Langevin dynamics simulations for the critical adsorption of end-grafted active polymers.

The critical adsorption of end-grafted active polymer chains on an attractive surface is studied using Langevin dynamics simulations. The active polymers are composed of an active Langevin particle located at the head and a sequential passive chain. Results show that the active force exerted by the active head pulls the active polymer away from the surface. Consequently, the adsorption of the active polymer is hindered, and the critical surface attraction strength, , increases proportionally to the square of the active force, Fa2. The increase in depends on the rotation behavior of the active head. Specifically, for the restricted rotating active polymer (RRAP) chain with a longer rotational persistence time as the rotation of the active head is restricted, increases significantly with Fa. On the other hand, for the freely rotating active polymer (FRAP) chain with a shorter rotational persistence time as the rotation of the active head is free, shows a weak dependence on Fa. The results show that the active force has a significantly stronger pulling effect on the RRAP chain than on the FRAP chain. Furthermore, knotted conformations are observed for the adsorbed RRAP chain at large Fa. These knots reduce the adsorption of monomers near the grafted end. In contrast, no knotted conformations are observed for the FRAP chains due to the comparatively weaker pulling effect of the active force.

Adsorption of active polymers on attractive nanoparticles.

The adsorption of active polymers on an attractive nanoparticle (NP) is studied using Langevin dynamics simulations. The active polymers consist of an active Brownian particle (ABP) at the head and a subsequent passive polymer chain. The ABP experiences an active force of magnitude Fa. The interactions between the active polymer and NP are modeled as Lennard-Jones potential with a strength εpn. We find the critical adsorption point εpn* increases with increasing the active force Fa. The increment of εpn*, denoted as Δεpn*, due to Fa can be expressed approximately as Δεpn* ∝ Fa2.5 for the restricted rotating active polymer (RRAP) where the rotation of the head ABP is restricted and Δεpn* ∝ Fa1.7 for the freely rotating active polymer (FRAP) where the ABP rotates freely. Meanwhile, the conformation of the adsorbed polymer, such as adsorbed trains on NP and the tail near the ABP, are also dependent on Fa. When the tail near the ABP is short, the adsorption is significantly affected by the active force. However, when the tail is long, the whole polymer can be viewed as a long tail stretched by the active force and unperturbed adsorption monomers. Simulation results show that the active force has a direct and significant effect on εpn* and the structure of the adsorbed active polymers.

Translocation of two-dimensional active polymers through nanopores using Langevin dynamics simulations.

The translocation of polymers through nanopores is a complex process influenced by various factors. In this study, the translocation behavior of a two-dimensional active polymer chain, comprised of a head active Brownian particle (ABP) and a tail passive polymer chain, through a nanopore is studied using Langevin dynamics simulations. Results show that the effect of the self-propulsion force of the ABP on the translocation differs significantly from the driving force inside the pore for traditional polymer translocations. Specifically, the translocation time τ initially increases with increasing the magnitude fs of the self-propulsion force and then decreases with a further increase in fs. A small fs lowers the potential barrier for the translocation and thus promotes slow translocations, whereas a large fs directly pulls the polymer chain through the nanopore following the scaling relation τ ∝ fs-1. Moreover, two asymptotic scaling relations between τ and polymer length N, τ ∝ Nα, are found, with the exponent α of about 2.5 for small fs or long N and the exponent α of about 1.4 for short active polymers with large fs. We discover that the slow rotation of the ABP accelerates the translocation process.

Bronchial oncocytic carcinoma in an adult: a case report and literature review.

