Математическое моделирование формирования мерцательной аритмии сердца человека

This paper deals with the modeling of the electrical system of the human cardiac tissue. The paper’s aim is creation of the model, which geometrical structure is closed to the actual geometry of the human heart. The processes occurring in the heart muscle are modeled by solving a system of nonlinear differential equations in COMSOL Multiphysics

SLPD: Slide-level Prototypical Distillation for WSIs

Improving the feature representation ability is the foundation of many whole slide pathological image (WSIs) tasks. Recent works have achieved great success in pathological-specific self-supervised learning (SSL). However, most of them only focus on learning patch-level representations, thus there is still a gap between pretext and slide-level downstream tasks, e.g., subtyping, grading and staging. Aiming towards slide-level representations, we propose Slide-Level Prototypical Distillation (SLPD) to explore intra- and inter-slide semantic structures for context modeling on WSIs. Specifically, we iteratively perform intra-slide clustering for the regions (4096x4096 patches) within each WSI to yield the prototypes and encourage the region representations to be closer to the assigned prototypes. By representing each slide with its prototypes, we further select similar slides by the set distance of prototypes and assign the regions by cross-slide prototypes for distillation. SLPD achieves state-of-the-art results on multiple slide-level benchmarks and demonstrates that representation learning of semantic structures of slides can make a suitable proxy task for WSI analysis. Code will be available at https://github.com/Carboxy/SLPD.Comment: International Conference on Medical Image Computing and Computer Assisted Intervention (MICCAI

Strict Efficiency in Vector Optimization with Nearly Convexlike Set-Valued Maps

The concept of the well posedness for a special scalar problem is linked with strictly efficient solutions of vector optimization problem involving nearly convexlike set-valued maps. Two scalarization theorems and two Lagrange multiplier theorems for strict efficiency in vector optimization involving nearly convexlike set-valued maps are established. A dual is proposed and duality results are obtained in terms of strictly efficient solutions. A new type of saddle point, called strict saddle point, of an appropriate set-valued Lagrange map is introduced and is used to characterize strict efficiency

Causality of particulate matter on cardiovascular diseases and cardiovascular biomarkers

BackgroundPrevious observational studies have shown that the prevalence of cardiovascular diseases (CVDs) is related to particulate matter (PM). However, given the methodological limitations of conventional observational research, it is difficult to identify causality conclusively. To explore the causality of PM on CVDs and cardiovascular biomarkers, we conducted a Mendelian randomization (MR) analysis.MethodIn this study, we obtained summary-level data for CVDs and cardiovascular biomarkers including atrial fibrillation (AF), heart failure (HF), myocardial infarction (MI), ischemic stroke (IS), stroke subtypes, body mass index (BMI), lipid traits, fasting glucose, fasting insulin, and blood pressure from several large genome-wide association studies (GWASs). Then we used two-sample MR to assess the causality of PM on CVDs and cardiovascular biomarkers, 16 single nucleotide polymorphisms (SNPs) for PM2.5 and 6 SNPs for PM10 were obtained from UK Biobank participants. Inverse variance weighting (IVW) analyses under the fixed effects model were used as the main analytical method to calculate MR Estimates, followed by multiple sensitivity analyses to confirm the robustness of the results.ResultsOur study revealed increases in PM2.5 concentration were significantly related to a higher risk of MI (odds ratio (OR), 2.578; 95% confidence interval (CI), 1.611–4.127; p = 7.920 × 10−5). Suggestive evidence was found between PM10 concentration and HF (OR, 2.015; 95% CI, 1.082–3.753; p = 0.027) and IS (OR, 2.279; 95% CI,1.099–4.723; p = 0.027). There was no evidence for an effect of PM concentration on other CVDs. Furthermore, PM2.5 concentration increases were significantly associated with increases in triglyceride (TG) (OR, 1.426; 95% CI, 1.133–1.795; p = 2.469 × 10−3) and decreases in high-density lipoprotein cholesterol (HDL-C) (OR, 0.779; 95% CI, 0.615–0.986; p = 0.038). The PM10 concentration increases were also closely related to the decreases in HDL-C (OR, 0.563; 95% CI, 0.366–0.865; p = 8.756 × 10−3). We observed no causal effect of PM on other cardiovascular biomarkers.ConclusionAt the genetic level, our study suggested the causality of PM2.5 on MI, TG, as well HDL-C, and revealed the causality of PM10 on HF, IS, and HDL-C. Our findings indicated the need for continued improvements in air pollution abatement for CVDs prevention

