Kalmanol (1) is the first isolated kalmane-type grayanoid featuring a highly oxidized 5/8/5/5 tetracyclic carbon skeleton and 9 contiguous stereocenters. We have accomplished the efficient and asymmetric total synthesis of 1 in 16 steps from known compounds (20 steps from commercially available starting materials) by a modular synthetic strategy. A tetracyclic intermediate was prepared in a convergent manner through a Grignard reaction and a subsequent ring-closing metathesis reaction of two enantiomerically enriched fragments.
View Article and Find Full Text PDFMesoporous platinum (mPt) nanozyme possessed enzyme-like property of catalase (CAT) and peroxidase (POD), but the insufficient hydrogen peroxide (HO) concentration severely restricted its application in photodynamic therapy (PDT) and catalytic therapy. Herein, by depositing ultrasmall gold nanoparticles (AuNPs) and modifying photosensitizer IR808, a multifunctional nanozyme (mPt@Au-IR808) was designed to promote PDT/catalytic therapy through cascade enzyme-like reactions of glucose oxidase (GOx) and CAT/POD. In tumor microenvironment, the CAT-like oxygen (O) generation improved the PDT efficacy, and the POD-like hydroxyl radical (·OH) generation achieved endogenous catalytic therapy.
View Article and Find Full Text PDFObjective: This study aims to examine the thyroid hormone profile and its association with severe coronavirus disease 2019 (COVID-19) in patients infected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
Methods: This retrospective cohort study enrolled patients admitted to a tertiary hospital due to SARS-CoV-2 infection between February 18 and May 18, 2022. Clinical data were collected retrospectively from the electronic medical record system.
Soft X-ray imaging is a powerful tool to explore the structure of cells, probe material with nanometer resolution, and investigate the energetic phenomena in the universe. Conventional soft X-ray image sensors are by and large Si-based charge coupled devices that suffer from low frame rates, complex fabrication processes, mechanical inflexibility, and required cooling below -60 °C. Here, a soft X-ray photodiode is reported based on low-cost metal halide perovskite with comparable performance to commercial Si-based device.
View Article and Find Full Text PDFAtrial fibrillation (AF) is the most common cardiac arrhythmia in clinical practice. Halofuginone (HF) exerts beneficial effects on organ fibrosis, periodontitis, and cancer. However, the effect of HF against AF remains unknown.
View Article and Find Full Text PDFDiabetic cardiomyopathy (DCM) is identified as a progressive disease that may lead to irreparable heart failure. Toll-like receptor (TLR) signaling is believed to be implicated in the pathogenesis of DCM. This study intended to explore the potential impact of Toll-like receptor 4 (TLR4) on DCM and .
View Article and Find Full Text PDFHere we report a visible-light facilitated radical addition strategy for the preparation of various natural or unnatural α-amino acids from readily available glycine derivatives and alkenes. A key aspect in achieving this side carbon chain introduction reaction, while circumventing the well-documented cyclization pathway, was the employment of a radical-polar crossover strategy under redox neutral conditions.
View Article and Find Full Text PDFAntiferromagnets (AFMs) are ideal materials to boost neuromorphic computing toward the ultrahigh speed and ultracompact integration regime. However, developing a suitable AFM neuromorphic memory remains an aspirational but challenging goal. In this work, we construct such a memory based on the CoO/Pt heterostructure, in which the collinear insulating AFM CoO shows a strong perpendicular anisotropy facilitating its electrical readout and writing.
View Article and Find Full Text PDFProstate cancer rarely responds to immune-checkpoint blockade (ICB) therapies. Cancer-associated fibroblasts (CAF) are critical components of the immunologically "cold" tumor microenvironment and are considered a promising target to enhance the immunotherapy response. In this study, we aimed to reveal the mechanisms regulating CAF plasticity to identify potential strategies to switch CAFs from protumorigenic to antitumor phenotypes and to enhance ICB efficacy in prostate cancer.
