Atomically dispersed Iridium on Mo2C as an efficient and stable alkaline hydrogen oxidation reaction catalyst.

Hydroxide exchange membrane fuel cells (HEMFCs) have the advantages of using cost-effective materials, but hindered by the sluggish anodic hydrogen oxidation reaction (HOR) kinetics. Here, we report an atomically dispersed Ir on Mo2C nanoparticles supported on carbon (IrSA-Mo2C/C) as highly active and stable HOR catalysts. The specific exchange current density of IrSA-Mo2C/C is 4.1 mA cm-2ECSA, which is 10 times that of Ir/C. Negligible decay is observed after 30,000-cycle accelerated stability test. Theoretical calculations suggest the high HOR activity is attributed to the unique Mo2C substrate, which makes the Ir sites with optimized H binding and also provides enhanced OH binding sites. By using a low loading (0.05 mgIr cm-2) of IrSA-Mo2C/C as anode, the fabricated HEMFC can deliver a high peak power density of 1.64 W cm-2. This work illustrates that atomically dispersed precious metal on carbides may be a promising strategy for high performance HEMFCs.

[Influence of Pre-treatment Lymphocyte/Monocyte Ratio and Neutrophil/Lymphocyte Ratio on the Prognosis of Patients with Extranodal NK/T-Cell Lymphoma].

OBJECTIVE: To explore the influence of lymphocyte-to-monocyte ratio (LMR) and neutrophil-to-lymphocyte ratio (NLR) on the prognosis of patients with extranodal NK/T cell lymphoma (ENKTL). METHODS: The clinical data of 203 patients with ENKTL admitted to the First Affiliated Hospital of Zhengzhou University from January 2011 to January 2020 were retrospectively analyzed. The ROC curve determined the limit values of LMR and NLR; Categorical variables were compared using a chi-square test, expressed as frequency and percentage (n,%). Continuous variables were expressed as medians and extremes and compared with the Mann-Whitney U test; Progression-free survival (PFS) and overall survival (OS) of different grouped LMR and NLR patients were analyzed using Kaplan-Meier curves and compared with log-rank tests. The COX proportional risk regression model was used to perform one-factor and multi-factor analysis of PFS and OS. RESULTS: The optimal critical values of LMR and NLR were determined by the ROC curve, which were 2.60 and 3.40, respectively. LMR≤2.60 was more likely to occur in patients with bone marrow invasion (P=0.029) and higher LDH (P=0.036), while NLR≥3.40 was more likely to occur in patients with higher ECOG scores (P=0.002), higher LDH (P=0.008), higher blood glucose (P=0.024), and lower PLT (P=0.010). Kaplan-Meier survival analysis showed that PFS and OS of patients in the high LMR group were significantly better than the low LMR group, while PFS and OS in the low NLR group were significantly better than the high NLR group. The results of multivariate COX analysis showed that EBV-DNA positive (P=0.047), LMR≤2.60 (P=0.014), NLR≥3.40 (P=0.023) were independent risk factors affecting PFS in patients with ENKTL. LMR≤2.60 (P<0.001), NLR≥3.40 (P=0.048), and high ß2-MG (P=0.013) were independent risk factors affecting OS in patients with ENKTL. CONCLUSION: Low LMR and high NLR before treatment are associated with poor prognosis in patients with ENKTL, which also can be used as an easily testable, inexpensive, and practical prognostic indicator in the clinic.

CircMAN1A2 contributes to nasopharyngeal carcinoma progression via enhancing the ubiquitination of ATMIN through miR-135a-3p/UBR5 axis.

