Many non-equilibrium phenomena have been discovered or predicted in optically-driven quantum solids
. Examples include light-induced superconductivity
and Floquet-engineered topological phases
. ...These are short lived effects that should lead to measurable changes in electrical transport, which can be characterized using an ultrafast device architecture based on photoconductive switches
. Here, we report the observation of a light-induced anomalous Hall effect in monolayer graphene driven by a femtosecond pulse of circularly polarized light. The dependence of the effect on a gate potential used to tune the Fermi level reveals multiple features that reflect a Floquet-engineered topological band structure
, similar to the band structure originally proposed by Haldane
. This includes an approximately 60 meV wide conductance plateau centered at the Dirac point, where a gap of equal magnitude is predicted to open. We find that when the Fermi level lies within this plateau, the estimated anomalous Hall conductance saturates around 1.8±0.4 e
/h.
Abstract
Excitation of high-
T
c
cuprates and certain organic superconductors with intense far-infrared optical pulses has been shown to create non-equilibrium states with optical properties that are ...consistent with transient high-temperature superconductivity. These non-equilibrium phases have been generated using femtosecond drives, and have been observed to disappear immediately after excitation, which is evidence of states that lack intrinsic rigidity. Here we make use of a new optical device to drive metallic K
3
C
60
with mid-infrared pulses of tunable duration, ranging between one picosecond and one nanosecond. The same superconducting-like optical properties observed over short time windows for femtosecond excitation are shown here to become metastable under sustained optical driving, with lifetimes in excess of ten nanoseconds. Direct electrical probing, which becomes possible at these timescales, yields a vanishingly small resistance with the same relaxation time as that estimated by terahertz conductivity. We provide a theoretical description of the dynamics after excitation, and justify the observed slow relaxation by considering randomization of the order-parameter phase as the rate-limiting process that determines the decay of the light-induced superconductor.
8q24.21 is a frequently amplified genomic region in colorectal cancer (CRC). This region is often referred to as a ‘gene desert’ due to lack of any important protein-coding genes, highlighting the ...potential role of noncoding RNAs, including long noncoding RNAs (lncRNAs) located around the proto-oncogeneMYC. In this study, we have firstly evaluated the clinical significance of altered expression of lncRNAs mapped to this genomic locus in CRC.
A total of 300 tissues, including 280 CRC and 20 adjacent normal mucosa specimens were evaluated for the expression of 12 lncRNAs using qRT-PCR assays. We analyzed the associations between lncRNA expression and various clinicopathological features, as well as with recurrence free survival (RFS) and overall survival (OS) in two independent cohorts.
The expression of CCAT1, CCAT1-L, CCAT2, PVT1, and CASC19 were elevated in cancer tissues (P=0.039, <0.001, 0.018, <0.001, 0.002, respectively). Among these, high expression of CCAT1 and CCAT2 was significantly associated with poor RFS (P=0.049 and 0.022, respectively) and OS (P=0.028 and 0.015, respectively). These results were validated in an independent patient cohort, in which combined expression of CCAT1 and CCAT2 expression was significantly associated with a poor RFS (HR:2.60, 95% confidence interval CI: 1.04–6.06,P=0.042) and a poor OS (HR:8.38, 95%CI: 2.68–37.0,P<0.001). We established a RFS prediction model which revealed that combined expression of CCAT1, CCAT2, and carcinoembryonic antigen was a significant determinant for efficiently predicting RFS in stage II (P=0.034) and stage III (P=0.001) CRC patients.
Several lncRNAs located in 8q24.21 locus are highly over-expressed in CRC. High expression of CCAT1 and CCAT2 significantly associates with poor RFS and OS. The expression of these two lncRNAs independently, or in combination, serves as important prognostic biomarkers in CRC.
Particles are often electrostatically charged by frictional contact during powder-handling operations. This phenomenon is called ‘triboelectric charging’ or ‘contact electrification’. The charged ...particles cause problems such as particle deposition and adhesion. In addition, if particles are excessively charged, an electrostatic discharge may occur, which can pose a risk of fire and explosion hazards; thus, to mitigate the adverse effects, it is important to elucidate the underlying triboelectric charging mechanisms. The electrostatics is, on the other hand, very useful in a number of applications that have been developed using the principles. In this review, the basic concepts and theories of charge transfer between solid surfaces are summarized, and chemical factors depending on materials and environmental effects are described. To theoretically analyze the process of particle charging, relevant models are discussed. Using the models, particle charging by repeated impacts on a wall is formulated. To experimentally evaluate particle charging, measurement and characterization methods are outlined. Furthermore, important applications and computer simulations are described.
To perform a systematic review to answer ‘In adults with attempted resuscitation after non-traumatic cardiac arrest does care at a specialised cardiac arrest centre (CAC) compared to care in a ...healthcare facility not designated as a specialised cardiac arrest centre improve patient outcomes?’
