Optimal measurement locations for diagnosis of aortic abnormalities in a lumped-parameter model of the systemic circulation using sensitivity analysis

The basic theme of this work is to identify the optimal measurement locations for pres- sure and flow in the systemic circulation to detect aortic stenoses and aneurysms in early stages of a disease. For this purpose, a linear elastic lumped parameter model of the fluid dynamical simulator, major arterial cardiovascular simulator （MACSim）, is considered and global sensitivity analysis is applied to identify the better measurement locations for pressure and flow in the systemic circulation. The obtained results of sensitivity analysis provide insight that enable the experimentalists to optimize their experimental setups for detecting aortic stenoses and aneurysms using parameter estimation process. From the results, it is observed that the stenosis in the thoracic aorta can be identified from both pressure and flow at the location itself, nearby nodes, aorta ascendens, arcus aorta, arteria subclavia and arteria axillaris. On the other hand, the preferable measurement locations for abdominal aneurysms are locations themselves, nearby nodes and left/right leg of the body.

Effects of 3，4－Dihydroxyacetophenone （3，4－DHAP） on Hypoxic Pulmonary and Systemic Vascular Response in Dogs

The effects of 3,4-DHAP on hypoxic pulmonary and systemic vascular responses were studied in anaesthetized dogs. The percentage change in pulmonary vascular resistance(△PVR%)and that in systemic vascular resistance(△SVR%)induced by 5 min hypoxia decreased significantly.3,4-DHAP in doses of 1 mg/kg,3mg/kg,and 10 mg/kg i.v caused a decrease in b PVR% from the control value of 47.27±22.27% to 24.62±21.76%,18.15±18.73%,and 24.10±19.76% respectively, and a decrease in △SVR% from the control value of 12.91±7.39% to -0.34±12.7%,-2.11±12.76%,and -2.37±15.52% respectively.The results showed that 3,4-DHAP could decrease the hypoxic responses of pulmonary and systemic blood vessels.But it did not change △PVR% or △SVR% in dose of 30mg/kg,neither did it influence the heart rate,cardiac output or cerebral blood flow during hypoxia in all the doses used.

Numerical Modellings of Properties of the Summer Quasi-Stationary Circulation Systems and Their Monthly Variations

An ocean-atmosphere and land-air coupled numerical model system is used to study the basic properties and the monthly time variations of the summer quasi-stationary circulation systems. It is found that either at the upper or at the lower levels of the atmosphere, the circulation patterns have a two-wave structure in the zonal direction at the mid and high latitudes of the Northern Hemisphere. Such a structure of circulation is totally matchable to that of the land-sea distribution there. It is proved, hence, that the land-sea distributive pattern is the fundamental cause for the summer quasi-stationary circulation pattern. The topography in the globe is the secondary factor for circulation systems. The circulation centres of the quasi-stationary systems are always located in certain areas due to the thermodynamic contrast between land and sea.From the time evolutions of the circulation systems it is seen that the change is larger at the beginning period of the time integration, it is because of using the zonally averaged mean fields as the initial values of the model. As long as the basic simulated pattern of circulations reaches the state similar to that of the real climatic fields resulting from the coeffects of the land-sea distribution and the topography, the circulation systems modelled will change slowly and tend to a quasi-stationary state. Therefore, the time integration does not need to last for a very long time, if the purpose of numerical modellings is to test sensitivities of some factors influencing the climate, 20 model days may be enough for sensitive experiments.

Exercise training mode effects on myokine expression in healthy adults:A systematic review with meta-analysis

Background:The benefits of exercise are well known;however,many of the underlying molecular mechanisms are not fully understood.Skeletal muscle secretes myokines,which mediate muscleorgan crosstalk.Myokines regulate satellite-cell proliferation and migration,inflammatory cascade,insulin secretion,angiogenesis,fatty oxidation,and cancer suppression.To date,the effects of different exercise modes(namely,aerobic and resistance exercise)on myokine response remain to be elucidated.This is crucial considering the clinical implementation of exercise to enhance general health and wellbeing and as a medical treatment.Methods:A systematic search was undertaken in PubMed,MEDLINE,CINAHL,Embase,SPORTDiscus,andWeb of Science in April 2023.Eligible studies examining the effects of a single bout of exercise on interleukin15(IL-15),irisin,secreted protein acidic and rich in cysteine(SPARC),oncostatinM(OSM),and decorin were included.A random-effects meta-analysis was also undertaken to quantify the magnitude of change.Results:Sixty-two studies were included(n=1193).Overall,exercise appeared to induce small to large increases in myokine expression,with effects observed immediately after to 60 min post-exercise,although these were mostly not statistically significant.Both aerobic and resistance exercise resulted in changes in myokine levels,without any significant difference between training modes,and with the magnitude of change differing across myokines.Myokine levels returned to baseline levels within 180 min to 24 h post-exercise.However,owing to potential sources of heterogeneity,most changes were not statistically significant,indicating that precise conclusions cannot be drawn.Conclusion:Knowledge is limited but expanding with respect to the impact of overall and specific effects of exercise on myokine expression at different time points in the systemic circulation.Further research is required to investigate the effects of different exercise modes at multiple time points on myokine response.