Recently, the dysregulation of circRNAs has been increasingly implicated in the pathogenesis of nasopharyngeal carcinoma (NPC). Among these circRNAs, circMAN1A2 has been highlighted for the up-regulated expression in NPC, whereas the underlying mechanisms have not been clearly established. Thus, the aim of this study was to delineate the tumor-supporting role of circMAN1A2 in the oncogenesis and metastases of NPC. We validated through qRT-PCR that circMAN1A2 was highly expressed in NPC tissues and NPC cells. Survival analysis through Kaplan-Meier method showed that the overall survival, disease-free survival, and distant metastasis-free survival of patients was negatively correlated with the expression of circMAN1A2. Then, gain- and loss-of function assays demonstrated that circMAN1A2 knockdown could impede the proliferation, migration, invasion, and EMT in NPC cells. Further, we conducted dual luciferase reporter gene, RIP, and RNA pull down assays, unveiling that circMAN1A2 functioned as a sponge of miR-135a-3p, and miR-135a-3p targeted UBR5. Additionally, UBR5 interacted with ATMIN to foster the ubiquitination of ATMIN, thereby expediting the malignant behaviors of NPC cells as well as the lung and inguinal lymph node metastases of NPC tumors in vivo. Together, our study uncovered the tumor-initiating and pro-metastatic role of circMAN1A2-miR-135a-3p-UBR5-ATMIN axis in NPC regulation that may be a potential therapeutic target for human NPC.

Dual-Atom Metal and Nonmetal Site Catalyst on a Single Nickel Atom Supported on a Hybridized BCN Nanosheet for Electrochemical CO2 Reduction to Methane: Combining High Activity and Selectivity.

Atomically dispersed nitrogen-coordinated transition-metal sites supported on graphene (TM-N4-C) offer promising potential for the electrochemical carbon dioxide reduction reaction (CO2RR). However, a few TM-Nx-C single-atom catalysts (SAC) are capable of reducing CO2 to multielectron products with high activity and selectivity. Herein, using density functional theory calculations, we investigated the electrocatalytic performance of a single TM atom embedded into a defective BCN nanosheet for CO2RR. The N and B atom co-coordinated TM center, namely, TM-B2N2, constructs a symmetry-breaking site, which strengthens the overlapping of atomic orbitals, and enables the linear CO2 to be curved and activated, compared to the weak coupling of CO2 with the symmetric TM-N4 site. Moreover, the TM-B2N2 sites play a role of dual-atom active sites, in which the TM atom serves as the carbon adsorption site and the B atom acts as the oxygen adsorption site, largely stabilizing the key intermediates, especially *COOH. The symmetry-breaking coordination structures shift the d-band center of the TM atom toward the Fermi level and thus facilitate CO2 reduction to hydrocarbons and oxygenates. As a result, different from the TM-N4-C structure that leads to CO as the major product, the Ni atom supported on BCN can selectively catalyze CO2 conversion into CH4, with an ultralow limiting potential of -0.07 V, while suppressing the hydrogen evolution reaction. Our finding suggests that introduction of a nonmetal active site adjacent to the metal site provides a new avenue for achieving efficient multi-intermediate electrocatalytic reactions.

Carbon dots dominated photoelectric surface in titanium dioxide nanotube/nitrogen-doped carbon dot/gold nanocomposites for improved photoelectrochemical water splitting.

The dynamic behavior of electron-hole pairs at the interface of the nanocomposites is important for photoelectrochemical catalysis, but it is difficult to characterize. Here we construct a ternary titanium dioxide/nitrogen-doped carbon dot/gold (TiO2/NCD/Au) complex as the model catalyst to investigate the kinetic indexes at their interfaces. Under irradiation (200 mW cm-2), the photocurrent density of TiO2/NCD/Au is 10.26 mA cm-2, which is higher than those of TiO2/Au (4.34 mA cm-2), TiO2/NCD (7.55 mA cm-2) and TiO2 (3.34 mA cm-2). The evolved oxygen of TiO2/NCD/Au reaches 125.8 µmol after 5000 s test. The energy bands of complexes are very similar to that of the unmodified TiO2 catalyst due to the low content modification of NCDs and Au. In addition, the transient photovoltage (TPV) tests with a series of control samples show differences about the carriers' separation and transfer process, which verify that Au can increase the separation quantity of electron-hole pairs while NCDs play a more important role on the increase of the separation quantity and separation rate simultaneously. This work quantifies the function of each component in a composite catalyst and deepens the understanding of the catalyst interface design.

Iridium metallene oxide for acidic oxygen evolution catalysis.

