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Target blood pressure in diabetes patients with hypertension——What is the accumulated evidence in 2011?

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2011年第8期12卷 611-623页

作者： peter m.NILSSON Department of Clinical Sciences Lund UniversityUniversity Hospital

There is overwhelming evidence that hypertension is an important risk factor for both macrovascular and microvascular complications in patients with diabetes,but the problem remains to identify appropriate goals for preventive therapies.A number of guidelines (the European Society of Cardiology (ESC)/European Association for the Study of Diabetes (EASD) 2007,the Joint National Committee (JNC)-Ⅶ 2003,the American Diabetes Association (ADA) 2011) have for example advocated a blood pressure goal of less than 130/80 mmHg,but this suggestion has been challenged by findings in recent trials and meta-analyses (2011).The European Society of Hypertension (ESH) therefore recommends a systolic blood pressure goal of "well below" 140 *** on evidence from both randomized controlled trials (hypertension optimal treatment (HOT),action in diabetes and vascular disease:preterax and diamicron mR controlled evaluation (ADVANCE),action to control cardiovascular risk in diabetes (ACCORD)) and observational studies (ongoing telmisartan alone and in combination with ramipril global endpoint trial (ONTARGET),international verapamil-trandolapril study (INVEST),treat to new targets (TNT),and the National Diabetes Register (NDR)),it has been shown that the benefit for stroke reduction remains even at lower achieved blood pressure levels,but the risk of coronary events may be uninfluenced or even increased at lower systolic blood pressure *** a recent meta-analysis,it was therefore concluded that the new recommended goal should be 130-135 mmHg systolic blood pressure for most patients with type 2 *** risk factors should also be controlled with a more ambitious strategy applied in the younger patients with shorter diabetes duration,but a more cautious approach in the elderly and frail patients with a number of vascular or non-vascular *** patients from East Asia,such as China,the stroke risk is relatively higher than the risk of coronary *** must al

关键词： Blood pressure Cardiovascular Diabetes Goal Hypertension Treatment

Quantum corrections for Boltzmann equation

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Science China(Physics,mechanics & Astronomy) 2008年第9期51卷 1229-1239页

作者： m. Levy peter Department of Physics New York University

We present the lowest order quantum correction to the semiclassical Boltzmann distribution function,and the equation satisfied by this correction is given. Our equation for the quantum correction is obtained from the conventional quantum Boltzmann equation by explicitly expressing the Planck constant in the gradient approximation,and the quantum Wigner distribution function is expanded in pow-ers of Planck constant,too. The negative quantum correlation in the Wigner dis-tribution function which is just the quantum correction terms is naturally singled out,thus obviating the need for the Husimi’s coarse grain averaging that is usually done to remove the negative quantum part of the Wigner distribution function. We also discuss the classical limit of quantum thermodynamic entropy in the above framework.

关键词： quantum Boltzmann equation Wigner distribution function quantum correction

Testing flexible polymer solar cells in near-space

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National Science Review 2023年第5期10卷 105-106页

作者： peter müller-Buschbaum Department of Physics TUM School of Natural Sciencesand Heinz Maier-Leibnitz-Zentrum(MLZ)Technical University of Munich

Since the big success of the Vanguard1 mission,being the first solar-powered satellite,the use of solar cells in space developed very ***,conventional solar cell technologies for space are based on silicon and GaAs **...

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Fluid and Osmotic Pressure Balance and Volume Stabilization in Cells Dedicated to Professor Karl Stark Pister for his 95th birthday

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Computer modeling in Engineering & Sciences 2021年第12期129卷 1329-1350页

作者： peter m.Pinsky Department of mechanical Engineering Stanford UniversityStanford94305CAUSA

A fundamental problem for cells with their fragile membranes is the control of their *** primordial solution to this problem is the active transport of ions across the cell membrane to modulate the intracellular osmotic *** this work,a theoretical model of the cellular pump-leak mechanism is proposed within the general framework of linear nonequilibrium *** model is expressed with phenomenological equations that describe passive and active ionic transport across cell membranes,supplemented by an equation for the membrane potential that accounts for the electrogenicity of the ionic *** active ionic transport,the model predicts that the intracellular fluid pressure will be balanced by the osmotic pressure and a new pressure component that arises from the active ionic fluxes.A model for the pump-leak mechanism in an idealized human cell is introduced to demonstrate the applicability of the proposed theory.

