Search

Malignant cells exhibit a high demand for amino acids to sustain their abnormal proliferation. Particularly, the intracellular accumulation of cysteine is often observed in cancer cells. Previous studies have shown that deprivation of intracellular cysteine in cancer cells results in the accumulation of lipid peroxides in the plasma membrane and induction of ferroptotic cell death, indicating that cysteine plays a critical role in the suppression of ferroptosis. Herein, we found that the oncogenic accumulation of cysteine also contributes to cancer cell proliferation by promoting the cell cycle progression, which is independent of its suppressive effect on ferroptosis. The growth ability of four types of cancer cells, including murine hepatocarcinoma cells, but not of primary hepatocytes, were dependent on the exogenous supply of cysteine. Deprivation of intracellular cysteine in cancer cells induced cell cycle arrest at the G0/G1 phase, accompanied by a decrease in the expression of cyclin D1 and D2 proteins. The cysteine deprivation-induced decrease in D-type cyclin expression was associated with the upregulation of eukaryotic translation initiation factor 4E binding protein 1, which represses the translation of cyclin D1 and D2 proteins by binding to eukaryotic translation initiation factor 4E. Similar results were observed in hepatocarcinoma cells treated with erastin, an inhibitor of cystine/glutamate antiporter, xCT. These findings reveal an unappreciated role of cysteine in regulating the growth of malignant cancer cells and deepen our understanding of the cytotoxic effect of xCT inhibitor to prevent cancer cell proliferation., Competing Interests: Conflict of interest The authors declare that they have no conflicts of interest with the contents of this article., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Mg-Al layered double hydroxides (LDHs) with CO 3 2- interlayer anions are promising CO 2 adsorbents. Here, we analyzed the quantitative gas evolution behaviors of Mg-Al LDH particles with different Mg/Al ratios during the multistep chemical/structural transformations at elevated temperatures. The Mg/Al molar ratio strongly affects the behavior: the transformation changes from two apparent steps to three steps depending on the Mg/Al ratio. The transformation occurs in essentially the same way as that observed for large Mg-Al LDH crystals: (1) release of the interlayer water, (2) partial dehydroxylation of the hydroxyl layers followed by coordination of carbonate ions to the metals, and (3) collapse of the layered structure. We provide a molecular/atomic level picture of the structure in each step of the transformation by first-principles density functional theory (DFT) calculation. The structurally optimized model and reexamination of experimental data showed that step (1) results in a large decrease in the interlayer distance of the LDH from ∼7.6 to ∼6.7 Å (a decrease of ∼0.9 Å) and the possible explanation is the waving of the metal hydroxide layers. This study provides a comprehensive understanding of the structural changes of LDHs with various Mg/Al ratios to resolve the various interpretations in the literature.

An organometallic nickel complex containing thieno[3,2- b ]thiophene units was designed and synthesized. Composite films of the resulting nickel complex and polyvinylidene difluoride, which can be fabricated via a simple solution process under atmospheric conditions, exhibit remarkably high n-type conductivity (>200 S cm -1 ). Moreover, the thermoelectric power factor of the n-type composite film was proven to be air stable. A grazing-incidence wide-angle X-ray diffraction analysis indicated a significant impact of introducing the thieno[3,2- b ]thiophene core into the backbone of the nickel complex on the orientation within the composite films.

The same iron pot in which their father had boiled lead with mercury (from a glass thermometer) for the purpose of alchemy, was also used for cooking in the kitchen. Although his wife had died of mercury poisoning, and his 14-year-old and 11-year-old daughters were found to excrete 322 and 455 micrograms/l mercury in the urine, respectively, (1-10 micrograms/l in controls), he stubbornly refused to give permission for them to be examined further. Nine months later, the daughters were permitted to be sent to our clinical ward. While the blood level of mercury had already come down to near normal, its excessive deposition in hair, kidneys and other parts of the body as well as its excessive urinary excretion, were still persistent (beyond tenfold the normal). According to our measurement values, mercury ranged from 14 to 49 micrograms/g in every 1-cm-piece of 10 cm hair of the elder sister, and ranged from 21 to 85 micrograms/g in 14 cm hair from the younger sister. About a 75% decrease in mercury deposition was estimated during these 9 months, based on the speculation of 1.5 cm/month hair-lengthening.

Bilirubin and its photoisomers in the biological fluids of a hyperbilirubinaemic newborn infant before and during phototherapy were analyzed by a recently improved HPLC method. In the serum, the percentages of (EZ)- and (ZE)-bilirubin in the total bilirubin concentration before phototherapy were approximately 10% and on average increased over 1.5-fold at 2 h after initiation of phototherapy. The percentage of the (EZ)-cyclobilirubin in the serum bilirubin was under 1%. In the bile, the mean concentration of (ZZ)-bilirubin, derived mainly from (ZE)-bilirubin, nearly tripled during phototherapy. The (EZ)-cyclobilirubin concentration in the bile was very low before phototherapy, increased nearly ten-fold at 3 h after initiation of phototherapy, and was 5- to 6-fold as high as that of (ZZ)-bilirubin. In the urine, upon exposure to light, the urinary concentration of (EZ)-cyclobilirubin is apparently equivalent to half of the biliary concentration of (ZZ)-bilirubin and one-fifth of that of (EZ)-cyclobilirubin. It was concluded that during phototherapy of neonatal hyperbilirubinaemia the structural photoisomer [(EZ)-cyclobilirubin] predominates considerably over the geometric photoisomer [(ZE)-bilirubin].