集積化AlGaN/GaNイオン感応性電界効果トランジスタに関する研究

AlGaN/GaN heterostructure ion-sensitive field-effect transistors (ISFETs) can provide high sensitivity and fast response due to the high electron mobility and high electron density providing by the two-dimensional electron gas (2DEG) generated at the AlGaN/GaN heterostructure interface. My research mainly focuses on the investigation of the integrated AlGaN/GaN ISFETs for pH sensing. To achieve high performance on AlGaN/GaN ISFET pH sensor, we fabricated sensors with different Al composition (25%, and 35%). We compared the characteristics of the sensors with 25% and 35% Al composition. The pH sensor with Al composition (35%) in the barrier layer with a 16 nm transition layer of 25% Al composition shows better surface sensitivity (SV) of 56.01 mV/pH, which is higher than that of the sensor with 25% Al composition (53.94 mV /pH), but worse current sensitivity SA (-0.095 mA/pH Vs -0.102 mA/pH). In addition, threshold voltage increases from approximately -1.6 V to approximately -0.8 V when measured in alkaline solution for 5 times, along with a decreasing output current. High-resolution SEM photos show that there are high density hexagonal pits with the size of approximately 100 nm on the device surface, presenting the etching effect along the dislocations during alkaline sensing. The X-ray photoelectron spectroscopy (XPS) demonstrates that the intensity of the Ga3d and Al2p spectra decreases after pH sensing measurement, implying the variation of chemical component occurs in the upper AlGaN thin layer. Many voids with a size of approximately 100 nm were observed from the transmission electron microscope (TEM) pictures, which are comparable with that of the scanning electron microscope (SEM). Combining with the energy dispersive X-ray spectroscopy (EDX), the degradation in electrical performance can be attributed to the transformation of AlGaN into oxide as well as the followed alkaline solution dissolve. To avoid the reaction of surface Al with solution, a 3 nm GaN cap layer was added. To reduce the barrier layer thickness, a recessed gate with a length of 2 μm and a depth of about 14 nm was formed. The current sensitivity of the AlGaN/GaN ISFET pH sensors has been improved by 61%, from 52.25 to 84.39 μA/pH, by the recessed-gate structure and ammoniate water treatment. A pH meter system based on the GaN pH sensor was constructed and evaluated. GaN-based ISFET can measure the pH value of the solutions with similar circuit, whether in the linear region or the saturation region. The measurement is stable and repeatable. The small current in the linear region can make the measurement stable and fast, but the resolution is a bit low. High resolution can be obtained in the saturation region, but the measurement is unstable due to excessive current. The Schottky barrier diode (SBD) based on GaN can be used for temperature sensing, and the temperature sensitivity can be improved by different structure design. A recessed anode AlGaN/GaN SBD is suitable to integrate with GaN-based power device for temperature sensor application. The temperature dependent forward voltage at a fixed current shows good linearity, resulting in a sensitivity of approximately 1.0 mV/K. The p-NiO guard ring can suppress the electric field at the anode/GaN interface and field crowding at the anode edge effectively, which enhances the breakdown voltage to approximately -250 V. Using the same material, we can design an integrated device sensor based on GaN to measure temperature and pH simultaneously, which will solve the measurement deviation of pH sensor at different temperatures

Distributed Adaptive Huber Regression

Distributed data naturally arise in scenarios involving multiple sources of observations, each stored at a different location. Directly pooling all the data together is often prohibited due to limited bandwidth and storage, or due to privacy protocols. This paper introduces a new robust distributed algorithm for fitting linear regressions when data are subject to heavy-tailed and/or asymmetric errors with finite second moments. The algorithm only communicates gradient information at each iteration and therefore is communication-efficient. Statistically, the resulting estimator achieves the centralized nonasymptotic error bound as if all the data were pooled together and came from a distribution with sub-Gaussian tails. Under a finite $(2+\delta)$-th moment condition, we derive a Berry-Esseen bound for the distributed estimator, based on which we construct robust confidence intervals. Numerical studies further confirm that compared with extant distributed methods, the proposed methods achieve near-optimal accuracy with low variability and better coverage with tighter confidence width.Comment: 29 page

Understanding the Passivation Mechanisms and Opto-Electronic Spectral Response in Methylammonium Lead Halide Perovskite Single Crystals

Attaining control over the surface traps in halide perovskites is critical for the tunability of ultimate device characteristics. Here, we present a study on the modulation of photophysical properties, surface traps, and recombination in MAPbI(3) single crystals (MSCs) with methylamine (MA) vapor surface treatment. Transient photoluminescence spectroscopy in conjunction with density functional theory calculations reveals that nonradiative recombination related to Pb2+ becomes mitigated after MA vaporing while radiative recombination via bimolecular path tends to increase, which originates from the passivation of Pb ions with the Lewis base nitrogen in MA. In contrast to the broad photoresponse in the pristine MSC photodiodes, application of MA surface treatments leads to a spectral narrowing effect (SNE) in MSCs with the response peak width</p