Exploring new materials is essential in the field of material science. Especially, searching for optimal materials with utmost atomic utilization, ideal activities and desirable stability for catalytic applications requires smart design of materials' structures. Herein, we report iridium metallene oxide: 1 T phase-iridium dioxide (IrO2) by a synthetic strategy combining mechanochemistry and thermal treatment in a strong alkaline medium. This material demonstrates high activity for oxygen evolution reaction with a low overpotential of 197 millivolt in acidic electrolyte at 10 milliamperes per geometric square centimeter (mA cmgeo-2). Together, it achieves high turnover frequencies of 4.2 sUPD-1 (3.0 sBET-1) at 1.50 V vs. reversible hydrogen electrode. Furthermore, 1T-IrO2 also shows little degradation after 126 hours chronopotentiometry measurement under the high current density of 250 mA cmgeo-2 in proton exchange membrane device. Theoretical calculations reveal that the active site of Ir in 1T-IrO2 provides an optimal free energy uphill in *OH formation, leading to the enhanced performance. The discovery of this 1T-metallene oxide material will provide new opportunities for catalysis and other applications.

Regulating Electronic Spin Moments of Single-Atom Catalyst Sites via Single-Atom Promoter Tuning on S-Vacancy MoS2 for Efficient Nitrogen Fixation.

The electrocatalytic activity of transition-metal (TM)-based catalysts is correlated with the spin states of metal atoms. However, developing a way to manipulate spin remains a great challenge. Using first-principles calculations, we first report the crucial role of the spin of exposed Mo atoms around an S-vacancy in the electrocatalytic dinitrogen reduction reaction on defective MoS2 nanosheets and propose a novel strategy for regulating the electronic spin moments by tuning a single-atom promoter (SAP). Single TM atoms adsorbed on a defective MoS2 basal plane serve as SAPs via a noncontact interaction with an exposed Mo active site, inducing a significant spin polarization that promotes N2 adsorption and activation. Interestingly, by changing only the adsorption site of the TM atom, we are able to change the spin moments of the Mo atom, over a wide range of tunable values. The spin moments can be tuned to largely improve the catalytic activity of MoS2 toward the reduction of N2 to NH3.

Synergistic Effect of Boron Nitride and Carbon Domains in Boron Carbide Nitride Nanotube Supported Single-Atom Catalysts for Efficient Nitrogen Fixation.

Developing the low-cost and efficient single-atom catalysts (SACs) for nitrogen reduction reaction (NRR) is of great importance while remains as a great challenge. The catalytic activity, selectivity and durability are all fundamentally related to the elaborate coordination environment of SACs. Using first-principles calculations, we investigated the SACs with single transition metal (TM) atom supported on defective boron carbide nitride nanotubes (BCNTs) as NRR electrocatalysts. Our results suggest that boron-vacancy defects on BCNTs can strongly immobilize TM atoms with large enough binding energy and high thermal/structural stability. Importantly, the synergistic effect of boron nitride (BN) and carbon domains comes up with the modifications of the charge polarization of single-TM-atom active site and the electronic properties of material, which has been proven to be the essential key to promote N2 adsorption, activation, and reduction. Specifically, six SACs (namely V, Mn, Fe, Mo, Ru, and W atoms embedded into defective BCNTs) can be used as promising candidates for NRR electrocatalysts as their NRR activity is higher than the state-of-the art Ru(0001) catalyst. In particular, single Mo atom supported on defective BCNTs with large tube diameter possesses the highest NRR activity while suppressing the competitive hydrogen evolution reaction, with a low limiting potential of -0.62 V via associative distal path. This work suggests new opportunities for driving NH3 production by carbon-based single-atom electrocatalysts under ambient conditions.

[Spatial heterogeneity of soil water physical properties in coal gangue pile in arid desert area]. / å¹²æ—±è’æ¼ åŒºç ¤çŸ¸çŸ³å±±è¦†åœŸåŒºåœŸå£¤æ°´åˆ†ç‰©ç†æ€§è´¨çš„ç©ºé—´å¼‚è´¨æ€§.

