Multifunctional Freestanding Microprobes for Potential Biological Applications.

Deep-level sensors for detecting the local temperatures of inner organs and tissues of an animal are rarely reported. In this paper, we present a method to fabricate multifunctional micro-probes with standard cleanroom procedures, using a piece of stainless-steel foil as the substrate. On each of the as-fabricated micro-probes, arrays of thermocouples made of Pd-Cr thin-film stripes with reliable thermal sensing functions were built, together with Pd electrode openings for detecting electrical signals. The as-fabricated sword-shaped freestanding microprobes with length up to 30 mm showed excellent mechanical strength and elastic properties when they were inserted into the brain and muscle tissues of live rats, as well as suitable electrochemical properties and, therefore, are promising for potential biological applications.

Deterministic Line-Shape Programming of Silicon Nanowires for Extremely Stretchable Springs and Electronics.

Line-shape engineering is a key strategy to endow extra stretchability to 1D silicon nanowires (SiNWs) grown with self-assembly processes. We here demonstrate a deterministic line-shape programming of in-plane SiNWs into extremely stretchable springs or arbitrary 2D patterns with the aid of indium droplets that absorb amorphous Si precursor thin film to produce ultralong c-Si NWs along programmed step edges. A reliable and faithful single run growth of c-SiNWs over turning tracks with different local curvatures has been established, while high resolution transmission electron microscopy analysis reveals a high quality monolike crystallinity in the line-shaped engineered SiNW springs. Excitingly, in situ scanning electron microscopy stretching and current-voltage characterizations also demonstrate a superelastic and robust electric transport carried by the SiNW springs even under large stretching of more than 200%. We suggest that this highly reliable line-shape programming approach holds a strong promise to extend the mature c-Si technology into the development of a new generation of high performance biofriendly and stretchable electronics.

Crystal Phase- and Orientation-Dependent Electrical Transport Properties of InAs Nanowires.

We report a systematic study on the correlation of the electrical transport properties with the crystal phase and orientation of single-crystal InAs nanowires (NWs) grown by molecular-beam epitaxy. A new method is developed to allow the same InAs NW to be used for both the electrical measurements and transmission electron microscopy characterization. We find both the crystal phase, wurtzite (WZ) or zinc-blende (ZB), and the orientation of the InAs NWs remarkably affect the electronic properties of the field-effect transistors based on these NWs, such as the threshold voltage (VT), ON-OFF ratio, subthreshold swing (SS) and effective barrier height at the off-state (ΦOFF). The SS increases while VT, ON-OFF ratio, and ΦOFF decrease one by one in the sequence of WZ ⟨0001⟩, ZB ⟨131⟩, ZB ⟨332⟩, ZB ⟨121⟩, and ZB ⟨011⟩. The WZ InAs NWs have obvious smaller field-effect mobility, conductivities, and electron concentration at VBG = 0 V than the ZB InAs NWs, while these parameters are not sensitive to the orientation of the ZB InAs NWs. We also find the diameter ranging from 12 to 33 nm shows much less effect than the crystal phase and orientation on the electrical transport properties of the InAs NWs. The good ohmic contact between InAs NWs and metal remains regardless of the variation of the crystal phase and orientation through temperature-dependent measurements. Our work deepens the understanding of the structure-dependent electrical transport properties of InAs NWs and provides a potential way to tailor the device properties by controlling the crystal phase and orientation of the NWs.

Whole-journey nanomaterial research in an electron microscope: from material synthesis, composition characterization, property measurements to device construction and tests.

The whole-journey nanomaterial research from material synthesis, composition and structure characterizations, property measurements to device construction and tests in one equipment chamber provides a quick and unambiguous way of establishing the relationships between synthesis conditions, composition and structures, physical properties and nanodevice performances of nanomaterials; however, it still proves challenging. Herein, we report the whole-journey research of tungsten oxide nanowires in an environmental scanning electron microscope (ESEM) equipped with an x-ray energy dispersive spectrometer (EDS) and a multifunctional nanoprobe system. Tungsten oxide nanowires are synthesized by irradiating a tungsten filament using a high-energy laser in O2 atmosphere with the dynamic growth processes of nanowires being directly visualized under ESEM observation. The as-synthesized nanowires are then characterized to be monoclinic W18O49 nanowires by combing in situ EDS and ex situ transmission electron microscopy. Important physical parameters, i.e. Young's modulus, breaking strength, and electrical conductivity, of W18O49 nanowires are determined based on in situ property measurements. Two-terminal electronic devices employing single W18O49 nanowires as the channel are in situ constructed and their performances as near-infrared photodetectors and water vapor sensors are studied. The whole-journey research establishes the relationships between synthesis conditions, composition and structures, physical properties and nanodevice performances of tungsten oxide nanowires, and can be applied to other nanomaterials.

