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1.
Materials (Basel) ; 14(17)2021 Sep 03.
Article in English | MEDLINE | ID: mdl-34501152

ABSTRACT

In this paper, the effects of an aging treatment on the corrosion resistance/mechanism of a tensile deformed Al-Cu-Mn-Fe-Zr alloy are investigated. The impedance magnitude and polarization resistance increase, while the corrosion current decreases with the increased aging time and temperature. The discontinuously-distributed precipitates and precipitation-free zone, which can cut the corrosion channels, appear at grain boundaries when the temperature is relatively high and the aging time is relatively long. They can improve the corrosion resistance. Additionally, the intergranular and pitting corrosion are the main mechanisms. The intergranular corrosion is likely to occur in an under-aged alloy. This is because the potential difference between the grain boundaries and grains is high, due to the segregation of Cu atoms. When the aging degree is increased, the grain boundary precipitates reduce the potential difference, and the intragranular precipitates make the surrounding matrix prone to dissolution. As such, the pitting corrosion is likely to occur in the over-aged alloys.

2.
J Cell Mol Med ; 24(20): 12094-12106, 2020 10.
Article in English | MEDLINE | ID: mdl-32916774

ABSTRACT

Glioma is the most common primary malignant tumour in the brain; temozolomide (TMZ) is the most prevalent chemotherapeutic drug currently used to combat this cancer. We reported previously that the long intergenic non-protein coding RNA 470 (LINC00470) is a novel prognostic biomarker for glioma and promotes the tumour growth in an intracranial transplantation mouse model. However, the effects of LINC00470 on glioma cell proliferation, invasion and TMZ chemosensitivity, as well as its molecular mechanism, remain unclear. In this study, we found elevated expression levels of LINC00470 and MYC in glioma tissues and cells and decreased expression of microRNA-134 (miR-134). Functional studies have shown that LINC00470 promotes proliferation and invasion, and attenuates chemosensitivity of glioma cells, while miR-134 exerts the opposite effect. In the rescue experiments, the tumorigenic effect of LINC00470 was offset by miR-134. In the mechanism study, we found that LINC00470 was a competitive endogenous RNA (ceRNA) of miR-134 and that miR-134 can directly target MYC and negatively regulate its expression. Furthermore, MYC was positively correlated with ATP-binding cassette subfamily C member 1 (ABCC1) expression in glioma cells and MYC up-regulated ABCC1 expression. Further studies found that LINC00470 regulated MYC by sponging miR-134 to regulate the expression of ABCC1. We concluded that LINC00470 promoted the expression of MYC and ABCC1 by suppressing miR-134, thus promoting glioma cell proliferation and invasion, and attenuating TMZ chemosensitivity. Moreover, the LINC00470/miR-134/MYC/ABCC1 axis constitutes a potential therapeutic target.


Subject(s)
Glioma/genetics , Glioma/pathology , MicroRNAs/metabolism , Multidrug Resistance-Associated Proteins/metabolism , Proto-Oncogene Proteins c-myc/metabolism , RNA, Long Noncoding/metabolism , Base Sequence , Brain Neoplasms/drug therapy , Brain Neoplasms/genetics , Brain Neoplasms/pathology , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Proliferation/genetics , Gene Expression Regulation, Neoplastic/drug effects , Glioma/drug therapy , Humans , MicroRNAs/genetics , Neoplasm Invasiveness , RNA, Long Noncoding/genetics , Temozolomide/pharmacology , Temozolomide/therapeutic use , Up-Regulation/drug effects , Up-Regulation/genetics
3.
Front Oncol ; 10: 609056, 2020.
Article in English | MEDLINE | ID: mdl-33552981

