Described herein is the behavior of α,ω‐dienes sequestered within cavitands in aqueous (D2O) solution. Hydrophobic forces drive the dienes into the cavitands in conformations that best fill the ...available space. Shorter dienes (C9 and C10) bind in compressed conformations that tumble rapidly in the cavitands. Longer dienes induce capsule formation between cavitands with self‐complementary hydrogen bonding sites, where the dienes exist in extended conformations. In cavitands unable to form capsules, longer dienes adopt folded structures. The wider open ends allow the synthesis of medium‐sized cycloalkenes by ring‐closing metathesis reactions with the Hoveyda–Grubbs‐II catalyst. Yields of cycloheptene and cyclooctene were enhanced by the chaperones in water when compared with reactions of the free dienes in either aqueous media or chloroform, and even cyclononene could be prepared within the cavitand.
Rough and tumble: Hydrophobic forces drive α,ω‐dienes into cavitands in conformations that best fill the available space. Shorter dienes (C9 and C10) bind in compressed conformations that tumble rapidly within the cavitands. The cavitands enhanced the synthesis of medium‐sized cycloalkenes by ring‐closing metathesis compared with reactions of the free dienes in either aqueous media or chloroform.
In recent past years, investigation of hierarchical self-assembly for constructing artificial functional materials has attracted considerable attention. Discrete metallacycles based on coordination ...bonds have proven to be valid scaffolds to fabricate various supramolecular polymers or smart soft matter through hierarchical self-assembly. Here, we present the first example of the hierarchical self-assembly of discrete metallacycles by taking advantage of the positive charges of the organoplatinum(II) metallacycle skeleton through multiple electrostatic interactions. Heparin, a sulfated glycosaminoglycan polymer that has been widely used as an anticoagulant drug, was selected to induce hierarchical self-assembly because of the existence of multiple negative charges. To investigate the hierarchical self-assembly process, an aggregation-induced emission (AIE) active moiety, tetra-phenylethylene (TPE), was introduced onto the metallacycle via coordination-driven self-assembly. Photophysical studies revealed that the addition of heparin to the tris-TPE metallacycles solution resulted in dramatic fluorescence enhancement, which supported the aggregation between metallacycle and heparin driven by multiple electrostatic interactions. Moreover, the entangled pearl-necklace networks were obtained through hierarchical self-assembly as detected by SEM, TEM, and LSCM experiments. In particular, single bead-like chains were observed in the AFM and TEM images, which provided direct, visual evidence for the aggregation of positively charged metallacycles and negatively charged heparin. More interestingly, further optical study demonstrated that this TPE-decorated metallacycle could function as a turn-on fluorescent probe for heparin detection with high sensitivity and selectivity. Thus, this research presents the first example of counter polyanion-induced hierarchical self-assembly of discrete metallacycles and provides a “proof-of-principle” method for heparin sensing and binding.
Cyclic processes involving medium-sized rings show low rates because internal strainstorsions and transannular interactionsare created during the reactions. High dilution is often used to slow the ...competing bi- and higher-molecular processes but cannot accelerate the desired cyclization reaction. Here we apply cavitands to the formation of medium- to large-sized rings through conversion of long-chain diisocyanates to cyclic ureas. The reactions take place in aqueous (D2O) solution, where hydrophobic forces drive the starting materials into the cavitands in folded conformations. The guest assumes the shape to fill the space properly, which brings the reacting ends closer together than they are in bulk solvent. Complexation overcomes some of the internal strains involved in precyclization shapes of the guest molecules and accelerates the cyclization. The results augur well for applications of water-soluble cavitands to related processes such as remote functionalization reactions.
