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The leakage of noxious lead and the instability of perovskite film induced by interfacial defects have impeded the practical application of perovskite solar cells (PSCs). Here, we develop a perovskite surface management strategy by the post-treatment with a copper porphyrin containing thiol and secondary amine group (Cu-Por). The thiol-terminal in Cu-Por can coordinate with the Pb defects on the perovskite surface. The central Cu2+ ions in Cu-Por tune the electron distribution within porphyrin ring, thereby effectively binding the I− and I2 on the perovskite surface by π-I interaction and the hydrogen-bonds between the side chain N–H group with I− and I2. Finally, the Cu-Por-treated PSCs gave the best efficiency of 21.24%. More importantly, the modified device maintained over 90% of its initial efficiency under AM 1.5G illumination or heated at 85 °C in N2 atmosphere after 2000 h. Especially, the Cu-Por treated PSCs can prevent the leakage of lead. This finding provides a new perovskite surface management strategy to fabricate the stable and clean PSCs.

// Ju-Chi Liu 1, 4, * , Tsung-Yeh Yang 1, * , Yi-Ping Hsu 1 , Wen-Rui Hao 1 , Pai-Feng Kao 1, 4 , Li-Chin Sung 1, 4 , Chun-Chao Chen 1 , Szu-Yuan Wu 2, 3, 4, 5 1 Division of Cardiovascular Medicine, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan 2 Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, Taiwan 3 Department of Radiation Oncology, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan 4 Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan 5 Department of Biotechnology, Hungkuang University, Taichung, Taiwan * Co-first authors, These authors contributed equally to this work Correspondence to: Szu-Yuan Wu, email: szuyuanwu5399@gmail.com Keywords: statins, COPD, lung cancer Received: March 09, 2016 Accepted: July 09, 2016 Published: August 09, 2016 ABSTRACT Purpose: Chronic obstructive pulmonary disease (COPD) is associated with increased lung cancer risk. We evaluated the association of statin use with lung cancer risk in COPD patients and identified which statins possess the highest chemopreventive potential. Results: After adjustment for age, sex, CCI, diabetes, hypertension, dyslipidemia, urbanization level, and monthly income according to propensity scores, lung cancer risk in the statin users was lower than that in the statin nonusers (adjusted hazard ratio [aHR] = 0.37). Of the individual statins, lovastatin and fluvastatin did not reduce lung cancer risk significantly. By contrast, lung cancer risk in patients using rosuvastatin, simvastatin, atorvastatin, and pravastatin was significantly lower than that in statin nonusers (aHRs = 0.41, 0.44, 0.52, and 0.58, respectively). Statins dose-dependently reduced lung cancer risk in all subgroups and the main model with additional covariates (nonstatin drug use). Materials and Methods: The study cohort comprised all patients diagnosed with COPD at health care facilities in Taiwan ( n = 116,017) between January 1, 2001 and December 31, 2012. Our final study cohort comprised 43,802 COPD patients: 10,086 used statins, whereas 33,716 did not. Patients were followed up to assess lung cancer risk or protective factors. In addition, we also considered demographic characteristics, namely age, sex, comorbidities (diabetes, hypertension, dyslipidemia, and Charlson comorbidity index [CCI]), urbanization level, monthly income, and nonstatin drug use. The index date of statin use was the COPD confirmation date. To examine the dose–response relationship, we categorized statin use into four groups in each cohort: 365 cumulative defined daily doses (cDDDs). Patients receiving < 28 cDDDs were defined as nonstatin users. Conclusions: Statins dose-dependently exert a significant chemopreventive effect against lung cancer in COPD patients. Rosuvastatin, simvastatin, and atorvastatin exhibited the highest chemopreventive potential.

PURPOSE: Chronic obstructive pulmonary disease (COPD) is associated with an increased cancer risk. We evaluated the chemopreventive effect of statins against all cancers in COPD patients and identified the statin with the strongest chemopreventive effect. PATIENTS AND METHODS: All patients diagnosed with COPD at health care facilities in Taiwan (n = 116,017) from January 1, 2001, to December 31, 2012, were recruited. Each patient was followed to assess the following protective and risk factors for all cancers: age; sex; comorbidities (diabetes, hypertension, dyslipidemia) and the Charlson comorbidity index [CCI]); urbanization level; monthly income; and nonstatin drug use. The index date of statins use was the date of COPD confirmation. Propensity scores (PSs) were derived using a logistic regression model to estimate the effect of statins by considering the covariates predicting intervention (statins) receipt. To examine the dose-response relationship, we categorized statin use into four groups in each cohort (365 cumulative defined daily dose). RESULTS: After PS adjustment for age, sex, CCI, diabetes, hypertension, dyslipidemia, urbanization level, and monthly income, we analyzed the all-cancer risk. The adjusted hazard ratios (aHRs) for the all-cancer risk were lower among statin users than among statin nonusers (aHR = 0.46, 95% confidence interval: 0.43 to 0.50). The aHRs for the all-cancer risk were lower among patients using rosuvastatin, simvastatin, atorvastatin, pravastatin, and fluvastatin than among statin nonusers (aHRs = 0.42, 0.55, 0.59, 0.66, and 0.78, respectively). Sensitivity analysis indicated that statins dose-dependently reduced the all-cancer risk. CONCLUSION: Statins dose-dependently exert a significant chemopreventive effect against various cancers in COPD patients. In particular, rosuvastatin has the strongest chemopreventive effect.

