Parallel kinetic resolution of aziridines via chiral phosphoric acid-catalyzed apparent hydrolytic ring-opening.

We report a chiral phosphoric acid catalyzed apparent hydrolytic ring-opening reaction of racemic aziridines in a regiodivergent parallel kinetic resolution manner. Harnessing the acyloxy-assisted strategy, the highly stereocontrolled nucleophilic ring-opening of aziridines with water is achieved. Different kinds of aziridines are applicable in the process, giving a variety of enantioenriched aromatic or aliphatic amino alcohols with up to 99% yields and up to >99.5 : 0.5 enantiomeric ratio. Preliminary mechanistic study as well as product elaborations were inducted as well.

Study on the Pore Structure of Lightweight Mortar with Nano-Additives.

With the development of nanotechnology, nanomaterials have been introduced to improve the engineering properties of cement-based building materials. An abundant number of studies have been carried out on normal-weight concrete using multi-walled carbon nanotubes (MWCNTs) or nano-silica (NS) and have proven their effectiveness. Nevertheless, still very few investigations are available in terms of lightweight cement-based materials, especially when MWCNTs and NS are binarily incorporated. Thus, in this study, fly ash cenospheres (FACs) according to cement weight were applied as lightweight fine aggregates to produce lightweight mortar (LWM). MWCNTs at 0.05, 0.15, and 0.45% and NS at 0.2 and 1.0% were binarily added as modifiers. Compressive and flexural strengths were tested to investigate mechanical behaviors. A water absorption test was conducted, together with scanning electron microscopy (SEM) and mercury intrusion porosimetry (MIP), to identify the impacts of the nano-additives on the pore structure of LWM. The following results were obtained: MWCNTs and NS demonstrated synergic effects on enhancing the mechanical properties of LWM. MWCNTs exerted positive impacts on reducing the porosity and improving the pore distribution at low dosages of 0.05 and 0.15%. The hybrid addition of NS further transformed large voids into small ones and introduced closed pores.

Association of sleep-related disorders with cardiovascular disease among adults in the United States: A cross-sectional study based on national health and nutrition examination survey 2005-2008.

Background and objective: The association between sleep-related disorders and cardiovascular diseases (CVDs) remains controversial and lacks epidemiological evidence in the general population. We investigated whether sleep-related disorders are related to CVDs in a large, nationally representative, diverse sample of American adults. Materials and methods: Data were collected from the National Health and Nutrition Examination Survey (NHANES) 2005-2008. Logistic regression was performed to explore associations of sleep-related disorders with the prevalence of total and specific CVDs. Stratified subgroup analysis was performed to exclude interactions between variables and sleep-related disorders. Non-linearity was explored using restricted cubic splines. Results: In total, 7,850 participants aged over 20 years were included. After controlling for confounders, multivariate regression analysis showed that sleep problems were associated increases in risk of 75% for CVD (OR: 1.75; 95% CI 1.41, 2.16), 128% for congestive heart failure (CHF) (OR: 2.28; 95% CI 1.69, 3.09), 44% for coronary heart disease (CHD) (OR: 1.44; 95% CI 1.12, 1.85), 96% for angina pectoris (AP) (OR: 1.96; 95% CI 1.40, 2.74), 105% for heart attack (OR: 2.05; 95% CI 1.67, 2.53) and 78% for stroke (OR: 1.78; 95% CI 1.32, 2.40). Daytime sleepiness was associated increases in risk of 54% for CVD (OR: 1.54; 95% CI 1.25, 1.89), 73% for CHF (OR: 1.73; 95% CI 1.22, 2.46), 53% for AP (OR: 1.53; 95% CI 1.12, 2.10), 51% for heart attack (OR: 1.51; 95% CI 1.18, 1.95), and 60% for stroke (OR: 1.60; 95% CI 1.09, 2.36). Participants with insufficient sleep had a 1.42-fold higher likelihood of CVD (OR: 1.42; 95% CI 1.13, 1.78) and a 1.59-fold higher likelihood of heart attack (OR: 1.59; 95% CI 1.19, 2.13) than participants with adequate sleep. Prolonged sleep-onset latency was associated with an increased risk of CVD (OR: 1.59; 95% CI 1.17, 2.15), CHF (OR: 2.08; 95% CI 1.33, 3.23) and heart attack (OR: 1.76; 95% CI 1.29, 2.41). Short sleep-onset latency was associated with a 36% reduction in stroke risk (OR: 0.64; 95% CI 0.45, 0.90). The association of sleep problems with CVD risk was more pronounced in the group younger than 60 years (p for interaction = 0.019), and the relationship between short sleep-onset latency and total CVD differed by sex (p for interaction = 0.049). Additionally, restricted cubic splines confirmed a linear relationship between sleep-onset latency time and CVD (p for non-linearity = 0.839) and a non-linear relationship between sleep duration and CVD (p for non-linearity <0.001). Conclusion: According to a limited NHANES sample used to examine sleep-related disorders and CVD, total and specific CVDs could be associated with certain sleep-related disorders. Additionally, our study uniquely indicates that CVD risk should be considered in participants younger than 60 years with sleep problems, and shortened sleep-onset latency may be a CVD protective factor in females.

