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.

Theoretical Investigation on Electronic Excited States of the HSO Radical.

HSO radicals play an important role in the photochemical processes in combustion, the atmosphere, and the interstellar medium. In this work, we perform a high-level ab initio study on the electronic excited states of HSO using the internally contracted multireference configuration interaction methods including Davidson correction (icMRCI + Q) in combination with the correlation-consistent basis sets. The molecular geometries, vertical transition energies, oscillator strengths, and electronic configurations of 19 electronic states of HSO are computed. The electronic potential energy curves of HSO along the bond lengths and bond angles are presented. Based on our calculations, the interactions between the electronic states involved in the ultraviolet region and the mechanism of photodissociation are discussed, which will lay a foundation for revealing the dissociation dynamics of gas-phase HSO molecules in outer space and the earth's atmosphere.

Ab initio calculations of the spectra and lifetimes of the lead dimer.

Owing to the key role of the lead dimer (Pb2) as a heavy element benchmark for the Group IV-A dimers the assignment of its spectroscopic properties and chemical bonding is an important undertaking. To meet this demand, the present work provides comprehensive and detailed information on electronic structure and properties comprising a wide set of Pb2 states. Calculations are performed by a high-level ab initio approach. Firstly, the potential energy curves (PECs) of 19 Λ-S states as well as those of 24 ungerade Ω states are calculated by utilizing the multi-reference configuration interaction plus Davidson correction (MRCI + Q) method taking into account core-valence correlation (CV) and spin-orbit coupling (SOC) effect, where Ω is a quantum number of the total (Λ + S) angular momentum projection. Secondly, interactions between the bound F3Σ-u, 23Σ+u states and repulsive 15Πu state induced by strong SOC are discussed based on the PECs analysis and calculated SOC matrix, which also indicates that the F3Σ-u state is predissociative. Thirdly, based on the calculated electric dipole transition moments and energy gaps between the 0+u(III), F0+u(II), C0+u(I) and X0+g states, the intense absorption bands of Pb2 due to these transitions are interpreted. Our results indicate that the trends in intensity of absorption spectra (F0+u(II), C0+u(I) ← X0+g) in the range of 12 600-13 600 and 22 200-23 800 cm-1 are consistent with the previously observed spectra of Pb2 in the qualitatively similar regions (15 200-16 200 and 19 800-21 800 cm-1). Finally, the calculated intensity of the weak magnetic-dipole transitions from the singlet excited b1Σ+g and a1Δg states to the triplet ground X3Σ-g state and their electric quadrupole components are presented for the Pb2 molecule in terms of SOC perturbations for the calculated Ω states expressed in Λ-S state notation. Based on our theoretical assignment, we predict that the weak emission a1Δg2 → X3Σ-g1 bands could be observed experimentally. The present work provides comprehensive electronic structure information and sheds new light on the absorption and emission spectra of the Pb2 dimer.

MRCI Study of the Electronic Structure and Transition Properties of a Tin Dimer.

The ground and excited states of Sn2 are calculated using the multireference configuration interaction method combined with Davidson correction (MRCI+Q). The influence of the spin-orbit coupling (SOC) effect on the electronic structure is also considered by the state interaction method of Breit-Pauli Hamiltonian. In the calculations, the potential energy curves and spectroscopic constants of 23 Λ-S states and 31 Ω states of Sn2 are obtained. The prominent spectral features in the visible region, new constants, and potential energy curves are discussed. The intensity of weak magnetic and quadrupole transitions in the near IR spectra is also calculated. From a computational point of view, we predict that the weak v'(0-2)-v″(0-5) bands of the magnetic b1Σg,0++-X3Σg,1(Ms=±1)- transition may be detected experimentally; the sub-bands (0, 0), (1, 0), and (2, 0) of the a1Δg,2-X3Σg,1(Ms=±1)- transition also may be observed in experiments since they are not overlapped by the strong electric dipole transition in the same IR region. According to the SOC matrix elements and contributions of the 15Πu0+, 15Πu1 (|Σ| = 0), and 15Πu1 (|Σ| = 2) states to the predissociation line width of the 13Σu- -X3Σg1- transition, the broading and other predissociation features of the 13Σu- state are analyzed. From our calculations, it follows that the strong coupling between the bound 13Σu- state and the repulsive 15Πu state causes the predissociation of the 13Σu- state at the vibrational levels v' ≥ 8. In addition, our results suggest that the previously observed bands of Sn2 in the visible range of 19000-20000 cm-1 should be reassigned into the mixing transitions among the X3Σg,1--23Σu,0-+ and X3Σg,0+--23Σu,1+ manifold. The results are expected to provide new comprehensive information for better understanding the spectra and dynamics of the electronic excited states of the Sn2 molecule.

