Expression of concern: Versatile plasmonic-effects at the interface of inverted perovskite solar cells.

Expression of concern for 'Versatile plasmonic-effects at the interface of inverted perovskite solar cells' by Ahmed Esmail Shalan, et al., Nanoscale, 2017, 9, 1229-1236, https://doi.org/10.1039/C6NR06741G.

Slow Passivation and Inverted Hysteresis for Hybrid Tin Perovskite Solar Cells Attaining 13.5% via Sequential Deposition.

Herein, we report a sequential deposition procedure to passivate the surface of a hybrid mixed cationic tin perovskite (E1G20) with phenylhydrazinium thiocyanate (PHSCN) dissolved in trifluoroethanol solvent. The photoluminescence lifetime of the PHSCN film was enhanced by a factor of 6, while the charge-extraction rate from perovskite to C60 layer was enhanced by a factor of 2.5, in comparison to those of the E1G20 film. A slow surface passivation was observed; the performance of the PHSCN device improved upon increasing the storage period to attain an efficiency of 13.5% for a current-voltage scan in the forward bias direction. An inverted effect of hysteresis was observed in that the efficiency of the forward scan was greater than that of the reverse scan. An ion-migration model as a result of the effect of the phenylhydrazinium surface passivation is proposed to account for the observed phenomena. The device was stable upon shelf storage in a glovebox for 3000 h.

Serum soluble TWEAK levels in severe traumatic brain injury and its prognostic significance.

BACKGROUND: Severe traumatic brain injury (sTBI) is characterized by a high mortality. Tumor necrosis factor-like weak inducer of apoptosis (TWEAK) participates in inflammation. We determined serum soluble TWEAK (sTWEAK) levels with respect to its prognostic ability. METHODS: This was a single-center prospective, observational study that was performed from December 2014 to December 2017. A total of 114 sTBI patients who met the inclusion criteria and 114 randomly selected healthy controls were included in the study. Serum sTWEAK levels were gauged. Patients were followed-up until death or completion of 6 months. Poor outcome was referred to as Glasgow outcome scale score of 1-3. RESULTS: In comparison with controls, patients displayed predominantly higher serum sTWEAK levels. Serum sTWEAK levels were strongly correlated with Glasgow coma scale scores and serum C-reactive protein levels. 32 patients (28.1%) died and 60 patients (52.6%) suffered from a poor outcome. Receiver operating characteristic curve analysis clearly showed that serum sTWEAK levels had substantially high predictive performance for 6-month mortality and poor outcome. Serum sTWEAK emerged as an independent predictor for 6-month mortality, overall survival and poor outcome. CONCLUSIONS: Raised serum sTWEAK levels are closely related to increasing inflammatory response, elevated trauma severity and worse clinical outcome after sTBI.

Research progress on human genes involved in the pathogenesis of glaucoma (Review).

Glaucoma is the leading cause of irreversible blindness globally. It is known that the incidence of glaucoma is closely associated with inheritance. A large number of studies have suggested that genetic factors are involved in the occurrence and development of glaucoma, and even affect the drug sensitivity and prognosis of glaucoma. In the present review, 22 loci of glaucoma are presented, including the relevant genes (myocilin, interleukin 20 receptor subunit B, optineurin, ankyrin repeat­ and SOCS box­containing protein 10, WD repeat­containing protein 36, EGF­containing fibulin­like extracellular matrix protein 1, neurotrophin 4, TANK­binding kinase 1, cytochrome P450 subfamily I polypeptide 1, latent transforming growth factor ß binding protein 2 and TEK tyrosine kinase endothelial) and 74 other genes (including toll­like receptor 4, sine oculis homeobox Drosophila homolog of 1, doublecortin­like kinase 1, RE repeats­encoding gene, retinitis pigmentosa GTPase regulator­interacting protein, lysyl oxidase­like protein 1, heat­shock 70­kDa protein 1A, baculoviral IAP repeat­containing protein 6, 5,10­methylenetetrahydrofolate reductase and nitric oxide synthase 3 and nanophthalmos 1) that are more closely associated with glaucoma. The pathogenesis of these glaucoma­associated genes, glaucomatous genetics and genetic approaches, as well as glaucomatous risk factors, including increasing age, glaucoma family history, high myopia, diabetes, ocular trauma, smoking, intraocular pressure increase and/or fluctuation were also discussed.

