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1.
Study progress on mechanism of severe acute pancreatitis complicated with hepatic injury 总被引：4，自引：0，他引：4
Study on the action mechanism of inflammatory mediators generated by the severe acute pancreatitis(SAP) in mul-tiple organ injury is a hotspot in the surgical field.In clinical practice,the main complicated organ dysfunctions are shock,res-piratory failure,renal failure,encephalopathy,with the rate of hepatic diseases being closely next to them.The hepatic injury caused by SAP cannot only aggravate the state of pancreatitis,but also develop into hepatic failure and cause patient death.Its complicated pathogenic mechanism is an obstacle in clinical treatment.Among many pathogenic factors,the changes of vasoac-tive substances,participation of inflammatory mediators as well as OFR(oxygen free radical),endotoxin,etc.may play important roles in its progression. 相似文献
2.
Mechanism of acute pancreatitis complicated with injury of intestinal mucosa barrier 总被引：4，自引：0，他引：4
Acute pancreatitis （AP） is a common acute abdomen in clinic with a rapid onset and dangerous pathogenetic condition AP can cause an injury of intestinal mucosa barrier, leading to translocation of bacteria or endotoxin through multiple routes, bacterial translocation （BT）, gutorigin endotoxaemia, and secondary infection of pancreatic tissue, and then cause systemic inflammatory response syndrome （SIRS） or multiple organ dysfunction syndrome （MODS）, which are important factors influencing AP＇s severity and mortality. Meanwhile, the injury of intestinal mucosa barrier plays a key role in AP＇s process. Therefore, it is clinically important to study the relationship between the injury of intestinal mucosa barrier and AP. In addition, many factors such as microcirculation disturbance, ischemical reperfusion injury, excessive release of inflammatory mediators and apoptosis may also play important roles in the damage of intestinal mucosa barrier. In this review, we summarize studies on mechanisms of AP. 相似文献
3.
ZHANG Xi-ping ZHANG Jie SONG Qiao-ling CHEN Han-qin 《Journal of Zhejiang University. Science. B》2007,(12)
Acute pancreatitis (AP) is a common acute abdomen in clinic with a rapid onset and dangerous pathogenetic condition. AP can cause an injury of intestinal mucosa barrier, leading to translocation of bacteria or endotoxin through multiple routes, bacterial translocation (BT), gutorigin endotoxaemia, and secondary infection of pancreatic tissue, and then cause systemic in- flammatory response syndrome (SIRS) or multiple organ dysfunction syndrome (MODS), which are important factors influencing AP’s severity and mortality. Meanwhile, the injury of intestinal mucosa barrier plays a key role in AP’s process. Therefore, it is clinically important to study the relationship between the injury of intestinal mucosa barrier and AP. In addition, many factors such as microcirculation disturbance, ischemical reperfusion injury, excessive release of inflammatory mediators and apoptosis may also play important roles in the damage of intestinal mucosa barrier. In this review, we summarize studies on mechanisms of AP. 相似文献
4.
Severe acute pancreatitis （SAP） is a common acute abdomen clinical problem characterized by high mortality, multiple complications, complicated pathogenesis and difficult treatment. Recent studies found traditional Chinese medicine （TCM） monomers have markedly good effect for treating SAP. Many TCM monomers can inhibit pancreatin, resist inflammation, improve microcirculation and immunoloregulation, etc. to block the pathological progress of SAP in multiple ways, reduce complications and lower mortality with rapid effects. It is significant for enhancing SAP treatment to deeply understand the current situation in TCM monomers for treating SAP and take precious references therein. This article summarizes the treating effects and mechanisms of TCM monomers for SAP in recent years. 相似文献
5.
Preconditioning （PC） has emerged as a powerful method for experimentally and clinically attenuating various types of organ injuries. In this paper related clinical and basic research issues on organ preconditioning issues were systemically reviewed. Since lung injuries, including ischemia-reperfusion and others, play important roles in many clinical results, including thromboembolism, trauma, thermal injury, hypovolemic and endotoxin shock, reimplantation response after organ transplantation, and many respiratory diseases in critical care. It is of interest to uncover methods, including the PCs, to protect the lung from the above injuries. However, related studies on pulmonary PC are relatively rare and still being developed, so we will review previous literature on experimental and clinical studies on pulmonary PC in the following paragraphs. 相似文献
6.
