Third-order Optical Nonlinearities for Integrated Microwave Photonics Applications

The field of integrated photonics aims at compressing large and environmentally-sensitive optical systems to micron-sized circuits that can be mass-produced through existing semiconductor fabrication facilities. The integration of optical components on single chips is pivotal to the realization of miniature systems with high degree of complexity. Such novel photonic chips find abundant applications in optical communication, spectroscopy and signal processing. This work concentrates on harnessing nonlinear phenomena to this avail. The first part of this dissertation discusses, both from component and system level, the development of a frequency comb source with a semiconductor mode-locked laser at its heart. New nonlinear devices for supercontinuum and second-harmonic generations are developed and their performance is assessed inside the system. Theoretical analysis of a hybrid approach with synchronously-pumped Kerr cavity is also provided. The second part of the dissertation investigates stimulated Brillouin scattering (SBS) in integrated photonics. A fully-tensorial open-source numerical tool is developed to study SBS in optical waveguides composed of crystalline materials, particularly silicon. SBS is demonstrated in an all-silicon optical platform

Hartowanie serca w kardiochirurgii

Cardiac surgery is associated with ischaemic and reperfusion injury to the myocardium. It seems natural to seek a possibility of inducing the natural endoprotective mechanisms known as myocardial conditioning, including preconditioning, postconditioning, and remote conditioning. Still, in spite of almost 20 years of research in the field, we are far from routine widespread usage of these methods, with published reports describing quite various, and often contradictory results. Current review summarises the trials of using the conditioning in cardiac surgical practice including pharmacological manipulations to induce resistance to ischaemia-reperfusion. Kardiol Pol 2011; 69, supl. III: 80–84Zabieg kardiochirurgiczny wiąże się z uszkodzeniem niedokrwienno-reperfuzyjnym mięśnia sercowego. Wzbudzenie mechanizmów endoprotekcyjnych, takich jak hartowanie niedokrwieniem, hartowanie reperfuzją i hartowanie na odległość, wydaje się oczywistym kierunkiem działań zmierzających do ochrony mięśnia sercowego w trakcie operacji. Niemniej mimo niemal 20 lat, jakie minęły od pierwszej próby planowego hartowania mięśnia sercowego w kardiochirurgii, mechanizmy te nie doczekały się powszechnego zastosowania klinicznego. Wyniki uzyskiwane przez różnych autorów są dość rozbieżne, a czasem wręcz sprzeczne. W niniejszej pracy streszczono próby klinicznego wykorzystania hartowania w kardiochirurgii, w tym próby farmakologicznego wzbudzenia oporności na szkodę niedokrwienno-reperfuzyjną. Kardiol Pol 2011; 69, supl. III: 80–8

The co-application of hypoxic preconditioning and postconditioning abolishes their own protective effect on systolic function in human myocardium

Background: Ischemic preconditioning (IPC) and postconditioning (POC) are well documented to trigger cardioprotection against ischemia/reperfusion (I/R) injury, but the effect oftheir both co-application remains unclear in human heart. The present study sought to assessthe co-application of IPC and POC on fragments of human myocardium in vitro.Methods: Muscular trabeculae of the human right atrial were electrically driven in the organbath and subjected to simulated I/R injury – hypoxia/re-oxygenation injury in vitro. To achieveIPC of trabeculae the single brief hypoxia period preceded the applied lethal hypoxia, and to achieve POC triple brief hypoxia periods followed the lethal hypoxia. Additional muscular trabeculae were exposed only to the hypoxic stimulation (Control) or were subjected to the non-hypoxic stimulation (Sham). 10 μM norepinephrine (NE) application ended every experiment to assess viability of trabeculae. The contraction force of the myocardium assessed as a maximal amplitude of systolic peak (%Amax) was obtained during the whole experiment’s period.Results: Co-application of IPC and POC resulted in decrease in %Amax during the re-oxygentaionperiod and after NE application, as compared to Control (30.35 ± 2.25 vs. 41.89 ± 2.25, 56.26 ± 7.73 vs. 65.98 ± 5.39, respectively). This was in contrary to the effects observed when IPC and POC were applied separately.Conclusions: The co-application of IPC and POC abolishes the cardioprotection of either intervention alone against simulated I/R injury in fragments of the human right heart atria

Towards On-Chip Self-Referenced Frequency-Comb Sources Based on Semiconductor Mode-Locked Lasers.

Miniaturization of frequency-comb sources could open a host of potential applications in spectroscopy, biomedical monitoring, astronomy, microwave signal generation, and distribution of precise time or frequency across networks. This review article places emphasis on an architecture with a semiconductor mode-locked laser at the heart of the system and subsequent supercontinuum generation and carrier-envelope offset detection and stabilization in nonlinear integrated optics

Recommendations of the Polish Society of Gynaecologists and Obstetricians for removal of the uterus by vaginal, laparoscopic and abdominal routes

The recommendations represent the current procedure, which may be modified and changed where justified, after a thoroughanalysis of the given clinical situation, which may be the basis for their modification and updating in the future

Secure Multiparty Computations on Bitcoin

Bitcoin is a decentralized digital currency, introduced in 2008, that has recently gained noticeable popularity. Its main features are: (a) it lacks a central authority that controls the transactions, (b) the list of transactions is publicly available, and (c) its syntax allows more advanced transactions than simply transferring the money. The goal of this paper is to show how these properties of Bitcoin can be used in the area of secure multiparty computation protocols (MPCs). Firstly, we show that the Bitcoin system provides an attractive way to construct a version of timed commitments where the committer has to reveal his secret within a certain time frame, or to pay a fine. This, in turn, can be used to obtain fairness in some multiparty protocols. Secondly, we introduce a concept of multiparty protocols that work directly on Bitcoin . Recall that the standard definition of the MPCs guarantees only that the protocol emulates the trusted third party . Hence ensuring that the inputs are correct, and the outcome is respected is beyond the scope of the definition. Our observation is that the Bitcoin system can be used to go beyond the standard emulation-based definition, by constructing protocols that link their inputs and the outputs with the real Bitcoin transactions. As an instantiation of this idea we construct protocols for secure multiparty lotteries using the Bitcoin currency, without relying on a trusted authority (one of these protocols uses the Bitcoin-based timed commitments mentioned above). Our protocols guarantee fairness for the honest parties no matter how the loser behaves. For example: if one party interrupts the protocol then her money is transferred to the honest participants. Our protocols are practical (to demonstrate it we performed their transactions in the actual Bitcoin system), and can be used in real life as a replacement for the online gambling sites. We think that this paradigm can have also other applications. We discuss some of them