Nitrogen-based fertilizers are crucial in agriculture for maintaining soil health and increasing crop yields. Soil microorganisms transform nitrogen from fertilizers into NO3−–N, which is absorbed by crops. However, some nitrogen is converted to nitrous oxide (N2O), a greenhouse gas with a warming potential about 300-times greater than carbon dioxide (CO2). Agricultural activities are the main source of N2O emissions. Monitoring N2O can enhance soil health and optimize nitrogen fertilizer use, thereby supporting precision agriculture. To achieve this, we developed ionic liquid-gated graphene field-effect transistor (FET) sensors to measure N2O concentrations in agricultural soil. We first fabricated and tested the electrical characteristics of the sensors. Then, we analyzed their transfer characteristics in our developed N2O evaluation system using different concentrations of N2O and air. The sensors demonstrated a negative shift in transfer characteristic curves when exposed to N2O, with a Dirac point voltage difference of 0.02 V between 1 and 10 ppm N2O diluted with pure air. These results demonstrate that the ionic liquid-gated graphene FET sensor is a promising device for N2O detection for agricultural soil applications.

Influenza, a highly pathogenic infectious disease, causes nearly half a million deaths annually worldwide. Thus, effective vaccine-based prevention and control are crucial. Although live attenuated influenza vaccines (LAIVs) can induce mucosal immunity, existing vaccines effectiveness remains relatively low, posing a significant threat to public health. Thus, we developed a novel mosaic H1N1 LAIV candidate by integrating mosaic antigen design with established LAIV technology. This vaccine incorporates most potential T-cell epitopes of hemagglutinin and neuraminidase antigens into an attenuated master donor strain, ensuring safety and broad immunity. We compared it with commercial monovalent attenuated and inactivated vaccines in mice. The mosaic H1N1 LAIV induced robust cross-reactive humoral and mucosal immune responses, enhanced antigen-specific cellular immunity, and established tissue-resident memory T and B cells in the respiratory tract. Challenge experiments confirmed its protective efficacy against homologous and heterologous strains. It provided complete protection against homologous strains with low epitope similarity and partial protection against the ancestral H3N2 virus. Our study highlights the mosaic H1N1 LAIV as an excellent universal vaccine candidate capable of inducing broad cross-reactive immune responses and providing robust protection against distinct influenza A viruses, demonstrating a promising strategy to address the limitations of current commercial vaccines.

The development of reliable and efficient sensors is essential for advances in health monitoring technologies. This study focused on the fabrication and evaluation of a multichannel printed sensor electrode designed for long-term stability and effective data acquisition. Using rapid printing technology, we created a urine sensor array with extended electrodes for the measurement of urine volume and frequency. The ultrathin design of the sensor electrode, with an average thickness of only 30 microns, ensures both user comfort and measurement accuracy. The sensor electrode dimensions were meticulously designed, measured, and optimized through successful trial manufacturing of the sensor electrode and sensor array. Comprehensive evaluation of the fabricated sensor demonstrated excellent performance, including a high response speed of ≤1 s and long-term stability exceeding 5 weeks. In addition, wireless transmission capabilities and user interfaces were developed for field experiments. Finally, animal experiments were performed to evaluate the field performance of the fabricated sensor. Accordingly, we are confident that the sensor developed herein will contribute to enhancing healthcare in an aging society.

ABSTRACTInfluenza B virus (IBV) causes significant seasonal disease burden, and frequent antigenic drift limits the effectiveness of conventional vaccines. To address this, we designed mosaic haemagglutinin (HA) and neuraminidase (NA) antigens to maximize T-cell epitope coverage and incorporated them into a nasal live attenuated influenza vaccine (LAIV) platform. Using B/Victoria lineage sequences (2009-2021), mosaic HA/NA candidates were generated via an iterative genetic algorithm. BALB/c mice were randomized into PBS, conventional inactivated influenza vaccine (IIV), conventional LAIV, and mosaic-LAIV (MoBV) groups, and immunized intranasally on days 0 and 14. Immune responses were evaluated by haemagglutination inhibition (HAI), microneutralization (MN), neuraminidase inhibition (NAI), mucosal IgA by ELISA, and T-cell profiling by flow cytometry. Protective efficacy was assessed by challenge with multiple IBV strains. MoBV-induced higher cross-reactive antibody responses (HAI, MN, NAI) and markedly increased mucosal IgA, which persisted for 100 days, alongside enhanced T-cell responses. Upon challenge, MoBV improved survival to 25-100% compared with controls. These results demonstrate that MoBV elicits broad systemic and mucosal immunity, providing robust cross-lineage protection against diverse IBV strains and supporting the development of a universal influenza B vaccine.

