Cell Applications Research Articles

Performance of Isolated Soft Switching Current Fed Lcc-T Resonant Dc-Dc Converter for Pv/Fuel Cell Applications

In this paper, the design and evaluation of isolated soft switching current LCC-T Resonant DC-DC Converter for PV/Fuel cell applications. For the front end inverter switches, zero voltage switching (ZVS) is used for conversion. For voltage double diodes, Zero-Current Switching (ZCS) is used. Earlier, DC-DC converter provides high harmonic currents, so to overcome that, proposed converter is introduced. The proposed converter will improve the content of harmonic current based on the input variations and wide load. To get the required output voltage, transformer ration will be reduced. Because of the, for PV/ Fuel cell applications have better foot Print and high potential. The proposed converter operates in two modes mainly; they are constant frequency mode and constant duty cycle mode. These modes mainly depend on the load demand. At last from results it can observe that gives satisfying proposed theory.

Investigation of singlet oxygen efficiency of di-axially substituted silicon phthalocyanine with sono-photochemical and photochemical studies

Sono-photodynamic therapy (SPDT) is a favorable new modality for the treatment of the tumor cells. Although SPDT improves the therapeutic outcomes in cell applications, unlike PDT, SPDT studies are insufficient. In this study, to contribute to the development of SPDT, a promising sensitizer was synthesized, characterized, and analyzed photophysico-chemical properties. Afterwards, the singlet oxygen quantum yield of the sensitizer was calculated by both photochemical and sono-photochemical studies. When the methods are compared, the sono-photochemical studies (ΦΔ = 0.71 in DMSO, 0.65 in DMF) were found more effective than the photochemical studies (ΦΔ = 0.47 DMSO, 0.41 in DMF) in terms of producing singlet oxygen. This report will pave the way for the synthesis of new sensitizers to be used in SPDT.

Congenital muscular dystrophy-associated inflammatory chemokines provide axes for effective recruitment of therapeutic adult stem cell into muscles

BackgroundCongenital muscular dystrophies (CMD) are a clinically and genetically heterogeneous group of neuromuscular disorders characterized by muscle weakness. The two most prevalent forms of CMD, collagen VI-related myopathies (COL6RM) and laminin α2 deficient CMD type 1A (MDC1A), are both caused by deficiency or dysfunction of extracellular matrix proteins. Previously, we showed that an intramuscular transplantation of human adipose-derived stem cells (ADSC) into the muscle of the Col6a1−/− mice results in efficient stem cell engraftment, migration, long-term survival, and continuous production of the collagen VI protein, suggesting the feasibility of the systemic cellular therapy for COL6RM. In order for this therapeutic approach to work however, stem cells must be efficiently targeted to the entire body musculature. Thus, the main goal of this study is to test whether muscle homing of systemically transplanted ADSC can be enhanced by employing muscle-specific chemotactic signals originating from CMD-affected muscle tissue.MethodsProteomic screens of chemotactic molecules were conducted in the skeletal muscles of COL6RM- and MDC1A-affected patients and CMD mouse models to define the inflammatory and immune activities, thus, providing potential markers of disease activity or treatment effect. Also using a pre-clinical animal model, recapitulating mild Ullrich congenital muscular dystrophy (UCMD), the therapeutic relevance of identified chemotactic pathways was investigated in vivo, providing a basis for future clinical investigations.ResultsComprehensive proteomic screens evaluating relevant human and mouse skeletal muscle biopsies offered chemotactic axes to enhance directional migration of systemically transplanted cells into CMD-affected muscles, including CCL5-CCR1/3/5, CCL2-CCR2, CXCL1/2-CXCR1,2, and CXCL7-CXCR2. Also, the specific populations of ADSC selected with an affinity for the chemokines being released by damaged muscle showed efficient migration to injured site and presented their therapeutic effect.ConclusionsCollectively, identified molecules provided insight into the mechanisms governing directional migration and intramuscular trafficking of systemically infused stem cells, thus, permitting broad and effective application of the therapeutic adult stem cells for CMD treatment.

Crystallization of Optically Thick Amorphous Silicon Films by Near-IR Femtosecond Laser Processing

We demonstrated efficient crystallization of amorphous Si films induced by their direct irradiation with near-IR femtosecond laser pulses coming at sub-MHz repetition rate. Comprehensive analysis of morphology and composition of the laser-annealed film by atomic-force microscopy, Fourier-transform IR, Raman and energy dispersive X-ray spectroscopy as well as numerical modeling of optical spectra confirmed efficient crystallization of amorphous Si and high-quality of the obtained films opening pathway for applications in thin-film solar cells, transistors and displays.

