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In this manuscript, we describe the synthesis of low molar mass polycarbonate diols by acid cleavage of labile acetal linkages included in high molar mass poly(ether- co -carbonate- co -acetal) terpolymers. These copolymers were prepared by terpolymerization of propylene oxide (PO) with o-phthalaldehyde (OPA) and carbon dioxide (CO 2), using triethyl borane (TEB) as activator and an onium salt as initiator. The advantage of this strategy of synthesis of poly(propylene carbonate) diols (PPC-diols) lies in the minute amounts of TEB and initiator required. Moreover, OPA could be isolated through post-hydrolysis of the terpolymers and recycled for subsequent use. We also demonstrated that this strategy works for the synthesis of low molar mass poly(ethylene carbonate) diols (PEC-diols). The structural integrity of the terpolymers before and after acid treatment, the characterization of low molar mass PPC-diols, and recycling process of OPA were carried out by 1H NMR spectroscopy, gel permeation chromatography, and matrix-assisted laser desorption ionization time of flight (MALDI-TOF) MS. [ABSTRACT FROM AUTHOR]

This study demonstrates the successful use of CO 2 as versatile carbonation agent for the synthesis of 5-membered and 6-membered bicyclic glycocarbonates from methyl α- d -mannopyranoside (MDM) and methyl α- d -galactopyranoside (MDG). On the one hand, these two sugars were cyclized into 5-membered glycocarbonates by mere reaction of CO 2 with their hydroxyls either at cis-2,3 or cis-3,4 positions and without resorting to phosgene or its derivatives. The reactivity of the obtained 5-membered cyclic glycocarbonates were further tested with hexyl- and dodecyl amine. The self-assembling behavior of the formed alkyl glycosides in water was investigated and characterized by transmission electron microscope (TEM). On the other hand, secondary hydroxyls at 2- and 3- positions in MDM and MDG were first protected by a ketal group and by two ether, respectively before subjecting their respective 6-position hydroxyl to bromination. Their respective 6-bromo and 4-hydroxyl functions were subsequently reacted in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and CO 2 . The resulting 6-membered cyclic glycocarbonates were then polymerized using 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) or DBU as organocatalyst. All the synthesized 5- and 6-membered cyclic glycocarbonates and polyglycocarbonates were thoroughly characterized by FT-IR, 1 H, 13 C NMR and MALDI-ToF and Gel Permeation Chromatography (GPC). [ABSTRACT FROM AUTHOR]

Introduction The aim of this study was to determine the impact of hepatitis B virus (HBV) and/or hepatitis C virus (HCV) on primary liver cancer (PLC) in China north areas. Methods A total of 2172 histologically confirmed PLC patients attending the National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences during the period January 1, 2003 to December 31, 2014 were enrolled. Details of hepatitis B surface antigen (HBsAg), antibodies against HBV core antigen (anti-HBc), and antibodies against HCV (anti-HCV) status were recorded. Sequencing of the HBV PreS-S gene and the C/E1 and NS5B fragments of HCV was performed and the genotypes were analyzed for some of the patients with hepatocellular carcinoma (HCC). Results Among the 2172 histologically confirmed PLC cases, 1823 (83.9%) had HCC and 238 (11.0%) had intrahepatic cholangiocarcinoma (iCCA). Among HCC cases, HBV infection alone, indicated by HBsAg-neg/pos + anti-HBc-pos, was found in 1567 (86.0%) cases; of these, 18.2% (331/1823) were HBsAg-neg + anti-HBc-pos. Serum HBV-DNA was detectable in 70% of HBsAg-neg + anti-HBc-pos HCC cases. The dominant HBV genotype was HBV-C2 (94.4%). HCV infection alone, indicated by anti-HCV-pos, was found in 2.5% (46/1823) of cases; HCV-1b (72.1%) was the dominant genotype. HBV + HCV co-infection markers were found in 6.7% (122/1823) of cases. Only 88 (4.8%) cases had no HBV and no HCV markers. Among the 238 iCCA cases, 54 (22.7%) were HBsAg-pos + anti-HBc-pos; none was anti-HCV-pos alone. Conclusions HBV remains the major contributor to PLC in China north areas Individuals with occult HBV infection should not be ignored in liver cancer screening. [ABSTRACT FROM AUTHOR]