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 of the spectroscopy and radiative transition probabilities of Si2 from visible to infrared.

High level ab initio calculations on the electronic states of a silicon dimer (Si2) have been carried out by employing a multi-reference configuration interaction plus Davidson correction (MRCI + Q) approach with the aug-cc-pVQZ basis set. The scalar relativistic correction is taken into consideration by the second-order Douglas-Kroll-Hess approximation. In the present work, the transition properties (oscillator strength, Einstein spontaneous emission coefficient and radiative lifetime) of the singlet-singlet, triplet-triplet, and quintet-quintet transitions of Si2 are discussed. We emphasize the triplet-triplet emission bands H3Σ-u-X3Σ-g, K3Σ-u-X3Σ-g and D3Πu-L3Πg which are dominant for 0-11 (18 822 cm-1), 0-0 (30 672 cm-1), and 0-0 (28 881 cm-1) transitions, respectively. In addition, the strong experimentally observed b1Πu-d1Σ+g band around 4184 cm-1 corresponds to the second 1Σ+g-b1Πu combination in the infrared region. The calculated oscillator strengths of the singlet-singlet transitions (f1Πg-e1Σ-u, 21Πg-b1Πu, b1Πu-d1Σ+g and g1Δu-a1Δg) are in the order of 10-3. From a theoretical point of view, the 0-0 sub-band for the f1Πg-e1Σ-u transition, 0-7 for 21Πg-b1Πu, 0-0 for b1Πu-d1Σ+g and the 0-7 vibronic bands for the g1Δu-a1Δg transition may be observed experimentally. It is expected that the present results could provide theoretical support for a deeper understanding of the experimental Si2 spectra providing further applications in astrophysics.

Analysis of postoperative pregnancy outcome in 180 women with congenital uterine malformation.

Introduction: This study aims to explore the effects of combination of laparoscopy and hysteroscopy in pregnancy outcome in women diagnosed with congenital uterine malformation (CUM). The observation criteria include pregnancy rate, misdiagnosis rate, rate of spontaneous abortion and preterm birth rate. Material and methods: A total of 180 patients with congenital uterine malformation, who were treated in our hospital from January 2015 to June 2018, were enrolled in the study. Prior to hospitalization, all the patients had neither a history of genital tract surgery nor endocrine abnormalities, chromosomal abnormalities, immune abnormalities or other factors affecting pregnancy. Furthermore, the ovarian functions were normal, and there were no factors leading to infertility in the male partners. The diagnosis was mainly based on medical history, clinical manifestations, gynecological examinations, and ultrasonography including two-dimensional and three-dimensional ultrasonography, as well as hysterosalpingogram (HSG), magnetic resonance imaging (MRI), hysteroscopy, and/or laparoscopy or surgery. Patients were diagnosed and classified according to the Buttram classification. Results: Among these 180 patients, 37 patients were diagnosed with complete septate uterus, 96 patients had sub-septate uterus, 25 patients had unicornuate uterus, 11 patients were diagnosed with bicornuate uterus, and 11 patients had didelphic uterus. The total number of preoperative pregnancies was 112, including 106 spontaneous abortions, with an abortion rate of 94.64%, and 86 total postoperative pregnancies, among which spontaneous abortions occurred 11 times, with an abortion rate of 12.79%. The difference was statistically significant (p < 0.05). Conclusions: Uterine malformation surgery can significantly improve the reproductive prognosis in patients with CUM.

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.

The mitochondria-targeting antioxidant MitoQ alleviated lipopolysaccharide/ d-galactosamine-induced acute liver injury in mice.

