Ab Initio Study on Electronic Excited States of Monochlorosilylene.

We perform a high-level ab initio study on 20 electronic states of monochlorosilylene (HSiCl) using an internally contracted multireference configuration interaction method including Davidson correction (icMRCI+Q). The spin-orbit coupling (SOC) effect is investigated, leading to splitting of the 20 spin-orbit-free states into 50 spin-orbit-coupled states. Vertical transition energies, oscillator strengths, and potential energy curves are presented with and without considering the SOC effect. Analysis indicates that the SOC effect plays an important role, especially for the high-lying excited states of HSiCl. The state interaction and the dynamics of the electronic states of HSiCl in the ultraviolet region are discussed based on our calculation results. Our study paves the way to understanding the behavior of electronic excited states of monochlorosilylene.

An ab initio study on the electronic excited states and photodissociation mechanism of bromocarbene molecule.

We used the internally contracted explicitly correlated multireference configuration interaction (icMRCI-F12) method combined with Davidson correction to conduct a high-precision ab initio study of CHBr. The spin-orbit coupling (SOC) is incorporated into the calculation. The 21 spin-free states split into 53 spin-coupled states of CHBr. The vertical transition energies and oscillator strengths are obtained of these states. The SOC effect on the equilibrium structures and the harmonic vibrational frequencies of the ground state X1A', the lowest triplet state a3A'' and the first excited singlet state A1A'' is investigated. The results reveal a significant effect of the SOC on the bond angle and the frequency of the bending mode of a3A''. The potential energy curves of electronic states of CHBr as functions of the H-C-Br bond angle, C-H bond length, and C-Br bond length, respectively, are also investigated. Based on the calculated results, the interactions between electronic states and photodissociation mechanism involved in CHBr in the ultraviolet region are explored. Our theoretical studies will shed light on the complicated interactions and dynamics of the electronic states of bromocarbenes.

Electronic excited states of monobromosilylene molecules including the spin-orbit-coupling.

We employ the internally contracted multireference configuration interaction (icMRCI-F12) with Davidson corrections to explore the electronic states of monobromosilylene molecules (HSiBr). A total of 20 states with energy up to 8.7 eV and the corresponding 50 states after taking the spin-orbit coupling (SOC) effects into account are investigated. The spectroscopic constants of the low-lying states, as well as oscillator strengths, vertical transition energies and potential energy curves (PECs) for all the 20 spin-free states and the 50 spin-orbit-coupled states of HSiBr are presented. The results indicate that the SOC effect significantly affects the dissociation pathways and the PECs of electronic excited states of HSiBr. Based on our calculation results, the interactions between the states and the dissociation of HSiBr in the UV region are discussed. Our study sheds some light on the complex interactions and dynamics of the electronic excited states of HSiBr, which would provide valuable information for future experimental investigations.

Theoretical Study on the Spectroscopic Properties and Photodissociation Mechanism of Dibromocarbene.

Detailed calculations on the electronic states of dibromocarbene (CBr2) herein are presented. First, the spectroscopic properties of the electronic states including geometry parameters, harmonic vibrational frequencies and transition energies of the lowest electronic states of the neutral radical were calculated in detail using the internally contracted multireference configuration interaction methods including Davidson correction (icMRCI+Q) with correlation consistent basis sets of aug-cc-pVXZ (X = T, Q, 5). Second, as CBr2 including two Br atoms, the Spin-Orbit Coupling (SOC) effect on the spectroscopic parameters and the one-dimensional cuts of the potential energy surface (PESs) of the lowest three states were studied. The barrier to linearity and dissociation of the singlet state were discussed. Third, the one-dimensional cuts along with the vertical transition energy (VTE), the oscillator strength, and so on of the electronic states related to the several lowest dissociation limits of CBr2 were calculated at the icMRCI+Q/aug-cc-pVTZ level. Based on the computed results of the electronic states of the radical, the photodissociation mechanism in the UV region were discussed in detail. The ab initio calculations are compared with the previous theoretical and experimental data and are in good agreement. The present work will provide a comprehensive understanding on the electronic structures and dissociation dynamics for the electronic states of the CBr2 radical.

