Solvation Structures and Dynamics of Small Molecules: Experimental and Computational Studies Using Carbonyl Vibrational Modes as Probe

Solutions are ubiquitous in both the global environment and the human body, and play a significant role in scientific research and industrial production. The structures and dynamics of solutions have been studied for centuries. However, conventional experimental methods, whose intrinsic measuring time is on the order of nanoseconds to microseconds, could not detect the fast dynamics taking place in the solution on the timescale of femto- and pico-second. In this dissertation, the ultrafast two-dimensional infrared (2DIR) spectroscopy was applied to characterize the structure and dynamics in three different types of solutions on the sub-picosecond timescale. Linear Fourier transform infrared spectroscopy (FTIR) and computational calculations were performed to confirm the interpretation of the microscopic framework. Firstly, the ion effect on water structural dynamic properties at high concentration was studied by looking into the solvation shell of acetate ion in D2O and in 6M NaCl solution. The FTIR lineshape of the carboxylate asymmetric mode and a dynamics component extracted from 2DIR is not affected by the highly concentrated salts, which is proved to be a particularity of the acetate ion by a comparative study on the azide ion. Ab initio molecular dynamics (AIMD) simulations confirmed the experimental observations and linked the observed vibrational phenomenon to the thermal rotation of acetate methyl group (—CH3). Secondly, ion solvation structure and dynamics in organic solvents were investigated. By AIMD and ab initio umbrella sampling (AIUS), the structure and dynamics of the lithium solvation shell in cyclic and in linear carbonates were compared. The intercalation of entire molecules into the first solvation shell of lithium is found in cyclic carbonate, which leads to a more rigid and more organized solvation structure in cyclic carbonate. Finally, a conductive neutral molecular mixture of acetic acid (HAc) and N- vi methylimidazole (C1Im) was characterized by both experimental and theoretical methods. The broadband peaks in FTIR was assigned as delocalized proton stretching mode in HAc-C1Im complexes. AIMD simulation, DFT calculation, and NMR measurements confirmed the existence of proton delocalization in the hydrogen bond between HAc and C1Im

On A Parabolic Equation in MEMS with An External Pressure

The parabolic problem $u_t-\Delta u=\frac{\lambda f(x)}{(1-u)^2}+P$ on a bounded domain $\Omega$ of $R^n$ with Dirichlet boundary condition models the microelectromechanical systems(MEMS) device with an external pressure term. In this paper, we classify the behavior of the solution to this equation. We first show that under certain initial conditions, there exists critical constants $P^*$ and $\lambda_P^*$ such that when $0\leq P\leq P^*$, $0<\lambda\leq \lambda_P^*$, there exists a global solution, while for $0\leq P\leq P^*,\lambda>\lambda_P^*$ or $P>P^*$, the solution quenches in finite time. The estimate of voltage $\lambda_P^*$, quenching time $T$ and pressure term $P^*$ are investigated. The quenching set $\Sigma$ is proved to be a compact subset of $\Omega$ with an additional condition, provided $\Omega\subset R^n$ is a convex bounded set. In particular, if $\Omega$ is radially symmetric, then the origin is the only quenching point. Furthermore, we not only derive the two-side bound estimate for the quenching solution, but also study the asymptotic behavior of the quenching solution in finite time.Comment: 35 pages, 1 figure. arXiv admin note: substantial text overlap with arXiv:1402.0066 by other author

Suppression of long non-coding RNA H19 inhibits proliferation, cell migration and invasion in human cervical cancer cells

Purpose: To determine the expression profile of lncRNA H19 in different cervical cancers, and to decipher its function in the growth and metastasis of cervical cancer.Methods: The analysis LncRNA H19 expression was performed using quantitative real timepolymerase chain reaction (qRT-PCR). Cell counting kit 8 (CCK8) assay was used to assess the viability of the cells. The cells were transfected with Si-H19 using Lipofectamine 2000 and the metastasis of cells was determined by cell migration and invasion assay. Immunoblotting was used to evaluate the protein expression.Results: The lncRNA H19 expression was considerably enhanced in cervical cancer cells, and was about 2.6 to 5.3 times more in cervical cancer cells relative to non-cancer cells. Inhibition of lncRNA caused significant reduction in cervical cancer cell growth in a time-dependent manner. In addition while silencing of lncRNA inhibited the metastasis of HeLa cells. Cell migration and invasion was about 26 % in Si-H19 transfected cervical cancer cells, relative to 65 % in Si-NC cervical HeLa cells. Similarly, cell invasion was 45 % in Si-H19 cervical HeLa cells relative to the negative control (Si-NC). Inhibition of HeLa cell metastasis was also concomitant with decline of metalloproteinases (MMP)-2 and 9expression.Conclusion: lncRNA regulates the growth and metastasis of cervical cancer cells. Thus, IncRNA may be an important therapeutic agent for cervical cancer.Keywords: Cervical cancer, lncRNA, Proliferation, Invasio

