65 research outputs found
Chronic vagus nerve stimulation in patients with heart failure: challenge or failed translation?
Autonomic imbalance between the sympathetic and parasympathetic nervous systems contributes to the progression of chronic heart failure (HF). Preclinical studies have demonstrated that various neuromodulation strategies may exert beneficial cardioprotective effects in preclinical models of HF. Based on these encouraging experimental data, vagus nerve stimulation (VNS) has been assessed in patients with HF with a reduced ejection fraction. Nevertheless, the main trials conducted thus far have yielded conflicting findings, questioning the clinical efficacy of VNS in this context. This review will therefore focus on the role of the autonomic nervous system in HF pathophysiology and VNS therapy, highlighting the potential reasons behind the discrepancy between preclinical and clinical studies
Control of Kaposi's Sarcoma-Associated Herpesvirus Reactivation Induced by Multiple Signals
The ability to control cellular functions can bring about many developments in basic biological research and its applications. The presence of multiple signals, internal as well as externally imposed, introduces several challenges for controlling cellular functions. Additionally the lack of clear understanding of the cellular signaling network limits our ability to infer the responses to a number of signals. This work investigates the control of Kaposi's sarcoma-associated herpesvirus reactivation upon treatment with a combination of multiple signals. We utilize mathematical model-based as well as experiment-based approaches to achieve the desired goals of maximizing virus reactivation. The results show that appropriately selected control signals can induce virus lytic gene expression about ten folds higher than a single drug; these results were validated by comparing the results of the two approaches, and experimentally using multiple assays. Additionally, we have quantitatively analyzed potential interactions between the used combinations of drugs. Some of these interactions were consistent with existing literature, and new interactions emerged and warrant further studies. The work presents a general method that can be used to quantitatively and systematically study multi-signal induced responses. It enables optimization of combinations to achieve desired responses. It also allows identifying critical nodes mediating the multi-signal induced responses. The concept and the approach used in this work will be directly applicable to other diseases such as AIDS and cancer
Significant decrease of maternal mitochondria carryover using optimized spindle-chromosomal complex transfer.
Mutations in mitochondrial DNA (mtDNA) contribute to a variety of serious multi-organ human diseases, which are strictly inherited from the maternal germline. However, there is currently no curative treatment. Attention has been focused on preventing the transmission of mitochondrial diseases through mitochondrial replacement (MR) therapy, but levels of mutant mtDNA can often unexpectedly undergo significant changes known as mitochondrial genetic drift. Here, we proposed a novel strategy to perform spindle-chromosomal complex transfer (SCCT) with maximal residue removal (MRR) in metaphase II (MII) oocytes, thus hopefully eliminated the transmission of mtDNA diseases. With the MRR procedure, we initially investigated the proportions of mtDNA copy numbers in isolated karyoplasts to those of individual oocytes. Spindle-chromosomal morphology and copy number variation (CNV) analysis also confirmed the safety of this method. Then, we reconstructed oocytes by MRR-SCCT, which well developed to blastocysts with minimal mtDNA residue and normal chromosomal copy numbers. Meanwhile, we optimized the manipulation order between intracytoplasmic sperm injection (ICSI) and SCC transfer and concluded that ICSI-then-transfer was conducive to avoid premature activation of reconstructed oocytes in favor of normal fertilization. Offspring of mice generated by embryos transplantation in vivo and embryonic stem cells derivation further presented evidences for competitive development competence and stable mtDNA carryover without genetic drift. Importantly, we also successfully accomplished SCCT in human MII oocytes resulting in tiny mtDNA residue and excellent embryo development through MRR manipulation. Taken together, our preclinical mouse and human models of the MRR-SCCT strategy not only demonstrated efficient residue removal but also high compatibility with normal embryo development, thus could potentially be served as a feasible clinical treatment to prevent the transmission of inherited mtDNA diseases
Effect of Logarithmically Transformed IMERG Precipitation Observations in WRF 4D-Var Data Assimilation System
Precipitation estimates from numerical weather prediction (NWP) models are uncertain. The uncertainties can be reduced by integrating precipitation observations into NWP models. This study assimilates Version 04 Integrated Multi-satellite Retrievals for the Global Precipitation Measurement (GPM) (IMERG) Final Run into the Weather Research and Forecasting (WRF) model data assimilation (WRFDA) system using a four-dimensional variational (4D-Var) method. Three synoptic-scale convective precipitation events over the central United States during 2015–2017 are used as case studies. To investigate the effect of logarithmically transformed IMERG precipitation in the WRFDA system, this study reports on several experiments with six-hour and hourly assimilation windows, regular (nontransformed) and logarithmically transformed observations, and a constant observation error in regular and logarithmic spaces. Results show that hourly assimilation windows improve precipitation simulations significantly compared to six-hour windows. Logarithmically transformed precipitation does not improve precipitation estimations relative to nontransformed precipitation. However, better predictions of heavy precipitation can be achieved with a constant error in the logarithmic space (corresponding to a linearly increasing error in the regular space), which modifies the threshold of rejecting observations, and thus utilizes more observations. This study provides a cost function with logarithmically transformed observations for the 4D-Var method in the WRFDA system for future investigations
