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Floating-gate transistors provide non-volatile analog storage in standard CMOS processes and are crucial in the development of reconfigurable Systems on Chips (SoCs), programmable analog structures, analog neural networks, and mixed-signal neuromorphic circuits. Designing and fabricating these circuits typically involves extensive SPICE-based simulations, yet integrating and calibrating floating-gate transistors post-fabrication is a common practice. To bridge this gap, we present a Verilog-A model based on empirical measurements for a floating-gate transistor fabricated using a 65 nm CMOS process. This model incorporates mechanisms for hot-electron injection and Fowler-Nordheim tunneling, and accurately predicts retention time, thus facilitating the design of adaptive peripheral circuits. Our findings offer insights into optimizing floating-gate transistors for enhanced programming efficiency and reduced area consumption.

Abstract The floating‐gate transistor is commonly employed as a non‐volatile memory device, leveraging a floating node at its gate to store electrical charge over extended periods. This stored charge effectively alters the threshold voltage of the transistor. Utilizing standard CMOS technologies, floating‐gate transistors can be designed and fabricated using conventional CMOS processes. This study focuses on characterizing the performance of a PMOS‐based floating‐gate transistor, specifically fabricated using the open‐source Skywater 130 nm process. The modulation of charge on the floating node is explored through both hot‐electron injection and Fowler–Nordheim tunnelling, providing insight into the resolution of these programming mechanisms. Additionally, the study includes a preliminary analysis of the retention time of the programmed charge in these devices. This work contributes to the open‐source electronics community by detailing the design and programming techniques of floating‐gate transistors developed with an open‐source process design kit, and makes the corresponding FG cell designs available for public use.

Summary: Retinal ganglion cell (RGC) differentiation is tightly controlled by extrinsic and intrinsic factors. Growth and differentiation factor 15 (GDF-15) promotes RGC differentiation, opposite to GDF-11 which inhibits RGC differentiation, both in the mouse retina and in human stem cells. To deepen our understanding of how these two closely related molecules confer opposing effects on retinal development, here we assess the transcriptional profiles of mouse retinal progenitors exposed to exogenous GDF-11 or -15. We find a dichotomous effect of GDF-15 on RGC differentiation, decreasing RGCs expressing residual pro-proliferative genes and increasing RGCs expressing non-proliferative genes, suggestive of greater RGC maturation. Furthermore, GDF-11 promoted the differentiation of photoreceptors and amacrine cells. These data enhance our understanding of the mechanisms underlying the differentiation of RGCs and photoreceptors from retinal progenitors and suggest new approaches to the optimization of protocols for the differentiation of these cell types.

Effective transport layers are essential to suppress non-radiative recombination losses. Here, the authors introduce phenylamino-functionalized ortho-carborane as an interfacial layer, and realise inverted perovskite solar cells with efficiency of over 23% and operational stability of T97 = 400 h.

Abstract Precise diagnosis and immunity to viruses, such as severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) and Middle East respiratory syndrome coronavirus (MERS‐CoV) is achieved by the detection of the viral antigens and/or corresponding antibodies, respectively. However, a widely used antigen detection methods, such as polymerase chain reaction (PCR), are complex, expensive, and time‐consuming Furthermore, the antibody test that detects an asymptomatic infection and immunity is usually performed separately and exhibits relatively low accuracy. To achieve a simplified, rapid, and accurate diagnosis, we have demonstrated an indium gallium zinc oxide (IGZO)‐based biosensor field‐effect transistor (bio‐FET) that can simultaneously detect spike proteins and antibodies with a limit of detection (LOD) of 1 pg mL–1 and 200 ng mL–1, respectively using a single assay in less than 20 min by integrating microfluidic channels and artificial neural networks (ANNs). The near‐sensor ANN‐aided classification provides high diagnosis accuracy (>93%) with significantly reduced processing time (0.62%) and energy consumption (5.64%) compared to the software‐based ANN. We believe that the development of rapid and accurate diagnosis system for the viral antigens and antibodies detection will play a crucial role in preventing global viral outbreaks.

Wearable sensors with edge computing are desired for human motion monitoring. Here, the authors demonstrate a topographic design for wearable MXene sensor modules with wireless streaming or in-sensor computing models for avatar reconstruction.

Adeno-associated virus (AAV)-mediated genetic targeting of microglia remains a challenge. Overcoming this hurdle is essential for gene editing in the central nervous system (CNS). Here, we characterized the minimal/native promoter of the HEXB gene, which is known to be specifically and stably expressed in the microglia during homeostatic and pathological conditions. Dual reporter and serial deletion assays identified the critical role of the natural 5’ untranslated region (−97 bp related to the first ATG) in driving transcriptional activity of the mouse Hexb gene. The native promoter region of mouse, human, and monkey HEXB are located at −135, −134, and −170 bp to the first ATG, respectively. These promoters were highly active and specific in microglia with strong cross-species transcriptional activities, but did not exhibit activity in primary astrocytes. In addition, we identified a 135 bp promoter of CD68 gene that was highly active in microglia but not in astrocytes. Considering that HEXB is specifically expressed in microglia, these data suggest that the newly characterized microglia-specific HEXB minimal/native promoter can be an ideal candidate for microglia-targeting AAV gene therapy in the CNS.

