Search Results (47)

Mucolipidosis type II (ML II) is a rare and fatal disease of acid hydrolase trafficking. It is caused by pathogenic variants in the GNPTAB gene, leading to the absence of GlcNAc-1-phosphotransferase activity, an enzyme that catalyzes the first step in the formation of the mannose 6-phosphate (M6P) tag, essential for the trafficking of most lysosomal hydrolases. Without M6P, these do not reach the lysosome, which accumulates undegraded substrates. The lack of samples and adequate disease models limits the investigation into the pathophysiological mechanisms of the disease and potential therapies. Here, we report the generation and characterization of an ML II induced pluripotent stem cell (iPSC) line carrying the most frequent ML II pathogenic variant [NM_024312.5(GNPTAB):c.3503_3504del (p.Leu1168fs)]. Skin fibroblasts were successfully reprogrammed into iPSCs that express pluripotency markers, maintain a normal karyotype, and can differentiate into the three germ layers. Furthermore, ML II iPSCs showed a phenotype comparable to that of the somatic cells that originated them in terms of key ML II hallmarks: lower enzymatic activity of M6P-dependent hydrolases inside the cells but higher in conditioned media, and no differences in an M6P-independent hydrolase and accumulation of free cholesterol. Thus, ML II iPSCs constitute a novel model for ML II disease, with the inherent iPSC potential to become a valuable model for future studies on the pathogenic mechanisms and testing potential therapeutic approaches. Full article

KSnI₃-based perovskite solar cells have attracted a lot of research interest due their unique electronic, optical, and thermal properties. In this study, we optimized the performance of various lead-free perovskite solar cell structures—specifically, FTO/Al–ZnO/KSnI₃/rGO/Se, FTO/LiTiO₂/KSnI₃/rGO/Se, FTO/ZnO/KSnI₃/rGO/Se, and FTO/SnO₂/KSnI₃/rGO/Se, using the SCAPS-1D simulation tool. The optimization focused on the thicknesses and dopant densities of the rGO, KSnI₃, Al–ZnO, LiTiO₂, ZnO, and SnO₂ layers, the thickness of the FTO electrode, as well as the defect density of KSnI₃. This yielded PCE values of 27.60%, 24.94%, 27.62%, and 30.21% for the FTO/Al–ZnO/KSnI₃/rGO/Se, FTO/LiTiO₂/KSnI₃/rGO/Se, FTO/ZnO/KSnI₃/rGO/Se, and FTO/SnO₂/KSnI₃/rGO/Se perovskite solar cell configurations, respectively. The FTO/SnO₂/KSnI₃/rGO/Se device is 7.43% more efficient than the FTO/SnO₂/3C-SiC/KSnI₃/NiO/C device, which is currently the highest performing KSnI₃-based perovskite solar cell in the literature. Thus, our FTO/SnO₂/KSnI₃/rGO/Se perovskite solar cell structure is now, by far, the most efficient PSC design. Its best performance is achieved under ideal conditions of a series resistance of 0.5 Ω cm², a shunt resistance of 10⁷ Ω cm², and a temperature of 371 K. Full article

Perovksite solar cells have emerged as a promising photovoltaic technology due to their high increasing power conversion efficiency (PCE). However, challenges related to thermal instability and material toxicity, especially in lead-based perovskites, bring the need to investigate alternative materials and structural designs. This study investigated the current–voltage and power–voltage characteristics of lead-free PSCs based on tin- and germanium using a two-diode equivalent circuit model. The novelty of this work was based on the intensive evaluation of three different electron transport layers (ETLs)—titanium dioxide (TiO₂), zinc oxide (ZnO), and tungsten trioxide (WO₃)—under different ambient temperature conditions (5 °C, 25 °C, and 55 °C) to study their impacts on device performance and the thermal stability. SCAPS-1D simulations were used to model the electrical and optical behaviors of the proposed perovskite structures, and the results were validated by using the two-diode model. The main performance parameters that were considered were open-circuit voltage, short-circuit current, maximum power point, and fill factor. The results showed that TiO₂ was better than ZnO and WO₃ as an ETL, achieving a PCE of 24.83% for Sn-based perovskites, and ZnO was the better choice for Ge-based perovskites at 25 °C, with an efficiency reaching ~15.39%. The three ETL materials showed high thermal stability when analyzing them at high ambient temperatures reaching 55 °C. Full article