Versatile plasmonic-effects at the interface of inverted perovskite solar cells.

Plasmonics is a highly promising approach to enhancing the light-harvesting properties of hybrid organic/inorganic perovskite solar cells. In the present work, our cells have a p-i-n inverted planar structure. An ultrathin NiO film with two different thicknesses of 5 and 10 nm prepared by a pulsed laser deposition process on an ITO substrate with a faceted and furrowed surface enabled the formation of a continuous and compact layer of well-crystallized CH3NH3PbI3via an anti-solvent chlorobenzene process. The coverage mechanism of the NiO film on the ITO was clearly demonstrated through the J-V and external quantum efficiency (EQE) curves. Moreover, the results demonstrated that the gold nanoislands (Au NIs) increased the power conversion efficiency to 5.1%, almost double that of the samples without Au NIs. This result is due to the excitation of surface plasmons, which is characterized by strong scattering and enhancement of the electric field in the vicinity of the Au NIs loaded at the interface between the NiO and perovskite films. Additionally, we observed an enhancement of the EQE at wavelengths shorter than the plasmon resonance peak. In the current state, we speculate that the plasmoelectric potential effect is considered to be a good explanation of the photocurrent enhancement at the off-resonance region. Our work provides good guidance for the design and fabrication of solar-energy-related devices employing NiO electrodes and plasmonic Au NIs.

Cobalt Oxide (CoOx) as an Efficient Hole-Extracting Layer for High-Performance Inverted Planar Perovskite Solar Cells.

CoOx is a promising hole-extracting layer (HEL) for inverted planar perovskite solar cells with device configuration ITO/CoOx/CH3NH3PbI3/PCBM/Ag. The devices fabricated according to a simple solution procedure showed the best photovoltaic performance attaining power conversion efficiency (PCE) of 14.5% under AM 1.5 G 1 sun irradiation, which is significantly superior to those of materials fabricated with a traditional HEL such as PEDOT:PSS (12.2%), NiOx (10.2%), and CuOx (9.4%) under the same experimental conditions. We characterized the chemical compositions with XPS, crystal structures with XRD, and film morphology with SEM/AFM techniques. Photoluminescence (PL) spectra and the corresponding PL decays for perovskite deposited on varied HEL films were recorded to obtain the hole-extracting characteristics, for which the hole-extracting times show the order CoOx (2.8 ns) < PEDOT:PSS (17.5 ns) < NiOx (22.8 ns) < CuOx (208.5 ns), consistent with the trend of their photovoltaic performances. The reproducibility and enduring stability of those devices were examined to show the outstanding long-term stability of the devices made of metal oxide HEL, for which the CoOx device retained PCE ≈ 12% for over 1000 h.

Novel porphyrin-preparation, characterization, and applications in solar energy conversion.

Porphyrins have been demonstrated as one of the most efficient sensitizers in dye-sensitized solar cells (DSSC). Herein, we investigated a series of porphyrin sensitizers functionalized with various π-spacers, such as phenyl for LD14, thiophene for LW4, thiophene-phenyl for LW5, and 2,1,3-benzothiadiazole (BTD)-phenyl for LW24. Photo-physical investigation by means of time-resolved fluorescence and nanosecond transient absorption spectroscopy revealed an accelerated inner charge transfer in porphyrins containing the BTD-phenyl π-spacer. Implementation of an auxiliary electron-deficient BTD unit to the porphyrin spacer also results in a broad light-harvesting ability extending up to 840 nm, contributing to an enhanced charge transfer character from the porphyrin ring to the anchoring group. When utilized as a sensitizer in DSSCs, the LW24 device achieved a power conversion efficiency of 9.2%, higher than those based on LD14 or LW5 porphyrins (PCE 9.0% or 8.2%, respectively) but lower than that of the LW4 device (PCE 9.5%). Measurements of transient photovoltage decays demonstrate that the LW24 device features the up-shifted potential band edge of the conduction band of TiO2, but involves serious charge recombination in the dye/TiO2 interface. The findings provide insights into the molecular structure and the charge-transfer characteristics for designing efficient porphyrin sensitizers for DSSC applications.

