Prediction of Coefficient of Restitution for Impact Elastoplastic Spheres Considering Finite Plate Thickness

Collisions between objects are a relatively common phenomenon in nature.Analyses of collision processes can greatly contribute to solving problems such as impact-rub faults and particle impacts.The coefficient of restitution is a critical parameter in the analysis of collision processes.Many experiments have shown that the coefficient of restitution is closely related to the plate thickness,and the smaller the plate thickness,the more inaccurate the coefficient of restitution predicted by the existing model,which seriously affects the process of collision analysis.To remedy this shortcoming,this paper proposes a plate thickness influence factor with the ratio of sphere diameter to plate thickness as the variable.The plate thickness influence factor can optimize the coefficient of restitution model to effectively predict the coefficient of restitution of impacting elastoplastic spheres with finite plate thickness.Finally,the validity of the new model is verified using a large amount of experimental data.

Functional and morphological changes of the gut barrier during the restitution process after hemorrhagic shock

AIM： To investigate the functional, morphological changes of the gut barrier during the restitution process after hemorrhagic shock, and the regional differences of the large intestine and small intestine in response to ischemia/ reperfusion injury. METHODS： Forty-seven Sprague-Dawley rats with body weight of 250-300 g were divided into two groups： control group （sham shock n = 5） and experimental group （n = 42）. Experimental group was further divided into six groups （n = 7 each） according to different time points after the hemorrhagic shock, including 0^th group, 1^st group, 3^rd group, 6th h group, 12^th group and 24^th group. All the rats were gavaged with 2 mL of suspension of lactulose （L） （100 mg/2 mL） and mannitol （M） （50 mg/each） at the beginning and then an experimental rat model of hemorrhagic shock was set up. The specimens from jejunum, ileum and colon tissues and the blood samples from the portal vein were taken at 0, 1, 3, 6, 12 and 24 h after shock resuscitation, respectively. The morphological changes of the intestinal mucosa, including the histology of intestinal mucosa, the thickness of mucosa, the height of villi, the index of mucosal damage and the numbers of goblet cells, were determined by light microscope and/or electron microscope. The concentrations of the bacterial endotoxin lipopolysaccharides （LPS） from the portal vein blood, which reflected the gut barrier function, were examined by using Limulus test. At the same time point, to evaluate intestinal permeability, all urine was collected and the concentrations of the metabolically inactive markers such as L and M in urine were measured by using GC-9A gas chromatographic instrument.RESULTS： After the hemorrhagic shock, the mucosal epithelial injury was obvious in small intestine even at the 0th h, and it became more serious at the 1^stand the 3^rd h. The tissue restitution was also found after 3 h, though the injury was still serious. Most of the injured mucosal restitution was established after 6 h and completed in 24 h. Two distinct models of cell deathapoptosis and necrosis-were involved in the destruction of rat intestinal epithelial cells. The number of goblet cells on intestinal mucosa was reduced significantly from 0 to 24 h （the number from 243±13 to 157±9 for ileum, 310±19 to 248±18 for colon; r= -0.910 and -0.437 respectively, all P〈0.001）, which was the same with the large intestine, but the grade of injury was lighter with the values of mucosal damage index in 3 h for jejunum, ileum, and colon being 2.8, 2.6, 1.2, respectively. The mucosal thickness and the height of villi in jejunum and ileum diminished in 1 h （the average height decreased from 309±24 to 204±23 pm and 271±31 to 231±28 pm, r = -0.758 and -0.659, all P〈0.001, the thickness from 547±23 to 418±28μm and 483±45 to 364±35μm, r= -0.898 and -0.829, all P〈0.001）, but there was no statistical difference in the colon （F= 0.296, P = 0.934）. Compared with control group, the urine L/M ratio and the blood LPS concentration in the experimental groups raised significantly, reaching the peak in 3-6 h （L/M： control vs 3 h vs6 h was 0.029±0.09 vs 0.063±0.012 vs 0.078±0.021, r = -0.786, P〈0.001; LPS： control vs3 h vs6 h was 0.09±0.021 vs 0.063±0.012 vs0.25±0.023, r=- -0.623, P〈0.001）, and it kept increasing in 24 h. CONCLUSION： The gut barrier of the rats was seriously damaged at the early phase of ischemic reperfusion injury after hemorrhagic shock, which included the injury and atrophy in intestinal mucosa and the increasing of intestinal permeability. Simultaneously, the intestinal mucosa also showed its great repairing potentiality, such as the improvement of the intestinal permeability and the recovery of the morphology at different phases after ischemic reperfusion injury. The restitution of gut barrier function was obviously slower than that of the morphology and there was no direct correlation between them. Compared with the small intestine, the large intestine had stronger potentiality against injury. The reduction of the amount of intestinal goblet cells by injury did not influence the ability of intestinal mucosal restitution at a certain extent and it appeared to be intimately involved in the restitution of the epithelium.

