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Bioresorbable polymeric materials have risen great interest as implants for bone tissue regeneration, since they show substantial advantages with respect to conventional metal devices, including biodegradability, flexibility, and the possibility to be easily modified to introduce specific functionalities. In the present work, an innovative nanocomposite scaffold, properly designed to show biomimetic and osteoinductive properties for potential application in bone tissue engineering, was developed. The scaffold is characterized by a multi-layer structure, completely different with respect to the so far employed polymeric implants, consisting in a poly(D,L-lactide-co-glycolide)/polyethylene glycol electrospun nanofibrous mat sandwiched between two hydrogel gelatin layers enriched with tantalum nanoparticles (NPs). The composition of the electrospun fibers, containing 10 wt% of polyethylene glycol, was selected to ensure a proper integration of the fibers in the gel phase, essential to endow the composite with flexibility and to prevent delamination between the layers. The scaffold maintained its structural integrity after six weeks of soaking in physiological solutions, albeit the gelatin phase was partially released. The combined use of gelatin, bioresorbable electrospun fibers and tantalum NPs endows the final device with biomimetic and osteoinductive properties. Indeed, results of the in vitro tests demonstrate that the obtained scaffolds clearly represent a favorable milieu for normal human bone-marrow derived mesenchymal stem cells viability and osteoblastic differentiation; moreover, inclusion of tantalum NPs in the scaffold improves cell performance with particular regard to early and late markers of osteoblastic differentiation. (C) 2022 Elsevier Ltd. All rights reserved.

In this article, we present TeraPHY, a monolithic electronic–photonic chiplet technology for low power and low latency, multi-Tb/s chip-to-chip communications. Integration of the TeraPHY optical technology with open source advanced interconnect bus interface enables communication between chips at board, rack, and row level at the energy and latency cost of in-package interconnect. This enables the design of logically connected but physically separated large-scale and high-performance digital systems. The copackaging integration approach is demonstrated by integrating the TeraPHY die into the Intel Stratix10 FPGA multichip package.

Recently, an advanced experimental procedure has been proposed to highlight the close relationship existing between structure and function in fibrous materials [1], specifically focusing on Anterior Cruciate Ligament (ACL) tissue. A micro-CT system embedding a custom tensioning device was specifically used to acquire the fibrous tissue volume at the micro-scale, considering several levels of strain (i.e. 0÷8%); a biochemical contrasting process optimized fiber visualization and tissue mechanics preservation. After those experimental acquisition sessions [1], this study focused on image data processing and analysis, to identify “fiber” objects, hereinafter called fibers, and estimate mechanical properties, including their mean elastic modulus.

The objective of this study was to analyze associated factor to SARS-CoV-2 infection among dental professionals. This was a cross-sectional study carried out from February to September 2020 in the municipality of São Paulo, Brazil. We included all dental team working at 11 basic health units. Professionals included were from the three different categories oral surgeon-dentist, dental technician, dental assistant. The analysis included SARS-CoV-2 infection and independent variables (sociodemographic, labor and behavior) with descriptive analyses with absolute (n) and relative (%) frequencies, inferential analysis by chi-squared and Fisher exact test (p < 0.05). There was a prevalence of 20.3% of infection by SARS-CoV-2 between dental professionals. However, in the analysis by professional category the infection rate was 3.8 among oral surgeon-dentist, 30.0% among dental technician, 33.3% for dental assistant. The diagnostic of SARS-CoV-2 infection was associated with lower income (p = 0.027), lower level of formal education (p = 0.011), technical professional category (p = 0.025), and the use of public transportation (p = 0.009). The higher prevalence of COVID-19 in technical professionals than oral surgeon-dentists may suggest that infection had occurred outside the working environment, once professional had personal protective equipment available as well as the training for their professional activity. In addition, professionals reported to feel safe and prepared to perform their activities in the work environment. Key messages Transmission of SARS-CoV-2 in oral health in the public service. Promotion and prevention of SARS-CoV-2 transmission in oral health in the public service.

