Comparison between sepsis-induced coagulopathy and sepsis-associated coagulopathy criteria in identifying sepsis-associated disseminated intravascular coagulation

BACKGROUND:Disseminated intravascular coagulation(DIC)is associated with increased mortality in sepsis patients.In this study,we aimed to assess the clinical ability of sepsis-induced coagulopathy(SIC)and sepsis-associated coagulopathy(SAC)criteria in identifying overt-DIC and preDIC status in sepsis patients.METHODS:Data from 419 sepsis patients were retrospectively collected from July 2018 to December 2022.The performances of the SIC and SAC were assessed to identify overt-DIC on days 1,3,7,or 14.The SIC status or SIC score on day 1,the SAC status or SAC score on day 1,and the sum of the SIC or SAC scores on days 1 and 3 were compared in terms of their ability to identify pre-DIC.The SIC or SAC status on day 1 was evaluated as a pre-DIC indicator for anticoagulant initiation.RESULTS:On day 1,the incidences of coagulopathy according to overt-DIC,SIC and SAC criteria were 11.7%,22.0%and 31.5%,respectively.The specificity of SIC for identifying overt-DIC was significantly higher than that of the SAC criteria from day 1 to day 14(P<0.05).On day 1,the SIC score with a cut-off value>3 had a significantly higher sensitivity(72.00%)and area under the curve(AUC)(0.69)in identifying pre-DIC than did the SIC or SAC status(sensitivity:SIC status 44.00%,SAC status 52.00%;AUC:SIC status 0.62,SAC status 0.61).The sum of the SIC scores on days 1 and 3 had a higher AUC value for identifying the pre-DIC state than that of SAC(0.79 vs.0.69,P<0.001).Favorable effects of anticoagulant therapy were observed in SIC(adjusted hazard ratio[HR]=0.216,95%confidence interval[95%CI]:0.060–0.783,P=0.018)and SAC(adjusted HR=0.146,95%CI:0.041–0.513,P=0.003).CONCLUSION:The SIC and SAC seem to be valuable for predicting overt-DIC.The sum of SIC scores on days 1 and 3 has the potential to help identify pre-DIC.

Effects of Coagulation and Ozonation Pretreatments on Biochemical Treatment of Fluid Catalytic Cracking Wastewater

Fluid catalytic cracking (FCC) salty wastewaters, containing quaternary ammonium compounds (QACs), are very difficult to treat by biochemical process. Anoxic/oxic (A/O) biochemical system, based on nitrification and denitrification reactions, was used to assess their possible biodegradation. Because of the negative effects of high salt concentration (3%), heavy metals and toxic organic matter on microorganisms’ activities, some techniques consisting of dilution, coagulation and flocculation, and ozonation pretreatments, were gradually tested to evaluate chemical oxygen demand (COD), ammonia-nitrogen (ammonia-N) and total nitrogen (TN) removal rates. In this process of FCC wastewater, starting with university-domesticated sludge, the ammonia-N and TN removal rates were worst. However, when using domesticated SBR’s sludge and operating with five-fold daily diluted influent (thus reducing salt concentration), the ammonia-N removal reached about 57% while the TN removal rate was less than 37% meaning an amelioration of the nitrification process. However, by reducing the dilution factors, these results were inflected after some days of operation, with ammonia-N removal decreasing and TN barely removed meaning a poor nitrification. Even by reducing heavy metals concentration with coagulation/flocculation process, the results never changed. Thereafter, by using ozonation pre-treatment to degrade the detected organic matter of di-tert-butylphenol and certain isoparaffins, COD, ammonia-N and TN removal rates reached 92%, 62% and 61%, respectively. These results showed that the activities of the microorganisms were increased, thus indicating a net denitrification and nitrification reactions improvement.

