RESUMO
Directional electron flow in the photocatalyst enables efficient charge separation, which is essential for efficient photocatalysis of H2 production. Here, we report a novel class of tetracationic cyclophanes (7) incorporating bipyridine Pt(II) and selenoviologen. X-ray single-crystal structures reveal that 7 not only fixes the distances and spatial positions between its individual units but also exhibits a box-like rigid electron-deficient cavity. Moreover, host-guest recognition phenomena are observed between 7 and ferrocene, forming host-guest complexes with a 1:1 stoichiometry in MeCN. 7 exhibits good redox properties, narrow energy gaps, and strong absorption in the visible range (370-500 nm) due to containing two selenoviologen (SeV2+) units. Meanwhile, the femtosecond transient absorption (fs-TA) reveals that 7 has stabilized dicationic biradical, efficient charge separation, and facilitates directional electron flow to achieve efficient electron transfer due to the formation of rigid cyclophane and electronic architecture. Then, 7 is applied to visible-light-driven hydrogen evolution with high hydrogen production (132 µmol), generation rate (11 µmol/h), turnover number (221), and apparent quantum yield (1.7%), which provides a simplified and efficient photocatalytic strategy for solar energy conversion.
RESUMO
Neutral aqueous organic redox flow batteries (AORFBs) hold the potential to facilitate the transition of renewable energy sources from auxiliary to primary energy, the commercial production of anolyte materials still suffers from insufficient performance of high-concentration and the high cost of the preparation problem. To overcome these challenges, this study provides a hydrothermal synthesis methodology and introduces the charged functional groups into hydrophobic naphthalene diimide cores, and prepares a series of high-performance naphthalene diimide anolytes. Under the synergistic effect of π-π stacking and H-bonding networks, the naphthalene diimide exhibits excellent structural stability and the highest water solubility (1.85â M for dex-NDI) reported to date. By employing the hydrothermal method, low-cost naphthalene diimides are successfully synthesized on a hundred-gram scale of $0.16â g-1 ($2.43â Ah-1), which is also the lowest price reported to date. The constructed full battery achieves a high electron concentration of 2.4â M, a high capacity of 54.4â Ah L-1, and a power density of 318â mW cm-2 with no significant capacity decay observed during long-duration cycling. These findings provide crucial support for the commercialization of AORFBs and pave the way for revolutionary developments in neutral AORFBs.
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Bimolecular or tetramolecular G-quadruplexes (GQs) are predominantly self-assembled by the same sequence-identical G-rich oligonucleotides and usually remain inert to the strand displacement reaction (SDR) with other short G-rich invading fragments of DNA or RNA. Appealingly, in this study, we demonstrate that a parallel homomeric bimolecular GQ target of Tub10 d(CAGGGAGGGT) as the starting reactant, although completely folded in K+ solution and sufficiently stable (melting temperature of 57.7 °C), can still spontaneously accept strand invasion by a pair of short G-rich invading probes of P1 d(TGGGA) near room temperature. The final SDR product is a novel parallel heteromeric trimolecular GQ (tri-GQ) of Tub10/2P1 reassembled between one Tub10 strand and two P1 strands. Here we present, to the best of our knowledge, the first NMR solution structure of such a discrete heteromeric tri-GQ and unveil a unique mode of two probes vs one target in mutual recognition among G-rich canonical DNA oligomers. As a model system, the short invading probe P1 can spontaneously trap G-rich target Tub10 from a Watson-Crick duplex completely hybridized between Tub10 and its fully complementary strand d(ACCCTCCCTG). The Tub10 sequence of d(CAGGGAGGGT) is a fragment from the G-rich promoter region of the human ß2-tubulin gene. Our findings provide new insights into the Hoogsteen pairing-based SDR between a GQ target and double invading probes of short G-rich DNA fragments and are expected to grant access to increasingly complex architectures in GQ-based DNA nanotechnology.