For the first time, we demonstrate an error-free, 128Gbps (8x16Gbps) optical transceiver using a microring-based wavelength-division multiplexed (WDM) architecture. The optical transceiver ran for 12 hours with zero errors, resulting in a measured bit-error rate of

This study aimed to analyse the changes given by different levels of strain in the 3D microstructure of a fibrous soft tissue by using a microtomography system (micro-CT, Bruker Skyscan 1176) integrated with a custom-made tensioning device. Without loss of generality, the proposed approach was applied to the Anterior Cruciate Ligament. Two different samples were specifically analysed: a cadaveric tissue harvested by a healthy donor and a specimen obtained by a patient, who underwent total knee arthroplasty. Analysis was carried out by means of standard microtomographic procedures and focused on fiber orientation and stress-strain characteristic. Findings highlighted a clear difference in terms of fibrous density and arrangement between the two specimens. Besides providing proper mechanomicrostructural fingerprints for each human ligament/tendon and increasing the understanding on the effects of osteoarthritis on joint soft tissues, this approach can be useful also in tissue engineering, since it suggests correlation between tissue arrangements and mechanical behaviour

We demonstrate a 75 µm-long rapid adiabatic coupler (RAC) with an average insertion loss <0.025 dB/coupler and an average power splitting ratio of 50±1.09% over 40 nm bandwidth and 68 reticles across a 300 mm 45 nm SOI CMOS wafer.

We demonstrate a rapid adiabatic coupler (RAC) with 50±1.08% power splitting ratio over 100 nm and insertion loss

We demonstrate 128 Gbps/port (8-λ × 16 Gbps/λ) natively error-free transmission across eight optical ports using a 8-port, 8-λ/port WDM remote laser source and a pair of monolithically integrated CMOS optical I/O chiplets with 4.96-5.56 pJ/bit optical Tx+Rx chiplet energy efficiency.

We present a SiGe resonant photodetector fabricated in commercial 45 nm SOI CMOS with a 3-dB bandwidth of 17.8 GHz, the highest reported for such devices. This is achieved by using high doping concentrations to reduce the resistance of the regions accessing the active area.

We demonstrate an electro-optic platform enabling a direct optical I/O interface in an ASIC package. The $5.5\mathrm{x}8.9\mathrm{mm}^{2}$ chiplet uses the Advanced Interface Bus (AIB), a parallel digital interface, to communicate to a host ASIC and integrates high-speed digital/analog circuits, optical modulators, photodetectors, and waveguides. Transmitters and receivers demonstrate data-rates up to 25Gbps at 4.9pJ/bit (Tx+Rx) and −12 BER error-free operation. We show a 32-channel, 512Gbps aggregate (across 4 Tx ports) wavelength-division multiplexed (WDM) transmit demonstration from a TeraPHY chiplet, running at 16Gbps per wavelength and 8 simultaneous wavelengths per port.

Background: In a globally aging population, chronic conditions with a high impact on healthcare costs and quality of life, such as osteoporosis and associated fractures, are a matter of concern. For osteoporosis, several drug treatments are available, but evidence on adverse cardiovascular and cerebrovascular (CCV) events, and in particular the risk of atrial fibrillation (AF), related to anti-osteoporotic drug use is inconclusive. The objective of this study was to evaluate the association between the use of bisphosphonates (BPs), strontium ranelate (SR), and other anti-osteoporosis drugs and the risk of AF and CCV events in a large cohort of patients affected by CCV diseases. Methods: Based on a cohort of patients aged 65 years and over, discharged from the hospitals of five large Italian areas after a CCV event between 2008 and 2011, two nested case-control studies were conducted. Cases were patients with a subsequent hospital admission for AF or CCV; four controls for each case were randomly selected and matched by age group, sex and follow-up time. A total of three exposure measures were tested: ever use, adherence and recency of use. In the conditional logistic regression models, patients not treated with any anti-osteoporotic medication were considered as the reference category. Results: The initial cohort accounted for 657,246 patients. Neither BPs nor SR use was associated with an increased risk of AF regardless of the adherence and recency of use. Overall BP and SR use was associated with a slightly increased risk of CCV; however, results reversed when considering higher adherence: odds ratio (OR) 0.81, 95% confidence interval (CI) 0.71-0.92 for BPs and OR 0.71, 95% CI 0.52-0.97 for SR. Conclusions: BPs do not increase cardiovascular risk and can be prescribed to elderly patients for osteoporosis treatment. However, patients with pre-existing cerebrovascular/cardiovascular conditions should be carefully monitored.

