Search

Ultrathin (5–50 nm) epitaxial superconducting niobium nitride (NbN) films were grown on AlN-buffered c-plane Al2O3 by an industrial scale physical vapor deposition technique at 400°C. Both X-ray diffraction and scanning electron microscopy analysis show high crystallinity of the (111)-oriented NbN films, with a narrow full-width-at-half-maximum of the rocking curve down to 0.030°. The lattice constant decreases with decreasing NbN layer thickness, suggesting lattice strain for films with thicknesses below 20 nm. The superconducting transition temperature, the transition width, the upper critical field, the irreversibility line, and the coherence length are closely correlated to the film thickness. This work realized high quality ultrathin epitaxial NbN films by an industry-scale PVD technology at low substrate temperature, which opens up new opportunities for quantum devices.

Background Breast cancer in men accounts for fewer than 1 % of all breast cancer cases diagnosed in men and women. Genes which predispose to male breast cancer include BRCA1 and BRCA2. The role of other genes is less clear. In Poland, 20 founder mutations in BRCA1, BRCA2, CHEK2, PALB2, NBN, RECQL are responsible for the majority of hereditary breast cancer cases in women, but the utility this genes panel has not been tested in men. Methods We estimated the prevalence of 20 alleles in six genes (BRCA1, BRCA2, CHEK2, PALB2, NBN, RECQL) in 165 Polish male breast cancer patients. We compared the frequency of selected variants in male breast cancer cases and controls. Results One of the 20 mutations was seen in 22 of 165 cases (13.3%). Only one BRCA1 mutation and two BRCA2 mutations were found. We observed statistically significant associations for PALB2 and CHEK2 truncating mutations. A PALB2 mutation was detected in four cases (OR = 11.66; p CHEK2 truncating mutation was detected in five cases (OR = 2.93;p = 0.02). Conclusion In conclusion, we recommend that a molecular test for BRCA1, BRCA2, PALB2 and CHEK2 recurrent mutations should be offered to male breast cancer patients in Poland.

On 18 August 2020, TelSoc hosted the fourth NBN Futures Forum, held online, on the theme of social and economic benefits of broadband. Three speakers discussed various aspects of the topic, including the need for universal digital inclusion, the benefits of healthcare delivery via telehealth, and the actions required of government to support telehealth availability. Discussion following the speeches emphasised the need for universal access to broadband and telehealth services to improve access to health providers and, through education, reduce social inequities and overcome some social determinants of poor health outcomes.

In this paper, we study the crystalline properties and superconducting critical temperature of ultra-thin (5–9 nm) NbN films deposited on 8-inch silicon wafers by reactive sputtering. We show that the deposition of NbN on a thin (10–20 nm) AlN buffer layer, also synthesized by reactive sputtering, improves the critical temperature by several Kelvin, up to 10 K for 9 nm NbN on 20 nm AlN. We correlate this improvement to the higher-crystalline quality of NbN on AlN. While NbN deposited directly on silicon is polycrystalline with randomly oriented grains, NbN on AlN(0001) is textured along (111), due to the close lattice match. The superconducting properties of the NbN/AlN stack are validated by the demonstration of fibre-coupled normal-incidence superconducting nanowire single photon detectors. The whole fabrication process is CMOS compatible, with a thermal budget compatible with the integration of other passive and active components on silicon. These results pave the way for the integration of a large number of surface or waveguide-integrated detectors on large-scale silicon wafers. Furthermore, as AlN is transparent over a broad wavelength range from the visible to the near-infrared, the optimized superconducting NbN/AlN stack can be used for a wide variety of applications, from imaging to quantum communications and quantum computing.

3D integration has well-developed for traditional CMOS technology operating at room temperature, but few studies have been performed for cryogenic applications such as quantum computers. In this paper, a wafer-to-wafer bonding of superconductive joints based on niobium nitride (NbN) is performed to demonstrate the possibility of 3D integration of superconducting chips. The NbN thin films are deposited by magnetron sputtering. Its high critical temperature (15.2 K) is achieved by optimizing the sputtering recipe in terms of N2 flow rate and discharge voltage. Wafer-level bumping is bonded by the thermo-compression method. The sheet resistance of the thin film and the contact resistance of the joints are measured by the Greek-cross (4-point Kelvin method) and daisy chain structures at cryogenic temperature, respectively. Direct-bonding wafers with NbN superconductive joints avoid using adhesive layers and the bonding interface could still present superconducting electrical connections in a cryogenic environment above 4 K, which will allow us to use a smaller and high-cooling power cryostat. The contribution of this work could lead to the fabrication of multi-layered superconducting chip that operates beneficially in cryogenic temperature, which is essential in building scalable quantum processors.

