Organic photovoltaics are an important part of a next‐generation energy‐harvesting technology that uses a practically infinite pollutant‐free energy source. They have the advantages of light weight, ...solution processability, cheap materials, low production cost, and deformability. However, to date, the moderate photovoltaic efficiencies and poor stabilities of organic photovoltaics impede their use as replacements for inorganic photovoltaics. Recent developments in bulk‐heterojunction organic photovoltaics mean that they have almost reached the lower efficiency limit for feasible commercialization. In this review article, the recent understanding of the ideal bulk‐heterojunction morphology of the photoactive layer for efficient exciton dissociation and charge transport is described, and recent attempts as well as early‐stage trials to realize this ideal morphology are discussed systematically from a morphological viewpoint. The various approaches to optimizing morphologies consisting of an interpenetrating bicontinuous network with appropriate domain sizes and mixed regions are categorized, and in each category, the recent trends in the morphology control on the multilength scale are highlighted and discussed in detail. This review article concludes by identifying the remaining challenges for the control of active layer morphologies and by providing perspectives toward real application and commercialization of organic photovoltaics.
The morphology of the bulk‐heterojunction photoactive layer critically influences charge‐carrier dynamics and therefore the overall photovoltaic performance of organic photovoltaics. The morphological issues reported so far are discussed and future directions toward further optimization are suggested.
Acinetobacter baumannii is an opportunistic pathogen that causes serious nosocomial infection in intensive care units. In particular, carbapenem-resistant A. baumannii (CRAB) strains have been ...increasing in the past decade, and they have caused major medical problems worldwide. In this study, a novel A. baumannii lytic phage, the YMC 13/03/R2096 ABA BP (phage Βϕ-R2096), which specifically causes the lysis of CRAB strains, was characterized in detail in vitro and in silico, and the in vivo effectiveness of phage therapy was evaluated using Galleria mellonella and a mouse model of acute pneumonia.
The A. baumannii phage Βϕ-R2096 was isolated from sewage water using CRAB clinical strains selected from patients at a university hospital in South Korea. The complete genome of the phage Βϕ-R2096, which belongs to the Myoviridae family, was analyzed. Phage Βϕ-R2096 inhibited bacterial growth in a dose-dependent manner and exhibited high bacteriolytic activity at MOI = 10. In the evaluation of its therapeutic potential against CRAB clinical isolates using two in vivo models, phage Βϕ-R2096 increased the survival rates of both G. mellonella larvae (from 0 to 50% at 24 h) and mice (from 30% with MOI = 0.1 to 100% with MOI = 10 for 12 days) in post-infection of CRAB. In particular, phage Βϕ-R2096 strongly ameliorated histologic damage to infected lungs, with bacterial clearance in the lungs observed on day 3 postinfection in the mouse acute pneumonia model. Moreover, in vivo studies revealed no mortality or serious side effects in phage-treated groups.
The results of this study strongly suggest that phage Βϕ-R2096, a novel A. baumannii lytic phage, could be an alternative antibacterial agent to control CRAB infections. This study is the first report to compare in vivo evaluations (G. mellonella larvae and a mouse acute pneumonia model) of the therapeutic efficacy of a phage against CRAB infections.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
•Sesame straw biochar demonstrated an excellent adsorption capacity for heavy metals.•Adsorption fitted best with Langmuir model as compared to the Freundlich model.•High interference among the ...metals was observed under multimetal sorption condition.•The highest reduction in adsorption capacity was found for Cd.•Adsorption behaviors was well described by three-dimensional simulation.
Objective of this research was to evaluate adsorption of heavy metals in mono and multimetal forms onto sesame straw biochar (SSB). Competitive sorption of metals by SSB has never been reported previously. The maximum adsorption capacities (mgg−1) of metals by SSB were in the order of Pb (102)≫Cd (86)≫Cr (65)>Cu (55)≫Zn (34) in the monometal adsorption isotherm and Pb (88)≫Cu (40)≫Cr (21)>Zn (7)⩾Cd (5) in the multimetal adsorption isotherm. Based on data obtained from the distribution coefficients, Freundlich and Langmuir adsorption models, and three-dimensional simulation, multimetal adsorption behaviors differed from monometal adsorption due to competition. Especially, during multimetal adsorption, Cd was easily exchanged and substituted by other metals. Further competitive adsorption studies are necessary in order to accurately estimate the heavy metal adsorption capacity of biochar in natural environments.
