The thermolysis of trans-3,4-dimethyl-1,2-dioxetane is studied by trajectory surface hopping. The significant difference between long and short dissociation times is rationalized by frustrated ...dissociations and the time spent in triplet states. If the C–C bond breaks through an excited state channel, then the trajectory passes over a ridge of the potential energy surface of that state. The calculated triplet quantum yields match the experimental results. The dissociation half-times and quantum yields follow the same ascending order as per the product states, justifying the conjecture that the longer dissociation time leads to a higher quantum yield, proposed in the context of the methylation effect. The populations of the molecular Coulomb Hamiltonian and diagonal states reach equilibrium, but the triplet populations with different S z components fluctuate indefinitely. Certain initial velocities, leading the trajectories to given product states, can be identified as the most characteristic features for sorting trajectories according to their product states.
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•Al was modified by soaking Al powder in water and then heat-treating in vacuum.•Modified Al has a high rate in reduction of Cr(VI) to Cr(III) ions in solution.•Modified Al exhibited ...an excellent recyclability in removing Cr(VI).•XPS indicated that Al surface passive oxide films become thin after modification.
Zero-valent aluminum has attracted considerable attention in degradation of organic contaminants and reduction of heavy metal ions due to its very low redox potential (E0(Al3+/Al0) = −1.662 V). Usually there is a passive oxide film on Al surface, inhibiting its electron transfer and leading to low reaction efficiency. In this work, metal Al surface was modified by loose fine Al2O3 (SM-Al) using a procedure of soaking Al powder in water for a time period and then heat-treating in vacuum. It was found that surface modification remarkably enhanced the reaction efficiency of zero-valent Al in reduction of Cr(VI) to Cr(III) ions in aqueous solution. The longer the soaking time of Al powder in water is, the higher the efficiency in removing Cr(VI) is. The effects of Al particle size and dosage, initial Cr(VI) concentration and reaction temperature on Cr(VI) removal were investigated as well. XPS analyses revealed that the decrease in thickness of Al surface passive oxide films and the promotion of surface covered loose Al2O3 phases on hydration of passive oxide films are two main reasons responsible for the rapid removal of Cr(VI) by SM-Al. Meanwhile, SM-Al exhibited an excellent recyclability and the reused SM-Al has a very fast reaction rate relative to as-prepared SM-Al, 80% of Cr(VI) can be removed even it was reused up to five cycles. The present study provides a new route to activate Al in removal of contaminants in aqueous solution.
We herein developed an efficient method for removing thioacetyl to synthesize acylated deoxy glycosides in a one-pot reaction, where the thioacetyl was selectively deacetylated by hydrazine hydrate ...in DMF within 2–5 min at room temperature, followed by desulfurization under UV light for 1–2 h in the presence of TCEP·HCl. The method was then used to synthesize 2-deoxy glycosides with absolute α/β-configuration via stereoselective control of C-2 thioacetate in glycosylation.
Fe-based metal-organic framework MIL-88A microrods were synthesized by hydrothermal method, which were used to adsorb As(V) in water for the first time. The experimental results indicated that ...MIL-88A has a very fast adsorption rate towards arsenic in water. The kinetic and isothermal data for arsenic removal were better fitted to the pseudo-second-order kinetic model and Langmuir model, respectively, implying a chemical and monolayer adsorption for As(V) on MIL-88A microrods. Two rate-controlling processes during adsorption were revealed by the intraparticle diffusion model. The maximum adsorption capacity of MIL-88A reached 145 mg g
−1
, higher than those of Fe-based MIL adsorbents reported previously, which probably originates from its unique microstructure with abundant OH
−
groups and an unusual large swelling towards water. These show that Fe-based MIL-88A is a good candidate for arsenic removal.
Cyclin-dependent kinases 2/4/6 (CDK2/4/6) play critical roles in cell cycle progression, and their deregulations are hallmarks of hepatocellular carcinoma (HCC).
We used the combination of ...computational and experimental approaches to discover a CDK2/4/6 triple-inhibitor from FDA approved small-molecule drugs for the treatment of HCC.
