Two novel polyoxovanadate-based metal-organic frameworks (MOFs), Co(bib){V
2
O
6
} (V-Co-MOF) and Ni(en)(bib){V
2
O
6
}·2H
2
O (V-Ni-MOF) (bib = 1,4-bis(1
H
-imidazoly-1-yl)benzene, en = ...ethylenediamine) were facilely synthesized under mild hydrothermal conditions. Single-crystal X-ray diffraction analysis shows that the V sites in both compounds adopt {VO
4
} tetrahedral coordination geometries, and the Co center in the V-Co-MOF presents a four-coordinated distorted tetrahedron configuration (coordinatively unsaturated metal sites, CUMS), while the Ni center in the V-Ni-MOF exhibits six-coordinated octahedral geometry (coordinatively saturated metal sites, CSMS). Given that the CUMS can generally be used as active sites for catalytic reactions, we explored the catalytic activities of these two compounds for the oxidation of a mustard gas simulant, 2-chloroethyl ethyl sulfide (CEES). The experimental results indicate that they can catalyze the oxidation of CEES to give the only nontoxic product, 2-chloroethyl ethyl sulfoxide (CEESO). Significantly, the V-Co-MOF exhibits higher catalytic activity; it converts 100% of CEES in 10 min, whereas V-Ni-MOF converts only 47.5% of CEES under identical conditions. Researching the mechanism of the catalytic reaction revealed that the excellent catalytic performance of the V-Co-MOF was attributed to the two-site synergetic effect: (1) the oxidant H
2
O
2
interacts with the V site to produce peroxovanadium with higher oxidation activity; (2) the S atom in CEES coordinates with the four-coordinated Co(
ii
) center to obtain 2-chloroethyl ethyl sulfonium cation (CEES+), which makes the CEES more easily oxidize to CEESO based on the oxidation mechanism of peroxovanadium and shortens the molecular size distance between CEES and the obtained peroxovanadium, thereby greatly improving the rate of the catalytic reaction. To our knowledge, this is the first dual-active-site polyoxometalate-based MOF catalyst for catalysing the oxidative detoxification of CEES.
A polyoxovanadate-based cobalt organic framework (V-Co-MOF) was synthesized and it, as a heterogeneous catalyst, can catalyze the rapid selective oxidation of a mustard gas simulant to a non-toxic product by the two-site synergistic effect of V
V
and Co
II
.
The selective oxidation of C-H bonds of benzylic compounds to synthesize high-value-added ketones remains a challenge under mild conditions, and the ambiguity of its oxidation mechanism limits the ...further development of this field. In this work, we construct a polyoxometalate-based metal-organic framework (POMOF), Cu
I
2
Cu
II
(bix)
2
{V
4
O
12
} (
1
, bix = 1,4-bis(imidazole-1-ylmethyl)benzene), successfully achieving the efficient oxidation catalysis of various benzylic compounds with outstanding conversion, selectivity and durability under mild conditions. Our experimental studies suggest that the highly catalytic activity of
1
derives from its attractive structure with multiple active sites, which consists of V
V
centers in a unique U-type {V
4
O
12
}
4−
({V
4
}) cluster and Cu
I
and Cu
II
centers bridged to the {V
4
} cluster. Importantly, further theoretical calculations indicate that there exists synergistic catalysis between Cu
I
/{V
4
} sites and Cu
II
/{V
4
} sites for
1
as catalyst in the oxidation of benzylic compounds, where the {V
4
} cluster mainly provides deprotonation and oxidation sites, and the Cu
I
site plays a role in the reduction of the oxidant, while the Cu
II
site plays a role in the adsorption of the oxidant. This is the first POMOF whose catalytic mechanism towards the oxidation of benzylic C-H bonds is deeply studied through the combination of experiments and theoretical calculations, providing a new perspective for the design of related catalysts.
Multi-active site synergy in a polyoxovanadate-based mixed-valence copper metal-organic framework for efficient catalysis of C-H bond oxidation of benzylic compounds.
A novel mixed-valence polyoxovanadate-based copper–organic framework, Cu I (bbi) 2 {Cu I (bbi) 2 VIV2V V 8 O 26 }·2H 2 O (NENU-MV-5, bbi = 1,1′-(1,4-butanediyl)bis(imidazole)), was facilely ...synthesized from routine reagents under mild hydrothermal conditions. Using NENU-MV-5 as a heterogeneous catalyst without any co-catalyst, one-step oxidative cleavage of β-O-4 lignin into phenols and aromatic acids with high catalytic activity and selectivity was realized under an oxygen atmosphere. No obvious decrease in activity was observed after five cycles, which indicates the excellent stability and sustainability of NENU-MV-5. The perfect catalytic performance of NENU-MV-5 can be attributed to the multi-site synergistic effect of the mixed-valence V V –O–V IV sites on polyoxovanadate for the oxidation of β-O-4 alcohol to β-O-4 ketone and the Cu( i ) sites on the framework for the rapid cleavage of the C α –C β bond of β-O-4 ketone. This system represented the first co-catalyst-free example for the one-step selective degradation of lignin catalyzed by a well-defined crystalline catalyst with definite composition and structure in a single solvent.
