[n]Cycloparaphenylene-Pillar[5]arene Bismacrocycles: Their Circularly Polarized Luminescence and Multiple Guest Recognition Properties.

Both pillar[n]arenes (P[n]As) and [n]cycloparaphenylenes ([n]CPPs) play an important role in supramolecular chemistry. Herein, we report the precise synthesis of two multifunctional bismacrocycles [n]CPP-P[5]A by integrating P[5]A into the [n]CPP backbone. The photoluminescence quantum yield (ΦF ) of the bismacrocycles was found to show a dramatic increase relative to the corresponding [n]CPPs. The chiral enantiomers (pR)/(pS)-[8]CPP-P[5]A were successfully isolated by chiral HPLC, and showed promising properties of circularly polarized luminescence (glum ≈0.02). In addition, [n]CPP-P[5]A bismacrocycles are capable of binding pyridinium salts and fullerene derivatives with high affinity and specificity within the two distinct cavities. Transient absorption studies showed that photo-induced electron transfer occurs in [10]CPP-P[5]A⊃C60 complex. Our results suggest that [n]CPP-P[5]A are potentially useful in CPL-active materials, multiple guest recognition and supramolecular polymer preparation.

Synthesis of 1,4-Dihydropyridines and Related Heterocycles by Iodine-Mediated Annulation Reactions of N-Cyclopropyl Enamines.

The annulation of N-cyclopropyl enamines to produce 1,4-dihydropyridine (1,4-DHP) derivatives is described. In the presence of molecular iodine (I2), an N-cyclopropyl enamine substrate undergoes iodination, opening of the cyclopropyl ring, and annulation with a second molecule of the substrate to form the 1,4-DHP product. This reaction is amenable to gram-scale operations under mild reaction conditions with no transition metals being required. Further transformations of the 1,4-DHPs leads to related pyridine and bicyclic frameworks.

Synthesis of Functionalized Imidazolium Salts via Iodine-Mediated Annulations of Enamines.

A novel annulation reaction of two enamine molecules with iodine under basic conditions to form 4-functionalized imidazolium salts has been established. In this reaction, iodine acts as both an iodinating reagent and a Lewis acid catalyst. Features of this synthetic method include facilitative preparation of substrates, no use of transition metals, mild reaction conditions, simplicity of operation, and gram scale synthesis.

Metal-Free [2 + 2 + 2] Cycloaddition of Ynamides with Nitriles to Construct 2,4-Diaminopyridines.

We present a metal-free [2 + 2 + 2] cycloaddition of ynamides with nitriles that enables highly efficient access to 2,4-diaminopyridines. This catalytic protocol is more environmentally friendly and allows for a concomitant construction of C-C and C-N bonds between ynamides and nitriles, exhibiting excellent chemoselectivity, regioselectivity, and wide functional groups tolerance.

c-axis preferential orientation of hydroxyapatite accounts for the high wear resistance of the teeth of black carp (Mylopharyngodon piceus).

Biological armors such as mollusk shells have long been recognized and studied for their values in inspiring novel designs of engineering materials with higher toughness and strength. However, no material is invincible and biological armors also have their rivals. In this paper, our attention is focused on the teeth of black carp (Mylopharyngodon piceus) which is a predator of shelled mollusks like snails and mussels. Nanoscratching test on the enameloid, the outermost layer of the teeth, indicates that the natural occlusal surface (OS) has much higher wear resistance compared to the other sections. Subsequent X-ray diffraction analysis reveals that the hydroxyapatite (HAp) crystallites in the vicinity of OS possess c-axis preferential orientation. The superior wear resistance of black carp teeth is attributed to the c-axis preferential orientation of HAp near the OS since the (001) surface of HAp crystal, which is perpendicular to the c-axis, exhibits much better wear resistance compared to the other surfaces as demonstrated by the molecular dynamics simulation. Our results not only shed light on the origin of the good wear resistance exhibited by the black carp teeth but are of great value to the design of engineering materials with better abrasion resistance.

Incidence and mortality of liver cancer in China, 2010.