The PRISMA guidelines were followed. We searched bibliographic databases (Embase, MEDLINE and the Cochrane Library (CENTRAL)) from inception to 1st August 2018. Randomised controlled trials (RCTs) and non-randomised studies were eligible for inclusion. Two reviewers independently scrutinized studies for relevance, extracted data and assessed quality of studies. Risk of bias of studies and quality of evidence were assessed using ROBINS-I tool and GRADEpro respectively. Primary outcomes were survival to 30 days with favourable neurological outcomes and survival to hospital discharge with favourable neurological outcomes. Secondary outcomes were survival to 30 days, survival to hospital discharge and return of spontaneous circulation (ROSC) post-hospital arrival for patients with ongoing resuscitation. This systematic review was registered in PROSPERO (CRD 42018093369)
We included data from 17 observational studies on out-of-hospital cardiac arrest (OHCA) patients in meta-analyses. Overall, the certainty of evidence was very low. Pooling data from only adjusted analyses, care at CAC was not associated with increased likelihood of survival to 30 days with favourable neurological outcome (OR 2.92, 95% CI 0.68–12.48) and survival to 30 days (OR 2.14, 95% CI 0.73–6.29) compared to care at other hospitals. Whereas patients cared for at CACs had improved survival to hospital discharge with favourable neurological outcomes (OR 2.22, 95% CI 1.74–2.84) and survival to hospital discharge (OR 1.85, 95% CI 1.46–2.34).
Very low certainty of evidence suggests that post-cardiac arrest care at CACs is associated with improved outcomes at hospital discharge. There remains a need for high quality data to fully elucidate the impact of CACs.
Abstract
Optically driven quantum materials exhibit a variety of non-equilibrium functional phenomena, which to date have been primarily studied with ultrafast optical, X-Ray and photo-emission ...spectroscopy. However, little has been done to characterize their transient electrical responses, which are directly associated with the functionality of these materials. Especially interesting are linear and nonlinear current-voltage characteristics at frequencies below 1 THz, which are not easily measured at picosecond temporal resolution. Here, we report on ultrafast transport measurements in photo-excited K
3
C
60
. Thin films of this compound were connected to photo-conductive switches with co-planar waveguides. We observe characteristic nonlinear current-voltage responses, which in these films point to photo-induced granular superconductivity. Although these dynamics are not necessarily identical to those reported for the powder samples studied so far, they provide valuable new information on the nature of the light-induced superconducting-like state above equilibrium T
c
. Furthermore, integration of non-equilibrium superconductivity into optoelectronic platforms may lead to integration in high-speed devices based on this effect.
Martian surface morphology implies that Mars was once warm enough to maintain persistent liquid water on its surface. While the high D/H ratios (∼6 times the Earth's ocean water) of the current ...martian atmosphere suggest that significant water has been lost from the surface during martian history, the timing, processes, and the amount of the water loss have been poorly constrained. Recent technical developments of ion-microprobe analysis of martian meteorites have provided accurate estimation of hydrogen isotope compositions (D/H) of martian water reservoirs at the time when the meteorites formed. Based on the D/H data from the meteorites, this study demonstrates that the water loss during the pre-Noachian (>41–99 m global equivalent layers, GEL) was more significant than in the rest of martian history (>10–53 m GEL). Combining our results with geological and geomorphological evidence for ancient oceans, we propose that undetected subsurface water/ice (≃100–1000 m GEL) should exist, and it exceeds the observable present water inventory (≃20–30 m GEL) on Mars.
•Evolution of martian water inventory was estimated based on D/H data from martian meteorites.•Water loss during the pre-Noachian was more significant than in the rest of martian history.•Undetected subsurface water/ice should have existed and it exceeds the observable present water inventory on Mars.
Higher body mass index appears protective in hemodialysis patients, although it remains to be determined which component of muscle or fat mass is primarily associated with this survival advantage.
...Eighty-one hemodialysis patients in our institution were prospectively followed from July 2011 to August 2015. Muscle and fat mass were evaluated by measuring the cross-sectional areas of the thigh and abdomen using computed tomography. The relationship between muscle and fat mass, and all-cause and cardiovascular mortality was studied using the Kaplan-Meier analyses and multivariate Cox proportional hazard models.
During more than 4 years of follow-up, 26 patients (32%) died. In the Kaplan-Meier curve analyses, lower thigh muscle mass was significantly associated with all-cause and cardiovascular mortality (log-rank test, P<0.01 and P<0.001, respectively), but there was no such association with thigh fat, abdominal muscle and fat mass levels. In multivariate Cox proportional hazard models, each 0.1 cm
/kg increase in the thigh muscle area adjusted by dry weight was associated with an estimated 22% lower risk of all-cause mortality (95% confidence interval (95% CI), 0.64-0.95, P<0.05) and a 30% lower risk of cardiovascular mortality (95% CI, 0.54-0.90, P<0.01).
Lower thigh muscle mass is significantly associated with all-cause and cardiovascular mortality in hemodialysis patients. Our findings indicate the importance of focusing on the muscle mass of lower extremities to predict the clinical outcomes of hemodialysis patients.
The dissimilar lap joints of commercially brass (Cu–40Zn) to plain carbon steel (S25C) were fabricated using friction stir welding. The relationship between welding speed and heat input during the ...friction stir welding processes was discussed. The effect of welding speed on microstructures and mechanical properties of brass/S25C dissimilar joints was investigated. The grain size, Vickers hardness at the stirred zone and tensile shear fracture load of the joints varied significantly with the change of welding speed. The transmission electron microscope observations and energy dispersive X-ray spectrometry line analyses at the interface revealed that a mutual diffusion zone of Cu, Zn and Fe, the dominant elements of each plate was formed at the interface. The microstructure evolution and the joining mechanism of the brass/S25C joint are systematically discussed.
Display omitted
•The brass and steel were tightly bonded together.•Joint properties varied significantly with the change of welding speed.•Mutual diffusion zone was formed at the interface.•No intermetallic compound was observed at the interface.
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