Rapid change and zoonotic transmission to humans have enhanced the virulence of the influenza A virus (IAV). Neutralizing antibodies fail to provide lasting protection from seasonal epidemics. ...Furthermore, the effectiveness of anti-influenza neuraminidase inhibitors has declined because of drug resistance. Drugs that can block viral attachment and cell entry independent of antigenic evolution or drug resistance might address these problems. We show that multivalent 6'-sialyllactose-polyamidoamine (6SL-PAMAM) conjugates, when designed to have well-defined ligand valencies and spacings, can effectively inhibit IAV infection. Generation 4 (G4) 6SL-PAMAM conjugates with a spacing of around 3 nm between 6SL ligands (S3-G4) showed the strongest binding to a hemagglutinin trimer (dissociation constant of 1.6 × 10
M) and afforded the best inhibition of H1N1 infection. S3-G4 conjugates were resistant to hydrolysis by H1N1 neuraminidase. These conjugates protected 75% of mice from a lethal challenge with H1N1 and prevented weight loss in infected animals. The structure-based design of multivalent nanomaterials, involving modulation of nanoscale backbone structures and number and spacing between ligands, resulted in optimal inhibition of IAV infection. This approach may be broadly applicable for designing effective and enduring therapeutic protection against human or avian influenza viruses.
Helicobacter pylori colonization of the stomach affects about half of the world population and is associated with the development of gastritis, ulcers, and cancer. Polymorphisms in the IL1B gene are ...linked to an increased risk of H. pylori associated cancer, but the bacterial and host factors that regulate interleukin (IL)‐1β production in response to H. pylori infection remain unknown. Using murine BM‐derived DCs, we show that the bacterial virulence factors cytotoxin‐associated genes pathogenicity island and CagL, but not vacuolating cytotoxin A or CagA, regulate the induction of pro‐IL‐1β and the production of mature IL‐1β in response to H. pylori infection. We further show that the host receptors, Toll‐like receptor 2 (TLR2) and nucleotide‐binding oligomerization domain 2 (NOD2), but not NOD1, are required for induction of pro‐IL‐1β and NOD‐like receptor pyrin domain containing 3 (NLRP3) in H. pylori infected DCs. In contrast, NLRP3 and the adaptor ASC were essential for the activation of caspase‐1, processing of pro‐IL‐1β into IL‐1β, and IL‐1β secretion. Finally, we show that mice deficient in caspase‐1, IL‐1β, and IL‐1 receptor, but not NLRP3, are impaired in the clearance of CagA‐positive H. pylori from the stomach when compared with WT mice. These studies identify bacterial cag pathogenicity island and the cooperative interaction among host innate receptors TLR2, NOD2, and NLRP3 as important regulators of IL‐1β production in H. pylori infected DCs.
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This study investigated the characteristics of biochars derived using various pine tree residues and pyrolysis temperatures and evaluated their Cd adsorption behaviors. The ...characteristics of pine tree residue biochars (PRBs) were dominantly affected by the pyrolysis temperature, and the optimum pyrolysis temperature for Cd adsorption was 600 °C. The adsorption of Cd by PRBs was divided into two stages: rapid adsorption on the initial boundary layer and slow adsorption by intraparticle diffusion. The Cd adsorption characteristics of all the PRBs were well described by pseudo-second-order and Langmuir isotherm models, and the maximum adsorption capacity was the highest in pine bark biochar (85.8 mg/g). The amounts of the cations released from the mixed pine tree residue biochars (M-PRBs) during Cd adsorption were increased, while the amount of phosphate released was decreased, indicating that exchangeable cations and phosphate on the biochar affected the Cd adsorption. In particular, the amount of Cd removed by the exchangeable cations corresponds to 23.6% of the total adsorption amount. Spectroscopic analyses using FTIR showed that the Cd adsorption on M-PRB was associated with functional groups such as CC, COH and COOH. Overall, the use of biochars derived from pine tree residue as an adsorbent is considered to be effective for both the treatment of wastewater containing heavy metals and the recycling of forest residues.
Enhanced performance of an inverted‐type polymer solar cell is reported by controlling the surface energy of a zinc oxide (ZnO) buffer layer, on which a photoactive layer composed of a ...polymer:fullerene‐derivative bulk heterojunction is formed. With the approach based on a mixed self‐assembled monolayer, the surface energy of the ZnO buffer layer can be controlled between 40 mN m−1 and 70 mN m−1 with negligible changes in its work function. For the given range of surface energy the power conversion efficiency increases from 3.27% to 3.70% through enhanced photocurrents. The optimized morphology obtained by surface energy control results in the enhanced photocurrent and transmission electron microscopy analysis verifies the correlation between the surface energy and the phase morphology of the bulk heterojunction. These results demonstrate that surface energy control is an effective method for further improving the performance of polymer solar cells, with potentially important implications for other organic devices containing an interface between a blended organic active layer and a buffer or an electrode layer.
