2,329 research outputs found
Ultrasound Capsule Endoscopy With a Mechanically Scanning Micro-ultrasound:A Porcine Study
Wireless capsule endoscopy has been used for the clinical examination of the gastrointestinal (GI) tract for two decades. However, most commercially available devices only utilise optical imaging to examine the GI wall surface. Using this sensing modality, pathology within the GI wall cannot be detected. Micro-ultrasound (μUS) using high-frequency (>20 MHz) ultrasound can provide a means of transmural or cross-sectional image of the GI tract. Depth of imaging is approximately 10 mm with a resolution of between 40–120 μm that is sufficient to differentiate between subsurface histologic layers of the various regions of the GI tract. Ultrasound capsule endoscopy (USCE) uses a capsule equipped with μUS transducers that are capable of imaging below the GI wall surface, offering thereby a complementary sensing technique to optical imaging capsule endoscopy. In this work, a USCE device integrated with a ∼30 MHz ultrasonic transducer was developed to capture a full 360° image of the lumen. The performance of the device was initially evaluated using a wire phantom, indicating an axial resolution of 69.0 μm and lateral resolution of 262.5 μm. Later, in vivo imaging performance was characterised in the oesophagus and small intestine of anaesthetized pigs. The reconstructed images demonstrate clear layer differentiation of the lumen wall. The tissue thicknesses measured from the B-scan images show good agreement with ex vivo images from the literature. The high-resolution ultrasound images in the in vivo porcine model achieved with this device is an encouraging preliminary step in the translation of these devices toward future clinical use
A 5-year longitudinal study of schistosomiasis transmission in Shian village, the Anning River Valley, Sichuan Province, the Peoples' Republic of China
Background: Schistosoma japonicum is a major public health concern in the Peoples' Republic of China (PRC), with over one million people infected and another 50 million living in areas at risk of infection. Based on ecological, environmental, population genetic and molecular factors, schistosomiasis transmission in PRC can be categorised into four discrete ecosystems or transmission modes. It is predicted that the Three Gorges Dam (TGD) will impact upon the transmission of schistosomiasis in the PRC, with varying degree across the four transmission modes. We undertook longitudinal surveillance from 2002 to 2006 in sentinel villages both above and below the TGD across five provinces (Hunan, Jiangxi, Hubei, Anhui and Sichuan) to determine whether there was any impact of the TGD on schistosomiasis transmission during its construction. Here we present the results from a schistosomiasis-endemic village located above the dam in Sichuan Province. Results: Baseline results showed a human S. japonicum prevalence of 42.0% (95% CI: 36.6-47.5). At follow-up, results showed that the incidence of S. japonicum infection in the selected human cohort in Shian decreased by three quarters from 46% in 2003 to 11.3% in 2006. A significant (P < 0.01) downward trend was also evident in the yearly adjusted (for water contact) odds ratios. Over the four years of follow-up, the incidence of S. japonicum infection in bovines declined from 11.8% in the first year to zero in the final year of follow-up. Conclusions: The substantial decrease in human (75%) and bovine (100%) incidence observed in Shian village can probably be attributed to the annual human and bovine PZQ treatment of positives; as seen in drug (PZQ) intervention studies in other parts of PRC. If an increase in schistosome transmission had occurred as a result of the TGD, it would be of negligible size compared to the treatment induced decline seen here. It appears therefore that the construction of the TGD had virtually no impact on schistosomiasis transmission in Shian village over the period of study. Furthermore, contrary to previous reports from Sichuan downplaying the role of animals in human schistosome transmission, bovines may indeed play a role
On-chip black hole: Hawking radiation and curved spacetime in a superconducting quantum circuit with tunable couplers
Hawking radiation is one of quantum features of a black hole, which can be
understood as a quantum tunneling across the event horizon of the black hole,
but it is quite difficult to directly observe the Hawking radiation of an
astrophysical black hole. Remarkable experiments of analogue black holes on
various platforms have been performed. However, Hawking radiation and its
quantum nature such as entanglement have not been well tested due to the
experimental challenges in accurately constructing curved spacetime and
precisely measuring the thermal spectrum. Based on the recent architecture
breakthrough of tunable couplers for superconducting processor, we realize
experimentally an analogue black hole using our new developed chip with a chain
of 10 superconducting transmon qubits with interactions mediated by 9
transmon-type tunable couplers. By developing efficient techniques to engineer
the couplings between qubits via tuning couplers, we realize both the flat and
curved spacetime backgrounds. The quantum walks of quasi-particle in the curved
spacetime reflect the gravitational effect around the black hole, resulting in
the behavior of Hawking radiation. By virtue of the state tomography
measurement of all 7 qubits outside the analogue event horizon, we show that
Hawking radiation can be verified. In addition, an entangled pair is prepared
inside the horizon and the dynamics of entanglement in the curved spacetime is
directly measured. Our results would stimulate more interests to explore
information paradox, entropy and other related features of black holes using
programmable superconducting processor with tunable couplers.Comment: modified manuscripts, 7 pages, 4 figures (main text) + 12 pages
(supplementary information
A simulation study on the measurement of D0-D0bar mixing parameter y at BES-III
We established a method on measuring the \dzdzb mixing parameter for
BESIII experiment at the BEPCII collider. In this method, the doubly
tagged events, with one decays to
CP-eigenstates and the other decays semileptonically, are used to