Transient electronics are of great interest for applications in biomedical implants, hardware secure technologies and environmental friendly consumer devices. However, most transient devices having been reported require high temperature and high vacuum for fabrication, which is inconsistent with the ‘green’ idea of transient electronics. Besides, there are less reports on the degradation behavior of semiconducting metal oxides and organic semiconductors, particularly on the evolution of surface states. Herein, we demonstrated a transient diode based on zinc oxide and poly(3,4-ethylenedioxythiophene) polystyrene sulfonate, synthesized by a set of low-cost and green methods. The degradation behavior of the semiconducting films was addressed by electrochemical impedance spectroscopy, which simultaneously revealing the evolution of resistance, capacitance and surface states. The diode was able to operate properly in appropriate conditions and degraded easily in aqueous solution.

We would like to take this opportunity to highlight the Outstanding Reviewers for Materials Horizons in 2019, as selected by the editorial team for their significant contribution to the journal.

Aims Most left atrial tachycardia (LAT) is associated with atrial fibrillation (AF). The clinical and electrophysiological characteristics and outcomes of LAT without AF have not been investigated. This study sought to determine the long-term ablation outcomes and predictors of recurrence of isolated LAT. Methods This is a single-center study of consecutive patients with isolated LAT. Atrial arrhythmia recurrence was determined from follow-up records of patients who underwent LAT ablation from 2008 to 2017. Clinical and electrophysiologic characteristics associated with atrial arrhythmia recurrence were identified. Results A total of 50 patients (53 ± 19 years, 46% male) with 59 LAT (1.16 ± 0.47 per patient) were enrolled. Over a mean follow-up of 37 ± 33 months, atrial arrhythmia recurrence occurred in 22 (44%) patients, 11 with atrial tachycardia (AT) only, five with AF only, and six with concurrent AT and AF. The incidence of pulmonary vein (PV) origins increased significantly in the repeat procedure (P = 0.036). Multivariate analysis identified left ventricular ejection fraction (LVEF) as the only predictor of any atrial arrhythmia recurrence and LAT recurrence, while smoking and identified macroreentrant LAT in the index procedure predicted AF recurrence. Conclusion This study demonstrated a higher rate of atrial arrhythmia recurrence, including AF, among patients with initially isolated LAT. A lower LVEF predicted any atrial arrhythmia and LAT recurrence, whereas smoking and index macroreentrant AT mechanism predicted long-term AF. PV ATs were frequently observed in recurrent patients irrespective of index procedure origin.

Diabetes-associated cardiac fibrosis is a severe cardiovascular complication. Momordicine I, a bioactive triterpenoid isolated from bitter melon, has been demonstrated to have antidiabetic properties. This study investigated the effects of momordicine I on high-glucose-induced cardiac fibroblast activation. Rat cardiac fibroblasts were cultured in a high-glucose (25 mM) medium in the absence or presence of momordicine I, and the changes in collagen synthesis, transforming growth factor-β1 (TGF-β1) production, and related signaling molecules were assessed. Increased oxidative stress plays a critical role in the development of high-glucose-induced cardiac fibrosis; we further explored momordicine I’s antioxidant activity and its effect on fibroblasts. Our data revealed that a high-glucose condition promoted fibroblast proliferation and collagen synthesis and these effects were abolished by momordicine I (0.3 and 1 μM) pretreatment. Furthermore, the inhibitory effect of momordicine I on high-glucose-induced fibroblast activation may be associated with its activation of nuclear factor erythroid 2-related factor 2 (Nrf2) and the inhibition of reactive oxygen species formation, TGF-β1 production, and Smad2/3 phosphorylation. The addition of brusatol (a selective inhibitor of Nrf2) or Nrf2 siRNA significantly abolished the inhibitory effect of momordicine I on fibroblast activation. Our findings revealed that the antifibrotic effect of momordicine I was mediated, at least partially, by the inhibition of the TGF-β1/Smad pathway, fibroblast proliferation, and collagen synthesis through Nrf2 activation. Thus, this work provides crucial insights into the molecular pathways for the clinical application of momordicine I for treating diabetes-associated cardiac fibrosis.

