The emergence of bulk metallic glasses and their identification as versatile advanced engineering materials with attractive properties has led to a surge in research efforts to investigate processing ...methods, which can be used either to synthesise new BMG alloys or to shape BMG workpieces into final components with specific geometries. Among such technologies, the number of studies focussing on the laser processing of BMGs has gradually increased over the past decade. For this reason, a comprehensive summary of the state-of-the-art in this particular field of research is presented in this review. The reported studies are categorised into the different laser applications that have been proposed so far by the research community, namely the welding, cladding, additive layer manufacturing, micro machining and microstructure modification of BMG substrates. Due to the attractive properties of BMGs stemming from their amorphous nature, results are also presented, when available, concerning the effect of laser irradiation on the generation of crystalline precipitates during processing and the effect of these changes on the resulting material properties. This review has identified a number of gaps in the knowledge surrounding the laser processing of bulk metallic glasses. Understanding the fundamental interaction of laser energy with multi-component alloys will be necessary, as the development of lasers continues and the amount of available bulk metallic glasses increases. In particular, the crystallisation kinetics of bulk metallic glasses during laser irradiation needs to be understood to aid in the development and optimisation of processes such as welding and cladding. This could be helped by created an accurate simulation model to predict the onset of crystallisation although this is not a minor challenge, developing a complete temperature field model during laser irradiation is a complex task when considering vaporisation, plasma effects as well as chemical composition changes in the material. Besides, there is also the issue of variations in material properties as the temperature increases, particularly for BMGs whose temperature dependent properties are not well-documented. The research into the additive layer manufacturing of bulk metallic glass should continue to grow. Parametric effects need to be addressed to complete the optimisation of this process. Further investigations of the resulting crystallisation processes upon repeated melting and solidification should also aid in the process being able to be controlled more effectively. Finally, the use of laser processing of bulk metallic glass for specific application needs to be investigated further.
Latin Blackness in Parisian Visual Culture, 1852-1932 examines an understudied visual language used to portray Latin Americans in mid-19th to early 20th-century Parisian popular visual media. The ...term 'Latinize' is introduced to connect France's early 19th-century endeavors to create "Latin America," an expansion of the French empire into the Latin-language based Spanish and Portuguese Americas, to its perception of this population. Latin-American elites traveler to Paris in the 1840s from their newly independent nations were denigrated in representations rather than depicted as equals in a developing global economy. Darkened skin, etched onto images of Latin Americans of European descent mitigated their ability to claim the privileges of their ancestral heritage. Whitened skin, among other codes, imposed on turn-of-the-20th-century Black Latin Americans in Paris tempered their Blackness and rendered them relatively assimilatable compared to colonial Africans, Blacks from the Caribbean, and African Americans. After identifying mid-to-late 19th-century Latinizing codes, the study focuses on shifts in latinizing visuality between 1890-1933 in three case studies: the depictions of popular Cuban circus entertainer Chocolat; representations of Panamanian World Bantamweight Champion boxer Alfonso Teofilo Brown; and paintings of Black Uruguayans executed by Pedro Figari, a Uruguayan artist, during his residence in Paris between 1925-1933.
Climate simulations predict a slowing of the Atlantic meridional overturning circulation (MOC), a key oceanic component of the climate system, while continuous observations of the MOC from boundary ...arrays demonstrate substantial variability on weekly to interannual time scales. These arrays are necessarily limited to individual latitudes. A potential proxy for the MOC covering longer time scales and larger spatial scales is desirable. Here we use sea surface height data from satellites to estimate the interannual variability of transbasin ocean transports at 26°N. Combining this estimate with surface Ekman transport and cable measurements of the Florida Current, we construct a time series of the MOC from 1993 to 2014. This satellite‐based estimate recovers over 90% of the interannual variability of the MOC measured by the RAPID 26°N array. This analysis complements in situ observational efforts to measure the MOC at multiple latitudes and opens the door to a broader spatial understanding of the Atlantic circulation variability.
Key Points
Western boundary dynamic height governs interannual variability of transports
Sea level anomalies in the west anticorrelate transbasin transports at 26°N
The MOC 1993–2014 weakened (~1 Sv) due to a weakening of the Florida Current
Managing malnutrition in COPD: A review Keogh, Emma; Mark Williams, E.
Respiratory medicine,
January 2021, 2021-01-00, 20210101, Letnik:
176
Journal Article
Recenzirano
Odprti dostop
In the UK approximately 1.2 million people have COPD with around 25–40% being underweight and 35% have a severely low fat-free mass index. Measuring their body mass index is recommended and Health ...care professionals should endeavour to ensure that COPD patients are achieving their nutritional requirements.
A narrative review summarizes evidence from 28 original articles identified through a systematic searches of databases, grey literature and hand searches covering 15 years, focusing on two themes, on the impact of malnutrition on COPD, and the management of malnutrition in COPD.
Malnutrition causes negative effects on exercise and muscle function and lung function as well as increasing exacerbations, mortality and cost. Management options include nutritional supplementation which may increase weight and muscle function. Nutritional education has short-term improvements.
Malnutrition affects multiple aspects of COPD, but treatment is of benefit. Clinical practice should include nutrition management.