BACKGROUND: Lung salivary-type tumors originating from bronchial submucosal glands are rare, only four types of salivary gland-type tumors are listed in 2015 WHO classification of lung tumors. Here, we report a rare case of oncocytic carcinoma (OC) in the right main bronchus. CASE PRESENTATION: A 34-year-old man presented to our hospital with a two-month history of recurrent hemoptysis and with one month of inspiratory dyspnea. Pulmonary function tests showed mild restrictive ventilatory dysfunction and severe diffusion dysfunction. Furthermore, the flow volume loop showed a variable extra-thoracic obstruction. Computed tomography (CT) of the chest revealed that a polypiform nodule of 13 mm in diameter was at the proximal right main bronchus. Testing for purified protein derivative was positive (category 2). The nodule was resected under bronchoscopy. The bronchial aspirate was negative for mycobacterium tuberculosis and tumor cells. The biopsy sample showed a solid and acinar predominant pattern with abundant eosinophilic cytoplasm. The bronchial mucosa was destroyed and replaced by tumor cells. The loose edematous stromal reaction could be seen in a local area. Immunohistochemically, tumor cells were positive for CK, EMA, Vimentin, CD117, CK7, S100, Mammaglobin and SOX10. Only scattered tumor cells were stained by basal cell markers, including CK5/6, P40 and P63. Electron microscopy revealed numerous swelling mitochondria with lacking mitochondrial cristae in tumor cells. Fluorescence in situ hybridization (FISH) testing for MAML2 and ETV6 rearrangement were negative. Next-generation sequencing analysis of 520 genes in the tissue biopsy specimen showed no somatic mutation. The diagnosis of OC was made. Subsequently, the patient underwent a right upper lobectomy with sleeve resection of the main bronchus and lymph dissection. No recurrent evidence was seen during two years of chest CT follow-up. CONCLUSIONS: To our knowledge, this is the first case of primary OC in the bronchus. This patient has no recurrence during two years of follow-up, indicating that primary OC in the bronchus has the same favorable prognosis as in salivary glands. Moreover, complete excision and thorough sampling to know the invasive growth pattern is important to reach the correct diagnosis.

Dynamics of a two-dimensional active polymer chain with a rotation-restricted active head.

The dynamics of a two-dimensional active polymer composed of an active Brownian particle (ABP) at the head and a passive polymer chain is investigated using Langevin dynamics simulation. The ABP experiences a self-propulsion force fs and a resistance torque M as the passive polymer chain is bonded to the edge of the ABP. M restricts the rotation of the ABP, and thus the dynamics of the ABP and that of the whole active polymer are influenced significantly. Due to this restriction, the persistence time τr, which characterizes the random rotation of the ABP, is increased significantly and changes non-monotonically with the rotational friction coefficient ηr. Our simulation results show that the effect of M on the dynamics of the active polymer can be characterized mainly by the change of τr. Moreover, the propulsive diffusion coefficient DP of the whole polymer chain originated from the self-propulsion force can be described by a scaling relation DP ∝ fs2τr/N2ηt2 with ηt the translational friction coefficient and N the polymer length. Our results show that the diffusion is promoted by the resistance torque M and τr is a key factor for the diffusion of active polymers.

Spirocyclohexadienone-Type Neolignans with Neuroprotective and Neurite Outgrowth Enhancing Activities from Magnolia liliiflora.

Three rare spirocyclohexadienone-type neolignans, magnoflorins A-C (1-3), and three known analogs (4-6), were isolated from the leaves of Magnolia liliiflora. Magnoflorin D (4) was obtained from natural resources for the first time. The chemical structures and absolute configurations of 1-4 were elucidated through detailed analysis of HR-ESI-MS, IR, 1 H, 13 C, and 2D NMR, and ECD experiments. The absolute configuration of 5 were characterized by X-ray crystallography in present study. Moreover, compounds 4 and 5 displayed moderate neuroprotective activity against corticosterone-induced PC12 cells injury at 20 µM with cell viability of 71.5±0.99 % and 73.0±1.42 %, respectively, compared to the model group with 60.83±0.93 %. Compound 6 could enhance neurite outgrowth of nerve growth factor (NGF)-induced PC12 cells at 10 µM with the differentiation rate of 11.98 %, compared with 20.49 % of 50 ng/ml NGF.

Correction to: PTH Derivative promotes wound healing via synergistic multicellular stimulating and exosomal activities.

An amendment to this paper has been published and can be accessed via the original article.

PTH Derivative promotes wound healing via synergistic multicellular stimulating and exosomal activities.

