtained for nine that met screening criteria and injury incidence and severity were mapped. Three fourths of the counties in the natural and planted range of eastern white pine have not been scientifically surveyed, so generalizations regarding large-scale spatial patterns of eastern white pine foliar pathological conditions were not possible. However, recent growth and inventory data indicate that growth throughout the natural range regardless of air pollution or other stresses (e.g. blister rust) is excellent, suggesting that regional performance and foliar conditions are unrelated. Sufficient compelling corroborative evidence was found to conclude that a general decline of eastern white pine throughout its range is not a tenable finding. The putative air pollution sensitivity of eastern white pine appears to be based on studies published between 1963 and 1973 on hypersensitive individuals that are no longer being observed in the field. More recent research on eastern white pine has noted a lack of sensitivity and/or high variability of response. The idea that eastern white pine as a species is highly sensitive to air pollution is no longer supported by the available evidence. However, hypersensitive juvenile individuals comprising no more than 8–9% of the total population may still germinate and grow for a brief period of time (because old enough parent trees are still alive) but soon succumb to current levels of ozone and sulfur dioxide in the environment or are suppressed by tolerant neighbors. This phenomenon has been documented anecdotally and is more aptly called tree decline instead of forest decline. An emerging working hypothesis to explain recent reports of unusual eastern white pine tolerance is that sufficient time has elapsed for tree decline to have occurred leading to a gradual elimination of sensitive genotypes from populations.

Background Parkinson's disease, the most common adult neurodegenerative movement disorder, demonstrates a brain-wide pathology that begins pre-clinically with alpha-synuclein aggregates ("Lewy neurites") in processes of gut enteric and vagal motor neurons. Rostral progression into substantia nigra with death of dopamine neurons produces the motor impairment phenotype that yields a clinical diagnosis. The vast majority of Parkinson's disease occurs sporadically, and current models of sporadic Parkinson's disease (sPD) can utilize directly infused or systemic neurotoxins. Results We developed a differentiation protocol for human SH-SY5Y neuroblastoma that yielded non-dividing dopaminergic neural cells with long processes that we then exposed to 50 nM rotenone, a complex I inhibitor used in Parkinson's disease models. After 21 days of rotenone, ~60% of cells died. Their processes retracted and accumulated ASYN-(+) and UB-(+) aggregates that blocked organelle transport. Mitochondrial movement velocities were reduced by 8 days of rotenone and continued to decline over time. No cytoplasmic inclusions resembling Lewy bodies were observed. Gene microarray analyses showed that the majority of genes were under-expressed. qPCR analyses of 11 mtDNA-encoded and 10 nDNA-encoded mitochondrial electron transport chain RNAs' relative expressions revealed small increases in mtDNA-encoded genes and lesser regulation of nDNA-encoded ETC genes. Conclusion Subacute rotenone treatment of differentiated SH-SY5Y neuroblastoma cells causes process retraction and partial death over several weeks, slowed mitochondrial movement in processes and appears to reproduce the Lewy neuritic changes of early Parkinson's disease pathology but does not cause Lewy body inclusions. The overall pattern of transcriptional regulation is gene under-expression with minimal regulation of ETC genes in spite of rotenone's being a complex I toxin. This rotenone-SH-SY5Y model in a differentiated human neural cell mimics changes of early Parkinson's disease and may be useful for screening therapeutics for neuroprotection in that disease stage.

THE molecular mechanism responsible for the therapeutic activity of a drug is often suggested by the biochemical event which correlates best with clinical potency. Thus, if optical or geometrical isomers of a drug have markedly different clinical potencies, the most relevant biochemical effect should also exhibit isomeric specificity.

In the tidal Potomac River, high river discharges during the spring are associated with high chlorophylla concentrations in the following in the following summer, assuming that summertime light and temperature conditions are favorable. Spring floods deliver large loads of particulate N and P to the tidal river. This particulate N and P could be mineralized by bacteria to inorganic N and P and released to the water column where it is available for phytoplankton use during summertime. However, during the study period relatively low concentrations of chlorophylla (less than 50 μg l−1 occurred in the tidal river if average monthly discharge during July or August exceeded 200 m3s−1. Discharge and other conditions combined to produce conditions favorable for nuisance levels of chlorophylla (greater than 100 μg l−1 approximately one year out of four. Chlorophylla maxima occurred in the Potomac River transition zone and estuary during late winter (dinoflagellates) and spring (diatoms). Typical seasonal peak concentrations were achieved at discharges as high as 970 m3 s−1, but sustained discharges greater than 1,100 m3 s−1 retarded development. Optimum growth conditions occurred following runoff events of 10 to 15 d duration which produced transit times to the transition zone of 7 to 10 d. Wet years with numerous moderate-sized runoff events, such as 1980, tend to produce greater biomass in the transition zone and estuary than do dry years such as 1981.