Assuntos
Quadruplex G , Humanos , DNA/química , Oligonucleotídeos/química , Recombinação Genética , RNARESUMO
BACKGROUND: Bacillus cereus infections in immunocompetent patients are uncommon and mainly observed in fragile patients. It can cause lethal infections with multiple organ dysfunction syndrome (MODS). However, a patient presenting as venous sinus thrombosis and survival without sequela has not been reported. CASE PRESENTATION: A 20-year-old previously healthy male developed gastroenteritis after a meal, followed by fever, convulsions, and severe disturbance of consciousness. The patient had significant leukocytosis with a mildly elevated D-dimer, creatinine level, and respiratory failure. The CT(computed tomography) revealed fatal brain edema and subarachnoid hemorrhage. Previous blood culture in a local hospital revealed B. cereus, which was confirmed by mNGS(metagenomic next-generation sequencing) using blood and urine in our hospital. Accordingly, B. cereus sepsis with MODS were considered. Later, cerebral venous sinus thrombosis was proved. After anti-infection (linezolid 0.6 g, Q12h; and meropenem 1.0 g, Q8h), anti-coagulant (enoxaparin 6000U, Q12h), and other symptomatic treatments, the patient recovered completely without sequela at the 6-month follow-up. CONCLUSIONS: This case suggests that in immunocompetent adults, there is still a risk of infection with B. cereus, causing severe MODS. Special attention should be paid to venous sinus thrombosis and subarachnoid hemorrhage in such cases, while, anti-coagulant is essential therapy.
Assuntos
Sepse , Trombose dos Seios Intracranianos , Hemorragia Subaracnóidea , Humanos , Masculino , Adulto , Adulto Jovem , Hemorragia Subaracnóidea/etiologia , Bacillus cereus , Sepse/complicações , Sepse/diagnóstico , Sepse/tratamento farmacológico , Trombose dos Seios Intracranianos/complicaçõesRESUMO
OBJECTIVE: To observe the effects of blood activating wind dissipating acupuncture (BAWDA) on blood pressure (BP) of prehypertension (PHT) patients. METHODS: Totally 60 PHT patients were assigned to the control group and the acupuncture group according to random digit table, 30 in each group. All patients were intervened by life style. BAWDA was additionally performed in patients in the acupuncture group for 6 weeks (30 times). The improvement of BP after intervened by acupuncture was observed. BP success rates and the proportion of PHT progressing to hypertension (HT) were also observed after 6-week intervention of acupuncture and at 1-year follow-up. RESULTS: Systolic blood pressure (SBP) and diastolic blood pressure (DBP) decreased after 6-week intervention in the acupuncture. The BP control rate was 56.7% (17/30 cases) in the acupuncture group vs.10.0% (3/30 cases) in the control group with statistical difference (chi2 = 14.70, P < 0.01). At 1-year follow-up BP success rate was 36.7% (11/30 cases) in the acupuncture group, remarkably higher than that of the control group [13.3%, (4/30 cases)] (chi2 = 4.36, P < 0.05). CONCLUSIONS: BAWDA showed BP regulating roles in a gradually stable decreasing tendency. It also could elevate BP success rate of PHT, and reduce the risk of PHT progressing to HT.
Assuntos
Terapia por Acupuntura/métodos , Pressão Sanguínea , Pré-Hipertensão/terapia , Acupuntura/métodos , Humanos , Hipertensão , VentoRESUMO
Naphthalene diimide derivatives show great potential for application in neutral aqueous organic redox flow batteries (AORFBs) due to their highly conjugated molecular structure and stable two-electron storage capacity. However, the two-electron redox process of naphthalene diimides typically occurs via two separate steps with the transfer of one electron per step ("two-step two-electron" transfer process), which leads to an inevitable loss of voltage and energy. Herein, we report a novel regional charge buffering strategy that utilizes the core-substituted electron-donating group to adjust the redox properties of naphthalene diimides, realizing two electron transfer via a single-step redox process ("one-step two-electron" transfer process). The symmetrical battery testing of NDI-DEtOH revealed exceptional intrinsic stability lasting for 11 days with a daily decay rate of only 0.11%. Meanwhile, AORFBs with NDI-DMe/FcNCl and NDI-DEtOH/FcNCl exhibited a remarkable 40% improvement in peak power density at 50% state of charge (SOC) in comparison to NDI/FcNCl-based AORFBs. In addition, the battery's energy efficiency has increased by 24%, resulting in much more stable output power and significantly improved energy efficiency. These results are of great significance to practical applications of AORFBs.
