Search

Organic electrochemical transistors (OECTs) are of great interest in low‐power bioelectronics and neuromorphic computing, as they utilize organic mixed ionic‐electronic conductors (OMIECs) to transduce ionic signals into electrical signals. However, the poor environmental stability of OMIEC materials significantly restricts the practical application of OECTs. Therefore, the non‐fused planar naphthalenediimide (NDI)‐dialkoxybithiazole (2Tz) copolymers are fine‐tuned through varying ethylene glycol (EG) side chain lengths from tri(ethylene glycol) to hexa(ethylene glycol) (namely P‐XO, X = 3–6) to achieve OECTs with high‐stability and low threshold voltage. As a result, the NDI‐2Tz copolymers exhibit ambipolarity, rapid response (<10 ms), and ultra‐high n‐type stability. Notably, the P‐6O copolymers display a threshold voltage as low as 0.27 V. They can operate in n‐type mode in an aqueous solution for over 60 h, maintaining an on‐off ratio of over 105. This work sheds light on the design of exceptional n‐type/ambipolar materials for OECTs. It demonstrates the potential of incorporating these ambipolar polymers into water‐operational integrated circuits for long‐term biosensing systems and energy‐efficient brain‐inspired computing. [ABSTRACT FROM AUTHOR]

Aim: The impaired function of tubular mitochondria is critical in diabetic kidney disease (DKD) progression. RUNX3 is down‐regulated in DKD models. We intend to explore the effects of RUNX3 on mitochondrial dysfunction and renal tubule injury in DKD and related mechanisms. Methods: The development of diabetes models involved injecting mice with streptozotocin while treating HK‐2 cells with high glucose (HG). By using immunohistochemical techniques, the renal localizations of RUNX3 were identified. Levels of adenosine triphosphate (ATP), mitochondrial membrane potential, and biochemical index were detected by appropriate kits. Reactive oxygen species (ROS) generation was assessed with dihydroethidium and MitoSOX Red staining. Apoptosis was assessed by flow cytometry and TUNEL. RUNX3 ubiquitination was measured. Results: RUNX3 was mainly present in renal tubules. Overexpressing RUNX3 increased Mfn2, Mfn1, ATP levels, and mitochondrial membrane potential, reduced Drp1 and ROS levels and cell apoptosis, as well as Cyt‐C release into the cytoplasm. RUNX3 overexpression displayed a reduction in urinary albumin to creatinine ratio, Hemoglobin A1c, serum creatinine, and blood urea nitrogen. Overexpressing TLR4 attenuated the inhibitory effect of RUNX3 overexpression on mitochondrial dysfunction and cell apoptosis. HG promoted RUNX3 ubiquitination and SMURF2 expression. RUNX3 knockdown cancelled the inhibitory effect of SMURF2 on mitochondrial dysfunction and cell apoptosis. Conclusion: SMURF2 interference inhibits RUNX3 ubiquitination and TLR4/NF‐κB signalling pathway, thereby alleviating renal tubule injury. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks with well‐organized low‐dimensional architectures provide significant thermodynamic and/or kinetic benefits for diverse applications. We present here the controlled synthesis of a novel class of hierarchical zirconium‐porphyrin frameworks (ZrPHPs) with nanosheet‐assembled hexagonal prism morphology. The crystal growth behaviors and structural evolution of ZrPHPs in an additive‐modulated solvothermal synthesis are examined, showing an "assembly‐hydrolysis‐reassembly" mechanism towards the formation of 2D nanosheets with ordered arrangement. Because of the highly‐accessible active sites harvesting broadband photons, ZrPHPs serve as adaptable photocatalysts to regulate macromolecular synthesis under full‐range visible light and natural sunlight. An initiator‐free, oxygen‐tolerant photopolymerization system is established, following a distinctive mechanism involving direct photo‐induced electron transfer to dormant species and hole‐mediated reversible deactivation. Specifically, ZrPHPs provide a surface‐confined effect towards the propagating chains which inhibits their recombination termination, enabling the highly‐efficient synthesis of ultrahigh molecular weight polymers (Mn >1,500,000) with relatively low dispersity (Đ≈1.5). [ABSTRACT FROM AUTHOR]

Hybrid hydrogen‐bonded (H‐bonded) frameworks built from charged components or metallotectons offer diverse guest‐framework interactions for target‐specific separations. We present here a study to systematically explore the coordination chemistry of monovalent halide anions, i.e. F−, Cl−, Br−, and I−, with the aim to develop hybrid H‐bond synthons that enable the controllable construction of microporous H‐bonded frameworks exhibiting fine‐tunable surface polarity within the adaptive cavities for realistic xenon/krypton (Xe/Kr) separation. The spherical halide anions, especially Cl−, Br−, and I−, are found to readily participate in the charge‐assisted H‐bonding assembly with well‐defined coordination behaviors, resulting in robust frameworks bearing open halide anions within the distinctive 1D pore channels. The activated frameworks show preferential binding towards Xe (IAST Xe/Kr selectivity ca. 10.5) because of the enhanced polarizability and the pore confinement effect. Specifically, dynamic column Xe/Kr separation with a record‐high separation factor (SF=7.0) among H‐bonded frameworks was achieved, facilitating an efficient Xe/Kr separation in dilute, CO2‐containing gas streams exactly mimicking the off‐gas of spent nuclear fuel (SNF) reprocessing. [ABSTRACT FROM AUTHOR]

