Mechanochemical Synthesis of Perovskite Oxyhydrides: Insights from Shear Modulus.

Perovskite oxyhydrides have attracted recent attention due to their intriguing properties such as ionic conductivity and catalysis, but their repertoire is still restricted compared to perovskite oxynitrides and oxyfluorides. Historically, perovskite oxyhydrides have been prepared mostly by topochemical reactions and high-pressure (HP) reactions, while in this study, we employed a mechanochemical (MC) approach, which enables the synthesis of a series of ABO2H-type oxyhydrides, including those with the tolerance factor (t) much smaller than 1 (e.g., SrScO2H with t = 0.936) which cannot be obtained by HP synthesis. The octahedral tilting, often present in perovskite oxides, does not occur, suggesting that the lack of π-symmetry of the H 1s orbital and the large polarization destabilize tilted low-symmetry structures. Interestingly, SrCrO2H (t = 0.997), previously reported with the HP method, was not achieved with the MC method. A comparative analysis revealed a correlation between the feasibility of MC reactions and the (calculated) shear modulus of the starting reagents (binary oxides and hydrides). Notably, this indicator is not exclusive to oxyhydride perovskites but extends to oxide perovskites (SrMO3). This study demonstrates that MC synthesis offers unique opportunities not only to expand the compositional space in oxyhydrides in various structural types but also to provide a guide for the choice of starting materials for the synthesis of other compounds.

Synergy of Two Intermolecular Hydrogen Bonds Promotes Highly Sensitive and Selective Room-Temperature Dimethyl Methylphosphonate Sensing: A Case of rGO-Based Gas Sensors.

The development of room-temperature chemiresistive gas sensors with low limit of detection, high sensitivity, and selectivity for dimethyl methylphosphonate (DMMP) detection remains a challenge. Herein, a synergy of the two intermolecular hydrogen bond-promoted approach was proposed to fabricate a room-temperature DMMP sensor with enhanced performances. As a proof of concept, ternary p-hexafluoroisopropanol phenyl (HFIP) functionalized polypyrrole-reduced graphene oxide hybrids (HFIP-PPy-rGO) were rationally designed. During the sensing process, rGO serves as a conductive carrier, ensuring that the sensors operate at room temperature, and both HFIP and PPy act as adsorption sites for DMMP through hydrogen bonding interactions. As expected, the HFIP-PPy-rGO sensor exhibits high selectivity and sensitivity to DMMP. Besides, the HFIP-PPy-rGO sensor also possesses excellent linear response to DMMP and long-term stability. Experimental results and quartz crystal microbalance measurements prove that the specific recognition of DMMP is realized by forming two intermolecular hydrogen bonds between HFIP and DMMP, as well as PPy and DMMP. Additionally, the introduction of HFIP groups also contributes to adjusting device conductivity, enhancing signal conversion function. To put the DMMP sensor into potential practical application, the obvious sensing response to different DMMP concentrations in soil was confirmed, and a wireless detection system was built to realize real-time monitoring of DMMP concentrations in the surroundings. Overall, this study provides a facile and practical solution for improving the sensing performance of room-temperature sensors based on the hydrogen bond theory.

Pressure-Induced Anion Order-Disorder Transition in Layered Perovskite Sr2LiHOCl2.

While cation order-disorder transitions have been extensively investigated because of their decisive impact on chemical and physical properties, only few anion order-disorder transitions are known. Here, we show that Sr2CuO2Cl2-type layered perovskite Sr2LiHOCl2 exhibits a pressure-induced H-/O2- order-disorder transition. When synthesized at ambient and low pressures (≤2 GPa), Sr2LiHOCl2 is isostructural to orthorhombic Eu2LiHOCl2 (Cmcm) with a H-/O2- order at the equatorial sites. However, applying a higher pressure (5 GPa) during synthesis causes the equatorial anions to be disordered, leading to a tetragonal symmetry (I4/mmm) with a loss of the superstructure. The structural analysis revealed that, in the ambient pressure phase, HLi2Sr4 and OLi2Sr4 octahedra have distinct sizes to stabilize otherwise underbonded oxide ions, which is less important at the higher pressure. Anion-disordered Sr2LiHOBr2 and Ba2LiHOCl2 were also obtained at 5 GPa. Given the abundant layer-type anion order in perovskite-based oxyhydrides (e.g., La2LiHO3), the inclusion of additional anions (e.g., chloride) expands the frontiers of anion ordering patterns and their distribution control with the benefit of improving ionic conduction in solids.

Managing thrombosis of arteriovenous fistula accompanied by aneurysm and single outflow of elbow perforating vein: a case report.

