Miniaturized photoacoustic microscope for multi-segmental spinal cord imaging in freely moving mice.

Long-term and non-narcotic hemodynamic imaging is indispensable for observing factual physiological information of the spinal cord. Unfortunately, achieving label-free, high-resolution, and widefield spinal cord imaging for mice under freely moving conditions is challenging. In this study, we developed a miniaturized photoacoustic microscope along with a corresponding photoacoustic spinal window to realize high-resolution, multi-segmental hemodynamic imaging of the spinal cord for freely moving mice. The microscope has an outer size of 32 mm × 23 mm × 10 mm, a weight of 5.8 g, and a 4.4 µm lateral resolution within an effective field of view (FOV) of 2.6 mm × 1.8 mm. To eliminate the off-focus phenomena during spinal imaging, the microscope is equipped with a miniature motor to adapt the focal plane. Besides, the microscope is slidable along a customized rail on the window to expand the FOV. We evaluated the stability of the microscope and analyzed vascular images of the spinal cord under various physiological states. The results suggest that the microscope is capable of performing stable, multi-segmental spinal cord imaging in freely moving mice, offering new insights into spinal cord hemodynamics and neurovascular coupling research.

Elevated Th17 cells are associated with cardiovascular complications in ankylosing spondylitis.

OBJECTIVE: Patients with ankylosing spondylitis (AS) carry an increased burden of cardiovascular diseases (CVD), but features denoting the development of CVD in AS are unclear. This study aimed to evaluate the percentage and absolute number of lymphocytes and CD4+T cells in AS patients complicated with CVD (AS-CVD) and determine whether circulating T helper 17 (Th17) cells are associated with the development of CVD in AS. METHOD: A total of 117 AS patients (46 had CVD and 71 had no CVD) were enrolled in this retrospective study. The percentage and absolute number of lymphocytes and CD4+T cells were determined by flow cytometry. Associations between CVD and clinical markers were analysed using logistic regression. RESULTS: The ratio of Th17/Treg cells (0.30 vs 0.19, P = 0.014) and the absolute number of Th17 cells (7.27 cells/µL vs 4.34 cells/µL, P < 0.001) was significantly elevated in AS-CVD group compared with AS-no-CVD group. Multivariate logistic regression revealed that elevated Th17 cells (OR = 1.20, P = 0.016) were associated with CVD complications in AS. Receiver operating characteristic (ROC) curves showed a contribution of Th17 cell for distinguishing AS patients with CVD, with the areas under the ROC curve (AUCs) of 0.729 (95% CI: 0.632, 0.825, P < 0.001). CONCLUSION: Our findings provide evidence for the association between Th17 cells and increased cardiovascular risk in AS. Th17 cells may contribute to accelerated atherogenesis and increased cardiovascular burden in AS and be valuable for early assessment and management of AS-CVD.

Bioaccessibility of Metals in Soils at Typical Legacy Industrial Sites: In Vitro Evaluation Using Physiologically-Based Extraction.

Risk assessment of soil metal pollution based on total metal contents might give overestimates by neglecting the bioaccessibility of the pollutants to soil biota. Physiologically-based extraction tests (PBET) are in vitro methods for evaluation of bioaccessibility of soil pollutants. A total of 27 soil samples collected from four types of legacy industrial site representing metal smelting, lead-acid battery factories, chemical plants and steel plants were analyzed for the bioaccessibility of six potentially toxic metals using a PBET method. The metal pollutants at the industrial sites depended on the former industrial processes and emissions. The highest proportions of gastric phase and intestinal phase in these soil samples were 43.9% for Cd and 27% for Cu, respectively. Factors affecting metal bioaccessibility included type of industry and soil properties. The soils at a lead-acid battery factory showed relatively high bioaccessibility of Pb, Zn and Cd and those at the steel plant showed relatively low metal bioaccessibility. Soil organic matter and clay contents were positively related to metal bioaccessibility but soil pH and CEC showed negative relationships. Further studies are recommended to determine the speciation of the bioaccessible metals in these soils.

Reduction of peripheral regulatory T cells in active rheumatoid arthritis patients with coronary artery disease.

