Association Between Vascular Adhesion Protein-1 (VAP-1) and MACE in Patients with Coronary Heart Disease: A Cohort Study.

Background: Vascular adhesion protein-1 (VAP-1), an inflammation-inducible endothelial cell molecule, was reported to be implicated in a variety of cardiovascular diseases. However, the clinical significance of circulating VAP-1 levels in patients with coronary heart disease (CHD) remains less studied. Patients and Methods: We retrospectively analyzed clinical data of 336 hospitalized patients in the Second Affiliated Hospital of Soochow University from May 2020 to September 2022, 174 of which were diagnosed with CHD. Serum VAP-1 was measured by enzyme-linked immunosorbent assay at enrollment. The primary end point of this study was the occurrence of major adverse cardiovascular events (MACE). The coronary stenosis and clinical manifestations of CHD were assessed and recorded from medical records or follow-up calls. The relevant results were obtained, and the reliability of the conclusions was verified through regression analysis, curve fitting, and survival curve. Results: After adjusting for potential confounders, higher serum VAP-1 level was associated with increased risk of MACE in patients with CHD [(HR = 5.11, 95% CI = 1.02-25.59), (HR = 5.81, 95% CI = 1.16-29.11)]. The results of curve fitting and survival analysis were consistent with those of regression analysis. However, no significant association was observed between VAP-1 and MACE in the entire study population [(HR = 5.11, 95% CI = 0.41-1.93), (HR = 1.17, 95% CI = 0.52-2.62)]. Furthermore, the level of VAP-1 did not show a significant correlation with coronary stenosis and the clinical manifestations of CHD. Conclusion: These findings suggested that CHD patients with higher serum levels of VAP-1 are at a higher risk of adverse cardiovascular outcomes.

SEU Hardened D Flip-Flop Design with Low Area Overhead.

D flip-flop (DFF) is the basic unit of sequential logic in digital circuits. However, because of an internal cross-coupled inverter pair, it can easily appear as a single event upset (SEU) when hit by high-energy particles, resulting in the error in the value stored in the flip-flop. On this basis, a new structure D flip-flop is proposed in this paper. This flip-flop uses an asymmetric scheme in which the master-slave latch adopts different hardening structures. By sacrificing circuit speed in exchange for stronger SEU fortification capability, the SEU threshold of this structure is improved by 10 times compared to traditional D flip-flops. It has also been compared with Dual Interlocked Storage Elements (DICEs), and it saves the area cost of six transistors compared to the DICE structure. Under the same operating conditions, the average power consumption and peak power consumption are, respectively, 9.8% and 18.8% lower than those of the DICE circuit, making it suitable for soft radiation environments where high circuit speed is not a critical requirement.

A Single-Event-Hardened Scheme for Ring Oscillator Applied to Radiation-Resistant PLL Microsystems.

A voltage-controlled oscillator (VCO) is one of the key modules of the phase-locked loop (PLL) microsystem, and it is easy to bombard using high-energy particles in a radiation environment, resulting in the single-event effect. In order to improve the anti-radiation ability of the PLL microsystems used in the aerospace environment, a new voltage-controlled oscillator hardened circuit is proposed in this work. The circuit consists of delay cells with an unbiased differential series voltage switch logic structure with a tail current transistor. By reducing sensitive nodes and using the positive feedback of the loop, the recovery process of the VCO circuit to the single-event transient (SET) is reduced and accelerated, so as to reduce the sensitivity of the circuit to the single-event effect. The simulation results based on the SMIC 130 nm complementary metal-oxide-semiconductor (CMOS) process show that the maximum phase shift difference of the PLL with the hardened VCO is reduced by 53.5%, which shows that the hardened VCO structure can reduce the sensitivity of the PLL to the SET and improve the reliability of the PLL in the radiation environment.

A Single-Event-Hardened Scheme of Phase-Locked Loop Microsystems for Aerospace Applications.

