503 research outputs found

    Genome Writing:Current Progress and Related Applications

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    The ultimate goal of synthetic biology is to build customized cells or organisms to meet specific industrial or medical needs. The most important part of the customized cell is a synthetic genome. Advanced genomic writing technologies are required to build such an artificial genome. Recently, the partially-completed synthetic yeast genome project represents a milestone in this field. In this mini review, we briefly introduce the techniques for de novo genome synthesis and genome editing. Furthermore, we summarize recent research progresses and highlight several applications in the synthetic genome field. Finally, we discuss current challenges and future prospects. Keywords: Synthetic biology, Genome writing, Genome editing, Bioethics, Biosafet

    {3,3′-Bis[(anthracen-9-yl)meth­yl]-1,1′-[(ethane-1,2-diyldi­oxy)bis­(ethane-1,2-di­yl)]bis­(imidazol-2-yl­idene)}mercury(II) bis­(hexa­fluoridophosphate) acetonitrile disolvate

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    In the title compound, [Hg(C42H38N4O2)](PF6)2·2CH3CN, the HgII cation lies on a twofold axis which is also the inter­nal symmetry element of the complete cationic complex. The HgII cation is coordinated by two symmetry-related C(carbene) atoms [Hg—C = 2.058 (9) Å] in a nearly linear geometry, with a C—Hg—C angle of 175.8 (5)°. There are weak inter­molecular C—H⋯F inter­actions in the crystal packing between an F atom of a hexa­fluoridophosphate anion and a –CH2– group of the bis-N-heterocyclic carbene ligand

    AdaFuse: Adaptive Medical Image Fusion Based on Spatial-Frequential Cross Attention

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    Multi-modal medical image fusion is essential for the precise clinical diagnosis and surgical navigation since it can merge the complementary information in multi-modalities into a single image. The quality of the fused image depends on the extracted single modality features as well as the fusion rules for multi-modal information. Existing deep learning-based fusion methods can fully exploit the semantic features of each modality, they cannot distinguish the effective low and high frequency information of each modality and fuse them adaptively. To address this issue, we propose AdaFuse, in which multimodal image information is fused adaptively through frequency-guided attention mechanism based on Fourier transform. Specifically, we propose the cross-attention fusion (CAF) block, which adaptively fuses features of two modalities in the spatial and frequency domains by exchanging key and query values, and then calculates the cross-attention scores between the spatial and frequency features to further guide the spatial-frequential information fusion. The CAF block enhances the high-frequency features of the different modalities so that the details in the fused images can be retained. Moreover, we design a novel loss function composed of structure loss and content loss to preserve both low and high frequency information. Extensive comparison experiments on several datasets demonstrate that the proposed method outperforms state-of-the-art methods in terms of both visual quality and quantitative metrics. The ablation experiments also validate the effectiveness of the proposed loss and fusion strategy

    Trade-offs among cost, integration, and segregation in the human connectome

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    AbstractThe human brain structural network is thought to be shaped by the optimal trade-off between cost and efficiency. However, most studies on this problem have focused on only the trade-off between cost and global efficiency (i.e., integration) and have overlooked the efficiency of segregated processing (i.e., segregation), which is essential for specialized information processing. Direct evidence on how trade-offs among cost, integration, and segregation shape the human brain network remains lacking. Here, adopting local efficiency and modularity as segregation factors, we used a multiobjective evolutionary algorithm to investigate this problem. We defined three trade-off models, which represented trade-offs between cost and integration (Dual-factor model), and trade-offs among cost, integration, and segregation (local efficiency or modularity; Tri-factor model), respectively. Among these, synthetic networks with optimal trade-off among cost, integration, and modularity (Tri-factor model [Q]) showed the best performance. They had a high recovery rate of structural connections and optimal performance in most network features, especially in segregated processing capacity and network robustness. Morphospace of this trade-off model could further capture the variation of individual behavioral/demographic characteristics in a domain-specific manner. Overall, our results highlight the importance of modularity in the formation of the human brain structural network and provide new insights into the original cost-efficiency trade-off hypothesis

    Lasting DNA Damage and Aberrant DNA Repair Gene Expression Profile Are Associated with Post-Chronic Cadmium Exposure in Human Bronchial Epithelial Cells

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    Cadmium (Cd) is a widespread environmental pollutant and carcinogen. Although the exact mechanisms of Cd-induced carcinogenesis remain unclear, previous acute/chronic Cd exposure studies have shown that Cd exerts its cytotoxic and carcinogenic effects through multiple mechanisms, including interference with the DNA repair system. However, the effects of post-chronic Cd exposure remain unknown. Here, we establish a unique post-chronic Cd-exposed human lung cell model (the CR0 cells) and investigate the effects of post-chronic Cd exposure on the DNA repair system. We found that the CR0 cells retained Cd-resistant property even though it was grown in Cd-free culture medium for over a year. The CR0 cells had lasting DNA damage due to reduced DNA repair capacity and an aberrant DNA repair gene expression profile. A total of 12 DNA repair genes associated with post-chronic Cd exposure were identified, and they could be potential biomarkers for identifying post-chronic Cd exposure. Clinical database analysis suggests that some of the DNA repair genes play a role in lung cancer patients with different smoking histories. Generally, CR0 cells were more sensitive to chemotherapeutic (cisplatin, gemcitabine, and vinorelbine tartrate) and DNA damaging (H2O2) agents, which may represent a double-edged sword for cancer prevention and treatment. Overall, we demonstrated for the first time that the effects of post-chronic Cd exposure on human lung cells are long-lasting and different from that of acute and chronic exposures. Findings from our study unveiled a new perspective on Cd-induced carcinogenesis-the post-chronic exposure of Cd. This study encourages the field of post-exposure research which is crucial but has long been ignored

