| 1. |
- Zhang, Yanqing, et al.
(författare)
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HflX is a ribosome-splitting factor rescuing stalled ribosomes under stress conditions
- 2015
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Ingår i: Nature Structural & Molecular Biology. - : Springer Science and Business Media LLC. - 1545-9993 .- 1545-9985. ; 22:11, s. 906-913
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Tidskriftsartikel (refereegranskat)abstract
- Adverse cellular conditions often lead to nonproductive translational stalling and arrest of ribosomes on mRNAs. Here, we used fast kinetics and cryo-EM to characterize Escherichia coil HflX, a GTPase with unknown function. Our data reveal that HflX is a heat shock-induced ribosome-splitting factor capable of dissociating vacant as well as mRNA-associated ribosomes with deacylated tRNA in the peptidyl site. Structural data demonstrate that the N-terminal effector domain of HflX binds to the peptidyl transferase center in a strikingly similar manner as that of the class I release factors and induces dramatic conformational changes in central intersubunit bridges, thus promoting subunit dissociation. Accordingly, loss of HflX results in an increase in stalled ribosomes upon heat shock, These results suggest a primary role of HflX in rescuing translationally arrested ribosomes under stress conditions.
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| 2. |
- Shen, Xiaojing, et al.
(författare)
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Spatial distribution and occurrence probability of regional new particle formation events in eastern China
- 2018
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Ingår i: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 18:2, s. 587-599
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Tidskriftsartikel (refereegranskat)abstract
- In this work, the spatial extent of new particle formation (NPF) events and the relative probability of observing particles originating from different spatial origins around three rural sites in eastern China were investigated using the NanoMap method, using particle number size distribution (PNSD) data and air mass back trajectories. The length of the datasets used were 7, 1.5, and 3 years at rural sites Shangdianzi (SDZ) in the North China Plain (NCP), Mt. Tai (TS) in central eastern China, and Lin'an (LAN) in the Yangtze River Delta region in eastern China, respectively. Regional NPF events were observed to occur with the horizontal extent larger than 500 km at SDZ and TS, favoured by the fast transport of northwesterly air masses. At LAN, however, the spatial footprint of NPF events was mostly observed around the site within 100-200 km. Difference in the horizontal spatial distribution of new particle source areas at different sites was connected to typical meteorological conditions at the sites. Consecutive large-scale regional NPF events were observed at SDZ and TS simultaneously and were associated with a high surface pressure system dominating over this area. Simultaneous NPF events at SDZ and LAN were seldom observed. At SDZ the polluted air masses arriving over the NCP were associated with higher particle growth rate (GR) and new particle formation rate (J ) than air masses from Inner Mongolia (IM). At TS the same phenomenon was observed for J , but GR was somewhat lower in air masses arriving over the NCP compared to those arriving from IM. The capability of NanoMap to capture the NPF occurrence probability depends on the length of the dataset of PNSD measurement but also on topography around the measurement site and typical air mass advection speed during NPF events. Thus the long-term measurements of PNSD in the planetary boundary layer are necessary in the further study of spatial extent and the probability of NPF events. The spatial extent, relative probability of occurrence, and typical evolution of PNSD during NPF events presented in this study provide valuable information to further understand the climate and air quality effects of new particle formation.
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| 3. |
- Yu, Hua, et al.