Comparative Genomic Analysis Reveals Extensive Genetic Variations of WRKYs in Solanaceae and Functional Variations of CaWRKYs in Pepper

As a conserved protein family, WRKY has been shown to be involved in multiple biological processes in plants. However, the mechanism of functional diversity for WRKYs in pepper has not been well elucidated. Here, a total of 223 WRKY members from solanaceae crops including pepper, tomato and potato, were analyzed using comparative genomics. A tremendous genetic variation among WRKY members of different solanaceous plants or groups was demonstrated by the comparison of some WRKY features, including number/size, group constitution, gene structure, and domain composition. The phylogenetic analysis showed that except for the known WRKY groups (I, IIa/b/c/d/e and III), two extra WRKY subgroups specifically existed in solanaceous plants, which were named group IIf and group IIg in this study, and their genetic variations were also revealed by the characteristics of some group IIf and IIg WRKYs. Except for the extensive genetic variations, certain degrees of conservatism for solanaceae WRKYs were also revealed. Moreover, the variant zinc-finger structure (CX4,7CX22-24HXC) in group III of solanaceae WRKYs was identified. Expression profiles of CaWRKY genes suggested their potential roles in pepper development and stress responses, and demonstrated a functional division pattern for pepper CaWRKYs. Furthermore, functional analysis using virus induced gene silencing (VIGS) revealed critical roles of two CaWRKYs (CaWRKY45 and CaWRKY58) in plant responses to disease and drought, respectively. This study provides a solid foundation for further dissection of the evolutionary and functional diversity of solanaceae WRKYs in crop plants

Causality of anti-Helicobacter pylori IgG levels on myocardial infarction and potential pathogenesis: a Mendelian randomization study

BackgroundPrevious observational studies have shown that a potential relationship between anti-Helicobacter pylori (H. pylori) IgG levels and Myocardial Infarction (MI). Nevertheless, the evidence for the causal inferences remains disputable. To further clarify the relationship between anti-H. pylori IgG levels and MI and explore its pathogenesis, we conducted a Mendelian randomization (MR) analysis.MethodsIn this study, we used two-sample Mendelian Randomization (MR) to assess the causality of anti-H. pylori IgG levels on MI and potential pathogenesis, 12 single nucleotide polymorphisms (SNPs) related to anti-H. pylori IgG levels were obtained from the European Bioinformatics Institute (EBI). Summary data from a large-scale GWAS meta-analysis of MI was utilized as the outcome dataset. Summary data of mediators was obtained from the FinnGen database, the UK Biobank, the EBI database, MRC-IEU database, the International Consortium of Blood Pressure, the Consortium of Within family GWAS. Inverse variance weighted (IVW) analysis under the fixed effect model was identified as our main method. To ensure the reliability of the findings, many sensitivity analyses were performed.ResultsOur study revealed that increases of anti-H. pylori IgG levels were significantly related to an increased risk of MI (OR, 1.104; 95% CI,1.042–1.169; p = 7.084 × 10−4) and decreases in HDL cholesterol levels (β, −0.016; 95% CI, −0.026 to −0.006; p = 2.02 × 10−3). In addition, there was no heterogeneity or pleiotropy in our findings.ConclusionThis two-sample MR analysis revealed the causality of anti-H. pylori IgG levels on MI, which might be explained by lower HDL cholesterol levels. Further research is needed to clarify the results

High invertase activity in tomato reproductive organs correlates with enhanced sucrose import into, and heat tolerance of, young fruit