We report high-speed performance for a photodetector operating at zero bias—with zero dark current and zero DC electrical power dissipation. Photocurrent generation is achieved through phonon-assisted absorption in a silicon microring resonator embedded with silicon-germanium, resulting in a responsivity of 0.35 and 0.043 A/W at wavelengths around 1180 and 1270 nm, respectively. We measure a 3 dB bandwidth of 14 GHz, the fastest reported to date for a zero-biased ring-resonant photodetector and which represents a 7× improvement with respect to previous work. We explore the source of such improvement through TCAD simulations and conclude that the optimization of the doping profile significantly decreases the effective carrier lifetime by limiting the impact of the photogenerated carriers drifting into the outer circumference of the resonator, with a low electric field. Using experimental data, we also extract both the free carrier and the phonon-assisted silicon-germanium absorption coefficient, showing good agreement with literature data. High-speed operation at temperatures up to 150 °C is also demonstrated.

In this work, we provide an overview of System-in-Package (SiP) integration of an electronic-photonic chiplet fabricated in a commercial CMOS foundry. Assembly considerations, including co-packaging in a standard multi-chip module (MCM) package with a System-on-Chip (SoC), thermals, and fiber attach will be reviewed.

We present a high bandwidth-density photonic interconnect platform that transmits 1.05 Tbps/mm2 using 0.83 pJ/bit, integrated in a 45nm SOI process, and a high-density multi-wavelength laser source.

For the first time, we successfully demonstrate the transmission of commercial 10- and 100-Gb/s interfaces, both direct detect and coherent, over 2.75 km of hollow-core fiber. The fiber is connected to the transceivers using spliced standard single-mode pigtails. This demonstration solidifies the commercial potential for low latency applications.

We report on the recent development of multicore fiber amplifiers suitable for amplifying space division multiplexed signals. We have constructed 7-core amplifiers, where the cores could be pumped individually or simultaneously through the cladding, and studied the amplification and noise properties of these amplifiers. In the core-pumped amplifier, the net average gain was 25 dB, and noise figure was less than 4 dB. Using side-coupled cladding pumping, gain over 25 dB was obtained in each of the cores over a 40-nm bandwidth covering the C-band. We have further studied numerically the amplification and noise properties of a few-moded single/multicore erbium doped fiber amplifier with a doped region that extends beyond the few-mode core. We show that when excited by a multimoded pump, this can provide nearly uniform gain in C-band for modes such as, LP01, LP11, LP21, and LP02 over a wide range of pump power. Differential modal gain (DMG) between LP01, and LP02 was ~ 0.5 dB for a small signal gain of 32 dB at 1550 nm signal wavelength. The dependence of modal gain on the size of the doped core has also been studied.

Magnetic scaffolds have recently attracted significant attention in tissue engineering due to the prospect of improving bone tissue formation by conveying soluble factors such as growth factors, hormones, and polypeptides directly to the site of implantation, as well as to the possibility of improving implant fixation and stability. The objective of this study was to compare bone tissue formation in a preclinical rabbit model of critical femoral defect treated either with a hydroxyapatite (HA)/magnetite (90/10 wt %) or pure HA porous scaffolds at 4 and 12 weeks after implantation. The biocompatibility and osteogenic activity of the novel magnetic constructs was assessed with analysis of the amount of newly formed bone tissue and its nanomechanical properties. The osteoconductive properties of the pure HA were confirmed. The HA/magnetite scaffold was able to induce and support bone tissue formation at both experimental time points without adverse tissue reactions. Biomechanically, similar properties were obtained from nanoindentation analysis of bone formed following implantation of magnetic and control scaffolds. The results indicate that the osteoconductive properties of an HA scaffold are maintained following inclusion of a magnetic component. These provide a basis for future studies investigating the potential benefit in tissue engineering of applying magnetic stimuli to enhance bone formation. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 546-554, 2018.

