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1.
Molecules ; 26(22)2021 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-34833938

RESUMO

Fluorescent metal-organic frameworks (MOFs) are ideal materials for sensors because of their adjustable pore size and functional groups, which provide them with favorable metal ion selective recognition. In this paper, a new cadmium-based MOF was synthesized using Cd(NO3)2·4H2O and 3,3',5,5'-biphenyltetracarboxylic acid by solvothermal method. CdBPTC owned three types of channels with dimensions of approximately 8.4 × 8.3 Å, 6.0 × 5.2 Å, 9.7 × 8.4 Å along a, b, and c axis, respectively. This MOF has high selectivity to ferric ions and shows excellent anti-inference ability toward many other cations. The results indicate that the fluorescence quenching efficiency of CdBPTC is close to 100% when the concentration of Fe3+ reaches 1.0 × 10-3 mol·L-1. Moreover, the luminescent intensity at 427 nm presents a linear relationship at a concentration range of 2.0 × 10-4~7.0 × 10-4 mol·L-1, which can be quantitatively expressed by the linear Stern-Volmer equation I0/I = 8489 [Fe3+] - 0.1400, which is comparable to the previously reported better-performing materials. Competitive energy absorption and ion exchange may be responsible for the variation in fluorescence intensity of CdBPTC in different Fe3+ concentrations.

2.
Inorg Chem ; 2021 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-34762406

RESUMO

The reaction of [Ni(1,5-COD)2] (1.0 equiv), PEt3 (0.04 equiv), SePEt3 (0.52 equiv), and [NiCl2(PEt3)2] (0.07 equiv) in a mixture of toluene and THF results in the formation of [Ni23Se12Cl3(PEt3)10] (1), which can be isolated in moderate yield after workup. Complex 1 was characterized by NMR spectroscopy, ESI-MS, and X-ray crystallography. This open-shell nanocluster features a central [Ni13]7+ anticuboctahedral kernel, which is encapsulated by a [Ni10(µ-Se)9Cl3]- shell, along with ten PEt3 ligands and three (µ4-Se)2- ligands. On the basis of our spectroscopic and crystallographic analysis, coupled with in situ spectroscopic monitoring, we believe that the previously reported nanocluster, [Ni23Se12(PEt3)13], is actually better formulated as [Ni23Se12Cl3(PEt3)10].

3.
Acc Chem Res ; 2021 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-34806374

RESUMO

ConspectusElectron-deficient boron-based catalysts with metal-free but metallomimetic characteristics provide a versatile platform for chemical transformations. However, their catalytic performance is usually lower than that of the corresponding metal-based catalysts. Furthermore, many elaborate organoboron compounds are produced via time-consuming multistep syntheses with low yields, presenting a formidable challenge for large-scale applications of these catalysts. Given this context, the development of organoboron catalysts with the combined advantages of high efficiency and easy preparation is of critical importance.Therefore, we envisioned that the construction of a dynamic Lewis multicore system (DLMCS) by integrating the Lewis acidic boron center(s) and a Lewis basic ammonium salt in one molecule would be particularly efficient for on-demand applications because of the intramolecular synergistic effect. This Account summarizes our recent efforts in developing modular organoboron catalysts with unprecedented activities for several chemical transformations. A series of mono-, di-, tri-, and tetranuclear organoboron catalysts was readily designed and prepared in nearly quantitative yields over two steps using commercially available feedstocks. Notably, these catalysts can be modularly tailored by fine control over the electrophilic property of the Lewis acidic boron center(s), electronic and steric effects of the electropositive ammonium cation, linker length between the boron center and the ammonium cation, the number of boron centers, and the nucleophilic anion. This modular design allows systematic manipulation of the reactivity and efficacy of the catalysts, thus optimizing suitable catalysts for versatile chemical transformations. These include the coupling of CO2 and epoxides, copolymerization of CO2 and epoxides, ring-opening polymerization (ROP) of epoxides, and ring-opening copolymerization (ROCOP) of epoxides and cyclic anhydrides.The utilization of mononuclear organoboron catalysts provided a turnover frequency of 11050 h-1 for the CO2/propylene oxide coupling reaction, an unprecedented efficiency of 5.0 kg of polymer/g of catalyst for the copolymerization of CO2 and cyclohexene oxide, and a record-breaking catalytic efficiency of 7.4 kg of polymer/g of catalyst for the ROCOP of epoxides with cyclic anhydrides. A turnover number of 56500 was observed at a catalyst loading of 10 ppm for the ROP of epoxides using the dinuclear catalysts. The tetranuclear organoboron catalysts realized the previously intractable task of the copolymerization of CO2 and epichlorohydrin, producing poly(chloropropylene carbonate) with the highest molecular weight of 36.5 kg/mol reported to date.Furthermore, the study revealed that the interaction between the dynamic Lewis multicore, that is, the intramolecular synergistic effect between the boron center(s) and the quaternary ammonium salt, plays a key role in mediating the catalytic activity and selectivity. This was based on investigations of the crystal structures of the catalysts, key intermediates, reaction kinetics, and density functional theory calculations. The modular tactics for the construction of organoboron catalysts presented in this Account should inspire more advanced catalyst designs.