A polyoxovanadate-based nickel–organic framework, Ni(bib)2{V2O6}({V6}-MOF, bib = 1,4-bis(1H-imidazoly-1-yl)benzene), was facilely prepared under gentle hydrothermal conditions and structurally ...characterized. Single-crystal X-ray diffraction analysis indicates that the {V6} cluster in the {V6}-MOF is constructed of two VO5 tetragonal pyramids and four VO4 tetrahedrons via the apex sharing of O atoms, presenting a hollow Linqvist-like structure, which is different from these reported hexanuclear vanadium clusters. The {V6}-MOF not only expands the structure of polyoxovanadates (POVs) but also catalyzes the rapid detoxification of mustard gas simulant (2-chloroethyl ethyl sulfide, CEES) at 25 °C. The catalytic results were determined by means of GC, GC–MS, and 1H NMR. Using {V6}-MOF as a heterogeneous catalyst, CEES underwent catalyzed oxidation to only nontoxic product 2-chloroethyl ethyl sulfoxide (CEESO) within 40 min, and the conversion and selectivity were almost 100%. In addition, {V6}-MOF exhibits high sustainability, and no obvious reductions in conversion and selectivity are observed after five runs.
A pure-inorganic framework based on {P
4
Mo
V
4
Mo
VI
2
} clusters with rich phosphate groups has been synthesized. It underwent a single crystal to single crystal conversion in air to form a new ...framework with changes both in the metal valent state and coordination environment. The new framework exhibits an ultra-high proton conductivity of 1.33 × 10
−2
S cm
−1
at 95 °C and 98% relative humidity and excellent stability.
A pure-inorganic framework
1
underwent a SCSC transformation to form a new framework
1′
, which has high proton conductivity.
Deregulation of microtubules and centrosome integrity is response for the initiation and progression of human cancers. Sperm-associated antigen 5 (SPAG5) is essential for the spindle apparatus ...organization and chromosome segregation, but its role in hepatocellular carcinoma (HCC) remains undefined.
The expression of SPAG5 in HCC were examined in a large cohort of patients by RT-PCR, western blot and IHC. The clinical significance of SPAG5 was next determined by statistical analyses. The biological function of SPAG5 in HCC and the underlying mechanisms were investigated, using in vitro and in vivo models.
Here, we demonstrated that SPAG5 exhibited pro-HCC activities via the activation of PI3K/AKT signaling pathway. SPAG5 expression was increased in HCC and correlated with poor outcomes in two independent cohorts containing 670 patients. High SPAG5 expression was associated with poor tumor differentiation, larger tumor size, advanced TNM stage, tumor vascular invasion and lymph node metastasis. In vitro and in vivo data showed that SPAG5 overexpression promoted tumor growth and metastasis, whereas SPAG5 knockdown led to the opposite phenotypes. SPAG5 interacted with centrosomal protein CEP55 to trigger the phosphorylation of AKT at Ser473. Inhibition of PI3K/AKT signaling markedly attenuated SPAG5-mediated cell growth. Furthermore, SPAG5 expression was suppressed by miR-363-3p which inhibited the activity of SPAG5 mRNA 3'UTR. Ectopic expression of SPAG5 partly abolished the miR-363-3p-caused cell cycle arrest and suppression of cell proliferation and migration.
Collectively, these findings indicate that SPAG5 serves a promising prognostic factor in HCC and functions as an oncogene via CEP55-mediated PI3K/AKT pathway. The newly identified miR-363-3p/SPAG5/CEP55 axis may represent a potential therapeutic target for the clinical intervention of HCC.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Objective
NF1 is a tumor suppressor gene that encodes the neurofibromin protein and negatively regulates Ras signaling. This study was aimed to investigate the molecular, clinical characteristics, ...and prognostic features of NF1 gene in EGFR mutant lung cancer patients.
Method
The next‐generation sequencing (NGS) was used to analyze the data from lung cancer patients in the Guangdong Lung Cancer Institute (GLCI) from June 2016 to December 2020.