RedquorinXS Mutants with Enhanced Calcium Sensitivity and Bioluminescence Output Efficiently Report Cellular and Neuronal Network Activities.

Considerable efforts have been focused on shifting the wavelength of aequorin Ca2+-dependent blue bioluminescence through fusion with fluorescent proteins. This approach has notably yielded the widely used GFP-aequorin (GA) Ca2+ sensor emitting green light, and tdTomato-aequorin (Redquorin), whose bioluminescence is completely shifted to red, but whose Ca2+ sensitivity is low. In the present study, the screening of aequorin mutants generated at twenty-four amino acid positions in and around EF-hand Ca2+-binding domains resulted in the isolation of six aequorin single or double mutants (AequorinXS) in EF2, EF3, and C-terminal tail, which exhibited markedly higher Ca2+ sensitivity than wild-type aequorin in vitro. The corresponding Redquorin mutants all showed higher Ca2+ sensitivity than wild-type Redquorin, and four of them (RedquorinXS) matched the Ca2+ sensitivity of GA in vitro. RedquorinXS mutants exhibited unaltered thermostability and peak emission wavelengths. Upon stable expression in mammalian cell line, all RedquorinXS mutants reported the activation of the P2Y2 receptor by ATP with higher sensitivity and assay robustness than wt-Redquorin, and one, RedquorinXS-Q159T, outperformed GA. Finally, wide-field bioluminescence imaging in mouse neocortical slices showed that RedquorinXS-Q159T and GA similarly reported neuronal network activities elicited by the removal of extracellular Mg2+. Our results indicate that RedquorinXS-Q159T is a red light-emitting Ca2+ sensor suitable for the monitoring of intracellular signaling in a variety of applications in cells and tissues, and is a promising candidate for the transcranial monitoring of brain activities in living mice.

High colloidal stability ZnO nanoparticles independent on solvent polarity and their application in polymer solar cells

Significant aggregation between ZnO nanoparticles (ZnO NPs) dispersed in polar and nonpolar solvents hinders the formation of high quality thin film for the device application and impedes their excellent electron transporting ability. Herein a bifunctional coordination complex, titanium diisopropoxide bis(acetylacetonate) (Ti(acac)2) is employed as efficient stabilizer to improve colloidal stability of ZnO NPs. Acetylacetonate functionalized ZnO exhibited long-term stability and maintained its superior optical and electrical properties for months aging under ambient atmospheric condition. The functionalized ZnO NPs were then incorporated into polymer solar cells with conventional structure as n-type buffer layer. The devices exhibited nearly identical power conversion efficiency regardless of the use of fresh and old (2 months aged) NPs. Our approach provides a simple and efficient route to boost colloidal stability of ZnO NPs in both polar and nonpolar solvents, which could enable structure-independent intense studies for efficient organic and hybrid optoelectronic devices.

Electronic properties of type-II $$\hbox {GaAs}_{1-x} \hbox {Sb}_{x}$$/GaAs quantum rings for applications in intermediate band solar cells

We present a theoretical analysis of the electronic properties of type-II $$\hbox {GaAs}_{1-x} \hbox {Sb}_{x}$$ /GaAs quantum rings (QRs), from the perspective of applications in intermediate band solar cells (IBSCs). We outline the analytical solution of Schrodinger’s equation for a cylindrical QR of infinite potential depth, and describe the evolution of the QR ground state with QR morphology. Having used this analytical model to elucidate general aspects of the electronic properties of QRs, we undertake multi-band k·p calculations—including strain and piezoelectric effects—for realistic $$\hbox {GaAs}_{1-x} \hbox {Sb}_{x}$$ /GaAs QRs. Our k·p calculations confirm that the large type-II band offsets in $$\hbox {GaAs}_{1-x} \hbox {Sb}_{x}$$ /GaAs QRs provide strong confinement of holes, and further indicate the presence of resonant (quasi-bound) electron states which localise in the centre of the QR. From the perspective of IBSC design the calculated electronic properties demonstrate several benefits, including (i) large hole ionisation energies, mitigating thermionic emission from the intermediate band, and (ii) electron-hole spatial overlaps exceeding those in conventional $$\hbox {GaAs}_{1-x} \hbox {Sb}_{x}$$ /GaAs QDs, with the potential to engineer these overlaps via the QR morphology so as to manage the trade-off between optical absorption and radiative recombination. Overall, our analysis highlights the flexibility offered by the QR geometry from the perspective of band structure engineering, and identifies specific combinations of QR alloy composition and morphology which offer optimised sub-band gap energies for QR-based IBSCs.