The mitochondria are the primary source of reactive oxygen species (ROS) under pathological condition, but the significance of mitochondrial ROS in the development of Lipopolysaccharide (LPS)/D-galactosamine (D-Gal)-induced acute liver injury remains unclear. In the present study, the level of mitochondrial ROS in LPS/D-Gal has been determined by MitoSox staining and the potential roles of mitochondrial ROS in LPS/D-Gal-induced liver injury have been investigated by using the mitochondria-targeting antioxidant MitoQ. The results indicated that LPS/D-Gal exposure induced the generation of mitochondrial ROS while treatment with MitoQ reduced the level of mitochondrial ROS. Treatment with MitoQ ameliorated LPS/D-Gal-induced histopathologic abnormalities, suppressed the elevation of AST and ALT, and increased the survival rate of the experimental animals. Treatment with MitoQ also suppressed LPS/D-Gal-induced production of tumor necrosis factor α (TNF-α), inhibited the activities of caspase-3, caspase-8 and caspase-9, decreased the level of cleaved caspase-3 and reduced the counts of TUNEL positive cells. These results indicate that mitochondrial ROS is involved in the development of LPS-induced acute liver injury and the mitochondria-targeting antioxidant MitoQ might have potential value for the treatment of inflammation-based acute liver injury.

Large-scale comparative epigenomics reveals hierarchical regulation of non-CG methylation in Arabidopsis.

Genome-wide characterization by next-generation sequencing has greatly improved our understanding of the landscape of epigenetic modifications. Since 2008, whole-genome bisulfite sequencing (WGBS) has become the gold standard for DNA methylation analysis, and a tremendous amount of WGBS data has been generated by the research community. However, the systematic comparison of DNA methylation profiles to identify regulatory mechanisms has yet to be fully explored. Here we reprocessed the raw data of over 500 publicly available Arabidopsis WGBS libraries from various mutant backgrounds, tissue types, and stress treatments and also filtered them based on sequencing depth and efficiency of bisulfite conversion. This enabled us to identify high-confidence differentially methylated regions (hcDMRs) by comparing each test library to over 50 high-quality wild-type controls. We developed statistical and quantitative measurements to analyze the overlapping of DMRs and to cluster libraries based on their effect on DNA methylation. In addition to confirming existing relationships, we revealed unanticipated connections between well-known genes. For instance, MET1 and CMT3 were found to be required for the maintenance of asymmetric CHH methylation at nonoverlapping regions of CMT2 targeted heterochromatin. Our comparative methylome approach has established a framework for extracting biological insights via large-scale comparison of methylomes and can also be adopted for other genomics datasets.

An integrated label-free cell-based biosensor for simultaneously monitoring of cellular physiology multiparameter in vitro.

The study presented a novel integrated cell-based biosensor with light-addressable potentiometric sensor (LAPS) and electrical cell-substrate impedance sensor (ECIS). The integrated cell-based biosensor was fabricated in order to monitor the cellular metabolism and growth status by LAPS and ECIS. Moreover, the specific instrument was established for controlling the detection processes. Sensor test and cell experiments were carried out to determine the performance of integrated sensor. The result showed that integrated biosensor can monitor the change of cell electrical impedance and extracellular acidification simultaneously which can be used for drug evaluation by monitoring cell growth status (e.g. cell number, adhesion, and morphology) and cell energy metabolism status (e.g. extracellular acidification) in real time. With the development of sensor technology, the integrated cell-based biosensor will be a utility platform to study the mechanism of cellular metabolism and in vitro drug analysis.

Covalently immobilized biomolecule gradient on hydrogel surface using a gradient generating microfluidic device for a quantitative mesenchymal stem cell study.