Objective: To explore the characteristics of NF-κB activation in the progress of pancreatitis, the relationship with expression of TNF-α in the inflammatory reaction, and prevent the exacerbation of pancreatitis by using NAC. Method: Forty-eight rats were divided into three groups: therapy (group C), pancreatitis (group B) and control (group A). NAC served as the inhibitor of NF-κB activation. In the time intervals of 1.5, 3.0, 6.0, 12.0 hour, NF-κB activation was detected with flow cytometry (FCM) and the expression of TNF-α mRNA and protein with in situ hybridization (ISH) and enzyme-linked immuno-sorbent assay (ELISA) respectively. Meanwhile, the level of lipase and amylase in the serum was assayed and the pathological change was evaluated. Result: NF-κB activation in the pancreatitis group was higher than that in the control group (P<0.01), peaked at 3 hours, and was depressed by the inhibitor of NF-κB, NAC. The expression of TNF-α as well as the level of lipase and amylase in the serum also rose synchronously with activation of NF-κB. In contrast to group A, it was significantly different (P<0.01) in group B. After using NAC in group C, all of these values were decreased and the inflammatory reaction in the pancreas abated evidently. The pathology changes of the pancreas were shown to be alleviated in group C. Conclusion: First, NF-κB activity is intensively initiated in the course of pancreatitis and shown to have closely relationship with the release of cytokines. Second, use of NAC markedly depressed NF-κB activation. TNF-α expression is down regulated by cytokines. It is suggested that NAC probably acts as a useful agent for treatment of pancreatitis by indirectly inhibiting activation of NF-κB. 相似文献
7.
Study progress in therapeutic effects of traditional Chinese medicine monomer in severe acute pancreatitis 总被引：8，自引：0，他引：8
INTRODUCTION Severe acute pancreatitis (SAP) is one of the three main acute abdominal problems always ac-companied by multiple-system and multiple-organ impaired function or failure. Its onset and develop-ment are characterized by rapid changes, complicated illness state and difficult treatment. With the con-tinuous development of the traditional Chinese medicine industry in recent years, it is proved that traditional Chinese medicine (TCM) monomers monomers have a marked effect for … 相似文献
8.
Cell therapy in congestive heart failure 总被引：5，自引：0，他引：5
Congestive heart failure （CHF） has emerged as a major worldwide epidemic and its main causes seem to be the aging of the population and the survival of patients with post-myocardial infarction. Cardiomyocyte dropout （necrosis and apoptosis） plays a critical role in the progress of CHF; thus treatment of CHF by exogenous cell implantation will be a promising medical approach. In the acute phase of cardiac damage cardiac stem cells （CSCs） within the heart divide symmetrically and/or asymmetrically in response to the change of heart homeostasis, and at the same time homing of bone marrow stem cells （BMCs） to injured area is thought to occur, which not only reconstitutes CSC population to normal levels but also repairs the heart by differentiation into cardiac tissue. So far, basic studies by using potential sources such as BMCs and CSCs to treat animat CHF have shown improved ventricular remodelling and heart function. Recently, however, a few of randomized, double-blind, placebo-controlled clinical trials demonstrated mixed results in heart failure with BMC therapy during acute myocardial infarction. 相似文献
9.
《浙江大学学报(A卷英文版)》2013,(11):834-834
Hydrogen is starting to be mentioned as an alternative fuel to replace the fossil fuel in future transportation applications due to its characteristics of zero greenhouse gas emission and high energy effi- ciency. Before hydrogen fuel and its facilities can be introduced to the public, relevant safety issues and its hazards must be assessed in order to avoid any chance of injury or loss. While a traditional risk assessment has difficulty in prioritizing the risk of failure modes, this paper proposes a new fuzzy-based risk evaluation tech- nique which uses fuzzy value to prioritize the risk of various scenarios. In this study, the final risk of each failure modes was prioritized by using the MATLAB fuzzy logic tool box with a combination of two assess- ments. The first assessment was concerned with the criteria which affected the actual probability of occurrence. This assessment considered the availability of the standard that was applied to prevent the likelihood of the scenario occurring. On the other hand, the second assessment was focused on evaluating the consequence of the failure by taking into account the availability of detection and the complexity of the failure rather than only the severity of the scenarios. A total of 87 failure scenarios were identified using failure modes and effect analysis （FMEA） procedures on hydrogen refueling station models. Fuzzy-based assessments were performed through risk prioritizing various failure scenarios with a fuzzy value （0 to 1） and risk level （low, medium, and high） while a traditional risk assessment approach presented the risks only in forms of level （low, medium, and/or high）. Availability of the fuzzy value enabled further prioritizing on the risk results that fell in the same level of risk. This study concluded that fuzzy-based risk evaluation is able to further prioritize the decisions when compared with a traditional risk assessment method. 相似文献
10.