Extrahepatic complications to cirrhosis and portal hypertension: Haemodynamic and homeostatic aspects

In addition to complications relating to the liver, patients with cirrhosis and portal hypertension develop extrahepatic functional disturbances of multiple organ systems. This can be considered a multiple organ failure that involves the heart, lungs, kidneys, the immune systems, and other organ systems. Progressive fibrosis of the liver and subsequent metabolic impairment leads to a systemic and splanchnic arteriolar vasodilatation. This affects both the haemodynamic and functional homeostasis of many organs and largely determines the course of the disease. With the progression of the disease, the circulation becomes hyperdynamic with cardiac, pulmonary as well as renal consequences for dysfunction and reduced survival. Infections and a changed cardiac function known as cirrhotic cardiomyopathy may be involved in further aggravation of other complications such as renal failure precipitatingthe hepatorenal syndrome.Patients with end-stage liver disease and related complications as for example the hepatopulmonary syndrome can only radically be treated by liver transplantation.As a bridge to this treatment,knowledge on the mechanisms of the pathophysiology of complications is essential for the choice of vasoactive drugs,antibiotics,drugs with specific effects on fibrogenesis and inflammation,and drugs that target specific receptors.

Mesenchymal stromal cells' role in tumor microenvironment:involvement of signaling pathways

Mesenchymal stromal cells(MSCs) are adult multipotent stem cells residing as pericytes in various tissues and organs where they can differentiate into specialized cells to replace dying cells and damaged tissues. These cells are commonly found at injury sites and in tumors that are known to behave like "wounds that do not heal." In this article, we discuss the mechanisms of MSCs in migrating, homing, and repairing injured tissues. We also review a number of reports showing that tumor microenvironment triggers plasticity mechanisms in MSCs to induce malignant neoplastic tissue formation, maintenance, and chemoresistance, as well as tumor growth. The antitumor properties and therapeutic potential of MSCs are also discussed.

MEDIUM-RANGE OSCILLATION AND TELECONNECTION OF THE ATMOSPHERIC CIRCULATION SYSTEMS OVER THE NORTHWEST PACIFIC AND SOUTH INDIAN OCEANS

This paper aims to demonstrate some characteristics of the 20-50 day oscillations of certain circulation systems in low latitudes during the northern summer seasons.The teleconnection between the variations of the Mascarene high and the Northwest Pacific high and its physical mechanism are studied.How the Mas- carene high plays an important role in the interaction between the atmospheric circulations of both hemispheres is discussed.

Diagnosis of the Secondary Circulation of Tropical Storm Bilis(2006) and the Effects of Convective Systems on Its Track

We diagnose characteristics of the quasi-balanced flow and secondary circulation（SC） of tropical storm Bilis（2006） using the potential vorticity（PV）-ω inversion method.We further analyze how secondary steering flows associated with mesoscale convective systems affected the track of tropical storm Bilis after it made landfall.The quasi-balanced asymmetric and axisymmetric circulation structures of tropical storm Bilis are represented well by the PV-w inversion.The magnitude of the nonlinear quasi-balanced vertical velocity is approximately 75%of the magnitude simulated using the Weather Research and Forecasting（WRF） model.The SC of Bilis（2006） contained two strong regions of ascending motion,both of which were located in the southwest quadrant of the storm.The first（150-200 km southwest of the storm center） corresponded to the eyewall region,while the second（approximately 400 km southwest of the storm center） corresponded to latent heat release associated with strong precipitation in major spiral rainbands.The SC was very weak in the northeast quadrant（the upshear direction）.Dynamical processes related to the environmental vertical wind shear produced an SC that partially offset the destructive effects of the environmental vertical wind shear（by 20%-25%）.This SC consisted of upward motion in the southwest quadrant and subsidence in the northeast quadrant,with airflow oriented from southwest to northeast at high altitudes and from northeast to southwest at lower levels.The inverted secondary zonal and meridional steering flows associated with continuous asymmetric mesoscale convective systems were about-2.14 and-0.7 m s^（-1）,respectively.These steering flows contributed substantially to the zonal（66.15%） and meridional（33.98%） motion of the storm at 0000 UTC15 July 2006.The secondary steering flow had a significant influence on changing the track of Bilis from southward to northward.The direction of the large-scale meridional steering flow（3.02 m s^（-1）） was opposite to the actual meridional motion（-2.06 m s^（-1））.

