An efficient method for estimating non-adiabatic coupling matrix elements (NACME) and rate constants for internal conversion (
k
IC
) is presented. The method, based on Plotnikov's theory, requires ...only calculations of the electronic wave functions and the corresponding electronic excitation energies. Computationally expensive calculations of the derivatives of the electronic wave function with respect to the nuclear coordinates are avoided. When the main accepting modes of the electronic excitation energy are X
-
H vibrations, the present method can be used for estimating the efficiency of the energy transfer between donor and acceptor molecules. It can also be used in studies of the influence of hydrogen bonding or solvent effect on fluorescence quenching, in studies of vibronic effects of TADF (thermally activated delayed fluorescence) emitters, and for calculating
k
IC
. Here,
k
IC
and NACME are calculated for free-base porhyrin, magnesium porphyrin, azulene, naphthalene, pyrene and fluorenone interacting with a solvent molecule. Reverse
k
IC
and NACME are further calculated for the T
1
→ T
2
transition of dibenzothiophene-
S
,
S
-dioxide (PTZ-DBTO2), which is used in TADF applications. Finally, we estimate the efficiency of the energy transfer between two large porphyrinoid dimers.
An efficient method for estimating non-adiabatic coupling matrix elements (NACME) and rate constants for internal conversion (
k
IC
) is presented.
A new method for calculating internal conversion rate constants (
k&cmb.b.line;
IC
), including anharmonic effects and using the Lagrangian multiplier technique, is proposed. The deuteration effect ...on
k&cmb.b.line;
IC
is investigated for naphthalene, anthracene, free-base porphyrin (
H
2
P
) and tetraphenylporphyrin (
H
2
TPP
). The results show that anharmonic effects are important when calculating
k&cmb.b.line;
IC
for transitions between electronic states that are energetically separated (Δ
E
) by more than 20 000-25 000 cm
−1
. Anharmonic effects are also important when Δ
E
< 20 000-25 000 cm
−1
and when the accepting modes are X-H stretching vibrations with a frequency larger than 2000 cm
−1
. The calculations show that there is mixing between the S
1
and S
2
states of naphthalene induced by non-adiabatic interactions. The non-adiabatic interaction matrix element between the S
1
and S
2
states is 250 cm
−1
and 50 cm
−1
for the normal and fully deuterated naphthalene structure and this difference significantly affects the estimated fluorescence quantum yield. Besides aromatic hydrocarbons
H
2
P
and
H
2
TPP
, the
k&cmb.b.line;
IC
rate constant is also calculated for pyrometene (PM567) and tetraoxa8circulene (4B) with a detailed analysis of the effect of the vibrational anharmonicity.
A new method for calculating internal conversion rate constants (
k
IC
), including anharmonic effects and using the Lagrangian multiplier technique, is proposed.
A novel method for calculating rate constants for internal conversion (
k
IC
) that simultaneously accounts for Duschinsky, anharmonic and Herzberg-Teller effects has been developed and implemented. ...This method has been applied to robust planar molecules like tetraoxa8circulene (
4B
), free-base porphyrin (
H
2
P
) and pyrometene (
PM567
) with small Duschinsky rotation (
i.e.
with almost identical normal coordinates in the ground and excited states) and to poly
n
fluorenes (
P
n
F
) (
n
= 2-14) with a substantial Duschinsky rotation. The obtained results show that the Duschinsky effect is large in the harmonic approximation, whereas it is in general much smaller in the anharmonic approximation. The Duschinsky effect is found to be large for high frequency vibrational modes with energies of ∼3300 cm
−1
such as the X-H (X = C, N and O) stretching modes that mix in the S
1
→ S
0
electronic transition. However, even in this case, the increase in
k
IC
due to the Duschinsky effect does not exceed one order of magnitude. The calculations show that anharmonic contributions to
k
IC
are larger than Herzberg-Teller contributions which in turn are larger than contributions from the Duschinsky effect ANH > HT > Du. We also show that an approximation, where only X-H bonds are considered in the
k
IC
calculation, is accurate even for
P
n
F
(
n
= 2-14).
A novel method for calculating rate constants for internal conversion (
k
IC
) that simultaneously accounts for Duschinsky, anharmonic and Herzberg-Teller effects has been developed and implemented.
