Enhanced N-type Semiconducting Performance of Asymmetric Monochlorinated Isoindigo-based Semiregioregular Polymers under Dynamic Forces.

The asymmetric monochlorination strategy not only effectively addresses the steric issues in conventional dichlorination but also enables the development of promising acceptor units and semiregioregular polymers. Herein, monochlorinated isoindigo (1CIID) is successfully designed and synthesized by selectively introducing single chlorine (Cl) atoms. Furthermore, the 1CIID copolymerizes with two donor counterparts, centrosymmetric 2,2'-bithiophene (2T) and axisymmetric 4,7-di(thiophen-2-yl)benzo[1,2,5]thiadiazole (DTBT), forming two polymers, P1CIID-2T and P1CIID-DTBT. These polymers exhibit notable differences in backbone linearity and dipole moments, influenced by the symmetry of their donor counterparts. In particular, P1CIID-2T, which contains a centrosymmetric 2T unit, demonstrates a linear backbone and a significant dipole moment of 10.20 D. These properties contribute to the favorable film morphology of P1CIID-2T, characterized by highly ordered crystallinity in the presence of fifth-order (500) X-ray diffraction peaks. Notably, P1CIID-2T exhibits a significant improvement in molecular alignment under dynamic force, resulting in over 8-fold improvement in the performance of organic field-effect transistor (OFET) devices, with superior electron mobility up to 1.22 cm2 V-1 s-1. This study represents the first synthesis of asymmetric monochlorinated isoindigo-based conjugated polymers, highlighting the potential of asymmetric monochlorination for developing n-type semiconducting polymers. Moreover, our findings provide valuable insights into the relationship between the molecular structure and properties.

Output Performance Enhanced Triboelectric Nanogenerators Induced by Magnetic Ink Trapping Property Act as Wearable Sensors.

The demand for clean-energy collection has gradually increased in recent years, making triboelectric nanogenerators a promising research field, because of their advantages in convenient manufacturing, diversified materials, and diverse synthesis and modification possibilities. However, recent studies indicate that charge decay, a major limiting factor in the triboelectric output, prevents the induced charge from combining with the bottom electrode, leading to charge loss. The use of charge-trapping sites to retain the induced charge generated during the friction process is an important solution in the field of triboelectric nanogenerator research. This study proposes the use of an elastic ink with macroscopic magnetism as trapping sites by coating the ink as dots between the polytetrafluoroethylene (PTFE) dielectric layer and the electrode layer. Nickel particles in the magnetic ink are doped into the system as microcapacitors, which prevent the combination of the friction layer and induced charges on the back electrode. Because the nickel itself can be used as a charge-potential trap to capture the charge introduced by the charge-injection process, the charge can be maintained for a long time and achieve a long-term high-output state. The output voltage was more than 6 times that of the reference group without the magnetic-ink coating after 3 h. The results provide a reference direction for research on preventing charge decay and trapping charges in triboelectric nanogenerators.

TGF-ß and SHH Regulate Pluripotent Stem Cell Differentiation into Brain Microvascular Endothelial Cells in Generating an In Vitro Blood-Brain Barrier Model.

Blood-brain barrier (BBB) models are important tools for studying CNS drug delivery, brain development, and brain disease. In vitro BBB models have been obtained from animals and immortalized cell lines; however, brain microvascular endothelial cells (BMECs) derived from them have several limitations. Furthermore, obtaining mature brain microvascular endothelial-like cells (BME-like cells) from human pluripotent stem cells (hPSCs) with desirable properties for establishing BBB models has been challenging. Here, we developed an efficient method for differentiating hPSCs into BMECs that are amenable to the development and application of human BBB models. The established conditions provided an environment similar to that occurring during BBB differentiation in the presence of the co-differentiating neural cell population by the modulation of TGF-ß and SHH signaling. The developed BME-like cells showed well-organized tight junctions, appropriate expression of nutrient transporters, and polarized efflux transporter activity. In addition, BME-like cells responded to astrocytes, acquiring substantial barrier properties as measured by transendothelial electrical resistance. Moreover, the BME-like cells exhibited an immune quiescent property of BBB endothelial cells by decreasing the expression of adhesion molecules. Therefore, our novel cellular platform could be useful for drug screening and the development of brain-permeable pharmaceuticals.

