High-Speed Optical In-House Networks Using Polymeric Fibers

Data communication over polymer optical fibers (POF) is a good alternative method for local area networks to use an optical medium to transmit data in short-range environments like cars or copper in-house networks on the basis of IEEE 802.3. Many companies offer transceivers for the area of Ethernet networks in the visible wavelength range. In the first part of the chapter, a system comparison of manufacturers with interoperability check is presented. Here, the real transfer rates within a manufacturer and between all manufacturers are measured as a cross-check. In the second part of the chapter, the limitation of bandwidth due to the use of only one wavelength channel is discussed. Wavelength Division Multiplexing (WDM) is a promising candidate to significantly increase bandwidth in POF to more than 40 Gbit/s. Here, the problems in the development and manufacture of a demultiplexer (DEMUX) for WDM over POF as well as the results of the optical separation of four wavelength channels are described. At least, the possible extension of a WDM grid of ITU G.694.2 is discussed, which seems to be a hopeful candidate to introduce a standardized WDM grid for POF in the visible range to reach data rates of 40 Gbit/s up to 50 m POF

Micro-structured Optical Spectrometer Sensor in PMMA

Data communication over Polymer Optical Fibers (POF) is limited to only one channel for data transmission. Therefore the bandwidth is strongly restricted. By using more than one channel, it is possible to break through the limit. This technique is called Wavelength Division Multiplexing (WDM). It uses different wavelengths in the visible spectrum to transmit data parallel over one fiber. Two components are essential for this technology: A multiplexer (MUX) and a demultiplexer (DEMUX). The multiplexer collects the light of the different sources to one fiber and the demultiplexer separates the light at the end of the fiber into the different fiber output ports. In this paper, we show the realization of a grating spectrometer realised by injection moulding in PMMA, working in the visible spectrum, respectively. We present the results of a demonstrator of an integrated polymeric spectrometer device produced with injection moulding in combination with hot embossing. The paper discusses the results of the different development steps, the measurements done with the first demonstrator and the challenges related to the injection moulding process

EBV Negative Lymphoma and Autoimmune Lymphoproliferative Syndrome Like Phenotype Extend the Clinical Spectrum of Primary Immunodeficiency Caused by STK4 Deficiency

Serine/threonine kinase 4 (STK4) deficiency is an autosomal recessive genetic condition that leads to primary immunodeficiency (PID) typically characterized by lymphopenia, recurrent infections and Epstein Barr Virus (EBV) induced lymphoproliferation and -lymphoma. State-of-the-art treatment regimens consist of prevention or treatment of infections, immunoglobulin substitution (IVIG) and restoration of the immune system by hematopoietic stem cell transplantation. Here, we report on two patients from two consanguineous families of Turkish (patient P1) and Moroccan (patient P2) decent, with PID due to homozygous STK4 mutations. P1 harbored a previously reported frameshift (c.1103 delT, p.M368RfsX2) and P2 a novel splice donor site mutation (P2; c.525+2 T>G). Both patients presented in childhood with recurrent infections, CD4 lymphopenia and dysregulated immunoglobulin levels. Patient P1 developed a highly malignant B cell lymphoma at the age of 10 years and a second, independent Hodgkin lymphoma 5 years later. To our knowledge she is the first STK4 deficient case reported who developed lymphoma in the absence of detectable EBV or other common viruses. Lymphoma development may be due to the lacking tumor suppressive function of STK4 or the perturbed immune surveillance due to the lack of CD4+ T cells. Our data should raise physicians' awareness of [1] lymphoma proneness of STK4 deficient patients even in the absence of EBV infection and [2] possibly underlying STK4 deficiency in pediatric patients with a history of recurrent infections, CD4 lymphopenia and lymphoma and unknown genetic make-up. Patient P2 experienced recurrent otitis in childhood, but when she presented at the age of 14, she showed clinical and immunological characteristics similar to patients suffering from Autoimmune Lymphoproliferative Syndrome (ALPS): elevated DNT cell number, non-malignant lymphadenopathy and hepatosplenomegaly, hematolytic anemia, hypergammaglobulinemia. Also patient P1 presented with ALPS-like features (lymphadenopathy, elevated DNT cell number and increased Vitamin B12 levels) and both were initially clinically diagnosed as ALPS-like. Closer examination of P2, however, revealed active EBV infection and genetic testing identified a novel STK4 mutation. None of the patients harbored typically ALPS-associated mutations of the Fas receptor mediated apoptotic pathway and Fas-mediated apoptosis was not affected. The presented case reports extend the clinical spectrum of STK4 deficiency

A lab-on-a-chip system with an embedded porous membrane-based impedance biosensor array for nanoparticle risk assessment on placental Bewo trophoblast cells