4.
Artigo em Inglês | MEDLINE | ID: mdl-34787998

RESUMO

The detection of harmful trace gases, such as formaldehyde (HCHO), is a technical challenge in the current gas sensor field. The weak electrical signal caused by trace amounts of gases is difficult to be detected and susceptible to other gases. Based on the amplification effect of a field-effect transistor (FET), a carbon-based FET-type gas sensor with a gas-sensing gate is proposed for HCHO detection at the ppb level. Semiconducting carbon nanotubes (s-CNTs) and a catalytic metal are chosen as channel and gate materials, respectively, for the FET-type gas sensor, which makes full use of the respective advantages of the channel transport layer and the sensitive gate layer. The as-prepared carbon-based FET-type gas sensor exhibits a low detection limit toward HCHO up to 20 ppb under room temperature (RT), which can be improved to 10 ppb by a further heating strategy. It also exhibits a remarkable elevated recovery rate from 80 to 97% with almost no baseline drift (2%) compared to the RT condition, revealing excellent reproducibility, stability, and recovery. The role of sensitive function in the FET-type gas sensor is performed by means of an independent gas-sensing gate, that is, the independence of the sensitive gate and the electron transmission channel is the main reason for its high sensitivity detection. We hope our work can provide an instructive approach for designing high-performance formaldehyde sensor chips with on-chip integration potential.

5.
ANZ J Surg ; 2021 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-34636468

RESUMO

BACKGROUND: The surgical management of left-sided malignant large bowel obstruction (MLBO) is associated with high morbidity and mortality. Recently, self-expandable metallic colonic stent (SEMS) and transanal decompression tube (TDT) used as a 'bridge to surgery' (BTS) have been widely used. This study aims to compare the clinical outcomes and oncological safety of SEMS and TDT as BTS to transform MLBO into elective surgery. METHODS: Between February 2013 and March 2019, 62 patients with MLBO received SEMS (n = 32) or TDT (n = 30), and elective one-stage surgery later. We evaluated decompression efficiency and oncological safety in selective operation in TDT and SEMS groups, including preoperative preparation time, surgical approach, number of lymphatic dissection and vascular invasion, ulcer formation and histopathological findings of resected specimens. RESULTS: The preoperative preparation time in the SEMS group was shorter than that of the TDT group (P < 0.05). However, there was no significant difference between the groups in postoperative length of hospital stay (P > 0.05). The number of vascular invasions in the TDT group was less than that in the SEMS group (P < 0.05). Furthermore, the risk of wound abscess and ulcer formation in the TDT group was significantly lower than that in the SEMS group (P < 0.05). CONCLUSION: Our findings suggest that SEMS is associated with a relatively poor oncological outcome and the placement of TDT as BTS in MLBO patients may be a better alternation.