This study focuses on the development of efficient and environmentally friendly Lead-free Perovskite solar cells (PSCs) using Tin and Germanium as absorber materials. The study was performed using SCAPS-1D simulations (version 3.11) to explore the performance of PSCs. The investigation took into consideration optimizing the electron transport layer’s (ETL) material and thickness, and TiO₂, ZnO, and WO₃ were investigated for this purpose. The current results show that Sn-based PSCs achieved a maximum power conversion efficiency of 23.19% with TiO₂ as the ETL, while Ge-based PSCs reached a power conversion efficiency of 14.83%. Additionally, the ETL doping concentration optimization revealed that the doping concentration had little impact on the device performance. These results emphasize the potential of Sn- and Ge-based PSCs as sustainable alternatives to Lead-based technologies, offering a pathway toward safer and more efficient solar energy solutions. Full article

Cancers constitute a leading cause of mortality. Chimeric antigen receptor (CAR) cell therapies provide breakthrough solutions for various cancers while posing considerable risks of immunological side reactions. Of various cytotoxic lymphocyte subsets, natural killer (NK) cells are considered the least immunogenic. Obtaining viable NK cells with stable phenotypes in quantities sufficient for modification is technologically challenging. The candidate sources include primary mononuclear cell cultures and immortalized NK cell lines; alternatively, the clinical-grade NK cells can be differentiated from induced pluripotent stem cells (iPSCs) by a good manufacturing practice (GMP)-compatible xeno-free protocol. In this review, we analyze existing protocols for targeted differentiation of human iPSCs into NK cells with a focus on xeno-free requirements. Full article

This study explores the physical, radiation shielding, optical, and photoluminescent properties of PbO₂-SiO₂-based glass systems. Traditional radiation shielding materials, like lead and concrete, face challenges due to toxicity and weight. Glass materials provide an alternative, offering transparency and efficiency. Four glass systems were analyzed: PbO₂-SiO₂ (PS), PbO₂-SiO₂-CeO₂ (PSC), PbO₂-SiO₂-Eu₂O₃ (PSE), and PbO₂-SiO₂-Yb₂O₃ (PSY). The results show that rare earth elements densify the glass network, thereby enhancing radiation attenuation properties, quantified through parameters like the linear attenuation coefficient (μ), the half-value layer (HVL), and the mean free path (MFP). The PSY system exhibited the best shielding properties, demonstrating its potential for use in gamma ray shielding. Samples PS0–PS3 revealed semiconducting behavior and may be considered a promising host matrix for solar cells and w-LED applications. Full article

As an important by-product of pork, pork skin can be processed into meat-based leisure food products to improve its utilization. In this study, microwave vacuum drying (MVD) technology was used to investigate the effects of microwave powers (600, 700, and 800 W) and processing duration on the drying characteristics and quality attributes of pork skin crisps (PSC). Five classical drying models were used to non-linearly fit the experimental data, and the Midilli et al. model was suitable for characterizing the MVD process of PSC. Before reaching a constant rate of drying, increasing microwave power and time can improve the brittleness and expansion ratio of PSC. In the constant rate drying stage, most of the free water in PSC was removed, showing the best brittleness and a stable expansion ratio. High power and long processing time can lead to serious lipid oxidation and change the flavor of PSC. Overall, the desired quality of PSC is recommended as 700 W for 6 min. This study can provide a reference for MVD application of meat-based by-product leisure foods. Full article

