A novel and miniaturized 433/868MHz multi-band wireless sensor platform for body sensor network applications

Body Sensor Network (BSN) technology is seeing a rapid emergence in application areas such as health, fitness and sports monitoring. Current BSN wireless sensors typically operate on a single frequency band (e.g. utilizing the IEEE 802.15.4 standard that operates at 2.45GHz) employing a single radio transceiver for wireless communications. This allows a simple wireless architecture to be realized with low cost and power consumption. However, network congestion/failure can create potential issues in terms of reliability of data transfer, quality-of-service (QOS) and data throughput for the sensor. These issues can be especially critical in healthcare monitoring applications where data availability and integrity is crucial. The addition of more than one radio has the potential to address some of the above issues. For example, multi-radio implementations can allow access to more than one network, providing increased coverage and data processing as well as improved interoperability between networks. A small number of multi-radio wireless sensor solutions exist at present but require the use of more than one radio transceiver devices to achieve multi-band operation. This paper presents the design of a novel prototype multi-radio hardware platform that uses a single radio transceiver. The proposed design allows multi-band operation in the 433/868MHz ISM bands and this, together with its low complexity and small form factor, make it suitable for a wide range of BSN applications

Admittance Method for Estimating Local Field Potentials Generated in a Multi-Scale Neuron Model of the Hippocampus

Significant progress has been made toward model-based prediction of neral tissue activation in response to extracellular electrical stimulation, but challenges remain in the accurate and efficient estimation of distributed local field potentials (LFP). Analytical methods of estimating electric fields are a first-order approximation that may be suitable for model validation, but they are computationally expensive and cannot accurately capture boundary conditions in heterogeneous tissue. While there are many appropriate numerical methods of solving electric fields in neural tissue models, there isn\u27t an established standard for mesh geometry nor a well-known rule for handling any mismatch in spatial resolution. Moreover, the challenge of misalignment between current sources and mesh nodes in a finite-element or resistor-network method volume conduction model needs to be further investigated. Therefore, using a previously published and validated multi-scale model of the hippocampus, the authors have formulated an algorithm for LFP estimation, and by extension, bidirectional communication between discretized and numerically solved volume conduction models and biologically detailed neural circuit models constructed in NEURON. Development of this algorithm required that we assess meshes of (i) unstructured tetrahedral and grid-based hexahedral geometries as well as (ii) differing approaches for managing the spatial misalignment of current sources and mesh nodes. The resulting algorithm is validated through the comparison of Admittance Method predicted evoked potentials with analytically estimated LFPs. Establishing this method is a critical step toward closed-loop integration of volume conductor and NEURON models that could lead to substantial improvement of the predictive power of multi-scale stimulation models of cortical tissue. These models may be used to deepen our understanding of hippocampal pathologies and the identification of efficacious electroceutical treatments

A dual-ISM-band antenna of small size using a spiral structure with parasitic element

This letter presents a compact, single-feed, dual-band antenna covering both the 433-MHz and 2.45-GHz Industrial Scientific and Medical (ISM) bands. The antenna has small dimensions of 51 ×28 mm². A square-spiral resonant element is printed on the top layer for the 433-MHz band. The remaining space within the spiral is used to introduce an additional parasitic monopole element on the bottom layer that is resonant at 2.45 GHz. Measured results show that the antenna has a 10-dB return-loss bandwidth of 2 MHz at 433 MHz and 132 MHz at 2.45 GHz, respectively. The antenna has omnidirectional radiation characteristics with a peak realized gain (measured) of -11.5 dBi at 433 MHz and +0.5 dBi at 2.45 GHz, respectively

Design of a compact, fully-autonomous 433 MHz tunable antenna for wearable wireless sensor applications

The authors present the design of a tunable 433 MHz antenna that is tailored for wearable wireless sensor applications. This study first presents a detailed analysis of the measured impedance characteristics of a chosen antenna under test (AUT) in varying proximity to a human test subject. Instead of limiting the analysis to the head and hand only, this analysis measures the AUT impedance at varying distances from 11 different body positions. A novel antenna equivalent circuit model is then developed that enables both the free-space and total on-body AUT impedance variation to be rapidly computed using a circuit simulator instead of the requirement for computationally intensive finite-element methods for example. The design and characterisation of a tunable matching network that enables AUT impedance matching for 11 different positions on the human body is then outlined. Finally, a fully-autonomous 433 MHz tunable antenna is demonstrated. The antenna occupies a small printed circuit board area of 51 × 28 mm and is printed on standard FR-4 material with the tuner completely integrated into the antenna itself. Prototype measurements show an improvement of 3.9 dB in power delivery to the antenna for a load voltage standing wave ratio of 17:1, with a maximum matching loss of 0.84 dB and S 11 (−10 dB) ≥ 18 MHz for all load conditions

