| 1. |
- Fellström, Bengt, 1947-, et al.
(författare)
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Strong Associations Between Early Tubular Damage and Urinary Cytokine, Chemokine, and Growth Factor Levels in Elderly Males and Females
- 2021
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Ingår i: Journal of Interferon and Cytokine Research. - : Mary Ann Liebert Inc. - 1079-9907 .- 1557-7465. ; 41:8, s. 283-290
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Tidskriftsartikel (refereegranskat)abstract
- Acute tubular necrosis is associated with high mortality rates and it is important to develop new biomarkers for tubular damage. The aim of this study was to investigate the effect of early tubular damage on a large number of urinary cytokines, chemokines, and growth factors. We selected 90 urine samples from the Prospective Investigation of the Vasculature in Uppsala Seniors Study (41 males and 49 females). The tubular damage markers cystatin C, neutrophil gelatinase-associated lipocalin (NGAL), and kidney injury molecule-1 (KIM-1) were analyzed in the urine samples and urinary cytokine levels were analyzed with 2 multiplex assays (proximity extension assay). After adjustment for sex, body mass index, estimated glomerular filtration rate, smoking, and multiplicity testing using the false discovery rate approach, there remained 26 cytokines that correlated significantly with urine cystatin C, 27 cytokines that correlated with NGAL, and 66 cytokines that correlated with KIM-1. Tubular damage shows a strong association with urinary cytokines, chemokines, and growth factors. Our findings indicate that multiplex proteomics could be a promising new approach to explore the complex effects of tubular damage.
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| 2. |
- Jeppson, Kjell, 1947
(författare)
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A Parameter Extraction Methodology for Graphene Field-Effect-Transistors
- 2023
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Ingår i: IEEE Transactions on Electron Devices. - 1557-9646 .- 0018-9383. ; 70:3, s. 1393-1400
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Tidskriftsartikel (refereegranskat)abstract
- Graphene field-effect transistors have now been around for more than a decade and their transfer characteristics extensively used for device characterization. Model parameters like low-field charge-carrier mobility and device contact/series resistance have often been the main interest. However, not until recently have the methods for device characterization themselves been the focus of research publications. In this paper, I report on a structured methodology for extracting and validating the extracted GFET model parameter values based on the physics of field-effect transistors in general and of graphene field-effect transistors in particular. During the extraction process the GFET resistance is divided into two parts, a constant part, and a gate-voltage-dependent part where the constant part often has been believed to represent the series/contact resistance. However, part of it depends on the channel length and contains first-order information about mobility degradation. Finally, I show that the main influence of the quantum capacitance can be captured by an equivalent oxide thickness replacing the insulator thickness.
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| 3. |
- Jeppson, Kjell, 1947, et al.
(författare)
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Mobility degradation and series resistance in graphene field-effect transistors
- 2021
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Ingår i: IEEE Transactions on Electron Devices. - 1557-9646 .- 0018-9383. ; 68:6, s. 3091-3095
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Tidskriftsartikel (refereegranskat)abstract
- Accurate device models and parameter extraction methods are of utmost importance for characterizing graphene field-effect transistors (GFETs) and for predicting their performance in circuit applications. For DC characterization, accurate extraction of mobility and series resistance is of particular concern. In this paper, we show how a first-order mobility degradation model can be used to separate information about mobility degradation and series resistance for a set of GFETs of different channel lengths. Data from a large set of top-gated GFETs based on chemical vapor deposited (CVD) graphene was analyzed to validate the proposed model and extraction procedures. For removing any uncertainties caused by observed device-to-device data variations due to the uneven quality of CVD graphene, the same methods were applied to a set of closely located bottom-gated GFETs found in literature. Those GFETs were designed for transfer length methods and fabricated on exfoliated graphene of homogenous quality. Similar mobility degradation behavior was observed for both sets of devices with the mobility being reduced to half for a voltage-induced charge carrier density of 1013 cm-2.
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| 4. |
- Asad, Muhammad, 1986, et al.
