Realisation of an optical pressure standard by a multi-reflection interferometric technique

A novel realization of an optical pressure standard, alternative to Fabry-Perot cavity-based techniques, is presented. It is based on the measurement of the refractive index of a gas through an unbalanced homodyne interferometer, designed to have one of its two arms formed by a multi reflection double mirror assembly to establish an unbalance length larger than 6 m in a compact setup. The paper illustrates the most important steps concerning its realization: the estimate of the pressure-induced deformation of the interferometer, the temperature control at millikelvin level and the measurement in vacuum of the unbalance of the interferometer. The evaluation of the uncertainty of the realized optical pressure standard currently demonstrated to fulfill the main goal of having the ability to measure pressure with a relative uncertainty of 10 ppm at 100 kPa

Long-term follow-up after surgical removal of meningioma of the inner third of the sphenoidal wing: outcome determinants and different strategies

Meningioma arising in the inner third of the sphenoidal wing has been well recognized since the origin of neurosurgery, yet it still poses a formidable challenge for the surgeon. Treatment strategies can be optimized through a tailored approach to surgical timing and use of a non-surgical armamentarium. The aim of this study was to evaluate the long-term effect of different strategies on progression-free survival and overall survival. We examined the clinical records of brain tumor patients to assess determinants for surgery (extent of tumor removal, postoperative complications) and for progression-free survival and overall survival in relation to timing of surgery eventually followed by stereotactic radiosurgery (SRS). The records of 60 patients were retrospectively reviewed, from preoperative assessment to a median follow-up of 104 months. All were symptomatic with prevalently visual symptoms (42.2%), large tumors (median diameter 3.44 cm), extension into the cavernous sinus (38.3%), and severe vascular involvement of one or more encased or narrowed vessels (50%). Subtotal removal was achieved in 40% of cases, mainly determined by cavernous sinus and vascular involvement; neurological complications occurred in 18.3% (persistent in 6.7% due to oculomotor and vascular injury). The overall rate of symptom improvement was 32.3% at 3 months and 49.5% at 12 months. Radiological monitoring prevented clinical progression; tumor progression occurred in 11.7% of cases. There were significant differences in progression-free survival between patients with (median 46 months) and those without (median 104 months) recurrence (p = 0.002): 12.5% after total removal, 6.2% after subtotal removal and adjuvant SRS, and 28.5% after subtotal removal and observation. The related Kaplan-Meier survival curve showed no significant difference between the three strategies. Further, disease progression after recurrence was noted in 28.6% of cases, but overall survival was not influenced by either tumor recurrence or type of treatment. Treatment failure was recorded in four cases (6.7%): one perioperative death and three later on. Surgery is the mainstay for the treatment of symptomatic meningioma and to restore neurological function; however, resectability is limited by vascular and cavernous sinus involvement. Careful postoperative monitoring prevented clinical progression and adjuvant or adjunctive SRS proved effective in tumor control. A low surgical complication rate and excellent long-term outcomes were achieved with this strategy

MSEC2006-21098 RESULTS OF CYLINDER BORE INSPECTION PROBE MEASUREMENTS

ABSTRACT A non contact optical technique for mapping the surface finish of cylinder bores has been developed, and a probe has been built for performing this mapping by scanning the surface of a cylinder with a laser beam and recording the intensity of scattered light detected as a function of position on the cylinder surface. The probe is not a surface roughness gauge. It is used primarily to distinguish the scattering signatures from different patterns of machining marks. For identical patterns of machining marks scattered light intensity is expected to be proportional to surface roughness. Measurement of a cylinder takes about 10 seconds using this probe. If an array of probes were used to inspect the cylinders of an engine block simultaneously, this technique could be used for 100% inspection of the entire surface of every cylinder of every block at the speed of an engine production line. In this paper we present data from a proof of concept experiment, describe the method of analyzing the data, and outline plans for future implementation of an inspection station on an engine block production line

Alginate beads to improve viability of Lactobacillus plantarum to heat stress

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CIRCULAR COMPARISON OF CONVENTIONAL PRESSURE STANDARDS USING A TRANSPORTABLE OPTICAL REFRACTOMETER: PREPARATION AND TRANSPORTATION

Using a transportable Fabry-Pérot cavity refractometer, a circular comparison of existing primary standards at several national metrology institutes is currently underway. This paper provides information about the refractometer, the preparation for the comparison, and the transportation procedur

Transparency meets management: A monitoring and evaluating tool for governmental projects