Coagulation abnormalities and their relationship with bleeding manifestations in patients with dengue-A single center observational study

Objective:To evaluate coagulation abnormalities and their relationship with bleeding manifestations among patients with dengue.Methods:This observational study was conducted on 292 adult dengue patients who were admitted to a tertiary care hospital of Western India from July 2021 to June 2022.Coagulation tests including prothrombin time(PT),international normalized ratio(INR),activated partial thromboplastin time(aPTT),fibrinogen,and D-dimer were performed.Patients were monitored for bleeding manifestations.Results:Coagulation abnormalities were reported in 42.8%of the patients.Overall,prolonged aPTT was the most common coagulation abnormality(40.8%),followed by low fibrinogen(38.7%),raised D-dimer(31.2%),raised INR(26.0%)and prolonged PT(19.2%).Bleeding manifestations were present in 19.9%patients.PT,INR,aPTT and D-dimer levels were significantly higher(P<0.01)and fibrinogen level was significantly lower(P<0.001)in patients with bleeding compared to patients without bleeding.Patients with bleeding had a significantly higher rate of all coagulation abnormalities than patients without bleeding(P<0.01).Conclusions:Patients with bleeding showed a significantly higher frequency of coagulation abnormalities compared to patients without bleeding.Patients with dengue should be assessed for coagulation abnormalities.

Perioperative coagulation activation after permanent pacemaker placement

BACKGROUND Bradyarrhythmias are typically treated with permanent pacemakers(PM). The elimination of bradyarrhythmia by PM implantation improves the patient’s quality of life and prognosis, but it can also result in a number of sequalae. It is still unclear how PM implantation affects the hemostasis system’s parameters and how such parameters relate to different consequences after PM placement.AIM To assess the blood coagulation factor activity in PM patients throughout the perioperative period.METHODS Patients treated in the Department of Surgical Therapy of Cardiac Arrhythmias and Pacing at the Ryazan State "Regional Clinical Cardiology Dispensary" from April 2020 to December 2021 were included in the study. Before surgery, 7 and 30 d after PM placement, peripheral venous blood samples were withdrawn to measure the level of blood coagulation factor Ⅰ(FⅠ) and the activity of blood coagulation factors Ⅱ(FⅡ), Ⅴ(FⅤ), Ⅶ(FⅦ), Ⅷ(FⅧ), ⅸ(Fⅸ), ⅹ(Fⅹ), Ⅺ(FⅪ), Ⅻ(FⅫ). We used an automatic coagulometer Sysmex CA 660(Sysmex Europe, Germany) and reagents from Siemens(Siemens Healthcare Diagnostics Products GmbH, Germany).RESULTS The study included 146 patients. The activity of factors FⅤ [147.7(102.1-247.55)% vs 103.85(60-161.6)% vs 81.8(67.15-130.65)%, P = 0.002], FⅧ [80.4(60.15-106.25)% vs 70.3(48.5-89.1)% vs 63.7(41.6-88.25)%, P = 0.039], Fⅸ [86.2(70.75-102.95)% vs 75.4(59.2-88.3)% vs 73.9(56.45-93.05)%, P = 0.014], Fⅹ [188.9(99.3-308.18)% vs 158.9(83.3-230)% vs 127.2(95.25-209.35)%, P = 0.022], FⅪ [82.6(63.9-103.6)% vs 69.75(53.8-97.6)% vs 67.3(54.25-98.05)%, P = 0.002], FⅫ [87.6(67.15-102.3)% vs 78.9(63.4-97.05)% vs 81.2(62.15-97.4)%, P < 0.001] decreased at 7 and 30 d after surgery;FⅡ activity [157.9(109.7-245.25)% vs 130(86.8-192.5)% vs 144.8(103.31-185.6)%, P = 0.021] decreased at 7 d and increased at 30 d postoperatively. There were no statistically significant changes in the FVII activity within 30 d after PM placement [182.2(85.1-344.8)% vs 157.2(99.1-259)% vs 108.9(74.9-219.8)%, P = 0.128]. Subgroup analysis revealed similar changes only in patients on anticoagulant therapy. FⅫ activity decreased in patients on antiplatelet therapy [82(65.8-101.9)% vs 79.9(63.3-97.1)% vs 89.7(75.7-102.5)%, P = 0.01] 7 d after surgery, returning to baseline values at 30 d postoperatively.CONCLUSION PM placement and anticoagulant therapy were associated with decreased activity of clotting factors FⅤ, FⅧ, Fⅸ, Fⅹ, FⅪ, FⅫ in the postoperative period. FⅧ activity did not decrease within 30 d after PM placement, which may indicate endothelial injury caused by lead placement.

