Digital coding Fano resonance based on active plasmonic metamaterials.

A novel approach that employs active plasmonic metamaterials to create a digital coding Fano resonator is proposed, to the best of our knowledge. The meta-device consists of three concentric spoof localized surface plasmon (LSP) resonators and three positive-intrinsic-negative (PIN) diodes positioned at three slits located in the middle and inner LSP resonators. Four Fano resonant modes can be independently switched by controlling the biased voltage applied to the three diodes. This provides a means for encoded modulation of multiple Fano resonances in metamaterials, which could have broad applications in fields such as multiway sensing, plasmonic circuits, and switching. We experimentally demonstrate the effectiveness of the proposed approach, which offers promising potential for practical implementation.

Predictive Factors and Nomogram to Evaluate the Risk of Symptomatic Intracerebral Hemorrhage for Stroke Patients Receiving Thrombectomy.

BACKGROUND: Symptomatic intracerebral hemorrhage (sICH) is a severe complication of mechanical thrombectomy (MT). This study is to identify predictive factors and create a nomogram to evaluate the risk of sICH after MT treatment. METHODS: We conducted a retrospective analysis on 127 consecutive stroke patients treated by MT therapy. We evaluated multiple predictive factors for the incidence of sICH using univariate and multivariate logistic regressions. Based on the identified and other possible factors, a nomogram was constructed to predict the risk of sICH. RESULTS: We identified several predictive factors for sICH in the univariate analysis, including thrombectomy maneuvers >3 (odds ratio [OR], 4.42; 95% confidence interval [CI], 1.25-15.6; P = 0.0211), admission blood glucose (OR, 1.29; 95% CI, 1.13-1.48; P = 0.0002), diabetes mellitus (OR, 4.44; 95% CI, 1.64-12.0; P = 0.0033), and admission National Institutes of Health Stroke Scale (NIHSS) score (OR, 1.05; 95% CI, 1.01-1.10; P = 0.0263). The multivariate analysis showed that admission NIHSS score and blood glucose significantly affected the prognosis. Moreover, the proposed nomogram showed reliable identification ability with an area under the curve of 0.82 (95% CI, 0.71-0.93), specificity of 0.745, sensitivity of 0.762, accuracy of 0.748, and negative predictive value of 0.941. CONCLUSIONS: Our study identified the admission NIHSS score and admission blood glucose level as predictive factors for sICH. Moreover, the proposed nomogram based on possible factors showed reliable predictive performance in evaluating the risk of sICH.

[Color quantification and evaluation of landscape aesthetic quality for autumn landscape forest based on visual characteristics in subalpine region of western Sichuan, China]. / 基于视觉特性的川西亚高山秋季景观林色彩量化及景观美学质量评价.

Evaluation of landscape aesthetic quality is a key step in the management system of forest resource. Color is an important component of autumn landscape forest, and quantitative analysis of color and scientific evaluation of landscape aesthetic quality are important for the management of autumn landscape forest. We assessed the aesthetic quality of autumn landscape forest using scenic beauty estimation and analyzed the effects of color characteristics on ornamental value of autumn landscape forest based on color composition and color spatial pattern according to human's visual characteristics. The results showed that the overall landscape quality of subalpine region of western Sichuan could be divided into five grades according to beauty value (I to V). About 71.5% of autumn landscape forests could be classified into grade I, II, and III, indicating that autumn landscape forests of subalpine region in western Sichuan had higher ornamental value. According to the scenic beauty estimation value, the landscape aesthetic quality of broadleaved mixed forests was higher than that of coniferous and broadleaved mixed forests and pure forests. In terms of the comprehensive index evaluation system of color elements, the index weight coefficient order was landscape patch heterogeneity factors>autumn main color factors>color saturation and brightness factors>color diversity and evenness factors. With cluster analysis, autumn landscape forests of western Sichuan could be divided into three types. The forests with higher ornamental value showed following characteristics: larger degree of patch fragmentation and heterogeneity, higher percentage of orange and yellow and lower percentage of green in autumn, higher percentage of color saturation and brightness, and higher color diversity and uniformity index. The communities with higher richness, species diversity and evenness index would have higher beauty values. We concluded that species diversity and fragmentation of colors should be considered in the construction of autumn landscape forests, and that aesthetic quality of autumn landscape forest could be improved by planting and cultivating tree species with various and bright autumn leaf colors.

Selective amplification of spoof localized surface plasmons.

