799 research outputs found

    High Performance Antenna System in MIMO Configuration for 5G Wireless Communications Over Sub-6 GHz Spectrum

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    This paper presents a high-performance multiple input and multiple output (MIMO) antenna comprising 2 × 2 configuration of radiating elements that is designed for sub-6 GHz applications. The proposed MIMO antenna employs four identical radiating elements. High isolation between the radiating elements and therefore reduced mutual coupling is achieved by spatially arranging the radiating elements in an orthogonal configuration. Also, a novel frequency selective surface (FSS) was employed to increase the gain of the MIMO antenna over a wide bandwidth from 3 to 6 GHz. This was achieved by locating the FSS above the antenna at a certain height. The FSS essentially enhanced the antenna's directivity, reduced back lobe radiation and mutual coupling. The antenna was fabricated on a standard Rogers RT Duroid 5880 dielectric substrate with a 0.8 mm thickness. The overall dimension of the MIMO antenna is 50 × 50 × 12.5 mm3 and it operates from 3.8 to 6 GHz, which corresponds to a fractional bandwidth of 41%. The proposed MIMO antenna has a measured peak gain of 4.8 dBi and inter radiation element isolation >20 dB. Its envelope correlation coefficient is <0.1 and diversity gain >9.9 (dB). These characteristics make the proposed MIMO antenna system suitable for 5G communication systems

    Sequences of Willmore surfaces

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    In this paper we develop the theory of Willmore sequences for Willmore surfaces in the 4-sphere. We show that under appropriate conditions this sequence has to terminate. In this case the Willmore surface either is the twistor projection of a holomorphic curve into complex projective space or the inversion of a minimal surface with planar ends in 4-space. These results give a unified explanation of previous work on the characterization of Willmore spheres and Willmore tori with non-trivial normal bundles by various authors.Comment: 10 page

    A double-blind placebo controlled trial into the impacts of HMB supplementation and exercise on free-living muscle protein synthesis, muscle mass and function, in older adults

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    Age-related sarcopenia and dynapenia are associated with frailty and metabolic diseases. Resistance exercise training (RET) adjuvant to evidence-based nutritional intervention(s) have been shown as mitigating strategies. Given that \u3b2-hydroxy-\u3b2-methyl-butyrate (HMB) supplementation during RET improves lean body mass in younger humans, and that we have shown that HMB acutely stimulates muscle protein synthesis (MPS) and inhibits breakdown; we hypothesized that chronic supplementation of HMB free acid (HMB-FA) would enhance MPS and muscle mass/function in response to RET in older people. We recruited 16 healthy older men (Placebo (PLA): 68.5 \ub1 1.0 y, HMB-FA: 67.8 \ub1 1.15 y) for a randomised double-blind-placebo controlled trial (HMB-FA 3 7 1 g/day vs. PLA) involving a 6-week unilateral progressive RET regime (6 7 8 repetitions, 75% 1-RM, 3 \ub7 wk 121). Deuterium oxide (D2O) dosing was performed over the first two weeks (0\u20132 wk) and last two weeks (4\u20136 wk) with bilateral vastus lateralis (VL) biopsies at 0\u20132 and 4\u20136 wk (each time 75 \ub1 2 min after a single bout of resistance exercise (RE)) for quantification of early and later MPS responses and post-RE myogenic gene expression. Thigh lean mass (TLM) was measured by DXA, VL thickness and architecture (fibre length and pennation angle) by ultrasound at 0/3/6 wk, and strength by knee extensor 1-RM testing and MVC by isokinetic dynamometry (approx. every 10 days). RET induced strength increases (1-RM) in the exercised leg of both groups (398 \ub1 22N to 499 \ub1 30N HMB-FA vs. 396 \ub1 29N to 510 \ub1 43N PLA (both P < 0.05)). In addition, maximal voluntary contraction (MVC) also increased (179 \ub1 12 Nm to 203 \ub1 12 Nm HMB-FA vs. 185 \ub1 10 Nm to 217 \ub1 11 Nm PLA (both P < 0.05); with no group differences. VL muscle thickness increased significantly in the exercised leg in both groups, with no group differences. TLM (by DXA) rose to significance only in the HMB-FA group (by 5.8%\u20135734 \ub1 245 g p = 0.015 vs. 3.0% to 5644 \ub1 323 g P = 0.06 in PLA). MPS remained unchanged in the untrained legs (UT) 0\u20132 weeks being 1.06 \ub1 0.08%.d 121 (HMB-FA) and 1.14 \ub1 0.09%.d 121 (PLA), the trained legs (T) exhibited increased MPS in the HMB-FA group only at 0\u20132-weeks (1.39 \ub1 0.10%.d 121, P < 0.05) compared with UT: but was not different at 4\u20136-weeks: 1.26 \ub1 0.05%.d 121. However, there were no significant differences in MPS between the HMB-FA and PLA groups at any given time point and no significant treatment interaction observed. We also observed significant inductions of c-Myc gene expression following each acute RE bout, with no group differences. Further, there were no changes in any other muscle atrophy/hypertrophy or myogenic transcription factor genes we measured. RET with adjuvant HMB-FA supplements in free-living healthy older men did not enhance muscle strength or mass greater than that of RET alone (PLA). That said, only HMB-FA increased TLM, supported by early increases in chronic MPS. As such, chronic HMB-FA supplementation may result in long term benefits in older males, however longer and larger studies may be needed to fully determine the potential effects of HMB-FA supplementation; translating to any functional benefit