Clinical association between coagulation indicators and bone metastasis in patients with gastric cancer

BACKGROUND Bones are one of the most common target organs for cancer metastasis.Early evaluation of bone metastasis(BM)status is clinically significant.Cancer patients often experience a hypercoagulable state.AIM To evaluate the correlation between coagulation indicators and the burden of BM in gastric cancer(GC).METHODS We conducted a single-center retrospective study and enrolled 454 patients.Clinical information including routine blood examination and coagulation markers were collected before any treatment.Patients were grouped according to the status of BM.Receiver operating characteristic curves were used to assess diagnostic performance and determine the optimal cutoff values of the above indicators.Cutoff values,sensitivity and specificity were based on the maximum Youden index.Univariate and multivariate logistic regression analyses were used to evaluate the relationships between biomarkers and BM.RESULTS Of the 454 enrolled patients,191 patients were diagnosed with BM.The receiver operating characteristic curve analysis suggested that prothrombin time(PT)Wang X et al.Coagulation indicators predict bone metastasis WJGO https://www.wjgnet.com 1254 July 15,2023 Volume 15 Issue 7[cutoff:13.25;sensitivity:0.651;specificity:0.709;area under receiver operating characteristic curve(AUC)=0.738],activated partial thromboplastin time(aPTT)(cutoff:35.15;sensitivity:0.640;specificity:0.640;AUC=0.678)and fibrin degradation products(FDP)(cutoff:2.75;sensitivity:0.668;specificity:0.801;AUC=0.768)act as novel predictors for BM.Based on multivariate logistic regression analysis,the results showed the independent correlation between PT[odds ratio(OR):3.16;95%confidence interval(CI):1.612-6.194;P=0.001],aPTT(OR:2.234;95%CI:1.157-4.313;P=0.017)and FDP(OR:3.17;95%CI:1.637-6.139;P=0.001)and BM in patients with GC.Moreover,age,carcinoembryonic antigen,erythrocyte and globulin were found to be significantly associated with BM.CONCLUSION Coagulation markers,namely PT,aPTT and FDP,might be potential predictors for screening BM in patients with GC.

Expression and Purification of Human Coagulation Factor X in Mammalian CHO-DG44 Cells

[Objectives]This study was conducted to obtain a Chinese hamster ovary cell line that stably expresses recombinant human coagulation factor X(rhFX),and to induce efficient expression of the target gene with different concentrations of methotrexate(MTX).[Methods]PCR was performed to obtain the rhFX gene,and a recombinant expression plasmid pOptiVEC-rhFX was constructed and subjected to double restriction endonuclease digestion and sequencing identification.CHO-DG44(DHFR-)cells were transfected by the liposome method,and the target protein was purified by affinity chromatography and detected by SDS-PAGE electrophoresis and Western blot.A cell line with efficient and stable expression of the target gene was obtained by increasing the concentration of MTX to select positive clones.[Results]PCR yielded a 1509 bp rhFX sequence,and the results of double digestion and sequencing showed that the constructed pOptiVEC-rhFX plasmid was correct.After transfection of cells,MTX significantly increased protein expression.When MTX reached 1.0μmol/L,the expression efficiency of the target protein was(9±0.27)μg/ml.The purity of the target protein purified by affinity chromatography was 93%,which could be used for subsequent experiments.The expression efficiency of rhFX in eukaryotic mammalian cells was improved by increasing MTX concentration,and an affinity chromatography purification process for the target protein was preliminarily established.[Conclusions]The results of this study provide data support for the expression and purification of rhFX,and will lay a solid foundation for the development of drugs related to rhFX.

