Heart failure (HF), leading as one of the main causes of mortality, has become a serious public health issue with high prevalence around the world. Single cardiomyocyte (CM) metabolomics promises to ...revolutionize the understanding of HF pathogenesis since the metabolic remodeling in the human hearts plays a vital role in the disease progression. Unfortunately, current metabolic analysis is often limited by the dynamic features of metabolites and the critical needs for high-quality isolated CMs. Here, high-quality CMs were directly isolated from transgenic HF mice biopsies and further employed in the cellular metabolic analysis. The lipids landscape in individual CMs was profiled with a delayed extraction mode in time-of-flight secondary ion mass spectrometry. Specific metabolic signatures were identified to distinguish HF CMs from the control subjects, presenting as possible single-cell biomarkers. The spatial distributions of these signatures were imaged in single cells, and those were further found to be strongly associated with lipoprotein metabolism, transmembrane transport, and signal transduction. Taken together, we systematically studied the lipid metabolism of single CMs with a mass spectrometry imaging method, which directly benefited the identification of HF-associated signatures and a deeper understanding of HF-related metabolic pathways.
Ferroelectric materials are a special type of polar substances, including solids or liquid crystals. However, obtaining a material to be ferroelectric in both its solid crystal (SC) and liquid ...crystal (LC) phases is a great challenge. Moreover, although cholesteric LCs inherently possess the advantage of high fluidity, their ferroelectricity remains unknown. Here, through the reasonable H/F substitution on the fourth position of the phenyl group of the parent nonferroelectric dihydrocholesteryl benzoate, we designed ferroelectric dihydrocholesteryl 4-fluorobenzoate (4-F-BDC), which shows ferroelectricity in both SC and cholesteric LC phases. The fluorination induces a lower symmetric polar P1 space group and a new solid-to-solid phase transition in 4-F-BDC. Beneficial from fluorination, the SC and cholesteric LC phases of 4-F-BDC show clear ferroelectricity, as confirmed by well-shaped polarization–voltage hysteresis loops. The dual ferroelectricity in both SC and cholesteric LC phases of a single material was rarely found. This work offers a viable case for the exploration of the interplay between ferroelectric SC and LC phases and provides an efficient approach for designing ferroelectrics with dual ferroelectricity and cholesteric ferroelectric liquid crystals.
First-principles computation methods play an important role in developing and designing new magnesium alloys.In this article,we present an overview of the first-principles modeling techniques used in ...recent years to simulate ideal models of the structure of strengthening compounds in Mg alloys.For typical Mg compounds,structural stability,mechanical properties,electronic structure and thermodynamic properties have been discussed.Specifically,the elastic anisotropies of these compounds are examined,which is highly correlated with the possibility of inducing micro-cracks.Furthermore,some heterogeneous nucleation interfaces investigated by first-principles method are reviewed.Some of the theoretical results are compared with available experimental observations.We hope to illustrate that the first-principles computation can help to accelerate the design of new Mg-based materials and the development of materials genome initiative.Remaining problems and future directions in this research field are considered.
Although the shell mould casting process has a wide range of application in many fields, the prediction of casting defects is still a problem. In the present work, a typical leaf spring bracket ...casting of ZG310-570 was fabricated by shell mold casting. The finite element model and ProCAST software were utilized for simulating the filling and solidification processes of the casting; and the formation mechanism of the gas pore, and shrinkage porosity defects were analyzed. The results indicate that the gas pore and shrinkage porosity defects are formed due to air entrapment, insufficient feeding and non-sequential solidification. Subsequently, through changing the position of risers, adding a connecting channel between the risers, and setting blind risers at the U-shaped brackets, an optimized gating and feeding system was established to improve the quality of the casting. After optimization, the gas pore and shrinkage porosity defects of the leaf spring bracket casting are effectively eliminated. The experiment results with the optimized casting process are in good agreement with the numerical simulation, which verifies the validity of the finite element model in the shell mould casting.
The critical aggregation concentration（CAC） of four with three kinds of conventional surfactants, namely,two cationic surfactants hexadecyltrimethyl ammonium bromide（CTAB） and tetradecyltrimethyl ...ammonium bromide（TTAB）, one anionic surfactant sodium dodecyl sulfate（SDS）, and a nonionic surfactant Triton X-100（TX-100）, were determined by variation of ^1H chemical shifts with surfactant concentrations. Results show that the CAC values of protons at different positions of the same molecule are different, and those of the terminal methyl protons are the lowest, respectively, which suggests that the terminal groups of the alkyl chains aggregates first during micellization. Measurement of the transverse relaxation time（T2） of different protons in SDS also show that the terminal methyl protons start to decrease with the increase in concentration first, which supports the above mentioned tendency.
