301 research outputs found
Telerobotic Space Station Applications
This paper presents telerobotic space station applications, important issues in telerobotics and work at the University of Alabama in Huntsville in the area of telerobotics
Gold(I)-Catalysed Direct Thioetherifications Using Allylic Alcohols: an Experimental and Computational Study
A gold(I)-catalysed direct thioetherification reaction between allylic alcohols and thiols is presented. The reaction is generally highly regioselective (S(N)2′). This dehydrative allylation procedure is very mild and atom economical, producing only water as the by-product and avoiding any unnecessary waste/steps associated with installing a leaving or activating group on the substrate. Computational studies are presented to gain insight into the mechanism of the reaction. Calculations indicate that the regioselectivity is under equilibrium control and is ultimately dictated by the thermodynamic stability of the products
Irradiation study of a fully monolithic HV-CMOS pixel sensor design in AMS 180 nm
High-Voltage Monolithic Active Pixel Sensors (HV-MAPS) based on the 180 nm
HV-CMOS process have been proposed to realize thin, fast and highly integrated
pixel sensors. The MuPix7 prototype, fabricated in the commercial AMS H18
process, features a fully integrated on-chip readout, i.e. hit-digitization,
zero suppression and data serialization. It is the first fully monolithic
HV-CMOS pixel sensor that has been tested for the use in high irradiation
environments like HL-LHC. We present results from laboratory and test beam
measurements of MuPix7 prototypes irradiated with neutrons (up to
) and protons (up to ) and compare the performance with non-irradiated
sensors. Efficiencies well above 90 % at noise rates below 200 Hz per pixel are
measured. A time resolution better than 22 ns is measured for all tested
settings and sensors, even at the highest irradiation fluences. The data
transmission at 1.25 Gbit/s and the on-chip PLL remain fully functional
Thyroid cancer in a patient with a germline MSH2 mutation. Case report and review of the Lynch syndrome expanding tumour spectrum
Lynch syndrome (HNPCC) is a dominantly inherited disorder characterized by germline defects in DNA mismatch repair (MMR) genes and the development of a variety of cancers, predominantly colorectal and endometrial. We present a 44-year-old woman who was shown to carry the truncating MSH2 gene mutation that had previously been identified in her family. Recently, she had been diagnosed with an undifferentiated carcinoma of the thyroid and an adenoma of her coecum. Although the thyroid carcinoma was not MSI-high (1 out of 5 microsatellites instable), it did show complete loss of immunohistochemical expression for the MSH2 protein, suggesting that this tumour was not coincidental. Although the risks for some tumour types, including breast cancer, soft tissue sarcoma and prostate cancer, are not significantly increased in Lynch syndrome, MMR deficiency in the presence of a corresponding germline defect has been demonstrated in incidental cases of a growing range of tumour types, which is reviewed in this paper. Interestingly, the MSH2-associated tumour spectrum appears to be wider than that of MLH1 and generally the risk for most extra-colonic cancers appears to be higher for MSH2 than for MLH1 mutation carriers. Together with a previously reported case, our findings show that anaplastic thyroid carcinoma can develop in the setting of Lynch syndrome. Uncommon Lynch syndrome-associated tumour types might be useful in the genetic analysis of a Lynch syndrome suspected family if samples from typical Lynch syndrome tumours are unavailable
Screening for germline DND1 mutations in testicular cancer patients
Although several observations suggest that a strong genetic predisposition to developing testicular germ cell tumors (TGCT) exists, no associated, highly penetrant germline mutations have been identified so far. In the 129/Sv mouse strain, a germline mutation in the DND1 gene has been shown to strongly increase the TGCT risk. We screened 272 men with TGCT (89% sporadic cases, 11% familial) for germline mutations in the human homologue of DND1. A single nucleotide substitution c.657C > G (p.Asp219Glu) was observed in a non-familial case of testicular embryonal carcinoma. The variant was also present in the patient’s asymptomatic father and two brothers, but not observed in 210 control chromosomes. The wild type DND1 allele was not lost in the patient’s tumor. In silico analysis of the variant predicts it to be non-pathogenic. We conclude that germline DND1 mutations are unlikely to contribute significantly to human testicular germ cell tumor susceptibility. The role of human DND1 in normal physiology and disease, however, is still virtually unknown and it therefore warrants further research
