A Sequence of Phase Transformations and Phases in NiCoFeCrGa High Entropy Alloy

The present investigation is directed to phase transitions in the equimolar NiCoFeCrGa high entropy alloy, which is a mixture of face-centered cubic (FCC) and body-centered cubic (BCC) crystalline phases. The microstructure of the samples was investigated by using scanning electron microscopy (SEM), time-of-flight secondary ion mass spectroscopy (TOF-SIMS), transmission electron microscopy-based energy-dispersive spectroscopy (EDS) and electron energy loss spectroscopy (EELS), as well as X-ray diffraction (XRD) measurements. Based on the phases observed in different temperature ranges, a sequence of the phase transitions can be established, showing that in a realistic process, when freely cooling the sample with the furnace from high to room temperature, a microstructure having spinodal-like decomposition can also be expected. The elemental mapping and magnetic behaviors of this decomposed structure are also studied.

Week 48 Resistance Analyses of the Once-Daily, Single-Tablet Regimen Darunavir/Cobicistat/Emtricitabine/Tenofovir Alafenamide (D/C/F/TAF) in Adults Living with HIV-1 from the Phase III Randomized AMBER and EMERALD Trials

Darunavir/cobicistat/emtricitabine/tenofovir alafenamide (D/C/F/TAF) 800/150/200/10 mg is being investigated in two Phase III trials, AMBER (NCT02431247; treatment-naive adults) and EMERALD (NCT02269917; treatment-experienced, virologically suppressed adults). Week 48 AMBER and EMERALD resistance analyses are presented. Postbaseline samples for genotyping/phenotyping were analyzed from protocol-defined virologic failures (PDVFs) with viral load (VL) ≥400 copies/mL at failure/later time points. Post hoc analyses were deep sequencing in AMBER, and HIV-1 proviral DNA from baseline samples (VL <50 copies/mL) in EMERALD. Through week 48 across both studies, no darunavir, primary PI, or tenofovir resistance-associated mutations (RAMs) were observed in HIV-1 viruses of 1,125 participants receiving D/C/F/TAF or 629 receiving boosted darunavir plus emtricitabine/tenofovir-disoproxil-fumarate. In AMBER, the nucleos(t)ide analog reverse transcriptase inhibitor (N(t)RTI) RAM M184I/V was identified in HIV-1 of one participant during D/C/F/TAF treatment. M184V was detected pretreatment as a minority variant (9%). In EMERALD, in participants with prior VF and genoarchive data (N = 140; 98 D/C/F/TAF and 42 control), 4% had viruses with darunavir RAMs, 38% with emtricitabine RAMs, mainly at position 184 (41% not fully susceptible to emtricitabine), 4% with tenofovir RAMs, and 21% ≥ 3 thymidine analog-associated mutations (24% not fully susceptible to tenofovir) detected at screening. All achieved VL <50 copies/mL at week 48 or prior discontinuation. D/C/F/TAF has a high genetic barrier to resistance; no darunavir, primary PI, or tenofovir RAMs were observed through 48 weeks in AMBER and EMERALD. Only one postbaseline M184I/V RAM was observed in HIV-1 of an AMBER participant. In EMERALD, baseline archived RAMs to darunavir, emtricitabine, and tenofovir in participants with prior VF did not preclude virologic response.

Excitation energy trapping and dissipation by Ni-substituted bacteriochlorophyll a in reconstituted LH1 complexes from Rhodospirillum rubrum

Bacteriochlorophyll a with Ni(2+) replacing the central Mg(2+) ion was used as an ultrafast excitation energy dissipation center in reconstituted bacterial LH1 complexes. B870, a carotenoid-less LH1 complex, and B880, an LH1 complex containing spheroidene, were obtained via reconstitution from the subunits isolated from chromatophores of Rhodospirillum rubrum . Ni-substituted bacteriochlorophyll a added to the reconstitution mixture partially substituted the native pigment in both forms of LH1. The excited-state dynamics of the reconstituted LH1 complexes were probed by femtosecond pump-probe transient absorption spectroscopy in the visible and near-infrared spectral region. Spheroidene-binding B880 containing no excitation dissipation centers displayed complex dynamics in the time range of 0.1-10 ps, reflecting internal conversion and intersystem crossing in the carotenoid, exciton relaxation in BChl complement, and energy transfer from carotenoid to the latter. In B870, some aggregation-induced excitation energy quenching was present. The binding of Ni-BChl a to both B870 and B880 resulted in strong quenching of the excited states with main deexcitation lifetime of ca. 2 ps. The LH1 excited-state lifetime could be modeled with an intrinsic decay time constant in Ni-substituted bacteriochlorophyll a of 160 fs. The presence of carotenoid in LH1 did not influence the kinetics of energy trapping by Ni-BChl unless the carotenoid was directly excited, in which case the kinetics was limited by a slower carotenoid S1 to bacteriochlorophyll energy transfer.