An unusual case of suprascapular nerve neuropathy: a case report

<p>Abstract</p> <p>Introduction</p> <p>Suprascapular nerve neuropathy constitutes an unusual cause of shoulder weakness, with the most common etiology being nerve compression from a ganglion cyst at the suprascapular or spinoglenoid notch. We present a puzzling case of a man with suprascapular nerve neuropathy that may have been associated with an appendectomy. The case was attributed to nerve injury as the most likely cause that may have occurred during improper post-operative patient mobilization.</p> <p>Case presentation</p> <p>A 23-year-old Caucasian man presented to an orthopedic surgeon with a history of left shoulder weakness of several weeks' duration. The patient complained of pain and inability to lift minimal weight, such as a glass of water, following an appendectomy. His orthopedic clinical examination revealed obvious atrophy of the supraspinatus and infraspinatus muscles and 2 of 5 muscle strength scores on flexion resistance and external rotation resistance. Magnetic resonance imaging showed diffuse high signal intensity within the supraspinatus and infraspinatus muscles and early signs of minimal fatty infiltration consistent with denervation changes. No compression of the suprascapular nerve in the suprascapular or spinoglenoid notch was noted. Electromyographic studies showed active denervation effects in the supraspinatus muscle and more prominent in the left infraspinatus muscle. The findings were compatible with damage to the suprascapular nerve, especially the part supplying the infraspinatus muscle. On the basis of the patient's history, clinical examination, and imaging studies, the diagnosis was suspected to be associated with a possible traction injury of the suprascapular nerve that could have occurred during the patient's transfer from the operating table following an appendectomy.</p> <p>Conclusion</p> <p>Our case report may provide important insight into patient transfer techniques used by hospital personnel, may elucidate the clinical significance of careful movement of patients following general anesthesia, and may have important implications for patient safety techniques, including those outlined in the World Health Organization Surgical Safety Checklist program.</p

Development of a Fully Human Anti-PDGFRβ Antibody That Suppresses Growth of Human Tumor Xenografts and Enhances Antitumor Activity of an Anti-VEGFR2 Antibody

Platelet-derived growth factor receptor β (PDGFRβ) is upregulated in most of solid tumors. It is expressed by pericytes/smooth muscle cells, fibroblast, macrophage, and certain tumor cells. Several PDGF receptor-related antagonists are being developed as potential antitumor agents and have demonstrated promising antitumor activity in both preclinical and clinical settings. Here, we produced a fully human neutralizing antibody, IMC-2C5, directed against PDGFRβ from an antibody phage display library. IMC-2C5 binds to both human and mouse PDGFRβ and blocks PDGF-B from binding to the receptor. IMC-2C5 also blocks ligand-stimulated activation of PDGFRβ and downstream signaling molecules in tumor cells. In animal studies, IMC-2C5 significantly delayed the growth of OVCAR-8 and NCI-H460 human tumor xenografts in nude mice but failed to show antitumor activities in OVCAR-5 and Caki-1 xenografts. Our results indicate that the antitumor efficacy of IMC-2C5 is primarily due to its effects on tumor stroma, rather than on tumor cells directly. Combination of IMC-2C5 and DC101, an anti-mouse vascular endothelial growth factor receptor 2 antibody, resulted in significantly enhanced antitumor activity in BxPC-3, NCI-H460, and HCT-116 xenografts, compared with DC101 alone, and the trend of additive effects to DC101 treatment in several other tumor models. ELISA analysis of NCI-H460 tumor homogenates showed that IMC-2C5 attenuated protein level of vascular endothelial growth factor and basic fibroblast growth factor elevated by DC101 treatment. Finally, IMC-2C5 showed a trend of additive effects when combined with DC101/chemotherapy in MIA-PaCa-2 and NCI-H460 models. Taken together, these results lend great support to the use of PDGFRβ antagonists in combination with other antiangiogenic agents in the treatment of a broad range of human cancers

Evolutionary connectionism: algorithmic principles underlying the evolution of biological organisation in evo-devo, evo-eco and evolutionary transitions

