Microplastics (MP) are ubiquitous within the environment, but the approaches to analysis of this contaminant are currently quite diverse, with a number of analytical methods available. The ...comparability of results is hindered as even for a single analytical method such as Fourier transform infrared spectroscopy (FT-IR) the different instruments currently available do not allow a harmonized analysis. To overcome this limitation, a new free of charge software tool, allowing the systematic identification of MP in the environment (siMPle) was developed. This software tool allows a rapid and harmonized analysis of MP across FT-IR systems from different manufacturers (Bruker Hyperion 3000, Agilent Cary 620/670, PerkinElmer Spotlight 400, and Thermo Fischer Scientific Nicolet iN10). Using the same database and the automated analysis pipeline in siMPle, MP were identified in samples that were analyzed with instruments with different detector systems as well as optical resolutions and the results discussed.
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NUK, OILJ, SAZU, UKNU, UL, UM, UPUK
The article explores the Legon School of International Relations (LSIR) which is the research, teaching, and academic programming of International Relations (IR) at the University of Ghana, Legon. ...The LSIR came out of attempts to decolonise knowledge production, dissemination, and academic programing in Ghana in early 1960s. The article shows that the LSIR is decolonial in theoretical perspective, grounded in southern epistemologies, relational in ontology, qualitative in methodology, practice-based, and it is equity-oriented. Although the LSIR scholarship as a package is distinctive, some of its ideas overlap with the work of several contemporary IR communities in the West. The article highlights implications of the LSIR story for the IR communities in the West and the value of paying close attention to the works of IR centres of scholarship in Africa.
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•Ir/Ce0.9M0.1O2 (M=Pr, Zr) catalysts showed more stable performance for MDR than Ir/CeO2.•The metal-support interaction and oxygen defect of Ir/Ce0.9M0.1O2 (M=Pr, Zr) are improved.•Ir ...sintering did not occur in the used catalysts.•Performance decay was associated with the carbon deposition and sintering of supports.
Methane dry reforming reaction was investigated over Ir catalysts supported on ceria-based solid solutions. The doping of Pr6O11 or ZrO2 into the matrix of ceria yields more oxygen defects, resulting in an improved redox property and enhanced metal-support interaction in Ir/Ce0.9M0.1O2 (M=Pr, Zr) catalysts compared to Ir/CeO2 catalyst. The Ir/Ce0.9M0.1O2 (M=Pr, Zr) catalysts showed higher catalytic performance and better stability than the Ir/CeO2 catalyst, which were assigned to positive effects of doping in maintaining Ir nanoparticles, stabilizing catalyst structure, and the strong metal-support interaction in reducing carbon deposition.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
HgCdTe (MCT) is a very versatile material system for infrared (IR) detection, suitable for high performance detection in a wide range of applications and spectral ranges. Indeed, the ability to ...tailor the cutoff frequency as close as possible to the needs makes it a perfect candidate for high performance detection. Moreover, the high quality material available today, grown either by molecular beam epitaxy or liquid phase epitaxy, allows for very low dark currents at low temperatures, suitable for low flux detection applications such as science imaging. MCT has also demonstrated robustness to the aggressive environment of space and faces, therefore, a large demand for space applications. A satellite may stare at the earth, in which case detection usually involves a lot of photons, called a high flux scenario. Alternatively, a satellite may stare at outer space for science purposes, in which case the detected photon number is very low, leading to low flux scenarios. This latter case induces very strong constraints onto the detector: low dark current, low noise, (very) large focal plane arrays. The classical structure used to fulfill those requirements are usually
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MCT photodiodes. This type of structure has been deeply investigated in our laboratory for different spectral bands, in collaboration with the CEA Astrophysics lab. However, another alternative may also be investigated with low excess noise: MCT
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avalanche photodiodes (APD). This paper reviews the latest achievements obtained on this matter at DEFIR (LETI and Sofradir common laboratory) from the short wave infrared (SWIR) band detection for classical astronomical needs, to long wave infrared (LWIR) band for exoplanet transit spectroscopy, up to very long wave infrared (VLWIR) bands. The different available diode architectures (
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, or even APDs) are reviewed, including different available ROIC architectures for low flux detection.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
•Ir(C^N)(C’^N’)(N’’^N’’’)-tris-heteroleptic Ir(III)-complex.•Ir(C^N)2(N’’^N’’’)-tris-heteroleptic Ir(III)-complex.•Geometrical isomerization.•Near-infrared polymer light-emitting diodes (NIR-PLEDs).
