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Abstract In this study, we employ a combination of various in-situ surface analysis techniques to investigate the thermally induced degradation processes in MAPbI3 perovskite solar cells (PeSCs) as a function of temperature under air-free conditions (no moisture and oxygen). Through a comprehensive approach that combines in-situ grazing-incidence wide-angle X-ray diffraction (GIWAXD) and high-resolution X-ray photoelectron spectroscopy (HR-XPS) measurements, we confirm that the surface structure of MAPbI3 perovskite film changes to an intermediate phase and decomposes to CH3I, NH3, and PbI2 after both a short (20 min) exposure to heat stress at 100 °C and a long exposure (>1 hour) at 80 °C. Moreover, we observe clearly the changes in the orientation of CH3NH3 + organic cations with respect to the substrate in the intermediate phase, which might be linked directly to the thermal degradation processes in MAPbI3 perovskites. These results provide important progress towards improved understanding of the thermal degradation mechanisms in perovskite materials and will facilitate improvements in the design and fabrication of perovskite solar cells with better thermal stability.

BackgroundAging causes profound changes of stiffness and compliance in the cardiovascular system, which contributes to decreased cardiovascular reserve. Mechanisms of the underlying endothelial vasodilator dysfunction in vasodilator signaling pathways may occur at multiple sites within any of these pathways.MethodsAge-related changes in the vasculature were investigated in adult young (3-6 months, Y) and old (26-29 month, O) Wistar rats (n = 6). The aortas were carefully dissected from the rat and cut into rings 1.5-2.0 mm in length to measure in vitro isometric tension. Vasorelaxant responses of aortic rings to acetylcholine (ACh), sodium nitroprusside (SNP) and P1075 were examined using Dose Response software (AD Instruments, Mountain View, CA).ResultsEndothelium-dependent vasodilator function was impaired. The endothelium of aging rats impaired endothelial NO dependent vasodilation, but the machinery for vasodilation was not impaired.ConclusionsAge-related NO-mediated vasorelaxation in the aging endothelium was inhibited and appears to be major mechanism of vascular change and impaired vascular regulation.

The transgene toggling device is recognized as a powerful tool for gene- and cell-based biological research and precision medicine. However, many of these devices often operate in binary mode, exhibit unacceptable leakiness, suffer from transgene silencing, show cytotoxicity, and have low potency. Here, we present a novel transgene switch, SIQ, wherein all the elements for gene toggling are packed into a single vector. SIQ has superior potency in inducing transgene expression in response to tebufenozide compared with the Gal4/UAS system, while completely avoiding transgene leakiness. Additionally, the ease and versatility of SIQ make it possible with a single construct to perform transient transfection, establish stable cell lines by targeting a predetermined genomic locus, and simultaneously produce adenovirus for transduction into cells and mammalian tissues. Furthermore, we integrated a cumate switch into SIQ, called SIQmate, to operate a Boolean AND logic gate, enabling swift toggling-off of the transgene after the removal of chemical inducers, tebufenozide and cumate. Both SIQ and SIQmate offer precise transgene toggling, making them adjustable for various researches, including synthetic biology, genome engineering, and therapeutics.

Abstract Osteoporosis is a condition characterized by decreased bone mineral density (BMD) and reduced bone strength, leading to an increased risk of fractures. Here, to identify novel risk variants for susceptibility to osteoporosis-related traits, an exome-wide association study is performed with 6,485 exonic single nucleotide polymorphisms (SNPs) in 2,666 women of two Korean study cohorts. The rs2781 SNP in UBAP2 gene is suggestively associated with osteoporosis and BMD with p-values of 6.1 × 10−7 (odds ratio = 1.72) and 1.1 × 10−7 in the case-control and quantitative analyzes, respectively. Knockdown of Ubap2 in mouse cells decreases osteoblastogenesis and increases osteoclastogenesis, and knockdown of ubap2 in zebrafish reveals abnormal bone formation. Ubap2 expression is associated with E-cadherin (Cdh1) and Fra1 (Fosl1) expression in the osteclastogenesis-induced monocytes. UBAP2 mRNA levels are significantly reduced in bone marrow, but increased in peripheral blood, from women with osteoporosis compared to controls. UBAP2 protein level is correlated with the blood plasma level of the representative osteoporosis biomarker osteocalcin. These results suggest that UBAP2 has a critical role in bone homeostasis through the regulation of bone remodeling.