Green-Building-Material Supplier Selection with a Rough-Set-Enhanced Quality Function Deployment
Building material supplier evaluation and selection is a significant strategic-decision problem for reducing construction costs and ensuring the quality of a residential product. As people are increasingly concerning about the green level of a residential product and the competition in the housing market is becoming increasingly fierce, it becomes important to select a green customer-oriented material supplier for property developers. Quality function deployment (QFD) has been proven to be an effective quality-control technique to take customer voices into consideration. However, the relationship matrix in the QFD technique, as a key to translate customer requirements into technical attributes, was subjectively given by decision-makers in previous studies, which failed to reflect customer requirements accurately. The aim of this study is to put forward a neighborhood-rough-set-based quality function deployment model for a green-building-material supplier selection. The neighborhood rough set, as a nonparametric and flexible data-mining approach, can effectively and objectively determine the core relationships between a variety of factors. A rough number-based aggregation approach is applied to effectively and objectively aggregate the evaluations given by a group of experts. Then, the classical double normalization-based multiple aggregation method, which considers two types of normalization methods, three aggregation models, and a comprehensive score formula, is extended in rough-number form in order to rank the alternatives. Afterward, an attempt is made to evaluate and rank eleven alternative building-material suppliers for a repute property developer in mainland China, and the corresponding comparative and sensitive analyses verify the effectiveness and robustness of the proposed hybrid model
Purification and Structural Characterization of a Novel Water-Soluble Neutral Polysaccharide from Cantharellus cibarius and Its Immunostimulating Activity in RAW264.7 Cells
Polysaccharide is one of the important active ingredients of Cantharellus cibarius. The aims of this work were to analyze preliminary characterization and to investigate immunostimulating activity of a novel water-soluble neutral polysaccharide named JP1, which was purified from the fruiting body of Cantharellus cibarius using DEAE-FF chromatography and Sephadex G-100 chromatography. The characteristics of JP1 were determined by HPGPC, FT-IR spectra, gas chromatography, and Congo Red Method. Immunostimulating activity of JP1 was investigated in RAW264.7 cells. Results indicated that JP1 consisted of L-Arabinose, D-Mannose, D-Glucose, and D-Galactose in a molar ratio of 1 : 1.06 : 1.95 : 1.17 with a molecular weight of 336 kDa. JP1 is nontoxic to RAW264.7 cells at this concentration range (62.5–1000 μg/mL). Furthermore, JP1 can promote mouse peritoneal macrophages to secrete NO and enhance the secretion of macrophages’ cytokines IL-6 in RAW264.7 cells. These results suggested that JP1 could have potential immunostimulating activity applications as medicine or functional food
Facilitating Lithium-Ion Diffusion in Layered Cathode Materials by Introducing Li+/Ni2+ Antisite Defects for High-Rate Li-Ion Batteries
Li+/Ni2+ antisite defects mainly resulting from their similar ionic radii in the layered nickel-rich cathode materials belong to one of cation disordering scenarios. They are commonly considered harmful to the electrochemical properties, so a minimum degree of cation disordering is usually desired. However, this study indicates that LiNi0.8Co0.15Al0.05O2 as the key material for Tesla batteries possesses the highest rate capability when there is a minor degree (2.3%) of Li+/Ni2+ antisite defects existing in its layered structure. By combining a theoretical calculation, the improvement mechanism is attributed to two effects to decrease the activation barrier for lithium migration: (1) the anchoring of a low fraction of high-valence Ni2+ ions in the Li slab pushes uphill the nearest Li+ ions and (2) the same fraction of low-valence Li+ ions in the Ni slab weakens the repulsive interaction to the Li+ ions at the saddle point
Changes in Cardiovascular Health during Young Adulthood and Subclinical Atherosclerosis in Middle Age: The CARDIA Study
Background and aims: The benefits of reaching ideal cardiovascular health (CVH) are well known, but it is unclear whether positive CVH changes from young adulthood to middle age reduce subclinical atherosclerosis risk. This study examined associations of changes in CVH from young adulthood to middle age and CVH in young adulthood with subclinical atherosclerosis. Methods: Data was analyzed from the Coronary Artery Risk Development in Young Adults (CARDIA) study. CVH was examined at years 0 and 20 using Life Simple 7 metrics from AHA guideline. Coronary artery calcium (CAC) was identified at years 20 and 25. Carotid intima-media thickness (IMT) was identified at year 20. Results: Among 2,935 participants (56.2% women, 46.7% black), the change of CVH score was –1.26 (2.13). For per 1-unit increase in CVH at baseline, the adjusted odds ratios (ORs) of presence of CAC and IMT were 0.81 (95% CI 0.78, 0.86) and 0.85 (95% CI 0.76, 0.94), respectively. For per 1-unit increase in CVH changes, the adjusted ORs of CAC and IMT were 0.86 (95% CI 0.82, 0.90) and 0.81 (95% CI 0.73, 0.90). Compared with stable moderate CVH, improvement from moderate to high was associated with a lower risk of CAC (0.64 [95% CI 0.43, 0.96]), while retrogression from moderate to low was associated with a higher risk of CAC (1.45 [95% CI 1.19, 1.76]). Conclusions: Positive changes of CVH during young adulthood are associated with negative subclinical atherosclerosis risk in middle age, indicating the importance of reaching an ideal cardiovascular health status through young adulthood
- …