Phosphorus-doped double-layered graphene field-effect transistors (PDGFETs) show much stronger air-stable n-type behavior than nitrogen-doped double-layered graphene FETs (NDGFETs), even under an oxygen atmosphere, due to strong nucleophilicity, which may lead to real applications for air-stable n-type graphene channels.

No abstract

A new chemical dual-functional reducing agent, thiophene, was used to produce high-quality reduced graphene oxide (rGO) as a result of a chemical reduction of graphene oxide (GO) and the healing of rGO. Thiophene reduced GO by donation of electrons with acceptance of oxygen while it was converted into an intermediate oxidised polymerised thiophene that was eventually transformed into polyhydrocarbon by loss of sulphur atoms. Surprisingly, the polyhydrocarbon template helped to produce good-quality rGO C (chemically reduced) and high-quality rGO CT after thermal treatment. The resulting rGO CT nanosheets did not contain any nitrogen or sulphur impurities, were highly deoxygenated and showed a healing effect. Thus the electrical properties of the as-prepared rGO CT were superior to those of conventional hydrazine-produced rGO that require harsh reaction conditions. Our novel dual reduction and healing method with thiophene could potentially save energy and facilitate the commercial mass production of high-quality graphene.G raphene has attracted great interest because of its unique physical properties 1 arising from its rigid twodimensional (2D) structure, and its potential applications in nanoelectronics 2 , energy storage materials 3 , polymer composite materials 4 and sensing 5 . Mechanical exfoliation is one of the successful approaches that have been developed for the preparation of high-quality graphene sheets suitable for fundamental studies, but large-scale production of such pure graphene sheets remains unfeasible. Instead, chemical graphitisation from graphene oxide (GO) to reduced graphene oxide (rGO) is generally used for mass production of graphene [6][7][8][9][10] . Numerous reducing chemicals such as hydrazine 11 , NaBH 4 12 , hydriodic acid (HI) 13 , NaOH 14 , ascorbic acid 15 and glucose 16 have been used to convert GO to rGO. However, all of these reducing agents produce imperfect rGOs containing a high level of defects or disorders. Recently, Amarnath et al. introduced a pyrrole as a new chemical reducing agent in this process, but the C/O ratio showed that GO was not fully reduced and the resulting rGO contained high nitrogen contamination emanating from the nitrogen source 17 . Kaminska et al. also introduced reduction and functionalization of graphene oxide using tetrathiafulvalene 18 . Despite the urgent need for production of a defect-free rGO, there have not been any reports of chemical healing of the defects of heteroatom-free rGO in the reduction process of GO to rGO. In addition, the development of novel reduction methods that are environmentally friendly, mild, and cost effective ways remains a challenge for mass production of high-quality rGOs by chemical healing.In this study, we introduce a new dual-functional reducing agent, thiophene (T) which has lower reactivity than pyrrole 17 and produces high-quality, heteroatom-free rGOs by chemical healing reduction of GO. Thiophene can be used to reduce as-prepared GO by dual-functional electron donation and oxygen consumption. It is also ...

Summary:Pro-inflammatory (IL-6, TNF␣ and IL-8) and antiinflammatory (IL-10) cytokines were determined in weekly samples from 52 patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT). IL-6 increased immediately after transplant peaking at week +3, but IL-8 concentrations were elevated only during week +1. After a slight decrease in week +1, TNF-␣ significantly increased from week +2 and peaked at week +3, whereas, IL-10 values started to rise in week +2 and peaked during week +4. IL-6 and TNF-␣ were positively correlated from week +2 to week +4, and IL-6 levels at week +1 were related with fever and severe stomatitis. Serum levels of IL-6 at week +1 and IL-10 at week +4 were significantly higher in patients with early transplant-related complications, such as fever, severe stomatitis or acute GVHD у overall grade II than in those without the complications. We conclude that a high serum IL-6 level at week +1 may be an early predictor of transplant-related complications and that it seems to trigger pro-and anti-inflammatory cytokine release. Kinetic patterns of IL-6 and IL-10 were more exaggerated in those with complications after HSCT. Bone Marrow Transplantation (2001) 28, 935-940.