Pharmacokinetic Modeling Using Real-World Data to Optimize Unfractionated Heparin Dosing in Pediatric Patients on Extracorporeal Membrane Oxygenation and Evaluate Target Achievement-Clinical Outcomes Relationship.

Unfractionated heparin (UFH) is a commonly used anticoagulant for pediatric patients undergoing extracorporeal membrane oxygenation (ECMO), but evidence is lacking on the ideal dosing. We aimed to (1) develop a population pharmacokinetic (PK) model for UFH, measured through anti-factor Xa assay; (2) optimize UFH starting infusions and dose titrations through simulations; and (3) explore UFH exposure-clinical outcomes relationship. Data from 218 patients admitted to Utah's Primary Children's Hospital were retrospectively collected. A 1-compartment PK model with time-varying clearance (CL) adequately described UFH PK. Weight on CL and volume of distribution and ECMO circuit change on CL were significant covariates. The typical estimates for initial CL and first-order rate constant to reach steady-state CL were 0.57 L/(h·10 kg) and 0.02/h. Comparable to non-ECMO patients, the typical steady-state CL was 0.81 L/(h·10 kg). Simulations showed that a 75 IU/kg UFH bolus dose followed by starting infusions of 25 and 20 IU/h/kg for patients aged younger than 6 years and 6 years or older, respectively, achieved the therapeutic target in 56.6% of all patients, whereas only 3.1% exceeded the target. The proposed UFH titration schemes achieved the target in more than 90% of patients while less than 0.63% were above the target after 24 and 48 hours of treatment. The median intensive care unit survival time in patients within and below the target at 24 hours was 136 and 66 hours, respectively. In conclusion, PK model of UFH was developed for pediatric patients on ECMO. The proposed UFH dosing scheme attained the anti-factor Xa target rapidly and safely.

Developing the next generation of renewable energy technologies: an overview of low-TRL EU-funded research projects.

A cluster of eleven research and innovation projects, funded under the same call of the EU's H2020 programme, are developing breakthrough and game-changing renewable energy technologies that will form the backbone of the energy system by 2030 and 2050 are, at present, at an early stage of development. These projects have joined forces at a collaborative workshop, entitled ' Low-TRL Renewable Energy Technologies', at the 10th Sustainable Places Conference (SP2022), to share their insights, present their projects' progress and achievements to date, and expose their approach for exploitation and market uptake of their solutions.

A mini-review on liquid air energy storage system hybridization, modelling, and economics: towards carbon neutrality.

The rapid increase in energy consumption around the world is the main challenge that compromises and affects the environment. Electricity generation, which mainly depends on fossil fuels, produces around 80% of CO2 emissions released into the atmosphere. Renewables are a remarkable alternative for energy production. However, they are intermittent sources of energy. Liquid air energy storage (LAES) is a medium-to large-scale energy system used to store and produce energy, and recently, it could compete with other storage systems (e.g., compressed air and pumped hydro), which have geographical constraints, affect the environment, and have a lower energy density than that of LAES. However, the low efficiency, high payback periods, and profit values of LAES hamper its commercialization. LAES is premature to be fully studied because lack of actual operating conditions and results from large plants, which affect the techno-economic predictions, in turn, affecting technology commercialization. Furthermore, the off-design conditions are not fully covered although it is a crucial step in system performance evaluation. To this end, the current mini-review sheds light on the LAES design, history, types, limitations, and the associated techno-economic analysis. In addition, state-of-the-art modelling tools are widely explained with benefits and shortage. Furthermore, LAES integration with other systems is explained widely, as it was found to boost the system performance and increase the profit with lower payback periods.

Highly Uniform Multi-Layers Reduced Graphene Oxide/Poly-2-aminobenzene-1-thiol Nanocomposite as a Promising Two Electrode Symmetric Supercapacitor under the Effect of Absence and Presence of Porous-Sphere Polypyrrole Nanomaterial.

