Folate deficiency promotes cervical squamous carcinoma SiHa cells progression by targeting miR-375/FZD4/ß-catenin signaling.

Epidemiological studies suggest an association between folate deficiency (FD) and cervical squamous cell carcinoma (SCC) progression. However, the underlying mechanism is unclear. Our study showed that FD-driven downregulation of miR-375 promoted proliferation of SCC SiHa cells and progression of xenograft tumors developed from SiHa; however, the exact mechanism of this process remained unclear. The current study aimed to elucidate the underlying mechanisms by which FD promotes the progression of SiHa cells by downregulating miR-375 expression. The results showed that miR-375 acted as a suppressor of SCC and inhibited the proliferation, migration, and invasion of SiHa cells. The FZD4 gene was identified as a target gene of miR-375, which can reverse the anti-onco effect of miR-375 and promote the proliferation and migration of SiHa cells. Furthermore, the regulatory effects of miR-375 and FZD4 on SiHa cells may be achieved by activating the ß-catenin signaling pathway. Moreover, FD may regulate the expression of miR-375 by regulating its DNA methylation level in the promoter region. In conclusion, our study reveals that FD regulates the miR-375/FZD4 axis by increasing the methylation of the miR-375 promoter, thereby activating ß-catenin signaling to promote SiHa cells progression. This study may provide new insights into the role of folic acid in the prevention and treatment of SCC.

Impact of HR-HPV infection on oncological outcomes in early cervical cancer.

Background: This study aimed to investigate the differences in long-term oncological outcomes between high-risk human papillomavirus (HR-HPV) negative and HR-HPV positive early-stage cervical cancers. Methods: We retrospectively analysed 2061 cases of early-stage cervical cancer from the Chinese cervical cancer clinical diagnosis and treatment database. Kaplan-Meier curves were used to describe the survival outcomes of different HR-HPV infections. Cox proportional hazard regression model was used to analyze and determine independent risk factors. Results: K-M analysis revealed no significant difference in 5-year OS between HR-HPV negative and HR-HPV positive groups (OS: 95.0% vs.95.6%, P=0.900). A significant difference was observed in 5-year DFS between the HR-HPV negative and HR-HPV positive groups (DFS: 87.2% vs.91.9%, P=0.025). Cox proportional hazard regression model indicated that HR-HPV infection (negative vs. positive) was an independent factor influencing 5-year DFS after early cervical cancer surgery (DFS: hazard ratio [HR]=1.862, P=0.022). HR-HPV infection (negative vs positive) was not an independent factor influencing 5-year OS after early cervical cancer surgery (OS: P=0.813). After 1:1 PSM pairing, there was no significant difference in 5-year OS and DFS between HR-HPV negative group and HR-HPV positive group (OS: 91.6% vs.95.0%, P=0.297; DFS: 87.2% vs.85.1%, P=0.758). Cox multivariate analysis indicated that HR-HPV infection was not an independent factor influencing 5-year OS and DFS after early cervical cancer surgery (OS: P=0.806, DFS: P=0.251). Conclusions: The tumour results of HR-HPV negative group and HR-HPV positive group were similar, after eliminating the differences in known variables that affect the oncological outcomes of cervical cancer. The treatment plan of HR-HPV positive cervical cancer is suitable for HR-HPV negative cervical cancer.

Interactions between vaginal local cytokine IL-2 and high-risk human papillomavirus infection with cervical intraepithelial neoplasia in a Chinese population-based study.