The apolipoprotein E ɛ4 allele (APOE4) is universally acknowledged as the most potent genetic risk factor for Alzheimer's disease (AD). APOE4 promotes the initiation and progression of AD. Although ...the underlying mechanisms are unclearly understood, differences in lipid‐bound affinity among the three APOE isoforms may constitute the basis. The protein APOE4 isoform has a high affinity with triglycerides and cholesterol. A distinction in lipid metabolism extensively impacts neurons, microglia, and astrocytes. APOE4 carriers exhibit phenotypic differences from non‐carriers in clinical examinations and respond differently to multiple treatments. Therefore, we hypothesized that phenotypic classification of AD patients according to the status of APOE4 carrier will help specify research and promote its use in diagnosing and treating AD. Recent reviews have mainly evaluated the differences between APOE4 allele carriers and non‐carriers from gene to protein structures, clinical features, neuroimaging, pathology, the neural network, and the response to various treatments, and have provided the feasibility of phenotypic group classification based on APOE4 carrier status. This review will facilitate the application of APOE phenomics concept in clinical practice and promote further medical research on AD.
Genetic variation in the APOE genotype form the basis of the clinical phenotype.
Smart card based authentication scheme has been widely utilized for various transaction-oriented services such as electronic currency exchange, social insurance payment and e-commerce payment charge ...in modern society. How to develop a smart card based authentication scheme to support initiator untraceability and defend against major security threats for a transaction service user has become a crucial topic for researchers. Recent efforts for developing anonymous authentication scheme with smart card have failed to provide initiator untraceability for user or been vulnerable to some security attacks. This paper first presents a security model for anonymous authentication and then proposes a new anonymous authentication scheme using smart card. Security robustness of the proposed scheme is constructed by one-way hash function and elliptic curve cryptosystem. Our security analysis shows that the proposed scheme achieves general security requirement and offers initiator untraceability for user without requiring database support. Performance analysis on communication overhead and computation cost shows that the proposed scheme has better or similar efficiency in comparison with other existing smart card based authentication schemes.
Helicobacter pylori infection is known to decrease the incidences of autoimmune diseases and inflammatory bowel disease(IBD). Our aim was investigating the effect of H. pylori treatment in diabetes ...mellitus(DM) patients.
Adults with newly-diagnosed H. pylori infection or peptic ulcer disease(PUD) within the general population and DM population were identified from the National Health Insurance Research Database of Taiwan from 2000-2010. 79,181 patients were assigned to the 3 groups: general population with PUD without H. pylori treatment(PUD-HPRx in general population), DM patients with PUD without H. pylori treatment(PUD-HPRx in DM), and DM patients with PUD who received H. pylori treatment(PUD+HPRx in DM).
Higher incidences of autoimmune diseases and IBD were observed in the PUD+HPRx in DM group than in the PUD-HPRx in general population and PUD-HPRx in DM groups (autoimmune diseases = 5.14% vs 3.47% and 3.65%; IBD = 5.60% vs 3.17% and 3.25%; P<0.0001). A lower all-cause mortality was noted in the PUD+HPRx in DM group (HR: 0.937, P<0.001) than in the PUD-HPRx in DM group. Trends of a higher incidence of IBD and a lower mortality in younger patients in the PUD+HPRx in DM group compared with the PUD-HPRx in DM group were noted.
The results revealed that H. pylori treatment increased the incidences of autoimmune diseases and IBD and decreased the all-cause mortality in the DM group with PUD. The effect was more significant in younger patients. This finding assists in realizing the influence of H. pylori treatment in the DM population.
This study introduces a recent field experiment investigating multiscale terrain–circulation–precipitation interactions. When a synoptic‐scale northeasterly wind prevails under the active East Asian ...winter monsoon, stratocumulus cloud decks with severe rainfall exceeding 100 mm·day−1 frequently occur in the northeastern plain area and adjacent mountains in Yilan, Taiwan. The Yilan Experiment of Severe Rainfall (YESR2020) is a field campaign from November 20, 2020, to November 24, 2020, to survey the physical processes leading to severe wintertime rainfall. The three‐dimensional structure of the wind field and the atmospheric environment can be identified through high temporal and spatial resolution sounding observations, which is empowered by the novel Storm Tracker mini‐radiosonde. During YESR2020, the continuously collected meteorological data of two northeasterly episodes captured the variability of local‐scale wind patterns and the features of the severe rainfall induced by stratocumulus. A preliminary analysis indicated that a local‐scale convergence line could appear over the plain area of Yilan under the northeasterly environmental condition. The precipitation hotspot was located in the mountain region of southern Yilan, where the local winds signified turbulence features. Moreover, the severe rainfall of the two northeasterly episodes spotlighted shallow cumulus under stratus with pure warm rain processes. The results of YESR2020 inspire the arrangement of future field observations to explore detailed mechanisms of heavily precipitating stratocumulus over complex topography.