OBJECTIVE: To identify lymphocyte and CD4 + T cell subset characteristics, particularly regulatory T cells (Tregs), in active rheumatoid arthritis (RA) patients with coronary artery disease (CAD). METHODS: A total of 54 RA patients with CAD (RA-CAD group), 43 RA patients without CAD (pure RA group), and 43 healthy controls (HC group) were enrolled. The absolute number and frequency of lymphocyte subpopulations and CD4 + T cell subsets were analyzed by flow cytometry. Serum levels of cytokines were analyzed using a cytometric bead array. Clinical and laboratory data were collected retrospectively and their correlation with CD4 + T subsets were analyzed. RESULTS: There was a significant decrease in the absolute number of Treg cells (CD4 + CD25 + Foxp3 + T cells) in the RA-CAD group compared to the pure RA group (p < 0.001). Similarly, both the absolute number (p = 0.001) and frequency (p = 0.011) of Tregs in the RA-CAD group were decreased compared to the HCs, causing a Th17/Treg imbalance (p = 0.044). No difference was found in the absolute number and frequency of Treg cells between the pure RA and HC groups. However, the absolute Th17 cell count was increased in the pure RA group (p = 0.032). The serum level of cytokine IL-17 was lower in the RA-CAD group than in the pure RA group (p = 0.023). In the RA-CAD group, the Treg number was negatively correlated with the RA disease activity score and ESR value, and LDL and ApoB100 levels were negatively correlated with the number of Th17 cells. CONCLUSIONS: Active RA patients with CAD sustain more severe immune tolerance damage and Th17/Treg disorder. Monitoring of lymphocyte and CD4 + T cell subsets, particularly Treg cells, is crucial to understanding immune status in this group. Focusing on RA activity and CAD risk control, immune-regulatory therapy based on the Treg level may be more beneficial for RA patients with CAD.

Increased Serum Interleukin-2 Levels Are Associated with Abnormal Peripheral Blood Natural Killer Cell Levels in Patients with Active Rheumatoid Arthritis.

OBJECTIVE: To investigate the relationship between serum interleukin-2 (IL-2) levels and disease activity, absolute numbers of peripheral lymphocyte subsets, autoantibodies, and associated cytokines in patients with rheumatoid arthritis (RA). METHODS: This study included 106 patients with RA, evaluated their disease activity (DAS28 score), and divided them into disease remission (DAS28 ≤ 2.6), low disease activity (DAS28 ≤ 3.2), and moderate-high disease activity (DAS28 > 3.2) groups. Flow cytometry was used to detect the absolute numbers of peripheral lymphocyte subpopulations and CD4+ T cell subsets in each group, and serum cytokine levels were measured using cytometric bead array. RESULTS: Serum IL-2 levels in RA patients were positively correlated with disease activity and rheumatoid factor titers (p < 0.001 and p = 0.045, respectively), and multiple regression analysis revealed that serum IL-2 levels were an independent factor affecting disease activity. Serum IL-2 levels were positively correlated with Th17/Treg ratios (p = 0.013). Compared with the remission group, peripheral lymphocyte and CD4+ T lymphocyte subsets in patients with active RA decreased to varying degrees; however, the numbers of peripheral natural killer (NK) cells were significantly higher in the moderate-high disease activity group than in the remission (p = 0.046) and low disease activity (p = 0.020) groups; the percentages of NK cells had the same trend. In addition, the number and percentage of NK cells were positively correlated with serum IL-2 levels (p = 0.018 and p = 0.006, respectively). CONCLUSIONS: In RA patients, serum IL-2 levels were not only correlated with patients' disease activity and autoantibody levels but were also involved in their Th17/Treg immune imbalance. In addition, in patients with active RA, NK cell levels were abnormally elevated, possibly due to high serum levels of IL-2.

Four-dimensional key design in amplitude, phase, polarization and distance for optical encryption based on polarization digital holography and QR code.

We demonstrate that all parameters of optical lightwave can be simultaneously designed as keys in security system. This multi-dimensional property of key can significantly enlarge the key space and further enhance the security level of the system. The single-shot off-axis digital holography with orthogonal polarized reference waves is employed to perform polarization state recording on object wave. Two pieces of polarization holograms are calculated and fabricated to be arranged in reference arms to generate random amplitude and phase distribution respectively. When reconstruction, original information which is represented with QR code can be retrieved using Fresnel diffraction with decryption keys and read out noise-free. Numerical simulation results for this cryptosystem are presented. An analysis on the key sensitivity and fault tolerance properties are also provided.