Background: Studies evaluating outcomes of COVID‐19 patients with candidemia are limited and have only evaluated a single timepoint during the pandemic. Objectives: To compare the prevalence and outcomes associated with candidemia in patients based on severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) status and through the various pandemic waves (1 March 2020–5 March 2022). Patients/Methods: Multicentre, retrospective cohort analysis of data from 248 US medical facilities using the BD Insights Research Database (Becton, Dickinson and Company, Franklin Lakes, New Jersey, USA). Eligible patients were adults aged ≥18 years who were hospitalised for >1 day, had a SARS‐CoV‐2 test and a positive blood culture for Candida spp. Results: During the study time frame, there were 2,402,879 hospital admissions; 234,903 (9.7%) and 2,167,976 (90.3%) patients were SARS‐CoV‐2 positive and negative, respectively. A significantly higher rate of candidemia/1000 admissions was observed in SARS‐CoV‐2‐positive patients compared to SARS‐CoV‐2‐negative patients (3.18 vs. 0.99; p <.001). The highest candidemia rate for SARS‐CoV‐2‐positive patients was observed during the Alpha SARS‐CoV‐2 wave (June 2020–August 2020) with the lowest candidemia rate during the Omicron wave. Hospital mortality was significantly higher in SARS‐CoV‐2‐positive patients compared to SARS‐CoV‐2‐negative patients with candidemia (59.6% vs. 30.8%; p <.001). When evaluating the mortality rate through the various pandemic waves, the rate for the overall population did not change. Conclusions: Our study indicates high morbidity and mortality for hospitalised patients with COVID‐19 and candidemia which was consistent throughout the pandemic. Patients with COVID‐19 are at an increased risk for candidemia; importantly, the magnitude of which may differ based on the circulating variant. [ABSTRACT FROM AUTHOR]

Background: Renal tubular injury is the main feature of diabetic nephropathy (DN). We intend to investigate the function and related mechanisms of lncRNA SOX2 overlapping transcript (SOX2OT) in high glucose (HG)‐induced oxidative stress and apoptosis of renal tubular epithelial cells (RTECs). Methods: To construct diabetes models, the human kidney‐2 (HK‐2) cells were treated with HG (30 mM), and mice were injected with streptozotocin. The levels of intracellular and mitochondrial reactive oxygen species (ROS) were assessed by dihydroethidium staining and MitoSox staining. The cell apoptosis was assessed by flow cytometry and TUNEL staining. Levels of serum creatinine, blood urea nitrogen (BUN), Urinary ACR, and oxidative stress marker 8‐hydroxy‐2′‐deoxyguanosine (8‐OHdG) were detected by relevant kits. In addition, fluorescence in situ hybridization staining, RNA‐pull down, RNA immunoprecipitation (RIP), co‐immunoprecipitation (co‐IP), dual‐luciferase reporter gene assay and chromatin immunoprecipitation (ChIP) were also executed. Results: Levels of SOX2OT and silent information regulator 1 (SIRT1) were down‐regulated in HG‐cultured HK‐2 cells. Overexpressing SOX2OT reduced intracellular and mitochondrial ROS levels and cell apoptosis in vitro. Moreover, SOX2OT overexpression also reduced serum creatinine, BUN, urinary ACR, 8‐OHdG, renal tubular injury markers KIM1 and NGAL, ROS levels, and cell apoptosis in vivo. In addition, SOX2OT promoted SIRT1 expression by suppressing its ubiquitination. Besides, interference with SIRT1 reversed the inhibitory effect of SOX2OT overexpression on HG‐induced oxidative stress and apoptosis. Forkhead box A2 (Foxa2) levels were up‐regulated in HG‐cultured HK‐2 cells. Foxa2 could bind to the SOX2OT promoter and suppress its expression. Furthermore, interfering with SOX2OT reversed the inhibitory effect of Foxa2 interference on HG‐induced oxidative stress and apoptosis. Conclusion: Foxa2‐mediated SOX2OT up‐regulation reduced oxidative stress and apoptosis of RTECs by promoting SIRT1 expression, thus alleviating the progression of DN. Summary at a Glance: Renal tubule injury plays a major role in the progression of diabetic nephropathy (DN). This study explored the pathogenesis of DN from the perspective of renal tubular epithelial cell injury mediated by oxidative stress under the effect of high glucose (HG). Authors revealed that lncRNA SOX2OT was lowly expressed in renal tubular epithelial cells; Foxa2 was highly expressed in the DN mouse model and HG‐induced renal tubular epithelial cells; lncRNA SOX2OT promoted SIRT1 expression by suppressing its ubiquitination; Foxa2 could bind to the lncRNA SOX2OT promoter and suppress its expression; overexpression of lncRNA SOX2OT inhibits oxidative stress and apoptosis by up‐regulating the SIRT1 levels and improves renal function. [ABSTRACT FROM AUTHOR]

Organic electrochemical transistors (OECTs) have emerged as building blocks for low power circuits, biosensors, and neuromorphic computing. While p‐type polymer materials for OECTs are well developed, the choice of high‐performance n‐type polymers is limited, despite being essential for cation and metabolite biosensors, and crucial for constructing complementary circuits. N‐type conjugated polymers that have efficient ion‐to‐electron transduction are highly desired for electrochemical applications. In this contribution, three non‐fused, planar naphthalenediimide (NDI)‐dialkoxybithiazole (2Tz) copolymers, which systematically increase the amount of polar tri(ethylene glycol) (TEG) side chains: PNDI2OD‐2Tz (0 TEG), PNDIODTEG‐2Tz (1 TEG), PNDI2TEG‐2Tz (2 TEG), are reported. It is demonstrated that the OECT performance increases with the number of TEG side chains resulting from the progressively higher hydrophilicity and larger electron affinities. Benefiting from the high electron mobility, excellent ion conduction capability, efficient ion‐to‐electron transduction, and low‐lying lowest unoccupied molecular orbital energy level, the 2 TEG polymer achieves close to 105 on‐off ratio, fast switching, 1000 stable operation cycles in aqueous electrolyte, and has a long shelf life. Moreover, the higher number TEG chain substituted polymer exhibits good conductance state retention over two orders of magnitudes in electrochemical resistive random‐access memory devices, highlighting its potential for neuromorphic computing. [ABSTRACT FROM AUTHOR]