We identified vanoxerine dihydrochloride as a new CDK2/4/6 inhibitor, and a strong cytotoxicdrugin human HCC QGY7703 and Huh7 cells (IC50: 3.79 μM for QGY7703and 4.04 μM for Huh7 cells). In QGY7703 and Huh7 cells, vanoxerine dihydrochloride treatment caused G1-arrest, induced apoptosis, and reduced the expressions of CDK2/4/6, cyclin D/E, retinoblastoma protein (Rb), as well as the phosphorylation of CDK2/4/6 and Rb. Drug combination study indicated that vanoxerine dihydrochloride and 5-Fu produced synergistic cytotoxicity in vitro in Huh7 cells. Finally, in vivo study in BALB/C nude mice subcutaneously xenografted with Huh7 cells, vanoxerine dihydrochloride (40 mg/kg, i.p.) injection for 21 days produced significant anti-tumor activity (p < 0.05), which was comparable to that achieved by 5-Fu (10 mg/kg, i.p.), with the combination treatment resulted in synergistic effect. Immunohistochemistry staining of the tumor tissues also revealed significantly reduced expressions of Rb and CDK2/4/6in vanoxerinedihydrochloride treatment group.
The present study isthe first report identifying a new CDK2/4/6 triple inhibitor vanoxerine dihydrochloride, and demonstrated that this drug represents a novel therapeutic strategy for HCC treatment.
Hexavalent chromium Cr(VI) is one of the most common environmental contaminants due to its tremendous industrial applications, but its effects and mechanism remain to be investigated. Our previous ...studies showed that Cr(VI) exposure caused malignant transformation and tumorigenesis. This study showed that glycolytic proteins HK2 and LDHA levels were statistically significant changed in blood samples of Cr(VI)-exposed workers and in Cr-T cells compared to the control subjects and parental cells. HK2 and LDHA knockdown inhibited cell proliferation and angiogenesis, and higher HK2 and LDHA expression levels are associated with advanced stages and poor prognosis of lung cancer. We found that miR-218 levels were significantly decreased and miR-218 directly targeted HK2 and LDHA for inhibiting their expression. Overexpression of miR-218 inhibited glucose consumption and lactate production in Cr-T cells. Further study found that miR-218 inhibited tumor growth and angiogenesis by decreasing HK2 and LDHA expression in vivo. MiR-218 levels were negatively correlated with HK2 and LDHA expression levels and cancer development in human lung and other cancers. These results demonstrated that miR-218/HK2/LDHA pathway is vital for regulating Cr(VI)-induced carcinogenesis and human cancer development.
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•Long-term exposure of Cr(VI) increased expression levels of glycolysis regulatory enzymes HK2 and LDHA in human blood samples and Cr(VI)-transformed cells.•Silencing HK2 and LDHA inhibited cell proliferation and tube formation.•HK2 and LDHA were direct targets of miR-218. Overexpression of HK2 and LDHA reversed the inhibitory effects of miR-218.•Chronic Cr(VI) exposure induced angiogenesis and carcinogenesis by regulating miR-218/HK2/LDHA signaling.
Objective
Closed reduction combined with external fixation is a frequently utilized approach for treating distal radial fractures in adults. Nonetheless, the potential for re‐displacement following ...external fixation remains. Analyzing the factors influencing re‐displacement after nonsurgical treatment of distal radial fractures in adults is vital for preventing re‐displacement and making prognostic assessments.
Methods
A retrospective analysis was performed on 884 patients who underwent nonsurgical treatment for distal radius fractures in the reduction room of the Orthopedics and Traumatology Department of Integrated Traditional Chinese and Western Medicine at Tianjin Hospital, Tianjin, China, between July 2019 and December 2022. Patients were categorized into two groups, namely displaced and nondisplaced, based on radiographic outcomes. Factors affecting fracture re‐displacement were examined, including sex, age, side, AO/OTA type, external fixation, and radiographic outcomes at pre‐reduction and immediate reduction. Logistic regression analysis was employed to identify the risk factors for fracture re‐displacement, and ROC curves were constructed.