BACKGROUND: We report a case of a patient who suffered thrombosis of a radial artery-cephalic vein fistula accompanied by aneurysm and a single outflow path of the elbow perforating vein. We performed open surgery combined with Fogarty balloon catheter embolectomy, anastomotic reconstruction and forearm median vein transposition. CASE PRESENTATION: The patient presented with an arteriovenous fistula (AVF) after haemodialysis 5 years ago. In the process of dialysis, the fistula vein was punctured, resulting in aneurysm, high pressure and difficult haemostasis after needle extraction. AVF occlusion was observed on April 12, 2022. We performed a combined open surgery. First, a Fogarty balloon catheter was used to remove the thrombus, and the anastomosis was then reconstructed to restore AVF fistula patency. Finally, forearm median vein transposition was used to establish dual outflow. Postoperative haemodialysis was possible. There are various methods for removing the thrombus in AVF. Here, we report a case in which we performed open surgery combined with Fogarty balloon catheter embolectomy, anastomotic reconstruction and forearm median vein transposition to ensure fistula patency. CONCLUSION: We removed a complete reverse 'Z'-shaped thrombus of the elbow perforating vein in a haemodialysis fistula. This report provides an effective strategy to manage a high-pressure fistula with single outflow of the elbow perforating vein.

Microemulsion of Cinnamon Essential Oil Formulated with Tea Polyphenols, Gallic Acid, and Tween 80: Antimicrobial Properties, Stability and Mechanism of Action.

The objective of this article was to combine tea polyphenols, gallic acid, and cinnamon essential oil to construct a natural extract-complex microemulsion system (NMs) with good antibacterial activity, antioxidant activity, and stability, as well as low irritation. NMs were characterized by particle size distribution, electrical conductivity, and light transmittance. The stability, as well as the antimicrobial, antioxidant, irritation, and antimicrobial mechanisms, of NMs were also studied. The results showed that NMs had a significant antimicrobial function against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans and Aspergillus brasiliensis. The minimum inhibitory concentrations were 156 µg/mL, 62.5 µg/mL, 125 µg/mL, 250 µg/mL, and 125 µg/mL, respectively. Through the cell membrane permeability test and growth curve test of bacteria and fungi, we concluded that the NMs' mechanism of action on bacteria and fungi could be interpreted as NMs mainly altering the permeability of cell membranes to inhibit the growth of bacteria and fungi. The results of this study have important implications for utilizing plant extracts as natural preservatives for food and cosmetics.

Formation of PbCl2-type AHF (A = Ca, Sr, Ba) with partial anion order at high pressure.

The high-pressure structures of alkaline earth metal hydride-fluorides (AHFs) (A = Ca, Sr, Ba) were investigated up to 8 GPa. While AHF adopts the fluorite-type structure (Fm3[combining macron]m) at ambient pressure without anion ordering, the PbCl2-type (cotunnite-type) structure (Pnma) is formed by pressurization, with a declining trend of critical pressure as the ionic radius of the A2+ cation increases. In contrast to PbCl2-type LaHO and LaOF whose anions are fully ordered, the H-/F- anions in the high-pressure polymorph of SrHF and BaHF are partially ordered, with a preferential occupation of H- at the square-pyramidal site (vs. tetrahedral site). First-principles calculations partially support the preferential anion occupation and suggest occupation switching at higher pressure. These results provide a strategy for controlling the anion ordering and local structure in mixed-anion compounds.

Surface passivated halide perovskite single-crystal for efficient photoelectrochemical synthesis of dimethoxydihydrofuran.

Halide perovskite single-crystals have recently been widely highlighted to possess high light harvesting capability and superior charge transport behaviour, which further enable their attractive performance in photovoltaics. However, their application in photoelectrochemical cells has not yet been reported. Here, a methylammonium lead bromide MAPbBr3 single-crystal thin film is reported as a photoanode with potential application in photoelectrochemical organic synthesis, 2,5-dimethoxy-2,5-dihydrofuran. Depositing an ultrathin Al2O3 layer is found to effectively passivate perovskite surface defects. Thus, the nearly 5-fold increase in photoelectrochemical performance with the saturated current being increased from 1.2 to 5.5 mA cm-2 is mainly attributed to suppressed trap-assisted recombination for MAPbBr3 single-crystal thin film/Al2O3. In addition, Ti3+-species-rich titanium deposition has been introduced not only as a protective film but also as a catalytic layer to further advance performance and stability. As an encouraging result, the photoelectrochemical performance and stability of MAPbBr3 single-crystal thin film/Al2O3/Ti-based photoanode have been significantly improved for 6 h continuous dimethoxydihydrofuran evolution test with a high Faraday efficiency of 93%.