Background: Although interleukin-2 (IL-2) has long been associated with cancer development, its roles in the development of cervical cancer remains unclear. Few studies examined the associations between IL-2 and high-risk human papillomavirus (HPV) with risk of cervical intraepithelial neoplasia (CIN). Objective: We aimed to assess the association of IL-2 and high-risk HPV infection with risk of CIN as well as their interactions on the risk of CIN. Design: We performed a cross-sectional analysis of screening data in 2285 women aged 19-65 years who participated in an ongoing community-based cohort of 40,000 women in Shanxi, China in 2014-2015. Both categorical and spline analyses were used to evaluation the association between IL-2 in the local vaginal fluids and prevalence of CIN. In addition, 1503 controls were followed up until January 31, 2019), the nested case-control study design was adopted to evaluate the association of vaginal lavage IL-2 levels and the risk of CIN progression. Results: After adjusting for potential confounders, IL-2 levels were statistically inversely associated with prevalence of CIN (the 1st versus 4th quartile IL-2 levels: the respective odds ratio [OR] and 95% confidence intervals [CI] was: = 1.75 [1.37, 2.23] for CIN, 1.32 [1.01, 1.73] for CIN I, and 3.53 [2.26, 5.52] for CIN II/III). Increased IL-2 levels were inversely associated with prevalence of CIN (P-overall<0.01, P-nonlinearity<0.01 for CIN; P-overall<0.01, P-nonlinearity = 0.01 for CIN I; P-overall <0.01, P-nonlinearity = 0.62 for CIN II/III). The highest prevalence of CIN was observed in women with high-risk HPV, who also had the lowest IL-2 levels (P-interaction < 0.01). Nested case-control study observed an inverse association between IL-2 levels and risk of CIN progression (OR=3.43, [1.17, 10.03]). Conclusions: IL-2 levels in the local vaginal fluids were inversely associated with the risk of CIN in Chinese women either with or without high-risk HPV infection.

Associations of RBC and Serum Folate Concentrations with Cervical Intraepithelial Neoplasia and High-Risk Human Papillomavirus Genotypes in Female Chinese Adults.

BACKGROUND: Although folate status is associated with cervical carcinogenesis, it is not clear whether folate deficiency is associated with risk of cervical intraepithelial neoplasia (CIN) progression and infection with high-risk human-papillomavirus (hrHPV). OBJECTIVES: To evaluate the associations of RBC and serum folate concentrations with prevalence of CIN grades and hrHPV infection, their interactions with prevalence of CIN grades, and RBC folate with the risk of CIN1 progressing to CIN2. METHODS: Using data from the Shanxi CIN cohort of 2304 female Chinese adults, we used logistic-regression model to estimate ORs and prevalence ratios (PRs) of RBC and serum folate concentrations with prevalence of CIN grades and hrHPV infection. Categoric and spline analyses were used to evaluate the dose-response relations. We estimated the association of RBC folate with risk of CIN1 progressing to CIN2 in the nested case-control cohort. RESULTS: An inverse association was observed between increased RBC folate concentration and the odds of all CIN grades [quartile 1 (Q1) compared with Q4: OR: 2.28; 95% CI: 1.77, 2.93; Ptrend < 0.001]. Significant interaction of RBC folate and hrHPV infection was observed for prevalence of CIN2 or above (Pinteraction < 0.01). No associations were found between RBC and serum folate with PRs of hrHPV in each CIN grade. Over a median follow-up of 21.0 mo, RBC folate was associated with increased risk of CIN1 progressing to CIN2 (Q1 compared with Q4: OR: 3.86; 95% CI: 1.01, 14.76). CONCLUSIONS: Our study indicates that RBC folate concentration is associated with prevalence of CIN grades and CIN1 progression in female Chinese adults. Maintenance of normal folate status is important for reducing the risk of CIN and its progression in women with or without hrHPV infection.

Molecular dynamics study on structural and atomic evolution between Au and Ni nanoparticles through coalescence.

Motivated by the structure evolution experiments of Janus NiAu nanoparticles (NPs), we present a detailed study on the thermodynamic evolution of Ni and Au NPs with different ratios of Au and Ni through the molecular dynamics (MD) simulations. It is found that, for fixed Ni particle size (5.8 nm in diameter), the energy variation with the increasing temperature is related to the Au sizes (1.5-9.6 nm in diameter), due to the diverse atomic segregation modes. For a small Au particle, due to lattice induction, the structure will change from order to disorder and then to order. The interface defects of the merging NPs could be automatically eliminated by coalescence processes. The change in energy as the temperature increases is similar to that of monometallic NPs. For larger Au particles, the irregular variation of energy occurs and the atomic energy experience one or two reductions at least with the increase of the temperature. The segregation of Au atoms to the surface of Ni particle is dominant during the continuous heating process. The coalescence processes of Au atoms strongly determine the final morphology of the particles. Dumbbell-like, Janus and eccentric core-shell spherical structures could be obtained during the heating process. Our results will provide an effective approach to the design of novel materials with specific properties through thermal control.