The human placenta is a unique organ serving as the lung, gut, liver, and kidney of the fetus, mediating the exchange of different endogenous as well as exogenous substances and gases between the mother and fetus during pregnancy. Additionally, the placental barrier protects the fetus from a range of environmental toxins, bacterial and viral infections, since any contaminant bridging the placenta may have unforeseeable effects on embryonal and fetal development. A more recent concern in placenta research, however, involves the ability of engineered nanoparticles to cross the placental barrier and/or affect its barrier function. To advance nanoparticle risk assessment at the human placental barrier, we have developed as proof-of-principle a highly integrated placenta-on-a-chip system containing embedded membrane-bound impedance microsensor arrays capable of non-invasively monitoring placental barrier integrity. Barrier integrity is continuously and label-free evaluated using porous membrane-based interdigitated electrode structures located on top of a porous PET membrane supporting a barrier of trophoblast-derived BeWo cell barrier in the absence and presence of standardized silicon dioxide (SiO2), titanium dioxide (TiO2), and zinc oxide (ZnO) nanomaterials.This work has been funded by the European Union’s Horizon 2020 research and innovation program under grant agreement No. 685817.Peer reviewe

Latest Trends in Biosensing for Microphysiological Organs-on-a-Chip and Body-on-a-Chip Systems

Organs-on-chips are considered next generation in vitro tools capable of recreating in vivo like, physiological-relevant microenvironments needed to cultivate 3D tissue-engineered constructs (e.g., hydrogel-based organoids and spheroids) as well as tissue barriers. These microphysiological systems are ideally suited to (a) reduce animal testing by generating human organ models, (b) facilitate drug development and (c) perform personalized medicine by integrating patient-derived cells and patient-derived induced pluripotent stem cells (iPSCs) into microfluidic devices. An important aspect of any diagnostic device and cell analysis platform, however, is the integration and application of a variety of sensing strategies to provide reliable, high-content information on the health status of the in vitro model of choice. To overcome the analytical limitations of organs-on-a-chip systems a variety of biosensors have been integrated to provide continuous data on organ-specific reactions and dynamic tissue responses. Here, we review the latest trends in biosensors fit for monitoring human physiology in organs-on-a-chip systems including optical and electrochemical biosensors

A decade of organs-on-a-chip emulating human physiology at the microscale: a critical status report on progress in toxicology and pharmacology

Organ-on-a-chip technology has the potential to accelerate pharmaceutical drug development, improve the clinical translation of basic research, and provide personalized intervention strategies. In the last decade, big pharma has engaged in many academic research cooperations to develop organ-on-a-chip systems for future drug discoveries. Although most organ-on-a-chip systems present proof-of-concept studies, miniaturized organ systems still need to demonstrate translational relevance and predictive power in clinical and pharmaceutical settings. This review explores whether microfluidic technology succeeded in paving the way for developing physiologically relevant human in vitro models for pharmacology and toxicology in biomedical research within the last decade. Individual organ-on-a-chip systems are discussed, focusing on relevant applications and highlighting their ability to tackle current challenges in pharmacological research

Hydraulic functioning of tree stems—fusing ray anatomy, radial transfer and capacitance

Not long ago, textbooks on plant physiology divulged the view that phloem and xylem are separate transport systems with exclusive functions. Phloem was flowing downwards providing roots with carbohydrates. Xylem transported water upwards from roots to leaves. This simplified view has changed forever. Today we have a much-refined understanding of the complex transport mechanisms, regulatory functions and surprisingly ingenuous solutions trees have evolved to distribute carbohydrates and water internally to fuel growth and help mediate biotic and abiotic stresses. This review focuses on functional links between tissues of the inner bark region (i.e., more than just phloem) and the xylem, facilitated by radially aligned and interconnected parenchyma cells, called rays. Rays are usually found along the entire vertical axis of tree stems, mediating a number of transport processes. We use a top-down approach to unveil the role of rays in these processes. Due to the central role of rays in facilitating the coupling of inner bark and xylem we dedicate the first section to ray anatomy, pathways and control mechanisms involved in radial transport. In the second section, basic concepts and models for radial movement through rays are introduced and their impacts on water and carbon fluxes at the whole-tree level are discussed. This section is followed by a closer look at the capacitive function of composite tissues in stems where gradual changes in water potential generate a diurnal 'pulse'. We explain how this pulse can be measured and interpreted, and where the limitations of such analyses are. Towards the end of this review, we include a brief description of the role of radial transport during limited availability of water. By elucidating the strong hydraulic link between inner bark and xylem, the traditional view of two separate transport systems dissolves and the idea of one interconnected, yet highly segregated transport network for carbohydrates and water arises