Search Results (6)

The interplay between water-saving irrigation and potassium (K) management in regulating paddy methane (CH₄) emissions remains poorly understood. It remains unclear whether carbon pool enhancement induced by K fertilization could counteract the oxidation effects under non-flooded irrigation. Here, we conducted a field-based trial over two years to explore how irrigation regimes (continuous flooding, I_F; intermittent irrigation, I_I) and K application rates (K₀, K₇₅, K₁₅₀ kg ha⁻¹) modify soil redox status, carbon pools, crop growth, CH₄ emissions and economic benefits. Intermittent irrigation markedly elevated soil redox potential (Eh), suppressed dissolved organic carbon (DOC), and substantially reduced two-year average CH₄ emissions by 75.1–76.9%, regardless of K supply. Under I_F, high-rate K fertilization (K₁₅₀) stimulated cumulative CH₄ emissions; nevertheless, such K-driven CH₄ stimulation was completely offset under intermittent irrigation. Soil Eh, DOC and microbial biomass carbon (MBC) dominated CH₄ variation, among which Eh exerted the primary control. Intermittent irrigation combined with K fertilization improved rice grain yield. A comprehensive TOPSIS-Entropy multi-criteria evaluation identified the I_IK₇₅ treatment as the optimal option balancing environmental benefits and economic returns. Collectively, intermittent irrigation can mitigate the methanogenic risk from high potassium input, providing a promising redox-regulated strategy for low-CH₄ emission and high rice production. Full article

Background: The global rise in multidrug-resistant (MDR) Gram-negative bacteria (GNB) poses an urgent challenge for infection control and antibiotic stewardship. Among these, Klebsiella pneumoniae is a major cause of hospital-acquired infections and is listed as a critical priority pathogen by the World Health Organization. Peru reports an exceptionally high prevalence of MDR K. pneumoniae, underscoring the need for innovative antimicrobial approaches. Methods: Here, we describe the isolation and characterization of lytic Klebsiella bacteriophage from sewage samples collected from the Huatanay River (Cusco, Peru) in 2023. Phages were isolated using the reference strain MDR K. pneumoniae ATCC BAA-2814. Then, they were screened against 50 clinical MDR K. pneumoniae strains. Results: The phage H33IIK demonstrated effective antibacterial capability, showing strict host specificity for K. pneumoniae, thermal stability, moderate pH tolerance, and high burst size. Whole-genome sequencing analysis classified it within the class Caudoviricetes, family Ackermannviridae, and genus Taipeivirus. The genomic analysis confirmed the absence of lysogeny-related, antimicrobial resistance, and virulence genes, supporting its suitability and safety for potential biotechnological applications. Conclusions: These findings highlight phage H33IIK as a lytic agent effective against MDR K. pneumoniae. It could contribute to the development of phage-based approaches to combat MDR GNB. Full article

Background: Morphine analgesic tolerance (MAT) limits the clinical application of morphine in the management of chronic pain. IIK7 is a melatonin type 2 (MT2) receptor agonist known to have antioxidant properties. Oxidative stress is recognized as a critical factor in MAT. This study sought to assess the impact of IIK7 on the progression of MAT and its potential to reverse pre-existing MAT. Methods: Wistar rats underwent partial sciatic nerve transection (PSNT) surgery to induce neuropathic pain (NP). Seven days post nerve transection, we implanted an intrathecal (i.t.) catheter and linked it to an osmotic pump. Rats were randomly divided into the following groups: sham-operated/vehicle, PSNT/vehicle, PSNT/IIK7 50 ng/h, PSNT/MOR 15 g/h, and PSNT/MOR 15 g + IIK7 50 ng/h. We implanted two i.t. catheters for drug administration and the evaluation of the efficacy of IIK7 in reversing pre-established MAT. We linked one to an osmotic pump for MOR or saline continuous i.t. infusion. On the 7th day, the osmotic pump was disconnected, and 50 μg of IIK7 or the vehicle was administered through the second catheter. After 3 h, 15 μg of MOR or saline was administered, and the animal behavior tests were performed. We measured the levels of mRNA for Nrf2 and HO-1, pro-inflammatory cytokines (PICs), and the microglial and astrocyte activation in the spinal cord. Results: The co-administration of IIK7 with MOR delayed MAT development in PSNT rats by restoring Nrf2 and HO-1 while also inhibiting the microglial-cell and astrocyte activation, alongside the suppression of PICs. Additionally, a single injection of high-dose 50 μg IIK7 was efficient in restoring MOR’s antinociception in MOR-tolerant rats. Conclusions: Our results indicate that the co-infusion of ultra-low-dose IIK7 can delay MAT development and a high dose can reverse pre-existing MAT. Full article