Background Family history is one of the risk factors for pancreatic cancer. It is suggested that patients with pancreatic cancer who have a familial history harbor germline pathogenic variants of BRCA1 and/or BRCA2 (BRCA1/2), PALB2, or ATM. Recently, some germline variants of familial pancreatic cancers (FPCs), including PALB2, have been detected. Several countries, including Japan, perform screening workups and genetic analysis for pancreatic cancers. We have been carrying out active surveillance for FPC through epidemiological surveys, imaging analyses, and genetic analysis. Case presentation Here, we present the case of a female patient harboring pathogenic variants of PALB2 and NBN, with a family history of multiple pancreatic cancer in her younger brother, her aunt, and her father. Moreover, her father harbored a PALB2 pathogenic variant and her daughter harbored the same NBN pathogenic variant. Given the PALB2 and NBN variants, we designed surveillance strategies for the pancreas, breast, and ovary. Conclusions Further studies are required to develop strategies for managing FPCs to facilitate prompt diagnosis before their progression.

Central nervous system (CNS) embryonal tumors (WHO grade IV) are a heterogeneous group of rare, poorly differentiated neuroepithelial malignant neoplasms that commonly occur in children, and they have a poor prognosis. The 2016 WHO (World Health Organization) classification of CNS tumors created a major shift in paradigm of the classification of embryonal tumors. However, some cases were still difficult to classify. Further integrative genomic analysis is needed to improve the precise classification, diagnosis and treatment of CNS embryonal tumors. Herein, we firstly report a case of CNS embryonal tumor harboring the pathogenic CIC–LEUTX gene fusion. A 2-year-old male infant presented with a solid cystic mass in the left temporal lobe-basal ganglia and left parietal lobe (maximum diameter, 75 mm) and underwent gross tumor resection. The tumor was classified as a poorly differentiated embryonal neoplasm of neuroectodermal origin that lacked specific features and rosettes. By immunohistochemistry, the tumor cells were strongly positive for synaptophysin, and the Ki67 proliferation index was high (>50%). FISH (Fluorescence in situ hybridization) results indicated no change in the copy number at the 19q13.42 C19MC locus. Next generation sequencing showed a CIC–LEUTX gene fusion, a somatic TSC2 c.G2714A mutation, and a heterozygous germline NBN c.C127T mutation. One month after surgery, there was recurrence of the intracranial tumor (maximum diameter, 55 mm) as well as spinal cord implantation metastasis. The patient received chemotherapy (CTX+CBP+VCR/DDP+VP-16), radiotherapy, and a drug targeting the TSC2 gene (everolimus). At the time of this writing, the patient is alive without evidence of disease for 11 months. This is the first report of the CIC–LEUTX gene fusion in a case of CNS embryonal tumor.

// Naoki Ikari 1, 2, * , Shota Aoyama 1, * , Akiyoshi Seshimo 1 , Yuji Suehiro 3 , Tomoko Motohashi 3 , Shohei Mitani 3 , Sawako Yoshina 3 , Etsuko Tanji 2 , Akiko Serizawa 1 , Takuji Yamada 1 , Kiyoaki Taniguchi 1 , Masakazu Yamamoto 1 and Toru Furukawa 2, 4, 5 1 Department of Surgery, Institute of Gastroenterology, Tokyo Women’s Medical University, Tokyo, Japan 2 Institute for Integrated Medical Sciences, Tokyo Women’s Medical University, Tokyo, Japan 3 Department of Physiology, Tokyo Women’s Medical University School of Medicine, Tokyo, Japan 4 Department of Surgical Pathology, Tokyo Women’s Medical University Hospital, Tokyo, Japan 5 Department of Histopathology, Tohoku University Graduate School of Medicine, Sendai, Japan * These authors have contributed equally to this work Correspondence to: Toru Furukawa, email: toru.furukawa@med.tohoku.ac.jp Keywords: early gastric cancer; lymph node metastasis; lymphangiogenesis; NBN ; PAX8 Received: May 18, 2017 Accepted: January 13, 2018 Published: January 22, 2018 ABSTRACT Background and aim: Intramucosal gastric adenocarcinoma of the well-moderately differentiated type only exhibits lymph node metastasis in extremely rare cases. We encountered such case and investigated both the lymphangiogenic properties and somatic mutations in the cancer to understand the prometastatic features of early-stage gastric cancer. Methods: We quantitatively measured the density of lymphatic vessels and identified mutations in 412 cancer-associated genes through next-generation target resequencing of DNA extracted from tumor cells in a formalin-fixed and paraffin-embedded tissue. Functional consequence of the identified mutation was examined in vitro by means of gene transfection, immunoblot, and the quantitative real-time polymerase chain reaction assay. Results: The intramucosal carcinoma was accompanied by abundant lymphatic vessels. The metastatic tumor harbored somatic mutations in NBN , p.P6S, and PAX8 , p.R49H. The PAX8 R49H showed significantly higher transactivation activity toward E2F1 than the wild-type PAX8 (P< 0.001). Conclusions: Our data suggest that increased lymphangiogenesis and somatic mutations of NBN and/or PAX8 could facilitate lymph node metastasis from an intramucosal gastric carcinoma. These findings may potentially inform evaluations of the risk of developing lymph node metastasis in patients with intramucosal gastric cancer.