Hereditary spastic paraplegia (HSP) refers to a group of genetically heterogeneous neurodegenerative motor neuron disorders characterized by progressive age-dependent loss of corticospinal motor tract function, lower limb spasticity, and weakness. Recent clinical use of next generation sequencing (NGS) methodologies suggests that they facilitate the diagnostic approach to HSP, but the power of NGS as a first-tier diagnostic procedure is unclear. The larger-than-expected genetic heterogeneity—there are over 80 potential disease-associated genes—and frequent overlap with other clinical conditions affecting the motor system make a molecular diagnosis in HSP cumbersome and time consuming. In a single-center, cross-sectional study, spanning 4 years, 239 subjects with a clinical diagnosis of HSP underwent molecular screening of a large set of genes, using two different customized NGS panels. The latest version of our targeted sequencing panel (SpastiSure3.0) comprises 118 genes known to be associated with HSP. Using an in-house validated bioinformatics pipeline and several in silico tools to predict mutation pathogenicity, we obtained a positive diagnostic yield of 29% (70/239), whereas variants of unknown significance (VUS) were found in 86 patients (36%), and 83 cases remained unsolved. This study is among the largest screenings of consecutive HSP index cases enrolled in real-life clinical-diagnostic settings. Its results corroborate NGS as a modern, first-step procedure for molecular diagnosis of HSP. It also disclosed a significant number of new mutations in ultra-rare genes, expanding the clinical spectrum, and genetic landscape of HSP, at least in Italy. © Copyright © 2018 D'Amore, Tessa, Casali, Dotti, Filla, Silvestri, Antenora, Astrea, Barghigiani, Battini, Battisti, Bruno, Cereda, Dato, Di Iorio, Donadio, Felicori, Fini, Fiorillo, Gallone, Gemignani, Gigli, Graziano, Guerrini, Gurrieri, Kariminejad, Lieto, Marques LourenḈo, Malandrini, Mandich, Marcotulli, Mari, Massacesi, Melone, Mignarri, Milone, Musumeci, Pegoraro, Perna, Petrucci, Pini, Pochiero, Pons, Ricca, Rossi, Seri, Stanzial, Tinelli, Toscano, Valente, Federico, Rubegni and Santorelli.

Bergamot polyphenolic fraction (BPF) has been shown to positively modulate several mechanisms involved in metabolic syndrome, suggesting its use in therapy. In particular, it is able to induce a significant amelioration of serum lipid profile in hyperlipemic patients at different levels. The purpose of our study was to investigate the effect of BPF on cholesterol absorption physiologically mediated by pancreatic cholesterol ester hydrolase (pCEH). An in vitro activity assay was performed to study the effect of BPF on pCEH, whereas the rate of cholesterol absorption was evaluated through in vivo studies. In particular, male, Sprague-Dawley rats (200–225 g) were fed either normal chow or chow supplemented with 0.5% cholic acid, 5.5% peanut oil, and varying amounts of cholesterol (0 to 1.5%). BPF (10 mg/Kg) was daily administrated by means of a gastric gavage to animals fed with lipid supplemented diet for 4 weeks and, at the end of the study, plasma lipids and liver cholesteryl esters were measured in all experimental groups. Our results show that BPF was able to inhibit pCEH activity and this effect was confirmed, in vivo, via detection of lymphatic cholesteryl ester in rats fed with a cholesterol-rich diet. This evidence clarifies a further mechanism responsible for the hypolipemic properties of BPF previously observed in humans, confirming its beneficial effect in the therapy of hypercholesterolemia and in the treatment of metabolic syndrome.

We report on the recent development of multicore fiber amplifiers suitable for amplifying space division multiplexed signals. We designed and constructed 7-core amplifiers, where the cores could be pumped individually or simultaneously through the cladding and studied the amplification and noise properties of these amplifiers. In the core-pumped amplifier, the net average gain was 25 dB, and noise figure was less than 4 dB. Using side-coupled cladding pumping, gain over 25 dB was obtained in each of the cores over a 40-nm bandwidth covering the C-band. We present results of numerical simulation that shows ways of further improvement of amplifier performance, including gain, noise figure, and power conversion efficiency (PCE) through optimization of fiber design.