6.
Artigo em Inglês | MEDLINE | ID: mdl-34586349

RESUMO

Mucin 1 (MUC1) has been regarded as an ideal target for cancer treatment, since it is overexpressed in a variety of different cancers including the majority of breast cancer. However, there are still no approved monoclonal antibody drugs targeting MUC1. In this study, we generated a humanized MUC1 (HzMUC1) antibody from our previously developed MUC1 mouse monoclonal antibody that only recognizes MUC1 on the surface of tumor cells. Furthermore, an antibody-drug conjugate (ADC) was generated by conjugating HzMUC1 with monomethyl auristatin (MMAE), and the efficacy of HzMUC1-MMAE on the MUC1-positive HER2+ breast cancer in vitro and in 'Xenograft' model was tested. Results from western blot analysis and immunoprecipitation revealed that the HzMUC1 antibody did not recognize cell-free MUC1-N in sera from breast cancer patients. Confocal microscopy analysis showed that HzMUC1 antibody bound to MUC1 on the surface of breast cancer cells. Results from mapping experiments suggested that HzMUC1 may recognize an epitope present in the interaction region between MUC1-N and MUC1-C. Results from colony formation assay and flow cytometry demonstrated that HzMUC1-MMAE significantly inhibited cell growth by inducing G2/M cell cycle arrest and apoptosis in trastuzumab-resistant HER2-positive breast cancer cells. Meanwhile, HzMUC1-MMAE significantly reduced the growth of HCC1954 xenograft tumors by inhibiting cell proliferation and enhancing cell death. In conclusion, our results indicate that HzMUC1-ADC is a novel therapeutic drug that can overcome trastuzumab resistance of breast cancer. HzMUC1-ADC should also be an effective therapeutic drug for the treatment of different MUC1-positive cancers in clinic.

7.
Inorg Chem ; 60(20): 15413-15420, 2021 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-34585570

RESUMO

The reaction of [AnCl(NR2)3] (An = U or Th; R = SiMe3) with NaCCH and tetramethylethylenediamine (TMEDA) results in the formation of [An(C≡CH)(NR2)3] (1, An = U; 2, An = Th), which can be isolated in good yields after workup. Similarly, the reaction of 3 equiv of NaCCH and TMEDA with [AnCl(NR2)3] results in the formation of [Na(TMEDA)][An(C≡CH)2(NR2)3] (4, An = U; 5, An = Th), which can be isolated in fair yields after workup. The reaction of 1 with 2 equiv of KC8 and 1 equiv of 2.2.2-cryptand in tetrahydrofuran results in formation of the uranium(III) acetylide complex [K(2.2.2-cryptand)][U(C≡CH)(NR2)3] (3). Thermolysis of 1 or 2 results in formation of the bimetallic dicarbide complexes [{An(NR2)3}2(µ,η1:η1-C2)] (6, An = U; 7, An = Th), whereas the reaction of 1 with [Th{N(R)(SiMe2CH2)}(NR2)2] results in the formation of [U(NR2)3(µ,η1:η1-C2)Th(NR2)3] (8). The 13C NMR chemical shifts of the α-acetylide carbon atoms in 2, 5, and 7 exhibit a characteristic spin-orbit-induced downfield shift, due to participation of the 5f orbitals in the Th-C bonds. Magnetism measurements demonstrate that 6 displays weak ferromagnetic coupling between the uranium(IV) centers (J = 1.78 cm-1).

8.
DNA Cell Biol ; 40(10): 1251-1260, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34491823

RESUMO

Microsatellite instability (MSI) is emerging as a promising subtype related to immunotherapy in gastric cancer (GC). However, the underlying mechanism between MSI and microsatellite stability (MSS) remains unclear. In this study, we conducted a weighted gene co-expression network analysis and found that the expression of heterogeneous nuclear ribonucleoprotein L (HNRNPL) was significantly increased in MSI GC compared with MSS GC. This finding was further validated in public GC cohorts and commercialized human GC tissue microarray. The significant negative correlation with the expression of mismatch repair protein mutL homolog 1 (MLH1) may be one of the potential mechanisms for the upregulation of HNRNPL expression in MSI GC (R = -0.689, p = 8.59e-11). In addition, HNRNPL expression was markedly upregulated in GC tissues compared with adjacent normal tissues. High HNRNPL expression also predicted a poor prognosis in GC patients. Finally, gene set enrichment analysis revealed that high HNRNPL MSI GC samples were highly positive associated with the biological functions of inflammation and cell proliferation, such as interferon gamma response, MYC targets, E2F targets, and G2/M checkpoints. In conclusion, HNRNPL could be a new MSI-associated prognostic biomarker in GC and could be a new target for the MSI GC treatment.