Efficient combination of Human Papillomavirus Genotyping for the triage of women with Atypical Squamous Cells of Undetermined Significance in Chinese rural population: A population-based study.

Objective: In this prospective, population-based study, we evaluated the utility of high-risk human papillomavirus (HR-HPV) genotyping for triaging women with atypical squamous cells of undetermined significance (ASC-US) in the Chinese rural area. Methods: A total of 40,000 women were recruited from rural areas of Shanxi Province, China, between June 2014 and December 2014. Women with Pap results of ASC-US underwent HPV genotyping, colposcopy and histopathological examination. For those with normal cervixes or cervical intraepithelial neoplasia (CIN) 1 on the initial evaluation, a 2-year follow-up study was performed. Results: The reporting rate of ASC-US was 5.76% (2,304/40,000) in the study population. The detection rates of CIN 2 or above (CIN2+) and CIN 3 or above (CIN3+) in women with ASC-US were 7.28% and 1.75%, respectively. HPV 16 (39.53%), HPV 58 (17.83%), and HPV 52 (15.50%) were the three most prevalent HR-HPV genotypes among all women with ASC-US cytology. The five most common HR-HPV genotypes in CIN3+ lesions were HPV16, HPV58, HPV33, HPV31 and HPV18. Compared with the 15 HR-HPV testing, genotyping for a combination of HPV16/18/31/33/58 increased specificity significantly with virtually no loss of sensitivity for detecting CIN2+ and CIN3+ lesions, as well as significantly reduced colposcopy referral rate (23.15% vs 33.70%, p<0.01). In addition, in the 2-year follow-up period, women with infection of HPV16, 18, 31, 33 or 58 genotypes were the most likely population (92%, 23/25) to develop CIN2 lesion. Conclusion: Our results demonstrate that genotyping for a combination of HPV16/18/31/33/58 provides a more efficient and cost-effective model to risk-stratify women with ASC-US in the Chinese rural population.

Intrinsic in-plane nodal chain and generalized quaternion charge protected nodal link in photonics.

Nodal lines are degeneracies formed by crossing bands in three-dimensional momentum space. Interestingly, these degenerate lines can chain together via touching points and manifest as nodal chains. These nodal chains are usually embedded in two orthogonal planes and protected by the corresponding mirror symmetries. Here, we propose and demonstrate an in-plane nodal chain in photonics, where all chained nodal lines coexist in a single mirror plane instead of two orthogonal ones. The chain point is stabilized by the intrinsic symmetry that is specific to electromagnetic waves at the Г point of zero frequency. By adding another mirror plane, we find a nodal ring that is constructed by two higher bands and links with the in-plane nodal chain. The nodal link in momentum space exhibits non-Abelian characteristics on a C2T - invariant plane, where admissible transitions of the nodal link structure are determined by generalized quaternion charges. Through near-field scanning measurements of bi-anisotropic metamaterials, we experimentally mapped out the in-plane nodal chain and nodal link in such systems.

Lower dietary mineral intake is significantly associated with cervical cancer risk in a population-based cross-sectional study.

