69 research outputs found
Tentative Plan of Pneumatic Silt Scouring on Yellow River
Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv
Ionic effect on combing of single DNA molecules and observation of their force-induced melting by fluorescence microscopy
Molecular combing is a powerful and simple method for aligning DNA molecules
onto a surface. Using this technique combined with fluorescence microscopy, we
observed that the length of lambda-DNA molecules was extended to about 1.6
times their contour length (unextended length, 16.2 micrometers) by the combing
method on hydrophobic polymethylmetacrylate (PMMA) coated surfaces. The effects
of sodium and magnesium ions and pH of the DNA solution were investigated.
Interestingly, we observed force-induced melting of single DNA molecules.Comment: 12 page
P2X4 forms functional ATP-activated cation channels on lysosomal membranes regulated by luminal pH.
P2X receptors are commonly known as plasma membrane cation channels involved in a wide variety of cell functions. The properties of these channels have been extensively studied on the plasma membrane. However, studies in amoeba suggest that P2X receptors are also present intracellularly and involved in vesicle fusion with the plasma membrane. Recently, it was shown that in addition to plasma membrane expression, mammalian P2X4 was also localized intracellularly in lysosomes. However, it was not clear whether the lysosomal P2X4 receptors function as channels and how they are activated and regulated. In this paper, we show that both P2X4 and its natural ligand, ATP, are enriched in lysosomes of COS1 and HEK293 cells. By directly recording membrane currents from enlarged lysosomal vacuoles, we demonstrated that lysosomal P2X4 formed channels activated by ATP from the luminal side in a pH-dependent manner. While the acidic pH at the luminal side inhibited P2X4 activity, increasing the luminal pH in the presence of ATP caused P2X4 activation. We further showed that, as for the plasma membrane P2X4, the lysosomal P2X4 was potentiated by ivermectin but insensitive to suramin and PPADS, and it permeated the large cation N-methyl-d-glucamine upon activation. Our data suggest that P2X4 forms functional ATP-activated cation channels on lysosomal membranes regulated by luminal pH. Together with the reported fusion effect of intracellular P2X in lower organisms, we speculate that the lysosome-localized P2X4 may play specific roles in membrane trafficking of acidic organelles in mammalian cells
Dual-comb spectroscopy over 100km open-air path
Satellite-based greenhouse gases (GHG) sensing technologies play a critical
role in the study of global carbon emissions and climate change. However, none
of the existing satellite-based GHG sensing technologies can achieve the
measurement of broad bandwidth, high temporal-spatial resolution, and high
sensitivity at the same time. Recently, dual-comb spectroscopy (DCS) has been
proposed as a superior candidate technology for GHG sensing because it can
measure broadband spectra with high temporal-spatial resolution and high
sensitivity. The main barrier to DCS's display on satellites is its short
measurement distance in open air achieved thus far. Prior research has not been
able to implement DCS over 20 km of open-air path. Here, by developing a
bistatic setup using time-frequency dissemination and high-power optical
frequency combs, we have implemented DCS over a 113 km turbulent horizontal
open-air path. Our experiment successfully measured GHG with 7 nm spectral
bandwidth and a 10 kHz frequency and achieved a CO2 sensing precision of <2 ppm
in 5 minutes and <0.6 ppm in 36 minutes. Our results represent a significant
step towards advancing the implementation of DCS as a satellite-based
technology and improving technologies for GHG monitoringComment: 24 pages, 6 figure
Broad targeting of resistance to apoptosis in cancer
Apoptosis or programmed cell death is natural way of removing aged cells from the body. Most of the anti-cancer therapies trigger apoptosis induction and related cell death networks to eliminate malignant cells. However, in cancer, de-regulated apoptotic signaling, particularly the activation of an anti-apoptotic systems, allows cancer cells to escape this program leading to uncontrolled proliferation resulting in tumor survival, therapeutic resistance and recurrence of cancer. This resistance is a complicated phenomenon that emanates from the interactions of various molecules and signaling pathways. In this comprehensive review we discuss the various factors contributing to apoptosis resistance in cancers. The key resistance targets that are discussed include (1) Bcl-2 and Mcl-1 proteins; (2) autophagy processes; (3) necrosis and necroptosis; (4) heat shock protein signaling; (5) the proteasome pathway; (6) epigenetic mechanisms; and (7) aberrant nuclear export signaling. The shortcomings of current therapeutic modalities are highlighted and a broad spectrum strategy using approaches including (a) gossypol; (b) epigallocatechin-3-gallate; (c) UMI-77 (d) triptolide and (e) selinexor that can be used to overcome cell death resistance is presented. This review provides a roadmap for the design of successful anti-cancer strategies that overcome resistance to apoptosis for better therapeutic outcome in patients with cancer
Real-time Monitoring for the Next Core-Collapse Supernova in JUNO
Core-collapse supernova (CCSN) is one of the most energetic astrophysical
events in the Universe. The early and prompt detection of neutrinos before
(pre-SN) and during the SN burst is a unique opportunity to realize the
multi-messenger observation of the CCSN events. In this work, we describe the
monitoring concept and present the sensitivity of the system to the pre-SN and
SN neutrinos at the Jiangmen Underground Neutrino Observatory (JUNO), which is
a 20 kton liquid scintillator detector under construction in South China. The
real-time monitoring system is designed with both the prompt monitors on the
electronic board and online monitors at the data acquisition stage, in order to
ensure both the alert speed and alert coverage of progenitor stars. By assuming
a false alert rate of 1 per year, this monitoring system can be sensitive to
the pre-SN neutrinos up to the distance of about 1.6 (0.9) kpc and SN neutrinos
up to about 370 (360) kpc for a progenitor mass of 30 for the case
of normal (inverted) mass ordering. The pointing ability of the CCSN is
evaluated by using the accumulated event anisotropy of the inverse beta decay
interactions from pre-SN or SN neutrinos, which, along with the early alert,
can play important roles for the followup multi-messenger observations of the
next Galactic or nearby extragalactic CCSN.Comment: 24 pages, 9 figure
RecQ Helicase-catalyzed DNA Unwinding Detected by Fluorescence Resonance Energy Transfer
International audienc
Genome-Wide Identification and Expression Analysis of the Dof Transcription Factor Gene Family in Gossypium hirsutum L.
Gossypium hirsutum L. is a worldwide economical crop; however, premature leaf senescence reduces its production and quality which is regulated by stresses, hormones, and genes. DNA binding with the one zinc finger (Dof) transcription factors (TFs) participate widely in plant development and responses to biotic and abiotic stresses, but there have been few reports of these TFs in cotton. Here, we perform a genome-wide study of G. Hirsutum L. Dof (GhDof) genes and analyze their phylogeny, duplication, and expression. In total, 114 GhDof genes have been identified and classified into nine subgroups (A, B1, B2.2, B2.1, C1, C2.1, C2.2, D1, and D2) based on phylogenetic analysis. An MCScanX analysis showed that the GhDof genes expanded due to segmental duplications. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis showed that GhDofD9.6 was not only differentially expressed between CCRI10 (with premature senescence) and Liao4086 (without premature senescence) but also responded to salinity stress; GhDofA5.7, GhDofA7.4, GhDofA8.2, GhDof11.1, GhDofD7.2, and GhDofD11.3 signfificantly responded to cold (4 °C) stress. This work lays the foundation for further analysis of the function of GhDof genes in G. hirsutum, which will be helpful for improving the production and quality of cotton
Escherichia coli RecQ Is a Rapid, Efficient, and Monomeric Helicase
International audienc
- …