Search

After decades of supremacy of the Titanium:Sapphire technology, Ytterbium-based high-order harmonic sources are emerging as a promising alternative for experiments requiring high flux of ultrashort extreme ultraviolet (XUV) radiation. In this article we describe a versatile experimental setup delivering XUV photons in the 10–50 eV range. The use of cascaded high-order harmonic generation enables us to reach 1.9 mW of average power at 18 eV. Several spectral selection schemes are presented, to isolate a single high-harmonic or a group of them. In the perspective of circular dichroism experiments, we produce highly elliptical XUV radiation using resonant elliptical high-harmonic generation, and circularly polarized XUV by bichromatic bicircular high-harmonic generation. As an illustration of the capacities of the beamline, we focus the XUV beam in a coincidence electron–ion imaging spectrometer, where we measure the photoelectron momentum angular distributions of xenon monomers and dimers. [ABSTRACT FROM AUTHOR]

Background and Objectives Babesia spp. are tick-borne, intraerythrocytic protozoan parasites, several of which are transfusion-transmissible. Transfusion-transmitted babesiosis poses serious risk to a diverse patient population, including neonates, patients aged >50 years, the asplenic and the immunocompromised that are over-represented among transfusion recipients. Despite reports of B. microti and B. venatorum in People's Republic of China (PRC), no surveillance of blood donors for Babesia has previously been undertaken. We sought to determine the rates of B. microti seroreactivity in a sample of blood donors in the PRC. Materials and Methods A pilot serosurvey was conducted of community blood donors (n = 1000) who donated July-August 2016 at Mudanjiang Blood Center (Heilongjiang Province) using indirect fluorescent antibody testing for antibodies against B. microti. The slides were prepared using B. microti-infected hamster blood. Samples that were initially positive to a titre of 64 were subjected to repeat IFA testing. Final seroreactivity was based on repeat reactivity to =64. Results A total of 1000 individual donor samples were evaluated, comprising 888 whole blood and 112 platelet donations. Thirteen of 1000 (1.3%) donors were seroreactive for B. microti [8 (0.8%) and five (0.05%) at titres of 64 and 128, respectively]. Conclusion Our preliminary findings support the need for expanded Babesia surveillance in Chinese blood donors, replete with molecular evaluation, to evaluate the risk to the blood supply. [ABSTRACT FROM AUTHOR]

Stability and sorption of Metal–Organic Frameworks (MOFs) towards water are critical in many applications, and can a priori be modulated through the introduction of suitable organic functional groups on their backbone. We report here the preparation of a series of Zr(iv)-based MOFs functionalized with alkyl and perfluoroalkyl groups and their characterization by X-ray powder diffraction, multi-nuclei (1H, 13C, 19F) solid state nuclear magnetic resonance analyses, and nitrogen sorption measurements at 77 K. Their water sorption behavior was evaluated at 298 K and related to their physico-chemical features, highlighting both the effect of the confinement and the nature of the functional groups on the hydrophilic/hydrophobic balance. [ABSTRACT FROM AUTHOR]

A linear RF to IF downconversion and IF to RF upconversion mixers for 60-GHz transceivers were implemented in 0.13- \mu \textm SiGe technology. The mixers were implemented using a mixing core only topology for enhanced linearity, with no local oscillator (LO) buffers and a transformer-based matching network for IF frequencies. The downconversion mixer at full attenuation shows a minimum of 10-dBm IIP3 and maximum measured loss of 6.5 dB within the entire 57–66 GHz frequency band. Without attenuation, the conversion gain is above 4 dB, with better than 2-dBm IIP3 and a noise figure maximum value of 14 dB within the band. The transmit mixer exhibits less than 2.5-dB conversion loss, better than 7.5-dBm OIP3 with minimal temperature variations. For improved LO to RF isolation, separated dc bias control is used in the mixing devices providing over 46-dBc LO suppression within the band. The mixers occupy only 0.47 and 0.22 mm ^\mathrm \mathbf 2 consuming 56 mW for downconversion mixer with IF amplifier and 27 mW for upconversion mixer. [ABSTRACT FROM PUBLISHER]

