15 research outputs found
Recommended from our members
New composite separator pellet to increase power density and reduce size of thermal batteries.
We show that it is possible to manufacture strong macroporous ceramic films that can be backfilled with electrolyte to form rigid separator pellets suitable for use in thermal batteries. Several new ceramic manufacturing processes are developed to produce sintered magnesium oxide foams with connected porosities of over 80% by volume and with sufficient strength to withstand the battery manufacturing steps. The effects of processing parameters are quantified, and methods to imbibe electrolyte into the ceramic scaffold demonstrated. Preliminary single cell battery testing show that some of our first generation pellets exhibit longer voltage life with comparable resistance at the critical early times to that exhibited by a traditional pressed pellets. Although more development work is needed to optimize the processes to create these rigid separator pellets, the results indicate the potential of such ceramic separator pellets to be equal, if not superior to, current pressed pellets. Furthermore, they could be a replacement for critical material that is no longer available, as well as improving battery separator strength, decreasing production costs, and leading to shorter battery stacks for long-life batteries
Prevalence of a loss-of-function mutation in the proton-coupled folate transporter gene (PCFT-SLC46A1) causing hereditary folate malabsorption in Puerto Rico
OBJECTIVE: To determine whether subjects of Puerto Rican heritage are at increased risk for a specific mutation of the proton-coupled folate transporter (PCFT) causing hereditary folate malabsorption (HFM).
STUDY DESIGN: Three percent of the births in Puerto Rico in 2005, with additional regional oversampling, were screened for the prevalence of the c.1082G\u3eA; p.Y362_G389 del PCFT gene mutation. Six new subjects of Puerto Rican heritage with the clinical diagnosis of HFM were also assessed for this mutation.
RESULTS: Six subjects of Puerto Rican heritage with the clinical diagnosis of HFM were all homozygous for the c.1082G\u3eA; p.Y362_G389 del PCFT mutation. Three heterozygote carriers were identified from the 1582 newborn samples randomly selected from births in Puerto Rico in 2005. The carrier frequency for the mutated allele was 0.2% island-wide and 6.3% in Villalba.
CONCLUSION: These findings are consistent with a common mutation in the PCFT gene causing HFM that has disseminated to Puerto Ricans who have migrated to mainland United States. Because prompt diagnosis and treatment of infants with HFM can prevent the consequences of this disorder, newborn screening should be considered in high-risk populations and physicians should be aware of its prevalence in infants of Puerto Rican ancestry
Analysis of age-related changes in psychosine metabolism in the human brain
<div><p>α-Synuclein aggregation has been linked to Gaucher’s disease (GD) and Krabbe’s disease (KD), lysosomal conditions affecting glycosphingolipid metabolism. α-Synuclein pathology has been directly attributed to the dysregulation of glycosphingolipids in both conditions, specifically to increased galactosylsphingosine (psychosine) content in the context of KD. Furthermore, the gene (<i>GALC</i>) coding for the psychosine degrading enzyme galactosylceramidase (GALC), has recently been identified as a risk loci for Parkinson’s disease. However, it is unknown if changes in psychosine metabolism and GALC activity in the context of the aging human brain correlate with Parkinson’s disease. We investigated psychosine accumulation and GALC activity in the aging brain using fresh frozen post-mortem tissue from Parkinson’s (PD, n = 10), Alzheimer’s (AD, n = 10), and healthy control patients (n = 9), along with tissue from neuropsychiatric patients (schizophrenia, bipolar disorder and depression, n = 15 each). An expanded mutational analysis of PD (n = 20), AD (n = 10), and healthy controls (n = 30) examined if PD was correlated with carriers for severe <i>GALC</i> mutations. Psychosine content within the cerebral cortex of PD patients was elevated above control patients. Within all patients, psychosine displayed a significant (p<0.05) and robust regional distribution in the brain with higher levels in the white matter and substantia nigra. A mutational analysis revealed an increase in the incidence of severe <i>GALC</i> mutations within the PD patient population compared to the cohorts of Alzheimer’s patients and healthy controls tested. In addition to α-synuclein pathology identified in the KD brain, control patients identified as GALC mutational carriers or possessing a GALC pathogenic variant had evidence of α-synuclein pathology, indicating a possible correlation between α-synuclein pathology and dysregulation of psychosine metabolism in the adult brain. Carrier status for <i>GALC</i> mutations and prolonged exposure to increased psychosine could contribute to α-synuclein pathology, supporting psychosine metabolism by galactosylceramidase as a risk factor for Parkinson’s disease.</p></div
Immunohistological staining for α-synuclein.