Hippocampal 7α-Hydroxylated Neurosteroids Are Raised by Training and Bolster Remote Spatial Memory with Increase of the Spine Densities.

Neuroactive steroids, termed neurosteroids, are synthesized locally in the brain and influence biological functions including cognition and behavior. These neurosteroids are synthesized from cholesterol by a series of cytochrome P450 enzymes, among which a member of P450 hydroxylase, cytochrome P450-7b1 (CYP7B1), catalyzes the formation of 7α-hydroxylated neurosteroids, 7α-hydroxypregnenolone (7α-OH-Preg) and 7α-hydroxydehydroepiandrosterone (7α-OH-DHEA). Here we demonstrated the occurrence of these neurosteroids in the mouse hippocampus after spatial-learning tasks. Cyp7b1 deficiency impaired remote spatial memory with recent memory mostly unaffected. The hippocampal dendritic spine densities were reduced in Cyp7b1-deficient mice, and they were no more increased by the training. Furthermore, chronic intracerebroventricular administration of a mixture of 7α-OH-Preg and 7α-OH-DHEA rescued the deteriorated remote memory performance in Cyp7b1-deficient mice. It is concluded that the 7α-hydroxylated neurosteroids are required for long-term maintenance of spatial memory, and we suggest that these neurosteroids may induce synaptic remodeling to maintain the hippocampal function.

Characterization of the Vaginal Microbiome in Women with Infertility and Its Potential Correlation with Hormone Stimulation during In Vitro Fertilization Surgery.

Perturbation of vaginal microbiome of reproductive-age women influences all the phases of a woman's reproductive life. Although studies have shown that dynamic changes in vaginal microbiome can affect pregnancy, its role in secondary infertility (i.e., inability to become pregnant or to carry a pregnancy successfully after previous success in delivering a child) and in vitro fertilization (IVF) remains to be unraveled. To determine the vaginal microbiome in women undergoing in vitro fertilization and embryo transfer (IVF-ET) and investigate its potential correlations with hormone stimulation, we recruited 30 patients with secondary infertility and receiving IVF and 92 matched healthy women and analyzed their vaginal microbiome composition using 16S rRNA gene sequencing. Our results show that women suffering from infertility (infertile women) exhibit a significant decrease in microbiome diversity and richness compared with healthy women during the nonovulation period (follicular phase) (P < 0.01), whereas vaginal microbiome of healthy women reveals dramatic fluctuations during ovulation (P < 0.05). Interestingly, infertility patients show no change of the vaginal microbiome under conditions of gonadotropin-releasing hormone (GnRH) agonist and recombinant human chorionic gonadotropin (r-hCG) induction (P > 0.05). Moreover, our results indicate that infertile women show characteristic variations in vaginal microbiome, such as increased abundance of Atopobium, Aerococcus, and Bifidobacterium and decreased abundance of Lactobacillus and Leuconostoc IMPORTANCE The microbiome had been hypothesized to be involved in the physiology and pathophysiology of assisted reproduction before the first success in IVF, while the data supporting or refuting this hypothesis were less than conclusive. Thanks to sequencing data from the 16S rRNA subunit, we characterized the microbiome in the reproductive tract of infertile women, and we found that changes in the vaginal microbiome are related to female infertility. We also found that the characteristic microbiome bacteria are mainly members of several genera and that the vaginal microbiome of infertile women is not sensitive to hormonal changes during IVF. In conclusion, our report provides data that can be used for discovering the role of the vaginal microbiome in patients suffering from secondary infertility.

Aberrant expression of CD13 and stem cell markers in CD133-induced liver cancer in mice.

PURPOSE: The purpose of the study is to identify the Cancer Stem Cells (CSCs) and to determine their expression profiles in different pathological stages of liver cancer by using multiple markers Methods: In this study, the expression profiles of CD133 and CD13, along with those of stem cell markers Oct4 and SOX2, were analyzed using immunohistochemistry and immunoblotting to clarify the character of CSCs in different stages of liver cancer. RESULTS: CD133 liver cancer cells were injected into mice, and the tissues were processed for histology. The histological data revealed the progression of liver cancer. Immunohistochemical analysis showed the strong expression of CD133 in metastatic cancer. In contrast, the expression of CD13 in both primary and metastatic liver cancer was found to be very strong. Interestingly, the expression levels of Oct4 and SOX2 were found to be upregulated in primary tumors, but, in the metastatic stage, their expression was downregulated. The immunoblot analysis also confirmed the same result. CONCLUSIONS: Our findings demonstrate that tumor-suppressor proteins Oct4 and SOX2 have a prominent expression profile in the primary stage of cancer, but, in the metastatic stage, their expression is downregulated, leading to the failure to prevent metastatic cancer.

lncRNA UCA1 Mediates Resistance to Cisplatin by Regulating the miR-143/FOSL2-Signaling Pathway in Ovarian Cancer.