Theoretical Study on the Structure and Dissociation Mechanism of Electronic Excited States of Nitrosyl Bromide Molecules.

High-level ab initio calculations have been presented on nitrosyl bromide, BrNO, which are performed by the internally contracted explicitly correlated multireference configuration interaction (icMRCI-F12) method with Davidson correction. A total of 17 electronic states of BrNO from the ground state to the excited states at energy below 7 eV have been investigated. The energies and transitions of the states have been obtained, along with potential energy curves along the Br-N-O angle and the N-Br and N-O bond lengths. The photodissociation mechanism of the excited state involved in the UV-vis energy region has been discussed based on our calculation results. Our study would be of value to understand the interaction and dynamics of the electronic excited states and thus the photochemical processes of the BrNO molecules.

Interaction and Photodissociation of Electronic Excited States of HS2 in the Ultraviolet Region: A Theoretical Contribution.

HS2 molecules play an important role in the photochemical processes in combustion, atmosphere, and interstellar medium, yet our knowledge about the electronic excited states in the UV region is limited. In this study, we perform high-level ab initio calculations on electronic states of HS2 using the internally contracted multireference configuration interaction method including the Davidson correction (icMRCI + Q) method. The vertical transition energies, oscillator strengths, electron configurations, and transitions of thirteen electronic states of HS2 with energy up to 8 eV are calculated at the icMRCI + Q/aug-cc-pv(5 + d)Z level. Based on the calculated potential energy curves, we investigate the interaction and photodissociation mechanism of the electronic states, which should shed some light on the decomposition processes of the gas-phase HS2 molecules in the ultraviolet region.

Exploring the structure and photodissociation mechanism of the electronic states of iodocarbene, CHI: a theoretical contribution.

We present herein a high-level ab initio study on the mono-iodine substituted carbene, CHI, using internally contracted multireference configuration interaction (icMRCI-F12) with Davidson correction which employs wave functions that explicitly depend on the electron-electron distance. The spin-orbit coupling (SOC) effect was included in our calculations. A total of 20 spin-free states with vertical transition energy up to 7.4 eV, as well as 50 spin-coupled states generated from the spin-free states via the SOC were studied. The results show significant influence of the SOC on the bond angles and the harmonic vibrational frequencies of the bending mode of the ground state (X1A') and the lowest triplet state (a3A''). Potential energy curves along the bond angle and the bond lengths of the electronic excited states of CHI were investigated. Based on our calculations, photodissociation dynamics in the ultraviolet region was disscussed for the first time, which would pave the way to further experimental investigations of CHI.

Configuration Interaction Study on the AlBr Molecule Including Spin-Orbit Coupling.

High-level ab initio calculations on the ground and the excited states of aluminum monobromide (AlBr) have been carried out by utilizing the internally contracted multireference configuration interaction method plus Davidson correction (icMRCI+Q) method. The core-valence correlation (CV) correction and spin-orbit coupling (SOC) effect have been investigated in the calculations. The potential energy curves (PECs) of the 13 Λ-S states, as well as those of the 24 Ω states generated from the Λ-S states under the SOC effect, have been obtained. The spectroscopic constants of the bound states have been determined, which are in accordance with the available experiment results. The SOC induced predissociation mechanisms of the a3Π and A1Π states have been analyzed with the aid of the spin-orbit matrix element. The transition properties of 0+(2)-X0+, 1(1)-X0+ and 1(2)-X0+ transitions are predicted, including the transition dipole moments (TDMs), Franck-Condon factors (FCFs), and the radiative lifetimes. Finally, the possibility of AlBr to be used for molecular laser cooling has been discussed based on our calculations.

Theoretical Study on the Excited Electronic States of CHCl: Application to Photodissociation at 193 nm.

