A Comparison between Thromboelastography and Conventional Clotting Tests in Pediatric Patients After Cardiopulmonary Bypass Procedure.

BACKGROUND: The coagulation system is more complicated in younger infants because the hemostatic system is not completely mature before 6 months. There is confusion among pediatricians to choose conventional coagulation tests and thromboelastography (TEG) to evaluate coagulation function for infants in major surgery. This study was undertaken to perform a comparison between the two methods for pediatric patients who underwent cardio-pulmonary bypass (CPB) surgery. METHODS: Infant patients who underwent CPB surgery were divided into two groups - younger group (age < 6 months old, n = 72) and older group (age from 6 months old to 12 years old, n = 76). Prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), and fibrinogen (Fib) of conventional coagulation tests and reaction time (R-time), speed of fibrin building up (ɑ-Angle), clot conformation time (K-time), maximum colt amplitude (MA) of TEG results before and after CPB, as well as increasing or decreasing rate of all the values after CPB, were compared between the two groups. Postoperative transfusion details were summarized. RESULTS: PT, APTT, R-time, and K-time markedly increased (p < 0.05) and Fib, ɑ-Angle, and MA decreased (p < 0.05) after CPB in both groups. The younger group had a much higher rate of postoperative transfusion with suspended red cells (54.17% vs. 17.11%), fresh frozen plasma (29.17% vs. 9.21%), cryoprecipitate (9.72% vs. 1.32%), and apheresis platelet (5.56% vs. 0) than the older group. Increasing rate of R-time and K-time and decreasing rate of ɑ-Angle and MA after CPB in the younger group were significantly higher than that in the older group (p < 0.01), whereas no significant differences were observed in conventional coagulation tests (p > 0.2). CONCLUSIONS: TEG was more sensitive than conventional coagulation tests in response to variation of coagulation function for younger infants after major surgery.

Clinical value of combination detection of direct antiglobulin test and serum albumin globulin ratio in severe hyperbilirubinemia caused by ABO hemolytic disease of the newborn.

Background To explore of a combination of antiglobulin test(DAT) and albumin globulin ratio(AGR) could predict the severity of ABO hemolytic disease of the newborn(ABO-HDN).Methods The measurement of DAT, AGR and combination detection of DAT and AGR was done to predict severe ABO-HDN hyperbilirubinemia in 270 full-term infants based on whether the infants received transfusions of blood components. The infants were divided into three groups according to the results of DAT and ARG and compared the differences of phototherapy day and hospitalization day of the three groups.Results Of the 270 cases enrolled in this study, 69 infants were DAT positive. Peak total bilirubin, AGR, and positive DAT were independently associated with the need for blood components transfusion. ROC curve analysis for blood components transfusion showed that DAT cutoff value >± with a sensitivity of 39.4% and a specificity of 83.9%, AGR cutoff value <2.05 with a sensitivity of 54.1% and a specificity of 85.7%, and combination detection of DAT and ARG with a sensitivity of 62.1% and a specificity of 91.2%. The AUCs for DAT, AGR, and combination detection of DAT and AGR were .621, .740, and .750 respectively. The phototherapy day and hospitalization day were significantly longer in group of AGR <2.05 and DAT >± than that of a group of AGR <2.05 and group of DAT >±.Conclusions DAT and ARG could be early predictors for the severity ABO-HDN hyperbilirubinemia and combination detection of DAT and AGR could further increase its predictive value.

[Differences in the ecological resilience of planted and natural Pinus massoniana and Cunninghamia lanceolata forests in response to drought in subtropical China]. / 亚热带人工和天然马尾松、杉木林生长对干旱的生态弹性差异.

We sampled Pinus massoniana and Cunninghamia lanceolata in both plantation and natural forests in central and western Fujian Province, China. Using tree-ring width, tree-ring width index, and basal area increment, we reconstructed the annual growth of 109 conifer individuals from four sites for the 20-year period from 1993 to 2012. We then calculated resistance, recovery, and resilience indices of those trees in response to two consecutive extreme droughts (2003-2004 and 2011) and analyzed the differences in resistance and resilience between plantations and natural fore-sts. The results showed that there were temporal differences in moisture requirements between P. massoniana and C. lanceolata, which accounted for their inconsistent responses to drought in 2003-2004. For both species, drought induced a marked growth reduction, without any clear lag effect. The growth responses during and following the 2003-2004 drought were significantly stronger than that for the 2011 drought. Those results indicated that P. massoniana was more resilient to drought stress than C. lanceolata, and the natural forests were more sensitive than plantations, but with stronger capacity to recover. C. lanceolata plantations were more susceptible to frequent extreme drought events. To mitigate the vulnerability of plantation trees to more frequent droughts in the future, we suggested select trees from genetic provenances with strong drought resistance.

