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Recently, mixed antisolvents have been widely used to fabricate perovskite solar cells. In this study, we prepared a mixed antisolvent by mixing tetrahydrofuran (THF), which is a Lewis base, and ethyl acetate (EA). We found that the addition of THF to the antisolvent decreased the amount of residual PbI2 and charge traps in the triple-cation perovskite owing to crystallization control and defect passivation through Lewis base–acid interactions. In the proposed process, an improved power conversion efficiency (PCE) was achieved when another Lewis base, dimethyl sulfoxide (DMSO), was not used in the perovskite precursor preparation, although most other recent studies mixed DMSO in the precursor solvent. The PCE of the optimum device in the inverted structure based on the triple-cation perovskite fabricated using the THF–EA mixed antisolvent was 19.26%, and that of the device with pure EA was 16.14%. The THF–EA antisolvent also yielded better environmental stability than that using the pure EA antisolvent. [ABSTRACT FROM AUTHOR]

Lead-based halide perovskite materials are being developed as efficient light-absorbing materials for use in perovskite solar cells (PSCs). PSCs have shown remarkable progress in power conversion efficiency, increasing from 3.80% to more than 25% within a decade, showcasing their potential as a promising renewable energy technology. Although PSCs have many benefits, including a high light absorption coefficient, the ability to tune band gap, and a long charge diffusion length, the poor stability and the toxicity of lead represent a significant disadvantage for commercialization. To address this issue, research has focused on developing stable and nontoxic halide perovskites for use in solar cells. A potential substitute is halide double perovskites (HDPs), particularly vacancy-ordered HDPs, as they offer greater promise because they can be processed using a solution-based method. This review provides a structural analysis of HDPs, the various synthesis methods for vacancy-ordered HDPs, and their impact on material properties. Recent advances in vacancy-ordered HDPs are also discussed, including their role in active and transport layers of solar cells. Furthermore, valuable insights for developing high-performance vacancy-ordered HDP solar cells are reported from the detailed information presented in recent simulation studies. Finally, the potential of vacancy-ordered HDPs as a substitute for lead-based perovskites is outlined. Overall, the ability to tune optical and electronic properties and the high stability and nontoxicity of HDPs have positioned them as a promising candidate for use in photovoltaic applications. [ABSTRACT FROM AUTHOR]

Over the past decade, perovskite technology has been increasingly applied in solar cells, nanocrystals, and light-emitting diodes (LEDs). Perovskite nanocrystals (PNCs) have attracted significant interest in the field of optoelectronics owing to their exceptional optoelectronic properties. Compared with other common nanocrystal materials, perovskite nanomaterials have many advantages, such as high absorption coefficients and tunable bandgaps. Owing to their rapid development in efficiency and huge potential, perovskite materials are considered the future of photovoltaics. Among different types of PNCs, CsPbBr3 perovskites exhibit several advantages. CsPbBr3 nanocrystals offer a combination of enhanced stability, high photoluminescence quantum yield, narrow emission bandwidth, tunable bandgap, and ease of synthesis, which distinguish them from other PNCs, and make them suitable for various applications in optoelectronics and photonics. However, PNCs also have some shortcomings: they are highly susceptible to degradation caused by environmental factors, such as moisture, oxygen, and light, which limits their long-term performance and hinders their practical applications. Recently, researchers have focused on improving the stability of PNCs, starting with the synthesis of nanocrystals and optimizing (i) the external encapsulation of crystals, (ii) ligands used for the separation and purification of nanocrystals, and (iii) initial synthesis methods or material doping. In this review, we discuss in detail the factors leading to instability in PNCs, introduce stability enhancement methods for mainly inorganic PNCs mentioned above, and provide a summary of these approaches. [ABSTRACT FROM AUTHOR]

Researching planar heterojunction perovskite solar cells has become increasingly popular in view of pursuing both a better photovoltaic performance and enhanced environmental stability. Recently, the use of integrated hole transport layers (HTLs) has attracted much attention because of the improvements in power conversion efficiencies (PCEs). However, previous research studies usually focused on the HTLs in regular-type devices, which do not affect the formation of perovskite crystals. Here, we developed the HTL for inverted solar cells, which integrated organic poly[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b]-dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl] (PTB7) with poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS). PTB7 is used to tune the energy alignment and hydrophobicity of PEDOT:PSS to improve the hole transportation and perovskite formation. The integrated HTL (PEDOT:PSS/PTB7) demonstrated an enhanced hole extraction performance in perovskite solar cells due to better matched energy alignment. Furthermore, the hydrophobic nature of PTB7 provides a non-wetting surface that is beneficial to the crystal formation of perovskite, resulting in higher quality perovskite crystals. Using this simple process, the developed group exhibited a PCE of 18.43%, which was 16.5% higher than that of the reference devices (15.82%). In addition, due to the moisture-blocking characteristics of PTB7, the long-term stability of the devices was also obviously enhanced under ambient air conditions (25 °C) without encapsulation. [ABSTRACT FROM AUTHOR]

