Multiple sclerosis (MS) develops in young adults with a complex predisposing genetic trait and probably requires an inciting environmental insult such as a viral infection to trigger the disease. The activation of CD4+ autoreactive T cells and their differentiation into a Th1 phenotype are a crucial events in the initial steps, and these cells are probably also important players in the long-term evolution of the disease. Damage of the target tissue, the central nervous system, is, however, most likely mediated by other components of the immune system, such as antibodies, complement, CD8+ T cells, and factors produced by innate immune cells. Perturbations in immunomodulatory networks that include Th2 cells, regulatory CD4+ T cells, NK cells, and others may in part be responsible for the relapsing-remitting or chronic progressive nature of the disease. However, an important paradigmatic shift in the study of MS has occurred in the past decade. It is now clear that MS is not just a disease of the immune system, but that factors contributed by the central nervous system are equally important and must be considered in the future.

Immunology of multiple sclerosis

https://absimage.aps.org/image/MAR14/MWS_MAR14-2014-020819.pdf

Van der Waals heterostructures

6G and beyond will fulfill the requirements of a fully connected world and provide ubiquitous wireless connectivity for all. Transformative solutions are expected to drive the surge for accommodating a rapidly growing number of intelligent devices and services. Major technological breakthroughs to achieve connectivity goals within 6G include: (i) a network operating at the THz band with much wider spectrum resources, (ii) intelligent communication environments that enable a wireless propagation environment with active signal transmission and reception, (iii) pervasive artificial intelligence, (iv) large-scale network automation, (v) an all-spectrum reconfigurable front-end for dynamic spectrum access, (vi) ambient backscatter communications for energy savings, (vii) the Internet of Space Things enabled by CubeSats and UAVs, and (viii) cell-free massive MIMO communication networks. In this roadmap paper, use cases for these enabling techniques as well as recent advancements on related topics are highlighted, and open problems with possible solutions are discussed, followed by a development timeline outlining the worldwide efforts in the realization of 6G. Going beyond 6G, promising early-stage technologies such as the Internet of NanoThings, the Internet of BioNanoThings, and quantum communications, which are expected to have a far-reaching impact on wireless communications, have also been discussed at length in this paper.

/pdf/6g-and-beyond-the-future-of-wireless-communications-systems-3jqy8nx3qf.pdf

6G and Beyond: The Future of Wireless Communications Systems

The major histocompatibility complex (MHC) is one of the most extensively studied regions in the human genome because of the association of variants at this locus with autoimmune, infectious, and inflammatory diseases. However, identification of causal variants within the MHC for the majority of these diseases has remained difficult due to the great variability and extensive linkage disequilibrium (LD) that exists among alleles throughout this locus, coupled with inadequate study design whereby only a limited subset of about 20 from a total of approximately 250 genes have been studied in small cohorts of predominantly European origin. We have performed a review and pooled analysis of the past 30 years of research on the role of the MHC in six genetically complex disease traits - multiple sclerosis (MS), type 1 diabetes (T1D), systemic lupus erythematosus (SLE), ulcerative colitis (UC), Crohn's disease (CD), and rheumatoid arthritis (RA) - in order to consolidate and evaluate the current literature regarding MHC genetics in these common autoimmune and inflammatory diseases. We corroborate established MHC disease associations and identify predisposing variants that previously have not been appreciated. Furthermore, we find a number of interesting commonalities and differences across diseases that implicate both general and disease-specific patho- genetic mechanisms in autoimmunity.

/pdf/defining-the-role-of-the-mhc-in-autoimmunity-a-review-and-339h3cpnyc.pdf

Defining the Role of the MHC in Autoimmunity: A Review and Pooled Analysis

During the past decade, two-dimensional materials have attracted incredible interest from the electronic device community The first two-dimensional material studied in detail was graphene and, since 2007, it has intensively been explored as a material for electronic devices, in particular, transistors While graphene transistors are still on the agenda, researchers have extended their work to two-dimensional materials beyond graphene and the number of two-dimensional materials under examination has literally exploded recently Meanwhile several hundreds of different two-dimensional materials are known, a substantial part of them is considered useful for transistors, and experimental transistors with channels of different two-dimensional materials have been demonstrated In spite of the rapid progress in the field, the prospects of two-dimensional transistors still remain vague and optimistic opinions face rather reserved assessments The intention of the present paper is to shed more light on the merits and drawbacks of two-dimensional materials for transistor electronics and to add a few more facets to the ongoing discussion on the prospects of two-dimensional transistors To this end, we compose a wish list of properties for a good transistor channel material and examine to what extent the two-dimensional materials fulfill the criteria of the list The state-of-the-art two-dimensional transistors are reviewed and a balanced view of both the pros and cons of these devices is provided