CsGeI₂Br-based perovskites, with their favorable band gap and high absorption coefficient, are promising candidates for the development of efficient lead-free perovskite solar cells (PSCs). However, bulk and interfacial carrier non-radiative recombination losses hinder the further improvement of power conversion efficiency and stability in PSCs. To overcome this challenge, the photovoltaic potential of the device is unlocked by optimizing the optical and electronic parameters through rigorous numerical simulation, which include tuning perovskite thickness, bulk defect density, and series and shunt resistance. Additionally, to make the simulation data as realistic as possible, recombination processes, such as Auger recombination, must be considered. In this simulation, when the Auger capture coefficient is increased to 10⁻²⁹ cm⁶ s⁻¹, the efficiency drops from 31.62% (without taking Auger recombination into account) to 29.10%. Since Auger recombination is unavoidable in experiments, carrier losses due to Auger recombination should be included in the analysis of the efficiency limit to avoid significantly overestimating the simulated device performance. Therefore, this paper provides valuable insights for designing realistic and efficient lead-free PSCs. Full article

In this study, a novel perovskite solar cell (PSC) architecture is presented that utilizes an HTL-free configuration with formamide tin iodide (FASnI₃) as the active layer and fullerene (C60) as the electron transport layer (ETL), which represents a pioneering approach within the field. The elimination of hole transport layers (HTLs) reduces complexity and cost in PSC heterojunction structures, resulting in a simplified and more cost-effective PSC structure. In this context, an HTL-free tin HC(NH₂)₂SnI₃-based PSC was simulated using the solar cell capacitance simulator (SCAPS) within a one-dimensional framework. Through this approach, the device performance of this novel HTL-free FASnI₃-based PSC structure was engineered and evaluated. Key performance parameters, including the open-circuit voltage (V_oc), short-circuit current density (J_sc), fill factor (FF), power conversion efficiency (PCE), I-V characteristics, and quantum efficiency (QE), were systematically assessed through the modulation of physical parameters across various layers of the device. A preliminary analysis indicated that the HTL-free configuration exhibited improved I-V characteristics, with a PCE increase of 1.93% over the HTL configuration due to improved electron and hole extraction characteristics, reduced current leakage at the back contact, and reduced trap-induced interfacial recombination. An additional boost to the device’s key performance parameters has been achieved through the further optimization of several physical parameters, such as active layer thickness, bulk and interface defects, ETL thickness, carrier concentration, and back-contact materials. For instance, increasing the thickness of the active layer PSC up to 1500 nm revealed enhanced PV performance parameters; however, further increases in thickness have resulted in performance saturation due to an increased rate of hole–electron recombination. Moreover, a comprehensive correlation study has been conducted to determine the optimum thickness and donor doping level for the C60-ETL layer in the range of 10–200 nm and 10¹²–10¹⁹ cm⁻³, respectively. Optimum device performance was observed at an ETL-C60 ultra-thin thickness of 10 nm and a carrier concentration of 10¹⁹ cm⁻³. To maintain improved PCEs, bulk and interface defects must be less than 10¹⁶ cm⁻³ and 10¹⁵ cm⁻³, respectively. Additional device performance improvement was achieved with a back-contact work function of 5 eV. The optimized HTL-free FASnI₃ structure demonstrated exceptional photovoltaic performance with a PCE of 19.63%, V_oc of 0.87 V, J_sc of 27.86 mA/cm², and FF of 81%. These findings highlight the potential for highly efficient photovoltaic (PV) technology solutions based on lead-free perovskite solar cell (PSC) structures that contribute to environmental remediation and cost-effectiveness. Full article

