Precision-microfabricated fiber-optic probe for intravascular pressure and temperature sensing

Small form-factor sensors are widely used in minimally invasive intravascular diagnostic procedures. Manufacturing complexities associated with miniaturizing current fiber-optic probes, particularly for multi-parameter sensing, severely constrain their adoption outside of niche fields. It is especially challenging to rapidly prototype and iterate upon sensor designs to optimize performance for medical devices. In this work, a novel technique to construct a microscale extrinsic fiber-optic sensor with a confined air cavity and sub-micron geometric resolution is presented. The confined air cavity is enclosed between a 3 μm thick pressure-sensitive distal diaphragm and a proximal temperature-sensitive plano-convex microlens segment unresponsive to changes in external pressure. Simultaneous pressure and temperature measurements are possible through optical interrogation via phase-resolved low-coherence interferometry(LCI). Upon characterization in a simulated intravascular environment, we find these sensors capable of detecting pressure changes down to 0.11 mmHg (in the range of 760 to 1060 mmHg) and temperature changes of 0.036°C (in the range 34 to 50°C). By virtue of these sensitivity values suited to intravascular physiological monitoring, and the scope of design flexibility enabled by the precision-fabricated photoresist microstructure, it is envisaged that this technique will enable construction of a wide range of fiber-optic sensors for guiding minimally invasive medical procedures

Optical interferometric temperature sensors for intravascular blood flow measurements

Direct and continuous measurements of blood flow are of significant interest in many medical specialties. In cardiology, intravascular physiological measurements can be of critical importance to determine whether coronary stenting should be performed. Intravascular pressure is a physiological parameter that is frequently measured in clinical practice. An increasing body of evidence suggests that direct measurements of blood flow, as additional physiological parameters, could improve decision making. In this study, we developed a novel fibre optic intravascular flow sensor, which enabled time-of-flight measurements by upstream thermal tagging of blood. This flow sensor comprised a temperature sensitive polymer dome at the distal end of a single mode optical fibre. The dome was continuously interrogated by low coherence interferometry to measure thermally-induced length changes with nanometre-scale resolution. Flow measurements were performed by delivering heat upstream from the sensor with a separate optical fibre, and monitoring the temperature downstream at the dome with a sample rate of 50 Hz. A fabricated flow sensor was characterized and tested within a benchtop phantom, which comprised vessels with lumen diameters that ranged from 2.5 to 5 mm. Water was used as a blood mimicking fluid. For each vessel diameter, a pump provided constant volumetric flow at rates in the range of 5 to 200 ml/min. This range was chosen to represent flow rates encountered in healthy human vessels. Laser light pulses with a wavelength of 1470 nm and durations of 0.4 s were used to perform upstream thermal tagging. These pulses resulted in downstream temperature profiles that varied with the volumetric flow rate

Bruck syndrome in pregnancy.

Bruck syndrome is a rare, autosomal-recessive condition associated with features of both arthrogryposis and osteogenesis imperfecta. It is characterised by congenital large joint contractures with pterygia and bone fragility, leading to fractures and deformities, along with a short stature caused by progressive skeletal deformities. There are fewer than 50 described cases of Bruck syndrome in the literature, with no reported cases in pregnancy. We describe a case of a successful pregnancy in a woman with Bruck syndrome.In pregnant women with Bruck syndrome, we recommend a multidisciplinary approach including input from obstetric and fetal medicine specialists, midwives, anaesthetists, geneticists, occupational therapists and physiotherapists

Luciferase-free Luciferin Electrochemiluminescence

Luciferin is one of Nature's most widespread luminophores, and enzymes that catalyze luciferin luminescence are the basis of successful commercial “glow” assays for gene expression and metabolic ATP formation. Herein we report an electrochemical method to promote firefly's luciferin luminescence in the absence of its natural biocatalyst—luciferase. We have gained experimental and computational insights on the mechanism of the enzyme-free luciferin electrochemiluminescence, demonstrated its spectral tuning from green to red by means of electrolyte engineering, proven that the colour change does not require, as still debated, a keto/enol isomerization of the light emitter, and gained evidence of the electrostatic-assisted stabilization of the charge-transfer excited state by double layer electric fields. Luciferin's electrochemiluminescence, as well as the in situ generation of fluorescent oxyluciferin, are applied towards an optical measurement of diffusion coefficients

Labetalol Versus Nifedipine as Antihypertensive Treatment for Chronic Hypertension in Pregnancy: A Randomized Controlled Trial

