Energy Harvesting for Self-Powered Wireless Sensors

A wireless sensor system is proposed for a targeted deployment in civil infrastructures (namely bridges) to help mitigate the growing problem of deterioration of civil infrastructures. The sensor motes are self-powered via a novel magnetic shape memory alloy (MSMA) energy harvesting material and a low-frequency, low-power rectifier multiplier (RM). Experimental characterizations of the MSMA device and the RM are presented. A study on practical implementation of a strain gauge sensor and its application in the proposed sensor system are undertaken and a low-power successive approximation register analog-to-digital converter (SAR ADC) is presented. The SAR ADC was fabricated and laboratory characterizations show the proposed low-voltage topology is a viable candidate for deployment in the proposed sensor system. Additionally, a wireless transmitter is proposed to transmit the SAR ADC output using on-off keying (OOK) modulation with an impulse radio ultra-wideband (IR-UWB) transmitter (TX). The RM and SAR ADC were fabricated in ON 0.5 micrometer CMOS process. An alternative transmitter architecture is also presented for use in the 3-10GHz UWB band. Unlike the IR-UWB TX described for the proposed wireless sensor system, the presented transmitter is designed to transfer large amounts of information with little concern for power consumption. This second method of data transmission divides the 3-10GHz spectrum into 528MHz sub-bands and "hops" between these sub-bands during data transmission. The data is sent over these multiple channels for short distances (?3-10m) at data rates over a few hundred million bits per second (Mbps). An UWB TX is presented for implementation in mode-I (3.1-4.6GHz) UWB which utilizes multi-band orthogonal frequency division multiplexing (MB-OFDM) to encode the information. The TX was designed and fabricated using UMC 0.13 micrometer CMOS technology. Measurement results and theoretical system level budgeting are presented for the proposed UWB TX

Gpr17 deficiency in POMC neurons ameliorates the metabolic derangements caused by long-term high-fat diet feeding

BACKGROUND: Proopiomelanocortin (POMC) neurons in the arcuate nucleus of the hypothalamus (ARH) control energy homeostasis by sensing hormonal and nutrient cues and activating secondary melanocortin sensing neurons. We identified the expression of a G protein-coupled receptor, Gpr17, in the ARH and hypothesized that it contributes to the regulatory function of POMC neurons on metabolism. METHODS: In order to test this hypothesis, we generated POMC neuron-specific Gpr17 knockout (PGKO) mice and determined their energy and glucose metabolic phenotypes on normal chow diet (NCD) and high-fat diet (HFD). RESULTS: Adult PGKO mice on NCD displayed comparable body composition and metabolic features measured by indirect calorimetry. By contrast, PGKO mice on HFD demonstrated a sexually dimorphic phenotype with female PGKO mice displaying better metabolic homeostasis. Notably, female PGKO mice gained significantly less body weight and adiposity (p < 0.01), which was associated with increased energy expenditure, locomotor activity, and respiratory quotient, while males did not have an overt change in energy homeostasis. Though PGKO mice of both sexes had comparable glucose and insulin tolerance, detailed analyses of liver gene expression and serum metabolites indicate that PGKO mice could have reduced gluconeogenesis and increased lipid utilization on HFD. To elucidate the central-based mechanism(s) underlying the better-preserved energy and glucose homeostasis in PGKO mice on HFD, we examined the electrophysiological properties of POMC neurons and found Gpr17 deficiency led to increased spontaneous action potentials. Moreover, PGKO mice, especially female knockouts, had increased POMC-derived alpha-melanocyte stimulating hormone and beta-endorphin despite a comparable level of prohormone POMC in their hypothalamic extracts. CONCLUSIONS: Gpr17 deficiency in POMC neurons protects metabolic homeostasis in a sex-dependent manner during dietary and aging challenges, suggesting that Gpr17 could be an effective anti-obesity target in specific populations with poor metabolic control

Intracranial bleeding after reperfusion therapy in acute ischaemic stroke patients randomised to glyceryl trinitrate vs. control: an individual patient data meta-analysis