A binary solvent synthetic strategy is proposed for the construction of C2‐symmetric molecule‐based hydrogen‐bonded organic frameworks (HOFs) with permanent ultra‐micropores and surface polarization derived from tunable coplanar open oxygen atoms. The activated HOFs BTBA‐1 a and PTBA‐1 a show highly selective separation of CO2/N2 with a record high ideal adsorbed solution theory (IAST) selectivity >2000 under ambient temperature and pressure. [ABSTRACT FROM AUTHOR]

BACKGROUND: Codonopsis pilosula and Codonopsis tangshen are plants widely used in traditional Chinese medicine. Two pectic polysaccharides from the roots of C. pilosula and C. tangshen named as CPP‐1 and CTP‐1 were obtained by boiling water extraction and column chromatography. RESULTS: The core structures of both CPP‐1 and CTP‐1 comprise the long homogalacturonan region (HG) as the backbone and the rhamnogalacturonan I (RG‐I) region as the side chains. CPP‐1 has methyl esterified galacturonic acid units and a slightly lower molecular weight than CTP‐1. Biological testing suggested that CPP‐1 and CTP‐1 can protect IPEC‐J2 cells against the H2O2‐induced oxidative stress by up‐regulating nuclear factor‐erythroid 2‐related factor 2 and related genes in IPEC‐J2 cells. The different antioxidative activities of polysaccharides from different source of C. pilosula may be result of differences in their structures. CONCLUSION: All of the results indicated that pectic polysaccharides CPP‐1 and CTP‐1 from different species of C. pilosula roots could be used as a potential natural antioxidant source. These findings will be valuable for further studies and new applications of pectin‐containing health products. © 2021 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Construction of segregated structure is an effective way of preparing highly conductive composite. Here, we report an environmentally friendly method to prepare highly conductive linear low‐density polyethylene/graphene nanoplatelets composite with segregated structure (s‐LLDPE/GN) and low GN content. Firstly, GN coated LLDPE granules are prepared through aqueous dispersing and gradually drying. Then, the s‐LLDPE/GN composites are obtained by melting and self‐leveling without extra pressure. This method not only favors the forming of GN segregated network, but also allows certain fusing of the polymer at the interfaces that contribute to good mechanical strength of the composite. The electrical conductivity of the composite increases to 4.5 S/m when the GN content is 1.0 wt%. The composite with 0.5 wt% GN shows 10−1 S/m electrical conductivity, and retains 82% of the tensile strength of pure LLDPE. The facile and green process in this method can be applied in many other polymer composites and show high potential for industrial application. [ABSTRACT FROM AUTHOR]

Background: Patients with schizophrenia have an increased prevalence of type 2 diabetes mellitus that has shown a significant association with the rs7754840 polymorphism in the gene encoding the cyclin‐dependent kinase 5 (CDK5) regulatory subunit‐associated protein 1‐like 1 (CDKAL1). Objective: To examine whether this polymorphism was involved in the susceptibility in first‐episode drug‐naive schizophrenic patients (FDSP), and further influenced their clinical symptoms. Methods: This polymorphism was genotyped in 239 FDSP and 368 healthy controls. The clinical symptoms in FDSP were assessed using the Positive and Negative Syndrome Scale (PANSS) five‐factor models. Results: There was no significant difference in the allelic and genotypic frequencies of this polymorphism between two groups (both p > 0.05) after adjusting for covariates. However, the PANSS depressive score significantly differed by genotype in FDSP after adjusting for covariates (F = 5.25, p = 0.006). This significant difference also persisted after Bonferroni correction (p < 0.05). FDSP with C/C genotype had significantly higher PANSS depressive score than those with C/G genotype (p = 0.007) and those with G/G genotype (p = 0.005). Moreover, further stepwise multivariate regression analysis showed the significant association between the rs7754840 polymorphism and PANSS depressive score in FDSP (β = −1.07, t = −2.75, p = 0.007). Conclusions: Our findings demonstrated that although the CDKAL1 rs7754840 polymorphism did not contribute to the susceptibility to FDSP, it might be implicated in depressive symptoms in this patient group. [ABSTRACT FROM AUTHOR]

Aim: Proper arteriovenous fistula (AVF) management is crucial to avoid AVF complications and prolong its useful life for maintenance haemodialysis (MHD). Design: Retrospective cohort study. Methods: Patients on MHD who underwent AVF surgery at the Wuhan Third Hospital between January 2018 and July 2018. Results: A total of 144 patients were included, with 56 in the integrated group and 88 in the routine group. There were no differences between the two groups in terms of sex (p =.61), age (p =.62) and type of primary kidney disease (p >.99). At 1 year, the integrated group had significantly fewer fistula‐related complications than the routine group (3.6% versus. 23.9%, p <.001). AVF functional scores were lower in the integrated group compared with the routine group (0.1 ± 0.5 versus. 0.8 ± 0.8, p <.001). The pain scores were lower in the integrated group than in the routine group (1.2 ± 0.4 versus. 1.8 ± 0.9, p <.001). [ABSTRACT FROM AUTHOR]