...Despite efficient NIR-OLEDs/PLEDs fabricated from Ir(C^N)2(O^O)/Ir(C^N)2(N^O)-bis-heteroleptic and few Ir(C^N)(C’^N’)(O^O)/Ir(C^N)(C’^N’)(N^O)-tris-heteroleptic iridium(III)-complexes, the problems to dissociation of N^O/O^O-ancillary units upon acid-hydrolysis or pyrolysis, together with geometrically isomeric complexity, have to be faced. Herein, a molecular design strategy to C1-symmetrical Ir(C^N)(C’^N’)(N’’^N’’’)-tris-heteroleptic Ir(III)-complex (HC^N = Hiqbt, HC’^N’ = Hppy and HN’’^N’’’ = Hftrpz) is developed. The improved stability of Ir(iqbt)(ppy)(ftrpz) (2) is arisen from the strong HN’’^N’’’-ligand-field strength as compared to the N^O/O^O-ancillary counterparts. Meanwhile, owing to the Hftrpz-induced asymmetry, two geometrical isomers (2a and 2b) of Ir(iqbt)(ppy)(ftrpz) are first isolated. Noticeably, using the two isomeric NIR-phosphors Ir(iqbt)(ppy)(ftrpz)-a/b (2a and 2b) as the dopants, their high-performance NIR-PLEDs than that with the Ir(iqbt)2(ftrpz) (1) counterpart, are realized. Especially the NIR-PLED-2b, exhibits both an attractively high efficiency (ηEQEmax = 5.94 %; λem = 692 nm) and almost negligible (< 5 %) efficiency roll-off. And thus, this finding engenders Ir(C^N)(C’^N’)(N’’^N’’’)-tris-heteroleptic Ir(III)-complexes a new platform to the realization of high-performance, low-cost, large-area and scalable NIR-PLEDs.
Display omitted Upon one-pot synthesis, two Ir(C^N)(C’^N’)(N’’^N’’’)-tris-heteroleptic geometrical isomers Ir(iqbt)(ppy)(ftrpz)-a/b (2a and 2b) and one Ir(C^N)2(N’’^N’’’)-bis-heteroleptic Ir(III)-complex Ir(iqbt)2(ftrpz) (1) were isolated, respectively. Moreover, using the two isomeric NIR-phosphors Ir(iqbt)(ppy)(ftrpz)-a/b (2a and 2b) as the dopants, their higher-performance NIR-PLEDs than that with the Ir(iqbt)2(ftrpz) (1) counterpart, are realized. Especially the NIR-PLED-2b, endowing both an attractively high efficiency (ηEQEmax = 5.94 %; λem = 692 nm) and almost negligible (< 5 %) efficiency roll-off, engenders Ir(C^N)(C’^N’)(N’’^N’’’)-tris-heteroleptic Ir(III)-complexes a new platform to the realization of high-performance, low-cost, large-area and scalable NIR-PLEDs.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Background and aims: Insulin-like growth factor (IGF) I receptor (IGF-Ir) signalling is required for carcinogenicity and proliferation of many tumours but this pathway has not been studied in detail ...in gastric cancer. We have previously shown successful therapy for colorectal, pancreatic, and lung cancer using recombinant adenoviruses expressing dominant negative (dn) IGF-Ir. In this study, we sought to better dissect the role of IGF-Ir on progression of gastric cancer and determine whether IGF-Ir targeted adenoviruses represent potentially effective therapeutics for human gastric cancer. Methods: We assessed the effect of IGF-Ir ligands on proliferation and survival in gastric cancer cells in culture. Then, recombinant adenoviruses expressing truncated IGF-Ir (482 and 950 amino acids long, IGF-Ir/dn) that function as dn inhibitors were studied in the treatment of human gastric cancer xenografts. We characterised the effects of IGF-Ir/dn on signalling blockade, growth, apoptosis induction, and in vivo therapeutic efficacy. Results: IGF-Ir signalling promoted tumour growth and survival in gastric cancer. IGF-Ir/dn expression suppressed tumorigenicity both in vitro and in vivo and upregulated stressor induced apoptosis. IGF-Ir/dn blocked Akt-1 activation induced by IGF-I, IGF-II, and des(1-3)IGF-I, but not by insulin. IGF-Ir/dn expression increased radiation and chemotherapy induced apoptosis and the combination of IGF-Ir/dn and chemotherapy was very effective against tumours in mice. In an intraperitoneal model, IGF-Ir/dn therapy also suppressed peritoneal dissemination. Conclusions: IGF-Ir is involved in the regulation of survival and cell growth in human gastric cancer and may be a good molecular therapeutic target. Adenovirus-IGF-Ir/dn may thus have therapeutic use in gastric cancer.