A compact, multi-channel ionic liquid-gated graphene field-effect transistor (FET) has been proposed and developed in our work for on-field continuous monitoring of nitrate nitrogen and other nitrogen fertilizers to achieve sustainable and efficient farming practices in agriculture. However, fabricating graphene FETs with easy filling of ionic liquids, minimal graphene defects, and high process yields remains challenging, given the sensitivity of these devices to processing conditions and environmental factors. In this work, two approaches for the fabrication of our graphene FETs were presented, evaluated, and compared for high yields and easy filling of ionic liquids. The process difficulties, major obstacles, and improvements are discussed herein in detail. Both devices, those fabricated using a 3 μm-thick CYTOP® layer for position restriction and volume control of the ionic liquid and those using a ~20 nm-thick photosensitive hydrophobic layer for the same purpose, exhibited typical FET characteristics and were applicable to various application environments. The research findings and experiences presented in this paper will provide important references to related societies for the design, fabrication, and application of liquid-gated graphene FETs.

Direct electrification from low-grade heat is becoming a research focus since those devices are simpler and less bulky in design and package. In our previous studies, we demonstrated a continuous current flow by filling a nanofluids consisting of dodecanethiol coated Au nanoparticles of 3-5 nm in diameter into an inter-electrode gap. Experiments showed that the gap thickness influences the performance of the device and theoretical analysis can relate this to interactions between the nanoparticles and strength variations of the electrical field. In this paper, we report on our efforts on design, fabrication, and evaluation of two types of gaps between metal electrodes of different work functions for the investigation of device performances as well as the operational mechanism. The merits, achievements, as well as process compatibilities of each design will be presented and discussed. The efforts and the results of this work may offer practice applicable nanomanufacturing approaches to fabricating submicron gaps for many other potential applications as well.

Early pressure injury (PI) progression is associated with multi-circulatory disorders and they interplay with each other, resulting in a lack of a satisfactory diagnostic method. We generated early PI and blanchable erythema hairless rat models. Transparent disc method and capillary refilling time test (CRTT) results were recorded with ultraviolet camera to capture the dynamics changes, and the blanching index and refilling index were set for comprehensive analysis. The deteriorated areas of early PI showed non-blanchable erythema (NBE) and an increase in erythema at 0.5 and 6 h with the transparent disc method. CRTT showed a marked refilling delay at 12 h. The comprehensive analysis of blanching index and refilling index showed a significant change in erythema from NBE at 0.5 h and ischemia progressing to hemorrhage at 18 h. There was also a marked difference in the deteriorating and improving areas within the same erythema. Pathological analysis showed inflammatory cell infiltration, with marked edema accompanied by increased hemorrhage and tissue necrosis. Furthermore, small arteries and veins with thrombosis and microthrombi were observed. Consistent ischemia after decompression and subsequent hemorrhage are important indicators, and comprehensive analysis can help increase the positive diagnosis rate over that for other circulatory disorders alone.

By depositing a resin, which is consist of dispersed metallic nanoparticles in an inert matrix material, between two parallel metal electrodes with different work functions, our previous work experimentally demonstrated a fully solid-state device for direct electrification from low grade heat. The device exhibited improved output power compared to the devices based on a liquid matrix. For better understanding underlying physics of the fully solid-state device as well as to explore its potential applications, electrical characteristic, load capacity, etc. of the device were investigated and evaluated for the duration of a few weeks, particularly at near environmental temperatures. In this paper, the latest evaluation results will be presented in detail and discussed herein, along with an application example of powering a LED light by using 4 pieces of 4-layer stacked devices.

In this letter, we successfully fabricated a micro-electromechanical systems (MEMS) Pirani sensor with a three-layer packaged structure. We fabricated sensors with different layer structures, heating resistors with different resistances, and different materials. Then, we comprehensively evaluated and compared their performances. The experimental results demonstrated that the proposed Pirani sensor can measure pressures ranging from 0.1 Pa to 10 kPa, exhibiting a high responsivity within the target operating range of 1–1000 Pa. With its well-packaged micromachined design, this MEMS Pirani sensor holds significant potential for the in situ monitoring of pressure variations in a wide range of applications.

