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2D transition metal dichalcogenides (TMDs) for advanced logic transistor technologies are deposited by various modifications of the chemical vapor deposition (CVD) method using a wide variety of precursors. Being a major electrical performance limiter, the TMD crystal grain size strongly differs between the various CVD precursor chemistries from nano‐ to millimeter‐sized crystals. However, it remains unclear how the CVD precursor chemistry affects the nucleation density and resulting TMD crystal grain size. This work postulates guiding principles to design a CVD process for highly crystalline TMD deposition using a quantitative analytical model benchmarked against the literature. The TMD nucleation density reduces favorably under low supersaturation conditions where the metal precursor sorption on the starting surface is reversible and the corresponding metal precursor desorption rate exceeds the overall deposition rate. Such reversible precursor adsorption guarantees efficient long‐range gas‐phase lateral diffusion of precursor species in addition to short‐range surface diffusion, which vitally increases crystal grain size. The proposed model explains the large spread in experimentally observed TMD nucleation densities and crystal grain sizes for state‐of‐the‐art CVD chemistries. Ultimately, it empowers the reader to interpret and modulate precursor adsorption and diffusion reactions through designing CVD precursor chemistries. [ABSTRACT FROM AUTHOR]

Background: Anti‐K is an alloantibody stimulated in response to the KEL1 antigen and may cause hemolytic disease of the fetus and newborn (HDFN). Provision of KEL1 negative blood to females of child‐bearing potential was not our practice. We assessed the impact of our policy and assessed feasibility of a KEL1 negative transfusion policy. Study design and methods: This is a cohort study spanning Jan 1, 2007–Jun 30, 2017 in Hamilton, Canada. Data were obtained via our institution's transfusion database. Chart reviews of females age ≤45 with anti‐K were performed; data on RBC KEL1 phenotype were obtained from the blood supplier when needed to ascertain the cause of alloimmunization. Descriptive analysis of hospital KEL1 negative inventory demand and supply was performed. Results: From Jan 2007‐Jun 2017, 8.6% of all RBC units transfused were provided to females age ≤45. There were 111 females with detectable anti‐K. Median age at time of antibody detection was 34 years (interquartile range 27–40) and 28 of 111 (25.2%) patients may have been alloimmunized by transfusion. Of 49 pregnancies, seven had complications due to anti‐K. We estimated that our existing RBC inventory (with 16% units known to be KEL1 negative in 2017) is sufficient to meet demand and support a KEL1 negative transfusion policy for females age ≤45. Conclusion: Transfusion was responsible for alloimmunization in 25% of females with anti‐K over 10 years. Analysis of supply and demand can be used to inform feasibility of a KEL1 negative transfusion policy. [ABSTRACT FROM AUTHOR]

Background and Objectives Materials and Methods Results Conclusion Postpartum anaemia is a prevalent health problem. We aimed to determine the compliance rate for red blood cell (RBC) transfusion indication among postpartum women in a single tertiary care centre in Quebec, Canada.Retrospective cohort study including all women ≥6 h postpartum who received ≥1 RBC transfusion during their delivery hospitalization between January 2005 and February 2022. We determined our centre's compliance rate by indication as compared to current society guidelines, all published after 2015 (Network for the Advancement of Patient Blood Management, Haemostasis and Thrombosis [NATA], Royal College of Obstetricians and Gynaecologists [RCOG], American College of Obstetricians and Gynecologists [ACOG]). We then explored predictors of guideline non‐compliance and described transfusion practices in our centre.A total of 171 women were included. Our centre's compliance rate was 79.5% (95% confidence interval [CI] 72.7–84.8). Predictors of guideline non‐compliance were maternal medical comorbidity or abnormal placentation, both limited by large CIs (odds ratio [OR] 2.26, CI 1.02–4.94, p = 0.04; OR 4.00, CI 1.31–12.06, p = 0.01, respectively). Postpartum haemorrhage was diagnosed among 68% of the cohort, mostly due to uterine atony (73.3%). Mean baseline and nadir haemoglobin were 111 g/L (±18) and 62 g/L (±7.7), respectively. Multiple unit initial transfusion was found in a majority of patients (63.7%). Iron therapy was administered to 51.5% of women in‐hospital and 81.9% received an oral iron prescription at discharge. There were no differences in primary or secondary outcomes subsequent to relevant guideline publication.Our centre's compliance rate for RBC transfusion indication meets current practice guidelines. Areas for improvement include single‐unit initial transfusion protocols and adjuvant iron treatment. Antenatal optimization of haemoglobin and ferritin stores may limit postpartum transfusions. [ABSTRACT FROM AUTHOR]

Recently, a step-flow growth mode has been proposed to break the inherent molybdenum disulfide (MoS 2 ) crystal domain bimodality and yield a single-crystalline MoS 2 monolayer on commonly employed sapphire substrates. This work reveals an alternative growth mechanism during the metal-organic chemical vapor deposition (MOCVD) of a single-crystalline MoS 2 monolayer through anisotropic 2D crystal growth. During early growth stages, the epitaxial symmetry and commensurability of sapphire terraces rather than the sapphire step inclination ultimately govern the MoS 2 crystal orientation. Strikingly, as the MoS 2 crystals continue to grow laterally, the sapphire steps transform the MoS 2 crystal geometry into diamond-shaped domains presumably by anisotropic diffusion of ad-species and facet development. Even though these MoS 2 domains nucleate on sapphire with predominantly bimodal 0 and 60° azimuthal rotation, the individual domains reach lateral dimensions of up to 200 nm before merging seamlessly into a single-crystalline MoS 2 monolayer upon coalescence. Plan-view transmission electron microscopy reveals the single-crystalline nature across 50 μm by 50 μm inspection areas. As a result, the median carrier mobility of MoS 2 monolayers peaks at 25 cm 2 V -1 s -1 with the highest value reaching 28 cm 2 V -1 s -1 . This work details synthesis-structure correlations and the possibilities to tune the structure and material properties through substrate topography toward various applications in nanoelectronics, catalysis, and nanotechnology. Moreover, shape modulation through anisotropic growth phenomena on stepped surfaces can provide opportunities for nanopatterning for a wide range of materials.