Detection of Red Pepper Powder Adulteration with Allura Red and Red Pepper Seeds Using Hyperspectral Imaging.

This study used shortwave infrared (SWIR) technology to determine whether red pepper powder was artificially adulterated with Allura Red and red pepper seeds. First, the ratio of red pepper pericarp to seed was adjusted to 100:0 (P100), 75:25 (P75), 50:50 (P50), 25:75 (P25), or 0:100 (P0), and Allura Red was added to the red pepper pericarp/seed mixture at 0.05% (A), 0.1% (B), and 0.15% (C). The results of principal component analysis (PCA) using the L, a, and b values; hue angle; and chroma showed that the pure pericarp powder (P100) was not easily distinguished from some adulterated samples (P50A-C, P75A-C, and P100B,C). Adulterated red pepper powder was detected by applying machine learning techniques, including linear discriminant analysis (LDA), linear support vector machine (LSVM), and k-nearest neighbor (KNN), based on spectra obtained from SWIR (1,000-1,700 nm). Linear discriminant analysis determined adulteration with 100% accuracy when the samples were divided into four categories (acceptable, adulterated by Allura Red, adulterated by seeds, and adulterated by seeds and Allura Red). The application of SWIR technology and machine learning detects adulteration with Allura Red and seeds in red pepper powder.

Off-Label Use of Crisdesalazine (GedaCure) in Meningoencephalitis in Two Dogs.

An 8-year-old, castrated male Shih-tzu dog (Case 1) showing ataxia and gait disorder was referred for neurological examination and magnetic resonance imaging. Through comprehensive examinations, the patient was tentatively diagnosed with meningoencephalitis of unknown origin (MUO) and treatment with prednisolone and cytosine arabinoside was started. The symptoms were improving with immunosuppressive treatment. However, severe bacterial cystitis occurred and we could not avoid tapering off prednisolone. Then, neurological signs recurred. Therefore, we added crisdesalazine, which allowed us to reduce the daily dosage of immunosuppressants easily. In another case, a 4-year-old, spayed female Yorkshire terrier dog (Case 2) was referred to our hospital showing a head tilt, circling, and loss of the menace reflex. The patient was tentatively diagnosed with MUO and treatment with some immunosuppressants was attempted. The clinical symptoms improved, but the alleviation was inadequate. Thus, we added crisdesalazine. The neurological signs then markedly improved. Moreover, the drugs could be tapered off more easily than before. Crisdesalazine is a novel drug that has antioxidant and anti-inflammatory action in brain disease and is used particularly for dementia. In this paper, we tried an off-label use of this drug in canine MUO patients, and found that it had, in these two patients, additional therapeutic effects on the MUO.

Primary pyomyositis and uveitis in a cat.

A 6-year-old neutered male Siamese cat was referred for investigation of hindlimb ataxia and blindness of 2 weeks' duration. A swollen right hind limb, with no history of trauma, and no evidence of an external wound, was observed on physical examination. Ophthalmic examination revealed bilateral absence of the menace response and changes consistent with uveitis. Blood tests identified changes consistent with inflammation including serum amyloid A elevation. Infectious disease testing was negative. Degenerate neutrophils and bacterial cocci were detected on fine needle aspiration cytology of the affected limb. Thoracic radiography and abdominal ultrasonography identified no abnormalities. Primary pyomyositis was suspected and clindamycin was prescribed following Penrose drain tube placement. In addition, eye drops containing tobramycin, atropine, and prednisolone were administered. The clinical signs and serum amyloid A level were markedly improved after 5 days of treatment. Based on the medical history and lack of other findings, the uveitis was suspected to be secondary to the pyomyositis. The clinical signs resolved completely, and no recurrence was reported within a 6-month follow-up period. To the best of our knowledge, primary pyomyositis with uveitis has not been previously reported in cats.