Background: Thrombolysis, with or without thrombectomy, for acute ischaemic stroke is associated with an increased risk of intracranial bleeding. We assessed whether treatment with glyceryl trinitrate (GTN), a nitric oxide donor, may influence the associated bleeding risk.Methods: We searched for completed randomized controlled trials of GTN vs. no GTN in acute ischaemic stroke with data on reperfusion treatments (thrombolysis and/or thrombectomy). The primary efficacy outcome was functional status as assessed by the modified Rankin Scale (mRS) at day 90; the primary safety outcome was intracranial bleeding. Secondary safety outcomes included symptomatic intracranial hemorrhage and haemorrhagic transformation of infarction. Individual patient data were pooled and meta-analysis performed using ordinal or binary logistic regression with adjustment for trial and prognostic variables both overall and in those randomized within 6 h of symptom onset.Results: Three trials met the eligibility criteria. Of 715 patients with ischaemic stroke who underwent thrombolysis (709, >99%) or thrombectomy (24, 3.4%), 357 (49.9%) received GTN and 358 (50.1%) received no GTN. Overall, there was no difference in the distribution of the mRS at day 90 between GTN vs. no GTN (OR 0.94, 95% CI 0.72–1.23; p = 0.65); similarly, there was no difference in intracranial hemorrhage rates between treatment groups (OR 0.90, 95% CI 0.43–1.89; p = 0.77). In those randomized to GTN vs. no GTN within 6 h of symptom onset, there were numerically fewer bleeding events, but these analyses did not reach statistical significance.Conclusions: In ischaemic stroke patients treated predominantly with thrombolysis, transdermal GTN was safe, but did not influence functional outcome at 90 days

Protocol: The Lacunar Intervention Trial 2 (LACI-2). A trial of two repurposed licenced drugs to prevent progression of cerebral small vessel disease

BackgroundSmall vessel disease causes a quarter of ischaemic strokes (lacunar subtype), up to 45% of dementia either as vascular or mixed types, cognitive impairment and physical frailty. However, there is no specific treatment to prevent progression of small vessel disease.AimWe designed the LACunar Intervention Trial-2 (LACI-2) to test feasibility of a large trial testing cilostazol and/or isosorbide mononitrate (ISMN) by demonstrating adequate participant recruitment and retention in follow-up, drug tolerability, safety and confirm outcome event rates required to power a phase 3 trial.Methods and designLACI-2 is an investigator-initiated, prospective randomised open label blinded endpoint (PROBE) trial aiming to recruit 400 patients with prior lacunar syndrome due to a small subcortical infarct. We randomise participants to cilostazol v no cilostazol and ISMN or no ISMN, minimising on key prognostic factors. All patients receive guideline-based best medical therapy. Patients commence trial drug at low dose, increment to full dose over 2–4 weeks, continuing on full dose for a year. We follow-up participants to one year for symptoms, tablet compliance, safety, recurrent vascular events, cognition and functional outcomes, Trails B and brain MRI. LACI-2 is registered ISRCTN 14911850, EudraCT 2016–002277-35.Trial outcome: Primary outcome is feasibility of recruitment and compliance; secondary outcomes include safety (cerebral or systemic bleeding, falls, death), efficacy (recurrent cerebral and cardiac vascular events, cognition on TICS, Trails B) and tolerability.SummaryLACI-2 will determine feasibility, tolerability and provide outcome rates to power a large phase 3 trial to prevent progression of cerebral small vessel disease

Ambulance-delivered transdermal glyceryl trinitrate versus sham for ultra-acute stroke: rationale, design and protocol for the Rapid Intervention with Glyceryl trinitrate in Hypertensive stroke Trial-2 (RIGHT-2) trial (ISRCTN26986053)

Rationale: Vascular nitric oxide levels are low in acute stroke and donors such as glyceryl trinitrate have shown promise when administered very early after stroke. Potential mechanisms of action include augmentation of cerebral reperfusion, thrombolysis and thrombectomy, lowering blood pressure, and cytoprotection. Aim: To test the safety and efficacy of four days of transdermal glyceryl trinitrate (5 mg/day) versus sham in patients with ultra-acute presumed stroke who are recruited by paramedics prior to hospital presentation. Sample size estimates: The sample size of 850 patients will allow a shift in the modified Rankin Scale with odds ratio 0.70 (glyceryl trinitrate versus sham, ordinal logistic regression) to be detected with 90% power at 5% significance (two-sided). Design: The Rapid Intervention with Glyceryl trinitrate in Hypertensive stroke Trial-2 (RIGHT-2) is a multicentre UK prospective randomized sham-controlled outcome-blinded parallel-group trial in 850 patients with ultra-acute (4 h of onset) FAST-positive presumed stroke and systolic blood pressure 120 mmHg who present to the ambulance service following a 999 emergency call. Data collection is performed via a secure internet site with real-time data validation. Study outcomes: The primary outcome is the modified Rankin Scale measured centrally by telephone at 90 days and masked to treatment. Secondary outcomes include: blood pressure, impairment, recurrence, dysphagia, neuroimaging markers of the acute lesion including vessel patency, discharge disposition, length of stay, death, cognition, quality of life, and mood. Neuroimaging and serious adverse events are adjudicated blinded to treatment. Discussion: RIGHT-2 has recruited more than 500 participants from seven UK ambulance services. Status: Trial is ongoing. Funding: British Heart Foundation. Registration: ISRCTN26986053