    Subsurface structural investigation based on seismic data of the north-eastern Potwar basin, Pakistan

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    1258-1268The north-eastern Potwar is present in the foothills of Himalayas on the northern boundary of the Indian Plate and is filled by the Infra-Cambrian to Pliocene sedimentation. The area is affected by the regional structures of the Potwar and the Salt-Range Structures, such as the North Potwar Deformed Zone (NPDZ), the Soan Syncline, the Main Boundary Thrust (MBT) and the Jhelum Fault. Due to complex tectonic-structural framework, it is extremely significant to understand the subsurface structural mechanisms for further hydrocarbons exploration. The 2D seismic data was acquired in the NE-Potwar in the Rawat area is used for this purpose. The current study helps to present rigorous and mechanically feasible structure understanding of the Rawat and associated local structures of the area in the context of the Sub-Himalayas. The study area mainly comprises on the eastern Potwar with tight anticlines and wide synclines with associated thrusts showing collisional regime of the Himalayan Fold and the thrust belt. The structural interpretation and restoration of paleo-section provide a mechanically feasible model for the Rawat area. The interpretation of seismic data shows that this area is associated with conjugate faults and a triangle zone. The results of this study help us to develop understanding in geological history, structural overprint and future leads for hydrocarbons in this geological province

    Defective extracellular matrix remodeling in brown adipose tissue is associated with fibro-inflammation and reduced diet-induced thermogenesis.

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    The relevance of extracellular matrix (ECM) remodeling is reported in white adipose tissue (AT) and obesity-related dysfunctions, but little is known about the importance of ECM remodeling in brown AT (BAT) function. Here, we show that a time course of high-fat diet (HFD) feeding progressively impairs diet-induced thermogenesis concomitantly with the development of fibro-inflammation in BAT. Higher markers of fibro-inflammation are associated with lower cold-induced BAT activity in humans. Similarly, when mice are housed at thermoneutrality, inactivated BAT features fibro-inflammation. We validate the pathophysiological relevance of BAT ECM remodeling in response to temperature challenges and HFD using a model of a primary defect in the collagen turnover mediated by partial ablation of the Pepd prolidase. Pepd-heterozygous mice display exacerbated dysfunction and BAT fibro-inflammation at thermoneutrality and in HFD. Our findings show the relevance of ECM remodeling in BAT activation and provide a mechanism for BAT dysfunction in obesity

    The Risk of Recurrence in Breast Cancer Patients Treated with Tamoxifen: Polymorphisms of CYP2D6 and ABCB1

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    CYP2D6 plays a major role in the metabolism of tamoxifen, and polymorphism of Pglycoprotein has been associated with resistance of many drug therapies. This study investigates the clinical impact of genetic variants of CYP2D6 and ABCB1 in breast cancer patients treated with tamoxifen. Blood samples from 95 breast cancer patients treated with tamoxifen were collected and genotyped for CYP2D6 and ABCB1 variants using allele-specific PCR method. Recurrence risks were calculated using Kaplan–Meier analysis and compared using the log-rank test. Patients carrying CYP2D6*10/*10 and heterozygous null allele (IM) showed higher risks of developing recurrence and metastasis (OR 13.14; 95% CI 1.57–109.94; P=0.004) than patients with CYP2D6*1/*1 and *1/*10 genotypes. Patients with homozygous CC genotypes of ABCB1 C3435T showed a shorter time to recurrence. Patients who were CYP2D6 IM and homozygous CC genotype of C3435T have statistically significant higher risks of recurrence (P=0.002). Similarly, median time to recurrence in these patients was only 12 months (95% CI=0.79–23.2) compared to those without this combination which was 48 months (95% CI=14.7–81.2). Patients with CYP2D6 IM and homozygous CC genotype of ABCB1 C3435T have shorter times to recurrence. The results confirmed the findings of previous studies and support FDA recommendation to perform pre-genotyping in patients before the choice of therapy is determined in breast cancer patients