* “Chó bò” is the approximate Vietnamese homonym for “trouble.” Bluntly translated, “chó~bò” is a “dog~cow” or “dog~crawl.” This absurdist linguistic joke for many Vietnamese people learning English represents a capacity to make trouble. This PhD thesis comprises original research and artistic work made with my family. As people from the Vietnamese diaspora, our experiences are formed by dispersals and estrangements as settler-colonists in Australia. Our daily encounters in the realms that this thesis is focused – contemporary art, academia, and family enterprise, are folded into distinct systems of colonial power and violence. I often make work with my family in video-performance and the documentary medium. Our inter-generational, political, and language differences add to the conceptual complexity of what it means to collaborate, make art, produce archives, and confront our position as recent settler-colonisers in Australia. This thesis aims to address how our artistic collaborations utilise linguistic and archival approaches to articulate the systemic racism we encounter as people from a refugee background, but who are also embedded in the colonial infrastructures of our new home. Aligning with thinkers including Gloria Anzaldúa and her critique of coloniality, to Gayatri Chakravorty Spivak and Hito Steyerl on minoritarian forms of translation, and Sara Ahmed on racism in the university - this thesis describes how collaborations with my family can trouble the contradictions of colonial power enacted on our human relationships. Reconnecting with individual members of my family through art, I have gained a better understanding of my language and culture, as well as finding important artistic and political connection to my peers. Collaborating with my family has forced me to rub against the researcher-participant/research subject binary, the archival visibility of being invisible, the rhetoric of institutional inclusion, and the weight of being displaced and displacing colonisers on this continent. The work we have produced together methodologically uncovers and critiques the opaque confrontations of institutional power, racism, and colonial violence embedded in the everyday. As a family, we continue to make uncomfortable pronunciations like “chó bò,” producing the epistemic trouble needed to face the colonial realities of our resettlement. ARTWORK WEBSITE: https://chobotrouble.com/

Introduction : The NBN gene product is part of the MRE11/RAD50/ NBN complex, which plays an essential role in genomic stability. In the study we try to answer the question what is the effect of irradiation on DNA synthesis, NBN gene expression and chromosomal stability in cells with homozygous c.657-661del, and heterozygous c.657-661del, p.I171V and p.R215W NBN gene mutations. Material and methods : Immortalized B-lymphocytes with NBN gene mutations were X-ray irradiated at doses of 1, 2, 5 and 8 Gy/min. Radioresistant DNA synthesis rate and the percentage of cells in phase S was analyzed by 3H thymidine and BrdU incorporation assays. NBN gene expression was quantified by real-time PCR with TaqMan fluorescent probe. Results : Increasing the irradiation dose resulted in gradual decrease of 3H thymidine incorporation in all cells, but significantly only in homo- and heterozygous c.657-661del cells (p-values < 0.0001). After irradiation the relative expression of NBN was significantly higher in homozygous c.657-661del and heterozygous p.R215W cells as compared to heterozygous c.657-661del, p.I171V and control cells (p < 0.01). All cells with NBN gene mutations showed significantly higher total number of chromosomal aberrations per metaphase as compared to control cells, with the highest number of aberrations in homozygous c.657-661del cells (p < 0.001). Conclusions : The results obtained indicate that homozygous c.657-661del mutation affects cell sensitivity to irradiation. Moreover, homozygous variant is associated with disturbance in the activation of cell cycle checkpoints and with defects in DNA repair. In turn, heterozygous c.657-661del, p.R215W and p.I171V mutations do not substantially alter the radiosensitivity.

