587 research outputs found
Investigation of ultra-thin Al₂O₃ film as Cu diffusion barrier on low-k (k=2.5) dielectrics
Ultrathin Al(2)O(3) films were deposited by PEALD as Cu diffusion barrier on low-k (k=2.5) material. The thermal stability and electrical properties of the Cu/low k system with Al(2)O(3) layers with different thickness were studied after annealing. The AES, TEM and EDX results revealed that the ultrathin Al(2)O(3) films are thermally stable and have excellent Cu diffusion barrier performance. The electrical measurements of dielectric breakdown and TDDB tests further confirmed that the ultrathin Al(2)O(3) film is a potential Cu diffusion barrier in the Cu/low-k interconnects system
Bottom-up GGM algorithm for constructing multilayered hierarchical gene regulatory networks that govern biological pathways or processes
Background: Multilayered hierarchical gene regulatory networks (ML-hGRNs) are very important for understanding genetics regulation of biological pathways. However, there are currently no computational algorithms available for directly building ML-hGRNs that regulate biological pathways.
Results: A bottom-up graphic Gaussian model (GGM) algorithm was developed for constructing ML-hGRN operating above a biological pathway using small- to medium-sized microarray or RNA-seq data sets. The algorithm first placed genes of a pathway at the bottom layer and began to construct an ML-hGRN by evaluating all combined triple genes: two pathway genes and one regulatory gene. The algorithm retained all triple genes where a regulatory gene significantly interfered two paired pathway genes. The regulatory genes with highest interference frequency were kept as the second layer and the number kept is based on an optimization function. Thereafter, the algorithm was used recursively to build a ML-hGRN in layer-by-layer fashion until the defined number of layers was obtained or terminated automatically.
Conclusions: We validated the algorithm and demonstrated its high efficiency in constructing ML-hGRNs governing biological pathways. The algorithm is instrumental for biologists to learn the hierarchical regulators associated with a given biological pathway from even small-sized microarray or RNA-seq data sets
荆州区农村人口初发糖尿病胰岛功能的现状跟踪调查*
Objective: To study the change of islet function in patients with incipient diabetic characteristics through incipient diabetic tracking observation of the islet function in patients of Jingzhou area. Methods: Selection of 1220 cases of patients with diabetes mellitus in Jingzhou area as research object at the beginning, 12 months follow-up, the clinic after 3 months, 6 months and 12 months, all patients to detect blood sugar change, c-peptide release quantity, calculate insulin secretion index (HOMA -β) and insulin resistance index (HOMA IR), summarizes the characteristic of islet function in patients with changes. Results: ① The patients restored to basic standard blood sugar in 3 months by drug treatment, and the patient's blood glucose levels not seen obvious fluctuation after 6 months and 12 months; ② During follow-up, patients with diabetes sustained c-peptide release quantity reduction, and in three months after treatment, c-peptide release decreased obviously, and see a doctor at 6 months and 12 months after the comparison, the difference was statistically significant (P < 0.05). ③ During follow-up, insulin capacity was decreasing among patients with diabetes, within three months after the doctor had the greatest reduction, the difference was statistically significant (P < 0.05); ④ During follow-up, island hormone decreasing index, insulin resistance index continued to rise among patients with diabetes, and 6 months and 12 months, the most significant variations in 3 months (P < 0.05). Conclusion: With the extension of course, the pancreatic islet function in patients with early onset diabetes decreased gradually. It could be proved that there is a significant correlation between the two and especially seen in obvious function decline of pancreatic islets among the patients within 3 months.目的 通过对荆州区初发糖尿病患者的胰岛功能进行跟踪观察,探讨发现初发糖尿病患者胰岛功能的变化特点。方法 选取荆州区1220例初发糖尿病患者作为观察对象,跟踪随访12个月,在就诊后的3个月、6个月及12个月时,全部患者检测血糖变化、C-肽释放量,计算胰岛素分泌指数(HOMA-β)及胰岛素抵抗指数(HOMA-IR),观察总结患者的胰岛功能变化特点。结果 (1)通过药物治疗,患者血糖在3个月时基本达标,6个月及12个月时,患者的血糖水平未见明显波动;(2)随访期间,糖尿病患者C-肽释放量持续降低,且在就诊后3个月内,C-肽释放量下降明显,与就诊后6个月时及12个月时比较,差异有统计学意义(P<0.05)。(3)随访期间,糖尿病患者胰岛素放量持续降低,就诊后3个月内下降最明显,差异有统计学意义(P<0.05);(4)随访期间,糖尿病患者胰岛素分泌指数持续降低,胰岛素抵抗指数持续升高,且与6个月时和12个月时比较,3个月时变化幅度最为显著(P<0.05)。结论 随着病程的延长,初发糖尿病患者胰岛功能逐渐降低,二者具有显著相关性,且3个月内患者的胰岛功能下降最为显著
Differential Strategies to Tolerate Flooding in Polygonum hydropiper Plants Originating From Low- and High-Elevation Habitats