Epithelial restitution and wound healing in inflammatory bowel disease

Inflammatory bowel disease is characterized by a chronic inflammation of the intestinal mucosa. The mucosal epithelium of the alimentary tract constitutes a key element of the mucosal barrier to a broad spectrum of deleterious substances present within the intestinal lumen including bacterial microorganisms, various dietary factors, gastrointestinal secretory products and drugs. In addition, this mucosal barrier can be disturbed in the course of various intestinal disorders including inflammatory bowel diseases. Fortunately, the integrity of the gastrointestinal surface epithelium is rapidly reestablished even after extensive destruction. Rapid resealing of the epithelial barrier following injuries is accomplished by a process termed epithelial restitution, followed by more delayed mechanisms of epithelial wound healing including increased epithelial cell proliferation and epithelial cell differentiation. Restitution of the intestinal surface epithelium is modulated by a range of highly divergent factors among them a broad spectrum of structurally distinct regulatory peptides, variously described as growth factors or cytokines. Several regulatory peptide factors act from the basolateral site of the epithelial surface and enhance epithelial cell restitution through TGF-13-dependent pathways. In contrast, members of the trefoil factor family （TFF peptides） appear to stimulate epithelial restitution in conjunction with mucin glycoproteins through a TGF-13-independent mechanism from the apical site of the intestinal epithelium. In addition, a number of other peptide molecules like extracellular matrix factors and blood clotting factors and also non- peptide molecules including phospholipids~ short-chain fatty acids （SCFA）, adenine nucleotides, trace elements and pharmacological agents modulate intestinal epithelial repair mechanisms. Repeated damage and injury of the intestinal surface are key features of various intestinal disorders including inflammatory bowel diseases and require constant repair of the epithelium. Enhancement of intestinal repair mechanisms by regulatory peptides or other modulatory factors may provide future approaches for the treatment of diseases that are characterized by injuries of the epithelial surface.

Wound healing of intestinal epithelial cells

The intestinal epithelial cells(IECs) form a selective permeability barrier separating luminal content from underlying tissues.Upon injury,the intestinal epithelium undergoes a wound healing process.Intestinal wound healing is dependent on the balance of three cellular events;restitution,proliferation,and differentiation of epithelial cells adjacent to the wounded area.Previous studies have shown that various regulatory peptides,including growth factors and cytokines,modulate intestinal epithelial wound healing.Recent studies have revealed that novel factors,which include toll-like receptors(TLRs),regulatory peptides,particular dietary factors,and some gastroprotective agents,also modulate intestinal epithelial wound repair.Among these factors,the activation of TLRs by commensal bacteria is suggested to play an essential role in the maintenance of gut homeostasis.Recent studies suggest that mutations and dysregulation of TLRs could be major contributing factors in the predisposition and perpetuation of inflammatory bowel disease.Additionally,studies have shown that specific signaling pathways are involved in IEC wound repair.In this review,we summarize the function of IECs,the process of intestinal epithelial wound healing,and the functions and mechanisms of the various factors that contribute to gut homeostasis and intestinal epithelial wound healing.