Photocaged Nanobodies Delivered into Cells for Light Activation of Biological Processes

AbstractWe have recently reported photocaged nanobodies, termed photobodies, that can be light‐activated in their antigen binding properties due to the removal of the photolabile protection group. We aimed to establish the delivery and activation of photobodies inside mammalian cells, because intracellular protein manipulation and detection by using antibodies and antibody fragments like nanobodies is highly attractive, however, the spatial and temporal control of their application in cells is extremely limited. AntiGFP photobodies with ortho‐nitrobenzyltyrosine in the paratope region were delivered into HeLa cells using the bead‐loading technique. Light‐activation was carried out with spatial control in single cells to trigger binding to a GFP tag fused to endogenously expressed target proteins. By means of its fused nuclear localization sequence, an activated photobody dragged the GFP fusion protein into the nucleus, the kinetics of which could be monitored using live cell microscopy. These results show the potential of photobodies for intracellular applications.

The Effect of Acidity and Rotation Speed in Titanium Dioxide Synthesize Process

The aims of this study are to analyze the effect of acidity and rotational speed in the synthesis of TiO2 using the sol-gel method and to analyze the morphology of synthesized TiO2 nanoparticles and commercial TiO2 using XRD to produce semiconductors for Dye-Sensitized Solar Cell (DSSC) applications. The sol-gel method was used to synthesize TiO2 Nanoparticles. Titanium tetra-isopropoxide (TTIP) was used as a precursor with the variable of the magnetic stirrer rotation speed of 500, 1000 and 1500 rpm. Acidification was achieved by adding acetic acid to Sol-gel solution to produce a pH number of 1, 2, and 3. Nanomaterial was observed with an optical microscope and X-ray Powder Diffraction (X-RD) to determine the morphology and phase of TiO2 crystalline. The results showed that the rotational speed and acidity level of the Sol-gel solution ware played an important role to get the best form of a nanoparticle. At a rotation speed of 1500 rpm with pH 3 and 1000 rpm with pH 2 ware shown characteristics similar to commercial TiO2. In addition to that, the results of XRD characterization of synthesized TiO2 was shown a crystal phase of anatase structure with 18,046 nm crystal size compared to commercial TiO2 with anatase structure and crystal size of 15,554 nm.

Thickness Estimation of TiO<sub>2</sub>-Based Nanotubes Using X-Ray Diffraction Techniques

TiO2-based nanotubes are a very promising material with many applications in solar cells, biomedical devices, gas sensors, hydrogen generation, supercapacitors, and lithium batteries, among others. Nanotube thickness is a very important property since it is related to electronic and surface mechanics. In this sense, transmission electron microscopy (TEM) can be used. However, it can be difficult to acquire a good TEM image because the transversal section of the nanotubes needs to be visible. In this work, TiO2-based nanotubes obtained via hydrothermal synthesis were studied using X-ray line profile analysis. Scherrer and Single-Line methods provided consistent results for the thickness of the nanotubes (≃ 5 nm) when compared with TEM. Additionally, Single-Line method was also applied to estimate the microstrain. The advantage of using XRD is given by the fact that it is a quick and statistically significant analysis when compared with TEM. The results show that XRD can be used as a rapid and reliable alternative for the thickness estimation of nanotubes.

Advancing Stem Cell Technologies and Applications: A Special Collection from the PluriCore Network in the German Stem Cell Network (GSCN).

Current Protocols in Stem Cell Biology is publishing a special collection of eight articles from members of the PluriCore Network in the German Stem Cell Network. © 2020 Wiley Periodicals LLC.

Graphene-Based Near-IR Plasmonic Wide-angle Broadband Perfect Absorber

Nowadays, graphene is one of the most used materials in the manufacturing of optical instruments, such as sensors, photovoltaic cells, and especially absorbers. The unrivaled ability of graphene in the formation of high-quality surface plasmons creates extraordinary features for absorber devices. Here, by exploiting the nanoplasmonic structure consisting of one-dimensional nanophotonic crystal made of graphene-silver half-ellipse grating next to the dielectric layer, the aim of this research is to achieve broadband absorption and perfect absorber in addition to increasing single-layer and multi-layer graphene absorption by creating surface plasmons and study the absorption spectrum in the near-infrared region. For this purpose, the studied nanostructure is optimized under different incident angles, geometric parameters of the structure, and also the dielectric refractive index. The proposed structure increases the absorption of graphene up to 85% along with wondrous absorption bandwidth over the entire near-infrared region from 770 to 3000 nm. In addition to achieving broadband plasmonic perfect absorber, an ultra-broadband, nearly perfect absorber, with the absorption of more than 80% in the whole near-infrared spectral zone has been introduced whose wide range of 1497 nm has an absorption above 90%. This range is far beyond the bandwidth of less than 1200 nm of conventional absorbers. In addition to high strength and low angular sensitivity, this absorber has the wonderful ability to effective absorb the solar radiation and can display abundant applications in solar cells, thermal emitters, and infrared detectors.

