Facile synthesis of ZnO nanobullets by solution plasma without chemical additives

ZnO nano-bullets were synthesized using solution plasma from only Zn electrode in water without any chemical agents. In this sustainable synthesis system, the rapid quenching reaction at the interface between the plasma/liquid phases facilitates the fast formation of nano-sized materials. The coil-to-pin type electrode geometry, which overcomes the discharge interruption owing to the electrode gap broadening of the typical pin-to-pin type enables the synthesis of numerous nanomaterials through a stable discharge for 1 h. The as-prepared samples exhibited a high crystalline ZnO structure without post calcination, and the length and width were 71.8 and 29.1 nm, respectively. The main exposed facet of ZnO nano-bullets was the (100) crystal facet, but interestingly, the (101) facet was confirmed at the inclined surfaces in the edges. The (101) crystal facet has an asymmetric Zn and O atom arrangement, and it could result in a focused electron density area with relatively high reactivity. Therefore, ZnO nano-bullets are promising materials for applications in advanced technologies.

ZnO nano-bullets were synthesized using only Zn electrode and water by solution plasma and new electrode geometry improved discharge time up to 1 h.     

Selective CO2 adsorption and bathochromic shift in a phosphocholine-based lipid and conjugated polymer assembly

We assemble a film of a phosphocholine-based lipid and a crystalline conjugated polymer using hydrophobic interactions between the alkyl tails of the lipid and alkyl side chains of the polymer, and demonstrated its selective gas adsorption properties and the polymer''s improved light absorption properties. We show that a strong attractive interaction between the polar lipid heads and CO₂ was responsible for 6 times more CO₂ being adsorbed onto the assembly than N₂, and that with repeated CO₂ adsorption and vacuuming procedures, the assembly structures of the lipid-polymer assembly were irreversibly changed, as demonstrated by in situ grazing-incidence X-ray diffraction during the gas adsorption and desorption. Despite the disruption of the lipid structure caused by adsorbed polar gas molecules on polar head groups, gas adsorption could promote orderly alkyl chain packing by inducing compressive strain, resulting in enhanced electron delocalization of conjugated backbones and bathochromic light absorption. The findings suggest that merging the structures of the crystalline functional polymer and lipid bilayer is a viable option for solar energy-converting systems that use conjugated polymers as a light harvester and the polar heads as CO₂-capturing sites.

Assembly films of a phosphocholine-based lipid and a crystalline conjugated polymer had significant CO₂ selective adsorption and light absorption due to the attractive interaction of CO₂ with exposed polar lipid heads and enhanced morphologies.     

Comparative Evaluation of Rapid Isothermal Amplification and Antigen Assays for Screening Testing of SARS-CoV-2

Human transmission of SARS-CoV-2 and emergent variants of concern continue to occur globally, despite mass vaccination campaigns. Public health strategies to reduce virus spread should therefore rely, in part, on frequent screening with rapid, inexpensive, and sensitive tests. We evaluated two digitally integrated rapid tests and assessed their performance using stored nasal swab specimens collected from individuals with or without COVID-19. An isothermal amplification assay combined with a lateral flow test had a limit of detection of 10 RNA copies per reaction, and a positive percent agreement (PPA)/negative percent agreement (NPA) during the asymptomatic and symptomatic phases of 100%/100% and 95.83/100%, respectively. Comparatively, an antigen-based lateral flow test had a limit of detection of 30,000 copies and a PPA/NPA during the asymptomatic and symptomatic phases of 82.86%/98.68% and 91.67/100%, respectively. Both the isothermal amplification and antigen-based lateral flow tests had optimized detection of SARS-CoV-2 during the peak period of transmission; however, the antigen-based test had reduced sensitivity in clinical samples with qPCR Ct values greater than 29.8. Low-cost, high-throughput screening enabled by isothermal amplification or antigen-based techniques have value for outbreak control.     