We report a two-span, 67-km space-division-multiplexed (SDM) wavelength-division-multiplexed (WDM) system incorporating the first reconfigurable optical add-drop multiplexer (ROADM) supporting spatial superchannels and the first cladding-pumped multicore erbium-doped fiber amplifier directly spliced to multicore transmission fiber. The ROADM subsystem utilizes two conventional 1 × 20 wavelength selective switches (WSS) each configured to implement a 7 × (1 × 2) WSS. ROADM performance tests indicate that the subchannel insertion losses, attenuation accuracies, and passband widths are well matched to each other and show no significant penalty, compared to the conventional operating mode for the WSS. For 6 × 40 × 128-Gb/s SDM-WDM polarization-multiplexed quadrature phase-shift-keyed (PM-QPSK) transmission on 50 GHz spacing, optical signal-to-noise ratio penalties are less than 1.6 dB in Add, Drop, and Express paths. In addition, we demonstrate the feasibility of utilizing joint signal processing of subchannels in this two-span, ROADM system.

Optical communications technology has made enormous and steady progress for several decades, providing the key resource in our increasingly information-driven society and economy. Much of this progress has been in finding innovative ways to increase the data carrying capacity of a single optical fibre. In this search, researchers have explored (and close to maximally exploited) every available degree of freedom, and even commercial systems now utilize multiplexing in time, wavelength, polarization, and phase to speed more information through the fibre infrastructure. Conspicuously, one potentially enormous source of improvement has however been left untapped in these systems: fibres can easily support hundreds of spatial modes, but today's commercial systems (single-mode or multi-mode) make no attempt to use these as parallel channels for independent signals., to appear in Nature Photonics

We discuss the advantages of spatial superchannels for future terabit networks based on space-division multiplexing (SDM), and demonstrate reception of spatial superchannels by a coherent receiver utilizing joint digital signal processing (DSP). In a spatial superchannel, the SDM modes at a given wavelength are routed together, allowing a simplified design of both transponders and optical routing equipment. For example, common-mode impairments can be exploited to streamline the receiver's DSP. Our laboratory measurements reveal that the phase fluctuations between the cores of a multicore fiber are strongly correlated, and therefore constitute such a common-mode impairment. We implement master-slave phase recovery of two simultaneous 112-Gbps subchannels in a seven-core fiber, demonstrating reduced processing complexity with no increase in the bit-error ratio. Furthermore, we investigate the feasibility of applying this technique to subchannels carried on separate single-mode fibers, a potential transition strategy to evolve today's fiber networks toward future networks using multicore fibers.

Statistical models for the accumulation of crosstalk in multicore fibers are extended to include time-varying signals and relative delays. Crosstalk is thus described as multiple delayed copies of the signal with uncorrelated phase. A simple model of an equalized channel suggests that independent degrees of freedom are required to cancel each of the many delayed copies, resulting in an unfavorable scaling of the equalizer complexity.

We describe a new multicore fiber (MCF) having seven single-mode cores arranged in a hexagonal array, exhibiting low crosstalk among them and low loss across the C- and L-band. In order to spatially multiplex and demultiplex optical signals in and out of the MCF, we designed and fabricated a tapered MCF connector (TMC) with ultralow crosstalk and loss for space-division-multiplexing (SDM) transmission. The key crosstalk properties of MCF, including wavelength and distance dependence crosstalk characteristics, and statistical distribution of crosstalk over time, are measured and discussed. Using the MCF and TMC, we experimentally demonstrate a record transmission capacity of 112 Tb/s over a 76.8 km MCF using SDM and dense wavelength division multiplexing. Each core of the MCF carries 160 107 Gb/s polarization-division multiplexed quadrature phase-shift keying (PDM-QPSK) channels on a 50 GHz grid in the C- and L-band, resulting in an aggregate spectral efficiency of 14 b/s/Hz. The system impact of the intercore crosstalk on a 107 Gb/s PDM-QPSK signal is further investigated by transmitting it through the center core while the six outer cores carry same-wavelength 107 Gb/s signals. The system implication of the core-to-core crosstalk on ultralong-haul transmission is also discussed.