We present herein a high-level ab initio study on the electronic excited states of CHCl using the internally contracted multireference configuration interaction method including Davidson correction (icMRCI+Q). A total of 13 electronic states with energy of up to 7 eV have been investigated. The vertical transition energies, oscillator strengths, electron configurations, and transitions of the electronic states of CHCl have been calculated at the icMRCI+Q/aug-cc-pv(5+d)Z level. The potential energy curves of the electronic states have been studied along the H-C-Cl angle, the C-H bond length, and the C-Cl bond length, respectively. Our theoretical study has provided comprehensive information for understanding the interaction and the behavior of the electronic excited states of CHCl. In particular, the excited state involved in the 193 nm photodissociation as well as the corresponding dissociation dynamics have been discussed on the basis of our calculation results. The present study should shed more light on the photochemistry of CHCl in the ultraviolet region.

Magnetization reversal of perpendicular magnetic anisotropy regulated by ferroelectric polarization in CoFe3N/BaTiO3 heterostructures: first-principles calculations.

Exploring the electric-field switching of perpendicular magnetic anisotropy (PMA) in multiferroic heterostructures has important physical significance, which attracts great interest due to its promising application for energy-efficient information storage. Herewith, we investigate the effect of ferroelectric polarization on magnetic anisotropy in CoFe3N/BaTiO3 heterostructures using first-principles calculations. The calculations reveal that the magnetic anisotropy of CoFe3N can be regulated by ferroelectric polarization of BaTiO3. When the ferroelectric polarization reverses, the PMA of FeCo-TiO2 and FeN-BaO configurations remains, but in the FeN-TiO2 and FeCo-BaO cases, magnetic anisotropy inverses between out-of-plane and in-plane direction. Further orbital-resolved analysis indicates that the transition of magnetic anisotropy is mainly attributed to the orbital hybridization of interfacial Fe/Co atoms with O atoms induced by the magnetoelectric effect. This study may open an effective approach toward modulating PMA and lays a foundation to the development of low energy consumption memory devices.

Sevoflurane Suppresses Colon Cancer Cell Malignancy by Regulating circ-PI4KA.

PURPOSE: To explore the effect of SEV on colon cancer cells through circ-PI4KA. METHODS: The RNA level of circular RNA_0062389, microRNA-331-3p and LIM and SH3 protein 1 was determined by quantitative real-time polymerase chain reaction. Protein expression was detected by Western blot. Cell proliferation was investigated by 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di-phenytetrazoliumromide, cell colony formation and 5-ethynyl-29-deoxyuridine assays. Cell apoptosis was demonstrated using Annexin V-fluorescein isothiocyanate/propidium iodide double staining assay. Cell migration and invasion were detected by transwell assay. The target relationship between miR-331-3p and circ-PI4KA or LASP1 was predicted by starBase v2.0 online database, and identified by a dual-luciferase reporter assay. The effects between SEV treatment and circ-PI4KA knockdown on tumor formation were presented by in vivo tumor formation assay. RESULTS: Circ-PI4KA and LASP1 expressions were dramatically upregulated, while miR-331-3p was downregulated in colon cancer tissues and cells, respectively. SEV exposure significantly decreased the expression of circ-PI4KA and LASP1, but increased miR-331-3p expression. SEV inhibited cell proliferation, migration and invasion, and induced cell apoptosis by regulating circ-PI4KA. Furthermore, circ-PI4KA interacted with miR-331-3p, and miR-331-3p interacted with LASP1. SEV inhibited tumor growth by controlling circ-PI4KA in vivo. CONCLUSION: Circ-PI4KA attenuated SEV-treated colon cancer cell malignancy by upregulating LASP1 through binding to miR-331-3p, which provided a new mechanism for studying surgery-mediated therapy of colon cancer.

Inhibition of SUMO2/3 antagonizes isoflurane-induced cancer-promoting effect in hepatocellular carcinoma Hep3B cells.