Influence of Phenylethynylene of Push-Pull Zinc Porphyrins on the Photovoltaic Performance.

A series of zinc porphyrin dyes YD22-YD28 were synthesized and used for dye-sensitized solar cells. Dyes YD26-YD28 consist of zinc porphyrin (ZnP) as core unit, arylamine (Am) as electron-donating group, and p-ethynylbenzoic acid (EBA) as an electron-withdrawing/-anchoring group. The dyes YD22-YD25 contain additional phenylethynylene group (PE) bridged between Am and ZnP units. The influence of the PE unit on molecular properties as well as photovoltaic performances were investigated via photophysical and electrochemical studies and density functional calculations. With the insertion of PE unit, the dyes YD22-YD25 possess better light-harvesting properties in terms of significantly red-shifted Q-band absorption. The conversion efficiencies for dyes YD22-YD25 are better than those of dyes YD26-YD28 owing to larger J(SC) output. Natural transition orbitals and Mulliken charge analysis were used to analyze the electron injection efficiency for porphyrin dyes upon time-dependent DFT calculations. The results indicated that insertion of additional PE unit is beneficial to higher J(SC) by means of improved light-harvesting property due to broadened and red-shifted absorption.

Metal-free organic dyes for TiO2 and ZnO dye-sensitized solar cells.

We report the synthesis and characterization of new metal-free organic dyes (namely B18, BTD-R, and CPTD-R) which designed with D-π-A concept to extending the light absorption region by strong conjugation group of π-linker part and applied as light harvester in dye sensitized solar cells (DSSCs). We compared the photovoltaic performance of these dyes in two different photoanodes: a standard TiO2 mesoporous photoanode and a ZnO photoanode composed of hierarchically assembled nanostructures. The results demonstrated that B18 dye has better photovoltaic properties compared to other two dyes (BTD-R and CPTD-R) and each dye has higher current density (Jsc) when applied to hierarchical ZnO nanocrystallites than the standard TiO2 mesoporous film. Transient photocurrent and photovoltage decay measurements (TCD/TVD) were applied to systematically study the charge transport and recombination kinetics in these devices, showing the electron life time (τR) of B18 dye in ZnO and TiO2 based DSSCs is higher than CPTD-R and BTD-R based DSSCs, which is consistent with the photovoltaic performances. The conversion efficiency in ZnO based DSSCs can be further boosted by 35%, when a compact ZnO blocking layer (BL) is applied to inhibit electron back reaction.

Molecular engineering of organic dyes with a hole-extending donor tail for efficient all-solid-state dye-sensitized solar cells.

We report a new concept for the design of metal-free organic dyes (OD5-OD9) with an extended donor-π-acceptor (D-π-A) molecular framework, in which the donor terminal unit is attached by a hole-extending side chain to retard back electron transfer and charge recombination; the π-bridge component contains varied thiophene-based substituents to enhance the light-harvesting ability of the device. The best dye (OD9) has a D-A-π-A configuration with the hexyloxyphenylthiophene (HPT) side chain as a hole-extension component and a benzothiadiazole (BTD) internal acceptor as a π-extension component. The co-sensitization of OD9 with the new porphyrin dye LW24 enhanced the light-harvesting ability to 800 nm; thus, a power conversion efficiency 5.5 % was achieved. Photoinduced absorption (PIA) and transient absorption spectral (TAS) techniques were applied to account for the observed trend of the open-circuit voltage (VOC ) of the devices. This work provides insights into the molecular design, photovoltaic performance, and kinetics of charge recombination.

High-Performance and Stable Gel-State Dye-Sensitized Solar Cells Using Anodic TiO2 Nanotube Arrays and Polymer-Based Gel Electrolytes.

