Formation Mechanism and Control of Perovskite Films from Solution to Crystalline Phase Studied by in Situ Synchrotron Scattering

Controlling the crystallization and morphology of perovskite films is crucial for the fabrication of high-efficiency perovskite solar cells. For the first time, we investigate the formation mechanism of the drop-cast perovskite film from its precursor solution, PbCl₂ and CH₃NH₃I in <i>N</i>,<i>N</i>-dimethylformamide, to a crystalline CH₃NH₃PbI_3–<i>x</i>Cl_<i>x</i> film at different substrate temperatures from 70 to 180 °C in ambient air and humidity. We employed an in situ grazing-incidence wide-angle X-ray scattering (GIWAXS) technique for this study. When the substrate temperature is at or below 100 °C, the perovskite film is formed in three stages: the initial solution stage, transition-to-solid film stage, and transformation stage from intermediates into a crystalline perovskite film. In each stage, the multiple routes for phase transformations are preceded concurrently. However, when the substrate temperature is increased from 100 to 180 °C, the formation mechanism of the perovskite film is changed from the “multistage formation mechanism” to the “direct formation mechanism”. The proposed mechanism has been applied to understand the formation of a perovskite film containing an additive. The result of this study provides a fundamental understanding of the functions of the solvent and additive in the solution and transition states to the crystalline film. It provides useful knowledge to design and fabricate crystalline perovskite films for high-efficiency solar cells

Additional file 1 of De Garengeot Hernia, an acute appendicitis in the right femoral hernia canal, and successful management with transabdominal closure and appendectomy: a case Report

Supplementary Material

Tuning Perovskite Morphology by Polymer Additive for High Efficiency Solar Cell

Solution processable planar heterojunction perovskite solar cell is a very promising new technology for low cost renewable energy. One of the most common cell structures is FTO/TiO₂/CH₃NH₃PbI_3‑<i>x</i>Cl_<i>x</i>/spiro-OMeTAD/Au. The main issues of this type of solar cell are the poor coverage and morphology control of the perovskite CH₃NH₃PbI_3‑<i>x</i>Cl_<i>x</i> film on TiO₂. For the first time, we demonstrate that the problems can be easily resolved by using a polymer additive in perovskite precursor solution during the film formation process. A 25% increase in power conversion efficiency at a value of 13.2% is achieved by adding 1 wt % of poly­(ethylene glycol) in the perovskite layer using a 150 °C processed TiO₂ nanoparticle layer. The morphology of this new perovskite was carefully studied by SEM, XRD, and AFM. The results reveal that the additive controls the size and aggregation of perovskite crystals and helps the formation of smooth film over TiO₂ completely. Thus, the <i>V</i>_oc and <i>J</i>_sc are greatly increased for a high efficiency solar cell. The amount of additive is optimized at 1 wt % due to its insulating characteristics. This research provides a facile way to fabricate a high efficiency perovskite solar cell by the low temperature solution process (<150 °C), which has the advancement of conserving energy over the traditional high temperature sintering TiO₂ compact layer device

Additional file 1: of Association between autophagy and inflammation in patients with rheumatoid arthritis receiving biologic therapy

Figure S1. Representative cytometric histograms of Cyto-ID staining in circulating CD4+ T cells (A1), CD8+ T cells (A2), and CD19+ B cells (A3) from one patient with rheumatoid arthritis (RA) and one healthy control subject (HC). Comparisons of autophagosome levels reflected by Cyto-ID-staining MFI, in CD4+ T cells (B), CD8+ T cells (C) and CD19+ B cells (D) between patients with RA and HC. Data are presented as box plot diagrams, with the box encompassing the 25th percentile (lower bar) to the 75th percentile (upper bar). The horizontal line within the box indicates median value for each group. *p < 0.05 versus HC. Representative cytometric histograms of Cyto-ID staining in peripheral blood (PB)-derived granulocytes (E) and synovial fluid (SF)-derived granulocytes (F). Comparisons of autophagosome levels in PB-derived and SF-derived granulocytes in patients with RA (G). (TIF 1427 kb