Investigating the Performance of the Coagulation Process When Using a Combination of Zinc Oxide Nanoparticles and Ferric Polysulfate

In this article, a new type of coagulant material has been investigated and the performance of the coagulation process using this type of coagulant was evaluated. This new type is a combination of zinc oxide nanoparticles and polyferric sulfate (ZnOPFS). The structure of zinc oxide nanoparticles was determined by spectroscopic, X-ray and electron microscopy methods, and based on this, it was determined that ZnOPFS is a complex and mixed compound that is mainly composed of zinc oxide nanoparticles and ferric sulfate. The effects of Zn/Fe (Zn/Fe) molar ratio and aging (time) on acidity and zeta potential were also evaluated using a specific method. The obtained results showed that in the simultaneous deposition process, zinc ions can prevent the formation of polyferric acid coagulation and subsequently improve the stability of ZnOPFS.

Virus Removal by Iron Coagulation Processes

Waterborne viruses account for 30% to 40% of infectious diarrhea, and some viruses could persevere for some months in nature and move up to 100 m in groundwater. Using filtration setups, coagulation could lessen virus charges as an efficient pre-treatment for reducing viruses. This work discusses the present-day studies on virus mitigation using coagulation in its three versions i.e., chemical coagulation (CC), enhanced coagulation, and electrocoagulation (EC), and debates the new results of virus demobilization. The complexity of viruses as bioparticles and the process of virus demobilization should be adopted, even if the contribution of permeability in virus sorption and aggregation needs to be clarified. The information about virion permeability has been evaluated by interpreting empirical electrophoretic mobility (EM). No practical measures of virion permeability exist, a clear link between permeability and virion composition and morphology has not been advanced, and the direct influence of inner virion structures on surface charge or sorption has yet to be conclusively demonstrated. CC setups utilizing zero-valent or ferrous iron could be killed by iron oxidation, possibly using EC and electrooxidation (EO) methods. The oxidants evolution in the iron oxidation method has depicted promising findings in demobilizing bacteriophage MS2, even if follow-up investigations employing an elution method are needed to secure that bacteriophage elimination is related to demobilization rather than sorption. As a perspective, we could be apt to anticipate virus conduct and determine new bacteriophage surrogates following subtle aspects such as protein structures or genome size and conformation. The present discussion’s advantages would extend far beyond an application in CC—from filtration setups to demobilization by nanoparticles to modeling virus fate and persistence in nature.

In silico evidence of Remdesivir action in blood coagulation cascade modulation in COVID-19 treatment