A uniform and highly porous reduced graphene oxide/poly-2-aminobenzene-1-thiol multi-layer (R-GO/P2ABT-ML) nanocomposite was synthesized and characterized. The uniform layer structure and porosity of the nanocomposite, combined with its conductivity, make it an ideal candidate for use as a pseudo supercapacitor. To enhance the capacitance behavior, a porous ball structure polypyrrole (PB-Ppy) was incorporated into the nanocomposite. When tested at 0.2 A/g, the capacitance values of the R-GO/P2ABT-ML and R-GO/P2ABT-ML/PB-Ppy were found to be 19.6 F/g and 92 F/g, respectively, indicating a significant increase in capacitance due to the addition of PB-Ppy. The energy density was also found to increase from 1.18 Wh.kg-1 for R-GO/P2ABT-ML to 5.43 Wh.kg-1 for R-GO/P2ABT-ML/PB-Ppy. The stability of the supercapacitor was found to be significantly enhanced by the addition of PB-Ppy. The retention coefficients at 100 and 500 charge cycles for R-GO/P2ABT-ML/PB-Ppy were 95.6% and 85.0%, respectively, compared to 89% and 71% for R-GO/P2ABT-ML without PB-Ppy. Given the low cost, mass production capability, and easy fabrication process of this pseudo capacitor, it holds great potential for commercial applications. Therefore, a prototype of this supercapacitor can be expected to be synthesized soon.

Development of a multiscale mechanistic modeling framework integrating differential cellular kinetics of CAR T-cell subsets and immunophenotypes in cancer patients.

Chimeric antigen receptor (CAR) T-cell subsets and immunophenotypic composition of the pre-infusion product, as well as their longitudinal changes following infusion, are expected to affect CAR T-cell expansion, persistence, and clinical outcomes. Herein, we sequentially evolved our previously described cellular kinetic-pharmacodynamic (CK-PD) model to incorporate CAR T-cell product-associated attributes by utilizing published preclinical and clinical datasets from two affinity variants (FMC63 and CAT19 scFv) anti-CD19 CAR T-cells. In step 1, a unified cell-level PD model was used to simultaneously characterize the in vitro killing datasets of two CAR T-cells against CD19+ cell lines at varying effector:target ratios. In step 2, an augmented CK-PD model for anti-CD19 CAR T-cells was developed, by integrating CK dataset(s) from two bioanalytical measurements (quantitative polymerase chain reaction and flow cytometry) in patients with cancer. The model described the differential in vivo expansion properties of CAR T-cell subsets. The estimated expansion rate constant was ~1.12-fold higher for CAR+CD8+ cells in comparison to CAR+CD4+ T-cells. In step 3, the model was extended to characterize the disposition of four immunophenotypic populations of CAR T-cells, including stem-cell memory, central memory, effector memory, and effector cells. The model adequately characterized the longitudinal changes in immunophenotypes post anti-CD19 CAR T-cell infusion in pediatric patients with acute lymphocytic leukemia. Polyclonality in the pre-infusion product was identified as a categorical covariate influencing differentiation of immunophenotypes. In the future, this model could be leveraged a priori toward optimizing the composition of CAR T-cell infusion product, and further understand the CK-PD relationship in patients.

Insights into the Role of Erythrina corallodendron L. in Alzheimer's Disease: in Vitro and in Silico Approach.

Alzheimer's disease (AD) is a major health problem. Cholinergic transmission is greatly affected in AD. Phytochemical investigation of the alkaloid rich fraction (AF) of Erythrina corallodendron L leaves resulted in isolation of five known alkaloids: erysodine, erythrinine, 8-oxoerythrinine, erysovine N-oxide and erythrinine N-oxide. In this study, eysovine N-oxide was reported for the second time in nature. AF was assayed for cholinesterase inhibition at the concentration of 100 µg mL-1 . AF showed a higher percent inhibition for butyrylcholinesterase enzyme (BuChE) (83.28 %) compared to acetylcholinesterase enzyme (AChE) (64.64 %). The isolated alkaloids were also assayed for their anti-BuChE effect. In-silico docking study was done for the isolated compounds at the binding sites of AChE and BuChE to determine their binding pattern and interactions, also molecular dynamics were estimated for the compound displaying the best fit for AChE and BuChE. In addition, ADME parameters and toxicity were predicted for the isolated alkaloids compared to donepezil.