Based on grid sample method (20 m×20 m), spatial heterogeneity and distribution of soil water physical properties from 0 to 5 cm of the coal gangue pile in arid desert area were explored by using classical statistics and geostatistics methods. The results showed that the variation of soil bulk density, capillary porosity, capillary maximum moisture capacity, total porosity and saturated moisture contents were weak, while water content showed a moderate variation. The best fitting model of soil bulk density was Gaussian model, and exponential model was the best fitting model for other indices. The C0/(C0+C) values of soil bulk density and water content were low and had strong spatial autocorrelation. The capillary porosity, capillary maximum moisture capacity, total porosity and soil saturated moisture showed moderate spatial autocorrelation. Soil bulk density was negatively correlated with capillary porosity, capillary maximum moisture capacity, total porosity and water content, whereas there was no significant correlation between soil moisture content and other indices. Soil capillary porosity, capillary maximum moisture capacity, total porosity, and saturated water content showed a significant synergistic effect between each other. On Kriging contour maps, capillary porosity, capillary maximum moisture capacity, total porosity and saturated moisture had a similar spatial pattern, with high values on the middle and the left side of the lower slope, whereas soil bulk density showed an opposite pattern. Soil water content was mainly affected by the slope position and increased from the upper slope to the lower slope. Our results suggested that land preparation measures should be taken to loosen the soil in root area over the coal gangue pile in arid desert area during vegetation restoration. Moreover, irrigation amount should be properly increased on the upper slope during the initial stage of vegetation restoration, which could improve soil moisture status in the overlying soil area of coal gangue and create uniform and suitable soil water physical conditions for vegetation restoration.

Realizing a Not-Strong-Not-Weak Polarization Electric Field in Single-Atom Catalysts Sandwiched by Boron Nitride and Graphene Sheets for Efficient Nitrogen Fixation.

Developing efficient single-atom catalysts (SACs) for nitrogen fixation is of great importance while remaining a great challenge. The lack of an effective strategy to control the polarization electric field of SACs limits their activity and selectivity. Here, using first-principles calculations, we report that a single transition metal (TM) atom sandwiched between hexagonal boron nitride (h-BN) and graphene sheets (namely, BN/TM/G) acts as an efficient SAC for the electrochemical nitrogen reduction reaction (NRR). These sandwich structures realize stable and tunable interfacial polarization fields that enable the TM atom to donate electrons to a neighboring B atom as the active site. As a result, the partially occupied pz orbital of a B atom can form B-to-N π-back bonding with the antibonding state of N2, thus weakening the N≡N bond. The not-strong-not-weak electric field on the h-BN surface further promotes N2 adsorption and activation. The NRR catalytic activity of the BN/TM/G system is highly correlated with the degree of positively polarized charges on the TM atom. In particular, BN/Ti/G and BN/V/G are identified as promising NRR catalysts with high stability, offering excellent energy efficiency and suppression of the competing hydrogen evolution reaction.

Synergistic Effect of Surface-Terminated Oxygen Vacancy and Single-Atom Catalysts on Defective MXenes for Efficient Nitrogen Fixation.

The production of ammonia (NH3) from molecular dinitrogen (N2) under ambient conditions is of great significance but remains as a great challenge. Using first-principles calculations, we have investigated the potential of using a transition metal (TM) atom embedded on defective MXene nanosheets (Ti3-xC2Oy and Ti2-xCOy with a Ti vacancy) as a single-atom electrocatalyst (SAC) for the nitrogen reduction reaction (NRR). The Ti3-xC2Oy nanosheet with Mo and W embedded, and the Ti2-xC2Oy nanosheet with Cr, Mo, and W embedded, can significantly promote the NRR while suppressing the competitive hydrogen evolution reaction, with the low limiting potential of -0.11 V for W/Ti2-xC2Oy. The outstanding performance is attributed to the synergistic effect of the exposed Ti atom and the TM atom around an extra oxygen vacancy. The polarization charges of the active center are reasonably tuned by the embedded TM atoms, which can optimize the binding strength of key intermediate *N2H. The good feasibility of preparing such TM SACs on defective MXenes and the high NRR selectivity with regard to the competitive HER suggest new opportunities for driving NH3 production by MXene-based SAC electrocatalysts under ambient conditions.

One-Step Direct Fixation of Atmospheric CO2 by Si-H Surface in Solution.