BACKGROUND: Diabetic wounds are a disturbing and rapidly growing clinical problem. A novel peptide, parathyroid hormone related peptide (PTHrP-2), is assumed as multifunctional factor in angiogenesis, fibrogenesis and re-epithelization. This study aims to test PTHrP-2 efficiency and mechanism in wound healing. METHODS: Through repair phenomenon in vivo some problems were detected, and further research on their mechanisms was made. In vivo therapeutic effects of PTHrP-2 were determined by HE, Masson, microfil and immunohistochemical staining. In vitro direct effects of PTHrP-2 were determined by proliferation, migration, Vascular Endothelial Grown Factor and collagen I secretion of cells and Akt/ Erk1/2 pathway change. In vitro indirect effects of PTHrP-2 was study via exosomes. Exosomes from PTHrP-2 untreated and treated HUVECs and HFF-1 cells were insolated and identified. Exosomes were co-cultured with original cells, HUVECs or HFF-1 cells, and epithelial cells. Proliferation and migration and pathway change were observed. PTHrP-2-HUVEC-Exos were added into in vivo wound to testify its hub role in PTHrP-2 indirect effects in wound healing. RESULTS: In vivo, PTHrP-2 exerted multifunctional pro-angiogenesis, pro-firbogenesis and re-epithelization effects. In vitro, PTHrP-2 promoted proliferation and migration of endothelial and fibroblast cells, but had no effect on epithelial cells. Therefore, we tested PTHrP-2 indirect effects via exosomes. PTHrP-2 intensified intercellular communication between endothelial cells and fibroblasts and initiated endothelial-epithelial intercellular communication. PTHrP-2-HUVEC-Exos played a hub role in PTHrP-2 indirect effects in wound healing. CONCLUSION: These findings of this study indicated that PTHrP-2, a multifunctional factor, could promote wound healing via synergistic multicellular stimulating and exosomal activities.

[Quantum State-Resolved Energy Redistribution of CO2 from Collisions with Highly Vibrationally Excited NaH].

Degenerate stimulated hyper-Raman pumping is used to excite high vibrational states of NaH. The full state-resolved distribution of scattered CO2(0000, J) molecules from collisions with excited NaH(ν″=14, J=21) was reported. The nascent number densities of NaH were determined from absorption measurements at times t=1 µs as the laser to prepare NaH(ν″, J″). Absorption signals were converted to NaH(ν″, J″) population using absorption coefficients and the transient Doppler-broadened linewidths. The nascent CO2(0000, J) population were obtained from transient overtone laser induced fluorescence line intensity measured at short times relative to the time between collisions. The scattered CO2(0000, J=2～80) molecules had a biexponential rotational distribution. Fitting the data with a two-component exponential model yielded CO2 product distributions with Trot=(650±80) and (1 531±150) K. The cooler distribution accounted for 79% of the scattered population and resulted from elastic or weakly inelastic collisions that induced very little rotational excitation in CO2. The hotter distribution involved large changes in CO2 rotational energy and accounted for 21% of collision. Nascent translational energy profiles for scattered CO2 (0000, J=60～80) were measured using high resolution transient overtone fluorescence. The relative translational energy of the scattered molecules increased as a function of final CO2 rotational state with 〈ΔErel〉=582 cm-1 for J=60, and 2 973 cm-1 for J=80. Energy transfer rates were determined for the full J-state distribution by monitoring the change of the nascent population. The total rate constant for appearance of scattered CO2(0000) was kapp=(7.2±1.8)×10(-10) cm(3)·mol(-1)·s(-1). The depletion for the low-J CO2 states was involved in the collisional energy transfer of the initial distribution. For J=2～38, the average rate constant for depletion of scattered CO2(0000) is 〈kdep〉=(6.9±1.7)×10(-10) cm(3)· mol(-1)·s(-1).

[Collisional relaxation between highly vibrationally excited Na2 and Ar and H2].

Energy transfer rate constants were measured for excited rovibrational levels of Na2 (X1Σ(g)+). Stimulated emission pumping was used to excited the levels v = 33-51, J = 11 via A-X transition. Laser induced fluorescence was used to follow the collision dynamics. Energy transfer processes induced by collisions with Ar and H2 were investigated. The decay curves for the parent level populations gave good fits to single exponential function. At v = 33-51, the total transfer rate constants increase linearly with vibrational quantum number. Parameterized expressions for the (48, 11)--to--(47, J) rate constants were fitted to the fractional populations of the satellite lines. This produced sets of relative rate constants. Absolute rate constants were then obtained by normalizing the sums of the relative rate constants to the total removal rate constants. For Na2 (v) + Ar, no multiquantum vibrational transfer was detected. For Na2 (v) + H2, a significant fraction of the initial population of highly vibrationally excited Na2 (X v = 48) relaxes to lower vibrational level (Δ v = -5). The time scale is much shorter than the known collisional lifetimes of the intervening vibrational levels and thus a sequential single-quantum relaxation mechanism can be explicitly ruled out. For v = 48, at least 40% of the initially prepared population, undergoes multiquantum vibrational relaxation. We discuss possible explanations of this result.