Suspected Cerebral Salt Wasting Syndrome with Cervical Spinal Lesion in a Domestic Shorthair Cat.

A 12-year-old spayed female domestic short cat was presented with tetraplegia. The cat also showed signs of hyponatremia and dehydration, which were rapidly corrected by intravenous fluid infusion. Based on thorough physical and neurological examinations, the patient was suspected of having an intracranial disease. MRI revealed a high-signal T2 image of the bilateral parietal cerebral cortical gray matter junction, which is associated with fast electrolyte calibration, and a high-signal T2 image of the C2 spinal cord ventral area, which is associated with ischemic myelopathy. The cat reappeared three days later due to anorexia. Laboratory examinations revealed that the cat was clinically dehydrated and exhibited hyponatremia. Other causes of hyponatremia were excluded through history-taking, laboratory examination, imaging, and therapeutic response to fluid therapy, except for cerebral salt-wasting syndrome (CSWS). The cat was discharged 3 days after the start of fludrocortisone therapy with electrolytes within the normal range. Magnetic resonance imaging (MRI) was performed again 1 month after hospitalization, and the cerebral lesion disappeared, but the spinal cord lesion worsened compared to the previous image. The patient was euthanized due to the progression of the spinal lesion, with a poor prognosis and poor quality of life. This is the first case of suspected CSWS with a cervical spinal lesion in a cat.

Amplified Performance of Charge Accumulation and Trapping Induced by Enhancing the Dielectric Constant via the Cyano Group of 3D-Structured Textile for a Triboelectric Multi-Modal Sensor.

To further improve the output performance of triboelectric devices, reducing charge attenuation and loss has become a hot research topic. Particularly, textiles have emerged as one of the promising research directions for triboelectric devices owing to their special internal structure and large specific surface area. In the present work, polyacrylonitrile fibers are fabricated with two distinct structures to provide a higher dielectric constant due to the strong polar properties brought about by higher dipole moment of the CN group. In addition, the complex and closely connected structure of the textile increases specific internal surface area. As a friction layer, the output voltage is shown to increase to 625% of the initial value (from 8 to 60 V) after the application of friction for a short time due to accumulation property. When acting as a trapping layer, the charge loss after injection is effectively prevented due to excellent charge trapping effect. After 24 h, the triboelectric output performance remains at ≈70% of the initial value (decreasing from 320 to 220 V), which is more than 20 times that of the polytetrafluoroethylene film, which decreases from 125 to 19 V. The device is realized for the advanced application of multi-modal sensors.

Long-wave infrared transparent sulfur polymers enabled by symmetric thiol cross-linker.

Infrared (IR) transmissive polymeric materials for optical elements require a balance between their optical properties, including refractive index (n) and IR transparency, and thermal properties such as glass transition temperature (Tg). Achieving both a high refractive index (n) and IR transparency in polymer materials is a very difficult challenge. In particular, there are significant complexities and considerations to obtaining organic materials that transmit in the long-wave infrared (LWIR) region, because of high optical losses due to the IR absorption of the organic molecules. Our differentiated strategy to extend the frontiers of LWIR transparency is to reduce the IR absorption of the organic moieties. The proposed approach synthesized a sulfur copolymer via the inverse vulcanization of 1,3,5-benzenetrithiol (BTT), which has a relatively simple IR absorption because of its symmetric structure, and elemental sulfur, which is mostly IR inactive. This strategy resulted in approximately 1 mm thick windows with an ultrahigh refractive index (nav > 1.9) and high mid-wave infrared (MWIR) and LWIR transmission, without any significant decline in thermal properties. Furthermore, we demonstrated that our IR transmissive material was sufficiently competitive with widely used optical inorganic and polymeric materials.

Controllable Physical Synergized Triboelectricity, Shape Memory, Self-Healing, and Optical Sensing with Rollable Form Factor by Zn cluster.