Peripheral nerve injuries are one of the most common types of traumatic damage to the nervous system. Treatment of peripheral nerve injuries aims to promote axon regrowth by imitating and improving the microenvironment for sciatic nerve regeneration. In this study, regeneration efficiency and behavior of peripheral nerves are compared under three treatment strategies: 1) transplantation of Schwann cell progenitors induced from purified neural crest stem cells; 2) implantation of a multiscale scaffold based on high‐resolution 3D printing; and 3) implantation of this bionic scaffold loading Schwann cell progenitors. The results of structural, electrophysiological, and behavioral tests demonstrate that the three treatment strategies result in different degrees of regeneration. The purified neural crest stem cells differentiate into functional Schwann cells and promote axon regeneration. The multifunctional 3D printed scaffold promotes oriented growth and myelination, and the myelinated nerve regrows with increased density and without visible scaffolds after six months. For the regeneration, scaffold treatment produces better performance than cell graft alone. Finally, it is shown that implantation of multiscale scaffolds preloaded with neural crest stem cell derived Schwann cell progenitors is the best strategy to promote peripheral nerve regeneration with improved anatomy and function among the three different strategies. [ABSTRACT FROM AUTHOR]

Graphene oxide (GO) membranes with unique nanolayer structure have demonstrated excellent separation capability based on their size‐selective effect, but there are few reports on achieving ion–ion separation, because it is difficult to inhibit the swelling effect of GO nano sheets as well as to precisely control the interlayer spacing d to a specific value between the sizes of different metal ions. Here, selective separation of uranium from acidic radioactive waste containing multication is achieved through a precise dual‐adjustment strategy on d. It is found that GO swelling is greatly restricted in highly acidic solution due to protonation effect. Then the interlayer spacing is further precisely reduced to below the diameter of uranyl ion by increasing the oxidation degree of GO. Sieving uranyl ions from other nuclide ions is successfully realized in pH =3–3 mol L−1 nitric acid solutions. [ABSTRACT FROM AUTHOR]

BACKGROUND: Codonopsis pilosula and C. tangshen are both plants widely used in traditional Chinese medicine. Polysaccharides, which are their primary active components, are thought to be important in their extensive use. In this study, two neutral polysaccharide fractions of C. pilosula (CPPN) and C. tangshen (CTPN) were obtained by fractionation on a DEAE–Sepharose column and characterized. RESULTS: It was confirmed that the neutral polymers CPPN and CTPN were β‐(2,1)‐linked inulin‐type fructans with non‐reducing terminal glucose, and degree of polymerization (DP) of 19.6 and 25.2, respectively. The antioxidant and prebiotic activities in vitro were assayed based on IPEC‐J2 cell lines and five strains of Lactobacillus. Results indicated that the effects of CPPN and CTPN were increased antioxidant defense in intestinal epithelial cells through enhanced cell viability, improved expression of total antioxidant capacity, glutathione peroxidase, superoxide dismutase and catalase, and reduced levels of malondialdehyde and lactic dehydrogenase. The prebiotic activity of CPPN and CTPN was demonstrated by the promoting effect on Lactobacillus proliferation in vitro. The different biological activities obtained between the two fractions are probably due to the different DP and thus molecular weights of CPPN and CTPN. CONCLUSION: The inulin fractions from C. pilosula and C. tangshen were natural sources of potential intestinal antioxidants as well as prebiotics, which will be valuable in further studies and new applications of inulin‐containing health products. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Cancer metastasis is a major cause of death among women afflicted with breast cancer (BC) and understanding the molecular processes involved is a major focus in BC research. Circular RNAs (circRNAs) have emerged as genomic regulatory molecules in carcinogenesis and metastasis; however, their role in BC is unclear. We characterized a novel circRNA, hsa_circ_0000515, in context of BC. We collected 340 cancerous tissues surgically resected from BC patients and found hsa_circ_0000515 was upregulated in BC tissues and associated with poor prognosis of BC. Silencing of hsa_circ_0000515 impaired cell cycle progression, cell proliferation, and invasion, attenuated inflammatory response, and reduced the proangiogenetic potential of BC cells. RNA pull‐down and dual‐luciferase reporter gene assays showed that hsa_circ_0000515 binds miR‐296‐5p, preventing it from repressing CXCL10 expression. We also observed that miR‐296‐5p inhibition or CXCL10 overexpression promoted cell cycle progression, restored proliferative, invasive and proangiogenetic abilities, and increased inflammatory response in MCF‐7 cells in the absence of hsa_circ_0000515. In vivo analyses showed that partial loss of hsa_circ_0000515 reduced the tumor growth of MCF‐7 cells in nude mice. The key findings from this study revealed that targeting hsa_circ_0000515 might be an effective strategy to combat BC. [ABSTRACT FROM AUTHOR]

This study describes the modulation of tunneling probabilities in molecular junctions by switching one of two parallel intramolecular pathways. A linearly conjugated molecular wire provides a rigid framework that allows a second, cross‐conjugated pathway to be effectively switched on and off by protonation, affecting the total conductance of the junction. This approach works because a traversing electron interacts with the entire quantum‐mechanical circuit simultaneously; Kirchhoff's rules do not apply. We confirm this concept by comparing the conductances of a series of compounds with single or parallel pathways in large‐area junctions using EGaIn contacts and single‐molecule break junctions using gold contacts. We affect switching selectively in one of two parallel pathways by converting a cross‐conjugated carbonyl carbon into a trivalent carbocation, which replaces destructive quantum interference with a symmetrical resonance, causing an increase in transmission in the bias window. [ABSTRACT FROM AUTHOR]

The article titled "Innenrücktitelbild: Nanosheet-Assembled Zirconium-Porphyrin Frameworks Enabling Surface-Confined, Initiator-Free Photosynthesis of Ultrahigh Molecular Weight Polymers" discusses the development of hierarchical metal-organic frameworks with low-dimensional architectures. The researchers, Yiyun Geng, Gang Ye, and others, have created nanosheet-assembled Zr-porphyrin frameworks that have the ability to harvest a broad range of photons and enhance photocatalytic activity. These frameworks enable the synthesis of ultrahigh molecular weight polymers through an initiator-free, visible-light-regulated radical polymerization process. The resulting polymers have a molecular weight greater than 1,500,000. [Extracted from the article]