Structural Basis and Function of the N Terminus of SARS-CoV-2 Nonstructural Protein 1.

Nonstructural protein 1 (Nsp1) of severe acute respiratory syndrome coronaviruses (SARS-CoVs) is an important pathogenic factor that inhibits host protein translation by means of its C terminus. However, its N-terminal function remains elusive. Here, we determined the crystal structure of the N terminus (amino acids [aa] 11 to 125) of SARS-CoV-2 Nsp1 at a 1.25-Å resolution. Further functional assays showed that the N terminus of SARS-CoVs Nsp1 alone loses the ability to colocalize with ribosomes and inhibit protein translation. The C terminus of Nsp1 can colocalize with ribosomes, but its protein translation inhibition ability is significantly weakened. Interestingly, fusing the C terminus of Nsp1 with enhanced green fluorescent protein (EGFP) or other proteins in place of its N terminus restored the protein translation inhibitory ability to a level equivalent to that of full-length Nsp1. Thus, our results suggest that the N terminus of Nsp1 is able to stabilize the binding of the Nsp1 C terminus to ribosomes and act as a nonspecific barrier to block the mRNA channel, thus abrogating host mRNA translation.

A single-center experience on exchange transfusion therapy in 123 full-term cases of severe neonatal hyperbilirubinemia in Wuhan.

OBJECTIVE: To describe the clinical experience in application of exchange transfusion therapy (ETT) in the treatment of severe neonatal hyperbilirubinemia. METHODS: The clinical data and examination results of severe neonatal hyperbilirubinemia full-term cases treated by ETT were analyzed retrospectively, the etiology and risk factors of severe neonatal hyperbilirubinemia were statistically analyzed, and the statistical characteristics of the children in each etiological group and the incidence of adverse events of ETT were analyzed. RESULTS: The age of jaundice, peak total bilirubin after phototherapy and ETT in 123 full-term infants were 2.0 (1.0, 3.0) days, 4.0 (2.0, 7.0) days and 4.0 (2.0, 7.0) days, respectively, of which 68 were male and 55 were female. The main pathogeny of severe neonatal hyperbilirubinemia was blood group incompatibility hemolytic disease of newborn (HDN). Age of ETT, total bilirubin after ETT, gender and BAEP results were different between ABE and non-ABE infants. Weight loss can be used as a predictor of hospitalization length. The major adverse events related to ETT were hypocalcemia, hypomagnesemia, hyponatremia and thrombocytopenia. CONCLUSIONS: ETT can rapidly reduce the level of total bilirubin to prevent ABE and play an important role in the treatment of neonatal hyperbilirubinemia, but the whole process of ETT needs to be closely monitored.

Interference in the indirect antiglobulin test and direct antiglobulin test from rheumatoid factor.

BACKGROUND: The indirect antiglobulin test (IAT) and direct antiglobulin test (DAT) have been used as common tests for transfusion. Recently, we have found that in addition to causing false increases, rheumatoid factor (RF) can also cause false decreases in immunoassays for hepatitis B surface antigen and B-type natriuretic peptide. However, it remains unclear whether RF also interferes with the IAT and DAT. METHODS: IAT models were produced by mixing IAT-positive plasma and RF-positive plasma, then one-step and two-step IATs were adopted for detection. DAT models were produced by mixing DAT-positive red blood cells (RBCs) and RF-positive plasma, followed by detection with the DAT. The DAT models were diluted using the same RF-positive plasma, and the DAT was performed again. RESULTS: The rate of decrease of the two-step IAT (40.63%) was significantly higher than that of the one-step IAT (31.51%). Both the rate of decrease (76.67%) and increase (16.67%) of the results of the 60 DAT models were significantly higher than those of the IAT models after two-fold dilution. CONCLUSIONS: The RF can lead to both false decreases and false increases in IAT and DAT. And the interference effects are related to the RF content relative to the IgG-sensitized RBCs.