View Article and Find Full Text PDFIEEE J Biomed Health Inform
November 2024
Automated retinal vessel segmentation is crucial for computer-aided clinical diagnosis and retinopathy screening. However, deep learning faces challenges in extracting complex intertwined structures and subtle small vessels from densely vascularized regions. To address these issues, we propose a novel segmentation model, called Geometry-Knowledge Embedded TransUNet (GKE-TUNet), which incorporates explicit embedding of topological features of retinal vessel anatomy.
View Article and Find Full Text PDFThe piezo-phototronic effect uses the piezoelectric potential/piezoelectric charge generated by the piezoelectric semiconductor material to regulate the energy band structure and photogenerated carrier behavior at the interface/junction, thereby modulating the device's performance. The positive/negative piezoelectric charges generated at the interface of piezoelectric semiconductors can reduce the electron/hole barriers and thus enhance the transport of photogenerated carriers. However, electron/hole potential wells are formed when the electron/hole potential barrier caused by positive/negative piezoelectric charges is lowered too much, hindering the transport of photogenerated carriers.
View Article and Find Full Text PDFDaphnetin has been demonstrated to exert beneficial effects on diabetes mellitus and renal complications. However, the role and molecular mechanism of daphnetin in diabetic cardiomyopathy (DCM) remain unclear. In this study, rats were injected with streptozotocin (STZ) to induce diabetes.
View Article and Find Full Text PDFMuB is a non-specific DNA-binding protein and AAA+ ATPase that significantly influences the DNA transposition process of bacteriophage Mu, especially in target DNA selection for transposition. While studies have established the ATP-dependent formation of MuB filament as pivotal to this process, the high-resolution structure of a full-length MuB protomer and the underlying molecular mechanisms governing its oligomerization remain elusive. Here, we use cryo-EM to obtain a 3.
View Article and Find Full Text PDFNimbolide has been demonstrated to possess protective properties against gestational diabetes mellitus and diabetic retinopathy. However, the role and molecular mechanism of nimbolide in diabetic cardiomyopathy (DCM) remain unknown. Diabetes was induced in rats via a single injection of streptozotocin (STZ) and then the diabetic rats were administered nimbolide (5 mg/kg and 20 mg/kg) or dimethyl sulfoxide daily for 12 weeks.
View Article and Find Full Text PDFConventional androgen deprivation therapy (ADT) targets the androgen receptor (AR) inhibiting prostate cancer (PCa) progression; however, it can eventually lead to recurrence as castration-resistant PCa (CRPC), which has high mortality rates and lacks effective treatment modalities. The study confirms the presence of high glutathione peroxidase 4 (GPX4) expression, a key regulator of ferroptosis (i.e.
View Article and Find Full Text PDFSurfactants are widely used as foaming agents to remove liquid accumulation in gas wells, enhancing natural gas production. The surfactant used in traditional foam sticks was dissolved and released as foam in a short period, especially at elevated downhole temperatures. This often requires the addition of foam sticks to maintain foam.
View Article and Find Full Text PDFHeterogeneous electrode materials possess abundant heterointerfaces with a localized "space charge effect", which enhances capacity output and accelerates mass/charge transfer dynamics in energy storage devices (ESDs). These promising features open new possibilities for demanding applications such as electric vehicles, grid energy storage, and portable electronics. However, the fundamental principles and working mechanisms that govern heterointerfaces are not yet fully understood, impeding the rational design of electrode materials.
View Article and Find Full Text PDFRecognition and judgment of X-ray computed tomography (CT) images play a crucial role in medical diagnosis and disease prevention. However, the storage and calculation of the X-ray imaging system applied in the traditional CT diagnosis is separate, and the pathological judgment is based on doctors' experience, which will affect the timeliness and accuracy of decision-making. In this paper, a simple-structured reservoir computing network (RC) is proposed based on GaO X-ray optical synaptic devices to recognize medical skeletal CT images with high accuracy.
View Article and Find Full Text PDFCapacitive deionization (CDI) is an emerging desalination technology for seawater desalination. The development of high-desalination and long-life electrode materials is a research focus in the global water treatment field. In this experiment, Tween T80 was used as a surface activator, and a modified electrode was prepared by facilitating the deposition of TiO active sites onto the surface of activated carbon through a sol-gel/hydrothermal two-step synthesis strategy.
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