[Vibrational and rotational excitation of CO2 in the collisional quenching of H2(v = 1)].

Energy transfer in H2 (1,1) +CO2 collisions was investigated using high resolution transient laser spectroscopy. Rotational state selective excitation of v = 1 for rotational level J = 1 was achieved by stimulated Raman pumping. Energy gain into CO2 resulting from collisions with H2 (1,1) was probed using transient absorption techniques, Distributions of nascent CO2 rotational populations in both the ground (00 degrees 0) state and the vibrationally excited (00 degrees 1) state were determined from overtone absorption measurements. Translational energy distributions of the recoiling CO2 in individual rovibrational states were determined through measurement of Doppler-broadened transient line shapes. A kinetic model was developed to describe rates for appearance of CO2 states resulting from collisions with H2(1,1). From scanned CARS (coherent anti-stokes Raman scattering) the spectral peaks population ratio n0/n1 was obtained, where n0 and n1 represent the number densities of H2 at the levels (0,1) and (1,1), respectively. Using rotational Boltzmann distribution of H2 (v = 0) at 300 K, n1 was yielded. Values for rate coefficients were obtained using data for CO2 (00 degrees 0) J = 48 to 76 and CO2 (00 degrees 1) J = 5 to 33. The rate coefficients derived from appearance of the (00 degrees 0) state have values of K(tr) = (3.9 ± 0.8) x 10(-11) cm3 x molecule(-1) x s(-1) for J = 48 and k(tr) = (1.4 ± 0.3) x 10(-10) cm3 x molecule(-1) x s(-1) for J = 76, with a monotonic increase for the higher J states. For the (00 degrees 1) state, values of k(tr) remain fairly constant at k(tr) = (4.3 ± 0.9) x 10(-12) cm3 x molecule(-1) x s(-1). Rotational populations for the nascent CO2 states were measured at 0. 5 µs following excitation of H2. The transient population for each state was fit using a Boltzmann rotational distribution. The CO2 (00 degrees 0) J = 48-76 rotational states were populated substantially relative to the initial 300 K CO2 distributions, and the distribution is described by Trot. The excited (00 degrees 1) state has T(rot), 310 K. The center-of-mass translational temperatures for the (00 degrees 0) state are all much greater than 300 K, with T(rel) = 1 532 K for J = 76. In contrast, transient line profiles for the J = 5 - 33 levels of excited (00 degrees 1) state do not show any broadening above the initial 300 K distributions, indicating that excitation to the (00 degrees 1) state is not accompanied by translational energy change.

[Time resolved distribution of excitation energy in collisions of vibrationally excited KH with CO2].

The vibrational levels of KH(X1 sigma+ v" = 0-3) were generated in the reaction of K(5P) with H2. The vibrationally excited KH(v" = 17) was populated by an overtone pump-probe configuration Different characteristics of collisional energy transfer in highly and lowly excited vibrational levels of KH and CO2 were investigated through measuring the time-resolved distribution of vibrational energy in KH(v" = 17.3) + CO2 collisions. For KH(v" = 17), there existed three principal regions of vibration temperature (T(v)) in this equilibration process. The initial phase consists of very rapid fall in T(v) within - 5 micros, and the vibrational energy of KH(v" = 17) is mainly transferred to the vibrational levels of CO2 (00 degrees 1) or high rotational levels of CO2 (00 degrees 0). The second phase (5-20 micros) has a slight decline in T(v), and the process of energy transfer to vibrational levels or high rotational levels of CO2 has already finished. The vibration temperature of the third phase has a slightly more rapid decline compared with the last phase. This phase shows that the process of transfer to lowly rotational levels and translation energy of CO2 is accelerated. The equilibration of vibrationally excited KH (v" = 3) in CO2 was also investigated. There are similarities to the behavior of KH (v" = 17) in CO2 plot, but also are significant differences. Once the initial resonant V-R exchange has equalized vibrational temperatures, there is a very slow linear decline in T(v) with equilibrium attained within -80 micros. This same point is reached within 15 micros for KH (v" = 17). The data demonstrate that single rate coefficient measurements are unlikely to capture the complex nature of processes that generally are multistaged with different relaxation rates characterizing each different stage. Examination of the quantum state distributions reveals that these distinct stages reflect the dominance of specific energy transfer mechanisms, some of which are inherently fast and others are much slower. The energy gain into CO2 resulting from collisions with excited KH was probed using transient absorption techniques. Distributions of nascent CO2 rotational populations in both ground (00 degrees 0) state and the vibrationally excited (00 degrees 1) state were determined. A kinetic model was developed to describe rate coefficients for appearance of CO2 states resulting from collisions with excited KH. These experiments show that collisions resulting in CO2 (00 degrees 0) are accompanied by substantial excitation in rotation while the vibrationally excited CO2 (00 degrees 1) state has rotational energy distributions near the initial distributions.

