Photonic clocks, Raman lasers, and Biosensors on Silicon

Micro-resonators on silicon having Q factors as high as 500 million are described, and used to demonstrate radio-frequency mechanical oscillators, micro-Raman and parametric sources with sub-100 microwatt thresholds, visible sources, as well as high-sensitivity, biological detectors

Soft lithographic fabrication of microresonators

Using ultra-high-Q toroid microcavity masters, soft lithography is applied to fabricate polymer microcavity arrays with Q factors in excess of 10^6. This technique produces resonators with material-limited quality factors

Ultra-high-Q microcavity operation in H2O and D2O

Optical microcavities provide a possible method for boosting the detection sensitivity of biomolecules. Silica-based microcavities are important because they are readily functionalized, which enables unlabeled detection. While silica resonators have been characterized in air, nearly all molecular detections are performed in solution. Therefore, it is important to determine their performance limits in an aqueous environment. In this letter, planar microtoroid resonators are used to measure the relationship between quality factor and toroid diameter at wavelengths ranging from visible to near-IR in both H2O and D2O, and results are then compared to predictions of a numerical model. Quality factors (Q) in excess of 10^8, a factor of 100 higher than previous measurements in an aqueous environment, are observed in both H2O and D2O

Simultaneous measurement of quality factor and wavelength shift by phase shift microcavity ring down spectroscopy

Optical resonant microcavities with ultra high quality factors are widely used for biosensing. Until now, the primary method of detection has been based upon tracking the resonant wavelength shift as a function of biodetection events. One of the sources of noise in all resonant-wavelength shift measurements is the noise due to intensity fluctuations of the laser source. An alternative approach is to track the change in the quality factor of the optical cavity by using phase shift cavity ring down spectroscopy, a technique which is insensitive to the intensity fluctuations of the laser source. Here, using biotinylated microtoroid resonant cavities, we show simultaneous measurement of the quality factor and the wavelength shift by using phase shift cavity ring down spectroscopy. These measurements were performed for disassociation phase of biotin-streptavidin reaction. We found that the disassociation curves are in good agreement with the previously published results. Hence, we demonstrate not only the application of phase shift cavity ring down spectroscopy to microcavities in the liquid phase but also simultaneous measurement of the quality factor and the wavelength shift for the microcavity biosensors in the application of kinetics measurements

Seafood fraud incidents control: Histological based methods as reliable tools for fresh and frozen/thawed products discrimination

Freezing is one of the commonest methods applied for seafood shelf-life extension and long-term preservation. Nevertheless, the quality decay caused by water crystallization and cellular dehydration is responsible of significant reduction of the frozen-thawed products commercial value. Therefore, according to the European Legislation on food labelling, the declaration of freezing process represents a mandatory information for the protection of consumers’ rights. In fact, the lack of such information, besides entailing a non-conformity, can favor commercial frauds. The present work aims to present the development and validation of a histological approach, based on quali-quantitative histological markers, for the discrimination between fresh and thawed-frozen fishery products. In particular, the results of the application of the histological method on Merluccius merluccius and Octopus vulgaris, respectively selected as study models for white meat fish and cephalopods species, will be presented

Spectrometer Scan Mechanism for Encountering Jovian Orbit Trojan Asteroids

This paper describes the design, testing, and lessons learned during the development of the Lucy Ralph (L'Ralph) Scan Mirror System (SMS), composed of the Scan Mirror Mechanism (SMM), Differential Position Sensor System (DPSS) and Mechanism Control Electronics (MCE). The L'Ralph SMS evolved from the Advanced Topographic Laser Altimeter System (ATLAS) Beam Steering Mechanism (BSM), so design comparisons will be made. Lucy is scheduled to launch in October 2021, embarking upon a 12-year mission to make close range encounters in 2025 and 2033 with seven Trojan asteroids and one main belt asteroid that are within the Jovian orbit. The L'Ralph instrument is based upon the New Horizons Ralph instrument, which is a panchromatic and color visible imager and infrared spectroscopic mapper that slewed the spacecraft for imaging. The L'Ralph SMM is to provide scanning for imaging to eliminate the need to slew the spacecraft. One purpose of this paper is to gain understanding of the reasoning behind some of the design features as compared with the ATLAS BSM. We will identify similarities and differences between the ATLAS BSM and the L'Ralph SMM that resulted from the latter's unique requirements. Another purpose of this paper is to focus upon "Lessons Learned" that came about during the development of the L'Ralph SMM and its MCE, both mechanism engineering issues and solutions as well as Ground Support Equipment (GSE) issues and solutions that came about during the validation of requirements process. At the time of this writing, the L'Ralph SMM has been flight qualified and delivered to the project

