A case of multiple organ dysfunction syndrome after large area burns resulting from sustained relatively low heat

Burn as a strong traumatic stimulus can induce inflammatory responses mediated by neuroendocrine,cytokines and other inflammatory mediators,and directly lead to organ dysfunction,resulting in severe MODS.Excessive inflammatory responses caused by necrotic tissues in the burned wound,also play an important role in stimulating the occurrence and the development of MODS.Complete removal of necrotic tissues in the early stage of burns to prevent from invasive wound infections,can effectively prevent MODS.AKI occurred earlier in this case,combined with its admission after the onset of shock and no obstruction of the urinary system can exclude prerenal and renal AKI,speculated as renal AKI.The factors leading to renal AKI are divided into renal ischemia and nephrotoxicity.The patient had adequate urinary output during shock and AKI in the presence of adequate renal blood flow,possibly due to the nephrotoxicity of a large number of necrotic tissues of the wound after they were broken down and absorbed into the bloodstream.The patient fell asleep after being drunk and the bedside stove broiled him for a long time,on one hand,heat accumulation lead to skin damage;on the other hand,sustained heat action caused hyperemia,edema and hemodynamic disorder in the deep tissues,and then resulted in secondary necrosis.

Advances in the research of basic study and clinical application of adipose-derived mesenchymal stem cells

Since the discovery of adipose-derived mesenchymal stem cell (ADSC) in more than ten years, a great progress has been made from its basic research to clinical application. Compared with bone marrow mesenchymal stem cells, ADSC is more abundant in reserve, easier to obtain with fewer injuries and less complications. These cells have multiple differentiation potential and can differentiate into adipocytes, chondrocytes and osteoblasts with the influence of different inducing factors. Early studies of ADSC mainly focused on the ability of multi-directional differentiation, especially on the regeneration of bone defects and cartilage tissue. At present, the researches mainly focus on immunoregulation and paracrine function of ADSC. Although ADSC has made a great progress in clinical application, the cell preparation, use pattern, and mechanisms in clinical treatment are not clear. This paper elaborates on these issues.

A study on the relationship between changes in serum hs-CRP levels and Chinese ischemic stroke subclassification