Learning-Based Control for Soft Robot-Environment Interaction with Force/Position Tracking Capability.

Soft robotics promises to achieve safe and efficient interactions with the environment by exploiting its inherent compliance and designing control strategies. However, effective control for the soft robot-environment interaction has been a challenging task. The challenges arise from the nonlinearity and complexity of soft robot dynamics, especially in situations where the environment is unknown and uncertainties exist, making it difficult to establish analytical models. In this study, we propose a learning-based optimal control approach as an attempt to address these challenges, which is an optimized combination of a feedforward controller based on probabilistic model predictive control and a feedback controller based on nonparametric learning methods. The approach is purely data-driven, without prior knowledge of soft robot dynamics and environment structures, and can be easily updated online to adapt to unknown environments. A theoretical analysis of the approach is provided to ensure its stability and convergence. The proposed approach enabled a soft robotic manipulator to track target positions and forces when interacting with a manikin in different cases. Moreover, comparisons with other data-driven control methods show a better performance of our approach. Overall, this work provides a viable learning-based control approach for soft robot-environment interactions with force/position tracking capability.

Impacts of cefalexin on nitrite accumulation, antibiotic degradation, and microbial community structure in nitrification systems.

The intensive use of various antibiotics for clinical and agricultural purposes has resulted in their widespread use in wastewater treatment plants. However, little research has been conducted on the effects of antibiotics on nitrite accumulation, antibiotic degradation pathways, or the microbial community structure in nitrification systems. In this study, a laboratory-scale sequencing batch reactor was used to treat wastewater containing cefalexin (CFX) at different doses (5, 10, 15, and 20 mg/L). The results showed that the nitrification performance was gradually inhibited with increasing CFX concentration. Ammonia-oxidizing bacteria (AOB) are more tolerant to CFX than nitrite-oxidizing bacteria (NOB). Under 15 mg/L of CFX, NOB were completely suppressed, whereas AOB were partially inhibited, as evidenced by an ammonium removal efficiency of 60 % and a 90 % of nitrite accumulation ratio. The partial nitritation was achieved. CFX can be degraded into 2-hydroxy-3phenylpyrazine and cyclohexane through bacterial co-metabolism, and CFX degradation gradually diminishes with decreasing nitrification performance. The abundance of Nitrospira gradually decreased with increasing CFX concentration. Ferruginibacter, Hydrogenophaga, Thauera, and Pseudoxanthomonas were detected at relative abundances of 13.2 %, 0.4 %, 0.9 %, and 1.3 %, respectively, indicating their potential roles in antibiotic degradation. These findings provide insight into the interactions between antibiotics and microbial communities, which are beneficial for a better understanding of antibiotic degradation in nitrification systems.

Numerical and experimental study on monitoring coal cracks with PZT sensor.

The rupture of coal pillar can lead to spontaneous combustion or collapse of goaf, which endangers the safety of workers. To explore the relationship between the crack depth of the coal structure and the signal received by the piezoelectric ceramic sensor, the output data of coal samples were analyzed by using the piezoelectric effect, combined with the experiment and ABAQUS simulation. Based on the signal amplitude, the output signal characteristics of the coal model with different crack depths were analyzed, and the evaluation index of coal crack cracking degree (Dc) was defined. The results show that the piezoelectric fluctuation method can effectively identify the local cracks of coal. When the distance between the lead Piezoelectric Transducer (PZT) patch and crack position is constant, the amplitude of the PZT patch output signal will decay with the deepening of the crack depth, while the value of increases with the increase of crack depth. This study provides a theoretical basis for mine disaster prevention and control.

Blood purification for treatment of non-liquefied multiple liver abscesses and improvement of T-cell function: A case report.