Characteristics of conventional high-risk coronary plaques and a novel CT defined thin-cap fibroatheroma in patients undergoing CCTA with stable chest pain.

BACKGROUND: Coronary computed tomography angiography (CCTA) can identify high-risk coronary plaque types. However, the inter-observer variability for high-risk plaque features, including low attenuation plaque (LAP), positive remodelling (PR), and the Napkin-Ring sign (NRS), may reduce their utility, especially amongst less experienced readers. METHODOLOGY: In a prospective study, we compared the prevalence, location and inter-observer variability of both conventional CT-defined high-risk plaques with a novel index based on quantifying the ratio of necrotic core to fibrous plaque using individualised X-ray attenuation cut-offs (the CT-defined thin-cap fibroatheroma - CT-TCFA) in 100 patients followed-up for 7 years. RESULTS: In total, 346 plaques were identified in all patients. Seventy-two (21%) of all plaques were classified by conventional CT parameters as high-risk (either NRS or PR and LAP combined), and 43 (12%) of plaques were considered high-risk using the novel CT-TCFA definition of (Necrotic Core/fibrous plaque ratio of >0.9). The majority (80%) of the high-risk plaques (LAP&PR, NRS and CT-TCFA) were located in the proximal and mid-LAD and RCA. The kappa co-efficient of inter-observer variability (k) for NRS was 0.4 and for PR and LAP combined 0.4. While the kappa co-efficient of inter-observer variability (k) for the new CT-TCFA definition was 0.7. During follow-up, patients with either conventional high-risk plaques or CT-TCFAs were significantly more likely to have MACE (Major adverse cardiovascular events) compared to patients without coronary plaques (p value 0.03 & 0.03, respectively). CONCLUSION: The novel CT-TCFA is associated with MACE and has improved inter-observer variability compared with current CT-defined high-risk plaques.

Effects of throat sizing and gasification agents in a biomass downdraft gasifier: towards CO2-free syngas production.

The gasification process in a downdraft biomass gasifier is investigated using Computational Fluid Dynamics (CFD). The aim is to develop a novel approach to reduce CO2 emissions from producer syngas while increasing the higher heating value (HHV). To this end, the effects of varying the throat diameter of the gasifier and gasifying media (air and oxygen) on the performance of gasification are investigated. The results reveal that as the throat ratio decreases for oxy-gasification, more CO, H2, and CH4 are produced, thus resulting in a HHV of 12.1 MJ Nm-3. For the same working conditions (ER, MC, and feedstock), the suggested design/optimum throat ratio of 0.14 is found to reduce CO2 by ∼55% compared to any other higher throat ratios, while simultaneously increasing HHV by ∼20% for both air and oxy-gasification cases. Additionally, the suggested throat ratio increases the gasification efficiency, carbon conversion and producer gas yield by 19%, 33%, and 22% respectively. Therefore, it shows a significant potential for CO2-free syngas production in the gasification process, demonstrating a promising technique that does not require any solvents, catalysts, absorbers, or additional CO2 removal. Lower throat ratios further favour the higher yield of syngas, HHV, gasification and conversion efficiencies, with better gasifier performance.

Model-based approach to identify predictors of paclitaxel-induced myelosuppression in "real-world" administration.

