Organoboronates are synthetically useful and highly valuable building blocks in synthetic and medicinal chemistry. Two‐electron reactions allow for the rapid construction of organoboronates via ...nucleophilic 1,2‐boron shift of boron ate complexes or MIDA‐mediated 1,2‐boryl migration. Radical approaches through 1,2‐boron shift of neutral boronic esters or boron ate complexes have been demonstrated to be feasible, providing complementary methods to access these privileged scaffolds. In this Review, recent achievements are highlighted and future opportunities are discussed, with an emphasis on different operative modes of catalysis and reaction pathways.
Preparation of organoboronates is highly valuable in synthetic chemistry, material science and medicinal chemistry. In this Review, recent advances to access this privileged scaffold via 1,2‐boryl migration are discussed. Two complementary methods by ionic or radical mechanism have been systematically introduced.
Asymmetric cross‐couplings based on 1,2‐carbon migration from B‐ate complexes have been developed efficiently to access valuable organoboronates. However, enantioselective reactions triggered by ...1,2‐boron shift have remained to be unaddressed synthetic challenge. Here, Ir‐catalyzed asymmetric allylic alkylation enabled by 1,2‐boron shift was developed. In this reaction, we disclosed that excellent enantioselectivities were achieved through an interesting dynamic kinetic resolution (DKR) process of allylic carbonates at the elevated temperature. Notably, the highly valuable (bis‐boryl)alkenes have enabled an array of diversifications to access versatile molecules. Extensive experimental and computational studies were conducted to elucidate the reaction mechanism of DKR process and clarify the origin of excellent enantioselectivities.
We have developed an Ir‐catalyzed asymmetric allylic alkylation via 1,2‐boron shift to access enantioenriched gem‐diborylalkenes. In this reaction, excellent enantioselectivities were obtained by simply improving the reaction temperature via an impressive DKR process. DFT calculations and extensive mechanistic studies were conducted to elucidate the reaction mechanism and the origin of excellent enantioselectivities.
Hemorrhagic fever with renal syndrome (HFRS) caused by hantaviruses is a serious public health problem in China, accounting for 90% of HFRS cases reported globally. In this study, we applied ...geographical information system (GIS), spatial autocorrelation analyses and a seasonal autoregressive-integrated moving average (SARIMA) model to describe and predict HFRS epidemic with the objective of monitoring and forecasting HFRS in mainland China. Chinese HFRS data from 2004 to 2016 were obtained from National Infectious Diseases Reporting System (NIDRS) database and Chinese Centre for Disease Control and Prevention (CDC). GIS maps were produced to detect the spatial distribution of HFRS cases. The Moran's I was adopted in spatial global autocorrelation analysis to identify the integral spatiotemporal pattern of HFRS outbreaks, while the local Moran's Ii was performed to identify ‘hotspot’ regions of HFRS at province level. A fittest SARIMA model was developed to forecast HFRS incidence in the year 2016, which was selected by Akaike information criterion and Ljung–Box test. During 2004–2015, a total of 165 710 HFRS cases were reported with the average annual incidence at province level ranged from 0 to 13.05 per 100 000 persons. Global Moran's I analysis showed that the HFRS outbreaks presented spatially clustered distribution, with the degree of cluster gradually decreasing from 2004 to 2009, then turned out to be randomly distributed and reached lowest point in 2012. Local Moran's Ii identified that four provinces in northeast China contributed to a ‘high–high’ cluster as a traditional epidemic centre, and Shaanxi became another HFRS ‘hotspot’ region since 2011. The monthly incidence of HFRS decreased sharply from 2004 to 2009 in mainland China, then increased markedly from 2010 to 2012, and decreased again since 2013, with obvious seasonal fluctuations. The SARIMA ((0,1,3) × (1,0,1)12) model was the most fittest forecasting model for the dataset of HFRS in mainland China. The spatiotemporal distribution of HFRS in mainland China varied in recent years; together with the SARIMA forecasting model, this study provided several potential decision supportive tools for the control and risk-management plan of HFRS in China.
The prevalence of obesity and diabetes mellitus (DM) has been consistently increasing worldwide. Sharing powerful genetic and environmental features in their pathogenesis, obesity amplifies the ...impact of genetic susceptibility and environmental factors on DM. The ectopic expansion of adipose tissue and excessive accumulation of certain nutrients and metabolites sabotage the metabolic balance via insulin resistance, dysfunctional autophagy, and microbiome-gut-brain axis, further exacerbating the dysregulation of immunometabolism through low-grade systemic inflammation, leading to an accelerated loss of functional β-cells and gradual elevation of blood glucose. Given these intricate connections, most available treatments of obesity and type 2 DM (T2DM) have a mutual effect on each other. For example, anti-obesity drugs can be anti-diabetic to some extent, and some anti-diabetic medicines, in contrast, have been shown to increase body weight, such as insulin. Meanwhile, surgical procedures, especially bariatric surgery, are more effective for both obesity and T2DM. Besides guaranteeing the availability and accessibility of all the available diagnostic and therapeutic tools, more clinical and experimental investigations on the pathogenesis of these two diseases are warranted to improve the efficacy and safety of the available and newly developed treatments.
The quest for a solid state universal memory with high-storage density, high read/write speed, random access and non-volatility has triggered intense research into new materials and novel device ...architectures. Though the non-volatile memory market is dominated by flash memory now, it has very low operation speed with ~10 μs programming and ~10 ms erasing time. Furthermore, it can only withstand ~10(5) rewriting cycles, which prevents it from becoming the universal memory. Here we demonstrate that the significant photovoltaic effect of a ferroelectric material, such as BiFeO3 with a band gap in the visible range, can be used to sense the polarization direction non-destructively in a ferroelectric memory. A prototype 16-cell memory based on the cross-bar architecture has been prepared and tested, demonstrating the feasibility of this technique.