Assuntos
Biomarcadores Tumorais/genética , Instabilidade Genômica , Repetições de Microssatélites , Ribonucleoproteínas/genética , Neoplasias Gástricas/genética , Idoso , Biomarcadores Tumorais/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Proteína 1 Homóloga a MutL/genética , Proteína 1 Homóloga a MutL/metabolismo , Ribonucleoproteínas/metabolismo , Neoplasias Gástricas/patologia , Regulação para Cima
9.
Adv Exp Med Biol ; 1330: 125-137, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34339034

RESUMO

OBJECTIVES: We tested if METCAM/MUC18 overexpression also plays a suppressor role in another human ovarian cancer cell line, BG-1, in addition to the SK-OV3 cell line. METHODS: Human ovarian cancer BG-1 cells were transfected with METCAM/MUC18 cDNA and G418-resistant clones expressing different levels of METCAM/MUC18 were isolated. These clones were used to test the effects of enforced expression of METCAM/MUC18 on in vitro motility, invasiveness, and anchorage-independent colony formation (in vitro tumorigenesis), and in vivo tumorigenesis after SC injection and after IP injection in female athymic nude mice. RESULTS: Overexpression of METCAM/MUC18 reduced in vitro motility and invasiveness of BG-1 cells and anchorage-independent colony formation (in vitro tumor formation). Higher expression of METCAM/MUC18 in BG-1 cells significantly reduced in vivo tumor proliferation of the BG-1 cells after IP injection (orthotopic route) of the clones in female nude mice, though it did not significantly affect in vivo tumor proliferation after SC injection (non-orthotopic route). CONCLUSION: Similar to SK-OV3 cells, METCAM/MUC18 also plays a suppressor role in the progression of BG-1 cells in a xenograft mouse model.


Assuntos
Carcinogênese , Neoplasias Ovarianas , Animais , Antígeno CD146 , Carcinogênese/genética , Linhagem Celular Tumoral , Feminino , Humanos , Camundongos , Camundongos Nus , Invasividade Neoplásica , Neoplasias Ovarianas/genética
10.
Zhongguo Ying Yong Sheng Li Xue Za Zhi ; 37(4): 423-428, 2021 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-34374265

RESUMO

Objective: To investigate the role and mechanism of progranulin (PGRN) in asthma. Methods: Control group and model group were set up in wild and IL-6 knockout (IL-6 ko) mice, respectively. For asthma model, mice were intraperitoneally sensitized with 100 µg OVA on days 0 and 7, followed by aerosol challenges with 5% OVA for 30 min per day from day 14 to 21, and mice were sacrificed 24 h after the last challenge. The mice in control group were treated in the same way with PBS. Bronchoalveolar lavage fluid (BALF) was collected for leukocytes count and differential count. The pathological changes of lung tissues were observed by H&E staining. The cytokines in lung homogenate, serum and BALF were detected by Q-PCR and ELISA. The in vitro model of asthma was induced by stimulating A549 or BEAS-2B cells with IL-13. Each group was replicated in three wells and four groups were designed: PBS group, IL-13 treatment group, IL-13 + rhPGRN treatment group, inhibitors of p38 phosphorylation (SB203508) treatment group. The cells or supernatant were collected after 0~48 h. PGRN and IL-6 levels were determined by Q-PCR and ELISA, the level of p38 phosphorylation was tested by Western blot (WB). Results: Compared with control group, PGRN levels were decreased in lung homogenate and BALF (P<0.05), and PGRN presented a downtrend in serum, however, the level of IL-6 in BALF was increased in asthma mice (P<0.01). In IL-6 ko asthma mice, compared with the wild asthma mice, leukocytes, especially neutrophils in BALF were decreased (P<0.05), but PGRN was increased (P<0.05), lung pathological damage was significantly alleviated. In vitro experiments, compared with PBS group, PGRN level was decreased (P<0.05), IL-6 level was increased (P<0.01), phosphorylation of p38 was activated in IL-13 treatment group. Compared with IL-13 treatment group, in IL-13 + PGRN treatment group, IL-6 level was decreased (P<0.05); phosphorylation of p38 was inhibited (P<0.05); and the production of IL-6 (P<0.05) was decreased after treatment with inhibitor of p38 phosphorylation. Conclusion: PGRN inhibited the production of IL-6 by suppressing the p38 phosphorylation to alleviate asthmatic airway inflammation.