Scientific techniques on perovskite solar cells have been significantly developed since the emergence of organic–inorganic hybrid perovskite materials. An antisolvent strategy for preparing perovskite films has been widely used, which is important to improve the photovoltaic performance. In this work, an appropriate amount of diethyl ether (DE), which is usually used as an antisolvent, is added into the perovskite precursor to promote the crystallization of perovskite throughout the entire process. Due to the fast evaporation rate and Lewis base nature of DE, a quicker nuclei formation and retarded nuclei growth of the perovskite can be induced. Consequently, the quality of the perovskite film is improved with enlarged grain size and enhanced crystallinity. Based on this technique, the optimized perovskite solar cells exhibit an improved 19.2% power conversion efficiency (PCE), whereas the control devices only have a lower PCE of 16.8%. In addition, the environmental stability of the perovskite solar cells is also enhanced due to the decreased intrinsic defects of the perovskite film. After 500 h storage in ambient air (approximately 25 °C and 30% relative humidity) without encapsulation, the developed group maintains about 84% of their initial PCE, which is higher than that (77%) of the control group. [ABSTRACT FROM AUTHOR]

The two dimensional (2D) to three dimensional (3D) transition for the protonated water cluster has been controversial, in particular, for H+(H2O)7. For H+(H2O)7 the 3D structure is predicted to be lower in energy than the 2D structure at most levels of theory without zero-point energy (ZPE) correction. On the other hand, with ZPE correction it is predicted to be either 2D or 3D depending on the calculational levels. Although the ZPE correction favors the 3D structure at the level of coupled cluster theory with singles, doubles, and perturbative triples excitations [CCSD(T)] using the aug-cc-pVDZ basis set, the result based on the anharmonic zero-point vibrational energy correction favors the 2D structure. Therefore, the authors investigated the energies based on the complete basis set limit scheme (which we devised in an unbiased way) at the resolution of the identity approximation Mo\ller-Plesset second order perturbation theory and CCSD(T) levels, and found that the 2D structure has the lowest energy for H+(H2O)7 [though nearly isoenergetic to the 3D structure for D+(D2O)7]. This structure has the Zundel-type configuration, but it shows the quantum probabilistic distribution including some of the Eigen-type configuration. The vibrational spectra of MP2/aug-cc-pVDZ calculations and Car-Parrinello molecular dynamics simulations, taking into account the thermal and dynamic effects, show that the 2D Zundel-type form is in good agreement with experiments. [ABSTRACT FROM AUTHOR]

To understand the hydration phenomena of noble transition metals, we investigated the structures, hydration energies, electronic properties, and spectra of the Cu+(H3O)1–6 and Au+(H2O)1–6 clusters using ab initio calculations. The coordination numbers of these clusters are found to be only two, which is highly contrasted to those of Ag+(H2O)n (which have the coordination numbers of 3–4) as well as the hydrated alkali metal ions (which have the coordination numbers of ∼6). For the possible identification of their interesting hydration structures, we predict their IR spectra for the OH stretch modes. [ABSTRACT FROM AUTHOR]

Electronic, optoelectronic, and optical devices have become integral to the fabric of the modern life, underpinning critical advancements in information technology, energy utilization, biotechnology, environmental monitoring, and nanotechnology. Perovskite nanocrystals have captivated researchers for their optoelectronic properties, and Liu and Lee provide a comprehensive review of advancements in perovskite nanocrystal stability enhancement [[4]]. [Extracted from the article]