Surgery for patients with complicated liver cancer often results in a long exposure to anesthesia with an increase in side effects. Continued long-term exposure to isoflurane may promote liver cancer progression. Small ubiquitin-like modifier (SUMO) 2 and 3, also known as SUMO2/3, conjugates to substrate proteins when cells undergo acute stress. However, whether or not SUMO2/3 is involved in isoflurane-mediated liver cancer progression is unknown. In the present study, hepatocellular carcinoma (HCC) cells were exposed to 2% isoflurane for 12 h, followed by 36 h of drug withdrawal, and the formation of SUMO2/3 conjugates and cancer behavioral characteristics were studied. The results demonstrated that the formation of SUMO2/3 conjugates was significantly increased following HCC cells being exposed to isoflurane for 0.5 h, and continued to increase for 48 h, even after the drug had been withdrawn. Furthermore, isoflurane-exposed HCC cells exhibited increased proliferation and invasion activity during the subsequent observation period. SUMO specific protease 3 (SENP3), which inhibits the binding of SUMO2/3 to its target proteins, was overexpressed and it was discovered that isoflurane-induced SUMOylation was significantly inhibited, and accordingly, the proliferation and invasion abilities of HCC cells were decreased to a certain extent. These findings indicated that SUMO2/3 is involved in the progression of HCC cells, at least in the Hep3B cell line, induced by the anesthetic isoflurane, and that inhibition of SUMO2/3 may antagonize the response. These results provided a novel target for decreasing the adverse reactions occurring in patients with HCC during anesthesia, particularly those who are exposed to isoflurane for long periods of time.

Analgesic effect of perioperative ketamine for total hip arthroplasties and total knee arthroplasties: A PRISMA-compliant meta-analysis.

BACKGROUND: Total hip arthroplasties (THA) and total knee arthroplasties (TKA) are always associated with a frequent incidence of postoperative pain. Effective pain management after surgery is quite essential for surgeons and patients. The purpose of the present meta-analysis is to evaluate the analgesic effect of perioperative ketamine after THA and TKA. METHODS: Seven online databases, Embase, Cochrane Library, Pubmed, Web of Science, China National Knowledge Infrastructure (CNKI), China Biomedical Literature Database (CBM), and Wanfang Data were searched for the related randomized controlled trials (RCT) by August 15, 2019. The qualities of the included studies were assessed based on the Cochrane Handbook for Systematic Reviews of Interventions 5.0. The visual analog scale (VAS), morphine equivalent consumption, and the side effects were used to evaluate the postoperative analgesic effect of ketamine by meta-analysis, which was performed by Review Manager version 5.3 software. RESULTS: The VAS scores at 6 hours, 12 hours, 24 hours, and 48 hours after surgery were statistically lower in the ketamine group. The morphine equivalent consumptions in 24 hours and 48 hours after surgery were also significantly lower in the ketamine group. For the side effects, no statistical differences in odds ratio (OR) of sedation, dizziness, hallucination, sweating, pruritus, urinary retention, constipation, version trouble, nightmares, and delirium were observed between the ketamine group and the control group. But postoperative nausea and vomiting (PONV) showed lower OR in the ketamine group. CONCLUSION: The present meta-analysis demonstrated perioperative ketamine could be used as a safe and effective analgesic agent for THA and TKA.

[Effects of injuries pulmonary arterial endothelial cell induced by endotoxin on proliferation of pulmonary artery smooth muscle cells and interference effect of bone morphogenetic protein-2].

OBJECTIVE: To investigate the effects of injuries pulmonary arterial endothelial cell induced by endotoxin on proliferation of pulmonary artery smooth muscle cells and interference effect of bone morphogenetic protein-2, and at the same time explore its possible mechanism. METHODS: Upper liquid of normal PAEC incubated by DMEM for 24 h without serum (EC-CMI) or that of PAEC incubated by the same DMEM and same period after incubating with endotoxin at concentration of 1 microg/ml for 1 h (EM-CMII) were collected and preserved for PASMC incubating. Confluent monolayer PASMC of rats were incubated with EC-CMI (group I), EC-CMII (group II), EC-DMII + BMP-2 1 ng/ml (group III), EC-DMII + BMP-2 10 ng/ml (group IV) and EC-DMII + BMP-2 100 ng/ml (group V) for 24 h. The cultured cells were identified by phase-contrast microscope and immunofluorescent stain of SMC specific antigen. The proliferation of PASMC were evaluated by the BrdU assay. The cell cycle analysis including proliferation index (PI) and S-phase cell fraction (SPF) were performed by the flow cytometry. the DNA synthesis was detected by [methyl-(3)H]-thymidine incorporation; the expression of cyclinD1 mRNA was elucidated by RT-PCR technology; the analysis of phosphorylated Smad1 (pSmad1) and expression of cyclinD1 protein were detected by Western-blot experiment. RESULTS: Cells were confirmed as smooth muscle by their typical "hill-valley" morphological features displayed under phase-contrast microscope and by immunofluorescent staining of smooth muscle, Compared with group I, there were a significant increase in proliferation rate, S-phase cell fraction (SPF), DNA synthesis in group II. Compared with group II, there were no significant changes in group III about that data. But the groups with 10 or 100 ng/ml (group IV and group V) of BMP-2 significantly attenuated proliferation rate, S-phase cell fraction (SPF), DNA synthesis and expression of cyclinD1 mRNA and protein compared with EC-CM2 alone (group II, P < 0.01). Phosphorylated Smad1 increased in group IV and group V compared with group II, (P < 0.01). CONCLUSION: The BMP-2 could downregulate expression of cyclinD1 gene by smad signaling transconduction system, then depressed proliferation of PASMCs by EC-CM2 in vitro culture. And this effect is dependent in the concentration range of 1 - 100 ng/ml.