Ephrin-B2 is differentially expressed in the intestinal epithelium in Crohn's disease and contributes to accelerated epithelial wound healing in vitro

AIM:Eph receptor tyrosine kinases and their membrane bound receptor-like ligands, the ephrins, represent a bi-directional cell-cell contact signaling system that directs epithelial movements in development. The meaning of this system in the adult human gut is unknown. We investigated the Eph/ephrin mRNA expression in the intestinal epithelium of healthy controls and patients with inflammatory bowel disease (IBD). METHODS: mRNA expression profiles of all Eph/ephrin family members in normal small intestine and colon were established by real-time RT-PCR. In addition, differential expression in IBD was investigated by cDNA array technology, and validated by both real-time RT-PCR and immunohistochemistry. Potential effects of enhanced EphB/ephrin-B signaling were analyzed in an in vitro IEC-6 cell scratch wound model. RESULTS: Human adult intestinal mucosa exhibits a complex pattern of Eph receptors and ephrins. Beside the known prominent co-expression of EphA2 and ephrinAl, we found abundantly co-expressed EphB2 and ephrin-B1/2. Interestingly, cDNA array data, validated by real-time PCR and immunohistochemistry, showed upregulation of ephrin-B2 in both perilesional and lesional intestinal epithelial cells of IBD patients, suggesting a role in epithelial homeostasis. Stimulation of ephrin-B signaling in ephrin- B1/2 expressing rat IEC-6-cells with recombinant EphB1-Fc resulted in a significant dose-dependent acceleration of wound closure. Furthermore, fluorescence microscopy showed that EphB1-Fc induced coordinated migration of wound edge cells is associated with enhanced formation of lamellipodial protrusions into the wound, increased actin stress fiber assembly and production of laminin at the wound edge. CONCLUSION: EphB/ephrin-B signaling might represent a novel protective mechanism that promotes intestinal epithelial wound healing, with potential impact on epithelial restitution in IBD.

Progress in researches about focal adhesion kinase in gastrointestinal tract

Focal adhesion kinase(FAK)is a 125-kDa non-receptor protein tyrosine.Growth factors or the clustering of integrins facilitate the rapid phosphorylation of FAK at Tyr-397 and this in turn recruits Src-family protein tyrosine kinases,resulting in the phosphorylation of Tyr-576 and Tyr-577 in the FAK activation loop and full catalytic FAK activation.FAK plays a critical role in the biological processes of normal and cancer cells including the gastrointestinal tract.FAK also plays an important role in the restitution,cell survival and apoptosis and carcinogenesis of the gastrointestinal tract.FAK is over-expressed in cancer cells and its over-expression and elevated activities are associated with motility and invasion of cancer cells.FAK has been proposed as a potential target in cancer therapy.Small molecule inhibitors effectively inhibit the kinase activity of FAK and show a potent inhibitory effect for the proliferation and migration of tumor cells,indicating a high potential for application in cancer therapy.

A Contact Force Model Considering Meshing and Collision States for Dynamic Analysisin Helical Gear System

The current research on gear system dynamics mainly utilizes linear spring damping model to calculate the contact force between gears. However, this linear model cannot correctly describe the energy transfer process of collision that often occurs in gear system. Focus on the contact-impact events, this paper proposes an improved gear contact force model for dynamic analysis in helical gear transmission system. In this model, a new factor associated with hysteresis damping is developed for contact-impact state, whereas the traditional linear damping factor is utilized for normal meshing state. For determining the selection strategy of these two damping factors, the fundamental contact mechanics of contact-impact event a ected by supporting forces are analyzed. During this analysis, an e ect factor is proposed for evaluating the influence of supporting forces on collision. Meanwhile, a new restitution of coe cient is deduced for calculating hysteresis damping factor, which suitable for both separation and non-separation states at the end of collision. In addition, the time-varying meshing sti ness(TVMS) is obtained based on the potential energy approach and the slice theory. Finally, a dynamic analysis of a helical gear system is carried out to better understand the contact force model proposed in this paper. The analysis results show that the contribution of supporting forces to the dynamic response of contact-impact event within gear pair is important. The supporting forces and dissipative energy are the main reasons for gear system to enter a steady contact state from repeated contact-impact state. This research proposes an improved contact force model which distinguishes meshing and collision states in gear system.