In this study, we fabricated a silk scaffold containing nano-hydroxyapatite (nano-HAp) for bone tissue engineering applications. The sericin-extracted silk scaffolds were coated with 0.30, 0.15, and 0.03 g of nano-HAp. The scaffolds were soaked in a 1% type I atelocollagen solution and lyophilized. Scaffolds were crosslinked with 0.02% carbodiimide and lyophilized for 48 h, followed by sterilization with γ-irradiation at 10 kGy. The scaffold properties were investigated by energy-dispersive X-ray spectroscopy and atomic force microscope. A typical spectrum of the inorganic crust and the electron diffraction patterns revealed peaks for calcium, phosphorus, and oxygen atoms. Root mean square values of the control and experimental group surfaces were 5.60 and 40.32 nm. The width of nano-HAp was in the approximate range 100–150 nm, and the height was approximately 350 nm. Dental pulp cells were seeded at a density of 2.8 × 104 cells/cm2 and cultured for 3 weeks in a growth medium. The cells were then cultured for 4 weeks in differentiation medium and were transplanted into a nude mouse. The biopsy was processed at 8 weeks. The use of 0.15 g of nano-HAp led to the greatest collagen type III, fibronectin, osteocalcin, osteopontin, osteonectin, osteoprotegerin, and BMP-2 mRNA levels in vitro after 4 weeks in differentiation medium. Western blotting analysis to elucidate signaling pathways was performed. β-Catenin, phosphorylated-ERK, p38 phosphorylation most increased when 0.15 g of nano-HAp was used compared with the control group. In the histological comparison, osteocalcin and osteopontin synthesis were higher for the silk scaffold that contained 0.15 g of nano-HAp. Among the scaffolds, samples containing 0.15 g of nano-HAp were the most effective for osteogenesis. Therefore, this will be a suitable substrate as a biomaterial for bone tissue engineering applications. [ABSTRACT FROM AUTHOR]

Fullerene derivatives are widely used as efficient electron-transport materials for inverted perovskite solar cells (PSCs). Among them, phenyl-Cx-butyric acid methyl ester (PCxBM; x = 61 or 71) is the most frequently used because of its high solubility and solution processability. However, chemical modification of the original fullerenes (C60 or C70) will decrease the charge mobility, which is detrimental to the performance of PSCs. Moreover, the high cost of fullerene derivatives (such as PCBMs) is an obstacle hindering the commercialization of PSCs. In this study, we developed a pristine fullerene mixture (FM) composed of C60 and C70 as an electron-transport layer (ETL). Because of the increased configurational entropy, the solubility of the C60 and C70 mixture was significantly improved to 52.9 g L−1 (in dichlorobenzene), which may reduce the speed of crystallization of the FM during the spin-coating process, in which the organic solvent is evaporated. With this FM-based ETL, the PSCs exhibited an average power-conversion efficiency (PCE) of 16.9%, which was higher than that (15.2%) of PC61BM-based ones. Additionally, the FM-based ETL exhibited greater hydrophobicity than PC61BM, which led to better moisture tolerance. As a result, the long-term stability of the FM-based PSCs was improved significantly, with reduced PCE degradation (from 26% to 15%) after 150 h under ambient conditions. [ABSTRACT FROM AUTHOR]

We have improved power conversion efficiencies of organic bulk-heterojunction solar cells with the active layer composed of poly(3-hexylthiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) by inserting a PCBM layer between the active layer and adjacent Al cathode. This improvement is mainly due to the increase in short-circuit current, which prevails over the changes in other parameters. The largest improvement of 11.7% is obtained at the PCBM thickness of 10 nm, while further increasing of the thickness degrades the fill factor and eventually induces S-kinks in the current-voltage characteristics. We discuss possible models explaining the efficiency variations with the PCBM thickness and the occurrence of the S-kinks. [ABSTRACT FROM AUTHOR]

In this work, we used poly(3,4-ethylenedioxylenethiophene):poly(styrene sulfonate) (PEDOT:PSS, PH 1000) and poly(bis(4-phenyl)(2,4,6-trimethylphenyl)amine) (PTAA) as anode and hole transport materials, respectively, for fabricating metal oxide-free inverted perovskite solar cells (PSCs). The sheet resistance of the PEDOT:PSS (PH 1000) anode was reduced to 76 Ω sq−1 after treatment with ethylene glycol and phosphoric acid, a level comparable to that of conventional indium tin oxide. The hydrophobicity of PTAA improved the perovskite crystallization, facilitating performance improvements in the PSCs. A high power conversion efficiency (PCE) of 14.23% was achieved for these structured rigid PSCs on a rigid glass substrate, with the short-circuit current density, open-circuit voltage, and fill factor of 19.88 mA cm−2, 1.02 V, and 70.2%, respectively. Flexible PSCs on a polyethylene terephthalate substrate exhibited a high PCE of 10.51% with excellent bendability. Our results indicate that using anodes of PEDOT:PSS (PH 1000) and hole transport layers of PTAA presents a promising fabrication method for high-performance rigid and flexible metal oxide-free PSCs, which suggests future large-scale and roll-to-roll production. [ABSTRACT FROM AUTHOR]