Assuntos
Asma , Interleucina-6 , Animais , Asma/tratamento farmacológico , Líquido da Lavagem Broncoalveolar , Modelos Animais de Doenças , Inflamação , Pulmão , Camundongos , Camundongos Endogâmicos BALB C , Ovalbumina , Progranulinas
11.
Ann Vasc Surg ; 2021 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-34437958

RESUMO

We here report 2 young cases of ruptured symptomatic tuberculous aortic pseudoaneurysm via endovascular repair with stent graft. Follow-up at 16 months post operation, these patients are in good condition. This case report shows that endovascular repair is effective and safe, and it has emerged as an accepted alternative to surgery for the treatment of tuberculous aortic pseudoaneurysm. But more cases will be needed to prove if it would leave behind the focus of infection.

12.
Kaohsiung J Med Sci ; 2021 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-34460994

RESUMO

Asthma is regarded as a chronic inflammation of the airway. Research has highlighted the significance of Vitamin D in asthma. This study explored the mechanism of vitamin D on asthma. The asthma mouse model was established by ovalbumin (OVA) sensitization and treated with vitamin D (50 or 100 ng/ml). The morphological changes of the airway were observed by HE staining. The serum IgE contents and MDA, ROS, and SOD expressions in the bronchoalveolar lavage fluid (BALF) were detected by ELISA. The Th17 and Treg cells were detected using flow cytometry. The RORγt and Foxp 3 expressions were detected by Reverse transcription quantitative polymerase chain reaction (RT-qPCR). IL-17, IL-10, and TGF-ß1 expressions were detected using ELISA. The NF-κB pathway was blocked using the NF-κB pathway inhibitor, Andrographolide sulfonate. The NF-κB pathway-related indexes were detected by western blotting. After blockade of the NF-κB pathway, the IL-17, IL-10, and TGF-G1 expressions were detected. OVA-sensitized asthma induced airway remodeling and elevated IgE content in mice, which was downregulated after vitamin D treatment. MDA and ROS were upregulated and SOD was downregulated in asthmatic mice, while vitamin D inverted the changes. Th17/Treg ratio was imbalanced, RORγt and IL-17 were upregulated, and Foxp 3, IL-10, and TGF-ß1 were downregulated after OVA sensitization, while vitamin D treatment inverted these changes and inhibited the NF-κB-p65 phosphorylation level. After blockade of the NF-κB pathway, IL-17 was downregulated and IL-10 and TGF-ß1 were upregulated. In conclusion, vitamin D rectified the Th17/Treg balance and alleviated airway inflammation by inhibiting the NF-κB pathway in asthmatic mice.

13.
Behav Brain Res ; 414: 113511, 2021 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-34358569

RESUMO

Prefrontal ischemia can cause impairments in learning and memory, executive functions and cognitive flexibility. However, the related cellular mechanisms at the early stage are still elusive. The present study used ischemic stroke in medial prefrontal cortex and systemically investigated the electrophysiological changes of the parvalbumin (PV+) interneurons 12 h post ischemia. We found that Ih and the related voltage sags in PV+ interneurons are downregulated post ischemia, which correlates with hyperpolarization of the membrane potentials and increased input resistance in these interneurons. Consistent with the suppression of Ih, postischemic PV+ interneurons exhibited a reduction in excitability and exerted a less inhibitory control over the neighboring pyramidal excitatory neurons. Moreover, we found that specifically chemogenetic activation of PV+ neurons at early stage ameliorated prefrontal ischemia-induced spatial working memory dysfunction in T-maze without effects on the locomotor coordination and balance. In contrast, suppression of PV+ neurons by blockade of Ih leaded to further aggravate the damage of spatial memory. These findings indicate that dysfunctional Ih in the PV+ neuron postischemia induces the imbalance of excitation and inhibition, which might represent a novel mechanism underlying the prefrontal ischemia-induced cognitive impairment.