[Transfer energy disposal in collisions of NaK (6(1)sigma+) with H2].

The radiative lifetimes and rate coefficients for deactivation of high lying 6(1)sigma+ state of NaK by collisions with H2 were studied. An OPO laser was set to a particular 2(1)sigma+ <-- 1(1)sigma+ transition. Another single mode Ti sapphire laser was then used to excite molecule from 2(1)sigma+ level to the 6(1)sigma+ state. The predissociation was monitored by the atomic potassium emission at the 3D --> 4P (1.7 microm) or the S --> 4P (1.24 microm), while bound state radiative processes were monitored by total fluorescence from the upper state to the various levels, all studied as a function of H2 density. The values for predissociation, collisional dissociation and collisional depopulation rate coefficients were obtained. The decay signal of the time resolved fluorescence from the 6(1)sigma+ --> 2(1)sigma+, 6(1)sigma+ -->1(1)sigma+ or 2(1)sigma+ --> 1(1)sigma+ transition was monitored. Based on the Stern-Volmer equation, the radiative lifetimes were monitored for 6(1)sigma+ --> 2(1)sigma+ and 2(1)sigma+ --> 1(1)sigma+ transition. The rate coefficients for deactivation of collisions with H2 were monitored for 6(1)sigma+ --> 2(1)sigma+, 6(1)sigma+ --> 1(1)sigma+ and 2(1)sigma+ -->1(1)sigma+. When the density of H2 was 10(19) cm(-3), the total collisional transfer energy (15 426 cm(-1)) and radiative energy (10 215 cm(-1)) were obtained. The relative fraction ((f(v)), (f(R)), (f(T)) of average energy disposal was derived as (0.58, 0.03, 0.39); (f(v)), (f(R)), (f(T)) represent separately the relative fraction of average energy disposal among vibration, rotation and translation. The major vibrational and translational energy release supports the assumption that the 6(1)sigma(+) -H2 collision occurs primarily in a collisional energy transfer mechanism. In this experiment, alkali molecules relative energy population ratio was determined through using the time integrated intensity, so we can get the total transfer energy. That the NaK (6(1)sigma+) energy transfers to the H2 vibrational, rotational and translational energy was quantitatively given for the first time, which illustrates the collisional mechanism.

Contrasting PRRSV temporal lineage patterns at the individual farm, production system, and regional levels in Ohio and neighboring states from 2017 to 2021.

Porcine reproductive and respiratory virus (PRRSV), one of the most significant viruses in the swine industry, has been challenging to control due to its high mutation and recombination rates and complexity. This retrospective study aimed to describe and compare the distribution of PRRSV lineages obtained at the individual farm, production system, and regional levels. PRRSV-2 (type 2) sequences (n = 482) identified between 2017 - 2021 were provided by a regional state laboratory (Ohio Department of Agriculture, Animal Disease Diagnostic Center (ODA-ADDL)) collected from swine farms in Ohio and neighboring states, including Indiana, Michigan, Pennsylvania, and West Virginia. Additional sequences (n = 138) were provided by one collaborating swine production system. The MUSCLE algorithm on Geneious Prime® was used to align the ORF5 region of PRRSV-2 sequences along with PRRSV live attenuated vaccine strains (n = 6) and lineage anchors (n = 169). Sequenced PRRSV-2 were assigned to the most identical lineage anchors/vaccine strains. Among all sequences (n = 620), 29.8% (185/620) were ≥ 98.0% identity with the vaccine strains, where 93.5% (173/185) and 6.5% (12/185) were identical with the L5 Ingelvac PRRS® MLV and L8 Fostera® PRRS vaccine strains, respectively, and excluded from the analysis. At the regional level across five years, the top five most identified lineages included L1A, L5, L1H, L1C, and L8. Among non-vaccine sequences with production system known, L1A sequences were mostly identified (64.3% - 100.0%) in five systems, followed by L1H (0.0% - 28.6%), L1C (0.0% - 10.5%), L5 (0.0% - 14.4%), L8 (0.0% - 1.3%), and L1F (0.0% - 0.5%). Furthermore, among non-vaccine sequences with the premise identification available (n = 262), the majority of sequences from five individual farms were either classified into L1A or L5. L1A and L5 sequences coexisted in three farms, while samples submitted by one farm contained L1A, L1H, and L5 sequences. Additionally, the lineage classification results of non-vaccine sequences were associated with their restriction fragment length polymorphism (RFLP) patterns (Fisher's exact test, p < 0.05). Overall, our results show that individual farm and production system-level PRRSV-2 lineage patterns do not necessarily correspond to regional-level patterns, highlighting the influence of individual farms and systems in shaping PRRSV occurrence within those levels, and highlighting the crucial goal of within-farm and system monitoring and early detection for accurate knowledge on PRRSV-2 lineage occurrence and emergence.