// Philipp Seidel 1,2 , Martina Remus 3 , Michael Delacher 4 , Paulius Grigaravicius 3 , David E. Reuss 5 , Lucien Frappart 6 , Andreas von Deimling 3,5 , Markus Feuerer 4 , Amir Abdollahi 1,2 and Pierre-Olivier Frappart 3 1 Molecular and Translational Radiation Oncology, National Center for Tumor Diseases (NCT), Heidelberg University Medical School (HUMS), Heidelberg, Germany 2 German Cancer Consortium (DKTK) and Heidelberg Institute of Radiation Oncology (HIRO), German Cancer Research Center (DKFZ), Heidelberg, Germany 3 Clinical Cooperation Unit Neuropathology, German Cancer Research Center (DKFZ), Heidelberg, Germany 4 Helmholtz Young Investigator Group Immune Tolerance, Tumor Immunology Program, German Cancer Research Center, Heidelberg, Germany 5 Department of Neuropathology, Institute of Pathology, Ruprecht-Karls-Universitat Heidelberg, Heidelberg, Germany 6 Leibniz Institute for Age Research - Fritz Lipmann Institute (FLI), Jena, Germany Correspondence to: Pierre-Olivier Frappart, email: // Keywords : inflammation, Nbn, psoriasiform dermatitis, skin, Gerotarget Received : February 17, 2016 Accepted : March 22, 2016 Published : March 30, 2016 Abstract Nijmegen Breakage Syndrome is a disease caused by NBN mutations. Here, we report a novel function of Nbn in skin homeostasis. We found that Nbn deficiency in hair follicle (HF) progenitors promoted increased DNA damage signaling, stimulating p16 Ink4a up-regulation, Trp53 stabilization and cytokines secretion leading to HF-growth arrest and hair loss. At later stages, the basal keratinocytes layer exhibited also enhanced DNA damage response but in contrast to the one in HF progenitor was not associated with pro-inflammatory cytokines expression, but rather increased proliferation, lack of differentiation and immune response resembling psoriasiform dermatitis. Simultaneous Nbn and Trp53 inactivation significantly exacerbated this phenotype, due to the lack of inhibition of pro-inflammatory cytokines secretion by Trp53. Altogether, we demonstrated novel functions of Nbn in HF maintenance and prevention of skin inflammation and we provide a mechanistic explanation that links cell intrinsic DNA maintenance with large scale morphological tissue alterations.

There are twenty recurrent mutations in six breast-cancer-predisposing genes in Poland (BRCA1, BRCA2, CHEK2, PALB2, NBN, and RECQL). The frequencies of the twenty alleles have not been measured in a large series of early-onset breast cancer patients from Poland unselected for family history. We genotyped 2464 women with breast cancer diagnosed below age 41 years for twenty recurrent germline mutations in six genes, including BRCA1, BRCA2 CHEK2, PALB2, NBN, and RECQL. A mutation in one of the six genes was identified in 419 of the 2464 early-onset breast cancer cases (17%), including 22.4% of those cases diagnosed below age 31. The mutation frequency was 18.8% for familial breast cancer cases and 6% for non-familial cases. Among women with breast cancer below age 31, the mutation frequency was 23.6% for familial cases and 17.4% in non-familial cases. The majority of mutations (76.2%) were seen in BRCA1 and BRCA2. In Poland, a panel of twenty recurrent mutations in six genes can identify a genetic basis for a high percentage of early-onset cases and testing is recommended for all women with breast cancer at age 40 or below.

Certain cancers pave way for other primary cancers to emerge with genetic disturbances serving as a common denominator as demonstrated by our male patient who developed prostate cancer within three months of being diagnosed with breast cancer despite being negative for the major genetic mutations, BRCA1 and BRCA2 and having a negative family history for cancers. Here we examine overlapping major and minor contributing risk factors and the limitations of the most current screening guidelines.

