288 research outputs found
Evidence-based rules from family practice to inform family practice; The learning healthcare system case study on urinary tract infections
Background: Analysis of encounter data relevant to the diagnostic process sourced from routine electronic medical record (EMR) databases represents a classic example of the concept of a learning healthcare system (LHS). By collecting International Classification of Primary Care (ICPC) coded EMR data as part of the Transition Project from Dutch and Maltese databases (using the EMR TransHIS), data mining algorithms can empirically quantify the relationships of all presenting reasons for encounter (RfEs) and recorded diagnostic outcomes. We have specifically looked at new episodes of care (EoC) for two urinary system infections: simple urinary tract infection (UTI, ICPC code: U71) and pyelonephritis (ICPC code: U70). Methods: Participating family doctors (FDs) recorded details of all their patient contacts in an EoC structure using the ICPC, including RfEs presented by the patient, and the FDs' diagnostic labels. The relationships between RfEs and episode titles were studied using probabilistic and data mining methods as part of the TRANSFoRm project. Results: The Dutch data indicated that the presence of RfE's "Cystitis/Urinary Tract Infection", "Dysuria", "Fear of UTI", "Urinary frequency/urgency", "Haematuria", "Urine symptom/complaint, other" are all strong, reliable, predictors for the diagnosis "Cystitis/Urinary Tract Infection". The Maltese data indicated that the presence of RfE's "Dysuria", "Urinary frequency/urgency", "Haematuria" are all strong, reliable, predictors for the diagnosis "Cystitis/Urinary Tract Infection". The Dutch data indicated that the presence of RfE's "Flank/axilla symptom/complaint", "Dysuria", "Fever", "Cystitis/Urinary Tract Infection", "Abdominal pain/cramps general" are all strong, reliable, predictors for the diagnosis "Pyelonephritis". The Maltese data set did not present any clinically and statistically significant predictors for pyelonephritis. Conclusions: We describe clinically and statistically significant diagnostic associations observed between UTIs and pyelonephritis presenting as a new problem in family practice, and all associated RfEs, and demonstrate that the significant diagnostic cues obtained are consistent with the literature. We conclude that it is possible to generate clinically meaningful diagnostic evidence from electronic sources of patient data
Green Up-Conversion Continuous-Wave Er3+Liyf4 Laser At Room-Temperature
We report room-temperature upconversion pumped continuous wave laser emission of 1% Er3+:LiYF4 at 551 nm excited by a Ti:sapphire laser at 810 nm. Output powers of up to 40 mW with output coupling of 6.6% have been obtained by using nearly concentric resonator design
Spectroscopy And Green Up-Conversion Laser-Emission Of Er(3+)-Doped Crystals At Room-Temperature
The spectroscopic parameters of Er3+-doped crystals were determined with regard to the upconversion laser parameters of the green transition S-4(3/2) -- \u3e I-4(15/2), The influence of excited-state absorption on this laser channel was determined. Furthermore, upconversion pump mechanisms using ground-state and excited-state absorption around 810 and 970 nm were investigated by direct measurements of excited-state absorption. The spectroscopic results confirm the pulsed room-temperature laser experiments on the S-4(3/2) -- \u3e I-5(5/2) transition. The lasers based on Er:LiYF4, Er:Y3Al5O12, and Er:Lu3Al5O12 were directly excited into the upper laser level by an excimer laser pumped dye laser in the blue spectral range. In Er:LiYF4, Er:KYF4, and Er:Y3Al5O12, laser action was achieved with two-step upconversion pumping by a Ti:sapphire laser and a krypton ion laser. In the case of the fluorides, the additional pumping with the krypton ion laser was not necessary. The laser emission wavelengths were 551 nm for Er:LiYF4, 561 nm for Er:Y3Al5012 and Er:Lu3Al5O12, and 562 nm for Er:KYF4. In addition, green quasi-cw laser emission of Er:LiYF4 pumped with an argon-ion laser was realized at room temperature
Chiral molecule formation in interstellar ice analogs: alpha-aminoethanol NH 2 CH(CH 3 )OH
International audienceAims. Aminoalcohol molecules such as alpha-aminoethanol NH 2 CH(CH 3)OH may be aminoacid precursors. We attempt to charac-terize and detect this kind of molecules which is important to establish a possible link between interstellar molecules and life as we know it on Earth. Methods. We use Fourier transform infrared (FTIR) spectroscopy and mass spectrometry to study the formation of alpha-aminoethanol NH 2 CH(CH 3)OH in H 2 O:NH 3 : CH 3 CHO ice mixtures. Isotopic substitution with 15 NH 3 and ab-initio calculation are used to confirm the identification of alpha-aminoethanol. Results. After investigating the thermal reaction of solid NH 3 and acetaldehyde CH 3 CHO at low temperature, we find that this reac-tion leads to the formation of a chiral molecule, the alpha aminoethanol NH 2 CH(CH 3)OH. For the first time, we report the infrared and mass spectra of this molecule. We also report on its photochemical behavior under VUV irradiation. We find that the main photo-product is acetamide (NH 2 COCH 3). Data provided in this work indicates that alpha-aminoethanol is formed in one hour at 120 K and suggests that its formation in warm interstellar environments such as protostellar envelopes or cometary environments is likely
Green Up-Conversion Laser-Emission In Er-Doped Crystals At Room-Temperature
We report room-temperature pulsed up-conversion laser oscillation in Er-doped LiYF4 and KYF4 at 551 and 562 nm, respectively. In both crystals laser oscillation is observed on the S-4(3/2)-I-4(15/2) ground state transition. Excitation was provided by a tunable flashlamp-pumped Ti:sapphire laser in the spectral region around 810 nm. Additional pumping with a continuous wave krypton ion laser at 647 nm was beneficial to both lasers. Laser action has also been observed in Er-doped Y3Al5O12 on the same transition
Experimental investigation of aminoacetonitrile formation through the Strecker synthesis in astrophysical-like conditions: reactivity of methanimine (CH2NH), ammonia (NH3), and hydrogen cyanide (HCN)