Taxanes are currently the most frequently used chemotherapeutic agents in cancer care, where real-world use has focused on minimizing adverse events and standardizing the delivery. Myelosuppression is a well-characterized, adverse pharmacodynamic effect of taxanes. Electronic health records (EHRs) comprise data collected during routine clinical care that include patients with heterogeneous demographic, clinical, and treatment characteristics. Application of pharmacokinetic/pharmacodynamic (PK/PD) modeling to EHR data promises new insights on the real-world use of taxanes and strategies to improve therapeutic outcomes especially for populations who are typically excluded from clinical trials, including the elderly. This investigation: (i) leveraged previously published PK/PD models developed with clinical trial data and addressed challenges to fit EHR data, and (ii) evaluated predictors of paclitaxel-induced myelosuppression. Relevant EHR data were collected from patients treated with paclitaxel-containing chemotherapy at Inova Schar Cancer Institute between 2015 and 2019 (n = 405). Published PK models were used to simulate mean individual exposures of paclitaxel and carboplatin, which were linearly linked to absolute neutrophil count (ANC) using a published semiphysiologic myelosuppression model. Elderly patients (≥70 years) constituted 21.2% of the dataset and 2274 ANC measurements were included in the analysis. The PD parameters were estimated and matched previously reported values. The baseline ANC and chemotherapy regimen were significant predictors of paclitaxel-induced myelosuppression. The nadir ANC and use of supportive treatments, such as growth factors and antimicrobials, were consistent across age quantiles suggesting age had no effect on paclitaxel-induced myelosuppression. In conclusion, EHR data could complement clinical trial data in answering key therapeutic questions.

Achievement of the ESC recommendations for secondary prevention of cardiovascular risk factors in high-risk patients with type 2 diabetes: A real-world national cohort analysis.

AIM: To assess compliance with European Society of Cardiology (ESC) secondary prevention recommendations in a nationwide contemporary population with diabetes mellitus (DM) and coronary artery disease. METHOD: We conducted a retrospective observational study using linked health data in patients across Wales with DM undergoing percutaneous coronary intervention (2012-2017). The follow-up was for one year. We analysed the clinical characteristics, medications, target levels for HbA1c, low-density lipoprotein cholesterol (LDL-C), non-high-density lipoprotein cholesterol (non-HDL-C) and blood pressure against the ESC prevention guidelines. RESULTS: Overall, 3478 patients with diabetes had available data at 1-year post-PCI. Only 43% had HbA1c levels <53 mmol/L, but 81% had blood pressure < 140/80 (current ESC targets). Prescribing frequency of the newer hypoglycaemic agents (glucagon-like peptide-1 receptor agonists and sodium-glucose co-transporter 2 inhibitors) was suboptimal, with a higher rate in patients with HbA1c ≥53 mmol/mol. Only 51% & 27% of the patients had LDL-C levels <1.8 &1.4 mmol/L (2016 & 2019 guidelines recommendations respectively), and 55% & 34% had non-HDL-C levels <2.6 & 2.2 mmol/L (2016 & 2019 guidelines respectively). Of the uncontrolled LDL-C patients, 42% (2016 target) and 35% (2019 target) were prescribed high-intensity statins. Females were more likely to have LDL-C targets above the recommended level. CONCLUSION: Achievement of ESC treatment goals in this very-high risk cohort for DM and hyperlipidaemia was far from optimal, with a low prescription rate of the guidelines-recommended therapy. Target goals for hypertension were met more frequently. An up-to-date analysis reflecting the current practice against the most recent guidelines is warranted.

A validated LC-MS/MS method for determination of antiviral prodrug molnupiravir in human plasma and its application for a pharmacokinetic modeling study in healthy Egyptian volunteers.

A fully validated, simple, rapid and reproducible liquid chromatography-tandem mass spectrometry method was developed to determine NHC (N-hydroxycytidine), the active metabolite of Molnupiravir (MOL) in human plasma; one of the limited treatment options for SARS-CoV-2 in plasma of healthy volunteers. The internal standard (IS) used was ribavirin. The extraction of analyte and IS from plasma was performed using acetonitrile as a solvent for protein precipitation. Agilent Zorbax Eclipse plus C18, 4.6 × 150 mm, (5 µm) was used for chromatographic separation using a mixture of methanol0.2 % acetic acid (5:95, v/v) as a mobile phase that was pumped at a flow rate of 0.9 mL/min. Detection was performed on a triple quadrupole mass spectrometer operating in multiple reaction monitoring (MRM) employing positive ESI interface using API4500 triple quadrupole tandem mass spectrometer system, with the transitions set at m/z 260.10 â†’ 128.10 and 245.10 â†’ 113.20 for NHC and IS respectively. Method validation was performed in accordance with United States FDA bioanalytical guidance. The concentration range of 20.0-10000.0 ng/mL was used to establish linearity via weighted linear regression approach (1/x2). Moreover, the analyzed pharmacokinetic data from twelve Egyptian healthy volunteers were used to develop a population pharmacokinetic model for NHC. The developed model was used to perform simulations and evaluate the current MOL dosing recommendations through calculating the maximum concentration (Cmax) "the safety metric" and area under the curve (AUC0-12 h) "the efficacy metric" for 1000 virtual subjects. Geometric mean ratios (GMR) with their associated 90% confidence intervals (CI) compared to literature values were computed. Geometric means of simulation-based Cmax and AUC0-12 were 3827 ng/mL (GMR = 1.05; 90% CI = 0.96-1.15) and 9320 ng.h/mL (GMR = 1.04; 90% CI = 0.97-1.11), respectively indicating that current MOL dosage can achieve the therapeutic targets and dose adjustment may not be required for the Egyptian population. The developed model could be used in the future to refine MOL dosage once further therapeutic targets are identified.

