Metabolomics,
Journal Year:
2019,
Volume and Issue:
15(12)
Published: Nov. 15, 2019
Abstract
Introduction
Metabolomics
is
increasingly
being
used
in
the
clinical
setting
for
disease
diagnosis,
prognosis
and
risk
prediction.
Machine
learning
algorithms
are
particularly
important
construction
of
multivariate
metabolite
Historically,
partial
least
squares
(PLS)
regression
has
been
gold
standard
binary
classification.
Nonlinear
machine
methods
such
as
random
forests
(RF),
kernel
support
vector
machines
(SVM)
artificial
neural
networks
(ANN)
may
be
more
suited
to
modelling
possible
nonlinear
covariance,
thus
provide
better
predictive
models.
Objectives
We
hypothesise
that
classification
using
metabolomics
data,
non-linear
will
superior
generalised
ability
when
compared
linear
alternatives,
particular
with
current
PLS
discriminant
analysis.
Methods
general
performance
eight
archetypal
across
ten
publicly
available
data
sets.
The
were
implemented
Python
programming
language.
All
code
results
have
made
Jupyter
notebooks.
Results
There
was
only
marginal
improvement
SVM
ANN
over
all
RF
comparatively
poor.
use
out-of-bag
bootstrap
confidence
intervals
provided
a
measure
uncertainty
model
prediction
quality
observed
bigger
influence
on
than
choice.
Conclusion
size
set,
choice
metric,
had
greater
algorithm.
Nucleic Acids Research,
Journal Year:
2018,
Volume and Issue:
46(W1), P. W486 - W494
Published: April 13, 2018
We
present
a
new
update
to
MetaboAnalyst
(version
4.0)
for
comprehensive
metabolomic
data
analysis,
interpretation,
and
integration
with
other
omics
data.
Since
the
last
major
in
2015,
has
continued
evolve
based
on
user
feedback
technological
advancements
field.
For
this
year's
update,
four
key
features
have
been
added
4.0,
including:
(1)
real-time
R
command
tracking
display
coupled
release
of
companion
MetaboAnalystR
package;
(2)
MS
Peaks
Pathways
module
prediction
pathway
activity
from
untargeted
mass
spectral
using
mummichog
algorithm;
(3)
Biomarker
Meta-analysis
robust
biomarker
identification
through
combination
multiple
datasets
(4)
Network
Explorer
integrative
analysis
metabolomics,
metagenomics,
and/or
transcriptomics
The
interface
4.0
reengineered
provide
more
modern
look
feel,
as
well
give
space
flexibility
introduce
functions.
underlying
knowledgebases
(compound
libraries,
metabolite
sets,
metabolic
pathways)
also
updated
latest
Human
Metabolome
Database
(HMDB).
A
Docker
image
is
available
facilitate
download
local
installation
MetaboAnalyst.
freely
at
http://metaboanalyst.ca.
BMC Bioinformatics,
Journal Year:
2017,
Volume and Issue:
18(1)
Published: March 21, 2017
Non-targeted
metabolomics
based
on
mass
spectrometry
enables
high-throughput
profiling
of
the
metabolites
in
a
biological
sample.
The
large
amount
data
generated
from
requires
intensive
computational
processing
for
annotation
spectra
and
identification
metabolites.
Computational
analysis
tools
that
are
fully
integrated
with
multiple
functions
easily
operated
by
users
who
lack
extensive
knowledge
programing
needed
this
research
field.We
herein
developed
an
R
package,
metaX,
is
capable
end-to-end
through
set
interchangeable
modules.
Specifically,
metaX
provides
several
functions,
such
as
peak
picking
annotation,
quality
assessment,
missing
value
imputation,
normalization,
univariate
multivariate
statistics,
power
sample
size
estimation,
receiver
operating
characteristic
analysis,
biomarker
selection,
pathway
correlation
network
metabolite
identification.
In
addition,
offers
web-based
interface
(
http://metax.genomics.cn
)
assessment
normalization
method
evaluation,
it
generates
HTML-based
report
visualized
interface.
utilities
were
demonstrated
published
dataset
scale.
software
available
operation
either
graphical
user
(GUI)
or
form
command
line
functions.
package
example
reports
at
http://metax.genomics.cn/
.The
pipeline
platform-independent
easy
to
use
spectrometry.
