MoTe2 is an exfoliable transition metal dichalcogenide (TMD) that crystallizes in three symmetries: the semiconducting trigonal-prismatic 2H- or α-phase, the semimetallic and monoclinic 1T′- or ...β-phase, and the semimetallic orthorhombic γ-structure. The 2H-phase displays a band gap of ∼1 eV making it appealing for flexible and transparent optoelectronics. The γ-phase is predicted to possess unique topological properties that might lead to topologically protected nondissipative transport channels. Recently, it was argued that it is possible to locally induce phase-transformations in TMDs, through chemical doping, local heating, or electric-field to achieve ohmic contacts or to induce useful functionalities such as electronic phase-change memory elements. The combination of semiconducting and topological elements based upon the same compound might produce a new generation of high performance, low dissipation optoelectronic elements. Here, we show that it is possible to engineer the phases of MoTe2 through W substitution by unveiling the phase-diagram of the Mo1–x W x Te2 solid solution, which displays a semiconducting to semimetallic transition as a function of x. We find that a small critical W concentration x c ∼ 8% stabilizes the γ-phase at room temperature. This suggests that crystals with x close to x c might be particularly susceptible to phase transformations induced by an external perturbation, for example, an electric field. Photoemission spectroscopy, indicates that the γ-phase possesses a Fermi surface akin to that of WTe2.
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IJS, KILJ, NUK, PNG, UL, UM
Mg-0.5Sn-(0, 0.3 wt%) Y alloys were obtained by casting with a metal mould, then extruded to acquire the as-extruded sheets. The microstructures, and mechanical properties of the alloys were studied. ...The results indicated that Sn3Y5 particles generated after the addition of Y into the Mg–Sn alloys. This contributed to the presence of fine grains in the extruded Mg-0.5Sn-0.3Y sheets, the size of which decreased from ∼16 μm to ∼4 μm, accompanied by a significant improvement in the mechanical properties. Specifically, with Y addition, the ultimate tensile strength and elongation along the extrusion direction increased by 21% and 191%, respectively. The crystallographic matching relationships between Sn3Y5 and Mg were established via an edge-to-edge matching model. The calculated results illustrated that Sn3Y5 had small crystallographic misorientation with α-Mg, and served as the sites of heterogeneous nucleation for the Mg matrix, which led to grain refinement of Mg-0.5Sn-0.3Y sheets. Meanwhile, the diffraction patterns obtained by transmission electron microscopy along 0001Mg // 112‾3‾Sn3Y5 well agreed with the simulation results and validated the prediction. Furthermore, the macro-texture and work hardening behaviour of the extruded sheets implied that in the tensile test, the as-extruded Mg-0.5Sn-0.3Y sheets underwent both basal and prismatic slips, while only the basal slip was observed in Mg-0.5Sn. As more slip systems were activated and more mobile dislocations could be formed, this in combination with the fine-grain strengthening effect, resulted in the large tensile elongation and high tensile strength of the Mg-0.5Sn-0.3Y sheets.
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•The grain size decreased by ∼78% in Mg-0.5Sn sheet with Y addition.•Both the strength and ductility of Mg-0.5Sn-0.3Y sheet were enhanced.•Sn3Y5 have small crystallographic misorientation with matrix, serving as the heterogeneous nucleation sites.•Mg-0.5Sn-0.3Y sheet experienced both basal and prismatic slip, while Mg-0.5Sn only endured basal slip.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The increasing demands of energy storage require the significant improvement of current Li‐ion battery electrode materials and the development of advanced electrode materials. Thus, it is necessary ...to gain an in‐depth understanding of the reaction processes, degradation mechanism, and thermal decomposition mechanisms under realistic operation conditions. This understanding can be obtained by in situ/operando characterization techniques, which provide information on the structure evolution, redox mechanism, solid‐electrolyte interphase (SEI) formation, side reactions, and Li‐ion transport properties under operating conditions. Here, the recent developments in the in situ/operando techniques employed for the investigation of the structural stability, dynamic properties, chemical environment changes, and morphological evolution are described and summarized. The experimental approaches reviewed here include X‐ray, electron, neutron, optical, and scanning probes. The experimental methods and operating principles, especially the in situ cell designs, are described in detail. Representative studies of the in situ/operando techniques are summarized, and finally the major current challenges and future opportunities are discussed. Several important battery challenges are likely to benefit from these in situ/operando techniques, including the inhomogeneous reactions of high‐energy‐density cathodes, the development of safe and reversible Li metal plating, and the development of stable SEI.