Anticoagulation and bleeding in the cancer patient.

Cancer patients have an increased risk of bleeding compared to non-cancer patients with anticoagulant therapy. A bleeding risk assessment before initiation of anticoagulation is recommended. Currently low molecular weight heparin (LMWH) and direct oral anticoagulants (DOACs) are the mainstays of treatment for cancer-associated venous thromboembolism (VTE). Since DOACs are administered orally, they offer some convenience and ease of administration; however, LMWH may be preferred in certain cancers. Given the prevalence of anticoagulant therapies in cancer patients, clinical providers must be able to recognize potentially critical bleeding sites and modalities to reverse major hemorrhage. Reversal agents or antidotes to bleeding may be required when bleeding is persistent or life-threatening. These include vitamin K, fresh frozen plasma (FFP), protamine, prothrombin complex concentrate (PCC) or andexanet alfa, and idarucizumab. Inferior vena cava (IVC) filter insertion can be also considered in those with major bleeding. Evidence for timing and need for re-initiation of anticoagulant therapy after a major bleeding remains sparse, but a multi-disciplinary approach and shared decision-making can be implemented in the interim.

Interspecies Comparison and Radiation Effect on Pharmacokinetics of BIO 300, a Nanosuspension of Genistein, after Different Routes of Administration in Mice and Non-Human Primates.

BIO 300, a suspension of synthetic genistein nanoparticles, is being developed for mitigating the delayed effects of acute radiation exposure (DEARE). The purpose of the current study was to characterize the pharmacokinetic (PK) profile of BIO 300 administered as an oral or parenteral formulation 24 h after sham-irradiation, total-body irradiation (TBI) with 2.5-5.0% bone marrow sparing (TBI/BMx), or in nonirradiated sex-matched C57BL/6J mice and non-human primates (NHP). C57BL/6J mice were randomized to the following arms in two consecutive studies: sham-TBI [400 mg/kg, oral gavage (OG)], TBI/BM2.5 (400 mg/kg, OG), sham-TBI [200 mg/kg, subcutaneous (SC) injection], TBI/BM2.5 (200 mg/kg, SC), sham-TBI (100 mg/kg, SC), or nonirradiated [200 mg/kg, intramuscular (IM) injection]. The PK profile was also established in NHP exposed to TBI/BM5.0 (100 mg/kg, BID, OG). Genistein-aglycone serum concentrations were measured in all groups using a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay. The PK profile demonstrates 11% and 19% reductions in Cmax and AUC0-inf, respectively, among mice administered 400 mg/kg, OG, after TBI/BM2.5 compared to the sham-TBI control arm. Administration of 200 mg/kg SC in mice exposed to TBI/BM2.5 showed a 53% increase in AUC0-inf but a 28% reduction in Cmax compared to the sham-TBI mice. The relative bioavailability of the OG route compared to the SC and IM routes in mice was 9% and 7%, respectively. After the OG route, the dose-normalized AUC0-inf was 13.37 (ng.h/mL)/(mg/kg) in TBI/BM2.5 mice compared to 6.95 (ng.h/mL)/(mg/kg) in TBI/BM5.0 NHPs. Linear regression of apparent clearances and weights of mice and NHPs yielded an allometric coefficient of 1.06. Based on these data, the effect of TBI/BMx on BIO 300 PK is considered minimal. Future studies should use SC and IM routes to maximize drug exposure when administered postirradiation. The allometric coefficient is useful in predicting therapeutic drug dose regimens across species for drug approval under the FDA animal rule.