Triptolide Inhibits Breast Cancer Cell Metastasis Through Inducing the Expression of miR-146a, a Negative Regulator of Rho GTPase.

Triptolide, an extract of Tripterygium wilfordii, has been shown to have a potent anticancer activity. In the present study, it was found that triptolide could effectively induce apoptosis and inhibit proliferation and invasion in malignant MDA-MB-231 breast cancer cells. The study focused on its effect on inhibiting invasion, which has not been extensively reported to date. We predicted that triptolide may change invasion activity via microRNAs (miRNAs), which have been recognized as important regulators of gene expression. miRNAome variation in MDA-MB-231 cells with or without triptolide treatment demonstrated that miR-146a was upregulated following treatment with triptolide. Our previous studies have shown that miR-146a can inhibit migration and invasion by targeting RhoA in breast cancer. This time, we found that miR-146a can target Rac1, another key member of the Rho GTPase family. Luciferase reporter containing Rac1 3'-UTR was constructed to prove this hypothesis. In addition, following treatment with triptolide, the expression of RhoA and Rac1 was found to be decreased. These results indicated that triptolide exerts its anti-invasion activity through a miRNA-mediated mechanism, which indirectly regulates the expression of Rho GTPase. Triptolide combined with miR-146a could improve the effect of triptolide treatment on breast cancer.

Establishing a reference range for thromboelastograph parameters in the neonatal period.

INTRODUCTION: Acquired coagulation disorders are a common cause of neonatal bleeding. The thromboelastograph (TEG) comprehensively assesses haemostatic processes in the body. Unfortunately, the reference range of TEG parameters in the neonatal period has not yet been evaluated, which limits the use of the TEG in neonates. In this study, we aimed to establish the reference range of TEG parameters for the neonatal period. METHODS: This study included 371 full-term infants (≥37 weeks of gestation), and we divided these infants into three groups according to age as follows: 1, 2-7 and 8-28 days. We measured their peripheral blood using TEG, coagulation routine and platelet count tests. We analysed differences among the groups. RESULTS: The reference ranges for TEG parameters are presented as medians and reference ranges (2.5th and 97.5th percentiles) as follows: R (clot reaction time, seconds) 4.80 (2.80-7.17), Angle (fibrin production rate) 69.90 (44.91-78.89), K (clot kinetics, min) 1.40 (0.80-4.50), MA (maximum amplitude, mm) 63.50(44.34-74.66) and LY30 (lysis at 30 minutes, %) 0.10 (0.10-6.95). There were significant differences in Angle, K, MA and LY30 values between the different neonatal day age groups. CONCLUSION: This study preliminarily establishes a reference range for TEG parameters during the neonatal period. The age of a newborn had a large influence on TEG parameters. Additionally, we demonstrated a correlation between laboratory tests and TEG parameters for this age period. The reference values provided herein are meaningful for future studies.

A method for simulating the release of natural gas from the rupture of high-pressure pipelines in any terrain.

The rupture of a high-pressure natural gas pipeline can pose a serious threat to human life and environment. In this research, a method has been proposed to simulate the release of natural gas from the rupture of high-pressure pipelines in any terrain. The process of gas releases from the rupture of a high-pressure pipeline is divided into three stages, namely the discharge, jet, and dispersion stages. Firstly, a discharge model is established to calculate the release rate of the orifice. Secondly, an improved jet model is proposed to obtain the parameters of the pseudo source. Thirdly, a fast-modeling method applicable to any terrain is introduced. Finally, based upon these three steps, a dispersion model, which can take any terrain into account, is established. Then, the dispersion scenarios of released gas in four different terrains are studied. Moreover, the effects of pipeline pressure, pipeline diameter, wind speed and concentration of hydrogen sulfide on the dispersion scenario in real terrain are systematically analyzed. The results provide significant guidance for risk assessment and contingency planning of a ruptured natural gas pipeline.

Visual and efficient immunosensor technique for advancing biomedical applications of quantum dots on Salmonella detection and isolation.