Enhanced power conversion efficiency in polymer solar cells is achieved by surface energy control. Surface modification based on a mixed self‐assembled monolayer allows the independent control of the surface energy and work function. These results demonstrate that controlling the surface energy of a buffer layer that lies underneath a photoactive layer is an effective method for improving the performance in polymer solar cells.
The development of cost-effective and high-performance oxygen evolution reaction (OER) catalysts is a significant challenge. This study presents the synthesis of binder-free NiFe@NiFe layered double ...hydroxide (NNF) via one-pot electrodeposition on carbon paper and Ni foam at high current densities. The presence of Ni sulfate residues on the prepared NNF is also investigated. The findings indicate that Ni sulfate significantly improves OER performance and durability. The sulfate content can be controlled by varying the method and duration of washing. NNF prepared through dipping (NNF-D) exhibits outstanding OER activity with a low overpotential of 241 mV, which is 25 mV lower than that of NNF washed for 60 s (NNF-W-60 s) at 10 mA cm
in 1 m KOH. Furthermore, density functional theory analyses indicate that the Ni sulfate residue helps modify the electronic structure, thereby optimizing the binding strength of *OOH. This synthetic strategy is expected to inspire the development of next-generation catalysts utilizing various adsorbates.
Background & Aims Decreased levels or function of nucleotide-binding oligomerization domain 2 (NOD2) are associated with Crohn's disease. NOD2 regulates intestinal inflammation, and also is expressed ...by human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs), to regulate their differentiation. We investigated whether NOD2 is required for the anti-inflammatory activities of MSCs in mice with colitis. Methods Colitis was induced in mice by administration of dextran sulfate sodium or trinitrobenzene sulfonic acid. Mice then were given intraperitoneal injections of NOD2-activated hUCB-MSCs; colon tissues and mesenteric lymph nodes were collected for histologic analyses. A bromodeoxyuridine assay was used to determine the ability of hUCB-MSCs to inhibit proliferation of human mononuclear cells in culture. Results Administration of hUCB-MSCs reduced the severity of colitis in mice. The anti-inflammatory effects of hUCB-MSCs were greatly increased by activation of NOD2 by its ligand, muramyl dipeptide (MDP). Administration of NOD2-activated hUCB-MSCs increased anti-inflammatory responses in colons of mice, such as production of interleukin (IL)-10 and infiltration by T regulatory cells, and reduced production of inflammatory cytokines. Proliferation of mononuclear cells was inhibited significantly by co-culture with hUCB-MSCs that had been stimulated with MDP. MDP induced prolonged production of prostaglandin (PG)E2 in hUCB-MSCs via the NOD2–RIP2 pathway, which suppressed proliferation of mononuclear cells derived from hUCB. PGE2 produced by hUCB-MSCs in response to MDP increased production of IL-10 and T regulatory cells. In mice, production of PGE2 by MSCs and subsequent production of IL-10 were required to reduce the severity of colitis. Conclusions Activation of NOD2 is required for the ability of hUCB-MSCs to reduce the severity of colitis in mice. NOD2 signaling increases the ability of these cells to suppress mononuclear cell proliferation by inducing production of PGE2.
A limited number of studies have used objective measures to examine the associations between the built environment and physical activity (PA) among older adults. This study aimed to examine ...geographic information systems-derived neighborhood walkability attributes and accelerometer measured PA in older adults. Data were collected from 124 older Taiwanese adults aged over 60 years (mean age: 69.9). Adjusted multiple linear regression was performed to explore the associations between five neighborhood walkability factors (population density, street connectivity, sidewalk availability, access to destinations, and public transportation) and five metrics of accelerometer-measured physical activity (total PA, moderate-to-vigorous PA, light PA, long moderate-to-vigorous PA bouts, and daily step counts). After adjusting for potential confounders, we found that greater sidewalk availability was positively associated with daily step counts in older adults (β = 0.165; 95% confidence interval: 0.006, 0.412; P = 0.043). No associations between other neighborhood environment attributes and PA metrics were observed. In conclusion, high sidewalk availability in the neighborhood may be supportive for older adults' daily step counts. Further longitudinal research is needed to establish the causality between the built environment and objectively measured PA in older adults.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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