Results
Somatic NF1 mutations were present in 4.2% (135/3220) of Chinese lung cancer patients. NF1 mutations where clearly enriched in older (p < 0.001), male (p < 0.001), and smoking (p < 0.001) patients. Patients with NF1 mutations were more likely to have TP53 (p = 0.003), BRAF (p = 0.001) and RASA1 (p = 0.026) mutations and mutually exclusive with EGFR mutations (p = 0.006). TP53 mutation had worsen prognosis in cases of NF1 mutant (p = 0.026) or EGFR/NF1 co‐mutant (p = 0.031) lung adenocarcinomas (LUAD) patients. There was no effect on overall survival (OS) in LUAD patients with and without NF1 mutations, even in LUAD driver‐gene negative patients. NF1/EGFR co‐mutation patients had a longer OS than a single mutation of either the EGFR gene (median OS: 47.7 m vs. 30.2 m, hazard ratio 95% CI, 0.47 0.30–0.74, p = 0.004) or NF1 gene (47.7 m vs. 19.0 m, 0.44 0.27–0.73, p = 0.003). Furthermore, NF1 mutations significantly prolonged OS in EGFR mutant/TP53 wild‐type LUAD patients (106.5 m vs. 25.5 m, 0.28 0.13–0.59, p = 0.003) but not in patients with EGFR/TP53 co‐mutations (36.8 m vs. 30.2 m, 0.70 0.39–1.26, p = 0.280).
Conclusion
Our results indicated NF1 mutations served as a good prognostic factor in EGFR mutant/TP53 wild‐type lung cancer patients in this single‐center study. TP53 mutation was obviously enriched in NF1 mutant patients and had shorter OS.
This was the largest sample size analysis for NF1 gene in East Asia lung cancer patients. NF1 mutant tumors could define a specific population with a distinct clinical and molecular profiles. Our results showed for the first time that NF1 mutations significantly prolonged overall survival in EGFR mutant/TP53 wild‐type lung adenocarcinoma (LUAD) patients and served as a good prognostic factor. TP53 mutations were clearly enriched in the NF1 mutant lung cancer patients, and had worsen prognosis in cases of NF1 mutant or EGFR/NF1 co‐mutant LUAD patients.
Background
The optimal surgical management of patients with incidental gallbladder cancer (IGBC) and their long-term survival remains unclear.
Objective
The purpose of this study was to examine the ...long-term prognosis of patients with IGBC diagnosed during or after LC.
Methods
Between January 2002 and January 2012, a total of 7,582 consecutive patients underwent LC for presumed gallbladder benign disease in the Chinese PLA General Hospital, China. Among them, 69 patients (0.91 %) were diagnosed to have IGBC. Their medical records, imaging data, surgery records, pathological findings, and survival data were retrospectively reviewed.
Results
Median age was 61 years (range: 34–83). After a median follow-up period of 61 months, the 1-, 3-, and 5-year survival rates of patients were 89.9, 78.3, and 76.8 %, respectively. The 5-year survival rates of patients with T1a, T1b, T2, and T3 stages were 95.5, 93.8, 69.2, and 44.4 %, respectively. The 5-year survival rates in simple LC (
n
= 45), converted to open extended cholecystectomy (
n
= 16), and radical second resection (
n
= 8) groups were 91.1, 37.5, and 75.0 %, respectively. Local port-site tumor recurrence was identified in one patient. Prognostic factors including depth of invasion, lymph node status, vascular or neural invasion, tumor differentiation, extent of resection, bile spillage, and type of surgery were statistically significant (
p
< 0.05).
Conclusions
Simple LC is appropriate for T1a patients with clear margin and unbroken gallbladder, whereas extended radical resection is recommended for patients with T1b or more advanced IGBC. An intact surgical specimen and the use of plastic retrieval bags are important to reduce the risk of port-site recurrences and disease relapse. Early diagnosis, meticulous perioperative assessment, and precise surgery are essential factors to obtain good results in IGBC treatment.
An effective method to eliminate grain boundary resistance of crystalline vanadoborate electrolyte was developed. This method involved the addition of glycerol to result in the formation of many ...hydrogen bonds between crystal grains, facilitating a rapid transfer of protons across grain boundaries. Using this method, the intrinsic conduction of vanadoborate electrolyte was fully reflected in its bulk materials, valuable for advancing our understanding of vanadoborate electrolytes and for promoting the application of these electrolytes.
Mitochondria play a kay role in various cell processes including ATP production, Ca^2＋ homeostasis, reactive oxygen species （ROS） generation, and apoptosis. The selective removal of impaired ...mitochondria by autophagosome is known as mitophagy. Cerebral ischemia is a common form of stroke caused by insuf- ficient blood supply to the brain. Emerging evidence suggests that mitophagy plays important roles in the pathophysiological process of cerebral ischemia. This review focuses on the relationship between ischemic brain injury and mitophagy. Based on the latest research, it describes how the signaling pathways of mitophagy appear to be involved in cerebral ischemia.
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