Several novel brevetoxin derivatives were isolated and identified in Karenia brevis cultures and natural blooms by using solid phase extraction (SPE) and LC/MS(MS) techniques. These analogs were more polar compared with previously described brevetoxins, and were poorly extractable by conventional non-polar solvent (chloroform) partitioning. Brevetoxin analogs were structurally confirmed as hydrolyzed (open A-ring) forms of brevetoxins PbTx-1, PbTx-7, PbTx-2, and PbTx-3, and of oxidized PbTx-1 and PbTx-2. Some of these open A-ring derivatives were in greater abundance than their non-hydrolyzed counterparts. All were in much greater abundance in bloom water filtrate compared with cell-rich fractions. Open A-ring compounds were cytotoxic in mouse neuroblastoma (N2a) cell assay. In the K. brevis bloom-exposed Eastern oyster, brevetoxin metabolites with opened A rings were identified (e.g., open-ring cysteine-PbTx conjugates), contributing to their overall toxin burden.
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http://dx.doi.org/10.1016/j.toxicon.2006.04.015 | DOI Listing |
Adv Sci (Weinh)
January 2025
School of Materials Science and Engineering, Zhengzhou University, No.100 Science Avenue, Zhengzhou, 450001, P. R. China.
Photoswitchable fluorescent materials have gained significant attention for their potential in advanced information encryption and anti-counterfeiting applications. However, the common use of UV light to trigger the isomerization processes leads to photobleaching and poor fatigue resistance. Visible-light-driven fluorescent photoswitches are highly desirable, but achieving high cyclization yield remains challenging.
View Article and Find Full Text PDFMethods Mol Biol
January 2025
Department of Bioengineering, Izmir Institute of Technology, Izmir, Turkey.
Negative magnetophoresis is employed to levitate cells in a paramagnetic medium without the need for magnetic labeling, preserving their natural state and minimizing toxicity. The single-ring magnet configuration that provides an open space in the levitation chamber enhances culture accessibility and scalability, enabling the formation of millimeter-sized 3D structures through cellular self-assembly. This system provides a versatile and cost-effective approach for diverse applications, including tissue engineering and biofabrication.
View Article and Find Full Text PDFMicromachines (Basel)
November 2024
School of Instrument and Electronics, North University of China, Taiyuan 030051, China.
This paper proposes a method to control the sensitivity of a ring MEMS gyroscope by adjusting the driving control voltage via MEMS. The aim is to explore the relationship between the range of the ring MEMS gyroscope and the driving control voltage, establishing a mathematical model that correlates driving control voltage with sensitivity. By applying different driving voltages to the same gyroscope, the study evaluates the performance and range of the gyroscope.
View Article and Find Full Text PDFSci Rep
September 2024
State Key Laboratory of Bridge and Tunnel Engineering in Mountainous Areas, Chongqing Jiaotong University, Chongqing, 400074, China.
To enhance construction efficiency, improve lining quality, and reduce project costs, this study proposes a prefabricated arch structure scheme for large-span open-cut highway tunnels, specifically targeting the ongoing construction of an eight-lane open-cut tunnel on Chongqing's Xinsen Avenue. By establishing a finite element "load-structure" integrated calculation model and adopting an iterative analysis method, the impact of joint stiffness variations on internal force distribution was determined. Combined with long-term field monitoring and measurements, a thorough analysis was conducted on the performance of the prefabricated arch structure during different construction stages.
View Article and Find Full Text PDFA novel seminaphthorhodafluor-based fluorescent probe was designed and prepared. It exhibited an outstanding off-on fluorescence response (about 45-fold enhancement) to Cu because the structure changed from a spirocyclic form to a ring-open state. It showed satisfactory detection performances for Cu with fast response speed, high selectivity and anti-interference, and a low detection limit (22.
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