Optical time domain reflectometry (OTDR) is a key technique to characterize fabricated and installed optical fibers. It is also widely used in distributed sensing. OTDR of emerging hollow-core fibers (HCFs) has been demonstrated only very recently, being almost 30 dB weaker than that in the glass-core optical fibers.
View Article and Find Full Text PDFA main, yet-unsolved challenge in splicing hollow-core fiber (HCF) into standard single-mode fiber (SMF) systems lies in managing the strong Fresnel back-reflection that occurs when the light travels from the empty core of the HCF into the glass core of the SMF or vice versa. This impacts the performance of fiber systems that combine SMFs and HCFs due to effects such as multipath interference. Here, we demonstrate a new technique that combines angle-cleaving the HCF, which reduces the back-reflection, with offset-splicing the mode-field adapter to the SMF, which compensates for the refraction at the glass-air interface, enabling us to achieve low coupling loss.
View Article and Find Full Text PDFPlacing dental implants in microvascular bone free flaps used for reconstructing the mandible or maxilla has been previously reported. However, there is scarce information available on the restorative protocol using short dental implants placed in a (DCIA) microvascular free flap and the rationale behind it. This case report describes a 18-year-old patient referred to the hospital for numbness and dull pain of the left mandible, which she observed for three months.
View Article and Find Full Text PDFLasers stabilized to optical fiber delay lines have been shown to deliver a comparable short-term (<1 s) frequency noise performance to that achieved by lasers stabilized to ultra-low expansion (ULE) cavities, once the linear frequency drift has been removed. However, for continuous stable laser operations, the drift can be removed only when it can be predicted, e.g.
View Article and Find Full Text PDFThere is limited information regarding implant and prosthetic survival after osseous microvascular free flap (OMFF). This case series aims to describe the placement of short and extra short implants in osseous microvascular free flaps to support prostheses, and present an up to 40-month retrospective follow-up. Short and extra short dental implants were placed in six fibula free flaps (FFF) and in two microvascular deep circumflex iliac artery (DCIA) flaps.
View Article and Find Full Text PDFLight Sci Appl
November 2023
Recently, significant efforts have been devoted to enable light resonating inside various resonators for long time, leading to high Q factors. Achieving tunability of the free spectral range while maintaining high Q has been, however, challenging.
View Article and Find Full Text PDFVentricular arrhythmias (VAs) in heart failure are enhanced by sympathoexcitation. However, radiotracer studies of catecholamine uptake in failing human hearts demonstrate a proclivity for VAs in patients with reduced cardiac sympathetic innervation. We hypothesized that this counterintuitive finding is explained by heterogeneous loss of sympathetic nerves in the failing heart.
View Article and Find Full Text PDFRadionuclide therapy targeting prostate-specific membrane antigen (PSMA) is a promising option for metastatic castration-resistant prostate cancer. Clinical experience using Lu or Ac has demonstrated encouraging treatment responses; however, responses are not durable. Dual-isotope combinations, or "tandem" approaches, may improve tolerability while retaining a high tumor dose.
View Article and Find Full Text PDFAims: The aim of this study is to retrospectively evaluate the use of a transconjunctival surgical approach in maxillofacial surgery on the fractures of the infraorbital rim and the orbital floor by analyzing the operating time, the incidence of perioperative and postoperative complications, as well as the functional and aesthetic outcomes of transconjunctival surgical treatment.
Materials And Methods: All the patients on whom we used a transconjunctival approach from December 2017 to December 2021 were included in this retrospective study. The epidemiological causes of fractures of the midface skeleton were analyzed.
Fast (nanoseconds) optical wavelength switching is emerging as a viable solution to scaling the size and capacity of intra-data center interconnection. A key enabling technology for such systems is low-jitter optical clock synchronization, which enables sub-nanosecond clock and data recovery for optically switched frames using low-cost methods such as clock phase caching. We propose and demonstrate real-time low-latency wavelength-switched clock-synchronized intra-data center interconnection at 51.
View Article and Find Full Text PDFIn the original publication of our research article "Hollow core fiber Fabry-Perot interferometers with reduced sensitivity to temperature" [Opt. Lett.47, 2510 (2022)10.
View Article and Find Full Text PDFBy modifying the interconnection design between standard single-mode fiber (SSMF) and nested antiresonant nodeless type hollow-core fiber (NANF), we create an air gap between SSMF and NANF. This air gap enables the insertion of optical elements, thus providing additional functions. We show low-loss coupling using various graded-index multimode fibers acting as mode-field adapters resulting in different air-gap distances.