Highly ordered and vertically oriented TiO2 nanotube (NT) arrays were synthesized with potentiostatic anodization of Ti foil and applied to fabricate gel-state dye-sensitized solar cells (DSSCs). The open structure of the TiO2 NT facilitates the infiltration of the gel-state electrolyte; their one-dimensional structural feature provides effective charge transport. TiO2 NTs of length L=15-35 µm were produced on anodization for periods of t=5-15 h at a constant voltage of 60 V, and sensitized with N719 for photovoltaic characterization. A commercially available copolymer, poly(methyl methacrylate-co-ethyl acrylate) (PMMA-EA), served as a gelling agent to prepare a polymer-gel electrolyte (PGE) for DSSC applications. The PGE as prepared exhibited a maximum conductivity of 4.58 mS cm(-1) with PMMA-EA (7 wt %). The phase transition temperature (Tp) of the PGE containing PMMA-EA at varied concentrations was determined on the basis of the viscosities measured at varied temperatures. Tp increased with increasing concentration of PMMA-EA. An NT-DSSC with L=30 µm assembled using a PGE containing PMMA-EA (7 wt %) exhibited an overall power conversion efficiency (PCE) of 6.9%, which is comparable with that of a corresponding liquid-type device, PCE=7.1%. Moreover, the gel-state NT-DSSC exhibited excellent thermal and light-soaking enduring stability: the best device retained ∼90% of its initial efficiency after 1000 h under 1 sun of illumination at 50 °C, whereas its liquid-state counterpart decayed appreciably after light soaking for 500 h.

[Cervical spondylosis of vertebral artery treated with thermosensitive moxibustion with different dosages: a randomized controlled trial].

OBJECTIVE: To compare the difference in the clinical efficacy on cervical spondylosis of vertebral artery type (CSA) treated with thermosensitive moxibustion at different dosages. METHODS: Sixty cases of CSA were randomized into a saturated moxa dosage group and a regular moxa dosage group, 30 cases in each one. The thermosensitive moxibustion was adopted in the two groups. The mild suspended moxibustion was applied at two acupoints with the strongest thermosensitization. In the saturated moxa dosage group, the moxibustion time was determined by the disappearance of thermosensitization. In the regular moxa dosage group, 15 min was required on each acupoint. The treatment was given twice a day for first 4 days in the two groups. Since the 5th day, the treatment was given once a day, continuously for 10 times, and totally 14 days were required. The score of symptoms and function and clinical efficacy were compared between the two groups before and after treatment as well as 6-month follow-up after treatment. RESULTS: The curative and effective rate was 56.7% (17/30) after treatment and 60.0% (18/30) in 6-month follow-up after treatment in the saturated moxa dosage group, which were superior to 26.7% (8/30) and 30.0% (9/30) in the regular moxa dosage group respectively (P < 0.01, P < 0.05). The scores of clinical symptoms and function after treatment and in follow-up were improved apparently as compared with those before treatment in both groups (all P < 0.01). The scores of clinical symptoms and function after treatment and in follow-up in the saturated moxa dosage group were increased much more apparently than those in the regular moxa dosage group (after treatment: 22.32 +/- 4.64 vs 17.43 +/- 3.21; in follow-up: 23.01 +/- 4.76 vs 18.32 +/- 2.13, both P < 0.01). CONCLUSION: The thermosensitization moxibustion of saturated dosage achieves the superior short-term and long-term efficacies in the treatment of CSA as compared with the regular moxibustion dosage.

Intermedin as a prognostic factor for major adverse cardiovascular events in patients with ST-segment elevation acute myocardial infarction.

Intermedin functions systemically as a potent vasodilator and its plasma levels have been shown to be elevated in patients with acute myocardial infarction. This study aimed to evaluate the prognostic value of plasma intermedin level in the patients with ST-segment elevation acute myocardial infarction. Plasma intermedin concentrations of 128 patients and 128 healthy controls were determined using a radioimmunoassay. Patients were followed up for 6 months for major adverse cardiovascular events (MACE) consisting of cardiovascular mortality, reinfarction, hospitalization for decompensated heart failure, and lift-threatening arrhythmia. The association of plasma intermedin levels with MACE was investigated by univariate and multivariate analyses. Plasma intermedin levels were significantly higher in patients than in healthy subjects. Elevated plasma level of intermedin was identified as an independent predictor of MACE. Receiver operating characteristic curve analysis showed that plasma intermedin levels had high predictive value for MACE. Moreover, its predictive value was similar to Global Registry of Acute Coronary Events scores' based on area under curve. Meantime, it obviously improved Global Registry of Acute Coronary Events scores' predictive value in a combined logistic-regression model. In multivariate Cox's proportional hazard analysis, plasma intermedin level emerged as an independent predictor of MACE-free survival. Thus, our results suggest that high plasma intermedin level is associated with poor outcomes of patients and may be a useful prognostic biomarker in ST-segment elevation acute myocardial infarction.