Moderate coffee consumption is inversely associated with cardiovascular disease mortality; however, mechanisms underlying this causal effect remain unclear. Cafestol, a diterpene found in coffee, has various properties, including an anti-inflammatory property. This study investigated the effect of cafestol on cyclic-strain-induced inflammatory molecule secretion in vascular endothelial cells. Cells were cultured under static or cyclic strain conditions, and the secretion of inflammatory molecules was determined using enzyme-linked immunosorbent assay. The effects of cafestol on mitogen-activated protein kinases (MAPK), heme oxygenase-1 (HO-1), and sirtuin 1 (Sirt1) signaling pathways were examined using Western blotting and specific inhibitors. Cafestol attenuated cyclic-strain-stimulated intercellular adhesion molecule-1 (ICAM-1), monocyte chemoattractant protein- (MCP-) 1, and interleukin- (IL-) 8 secretion. Cafestol inhibited the cyclic-strain-induced phosphorylation of extracellular signal-regulated kinase and p38 MAPK. By contrast, cafestol upregulated cyclic-strain-induced HO-1 and Sirt1 expression. The addition of zinc protoporphyrin IX, sirtinol, or Sirt1 silencing (transfected with Sirt1 siRNA) significantly attenuated cafestol-mediated modulatory effects on cyclic-strain-stimulated ICAM-1, MCP-1, and IL-8 secretion. This is the first study to report that cafestol inhibited cyclic-strain-induced inflammatory molecule secretion, possibly through the activation of HO-1 and Sirt1 in endothelial cells. The results provide valuable insights into molecular pathways that may contribute to the effects of cafestol.

A selenophene-modified PTB7, PBDTSe-TT, is reported. The structure adjustment carried out by alkylselenophene substitution on the BDT building block is shown to slightly affect the polymer’s electronic property, and an enlarged VOC of the resulting photovoltaic device is observed. More importantly, the PBDTSe-TT:PC71BM bulk-heterojunction thin film morphology can be optimized through this modification. As a result, an efficient PCE of 8.8% is achieved without using any solvent additive or special interfacial layer. In addition, the PBDTSe-TT-based device is relatively stable under thermal stress, making it a good candidate for fabricating stacking cells. Finally, a ∼10% PCE tandem device is demonstrated by using identical PBDTSe-TT:PC71BM subcells.

Cafestol, a diterpene molecule found in the berries of Coffea arabica L. (Rubiaceae), has been shown to exercise anti-angiogenic and anti-tumorigenic effects. However, cafestol's cellular mechanism has yet to be fully investigated. We previously demonstrated that urotensin II enhanced interleukin-8 secretion by endothelial cells, thereby increasing endothelial cell proliferation. Urotensin II may also participate in angiogenesis and tumor infiltration by macrophages. However, the effects of cafestol on urotensin II-induced interleukin-8 expression and cellular proliferation have not been determined. Here, we showed that pretreatment with cafestol inhibited urotensin II-stimulated endothelial cell proliferation. Further experiments demonstrated that cafestol increased translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) and expression of enhanced heme oxygenase-1. Moreover, cafestol inhibited expression of urotensin II-induced interleukin-8. Cafestol's inhibitory effects on interleukin-8 expression and cellular proliferation induced by urotensin II were significantly abrogated by heme oxygenase-1 silencing, suggesting it may be involved in mediating the effects of cafestol. This study reports that cafestol inhibits urotensin II-induced interleukin-8 expression and cell proliferation via Nrf2/heme oxygenase-1-dependent mechanism in endothelial cells. These findings provide novel insight into the signaling pathways that may be important in mediating the effects of cafestol.

Creating long-term memory (LTM) requires new protein synthesis to stabilize learning-induced synaptic changes in the brain. In the fruit fly, Drosophila melanogaster, aversive olfactory learning forms several phases of labile memory to associate an odor with coincident punishment in the mushroom body (MB). It remains unclear how the brain consolidates early labile memory into LTM. Here, we survey 183 Gal4 lines containing almost all 21 distinct types of MB output neurons (MBONs) and show that sequential synthesis of learning-induced proteins occurs at three types of MBONs. Downregulation of oo18 RNA-binding proteins (ORBs) in any of these MBONs impaired LTM. And, neurotransmission outputs from these MBONs are all required during LTM retrieval. Together, these results suggest an LTM consolidation model in which transient neural activities of early labile memory in the MB are consolidated into stable LTM at a few postsynaptic MBONs through sequential ORB-regulated local protein synthesis.

1, 8-Diiodooctane (DIO) has been known for its role of improving the polymer morphology and enhancing performance of polymer bulk heterojunction (BHJ) solar cell. In this work, the impedance spectroscopy was used to investigate the interface of poly(4,8-bis-alkyloxybenzo(1,2-b:4,5-b′)dithiophene-2,6-diyl-alt- (alkyl thieno(3,4-b) thiophene-2-carboxylate)-2,6-diyl) (PBDTTT-C):PC 70 BM in BHJ with DIO as additive. Based on our results, we were able to simulate the device into an equivalent circuit model, which allows us to conveniently analyze the organic/organic interfacial contact in the organic photovoltaic (OPV) device. Thus, we demonstrate that the impedance spectroscopy can an effective approach in characterizing the donor/acceptor interfaces, such that a direct correlation can be established between the morphology and the device performance of BHJ devices.