Molecular Structure Effect of Pyridine-Based Surface Ligand on the Performance of P3HT:TiO₂ Hybrid Solar Cell

Colloid TiO2 nanorods are used for solution-processable poly­(3-hexyl thiophene): TiO2 hybrid solar cell. The nanorods were covered by insulating ligand of oleic acid (OA) after sol-gel synthesis. Three more conducting pyridine type ligands: pyridine, 2,6-lutidine (Lut) and 4-tert-butylpyridine (tBP) were investigated respectively to replace OA. The power conversion efficiency (PCE) of the solar cell was increased because the electronic mobility of pyridine-type ligand-modified TiO2 is higher than that of TiO2–OA. The enhancement of PCE is in the descending order of Lut > pyridine > tBP because of the effective replacement of OA by Lut. The PCE of solar cell can be further enhanced by ligand exchange of pyridine type ligand with conjugating molecule of 2-cyano-3-(5-(7-(thiophen-2-yl)-benzothiadiazol-4-yl) thiophen-2-yl) acrylic acid (W4) on TiO2 nanorods because W4 has aligned bandgap with P3HT and TiO2 to facilitate charge separation and transport. The electronic mobility of two-stage ligand exchanged TiO2 is improved furthermore except Lut, because it adheres well and difficult to be replaced by W4. The amount of W4 on TiO2-tBP is 3 times more than that of TiO2–Lut (0.20 mol % vs. 0.06 mol %). Thus, the increased extent of PCE of solar cell is in the decreasing order of tBP > pyridine > Lut. The TiO2-tBP-W4 device has the best performance with 1.4 and 2.6 times more than TiO2-pyridine-W4 and TiO2-Lut-W4 devices, respectively. The pKa of the pyridine derivatives plays the major role to determine the ease of ligand exchange on TiO2 which is the key factor mandating the PCE of P3HT:TiO2 hybrid solar cell. The results of this study provide new insights of the significance of acid-base reaction on the TiO2 surface for TiO2-based solar cells. The obtained knowledge can be extended to other hybrid solar cell systems

Data_Sheet_1_Shock index, modified shock index, age shock index score, and reverse shock index multiplied by Glasgow Coma Scale predicting clinical outcomes in traumatic brain injury: Evidence from a 10-year analysis in a single center.docx

ObjectivesEarly identification of traumatic brain injury (TBI) patients at a high risk of mortality is very important. This study aimed to compare the predictive accuracy of four scoring systems in TBI, including shock index (SI), modified shock index (MSI), age-adjusted shock index (ASI), and reverse shock index multiplied by the Glasgow Coma Scale (rSIG).Patients and methodsThis is a retrospective analysis of a registry from the Taipei Tzu Chi trauma database. Totally, 1,791 patients with TBI were included. We investigated the accuracy of four major shock indices for TBI mortality. In the subgroup analysis, we also analyzed the effects of age, injury mechanism, underlying diseases, TBI severity, and injury severity.ResultsThe predictive accuracy of rSIG was significantly higher than those of SI, MSI, and ASI in all the patients [area under the receiver operating characteristic curve (AUROC), 0.710 vs. 0.495 vs. 0.527 vs. 0.598], especially in the moderate/severe TBI (AUROC, 0.625 vs. 0.450 vs. 0.476 vs. 0.529) and isolated head injury populations (AUROC 0.689 vs. 0.472 vs. 0.504 vs. 0.587). In the subgroup analysis, the prediction accuracy of mortality of rSIG was better in TBI with major trauma [Injury Severity Score (ISS) ≥ 16], motor vehicle collisions, fall injury, and healthy and cardiovascular disease population. rSIG also had a better prediction effect, as compared to SI, MSI, and ASI, both in the non-geriatric (age ConclusionrSIG had a better prediction accuracy for mortality in the overall TBI population than SI, MSI, and ASI. Although rSIG have better accuracy than other indices (ROC values indicate poor to moderate accuracy), the further clinical studies are necessary to validate our results.</p

Characteristic comparison of WT and MDR NAs.