Results
Among the 884 patients, 563 (63.69%) experienced re‐displacement after fracture reduction. There were no statistically significant differences (p > 0.05) between the two groups in terms of gender, external fixation method, and palmar tilt angle at pre‐reduction and immediate reduction, while significant differences (p < 0.05) were observed in age, side, AO/OTA type, and radial inclination, radial length, and radiographic outcomes of ulnar variance at pre‐reduction and immediate reduction. Multifactorial logistic regression analysis revealed that age (odds ratio OR = 1.027, p < 0.001), AO/OTA type (OR = 2.327, p = 0.005), ulnar variance at pre‐reduction (OR = 1.142, p = 0.048), and ulnar variance at immediate reduction (OR = 1.685, p < 0.001) were significant factors (p < 0.05) associated with re‐displacement following nonoperative treatment of adult distal radius fractures. For patients aged ≥60 years, the amount of missing radiographic outcomes was positively correlated with age. The receiver operating characteristic curve demonstrated that age ≥65.5 years, ulnar variance >3.26 mm at pre‐reduction, and ulnar variance >2.055 mm at immediate reduction were high‐risk factors for fracture re‐displacement.
Conclusions
Nonsurgical treatment of distal radius fractures exhibits a higher rate of re‐displacement. Age, AO/OTA type, pre‐reduction, and immediate reduction ulnar variance are key factors predicting fracture re‐displacement.
Age, AO/OTA typing, and ulnar variation at presentation and immediate reduction are related factors in fracture re‐displacement prediction. Age over 65.5 years, ulnar variation >3.26 mm at presentation, and ulnar variation >2.055 mm at immediate reduction were high‐risk factors for fracture re‐displacement.
Abstract
Although isolated left vertebral artery is a supra-aortic trunk variant, it is not so rare. It may pose additional difficulties during total arch replacement surgeries. The aim of this study ...was to present our experience with prior reconstruction of isolated left vertebral artery by isolated left vertebral artery–left common carotid artery during total arch replacement combined with stented elephant trunk implantation.
Deep learning (DL) models have demonstrated state-of-the-art performance in the classification of diagnostic imaging in oncology. However, DL models for medical images can be compromised by ...adversarial images, where pixel values of input images are manipulated to deceive the DL model. To address this limitation, our study investigates the detectability of adversarial images in oncology using multiple detection schemes. Experiments were conducted on thoracic computed tomography (CT) scans, mammography, and brain magnetic resonance imaging (MRI). For each dataset we trained a convolutional neural network to classify the presence or absence of malignancy. We trained five DL and machine learning (ML)-based detection models and tested their performance in detecting adversarial images. Adversarial images generated using projected gradient descent (PGD) with a perturbation size of 0.004 were detected by the ResNet detection model with an accuracy of 100% for CT, 100% for mammogram, and 90.0% for MRI. Overall, adversarial images were detected with high accuracy in settings where adversarial perturbation was above set thresholds. Adversarial detection should be considered alongside adversarial training as a defense technique to protect DL models for cancer imaging classification from the threat of adversarial images.
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•Provide correct relative order of acidity among the hydroxyl groups in oxyluciferin.•Propose the mechanism of determining major emissive species.•Explain blue-shift of emission ...spectra based on existence of dominant dianion in basic pH.•Explain the dependence of the emission colors on the excitation energy.
The magnitude of the acidity of the oxyluciferin in water in the ground and excited state is investigated, and it is found for the first time using computational approach that the enol group of the phenol-enol species is the most acidic in the ground state, but the deprotonation of the phenol of the phenol-keto form is the most favored in the excited state. The relative order of the acidity among the hydroxyl groups in the oxyluciferin is attributed to the sequence of the OH bond lengths in the enol and phenol group of the phenol-enol form, and the phenol group of the phenol-keto species. The mechanism of determining the dominant emissive species in the excited state is proposed, and the dependence of emission light colors on the photoexcitation energy is elucidated by the high relative concentration of six chemical forms in the ground state and the absorption efficiency.
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