36 research outputs found
Oxidation resistance of graphene-coated Cu and Cu/Ni alloy
The ability to protect refined metals from reactive environments is vital to
many industrial and academic applications. Current solutions, however,
typically introduce several negative effects, including increased thickness and
changes in the metal physical properties. In this paper, we demonstrate for the
first time the ability of graphene films grown by chemical vapor deposition to
protect the surface of the metallic growth substrates of Cu and Cu/Ni alloy
from air oxidation. SEM, Raman spectroscopy, and XPS studies show that the
metal surface is well protected from oxidation even after heating at 200
\degree C in air for up to 4 hours. Our work further shows that graphene
provides effective resistance against hydrogen peroxide. This protection method
offers significant advantages and can be used on any metal that catalyzes
graphene growth
A secondary analysis of depression outcomes from a randomized controlled trial of adjunctive sertraline for HIV-associated cryptococcal meningitis.
Background: Depression is a risk factor for worse HIV outcomes in persons living with HIV/AIDS, including engagement-in-care, HIV medication adherence, and retention-in-care. Depression has a prevalence of more than three times as high as in the general population. Despite this, there are few randomized studies of antidepressants in HIV-infected Africans, including those with opportunistic infections. Methods: We enrolled 460 HIV-infected Ugandans with cryptococcal meningitis into a randomized clinical trial of adjunctive sertraline vs placebo (2015-2017). We defined depression using the Center for Epidemiologic Studies Depression Scale (CES-D) score of >15, and severe depression as >26 at one and three months after meningitis diagnosis and initiation of treatment. We evaluated the relationship between sertraline and depression, as well as associations with persistent depression, at three months. Results: At one- and three-months post meningitis diagnosis, 62% (108/174) and 44% (74/169) of all subjects had depression (CES>15), respectively. At three months, sertraline-treated subjects had consistent risk for depression as placebo-treated subjects but were significantly less likely to have severe depression (CES>26) (OR 0.335; 95%CI, 0.130-0.865). Of those with depression at one month, sertraline-treated subjects were less likely than placebo-treated subjects to be depressed at three months (p=0.05). Sertraline was the only factor we found significant in predicting persistent depression at three months among those with depression at one month. Conclusions: Depression is highly prevalent in HIV-infected persons who have survived cryptococcal meningitis. We found that sertraline is associated with a modest reduction in depression in those with depression at baseline and a significant decrease in severe depression
The effect of sertraline on depression and associations with persistent depression in survivors of HIV-related cryptococcal meningitis
Background: Depression is a risk factor for worse outcomes in persons living with HIV/AIDS and has a prevalence more than three times as high as in the general population. Despite this, there are few randomized studies of antidepressants in HIV-infected Africans.
Methods: We enrolled 460 HIV-infected Africans with cryptococcal meningitis into a randomized clinical trial of adjunctive sertraline vs placebo (2015-2017). We defined depression using depression using a Center for Epidemiologic Studies Depression Scale (CES-D) score of >15, and severe depression as >26 at one and three months after meningitis diagnosis and initiation of treatment.We evaluated the relationship between sertraline and depression, as well as associations with persistent depression, at three months.
Results: At one- and three-months post meningitis diagnosis, 62% (108/174) and 44% (74/169) of all subjects had depression (CES>15), respectively. At three months, sertraline-treated subjects had consistent risk for depression as placebo-treated subjects but were significantly less likely to have severe depression (CES>26) (OR 0.335; 95%CI, 0.130-0.865). Of those with depression at one month, sertraline-treated subjects were less likely than placebo-treated subjects to be depressed at three months (p=0.05). Sertraline was the only factor we found significant in predicting persistent depression at three months among those who had depression at one month.
Conclusions: Depression is highly prevalent in HIV-infected persons who have survived cryptococcal meningitis. We found that sertraline is associated with a modest reduction in depression in those with depression at baseline and a significant decrease in severe depression
BCRP expression does not result in resistance to STX140 in vivo, despite the increased expression of BCRP in A2780 cells in vitro after long-term STX140 exposure
The anti-proliferative and anti-angiogenic properties of the endogenous oestrogen metabolite, 2-methoxyoestradiol (2-MeOE2), are enhanced in a series of sulphamoylated derivatives of 2-MeOE2. To investigate possible mechanisms of resistance to these compounds, a cell line, A2780.140, eightfold less sensitive to the 3,17-O,O-bis-sulphamoylated derivative, STX140, was derived from the A2780 ovarian cancer cell line by dose escalation. Other cell lines tested did not develop STX140 resistance. RT–PCR and immunoblot analysis demonstrated that breast cancer resistance protein (BCRP) expression is dramatically increased in A2780.140 cells. The cells are cross-resistant to the most structurally similar bis-sulphamates, and to BCRP substrates, mitoxantrone and doxorubicin; but they remain sensitive to taxol, an MDR1 substrate, and to all other sulphamates tested. Sensitivity can be restored using a BCRP inhibitor, and this pattern of resistance is also seen in a BCRP-expressing MCF-7-derived cell line, MCF-7.MR. In mice bearing wild-type (wt) and BCRP-expressing tumours on either flank, both STX140 and mitoxantrone inhibited the growth of the MCF-7wt xenografts, but only STX140 inhibited growth of the MCF-7.MR tumours. In conclusion, STX140, a promising orally bioavailable anti-cancer agent in pre-clinical development, is highly efficacious in BCRP-expressing xenografts. This is despite an increase in BCRP expression in A2780 cells in vitro after chronic dosing with STX140