To build devices offering users comfortable experience, it is important to focus on form factor and multifunctionality. In this study, for the first time, multifunctional Zn clusters with shape memory, self-healing, triboelectricity, and optical sensing synergized with rollable form factor are designed and fabricated by coordinating COO- and Zn2+ . As pore forming agent, Zn clusters produce hierarchical porous structure depending on Zn amount. Zn clusters are applied as message transmitters and charge containers in optical sensing and corona charge injection, respectively. Moreover, Zn clusters in PVB-COO-Zn serve as positive tribomaterial due to Zn ion doping effect, increasing the output performance as the Zn amount reaches 20 wt%. In addition, injecting positive charge into PVB-COO-Zn 20 lead to more than 24 times increase in output performance compared to those of non-porous structures. The reversibility of Zn clusters endows shape memory and self-healing, synergized with the rollable form factor. The rollability is implemented using the long alkyl chain and the energy absorption of porous structure, providing damage resistance. The advancements in this work provide opportunities for multifunctional and unique applications (shape memory rotating-triboelectric nanogenerator, rollable self-healing touchpad, hidden tag) synergized with rollability that accomplishes working in broadened condition in near future.

Controllable Triboelectric Series Using Gradient Positive and Negative Charge-Confinement Layer with Different Particle Sizes of Mesoporous Carbon Materials.

As a method to maximize the energy efficiency of triboelectric nanogenerators (TENGs), high-voltage charge injection (HVCI) on the surface is a simple and effective method for increasing surface charge densities. In this study, positive and negative triboelectric series are controlled using a 3-layer gradient charge-confinement wherein the particle sizes of the mesoporous carbon spheres (mCSs) are sequentially arranged depending on the external surface area of the mCSs. In the gradient charge-confinement layers of this study, the mCS with different sizes perform charge transport from the surface to a deep position during HVCI while mitigating the charge loss through charge confinement to induce the high space charge densities. Through this process, the output voltage-which is initially 15.2 V-is measured to be 600 V after HVCI, thus representing an increase of about 40 times. Further, to amplify the low output current, which is a disadvantage of triboelectric energy, two types of electrical energy-triboelectric and electromagnetic energy-are produced in single mechanical motion. As a result, the output current produced by the cylindrical TENG and electromagnetic generator is recorded as being 1300 times higher, increasing from 12.8 µA to 17.5 mA.

Facile Strategy for Modulating the Nanoporous Structure of Ultrathin π-Conjugated Polymer Films for High-Performance Gas Sensors.

Conventional conjugated polymer (CP) films based on organic field-effect transistors (OFETs) tend to limit the performance of gas sensors owing to restricted analyte diffusion and limited interactions with the charge carriers that accumulate in the first few monolayers of the CP film in contact with the dielectric layer. Herein, a facile strategy is presented for modulating the morphology and charge-transport properties of nanoporous CP films using shearing-assisted phase separation of polymer blends for fabricating OFET-based chemical sensors. This approach enables the formation of nanoporous films with pore size and thickness in the ranges of 90-550 and 7-27 nm, respectively, which can be controlled simply by varying the shear rate. The resulting OFET sensors exhibit excellent sensing performance when exposed to NH3 gas, demonstrating a high responsivity (≈70.7%) at 10 ppm and good selectivity toward NH3 over various organic solvent vapors. After a comprehensive analysis of the morphology and electrical properties of the CP films, it is concluded that morphological features, such as film thickness and surface area, affect the sensing performance of nanoporous-film-based OFET sensors more significantly compared to the charge-transport characteristics of the films.

Monoclonal antibody K312-based depletion of pluripotent cells from differentiated stem cell progeny prevents teratoma formation.

