139 research outputs found

    Broadband enhancement of thermal radiation

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    CAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOBroadband thermal radiation sources are critical for various applications including spectroscopy and electricity generation. However, due to the difficulty in simultaneously achieving high absorptivity and low thermal mass these sources are inefficient. We show a platform that enables one to obtain enhanced emission by coupling a thermal emitter to an optical cavity. We experimentally demonstrate broadband enhancement of thermal emission between lambda similar to 2 - 4.2 mu m using an inherently poor thermal emitter consisting of tens of nanometers thick SiC film with 10% emissivity (epsilon(S)(iC) similar to 0.1). We measure over twofold enhancement of total emission power over the entire spectral band and threefold enhancement of thermal emission over 3 to 3.4 mu m. Our platform has the potential to enable development of ideal blackbody sources operating at substantially lower heating powers.2712A818A828CAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOSem informaçãoSem informaçãoARPA-E IDEAS program (# DE-AR0000731), support from Brazilian agencies CAPES and FAPESP. Device fabrication & thin-film characterization at Cornell Nano-Scale Facility (NSF, # NNCI-1542081) and Cornell Center for Materials Research (NSF MRSEC, # DMR-1719875)

    11-keto-alpha-boswellic acid, a novel triterpenoid from Boswellia spp. with chemotaxonomic potential and antitumor activity against triple-negative breast cancer cells

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    Boswellic acids, and particularly 11-keto-boswellic acids, triterpenoids derived from the genus Boswellia (Burseraceae), are known for their anti-inflammatory and potential antitumor efficacy. Although boswellic acids generally occur as α-isomers (oleanane type) and β-isomers (ursane type), 11-keto-boswellic acid (KBA) was found only as the β-isomer, β-KBA. Here, the existence and natural occurrence of the respective α-isomer, 11-keto-α-boswellic acid (α-KBA), is demonstrated for the first time. Initially, α-KBA was synthesized and characterized by high-resolution mass spectrometry (HR-MS) and nuclear magnetic resonance (NMR) spectroscopy, and a highly selective, sensitive, and accurate high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) method was developed by Design of Experiments (DoE) using a pentafluorophenyl stationary phase. This method allowed the selective quantification of individual 11-keto-boswellic acids and provided evidence for α-KBA in Boswellia spp. oleogum resins. The contents of α-KBA as well as further boswellic acids and the composition of essential oils were used to chemotaxonomically classify 41 Boswellia oleogum resins from 9 different species. Moreover, α-KBA exhibited cytotoxicity against three treatment-resistant triple-negative breast cancer (TNBC) cell lines in vitro and also induced apoptosis in MDA-MB-231 xenografts in vivo. The respective β-isomer and the acetylated form demonstrate higher cytotoxic efficacies against TNBC cells. This provides further insights into the structure-activity relationship of boswellic acids and could support future developments of potential anti-inflammatory and antitumor drugs

    SAMHD1 restricts HIV-1 infection in dendritic cells (DCs) by dNTP depletion, but its expression in DCs and primary CD4+ T-lymphocytes cannot be upregulated by interferons

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    BACKGROUND: SAMHD1 is an HIV-1 restriction factor in non-dividing monocytes, dendritic cells (DCs), macrophages, and resting CD4(+) T-cells. Acting as a deoxynucleoside triphosphate (dNTP) triphosphohydrolase, SAMHD1 hydrolyzes dNTPs and restricts HIV-1 infection in macrophages and resting CD4(+) T-cells by decreasing the intracellular dNTP pool. However, the intracellular dNTP pool in DCs and its regulation by SAMHD1 remain unclear. SAMHD1 has been reported as a type I interferon (IFN)-inducible protein, but whether type I IFNs upregulate SAMHD1 expression in primary DCs and CD4(+) T-lymphocytes is unknown. RESULTS: Here, we report that SAMHD1 significantly blocked single-cycle and replication-competent HIV-1 infection of DCs by decreasing the intracellular dNTP pool and thereby limiting the accumulation of HIV-1 late reverse transcription products. Type I IFN treatment did not upregulate endogenous SAMHD1 expression in primary DCs or CD4(+) T-lymphocytes, but did in HEK 293T and HeLa cell lines. When SAMHD1 was over-expressed in these two cell lines to achieve higher levels than that in DCs, no HIV-1 restriction was observed despite partially reducing the intracellular dNTP pool. CONCLUSIONS: Our results suggest that SAMHD1-mediated reduction of the intracellular dNTP pool in DCs is a common mechanism of HIV-1 restriction in myeloid cells. Endogenous expression of SAMHD1 in primary DCs or CD4(+) T-lymphocytes is not upregulated by type I IFNs

    The taxonomic and functional biogeographies of phytoplankton and zooplankton communities across boreal lakes

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    Dataset for the study: The taxonomic and functional biogeographies of phytoplankton and zooplankton communities across boreal lakes published in Peer Community in Ecolog

    tDCS Task-Oriented Approach Improves Function in Individuals With Fibromyalgia Pain. A Pilot Study

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    Fibromyalgia (FM) is a complex pain syndrome accompanied by physical disability and loss of daily life activities. Evidences suggest that modulation of the primary motor cortex (M1) by transcranial direct current stimulation (tDCS) improves functional physical capacity in chronic pain conditions. However, the gain on physical function in people living with FM receiving tDCS is still unclear. This study aimed to evaluate whether the tDCS task-oriented approach improves function and reduces pain in a single cohort of 10 FM. A total of 10 women with FM (60.4 ± 15.37 years old) were enrolled in an intervention including anodal tDCS delivered on M1 (2 mA from a constant stimulator for 20 min); simultaneously they performed a functional task. The anode was placed on the contralateral hemisphere of the dominant hand. Outcome assessments were done before the stimulation, immediately after stimulation and 30 min after the end of tDCS. The same protocol was applied in subsequent sessions. A total of five consecutive days of tDCS were completed. The main outcomes were the number of repetitions achieved and time in active practice to evaluate functional physical task performance such as intensity of the pain (visual analog scale) and level of fatigue (Borg scale). After 5 days of tDCS, the number of repetitions achieved significantly increased by 49% (p = 0.012). No change was observed in active practice time. No increase in pain was observed despite the mobility of the painful parts of the body. These results are encouraging since an increase in pain due to the mobilization of painful body parts could have been observed at the end of the 5th day of the experiment. These results support the use of tDCS in task-based rehabilitation

    Viability of Bifidobacterium longum in cheddar cheese curd during manufacture and storage: effect of microencapsulation and point of inoculation

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    International audienceThe goal of this study was to assess the effect of methods of inoculation on the viability of probiotic bacteria during cheddar cheese manufacture as well as their stability during storage. Bifidobacterium longum ATCC 15708 was freeze-dried and microencapsulated by spray-coating. The effect of inoculation of free whole cell or microencapsulated cells at three points during manufacture (milk before renneting, at cheddaring or at salting) on the viable counts in cheese and whey was investigated. Microencapsulation had no effect on viable counts, chemical parameters (lactose, lactic acid, total nitrogen, nitrogen soluble in TCA, moisture) or sensory properties during manufacturing or storage of the fresh cheeses for 14 days. Inoculation of the bifidobacteria in milk before renneting resulted in higher viable counts in comparison to other points of inoculation. Bifidobacteria added at the salting step, which survived pressing, were subsequently more stable during storage than those inoculated in milk. The stability of B. longum 15708 during storage was greater in the pressed cheeses that in the free curds. The results of this study provides technological data for cheese makers on the optimum point of inoculation as well as the benefit of pressing the curds in order to ensure high levels of probiotics in fresh cheddar cheese
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