14.
Histol Histopathol ; : 18358, 2021 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-34269397

RESUMO

BACKGROUND: Herein, we aimed to determine whether DAPK1 and its post-transcriptional regulator miR-361 were implicated in high glucose (HG)-induced podocyte injury and renal damage in db/db mice. MATERIALS AND METHODS: Podocytes were incubated with normal glucose (NG; 5 mM) or HG (30 mM). Podocyte apoptosis was evaluated using TUNEL staining. Lentiviral-delivered specific short hairpin RNA (shRNA) was designed to silence DAPK1 expression in podocytes. miR-361 agomir was administrated by tail intravenous injection in db/db diabetic mice to investigate the renoprotection of miR-361 in vivo. RESULTS: Exposure of podocytes to HG led to a significant increase in DAPK1 mRNA and protein levels and a decrease in miR-361 expression levels. Knockdown of DAPK1 attenuated HG-triggered growth inhibition, apoptosis, DNA damage and cell membrane damage in podocytes. Mechanically, DAPK1 was a direct target of miR-361. Transfection with miR-361 mimics into podocytes resulted in a significant decrease in the DAPK1 protein expression level. In addition, HG-induced the up-regulation of the DAPK1 protein expression level in podocytes was restrained by miR-361 mimics transfection. Intriguingly, overexpression of DAPK1 in HG-stimulated podocytes muted miR-361-mediated cytoprotection, including anti-apoptosis, resistance to DNA and membrane damage. In vivo, overexpression of miR-361 protected against hyperglycemia-induced podocyte loss, tubular atrophy and interstitial fibrosis in the kidney of db/db mice. Moreover, overexpression of miR-361 inhibited the protein expression of DAPK1 in the kidney of db/db mice. CONCLUSION: Our research presented a novel mechanism of HG-induced podocyte damage or renal lesion, supporting the miR-361/DAPK1 signaling pathway that could be used as a potential therapeutic target for the treatment of DN.

15.
Inorg Chem ; 60(16): 12436-12444, 2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-34328317

RESUMO

The reaction of AnCl4(DME)n (An = Th, n = 2; U, n = 0) with 5 equiv of LiC6Cl5 in Et2O resulted in the formation of homoleptic actinide-aryl "ate" complexes [Li(DME)2(Et2O)]2[Li(DME)2][Th(C6Cl5)5]3 ([Li][1]) and [Li(Et2O)4][U(C6Cl5)5] ([Li][2]). Similarly, the reaction of AnCl4(DME)n (An = Th, n = 2; U, n = 0) with 3 equiv of LiC6Cl5 in Et2O resulted in the formation of heteroleptic actinide-aryl "ate" complexes [Li(DME)2(Et2O)][Li(Et2O)2][ThCl3(C6Cl5)3] ([Li][3]) and [Li(Et2O)3][UCl2(C6Cl5)3] ([Li][4]). Density functional calculations show that the An-Cipso σ-bonds are considerably more covalent for the uranium complexes vs the thorium analogues, in line with past results. Additionally, good agreement between experiment and calculations is obtained for the 13Cipso NMR chemical shifts in [Li][1] and [Li][3]. The calculations demonstrate a deshielding by ca. 29 ppm from spin-orbit coupling effects originating at Th, which is a direct consequence of 5f orbital participation in the Th-C bonds.

16.
J Chem Phys ; 154(21): 211102, 2021 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-34240994

RESUMO

The reaction of 1.75 equiv of tBuNC with Ni(1,5-COD)2, followed by crystallization from benzene/pentane, resulted in the isolation of [Ni8(CNtBu)12][Cl] (2) in low yields. Similarly, the reaction of Ni(1,5-COD)2 with 0.6 equiv of [Ni(CNtBu)4], followed by addition of 0.08 equiv of I2, resulted in the formation of [Ni8(CNtBu)12][I] (3), which could be isolated in 52% yield after work-up. Both 2 and 3 adopt folded nanosheet structures in the solid state, characterized by two symmetry-related planar Ni4 arrays, six terminally bound tBuNC ligands, and six tBuNC ligands that adopt bridging coordination modes. The metrical parameters of the six bridging tBuNC ligands suggest that they have been reduced to their [tBuNC]2- form. In contrast to the nanosheet structures observed for 2 and 3, gas phase Ni8 is predicted to feature a compact bisdisphenoid ground state structure. The strikingly different structural outcomes reveal the profound structural changes that can occur upon addition of ligands to bare metal clusters. Ultimately, the characterization of 2 and 3 will enable more accurate structural predictions of ligand-protected nanoclusters in the future.

