Long-term stabilized amorphous calcium carbonate-an ink for bio-inspired 3D printing.

Biominerals formed by organisms in the course of biomineralization often demonstrate complex morphologies despite their single-crystalline nature. This is achieved owing to the crystallization via a predeposited amorphous calcium carbonate (ACC) phase, a precursor that is particularly widespread in biominerals. Inspired by this natural strategy, we used robocasting, an additive manufacturing three-dimensional (3D) printing technique, for printing 3D objects from novel long-term, Mg-stabilized ACC pastes with high solids loading. We demonstrated, for the first time, that the ACC remains stable for at least a couple of months, even after printing. Crystallization, if desired, occurs only after the 3D object is already formed and at temperatures significantly lower than those of common postprinting sintering. We also examined the effects different organic binders have on the crystallization, the morphology, and the final amount of incorporated Mg. This novel bio-inspired method may pave the way for a new bio-inspired route to low-temperature 3D printing of ceramic materials for a multitude of applications.

Comparison of clinical outcomes of influenza A and B at the 2017-2018 influenza season: a cohort study.

Influenza has significant morbidity and mortality. Some experts consider infection with influenza B as milder than that with influenza A. The objective of this study is to evaluate the outcomes of hospitalized patients with laboratory-confirmed influenza A or B in 2017-2018 influenza season. All hospitalized patients between October 2017 and April 2018 with laboratory-confirmed influenza A and B were included. The primary composite outcomes were pneumonia/myocarditis/encephalitis, mechanical ventilation, ICU admission, and 30-day mortality. Secondary outcomes were 30-/90-day mortality, length of hospital stay, and readmission rates. The study included 201 influenza A and 325 influenza B. For the primary composite outcome, no significant difference was demonstrated between influenza A and B. Rates of mortality were similar at 30 and 90 days. Influenza A had higher pneumonia rates and mechanical ventilation. On multivariate analysis, higher Charlson's score, hypoalbuminemia, and vasopressor use were associated with 30-day mortality, while infection with either influenza A or B was not. Influenza A was associated with higher pneumonia and mechanical ventilation rates. However, influenza B resulted with similar 30-day mortality rate as influenza A.

Risk factors for long-term mortality of Staphylococcus aureus bacteremia.

Staphylococcus aureus bacteremia (SAB) is a fatal disease. We aimed to describe risk factors for long-term mortality with SAB. We analyzed data from a retrospectively collected database including 1,692 patients with SAB. We considered variables of infection and background conditions for the analysis of long-term survival. The Kaplan-Meier procedure was used for analysis of long-term survival. Variables significantly associated with mortality were analyzed using a Cox regression model. We included 1,692 patients in the analysis. Patients were followed for up to 22 years. Within one year, 62% of patients died and within 5 years 72% died. A total of 82% of patients aged 65 years and older died within 5 years. Independent predictors of long-term mortality were older age (Hazard ratio 1.029, 95% confidence interval 1.022-1.036), female gender (HR 1.302, 95% CI 1.118-1.517), pneumonia or primary/ unknown source of infection (HR 1.441, 95% CI 1.230-1.689), dementia (HR 1.234, 95% CI 1.004-1.516), higher Charlson score (HR 1.155, 95% CI 1.115-1.196), shock at onset (HR 1.776, 95% CI 1.430-2.207) and arrival to hospitalization from an institution (HR 1.319, 95% CI 1.095-1.563). Long-term survival of patients older than 65 years and of women with SAB is severely curtailed.

Monomicrobial necrotizing fasciitis in a single center: the emergence of Gram-negative bacteria as a common pathogen.

BACKGROUND: Necrotizing fasciitis (NF) is a life-threatening soft tissue infection. It is usually caused by Streptococcus pyogenes and other Gram-positive bacteria. Several reports, however, emphasize the importance of Gram-negative rods in this infection. METHODS: We retrospectively studied all cases of monomicrobial necrotizing fasciitis hospitalized in our center during the years 2002-2012. We compared clinical characteristics and outcomes of patients with Gram-negative versus Gram-positive infection. RESULTS: Forty-five cases were reviewed, 19 caused by Gram-negative organisms, 10 of them Escherichia coli, and 26 caused by Gram-positive organisms, 10 of them S. pyogenes. Compared to Gram-positive infections, patients with Gram-negative infections were more likely to have a baseline malignancy (9/19, 47.4%) or to have undergone recent surgery (4/19, 42.3%). The 30-day mortality was higher among Gram-negative infected patients (8/19, 42.1% vs. 8/26, 30.8%). Creatine phosphokinase (CPK) was elevated in a minority of patients with Gram-negative necrotizing fasciitis, and its absolute value was lower than in Gram-positive necrotizing fasciitis. CONCLUSIONS: In our center, 42% of monomicrobial necrotizing fasciitis cases were found to be caused by Gram-negative organisms, mostly E. coli. These infections usually appeared in immunocompromised or postoperative patients, often presented with normal CPK levels, and were associated with high mortality rates.