BACKGROUND Coronavirus disease 2019(COVID-19)has demonstrated several clinical manifestations which include not only respiratory system issues but also liver,kidney,and other organ injuries.One of these abnormalities is coagulopathies,including thrombosis and disseminated intravascular coagulation.Because of this,the administration of low molecular weight heparin is required for patients that need to be hospitalized.In addition,Remdesivir is an antiviral that was used against Middle East Acute Respiratory Syndrome,Ebola,Acute Respiratory Syndrome,and other diseases,showing satisfactory results on recovery.Besides,there is evidence suggesting that this medication can provide a better prognosis for patients with COVID-19.AIM To investigate in silico the interaction between Remdesivir and clotting factors,pursuing a possibility of using it as medicine.METHODS In this in silico study,the 3D structures of angiotensin-converting enzyme 2(ACE2),Factor I(fibrinogen),Factor II(prothrombin),Factor III(thromboplastin),Factor V(proaccelerin),Factor VII(proconvertin),Factor VIII(antihemophilic factor A),Factor IX(antihemophilic factor B),Factor X(Stuart-Prower factor),and Factor XI(precursor of thromboplastin(these structures are technically called receptors)were selected from the Protein Data Bank.The structures of the antivirals Remdesivir and Osetalmivir(these structures are called ligands)were selected from the PubChem database,while the structure of Atazanavir was selected from the ZINC database.The software AutoDock Tools(ADT)was used to prepare the receptors for molecular docking.Ions,peptides,water molecules,and other ones were removed from each ligand,and then,hydrogen atoms were added to the structures.The grid box was delimited and calculated using the same software ADT.A physiological environment with pH 7.4 is needed to make the ligands interact with the receptors,and still the software Marvin sketch®(ChemAxon®)was used to forecast the protonation state.To perform molecular docking,ADT and Vina software was connected.Using PyMol®software and Discovery studio®software from BIOVIA,it was possible to analyze the amino acid residues from receptors that were involved in the interactions with the ligands.Ligand tortions,atoms that participated in the interactions,and the type,strength,and duration of the interactions were also analyzed using those software.RESULTS Molecular docking analysis showed that Remdesivir and ACE2 had an affinity energy of-8.8 kcal/moL,forming a complex with eight hydrogen bonds involving seven atoms of Remdesivir and five amino acid residues of ACE2.Remdesivir and prothrombin had an interaction with six hydrogen bonds involving atoms of the drug and five amino acid residues of the clotting factor.Similar to that,Remdesivir and thromboplastin presented interactions via seven hydrogen bonds involving five atoms of the drug and four residues of the clotting factor.While Remdesivir and Factor V established a complex with seven hydrogen bonds between six antiviral atoms and six amino acid residues from the factor,and Factor VII connected with the drug by four hydrogen bonds,which involved three atoms of the drug and three residues of amino acids of the factor.The complex between Remdesivir and Factor IX formed an interaction via 11 hydrophilic bonds with seven atoms of the drug and seven residues of the clotting factor,plus one electrostatic bond and three hydrophobic interactions.Factor X and Remdesivir had an affinity energy of-9.6 kcal/moL,and the complex presented 10 hydrogen bonds and 14 different hydrophobic interactions which involved nine atoms of the drug and 16 amino acid residues of the clotting factor.The interaction between Remdesivir and Factor XI formed five hydrogen bonds involving five amino acid residues of the clotting factor and five of the antiviral atoms.CONCLUSION Because of the in silico significant affinity,Remdesivir possibly could act in the severe acute respiratory syndrome coronavirus 2 infection blockade by interacting with ACE2 and concomitantly act in the modulation of the coagulation cascade preventing the hypercoagulable state.

Coagulation and analgesic effects of aqueous extract of peanut shells on mice

Background:Peanut shells are a commonly discarded byproduct of peanut processing.However,recent studies have shown that they contain bioactive compounds that have potential health benefits.Specifically,water extract from peanut shells has been identified as a promising source of these compounds.Therefore,investigating the effects of water extract from peanut shells on coagulation and analgesia in mice could have significant implications for human health.Methods:(1)Analgesic experiments:The analgesic effect of the aqueous extract of peanut shells was observed by the hot plate method in mice.The aspirin group was used as a positive control group for analgesic experiments.(2)Coagulation experiment:the coagulation effect of the aqueous extract of peanut shells was observed by the capillary method and slide method.Yunnan Baiyao group was the positive control group of the coagulation test.Results:(1)The analgesic effect of peanut shell water extract on mice was prolonged with the increase in dose.The low,medium,and high dose groups of peanut shell could improve the pain domain of mice induced by the hot plate method in a certain period(P<0.05);with the increase of peanut shell water extract dose,liver weight coefficient increased(P<0.05).(2)Peanut shell water extract coagulated mice,and the high-dose group of peanut shells was the most significant.Within the scope of this study,the higher the concentration,the better the coagulation effect(P<0.05).Compared with distilled water group,the liver weight coefficients of the Yunnan Baiyao group,low,middle,and high dose groups of peanut shells were significantly increased(P<0.05).Conclusion:(1)The aqueous extract of peanut shells has a specific analgesic effect on mice.(2)The aqueous extract of peanut shells promotes coagulation,and the pro-coagulant effect is more significant with increasing dose and the liver weight coefficient increases.