High spatiotemporal mapping of cortical blood flow velocity with an enhanced accuracy.

Cerebral blood flow velocity is one of the most essential parameters related to brain functions and diseases. However, most existing mapping methods suffer from either inaccuracy or lengthy sampling time. In this study, we propose a particle-size-related calibration method to improve the measurement accuracy and a random-access strategy to suppress the sampling time. Based on the proposed methods, we study the long-term progress of cortical vasculopathy and abnormal blood flow caused by glioma, short-term variations of blood flow velocity under different anesthetic depths, and cortex-wide connectivity of the rapid fluctuation of blood flow velocities during seizure onset. The experimental results demonstrate that the proposed calibration method and the random-access strategy can improve both the qualitative and quantitative performance of velocimetry techniques and are also beneficial for understanding brain functions and diseases from the perspective of cerebral blood flow.

Differential immunological profiles in seronegative versus seropositive rheumatoid arthritis: Th17/Treg dysregulation and IL-4.

Background: Rheumatoid arthritis (RA) is an autoimmune disease with various subtypes. Among these, seronegative rheumatoid arthritis (SnRA), distinguished by its distinctive seronegative antibody phenotype, presents clinical diagnosis and treatment challenges. This study aims to juxtapose the immunological features of SnRA with seropositive rheumatoid arthritis (SpRA) to investigate potential mechanisms contributing to differences in antibody production. Methods: This study included 120 patients diagnosed with RA and 78 patients diagnosed with psoriatic arthritis (PsA), comprising 41 cases of SnRA and 79 cases of SpRA. Clinical, serological, and immune data were collected from all participants to systematically identify and confirm the most pivotal immunological distinctions between SnRA and SpRA. Results: (1) SpRA demonstrates more pronounced T-helper 17 cells (Th17)/Regulatory T cells (Treg) dysregulation, vital immunological differences from SnRA. (2) SpRA exhibits higher inflammatory cytokine levels than SnRA and PsA. (3) Lymphocyte subset ratios and cytokine overall distribution in SnRA close to PsA. (4) Interleukin-4 (IL-4) emerges as the central immunological disparity marker between SnRA and SpRA. Conclusion: Th17/Treg imbalance is one of the vital immunological disparities between SnRA and SpRA. Interestingly, PsA and SnRA display similar peripheral blood immunological profiles, providing immunological evidence for these two diseases' clinical and pathological similarities. Furthermore, IL-4 emerges as the central immunological disparity marker between SnRA and SpRA, suggesting its potential role as a triggering mechanism for differential antibody production.

Impaired immune tolerance mediated by reduced Tfr cells in rheumatoid arthritis linked to gut microbiota dysbiosis and altered metabolites.

BACKGROUND: Patients with rheumatoid arthritis (RA) showed impaired immune tolerance characterized by reduced follicular regulatory T (Tfr) cells, and they also exhibited altered gut microbiotas and their metabolites in RA. However, the association of gut microbiotas and their metabolites with the immune tolerance mediated by Tfr cells in RA remains unclear. METHODS: Peripheral blood and stool samples were collected from 32 new-onset RA patients and 17 healthy controls (HCs) in the Second Hospital of Shanxi Medical University between January 2022 and June 2022. The peripheral blood was used to detect the circulating regulatory T (Treg), helper T(Th)17, Tfr, and follicular helper T (Tfh) cells by modified flow cytometry. The stool samples were used to analyze the gut microbiotas and their metabolites via 16S rDNA sequencing and metabolomic profiling. We aimed to characterize the gut microbiotas and their metabolites in RA and identified their association with Tfr cell-mediated immune tolerance. RESULTS: The new-onset RA demonstrated reduced Treg and Tfr cells, associated with the disease activity and autoantibodies. There were significant differences in gut microbiotas between the two groups as the results of ß diversity analysis (P = 0.039) including 21 differential gut microbiotas from the phylum to genus levels. In which, Ruminococcus 2 was associated with the disease activity and autoantibodies of RA, and it was identified as the potential biomarker of RA [area under curve (AUC) = 0.782, 95% confidence interval (CI) = 0.636-0.929, P = 0.001]. Eleven differential metabolites were identified and participated in four main pathways related to RA. Arachidonic acid might be the potential biomarker of RA (AUC = 0.724, 95% CI = 0.595-0.909, P = 0.038), and it was the core metabolite as the positive association with six gut microbiotas enriched in RA. The reduced Tfr cells were associated with the altered gut microbiotas and their metabolites including the Ruminococcus 2, the arachidonic acid involved in the biosynthesis of unsaturated fatty acid pathway and the 3-methyldioxyindole involved in the tryptophan metabolism pathway. CONCLUSION: The breakdown of immune tolerance mediated by reduced Tfr cells was associated with the altered gut microbiotas and their metabolites implying the possible mechanism of RA pathogenesis from the perspective of microecology-metabolism-immune.