In order to improve the ability of the phase-locked loop (PLL) microsystem applied in the aerospace environment to suppress the irradiation effect, this study presents an efficient charge pump hardened scheme by using the radiation-hardened-by-design (RHBD) technology. In this study, the sensitivity analysis of the single-event transient (SET) at different nodes of charge pump and different bombardment energies is carried out. Without changing the original structure and loop parameters, a hardened scheme of phase-locked loop to suppress the single-event effect is proposed. A digital control circuit is added between the charge pump and low-pass filter, which greatly reduces the sensitivity of the charge pump to the SET. The classical double-exponential current pulse model is used to simulate the SET effect on the unreinforced and reinforced phase-locked loops, and the reliability of the proposed reinforcement scheme is verified. The simulation results based on the SMIC 130 nm standard complementary metal-oxide-semiconductor (CMOS) process show that the peak value of the transient response fluctuation of the phase-locked loop using the proposed single-event-hardened scheme decreased by 94.2%, the lock recovery time increased by 75.3%, and the maximum phase shift decreased by 90.8%. This shows that the hardened scheme can effectively reduce the sensitivity of the PLL microsystems to the SET effects.

High-Performance and Flexible Design Scheme with ECC Protection in the Cache.

To improve the reliability of static random access memory (SRAM), error-correcting codes (ECC) are typically used to protect SRAM in the cache. While improving the reliability, we also need additional circuits to support ECC, including encoding and decoding logic. In a high-speed circuit such as a CPU, the L1 cache maintains the same frequency as the CPU, and the decoding of the ECC codes in the cache consumes considerable combinational logic, resulting in limited frequency and performance. This study proposes a high-performance and flexible design scheme with ECC protection in the cache, in which the cache has two working modes: a high-performance mode and a high-reliability mode. The high-performance mode uses simple ECC codes, which can maintain high frequency with low access latency. The high-reliability mode uses more complex ECC codes, which improves the error correction capability and enhances the reliability of the SRAM. To meet the application requirements of different scenarios, the proposed scheme supports the software in switching between the above two modes by configuring the register, which improves the flexibility of the system. The results of synthesis show that the theoretical maximum frequency of proposed ECC design scheme increased from approximately 1.4 GHz in the conventional ECC design scheme to approximately 2.2 GHz. Some of the error correction capability of the high-performance mode is traded off against a 57% increase in frequency. In the high-reliability mode, the error correction capability of the SRAM is enhanced; however, the latency of accessing the cache increases by one cycle.

Vector-based pedestrian navigation in cities.

How do pedestrians choose their paths within city street networks? Researchers have tried to shed light on this matter through strictly controlled experiments, but an ultimate answer based on real-world mobility data is still lacking. Here, we analyze salient features of human path planning through a statistical analysis of a massive dataset of GPS traces, which reveals that (1) people increasingly deviate from the shortest path when the distance between origin and destination increases and (2) chosen paths are statistically different when origin and destination are swapped. We posit that direction to goal is a main driver of path planning and develop a vector-based navigation model; the resulting trajectories, which we have termed pointiest paths, are a statistically better predictor of human paths than a model based on minimizing distance with stochastic effects. Our findings generalize across two major US cities with different street networks, hinting to the fact that vector-based navigation might be a universal property of human path planning.

Methane emissions reduce the radiative cooling effect of a subtropical estuarine mangrove wetland by half.

The role of coastal mangrove wetlands in sequestering atmospheric carbon dioxide (CO2 ) and mitigating climate change has received increasing attention in recent years. While recent studies have shown that methane (CH4 ) emissions can potentially offset the carbon burial rates in low-salinity coastal wetlands, there is hitherto a paucity of direct and year-round measurements of ecosystem-scale CH4 flux (FCH4 ) from mangrove ecosystems. In this study, we examined the temporal variations and biophysical drivers of ecosystem-scale FCH4 in a subtropical estuarine mangrove wetland based on 3 years of eddy covariance measurements. Our results showed that daily mangrove FCH4 reached a peak of over 0.1 g CH4 -C m-2  day-1 during the summertime owing to a combination of high temperature and low salinity, while the wintertime FCH4 was negligible. In this mangrove, the mean annual CH4 emission was 11.7 ± 0.4 g CH4 -C m-2  year-1 while the annual net ecosystem CO2 exchange ranged between -891 and -690 g CO2 -C m-2  year-1 , indicating a net cooling effect on climate over decadal to centurial timescales. Meanwhile, we showed that mangrove FCH4 could offset the negative radiative forcing caused by CO2 uptake by 52% and 24% over a time horizon of 20 and 100 years, respectively, based on the corresponding sustained-flux global warming potentials. Moreover, we found that 87% and 69% of the total variance of daily FCH4 could be explained by the random forest machine learning algorithm and traditional linear regression model, respectively, with soil temperature and salinity being the most dominant controls. This study was the first of its kind to characterize ecosystem-scale FCH4 in a mangrove wetland with long-term eddy covariance measurements. Our findings implied that future environmental changes such as climate warming and increasing river discharge might increase CH4 emissions and hence reduce the net radiative cooling effect of estuarine mangrove forests.

