Protective effects of baffles with different positions,row spacings,heights on debris flow impact

The baffle effectively slowed down debris flow velocity,reduced its kinetic energy,and significantly shortened the distance of debris flow movement.Consequently,they are widely used for protection against natural hazards such as landslides and mudslides.This study,based on the threedimensional DEM(Discrete Element Method),investigated the impact of different baffle positions on debris flow protection.Debris flow velocity and kinetic energy variations were studied through single-factor experiments.Suitable baffle positions were preliminarily selected by analyzing the influence of the first-row baffle position on the impact force and accumulation mass of debris flow.Subsequently,based on the selected baffle positions and four factors influencing the effectiveness of baffle protection(baffle position(P),baffle height(h),row spacing(Sr),and angle of transit area(α)),an orthogonal design was employed to further explore the optimal arrangement of baffles.The research results indicate that the use of a baffle structure could effectively slow down the motion velocity of debris flows and dissipate their energy.When the baffle is placed in the transit area,the impact force on the first-row baffle is greater than that when the baffle is placed in the deposition area.Similarly,when the baffle is placed in the transit area,the obstruction effect on debris flow mass is also greater than that when the baffle is placed in the deposition area.Through orthogonal experimental range analysis,when the impact on the first row of baffles is used as the evaluation criterion,the importance of each influencing factor is ranked asα>P>S_r>h.When the mass of debris flow behind the baffle is regarded as the evaluation criterion,the rank is changed to P>α>S_r>h.The experimental simulation results show that the optimal baffle arrangement is:P_5,S_r=16,α=35°,h=9.

Protective effects of peptide KSPLY derived from Hericium erinaceus on H_(2)O_(2)-induced oxidative damage in HepG2 cells

Reactive oxygen species(ROS)-induced oxidative damage is strongly associated with the pathogenesis of chronic diseases,and natural antioxidant peptides have good abilities of scavenging ROS.The antioxidant activity of peptide Lys-Ser-Pro-Leu-Tyr(KSPLY)derived from Hericium erinaceus remains unclear.In the present study,the antioxidant effect and mechanism of KSPLY on H_(2)O_(2)-induced oxidative damage in HepG2 cells were investigated.The results indicated that KSPLY exhibited the antioxidant capacity in H_(2)O_(2)-induced HepG2 cells by enhancing superoxide dismutase(SOD),glutathione peroxidase(GSH-Px),and catalase(CAT)activities.In comparison with the H_(2)O_(2)-treated damage group,the apoptosis rate,ROS level,and malondialdehyde(MDA)content of HepG2 cells treated with KSPLY were significantly decreased.The H.erinaceus-derived peptide KSPLY pretreatment promoted the expression of detoxification and antioxidant enzymes via the Keap1/Nrf2 signal pathway,thereby inhibiting the generation of ROS and MDA.In conclusion,the H.erinaceus-derived peptide KSPLY effectively protected HepG2 cells against H_(2)O_(2)-induced oxidative damage,and it provided a theoretical basis for the further development of new natural antioxidants.

Protective Effects of Ginsenoside Rb1 on Septic Rats and Its Mechanism

This study aims to observe the protective effects of ginsenoside Rbl on liver and lung in rats with septic shock and reveal its mechanism. Rats were randomly divided into three groups： sham, cecal ligation and puncture （CLP）, and CLP with ginsenoside Rb1. Then, the survival rate, arterial blood pressure, TLR4 mRNA, and TNF-α levels were determined. The liver and lung tissues were stained with hematoxylin-eosin （HE）. The overall survival rate of the Rb1 group was significantly higher than that of the CLP group. Mean arterial blood pressure went down in both the CLP and Rb1 groups after CLP, and there was a significant difference both in the sham and Rb1 groups when compared with the CLP group. The Rb1 treatment group had markedly lower TLR4 mRNA expression and TNF-a levels than the CLP group. In the CLP group, pathology showed swelling, degeneration, necrosis, and neutrophii infiltration in the liver and alveolar epithelial cells. However, in the Rb1 group, there was mild degeneration and slight neutrophil infiltration, but no obvious necrosis. Rb1 may improve the survival rate, ameliorate arterial blood pressure, and protect the liver and lung in septic shock rats by downregulating the expression of TLR4 mRNA and inhibiting the production of TNF-α.