Antiferromagnetic Ordering of Magnetic Clusters Units in Nb(6)F(15).

We have studied the magnetic cluster compound Nb(6)F(15) which has an odd number of 15 valence electrons per (Nb(6)F(12))(3+) cluster core, as a function of temperature using nuclear magnetic resonance, magnetic susceptibility, electron magnetic resonance and neutron powder diffraction. Nuclear magnetic resonance of the (19)F nuclei shows two lines corresponding to the apical F(a-a) nucleus, and to the inner F(i) nuclei. The temperature dependence of the signal from the F(i) nuclei reveals an antiferromagnetic ordering at T < 5 K, with a hyperfine field of ~2 mT. Magnetic susceptibility exhibits a Curie-Weiss behavior with T(N) ~5 K, and µ(eff) ~1.57 µ(B) close to the expected theoretical value for one unpaired electron (1.73 µ(B)). Electron magnetic resonance linewidth shows a transition at 5 K. Upon cooling from 10 to 1.4 K, the neutron diffraction shows a decrease in the intensity of the low-angle diffuse scattering below Q ~0.27 Å(-1). This decrease is consistent with emergence of magnetic order of large magnetic objects (clusters). This study shows that Nb(6)F(15) is paramagnetic at RT and undergoes a transition to antiferromagnetic order at 5 K. This unique antiferromagnetic ordering results from the interaction between magnetic spins delocalized over each entire (Nb(6)F(12) (i))(3+) cluster core, rather than the common magnetic ordering.

Sequence elimination and cytosine methylation are rapid and reproducible responses of the genome to wide hybridization and allopolyploidy in wheat.

Interspecific or intergeneric hybridization, followed by chromosome doubling, can lead to the formation of new allopolyploid species. Recent studies indicate that allopolyploid formation is associated with genetic and epigenetic changes, although little is known about the type of changes that occur, how rapidly they occur, and the type of sequences involved. To address these matters, we have surveyed F1 hybrids between diploid species from the wheat (Aegilops and Triticum) group and their derived allotetraploids by screening a large number of loci using amplified fragment length polymorphism and DNA gel blot analysis and by assaying the extent of cytosine methylation. We found that sequence elimination is one of the major and immediate responses of the wheat genome to wide hybridization or allopolyploidy, that it affects a large fraction of the genome, and that it is reproducible. In one cross between AE: sharonensis x AE: umbellulata, 14% of the loci from AE: sharonensis were eliminated compared with only 0.5% from AE: umbellulata, with most changes occurring in the F1 hybrid. In contrast, crosses between AE: longissima x T. urartu showed that sequence elimination was more frequent after chromosome doubling. Alterations in cytosine methylation occurred in approximately 13% of the loci, either in the F1 hybrid or in the allopolyploid. For eight of nine bands that were isolated, the sequences that underwent elimination corresponded to low-copy DNA, whereas alterations in methylation patterns affected both repetitive DNA sequences, such as retrotransposons, and low-copy DNA in approximately equal proportions.

Selective inhibition of platelet macroaggregate formation by a recombinant heparin-binding domain of human thrombospondin.

Thrombospondin (TSP) is a platelet alpha-granule adhesive protein that plays a critical role in the stabilization of thrombus by promoting the formation of platelet macroaggregates. We have recently shown that a monoclonal antibody (mAb) to the NH2-terminal heparin-binding domain of TSP, MAII, inhibits platelet aggregation induced by thrombin in a dose-dependent manner. In this study, we have expressed in Escherichia coli two recombinant proteins comprising residues 1 to 174 (TSP18) and 1 to 242 (TSP28) of TSP. After purification, both proteins reacted equally well with mAb MAII, whereas the reactivity of TSP18 for heparin was lower than that of TSP28 or native TSP. At micromolar concentrations, TSP18 and TSP28 inhibited the second wave of platelet aggregation and the concomitant release of [14C]5-hydroxytryptamine induced by ADP in citrated platelet-rich plasma as well as aggregation and secretion induced by a low concentration of thrombin in washed platelet suspensions. The proteins did not inhibit surface expression of endogenous TSP on activated platelets, as measured by the binding of radiolabeled mAb 5G11, indicating that they did not interfere with the primary binding of TSP to the plasma membrane. In contrast, in a solid-phase binding assay, the proteins inhibited in a dose-dependent manner (IC50, 0.1 and 0.06 mumol/L for TSP18 and TSP28, respectively) the binding of radiolabeled TSP to surface-adsorbed fibrinogen. Furthermore, specific and saturable binding of the proteins to immobilized fibrinogen was demonstrated by enzyme-linked immunosorbent assay. The results suggest that interaction between the heparin-binding domain of TSP and membrane-bound fibrinogen may be critical in the platelet aggregation/secretion process.