Production of aneuhaploid and euhaploid sporocytes by meiotic restitution in fertile hybrids between durum wheat Langdon chromosome substitution lines and Aegilops tauschii

Fertile F1 hybrids were obtained between durum wheat （Triticum durum Desf.） Langdon （LDN） and its 10 disomic substitution （LDN DS） lines with Aegilops tauschii accession AS60 without embryo rescue. Selfed seedset rates for hybrids of LDN with AS60 were 36.87% and 49.45% in 2005 and 2006, respectively. Similar or higher selfed seedset rates were observed in the hybrids of 1D （1A）, 1D （1B）, 3D （3A）, 4D （4B）, 7D （7A）, and 2D （2B） with AS60, while lower in hybrids of 3D （3B） ＋ 3BL, 5D （5A） ＋ 5AL, 5D （5B） ＋ 5B and 6D （6B） ＋ 6BS with AS60 compared with the hybrids of LDN with AS60. Observation of male gametogenesis showed that meiotic restitution, both first-division restitution （FDR） and single-division meiosis （SDM） resulted in the formation of functional unreduced gametes, which in turn produced seeds. Both euhaploid and aneuhaploid gametes were produced in F1 hybrids. This suggested a strategy to simultaneously transfer and locate major genes from the ancestral species T. turgidum or Ae. tauschii. Moreover, there was no significant difference in the aneuhaploid rates between the F1 hybrids of LDN and LDN DS lines with AS60, suggesting that meiotic pairing between the two D chromosomes in the hybrids of LDN DS lines with AS60 did not promote the formation of aneuhaploid gametes.

Relationship between trefoil factor 1 expression and gastric mucosa injuries and gastric cancer

AIM:To determine whether trefoil factor 1 (TFF1) is associated with mucosa healing and carcinoma suppression, we assess the expression of trefoil factor 1 in normal and pathologic gastric mucosa. METHODS: TFF1 in normal and pathologic gastric mucosa was assessed by immunohistochemical method, and the average positive A was estimated by Motic Images Advanced 3.0 software. RESULTS: Increased TFF1 was detected in gastritis, gastric ulcer and duodenal ulcer compared with normal mucosa. The same result could be seen in multiple and compound ulcer compared with simple ulcer. There was no significant difference between gastric ulcer and duodenal ulcer, gastritis and simple ulcer respectively. Increased TFF1 was detected in the peripheral mucosa of the gastric adenocarcinoma compared with normal mucosa. The expression of TFF1 in gastric adenocarcinoma was related to the differentiation of adenocarcinoma. The lower the differentiation of adenocarcinoma, the weaker the expression of TFF1. There was no TFF1 expressed in low-differentiated adenocarcinoma. The expression of TFF1 in middle and highly differentiated adenocarcinoma was a little lower than that in normal mucosa. But there was no significant difference. No TFF1 was assessed in esophageal squamous carcinoma and peripheral tissue. There was no significant difference between male and female. CONCLUSION: The expression of TFF1 was higher in gastritis and peptic ulcer than that in normal mucosa, and was also higher in multiple and compound ulcer than in simple ulcer. It seems that TFF1 plays a role in gastric mucosa protection and epithelial restitution. Increased expression of TFF1 in peripheral tissue suggests that TFF1 is associated with mechanism of carcinoma suppression and differentiation. Decreased expression of TFF1 in carcinoma and its relativity to the differentiation suggests that TFF1 is related to gland and cell destruction of carcinoma.