Protective Effects of Shikonin on Brain Injury Induced by Carbon Ion Beam Irradiation in Mice

Radiation encephalopathy is the main complication of cranial radiotherapy. It can cause necrosis of brain tissue and cognitive dysfunction. Our previous work had proved that a natural antioxidant shikonin possessed protective effect on cerebral ischemic injury. Here we investigated the effects of shikonin on carbon ion beam induced radiation brain injury in mice. Pretreatment with shikonin significantly increased the SOD and CAT activities and the ratio of GSH/GSSG in mouse brain tissues compared with irradiated group （P〈0.01）, while obviously reduced the MDA and PCO contents and the RO$ levels derived from of the brain mitochondria.

Protective Effects of Calcium Antagonists on Cadmium-induced Toxicity in Rats

Protective effects of calcium antagonists, chlorpromazine (CPZ) and nimodepine (NI-MO), on cadmium-induced toxicity were investigated. After giving CdCl2 (0. 44mg Cd/kg,ip), CPZ (5mg/kg, ip) or NIMO (8mg/kg, po) were administered every day to Sprague-Dawley (S. D. ) rats for a week. Then, urinary N- acetyl-β-D- glucosaminidase (NAG ), uri -nary cadmium and bloocl cadmium were measured. The accumulation of cadmium in the kid-ney cortex, content of renal calmodulin, hemoglobin and the ultrastructural damage of proxi-mal convoluted tubules of rats were examined three weeks after the last administration. Re-sults indicated that the calcium antagonists partly protected against toxic effects induced bycadmium in different manners. These data provide further evidence for the new hypothesisthat the cross effect of cadmium and calcium in calmodulin regulated systems may be responsi-ble for the mechanism of cadmium intoxication. 'The results suggested that the calcium antag-onists could be a new and promising approach in the therapy of heavy metaLinduced diseases

Protective Effects of Dimethyl-4,4'-Dimethoxy-5,6,5',6'-Dimethylene Dioxybiphenyl-2,2'-Dicarboxylate on Damages of Isolated Rat Hepatocytes Induced by Carbon Tetrachloride and D-galactosamine

The protective effect of biphenyl dimethyl dicarboxylate (DDB) on chemically induced damages was studied in isolated suspended rat hepatocytes. The experimental results showed that DDB (200μg/106 cells) efficiently protected the hepatocytes against carbon tetrachloride (CC14 10 mrnol.L-1) and D-galactosamine (1 mmol.L-1) induced damages. Membranal lipid peroxidation (malondialdehyde, MDA formation) and glutamic pyruvic transaminase (GPT) release from the hepatocytes were markedly decreased. The damage of the cell surfaces of the hepatocytes were also reduced as seen under a scanning electron microscope (SEM). Pretreatment with DDB (300 mg-kg-1) orally ameliorated the reduction of liver glycogen and blood glucose caused by ip injection of D-galactosamine (800 mg-kg-1) in mice. When normal rats were given DDB 300 mg-kg-1 once daily for 10 d, the free ribosomal protein and RNA in the liver increased significantly. These results indicate that DDB is of beneficial effects on both damaged and normal hepatocytes.

Focusing on the protective effects of metallothionein-Ⅰ/Ⅱ in cerebral ischemia

Ischemic stroke is a leading cause of death and has a remarkable social and economical impact, which rises with the increasing age of the industrial population. Unfortunately, treatment strat- egies for cerebral ischemia still remain very limited. Acute reper- fusion therapies with either systemic thrombolysis using rt-PA （recombinant tissue plasminogen activator） or interventional recanalization procedures were shown to be highly effective. In addition, there is also a long-existing concept to modulate stroke-associated pathophysiological events such as exitotox- icity, peri-infarct depolarizations, apoptosis and inflammation （Dirnagl et al., 1999）.