Computational Study of Anthracene-Based Organic Dyes for Dye-Sensitized Solar Cells: Effects of Auxiliary Electron Donors

A series of anthracene-based organic dyes with different auxiliary electron donors (diarylamine, carbazole, and indoline) were computationally studied for applications in dye-sensitized solar cells. Density functional theory (DFT) and time-dependent DFT were conducted to reveal electronic and optical properties of 2H-benzophenanthrothienobenzophenanthrothiophene (BPT2) dyes and dye/(TiO2)46 interfaces. Our calculations reveal that all BPT2 dyes show strong light harvesting performance in the red region (620 nm) and a relatively weak optical absorption around 350 nm of the UV–visible spectrum, which is consistent with experimental findings. The intramolecular photoexcitation mainly occurs between the BPT2 unit and the electron acceptor, so the selection of ancillary donors has little influence on the optical properties of the main absorption peak. The introduction of polycyclic aromatic BPT2 moiety to replace the phenyl unit leads to a notably broadened spectrum and a 170-nm redshift in the adsorption peak. Our results are helpful for the molecular design of novel BPT2-based organic dyes for future dye-sensitized solar cells optimizations.

Copy number variant hotspots in Han Taiwanese population induced pluripotent stem cell lines - lessons from establishing the Taiwan human disease iPSC Consortium Bank

BackgroundThe Taiwan Human Disease iPSC Service Consortium was established to accelerate Taiwan’s growing stem cell research initiatives and provide a platform for researchers interested in utilizing induced pluripotent stem cell (iPSC) technology. The consortium has generated and characterized 83 iPSC lines: 11 normal and 72 disease iPSC lines covering 21 different diseases, several of which are of high incidence in Taiwan. Whether there are any reprogramming-induced recurrent copy number variant (CNV) hotspots in iPSCs is still largely unknown.MethodsWe performed genome-wide copy number variant screening of 83 Han Taiwanese iPSC lines and compared them with 1093 control subjects using an Affymetrix genome-wide human SNP array.ResultsIn the iPSCs, we identified ten specific CNV loci and seven “polymorphic” CNV regions that are associated with the reprogramming process. Additionally, we established several differentiation protocols for our iPSC lines. We demonstrated that our iPSC-derived cardiomyocytes respond to pharmacological agents and were successfully engrafted into the mouse myocardium demonstrating their potential application in cell therapy.ConclusionsThe CNV hotspots induced by cell reprogramming have successfully been identified in the current study. This finding may be used as a reference index for evaluating iPSC quality for future clinical applications. Our aim was to establish a national iPSC resource center generating iPSCs, made available to researchers, to benefit the stem cell community in Taiwan and throughout the world.

A non-viral genome editing platform for site-specific insertion of large transgenes

BackgroundThe precise, functional and safe insertion of large DNA payloads into host genomes offers versatility in downstream genetic engineering-associated applications, spanning cell and gene therapies, therapeutic protein production, high-throughput cell-based drug screening and reporter cell lines amongst others. Employing viral- and non-viral-based genome engineering tools to achieve specific insertion of large DNA—despite being successful in E. coli and animal models—still pose challenges in the human system. In this study, we demonstrate the applicability of our lambda integrase-based genome insertion tool for human cell and gene therapy applications that require insertions of large functional genes, as exemplified by the integration of a functional copy of the F8 gene and a Double Homeobox Protein 4 (DUX4)-based reporter cassette for potential hemophilia A gene therapy and facioscapulohumeral muscular dystrophy (FSHD)-based high-throughput drug screening purposes, respectively. Thus, we present a non-viral genome insertion tool for safe and functional delivery of large seamless DNA cargo into the human genome that can enable novel designer cell-based therapies.MethodsPreviously, we have demonstrated the utility of our phage λ-integrase platform to generate seamless vectors and subsequently achieve functional integration of large-sized DNA payloads at defined loci in the human genome. To further explore this tool for therapeutic applications, we used pluripotent human embryonic stem cells (hESCs) to integrate large seamless vectors comprising a ‘gene of interest’. Clonal cell populations were screened for the correct integration events and further characterized by southern blotting, gene expression and protein activity assays. In the case of our hemophilia A-related study, clones were differentiated to confirm that the targeted locus is active after differentiation and actively express and secrete Factor VIII.ResultsThe two independent approaches demonstrated specific and functional insertions of a full-length blood clotting F8 expression cassette of ~ 10 kb and of a DUX4 reporter cassette of ~ 7 kb in hESCs.ConclusionWe present a versatile tool for site-specific human genome engineering with large transgenes for cell/gene therapies and other synthetic biology and biomedical applications.