ABSTRACT

BACKGROUND: Management of tentorial notch meningiomas (TNM) remains a challenge for neurosurgeons. We demonstrate the clinical characteristics and surgical experiences of TNM based on our cases according to a proposed further classification. METHODS: We retrospectively analyzed clinical and follow-up data in a consecutive series of 53 TNM patients who underwent microsurgical operation from 2011 to 2019 in our institution. The operations were performed using various approaches. Clinical history, preoperative and postoperative neurofunction, imaging results, and surgical outcomes were collected for further classification of TNM. RESULTS: All TNM cases were divided into anterior (T1), middle (T2), and posterior notch (T3). According to the direction of tumor extension and correlation with the neurovascular structures, detailed subtypes of anterior TNMs were identified as the central (T1a), posterior (T1b), and medial type (T1c). The middle TNMs were divided into the infratentorial (T2a), supratentorial (T2b), and supra-infratentorial type (T2c). The posterior TNMs were divided into superior (T3a), inferior (T3b), lateral (T3c), and straight sinus type (T3d) in reference to Bassiouni's classification. Total removal of the tumor was achieved in 46 cases, with five cases of subtotal and two cases of partial removal without any recorded deaths in our series. In total, five subtotal resected cases underwent gamma-knife treatment and achieved stable disease. Postoperative aggravation or new onset cranial nerve dysfunction occurred in some individual cases, with incidences ranging from 3.77 to 15.10% and improved preoperative neurological deficits ranging from 0 to 100%. CONCLUSION: Further, TNM classification based on the intracranial location, extension direction, relationship with brainstem, and neurovascular structures guides preoperative evaluation, rational surgical approach selection, and surgical strategy formulation. Taking microsurgery as the main body, a satisfactory outcome of TNM treatment can be achieved for complicated tumors by combining stereotactic radiotherapy. This study demonstrates the surgical outcomes and complications in detail. Further classification might be helpful for treatment decisions in the future.

4.
Cancer Manag Res ; 11: 3139-3152, 2019.
Article in English | MEDLINE | ID: mdl-31114356

ABSTRACT

Purpose: Gliomas are the most common primary malignant neoplasms of the central nervous system. Secreted phospholipases A2 (sPLA2s) are known to play an important role in various physiological processes, including bioactive lipid production, defense mechanisms, and cell signaling. However, their roles and clinical importance in gliomas remain unclear. Patients and methods: In this study, we analyzed the association between the expression of various sPLA2-encoding genes and the clinicopathology of gliomas, using the data of 1047 patients obtained from a public database. Immunohistochemical analysis of 82 glioma tissues was also carried out to assess the relationship between phospholipase A2 group V (PLA2G5) protein expression and the World Health Organization (WHO) glioma grades. Results: We found that high PLA2G5 gene expression was associated with unfavorable prognosis in both low-grade and high-grade gliomas. The immunohistochemistry of the 82 glioma tissues further confirmed that PLA2G5 protein expression was dependent on the WHO glioma grade. In addition, we found a correlation between PLA2G5 gene expression and both epithelial-mesenchymal transition and the isocitrate dehydrogenase 1 mutation status in these tumors. Conclusion: Our results indicate that PLA2G5 could be a potential biomarker for predicting poor prognosis in patients with gliomas.

5.
Zhonghua Wai Ke Za Zhi ; 54(5): 367-71, 2016 May 01.
Article in Chinese | MEDLINE | ID: mdl-27143207

ABSTRACT

OBJECTIVE: To investigate the indications of the pretemporal transcavernous approach for cavernous sinus tumors resection and design individually tailored surgery according to the extent of tumors and operation requirements. METHODS: A retrospective analysis of clinical data, surgical outcomes and complications in a series of 31 cases with cavernous sinus tumor operated via the individually tailored pretemporal transcavernous approach between May 2012 and September 2015 in Department of Neurosurgery, Xiangya Hospital, Central South University. There were 13 male and 18 female patients, aging from 17 to 67 years with a mean of (41±14) years. The patients included 18 cases of shwannomas, 4 cases of meningiomas, 3 cases of cavernous hemangiomas, 2 cases of invasive pituitary adenomas, 1 case of chordoma, 1 case of chondroma, 1 case of recurrent teratoma, 1 case of metastatic nasopharyngeal carcinoma. The first followed-up visit was on the 3(rd) month after surgery, and if tumor progression or recurrence was observed on MRI, the Gamma knife treatment was recommended, the patient was followed up every 6 months, otherwise the patient was followed up again 6 months later, then, every 12 months. RESULTS: Gross total removal of tumors was achieved in 22 cases of 31 patients (71.0%), containing 17 cases of shwannomas, 3 cases of hemangiomas, 1 case of chondroma, 1 case of teratoma; subtotal removal in 6 cases (19.3%), including 3 cases of meningiomas, 1 case of pituitary adenoma, 1 case of chordoma, 1 case of metastatic carcinoma; partial removal in 3 cases (9.7%), comprising 1 case of meningioma, 1 case of recurrent shwannoma, 1 case of recurrent pituitary adenoma. The symptoms of cranial never aggravated in 5 cases, the new postoperative cranial never palsy was observed in 7 cases. There was no surgical mortality, intracranial hematoma, intracranial infection and cerebrospinal fluid leakage cases, ect. Twenty-eight cases were followed up for more than 3 months (3 to 40 months), 1 case of chordoma had tumor progression; the nerve function was restored in 5 cases, among the 12 cases with postoperatively new occurred or deteriorated cranial nerve paralysis. CONCLUSIONS: The pretemporal transcavernous approach can be used to resect tumors limited in cavernous sinus or tumors simultaneously involving the cavernous sinus and its vicinity areas, it can be individually tailored based on the extent and exposure of the tumor. This approach can improve the surgical results in terms of high tumor resection rate, less complication, is an ideal approach for cavernous sinus tumor resection.


