2,406 research outputs found

    Saccharomyces cerevisiae Est3p dimerizes in vitro and dimerization contributes to efficient telomere replication in vivo

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    In Saccharomyces cerevisiae at least five genes, EST1, EST2, EST3, TLC1 and CDC13, are required for telomerase activity in vivo. The telomerase catalytic subunit Est2p and telomerase RNA subunit Tlc1 constitute the telomerase core enzyme. Est1p and Est3p are the other subunits of telomerase holoenzyme. In order to dissect the function of Est3p in telomere replication, we over-expressed and purified recombinant wild-type and mutant Est3 proteins. The wild-type protein, as well as the K71A, E104A and T115A mutants were able to dimerize in vitro, while the Est3p-D49A, -K68A or -D166A mutant showed reduced ability to dimerize. Mutations in Est3p that decreased dimerization also appeared to cause telomere shortening in vivo. Double point mutation of Est3p-D49A-K68A and single point mutation of Est3p-K68A showed similar telomere shortening, suggesting that the K68 residue might be more important for telomerase activity. The ectopic co-expression of K71A or T115A mutant with wild-type Est3p using centromere plasmids caused telomere shortening, while co-expression of the D49A, K68A, D86A or F103A mutants with wild-type Est3p had no effect on telomere length regulation. These data suggested that dimerization is important for Est3p function in vivo

    Passive Human Sensing Enhanced by Reconfigurable Intelligent Surface: Opportunities and Challenges

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    Reconfigurable intelligent surfaces (RISs) have flexible and exceptional performance in manipulating electromagnetic waves and customizing wireless channels. These capabilities enable them to provide a plethora of valuable activity-related information for promoting wireless human sensing. In this article, we present a comprehensive review of passive human sensing using radio frequency signals with the assistance of RISs. Specifically, we first introduce fundamental principles and physical platform of RISs. Subsequently, based on the specific applications, we categorize the state-of-the-art human sensing techniques into three types, including human imaging,localization, and activity recognition. Meanwhile, we would also investigate the benefits that RISs bring to these applications. Furthermore, we explore the application of RISs in human micro-motion sensing, and propose a vital signs monitoring system enhanced by RISs. Experimental results are presented to demonstrate the promising potential of RISs in sensing vital signs for manipulating individuals. Finally, we discuss the technical challenges and opportunities in this field

    Assembly strategies for rubber-degrading microbial consortia based on omics tools

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    Numerous microorganisms, including bacteria and fungus, have been identified as capable of degrading rubber. Rubber biodegradation is still understudied due to its high stability and the lack of well-defined pathways and efficient enzymes involved in microorganism metabolism. However, rubber products manufacture and usage cause substantial environmental issues, and present physical-chemical methods involve dangerous chemical solvents, massive energy, and trash with health hazards. Eco-friendly solutions are required in this context, and biotechnological rubber treatment offers considerable promise. The structural and functional enzymes involved in poly (cis-1,4-isoprene) rubber and their cleavage mechanisms have been extensively studied. Similarly, novel bacterial strains capable of degrading polymers have been investigated. In contrast, relatively few studies have been conducted to establish natural rubber (NR) degrading bacterial consortia based on metagenomics, considering process optimization, cost effective approaches and larger scale experiments seeking practical and realistic applications. In light of the obstacles encountered during the constructing NR-degrading consortia, this study proposes the utilization of multi-omics tools to discern the underlying mechanisms and metabolites of rubber degradation, as well as associated enzymes and effective synthesized microbial consortia. In addition, the utilization of omics tool-based methods is suggested as a primary research direction for the development of synthesized microbial consortia in the future

    Feeding a low-protein maternal diet affects qinghai bamei piglet jejunal structure and microbial function response

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    This experiment investigated the impacts of feeding a maternal low-CP concentration diet having iso-essential amino acids on newborn suckling piglet"s intestinal microbial composition and function. Forty randomly selected purebred Bamei sows were divided into two groups and fed a low dietary CP (12%, LP) or a normal CP (14%, CON) diet, respectively, but formulated to contain similar (iso-) essential amino acid concentrations per current recommendations. At 21 days, 12 piglets were randomly selected from each treatment and euthanized with jejunum content samples collected. The 16S rRNA gene sequencing was combined as an integrated approach for evaluating the functional impact of maternal CP concentrations on piglet intestinal microbiome. Even though piglets demonstrated similar 0 to 21 d ADG among treatments, the jejunum relative weight, villus width, crypt depth and muscular thickness were increased (P<0.05), while villus height, and villus height/crypt depth were reduced (P<0.05) for the material LP compared to the maternal fed CON diet. Maternal CP concentrations can modify the intestinal microbial composition of Bamei suckling piglets. The relative abundances of the bacterial species Escherichia-Shigella, Actinobacillus, Clostridium_sensu_stricto_1, Veillonella, and Turicibacter were increased (P<0.05) in the maternal LP fed diet compared with the maternal fed CON diet microbiota metabolites. Overall, LP diet contributed to improve piglet intestinal histomorphology, microbial composition and function

    A low-crosstalk double-side addressing system using acousto-optic deflectors for atomic ion qubits