The article titled "Inside Back Cover: Nanosheet-Assembled Zirconium-Porphyrin Frameworks Enabling Surface-Confined, Initiator-Free Photosynthesis of Ultrahigh Molecular Weight Polymers" discusses the development of hierarchical metal-organic frameworks with low-dimensional architectures. These frameworks have significant thermodynamic or kinetic benefits and are capable of broadband photon harvesting and enhanced photocatalytic ability. The researchers demonstrate the establishment of an initiator-free, visible-light-regulated radical polymerization process using these frameworks, resulting in the synthesis of ultrahigh molecular weight polymers with a molecular weight greater than 1,500,000. The authors of the article are Yiyun Geng, Gang Ye, and others. [Extracted from the article]

The photophysical process of localized surface plasmon resonance (LSPR) is, for the first time, exploited for broadband photon harvesting in photo‐regulated controlled/living radical polymerization. Efficient macromolecular synthesis was achieved under illumination with light wavelengths extending from the visible to the near‐infrared regions. Plasmonic Ag nanostructures were in situ generated on Ag3PO4 photocatalysts in a reversible addition‐fragmentation chain transfer (RAFT) system, thereby promoting polymerization of various monomers following a LSPR‐mediated electron transfer mechanism. Owing to the LSPR‐enhanced broadband photon harvesting, high monomer conversion (>99 %) was achieved under natural sunlight within 0.8 h. The deep penetration of NIR light enabled successful polymerization with reaction vessels screened by opaque barriers. Moreover, by trapping active oxygen species generated in the photocatalytic process, polymerization could be implemented without pre‐deoxygenation. [ABSTRACT FROM AUTHOR]

To understand the non-breakdown phenomenon during the accelerating electrical tree ageing in cross-linked polyethylene (XLPE) cable insulation, the non-breakdown mechanism of electrical tree is investigated in this study. The needle electrodes were inserted into the cable insulation samples to accelerate electrical tree ageing. The electrical trees which were not broken down had a larger expansion range and branch density. Referring to the actual cable slice for the internal structure of the sample, the electrical tree model with different number of tree channels was built. The correspondence between electric distortion and the number of tree channels was discussed. According to the calculation of the electric field distribution by the finite element method, the results showed that the electric field strength at the tip of electrical tree was reduced when the number of channels was increased. Compared with the single electrical tree channel, when the insulation was completely carbonised in the electrical tree region the electric field strength at the tip of electrical tree was reduced by 20.8%. The electric field shielding which was formed by the tips of electric trees could reduce the electric field strength at the tip of the tree and it could result in the formation of the non-breakdown electric tree. [ABSTRACT FROM AUTHOR]

Abstract: A key challenge of photoregulated living radical polymerization is developing efficient and robust photocatalysts. Now carbon dots (CDs) have been exploited for the first time as metal‐free photocatalysts for visible‐light‐regulated reversible addition–fragmentation chain‐transfer (RAFT) polymerization. Screening of diverse heteroatom‐doped CDs suggested that the P‐ and S‐doped CDs were effective photocatalysts for RAFT polymerization under mild visible light following a photoinduced electron transfer (PET) involved oxidative quenching mechanism. PET‐RAFT polymerization of various monomers with temporal control, narrow dispersity (Đ≈1.04), and chain‐end fidelity was achieved. Besides, it was demonstrated that the CD‐catalyzed PET‐RAFT polymerization was effectively performed under natural solar irradiation. [ABSTRACT FROM AUTHOR]

The rapid degradation of organic photovoltaic (OPV) devices compared to conventional inorganic solar cells is one of the critical issues that have to be solved in order to make OPV a competitive commercial technology. The understanding of the fundamental mechanisms that reduce the power con- version efficiency (PCE) over time is beneficial for the design of new materials with enhanced stability. This paper focuses on bulk heterojunction organic solar cells based on thieno [3,4-b] thiophene-alt-benzodithiophene (PTB7) mixed with [6,6]-phenyl-C71-butyric acid methyl esther ([70]PCBM). In spite of being promising in terms of PCE, devices based on this blend are unstable and have a short lifetime. When exposed to light in inert atmosphere, the PCE drops by 15% in less than 1 h and by 35% in 8 h; this degradation is induced by the ultraviolet (UV) part of the spectrum. This paper analyzes the effect induced by UV light on the transport of charges in PTB7:[70]PCBM. Contrary to expectations, the electron transport shows evidence of trapping, while the transport of holes appears unaffected. Furthermore, it is proven that the loss of PCE is due to a reaction between PTB7 and [70]PCBM, while the intrinsic instability of the polymer plays a marginal role. [ABSTRACT FROM AUTHOR]

