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Non-stoichiometric oxide and metal interfaces and reactions
We have employed a combination of experimental surface science techniques and density functional calculations to study the reduction of TiO2(110) surfaces through the doping with submonolayer transition metals. We concentrate on the role of Ti adatoms in self doping of rutile and contrast the behaviour to that of Cr. DFT+U calculations enable identification of probable adsorption structures and their spectroscopic characteristics. Adsorption of both metals leads to a broken symmetry and an asymmetric charge transfer localised around the defect site of a mixed localised/delocalised character. Charge transfer creates defect states with Ti 3d character in the band gap at similar to 1-eV binding energy. Cr adsorption, however, leads to a very large shift in the valence-band edge to higher binding energy and the creation of Cr 3d states at 2.8-eV binding energy. Low-temperature oxidation lifts the Ti-derived band-gap states and modifies the intensity of the Cr features, indicative of a change of oxidation state from Cr3+ to Cr4+. Higher temperature processing leads to a loss of Cr from the surface region, indicative of its substitution into the bulk
Litsea Species as Potential Antiviral Plant Sources
Litsea verticillata Hance (Lauraceae), a Chinese medicine used to treat swelling caused by injury or by snake bites, was the first plant identified by our National Institutes of Health (NIH)-funded International Cooperative Biodiversity Group (ICBG) project to exhibit anti-HIV activities. From this plant, we discovered a class of 8 novel litseane compounds, prototypic sesquite rpenes, all of which demonstrated anti-HIV activities. In subsequent studies, 26 additional compounds of different structural types were identified. During our continuing investigation of this plant species, we identified two new litseanes, litseaverticillols L and M, and a new sesquiterpene butenolide, litseasesquibutenolide. Litseaverticillols L and M were found to inhibit HIV-1 replication, with an IC50 value of 49.6μM. To further determine the antiviral properties of this plant, several relatively abundant isolates, including a litseane compound, two eudesmane sesquiterpenes and three lignans, were evaluated against an additional 21 viral targets. Lignans 8 and 9 were shown to be active against the Epstein-Barr Virus (EBV), with EC50 values of 22.0μM (SI=3.8) and 16.2μM (SI>6.2), respectively. Since many antiviral compounds have been discovered in L. verticillata, we further prepared 38 plant extracts made from the different plant parts of 9 additional Litsea species. These extracts were evaluated for their anti-HIV and cytotoxic activities, and four of the extracts, which ranged across three different species, displayed 97-100% inhibitory effects against HIV replication without showing cytotoxicity to a panel of human cell lines at a concentration of 20μg/mL
A Trial of Itraconazole or Amphotericin B for HIV-Associated Talaromycosis
BACKGROUND: Talaromyces marneffei infection is a major cause of human immunodeficiency virus (HIV)-related death in South and Southeast Asia. Guidelines recommend initial treatment with amphotericin B deoxycholate, but this drug has substantial side effects, a high cost, and limited availability. Itraconazole is available in oral form, is associated with fewer unacceptable side effects than amphotericin, and is widely used in place of amphotericin; however, clinical trials comparing these two treatments are lacking. METHODS: In this open-label, noninferiority trial, we randomly assigned 440 HIV-infected adults who had talaromycosis, confirmed by either microscopy or culture, to receive either intravenous amphotericin B deoxycholate (amphotericin) (219 patients), at a dose of 0.7 to 1.0 mg per kilogram of body weight per day, or itraconazole capsules (221 patients), at a dose of 600 mg per day for 3 days, followed by 400 mg per day, for 11 days; thereafter, all the patients received maintenance therapy with itraconazole. The primary outcome was all-cause mortality at week 2. Secondary outcomes included all-cause mortality at week 24, the time to clinical resolution of talaromycosis, early fungicidal activity, relapse of talaromycosis, development of the immune reconstitution inflammatory syndrome (IRIS), and the side-effect profile. RESULTS: The risk of death at week 2 was 6.5% in the amphotericin group and 7.4% in the itraconazole group (absolute risk difference, 0.9 percentage points; 95% confidence interval [CI], -3.9 to 5.6; P<0.001 for noninferiority); however, the risk of death at week 24 was 11.3% in the amphotericin group and 21.0% in the itraconazole group (absolute risk difference, 9.7 percentage points; 95% CI, 2.8 to 16.6; P=0.006). Treatment with amphotericin was associated with significantly faster clinical resolution and fungal clearance and significantly lower rates of relapse and IRIS than itraconazole. The patients who received amphotericin had significantly higher rates of infusion-related reactions, renal failure, hypokalemia, hypomagnesemia, and anemia than patients in the itraconazole group. CONCLUSIONS: Amphotericin was superior to itraconazole as initial treatment for talaromycosis with respect to 6-month mortality, clinical response, and fungicidal activity. (Funded by the Medical Research Council and others; IVAP Current Controlled Trials number, ISRCTN59144167 .)
Elevated CD8 T-cell counts and virological failure in HIV-infected patients after combination antiretroviral therapy
10.1097/MD.0000000000004570Medicine (United States)9532e457
Experimental and theoretical studies on the room-temperature ferromagnetism in new (1-x)Bi1/2Na1/2TiO3+xCoTiO3 solid solution materials
Plans for nationwide serosurveillance network in Vietnam
10.3201/eid2601.190641Emerging Infectious Diseases261E1-E
Ethnobotanical approach versus random approach in the search for new bioactive compounds: Support of a hypothesis
Renal dysfunction during tenofovir use in a regional cohort of HIV-infected individuals in the Asia-Pacific
10.1371/journal.pone.0161562PLoS ONE118e016156