The effect of multimorbidity patterns on physical and cognitive function in diabetes patients: a longitudinal cohort of middle-aged and older adults in China

BackgroundThe prevalence of diabetes has increased rapidly, and comorbid chronic conditions are common among diabetes patients. However, little is known about the pattern of multimorbidity in diabetes patients and the effect on physical and cognitive function. This study aimed to assess the disease clusters and patterns of multimorbidity in diabetes patients using a novel latent class analysis (LCA) approach in middle-aged and older adults and explore the association between different clusters of multimorbidity in diabetes and the effect on physical and cognitive function.MethodsThis national observational study included 1,985 diabetes patients from the four waves of the China Health and Retirement Longitudinal Study (CHARLS) in 2011 to 2018. Thirteen chronic diseases were used in latent class analysis to identify the patterns of multimorbidity in diabetes, which span the cardiovascular, physical, psychological, and metabolic systems. Cognitive function is assessed via a structured questionnaire in three domains: memory, executive function, and orientation. We combined activities of daily living (ADL) with instrumental activities of daily living (IADL) to measure physical function. Linear mixed models and negative binomial regression models were used to analyze the association between patterns of multimorbidity in diabetes and the effect on cognitive function and disability, respectively.ResultsA sample of 1,985 diabetic patients was identified, of which 1,889 (95.2%) had multimorbidity; their average age was 60.6 years (standard deviation (SD) = 9.5), and 53.1% were women. Three clusters were identified: “cardio-metabolic” (n = 972, 51.5%), “mental-dyslipidemia-arthritis” (n = 584, 30.9%), and “multisystem morbidity” (n = 333, 17.6%). Compared with diabetes alone, the “multisystem morbidity” class had an increased association with global cognitive decline. All patterns of multimorbidity were associated with an increased risk of memory decline and disability; however, the “multisystem morbidity” group also had the strongest association and presented a higher ADL-IADL disability (ratio = 4.22, 95% CI = 2.52, 7.08) and decline in memory Z scores (β = −0.322, 95% CI = −0.550, −0.095, p = 0.0058).ConclusionSignificant longitudinal associations between different patterns of multimorbidity in diabetes patients and memory decline and disability were observed in this study. Future studies are needed to understand the underlying mechanisms and common risk factors for multimorbidity in diabetes patients and to propose treatments that are more effective

Licarin-B Exhibits Activity Against the Toxoplasma gondii RH Strain by Damaging Mitochondria and Activating Autophagy

Toxoplasma gondii is an obligate intracellular pathogen that infects warm-blooded animals and humans. However, side effects limit toxoplasmosis treatment, and new drugs with high efficiency and low toxicity need to be developed. Natural products found in plants have become a useful source of drugs for toxoplasmosis. In this study, twenty natural compounds were screened for anti-T. gondii activity by Giemsa staining or real-time fluorescence quantitative polymerase chain reaction (qPCR) in vitro. Among these, licarin-B from nutmeg exhibited excellent anti-T. gondii activity, inhibiting T. gondii invasion and proliferation in a dose-dependent manner, with an EC50 of 14.05 ± 3.96 μg/mL. In the in vivo, licarin-B treatment significantly reduced the parasite burden in tissues compared to no treatment, protected the 90% infected mice from to death at 50 mg/kg.bw. Flow cytometry analysis suggested a significant reduction in T. gondii survival after licarin-B treatment. Ultrastructural changes in T. gondii were observed by transmission electron microscopy (TEM), as licarin-B induced mitochondrial swelling and formation of cytoplasmic vacuoles, an autophagosome-like double-membrane structure and extensive clefts around the T. gondii nucleus. Furthermore, MitoTracker Red CMXRos, MDC, and DAPI staining showed that licarin-B promoted mitochondrial damage, autophagosome formation, and nuclear disintegration, which were consistent with the TEM observations. Together, these findings indicate that licarin-B is a promising anti-T. gondii agent that potentially functions by damaging mitochondria and activating autophagy, leading to T. gondii death