Application of latent variable model in Rosenberg self-esteem scale.

Latent Variable Models (LVM) are applied to Rosenberg Self-Esteem Scale (RSES). Parameter estimations automatically give negative signs hence no recoding is necessary for negatively scored items. Bad items can be located through parameter estimate, item characteristic curves and other measures. Two factors are extracted with one on self-esteem and the other on the degree to take moderate views, with the later not often being covered in previous studies. A goodness-of-fit measure based on two-way margins is used but more works are needed. Results show that scaling provided by models with more formal statistical ground correlated highly with conventional method, which may provide justification for usual practice.

High-performance large-scale flexible dye-sensitized solar cells based on anodic TiO2 nanotube arrays.

A simple strategy to fabricate flexible dye-sensitized solar cells involves the use of photoanodes based on TiO2 nanotube (TNT) arrays with rear illumination. The TNT films (tube length ∼35 µm) were produced via anodization, and sensitized with N719 dye for photovoltaic characterization. Pt counter electrodes of two types were used: a conventional FTO/glass substrate for a device of rigid type and an ITO/PEN substrate for a device of flexible type. These DSSC devices were fabricated into either a single-cell structure (active area 3.6×0.5 cm2) or a parallel module containing three single cells (total active area 5.4 cm2). The flexible devices exhibit remarkable performance with efficiencies η=5.40% (single cell) and 4.77% (parallel module) of power conversion, which outperformed their rigid counterparts with η=4.87% (single cell) and 4.50% (parallel model) under standard one-sun irradiation. The flexible device had a greater efficiency of conversion of incident photons to current and a broader spectral range than the rigid device; a thinner electrolyte layer for the flexible device than for the rigid device is a key factor to improve the light-harvesting ability for the TNT-DSSC device with rear illumination. Measurements of electrochemical impedance spectra show excellent catalytic activity and superior diffusion characteristics for the flexible device. This technique thus provides a new option to construct flexible photovoltaic devices with large-scale, light-weight, and cost-effective advantages for imminent applications in consumer electronics.

The influence of electron injection and charge recombination kinetics on the performance of porphyrin-sensitized solar cells: effects of the 4-tert-butylpyridine additive.

The effects of the 4-tert-butylpyridine (TBP) additive in the electrolyte on photovoltaic performance of two push-pull porphyrin sensitizers (YD12 and YD12CN) were examined. Addition of TBP significantly increased the open-circuit voltage (VOC) for YD12 (from 550 to 729 mV) but it was to a lesser extent for YD12CN (from 544 to 636 mV); adding TBP also had the effect of reducing the short-circuit current density (JSC) slightly for YD12 (from 17.65 to 17.19 mA cm(-2)) but it led to a significant reduction for YD12CN (from 16.45 to 9.78 mA cm(-2)). The resulting power conversion efficiencies of the YD12 devices increase from 6.2% to 8.5% whereas those of the YD12CN devices decrease from 5.8% to 4.5%. Based on measurements of temporally resolved photoelectric transients of the devices and femtosecond fluorescence decays of thin-film samples, the poor performance of the YD12CN device in the presence of TBP can be understood as being due to the enhanced charge recombination, decreased electron injection, and a lesser extent of inhibition of the intermolecular energy transfer.

Hybrid Titania Photoanodes with a Nanostructured Multi-Layer Configuration for Highly Efficient Dye-Sensitized Solar Cells.