Recent developments of the five important in situ/operando characterization categories for lithium battery research are summarized, including X‐ray, electron, neutron, optical, and scanning probe techniques. For each technique, the operating principles and in situ cell design are described in detail, including representative studies of typical electrode materials and related processes summarized in tables for easy comparison and cross reference.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
To evaluate the potential effect of interaction between breastfeeding and environmental tobacco smoke (ETS) exposure on respiratory health, we studied 31 049 children (aged 2–14 years) from 25 ...districts of seven cities in northeast China. Parents of the children completed standardized questionnaires that characterized the children's histories of respiratory symptoms and illness, feeding methods, ETS exposure, and other associated risk factors. Breastfeeding was defined as having been mainly breastfed for 3 months or more. The results showed that the association of ETS exposure with childhood respiratory conditions/diseases was modified by breastfeeding, and the association for nonbreastfed children was stronger than that for breastfed children. In particular, for nonbreastfed children, the odds ratios (ORs) for the effect of current ETS exposure asthma was 1.71 (95% CI: 1.43–2.05); however, the OR for breastfed children was 1.33 (95% CI: 1.20–1.48), indicating that the interactions between breastfeeding and current ETS exposure on asthma were statistically significant (P = 0.019). When stratified by school (kindergarten vs. elementary school), breastfeeding was more protective for asthma‐related symptoms among children from kindergarten. In conclusion, this study shows that breastfeeding is associated with smaller associations between ETS exposure and respiratory conditions in children, suggesting that breastfeeding reduces susceptibility to the respiratory effects of ETS.
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DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
To investigate the rate of periprosthetic joint infection (PJI) revision surgeries and clinical information of hip-/knee- PJI cases nationwide from 2015 to 2017 in China.
An epidemiological ...investigation. A self-designed questionnaire and convenience sampling were used to survey 41 regional joint replacement centers nationwide from November 2018 to December 2019 in China. The PJI was diagnosed according to the Musculoskeletal Infection Association criteria. Data of PJI patients were obtained by searching the inpatient database of each hospital. Questionnaire entries were extracted from the clinical records by specialist. Then the differences in rate of PJI revision surgery between hip- and knee- PJI revision cases were calculated and compared.
Total of 36 hospitals (87.8%) nationwide reported data on 99 791 hip and knee arthroplasties performed from 2015 to 2017, with 946 revisions due to PJI (0.96%). The overall hip-PJI revision rate was 0.99% (481/48 574), and it was 0.97% (135/13 963), 0.97% (153/15 730) a
Abstract
A piled-up neutron-gamma discrimination system is designed
to discriminate single and piled-up events under high counting
rate. The data acquired by a Cs
2
LiLaBr
6
:Ce (CLLB) detector
and ...an Am-Be neutron source are used to train and test the model in
the n-
γ
discrimination system. The charge comparison method
is applied to discriminate the non-piled-up events in the
experimental data and label the dataset of single events. As a
result of the method, the figure-of-merit (FOM) value is 1.10, which
indicates that the wrong labeling ratio is about 0.248%. A dataset
of piled-up events is created by adding up waveforms and labels of
the events in the single-pulse dataset. The discrimination system
consists of three convolutional models, called Model_PulseNum,
Model_OnePulse and Model_TwoPulses. All the models are trained and
tested by the created dataset. Model_PulseNum is created and
trained to define the number of pulses in the waveform of the event,
with an accuracy of 99.94%. The other two models (Model_OnePulse
and Model_TwoPulses) are created and trained to discriminate the
particle types for non-piled-up and two-fold piled-up events with
the accuracy of 99.5% and 98.6%, respectively. For the whole
discrimination system, the accurcy for the particle identification
is over 97% for each class (
γ
, n,
γ
+
γ
,
γ
+ n, n +
γ
and n + n). These results indicate that CNN model can
improve the performance of particle detection systems by effectively
discriminate neutron and gamma for both piled-up and non-piled-up
events under high counting rates.
