Noureddine Melikechi

Prof. Noureddine Melikechi


Research Focus & Metrics

Academic Career Length

28Years (1999-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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23 October 2018 in Geophysical Research Letters
Verified
Journal Article
Open access
PDF file
JLJ. Lasue
J. Lasue
ACAgnes Cousin
Agnes Cousin
PMP.‐Y. Meslin
P.‐Y. Meslin
NMN. Mangold
N. Mangold
RWRoger C. WIENS
Roger C. WIENS
FCF. Cécile
F. Cécile
The ubiquitous eolian dust on Mars plays important roles in the current sedimentary and atmospheric processes of the planet. The ChemCam instrument retrieves a consistent eolian dust composition at the submillimeter scale from every first laser shot on Mars targets. Its composition presents significant differences with the Aeolis Palus soils and the Bagnold dunes as it contains lower CaO and higher SiO2. The dust FeO and TiO2 contents are also higher, probably associated with nanophase oxide components. The dust spectra show the presence of volatile elements (S and Cl), and the hydrogen content is similar to Bagnold sands but lower than Aeolis Palus soils. Consequently, the dust may be a contributor to the amorphous component of soils, but differences in composition indicate that the two materials are not equivalent.

1 September 2020 in Spectrochimica Acta Part B: Atomic Spectroscopy
Verified
Journal Article
Closed access
RGRosalba Gaudiuso
Rosalba Gaudiuso
EEEbo Ewusi-Annan
Ebo Ewusi-Annan
WXWeiming Xia
Weiming Xia
NMNoureddine Melikechi
Noureddine Melikechi

26 January 2024 in Talanta
Verified
Journal Article
Closed access
ASAli Safi
Ali Safi
JLJoshua E. Landis
Joshua E. Landis
HAHelmar G. Adler
Helmar G. Adler
HKHossein Khadem
Hossein Khadem
KEKEMAL EFE ESELLER
KEMAL EFE ESELLER
NMNoureddine Melikechi
Noureddine Melikechi

5 October 2020 in Applied Spectroscopy
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Journal Article
Closed access
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DSDavid Surmick
David Surmick
LTLeon Taleh
Leon Taleh
NMNoureddine Melikechi
Noureddine Melikechi
The impact of altering laser focusing conditions on laser-induced breakdown spectroscopy experiments is investigated under ambient Earth laboratory and simulated Martian atmospheres. Experiments were performed in which the focal spot size was varied on a sample by altering the lens to sample distance with respect to targets of interest. Samples investigated include aluminum, copper, and steel. Specific neutral and ionic transitions of each sample were monitored. Atomic and ionic emissions show different intensity peak distributions along the varying lens to sample distance. Ionic species have peak emissions when laser plasma is initiated with a focused spot within the sample in ambient Earth laboratory air, while atomic emissions have peak intensities several millimeters deeper into a sample. In simulated Martian atmospheres, atomic emissions are observed to peak when the laser is focused within the sample, while ionic emissions have peak intensities when the laser is focused near the surface of a sample.

22 November 1999 in Applied Physics Letters
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Journal Article
Open access
ZBZachary S. Benaich
Zachary S. Benaich
RPRanjit D. Pradhan
Ranjit D. Pradhan
SMShabbir M. Mian
Shabbir M. Mian
NMNoureddine Melikechi
Noureddine Melikechi

28 January 2025 in Heliyon
Verified
Journal Article
Open access
ASAli Safi
Ali Safi
EGElisa Giunti
Elisa Giunti
OMOmar Melikechi
Omar Melikechi
WXWeiming Xia
Weiming Xia
NMNoureddine Melikechi
Noureddine Melikechi
Early detection of Alzheimer's disease is essential for effective treatment and the development of therapies that modify disease progression. Developing sensitive and specific noninvasive diagnostic tools is crucial for improving clinical outcomes and advancing our understanding of this condition. Liquid biopsy techniques, especially those involving plasma biomarkers, provide a promising noninvasive method for early diagnosis and disease monitoring. In this study, we analyzed the plasma proteomic profiles of 38 healthy individuals, with an average age of 66.5 years, and 22 patients with Alzheimer's disease, with an average age of 79.7 years. Proteins in the plasma were quantified using specialized panels designed for proteomic extension assays. Through computational analysis using a linear support vector machine algorithm, we identified 82 differentially expressed proteins between the two groups. From these, we calculated 6642 possible protein ratios and identified specific combinations of these ratios as significant features for distinguishing between individuals with Alzheimer's disease and healthy individuals. Notably, the protein ratios kynureninase to macrophage scavenger receptor type 1, Neurocan to protogenin, and interleukin-5 receptor alpha to glial cell line-derived neurotrophic factor receptor alpha 1 achieving accuracy up to 98 % in differentiating between the two groups. This study underscores the potential of leveraging protein relationships, expressed as ratios, in advancing Alzheimer's disease diagnostics. Furthermore, our findings highlight the promise of liquid biopsy techniques as a noninvasive and accurate approach for early detection and monitoring of Alzheimer's disease using blood plasma.