Precisely controlling the spatial distribution of biomolecules on biomaterial surface is important for directing cellular activities in the controlled cell microenvironment. This paper describes a polydimethylsiloxane (PDMS) gradient-generating microfluidic device to immobilize the gradient of cellular adhesive Arg-Gly-Asp (RGD) peptide on poly (ethylene glycol) (PEG) hydrogel. Hydrogels are formed by exposing the mixture of PEG diacrylate (PEGDA), acryloyl-PEG-RGD, and photo-initiator with ultraviolet light. The microfluidic chip was simulated by a fluid dynamic model for the biomolecule diffusion process and gradient generation. PEG hydrogel covalently immobilized with RGD peptide gradient was fabricated in this microfluidic device by photo-polymerization. Bone marrow derived rat mesenchymal stem cells (MSCs) were then cultured on the surface of RGD gradient PEG hydrogel. Cell adhesion of rat MSCs on PEG hydrogel with various RGD gradients were then qualitatively and quantitatively analyzed by immunostaining method. MSCs cultured on PEG hydrogel surface with RGD gradient showed a grated fashion for cell adhesion and spreading that was proportional to RGD concentration. It was also found that 0.107-0.143 mM was the critical RGD concentration range for MSCs maximum adhesion on PEG hydrogel.

An olfactory bulb slice-based biosensor for multi-site extracellular recording of neural networks.

Multi-site recording is the important component for studies of the neural networks. In order to investigate the electrophysiological properties of the olfactory bulb neural networks, we developed a novel slice-based biosensor for synchronous measurement with multi-sites. In the present study, the horizontal olfactory bulb slices with legible layered structures were prepared as the sensing element to construct a tissue-based biosensor with the microelectrode array. This olfactory bulb slice-based biosensor was used to simultaneously record the extracellular potentials from multi-positions. Spike detection and cross-correlation analysis were applied to evaluate the electrophysiological activities. The spontaneous potentials as well as the induced responses by glutamic acid took on different electrophysiological characteristics and firing patterns at the different sites of the olfactory bulb slice. This slice-based biosensor can realize multi-site synchronous monitoring and is advantageous for searching after the firing patterns and synaptic connections in the olfactory bulb neural networks. It is also helpful for further probing into olfactory information encoding of the olfactory neural networks.

Evaluation of doxorubicin toxicity on cardiomyocytes using a dual functional extracellular biochip.

Nowadays, cardiotoxicity induced by clinical drugs presents a high prevalence and has aroused great attention onto the effective and reliable drug evaluation before clinical treatment. Doxorubicin (Adriamycin), as a type of anthracycline chemotherapy agent for cancer treatment, was restricted in the clinical use because of its cardiotoxicity. In the present work, a dual functional biochip ExCell integrated with microelectrode arrays and interdigitated electrodes was designed to study the electrophysiological function and physical state of cardiomyocytes under the treatment of doxorubicin. Extracellular field potentials and cell-substrate impedance were measured to respectively express these two functions simultaneously in the same culture. The result detected by ExCell presented a portrait of cardiotoxicity induced by doxorubicin. The amplitude of extracellular field potentials decreased to 93%, 82% and 50% at 50 min treatment of doxorubicin with concentrations of 20 µM, 100 µM and 200 µM, respectively. Successively, beating rate decrease, beat-to-beat variation and Ca(2+) flux manifested severe abnormality. The cell-substrate impedance declined continuously in the depressing process of electrophysiological function and cell death was induced in high concentration treatment. All these result indicate that the biochip ExCell has the potential to be a fast-response and subtle tool for high-throughput drug evaluation assays.

Extracellular potentials recording in intact olfactory epithelium by microelectrode array for a bioelectronic nose.

Human beings and animals have sensitive olfactory systems that can sense and identify a variety of odors. The purpose of this study is to combine biological cells with micro-chips to establish a novel bioelectronic nose system for odor detection by electrophysiological sensing measurements of olfactory tissue. In our experiments, 36-channel microelectrode arrays (MEAs) with the diameter of 30 microm were fabricated on the glass substrate, and olfactory epithelium was stripped from rats and fixed on the surface of MEA. Electrophysiological activities of olfactory receptor neurons in intact epithelium were measured through the multi-channel recording system. The extracellular potentials of cell networks could be effectively analyzed by correlation analysis between different channels. After being stimulated by odorants, such as acetic acid and butanedione, the olfactory cells generate different firing modes. These firing characteristics can be derived by time-domain and frequency-domain analysis, and they were different from spontaneous potentials. The investigation of olfactory epithelium can provide more information of olfactory system for artificial olfaction biomimetic design.