The efficient conversion of carbon dioxide (CO2) into useful chemicals has important practical significance for environmental protection. Until now, direct fixation of atmospheric CO2 needs first extraction from the atmosphere, an energy-intensive process. Silicon (or Si-H surface), Earth-abundant, low-cost and non-toxic, is a promising material for heterogeneous CO2 chemical fixation. Here we report one-step fixing of CO2 directly from the atmosphere to a paraformaldehyde-like polymer by Si-H surface at room temperature. With the assistance of HF, commercial silicon powder was used as a heterogeneous reducing agent, for converting gaseous CO2 to a polymer of fluorine substituted polyoxymethylene and hydroxyl substituted polyoxymethylene alternating copolymer (F-POM). Making use of the Si-H surface toward the fixation of atmospheric gaseous CO2 is a conceptually distinct and commercially interesting strategy for making useful chemicals and environmental protection.

Rhodium Nanoparticles/F-Doped Graphene Composites as Multifunctional Electrocatalyst Superior to Pt/C for Hydrogen Evolution and Formic Acid Oxidation Reaction.

Highly efficient electrocatalysis for clean, efficient, and sustainable energy supply, such as hydrogen evolution reaction (HER) and formic acid oxidation reaction (FAOR), has drawn enthusiastic and worldwide attention. Universal and efficient electrocatalysts for these reactions are essential elements for the development of renewable and clean energy technologies. Herein, we show the design and fabrication of the rhodium nanoparticles modified fluorine-doped graphene (Rh/F-graphene) catalyst using silicon nanowires (SiNWs) as the sacrifice template. The optimized Rh/F-graphene catalyst (Rh/F-graphene-2) has a low Rh mass fraction of 9.4% and F doping of 4.0%. The mean diameter of Rh is 9.39 nm. Rh/F-graphene-2 serves as a proton-adsorption-dominated multifunctional electrocatalyst for both HER and FAOR with performance superior to 20 wt % Pt/C in acidic solution. In addition, due to the doping of fluorine, the stability of Rh/F-graphene-2 catalyst greatly improves and is the best among all the compared electrocatalysts. This design for multifunctional catalysts could greatly increase the utilization ratio of Rh, which may provide a new avenue for the preparation of other noble metal-based catalysts.

Investigation of the status quo of massive blood transfusion in China and a synopsis of the proposed guidelines for massive blood transfusion.

The aim of this study was to provide an overview of massive transfusion in Chinese hospitals, identify the important indications for massive transfusion and corrective therapies based on clinical evidence and supporting experimental studies, and propose guidelines for the management of massive transfusion. This multiregion, multicenter retrospective study involved a Massive Blood Transfusion Coordination Group composed of 50 clinical experts specializing in blood transfusion, cardiac surgery, anesthesiology, obstetrics, general surgery, and medical statistics from 20 tertiary general hospitals across 5 regions in China. Data were collected for all patients who received ≥10 U red blood cell transfusion within 24 hours in the participating hospitals from January 1 2009 to December 31 2010, including patient demographics, pre-, peri-, and post-operative clinical characteristics, laboratory test results before, during, and after transfusion, and patient mortality at post-transfusion and discharge. We also designed an in vitro hemodilution model to investigate the changes of blood coagulation indices during massive transfusion and the correction of coagulopathy through supplement blood components under different hemodilutions. The experimental data in combination with the clinical evidence were used to determine the optimal proportion and timing for blood component supplementation during massive transfusion. Based on the findings from the present study, together with an extensive review of domestic and international transfusion-related literature and consensus feedback from the 50 experts, we drafted the guidelines on massive blood transfusion that will help Chinese hospitals to develop standardized protocols for massive blood transfusion.

Simple and sensitive electrogenerated chemiluminescence peptide-based biosensor for detection of matrix metalloproteinase 2 released from living cells.

