Unconventional hcp/fcc Nickel Heteronanocrystal with Asymmetric Convex Sites Boosts Hydrogen Oxidation.

Developing non-platinum group metal catalysts for the sluggish hydrogen oxidation reaction (HOR) is critical for alkaline fuel cells. To date, Ni-based materials are the most promising candidates but still suffer from insufficient performance. Herein, we report an unconventional hcp/fcc Ni (u-hcp/fcc Ni) heteronanocrystal with multiple epitaxial hcp/fcc heterointerfaces and coherent twin boundaries, generating rugged surfaces with plenty of asymmetric convex sites. Systematic analyses discover that such convex sites enable the adsorption of *H in unusual bridge positions with weakened binding energy, circumventing the over-strong *H adsorption on traditional hollow positions, and simultaneously stabilizing interfacial *H2O. It thus synergistically optimizes the HOR thermodynamic process as well as reduces the kinetic barrier of the rate-determining Volmer step. Consequently, the developed u-hcp/fcc Ni exhibits the top-rank alkaline HOR activity with a mass activity of 40.6 mA mgNi-1 (6.3 times higher than fcc Ni control) together with superior stability and high CO-tolerance. These results provide a paradigm for designing high-performance catalysts by shifting the adsorption state of intermediates through configuring surface sites.

The role of ultraviolet radiation in the flavor formation during drying processing of Pacific saury (Cololabis saira).

BACKGROUND: Traditional sun-drying aquatic products are popular and recognized by customers, owing to their unique flavor and long-term preservation. However, the product quality and production efficiency cannot be guaranteed. Cololabis saira is rich in unsaturated fatty acids, which are susceptible to hyperoxidation during the drying process. This study aimed to make clear the role of ultraviolet (UV) radiation in flavor formation during drying processes of Cololabis saira to develop a modern drying technology. RESULTS: Lipid oxidation analysis revealed that moderate hydrolytic oxidation occurred in the UV-assisted cold-air drying group due to the combined influence of UV and cold-air circulation, resulting in the thiobarbituric acid reactive substances value being higher than that of cold-air drying group but lower than the natural drying group. Hexanal, heptanal, cis-4-heptenal, octanal, nonanal, (trans,trans)-2,4-heptadienal, (trans,trans)-2,6-nonanedial, 1-octen-3-ol, heptanol, 2,3-pentanedione, 3,5-octadien-2-one and trimethylamine were identified as the characteristic flavor odor-active compounds present in all Cololabis saira samples. Yet, during the natural drying process, sunlight promoted the lipid oxidation, resulting in the highest degree of lipid oxidation among three drying methods. Light and heat promoted lipid oxidation in Cololabis saira prepared through natural drying process, leading to a large accumulation of volatile compounds, such as 3-methylbutyraldehyde, 2,3-pentanedione, 1-propanol, and 3-pentanone. Cold air circulation inhibited lipid oxidation to some extent, resulting in a blander flavor profile. More cis-4-heptenal, cis-2-heptenal, octanal and 2-ethylfuran accumulated during the UV-assisted cold-air drying process, enriching its greasy flavor and burnt flavor. CONCLUSION: UV-assisted cold-air drying could promote moderate lipid oxidation, which is beneficial for improving product flavor. To sum up, UV radiation played a crucial role in the flavor formation during the drying process of Cololabis saira. © 2024 Society of Chemical Industry.

Atomically Resolved Transition Pathways of Iron Redox.