Population-based studies investigating the association between dietary mineral intake and risk of cervical intraepithelial neoplasia (CIN) or cervical cancer in Chinese women are few. We performed a cross-sectional analysis of screening data obtained from 2,304 women in 2014 within an ongoing cohort study comprising 40,000 women in China. Dietary intake was assessed using a semiquantitative food frequency questionnaire. Nutrition intake was calculated using a 26-item list of food sources drawn from a validated, comprehensive database. All participants were surveyed through in-person interviews, physical examinations, and laboratory tests. The Pearson chi-square test was used for categorical variables. Multivariable logistic regression models were used to evaluate the relationship between dietary mineral intake and CIN+ risk. The food frequency questionnaire exhibited acceptable reproducibility and reasonable validity in assessing nutrient intakes among these women. After adjusting for multiple potential confounders, low dietary calcium intake was associated with CIN2+ risk (first versus fourth quartile: odds ratio [OR]=1.52, 95% confidence interval [CI]: 1.01-2.32). Similar for magnesium (OR=1.80, 95% CI: 1.20-2.68), phosphorus (OR=1.69, 95% CI: 1.12-2.55), zinc (OR=1.55, 95% CI: 1.03-2.34), and potassium (OR=1.92, 95% CI: 1.28-2.88). Low dietary intakes of calcium and potassium were significantly associated with CIN1 risk. Increased CIN2+ risk correlated with rates of no oral contraceptives and lower levels of dietary Potassium. These results thus proposed that low dietary mineral intake was an independent risk factor, potential synergy may exist between low dietary mineral levels and oral contraceptives contribute to the development of higher-grade CIN and cervical cancer.

Long non-coding RNA LINC00525 interacts with miR-31-5p and miR-125a-5p to act as an oncogenic molecule in spinal chordoma.

LINC00525 is a new-researched long non-coding RNA (lncRNA) in a few cancers. This study aims at researching the function of LINC00525 in spinal chordoma and the underlying mechanism of action. LINC00525, microRNA-31-5p (miR-31-5p) and microRNA-125a-5p (miR-125a-5p) detection was performed by quantitative real-time polymerase chain reaction (qRT-PCR). We found the high expression of LINC00525 but the low levels of miR-31-5p and miR-125a-5p in spinal chordoma tissues. After LINC00525 was downregulated in spinal chordoma cells, there were inhibitory effects on cell proliferation, migration, invasion and EMT but a promoting effect on cell apoptosis. MiR-31-5p and miR-125a-5p were the downstream targets of LINC00525. The function of LINC00525 knockdown in spinal chordoma cells were achieved by upregulating miR-31-5p and miR-125a-5p. Tumorigenesis of spinal chordoma in vivo was also inhibited by knockdown of LINC00525 via the promotion of miR-31-5p and miR-125a-5p. All these results suggested that LINC00525 targeted miR-31-5p and miR-125a-5p to promote the tumorigenesis and progression of spinal chordoma. LINC00525 can be a novel molecular target in spinal chordoma.

Diagnostic Yield and Performance of a Large Population-Based Cervical Cancer Screening Program in High-Risk Rural China.

Primary cervical cancer screening by liquid-based cytology alone or with adjunctive HPV testing are available worldwide. However, little if any information is available about cervical cancer diagnostic yield of population-based cervical cancer screening in China. In response to it, we conducted a large prospective study on 40,000 women cervical cancer screening within six-month period in rural Shanxi Province, where has been reported as the highest cervical cancer rates in China. A standard cross-sectional survey by self-completed questionnaire was collected and followed by the liquid-based cytology screening. Follow-up biopsy with the diagnosis of cervical intraepithelial neoplasia 2 or higher lesion (CIN2+) were analyzed. Of initial 40,000 women participating in this study, 6.76% (2702/40,000) women had ASC-US or higher cytology screening results with ASC/SIL ratio at 6.14 (2381:388). Among them, 1.96% (782/40,000) women were found CIN lesions (95% CI, 1.68-2.23%) on confirmatory biopsies, including 0.55% (218/40,000) CIN2+ and 19 SCCa (47.5/100,000, 95% CI, 29-74/100,000). Women in Yangqu County had lower ASC/SIL ratio, but higher CIN2+ detection rate in comparison with that of Jiexiu County (6.69 vs. 8.84 and 56.7% vs. 43.9%), which reflects the cervical cancer distribution in different populations and regions. Analysis in age-stratified cytology results indicated women aged 60-65 years had the highest incidence of cytologic abnormality among all the age group; likewise, women aged >50 years were at higher risk in developing cervical high grade dysplasia or cancer than women aged <50 years (0.82% vs. 0.49%). This large-scale cervical cancer screening study provided important references as the instructive for establishing the nation-wide cervical cancer screening strategy.