Organolead trihalide perovskite materials have attracted considerable interest for their successful application as light absorbers in efficient photovoltaic cells. Several lead sources have been used for the preparation of perovskites, among which lead acetate (Pb(Ac)2) is an important candidate. However, simply mixing Pb(Ac)2 and methylamine iodide in N,N-dimethylformamide solvent leads to poor perovskite morphology, which is disadvantageous for the device performance. Herein, we used dimethyl sulfoxide (DMSO) as a solvent additive to improve the quality of Pb(Ac)2-based perovskite films. We observed that using 5.0% DMSO could significantly enhance the crystallinity of the perovskite film with enlarged domain size. Consequently, the power conversion efficiency (PCE) of the relevant perovskite solar cells (PSCs) was drastically enhanced from 12.88 to 16.59% (on average), with simultaneous improvement in the open-circuit voltage, short-circuit current density, and fill factor. A champion PCE of 17.06% with negligible hysteresis was achieved for PSCs prepared using 5.0% DMSO as the solvent additive. Our results indicate that using DMSO for the preparation of a Pb(Ac)2-based perovskite film is an effective way to fabricate high-performance PSCs. [ABSTRACT FROM AUTHOR]

In this study, we improved the performance of poly[4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b′] dithiophene-co-3-fluorothieno[3,4-b]thiophene-2-carboxylate]:[6,6]-phenyl-C70-butyric acid methyl ester (PTB7-Th:PC71BM)-based organic solar cells (OSCs) by thermally evaporating additional acceptors PC71BM or 3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone))-5,5,11,11-tetrakis(4-hexylphenyl)-dithieno[2,3-d:2′,3′-d′]-s-indaceno[1,2-b:5,6-b′]dithiophene (ITIC) on the surface of bulk-heterojunction layers. We found that the surface of the bulk-heterojunction layers showed a shortage of acceptor materials due to vertical phase separation, which was detrimental to the power conversion efficiency (PCE). The acceptor addition (PC71BM or ITIC) was beneficial for charge transport and suppressed charge recombination. Addition of a 9 nm PC71BM layer on the surface of the bulk-heterojunction layers significantly improved the performance of rigid OSCs (on glass substrates), and the maximum PCE increased from 8.99% to 10.25%, which was higher than that (9.78%) of the OSCs using ITIC. In addition, the degradation of the OSCs during long-term stability testing reduced from 21% to 14% Furthermore, the PCE of flexible OSCs (on polyethylene naphthalate substrate) improved from 7.65% to 8.52%. Our results indicated that evaporating PC71BM on the surface of bulk-heterojunction layers is a simple and effective method to fabricate high-performance rigid and flexible OSCs. [ABSTRACT FROM AUTHOR]

ABSTRACT In this work, we fabricated plasmonic organic bulk-heterojunction solar cells by inserting hydrophobic gold nanorods (GNRs) into the active layers. Power conversion efficiency was improved from 7.43% to 8.22% because the plasmonic effect of GNRs improved the light harvesting efficiency. Maximum exciton generation rate was increased from 1.35 × 10−26 to 1.51× 10−26m−3 s−1, and the electron mobility was also increased from 8.6 × 10−5 to 1.5× 10−4cm−2 V−1 s−1. As a result, the short circuit current density was improved from 15.5 to 16.7 mA cm−2-the dominant reason for performance enhancement. The open circuit voltage and fill factor were improved simultaneously. The plasmonic device showed a highest PCE of 8.43%, indicating that doping GNRs into active layers is a simple and effective way to fabricate high-performance organic solar cells. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45920. [ABSTRACT FROM AUTHOR]