Tandem solar cells have the potential to improve photon conversion efficiencies (PCEs) beyond the limits of single-junction devices. In this study, a triple-junction tandem design is demonstrated by employing three distinct organic donor materials having bandgap energies ranging from 1.4 to 1.9 eV. Through optical modeling, balanced photon absorption rates are achieved and, thereby, the photo-currents are matched among the three subcells. Accordingly, an efficient triple-junction tandem organic solar cell can exhibit a record-high PCE of 11.5%.

The same two straight mortise-tennon joints in the base of melon-column (SJ for short) and penetrated mortise-tennon joints (PJ for short) were made with related rules. Relations of moment-rotation, length of the tenon pulled out-rotation and failure modes were got through monotonic loading test. Experimental study showed the main damage type of SJ was pulling out, while two damage types of PJ were bending damage and transverse tearing failure respectively. When under the action of bending moment, the resisting torque of SJ was synthesized by vertical load of columns, while that of PJ was mainly synthesized by local compresssive stress and friction on upper and lower surface of the tennon. In addition, the pulling size of tennons was associated with the heigth of tenon and relative rotation of beam and column.

Perovskite compounds have attracted recently great attention in photovoltaic research. The devices are typically fabricated using condensed or mesoporous TiO2 as the electron transport layer and 2,2'7,7'-tetrakis-(N,N-dip-methoxyphenylamine)9,9'-spirobifluorene as the hole transport layer. However, the high-temperature processing (450 °C) requirement of the TiO2 layer could hinder the widespread adoption of the technology. In this report, we adopted a low-temperature processing technique to attain high-efficiency devices in both rigid and flexible substrates, using device structure substrate/ITO/PEDOT:PSS/CH(3)NH(3)PbI(3-x)Cl(x)/PCBM/Al, where PEDOT:PSS and PCBM are used as hole and electron transport layers, respectively. Mixed halide perovskite, CH(3)NH(3)PbI(3-x)Cl(x), was used due to its long carrier lifetime and good electrical properties. All of these layers are solution-processed under 120 °C. Based on the proposed device structure, power conversion efficiency (PCE) of 11.5% is obtained in rigid substrates (glass/ITO), and a 9.2% PCE is achieved for a polyethylene terephthalate/ITO flexible substrate.

Nicorandil is an adenosine triphosphate-sensitive potassium channel opener with additional antioxidant properties. Doxorubicin (DOX) is an anticancer drug that exerts oxidation-mediated adverse cardiovascular effects. This study examined the effects of nicorandil on DOX-induced cytotoxicity in human umbilical vein endothelial cells (HUVECs) and underlying intracellular signaling mechanisms. Cultured HUVECs were pretreated with nicorandil (0.1, 0.3, 1, 3, and 10 μM) for 12 h and then treated with DOX (1 μM) for 24 h. Cell viability and cytotoxicity were measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and lactate dehydrogenase assays, respectively. Cell apoptosis was examined using a caspase-3 activity assay, and DNA fragmentation was detected through TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling) staining. Western blot analysis was conducted to determine the related protein expression. DOX markedly increased reactive oxygen species production, p53 expression, caspase-3 activity, cleaved caspase-3 levels, and TUNEL-positive cell numbers but reduced Bcl-2 expression and intracellular antioxidant enzyme levels; these effects were effectively antagonized through nicorandil (3 μM, 12 h) pretreatment, which resulted in HUVECs being protected from DOX-induced apoptosis. Activating transcription factor 3 (ATF3), a stress-induced transcription factor, was induced by nicorandil (3 μM). Furthermore, nicorandil (3 μM) enhanced nuclear factor erythroid 2–related factor 2 (Nrf2) translocation and heme oxygenase-1 (HO-1) expression. ATF3 short interfering RNA significantly attenuated nicorandil-mediated Nrf2 translocation, HO-1 expression, and inhibitory effects on DOX-stimulated reactive oxygen species production and cell apoptosis. In summary, nicorandil may protect HUVECs from DOX-induced apoptosis, in part through ATF3-mediated Nrf2/HO-1 signaling pathways, which potentially protect the vessels from severe DOX toxicity.

Rationale: Acute myocardial infarction (AMI) secondary to spontaneous coronary artery dissection (SCAD) is a rare condition. SCAD can be underdiagnosed on a coronary angiography (CAG). Therefore, the application of intravascular imaging including intravascular ultrasound (IVUS) and optical coherence tomography (OCT) is crucial for ensuring an accurate diagnosis and treatment. Patients concerns: A 72-year-old woman had an evolving AMI with ST elevation in the inferior leads (II, III, and aVF). Diagnoses: An emergent CAG showed that a double lumen had developed in the middle portion of the left circumflex artery. An IVUS examination revealed a coronary artery dissection and intramural hematoma. Interventions: First, the patient was treated with conservative management. We later placed a stent in response to the progression of the intramural hematoma observed during the IVUS follow-up. Outcomes: The patient remained symptom free after discharge. CAG with OCT at the 1-year follow-up after stent implantation showed in-stent restenosis with dissection flap with residual false lumen at the proximal site of stent. We treated this lesion with another stent. Lessons: From this case, we learned that in patients with AMI, SCAD should be considered as a possible diagnosis and that intravascular imaging tool can successfully guide clinical decision making and the treatment strategies.