Key points Despite the clinical importance of pre-emptive analgesia, the mechanisms by which it attenuates pain associated with central sensitization are poorly understood., We find that fentanyl and the α2-adrenoceptor agonist dexmedetomidine (Dex) differ significantly in their modulatory actions on noxious mechanical and noxious heat-evoked nociception in vivo., Unlike fentanyl, Dex modified descending control of nociception by decreasing the threshold for descending inhibition and/or increasing the threshold for descending facilitation., Dex exhibited after-actions on activities of thalamus in prolongation of noxious heat-evoked paw withdrawal latency that persisted for at least 7 days., This study provides insight into the organization of thalamic modulation in pre-emptive analgesia., Abstract We investigated and compared the antinociceptive effects of intraperitoneal administration of fentanyl (2-60 μg kg−1) and dexmedetomidine (Dex, 1-10 μg kg−1; a highly selective α2-adrenoceptor agonist) in the regulation of nociception assessed by measuring noxious paw withdrawal reflexes in rats. Fentanyl elevated noxious mechanical paw withdrawal threshold and prolonged paw withdrawal heat latency within 1-1.5 h ( P < 0.05). Dex failed to affect the mechanical paw withdrawal threshold, yet significantly prolonged the paw withdrawal heat latency in a bi-phasic manner; a short transient 1-1.5 h period followed by a second, slowly developing increase in latency that persisted for at least 7 days ( P < 0.05). Lesion of the dorsolateral funiculus (DLF) did not influence fentanyl-induced antinociceptive effects, indicating peripheral and spinal antinociceptive mechanisms. By contrast, the Dex-induced second, but not the first, phase of the prolonged paw withdrawal heat latency was significantly blocked by the lesion of either DLF or thalamic ventromedial (VM) nuclei, and was attenuated by intracerebral administration of either atipamezole (α2-adrenoceptor antagonist) or WAY-100635 (5-HT1A receptor antagonist) into the VM nuclei ( P < 0.05). Upon intramuscular 5.8% saline-induced muscle nociception, pre-emptive injection of fentanyl enhanced mechanical hyperalgesia and blocked heat hypoalgesia, whereas Dex significantly prevented the occurrence of mechanical hyperalgesia and enhanced heat hypoalgesia. It is suggested that Dex, but not fentanyl, significantly enhances descending inhibition and/or decreases descending facilitation to modulate pain and nociception. The present study provides novel insight into thalamus-mediated mechanisms in pre-emptive analgesia. [ABSTRACT FROM AUTHOR]

Decellularization techniques have been widely used as an alternative strategy to produce matrices for organ reconstruction. This study investigated the impact of a detergent-enzymatic decellularization protocol on the extracellular matrix integrity, mechanical properties, and biocompatibility of decellularized tracheal matrices from rabbits. The tracheas of New Zealand white rabbits were decellularized using a modified detergent-enzymatic method (DEM). Antigenicity, cellularity, glycosaminoglycan content, DNA content, histoarchitecture, and mechanical properties were monitored during processing. The surface ultrastructure of the matrix was examined by scanning electron microscopy (SEM). Bioengineered and control tracheas were then implanted in major histocompatibility complex-unmatched rats (xenograft) heterotopically for 7, 15, and 30 days. Structural and functional analysis was performed after transplantation. The results showed that seven cycles of decellularization removed most of the cells and eliminated antigenicity. Histological and molecular biology analysis demonstrated that most of the cellular components and nuclear material were removed. SEM analysis revealed that the decellularized matrices retained the hierarchical structure of the native trachea, and biomechanical tests showed that decellularization did not significantly influence the mechanical properties. Seven, 15 and 30 days after implantation, decreased ( p < 0.01) inflammatory reactions were observed in the xenograft models for decellularized matrices compared with control tracheas. No increases in IgM or IgG content were observed in rats that received bioengineered tracheas. In conclusion, this work suggests that seven cycles of the DEM generates a bioengineered rabbit tracheal matrix that is structurally and mechanically similar to native trachea. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 103A: 1509-1519, 2015. [ABSTRACT FROM AUTHOR]

A dynamic covalent bond is one of the ideal linkages for the construction of large and robust organic architectures. In the present article, we show how organic templates can efficiently transform a complex dynamic imine library into a dynamic imine macrocycle. Not only is the constitution well controlled, but also the syn/ anti host configuration is efficiently selected and even the orientation of the guest in the asymmetric cavity of the host can be well aligned. This is attributed to the delicate balance and the cooperation of multiple noncovalent interactions between the hosts and the guests. Through sequential additions of three guests in appropriate amounts, controlled structural reconfiguration of dynamic covalent architectures has been achieved for the first time. [ABSTRACT FROM AUTHOR]

It has been reported that the threshold to activate 'silent' or inactive descending facilitation of nociception is lower than that of descending inhibition. Thus, the development of pain therapy to effectively drive descending inhibition alone, without the confounding influences of facilitation is a challenge. To address this issue we investigated the effects of intramuscular stimulation with a heating-needle on spinal nociception, assessed by measuring nociceptive paw withdrawal reflex in rats. Additionally, involvement of the thalamic 'nociceptive discriminators' (thalamicmediodorsal (MD) and ventromedial (VM) nuclei), and opioid-mediatedmechanisms were further explored. Descending facilitation and inhibition were elicited by 46°C noxious heating-needle stimulation, and were regulated by thalamic MD and VM nuclei, respectively. In contrast, innocuous heating-needle stimulation at a temperature of 43°C elicited descending inhibition modulated by the thalamic VM nucleus alone. Microinjection of μ/δ/κ-opioid receptor antagonists ß-funaltrexamine hydrochloride/naltrindole/nor-binaltorphimine, into the VM nucleus attenuated the 46°C intramuscular heating-needle stimulation-evoked descending inhibition, whereas treatment of the MD nucleus with ß-funaltrexamine hydrochloride significantly decreased the descending facilitation. By contrast, descending inhibition evoked by 43°C heating-needle stimulation was only depressed by naltrindole, as opposed to μ- and κ-opioid receptor antagonists, which failed to influence descending inhibition. The present study reveals distinct roles of μ-opioid receptors in the function of thalamic MD and VM nuclei, which exert facilitatory and inhibitory actions on nociception. Furthermore, innocuous, but not noxious, intramuscular heating-needle stimulation targeting δ-opioid receptors is suggested to be a promising avenue for the effective inhibition of pain. [ABSTRACT FROM AUTHOR]