Configuration interaction study on the low-lying electronic states of strontium hydride cation including spin-orbit coupling.

Ab initio calculations on low-lying electronic states of strontium hydride cations, SrH+, have been performed using the internally contracted multi-reference configuration interaction (icMRCI) method with Davidson correction (+Q). Spin-orbit coupling (SOC) effect between the singlet and triplet states of SrH+ has been investigated for the first time. The potential energy curves (PECs) of a total of 12 Λ-S states, as well as the 23 Ω states generated from the Λ-S states after considering the SOC effect, have been calculated. The spectroscopic constants and transition properties, including the transition dipole moments, the Franck-Condon factors, and the radiative lifetimes, have been obtained based on the calculated PECs. It indicates that the SOC effect plays a non-negligible role in electronic states of SrH+. Our study should shed light on the structure and behavior of low-lying electronic states and should pave further experimental studies on the spectroscopy of strontium hydride cations.

[Effects of recombinant human morphogenetic protein-2 on pulmonary artery pressure in acute lung injury caused by endotoxin and mechanism thereof: experiment with rats].

OBJECTIVE: To investigate the effects of recombinant human morphogenetic protein-2 (rhBMP-2) on pulmonary artery pressure in acute lung injury (ALI) caused by endotoxin and mechanism thereof: METHODS: Sixty Wistar rats were randomly divided into 3 equal groups: control group (Group C), receiving intravenous drip of normal saline (NS) through the femoral vein for 1.5 h; lipopolysaccharide (LPS) control group (Group L), receiving intravenous drip of NS and then LPS; and rhBMP-2 group (Group L(T)), receiving intravenous drip of rhBMP-2 solution and LPS solution successively through the femoral vein,, and then injected with rhBMP-2 through a detaining catheter after 24 and 48 hours respectively. Seventy-two hours later the pulmonary artery pressure (P(pa)) was detected and then all the rats were killed with their left lung taken out. Four hours before the collection of lung tissues 5-bromodeoxyuridine (BrDU) was injected intraperitoneally. Pathological examination was conducted. TUNEL was used to examine the proliferation/apoptosis of the pulmonary artery smooth muscle cells (PASMC). The thickness of pulmonary artery media was measured by microphotography system. RT-PCR and Western blotting were used to detect the mRNA and protein expression of the K(V 1.5) gene. PASMCs were collected to undergo electric physiologic examination of the activity of voltage gated potassium channel (K(V)). RESULTS: The PPa of Group L was (25.1 +/- 3.5) mmHg, significantly higher than those of Groups C and L(T) [(14.9 +/- 1.9) and (15.3 +/- 1.2) mmHg respectively, both P < 0.01]. The mitotic index of Group L was 3.1% +/- 0.6%, significantly higher than those of Group C and LT (0.4% +/- 0.1% and 0.5% +/- 0.6% respectively, both P < 0.01). The thickness of the pulmonary artery media of Group L was 9.7% +/- 2.8%, significantly greater than those of Groups C and L(T) (5.0% +/- 1.5% and 5.2 +/- 1.7% respectively, both P < 0.01). When the reference voltage was + 70 mV, the current value of the PASMC of Group L was (0.61 +/- 0.03) nA, significantly lower than that of Group L(T) [(0.61 +/- 0.17) nA. P < 0.001], lowering by 74.6%. Western blotting showed that the protein expression and mRNA expression of K(V 1.5) of Group L were both significantly lower than those of Groups C and L(T) (both P < 0.01). CONCLUSION: rhBNP-2 inhibits the proliferation and promotes the apoptosis of the PASMC, thus preventing the pulmonary vascular remodeling and pulmonary artery hypertension with the probable mechanism of activation of the K(V) channel and upregulation of K(V 1.5) gene expression.