A simple and sensitive electrogenerated chemiluminescence biosensor was developed to monitor matrix metalloproteinase 2 (MMP-2) by employing a specific peptide (CGPLGVRGK) as a molecular recognition substrate. Bis(2,2'-bipyridine)-4'-methyl-4-carboxybipyridine-ruthenium N-succinimidyl ester-bis(hexafluorophosphate) (Ru(bpy)2(mcbpy-O-Su-ester)(PF6)2 (Ru1) was used as ECL-emitting species and covalently labeled onto the peptide through NH2-containing lysine on the peptide via acylation reaction to form Ru1-peptide as an ECL probe. An ECL peptide-based biosensor was fabricated by self-assembling the ECL probe onto the surface of gold electrode. MMP-2 can specifically cleave the Ru1-peptide on the electrode surface, which led the partly Ru1-peptide to leave the electrode surface and resulted in the decrease of the ECL intensity obtained from the resulted electrode in 0.1 M phosphate-buffered saline (pH 7.4) containing tri-n-propylamine. The decreased ECL intensity was piecewise linear to the concentration of MMP-2 in the range from 1 to 500 ng/mL. Moreover, the ECL biosensor is successfully applied to detection of MMP-2 secreted by living cell, such as HeLa cells. Additionally, the biosensor was also applied to the evaluation of matrix metalloproteinase inhibitors. The strategy presented here is promising for other disease-related matrix metalloproteinase assay and matrix metalloproteinase inhibitor profiling with sensitivity and simplicity. Graphical Abstract Detection of MMP-2 released from living cells by ECL peptide-based biosensor.

Sensitive and versatile electrogenerated chemiluminescence biosensing platform for protein kinase based on Ru(bpy)3(2+) functionalized gold nanoparticles mediated signal transduction.

A novel, sensitive and versatile electrogenerated chemiluminescence biosensing platform is developed for monitoring activity and inhibition of protein kinase based on Ru(bpy)3(2+) functionalized gold nanoparticles (Ru(bpy)3(2+)-AuNPs) mediated signal transduction. Ru(bpy)3(2+)-AuNPs were formed by functionalizing AuNPs with Ru(bpy)3(2+) through electrostatic interactions and were used as thiol-versatile signal probe. Casein kinase II (CK2) and cAMP-dependent protein kinase (PKA), two classical protein kinase implicated in disease, were chosen as model protein kinases while a CK2-specific peptide (CRRRADDSDDDDD) and a PKA-specific peptide (CLRRASLG) were employed as molecular substrate for CK2 and PKA, respectively. The specific peptide was self-assembled onto the gold electrode via Au-S bond to form ECL biosensor. Upon thiophosphorylation of the peptide on the electrode in the presence of protein kinase and co-substrate adenosine-5'-(γ-thio)-triphosphate, Ru(bpy)3(2+)-AuNPs was assembled onto the thiophosphorylated peptides via Au-S bond. The Ru(bpy)3(2+)-AuNPs attached on electrode surface produce detectable ECL signal in the presence of coreactant tripropylamine. This strategy is promising for multiple protein kinase assay and kinase inhibitor profiling with high sensitivity, good selectivity and versatility. The ECL intensity is proportional to the activity of CK2 in the range of 0.01-0.5 unit/mL with a low detection limit of 0.008 unit/mL and to the activity of PKA in the range of 0.01-0.4 unit/mL with a detection limit of 0.005 unit/mL. Additionally, this assay was applied to the detection of CK2 in serum samples and the inhibition of CK2 and PKA. This work demonstrates that the developed ECL method can provide a sensitive and versatile platform for the detection of kinase activity and drug-screening.

Investigation of the current situation of massive blood transfusion in different surgical departments: a large multicenter study in China.

OBJECTIVE: This study aims to learn about the current situation of surgical massive blood transfusion of different surgical departments in China's Tertiary hospitals, which could provide the basis for the formulation of guidelines on massive blood transfusion. METHOD: A multicenter retrospective research on the application status of blood constituents during massive blood transfusion was conducted and a comparative analyses of survival and length of hospitalization in patients from different departments (trauma, cardiac surgery, obstetric conditions, or other common surgeries), were performed. RESULT: In China, during massive blood transfusion the ratio of the dosage of fresh frozen plasma to the dosage of red blood cell suspension reached 1:1-2, while the dosage of platelet and cryoprecipitate appeared to be very small. The risk of in-hospital death were associated with the primary disease in patients receiving massive blood transfusion (Log-Rank P = 0.000), cardiac surgery and trauma patients who received massive blood transfusion have a higher risk of death rate. CONCLUSIONS: Patients undergoing massive blood transfusion among different surgical departments have a certain difference in use of blood transfusion, mortality rate and the time of death. Our findings suggested that we should set up an independent transfusion program in cardiac surgery and trauma patients of massive blood transfusion.