Elevated serum IL-2 and Th17/Treg imbalance are associated with gout.

Gout is considered an auto-inflammatory disorder, and the immunological drivers have not been fully unraveled. This study compared the peripheral lymphocyte and CD4+T cell subsets, and cytokines in gout and healthy controls (HCs) to explore the contributions of T helper 17 (Th17) cells, T regulatory (Treg) cells and cytokines to the pathogenesis of gout. We enrolled 126 gout patients (53 early-onset gout with age of first presentation < 40 years, and 73 late-onset gout with age of first presentation ≥ 40 years) and 77 HCs. Percentage and absolute numbers of peripheral lymphocyte and CD4+T cell subpopulations in each group were detected by flow cytometry. The serum cytokine levels were determined by flow cytometric bead array. For circulating CD4+T cell subsets, Th17/Treg ratio was significantly higher in early-onset gout, late-onset gout and gout without tophus than HCs; Th17 cells were significantly elevated in early-onset gout and gout without tophus, while the percentage of Treg cells was significantly decreased in early-onset and late-onset gout. Additionally, gout patients had significantly higher cytokines levels (including IL-2, IL-4, IL-6, IL-10, IL-17, IFN-γ, and TNF-α) than HCs; IL-2 levels were positively correlated with Treg cells and negatively correlated with ESR. ROC analysis showed that disease duration, CRP and fibrinogen, had moderate predictive performances for tophus in gout (the AUCs were 0.753, 0.703 and 0.701, respectively). Our study suggests that early-onset and late-onset gout differ in Th17/Treg imbalance, which in early-onset gout is due to elevated Th17 cells and in late-onset gout is due to decreased Treg cells. And increased serum cytokine levels, especially IL-2, may play an essential role in that. Restoring Th17/Treg balance may be a crucial way to improve the prognosis of gout patients.

Impact on sulfadiazine bio-accessibility in soils through organic diffusive gradients in thin films (o-DGT): Differentiation based on microplastic polymers, aging, and soil properties.

Due to the similar sources of swage irrigation, organic fertilizer, and sludge application, microplastics (MPs) and antibiotics coexist inevitably in the agriculture soils. However, the impacts of MPs with different polymer types and aging status on the bio-accessibility of co-existing antibiotics in soils remained unclear. Therefore, we using the diffusive gradients films for organic compounds devices (o-DGT) to evaluated the distribution of sulfadiazine (SDZ) in both paddy soil and saline soil amended with 0.5 % (w/w) MPs. Four polymer types (polyethylene: PE, polypropylene: PP, polyamide: PA, and polyethylene terephthalate: PET) and two aging statuses (aged PE and aged PP) of MPs were used in this study. Results showed that soil properties significantly influence the partition of SDZ in soil and soil solution, and SDZ gained a lower degradation rate but higher mobility in saline soil. MPs pose different impacts on partition of SDZ between paddy soil and saline soil. Notably, PP reduced the labile solid phase-solution phase partition coefficient (Kdl) by 17.7 % in paddy soil, while PE, PP, and aPE increased the Kdl value by 2.00, 1.62, and 2.81 times in saline soil. Besides, in saline soil, all the MPs reduced the SDZ concentration in the soil solution, while significantly increased the SDZ in o-DGT phase. Conversely, MPs did not impact the SDZ's o-DGT concentration in paddy soil. Additionally, MPs increased the R value of SDZ in two soils, especially in saline soil. It suggested that MPs could potentially enhance the resupply of SDZ from soil to plants, particularly under saline conditions. Furthermore, aged MPs had a more pronounced effect on these indicators compared to virgin MPs in saline soil. Therefore, MPs in soil poses a potential risk for biota's uptake of SDZ, particularly in fragile environment. Moreover, the risk intensifies with aged MPs.

