A New Method of Synthesizing Black Birnessite Nanoparticles: From Brown to Black Birnessite with Nanostructures

A new method for preparing black birnessite nanoparticles is introduced. The initial synthesis process resembles the classical McKenzie method of preparing brown birnessite except for slower cooling and closing the system from the ambient air. Subsequent process, including wet-aging at 7◦C for 48 hours, overnight freezing, and lyophilization, is shown to convert the brown birnessite into black birnessite with complex nanomorphology with folded sheets and spirals. Characterization of the product is performed by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), thermogravimetric analysis (TGA), and N2 adsorption (BET) techniques. Wet-aging and lyophilization times are shown to affect the architecture of the product. XRD patterns show a single phase corresponding to a semicrystalline birnessite-based manganese oxide. TEM studies suggest its fibrous and petal-like structures. The HRTEM images at 5 and 10 nm length scales reveal the fibrils in folding sheets and also show filamentary breaks. The BET surface area of this nanomaterial was found to be 10.6m2/g. The TGA measurement demonstrated that it possessed an excellent thermal stability up to 400◦C. Layerstructured black birnessite nanomaterial containing sheets, spirals, and filamentary breaks can be produced at low temperature (−49◦C) from brown birnessite without the use of cross-linking reagents

The effect of maternal vitamin D deficiency during pregnancy on glycolipid metabolism of offspring rats and the improvement of vitamin D intervention after weaning

BackgroundVitamin D deficiency during pregnancy is common, but whether maternal vitamin D status affects glycolipid metabolism of offspring remains unclear.ObjectiveTo evaluate the effect of maternal vitamin D deficiency during pregnancy on the glycolipid metabolism of offspring at different life-cycles (from birth to adulthood) and to explore the improvement of different dosages of vitamin D supplementation.MethodsSprague–Dawley rats were fed vitamin D-deprived (VDD group) or standard vitamin D diets (SC group) during pregnancy, and their diets were changed to standard vitamin D diets during lactation (the offspring were sorted into VDDoffspring and SCoffspring groups). After weaning, rats in the VDDoffspring group were randomly assigned to the VDDoffspring, VDDoffspring-S3300 and VDDoffspring-S10000 groups with diets containing standard, medium and high dosages of vitamin D for 12 wk. Serum was collected for biochemical analyses at postnatal Day 21, postnatal Day 56 and postnatal Day 84. Oral glucose tolerance test (OGTT) was performed at postnatal Day 70.ResultsCompared to SCoffspring, rats in the VDDoffspring group had significantly lower birth weight with faster weight gain and higher levels of lipid metabolism in early life. After near adulthood, the differences in weight and lipid metabolism between the two groups disappeared. OGTT showed significantly higher blood glucose levels in the VDDoffspring group at 30 min, 60 min, and 90 min. The continuation of vitamin D supplementation at medium and high dosages after weaning did not cause any obvious changes in weight or glycolipid metabolism (except for postprandial hyperglycemia). OGTT demonstrated that the glucose levels in the VDDoffspring-S3300 group were lowest at all the time points and that those in the VDDoffspring-S10000 group were the highest at 30 min, 60 min, and 90 min among the three groups.ConclusionThe adverse effects of vitamin D deficiency during pregnancy on glycolipid metabolism in offspring vary in different stages. Over a long time period, adequate vitamin D supplementation is beneficial to glycolipid metabolism for the offspring of subjects with vitamin D deficiency during pregnancy; however, further improvement is required

Chinese herbal compound for multidrug-resistant or extensively drug-resistant bacterial pneumonia: a meta-analysis and trial sequential analysis with association rule mining to identify core herb combinations

Purpose: Antibiotic-resistant bacterial pneumonia poses a significant therapeutic challenge. In China, Chinese herbal compound (CHC) is commonly used to treat bacterial pneumonia. We aimed to evaluate the efficacy and safety of CHC and identify core herb combinations for the treatment of multidrug-resistant or extensively drug-resistant bacterial pneumonia.Methods: Stata 16 and TSA 0.9.5.10 beta software were used for meta-analysis and trial sequential analysis (TSA), respectively. Exploring the sources of heterogeneity through meta-regression and subgroup analysis.Results: Thirty-eight studies involving 2890 patients were included in the analyses. Meta-analysis indicated that CHC combined with antibiotics improved the response rate (RR = 1.24; 95% CI: 1.19–1.28; p < 0.0001) and microbiological eradication (RR = 1.41; 95% CI: 1.27–1.57; p < 0.0001), lowered the white blood cell count (MD = −2.09; 95% CI: −2.65 to −1.53; p < 0.0001), procalcitonin levels (MD = −0.49; 95% CI: −0.59 to −0.40; p < 0.0001), C-reactive protein levels (MD = −11.80; 95% CI: −15.22 to −8.39; p < 0.0001), Clinical Pulmonary Infection Scores (CPIS) (MD = −1.97; 95% CI: −2.68 to −1.26; p < 0.0001), and Acute Physiology and Chronic Health Evaluation (APACHE)-II score (MD = −4.08; 95% CI: −5.16 to −3.00; p < 0.0001), shortened the length of hospitalization (MD = −4.79; 95% CI: −6.18 to −3.40; p < 0.0001), and reduced the number of adverse events. TSA indicated that the response rate and microbiological eradication results were robust. Moreover, Scutellaria baicalensis Georgi, Fritillaria thunbergii Miq, Lonicera japonica Thunb, and Glycyrrhiza uralensis Fisch were identified as core CHC prescription herbs.Conclusion: Compared with antibiotic treatment, CHC + antibiotic treatment was superior in improving response rate, microbiological eradication, inflammatory response, CPIS, and APACHE-II score and shortening the length of hospitalization. Association rule analysis identified four core herbs as promising candidates for treating antibiotic-resistant bacterial pneumonia. However, large-scale clinical studies are still required.Systematic Review Registration:https://www.crd.york.ac.uk/prospero/, identifier CRD42023410587