/pdf/two-dimensional-materials-and-their-prospects-in-transistor-22htc6r9e0.pdf

Two-dimensional materials and their prospects in transistor electronics

We present terahertz (THz) detectors based on top-gated graphene field effect transistors (GFETs) with integrated split bow-tie antennas. The GFETs were fabricated using graphene grown by chemical vapor deposition (CVD). The THz detectors are capable of room-temperature rectification of a 0.6 THz signal and achieve a maximum optical responsivity better than 14 V/W and minimum optical noise-equivalent power (NEP) of 515 pW/Hz(0.5). Our results are a significant improvement over previous work on graphene direct detectors and are comparable to other established direct detector technologies. This is the first time room-temperature direct detection has been demonstrated using CVD graphene, which introduces the potential for scalable, wafer-level production of graphene detectors.

https://publications.lib.chalmers.se/records/fulltext/202575/local_202575.pdf

Antenna-integrated 0.6 THz FET direct detectors based on CVD graphene.

Multiple sclerosis (MS) is a central nervous system-specific inflammatory and demyelinating disease where a myelin-directed autoimmune response is thought to be pathogenetically relevant. Myelin oligodendrocyte glycoprotein (MOG) is a surface-exposed minor myelin component that is a prime candidate autoantigen. We have investigated peripheral blood lymphocyte responses to synthetic 15 – 26 amino acids long overlapping MOG peptides in 20 MS patients and 14 healthy controls with the MS-associated HLA haplotype DR2(15). There were significantly increased responses, in terms of numbers of cells secreting IFN-γ detected by Elispot in response to several MOG-derived peptides in the MS patients, but not the healthy controls. MOG peptide 63 – 87 evoked the strongest response, and the stimulatory property of this peptide was confirmed in additional DR2(15)+ MS patients where a peptide concentration-dependent proliferative response, which was inhibited by the addition of anti-HLA class II antibodies, was observed. This is the first work detailing putative immunodominant T cell epitopes of MOG in DR2(15)+ MS patients.

Increased reactivity to myelin oligodendrocyte glycoprotein peptides and epitope mapping in HLA DR2(15)+ multiple sclerosis.

We present a flexible terahertz (THz) detector based on a graphene field-effect transistor fabricated on a plastic substrate. At room temperature, this detector reveals voltage responsivity above 2 V/W and estimated noise equivalent power (NEP) below 3 nW/Hz1/2 at 487 GHz. We have investigated the effects of bending strain on DC characteristics, voltage responsivity, and NEP of the detector, and the results reveal its robust performance. Our findings have shown that graphene is a promising material for the development of THz flexible technology.

http://publications.lib.chalmers.se/records/fulltext/250600/local_250600.pdf

A flexible graphene terahertz detector

Reported is the realisation of a graphene FET microwave amplifier operating at 1 GHz, exhibiting a small-signal power gain of 10 dB and a noise figure of 6.4 dB. The amplifier utilises a matching inductor on the gate yielding a return loss of 20 dB. The design is optimised for maximum gain and the optimum noise figure is extracted by noise modelling and predicted to be close to 1 dB for the intrinsic graphene FET at this frequency. The presented results complement existing graphene FET applications and are promising for future graphene microwave circuits.

http://publications.lib.chalmers.se/records/fulltext/local_160131.pdf

10 dB small-signal graphene FET amplifier

This letter presents a graphene field effect transistor (GFET) detector at 400 GHz, with a maximum measured optical responsivity of 74 V/W, and a minimum noise-equivalent power of 130 pW/Hz1/2. This letter shows how the detector performance degrades as a function of the residual carrier concentration in the graphene channel, which is an important material parameter that depends on the quality of the graphene sheet and contaminants introduced during the fabrication process. In this work, the exposure of the graphene channel to liquid processes is minimized resulting in a low residual carrier concentration. This is in part, an important contributing factor to achieve the record high GFET detector performance. Thus, our results show the importance to use graphene with high quality and the importance to minimize contamination during the fabrication process.

https://publications.lib.chalmers.se/records/fulltext/250996/local_250996.pdf

Michael Andersson

Papers

Antenna-integrated 0.6 THz FET direct detectors based on CVD graphene.

Increased reactivity to myelin oligodendrocyte glycoprotein peptides and epitope mapping in HLA DR2(15)+ multiple sclerosis.

A flexible graphene terahertz detector

10 dB small-signal graphene FET amplifier

A 400-GHz Graphene FET Detector