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121.
122.
Metamaterials are artificial periodic structures with negative permittivity and permeability. Several interesting properties can be obtained in metamaterials, such as negative index behavior, which can be used for building perfect lenses, cloaking, antennas, etc. As the metamaterial’s properties are determined by its structure, the key challenge is to reduce the fabrication cost of the periodic structure on the micrometer or nanometer scale for realistic applications. In this paper, we experimentally demonstrate a new one-step method for the fabrication of a large-area infrared metamaterial at extremely low cost. A metallic mesh is used as a shadow mask during the pulsed laser deposition (PLD) process to fabricate a FeNi/SiC/FeNi multilayer sandwich structure on Si substrate (cm2 level). The sample shows a strong absorption peak in the infrared frequency range, and the absorption intensity changes with the sample’s geometry.  相似文献   
123.
Chronic prostatitis is a common urological disease. The etiology of this disease and effective therapy for its treatment are yet to be elucidated. We investigated the functions of XLQ® in chronic nonbacterial prostatitis using a complete Freund's adjuvant-induced rat model. Prostates and blood samples were collected for further evaluation after oral gavage with XLQ ® or a vehicle for 4 weeks. The results showed that XLQ ® significantly decreased the prostate index, ameliorated the histopathologic changes, and reduced CD3+ and CD45+ cell infiltration in the prostate stroma. Further study showed that XLQ ® suppressed the expression of proinflammatory cytokines, such as interleukin (IL)-1β, IL-2, IL-6, IL-17A, monocyte chemoattractant protein-1, and tumor necrosis factor-α. XLQ ® showed a strong antioxidant capacity by enhancing the activities of antioxidative enzymes (e.g., total superoxide dismutase, catalase, and glutathione peroxidase) and decreasing the level of lipid peroxidation products (malondialdehyde). Moreover, XLQ ® can suppress the activation of nuclear factor-κB and P38-mitogen-activated protein kinase signaling pathways. In summary, XLQ ® has affirmative effects on chronic prostatitis, which could be attributed to its anti-inflammatory and antioxidative capacities. On the basis of these results, XLQ ® can be developed as an effective and safe therapy for chronic prostatitis.  相似文献   
124.
Computed tomography (CT) has a revolutionized diagnostic radiology but involves large radiation doses that directly impact image quality. In this paper, we propose adaptive tensor-based principal component analysis (AT-PCA) algorithm for low-dose CT image denoising. Pixels in the image are presented by their nearby neighbors, and are modeled as a patch. Adaptive searching windows are calculated to find similar patches as training groups for further processing. Tensor-based PCA is used to obtain transformation matrices, and coefficients are sequentially shrunk by the linear minimum mean square error. Reconstructed patches are obtained, and a denoised image is finally achieved by aggregating all of these patches. The experimental results of the standard test image show that the best results are obtained with two denoising rounds according to six quantitative measures. For the experiment on the clinical images, the proposed AT-PCA method can suppress the noise, enhance the edge, and improve the image quality more effectively than NLM and KSVD denoising methods.  相似文献   
125.
Achilles tendon injury is one of the challenges of sports medicine, the aetiology of which remains unknown. For a long time, estrogen receptor β (ERβ) has been known as a regulating factor of the metabolism in many connective tissues, such as bone, muscle and cartilage, but little is known about its role in tendon. Recent studies have implicated ERβ as involved in the process of tendon healing. Tendon‐derived stem cells (TDSCs) are getting more and more attention in tendon physiological and pathological process. In this study, we investigated how ERβ played a role in Achilles tendon healing. Achilles tendon injury model was established to analyse how ERβ affected on healing process in vivo. Cell proliferation assay, Western blots, qRT‐PCR and immunocytochemistry were performed to investigate the effect of ERβ on TDSCs. Here, we showed that ERβ deletion in mice resulted in inferior gross appearance, histological scores and, most importantly, increased accumulation of adipocytes during the early tendon healing which involved activation of peroxisome proliferator‐activated receptor γ (PPARγ) signalling. Furthermore, in vitro results of ours confirmed that the abnormity might be the result of abnormal TDSC adipogenic differentiation which could be partially reversed by the treatment of ERβ agonist LY3201. These data revealed a role of ERβ in Achilles tendon healing for the first time, thereby providing a new target for clinical treatment of Achilles tendon injury.  相似文献   
126.