We investigated the impact of surface treatments on Si-based electrolyte-gated transistors (EGTs) for detecting urea. Three types of EGTs were fabricated with distinct gate electrodes (Ag, Au, Pt) using a top-down method. These EGTs exhibited exceptional intrinsic electrical properties, including a low subthreshold swing of 80 mV/dec, a high on/off current ratio of 106, and negligible hysteresis. Three surface treatment methods ((3-amino-propyl) triethoxysilane (APTES) and glutaraldehyde (GA), 11-mercaptoundecanoic acid (11-MUA), 3-mercaptopropionic acid (3-MPA)) were individually applied to the EGTs with different gate electrodes (Ag, Au, Pt). Gold nanoparticle binding tests were performed to validate the surface functionalization. We compared their detection performance of urea and found that APTES and GA exhibited the most superior detection characteristics, followed by 11-MUA and 3-MPA, regardless of the gate metal. APTES and GA, with the highest pKa among the three surface treatment methods, did not compromise the activity of urease, making it the most suitable surface treatment method for urea sensing.

In this study, we investigated the influence of quasi-one-dimensional (Quasi-1D) characteristics on the source and drain contact resistances within vertical nanowire (NW) field-effect transistors (FETs) of diminutive diameter. The top contact of the NW is segregated into two distinct regions: the first encompassing the upper surface, designated as the axial contact, and the second encircling the side surface, known as the radial contact, which is formed during the top-contact metal deposition process. Quantum confinement effects, prominent within Quasi-1D NWs, exert significant constraints on radial transport, consequently inducing a noticeable impact on contact resistance. Notably, in the radial direction, electron tunneling occurs only through quantized, discrete energy levels. Conversely, along the axial direction, electron tunneling freely traverses continuous energy levels. In a meticulous numerical analysis, these disparities in transport mechanisms unveiled that NWs with diameters below 30 nm exhibit a markedly higher radial contact resistance compared to their axial counterparts. Furthermore, an increase in the overlap length (less than 5 nm) contributes to a modest reduction in radial resistance; however, it remains consistently higher than the axial contact resistance.

Abstract The recent Coronavirus Disease 2019 (COVID‐19) outbreak strongly propels advancements in biosensor technology, leading to the emergence of novel methods for virus detection. Among them, those using nanostructured field‐effect transistors (FETs) provide an ultrasensitive approach toward point‐of‐care diagnostics. However, the application of these biosensors in analyzing biofluids has been limited by their reduced screening length in high ionic strength liquids. To address this challenge, a solution is presented involving the surface modification of FETs with a hydrogel based on star‐shaped polyethylene glycol. This hydrogel is loaded with specific antibodies against the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) spike protein. By incorporating the hydrogel, the effective Debye length is effectively increased, thereby preserving the sensitivity in biofluids. The efficacy of this approach is demonstrated by employing silicon nanonet‐based FETs for the detection of viral antigens in both buffer and saliva, as well as cultured viral particle dispersions. Moreover, positive and negative patient samples are successfully differentiated, showcasing the practical application of this method. Finally, a theoretical frame is proposed to elucidate the underlying mechanism behind the preservation of sensitivity.

The sensing responses of SARS-CoV-2 spike protein using top-down-fabricated Si-based electrolyte-gated transistors (EGTs) have been investigated. An aptamer was employed as a receptor for the SARS-CoV-2 spike protein. The EGT demonstrated excellent intrinsic characteristics and higher sensitivity in the subthreshold regime compared to the linear regime. The limit of detection (LOD) was achieved as low as 0.94 pg/mL and 20 pg/mL for the current and voltage sensitivity, respectively. To analyze the sensing responses of EGT in detecting the aptamer–SARS-CoV-2 spike protein conjugate, a lumped-capacitive model with the presence of an effective dipole potential and an effective capacitance of the functionalized layer component was employed. The aptamer-functionalized EGT showed high sensitivity even in 10 mM phosphate-buffered saline (PBS) solution. These results suggest that Si-based EGTs are a highly promising method for detecting SARS-CoV-2 spike proteins.