Objective: To explore the effects of combined application of culture supernatant of human umbilical cord mesenchymal stem cells (hUCMSCs) and ciprofloxacin on Staphylococcus aureus (SA) in vitro. Methods: hUCMSCs were isolated from umbilical cord tissues of full-term healthy fetuses after cesarean section and then cultured. Cells in the third passage were chosen for the use of experiment after identification. SA strains isolated from wounds of burn patients in our burn wards were used in the following experiment. Cells were divided into 0, 10, 100 and 1,000 ng/ml lipopolysaccharide (LPS) groups by use of the random number table (similarly hereinafter). Cells were cultured with culture medium containing mesenchymal stem cells (MSCs) after being treated with medium containing corresponding mass concen-trations of LPS for 12 h. At post culture hour (PCH) 6, 12 and 24, 6 wells of culture supernatant of cells in each group were obtained to measure the content of LL-37 with enzyme-linked immunosorbent assay (ELISA). Ninety blood agar culture plates were divided into ciprofloxacin control group (CC), ciprofloxacin + supernatant group (CS), and ciprofloxacin + supernatant+ LL-37 antibody group (CSL), with 30 blood agar culture plates in each group. Blood agar culture plates in group CC were coated with 1.5 × 108 colony forming unit (CFU)/ml bacteria solution prepared with normal saline. Blood agar culture plates in group CS were coated with 1.5 × 108 CFU/ml bacteria solution prepared with normal saline and hUCMSC culture supernatant (cultured by MSC culture medium, the same below) in double volume of normal saline. Blood agar culture plates in group CSL were coated with 1.5 × 108 CFU/ml bacteria solution prepared with normal saline, hUCMSC culture supernatant in double volume of normal saline, and 2.6 μL of LL-37 antibodies at the concentration of 2 μg/ml. At PCH 12, 24 and 48, 10 blood agar culture plates were taken out from each group to observe the distribution of SA colonies on blood agar culture plates and to measure diameters of zones of inhibition of ciprofloxacin. The minimum inhibitory concentration (MIC) of ciprofloxacin against SA in each group was recorded. Fractional inhibitory concentration (FIC) indexes of ciprofloxacin in group CS and group CSL at PCH 12, 24 and 48 were calculated, with the synergistic effect evaluated. Data were processed with factorial design ANOVA, one way ANOVA, LSD-t test, Kruskal-Wallis test and Mann-Whitney U test. Results: (1) At each PCH, the content of LL-37 in cell culture supernatant in 10 ng/ml LPS group, 100 ng/ml LPS group or 1,000 ng/ml LPS group was higher than that in 0 ng/ml LPS group (with t values ranging from 11.22 to 33.36, p values all below .01);the content of LL-37 in cell culture supernatant in either 100 ng/ml LPS group or 1,000 ng/ml LPS group was higher than that in 10 ng/ml LPS group (with t values ranging from 2.24 to 18.73, p < .05 or p < .01);the content of LL-37 in cell culture supernatant in 1,000 ng/ml LPS group was higher than that in 100 ng/ml LPS group (with t values ranging from 12.46 to 14.70, p values all below .01). (2) At PCH 12, 24 and 48, the bacterial colonies in groups CC, CS and CSL became integrated over time. In CC group, diameters of zones of inhibition of ciprofloxacin at PCH 12, 24 and 48 were 26 mm, 24 mm and 23 mm respectively, with no obvious changes. At PCH 12, 24 and 48, diameters of zones of inhibition of ciprofloxacin in groups CS and CSL were 82 mm, 71 mm, 68 mm and 74 mm, 59 mm, 56 mm respectively, which were significantly larger than those in group CC. (3) At each PCH, MIC of ciprofloxacin against SA in group CC was significantly higher than that in groups CS and CSL respectively (with Z values ranging from 6.22 to 6.71, p values all below .01);MIC of ciprofloxacin against SA in group CSL was significantly higher than that in group CS (with Z values all equal to 6.72, p values all below .01). (4) FIC indexes of ciprofloxacin in groups CS and CSL at PCH 12, 24 and 48 were 0.011, 0.032, 0.032 and 0.122, 0.350, 0.350, respectively. The results indicated that hUCMSC culture supernatant had a synergistically antibacterial effect when combined with ciprofloxacin. Conclusions: hUCMSCs can secrete LL-37, and the secretion level is improved with increase of LPS concentration. The com-bination of hUCMSC culture supernatant with ciprofloxacin can decrease the dosage of ciprofloxacin in resisting SA effectively. Once LL-37 is neutralized, the synergistically antibacterial effect of hUCMSC culture supernatant is decreased thereby.

Experimental study of kidney protective effects of sanhuangshaoshangling on severe burn rats in shock stage

Objective:To observe the protective effects and mechanisms of topical Chinese medicine on kidneys of severe burns shock rats.Methods:Blood urea nitrogen(Bun),creatinine(Cr),myeloperoxidase(MPO),tumor necrosis factor-α(TNF-α)and inter-leukin(IL-6),were checked by the time points of 8,24,48 hours.Blood tests,ELISA and other methods were used for these texts.Results:Compared with the povidone-iodine group,the levels of Bun and Cr were declined apparently in the Sanhuang group,and the activity of MPO was decreased as well.Conclusions:Sanhuangshaoshangling,taking ointment as matrix,can be externally applied to wounds.It contains some ef-fective ingredients which can clear heat-toxicity and promote blood circulation for removing blood stasis,and prevents wounds from the stimulation of the air to nerve endings and the invasion of bacteria.It can also inhibit bacteria from parasitizing,grow-ing,reproducing on the wound.Sanhuangshaoshangling helps blood circulation and facilitates the growth of tissues to inactivate the toxicity or reduce toxin by changing the structure of endotoxin after uptake into tissues.It can protect viscera by reducing the release of endotoxin,facilitating the excretion of endotoxin and weakening or eliminating the effects of TNF-αand IL-6.