In desertified regions, shrub-dominated patches are important microhabitats for ground arthropod assemblages. As shrub age increases, soil, vegetation and microbiological properties can change remarkably and spontaneously across seasons. However, relatively few studies have analyzed how ground arthropods respond to the microhabitats created by shrubs of different plantation ages across seasons. Using 6, 15, 24 and 36 year-old plantations of re-vegetated shrubs (Caragana koushinskii) in the desert steppe of northwestern China as a model system, we sampled ground arthropod communities using a pitfall trapping method in the microhabitats under shrubs and in the open areas between shrubs, during the spring, summer and autumn. The total ground arthropod assemblage was dominated by Carabidae, Melolonthidae, Curculionidae, Tenebrionidae and Formicidae that were affected by plantation age, seasonal changes, or the interaction between these factors, with the later two groups also influenced by microhabitat. Overall, a facilitative effect was observed, with more arthropods and a greater diversity found under shrubs as compared to open areas, but this was markedly affected by seasonal changes. There was a high degree of similarity in arthropod assemblages and diversity between microhabitats in summer and autumn. Shrub plantation age significantly influenced the distribution of the most abundant groups, and also the diversity indices of the ground arthropods. However, there was not an overall positive relationship between shrub age and arthropod abundance, richness or diversity index. The influence of plantation age on arthropod communities was also affected by seasonal changes. From spring through summer to autumn, community indices of ground arthropods tended to decline, and a high degree of similarity in these indices (with fluctuation) was observed among different ages of shrub plantation in autumn. Altogether the recovery of arthropod communities was markedly affected by seasonal variability, and they demonstrated distinctive communal fingerprints in different microhabitats for each plantation age stage.  相似文献   
127.
The signaling of Toll-like receptors (TLRs) induces host defense against microbial invasion. Protein posttranslational modifications dynamically shape the strength and duration of the signaling pathways. It is intriguing to explore whether de-SUMOylation could modulate the TLR signaling. Here we identified SUMO-specific protease 6 (SENP6) as an intrinsic attenuator of the TLR-triggered inflammation. Depletion of SENP6 significantly potentiated the NF-κB-mediated induction of the proinflammatory genes. Consistently, SENP6-knockdown mice were more susceptible to endotoxin-induced sepsis. Mechanistically, the small ubiquitin-like modifier 2/3 (SUMO-2/3) is conjugated onto the Lysine residue 277 of NF-κB essential modifier (NEMO/IKKγ), and this impairs the deubiquitinase CYLD to bind NEMO, thus strengthening the inhibitor of κB kinase (IKK) activation. SENP6 reverses this process by catalyzing the de-SUMOylation of NEMO. Our study highlights the essential function of the SENP family in dampening TLR signaling and inflammation.  相似文献   
128.
This paper is to illustrate the infestation and related ecological characteristics of chigger mites on the Asian house rat (Rattus tanezumi). A total of 17,221 chigger mites were collected from 2,761 R. tanezumi rats, and then identified as 131 species and 19 genera in 2 families. Leptotrombidium deliense, the most powerful vector of scrub typhus in China, was the first major dominant species on R. tanezumi. All the dominant mite species were of an aggregated distribution among different individuals of R. tanezumi. The species composition and infestations of chiggers on R. tanezumi varied along different geographical regions, habitats and altitudes. The species-abundance distribution of the chigger mite community was successfully fitted and the theoretical curve equation was Ŝ (R)=37e−(0.28R. The total chigger species on R. tanezumi were estimated to be 199 species or 234 species, and this further suggested that R. tanezumi has a great potential to harbor abundant species of chigger mites. The results of the species-plot relationship indicated that the chigger mite community on R. tanezumi in Yunnan was an uneven community with very high heterogeneity. Wide geographical regions with large host samples are recommended in the investigations of chigger mites.  相似文献   
129.
成年去胸腺(ATx)大鼠和老年大鼠肝微粒体混合功能氧化酶(MFO,包括细胞色素P450、氨基比林-N-脱甲基酶)的活力比成年对照大鼠的低,且降低幅度雄性明显大于雌性。雄性ATx大鼠和老年大鼠血浆睾酮(T)水平降低,雌二醇(E_2)水平增高,E_2/T比值明显增高;雌性ATx大鼠和老年大鼠血浆E_2和T水平均降低,E_2/T比值无明显变化。给雄性ATx大鼠皮下注射丙酸睾丸素可使其肝微粒体MFO活力恢复。提示胸腺对肝脏MFO的影响可能是通过性激素介导的。  相似文献   
130.
Pretreatment and Lignocellulosic Chemistry   总被引:2,自引:0,他引:2  
Lignocellulosic materials such as wood, grass, and agricultural and forest residues are promising alternative energy resources that can be utilized to produce ethanol. The yield of ethanol production from native lignocellulosic material is relatively low due to its native recalcitrance, which is attributed to, in part, lignin content/structure, hemicelluloses, cellulose crystallinity, and other factors. Pretreatment of lignocellulosic materials is required to overcome this recalcitrance. The goal of pretreatment is to alter the physical features and chemical composition/structure of lignocellulosic materials, thus making cellulose more accessible to enzymatic hydrolysis for sugar conversion. Various pretreatment technologies to reduce recalcitrance and to increase sugar yield have been developed during the past two decades. This review examines the changes in lignocellulosic structure primarily in cellulose and hemicellulose during the most commonly applied pretreatment technologies including dilute acid pretreatment, hydrothermal pretreatment, and alkaline pretreatment.  相似文献   
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