Protective Effects of Certain Natural and Synthetic Complexans on the Toxicity of Chromium and Tin to a N_2-Fixing Cyanobacterium, Anabaena doliolum

The effects of chromium and tin on survival, growth, carbon fixation, nitrate reduction, ammonia assimilation, and nitrogenase activity of a N_2-fixing cyanobacterium, Anabaena doliolum, and their amelioration by synthetic and natural complexans, viz., EDTA, nitrilotriacetic acid (NTA), pyridine dicarboxylic acid (PDA), and citrate, have been studied. Chromium proved to be much more toxic than tin, as it inhibited growth yield (49%), carbon fixation (53%), and nitrate reductase (79%), glutamine synthetase (30%), and nitrogenase activities (77%) at its sublethal concentration, whereas tin induced less inhibition of growth yield (42%), carbon fixation (50%). and nitrate reductase (66%), glutamine synthetase (32.4%), and nitrogenase activities (70%). Despite its inhibitory effects at 10μml^(-1), EDTA supplementation in metal-spiked medium counteracted the toxicity of chromium and tin more significantly than NTA, PDA, and citrate. When supplemented with LD_(50) of Cr, EDTA protected growth, carbon fixation, NR, GS. and Noase, respectively, by 32.6, 50.0, 33.3. 17.7. and 65.4%. However, EDTA-induced restoration of the above parameters at a sublethal concentration of tin was only 30.2, 50.0,28.1, 27.7, and 61.5%, respectively. Although NTA and citrate at 10/μgml^(-1) each were stimulatory to various processes of test cyanobacterium, they were comparatively less effective than EDTA in the amelioration of metal toxicity. On the basis of these observations, a generalized hierarchical sequence of protective efficiency of synthetic and natural cornplexing ligands may be given as EDTA > NTA > citrate > PDA. It seems plausible that the toxicity of various heavy metals may be regulated by a large array of organic complexing agents of the aquatic environment because they possess various metal binding sites. (c) 1989 Academic Press,lnc.

Protective effects of sodium ferulate in vascular endothelial function during cardiopulmonary bypass

Objective Cardiopulmonary bypass (CPB) and its related ischemia reperfusion injury may cause endothelial cell injury. To study the protective effects of sodium ferulate in vascular endothelial function during CPB by testing the changes of vascular endothelial cell(CEC) ,nitric oxide(NO) and endothelin-1 (ET-1) in children with congenital heart disease. Methods Sixty patients

Protective effects of blueberry anthocyanin extracts on hippocampal neuron damage induced by extremely low-frequency electromagnetic field

The protective effects of blueberry anthocyanin extracts against damage induced by extremely lowfrequency electromagnetic field(ELF-EMF)were investigated in a rat model.Wistar rats were exposed to ELF-EMF with or without the administration of blueberry anthocyanin extracts(50,100,and 200 mg/kg per day intragastrically once a day)for 30 days.Blueberry anthocyanin extracts supplementation inhibited the decrease in Nissl substance levels,cell membrane integrity,and mitochondrial membrane potential induced by ELF-EMF;prevented the increase in nitric oxide,malondialdehyde,and Ca2+concentrations;suppressed superoxide dismutase and glutathione depletion;and enhanced the cognitive ability of the rats exposed to ELF-EMF.The protective effects of blueberry anthocyanin extracts against hippocampal neuron injury caused by ELF-EMF were dose-dependent.These results demonstrated that blueberry anthocyanin extracts suppress hippocampal neuron injury caused by ELF-EMF by inhibiting cell membrane damage and oxidative stress pathways,and suggested that blueberry anthocyanin treatment potentially prevents hippocampal neuron injury.

Hepatic Protective Effects of <i>S</i>-Allyl-L-Cysteine (SAC) in Rats with Carbon Tetrachloride (CCl₄) Induced Liver Injury