Significance of D-dimer assay in the diagnosis of acute pulmonary embolism after deep second-degree burn in rabbits

Objective: To explore the significance of D-dimer assay in the diagnosis of acute pulmonary embolism (APE) after deep second-degree burn by detecting the changes of plasma D-dimer in rabbits with deep second-degree burn and in different phases of burn with concomitant pulmonary embolism. Methods: 48 healthy male or female Chinese white rabbits, were randomly divided into: control group, burn group, burn shock group, burn shock + pulmonary embolism group, burn infection group and burn infection + pulmonary embolism group, with 8 rabbits in each group. By use of the ELISA method, the plasma D-dimer was determined on 1 d, 3 d, 5 d, 7 d, 14 d and 21 d after modeling in the burn group and the control group, and the plasma D-dimer in other groups was detected in 30 min, 1 h, 3 h, 6 h, 24 h after modeling. Results: The expression of D-dimer in the burn group was higher than that in the control group on 1 d, 3 d, 5 d and 7 d (p < .05). There were significant differences in the expression of D-dimer in the burn shock + pulmonary embolism group in comparison to the burn shock group (p < .05). There were also some significant differences in the expression of D-dimer in the burn infection+ pulmonary embolism group in comparison with the burn shock + pulmonary embolism group (p < .05). Conclusions: There were some differences in the expression of D-dimer in each group. D-dimer can be used as one of diagnostic indexes for deep second-degree burn with pulmonary embolism.

Experimental study on the protective effect of ulinastatin on lung tissue in rats with severe scalded

Objective:To explore the potential protective effects of ulinastatin on ventilation-induced lung injuries of severe burned rats.Methods:Ninety Wistar rats were randomly divided into three experimental groups:the control group(n=30),the ventilation group(n=30)and the ventilation-ulinastatin group(n=30).After establishing the severe burn model,the rats of latter two groups were mechanically ventilated for 1 hour with or without the pre-treatment of ulinastatin.After severe scald,the protective effect of ulinastatin on lung injury caused by mechanical ventilation was estimated through the observation of the tissues samples,and evaluation of the pathological changes of lung tissue by HE staining,ultrastructure change by electron microscopy,lung coefficient,and the expression levels of lung tissue cytokines TNF-α,IFN-γ,IL-2 by immunohistochemical staining.Results:Edema in lung tissues of the control group and the ventilation group was obvious,the hemorrhagic focus could be seen,and the cut surface was observed to be scattered and swelling;Edema in lung tissues of the ventilation-ulinastatin group was mild.HE staining revealed that the pathological changes of the ventilation-ulinastatin group were milder than the ventilation group.Under the electron microscope,the lung tissue organelles of the control group and the ventilation group were seriously damaged;the corresponding changes in the ventilation-ulinastatin group were lighter.The lung coefficient of the ventilation-ulinastatin group was significantly lower than that in the ventilation group.The immunohistochemical results showed that the intensity of TNF-α,IL-2 and IFN-γin lung tissue of the ventilation-ulinastatin group was significantly lower than that in the ventilation group.Conclusions:Ulinastatin has protective effects on lung injury caused by mechanical ventilation in severe scalded rats,whose mechanism may be related to the capacity of ulinastatin to reduce the expression of cytokines including TNF-α,IL-2 and IFN-γ.

The expression of COX-2 and VEGF in mixed grafting of sheepskin and autoskin in rats