Facile synthesis of composite polyferric magnesium-silicate-sulfate coagulant with enhanced performance in water and wastewater

The coagulation process is a widely applied technology in water and wastewater treatment.Novel composite polyferric mag-nesium-silicate-sulfate(PFMS)coagulants were synthesized using Na_(2)SiO_(3)·9H_(2)O,Fe_(2)(SO_(4))_(3),and MgSO_(4) as raw materials in this paper.The effects of aging time,Fe:Si:Mg,and OH:M molar ratios(M represents the metal ions)on the coagulation performance of the as-pre-pared PFMS were systematically investigated to obtain optimum coagulants.The results showed that PFMS coagulant exhibited good co-agulation properties in the treatment of simulated humic acid-kaolin surface water and reactive dye wastewater.When the molar ratio was controlled at Fe:Si:Mg=2:2:1 and OH:M=0.32,the obtained PFMS presented excellent stability and a high coagulation efficiency.The removal efficiency of ultraviolet UV254 was 99.81%,and the residual turbidity of the surface water reached 0.56 NTU at a dosage of 30 mg·L^(-1).After standing the coagulant for 120 d in the laboratory,the removal efficiency of UV254 and residual turbidity of the surface wa-ter were 88.12%and 0.68 NTU,respectively,which accord with the surface water treatment requirements.In addition,the coagulation performance in the treatment of reactive dye wastewater was greatly improved by combining the advantages of magnesium and iron salts.Compared with polyferric silicate-sulfate(PFS)and polymagnesium silicate-sulfate(PMS),the PFMS coagulant played a better decolor-ization role within the pH range of 7-13.

Concerns about the application of resistance exercise with blood-flow restriction and thrombosis risk in hemodialysis patients

Background:Hemodialysis(HD)per se is a risk factor for thrombosis.Considering the growing body of evidence on blood-flow restriction(BFR)exercise in HD patients,identification of possible risk factors related to the prothrombotic agent D-dimer is required for the safety and feasibility of this training model.The aim of the present study was to identify risk factors associated with higher D-dimer levels and to determine the acute effect of resistance exercise(RE)with BFR on this molecule.Methods:Two hundred and six HD patients volunteered for this study(all with a glomerular filtration rate of<15 mL/min/1.73 m^(2)).The RE+BFR session consisted of 50%arterial occlusion pressure during 50 min sessions of HD(intradialytic exercise).RE repetitions included concentric and eccentric lifting phases(each lasting 2 s)and were supervised by a strength and conditioning specialist.Results:Several variables were associated with elevated levels of D-dimer,including higher blood glucose,citrate use,recent cardiovascular events,recent intercurrents,higher inflammatory status,catheter as vascular access,older patients(>70 years old),and HD vintage.Furthermore,RE+BFR significantly increases D-dimer after 4 h.Patients with borderline baseline D-dimer levels(400-490 ng/mL)displayed increased risk of elevating D-dimer over the normal range(-500 ng/mL).Conclusion:These results identified factors associated with a heightened prothrombotic state and may assist in the screening process for HD patients who wish to undergo RE+BFR.D-dimer and/or other fibrinolysis factors should be assessed at baseline and throughout the protocol as a precautionary measure to maximize safety during RE+BFR.

Adverse events associated with the gold probe and the injection gold probe devices used for endoscopic hemostasis:A MAUDE database analysis

BACKGROUND Gastrointestinal(GI)bleeding accounts for over half a million admissions annually and is the most common GI diagnosis requiring hospitalization in the United States.Bipolar electrocoagulation devices are used for the management of gastrointestinal bleeding.There is no data on device-related adverse events for gold probe(GP)and injection gold probe(IGP).AIM To analyze this using the Food and Drug Administration(FDA’s)Manufacturer and User Facility Device Experience(MAUDE)database from 2013 to 2023.METHODS We examined post-marketing surveillance data on GP and IGP from the FDA MAUDE database to report devicerelated and patient-related adverse events between 2013-2023.The MAUDE database is a publicly available resource providing over 4 million records relating to medical device safety.Statistical analyses were performed using IBM SPSS Statistics V.27.0(IBM Corp.,Armonk,NY,United States).RESULTS Our search elicited 140 reports for GP and 202 reports for IGP,respec-tively,during the study period from January 2013 to August 2023.Malfunctions reportedly occurred in 130 cases for GP,and actual patient injury or event occurred in 10 patients.A total of 149 patients(74%)reported with Injection GP events suffered no significant consequences due to the device failure,but 53 patients(26%)were affected by an event.CONCLUSION GP and IGP are critical in managing gastrointestinal bleeding.This study of the FDA MAUDE database revealed the type,number,and trends of reported device-related adverse events.The endoscopist and support staff must be aware of these device-related events and be equipped to manage them if they occur.