Heat stress can cause severe crop yield losses by impairing reproductive development. However, the underlying mechanisms are poorly understood. We examined patterns of carbon allocation and activities of sucrose cleavage enzymes in heat-tolerant (HT) and -sensitive (HS) tomato (Solanum lycopersicum L.) lines subjected to normal (control) and heat stress temperatures. At the control temperature of 25/20 °C (day/night) the HT line exhibited higher cell wall invertase (CWIN) activity in flowers and young fruits and partitioned more sucrose to fruits but less to vegetative tissues as compared to the HS line, independent of leaf photosynthetic capacity. Upon 2-, 4-, or 24-h exposure to day or night temperatures of 5 °C or more above 25/20 °C, cell wall (CWIN) and vacuolar invertases (VIN), but not sucrose synthase (SuSy), activities in young fruit of the HT line were significantly higher than those of the HS line. The HT line had a higher level of transcript of a CWIN gene, Lin7, in 5-day fruit than the HS line under control and heat stress temperatures. Interestingly, heat induced transcription of an invertase inhibitor gene, INVINH1, but reduced its protein abundance. Transcript levels of LePLDa1, encoding phospholipase D, which degrades cell membranes, was less in the HT line than in the HS line after exposure to heat stress. The data indicate that high invertase activity of, and increased sucrose import into, young tomato fruit could contribute to their heat tolerance through increasing sink strength and sugar signalling activities, possibly regulating a programmed cell death pathway

SystemC based Behavioral Modeling and Virtual Prototyping of RF SoCs

Today’s multi-standard multi-band mobile terminals are enabled by the increased complexity of RF-SoCs. Multi-band multi-mode RF frontends based on DigitalRF-architectures using extensive self-calibration/compensation schemes have to be realized in nanoscale CMOS nodes. Pre-tapeout verification is a key challenge for this kind of RF-SoCs as conventional circuit/transistor-level simulations using Fast-Spice are not able to cover the requirements. The only left practical solution is the behavioral modeling based method based on event driven data flow simulation techniques. The purpose of this thesis is to enhance the effectiveness of the behavioral modeling method in functional verification of RF SoCs by introducing a RF virtual prototyping (RF VP) technique. The idea of RF VP is to use pin-compatible behavioral models to replace RF and mixed-signal parts of the RF SoCs. The models are required to be digital simulator supported, and close linked with the latest snapshot of the circuit behaviors. This technique aims to provide high simulation efficient and accuracy-guaranteed solution to RF SoCs verification. It involves how to describe analog behaviors in digital way, how to increase simulation speed by switching to another signal abstraction, how to reduce manual modeling efforts and human errors by self-developed EDA tools, and etc. In this thesis, SystemC is chosen as modeling language for the RF VP due to the high simulation efficiency, the syntax flexibility, and the good integration into digital RTL simulation tools. Most of all, it is selected due to its order of freedom, which is referred to the ability to cross levels of abstractions of the models. Higher order of freedom means more space to make the trade-off between simulation speed and verification accuracy/coverage, which is the basic trick in response to the huge increase of the complexity. Further discussions are expanded on the detailed behavioral modeling methods using SystemC. With event-driven method, the analog behavior can be modeled as a signal flow without solving differential equations. In order to speed up simulations, an improved baseband modeling method covering up to 3rd order harmonics is used. The model can be switched to baseband signal abstraction without carrier distortion. This baseband method is further extended to carry a vector of spectral components: more accurate but still high simulation efficient. By using a mixed-domain modeling method, a new signal abstraction is invented to bridge the behavioral description in baseband time domain and baseband frequency domain. To certain structure like PLL with feedback path, an event-shooting method is applied to compensate the unexpected feedback path delay when using the baseband signal abstraction. The case in modeling supply noise reveals that these modeling methods in SystemC can extend the modeling coverage from the main circuit functional behaviors to some other performance related behavior. SystemC RF VP technique is enabled on the basis of these modeling methods. Further, a set of self-developed toolsets/concepts are introduced to automate the RF virtual prototyping process. A lot of handcrafting efforts are saved and moreover many human errors are avoided by these toolsets starting from model netlisting, block level modeling/self-checking, model parameters extraction, to RF VP models generation and system simulation management. Two industry level test cases are used as the applications of the proposed methods in functional verification of RF SoCs. One is for a GNSS receiver front-end. Another is for a short-range low energy transceiver front-end. From the simulation results, these techniques can achieve a great simulation speed up (maximum to 105 speed up comparing to SPICE based analog simulations), while the simulation correctness is still reserved and the modeling effort is greatly reduced