Reassessing the Pediatric Dosing Recommendations for Unfractionated Heparin Using Real-World Data: A Pharmacokinetic-Pharmacodynamic Modeling Approach.

Optimal pediatric dosing of unfractionated heparin (UFH) is challenging because of the paucity of clinical outcome and pharmacokinetic-pharmacodynamic (PK/PD) studies in pediatrics. This study aimed to: (i) develop a PK/PD model for UFH, quantified by anti-factor Xa assay, and the UFH effect, measured by activated partial thromboplastin time (aPTT); and (ii) use simulations to evaluate pediatric UFH infusions for achieving the anti-factor Xa (0.3-0.7 IU/mL) therapeutic target. Electronic health record data were retrospectively collected from 633 patients aged <19 years admitted to Texas Children's Hospital. The PK/PD model was developed using a 70% (training)/30% (testing) split-sample approach. A 1-compartment PK model with linear elimination adequately described the UFH PK. An allometrically scaled body weight on clearance (CL) and volume of distribution (Vd) with an age-dependent maturation function of extracellular water on Vd were the covariates identified. Comparable with literature, the typical values for CL and Vd were 3.28 L/(h·50 kg) and 8.83 L/50 kg, respectively. A linear model adequately described the UFH-aPTT relationship with an estimated slope of 150 seconds/(IU/mL). Simulations of the currently recommended starting infusions (28 IU/h/kg for pediatrics <1 year old or 20 IU/h/kg for pediatrics >1 year old) showed that the anti-factor Xa therapeutic target was achieved only in 15.3%, 14.6%, 36.9%, and 45.11% of subjects in the age groups of <1 year, 1-6 years, 6-12 years, and 12-19 years, respectively. In conclusion, the UFH anti-factor Xa target is not achieved initially, especially in young pediatrics, suggesting the need to optimize UFH dosing to achieve higher therapeutic success.

Differential Expression of miR-21, miR-23a, and miR-27a, and Their Diagnostic Significance in Egyptian Colorectal Cancer Patients.

Background: Colorectal cancer (CRC) rates are affected by genetics, ethnicity, and environmental factors; it is considered one of the most aggressive human malignancies with high mortality and morbidity rates worldwide due, in part, to its asymptomatic nature during the early stages of disease. Objective: Owing to the impact of microRNA (miRNA) dysregulation on CRC development and progression, this study was conducted to explore the expression levels of mir-21, -23a, and -27a in the sera and tissues of Egyptian CRC patients and to evaluate their diagnostic efficacy based on circulating levels. Methods: In the test phase, the relative expression levels of the studied miRNAs were evaluated in the sera of 70 participants (35 CRC patients and 35 healthy controls) using quantitative real-time-polymerase chain reaction and to verify their diagnostic value. The exploratory phase was designed to validate the tumor-derived trait by comparing the miRNA levels in the cancerous and adjacent noncancerous tissues. Results: The relative expression levels of the studied miRNAs were significantly upregulated in both serum and tumor tissues of the patients compared to their corresponding controls. In addition, significant positive correlations were found between the relative expression levels of the studied miRNAs in serum samples and their levels in the matched CRC tissues. The serum expression levels of mir-21 and -23a were more predictive of CRC than mir-27a. Conclusion: Circulating mir-21, -23a, and -27a expression levels appear to be valuable diagnostic biomarkers for CRC, especially when combined.

Astragalus membranaceus and Punica granatum alleviate infertility and kidney dysfunction induced by aging in male rats.

