1,179 research outputs found
Study on the visible-light-induced photokilling effect of nitrogen-doped TiO2 nanoparticles on cancer cells
Nitrogen-doped TiO2 (N-TiO2) nanoparticles were prepared by calcining the anatase TiO2 nanoparticles under ammonia atmosphere. The N-TiO2 showed higher absorbance in the visible region than the pure TiO2. The cytotoxicity and visible-light-induced phototoxicity of the pure- and N-TiO2 were examined for three types of cancer cell lines. No significant cytotoxicity was detected. However, the visible-light-induced photokilling effects on cells were observed. The survival fraction of the cells decreased with the increased incubation concentration of the nanoparticles. The cancer cells incubated with N-TiO2 were killed more effectively than that with the pure TiO2. The reactive oxygen species was found to play an important role on the photokilling effect for cells. Furthermore, the intracellular distributions of N-TiO2 nanoparticles were examined by laser scanning confocal microscopy. The co-localization of N-TiO2 nanoparticles with nuclei or Golgi complexes was observed. The aberrant nuclear morphologies such as micronuclei were detected after the N-TiO2-treated cells were irradiated by the visible light
GEOGLE: context mining tool for the correlation between gene expression and the phenotypic distinction
<p>Abstract</p> <p>Background</p> <p>In the post-genomic era, the development of high-throughput gene expression detection technology provides huge amounts of experimental data, which challenges the traditional pipelines for data processing and analyzing in scientific researches.</p> <p>Results</p> <p>In our work, we integrated gene expression information from Gene Expression Omnibus (GEO), biomedical ontology from Medical Subject Headings (MeSH) and signaling pathway knowledge from sigPathway entries to develop a context mining tool for gene expression analysis – GEOGLE. GEOGLE offers a rapid and convenient way for searching relevant experimental datasets, pathways and biological terms according to multiple types of queries: including biomedical vocabularies, GDS IDs, gene IDs, pathway names and signature list. Moreover, GEOGLE summarizes the signature genes from a subset of GDSes and estimates the correlation between gene expression and the phenotypic distinction with an integrated p value.</p> <p>Conclusion</p> <p>This approach performing global searching of expression data may expand the traditional way of collecting heterogeneous gene expression experiment data. GEOGLE is a novel tool that provides researchers a quantitative way to understand the correlation between gene expression and phenotypic distinction through meta-analysis of gene expression datasets from different experiments, as well as the biological meaning behind. The web site and user guide of GEOGLE are available at: <url>http://omics.biosino.org:14000/kweb/workflow.jsp?id=00020</url></p
Effects of a Long-Acting Formulation of Octreotide on Patients with Portal Hypertension
Objective. This study aimed to determine whether the treatment of a long-acting formulation of octreotide (OCT-LAR) exerted a similar effect on improving the prognosis of patients with portal hypertension compared with placement of transjugular intrahepatic portosystemic shunts (TIPSs). Methods. A total of 24 patients with portal hypertension who underwent TIPS placement or OCT-LAR treatment from January 2010 to January 2015 were reviewed. Hemodynamic studies, biological values, live functions, and treatment complications before and during the treatment were evaluated. Results. Baseline clinical characteristics were similar between two groups. Hepatic venous pressure gradient (HVPG) was improved in OCT-LAR groups (15.9 ± 2.4 to 12.8 ± 1.6 mmHg). Both groups showed a slight decrease in endothelin-1 (ET-1) and urotensin II and a slight increase in oxide metabolite (NOx) concentrations with no significant difference. Aspartate aminotransferase and alanine aminotransferase increased one week after TIPS placement when they improved in the OCT-LAR treatment group. The complications of OCT-LAR treatment were minor and transient. However, one patient who received TIPS placement presented procedure-related complications and required rehospitalization, and 2 patients had developed hepatic encephalopathy during the follow-up period. Conclusion. Prolonged administration of OCT-LAR exerted a virtually similar effect on improving hemodynamic parameters and liver function in patients with portal hypertension compared with placement of TIPS, with no apparent serious adverse effects
Ionised carbon and galaxy activity
We investigate the possibility that the decrease in the relative luminosity
of the 158 micron [CII] line with the far-infrared luminosity in extragalactic
sources stems from a stronger contribution from the heated dust emission in the
more distant sources. Due to the flux limited nature of these surveys, the
luminosity of the detected objects increases with distance. However, the [CII]
luminosity does not climb as steeply as that of the far-infrared, giving the
decline in the L_[CII]/L_FIR ratio with L_FIR. Investigating this further, we
find that the [CII] luminosity exhibits similar drops as measured against the
carbon monoxide and radio continuum luminosities. The former may indicate that
at higher luminosities a larger fraction of the carbon is locked up in the form
of molecules and/or that the CO line radiation also contributes to the cooling,
done mainly by the [CII] line at low luminosities. The latter hints at
increased activity in these galaxies at greater distances, so we suggest that,
in addition to an underlying heating of the dust by a stellar population, there
is also heating of the embedded dusty torus by the ultra-violet emission from
the active nucleus, resulting in an excess in the far-infrared emission from
the more luminous objects.Comment: 9 pages, accepted by A&
Quantum phase transition in magnetic nanographenes on a lead superconductor
Quantum spins, referred to the spin operator preserved by full SU(2) symmetry
in the absence of the magnetic anistropy, have been proposed to host exotic
interactions with superconductivity4. However, spin orbit coupling and crystal
field splitting normally cause a significant magnetic anisotropy for d/f-shell
spins on surfaces6,9, breaking SU(2) symmetry and fabricating the spins with
Ising properties10. Recently, magnetic nanographenes have been proven to host
intrinsic quantum magnetism due to their negligible spin orbital coupling and
crystal field splitting. Here, we fabricate three atomically precise
nanographenes with the same magnetic ground state of spin S=1/2 on Pb(111)
through engineering sublattice imbalance in graphene honeycomb lattice.
