20 research outputs found
Optical Monitoring of 3C 390.3 from 1995 to 2004 and Possible Periodicities in the Historical Light Curve
We report V, R, and I band CCD photometry of the radio galaxy 3C 390.3
obtained with the 1.56-m telescope of the Shanghai Astronomical Observatory
from March 1995 to August 2004. Combining these data with data from the
literature, we have constructed a historical light curve from 1894 to 2004 and
searched for periodicities using the CLEANest program. We find possible periods
of 8.30+-1.17, 5.37+-0.49, 3.51+-0.21, and 2.13+-0.08 years.Comment: Accepted by AJ, 34 pages, 11 figure
Global, regional, and national burden of disorders affecting the nervous system, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021
BackgroundDisorders affecting the nervous system are diverse and include neurodevelopmental disorders, late-life neurodegeneration, and newly emergent conditions, such as cognitive impairment following COVID-19. Previous publications from the Global Burden of Disease, Injuries, and Risk Factor Study estimated the burden of 15 neurological conditions in 2015 and 2016, but these analyses did not include neurodevelopmental disorders, as defined by the International Classification of Diseases (ICD)-11, or a subset of cases of congenital, neonatal, and infectious conditions that cause neurological damage. Here, we estimate nervous system health loss caused by 37 unique conditions and their associated risk factors globally, regionally, and nationally from 1990 to 2021.MethodsWe estimated mortality, prevalence, years lived with disability (YLDs), years of life lost (YLLs), and disability-adjusted life-years (DALYs), with corresponding 95% uncertainty intervals (UIs), by age and sex in 204 countries and territories, from 1990 to 2021. We included morbidity and deaths due to neurological conditions, for which health loss is directly due to damage to the CNS or peripheral nervous system. We also isolated neurological health loss from conditions for which nervous system morbidity is a consequence, but not the primary feature, including a subset of congenital conditions (ie, chromosomal anomalies and congenital birth defects), neonatal conditions (ie, jaundice, preterm birth, and sepsis), infectious diseases (ie, COVID-19, cystic echinococcosis, malaria, syphilis, and Zika virus disease), and diabetic neuropathy. By conducting a sequela-level analysis of the health outcomes for these conditions, only cases where nervous system damage occurred were included, and YLDs were recalculated to isolate the non-fatal burden directly attributable to nervous system health loss. A comorbidity correction was used to calculate total prevalence of all conditions that affect the nervous system combined.FindingsGlobally, the 37 conditions affecting the nervous system were collectively ranked as the leading group cause of DALYs in 2021 (443 million, 95% UI 378–521), affecting 3·40 billion (3·20–3·62) individuals (43·1%, 40·5–45·9 of the global population); global DALY counts attributed to these conditions increased by 18·2% (8·7–26·7) between 1990 and 2021. Age-standardised rates of deaths per 100 000 people attributed to these conditions decreased from 1990 to 2021 by 33·6% (27·6–38·8), and age-standardised rates of DALYs attributed to these conditions decreased by 27·0% (21·5–32·4). Age-standardised prevalence was almost stable, with a change of 1·5% (0·7–2·4). The ten conditions with the highest age-standardised DALYs in 2021 were stroke, neonatal encephalopathy, migraine, Alzheimer's disease and other dementias, diabetic neuropathy, meningitis, epilepsy, neurological complications due to preterm birth, autism spectrum disorder, and nervous system cancer.InterpretationAs the leading cause of overall disease burden in the world, with increasing global DALY counts, effective prevention, treatment, and rehabilitation strategies for disorders affecting the nervous system are needed
Multidepot Heterogeneous Vehicle Routing Problem for a Variety of Hazardous Materials with Risk Analysis
This study investigates a multidepot heterogeneous vehicle routing problem for a variety of hazardous materials with risk analysis, which is a practical problem in the actual industrial field. The objective of the problem is to design a series of routes that minimize the total cost composed of transportation cost, risk cost, and overtime work cost. Comprehensive consideration of factors such as transportation costs, multiple depots, heterogeneous vehicles, risks, and multiple accident scenarios is involved in our study. The problem is defined as a mixed integer programming model. A bidirectional tuning heuristic algorithm and particle swarm optimization algorithm are developed to solve the problem of different scales of instances. Computational results are competitive such that our algorithm can obtain effective results in small-scale instances and show great efficiency in large-scale instances with 70 customers, 30 vehicles, and 3 types of hazardous materials
Effect of Angelica sinensis Root Extract on Cancer Prevention in Different Stages of an AOM/DSS Mouse Model
Angelica sinensis root (ASR) extract was obtained to investigate its effects on colorectal carcinogenesis in different stages of an Azoxymethane/Dextran sodium sulphate (AOM/DSS) model. In this study, we showed that ASR extract administration in the initial stage of the AOM/DSS model had cancer preventive effects with decreasing tumor incidence and a high-grade of intraepithelial neoplasia incidence. With respect to DNA damage, the amounts of 8-oxoguanine and γ-H2AX were suppressed in colon tissue. The balance of apoptosis and proliferation was approaching the normal state. In contrast, ASR extract administration in the promotion stage of the AOM/DSS model accelerated the progression of carcinogenesis. The maximum tumor size reached 49.85 ± 25.04 mm3. High-grade pathological changes were significantly increased. Decreased DNA damage and P53 level reflected the disrupted reactive oxygen species (ROS) concentration in colorectal tissue, which led to an imbalance of proliferative and apoptotic relationships. These findings suggested that the cancer-preventive effect of ASR extract may be stage-dependent in the process of carcinogenesis
Effect of co-existent components in CO2 supercritical fluid extract of Angelica Sinensis Radix on metabolism of Z-ligustilide after oral administration in rats
Objective: To establish a basis for Angelica Sinensis Radix (ASR) as a dietary supplement for colorectal cancer chemoprevention, the effect of co-existent components in supercritical fluid extract (SFE) of ASR on the pharmacokinetics of Z-ligustilide after oral administration was investigated in vitro and in vivo.