Biomarker records of D5-6 columns in the eastern Antarctic Peninsula waters: responses of planktonic communities and bio-pump structures to sea ice global warming in the past centenary

Molecular biomarkers (e.g., isoprenoid glycerol dialkyl glycerol tetraethers (iGDGTs) and proxies, such as di-unsaturated to tri-unsaturated highly branched isoprenoids (D/T) ratio, total organic carbon, δ13C and ice-rafted debris (IRD)) were used to reconstruct the dominant phytoplankton (diatoms, dinoflagellates and coccolithophores), phytoplankton and zooplankton productivity, biological pump structure, and archaea assemblage (Euryarchaeota and Crenarchaeota) from a marine sediment core (D5-6) dated with 210Pb (1922–2012). We characterized the environmental response to sea ice variations/global warming off the eastern Antarctic Peninsula. The results showed that (1) the biomarkers brassicasterol (average = 519.79 ng·g−1), dinosterol (average = 129.68 ng·g−1) and C37 alkenones (average = 40.53 ng·g−1) reconstructed phytoplankton (average = 690.00 ng·g−1) and zooplankton (cholesterol average = 669.25 ng·g−1) productivity. The relative contribution to productivity by different phytoplankton groups was diatoms > dinoflagellates > coccolithophores. This is consistent with field surveys showing that diatoms dominate the phytoplankton in waters adjacent to the Antarctic Peninsula. (2) The relative abundances of different highly branched isoprenoids reflected the contributions of sea ice algae and open water phytoplankton (D/T = 1.2–30.15). Phytoplankton productivity and sea ice showed a good linear relationship with a negative correlation, indicating that more open water during periods of warming and reduced sea ice cover led to an enhanced biological pump. (3) Over the past 100 years, phytoplankton productivity and zooplankton biomass increased. This trend was particularly evident in the last 50 years, corresponding to increased global warming, and showed a negative correlation with IRD and D/T. This suggests that with decreasing sea ice coverage in a warming climate, diatom biomass greatly increased. Coccolithophore/diatom values and the ratio of C37 alkenones to total phytoplankton productivity decreased, indicating the proportion of coccolithophores in the phytoplankton community decreased. The reduction in coccolithophores changes the phytoplankton assemblage and affects the overall efficiency of the biological pump and carbon storage. (4) The results also showed that the abundance of iGDGTs and archaea phyla (Euryarchaeota and Crenarchaeota) showed consistent changes over the past 100 years in response to global warming. Since 1972, trends in archaea, phytoplankton and zooplankton showed variations but a consistent decline. Whether their response to the changing climate off the Antarctic Peninsula involves interactions and influence among different marine biological groups remains an open question. As a result of global warming and reductions in Antarctic sea ice, the relative effectiveness of the Antarctic biological pump can significantly affect global ocean carbon storage

Ascl2 Knockdown Results in Tumor Growth Arrest by miRNA-302b-Related Inhibition of Colon Cancer Progenitor Cells