关键词： Pump-leak mechanism cell volume regulation active ion transport ion pump membrane transport cell mechanics modified Kedem-Katchalsky equations nonequilibrium thermodynamics phenomenological equations

Terrestrial denitrification:challenges and opportunities

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Ecological Processes 2012年第1期1卷 1-11页

作者： peter m Groffman Cary Institute of Ecosystem Studies 2801 Sharon TurnpikeMillbrookNY 12545USA

Denitrification is a process of great environmental importance but is difficult to study in terrestrial *** for quantifying the process are problematic,variability in activity is high,and temporal and spatial scaling challenges are *** methods are problematic for a variety of reasons;they change substrate concentrations,disturb the physical setting of the process,lack sensitivity or are prohibitively costly in time and *** fundamentally,it is very difficult to quantify the dominant end-product(N_(2))of denitrification given its high background concentration in the *** and temporal variation in denitrification is high due to control of the process by multiple factors(oxygen,nitrate,carbon,pH,salinity,temperature etc.)that each vary in time and space.A particular challenge is that small areas(hotspots)and brief periods(hot moments)frequently account for a high percentage of N gas flux *** phenomena are challenging to account for in measurement,modeling and scaling *** need for scaling is driven by the fact that there is a need for information on this microscale process at the ecosystem,landscape and regional scales where there are concerns about nitrogen effects on soil fertility,water quality and air *** this review,I outline the key challenges involved with denitrification and then describe specific opportunities for making progress on these challenges including advances in measurement methods,new conceptual approaches for addressing hotspot and hot moment dynamics,and new remote sensing and geographic information system–based scaling *** of these opportunities suggests that we are poised to make great improvements in our understanding of terrestrial *** improvements will increase our basic science understanding of a complex biogeochemical process and our ability to manage widespread nitrogen pollution problems.

关键词： scaling process landscape

Simulation and calibration of granules using the discrete element method

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Particuology 2014年第1期12卷 40-43页

作者： peter müller Jürgen Tomas Institute of Process Engineering Mechanical Process EngineeringOtto-von-Guericke University MagdeburgUniversitätsplatz 239106 MagdeburgGermany

The discrete element method （DEm）, developed by Cundall and 5track to solve geomecnamcai problems, is used to simulate the mechanical behavior of granules. According to the DEm, an individ ual granule can be modeled as a realistic mechanical system consisting of primary particles bonded by interaction forces. Cranulometric properties of the model material, zeolite 4A, have been measured to determine their macro properties. To investigate the compression behavior, a compression test was performed using a strength tester on single granules between two pistons. A modeled granule consisting of more than 22,000 primary particles was generated. The micro properties of the modeled granule have been precisely set to allow its macro properties to be equivalent to the macro properties of zeolite 4A granules. To calibrate the mechanical properties, diametrical compression was simulated using two rigid walls stressed at a constant stressing velocity, The force-displacement curve of the modeled granule at compression has been calibrated by the experimental curve of zeolite 4A.

关键词： Discrete element method material behavior Granulation

A Transmission Electron microscopy Study of Plate martensite Formation in High-carbon Low Alloy Steels

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Journal of materials Science & Technology 2013年第4期29卷 373-379页

作者： Albin Stormvinter peter Hedstrm Annika Borgenstam Department of materials Science and Engineering School of Industrial Engineering and ManagementKTH Royal Institute of TechnologySE-100 44 StockholmSweden

The martensitic microstructures in two high-carbon low alloy steels have been investigated by classical and automated crystallographic analysis under a transmission electron microscope. It is found that the martensitic substructure changes from consisting mostly of transformation twins for 1.20 mass% carbon （C） steel to both transformation twins and planar defects on {101}m for 1.67 mass% C steel. In the 1.67 mass% C steel it is further found that small martensite units have a rather homogeneous substructure, while large martensite units are more inhomogeneous. In addition, the martensite units in both steels are frequently found to be of zigzag patterns and have distinct crystallographic relationships with neighboring martensite units, e.g. kink or wedge couplings. Based on the present findings the development of martensite in high-carbon low alloy steels is discussed and a schematic of the martensite formation is presented. moreover, whether the schematic view can be applied to plate martensite formation in general, is discussed.