Uremic Bleeding in 2 Patients with Dieulafoy’s Lesion: Case Report and Literature Review

Dieulafoy’s lesions are rare vascular malformations of the gastrointestinal tract. A Dieulafoy’s lesion is an aberrant vessel that does not reduce in caliber when it extends from the submucosa to the mucosa. Damage to this artery can cause severe and intermittent arterial bleeding from small vascular stumps that are difficult to visualize. Furthermore, these catastrophic bleeding episodes frequently result in hemodynamic instability and the need for transfusion of multiple blood products. Recently, uremic syndrome has been identified as a risk factor for gastric mucosal lesions. We present two clinical cases of acute digestive bleeding due to Dielafoy lesion with chronic kidney disease as the main cause, where two different therapies were performed endoscopically. We concluded with the results of our patients that the best therapy was the application of the hemostatic hemoclip on the injury vs the injection with adrenaline on the wound site. Uremia is identified as a risk factor for upper gastrointestinal bleeding in patients with pre-existing Dieulafoy’s lesion, as well as a higher incidence of new bleeding.

Effect of coagulation pretreatment on the fouling of ultrafiltration membrane

The purpose of this study is to understand the effect and mechanism of preventing membrane fouling, by coagulation pretreatment, in terms of fractional component and molecular weight of natural organic matter （NOM）. A relatively higher molecular weight （MW） of hydrophobic compounds was responsible for a rapid decline in the ultrafiltration flux. Coagulation could effectively remove the hydrophobic organics, resulting in the increase of flux. It was found that a lower MW of neutral hydrophilic compounds, which could remove inadequately by coagulation, was responsible for the slow declining flux. The fluxes in the filtration of coagulated water and supernatant water were compared and the results showed that a lower MW of neutral hydrophilic compounds remained in the supernatant water after coagulation could be rejected by a membrane, resulting in fouling. It was also found that the coagulated flocs could absorb neutral hydrophilic compounds effectively. Therefore, with the coagulated flocs formed on the membrane surface, the flux decline could be improved.

APPLICATION OF CLAYS TO REMOVAL OF RED TIDE ORGANISMS Ⅰ.COAGULATION OF RED TIDE ORGANISMS WITH CLAYS

Coagulation of red tide organism cells with clays is discussed in theory and the effects of some fac-tors on it are studied.A quantitative model is presented which describes how the coagulation varies withpH in solution.According to the model,within the pH-range between pHzpcaand pHzpcb,VR is negativeand the coagulation is strong and strongest at pH=(pHzpca+pHzpcb)/2.It is also demonstrated that whenthe diameter of clay particles is close to that of cells,the collision probability is low,resulting in weakercoagulation.The model results have been corroborated by experiments and so are scientific and theoreticalbases for application.