Climate-Conscious Urban Growth Mitigates Urban Warming: Evidence from Shenzhen, China.

Urban growth comes with significant warming impacts and related increases in air pollution concentrations, so many cities have implemented growth management to minimize "sprawl" and its environmental consequences. However, controlling the amount of growth is costly. Therefore, in this Article, we focus on urban warming and investigate whether climate-conscious urban growth planning (CUGP), that is, urban growth with the same magnitude but optimized spatial arrangements, brings significant mitigation effects. First, the classical spatial multiobjective land-use optimization (SMOLA) model is improved by integrating the spatially, diurnally, and compositionally varying associations between land-use and their warming impacts. We then solve the improved model using the nondominated genetic algorithm (NSGA-II) to generate urban growth plans with minimal warming impacts and minimal cost of change without reducing the amount of urban growth. Results show that climate-conscious urban growth brings 33.3 ± 4.6% less warming impacts as compared to unplanned urban growth in Shenzhen, China, and suggest a compact and spatially equalized development pattern. This study provides evidence that spatial planning tools such as the CUGP can help mitigate human impacts on the environment. Meanwhile, the improved SMOLA model could be applied to balance urban development and other environmental consequences such as air pollution.

The impact of urbanization on air stagnation: Shenzhen as case study.

One of the most concerning consequences arising from the dramatic urbanization in cities is air stagnation and the related high concentration of air pollutants. Many studies have investigated the impact of urbanization on air stagnation, but few have systematically evaluated such impact and its spatial-temporal variances at the municipal scale. This study proposed an approach based on high-resolution urban climate simulations for evaluating the impact of urbanization on air stagnation. We took the city of Shenzhen in south-eastern China, a city that grew from a small fishing and farming village to a highly urbanized city in the past thirty years, as a compelling case study. Using the WRF/Noah LSM/SLUCM model, we simulated and evaluated the probability of 6-hourly air stagnation cases (ASCs) in 1979 and 2010 at the spatial resolution of 1-km2 to demonstrate the change over a thirty-year period. Comparison results show that urbanization worsened the problem of air stagnation in Shenzhen. The number of 6-hourly ASCs has increased by 21,700 for the entire Shenzhen, and by 11.4 on average for each grid with a 1 km2 size. A maximum increase of 458 ASCs in a grid was also observed.

Development of an in-home, real-time air pollutant sensor platform and implications for community use.

Air pollution exposure characterization has been shaped by many constraints. These include technologies that lead to insufficient coverage across space and/or time in order to characterize individual or community-level exposures with sufficient accuracy and precision. However, there is now capacity for continuous monitoring of many air pollutants using comparatively inexpensive, real-time sensors. Crucial questions remain regarding whether or not these sensors perform adequately for various potential end uses and whether performance varies over time or across ambient conditions. Performance scrutiny of sensors via lab- and field-testing and calibration across their lifetime is necessary for interpretation of data, and has important implications for end users including cost effectiveness and ease of use. We developed a comparatively lower-cost, portable, in-home air sampling platform and a guiding development and maintenance workflow that achieved our goal of characterizing some key indoor pollutants with high sensitivity and reasonable accuracy. Here we describe the process of selecting, validating, calibrating, and maintaining our platform - the Environmental Multi-pollutant Monitoring Assembly (EMMA) - over the course of our study to-date. We highlight necessary resources and consider implications for communities or researchers interested in developing such platforms, focusing on PM2.5, NO, and NO2 sensors. Our findings emphasize that lower-cost sensors should be deployed with caution, given financial and resource costs that greatly exceed sensor costs, but that selected community objectives could be supported at lesser cost and community-based participatory research strategies could be used for more wide-ranging goals.