[Effects of different annealing conditions on the photoluminescence of nanoporous alumina film].

The nanoporous alumina films were prepared by two-step anodic oxidation in 0.5 mol L-1 oxalic acid electrolyte at 40 V. Photoluminescence (PL) of nanoporous alumina films was investigated under different annealing atmosphere and different temperature. The authors got three results about the PL measurements. In the same annealing atmosphere, when the annealling temperature T< or =600 degreeC, the intensity of the PL peak increases with elevated annealing temperature and reaches a maximum value at 500 degreeC, but the intensity decreases with a further increase in the annealing temperature, and the PL peak intensity of samples increases with the increase in the annealing temperature when the annealling temperature T> or =800 degreeC. In the different annealling atmosphere, the change in the photoluminescence peak position for nanoporous alumina films with the increase in the annealing temperature is different: With the increase in the annealling temperature, the PL peak position for the samples annealed in air atmosphere is blue shifted, while the PL peak position for the samples annealed in vacuum atmosphere will not change. The PL spectra of nanoporous alumina films annealed at 1100 degreeC in air atmosphere can be de-convoluted by three Gaussian components at an excitation wavelength of 350 nm, with bands centered at 387, 410 and 439 nm, respectively. These results suggest that there might be three luminescence centers for the PL of annealed alumina films. At the same annealling temperature, the PL peak intensity of samples annealed in air atmosphere is stronger than that annealed in the vacuum. Based on the experimental results and the X-ray dispersive energy spectrum (EDS) combined with infrared reflect spectra, the luminescence mechanisms of nanoporous alumina films are discussed. There are three luminescence centers in the annealed nanoporous alumina films, which originate from the F center, F+ center and the center associated with the oxalic impurities. The effects of different annealing conditions on the photoluminescence of nanoporous alumina film are reasonably explained.

In Situ Absorption Characterization Guided Slot-Die-Coated High-Performance Large-Area Flexible Organic Solar Cells and Modules.

Slot-die coating is recognized as the most compatible method for the roll-to-roll (R2R) processing of large-area flexible organic solar cells (OSCs). However, the photovoltaic performance of large-area flexible OSC lags significantly behind that of traditional spin-coating devices. In this work, two acceptors, Qx-1 and Qx-2, show quite different film-formation kinetics in the slot-die coating process. In situ absorption spectroscopy indicates that the excessive crystallinity of Qx-2 provides early phase separation and early aggregation, resulting in oversized crystal domains. Consequently, the PM6:Qx-1-based 1 cm2 flexible device exhibits an excellent power conversion efficiency (PCE) of 13.70%, which is the best performance among the slot-die-coated flexible devices; in contrast, the PM6:Qx-2 blend shows a pretty poor efficiency, which is lower than 1%. Moreover, the 30 cm2 modules based on PM6:Qx-1, containing six 5 cm2 sub-cells, exhibit a PCE of 12.20%. After being stored in a glove box for over 6000 h, the PCE remains at 103% of its initial values, indicating excellent shelf stability. Therefore, these results show a promising future strategy for the upscaling fabrication of flexible large-area OSCs.

[Rovibrational state distributions of H2 in collisional energy transfer between NaK (6(1)sigma(+)) and H2].