Hydrogen is starting to be mentioned as an alternative fuel to replace the fossil fuel in future transportation applica- tions due to its characteristics of zero greenhouse gas emission and high energy efficiency. Before hydrogen fuel and its facilities can be introduced to the public, relevant safety issues and its hazards must be assessed in order to avoid any chance of injury or loss. While a traditional risk assessment has difficulty in prioritizing the risk of failure modes, this paper proposes a new fuzzy-based risk evaluation technique which uses fuzzy value to prioritize the risk of various scenarios. In this study, the final risk of each failure modes was prioritized by using the MATLAB fuzzy logic tool box with a combination of two assessments. The first assessment was concerned with the criteria which affected the actual probability of occurrence. This assessment considered the availability of the standard that was applied to prevent the likelihood of the scenario occurring. On the other hand, the second assessment was focused on evaluating the consequence of the failure by taking into account the availability of detection and the complexity of the failure rather than only the severity of the scenarios. A total of 87 failure scenarios were identified using failure modes and effect analysis （FMEA） procedures on hydrogen refueling station models. Fuzzy-based assessments were performed through risk prioritizing various failure scenarios with a fuzzy value （0 to 1） and risk level （low, medium, and high） while a tra- ditional risk assessment approach presented the risks only in forms of level （low, medium, and/or high）. Availability of the fuzzy value enabled further prioritizing on the risk results that fell in the same level of risk. This study concluded that fuzzy-based risk evaluation is able to further prioritize the decisions when compared with a traditional risk assessment method. 相似文献
11.
Though the bumper of a vehicle plays a major role in protecting the vehicle body against damage in low speed impacts, many bumpers, particularly in large vehicles, are too stiff for pedestrian protection. In designing a bumper for an automobile, pedestrian protection is as important as bumper energy absorption in low speed collisions. To prevent lower extremity injuries in car-pedestrian collisions, it is important to determine the loadings that car front structures impart on the lower extremities and the mechanisms by which injury is caused by these loadings. The present work was focused on gaining more insight into the injury mechanisms leading to both ligament damage and bone fracture during bumper-pedestrian collisions. The European Enhanced Vehicle-safety Committee （EEVC） legform impactor model was introduced and validated against EEVCAVG17 criteria. The collision mechanism between a bumper and this legform impactor was investigated numerically using LS-DYNA software. To identify the effect of the bumper beam material on leg injuries, four analyses were performed on bumpers that had the same assembly but were made from different materials. 相似文献
12.
Yee-Meng Chiew 《天津大学学报(英文版)》2008,14(4):289-295
This paper examines scour and scour countermeasures at bridge piers and abutments. Abutment scour is by far more complex than its counterpart associated with piers because of the possibility of the presence of a floodplain. Notwithstanding this, the mechanism of scour at both piers and abutments is very similar; moreover, the failure mechanisms associated with both armoring and flow-altering countermeasures are not very different. In rivers with a floodplain, abutment scour becomes much more complex. In cases where the abutment ends at or near to the floodplain, it can initiate bank erosion, which clearly is an important erosion problem that is quite distinct from the customary scour at either an abutment in rivers without a floodplain or a pier. For this reason, abutment scour can be very site-specific while pier-scour is more generic in nature. To this end, the ability to identify the type of abutment scour that may form in a particular channel is closely related to an engineer＇s ability to propose devices for effective scour countermeasure.By summarizing research efforts on using riprap as a pier or abutment countermeasure over the past few decades, this paper highlights the deficiencies of riprap in arresting pier scour. To this end, different failure mechanisms are identified. They are shear failure, winnowing failure, edge failure, bedform-induced failure and bed-degradation induced failure. Each failure mechanism can singly or, more likely, combine to cause the eventual breakdown of the riprap layer. The study shows that a riprap layer is vulnerable to other failure mechanisms even though it is adequately designed against shear failure, rendering it ineffective in arresting scour. 相似文献
13.
A model of dynamic programming for repairing strategies of concrete structures during a projected service period is proposed,which takes into account the degradation in strength of components and the probability of accidental load.This model takes the safety grade of a structural system as the state variable of repairing strategies,and incorporates economic factors including expected repair cost,property loss due to structure failure,goods and material loss due to structure failure,loss of production interrupt due to structure failure,and inspection cost in decision making.It is found that the optimal repairing strategies are sensitive to the probability of accidental loads as well as the failure costs.The practicality of the model is demonstrated by an example. 相似文献
14.