The redox transition between iron and its oxides is of the utmost importance in heterogeneous catalysis, biological metabolism, and geological evolution. The structural characteristics of this reaction may vary based on surrounding environmental conditions, giving rise to diverse physical scenarios. In this study, we explore the atomic-scale transformation of nanosized Fe3O4 under ambient-pressure H2 gas using in-situ environmental transmission electron microscopy. Our results reveal that the internal solid-state reactions dominated by iron diffusion are coupled with the surface reactions involving gaseous O or H species. During reduction, we observe two competitive reduction pathways, namely Fe3O4 → FeO → Fe and Fe3O4 → Fe. An intermediate phase with vacancy ordering is observed during the disproportionation reaction of Fe2+ → Fe0 + Fe3+, which potentially alleviates stress and facilitates ion migration. As the temperature decreases, an oxidation process occurs in the presence of environmental H2O and trace amounts of O2. A direct oxidation of Fe to Fe3O4 occurs in the absence of the FeO phase, likely corresponding to a change in the water vapor content in the atmosphere. This work elucidates a full dynamical scenario of iron redox under realistic conditions, which is critical for unraveling the intricate mechanisms governing the solid-solid and solid-gas reactions.

A comprehensive study of the colloidal properties, biocompatibility, and synergistic antioxidant actions of Antarctic krill phospholipids.

Excipient selection is crucial to address the oxidation and solubility challenges of bioactive substances, impacting their safety and efficacy. AKPL, a novel ω-3 polyunsaturated fatty acids (PUFAs) esterified phospholipid derived from Antarctic krill, demonstrates unique antioxidant capabilities and synergistic effects. It exhibits pronounced surface activity and electronegativity at physiological pH, as evidenced by a critical micelle concentration (CMC) of 0.15 g/L and ζ-potential of -49.9 mV. In aqueous environments, AKPL self-assembles into liposomal structures, offering high biocompatibility and promoting cell proliferation. Its polyunsaturated bond-rich structure provides additional oxidation sites, imparting antioxidant properties superior to other phospholipids like DSPC and DOPC. Additionally, AKPL augments the efficacy of lipophilic antioxidants, such as alpha-tocopherol and curcumin, in aqueous media through both intermolecular and intramolecular interactions. In sum, AKPL emerges as an innovative unsaturated phospholipid, offering new strategies for encapsulating and delivering oxygen-sensitive agents.

Anhydrous Alum Inhibits α-MSH-Induced Melanogenesis by Down-Regulating MITF via Dual Modulation of CREB and ERK.

Melanogenesis, the intricate process of melanin synthesis, is central to skin pigmentation and photoprotection and is regulated by various signaling pathways and transcription factors. To develop potential skin-whitening agents, we used B16F1 melanoma cells to investigate the inhibitory effects of anhydrous alum on melanogenesis and its underlying molecular mechanisms. Anhydrous alum (KAl(SO4)2) with high purity (>99%), which is generated through the heat-treatment of hydrated alum (KAl(SO4)2·12H2O) at 400 °C, potentiates a significant reduction in melanin content without cytotoxicity. Anhydrous alum downregulates the master regulator of melanogenesis, microphthalmia-associated transcription factor (MITF), which targets key genes involved in melanogenesis, thereby inhibiting α-melanocyte-stimulating hormone (α-MSH)-induced melanogenesis. Phosphorylation of the cAMP response element-binding protein, which acts as a co-activator of MITF gene expression, is attenuated by anhydrous alum, resulting in compromised MITF transcription. Notably, anhydrous alum promoted extracellular signal-regulated kinase phosphorylation, leading to the impaired nuclear localization of MITF. Overall, these results demonstrated the generation and mode of action of anhydrous alum in B16F1 cells, which constitutes a promising option for cosmetic or therapeutic use.

[Analysis of 59 cases of large vestibular aqueduct syndrome SLC26A4gene mutation frequency and new mutation sites].