BACKGROUND: Non-liquefied multiple liver abscesses (NMLA) can induce sepsis, septic shock, sepsis-associated kidney injury (SA-AKI), and multiple organ failure. The inability to perform ultrasound-guided puncture and drainage to eradicate the primary disease may allow for the persistence of bacterial endotoxins and endogenous cytokines, exacerbating organ damage, and potentially causing immunosuppression and T-cell exhaustion. Therefore, the search for additional effective treatments that complement antibiotic therapy is of great importance. CASE SUMMARY: A 45-year-old critically ill female patient presented to our hospital's intensive care unit with intermittent vomiting, diarrhea, and decreased urine output. The patient exhibited a temperature of 37.8 °C. Based on the results of liver ultrasonography, laboratory tests, fever, and oliguria, the patient was diagnosed with NMLA, sepsis, SA-AKI, and immunosuppression. We administered antibiotic therapy, entire care, continuous renal replacement therapy (CRRT) with an M100 hemofilter, and hemoperfusion (HP) with an HA380 hemofilter. The aforementioned treatment resulted in a substantial reduction in disease severity scores and a decrease in the extent of infection and inflammatory factors. In addition, the treatment stimulated the expansion of the cluster of differentiation 8+ (CD8+) T-cells and led to the complete recovery of renal function. The patient was discharged from the hospital. During the follow-up period of 28 d, she recovered successfully. CONCLUSION: Based on the entire therapeutic regimen, the early combination of CRRT and HP therapy may control sepsis caused by NMLA and help control infections, reduce inflammatory responses, and improve CD8+ T-cell immune function.

Occurrence of microplastic pollution in rivers globally: Driving factors of distribution and ecological risk assessment.

Microplastics, as global emerging pollutants, have received significant attention worldwide due to their ubiquitous presence in the rivers. However, there is still a lack of clarity on the occurrence, driving factors, and ecological risks of microplastics in rivers worldwide. In this study, a global microplastic dataset based on 862 water samples and 445 sediment samples obtained from 63 articles was constructed, which revealed the temporal and spatial distribution of abundance and morphological characteristics of microplastics in rivers across the globe. In global rivers, the abundance of MPs in both water and sediment spans across 10 and 4 orders of magnitude, respectively. The MP comprehensive diversity index based on the physical morphological characteristics of MPs indicated a significant positive correlation between the pollution sources of MPs in different environmental media. Based on the data was aligned to the full-scale MPs, a novel framework was provided to evaluate the ecological risk of MPs and the interaction effects between the influencing factors driving the distribution characteristics of MPs in rivers around the world. The results obtained demonstrated a wide variation in the key driving factors affecting the distribution of microplastics in different environmental media (water and sediment) in rivers globally. The diversity indices of the morphological characteristics of MPs in densely populated areas of lower-middle income countries in Asia were significantly higher, implying that the sources of microplastics in these regions are more complex and extensive. More than half of the rivers are exposed to potential ecological risks of MPs; however, microplastics may pose only immediate risks to aquatic species in Burigang River, Bangladesh. This can provide valuable insights for formulating more effective scientific strategies for the management of MP pollution in rivers.

Design and Synthesis of Functional Silane-Based Silicone Resin and Application in Low-Temperature Curing Silver Conductive Inks.

In the field of flexible electronics manufacturing, inkjet printing technology is a research hotspot, and it is key to developing low-temperature curing conductive inks that meet printing requirements and have suitable functions. Herein, methylphenylamino silicon oil (N75) and epoxy-modified silicon oil (SE35) were successfully synthesized through functional silicon monomers, and they were used to prepare silicone resin 1030H with nano SiO2. 1030H silicone resin was used as the resin binder for silver conductive ink. The silver conductive ink we prepared with 1030H has good dispersion performance with a particle size of 50-100 nm, as well as good storage stability and excellent adhesion. Additionally, the printing performance and conductivity of the silver conductive ink prepared with n,n-dimethylformamide (DMF): proprylene glycol monomethyl ether (PM) (1:1) as solvent are better than those of the silver conductive ink prepared by DMF and PM solvent. Cured at a low temperature of 160 °C, the resistivity of 1030H-Ag-82%-3 conductive ink is 6.87 × 10-6 Ω·m, and that of 1030H-Ag-92%-3 conductive ink is 0.564 × 10-6 Ω·m, so the low-temperature curing silver conductive ink has high conductivity. The low-temperature curing silver conductive ink we prepared meets the printing requirements and has potential for practical applications.

Inorganic Skeleton Reinforcement-A Generic Approach to Improve the Mechanical Properties of Biochar.