Oral treatment with glycyrrhizin inhibits NLRP3 inflammasome activation and promotes microglial M2 polarization after traumatic spinal cord injury.

The inflammatory response induced by traumatic spinal cord injury (SCI) involves the activation of NLRP3 inflammasomes, which are closely related to the activation of microglia. Microglial polarization between M1/M2 phenotypes is a pivotal regulatory factor in neuroinflammatory responses to traumatic SCI-induced secondary injuries, and altering this polarization could be beneficial. Glycyrrhizin is a neuroprotective agent with a potent anti-inflammatory property in different neurological disorders and could potentially be useful in SCI. In this study, we investigated the potency of oral treatment with glycyrrhizin to reduce inflammation and improve functional recovery after traumatic SCI by inhibiting NLRP3 inflammasome activation and promoting microglial M2 polarization. After inducing traumatic SCI by dropping a 10 g impactor on the T9 and T10 spinal segments of male Sprague-Dawley rats, the animals were given glycyrrhizin orally immediately after injury and every 12 h for the next 3 d. Behavioral scores improved in glycyrrhizin-treated animals compared to the SCI group. The functional improvement in glycyrrhizin-treated rats paralleled the decreased expression of NLRP3 inflammasome components, such as ASC, NLRP3, and cleaved caspase-1, as well as IL-1ß and IL-18. At the histopathological level, oral treatment with glycyrrhizin diminished the SCI-enhanced production of Iba-1+CD86+ cells (M1 microglia) but improved the release of Iba-1+CD206+ cells (M2 microglia). Likewise, oral therapy with glycyrrhizin significantly enriched the protein expression levels of M2 microglia-related markers (CD206 and Arg-1) but reduced those of M1 microglia-related markers (CD86 and iNOS) in the injured spinal cord. These findings support and extend the knowledge on post-traumatic SCI glycyrrhizin-mediated neuroprotection. Glycyrrhizin's regulation of NLRP3 inflammasome activation and microglial polarization might be a new approach to understanding the anti-inflammatory potency of glycyrrhizin.

Folate inhibits miR-27a-3p expression during cervical carcinoma progression and oncogenic activity in human cervical cancer cells.

BACKGROUND: Folate deficiency has been long implicated in cancer development. Although the role of folate in preventing cervical cancer is still unclear, emerging evidence shows that microRNAs (miRs) have great influence on tumor cell migration and invasion. OBJECTIVES: The purpose of this study was to conduct an integrated analysis of miR expression in squamous cell carcinoma tissues with adequate or deficient serum folate. Further, study conducted tissue validation and functional analysis of miRs to uncover novel pathogenic mechanisms on the role of folate in squamous cell carcinoma (SCC). MATERIALS AND METHODS: miR expression profiles were obtained from five paired primary SCC tumors with sufficient or deficient serum folate levels through Affymetrix GeneChip microRNA 4.0. This was followed by an integrated bioinformatics analysis and expanded sample size to verify core miRs by molecular biological validation. HeLa and SiHa cells with different concentrations of folate were used to clarify the roles of miR-27a on cell proliferation, migration, and invasion. MiR-27a expression was measured by the quantitative real-time polymerase chain reaction. Cell counting proliferation, wound healing, and transwell invasion assays were used to determine cell survival, proliferation, migration, and invasion abilities, respectively. RESULTS: Our study found increasing miR-27a expression in serum of normal, high-grade squamous intraepithelial lesion (HSIL), and SCC tissues (in order of magnitude), which trend was negatively correlated with serum folate content. Further, there were significant differences in cellular miR-27a expression between 200 nM and 500 nM folate concentrations, with higher folate concentrations showing lower proliferation, migration, and invasion in SCC. Finally, miR-27a promoted proliferation and invasion in HeLa cells, whereas a miR-27a inhibitor blocked cell proliferation and invasion. CONCLUSION: There is a significant association between miR-27a expression and folate during cervical carcinoma progression. Therefore, miR-27a could be used as a new biomarker for SCC diagnosis and prediction, suggesting a new therapeutic strategy for SCC treatment.