Objective:To study the frequency of SLC26A4 gene mutation sites in children with enlarged vestibular aqueduct deafness in Yunnan, report the new mutation sites of SLC26A4 gene, further clarify the mutation spectrum of SLC26A4gene, and explore the association between biallelic and monoallelic mutations of SLC26A4 gene and CT phenotype of inner ear, so as to provide basis for clinical and genetic diagnosis of deafness. Methods:Review the results of temporal bone CT examination of 390 children after cochlear implantation in the Department of Otolaryngology, Kunming Children's Hospital from August 2016 to September 2021. Sanger sequencing of SLC26A4 gene was performed in 59 children with enlarged vestibular aqueduct. According to the genetic test results, the children who underwent temporal bone CT examination were divided into two groups: SLC26A4 biallelic mutation group（homozygous mutation and compound heterozygous mutation）, monoallelic mutation group, and the association with inner ear CT phenotype was analyzed, and the new sites were summarized and analyzed. Results:The c.919-2a>g mutation was the most common mutation in children with enlarged vestibular aqueduct with SLC26A4 gene mutation. Three new variants of SLC26A4 gene were found; CT examination combined with genetic testing found that a part of children with enlarged vestibular aqueduct was associated with SLC26A4 monoallelic mutation or no SLC26A4 gene mutation was detected. Further research is needed to investigate the involvement of other pathogenic factors in the pathogenesis of EVA.

Endovascular treatment for massive haemoptysis due to pulmonary pseudoaneurysm: report of 23 cases.

PURPOSE: To evaluate the safety and effectiveness of endovascular treatment for massive haemoptysis caused by pulmonary pseudoaneurysm (PAP). METHODS: The clinical data, imaging data, and endovascular treatment protocol of 23 patients with massive haemoptysis caused by continuous PAP were retrospectively analysed. The success, complications, postoperative recurrence rate, and influence of the treatment on pulmonary artery pressure were also evaluated. RESULTS: Nineteen patients with a bronchial artery-pulmonary artery (BA-PA) and/or nonbronchial systemic artery-pulmonary artery (NBSA-PA) fistula underwent bronchial artery embolization (BAE) and/or nonbronchial systemic artery embolization (NBSAE) + pulmonary artery embolization (PAE). The pulmonary artery (PA) pressures before and after embolization were 52.11 ± 2.12 (35-69 cmH2O) and 33.58 ± 1.63 (22-44 cmH2O), respectively (P = 0.001). Four patients did not have a BA-PA and/or NBSA-PA fistula. Embolization was performed in two patients with a distal PAP of the pulmonalis lobar arteria. Bare stent-assisted microcoils embolization was performed in the other two patients with a PAP of the main pulmonary lobar arteries. The PA pressures of the four patients before and after treatment were 24.50 ± 1.32 (22-28 cmH2O) and 24.75 ± 1.70 (22-29 cmH2O), respectively (P = 0.850). The technique had a 100% success rate with no serious complications and a postoperative recurrence rate of 30%. CONCLUSION: Endovascular treatment is safe and effective for massive haemoptysis caused by PAP. BAE and/or NBSAE can effectively reduce pulmonary hypertension in patients with a BA-PA and/or NBSA-PA fistula.

H2S Alleviates Neuropathic Pain in Mice by Nrf2 Signaling Pathway Activation.

Neuropathic pain is a chronic pain caused by direct damage to the peripheral or central nervous system, characterized by hyperalgesia, allodynia, and spontaneous pain. Hydrogen sulfide (H2S) therapy has been applied for neuropathic pain treatment, although the underlying mechanisms remain unknown. In this study, we sought to ascertain whether H2S therapy could alleviate neuropathic pain in a model of chronic constriction injury (CCI) and, if so, the potential mechanism. A CCI model was established in mice through a spinal nerve ligation method. Intrathecal injection of NaHS was used to treat CCI model mice. The thermal paw withdrawal latency (TPWL) and mechanical paw withdrawal threshold (MPWT) were used for pain threshold evaluation in mice. A series of experiments including immunofluorescence, enzyme-linked immunosorbent assay, electrophysiological test, mitochondrial DNA (mtDNA) quantification, measurement of ATP content, demethylase activity, and western blot were performed to investigate the specific mechanism of H2S treatment in neuropathic pain. Mice with CCI exposure exhibited a decrease in MPWT and TPWL, an increase in IL-1ß and TNF-α expressions, elevated eEPSP amplitude, an upregulation of mtDNA, and a reduction in ATP production, whereas H2S treatment significantly reversed these changes. Furthermore, CCI exposure induced a remarkable increase in vGlut2- and c-fos-positive as well as vGlut2- and Nrf2-positive cells, an increase in Nrf2 located in the nucleus, and an upregulation of H3K4 methylation, and H2S treatment further enhanced these changes. In addition, ML385, a selective Nrf2 inhibitor, reversed the neuroprotective effects of H2S. H2S treatment mitigates CCI-induced neuropathic pain in mice. This protective mechanism is possibly linked to the activation of the Nrf2 signaling pathway in vGlut2-positive cells.