    Unmodified Titanium Dioxide Nanoparticles as a potential contrast agent in photon emission computed tomography

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    Highly crystalline titanium dioxide nanoparticles (TiO2 -NPs) are synthesized via a simple hydrothermal technique. After structural and compositional analysis, the as-synthesized unmodified TiO2 -NPs are tested for improvement in two modes of kilovoltage radiation therapy and singlephoton emission computed tomography (SPECT)/computed tomography (CT). Our results show that the unmodified TiO2 -NPs provide an observable enhancement in CT scan image contrast ranging from 0 ± 3 HU (without NPs) to 283.7 ± 3 HU (0.23 g/mL). TiO2 -NPs has excellent biocompatibility, selective uptake at target sites, and reduced toxicity. The unmodified TiO2 -NPs as a contrast agent can significantly improve the existing methods of diagnosing and treating cancer

    Use of alcoholic beverages in VA medical centers

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    BACKGROUND: Benzodiazepines are the first-line choice for the treatment of alcohol withdrawal syndrome. However, several hospitals continue to provide alcoholic beverages through their formulary for the treatment of alcohol withdrawal. While there are data on the prevalence of this practice in academic medical centers, there are no data on the availability of alcoholic beverages at the formularies of the hospitals operated by the department of Veteran's Affairs. METHODS: In this study, we surveyed the Pharmacy managers at 112 Veterans' Affairs Medical Centers (VAMCs) to ascertain the availability of alcohol on the VAMC formularies, and presence or lack of a policy on the use of alcoholic beverages in their VA Medical Center. RESULTS: Of the pharmacy directors contacted, 81 responded. 8 did not allow their use, while 20 allowed their use. There was a lack of a consistent policy across the VA medical centers on availability and use of alcoholic beverages for the treatment of alcohol withdrawal syndrome. CONCLUSION: There is lack of uniform policy on the availability of alcoholic beverages across the VAMCs, which may create potential problems with difference in the standards of care

    Polymorphisms in NFkB, PXR, LXR and risk of colorectal cancer in a prospective study of Danes

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    <p>Abstract</p> <p>Background</p> <p>Transcription factors and nuclear receptors constitute a link between exposure to heterocyclic amines and polycyclic aromatic hydrocarbons from meat and tobacco smoke and colorectal cancer (CRC) risk. The aim of this study was to investigate if polymorphisms in nuclear factor kappa-B, pregnane X receptor, and liver X receptor were associated with risk of CRC, and to investigate possible interactions with lifestyle factors such as smoking, meat consumption, and NSAID use.</p> <p>Methods</p> <p>The polymorphisms nuclear factor kappa-B (<it>NFkB, NFKB1) </it>-94 insertion/deletion ATTG (rs28362491), pregnane X receptor (<it>PXR, NR1I2) </it>A-24381C (rs1523127), C8055T (rs2276707), A7635G (rs6785049), liver X receptor (<it>LXR-β, NR1H3) </it>C-rs1405655T, T-rs2695121C were assessed together with lifestyle factors in a nested case-cohort study of 378 CRC cases and 756 random participants from the Danish prospective Diet, Cancer and Health study of 57,053 persons.</p> <p>Results</p> <p>Carriers of <it>NFkB </it>-94deletion were at 1.45-fold higher risk of CRC than homozygous carriers of the insertion allele (incidence rate ratio (IRR) = 1.45, 95% confidence interval (95% CI): 1.10-1.92). There was interaction between this polymorphism and intake of red and processed meat in relation to CRC risk. Carriers of <it>NFkB </it>-94deletion were at 3% increased risk pr 25 gram meat per day (95% CI: 0.98-1.09) whereas homozygous carriers of the insertion were not at increased risk (p for interaction = 0.03). <it>PXR </it>and <it>LXR </it>polymorphisms were not associated with CRC risk. There was no interaction between use of nonsteroid antiinflammatory drugs (NSAID) or smoking status and <it>NFkB</it>, <it>PXR </it>or <it>LXR </it>polymorphisms.</p> <p>Conclusions</p> <p>A polymorphism in <it>NFkB </it>was associated with CRC risk and there was interaction between this polymorphism and meat intake in relation to CRC risk. This study suggests a role for NFkB in CRC aetiology.</p
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