Background: Achaete scute-like 2 (Ascl2), a basic helix-loop-helix (bHLH) transcription factor, controls the fate of intestinal stem cells. However, the role of Ascl2 in colon cancer progenitor cells remains unknown. The cell line HT-29 (47.5–95 % of CD133 + population) and LS174T (0.45 % of CD133 + population) were chosen for functional evaluation of Ascl2 in colon cancer progenitor cells after gene knockdown by RNA interference. Methodology/Principal Findings: Immunohistochemistry demonstrated that Ascl2 was significantly increased in colorectal adenocarcinomas. Downregulation of Ascl2 using RNA interference in cultured colonic adenocarcinoma HT-29 and LS174T cells reduced cellular proliferation, colony-forming ability, invasion and migration in vitro, and resulted in the growth arrest of tumor xenografts in vivo. The Ascl2 protein level in CD133 + HT-29 cells was significantly higher than in CD133 2 HT-29 cells. Ascl2 blockade via shRNA interference in HT-29 cells (shRNA-Ascl2/HT-29 cells) resulted in 26.2 % of cells staining CD133 + compared with 54.7 % in control shRNA-Ctr/HT-29 cells. The levels of ‘stemness ’ associated genes, such as CD133, Sox2, Oct4, Lgr5, Bmi1, and C-myc, were significantly decreased in shRNA-Ascl2/HT-29 and shRNA-Ascl2/LS174T cells in vitro as well as in the corresponding tumor xenograft (CD133 was not performed in shRNA-Ascl2/LS174T cells). The shRNA-Ascl2/ HT-29 cells had inhibited abilities to form tumorspheres compared with control. The microRNA (miRNAs) microarrays, identified 26 up-regulated miRNAs and 58 down-regulated miRNAs in shRNA-Ascl2/HT-29 cells. Expression levels of let-7b

Lossy-Forward Relaying for Lossy Communications: Rate-Distortion and Outage Probability Analyses

This paper presents an in-depth performance analysis of lossy communications in a single-relay system, where the recovered information is not necessarily lossless in both the relay and the destination. In this system, the relay continues transmitting the sequence with source-relay link errors to the destination even if errors are detected after decoding, i.e., so-called Lossy-Forward (LF) strategy. The problem can be decomposed into two parts as follows: a point-to-point coding problem in the source-relay (S-R) link, and a lossy source coding problem with a LF relay in the source-destination (S-D) and relay-destination (R-D) links. To begin with, we derive the admissible rate region of the lossy source coding problem with a LF relay for a specified distortion requirement. Then, we focus on the analysis of outage probability over block Rayleigh fading channels. Finally, a practical encoding/decoding scheme is proposed for the evaluation of system performance by computer simulations. Due to the suboptimal channel coding and incomplete utilization of joint typicality, the theoretical performance cannot be achieved in the simulation; however, the tendency of curves in simulations matches that in theoretical calculation

Initial intravitreal injection of high-dose ganciclovir for cytomegalovirus retinitis in HIV-negative patients

Abstract Background The purpose of this study is to examine the clinical outcomes achieved by using initial high-dose intravitreal ganciclovir injections to treat cytomegalovirus retinitis in patients without human immunodeficiency virus (HIV) infection. Methods Twenty-four eyes (24 patients) with cytomegalovirus retinitis received multiple intravitreal injections of ganciclovir in weekly intervals. A higher dose (6 mg) of ganciclovir was applied at the first intravitreal injection, and a lower dose was used for maintenance. Anterior aqueous humour was obtained before each injection. The best-corrected visual acuity and cytomegalovirus loads in the anterior aqueous humour were measured. Results The mean cytomegalovirus DNA load in aqueous humour decreased significantly from (2.59 ± 2.28) × 105 copies/mL at baseline to (1 ± 1.76) × 104 copies/mL one month later. The aqueous cytomegalovirus DNA load was negative in 17 eyes (70.8%) one month later. No obvious improvement of best-corrected visual acuity was found during the treatment. A positive correlation was proven between initial cytomegalovirus DNA titers in aqueous humour and the total number of intravitreal injections of ganciclovir, as well as between the baseline and final best-corrected visual acuities. No severe complications developed. Conclusions An initial high dose of ganciclovir (6 mg) and continuous intravitreal injections of ganciclovir could significantly decrease the cytomegalovirus load in HIV-negative patients with cytomegalovirus retinitis. Trial registration http://clinicaltrials.gov, NCT03598452, retrospectively registered on 24 July 2018

Electrophoretic Motion of a Spherical Particle with a Symmetric nonuniform Surface Charge Distribution in a nanotube

The electrophoretic motion of a spherical nanoparticle, subject to an axial electric field in a nanotube filled with an electrolyte solution, has been investigated using a continuum theory, which consists of the Nernst-Planck equations for the ionic concentrations, the Poisson equation for the electric potential in the solution, and the Stokes equation for the hydrodynamic field. In particular, the effects of nonuniform surface charge distributions around the nanoparticle on its axial electrophoretic motion are examined with changes in the bulk electrolyte concentration and the surface charge of the tube\u27s wall. A particle with a nonuniform charge distribution is shown to induce a corresponding complex ionic concentration field, which in turn influences the electric field and the fluid motion surrounding the particle and thus its electrophoretic velocity. As a result, contrary to the relatively simple dynamics of a particle with a uniform surface charge, dominated by the irradiating electrostatic force, that with a nonuniform surface charge distribution shows various intriguing behaviors due to the additional interplay of the nonuniform electro-osmotic effects