S-allyl-L-cysteine (SAC) is an organosulfur compound derived from aged garlic extract (AGE). Studies have reported that AGE possesses bioprotective capacity, including antidiabetic, antimicrobial, antioxidant, and antitumor effects. The present study examined the protective effects of SAC against carbon tetrachloride (CCl4) induced hepatotoxicity in rats. Ten male Wistar rats aged 11 - 12 weeks were randomly divided into two groups (five rats/group) as control and SAC groups. All rats had ad libitum access to water, and the SAC group received water containing SAC intragastrically (200 mg/kg) once daily for five consecutive weeks. In the fifth experimental week, 50% CCl4 in olive oil (1 mL/kg) was administered intraperitoneally three times a week to induce liver injury in both groups. Rats were sacrificed at 24 hours after the last CCl4 injection, and liver tissues were excised for histopathological, immunohistochemical and antioxidant analyses. The rats in the SAC group did not show abnormal behavior, such as decreased water intake or food consumption, during the experimental period. Body weights in all groups did not change significantly over the experimental period. Histopathological analysis showed that the percentage of hepatic steatosis was lower in the SAC group at 12.75% ± 3.74% compared to 24.64% ± 5.29% in the control group (p < 0.05). The percentage of cytochrome P4502E1 (CYP2E1) distribution area in the SAC group was also lower at 19.61% ± 6.18% compared with 25.22% ± 6.21% in the control group (p < 0.05). These results suggest that SAC can alleviate CCl4-induced liver damage by decreasing hepatic steatosis and reducing CYP2E1 expression in rats.

Late Protective Effects of the Anticalmodulin Drug Fluphenazine on Carbon Tetrachloride-induced Liver Necrosis

Fluphenazine (FP) treatment (50mg/kg bw, ip in saline) 30 min before or 6 or 10 h after CCl4 administration (1 ml/kg ip in olive oil) significantly prevented the liver necrosis produced by the hepatotoxin at 24 h. FP had enhancing effects on the covalent binding of CCl4 reactive metabolites to cellular constituents and on CCl4 induced lipid peroaldation.FP lowered bOdy temperature of the CCl4-poisoned animals during the 24 h observation period. The obtained results are compatible but do not prove the hypothesis that calmodulin (CaM) had participation in late occurring events preceding necrosis. FP lowering action on body temperature, however, might also play a role in the effects of this drug on the onset of CCl4 induced liver necrosis. FP levels in liver tissue as determined by gas chromatography-mass spectrometry evidenced the presence of the drug in amounts suffi cient to inhibit CaM and that suggests that not all preventive effects of FP are due to its indirect actions on the central nervous system via decreased body temperature

Protective effects of levosimendan and ulinastain on the isolated rabbit heart

Objective Levosimendan,a new calcium ion sensitizer,is currently used in the treatment of heart failure and as an option for patients with injury to the left heart or at high risk for surgery. The study tried to evaluate the effects of levosimendan and ulinastain for protecting myocardium from ischemia-reperfusion (I / R) injury to

Protective effects of human umbilical cord mesenchymal stem cell vein transplantation against spinal cord ischemia/reperfusion injury in rats

BACKGROUND： The majority of studies addressing spinal cord ischemia/reperfusion injury （SCIRI） have focused on drugs, proteins, cytokines, and various surgical techniques. A recent study reports that human umbilical cord mesenchymal stem cell （hUCMSC） transplantation achieves good therapeutic effects, but the mechanisms underlying nerve protection remain poorly understood. OBJECTIVE： To observe survival of transplanted hUCMSCs in SCIRI rat models and the influence on motor function in the hind limbs, to determine interleukin-8 expression and cellular apoptosis in spinal cord tissues, and to verify the hypothesis that hUCMSC transplantation exhibits protective effects on SCIRI. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the Laboratory of the Department of Orthopedics in the First Affiliated Hospital of Soochow University, China between January 2007 and December 2008. MATERIALS： hUCMSCs were harvested from umbilical cord blood of healthy pregnant women after parturition in the Obstetrical Department of the First Affiliated Hospital of Soochow University, China. Rabbit anti-human BrdU monoclonal antibody was provided by DAKO, USA. Terminal deoxynucleotidyl transferase dUTP nick end labeling （TUNEL） Kit and enzyme-linked immunosorbent assay （ELISA） Kit were purchased by Wuhan Boster, China. METHODS： A total of 72 healthy, Wistar, adult rats were randomly assigned to three groups： sham-surgery, model, and transplantation, with 24 rats in each group. SCIRI was induced in the model and transplantation groups via the abdominal aorta block method. The infrarenal abdominal aorta was not blocked in the sham-surgery group. Prior to abdominal aorta occlusion, 0.2 03 mL bromodeoxyuridine （BrdU）-Iabeled hUCMSCs suspension （cell concentration 5 × 10 3/uL） was injected through the great saphenous vein of the hind limb, and an equal volume of physiological saline was administered to the model and sham-surgery groups. MAIN OUTCOME MEASURES： Pathological observation of rat spinal cord tissues was performed by hematoxylin-eosin staining at 6, 24, and 48 hours post-surgery. Immunohistochemistry was applied to determine hUCMSCs survival in the spinal cord. The amount of cellular apoptosis and interleukin-8 expression in spinal cord tissues was assayed utilizing the TUNEL and ELISA methods, respectively. Motor function in the hind limbs was evaluated according to Jacob＇s score. RESULTS： Numerous BrdU-positive cells were observed in spinal cord tissues from the transplantation group. The number of apoptotic cells and interleukin-8 levels significantly decreased in the transplantation group （P 〈 0.05）, pathological injury was significantly ameliorated, and motor function scores significantly increased （P 〈 0.05） compared with the model group. CONCLUSION： Via vein transplantation, hUCMSCs were shown to reach and survive in the injury area. Results suggested that the transplanted hUCMSCs contributed to significantly improved pathological changes in the injured spinal cord, as well as motor function, following SCIRI. The protective mechanism correlated with inhibition of cellular apoptosis and reduced production of inflammatory mediators.