Providers' lack of knowledge about herpes zoster in HIV-infected patients is among barriers to herpes zoster vaccination

Identification of perceptions about herpes zoster (HZ) disease, vaccine effectiveness and safety, and vaccine recommendations may impact immunization practices of physicians for HIV-infected patients. A survey was used to quantify knowledge of HZ as well as determine physician immunization perceptions and practices. There were 272/1700 respondents (16%). Correct answers for the incidence of varicella zoster virus (VZV) infection in adults and incidence of HZ in HIV-infected patients were recorded by 14% and 10% of providers, respectively. Providers reported poor knowledge of the incidence of disease recurrence in HIV-infected patients (41% correct), potency of HZ vaccine (47.5% correct) and mechanism of protection against reactivation of VZV (66% correct). Most (88%) agreed that HZ was a serious disease, and 73% believed that the burden of disease made vaccination important. A majority (75%) did not vaccinate HIV patients with HZ vaccine regardless of antiretroviral therapy status. Barriers to administration included safety concerns, concern that vaccine would not prevent HZ, risk of HZ dissemination, reimbursement issues and lack of Infectious Diseases Society of America (IDSA) guidelines. Only 38% of providers agreed that CDC guidelines were clear and 50% believed that clinical trials were needed prior to use of HZ vaccine in HIV-infected patients. Education about HZ is needed among HIV providers. Providers perceived vaccination as important, but data on vaccine safety and clear guidance from the CDC on this issue are lacking.

Biomonitoring of airborne inorganic and organic pollutants by means of pine tree barks. I. Temporal and spatial variations

Scots pine (Pinus sylvestris L.) bark samples were collected at two field sites (Neuglobsow, Rösa) and in different years between 1987 and 1996 in the east of Germany. The barks were analyzed with respect to the following inorganic and organic substances: Al, As, B, Ca, Cd, Ce, Cr, Cu, Fe, Hg, Mo, NH4+, Ni, NO3-, PO4(3)-, Pb, Sr, SO4(2)-, Ti, V, W, Zr, Zn, benzo[a]pyrene, fluoranthene, pyrene, alpha-hexachlorocyclohexane (alpha-HCH) and dichlorodiphenyltrichloroethane (DDT). In addition to bark samples from the site Rösa, 53 test sites were investigated in the Nature Park Dübener Heide. Here, the analysis of the barks aimed at discovering spatial patterns of the above-mentioned substances. Since 1991, most of the determined substances (e.g. sulfate, nitrate, calcium, lead, benzo[a]pyrene, alpha-HCH) show decreased concentration values in bark samples from both sites. Temporal variations reflect substantial infra-structural changes in eastern Germany, especially at Rösa and in the industrial region around the cities Leipzig, Halle, and Bitterfeld. Moreover, nitrate concentrations in barks are increasing since 1995. The trend can be explained with increased nitrogen emissions from motor traffic and livestock farms. Spatial patterns of sulphate and ammonia reflect inputs from power plants and agriculture in pine stands of the Nature Park Dübener Heide. The results show that barks of pine trees can be used as biomonitoring tools to indicate and characterize depositions of airborne organic and inorganic pollutants.

Bacteriorhodopsin's intramolecular proton-release pathway consists of a hydrogen-bonded network

In its proton-pumping photocycle, bacteriorhodopsin releases a proton to the extracellular surface at pH 7 in the transition from intermediate L to intermediate M. The proton-release group, named XH, was assigned in low-temperature FT-IR studies to a single residue, E204 [Brown, L. S., Sasaki, J., Kandori, H., Maeda, A., Needleman, R. , and Lanyi, J. K. (1995) J. Biol. Chem. 270, 27122-27126]. The time-resolved room-temperature step-scan FT-IR photocycle studies on wild-type and E204Q-, and E204D-mutated bacteriorhodopsin, which we present here, show in contrast that the FT-IR data give no evidence for deprotonation of E204 in the L-to-M transition. Therefore, it is unlikely that E204 represents XH. On the other hand, IR continuum absorbance changes indicate intramolecular proton transfer via an H-bonded network to the surface of the protein. It appears that this H-bonded network is spanned between the Schiff base and the protein surface. The network consists at least partly of internally bound water molecules and is stabilized by E204 and R82. Other not yet identified groups may also contribute. At pH 5, the intramolecular proton transfer to the surface of the protein seems not to be disturbed. The proton seems to be buffered at the surface and later in the photocycle released into the bulk during BR recovery. Intramolecular proton transfer via a complex H-bonded network is proposed to be a general feature of proton transfer in proteins.

[Congenital arteriovenous fistula of the coronary arteries in adults: 12 personal cases, a review of the literature, discussion of treatment possibilities]

Between 1976 and 1988, we found in a series of 18,000 coronary angiographies, 12 cases with 15 arteriovenous fistulas of the coronary vessels (incidence of 0.7%). Clinical symptoms were atypical angina pectoris and dyspnea upon exertion. Three patients had a systolic-diastolic murmur. In six cases we found fistulas accidentally, in concurrence with another important cardiovascular disease; 10 fistulas were singular, two fistulas were bilateral. The course was in 10 cases to the pulmonary artery, in three cases to the right atrium, in one case to the right ventricle, and in one case to the superior vena cava. With the exception of one patient, shunt volume was minimal. There were two preoperative sudden deaths of patients with extended fistulas and supra-ventricular arrhythmias. Complications and delineations of management are discussed.