Methods: Incubation in gastrointestinal contents and incubation in rat liver tissue homogenates post-mitochondrial supernatant (PMS) experiments were used to study changes in the levels of Z-ligustilide in vitro.
Results: Within 4 hours, the level of Z-ligustilide in SFE declined at a slower rate than in its pure form. Clearance of Z-ligustilide after administration in its pure form was significantly slower than that of SFE of ASR (CL, 0.96 ± 0.16 mL·min/kg versus 1.24 ± 0.21 mL·min/kg P < 0.05; AUC, 243.37 ± 16.84 versus 176.69 ± 12.59 mg·min/L).
Conclusion: These phenomena may be attributed to the interactions between the co-existent components in SFE of ASR and Z-ligustilide enhancing the stability of Z-ligustilide. These results suggest that the bioavailability of Z-ligustilide in SFE of ASR is improved. However, stabilization of plasma concentration was not sustained, so that the efficacy of active components could not be maintained. Thus, further processing of SFE of ASR is required
Ion Transport Behavior through Thermally Reduced Graphene Oxide Membrane for Precise Ion Separation
The cation transport behavior of thermally treated reduced graphene oxide membranes (GOMs) is reported. The GOMs were reduced by heat treatment at 25, 80, and 120 °C and then characterized by Fourier transform infrared spectroscopy, X-ray powder diffraction, and X-ray photoelectron spectroscopy to determine oxygen group content, C/O ratio, and layer spacing. The permeation rates of various cations with different sizes and charge numbers through these membranes were measured to understand the effect of the cations on transport behavior. The results indicated that the cation transport through the membranes depended on the layer spacing of the membrane and ion size and charge. Cations of the same valence permeating through the same GOM could be differentiated by their hydration radius, whereas the same type of cation passing through different GOMs could be determined by the spacing of the GOM layers. The cation valence strongly affected permeation behavior. The GOM that was prepared at 120 °C exhibited a narrow layer spacing and high separation factors for Mg/Ca, Mg/Sr, K/Ca, and K/Fe. The cations moving through the membrane could insert into the membrane lamellas, which neutralized the negative charge of the membrane, enlarged the layer spacing of the GOMs, and affected cation permeation
Quantitative Analysis of Resistance to Deformation of the DNA Origami Framework Supported by Struts
Nanostructures with controlled shapes
are of particular interest
due to their consistent physical and chemical properties and their
potential for assembly into complex superstructures. The use of supporting
struts has proven to be effective in the construction of precise DNA
polyhedra. However, the influence of struts on the structure of DNA
origami frameworks on the nanoscale remains unclear. In this study,
we developed a flexible square DNA origami (SDO) framework and enhanced
its structural stability by incorporating interarm supporting struts
(SDO-s). Comparing the framework with and without such struts, we
found that SDO-s demonstrated a significantly improved resistance
to deformation. We assessed the deformability of these two DNA origami
structures through the statistical analysis of interior angles of
polygons based on atomic force microscopy and transmission electron
microscopy data. Our results showed that SDO-s exhibited more centralized
interior angle distributions compared to SDO, reducing from 30–150°
to 60–120°. Furthermore, molecular dynamics simulations
indicated that supporting struts significantly decreased the thermodynamic
fluctuations of the SDO-s, as described by the root-mean-square fluctuation
parameter. Finally, we experimentally demonstrated that the 2D arrays
assembled from SDO-s exhibited significantly higher quality than those
assembled from SDO. These quantitative analyses provide an understanding
of how supporting struts can enhance the structural integrity of DNA
origami frameworks
Spacer-Programmed Two-Dimensional DNA Origami Assembly
Two-dimensional
(2D) DNA origami assembly represents a powerful
approach to the programmable design and construction of advanced 2D
materials. Within the context of hybridization-mediated 2D DNA origami
assembly, DNA spacers play a pivotal role as essential connectors
between sticky-end regions and DNA origami units. Here, we demonstrated
that programming the spacer length, which determines the binding radius
of DNA origami units, could effectively tune sticky-end hybridization
reactions to produce distinct 2D DNA origami arrays. Using DNA-PAINT
super-resolution imaging, we unveiled the significant impact of spacer
length on the hybridization efficiency of sticky ends for assembling
square DNA origami (SDO) units. We also found that the assembly efficiency
and pattern diversity of 2D DNA origami assemblies were critically
dependent on the spacer length. Remarkably, we realized a near-unity
yield of ∼98% for the assembly of SDO trimers and tetramers
via this spacer-programmed strategy. At last, we revealed that spacer
lengths and thermodynamic fluctuations of SDO are positively correlated,
using molecular dynamics simulations. Our study thus paves the way
for the precision assembly of DNA nanostructures toward higher complexity