Symptoms of problematic pornography use among help-seeking male adolescents: Latent profile and network analysis

Background and aims: Little data exist on exploring the subgroups and characteristics of problematic pornography use (PPU) in help-seeking adolescents. The aims of the study were to classify the subgroups among help-seeking male adolescents, explore their similarities and differences, and uncover their core symptoms. Methods: A total of 3,468 Chinese male adolescents (Mage 5 16.64 years, SD 5 1.24) who were distressed about their pornography use were recruited. The Problematic Pornography Consumption Scale, the Brief Pornography Screen Scale, and Moral Disapproval of Pornography Use were used to classify them. The General Health Questionnaire, the Pornography Craving Questionnaire, and the Sexual Compulsivity Scale were used to investigate participants’ negative consequence related to their pornography use; and the Online Sexual Activity Questionnaire (OSAs) and time spent on pornography use every week were considered as quantitative indicators. Results: Help-seeking male adolescents could be divided into 3 profiles, namely, self-perceived problematic (SP, n 5 755), impaired control (IC, n 5 1,656), and problematic use groups (PPU, n 5 1,057). Frequency of OSAs was important for the identification of SP individuals, while negative consequences were more effective in identifying individuals with objective dysregulated behavior. Salience and mood modification were shared by all groups; however, in addition to this, the SP and PPU groups also showed withdrawal symptoms. Discussion and conclusion: This study’s results provide support for the presence of different profiles of help-seeking individuals and information on potential intervention targets among adolescents which is lacking in the literature

Insights into the metabolic profiling of Polygonati Rhizoma fermented by Lactiplantibacillus plantarum under aerobic and anaerobic conditions using a UHPLC-QE-MS/MS system

IntroductionPolygonati Rhizoma is a multi-purpose food with medicinal uses. Fermentation of Polygonati Rhizoma by lactic acid bacteria could provide new insights into the development of Polygonati Rhizoma products.MethodsIn this study, Lactiplantibacillus plantarum was fermented with Polygonati Rhizoma extracts in a bioreactor under aerobic and anaerobic conditions with pH and DO real-time detection. Metabolic profiling was determined by UHPLC-QE-MS/MS system. Principal component analysis and orthogonal partial least-squares discriminant analysis were used to perform multivariate analysis.ResultsA total of 98 differential metabolites were identified in broth after fermentation, and 36 were identified between fermentation under aerobic and anaerobic conditions. The main metabolic pathways in the fermentation process are ABC transport and amino acid biosynthesis. Most of the compounds such as L-arginine, L-aspartic acid, leucine, L-lysine, citrate, inosine, carnitine, betaine, and thiamine were significantly increased during fermentation, playing a role in enhancing food flavor. Compared with anaerobic fermentation, aerobic conditions led to a significant rise in the levels of some compounds such as valine, isoleucine, and glutamate; this increase was mainly related to branched-chain amino acid transaminase, isocitrate dehydrogenase, and glutamate dehydrogenase.DiscussionAerobic fermentation is more beneficial for the fermentation of Polygonati Rhizoma by L. plantarum to produce flavor and functional substances. This study is the first report on the fermentation of Polygonati Rhizoma by L. plantarum and provides insights that would be applicable in the development of Polygonati Rhizoma fermented products

Abnormal brain spontaneous activity in major depressive disorder adolescents with non-suicidal self injury and its changes after sertraline therapy

BackgroundNon-suicidal self-injury (NSSI) commonly occurs among adolescents with major depressive disorder (MDD), causing adverse effects on the physical and mental health of the patients. However, the underlying neurobiological mechanism of NSSI in adolescents with MDD (nsMDDs) remains unclear, and there are still challenges in the treatment. Studies have suggested that sertraline administration could be an effective way for treatment.MethodsTo verify the effectiveness and to explore the neurobiological processes, we treated a group of adolescents with nsMDDs with sertraline in this study. The brain spontaneous activity alteration was then investigated in fifteen unmedicated first-episode adolescent nsMDDs versus twenty-two healthy controls through the resting-state functional magnetic resonance imaging. Besides the baseline scanning for all participants, the nsMDDs group was scanned again after eight weeks of sertraline therapy to examine the changes after treatment.ResultsAt pre-treatment, whole brain analysis of mean amplitude of low-frequency fluctuation (mALFF) was performed to examine the neuronal spontaneous activity alteration, and increased mALFF was found in the superior occipital extending to lingual gyrus in adolescent nsMDDs compared with controls. Meanwhile, decreased mALFF was found in the medial superior frontal in adolescent nsMDDs compared with controls. Compared with the pre-treatment, the nsMDDs group was found to have a trend of, respectively, decreased and increased functional neuronal activity at the two brain areas after treatment through the region of interest analysis. Further, whole brain comparison of mALFF at pre-treatment and post-treatment showed significantly decreased spontaneous activity in the orbital middle frontal and lingual gyrus in adolescent nsMDDs after treatment. Also, depression severity was significantly decreased after treatment.ConclusionThe abnormal functional neuronal activity found at frontal and occipital cortex implied cognitive and affective disturbances in adolescent nsMDDs. The trend of upregulation of frontal neuronal activity and downregulation of occipital neuronal activity after sertraline treatment indicated that the therapy could be effective in regulating the abnormality. Notably, the significantly decreased neuronal activity in the decision related orbital middle frontal and anxiety-depression related lingual gyrus could be suggestive of reduced NSSI in adolescent MDD after therapy