Isofraxidin attenuates IL-1ß-induced inflammatory response in human nucleus pulposus cells.

Inflammation has been demonstrated to be the key factor for intervertebral disc degeneration (IVD), which remains a major public health problem. Isofraxidin is a coumarin compound that possesses strong anti-inflammatory activity. However, the role of isofraxidin in IVD remains unclear. The aim of this study was to evaluate the effects of isofraxidin on inflammatory response in human nucleus pulposus cells (NPCs) exposed to interleukin-1ß (IL-1ß). The results proved that isofraxidin attenuated the IL-1ß-induced significant increases in inflammatory mediators and cytokines including nitric oxide (NO), inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE2), tumor necrosis factor alpha (TNF-α), and IL-6. Besides, isofraxidin also inhibited the induction effect of IL-1ß on matrix metalloproteinases (MMP)-3 and MMP-13. Moreover, the NF-κB activation caused by IL-1ß was significantly inhibited by isofraxidin treatment. These findings suggested that isofraxidin alleviates IL-1ß-induced inflammation in NPCs. Our work provided an idea that isofraxidin might act as a novel preventive role in IVD.

Terahertz electric field modulated mode coupling in graphene-metal hybrid metamaterials.

Taking advantage of the tunable conductivity of graphene under high terahertz (THz) electric field, a graphene-metal hybrid metamaterial consisting of an array of three adjoined orthogonally oriented split-ring resonators (SRRs) is proposed and experimentally demonstrated to show a maximum modulation depth of 23% in transmission when the THz peak field reaches 305 kV/cm. The transmission of the sample is dominated by the antisymmetric and symmetric resonant modes originating from the strong magneto-inductive and conductive coupling among the three SRRs, respectively. Numerical simulations and model calculations based on a coupled oscillator theory were performed to explain the modulation process. It is found that the graphene coating impairs the resonances by increasing the damping of the modes and decreasing the coupling between the SRRs whereas the strong THz field restores the resonances by decreasing the conductivity of graphene.

MicroRNA-30c abrogation protects against spinal cord ischemia reperfusion injury through modulating SIRT1.

Spinal cord ischemia/reperfusion (I/R) injury is a severe complication in many surgeries. Although microRNAs (miRNAs) are involved in I/R-caused spinal cord injury (SCI), the mechanism that underlies miR-30c interacted with SCI remains elusive. In this study, I/R surgery or oxygen-glucose deprivation (OGD) were performed to establish SCI model in vivo or in vitro, respectively. Basso, Beattie and Bresnahan (BBB) score, spinal cord infarct, terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) staining, flow cytometry and enzyme linked immunosorbent assays (ELISA) were used to investigate SCI. Quantitative real-time polymerase chain reaction (qRT-PCR) was conducted to examine the abundances of miR-30c and sirtuin 1 (SIRT1) either in spinal cord or PC12 cells. Luciferase assay and RNA immunoprecipitation (RIP) were performed to probe the interaction between miR-30c and SIRT1. Western blot and immunofluorescence assays were used to analyze SIRT1 protein expression. Our results showed that I/R increased miR-30c expression and induced SCI, revealed by decreasing BBB score, enhancing apoptosis, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) expression. However, miR-30c knockdown attenuated I/R-induced SCI in vivo. Moreover, depletion of miR-30c protected PC12 cells against OGD-caused apoptosis and inflammatory response. In addition, SIRT1 was limited by miR-30c, silencing of which reversed anti-miR-30c-mediated inhibitory effect on apoptosis and secretion of inflammatory cytokines in PC12 cells after OGD treatment. Collectively, abrogation of miR-30c inhibited spinal cord ischemia reperfusion injury through targeting SIRT1, providing a promising biomarker of prognosis and therapeutic for SCI.

Therapeutic effect of apocynin through antioxidant activity and suppression of apoptosis and inflammation after spinal cord injury.

