46 research outputs found

    Multi-Signal Detection Framework: A Deep Learning Based Carrier Frequency and Bandwidth Estimation

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    Multi-signal detection is of great significance in civil and military fields, such as cognitive radio (CR), spectrum monitoring, and signal reconnaissance, which refers to jointly detecting the presence of multiple signals in the observed frequency band, as well as estimating their carrier frequencies and bandwidths. In this work, a deep learning-based framework named SigdetNet is proposed, which takes the power spectrum as the network’s input to localize the spectral locations of the signals. In the proposed framework, Welch’s periodogram is applied to reduce the variance in the power spectral density (PSD), followed by logarithmic transformation for signal enhancement. In particular, an encoder-decoder network with the embedding pyramid pooling module is constructed, aiming to extract multi-scale features relevant to signal detection. The influence of the frequency resolution, network architecture, and loss function on the detection performance is investigated. Extensive simulations are carried out to demonstrate that the proposed multi-signal detection method can achieve better performance than the other benchmark schemes

    In vitro and in vivo evaluation of zinc-modified ca-si-based ceramic coating for bone implants.

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    The host response to calcium silicate ceramic coatings is not always favorable because of their high dissolution rates, leading to high pH within the surrounding physiological environment. Recently, a zinc-incorporated calcium silicate-based ceramic Ca2ZnSi2O7 coating, developed on a Ti-6Al-4V substrate using plasma-spray technology, was found to exhibit improved chemical stability and biocompatibility. This study aimed to investigate and compare the in vitro response of osteoblastic MC3T3-E1 cells cultured on Ca2ZnSi2O7 coating, CaSiO3 coating, and uncoated Ti-6Al-4V titanium control at cellular and molecular level. Our results showed Ca2ZnSi2O7 coating enhanced MC3T3-E1 cell attachment, proliferation, and differentiation compared to CaSiO3 coating and control. In addition, Ca2ZnSi2O7 coating increased mRNA levels of osteoblast-related genes (alkaline phosphatase, procollagen α1(I), osteocalcin), insulin-like growth factor-I (IGF-I), and transforming growth factor-ÎČ1 (TGF-ÎČ1). The in vivo osteoconductive properties of Ca2ZnSi2O7 coating, compared to CaSiO3 coating and control, was investigated using a rabbit femur defect model. Histological and histomorphometrical analysis demonstrated new bone formation in direct contact with the Ca2ZnSi2O7 coating surface in absence of fibrous tissue and higher bone-implant contact rate (BIC) in the Ca2ZnSi2O7 coating group, indicating better biocompatibility and faster osseointegration than CaSiO3 coated and control implants. These results indicate Ca2ZnSi2O7 coated implants have applications in bone tissue regeneration, since they are biocompatible and able to osseointegrate with host bone

    Corneal densitometry changes in a patient with interface fluid syndrome after small incision lenticule extraction

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    Abstract Background To report a case of interface fluid syndrome (IFS) following small incision lenticule extraction (SMILE) evaluated with corneal densitometry and optical coherence tomography (OCT). Case presentation An 18-year-old man reported sudden vision loss 24 days after SMILE procedure. Intraocular pressure (IOP) was 36.3 mmHg (OD) and 36.7 mmHg (OS) by noncontact tonometry. Moderate corneal edema, interface fluid pocket and haze were observed by OCT and confirmed by corneal densitometry values. Discontinuation of steroids and addition of hypotensive medication were offered immediately. The symptoms were cured after the medication. Changes of corneal densitometry were consistent with the clinical course of IFS. Conclusion This case illustrates that it is crucial to be aware that a history of SMILE can also cause IFS. Both OCT and corneal densitometry can serve as auxiliary means to evaluate the clinical course of IFS, and appropriate IOP management is an effective approach

    A non-invasive far-red light-induced split-Cre recombinase system for controllable genome engineering in mice

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    Current light-inducible Cre-loxP systems have minimal capacity for deep tissue penetration. Here, the authors present a far-red light-induced split Cre-loxP system for in vivo genome engineering