Gut homeostasis, injury, and healing: New therapeutic targets

The integrity of the gastrointestinal mucosa plays a crucial role in gut homeostasis,which depends upon the balance between mucosal injury by destructive factors and healing via protective factors.The persistence of noxious agents such as acid,pepsin,nonsteroidal anti-inflammatory drugs,or Helicobacter pylori breaks down the mucosal barrier and injury occurs.Depending upon the size and site of the wound,it is healed by complex and overlapping processes involving membrane resealing,cell spreading,purse-string contraction,restitution,differentiation,angiogenesis,and vasculogenesis,each modulated by extracellular regulators.Unfortunately,the gut does not always heal,leading to such pathology as peptic ulcers or inflammatory bowel disease.Currently available therapeutics such as proton pump inhibitors,histamine-2 receptor antagonists,sucralfate,5-aminosalicylate,antibiotics,corticosteroids,and immunosuppressants all attempt to minimize or reduce injury to the gastrointestinal tract.More recent studies have focused on improving mucosal defense or directly promoting mucosal repair.Many investigations have sought to enhance mucosal defense by stimulating mucus secretion,mucosal blood flow,or tight junction function.Conversely,new attempts to directly promote mucosal repair target proteins that modulate cytoskeleton dynamics such as tubulin,talin,Ehm^(2),filamin-a,gelsolin,and flightless I or that proteins regulate focal adhesions dynamics such as focal adhesion kinase.This article summarizes the pathobiology of gastrointestinal mucosal healing and reviews potential new therapeutic targets.

A theoretical model of collision between soft-spheres with Hertz elastic loading and nonlinear plastic unloading

This paper presents a theoretical model on the normal(head-on) collision between soft-spheres on the basis of elastic loading of the Hertz contact for compression process and a nonlinear plastic unloading for restitution one,in which the parameters all are determined in terms of the material and geometric ones of the spheres,and the behaviors of perfect elastic,inelastic,and perfect plastic collisions appeared in the classical mechanics are fully described once a value of coefficient of restitution is specified in the region of 0 ≤ ε ≤ 1.After an empirical formula of the coefficient of restitution dependent on the impact velocity is suggested to fit the existing experimental measurements by means of the least square method,the predictions of the dependency and the collision duration are in well quantitative agreement with their experimental measurements.It is found that the measurable quantities are dependent on both the impact velocity and the parameters of spheres.Following this model,finally,an approach to determine the spring coefficient in the linear viscoelastic model of the collision is also displayed.These results obtained here will be significantly beneficial for the applications where a collision model is requested in the simulations of relevant grain flows and impact dynamics etc..

Transformations of phosphatidylinositol phosphates in the outer and inner nuclear membrane are linked to synthesis and restitution of cellular membranes

The ultimate goal in phosphoinositides cellular metabolism is to decipher their global functional organization and coordination of the com- partmentalized signaling processes. In this report we present evidence linking nuclear phos- phoinositides cycle with endoplasmic reticulum synthesis and function. The rapid transformation of [3H]inositol-labeled phosphoinositides in the intact nuclei (IN) was captured in chase studies for 0-5 min, followed by examination of phosphatidylinositides in the inner nuclear me- mbrane (INM), the outer nuclear membrane (ONM) and endoplasmic reticulum (ER). We revealed that synthesis of phosphatidylinositol phosphates (PIPs) occurs in ONM and the de- phosphorylation takes place in the INM. The rapid transformation of the radiolabeled PIPs in ONM reverberated in their appearance and successive transformation in INM, and in the 5min chased nuclei was tracked to ONM as the re- emerging radiolabeled phosphatidylinositol (PI). These chase-uncovered changes in ONM and INM PIPs profiles allow us to conclude that the observed conversions in the nuclear membrane continuum are induced by the lateral movement of the membrane and its transit from the cytosolic to nuclear and back to cytosolic environment. The suggested membrane synthesisinduced movement provides the means to transport the membrane- and the membrane lipid ligand-associated cytosolic proteins to the intranuclear spaces and renewal of INM. Export of the nuclear components interacting with the modified INM, by exiting from nuclear to cytosolic site, endows ER with a steady influx of the membrane that is conditioned to generate vesicles according to the nucleus delivered templates.