Human pluripotent stem cells (PSCs) have been utilized as a promising source in regenerative medicine. However, the risk of teratoma formation that comes with residual undifferentiated PSCs in differentiated cell populations is most concerning in the clinical use of PSC derivatives. Here, we report that a monoclonal antibody (mAb) targeting PSCs could distinguish undifferentiated PSCs, with potential teratoma-forming activity, from differentiated PSC progeny. A panel of hybridomas generated from mouse immunization with H9 human embryonic stem cells (hESCs) was screened for ESC-specific binding using flow cytometry. A novel mAb, K312, was selected considering its high stem cell-binding activity, and this mAb could bind to several human induced pluripotent stem cells and PSC lines. Cell-binding activity of K312 was markedly decreased as hESCs were differentiated into embryoid bodies or by retinoic acid treatment. In addition, a cell population negatively isolated from undifferentiated or differentiated H9 hESCs via K312 targeting showed a significantly reduced expression of pluripotency markers, including Oct4 and Nanog. Furthermore, K312-based depletion of pluripotent cells from differentiated PSC progeny completely prevented teratoma formation. Therefore, our findings suggest that K312 is utilizable in improving stem cell transplantation safety by specifically distinguishing residual undifferentiated PSCs. [BMB Reports 2022; 55(3): 142-147].

Quinoidal Small Molecule Containing Ring-Extended Termini for Organic Field-Effect Transistors.

In this work, we synthesized and characterized two quinoidal small molecules based on benzothiophene modified and original isatin terminal units, benzothiophene quinoidal thiophene (BzTQuT) and quinoidal thiophene (QuT), respectively, to investigate the effect of introducing a fused ring into the termini of quinoidal molecules. Extending the terminal unit of the quinoidal molecule affected the extension of π-electron delocalization and decreased the bond length alternation, which led to the downshifting of the collective Raman band and dramatically lowering the band gap. Organic field-effect transistor (OFET) devices in neat BzTQuT films showed p-type transport behavior with low hole mobility, which was ascribed to the unsuitable film morphology for charge transport. By blending with an amorphous insulating polymer, polystyrene, and poly(2-vinylnaphthalene), an OFET based on a BzTQuT film annealed at 150 °C exhibited improved mobility up to 0.09 cm2 V-1 s-1. This work successfully demonstrated that the extension of terminal groups into the quinoidal structure should be an effective strategy for constructing narrow band gap and high charge transporting organic semiconductors.

Enhanced genome editing efficiency of CRISPR PLUS: Cas9 chimeric fusion proteins.

Efforts to improve CRISPR-Cas9 genome editing systems for lower off-target effects are mostly at the cost of its robust on-target efficiency. To enhance both accuracy and efficiency, we created chimeric SpyCas9 proteins fused with the 5'-to-3' exonuclease Recombination J (RecJ) or with GFP and demonstrated that transfection of the pre-assembled ribonucleoprotein of the two chimeric proteins into human or plant cells resulted in greater targeted mutagenesis efficiency up to 600% without noticeable increase in off-target effects. Improved activity of the two fusion proteins should enable editing of the previously hard-to-edit genes and thus readily obtaining the cells with designer traits.

Immunomagnetic microfluidic integrated system for potency-based multiple separation of heterogeneous stem cells with high throughput capabilities.

Multipotent adult stem cells (MASCs) derived from Pluripotent stem cells (PSCs) have found widespread use in various applications, including regenerative therapy and drug screening. For these applications, highly pluripotent PSCs need to be selectively separated from those that show low pluripotency for reusage of PSCs, and MASCs need to be collected for further application. Herein, we developed immunomagnetic microfluidic integrated system (IM-MIS) for separation of stem cells depending on potency level. In this system, each stem cell was multiple-separated in microfluidics chip by magnetophoretic mobility of magnetic-activated cells based on the combination of two sizes of magnetic nanoparticles and two different antibodies. Magnetic particles had a difference in the degree of magnetization, and antibodies recognized potency-related surface markers. IM-MIS showed superior cell separation performance than FACS with high throughput (49.5%) in a short time (<15 min) isolate 1 × 107 cells, and higher purity (92.1%) than MACS. IM-MIS had a cell viability of 89.1%, suggesting that IM-MIS had no effect on cell viability during isolation. Furthermore, IM-MIS did not affect the key characteristics of stem cells including its differentiation potency, phenotype, genotype, and karyotype. IM-MIS may offer a new platform for the development of multi-separation systems for diverse stem cell applications.