Here, selective amplification of spoof localized surface plasmons (LSPs) has been demonstrated, where two coupling stubs gathering energies from the spoof LSPs resonator are designed on the back of the corrugated metal-insulator-metal ring resonator. The quadrupole mode is selected and amplified through the coupling stubs and the incorporated amplifier chip, and the measured transmission intensity has been increased from $ - {6.46}\;{\rm dB}$-6.46dB to 10.74 dB by adjusting the bias voltage. The amplification mechanism is fully investigated by using the circuit simulation and the full-wave simulation. The numerical simulations and experimental measurement agree well with each other. The active amplified resonator can be widely used in chemical and biological sensing in microwave frequency.

Gain-assisted ultra-high-Q spoof plasmonic resonator for the sensing of polar liquids.

By directly incorporating a sub-wavelength amplifier chip into the spoof plasmonic resonator, the quality (Q) factor of the original passive resonator has been significantly increased by several orders of magnitude. The spoof plasmonic resonator is composed of a corrugated ring with a slit whose optimized offset angle φ is 45°, aiming to achieve a better Q-factor. By tuning the bias voltage applied to the amplifier chip that is placed across the slit, the Q factor has been increased from 9.8 to 21000 for the quadrupole mode when a plastic pipe filled with polar liquids is placed upon the resonator. Experiments at the microwave frequencies verify that the amplifier chip could greatly compensate the loss introduced by the polar liquids under investigation, resulting in an ultra-high-Q sensor for the detection of polar liquids.

[Functional Group Characteristics of Planktonic Diatoms and Their Relationship with Environmental Factors in the Ruxi River].

To elucidate the functional group characteristics of planktonic diatoms and their relationship with environment factors in the Ruxi River, multivariate statistical analysis and functional group classification were conducted in this study. The success pattern of a diatom functional group and its driving factor were analyzed for the Ruxi River, a typical tributary of Three Gorges Reservoir, after the phytoplankton community and environmental variables were investigated at three different stages: level water period (April 2014), dry season (December 2014), and wet season (July 2014), based on the characteristic of water level. The results showed that there were 10 diatom functional groups in the Ruxi River: the A, B, C, D, Lo, MP, P, TB, X3, and S1 groups, and among them, MP was the most groups, but the dominant group was D group. Stepwise multiple regression analysis indicated that ρ(TN) in the water column was the primary factor significantly affecting the densities in the normal water period, whereas turbidity, alkalinity, and pH significantly influenced the functional group densities in the normal water period. In the high water period, however, transparency was the most important environmental factor affecting the functional group densities. Additionally, the results of RDA analysis found that water temperature, electrical conductivity (Spc), oxidation-reduction potential (ORP), ρ(DO), and ρ(NO3--N) were the main environmental factors that influenced the diversity of diatom functional groups in the Ruxi River. These results suggested that functional groups could well reflect the habitat characteristics of the Ruxi River and the effect of the nutrient element, nitrogen, to the success of phytoplankton functional groups and changes of water quality in the Ruxi River should be paid more attention.

Impact of Intraoperative Blood Pressure Control and Temporary Parent Artery Blocking on Prognosis in Cerebral Aneurysms Surgery.

Objective In cerebral aneurysm clipping and embolization, blood pressure control and temporary parent artery blocking are common methods to prevent aneurysm rupture. Their influence on the prognosis is uncertain. In this study, we try to find out the association between methods above and prognostic indicators.Methods We held a retrospective analysis on patients' medical records of cerebral aneurysms surgical clipping and endovascular coiling , and recorded gender, age, diagnosis, Hunt-Hess grade, Glasgow coma scale score, treatment methods, a history of hypertension, preoperative systolic blood pressure, with or without controlled hypotension, systolic blood pressure difference before and after controlled hypotension, with or without temporary artery blocking, with or without hypertension after treated aneurysm, prognostic indicators including mortality after 1 month, intensive care unit (ICU) stay time of survivors, discharged Glasgow outcome scale (GOS) score. Prognostic indicators were regarded as dependent variable, all the factors were regarded as independent variable, and the strength analysis of influence factors on prognostic indicators was made by binary logistic regression.Results Total cases were 165, including 68 males and 97 females, with an average age of 56 (12-85) years. The mortality after 1 month was 10.9% (18 cases). The ICU stay time of survivors was 7.35 (0-67) days. GOS score at discharge was 1-3 in 40 (24.2%) patients and 4-5 in 125 (75.8%) patients. Systolic blood pressure difference before and after controlled hypotension was an independent factor influencing mortality (t=2.273, P=0.024), and the greater the difference was, the higher the mortality would be. Timely hypertension after aneurysm treated was an independent factor affecting ICU stay time of survivors and patients with hypertension had shorter ICU stay time (χ2=10.017, P=0.001). Blood pressure control (χ2=0.088, P=0.767) and temporary blocking (χ2=1.307, P=0.253) did not show significant influence on GOS score at discharge.Conclusions Timely controlled hypertension after aneurysm clipping and embolization can significantly shorten the stay time in ICU. The degree of controlled hypotension associates with postoperative mortality, the greater systolic blood pressure difference before and after antihypertensive treatment is, the higher the mortality will be.