Continuous body temperature measurement is an important means of studying inflammation and metabolic changes using experimental animals. Although expensive telemetry equipment for collecting multiple parameters is available for small animals, readily used devices for mediate- or large-sized animals are rather limited. In this study, we developed a new telemetry sensor system that can continuously monitor rabbit body temperature. The telemetry sensor was easily implanted subcutaneously in rabbits housed in the animal facility while temperature changes were continuously recorded by a personal computer. Temperature data obtained by the telemetry was consistent with the rectal temperature measured by a digital device. Analysis of body temperature changes of unstrained rabbits, either under the normal condition or fever induced by endotoxin confirms the reliability and usefulness of this system.

We have developed and evaluated ionic liquid-gated graphene field-effect transistor (FET) sensors as part of a precision farming for detecting nitrate nitrogen (N03-N) concentrations in agricultural soil. We began by fabricating and testing of basic characteristics the ionic liquid-gated graphene FET sensors. Next, we examined transfer characteristic curves of the sensors in the presence of vapors of NO 3 -N standard solution 0.2-mL in 10-L chamber by setting up a soil simulated system. The drain-source current $(\mathbf{I}_{\mathbf{ds}})$ at concentration of 100ppm and 1000ppm increased in both positive and negative directions from Dirac point. The Dirac point voltage shifted 0.1 V to the negative side as the NO 3 -N concentration increased from 100 ppm to 1000 ppm.

This study developed a rapid manufacturing approach for a moisture sensor based on contactless jet printing technology. A compact measurement system with ultrathin and flexure sensor electrodes was fabricated. The proposed sensor system focuses on continuous urine measurement, which can provide timely information on subjects to ensure efficient diagnosis and treatment. The obtained results verify that the proposed sensor system can exhibit a typical responsivity of up to −7.76 mV/%RH in the high-sensitivity range of 50–80 %RH. A preliminary field experiment was conducted on a hairless rat, and the effectiveness of the proposed ultrathin moisture sensor was verified. This ultrathin sensor electrode can be fabricated in the micrometer range, and its application does not affect the comfort of the user. The ultrathin electrode sensors can be printed directly on the diaper or undergarment of the user for in situ urine health monitoring, particularly of infants and the elderly.

This paper reports the development of a novel device with an ultra-thin gap filled with nanofluid in between two parallel metallic electrodes, which will allow, for the first time, practical applicable, affordable, and mass-producible direct thermoelectric energy generation at room temperature. Compared to the state of the art, the power density of our device exceeds conventional thermionic energy generators by orders of magnitude and may offer close to uW power in a volume of 1cm 3 thus making it attractive for IoT, wearable electronics and other standalone applications. In addition, our device is compatible with roll-to-roll and flexible glass processes for low-cost and large area production.

Acute respiratory infections are the most common illnesses experienced by people of all ages worldwide. Previous epidemiologic studies have shown that viruses cause most of these acute respiratory illnesses[1]. Among respiratory viruses,

In this study, we designed a microelectromechanical system (MEMS) Pirani vacuum sensor with a compact size. Specifically, the sensor was successfully fabricated based on the Pirani principle and using a commercial eight-inch MEMS foundry process. The sensor fabrication process was carried out using only four photomasks and the proposed sensor had an ultra-compact fabricated size (<2.2 × 2.2 mm2). A vacuum measurement system was set up to comprehensively evaluate the fabricated sensors. The results demonstrated that the MEMS Pirani vacuum sensor has a high responsivity in the low-pressure domain from 100 Pa. The proposed sensor with a 953.0-Ω heater exhibited an average responsivity of 11.9 mV/Pa in the preferred range of 100 to 7 Pa and 96.0 mV/Pa in the range of 7 to 1 Pa. The sensor may be potentially suitable in many applications, such as vacuum indicators for processing equipment, health monitoring systems for social infrastructure, and medical and health applications.