Electrical characteristics with various program temperatures (TPGM) in three-dimensional (3-D) NAND flash memory are investigated. The cross-temperature conditions of the TPGM up to 120 °C and the read temperature (TREAD) at 30 °C are used to analyze the influence of grain boundaries (GB) on the bit line current (IBL) and threshold voltage (VT). The VT shift in the E-P-E pattern is successfully decomposed into the charge loss (ΔVT,CL) component and the poly-Si GB (ΔVT,GB) component. The extracted ΔVT,GB increases at higher TPGM due to the reduced GB potential barrier. Additionally, the ΔVT,GB is evaluated using the Technology Computer Aided Design (TCAD) simulation, depending on the GB position (XGB) and the bit line voltage (VBL).

The instability in threshold voltage (VTH) and charge distributions in noncircular cells of three-dimensional (3D) NAND flash memory are investigated. Using TCAD simulation, we aim to identify the main factors influencing the VTH of noncircular cells. The key focus is on the nonuniform trapped electron density in the charge trapping layer (CTL) caused by the change in electric field between the circular region and the spike region. There are less-trapped electron (LT) regions within the CTL of programmed noncircular cells, which significantly enhances current flow. Remarkably, more than 50% of the total current flows through these LT regions when the spike size reaches 15 nm. We also performed a comprehensive analysis of the relationship between charge distribution and VTH in two-spike cells with different heights (HSpike) and angles between spikes (θ). The results of this study demonstrate the potential to improve the reliability of next-generation 3D NAND flash memory.

The SARS-CoV-2 pandemic has triggered many studies worldwide in the area of biosensors, leading to innovative approaches for the quantitative assessment of COVID-19. A nanostructured field-effect transistor (FET) is one type of device shown to be ultrasensitive for virus determination. FETs can be used as transducers to analyze changes in electrical current caused by the bonding of viral molecules to the surface of the semiconducting nanomaterial layer of the FETs. Although nano-transistors require simple setups amenable to be miniaturized for point-of-care diagnostic of COVID-19, this type of sensor usually has limited sensitivity in biological fluids. The reason behind this is the shortened screening length in the presence of high ionic strength solutions. In the frame of this study, we propose a methodology consisting of the FET surface modification with a hydrogel based on the star-shaped polyethylene glycol (starPEG), which hosts specific antibodies against SARS-CoV-2 spike protein in its porous structure. The deposition of the hydrogel increases the effective Debye length, preserving the biosensor’s sensitivity. We demonstrate the capability of silicon nanonet-based FETs to detect viral antigens and cultured viral particles in phosphate-buffered saline (PBS) as well as in human-purified saliva. Finally, we discriminated between positive and negative patients’ nasopharyngeal swab samples.

We experimentally demonstrate Si-based electrolyte-gated transistors (EGTs) for detecting urea. The top-down-fabricated device exhibited excellent intrinsic characteristics, including a low subthreshold swing (SS) (~80 mV/dec) and a high on/off current ratio (~107). The sensitivity, which varied depending on the operation regime, was analyzed with the urea concentrations ranging from 0.1 to 316 mM. The current-related response could be enhanced by reducing the SS of the devices, whereas the voltage-related response remained relatively constant. The urea sensitivity in the subthreshold regime was as high as 1.9 dec/pUrea, four times higher than the reported value. The extracted power consumption of 0.3 nW was extremely low compared to other FET-type sensors.

The extraction of nitride trap density ( $N_{t}$ ) filled with electrons emitted by thermal emission (TE) in the charge-trapping layer of 3-D NAND flash memory is demonstrated. The intercell program (IP) pattern was adopted to intentionally inject electrons into the intercell region to minimize the influence of lateral migration (LM) on the trap profiles. This was confirmed by the retention characteristics observed at 120 °C, where the charge loss is mainly caused by the TE of the trapped electrons in the nitride layer. The extracted peak value of $N_{t}$ at $E_{C}$ - $E_{T}$ value of 1.20 eV using the IP pattern was as low as $1.01\times 10^{19}$ cm−3eV−1, in the scan range of 0.96 eV to 1.27 eV. This value was 17% lower than that from the conventional adjacent cell program (P-P-P) pattern. Therefore, the IP pattern can be used in extracting trap profiles in the SiN layer in scaled 3-D NAND memories.