Purpose The purpose of this study was to establish the contribution of four founder alleles of NBN to prostate cancer risk and cancer survival. Materials and Methods Five thousand one hundred eighty-nine men with prostate cancer and 6,152 controls were genotyped for four recurrent variants of NBN (657del5, R215W, I171V, and E185Q). Results The NBN 657del5 mutation was detected in 74 of 5,189 unselected cases and in 35 of 6,152 controls (odds ratio [OR], 2.5; p < 0.001). In carriers of 657del5 deletion, the cancer risk was restricted to men with the GG genotype of the E185Q variant of the same gene. Among men with the GG genotype, the OR associated with 657del5 was 4.4 (95% confidence interval [CI], 2.4 to 8.0). Among men with other E185Q genotypes, the OR associated with 657del5 was 1.4 (95% CI, 0.8 to 2.4) and the interaction was significant (homogeneity p=0.006). After a median follow-up of 109 months, mortality was worse for 657del5 mutation carriers than for non-carriers (hazard ratio [HR], 1.6; p=0.001). The adverse effect of 657del5 on survival was only seen on the background of the GG genotype of E185Q (HR, 1.9; p=0.0004). Conclusion The NBN 657del5 mutation predisposes to poor prognosis prostate cancer. The pathogenicity of this mutation, with regards to both prostate cancer risk and survival, is modified by a missense variant of the same gene (E185Q).

Clinical criteria for genetic testing of genes other thanBRCA1/2in epithelial ovarian cancer (EOC) still do not exist. We assessed the frequency and predictors of deleterious mutations in 19 cancer predisposition genes in high-grade serous ovarian cancer (HGSOC) in Serbia. Next-generation sequencing was used to identify germline mutations in the whole coding regions of a gene panel. Patients’ characteristics and sequencing data were summarized with descriptive statistics and compared using chi-square test. Among 131 HGSOC patients, 23 hadBRCA1(17.6%) while 5 hadBRCA2(3.8%) mutation. In addition, 9 (6.9%) pathogenic mutations were detected in other genes includingBRIP1(n = 2;1.5%),CHEK2(n = 2;1.5%),NBN(n = 3;2.3%) andRAD51C(n = 2;1.5%). Factors that predicted forBRCA1/2mutations were: breast and ovarian cancers in the same patient (p = 0.031), young age of EOC (p = 0.029), menstrual status (p = 0.004) and family history of cancer (p BRCA1/2mutation carriers but will not help identify mutations in other cancer susceptibility genes. Until better predictors emerge we should be performing wider genetic testing of EOC in order to identify all mutation carriers.

Tarkista embargo, kun artikkeli julkaistu. Antireflection surfaces are often utilized in optical components to reduce undesired reflection and increase absorption. We report on black silicon (b-Si) with dramatically enhanced absorption over a broad wavelength range (250– 2500 nm) achieved by applying a 10–15 nm conformal coating of NbN with atomic layer deposition (ALD). The improvement is especially pronounced in the near infrared (NIR) range of 1100– 2500 nm where absorption is increased by >90%. A significant increase of absorption is also observed over the ultraviolet (UV) range of 200–400 nm. Preceding NbN deposition with a nanostructured ALD Al2O3 (n-Al2O3) coating to enhance the NbN texture was also examined. Such texturing further improves absorption in the NIR, especially at longer wavelengths, strong absorption up to 4–5 μm wavelengths has been attested. For comparison, double side polished silicon and sapphire coated with 10 nm-thick NbN exhibited absorption of only ~55% in the NIR range of 1100–2500 nm. The results suggest a positive correlation between the surface area of NbN coating and optical absorption. Based on the wide-band absorption, the presented NbN-coated b-Si may be an attractive candidate for use in e.g. spectroscopic systems, infrared microbolometers.

Clinical importance of the most common CHEK2 (IVS2+1 G>A, 1100delС, I157T and del5395) and NBN (R215W and 657del5) gene mutations for breast cancer development in Macedonian breast cancer patients is unknown. We performed a case-control study including 300 Macedonian breast cancer patients and 283 Macedonian healthy controls. Genotyping was done using a fast and highly accurate single-nucleotide primer extension method for the detection of five mutations in a single reaction. The detection of the del5395 was performed using an allele-specific duplex polymerase chain reaction (PCR) assay. We have found that mutations were more frequent in breast cancer patients (n = 13, 4.3%) than in controls (n = 5, 1.8%), although without statistical significance. Twelve patients were heterozygous for one of the analyzed mutations, while one patient had two mutations (NBN R215W and CHEK2 I157T). The most frequent variant was I157T, found in 10 patients and four controls (p = 0.176) and was found to be associated with familial breast cancer (p = 0.041). CHEK2 1100delC and NBN 657del5 were each found in one patient and not in the control group. CHEK2 IVS2+1G>A and del5395 were not found in our cohort. Frequencies of the studied mutations are low and they are not likely to represent alleles of clinical importance in the Macedonian population.