Renal-clearable porous hollow copper iron oxide nanoparticles for trimodal chemodynamic-photothermal-chemo anti-tumor therapy.

Multifunctional nanoplatforms with the synergistic effects of multiple therapeutic modalities have become a research focus due to their superior anti-tumor properties over single therapeutic modalities. Herein, we developed around 14 nm porous hollow copper iron oxide nanoparticles (PHCuFeNPs) with pore sizes of around 2-3 nm as a cisplatin carrier and photothermal therapeutic agent. The PHCuFeNPs were synthesized via a galvanic reaction between Cu2S nanoparticles and iron pentacarbonyl (Fe(CO)5) followed by etching in the organic phase to make the pores. They were stable under normal physiological conditions, but the pores were etched in a weak acidic tumor microenvironment, resulting in the controlled release of Cu and Fe ions for enhanced chemodynamic therapy and accelerated cisplatin release for chemotherapy. Under 980 nm laser irradiation, the PHCuFeNPs could effectively heat up to further promote the release process for synergistic therapy. Besides, they were proved to mediate immunogenic cell death to activate the immune system for potential immunotherapy. Together with their ability to degrade into fragments for fast renal metabolism, we believe that these PHCuFeNPs could provide a biocompatible and efficient multi-antitumor therapeutic approach.

MUC1 promotes glioblastoma progression and TMZ resistance by stabilizing EGFRvIII.

Epidermal growth factor receptor variant III (EGFRvIII) is a mutant isoform of EGFR with a deletion of exons 2-7 making it insensitive to EGF stimulation and downstream signal constitutive activation. However, the mechanism underlying the stability of EGFRvIII remains unclear. Based on CRISPR-Cas9 library screening, we found that mucin1 (MUC1) is essential for EGFRvIII glioma cell survival and temozolomide (TMZ) resistance. We revealed that MUC1-C was upregulated in EGFRvIII-positive cells, where it enhanced the stability of EGFRvIII. Knockdown of MUC1-C increased the colocalization of EGFRvIII and lysosomes. Upregulation of MUC1 occurred in an NF-κB dependent manner, and inhibition of the NF-κB pathway could interrupt the EGFRvIII-MUC1 feedback loop by inhibiting MUC1-C. In a previous report, we identified AC1Q3QWB (AQB), a small molecule that could inhibit the phosphorylation of NF-κB. By screening the structural analogs of AQB, we obtained EPIC-1027, which could inhibit the NF-κB pathway more effectively. EPIC-1027 disrupted the EGFRvIII-MUC1-C positive feedback loop in vitro and in vivo, inhibited glioma progression, and promoted sensitization to TMZ. In conclusion, we revealed the pivotal role of MUC1-C in stabilizing EGFRvIII in glioblastoma (GBM) and identified a small molecule, EPIC-1027, with great potential in GBM treatment.

Wandering small intestinal stromal tumor: A case report.