Polyethylene microplastic modulates lettuce root exudates and induces oxidative damage under prolonged hydroponic exposure.

Root exudates are pivotal in plant stress responses, however, the impact of microplastics (MPs) on their release and characteristics remains poorly understood. This study delves into the effects of 0.05 % and 0.1 % (w/w) additions of polyethylene (PE) MPs on the growth and physiological properties of lettuce (Lactuca sativa L.) following 28 days of exposure. The release characteristics of root exudates were assessed using UV-vis and 3D-EEM. The results indicated that PE increased leaf number but did not significantly affect other agronomic traits or pigment contents. Notably, 0.05 % PE increased the total root length and surface area compared to the 0.1 % addition, while a non-significant trend towards decreased root activity was observed with PE MPs. PE MPs with 0.1 % addition notably reduced the DOC concentration in root exudates by 37.5 %, while 0.05 % PE had no impact on DOC and DON concentrations. PE addition increased the SUVA254, SUVA260, and SUVA280 values of root exudates, with the most pronounced effect seen in the 0.05 % PE treatment. This suggests an increase of aromaticity and hydrophobic components induced by PE addition. Fluorescence Regional Integration (FRI) analysis of 3D-EEM revealed that aromatic proteins (region I and II) were dominant in root exudates, with a slight increase in fulvic acid-like substances (region III) under 0.1 % PE addition. Moreover, prolonged PE exposure induced ROS damage in lettuce leaves, evidenced by a significant increase in content and production rate of O2·-. The decrease in CAT and POD activities may account for the lettuce's response to environmental stress, potentially surpassing its tolerance threshold or undergoing adaptive regulation. These findings underscore the potential risk of prolonged exposure to PE MPs on lettuce growth.

Microplastic formation and simultaneous release of phthalic acid esters from residual mulch film in soil through mechanical abrasion.

The application of plastic mulch film could effectively enhance the productivity of facility agriculture. However, releasing microplastic and phthalate from mulch films in soil has attracted increasing concerns, and releasing characters of microplastic and phthalate from mulch films during their mechanical abrasion remains unclear. This study elucidated the dynamics and impact factors of microplastic generation, including the thickness, polymer types and ageing of mulch film during mechanical abrasion. Releasing characters of the di(2-Ethylhexyl) phthalate (DEHP), a common type of phthalate in soil, from mulch film during mechanical abrasion were also explored. Results showed that 2 pieces of mulch film debris increased to 1291 pieces of microplastic after five days of mechanical abrasion, with exponential growth in the microplastic generation. After mechanical abrasion, the thinnest (0.008 mm) mulch film completely transformed into microplastics. However, the thicker mulch (>0.01 mm) suffered slight disintegration, making it feasible to be recycled. The biodegradable mulch film discharged the most microplastics (906 pieces) compared with the HDPE (359 pieces) and LDPE (703 pieces) mulch film after three days of mechanical abrasion. In addition, the mild thermal and oxidative ageing could result in 3047 and 4532 pieces of microplastic emissions from mulch film after three days of mechanical abrasion, which were ten times more than the original mulch film (359 pieces). Furthermore, negligible DEHP was released from mulch film without mechanical abrasion, while the released DEHP significantly correlated with generated microplastics during mechanical abrasion. These results demonstrated the crucial role of mulch film disintegration in phthalate emissions.

Stratified distribution of Th17 and Treg cells in patients with multi-stage rheumatoid arthritis.