The aim of this study was to explore the roles of the long noncoding RNA (lncRNA) urothelial carcinoma-associated 1 (UCA1) on cisplatin resistance in ovarian cancer and the underlying mechanisms. We investigated the expression of lncRNAs in 3 paired cisplatin-sensitive and cisplatin-resistant tissues of ovarian cancer by microarray analysis. The qRT-PCR analysis was to investigate the expression pattern of UCA1 in cisplatin-resistant ovarian cancer patient tissues and cell lines. Then we examined the effects of UCA1 on cisplatin resistance in vitro and in vivo. In this study, UCA1 was observed to be upregulated in cisplatin-resistant patient tissues and cell lines. Knockdown of UCA1 inhibited cell proliferation and promoted the cisplatin-induced cell apoptosis in ovarian cancer cells. Then we demonstrated that repressed UCA1 promoted the miR-143 expression and miR-143 could bind to the predicted binding site of UCA1. Furthermore, we found that miR-143 displayed its role via modulating the FOSL2 expression. Importantly, we demonstrated that UCA1 was upregulated in serum exosomes from cisplatin-resistant patients. In summary, our study demonstrated that UCA1 modulates cisplatin resistance through the miR-143/FOSL2 pathway in ovarian cancer.

Cycloartenol exerts anti-proliferative effects on Glioma U87 cells via induction of cell cycle arrest and p38 MAPK-mediated apoptosis.

PURPOSE: Gliomas are destructive malignancies affecting mainly the central nervous system. Gliomas constitute around 50% of all the central nervous system tumors. The purpose of this study was to examine the anticancer activity of cycloartenol against the glioma U87 cells and to investigate the underlying mechanisms. METHODS: MTT and colony formation assay were used to determine the proliferation rate. Acridine orange/ethidium bromide (AO/EB) and annexin V/propidium iodide (PI) were used to determine apoptosis and cell cycle analysis was carried out by western blotting. Cell migration was checked by cell migration assay and immunoblotting was used for checking protein expressions. RESULTS: The results revealed that cycloartenol inhibited the proliferation and the colony formation potential of the glioma U87 cells in a concentration-dependent manner. The antiproliferative effects were found to be due to induction of Sub-G1 cell cycle arrest and triggering of apoptosis. These effects were found to be dose-dependent. Cycloartenol also caused significant alteration in the expression of Bax and Bcl-2. Furthermore, cycloartenol inhibited the migration of glioma cells and suppressed the phosphorylation of the p38 MAP kinase. CONCLUSION: These findings indicate that cycloartenol may prove beneficial in the treatment of glioma and warrants further investigation.

Exposure to Aroclor-1254 impairs spindle assembly during mouse oocyte maturation.

Polychlorinated biphenyls (PCBs), as typical environmental estrogen disruptors, are a structurally-related group of halogenated aromatic hydrocarbons that are composed of 209 isomers and present as a mixture in the environment. PCBs congener with different numbers and positions of chlorine atoms substituted on the biphenyl moiety. Aroclor-1254 is a mixture of more than 60 PCB congeners. Previous studies have provided the evidence that PCBs have severe negative effects on reproductive functions, but the effects of PCBs on spindle assembly during mouse oocyte maturation in vitro have not been reported. In the present study, female ICR mouse immature oocytes were cultured in M2 medium with 1 and 10 µg mL-1 Aroclor-1254 separately in vitro. The percentage of germinal vesicle breakdown (GVBD) and the first polar body extrusion were recorded. The results showed no significant difference in the percentage of GVBD or the first polar body extrusion between control oocytes and Aroclor-1254-treated oocytes. Further studies showed that the normal localization of γ-tubulin and Aurora-A kinase was interfered and α-tubulin assembling into spindle was affected when mouse oocytes were exposed to Aroclor-1254. The length of spindle from 10 µg mL-1 Aroclor-1254-treated oocytes was longer than that from control oocytes, and the spindle area in the Aroclor-1254-treated groups were decreased. Furthermore, the percentage of DNA damage in cumulus cells revealed an increase after exposed to Aroclor-1254. These results will provide the important reference for the prevention of reproductive disorders caused by PCBs. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1652-1662, 2016.