High intrinsic carrier mobility and excellent transparency at visible wavelengths make stannic oxide (SnO2) a material of interest for a variety of optoelectronic applications. Here, we demonstrate a solvothermal route to stabilize gelled dispersions of tin oxide nanoparticles with diameters in the range of 2–4 nm. Small particle dimensions ultimately allow for the deposition of smooth thin films with all of the useful properties that can be expected from this material system. The structural and morphological properties of the deposited films are investigated, and they are demonstrated as an electron collection layer in polymer-based organic photovoltaic cells with promising power conversion efficiencies.

SummaryHow the brain perceives sensory information and generates meaningful behavior depends critically on its underlying circuitry. The protocerebral bridge (PB) is a major part of the insect central complex (CX), a premotor center that may be analogous to the human basal ganglia. Here, by deconstructing hundreds of PB single neurons and reconstructing them into a common three-dimensional framework, we have constructed a comprehensive map of PB circuits with labeled polarity and predicted directions of information flow. Our analysis reveals a highly ordered information processing system that involves directed information flow among CX subunits through 194 distinct PB neuron types. Circuitry properties such as mirroring, convergence, divergence, tiling, reverberation, and parallel signal propagation were observed; their functional and evolutional significance is discussed. This layout of PB neuronal circuitry may provide guidelines for further investigations on transformation of sensory (e.g., visual) input into locomotor commands in fly brains.

We describe the detailed synthesis and characterization of an electron-rich building block, dithienopyran (DTP), and its application as a donor unit in low-bandgap conjugated polymers. The electron-donating property of the DTP unit was found to be the strongest among the most frequently used donor units such as benzodithiophene (BDT) or cyclopentadithiophene (CPDT) units. When the DTP unit was polymerized with the strongly electron-deficient difluorobenzothiadiazole (DFBT) unit, a regiorandom polymer (PDTP–DFBT, bandgap = 1.38 eV) was obtained. For comparison with the DTP unit, polymers containing alternating benzodithiophene (BDT) or cyclopentadithiophene (CPDT) units and the DFBT unit were synthesized (PBDT–DFBT and PCPDT–DFBT). We found that the DTP based polymer PDTP–DFBT shows significantly improved solubility and processability compared to the BDT or CPDT based polymers. Consequently, very high molecular weight and soluble PDTP–DFBT can be obtained with less bulky side chains. Interestingly, PDTP–DF...

In order to realize the online fault diagnosis of freight rolling bearing without disassembling, a simulation test platform was established in the laboratory and acoustic emission (AE) sensor of AE-98/R15 was used to acquire AE signals. According to the signal characteristics, MATLAB software was used to analyze features of signals with wavelet packet and to recognize bearing state with probabilistic neural network. These methods have a very good effect for fault diagnosis in the laboratory. The innovation of this paper is that the above methods are effectively used for fault diagnosis and provide a feasible scheme for field application.

Purpose The risk of hemorrhagic stroke in patients with atrial fibrillation (AF) is low but the consequences of its occurrence are extremely severe. In this study, we investigated the association of influenza vaccination with the risk of hemorrhagic stroke to develop an efficient strategy for reducing this risk in patients with AF. Methods In this study, data were retrieved from the Taiwan National Health Insurance Research Database. The study cohort comprised all patients who received a diagnosis of AF ( n =14,454) before January 1, 2005 (index date) and were followed until December 31, 2012. Propensity scores were calculated using a logistic regression model to determine the effects of vaccination by accounting for covariates that predict receiving the intervention (vaccine). A time-dependent Cox proportional hazard model was used to calculate the hazard ratios (HRs) for hemorrhagic stroke in vaccinated and unvaccinated patients with AF. Results The study population comprised 6570 patients who did (2547 [38.77%]) and did not receive (4023 [61.23%]) influenza vaccination. The adjusted HRs (aHRs) for hemorrhagic stroke were lower in the vaccinated patients than in the unvaccinated patients (influenza season, noninfluenza season, and all seasons: aHRs=0.97 [0.59–1.60], 0.51 [0.30–0.87], and 0.72 [0.50–1.03], respectively). Conclusions Influenza vaccination exerts dose–response and synergistic protective effects against hemorrhagic stroke in patients with AF who have a high risk of hemorrhagic stroke (i.e., male sex, age≥75years, Charlson comorbidity index ≥3, and hypertension) and reduces the incidence of hemorrhagic stroke.

