120 research outputs found
A Compact Dual-Band MIMO Antenna for Sub-6 GHz 5G Terminals
In this paper, a dual-band multiple-input-multiple-output (MIMO) antenna is proposed for fifth-generation (5G) wireless communication terminals. The measured −10 dB impedance bandwidths of 380 MHz (3.34–3.72 GHz) and 560 MHz (4.57–5.13 GHz) can cover the 3.4–3.6 GHz and 4.8–5 GHz 5G bands. The single antenna element of this proposed MIMO is composed of an F-shaped feed strip and an inverted L-shaped radiation strip. A defected ground structure is employed to obtain a good isolation performance, whereby the measured isolation between the antenna elements is observed to be larger than 23 dB. The measured total radiation efficiencies at 3.5 GHz and 4.9 GHz are 76.65% and 71.93%, respectively. Besides, the calculated envelope correlation coefficients (ECC) are less than 0.00125 and 0.01164 at the low-frequency and high-frequency bands, respectively. Furthermore, the specific absorption ratio (SAR) analysis of the antenna verifies that it qualifies for 5G terminals
RNAa Is Conserved in Mammalian Cells
Background: RNA activation (RNAa) is a newly discovered mechanism of gene activation triggered by small doublestranded RNAs termed ‘small activating RNAs ’ (saRNAs). Thus far, RNAa has only been demonstrated in human cells and is unclear whether it is conserved in other mammals. Methodology/Principal Findings: In the present study, we evaluated RNAa in cells derived from four mammalian species including nonhuman primates (African green monkey and chimpanzee), mouse, and rat. Previously, we identified saRNAs leading to the activation of E-cadherin, p21, and VEGF in human cells. As the targeted sequences are highly conserved in primates, transfection of each human saRNA into African green monkey (COS1) and chimpanzee (WES) cells also resulted in induction of the intended gene. Additional saRNAs targeting clinically relevant genes including p53, PAR4, WT1, RB1, p27, NKX3-1, VDR, IL2, and pS2 were also designed and transfected into COS1 and WES cells. Of the nine genes, p53, PAR4, WT1, and NKX3-1 were induced by their corresponding saRNAs. We further extended our analysis of RNAa into rodent cell types. We identified two saRNAs that induced the expression of mouse Cyclin B1 in NIH/3T3 and TRAMP C1 cells, which led to increased phosphorylation of histone H3, a downstream marker for chromosome condensation and entry into mitosis. We also identified two saRNAs that activated the expression of CXCR4 in primary rat adipose–derived stem cells. Conclusions/Significance: This study demonstrates that RNAa exists in mammalian species other than human. Our finding
Multiple Conformations of Phosphodiesterase-5: IMPLICATIONS FOR ENZYME FUNCTION AND DRUG DEVELOPMENT
Phosphodiesterase-5 (PDE5) is the target for sildenafil, vardenafil, and tadalafil, which are drugs for treatment of erectile dysfunction and pulmonary hypertension. We report here the crystal structures of a fully active catalytic domain of unliganded PDE5A1 and its complexes with sildenafil or icarisid II. These structures together with the PDE5A1-isobutyl-1-methylxanthine complex show that the H-loop ( residues 660-683) at the active site of PDE5A1 has four different conformations and migrates 7-35 angstrom upon inhibitor binding. In addition, the conformation of sildenafil reported herein differs significantly from those in the previous structures of chimerically hybridized or almost inactive PDE5. Mutagenesis and kinetic analyses confirm that the H-loop is particularly important for substrate recognition and that invariant Gly(659), which immediately precedes the H-loop, is critical for optimal substrate affinity and catalytic activity
Microenergy acoustic pulse therapy restores function and structure of pelvic floor muscles after simulated birth injury.
