We present superconducting nanowire single-photon detectors (SSPDs) on non-periodic dielectric multilayers, which enable us to design a variety of wavelength dependences of optical absorptance by optimizing the dielectric multilayer. By adopting a robust simulation to optimize the dielectric multilayer, we designed three types of SSPDs with target wavelengths of 500 nm, 800 nm, and telecom range respectively. We fabricated SSPDs based on the optimized designs for 500 and 800 nm, and evaluated the system detection efficiency at various wavelengths.
View Article and Find Full Text PDFWe present low temperature nano-optical characterization of a silicon-on-insulator (SOI) waveguide integrated SNSPD. The SNSPD is fabricated from an amorphous MoSi thin film chosen to give excellent substrate conformity. At 350 mK, the SNSPD exhibits a uniform photoresponse under perpendicular illumination, corresponding to a maximum system detection efficiency of approximately 5% at 1550 nm wavelength.
View Article and Find Full Text PDFWe demonstrate a new method to program the ligation of single stranded DNA-modified gold nanoparticles using copper-free click chemistry. Gold nanoparticles functionalized with a discrete number of 3'-azide or 5'-alkyne modified oligonucleotides, can be brought together via a splint strand and covalently 'clicked', in a simple one-pot reaction. This new approach to the assembly of gold nanoparticles is inherently advantageous in comparison to the traditional enzymatic ligation.
View Article and Find Full Text PDFImportance: Schizophrenia is a complex genetic disorder demonstrating considerable heritability. Genetic studies have implicated many different genes and pathways, but much of the genetic liability remains unaccounted for. Investigation of genetic forms of schizophrenia will lead to a better understanding of the underlying molecular pathways, which will then enable targeted approaches for disease prevention and treatment.
View Article and Find Full Text PDFBecause mutations are inevitable, the genome of each cell in a multicellular organism becomes unique and therefore encodes a record of its ancestry. Here we coupled arbitrary single primer PCR with next-generation DNA sequencing to catalog mutations and deconvolve the phylogeny of cultured mouse cells. This study helps pave the way toward construction of retrospective cell-fate maps based on mutations accumulating in genomes of somatic cells.
View Article and Find Full Text PDFBackground: Biopsy of the central nervous system (CNS) has been reported previously using relatively large-caliber (12-17-gauge) biopsy instruments with or without stereotactic guidance. In this series, fine-needle aspiration biopsies (FNABs) were performed using a smaller diameter needle to evaluate mass lesions of the CNS.
Methods: One hundred thirty FNABs were performed freehand under computed tomography (CT) guidance without stereotactic instrumentation guidance using a 22-gauge needle.
A 3-year-old girl with acute lymphocytic leukemia (ALL) in remission developed lower extremity paraparesis and areflexia 15 days after receiving intrathecal methotrexate, cytarabine, and hydrocortisone. Cerebrospinal fluid protein was 107 mg/dl. Compound muscle action potential amplitudes were reduced, F waves were absent, and sensory conduction studies were normal.
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