Progesterone for Traumatic Brain Injury: A Meta-Analysis Review of Randomized Controlled Trials.

OBJECTIVE: To conduct a meta-analysis to determine whether progesterone, compared with placebo or no treatment, influences mortality and neurologic outcome in traumatic brain injury (TBI). METHODS: To identify eligible studies, systematic searches for randomized controlled trials of progesterone treatment in TBI were conducted in PubMed, Web of Science, EMBASE, Cochrane Library, and ClinicalTrials.gov databases. The search yielded 8 studies that were included in the meta-analysis. Included data were study characteristics, patient demographics, baseline characteristics, progesterone treatment protocol, main outcome of mortality, and secondary neurologic outcome evaluated using the Glasgow Outcome Scale. RESULTS: The 8 studies comprised 2585 patients. The meta-analysis indicated that there was no evidence that progesterone treatment decreased the risk of mortality in patients with TBI; the overall risk ratio was 0.852 (95% confidence interval, 0.632-1.144; P = 0.284). In the secondary outcome analysis, progesterone had no neuroprotective role in improving neurologic outcome; the overall risk ratio was 1.151 (95% confidence interval, 0.0991-1.338; P = 0.06). Subgroup analysis according to the degree of injury assessed by the Glasgow Coma Scale demonstrated similar results. CONCLUSIONS: This study is the largest meta-analysis conducted to date to determine whether progesterone is effective in the treatment of TBI. The findings indicate that progesterone treatment does not decrease mortality or improve neurologic outcome in patients with TBI.

Protective Effect of Ad-VEGF-Bone Mesenchymal Stem Cells on Cerebral Infarction.

AIM: To understand the mechanism of intracerebroventricular transplantation of vascular endothelial growth factor (VEGF) genemodified bone mesenchymal stem cells (BMSCs) in rats after cerebral infarction. MATERIAL AND METHODS: The middle cerebral artery occlusion ischemia/reperfusion (MCAO I/R) model was established in rats using the Zea-Longa suture method. A recombinant adenovirus (Ad-VEGF) was engineered to express VEGF. The rats were divided into 3 groups. Control BMSC infected with control adenovirus (BMSC-Ad), BMSC infected by Ad-VEGF (BMSC-Ad-VEGF), and phosphate buffered saline (PBS) suspension were injected into the intracerebroventricular system of the rats in groups 1, 2 and 3 respectively, 24 hours after middle cerebral artery occlusion (MCAO). The neurological function of rats was evaluated with the modified Neurological Severity Scores (mNSS). The infarct volume of brain in rats was determined using 2,3,5-triphenyltetrazolium chloride (TTC) stain at 14 days. GFAP and pGSK3ß expression of ischemic penumbra was determined using immunohistochemical method. GFAP, pAKT, AKT, and pGSK3ß expressions were determined with Western blot. RESULTS: Functional improvement was accelerated in animals receiving BMSC-Ad, while improvement at all times between 7 days and 28 days post MCAO was significantly greater in animals transplanted with BMSC-Ad-VEGF than for other treated animals. The number of GFAP-labeled cells was prevented by post-ischemic BMSC-Ad-VEGF treatment; pMCAO activate the PI3K/AKT/GSK3ß pathway to reduce reactive gliosis. CONCLUSION: Our findings demonstrate that PI3K/AKT/GSK3ß pathway could reduce reactive gliosis, ameliorate neurological deficit, diminish the percentage of cerebral infarction volume in rats, and facilitate angiogenesis.

Stereotactic radiosurgery of brainstem cavernous malformations: a systematic review and meta-analysis.

OBJECT: Over the last two decades, stereotactic radiosurgery (SRS) has arisen as a promising approach in the management of brainstem cavernous malformations (CMs). In the present study, the authors report a systematic review and meta-analysis of the available published data regarding the radiosurgical management of brainstem CMs. METHODS: To identify eligible studies, systematic searches for brainstem CMs treated with SRS were conducted in major scientific publication databases. The search yielded 5 studies, which were included in the meta-analysis. Data from 178 patients with brainstem CMs were extracted. Hemorrhage rates before and after SRS were calculated, a meta-analysis was performed, and the risk ratio (RR) was determined. RESULTS: Four studies showed a statically significant reduction in the annual hemorrhage rate after SRS. The overall RR was 0.161 (95% CI 0.052-0.493; p = 0.001), and 21 patients (11.8%) had transient or permanent neurological deficits. CONCLUSIONS: The present meta-analysis for the radiosurgical management of brainstem CMs shows that SRS can decrease the rate of repeat hemorrhage and has a low rate of adverse effects compared with surgery. The authors suggest that SRS may be considered as an alternative treatment for brainstem CMs that are inoperable or have a high operative risk.