Determination of action potential wavelength restitution in Scn5a^＋/- mouse hearts modelling human Brugada syndrome

Brugada syndrome is a primary electrical disorder of theheart, predisposing affected individuals to potentially lethal,ventricular tachy-arrhythmias. A number of mechanismshave been identified as being important increasing the riskof these rhythms. Wavelength （γ） restitution has beensuggested to predict the onset of action potential duration（APD） alternans in mouse Scn5a^＋/- hearts modelling Bru-gada syndrome.

Modeling of softsphere normal collisions with characteristic of coefficient of restitution dependent on impact velocity

This letter presents a theoretical model of the normal （head-on） collisions between two soft spheres for predicting the experimental characteristic of the coefficient of restitution dependent on impact velocity. After the contact force law between the contacted spheres during a collision is phenomenologically formulated in terms of the compression or overlap displacement under considera- tion of an elastic-plastic loading and a plastic unloading subprocesses, the coefficient of restitution is gained by the dynamic equation of the contact process once an initial impact velocity is input. It is found that the theoretical predictions of the coefficient of restitution varying with the impact velocity are well in agreement with the existing experimental characteristics which are fitted by the explicit formula.

Long-term effect of subacute ruminal acidosis on the morphology and function of rumen epithelial barrier in lactating goats

Grain-induced subacute ruminal acidosis(SARA)impairs rumen epithelial barrier function,but it is yet to be determined if SARA can cause persistent damage to the morphology and function of the rumen epithelial barrier.The objective of the present study was to investigate if SARA has persistent effects on the morphological structure and permeability of ruminal epithelium and the expression of the genes involved in epithelial barrier function using a lactating goat model.Twelve mid-lactating Saanen goats with rumen cannulas were randomly assigned to 1 of 2 groups:control group(Ctrl,n=4)fed a basal diet with a non-fiber carbohydrate(NFC)to neutral detergent fiber(NDF)ratio of 1.40,and SARA group(SARA,n=8)fed the same basal diet but with increasing NFC to NDF ratio from 1.4 to 1.79,2.31,and 3.23 overtime to induce SARA.At the end of the SARA challenge(post-SARA),4 goats were randomly selected from the SARA group and fed only hay mixture ad libitum for another 4 weeks to allow for restitution(post-SARA).Ruminal pH was continuously recorded to monitor the severity of SARA.Samples of the ventral ruminal epithelium were collected after slaughter to examine the structural and functional changes of the ruminal epithelium using transmission electron microscopy(TEM),Ussing chambers,qRT-PCR,and Western bolt analyses.Compared with the Ctrl group,ruminal papilla length,width,surface area and thickness of stratum corneum increased(P<0.05),while stratum spinosum and basale thickness,and total depth of the epithelium decreased(P<0.05)in the SARA group.These changes diminished or tended to return to the levels of the Ctrl group in the post-SARA group(P>0.05).The SARA challenge also decreased cellular junction and widened the intercellular space between epithelial cells.Rumen transepithelial short-circuit current(Isc),tissue conductance(Gt),and mucosa-to-serosa flux of paracellular horseradish peroxidase(HRP)all increased(P<0.05)both in the SARA and post-SARA groups,which indicates that SARA can induce a sustained increase in epithelial permeability and barrier dysfunction.Moreover,the mRNA and protein expressions of CLDN1,OCLN and ZO-1 were down-regulated(P<0.01)in both the SARA and post-SARA groups.The results of this study showed that SARA could result in sustained epithelial barrier dysfunction,at both structural and functional levels,which is associated with decreased expression of rumen epithelial tight junction proteins,and the restitution of rumen epithelial barrier function is slower than that of its morphology.