Despite the association of childhood blood pressure (BP) with hypertension later in the life course, there remains dearth of information regarding the prevalence and emergence of hypertension in ...children, especially in China. To investigate the current status of BP, prevalence of elevated BP and related factors in Chinese children, a cross-sectional survey in a representative sample of 9354 Chinese children 5-17 years old was conducted in seven cities in Northeastern China during 2011 and 2012. BP measurements were taken by mercury sphygmomanometer. Elevated BP in children was defined as an average diastolic BP or systolic BP that is in the 95th percentile or higher for their gender, age and height. Overall, total prevalence of elevated BP was 13.8%, and no significant difference between males and females was identified. Multivariate analyses revealed that children having a higher area of residence had a lower of elevated BP. Increased odds for elevated BP were found for individuals who were lean (odds ratio (OR)=2.12; 95% confidence interval (CI): 1.67-2.69), overweight (OR=2.05; 95% CI: 1.74-2.42), obese (OR=3.15; 95% CI: 2.70-3.68), were born with low birth weight (OR=1.26; 95%CI: 1.01-1.63), premature birth (OR=1.46; 95%CI: 1.13-1.88), and were with home coal use (OR=1.24; 95%CI: 1.02-1.52). In conclusion, elevated BP was found to be prevalent in children in urban areas of Northeast China. These results underscore the importance of implementing a package of measures aimed at reducing malleable risk for this cardiovascular condition in school-aged children in Northeast China.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Elevated expression of Siglec-1 on circulating monocytes has been reported in some inflammatory and autoimmune diseases, but its expression and role in RA has not been elucidated. The aims of this ...study were to determine the expression of Siglec-1 in peripheral blood and to explore its role in mononuclear cell reactivity to autoantigen in RA.
Siglec-1 protein and mRNA levels in 42 RA patients, 39 OA patients, 28 SLE patients and 42 normal controls were determined by flow cytometry and quantitative RT-PCR, respectively. In addition, 10 patients with active RA received DMARDs for 12 weeks and the frequencies of Siglec-1-positive cells and the 28-joint DAS (DAS28) were assessed before and after therapy. Furthermore, TNF-α, IFN-γ and type II collagen were used to up-regulate Siglec-1. Peripheral blood mononuclear cells (PBMCs) from different groups were stimulated with mitogens or antigens and cell proliferation and cytokine production were determined.
The protein and mRNA levels of Siglec-1 on PBMCs and monocytes in RA patients were significantly higher than those in OA patients and healthy controls. Moreover, the expression of Siglec-1 protein on PBMCs was positively correlated with DAS28, ESR, high-sensitivity CRP and IgM-RF, but not with anti-CCP antibody. Interestingly, Siglec-1 expression was decreased in parallel with the decrease in the DAS28 after 12 weeks of anti-rheumatic treatment. Furthermore, TNF-α, IFN-γ and type II collagen can up-regulate Siglec-1 in PBMCs. Elevated PBMC proliferation and proinflammatory cytokine production to collagen stimulation in RA patients decreased when Siglec-1 was inhibited by anti-Siglec-1 antibodies.
Elevated Siglec-1 expression in PBMCs and monocytes can potentially serve as a biomarker for monitoring disease activity in RA. Siglec-1 may also play a proinflammatory role in stimulating lymphocyte proliferation and activation in RA.
Heterogeneous wireless networks have emerged as a new paradigm to meet the fast growing wireless network capacity and coverage demands. Due to the co-deployment of high power and low power nodes in ...the same network using the same spectrum, more advanced interference coordination and radio resource management schemes are required than in the traditional cellular network in order to achieve a high network capacity and good user experience. In this paper, we propose an optimal fractional frequency reuse and power control scheme that can effectively coordinate the interference among high power and low power nodes. The scheme can be optimized to maximize the sum of the long term log-scale throughput among all the user equipments (UEs). Towards that end, the Lagrange dual function is first derived for the proposed optimization problem. Gradient descent method is then used to search the optimal solution for the convex dual problem. Due to the strong duality condition, the optimal solution for the dual problem is also the optimal solution for the primal problem. Simulation results show that the proposed scheme can greatly improve the wireless heterogeneous network performance on system capacity and user experience.
A total of 100 osteoarthritis patients undergoing unilateral total knee arthroplasty were randomly assigned to receive either a multimodal analgesia protocol, comprising oral celecoxib and tramadol ...before and after surgery and intra-articular injection of large doses of morphine, ropivacaine, adrenaline and betamethasone during surgery (trial group), or oral and intra-articular placebo (control group). All patients received patient-controlled analgesia for 48 h after surgery. Morphine consumption up to 48 h after surgery was significantly lower in the trial than in the control group. Compared with the control group, the trial group had significantly lower visual analogue scale (VAS) scores for pain at rest from 6 h to 7 days after surgery and significantly lower VAS scores during activity from 24 h to 7 days after surgery. Active straight leg raise and active 90° knee flexion were achieved sooner and range of knee movement at postoperative days 1–15 were significantly greater in the trial group. Postoperative wound healing, infection, blood pressure, heart rate, rash, respiratory depression, urinary retention and deep vein thrombosis were similar in the two groups, but nausea and vomiting were significantly less frequent in the trial group.
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