Intravascular infusion of lidocaine: a novel way to relieve sudden internal carotid artery occlusion in embolization of intracranial aneurysms.

BACKGROUND: Sudden internal carotid artery (ICA) occlusive vasospasm is a serious complication of intracranial aneurysm embolization. Conventional spasmolysis with papaverine yields a generally poor outcome. We believe that arterial infusion of lidocaine may offer a better outcome. MATERIALS AND METHODS: We retrospectively reviewed the outcome of patients treated with either papaverine or lidocaine infusion for vasospasm during embolization. RESULTS: 14 patients undergoing intracranial aneurysm embolization had a ICA occlusive vasospasm. Among the 8 patients who received conventional treatment with papaverine the vasospasm improved partially in 5. In 3 cases, treatment was ineffective. 6 of the patients died within 3 days. 2 patients developed hemispheric infarction and underwent a decompressive craniectomy and subtotal resection of the infarct; 1 of these 2 patients died after 4 months and the other was severely disabled. In the 6 patients treated with lidocaine, spasmolysis and subsequent aneurysm treatment was successful in 5. In 1 patient who had preoperative stenosis of the carotid artery proximal to the aneurysm spasmolysis failed. CONCLUSIONS: ICA occlusive spasm is an extremely serious and often lethal complication in embolization of intracranial aneurysms. Conventional treatment with papaverine has a poor outcome, whereas arterial infusion of lidocaine may achieve better results.

[Mechanism of ING4 mediated inhibition of the proliferation and migration of human glioma cell line U251].

AIM: To investigate the effect of Ad-ING4 on proliferation and migration of glioma cells and explore its probable mechanism. METHODS: U251 were infected with Ad-ING4. ING4 gene expression was evaluated by RT-PCR. MTT assay was adopted to evaluate the effect of ING4 on proliferation of U251; Boyden chamber assay was used to check the effect of ING4 on the migration of U251. In ING4 transfected U251, Western blot was used for detecting NGF and TrkA expression; Pull-down assay was used for detecting active RhoA expression. RESULTS: ING4 was overexpressed in Ad-ING4 transfected U251 cells. ING4 inhibited proliferation and migration of U251 significantly. Moreover, overexpression of ING4 result in depression of NGF, TrkA and active RhoA. CONCLUSION: ING4 mediated inhibition of the proliferation and migration of human glioma cells by down regulating NGF, TrkA and active RhoA expression.

Nerve growth factor expression in astrocytoma and cerebrospinal fluid: a new biomarker for prognosis of astrocytoma.

BACKGROUND: Recent studies have discovered that nuclear translocation of nerve growth factor (NGF) and its receptor fragments function differently from the traditional model. This study aimed to uncover the nuclear expression of NGF in astrocytoma and its biological significance. METHODS: Ninety-four paraffin-embedded astrocytoma specimens were subjected to immunohistochemical (IHC) and hemotoxylin & eosin (HE) staining. Preoperative cerebrospinal fluid (CSF) specimens and intraoperative snap-frozen astrocytoma tissues were assayed for NGF expression by ELISA and Western blotting. The outcome of patients who contributed samples was tracked. Each ten tissue samples from patients with traumatic brain injury who had received decompression surgery and CSF samples from patients undergoing spinal anesthesia but with no history of nervous system disease were taken as control. RESULTS: NGF-positive immunoreactive products were distributed in both the cytoplasm and nucleus of astrocytoma, but were only located in the cytoplasm of traumatic brain injury (TBI) tissue. NGF nuclear-positive rate (NPR) of grades III - IV astrocytomas (70.0%) was higher than that of grades I - II astrocytoma (28.6%, P < 0.05). NGF-NP expression positively correlated with the NGF concentration in cerebrospinal fluid (CSF) (r = 0.755, P < 0.01). Kaplan-Meier survival analysis indicated that the median survival time was 25 months for NGF-NP astrocytoma grade I - II patients and 42 months in NGF nuclear negative (NGF-NN) astrocytoma grade I - II patients (P < 0.05). In astrocytoma III - IV patients, the median survival was 7 months for NGF-NP patients and 24 months for NGF-NN patients (P < 0.01). Two types of NGF with molecular weights of 13 and 36 kDa were present in astrocytoma, but only the 36 kDa NGF was found in the CSF. NGF expression elevated as the malignancy increased. CONCLUSIONS: NGF-NP expression and NGF level in CSF were significant prognostic factors in astrocytoma patients. Because of the easy access of CSF, it may be developed as an index for early diagnosis and surveillance of astrocytoma.