Data from randomized controlled trials to guide antihypertensive agent choice for chronic hypertension in pregnancy are limited; this study aimed to compare labetalol and nifedipine, additionally assessing the impact of ethnicity on treatment efficacy. Pregnant women with chronic hypertension (12+0-27+6 weeks' gestation) were enrolled at 4 UK centers (August 2014 to October 2015). Open-label first-line antihypertensive treatment was randomly assigned: labetalol- (200-1800 mg/d) or nifedipine-modified release (20-80 mg/d). Analysis included 112 women (98%) who completed the study (labetalol n=55, nifedipine n=57). Maximum blood pressure after randomization was 161/101 mm Hg with labetalol versus 163/105 mm Hg with nifedipine (mean difference systolic: 1.2 mm Hg [-4.9 to 7.2 mm Hg], diastolic: 3.3 mm Hg [-0.6 to 7.3 mm Hg]). Mean blood pressure was 134/84 mm Hg with labetalol and 134/85 mm Hg with nifedipine (mean difference systolic: 0.3 mm Hg [-2.8 to 3.4 mm Hg], and diastolic: -1.9 mm Hg [-4.1 to 0.3 mm Hg]). Nifedipine use was associated with a 7.4-mm Hg reduction (-14.4 to -0.4 mm Hg) in central aortic pressure, measured by pulse wave analysis. No difference in treatment effect was observed in black women (n=63), but a mean 4 mm Hg reduction (-6.6 to -0.8 mm Hg; P=0.015) in brachial diastolic blood pressure was observed with labetalol compared with nifedipine in non-black women (n=49). Labetalol and nifedipine control mean blood pressure to target in pregnant women with chronic hypertension. This study provides support for a larger definitive trial scrutinizing the benefits and side effects of first-line antihypertensive treatment. CLINICAL TRIAL REGISTRATION: URL: https://www.isrctn.com. Unique identifier: ISRCTN40973936

tert-Butyl 2-hy­droxy-3-(4-methyl­benzene­sulfonamido)­butano­ate

In the crystal of the title compound, C15H23NO5S, mol­ecules are linked through N—H⋯O and O—H⋯O hydrogen-bond inter­actions, resulting in centrosymmetric dimers in which the N—H⋯O inter­actions generate R 2 2(12) rings and the O—H⋯O inter­actions generate R 2 2(14) rings. Weak inter­molecular C—H⋯O inter­actions are also observed

(2R,3S)-Methyl 2-hy­droxy-3-(4-methyl­benzene­sulfonamido)-3-phenyl­propano­ate

In the title mol­ecule, C17H19NO5S, the p-tolyl ring is oriented approximately parallel to the phenyl ring [dihedral angle = 17.2 (1)°], resulting in an intra­molecular π–π inter­ation [centroid–centroid distance = 3.184 (10) Å]. In the crystal, mol­ecules are linked through O—H⋯O and C—H⋯O hydrogen bonds, forming hydrogen-bonded sheets lying diagonally across the ac face

3D printed micro-scale fiber optic probe for intravascular pressure sensing

Small form-factor invasive pressure sensors are widely used in minimally invasive surgery, for example to guide decision making in coronary stenting procedures. Current fiber-optic sensors can have high manufacturing complexities and costs, which severely constrains their adoption outside of niche fields. A particular challenge is the ability to rapidly prototype and iterate upon sensor designs to optimize performance for different applications and medical devices. Here, we present a new sensor fabrication method, which involves two-photon polymerization printing and integration of the printed structure onto the end-face of a single-mode optical fiber. The active elements of the sensor were a pressure-sensitive diaphragm and an intermediate temperature-sensitive spacer that was insensitive to changes in external pressure. Deflection of the diaphragm and thermal expansion the spacer relative to the fiber end-face were monitored using phase-resolved low coherence interferometry. A pressure sensitivity of 0.031 rad/mmHg across the range of 760 to 1060 mmHg (absolute pressure), and a temperature sensitivity of 1.2 mrad/°C across the range 20 to 45°C were observed. This method will enable the fabrication of a wide range of fiber-optic sensors with pressure and temperature sensitivities suitable for guiding minimally invasive surgery

Mothers behaving badly: chaotic hedonism and the crisis of neoliberal social reproduction

This article focuses on the significance of the plethora of representations of mothers ‘behaving badly’ in contemporary anglophone media texts, including the films Bad Moms, Fun Mom Dinner and Bad Mom’s Christmas, the book and online cartoons Hurrah for Gin and the recent TV comedy dramas Motherland, The Let Down and Catastrophe. All these media texts include representations of, first, mothers in the midst of highly chaotic everyday spaces where any smooth routine of domesticity is conspicuous by its absence; and second, mothers behaving hedonistically, usually through drinking and partying, behaviour that is more conventionally associated with men or women without children. After identifying the social type of the mother behaving badly (MBB), the article locates and analyses it in relation to several different social and cultural contexts. These contexts are: a neoliberal crisis in social reproduction marked by inequality and overwork; the continual if contested role of women as ‘foundation parents’; and the negotiation of longer-term discourses of female hedonism. The title gestures towards a popular British sitcom of the 1990s, Men Behaving Badly, which popularized the idea of the ‘new lad’; and this article suggests that the new lad’s counterpart, the ladette, is mutating into the mother behaving badly, or the ‘lad mom’. Asking what work this figure does now, in a later neoliberal context, it argues that the mother behaving badly is simultaneously indicative of a widening and liberating range of maternal subject positions and symptomatic of a profound contemporary crisis in social reproduction. By focusing on the classed and racialised dynamics of the MBB – by examining who exactly is permitted to be hedonistic, and how – and by considering the MBB’s limited and partial imagining of progressive social change, the article concludes by emphasizing the urgency of creating more connections between such discourses and ‘parents behaving politically’