The Atlantic Meridional Overturning Circulation (AMOC) is responsible for a variable and climatically important northward transport of heat. Using data from an array of instruments that span the ...Atlantic at 26°N, we show that the AMOC has been in a state of reduced overturning since 2008 as compared to 2004–2008. This change of AMOC state is concurrent with other changes in the North Atlantic such as a northward shift and broadening of the Gulf Stream and altered patterns of heat content and sea surface temperature. These changes resemble the response to a declining AMOC predicted by coupled climate models. Concurrent changes in air‐sea fluxes close to the western boundary reveal that the changes in ocean heat transport and sea surface temperature have altered the pattern of ocean‐atmosphere heat exchange over the North Atlantic. These results provide strong observational evidence that the AMOC is a major factor in decadal‐scale variability of North Atlantic climate.
Key Points
New data from the RAPID 26°N array show that the AMOC has been in a state of reduced overturning since mid‐2008
Observations of heat content and SSH indicate that the impact of the reduction in the AMOC is similar to that predicted by climate models
The results indicate that changes in ocean heat transport have altered ocean‐atmosphere heat exchange over the North Atlantic
The acute respiratory distress syndrome (ARDS) is a life-threatening lung condition resulting from direct and indirect insults to the lung. It is characterized by disruption of the ...endothelial-epithelial barrier, alveolar damage, pulmonary edema, and respiratory failure. A key feature of ARDS is the accumulation of neutrophils in the lung microvasculature, interstitium, and alveolar space. Despite a clear association between neutrophil influx into the lung and disease severity, there is some debate as to whether neutrophils directly contribute to disease pathogenesis. The primary function of neutrophils is to provide immediate host defense against pathogenic microorganisms. Neutrophils release numerous antimicrobial factors such as reactive oxygen species, proteinases, and neutrophil extracellular traps. However, these factors are also toxic to host cells and can result in bystander tissue damage. The excessive accumulation of neutrophils in ARDS may therefore contribute to disease progression. Central to neutrophil recruitment is the release of chemokines, including the archetypal neutrophil chemoattractant IL-8, from resident pulmonary cells. However, the chemokine network in the inflamed lung is complex and may involve several other chemokines, including CXCL10, CCL2, and CCL7. This review will therefore focus on the experimental and clinical evidence supporting neutrophils as key players in ARDS and the chemokines involved in recruiting them into the lung.
Ciliogenesis precedes lineage-determining signaling in skin development. To understand why, we performed shRNA-mediated knockdown of seven intraflagellar transport proteins (IFTs) and conditional ...ablation of
Ift-88 and
Kif3a during embryogenesis. In both cultured keratinocytes and embryonic epidermis, all of these eliminated cilia, and many (not
Kif3a) caused hyperproliferation. Surprisingly and independent of proliferation, ciliary mutants displayed defects in Notch signaling and commitment of progenitors to differentiate. Notch receptors and Notch-processing enzymes colocalized with cilia in wild-type epidermal cells. Moreover, differentiation defects in ciliary mutants were cell autonomous and rescued by activated Notch (NICD). By contrast, Shh signaling was neither operative nor required for epidermal ciliogenesis, Notch signaling, or differentiation. Rather, Shh signaling defects in ciliary mutants occurred later, arresting hair follicle morphogenesis in the skin. These findings unveil temporally and spatially distinct functions for primary cilia at the nexus of signaling, proliferation, and differentiation.
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► Ciliogenesis precedes lineage-determining signaling during skin development ► Embryonic epidermal progenitors lacking cilia show early defects in differentiation ► Notch signaling is inhibited in ciliary mutants in a cell-autonomous fashion ► Notch components localize to the basal body and cilia in developing epidermis
Background Studies suggest an association between acute kidney injury (AKI) and long-term risk for chronic kidney disease (CKD), even following apparent renal recovery. Whether the pattern of renal ...recovery predicts kidney risk following AKI is unknown. Study Design Retrospective cohort. Setting & Participants Patients in the Veterans Health Administration in 2011 hospitalized (>24 hours) with at least 2 inpatient serum creatinine measurements, baseline estimated glomerular filtration rate > 60 mL/min/1.73 m2 , and no diagnosis of end-stage renal disease or non−dialysis-dependent CKD: 17,049 (16.3%) with and 87,715 without AKI. Predictor Pattern of recovery to creatinine level within 0.3 mg/dL of baseline after AKI: within 2 days (fast), in 3 to 10 days (intermediate), and no recovery by 10 days (slow or unknown). Outcome CKD stage 3 or higher, defined as 2 outpatient estimated glomerular filtration rates < 60 mL/min/1.73 m2 at least 90 days apart or CKD diagnosis, dialysis therapy, or transplantation. Measurements Risk for CKD was modeled using modified Poisson regression and time to death-censored CKD was modeled using Cox proportional hazards regression, both stratified by AKI stage. Results Most patients’ AKI episodes were stage 1 (91%) and 71% recovered within 2 days. At 1 year, 18.2% had developed CKD (AKI, 31.8%; non-AKI, 15.5%; P < 0.001). In stage 1, the adjusted relative risk ratios for CKD stage 3 or higher were 1.43 (95% CI, 1.39-1.48), 2.00 (95% CI, 1.88-2.12), and 2.65 (95% CI, 2.51-2.80) for fast, intermediate, and slow/unknown recovery. A similar pattern was observed in subgroup analyses incorporating albuminuria and sensitivity analysis of death-censored time to CKD. Limitations Variable timing of follow-up and mostly male veteran cohort may limit generalizability. Conclusions Patients who develop AKI during a hospitalization are at substantial risk for the development of CKD by 1 year following hospitalization and timing of AKI recovery is a strong predictor, even for the mildest forms of AKI.
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