    A general model for collaboration networks

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    In this paper, we propose a general model for collaboration networks. Depending on a single free parameter "{\bf preferential exponent}", this model interpolates between networks with a scale-free and an exponential degree distribution. The degree distribution in the present networks can be roughly classified into four patterns, all of which are observed in empirical data. And this model exhibits small-world effect, which means the corresponding networks are of very short average distance and highly large clustering coefficient. More interesting, we find a peak distribution of act-size from empirical data which has not been emphasized before of some collaboration networks. Our model can produce the peak act-size distribution naturally that agrees with the empirical data well.Comment: 10 pages, 10 figure

    Bufei Huoxue Capsule Attenuates PM2.5-Induced Pulmonary Inflammation in Mice

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    Atmospheric fine particulate matter 2.5 (PM 2.5) may carry many toxic substances on its surface and this may pose a public health threat. Epidemiological research indicates that cumulative ambient PM2.5 is correlated to morbidity and mortality due to pulmonary and cardiovascular diseases and cancer. Mitigating the toxic effects of PM2.5 is therefore highly desired. Bufei Huoxue (BFHX) capsules have been used in China to treat pulmonary heart disease (cor pulmonale). Thus, we assessed the effects of BFHX capsules on PM2.5-induced pulmonary inflammation and the underlying mechanisms of action. Using Polysearch and Cytoscape 3.2.1 software, pharmacological targets of BFHX capsules in atmospheric PM2.5-related respiratory disorders were predicted and found to be related to biological pathways of inflammation and immune function. In a mouse model of PM2.5-induced inflammation established with intranasal instillation of PM2.5 suspension, BFHX significantly reduced pathological response and inflammatory mediators including IL-4, IL-6, IL-10, IL-8, TNF-α, and IL-1β. BFHX also reduced keratinocyte growth factor (KGF), secretory immunoglobulin A (sIgA), and collagen fibers deposition in lung and improved lung function. Thus, BFHX reduced pathological responses induced by PM2.5, possibly via regulation of inflammatory mediators in mouse lungs

    Expression of the Androgen Receptor and its Correlation with Molecular Subtypes in 980 Chinese Breast Cancer Patients

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    Background Recent studies have shown that androgen displays an inhibitory effect on breast cancer cell lines that express androgen receptor (AR) but not estrogen receptor (ER) and progesterone receptor (PR). We have previously reported that approximately 1/3 of ER negative high grade invasive ductal carcinomas express AR. Thus, AR can serve as a potential therapeutic target for this group of patients. Aim Here we investigated AR expression patterns in 980 consecutive breast carcinomas. Results We found that (1) AR was expressed more frequently (77%) than ER (61%) and PR (60%) in breast carcinomas; (2) AR expression was associated with ER and PR expression ( P < 0.0001), small tumor size ( P = 0.0324) and lower Ki-67 expression ( P = 0.0013); (3) AR expression was found in 65% of ER negative tumors; (4) AR expression was associated with PR and Ki-67 in ER negative tumors, but not in ER positive tumors; (5) AR expression was higher in ER positive subtypes (Luminal A, Luminal B and Luminal HER2 subtypes, 80%-86%) and lower in ER negative subtypes [HER2, triple negative (TN), and TN EFGR positive subtypes; 52%-66%], with over 50% of TN tumors expressing AR. Conclusion More breast carcinomas express AR than ER and PR, including significant numbers of ER negative and TN tumors, for which AR could serve as a potential therapeutic target

    Personalized antiplatelet therapy guided by clopidogrel pharmacogenomics in acute ischemic stroke and transient ischemic attack: A prospective, randomized controlled trial

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    Background: Clopidogrel is frequently used in patients with ischemic stroke or transient ischemic attack (TIA), but its efficacy is hampered by inter-individual variability, due to genetic differences associated with clopidogrel metabolism. We conducted this randomized controlled trial to validate whether the personalized antiplatelet therapy based on clopidogrel pharmacogenomics and clinical characteristics leads to better clinical outcomes compared with standard treatment.Methods: Patients were randomly divided into the standard group or pharmacogenetic group, in which the pharmacogenetic group required the detection of the genotyping of CYP2C19*2, CYP2C19*3, and CYP2C19*17. Patients were followed up for 90 days for the primary efficacy endpoint of new stroke events, secondary efficacy endpoint of individual or composite outcomes of the new clinical vascular events, and the incidence of disability. The primary safety outcome was major bleeding.Results: A total of 650 patients underwent randomization, among which 325 were in the pharmacogenomics group while 325 were in the standard group. Our study found after a 90-day follow-up, the risk of stroke and composite vascular events in the pharmacogenomics group was lower than that in the standard group. The incidence of disability significantly decreased in the pharmacogenomics group. In addition, no statistically significant differences were observed in bleeding events between the two groups.Conclusion: The present study demonstrates that personalized antiplatelet therapy guided by clopidogrel pharmacogenomics and clinical characteristics can significantly improve the net clinical benefit of ischemic stroke or TIA patients during the 90-day treatment period without increasing bleeding risk
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