The Brazilian government is maintaining several digital inclusion projects, providing computers and Internet connection to developing regions around the country. However, these projects can only succeed if they are constantly assessed; namely, the projects infrastructure deployment must be closely monitored and evaluated. In this paper, we introduce a system called SIMMC, which is currently monitoring and evaluating more than 4,500 computing devices from Brazilian digital inclusion projects. This system is innovative because, in addition to being used by the government for managing and expanding its projects, the collected data is also publicly available on a web page, allowing the citizens to follow the projects' deployment. We describe the SIMMC architecture, reporting some techniques used to optimize its data analysis processes, and describe how the information acquired and presented by the system has been used to enable public administration overhaul and improve efficiency on the project management, as well as its strategic use for security, theft, and defrauding

Monitoring contractility in cardiac tissue with cellular resolution using biointegrated microlasers

Funding: This research was financially supported by the European Research Council under the European Union’s Horizon 2020 Framework Programme (FP/2014-2020)/ERC grant agreement no. 640012 (ABLASE), by EPSRC (grant no. EP/P030017/1) and by the RS Macdonald Charitable Trust. S.J.P. acknowledges funding by the Royal Society of Edinburgh (Biomedical Fellowship) and the British Heart Foundation (grant no. FS/17/9/32676). S.J.P. and G.B.R. acknowledge support from The Wellcome Trust Institutional Strategic Support Fund to the University of St Andrews (grant no. 204821/Z/16/A). M.S. acknowledges funding by the European Commission (Marie Skłodowska-Curie Individual Fellowship, 659213) and the Royal Society (Dorothy Hodgkin Fellowship, DH160102; grant no. RGF\R1\180070).The contractility of cardiac cells is a key parameter that describes the biomechanical characteristics of the beating heart, but functional monitoring of three-dimensional cardiac tissue with single-cell resolution remains a major challenge. Here, we introduce microscopic whispering-gallery-mode lasers into cardiac cells to realize all-optical recording of transient cardiac contraction profiles with cellular resolution. The brilliant emission and high spectral sensitivity of microlasers to local changes in refractive index enable long-term tracking of individual cardiac cells, monitoring of drug administration, accurate measurements of organ-scale contractility in live zebrafish, and robust contractility sensing through hundreds of micrometres of rat heart tissue. Our study reveals changes in sarcomeric protein density as an underlying factor to cardiac contraction. More broadly, the use of novel micro- and nanoscopic lasers as non-invasive, biointegrated optical sensors brings new opportunities to monitor a wide range of physiological parameters with cellular resolution.PostprintPeer reviewe

The unruptured intracranial aneurysm treatment score A multidisciplinary consensus

Objective: We endeavored to develop an unruptured intracranial aneurysm (UIA) treatment score (UIATS) model that includes and quantifies key factors involved in clinical decision-making in the management of UIAs and to assess agreement for this model among specialists in UIA management and research. Methods: An international multidisciplinary (neurosurgery, neuroradiology, neurology, clinical epidemiology) group of 69 specialists was convened to develop and validate the UIATS model using a Delphi consensus. For internal (39 panel members involved in identification of relevant features) and external validation (30 independent external reviewers), 30 selected UIA cases were used to analyze agreement with UIATS management recommendations based on a 5-point Likert scale (5 indicating strong agreement). Interrater agreement (IRA) was assessed with standardized coefficients of dispersion (v(r)*) (v(r)* 5 0 indicating excellent agreement and v(r)* = 1 indicating poor agreement). Results: The UIATS accounts for 29 key factors in UIA management. Agreement with UIATS (mean Likert scores) was 4.2 (95% confidence interval [CI] 4.1-4.3) per reviewer for both reviewer cohorts; agreement per case was 4.3 (95% CI 4.1-4.4) for panel members and 4.5 (95% CI 4.3-4.6) for external reviewers (p = 0.017). Mean Likert scores were 4.2 (95% CI 4.1-4.3) for interventional reviewers (n = 56) and 4.1 (95% CI 3.9-4.4) for noninterventional reviewers (n = 12) (p = 0.290). Overall IRA (v(r)*) for both cohorts was 0.026 (95% CI 0.019-0.033). Conclusions: This novel UIA decision guidance study captures an excellent consensus among highly informed individuals on UIA management, irrespective of their underlying specialty. Clinicians can use the UIATS as a comprehensive mechanism for indicating how a large group of specialists might manage an individual patient with a UIA.Peer reviewe