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921.
Wang ZZ Li WJ Wang BQ Zhang BT Xing JZ Jing XG Dang BR Wei W Zhao WX 《Radiation and environmental biophysics》2011,50(3):383-387
Our work aims to understand the effects of shielding on the induction of biological damage by heavy charged particles and
to compare the shielding effects of different materials at the same LET from two aspects: the biological effectiveness including
or not including secondary particles emitted at large angles and the biological effectiveness at different angles with respect
to the beam direction. We designed and conducted biological experiments to determine the biological effectiveness of 200 MeV/u
carbon ions after traversing different shielding materials (Lucite and aluminium). Whole blood samples, which were either
attached to the shielding material (48 mm Lucite or 29 mm aluminium)or positioned at 300 cm away from it at different angles
with respect to the beam axis, were exposed to carbon ion beams. For comparison, whole blood samples were exposed directly
to 200 MeV/u carbon ions. Chromosomal aberrations in lymphocytes were scored. The results indicated that the biological effectiveness
per unit dose was not significantly changed by 48 mm Lucite or 29 mm aluminium, and no significant differences were observed
in lymphocytes attached to the target and in lymphocytes positioned at a distance of 300 cm away from the target, at 0o angle
of the beam axis. However, when plotted as a function of the number of ions hitting the shielding target, the curves are separated
and the shield increases the effectiveness per unit ion. The frequency of chromosomal aberrations at tilted angles behind
29 mm Al and 48 mm Lucite was almost the same. These lesions were considered to be caused by secondary particles due to the
passage of particles through the shielding materials. 相似文献
922.
Bunsyo Shiotani Hai Dang Nguyen Pelle Håkansson Alexandre Maréchal Alice Tse Hidetoshi Tahara Lee Zou 《Cell reports》2013,3(5):1651-1662
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923.
Donald Joshua Cameron Faydim Rassamdana Peony Tam Kathleen Dang Carolina Yanez Saman Ghaemmaghami Mahsa Iranpour Dehkordi 《Journal of visualized experiments : JoVE》2013,(80)
Zebrafish are a proven model for vision research, however many of the earlier methods generally focused on larval fish or demonstrated a simple response. More recently adult visual behavior in zebrafish has become of interest, but methods to measure specific responses are new coming. To address this gap, we set out to develop a methodology to repeatedly and accurately utilize the optokinetic response (OKR) to measure visual acuity in adult zebrafish. Here we show that the adult zebrafish''s visual acuity can be measured, including both binocular and monocular acuities. Because the fish is not harmed during the procedure, the visual acuity can be measured and compared over short or long periods of time. The visual acuity measurements described here can also be done quickly allowing for high throughput and for additional visual procedures if desired. This type of analysis is conducive to drug intervention studies or investigations of disease progression. 相似文献
924.
Felipe J. Coln-Gonzlez Leonardo Soares Bastos Barbara Hofmann Alison Hopkin Quillon Harpham Tom Crocker Rosanna Amato Iacopo Ferrario Francesca Moschini Samuel James Sajni Malde Eleanor Ainscoe Vu Sinh Nam Dang Quang Tan Nguyen Duc Khoa Mark Harrison Gina Tsarouchi Darren Lumbroso Oliver J. Brady Rachel Lowe 《PLoS medicine》2021,18(3)
BackgroundWith enough advanced notice, dengue outbreaks can be mitigated. As a climate-sensitive disease, environmental conditions and past patterns of dengue can be used to make predictions about future outbreak risk. These predictions improve public health planning and decision-making to ultimately reduce the burden of disease. Past approaches to dengue forecasting have used seasonal climate forecasts, but the predictive ability of a system using different lead times in a year-round prediction system has been seldom explored. Moreover, the transition from theoretical to operational systems integrated with disease control activities is rare.Methods and findingsWe introduce an operational seasonal dengue forecasting system for Vietnam where Earth observations, seasonal climate forecasts, and lagged dengue cases are used to drive a superensemble of probabilistic dengue models to predict dengue risk up to 6 months ahead. Bayesian spatiotemporal models were fit to 19 years (2002–2020) of