An Experimental Platform for the Analysis of Polydisperse Systems Based on Light Scattering and Image Processing

In this work an experimental platform for light scattering analysis has been developed using image sensors, as CCD or CMOS. The main aim of this activity is the investigation of the feasibility of using these types of sensors for polydisperse systems analysis. The second purpose is the implementation of an experimental platform which is enough versatile to permit the observation of different phenomena in order to develop novel sensors/approach using data fusion

MR blockade protects against diet induced obesity, adipocyte dysfunction and cardiac inflammation in mice, through browning of the adipose organ and modulation of autophagy

Obesity is a key factor in the development of insulin resistance (IR), cardiovascular disease, hypertension, type 2 diabetes etc. Given the near epidemic incidence of obesity in western society there is a clear need for effective treatment options. Mineralocorticoid receptor (MR) blockade has shown significant promise in transgenic mouse models of obesity in limiting IR and adipocyte dysfunction, a disease that is independent of classical MR actions (renal). Female 10-weekold C57bl6 mice were fed with normal chow or a high fat (HF) diet for 12 weeks. Mice fed HF diet were concomitantly treated for 12 weeks with drospirenone (DRSP, 6 mg/kg/day), a potent MR antagonist with antiadipogenic activity, or spironolactone (SPIRO, 20 mg/kg/day). Mice fed HF diet showed a significant increase in total body weight, fat mass, mean adipocyte size, expression of white adipose tissue (WAT) marker genes and showed impaired glucose tolerance after intraperitoneal plasma glucose tolerance test. DRSP and SPIRO prevented weight gain and white fat mass expansion induced by HF diet in parametrial, perivescical, and inguinal depots without affecting interscapular fat pad weight. Magnetic Resonance Imaging (MRI) confirmed that MR antagonists blocked the HF dietdriven expansion of abdomino-pelvic (parametrial and perivescical) fat volume. High levels of MR mRNA were detected in all depots of adipose tissue. HF fed mice showed no increase in heart or kidney weight and tissue fibrosis. Cardiac macrophage recruitment and osteopontin staining was increased in hearts of HF fed mice and reversed by both MR antagonists. Moreover, both DRSP and SPIRO prevented the impaired glucose tolerance in mice fed HF diet, and countered HF diet-induced up-regulation of WAT markers transcripts and adipocyte hypertrophy. Importantly, MR antagonists increased uncoupling protein 1 (UCP-1) positive brown-like adipocyte content in WAT, and improved metabolic activity of adipose tissue, as indicated by PET/CT imaging. In keeping with this, MR antagonism significantly increased expression of brown-like adipocyte marker genes such PRDM16, CIDEA, beta-3 adrenergic receptor (ADRB3) and UCP-1 in all WAT depots analysed. In exploring the mechanism, we demonstrated that MR antagonism induced brown adipose tissue (BAT) markers, and reduced the autophagic rate, a key remodelling process in adipocyte differentiation, in WAT depots in vivo as well as in primary cultured adipocytes. We conclude that adipocyte MR regulates BAT-like remodeling of WAT through modulation of autophagy. MR blockade therefore has promise as a novel therapeutic option for the prevention of metabolic dysfunctions and the cardiac consequences of obesity. doi:10.1016/j.ijcme.2015.05.012 Transcriptional control of ICAM-1 in human coronary artery endothelial cells by Mineralocorticoid Receptor (MR): Implications for the protective effects of MR antagonists in cardiovascular diseases V. Marzolla, A. Armani, A. Fabbri, I.Z. Jaffe, M. Caprio Laboratory of Cardiovascular Endocrinology, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) San Raffaele Pisana, Rome, Italy Department of Medicina dei Sistemi, Endocrinology Unit, S. Eugenio & CTO A. Alesini Hospitals, University Tor Vergata, Rome, Italy Molecular Cardiology Research Institute, Tufts Medical Center, Boston