    The differential diagenesis controls on the physical properties of lithofacies in sandstone reservoirs from the Jurassic Shaximiao Formation, western Sichuan depression, China

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    The Jurassic Shaximiao Formation on the eastern slope of western Sichuan depression in western Sichuan Basin of China develops a single or overlapping channel sandstones with strong internal heterogeneity. This study aims to reveal the origin of the differences of physical properties within the sandstone reservoirs under different assemblies of lithofacies. Based on analysis of sedimentary structure and grain size, the lithofacies are classified into nine types. Based on the classification of lithofacies formed under different energy of sedimentary environment and mechanical differentiation, the effect of early compaction on physical properties of sandstone reservoirs is confirmed. It is suggested that the physical properties of lithofacies can be influenced by differential diagenesis in different lithofacies assemblies. The rate of early compaction depends on the grain sorting and compositional maturity. The massive bedded lithofacies are prone to be of good grain sorting and high compositional maturity with relatively low compaction rate of 70.91%–72.75%. There are relatively high porosities and permeabilities of sandstones in the lithofacies assembly containing massive bedded lithofacies. Because of the export of diagenetic fluid along the bedding plane of parallel bedded sandstones, there would be relatively intensive dissolution of sandstones developed with parallel bedded lithofacies. Even if the development of parallel bedded sandstones could enhance the dissolution, yet they are subjected to relatively strong compaction, leading to the low proportion of intergranular pores. The permeability of sandstones within the lithofacies assembly containing parallel bedded lithofacies seems to be low. The porosity and permeability of sandstones within the lithofacies assembly containing horizontal bedded lithofacies are both poorer than other assemblies, caused by strong compaction, cementation and weak dissolution. The direction of bedding, argillaceous contents, and the capacity of resistance to compaction are the key factors controlling the physical property of high-quality sandstone reservoirs. The research conclusions can be used to interpret the genesis of different physical properties of sandstone reservoirs in other similar gas fields

    An Optogenetic‐Controlled Cell Reprogramming System for Driving Cell Fate and Light‐Responsive Chimeric Mice

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    Abstract Pluripotent stem cells (PSCs) hold great promise for cell‐based therapies, disease modeling, and drug discovery. Classic somatic cell reprogramming to generate induced pluripotent stem cells (iPSCs) is often achieved based on overexpression of transcription factors (TFs). However, this process is limited by side effect of overexpressed TFs and unpredicted targeting of TFs. Pinpoint control over endogenous TFs expression can provide the ability to reprogram cell fate and tissue function. Here, a light‐inducible cell reprogramming (LIRE) system is developed based on a photoreceptor protein cryptochrome system and clustered regularly interspaced short palindromic repeats/nuclease‐deficient CRISPR‐associated protein 9 for induced PSCs reprogramming. This system enables remote, non‐invasive optogenetical regulation of endogenous Sox2 and Oct4 loci to reprogram mouse embryonic fibroblasts into iPSCs (iPSCLIRE) under light‐emitting diode‐based illumination. iPSCLIRE cells can be efficiently differentiated into different cells by upregulating a corresponding TF. iPSCLIRE cells are used for blastocyst injection and optogenetic chimeric mice are successfully generated, which enables non‐invasive control of user‐defined endogenous genes in vivo, providing a valuable tool for facile and traceless controlled gene expression studies and genetic screens in mice. This LIRE system offers a remote, traceless, and non‐invasive approach for cellular reprogramming and modeling of complex human diseases in basic biological research and regenerative medicine applications

    Antiulcerogenic Activity of Li-Zhong Decoction on Duodenal Ulcers Induced by Indomethacin in Rats: Involvement of TLR-2/MyD88 Signaling Pathway