A simple but sensitive system for the detection of DNA using molybdenum disulfide ( MoS2) as an additive to the DNA solution is reported. According to the described method, the target DNA can be identified by differential pulse voltammetry ( DPV) because single- and double-stranded DNA molecules have different affinities to both the electrochemical indicator used (methylene blue) and MoS2. The MoS2 additive does not require any functionalization to achieve adequate sinking speed, contrary to graphene- and carbon nanotube-based additives. The easy fabrication of the sensitive DNA sensor developed in this study is achieved by simply adding the MoS2 additive into the DNA sample solutions, and does not require any sophisticated processes, such as probe immobilization and chemical modification. The results described in this study pave the way for utilizing semiconducting or insulating two-dimensional materials as additives for simple electrochemical DNA sensors with a great potential for commercial mass production. [ABSTRACT FROM AUTHOR]

Low temperature processed, metal-oxide free planar perovskite solar cells (PSCs) were fabricated on glass and polyethylene terephthalate (PET) substrates using polyetherimide (PEI) modified poly(3,4-ethylenedioxylenethiophene):poly(styrene sulfonate) (PEDOT:PSS) as the cathode. The modification by PEI significantly changed the work function of PEDOT:PSS from −5.06 to −4.08 eV, yielding better electron transportation. The rigid cell on the glass substrate exhibited a high power conversion efficiency (PCE) of 12.42% without significant hysteresis and comparable to the PCE of PSCs with metal oxide cathodes. Moreover, the stability in air was higher by 32% than that of the devices with metal-oxide cathodes. The flexible device on the PET substrate exhibited a PCE of 9.73% and good bendability. Our results indicate that the flexibility of the PEDOT:PSS/PEI cathode is promising for use in large-scale roll-to-roll production of PSCs. [ABSTRACT FROM AUTHOR]

ABSTRACT Morphology control is an important issue for boosting the performance of organic bulk-heterojunction (BHJ) solar cells. In this study, we investigated the correlation between alcohol solvents and the morphologies of poly({4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b′] dithiophene-2,6-diyl}{3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl}) (PTB7) and [6,6]-phenyl-C70-butyric acid methyl ester (PC70BM)-based organic solar cells by spin-casting the alcohol onto the active layers. We found that the morphologies strongly depended on the structure of the alcohol [alkyl chain length and hydroxyl (OH) group position]. Ethanol or 2-propanol showed the highest performance among the alcohols considered here. Atomic force microscopy images and absorption spectra demonstrated that the alcohols affected the morphologies of PC70BM rather than those of PTB7. The morphologies of PC70BM were dependent on the solubilities of the alcohols to the active layers and the hydrogen-bonding strengths between the PC70BM and alcohol molecules. Our results indicate that the use of alcohols for solvent annealing is a simple and efficient method for developing high-performance organic BHJ solar cells. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44367. [ABSTRACT FROM AUTHOR]

Herein, we introduce the fabrication of polymer micropattern arrays on a chemically inert poly(dimethylsiloxane) (PDMS) surface and employ them for the selective adhesion of cells. To fabricate the micropattern arrays, a mercapto-ester—based photocurable adhesive was coated onto a mercaptosilane—coated PDMS surface and photopolymerized using a photomask to obtain patterned arrays at the microscale level. Robust polymer patterns, 380 µm in diameter, were successfully fabricated onto a PDMS surface, and cells were selectively targeted toward the patterned regions. Next, the performance of the cell adhesion was observed by anchoring cell adhesive linker, an RGD oligopeptide, on the surface of the mercapto-ester—based adhesive-cured layer. The successful anchoring of the RGD linker was confirmed through various surface characterizations such as water contact angle measurement, XPS analysis, FT-IR analysis, and AFM measurement. The micropatterning of a photocurable adhesive onto a PDMS surface can provide high structural rigidity, a highly–adhesive surface, and a physical pathway for selective cell adhesion, while the incorporated polymer micropattern arrays inside a PDMS microfluidic device can serve as a microfluidic platform for disease diagnoses and high-throughput drug screening. [ABSTRACT FROM AUTHOR]

The chemical modification of electrode surfaces has attracted significant attention for lowering the limit of detection or for improving the recognition of biomolecules; however, the chemical processes are complex, dangerous, and difficult to control. Therefore, instead of the chemical process, we physically modified the surface of carbon-nanotube/polydimethylsiloxane composite electrodes by dip coating them with functionalized multi-walled carbon nanotubes (F-MWCNTs). These electrodes are used as working electrodes in electrochemistry, where they act as a recognition layer for sequence-specific DNA sensing through π–π interactions. The F-MWCNT-modified electrodes showed a limit of detection of 19.9 fM, which was 1250 times lower than that of pristine carbon/polydimethylsiloxane electrodes in a previous study, with a broad linear range of 1–1000 pM. The physically modified electrode was very stable during the electrode regeneration process after DNA detection. Our method paves the way for utilizing physical modification to significantly lower the limit of detection of a biosensor system as an alternative to chemical processes. [ABSTRACT FROM AUTHOR]