Biochar is considered as a promising candidate for emerging sustainable energy systems and environmental technology applications. However, the improvement of mechanical properties remains challenges. Herein, we propose a generic strategy to enhance the mechanical properties of bio-based carbon materials through inorganic skeleton reinforcement. As a proof-of-concept, silane, geopolymer, and inorganic gel are selected as precursors. The composites' structures are characterized and an inorganic skeleton reinforcement mechanism is elucidated. Specifically, two types of reinforcement of the silicon-oxygen skeleton network formed in situ with biomass pyrolysis and the silica-oxy-al-oxy network are constructed to improve the mechanical properties. A significant improvement in mechanical strength was achieved for bio-based carbon materials. The compressive strength of well-balanced porous carbon materials modified by silane can reach up to 88.9 kPa, geopolymer-modified carbon material exhibits an enhanced compressive strength of 36.8 kPa, and that of inorganic-gel-polymer-modified carbon material is 124.6 kPa. Moreover, the prepared carbon materials with enhanced mechanical properties show excellent adsorption performance and high reusability for organic pollutant model compound methylene blue dye. This work demonstrates a promising and universal strategy for enhancing the mechanical properties of biomass-derived porous carbon materials.

Robust superhydrophobic silicone/epoxy functional coating with excellent chemical stability and self-cleaning ability.

Superhydrophobic surfaces have attracted broad attention because of their unique water repellency but are restricted by poor wear resistance, weak adhesion to the substrate, and complex fabrication processes. Herein, a double-layer coating strategy consisting of the amino fluorine-silicone resin/epoxy resin (AFSR/EP) system is created. The system features a high hardness and transparent hydrophobic interface adhesive layer through the amine-epoxy "click" chemical reaction. The environmentally friendly resin system and low-cost nano-silica particles (n-SiO2) are composited and sprayed onto the substrate surface to form a superhydrophobic layer with outstanding robustness and excellent environmental stability. The prepared AFSR/EP@n-SiO2 composite coatings have a water contact angle of 161.1° and a sliding angle of 3.4°, demonstrating high superhydrophobic properties. Benefitting from the complementary advantages of silicone/epoxy resin, the prepared composite coatings maintain remarkable water repellency after various harsh environmental tests, including cyclic mechanical abrasion and tape-stripping, acid-base (pH 1 and pH 14) treatment, 10 wt% NaCl (pH 7) salt solution immersion, temperature treatment, knife scratching, and long-term ultraviolet radiation treatment, showing reinforced mechanical robustness and durable anti-corrosion stability. Notably, surface hardness of 5H and optical transparency over 80% can be achieved. The simple method offers a novel approach for the large-scale preparation of multifunctional superhydrophobic coatings.

Comparative Characterization of Volatile Compounds of Ningxiang Pig, Duroc and Their Crosses (Duroc × Ningxiang) by Using SPME-GC-MS.

With the aim to study the flavor characteristics of Ningxiang pigs (NX), Duroc (DC) pigs, and their crosses (Duroc × Ningxiang, DN), electronic nose and gas chromatography-mass spectrometry analysis were used to detect the volatile flavor substances in NX, DC, and DN (n = 34 pigs per population). A total of 120 volatile substances were detected in the three populations, of which 18 substances were common. Aldehydes were the main volatile substances in the three populations. Further analysis revealed that tetradecanal, 2-undecenal, and nonanal were the main aldehyde substances in the three kinds of pork, and the relative content of benzaldehyde in the three populations had significant differences. The flavor substances of DN were similar to that of NX and showed certain heterosis in flavor substances. These results provide a theoretical basis for the study of flavor substances of China local pig breeds and new ideas for pig breeding.

Influence of planting methods and organic amendments on rice yield and bacterial communities in the rhizosphere soil.

A comprehensive understanding of rice cultivation techniques and organic amendments affecting soil quality, enzyme activities and bacterial community structure is crucial. We investigated two planting methods (direct seeding and transplanting) of paddy rice (Oryza sativa) and organic amendments with rice straw and biochar on crop yield and soil biological and physicochemical properties. Rhizosphere bacterial communities at the maturity stage of rice growth were characterized through high-throughput 16S rRNA sequencing. Soil biochemical properties and enzyme activity levels were analyzed. Grain yield of paddy rice with transplanting increased 10.6% more than that with direct seeding. The application of rice straw increased grain yield by 7.1 and 8.2%, more than with biochar and the control, respectively. Compared to biochar and the control, the application of rice straw significantly increased sucrase, cellulase, protease, organic carbon, available phosphorus, nitrate, and ammonium. The application of biochar increased microbial biomass nitrogen and carbon, urease, pH, available nitrogen, and available potassium compared to the application of rice straw and the control. Principal coordinate analysis and dissimilarity distances confirmed significant differences among the microbial communities associated with planting methods and organic amendments. Bacteroidetes, Nitrospirae, Firmicutes, and Gemmatimonadetes abundance increased with rice straw relative to biochar and the control. The biochar addition was associated with significant increases in Chloroflexi, Patescibacteria, Proteobacteria, and Actinobacteria abundance. Pearson's correlation analyzes showed that Chloroflexi, Bacteroidetes and Nitrospirae abundance was positively correlated with grain yield. The relative abundance of these bacteria in soil may be beneficial for improving grain yield. These results suggest that planting methods and organic amendments impact soil biochemical characteristics, enzyme activity levels, and microbial community composition.