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    The ability to individually and agilely manipulate qubits is crucial for the scalable trapped-ion quantum information processing. A plethora of challenging proposals have been demonstrated with the utilization of optical addressing systems, in which single ions is addressed exclusively by individual laser beam. However, crosstalk error in optical addressing systems limits the gate fidelity, becoming an obstacle to quantum computing, especially quantum error correction. In this work, we demonstrate a low-crosstalk double-side addressing system based on a pair of acousto-optic deflectors (AODs). The AODs addressing method can flexibly and parallelly address arbitrary ions between which the distance is variable in a chain. We employ two 0.4~NA objective lenses in both arms of the Raman laser and obtain a beam waist of 0.95~μm\mu\mathrm{m}, resulting in a Rabi rate crosstalk as low as 6.32×1046.32\times10^{-4} when the neighboring ion separation is about 5.5~μm\mu\mathrm{m}. This agile and low-crosstalk double-side addressing system is promising for higher-fidelity gates and the practical application of the quantum error correction

    Deletion of cytosolic gating ring decreases gate and voltage sensor coupling in BK channels

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    Large conductance Ca(2+)-activated K(+) channels (BK channels) gate open in response to both membrane voltage and intracellular Ca(2+). The channel is formed by a central pore-gate domain (PGD), which spans the membrane, plus transmembrane voltage sensors and a cytoplasmic gating ring that acts as a Ca(2+) sensor. How these voltage and Ca(2+) sensors influence the common activation gate, and interact with each other, is unclear. A previous study showed that a BK channel core lacking the entire cytoplasmic gating ring (Core-MT) was devoid of Ca(2+) activation but retained voltage sensitivity (Budelli et al. 2013. Proc. Natl. Acad. Sci. USA. http://dx.doi.org/10.1073/pnas.1313433110). In this study, we measure voltage sensor activation and pore opening in this Core-MT channel over a wide range of voltages. We record gating currents and find that voltage sensor activation in this truncated channel is similar to WT but that the coupling between voltage sensor activation and gating of the pore is reduced. These results suggest that the gating ring, in addition to being the Ca(2+) sensor, enhances the effective coupling between voltage sensors and the PGD. We also find that removal of the gating ring alters modulation of the channels by the BK channel’s β1 and β2 subunits

    Spatial beam self-cleaning in bi-tapered multimode fibers

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    We report the spatial beam self-cleaning in bi-tapered conventional multimode fibers (MMFs) with different tapered lengths. Through the introduction of the bi-tapered structure in MMFs, the input beam with poor beam quality from a high-power fiber laser can be converted to a centered, bell-shaped beam in a short length, due to the strengthened nonlinear modes coupling. It is found that the bi-tapered MMF with longer tapered length at the same waist diameter shows better beam self-cleaning effect and larger spectral broadening. The obtained results offer a new method to improve the beam quality of high-power laser at low cost. Besides, it may be interesting for manufacturing bi-tapered MMF-based devices to obtain the quasi-fundamental mode beam in spatiotemporal mode-locked fiber lasers

    Quantitative Proteomic Study of Human Lung Squamous Carcinoma and Normal Bronchial Epithelial Acquired by Laser Capture Microdissection

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    Objective. To investigate the differential protein profile of human lung squamous carcinoma (HLSC) and normal bronchial epithelium (NBE) and provide preliminary results for further study to explore the carcinogenic mechanism of HLSC. Methods. Laser capture microdissection (LCM) was used to purify the target cells from 10 pairs of HLSC tissues and their matched NHBE, respectively. A stable-isotope labeled strategy using iTRAQ, followed by 2D-LC/Q-STAR mass spectrometry, was performed to separate and identify the differential expression proteins. Results. A total of 96 differential expression proteins in the LCM-purified HLSC and NBE were identified. Compared with NBE, 49 proteins were upregulated and 47 proteins were downregulated in HLSC. Furthermore, the expression levels of the differential proteins including HSPB1, CKB, SCCA1, S100A8, as well as S100A9 were confirmed by western blot and tissue microarray and were consistent with the results of quantitative proteomics. Conclusion. The different expression proteins in HLSC will provide scientific foundation for further study to explore the carcinogenic mechanism of HLSC

    Systematic Review of Randomized Clinical Trials of Acupressure Therapy for Primary Dysmenorrhea

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    The evidence of acupressure is limited in the management of dysmenorrhea. To evaluate the efficacy of acupressure in the treatment of primary dysmenorrhea based on randomized controlled trials (RCTs), we searched MEDLINE, the Chinese Biomedical Database (CBM), and the Cochrane Central Register of Controlled Trials (CENTRAL) databases from inception until March 2012. Two reviewers independently selected articles and extracted data. Statistical analysis was performed with RevMan 5.1 software. Eight RCTs were identified from the retrieved 224 relevant records. Acupressure improved pain measured with VAS (−1.41 cm 95% CI [−1.61, −1.21]), SF-MPQ at the 3-month followup (WMD −2.33, 95% CI [−4.11, −0.54]) and 6-month followup (WMD −4.67, 95% CI [−7.30, −2.04]), and MDQ at the 3-month followup (WMD −2.31, 95% CI [−3.74, −0.87]) and 6-month followup (WMD −4.67, 95% CI [−7.30, −2.04]). All trials did not report adverse events. These results were limited by the methodological flaws of trials
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