This study aims to investigate the effect of the selective MT2 receptor agonist, IIK7, on corneal autophagy and apoptosis, aiming to reduce corneal epithelial damage and inflammation from blue light exposure in mice. Eight-week-old C57BL/6 mice were divided into BL-exposed (BL) and BL-exposed with IIK7 treatment (BL + IIK7 group). Mice underwent blue light exposure (410 nm, 100 J) twice daily with assessments at baseline and on days 3, 7, and 14. Corneal samples were analyzed for MT2 receptor expression, autophagy markers (LC3-II and p62), and apoptosis indicators (BAX expression and TUNEL assay). Then, mice were assigned to normal control, BL, and BL + IIK7. Ocular surface parameters, including corneal fluorescein staining scores, tear volume, and tear film break-up time, were evaluated on days 7 and 14. On day 14, reactive oxygen species (ROS) levels and CD4⁺ IFN-γ⁺ T cells percentages were measured. The BL group exhibited higher LC3-II and p62 expression, while the BL + IIK7 group showed reduced expression (p < 0.05). The TUNEL assay showed reduced apoptosis in the BL + IIK7 group compared to the BL group. ROS levels were lower in the BL + IIK7 group. The BL + IIK7 group showed improved ocular surface parameters, including decreased corneal fluorescein staining and increased tear volume. The percentages of CD4⁺ IFN-γ⁺ T cells indicated reduced inflammatory responses in the BL + IIK7 group. The MT2 receptor agonist IIK7 regulates corneal autophagy and apoptosis, reducing corneal epithelial damage and inflammation from blue light exposure. Full article

As the volume of satellite images increases rapidly, unsupervised classification can be utilized to swiftly investigate land cover distributions without prior knowledge and to generate training data for supervised (or deep learning-based) classification. In this study, an inter-image k-means clustering algorithm (IIkMC), as an improvement of the native k-means clustering algorithm (kMC), was introduced to obtain a single set of class signatures so that the classification results could be compatible among multiple images. Because IIkMC was a computationally intensive algorithm, parallelized approaches were deployed, using multi-cores of a central processing unit (CPU) and a graphics processing unit (GPU), to speed up the process. kMC and IIkMC were applied to a series of images acquired in a PlanetScope mission. In addition to the capability of the inter-image compatibility of the classification results, IIkMC could settle the problem of incomplete segmentation and class canceling revealed in kMC. Based on CPU parallelism, the speed of IIkMC improved, becoming up to 12.83 times better than sequential processing. When using a GPU, the speed improved up to 25.53 times, rising to 39.00 times with parallel reduction. From the results, it was confirmed IIkMC provided more reliable results than kMC, and its parallelism could facilitate the overall inspection of multiple images. Full article

Melatonin analogs topically administered evoke a potent tear secretagogue effect in rabbits. This route of drug administration requires high drug concentration and frequent dosing due to its reduced ocular surface retention. Therefore, contact lenses (CLs) have emerged as an alternative drug-delivery system that prolongs drug retention in the cornea, improving its therapeutic performance. This study explores the in vitro ability of five commercially available hydrogel CLs to act as a delivery system for melatonin analogs and the in vivo secretagogue effect of melatonin analog-loaded CLs. We soaked CLs with melatonin or melatonin analog solutions (1 mM) for 12 h. Spectroscopic assays showed that IIK7-loaded CLs led to the inadequate delivery of this compound. Conventional hydrogel lenses loaded with agomelatine released more agomelatine than silicone ones (16–33% more). In contrast, the CLs of silicone materials are more effective as a delivery system of 5-MCA-NAT than CLs of conventional materials (24–29%). The adaptation of CLs loaded with agomelatine or 5-MCA-NAT in rabbits triggered a higher tear secretion than the corresponding eye drops (78% and 59% more, respectively). These data suggest that CLs preloaded with melatonin analogs could be an adequate strategy to combat aqueous tear deficient dry eye disease. Full article