RESUMO
Designing nanocomposite hydrogels with oriented nanosheets has emerged as a promising toolkit to achieve preferential performances that go beyond their disordered counterparts. Although current fabrication strategies via electric/magnetic force fields have made remarkable achievements, they necessitate special properties of nanosheets and suffer from an inferior orientation degree of nanosheets. Herein, a facile and universal approach is discovered to elaborate MXene-based nanocomposite hydrogels with highly oriented, heterogeneous architecture by virtue of supergravity to replace conventional force fields. The key to such architecture is to leverage bidirectional, force-tunable attributes of supergravity containing coupled orthogonal shear and centrifugal force field for steering high-efficient movement, pre-orientation, and stacking of MXene nanosheets in the bottom. Such a synergetic effect allows for yielding heterogeneous nanocomposite hydrogels with a high-orientation MXene-rich layer (orientation degree, f = 0.83) and a polymer-rich layer. The authors demonstrate that MXene-based nanocomposite hydrogels leverage their high-orientation, heterogeneous architecture to deliver an extraordinary electromagnetic interference shielding effectiveness of 55.2 dB at 12.4 GHz yet using a super-low MXene of 0.3 wt%, surpassing most hydrogels-based electromagnetic shielding materials. This versatile supergravity-steered strategy can be further extended to arbitrary nanosheets including MoS2, GO, and C3N4, offering a paradigm in the development of oriented nanocomposites.
RESUMO
OBJECTIVE: To investigate the expression of matrix metal proteinase (MMP)-2 and MMP-9 in adenoid cystic carcinoma of lacrimal gland as well as their relation with biological behaviour of adenoid cystic carcinoma. METHODS: Experimental study. The research objects were 60 cases of adenoid cystic carcinoma of lacrimal gland which were collected from No.2 Hospital of Tianjin Medical University from January 1991 to Jule 2011. There were 25 males and 35 females aged from 29 to 42 years. Based on histological revision, there were 36 cases of cribriform-tubular subtype and 24 cases of solid subtype. Forty-five cases were primary lesions and 15 cases were recurrent lesions. Ten samples of normal lacrimal gland around polymorphic adenoma were selected as the control group. The expression of CD105, MMP-2 and MMP-9 were evaluated by immunohistochemistry. The microvessel density (MVD) was defined by expression of CD105. One way ANOVA, χ(2)-test and spearman correlation test were used to analyzed the data. RESULTS: The number of MVD [(17.71 ± 5.63)/100 folds field of vision] and the positive rates of MMP-2 (45.0%, 27/60) and MMP-9 (55.0%, 33/60) in the samples of adenoid cystic carcinoma of lacrimal gland were higher than those in the normal lacrimal gland [the number of MVD was (0.70 ± 0.95)/100 folds field of vision, the expressions of MMP-2 and MMP-9 were negative] (t' = 2.039, P < 0.05; χ(2) = 5.550, P < 0.05; χ(2) = 8.315, P < 0.01), the solid subtypes had more MVD [(26.12 ± 5.32)/100 folds field of vision] and higher positive rates of MMP-2 (62.5%, 15/24) and MMP-9 (79.2%, 19/24) than the cribriform-tubular subtypes (t' = 2.060, P < 0.05; χ(2) = 4.950, P < 0.05; χ(2) = 9.439, P < 0.05); the recurrent lesions had more MVD and higher positive rate of MMP-2 and MMP-9 than the primary lesions (t' = 2.129, P < 0.05; χ(2) = 9.899, P < 0.05; χ(2) = 8.103, P < 0.05). The number of MVD in ACC of lacrimal gland patients was correlated with the positive rate of MMP-2 and MMP-9 respectively (rs = 0.636, P < 0.05; rs = 0.524, P < 0.05). CONCLUSIONS: The number of MVD and the expression of MMP-2 and MMP-9 are higher level in adenoid cystic carcinoma of lacrimal gland and are significantly correlated with pathological type and recurrence. Detecting the number of MVD and the expression of MMP-2 and MMP-9 may become biological indexes for malignancy, recurrence and metastasis of adenoid cystic carcinoma of lacrimal gland.