Summary: In a longitudinal study one healthy man aged 26 yrs underwent semen collections and blood samplings at monthly interval from January to December 1985. The ejaculated samples were analyzed for sperm density, motility, relative proportion of early (ab) and late (cd) spermatids, concentrations of Fructose, L-Carnitine and Transferrin. In a transverse study, 248 serially independent samplings were performed of normal men, 28.9 ± 7.5 yrs old, consulting for infertility from January 1981 to December 1983. The Cosinor method was employed for searching on circannual rhythms of the studied parameters. The longitudinal study did not detect circannual rhythms of the considered seminal parameters nor of the studied hormones. However, peaks, significantly above the mean values throughout the year (p < 0.005), were observed of Cortisol, PRL, FSH, LH, Testosterone, Fructose and L-Carnitine levels. Young spermatids and sperm motility showed significant (p < 0.001) acrophases between June and July; an acrophase was also evident for late spermatids but shifted by six months, between December and January. Mesors and amplitudes were respectively: 28 ± 1.5 and 9.6 ± 43 (mean ± SE) for motility; 33.4 ± 1.6 and 9.9 ±5 for early spermatids; 46.6 ±1.9 and 13 ± 6.2 for late spermatids. Zusammenfassung: Jahreszeitliche Schwankungen der reproduktiven Funktionen von Mannern Korrelation von Hormonen und hormonabhangigen Parametern In einer Longitudinalstudie eines 26jahrigen gesunden Mannes wur-den in monatlichen Intervallen von Januar bis Dezember 1985 Ejakulate und Blutproben gewonnen. Die Ejakulate wurden auf Spermatozoendichte, -motilitat, relativen Anteil von fruhen und spaten Spermatiden und Fruktose-, L-Carnitin- und Transferrinkonzentration unter-sucht. In einer transversalen Studie wurden 248 unabhangige Serienuntersuchungen von nor-malen Mannern durchgefuhrt. Die Manner waren durchschnittlich 28,9 ±7,5 Jahre alt und wurden in dem Zeitraum von Januar 1981 bis Dezember 1983 wegen Infertilitat unter-sucht. Um jahreszeitliche Schwankungen der untersuchten Parameter herauszufinden, wur-de die Methode nach Cosinor angewandt. Die Longitudinalstudie ergab keine jahreszeitlichen Schwankungen fur die Spermio-grammparameter und die untersuchten Hormone. Es wurden jedoch uber das ganze Jahr verteilt, signifikant uber den Normalwerten liegende Spitzenwerte (p < 0,005) fur Corti-sol, PRL, FSH, LH, Testosteron, Fruktose und L-Carnitin gefunden. Fur die fruhen Spermatiden und die Spermatozoenmotilitat ergaben sich signifikante (p < 0,001) Phasen mit Spitzenwerten zwischen Juni und Juli; ahnliche Phasen waren fur die spaten Spermatiden allerdings um 6 Monate verschoben zwischen Dezember und Ja-nuar erkennbar. Die Messungen bzw. Amplituden im einzelnen ergaben: 28 ± 1,5 und 9,6 ± 4,3 (Mittel ± SE) fur die Motilitat; 33,4 ± 1,6 und 9,9 ± 5 fur die fruhen Spermatiden; 46,6 ±1,9 und 13 ± 6,2 fur die spaten Spermatiden.

Diffraction-limited fundamental mode amplification is demonstrated in Er-doped fibers with mode areas ranging from 900 to 1800 mum2. The amplifiers are core-pumped with Raman fiber lasers with both signal and pump selectively launched into the fundamental mode. This scheme results in differential gain for the fundamental mode and stabilizes it against mode mixing caused by perturbations in the core. Gains that are greater than 30 dB are demonstrated from a single stage without significant amplified spontaneous emission. The low nonlinearity of the large mode areas enables amplification to high peak powers without resorting to unconventional microstructured or higher order mode fibers.

Spatially and spectrally resolved imaging of mode content in fibers, or more simply, S2 imaging, is a new measurement technique for analyzing the mode content of large-mode-area (LMA) fibers. It works by spatially resolving the spectral interference that occurs when light in a few-mode fibers scatters into different modes that then propagate with different group delays. A scanning spatial filter in the form of a single-mode fiber probe coupled to an optical spectrum analyzer is utilized to provide both spatial and spectral resolution, and the data are analyzed via the Fourier transform of the optical spectrum. The wealth of data allows for imaging multiple modes simultaneously propagating in the fiber under test as well as quantifying their relative power levels. In addition, the ability to analyze mode images as a function of modal group delay allows distinguishing between discrete scattering at fiber surfaces and distributed scattering that occurs along the length of the LMA fiber. The all-fiber nature of the setup makes the measurement sufficiently stable to measure phase images of the higher order modes (HOMs). Because the method is interferometrically based, even very weak HOMs can be detected.