By aging, male fertility and kidney function decline. Therefore, the investigation of health span-extending agents becomes more urgent to overcome aging-induced infertility and kidney dysfunction. The current research was undertaken to investigate the antiaging efficacy of Astragalus membranaceus telomerase activator-65 (Ta-65) and pomegranate supplements. Forty male Wistar rats were divided into young rats, aged rats, aged rats treated with Ta-65 (500mg/kg/day), and aged rats treated with pomegranate (250mg/kg/day). Testosterone, FSH, LH, and kidney functions were measured in serum. Sperm analysis as well as testicular histological examination was performed. Aging caused an imbalance in male sex hormones resulting in sperm abnormality and reductions in the sperm count and motility. Elevations in serum creatinine, uric acid, sodium, and potassium were reported in aged rats. Treatment with Ta-65 or pomegranate effectively ameliorated all the deteriorations induced by normal aging in male fertility and renal function. Ta-65 and pomegranate possessed strong antiaging activity by alleviating aging-induced male infertility through reestablishing the hormonal balance and testis architecture. They also alleviated the kidney dysfunction. On comparing Ta-65 with pomegranate, the improvement in FSH, LH, and sperm abnormalities caused by Ta-65 was much better than that caused by pomegranate.

Viscoelastic Haemostatic Assays in Cardiovascular Critical Care.

The initiation and management of anticoagulation is a fundamental practice for a wide variety of indications in cardiovascular critical care, including the management of patients with acute MI, stroke prevention in patients with AF or mechanical valves, as well as the prevention of device thrombosis and thromboembolic events with the use of mechanical circulatory support and ventricular assist devices. The frequent use of antiplatelet and anticoagulation therapy, in addition to the presence of concomitant conditions that may lead to a propensity to bleed, such as renal and liver dysfunction, present unique challenges. The use of viscoelastic haemostatic assays provides an additional tool allowing clinicians to strike a delicate balance of attaining adequate anticoagulation while minimising the risk of bleeding complications. In this review, the authors discuss the role that viscoelastic haemostatic assay plays in cardiac populations (including cardiac surgery, heart transplantation, extracorporeal membrane oxygenation, acute coronary syndrome and left ventricular assist devices), and identify areas in need of further study.

Improving the catalytic efficiency of thermostable Geobacillus stearothermophilus xylanase XT6 by single-amino acid substitution.

Directed evolution using error-prone polymerase chain reaction was employed in the current study to enhance the catalytic efficiency of a thermostable Geobacillus stearothermophilus xylanase XT6 parent. High-throughput screening identified two variants with enhanced activity. Sequencing analysis revealed the presence of a single-amino acid substitution (P209L or V161L) in each variant. The maximum activity of mutant V161L and P209L was at 85°C and 70°C, respectively. Both mutants exhibited maximum activity at pH 7. The thermal and alkaline tolerance of mutant V161L only were markedly improved. The two mutants were more resistant to ethanol inhibition than the parent. Substrate specificity of the two mutants was shifted from beechwood xylan to birchwood xylan. The potential of the two mutants to hydrolyze rice straw and sugarcane bagasse increased. Both turnover number (kcat) and catalytic efficiency (kcat/kM) increased 12.2- and 5.7-folds for variant P209L and 13- and 6.5-folds for variant V161L, respectively, towards birchwood xylan. Based on the previously published crystal structure of extracellular G. stearothermophilus xylanase XT6, V161L and P209L mutation locate on ßα-loops. Conformational changes of the respective loops could potentiate the loop swinging, product release and consequently result in enhancement of the catalytic performance.

Cobalt(II) Diphenylazodioxide Complexes Induce Apoptosis in SK-HEP-1 Cells.

The cobalt(II) complex salts [Co(bpy)(az)2](PF6)2 and [Co(az)4](PF6), each bearing the unusual cis-N,N'-diphenylazodioxide ligand, were both screened as possible anticancer agents against SK-HEP-1 liver cancer cells. Both compounds were found to induce substantial apoptosis as an increasing function of concentration and time. Measurement of apoptosis-related proteins indicated that both the extrinsic and intrinsic pathways of apoptosis were activated. The apoptotic activity induced by these salts is not displayed either by simple cobalt(II) salts or complexes or by the free nitrosobenzene ligand. Additionally, these compounds did not induce apoptosis, as assessed by poly(adenosine diphosphate-ribose) polymerase cleavage, in several other cell lines.