Assessment of a combined gas chromatography mass spectrometer sensor system for detecting biologically relevant volatile compounds

© 2017 IOP Publishing Ltd. There have been a number of studies in which metal oxide sensors (MOS) have replaced conventional analytical detectors in gas chromatography systems. However, despite the use of these instruments in a range of applications including breath research the sensor responses (i.e. resistance changes w.r.t. concentration of VCs) remain largely unreported. This paper addresses that issue by comparing the response of a metal oxide sensor directly with a mass spectrometer (MS), whereby both detectors are interfaced to the same GC column using an s-swafer. It was demonstrated that the sensitivity of an in-house fabricated ZnO/SnO2 thick film MOS was superior to a modern MS for the detection of a wide range of volatile compounds (VCs) of different functionalities and masses. Better techniques for detection and quantification of these VCs is valuable, as many of these compounds are commonly reported throughout the scientific literature. This is also the first published report of a combined GC-MS sensor system. These two different detector technologies when combined, should enhance discriminatory abilities to aid disease diagnoses using volatiles from e.g. breath, and bodily fluids. Twenty-nine chemical standards have been tested using solid phase micro-extraction; 25 of these compounds are found on human breath. In all but two instances the sensor exhibited the same or superior limit of detection compared to the MS. Twelve stool samples from healthy participants were analysed; the sensor detected, on average 1.6 peaks more per sample than the MS. Similarly, analysing the headspace of E. coli broth cultures the sensor detected 6.9 more peaks per sample versus the MS. This greater sensitivity is primarily a function of the superior limits of detection of the metal oxide sensor. This shows that systems based on the combination of chromatography systems with solid state sensors shows promise for a range of applications

Roles of Education and IQ in Cognitive Reserve in Parkinson's Disease-Mild Cognitive Impairment.

Background/aimsThe role of cognitive reserve in Parkinson's disease (PD)-mild cognitive impairment (MCI) is incompletely understood.MethodsThe relationships between PD-MCI, years of education, and estimated premorbid IQ were examined in 119 consecutive non-demented PD patients using logistic regression models.ResultsHigher education and IQ were associated with reduced odds of PD-MCI in univariate analysis. In multivariable analysis, a higher IQ was associated with a significantly decreased odds of PD-MCI, but education was not.ConclusionThe association of higher IQ and decreased odds of PD-MCI supports a role for cognitive reserve in PD, but further studies are needed to clarify the interaction of IQ and education and the impact of other contributors such as employment and hobbies

Loss of AP-2delta reduces retinal ganglion cell numbers and axonal projections to the superior colliculus

Background: AP-2 delta is the most divergent member of the Activating Protein-2 (TFAP2) family of transcription factors. AP-2 delta is restricted to specific regions of the CNS, including a subset of ganglion cells in the retina. Retinal ganglion cells (RGCs), the only output neurons of the retina, are responsible for transmitting the visual signal to the brain. Results: AP-2 delta knockout results in loss of Brn3c (Pou4f3) expression in AP-2 delta -positive RGCs. While AP-2 delta-/- mice have morphologically normal retinas at birth, there is a significant reduction in retinal ganglion cell numbers by P21, after eye opening. Chromatin immunoprecipitation indicates that Brn3c is a target of AP-2 delta in the retina. Using fluorochrome-conjugated cholera toxin subunit B to trace ganglion cell axons from the eye to the major visual pathways in the brain, we found 87 % and 32 % decreases in ipsilateral and contralateral projections, respectively, to the superior colliculus in AP-2 delta-/- mice. In agreement with anatomical data, visually evoked responses recorded from the brain confirmed that retinal outputs to the brain are compromised. Conclusions: AP-2 delta is important for the maintenance of ganglion cell numbers in the retina. Loss of AP-2 delta alters retinal axonal projections to visual centers of the brain, with ipsilaterial projections to the superior colliculus being the most dramatically affected. Our results have important implications for integration of the visual signal at the superior colliculus

Development of Best Practices for Right-of-Way Valuations and Negotiations in Transportation Projects

The valuations of properties and the negotiations with property owners are two major tasks in the right-of-way acquisition process for transportation projects. If improved, those tasks can increase the overall project delivery efficiency. The Texas Department of Transportation (TxDOT) funded a research project that aimed to recommend some best practices for successful valuations and negotiations in Texas. The authors reviewed the different strategies and procedures followed in TxDOT by conducting interviews and surveys with right-of-way personnel. Guidelines supported by recommended practices were identified for both valuation and negotiation and then reviewed and validated by experts. Lastly, implementation guides were developed

Increased expression of integrin-linked kinase is associated with shorter survival in non-small cell lung cancer

BACKGROUND: Integrin-linked kinase (ILK) promotes tumor growth and invasion. Increased ILK expression is correlated with progression of several tumor types, but the expression of ILK has not been investigated in patients with non-small cell lung cancers (NSCLCs). METHODS: We investigated ILK expression in patients with NSCLC by means of immunohistochemistry. RESULTS: ILK expression was significantly associated with tumor grade, T status, lymph node metastasis and stage. (p = 0.0169 for tumor grade; p = 0.0006 for T status; p = 0.0002 for lymph node metastasis; p < 0.0001 for stage). The 5-year survival rates for patients with strong and weak or no ILK expression levels were 20% and 59%, respectively: the difference was statistically significant (p < 0.0001). A multivariate analysis of survival revealed that ILK expression, T status, N status and vascular invasion were statistically significant prognostic factors (p = 0.0218 for ILK; p = 0.0046 for T status; p < 0.0001 for N status; p < 0.0001 for vascular invasion). CONCLUSIONS: Our study demonstrates that increased expression of ILK is a poor prognostic factor in patients with NSCLC

Misuse made plain: Evaluating concerns about neuroscience in national security

In this open peer commentary, we categorize the possible “neuroscience in national security” definitions of misuse of science and identify which, if any, are uniquely presented by advances in neuroscience. To define misuse, we first define what we would consider appropriate use: the application of reasonably safe and effective technology, based on valid and reliable scientific research, to serve a legitimate end. This definition presents distinct opportunities for assessing misuse: misuse is the application of invalid or unreliable science, or is the use of reliable scientific methods to serve illegitimate ends. Ultimately, we conclude that while national security is often a politicized issue, assessing the state of scientific progress should not be

P3‐473: Service need among individuals with mild cognitive impairment and Alzheimer’s disease

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152600/1/alzjjalz2008052044.pd