(författare)
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Organic coating on sulfate and soot particles during late summer in the Svalbard Archipelago
- 2019
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Ingår i: Atmospheric Chemistry And Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 19:15, s. 10433-10446
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Tidskriftsartikel (refereegranskat)abstract
- Interaction of anthropogenic particles with radiation and clouds plays an important role in Arctic climate change. The mixing state of aerosols is a key parameter to influence aerosol radiation and aerosol-cloud interactions. However, little is known of this parameter in the Arctic, preventing an accurate representation of this information in global models. Here we used transmission electron microscopy with energy-dispersive X-ray spectrometry, scanning electron microscopy, nanoscale secondary ion mass spectrometry, and atomic forces microscopy to determine the size and mixing state of individual sulfate and carbonaceous particles at 100 nm to 2 mu m collected in the Svalbard Archipelago in summer. We found that 74% by number of non-sea-salt sulfate particles were coated with organic matter (OM); 20% of sulfate particles also had soot inclusions which only appeared in the OM coating. The OM coating is estimated to contribute 63% of the particle volume on average. To understand how OM coating influences optical properties of sulfate particles, a Mie core-shell model was applied to calculate optical properties of individual sulfate particles. Our result shows that the absorption cross section of individual OM-coated particles significantly increased when assuming the OM coating as light-absorbing brown carbon. Microscopic observations here suggest that OM modulates the mixing structure of fine Arctic sulfate particles, which may determine their hygroscopicity and optical properties.
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| 4. |
- Kang, Yu, et al.
(författare)
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Tolerability and effectiveness of beta-blockers in patients with cardiac amyloidosis: A systematic review and meta-analysis
- 2024
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Ingår i: International Journal of Cardiology. - 0167-5273 .- 1874-1754. ; 402
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Forskningsöversikt (refereegranskat)abstract
- Objective: This systematic review aimed to assess the tolerability of patients with cardiac amyloidosis (CA) to beta-blockers (BBs) and evaluate its association with adverse outcomes. Methods: We performed a comprehensive search from January 1, 2000 to October 20, 2023. Studies examining BB use and tolerance or the relationship between BB use and outcomes in patients with CA were included. Pooled adjusted hazard ratios (aHRs) for all-cause mortality were calculated using random- and fixed-effects models. Results: Eight observational studies involving 4002 patients with CA (87.5% with transthyretin CA [ATTR-CA] and 12.5% with immunoglobulin light chain CA [AL-CA]) were assessed. BBs were used by 52.5% of the patients. However, 26.3% of the patients discontinued BBs because of hypotension, bradycardia, or fatigue. Regarding the association between BB use and all-cause death, four studies were identified that included 2874 patients with ATTR-CA and 16 patients with AL-CA. The meta-analysis revealed no apparent relationship between BB use and all-cause mortality (pooled aHR = 0.78, 95% confidence interval (CI) = 0.40–1.51). Two studies on patients with ATTR-CA found no impact of BB use on all-cause mortality in the subgroup with left ventricular ejection fraction (LVEF) > 40%, but conflicting results exist for those with LVEF ≤40% (pooled aHR = 0.78, 95% CI = 0.40–1.54). Conclusion: The limited number of observational studies that predominantly enrolled patients with ATTR-CA showed that BBs were used in almost half of the patients with CA, with varying tolerability. However, no significant association was observed between BB use and all-cause mortality.
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| 5. |
- Berezovskaya, Yulia, et al.
(författare)
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A hybrid fault detection and diagnosis method in server rooms’ cooling systems
- 2019
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Ingår i: 2019 IEEE 17th International Conference on Industrial Informatics (INDIN). - : IEEE. ; , s. 1405-1410
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Data centers as all complex systems are prone to faults, and cost of them can be very high. This paper is focused on detecting the faults in the cooling systems, in particular on local fans level. In the paper, a hybrid approach is proposed. In the approach a model is used as substitute of the real system to generate dataset containing records of both normal and fault cases. On the generated data, machine learning algorithm or ensemble of algorithms are selected and trained to detect the faults. To demonstrate the approach, the rack model of real data center is created, and reliability of the model is shown. Using the model, the dataset with normal as well as abnormal records of data is generated. To detect faults of local fans, simple classifiers are built for all pairs: a local fan – a processor unit. Classifiers are trained on one part of generated data (training data), and then their accuracy is estimated on another part of generated data (test data). A real-time fault detection system is built based on the classifiers. The rack model is used as the substitute of the real plant to check operability of the system.
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| 6. |
- Berezovskaya, Yulia, et al.