Wearable Strain Sensors with Aligned Macro Carbon Cracks Using a Two-Dimensional Triaxial-Braided Fabric Structure for Monitoring Human Health.

Recently, wearable sensors, due to their ability to exhibit characteristics, have been appealing for health monitoring through detection of human motions and vital signals. The development of strain sensors with high sensing performance and wearability has been a great challenge to date. In this study, a textile-based strain sensor with good skin affinity was fabricated through a simple fabrication process of dip-coating 2D triaxial-braided fabrics using carbon ink and then drying. The macro crack aligned on the 2D triaxial-braided fabric with a high-density structure and good recovery force. The sensitivity of textile-based strain sensor can be enhanced due to aligned macro crack formed by prestrained fabricating process and characteristic of the 2D triaxial braided fabric with high dense structure. The optimized sensor exhibits high sensitivity (gauge factor: 128) in a strain range of 0-30%, durability (5000 cycles), washability, low hysteresis, and fast response time (90 ms). Therefore, it can be applied as a wearable sensor that can monitor human motions (large strain) and biosignals (subtle strain).

Vertically and Horizontally Drawing Formation of Graphite Pencil Electrodes on Paper by Frictional Sliding for a Disposable and Foldable Electronic Device.

The objective of this study is to fabricate an electrode by frictional sliding caused by a rough paper surface. The pressure exerted during drawing induces adsorption of the graphite particles by the rough paper and simultaneously reduces the surface roughness of the paper electrode. Repetitive drawing in one-way direction reduced the roughness of the paper surface, decreasing the grain boundaries of graphite. This increases the electron pathway at the electrode, thus reducing the resistance to less than 50 Ω. At the same time, repetitive drawing could confirm that unstable errors caused by the hand could help converge within a certain margin of error. We quantified the relationship between pressure and resistance when drawing on the electrode using a pencil hardness tester. In addition, the electrodes formed by repeated drawing generated a new surface grain and boundary, parallel to the drawing direction, and changed the electrode characteristics with respect to the drawing direction. The grain boundary difference based on the drawing direction was measured via a heating test of the foldable device, a sound pressure level, and laser scattering vibrometer measurements of a linear speaker. The fabricated graphite electrodes can be used in disposable foldable paper electronics because they are prepared using inexpensive materials.

In vivo monitoring platform of transplanted human stem cells using magnetic resonance imaging.

As stem cells show great promise in regenerative therapy, stem cell-mediated therapeutic efficacy must be demonstrated through the migration and transplantation of stem cells into target disease areas at the pre-clinical level. In this study, we developed manganese-based magnetic nanoparticles with hollow structures (MnOHo) and modified them with the anti-human integrin ß1 antibody (MnOHo-Ab) to enable the minimal-invasive monitoring of transplanted human stem cells at the pre-clinical level. Compared to common magnetic resonance imaging (MRI)-based stem cell monitoring systems that use pre-labeled stem cells with magnetic particles before stem cell injection, the MnOHo-Ab is a new technology that does not require stem cell modification to monitor the therapeutic capability of stem cells. Additionally, MnOHo-Ab provides improved T1 MRI owing to the hollow structure of the MnOHo. Particularly, the anti-integrin ß1 antibody (Ab) introduced in the MnOHo targets integrin ß1 expressed in the entire stem cell lineage, enabling targeted monitoring regardless of the differentiation stage of the stem cells. Furthermore, we verified that intravenously injected MnOHo-Ab specifically targeted human induced pluripotent stem cells (hiPSCs) that were transferred to mice testes and differentiated into various lineages. The new stem cell monitoring method using MnOHo-Ab demonstrates whether the injected human stem cells have migrated and transplanted themselves in the target area during long-term stem cell regenerative therapy.