In vitro evaluation of the susceptibility of endodontic pathogens to calcium hydroxide combined with different vehicles

The aim of this study was to investigate in vitro the antimicrobial activity of calcium hydroxide [Ca(OH)2] in combination with different vehicles against endodontic pathogens. For such purpose, a broth dilution test was performed. Pastes were prepared with Ca(OH)2 powder and the following vehicles: sterile water, glycerin, camphorated monochlorophenol (CMCP), CMCP + glycerin, polyethyleneglycol and CMCP + polyethyleneglycol. The time required for the pastes to produce negative cultures against the tested microorganisms was recorded and analyzed statistically using the Kruskal Wallis test at 5% significance level. Timing for pastes to eliminate the aerobic and facultative anaerobic microorganisms ranged from 6 to 24 h, while strict anaerobic microorganisms were inhibited within 30 s to 5 min. Microbial susceptibility, ranked from weakest to strongest, can be presented as follows: Enterococcus faecalis (the most resistant microorganism), Candida albicans, Staphylococcus aureus, Porphyromonas gingivalis, Porphyromonas endodontalis and Prevotella intermedia (the last two microorganisms required the same time to be eliminated). In conclusion, calcium hydroxide pastes needed more time to eliminate facultative than anaereobic microorganisms. These findings suggest that the antimicrobial property is related both to paste formulation and to microbial susceptibility.     

Long-term clinical and histological outcomes in patients with spontaneous hepatitis B surface antigen seroclearance

BACKGROUND/AIMS: During the natural course of hepatitis B virus (HBV) infection, the long-term clinical and histological outcomes following spontaneous hepatitis B surface antigen (HBsAg) seroclearance remain unclear. METHODS: Between 1984 and 2003, 49 (9.5%) out of 432 inactive HBsAg carriers had no detectable level of circulating HBsAg. Fifteen of 49 patients had undergone paired peritoneoscopic liver biopsies. RESULTS: During a mean follow-up period of 19.6 months after HBsAg seroclearance, 5 of 49 (10.2%) patients were noted to have HCC. Liver cirrhosis (P=0.040), a history of perinatal infection (P=0.005) and long-standing duration (at least 30 years) of HBsAg positivity (P=0.002) were associated with a significantly higher risk of developing HCC. Despite HBsAg seroclearance, HBV DNA was detected in the liver tissues from all 15 patients who underwent paired liver biopsies. Necroinflammation was significantly ameliorated (P<0.0001). On the other hand, amelioration of the fibrosis score did not reach a statistically significant level (P=0.072). Interestingly, aggravation of liver fibrosis was evident in 2 patients (13.3%) including one who had rapidly progressed to overt cirrhosis. CONCLUSIONS: In patients with spontaneous HBsAg seroclearance, necroinflammation was markedly improved and liver fibrosis was unchanged or regressed despite occult HBV infection. However, HCC developed in a minority of cases.     

Pilot study on combination of azacitidine and low-dose cytarabine for patients with refractory anemia with excess blast

This study analyzed the outcomes of the combination of azacitidine and low-dose cytarabine in patients newly diagnosed with refractory anemia with excess blast (RAEB). Patients were treated with azacitidine 75 mg/m² for 7 days subcutaneously and cytarabine 20 mg/m² intravenously for 7 days every 28 days. The assigned regimen was repeated for two cycles, then the patients treated with azacytidine alone until progression or allogeneic stem cell transplantation (allo-SCT). Eighteen patients with 5 RAEB-1 and 13 RAEB-2 were enrolled in the current study. After two cycles of the combination therapy, responses were achieved in nine patients (50.0%): four complete response (CR) (22.2%), one partial response (5.6%), two marrow-CR (11.1%), and two hematologic improvement (11.1%). Four patients (22.2%) progressed to acute leukemia during two cycles of the combination therapy. The 1-year overall survival (OS) was 87.5% for the early response group (responses at two cycles) and 0% for the late response group (responses at four cycles, p = 0.042). Plus, the median survival time was 476 days (range, 37–718 days) for the early response group and 221 days (range, 193–249 days) for the late response group. The 1-year OS was 100% for the patients who underwent allo-SCT and 73.4% for those without allo-SCT. In summary, the combination therapy showed promising response rate when compared to treatment with azacitidine alone. However, it was limited in terms of preventing leukemic transformation. Allo-SCT would seem to be the only available treatment that can alter disease progression.