We conducted the Yilan Experiment of Severe Rainfall (YESR2020) to survey physical processes leading to severe rainfall in the northeastern plain area and adjacent mountains in Yilan, Taiwan, when a synoptic‐scale northeasterly wind prevails under the active East Asian winter monsoon with stratocumulus cloud decks. A preliminary analysis indicated that a local‐scale convergence line appeared over the plain area, and the precipitation hotspot was located in the mountain region of southern Yilan, where turbulence features were apparent. The results inspire the arrangement of future field observations to explore mechanisms of heavily precipitating stratocumulus over complex topography.
Variations in the height of the boundary layer have a critical impact on the vertical transport of near-surface aerosols. Variations can affect the interactions between aerosols and clouds/fog by ...altering the scattering and absorption of solar radiation, significantly changing radiative forcing, convective precipitation, and regional climate. In this study, we simultaneously monitored air pollution and meteorological factors in a flat urban area (YunTech site, 50 m asl) and its peripheral mountainous region (MeiShan site, 980 m asl), analyzed the characteristics of pollutants under different atmospheric conditions, and explored the differences in the chemical reaction mechanisms of aerosols at various altitudes, aiming to clarify the evolution of the boundary layer in urban and suburban areas and its impact on the transport of pollutants. The results show that even without anthropogenic emissions, urban ground-level pollutants could be transported to peripheral mountainous areas through boundary layer height variations and local circulations, such as mountain-valley breezes. The PM2.5 concentration was higher at the urban site (average 31.14 ± 14.82μgm−3) and could be transported aloft by valley winds, leading to the gradual accumulation of daytime PM2.5 with an afternoon peak at the mountain site. Moreover, the nitrogen oxidation rate (NOR = NO3−/NO3− + NO2) exhibited clear site variations, the mountain site (average 0.41 ± 0.20) was higher than the urban site (average 0.19 ± 0.07), likely due to the atmospheric environment with thick clouds/fog and strong oxidation capacity in the mountain area. Our study has verified that aerosol characteristics, origins, formation pathways and transport mechanisms at the two measurement sites are significantly different under different conditions, which provides a theoretical basis for future air pollution prevention and regional climate research.
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•Simultaneous observations between the mid-low-altitude regions were conducted.•Boundary layer variations affect the transport between urban and mountainous regions.•Secondary aerosols formatted in mountains was an important feedback to urban areas.•These findings will help in air pollution prevention and regional climate research.
Recent studies suggested that Traditional Chinese Medicine could play a beneficial role in conventional cancer treatment. The aim of this retrospective cohort study was to investigate the effect of ...Chinese herbal medicine (CHM) combined with Western medicine on the survival of patients with colorectal cancer. A retrospective cohort study was conducted on patients with newly diagnosed colorectal cancer identified from the Dalin Tzu Chi Hospital Cancer Registry Database in 2004–2014. Combining with the medical records of the study hospital, patients were classified into CHM users and CHM nonusers. Kaplan–Meier analyses and Cox proportional hazards regression analyses were used to investigate the survival between CHM users and CHM nonusers. A total of 535 patients with colorectal cancer were included in the study with 147 of them were CHM users. The log-rank test for Kaplan–Meier survival curve revealed a statistically significant difference between the survival of CHM users and CHM nonusers (P=0.006). Results from multivariate Cox regression analysis showed that CHM use was significantly associated with better survival (adjusted hazard ratio = 0.54, 95% CI = 0.38 to 0.77). In addition, the CHM formulae Jia Wei Xiao Yao San, Zhi Bah Di Huang Wan, Ping Wei San, and Qui Pi Tang were significantly associated with better survival. In conclusion, findings from this retrospective cohort study indicated that integrated CHM and Western medicine could improve survival in patients with colorectal cancer. Additional research on integrating TCM with Western medicine to improve cancer survival is warranted.
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