Regenerative application of stromal vascular fraction cells enhanced fat graft maintenance: clinical assessment in face rejuvenation

ABSTRACT Objectives The aim of this study was to evaluate the safety and efficacy of the use of FG-SVFs in face rejuvenation for esthetic improvement. Methods 33 female patients affected by face’s soft-tissue defects with loss of volume, study group (SG), were treated with FG-SVFs, comparing results with a control group (CG) (n = 30) treated with fat graft not enhanced (FG). Clinical evaluation, a photographic assessment, magnetic resonance imaging (MRI), and ultrasound (US) were performed. Post-operative follow-up was performed at 1, 3, 7, 12, 24, 48, weeks, and then annually. Results SG patients showed 61% maintenance of the contour restoring and of volume after 3 years compared with the CG treated with FG, who showed 31% maintenance. 60.7% (n = 20) of SG patients, presented an increase of 6.6 mm in the soft tissue volume after 36 months, which was reported in only 33,3% (n = 10) of the CG. Volumetric persistence in the SG was higher than that in the CG (p <. 0001 vs. CG). MRI and US moreover confirmed the absence of important side effects, as fat necrosis, and cytosteatonecrotic areas. Conclusions The use of FG-SVFs was safe and effective in this series of a case treated.

Immuno-oncology cell therapy branches out

Optimization of CAR-T cell technology and application of other immune cell types such as NK cells are tackling the efficacy, cost and logistical challenges of cell therapies for cancer. Optimization of CAR-T cell technology and application of other immune cell types such as NK cells are tackling the efficacy, cost and logistical challenges of cell therapies for cancer.

Corrigendum to: "Development and Application of TK6-derived Cells Expressing Human Cytochrome P450s for Genotoxicity Testing".

Corrigendum to: "Development and Application of TK6-derived Cells Expressing Human Cytochrome P450s for Genotoxicity Testing".

Efficient light harvesting using simple porphyrin-oxide perovskite system

Here, we report the systematic studies on photoanodes of phase pure polycrystalline microrods of Barium Stannate (BaSnO3) microrods for application in porphyrin dye-sensitized solar cell (DSSC). We were able to establish the effect of vacuum annealing on BaSnO3 thin films on its electrical, optical and adsorption properties using XPS, UV–Vis, photoluminescence and adsorption isotherm studies. Increase in oxygen vacancy with annealing is found to increase the room temperature (RT) electron mobility from 49.1 to 82.4 cm2/V sec whereas macroporous nature of samples were found suitable for faster dye adsorption (~ 30 min). Post TiCl4 treatment studies, the maximum efficiency (η) of 4.7% is achieved in BSO films with current density Jsc ~ value as 10.4 mA/cm2; whereas DSSC fabricated using annealed BSO films gave maximum efficiency of 6.1% with Jsc value as 12.2 mA/cm2, during which the value of FF increased from 73.4 to 81%. The IPCE and proposed electron transfer mechanism suggested the potential application of macroporous BSO with unconventional dyes such as metallised-porphyrin. Our results strengthen the idea of using phase-pure, visible transparent porous BSO nanostructures with induced oxygen vacancies due to annealing process post-synthesis which eventually increased DSSC performance from by 84%.

Bone Marrow Concentrate in the Treatment of Aneurysmal Bone Cysts: A Case Series Study

Introduction A recent attractive option regarding mesenchymal stem cells (MSC) application is the treatment of bone cystic lesions and in particular aneurysmal bone cysts (ABC), in order to stimulate intrinsic healing. We performed a retrospective evaluation of the results obtained at our institution. Methods The study group consisted of 46 cases with an average follow-up of 33 months. Forty-two patients underwent percutaneous treatment as the first approach; four patients had curettage as first treatment. In all cases, autologous bone marrow concentrate (BMC) was associated too. The healing status was followed up through a plain radiograph 45 days and 2 months after the procedure. Results and Conclusions. At the final follow-up, thirty-six patients healed with a Neer type II aspect, nine healed with a type I aspect, and one patient was not classified having total hip arthroplasty. Bone marrow concentrate is easy to obtain and to manipulate and can be immediately available in a clinical setting. We can assert that the use of BMC must be encouraged being harmless and having an unquestionable high osteogenic and healing potential in bone defects.