In this study we developed an approach to improve the characteristics of photopolymers for holographic data storage. Through codoping different compounds, N,N-dimethyl-4-nitroaniline (DMNA) and zinc methylacrylate (Zn(MA)2), into 9,10-phenanthrenequinone (PQ) doped poly(methyl methacrylate) (PMMA), the diffraction efficiency and the value of dynamic range (M#) have been progressed. We enhanced the diffraction efficiency (from 36.1 to 86.2%) and the dynamic range (M#, from 2.9 to 10.7) of PQ-doped PMMA through codoping with DMNA and Zn(MA)2. Using mass spectrometry and X-ray photoelectron spectroscopy, we investigated the mechanism behind the improvements in optical storage induced by the presence of Zn(MA)2 and DMNA in PMMA/PQ. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers

Initial experimental work has demonstrated that x-ray bombardment of organic-based photocells (specifically P3HT:PCBM-based) leads to a reduction in the open-circuit voltage (Voc) without apparent change in the carrier relaxation time. The variation of Voc was suggested to be due to the injection and trapping of holes near the anode, which resulted in a decrease in the built-in potential. We have extended the experimental measurements to higher total dose (~1300 krad(SiO2)). Using standard inorganic modeling tools, a device model of the organic cell has been developed and predictions made. These predictions have been compared to the results of the previous and new experimental measurements and they demonstrate reasonable agreement between the two, thereby supporting the initial charge buildup hypothesis. Questions about the origin and behavior of the photo-carrier relaxation arise.

IO N Organic photovoltaic (OPV) devices provide an opportunity to utilize the solar energy effi ciently while maintaining low cost. [ 1 ] To harvest a greater part of the solar spectrum, lowering the energy bandgap of the active material is a major task for materials scientists. The design and synthesis of low-bandgap (LBG) conjugated polymers for use as electron donor materials for bulk heterojuction (BHJ) polymer solar cell (PSC) applications have attracted remarkable attention during the last decade. [ 2 ] The reasons for pursuing LBG polymers include: 1) The Shockley-Quiesser equation indicates a bandgap of around 1.4 eV is ideal for a single junction solar cell device. [ 3 ]

Visibly transparent photovoltaic devices can open photovoltaic applications in many areas, such as building-integrated photovoltaics or integrated photovoltaic chargers for portable electronics. We demonstrate high-performance, visibly transparent polymer solar cells fabricated via solution processing. The photoactive layer of these visibly transparent polymer solar cells harvests solar energy from the near-infrared region while being less sensitive to visible photons. The top transparent electrode employs a highly transparent silver nanowire-metal oxide composite conducting film, which is coated through mild solution processes. With this combination, we have achieved 4% power-conversion efficiency for solution-processed and visibly transparent polymer solar cells. The optimized devices have a maximum transparency of 66% at 550 nm.

A simple method is demonstrated to improve the film-forming properties and air stability of a conjugated polyelectrolyte (CPE) without complicated synthesis of new chemical structures. An anionic surfactant, sodium dodecybenzenesulfonate (SDS), is mixed with cationic CPEs. The electrostatic attraction between these two oppositely-charged materials provides the driving force to form a stable CPE-surfactant complex. Compared with a pure CPE, this electrostatic complex is not only compatible with highly hydrophobic bulk-heterojunction (BHJ) films, e.g. poly(3-hexylthiophene):[6,6]-phenyl C61 butyric acid methyl ester (P3HT:PCBM), but also works well with other low bandgap polymer-based BHJ films. Using this complex as a cathode interface layer, a high power conversion efficiency of 4% can be obtained in P3HT:PCBM solar cells together with improved stability in air. Moreover, ∼20% performance enhancement can also be achieved when the complex is used as an interlayer to replace calcium metal for low bandgap polymer-based BHJ systems.

Researchers demonstrate that PBDTT-DPP, a semiconducting polymer with a low bandgap of 1.44 eV, allows tandem polymer solar cells to reach power conversion efficiencies of around 8.6%.

We demonstrated plasmonic effects in an inverted tandem polymer solar cell configuration by blending Au nanoparticles (NPs) into the interconnecting layer (ICL) that connects two subcells. Experimental results showed this plasmonic enhanced ICL improves both the top and bottom subcells' efficiency simultaneously by enhancing optical absorption. The presence of Au NPs did not cause electrical characteristics to degrade within the tandem cell. As a result, a 20% improvement of power conversion efficiency has been attained by the light concentration of Au NPs via plasmonic near-field enhancement. The simulated near-field distribution and experimental Raman scattering investigation support our results of plasmonic induced enhancement in solar cell performance. Our finding shows a great potential of incorporating the plasmonic effect with conventional device structure in achieving highly efficient polymer solar cells.