Ischemic heart disease, a leading cause of death worldwide, manifests clinically as myocardial infarction. Contemporary therapies using mesenchymal stromal cells (MSCs) and their derivative (exosomes, EXOs) were developed to decrease the progression of cell damage during ischemic injury. Laminin alpha 2 (LAMA2) is an important extracellular matrix protein of the heart. Here, we generated MSC-derived exosomes cultivated under LAMA2 coating to enhance human-induced pluripotent stem cell (hiPSC)-cardiomyocyte recognition of LAMA2-EXOs, thus, increasing cell protection during ischemia reoxygenation. We mapped the mRNA content of LAMA2 and gelatin-EXOs and identified 798 genes that were differentially expressed, including genes associated with cardiac muscle development and extracellular matrix organization. Cells were treated with LAMA2-EXOs 2 h before a 4 h ischemia period (1% O₂, 5% CO₂, glucose-free media). LAMA2-EXOs had a two-fold protective effect compared to non-treatment on plasma membrane integrity and the apoptosis activation pathway; after a 1.5 h recovery period (20% O₂, 5% CO₂, cardiomyocyte-enriched media), cardiomyocytes treated with LAMA2-EXOs showed faster recovery than did the control group. Although EXOs had a protective effect on endothelial cells, there was no LAMA2-enhanced protection on these cells. This is the first report of LAMA2-EXOs used to treat cardiomyocytes that underwent ischemia-reoxygenation injury. Overall, we showed that membrane-specific EXOs may help improve cardiomyocyte survival in treating ischemic cardiovascular disease. Full article

Tin oxide (SnO₂) is a technologically important semiconductor with versatile applications. In particular, attention is being paid to nanostructured SnO₂ materials for use as a part of the constituents in perovskite solar cells (PSCs), an emerging renewable energy technology. This is mainly because SnO₂ has high electron mobility, making it favorable for use in the electron transport layer (ETL) in these devices, in which SnO₂ thin films play a role in extracting electrons from the adjacent light-absorber, i.e., lead halide perovskite compounds. Investigation of SnO₂ solution synthesis under diverse reaction conditions is crucial in order to lay the foundation for the cost-effective production of PSCs. This research focuses on the facile catalyst-free synthesis of single-nanometer-scale SnO₂ nanocrystals employing an aromatic organic ligand (as the structure-directing agent) and Sn(IV) salt in an aqueous solution. Most notably, the use of an aromatic amino acid ester hydrochloride salt—i.e., phenylalanine methyl ester hydrochloride (denoted as L hereafter)—allowed us to obtain an aqueous precursor solution containing a higher concentration of ligand L, in addition to facilitating the growth of SnO₂ nanoparticles as small as 3 nm with a narrow size distribution, which were analyzed by means of high-resolution transmission electron microscopy (HR-TEM). Moreover, the nanoparticles were proved to be crystallized and uniformly dispersed in the reaction mixture. The environmentally benign, ethanol-based SnO₂ nanofluids stabilized with the capping agent L for the Sn(IV) ions were also successfully obtained and spin-coated to produce a SnO₂ nanoparticle film to serve as an ETL for PSCs. Several SnO₂ ETLs that were created by varying the temperature of nanoparticle synthesis were examined to gain insight into the performance of PSCs. It is thought that reaction conditions that utilize high concentrations of ligand L to control the growth and dispersion of SnO₂ nanoparticles could serve as useful criteria for designing SnO₂ ETLs, since hydrochloride salt L can offer significant potential as a functional compound by controlling the microstructures of individual SnO₂ nanoparticles and the self-assembly process to form nanostructured SnO₂ thin films. Full article

Tin-based perovskites are promising for realizing lead-free perovskite solar cells; however, there remains a significant challenge to achieving high-performance tin-based perovskite solar cells. In particular, the device fill factor was much lower than that of other photovoltaic cells. Therefore, understanding how the fill factor was influenced by device physical mechanisms is meaningful. In this study, we reported a method to improve the device fill factor using a thin cesium iodide layer modification in tin-based perovskite cells. With the thin passivation layer, a high-quality perovskite film with larger crystals and lower charge carrier densities was obtained. As a result, the series resistance of devices was decreased; the shunt resistance of devices was increased; and the non-radiative recombination of devices was suppressed. Consequently, the fill factor, and the device efficiency and stability were greatly enhanced. The champion tin-based perovskite cells showed a fill factor of 63%, an efficiency of 6.1% and excellent stability. Our study reveals that, with a moderate thin layer modification strategy, the long-term stability of tin-based PSCs can be developed. Full article

