Blueberries (Vaccinium corymbosum L.), valued for their nutritional benefits and economic significance, have become Peru’s leading agro-export crop. However, intensive cultivation can lead to phytosanitary problems if not addressed promptly, posing a serious threat to blueberry production. This study aimed to isolate and identify the causal agent of leaf spot symptoms initially observed in blueberries cultivated in Peru, marking the first formal documentation of its presence in the country. In 2022, leaf spot symptoms were recorded on V. corymbosum cv. Biloxi, in the north of Lima, Peru. Field observations revealed necrotic, sunken spots on leaves and fruits, with 4.84% of leaves diseased and 1.28% of fruits affected. Pathogen isolation and microscopic studies identified Alternaria alternata as the primary causal agent, which was confirmed by genome sequencing using Oxford Nanopore Technology. Pathogenicity tests demonstrated the fungus’ ability to reproduce symptoms identical to those observed in the field, fulfilling Koch’s postulates. Under experimental conditions, disease severity increased over time, with the affected leaf area ranging from 9.35% to 25.61% between 7 and 14 days post-inoculation. This study establishes A. alternata as a pathogen of blueberries in Peru and provides essential insights for future research and strategies to mitigate its impact on the industry.
Reported studies regarding binder jetting additive manufacturing have investigated the effects of process parameters (e.g., drying time and ultrasonic vibration intensity) on a range of response variables. However, the effects of these process parameters on the energy consumption of binder jetting printers remain largely unexplored. This study investigates the energy consumption of a binder jetting printer experimentally, focusing on three parameters: drying time, ultrasonic vibration intensity, and target powder bed temperature. Experiments were conducted under controlled conditions designed to isolate subsystem contributions to power consumption, including drying tests without powder and ultrasonic vibration tests without powder dispensing or hopper traversal. Energy consumption was calculated based on the real-time measurements of the electric current drawn by the binder jetting printer during experiments at different drying times (1, 15, 30, 45, and 60 s), ultrasonic vibration intensities (25%, 50%, 75%, and 100%), and target powder bed temperatures (40, 60, and 80 °C). Results showed that longer drying times and higher target powder bed temperatures significantly increased energy consumption, while ultrasonic vibration intensity had a negligible effect on energy consumption. These results provide a basis for understanding energy consumption at the subsystem level, supporting future studies on subsystem-level energy optimization.
Paclitaxel (Taxol) is a clinically important diterpenoid anticancer drug whose industrial production remains constrained by limited Taxus resources and semi-synthetic routes. Driven by the rapid advancement of genome mining and synthetic biology technologies, the past two years have witnessed substantial breakthroughs in elucidating the biosynthetic pathway of paclitaxel. The pathway constitutes an exceptionally complex biosynthetic network comprising approximately 20 enzymatic steps, predominantly catalyzed by cytochrome P450 monooxygenases, 2-oxoglutarate-dependent dioxygenases (ODDs), and acyltransferases. Nevertheless, microbial production of paclitaxel remains highly obstructed, largely due to inefficient catalytic abilities, enzyme promiscuities, and complex metabolic fluxes. This review summarizes recent progress in elucidating the evolutionary origins and catalytic mechanistic basis of the paclitaxel biosynthetic pathway, with particular emphasis on the emerging technologies and catalytic mechanism studies. Furthermore, current challenges and perspectives for constructing efficient artificial biosynthetic pathways are discussed, providing insights into the future biotechnological production of paclitaxel.
Room temperature phosphorescence (RTP) and organic thermally activated delayed fluorescence (TADF) materials have merited enormous application prospects in organic optoelectronics. In spite of this, TADF and RTP dual emissions based on single-chromophore polymers still face a great challenge. In this work, we develop a monomer (CzBT) with twisted electron donating carbazole and electron withdrawing benzothiadiazole (D-A) structure and then copolymerize it with N-isopropylacrylamide (NIPAM) in different ratios to adjust TADF and RTP emission. The polymers exhibit TADF emission from aggregated chromophores, RTP emission with a lifetime of 240 ms from dispersed chromophores, and a high absolute photoluminescence quantum efficiency (20%). Theoretical calculations confirm that the introduction of twisted D-A structure and heteroatoms can not only promote spin orbital coupling to facilitate the accumulation of triplet excitons for RTP emission, but also help RISC to emit TADF in the aggregated state. When applied to solution-processable organic light emitting diodes (OLEDs) devices, excellent current efficiency of 62.7 cd/A and maximum external quantum efficiency of 19.9% were achieved attributing to the dominant TADF emission. This class of polymers paves the way for high-efficiency optoelectronic devices.
Photocatalytic degradation of antibiotic molecules has great significance in environmental pollution control. Bi4Ti3O12 with a layered structure is one of the emerging visible−light−responsive photocatalysts. However, the environmental effects of antibiotic degradation have not received sufficient attention. This study employed plate−like Bi4Ti3O12 derived from Na2Ti3O7 nanowires for ciprofloxacin (CIP) degradation, and investigated the biotoxicity of degradation products on aquatic organisms and plant seedlings. It was found that an appropriate hydrothermal treatment time with ethylene glycol could slightly enhance the photocatalytic performance of Bi4Ti3O12, and this might be attributed to the increased density of active sites resulting from the regulation of microstructure. Concurrently, the degradation products of CIP were detected and predicted for biotoxicity; the effects of the CIP degradation residual solution on the growth of peas, wheat, and zebrafish larvae were also investigated. Under the present experimental conditions, the Bi4Ti3O12−24h photocatalyst−involved CIP degradation process could reduce the biotoxicity of the CIP solution (40 mg/L) and exhibit low toxicity to several individual organisms, including some actual plants and animals.