To construct a hybrid titania photoanode containing nanoparticles and nanorods of varied size in a multilayer (ML) configuration for dye-sensitized solar cells, the essence of our ML design is a bilayer system with additional layers of nanorods of well-controlled size inserted between the transparent and the scattering layers to enhance the light-harvesting capability for photosensitizers with small absorptivity, such as Z907. We measured charge-extraction and intensity-modulated photoelectric spectra to show the advantages of one-dimensional nanorods with an improved electron-transport property and an upward shift of the potential band edge; a favorable ML configuration was constructed to have a cascade potential feature for feasible electron transport from long nanorods, to normal nanorods, to small nanoparticles. On the basis of the ML system reported herein, we demonstrate how the performance of a Z907 device is improved to attain η ∼10%, which is a milestone for its future commercialization.

[Expression and role of urotensin II on the lung of patients with pulmonary hypertension with congenital heart disease].

OBJECTIVE: To observe the expression of urotensin II (UII) on the lung of patients with pulmonary hypertension (PH) with congenital heart disease and investigate the meaning of this phenomenon. METHOD: Thirty eight patients with CHD were divided into three groups according to pulmonary arterial systolic pressure (PASP) measured in cardiac catheterization and surgery: normal pulmonary pressure group (N group, PASP < 30 mm Hg, n = 10), mild PH group (M group, PASP ≥ 30 mm Hg, n = 15), severe or moderate PH group (S group, PASP ≥ 50 mm Hg, n = 13). The expression of UII protein and UII mRNA in pulmonary arterioles were measured separately by immunohistochemical (IHC) analysis and in situ hybridization (ISH) analysis. RESULT: (1) The results of UIIIHC staining: The UII protein expression of group M was higher than that of group N (20.22 ± 3.58 vs. 14.34 ± 2.18, P < 0.01), but less than group S (20.22 ± 3.58 vs. 28.92 ± 3.22, P < 0.05). (2) The results of UIIISH mRNA staining were similar to IHC staining, the A value of group M was higher than group N (12.51 ± 2.02 vs. 8.85 ± 1.41, P < 0.05), less than that of group S(12.51 ± 2.02 vs. 25.35 ± 4.33, P < 0.01). (3) Correlation study: there was a positive correlation between the A values of UIIIHC and pulmonary hypertension (r = 0.64, P < 0.01, n = 38), a positive correlation between the A values of UIIISH and pulmonary hypertension (r = 0.58, P < 0.01, n = 38). CONCLUSION: There was the expression of Urotensin II protein and mRNA in the lung of pulmonary hypertension patients with congenital heart disease, and these expression may involve the formation of pulmonary hypertension of congenital heart disease.

Size-controlled anatase titania single crystals with octahedron-like morphology for dye-sensitized solar cells.

A simple hydrothermal method with titanium tetraisopropoxide (TTIP) as a precursor and triethanolamine (TEOA) as a chelating agent enabled growth in the presence of a base (diethylamine, DEA) of anatase titania nanocrystals (HD1-HD5) of controlled size. DEA played a key role to expedite this growth, for which a biphasic crystal growth mechanism is proposed. The produced single crystals of titania show octahedron-like morphology with sizes in a broad range of 30-400 nm; a typical, extra large, octahedral single crystal (HD5) of length 410 nm and width 260 nm was obtained after repeating a sequential hydrothermal treatment using HD3 and then HD4 as a seed crystal. The nanocrystals of size ~30 nm (HD1) and ~300 nm (HD5) served as active layer and scattering layer, respectively, to fabricate N719-sensitized solar cells. These HD devices showed greater V(OC) than devices of conventional nanoparticle (NP) type; the overall device performance of HD attained an efficiency of 10.2% power conversion at a total film thickness of 28 µm, which is superior to that of a NP-based reference device (η = 9.6%) optimized at a total film thickness of 18-20 µm. According to results obtained from transient photoelectric and charge extraction measurements, this superior performance of HD devices relative to their NP counterparts is due to the more rapid electron transport and greater TiO(2) potential.

Design and characterization of alkoxy-wrapped push-pull porphyrins for dye-sensitized solar cells.

Three alkoxy-wrapped push-pull porphyrins were designed and synthesized for dye-sensitized solar cell (DSSC) applications. Spectral, electrochemical, photovoltaic and electrochemical impedance spectroscopy properties of these porphyrin sensitizers were well investigated to provide evidence for the molecular design.