Platelet and haemoglobin levels in patients on isosorbide mononitrate and/or cilostazol with lacunar ischaemic stroke: data from the LACI-1 trial

Background: Cilostazol and isosorbide mononitrate (ISMN) have properties that may be of benefit in the context of cerebral small vessel disease and lacunar ischaemic stroke. As both drugs may influence platelet and haemoglobin levels, we sought to assess their effects using data from the lacunar intervention trial-1 (LACI-1). Methods: LACI-1 recruited 57 patients with lacunar ischaemic stroke and randomised them to ISMN or cilostazol in isolation, or combined for 9 weeks. One group received both drugs but with a delayed start. Full blood counts were taken at baseline, and weeks 3 and 8. Platelet function was assessed with remote measurement of surface expression of P-selectin (CD62P) using kits sensitive to aspirin or clopidogrel at the same timepoints. Differences in haemoglobin and platelet levels and platelet function were assessed by multiple linear regression with adjustment for baseline value. Results: Haemoglobin levels did not differ between the treatment groups at week 8 (Table), whilst platelet levels were slightly higher in those who received cilostazol compared with no cilostazol. No differences were noted in platelet function in unstimulated, aspirin or clopidogrel testing between groups. Conclusions: Cilostazol and isosorbide mononitrate have no clinically concerning effects on haemoglobin and platelet levels and function in the short to medium term. Further assessment of the safety and efficacy of these medications following lacunar ischaemic stroke is warranted

Prognostic Significance of Growth Kinetics in Newly Diagnosed Glioblastomas Revealed by Combining Serial Imaging with a Novel Biomathematical Model

Glioblastomas (GBMs) are the most aggressive primary brain tumors characterized by their rapid proliferation and diffuse infiltration of the brain tissue. Survival patterns in patients with GBM have been associated with a number of clinico-pathologic factors, including age and neurological status, yet a significant quantitative link to in vivo growth kinetics of each glioma has remained elusive. Exploiting a recently developed tool for quantifying glioma net proliferation and invasion rates in individual patients using routinely available magnetic resonance images (MRIs), we propose to link these patient-specific kinetic rates of biological aggressiveness to prognostic significance. Using our biologically-based mathematical model for glioma growth and invasion, examination of serial pre-treatment MRIs of 32 GBM patients allowed quantification of these rates for each patient’s tumor. Survival analyses revealed that even when controlling for standard clinical parameters (e.g., age, KPS) these model-defined parameters quantifying biologically aggressiveness (net proliferation and invasion rates) were significantly associated with prognosis. One hypothesis generated was that the ratio of the actual survival time after whatever therapies were employed to the duration of survival predicted (by the model) without any therapy would provide a “Therapeutic Response Index” (TRI) of the overall effectiveness of the therapies. The TRI may provided important information, not otherwise available, as to the effectiveness of the treatments in individual patients. To our knowledge, this is the first report indicating that dynamic insight from routinely obtained pre-treatment imaging may be quantitatively useful in characterizing survival of individual patients with GBM. Such a hybrid tool bridging mathematical modeling and clinical imaging may allow for statifying patients for clinical studies relative to their pretreatment biological aggressiveness

Statistical analysis plan for the ‘Rapid Intervention with Glyceryl trinitrate in Hypertensive stroke Trial-2 (RIGHT-2)’

Rationale: Glyceryl trinitrate, a nitric oxide donor, is a candidate treatment for acute stroke; it lowers blood pressure, does not alter cerebral blood flow or platelet function and is neuroprotective in experimental stroke. The ongoing rapid intervention with glyceryl trinitrate in hypertensive stroke trial-2 trial aims to assess the safety and efficacy of paramedic-delivered glyceryl trinitrate in patients with ultra-acute stroke. Aims and design: The rapid intervention with glyceryl trinitrate in hypertensive stroke trial-2 trial is a multicentre UK-based prospective randomised sham-controlled outcome-blinded parallel-group trial in patients with presumed stroke who present to the ambulance service following a 999 emergency call. The primary outcome is the modified Rankin scale measured by central telephone follow-up at 90 days. Results: This paper describes the statistical analysis plan for the rapid intervention with glyceryl trinitrate in hypertensive stroke trial-2 trial and was developed prior to unblinding to treatment allocation. The statistical analysis plan includes details of methods for analyses and unpopulated tables and figures to be included in the primary and other secondary publications. Discussion: Statistical analysis plan details what analyses will be done prior to unblinding to treatment allocation to avoid bias in the findings. Rapid intervention with glyceryl trinitrate in hypertensive stroke trial-2 trial will determine whether glyceryl trinitrate administered ultra-acutely can improve outcome after stroke. The rapid intervention with glyceryl trinitrate in hypertensive stroke trial-2 trial is registered as ISRCTN26986053