(författare)
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Improvement of Energy Efficiency in Data Centers via Flexible Humidity Control
- 2016
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Ingår i: IECON Proceedings (Industrial Electronics Conference). - Piscataway, NJ : IEEE Computer Society. - 9781509034741 ; , s. 5585-5590
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Konferensbidrag (refereegranskat)abstract
- Abstract- The main goal of climate control systems in data centres is to keep the temperature and humidity in a suitable level for computational devices. Therefore, cooling and humidification systems are essential parts of every Building Automation System (BAS), which is utilized in server rooms. Although the current climate control systems ensure appropriate thermal conditions to computational nodes such as servers, they waste substantial amount of energy. The main cause of this inefficiency is that the current climate control systems, which are responsible for thermal management of the data centres, follow rigid control strategies that maintain constant thermal conditions irrespective of climate changes caused by various computational loads in the plant. To address this issue, in our previous works we proposed a method of optimizing energy consumption in data centre cooling systems while maintaining an acceptable level of thermal comfort for CPUs in the server room. In this paper, we present the enhancement of our previous method by incorporating humidity control into it. The enhanced method consists of a thermal model of server room, and a simulation tool to find an energy efficient control strategy for the climate control system in different situations by comparing different control strategies. The effectiveness of the proposed method has been investigated via simulation and the result, which shows 41.5% reduction in total energy consumption is presented.
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| 7. |
- Berezovskaya, Yulia, et al.
(författare)
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Smart Distribution of IT Load in Energy Efficient Data Centers with Focus on Cooling Systems
- 2018
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Ingår i: Proceedings. - : IEEE. ; , s. 4907-4912
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Konferensbidrag (refereegranskat)abstract
- Cooling system is the second most energy-consuming part of a modern data center; herewith it often consumes energy inefficiently. Therefore, any possibility allowing to reduce energy consumption of cooling systems should be studied and put into practice if successful. In this paper, the idea about impact of IT load distribution between servers on energy consumption of data center cooling system is proposed. The idea is in distribution of total IT load between servers according to the location of the servers inside racks. To test idea, the model simulating the thermal behaviour and energy consumption of a real data center located in Northern Sweden is developed. Comparing the data obtained from the real plant and the data generated at the simulation shows the reliability of the model. Two strategies of IT load distribution between servers are considered, and their impact on energy consumption of cooling system is demonstrated.
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| 8. |
- Feng, Y. Z., et al.
(författare)
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Patient-level comparison of heart failure patients in clinical phenotype and prognosis from China and Sweden
- 2022
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Ingår i: Bmc Cardiovascular Disorders. - : Springer Science and Business Media LLC. - 1471-2261. ; 22:1
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Tidskriftsartikel (refereegranskat)abstract
- Background Clinical phenotype and prognosis of heart failure (HF) may be variable among different racial populations. Therefore, a patient-level comparison of hospitalized HF patients in two university hospitals from China and Sweden was performed. Methods and results This study was a pooled data analysis of the patients prospectively enrolled in two single-center studies in China (n = 949) and Sweden (n = 1639) from 2011 to 2015. Clinical characteristics and 6-month all-cause mortality were collected. Higher systolic blood pressure (126.1 +/- 20.3 vs. 114.2 +/- 15.4 mmHg, p < 0.001) and NT-proBNP level (4540 vs. 3251 pg/mL, p = 0.013) were found in the Swedish cohort, also more patients with ischemic heart disease (32.0% vs. 19.2%), hypertension (64.2% vs. 36.8%), valvular heart disease (40.9% vs.31.6%) and atrial fibrillation (55.3% vs. 39.6%) (all p < 0.001). The use of ACEIs/ARBs (48.8% vs. 80.8%) or beta-blockers (58.8% vs. 86.5%) (both p < 0.001) was lower in Chinese cohort. Given younger age in Chinese cohort (61.6 vs. 76.4 years, p < 0.001), age-stratified analyses were conducted, as there were similar patient numbers in 50-74 years in Chinese (n = 550) and Swedish (n = 554) cohorts, therefore baseline characteristics and prognosis were further compared. The age- and sex-adjusted outcome (HR 0.80 [95% CI 0.55-1.19], p = 0.273) was comparable between the two populations. The NT-proBNP and eGFR independently predicted 6-month mortality in both Chinese (HR [95% CI] 1.006 [1.003-1.008], 0.986 [0.976-0.999]) and Swedish cohort (1.003 [1.000-1.007], 0.988 [0.976-0.999]). Conclusions Patient-level comparison of real-world HF populations from China and Sweden demonstrated different clinical phenotypes and therapy but similar prognosis and their predictors.