APPLICATION OF CLAYS TO REMOVAL OF RED TIDE ORGANISMS Ⅱ.COAGULATION OF DIFFERENT SPECIES OF RED TIDE ORGANISMS WITH MONTMORILLONITE AND EFFECT OF CLAY PRETREATMENT

Study on the coagulation of four species of red tide organisms（Nitzschia pungens,Skeletonema costatum,Prorocentrum minimum and Noctiluca scintillans）with montmorillonite,and the effect ofmontmorillonite pretreatment on the coagulation shows that the capability for montmorillonite to coagu-late with them is in the order:N.pungens】S.costatum】P.minimum】N.scintillans.Thecoagulation is discussed from the aspects of the structure,shape,size,movement,habit,etc.of differ-ent species and the results are explained theoretically.The experimental results also indicate that the treat-ment of montmorillonite with acid can enhance its coagulating capability.This is due to the fact that Al（OH2）6+3,exchanged from the clay lattice by hydrogen ion H+,forms hydroxy-aluminum polymers on thesurface of the montmorillonite.The hydroxy-aluminum polymers positively charge and increase the positivecharacteristic of the clay surface,and also serves as a bridge between adjacent surfaces of particles.Thesetwo functions

Transfusion and coagulation management in liver transplantation

There is wide variation in the management of coagulation and blood transfusion practice in liver transplantation.The use of blood products intraoperatively is declining and transfusion free transplantations take place ever more frequently.Allogenic blood products have been shown to increase morbidity and mortality.Primary haemostasis,coagulation and fibrinolysis are altered by liver disease.This,combined with intraoperative disturbances of coagulation,increases the risk of bleeding.Meanwhile,the rebalancing of coagulation homeostasis can put patients at risk of hypercoagulability and thrombosis.The application of the principles of patient blood management to transplantation can reduce the risk of transfusion.This includes:preoperative recognition and treatment of anaemia,reduction of perioperative blood loss and the use of restrictive haemoglobin based transfusion triggers.The use of point of care coagulation monitoring using whole blood viscoelastic testing provides a picture of the complete coagulation process by which to guide and direct coagulation management.Pharmacological methods to reduce blood loss include the use of anti-fibrinolytic drugs to reduce fibrinolysis,and rarely,the use of recombinant factorⅦa.Factor concentrates are increasingly used;fibrinogen concentrates to improve clot strength and stability,and prothrombin complex con-centrates to improve thrombin generation.Non-pharmacological methods to reduce blood loss include surgical utilisation of the piggyback technique and maintenance of a low central venous pressure.The use of intraoperative cell salvage and normovolaemic haemodilution reduces allogenic blood transfusion.Further research into methods of decreasing blood loss and alternatives to blood transfusion remains necessary to continue to improve outcomes after transplantation.

Large eddy simulation of a planar jet flow with nanoparticle coagulation

Coagulation and growth of nanoparticles subject to large coherent structures in a planar jet has been explored by using large eddy simulation. The particle field is obtained by employing a moment method to approximate the nanoparticle general dynamic equa- tion. An incompressible fluid containing particles of 1 nm in diameter is projected into a particle-free ambient. The results show that the coherent structures dominate the evolution of the nanoparticle number intensity, diameter and polydispersity distributions as the jet develops. In addition, the coherent structures act to increase the diffusion of particles, and the vortex rolling-up makes the particles distributing more irregularly while the vortex pairing causes particle distributions to become uniform. As the jet travels downstream, the time-averaged particle number concentration becomes lower in the jet core and higher in the outskirts, whereas the time- averaged particle mass over the entire flow field maintains unaltered, and the time-averaged particle diameter and geometric standard deviations grow and reach their maximum on the interface of the jet region and the ambient.

APPLICATION OF CLAYS TO REMOVAL OF RED TIDE ORGANISMS Ⅲ.THE COAGULATION OF KAOLIN ON RED TIDE ORGANISMS

This article reports studies on the coagulation of kaolin(from Wuxian,Jiangsu,China)on various red tide organisms,and the observation for the first time that the coagulation of kaolin is much greaterthan that of montmorillonite so that kaolin is a more effective clay for removing red tide organisms.The authors’theoretical explanation and analysis by a mathematical-physical model prove that comparedto montmorillonite,kaolin has greater attraction for organism cells and therefore greater coagulation capabil-ity.This project’s studies on the effects of pH and acid-treatment show that the acid-treatment does not have much influence on the kaolin system;whereas the effect of pH on the kaolin system is the same asthat on the montmonrillonite system.