Differentiating enantiomers by directional rotation of ions in a mass spectrometer.

Conventional mass spectrometry does not distinguish between enantiomers, or mirror-image isomers. Here we report a technique to break the chiral symmetry and to differentiate enantiomers by inducing directional rotation of chiral gas-phase ions. Dual alternating current excitations were applied to manipulate the motions of trapped ions, including the rotation around the center of mass and macro movement around the center of the trap. Differences in collision cross section were induced, which could be measured by ion cloud profiling at high resolutions above 10,000. High-field ion mobility and tandem mass spectrometry analyses of the enantiomers were combined and implemented by using a miniature ion trap mass spectrometer. The effectiveness of the developed method was demonstrated with a variety of organic compounds including amino acids, sugars, and several drug molecules, as well as a proof-of-principle ligand optimization study for asymmetric hydrogenation.

Dynamic Hydrogels with Viscoelasticity and Tunable Stiffness for the Regulation of Cell Behavior and Fate.

The extracellular matrix (ECM) of natural cells typically exhibits dynamic mechanical properties (viscoelasticity and dynamic stiffness). The viscoelasticity and dynamic stiffness of the ECM play a crucial role in biological processes, such as tissue growth, development, physiology, and disease. Hydrogels with viscoelasticity and dynamic stiffness have recently been used to investigate the regulation of cell behavior and fate. This article first emphasizes the importance of tissue viscoelasticity and dynamic stiffness and provides an overview of characterization techniques at both macro- and microscale. Then, the viscoelastic hydrogels (crosslinked via ion bonding, hydrogen bonding, hydrophobic interactions, and supramolecular interactions) and dynamic stiffness hydrogels (softening, stiffening, and reversible stiffness) with different crosslinking strategies are summarized, along with the significant impact of viscoelasticity and dynamic stiffness on cell spreading, proliferation, migration, and differentiation in two-dimensional (2D) and three-dimensional (3D) cell cultures. Finally, the emerging trends in the development of dynamic mechanical hydrogels are discussed.

High-resolution separation of bioisomers using ion cloud profiling.

Elucidation of complex structures of biomolecules plays a key role in the field of chemistry and life sciences. In the past decade, ion mobility, by coupling with mass spectrometry, has become a unique tool for distinguishing isomers and isoforms of biomolecules. In this study, we develop a concept for performing ion mobility analysis using an ion trap, which enables isomer separation under ultra-high fields to achieve super high resolutions over 10,000. The potential of this technology has been demonstrated for analysis of isomers for biomolecules including disaccharides, phospholipids, and peptides with post-translational modifications.

Ultrathin Flexible Encapsulation Materials Based on Al2O3/Alucone Nanolaminates for Improved Electrical Stability of Silicon Nanomembrane-Based MOS Capacitors.

Ultrathin flexible encapsulation (UFE) using multilayered films has prospects for practical applications, such as implantable and wearable electronics. However, existing investigations of the effect of mechanical bending strains on electrical properties after the encapsulation procedure provide insufficient information for improving the electrical stability of ultrathin silicon nanomembrane (Si NM)-based metal oxide semiconductor capacitors (MOSCAPs). Here, we used atomic layer deposition and molecular layer deposition to generate 3.5 dyads of alternating 11 nm Al2O3 and 3.5 nm aluminum alkoxide (alucone) nanolaminates on flexible Si NM-based MOSCAPs. Moreover, we bent the MOSCAPs inwardly to radii of 85 and 110.5 mm and outwardly to radii of 77.5 and 38.5 mm. Subsequently, we tested the unbent and bent MOSCAPs to determine the effect of strain on various electrical parameters, namely the maximum capacitance, minimum capacitance, gate leakage current density, hysteresis voltage, effective oxide charge, oxide trapped charge, interface trap density, and frequency dispersion. The comparison of encapsulated and unencapsulated MOSCAPs on these critical parameters at bending strains indicated that Al2O3/alucone nanolaminates stabilized the electrical and interfacial characteristics of the Si NM-based MOSCAPs. These results highlight that ultrathin Al2O3/alucone nanolaminates are promising encapsulation materials for prolonging the operational lifetimes of flexible Si NM-based metal oxide semiconductor field-effect transistors.