BACKGROUND: The occurrence of gastrointestinal stromal tumors (GISTs) in the small intestine is rare, and a case of wandering small intestinal stromal tumor has been rarely reported to date. Dissemination of this case can help inform future diagnosis and effective treatment. CASE SUMMARY: A 68-year-old patient presented to us with tarry stools. Computed tomography showed a mobile tumor moving widely within the abdominal cavity. As the laboratory data showed a low range of red blood cells and an immediate surgery was not indicated, we performed digital subtraction angiography and embolization to achieve hemostasis. Surgical resection was performed after the patient's condition improved. The tumor was successfully removed laparoscopically. Histological examination revealed submucosal GIST with infarction, which was of intermediate-risk, with mitotic count < 1 per 10 high-power field. Immunohistochemical studies revealed the following: CD117+, Dog1+, CD34+, SMA+, S100-, CK-, Des-, SOX-11-, STAT6-, Ki67 Hotspots 10%+. The patient was ultimately diagnosed with wandering small intestinal stromal tumor. CONCLUSION: When a highly vascularized tumor is clinically encountered in the small intestine, the possibility of stromal tumors should be considered. However, when the tumor cannot be visualized at its original location, the possibility of tumor migration is considered.

Thymus Functionality Needs More Than a Few TECs.

The thymus, a primary lymphoid organ, produces the T cells of the immune system. Originating from the 3rd pharyngeal pouch during embryogenesis, this organ functions throughout life. Yet, thymopoiesis can be transiently or permanently damaged contingent on the types of systemic stresses encountered. The thymus also undergoes a functional decline during aging, resulting in a progressive reduction in naïve T cell output. This atrophy is evidenced by a deteriorating thymic microenvironment, including, but not limited, epithelial-to-mesenchymal transitions, fibrosis and adipogenesis. An exploration of cellular changes in the thymus at various stages of life, including mouse models of in-born errors of immunity and with single cell RNA sequencing, is revealing an expanding number of distinct cell types influencing thymus functions. The thymus microenvironment, established through interactions between immature and mature thymocytes with thymus epithelial cells (TEC), is well known. Less well appreciated are the contributions of neural crest cell-derived mesenchymal cells, endothelial cells, diverse hematopoietic cell populations, adipocytes, and fibroblasts in the thymic microenvironment. In the current review, we will explore the contributions of the many stromal cell types participating in the formation, expansion, and contraction of the thymus under normal and pathophysiological processes. Such information will better inform approaches for restoring thymus functionality, including thymus organoid technologies, beneficial when an individuals' own tissue is congenitally, clinically, or accidentally rendered non-functional.

Development, characterization and in vitro bile salts binding capacity of selenium nanoparticles stabilized by soybean polypeptides.

The paper presents the positive effect of soybean polypeptides (SP) on the stability and the potential hypolipidemic effect of selenium nanoparticles (SeNPs). After preparing SeNPs, SP with different molecular weight were introduced to stabilize SeNPs. We found that the SP with molecular weight >10 kDa (SP5) had the best stabilizing effect on SeNPs. We inferred that the steric resistance resulting from the long chains of SP5 protected SeNPs from collision-mediated aggregation, and the electrostatic repulsions between SP5 and SeNPs also played a positive role in stabilizing SeNPs. The as-prepared SP5-SeNPs were spherical, amorphous and zero valent. It was proved that SeNPs were bound with SP5 through O- and N- groups in SP5, and the main forces were hydrogen bonds and van der Waals forces. The bile salts binding assay showed that the SP5-SeNPs exhibited a high binding capacity to bile salts, which indicated their potential in hypolipidemic application.

[Effects of Xiangqin Jiere Granules on lipid metabolism and chronic inflammation in different obesity model mice].