Background and Objectives Serologic screening for the major transfusion transmissible viruses ( TTV) is critical to blood safety and has been widely implemented. However, actual performance as measured by proficiency testing has not been well studied in sub- Saharan Africa. Therefore, we conducted an external quality assessment of laboratories engaged in transfusion screening in the region. Materials and Methods Blinded test panels, each comprising 25 serum samples that were pedigreed for HIV, HBs Ag, HCV and negative status, were sent to participating laboratories. The panels were tested using the laboratories' routine donor screening methods and conditions. Sensitivity and specificity were calculated, and multivariable analysis was used to compare performance against mode of testing, country and infrastructure. Results A total of 12 African countries and 44 laboratories participated in the study. The mean (range) sensitivities for HIV, HBs Ag and HCV were 91·9% (14·3-100), 86·7% (42·9-100) and 90·1% (50-100), respectively. Mean specificities for HIV, HBs Ag and HCV were 97·7%, 97% and 99·5%, respectively. After adjusting for country and infrastructure, rapid tests had significantly lower sensitivity than enzyme immunoassays for both HBs Ag ( P < 0·0001) and HCV ( P < 0·05). Sensitivity also varied by country and selected infrastructure variables. Conclusion While specificity was high, sensitivity was more variable and deficient in a substantial number of testing laboratories. These findings underscore the importance of proficiency testing and quality control, particularly in Africa where TTV prevalence is high. [ABSTRACT FROM AUTHOR]

Introduction: Blood donor selection is important to ensure the safety of both donors and recipients. There is a paucity of data on reasons for blood donor deferral in Ivory Coast. The aim of this study was to identify the reasons for predonation deferral at a blood collection site at General Hospital, Yopougon Attié in Abidjan.Materials and Methods: The investigators conducted a retrospective audit of data pertaining to donor deferral for blood donors that presented to the general hospital of Yopugon Attié from January 1, 2006 to December 31, 2008.Results: A total of 10,694 prospective blood donors, presented over the study period, and 24,363 attempts to donate were registered. The majority were repeat blood donors (77.4%). A total of 2618 (10.8%) donors were deferred. The most frequent reason for deferral was a low hemoglobin level (42.5%), with females constituting the majority of those deferred. The second most frequent reason for deferral was a reported change of or new sexual partner (34.3%); male donors were predominant in this group. Additional reasons for deferral included short interdonation interval (4.6%) and reactivity for a screened biomarker (2.3%).Conclusion: Although the rates for permanent and temporary deferral rates are similar between the Ivory Coast and high-middle income countries, the causes and demographics differ. The reasons for exclusion are preventable through awareness and education of prospective blood donors. [ABSTRACT FROM AUTHOR]

A new mineral species, markascherite (IMA2010-051), ideally Cu3(MoO4)(OH) 4, has been found at Copper Creek, Pinal County, Arizona, U.S.A. The mineral is of secondary origin and is associated with brochantite, antlerite, lindgrenite, wulfenite, natrojarosite, and chalcanthite. Markascherite crystals are bladed (elongated along the b axis), up to 0.50 x 0.10 x 0.05 mm. The dominant forms are {001}, {100}, and {010}. Twinning is found with the twofold twin axis along [10̅1]. The mineral is green, transparent with green streak and vitreous luster. It is brittle and has a Mohs hardness of 3.5~4; cleavage is perfect on {100} and no parting was observed. The calculated density is 4.216 g/cm³. Optically, markascherite is biaxial (-), with nα > 1.8, nβ > 1.8, and nγ > 1.8. The dispersion is strong (r > v). It is insoluble in water, acetone, or hydrochloric acid. An electron microprobe analysis yielded an empirical formula Cu2.89 (Mo1.04O4 (OH)4. Markascherite, polymorphic with szenicsite, is monoclinic, with space group P21/m and unit-cell parameters a = 9.9904(6), b = 5.9934(4), c = 5.5255(4) Å, β = 97.428(4)°, and V = 328.04(4) ų. Its structure is composed of three nonequivalent, markedly distorted Cu2+(O,OH)6 octahedra and one MoO4 tetrahedron. The Cu1 and Cu2 octahedra share edges to form brucite-type layers parallel to (100), whereas the Cu3 octahedra share edges with one another to form rutile-type chains parallel to the b axis. These layers and chains alternate along [100] and are interlinked together by both MoO4 tetrahedra and hydrogen bonds. Topologically, the structure of markascherite exhibits a remarkable resemblance to that of deloryite, Cu4(UO2)(MoO4)2(OH)6, given the coupled substitution of [2Cu2+ + 2(OH-)]2+ for [(U6+ + □) + 2O2-]2+. The Raman spectra of markascherite are compared with those of two other copper molybdate minerals szenicsite and lindgrenite. [ABSTRACT FROM AUTHOR]