In this work, a multilayer structure, PEDOT:PSS/insulator/PEDOT:PSS (CIC), was designed and used as the anode in a polymer solar cell (PSC) to enhance the efficiency at low annealing temperature. The efficiency for PSC with CIC multilayers could increase around 22% as compared to the reference cell. The internal electrical field enhancement due to the effective work function increase by CIC multilayer was assumed and responded to efficiency enhancement. The work function of the multilayer anode structure was explored by an electrostatic force microscopy (EFM) analysis. The EFM result shows that the surface potential of PEDPT:PSS in CIC structure is around 0.6 V higher than PEDOT:PSS in reference structure, indicating a higher work function for PEDOT:PSS in multilayer structure. By the input photon-to-current conversion efficiency (IPCE) study, the major enhancement in photocurrent occurred at solar spectrum range of 400–650 nm. Further applied to plastic substrate, the PSC exhibits 9.2% enhancement in efficiency.

Thin-film solar cells made with amorphous silicon (a-Si:H) or organic semiconductors are considered as promising renewable energy sources due to their low manufacturing cost and light weight. However, the efficiency of single-junction a-Si:H or organic solar cells is typically10%, insufficient for achieving grid parity. Here we demonstrate an efficient double-junction photovoltaic cell by employing an a-Si:H film as a front sub-cell and a low band gap polymer:fullerene blend film as a back cell on planar glass substrates. Monolithic integration of 6.0% efficienct a-Si:H and 7.5% efficient polymer:fullerene blend solar cells results in a power conversion efficiency of 10.5%. Such high-efficiency thin-film tandem cells can be achieved by optical management and interface engineering of fully optimized high-performance front and back cells without sacrificing photovoltaic performance in both cells.

The power conversion efficiency (PCE) of a DPP-based polymer solar cell is significantly improved by using DIO or DCB as processing additives. The discovery that DCB outperforms DIO with a significantly wider solvent mixture operation window suggests different optimization mechanisms. Although both solvent mixture systems involve double aggregation processes, including a similar solution-to-film aggregation, however, two distinct solution-stage aggregations are observed: relatively amorphous polymer aggregates form in the CF-DIO solution, while more crystalline polymer aggregates form in CF-DCB solution.

A two-dimensional conjugated small molecule (SMPV1) was designed and synthesized for high performance solution-processed organic solar cells. This study explores the photovoltaic properties of this molecule as a donor, with a fullerene derivative as an acceptor, using solution processing in single junction and double junction tandem solar cells. The single junction solar cells based on SMPV1 exhibited a certified power conversion efficiency of 8.02% under AM 1.5 G irradiation (100 mW cm(-2)). A homo-tandem solar cell based on SMPV1 was constructed with a novel interlayer (or tunnel junction) consisting of bilayer conjugated polyelectrolyte, demonstrating an unprecedented PCE of 10.1%. These results strongly suggest solution-processed small molecular materials are excellent candidates for organic solar cells.

A considerable amount of studies have been conducted to investigate the interactions of biological fluids with nanoparticle surfaces, which exhibit a high affinity for proteins and particles. However, the mechanisms underlying these interactions have not been elucidated, particularly as they relate to human health. Using bovine serum albumin (BSA) and mice bronchoalveolar lavage fluid (BALF) as models for protein–particle conjugates, we characterized the physicochemical modifications of carbon blacks (CB) with 23 nm or 65 nm in diameter after protein treatment. Adsorbed BALF-containing proteins were quantified and identified by pathways, biological analyses and protein classification. Significant modifications of the physicochemistry of CB were induced by the addition of BSA. Enzyme modulators and hydrolase predominately interacted with CB, with protein-to-CB interactions that were associated with the coagulation pathways. Additionally, our results revealed that an acute-phase response could be activated by these proteins. With regard to human health, the present study revealed that the CB can react with proteins (∼55 kDa and 70 kDa) after inhalation and may modify the functional structures of lung proteins, leading to the activation of acute-inflammatory responses in the lungs.

Memory is initially labile and gradually consolidated over time through new protein synthesis into a long-lasting stable form. Studies of odor-shock associative learning in Drosophila have established the mushroom body (MB) as a key brain structure involved in olfactory long-term memory (LTM) formation. Exactly how early neural activity encoded in thousands of MB neurons is consolidated into protein-synthesis–dependent LTM remains unclear. Here, several independent lines of evidence indicate that changes in two MB vertical lobe V3 (MB-V3) extrinsic neurons are required and contribute to an extended neural network involved in olfactory LTM: ( i ) inhibiting protein synthesis in MB-V3 neurons impairs LTM; ( ii ) MB-V3 neurons show enhanced neural activity after spaced but not massed training; ( iii ) MB-V3 dendrites, synapsing with hundreds of MB α/β neurons, exhibit dramatic structural plasticity after removal of olfactory inputs; ( iv ) neurotransmission from MB-V3 neurons is necessary for LTM retrieval; and ( v ) RNAi-mediated down-regulation of oo18 RNA-binding protein (involved in local regulation of protein translation) in MB-V3 neurons impairs LTM. Our results suggest a model of long-term memory formation that includes a systems-level consolidation process, wherein an early, labile olfactory memory represented by neural activity in a sparse subset of MB neurons is converted into a stable LTM through protein synthesis in dendrites of MB-V3 neurons synapsed onto MB α lobes.