dengue data at the province level across Vietnam. A superensemble of these models then makes probabilistic predictions of dengue incidence at various future time points aligned with key Vietnamese decision and planning deadlines. We demonstrate that the superensemble generates more accurate predictions of dengue incidence than the individual models it incorporates across a suite of time horizons and transmission settings. Using historical data, the superensemble made slightly more accurate predictions (continuous rank probability score [CRPS] = 66.8, 95% CI 60.6–148.0) than a baseline model which forecasts the same incidence rate every month (CRPS = 79.4, 95% CI 78.5–80.5) at lead times of 1 to 3 months, albeit with larger uncertainty. The outbreak detection capability of the superensemble was considerably larger (69%) than that of the baseline model (54.5%). Predictions were most accurate in southern Vietnam, an area that experiences semi-regular seasonal dengue transmission. The system also demonstrated added value across multiple areas compared to previous practice of not using a forecast. We use the system to make a prospective prediction for dengue incidence in Vietnam for the period May to October 2020. Prospective predictions made with the superensemble were slightly more accurate (CRPS = 110, 95% CI 102–575) than those made with the baseline model (CRPS = 125, 95% CI 120–168) but had larger uncertainty. Finally, we propose a framework for the evaluation of probabilistic predictions. Despite the demonstrated value of our forecasting system, the approach is limited by the consistency of the dengue case data, as well as the lack of publicly available, continuous, and long-term data sets on mosquito control efforts and serotype-specific case data.ConclusionsThis study shows that by combining detailed Earth observation data, seasonal climate forecasts, and state-of-the-art models, dengue outbreaks can be predicted across a broad range of settings, with enough lead time to meaningfully inform dengue control. While our system omits some important variables not currently available at a subnational scale, the majority of past outbreaks could be predicted up to 3 months ahead. Over the next 2 years, the system will be prospectively evaluated and, if successful, potentially extended to other areas and other climate-sensitive disease systems. 相似文献
925.
926.
Toshihiro Okamoto Satoshi Iwata Hiroto Yamazaki Ryo Hatano Eriko Komiya Nam H. Dang Kei Ohnuma Chikao Morimoto 《PloS one》2014,9(1)
CD26/dipeptidyl peptidase IV is a cell surface glycoprotein which consists of multiple functional domains beside its ectopeptidase site. A growing body of evidence indicates that elevated expression of CD26 correlates with disease aggressiveness and invasive potential of selected malignancies. To further explore the molecular mechanisms involved in this clinical behavior, our current work focused on the interaction between CD26 and CD9, which were recently identified as novel markers for cancer stem cells in malignant mesothelioma. We found that CD26 and CD9 co-modulated and co-precipitated with each other in the malignant mesothelioma cell lines ACC-MESO1 and MSTO-211H. SiRNA study revealed that depletion of CD26 led to increased CD9 expression, while depletion of CD9 resulted in increased CD26 expression. Consistent with these findings was the fact that gene transfer of CD26 into CD26-negative MSTO-211H cells reduced CD9 expression. Cell invasion assay showed that overexpression of CD26 or gene depletion of CD9 led to enhanced invasiveness, while CD26 gene depletion resulted in reduced invasive potential. Furthermore, our work suggested that this enhanced invasiveness may be partly mediated by α5β1 integrin, since co-precipitation studies demonstrated an association between CD26 and α5β1 integrin. Finally, gene depletion of CD9 resulted in elevated protein levels and tyrosine phosphorylation of FAK and Cas-L, which are downstream of β1 integrin, while depletion of CD26 led to a reduction in the levels of these molecules. Collectively, our findings suggest that CD26 potentiates tumor cell invasion through its interaction with α5β1 integrin, and CD9 negatively regulates tumor cell invasion by reducing the level of CD26-α5β1 integrin complex through an inverse correlation between CD9 and CD26 expression. Our results also suggest that CD26 and CD9 serve as potential biomarkers as well as promising molecular targets for novel therapeutic approaches in malignant mesothelioma and other malignancies. 相似文献
927.