Objective:To investigate the expression of cycloxygenase-2(COX-2),and vascular endothelial growth factor(VEGF)by using immunohistochemistry method and observe the changes of histological structure between the all skin group and the xenoskin(sheepskin)group,and explore the effect of the xenoskin(sheepskin)which is a kind of covering of autogenous microskin grafting.Methods:A total of 180 Wistar healthy male rats were randomly divided into 3 groups:the autoskin group(the control group),the alloskin group and the xenoskin group(the sheepskin group),with 60 rats in each group.By using immunohistochemistry method,the expression of COX-2 and VEGF were revealed on 3,5,7,14,21 and 28 d,with 10 executed rats in each group on each time points,and the structure of histology was observed by light microscope.Results:There were obvious difference of expression of COX-2 and VEGF on wound in the autoskin group compared with other two groups(p<.01);but there were no differences between the alloskin group and xenoskin group(p>.05).Observed on light microscope,the paralleled collagen and elastic fiber appeared in the autoskin group on 14 post-transplantation days,but they appeared in the alloskin group and the xenoskin group only on 21 post-transplantation days.Conclusions:There were no differences of the expression of COX-2 and VEGF in the alloskin group and the xenoskin group,which provided clinical theoretical basis on sheepskin as a substitute for the alloskin to cover autogenous microskin.

Study on integrated treatment of severe burn in batch patients

Objective:To explore the burn treatment and first aid flow mode in batch patients.Methods:A retrospective analysis was performed on the treatment experience of 10 or more patients in the group burn accident admitted to the Third Affiliated Hospital of Inner Mongolia Medical University from 2008 to 2020,in order to acquire the general information(e.g.,age,sex[male and female],injury causes and factors,total burn surface area,inhalation injury and compound injury),the time when each first-aid rescue team was in place;the reception time of the triage group;specialist rescue start time;treatment process and treatment outcome in patients with severe burns,such as the establishment time of deep venous access.Results:67 cases(n=68)of patients were cured and the curative ratio was 98.5%.The average time from the rescue order of the commander-in-chief to the placement of each medical group was 8.8 minutes,the average reception time of the triage group was 4.5 minutes,the average specialist rescue start time was 18.6 minutes,and the average establishment time of deep vein access for patients with severe burns was about 11.3 minutes.Conclusions:Scientific and reasonable pre-hospital emergency triage and treatment for burn patients can be achieved by implementing integrated treatment.

Analysis of the impact of COVID-19 on some medical institutions in a certain region

Objective:This study is designed to analyze the impact of COVID-19 on hospitals in a certain region through the statistical comparison of outpatient,emergency and inpatient data of three representative AAA hospitals in this region from January and February of 2019 and 2020.Methods:Relevant outpatient,emergency and inpatient data of three representative AAA hospitals in a certain region from January and February of 2019 and 2020 were collected,and the statistical analysis was conducted by using EXCEL 2019 and SPSS20.0.Results:In January and February of 2020,the number of the outpatient,the emergency,the inpatient and the inpatient surgical interventions in the three hospitals was significantly decreased in comparison with the same period in 2019,and the change of the emergency dispatching amount was relatively small.The mortality of the inpatient in January and February in 2020 was about 2.82%,and that in the same period in 2019 was about 1.51%,with an increase of about 1.31%,which presented a statistically significant difference(χ^(2)=348.422;p=.000).Conclusions:The outbreak of COVID-19 had a great impact on the normal operation of the hospital.

Acinetobacter baumannii biofilm resistance mechanisms and prevention and control of progress

At present,the multiple drug resistance of Acinetobacter baumannii outbreaks worldwide and has intensified the trend,especially in the intensive care unit and burn ward.Generic drug resistant Acinetobacter baumannii is known as the 21st century gram-negative bacterium“MRSA”,“Superbugs”.In recent years,researches have shown that this is associated with pathogenic bacteria to form biofilms.In this paper,the status of Acinetobacter baumannii infection,biofilm formation,resistance mechanism and prevention in recent years were summarized.