The electronic to rovibrational energy transfer between the high-lying 6(1)sigma(+) state of NaK and H2 was investigated. The 6(1)sigma(+) state was excited using the optical-optical double resonance technique. Radiative processes were monitored by fluorescence from the 6(1)sigma(+) state to the ground 1(1)sigma(+) state. The CARS (coherent anti-Stokes Raman scattering) spectral technique was used to probe the internal state distribution of collisionally-populated H2 molecules. The scanned CARS spectra reveal that during E-V, R energy transfer processes H2 molecules are produced at v = 1, 2 and 3 levels. The semilog plot of the time-resolved H2 (3, 1) CARS intensity was obtained at a pressure of 4 x 10(4) Pa of H2. The slop yields an effective quenching rate of 8.09 x 10(5) s(-1). Analogically, for (3, 2), (3, 3) and (3, 5) levels, the quenching rates are 6.11 x 10(5), 4.32 x 10(5) and 2.45 x 10(5) s(-1), respectively. For (3, 1), (3, 2), (3, 3) and (3, 5) levels, the population ratios were obtained from scanned CARS spectral peaks. For (1, 1), (2, 1), (2, 2) and (2,3) levels, from scanned CARS spectral peaks two possible population ratios were yielded. Through shape simulations of time resolved CARS profiles under a kinetic model the actual population ratios were determined. The n2/n1, n3/n1, n4/n1, n5/n1, n6/n1, n7/n1 and n8/n1 are 0.51, 0.97, 0.45, 0.18, 0.10, 0.26 and 0.31, where n1, n2, n3, n4, n5, n6, n7 and n8 represent the number densities of H2 at (3, 1), (2, 1), (1, 1), (3, 3), (2, 3), (2, 2), (3, 2) and (3, 5) levels, respectively. The H2 molecules produced by energy transfer process were populated by 26% at the v = 1 level, 21% at v = 2 and 53% at v = 3. The major vibrational energy [(9.0 +/- 2.7) x 10(3) cm(-1)] release and the minor rotational energy [(3.9 +/- 1.1) x 10(2) cm(-1)] release are shown. Based on the Stern-Volmer equation, the radiative lifetime is (5.0 +/- 1.3) ns for the 6(1)sigma(+) state, the total rate coefficient for deactivation of 6(1)sigma(+) state by means of collisions with H2 is (2.1 +/- 0.4) x 10(-10) cm3 x s(-1). From actual population ratios the rate coefficients (in units of 10(-11) cm3 x s(-1)) for 6(1) sigma(+) -(1, 1), (2, 1), (2, 2), (2, 3), (3, 1), (3, 2), (3, 3) and (3, 5) are 5.4 +/- 1.6, 2.8 +/- 0.8, 0.6 +/- 0.2, 1.0 +/- 0.3, 5.6 +/- 1.7, 1.4 +/- 0.4, 2.5 +/- 0.8 and 1.7 +/- 0.5, respectively.

[Vibrational to rotational energy transfer between CsH (Chi1 Sigma+, nu > or = 15) and CO2].

The quenching of highly vibrational excited CsH through collisions with a 500 K bath of CO2 was investigated using the laser spectroscopy technique. CsH was formed by the Cs(7P)+H2 reaction. The pulse laser prepared CsH in the highly vibrational levels. Laser induced fluorescence was used to detect collisionally relaxed CsH. The relaxation rate coefficient of CsH (nu" = 21) with CO2 is 10 times larger than that of CsH(nu" = 15). Relaxation of CsH(nu") with H2 was also investigated. The mass effect on the collisional relaxation rate coefficients is strong. The observed collisional relaxation rate coefficients of H2 are bigger than those of CO2. Energy gain into CO2 resulting from collisions with excited CsH was probed using laser overtone spectroscopy technique. Distributions of nascent CO2 rotational population in the ground (00(0)0) state were determined. For CsH excited at nu" = 15, the scattered CO2 molecules have a rotational temperature of T(rot) = (605 +/- 50) K. For excitation at nu" = 21, the CO2 rotational temperature is T(rot) = (780 +/- 70) K. Based on the rotational temperatures, the average change in the CO2 rotational energy has a stronger dependence on the CsH initial energy. Using the ambient cell temperature, nu = 21 -2. 7 nu" = 15 was found. The nascent distributions of recoil velocities for collisions were determined from stimulated absorption line profiles of individual CO2 rotational states. For nu" = 15, scattered CO2 molecules with J = 36-48 have center of mass translational energy of = 600-972 cm(-1). For nu" = 21, the values increase to = 972-1 351 cm(-1). Based on propensity rules for collisions that favor small changes in energy and angular momentum, it is reasonable that low-J CO2 states will have lower translational energy than the high-J states. Extrapolating nu" = 15 and 21 data to the initial relative translational energy of E0 = 520 cm(-1) gives an estimate of the threshold states J(th) = 34 and 24, respectively. The onset of large is likely to occur at J states that are larger than J(th).