This paper describes the physics and properties of a novel optical fiber that would be attractive for building high-power fiber lasers and amplifiers. Instead of propagating light in the fundamental, Gaussian-shaped mode, we describe a fiber in which the signal is forced to travel in a single, desired higher order mode (HOM). This provides for several advantages over the conventional approach, ranging from significantly higher ability to scale mode areas (and hence laser powers) to managing dispersion for ultra-short pulses - a capability that is practically nonexistent in conventional fibers. Particularly interesting is the tact that this approach challenges conventional wisdom, and demonstrates that for applications requiring meter-length fibers (as in high-power lasers), signal stability actually increases with mode order. Using this approach, we demonstrate mode areas exceeding 3200 μm 2 , and propagate signals with negligible mode distortions over up to 50-meter lengths. We describe several pulse propagation experiments in which we test the nonlinear response of this fiber platform, ranging from managing dispersive effects in femtosecond pulse systems, to reducing Brillouin scattering impairments in systems operating with the nanosecond pulses.

Objective Diabetic patients have a reduced endothelial response to phosphodiesterase-5 inhibitors. The aim of this study was to determine the effects of chronic therapy with sildenafil on endothelial function in patients with Type 2 diabetes mellitus (DM2). Methods In a double-blind, placebo-controlled parallel design, 20 patients without erectile dysfunction randomly received a loading dose of sildenafil (100 mg) for 3 days, followed by either sildenafil 25 mg three times a day (t.d.s.) for 4 weeks or sildenafil 25 mg t.d.s. for 4 days followed by placebo t.d.s. for 3 weeks. Results After 1 week, flow-mediated dilatation (FMD) improved significantly (> 50% compared with baseline) in patients allocated to both sildenafil arms (62 and 64%, respectively). In patients allocated to chronic sildenafil, a progressive increase in percentage of patients with FMD improvement was noted (78, 86 and 94% at 2, 3 and 4 weeks, respectively) while a progressive decrease in the placebo group occurred (45, 18 and 6% at 2, 3 and 4 weeks, respectively). At the end of the study, a significant improvement in FMD compared with baseline was noted after chronic sildenafil (FMD from 6.8 ± 0.5 to 12.5 ± 0.7%, P = 0.01 vs. baseline). A decrease in endothelin-1 levels and an increase in nitrite/nitrate levels were found after chronic sildenafil; significant changes from baseline in C-reactive protein, interleukin 6, intercellular adhesion molecule and vascular adhesion molecule levels were also found. Conclusions In DM2 patients, daily sildenafil administration improves endothelial function and reduces markers of vascular inflammation, suggesting that the diabetes-induced impairment of endothelial function may be improved by prolonged phosphodiesterase-5 inhibition. Diabet. Med. 25, 37–44 (2008)

In orthopaedic surgery the tissues damaged by injury or disease could be replaced using constructs based on biocompatible materials, cells and growth factors. Scaffold design, porosity and early colonization are key components for the implant success. From biological point of view, attention may be also given to the number, type and size of seeded cells, as well as the seeding technique and cell morphological and volumetric alterations. This paper describes the use of the microCT approach (to date used principally for mineralized matrix quantification) to observe construct colonization in terms of cell localization, and make a direct comparison of the microtomographic sections with scanning electron microscopy images and confocal laser scanning microscope analysis. Briefly, polycaprolactone scaffolds were seeded at different cell densities with MG63 osteoblastic-like cells. Two different endpoints, 1 and 2 weeks, were selected for the three-dimensional colonization and proliferation analysis of the cells. By observing all images obtained, in addition to a more extensive distribution of cells on scaffolds surfaces than in the deeper layers, cell volume increased at 2 weeks compared to 1 week after seeding. Combining the cell number quantification by deoxyribonucleic acid analysis and the single cell volume changes by confocal laser scanning microscope, we validated the microCT segmentation method by finding no statistical differences in the evaluation of the cell volume fraction of the scaffold. Furthermore, the morphological results of this study suggest that an effective scaffold colonization requires a precise balance between different factors, such as number, type and size of seeded cells in addition to scaffold porosity.

A hollow-core fibre with six shunt cores demonstrates complete higher order core mode attenuation in less than 0.5m, without affecting loss or PM properties when compared with a fibre with two shunt cores.