(författare)
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Enhanced high-frequency performance of top-gated graphene FETs due to substrate-induced improvements in charge carrier saturation velocity
- 2021
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Ingår i: IEEE Transactions on Electron Devices. - 1557-9646 .- 0018-9383. ; 68:2, s. 899-902
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Tidskriftsartikel (refereegranskat)abstract
- High-frequency performance of top-gated graphene field-effect transistors (GFETs) depends to a large extent on the saturation velocity of the charge car-riers, a velocity limited by inelastic scattering by surface optical phonons from the dielectrics surrounding the chan-nel. In this work, we show that by simply changing the graphene channel surrounding dielectric with a material having higher optical phonon energy, one could improve the transit frequency and maximum frequency of oscillation of GFETs. We fabricated GFETs on conventional SiO2/Si substrates by adding a thin Al2O3 interfacial buffer layer on top of SiO2/Si substrates, a material with about 30% higher optical phonon energy than that of SiO2, and compared performance with that of GFETs fabricated without adding the interfacial layer. From S-parameter measurements, a transit frequency and a maximum frequency of oscillation of 43 GHz and 46 GHz, respectively, were obtained for GFETs on Al2O3 with 0.5 µm gate length. These values are approximately 30% higher than those for state-of-the-art GFETs of the same gate length on SiO2. For relating the improvement of GFET high-frequency performance to improvements in the charge carrier saturation velocity, we used standard methods to extract the charge carrier veloc-ity from the channel transit time. A comparison between two sets of GFETs with and without the interfacial Al2O3 layer showed that the charge carrier saturation velocity had increased to 2·10^7 cm/s from 1.5·10^7 cm/s.
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| 5. |
- Bäck, Tom, 1964, et al.
(författare)
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A Novel Method for Real-Time Quantification of Radioligand Binding to Living Tumor Cells In Vitro
- 2024
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Ingår i: CANCER BIOTHERAPY AND RADIOPHARMACEUTICALS. - 1084-9785 .- 1557-8852. ; 39:1, s. 75-81
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Tidskriftsartikel (refereegranskat)abstract
- Background: Real-time quantification of radioligand binding to cells under in vivo-like conditions improves evaluation of clinical potential.Materials and Methods: SKOV-3 tumor cells were grown in a monolayer on a thin glass plate placed in a sealable shallow chamber with a continuous flow of 125I-trastuzumab solution. The time-dependent cell binding was measured using a NaI detector, and the binding parameters were derived by computational analysis.Results: The detection efficiency of 125I was 65 cps/kBq for radioligand bound to the cells. Experiments were analyzed to find the values of kon and koff. The resulting kon was 3.2-7.9 x 10(4) M-1 s(-1) and koff was 0.11-4.2 x 10(-5) s(-1).Conclusions: Radioligands can be rapidly evaluated by binding to living cells for selection and optimization of radioconjugates for diagnostic and therapeutic purposes.
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| 6. |
- Benhouria, Y., et al.
(författare)
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Examination of the Magnetic Properties of the Triangular Type Mixed spin-(1/2,1) Nanowire
- 2020
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Ingår i: Journal of Superconductivity and Novel Magnetism. - : SPRINGER. - 1557-1939 .- 1557-1947. ; 33:3, s. 817-824
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Tidskriftsartikel (refereegranskat)abstract
- In the presence of the crystal field D/J(Core) and the external magnetic field h/J(Core), using the Monte Carlo (MC) simulation based on the heat bath algorithm and the effective field theory (EFT), the triangular mixed spin nanowire model consisting of a spin-(1/2) core which is encircled by a spin-1 ferrimagnetic surface shell is studied. We have studied the special effects of the core surface and crystal field on the critical and compensation temperatures. Several properties, such as the magnetization, hysteresis behaviors, coercive field, and remanent magnetizations are studied. For the appropriate values of the system parameters, the compensation point and multi-loops are found PACS 05.50. + q; 77.80. Bh.
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| 7. |
- Eremets, Mikhail I., et al.