Two electron-deficient tetracyclic monomers, 6,9-dibromo-7,8-bis(octyloxy)-11H-indeno[2,1-b] quinoxalin-11-one ( M1) and 1,3-bis(5′-bromo-4′-hexylthiophen-2-yl)-9H-indeno[1,2-b]thieno[3,4-e]pyrazin-9-one ( M2), are synthesized through condensation of ninhydrin with aromatic diamines in good yields. Copolymerization of M1 with thiophene (Th) and dithieno[3,2-b:2′,3′-d]silole (DTS), and M2 with DTS affords three new D-A conjugated copolymers, P1- P3, respectively. The optical, electrochemical, and photovoltaic properties of P1-P3 are investigated. P3 exhibits a broad absorption (300-1100 nm) and a low bandgap of 1.24 eV. Solar cells based on P3/[6,6]-phenyl C71 butyric acid methyl ester (PC71BM) blends afford a power conversion efficiency of 1.93% and a very broad spectral response (300-1020 nm). [ABSTRACT FROM AUTHOR]

A novel kind of macrocyclic-host-functionalized periodic mesoporous organosilica (PMO) with excellent and reversible recognition of PbII was developed. The macrocyclic host molecule cis-dicyclohexano[18]crown-6, with strong affinity to PbII, was carefully modified as a bridged precursor to build the PMO material. To break down the limit of the degree for PMOs incorporated with large-sized moieties, a site-selective post-functionalization method was proposed to further decorate the external surface of the PMO material. The selective recognition ability of the upgraded PMO material towards PbII was remarkably enhanced without destroying the mesoporous ordering. Solid-state 13C and 29Si NMR spectroscopy, (XPS), XRD, TEM, and nitrogen adsorption-desorption isotherm measurements were utilized for a full characterization of the structure, micromorphology, and surface properties. Reversible binding of PbII was realized in the binding-elution cycle experiments. The mechanism of the supramolecular interaction between the macrocyclic host and metal ion was discussed. The synthetic strategy can be considered a general way to optimize the properties of PMOs as binding materials for practical use while preserving the mesostructure. [ABSTRACT FROM AUTHOR]

Ischemia and subsequent reperfusion (I/R) damage kidney tubular cells and consequently impair renal function. Rabbit bone marrow mesenchymal stem cells (BM-MSCs) expressing human bone morphogenic protein-7 (hBMP-7) regenerated tubular cells and improved renal function in a kidney I/R model. Rabbits were injected immediately after I/R with one of the following: (i) hBMP-7-transduced BM-MSCs (BM-MSCshBMP-7); (ii) enhanced green fluorescent protein-transduced BM-MSCs (BM-MSCsEGFP); or (iii) PBS. The activity of superoxide dismutase (SOD) was higher, and the amount of malondialdehyde (MDA) was lower in the BM-MSCshBMP-7 group than in the BM-MSCsEGFP group. Both the BM-MSCshBMP-7 group and the BM-MSCsEGFP group had higher SOD activity and lower amounts of MDA than the PBS group. Bcl-2- and Bcl-2-associated X protein levels, and other variables, indicated the regeneration of the kidney in both experimental groups. However, the BM-MSCs hBMP-7 group showed higher activity than the BM-MSCsEGFP group, indicating that the combined strategy of BM-MSC transplantation with hBMP-7 gene therapy could be a useful approach for the treatment of renal IRI. [ABSTRACT FROM AUTHOR]

Background: In this prospective, randomized, double-blind, controlled trial, our primary objective was to assess the effect of a 3 : 1 mixture of propofol and thiopental in reducing pain on injection in children. Our hypothesis was that a 3 : 1 mixture of propofol and thiopental (treatment) would reduce the incidence of pain on injection to 20% compared to the expected incidence of 40% in the control group of an 11 : 1 mixture of propofol and 2% lidocaine. Methods: Study subjects were patients 12–17 years old who were scheduled to undergo surgery and general anesthesia. Pain was assessed by a single-blinded observer present in the operating room. The major statistical method used in the analysis was multiple logistic regression. Results: Among the 164 children analyzed, 96 patients (58.5%) were male. The average age was 14.3 (sd = 1.65). The incidence of pain in the control group was 32.1% (26/81), compared to 25.3% (21/83) in the treatment group. The logistic regression analysis showed that there was not sufficient evidence that the treatment group was better than control group in reducing pain ( P = 0.24). There were no significant differences in postoperative recovery time, nausea, vomiting, or blood pressure between the two groups (all P values >0.10). Conclusion: There was not sufficient evidence to show that a 3 : 1 mixture of propofol and thiopental was better than an 11 : 1 volume admixture of propofol and lidocaine in reducing the incidence of pain on injection to 20%. [ABSTRACT FROM AUTHOR]

A Novel Cryoballoon Technique. Introduction: The study was designed to evaluate the feasibility and efficacy of a simplified cryoballoon technique in which a microcircular catheter was introduced into the central lumen of a cryoballoon catheter for the purpose of recording pulmonary vein (PV) potentials during ablation procedures and without interchanging catheters. Methods and Results: A total of 23 consecutive patients with paroxysmal atrial fibrillation (AF) were enrolled. A single transseptal puncture was made and a cryoballoon catheter was inserted into the left atrium. A 6-pole mapping catheter with a 0.035-inch shaft diameter was introduced into the PV through the central lumen of the cryoballoon catheter. In addition to the function as a recording device, the mapping catheter was also used as a “guide-wire” during the procedure. A total of 84 PVs (84/92, 91.3%) were completely isolated using this novel cryoballoon technique. In 43 of the 84 veins (51.2%), isolation was observed in real time during the cryoablation; in the remaining 41 veins (48.8%), isolation was confirmed immediately post ablation attempt with the mapping catheter. Procedure time was 152.7 ± 54.9 minutes, and fluoroscopy time was 33.2 ± 17.3 minutes. At follow-up (7.4 months, range 2–18 months), 17 (73.9%) patients were free from AF. There was 1 occurrence of phrenic nerve palsy during ablation of a right superior PV, which fully resolved after 1 month. Conclusion: The use of a cryoballoon catheter equipped with a 6-pole micromapping catheter inserted through its central lumen for the purpose of mapping and ablation during PV isolation procedures is both feasible and effective. (J Cardiovasc Electrophysiol, Vol. 21, pp. 626-631, June 2010) [ABSTRACT FROM AUTHOR]