The Persistent Heavy Rainfall over Southern China in June 2010:Evolution of Synoptic Systems and the Effects of the Tibetan Plateau Heating

This study investigates influencing weather systems for and the effect of Tibetan Plateau （TP）’s surface heating on the heavy rainfall over southern China in June 2010, focusing on the four persistent heavy rainfall events during 14-24 June 2010. The ma jor weather systems include the South Asian high, midlatitude trough and ridge, western Pacific subtropical high in the middle troposphere, and shear lines and eastward-moving vortices in the lower troposphere. An ensemble of convection-permitting simulations （CTL） is carried out with the WRF model for these rainfall events, which successfully reproduce the observed evolution of precipitation and weather systems. Another ensemble of simulations （SEN） with the surface albedo over the TP and its southern slope changed artificially to one, i.e., the surface does not absorb any solar heating, otherwise it is identical to CTL, is also performed. Comparison between CTL and SEN suggests that the surface sensible heating of TP in CTL significantly affects the temperature distributions over the plateau and its surroundings, and the thermal wind adjustment consequently changes atmospheric circulations and properties of the synoptic systems, leading to intensified precipitation over southern China. Specifically, at 200 hPa, anticyclonic and cyclonic anomalies form over the western and eastern plateau, respectively, which enhances the southward cold air intrusion along the eastern TP and the divergence over southern China;at 500 hPa, the ridge over the northern plateau and the trough over eastern China are strengthened, the southwesterly flows along the northwestern side of the subtropical high are intensified, and the positive vorticity propagation from the plateau to its downstream is also enhanced significantly;at 850 hPa, the low-pressure vortices strongly develop and move eastward while the southwesterly low-level jet over southern China strengthens in CTL, leading to increased water vapor convergence and upward motion over the precipitation region.

Water vapour multi-vortex structure under the interactions of typhoons and mid-low latitude systems during extreme precipitation in North China

With diverse atmospheric circulation and complex mechanisms,typhoon remote rainstorms(TRR)are closely related to a variety of mid-low latitude systems.The anomalous signatures in such processes can improve forecasting heavy rainfall associated with typhoons and fill the gaps in current physical conceptual models of TRR.Using the optimal typhoon path dataset,ground observation data,and the National Centres for Environmental Prediction(NCEP)reanalysis dataset,the impact of anomalous water vapour transport on excessive rainfall in North China is investigated.The vector empirical orthogonal function(VEOF)analysis is applied to typhoon precipitation events from 1970 to 2021,and three major modes are extracted to reflect the anomalous water vapour transport for typhoon precipitation.Mode 1 reflects a moisture circulation pattern in North China due to the coexistence of typhoons and remote and direct precipitation,with the highest probability of heavy precipitation.The differences in remote precipitation areas and intensities are attributed to the location of typhoons in the western North Pacific and the shifting of the subtropical high ridge.To characterise the water vapour transport circulation of TRR in North China,we proposed the‘multivortex’idea.The transmission of the multi-vortex ensures a continuous supply of TRR water vapour,and the enhancement of the multi-vortex is significantly linked to the enhancement of remote precipitation.Three extreme northern rainstorms,75·8 Henan,7·21 Beijing,and 7·20 Zhengzhou rainstorms,have anomalous multi-vortex water vapour convergence,similar to Mode 1.The mechanism of water vapour driven by multi-vortex in the three severe rainstorm events is more extreme than in usual TRR events in North China.The stronger Indian low vortex and relatively southerly subtropical highs can intensify the southwest branch of the double water vapour transport branch,whereas the strengthening of typhoons in the western North Pacific facilitates water vapour transport through the channel on the southwestern side of the subtropical highs and then transports it to key rainstorm areas,promoting TRR development.Therefore,the combination of subtropical highs,typhoons,and the anomalous multi-vortex structure may help in the establishment of key indicators of extreme precipitation in North China.