<p>Immunohistological staining for α-synuclein was performed in brain tissue from 3 infantile KD patients (A-C), a late-onset KD patient (D), 2 patients found to be <i>GALC</i> mutation/variant carriers with no neurological disorders previously diagnosed (E,F), a Parkinson’s patient (G), and a healthy control with no <i>GALC</i> mutations (H). Accumulations of α-synuclein were observed in all Krabbe patients (A-D), the Parkinson’s brain (G), and also within the brains of <i>GALC</i> mutation/variant carriers (E,F). Accumulations in the infantile brains were abundant but smaller in size than the Lewy bodies observed in the Parkinson’s brain and the α-synuclein accumulations found in late-onset KD and <i>GALC</i> mutation carrier tissue. No significant α-synuclein accumulation was observed in the healthy diagnosed patient without GALC mutations (H). A secondary control experiment confirmed the specificity of the secondary antibody (I). Scale Bars: 100 μm.</p
Psychosine content and GALC activity in neuropsychiatric cohort.
<p>Psychosine content and GALC activity was measured in white (WM) and gray (GM) matter of the cortex in patients diagnosed with schizophrenia, bipolar disorder, depression, or as age-matched healthy controls. A,D) The same robust distribution of psychosine and GALC activity was observed in this cohort as found in the older neurodegenerative cohort. B,C,E,F) No significant changes in psychosine content or GALC activity were observed between any disease state. (One way ANOVA with Tukey’s multiple comparison test, *p<0.05. **p<0.01, ***p<0.001, ****p<0.0001).</p
GALC mutational effect on psychosine accumulation.
<p>Severe <i>GALC</i> mutations were identified in 2 patients diagnosed with Parkinson’s disease (PD). Psychosine levels in tissue from these two patients were elevated compared to that measured in tissue from PD patients without a severe <i>GALC</i> mutation.</p
Psychosine content and GALC activity in neurodegenerative cohort.
<p>Psychosine concentration in white (WM) and gray (GM) cortical matter, substantia nigra, and caudate was examined in patients diagnosed with Parkinson’s, Alzheimer’s, Krabbe, or healthy controls. A-D) Psychosine was found to have a robust distribution, elevated in the white matter and substantia nigra of all patients. E-H) Psychosine in white and gray matter of Parkinson’s brains trended upwards compared to AD and healthy controls but did not reach significance. GALC activity in white (WM) and gray (GM) cortical matter, substantia nigra, and caudate was examined in patients diagnosed with Parkinsons’s, Alzheimer’s, Krabbe’s, or healthy controls. I-L) GALC activity was found to have a robust distribution, with lower levels found in the white matter and substantia nigra of all patients. M-P) GALC activity in white matter of Parkinson’s brains trended downwards compared to AD and healthy controls but did not reach significance. Q) Total cortical psychosine (summation of white and gray matter of cortex) found higher levels (p = 0.0554) of psychosine in Parkinson’s tissue compared to healthy controls. R) A total cortical GALC activity (summation of white and gray matter of cortex) did not find significantly different levels of GALC activity in Parkinson’s tissue compared to healthy controls. S) Correlation of psychosine to GALC activity as measured within the total cortical tissue of each group. (panel A-P: one way ANOVA with Tukey’s multiple comparison test, *p<0.05. **p<0.01, ***p<0.001, ****p<0.0001, panel Q,R: t-test).</p
Psychosine content and GALC activity correlated with aging in mid-aged cohort.
<p>Psychosine content (A,B) and GALC activity (C,D) in cortical brain tissue from a combined cohort of mid-aged neuropsychiatric patients and healthy control patient tissue was compared to age at time of death. Linear regression revealed a significant positive correlation between psychosine content in the white matter (A) and age in this cohort, but a similar positive correlation did not reach significance in grey matter (B). However, a significant negative correlation between GALC activity and age was present in both white (C) and grey (D) matter. (Statistical test of slope significantly non-zero, *p<0.05).</p