OBJECTIVE: Rheumatoid arthritis (RA) is a typical, progressive autoimmune disease. Its occurrence and development are associated with dysregulation of T and B cell numbers. However, the specific immune characteristics of different RA courses remain incompletely defined. Here, we describe the peripheral blood lymphocyte subsets, particularly CD4 + T subsets, of different RA courses with a focus on early RA (Ea-RA). METHODS: In all, 131 patients with Ea-RA, 117 with advanced RA (Ad-RA), and 109 with treated RA (Tr-RA) were enrolled. We collected general clinical data. Whole blood samples obtained from the patients and 97 healthy controls (HCs) were analysed via flow cytometry. RESULTS: Decreased absolute NK cell numbers and increased CD4/CD8 T cell ratios were observed in different RA groups, including Ea-RA, compared to healthy controls. In Ea-RA patients, the Th17 and Treg cell numbers were similar to those in HCs. We performed k-means clustering based on the profiles of Th17 and Treg cells for patients with multi-stage of RA. We identified three patient types: type A characterised by relatively low Treg and Th17 cell numbers, type B with moderate levels of Treg cells and levels of Th17 cells similar to that of type C patients, and type C with high levels of Treg cells and levels of Th17 cells similar to that of type B patients. CONCLUSION: The immune characteristics of Ea-RA patients differ from those of HCs; an immune system disorder is apparent although no differences in Th17 and Treg levels were evident between Ea-RA patients and HCs. We found distributional heterogeneities of Th17 and Treg cells in patients with multi-stage of RA. Stratified management based on such heterogeneity may serve as a useful novel immunotherapy allowing of early intervention.

High resolution intravital photoacoustic microscopy reveals VEGF-induced bone regeneration in mouse tibia.

Osteogenesis and angiogenesis are essential for bone homeostasis and repair. Newly formed vessels convey osteogenic progenitors during bone regeneration. However, the lack of continuous and label-free visualization of the bone microvasculature has resulted in little understanding of the neovascular dynamics. Here, we take advantage of optical-resolution photoacoustic microscopy (ORPAM) for label-free, intravital, long-term observation of the bone vascular dynamics, including angiogenesis, remodeling and quantified angiogenic effect of locally-applied vascular endothelial growth factor (VEGF) in the murine tibial defect model. We employed ex vivo confocal microscopy and micro-computed tomography (micro-CT) imaging to verify the positive role of VEGF treatment. VEGF treatment increased the concentration of total hemoglobin, vascular branching, and vascular density, which correlated with more osteoprogenitors and increased bone formation within the defect. These data demonstrated ORPAM as a useful imaging tool that detected functional capillaries to understand hemodynamics, and revealed the effectiveness of locally delivered therapeutic agents with sufficient sensitivity, contributing to the understanding of spatiotemporal regulatory mechanisms on blood vessels during bone regeneration.

Do microplastics affect sulfamethoxazole sorption in soil? Experiments on polymers, ionic strength and fulvic acid.

Microplastics (MPs) and sulfamethoxazole (SMX) are emerging contaminants that are ubiquitous in the soil environment. In this study, we investigated MPs polymer type and soil environmental factor effects on SMX adsorption behavior in the soil system. Our results showed that MPs dosage affected the soil particles' SMX adsorption rate and capacity (Qe). Adding 1 % polystyrene (PS) increased the SMX adsorption rate significantly. The value of K1, which represented the adsorption rate, increased from 0.569 h-1 to 1.019 h-1. However, the addition of MPs reduced the soil's SMX equilibrium adsorption capacity slightly. Moreover, increasing salinity strength enhanced SMX adsorption capacity by MPs significantly. However, increasing calcium ions concentration decreased SMX adsorption in the MPs amended soil due to multivalent cationic bridging and competitive adsorption mechanisms. In addition, we observed that fulvic acid addition inhibited SMX adsorption. This study suggests that the addition of MPs reduced the adsorption of SMX in the soil slightly due to dilution effect. Meanwhile, changes in environmental factors also affected the adsorption behavior of SMX in soil amended with MPs.

Polyethylene and polyvinyl chloride microplastics promote soil nitrification and alter the composition of key nitrogen functional bacterial groups.