Conjugated acceptor-donor-acceptor small molecules using different electron linkers are designed, synthesized, and used in organic solar cells. All of these small molecules show high photoconversion efficiencies (PCEs), ranging from 3.18-6.15% under simulated AM 1.5G condition. A maximum PCE of 6.15% combined with a high Voc of 0.85 V, a Jsc of 10.79 mA cm(-2) and a notable FF of 67.1% are achieved with T3/PC71 BM blend based devices using polydimethylsiloxane as additive.

Polymer tandem solar cells with 10.2% power conversion efficiency are demonstrated via stacking two PDTP-DFBT:PC₇₁ BM bulk heterojunctions, connected by MoO₃/PEDOT:PSS/ZnO as an interconnecting layer. The tandem solar cells increase the power conversion efficiency of the PDTP-DFBT:PC₇₁ BM system from 8.1% to 10.2%, successfully demonstrating polymer tandem solar cells with identical sub-cells of double-digit efficiency.

An effective way to improve polymer solar cell efficiency is to use a tandem structure, as a broader part of the spectrum of solar radiation is used and the thermalization loss of photon energy is minimized. In the past, the lack of high-performance low-bandgap polymers was the major limiting factor for achieving high-performance tandem solar cell. Here we report the development of a high-performance low bandgap polymer (bandgap 60% and spectral response that extends to 900 nm, with a power conversion efficiency of 7.9%. The polymer enables a solution processed tandem solar cell with certified 10.6% power conversion efficiency under standard reporting conditions (25 °C, 1,000 Wm−2, IEC 60904-3 global), which is the first certified polymer solar cell efficiency over 10%., Tandem solar cell structures combine high- and low-bandgap materials, allowing a broader spectral absorption of solar radiation. The authors report the synthesis of a high performance low-bandgap polymer which enables fabrication of a tandem solar cell with a certified power conversion efficiency of 10.6%.

The tandem solar cell architecture is an effective way to harvest a broader part of the solar spectrum and make better use of the photonic energy than the single junction cell. Here, we present the design, synthesis, and characterization of a series of new low bandgap polymers specifically for tandem polymer solar cells. These polymers have a backbone based on the benzodithiophene (BDT) and diketopyrrolopyrrole (DPP) units. Alkylthienyl and alkylphenyl moieties were incorporated onto the BDT unit to form BDTT and BDTP units, respectively; a furan moiety was incorporated onto the DPP unit in place of thiophene to form the FDPP unit. Low bandgap polymers (bandgap = 1.4-1.5 eV) were prepared using BDTT, BDTP, FDPP, and DPP units via Stille-coupling polymerization. These structural modifications lead to polymers with different optical, electrochemical, and electronic properties. Single junction solar cells were fabricated, and the polymer:PC(71)BM active layer morphology was optimized by adding 1,8-diiodooctane (DIO) as an additive. In the single-layer photovoltaic device, they showed power conversion efficiencies (PCEs) of 3-6%. When the polymers were applied in tandem solar cells, PCEs over 8% were reached, demonstrating their great potential for high efficiency tandem polymer solar cells.

Challenging the Mushroom Bodies Early memory is labile and is gradually consolidated over time into long-lasting, stable memory. In several species, including mammals, memory consolidation depends on protein synthesis. In Drosophila , long-term memory is produced by spaced repetitive training, which induces cyclic adenosine monophosphate (cAMP)–response element–binding protein (CREB)–dependent gene transcription and de novo protein synthesis. Using a large number of genetic tools, Chen et al. (p. 678 ; see the Perspective by Dubnau ) localized this CREB-dependent induction of de novo protein synthesis to two dorsal-anterior-lateral neurons in the adult brain. Importantly, protein synthesis was not required within the mushroom bodies, which are usually considered to be the site of associative learning and memory in insects.

Silver nanowire (AgNW) networks are promising candidates to replace indium-tin-oxide (ITO) as transparent conductors. However, complicated treatments are often required to fuse crossed AgNWs to achieve low resistance and good substrate adhesion. In this work, we demonstrate a simple and effective solution method to achieve highly conductive AgNW composite films with excellent optical transparency and mechanical properties. These properties are achieved via sequentially applying TiO(2) sol-gel and PEDOT:PSS solution to treat the AgNW film. TiO(2) solution volume shrinkage and the capillary force induced by solvent evaporation result in tighter contact between crossed AgNWs and improved film conductivity. The PEDOT:PSS coating acts as a protecting layer to achieve strong adhesion. Organic photovoltaic devices based on the AgNW-TiO(2)-PEDOT:PSS transparent conductor have shown comparable performance to those based on commercial ITO substrates.