(författare)
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High-Temperature Superconductivity in Hydrides : Experimental Evidence and Details
- 2022
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Ingår i: Journal of Superconductivity and Novel Magnetism. - Berlin : Springer Nature. - 1557-1939 .- 1557-1947. ; 35:4, s. 965-977
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Tidskriftsartikel (refereegranskat)abstract
- Since the discovery of superconductivity at ~ 200 K in H3S, similar or higher transition temperatures, Tcs, have been reported for various hydrogen-rich compounds under ultra-high pressures. Superconductivity was experimentally proved by different methods, including electrical resistance, magnetic susceptibility, optical infrared, and nuclear resonant scattering measurements. The crystal structures of superconducting phases were determined by X-ray diffraction. Numerous electrical transport measurements demonstrate the typical behavior of a conventional phonon-mediated superconductor: zero resistance below Tc, shift of Tc to lower temperatures under external magnetic fields, and pronounced isotope effect. Remarkably, the results are in good agreement with the theoretical predictions, which describe superconductivity in hydrides within the framework of the conventional BCS theory. However, despite this acknowledgement, experimental evidences for the superconducting state in these compounds have recently been treated with criticism, which apparently stems from misunderstanding and misinterpretation of complicated experiments performed under very high pressures. Here, we describe in greater detail the experiments revealing high-temperature superconductivity in hydrides under high pressures. We show that the arguments against superconductivity can be either refuted or explained. The experiments on the high-temperature superconductivity in hydrides clearly contradict the theory of hole superconductivity and eliminate it.
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| 8. |
- Larsson, Sven, 1941
(författare)
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Conductivity Properties of Perovskite Nickelates and Cuprates Depend on the Oxidation States of the Metal Ions
- 2022
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Ingår i: Journal of Superconductivity and Novel Magnetism. - : Springer Science and Business Media LLC. - 1557-1947 .- 1557-1939. ; 35:11, s. 3101-3107
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Tidskriftsartikel (refereegranskat)abstract
- Superconducting nickelates in thin film perovskite structures, designed to be isostructural with the Cu(II) cuprates, have been discovered recently by Zhou et al. (Appl. Mater. Interfaces 10, 1463-1467, 1) and Li et al. (Nature 572, 624-627, 2) The strategies of both groups, to make nickelates as similar to the cuprates as possible by using planar NiO2 superlattice structures, proved successful. Ni(I) and Ni(III) are superconducting in superlattices, although TC is lower than in most Cu(II) cuprates. Here we find that a “3-oxidation states rule” applies to nickelate superlattices based on Ni(I) and Ni(III). It is predicted that the oxides of Ni(II), Cu(I), and Cu(III) cannot superconduct, because of violation of the 3-rule. This rule is derived here, along with other rules where the number of interacting oxidation states is decisive for the conduction properties of the metal ion. The Mott model is replaced by a free energy model.
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| 9. |
- Dubey, Isha
(författare)
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Remembering, forgetting and memorialising : 1947, 1971 and the state of memory studies in South Asia
- 2021
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Ingår i: India Review. - : Informa UK Limited. - 1473-6489 .- 1557-3036. ; 20:5, s. 510-539
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Tidskriftsartikel (refereegranskat)abstract
- The “cultural turn” in memory studies acknowledges that collective memory has a distinctive social aspect reflected in the manner in which it is communicated orally from one individual or generation to another. However, the point of departure is the emphasis on the need to account for the fact that memory is, in equal measure, shaped and mediated by tangible channels such as texts, images, objects, rituals, buildings and so on. The interactions and intersections between these two strands of approaching collective memory have been employed to write the most human and engaging histories of trauma and displacement–especially in the context of the Holocaust. This article takes this discussion forward by critically looking at the scope of the field of memory studies–with its largely Western frames of reference–to facilitate a deeper understanding of similar engagements and entanglements between communicative and culturally tangible forms of collective memory in South Asia. It looks at the ways in which the dominant discourse of nationalism is constructed and contested through the politics inherent in memorialization and memory in the South Asian context by comparing the partition of 1947 that resulted in the creation of Pakistan and the Liberation War of 1971 which gave birth to Bangladesh. Through a review of some important recent works of scholarship on the long, complex and intertwined afterlife of the partition of the Indian subcontinent in 1947 and the Bangladesh Liberation War of 1971, this article shows how the processes of the construction and contestation of a dominant discourse of nationalism and nationhood are fraught with their own forms of remembrance and forgetting. And yet they speak in a language of exceptionalism that mirrors a somewhat universal template for remembering “difficult pasts” characteristic of the memorial landscape of the Holocaust. Finally, it is argued that the interstices of “national memory” contain voices that unsettle or counter it. Acknowledging these voices while also recognizing their own memory politics shall broaden and nuance the dominant modes of memorializing the partition and the Liberation War in a way that better reflects the specificities and complexities of their context.
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