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An environmentally benign and efficient method for the synthesis of unsymmetrical diquinoxalin-2(1H)-ones with potential axial chirality via inexpensive copper-catalyzed, low-toxicity, and stable PIFA oxidation, rarely assisted by PhSeSePh, regioselective homocoupling of quinoxalin-2(1H)-ones under mild conditions is developed. This practical scheme is compatible with a variety of functional groups and allows the preparation of functionalized unsymmetrical dimeric quinoxalin-2(1H)-ones from readily available and safe starting materials, providing new ideas for the sustainable development of methodological studies of quinoxalin-2(1H)-ones.

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The direct C-H multifunctionalization of quinoxalin-2(1H)-ones via multicomponent reactions has attracted considerable interest due to their diverse biological activities and chemical profile. This review will focus on recent achievements. It mainly covers reaction methods for the simultaneous introduction of C-C bonds and C-RF/C/O/N/Cl/S/D bonds into quinoxalin-2(1H)-ones and their reaction mechanisms. Meanwhile, future developments of multi-component reactions of quinoxalin-2(1H)-ones are envisaged, such as the simultaneous construction of C-C and C-B/SI/P/F/I/SE bonds through multi-component reactions; the construction of fused ring and macrocyclic compounds; asymmetric synthesis; green chemistry; bionic structures and other fields. The aim is to enrich the methods for the reaction of quinoxalin-2(1H)-ones at the C3 position, which have rich applications in materials chemistry and pharmaceutical pharmacology.

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The development of bifunctional ionic polymers as heterogeneous catalysts for effective, cocatalyst- and metal-free cycloaddition of carbon dioxide into cyclic carbonates has attracted increasing attention. However, facile fabrication of such polymers having high numbers of ionic active sites, suitable types of hydrogen bond donors (HBDs), and controlled spatial positions of dual active sites remains a challenging task. Herein, imidazolium-based ionic polymers with hydroxyl/carboxyl groups and high ionic density were facilely prepared by a one-pot quaternization reaction. Catalytic evaluation demonstrated that the presence of HBDs (hydroxyl or carboxyl) could enhance the catalytic activities of ionic polymers significantly toward the CO2 cycloaddition reaction. Among the prepared catalysts, carboxyl-functionalized ionic polymer (PIMBr-COOH) displayed the highest catalytic activity (94% yield) in the benchmark cycloaddition reaction of CO2 and epichlorohydrin, which was higher than hydroxyl-functionalized ionic polymer (PIMBr-OH, 76% yield), and far exceeded ionic polymer without HBDs groups (PIMBr, 54% yield). Furthermore, PIMBr-COOH demonstrated good recyclability and wide substrate tolerance. Under ambient CO2 pressure, a number of epoxides were smoothly cycloadded into cyclic carbonates. Additionally, density functional theory (DFT) calculation verified the formation of strong hydrogen bonds between epoxide and the HBDs of ionic polymers. Furthermore, a possible mechanism was proposed based on the synergistic effect between carboxyl and Br- functionalities. Thus, a facile, one-pot synthetic strategy for the construction of bifunctional ionic polymers was developed for CO2 fixation.

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<p><b>OBJECTIVE</b>To investigate the risk factors of prostate cancer in urban Qingdao and provide some theoretical evidence for the scientific prevention and treatment of the disease.</p><p><b>METHODS</b>We performed a hospital-based matched case-control study in Qingdao Municipal Hospital. The cases and controls were matched in age, gender, nationality and the place of residence. All the subjects were interviewed face to face in the hospital using a questionnaire, and the data analyzed by the conditional logistic regression method.</p><p><b>RESULTS</b>According to the 258 valid questionnaires collected, the prostate cancer risk was significantly higher in the cases with a family history of cancer than in those without (OR = 2.58), and so was it in the men with the first spermatorrhea at the age of < or = 15 years than in those at the age of > or = 18 years (OR = 2.27). A decreased risk of prostate cancer was found among the men with the first experience of sexual intercourse between 25 to 30 years of age (OR = 0.76). An increased risk was shown in those with sexual intercourses > or = 4 times per week before 35 years old (OR = 2.57), masturbations > or = 3 times per week (OR = 2.30) and a drinking history (alcohol > or = 150 g/d) of > or = 10 years (OR = 2.83).</p><p><b>CONCLUSION</b>Positive family history of cancer, earlier age of the first spermatorrhea, sexual intercourses > or = 4 times per week before 35 years old, frequent masturbations, and heavy drinking for more than 10 years are risk factors for prostate cancer.</p>

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<p><b>OBJECTIVE</b>To investigate the effect of tea polyphenols on the proliferation of human prostate cancer cells and its possible mechanism.</p><p><b>METHODS</b>We cultured androgen-independent prostate cancer DU145 cells in the medium with different concentrations (50, 100, 250 and 500 microg/ml) of tea polyphenols, and those in the normal medium as the control. After 48 hours of culture, we detected the survival rate of the cells by MTT assay and determined the expression of survivin by Western blot and quantitative RT-PCR.</p><p><b>RESULTS</b>At 48 hours, the survival rates of the prostate cancer DU145 cells were 0.97 +/- 0.12, 0.71 +/- 0.07, 0.20 +/- 0.03 and 0.08 +/- 0.01 in the 50, 100, 250 and 500 microg/ml tea polyphenols treatment groups, all significantly reduced as compared with the control group (P < 0.01) except that of the 50 microg/ml group (P = 0.42). Furthermore, the survival rate continued to decrease with the prolonging of time, dropping below 5% at 96 hours except in the 50 microg/ml group. The grey values of the survivin expression in the 100, 250 and 500 microg/ml tea polyphenols groups were 13 425 +/- 34, 2 017 +/- 24 and 1 274 +/- 22, respectively, at 48 hours, significantly lower than 15 075 +/- 48 in the control group (P < 0.01). Moreover, the content of survivin mRNA at 48 hours was markedly lower in the 50, 100, 250 and 500 microg/ml treatment groups (0.74 +/- 0.03, 0.64 +/- 0.02, 0.52 +/- 0.01 and 0.21 +/- 0.02) than in the control (P < 0.01).</p><p><b>CONCLUSION</b>Tea polyphenols can inhibit the proliferation of human prostate cancer DU145 cells, which may be associated with the decreased expression of the survivin gene.</p>

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