By an abrupt rise in the power conservation efficiency (PCE) of perovskite solar cells (PSCs) within a short span of time, the instability and toxicity of lead were raised as major hurdles in the path toward their commercialization. The usage of an inorganic lead-free CsSnI₃-based halide perovskite offers the advantages of enhancing the stability and degradation resistance of devices, reducing the cost of devices, and minimizing the recombination of generated carriers. The simulated standard device using a 1D simulator like solar cell capacitance simulator (SCAPS) with Spiro-OMeTAD hole transporting layer (HTL) at perovskite thickness of 330 nm is in good agreement with the previous experimental result (12.96%). By changing the perovskite thickness and work operating temperature, the maximum efficiency of 18.15% is calculated for standard devices at a perovskite thickness of 800 nm. Then, the effects of replacement of Spiro-OMeTAD with other HTLs including Cu₂O, CuI, CuSCN, CuSbS₂, Cu₂ZnSnSe₄, CBTS, CuO, MoS₂, MoO_x, MoO₃, PTAA, P₃HT, and PEDOT:PSS on photovoltaic characteristics were calculated. The device with Cu₂ZnSnSe₄ hole transport in the same condition shows the highest efficiency of 21.63%. The back contact also changed by considering different metals such as Ag, Cu, Fe, C, Au, W, Ni, Pd, Pt, and Se. The outcomes provide valuable insights into the efficiency improvement of CsSnI₃-based PSCs by Spiro-OMeTAD substitution with other HTLs, and back-contact modification upon the comprehensive analysis of 120 devices with different configurations. Full article

This study investigates fully printed methylamine vapour-treated methylammonium lead iodide (MAPbI₃) hole transport layer (HTL)-free perovskite solar cells (PSCs) with a carbon electrode. We describe a method that can be used to deposit MAPbI₃ films in an ambient environment with doctor blading that is entirely free of spin coating and has precise morphology control, in which the varying input N₂ pressure affects the film morphology. Consequently, a fully printed perovskite solar cell with an ITO/SnO₂/MAPbI₃/carbon structure was fabricated using a doctor-blading SnO₂ electron transport layer and a screen-printed carbon counter electrode. The low-temperature-derived PSCs exhibited a superior power conversion efficiency (PCE) of 14.17% with an open-circuit voltage (V_oc) of 1.02 V on a small-active-area device and the highest efficiency of >8% for an illumination exposure area of 1.0 cm², with high reproducibility. This work highlights the potential of doctor blading and methylamine vapour treatment as promising methods for fabricating high-performance perovskite solar cells. A doctor-blading approach offers a wide processing window for versatile high-performance perovskite optoelectronics in the context of large-scale production. Full article

Organometallic halide perovskite (PVK)-based solar cells (PSC) have gained significant popularity owing to their efficiency, adaptability, and versatility. However, the presence of lead in conventional PVK poses environmental risks and hinders effective commercialization. Although lead-free PVK solar cells have been developed, their conversion efficiency is limited due to intrinsic losses. To address this challenge, we present a simulation study focusing on methylammonium tin bromide (MASnBr₃) as an alternative material. In our investigation, the MASnBr₃ layers are strategically placed between a copper iodide (CuI)-based hole transporting material (HTM) and a zinc oxide (ZnO)-based electron transporting material (ETM). We optimize the active layer thickness, operating temperature, defect density analysis, and series resistances to assess device performance. Furthermore, we employ contour mapping, considering both thickness and defect density, for a detailed investigation. Our primary objective is to achieve unprecedented efficiency in lead-free MASnBr₃-based PSCs. Remarkably, our study achieves the highest J_SC (short-circuit current density) of 34.09 mA/cm², V_OC (open-circuit voltage) of 1.15 V, FF (fill factor) of 82.06%, and optimized conversion efficiency of 32.19%. These advancements in conversion efficiency pave the way for the development of lead-free PVK solar cells in the desired direction. Full article