17.
Enzyme Microb Technol ; 148: 109808, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34116757

RESUMO

Cordyceps militaris carotenoids are widely used as food additives, animal feed supplements, and so on. However, the biosynthetic pathway of carotenoids in C. militaris is still obscure. In this paper, changes of mycelial morphology and carotenoid accumulation of C. militaris were investigated under oxidative (KMnO4) and osmotic stress (NaCl). Subsequently, qRT-PCR was employed to detect the expression levels of genes related to carotenogenesis to explore the mechanism of adaptation to abiotic stress. When the concentrations of KMnO4 and NaCl were respectively 0.4 g/L and 2 g/L, carotenoid accumulation reached a maximum of 6616.82 ±â€¯666.43 µg/g and 6416.77 ±â€¯537.02 µg/g. Under the oxidative stress condition of KMnO4, the expressions of psy and hsp70 increased significantly compared with control. Besides, the genes fus3 and hog1 were significantly enriched in the MAPK signal pathway. Compared with the control group, there was no significant difference in expression of psy in the NaCl group. Moreover, the accumulation of triacylglycerols may contribute significantly to the increase in carotenoid accumulation. The increased accumulation of antioxidant carotenoids induced under environmental stress is to resist oxidative conditions. Fus3 and Hog1 signaling in the MAPK pathway was activated and subsequently take effects on the resistance of oxidative condition by regulating related metabolic processes. C. militaris resist the stress of high oxygen by producing a large amount of glycerol and carotenoids when this fungus is cultured in a saline environment for a long time.


Assuntos
Agaricales , Cordyceps , Carotenoides , Cordyceps/genética , Estresse Fisiológico
18.
Angew Chem Int Ed Engl ; 60(35): 19253-19261, 2021 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-34109722

RESUMO

Producing polyesters with high molecular weight (Mn ) through ring-opening copolymerization (ROCOP) of epoxides with cyclic anhydrides remains a major challenge. Herein, we communicate a metal-free, highly active, and high thermoresistance system for the ROCOP of epoxides with cyclic anhydrides to prepare polyesters (13 examples). The organoboron catalysts can endure a reaction temperature as high as 180 °C for the ROCOP of cyclohexane oxide (CHO) with phthalic anhydride (PA) without the observation of any side reactions. The average Mn of the produced poly(CHO-alt-PA) climbed to 94.5 kDa with low polydispersity (Ð=1.19). Furthermore, an unprecedented turnover number of 9900, equivalent to an efficiency of 7.4 kg of polyester/g of catalyst, was achieved at a feed ratio of CHO/PA/catalyst=20000:10000:1 at 150 °C. Kinetic studies, crystal structure analysis, 11 B NMR spectra, and DFT calculations provided mechanistic justification for the effectiveness of the catalyst system.