Aeolian Activities and Protective Effects of Artificial Plants in Re-vegetated Sandy Land of Qinghai Lake,China

Land desertification and aeolian activity are currently the greatest threats to alpine ecological environments and are also the primary challenges of desertification control and ecological restoration projects.Afforestation of sandy lands around the Qinghai Lake in China has effectively controlled the desertification of this watershed.However,certain issues remain which challenge its overall success,including lack of diverse biological species and poor theoretical understanding of aeolian processes,such as controlling wind-sand flow in relation to complex alpine ecological factors.Therefore,to help improving afforestation techniques,this research focused on Hippophae rhamnoides,Salix cheilophila,Pinus sylvestris,Populus simonii and Artemisia desertorum vegetation implanted in the mobile dunes on the eastern shore of Qinghai Lake.Aeolian transport characteristics and annual changes to community ecological factors from 2010–2016 were monitored in comparison with uncontrolled sand dunes.Based on simultaneous observations using gradient anemometers and sand samplers,it was found that the aeolian activities exhibited the following features:1)In re-vegetated lands,the logarithmic growth of wind speed was disrupted by the wind speed amplification in the middle and high layers and wind speed reduction in the low layers,while vegetation had significant wind-breaking(>37%)and sand-fixing(>85%)effects in 2016.2)Wind speeds in re-vegetated lands and mobile dunes showed a linear correlation,especially in lower layers of H.rhamnoides and S.cheilophila,while sand transport in re-vegetated land increased linearly or exponentially with increasing wind speed.3)The four artificial shrubs and forests had greater sand deposition with intensities of 280–860 t/(ha·yr),largely concentrated during winter and spring which accounted for 60%–85%of the annual cycle,while A.desertorum experienced significant root undercutting;and 4)Intensity of aeolian activity in re-vegetated lands,except for A.desertorum,was significantly negative with respect to plant growth structure,community cover,topsoil moisture,and regional precipitation.Overall,these five sand-binding species produced optimistic wind-sand protection effects for the alpine sandy lands,which relied on the plants’physical disturbance of wind-sand flow during the early stages of community development.In comparison,H.rhamnoides and S.cheilophila individually maintained stable wind-sand protection effects,while P.sylvestris and P.simonii were better in mixing with other shrubs and herbs to achieve a comprehensive ecological system for future control of aeolian activity.

Protective Effects of Common Masks against PM2.5

By using two PM2.5 automatic monitors,the protective effects of five common masks against PM2.5 were synchronously tested under actual ambient air conditions for a whole day. The results showed that not all masks had protective effects on PM2.5,and the protective effects of masks N95 and N90,which were designed specially for dust-proof,were superior among the five tested masks.