Subject(s)
Adenoma/surgery , Cavernous Sinus/pathology , Chordoma/surgery , Hemangioma/surgery , Meningioma/surgery , Pituitary Neoplasms/surgery , Adolescent , Adult , Aged , Cavernous Sinus/surgery , Female , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Neoplasm Recurrence, Local , Postoperative Period , Radiosurgery , Retrospective Studies , Young Adult
6.
Zhong Yao Cai ; 33(12): 1884-6, 2010 Dec.
Article in Chinese | MEDLINE | ID: mdl-21548366

ABSTRACT

OBJECTIVE: To study the chemical constituents of Phlomis younghusbandii. METHODS: Column chromatography was used in the isolation procedure. The structures of isolated compounds were elucidated by spectral data RESULTS: Eight compounds were isolated and their structures were identified as barlerin (1), sesamoside (2), phloyoside II (3), salidroside (4), shanzhiside methyl ester (5), acteoside (6), luteolin-7-O-glucoside (7), daucosterol (8). CONCLUSION: Compound 4 is firstly isolated from Phlomis genus. Compound 4 and 6 are obtained from this plant for the first time.


Subject(s)
Glucosides/isolation & purification , Iridoids/isolation & purification , Phenols/isolation & purification , Phlomis/chemistry , Plants, Medicinal/chemistry , Flavones/chemistry , Flavones/isolation & purification , Glucosides/chemistry , Iridoids/chemistry , Magnetic Resonance Spectroscopy , Molecular Structure , Phenols/chemistry , Plant Roots/chemistry , Pyrans/chemistry , Pyrans/isolation & purification
7.
Guang Pu Xue Yu Guang Pu Fen Xi ; 27(6): 1093-7, 2007 Jun.
Article in Chinese | MEDLINE | ID: mdl-17763765

ABSTRACT

The newest development of applications of IR techniques to the identification of Chinese herbs, the discrimination of folk medicine herbs, Chinese herbs processing and Chinese traditional injection, which involving enhancing computer analysis depth, intensifying the pre-treatment of Chinese herb and using 2D-IR correlation spectroscopy for processing control, was elaborated in the present paper. Meanwhile, the establishment of multi-component determination analysis system of chromatographic fingerprint diagram was shown. And the sameness and difference of the IR spectroscopy and chromatography fingerprint diagram techniques were analyzed, and a comparison was made in terms of quality control of Chinese herbal medicine.

8.
J Org Chem ; 68(14): 5568-74, 2003 Jul 11.
Article in English | MEDLINE | ID: mdl-12839448

ABSTRACT

A convergent and modular synthesis has been devised to construct the eight diastereoisomers of deoxyfusapyrone (1). In this paper the synthesis of the complex polyene chain is reported as is its connection to the pyrone moiety that is in the middle of the structure of the final target molecule. This route has been fully worked out for one of the isomers and will now be applied in a parallel synthesis format to make all the stereoisomers of 1.


Subject(s)
Antifungal Agents/chemical synthesis , Pyrones/chemical synthesis , Alkenes/chemistry , Fusarium/chemistry , Fusarium/metabolism , Pyrones/chemistry , Stereoisomerism
9.
J Org Chem ; 67(22): 7847-51, 2002 Nov 01.
Article in English | MEDLINE | ID: mdl-12398512

ABSTRACT

An effective synthesis of the C1-C10 component of deoxyfusapyrone has been achieved that will allow for the synthesis of both the (R) and (S) form of the C-8 chiral center starting from optically pure (+)- and (-)-3,3-dimethyl-2-hydroxy-gammalactone (pantolactone).


Subject(s)
Pyrones/chemistry , Pyrones/chemical synthesis , Cyclization , Decarboxylation , Molecular Structure , Stereoisomerism
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