Spinal cord injury (SCI) is a devastating condition affecting hundreds of thousands of people worldwide annually. SCI results in activation of the inflammatory response and apoptosis, and generates oxidative stress, which has deleterious effects on the recovery of motor function. Apocynin, an inhibitor of NADPH oxidase, has been demonstrated to improve neuronal functional recovery in rat models of SCI. However, the efficacy of apocynin treatment post-SCI has not been investigated. The aim of this study was to observe the effects of apocynin on the repair of acute spinal cord damage in rats and to examine the potential beneficial effects. A rat model of SCI was established, and apocynin (50 mg/kg) was administered intraperitoneally at 30 min after SCI and then every 12 h for 3 days. In order to examine oxidative tissue injury, the levels of malondialdehyde and glutathione and activities of myeloperoxidase and superoxide dismutase in the spinal cord tissues were measured. Histological evaluations were also conducted. NeuN labeling, TUNEL staining and caspase 3 immunohistochemical staining were performed to analyze neuronal damage and apoptosis around the lesion. Immunohistochemical analysis was also carried out to observe the expression of CD11b and glial fibrillary acidic protein. The expression levels of bax, bcl-2, tumor necrosis-α, interleukin (IL)-1ß and IL-6 in the spinal cord tissue were assayed by western blotting. Finally, locomotor function was evaluated using the inclined plane test and Basso, Beattie and Bresnahan scores. The results showed that treatment with apocynin decreased oxidative damage, alleviated neuronal apoptosis, inhibited the inflammatory response and resulted in the promotion of locomotor function. Therefore, this study confirmed the therapeutic efficacy of apocynin in the repair of SCI, which was probably mediated via the inhibition of apoptosis and the inflammatory response, thus promoting the restoration of nerve function.

Frequency-agile electromagnetically induced transparency analogue in terahertz metamaterials.

Recently reported active metamaterial analogues of electromagnetically induced transparency (EIT) are promising in developing novel optical components, such as active slow light devices. However, most of the previous works have focused on manipulating the EIT resonance strength at a fixed characteristic frequency and, therefore, realized on-to-off switching responses. To further extend the functionalities of the EIT effect, here we present a frequency tunable EIT analogue in the terahertz regime by integrating photoactive silicon into the metamaterial unit cell. A tuning range from 0.82 to 0.74 THz for the EIT resonance frequency is experimentally observed by optical pump-terahertz probe measurements, allowing a frequency tunable group delay of the terahertz pulses. This straightforward approach delivers frequency agility of the EIT resonance and may enable novel ultrafast tunable devices for integrated plasmonic circuits.

Pancharatnam-Berry Phase Induced Spin-Selective Transmission in Herringbone Dielectric Metamaterials.

A dielectric metamaterial approach for achieving spin-selective transmission of electromagnetic waves is proposed. The design is based on spin-controlled constructive or destructive interference between propagating phase and Pancharatnam-Berry phase. The dielectric metamaterial, consisting of monolithic silicon herringbone structures, exhibits a broadband operation in the terahertz regime.

Active metasurface terahertz deflector with phase discontinuities.

Metasurfaces provide great flexibility in tailoring light beams and reveal unprecedented prospects on novel functional components. However, techniques to dynamically control and manipulate the properties of metasurfaces are lagging behind. Here, for the first time to our knowledge, we present an active wave deflector made from a metasurface with phase discontinuities. The active metasurface is capable of delivering efficient real-time control and amplitude manipulation of broadband anomalous diffraction in the terahertz regime. The device consists of complementary C-shape split-ring resonator elements fabricated on a doped semiconductor substrate. Due to the Schottky diode effect formed by the hybrid metal-semiconductor, the real-time conductivity of the doped semiconductor substrate is modified by applying an external voltage bias, thereby effectively manipulating the intensity of the anomalous deflected terahertz wave. A modulation depth of up to 46% was achieved, while the characteristics of broadband frequency responses and constant deflected angles were well maintained during the modulation process. The modulation speed of diffraction amplitude reaches several kilohertz, limited by the capacitance and resistance of the depletion region. The scheme proposed here opens up a novel approach to develop tunable metasurfaces.