<p>Binding site residues of (A) MDR and (B) WT NAs. The binding site was divided into the 5 subsites S1 (R118, R293, and R368), S2 (E119, D151, W179, and E228), S3 (R152, W179, and I223), S4 (I223, R225, and S247), and S5 (S247 and E277). The negative/positive, polar, hydrophobic, and mixed hydrophobic and polar subsites are shown as red, green, gray, and orange curves, respectively. These residues are shown in N1 numbering. Molecular surfaces represented by electrostatic potentials of (C) MDR and (D) WT NAs. The negative, positive, and neutral/hydrophobic potentials are colored red, blue, and white, respectively.</p

Inhibition of influenza infection and replication by RB19 in MDCK cells.

<p>(A) RB19 inhibits the influenza-induced cytopathic effect. In the antiviral neutralization test, MDCK cells were lysed 64 h after A/WSN/33 infection, as shown in the VC (virus control) column. The agent RB19 was added to A/WSN/33-infected cells by two-fold serial dilution starting with a concentration of 50 µM (leftmost column). (B) Reduction in viral yields from infected cells treat w/o RB19 at different concentrations. MDCK cells were infected with MOI 0.001 A/WSN/33 (H1N1) and various concentrations of RB19 were added at the adsorption stage of the A/WSN/33 replication cycle. At 48 h post infection, culture supernatants were collected for virus titration using neuraminidase activity to monitor the viral yield. (C) Inhibition of influenza virus plaque formation by RB19. Approximately 50–100 PFU/well of A/WSN/33 (H1N1) or A/Udorn/72 (H3N2) of influenza A virus was used to infect MDCK cells in 6-well plates. After the viral adsorption stage, 3 ml of agar was overlayed on the media containing various concentrations of RB19. The concentration of RB19 is indicated at the top.</p

Interaction preference of mutant site.

<p>Interacting atom distributions of compounds on (A) MDR and (B) WT NAs. The interacting atoms are shown as grids if interacting with the binding site by electrostatic (yellow), hydrogen-bonding (dark green), and van der Waals (gray) interactions. (C) Protein-compound interaction profiles. An entry is colored green if the screening compound yielded interactions with the residues; conversely, the entry color is black. The red frame shows the major difference of interaction preferences between WT and MDR NAs. (D) Interaction percentages of residues in the profiles.</p

Parallel Screening of Wild-Type and Drug-Resistant Targets for Anti-Resistance Neuraminidase Inhibitors

<div><p>Infection with influenza virus is a major public health problem, causing serious illness and death each year. Emergence of drug-resistant influenza virus strains limits the effectiveness of drug treatment. Importantly, a dual H275Y/I223R mutation detected in the pandemic influenza A 2009 virus strain results in multidrug resistance to current neuraminidase (NA) drugs. Therefore, discovery of new agents for treating multiple drug-resistant (MDR) influenza virus infections is important. Here, we propose a parallel screening strategy that simultaneously screens wild-type (WT) and MDR NAs, and identifies inhibitors matching the subsite characteristics of both NA-binding sites. These may maintain their potency when drug-resistant mutations arise. Initially, we analyzed the subsite of the dual H275Y/I223R NA mutant. Analysis of the site-moiety maps of NA protein structures show that the mutant subsite has a relatively small volume and is highly polar compared with the WT subsite. Moreover, the mutant subsite has a high preference for forming hydrogen-bonding interactions with polar moieties. These changes may drive multidrug resistance. Using this strategy, we identified a new inhibitor, Remazol Brilliant Blue R (RB19, an anthraquinone dye), which inhibited WT NA and MDR NA with IC₅₀ values of 3.4 and 4.5 µM, respectively. RB19 comprises a rigid core scaffold and a flexible chain with a large polar moiety. The former interacts with highly conserved residues, decreasing the probability of resistance. The latter forms van der Waals contacts with the WT subsite and yields hydrogen bonds with the mutant subsite by switching the orientation of its flexible side chain. Both scaffolds of RB19 are good starting points for lead optimization. The results reveal a parallel screening strategy for identifying resistance mechanisms and discovering anti-resistance neuraminidase inhibitors. We believe that this strategy may be applied to other diseases with high mutation rates, such as cancer and human immunodeficiency virus type 1.</p> </div