To improve oxidation resistance of the titanium matrix composites, the network structured Ti-Al-Si coating was successfully prepared on TiBw/Ti6Al4V composites with network microstructure utilizing ...hot dip siliconizing and subsequent heat treatment. The cycle oxidation tests showed that the weight gains of the Ti-Al-Si coating were only 8.98%, 5.99% and 3.65% of the TiBw/Ti6Al4V composites at 973K, 1073K and 1173K for 100 h. This result indicates super oxidation resistance of the network structured Ti-Al-Si of TiBw/Ti6Al4V composites, which can be ascribed to the three reasons: (1) the continuous Al2O3 oxide scale was formed in the outermost layer, (2) there were no cracks existed in the oxidized coating due to the unique network structure of the coating, (3) the Ti5Si4 layer in the interface could effectively retard the interfacial reaction between the Ti(Al,Si)3 coating and composite substrate.
Display omitted
•The Ti-Al-Si coating remarkably improve the oxidation resistance of the TiBw/Ti6Al4V composites.•The inherited network structure of the coating can effectively avoid cracks appearing in the oxidized coating.•The Ti5Si4 layer could retard the interfacial reaction between the Ti(Al,Si)3 coating and composite substrate.
Crystalline Pd/Pd-Ag membranes are widely used for hydrogen separation from CO
and other gases in power generation applications. To substitute these high cost noble metal alloy membranes, the ...Ni-Nb-Zr amorphous alloys are being developed that exhibit relatively high permeability of hydrogen between 200-400 °C. Atom probe tomography (APT) experiments performed on these ribbons revealed nm-scale Nb-rich and Zr-rich regions (clusters) embedded in a ternary matrix, indicating phase separation within the Ni-Nb-Zr amorphous alloy. Density functional theory (DFT) simulations have predicted that these clusters are composed of icosahedral coordination polyhedra. The interatomic distances and correlation lengths of the short range order of these alloys were determined by neutron total scattering which match well with our DFT based molecular dynamics (DFT-MD) simulations.
Leukemia is the most common cancer of childhood, with AML, CML, ALL and CLL being the most common. Environmental and genetic factors have been studied extensively in children with childhood leukemia. ...Other factors, such as the prenatal parental use of controlled substances, have not been investigated to the same degree. We review what is currently known about environmental and parental factors and the occurrence of leukemia in children.
Electronic databases were searched for studies correlated pediatric leukemia with (1) ionizing radiation; (2) benzene; (3) parental drug use (4) parental alcohol use; (5) genetic factors.
The two known significant environment risk factors for the occurrence leukemia are ionizing radiation and benzene. However, at least 4 studies have been published over the last century have looked at other environmental factors such as pesticides and drug and alcohol use as well as genetic factors such as gene fusions and translocations.
We determined the risk of environmental and genetic factors that could be the cause of childhood leukemia in an effort to reduce the incidence of this disease.
Background and Objectives In China, paid donation is prohibited by law. There is little literature assessing donor motivation in China, and comparison with western countries such as Canada is ...important in understanding the application of Western literature. We compared motivational factors in donors from the city of Xi’an, China, with Canadian donors matched for age, sex and donation status.
Materials and Methods A total of 218 donors in Xi’an completed an interview about motivation as did 218 Canadian donors matched for age, sex and donation status. Frequencies and percentages of responses to questions were tabulated and compared using the Chi‐squared test.
Results Donors in Xi’an and Canada felt a personal responsibility to donate blood (81·2% vs. 78·0%, P = 0·2057), but Xi’an donors were more likely to consider blood donation a social responsibility (81·7% vs. 45·2%, P < 0·0001). Xi’an donors more often believed that society views donation as a normal activity (98·6% vs. 48·4%, P < 0·0001) and that the social atmosphere promotes donation (90·3% vs. 53·5%, P < 0·0001) and saw greater health benefit (52·3% vs. 12·5%, P < 0·0001). Most Xi’an donors believed in balance between their life force (Qi) and blood (86·7% vs. 49·8%, P < 0·0001) but did not believe blood lost from donating would affect this (0·5% vs. 3·8%, P = 0·01).
Conclusion While traditional Chinese beliefs may not be seen as a barrier among people in Xi’an who donate blood, blood donation is seen differently than by Canadian donors. There is a need for more research specific to China to tailor recruitment strategies.
Iron metal anode satisfies the safety, low-cost, non-toxicity, and energy-dense pursuits chasing by the battery community, but passivation, parasitic hydrogen evolution reaction, and low plating ...efficiency challenging its electrochemical performance limit its continuous practical applications. Here, the redox behaviors of the iron metal anode in both alkaline and acidic electrolytes have been summarized first to shape the fundamental mechanisms. Recent progress in developing high-performance iron metal anodes has been introduced with the highlights on representative strategies, including electrode additives, electrolyte modification, and nanoarchitecture. Especially, the history of aqueous battery systems with iron metal anode is overviewed from its earliest beginning to the new era, following by the discussion regarding the specialization of each system. We believe this review could bring the fundament of redox behavior for optimizing the iron metal anode and pave a way toward a reliable iron-based aqueous battery.
Display omitted
Carbapenem-resistant Acinetobacter baumannii (CRAb) is 1 of the most problematic antimicrobial-resistant bacteria. We sought to elucidate the international epidemiology and clinical impact of CRAb.