Influence of thymopentin-5 on renal pathology and relevant indexes of serum in rats with acute kidney injury caused by sepsis

Objective:To discuss thymopentin-5 on renal pathology and relevant indexes of serum with sepsis-caused acute kidney injury(AKI)caused by cecal ligation and puncture(CLP).Methods:90 cases of healthy and male SD rats were randomly divided into 3 groups:control group(C group),sepsis group(S group),thymopentin group(T group).These groups were divided into five time point including 1 h,6 h,12 h,24 h and 48 h with 6 rats in each time point.The sepsis model was made by CLP.The blood and kidney tissue were collected in each time point.Changes of renal pathology were observed under light microscope and relevant indexes like serum creatinin(Cr),blood urea nitrogen(Bun),tumor necrosis factorα(TNF-α),interleukin-10(IL-10),CD4+/CD8+were tested and analyzed.Results:In T group,concentrations of Cr,Bun in 6 h after CLP started to rise,reached peak in 24 h and decreased in 48 h,which were all lower than S group(p<.05)and higher than C group(p<.05).Compared with C group,concentrations of TNF-αin 1 h significantly improved,reached peak in 12 h and decreased in 24 h,which were all lower than S group(p<.05);and concentrations of IL-10 in 1 h significantly decreased,reached peak in 12 h and rised in 24 h,which were all more than S group(p<.05).In T group,CD4+/CD8+ratio in 6 h after CLP started to decrease,reached the lowest in 24 h and rised in 48 h,which were all lower than S group(p<.05)and significantly lower than C group(p<.05).Conclusions:Thymopentin-5 plays the role of renal protection in AKI caused by sepsis.

Successful treatment of severe burn patients with multiple organ dysfunction syndrome:A case report

Multiple organ dysfunction syndrome is the presence of altered organ function of two or more organ systems in acute ill patients with severe trauma,burn,shock and infection.In this case,the patient with burn area amounted to 95%and the third-degree burn was up to 90%.He underwent gastrointestinal tract,blood clotting,lung,brain,heart,liver dysfunction,and cardiac arrest for 30 minutes during the courses of treatment,and was discharged from the hospital after 108 days on the basis of comprehensive treatment and repeated skin grafting.

Machine learning for predicting fatigue properties of additively manufactured materials

Fatigue properties of materials by Additive Manufacturing(AM) depend on many factors such as AM processing parameter, microstructure, residual stress, surface roughness, porosities, post-treatments, etc. Their evaluation inevitably requires these factors combined as many as possible, thus resulting in low efficiency and high cost. In recent years, their assessment by leveraging the power of Machine Learning(ML) has gained increasing attentions. A comprehensive overview on the state-of-the-art progress of applying ML strategies to predict fatigue properties of AM materials, as well as their dependence on AM processing and post-processing parameters such as laser power, scanning speed, layer height, hatch distance, built direction, post-heat temperature,etc., were presented. A few attempts in employing Feedforward Neural Network(FNN), Convolutional Neural Network(CNN), Adaptive Network-Based Fuzzy Inference System(ANFIS), Support Vector Machine(SVM) and Random Forest(RF) to predict fatigue life and RF to predict fatigue crack growth rate are summarized. The ML models for predicting AM materials' fatigue properties are found intrinsically similar to the commonly used ones, but are modified to involve AM features. Finally, an outlook for challenges(i.e., small dataset, multifarious features,overfitting, low interpretability, and unable extension from AM material data to structure life) and potential solutions for the ML prediction of AM materials' fatigue properties is provided.

Distributed energy management for interconnected operation of combined heat and power-based microgrids with demand response

From the perspective of transactive energy, the energy trading among interconnected microgrids(MGs) is promising to improve the economy and reliability of system operations. In this paper, a distributed energy management method for interconnected operations of combined heat and power(CHP)-based MGs with demand response(DR) is proposed. First, the system model of operational cost including CHP, DR, renewable distributed sources, and diesel generation is introduced, where the DR is modeled as a virtual generation unit. Second, the optimal scheduling model is decentralized as several distributed scheduling models in accordance with the number of associated MGs. Moreover, a distributed iterative algorithm based on subgradient with dynamic search direction is proposed. During the iterative process, the information exchange between neighboring MGs is limited to Lagrange multipliers and expected purchasing energy. Finally,numerical results are given for an interconnected MGs system consisting of three MGs, and the effectiveness of the proposed method is verified.