Lipid accumulation in podocytes can lead to the destruction of cellular morphology, in addition to cell dysfunction and apoptosis, which is a key factor in the progression of chronic kidney disease ...(CKD). Berberine (BBR) is an isoquinoline alkaloid extracted from medicinal plants such as Coptis chinensis, which has been reported to have a lipid‑lowering effect and prevent CKD progression. Therefore, the present study aimed to investigate the effect of BBR on palmitic acid (PA)‑induced podocyte apoptosis and its specific mechanism using an in vitro model. Cell death was measured using the Cell Counting Kit‑8 colorimetric assay. Cell apoptotic rate was assessed by flow cytometry. The expression of endoplasmic reticulum (ER) stress‑ and apoptosis‑related proteins was detected by western blotting or immunofluorescence. Reactive oxygen species (ROS) were evaluated by 2',7'‑dichlorofluorescein diacetate fluorescence staining. The results of the present study revealed that BBR treatment decreased PA‑induced podocyte apoptosis. In addition, 4‑phenylbutyric acid significantly reduced PA‑induced cell apoptosis and the expression of ER stress‑related proteins, which indicated that ER stress was involved in PA‑induced podocyte apoptosis. In addition, N‑acetylcysteine inhibited PA‑induced excessive ROS production, ER stress and cell apoptosis of podocytes. BBR also significantly reduced PA‑induced ROS production and ER stress in podocytes. These results suggested that PA mediated podocyte apoptosis through enhancing ER stress and the production of ROS. In conclusion, BBR may protect against PA‑induced podocyte apoptosis, and suppression of ROS‑dependent ER stress may be the key mechanism underlying the protective effects of BBR.
Since there were a few articles to report the treatment of severe pulmonary vasoconstriction induced by protamine in cardiac surgery, we described the use of epoprostenol to reverse this condition.A ...total of 5 cases of severe pulmonary vasoconstriction induced by protamine in cardiac surgery were reviewed. The demographic, clinical data and treatment process were obtained. All the patients were followed up.Severe pulmonary vasoconstriction was occurred 4 to 10 minutes after protamine infusion. The primary sign was sudden hypotension, the pulmonary artery pressure was increased gradually, the arterial oxygen partial pressure was decreased in all the patients. Epoprostenol was infused via pulmonary artery catheter at dosage of 20 to 40 ng/kg·min in all the patients, 2 patients were underwent re-cardiac pulmonary bypass assistance. The hemodynamic instability status lasted 40 to 65 minutes respectively. All the patients were recovered uneventfully.All physicians should alert to the incidence of severe pulmonary vasoconstriction induced by protamine in cardiac surgery. Use epoprostenol through pulmonary artery catheter could treat pulmonary artery vasoconstriction effectively and safely.
A series of six CdII coordination complexes have been prepared by using naphthalene-2,3-dicarboxylic acid (H2 ndc), an analogue of 1,2-benzenedicarboxylic acid (H2 bdc), and different N-donor ...auxiliary co-ligands (chelating or bridging), namely, Cd(ndc)∞ (1), {Cd2(ndc)2(2bpy)2(H2O)2(CH3OH)0.5}2 (2), Cd2(ndc)2(phen)2∞ (3), {Cd(ndc)(4bpy)0.5(H2O)2(H2O)}∞ (4), {Cd(ndc)(abp)(H2O)(H2O)}∞ (5), and {Cd(ndc)(bpp)2(H2O)3}∞ (6) (ndc = naphthalene-2,3-dicarboxylate, 2bpy = 2,2′-bipyridine, phen = 1,10-phenanthroline, 4bpy = 4,4′-bipyridine, abp = trans-4,4′-azobis(pyridine), and bpp = 1,3-bis(4-pyridyl) propane). The initial complex 1 shows a two-dimensional (2-D) (44.62) coordination network. 2 and 3 possess tetranuclear and one-dimensional (1-D) structures due to the incorporation of auxiliary chelating co-ligands 2bpy and phen, respectively, which are further interlinked via secondary interactions such as hydrogen bonding and aromatic stacking to result in higher-dimensional supramolecular networks. When the 4,4′-dipyridyl-type bridging co-ligands 4bpy, abp, and bpp (with different N,N′-donor separations of the molecular backbones from ca. 7−10 Å) were used as the additional rod-like linkers, a 2-D (3,4)-connected (42.6)(42.63.8) layered coordination net 4 as well as a three-dimensional (3-D) coordination framework 5 with an unusual 4-connected irl topology (42.63.8) and a homochiral 3-D diamond (dia) network 6 were obtained. A structural comparison of these complexes with those based on the structurally related ligand 1,2-benzenedicarboxylate (bdc) suggests that the extended π-conjugated system of ndc with a different electronic nature and steric bulk plays an important role in the construction of supramolecular architectures for 1−6, which can also be well regulated by the different chelating or bridging N-donor co-ligands. Moreover, complexes 1−6 exhibit strong solid-state luminescence emissions at room temperature, which mainly originate from the intraligand π → π* transitions of ndc.
The significant Tc enhancement of 110 K in N-fluoromethyldabconium triiodide lead caused by the promising design of H/F substitution is the first and unprecedented, opening up an applicable and ...universal strategy to effectively regulate the Tc working temperature in phase transition materials.
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