This paper aims to study the effect of Xiangqin Jiere Granules(XQ) on lipid metabolism and chronic inflammation in different obesity model mice. The monosodium glutamate(MSG) obese mouse model was established by subcutaneous injection of MSG in newborn mice, and the high fat diet(HFD) obese mouse model was established by feeding adult mice with HFD. The normal mice were assigned into the control group; the MSG obese mice were assigned into MSG model group, XQ4.5 group(Xiangqin Jiere Granu-les, 4.5 g·kg~(-1)), XQ22.5 group(Xiangqin Jiere Granules, 22.5 g·kg~(-1)); the HFD obese mice were assigned into HFD model group, XQ4.5 group, and XQ22.5 group. The mice were intragastrically administrated with saline or XQ for 5 weeks. After that, the body weight, visceral fat mass, liver and thymus weight, and the organ indexes in each group were measured. The levels of triglyceride(TG), total cholesterol(TC), and low-density lipoprotein cholesterol(LDL-c) in serum and liver tissue were detected by the kits. The mRNA expression levels of acetyl CoA carboxylase 1(ACC1), fatty acid synthetase(FAS), diacylgycerol acyltransferase 1(DGAT1) and hepatic lipase(HTGL) involved in lipid metabolism in mouse liver tissue were detected by quantitative real-time PCR(qPCR). The protein levels of tumor necrosis factor-α(TNF-α) and interleukin-6(IL-6) in serum were detected by ELISA, and the mRNA levels of TNF-α and IL-6 in liver tissue were detected by qPCR. Compared with the control group, MSG and HFD mice showed increased body weight, abdominal circumference, Lee index and visceral fat mass as well as elevated levels of TG, TC, and LDL-c in serum. The model mice had up-regulated gene levels of ACC1, FAS and DGAT1 while down-regulated gene level of HTGL in the liver. Furthermore, the mRNA and protein levels of IL-6 increased in the model mice. Compared with the model mice, XQ treatment decreased the body weight, abdominal circumference, Lee index, and visceral fat mass, lowered the levels of TG, TC, and LDL-c in se-rum, down-regulated the gene levels of ACC1, FAS, and DGAT1 in liver tissue, up-regulated the gene level of HTGL, and down-regulated the mRNA and protein levels of IL-6. To sum up, XQ has good therapeutic effect on different obesity model mice. It can improve lipid metabolism and reduce fat accumulation in obese mice by regulating the enzymes involved in lipid metabolism, and alleviate obesity-related chronic low-grade inflammation.

Relativistic DFT Probe for Reaction Energies and Electronic/Bonding Properties of Polypyrrolic Hetero-Bimetallic Actinide Complexes: Effects of Uranyl endo-Oxo Functionalization.

A series of hetero-bimetallic actinide complexes of the Schiff-base polypyrrolic macrocycle (L), featuring cation-cation interactions (CCIs), were systematically investigated using relativistic density functional theory (DFT). The tetrahydrofuran (THF) solvated complex [(THF)(OUVIOUIV)(THF)(L)]2+ has high reaction free energy (ΔrG), and its replacement with electron-donating iodine promotes the reaction thermodynamics to obtain uranyl iodide [(I)(OUVIOUIV)(I)(L)]2+ (UVI-UIV). Retaining this coordination geometry, calculations have been extended to other An(IV) (An = Th, Pa, Np, Pu), i.e., for the substitution of U(IV) to obtain UVI-AnIV. As a consequence, the reaction free energy is appreciably lowered, suggesting the thermodynamic feasibility for the experimental synthesis of these bimetallic complexes. Among all UVI-AnIV, the electron-spin density and high-lying occupied orbitals of UVI-PaIV show a large extent of electron transfer from electron-rich Pa(IV) to electron-deficient U(VI), leading to a more stable UV-PaV oxidation state. Additionally, the shortest bond distance and the comparatively negative Eint of the Pa-Oendo bond suggest more positive and negative charges (Q) of Pa and endo-oxo atoms, respectively. As a result of the enhanced Pa-Oendo bond and strong CCI in UVI-PaIV along with the corresponding lowest reaction free energy among all of the optimized complexes, uranyl species is a better candidate for the experimental synthesis in the ultimate context of environmental remediation.

Construction of a comprehensive nutritional index and comparison of its prognostic performance with the PNI and NRI for survival in older patients with nasopharyngeal carcinoma: a retrospective study.