Liver cancer is a common malignant tumor in China and a major health concern. We aimed to estimate the liver cancer incidence and mortality in China in 2010 using liver cancer data from some Chinese cancer registries and provide reference for liver cancer prevention and treatment. We collected and evaluated the incidence and mortality data of liver cancer in 2010 from 145 cancer registries, which were included in the 2013 Chinese Cancer Registry Annual Report, calculated crude, standardized, and truncated incidences and mortalities, and estimated new liver cancer cases and deaths from liver cancer throughout China and in different regions in 2010 from Chinese practical population. The estimates of new liver cancer cases and deaths were 358,840 and 312,432, respectively, in China in 2010. The crude incidence, age-standardized rate by Chinese standard population (ASR China), and age-standardized rate by world standard population (ASR world) were 27.29/100,000, 21.35/100,000, and 20.87/100,000, respectively; the crude, ASR China, and ASR world mortalities were 23.76/100,000, 18.43/100,000, and 18.04/100,000, respectively. The incidence and mortality were the highest in western regions, higher in rural areas than in urban areas, and higher in males than in females. The age-specific incidence and mortality of liver cancer showed a rapid increase from age 30 and peaked at age 80-84 or 85+. Our results indicated that the 2010 incidence and mortality of liver cancer in China, especially in undeveloped rural areas and western regions, were among high levels worldwide. The strategy for liver cancer prevention and treatment should be strengthened.

Incidence and mortality of liver cancer in China, 2010 / 癌症

Liver cancer is a common malignant tumor in China and a major health concern. We aimed to estimate the liver cancer incidence and mortality in China in 2010 using liver cancer data from some Chinese cancer registries and provide reference for liver cancer prevention and treatment. We collected and evaluated the incidence and mortality data of liver cancer in 2010 from 145 cancer registries, which were included in the 2013 Chinese Cancer Registry Annual Report, calculated crude, standardized, and truncated incidences and mortalities, and estimated new liver cancer cases and deaths from liver cancer throughout China and in different regions in 2010 from Chinese practical population. The estimates of new liver cancer cases and deaths were 358,840 and 312,432, respectively, in China in 2010. The crude incidence, age-standardized rate by Chinese standard population (ASR China), and age-standardized rate by world standard population (ASR world) were 27.29/100,000, 21.35/100,000, and 20.87/100,000, respectively; the crude, ASR China, and ASR world mortalities were 23.76/100,000, 18.43/100,000, and 18.04/100,000, respectively. The incidence and mortality were the highest in western regions, higher in rural areas than in urban areas, and higher in males than in females. The age-specific incidence and mortality of liver cancer showed a rapid increase from age 30 and peaked at age 80-84 or 85+. Our results indicated that the 2010 incidence and mortality of liver cancer in China, especially in undeveloped rural areas and western regions, were among high levels worldwide. The strategy for liver cancer prevention and treatment should be strengthened.

Expression and localization of Wolfram syndrome 1 gene in the developing rat pancreas.

AIM: To investigate the expression and function of Wolfram syndrome 1 gene (WFS1) during the development of normal pancreas. METHODS: Pancreas from Sprague-Dawley rat fetuses, embryos, young and adult animals were used in this study. Expression levels of WFS1 in pancreas of different development stages were detected by reverse transcription-polymerase chain reation (RT-PCR) and Western blotting. To identify the cell location of WFS1 in the developing rat pancreas, double-immunofluorescent staining was performed using antibodies to specific cell markers and WFS1, respectively. RESULTS: Compared to E15.5, the highest level of WFS1 mRNA was detected at E18.5, the level of WFS1 mRNA in E15.5 and P0 was less, and at a lowest at adult (P < 0.05 vs P0 and adult), respectively. Compare to E15.5, the highest level of WFS1 was at P14 and lowest at P21 (P < 0.05 vs P14 and P21), respectively. The WFS1 positive staining is expressed in the normal developing rat pancreas mainly in the islet beta-cells and mesenchyme at each stage tested. CONCLUSION: These results indicate that WFS1 may be involved in some aspects of pancreatic development and further research on WFS1 may provide new evidences to prove the interactions between mesenchyma and epithelia at the same time.