Background: Three-dimensional (3D) image of left atrium (LA) can greatly facilitate ablation of atrial fibrillation (AF). Reconstructing method using computed tomography (CT) has certain limitations. The 3D image of LA can be intraprocedurally reconstructed by a rotational angiography technique. Methods: Forty-six patients undergoing AF ablation were included in this study. Preprocedural CT imaging and intraprocedural reconstructing 3D rotational angiogram (3DRA) of LA were performed in all the patients. Rapid ventricular pacing (RVP, 300 ms) was used to inhibit the drainage of atrium. During RVP, contrast medium was injected into the LA, and rotational angiography was performed. The 3DRA was reconstructed and was registered with the live fluoroscopy. The 3DRA was evaluated in comparison to the CT image. In the navigation of the registered 3DRA, the ablation of AF was performed. Results: Forty-four 3DRAs (95.7%) were successfully reconstructed and registered with the live fluoroscopy. The LA anatomy was delineated in the 3DRA in comparison to a CT image. AF ablation was successfully performed in the 44 patients in the navigation of the registered 3DRA. There were good correlations in the PV ostial diameter and the LA volume as assessed by 3DRA in comparison to a CT image (r >= 0.87). The radiation exposure in rotational angiography was substantially less than that in CT scanning (2.7 ± 0.9 mSv vs. 24.9 ± 3.1 mSv, P < 0.001). Conclusions: It is feasible to reconstruct and register the 3DRA with live fluoroscopy using the RVP method during the ablation of AF. [ABSTRACT FROM AUTHOR]

Abstract: Trimethoprim–sulfamethoxazole (TMP–SMZ) is one of the most commonly used antibiotics. Although many of its adverse effects are well recognized, TMP–SMZ related hepatotoxicity is considered rare and is usually characterized by cholestasis or mixed hepatocellular–cholestatic reactions. In this study, we describe the case of a previously healthy young man with acute fulminant liver failure caused by TMP–SMZ. The patient presented with complaints of ‘flu-like’ symptoms with myalgia and fever after taking TMP–SMZ for 7 d for otitis externa. The patient subsequently developed fever, worsening jaundice, and a rash on his neck and chest. Liver enzymes peaked on day 3 with alanine aminotransferase (ALT) 11 549, aspartate aminotransferase (AST) 23 289, alkaline phosphatase 245, and total bilirubin 10.3 mg/dL, with a conjugated bilirubin of 8.3 mg/dL, prothrombin time (PT) 60.5 s, partial normalized ratio (PTT) 49 s, and international normalized ratio (INR) 7.5. Of note, acetaminophen level on admission was undetectable. Serology for hepatitis A, B, C, cytomegalovirus, HIV, toxoplasmosis, and blood cultures were all negative. The patient developed hepatic encephalopathy with hallucination on day 4. Laboratory tests revealed a serum ammonia level of 190 U, serum creatinine kinase (CK) 10 466 (42 on admission), serum creatinine 8.2 mg/dL (1.2 on admission), and significant metabolic acidosis. Renal ultrasound was unremarkable. The patient was started on hemodialysis for acute renal failure. Meanwhile, liver transplantation assessment was also initiated. On day 8 post-admission (15 d after taking TMP–SMZ), the patient received a successful orthotopic liver transplant. [ABSTRACT FROM AUTHOR]

A highly electrically conductive linear low-density polyethylene/graphene nanoplate composite with segregated structure (s-LLDPE/GN) was prepared by Yongmei Ma and colleagues through an environmentally friendly method. SEM images show that GN has been successfully coated on the LLDPE granule surfaces. First, GN coated LLDPE granules were prepared by aqueous dispersion, gradually drying. [Extracted from the article]

Metal‐organic frameworks bearing coordinatively unsaturated metal sites (CUSs) exhibit distinctive interactions toward guest molecules, thereby presenting intriguing properties in photocatalytic applications. Herein, an adaptable strategy is established to create 2D metal‐porphyrin frameworks while engineering the CUSs based on the use of bivalent metal nodes (Zn2+, Co2+, Cu2+, Ni2+, Cd2+) and Zr‐O clusters. The strong surface‐coordination effect reduces the energy barriers to activate acrylate monomers adsorbed to the nanosheet frameworks, enabling the generation of anion radicals through a broadband light‐induced electron transfer pathway. Particularly, the photocatalytic cycle offers a hole‐mediated deactivation mechanism to regulate the radical concentrations in the polymerization system, while the propagating chains exhibit a surface‐confined growth behavior that significantly inhibits recombination terminations. Extensive mechanistic studies and theoretical calculations reveal the molecular‐level guest‐framework interactions and establish the guidelines to screen metal centers for fabricating valid photocatalysts and monomers compatible with photo‐regulated polymerization. A series of ultrahigh molecular weight polymers with Mn > 1 000 000 and relatively low dispersity (Đ ≈ 1.5) are obtained upon exposure to the full spectrum of visible light. This study provides novel inspirations for harnessing natural sunlight to drive macromolecular synthesis with minimal energy consumption. [ABSTRACT FROM AUTHOR]