Lead(II)-acetate (Pb(Ac)2) is a promising lead source for the preparation of organolead trihalide perovskite materials, which avoids the use of inconvenient anti-solvent treatment. In this study, we investigated the effect of cesium doping on the performance of Pb(Ac)2-based perovskite solar cells (PSCs). We demonstrate that the quality of the CH3NH3PbI3 perovskite film was improved with increased crystallinity and reduced pinholes by doping the perovskite with 5 mol% cesium. As a result, the power conversion efficiency (PCE) of the PSCs was improved from 14.1% to 15.57% (on average), which was mainly induced by the significant enhancements in short-circuit current density and fill factor. A PCE of 18.02% was achieved for the champion device of cesium-doped Pb(Ac)2-based PSCs with negligible hysteresis and a stable output. Our results indicate that cesium doping is an effective approach for improving the performance of Pb(Ac)2-based PSCs. [ABSTRACT FROM AUTHOR]

The role of dental pulp stem cells (DPSCs) in dental tissue regeneration is gaining attention because DPSCs can differentiate into odontoblasts and other specialized cell types. Epigenetic modification has been found to play an important role in cell differentiation and regulation, among which histone deacetylase (HDAC) is involved in suppressing genes by removing histone acetyl groups. The use of HDAC inhibitor to control this is increasing and has been widely studied by many researchers. This study aimed to induce differentiation by causing epigenetic changes in odontoblast-related genes and the MAPK signaling pathway in human dental pulp stem cells. Western blot and immunofluorescence staining showed increased expression of DMP-1, ALP, DSPP, and RUNX2 compared to the control. However, activation of the MAPK signaling system was similar to but slightly different from the expression of odontoblast-related proteins. After 3 days, as shown by MTT and LDH assays, proliferation decreased overall, but cytotoxicity decreased at only a specific concentration. We confirmed that there was no change in mRNA expression of caspase 3 or 9 using real-time PCR. In addition, flow cytometry analysis confirmed that differentiation occurred due to the decrease in the expression of the CD73 and CD146. Although overall proliferation was reduced due to the G2/M inhibition of the cell cycle, the expression of BCL-2 protected the cells from cell death. Overall, cell proliferation decreased in response to MS-275, but it did not induce cytotoxicity in 5 nM and 10 nM concentration and induces differentiation into odontoblast-like cells. [ABSTRACT FROM AUTHOR]

Despite advances in medical treatments, the proportion of the population suffering from alopecia is increasing, thereby creating a need for new treatments to control hair loss and prevent balding. Human hair follicle dermal papilla cells (hDPCs), a type of specialized fibroblast in the hair bulb, play an essential role in controlling hair growth and in conditions like androgenic alopecia. This study aimed to evaluate the intensity-dependent effect of extremely low-frequency electromagnetic fields (ELF-EMFs) on the expression of anagen-related molecules in hDPCs in vitro. We examined the effect of ELF-EMF on hDPCs to determine whether activation of the GSK-3β/ERK/Akt signaling pathway improved hDPC activation and proliferation; hDPCs were exposed to ELF-EMFs at a frequency of 70 Hz and at intensities ranging from 5 to 100 G, over four days. Various PEMF intensities significantly increased the expression of anagen-related molecules, including collagen IV, laminin, ALP, and versican. In particular, an intensity of 10 G is most potent for promoting the proliferation of hDPC and expression of anagen-related molecules. Moreover, 10 G ELF-EMF significantly increased β-catenin and Wnt3α expression and GSK-3β/ERK/Akt phosphorylation. Our results confirmed that ELF-EMFs enhance hDPC activation and proliferation via the GSK-3β/ERK/Akt signaling pathway, suggesting a potential treatment strategy for alopecia. [ABSTRACT FROM AUTHOR]