Economic analysis of rice fish culture
Meeting: National Rice Fish Farming Systems Symposium, 4-8 Oct. 1988, Wuxi, CNIn IDL-1614
Allogeneic and Xenogeneic Transplantation of Adipose-Derived Stem Cells in Immunocompetent Recipients Without Immunosuppressants
Mesenchymal stem cells (MSCs) are well known for their immunomodulatory capabilities. In particular, their immunosuppressive property is believed to permit their allogeneic or even xenogeneic transplantation into immunocompetent recipients without the use of immunosuppressants. Adipose-derived stem cell (ADSC), owing to its ease of isolation from an abundant tissue source, is a promising MSC for the treatment of a wide range of diseases. ADSC has been shown to lack major histocompatibility complex-II expression, and its immunosuppressive effects mediated by prostaglandin E2. Both preclinical and clinical studies have shown that allogeneic transplantation of ADSCs was able to control graft-versus-host disease. In regard to xenotransplantation a total of 27 preclinical studies have been published, with 20 of them performed with the investigators' intent. All 27 studies used ADSCs isolated from humans, possibly due to the wide availability of lipoaspirates. On the other hand, the recipients were mouse in 13 studies, rat in 11, rabbit in 2, and dog in 1. The targeted diseases varied greatly but all showed significant improvements after ADSC xenotransplantation. For clinical application in human medicine, ADSC xenotransplantation offers no obvious advantage over autotransplantation. But in veterinary medicine, xenotransplantation with porcine ADSC is a practical alternative to the costly and inconvenient autotransplantation
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Is CD34 truly a negative marker for mesenchymal stromal cells?
The prevailing school of thought is that mesenchymal stromal cells (MSC) do not express CD34, and this sets MSC apart from hematopoietic stem cells (HSC), which do express CD34. However, the evidence for MSC being CD34(-) is largely based on cultured MSC, not tissue-resident MSC, and the existence of CD34(-) HSC is in fact well documented. Furthermore, the Stro-1 antibody, which has been used extensively for the identification/isolation of MSC, was generated by using CD34(+) bone marrow cells as immunogen. Thus, neither MSC being CD34(-) nor HSC being CD34(+) is entirely correct. In particular, two studies that analyzed CD34 expression in uncultured human bone marrow nucleated cells found that MSC (BMSC) existed in the CD34(+) fraction. Several studies have also found that freshly isolated adipose-derived MSC (ADSC) express CD34. In addition, all of these ADSC studies and several other MSC studies have observed a disappearance of CD34 expression when the cells are propagated in culture. Thus the available evidence points to CD34 being expressed in tissue-resident MSC, and its negative finding being a consequence of cell culturing
Stem cells: novel players in the treatment of erectile dysfunction
Stem cells are defined by their capacity for both self-renewal and directed differentiation; thus, they represent great promise for regenerative medicine. Historically, stem cells have been categorized as either embryonic stem cells (ESCs) or adult stem cells (ASCs). It was previously believed that only ESCs hold the ability to differentiate into any cell type, whereas ASCs have the capacity to give rise only to cells of a given germ layer. More recently, however, numerous studies demonstrated the ability of ASCs to differentiate into cell types beyond their tissue origin. The aim of this review was to summarize contemporary evidence regarding stem cell availability, differentiation, and more specifically, the potential of these cells in the diagnosis and treatment of erectile dysfunction (ED) in both animal models and human research. We performed a search on PubMed for articles related to definition, localisation and circulation of stem cells as well as the application of stem cells in both diagnosis and treatment of ED. Strong evidence supports the concept that stem cell therapy is potentially the next therapeutic approach for ED. To date, a large spectrum of stem cells, including bone marrow mesenchymal stem cells, adipose tissue-derived stem cells and muscle-derived stem cells, have been investigated for neural, vascular, endothelial or smooth muscle regeneration in animal models for ED. In addition, several subtypes of ASCs are localized in the penis, and circulating endogenous stem cells can be employed to predict the outcome of ED and ED-related cardiovascular diseases.status: publishe
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Role of hydrogen sulfide in the physiology of penile erection.
Hydrogen sulfide (H(2)S), which is a well-known toxic gas, has recently been recognized as a biological messenger that plays an important role in physiological and pathophysiological conditions. Relatively high levels of H(2)S have been discovered in mammalian tissues. It is mainly synthesized by 2 enzymes, including cystathionine β-synthase and cystathionine γ-lysase, which utilize L-cysteine as substrate to produce H(2)S. H(2)S has been demonstrated to exhibit potent vasodilator activity both in vitro and in vivo by relaxing vascular smooth muscle. Recently, H(2)S has been discovered in penile tissue with smooth muscle relaxant effects. Furthermore, other effects of H(2)S could play a role in the physiology of erection. Understanding H(2)S in the physiology of erection might provide alternative erectile dysfunction strategies for those patients with poor or no response to type 5 phosphodiesterase inhibitors. This review intends to present the H(2)S pathway in penile tissue and the potential role of H(2)S in the physiology of erections
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