Agustin Anastasia Katrin Deinhardt Shiyang Wang Laura Martin Donna Nichol Krithi Irmady Jasmine Trinh Luis Parada Shahin Rafii Barbara L. Hempstead Pouneh Kermani 《PloS one》2014,9(1)
Pericyte and vascular smooth muscle cell (SMC) recruitment to the developing vasculature is an important step in blood vessel maturation. Brain-derived neurotrophic factor (BDNF), expressed by endothelial cells, activates the receptor tyrosine kinase TrkB to stabilize the cardiac microvasculature in the perinatal period. However, the effects of the BDNF/TrkB signaling on pericytes/SMCs and the mechanisms downstream of TrkB that promote vessel maturation are unknown. To confirm the involvement of TrkB in vessel maturation, we evaluated TrkB deficient (trkb
−/−) embryos and observed severe cardiac vascular abnormalities leading to lethality in late gestation to early prenatal life. Ultrastructural analysis demonstrates that trkb−/− embryos exhibit defects in endothelial cell integrity and perivascular edema. As TrkB is selectively expressed by pericytes and SMCs in the developing cardiac vasculature, we generated mice deficient in TrkB in these cells. Mice with TrkB deficiency in perivascular cells exhibit reduced pericyte/SMC coverage of the cardiac microvasculature, abnormal endothelial cell ultrastructure, and increased vascular permeability. To dissect biological actions and the signaling pathways downstream of TrkB in pericytes/SMCs, human umbilical SMCs were treated with BDNF. This induced membranous protrusions and cell migration, events dependent on myosin light chain phosphorylation. Moreover, inhibition of Rho GTPase and the Rho-associated protein kinase (ROCK) prevented membrane protrusion and myosin light chain phosphorylation in response to BDNF. These results suggest an important role for BDNF in regulating migration of TrkB-expressing pericytes/SMCs to promote cardiac blood vessel ensheathment and functional integrity during development. 相似文献
928.
Yongsheng Wang Shulan Cheng Huajun Fang Guirui Yu Minjie Xu Xusheng Dang Linsen Li Lei Wang 《PloS one》2014,9(4)
To date, few studies are conducted to quantify the effects of reduced ammonium (NH4
+) and oxidized nitrate (NO3
−) on soil CH4 uptake and N2O emission in the subtropical forests. In this study, NH4Cl and NaNO3 fertilizers were applied at three rates: 0, 40 and 120 kg N ha−1 yr−1. Soil CH4 and N2O fluxes were determined twice a week using the static chamber technique and gas chromatography. Soil temperature and moisture were simultaneously measured. Soil dissolved N concentration in 0–20 cm depth was measured weekly to examine the regulation to soil CH4 and N2O fluxes. Our results showed that one year of N addition did not affect soil temperature, soil moisture, soil total dissolved N (TDN) and NH4
+-N concentrations, but high levels of applied NH4Cl and NaNO3 fertilizers significantly increased soil NO3
−-N concentration by 124% and 157%, respectively. Nitrogen addition tended to inhibit soil CH4 uptake, but significantly promoted soil N2O emission by 403% to 762%. Furthermore, NH4
+-N fertilizer application had a stronger inhibition to soil CH4 uptake and a stronger promotion to soil N2O emission than NO3
−-N application. Also, both soil CH4 and N2O fluxes were driven by soil temperature and moisture, but soil inorganic N availability was a key integrator of soil CH4 uptake and N2O emission. These results suggest that the subtropical plantation soil sensitively responses to atmospheric N deposition, and inorganic N rather than organic N is the regulator to soil CH4 uptake and N2O emission. 相似文献
929.
Jingshan Huang Jiangbo Dang Glen M. Borchert Karen Eilbeck He Zhang Min Xiong Weijian Jiang Hao Wu Judith A. Blake Darren A. Natale Ming Tan 《PloS one》2014,9(7)
As a special class of short non-coding RNAs, microRNAs (a.k.a. miRNAs or miRs) have been reported to perform important roles in various biological processes by regulating respective target genes. However, significant barriers exist during biologists'' conventional miR knowledge discovery. Emerging semantic technologies, which are based upon domain ontologies, can render critical assistance to this problem. Our previous research has investigated the construction of a miR ontology, named Ontology for MIcroRNA Target Prediction (OMIT), the very first of its kind that formally encodes miR domain knowledge. Although it is unavoidable to have a manual component contributed by domain experts when building ontologies, many challenges have been identified for a completely manual development process. The most significant issue is that a manual development process is very labor-intensive and thus extremely expensive. Therefore, we propose in this paper an innovative ontology development methodology. Our contributions can be summarized as: (i) We have continued the development and critical improvement of OMIT, solidly based on our previous research outcomes. (ii) We have explored effective and efficient algorithms with which the ontology development can be seamlessly combined with machine intelligence and be accomplished in a semi-automated manner, thus significantly reducing large amounts of human efforts. A set of experiments have been conducted to thoroughly evaluate our proposed methodology. 相似文献
930.
Shaonong Dang Hong Yan Lingxia Zeng Quanli Wang Qiang Li Shengbin Xiao Xiaojing Fan 《PloS one》2014,9(11)