Hemostatic function of packed red blood cells: an in-vitro study.

Clinical observations suggest that red blood cells (RBCs) participate directly in hemostasis. We designed an in-vitro system aimed at evaluating the hemostatic function of RBCs. Blood samples were collected from 20 healthy volunteers and packed RBCs (PRBCs) were supplied by the Shaanxi Province Blood Center. We investigated the effect of RBCs and hemoglobin concentration on the hemostatic function in vitro by thromboelastography. The activation of platelets was evaluated by detecting their active markers through flow cytometry. PRBCs ameliorated the coagulation disorders induced by dilution of the blood in vitro. However, addition of hemoglobin did not increase the blood coagulation, as the level of hemoglobin was negatively correlated to the clot index. Furthermore, washing PRBCs to remove contaminating residual clotting factors and platelets excluded that the coagulation effect of the PRBCs transfusion was because of the RBCs itself. Platelet activity in PRBCs exposed to storage greater than 3 weeks was not significantly reduced consistent with it being a possible contributor. Therefore, we postulate that the suspected coagulation effects ascribed to the PRBCs at transfusion may simply be because of residual clotting factors and active platelets incompletely removed in the preparation of PRBCs rather than because of the red cell membrane or its contents.

Balanced ratio of plasma to packed red blood cells improves outcomes in massive transfusion: A large multicenter study.

Resuscitation with the early administration of plasma can improve the survival of patients undergoing surgery or trauma patients who require massive transfusion. To ascertain the optimal ratio of fresh frozen plasma (FFP) to packed red blood cells (pRBCs) in massive transfusions, the records of 1,048 patients who received a massive transfusion at 20 hospitals were retrospectively reviewed. The patients were stratified into three groups according to the ratio of FFP to pRBCs. These were the low (<1:2.3), middle (1:2.3-0.75) and high (≥1:0.75) ratio groups. For 24-h treatment, the middle FFP:pRBC ratio led to a lower mortality rate (9.31%) compared with that in the low (11.83%) and high (11.44%) ratio groups (P=0.477). For 72-h treatment, the middle FFP:pRBC ratio also lead to the lowest mortality rate (7.25%), which was significantly lower than the ratios in the low (10.39%) and high (13.65%) ratio groups (P=0.007). The length of hospital stay, ICU stay, and FFP:pRBC ratio in 72 h were found to be significant associated with mortality. The optimal ratio of FFP to pRBCs of 1:2.3-0.75 in 72 h can improve the survival of patients undergoing massive transfusions.

Association between frequency of blood tests and mortality rate in patients undergoing massive blood transfusion: a multicenter study in five regions of China.

In order to provide Chinese clinicians with guidelines for the management of massive blood loss, we investigated the correlation between the frequency of blood tests and the mortality rate in patients undergoing massive blood transfusion (MBT). The aim of this study is to provide Chinese clinicians with guidelines for the management of massive blood loss. We retrospectively reviewed the medical records of patients who underwent massive blood transfusion (MBT) from 20 tertiary hospitals in 5 regions of China. The frequency of blood tests performed within 24 or 72 hours was compared between patients infused with < 10 and ≥ 10 U of red blood cells (RBC). The correlation between the frequency of blood tests and the mortality rate was determined. A high frequency of blood tests was associated with a low mortality rate in MBT cases. The frequency of all blood tests performed within 24 hours was negatively correlated with the mortality rate in patients infused with ≥ 10 U of RBC, while the frequency of blood coagulation tests performed within 72 hours was negatively correlated with the mortality rate in both patients infused with ≥ 10 and < 10 U of RBC. In conclusions: Measuring the blood indices frequently within the first 24 hours of MBT links to lower mortality rate. Coagulation indices in MBT patients should be closely monitored in the long term to help improve survival.