It is a great challenge in nanotechnology for fluorescent nanobioprobes to be applied to visually detect and directly isolate pathogens in situ. A novel and visual immunosensor technique for efficient detection and isolation of Salmonella was established here by applying fluorescent nanobioprobes on a specially-designed cellulose-based swab (a solid-phase enrichment system). The selective and chromogenic medium used on this swab can achieve the ultrasensitive amplification of target bacteria and form chromogenic colonies in situ based on a simple biochemical reaction. More importantly, because this swab can serve as an attachment site for the targeted pathogens to immobilize and immunologically capture nanobioprobes, our mAb-conjugated QD bioprobes were successfully applied on the solid-phase enrichment system to capture the fluorescence of targeted colonies under a designed excitation light instrument based on blue light-emitting diodes combined with stereomicroscopy or laser scanning confocal microscopy. Compared with the traditional methods using 4-7 days to isolate Salmonella from the bacterial mixture, this method took only 2 days to do this, and the process of initial screening and preliminary diagnosis can be completed in only one and a half days. Furthermore, the limit of detection can reach as low as 10(1) cells per mL Salmonella on the background of 10(5) cells per mL non-Salmonella (Escherichia coli, Proteus mirabilis or Citrobacter freundii, respectively) in experimental samples, and even in human anal ones. The visual and efficient immunosensor technique may be proved to be a favorable alternative for screening and isolating Salmonella in a large number of samples related to public health surveillance.

A spectral/temporal method for robust fundamental frequency tracking.

In this paper, a fundamental frequency (F(0)) tracking algorithm is presented that is extremely robust for both high quality and telephone speech, at signal to noise ratios ranging from clean speech to very noisy speech. The algorithm is named "YAAPT," for "yet another algorithm for pitch tracking." The algorithm is based on a combination of time domain processing, using the normalized cross correlation, and frequency domain processing. Major steps include processing of the original acoustic signal and a nonlinearly processed version of the signal, the use of a new method for computing a modified autocorrelation function that incorporates information from multiple spectral harmonic peaks, peak picking to select multiple F(0) candidates and associated figures of merit, and extensive use of dynamic programming to find the "best" track among the multiple F(0) candidates. The algorithm was evaluated by using three databases and compared to three other published F(0) tracking algorithms by using both high quality and telephone speech for various noise conditions. For clean speech, the error rates obtained are comparable to those obtained with the best results reported for any other algorithm; for noisy telephone speech, the error rates obtained are lower than those obtained with other methods.

Towards guest-zeolite interactions: an NMR spectroscopic approach.

Guest(metal)-zeolite interactions in a two component heterogeneous catalyst have been investigated by high-field and high-speed (27)Al MAS NMR, and two-dimensional (27)Al MQ MAS NMR experiments as well as ab initio DFT methods. It was established that strong interactions between guest and zeolite occur in a metal/zeolite system, with the metal anchored to the tetrahedral aluminum framework site through two oxygen bridges. It disturbs the tetrahedral environment of associated aluminum framework, changing AlO(4) geometry from near T(d) to C(2v); this enables us to resolve this species from the undisturbed aluminum framework species in high-field (27)Al MAS NMR and two-dimesional (27)Al MQ MAS NMR experiments.

An investigation of the roles of surface aluminum and acid sites in the zeolite MCM-22.

Ammonia adsorption studies reveal that the observed Lewis acidity in the zeolite MCM-22 is derived from at least two types of framework aluminum sites (AlF), that is, octahedral AlF and three-coordinate AlF. Comparative ammonia or trimethylphosphine (TMP) adsorption experiments with MCM-22 confirm that octahedral Al species gives rise to the signal at delta(iso) approximately 0 in the 27Al NMR spectrum; this is a superposition of two NMR signals from the different Al species on the water-reconstructed zeolite surface. A sharp resonance assigned to framework Al reversibly transforms on ammonia adsorption to delta(iso)27Al approximately 55 from tetrahedral AlF, while the broad peak is assigned to nonframework aluminum which results from hydrothermal treatment. This study also demonstrates the effectiveness of 27Al magic angle spinning (MAS) and multiple quantum (MQ) MAS NMR spectroscopy as a technique for the study of zeolite reactions.