Silicon carbide (SiC) is among the most promising optical materials for the realization of classical and quantum photonics, due to the simultaneous presence of quantum emitters and a non-centrosymmetric crystal structure. In recent years, progress have been made in the development of SiC integrated optical components making this a mature platform for the implementation of quantum experiments on chip. Toward this scope, the fabrication of a single photon detector that can be implemented on top of a photonic circuit is essential to achieve a monolithic integration of all the fundamental building blocks required for photonic quantum technologies. Here we demonstrate for the first time single photon detection with superconducting nanowires on top of a bare 3C SiC layer using a novel approach for the fiber-to-detector coupling that allows the optical characterization of multiple detectors without the use of neither cryogenic positioners nor the micromachining of the substrate.

Background: To evaluate whether genotyping for 18 prostate cancer founder variants is helpful in identifying high-risk individuals and for determining optimal screening regimens. Methods: A serum PSA level was measured and a digital rectal examination (DRE) was performed on 2907 unaffected men aged 40–90. Three hundred and twenty-three men with an elevated PSA (⩾4 ng ml−1) or an abnormal DRE underwent a prostate biopsy. All men were genotyped for three founder alleles in BRCA1 (5382insC, 4153delA and C61G), for four alleles in CHEK2 (1100delC, IVS2+1G>A, del5395 and I157T), for one allele in NBS1 (657del5), for one allele in HOXB13 (G84E), and for nine low-risk single-nucleotide polymorphisms (SNPs). Results: On the basis of an elevated PSA or an abnormal DRE, prostate cancer was diagnosed in 135 of 2907 men (4.6%). In men with a CHEK2 missense mutation I157T, the cancer detection rate among men with an elevated PSA or an abnormal DRE was much higher (10.2%, P=0.0008). The cancer detection rate rose with the number of SNP risk genotypes observed from 1.2% for men with no variant to 8.6% for men who carried six or more variants (P=0.04). No single variant was helpful on its own in predicting the presence of prostate cancer, however, the combination of all rare mutations and SNPs improved predictive power (area under the curve=0.59; P=0.03). Conclusion: These results suggest that testing for germline CHEK2 mutations improves the ability to predict the presence of prostate cancer in screened men, however, the clinical utility of incorporating DNA variants in the screening process is marginal.

In this work we present the fabrication and the electro-optical characterization of a 24-pixel photon-number-resolving-detector, based on superconducting nanowires in a series configuration. In this configuration, the electrical responses of each firing pixel sum up into a single readout pulse whose height is proportional to the detected photon number. This device can resolve up to twenty-five distinct output levels corresponding to the detection of n = 0 - 24 photons. Due to its large dynamic range, high sensitivity, high speed and wide wavelength range, this device has potential for linear detection in the few tens of photons range.

We examined a microstrip line structure to reduce the current concentration at the outer edge of a microstrip line. We developed three kinds of microstrip line; sliced-microstrip line, layered-film microstrip line, and conventional microstrip line. The first microstrip line is a line divided into the narrow line, and the second one is a line made by a layered thin film. Electromagnetic simulations indicated that the current concentration of the outer edge of the sliced microstrip line and layered film microstrip line was lower than that of a conventional microstrip line. We measured the power handling capability of the filters made by sliced-microstrip lines, layered-film microstrip lines, and conventional microstrip lines. The value of the first and the second filters was better than that of a conventional one. The difference in the characteristics is based on the difference in the current concentration at the outer edge of the microstrip lines.

We measured the temperature- and current-dependence of dark count rates of a superconducting single-photon detector. The detector's key element is a 84 nm wide meander strip line fabricated from an 5 nm thick NbN film. Due to its reduced dimensions various types of fluctuations cancause temporal and localizied transitions into a resistive state leading to dark count events. Adopting a recent refinement of the hot-spot model we achieve a satisfying description of the experimental dark count rates taking into account fluctuations of the Cooper-pair density and current-assisted unbinding of vortex-antivortex pairs.