A 19-year-old girl presented with severe pain and redness in her right eye and also with nasal congestion and epistaxis since the past 5 months. The patient was systemically investigated and tested positive for proteinase 3 anti-neutrophil cytoplasmic antibody (PR-3 ANCA) with raised erythrocyte sedimentation rate (ESR). The provisional diagnosis of granulomatosis with polyangiitis (GPA) was made, and she was started on systemic steroids and azathioprine after consultation with the rheumatologist. However on steroid taper, she developed severe reactivation of the scleritis and the corneal involvement was noted in the form of peripheral ulcerative keratitis. Instead of starting another course of high dose oral cortico-steroids or pulse cyclophosphomide, she was started on rituximab infusion (two doses), and oral methotrexate was added, leading to the successful remission of the disease.

Abstract Circulating tumor cells (CTCs) are a treasure trove of information regarding the location, type and stage of cancer and are being pursued as both a diagnostic target and a means of guiding personalized treatment. Most isolation technologies utilize properties of the CTCs themselves such as surface antigens (e.g., epithelial cell adhesion molecule or EpCAM) or size to separate them from blood cell populations. We present an automated monolithic chip with 128 multiplexed deterministic lateral displacement devices containing ~1.5 million microfabricated features (12 µm–50 µm) used to first deplete red blood cells and platelets. The outputs from these devices are serially integrated with an inertial focusing system to line up all nucleated cells for multi-stage magnetophoresis to remove magnetically-labeled white blood cells. The monolithic CTC-iChip enables debulking of blood samples at 15–20 million cells per second while yielding an output of highly purified CTCs. We quantified the size and EpCAM expression of over 2,500 CTCs from 38 patient samples obtained from breast, prostate, lung cancers, and melanoma. The results show significant heterogeneity between and within single patients. Unbiased, rapid, and automated isolation of CTCs using monolithic CTC-iChip will enable the detailed measurement of their physicochemical and biological properties and their role in metastasis.

Transplantation tolerance is achieved when recipients are unresponsive to donor alloantigen yet mobilize against third-party antigens, including virus. After transplantation, cytomegalovirus (CMV) reactivation in latently-infected transplants reduces allograft viability. To determine if pre-tolerized recipients are resistant to viral dissemination in this setting, we transfused chemically-fixed donor splenocytes (1-ethyl-3- (3′-dimethyl-aminopropyl)-carbo-diimide (ECDI)-treated splenocytes (ECDIsp)) to induce donor antigen tolerance without immunosuppression. In parallel, we implanted donor islet cells to validate operational tolerance. These pre-tolerized recipients were implanted with murine CMV (MCMV) latently-infected donor kidneys (a validated model of CMV latency) to monitor graft inflammation and viral dissemination. Our results indicate that tolerance to donor islets was sustained in recipients after implantation of donor kidneys. In addition, kidney allografts implanted after ECDIsp and islet implantation exhibited low levels of fibrosis and tubulitis. In contrast, kidney cellular and innate immune infiltrates trended higher in the CMV group and exhibited increased markers of CD8+ T cell activation. Tolerance induction was unable to prevent increases in MCMV-specific CD8+ T cells or dissemination of viral IE-1 DNA. Our data suggest that latently-infected allografts are inherently more susceptible to inflammation that is associated with viral dissemination in pre-tolerized recipients. Thus, CMV latently-infected allografts require enhanced strategies to protect allograft integrity and viral spread.

We discuss the impact of physical computing techniques to classifying network security issues for ultra-low power networked IoT devices. Physical computing approaches enable at least a factor of 1000 improvement in computational energy efficiency empowering a new generation of local computational structures for embedded IoT devices. These techniques offer computational capability to address network security concerns. This paper begins the discussion of security opportunities for, and issues using, FPAA devices for small embedded IoT platforms. These FPAAs enable devices often utilized for low-power context aware computation. Embedded FPAA devices have both positive Security attributes, as well as potential vulnerabilities. FPAA devices can be part of the resulting secure computation, such as implementing unique functions. FPAA devices can be used investigate security of analog/mixed signal capabilities. The paper concludes with summarizing key improvements for secure ultra-low power embedded FPAA devices.

This paper investigates the variability of various circuits and systems over temperature and presents several methods to improve their performance over temperature. The work demonstrates use of large scale reconfigurable System-On-Chip (SOC) for reducing the variability of circuits and systems compiled on a Floating Gate (FG) based Field Programmable Analog Array (FPAA). Temperature dependencies of circuits are modeled using an open-source simulator built in the Scilab/XCOS environment and the results are compared with measurement data obtained from the FPAA. This comparison gives further insight into the temperature dependence of various circuits and signal processing systems and allows us to compensate as well as predict their behavior. Also, the work presents several different current and voltage references that could help in reducing the variability caused due to changes in temperature. These references are standard blocks in the Scilab/Xcos environment that could be easily compiled on the FPAA. An FG based current reference is then used for biasing a 12 × 1 Vector Matrix Multiplication (VMM) circuit and a second order G m − C bandpass filter to demonstrate the compilation and usage of these voltage/current reference in a reconfigurable fabric. The large scale FG FPAA presented here is fabricated in a 350 nm CMOS process.