关键词： Transmission electron microscopy High-carbon low alloy steel Plate martensite

On the experimental characterization of the fluid volume influence on the friction between rough surfaces

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Friction 2023年第7期11卷 1334-1348页

作者： Lukas STAHL michael mÜLLer Georg-peter OSTermEYer Institute of Dynamics and Vibrations Technische Universität BraunschweigBraunschweig 37106Germany

The load-bearing behaviour of lubricated contacts depends primarily on the normal force,the relative velocity,and the ***,with the aid of the Stribeck curve,it is usually well possible to characterize whether hydrodynamics,mixed friction,or boundary friction is more likely to be *** fact that the load regime can also depend on the fluid quantity is obvious,but has hardly been systematically investigated so *** for contacts with microscopic roughness,the defined application of a very small amount of fluid is a very challenging *** this paper,a very fundamental study shows how a pin-on-disc tribometer can be used to achieve the transition from dry friction via mixed friction to predominant hydrodynamics by the amount of supplied *** experiments are carried out on samples filed with different *** addition,the simultaneous influence of partial filling and normal force as well as relative velocity is also *** good reproducibility has been practically reached over the entire range of the *** the quantities for the coefficient of friction(COF),it was concluded that close to full filling,a reduction of the fluid quantity has a similar effect on the COF as the reduction of the *** property goes along with the common theory of starved lubricated *** behaviour was not observed to the same extent for the normal *** the vicinity of smaller fluid quantities,the COF increases very rapidly with further reduction in fluid quantity,far more disproportionately than that with reduction in *** a deeper understanding of this problem,various practical issues such as idling or the run-up process in bearings can also be studied in a more focused manner.

关键词： starved lubrication Stribeck curve pin-on-disc tribometer fluid supply experimental studies

Towards implementation of alloy-specific thermo-fluid modelling for laser powder-bed fusion of mg alloys

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Journal of magnesium and Alloys 2024年第6期12卷 2327-2344页

作者： mohammad Hoseini-Athar mikael ersson peter Hedström Department of material Science and Engineering KTH Royal Institute of TechnologyStockholmSE-10044 Sweden

multi-physics thermo-fluid modeling has been extensively used as an approach to understand melt pool dynamics and defect formation as well as optimizing the process-related parameters of laser powder-bed fusion(L-PBF).However,its capabilities for being implemented as a reliable tool for material design,where minor changes in material-related parameters must be accurately captured,is still in *** the present research,first,a thermo-fluid computational fluid dynamics(CFD)model is developed and validated against experimental *** the predicted material properties of the pure mg and commercial ZK60 and WE43 mg alloys,parametric studies are done attempting to elucidate how the difference in some of the material properties,i.e.,saturated vapor pressure,viscosity,and solidification range,can influence the melt pool *** is found that a higher saturated vapor pressure,associated with the ZK60 alloy,leads to a deeper unstable keyhole,increasing the keyhole-induced porosity and evaporation mass *** viscosity and wider solidification range can increase the non-uniformity of temperature and velocity distribution on the keyhole walls,resulting in increased keyhole instability and formation of ***,the WE43 alloy showed the best behavior in terms of defect formation and evaporation mass loss,providing theoretical support to the extensive use of this alloy in *** summary,this study suggests an approach to investigate the effect of materials-related parameters on L-PBF melting and solidification,which can be extremely helpful for future design of new alloys suitable for L-PBF.

关键词： mg alloys Laser powder-bed fusion(L-PBF) melt pool dynamics Computational fluid dynamics Fluid flow