Microplastics (MPs) contamination in soils seriously threatens agroecosystems globally. However, very few studies have been done on the effects of MPs on the soil nitrogen cycle and related functional microorganisms. To assess MP's impact on the soil nitrogen cycle and related functional bacteria, we carried out a one-month soil incubation experiment using typical acidic soil. The soil was amended with alfalfa meal and was spiked with 1% and 5% (mass percentage) of low-density polyethylene (LDPE) and polyvinyl chloride (PVC) MPs. Our results showed that both LDPE and PVC addition significantly increased soil nitrification rate and nitrate reductase activity, which could further promote soil denitrification. The relative abundance of diazotrophs, ammonium oxidizing, and denitrifying bacterial groups were significantly altered with MPs addition. Moreover, the MPs treatments greatly enhanced denitrifying bacteria richness. Redundancy analysis showed that nitrate reductase activity was the most significant factor affecting the soil functional bacterial community. Correlation analysis shows that Nitrosospira genus might be for the improvement of soil nitrification rate. Our results implied that MPs exposure could significantly affect the soil nitrogen cycling in farmland ecosystems by influencing essential nitrogen functional microorganisms and related enzymatic activities.

Applying Neuromorphic Computing Simulation in Band Gap Prediction and Chemical Reaction Classification.

The rapidly developing artificial intelligence (AI) requires revolutionary computing architectures to break the energy efficiency bottleneck caused by the traditional von Neumann computing architecture. In addition, the emerging brain-machine interface also requires computational circuitry that can conduct large parallel computational tasks with low energy cost and good biocompatibility. Neuromorphic computing, a novel computational architecture emulating human brains, has drawn significant interest for the aforementioned applications due to its low energy cost, capability to parallelly process large-scale data, and biocompatibility. Most efforts in the domain of neuromorphic computing focus on addressing traditional AI problems, such as handwritten digit recognition and file classification. Here, we demonstrate for the first time that current neuromorphic computing techniques can be used to solve key machine learning questions in cheminformatics. We predict the band gaps of small-molecule organic semiconductors and classify chemical reaction types with a simulated neuromorphic circuitry. Our work can potentially guide the design and fabrication of elementary devices and circuitry for neuromorphic computing specialized for chemical purposes.

An artificial bone window for long-term photoacoustic monitoring of bone recovery.

Blood vessels that deliver nutrients and oxygen over the entire body is essential for bone homeostasis. Especially, for the bone recovery, long-term in vivo vascular imaging is desirable. Here, we propose an optical and ultrasonic transparent bone window, which allows repeated, chronic monitoring of bone angiogenesis in mouse tibia defect. A metal ring with an outer diameter of 2 mm and an inner diameter of 1 mm is bonded with a silicone-based polydimethylsiloxane (PDMS) film and cover the bone surface, which can effectively eliminate the inflammation caused by repeated wound opening before imaging. We make a bone defect model in mouse tibia, and employ an optical resolution photoacoustic microscopy (ORPAM) to provide a high-resolution, label-free, long-term, in vivo observation of the bone vascularization during the bone defect healing. The results suggest that the artificial bone window can remain stable for inspection and play positive role for bone repair.

Dynamic Model of the Short-Term Synaptic Behaviors of PEDOT-based Organic Electrochemical Transistors with Modified Shockley Equations.

Neuromorphic computing is an emerging area with prospects to break the energy efficiency bottleneck of artificial intelligence (AI). A crucial challenge for neuromorphic computing is understanding the working principles of artificial synaptic devices. As an emerging class of synaptic devices, organic electrochemical transistors (OECTs) have attracted significant interest due to ultralow voltage operation, analog conductance tuning, mechanical flexibility, and biocompatibility. However, little work has been focused on the first-principal modeling of the synaptic behaviors of OECTs. The simulation of OECT synaptic behaviors is of great importance to understanding the OECT working principles as neuromorphic devices and optimizing ultralow power consumption neuromorphic computing devices. Here, we develop a two-dimensional transient drift-diffusion model based on modified Shockley equations for poly(3,4-ethylenedioxythiophene) (PEDOT)-based OECTs. We reproduced the typical transistor characteristics of these OECTs including the unique non-monotonic transconductance-gate bias curve and frequency dependency of transconductance. Furthermore, typical synaptic phenomena, such as excitatory/inhibitory postsynaptic current (EPSC/IPSC), paired-pulse facilitation/depression (PPF/PPD), and short-term plasticity (STP), are also demonstrated. This work is crucial in guiding the experimental exploration of neuromorphic computing devices and has the potential to serve as a platform for future OECT device simulation based on a wide range of semiconducting materials.