Seasonal influenza A (H3N2) virus has been a concern since its first introduction in humans in 1968. Accumulating antigenic changes in viral hemagglutinin (HA), particularly recent cocirculations of multiple HA genetic clades, allow H3N2 virus evade into humans annually. From 2010, the binding of neuraminidase (NA) to sialic acid made the traditional assay for HA inhibition antibodies (Abs) unsuitable for antigenicity characterization. Here, we investigated the serum anti-NA response in a cohort with a seroconversion of microneutralizing (MN) Abs targeting the circulating strain, A/Singapore/INFIMH-16-0019/2016 (H3N2, 3C.2a1)-like, a virus during 2018/2019 flu seasons. We discovered that MN Ab titers show no difference between children and adults. Nevertheless, higher titers of Abs with NA activity inhibition (NI) activity of 129 and seroconversion rate of 68.42% are presented in children aged 7-17 years (n = 19) and 73.47 and 41.17% in adults aged 21-59 years (n = 17), respectively. The MN Abs generated in children display direct correlations with HA- and NA-binding Abs or NI Abs. The NI activity exhibited cross-reactivity to N2 of H3N2 viruses of 2007 and 2013, commonly with 329-N-glycosylation and E344 in N2, a characteristic of earlier 3C.2a H3N2 virus in 2014. The percentage of such viruses pronouncedly decreased and was even replaced by those dominant H3N2 viruses with E344K and 329 non-glycosylation, which have a significantly low activity to the tested antisera. Our findings suggest that NI assay is a testable assay applied in H3N2 infection in children, and the antigenic drift of current N2 should be considered for vaccine selection.

Influenza vaccines represent the most effective preventive strategy to control influenza virus infections; however, adaptive mutations frequently occur in the hemagglutinin (HA) glycoprotein during the preparation of candidate vaccine virus and production of vaccine in embryonated eggs. In our previous study, we constructed candidate vaccine virus (HA-R) to match the highly pathogenic avian influenza H7N9 viruses A/Guangdong/17SF003/2016 as part of a pandemic preparedness program. However, mixed amino acids (R, G, and I) were presented at position 220 (H3 numbering) in HA during passage in embryonated eggs. The residue at position 220 is located close to the receptor-binding site and the biological characteristics of this site remain to be elucidated. Therefore, in this study, using reverse genetics, we constructed two viruses carrying the single substitution in position 220 of HA (HA-G and HA-I) and evaluated the biological effects of substitution (R with G/I) on receptor binding, neuraminidase (NA) activity, growth characteristics, genetic stability, and antigenicity. The results revealed both mutant viruses exhibited lower HA binding affinities to two receptor types (sialic acid in alpha2,3- and alpha2,6-linkage to galactose, P < 0.001) and significant better growth characteristics compared to HA-R in two cells. Moreover, under similar NA enzymatic activity, the two mutant viruses eluted more easily from agglutinated erythrocytes than HA-R. Collectively, these results implied the balance of HA and NA in mutant viruses was a stronger determinant of viral growth than the individual amino acid in the HA position 220 in HA-R without strong binding between HA and sialylated receptors. Importantly, both the substitutions conferred altered antigenicity to the mutant viruses. In conclusion, amino acid substitutions at position 220 can substantially influence viral biological properties.

Early pressure injury (PI) can result in either spontaneous healing (SH) or deterioration into ulcer (DU). However, determining whether PI will progress into SH or DU on the basis of non-blanchable erythema only is difficult. In this study, we constructed two animal PI models to mimic SH and DU injuries and observed haemorrhage by using ultraviolet (UV) photography to develop potential clinical indicators for predicting the progression of early PI. Macroscopy, UV photography, and skin temperature observations were obtained. In the SH group, macroscopic observation showed the erythema was obvious at 0.5 hours after decompression and faded gradually had almost disappeared at 72 hours. In the DU group, the erythema persisted, and an erosion appeared at 24 hours after decompression and expanded at 36 hours. The erythema developed into an obvious ulcer at 48 hours and enlarged at 72 hours. The obvious ulcer found at 48 hours through macroscopic observation was clearly visible at 36 hours with UV photography, and a significant difference in grey values between the two groups was found at as early as 18 hours (P < .05). This study provided evidence showing that UV photography can predict the different progression stages of early PI. Additionally, when combined with the transparent disc method, UV photography also can be used to identify the circulatory disorders of early PI, such as haemorrhage or hyperaemia and even congestion.

Laparoscopic surgery is less invasive to patients; however, fatal bleeding occurs when a surgeon misinterprets the anatomical location of the blood vessels. Therefore, we have proposed a location tracking system by generating an artificial magnetic field around a patient and attaching MEMS magnetic sensor nodes to certain locations of the patient's organs for real-time tracking of the organ shape and vessel locations. This paper presents the detailed system design and configuration. The results suggest that a high spatial resolution of 1-2 mm may be achieved by static and ultralow-frequency magnetic fields for rotation recognition of each sensor node and noise cancelation of the entire system. The algorithm for creating the navigation 'map' has been investigated from both efficiency and accuracy perspectives, which is essential for practical applications of the above system in surgical navigation. (c) 2021 IPEM. Published by Elsevier Ltd. All rights reserved.