View Article and Find Full Text PDFOptical fibers with a low thermal coefficient of delay (TCD) have been developed for frequency and timing transmission/distribution. However, their temperature sensitivity changes as a function of temperature and, to date, no study of such fibers has demonstrated improved performance over extended temperature ranges, especially at sub-zero temperatures. Here, we show that a hollow core fiber (HCF) with a thin acrylate coating can have a TCD within ±2.
View Article and Find Full Text PDFWe report simultaneous low coupling loss (below 0.2 dB at 1550 nm) and low back-reflection (below -60 dB in the 1200-1600 nm range) between a hollow core fiber and standard single mode optical fiber obtained through the combination of an angled interface and an anti-reflective coating. We perform experimental optimization of the interface angle to achieve the best combination of performance in terms of the coupling loss and back-reflection suppression.
View Article and Find Full Text PDFToday's lowest-loss hollow core fibers are based on antiresonance guidance. They have been shown both theoretically and experimentally to have very low levels of backscattering arising from the fiber structure - 45 dB below that of traditional optical fibers with a solid silica glass core. This makes their longitudinal characterization using conventional reflectometric techniques very challenging.
View Article and Find Full Text PDFThere are a host of applications in communications, sensing, and science, in which analogue signal transmission is preferred over today's dominant digital transmission. In some of these applications, the advantage is in lower cost, while in others, it lies in superior performance. However, especially for longer analogue photonics links (up to 10 s of km), the performance is strongly limited by the impairments arising from using standard single-mode fibres (SSMF).
View Article and Find Full Text PDFWe demonstrate a 3× thermal phase sensitivity reduction for a hollow-core fiber (HCF) Fabry-Perot interferometer by winding the already low temperature sensitivity HCF on to a spool made from an ultralow thermal expansion material. A record low room temperature fiber coil phase thermal sensitivity of 0.13 ppm/K is demonstrated.
View Article and Find Full Text PDFFibroblast activation protein (FAP)-expressing cancer-associated fibroblasts confer treatment resistance and promote metastasis and immunosuppression. Because FAP is overexpressed in many cancers, radiolabeled molecules targeting FAP are studied for their use as pancancer theranostic agents. This study aimed to establish the spectrum of FAP expression across various cancers by immunohistochemistry and to explore whether Ga FAP inhibitor (FAPi)-46 PET biodistribution faithfully reflects FAP expression from resected cancer and non-cancer specimens.
View Article and Find Full Text PDFThe optical phase accumulated when light propagates through an optical fiber changes with temperature. It has been shown by various authors that this thermal phase sensitivity is significantly smaller in hollow core fibers (HCFs) than in standard single-mode fibers (SSMFs). However, there have been considerable differences in the level of sensitivity reduction claimed, with factors in the range ×3 to ×20 improvement for HCFs relative to SSMFs reported.
View Article and Find Full Text PDFmRNA-based COVID-19 vaccines such as BNT162b2 have recently been a target of anti-vaccination campaigns due to their novelty in the healthcare industry; nevertheless, these vaccines have exhibited excellent results in terms of efficacy and safety. As a consequence, they acquired the first approvals from drug regulators and were deployed at a large scale among priority groups, including healthcare workers. This phase IV study was designed as a nationwide cross-sectional survey to evaluate the post-vaccination side effects among healthcare workers in Slovakia.
View Article and Find Full Text PDFThe objective of this study was to determine prospectively the efficacy profile of 2 activity regimens of Lu-PSMA therapy in patients with progressive metastatic castrate-resistant prostate cancer (mCRPC): 6.0 vs. 7.
View Article and Find Full Text PDFWe demonstrate halving the record-low loss of interconnection between a nested antiresonant nodeless type hollow-core fiber (NANF) and standard single-mode fiber (SMF). The achieved interconnection loss of 0.15 dB is only 0.
View Article and Find Full Text PDFBackground: The critically ill patients suffering from coronavirus disease (COVID-19) and admitted to the intensive care units (ICUs) are susceptible to a wide array of complications that can be life-threatening or impose them to long-term complications. The COVID-19 oral mucocutaneous complications require multidisciplinary management and research for their pathophysiological course and epidemiological significance; therefore, the objective of this study was to evaluate the prevalence and characteristics of the critically ill COVID-19 patients with oral complications.
Methods: We described the clinical and microbiological characteristics of the critically ill COVID-19 patients in our ICU department (Banska Bystrica, Slovakia).
Background Hospital pharmacy audit and feedback of 'do not use' medication abbreviations improves patient safety. For audit and feedback systems to be effective, the data captured must be of high quality such that end-users trust the information to guide practice change. The quality of data captured during monthly standardized pharmacy 'do not use' abbreviation audits is currently unknown.
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