International audienceAstronomy & Astrophysics Experimental investigation of aminoacetonitrile formation through the Strecker synthesis in astrophysical-like conditions: reactivity of methanimine (CH 2 NH), ammonia (NH 3), and hydrogen cyanide (HCN) ABSTRACT Context. Studing chemical reactivity in astrophysical environments is an important means for improving our understanding of the origin of the organic matter in molecular clouds, in protoplanetary disks, and possibly, as a final destination, in our solar system. Laboratory simulations of the reactivity of ice analogs provide important insight into the reactivity in these environments. Here, we use these experimental simulations to investigate the Strecker synthesis leading to the formation of aminoacetonitrile in astrophysical-like conditions. The aminoacetonitrile is an interesting compound because it was detected in SgrB2, hence could be a precursor of the smallest amino acid molecule, glycine, in astrophysical environments. Aims. We present the first experimental investigation of the formation of aminoacetonitrile NH 2 CH 2 CN from the thermal processing of ices including methanimine (CH 2 NH), ammonia (NH 3), and hydrogen cyanide (HCN) in interstellar-like conditions without VUV photons or particules. Methods. We use Fourier Transform InfraRed (FTIR) spectroscopy to monitor the ice evolution during its warming. Infrared spec-troscopy and mass spectroscopy are then used to identify the aminoacetonitrile formation. Results. We demonstrate that methanimine can react with â CN during the warming of ice analogs containing at 20 K methanimine, ammonia, and [NH + 4 â CN] salt. During the ice warming, this reaction leads to the formation of poly(methylene-imine) polymers. The polymer length depend on the initial ratio of mass contained in methanimine to that in the [NH + 4 â CN] salt. In a methanimine excess, long polymers are formed. As the methanimine is progressively diluted in the [NH + 4 â CN] salt, the polymer length decreases until the aminoacetonitrile formation at 135 K. Therefore, these results demonstrate that aminoacetonitrile can be formed through the second step of the Strecker synthesis in astrophysical-like conditions
Hardware Trojan Detection by Delay and Electromagnetic Measurements
International audienceâHardware Trojans (HT) inserted in integrated circuits have received special attention of researchers. In this paper, we present firstly a novel HT detection technique based on path delays measurements. A delay model, which considers intra-die process variations, is established for a net. Secondly, we show how to detect HT using ElectroMagnetic (EM) measurements. We study the HT detection probability according to its size taking into account the inter-die process variations with a set of FPGA. The results show, for instance, that there is a probability greater than 95% with a false negative rate of 5% to detect a HT larger than 1.7% of the original circuit. I. Introduction The trust and security of Integrated Circuits (IC) design and fabrication is critical for sensitive fields like finance, health, and governmental communications. Due to the complexity and the high cost of IC fabrication cycle, more and more firms outsource their production. This trend gives a possibility for an adversary to introduce malicious circuit, called Hardware Trojan horse (HT), in any IC. It can either perform a Denial Of Service (DOS), deteriorate circuit performance [8], or steal sensitive information. Therefore, the HTs are considered a real threat which has gained attention from researchers. HT can be inserted at any point during the design or fabrication process from Register Transfer Level (RTL) to layout and circuit fabrication. For example in [11], authors show some techniques to insert malicious circuitry at RTL level. These HTs, which are activated with a specific pattern inputs, can leak secret key via RS232 channels. The HT, unlike a software trojan, cannot be removed once it is fabricated. So, it is better to proactively prevent the insertion of a HT: few methods have been proposed. One seminal work is known as " private circuits II " [9]. This paper describes a proof-of-concept, too costly to be implemented. A more reasonable option has been recently proposed in [5]: it uses two codes to encode the state and mix it with encoded randomness, which allows to prevent an easy triggering and has a detection capability. Otherwise it is important to detect it before it becomes effective. Previous works classify detection methods into two wide categories: destructive and non-destructive. Invasive methods destroy the chip to reconstruct successfully the GDSII an
Synthesis of Molecular Oxygen via Irradiation of Ice Grains in the Protosolar Nebula
Molecular oxygen has been detected in the coma of comet 67P/ChuryumovâGerasimenko with a mean abundance
of 3.80±0.85% by the ROSINA mass spectrometer on board the Rosetta spacecraft. To account for the presence
of this species in comet 67P/ChuryumovâGerasimenko, it has been shown that the radiolysis of ice grain
precursors of comets is a viable mechanism in low-density environments, such as molecular clouds. Here, we
investigate the alternative possibility that the icy grains present in the midplane of the protosolar nebula were
irradiated during their vertical transport between the midplane and the upper layers over a large number of cycles,
as a result of turbulent mixing. Consequently, these grains spent a non-negligible fraction of their lifetime in the
diskâs upper regions, where the irradiation by cosmic rays was strong. To do so, we used a coupled disk-transportirradiation
model to calculate the time evolution of the molecular oxygen abundance radiolytically produced in ice
grains. Our computations show that, even if a significant fraction of the icy particles has followed a back and forth
cycle toward the upper layers of the disk over tens of millions of years, a timespan far exceeding the formation
timescale of comet 67P/ChuryumovâGerasimenko, the amount of produced molecular oxygen is at least two
orders of magnitude lower than the Rosetta observations. We conclude that the most likely scenario remains the
formation of molecular oxygen in low-density environments, such as the presolar cloud, prior to the genesis of the
protosolar nebula
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