A wide variety of mesenchymal lesions, benign and malignant tumors can involve the vulvovaginal region. However, it is not easy to make a list for differential diagnoses by imaging modalities or gross findings. Angiomyofibroblastoma (AMFB) is a rare, benign mesenchymal tumor. Most cases of AMFB occur in the female genital tract. We reported a case of a 20-year-old female patient with AMFB on the anterior vaginal wall. The patient visited emergency clinic because of sudden vaginal bleeding that progressively increased. Ultrasound and magnetic resonance imaging revealed an approximately 7.7×5.0 cm mass between the cervix and vaginal wall. Incision was made at the anterior vaginal wall and local excision was performed under general anesthesia. She was discharged without complications and vaginal structure was well recovered. In addition, we reviewed other mesenchymal tumors of the female genitalia for their differential diagnosis. [ABSTRACT FROM AUTHOR]

DNA damage response (DDR) is an evolutionarily conserved mechanism by which eukaryotic cells sense DNA lesions caused by intrinsic and extrinsic stimuli, including virus infection. Although interactions between DNA viruses and DDR have been extensively studied, how RNA viruses, especially coronaviruses, regulate DDR remains unknown. A previous study showed that the porcine epidemic diarrhea virus (PEDV), a member of the genus Alphacoronavirus in the Coronaviridae family, induces DDR in infected cells. However, the underlying mechanism was unclear. This study showed that PEDV activates the ATM-Chk2 signaling, while inhibition of ATM or Chk2 dampens the early stage of PEDV infection. Additionally, we found that PEDV-activated ATM signaling correlates with intracellular ROS production. Interestingly, we showed that, unlike the typical γH2AX foci, PEDV infection leads to a unique γH2AX staining pattern, including phase I (nuclear ring staining), II (pan-nuclear staining), and III (co-staining with apoptotic bodies), which highly resembles the apoptosis process. Furthermore, we demonstrated that PEDV-induced H2AX phosphorylation depends on the activation of caspase-7 and caspase-activated DNAse (CAD), but not ATM-Chk2. Finally, we showed that the knockdown of H2AX attenuates PEDV replication. Taken together, we conclude that PEDV induces DDR through the ROS-ATM and caspase7-CAD-γH2AX signaling pathways to foster its early replication.

DYRK1A is important in neuronal development and function, and its excessive activity is considered a significant pathogenic factor in Down syndrome and Alzheimer's disease. Thus, inhibition of DYRK1A has been suggested to be a new strategy to modify the disease. Very few compounds, however, have been reported to act as inhibitors, and their potential clinical uses require further evaluation. Here, we newly identify CX-4945, the safety of which has been already proven in the clinical setting, as a potent inhibitor of DYRK1A that acts in an ATP-competitive manner. The inhibitory potency of CX-4945 on DYRK1A (IC50=6.8 nM) in vitro was higher than that of harmine, INDY or proINDY, which are well-known potent inhibitors of DYRK1A. CX-4945 effectively reverses the aberrant phosphorylation of Tau, amyloid precursor protein (APP) and presenilin 1 (PS1) in mammalian cells. To our surprise, feeding with CX-4945 significantly restored the neurological and phenotypic defects induced by the overexpression of minibrain, an ortholog of human DYRK1A, in the Drosophila model. Moreover, oral administration of CX-4945 acutely suppressed Tau hyperphosphorylation in the hippocampus of DYRK1A-overexpressing mice. Our research results demonstrate that CX-4945 is a potent DYRK1A inhibitor and also suggest that it has therapeutic potential for DYRK1A-associated diseases.

We report the electrical characteristics and pH responses of a Si-nanonet ion-sensitive field-effect transistor with ultra-thin parylene-H as a gate sensing membrane. The fabricated device shows excellent DC characteristics: a low subthreshold swing of 85 mV/dec, a high current on/off ratio of ~107 and a low gate leakage current of ~10−10 A. The low interface trap density of 1.04 × 1012 cm−2 and high field-effect mobility of 510 cm2V−1s−1 were obtained. The pH responses of the devices were evaluated in various pH buffer solutions. A high pH sensitivity of 48.1 ± 0.5 mV/pH with a device-to-device variation of ~6.1% was achieved. From the low-frequency noise characterization, the signal-to-noise ratio was extracted as high as ~3400 A/A with the lowest noise equivalent pH value of ~0.002 pH. These excellent intrinsic electrical and pH sensing performances suggest that parylene-H can be promising as a sensing membrane in an ISFET-based biosensor platform.