The hotspot model has been used to simulate the intermediate frequency bandwidth of a lattice cooled NbN hot-electron bolometer mixer. The results of simulation suggest that with the increase of the bias current, the bandwidth decreases, passes the minimum, and recovers again. The appearance of the bandwidth minimum correlates with experimentally observed noise maximum at the mixer output that drastically reduces the sensitivity of a relevant receiver. At large bias currents the bandwidth exceeds the reciprocal electron cooling time. Since the noise temperature also increases with the bias current, a compromise between the desirable bandwidth and acceptable noise temperature can be reached by varying the bias current.

Thorough spectral study of the intrinsic single-photon detection efficiency in superconducting TaN and NbN nanowires with different widths shows that the experimental cut-off in the efficiency at near-infrared wavelengths is most likely caused by the local deficiency of Cooper pairs available for current transport. For both materials the reciprocal cut-off wavelength scales with the wire width whereas the scaling factor quantitatively agrees with the hot-spot detection models. Comparison of the experimental data with vortex-assisted detection scenarios shows that these models predict a stronger dependence of the cut-off wavelength on the wire width., 16 pages, 6 figures

We present our progress in the development of an integrated technology suitable for the photonic quantum information processing, showing the first autocorrelator based on two separated detectors integrated on top of the same ridge waveguide. An efficiency of ~1% at 1300 nm for both detectors and independent of the polarization of the incoming photons, is reported. This ultracompact device enables the on-chip measurement of the second-order correlation function g (2) (τ) . We will further discuss ongoing work on the integration of detectors with single-photon sources.

We report on electrical properties and microstructure of epitaxial thin NbN films grown on 3C-SiC/Si substrates by means of reactive magnetron sputtering. A complete epitaxial growth at the NbN/3C-SiC interface has been confirmed by means of high resolution transmission electron microscopy (HRTEM) along with x-ray diffractometry (XRD). Resistivity measurements of the films have shown that the superconducting transition onset temperature (TC) for the best specimen is 11.8 K. Using these epitaxial NbN films, we have fabricated submicron-size hot-electron bolometer (HEB) devices on 3C-SiC/Si substrate and performed their complete DC characterization. The observed critical temperature TC = 11.3 K and critical current density of about 2.5 MA cm − 2 at 4.2 K of the submicron-size bridges were uniform across the sample. This suggests that the deposited NbN films possess the necessary homogeneity to sustain reliable hot-electron bolometer device fabrication for THz mixer applications.

We have studied the sensitivity of a superconducting NbN hot electron bolometer mixer integrated with a spiral antenna at 4.3 THz. Using hot/cold blackbody loads and a beam splitter all in vacuum, we measured a double sideband receiver noise temperature of 1300 K at the optimum local oscillator (LO) power of 330 nW, which is about 12 times the quantum noise (hv/2k(B)). Our result indicates that there is no sign of degradation of the mixing process at the super-THz frequencies. Also, a measurement method is introduced where the hot/cold response of the receiver is recorded at constant voltage bias of the mixer, while varying the LO power. We argue that this method provides an accurate measurement of the receiver noise temperature, which is not influenced by the LO power fluctuations and the direct detection effect. Moreover, our sensitivity data suggests that one can achieve a receiver noise temperature of 1420 K at the frequency of [OI] line (4.7 THz), which is scaled from the sensitivity at 4.3 THz with frequency.

NbN superconductor and wide band gap AIN thin films were deposited using sputtering at room temperature. Study of the nitride interfaces are forerunner to the growth Josephson junctions that are considered able to work in the terahertz frequency. We find that to be compatible with lithography technology and to have a high critical transition temperature, the substrate should not be overheated, and this means working in low power regime to limit the induced heating of the plasma. X-ray photoelectron spectroscopy and X-ray diffraction analysis were performed on samples deposited on crystalline, amorphous, flexible, and nanostructured substrates. The experimental results suggest us how to improve the deposition process in order to obtain the best nitride films as well as NbN/A1N/NbN trilayers for Josephson junction applications. (C) 2006 Elsevier B.V. All rights reserved.

Heterodyne receivers for applications in astronomy need quantum limited sensitivity. We have investigated phonon- cooled NbN hot electron bolometric mixers in the frequency range from 0.7 THz to 5.2 THz. The devices were 3.5 nm thin films with an in-plane dimension of 1.7 X 0.2 micrometers 2 integrated in a complementary logarithmic spiral antenna. The best measured DSB receiver noise temperatures are 1300 K (0.7 THz), 2000 K (1.4 THz), 2100 K (1.6 THz), 2600 K (2.5 THz), 4000 K (3.1 THz), 5600 K (4.3 THz), and 8800 K (5.2 THz). The sensitivity fluctuation, the long term stability, and the antenna pattern were measured. The results demonstrate that this mixer is very well suited for GREAT, the German heterodyne receiver for SOFIA.