Protecting public’s wellbeing against COVID-19 infodemic: The role of trust in information sources and rapid dissemination and transparency of information over time

ObjectivesThis study examined how trust in the information about COVID-19 from social media and official media as well as how the information was disseminated affect public’s wellbeing directly and indirectly through perceived safety over time.MethodsTwo online surveys were conducted in China, with the first survey (Time1, N = 22,718) being at the early stage of the pandemic outbreak and the second one (Time 2, N = 2,901) two and a half years later during the zero-COVID policy lockdown period. Key measured variables include trust in official media and social media, perceived rapid dissemination and transparency of COVID-19-related information, perceived safety, and emotional responses toward the pandemic. Data analysis includes descriptive statistical analysis, independent samples t-test, Pearson correlations, and structural equation modeling.ResultsTrust in official media, perceived rapid dissemination and transparency of COVID-19-related information, perceived safety, as well as positive emotional response toward COVID-19 increased over time, while trust in social media and depressive response decreased over time. Trust in social media and official media played different roles in affecting public’s wellbeing over time. Trust in social media was positively associated with depressive emotions and negatively associated with positive emotion directly and indirectly through decreased perceived safety at Time 1. However, the negative effect of trust in social media on public’s wellbeing was largely decreased at Time 2. In contrast, trust in official media was linked to reduced depressive response and increased positive response directly and indirectly through perceived safety at both times. Rapid dissemination and transparency of COVID-19 information contributed to enhanced trust in official media at both times.ConclusionThe findings highlight the important role of fostering public trust in official media through rapid dissemination and transparency of information in mitigating the negative impact of COVID-19 infodemic on public’s wellbeing over time

A Simple and Sensitive Method for Measuring Tumor-Specific T Cell Cytotoxicity

A simple and sensitive method to quantitatively measure the cytolytic effect of tumor-specific T killer cells is highly desirable for basic and clinical studies. Chromium (51Cr) release assay has been the “gold standard” for quantifying cytolytic activities of cytotoxic T lymphocytes (CTLs) against target cells and this method is still being used in many laboratories. However, a major drawback of this method is the use of radioactive materials, which is inconvenient to handle because of environmental safety concerns and expensive due to the short half-life of the isotope. Consequently, several nonradioactive methods have been reported recently. Here we report a new method that we recently developed for quantifying antigen-specific cytolytic activity of CTLs. This method fully exploits the high sensitivity and the relative simplicity of luciferase quantitative assay. We initially expected the released luciferase in the supernatant to be the adequate source for monitoring cell death. However, to our total surprise, incubation of these killer T cells with the tumor cell targets did not result in significant release of luciferase in the culture medium. Instead, we found that the remaining luciferase inside the cells could accurately reflect the overall cell viability

Hunting imaging biomarkers in pulmonary fibrosis: Benchmarks of the AIIB23 challenge

Airway-related quantitative imaging biomarkers are crucial for examination, diagnosis, and prognosis in pulmonary diseases. However, the manual delineation of airway structures remains prohibitively time-consuming. While significant efforts have been made towards enhancing automatic airway modelling, current public-available datasets predominantly concentrate on lung diseases with moderate morphological variations. The intricate honeycombing patterns present in the lung tissues of fibrotic lung disease patients exacerbate the challenges, often leading to various prediction errors. To address this issue, the 'Airway-Informed Quantitative CT Imaging Biomarker for Fibrotic Lung Disease 2023' (AIIB23) competition was organized in conjunction with the official 2023 International Conference on Medical Image Computing and Computer Assisted Intervention (MICCAI). The airway structures were meticulously annotated by three experienced radiologists. Competitors were encouraged to develop automatic airway segmentation models with high robustness and generalization abilities, followed by exploring the most correlated QIB of mortality prediction. A training set of 120 high-resolution computerised tomography (HRCT) scans were publicly released with expert annotations and mortality status. The online validation set incorporated 52 HRCT scans from patients with fibrotic lung disease and the offline test set included 140 cases from fibrosis and COVID-19 patients. The results have shown that the capacity of extracting airway trees from patients with fibrotic lung disease could be enhanced by introducing voxel-wise weighted general union loss and continuity loss. In addition to the competitive image biomarkers for mortality prediction, a strong airway-derived biomarker (Hazard ratio&gt;1.5, p &lt; 0.0001) was revealed for survival prognostication compared with existing clinical measurements, clinician assessment and AI-based biomarkers