Ionic liquid-induced in situ deposition of perovskite quantum dot films with a photoluminescence quantum yield of over 85.

Metal halide perovskite quantum dots (QDs) hold great promise as building blocks for next-generation light emitting devices (LEDs). The preparation of perovskite QD films with high photoluminescence quantum yield (PLQY) is the key to realizing efficient LEDs. However, the conventional deposition method of spin-coating of pre-synthesized QD ink solutions results in perovskite QD films with low PLQY (typically <45%) due to non-radiative recombination centers induced in the deposition process. Here, by utilizing the ionic nature and steric hindrance effect of the ionic liquid, we demonstrate an in situ deposition method for perovskite QD films with high PLQY by directly spin-coating precursor solutions containing an ionic liquid. Furthermore, mechanistic study reveals that the ionic liquid not only induces the formation of QDs but also suppresses defect-related recombination through the interaction with uncoordinated metal atoms on the surface of the QDs. As a result, the in situ deposited CsPbBr3 QD film with a PLQY as high as 85.2% and long-term air stability is achieved. These findings demonstrate that the introduction of an ionic liquid provides an effective strategy to enhance the performance of in situ formed perovskite QD films, which could benefit the development of efficient LEDs and other optoelectronic devices.

Revealing the Aging Effect of Metal-Oleate Precursors on the Preparation of Highly Luminescent CsPbBr3 Nanoplatelets.

Due to the ultrafast crystallization process in the triple-source ligand-assisted reprecipitation (TSLARP) technique the [LyPbBrx] octahedra is easily distorted, resulting in anisotropic two-dimensional nanoplatelets (NPLs) with low photoluminescence quantum yield (PLQY) and poor stability. Unexpectedly, we obtain CsPbBr3 NPLs with PLQY approaching unity and high stability using the TSLARP technique through aging the metal-oleate precursors. We find that the significant enhancement of the PLQY is related to the change of solution chemistry of the Pb-oleate precursor in the aging process. While hybrid CsPbBr3@Cs4PbBr6 NPLs with low PLQY (28%) are formed with fresh Pb-oleate precursor, phase-pure CsPbBr3 NPLs with PLQY of 97.4% are obtained with the aged Pb-oleate precursor. A model that takes into account the transformation of the Pb-oleate in toluene from isolated molecules into clusters after aging is proposed to explain the phenomenon. Our finding highlights the importance of understanding the solution chemistry for the synthesis of the highly luminescent NPLs and provides a new way to break the "blue-wall" in perovskite light-emitting devices.

Expression of TS, RRM1, ERCC1, TUBB3 and STMN1 Genes in Tissues of Non-small Cell Lung Cancer and its Significance in Guiding Postoperative Adjuvant Chemotherapy.

BACKGROUND: To explore the expression of TS, RRM, ERCC1, TUBB3 and STMN1 genes in the tissues of patients with non-small cell lung cancer (NSCLC) and its significance in guiding the postoperative adjuvant chemotherapy. MATERIALS AND METHODS: Real time polymerase chain reaction (PCR) was applied to detect the expression of TS, RRM, ERCC1, TUBB3 and STMN1 genes in the tissues of NSCLC patients so as to analyze the relationship between the expression of each gene and the clinical characteristics and to guide the postoperative individualized chemotherapy according to the detection results of NSCLC patients. RESULTS: Expression of TS gene was evidently higher in patients with adenocarcinoma than those with non-adenocarcinoma (P=0.013) and so was the expression of ERCC1 (P=0.003). The expression of TUBB3 gene was obviously higher in NSCLC patients in phases I/II and IV than those in phase III (P1=0.021; P2=0.004), and it was also markedly higher in patients without lymph node metastasis than those with (P=0.008). The expression of STMN1 gene was apparently higher in patients in phase I/II than those in phase IV (P=0.002). There was no significant difference between the rest gene expression and the clinical characteristics of NSCLC patients (P>0.05). Additionally, the disease- free survival (DFS) was significantly longer in patients receiving gene detections than those without (P=0.021). CONCLUSIONS: The selection of chemotherapeutic protocols based singly on patients' clinical characteristics has certain blindness. However, the detection of tumor-susceptible genes can guide the postoperative adjuvant chemotherapy and prolong the DFS of NSCLC patients.