This paper describes how the Italian national bibliography number (NBN) service has become a trusted infrastructure when it has been combined with digital stacks, the national digital preservation infrastructure. A suitable descriptive model, the bricks of trust, to assess the trustworthiness of the PI systems, has been provided. The Italian NBN has been positively assessed according to this model.

We demonstrate efficient nanowire superconducting single photon detectors (SSPDs) based on NbN thin films grown on GaAs. NbN films ranging from 3 to 5 nm in thickness have been deposited by dc magnetron sputtering on GaAs substrates at 350 degrees C. These films show superconducting properties comparable to similar films grown on sapphire and MgO. In order to demonstrate the potential for monolithic integration, SSPDs were fabricated and measured on GaAs/AlAs Bragg mirrors, showing a clear cavity enhancement, with a peak quantum efficiency of 18.3% at lambda=1300 nm and T=4.2 K. (C) 2010 American Institute of Physics. [doi:10.1063/1.3496457]

// Alejandro Berlin 1,2,* , Emilie Lalonde 1,3,* , Jenna Sykes 1 , Gaetano Zafarana 1 , Kenneth C. Chu 1,3 , Varune R. Ramnarine 4 , Adrian Ishkanian 1,2 , Dorota H.S. Sendorek 1 , Ivan Pasic 1 , Wan L. Lam 4,5 , Igor Jurisica 6 , Theo van der Kwast 1 , Michael Milosevic 1,2 , Paul C. Boutros 1,3 and Robert G. Bristow 1,2 1 Departments of Radiation Oncology, Medical Biophysics, Medical Oncology, Laboratory Medicine and Pathology, Pharmacology & Toxicology and Biostatistics, Computer Science, University of Toronto, Toronto, ON, Canada 2 Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada 3 Informatics and Bio-Computing, Ontario Institute for Cancer Research, Toronto, ON, Canada 4 Vancouver Prostate Centre & Department of Urologic Sciences, University of British Columbia, Vancouver, BC, Canada 5 Department of Integrative Oncology, British Columbia Cancer Research Centre, Vancouver, BC, Canada 6 The Techna Institute, University Health Network, Toronto, ON, Canada * These authors contributed equally to this work Correspondence: Robert G. Bristow, email: // Keywords : prostate cancer, NBN, MRN complex, radiotherapy, biomarker, aCGH Received : July 10, 2014 Accepted : August 26, 2014 Published : August 27, 2014 Abstract Despite the use of clinical prognostic factors (PSA, T-category and Gleason score), 20-60% of localized prostate cancers (PCa) fail primary local treatment. Herein, we determined the prognostic importance of main sensors of the DNA damage response (DDR): MRE11A, RAD50, NBN, ATM, ATR and PRKDC. We studied copy number alterations in DDR genes in localized PCa treated with image-guided radiotherapy (IGRT; n=139) versus radical prostatectomy (RadP; n=154). In both cohorts, NBN gains were the most frequent genomic alteration (14.4 and 11% of cases, respectively), and were associated with overall tumour genomic instability (p

We present a new photon number resolving detector (PNR), the Parallel Nanowire Detector (PND), which uses spatial multiplexing on a subwavelength scale to provide a single electrical output proportional to the photon number. The basic structure of the PND is the parallel connection of several NbN superconducting nanowires (100 nm wide, few nm thick), folded in a meander pattern. Electrical and optical equivalents of the device were developed in order to gain insight on its working principle. PNDs were fabricated on 3-4 nm thick NbN films grown on sapphire (substrate temperature TS = 900C) or MgO (TS = 400C) substrates by reactive magnetron sputtering in an Ar/N2 gas mixture. The device performance was characterized in terms of speed and sensitivity. The photoresponse shows a full width at half maximum (FWHM) as low as 660 ps. PNDs showed counting performance at 80 MHz repetition rate. Building the histograms of the photoresponse peak, no multiplication noise buildup is observable and a one-photon quantum efficiency can be estimated to be 3% (at 700 nm wavelength and 4.2 K temperature). The PND significantly outperforms existing PNR detectors in terms of simplicity, sensitivity, speed, and multiplication noise.