In species that occur over a wide range of flooding conditions, plant populations may have evolved divergent strategies as a consequence of long-term adaptation to local flooding conditions. In the present study, we investigated the effects of a flooding gradient on the growth and carbohydrate reserves of Polygonum hydropiper plants originating from low- and high-elevation habitats in the Dongting Lake wetlands. The results indicated that shoot length did not differ, whereas the total biomass and carbohydrate reserves were reduced under flooded compared to well-drained conditions for plants originating from both habitat types. However, shoot length, shoot mass, rhizome mass, and total biomass were lower in plants from low-elevation habitats than in those from high-elevation habitats in the flooded condition. Soluble sugar and starch contents in belowground biomass were higher in plants from low-elevation habitats than in those from high-elevation habitats independently of the water level. Therefore, P. hydropiper plants from low-elevation habitats exhibit a lower growth rate and more conservative energy strategy to cope with flooding in comparison with plants from high-elevation habitats. Differential strategies to cope with flooding among P. hydropiper populations are most likely a response to the flooding pressures of the habitat of origin and may potentially drive ecotype differentiation within species along flooding gradients
Cardioprotective effect of curcumin on myocardial ischemia/reperfusion injury: a meta-analysis of preclinical animal studies
Objective: This meta-analysis aimed to determine the efficacy of curcumin in preventing myocardial ischemia/reperfusion (I/R) injury in animal models.Methods: Studies published from inception to January 2023 were systematically searched in databases including PubMed, Web of Science, Embase, China’s National Knowledge Infrastructure (CNKI), Wan-Fang database, and VIP database (VIP). The SYRCLE’s RoB tool was used to determine methodological quality. Sensitivity analysis and subgroup analysis were performed when there was high heterogeneity. Publication bias was assessed using a funnel plot.Results: Thirty-seven studies involving 771 animals were included in this meta-analysis with methodology quality scores ranging from 4 to 7. The results indicated that curcumin treatment significantly improved myocardial infarction size standard mean difference (SMD) = −5.65; 95% confidence interval (CI): 6.94, −4.36; p < 0.01; I2 = 90%). The sensitivity analysis for infarct size showed that the results were stable and reliable. However, the funnel plot was asymmetric. The subgroup analysis included species, animal model, dose, administration, and duration. The results showed that the subgroup dose was statistically significant between subgroups. In addition, curcumin treatment improved cardiac function, myocardial injury enzymes, and oxidative stress levels in animal models of myocardial I/R injury. The funnel plot revealed that there is publication bias for creatine kinase and lactate dehydrogenase. Finally, we performed a meta-analysis of inflammatory cytokines and apoptosis index. The results showed that curcumin treatment downregulated serum inflammatory cytokine levels and myocardial apoptosis index.Conclusion: This meta-analysis suggests that curcumin has excellent potential for the treatment of myocardial I/R injury in animal models. However, this conclusion needs to be further discussed and verified in large animal models and human clinical trials.Systematic Review Registration:https://www.crd.york.ac.uk/prospero/, identifier CRD42022383901
Application of microfluidic chips in anticancer drug screening
With the continuous development of drug screening technology, new screening methodologies and technologies are constantly emerging, driving drug screening into rapid, efficient and high-throughput development. Microfluidics is a rising star in the development of innovative approaches in drug discovery. In this article, we summarize the recent years' progress of microfluidic chip technology in drug screening, including the developmental history, structural design, and applications in different aspects of microfluidic chips on drug screening. Herein, the existing microfluidic chip screening platforms are summarized from four aspects: chip structure design, sample injection and drive system, cell culture technology on a chip, and efficient remote detection technology. Furthermore, this review discusses the application and developmental prospects of using microfluidic chips in drug screening, particularly in screening natural product anticancer drugs based on chemical properties, pharmacological effects, and drug cytotoxicity.Peer reviewe
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