Analysis of force and energy density transferred to barrier in a single degree of freedom vibro-impact system

A mass-spring-damper linear oscillator with a limiting stop barrier is presented. Modeling non-smooth processes in mechanical engineering is a complex problem. It is especially for the systems with more than a single degree of freedom. But recent studies in dynamical systems have been applied to single degree of freedom systems. The vibrating system, consisting of an oscillator with amplitude of motion limited by a barrier, is known as a vibro-impact system. The amount of force and kinetic energy transferred to a barrier has an important application in designing of engineering systems that undergo the vibro-impact phenomenon. The results show the effect of changing restitution coefficient of a barrier on the amount of force and energy absorbed.

Investigation of Dynamic Behavior in 1D Non-uniform Granular System

We present a non-uniform granular system in one-dimensional case, whose granularity distribution has the fractal characteristic. The particles are subject to inelastic mutual collisions and obey Langevin equation between collisions. By Monte Carlo simulation we study the dynamic actions of the system. Far from the equilibrium, i.e., τ 〉〉 τe, the results of simulation indicate that the inhomogeneity of the system and the inelasticity of the particles have great influences on the dynamic properties of the system, and correspondingly the influence of the inhomogeneity is more significant.

RESTORATION OF THE IMAGE DEGRADED BY LINEAR MOTION

This paper introduces a new effective method to restore the uniform linear motion blurred im-age. The effect of the out-of-frame pixels on the blurring process and the estimate of these pixelsare analysed. The restoration qualities of different deblurring methods are compared. Finally, theauthors come to a conclusion that it is impossible to determine the length of blurring movement infrequency domain.

Mitochondrial Membranes Restitution Proceeds via Vesicular Import from ER and Cytosol. Counterparts’ Resemblances and Variances in Mitochondria and Golgi Pathways

The processes of mitochondrial restitution are controlled by nuclear genes that encode proteins synthesized in ER and cytosol and delivered as organelle- and membrane-specific transport vesicles. The analysis of the transporters recovered from inner mitochondrial space (Mitosol) revealed that the ER-synthesized mitochondria-specific transport vesicles consist of two carriers, one remaining in outer mitochondrial membrane (OMM), and the other that transfers specific membrane segments to the inner mitochondrial membrane (IMM). The ER-assembled and IMM-committed membrane segments, while first integrated into OMM, undergo intra-mitochondrial lipid modification reflected in the synthesis of cardiolipin (CL) and inversion into Mitosol with load of IMM associated cytosolic proteins. Then, the CL-bedecked vesicles are released from OMM to Mitosol and upon contact with IMM fuse with the membrane, and the release of cytosolic cargo ensues. While ER-assembled mitochondria-specific transport vesicles fuse with OMM with the aid of the cytosolic, phosphatidylglycerol (PG)-specific phospholipase A2 (PLA2), the Mitosol-contained CL-specific PLA guides vesicles fusion with IMM. The described path of translocation of the membrane segments and the cytosol synthesized proteins into the designated mitochondrial compartments sustains growth and identity of OMM, IMM, maintains protein delivery for intra-mitochondrial lipid and protein modification in Mitosol, and ensures conformity of the cytosolic proteins cargo delivered to matrix.

Non-Gaussian and Clustering Behavior in One-Dimensional Polydisperse Granular Gas System

We present a one-dimensional dynamic model of polydisperse granular mixture with the fractal characteristic of the particle size distribution, in which the particles are subject to inelastic mutual collisions and are driven by Gaussian white noise. The inhomogeneity of the particle size distribution is described by a fractal dimension D. The stationary state that the mixture reaches is the result of the balance between energy dissipation and energy injection. By molecular dynamics simulations, we have mainly studied how the inhomogeneity of the particle size distribution and the inelasticity of collisions influence the velocity distribution and distribution of interparticle spacing in the steady-state. The simulation results indicate that, in the inelasticity case, the velocity distribution strongly deviates from the Gaussian one and the system has a strong spatial clustering. Thus the inhomogeneity and the inelasticity have great effacts on the velocity distribution and distribution of interparticle spacing. The quantitative information of the non-Gaussian velocity distribution and that of clustering are respectively represented.