Lung nodule classification with multilevel patch-based context analysis.

In this paper, we propose a novel classification method for the four types of lung nodules, i.e., well-circumscribed, vascularized, juxta-pleural, and pleural-tail, in low dose computed tomography scans. The proposed method is based on contextual analysis by combining the lung nodule and surrounding anatomical structures, and has three main stages: an adaptive patch-based division is used to construct concentric multilevel partition; then, a new feature set is designed to incorporate intensity, texture, and gradient information for image patch feature description, and then a contextual latent semantic analysis-based classifier is designed to calculate the probabilistic estimations for the relevant images. Our proposed method was evaluated on a publicly available dataset and clearly demonstrated promising classification performance.

The effect of rhBMP-2 on pulmonary arterioles remodeling in endotoxin-induced acute lung injury in rats.

Endotoxin is known to cause acute lung injury (ALI). Here, we investigated the effects and mechanisms of recombinant human bone morphogenetic protein-2 (rhBMP-2) on pulmonary arteriole remodeling in endotoxin-induced ALI in rats. Sixty Wistar rats were randomly divided into 3 groups (n = 20). Control group was infused with normal saline. Lipopolysaccharides (LPS) alone group was infused with LPS. LPS plus rhBMP2 group was infused with rhBMP-2 and LPS. Lung tissue was harvested. The tunica media of the pulmonary arterioles was measured. The expression levels of survivin, p21, cyclin D1, and activated caspase-3 were examined. The proliferation and apoptosis of pulmonary artery smooth muscle cells were evaluated. The tunica media of pulmonary arterioles in LPS alone group was significantly thicker than both that in control and that in LPS plus rhBMP2 groups (P < 0.01). The multiplication rate in LPS alone group was also significantly higher than both that in control and that in LPS plus rhBMP2 groups (P < 0.01). The apoptotic rate in LPS alone group was lower than that in LPS plus rhBMP2 group (P < 0.01). Compared with the control and LPS plus rhBMP2 groups, the expression levels of mRNA and proteins of survivin and cyclin D1 were increased in LPS alone group (P < 0.01), while the expression levels of p21 and activated caspase-3 were decreased (P < 0.01). RhBMP-2 inhibits the remodeling of pulmonary arterioles in endotoxin-induced ALI, which is achieved by enhancing apoptosis and inhibiting proliferation of pulmonary artery smooth muscle cells.

Overlapping node discovery for improving classification of lung nodules.

Distinguishing malignant lung nodules from benign nodules is an important aspect of lung cancer diagnosis. In this paper, we propose an automatic method to classify lung nodules into four different types, i.e. well-circumscribed, juxta-vascular, juxta-pleural and pleural-tail. Additionally, since the morphology of lung nodules forms a continuum between the different types, our proposed method is superior to previous methods that classify single nodules into a single type. First, a weighted similarity network is constructed based on the SVM with probability estimates, turning the 128-length SIFT descriptor to a 4-length probability vector against the four types. Then, the classification of nodules while identifying those with overlapping types is made using the weighed Clique Percolation Method (CPMw). We evaluate the proposed method on low-dose CT images from ELCAP. Our results show that there is more overlap between well-circumscribed and juxta-vascular, and between juxta-pleural and pleural tail. Also, quantitative comparisons among various methods demonstrate highly effective nodule classification results by identifying the overlapping nodule types.