•Functional properties of polysaccharides depend on their structural features.•IR spectroscopy is widely used in polysaccharide structural analysis.•Classical applications of IR spectroscopy in ...polysaccharide are reviewed.•IR integrating techniques can considerably expand its application scope.
Polysaccharides are important biomacromolecules with numerous beneficial functions and a wide range of industrial applications. Functions and properties of polysaccharides are closely related to their structural features. Infrared (IR) spectroscopy is a well-established technique which has been widely applied in polysaccharide structural analysis. In this paper, the principle of IR and interpretation of polysaccharide IR spectrum are briefly introduced. Classical applications of IR spectroscopy in polysaccharide structural elucidation are reviewed from qualitative and quantitative aspects. Some advanced IR techniques including integrating with mass spectrometry (MS), microscopy and computational chemistry are introduced and their applications are emphasized. These emerging techniques can considerably expand application scope of IR, thus exert a more important effect on carbohydrate characterization. Overall, this review seeks to provide a comprehensive insight to applications of IR spectroscopy in polysaccharide structural analysis and highlights the importance of advanced IR-integrating techniques.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Magnetic hyperthermia therapy (MHT) and chemodynamic therapy (CDT) are non-invasive in situ treatments without depth limitations and with minimum adverse effects on surrounding healthy tissue. We ...herein report a mitochondria-targeting magnetothermogenic nanozyme (Ir@MnFe2O4 NPs) for highly efficient cancer therapy. An iridium(III) complex (Ir) acts as a mitochondria-targeting agent on the surface of MnFe2O4 NPs. On exposure to an alternating magnetic field (AMF), the Ir@MnFe2O4 NPs induce a localized increase in temperature causing mitochondrial damage (MHT effect). Meanwhile glutathione (GSH) reduces Fe(III) to Fe(II) on the NPs surface, which in turn catalyzes the conversion of H2O2 to cytotoxic •OH (CDT effect). The depletion of GSH (a •OH scavenger) increases CDT efficacy, while the localized increase in temperature increases the rate of conversion of both Fe(III) to Fe(II) and H2O2 to •OH further enhancing the CDT effect. In addition, the disruption of cellular redox homeostasis due to CDT, leads to greater sensitivity of the cell towards MHT. This nanoplatform integrates these excellent therapeutic properties, with two-photon microscopy (TPM) (demonstrated in vitro) and magnetic resonance imaging (MRI) (demonstrated in vivo) to enable the precise and effective treatment of cancer.
Mitochondria-targeting nanoparticles (Ir@MnFe2O4 NPs) have been synthesized for cancer treatment. The nanoparticles combine magnetic-hyperthermal therapy (MHT) with chemodynamic therapy (CDT), generating localized temperature increase and cytotoxic •OH under an alternating magnetic field. The NPs can also be used for two-photon microscopy and MRI. This nanoplatform blends MHT, CDT and imaging for the potent and precise therapy of cancer. Display omitted
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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