835 research outputs found
Giant spin-orbit splitting of point defect states in monolayer WS
The spin-orbit coupling (SOC) effect has been known to be profound in
monolayer pristine transition metal dichalcogenides (TMDs). Here we show that
point defects, which are omnipresent in the TMD membranes, exhibit even
stronger SOC effects and change the physics of the host materials drastically.
In this Article we chose the representative monolayer WS\sub{2} slabs from the
TMD family together with seven typical types of point defects including
monovacancies, interstitials, and antisites. We calculated the formation
energies of these defects, and studied the effect of spin-orbit coupling (SOC)
on the corresponding defect states. We found that the S monovacancy (V\sub{S} )
and S interstitial (adatom) have the lowest formation energies. In the case of
V\sub{S} and both of the W\sub{S and W\sub{S2} antisites, the defect states
exhibit giant splitting up to 296 meV when SOC is considered. Depending on the
relative position of the defect state with respect to the conduction band
minimum (CBM), the hybrid functional HSE will either increase the splitting by
up to 60 meV (far from CBM), or decrease the splitting by up to 57 meV (close
to CBM). Furthermore, we found that both the W\sub{S} and W\sub{S2} antisites
possess a magnetic moment of 2 localized at the antisite W atom and
the neighboring W atoms. All these findings provide new insights in the defect
behavior under SOC point to new possibilities for spintronics applications for
TMDs.Comment: 8 pages, 6 figure
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Secondary acute lymphoblastic leukemia is a distinct clinical entity with prognostic significance.
The effect of prior malignancy on the risk of developing, and prognosis of, acute lymphoblastic leukemia (ALL) is unknown. This observational study utilized the California Cancer Registry to estimate the risk of developing ALL after a prior malignancy using standardized incidence ratios (SIRs, 95% confidence intervals). ALL occurring after a malignancy with an SIR>1 (increased-risk (IR) malignancies) was considered secondary ALL (s-ALL). Adjusted hazard ratios (aHRs, 95% confidence intervals) compared the effect of s-ALL with de novo ALL on overall survival. A total of 14ā481 patients with ALL were identified (1988-2012) and 382 (3%) had a known prior malignancy. Any prior malignancy predisposed patients to developing ALL: SIR 1.62 (1.45-1.79). Hematologic malignancies (SIR 5.57, 4.38-6.98) and IR-solid tumors (SIR 2.11, 1.73-2.54) increased the risk of developing ALL. s-ALL increased the risk of death compared with de novo ALL (aHR 1.38 (1.16-1.63)) and this effect was more pronounced among younger patients (age<40 years: aHR 4.80 (3.15-7.30); ageā©¾40 years: aHR 1.40 (1.16-1.69)) (interaction P<0.001). This population-based study demonstrates that s-ALL is a distinct entity that occurs after specific malignancies and carries a poor prognosis compared with de novo ALL, particularly among patients <40 years of age
SafeWeb: A Middleware for Securing Ruby-Based Web Applications
Web applications in many domains such as healthcare and finance must process sensitive data, while complying with legal policies regarding the release of different classes of data to different parties. Currently, software bugs may lead to irreversible disclosure of confidential data in multi-tier web applications. An open challenge is how developers can guarantee these web applications only ever release sensitive data to authorised users without costly, recurring security audits.
Our solution is to provide a trusted middleware that acts as a āsafety netā to event-based enterprise web applications by preventing harmful data disclosure before it happens. We describe the design and implementation of SafeWeb, a Ruby-based middleware that associates data with security labels and transparently tracks their propagation at different granularities across a multi-tier web architecture with storage and complex event processing. For efficiency, maintainability and ease-of-use, SafeWeb exploits the dynamic features of the Ruby programming language to achieve label propagation and data flow enforcement. We evaluate SafeWeb by reporting our experience of implementing a web-based cancer treatment application and deploying it as part of the UK National Health Service (NHS)
Recovery from Developmental Nonylphenol Exposure is Possible I. Male