reconstruct the signals. Since this analysis requires good separation,
a likelihood approach, which combines the , time of flight and the
electromagnetic shower detectors information, is used for particle
identification. We estimate the sensitivity of the measurement of to be
0.007 based on a fully simulated MC sample.Comment: 6 pages, 7 figure
Microarray-based analysis of microRNA expression in breast cancer stem cells
<p>Abstract</p> <p>Background</p> <p>This study aimed to determine the miRNA profile in breast cancer stem cells (BCSCs) and to explore the functions of characteristic BCSC miRNAs.</p> <p>Methods</p> <p>We isolated ESA<sup>+</sup>CD44<sup>+</sup>CD24<sup>-/low </sup>BCSCs from MCF-7 cells using fluorescence-activated cell sorting (FACS). A human breast cancer xenograft assay was performed to validate the stem cell properties of the isolated cells, and microarray analysis was performed to screen for BCSC-related miRNAs. These BCSC-related miRNAs were selected for bioinformatic analysis and target prediction using online software programs.</p> <p>Results</p> <p>The ESA<sup>+</sup>CD44<sup>+</sup>CD24<sup>-/low </sup>cells had up to 100- to 1000-fold greater tumor-initiating capability than the MCF-7 cells. Tumors initiated from the ESA<sup>+</sup>CD44<sup>+</sup>CD24<sup>-/low </sup>cells were included of luminal epithelial and myoepithelial cells, indicating stem cell properties. We also obtained miRNA profiles of ESA<sup>+</sup>CD44<sup>+</sup>CD24<sup>-/low </sup>BCSCs. Most of the possible targets of potential tumorigenesis-related miRNAs were oncogenes, anti-oncogenes or regulatory genes.</p> <p>Conclusions</p> <p>We identified a subset of miRNAs that were differentially expressed in BCSCs, providing a starting point to explore the functions of these miRNAs. Evaluating characteristic BCSC miRNAs represents a new method for studying breast cancer-initiating cells and developing therapeutic strategies aimed at eradicating the tumorigenic subpopulation of cells in breast cancer.</p
Nanoparticles of Metal-Organic Cages Overcoming Drug Resistance in Ovarian Cancer
A long-standing challenge in the treatment of ovarian cancer is drug resistance to standard platinum-based chemotherapy. Recently, increasing attention has been drawn to the use of self-assembled metal-organic complexes as novel therapeutics for cancer treatment. However, high hydrophobicity that is often associated with these structures lowers their solubility and hinders their clinical translation. In this article, we present a proof-of-concept study of using nanoprecipitation to formulate the hydrophobic metal-organic cages and facilitate their use in treating chemoresistant ovarian cancer. The Pt6L4 Cage 1 is an octahedral cage formed by self-assembly of six 1,10-phenanthroline-Pt(II) centers and four 2,4,6-tris(4-pyridyl)-1,3,5-triazine ligands (L). Cage 1 is able to trigger DNA damage and exhibits promising in vitro potency against a panel of human ovarian cancer cell lines. However, due to the large portion of aromatic components, this cage structure has very limited solubility in cell culture media (<20μM). Notably, upon nanoformulation by using fluorescein (2) and a pegylated anionic polymer (3), the concentration of Cage 1 can reach up to 0.4 mM. Production of the nanoparticles of metal-organic cages (nMOC) is driven by the formation of the 1:1 host-guest complex of 1 and 2 in aqueous solution, which then form nanoprecipitation in presence of poly glutamic acid-b-poly ethylene glycol (3). The resulted nMOC are about 100 nm in diameter, and they serve as a delivery platform that slowly releases the therapeutic content. The use of fluorescein facilitates monitoring cell entry of nMOC and drug release using flow cytometry. Finally, comparing to cisplatin, the nMOC exhibit comparable in vitro efficacy against a panel of human cancer cell lines, and notably, it shows a much lower resistance factor against chemoresistant ovarian cancer cell lines
Chemotherapy combined with radiotherapy can benefit more unresectable HCC patients with portal and/or hepatic vein invasion: a retrospective analysis of the SEER database
BackgroundThe purpose of this study is to evaluate the effects of chemotherapy and radiotherapy on the prognosis of unresectable HCC patients with portal and/or hepatic vein invasion.MethodsA retrospective analysis of unresectable HCC patients with portal and/or hepatic vein invasion registered in the Surveillance, Epidemiology, End Results (SEER) database was performed. The propensity score-matching (PSM) method was used to balance differences between groups. Overall survival (OS) and cancer-specific survival (CSS) were the interesting endpoints. OS was calculated from the date of diagnosis to the date of death caused by any cause or the last follow-up. CSS was defined as the interval between the date of diagnosis and date of death due only to HCC or last follow-up. OS and CSS were analyzed by using Kaplan-Meier analysis, Cox proportional hazards model, and Fine-Gray competing-risk model.ResultsA total of 2,614 patients were included. 50.2% patients received chemotherapy or radiotherapy and 7.5% patients received both chemotherapy and radiotherapy. Compared to the untreated group, chemotherapy or radiotherapy (COR) (HR = 0.538, 95% CI 0.495-0.585, p < 0.001) and chemotherapy and radiotherapy (CAR) (HR = 0.371, 95% CI 0.316-0.436, p < 0.001) showed better OS. In the COR group, Cox analysis results showed AFP, tumor size, N stage and M stage were independent risk factor of OS. Competing-risk analysis results showed AFP, tumor size and M stage were independent risk factor of CSS. In the CAR group, AFP and M stage were independent risk factors of OS. Competing-risk analysis results showed M stage were independent risk factor of CSS. Kaplan Meier analysis showed chemotherapy combined with radiotherapy significantly improves OS (10.0 vs. 5.0 months, p < 0.001) and CSS (10.0 vs. 6.0 months, p = 0.006) than monotherapy.ConclusionAFP positive and distant metastasis are the main risk factors affecting OS and CSS of unresectable HCC patients with portal and/or hepatic vein invasion. Chemotherapy combined with radiotherapy significantly improves OS and CSS of unresectable HCC patients with portal and/or hepatic vein invasion
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