OBJECTIVES: To explore the relationship between the Comprehensive Nutritional Index (CNI) and survival in older patients with nasopharyngeal carcinoma (NPC) and to compare the prognostic performance of three nutritional indicators (CNI, Prognostic Nutritional Index (PNI), and Nutritional Risk Index (NRI)) for overall survival (OS). METHODS: This retrospective study involved 309 older NPC patients in Guangzhou (China) from November 2006 to November 2017. The CNI comprised five parameters: the body mass index (BMI), usual body weight percentage (UBW%), hemoglobin (Hb) level, albumin level, and total lymphocyte count (TLC). All single nutritional indicators were evaluated before and immediately after treatment. The principal component analysis (PCA) was used for calculation of the CNI by single nutritional indicators after treatment. The cutoff point for the CNI was evaluated and logistic regression used to explore the risk factors for the CNI. Univariable, multivariable Cox regression, and Kaplan-Meier methods were applied for OS and disease-free survival (DFS) analyses. Cox proportional hazards models were used to compare the prognostic value of the CNI, PNI, and NRI for OS. RESULTS: All single nutritional indicators decreased significantly after treatment (P < 0.05). The CNI cutoff point for mortality was 0.027, and the logistic regression indicated more complex treatments or higher cancer stage for NPC was associated with a low CNI (HR = 0.179; 95% CI: 0.037-0.856; 0.545, 0.367-0.811, respectively). In multivariable Cox regression, the CNI remained an independent prognostic factor of OS and DFS (HR = 0.468, 95% CI: 0.263-0.832; 0.527, 0.284-0.977, respectively). Kaplan-Meier curves showed that a low CNI was associated with worse OS and DFS (P = 0.001 and 0.013, respectively). The prognostic predictive performance of the CNI was superior to that of the PNI or NRI. CONCLUSIONS: The CNI can be recommended as an appropriate indicator reflecting the integrated nutritional status of older NPC patients. A low CNI predicted a poor survival outcome and the prognostic performance of CNI was superior to PNI or NRI.

Main-Group Metals Stabilized Polypyrrolic Uranyl(V) Complexes via Cation-Cation Interaction with the Uranyl exo-Oxo Atom: A Relativistic Density Functional Theory Study.

To explore the innovative uranyl(V) complexes by deeply understanding their coordination stability, relativistic density functional theory calculations have been performed to investigate the experimentally reported [(py)(R2AlOUVO)(py)(H2L)] [R = Me (1), iBu (2)] and [{(py)3MOUVO}(py)(H2L)] [M = Li (3), Na (4), K (5)] and their uranyl(VI) counterparts. Structural and topological analyses along with transformation-reaction energies and redox potentials were systematically studied. Geometrical and quantum theory of atoms in molecules analyses implied a linear U-Oexo-M feature in 1-3 and a bent one in 4 and 5. The calculated free energies (ΔrG) of reactions transforming 1/2 into 3/4/5 confirmed a higher stability of the latter ones, which were further corroborated by their reduction potentials (E0). The E0 value of 5 versus uranyl(VI) is close to its experimental value, particularly in solvation with spin-orbit coupling. The highest occupied and lowest unoccupied molecular orbitals of uranyl(V) and uranyl(VI) have predominant U(5fδ) character. Compared to mononuclear uranyl(VI), the coordination of aluminum and alkali metals to uranyl exo-oxo significantly contributes to the stabilization of uranyl(V) by altering the E0 value from -1.59 to -0.85, -0.91, -1.33, -1.50, and -1.46 V, respectively. The calculation results show a more positive E0 than that of the precursor 6VI/6 without exo-oxo coordination. The calculated E0 values of 3-5 are certainly more negative than those of 1 and 2. The alkali metals were found to activate U═O bonds more easily/readily than aluminum by coordination to the exo-oxo atom. In brief, the uranyl exo-oxo cation-cation-interaction enhanced the reduction ability from its uranyl(VI) analogue and raised the stability of the UV center.

Mesenchymal stem cell-based Smad7 gene therapy for experimental liver cirrhosis.

