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An advantage of the powder-bed-based metal additive manufacturing (AM) processes is that the powder can be reused. The powder reuse or recycling times directly affect the affordability of the additively manufactured parts, especially for the AM of titanium parts. This study examines the influence of powder reuse times on the characteristics of Ti-6Al-4V powder, including powder composition, particle size distribution (PSD), apparent density, tap density, flowability, and particle morphology. In addition, tensile samples were manufactured and evaluated with respect to powder reuse times and sample locations in the powder bed. The following findings were made from reusing the same batch of powder 21 times for AM by selective electron beam melting: (i) the oxygen (O) content increased progressively with increasing reuse times but both the Al content and the V content remained generally stable (a small decrease only); (ii) the powder became less spherical with increasing reuse times and some particles showed noticeable distortion and rough surfaces after being reused 16 times; (iii) the PSD became narrower and few satellite particles were observed after 11 times of reuse; (iv) reused powder showed improved flowability; and (v) reused powder showed no measurable undesired influence on the AM process and the samples exhibited highly consistent tensile properties, irrespective of their locations in the powder bed. The implications of these findings were discussed.

Deformation twins are three-dimensional domains, traditionally viewed as ellipsoids because of their two-dimensional lenticular sections. In this work, we performed statistical analysis of twin shapes viewing along three orthogonal directions: the ‘dark side’ (DS) view along the twin shear direction ( η 1 ), the twinning plane normal (TPN) view ( k 1 ) and the ‘bright side’ (BS) view along the direction λ (= k 1  ×  η 1 ). Our electron back-scatter diffraction results show that twins in the DS and BS views normally exhibit a lenticular shape, whereas they show an irregular shape in the TPN view. Moreover, the findings in the TPN view revealed that twins grow faster along λ  the lateral direction than along η 1 the forward propagation direction at the initial stages of twin growth. These twin sections are irregular, indicating that growth is locally controlled and the overall shape is not perfectly ellipsoidal. We explain these findings using atomistic models, and ascribe them to differences in the mobility of the edge and screw components of the twinning dislocations. Imaging deformation twins in three dimensions is difficult and they are usually viewed as two-dimensional ellipsoids. Here, the authors statistically analyze more than two hundred deformation twins in magnesium observed in three different views and show lateral twin expansion is faster than forward propagation.

Procalcitonin is widely reported as a useful biochemical marker to differentiate sepsis from other non-infectious causes of systemic inflammatory response syndrome. In this systematic review, we estimated the diagnostic accuracy of procalcitonin in sepsis diagnosis in critically ill patients. 18 studies were included in the review. Overall, the diagnostic performance of procalcitonin was low, with mean values of both sensitivity and specificity being 71% (95% CI 67–76) and an area under the summary receiver operator characteristic curve of 0·78 (95% CI 0·73–0·83). Studies were grouped into phase 2 studies (n=14) and phase 3 studies (n=4) by use of Sackett and Haynes' classification. Phase 2 studies had a low pooled diagnostic odds ratio of 7·79 (95% CI 5·86–10·35). Phase 3 studies showed significant heterogeneity because of variability in sample size (meta-regression coefficient −0·592, p=0·017), with diagnostic performance upwardly biased in smaller studies, but moving towards a null effect in larger studies. Procalcitonin cannot reliably differentiate sepsis from other non-infectious causes of systemic inflammatory response syndrome in critically ill adult patients. The findings from this study do not lend support to the widespread use of the procalcitonin test in critical care settings.

Employing the quantum Liouville equation with phenomenological dissipation, we investigate the transport properties of massless and massive Dirac fermion systems that mimics graphene and topological insulators, respectively. The massless Dirac fermion system does not show an intrinsic Hall effect, but it shows a Hall current under the presence of circularly-polarized laser fields as a nature of a optically-driven nonequilibrium state. Based on the microscopic analysis, we find that the light-induced Hall effect mainly originates from the imbalance of photocarrier distribution in momentum space although the emergent Floquet-Berry curvature also has a non-zero contribution. We further compute the Hall transport property of the massive Dirac fermion system with an intrinsic Hall effect in order to investigate the interplay of the intrinsic topological contribution and the extrinsic light-induced population contribution. As a result, we find that the contribution from the photocarrier population imbalance becomes significant in the strong field regime and it overcomes the intrinsic contribution. This finding clearly demonstrates that intrinsic transport properties of materials can be overwritten by external driving and may open a way to ultrafast optical-control of transport properties of materials.

The dynamic change mode of land cover not only reflects the change characteristics of the land cover itself, but also reflects the influence exerted by external factors. Empirical mode decomposition is an effective time-frequency analysis method for nonlinear and nonstationary signals. In this paper, empirical mode decomposition firstly uses to each pixel time series to get its intrinsic mode functions, each intrinsic mode function relates to change mode with some time scale, clustering those intrinsic mode functions over the image, and different land cover change modes are obtained. The experimental dataset used is MODIS subset from the Jan 2011 to Dec 2020, located in the Ningxia Hui Autonomous Region, China. The clustering results of half-annual cycle and one-year cycle of intrinsic mode functions show the influence of local climate and policy factors on land cover change.