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    Background. Administration of nonsteroidal anti-inflammatory drugs (NSAIDs) often causes small intestinal ulcers in patients, but few effective drugs are currently available to manage such serious adverse events of NSAIDs. Li-Zhong decoction (LZD), a well-known traditional Chinese medicine (TCM) formula, is commonly prescribed for treatment of gastrointestinal diseases. The present study aimed to investigate the anti-ulcerogenic activity of LZD on indomethacin- (IND-) induced duodenal ulcer in rats. Mechanistic studies of action of LZD were focused on involvement of TLR-2/MyD88 signaling pathway. Methods. Fifty male Sprague-Dawley (SD) rats were randomly and evenly divided into five groups: normal control, ulcer control (IND, 25 mg/kg), IND + esomeprazole (ESO, 4.17 mg/kg), and IND + low and high doses of LZD (3.75 and 7.50 g/kg). Macroscopic and histopathological examinations were performed for evaluation of ulcer index (UI), curative index (CI), and microscopic score (MS). Levels of duodenal inflammatory biomarkers and cytoprotective mediators including interleukin-4 (IL-4), IL-10, tumor necrosis factor-α (TNF-α), and prostaglandin E2 (PGE2) were measured by ELISA. Expression levels of TLR-2 and MyD88 mRNA were assessed by qRT-PCR. The expression and distribution of TLR-2 and MyD88 proteins were analyzed by western blot and immunohistochemistry, respectively. Results. Gross and microscopic examinations of the IND-treated rats revealed severe duodenal hemorrhagic necrosis, inflammatory infiltration, villus destruction, and crypt abscess, while LZD-treated rats manifested these pathological events to a markedly lesser degree. LZD significantly decreased UI and MS, increased CI, preserved the integrity of the villus and crypt, and normalized the tissue architecture of the duodenum of rats. The elevated TNF-α levels in the IND-treated rats were markedly diminished in the LZD-treated rats, while lower levels of IL-4, IL-10, and PGE2 observed in IND-treated rats were significantly increased in LZD-treated rats. Interestingly, improvement of immune function in duodenal mucosa by reduction of mRNA and protein expression levels of TLR-2 and MyD88 was also observed in rats treated with LZD. Consistently, immunohistochemical analyses revealed a lower co-localization of TLR-2 and MyD88 proteins in the duodenal mucosa of LZD-treated rats as compared to the IND-induced rats. Conclusions. Our data demonstrate that LZD protects the duodenal mucosa from IND-caused lesions, which is at least partially attributable to the interaction of its potential cytoprotective and anti-inflammatory mechanisms together with enhancement of the mucosal immunity through TLR-2/MyD88 signaling pathway

    ALP activity in MC3T3-E1 cells cultured on control, CaSiO<sub>3</sub> and Ca<sub>2</sub>ZnSi<sub>2</sub>O<sub>7</sub> coated substratesfor 1, 4, 7 and 14 days.

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    <p>All experiments were repeated twice with n = 3 for each substrate. *Ca<sub>2</sub>ZnSi<sub>2</sub>O<sub>7</sub> coating compared with CaSiO<sub>3</sub> coating or control, <i>p</i><0.05. Results are presented as mean ± SD.</p

    Characterization and Genomic Analysis of Novel Vibrio parahaemolyticus Phage vB_VpaP_DE10

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    In the present study, a novel lytic Vibrio parahaemolyticus phage, vB_VpaP_DE10, was isolated from sewage samples collected in Guangzhou city, China. Transmission electron microscopy revealed that phage vB_VpaP_DE10 has an icosahedral head (52.4 &plusmn; 2.5 nm) and a short non-contracted tail (21.9 &plusmn; 1.0 nm). Phage vB_VpaP_DE10 lysed approximately 31% (8/26) of the antibiotic-resistant V. parahaemolyticus strains tested. A one-step growth curve showed that phage vB_VpaP_DE10 has a relatively long latency time of 25 min and a burst size of ~19 PFU per cell. The genome of phage vB_VpaP_DE10 is a 42,871-bp-long dsDNA molecule with a G + C content of 49.19% and is predicted to contain 46 open reading frames, 26 of which are predicted to be related to functions such as phage structure, packaging, host lysis, and DNA metabolism. Sequence comparisons suggested that vB_VpaP_DE10 is a member of the genus Maculvirus within the family Autographiviridae. Morphological and genomic analysis indicated that vB_VpaP_DE10 is a novel V. parahaemolyticus phage
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