...In a prospective observational cohort study, 842 hospitalized patients with a clinical CRAb culture were enrolled at 46 hospitals in five global regions between 2017 and 2019. The primary outcome was all-cause mortality at 30 days from the index culture. The strains underwent whole-genome analysis.
Of 842 cases, 536 (64%) represented infection. By 30 days, 128 (24%) of the infected patients died, ranging from 1 (6%) of 18 in Australia-Singapore to 54 (25%) of 216 in the United States and 24 (49%) of 49 in South-Central America, whereas 42 (14%) of non-infected patients died. Bacteremia was associated with a higher risk of death compared with other types of infection (40 42% of 96 vs 88 20% of 440). In a multivariable logistic regression analysis, bloodstream infection and higher age-adjusted Charlson comorbidity index were independently associated with 30-day mortality. Clonal group 2 (CG2) strains predominated except in South-Central America, ranging from 216 (59%) of 369 in the United States to 282 (97%) of 291 in China. Acquired carbapenemase genes were carried by 769 (91%) of the 842 isolates. CG2 strains were significantly associated with higher levels of meropenem resistance, yet non-CG2 cases were over-represented among the deaths compared with CG2 cases.
CRAb infection types and clinical outcomes differed significantly across regions. Although CG2 strains remained predominant, non-CG2 strains were associated with higher mortality. Clinical Trials Registration. NCT03646227.
Over-expression of the epidermal growth factor receptor (EGFR) protein, along with gene amplification, is closely associated with recurrent cervical cancer and the disease's advanced stages. ...Additionally, it can have a direct impact on the disease's prognosis. The following are the members of the HER family: (i) EGFR/HER1; (ii) HER2; (iii) HER3; and (iv) HER4. Figure 1 shows its signalling pathway. The synergy between the members facilitates immune escape by tumour cells, which can lead to tolerance to HER inhibitors. A broad HER inhibitor, a pan-HER inhibitor, can irreversibly inhibit a cell membrane's HER receptors to their ligands, thereby blocking downstream signal-transduction cascades, inhibiting tumour growth, adhesion, invasion, differentiation, and metastasis. As such, pan-HER inhibitors may be an area of interest in treating recurrent or late-stage cervical cancer.
Through a review of HER-family receptors and their molecular mechanism, we can conclude that pan-HER inhibitors do indeed have a positive impact on therapy for recurrent or late-stage cervical cancer patients.
This paper reviews the molecular mechanism that underlies receptors within the HER family, current developments in HER inhibitors, and the potential clinical impacts of pan-HER inhibitors in treating recurrent or late-stage cervical cancer.
Pan-HER inhibitors have been shown to improve prognoses for recurrent or late-stage cervical cancer patients. Preclinical studies show promising results, as well as the potential to improve results for recurrent or late-stage cervical cancer patients. Pan-HER inhibitors have also shown synergistic results in clinical and pre-clinical settings when combined with chemotherapy. However, long-term study is required regarding the combination of pan-HER inhibitors with radiotherapy and other targeted inhibitors. The question of whether or not these inhibitors have a more potent effect across the blood-brain barrier when compared to single HER-targeting agents may be an area of interest for future research. This idea will be explored in clinical cervical cancer trials.
The Ti-Al-Si coatings were prepared on TiBw/Ti6Al4V composites by a two-step method comprising hot dip and heat treatment processes to enhance the hot corrosion resistance. Results show that ...Ti-Al-3Si (wt%) and Ti-Al-20Si (wt%) coatings were mainly composed of the Ti(Al,Si)3 and Ti3AlSi5 phase, respectively. Both of the coatings can protect the substrate against the deposited NaCl, 25 wt%NaCl+ 75 wt%Na2SO4, and Na2SO4 salts. In particular, the coatings exhibited superior hot corrosion resistance in the deposited Na2SO4 salts, which is attributed to the formation of dense and continuous Al2O3 oxide scales and the slow dissolution process of sulfate during the hot corrosion process. Moreover, the Ti-Al-Si coatings exhibited serious external oxidation when hot corroded in the deposited 25 wt% NaCl+ 75 wt%Na2SO4 and Na2SO4 salts, in which more corrosion products and pores were formed due to the autocatalytic reaction processes. Since the deposited NaCl salt would rapidly dissolve the oxide scale and destroy its compactness and continuity, which presented a more serious hot corrosion effect.
•Ti-Al-Si coatings were prepared on TiBw/Ti6Al4V substrate by hot dip and heat treatment.•The coatings exhibited superior hot corrosion resistance against NaCl and Na2SO4 salts.•Formation of dense and continuous Al2O3 scales and slow dissolution of sulfate enhanced corrosion resistance.
In the United States, vanB-mediated resistance in enterococci is rare. We characterized three sequence type (ST) 6, vancomycin-resistant Enterococcus faecalis isolates causing bacteremia in unique ...patients in spatiotemporally distinct settings. Isolates were recovered between 2018 and 2020 in two cities in the United States (Houston, TX; Miami, FL). The isolates harbored the vanB operon on a chromosomally located Tn1549 transposon, and epidemiological data suggested multiple introductions of the vanB gene cluster into ST6 E. faecalis.
PDF