BACKGROUND: Bone mesenchymal stem cells (MSCs) can promote liver regeneration and inhibit inflammation and hepatic fibrosis. MSCs also can serve as a vehicle for gene therapy. Smad7 is an essential negative regulatory gene in the TGF-ß1/Smad signalling pathway. Activation of TGF-ß1/Smad signalling accelerates liver inflammation and fibrosis; we therefore hypothesized that MSCs overexpressing the Smad7 gene might be a new cell therapy approach for treating liver fibrosis via the inhibition of TGF-ß1/Smad signalling. METHODS: MSCs were isolated from 6-week-old Wistar rats and transduced with the Smad7 gene using a lentivirus vector. Liver cirrhosis was induced by subcutaneous injection of carbon tetrachloride (CCl4) for 8 weeks. The rats with established liver cirrhosis were treated with Smad7-MSCs by direct injection of cells into the main lobes of the liver. The expression of Smad7, Smad2/3 and fibrosis biomarkers or extracellular matrix proteins and histopathological change were assessed by quantitative PCR, ELISA and Western blotting and staining. RESULTS: The mRNA and protein level of Smad7 in the recipient liver and serum were increased after treating with Smad-MSCs for 7 and 21 days (P < 0.001). The serum levels of collagen I and III and collagenase I and III were significantly (P < 0.001) reduced after the treatment with Smad7-MSCs. The mRNA levels of TGF-ß1, TGFBR1, α-SMA, TIMP-1, laminin and hyaluronic acid were decreased (P < 0.001), while MMP-1 increased (P < 0.001). The liver fibrosis score and liver function were significantly alleviated after the cell therapy. CONCLUSIONS: The findings suggest that the MSC therapy with Smad7-MSCs is effective in the treatment of liver fibrosis in the CCl4-induced liver cirrhosis model. Inhibition of TGF-ß1 signalling pathway by enhancement of Smad-7 expression could be a feasible cell therapy approach to mitigate liver cirrhosis.

Direct Observation of Defect-Aided Structural Evolution in a Nickel-Rich Layered Cathode.

Ni-rich LiNi1-x-y Mnx Coy O2 (NMC) layered compounds are the dominant cathode for lithium ion batteries. The role of crystallographic defects on structure evolution and performance degradation during electrochemical cycling is not yet fully understood. Here, we investigated the structural evolution of a Ni-rich NMC cathode in a solid-state cell by in situ transmission electron microscopy. Antiphase boundary (APB) and twin boundary (TB) separating layered phases played an important role on phase change. Upon Li depletion, the APB extended across the layered structure, while Li/transition metal (TM) ion mixing in the layered phases was detected to induce the rock-salt phase formation along the coherent TB. According to DFT calculations, Li/TM mixing and phase transition were aided by the low diffusion barriers of TM ions at planar defects. This work reveals the dynamical scenario of secondary phase evolution, helping unveil the origin of performance fading in Ni-rich NMC.

Revealing Reaction Pathways of Collective Substituted Iron Fluoride Electrode for Lithium Ion Batteries.

Metal fluorides present a high redox potential among the conversion-type compounds, which make them specially work as cathode materials of lithium ion batteries. To mitigate the notorious cycling instability of conversion-type materials, substitutions of anion and cation have been proposed but the role of foreign elements in reaction pathway is not fully assessed. In this work, we explored the lithiation pathway of a rutile-Fe0.9Co0.1OF cathode with multimodal analysis, including ex situ and in situ transmission electron microscopy and synchrotron X-ray techniques. Our work revealed a prolonged intercalation-extrusion-cation disordering process during phase transformations from the rutile phase to rocksalt phase, which microscopically corresponds to topotactic rearrangement of Fe/Co-O/F octahedra. During this process, the diffusion channels of lithium transformed from 3D to 2D while the corner-sharing octahedron changed to edge-sharing octahedron. DFT calculations indicate that the Co and O cosubstitution of the Fe0.9Co0.1OF cathode can improve its structural stability by stabilizing the thermodynamic semistable phases and reducing the thermodynamic potentials. We anticipate that our study will inspire further explorations on untraditional intercalation systems for secondary battery applications.