Acute Toxicity of Jinchuan Formula Plum Wine Extract and Its Protective Effect on Mice with Liver Injury

[Objectives]To investigate the acute toxicity and hepatoprotective effect of Jinchuan formula plum wine extract on mice,determine its safety range,and evaluate its hepatoprotective effect.[Methods]The median lethal dose(LD_(50))was determined by acute toxicity test with the toxic reaction and mortality of mice as indexes.Sixty Kunming mice were randomly divided into 6 groups:normal control group,model group(ConA-induced liver injury model),Jinchuan formula plum wine high,medium and low dose groups(1.0,0.5,0.25 g/kg)and silybin group(0.1 g/kg).The levels of ALT,AST,LDH in serum and TG,VLDL in liver were measured.After HE staining,the pathological changes of liver tissue in mice were observed,and the liver protective effect of Jinchuan formula plum wine extract was analyzed and evaluated.[Results]LD_(50)was 11.18 g/kg,and the 95%confidence limit of LD_(50)was 10.31-12.05 g/kg.The high-dose group of Jinchuan formula plum wine extract could significantly reduce the serum ALT and AST activities of ConA-induced liver injury mice(P<0.05).[Conclusions]Jinchuan formula plum wine extract is relatively safe,and also has a protective effect on liver injury.

Protective Effects of Hydroxysafflor Yellow A against Oxidative Damage of β-Mercaptoethanol During Neural Differentiation of Mesenchymal Stem Cells

Objective To study the protective effects of hydroxysafflor yellow A （HSYA） against the oxidative damage caused by β-mercaptoethanol （BME） during neural differentiation of mesenchymal stem cells （MSCs） in vitro. Methods When the confluence reached 50%-60%, 4th passage MSCs were divided into three groups to culture. Gt ： normal group which was cultured using basic medium （DMEM containing 10% FBS all the time）; G2： unprotected group which was continuously cultured using basic medium for 24 h, and then cultured using pre-induction medium （DMEM containing 10% FBS and 1 mmol/L BME）; G3： protected group which was firstly cultured using protective medium （DMEM containing 10% FBS and 160 mg/L HSYA） for 24 h, and then cultured using pre-induction medium for 24 h. After these treatments as above, cell viability, relative levels of SOD/GSH and apoptosis rate were respectively detected. The expression of Bcl and Bax was examined by Western blotting. After HSYA protection and BME pre-induction, neural induction was performed. The expression of NSE and MAP-2 was respectively analyzed on cellular and molecular levels. Results Compared with unprotected group, 160 mg/L HSYA could obviously improve cells viability, maintain high level of SOD and GSH in MSCs, reduce apoptosis rate and improve the ratio of Bcl/Bax. After protection with 160 mg/L HSYA, the survival time of neuron-like cells could be extended. Immunocytochemical staining showed that after 10 h of neural induction, the differentiated neuron-like cells in protected group were still in a good state, and the mRNA levels of NSE and MAP-2 were increased during the induction course checked. Conclusion HSYA could improve the resistance of cells to the oxidative damage caused by BME.

Synergetic protective effects of combined blockade by two kinds of autolesion mediator receptor on neurological function after cervical cord injury

Abstract Objective To investigate the effects of combined blockade by platelet activating factor (PAF) receptor antagonist BN 52021 in combination with opiate receptor antagonist naloxone on neurological function and neurological tissue damage after cervical cord injury. Methods Spinal cord contusion at C 6 segment was made with Allen method in cats, which were randomly divided into four groups: saline control group; BN 52021 group; naloxone group; and combined treatment group with BN 52021 and naloxone. Alteration of cervical cord blood flow, blood barrier permeability of the spinal cord, cervical cord tissue pathology and neurological functional scores were studied after experimental cervical cord injury. Results The animals treated with BN 52021 or naloxone had significantly better functional scores than saline controls 6 weeks after injury (P<0.05). Moreover, the combined treatment showed significantly better neurologic recovery than either naloxone or BN 52021 treated animals (P<0.05). The other indexes in combined treatment animals were also superior to those in naloxone or BN 52021 treated animals. Conclusions Combined blockade by two kinds of autolesion mediator receptor can more effectively inhibit secondary damage production and development after cervical cord injury and improve neurologic function.