Upgrading the beam telescopes at the DESY II Test Beam Facility
The DESY II Test Beam Facility is a key infrastructure for modern high energy physics detector development, providing particles with a small momentum spread in a range from 1 to 6 GeV to user groups e.g. from the LHC experiments and Belle II as well as generic detector R&D. Beam telescopes are provided in all three test beam areas as precise tracking reference without time stamping, with triggered readout and a readout time of >115 s . If the highest available rates are used, multiple particles are traversing the telescopes within one readout frame, thus creating ambiguities that cannot be resolved without additional timing layers. Several upgrades are currently investigated and tested: Firstly, a fast monolithic pixel sensor, the TelePix, to provide precise track timing and triggering on a region of interest is proposed to overcome this limitation. The TelePix is a 180 nm HV-CMOS sensor that has been developed jointly by DESY, KIT and the University of Heidelberg and designed at KIT. In this publication, the performance evaluation is presented: The difference between two amplifier designs is evaluated. A high hit detection efficiency of above 99.9 % combined with a time resolution of below 4 ns at negligible pixel noise rates is determined. Finally, the digital hit output to provide region of interest triggering is evaluated and shows a short absolute delay with respect to a traditional trigger scintillator as well as an excellent time resolution. Secondly, a fast LGAD plane has been proposed to provide a time resolution of a few 10 ps, which is foreseen to drastically improve the timing performance of the telescope. Time resolutions of below 70 ps have been determined in collaboration with the University of California, Santa Barbara
Practical guidelines for interpreting copy number gains detected by high-resolution array in routine diagnostics
The correct interpretation of copy number gains in patients with developmental delay and multiple congenital anomalies is hampered by the large number of copy number variations (CNVs) encountered in healthy individuals. The variable phenotype associated with copy number gains makes interpretation even more difficult. Literature shows that inheritence, size and presence in healthy individuals are commonly used to decide whether a certain copy number gain is pathogenic, but no general consensus has been established. We aimed to develop guidelines for interpreting gains detected by array analysis using array CGH data of 300 patients analysed with the 105K Agilent oligo array in a diagnostic setting. We evaluated the guidelines in a second, independent, cohort of 300 patients. In the first 300 patients 797 gains of four or more adjacent oligonucleotides were observed. Of these, 45.4% were de novo and 54.6% were familial. In total, 94.8% of all de novo gains and 87.1% of all familial gains were concluded to be benign CNVs. Clinically relevant gains ranged from 288 to 7912 kb in size, and were significantly larger than benign gains and gains of unknown clinical relevance (P<0.001). Our study showed that a threshold of 200 kb is acceptable in a clinical setting, whereas heritability does not exclude a pathogenic nature of a gain. Evaluation of the guidelines in the second cohort of 300 patients revealed that the interpretation guidelines were clear, easy to follow and efficient
MuPix and ATLASPix -- Architectures and Results
High Voltage Monolithic Active Pixel Sensors (HV-MAPS) are based on a
commercial High Voltage CMOS process and collect charge by drift inside a
reversely biased diode. HV-MAPS represent a promising technology for future
pixel tracking detectors. Two recent developments are presented. The MuPix has
a continuous readout and is being developed for the Mu3e experiment whereas the
ATLASPix is being developed for LHC applications with a triggered readout. Both
variants have a fully monolithic design including state machines, clock
circuitries and serial drivers. Several prototypes and design variants were
characterised in the lab and in testbeam campaigns to measure efficiencies,
noise, time resolution and radiation tolerance. Results from recent MuPix and
ATLASPix prototypes are presented and prospects for future improvements are
discussed.Comment: 10 pages, proceedings, The 28th International Workshop on Vertex
Detectors (VERTEX 2019), 13 - 18 Oct 2019, Lopud Island, Croati
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