19.
Biomed Res Int ; 2021: 8824059, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34124260

RESUMO

Objective: Acute respiratory distress syndrome (ARDS) is defined as the acute onset of noncardiogenic edema and subsequent gas-exchange impairment due to a severe inflammatory process known as cytokine storm. Xuebijing injection (hereinafter referred to as Xuebijing) is a patent drug that was used to treat ARDS or severe pneumonia (SP) in China. However, its efficacy and mechanism of actions remain unclear. In this study, we used meta-analysis and network pharmacology to assess these traits of Xuebijing. Methods: We searched PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI), and Wanfang databases for randomized controlled trials (RCTs) that evaluated Xuebijing therapy for ARDS or SP. The outcomes were total mortality, intensive care unit (ICU) stay time, and TNF-α and IL-6 levels. We performed a meta-analysis using RevMan 5.3 software. The putative targets, top 10 proteins, and possible pathway of Xuebinjing on ARDS were analyzed by network pharmacology. TNF-α and IL-6 were further docked with the six main active components of Xuebinjing using AutoDock 4.2.6 and PyMol 1.5.0.3 software. Results: Fifteen RCTs involving 2778 patients (13 ARDS and 2 SP) were included. Compared with the control, Xuebijing treatment significantly reduced the mortality rate (risk ratio, 0.64 (95% credible interval (CrI), 0.54-0.77)), reduced the ICU stay time (mean difference (MD), -4.51 (95% CrI, -4.97--4.06)), reduced the TNF-α ((MD), -1.23 (95% CrI, -1.38--1.08)) and IL-6 ((MD), -1.15 (95% CrI, -1.52--0.78)) levels. The 56 putative targets, top 10 proteins (MAPK1 (mitogen-activated protein kinase 1), MAPK8 (mitogen-activated protein kinase 8), RELA (transcription factor p65), NFKB1 (nuclear factor NF-kappa-B p105 subunit), JUN (transcription factor AP-1), SRC (proto-oncogene tyrosine-protein kinase), TNF (tumor necrosis factor), HRAS (GTPase HRas), IL6 (interleukin-6), and APP (amyloid-beta A4 protein)), and possible pathways (Ret tyrosine kinase, IL2-mediated signaling events, CD4+/CD8+ T cell-related TCR signaling, p75(NTR)-mediated signaling, CXCR4-mediated signaling events, LPA receptor-mediated events, IL12-mediated signaling events, FAS (CD95) signaling pathway, and immune system) of Xuebinjing's action on ARDS were obtained. The molecular docking results showed that all the six components of Xuebinjing docked with TNF-α, and two components docked with IL-6 got the binding energies lower than -5. Conclusion: Our results recommended Xuebijing treatment for patients with ARDS. Xuebijing has therapeutic effects on ARDS patients partly by regulating the immune cell/cytokine pathways and thus inhibiting the cytokine storm. TNF-α is the cytokine both directly and indirectly inhibited by Xuebijing, and IL-6 is the cytokine mainly indirectly inhibited by Xuebijing.


Assuntos
Medicamentos de Ervas Chinesas/uso terapêutico , Regulação da Expressão Gênica/efeitos dos fármacos , Síndrome do Desconforto Respiratório , Transdução de Sinais/efeitos dos fármacos , Medicamentos de Ervas Chinesas/química , Humanos , Unidades de Terapia Intensiva , Síndrome do Desconforto Respiratório/tratamento farmacológico , Síndrome do Desconforto Respiratório/genética , Síndrome do Desconforto Respiratório/metabolismo
20.
Front Cell Dev Biol ; 9: 659941, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34178986

RESUMO

Retinal blood vessel morphological abnormalities are generally associated with cardiovascular, cerebrovascular, and systemic diseases, automatic artery/vein (A/V) classification is particularly important for medical image analysis and clinical decision making. However, the current method still has some limitations in A/V classification, especially the blood vessel edge and end error problems caused by the single scale and the blurred boundary of the A/V. To alleviate these problems, in this work, we propose a vessel-constraint network (VC-Net) that utilizes the information of vessel distribution and edge to enhance A/V classification, which is a high-precision A/V classification model based on data fusion. Particularly, the VC-Net introduces a vessel-constraint (VC) module that combines local and global vessel information to generate a weight map to constrain the A/V features, which suppresses the background-prone features and enhances the edge and end features of blood vessels. In addition, the VC-Net employs a multiscale feature (MSF) module to extract blood vessel information with different scales to improve the feature extraction capability and robustness of the model. And the VC-Net can get vessel segmentation results simultaneously. The proposed method is tested on publicly available fundus image datasets with different scales, namely, DRIVE, LES, and HRF, and validated on two newly created multicenter datasets: Tongren and Kailuan. We achieve a balance accuracy of 0.9554 and F1 scores of 0.7616 and 0.7971 for the arteries and veins, respectively, on the DRIVE dataset. The experimental results prove that the proposed model achieves competitive performance in A/V classification and vessel segmentation tasks compared with state-of-the-art methods. Finally, we test the Kailuan dataset with other trained fusion datasets, the results also show good robustness. To promote research in this area, the Tongren dataset and source code will be made publicly available. The dataset and code will be made available at https://github.com/huawang123/VC-Net.

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