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Metal sulfide-based homojunction photocatalysts are extensively explored with improved photocatalytic performance. However, the construction of metal sulfide-based S-scheme homojunction remains a challenge. Herein, the fabrication of 2D CdIn2S4 nanosheets coated 3D CdIn2S4 octahedra (referred to as 2D/3D n-CIS/o-CIS) S-scheme homojunction photocatalyst is reported by simply adjustment of polyvinyl pyrrolidone amount during the solvothermal synthesis. The formation of S-scheme homojunction within n-CIS/o-CIS is systematically investigated via a series of characterizations, which can generate an internal electric field to facilitate the separation and migration of photogenerated electron-hole pairs. The 2D/3D n-CIS/o-CIS composite exhibits significantly improved photocatalytic activity and stability in the selective oxidation of phenylcarbinol (PhCH2OH) to benzaldehyde (PhCHO) when compared to pure n-CIS and o-CIS samples under visible light irradiation. It is hoped that this work can contribute novel insights into the development of metal sulfides S-scheme homojunction photocatalysts for solar energy conversion.
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A series of chalcogenophene viologens ([(NPr)2FV]Cl4, [(NPr)2TV]Cl4, and [(NPr)2SeV]Cl4) as anolytes for neutral aqueous organic redox flow batteries (AORFBs) via a combination of chalcogenophenes (furan, thiophene, and selenophene) and viologens are reported. The chalcogenophene viologens showed narrow HOMO-LUMO energy gap, high solubility, and stable electrochemical properties. Compared with the parent [(NPr)2V]Cl4, the introduction of π-conjugated chalcogenophene groups reduced the redox potential and enhanced the stability of their free radical state, which endowed the chalcogenophene viologens/FcNCl-based AORFBs with a higher theoretical battery voltage of 1.20 V and enhanced stability for one-electron storage. In particular, the [(NPr)2FV]Cl4/FcNCl-based AORFB exhibited excellent long-cycle stability for 3000 cycles with 0.0006% capacity decay per cycle for one-electron storage and 300 cycles with 0.06% capacity decay per cycle for two-electron storage at a charge voltage of 1.9 V (1.42 V theoretical battery voltage). This work provided a new strategy for regulating the voltage and improving the performance of neutral AORFBs.
RESUMO
Osteosarcoma (OS) is a type of primary malignant cancer occurring in the bone and poses a threat to the lives of children and young adults. Long noncoding RNAs (lncRNAs) have been certified to play important roles in various human malignant tumors, including OS. lncRNA KCNQ1OT1 has been investigated in certain types of cancer; however, its role and molecular mechanisms in OS remain to be determined. In the present study, a high KCNQ1OT1 expression was detected in human OS tissues and cell lines. Moreover, patients with OS with a high expression of KCNQ1OT1 presented a worse prognosis. Lossoffunction assays demonstrated that KCNQ1OT1 silencing suppressed cell proliferative, migratory and invasive abilities in OS. Importantly, the knockdown of KCNQ1OT1 suppressed the Wnt/ßcatenin signaling pathway in OS. In vivo assays displayed the inhibitory role of the silencing of KCNQ1OT1 in OS tumor growth. As regards the underlying mechanisms, KCNQ1OT1 could sponge miR3666, and its expression was negatively associated with that of miR3666 in OS tissues. Thereafter, Kruppellike factor 7 (KLF7), upregulated in OS tissues and cells, was discerned as a target gene of miR3666. Furthermore, KLF7 expression negatively correlated with miR3666 expression, whereas it positively correlated with KCNQ1OT1 expression. A rescue assay delineated that the overexpression of KLF7 counteracted the KCNQ1OT1 knockdowninduced suppression of OS cell proliferation, migration, invasion and Wnt/ßcatenin signaling. Collectively, the present study demonstrates that KCNQ1OT1 facilitates OS progression and activates Wnt/ßcatenin signaling by targeting the miR3666/KLF7 axis.