Summary In this study, we attempt to determine the clinical characteristic and risk factors of postoperative pneumonia (POP) after hip fracture surgery in a well-defined hip fracture cohort. We find that intrinsic factors as well as major clinical interventions were all important risk factors of POP. Introduction Postoperative pneumonia (POP) is one of the major complications following hip fractures surgery. However, the risk factors of POP are not well studied in hip fracture cohorts. We attempt to determine the clinical characteristic and risk factors of POP after hip fracture surgery in a well-defined hip fracture cohort. Methods Datasets from a prospective hip fracture cohort study with a 2-year follow-up period, from 2000 to 2011, were reanalyzed for characteristics of POP. Multivariate Cox proportional regression was used to evaluate the association between the incidence of POP and all-cause mortality. Multivariate logistic regression was used to screen for potential risk factors of POP by analyzing demographic factors, comorbidities, major clinical interventions, and hematological parameters. Results In 1429 patients who underwent hip surgery, the incidence of POP was 4.9 % ( n  = 70). All-cause mortality of patients with POP was significantly higher than that of patients without POP at 30 days (hazard ratio (HR) 3.05, 95 % confidence intervals (CI) 1.88–4.94), 1 year (HR 1.87, 95 % CI 1.41–2.48), and 2 years (HR 1.57, 95 % CI 1.23–1.99) postoperatively. Multivariate logistic regression showed that intrinsic factors (advanced age, anemia, diabetes, prior stroke, number of comorbidities, ASA score ≥III, and some laboratory biomarkers) as well as major clinical interventions were all significant risk factors for POP. Conclusion Intrinsic factors and major clinical interventions were all important risk factors of POP in patients after hip fracture surgery. Targeted preventive measures to mitigate the above risk factors may help in reducing the incidence of POP.

Railroads in late nineteenth-century Japan are credited with facilitating factor mobility as well as access to human and financial capital, but their impact on firms has been unclear. Using a prefecture-level panel data set and a difference-in-differences model that exploits the temporal and spatial variation of railroad expansion, I investigate the relationship between railways and increased firm activity. Rail access led to higher average firm capitalization, particularly in manufacturing, and more populated and less accessible areas gained disproportionately more firms. By widening markets and allowing for agglomeration economies, Japanese railways promoted capital investment and more efficient resource allocation.

The Global Leadership Initiative on Malnutrition (GLIM) is new criteria for diagnosing malnutrition that need validation adjusted to race. Our aim is to determine the optimal reference values of calf circumference (CC), investigate the prevalence of GLIM-defined malnutrition based on different screening tools in inpatients over 70 years old in China and assess its relationship with clinical outcomes. We designed two continuity studies by analyzing a prospective multicenter database. First, we estimated and validated the CC cut-off values by receiver operating characteristic analyses against in-hospital mortality. Then the patients who were at risk by NRS 2002, MNA-SF and MUST were assessed by the GLIM criteria using the new CC values. Some clinical parameters and outcome data were evaluated. The optimal cut-off values of CC were 29.6 cm for male patients and 27.5 cm for female patients. The prevalence of GLIM-defined malnutrition was 27.5% by using NRS2002, 32.6% by using MNA-SF and 25.4% by using MUST. Patients with GLIM-defined malnutrition showed significantly worse values in BMI, total protein, albumin, neutrophil/lymphocyte ratio, CC, rate of complication, in-hospital mortality, length of stay, and total hospital cost than normal patients. Multivariate logistic regression showed the odds ratio of in-hospital mortality was significantly associated with GLIM defined malnutrition by using MNA-SF [OR = 1.231, 95%CI (1.022, 1.484), P = 0.029]. The Chinese reference values of CC for inpatients over 70 years old were validated by in-hospital mortality, which could be implemented in GLIM criteria. And this population possessed a high prevalence of nutrition risk and malnutrition. GLIM criteria with MNA-SF seems to be the first choice to diagnose malnutrition.

Sensory hair cells and their associated non-sensory supporting cells in the inner ear are fundamental for hearing and balance. They arise from a common progenitor 1 , but little is known about the molecular events specifying this cell lineage. We recently identified two allelic mouse mutants, light coat and circling ( Lcc ) and yellow submarine ( Ysb ), that show hearing and balance impairment 2 . Lcc / Lcc mice are completely deaf, whereas Ysb / Ysb mice are severely hearing impaired 2 . We report here that inner ears of Lcc / Lcc mice fail to establish a prosensory domain and neither hair cells nor supporting cells differentiate, resulting in a severe inner ear malformation, whereas the sensory epithelium of Ysb / Ysb mice shows abnormal development with disorganized and fewer hair cells. These phenotypes are due to the absence (in Lcc mutants) or reduced expression (in Ysb mutants) of the transcription factor SOX2, specifically within the developing inner ear. SOX2 continues to be expressed in the inner ears of mice lacking Math1 (also known as Atoh1 and HATH1 ), a gene essential for hair cell differentiation, whereas Math1 expression is absent in Lcc mutants, suggesting that Sox2 acts upstream of Math1 .

Solute and vacancy depletion have long been investigated to reveal the formation mechanism of grain boundary precipitate-free zones (GB-PFZ) during ageing, yet there is no conclusive explanation due to the simultaneous appearance of the two in GB-PFZ. In this study, the evolution of GB-PFZs and solute distributions in the vicinity of grain boundaries (GBs) were studied during the homogenisation of an Al–Cu–Mg–Mn alloy using transmission electron microscopy, high-angle annular dark field scanning transmission electron microscopy, and energy-dispersive X-ray spectroscopy. Results indicated that the evolution of GB-PFZ during homogenisation can be divided into the following three stages: Stage I, formation and recession of GB-PFZ; Stage II, absence of GB-PFZ, and Stage III, the reappearance and broadening of GB-PFZ. The results also revealed that the GB-PFZ in Stage I is totally devoid of solute depletion and its formation can be attributed to vacancy depletion alone. The GB-PFZ at Stage III solely caused by solute depletion and excludes vacancy depletion.