The retention of sulfamethoxazole （SMZ） by nanofiltration （NF） membranes is strongly influenced by the pH value of the solution. The retention of SMZ reaches its peak value when the solution pH rises above its PKa2 value as the compound transforms into a negatively charged species. Charge repulsion is the main mechanism involved in SMZ removal by NF membranes. In this study, the removal of SMZ by NF membranes, as a function of solution chemistry, was examined at pH 8.9 to investigate the effect of solution conditions on charge repulsion. The results show that the retention of negatively charged SMZ is relatively independent of SMZ concentration, and an increase in the ionic strength of the solution causes a relatively small reduction in retention. A small effect of humic acid （HA） on SMZ retention was noticed at pH 8.9, which can be explained by a small but insignificant improvement in the zeta potential of the membrane caused by HA at high pH values. However, it was found that SMZ concentration in the feed decreased significantly in solutions containing tannic acid （TA）. The Adams-Bohart model was applied to our experimental data and was found to be suitable for describing the initial part of the breakthrough curves. The adsorptive parameters of the membrane were determined. 相似文献
15.
Failure Process and Energy Transmission for Single-Layer Reticulated Domes Under Impact Loads 总被引：5，自引：0，他引：5
No failure, moderate failure, severe failure, and slight failure are the four failure modes generalized observed in the dynamic response of the single-layer reticulated dome under vertical impact load on apex. TE (the time that the end of impact force) and TF (the time that members are broken) are two key times in the failure process. Characteristics of dynamic responses at the two key times are shown in order to make the failure mechanism clear. Then three steps of energy transfer are summarized, i.e. energy applying, energy loss and energy transfer, energy consump-tion. Based on the three steps, energy transfer process for the failure reticulated dome under once impact is introduced. Energy transmissibility and local loss ratio are put forward firstly to obtain EL F(the energy left in the main reticulated dome) from the initial kinetic energy of impactor. More-over, the distribution of failure modes is decided by EL F which leads to the maximum dynamic re-sponse of the reticulated dome, but not by the initial impact kinetic energy of impactor. 相似文献
16.
The failure analysis of simply supported, isotropic, square plates is addressed. Attention focuses on minimum failure load amplitudes and failure locations, von Mises＇ equivalent stress along the plate thickness is also addressed. Several distributed and localized loading conditions are considered. Loads act on the top of the plate. Bi-sinusoidal and uniform loads are taken into account for distributed loadings, while stepwise constant centric and off-centric loadings are addressed in the case of localized loadings. Analysis is performed considering plates whose length-to-thickness ratio a/h can be as high as 100 （thin plates） and as low as 2 （very thick plates）. Results are obtained via several 2D plate models. Classical theories （CTs） and higher order models are applied. Those theories are based on polynomial approximation of the displacement field. Among the higher order theories （HOTs） HOTsa models account for the transverse shear deformations, while HOTs models account for both transverse shear and transverse normal deformations. LHOTs represent a local application of the higher order theories. A layerwise approach is thus assumed： by means of mathematical interfaces, the plate is considered to be made of several fictitious layers. The exact 3D solution is presented in order to determine the accuracy of the results obtained via the 2D models. In this way a hierarchy among the 2D theories is established. CTs provide highly accurate results for a/h greater than 10 in the case of distributed loadings and greater than 20 for localized loadings. Results obtained via HOTs are highly accurate in the case of very thick plates for bi-sinusoidal and centric loadings. In the case of uniform and off-centric loadings a high gradient is present in the neighborhood of the plate top. In those cases, LHOTs yield results that match the exact solution. 相似文献
17.
18.
Chinese Learners’ pragmatic failure can be divided into pragmalinguistic failure and sociopragmatic failure.Pragmalinguistic failure stems from inappropriate pragmalinguistic transfer and teaching-induced errors.Sociopragmatic failure is mainly caused by cross-cultural differences in the assessment of such socio-cultural variables as size of imposition and social distance,and also by the deviation from rules of speaking.Inappropriate teaching materials are also an important cause of Chinese learners’ sociopragmatic failure. 相似文献
19.
This essay is to help TESOL teachers to think about their importance of being the cultural mediators and how to be good mediators as well.Firstly,in this article,some concepts about language,culture and the connections between them are intro duced.Then it explores why it is important for English teachers to view themselves as cultural mediators and in what way they are cultural mediators.Finally,the study reflects on the situation in a tertiary teaching context. 相似文献
20.
Immunomodulatory function of orally administered thymosin α1 总被引：1，自引：0，他引：1
Chen XM Jiang HL Zhou LF Pan XP Hu ZR Liu RH Chen XM Chen Z 《Journal of Zhejiang University. Science. B》2005,6(9):873-876
INTRODUCTION The thymus is a vital immune organ and plays a very important role in the development and mainte- nance of the lymph system. The extract of animal thymus has been used in clinical practice as an ad- junct treatment in patients with carcinoma, viral in- fection and immunodeficiency, but the extract con- taining miscellaneous animal proteins may easily lead to allergy in patients. Thymosin α1 (Tα1) is the most potent ingredient in thymosin and the biological ac- tivity of pur… 相似文献