Evaluating the Efficacy of EGFR-TKIs Combined With Radiotherapy in Advanced Lung Adenocarcinoma Patients With EGFR Mutation: A Retrospective Study.

Objective: Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) have been recommended as the first-line treatment for advanced lung adenocarcinoma with epidermal growth factor receptor (EGFR) mutation. This study retrospectively evaluated patients' survival and related prognostic factors from single-center, real-world data. Methods: From January 2015 to December 2020, patients detected with EGFR mutation showing unresectable clinical stages III to IV advanced lung adenocarcinoma and receiving EGFR-TKIs and radiotherapy (RT) were recruited for the study. The overall survival (OS) and progression-free survival (PFS) were statistically analyzed with SPSS 22.0 software. Results: This study included 238 patients who completed their follow-up by December 30, 2020. The 1-, 2-, 3-year and median OS were 84.4%, 59.7%, 38.7%, and 30.3 months for OS, 57.0%, 28.8%, 15.7%, and 14.1 months for progression-free survival (PFS1), and 78.9%, 71.7%, 33.3%, and 25.0 months for PFS2, respectively. Multivariate analysis showed that, the independent factors for OS are age, clinical stage, the sequence of TKI and CT, and the total treatment response, and total response; the independent factors for progression-free survival 1 are clinical stage and total treatment response; the independent factors for PFS2 are clinical stage, type of TKI, sequence of TKI and CT, and total treatment response. The univariate analysis also showed a significant association between RT duration (P = 0.041) and dose (P = 0.026) with PFS1. Conclusion: EGFR-TKIs combined with RT was tolerable and efficient for patients with advanced lung adenocarcinoma. OS and PFS prove CT sequential with TKIs. Better treatment response with CR + PR was associated with a longer duration of OS, PFS1, and PFS2. However, further study is required in a larger sample size to confirm the results.

Identification of the Wheat (Triticum aestivum) IQD Gene Family and an Expression Analysis of Candidate Genes Associated with Seed Dormancy and Germination

The IQ67 Domain (IQD) gene family plays important roles in plant developmental processes and stress responses. Although IQDs have been characterized in model plants, little is known about their functions in wheat (Triticum aestivum), especially their roles in the regulation of seed dormancy and germination. Here, we identified 73 members of the IQD gene family from the wheat genome and phylogenetically separated them into six major groups. Gene structure and conserved domain analyses suggested that most members of each group had similar structures. A chromosome positional analysis showed that TaIQDs were unevenly located on 18 wheat chromosomes. A synteny analysis indicated that segmental duplications played significant roles in TaIQD expansion, and that the IQD gene family underwent strong purifying selection during evolution. Furthermore, a large number of hormone, light, and abiotic stress response elements were discovered in the promoters of TaIQDs, implying their functional diversity. Microarray data for 50 TaIQDs showed different expression levels in 13 wheat tissues. Transcriptome data and a quantitative real-time PCR analysis of wheat varieties with contrasting seed dormancy and germination phenotypes further revealed that seven genes (TaIQD4/-28/-32/-58/-64/-69/-71) likely participated in seed dormancy and germination through the abscisic acid-signaling pathway. The study results provide valuable information for cloning and a functional investigation of candidate genes controlling wheat seed dormancy and germination; consequently, they increase our understanding of the complex regulatory networks affecting these two traits.

Relatedness Need Satisfaction and the Dark Triad: The Role of Depression and Prevention Focus.

Dark triad traits are often associated with maladaptive social and interpersonal interactions, such as dishonesty and self-centeredness; thus, it is important to explore predictors of the dark triad in order to better facilitate the reduction of such behaviors. The present study adopted a self-report approach with a total of 5,207 Chinese undergraduate students participated in the study. We found that relatedness need dissatisfaction significantly predicted the presence of dark personalities, which was mediated by prevention focus. Conditional process model analysis found that this mediating effect was stronger when depression levels were lower. Final study results contributed to further understanding predictors of the dark triad. Study limitations and future research directions were also examined.