Cell,
Journal Year:
2020,
Volume and Issue:
183(6), P. 1699 - 1713.e13
Published: Nov. 13, 2020
To
elucidate
the
role
of
Tau
isoforms
and
post-translational
modification
(PTM)
stoichiometry
in
Alzheimer's
disease
(AD),
we
generated
a
high-resolution
quantitative
proteomics
map
95
PTMs
on
multiple
isolated
from
postmortem
human
tissue
49
AD
42
control
subjects.
Although
PTM
maps
reveal
heterogeneity
across
subjects,
subset
display
high
occupancy
frequency
for
AD,
suggesting
importance
disease.
Unsupervised
analyses
indicate
that
occur
an
ordered
manner,
leading
to
aggregation.
The
processive
addition
minimal
set
associated
with
seeding
activity
was
further
defined
by
analysis
size-fractionated
Tau.
summarize,
features
protein
critical
intervention
at
different
stages
are
identified,
including
enrichment
0N
4R
isoforms,
underrepresentation
C
terminus,
increase
negative
charge
proline-rich
region
(PRR),
decrease
positive
microtubule
binding
domain
(MBD).
Scientific Reports,
Journal Year:
2018,
Volume and Issue:
8(1)
Published: Jan. 8, 2018
Missing
values
exist
widely
in
mass-spectrometry
(MS)
based
metabolomics
data.
Various
methods
have
been
applied
for
handling
missing
values,
but
the
selection
can
significantly
affect
following
data
analyses.
Typically,
there
are
three
types
of
not
at
random
(MNAR),
(MAR),
and
completely
(MCAR).
Our
study
comprehensively
compared
eight
imputation
(zero,
half
minimum
(HM),
mean,
median,
forest
(RF),
singular
value
decomposition
(SVD),
k-nearest
neighbors
(kNN),
quantile
regression
left-censored
(QRILC))
different
using
four
datasets.
Normalized
root
mean
squared
error
(NRMSE)
NRMSE-based
sum
ranks
(SOR)
were
to
evaluate
accuracy.
Principal
component
analysis
(PCA)/partial
least
squares
(PLS)-Procrustes
used
overall
sample
distribution.
Student's
t-test
followed
by
correlation
was
conducted
effects
on
univariate
statistics.
findings
demonstrated
that
RF
performed
best
MCAR/MAR
QRILC
favored
one
MNAR.
Finally,
we
proposed
a
comprehensive
strategy
developed
public-accessible
web-tool
application
(
https://metabolomics.cc.hawaii.edu/software/MetImp/
).
EBioMedicine,
Journal Year:
2020,
Volume and Issue:
63, P. 103154 - 103154
Published: Dec. 4, 2020
Early
diagnosis
of
coronavirus
disease
2019
(COVID-19)
is
the
utmost
importance
but
remains
challenging.
The
objective
current
study
was
to
characterize
exhaled
breath
from
mechanically
ventilated
adults
with
COVID-19.
In
this
prospective
observational
study,
we
used
real-time,
online,
proton
transfer
reaction
time-of-flight
mass
spectrometry
perform
a
metabolomic
analysis
expired
air
undergoing
invasive
mechanical
ventilation
in
intensive
care
unit
due
severe
COVID-19
or
non-COVID-19
acute
respiratory
distress
syndrome
(ARDS).
Between
March
25th
and
June
25th,
2020,
included
40
patients
ARDS,
whom
28
had
proven
multivariate
analysis,
identified
characteristic
breathprint
for
We
could
differentiate
between
ARDS
accuracy
93%
(sensitivity:
90%,
specificity:
94%,
area
under
receiver
operating
curve:
0·94-0·98,
after
cross-validation).
four
most
prominent
volatile
compounds
were
methylpent-2-enal,
2,4-octadiene
1-chloroheptane,
nonanal.
non-invasive
detection
nonanal
may
identify
funded
by
Agence
Nationale
de
la
Recherche
(SoftwAiR,
ANR-18-CE45-0017
RHU4
RECORDS,
Programme
d'Investissements
d'Avenir,
ANR-18-RHUS-0004),
Région
Île
France
(SESAME
2016),
Fondation
Foch.