A theoretical method for calculating rate constants for internal conversion (IC), intersystem crossing (ISC) and radiative (R) electronic transitions is presented. The employed method uses ...temperature-dependent quantum Green's functions, which give the opportunity to consider almost any nth-order polynomial perturbation operator and the influence of external electromagnetic fields on the rate constants. The rate constants of the IC, ISC and R processes are calculated for two important indocyanine molecules namely indocyanine green (
ICG)
and heptamethine cyanine (
IR808)
at the Franck-Condon level using the temperature-dependent quantum Green's function approach. Calculations at the time-dependent density functional theory level with the MN15 functional show that
ICG
and
IR808
have only one triplet state below the S
1
state. The main deactivation channel of the S
1
state is the IC process with a large (
k
IC
(S
1
→ S
0
)) rate constant of ∼10
9
-10
11
s
1
. The estimated quantum yield of fluorescence (
fl
) is 0.0010.24 for the two studied molecules, which agrees rather well with experimental values. Thus, the present approach enables calculations of the three kinds of rate constants and the quantum yield of fluorescence using the same computational methodology.
A theoretical method for calculating rate constants for internal conversion (IC), intersystem crossing (ISC) and radiative (R) electronic transitions is presented.
We have developed a new methodology for calculating contributions to the rate constants (
k
IC
) of internal conversion that are induced by external electric (
k
IC-E
) or magnetic (
k
IC-M
) fields. ...The influence of the external electric and magnetic fields on the
k
IC
was estimated for seven representative molecules. We show that the
k
IC-E
contribution calculated at a field strength of 10
11
V m
−1
is generally as large as the
k
IC
rate constant in the absence of the external field. For indocyanine green, azaoxa8circulene, and pyromitene 567, the
k
IC-E
contribution is as large as
k
IC
already at a field strength of 10
9
V m
−1
. Such electric-field strengths occur for example in plasmonic studies and in strong laser-field experiments. The induced effect on the
k
IC
rate constant should be accounted for in calculations of photophysical properties of molecules involved in such experiments. The induced effect of an external magnetic field on
k
IC
can be neglected in experiments on Earth because the magnetic contribution becomes significant only at very strong magnetic fields of 10
4
-10
5
T that cannot be achieved on Earth. However, the magnetic effect on the rate constant of internal conversion can be important in astrophysical studies, where extremely strong magnetic fields occur near neutron stars and white dwarfs.
We have developed a new methodology for calculating contributions to the rate constants (
k
IC
) of internal conversion that are induced by external electric (
k
IC-E
) or magnetic (
k
IC-M
) fields.
Display omitted
•A new method for calculating the internal conversion rate constant is proposed.•The approach has been applied to the study of molecules important for organic electronics.•The method ...facilitates the design of efficient molecular systems.
A new method for calculating the internal conversion rate constant, which takes into account all possible vibrational transitions between two adiabatic electronic states, is proposed. The simple analytical form of the correlation function obtained in the harmonic and anharmonic approximations and taking into account the Franck-Condon term makes it possible to perform fast calculations. In addition, the method takes into account temperature effects within harmonic kind, which extends its area of application to explain experimental processes. The approach has been applied to the study of molecules important for organic electronics, such as tetraoxa8circulene, free-base porphyrin and polynfluorenes. The method provides valuable information on IC processes and facilitates the design of efficient molecular systems.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Chronic obstructive pulmonary disease (COPD) is a multifactorial disease of the respiratory system which develops as a result of a complex interaction of genetic and environmental factors closely ...related to lifestyle. We aimed to assess the combined effect of the PI3K/AKT/mTOR signaling pathway (
PIK3R1, AKT1, MTOR, PTEN
) and sirtuin (
SIRT1, SIRT3, SIRT6
) genes to COPD risk. SNPs of
SIRT1
(rs3758391, rs3818292),
SIRT3
(rs3782116, rs536715),
SIRT6
(rs107251),
AKT1
(rs2494732),
PIK3R1
(rs10515070, rs831125, rs3730089), MTOR (rs2295080, rs2536),
PTEN
(rs701848, rs2735343) genes were genotyped by real-time polymerase chain reaction (PCR) among 1245 case and control samples. Logistic regression was used to detect the association of SNPs in different models. Linear regression analyses were performed to estimate the relationship between SNPs and lung function parameters and smoking pack-years. Significant associations with COPD were identified for
SIRT1
(rs3818292) (
P
= 0.001, OR = 1.51 for AG),
SIRT3
(rs3782116) (
P
= 0.0055, OR = 0.69) and SIRT3 (rs536715) (
P
= 0.00001, OR = 0.50) under the dominant model,
SIRT6
(rs107251) (
P
= 0.00001, OR = 0.55 for СT),
PIK3R1
: (rs10515070 (P = 0.0023, OR = 1.47 for AT), rs831125 (
P
= 0.00001, OR = 2.28 for AG), rs3730089 (
P
= 0.0007, OR = 1.73 for GG)),
PTEN
: (rs701848 (
P
= 0.0015, OR = 1.35 under the log-additive model), and rs2735343 (
P
= 0.0001, OR = 1.64 for GC)). A significant genotype-dependent variation of lung function parameters was observed for
SIRT1
(rs3818292),
SIRT3
(rs3782116),
PIK3R1
(rs3730089), and
MTOR
(rs2536). Gene-gene combinations that remained significantly associated with COPD were obtained; the highest risk of COPD was conferred by a combination of G allele of the
PIK3R1
(rs831125) gene and GG of
SIRT3
(rs536715) (OR = 3.45). The obtained results of polygenic analysis indicate the interaction of genes encoding sirtuins
SIRT3, SIRT2, SIRT6
and
PI3KR1, PTEN, MTOR
and confirm the functional relationship between sirtuins and the PI3K/AKT/mTOR signaling pathway.