SARS-CoV-2-specific CD4+ T cells are associated with long-term persistence of neutralizing antibodies.

Understanding the decay and maintenance of long-term SARS-CoV-2 neutralizing antibodies in infected or vaccinated people and how vaccines protect against other SARS-CoV-2 variants is critical for assessing public vaccination plans. Here, we measured different plasm antibody levels 2 and 12 months after disease onset, including anti-RBD, anti-N, total neutralizing antibodies, and two neutralizing-antibody clusters. We found that total neutralizing antibodies declined more slowly than total anti-RBD and anti-N IgG, and the two neutralizing-antibody clusters decayed even more slowly than total neutralizing antibodies. Interestingly, the level of neutralizing antibodies at 12 months after disease onset was significantly lower than that at 2 months but more broadly neutralized SARS-CoV-2 variants, including Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1), Delta (B.1.617.2), and Lambda (C.37). Significant immune escape by the Omicron variant (B.1.1.529) was also observed 2 months post-recovery. Furthermore, we revealed that a high percentage of virus-specific CD4+ T cells and cTfh1 were associated with a slower decline in humoral immunity, accompanied by higher levels of CXCR3 ligands such as CXCL9 and CXCL10, higher frequency of cTfh1, and lower levels of cTfh2 and cTfh17. Our data highlight the importance of coordinating T-cell and humoral immunity to achieve long-term protective immunity.

QTL Detection for Rice Grain Length and Fine Mapping of a Novel Locus qGL6.1.

BACKGROUND: Grain length (GL) that is directly associated with appearance quality is a key target of selection in rice breeding. Although abundant quantitative trait locus (QTL) associated with GL have been identified, it was still relatively weak to identify QTL for GL from japonica genetic background, as the shortage of japonica germplasms with long grains. We performed QTLs analysis for GL using a recombinant inbred lines (RILs) population derived from the cross between japonica variety GY8 (short grains) and LX1 (long grains) in four environments. RESULTS: A total of 197 RILs were genotyped with 285 polymorphic SNP markers. Three QTLs qGL5.3, qGL6.1 and qGL11 were detected to control GL by individual environmental analyses and multi-environment joint analysis. Of these, a major-effect and stable QTL qGL6.1 was identified to be a novel QTL, and its LX1 allele had a positive effect on GL. For fine-mapping qGL6.1, a BC1F2 population consisting of 2,487 individuals was developed from a backcross between GY8 and R176, one line with long grain. Eight key informative recombinants were identified by nine kompetitive allele specific PCR (KASP) markers. By analyzing key recombinants, the qGL6.1 locus was narrowed down to a 40.41 kb genomic interval on chromosome 6. One candidate gene LOC_Os06g43304.1 encoding cytochrome P450 (CYP71D55) was finally selected based on the difference in the transcriptional expression and variations in its upstream and downstream region. CONCLUSIONS: Three QTLs qGL5.3, qGL6.1 and qGL11 were identified to control grain length in rice. One novel QTL qGL6.1 was fine mapped within 40.41 kb region, and LOC_Os06g43304.1 encoding cytochrome P450 (CYP71D55) may be its candidate gene. We propose that the further cloning of the qGL6.1 will facilitate improving appearance quality in japonica varieties.

Interface Engineering of Flexible Piezoresistive Sensors via Near-Field Electrospinning Processed Spacer Layers.

