64 research outputs found
When a friend in Twitter is a friend in life
Twitter is a fast-growing online social network service (SNS) where users can “follow ” any other user to re-ceive his or her mini-blogs which are called “tweets”. In this paper, we study the problem of identifying a user’s off-line real-life social community, which we call the user’s Twitter off-line community, purely from ex-amining Twitter network structure. Based on obser-vations from our user-verified Twitter data and results from previous works, we propose three principles about Twitter off-line communities. Incorporating these prin-ciples, we develop a novel algorithm to iteratively dis-cover the Twitter off-line community based on a new way of measuring user closeness. According to ground truth provided by real Twitter users, our results demon-strate the effectiveness of our approach with both high precision and recall in most cases
Tubeimoside 1 Acts as a Chemotherapeutic Synergist via Stimulating Macropinocytosis
Macropinocytosis is a highly conserved endocytic process which characterizes the engulfment of extracellular fluid and its contents into cells via large, heterogeneous vacuoles known as macropinosomes. Tubeimoside-1 (TBM1) is a low toxic triterpenoid saponin extracted from a traditional Chinese herb Bolbostemma paniculatum (Maxim.). TBM1 stimulates a quick accumulation of numerous phase-lucent cytoplasmic vacuoles in multiple colorectal cancer (CRC) cell lines. These vacuoles can be termed as macropinosomes that efficiently engulf lucifer yellow. These vesicles are not overlaps with endocytic organelle tracers, such as ERTracker, LysoTracker and mitoTracker. These vacuoles induced by TBM1 partially incorporate into lysosomes. Transmission electron microscope indicates membrane ruffling to form lamellipodia. Protrusions collapse onto and then fuse back with the plasma membrane to generate these large endocytic vacuoles. Notably, TBM1 efficiently trafficks dextrans into heterotopic xenografts in vivo, thus provide consolidated evidence that the vacuolization can be mainly defined as macropinocytosis. TBM1 downregulates cell viability and increases PI-positive, but not highlighted Hoechst 33342-positive cells. TBM1 induced cell death can be ascribed as methuosis by hyperstimulation of macropinocytosis which can be compromised by amiloride derivative 5-(Nethyl-N-isopropyl). Light chain 3 II is recruited to these vesicles to stimulate macropinocytosis. The cell death and vacuoles can be significantly neutralized by chloroquine, but can not be the inhibited by 3-methyladenine. TBM1 can coordinate with 5-FU to exert toxicity reducing and efficacy enhancing effects in vivo by increasing the uptake of the latter without hepatic injury. In conclusion, TBM1 effectively induces in vitro and in vivo macropinocytosis which can traffick small molecules into CRC cells. It is an attractive drug transporter and can be harnessed as a chemotherapeutic synergist with translational potential
Um programa de ginástica para coronariopatas Coletânea de ExercĂcios Sugeridos
The acceleration of super-heavy ions (SHIs) from plasmas driven by ultrashort
(tens of femtoseconds) laser pulses is a challenging topic waiting for
breakthrough. The detecting and controlling of the ionization process, and the
adoption of the optimal acceleration scheme are crucial for the generation of
highly energetic SHIs. Here, we report the experimental results on the
generation of deeply ionized super-heavy ions (Au) with unprecedented energy of
1.2 GeV utilizing ultrashort laser pulses (22 fs) at the intensity of 10^22
W/cm2. A novel self-calibrated diagnostic method was developed to acquire the
absolute energy spectra and charge state distributions of Au ions abundant at
the charge state of 51+ and reaching up to 61+. The measured charge state
distributions supported by 2D particle-in-cell simulations serves as an
additional tool to inspect the ionization dynamics associated with SHI
acceleration, revealing that the laser intensity is the crucial parameter for
the acceleration of Au ions over the pulse duration. The use of double-layer
targets results in a prolongation of the acceleration time without sacrificing
the strength of acceleration field, which is highly favorable for the
generation of high-energy super heavy ions
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