[Vibration-vibration energy transfer between highly vibrational excited RbH and H2, N2].

Rb-H2 mixture was irradiated with pulses of 696.4 nm radiation from a OPO laser, populating 6D state by two-photon absorption. The vibrational levels of RbH(X1sigma+,v" = 0-2) generated in the reaction of Rb(6D) with H2. Vibrational-state-specific total-removal relaxation rate coefficients, k(v) (M), for RbH(X1sigma+, v" = 15-22) by M = H2 and N2 were investigated in a pump and probe configuration. By the overtone pumping with a cw diode laser, highly vibrational states v" = 15-22 of RbH in its ground electronic state were obtained. Another diode laser was used to probe the prepared vibrational state. The decay signal of laser induced time-resolved fluorescence from A 1sigma+ (v') --> X1sigma+ (v") transition was monitored. Based on the Stern-Volmer equation, the total relaxation rate coefficient k(v) (H2) were yielded. A plot of k(v) (H2 + N2) vs alpha (mole fraction H2) yields a line with a slope of k(v) (H2)-k(v) (N2) and an intercept of k(v) (N2). The values of k(v) (H2) obtained from the slope of the fitted lines compare well with determined values of the k(v) (H2) from the Sern-Volmer plots. At v" < 18, the rate coefficients k(v) (M) increases linearly with vibrational quantum number. This linear region is dominated by single quantum relaxation (deltav = 1) collisional propensity rules. The region (v" > or = 18) where the dependence is much stronger than linear shows significant contribution from multiquantum (deltav > or = 2) relaxation or resonant vibration-vibration energy transfer between highly vibrationally excited RbH and H2 or N2. For RbH(v") + N2 (0), we measured the time-profile of v" = 16 after preparation of v" = 21. A clear bimodal distribution was observed. The first peak is due to resonant vibration-vibration energy transfer: RbH (v" = 21) + N2 (0) --> RbH (v" = 16) + N2 (1). The much broader second peak, at longer time delays, is due to sequential single-quantum relaxation. Although the second process results in a distribution that is much more spread out in time, the peak height is in the same order of magnitude, indicating that the two processes are at least comparable in probability.

[Vibrational energy transfer from vibrational levels of RbH(X 1sigma+, v = 0-2) to H2].

The vibrational energy transfer from vibrational levels of RbH(X 1sigma+, v = 0-2) by collision with H2 was determined using the integrated time-resolved laser induced fluorescence (LIF) in a five-arm crossed heat-pipe oven. Rb-H2 mixture was irradiated with pulses of 696.4 nm radiation from a OPO laser, populating 6D state by two-photon absorption. The vibrational levels of RbH(X 1sigma+) generated in the reaction of Rb(6D) and H2 were detected by LIF technique. The nascent quantum state distributions of RbH were obtained when the delay time between the pump and probe laser was 20 ns. The nascent RbH product molecules were found to populate the lowest three vibrational (v = 0, 1, 2) levels of the ground electronic state but could not be detected in any higher vibrational state. The integrated time-resolved LIF excited A 1sigma+ --> X 1sigma+ system in the presence of H2 was recorded with delay time from 0 to 10 micros. The RbH signal of v = 0, 1 levels first increased and then decreased on a larger time scale. RbH was created instantaneously then was quenched by collision and diffused. The rate equations for the population of the vibrational levels were given. The integrated profiles method permitted us to determine the rate coefficients for vibrational transfer of RbH(X 1sigma+, v = 0-2) by collision with H2. The rate coefficients for collisional transfer of RbH(X 1sigma+) by collisions with H2 are (in units of 10-(11) cm3 x s(-1)) 3.4 +/- 0.8 and 2.8 +/- 0.6 for v = 2 --> v = 1 and v = 1 --> v = 0 respectively. The diffusion rates of v = 0, 1, 2 are (in units of 10(5) s(-1)) 4.9 +/- 1.1, 1.0 +/- 0.3 and 0.6 +/- 10.2, respectively. The experiment showed that vibrational relaxation from RbH(X 1sigma+, v = 0-2) was more efficient compared to that of other vibrational levels studied here.