Using the method of the density functional theory (DFT/B3LYP/6-31G(d,p)), the vibrational absorption and emission spectra of bifluorene and terfluorene molecules are calculated. A good agreement is ...obtained between the model and experimental spectra. The vibrational promoting modes forming a vibronic progression in the emission bands are determined.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Identification of a complex of genetic predictors of multiple sclerosis (MS) based on previously obtained results in genome-wide association studies of disease markers (GWAS markers) in a population ...of MS patients and healthy individuals of the Republic of Bashkortostan (Russian Federation) using polygenic detection.
The total study group consisted of 2048 people (641 patients with MS and 1407 healthy individuals) who permanently resided in the Republic of Bashkortostan and belonged to the Bashkir (
325), Russian (
772) or Tatar (
951) nationalities. The analysis of association between MS and polymorphisms previously associated with the disease according to GWAS data was performed. Of the 641 MS patients, 247 were the subject of a 20-year prospective clinical follow-up.
The
allele was most significantly associated with MS in Russians (OR=2.00,
5.85·10
) and Tatars (OR=2.38,
8.61·10
). An increased MS risk in Russians was also associated with the
(OR=1.56,
0.007) and
(OR=1.61,
0.003) alleles. Meta-analysis confirmed the association of the
and
alleles with MS in the total group, as well as revealed associations of the
and
alleles with the disease. Using polygenic analysis, we identified a complex predictor
with a pronounced protective effect against MS in the total group (OR=0.34, P
=2.65·10
).
We reproduced the association of eight polymorphisms (
and
) with MS, previously identified in GWAS in European populations. Whole exome or genome sequencing may help to reveal the mechanisms underlying the pathogenesis of MS in populations of the Russian Federation.
Objectives.
To carry out a replicative analysis of the associations with multiple sclerosis of genetic markers of autoimmune diseases identified as a result of genome-wide studies in ethnically ...homogeneous groups of Russians and Tatars living in the Republic of Bashkortostan.
Materials and methods.
A group of 1724 people (547 patients with multiple sclerosis, 1177 members of the control group) underwent genotyping using allele-specific PCR and PCT with restriction fragment length polymorphism analysis for polymorphic variants rs2069762 of the
IL2
gene, rs759648 of the
PVT1
gene, rs1800682 of the
FAS
gene, and rs12708716 of the
CLEC16A
gene. Associations of these genetic markers with multiple sclerosis were studied using the PLINK program by logistical regression using an additive genetic model with sex as a covariate.
Results.
In the Tatar group we found an association between the rs759648*C of
PVT1
with multiple sclerosis (OR = 1.42,
p
= 0.023). Meta-analysis of the results in the two ethnic groups confirmed the association of the rs759648*C allele of
PVT1
with the disease (a random effects model and a fixed effect model: OR = 1.29,
p
= 0.018).
Conclusions.
These data provide evidence of an association between the polymorphic variant rs759648 of
PT1
and multiple sclerosis in the Russian and Tatar populations living in the Republic of Bashkortostan. No associations with the other polymorphic variants studied were found in these two ethnic groups.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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