A Two-stage Robust Optimal Allocation Model of Distributed Generation Considering Capacity Curve and Real-time Price Based Demand Response

Demand response, the reactive power output of distributed generation(DG), and network reconfiguration have significant impacts on a DG allocation strategy. In this context, a novel real-time price-based demand response formulation is integrated into the allocation model of DG. The tariff is regulated by the difference between the load and active power of renewable energy. Meanwhile, network reconfiguration and the capacity curve describing the active and reactive power limits of DG are included in the optimization model for promoting the allocation of DG.With these measures, the optimal allocation model of DG is established with the goal of maximizing the net annual profit while guaranteeing the efficient utilization of renewable energy. In addition, the uncertainties of renewable energy are considered on the basis of a two-stage robust optimization method. Finally, the entire optimization model is solved by the column and constraint generation algorithm in the IEEE 33-bus distribution system and a practical 99-bus distribution system. Numerical simulations show that the proposed model is effective in terms of improving both the usage of renewable energy and net annual profit.

Reliability Evaluation and Improvement of Islanded Microgrid Considering Operation Failures of Power Electronic Equipment

With the high integration of power electronic technologies in microgrids,the reliability assessment considering power electronic devices has become a hot topic.However,so far no research has considered the impact of the operation failure probability of power electronic equipment on the overall reliability of the microgrid.This paper aims to construct a holistic operation failure rate model of power electronic systems based on the overall reliability assessment of islanded microgrid with high penetration of renewable energy sources(RESs).In addition,to improve the reliability of islanded microgrid,the conventional battery energy storage system(BESS)is replaced by the hybrid energy storage system(HESS).Based on the proposed model,the operation failure models for the power electronic modules in microgrid are built and tested,and then the sensitivity analysis is performed for exploring the influence of various factors on the reliability of the microgrid.

Prediction of combined cycle fatigue life of TC11 alloy based on modified nonlinear cumulative damage model

The nonlinear cumulative damage model is modified to have high prediction accuracy when the high-low cycle stress frequency ratio m is large(m500).The low cycle fatigue(LCF)tests,high cycle fatigue(HCF)tests and combined high and low cycle fatigue(CCF)tests of TC11 titanium alloy were carried out,and the influencing factors of CCF life were analysed.The CCF life declines with the decrease of the ratio of high-low cycle stress frequency m.Both linear and nonlinear cumulative damage models are used to predict the CCF life.The CCF life prediction error of the linear cumulative damage model is great and the predictions tend to be overestimated,which is dangerous for engineering application.The accuracy is relatively high when the high-low cycle stress frequency ratio m500.The accuracy of nonlinear cumulative damage model is higher than that of linear model when the high-low cycle stress frequency ratio m500.Based on the relationship between high cycle average stress rmajor and material yield limit rp,0.2,a correction term is added to the nonlinear cumulative damage model and verified,which made the modified model more accurate when m500.

A Data-driven Distributionally Robust Operational Model for Urban Integrated Energy Systems

A multi-energy conversion can effectively increase the utilization of renewable energy in the urban integrated energy system(UIES).Meanwhile,the uncertainties of renewable energy resources(e.g.,wind energy)also bring increased challenges to the operation of UIES.In this study,a typical two-stage datadriven distributionally robust operation(DDRO)model based on finite scenarios is proposed for UIES including power,gas and heat networks to obtain a salient strategy from both an economic and robustness perspective.In the first stage,the forecasted information for wind power is especially included to improve the economic aspect of robust decisions.The worst probability distribution for the selected known real-time wind power scenarios can be identified in the second stage where the power differences caused by the real-time uncertainties of wind power can be mitigated by flexible regulation of energy purchasing and coupling units(such as gas turbine,power to gas equipment,electric boiler and gas boiler).Moreover,norm-1 and norm-inf co-constraints are utilized to construct a confidence set for the probability distributions of uncertain wind power.The whole two-stage model is solved by the column-and-constraint generation(CCG)algorithm.Finally,case studies are conducted to show the performance of the proposed model and various approaches.Index Terms-Data-driven methods,distributionally robust optimization,urban integrated energy system,wind power.