The interface contact between the active material and its neighboring metal electrodes dominates the sensing response of mainstream high-sensitivity piezoresistive pressure sensors. However, the properties of such interface are often difficult to control and preserve owing to the limited strategies to precisely engineer the surface structure and mechanical property of the active material. Here, a top-down fabrication method to create a grid-like polyurethane fiber-based spacer layer at the interface between a piezoresistive layer and its contact electrodes is proposed. The tuning of the period and thickness of the spacer layer is conveniently achieved by a programmable near-field electrospinning process, and the influence of the spacer structure on the sensing performance is systematically investigated. The sensor with the optimized spacer layer shows a widened sensing range (230 kPa) while maintaining a high sensitivity (1.91 kPa-1 ). Furthermore, the output current fluctuation of the sensors during a 74 000-cycle test is drastically reduced from 14.28% (without a spacer) to 3.63% (with a spacer), demonstrating greatly enhanced long-term reliability. The new near-field electrospinning-based strategy is capable of tuning sensor responses without changing the active material, providing a universal and scalable path to engineer the performances of contact-dominant sensors.

Fire behaviors along timber linings affixed to tunnel walls in mines.

Timber linings are applied as primary supports in the tunnel fault and fracture zones of mines. These linings are essential to prevent broken rock from falling during the occurrence of exogenous fires. In this study, experiments and numerical simulations were carried out using a fire dynamics simulator to investigate the flame-spread rate, flame characteristics, smoke movement, and spread process of timber-lining fires under different wind speeds of 0, 0.25, 0.5, and 0.75 m/s. It was found that cross-section flame spreading follows the three-stage sidewall-ceiling-sidewall pattern. Moreover, the average flame-spread rate increases along the vertical flame-spreading direction and decreases when the flame reaches the timber-lining corners. Moreover, the flame lengths underneath the timber-lining ceiling in the x-direction are longer than those in the y-direction. As the wind speed increases, the normalized flame lengths R(f) in the two directions decrease, and the maximum temperature underneath the ceiling decreases. In addition, the maximum temperature in the three tunnel sections of interest is first recorded in the tunnel cross-section in the initial fire stage. Higher wind speeds correspond to farther distances of the maximum-temperature points of the three timber-lining sections from the fire source.

Soil bacterial community as impacted by addition of rice straw and biochar.

The application of straw and biochar can effectively improve soil quality, but whether such application impacts paddy soil bacterial community development remains to be clarified. Herein, the impacts of three different field amendment strategies were assessed including control (CK) treatment, rice straw (RS) application (9000 kg ha-1), and biochar (BC) application (3150 kg ha-1). Soil samples were collected at five different stages of rice growth, and the bacterial communities therein were characterized via high-throughput 16S rDNA sequencing. The results of these analyses revealed that soil bacterial communities were dominated by three microbial groups (Chloroflexi, Proteobacteria and Acidobacteria). Compared with the CK samples, Chloroflexi, Actinobacteria, Nitrospirae and Gemmatimonadetes levels were dominated phyla in the RS treatment, and Acidobacteria, Actinobacteria, Nitrospirae and Patescibacteria were dominated phyla in the BC treatment. Compared with the RS samples, Chloroflexi, Acidobacteria, Actinobacteria, and Verrucomicrobia levels were increased, however, Proteobacteria, Gemmatimonadetes, Nitrospirae, and Firmicute levels were decreased in the BC samples. Rhizosphere soil bacterial diversity rose significantly following RS and BC amendment, and principal component analyses confirmed that there were significant differences in soil bacterial community composition among treatment groups when comparing all stages of rice growth other than the ripening stage. Relative to the CK treatment, Gemmatimonadaceae, Sphingomonadaceae, Thiovulaceae, Burkholderiaceae, and Clostridiaceae-1 families were dominant following the RS application, while Thiovulaceae and uncultured-bacterium-o-C0119 were dominant following the BC application. These findings suggest that RS and BC application can improve microbial diversity and richness in paddy rice soil in Northeast China.

Exposure to SARS-CoV-2 generates T-cell memory in the absence of a detectable viral infection.

T-cell immunity is important for recovery from COVID-19 and provides heightened immunity for re-infection. However, little is known about the SARS-CoV-2-specific T-cell immunity in virus-exposed individuals. Here we report virus-specific CD4+ and CD8+ T-cell memory in recovered COVID-19 patients and close contacts. We also demonstrate the size and quality of the memory T-cell pool of COVID-19 patients are larger and better than those of close contacts. However, the proliferation capacity, size and quality of T-cell responses in close contacts are readily distinguishable from healthy donors, suggesting close contacts are able to gain T-cell immunity against SARS-CoV-2 despite lacking a detectable infection. Additionally, asymptomatic and symptomatic COVID-19 patients contain similar levels of SARS-CoV-2-specific T-cell memory. Overall, this study demonstrates the versatility and potential of memory T cells from COVID-19 patients and close contacts, which may be important for host protection.