Scanning tunneling spectroscopy reveals the coexistence of magnetic bound
states and Kondo screening in such hybridized system. Through engineering the
magnetic exchange strength between the unpaired spin in nanographenes and
cooper pairs, quantum phase transition from the singlet to the doublet state
has been observed, in consistent with quantum models of spins on
superconductors. Our work demonstrates delocalized graphene magnetism host
highly tunable magnetic bound states with cooper pairs, which can be further
developed to study the Majorana bound states and other rich quantum physics of
low-dimensional quantum spins on superconductors.Comment: 13 pages, 4figure
Indoor CO2 monitoring in a surgical intensive care unit under visitation restrictions during the COVID-19 pandemic
BackgroundIndoor CO2 concentration is an important metric of indoor air quality (IAQ). The dynamic temporal pattern of CO2 levels in intensive care units (ICUs), where healthcare providers experience high cognitive load and occupant numbers are frequently changing, has not been comprehensively characterized.ObjectiveWe attempted to describe the dynamic change in CO2 levels in the ICU using an Internet of Things-based (IoT-based) monitoring system. Specifically, given that the COVID-19 pandemic makes hospital visitation restrictions necessary worldwide, this study aimed to appraise the impact of visitation restrictions on CO2 levels in the ICU.MethodsSince February 2020, an IoT-based intelligent indoor environment monitoring system has been implemented in a 24-bed university hospital ICU, which is symmetrically divided into areas A and B. One sensor was placed at the workstation of each area for continuous monitoring. The data of CO2 and other pollutants (e.g., PM2.5) measured under standard and restricted visitation policies during the COVID-19 pandemic were retrieved for analysis. Additionally, the CO2 levels were compared between workdays and non-working days and between areas A and B.ResultsThe median CO2 level (interquartile range [IQR]) was 616 (524–682) ppm, and only 979 (0.34%) data points obtained in area A during standard visitation were ≥ 1,000 ppm. The CO2 concentrations were significantly lower during restricted visitation (median [IQR]: 576 [556–596] ppm) than during standard visitation (628 [602–663] ppm; p < 0.001). The PM2.5 concentrations were significantly lower during restricted visitation (median [IQR]: 1 [0–1] μg/m3) than during standard visitation (2 [1–3] μg/m3; p < 0.001). The daily CO2 and PM2.5 levels were relatively low at night and elevated as the occupant number increased during clinical handover and visitation. The CO2 concentrations were significantly higher in area A (median [IQR]: 681 [653–712] ppm) than in area B (524 [504–547] ppm; p < 0.001). The CO2 concentrations were significantly lower on non-working days (median [IQR]: 606 [587–671] ppm) than on workdays (583 [573–600] ppm; p < 0.001).ConclusionOur study suggests that visitation restrictions during the COVID-19 pandemic may affect CO2 levels in the ICU. Implantation of the IoT-based IAQ sensing network system may facilitate the monitoring of indoor CO2 levels
Epidemiologic Characterization of Human Papillomavirus Infection in Rural Chaozhou, Eastern Guangdong Province of China
BACKGROUND: Human papilloma virus (HPV) infection was the main cause of cervical cancer. There were only a few reports and detailed data about epidemiological research of HPV infection in rural population of China. MATERIALS AND METHODS: The cervical cells of rural Chaozhou women were collected, and multiplex real time PCR was firstly performed to detect high-risk HPV (HR-HPV) infection, which could detect 13 types of HR-HPV (types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, and 68). Then, HPV-positive samples were typed by HPV GenoArray test. RESULTS: HR-HPV DNA was detected by multiplex real time-PCR in 3830 of 48559 cases (7.89%). There was a peak incidence in age of 55-60 years group, and a lower incidence in who lived in plain group compared with suburban, mountain and seashore group. 3380 cases of HPV positive sample were genotyped, 11.01% (372/3380) cases could not be classified, among the typed 3008 cases, 101 cases were identified without HR-HPV type infection, 2907 cases were infected with one HR-HPV type at least, the 6 most common HR-HPV types in descending order of infection, were type 52 (33.4%, 16 (20.95%), 58 (15.93%), 33 (9.94%), 68 (9.22%) and 18 (8.36%). The combined prevalence of HPV types 16 and 18 accounted for 28.52% of total infection. However, type 52 plus 58 presented 48.23% of total infection. 2209/2907 cases were infected with a single HPV type and 698/2907 cases were infected with multiple types, and multiple infection constituent ratio increased with age, with a peak incidence in age 55-60 years group. CONCLUSIONS: Our findings showed low prevalence of HPV vaccine types (16 and 18) and relatively high prevalence of HPV-52 and -58, support the hypothesis that the second-generation HPV vaccines including HPV-52 and -58 may offer higher protection for women in rural Guangdong Province
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