Assuntos
Neoplasias Ósseas/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , MicroRNAs/metabolismo , Proteínas de Neoplasias/metabolismo , Osteossarcoma/metabolismo , RNA Neoplásico/metabolismo , Via de Sinalização Wnt , beta Catenina/metabolismo , Neoplasias Ósseas/genética , Neoplasias Ósseas/patologia , Linhagem Celular Tumoral , Humanos , Fatores de Transcrição Kruppel-Like/genética , MicroRNAs/genética , Proteínas de Neoplasias/genética , Osteossarcoma/genética , Osteossarcoma/patologia , Canais de Potássio de Abertura Dependente da Tensão da Membrana/genética , Canais de Potássio de Abertura Dependente da Tensão da Membrana/metabolismo , RNA Neoplásico/genética , beta Catenina/genéticaRESUMO
BACKGROUND: 5-fluorouracil (5-FU) is a widely used drug for cancer treatment, but its effect and underlying mechanisms on osteosarcoma (OS) cells remain unclear. METHODS: U2OS and MG63 cells were treated with 0, 50, 100, and 500 µM 5-FU. MTS and flow cytometry were used to examine the effect of 5-FU on cell viability and apoptosis, respectively. Circular RNA (circRNA) expression was detected using RNA sequencing and quantitative real-time PCR (qPCR). Differentially expressed circRNAs were further subjected to the Kyoto Encyclopedia of Genes and Genomes (KEGG) and gene ontology (GO) analysis to predict their functions. A circRNA-miRNA-mRNA interaction network was generated to analyze the regulatory networks of 5-FU-induced differentially expressed circRNAs. Western blotting (WB) was used to verify the protein in the downstream of circRNAs. RESULTS: 5-FU inhibited the cell viability of the MG63 cells in a concentration-dependent manner. The most significant effect was observed in the cells treated with 500 µM 5-FU. Apoptosis was also increased in the MG63 cells after 500 µM 5-FU treatment for 3 days. RNA sequencing results showed that 183 differentially expressed circRNAs (172 upregulated and 11 downregulated) in 5-FU-treated cells. KEGG and GO analysis showed that the differentially expressed circRNAs were primarily enriched in proliferation-, apoptosis-, and metabolism-related functions. qPCR was used to verify the most upregulated and downregulated circRNAs. The circRNA-miRNA-mRNA interaction network showed that these 8 circRNAs had a sizable regulatory network that links a series of genes involved in tumor suppression. CONCLUSION: 5-FU treatment resulted in the differentially expressed circRNAs that were proliferation- and apoptosis-associated and were involved in the 5-FU-induced inhibition of tumor proliferation in OS cells.
Assuntos
Proliferação de Células/efeitos dos fármacos , Fluoruracila/farmacologia , Osteossarcoma/tratamento farmacológico , RNA Circular/genética , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Osteossarcoma/genética , Osteossarcoma/patologiaRESUMO
Monitoring subtle temperature changes noninvasively remains a challenge for magnetic resonance imaging (MRI). A temperature-sensitive contrast agent based on thermosensitive microgel is proposed and synthesized using a manganese tetra(3-vinylphenyl) porphyrin core reacting with N-isopropylacrylamide (NIPAM) or N-isopropylmethacrylamide (NIPMAM) monomers and N,N'-methylenebis(acrylamide) (MBA) cross-linkers. The volume of the NIPAM-incorporated microgel (M-1) decreased sharply around its lower critical solution temperature (LCST, 29-33 °C), whereas the volume of the NIPMAM-incorporated microgel (M-2) decreased gradually. MR longitudinal relaxivity (r1) enhancement (44%) was obtained for M-1, while the corresponding change for M-2 was much smaller. M-1 was further optimized in synthesis without an MBA cross-linker to obtain M-3 which showed a 67% increase in r1 around its LCST. Our results suggested that the longitudinal relaxivity is strongly modulated by microgel volume change around the LCST, leading to a significant increase in r1. This novel thermally sensitive microgel could potentially be applied to monitor small temperature changes using MRI methods.