Impedance studies of bio-behavior and chemosensitivity of cancer cells by micro-electrode arrays.

Impedimetric analysis on adherently growing cells by micro-electrodes provides information related to cell number, cell adhesion and cellular morphology. In this study, cell-based biosensor with micro-electrode arrays (MEAs) was used to monitor the culture behavior of mammalian cancer cells and evaluate the chemosensitivity of anti-cancer drugs using electrochemical impedance spectroscopy. The platinum electrode arrays were fabricated by semiconductor technology to a 10 x 10 pattern, with diameter of 80 microm of each electrode. The human oesophageal cancer cell lines (KYSE 30) were cultured on the surface of the electrodes with the pre-coated fibronectin, the connecting protein for tumor cells metastasis and adhesion in extracellular matrix. Morphology changes during cells adhesion, spreading, and proliferation can be detected by impedimetric analysis in a real time and non-invasive way. Cisplatin was added to cells for potential drug screening applications. The experimental results show that this well-known anti-cancer drug has characteristic chemosensitivity effects on KYSE 30 cells which can be detected by MEA. Thus, this cell-based chip provides a useful analytical method for cancer research.

A novel design of multifunctional integrated cell-based biosensors for simultaneously detecting cell acidification and extracellular potential.

The paper discussed a novel design of multifunctional cell-based biosensors for simultaneously detecting cell acidification and extracellular potential. Employing living cells such as cardiac myocytes as a source for the light addressable potentiometric sensor (LAPS) array, this cell-based biosensor was able to monitor both the acidification and extracellular potential in parallel. For LAPS array fabrication, part of the silicon base was heavily doped with boron to form separate testing areas. Detecting system was built involving lock-in amplifier and digital demodulation with FFT methods. This LAPS array showed a good sensitivity of 53.9 mV/pH to H(+) with good linearity. Each testing area for extracellular potential detection was decreased to 200 microm x 200 microm in size to obtain a better sensitivity. Experiment results showed that this LAPS array could monitor the acidification of cells as well as the extracellular potential with good sensitivity. This novel integrated biosensor will be useful for multi-parameter extracellular monitoring and can possibly be a platform for drug screening.

AlGaN/GaN heterostructures for non-invasive cell electrophysiological measurements.

Recently, the ability to create bio-semiconductor hybrid devices has gained much interest for cell activity analysis. AlGaN material system has been demonstrated to be a promising cell-based biosensing platform due to a combination of unique properties, such as chemical inertness, optical transparency and low signal to noise ratios. To investigate the potential application of hybrid cell-AlGaN/GaN field effect transistor for cell electrophysiological monitoring, saos-2 human osteoblast-like cells were cultured in high density in non-metallized gate area of a transparent AlGaN/GaN heterostructure field effect transistor. We implemented and characterized the transistor recording of extracellular voltage in the cell-chip junction using the FET chip. The effect of ion channel blocker TEA on transistor signal was explored in order to test the capability of this hybrid chip for in vitro drug screening bioassay. Finally, the effect of cell adhesion on transistor signal was also studied by applying the protein kinase inhibitor H-7.

Detection of heavy metal toxicity using cardiac cell-based biosensor.

Biosensors incorporating mammalian cells have a distinct advantage of responding in a manner which offers insight into the physiological effect of an analyte. To investigate the potential applications of cell-based biosensors on heavy metal toxicity detection, a novel biosensor for monitoring electrophysiological activity was developed by light-addressable potentiometric sensor (LAPS). Extracellular field potentials of spontaneously beating cardiomyocytes could be recorded by LAPS in the range of 20 microV to nearly 40 microV with frequency of 0.5-3 Hz. After exposed to different heavy metal ions (Hg(2+), Pb(2+), Cd(2+), Fe(3+), Cu(2+), Zn(2+); in concentration of 10 microM), cardiomyocytes demonstrated characteristic changes in terms of beating frequency, amplitude and duration under the different toxic effects of ions in less than 15 min. This study suggests that, with the physiological monitoring, it is possible to use the cardiac cell-based biosensor to study acute and eventually chronic toxicities induced by heavy metal ions in a long-term and no-invasive way.