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| 9. |
- Han, Siyuan, et al.
(författare)
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Side-chain engineering of PEDOT derivatives as dopant-free hole-transporting materials for efficient and stable n-i-p structured perovskite solar cells
- 2020
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Ingår i: Journal of Materials Chemistry C. - : Royal Society of Chemistry (RSC). - 2050-7526 .- 2050-7534. ; 8:27, s. 9236-9242
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Tidskriftsartikel (refereegranskat)abstract
- Low-cost poly(3,4-ethylenedioxythiophene) (PEDOT) and its derivatives have been widely used as hole-transporting materials (HTMs) in p-i-n perovskite solar cells (PSCs). However, reports on the use of PEDOT-based HTMs in regular PSCs have been rather limited up till now due to the low solubility of PEDOT in organic solvents. In this work, we report three PEDOT derivatives, namely, PEDOT-C6 (P6), PEDOT-C10 (P10), and PEDOT-C14 (P14), with a simple synthetic process by tailoring the length of the alkyl side-chains, and apply them as dopant-free HTMs in mesoscopic n-i-p structured PSCs. It is revealed that the alkyl side-chain length has a significant impact on the film morphology, hole transport capability, and thus the overall solar cell performance. The devices with P10 afford a champion PCE of 16.2% at one sun illumination (100 mW cm(-2), AM 1.5G), which is significantly higher compared to those based on P6 (12.1%) and P14 (14.8%) under identical conditions. This has been the highest PCE reported so far for dopant-free PEDOT-based HTMs in conventional PSCs. The greatly enhanced photovoltaic performance observed for the P10-based devices is mainly attributed to the superior film formation property and hole transport capability of P10. Furthermore, the devices utilizing P10 also show excellent ambient stability, retaining 75% of their initial performance at a relative humidity (RH) of 80% after 120 h due to the high moisture resistivity of the HTM. The present work provides a new avenue for further developing low-cost, efficient, and stable HTMs in PSCs in the future.
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| 10. |
- Mousavi, Arash, et al.
(författare)
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Cyber-physical Design of Data Centers Cooling Systems Automation
- 2015
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Ingår i: IEEE TrustCom-BigDataSE-ISPA 2015. - Piscataway, NJ : IEEE Communications Society. - 9781467379519 ; , s. 254-260
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Konferensbidrag (refereegranskat)abstract
- Modern data centers in many aspects are akin to industrial plants that generate a lot of heat by consuming substantial amount of energy and require powerful cooling and ventilation. Cooling system contributes with 30 to 50% of the total energy consumption of data centers. An effective way to address energy efficiency in such cooling systems is to apply advanced automation solutions, similar to that of industrial and building automation systems. However, existing automation solutions are not flexible enough to meet requirements of cooling systems in modern data centres. This paper is an endeavour to utilize distributed adaptive automation architecture in order to improve energy efficiency of cooling. The proposed automation algorithms are validated in a simulation environment which models the thermal behaviour of a server room and helps to find the most energy efficient control strategy for controlling thecooling devices. This paper describes the simulation tool comprising of thermal behaviour modelling in MATLAB/SIMULINK connected in closed-loop with the distributed control environment of IEC 61499 standard. Simulation of a typical server room under certain constraints using the proposed tool is described and the results are presented. The results demonstrate the potential of improving higher energy efficiency, flexibility and better decision-making ability for controlling the cooling systems.
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