The mechanisms of variation, selection and inheritance, on which evolution by natural selection depends, are not fixed over evolutionary time. Current evolutionary biology is increasingly focussed on understanding how the evolution of developmental organisations modifies the distribution of phenotypic variation, the evolution of ecological relationships modifies the selective environment, and the evolution of reproductive relationships modifies the heritability of the evolutionary unit. The major transitions in evolution, in particular, involve radical changes in developmental, ecological and reproductive organisations that instantiate variation, selection and inheritance at a higher level of biological organisation. However, current evolutionary theory is poorly equipped to describe how these organisations change over evolutionary time and especially how that results in adaptive complexes at successive scales of organisation (the key problem is that evolution is self-referential, i.e. the products of evolution change the parameters of the evolutionary process). Here we first reinterpret the central open questions in these domains from a perspective that emphasises the common underlying themes. We then synthesise the findings from a developing body of work that is building a new theoretical approach to these questions by converting well-understood theory and results from models of cognitive learning. Specifically, connectionist models of memory and learning demonstrate how simple incremental mechanisms, adjusting the relationships between individually-simple components, can produce organisations that exhibit complex system-level behaviours and improve the adaptive capabilities of the system. We use the term “evolutionary connectionism” to recognise that, by functionally equivalent processes, natural selection acting on the relationships within and between evolutionary entities can result in organisations that produce complex system-level behaviours in evolutionary systems and modify the adaptive capabilities of natural selection over time. We review the evidence supporting the functional equivalences between the domains of learning and of evolution, and discuss the potential for this to resolve conceptual problems in our understanding of the evolution of developmental, ecological and reproductive organisations and, in particular, the major evolutionary transitions

Maximal Wall Thickness Measurement in Hypertrophic Cardiomyopathy: Biomarker Variability and its Impact on Clinical Care

OBJECTIVES: The aim of this study was to define the variability of maximal wall thickness (MWT) measurements across modalities and predict its impact on care in patients with hypertrophic cardiomyopathy (HCM). BACKGROUND: Left ventricular MWT measured by echocardiography or cardiovascular magnetic resonance (CMR) contributes to the diagnosis of HCM, stratifies risk, and guides key decisions, including whether to place an implantable cardioverter-defibrillator (ICD). METHODS: A 20-center global network provided paired echocardiographic and CMR data sets from patients with HCM, from which 17 paired data sets of the highest quality were selected. These were presented as 7 randomly ordered pairs (at 6 cardiac conferences) to experienced readers who report HCM imaging in their daily practice, and their MWT caliper measurements were captured. The impact of measurement variability on ICD insertion decisions was estimated in 769 separately recruited multicenter patients with HCM using the European Society of Cardiology algorithm for 5-year risk for sudden cardiac death. RESULTS: MWT analysis was completed by 70 readers (from 6 continents; 91% with >5 years' experience). Seventy-nine percent and 68% scored echocardiographic and CMR image quality as excellent. For both modalities (echocardiographic and then CMR results), intramodality inter-reader MWT percentage variability was large (range -59% to 117% [SD ±20%] and -61% to 52% [SD ±11%], respectively). Agreement between modalities was low (SE of measurement 4.8 mm; 95% CI 4.3 mm-5.2 mm; r = 0.56 [modest correlation]). In the multicenter HCM cohort, this estimated echocardiographic MWT percentage variability (±20%) applied to the European Society of Cardiology algorithm reclassified risk in 19.5% of patients, which would have led to inappropriate ICD decision making in 1 in 7 patients with HCM (8.7% would have had ICD placement recommended despite potential low risk, and 6.8% would not have had ICD placement recommended despite intermediate or high risk). CONCLUSIONS: Using the best available images and experienced readers, MWT as a biomarker in HCM has a high degree of inter-reader variability and should be applied with caution as part of decision making for ICD insertion. Better standardization efforts in HCM recommendations by current governing societies are needed to improve clinical decision making in patients with HCM

A Transcript Cleavage Factor of Mycobacterium tuberculosis Important for Its Survival

After initiation of transcription, a number of proteins participate during elongation and termination modifying the properties of the RNA polymerase (RNAP). Gre factors are one such group conserved across bacteria. They regulate transcription by projecting their N-terminal coiled-coil domain into the active center of RNAP through the secondary channel and stimulating hydrolysis of the newly synthesized RNA in backtracked elongation complexes. Rv1080c is a putative gre factor (MtbGre) in the genome of Mycobacterium tuberculosis. The protein enhanced the efficiency of promoter clearance by lowering abortive transcription and also rescued arrested and paused elongation complexes on the GC rich mycobacterial template. Although MtbGre is similar in domain organization and shares key residues for catalysis and RNAP interaction with the Gre factors of Escherichia coli, it could not complement an E. coli gre deficient strain. Moreover, MtbGre failed to rescue E. coli RNAP stalled elongation complexes, indicating the importance of specific protein-protein interactions for transcript cleavage. Decrease in the level of MtbGre reduced the bacterial survival by several fold indicating its essential role in mycobacteria. Another Gre homolog, Rv3788 was not functional in transcript cleavage activity indicating that a single Gre is sufficient for efficient transcription of the M. tuberculosis genome