Nonylphenol (NP) is an environmental endocrine-disrupting chemical (EDC) that has been detected in human cord blood and milk. It is unavoidable that human fetus and infant exposure to this environmental contaminant. According to āfetal origins adult diseaseā hypothesis, the biological impact and healthcare will encounter unavoidable impact. We previously observed that developmental NP exposure led to increased body weight, elevated plasma ACTH, higher production and concentrations of corticosterone and aldosterone, and more 11?-hydroxysteroid dehydrogenase I (11?-HSD1) expression/activity during the first generation at the adult stage. With these phenomena, is human going to evolution to a heavier with metabolic syndrome state or back to ādefault stateā after generation(s) of hygienic up. This study addressed the possibility of recovering from NP exposure. Female rats were timed-mated in this experiment. Throughout gestation and lactation, one group of pregnant females was given a 2? Āµg/ml NP drinking solution and another group was given water. The litters were marked as first-generation F1 NP or F1 Veh offspring. At approximately 13 weeks of age, the F1 females were timed-mated with non-sibling F1 males from identical prenatal and neonatal treatment groups. The females were not manipulated in any way. The resulting litters were designated as the second-generation F2 NP or F2 Veh offspring. At 13 weeks of age, the male offspring from each F1 and F2 group were decapitated. The experimental results showed that NP exposure resulted in F1 offspring hyperadrenalism and weight increases. These effects were not observed in the F2 offspring. The F2 generation status was set back to the ādefaultā stage, which shows the elevated body weight and hyperadrenalism returned to normal. This study indicates developmental exposure to NP results in life long impact. The recovery to ādefault stateā is possible only after generation(s) suffer with expensive healthcare burden. Keywords: NP, developmental exposure, 11?-HSD1, body weight, hyperadrenalis
Magnetostriction and elasticity of body centered cubic Fe100āxBex alloys
Magnetostriction measurements from 77 K to room temperature on oriented (100) and (110) disk samples of Fe93.9Be6.1 and Fe88.7Be11.3 reveal substantial increases in Ī»100compared to iron. For the 11.3% alloy, Ī»100=110āppm, a sixfold increase above that of Ī±-Fe. For the 6.1% alloy, Ī»100=81āppm, ā¼40% and ā¼170% greater than Ī»100 of comparable FeāGa and FeāAl alloys, respectively, for H=15ākOe. Large differences exist between the values of Ī»100 and Ī»111 (Ī»100\u3e0,āĪ»111\u3c0) and their temperature dependencies. Elastic constants, c11, c12, and c44, from 4 to 300 K were obtained on the same FeāBe alloys. From these measurements, the magnetoelastic energy coefficients b1 and b2 were calculated. While the magnitudes of the magnetostrictions Ī»100 and Ī»111 are widely different, the magnitudes of b1 and b2 are within a factor of 2. The FeāBe alloys are highly anisotropic magnetostrictively, elastically, and magnetoelastically. For Fe88.7Be11.3 at room temperature Ī»100/Ī»111, 2c44/(c11āc12), and b1/b2 are ā6.6, 3.55, and ā1.86, respectively
Temperature dependence of the magnetostriction and magnetoelastic coupling in Fe100āxAlx (x = 14.1,16.6,21.5,26.3) and Fe50Co50
In this paper, we report magnetostriction measurements, (Ī»100) on Fe-rich FeāAl alloys and Fe50Co50 as functions of temperature from 77āK to room temperature (RT). From these measurements and elastic constant (cā²) measurements, the tetragonal magnetoelastic coupling constants (b1ās) were calculated. Significant differences were found between our RT measurements and earlier magnetostriction measurements for the higher Al concentration alloys (16.6%, 21.5%, 26.3% Al) and the Fe50Co50 alloy. Reminiscent of the temperature dependence of Ī»100 for pure Fe, magnetostriction changes with temperature are minimal for FeāAl alloys having the disordered bcc (A2)structure (x\u3c19% Al). In contrast, the alloy possessing the ordered (D03) structure shows an anomalous decrease in magnetostriction in Ī»100 with decreasing temperature. For the FeāAl alloy system, the magnetoelastic coupling constant, ā£b1ā£, exhibits a peak at room temperature maximizing at 16.6% Al with a value of 12.3āMJ/m3. For Fe50Co50, ā£b1ā£ was calculated to be ā¼ 34āMJ/m3 at room temperature
Effect of interstitial additions on magnetostriction in FeāGa alloys
The additions of trace amounts of small interstitial atoms (carbon, boron, and nitrogen) to FeāGa (Galfenol) alloys have a small but beneficial effect on the magnetostriction of FeāGa alloys especially at high Ga compositions. The saturated magnetostrictions [(3/2)Ī»100ās] of both slow cooled and quenched single crystal FeāGaāC alloys with Ga contents \u3e18āat.ā% are about 10%ā30% higher than those of the comparable binary FeāGa alloys. For boron and nitrogen additions, the magnetostrictions of slow cooled alloys with Ga content \u3e18āat.ā% were approximately 20% higher than those of the binary FeāGa alloys. We assume that these small atoms enter interstitially into the octahedral site as in pure Ī±-Fe and inhibit chemical ordering, resulting in increased Ī»100. Thermal analysis of the FeāGa binary alloys and FeāGaāC ternary alloys indicates that the addition of C into the FeāGa system decreases the formation kinetics of D03 and extends the disordered region beyond the maximum for slow cooled binary samples
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