ABSTRACT
Deterministic generation of single- and multiphoton states is a key requirement for large-scale optical quantum information and communication applications. While heralded single-photon sources (HSPSs) using nonlinear optical processes have enabled proof-of-principle demonstrations in this area of research, they are not scalable as their probabilistic nature severely limits their generation efficiency. We overcome this limitation by demonstrating a substantial improvement in HSPS efficiency via large-scale time multiplexing. Using an ultra-low loss, adjustable optical delay to multiplex 40 conventional HSPS photon generation processes into each operation cycle, we have observed a factor of 9.7(5) enhancement in efficiency, yielding a 66.7(24)% probability of collecting a single photon with high indistinguishability (90%) into a single-mode fiber per cycle. We also experimentally investigate the trade-off between a high single-photon probability and unwanted multiphoton emission. Upgrading our time-multiplexed source with state-of-the-art HSPS and single-photon detector technologies will enable the generation of >30 coincident photons with unprecedented efficiency.
ABSTRACT
A 71-year-old male undergoing hemodialysis for chronic renal failure presented with proximal muscle weakness. He had normal levels of serum creatine phosphokinase. The results of nerve conduction velocity studies and a needle-exploration electromyogram were normal. Ultrasonography revealed adenomatous enlargement of the parathyroid glands, and he had marked elevation of the serum parathormone level. The level of serum free carnitine before hemodialysis was significantly lower than normal, while the acyl/free ratio was high. However, the muscle carnitine content was within the normal range. Interestingly, partial inactivation of carnitine palmitoyltransferase activity in the muscle was observed in association with the elevation of the serum parathormone level. Uremic myopathy in this case may be caused not only by abnormal carnitine metabolism but could also be attributable to the partial carnitine palmitoyltransferase deficiency associated with secondary hyperparathyroidism.
Subject(s)
Carnitine O-Palmitoyltransferase/deficiency , Renal Dialysis , Aged , Humans , MaleABSTRACT
Three new caged nitric oxides (NOs)-BNN3, BNN5Na, and BNN5M were tested for biological use. BNNs have a strong ultraviolet (UV) absorption band (lambda(max): 300 nm, epsilon: 13.5 mM(-1) cm (-1)) extended to 420 nm and produce NO upon irradiation with 300-360 nm light in quantum yields about 2. A photoexcited BNN molecule yields two NOs with time constants of less than 10 ns for phase 1 and less than 20 micros for phase 2 at 37 degrees C, suggesting usefulness of BNNs for measuring in vivo and in vitro fast NO reactions. Upon irradiating with UV light, caged nitric oxides-loaded rat aortic strips maintained in a state of active tonic contraction effectively relaxed ( < 3 microM BNN5M loading solution concentration). BNN3 is incorporated in the lipid membrane. BNN5Na, insoluble in organic solvents but water soluble, localizes in the water phase. BNN5M, is muscle-cell-permeable and hydrolysed to BNN5Na to remain in cytosol. BNNs were thermally stable and demonstrated no observable toxicity.