In this study, numerical simulations were conducted to confirm the possibility of improved mixing performance by using a fluidic oscillator as a fuel injector. Three-dimensional URANS non-reacting simulations were conducted to examine air–fuel mixing in a supersonic flow field of Mach 3.38. The numerical methods were validated through simulations of the oscillating flow generated from the fluidic oscillator. The results show that the mass flow rate and momentum are reduced at the outlet because the total pressure loss increases inside the fluidic oscillator, which means that higher pressure needs to be applied to supply the same mass flow rate. The simulation showed that the flow structure varies over time as the injected flow is swept laterally. With lateral injection, the fuel distribution is long and narrow, and asymmetric vortexes are generated. However, with central injection, the fuel distribution is relatively similar to the case of using a simple injector. Compared to the simple injector, the penetration length, flammable area, and mixing efficiency were improved. However, the total pressure loss in the flow field increases as well. The results showed that the supersonic fluidic oscillator could be fully utilized as a means to enhance the mixing effect, however a method to reduce the total pressure loss is necessary for practical application. [ABSTRACT FROM AUTHOR]

The purpose of the present study is to evaluate the effect of rice bran ash mineral extract (RBM) on pigmentation in zebrafish (Danio rerio). Melanin has the ability to block ultraviolet (UV) radiation and scavenge free oxygen radicals, thus protecting the skin from their harmful effects. Agents that increase melanin synthesis in melanocytes may reduce the risk of photodamage and skin cancer. The present study investigates the effect of RBM on pigmentation in zebrafish and the underlying mechanism. RBM was found to significantly increase the expression of microphthalmia-associated transcription factor (MITF), a key transcription factor involved in melanin production. RBM also suppressed the phosphorylation of extracellular signal-regulated kinase (ERK), which negatively regulates zebrafish pigmentation. Together, these results suggest that RBM promotes melanin biosynthesis in zebrafish. [ABSTRACT FROM AUTHOR]

In this work, we used acetic acid as an additive for the preparation of ZnO layers and improved the performance of poly{4,8-bis[(2-ethylhexyl)-oxy]benzo[1,2-b:4,5-b’] dithiophene-2,6-diyl-alt-3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophene- 4,6-diyl} (PTB7)-based inverted organic solar cells. The addition of acetic acid to the ZnO precursor solution improved the transparency and conductivity of the sol-gel-synthesized ZnO film, by increasing the grain size of the film. Accordingly, the power conversion efficiency (PCE) of the organic solar cells was improved from 6.42% to 7.55%, which was mainly caused by the enhanced current density and fill factor. The best sample demonstrated a high PCE of 7.85% with negligible hysteresis and good stability. Our results indicate that using acetic acid as an additive for the preparation of ZnO is a simple and effective way of fabricating high-performance inverted organic solar cells. [ABSTRACT FROM AUTHOR]

We find that the doping of Cr2O3 nanoparticles into organic bulk-heterojunction solar cells leads to the power conversion efficiency improvements of 15.9%-22.8%, which are larger than or comparable to those obtained using other metal oxide nanostructures in previous studies. The light absorptions at long-wavelength regions and the electron mobilities are enhanced; these enhancement increased the short-circuit current and fill factor. The increased shunt resistance suggests that the hole leakage current may be suppressed. This suppression subsequently enhances the fill factor. Thus, the incorporation of Cr2O3 nanoparticles is a simple and efficient technique for improving bulk-heterojunction devices. [ABSTRACT FROM AUTHOR]

The use of 1,8-diiodooctane (DIO) as a solvent additive in poly[N-9′-heptadecanyl-2,7-carbazole-alt-5, 5-(4′,7′-di-2-thienyl-2′,1′,3′-benzothiadiazole)] (PCDTBT)-based bulk-heterojunction solar cells increased the power conversion efficiency (PCE) by 20.9%. This improvement was due to the increase in the fill factor and open-circuit voltage (Voc), which compensated for the decrease in the short-circuit current (Jsc). DIO had the opposite effect, increasing Jsc and decreasing Voc, in the devices using other low-band gap polymers. The best sample in this study showed a PCE of 6.27% and Voc of 939 mV, indicating that the fabricated device is an efficient solar cell with a high Voc close to 1 V. [ABSTRACT FROM AUTHOR]

The effects of DNA nucleotide adsorption on the conductance of graphene nanoribbons are investigated through first-principles calculations. We find that, for the adsorption of a single nucleotide, the negatively charged phosphate produces conductance dips associated with quasibound states, reducing the hole conductance. The conductance of conduction electrons is also reduced by electron scattering at the Coulomb potential barriers produced by the phosphate, with no noticeable conductance dips near the Fermi level. Our results indicate that graphene nanoribbon is promising for the application to DNA sensor utilizing quantum carrier conductance. [ABSTRACT FROM AUTHOR]