Low temperature is one of the most important abiotic factors inhibiting growth, productivity, and distribution of rapeseed (Brassica napus L.). Therefore, it is important to identify and cultivate ...cold-tolerant germplasm. The objective of this study was to figure out the mechanism of chilling (4 and 2°C) and freezing (–2 and –4°C) stresses along with a control (22°C) in B. napus cultivars (1801 and C20) under controlled environment (growth chamber). The experiment was arranged in a complete randomized design with three replications. Our results exhibited that under chilling and freezing stresses, the increment of proline accumulation, soluble sugar and protein contents, and antioxidant enzyme activity were enhanced more in 1801 cultivar compared with C20 cultivar. At –2 and –4°C, the seedlings of C20 cultivar died completely compared with 1801 cultivar. Hydrogen peroxide (H2O2) and malondialdehyde contents (MDA) increased in both cultivars, but when the temperature was decreased up to –2 and –4°C, the MDA and H2O2 contents continuously dropped in 1801 cultivar. Moreover, we found that leaf abscisic acid (ABA) was enhanced in 1801 cultivar under chilling and freezing stresses. Additionally, the transcriptional regulations of cold-tolerant genes (COLD1, CBF4, COR6.6, COR15, and COR25) were also determined using real-time quantitative PCR (RT-qPCR). RT-qPCR showed that higher expression of these genes were found in 1801 as compared to C20 under cold stress (chilling and freezing stresses). Therefore, it is concluded from this experiment that 1801 cultivar has a higher ability to respond to cold stress (chilling and freezing stresses) by maintaining hormonal, antioxidative, and osmotic activity along with gene transcription process than C20. The result of this study will provide a solid foundation for understanding physiological and molecular mechanisms of cold stress signaling in rapeseed (B. napus).
Diabetic kidney disease (DKD) is a common and serious complication in patients with diabetic mellitus (DM), the risk of cardiovascular events and all-cause mortality also increases in DKD patients. ...This study aimed to detect the influencing factors of DKD in type 2 DM (T2DM) patients, and construct DKD prediction models and nomogram for clinical decision-making.
A total of 14,628 patients with T2DM were included. These patients were divided into pre-DKD and non-DKD groups, depending on the occurrence of DKD during a 3-year follow-up from first clinic attendance. The influencing indicators of DKD were analyzed, the prediction models were established by multivariable logistic regression, and a nomogram was drawn for DKD risk assessment.
Two prediction models for DKD were built by multivariate logistic regression analysis. Model 1 was created based on 17 variables using the forward selection method, Model 2 was established by 19 variables using the backward elimination method. The Somers' D values of both models were 0.789. Four independent predictors were selected to build the nomogram, including age, UACR, eGFR, and neutrophil percentages. The C-index of the nomogram reached 0.864, suggesting a good predictive accuracy for DKD development.
Our prediction models had strong predictive powers, and our nomogram provided visual aids to DKD risk calculation, which was simple and fast. These algorithms can provide early DKD risk prediction, which might help to improve the medical care for early detection and intervention in T2DM patients, and then consequently improve the prognosis of DM patients.
We examined, in five studies, the relation between nostalgia and financial risk taking. We hypothesized that nostalgia increases risk taking by fostering perceptions of social support. In Study 1, we ...established the basic effect of nostalgia and increased risk taking. In Study 2, we used a measurement-of-mediation approach to specify the underlying mechanism. Perceived support from family members, rather than from significant others or friends, mediated the relation between nostalgia and risk taking. In Studies 3 to 4, we further specified the mediating mechanism (i.e., family social support) and established direction of causality by using an experimental-causal-chain approach. Finally, in Study 5, we provided direct experimental evidence of the full mediation model. Taken together, nostalgia galvanizes perceived family support, which propels individuals toward financial risk.
Selective macroautophagy of the endoplasmic reticulum (ER) and the nucleus, known as ER-phagy and nucleophagy, respectively, are processes whose mechanisms remain inadequately understood. Through an ...imaging-based screen, we find that in the fission yeast Schizosaccharomyces pombe, Yep1 (also known as Hva22 or Rop1), the ortholog of human REEP1-4, is essential for ER-phagy and nucleophagy but not for bulk autophagy. In the absence of Yep1, the initial phase of ER-phagy and nucleophagy proceeds normally, with the ER-phagy/nucleophagy receptor Epr1 coassembling with Atg8. However, ER-phagy/nucleophagy cargos fail to reach the vacuole. Instead, nucleus- and cortical-ER-derived membrane structures not enclosed within autophagosomes accumulate in the cytoplasm. Intriguingly, the outer membranes of nucleus-derived structures remain continuous with the nuclear envelope-ER network, suggesting a possible outer membrane fission defect during cargo separation from source compartments. We find that the ER-phagy role of Yep1 relies on its abilities to self-interact and shape membranes and requires its C-terminal amphipathic helices. Moreover, we show that human REEP1-4 and budding yeast Atg40 can functionally substitute for Yep1 in ER-phagy, and Atg40 is a divergent ortholog of Yep1 and REEP1-4. Our findings uncover an unexpected mechanism governing the autophagosomal enclosure of ER-phagy/nucleophagy cargos and shed new light on the functions and evolution of REEP family proteins.
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