miR-100 Reverses Cisplatin Resistance in Breast Cancer by Suppressing HAX-1

Background/Aims: Breast cancer (BC) is the most common cancer in women worldwide. Despite great advancements in cancer therapy in recent years, surgery and chemotherapy are still the mainstays of BC treatment. However, cancer cells usually develop mechanisms to evade cell death induced by chemotherapy. Thus, strategies are needed to reverse the chemoresistance of cancer cells. Methods: We established cisplatin-resistant BC models in MDA-MB-231 and MCF-7 BC cell lines through long-term exposure to cisplatin. Quantitative reverse transcription PCR was used to examine the expression of microRNA (miR)-100. MTT cell viability assays were performed to determine cell viability. Regulation of hematopoietic cell-specific protein 1-associated protein X-l (HAX-1) targeted by miR-100 was confirmed by western blotting and luciferase reporter assays. The mitochondrial membrane potential and apoptosis were measured by flow cytometry. Release of cytochrome c from the mitochondria into the cytoplasm, HAX-1 expression, and activation of caspase-9 and caspase-3 were detected by western blotting. Results: A clear decrease in miR-100 expression was observed in cisplatin-resistant MDA-MB-231 and MCF-7 cells (MDA-MB-231/R and MCF-7/R). Overexpression of miR-100 increased the sensitivity of MDA-MB-231/R and MCF-7/R cells to cisplatin treatment and promoted cisplatin-induced mitochondrial apoptosis by targeting HAX-1 gene. Conclusions: MiR-100 targeted HAX-1 to increase the chemosensitivity of BC by mediating the mitochondrial apoptosis pathway

Agents: An Open-source Framework for Autonomous Language Agents

Recent advances on large language models (LLMs) enable researchers and developers to build autonomous language agents that can automatically solve various tasks and interact with environments, humans, and other agents using natural language interfaces. We consider language agents as a promising direction towards artificial general intelligence and release Agents, an open-source library with the goal of opening up these advances to a wider non-specialist audience. Agents is carefully engineered to support important features including planning, memory, tool usage, multi-agent communication, and fine-grained symbolic control. Agents is user-friendly as it enables non-specialists to build, customize, test, tune, and deploy state-of-the-art autonomous language agents without much coding. The library is also research-friendly as its modularized design makes it easily extensible for researchers. Agents is available at https://github.com/aiwaves-cn/agents.Comment: Code available at https://github.com/aiwaves-cn/agent

Gas geochemistry of the hot springs gas in Fujian province, SE China: insight into the deep faults and seismic activity

Fujian province is located at the forefront of the South China continental margin, situated on the edge of the Circum-Pacific seismic belt, and it is one of the regions with the most active neotectonic and geothermal activities in Chinese mainland. To explore the geochemical signals of hot spring gases to tectonic activity and earthquakes, a collection of geothermal gas samples was collected from 29 locations in Fujian from January 2021 to December 2022 (many of which were multiply collected at several sites quarterly). The gas samples were tested for their gas composition, helium, neon, carbon isotopes, radon contents, and gas flow rates. The results show that the dominant component of the hot spring outgassing is N2, and the increase in CO2 content is often associated with the increasing 13C. The variation range of the helium isotope ratio (3He/4He) in the hot spring gases is between 0.06 and 2.20Ra, and Rc/Ra varies between 0.06 and 1.58, with peak values occurring at the intersections of deep faults. Radon contents range from 18 to 2000 Bq/L. Calculations revealed that the maximum proportion of mantle-derived helium is 30.2%, and the mantle-derived heat contribution ranges from 37.6% to 63.4%. These data indicate a significant mantle degassing process in Fujian, with a high degree of mantle-crust connectivity, and mantle-derived heat as the main source of geothermal activity in the area. Comparative analysis with regional seismic activity indicates that areas with relatively strong upwelling of deep fluids are the main regions of regional seismic activity, and seismic intensity is positively correlated with mantle-derived heat flow. Thus, deep thermal fluid actives are closely genetically correlated to regional seismic activity. Additionally, the correlation analysis with the Taiwan ML6.0 earthquake suggests that high 3He/4He, δ13CCO2 values of hot spring gas and gas flow velocity in Nancheng Hot Spring (QZ6) indicate significant short-term and imminent anomaly indications preceding ML6.0 earthquakes in the Taiwan region

Case report: Application of morphology in the diagnosis of siderosis in a patient with tuberculosis infection

A 49-year-old male who had been working in welding for more than 30 years was admitted to the hospital for a medical checkup that revealed a lung shadow without specific symptoms such as coughing and sputum. Imaging studies showed diffuse ground-glass changes in both lungs, wall cavities with wall nodules, multiple peripheral nodules, and some nodules with calcification. The patient has been engaged in welding work for more than 30 years and exposed to iron dust. Lung tissue biopsy, routine morphological and pathological fluid basis examination of alveolar lavage fluid, can be considered as pulmonary iron particles, which can be regarded as iron dust lung. Acid-fast bacilli were detected in both fibrobronchoscopic brush extract and alveolar lavage fluid acid-fast staining. As the pathological examination revealed granulomatous inflammation showed caseation necrosis, the patient was judged to have concomitant pulmonary TB. After the diagnosis was made, the patient was no longer exposed to dust and was treated with appropriate anti- tuberculosis (TB) therapy. Lung lesions caused by welding have been reported, but the simultaneous finding of siderosis with pulmonary TB is specific to the case presented here. By describing the imaging features, combining different staining methods of alveolar lavage fluid and pathological examination of lung tissue, we showed various morphological manifestations of this case, aiming at improving the morphological diagnosis level of laboratory physicians and enabling patients to be diagnosed and treated early