The Integrative Analysis of Lung Cancer Etiology and Risk (INTEGRAL) program is an NCI-funded initiative with an objective to develop tools to optimize low-dose CT (LDCT) lung cancer screening. Here, we describe the rationale and design for the Risk Biomarker and Nodule Malignancy projects within INTEGRAL. The overarching goal of these projects is to systematically investigate circulating protein markers to include on a panel for use (i) pre-LDCT, to identify people likely to benefit from screening, and (ii) post-LDCT, to differentiate benign versus malignant nodules. To identify informative proteins, the Risk Biomarker project measured 1161 proteins in a nested-case control study within 2 prospective cohorts (n = 252 lung cancer cases and 252 controls) and replicated associations for a subset of proteins in 4 cohorts (n = 479 cases and 479 controls). Eligible participants had a current or former history of smoking and cases were diagnosed up to 3 years following blood draw. The Nodule Malignancy project measured 1078 proteins among participants with a heavy smoking history within four LDCT screening studies (n = 425 cases diagnosed up to 5 years following blood draw, 430 benign-nodule controls, and 398 nodule-free controls). The INTEGRAL panel will enable absolute quantification of 21 proteins. We will evaluate its performance in the Risk Biomarker project using a case-cohort study including 14 cohorts (n = 1696 cases and 2926 subcohort representatives), and in the Nodule Malignancy project within five LDCT screening studies (n = 675 cases, 680 benign-nodule controls, and 648 nodule-free controls). Future progress to advance lung cancer early detection biomarkers will require carefully designed validation, translational, and comparative studies. [ABSTRACT FROM AUTHOR]

Sensibility to environmental concerns and the actual demand for polymeric materials free of any metal contaminants in most applications have directed research towards significant breakthroughs in organocatalytic polymerizations. The overarching challenge is to develop new and efficient organocatalysts for extending the scope and to improve the performance of organocatalytic polymerizations. Since 2016 commercially available alkyl boranes, especially triethyl borane (TEB), have been discovered as exceptional Lewis acids that served to generate ate complexes by combination with chain ends on the one hand and to activate epoxides on the other. This double role of boranes has received widespread attention especially in oxygenated polymer synthesis. Lewis pairs consisting of alkyl boranes combined with an onium salt or organic base has indeed demonstrated unprecedented versatility for (co)polymerizations of oxygenated monomers such as epoxides, oxetanes, cyclic esters and with CO 2 , COS, isocyanates, or cyclic anhydrides, producing a variety of oxygenated polymers. In this review, we take TEB-mediated polymerization systems as the main line of emerging area, summarize the progress comprehensively made to promote the rapid development of organocatalytic polymerizations of oxygenated polymers by these systems, and propose key challenges in organocatalytic synthesis in the future. [Display omitted] [ABSTRACT FROM AUTHOR]

Highlights: [•] Chelating polymer could be used to heavy metal sensing. [•] Formation of chelating polymer in situ is convenient by electrochemical method for heavy metal sensing. [•] Two-dimension chelating polymer with more functional groups and space, which probably are beneficial to mass transfer. [•] Iminodiacetic acid functional glycidyl methacrylate polymer brushes was prepared by electrochemical mediated atom transfer radical polymerization. [ABSTRACT FROM AUTHOR]

Ring-opening polymerization (ROP) of cyclic monomers is a prevalent and convenient method for the synthesis of well-defined polymers with initiators/catalysts that promote a nucleophilic or electrophilic attack on the monomers. Selective activation of functional groups or linkages of the monomer without those carried out in the polymer chains, especially at high conversion, is one of the challenges faced by ROP catalysts. H-bonding organocatalysts can offer precise selectivity for ROP in a wide range of monomers. The firstly reported neutral H-bonding organocatalysts are characterized by high selectivity but long reaction time and low reactivity. In contrast, ionic H-bonding organocatalysts, which have extensively developed over the last ten years, exhibit fast polymerization rates and high selectivity. Besides, some ionic H-bonding organocatalysts with good thermal stability and high reactivity can be used in a wide range of ROP temperatures (-60 °C to over 200 °C). Furthermore, ionic H-bonding organocatalysts comply with biosafety principles promoted by green chemistry. This review covers the mechanistic insights (monomer activation, initiator/chain-end activation, synergistic activation, and bifunctional activation) of ionic H-bonding organocatalytic ROP, as well as the strategies for monomer and initiator/chain-end activation. [Display omitted] [ABSTRACT FROM AUTHOR]